occur. some possible complications of a d & c may include, but are not limited to, the following : patients who are allergic to or sensitive to medications, iodine, or latex should notify their doctor. if you are pregnant or suspect that you may be pregnant, you should notify your health care provider. there may be other risks depending on your specific medical condition. be sure to discuss any concerns with your doctor prior to the procedure. a vaginal, cervical, or pelvic infection may interfere with a d & c. before the procedure your doctor will explain the procedure to you and offer you the opportunity to ask any questions that you might have about the procedure. you will be asked to sign a consent form that gives your permission to do the procedure. read the form carefully and ask questions if something is not clear. in addition to a complete medical history, your doctor may perform a complete physical examination to ensure you are in good health before undergoing the procedure. you may undergo blood tests or other diagnostic tests. if your procedure requires general, spinal, or epidural anesthesia, you will be asked to fast for eight hours before the procedure, generally after midnight. if your procedure is to be done under local anesthesia, your doctor will give you instructions about fasting. if you are pregnant or suspect that you are pregnant, you should notify your health care provider. he or she may recommend a pregnancy test prior to the procedure. notify your doctor if you are sensitive to or are allergic to any medications, iodine, latex, tape, and anesthetic agents ( local and general ). notify your doctor of all medications ( prescribed and over - the - counter ) and herbal supplements that you are taking. notify your doctor if you have a history of bleeding disorders or if you are taking any anticoagulant ( blood - thinning ) medications, aspirin, or other medications that affect blood clotting. it may be necessary for you to stop these medications prior to the procedure. if a sedative is given before the procedure, you will need someone to drive you home afterwards. you may want to bring a sanitary napkin to wear home after the procedure. based on your medical condition, your doctor may request other specific preparation. during the procedure click image to enlarge a d & c may be performed in a doctor ’ s office, on an outpatient basis, or as part of your stay in a hospital. procedures may vary depending on your condition and your doctor


. during the procedure click image to enlarge a d & c may be performed in a doctor ’ s office, on an outpatient basis, or as part of your stay in a hospital. procedures may vary depending on your condition and your doctor ’ s practices. the type of anesthesia will depend on the specific procedure being performed. some d & c procedures may be performed while you are asleep under general anesthesia, or while you are awake under spinal or epidural anesthesia. if spinal or epidural anesthesia is used, you will have no feeling from your waist down. the anesthesiologist will continuously monitor your heart rate, blood pressure, breathing, and blood oxygen level during the surgery. generally, a d & c follows this process : you will be asked to remove clothing and be given a gown to wear. you will be instructed to empty your bladder. you will be positioned on an operating or examination table, with your feet and legs supported as for a pelvic examination. an intravenous ( iv ) line may be started in your arm or hand. a urinary catheter may be inserted. your doctor will insert an instrument called a speculum into your vagina to spread the walls of the vagina apart to expose the cervix. your cervix may be cleansed with an antiseptic solution. for local anesthesia, the doctor may numb the area using a small needle to inject medication. if general or regional anesthesia is used, the anesthesiologist will continuously monitor your heart rate, blood pressure, breathing, and blood oxygen level during surgery. a type of forceps, called a tenaculum, may be used to hold the cervix steady for the procedure. the inside of the cervical canal may be scraped with a small curette if the cervical tissue needs to be examined. a thin, rod - like instrument, called a uterine sound, may be inserted through the cervical opening to determine the length of the uterus. if you have local anesthesia, this may cause some cramping. the sound will then be removed. the cervix will be dilated by inserting a series of thin rods. each rod will be larger in diameter than the previous one. this process will gradually enlarge the opening of the cervix so that the curette ( spoon - shaped instrument ) can be inserted. the curette will be inserted through the cervical opening into the uterus and the


the previous one. this process will gradually enlarge the opening of the cervix so that the curette ( spoon - shaped instrument ) can be inserted. the curette will be inserted through the cervical opening into the uterus and the sharp spoon - shaped edges will be passed across the lining of the uterus to scrape away the tissues. in some cases, suction may be used to remove tissues. if you have local anesthesia, this may cause cramping. the instruments will be removed. any tissues collected with the procedure will be sent to the lab for examination. pregnancy tissues ( called products of conception ) may be sent to the lab for culture or testing for genetic or chromosomal abnormalities. after the procedure the recovery process will vary depending on the type of procedure performed and type of anesthesia that was administered. if you received regional or general anesthesia, you will be taken to the recovery room for observation. once your blood pressure, pulse, and breathing are stable and you are alert, you will be taken to your hospital room or discharged to your home. if this procedure was performed on an outpatient basis, you should plan to have another person drive you home. after a d & c using local anesthesia, you may rest for about two hours before going home. you may want to wear a sanitary pad for bleeding. it is normal to have some spotting or light vaginal bleeding for a few days after the procedure. you may experience cramping for the first few days after a d & c. you may be instructed not to douche, use tampons, or have intercourse for two to three days after a d & c, or for a period of time recommended by your doctor. you may also have other restrictions on your activity, including no strenuous activity or heavy lifting. because a d & c removes the lining of the uterus, the lining must build back up. your next menstrual period may begin earlier or later than usual. you may resume your normal diet unless your doctor advises you differently. take a pain reliever for cramping or soreness as recommended by your doctor. aspirin or certain other pain medications may increase the chance of bleeding. be sure to take only recommended medications. your doctor will advise you on when to return for further treatment or care. notify your doctor if you have any of the following : your doctor may give you additional or alternate instructions after the procedure, depending on your particular situation. the content provided here is for informational


the belief in astrology was almost universal in the middle of the seventeenth century ; it began to waver and become doubtful towards the close of that period, and in the beginning of the eighteenth the art fell into general disrepute, and even under general ridicule. yet it still retained many partisans, even in the seats of learning. grave and studious men were loth to relinquish the calculations which had early become the principal objects of their studies, and felt reluctant to descend from the predominating height to which a supposed insight into futurity, by the power of consulting abstract influences and conjunctions, had exalted them over the rest of manking. among those who cherished this imaginary privilege with undoubting faith, was an old clergyman, with whom mannering was placed during his youth. he wasted his eyes in observing the stars, and his brains in calculations upon their various combinations. his pupil, in early youth, naturally caught some portion of his enthusiasm, and laboured for a time to make himself master of the technical process of astrological research ; so that, before he became convinced of its absurdity, william lilly himself would have allowed him a curious fancy and piercing judgement in resolving a question of nativity. on the present occasion, he arose as early in the morning as the shortness of the day permitted, and proceeded to calculate the nativity of the young heir of ellangowan. he undertook the task secundum artem, as well to keep up appearances, as from a sort of curiosity to know whether he yet remembered, and could practice, the imaginary science. he accordingly erected his scheme, or figure of heaven, divided into its twelve houses, placed the planets therein according to the ephemeris, and rectified their position to the hour and moment of the nativity. without troubling our readers with the general prognostications which judicial astrology would have inferred from these circumstances, in this diagram there was one significator which pressed remarkably upon our astrologers attention. mars having dignity in the cusp of the twelfth house, threatened captivity, or sudden and violent death, to the native ; and mannering having recourse to those further rules by which diviners pretend to ascertain the vehemency of this evil direction, observed from the result, that three periods would be particularly hazardoushis fifthhis tenthhis twenty - first year. it was somewhat remarkable, that mannering had once before tried a similar piece


to ascertain the vehemency of this evil direction, observed from the result, that three periods would be particularly hazardoushis fifthhis tenthhis twenty - first year. it was somewhat remarkable, that mannering had once before tried a similar piece of foolery, at the instance of sophia wellwood, the young lady to whom he was attached, and that a similar conjunction of planetary influence threatened her with death, or imprisonment, in her thirty - ninth year. she was at this time eighteen ; so that, according to the result of the scheme in both cases, the same year threatened her with the same misfortune that was presaged to the native or infant, whom that night had introduced into the world. struck with this coincidence, mannering repeated his calculations ; and the result approximated the events predicted, until at length the same month and day of the month, seemed assigned as the period of peril to both. it will be readily believed, that in mentioning this circumstance we lay no weight whatever upon the pretended information thus conveyed. but it often happens, such is our natural love for the marvellous, that we willingly contribute our own efforts to beguile our better judgements. whether the coincidence which i have mentioned was really one of those singular chances, which sometimes happen against all ordinary calculations ; or whether mannering, bewildered amid the arithmetical labyrinth and technical jargon of astrology, had insensibly twice followed the same clue to guide him out of the maze ; or whether his imagination, seduced by some point of apparent resemblance, lent its aid to make the similitude between the two operations more exactly accurate than it might otherwise have been, it is impossible to guess ; but the impression upon his mind that the results exactly corresponded was vividly and indelibly strong. he could not help feeling surprise at a coincidence so singular and unexpected. does the devil mingle in the dance, to avenge himself for our trifling with an art said to be of magical origin? or is it possible, as bacon and sir thomas browne admit, that there is some truth in a sober and regulated astrology, and that the influence of the stars is not to be denied, though the due application of it, by the knaves who pretend to practise the art, is greatly to be suspected? a moments consideration of the subject induced him to dismiss this opinion as fantastical, and only sanctioned by those learned men, either because they durst not at once shock the universal prejudices of their age,


the art, is greatly to be suspected? a moments consideration of the subject induced him to dismiss this opinion as fantastical, and only sanctioned by those learned men, either because they durst not at once shock the universal prejudices of their age, or because they themselves were not altogether freed from the contagious influence of a prevailing superstition. yet the result of his calculations in these two instances left so unpleasing an impression on his mind, that, like prospero, he mentally relinquished his art, and resolved, neither in jest nor earnest, ever again to practise judicial astrology. he hesitated a good deal what he should say to the laird of ellangowan concerning the horoscope of his first - born ; and at length resolved plainly to tell him the judgement which he had formed, at the same time acquainting him with the futility of the rules of art on which he had proceeded. with this resolution he walked out upon the terrace. if the view of the scene around ellangowan had been pleasing by moonlight, it lost none of its beauty by the light of the morning sun. the land, even in the month of november, smiled under its influence. a steep but regular ascent led from the terrace to the neighbouring eminence, and conducted mannering to the front of the old castle. it consisted of two massive round towers, projecting, deeply and darkly, at the extreme angles of a curtain, or flat wall, which united them, and thus protecting the main entrance that opened through a lofty arch in the centre of the curtain into the inner court of the castle. the arms of the family, carved in freestone, frowned over the gateway, and the portal showed the spaces arranged by the architect for lowering the portcullis, and raising the drawbridge. a rude farmgate, made of young fir - trees nailed together, now formed the only safeguard of this once formidable entrance. the esplanade in front of the castle commanded a noble prospect. the dreary scene of desolation, through which mannerings road had lain on the preceding evening, was excluded from the view by some rising ground, and the landscape showed a pleasing alternation of hill and dale, intersected by a river, which was in some places visible, and hidden in others where it rolled betwixt deep and wooded banks. the spire of a church, and the appearance of some houses, indicated the situation of a village at the place where the stream had its


, which was in some places visible, and hidden in others where it rolled betwixt deep and wooded banks. the spire of a church, and the appearance of some houses, indicated the situation of a village at the place where the stream had its junction with the ocean. the vales seemed well cultivated, the little enclosures into which they were divided skirting the bottom of the hills, and sometimes carrying their lines of straggling hedge - rows a little way up the ascent. above these were green pastures, tenanted chiefly by herds of black cattle, then the staple commodity of the country, whose distant low gave no unpleasing animation to the landscape. the remoter hills were of a sterner character, and at still greater distance swelled into mountains of dark heath, bordering the horizon with a screen, which gave a defined and limited boundary to the cultivated country, and added at the same time the pleasing idea that it was sequestered and solitary. the sea - coast, which mannering now saw in its extent, corresponded in variety and beauty with the inland view. in some places it rose into tall rocks, frequently crowned with the ruins of old buildings, towers, or beacons, which, according to tradition, were placed within sight of each other, that in times of invasion or civil war they might communicate by signal for mutual defence and protection. ellangowan castle was by far the most extensive and important of these ruins, and asserted, from size and situation, the superiority which its founders were said once to have possessed among the chiefs and nobles of the district. in other places, the shore was of a more gentle description, indented with small bays, where the land sloped smoothly down, or sent into the sea promontories covered with wood. a scene so different from what last nights journey had presaged, produced a proportional effect upon mannering. beneath his eye lay the modern housean awkward mansion, indeed, in point of architecture, but well situated, and with a warm pleasant exposure. how happily, thought our hero, would life glide on in such a retirement! on the one hand, the striking remnants of ancient grandeur, with the secret consciousness of family pride which they inspire ; on the other, enough of modern elegance and comfort to satisfy every moderate wish. here then, and with thee, sophia! on entering the gateway, he found that the rude magnificence of the inner court amply corresponded with the grandeur of the exterior. on the one side ran a range of


every moderate wish. here then, and with thee, sophia! on entering the gateway, he found that the rude magnificence of the inner court amply corresponded with the grandeur of the exterior. on the one side ran a range of windows, lofty and large, divided by carved mullions of stone, which had once lighted the great hall of the castle ; on the other were various buildings of different heights and dates, yet so united as to present to the eye a certain general effect of uniformity of front. the doors and windows were ornamented with projections, exhibiting rude specimens of sculpture and tracery, partly entire and partly broken down, partly covered by ivy and trailing plants, which grew luxuriantly among the ruins. that end of the court which faced the entrance had also been formerly closed by a range of buildings ; but owing, it was said, to its having been battered by the ships of the parliament under deane, during the long civil war, this part of the castle was much more ruinous than the rest, and exhibited a great chasm, through which mannering could observe the sea, and the little vessel ( an armed lugger ) which retained her station in the centre of the bay. 1 while mannering was gazing round the ruins, he heard from the interior of an apartment on the left hand the voice of the gipsy he had seen on the preceding evening. he soon found an aperture through which he could observe her without being himself visible ; and could not help feeling that her figure, her employment, and her situation, conveyed the exact impression of an ancient sibyl. she sat upon a broken corner - stone in the angle of a paved apartment, part of which she had swept clean to afford a smooth space for the evolutions of her spindle. a strong sunbeam, through a lofty and narrow window, fell upon her wild dress and features, and afforded her light for her occupation ; the rest of the apartment was very gloomy. equipped in a habit which mingled the national dress of the scottish common people with something of an eastern costume, she spun a thread, drawn from wool of three different coloursblack, white, and greyby assistance of those ancient implements of housewifery, now almost banished from the land, the distaff and spindle. as she spun, she sang what seemed to be a charm. mannering, after in vain attempting to make himself master of the exact words of her song, afterwards attempted the following paraphrase of


land, the distaff and spindle. as she spun, she sang what seemed to be a charm. mannering, after in vain attempting to make himself master of the exact words of her song, afterwards attempted the following paraphrase of what, from a few intelligible phrases, he concluded to be its purport : ere our translator, or rather our free imitator, had arranged these stanzas in his head, and while he was yet hammering out a rhyme for dwindle, the task of the sibyl was accomplished, or her wool was expended. she took the spindle, now charged with her labours, and undoing the thread, gradually measured it, by casting it over her elbow, and bringing each loop round between her forefinger and thumb. when she had measured it out, she muttered to herself, a hank, but not a haill anethe full years othree score and ten, but thrice broken, and thrice to oop ( i. e. to unite ) ; hell be a lucky lad an he win through wit. he was apparently a seafaring man, rather under the middle size, and with a countenance bronzed by a thousand conflicts with the north - east wind. his frame was prodigiously muscular, strong, and thickset ; so that it seemed as if a man of much greater height would have been an inadequate match in any close personal conflict. he was hard - favoured, and, which was worse, his face bore nothing of the insouciance, the careless frolicsome jollity and vacant curiosity of a sailor on shore. these qualities, perhaps, as much as any others, contribute to the high popularity of our seamen, and the general good inclination which our society expresses towards them. their gallantry, courage, and hardihood, are qualities which excite reverence, and perhaps rather humble pacific landsmen in their presence ; and neither respect nor a sense of humiliation, are feelings easily combined with a familiar fondness towards those who inspire them. but the boyish frolics, the exulting high spirits, the unreflecting mirth of a sailor, when enjoying himself on shore, temper the more formidable points of his character. there was nothing like these in this mans face ; on the contrary, a surly and even savage scowl appeared to darken features which would have been harsh and unpleasant under any expression or modification. where are you, mother de


points of his character. there was nothing like these in this mans face ; on the contrary, a surly and even savage scowl appeared to darken features which would have been harsh and unpleasant under any expression or modification. where are you, mother deyvilson? he said, with somewhat of a foreign accent, though speaking perfectly good english. donner and blitzen! we have been staying this half hour. come, bless the good ship and the voyage, and be cursed to ye for a hag of satan! at this moment he noticed mannering, who, from the position which he had taken to watch meg merriliess incantations, had the appearance of some one who was concealing himself, being half hidden by the buttress behind which he stood. the captain, for such he styled himself, made a sudden and startled pause, and thrust his right hand into his bosom, between his jacket and waistcoat, as if to draw some weapon. what cheer, brother? you seem on the outlookeh? ere mannering, somewhat struck by the mans gesture and insolent tone of voice, had made any answer, the gipsy emerged from her vault and joined the stranger. he questioned her in an undertone, looking at manneringa shark alongsideeh? tousand donnerno ; im all in the way of fair tradejust loaded yonder from douglas, in the isle of manneat cogniacreal hyson and souchongmechlin lace, if you want anyright cogniacwe bumped ashore a hundred kegs last night. there was a mixture of impudence, hardihood, and suspicious fear about this man, which was inexpressibly disgusting. his manners were those of a ruffian, conscious of the suspicion attending his character, yet aiming to bear it down by the affectation of a careless and hardy familiarity. mannering briefly rejected his proffered civilities ; and after a surly good morning, hatteraick retired with the gipsy to that part of the ruins from which he had first made his appearance. a very narrow staircase here went down to the beach, intended probably for the convenience of the garrison during a siege. by this stair, the couple, equally amiable in appearance and respectable by profession, descended to the sea - side. the soi - disant captain embarked in a small boat with two men, who appeared to wait for him, and the gipsy remained on the shore, reciting or singing,


moon landings | looking back to nasa ' s apollo lunar missions channel | bbc four first broadcast | 27 february 2006 duration | 118 minutes 4 seconds july 1969 saw one of mankind ' s greatest technological achievements - the first landing on the moon. in this special compilation of archive footage, originally broadcast as part of bbc4 ' s ' moon night ', patrick moore presents the story of man ' s first steps onto another world. as patrick moore notes at the beginning of this programme, much of the live commentary and discussion from the bbc ' s presentation of the moon landings has been lost. producer paul vanezis pieced together this compilation using all of the surviving footage, including segments from the sound archives, bridged with suitable material from nasa ' s own recordings. patrick moore was then able to cover any missing segments with his own narration, which was specially recorded for this broadcast. man goes into space - next stop : the moon! an astronomer states the case for putting telescopes on the moon. is there life on the moon? reg turnill explores nasa ' s quarantine facilities. what will the apollo astronauts actually be doing on the moon? was the race to get man on the moon a waste of money? a british scientist awaits samples of moon dust. remembering the moon landings and exploring the solar system. an interview with former nasa chief dr thomas paine. reg turnill reports on apollo 15 ' s discovery of the ' genesis rock '. a christmas conversation about the moon. how 13 women were blocked from joining nasa ' s space program. michael portillo revisits the race to the moon. looking back to 20 july 1969. which will be the next nation to reach the moon? why should any nation need to go to the moon again? celebrating the 50th anniversary of ' the sky at night ' with eugene cernan. the artist astronaut of apollo 12. the apollo 16 astronaut finds his way on the moon. the scientist astronaut of apollo 17. this page is best viewed in an up - to - date web browser with style sheets ( css ) enabled. while you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. please consider upgrading your browser software or enabling style sheets ( css ) if you are able to do so.


despite autonomy from german policies, petain brought in legislation setting up a jewish statute in october 1940. by then about 150, 000 jews had crossed what was known as the demarcation line to seek protection from vichy in the south - only to find they were subjected to fierce discrimination along lines practised by the germans in the north. jews were eventually banned from the professions, show business, teaching, the civil service and journalism. after an intense propaganda campaign, jewish businesses were ' aryanised ' by vichy ' s commission for jewish affairs and their property was confiscated. more than 40, 000 refugee jews were held in concentration camps under french control, and 3, 000 died of poor treatment during the winters of 1940 and 1941. the writer arthur koestler, who was held at le vernet near the spanish frontier, said conditions were worse than in the notorious german camp, dachau. during 1941 anti - semitic legislation, applicable in both zones, was tightened. french police carried out the first mass arrests in paris in may 1941when 3, 747 men were interned. two more sweeps took place before the first deportation train provided by french state railways left for germany under french guard on 12 march 1942. on 16 july 1942, french police arrested 12, 884 jews, including 4, 501 children and 5, 802 women, in paris during what became known as la grande rafle ( ' the big round - up ' ). most were temporarily interned in a sports stadium, in conditions witnessed by a paris lawyer, georges wellers. ' all those wretched people lived five horrifying days in the enormous interior filled with deafening noise... among the screams and cries of people who had gone mad, or the injured who tried to kill themselves ', he recalled. within days, detainees were being sent to germany in cattle - wagons, and some became the first jews to die in the gas chambers at auschwitz. french courts, responding to mitterrand ' s warnings that trials would cause civil unrest, blocked other prosecutions, including that of the vichy police chief, rene bousquet, who organised the paris and vichy zone mass arrests. he was assassinated by a lone gunman in june 1993. it was not until mitterrand retired in 1995 that france began to face up to its responsibility in the persecution of jews. when the new right - wing president, jacques chirac, came to power, he immediately condemned vichy as a criminal regime and two years later the catholic church publicly asked for forgiveness for its failure to protect the jews. but


in the persecution of jews. when the new right - wing president, jacques chirac, came to power, he immediately condemned vichy as a criminal regime and two years later the catholic church publicly asked for forgiveness for its failure to protect the jews. but the most significant step forward was the trial in 1997 of maurice papon, 89, for crimes concerning the deportation of jews from bordeaux. he had served as a cabinet minister after the war, before losing a 16 - year legal battle to avoid trial. he was released from jail because of poor health, but his ten - year prison sentence has been interpreted as official recognition of french complicity in the holocaust, although there are still those who continue to defend his actions. since the trial, france has opened up hidden archives and offered compensation to survivors - and ensured that schools, where history manuals used not to mention france ' s part in the deportations, now have compulsory lessons on vichy persecution. while anti - semitism is still a social problem in france, there is no official discrimination, and today ' s 600, 000 - strong jewish community is represented at every level of the establishment, including in the catholic church, where the archbishop of paris is cardinal jean - marie lustiger. in 1942, while on the run from the french police, lustiger converted to catholicism, but three years later was told that his mother had died in the auschwitz gas chambers. it seems fitting that he presently ( june 2003 ) occupies such an important position within french society. find out more a history of the jews by paul johnson ( weidenfeld and nicholson, 1987 ) vichy france and the jews by michael marrus, robert paxton ( schocken, 1983 ) vichy - auschwitz by serge klarsfeld ( fayard, 1983 ) the collapse of the third republic by william shirer ( pan, 1969 ) france : the dark years by julian jackson ( oxford university press, 2001 ) occupation by ian ousby ( pimlico, 1997 ) the extreme right in france : 1789 to present by peter davies ( routledge, 2002 ) verdict on vichy by michael curtis ( weidenfield and nicholson, 2002 ) places to visit a complete repertory of anti - jewish legislation and its consequences was drawn up by a government commission headed by jean matteoli in 2000. a printed version of the findings can be obtained from la documentation francaise, 29 - 31 quai voltaire, 75344 paris cedex 07. telephone : 00331 - 40157000 a cd - rom for libraries and researchers with a facsimile


with support from : a piece of green sky at aeomart toulouse 2012 the aerospace industry is taking a commitment to reducing its impact on the environment and consumption of fossil energy. with skyrocketing air traffic green technologies are becoming a necessity for the industry. the following companies will show off their innovations in 2012 : at the green village, airbus will highlight its participation in the european clean sky research programme, which aims to develop technologies for cleaner and quieter aircraft in order to secure an innovative and competitive air transport system for the decades to come. airbus will provide information on its two main research & technology activities within the smart fixed wing aircraft ( sfwa ) integrated technology demonstrator ( itd ) projects : - the design and test flight of an all - new natural laminar flow full scale wing - the integration and flight demonstration of the contra rotating open rotor ( cror ) propulsion system. atr is the " green reference " in regional aviation. atr aircraft fuel consumption, and as a consequence, its co2 emissions, are 50 % lower than compared to a regional jet. over a one - year period, a fleet of 10 atrs save more than 50, 000 tons of co2 compared to an equivalent fleet of regional jets. atr is also the first regional aircraft manufacturer to have obtained the iso14001 environmental certification throughout the life cycle of its products. workshop : december 5, wednesday 11 : 55am - 12 : 25pm care : clean aerospace for regions presented by francois aumonier, care project manager, aerospace valley green technologies are key competitive advantages of future air transport systems. major environmental challenges are at stake in aircraft life cycle management, air traffic management and integration of air transport into multimodal transport system. the care project will reinforce the r & d networking already instigated at regional level through research - driven clusters and will increase the competitiveness of these regions in the field of green aircraft transportation by : corac is the council for civil aeronautics research ( conseil pour la recherche aeronautique civile ). it was created in july 2008 following commitments made in late 2007 during the grenelle environment forum. established according to the acare ( * ) model, it brings together, under the impetus of dgac and gifas, all of the french players in the air transport sector, meaning the aviation industry, airlines, airports, onera, and relevant institutions and ministries. the implementation of corac represents a desire to ensure the consistency of research and innovation efforts in the aviation sector


all of the french players in the air transport sector, meaning the aviation industry, airlines, airports, onera, and relevant institutions and ministries. the implementation of corac represents a desire to ensure the consistency of research and innovation efforts in the aviation sector, especially in terms of preservation of the environment and sustainable development. among its first achievements, it created the technological road map for aeronautics research, serving as the foundation for the implementation of an ambitious and coordinated research strategy focusing on objectives for management of the environmental footprint of air transport by 2020 : world wide leader in painting system lines, assembly, measure and industrial cleaning process, we are revolutionizing cleaning with our new vapor saturated and combined solution : ecocsteam. developed and patented in our french competence center durr ecoclean, our ecocsteam machine is the achievement of a great collaboration between germany and france. our solution cleans without chemical products and ensures a high quality degreasing ; it is the most profitable, economic and ecological cleaning solution. ecocsteam enables to clean parts of any dimension and various materials such as : composites, plastics, carbon parts, slewing rings or even aluminum parts. we ensure technical training and an after sales services everywhere in the world. faustson was founded 30 years ago in colorado by paul svaldi, whose father ' s name is faust, hence its name. it is unique in its expansion from a one - machine, single - handed, after hours activity to what it has become today : a preferred supplier to ball aerospace and lockheed martin - among others - excelling in high - precision manufacturing. our recent expansion into europe is a logical progression, and laying stress on growing green was a natural choice. we ' ve adapted our work ethic to become initiators in our region of the us. we as a company recycle all metal chips and solid parts when many others discard them. all oils and fluids are disposed of with a minimum environmental impact. we also have changed our weekly timetable to four 10 - hour days, which saves a full day ' s worth of gas for all of us, as well as one less day of energy consumption at the shop. we are an environmental engineering and sustainable development consulting company. our positioning regarding aircraft and space businesses relates to the environmental performance of products, processes and industrial sites. our main services are : regulatory assessment / compliance and environmental management system setting up ( site & product, iso 14000 / emas ), risk analysis and management, environmental analysis covering the whole product life cycle


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part 1 - introduction sean m. o ’ brien, p. e., leed ap michael b. waite, leed ap as energy resources are diminished, energy costs increase, and the detrimental environmental effects of combustion emissions become more pronounced and better understood, optimizing building energy performance becomes essential to building owners, the global community and the planet itself. the building design and construction industry is becoming more aware of the effect of the building enclosure on energy use, particularly with the increasing prominence of “ green ” building rating systems, such as leed, higher stringency in energy efficiency standards, such as ashrae 90. 1, and stricter enforcement of building energy codes. however, with only a few exceptions, rating systems, standards and codes in the united states all but ignore air barriers. and, despite numerous studies and extensive analysis showing the benefits of air barriers, and many architects and engineers espousing the advantages of reducing air leakage, the industry has been slow to adopt air leakage control as a priority, producing buildings with admirable intentions, but marginal performance. enclosure air leakage can increase heating and cooling energy use of buildings. many buildings are designed to maintain a slight positive air pressure ( relative to the exterior environment ), so the greater the air leakage through the enclosure, the greater the volume of ventilation air necessary to maintain the required pressure differential. typically, this air needs to be either heated or cooled to reach the system ’ s supply air temperatures. in some cases, the air may need to be dehumidified even when hvac zones demand heating, which requires the ventilation air to be cooled ( and dehumidified ) before it is heated. air infiltration due to negative building air pressure in southern climates, or during the summer throughout most of the u. s., carries both heat and moisture into buildings. this can result in moisture - related problems, but also increases the burden on the building ’ s cooling systems. air conditioning systems will be required to provide more sensible and latent heat removal than would otherwise be needed with lower levels of air leakage. consequently, the balance between latent and sensible cooling may be different than that predicted for design conditions, especially since exterior air will often contain significantly more moisture than interior air. this may result in mechanical systems being unable to maintain the required interior temperature or relative humidity levels without operating more frequently. the effects described above are significant, but the most substantial impact of air leakage on building energy use is generally an increase in building heating requirements in cold


in mechanical systems being unable to maintain the required interior temperature or relative humidity levels without operating more frequently. the effects described above are significant, but the most substantial impact of air leakage on building energy use is generally an increase in building heating requirements in cold climates. verifying this effect is simple : stand by a leaky window on a cold windy day or feel the air rush in behind you when opening the door of a tall building during the winter. the negative implications of air leakage are not limited solely to cold northern climates. a 1995 study performed by nist ( national institute of standards and technology ) found that 15 % of the heating load in commercial buildings nationwide is caused by air leakage. the conclusions of this study are particularly noteworthy because the authors found that, perhaps counter intuitively, this percentage is higher for newer buildings than for older buildings. this does not necessarily mean that air leakage is higher in newer buildings, but it likely indicates that other enclosure characteristics ( e. g. insulation levels and passive solar heating design concepts ) are improving. 3. moisture problems moisture - related problems due to enclosure air leakage can be caused by humid interior air coming into contact with cold surfaces while exiting the building, or by humid exterior air finding a detrimental path into the building. as with many issues with air leakage, the problems typically occur at the details, such as transition areas between envelope components and assemblies, rather than in the field of the wall. when buildings or portions of buildings are under negative pressure, the air flow is inward. as discussed above, exterior air can contain a significant amount of moisture. when this air is pulled into the building through wall cavities, ceiling plenums or similar spaces, moisture in the air can condense if it passes over cool surfaces, which are common in air - conditioned spaces. water can accumulate on materials that are known to be conducive to mold growth, such as paper - faced gypsum wallboard. when building or portions of buildings are at positive pressure relative to the exterior air, the air flow is outward. in most buildings, this may not be a problem as interior humidity levels are not high enough in the winter to cause significant problems. however, in high humidity buildings, such as museums and natatoriums ( pool structures ), the interior air contains ample moisture to cause condensation if it reaches cold surfaces. the most visible cases of condensation in these buildings are where thermal bridging – high conductivity materials bypassing low conductivity materials – occurs


structures ), the interior air contains ample moisture to cause condensation if it reaches cold surfaces. the most visible cases of condensation in these buildings are where thermal bridging – high conductivity materials bypassing low conductivity materials – occurs, such as at window frames and structural members. in positively pressurized buildings with air leakage paths to the exterior, humid air often “ finds ” hidden cold surfaces within the enclosure. the air flow paths are typically within concealed spaces, allowing moisture to accumulate over time undetected, and potentially causing catastrophic failures. over the past few decades, the building industry has developed some understanding of the causes of moisture - related problems. however, much focus has been placed on vapor retarders without adequate attention to the effects of air leakage. vapor retarders are intended to prevent the migration of moisture through building materials by diffusion. in many cases, drawings call for vapor retarders where a continuous air barrier system is necessary. humid air can carry up to 100 times more moisture than can be transferred by diffusion through typical porous building materials. the discrepancy between the widespread application of vapor retarders and the generally poor design of air barriers is likely due to the prevalence of vapor retarder requirements and the near - complete lack of air barrier requirements in u. s. building codes. 4. codes and standards state building codes typically reference or adopt ashrae standard 90. 1 – energy standard for buildings except low - rise residential buildings, or the international energy conservation code ( iecc ), which references ashrae 90. 1 itself. the most widely used and referenced energy codes and standards have well - developed requirements for wall and roof insulation, and for glazing assembly thermal transmittance and solar heat gain. they contain requirements for maximum allowable conductive thermal transmission through the envelope. every few years these values are evaluated and, often, slightly increased. these requirements may be approaching – many would argue they have reached – a point of diminishing returns for which very little additional performance is gained by adding insulation or by reducing solar heat gain through glazing. neither the iecc nor ashrae 90. 1 contains quantitative requirements for air barriers. while there are requirements that seams and transition areas be sealed, these provisions are difficult to enforce and contain no performance requirements for the sealing materials. the lack of air barrier requirements in energy standards is a significant oversight, as reducing air leakage can have a greater impact on building energy use than the incremental increases in insulation or reductions in


enforce and contain no performance requirements for the sealing materials. the lack of air barrier requirements in energy standards is a significant oversight, as reducing air leakage can have a greater impact on building energy use than the incremental increases in insulation or reductions in glazing shgc typically included in new editions of codes and standards. voluntary guidelines are also falling short of their stated goals. leed, a widely accepted guideline for sustainable building design, references ashrae 90. 1 for its energy efficiency prerequisite and credits, but contains no separate provisions specific to air barriers. while some benefit can be obtained through the leed energy performance credit, the performance rating method – outlined in ashrae 90. 1 and used by leed to compare a proposed building design to a “ baseline ” building – requires that a building not be given credit for reducing air leakage ( i. e., designers can specify an air leakage rate, but that rate must be the same for both the baseline and the “ improved ” buildings ). this process used to exhibit anticipated improved energy performance prescribes that the air infiltration input in the energy model be the same for the proposed design and the baseline building. some states have begun adopting air barrier requirements, yet even the most stringent among them do not meet the code provisions implemented in some other countries ( e. g. canada and the uk ), or the recommendations of enclosure design professionals and energy efficiency experts. the u. s. army corps of engineers recently began requiring air barriers ( and quantifiable enclosure air leakage performance ) for all new and renovated buildings, and federal building design guidelines now contain air barrier provisions. however, the lack of a national standard air barrier requirement prevents the concept from taking hold on the scale we have seen with insulation, thermally - broken windows and vapor retarders. the importance of air barriers in building design is clear and well - documented. this is particularly true now that enough of the the “ low - hanging fruit ” in energy efficient enclosure design – insulation and improved glazing performance, for example – has been picked, bringing us near the point of diminishing returns on those improvements. sustainable building design considerations – an essential aspect of all building design – can no longer be compartmentalized. as with other building features, air barriers need to be designed and constructed as a system, and integrated with all other building systems. the next article in this series will discuss methods and materials that can be used to produce acceptable enclosure air leakage performance. part 2 -


building features, air barriers need to be designed and constructed as a system, and integrated with all other building systems. the next article in this series will discuss methods and materials that can be used to produce acceptable enclosure air leakage performance. part 2 - design guidelines for air barrier systems sean m. o ’ brien, p. e., leed ap michael b. waite, leed ap 1. air barrier basics the basic function of an air barrier system is to prevent uncontrolled air leakage through the building enclosure. to this end, an air barrier must be a complete system of materials and components that work together to provide a continuous barrier to airflow. even small discontinuities in an air barrier can significantly reduce its performance, since air will follow the path of least resistance regardless of its location. air barriers must resist air pressure caused by wind, stack effect, or mechanical pressurization of a building, so they must also be relatively rigid or have solid backing capable of resisting moderate to high pressures. unfortunately, the system concept is often ignored and designers “ specify an air barrier ” by including a specification section for self - adhered or spray - applied membranes or spray - applied foam insulation – sometimes as an addendum or afterthought once the rest of the building has been designed. this article discusses performance criteria for air barrier systems and highlights common problems found in air barrier specifications. 2. air barrier or vapor retarder? a major stumbling block for many designers has been appreciating the difference between air barriers and vapor retarders. this is made more difficult by the fact that many air barriers are also vapor retarders, such as the ubiquitous “ peel - and - stick ” membranes that are used in some way, shape, or form on nearly all new construction projects. the danger in confusing these two systems is that the proper location for a vapor retarder is dependent on both the interior and exterior environments, while an air barrier can typically be located anywhere within the building enclosure as long as it is continuous. table 1, below, summarizes the differences between air barriers and vapor retarders. table 1 – summary of differences between air barriers and vapor retarders | vapor retarder | | air barrier | | purpose | | control of water vapor flow via diffusion through building materials. | | control of water vapor flow via air movement, primarily through gaps or cracks in the building enclosure. | | requirements for continuity | | does not need to be completely continuous ; can contain


| control of water vapor flow via diffusion through building materials. | | control of water vapor flow via air movement, primarily through gaps or cracks in the building enclosure. | | requirements for continuity | | does not need to be completely continuous ; can contain small gaps, holes, or unsealed laps without significant loss of performance. | | must be continuous to be effective ; even small discontinuities can significantly affect performance. | | location | | typically installed on " warm - in - winter " side of insulation ( some exceptions apply depending on climate ). improper location can exacerbate condensation problems. | | can be installed anywhere in the building envelope if vapor permeable, otherwise follow guidelines for vapor retarder. | | structural support | | no structural support. | | must be continuously supported and be capable of resisting forces from wind, mechanical pressurization, and stack effect. | | detailing | | minimal detailing required to achieve design intent. | | careful detailing of transitions and changes in material are necessary to support proper system installation and meet the design intent of an air barrier system. | another area of confusion is the concept of air barrier materials vs. air barrier assemblies and systems. the following definitions are presented to establish the difference between materials, assemblies, and systems : • an air barrier material is a primary element that provides a continuous barrier to the movement of air ( e. g., self adhered membranes ) • an air barrier assembly consists of the air barrier materials and accessories that provide a continuous designated plane of resistance to the movement of air through portions of building enclosure assemblies. air barrier assemblies typically consist of both air barrier materials and connections to adjacent materials, as well as penetrations, laps, seams, etc. • an air barrier system is the combination of air barrier assemblies installed to provide a continuous barrier to the movement of air through building enclosures. 3. performance criteria specifying appropriate ( and more importantly, achievable ) performance criteria for air barrier assemblies and systems is a surprisingly challenging task. established performance criteria exist for nearly all aspects of the building enclosure, such as windows and doors, curtain walls, and roof systems. this is the result of many years of work by designers, testing companies, and industry organizations. over the course of several decades, unrealistic or unverifiable performance criteria such as “ windows shall not leak under any conditions ” have gradually been replaced by criteria such as “ windows shall not experience water leakage at a test pressure of 5. 5 pounds per


several decades, unrealistic or unverifiable performance criteria such as “ windows shall not leak under any conditions ” have gradually been replaced by criteria such as “ windows shall not experience water leakage at a test pressure of 5. 5 pounds per square foot ( psf ) when tested according to astm standard e1105 ”. performance criteria for air barrier assemblies and systems are still developing ; the third article in this series summarizes the current testing and performance standards for air barriers. although performance criteria for air barrier materials are relatively well established, problems with air barrier systems rarely develop as a result of air leakage through the field of an air barrier sheet or membrane. further, air barrier products such as spray - applied or self - adhered membranes often have leakage rates that are orders of magnitude lower than the generally accepted criteria of 0. 004 cfm / sf at 0. 3 in. water for air barrier materials, making leakage through the field of the barrier unlikely to be a significant problem. since most air leakage occurs at details and transitions, the air permeance of the primary air barrier material ( s ) is often unrelated to the overall air leakage through a building. the air barrier association of america ( abaa ) recommends a maximum air leakage rate of 0. 04 cfm / sf at 0. 3 in. water for air barrier assemblies, which takes into account seams and penetrations and is more representative or real building conditions. the 2005 national building code of canada recommends ( but does not require ) a slightly more conservative value of 0. 02 cfm / sf at 0. 3 in. water for buildings that maintain interior relative humidity levels between 27 and 55 % - typical of most buildings with the exception of cold storage facilities and natatoriums. since even “ seamless ” systems such as fluid - applied membranes will still have transitions and penetrations, such as brick ties or other cladding attachments, applying the more stringent air barrier material criterion to air barrier assemblies is unrealistic. the effects of air leakage through windows, doors, and curtain walls ( i. e., fenestration ) are rarely considered when evaluating air barrier assemblies. this is a significant oversight, as most of the air leakage through a properly designed air barrier system will likely occur through these components. established values for air leakage through fenestration range from 0. 06 cfm / sf at 1. 2 in. of water for glazed curtain walls to 0. 4 cfm /


properly designed air barrier system will likely occur through these components. established values for air leakage through fenestration range from 0. 06 cfm / sf at 1. 2 in. of water for glazed curtain walls to 0. 4 cfm / sf at 1. 2 in. of water for operable windows. maximum air leakage rates are included in most building / energy codes as well as industry standards from organizations such as ashrae and aama. “ typical ” values for air leakage through fenestration are somewhat difficult to determine as the various ( local, state, and national ) codes and standards attempt to reach a consensus. although the test procedures for air barrier assemblies ( astm e2357 ) include the air barrier connections at windows, the window opening itself is “ blanked off ” during the test so that only the perimeter is evaluated. consider the example of a 10 ft x 10 ft air barrier assembly containing a 4 ft x 4 ft double hung window. specifying a maximum assembly leakage rate of 0. 04 cfm / sf would result in an allowable airflow of 4 cfm through the assembly. for a typical code - compliant window meeting the performance criteria of 0. 4 cfm / sf, the window leakage alone would be 6. 4 cfm, exceeding the allowable value for the entire assembly without even considering leakage through other air barrier components. if a window is specified in assembly testing, a modified value for assembly leakage that considers the inherently “ leakier ” windows must be used. to account for the wide range of materials, details, and transitions in the air barrier of any particular building, it is often more useful to speak in terms of system ( i. e., whole - building ) air leakage than material, assembly, or component leakage. this is especially true for purposes of energy simulation or hvac load calculation, where the global quantity of air leakage is the primary concern. unfortunately, there are very few established standards for whole - building air leakage that designers can reference. the 2009 ashrae handbook of fundamentals, chapter 16 notes three “ levels ” of air leakage for typical buildings. these are 0. 1 cfm / sf at 0. 3 in. water for “ tight ” buildings, 0. 3 cfm / sf for “ average ” buildings, and 0. 6 cfm / sf for “ leaky ” buildings. these general classes of air leakage were first presented in the results of a study of 8 commercial buildings in canada,


. 3 cfm / sf for “ average ” buildings, and 0. 6 cfm / sf for “ leaky ” buildings. these general classes of air leakage were first presented in the results of a study of 8 commercial buildings in canada, ranging in height from 11 to 22 stories, and clad with glazed aluminum curtain walls. despite being based on a small sample size and very specific building types, these “ classes ” are frequently cited in discussions of typical building airtightness or building performance criteria. a more recent study of approximately 200 low rise commercial and institutional buildings in the united states found an overall average leakage rate of 1. 55 cfm / sf at 0. 3 in. water – over 5 times greater than the “ average ” value of 0. 3 cfm / sf noted above. unfortunately, neither study clarifies if the buildings were designed with continuous air barriers. considering this limitation, the average value of 1. 55 cfm / sf from the 2005 study could be seen as a maximum value for building air leakage, as a new building with a dedicated, continuous air barrier is likely to provide greatly improved performance. for buildings designed and constructed with continuous air barriers, abaa currently recommends an overall building air leakage rate of 0. 4 cfm / sf at 0. 3 in. of water. more stringently, the u. s. army corps of engineers specifies a maximum leakage rate of 0. 25 cfm / sf at 0. 3 in. of water for some of their projects, and is considering the use of that criteria as a standard for all new buildings ( although no formal design guide has been developed to include airtightness criteria at the time of this writing ). in 2002, the united kingdom added a requirement for whole building / system air leakage to their “ building regulations for england & wales ” for commercial buildings greater than 10, 760 sf ( currently 5, 380 sf in the 2006 code ). the established value, which is required to be verified through whole - building testing, is 0. 547 cfm / sf at 0. 2 in. of water. preliminary findings have shown a marked improvement in airtightnes of more “ standardized ” building types such as warehouses and retail stores, with many buildings exceeding the code - required value. this is a significant improvement in airtightness, as typical values for air permeability of the same building types prior to the 2002 code change were on the order of two to three times higher than values achieved in recent years. however,


value. this is a significant improvement in airtightness, as typical values for air permeability of the same building types prior to the 2002 code change were on the order of two to three times higher than values achieved in recent years. however, less standardized building types, such as offices, schools, and hospitals, have exhibited a much lower “ passing ” rate. this is most likely attributed to the general lack of attention to air barrier detailing at conditions for which typical practices are not well established, in contrast to less unique building types for which a large body of detailing experience exists. given the results of recent studies in the united states, the average commercial building significantly exceeds this target. until additional studies of more recently constructed buildings ( designed with continuous air barriers ) are available, system air leakage criteria may be difficult to enforce due the lack of knowledge about what level of air leakage is typical and achievable for new buildings. in addition, the acceptability of leakage criteria is likely to fluctuate as new data becomes available and more testing is performed. 4. specifications of air barrier systems at present, there is a significant disconnect between the criteria contained in most specifications for air barrier system and the actual performance achieved in the field. this is due to a combination of factors, including designers ’ unfamiliarity with air barrier systems, poor understanding of how air barriers function, and misunderstanding regarding test procedures and limitations. the air barrier association of america has proposed a new specification section to establish the administrative and procedural requirements necessary for the construction of a complete air barrier system in a new building. since the air barrier system consists of multiple materials covered under several specification sections ( including windows, doors, curtain walls, roofing systems, and exterior wall air barriers ), this specification seeks to establish some kind of connection between the various sections and provide a means of coordinating the different trades involved in the construction of the air barrier system. as the popularity of air barriers has grown in the past few years, so too have the number of projects where air barriers were added to the scope during design ( or even early construction ) by the inclusion of a single specification section for a sheet or spray - applied membrane. this approach creates an air barrier in name only, and does not address the numerous connections of that material / assembly to other components in the building. details such as window perimeters and roof - to - wall joints are critical to the performance of the overall air barrier system, and require much more coordination and planning than is likely to happen during the construction process,


assembly to other components in the building. details such as window perimeters and roof - to - wall joints are critical to the performance of the overall air barrier system, and require much more coordination and planning than is likely to happen during the construction process, when trades may be running behind schedule and design / consulting budgets may have been exhausted. the following common mistakes should be avoided when specifying air barrier systems : • failure to coordinate air barrier components, such as specifying windows that are difficult to integrate successfully with the air barrier, or specifying air barrier materials or assemlblies with conflicting performance. since the air barrier is only as strong as the weakest component, specifying high performance windows in a building with a poor ( or no ) air barrier will do little for overall airtightness. the same is true of specifying an air barrier in a wall but not in the adjacent roof, while requiring the entire building to pass an airtightness test. quantitative testing of air barrier systems installed as part of a building addition where the “ base ” building has no such systems is also generally of little value, unless the addition is separated by airtight interior partitions to make it a truly separate volume. • failure to provide sufficient details for the air barrier system, especially at critical locations such as window perimeters and roof - to - wall interfaces. many specifications provide only general information or do not show sufficient detail on the drawings, but may include language intended to place the detailing design burden on the contractor. air barrier systems are complex and require careful design to be effective. just as we would not allow the contractor to design the structural system for the building “ on the fly ”, it is unreasonable to expect contractors to assume the role of primary designer of the air barrier details. • specification of impossible or unrealistic test criteria. some specifications require that air barrier assemblies be tested in the field to verify performance, but do not take into account the numerous issues associated with qualitative testing that may make testing impractical or unlikely to yield useful results. some specifications contain incompatible test criteria, such as including a window in the air barrier assembly that is tested but not adjusting the assembly criteria to account for the inclusion of that window. given the differences between criteria for windows and criteria for air barrier assemblies, it may be impossible to meet the “ typical ” assembly leakage of 0. 04 cfm / sf due to leakage at the window. • specification of system performance criteria that are not backed up by research or practical experience. given the lack of whole


may be impossible to meet the “ typical ” assembly leakage of 0. 04 cfm / sf due to leakage at the window. • specification of system performance criteria that are not backed up by research or practical experience. given the lack of whole - building airtightness data on relatively recent buildings that include air barrier systems, specifying a system leakage rate can lead to confusion or disagreement if the building fails to achieve the test criteria. without realistic established values for system leakage ( with the exception of the 2006 united kingdom building regulations, which is still in its infancy ), it may be difficult to enforce compliance with a seemingly arbitrary requirement. next article in the air barrier systems series : field testing of air barrier systems part 3 - field testing of air barrier systems sean m. o ’ brien, p. e., leed ap michael b. waite, leed ap 1. why test? for some enclosure systems such as thermal insulation, in - place performance is generally consistent with calculated performance. however, physical testing is often the only way to accurately assess the installed performance of air barrier systems. the sensitivity of air barriers to workmanship ( e. g., sealing laps, making transitions, etc. ) and their potentially large impact on building energy use, make in - place performance testing an important quality control measure for air leakage assessment of specific details, and verification on a whole building ( or “ system ” ) level. 2. test methods 2. 1 quantitative testing in this arrangement, the measured airflow is a combination of flow through the specimen and the test chamber. to separate these flows, the test ( using an interior chamber ) is initially performed with the exterior of the specimen sealed off, typically with an impermeable sheet material. after this initial test, a second set of measurements is taken with the specimen unsealed. the difference in measurement between these two tests is the leakage through the specimen. chambers are typically constructed on the interior of the specimen for practical reasons ( e. g., access ), although they can technically be located on either side. for typical punched windows, air leakage, on the order of several cubic feet per minute cfm ), can be measured reliably with equipment designed for use in the field. air barrier assemblies, consisting of several components, can be tested in a similar manner, but the testing is generally more difficult for several reasons. first, air barrier assemblies are typically much larger than discrete components such as windows and doors. second, air barrier assemblies may contain


, consisting of several components, can be tested in a similar manner, but the testing is generally more difficult for several reasons. first, air barrier assemblies are typically much larger than discrete components such as windows and doors. second, air barrier assemblies may contain unique geometries that make construction of an air - tight test chamber difficult, such as parapets, structural members or slab edges that interrupt the test chamber ( or in the case of steel studs, create so many penetrations in the chamber that it must be constructed from the exterior ). if performed during construction, scaffolding or other temporary constructions may interfere with access to the assembly. third, testing of complete assemblies may not be practical due to the installation of different materials at different times, as in the case of a wall air barrier being installed long before the roof air barrier. figure 2 illustrates the same assembly being tested using an exterior chamber, which resolves some, but not all, of these issues. although the use of an exterior chamber and seal eliminates leakage through the surrounding walls, it raises a new problem – how to remove the seal following the initial test. due to the need for accurate measurement of relatively small airflows, even a small amount of uncertainty in the testing could result in “ false negative ” results. removing some or all of the chamber will disturb perimeter conditions and invalidate the initial chamber leakage measurement. chambers with operable doors or removable panels are required to allow for removal of the initial seal. these chambers must be tested multiple times, following operation of the door / panel, to demonstrate that operation does not modify the basic chamber leakage rate. only after this is demonstrated can the initial seal be removed and a reliable measurement of specimen leakage be made. 2. 2 qualitative testing since a primary goal of air barriers is the reduction in air infiltration and corresponding reduction in heating cooling loads, a useful value to designers is typically the system air leakage rate. knowing the leakage rates through individual components can be useful for verifying component performance ( typically windows and curtain walls ) or comparing the relative performance of existing vs. replacement components in retrofit applications, but for new construction these rates are less critical to determining overall building performance than the whole - building value. at the component or assembly level, knowing where air leakage occurs is often far more useful than knowing how much leakage is actually occurring, especially in the case of high humidity buildings, such as museums and swimming pools, where even small air leaks can cause significant condensation


level, knowing where air leakage occurs is often far more useful than knowing how much leakage is actually occurring, especially in the case of high humidity buildings, such as museums and swimming pools, where even small air leaks can cause significant condensation. qualitative testing has the advantage of providing installers with the locations of defects in the air barrier that require repairs. providing an air barrier installer with an air leakage rate through the overall system provides little practical information ( e. g., locations of major air leaks ) on how the system can be improved. the test chambers and setups used for quantitative testing can be used for qualitative testing as well. however, chambers for qualitative testing are often easier to construct since then need only provide a level of airtightness sufficient to achieve the desired test pressure ; this is in contrast to chambers for quantitative testing, which must be relatively airtight to allow for accurate measurement of the airflows in question. a basic test chamber can be constructed on the interior of the component ( photo 4 ), connected to a fan and differential pressure gage only. the chamber is typically necessary in new construction projects, where the building enclosure is still relatively open to the elements. for enclosed, or partially enclosed, buildings, a blower door or similar device can be used to place whole rooms or whole buildings under positive or negative pressure, eliminating the need for a specially - constructed chamber. rather than measure the air leakage directly, visualization aids such as tracer smoke or infrared thermography ( if temperature conditions allow ) are used to locate leaks in the air barrier system tracer smoke is a relatively simple method of locating air leaks while a specimen or area has a pressure differential applied. the smoke will quickly reveal air leakage paths as it is drawn into gaps or blown away from them ( photo 5 ). an alternate method is to use a large smoke generator within the test chamber so that smoke is “ blown out ” through any breaches in the system. a variety of test methods are available for both quantitative and qualitative evaluation of air barrier systems. a summary of the most common methods is provided in table 1. understanding the special requirements for these procedures, as well as the difficulties and limitations associated with the tests, are critical for performing successful tests that produce accurate and meaningful results. table 1 – common tests for air barriers astm e2178 - standard test method for air permeance of building materials | quantitative – laboratory test | | air barrier materials ( membranes, etc.


successful tests that produce accurate and meaningful results. table 1 – common tests for air barriers astm e2178 - standard test method for air permeance of building materials | quantitative – laboratory test | | air barrier materials ( membranes, etc. ) | | astm e2357 - standard test method for determining air leakage of air barrier assemblies. | | quantitative – laboratory test | | air barrier assemblies ( membrane, including laps and penetrations but not including fenestration components ) | | astm e283 - standard test method for determining rate of air leakage through exterior windows, curtain walls, and doors under specified pressure differences across the specimen | | quantitative – laboratory test | | fenestration components | | astm e783 - standard test method for field measurement of air leakage through installed exterior windows and doors | | quantitative - field test | fenestration components ; can be modified to test air barrier assemblies | | astm e1186 - standard practices for air leakage site detection in building envelopes and air barrier systems | | qualitative - field test | | all air barrier materials, assemblies, and components | astm e779 - standard test method for | quantitative - field test | | air barrier systems ( i. e., whole buildings ) | part 4 - energy analysis sean m. o ’ brien, p. e., leed ap michael b. waite, leed ap the first article of this series discussed the problems with excessive air leakage, detrimental air leakage paths through the enclosure, and pressurization for certain building types and environments. in subsequent articles we presented materials and design strategies to minimize air leakage, and discussed how to quantify enclosure air leakage in existing buildings, and the challenges this poses. this article addresses the difficult question of how to predict the amount of air leakage in a new design, and the implications of inaccurate quantification of air leakage in new and existing buildings. underestimating air leakage could result in undersized mechanical equipment, but this is not typically the case since mechanical engineers employ safety factors in the design of cooling and, especially, heating systems. with the evolving implementation of sustainable design practices and the understanding of the effects of peak building energy on the required capacity of on - site equipment and the nation ' s energy infrastructure ( i. e. the number of power plants ), more sophisticated tools have gained prominence in sizing mechanical equipment and predicting building energy use. by employing more advanced tools,


the required capacity of on - site equipment and the nation ' s energy infrastructure ( i. e. the number of power plants ), more sophisticated tools have gained prominence in sizing mechanical equipment and predicting building energy use. by employing more advanced tools, there is a potential for smaller safety factors and, thus, smaller equipment. however, smaller safety factors coupled with inaccurate assumptions about building performance may cause problems. complicating matters, building owners and designers often expect energy analyses developed during design to be absolute predictors of building energy use. this expectation is generally unrealistic due to the wide variation in actual versus assumed building operation. in addition, mischaracterizing air leakage rates will reduce the accuracy of energy models and may adversely affect design decisions that depend on whole building energy analysis results. a theme throughout this series has been the importance of designing and understanding an air barrier as a system. in much the same way, the building enclosure itself is a system made up of many component assemblies, such as fenestration, insulation, waterproofing and air barriers. and, as discussed previously, the overall building is a system with far too many interdependent performance characteristics to allow for compartmentalization of our design evaluations. whole building energy analysis the use of whole building energy analysis ( often referred to as " energy modeling " ) to evaluate design options is becoming increasingly widespread throughout the building design community, and particularly in high performance building design. energy modeling allows users to include many more aspects of building design and operation than traditional hvac sizing approaches. naturally, it is very dependent on the accuracy of those inputs. no matter how simple or complex the tool, its performance relies on the user ' s understanding of the capabilities and limitations of that tool. the complexity and interdependence of building systems require that engineers constructing energy models understand how the systems interact and how the inputs and assumptions for individual systems relate to other systems and affect the predicted building performance as a whole. some practitioners in the building industry may expect energy models to be absolute predictors of building energy use. however, software developers ( and most users ) make no such claims. still, the presence of engineers ( or " modelers " who are not engineers or architects ) who claim the ability to predict actual energy use has provided fodder for energy modeling ' s detractors. though this article does not aim to examine - and certainly not adjudicate - the current deliberations in the industry over the proper role of whole building energy analysis, we


use has provided fodder for energy modeling ' s detractors. though this article does not aim to examine - and certainly not adjudicate - the current deliberations in the industry over the proper role of whole building energy analysis, we think it is important to understand these tools have their shortcomings, but also their advantages. to evaluate design options, system control schemes and building operation considerations, whole building energy analysis is beneficial in its primary role as a comparative tool. the assumed level of air leakage affects both the predicted energy performance of a building and what systems may appear attractive to a designer. that is, the relative performance of some energy efficiency measures is affected by the assumed air infiltration. the first item here is understood, and perhaps even intuitive, to the majority of designers. mischaracterizing the air leakage performance of the enclosure in an energy model will likely affect the building energy use predicted by that model. the effect will be particularly pronounced in heating - dominated climates, where the effect of air leakage is more significant. probably less intuitive is the fact that incorrect air leakage assumptions, even if they are consistent across all analyses, can affect the predicted improvement or increase in energy use for the design option ( or combination of criteria ) being evaluated. at higher leakage rates, the heating and cooling requirements are higher. since the absolute increase or reduction in energy use is similar under most conditions, the relative effect of air leakage will be less at higher leakage rates ( the denominator in the equation increases while the numerator remains the same ). generally, however, the opposite problem seems to present itself in many energy models we have seen : the predicted air leakage rate is much lower than that of the actual building. this can result in overstated energy savings, which can affect the economic analyses for a project. in most climates, the effect of inaccurate air leakage modeling on the evaluation of design options will not be significant enough to significantly influence the decision - making process. existing buildings, as is often the case in energy modeling, present unique challenges. on existing building projects, we are often trying to evaluate and predict the reduction in energy use associated with " tightening " the building enclosure. in these cases, improvements in thermal ( or solar heat gain ) performance are often coupled to reductions in air leakage in the same energy efficiency strategy ( e. g. replacing windows ). the best approach is to evaluate the envelope modifications with a range of air leakage rates to gauge the sensitivity of the building


) performance are often coupled to reductions in air leakage in the same energy efficiency strategy ( e. g. replacing windows ). the best approach is to evaluate the envelope modifications with a range of air leakage rates to gauge the sensitivity of the building ' s predicted performance to the assumed air leakage. we have found that utilizing the testing techniques discussed in the previous article to be effective in evaluating an existing building and envelope improvements. whole building tests establish a baseline and component tests can be used to quantify the contribution of specific envelope areas to the overall leakage rate. by assuming a leakage rate for these components after upgrading the envelope, the whole building rate can be adjusted in the energy model. air barriers in high performance building design standards the first article in this series touched upon the rise in popularity of " green building " rating systems, such as leed, and the increasing stringency of energy efficiency codes and standards, such as ashrae 90. 1. we discussed the lack of air barrier requirements in most codes and standards and the absence of any credit in leed rating systems for reducing air leakage. these systems - and the codes and standards themselves - rely heavily on whole building energy analysis to show compliance or to exhibit improved energy performance. due to the issues discussed above, the energy savings associated with various energy efficiency measures may be misrepresented if air leakage is modeled inaccurately. that said, the effect this has on certification under leed, while worthy of discussion, is a secondary concern. a good, continuous air barrier is essential to acceptable enclosure performance in high performance buildings. however, the supporting infrastructure for projects attempting to achieve a sustainable design has not been formalized. the benefits of air leakage must be properly included in these standards and programs, and the high performance building design process must account for air leakage in whole building energy analyses. we have now developed an understanding of the importance of good air barrier design ; outlined important design considerations, materials and methods ; discussed approaches to quantifying and tracking enclosure air leakage in existing buildings ; and presented the implications of inaccurate quantification or expectation of air leakage rates. we have touched upon the interaction between the enclosure and other building systems. we now must understand how a good air barrier changes overall building performance and how other systems need to be designed, constructed and controlled. the next article in this series will discuss the requirements for mechanical systems in tight buildings. we will focus primarily on how " business - as - usual " is often not an option and that code requirements may


systems need to be designed, constructed and controlled. the next article in this series will discuss the requirements for mechanical systems in tight buildings. we will focus primarily on how " business - as - usual " is often not an option and that code requirements may not be sufficient to provide an acceptable level of performance. about the authors sean o ’ brien is a senior project manager in the new york city office of simpson gumpertz & heger inc. mr. o ’ brien specializes in building science and building envelope performance, including computer simulation of heat, air, and moisture migration issues. he has investigated and designed repairs for a variety of buildings, from condominiums to natatoriums and art museums, and has published extensively on building science - related matters including moisture migration in masonry wall systems and condensation resistance of windows and curtain walls. he can be reached at email @ example. com michael waite is an engineer in the new york city office of simpson gumpertz & heger inc. he specializes in the interaction between mechanical systems and the building enclosure. he has designed and investigated a wide range of building types and has focused primarily on building energy performance, building enclosure design, and thermal and hygrothermal performance building enclosures. he is a member of ashrae sspc 90. 1 and its envelope subcommittee, as well as several other industry organizations. he can be reached at firstname. lastname @ example. org.


most of us have heard the expression, “ sleep tight ; don ’ t let the bed bugs bite. ” in recent years, this folksy turn of phrase has taken on a disturbingly literal meaning. reports of bed bug infestation rose more than 70 % since 2001. it ’ s unclear why they have made such a startling resurgence but there are ways to avoid becoming an ongoing victim of these what are they? bed bugs, or “ cimex lectularius ” in the nasty name of science, were put on this earth to terrify you. warm blood is the only substance they consume. scarier still, the tiny lil ’ vampires are extremely difficult to spot. bed bugs are nearly invisible to the naked eye. a fully - grown bug is a scant 4 millimeters long. to put that in perspective, the iphone 5 is 7. 6 millimeters thick. the pests even learn your sleeping habits and will attack regardless of the time of day. did i mention that females of the species can lay 500 eggs in their lifetime? that is horrifying! are you freaked out yet? well, buckle up because it gets even worse. bed bugs can survive for a full year without eating. like in a nightmare? yep! houses and apartments on the market can be actively infested even when unoccupied for months. another common breeding ground is hotels. bed bugs are like hitchhikers ; they sneak into a passing suitcase and catch a ride to the next destination. other hotspots include dormitories, schools, theaters, offices, hospitals, stores, trains, buses, taxis, and just about anywhere else people pass through in large numbers. is there any way to control this exsanguinous scourge? is all hope lost? prevention and detection of bed bugs bed bugs are blood - sucking monsters created by the devil himself but they will not kill you. the first step to protection is detection. if you think you might have an infestation, lift up your sheets and take a look. adult bugs are reddish - brown with flat bodies about the size of an apple seed. they will likely be hiding in any crevices available so grab a flashlight and start looking in the deepest, darkest recesses of your bed. small bloodstains on your sheets are also an indication of a bed bug problem. if you do find yourself with an infestation, don ’ t take it personally. bed bugs are not drawn to dirty homes any more than immaculate ones. however, it


##stains on your sheets are also an indication of a bed bug problem. if you do find yourself with an infestation, don ’ t take it personally. bed bugs are not drawn to dirty homes any more than immaculate ones. however, it is wise to reduce clutter around the house to minimize the number of hiding spots for the pests. when fighting bed bugs, make sure you have the right weapons. “ bug bombs ” or ” foggers ” have not proven to be effective because the bugs will simply hide from them. any products that claim to eradicate bed bugs should have an endorsement from the environmental protection agency or you may be combating vampire bugs with snake oil. a “ bed bug encasement ” for your mattress or box spring is a good investment since it protects against hiding pests but it still can ’ t protect against critters jumping from behind headboards and nightstands. to truly get rid of bed bugs is no easy feat. bed bugs are a common plight due to the hitchhiking of the bugs and the ignorance of the hosts. always search a new home / apartment for bed bugs. keep bags sealed in public places and steam clean the bag and the laundry upon arriving home. check reviews of bed bug hot spots online for any mention of trouble. finally, if your home is infested with tiny bloodsuckers, contact a professional to eradicate them. they are just bugs after all. invisible, death - proof, blood - sucking, monstrous bugs.


- car insurance - van insurance - bike insurance - home insurance - other products - about us - contact us a huge proportion of drivers are now relying on modern technology to help them get from a to b. and while, on the whole, sat - navs are one in a range of extremely useful tools available to motorists they can lead to frustration when they lead us astray. however, a recent study has found that too much reliance on sat - navs has lead to a possible decrease in driving skill for some motorists. the problem is due to one of concentration ; in a similar way that it has been found that talking on a mobile phone can reduce attention levels and lead to impaired driving. after taking repeated tests in a driving simulator participants were found to have driven less safely with a sat - nav in the car than without. the tests showed that although a few simple instructions were easy to cope with many drivers ’ ability faltered when too much information was available. driving errors included swerving on the road, speeding up and failure to notice pedestrians all of which would likely lead to a higher risk of accidents and even fatalities. on the positive side the researchers found that taking verbal instructions in the car was a really good way to get information to the driver and that it was much safer than trying to use a map whilst driving.


1. wrap each section of tube with a 4 - 1 / 2 - inch strip of colored paper. secure with glue stick. trace around the bottom of tube onto the foam to make circles for the wheels. cut out the wheels and glue the tops to the sides of the paper - covered tubes. the wheels will hang down below the tubes. glue two additional smaller wheels to each side of the train engine tube. glue wooden stars to the center of all the wheels. glue a craft stick across both sets of wheels on the engine. 2. make two folds in a 4x2 - inch rectangle of colored paper to make the engine cab. cut a window in the two outer sections and then glue either side to the top of the engine car. glue a spool funnel in front of the cab. decorate the other cars with colored paper rectan6gles and stripes. 3. cut the bottoms off the plastic cups. they will make the end caps to each train car. carefully punch a hole in the center of the bottoms. thread cord onto a darning needle and then string a cup bottom, paper tube, another cup bottom, and a spool. repeat the process until all cars are strung. if you push the cup bottoms onto the train cars, they ' ll fit tightly.


international. global oil consumption increased by 0. 7 % in 2011 to reach an all - time high of 88. 03 million barrels per day, according to new research conducted by the worldwatch institute for its vital signs online service. this rate of increase was considerably slower than in 2010, when oil consumption rose by 3. 3 % following a decline of 1. 3 % in 2009 due to the global financial crisis. china ' s oil consumption increased by 5. 5 % in 2011, and china accounted for about 85 % of global net growth in oil use. an increase in oil consumption of 5. 7 % in the former soviet union contributed another 37 % of net growth. but these increases were offset by declines in the united states and european union, where oil consumption fell by 1. 8 and 2. 8 percent respectively, writes worldwatch climate and energy research associate shakuntala makhijani. the gap in oil consumption between countries in the organisation for economic co - operation and development and all other countries narrowed further in 2011, with the two groups respectively accounting for 51. 5 % and 48. 5 % of total oil consumption. oil remained the largest source of primary energy worldwide in 2011, but its share fell for the twelfth consecutive year to 33 %. to meet continued growth in demand, global oil production rose for the second year in a row, by 1. 3 % in 2011, to reach 83. 58 million barrels per day. most of this increase was driven by higher production in countries that belong to the organization of petroleum exporting countries ( opec ), which overall grew by 3 percent in 2011. meanwhile oil production in non - opec countries fell slightly by 0. 1 %. oil production growth was slow compared with natural gas and coal production, which grew by 3. 1 % and 6. 1 %, respectively, in 2011. political unrest in the middle east and north africa had a significant effect on oil production in certain countries in the region. output in libya fell by 71 % in 2011 - - - - from 1. 7 million barrels per day ( 2 % of global production in 2010 ) to just 479, 000 barrels ( 0. 6 % of global output ) due to the disruptions related to the civil war. at the same time, tense political situations and violence in iran, syria, and yemen resulted in production declines of 0. 6, 13. 7, and 24 %, respectively, in 2011. the global impacts of the april 2010 deepwater horizon offshore drilling rig blowout and oil spill have