Effect of Three Types of Organic Manures on the Grain Yield of Wheat in Khashm Elgirba Soil Series, Sudan

This study was conducted during seasons 1998/1999 and 1999/2000 at a farm adjacent to New Halfa town to assess the effect of farm yard manure (FYM), filtermud (FM) and bagasse (B) on yield of wheat. Each manure was applied to soil surface at a rate of    0, 15, 30, 45, 60 and 75 t ha-1 in a randomized complete block design (RCBD) with four  replications. Each manure was incorporated into the soil using hand tools. The results of nitrogen (N) and phosphorus (P) uptake (kg ha-l( revealed that wheat plants withdrew higher amounts of N from the soil treated with FYM as compared to those treated with either FM of B. The amounts of P withdrawn by the wheat plants from the soil treated by the three sources of organic manures at all levels of application were very low and ranged from 1.85 to 6.67 kg P ha-l. The present study also showed that increasing rates of application of each of the tested manures resulted in highly significant increases in grain yield. These organic manures can be ranked according to their effectiveness in increasing the yield of wheat as follows: FYM > FM>B. The economic evaluation of the study indicated that only the lowest level of application (15 t ha-l) of FYM and FM gave positive net benefits albeit lower than those reported for the control. However, net losses from the higher rates of application of each of F YM and FM and of all rates of the B were obtained. This was presumably due to high cost of both transportation and application of these bulky organic manures

Effect of Three Organic Manures on some Physical and Chemical Properties of Khashm Elgirba Soil Series

The effect of farmyard manure (FYM), filtermud (FM), and bagasse on some physical and chemical properties of Khashm Elgirda soil series was studied in 1999-2000. Each of the organic manures was applied at a rate of 0,15,30,45,60, and 75 t ha-1 in a RCBD with four replications. The organic manures were incorporated into the soil using hand tools. The study showed that increasing the rate of each of the applied manures resulted in a highly significant reduction in the soil bulk density and consequently a highly significant increase in both total soil porosity and soil moisture. Bagasse was the most effective in reducing the soil bulk density followed by FYM and lastly FM. The study also indicated that increasing rates of application of each of the tested manures resulted in small increments of both exchangeable potassium and organic carbon. However, the investigation did not show any noticeable increase in total soil nitrogen

Some Physical and Chemical Characteristics of some "gardud" Soils in the State pf North Kordofan, Sudan

    Four locations south of Elobied town in the State of North Kordofan were selected to represent three "gardud" soils in May-June 1996. These locations were Aradayia, Umood, Bangadeed and Kaba. The results of the study showed that the soils are genetically young and are, therefore classified as Entisols and Inceptisols. The soil at Kaba is coarse loamy and those at Umood, Aradayia and Bangadeed are fine loamy. Kaolinite is the dominant clay type of the soil at Kaba, whereas smectites dominate the other three soils. The soil at Kaba is conceived to be formed in situ from sandstone as substantiated by grain-size. distribution, while the other three soils are of alluvial origin. The compactness of the soils at Aradayia, Umood, and Bangadeed is seen as a result of cementation of coarse soil separates by smectitic clays, whereas that of the soil at Kaba is envisaged as cementation by iron oxides. The soils at Aradayia, Umood, and Bangadeed are moderately fertile, whereas that at Kaba is infertile. The former three soils can be utilized under judicious cultural practices that increase soil permeability for rain water, lessen erosion hazard, and conserve soil moisture, in addition to rational application of nitrogen fertilizers. The "gardud" soils at Aradayia, Umood and Bangadeed have promising potential for field crops suited to the prevalent climate in the area, whereas the "gardud" soil at Kaba is best suited for natural grazing and tree crops, i.e., Acacia senegal (Hashab)

Pengaruh Struktur Kepemilikan, Struktur Modal, Profitabilitas dan Pertumbuhan Perusahaan terhadap Nilai Perusahaan

Tujuan dari penelitian adalah untuk menguji pengaruh struktur kepemilikan, struktur modal, profitabilitas dan pertumbuhan Perusahaan terhadap nilai Perusahaan yang diukur dengan kepemilikan manajerial, kepemilikan institusional, debt to equity ratio, return on equity dan pertumbuhan laba. Populasi penelitian ini adalah Perusahaan Consumer Goods Industry dan Miscellaneous Industry yang terdaftar di Bursa Efek Indonesia (BEI) periode 2009-2013. Total sampel penelitian berjumlah 9 Perusahaan yang ditentukan melalui purposive sampling. Hasil analisis menunjukkan bahwa kepemilikan manajerial berpengaruh tidak signifikan terhadap nilai Perusahaan dengan nilai t-hitung sebesar 0,922 dan nilai signifikan sebesar 0,362, kepemilikan institusional berpengaruh signifikan terhadap nilai Perusahaan dengan nilai t-hitung sebesar 2,097 dan nilai signifikan sebesar 0,043, debt to equity ratio berpengaruh tidak signifikan dengan nilai t-hitung sebesar -1,583 dan nilai signifikan sebesar 0,122, return on equity berpengaruh signifikan terhadap nilai Perusahaan dengan nilai t-hitung sebesar 7,061 dan nilai signifikan sebesar 0,000 dan pertumbuhan laba berpengaruh signifikan terhadap nilai Perusahaan dengan nilai t-hitung sebesar -2,257 dan nilai signifikan sebesar 0,030. Hasil analisis uji F menunjukkan bahwa kepemilikan manajerial, kepemilikan institusional, debt to equity ratio, return on equity dan pertumbuhan laba secara simultan berpengaruh signifikan terhadap nilai Perusahaan dengan nilai F- hitung sebesar 12,207 dan nilai signifikan sebesar 0,000

Multiplicity at the Stellar/Substellar Boundary in Upper Scorpius

We present the results of a high-resolution imaging survey of 12 brown dwarfs and very low mass stars in the closest (~145 pc) young (~5 Myr) OB association, Upper Scorpius. We obtained images with the Advanced Camera for Surveys/High Resolution Camera on HST through the F555W (V), F775W (i'), and F850LP (z') filters. This survey discovered three new binary systems, including one marginally resolved pair with a projected separation of only 4.9 AU, resulting in an observed binary fraction of 25+/-14% at separations >4 AU. After correcting for detection biases assuming a uniform distribution of mass ratios for q>0.6, the estimated binary fraction is 33+/-17%. The binary fraction is consistent with that inferred for higher-mass stars in Upper Sco, but the separation and mass ratio distributions appear to be different. All three low-mass binary systems in Upper Sco are tight (<18 AU) and of similar mass (q>0.6), consistent with expectations based on previous multiplicity studies of brown dwarfs and very low mass stars in the field and in open clusters. The implication is that the distinct separation and mass ratio distributions of low-mass systems are set in the formation process or at very young ages, rather than by dynamical disruption of wide systems at ages >5 Myr. Finally, we combine the survey detection limits with the models of Burrows et al. (1997) to show that there are no planets or very low-mass brown dwarfs with masses >10 M_J at projected separations >20 AU, or masses >5 M_J at projected separations >40 AU orbiting any of the low-mass (0.04-0.10 M_sun) objects in our sample.Comment: Accepted for publication in ApJ; 10 pages, 4 figures in emulateapj forma

Modeling the Formation of Clouds in Brown Dwarf Atmospheres

Because the opacity of clouds in substellar mass object (SMO) atmospheres depends on the composition and distribution of particle sizes within the cloud, a credible cloud model is essential for accurately modeling SMO spectra and colors. We present a one--dimensional model of cloud particle formation and subsequent growth based on a consideration of basic cloud microphysics. We apply this microphysical cloud model to a set of synthetic brown dwarf atmospheres spanning a broad range of surface gravities and effective temperatures (g_surf = 1.78 * 10^3 -- 3 * 10^5 cm/s^2 and T_eff = 600 -- 1600 K) to obtain plausible particle sizes for several abundant species (Fe, Mg2SiO4, and Ca2Al2SiO7). At the base of the clouds, where the particles are largest, the particle sizes thus computed range from ~5 microns to over 300 microns in radius over the full range of atmospheric conditions considered. We show that average particle sizes decrease significantly with increasing brown dwarf surface gravity. We also find that brown dwarfs with higher effective temperatures have characteristically larger cloud particles than those with lower effective temperatures. We therefore conclude that it is unrealistic when modeling SMO spectra to apply a single particle size distribution to the entire class of objects.Comment: 25 pages; 8 figures. We have added considerable detail describing the physics of the cloud model. We have also added discussions of the issues of rainout and the self-consistent coupling of clouds with brown dwarf atmospheric models. We have updated figures 1, 3, and 4 with new vertical axis labels and new particle sizes for forsterite and gehlenite. Accepted to the Astrophysical Journal, Dec. 2, 200

Analysis and design of a modular multilevel converter with trapezoidal modulation for medium and high voltage DC-DC transformers

Conventional dual active bridge topologies provide galvanic isolation and soft-switching over a reasonable operating range without dedicated resonant circuits. However, scaling the two-level dual active bridge to higher dc voltage levels is impeded by several challenges among which the high dv/dt stress on the coupling transformer insulation. Gating and thermal characteristics of series switch arrays add to the limitations. To avoid the use of standard bulky modular multilevel bridges, this paper analyzes an alternative modulation technique where staircase approximated trapezoidal voltage waveforms are produced; thus alleviating developed dv/dt stresses. Modular design is realized by the utilization of half-bridge chopper cells. Therefore, the analyzed converter is a modular multi-level converter operated in a new mode with no common-mode dc arm currents as well as reduced capacitor size, hence reduced cell footprint. Suitable switching patterns are developed and various design and operation aspects are studied. Soft switching characteristics will be shown to be comparable to those of the two-level dual active bridge. Experimental results from a scaled test rig validate the presented concept

The Pure Spinor Formulation of Superstrings

In this lectures we outline the construction of pure spinor superstrings. We consider both the open and closed pure spinor superstrings in critical and noncritical dimensions and on flat and curved target spaces with RR flux. We exhibit the integrability properties of pure spinor superstrings on curved backgrounds with RR fluxes.Comment: These lectures have been given in the RTN Winter School on Strings, Supergravity and Gauge Theories, CERN (2008). 32 pages, a typo correcte