85 research outputs found

    Tryptophan and methionine levels in quality protein maize breeding germplasm

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    Because maize (Lea mays L.) is often used either as food for humans or as feed for monogastric animals, essential amino acid levels are important. Maize kernels containing the opaque-2 (o2) mutation have improved amino acid balance and poor agronomic qualities including opaque kernels that are soft and susceptible to mechanical and biological damage. Quality Protein Maize (QPM) developed through plant breeding has improved amino acid balance conferred by the opaque-2 (o2) mutation, but lacks the agronomic deficiencies normally associated with this mutation. To characterize the amino acid balance in QPM breeding germplasm, we determined the levels of nutritionally limiting amino acids tryptophan and methionine. Tryptophan levels were negatively correlated with endosperm translucence, a measure of kernel hardness suggesting the process of selection for hard-kernels reduces tryptophan levels. On average, germplasm containing the o2/ o2 mutation had lower methionine levels than 02/ 02 germ plasm regardless of kernel hardness, suggesting methionine levels could be reduced by the o2/ o2 mutation. A series of inbred lines was test-crossed to the o2/o2 soft endosperm inbred line Tx804. The predictive value of the characteristics of the inbred line for the characteristics of the hybrids was examined. The amino acid levels of the inbred lines were significantly correlated with those of the hybrids, although the predictive value was low (1{2 = 0.13 and 0.27 for methionine and t1yptophan, respectively). The reduction in tryptophan during conversion to the hard-kernel phenotype and the reduction in methionine in o2 germplasm both reduce the nutritional value of QPM. It may be possible to correct these deficiencies by breeding and selection for levels of tryptophan and methionine.This article is published as Scott, M. P., Sandeep Bhatnagar, and Javier Betran. "Tryptophan and methionine levels in quality protein maize breeding germplasm." Maydica 49 (2004): 303-311.</p

    Lattice Boltzmann simulations of lamellar and droplet phases

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    Lattice Boltzmann simulations are used to investigate spinodal decomposition in a two-dimensional binary fluid with equilibrium lamellar and droplet phases. We emphasise the importance of hydrodynamic flow to the phase separation kinetics. For mixtures slightly asymmetric in composition the fluid phase separates into bulk and lamellar phases with the lamellae forming distinctive spiral structures to minimise their elastic energy.Comment: 19 pages, 5 figure

    Design, Performance and Calibration of the CMS Forward Calorimeter Wedges

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    We report on the test beam results and calibration methods using charged particles of the CMS Forward Calorimeter (HF). The HF calorimeter covers a large pseudorapidity region (3\l |\eta| \le 5), and is essential for large number of physics channels with missing transverse energy. It is also expected to play a prominent role in the measurement of forward tagging jets in weak boson fusion channels. The HF calorimeter is based on steel absorber with embedded fused-silica-core optical fibers where Cherenkov radiation forms the basis of signal generation. Thus, the detector is essentially sensitive only to the electromagnetic shower core and is highly non-compensating (e/h \approx 5). This feature is also manifest in narrow and relatively short showers compared to similar calorimeters based on ionization. The choice of fused-silica optical fibers as active material is dictated by its exceptional radiation hardness. The electromagnetic energy resolution is dominated by photoelectron statistics and can be expressed in the customary form as a/\sqrt{E} + b. The stochastic term a is 198% and the constant term b is 9%. The hadronic energy resolution is largely determined by the fluctuations in the neutral pion production in showers, and when it is expressed as in the electromagnetic case, a = 280% and b = 11%

    Investigation of open channel flow with unsubmerged rigid vegetation by the lattice Boltzmann method

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    YesAquatic vegetation can significantly affect flow structure, sediment transport, bed scour and water quality in rivers, lakes, reservoirs and open channels. In this study, the lattice Boltzmann method is applied for performing the two dimensional numerical simulation of the flow structure in a flume with rigid vegetation. A multi-relaxation time model is applied to improve the stability of the numerical scheme for flow with high Reynolds number. The vegetation induced drag force is added in lattice Boltzmann equation model with the algorithm of multi-relaxation time in order to improve the simulation accuracy,. Numerical simulations are performed for a wide range of flow and vegetation conditions and are validated by comparing with the laboratory experiments. Analysis of the simulated and experimentally measured flow field shows that the numerical simulation can satisfactorily reproduce the laboratory experiments, indicating that the proposed lattice Boltzmann model has high accuracy for simulating flow-vegetation interaction in open channel.National Natural Science Foundation of China (grant number: 11861003 and 11761005

    The Thickness of Anodic Films on Aluminium

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    The thickness of the anodic film produced on aluminum in anodizing is intimately connected with some of the most important properties of the films such as corrosion resistance absorptive power insulation resistance etc.And is therefore of great interest (1,2). Napier and Westwood(3)have determined thicknesses of Adonic films obtained on anodizing in sulphuric acid baths of various strengths and at several temperatures .these Experiments were conducted at constant current and therefore the results are of little practical importance since all the commercial processes are conducted at constant voltage and not at constant current. Bradshaw and Clarke (4)Have collected similar data at constant voltage but their work was limited to the investigation of a sulphuric acid electrolyte of 20% -vol .concentration.In view of the non –availability of explicit Information about the conditions of anodizing in sulphuric acid which would yield films of maximum thickness, the present investigation was undertaken

    Recovery of Metallic Zinc from Blowings and Utilisation of Zinc Skimmings

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    The galvanizing industry is the major consumer of virgin zinc produced in the world and nearly half of the primary zinc is consumed for galvanizing alone. Till recently the entire zinc demand of the country was met solely by imports involving a huge drain of foreign exchange. About 40,000 to 50,000 tonnes of virgin zinc is consumed every year in the country by the galvanizing industry alone. The anticipated future demand for zinc the country is comparatively high in relation to the expected production that may be achieved by the zinc smelters under installation
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