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bd6784444af303e45ce98b38ce623542384a0e28
the above equation is nothing but emden–chandrasekhar equation,
the above equation is nothing but emden–chandrasekhar equation, which appears in astrophysics describing isothermal gas sphere. unlike planar and cylindrical case, the spherical vessel has infinitely many solutions for δ < δ c {\displaystyle \delta <\delta _{c}} oscillating about the point δ = 2 {\displaystyle \delta =...
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be2a8b731f632af2c19dab1520e2de3715d68d6e
if the transformations Θ = θ m −
if the transformations Θ = θ m − θ {\displaystyle \theta =\theta _{m}-\theta } and ξ 2 = δ e θ m η 2 {\displaystyle \xi ^{2}=\delta e^{\theta _{m}}\eta ^{2}}, where θ m {\displaystyle \theta _{m}} is the maximum temperature which occurs at η = 0 {\displaystyle \eta =0} due to symmetry, are introduced
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ca7fe5a9f640c9e447036348c70a086e4f1db468
for each value of δ {\displaystyle \delta },
for each value of δ {\displaystyle \delta }, we have two values of θ m {\displaystyle \theta _{m}} since b {\displaystyle b} is multi-valued. the maximum critical temperature is θ m, c = ln 4 {\displaystyle \theta _{m,c}=\ln 4}.
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23e6de8a4d3bc0d8aaf03cd81f215234bebeb3d7
now if we use the other boundary condition
now if we use the other boundary condition θ (1) = 0 {\displaystyle \theta (1)=0}, we get an equation for b {\displaystyle b} as δ (b + 1) 2 − 8 b = 0 {\displaystyle \delta (b+1)^{2}-8b=0}. the maximum value of δ {\displaystyle \delta } for which solution is possible is when b = 1 {\displaystyle b=1}, so the critical f...
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65f462f40966defed8dde6473b2ed019fad0409e
integrating once again, we have θ = a
integrating once again, we have θ = a − 2 ln (b η 2 + 1) {\displaystyle \theta =a-2\ln(b\eta ^{2}+1)} where b = 1 / b ′ {\displaystyle b=1/b'}. we have used already one boundary condition, there is one more boundary condition left, but with two constants a, b {\displaystyle a,\ b}. it turns out a {\displaystyle a} and ...
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1897b84909c7fd18b5429f9e09fbf7781e2cce91
the general solution is ω 2 + 4
the general solution is ω 2 + 4 ω + c = − 2 δ χ {\displaystyle \omega ^{2}+4\omega +c=-2\delta \chi }. but c = 0 {\displaystyle c=0} from the symmetry condition at the centre. writing back in original variable, the equation reads,
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3922b1d9786bd7ba359a63ac4b5dd70232518214
if the transformations ω = η d θ
if the transformations ω = η d θ / d η {\displaystyle \omega =\eta d\theta /d\eta } and χ = e θ η 2 {\displaystyle \chi =e^{\theta }\eta ^{2}} are introduced
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fbb97ef4f2b95c3a69c339b32aae333c409ee95c
for cylindrical vessel, there is an exact solution.
for cylindrical vessel, there is an exact solution. though frank-kamentskii used numerical integration assuming there is no explicit solution, paul l. chambré provided an exact solution in 1952. h. lemke also solved provided a solution in a somewhat different form in 1913. here j = 1 {\displaystyle j=1}, then
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4a7bd9042dc0e933514b41e6c430723ec6e80a92
so the critical frank-kamentskii parameter is δ c
so the critical frank-kamentskii parameter is δ c = 0.8785 {\displaystyle \delta _{c}=0.8785}. the system has no steady state (or explodes) for δ > δ c = 0.8785 {\displaystyle \delta >\delta _{c}=0.8785} and for δ < δ c = 0.8785 {\displaystyle \delta <\delta _{c}=0.8785}, the system goes to a steady state with very slo...
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9e2e0a52944cc544bc155f78d64bf720c877e2ea
critical δ c {\displaystyle \delta _{c}} is obtained
critical δ c {\displaystyle \delta _{c}} is obtained by finding the maximum point of the equation (see figure), i.e., d δ / d θ m = 0 {\displaystyle d\delta /d\theta _{m}=0} at δ c {\displaystyle \delta _{c}}.
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d79ba39aed8caad7e9271868ea2477498e668a9d
the above equation is the exact solution, but
the above equation is the exact solution, but θ m {\displaystyle \theta _{m}} maximum temperature is unknown, but we have not used the boundary condition of the wall yet. thus using the wall boundary condition θ = 0 {\displaystyle \theta =0} at η = 1 {\displaystyle \eta =1}, the maximum temperature is obtained from an ...
wikipedia
be2a8b731f632af2c19dab1520e2de3715d68d6e
if the transformations Θ = θ m −
if the transformations Θ = θ m − θ {\displaystyle \theta =\theta _{m}-\theta } and ξ 2 = δ e θ m η 2 {\displaystyle \xi ^{2}=\delta e^{\theta _{m}}\eta ^{2}}, where θ m {\displaystyle \theta _{m}} is the maximum temperature which occurs at η = 0 {\displaystyle \eta =0} due to symmetry, are introduced
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bea90642383eb62ffa1a0eb27c471bbd6767e5e6
the only parameter which characterizes the explosion is
the only parameter which characterizes the explosion is the damköhler number δ {\displaystyle \delta }. when δ {\displaystyle \delta } is very high, conduction time is longer than the chemical reaction time and the system explodes with high temperature since there is not enough time for conduction to remove the heat. o...
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76b95e22cdcc2b39910c37e00e974fc314ce829c
which implies that the ignition time τ →
which implies that the ignition time τ → ∞ {\displaystyle \tau \rightarrow \infty } as δ − δ c → 0 + {\displaystyle \delta -\delta _{c}\rightarrow 0^{+}} with a square-root singularity.
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437f08a70b38d1979a41a738c3fe09dcd7b5d3a4
which immediately reveals that ψ → ∞ {\displaystyle
which immediately reveals that ψ → ∞ {\displaystyle \psi \rightarrow \infty } when ζ = 2 π δ c. {\displaystyle \zeta ={\sqrt {2}}\pi \delta _{c}.} writing this condition in terms of τ {\displaystyle \tau }, the explosion time in the near-critical condition is found to be
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fc97961a21a79988de047b06fc51149be92eaa2d
in the near-critical condition, i.e., when δ −
in the near-critical condition, i.e., when δ − δ c → 0 + {\displaystyle \delta -\delta _{c}\rightarrow 0^{+}}, the system takes very long time to explode. the analysis for this limit was first carried out by frank-kamenetskii., although proper asymptotics were carried out only later by d. r. kassoy and amable liñán inc...
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be1a495fbb6b1c72e12a41585d742c9b321b6754
at time τ = 1 {\displaystyle \tau =1},
at time τ = 1 {\displaystyle \tau =1}, the system explodes. this time is also referred to as the adiabatic induction period since the heat conduction term − θ / δ {\displaystyle -\theta /\delta } is neglected.
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e97a48626d4b4e36c51bbef56c72e9afca0655ad
for δ c < δ < ∞ {\displaystyle
for δ c < δ < ∞ {\displaystyle \delta _{c}<\delta <\infty }, the system explodes since the exponential term dominates as time proceeds. we do not need to wait for a long time for θ {\displaystyle \theta } to blow up. because of the exponential forcing, θ → ∞ {\displaystyle \theta \rightarrow \infty } at a finite value ...
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df69979b2266b25c4670dcaa91dcd22364449f3e
where w {\displaystyle w} represents the lambert w
where w {\displaystyle w} represents the lambert w function. from the properties of lambert w function, it is easy to see that the steady state temperature provided by the above equation exists only when δ ≤ δ c = 1 / e {\displaystyle \delta \leq \delta _{c}=1/e}, where δ c {\displaystyle \delta _{c}} is called as fran...
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b87e0768fbb8f75f80011c5cba3fc8bedf94f221
when 0 < δ < e − 1
when 0 < δ < e − 1 {\displaystyle 0<\delta <e^{-1}}, the linear term eventually dominates and the system is able to reach a steady state as τ → ∞ {\displaystyle \tau \rightarrow \infty }. at steady state (d θ / d τ = 0 {\displaystyle d\theta /d\tau =0}), the balance is given by the equation
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f5b1b8a17a17592f7ce305cd10aa95dfe77dc1a9
in which the exponential term e θ {\displaystyle
in which the exponential term e θ {\displaystyle e^{\theta }} will tend to increase θ {\displaystyle \theta } as time proceeds whereas the linear term − θ / δ {\displaystyle -\theta /\delta } will tend to decrease θ {\displaystyle \theta }. the relevant importance between the two terms are determined by the damköhler n...
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55ee93552885912fe811f076b89ecef6b0c497c8
before frank-kamenetskii, his doctoral advisor nikolay semyonov (or
before frank-kamenetskii, his doctoral advisor nikolay semyonov (or semenov) proposed a thermal explosion theory with a simpler model with which he assumed a linear function for the heat conduction process instead of the laplacian operator. semenov's equation reads as
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19472e428071d8c2c0620de81d404f58392d8d3a
at τ = 0 {\displaystyle \tau =0}, we
at τ = 0 {\displaystyle \tau =0}, we have θ (η, 0) = 0 {\displaystyle \theta (\eta,0)=0} and for τ > 0 {\displaystyle \tau >0}, θ {\displaystyle \theta } needs to satisfy θ (1, τ) = 0 {\displaystyle \theta (1,\tau)=0} and ∂ θ / ∂ η | η = 0 = 0. {\displaystyle \partial \theta /\partial \eta |_{\eta =0}=0.}
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b185fd3a7c52bdc27a9217195cb6fc27b8e72609
since β ≫ 1 {\displaystyle \beta \gg 1},
since β ≫ 1 {\displaystyle \beta \gg 1}, the exponential term can be linearized e θ / (1 + θ / β) ≈ e θ {\displaystyle e^{\theta /(1+\theta /\beta)}\approx e^{\theta }}, hence
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d616cb45a3b0562461882c91b9482765c3fd4ba4
an increment in temperature of order t −
an increment in temperature of order t − t o ∼ r t o 2 / e {\displaystyle t-t_{o}\sim rt_{o}^{2}/e}, where r t o 2 / e {\displaystyle rt_{o}^{2}/e} is the frank-kamenetskii temperature is enough to increase the chemical reaction by amount e {\displaystyle e}, as is evident from the ratio
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94ab9d2d0e4b5cb7f17d42d3c19c8652ac6eb314
consider a vessel maintained at a constant temperature
consider a vessel maintained at a constant temperature t o {\displaystyle t_{o}}, containing a homogeneous reacting mixture. let the characteristic size of the vessel be a {\displaystyle a}. since the mixture is homogeneous, the density ρ {\displaystyle \rho } is constant. during the initial period of ignition, the con...
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125d56c10f9ee787caa311db540e9cd82e04489d
in combustion, frank-kamenetskii theory explains the thermal explosion
in combustion, frank-kamenetskii theory explains the thermal explosion of a homogeneous mixture of reactants, kept inside a closed vessel with constant temperature walls. it is named after a russian scientist david a. frank-kamenetskii, who along with nikolay semenov developed the theory in the 1930s.
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25fca8c6969cb61621fdeda39ffaeb5732f59901
lương duy cương is a vietnamese professional footballer
lương duy cương is a vietnamese professional footballer who plays as a centre back or a right back for v.league 1 club shb Đà nẵng and the vietnam national team. at the 2022 afc u-23 asian cup, he was also used as a defensive midfielder.
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9169b0123871c8fdb09661aad854620daa807267
lương duy cương (born 7 november 2001) is
lương duy cương (born 7 november 2001) is a vietnamese professional footballer who plays as a centre back or a right back for v.league 1 club shb Đà nẵng and the vietnam national team.
wikipedia
7142ee88f97c1ca8f1c059452b20fb7dec1662e7
ernest a. calverley was an american professional basketball
ernest a. calverley was an american professional basketball player. he was an all-american while playing for the university of rhode island. he played professionally with the providence steamrollers of the basketball association of america for three seasons from 1946 to 1949. calverley led the league in assists and was...
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cf5094541f4f4003cb30336acd11b21b30090e4e
he later returned to uri to coach the
he later returned to uri to coach the rams and led them to two ncaa division i men's basketball tournament appearances in 1961 and 1966, losing both times in the first round. calverely died of complications of an infection after insertion of a pacemaker on october 20, 2003.
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03e585ea5c97097e7a244c1e4dce2d5630b55114
calverley led in assists per game in the
calverley led in assists per game in the league's first and second years, while playing for his home state team, the providence steamrollers. in his rookie season, calverley was selected to the all-baa second team. in his career, he missed only three games (one for each season). he had a 70.7% free throw percentage, wh...
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b66df1a53ff19049794f9b9d1dc591cb31cbdaf9
calverley was retroactively declared the men's basketball season
calverley was retroactively declared the men's basketball season scoring leader for 1944. but calverley was most notable for one particular shot. dubbed the "shot heard round the world", it was a midcourt shot from 62 feet away, as time expired at madison square garden in the 1946 national invitation tournament against...
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60a672c4768080c26a4e66059e1c44758734db79
ernest a. calverley (january 30, 1924 – october
ernest a. calverley (january 30, 1924 – october 20, 2003) was an american professional basketball player. he was an all-american while playing for the university of rhode island. he played professionally with the providence steamrollers of the basketball association of america for three seasons from 1946 to 1949. calve...
wikipedia
9591cafc343cf2f046851f700c78ba1ddb6f40b7
the 2023 north alabama lions football team represented
the 2023 north alabama lions football team represented the university of north alabama as a member of the united athletic conference during the 2023 ncaa division i fcs football season. led by first-year head coach brent dearmon, the lions played home games at the braly municipal stadium in florence, alabama.
wikipedia
9591cafc343cf2f046851f700c78ba1ddb6f40b7
the 2023 north alabama lions football team represented
the 2023 north alabama lions football team represented the university of north alabama as a member of the united athletic conference during the 2023 ncaa division i fcs football season. led by first-year head coach brent dearmon, the lions played home games at the braly municipal stadium in florence, alabama.
wikipedia
72c1036c01f85baf134b6d88e3ee3f447c87c15d
charles john priefer is an american former football
charles john priefer is an american former football coach who held a variety of defensive and special teams coaching positions at the college and professional levels of the sport, including 17 seasons in the national football league (nfl). he attended boromeo high school in wickliffe, ohio before matriculating to john ...
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597a08603bb15c2f0a37a4bf1b43cc4f44368b95
priefer has helped mold pro bowl defensive tackle
priefer has helped mold pro bowl defensive tackle shaun rogers into an impressive kick-blocking force. since rogers arrived as a rookie in 2001, detroit has blocked a total of 13 kicks, eight by rogers. in 2005, rogers notched his seventh career blocked field goal when he re-directed a john kasay 52-yard attempt vs. ca...
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2d50e5041ad8f7ff18f7f853f53f02fc0c54a29c
in 2004, the lions posted a single-season franchise
in 2004, the lions posted a single-season franchise record with five special teams return touchdowns. the previous record of four special teams return touchdowns was accomplished five times, with two of them coming under priefer's guidance (1951, 1992, 1994, 2002, and 2003).
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c5b528805d5e060dbc48a0ddf12379f21962ce0c
priefer has formulated a superb combination of talent
priefer has formulated a superb combination of talent and scheme in developing the lions' return game into a force. five players have scored touchdowns on returns during priefer's tenure in detroit. in 1998, he guided terry fair to a league best 28.0 yards per kickoff average. in 2000, desmond howard's prolific punt an...
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4913125efcb3c96f84e5f8be18cebd6fcf7b296c
chuck priefer has solidified the lions' cover teams
chuck priefer has solidified the lions' cover teams among the best in the nfl over the past few seasons. in 2004, the lions finished third in the nfl in average drive start following kickoff (kickoff team) with 24.3, four yards below the league average, including 14 touchbacks and 18 stops inside-the-20. the lions tied...
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2b7066b409ad2e6968b8ba2b64ad42246e8442ab
priefer originally joined the lions in 1997, moving
priefer originally joined the lions in 1997, moving along with head coach bobby ross from the san diego chargers. he was then retained as special teams coordinator by gary moeller, marty mornhinweg, steve mariucci, dick jauron, and rod marinelli. he ultimately served under six lions head coaches.
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aac4ce5260950c48f659ed4c8d5a56399bc60efa
at the end of the detroit lions '
at the end of the detroit lions ' 2006 nfl season, head coach rod marinelli announced that special teams coach chuck priefer would be retiring, at the age of 65. priefer spoke shortly after marinelli, and confirmed his retirement, telling the media that he is ready to spend time with his wife, and after 44 years of coa...
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8676a235b60b39f8aac37b13ce84227375072773
during priefer's nine-year tenure in detroit, he has
during priefer's nine-year tenure in detroit, he has had five different players return kicks for touchdowns (terry fair, desmond howard, az-zahir hakim, eddie drummond and reggie swinton). howard and drummond both earned trips to the 2001 and 2005 pro bowls respectively.
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8c2b451efe79b9cb19259ea5a4325d2b665f7dc1
over the past four years, the lions special
over the past four years, the lions special teams return units have been the best in the nfl when it comes to scoring touchdowns. from 2002 to 2005, the lions recorded more special teams return touchdowns (kickoff return, punt return, blocked punt return and blocked field goal return) than any other team in the nfl. ov...
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817eb3e22725b84efd5521df6c15d49a15f4145b
punter nick harris enjoyed his finest nfl season
punter nick harris enjoyed his finest nfl season in his second full year under priefer. harris' career-high 34 punts downed inside-the-20 in 2005 led the nfl and was the best single-season mark in franchise history. he also tied for the second-fewest touchbacks in the nfl with two, which gave him the best net different...
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7800276ec707c7f061a30c5e1316845498d9341a
since the arrival of priefer in 1997, the
since the arrival of priefer in 1997, the lions have seen a noticeable upturn in production from k jason hanson, who scored his 1,400th career point in 2005, as well as with its "hard core" coverage units. hanson has enjoyed nine outstanding seasons under priefer's direction, being named to the pro bowl following both ...
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92bf89e8ab621f8db0f77854a15e0f013f5a05b6
while at san diego, the chargers' special teams
while at san diego, the chargers' special teams under priefer also consistently ranked among the best in the nfl. kr darrien gordon led the afc and was second in the nfl with a 14.9-yard punt return average. in 1994, return specialist andre coleman became the first player in chargers' history to return two kickoffs for...
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f34ee02d522d06a58b62de45d802cc733feb1422
priefer possesses 29 years of college and pro
priefer possesses 29 years of college and pro coaching experience on his resume. priefer coached the defensive backfield at georgia tech from 1987 to 1991 and went on to san diego in 1992. prior to his tenure at georgia tech, priefer spent the 1986 season as the defensive coordinator at kent state.
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63941aaf64ba184d70b3df0ea6aeca2629c9e8fe
priefer began his coaching career at padua franciscan
priefer began his coaching career at padua franciscan high school in parma, ohio as an assistant football, baseball and basketball coach in 1963. he was named head baseball coach in 1965 and assistant athletic director in 1966. from 1972 to 1976 he was the head football coach, posting a 34-15 record. in 1977, he jumped...
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0a1061e5a3b2d4539827079f18b4d25776bdd8f5
he attended boromeo high school in wickliffe, ohio
he attended boromeo high school in wickliffe, ohio before matriculating to john carroll university. he graduated from john carroll in 1963 with a degree in history and latin and earned a master's degree in american history (emphasis in american-russian relations) from john carroll in 1967. priefer is the father of nfl ...
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2b59f5a4a428a3db3a24d331b54d64d526d673d7
charles john priefer (born july 26, 1941) is
charles john priefer (born july 26, 1941) is an american former football coach who held a variety of defensive and special teams coaching positions at the college and professional levels of the sport, including 17 seasons in the national football league (nfl).
wikipedia
78b6fe8e68fcc45f3a0ce15a14851c7a15f90913
li returned to china in 1985 and continued
li returned to china in 1985 and continued to teach at wuhan institute of surveying and mapping. he was promoted to full professor in october 1986. he moved up the ranks to become president in february 1997, a position in which he remained until july 2000. he was recruited as dean of the school of environment and spati...
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1b42c3f3f147e0d3590651f7821f8bc2d70e2715
after resuming the college entrance examination 1978, li
after resuming the college entrance examination 1978, li did his postgraduate work at wuhan institute of surveying and mapping. he pursued further studies in federal germany, first studying at the university of bonn in 1982 and then earning a doctor's degree degree from the university of stuttgart under the supervision...
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5433ff6f63dce27fc4b677c3bd01197c5cb5fce8
after graduation in 1963, li was dispatched to
after graduation in 1963, li was dispatched to the state bureau of surveying and mapping and reassigned to the shijiazhuang cement products factory in january 1971. in october 1975, he became an engineer at hebei provincial bureau of surveying and mapping.
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748cdb4fc327d13c0d47fc1bef70f43853287279
li was born in tai county, jiangsu, on
li was born in tai county, jiangsu, on 31 december 1939, while his ancestral home in dantu district of zhenjiang. his younger brother li deyi is an academician of the chinese academy of engineering. his younger cousin brother li dequn is also an academician of the chinese academy of engineering.
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8eacd6134bc091e3c57106f7fa50f134ca8bcf8e
li deren (chinese: 李德仁; pinyin: lǐ dérén; born
li deren (chinese: 李德仁; pinyin: lǐ dérén; born 31 december 1939) is a chinese scientist who is a professor at wuhan university, a former president of wuhan university of surveying and mapping technology, and member of the chinese academy of sciences and the chinese academy of engineering.
wikipedia
5bdde5d2cb714a776c2ccc4d0aca823ebbd29e53
mitchell joachim is an architect and urban designer.
mitchell joachim is an architect and urban designer. he is the co-founder of terreform one, and a professor of practice at nyu. previously he was the frank gehry chair at university of toronto and a faculty member at pratt, columbia, syracuse, washington, the new school, and the european graduate school. most of joachi...
wikipedia
975c2a2b4d3d679e1c71b949f1f13a958d8f2d8c
in 2006, mitchell joachim co-founded terreform one (open
in 2006, mitchell joachim co-founded terreform one (open network ecology), a 501c3 nonprofit organization that focuses on biotech architecture and ecological urban planning. terreform one aims to address environmental issues of climate change and biodiversity loss through novel experimental methodologies, engineered li...
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6496b00941c09220e4d017453ff7916466ba6890
in 2002, joachim started his doctoral research with
in 2002, joachim started his doctoral research with the mit media lab 's smart cities group under the leadership of william j. mitchell. this experience allowed him to explore the intersection of computational design and urbanism, focusing on how emerging types of mobility, city cars, and soft vehicles could be leverag...
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1a25543849d5a95b3123117cf2b80372510c2578
the mentorship and collaboration with these two renowned
the mentorship and collaboration with these two renowned architects provided joachim with a strong foundation for his career, leading to his recognition in ecological design and sustainable urbanism. joachim's exposure to pei's modernist precision and safdie's humane principles influenced his own innovative projects, s...
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882b32a6bbd133febb13d83684de724b24205528
years later, joachim worked at the architture offices
years later, joachim worked at the architture offices of mohse safdie under an awarded research fellowship. safdie contributed to his ability to push the boundaries of traditional architecture, incorporating analytical tools and socio-ecological principles into designs of tall buildings and clusters.
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318fe92e1723c584acc65fc688d8c7110782709e
early in his career, joachim worked for pei
early in his career, joachim worked for pei cobb freed & partners architects. working with i.m. pei provided joachim with valuable insights into large-scale architectural projects and the integration of contemporary design with historical contexts. his experience allowed him to develop a deep understanding of architect...
wikipedia
c15ff90fd4bf12357094d11564f308f151a7c2dc
mitchell has been awarded a fulbright scholarship, lafargeholcim
mitchell has been awarded a fulbright scholarship, lafargeholcim foundation award, architect r+d award, senior fellowship at ted 2011, moshe safdie and assoc. fellowship, and martin society for sustainability fellowship at mit. he won the zumtobel group award, history channel and infiniti design excellence award for th...
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e6f983a77ea08d1551b88b849ee564ca4156393d
he earned a ph.d. at massachusetts institute of
he earned a ph.d. at massachusetts institute of technology, in the dept. of architecture, design and computation program, a master of architecture in urban design (maud) at harvard graduate school of design (gsd), a m.arch at columbia university gsapp, and a bps at the university at buffalo, the state university of new...
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34906090c0ecb976d3977cdc334cfe0ff48c3dd1
mitchell joachim was born in new jersey to
mitchell joachim was born in new jersey to henry and ellen joachim. henry, a passionate painter, owned a small wood furniture manufacturing business. ellen, mitchell’s mother, played a pivotal role in his upbringing, guiding him alongside henry. in the late '70s, seeking a better quality of life, his parents moved from...
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01bd157bf5ad902c2753f9d73991c1f005502891
most of joachim's projects employ innovative platforms and
most of joachim's projects employ innovative platforms and methods based on living biological matter for fabrication and design purposes. rather than merely drawing inspiration from nature (not biomimicry), these materials are altered, coaxed, or engineered to function in ways that stay living and breathing within the ...
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51d7f6dcd59deb1b695fd7e72600e635db56aa3e
mitchell joachim (pronounced /jo-ak-um/; born february 3, 1972)
mitchell joachim (pronounced /jo-ak-um/; born february 3, 1972) is an architect and urban designer. he is the co-founder of terreform one, and a professor of practice at nyu. previously he was the frank gehry chair at university of toronto and a faculty member at pratt, columbia, syracuse, washington, the new school, a...
wikipedia
653517a42c222fa207ed4f8fe6e94e35291e5ef3
a memorial lecture in harry smith's honour is
a memorial lecture in harry smith's honour is associated with the institute of microbiology & infection at the university of birmingham and is given annually by a world-leading scientist or policymaker in the field of microbiology. previous harry smith memorial lecturers include dame sally davies, professor david holde...
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7049ea8f8794fcda3452718a08296625de7beaef
in 1945, he was appointed assistant professor at
in 1945, he was appointed assistant professor at university college, where he was awarded a phd in biochemistry for the successful conclusion of a research project. in 1947 he became a researcher at the microbiological research establishment at porton down. there he carried out research on the mechanisms of anthrax inf...
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ff6dc99f2f70285868e967e223b0df31bce4917f
he was born in northampton, the son of
he was born in northampton, the son of bookmaker harry smith, was educated at northampton grammar school and earned a degree in pharmacy at university college nottingham in 1942. for the rest of the war he worked at boots in nottingham on the manufacture of pharmaceuticals, and was awarded a bsc in chemistry by the uni...
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6bc8d7a7bb74bddaf6a20c7e8121247ea7c336d8
he and a number of collaborators described the
he and a number of collaborators described the vertebrates in a series of general publications and later books on birds appeared.from all his journeys in north east africa and arabia, it is estimated that rüppell himself described 32 new genera and 450 species of animals, including the semien wolf (canis simensis rüppe...
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23a3a82f4c38d1f76540882a9bddddb19b2eaad0
around 100 new plant species were described in
around 100 new plant species were described in the years 1837-45, due to his collection. the herbarium contains more than 200 specimens and more than 25 species of vascular plants have been named after rüppell.
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f790b73ed6a7b1cf6e7921720468da5aa95125cd
in 1830, rüppell returned to africa, and became
in 1830, rüppell returned to africa, and became the first naturalist to traverse ethiopia (or abyssinia as it was known then). he had been sent by the senckenberg nature research society (senckenberg naturforschende gesellschaft), a learned association based in frankfurt. he was one of the first collectors of old abyss...
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699cd3ec171c00c81bcacc728a88ef9c03bc237e
rüppell returned to europe in 1827, after battling
rüppell returned to europe in 1827, after battling pirates who had occupied his ship for 2 weeks. during his absence, philipp jakob cretzschmar had used specimens sent back by rüppell to produce the atlas zu der reise im nordlichen afrika (atlas of travels in northern africa) (1826). in frankfurt, he published scientif...
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6e588b3b40d25fbd5caee5b5155becced8422457
rüppell set off on his first expedition in
rüppell set off on his first expedition in 1821, accompanied by surgeon michael hey as his assistant. they travelled through the sinai desert, and in 1822, were the first european explorers to reach the gulf of aqaba. they then proceeded to alexandria via mount sinai. in 1823, they travelled up the nile to nubia, colle...
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e248efbafe1c63937eaa464008dcec0953a47123
rüppell was born in frankfurt am main, the
rüppell was born in frankfurt am main, the son of a prosperous banker, who was a partner in 'rüppell und harnier’s bank'. he was originally destined to be a merchant, but after a visit to sinai in 1817, where he met henry salt and the swiss-german traveller ludwig burckhardt. he explored giza and the pyramids with salt...
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4bc65cd120e17af5271f58bb687ec6676e258a30
wilhelm peter eduard simon rüppell, also spelled rueppell
wilhelm peter eduard simon rüppell, also spelled rueppell (20 november 1794 – 10 december 1884) was a german naturalist and explorer, best known for his collections and descriptions of plants and animals from africa and arabia.
wikipedia
86547036480e64a23c934b471c3d689a45ef71a7
a peristaltic pump, also commonly known as a
a peristaltic pump, also commonly known as a roller pump, is a type of positive displacement pump used for pumping a variety of fluids. the fluid is contained in a flexible tube fitted inside a circular pump casing. most peristaltic pumps work through rotary motion, though linear peristaltic pumps have also been made. ...
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00f6cb877fcf60e8aaf4540c23d3a8049409e815
for continuous use, most of the materials perform
for continuous use, most of the materials perform similarly over short time frames. this suggests that overlooked low cost materials such as pvc might meet the needs of a short-term, one time use medical applications. for intermittent use, compression set is important and silicone is an optimal material choice.
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b900ed3298af549c6e03bd13bb71d49d8a20a121
in microfluidics, it is often desirable to minimize
in microfluidics, it is often desirable to minimize the circulating volume of fluid. traditional pumps require a large volume of liquid external to the microfluidic circuit. this can lead to problems due to dilution of analytes and already dilute biological signalling molecules. for this reason, among others, it is des...
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4b0a84ca0a1dadd924130ea65f52b2924283f3c9
lower pressure peristaltic pumps typically have dry casings
lower pressure peristaltic pumps typically have dry casings and use rollers along with non-reinforced, extruded tubing. this class of pump is sometimes called a "tube pump" or "tubing pump". these pumps employ rollers to squeeze the tube. except for a 360° eccentric pump design, these pumps have a minimum of 2 rollers ...
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d526b7d7cd8a93b56944ebd867d8e1682458f35a
the biggest advantage with the hose pumps over
the biggest advantage with the hose pumps over the roller pumps is the high operating pressure of up to 16 bar. with rollers, max pressure can arrive up to 12 bar (170 psi) without any problem. if the high operating pressure is not required, a tubing pump is a better option than a hose pump if the pumped medium is not ...
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259ec1a0c878193c4d7728d503b71701088e5db5
higher pressure peristaltic hose pumps which can typically
higher pressure peristaltic hose pumps which can typically operate against up to 16 bar (230 psi) in continuous service, use shoes (rollers only used on low-pressure types) and have casings filled with lubricant to prevent abrasion of the exterior of the pump tube and to aid in the dissipation of heat, and use reinforc...
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dd12d87604e1bf32404845f0987b64162cf8139a
the flow rate of a peristaltic pump is
the flow rate of a peristaltic pump is in most cases not linear. the effect of pulsation at the inlet of the pump changes the filling degree of the peristaltic hose. with high inlet pulsation, the peristaltic hose may become oval-shaped, resulting in less flow.accurate metering with a peristaltic pump is therefore only...
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b3e364b57e9784fd5b0d41bf3965305fa72b137d
the length of the tube (measured from the
the length of the tube (measured from the initial pinch point near the inlet to the final release point near the outlet) does not affect the flow rate. however, a longer tube implies more pinch points between inlet and outlet, increasing the pressure that the pump can generate.
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fc1b35c14f1f643229f99a9613d02ee5bf5f0b72
increasing the number of rollers does not increase
increasing the number of rollers does not increase the flow rate, instead it will decrease the flow rate somewhat by reducing the effective (i.e. fluid-pumping) circumference of the head. adding rollers does tend to decrease the amplitude of the fluid pulsing at the outlet by increasing the frequency of the pulsed flow...
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ffaec15faa1f23dc8cc51c5533a77e8c61fec26b
thus for a given pump, the most critical
thus for a given pump, the most critical tubing dimension becomes the wall thickness. an interesting point here is that the inside diameter (id) of the tubing is not an important design parameter for the suitability of the tubing for the pump. therefore, it is common for more than one id be used with a pump, as long as...
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8a45ea0eec5578fc75546f04800b3d1d48bc8c00
the minimum gap between the roller and the
the minimum gap between the roller and the housing determines the maximum squeeze applied on the tubing. the amount of squeeze applied to the tubing affects pumping performance and the tube life – more squeezing decreases the tubing life dramatically, while less squeezing can cause the pumped medium to slip back, espec...
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7feda2d55b0ffe5ef52c4866480eeb8a371918a8
while these charts cover a list of commonly
while these charts cover a list of commonly encountered fluids, they may not have all the fluids. if there is a fluid whose compatibility is not listed anywhere, then a common test of compatibility is the immersion testing. a 1 to 2 inch sample of the tubing is immersed in the fluid to be pumped for anywhere from 24 to...
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35badcf9141456388363457c68af04858849a53c
with fluoroelastomer tubing, the elastomer itself has the
with fluoroelastomer tubing, the elastomer itself has the chemical resistance. in the case of e.g. chem-sure, it is made of a perfluoroelastomer, that has the broadest chemical compatibility of all elastomers. the two fluoroelastomer tubes listed above combine the chemical compatibility with a very long tube life stemm...
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aa39d694494efe27d883e467e25e70be2e4e3fce
with lined tubing, the thin inside liner is
with lined tubing, the thin inside liner is made of a chemically resistant material such as poly-olefin and ptfe that forms a barrier for the rest of the tubing wall from coming in contact with the pumped fluid. these liners are materials that are often not elastomeric, therefore the entire tube wall cannot be made wit...
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dd59da76c7587a59f74f30486cec2e9d5c323cb9
the tubing needs to be elastomeric to maintain
the tubing needs to be elastomeric to maintain the circular cross-section after millions of cycles of squeezing in the pump. this requirement eliminates a variety of non-elastomeric polymers that have compatibility with a wide range of chemicals, such as ptfe, polyolefins, pvdf, etc. from consideration as material for ...
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ed0abfa439db336f440cfd6cfbd93ca19a8d3842
the pumped fluid contacts only the inside surface
the pumped fluid contacts only the inside surface of the tubing. this eliminates fluid compatibility concerns with other pump components such as valves, o-rings, and seals, which must be considered for other pump designs. therefore, only the composition of the tubing that the pumped medium travels through is considered...
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e75aa6fda4baf2afe889ac083895466e4ee18482
the ideal peristaltic pump should have an infinite
the ideal peristaltic pump should have an infinite diameter of the pump head and the largest possible diameter of the rollers. such an ideal peristaltic pump would offer the longest possible tubing lifetime and provide a constant and pulsation-free flow rate.
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f81c189325748c91975dcebf0826abd08f2823d5
peristaltic pumps are typically used to pump clean/sterile
peristaltic pumps are typically used to pump clean/sterile or highly reactive fluids without exposing those fluids to contamination from exposed pump components. some common applications include pumping iv fluids through an infusion device, apheresis, highly reactive chemicals, high-solids slurries, and other materials...
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c4971a8066608e98833aa030fb252fc6a0f21ac0
a form of peristaltic pump was described in
a form of peristaltic pump was described in the mechanics magazine in 1845. the pump used a leather hose which did not need to self-open when released by the rollers, instead relying on the incoming water having sufficient pressure to fill the open inlet end on each cycle. the peristaltic pump was first patented in the...
wikipedia
86547036480e64a23c934b471c3d689a45ef71a7
a peristaltic pump, also commonly known as a
a peristaltic pump, also commonly known as a roller pump, is a type of positive displacement pump used for pumping a variety of fluids. the fluid is contained in a flexible tube fitted inside a circular pump casing. most peristaltic pumps work through rotary motion, though linear peristaltic pumps have also been made. ...
wikipedia
a13f75d9e6dc465bd5cb51ca96066c8831b0bef0
grady w. lewis was an american professional basketball
grady w. lewis was an american professional basketball player. he played college basketball for the southwestern oklahoma state bulldogs and oklahoma sooners. lewis played four seasons with the phillips 66 oilers of the aau, and three seasons (1946–1949) in the basketball association of america as a member of the detro...
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787f87dfb44adc107275e611d2969c5812d40aed
lewis coached the st. louis bombers during the
lewis coached the st. louis bombers during the 1948–49 and 1949–50 seasons. he then worked for the converse shoe company. lewis went on to invent the converse all stars shoe, although he did not get recognition as the famous marketer chuck taylor was accredited due to his popular name. lewis was inducted into the south...
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