id stringlengths 24 24 | title stringclasses 442
values | context stringlengths 151 3.71k | question stringlengths 12 270 | answers dict |
|---|---|---|---|---|
56facb5d8f12f319006301b3 | High-definition_television | HDTV can be recorded to D-VHS (Digital-VHS or Data-VHS), W-VHS (analog only), to an HDTV-capable digital video recorder (for example DirecTV's high-definition Digital video recorder, Sky HD's set-top box, Dish Network's VIP 622 or VIP 722 high-definition Digital video recorder receivers, or TiVo's Series 3 or HD record... | What restriction does W-VHS recordings have? | {
"answer_start": [
64
],
"text": [
"analog only"
]
} |
56facb5d8f12f319006301b4 | High-definition_television | HDTV can be recorded to D-VHS (Digital-VHS or Data-VHS), W-VHS (analog only), to an HDTV-capable digital video recorder (for example DirecTV's high-definition Digital video recorder, Sky HD's set-top box, Dish Network's VIP 622 or VIP 722 high-definition Digital video recorder receivers, or TiVo's Series 3 or HD record... | What does D-VHS stand for? | {
"answer_start": [
31
],
"text": [
"Digital-VHS or Data-VHS"
]
} |
56facca98f12f319006301b9 | High-definition_television | The massive amount of data storage required to archive uncompressed streams meant that inexpensive uncompressed storage options were not available to the consumer. In 2008, the Hauppauge 1212 Personal Video Recorder was introduced. This device accepts HD content through component video inputs and stores the content in ... | When was the Hauppauge 1212 Personal Video Recorder introduced? | {
"answer_start": [
167
],
"text": [
"2008"
]
} |
56facca98f12f319006301ba | High-definition_television | The massive amount of data storage required to archive uncompressed streams meant that inexpensive uncompressed storage options were not available to the consumer. In 2008, the Hauppauge 1212 Personal Video Recorder was introduced. This device accepts HD content through component video inputs and stores the content in ... | How does the Personal Video Recorder store content? | {
"answer_start": [
317
],
"text": [
"in MPEG-2 format in a .ts file or in a Blu-ray compatible format .m2ts file"
]
} |
56facca98f12f319006301bb | High-definition_television | The massive amount of data storage required to archive uncompressed streams meant that inexpensive uncompressed storage options were not available to the consumer. In 2008, the Hauppauge 1212 Personal Video Recorder was introduced. This device accepts HD content through component video inputs and stores the content in ... | Recent systems can record a broadcast HD program in what format? | {
"answer_start": [
571
],
"text": [
"'as broadcast' format or transcode to a format more compatible with Blu-ray"
]
} |
56facca98f12f319006301bc | High-definition_television | The massive amount of data storage required to archive uncompressed streams meant that inexpensive uncompressed storage options were not available to the consumer. In 2008, the Hauppauge 1212 Personal Video Recorder was introduced. This device accepts HD content through component video inputs and stores the content in ... | What uncompressed storage option was introduced in 2008? | {
"answer_start": [
173
],
"text": [
"the Hauppauge 1212 Personal Video Recorder"
]
} |
56facd2f8f12f319006301c1 | High-definition_television | Analog tape recorders with bandwidth capable of recording analog HD signals, such as W-VHS recorders, are no longer produced for the consumer market and are both expensive and scarce in the secondary market. | W-VHS recorders are capable of recording what kinds of signals? | {
"answer_start": [
58
],
"text": [
"analog HD"
]
} |
56facd2f8f12f319006301c2 | High-definition_television | Analog tape recorders with bandwidth capable of recording analog HD signals, such as W-VHS recorders, are no longer produced for the consumer market and are both expensive and scarce in the secondary market. | What kind of recorder is no longer produced for the consumer market? | {
"answer_start": [
0
],
"text": [
"Analog tape"
]
} |
56facd2f8f12f319006301c3 | High-definition_television | Analog tape recorders with bandwidth capable of recording analog HD signals, such as W-VHS recorders, are no longer produced for the consumer market and are both expensive and scarce in the secondary market. | In the secondary market, analog tape recorders are considered what? | {
"answer_start": [
162
],
"text": [
"expensive and scarce"
]
} |
56faceb3f34c681400b0c135 | High-definition_television | In the United States, as part of the FCC's plug and play agreement, cable companies are required to provide customers who rent HD set-top boxes with a set-top box with "functional" FireWire (IEEE 1394) on request. None of the direct broadcast satellite providers have offered this feature on any of their supported boxes... | Prior to 2004, what were US cable companies required to provide customers who rent HD set-top boxes? | {
"answer_start": [
149
],
"text": [
"a set-top box with \"functional\" FireWire (IEEE 1394) on request"
]
} |
56faceb3f34c681400b0c136 | High-definition_television | In the United States, as part of the FCC's plug and play agreement, cable companies are required to provide customers who rent HD set-top boxes with a set-top box with "functional" FireWire (IEEE 1394) on request. None of the direct broadcast satellite providers have offered this feature on any of their supported boxes... | When were boxes with "functional" FireWire no longer included in the FCC mandate? | {
"answer_start": [
362
],
"text": [
"July 2004"
]
} |
56faceb3f34c681400b0c137 | High-definition_television | In the United States, as part of the FCC's plug and play agreement, cable companies are required to provide customers who rent HD set-top boxes with a set-top box with "functional" FireWire (IEEE 1394) on request. None of the direct broadcast satellite providers have offered this feature on any of their supported boxes... | Content is now protected by what encryption? | {
"answer_start": [
473
],
"text": [
"5C"
]
} |
56faceb3f34c681400b0c138 | High-definition_television | In the United States, as part of the FCC's plug and play agreement, cable companies are required to provide customers who rent HD set-top boxes with a set-top box with "functional" FireWire (IEEE 1394) on request. None of the direct broadcast satellite providers have offered this feature on any of their supported boxes... | What can 5c encryption prevent? | {
"answer_start": [
505
],
"text": [
"duplication of content or simply limit the number of copies permitted"
]
} |
56f9e2819b226e1400dd15e8 | Wood | It has been used for thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers (which are strong in tension) embedded in a matrix of lignin which resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, or... | In addition to being used to build things, what has wood been used for over thousands of years? | {
"answer_start": [
49
],
"text": [
"fuel"
]
} |
56f9e2819b226e1400dd15e9 | Wood | It has been used for thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers (which are strong in tension) embedded in a matrix of lignin which resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, or... | What kind of strong fibers are part of the composite of wood? | {
"answer_start": [
136
],
"text": [
"cellulose"
]
} |
56f9e2819b226e1400dd15ea | Wood | It has been used for thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers (which are strong in tension) embedded in a matrix of lignin which resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, or... | What's the matrix in wood made up of? | {
"answer_start": [
207
],
"text": [
"lignin"
]
} |
56f9e2819b226e1400dd15eb | Wood | It has been used for thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers (which are strong in tension) embedded in a matrix of lignin which resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, or... | What one word describes the function wood provides to a tree or plant? | {
"answer_start": [
482
],
"text": [
"support"
]
} |
56f9e2819b226e1400dd15ec | Wood | It has been used for thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers (which are strong in tension) embedded in a matrix of lignin which resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, or... | What does wood convey to leaves, roots, and other tissues of a woody plant in addition to water? | {
"answer_start": [
592
],
"text": [
"nutrients"
]
} |
56f9e5219e9bad19000a0b4b | Wood | The Earth contains about 434 billion cubic meters of growing stock forest, 47% of which is commercial. As an abundant, carbon-neutral renewable resource, woody materials have been of intense interest as a source of renewable energy. In 1991, approximately 3.5 cubic kilometers of wood were harvested. Dominant uses were ... | How many cubic meters of growing stock forest are there on the planet? | {
"answer_start": [
25
],
"text": [
"434 billion"
]
} |
56f9e5219e9bad19000a0b4c | Wood | The Earth contains about 434 billion cubic meters of growing stock forest, 47% of which is commercial. As an abundant, carbon-neutral renewable resource, woody materials have been of intense interest as a source of renewable energy. In 1991, approximately 3.5 cubic kilometers of wood were harvested. Dominant uses were ... | What percentage of the Earth's stock forest is commercial? | {
"answer_start": [
75
],
"text": [
"47%"
]
} |
56f9e5219e9bad19000a0b4d | Wood | The Earth contains about 434 billion cubic meters of growing stock forest, 47% of which is commercial. As an abundant, carbon-neutral renewable resource, woody materials have been of intense interest as a source of renewable energy. In 1991, approximately 3.5 cubic kilometers of wood were harvested. Dominant uses were ... | In addition to buildings, what is wood often used to make? | {
"answer_start": [
324
],
"text": [
"furniture"
]
} |
56f9e5219e9bad19000a0b4e | Wood | The Earth contains about 434 billion cubic meters of growing stock forest, 47% of which is commercial. As an abundant, carbon-neutral renewable resource, woody materials have been of intense interest as a source of renewable energy. In 1991, approximately 3.5 cubic kilometers of wood were harvested. Dominant uses were ... | About how many cubic kilometers of the vast stock forest's wood were harvested in 1991? | {
"answer_start": [
256
],
"text": [
"3.5"
]
} |
56f9e5219e9bad19000a0b4f | Wood | The Earth contains about 434 billion cubic meters of growing stock forest, 47% of which is commercial. As an abundant, carbon-neutral renewable resource, woody materials have been of intense interest as a source of renewable energy. In 1991, approximately 3.5 cubic kilometers of wood were harvested. Dominant uses were ... | In addition to being carbon neutral, what other adjective describes wood that makes it compelling as a renewable energy source? | {
"answer_start": [
109
],
"text": [
"abundant"
]
} |
56f9e7ba9e9bad19000a0b55 | Wood | A 2011 discovery in the Canadian province of New Brunswick uncovered the earliest known plants to have grown wood, approximately 395 to 400 million years ago. Wood can be dated by carbon dating and in some species by dendrochronology to make inferences about when a wooden object was created. | What year were the earliest plants that grew wood discovered? | {
"answer_start": [
2
],
"text": [
"2011"
]
} |
56f9e7ba9e9bad19000a0b56 | Wood | A 2011 discovery in the Canadian province of New Brunswick uncovered the earliest known plants to have grown wood, approximately 395 to 400 million years ago. Wood can be dated by carbon dating and in some species by dendrochronology to make inferences about when a wooden object was created. | In which Canadian province were the oldest woody plants found? | {
"answer_start": [
45
],
"text": [
"New Brunswick"
]
} |
56f9e7ba9e9bad19000a0b57 | Wood | A 2011 discovery in the Canadian province of New Brunswick uncovered the earliest known plants to have grown wood, approximately 395 to 400 million years ago. Wood can be dated by carbon dating and in some species by dendrochronology to make inferences about when a wooden object was created. | If dendrochronology can't be used, what method would scientists employ to date wood? | {
"answer_start": [
180
],
"text": [
"carbon dating"
]
} |
56f9e7ba9e9bad19000a0b58 | Wood | A 2011 discovery in the Canadian province of New Brunswick uncovered the earliest known plants to have grown wood, approximately 395 to 400 million years ago. Wood can be dated by carbon dating and in some species by dendrochronology to make inferences about when a wooden object was created. | How many millions of years old were the plants that were discovered in New Brunswick? | {
"answer_start": [
129
],
"text": [
"395 to 400"
]
} |
56f9e9738f12f3190062ffe7 | Wood | People have used wood for millennia for many purposes, primarily as a fuel or as a construction material for making houses, tools, weapons, furniture, packaging, artworks, and paper. The year-to-year variation in tree-ring widths and isotopic abundances gives clues to the prevailing climate at that time. | What has been the primary purpose of wood for millennia other than fuel? | {
"answer_start": [
83
],
"text": [
"construction material"
]
} |
56f9e9738f12f3190062ffe8 | Wood | People have used wood for millennia for many purposes, primarily as a fuel or as a construction material for making houses, tools, weapons, furniture, packaging, artworks, and paper. The year-to-year variation in tree-ring widths and isotopic abundances gives clues to the prevailing climate at that time. | What is often made of wood that provides shelter to people? | {
"answer_start": [
116
],
"text": [
"houses"
]
} |
56f9e9738f12f3190062ffe9 | Wood | People have used wood for millennia for many purposes, primarily as a fuel or as a construction material for making houses, tools, weapons, furniture, packaging, artworks, and paper. The year-to-year variation in tree-ring widths and isotopic abundances gives clues to the prevailing climate at that time. | For clues about the climate of a place, we can look at variation in isotopic abundances or what other thing? | {
"answer_start": [
213
],
"text": [
"tree-ring widths"
]
} |
56f9e9738f12f3190062ffea | Wood | People have used wood for millennia for many purposes, primarily as a fuel or as a construction material for making houses, tools, weapons, furniture, packaging, artworks, and paper. The year-to-year variation in tree-ring widths and isotopic abundances gives clues to the prevailing climate at that time. | What could be made out of wood that could be used to fight off attackers? | {
"answer_start": [
131
],
"text": [
"weapons"
]
} |
56f9e9738f12f3190062ffeb | Wood | People have used wood for millennia for many purposes, primarily as a fuel or as a construction material for making houses, tools, weapons, furniture, packaging, artworks, and paper. The year-to-year variation in tree-ring widths and isotopic abundances gives clues to the prevailing climate at that time. | What category of items often constructed from wood does a chair belong to? | {
"answer_start": [
140
],
"text": [
"furniture"
]
} |
56f9eb0bf34c681400b0bedb | Wood | Wood, in the strict sense, is yielded by trees, which increase in diameter by the formation, between the existing wood and the inner bark, of new woody layers which envelop the entire stem, living branches, and roots. This process is known as secondary growth; it is the result of cell division in the vascular cambium, ... | Where does wood come from? | {
"answer_start": [
41
],
"text": [
"trees"
]
} |
56f9eb0bf34c681400b0bedc | Wood | Wood, in the strict sense, is yielded by trees, which increase in diameter by the formation, between the existing wood and the inner bark, of new woody layers which envelop the entire stem, living branches, and roots. This process is known as secondary growth; it is the result of cell division in the vascular cambium, ... | What forms in a tree to increase its diameter? | {
"answer_start": [
146
],
"text": [
"woody layers"
]
} |
56f9eb0bf34c681400b0bedd | Wood | Wood, in the strict sense, is yielded by trees, which increase in diameter by the formation, between the existing wood and the inner bark, of new woody layers which envelop the entire stem, living branches, and roots. This process is known as secondary growth; it is the result of cell division in the vascular cambium, ... | What is the process of trees growing out to get bigger around called? | {
"answer_start": [
243
],
"text": [
"secondary growth"
]
} |
56f9eb0bf34c681400b0bede | Wood | Wood, in the strict sense, is yielded by trees, which increase in diameter by the formation, between the existing wood and the inner bark, of new woody layers which envelop the entire stem, living branches, and roots. This process is known as secondary growth; it is the result of cell division in the vascular cambium, ... | What do many places have four of that would cause growth rings in a tree? | {
"answer_start": [
405
],
"text": [
"seasons"
]
} |
56f9eb0bf34c681400b0bedf | Wood | Wood, in the strict sense, is yielded by trees, which increase in diameter by the formation, between the existing wood and the inner bark, of new woody layers which envelop the entire stem, living branches, and roots. This process is known as secondary growth; it is the result of cell division in the vascular cambium, ... | If a place has annual seasons, what are the growth rings on the trees there called? | {
"answer_start": [
668
],
"text": [
"annual rings"
]
} |
56f9ecbff34c681400b0bee5 | Wood | If there are differences within a growth ring, then the part of a growth ring nearest the center of the tree, and formed early in the growing season when growth is rapid, is usually composed of wider elements. It is usually lighter in color than that near the outer portion of the ring, and is known as earlywood or spri... | If a growth ring has differences over one season, would the part nearest the tree's center be narrower or wider? | {
"answer_start": [
194
],
"text": [
"wider"
]
} |
56f9ecbff34c681400b0bee6 | Wood | If there are differences within a growth ring, then the part of a growth ring nearest the center of the tree, and formed early in the growing season when growth is rapid, is usually composed of wider elements. It is usually lighter in color than that near the outer portion of the ring, and is known as earlywood or spri... | What name, besides springwood, is used for the part of a growth ring formed in the beginning of the growing season? | {
"answer_start": [
303
],
"text": [
"earlywood"
]
} |
56f9ecbff34c681400b0bee7 | Wood | If there are differences within a growth ring, then the part of a growth ring nearest the center of the tree, and formed early in the growing season when growth is rapid, is usually composed of wider elements. It is usually lighter in color than that near the outer portion of the ring, and is known as earlywood or spri... | If the opposite of springwood is summerwood, what's the opposite of earlywood? | {
"answer_start": [
394
],
"text": [
"latewood"
]
} |
56f9ecbff34c681400b0bee8 | Wood | If there are differences within a growth ring, then the part of a growth ring nearest the center of the tree, and formed early in the growing season when growth is rapid, is usually composed of wider elements. It is usually lighter in color than that near the outer portion of the ring, and is known as earlywood or spri... | Is earlywood usually lighter or darker than the part of the growth ring that forms later in the season? | {
"answer_start": [
224
],
"text": [
"lighter"
]
} |
56f9ecbff34c681400b0bee9 | Wood | If there are differences within a growth ring, then the part of a growth ring nearest the center of the tree, and formed early in the growing season when growth is rapid, is usually composed of wider elements. It is usually lighter in color than that near the outer portion of the ring, and is known as earlywood or spri... | Is summerwood the inner or outer portion of a growth ring? | {
"answer_start": [
332
],
"text": [
"outer"
]
} |
56f9ee81f34c681400b0bef7 | Wood | A knot is a particular type of imperfection in a piece of wood; it will affect the technical properties of the wood, usually reducing the local strength and increasing the tendency for splitting along the wood grain, but may be exploited for visual effect. In a longitudinally sawn plank, a knot will appear as a roughly... | What is the sort of circular imperfection in a piece of wood called? | {
"answer_start": [
2
],
"text": [
"knot"
]
} |
56f9ee81f34c681400b0bef8 | Wood | A knot is a particular type of imperfection in a piece of wood; it will affect the technical properties of the wood, usually reducing the local strength and increasing the tendency for splitting along the wood grain, but may be exploited for visual effect. In a longitudinally sawn plank, a knot will appear as a roughly... | What property of wood does a knot usually reduce in the wood around it? | {
"answer_start": [
144
],
"text": [
"strength"
]
} |
56f9ee81f34c681400b0bef9 | Wood | A knot is a particular type of imperfection in a piece of wood; it will affect the technical properties of the wood, usually reducing the local strength and increasing the tendency for splitting along the wood grain, but may be exploited for visual effect. In a longitudinally sawn plank, a knot will appear as a roughly... | In what direction is wood often sawn so that a knot appears as a solid circle that the grain flows around? | {
"answer_start": [
262
],
"text": [
"longitudinally"
]
} |
56f9ee81f34c681400b0befa | Wood | A knot is a particular type of imperfection in a piece of wood; it will affect the technical properties of the wood, usually reducing the local strength and increasing the tendency for splitting along the wood grain, but may be exploited for visual effect. In a longitudinally sawn plank, a knot will appear as a roughly... | Are knots usually lighter or darker than the surrounding wood? | {
"answer_start": [
347
],
"text": [
"darker"
]
} |
56f9ee81f34c681400b0befb | Wood | A knot is a particular type of imperfection in a piece of wood; it will affect the technical properties of the wood, usually reducing the local strength and increasing the tendency for splitting along the wood grain, but may be exploited for visual effect. In a longitudinally sawn plank, a knot will appear as a roughly... | The direction of grain in a knot can differ by as much as how many degrees from the regular wood? | {
"answer_start": [
513
],
"text": [
"90"
]
} |
56f9efa98f12f31900630003 | Wood | In the tree a knot is either the base of a side branch or a dormant bud. A knot (when the base of a side branch) is conical in shape (hence the roughly circular cross-section) with the inner tip at the point in stem diameter at which the plant's vascular cambium was located when the branch formed as a bud. | Other than the base of a side branch, what tree feature causes a knot? | {
"answer_start": [
58
],
"text": [
"a dormant bud"
]
} |
56f9efa98f12f31900630004 | Wood | In the tree a knot is either the base of a side branch or a dormant bud. A knot (when the base of a side branch) is conical in shape (hence the roughly circular cross-section) with the inner tip at the point in stem diameter at which the plant's vascular cambium was located when the branch formed as a bud. | What shape is the knot formed by a side branch's base? | {
"answer_start": [
116
],
"text": [
"conical"
]
} |
56f9efa98f12f31900630005 | Wood | In the tree a knot is either the base of a side branch or a dormant bud. A knot (when the base of a side branch) is conical in shape (hence the roughly circular cross-section) with the inner tip at the point in stem diameter at which the plant's vascular cambium was located when the branch formed as a bud. | What measurement of a stem determines a knot's inner tip placement? | {
"answer_start": [
216
],
"text": [
"diameter"
]
} |
56f9efa98f12f31900630006 | Wood | In the tree a knot is either the base of a side branch or a dormant bud. A knot (when the base of a side branch) is conical in shape (hence the roughly circular cross-section) with the inner tip at the point in stem diameter at which the plant's vascular cambium was located when the branch formed as a bud. | Because a knot's shape is conical, what shape does a cross-section of it have? | {
"answer_start": [
152
],
"text": [
"circular"
]
} |
56f9f187f34c681400b0bf01 | Wood | During the development of a tree, the lower limbs often die, but may remain attached for a time, sometimes years. Subsequent layers of growth of the attaching stem are no longer intimately joined with the dead limb, but are grown around it. Hence, dead branches produce knots which are not attached, and likely to drop o... | What will the lower limbs of a tree usually do during development? | {
"answer_start": [
56
],
"text": [
"die"
]
} |
56f9f187f34c681400b0bf02 | Wood | During the development of a tree, the lower limbs often die, but may remain attached for a time, sometimes years. Subsequent layers of growth of the attaching stem are no longer intimately joined with the dead limb, but are grown around it. Hence, dead branches produce knots which are not attached, and likely to drop o... | For what length of time can a dead lower limb stay attached to a tree? | {
"answer_start": [
107
],
"text": [
"years"
]
} |
56f9f187f34c681400b0bf03 | Wood | During the development of a tree, the lower limbs often die, but may remain attached for a time, sometimes years. Subsequent layers of growth of the attaching stem are no longer intimately joined with the dead limb, but are grown around it. Hence, dead branches produce knots which are not attached, and likely to drop o... | Rather than being joined to the limb that died, where do subsequent layers grow? | {
"answer_start": [
230
],
"text": [
"around it"
]
} |
56f9f187f34c681400b0bf04 | Wood | During the development of a tree, the lower limbs often die, but may remain attached for a time, sometimes years. Subsequent layers of growth of the attaching stem are no longer intimately joined with the dead limb, but are grown around it. Hence, dead branches produce knots which are not attached, and likely to drop o... | Are the knots that dead tree limbs form attached or not attached? | {
"answer_start": [
286
],
"text": [
"not attached"
]
} |
56f9f187f34c681400b0bf05 | Wood | During the development of a tree, the lower limbs often die, but may remain attached for a time, sometimes years. Subsequent layers of growth of the attaching stem are no longer intimately joined with the dead limb, but are grown around it. Hence, dead branches produce knots which are not attached, and likely to drop o... | A detached knot will probably drop out of the wood when someone saws it into what? | {
"answer_start": [
357
],
"text": [
"boards"
]
} |
56f9f2568f12f3190063000b | Wood | In grading lumber and structural timber, knots are classified according to their form, size, soundness, and the firmness with which they are held in place. This firmness is affected by, among other factors, the length of time for which the branch was dead while the attaching stem continued to grow. | What's the process in which knots are classified called? | {
"answer_start": [
3
],
"text": [
"grading"
]
} |
56f9f2568f12f3190063000c | Wood | In grading lumber and structural timber, knots are classified according to their form, size, soundness, and the firmness with which they are held in place. This firmness is affected by, among other factors, the length of time for which the branch was dead while the attaching stem continued to grow. | Along with firmness, soundness, and form, what property of a knot is classified? | {
"answer_start": [
87
],
"text": [
"size"
]
} |
56f9f2568f12f3190063000d | Wood | In grading lumber and structural timber, knots are classified according to their form, size, soundness, and the firmness with which they are held in place. This firmness is affected by, among other factors, the length of time for which the branch was dead while the attaching stem continued to grow. | What property of knots does the amount of time a branch stayed on a tree while the stem kept growing affect? | {
"answer_start": [
161
],
"text": [
"firmness"
]
} |
56f9f63b8f12f31900630011 | Wood | Knots do not necessarily influence the stiffness of structural timber, this will depend on the size and location. Stiffness and elastic strength are more dependent upon the sound wood than upon localized defects. The breaking strength is very susceptible to defects. Sound knots do not weaken wood when subject to compre... | What is wood's breaking strength susceptible to? | {
"answer_start": [
258
],
"text": [
"defects"
]
} |
56f9f63b8f12f31900630012 | Wood | Knots do not necessarily influence the stiffness of structural timber, this will depend on the size and location. Stiffness and elastic strength are more dependent upon the sound wood than upon localized defects. The breaking strength is very susceptible to defects. Sound knots do not weaken wood when subject to compre... | Depending on the placement and size of a knot, what property of structural timber can be affected? | {
"answer_start": [
39
],
"text": [
"stiffness"
]
} |
56f9f63b8f12f31900630013 | Wood | Knots do not necessarily influence the stiffness of structural timber, this will depend on the size and location. Stiffness and elastic strength are more dependent upon the sound wood than upon localized defects. The breaking strength is very susceptible to defects. Sound knots do not weaken wood when subject to compre... | What do stiffness and elastic strength depend on more than defects? | {
"answer_start": [
173
],
"text": [
"sound wood"
]
} |
56f9f63b8f12f31900630014 | Wood | Knots do not necessarily influence the stiffness of structural timber, this will depend on the size and location. Stiffness and elastic strength are more dependent upon the sound wood than upon localized defects. The breaking strength is very susceptible to defects. Sound knots do not weaken wood when subject to compre... | What direction of compression in relation to its grain won't weaken wood with sound knots in it? | {
"answer_start": [
326
],
"text": [
"parallel"
]
} |
56f9f78c8f12f31900630019 | Wood | In some decorative applications, wood with knots may be desirable to add visual interest. In applications where wood is painted, such as skirting boards, fascia boards, door frames and furniture, resins present in the timber may continue to 'bleed' through to the surface of a knot for months or even years after manufac... | What positive visual component can knots sometimes add to decorative pieces? | {
"answer_start": [
80
],
"text": [
"interest"
]
} |
56f9f78c8f12f3190063001a | Wood | In some decorative applications, wood with knots may be desirable to add visual interest. In applications where wood is painted, such as skirting boards, fascia boards, door frames and furniture, resins present in the timber may continue to 'bleed' through to the surface of a knot for months or even years after manufac... | What term is used to describe what knots can do to affect the finish of things made from wood even when they've been painted? | {
"answer_start": [
242
],
"text": [
"bleed"
]
} |
56f9f78c8f12f3190063001b | Wood | In some decorative applications, wood with knots may be desirable to add visual interest. In applications where wood is painted, such as skirting boards, fascia boards, door frames and furniture, resins present in the timber may continue to 'bleed' through to the surface of a knot for months or even years after manufac... | Is bleed easy or difficult to control? | {
"answer_start": [
481
],
"text": [
"difficult"
]
} |
56f9f78c8f12f3190063001c | Wood | In some decorative applications, wood with knots may be desirable to add visual interest. In applications where wood is painted, such as skirting boards, fascia boards, door frames and furniture, resins present in the timber may continue to 'bleed' through to the surface of a knot for months or even years after manufac... | The stain from a knot bleeding is usually brownish or what other color? | {
"answer_start": [
339
],
"text": [
"yellow"
]
} |
56f9f78c8f12f3190063001d | Wood | In some decorative applications, wood with knots may be desirable to add visual interest. In applications where wood is painted, such as skirting boards, fascia boards, door frames and furniture, resins present in the timber may continue to 'bleed' through to the surface of a knot for months or even years after manufac... | In what stage of processing does knot primer need to be applied for maximum effectiveness? | {
"answer_start": [
423
],
"text": [
"preparation"
]
} |
56f9f869f34c681400b0bf15 | Wood | Heartwood (or duramen) is wood that as a result of a naturally occurring chemical transformation has become more resistant to decay. Heartwood formation occurs spontaneously (it is a genetically programmed process). Once heartwood formation is complete, the heartwood is dead. Some uncertainty still exists as to whether... | What's another word for "duramen"? | {
"answer_start": [
0
],
"text": [
"Heartwood"
]
} |
56f9f869f34c681400b0bf16 | Wood | Heartwood (or duramen) is wood that as a result of a naturally occurring chemical transformation has become more resistant to decay. Heartwood formation occurs spontaneously (it is a genetically programmed process). Once heartwood formation is complete, the heartwood is dead. Some uncertainty still exists as to whether... | What is heartwood naturally resistant to? | {
"answer_start": [
126
],
"text": [
"decay"
]
} |
56f9f869f34c681400b0bf17 | Wood | Heartwood (or duramen) is wood that as a result of a naturally occurring chemical transformation has become more resistant to decay. Heartwood formation occurs spontaneously (it is a genetically programmed process). Once heartwood formation is complete, the heartwood is dead. Some uncertainty still exists as to whether... | How does heartwood formation occur due to its being genetically programmed? | {
"answer_start": [
160
],
"text": [
"spontaneously"
]
} |
56f9f869f34c681400b0bf18 | Wood | Heartwood (or duramen) is wood that as a result of a naturally occurring chemical transformation has become more resistant to decay. Heartwood formation occurs spontaneously (it is a genetically programmed process). Once heartwood formation is complete, the heartwood is dead. Some uncertainty still exists as to whether... | What adjective describes fully formed heartwood? | {
"answer_start": [
271
],
"text": [
"dead"
]
} |
56f9f869f34c681400b0bf19 | Wood | Heartwood (or duramen) is wood that as a result of a naturally occurring chemical transformation has become more resistant to decay. Heartwood formation occurs spontaneously (it is a genetically programmed process). Once heartwood formation is complete, the heartwood is dead. Some uncertainty still exists as to whether... | Despite being considered dead, what can heartwood have one chemical reaction to? | {
"answer_start": [
382
],
"text": [
"decay organisms"
]
} |
56f9f994f34c681400b0bf1f | Wood | Heartwood is often visually distinct from the living sapwood, and can be distinguished in a cross-section where the boundary will tend to follow the growth rings. For example, it is sometimes much darker. However, other processes such as decay or insect invasion can also discolor wood, even in woody plants that do not ... | In what part of a tree's cross-section is heartwood visible? | {
"answer_start": [
149
],
"text": [
"growth rings"
]
} |
56f9f994f34c681400b0bf20 | Wood | Heartwood is often visually distinct from the living sapwood, and can be distinguished in a cross-section where the boundary will tend to follow the growth rings. For example, it is sometimes much darker. However, other processes such as decay or insect invasion can also discolor wood, even in woody plants that do not ... | What simple color distinction can heartwood have that makes it stand out from living wood in a tree? | {
"answer_start": [
197
],
"text": [
"darker"
]
} |
56f9f994f34c681400b0bf21 | Wood | Heartwood is often visually distinct from the living sapwood, and can be distinguished in a cross-section where the boundary will tend to follow the growth rings. For example, it is sometimes much darker. However, other processes such as decay or insect invasion can also discolor wood, even in woody plants that do not ... | Along with insect infestation, what process can discolor wood and make it look like heartwood? | {
"answer_start": [
238
],
"text": [
"decay"
]
} |
56f9f994f34c681400b0bf22 | Wood | Heartwood is often visually distinct from the living sapwood, and can be distinguished in a cross-section where the boundary will tend to follow the growth rings. For example, it is sometimes much darker. However, other processes such as decay or insect invasion can also discolor wood, even in woody plants that do not ... | What kind of plants never form heartwood? | {
"answer_start": [
295
],
"text": [
"woody"
]
} |
56f9f994f34c681400b0bf23 | Wood | Heartwood is often visually distinct from the living sapwood, and can be distinguished in a cross-section where the boundary will tend to follow the growth rings. For example, it is sometimes much darker. However, other processes such as decay or insect invasion can also discolor wood, even in woody plants that do not ... | What is the living wood in a tree called? | {
"answer_start": [
53
],
"text": [
"sapwood"
]
} |
56f9fb8df34c681400b0bf29 | Wood | Sapwood (or alburnum) is the younger, outermost wood; in the growing tree it is living wood, and its principal functions are to conduct water from the roots to the leaves and to store up and give back according to the season the reserves prepared in the leaves. However, by the time they become competent to conduct wate... | What term is interchangeable with "sapwood"? | {
"answer_start": [
12
],
"text": [
"alburnum"
]
} |
56f9fb8df34c681400b0bf2a | Wood | Sapwood (or alburnum) is the younger, outermost wood; in the growing tree it is living wood, and its principal functions are to conduct water from the roots to the leaves and to store up and give back according to the season the reserves prepared in the leaves. However, by the time they become competent to conduct wate... | Is sapwood the younger or older wood in a tree? | {
"answer_start": [
29
],
"text": [
"younger"
]
} |
56f9fb8df34c681400b0bf2b | Wood | Sapwood (or alburnum) is the younger, outermost wood; in the growing tree it is living wood, and its principal functions are to conduct water from the roots to the leaves and to store up and give back according to the season the reserves prepared in the leaves. However, by the time they become competent to conduct wate... | What essential liquid is the sapwood tasked with carrying around a tree? | {
"answer_start": [
136
],
"text": [
"water"
]
} |
56f9fb8df34c681400b0bf2c | Wood | Sapwood (or alburnum) is the younger, outermost wood; in the growing tree it is living wood, and its principal functions are to conduct water from the roots to the leaves and to store up and give back according to the season the reserves prepared in the leaves. However, by the time they become competent to conduct wate... | How much of the wood in a tree is sapwood at some point in its life? | {
"answer_start": [
428
],
"text": [
"All"
]
} |
56f9fb8df34c681400b0bf2d | Wood | Sapwood (or alburnum) is the younger, outermost wood; in the growing tree it is living wood, and its principal functions are to conduct water from the roots to the leaves and to store up and give back according to the season the reserves prepared in the leaves. However, by the time they become competent to conduct wate... | Does a tree growing quickly out in the open have thinner or thicker sapwood for its size than the same kind of tree in a dense forest? | {
"answer_start": [
630
],
"text": [
"thicker"
]
} |
56f9fcfbf34c681400b0bf33 | Wood | The term heartwood derives solely from its position and not from any vital importance to the tree. This is evidenced by the fact that a tree can thrive with its heart completely decayed. Some species begin to form heartwood very early in life, so having only a thin layer of live sapwood, while in others the change come... | If a tree starts forming heartwood right away, will its sapwood layer be thin or thick? | {
"answer_start": [
261
],
"text": [
"thin"
]
} |
56f9fcfbf34c681400b0bf34 | Wood | The term heartwood derives solely from its position and not from any vital importance to the tree. This is evidenced by the fact that a tree can thrive with its heart completely decayed. Some species begin to form heartwood very early in life, so having only a thin layer of live sapwood, while in others the change come... | What property of heartwood that has nothing to do with how important it is to trees got it its name? | {
"answer_start": [
43
],
"text": [
"position"
]
} |
56f9fcfbf34c681400b0bf35 | Wood | The term heartwood derives solely from its position and not from any vital importance to the tree. This is evidenced by the fact that a tree can thrive with its heart completely decayed. Some species begin to form heartwood very early in life, so having only a thin layer of live sapwood, while in others the change come... | Does a beech tree usually have thin or thick sapwood? | {
"answer_start": [
501
],
"text": [
"thick"
]
} |
56f9fcfbf34c681400b0bf36 | Wood | The term heartwood derives solely from its position and not from any vital importance to the tree. This is evidenced by the fact that a tree can thrive with its heart completely decayed. Some species begin to form heartwood very early in life, so having only a thin layer of live sapwood, while in others the change come... | Does a sassafras tree typically have a thin or thick sapwood layer? | {
"answer_start": [
330
],
"text": [
"Thin"
]
} |
56f9fcfbf34c681400b0bf37 | Wood | The term heartwood derives solely from its position and not from any vital importance to the tree. This is evidenced by the fact that a tree can thrive with its heart completely decayed. Some species begin to form heartwood very early in life, so having only a thin layer of live sapwood, while in others the change come... | Would a thin or a thick sapwood layer be found in a pine tree? | {
"answer_start": [
501
],
"text": [
"thick"
]
} |
56f9fe9b8f12f31900630047 | Wood | No definite relation exists between the annual rings of growth and the amount of sapwood. Within the same species the cross-sectional area of the sapwood is very roughly proportional to the size of the crown of the tree. If the rings are narrow, more of them are required than where they are wide. As the tree gets large... | What part of a tree is the cross-sectional area of the sapwood approximately proportional to? | {
"answer_start": [
202
],
"text": [
"crown"
]
} |
56f9fe9b8f12f31900630048 | Wood | No definite relation exists between the annual rings of growth and the amount of sapwood. Within the same species the cross-sectional area of the sapwood is very roughly proportional to the size of the crown of the tree. If the rings are narrow, more of them are required than where they are wide. As the tree gets large... | Are more rings necessary if they're narrow or wide? | {
"answer_start": [
238
],
"text": [
"narrow"
]
} |
56f9fe9b8f12f31900630049 | Wood | No definite relation exists between the annual rings of growth and the amount of sapwood. Within the same species the cross-sectional area of the sapwood is very roughly proportional to the size of the crown of the tree. If the rings are narrow, more of them are required than where they are wide. As the tree gets large... | As a tree grows bigger, if the sapwood layer doesn't increase in volume, what will it become? | {
"answer_start": [
359
],
"text": [
"thinner"
]
} |
56f9fe9b8f12f3190063004a | Wood | No definite relation exists between the annual rings of growth and the amount of sapwood. Within the same species the cross-sectional area of the sapwood is very roughly proportional to the size of the crown of the tree. If the rings are narrow, more of them are required than where they are wide. As the tree gets large... | In what part of the tree trunk is the sapwood layer thinnest? | {
"answer_start": [
469
],
"text": [
"near the base"
]
} |
56f9fe9b8f12f3190063004b | Wood | No definite relation exists between the annual rings of growth and the amount of sapwood. Within the same species the cross-sectional area of the sapwood is very roughly proportional to the size of the crown of the tree. If the rings are narrow, more of them are required than where they are wide. As the tree gets large... | Along with the smaller diameter of the upper trunk, what factor leads to thinner sapwood higher up a tree? | {
"answer_start": [
496
],
"text": [
"age"
]
} |
56fa00f28f12f31900630051 | Wood | When a tree is very young it is covered with limbs almost, if not entirely, to the ground, but as it grows older some or all of them will eventually die and are either broken off or fall off. Subsequent growth of wood may completely conceal the stubs which will however remain as knots. No matter how smooth and clear a ... | What usually covers the whole trunk of a very young tree? | {
"answer_start": [
45
],
"text": [
"limbs"
]
} |
56fa00f28f12f31900630052 | Wood | When a tree is very young it is covered with limbs almost, if not entirely, to the ground, but as it grows older some or all of them will eventually die and are either broken off or fall off. Subsequent growth of wood may completely conceal the stubs which will however remain as knots. No matter how smooth and clear a ... | What evidence of the stubs of the limbs a tree loses can always be seen in the wood? | {
"answer_start": [
280
],
"text": [
"knots"
]
} |
56fa00f28f12f31900630053 | Wood | When a tree is very young it is covered with limbs almost, if not entirely, to the ground, but as it grows older some or all of them will eventually die and are either broken off or fall off. Subsequent growth of wood may completely conceal the stubs which will however remain as knots. No matter how smooth and clear a ... | In a very old tree, are you more likely to find a lot of knots in the heartwood or the sapwood? | {
"answer_start": [
509
],
"text": [
"heartwood"
]
} |
56fa00f28f12f31900630054 | Wood | When a tree is very young it is covered with limbs almost, if not entirely, to the ground, but as it grows older some or all of them will eventually die and are either broken off or fall off. Subsequent growth of wood may completely conceal the stubs which will however remain as knots. No matter how smooth and clear a ... | What hides the stubs of a tree's lost limbs from being visible later in its life? | {
"answer_start": [
192
],
"text": [
"Subsequent growth"
]
} |
56fa00f28f12f31900630055 | Wood | When a tree is very young it is covered with limbs almost, if not entirely, to the ground, but as it grows older some or all of them will eventually die and are either broken off or fall off. Subsequent growth of wood may completely conceal the stubs which will however remain as knots. No matter how smooth and clear a ... | Since knots are defects that weaken lumber, would the heartwood or the sapwood from the same tree be stronger? | {
"answer_start": [
683
],
"text": [
"sapwood"
]
} |
56fa02638f12f3190063006d | Wood | It is remarkable that the inner heartwood of old trees remains as sound as it usually does, since in many cases it is hundreds, and in a few instances thousands, of years old. Every broken limb or root, or deep wound from fire, insects, or falling timber, may afford an entrance for decay, which, once started, may penet... | What do broken limbs and deep wounds open a door for in a tree? | {
"answer_start": [
283
],
"text": [
"decay"
]
} |
56fa02638f12f3190063006e | Wood | It is remarkable that the inner heartwood of old trees remains as sound as it usually does, since in many cases it is hundreds, and in a few instances thousands, of years old. Every broken limb or root, or deep wound from fire, insects, or falling timber, may afford an entrance for decay, which, once started, may penet... | Decay can spread to all of what part of a tree? | {
"answer_start": [
341
],
"text": [
"the trunk"
]
} |
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