42 research outputs found
Dietary Changes by Expanded Food and Nutrition Education Program (EFNEP) Graduates Are Independent of Program Delivery Method
Dietary changes of Expanded Food and Nutrition Education Program (EFNEP) graduates who participated in either individual or group education sessions were assessed. Paraprofessionals administered the Homemaker\u27s 24-Hour Food Recall to EFNEP graduates. EFNEP graduates significantly improved the number of servings consumed from the grains, vegetables, dairy, and meat and meat alternates food groups. Graduates also significantly increased total calories consumed, dietary fiber intake, as well as iron, calcium, vitamin A, vitamin C, and vitamin B6 intake. These results were independent of method of nutrition education. Further research should determine the reasons why group instruction is as effective as individual instruction
Ferns of Royal Palm Hammock, descriptions and illustrations of the ferns and fern-allies growing naturally in Royal Palm Hammock and the adjacent Everglades,
Dietary Changes by Expanded Food and Nutrition Education Program (EFNEP) Graduates Are Independent of Program Delivery Method
Dietary changes of Expanded Food and Nutrition Education Program (EFNEP) graduates who participated in either individual or group education sessions were assessed. Paraprofessionals administered the Homemaker\u27s 24-Hour Food Recall to EFNEP graduates. EFNEP graduates significantly improved the number of servings consumed from the grains, vegetables, dairy, and meat and meat alternates food groups. Graduates also significantly increased total calories consumed, dietary fiber intake, as well as iron, calcium, vitamin A, vitamin C, and vitamin B6 intake. These results were independent of method of nutrition education. Further research should determine the reasons why group instruction is as effective as individual instruction
Observation of n-type behavior in Fe-doped tetrahedrite at low temperature
Tetrahedrite exhibits favorable thermoelectric properties, while also being composed of non-toxic and earth-abundant elements. Although tetrahedrite has been studied extensively as a p-type thermoelectric, n-type behavior in this material has not yet been observed. We report the first findings of n-type conductivity in tetrahedrite observed over a temperature range of 80 to 310 K, with typical p-type conductivity found at higher temperatures. Herein, we characterize electrical and thermal transport properties on these samples from 80 to 673 K. Mechanical alloying and modified polyol synthesis methods were used to synthesize Fe-doped samples (Cu12-xFexSb4S13 with x = 1, 1.3, and 1.5) by solid-state and solution-phase approaches, respectively. Elemental analysis by energy-dispersive X-ray spectroscopy was conducted to investigate the relationship between thermoelectric properties and chemical composition. A maximum ZT = 0.67 at 673 K was obtained for Cu10.5Fe1.5Sb4S13 synthesized by the modified polyol process. Our observation of negative Seebeck coefficient values in the low-temperature regime should serve as a foundation for further study of n-type behavior in tetrahedrite materials
Modified Polyol Synthesis of Tetrahedrite (Cu12Sb4S13)
Synthesizing thermoelectric materials by low-cost, low-energy methods can potentially alleviate the current energy crisis because of the ability of these materials to convert waste heat into electrical current. While most thermoelectric materials contain rare earth metals, tetrahedrite is composed of earth-abundant elements and exhibits high performing thermoelectric properties due to a low thermal conductivity from its complex unit cell. A solution phase, solid-state synthesis technique known as the modified polyol process was used to synthesize pure tetrahedrite nanoparticles. These nanoparticles were characterized by powder x-ray diffractometry, scanning electron microscopy, and energy dispersive x-ray spectroscopy. Thermopower, electrical resistivity and thermal conductivity measurements were taken for this material to determine the maximum figure of merit (ZT) values, which describes the efficiency of the energy conversion. The values found for our materials were on par with or exceed those of tetrahedrite fabricated by conventional high energy and time consuming processes. Cu sites can be doped with Zn to improve efficiency and the reaction was scaled up to produce over 2 grams of material, which enabled the thermoelectric characterization of nanomaterials from a single batch reaction
EXPERIMENTS ON THE CONTROL OF WART DISEASE OF POTATOES BY SOIL TREATMENT WITH PARTICULAR REFERENCE TO THE USE OF SULPHUR
The viability of the winter sporangium of Synchytrium Endobioticum (Schilb.) Perc., the organism causing wart disease in potato
SUMMARY A staining method for testing the viability of the winter sporangia of Synchytrium endobioticum is described. The sporangial contents are pressed out into acid fuchsin or after treatment by a strongly alkaline reagent into methylene blue. The staining reactions have been correlated with the results of infection experiments in pots. Sporangia which, like the controls stain faintly, produce a high percentage infection and are therefore alive. Those which stain deeply and rapidly produce no infection and are presumably dead. There is an intermediate group in which some sporangia stain deeply and some are intermediate in reaction. This group tends to give less infection than the controls. A method whereby sporangia which have been treated in soil may be extracted without affecting their viability is described. The method depends on the difference in specific gravity of sporangia which has been determined as about 1.17 and of soil which is in the region of 2.5. The sporangia are extracted by means of chloroform (sp. gr. 1.5 approx.), which does not affect their viability. A study of the relation of temperature, time and viability shows that treatment for 5 minutes at 90°C., 15 minutes at 80°C., 1 hour at 70°C. and 8 hours at 60°C. have a similar effect in killing all the sporangia
Thermoelectric Performance of Tetrahedrite Synthesized by a Modified Polyol Process
Synthesis has been demonstrated for undoped and zinc-doped tetrahedrite samples on the gram scale requiring only 1 h at 220 °C. This method is capable of incorporating dopants and producing particles in the 50-200 nm size regime. For determination of bulk thermoelectric properties, powders produced by this solution-phase method were densified into pellets by spark plasma sintering. Thermopower, electrical resistivity, and thermal conductivity were obtained for temperatures ranging from 323 to 723 K. Maximum ZT values at 723 K were found to be 0.66 and 1.09 for the undoped and zinc-doped tetrahedrite samples, respectively. These values are comparable to or greater than those obtained using time and energy intensive conventional solid-state methods. Consolidated pellets fabricated using nanomaterial produced by this solution-phase method were found to have decreased thermal conductivity, increased electrical resistivity, and increased thermopower. Exceptionally low total thermal conductivity values were found (below 0.7 W m-1 K-1 for undoped tetrahedrite and 0.5 W m-1 K-1 for zinc-doped tetrahedrite), with both having lattice thermal conductivities below 0.4 W m-1 K-1. This study explores how nanostructuring and doping of tetrahedrite via a solution-phase polyol process impacts thermoelectric performance