Eichenberger, Rudolph J.

English

UARK (University of Arkansas )

Journal of the Arkansas Academy of Science Volume 37 Article 27 1983 Flat Plate Solar Thermal Collectors: A Comparison of Efficiencies of Various Collector Configurations Rudolph J. Eichenberger Southern Arkansas University Follow this and additional works at: https://scholarworks.uark.edu/jaas  Part of the Engineering Physics Commons Recommended Citation Eichenberger, Rudolph J. (1983) "Flat Plate Solar Thermal Collectors: A Comparison of Efficiencies of Various Collector Configurations," Journal of the Arkansas Academy of Science: Vol. 37 , Article 27. Available at: https://scholarworks.uark.edu/jaas/vol37/iss1/27 This article is available for use under the Creative Commons license: Attribution-NoDerivatives 4.0 International (CC BY-ND 4.0). Users are able to read, download, copy, print, distribute, search, link to the full texts of these articles, or use them for any other lawful purpose, without asking prior permission from the publisher or the author. This General Note is brought to you for free and open access by ScholarWorks@UARK. It has been accepted for inclusion in Journal of the Arkansas Academy of Science by an authorized editor of ScholarWorks@UARK. For more information, please contact scholar@uark.edu. I82Arkansas Academy of Science Proceedings, Vol. XXXVII,1983Arkansas Academy of ScienceAchaearanea and Prolinyphia species are web builders that were found hanging in their webs at the top and along the walls of the tunnelapparently tryingto trap small flying insects. Specimens ofAchaearanea porteri (Banks) collected during this study represent the onlyknown localitiesfor this spider from the Ouachita Mountain area and only the second collection of this species in the state. Interestingly, the only other reportof this spider from Arkansas was by Barnett (1970) who found this species utilizing similar habitat within Mansell Cave inRandolph countyMembers of the genus Amaurobius were found primarilyunder stones and inrock fissures or wall crevices. Dark areas ofthe tunnels nearthe entrances were preferred. Specimens ofAmaurobius ferox (Walckenaer) collected during this study represent anew state record.Assistance from Darrell Heath and Teresa Beggs in collecting specimens is gratefully acknowledged.Table. Data concerning spider collections from mine tunnels. LITERATURE CITEDDistance inMetersTaxon Date County From EntranceknauKobwl rfeAox (Walck.) 12/20/82 Garland 0-8Volomtda vlttatui (Walck.) 1/08/83 Polk 0-8AchaeaAanta po/UvU (Banks) 1/18/83 Garland 0-8hmu/wbuiJ, idAox (Walck.) 2/20/83 Garland 17-50Pnotuiyptua maAginata (Koch) 2/20/83 Garland 0-8Adiawuuiea potttAi (Banks) 2/20/83 Garland 0-8Achaeawnea te.pidaAA.o'wm (Koch) 2/20/83 Garland 0-8KdnoMVWLnta tzpldaAxomm (Koch) 2/20/83 Montgomery 0-8Votcmniu ulttatui (Walck.) 2/20/83 Montgomery 0-20Amautob.ua ieAox (Walck.) 2/20/83 Montgomery 0-50Dotomzdu vlttatui (Walck.) 2/12/83 Polk 0-50Volomzde* \i-Utaiu6 (Walck.) 2/12/83 Polk 0-50Votomzda ttmbKoiui (Hentz) 3/26/83 Polk 0-10Votomadej, viXXaXiiA (Walck.) 3/26/83 Polk 0-10AmauJwbiui, tfeAox (Walck.) 3/26/83 Polk 0-10BARNETT,D. E. 1970. An ecological investigation of cavernicolepopulations inMansell Cave, Randolph county, Arkansas. M.S.Thesis. Northwestern State Univ.,LA. 51 pp.DUNIVAN,J. D.,C.R. TUMLISON,and V.R. MCDANIEL.1982Cave fauna ofArkansas: further records. Proc. Ark. Acad. Sci36:87-88.GROVE, J. L. 1974. Ecology of Blanchard Springs Caverns. OzarkNational Forest, Arkansas. M.S. Thesis. Memphis State Univ. TN27 pp.HUBRICHT, L. 1950. The invertebrate fauna ofOzark caves. Bull.Nat. Speleol. Soc. 12:16-17.MCDANIEL,V. R., K. N. PAIGE, and C. R. TUMLISON. 1979.Cave fauna of Arkansas: additional invertebrate and vertebraterecords. Proc. Ark. Acad. Sci. 33:84-85.MCDANIEL, V. R., and K. L. SMITH. 1976. Cave fauna ofArkansas: selected invertebrate taxa. Proc. Ark. Acad. Sci.PEGGY R. DORRIS, Department ofBiology,Henderson State University, Arkadelphia, AR 71923, and DA VIDA.SAUGEY, UnitedStates ForestService, Hot Springs, AR 71901.FLAT PLATE SOLAR THERMAL COLLECTORS: A COMPARISON OFEFFICIENCIES OF VARIOUS COLLECTOR CONFIGURATIONSIn a previous study, collectors were installed vertically in a south-facing single glazed laboratory window. The dual functions were as athermal solar collector and as an insulator for the window. Results included an energy saving from the insulation property ofapproximately 19dollars per year and an experimental solar energy collection income of approximately 2 dollars per year (Eichenberger, Energy Conv. &Mgt.,20:197-199, 1980).The purpose ofthis study was to compare the efficiencies, energy collected, and construction cost for various practical collector configura-tions and materials.The inside configuration and materials used in converting solar radiation to heat energy were varied for comparison. Cover plate materialswere also varied for comparison. Materials tested were relatively inexpensive building materials suitable forself-construction and installation. Thematerial cost per thermal power delivered (watt) was also calculated since this is an important consideration insolar utilization.Twosolar collectors were constructed toprovide a side-by-side test situation. The collectors were both 1.22 meter by 1.22 meter outside dimensions.One collector served as the control and the other as the experimental model on which the internal material and cover plates were changed. Solarinsolation was measured with a meter which was calibrated using a reference source on the same date and time and extrapolated for the samelatitude (Anderson, Solar energy; fundamentals inbuildingdesign, p. 292, 1977). Each collector was fitted with an electric blower rated at 16 wattsand 0.99 cubic meter per minute of free air; it delivered ameasured 0.42 cubic meter per minute ofair flow when connected to the collector. Theflowrate ofthe blower was measured withaDwyer flow meter. This measured rate was compared withamechanical anemometer and a fan. Resultsofthe two flow rate measurements were with5<7o. Ambient temperatures and output air temperatures were measured. Heat delivered was calculatedand the input solar energy was measured with the meter and used in calculating the efficiencies.Inthe first stage of the experiment, both collectors were fitted withidentical double glaze polycarbonate covers. The inside absorber con-figurations were changed for comparison of efficiencies and thermal power produced. The control collector had aluminum screen placed 2.5centimeters above a styrofoam insulation board in the back. Both the aluminum screen and the insulation board were painted flat black withinexpensive carbon and silicate-based paint. Airwas forced from the back through the screen toward the cover plate, and then pulledback throughthe screen absorber bya fan and abaffle and out the back (see Fig.1).The experimental collector was also fitted with a2.5 centimeter thick styrofoaminsulation panel covering the back. Then 2.5 centimeter high styrofoam channels were attached to the insulation board. These channels weredesigned to produce a serpentine air flow across the collector (see Fig. 2). The entire board and channels were covered with aluminum foiland82Journal of the Arkansas Academy of Science, Vol. 37 [1983], Art. 27Published by Arkansas Academy of Science, 1983Arkansas Academy of Science Proceedings, Vol. XXXVII,1983 83General NotesSingle Glaze Filoi 26* 172 watts + 5 watts(Fiberglass Reinforced Resin)Figure 1.Table 1. Interior Light to Heat Conversion Materials with IdenticalDouble Glaze Polycarbonate CoversHaterlal Average Efficiency Average Thermal Power/m2Black Aluminum Screen* 35* 237 watts + 5 wattsBlack Aluminum Foil Channeled 32* 205 watts + 5 watt!Black Aluminum Screen* 35* 194 watts ? 5 wattsBlack Steel Roofing 24* 129 watts *_ 5 watts*Indicates control collector unit operating during the same time period.Table 2. Various Cover Plates with Identical Interior Black AluminumScreen AbsorbersMaterial Average Efficiency Average Thermal Power/m2Double Glaze Polycarbonate* 37* 237 watt + 5 wattsSingle Glaze Styrene Acrylonitr ile 29* 183 watts *_ 5 wattsDouble Glaze Polycarbonate* 37* I94 watts ? 5 wattsTable 3.Black Aluminum Screen Absorber- 2I4 /w.>1tBlack Steel Roofing Absorber- 36</wattDouble Glaze Polycarbonate CoverBlack Aluminum Foil Channeled Absorber- 2U/wattDouble Glaze Polycarbonate CoverSingle Glaze Styrene Acrylonitrlle- I8c/wattBlack Aluminum Screen AbsorberSingle Glaze Filon- I5c/wattBlack Aluminum Screen Absorbertted flatblack. The second experimental configuration was assembled with corrugated steel roofing painted flat black as the absorber plate,was made to flow over the top of the roofing and below the roofing and between the styrofoam insulation board.second part ofthe experiment compared different materials commonly available as cover plates withidentical flat black aluminum screenrbers as described earlier.tAmaterials cost analysis was done foreach collector configuration to find the cost per unit ofthermal power delivered. The analysis excludedcosts. The results are displayed in Table 3.Flat black aluminum screen absorber delivered the highest conversion from solar lighttoheat efficiency ofabout 35% and the highest averagethermal power of about 240 watt/m 2. Double glazed polycarbonate was the most efficient cover plate, as expected, and delivered the highestthermal power. Of the single glazed material tested, styrene acrylonitrile delivered slightly higher efficiency and thermal rating. Collector efficien-cies were higher on lower ambient temperature days, as one would expect, because ofradiation energy losses from the collector proportional tothe fourthpower of the absolute temperature and lower collector temperatures on those days. Results were averaged over aminimum offive daysto reduce these variations, and values reported in Tables 1 and 2 compared experimental with control units during the same time period.materials cost per delivered unit of thermal power was lowest for the single glazed filoncover plate at about 15t/watt with the blackinum screen absorber material.83Journal of the Arkansas Academy of Science, Vol. 37 [1983], Art. 27https://scholarworks.uark.edu/jaas/vol37/iss1/27Arkansas Academy of Science Proceedings, Vol. XXXVII,198384Arkansas Academy of ScienceFurther study is planned using polyethylene filmas one glazing and a rigidmaterial such as filonas the second glazing to cutcosts and increasethe effectiveness, therefore promoting the utilization of solar energy.RUDOLPH J. EICHENBERGER, Physics-Engineering Dept., Southern Arkansas University, Magnolia, AR 71753.NEUTRAL SUGARS INSELECTED PIT VIPER, ELAPID,LIZARDAND SCORPION VENOMSCarbohydrates exist in venoms in the form ofglycoproteins and as free sugars. Aragon et al. (1977) reported that venom from the CentralAmerican Bothrops asper is very rich inboth glycoproteins and free sugars. Glycoproteins are reported in a wide variety ofsnake venoms (Oshimaand Iwanaga, 1969; Basu et al., 1970; Hatton, 1973; Ruff et al., 1980; Marias, 1982). Viperid and crotalid venoms often contain relatively largeamounts of bound carbohydrates when compared with venoms of elapids. These carbohydrates include neutral sugars, amino sugars, and sialkacid (Oshima and Iwanaga, 1967). In this paper we quantitatively compare L-fucose, D-galactose, D-glucose, and D-mannose neutral sugars ofwhole venoms from snakes, lizards, and scorpions. The venoms were also analyzed for the presence of D-arabinose and D-xylose.L-fucose and lyophilizedvenoms ofAgkistrodon bilineatus, Heloderma horridum, H. suspectum, Androctonus australis, and Naja naja atrawere purchased from Sigma Chemical Company. The other venoms, also lyophilized, were a gift from Dr. H.L.Stahnke of the Poisonous AnimalsResearch Laboratory at Arizona State University. The other carbohydrate standards were purchased from Chem Service, Inc.;l-dimethylamino-2-propanol from Aldrich Chemical Company; methanol from MCB Manufacturing Chemists, Inc.; and pyridine from FisherScientific Company. All liquidreagents were redistilled prior to use.Gas chromatography was performed using a Perkin-Elmer Model 3920B instrument equipped with dual flame ionization detectors and 6-ft.,l/8-in.-o.d. nickel columns packed with1% stabilized diethylene glycoladipate on 100-200 mesh Chromosorb W (HP) by the procedure describedby Mawhinney et al. (1980). Data were collected, stored, and analyzed by a Varian Vista 401 Chromatography Data System.Neutral sugars were obtained by heating 2 to 4mg samples of venom with 1.0 mlof0.6 NHC1 per mg ofvenom at 100°for 4h and elutingin sequence through 0.8 x 8-cm columns of Dowex 1-4X (CO," form, 50-100 mesh) and Dowex 5O-8X (H+form, 200-400 mesh) with distilledH2O. One ml ofinternal standard solution containing 0.0186 mg ofphenyl /3-D-glucopyranoside was added to the effluent before the sample wasconcentrated bylyophilization. To convert neutral sugars to oximes, the effluent was mixed with 0.2 ml ofa solution containing 0.6 g of hydrox-ylamine hydrochloride, 2.0 ml of methanol, 5.47 ml of pyridine, and 0.53 ml of l-dimethylamino-2-propanol and heated at 70° for 5 min in aTeflon-capped Reacti-vial. Aftercooling toroom temperature, a stream ofdryair was directed into the open vial toremove excess reagent. Acetatederivatives were prepared by adding 1.0 ml of pyridine-acetic anhydride (1:3 v/v), mixing, and heating the vial at 70° for 25 min. The vial wascooled to room temperature, after which the solution was reduced to a syrup using a stream ofdryair.To remove salts, the contents were dissolvedin 1.0ml ofchloroform and washed once with 1.0 ml of1.0 NHC1and three times with 1.0 ml each ofdistilled water. The chloroform was evaporatedwith a stream of dry air (Mawhinney et al., 1980). For conversion to aldononitrile acetate (Varmer, et al., 1973), 0.6 ml of pyridine and 1.8 mlof acetic anhydride were added and the mixture was heated at 90° for 30 min. The solution was evaporated to dryness at 40° under diminishedpressure with a stream of nitrogen directed into the vessel.Neutral sugars are present in pitviper, elapid, lizard, and scorpion venoms (Table). D-arabinose and D-xylose were not detected in venomsofCrotalus molossus, C. scutulatus, and N.naja. Only trace amounts, less than 1 figper mg ofvenom, of these sugars were indicated in the othervenom analyses. Venom ofA.piscivorus piscivorus was relatively low inD-mannose. Otherwise, pit viper venoms contained abundant D-mannose,comparable amounts of L-fucose and D-galactose, and relatively small amounts of D-glucose. A. bilineatus venom was highest in all the sugarsassayed, except D-glucose. D-mannose was not the major sugar inthe elapid venom tested; however, D-mannose was dominant inthe lizard venom.Centruroides sculpturatus venom was higher in total neutral sugar than the other scorpion venoms.A significant unidentified peak (Fig.), probably indicating another neutral sugar, was recorded immediately prior to the D-mannose peakin the chromatograms of A.p. piscivorus, C. arrox, N. naja, and N. n. atra venom samples. This peak was minor or absent in the remainingchromatograms. Small unidentified peaks were also recorded immediately prior to the L-fucose peak.Sialic acid and amino sugar analyses of the above venoms are now inprogress.Table. Neutral Sugars in Various Venoms'*Vm« L-fuc P-««J °-«l"°-""Pit Vipers:A»kl»trodon blllnMtm 13.3 9.8 1.2 15.4Anklttrodon pl.clvonT pl.clvorUT 3.5 1.2 1.3 1.0Crot.lu. »tro» 3.0 2.7 1.9 5.6Crot.lu. molu..u. 2.0 2.1 1I1CI 3.0Crotilu. .cutul.tu. 2.5 6.0 tr.ce 8.3Crot.lu. 7lrldl. cerb.ru. 2.2 4.8 1.5 6.0mm^ » « a"Llxarda:H«iod«r»* horrldua 2.3 6.3 2.6 7.2H«lod«rma .u.pecty 2.0 4.5 trace 5.1Scorpion*:AndroctomiB auatralla 1.3 1.0 2.4 1.4Centruroldea aculptur»tu« 5.9 6.2 4.6 4.6Hadrurm "aTTxonmala 1.8 1.4 1.3 3.6Hjidruru. TTlrautua 1.4 4.4 1.4 4.0*ug of augar/ag of venon+ trace Indlcataa < 1.0 pg of augar/ng of venomvenom as aldononitrile acetates. The initial hold was at 170° for twominutes followed by an increase of 8°/min to a final temperature ot240°. Nitrogen flow rate was 24 ml/min and sample size was 4 pi.84Journal of the Arkansas Academy of Science, Vol. 37 [1983], Art. 27Published by Arkansas Academy of Science, 1983

Flat Plate Solar Thermal Collectors: A Comparison of Efficiencies of Various Collector Configurations

ScholarWorks@UARK

Journal of the Arkansas Academy of ScienceVolume 37 Article 271983Flat Plate Solar Thermal Collectors: A Comparisonof Efficiencies of Various Collector ConfigurationsRudolph J. EichenbergerSouthern Arkansas UniversityFollow this and additional works at: http://scholarworks.uark.edu/jaasPart of the Engineering Physics CommonsThis article is available for use under the Creative Commons license: Attribution-NoDerivatives 4.0 International (CC BY-ND 4.0). Users are able toread, download, copy, print, distribute, search, link to the full texts of these articles, or use them for any other lawful purpose, without asking priorpermission from the publisher or the author.This General Note is brought to you for free and open access by ScholarWorks@UARK. It has been accepted for inclusion in Journal of the ArkansasAcademy of Science by an authorized editor of ScholarWorks@UARK. For more information, please contact scholar@uark.edu, ccmiddle@uark.edu.Recommended CitationEichenberger, Rudolph J. (1983) "Flat Plate Solar Thermal Collectors: A Comparison of Efficiencies of Various CollectorConfigurations," Journal of the Arkansas Academy of Science: Vol. 37 , Article 27.Available at: http://scholarworks.uark.edu/jaas/vol37/iss1/27I82Arkansas Academy of Science Proceedings, Vol. XXXVII,1983Arkansas Academy of ScienceAchaearanea and Prolinyphia species are web builders that were found hanging in their webs at the top and along the walls of the tunnelapparently tryingto trap small flying insects. Specimens ofAchaearanea porteri (Banks) collected during this study represent the onlyknown localitiesfor this spider from the Ouachita Mountain area and only the second collection of this species in the state. Interestingly, the only other reportof this spider from Arkansas was by Barnett (1970) who found this species utilizing similar habitat within Mansell Cave inRandolph countyMembers of the genus Amaurobius were found primarilyunder stones and inrock fissures or wall crevices. Dark areas ofthe tunnels nearthe entrances were preferred. Specimens ofAmaurobius ferox (Walckenaer) collected during this study represent anew state record.Assistance from Darrell Heath and Teresa Beggs in collecting specimens is gratefully acknowledged.Table. Data concerning spider collections from mine tunnels. LITERATURE CITEDDistance inMetersTaxon Date County From EntranceknauKobwl rfeAox (Walck.) 12/20/82 Garland 0-8Volomtda vlttatui (Walck.) 1/08/83 Polk 0-8AchaeaAanta po/UvU (Banks) 1/18/83 Garland 0-8hmu/wbuiJ, idAox (Walck.) 2/20/83 Garland 17-50Pnotuiyptua maAginata (Koch) 2/20/83 Garland 0-8Adiawuuiea potttAi (Banks) 2/20/83 Garland 0-8Achaeawnea te.pidaAA.o'wm (Koch) 2/20/83 Garland 0-8KdnoMVWLnta tzpldaAxomm (Koch) 2/20/83 Montgomery 0-8Votcmniu ulttatui (Walck.) 2/20/83 Montgomery 0-20Amautob.ua ieAox (Walck.) 2/20/83 Montgomery 0-50Dotomzdu vlttatui (Walck.) 2/12/83 Polk 0-50Volomzde* \i-Utaiu6 (Walck.) 2/12/83 Polk 0-50Votomzda ttmbKoiui (Hentz) 3/26/83 Polk 0-10Votomadej, viXXaXiiA (Walck.) 3/26/83 Polk 0-10AmauJwbiui, tfeAox (Walck.) 3/26/83 Polk 0-10BARNETT,D. E. 1970. An ecological investigation of cavernicolepopulations inMansell Cave, Randolph county, Arkansas. M.S.Thesis. Northwestern State Univ.,LA. 51 pp.DUNIVAN,J. D.,C.R. TUMLISON,and V.R. MCDANIEL.1982Cave fauna ofArkansas: further records. Proc. Ark. Acad. Sci36:87-88.GROVE, J. L. 1974. Ecology of Blanchard Springs Caverns. OzarkNational Forest, Arkansas. M.S. Thesis. Memphis State Univ. TN27 pp.HUBRICHT, L. 1950. The invertebrate fauna ofOzark caves. Bull.Nat. Speleol. Soc. 12:16-17.MCDANIEL,V. R., K. N. PAIGE, and C. R. TUMLISON. 1979.Cave fauna of Arkansas: additional invertebrate and vertebraterecords. Proc. Ark. Acad. Sci. 33:84-85.MCDANIEL, V. R., and K. L. SMITH. 1976. Cave fauna ofArkansas: selected invertebrate taxa. Proc. Ark. Acad. Sci.PEGGY R. DORRIS, Department ofBiology,Henderson State University, Arkadelphia, AR 71923, and DA VIDA.SAUGEY, UnitedStates ForestService, Hot Springs, AR 71901.FLAT PLATE SOLAR THERMAL COLLECTORS: A COMPARISON OFEFFICIENCIES OF VARIOUS COLLECTOR CONFIGURATIONSIn a previous study, collectors were installed vertically in a south-facing single glazed laboratory window. The dual functions were as athermal solar collector and as an insulator for the window. Results included an energy saving from the insulation property ofapproximately 19dollars per year and an experimental solar energy collection income of approximately 2 dollars per year (Eichenberger, Energy Conv. &Mgt.,20:197-199, 1980).The purpose ofthis study was to compare the efficiencies, energy collected, and construction cost for various practical collector configura-tions and materials.The inside configuration and materials used in converting solar radiation to heat energy were varied for comparison. Cover plate materialswere also varied for comparison. Materials tested were relatively inexpensive building materials suitable forself-construction and installation. Thematerial cost per thermal power delivered (watt) was also calculated since this is an important consideration insolar utilization.Twosolar collectors were constructed toprovide a side-by-side test situation. The collectors were both 1.22 meter by 1.22 meter outside dimensions.One collector served as the control and the other as the experimental model on which the internal material and cover plates were changed. Solarinsolation was measured with a meter which was calibrated using a reference source on the same date and time and extrapolated for the samelatitude (Anderson, Solar energy; fundamentals inbuildingdesign, p. 292, 1977). Each collector was fitted with an electric blower rated at 16 wattsand 0.99 cubic meter per minute of free air; it delivered ameasured 0.42 cubic meter per minute ofair flow when connected to the collector. Theflowrate ofthe blower was measured withaDwyer flow meter. This measured rate was compared withamechanical anemometer and a fan. Resultsofthe two flow rate measurements were with5<7o. Ambient temperatures and output air temperatures were measured. Heat delivered was calculatedand the input solar energy was measured with the meter and used in calculating the efficiencies.Inthe first stage of the experiment, both collectors were fitted withidentical double glaze polycarbonate covers. The inside absorber con-figurations were changed for comparison of efficiencies and thermal power produced. The control collector had aluminum screen placed 2.5centimeters above a styrofoam insulation board in the back. Both the aluminum screen and the insulation board were painted flat black withinexpensive carbon and silicate-based paint. Airwas forced from the back through the screen toward the cover plate, and then pulledback throughthe screen absorber bya fan and abaffle and out the back (see Fig.1).The experimental collector was also fitted with a2.5 centimeter thick styrofoaminsulation panel covering the back. Then 2.5 centimeter high styrofoam channels were attached to the insulation board. These channels weredesigned to produce a serpentine air flow across the collector (see Fig. 2). The entire board and channels were covered with aluminum foiland82Journal of the Arkansas Academy of Science, Vol. 37 [1983], Art. 27Published by Arkansas Academy of Science, 1983Arkansas Academy of Science Proceedings, Vol. XXXVII,1983 83General NotesSingle Glaze Filoi 26* 172 watts + 5 watts(Fiberglass Reinforced Resin)Figure 1.Table 1. Interior Light to Heat Conversion Materials with IdenticalDouble Glaze Polycarbonate CoversHaterlal Average Efficiency Average Thermal Power/m2Black Aluminum Screen* 35* 237 watts + 5 wattsBlack Aluminum Foil Channeled 32* 205 watts + 5 watt!Black Aluminum Screen* 35* 194 watts ? 5 wattsBlack Steel Roofing 24* 129 watts *_ 5 watts* Indicates control collector unit operating during the same time period.Table 2. Various Cover Plates with Identical Interior Black AluminumScreen AbsorbersMaterial Average Efficiency Average Thermal Power/m2Double Glaze Polycarbonate* 37* 237 watt + 5 wattsSingle Glaze Styrene Acrylonitr ile 29* 183 watts *_ 5 wattsDouble Glaze Polycarbonate* 37* I94 watts ? 5 wattsTable 3.Black Aluminum Screen Absorber- 2I4 /w.>1tBlack Steel Roofing Absorber- 36</wattDouble Glaze Polycarbonate CoverBlack Aluminum Foil Channeled Absorber- 2U/wattDouble Glaze Polycarbonate CoverSingle Glaze Styrene Acrylonitrlle- I8c/wattBlack Aluminum Screen AbsorberSingle Glaze Filon- I5c/wattBlack Aluminum Screen Absorbertted flatblack. The second experimental configuration was assembled with corrugated steel roofing painted flat black as the absorber plate,was made to flow over the top of the roofing and below the roofing and between the styrofoam insulation board.second part ofthe experiment compared different materials commonly available as cover plates withidentical flat black aluminum screenrbers as described earlier.tAmaterials cost analysis was done foreach collector configuration to find the cost per unit ofthermal power delivered. The analysis excludedcosts. The results are displayed in Table 3.Flat black aluminum screen absorber delivered the highest conversion from solar lighttoheat efficiency ofabout 35% and the highest averagethermal power of about 240 watt/m 2. Double glazed polycarbonate was the most efficient cover plate, as expected, and delivered the highestthermal power. Of the single glazed material tested, styrene acrylonitrile delivered slightly higher efficiency and thermal rating. Collector efficien-cies were higher on lower ambient temperature days, as one would expect, because ofradiation energy losses from the collector proportional tothe fourthpower of the absolute temperature and lower collector temperatures on those days. Results were averaged over aminimum offive daysto reduce these variations, and values reported in Tables 1 and 2 compared experimental with control units during the same time period.materials cost per delivered unit of thermal power was lowest for the single glazed filoncover plate at about 15t/watt with the blackinum screen absorber material.83Journal of the Arkansas Academy of Science, Vol. 37 [1983], Art. 27http://scholarworks.uark.edu/jaas/vol37/iss1/27Arkansas Academy of Science Proceedings, Vol. XXXVII,198384Arkansas Academy of ScienceFurther study is planned using polyethylene filmas one glazing and a rigidmaterial such as filonas the second glazing to cutcosts and increasethe effectiveness, therefore promoting the utilization of solar energy.RUDOLPH J. EICHENBERGER, Physics-Engineering Dept., Southern Arkansas University, Magnolia, AR 71753.NEUTRAL SUGARS INSELECTED PIT VIPER, ELAPID,LIZARDAND SCORPION VENOMSCarbohydrates exist in venoms in the form ofglycoproteins and as free sugars. Aragon et al. (1977) reported that venom from the CentralAmerican Bothrops asper is very rich inboth glycoproteins and free sugars. Glycoproteins are reported in a wide variety ofsnake venoms (Oshimaand Iwanaga, 1969; Basu et al., 1970; Hatton, 1973; Ruff et al., 1980; Marias, 1982). Viperid and crotalid venoms often contain relatively largeamounts of bound carbohydrates when compared with venoms of elapids. These carbohydrates include neutral sugars, amino sugars, and sialkacid (Oshima and Iwanaga, 1967). In this paper we quantitatively compare L-fucose, D-galactose, D-glucose, and D-mannose neutral sugars ofwhole venoms from snakes, lizards, and scorpions. The venoms were also analyzed for the presence of D-arabinose and D-xylose.L-fucose and lyophilizedvenoms ofAgkistrodon bilineatus, Heloderma horridum, H. suspectum, Androctonus australis, and Naja naja atrawere purchased from Sigma Chemical Company. The other venoms, also lyophilized, were a gift from Dr. H.L.Stahnke of the Poisonous AnimalsResearch Laboratory at Arizona State University. The other carbohydrate standards were purchased from Chem Service, Inc.;l-dimethylamino-2-propanol from Aldrich Chemical Company; methanol from MCB Manufacturing Chemists, Inc.; and pyridine from FisherScientific Company. All liquidreagents were redistilled prior to use.Gas chromatography was performed using a Perkin-Elmer Model 3920B instrument equipped with dual flame ionization detectors and 6-ft.,l/8-in.-o.d. nickel columns packed with1% stabilized diethylene glycoladipate on 100-200 mesh Chromosorb W (HP) by the procedure describedby Mawhinney et al. (1980). Data were collected, stored, and analyzed by a Varian Vista 401 Chromatography Data System.Neutral sugars were obtained by heating 2 to 4mg samples of venom with 1.0 mlof0.6 NHC1 per mg ofvenom at 100° for 4h and elutingin sequence through 0.8 x 8-cm columns of Dowex 1-4X (CO," form, 50-100 mesh) and Dowex 5O-8X (H+ form, 200-400 mesh) with distilledH2O. One ml ofinternal standard solution containing 0.0186 mg ofphenyl /3-D-glucopyranoside was added to the effluent before the sample wasconcentrated bylyophilization. To convert neutral sugars to oximes, the effluent was mixed with 0.2 ml ofa solution containing 0.6 g of hydrox-ylamine hydrochloride, 2.0 ml of methanol, 5.47 ml of pyridine, and 0.53 ml of l-dimethylamino-2-propanol and heated at 70° for 5 min in aTeflon-capped Reacti-vial. Aftercooling toroom temperature, a stream ofdryair was directed into the open vial toremove excess reagent. Acetatederivatives were prepared by adding 1.0 ml of pyridine-acetic anhydride (1:3 v/v), mixing, and heating the vial at 70° for 25 min. The vial wascooled to room temperature, after which the solution was reduced to a syrup using a stream ofdryair.To remove salts, the contents were dissolvedin 1.0ml ofchloroform and washed once with 1.0 ml of1.0 NHC1and three times with 1.0 ml each ofdistilled water. The chloroform was evaporatedwith a stream of dry air (Mawhinney et al., 1980). For conversion to aldononitrile acetate (Varmer, et al., 1973), 0.6 ml of pyridine and 1.8 mlof acetic anhydride were added and the mixture was heated at 90° for 30 min. The solution was evaporated to dryness at 40° under diminishedpressure with a stream of nitrogen directed into the vessel.Neutral sugars are present in pitviper, elapid, lizard, and scorpion venoms (Table). D-arabinose and D-xylose were not detected in venomsofCrotalus molossus, C. scutulatus, and N.naja. Only trace amounts, less than 1 figper mg ofvenom, of these sugars were indicated in the othervenom analyses. Venom ofA.piscivorus piscivorus was relatively low inD-mannose. Otherwise, pit viper venoms contained abundant D-mannose,comparable amounts of L-fucose and D-galactose, and relatively small amounts of D-glucose. A. bilineatus venom was highest in all the sugarsassayed, except D-glucose. D-mannose was not the major sugar inthe elapid venom tested; however, D-mannose was dominant inthe lizard venom.Centruroides sculpturatus venom was higher in total neutral sugar than the other scorpion venoms.A significant unidentified peak (Fig.), probably indicating another neutral sugar, was recorded immediately prior to the D-mannose peakin the chromatograms of A.p. piscivorus, C. arrox, N. naja, and N. n. atra venom samples. This peak was minor or absent in the remainingchromatograms. Small unidentified peaks were also recorded immediately prior to the L-fucose peak.Sialic acid and amino sugar analyses of the above venoms are now inprogress.Table. Neutral Sugars in Various Venoms'*Vm« L-fuc P-««J °-«l" °-""Pit Vipers:A»kl»trodon blllnMtm 13.3 9.8 1.2 15.4Anklttrodon pl.clvonT pl.clvorUT 3.5 1.2 1.3 1.0Crot.lu. »tro» 3.0 2.7 1.9 5.6Crot.lu. molu..u. 2.0 2.1 1I1CI 3.0Crotilu. .cutul.tu. 2.5 6.0 tr.ce 8.3Crot.lu. 7lrldl. cerb.ru. 2.2 4.8 1.5 6.0mm^ » « a"Llxarda:H«iod«r»* horrldua 2.3 6.3 2.6 7.2H«lod«rma .u.pecty 2.0 4.5 trace 5.1Scorpion*:AndroctomiB auatralla 1.3 1.0 2.4 1.4Centruroldea aculptur»tu« 5.9 6.2 4.6 4.6Hadrurm "aTTxonmala 1.8 1.4 1.3 3.6Hjidruru. TTlrautua 1.4 4.4 1.4 4.0*ug of augar/ag of venon+ trace Indlcataa < 1.0 pg of augar/ng of venomvenom as aldononitrile acetates. The initial hold was at 170° for twominutes followed by an increase of 8°/min to a final temperature ot240°. Nitrogen flow rate was 24 ml/min and sample size was 4 pi.84Journal of the Arkansas Academy of Science, Vol. 37 [1983], Art. 27Published by Arkansas Academy of Science, 1983

https://scholarworks.uark.edu/cgi/viewcontent.cgi?article=2538&amp;context=jaas

Flat Plate Solar Thermal Collectors: A Comparison of Efficiencies of Various Collector Configurations

Abstract

Similar works

Full text

Available Versions

UARK (University of Arkansas )

ScholarWorks@UARK