29,624 research outputs found
Nonelastic nuclear reactions and accompanying gamma radiation
Several aspects of nonelastic nuclear reactions which proceed through the formation of a compound nucleus are dealt with. The full statistical model and the partial statistical model are described and computer programs based on these models are presented along with operating instructions and input and output for sample problems. A theoretical development of the expression for the reaction cross section for the hybrid case which involves a combination of the continuum aspects of the full statistical model with the discrete level aspects of the partial statistical model is presented. Cross sections for level excitation and gamma production by neutron inelastic scattering from the nuclei Al-27, Fe-56, Si-28, and Pb-208 are calculated and compared with avaliable experimental data
Acoustic spectral analysis and testing techniques
Subjects covered in four reports are described including: (1) mathematical techniques for combining decibel levels of octaves or constant bandwidth: (2) techniques for determining equation for power spectral density function; (3) computer program to analyze acoustical test data; and (4) computer simulation of horn responses utilizing hyperbolic horn theory
Gypsy moths and American dog ticks: Space partners
An experiment intended for the space shuttle and designed to investigate the effects of weightlessness and total darkness on gypsy moth eggs and engorged American dog ticks is described. The objectives are: (1) to reevaluate the effects of zero gravity on the termination of diapause/hibernation of embryonated gypsy moth eggs, (2) to determine the effect of zero gravity on the ovipositions and subsequent hatch from engorged female American dog ticks that have been induced to diapause in the laboratory, and (3) to determine whether morphological or biochemical changes occur in the insects under examination. Results will be compared with those from a similar experiment conducted on Skylab 4
The application of semiconductors to quasi- optical isolators for use at submillimeter wavelengths
Semiconductor application to quasi-optical isolators - nonreciprocal reflection beam isolator and far infrared isolators using Faraday rotatio
3-Step Synthesis of Caffeic Acid Phenethyl Ester
Caffeic Acid Phenethyl Ester (CAPE) is the active polyphenol of propolis, a resin-like material that acts as a natural sealant in honeybee hives. Studies suggest that CAPE has notable human health benefits, for it inhibits the activity of 5-lipoxygenase (5-LO)—a key enzyme in the metabolism of arachidonic acid (AA) to leukotriene A4 (LTA4)—and thus hinders the development of a variety of diseases such as inflammatory bowel disease, atherosclerosis, and asthma. Although CAPE can be found in nature, it may not be readily available; mastering its synthesis in the laboratory setting renders it available for wider human use. The proposed three-step synthesis of CAPE demonstrates the utilization of protecting groups in ether formation. Caffeic acid is acetylated with acetic anhydride in step one. The resulting intermediate is converted to a readily reactive acid (carboxylic) chloride by treatment with a Vilsmeier-Haack intermediate under dimethylformamide (DMF) activation. Step two then continues with alcoholysis, as the acid chloride intermediate and 2-phenylethanol are allowed to react— producing the acetylated ester intermediate form of CAPE. In the final step, base-induced de-O-acetylation with potassium carbonate in methanol and dichloromethane removes the acetyl protecting groups and reinstalls alcohol. In attempt to make this synthesis more green, highly reactive and hazardous acetic anhydride is replaced with a combination of glacial acetic acid (ethanoic acid) and zinc dust for acetylation in step one. If the proposed green step is successful, an alternative manner for installing protective groups will be achieved. Factors of cost, efficiency, reaction rate, and time must be further considered before accepting the proposed synthesis as a beneficial green alternative to traditional methods
Enhancing the nutritional quality of flour tortillas: An investigation of consumer receptivity to a fortified tortilla product
The majority of U.S. adults consume less than the recommended amount of whole grains, dietary fiber, and vegetables on a daily basis. Increased intake of these foods is linked with reduced risks of developing chronic diseases. With increased prevalence of chronic health conditions and inadequate intakes of whole grains and vegetables, the need for an appealing enriched food product is evident. Over the past decade, the tortilla industry has been the fastest-growing sector of the U.S. baking industry; therefore, enhancing the nutritional content of tortillas could result in healthier food products acceptable to consumers. This research aimed to determine the effects of altering the flour component and adding a legume ingredient, specifically lentils, on the sensory attributes and overall characteristics of flour tortillas. Sorghum, an ancient whole grain variety, is rich in antioxidants, dietary fiber, and iron. Lentils, a type of grain legume, are high in fiber, B vitamins, minerals, and protein. Ten phases of bench-top product development were completed, resulting in two optimal fortified tortilla product formulations. Sensory evaluations were conducted among college students and instructors (n=35) for sensory attributes and overall likeability of four samples: two fortified tortilla products, a commercial tortilla made with refined flour, and a commercial health-enhanced tortilla. Results indicate that fortified tortilla products enhanced with pureed cooked lentils and sorghum flour are acceptable among the sampled population. Future research opportunities include conducting sensory evaluations among a larger population, optimizing product formulation for commercial production, and further enhancing nutritional qualities with other grains and legumes
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