4,401 research outputs found

    Can potassium fertilization, soil amendments and land leveling ameliorate rice production under salt affected soils conditions?

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    The significance of nutrient and water and its sustainability was and still one of the most emerging issues in agriculture. Therefore, it should be considered the maintenance, improvement and efficiently utilization of nutrient and water resources. In present work, the effect of land leveling, soil amendments including gypsum and/or compost application and K- fertilizer on rice production under salt affected soils conditions have been studied. The results showed that the highest yield of grain and straw of rice was obtained with using K-fertilization, land levelling rate 0.05 % of surface slope in the presence of gypsum plus compost application. Furthermore, this study suggests that, the efficiency of irrigation application increased from about 60 (for control) to 65 and 78 % for land leveling with 0.0 and 0.05 % slope, respectively. That means, the water loss rate from irrigation were 43, 36 and 32 %, respectively using the previous land leveling treatments. Thus, about 17 % from the applied water for irrigation could be saved under 0.05 % slope. On the other hand, the highest decrease rate in soil salinity (EC, dS m-1) and alkalinity (sodium absorption ratio, SAR) was 26 and 20 %, respectively for the traditional land leveling or the farmers’ practices. Therefore, sustainable rice crop production should be managed to overcome the soil salinity and alkalinity under low land rice cultivation, improving soil quality and its fertility

    Dirhenium Carbonyl Complexes Bearing 2-Vinylpyridine, Morpholine and 1-Methylimidazole Ligands

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    Treatment of the labile compound [Re2(CO)8(MeCN)2] with 2-vinylpyridine in refluxing benzene affords exclusively the new compound [Re2(CO)8(μ-η1:η2-NC5H4CHCH2)] (1) in 39% yield in which the μ-η1:η2-vinylpyridine ligand is coordinated to one Re atom through the nitrogen and to the other Re atom via the olefinic double bond. Reaction of [Re2(CO)8(MeCN)2] with morpholine in refluxing benzene furnishes two compounds, [Re2(CO)9(η1-NC4H9O)] (2) and [Re2(CO)8(η1-NC4H9O)2] (3) in 5% and 29% yields, respectively. Reaction of [Re2(CO)8(MeCN)2] with 1-methylimidazole gives [Re2(CO)8{η1-NC3H3N(CH3)}2] (4) and the mononuclear compound fac-[ReCl(CO)3{η1-NC3H3N(CH3)}2] (5) in 18% and 26% yields, respectively. In the disubstituted compounds 2 and 4, the heterocyclic ligands occupy equatorial coordination sites. The mononuclear compound 5 consists of three CO groups, two N coordinated η1-1-methylimidazole ligands and a terminal Cl ligand. The XRD structures of complexes 1, 3 and 5 are reported

    Reactivity of [Re\u3csub\u3e2\u3c/sub\u3e(CO)\u3csub\u3e8\u3c/sub\u3e(MeCN)\u3csub\u3e2\u3c/sub\u3e] with Thiazoles: Hydrido Bridged Dirhenium Compounds Bearing Thiazoles in Different Coordination Modes

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    Reactions of the labile compound [Re2(CO)8(MeCN)2] with thiazole and 4-methylthiazole in refluxing benzene afforded the new compounds [Re2(CO)7{μ-2,3-η2-C3H(R)NS}{η1-NC3H2(4-R)S}(μ-H)] (1, R = H; 2, R = CH3), [Re2(CO)6{μ-2,3-η2-C3H(R)NS}{η1-NC3H2(4-R)S}2(μ-H)] (3, R = H; 4, R = CH3) and fac-[Re(CO)3(Cl){η1-NC3H2(4-R)S}2] (5, R = H; 6, R = CH3). Compounds 1 and 2 contain two rhenium atoms, one bridging thiazolide ligand, coordinated through the C(2) and N atoms and a η1-thiazole ligand coordinated through the nitrogen atom to the same Re as the thiazolide nitrogen. Compounds 3 and 4 contain a Re2(CO)6 group with one bridging thiazolide ligand coordinated through the C(2) and N atoms and two N-coordinated η1-thiazole ligands, each coordinated to one Re atom. A hydride ligand, formed by oxidative-addition of C(2)–H bond of the ligand, bridges Re–Re bond opposite the thiazolide ligand in compounds 1–4. Compound 5 contains a single rhenium atom with three carbonyl ligands, two N-coordinated η1-thiazole ligands and a terminal Cl ligand. Treatment of both 1 and 2 with 5 equiv. of thiazole and 4-methylthiazole in the presence of Me3NO in refluxing benzene afforded 3 and 4, respectively. Further activation of the coordinated η1-thiazole ligands in 1–4 is, however, unsuccessful and results only nonspecific decomposition. The single-crystal XRD structures of 1–5 are reported

    Enhancing nucleation density and adhesion of polycrystalline diamond films deposited by HFCVD using surface treaments on Co cemented tungsten carbide

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    The deposition of diamond films by chemical vapour deposition onto tungsten carbide is an attractive proposition since it can lead to improvements in the life and performance of cutting tools. However, deposition of diamond onto cemented tungsten carbide (WC-Co) dental burs and inserts are problematic due to the cobalt binder in the WC that provides additional toughness to the tool but it causes poor adhesion and low nucleation density. A number of surface treatments can be used to overcome these problems including chemical etching, ion implanting, interlayer coating and bias treatment. Negative biasing of the substrate is attractive because it can be controlled precisely; it is carried out in-situ, gives good homogeneity and results in improved adhesion. On flat substrates, such as copper and silicon, biasing has been shown to give better adhesion, improved crystallinity and smooth surface. In this study, we have used a modified hot filament chemical vapour deposition (HFCVD) system to coat complex shaped tools such as dental burs with polycrystalline diamond films, which have good adhesion and crystallinity. By applying a negative bias to the substrate, we show that the nucleation density, adhesion and surface properties can be improved. The effects of various process parameters such as bias time, emission current, bias voltage and the filament arrangement on the film properties are reported. For machining applications CVD diamond coatings must be hard, wear resistance and having a good quality film

    Effect of Magnetic Water and Phosphorus Rates on Some Nutrients Uptake by Summer Squash Grown In Calcareous Soil of Duhok Governorate.

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    This study was conducted at the college of Agriculture/ Duhok University during August-November 2009, to study the effect of magnetic water treatment and phosphorus fertilizer rates (P0= 0, P1= 90, P2 = 180, P3 = 270) kg P2O5 ha-1 and their interactions on some nutrient uptake by summer squash plant in addition to their effect on some chemical properties soil at (0-15 and 15-30 cm) depth. Mulla-Ahmed seeds were sown in ridges 0.5 m apart. Half of the treatments were irrigated with well water and the other half with the same water after magnetization. The results indicated that magnetic water significantly increased dry weight of plants and also had significant effect on uptake of nutrients by plant and soil nutrients and they were significantly higher at 0-15 cm. An interaction of P3 x MW gave best uptake values by plant for most nutrients, higher concentration of calcium, magnesium, total nitrogen and phosphorus in the soil

    EFFECT OF POWER ON HOLE QUALITY OF UNDERWATER GLASS DRILLING USING CO2 LASER

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    The aim of this paper to study the effect of power on the drilling of soda lima glass (SLG) using under water laser drilling technique. A 1.15 mm thickness SLG sheets were immersed 1mm below the water surface, then irradiated with CW CO2 laser. The laser parameters used were (24, 25 and 26) W power, (5, 7.5 and 10) sec and exposure time and (1, 2and 3) pulses. Were determined using images for samples and study quality of holes using images. These ones of the dimensional of hole and crack length measured by image j program of the samples, it was watched that hole diameter and the length of cracks could be regulated by the power, time and no. of pulses. When power or pulses were increased, the hole diameter increased. The length of cracks decreased with increased no. of pulses and increased when the power increased. The small hole was 0.469mm found at working power (24) W, five seconds and one pulse for hole diameter. While, the minimum crack length was 0.4mm found at three pulse, five sec. and 24 W power. In addition, the parameters were analyzed statistically using design of expert software, Box Behnken design from surface response methodology and the results were significant

    High performance supercapacitor based on laser induced graphene for wearable devices

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    To ensure maximum comfort for the wearer, electronic components that include energy harvesters need to be mechanically conformable. In this context, we demonstrate a versatile, cost-effective and efficient method for fabricating graphene supercapacitor electrodes using Laser Induced Graphene (LIG). A CO2 laser beam instantly transforms the irradiated polyethersulfone polymer (PES) into a highly porous carbon structure. The LIG method was used to deposit graphene layers on graphite sheets to produce the supercapacitor electrodes. Graphene formation and morphology were examined and confirmed using several techniques including Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX) spectroscopy, Raman Spectroscopy and Fourier transform infrared spectroscopy (FTIR). Moreover, the electrochemical characterization was performed in different electrolytes (NaOH and KOH). At 5 mV s-1, the LIG electrode achieved 165 mF cm-2 and 250 mF cm-2 in NaOH and KOH electrolytes, respectively. Consequently, we show that a wearable symmetric supercapacitor device with LIG electrodes achieved 98.5 mF cm-2 at 5 mV s-1 in KOH electrolyte. The device demonstrated an energy density of 11.3 μWh.cm-2 with power density of 0.33 mWcm-2 at 0.5 mA cm-2. The retention of capacitance was 75% after 2000 cycles, with outstanding performance for the comparable graphene-based electrodes. These results further validate the use of LIG for developing flexible energy harvesters for wearable applications
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