Organic Rankine cycle receiver development

The selected receiver concept is a direct-heated, once-through, monotube boiler operated at supercritical pressure. The cavity is formed by a cylindrical copper shell and backwall, with stainless steel tubing brazed to the outside surface. This core is surrounded by lightweight refractory insulation, load-bearing struts, and an outer case. The aperture plate is made of copper to provide long life by conduction and reradiation of heat away from the aperture lip. The receiver thermal efficiency is estimated to be 97 percent at rated conditions (energy transferred to toluene divided by energy incident on aperture opening). Development of the core manufacturing and corrosion protection methods is complete

Potential of Utilizing Scrap Processed Cheese as a Major Ration Component for Channel Catfish

Three cages (0.9 m³) were stocked with 200 channel catfish, Ictalurus punctatus Rafinesque, fingerlings (73.7 g avg.) in a 1.5 hectare pond. Two cheese rations were formulated and fed to the catfish; the first consisting of cheese, oil, and vitamin C (C + VC)and the second consisting of cheese, cottonseed meal, oil, trace minerals, and vitamins (CC + VM). A commercial trout ration (TC) was fed as a control. High mortalities occurred in the C + VC diet, thus resulting in premature removal of that cage from the study (after 86 days). A sample of 50 fish from the two remaining cages, along with harvest data from the C + VC diet, revealed a 45.6% difference in average fish weight between the C + VC and CC + VM diets, a 63.5% difference between the C + VC diet and TC ration, and 32.9% difference between the CC + VM diet and TC ration. Final harvest of CC + VM and TC cages was completed after 134 days. Comparisons revealed that a 38.3% difference in average fish weight existed between these two diets. Statistical analysis of data indicated that fish fed the CC + VM diet had a significantly lower percentage dress-out weight and a significantly higher amount of mesenteric fat. This experiment does suggest that cheese scraps, when properly balanced with other essential ingredients, may be utilized as a major component of catfish rations

Rapid Detection of o-Hydroxycinnamic Acid and Beta-Glucosidase in \u3ci\u3eMelilotus alba\u3c/i\u3e

The tests utilize small samples of leaf tissue crushed on sheets of filter paper. For detection of o-hydroxycinnamic acid (o-HCA), a crude preparation containing sweetclover β-glucosidase is added to a spot of crushed tissue to insure hydrolysis of glucosidically bound o-HCA. An extract containing cis-o-HCA glucoside is added to another tissue spot to serve as the substrate for the detection of β-glucosidase activity. Finally, all spots are moistened with NaOH and are scored for fluorescence under ultraviolet light. Results of qualitative and quantitative tests on plants representing various genotypes are compared. The importance of exposing plants to sunlight before testing for o-HCA is discussed. The tests are particularly useful in genetic studies, in the development and maintenance of breeding lines, and in testing for contamination in low-o-HCA sweetclover varieties

Evaluation of a Full-Fat Soybean Ration for Channel Catfish Production in Cages

An experimental ration consisting of 50% full-fat soybeans, heated 170°C, was compared to a commercial trout chow in a 120-day feeding trial using two stocks of channel catfish, Ictalurus punctatus Rafinesque. Catfish were reared in 0.9 m³ floating cages, with 200 fish per cage, anchored in a 1.5 hectare farm pond. A Central Arkansas stock significantly outperformed a Southeast Arkansas stock for comparisons of net production and food conversion efficiency (FCE), with 92% greater production and 41% better FCE, respectively. Survival was 90% or greater for all fish. There was no significant difference in dress-out weight between the stocks. However, the catfish fed the trout ration had significantly lower amounts of body fat. The commercial trout chow overall was significantly better for fish production than the full-fat soybean ration. Production with trout chow was 84% greater than with the full-fat soybean ration. Food conversion efficiency was nearly 41% better with the trout ration, while percent body fat was 11% less. There were no differences in percent survival and percent dress-out weight between the rations. The Central Arkansas stock fed the commercial trout ration had the lowest production cost of 0.47¢ per 0.45 kg live weight, while the Southeastern stock had a higher production cost with either feed

Registration of N30-N56, N741, N743, N745, N747, U362, U363, U367, U369-U374, U389-U394, U396-U398, and U500 Sweetclover Genetic Stocks

Forty-nine white-flowered sweetclover (Melilotus alba Medik.) genetic stocks [N30-N45 (Reg. GS-1–16, PI 549120–549135); N46-N53 (Reg. GS-17–24, PI 557503–PI 557510); N54-N55 (Reg. GS-25–Reg. GS-26, PI 629289–PI 629290); N741, N743, N745, N747 (Reg. GS-27–GS-30, PI 557511–PI 557514); U362, U363, U367 (Reg. GS-31, Reg. GS-32, Reg. GS-33, PI 557515–PI 557517); U369-U374 (Reg. GS-34–GS 39, PI 557518–PI 557523); U389-U394 (Reg. GS-40–GS 45, PI 557524–PI 557529); U396- U398 (Reg. GS-46–GS 48, PI 557530–PI 557532); U500 (Reg. GS-49, PI 557533)] (Table 1); and N56 (Reg. no. GS-50, PI 634019), a yellow-flowered sweetclover [Melilotus officinalis (L.) Lam.] genetic stock, were developed jointly by USDA- ARS and the Agricultural Research Division, Institute of Agriculture and Natural Resources, University of Nebraska-Lincoln and were jointly released in May 2004. The genetic stocks, which contain unique combinations of genes and traits, were developed over more than three decades of cooperative sweet- clover genetic research

Seasonal Variation in Leaf Hydrocyanic Acid Potential of Low- and High-Dhurrin Sorghums

The KSS and N32 sorghum [Sorghum bicolor (L.) Moench) lines are low and high, respectively, in the hydrocyanic acid potential (HCN-p) of mature leaves. This difference is conditioned primarily by a single pair of alleles. The main objective of this study was to determine, at various stages of plant growth and various times during the growing season, the HCN-p of upper leaves and tillers of field-grown plants of these two parental lines and of two low-HCN-p F F3 lines derived from crosses between KS8 and N32. The four entries were grown in a randomized complete block design with three replications in 1985. Samples of leaf tissue were dried, ground, and extracted, and cyanide in the extracts was assayed colorimetrically. Using a mean HCN-p level of 500 mg kg-1 dry wt to separate safe from unsafe sorghum forage, all samples of KS8 mature leaves and tillers would be considered safe, and all N32 samples would be considered potentially dangerous. Values for most of the samples of the F3 lines fell within the safe range, but some samples of young regrowth exceeded the 500 mg kg-1 limit. Regressions of HCN-p on height for upper leaves of main stems and of tillers indicated a significant negative relationship for all entries except for leaves from the main stems of KS8. However, the relationship was not close enough to support the use of plant or tiller height as a reliable indicator of HCN-p. Levels of HCN-p also were determined for mature leaves and young regrowth of hybrids involving KS8, N32, and \u27Redlan\u27 sorghums as seed parents and NP25, \u27Piper,\u27 and ‘Greenleaf’ sudangrasses [S. sudanense (Piper) Stapf] as pollinators. Results indicated that for minimizing the risk of cyanide poisoning, KS8 would be the seed parent of choice, and NP2S and Piper would be the preferred pollinators

Genetic Studies of Induced Mutants in \u3ci\u3eMelilotus alba\u3c/i\u3e. I. Short-Internode Dwarf, Curled Leaf, Multifoliolate Leaf, and Cotyledonary Branching

Information obtained from the F1, F2, and F3 generations of crosses between the normal annual M. alba progenitor line and the four mutants, short-internode dwarf, curled leaf, multifoliolate leaf, and cotyledonary branching, indicates that each character is conditioned by a single pair of alleles. The multifoliolate leaf character is dominant over the normal phenotype; the other three mutant characters are recessive. The symbols dw, cl, Mf, and cb are proposed as designations for the respective mutant genes

Registration of N30-N56, N741, N743, N745, N747, U362, U363, U367, U369-U374, U389-U394, U396-U398, and U500 Sweetclover Genetic Stocks

Forty-nine white-flowered sweetclover (Melilotus alba Medik.) genetic stocks [N30-N45 (Reg. GS-1–16, PI 549120–549135); N46-N53 (Reg. GS-17–24, PI 557503–PI 557510); N54-N55 (Reg. GS-25–Reg. GS-26, PI 629289–PI 629290); N741, N743, N745, N747 (Reg. GS-27–GS-30, PI 557511–PI 557514); U362, U363, U367 (Reg. GS-31, Reg. GS-32, Reg. GS-33, PI 557515–PI 557517); U369-U374 (Reg. GS-34–GS 39, PI 557518–PI 557523); U389-U394 (Reg. GS-40–GS 45, PI 557524–PI 557529); U396- U398 (Reg. GS-46–GS 48, PI 557530–PI 557532); U500 (Reg. GS-49, PI 557533)] (Table 1); and N56 (Reg. no. GS-50, PI 634019), a yellow-flowered sweetclover [Melilotus officinalis (L.) Lam.] genetic stock, were developed jointly by USDA- ARS and the Agricultural Research Division, Institute of Agriculture and Natural Resources, University of Nebraska-Lincoln and were jointly released in May 2004. The genetic stocks, which contain unique combinations of genes and traits, were developed over more than three decades of cooperative sweet- clover genetic research

Quality Traits in Forage Sorghum Harvested at Early Head Emergence and at Physiological Maturity

Information about the extent of variation in quality traits among plants sampled at the same developmental stage but on different dates would be useful to forage researchers. The primary purpose of this study was to obtain such information for five forage sorghum [Sorghum bicolor (L.) Moench] cultivars. Percent dry matter, crude protein, and in vitro dry matter disappearance of leaf, stem, and whole plant samples were determined for field-grown samples harvested on three different days during early head emergence (EHE) and once during physiological maturity (PM) for each cultivar. Orthogonal comparisons between EHE and PM sampling stages and among the• EHE samples were made. Results of the 2-year study indicated that statistically significant differences existed among EHE samples and between EHE and PM samples. However, differences among EHE samples were generally much smaller than those between EHE and PM samples and may be of little importance for some applications

Inheritance of Flower Color in Musk Thistle (\u3ci\u3eCarduus thoermeri\u3c/i\u3e)

Four flower-color phenotypes were observed in a population of musk thistle (Carduus tboermeri Weinm.). This plant has been commonly referred to as C. nutans L. The four phenotypes were: purple corolla and purple pollen, pink corolla and white pollen, white corolla and purple pollen, and white corolla and white pollen. In four generations, 177 self-pollinated individuals of these four phenotypes produced 2123 progeny plants that were classified. Results support the hypothesis that three independent gene pairs were involved in deter- mining the four flower phenotypes. The gene pairs have been designated P/p, W/w, and Pi/pi. It was postulated that all three dominant alleles, P, W, and Pi, must be present to produce both purple corollas and purple pollen. The p allele prevents color development in both corollas and pollen; the w allele eliminates color in corollas but does not affect pollen color; and the pi allele dilutes corolla color from purple to pink and eliminates pollen color. Height measurements of progenies of self-pollinated plants indicated that decreased plant height was associated with inbreeding. On the basis of the evidence presented, the musk thistle plants used in these experiments appear to belong to a single species