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• 2751. [Article] Structure-property relationships in oxides containing tellurium

  Oxides of post-transition metals often show unique structures and properties due to the presence of lone pair electrons and the diffused s orbitals. The present work focuses on synthesis and characterizations ...

  Citation × Citation Citation Abstract Copy Title: Structure-property relationships in oxides containing tellurium Author: Siritanon, Theeranun Oxides of post-transition metals often show unique structures and properties due to the presence of lone pair electrons and the diffused s orbitals. The present work focuses on synthesis and characterizations of oxides containing Te, a heavy post transition metal. New series of pyrochlore oxides of the formula Cs(M,Te)₂O₆ (M = Al, Ga, Cr, Fe, Co, In, Ho, Lu, Yb, Er, Ge, Rh, Ti, Zn, Ni, and Mg) have been prepared. The samples were highly colored (ranging from black to dark green) indicating a possible mixed valency for Te with appreciable charge transfer between them in the octahedral sites. Electronic conductivity was observed in some phases and could be as high as 2S/cm (M=Ge). Seebeck coefficients of conducting samples show negative values which suggest that electrons are the major charge carriers. Temperature dependence of conductivity indicates that the samples are semiconductors with, in some cases, degenerate semiconducting behavior. Detailed studies on the conduction mechanism indicate the mixed valency of tellurium which leads to semiconducting behavior and the color of the compounds.Systematic studies of cesium tellurate with CsTe₂O[subscript 6-x] where x = 0, 0.15, 0.25, 1.5 have been investigated. On heating at slightly above 600ºC, CsTe₂O₆ loses oxygen resulting in cubic structure with disordered Te⁴⁺/Te⁶⁺ and oxygen vacancies. Two novel phases of CsTe₂O[subscript 6-x] were prepared with orthorhombic structure. The first phase with x value of about 0.2-0.3 crystallizes in Pnma symmetry. At higher values of x, a new compound was discovered with a structure related to Rb₄Te₈O₂₃. Optical properties of the compounds are consistent with their colors. CsTe₂O₆ belongs to class II mixed valency according to Robin and Day classification. However, structures and properties of CsTe₂O[subscript 6-x] phases indicate that they are class I mixed valence compounds. Series of compounds with formula CsTe[subscript 2-x]W[subscript x]O₆ with x=0.2-0.5 have been made which can be considered as solid solution of CsTe₂O₆ and CsTe₀.₅W₁.₅O₆. Although the two end members adopt rhombohedral and trigonal structure, these solid solution phases crystallize in cubic defect pyrochlore structure with W⁶⁺, Te⁶⁺, and Te⁴⁺ randomly occupying 16c octahedral site. The compounds show no electronic conductivity at room temperature. Novel cubic pyrochlore with the formula (CdBi)(MTe)O₇, M= Al, Cr, Ga, In, Fe, Mn, and Sc were synthesized by solid state reaction using oxides of the constituent elements. Magnetic properties analyses show paramagnetism in M=Cr and Mn but antiferromagnetism with short-range correlation in M= Fe phase. All compositions are insulating. Dielectric measurements show relatively low dielectric constants which are independent of temperature and frequency. Metallic Tl₂TeO₆ and insulating In₂TeO₆ are both known to crystallize in the Na₂SiF₆-type structure. We have now prepared a complete Tl[subscript 2-x]In[subscript x]TeO₆ series in a search for a compositionally controlled metal-insulator transition that might be expected if a complete solid solution can be obtained. Unit cell edges and volume vary monotonically with no indication of miscibility gap. The metal-insulator transition occurs at an x value of about 1.4, which can be rationalized on a percolation model. No superconductivity could be detected down to 5K. Rh₂MO₆, M = Mo, W, and Te were synthesized by solid state reaction. Electronic properties as well as thermoelectric properties were investigated and discussed. The compounds crystallize in rutile-related structure and all show relatively high electronic conductivities with Rh₂TeO₆ showing the highest electronic conductivity (~500 S/cm at room temperature) despite localized electrons in Rh³⁺ and Te⁶⁺. Measurable magnetic moments also indicate valence degeneracy between Rh and the M cation. The measured Seebeck coefficients are relatively low and positive indicating hole-type conduction. Title: Structure-property relationships in oxides containing tellurium Author: Siritanon, Theeranun Oxides of post-transition metals often show unique structures and properties due to the presence of lone pair electrons and the diffused s orbitals. The present work focuses on synthesis and characterizations of oxides containing Te, a heavy post transition metal. New series of pyrochlore oxides of the formula Cs(M,Te)₂O₆ (M = Al, Ga, Cr, Fe, Co, In, Ho, Lu, Yb, Er, Ge, Rh, Ti, Zn, Ni, and Mg) have been prepared. The samples were highly colored (ranging from black to dark green) indicating a possible mixed valency for Te with appreciable charge transfer between them in the octahedral sites. Electronic conductivity was observed in some phases and could be as high as 2S/cm (M=Ge). Seebeck coefficients of conducting samples show negative values which suggest that electrons are the major charge carriers. Temperature dependence of conductivity indicates that the samples are semiconductors with, in some cases, degenerate semiconducting behavior. Detailed studies on the conduction mechanism indicate the mixed valency of tellurium which leads to semiconducting behavior and the color of the compounds.Systematic studies of cesium tellurate with CsTe₂O[subscript 6-x] where x = 0, 0.15, 0.25, 1.5 have been investigated. On heating at slightly above 600ºC, CsTe₂O₆ loses oxygen resulting in cubic structure with disordered Te⁴⁺/Te⁶⁺ and oxygen vacancies. Two novel phases of CsTe₂O[subscript 6-x] were prepared with orthorhombic structure. The first phase with x value of about 0.2-0.3 crystallizes in Pnma symmetry. At higher values of x, a new compound was discovered with a structure related to Rb₄Te₈O₂₃. Optical properties of the compounds are consistent with their colors. CsTe₂O₆ belongs to class II mixed valency according to Robin and Day classification. However, structures and properties of CsTe₂O[subscript 6-x] phases indicate that they are class I mixed valence compounds. Series of compounds with formula CsTe[subscript 2-x]W[subscript x]O₆ with x=0.2-0.5 have been made which can be considered as solid solution of CsTe₂O₆ and CsTe₀.₅W₁.₅O₆. Although the two end members adopt rhombohedral and trigonal structure, these solid solution phases crystallize in cubic defect pyrochlore structure with W⁶⁺, Te⁶⁺, and Te⁴⁺ randomly occupying 16c octahedral site. The compounds show no electronic conductivity at room temperature. Novel cubic pyrochlore with the formula (CdBi)(MTe)O₇, M= Al, Cr, Ga, In, Fe, Mn, and Sc were synthesized by solid state reaction using oxides of the constituent elements. Magnetic properties analyses show paramagnetism in M=Cr and Mn but antiferromagnetism with short-range correlation in M= Fe phase. All compositions are insulating. Dielectric measurements show relatively low dielectric constants which are independent of temperature and frequency. Metallic Tl₂TeO₆ and insulating In₂TeO₆ are both known to crystallize in the Na₂SiF₆-type structure. We have now prepared a complete Tl[subscript 2-x]In[subscript x]TeO₆ series in a search for a compositionally controlled metal-insulator transition that might be expected if a complete solid solution can be obtained. Unit cell edges and volume vary monotonically with no indication of miscibility gap. The metal-insulator transition occurs at an x value of about 1.4, which can be rationalized on a percolation model. No superconductivity could be detected down to 5K. Rh₂MO₆, M = Mo, W, and Te were synthesized by solid state reaction. Electronic properties as well as thermoelectric properties were investigated and discussed. The compounds crystallize in rutile-related structure and all show relatively high electronic conductivities with Rh₂TeO₆ showing the highest electronic conductivity (~500 S/cm at room temperature) despite localized electrons in Rh³⁺ and Te⁶⁺. Measurable magnetic moments also indicate valence degeneracy between Rh and the M cation. The measured Seebeck coefficients are relatively low and positive indicating hole-type conduction. Close

• 2752. [Article] The Design, Manufacturing, and Testing of the 2014 Side-Pods for the Global Formula Racing Vehicle

  For many years, engine overhearing has been the major cause for vehicle breakdowns and engine malfunctions for most teams in Endurance events at Formula Society of Automotive Engineers (FSAE) Series competitions. ...

  Citation × Citation Citation Abstract Copy Title: The Design, Manufacturing, and Testing of the 2014 Side-Pods for the Global Formula Racing Vehicle Author: Volk, Austin R. For many years, engine overhearing has been the major cause for vehicle breakdowns and engine malfunctions for most teams in Endurance events at Formula Society of Automotive Engineers (FSAE) Series competitions. Additionally, with a growing importance of aerodynamics to the overall success of the Global Formula Racing at these events, in addition to an internal need for engine cooling, the side-pods have been a large focus of redesign for the 2014 season. The side-pods, which house oil and water radiators for engine cooling, are responsible for providing adequate airflow to maintain stable engine operating temperatures, while increasing downforce and reducing drag on the vehicle. This thesis details the complete design and manufacturing processes, followed by testing simulations and physical validation of the 2014 side-pods on the Global Formula Racing combustion and electric vehicles. Title: The Design, Manufacturing, and Testing of the 2014 Side-Pods for the Global Formula Racing Vehicle Author: Volk, Austin R. For many years, engine overhearing has been the major cause for vehicle breakdowns and engine malfunctions for most teams in Endurance events at Formula Society of Automotive Engineers (FSAE) Series competitions. Additionally, with a growing importance of aerodynamics to the overall success of the Global Formula Racing at these events, in addition to an internal need for engine cooling, the side-pods have been a large focus of redesign for the 2014 season. The side-pods, which house oil and water radiators for engine cooling, are responsible for providing adequate airflow to maintain stable engine operating temperatures, while increasing downforce and reducing drag on the vehicle. This thesis details the complete design and manufacturing processes, followed by testing simulations and physical validation of the 2014 side-pods on the Global Formula Racing combustion and electric vehicles. Close

• 2753. [Article] Neutron scattering studies of magnetic semiconducting superlattices

  Neutron diffraction experiments on europium telluride/lead telluride super-lattice systems reveal pronounced correlations between the antiferromagnetic EuTe layers. The results from an assortment of varying ...

  Citation × Citation Citation Abstract Copy Title: Neutron scattering studies of magnetic semiconducting superlattices Author: Goldman, Keith Isaac Neutron diffraction experiments on europium telluride/lead telluride super-lattice systems reveal pronounced correlations between the antiferromagnetic EuTe layers. The results from an assortment of varying experimental conditions (applied magnetic field, temperature, etc.) and their relevance to the physical mechanism underlying this striking phenomena are discussed. Stochastic computer simulations are compared to this real data to examine the effects of varying the neutron coherence length and the amount of correlations in the model sample. There are rising theoretical efforts to determine the physical mechanism causing the observed correlations and a laconic overview of current theories in interlayer coupling is given herein. The investigated structures do not exhibit perfect correlations between the magnetic layers but most samples clearly show correlation effects. The description of these partial correlations, characterized by an order parameter p, is examined and a straightforward method for determining p is derived. Title: Neutron scattering studies of magnetic semiconducting superlattices Author: Goldman, Keith Isaac Neutron diffraction experiments on europium telluride/lead telluride super-lattice systems reveal pronounced correlations between the antiferromagnetic EuTe layers. The results from an assortment of varying experimental conditions (applied magnetic field, temperature, etc.) and their relevance to the physical mechanism underlying this striking phenomena are discussed. Stochastic computer simulations are compared to this real data to examine the effects of varying the neutron coherence length and the amount of correlations in the model sample. There are rising theoretical efforts to determine the physical mechanism causing the observed correlations and a laconic overview of current theories in interlayer coupling is given herein. The investigated structures do not exhibit perfect correlations between the magnetic layers but most samples clearly show correlation effects. The description of these partial correlations, characterized by an order parameter p, is examined and a straightforward method for determining p is derived. Close

• 2754. [Article] The effect of phototherapy on dopamine in dextrose 5% water stability in vitro

  The stability of dopamine in dextrose 5% water subjected phototherapy was assessed. Solutions of dopamine (1000 mcg/ml) were prepared and triplicate samples were subjected to one of three light (normal, ...

  Citation × Citation Citation Abstract Copy Title: The effect of phototherapy on dopamine in dextrose 5% water stability in vitro Author: Dandurand, Kenneth R. The stability of dopamine in dextrose 5% water subjected phototherapy was assessed. Solutions of dopamine (1000 mcg/ml) were prepared and triplicate samples were subjected to one of three light (normal, dark, phototherapy) and two flow (2ml/hr. and no flow) conditions at ambient room temperature. Photo-irradiance was maintained between 5.1 and 6.6 watts/cm² throughout the experiment. Samples were assayed at intervals from 0 to 36 hours by high performance liquid chromatography (HPLC). There was no statistically significant decomposition of dopamine solutions exposed to phototherapy as compared to control samples over time. Dopamine in dextrose 5% water exposed to phototherapy is stable for 36 hours. The results of this study indicate that the need for additional protection of dopamine from blue light irradiance emitted by phototherapy is not needed to maintain stability during administration to neonates. Title: The effect of phototherapy on dopamine in dextrose 5% water stability in vitro Author: Dandurand, Kenneth R. The stability of dopamine in dextrose 5% water subjected phototherapy was assessed. Solutions of dopamine (1000 mcg/ml) were prepared and triplicate samples were subjected to one of three light (normal, dark, phototherapy) and two flow (2ml/hr. and no flow) conditions at ambient room temperature. Photo-irradiance was maintained between 5.1 and 6.6 watts/cm² throughout the experiment. Samples were assayed at intervals from 0 to 36 hours by high performance liquid chromatography (HPLC). There was no statistically significant decomposition of dopamine solutions exposed to phototherapy as compared to control samples over time. Dopamine in dextrose 5% water exposed to phototherapy is stable for 36 hours. The results of this study indicate that the need for additional protection of dopamine from blue light irradiance emitted by phototherapy is not needed to maintain stability during administration to neonates. Close

• 2755. [Article] Grass seed quality in relation to time of windrowing

  This study was undertaken to obtain information on the quality of grass seed when windrowed at the high moisture levels necessary for obtaining maximum yields. A secondary goal was to monitor moisture ...

  Citation × Citation Citation Abstract Copy Title: Grass seed quality in relation to time of windrowing Author: Dübbern de Souza, Francisco Humberto This study was undertaken to obtain information on the quality of grass seed when windrowed at the high moisture levels necessary for obtaining maximum yields. A secondary goal was to monitor moisture and temperature fluctuations in the windrow and to relate their effects to development and deterioration of the seed. Three species of perennial grasses were included in the study: tall fescue (Festuca arundinacea Schreb.) variety "Fawn", orchardgrass (Dactylis glomerata L.) variety "Potomac", and perennial ryegrass (Lolium perenne L.) variety "Linn". The effect of heading date on seed development at the recommended windrowing time was evaluated with individually tagged panicles. Tall fescue was windrowed on 28 June, 01 July and 06 July; orchardgrass on 28 June, 01 July and 06 July; and perennial ryegrass on 01 July, 06 July and 16 July. These dates were chosen to provide windrows mowed at moisture levels higher than, equal to, and lower than the optimum for maximum yields of pure live seed. Moisture and temperature fluctuations in the windrow were monitored and changes in seed development and deterioration were evaluated. Heading date influenced several seed quality characteristics at the recommended time for windrowing. Early inflorescences were lowest in seed moisture content. Tall fescue and perennial ryegrass seeds from the Late group, and orchardgrass seeds from the Intermediate and Late groups had not attained maximum seed weight. Seedlings of tall fescue and orchardgrass produced by seeds from the Late group had not attained maximum shoot weight. Seeds of all inflorescence age groups reached maximum viability several days before optimum windrowing date. Seed moisture contents when windrowed were 51.6, 41.5, and 15.9% in tall fescue, 44.8, 41.4 and 30.7% in orchardgrass, and 49.8, 28.5 and 19.1% in perennial ryegrass. During periods without rainfall, seed moisture decreased rapidly during the day, increased during the night, and decreased to a new low the following day. Several rains occurred during this period, raising seed moisture levels above 40%. During the drying period, seed moisture in the lower part of the perrenial ryegrass windrow was as much as 8% higher than seed in the upper part. The average maximum temperatures in the upper and lower portions of the perennial ryegrass windrow were 38.3 and 24. 3°C during July and 31.1 and 19. 2⁰C during August. The maximum temperature reached in the upper part was 47°C on 28 and 29 July. Each weeks' delay in windrowing resulted in improved seed quality, with the greatest improvement occurring between the first and second cutting, However, the data support Klein and Harmond's recommendations for windrowing tall fescue at 43% moisture, orchardgrass at 44% moisture, and perennial ryegrass at 35% moisture. Perennial ryegrass seed quality was not improved by delaying windrowing, while orchardgrass and tall fescue seeds increased somewhat in weight. Because of the risk of increased shattering losses, delaying windrowing to improve seed quality does not appear justified. A small amount of seed development took place while the seeds were in the windrow. Seed weight of tall fescue harvested at 51.6% moisture increased from 250.6 to 279.6 mg/ 100 seeds. No increase in seed weight occurred in the other species or windrowing dates. After several days in the windrow, speed of germination increased in all three species. Germination percentage, seedling emergence, and shoot weight did not improve after windrowing. Very little seed deterioration occurred during the first month in the windrow. A perceptible drop in germination of orchardgrass and perennial ryegrass occurred during the 2 weeks prior to the 19 August sampling date. Seed weight declined by the end of the experimental period in all three crops. Some germinated seeds were found in the perennial ryegras windrows by the end of August. No reduction in speed of germination or shoot weight occurred, while there was a trend toward reduced seedling emergence near the end of the experimental period. There were no indications that the stage of maturity when harvested influenced the rate of seed deterioration in the windrow. The probability of seed deterioration occurring at a faster rate than in 1976 is not great since a total of 75.69 mm (2.98 in) of rain fell during the experimental period, compared to a normal rainfall of 27.43 mm (1.08 in). Title: Grass seed quality in relation to time of windrowing Author: Dübbern de Souza, Francisco Humberto This study was undertaken to obtain information on the quality of grass seed when windrowed at the high moisture levels necessary for obtaining maximum yields. A secondary goal was to monitor moisture and temperature fluctuations in the windrow and to relate their effects to development and deterioration of the seed. Three species of perennial grasses were included in the study: tall fescue (Festuca arundinacea Schreb.) variety "Fawn", orchardgrass (Dactylis glomerata L.) variety "Potomac", and perennial ryegrass (Lolium perenne L.) variety "Linn". The effect of heading date on seed development at the recommended windrowing time was evaluated with individually tagged panicles. Tall fescue was windrowed on 28 June, 01 July and 06 July; orchardgrass on 28 June, 01 July and 06 July; and perennial ryegrass on 01 July, 06 July and 16 July. These dates were chosen to provide windrows mowed at moisture levels higher than, equal to, and lower than the optimum for maximum yields of pure live seed. Moisture and temperature fluctuations in the windrow were monitored and changes in seed development and deterioration were evaluated. Heading date influenced several seed quality characteristics at the recommended time for windrowing. Early inflorescences were lowest in seed moisture content. Tall fescue and perennial ryegrass seeds from the Late group, and orchardgrass seeds from the Intermediate and Late groups had not attained maximum seed weight. Seedlings of tall fescue and orchardgrass produced by seeds from the Late group had not attained maximum shoot weight. Seeds of all inflorescence age groups reached maximum viability several days before optimum windrowing date. Seed moisture contents when windrowed were 51.6, 41.5, and 15.9% in tall fescue, 44.8, 41.4 and 30.7% in orchardgrass, and 49.8, 28.5 and 19.1% in perennial ryegrass. During periods without rainfall, seed moisture decreased rapidly during the day, increased during the night, and decreased to a new low the following day. Several rains occurred during this period, raising seed moisture levels above 40%. During the drying period, seed moisture in the lower part of the perrenial ryegrass windrow was as much as 8% higher than seed in the upper part. The average maximum temperatures in the upper and lower portions of the perennial ryegrass windrow were 38.3 and 24. 3°C during July and 31.1 and 19. 2⁰C during August. The maximum temperature reached in the upper part was 47°C on 28 and 29 July. Each weeks' delay in windrowing resulted in improved seed quality, with the greatest improvement occurring between the first and second cutting, However, the data support Klein and Harmond's recommendations for windrowing tall fescue at 43% moisture, orchardgrass at 44% moisture, and perennial ryegrass at 35% moisture. Perennial ryegrass seed quality was not improved by delaying windrowing, while orchardgrass and tall fescue seeds increased somewhat in weight. Because of the risk of increased shattering losses, delaying windrowing to improve seed quality does not appear justified. A small amount of seed development took place while the seeds were in the windrow. Seed weight of tall fescue harvested at 51.6% moisture increased from 250.6 to 279.6 mg/ 100 seeds. No increase in seed weight occurred in the other species or windrowing dates. After several days in the windrow, speed of germination increased in all three species. Germination percentage, seedling emergence, and shoot weight did not improve after windrowing. Very little seed deterioration occurred during the first month in the windrow. A perceptible drop in germination of orchardgrass and perennial ryegrass occurred during the 2 weeks prior to the 19 August sampling date. Seed weight declined by the end of the experimental period in all three crops. Some germinated seeds were found in the perennial ryegras windrows by the end of August. No reduction in speed of germination or shoot weight occurred, while there was a trend toward reduced seedling emergence near the end of the experimental period. There were no indications that the stage of maturity when harvested influenced the rate of seed deterioration in the windrow. The probability of seed deterioration occurring at a faster rate than in 1976 is not great since a total of 75.69 mm (2.98 in) of rain fell during the experimental period, compared to a normal rainfall of 27.43 mm (1.08 in). Close

• 2756. [Article] Thermal properties of wood fiber networks

  The standard (ASTM) steady-state method for determining the thermal conductivity of insulating materials (like wood based composite materials) is time-consuming, and its use is therefore limited to dry ...

  Citation × Citation Citation Abstract Copy Title: Thermal properties of wood fiber networks Author: Shao, Ming The standard (ASTM) steady-state method for determining the thermal conductivity of insulating materials (like wood based composite materials) is time-consuming, and its use is therefore limited to dry material; moisture migration occurs in hydrated materials and this limits accuracy. The proposed unsteady-state method is fast and therefore enables thermal properties of hygroscopic materials to be measured. The specimens are pressed by hot platens and the temperature rise inside them is measured. By comparing experimental data with the theoretical solutions of the "heat equation", thermal properties are determined using error minimization computer programs. The thermal properties of wood fiber networks have been measured as a function of density and moisture content. The results will be used in computer models which simulate the hot pressing of wood based composites. Title: Thermal properties of wood fiber networks Author: Shao, Ming The standard (ASTM) steady-state method for determining the thermal conductivity of insulating materials (like wood based composite materials) is time-consuming, and its use is therefore limited to dry material; moisture migration occurs in hydrated materials and this limits accuracy. The proposed unsteady-state method is fast and therefore enables thermal properties of hygroscopic materials to be measured. The specimens are pressed by hot platens and the temperature rise inside them is measured. By comparing experimental data with the theoretical solutions of the "heat equation", thermal properties are determined using error minimization computer programs. The thermal properties of wood fiber networks have been measured as a function of density and moisture content. The results will be used in computer models which simulate the hot pressing of wood based composites. Close

• 2757. [Article] Preparation and comparative solubility of poly-L-tyrosyl lysozyme and poly-O-methyl-L-tyrosyl lysozyme

  In order to examine some possible tyrosyl interactions, poly-tyrosyl lysozyme and poly-O-methyltyrosyl lysozyme were prepared and their solubilities were compared. Both derivatives exhibited similar pH ...

  Citation × Citation Citation Abstract Copy Title: Preparation and comparative solubility of poly-L-tyrosyl lysozyme and poly-O-methyl-L-tyrosyl lysozyme Author: Venier, Lynn Corrine In order to examine some possible tyrosyl interactions, poly-tyrosyl lysozyme and poly-O-methyltyrosyl lysozyme were prepared and their solubilities were compared. Both derivatives exhibited similar pH dependent solubilities, showing a minimum solubility at about pH 8. Their solubilities varied with temperature, having a positive enthalpy of solution. The effect of a lyotropic series of ions on the solubility of these lysozyme derivatives followed the same order in their ability to solubilize these derivatives as their ability to disaggregate proteins. The tyrosyl and O-methyltyrosyl lysozyme aggregations are believed to be due to interactions which cannot be delineated as singly hydrophobic, ionic or polar interactions. Title: Preparation and comparative solubility of poly-L-tyrosyl lysozyme and poly-O-methyl-L-tyrosyl lysozyme Author: Venier, Lynn Corrine In order to examine some possible tyrosyl interactions, poly-tyrosyl lysozyme and poly-O-methyltyrosyl lysozyme were prepared and their solubilities were compared. Both derivatives exhibited similar pH dependent solubilities, showing a minimum solubility at about pH 8. Their solubilities varied with temperature, having a positive enthalpy of solution. The effect of a lyotropic series of ions on the solubility of these lysozyme derivatives followed the same order in their ability to solubilize these derivatives as their ability to disaggregate proteins. The tyrosyl and O-methyltyrosyl lysozyme aggregations are believed to be due to interactions which cannot be delineated as singly hydrophobic, ionic or polar interactions. Close

• 2758. [Article] The influence of some environmental factors on the distribution of fishes in Upper Klamath Lake

  The fishes of Upper Klamath Lake appeared to distribute themselves in three general groups during the summers of 1964 and 1965: (1) the chubs--unrestricted as to distribution with slight seasonal variations; ...

  Citation × Citation Citation Abstract Copy Title: The influence of some environmental factors on the distribution of fishes in Upper Klamath Lake Author: Vincent, David Thomas The fishes of Upper Klamath Lake appeared to distribute themselves in three general groups during the summers of 1964 and 1965: (1) the chubs--unrestricted as to distribution with slight seasonal variations; (2) rainbow trout and yellow perch -- restricted to certain water conditions that exist only along the northern marsh and spring areas of the lake; (3) the brown bullhead and sculpins -- and possibly suckers -- partially restricted by water conditions and shoreline habitat. The limnological conditions favorable for the above distributions prevail from May until early October at which time the water temperature, nuisance algal populations and pH values are all decreasing, creating favorable conditions for all previously restricted species throughout the entire lake. Title: The influence of some environmental factors on the distribution of fishes in Upper Klamath Lake Author: Vincent, David Thomas The fishes of Upper Klamath Lake appeared to distribute themselves in three general groups during the summers of 1964 and 1965: (1) the chubs--unrestricted as to distribution with slight seasonal variations; (2) rainbow trout and yellow perch -- restricted to certain water conditions that exist only along the northern marsh and spring areas of the lake; (3) the brown bullhead and sculpins -- and possibly suckers -- partially restricted by water conditions and shoreline habitat. The limnological conditions favorable for the above distributions prevail from May until early October at which time the water temperature, nuisance algal populations and pH values are all decreasing, creating favorable conditions for all previously restricted species throughout the entire lake. Close

• 2759. [Article] Analytical and numerical analysis of natural circulation for reactor cavity cooling system in gas cooled reactor

  Among the Generation IV reactors, the Very High Temperature Reactor (VHTR) is being considered as the ideal design for a Next Generation Nuclear Plant (NGNP). The VHTR system is designed for a gas cooled ...

  Citation × Citation Citation Abstract Copy Title: Analytical and numerical analysis of natural circulation for reactor cavity cooling system in gas cooled reactor Author: Lee, Dongyoung Among the Generation IV reactors, the Very High Temperature Reactor (VHTR) is being considered as the ideal design for a Next Generation Nuclear Plant (NGNP). The VHTR system is designed for a gas cooled reactor and originates from modifying and further developing the 600MW Gas Turbine-Module Helium Reactor (GTMHR). The GT-MHR system has inherent safety features that make events leading to a severe accident significantly unlikely. The Reactor Cavity Cooling System (RCCS) is a crucial component in passive decay heat removal using air natural convection. The PIRT (Phenomena Identification and Ranking Table) for the RCCS was developed through evaluations of physical phenomena which might arise during a LBLOCA. In addition, this study presents the basic performance for the RCCS using analytical and numerical analysis. Title: Analytical and numerical analysis of natural circulation for reactor cavity cooling system in gas cooled reactor Author: Lee, Dongyoung Among the Generation IV reactors, the Very High Temperature Reactor (VHTR) is being considered as the ideal design for a Next Generation Nuclear Plant (NGNP). The VHTR system is designed for a gas cooled reactor and originates from modifying and further developing the 600MW Gas Turbine-Module Helium Reactor (GTMHR). The GT-MHR system has inherent safety features that make events leading to a severe accident significantly unlikely. The Reactor Cavity Cooling System (RCCS) is a crucial component in passive decay heat removal using air natural convection. The PIRT (Phenomena Identification and Ranking Table) for the RCCS was developed through evaluations of physical phenomena which might arise during a LBLOCA. In addition, this study presents the basic performance for the RCCS using analytical and numerical analysis. Close

• 2760. [Article] Interconversions of monoterpenes in peppermint

  The analysis of the distribution of monoterpenes through the leaf pairs of a single shoot of Mentha piperita supports Reitsema's contention that the first terpenes formed are unsaturated ketones and that ...

  Citation × Citation Citation Abstract Copy Title: Interconversions of monoterpenes in peppermint Author: Burbott, Alice Joyce The analysis of the distribution of monoterpenes through the leaf pairs of a single shoot of Mentha piperita supports Reitsema's contention that the first terpenes formed are unsaturated ketones and that saturated terpenes are produced from these. The growth of Mentha piperita under varying conditions of temperature and the leaf-by-leaf analysis of the terpene composition of the oil demonstrate effects of environmental factors on terpene formation and interconversion. Time-course studies using C¹⁴O₂ support this portion of Reitsema's scheme: pulegone yields menthone yields menthol yields menthyl acetate. A seventy-two hour time-course with alternating periods of illumination and darkness demonstrates the interconversion of terpenes in the presence or absence of light. The conversion of pulegone to menthone; menthone to menthol and menthyl acetate; and piperitenone to pulegone, menthone and piperitone has been observed in peppermint tissue using labeled terpenes as substrates. Title: Interconversions of monoterpenes in peppermint Author: Burbott, Alice Joyce The analysis of the distribution of monoterpenes through the leaf pairs of a single shoot of Mentha piperita supports Reitsema's contention that the first terpenes formed are unsaturated ketones and that saturated terpenes are produced from these. The growth of Mentha piperita under varying conditions of temperature and the leaf-by-leaf analysis of the terpene composition of the oil demonstrate effects of environmental factors on terpene formation and interconversion. Time-course studies using C¹⁴O₂ support this portion of Reitsema's scheme: pulegone yields menthone yields menthol yields menthyl acetate. A seventy-two hour time-course with alternating periods of illumination and darkness demonstrates the interconversion of terpenes in the presence or absence of light. The conversion of pulegone to menthone; menthone to menthol and menthyl acetate; and piperitenone to pulegone, menthone and piperitone has been observed in peppermint tissue using labeled terpenes as substrates. Close