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Evidence of photoreduction of chlorophyll in vivo
Solar Abstracts Conl innation of a st udy by (!oleman involving t he nleasure ln(,in of the difference SlleC! rmn of ilhnnin:tted ('hlorelht cells up t o 720 ilhmlinat ions.
Arnold, William; Sherwood, Helen, "Energy storage in chlor()pl.lsts." J. Ph:/s. Chem. 6 3 ( 1 ) : 2 4, J a n . 1!)5!). Illus.
•
])ried chlor(ipl:tst fihns thai have been ilhlminated exhibit tl~ermohlminescence. Tile glow curves h.tve been analyzed to give the aclivation energies associated with this energy stor age. The analysis shows that at least five different activalion energies are involved: one at 0.93 ev represents a little less than half of the stored energy; another at 0.69 ev is a minor p,lrt; |tel ween lhese two there are two or three unsolved levels that represent the major fraction; finally, unilluminated sampies :tlways give It small signal corresponding to an 'tctiv:tlion energy higher than 0.93 ev. (:ntthors' 'ibstr'tct)
D u b o i s , .le:m T., " T h e s e n s i t i z e d fluorescellce~ of 3 - n a p h l h y l ' u n i n e ; a s t u d y in t r a n s f e r of e l e c t r o n i c e n e r g y . " J. Phgs. Chem. 6 3 ( I ) : 8 - 1 1 , ,I'm. 1,,)r.() o,. Illus. The g'ts sensitized fluorescence of f~-naphthyl:mfine was studied at 150 ° using benzene as l)ho~osensitizer. Amine pressures of 0.53 and 1.25 mm were used. A kinetic mech:mism for the transfer of eleclronic energy is proposed. (author's :all sl
B(Iw(m, E . . l . ; S a h u , ,l., " T h e effect of t e m p e r a t u r e on ftuor(,sc('n('e of s o l u t i ( i , s . " ,I. Ph!/s. Chem. 6 3 ( 1 ) : 4 7, J a n . 1959. Illus.
r'le| ) $
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Duffle, J o h n A. ; Lof, G. (). (;. ; S a l a m , E h a b , " D e v e l o p m e n t s in solar e n e r g y h e a t e x c h a n g e r s . " l ) a p e r p r e s e n t e d •~t t h e S a l t L a k e ( ; i t y m e e t i n g of t h e A m e r i can I n s t i t u t e of C h e m i c a l E n g i n e e r s , S e p t . 1958. 30 p. Illus.
grain with solar heated air." Quart. Bull. 3Itch. A(/rie. E.rp. Sla. 4 1 ( 2 ) : 4 2 1 - 2 9 , N o v . 1!)58. Illus. •
~
1)iscusses lhe possibility of reducing grain and hay drying c(,sts on farms bv using solar energy for heating the air which is used in tile drying process. Energy storage would nol lie needed because when solar energy is not available, unheated "fir (.an be used to prevent the spoilage of grain and h.ty. Various types of air he.tters for grain drying systems discussed in lilts pal)er wore tested exl)erimentnlly. $
$
$
l~uelow, 1". II., " D r y i n g
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*
The prolmble economic feasibility of several solar applications is assessed by using the costs of energy from present sources as a basis for estimating upper limits on the first cost of solar heat exchangers and their associated equipment. 1.2cononlie considerations have helped shape tile deveh)pment ~t' the Wisconsin solar energy progr.tm, which includes studies of sohlr heat exchangers "rod their applications to heating, ('o,tling, :tilt[ p o w e r generation. (HllthoFs' : d i s t r a c t ) ¢s
$
$
l)uffie, J o h n A. ; Lof, G. (). G., " S o l a r e n e r g y ; e c o n o m i c s a n d e n g i n e e r i n g r e s e a r c h at t h e I ; n i v e r s i t y of W i s c o n s i n . " Canadian J. ('hem. En(/r. Apr. 1(.)50: 7 7 - 8 4 . Illus.
MeIisltrements h.Lve I)een made of the effect of lemper,tture on the fluorescence yiehts of substituied anthr.~cenes dissolved in several solvents, q-substituted anthracenes show high yiehts •~nd stee l) l emper.~ture dependencies, while side substituted derivatives have low yields and small temperature v.~riations. The results are interl)'reted in terms of the following coneepls. There appear to he two t)rocesses of energy degradation of the exciled molecules, a sut>stantially temperature independent one which is probably associated with the singlet-triplet conversion, "~nd a temt)erature dependent one having "~ he:tl of a(qivation of degr.tdation and a del)endence on solvent visc(,si~y which nuty be associated with a direct transition fronl ex<,ited 1() the ground slale. (:,ulhors' abslract) $
:4:
R.esults of recent studies on methods for improving sohtr heat exchanger performance and reducing costs are presented, including the use of semitransparent coatings on absorller surface Io reduce long-wave radiation losses while retaining high :dlsorptivily for short-wave solar radiation. Recent improvelllell|S in refit,cleF construction, el)Ileal loss reduction, and tr~lnSl)'lF(~lll
¢s
c o v e r s for s o l a r h e a l e x c h a n g e s u r f a c e s life ltlso
discussed. (a/it hers' abstract)
But,low, t:. hi.; B o y d , J. S., " H e a t i n g air b y s o l a r e l l e r g y . " Agric. Eng. 3 8 ( 1 ) : 2 8 - 3 0 , J a n . 1957. Illus. E g g e r t , .1., "'The i g n i t i o u of e x p h ) s i v e s b y r a d i : t t i o n . " .I. Pb!ls. ('hem. 6 3 ( 1 ) : 11 15, J a n . l.q5!). Illus.
l)escribes lhe e(mst ruction and operating ch'~racleristics of an :lir-he:~ling solar collector designed by the autimrs and dis cusses the possibilities of using it: in a solltr heating systcnl on
hi the experiments of Norrish and Porter the radiation which is emitled as very high energy within milliseconds by suitable electric discharges serves to dissociate gases, such as chh)rine, into aloms or radicals. In these cases the absorbed energy is consmned in making possible one or several chemical t)rocesses; 1he system reacts exehlsively with the .d)sorbed energy, even if it returns to llle original state afterwards. In this e.tse, ~he absorbed energy is stored as chemical energy; lh~, sysleln oper:ttes just as :t phnlt during photosynthesis.
fH FillS,
C o l e m a n , ,I. W . ; R a b i n o w i t c h , E u g e n e , " E v i d e n c e of p h o t l ) r e d u c t i o n of chlor()phyll in r i v e . " J. Phys. ('hem. 6 3 ( 1 ) : 30 34, J a n . 1959. Illus. 39
Arnold, William; Sherwood, Helen, "Energy storage in chlor()pl.lsts." J. Ph:/s. Chem. 6 3 ( 1 ) : 2 4, J a n . 1!)5!). Illus.
•
])ried chlor(ipl:tst fihns thai have been ilhlminated exhibit tl~ermohlminescence. Tile glow curves h.tve been analyzed to give the aclivation energies associated with this energy stor age. The analysis shows that at least five different activalion energies are involved: one at 0.93 ev represents a little less than half of the stored energy; another at 0.69 ev is a minor p,lrt; |tel ween lhese two there are two or three unsolved levels that represent the major fraction; finally, unilluminated sampies :tlways give It small signal corresponding to an 'tctiv:tlion energy higher than 0.93 ev. (:ntthors' 'ibstr'tct)
D u b o i s , .le:m T., " T h e s e n s i t i z e d fluorescellce~ of 3 - n a p h l h y l ' u n i n e ; a s t u d y in t r a n s f e r of e l e c t r o n i c e n e r g y . " J. Phgs. Chem. 6 3 ( I ) : 8 - 1 1 , ,I'm. 1,,)r.() o,. Illus. The g'ts sensitized fluorescence of f~-naphthyl:mfine was studied at 150 ° using benzene as l)ho~osensitizer. Amine pressures of 0.53 and 1.25 mm were used. A kinetic mech:mism for the transfer of eleclronic energy is proposed. (author's :all sl
B(Iw(m, E . . l . ; S a h u , ,l., " T h e effect of t e m p e r a t u r e on ftuor(,sc('n('e of s o l u t i ( i , s . " ,I. Ph!/s. Chem. 6 3 ( 1 ) : 4 7, J a n . 1959. Illus.
r'le| ) $
*
Duffle, J o h n A. ; Lof, G. (). (;. ; S a l a m , E h a b , " D e v e l o p m e n t s in solar e n e r g y h e a t e x c h a n g e r s . " l ) a p e r p r e s e n t e d •~t t h e S a l t L a k e ( ; i t y m e e t i n g of t h e A m e r i can I n s t i t u t e of C h e m i c a l E n g i n e e r s , S e p t . 1958. 30 p. Illus.
grain with solar heated air." Quart. Bull. 3Itch. A(/rie. E.rp. Sla. 4 1 ( 2 ) : 4 2 1 - 2 9 , N o v . 1!)58. Illus. •
~
1)iscusses lhe possibility of reducing grain and hay drying c(,sts on farms bv using solar energy for heating the air which is used in tile drying process. Energy storage would nol lie needed because when solar energy is not available, unheated "fir (.an be used to prevent the spoilage of grain and h.ty. Various types of air he.tters for grain drying systems discussed in lilts pal)er wore tested exl)erimentnlly. $
$
$
l~uelow, 1". II., " D r y i n g
*
*
The prolmble economic feasibility of several solar applications is assessed by using the costs of energy from present sources as a basis for estimating upper limits on the first cost of solar heat exchangers and their associated equipment. 1.2cononlie considerations have helped shape tile deveh)pment ~t' the Wisconsin solar energy progr.tm, which includes studies of sohlr heat exchangers "rod their applications to heating, ('o,tling, :tilt[ p o w e r generation. (HllthoFs' : d i s t r a c t ) ¢s
$
$
l)uffie, J o h n A. ; Lof, G. (). G., " S o l a r e n e r g y ; e c o n o m i c s a n d e n g i n e e r i n g r e s e a r c h at t h e I ; n i v e r s i t y of W i s c o n s i n . " Canadian J. ('hem. En(/r. Apr. 1(.)50: 7 7 - 8 4 . Illus.
MeIisltrements h.Lve I)een made of the effect of lemper,tture on the fluorescence yiehts of substituied anthr.~cenes dissolved in several solvents, q-substituted anthracenes show high yiehts •~nd stee l) l emper.~ture dependencies, while side substituted derivatives have low yields and small temperature v.~riations. The results are interl)'reted in terms of the following coneepls. There appear to he two t)rocesses of energy degradation of the exciled molecules, a sut>stantially temperature independent one which is probably associated with the singlet-triplet conversion, "~nd a temt)erature dependent one having "~ he:tl of a(qivation of degr.tdation and a del)endence on solvent visc(,si~y which nuty be associated with a direct transition fronl ex<,ited 1() the ground slale. (:,ulhors' abslract) $
:4:
R.esults of recent studies on methods for improving sohtr heat exchanger performance and reducing costs are presented, including the use of semitransparent coatings on absorller surface Io reduce long-wave radiation losses while retaining high :dlsorptivily for short-wave solar radiation. Recent improvelllell|S in refit,cleF construction, el)Ileal loss reduction, and tr~lnSl)'lF(~lll
¢s
c o v e r s for s o l a r h e a l e x c h a n g e s u r f a c e s life ltlso
discussed. (a/it hers' abstract)
But,low, t:. hi.; B o y d , J. S., " H e a t i n g air b y s o l a r e l l e r g y . " Agric. Eng. 3 8 ( 1 ) : 2 8 - 3 0 , J a n . 1957. Illus. E g g e r t , .1., "'The i g n i t i o u of e x p h ) s i v e s b y r a d i : t t i o n . " .I. Pb!ls. ('hem. 6 3 ( 1 ) : 11 15, J a n . l.q5!). Illus.
l)escribes lhe e(mst ruction and operating ch'~racleristics of an :lir-he:~ling solar collector designed by the autimrs and dis cusses the possibilities of using it: in a solltr heating systcnl on
hi the experiments of Norrish and Porter the radiation which is emitled as very high energy within milliseconds by suitable electric discharges serves to dissociate gases, such as chh)rine, into aloms or radicals. In these cases the absorbed energy is consmned in making possible one or several chemical t)rocesses; 1he system reacts exehlsively with the .d)sorbed energy, even if it returns to llle original state afterwards. In this e.tse, ~he absorbed energy is stored as chemical energy; lh~, sysleln oper:ttes just as :t phnlt during photosynthesis.
fH FillS,
C o l e m a n , ,I. W . ; R a b i n o w i t c h , E u g e n e , " E v i d e n c e of p h o t l ) r e d u c t i o n of chlor()phyll in r i v e . " J. Phys. ('hem. 6 3 ( 1 ) : 30 34, J a n . 1959. Illus. 39