Papers by Keyword: K

Abstract: Nanoparticle has been used in agricultural practices such as soil ameliorant. Nanoparticle of volcanic ash and biofertilizer were applied to improve some soil characteristics of Inceptisols. The objective of this research was to optimize the benefit of nanoparticle of volcanic ash and biofertilizer in reducing soil acidity, increasing organic carbon content, and increasing basic cations of Inceptisols. Volcanic ash was obtained from the eruption of Mt. Merapi in Central Java. Nanoparticle was grinded in Nanotechnology and Graphene Research Center, Universitas Padjadjaran. Phosphate solubilizing fungi was used as biofertilizer, isolated in Soil Microbiology Laboratory, Universitas Padjadjaran. A two factors randomized experimental design was used in this research. Nanoparticle of volcanic ash was used as first factor (four levels: 0%, 2%, 4% and 6% of soil weight percentages). Biofertilizer was used as second factor (two levels: 0 and 10 g.kg^-1). These two treatments were combined and mixed evenly and incubated for three months in field condition. Every month during those three months a few soil samples were taken to analyze the change of soil characteristics. The results showed that the treatments increased organic carbon content and potassium basic cation but had no effect to soil acidity.

Abstract: This paper calculated THI and K with GIS technology, and analyzed the tourism climate comfort level of East China based on the monthly average meteorological data of 30 years from 132 whether stations in East China. Results show that THI of East China decrease gradually from south to north, from low altitude to high altitude. The annual period of comfortable climate is longer when analyzed in terms of K rather than THI. The tourism climate comfortable period of East China shows significant regional difference, the maximum value distributed around Fujian province, and the minimum value distributed around Tai Mount in Shandong province. The predominant length of climate comfortable period in China is 5 months per year, while areas that have climate comfortable period for 10 months are most limited.

Abstract: In this study, the input and output parameters of potassium (K) for wheat season were collected from 2000 to 2011 to evaluate the nutrient cycling and balance in North Central China, the Middle and Lower Reaches of the Yangtze River and Northwest China. The results showed that the K fertilizer application rates for each region were 74.7, 102.9 and 50.6 kg K/ha, the K brought from previous crop were 99.5, 19.8 and 23.4 kg K/ha, and brought from seeding were 1.0, 0.8 and 0.7 kg K/ha, respectively. The K input from atmospheric deposition and irrigation were all considered zero. The K uptake by harvest in above-ground plant in North Central China, the Middle and Lower Reaches of the Yangtze River and Northwest China were 131.8, 159.9 and 119.8 kg K/ha. As a result, The K balance in North Central China showed surplus by 43.6 kg/ha, while in the Middle and Lower Reaches of the Yangtze River and Northwest China, the K balance were both deficiency by 36.4 and 45.1 kg/ha, even though it did not affect the crop yield. While it is suggested that we need to adjust the K fertilizer application in a long term, in order to maintain the sustainable soil fertility.

Abstract: The topographic correction of remote sensing images is an important factor to improve the precision of quantitative remote sensing data processing. In the existing topographic correction models,the Minnaert model is the only model based on the assumption of non-Lambertian.the Minnaert coefficient K is an effective factor for the correction results. To improve the correction accuracy,we correct the image in accordance with the slope grading idea to select different areas from the image, then use different k values in different slope regions.In this paper, the topography correction is efficiently corrected by SCS model, Minnaert model and improved Minnaert model, based on HJCCD image and the corresponding DEM in Heihe . The results showed that the improved Minnaert model can eliminate the effect of topography better than other methods and can be widely used.

Abstract: The CuZnFeZrO₂ catalysts were synthesized by co-precipitation method.,and then used to synthesize different content of K₂O modified CuZnFeZrO₂ catalysts by deposition-precipitation method.Hydrogenation of CO₂ to higher alcohols over (K₂O)_x/CuZnFeZrO₂ catalysts were investigated at 523 K,3.0 MPa and 3000 h^-1.These catalysts were characterized by X-ray diffraction (XRD),temperature programmed reduction of H₂ (H₂-TPR),and temperature-programmed desorption of CO₂ (CO₂-TPD).The results showed the addition of an appropriate amount of Potassium to the CuZnZrO₂ catalysts improved catalytic activity ,the space time yield (STY) and C²⁺OH selectivity. When the Fe content is 5% best, at this time the space time yield of selectivity and alcohol of C²⁺ alcohol reaches the maximum value, this time space and time conversion rate is 0.32g/ml·h.

Abstract: Stress intensity factor (K) is the measure of severity of stress at the crack tip. When K exceeds the critical limit (i.e., the material fracture toughness), the crack grows. K is valid in brittle materials (LEFM) and to some extent in ductile materials also provided there is small scale yielding (SSY) at the crack tip. The paper reviews the numerical methodology to obtain KI of ductile, Mode I cracked, CT and SENB test specimens in LEFM and SSY regimes with the help of J integral method. The numerical values are successfully compared with the theoretical values.

Abstract: A series of coke samples with loading alkali and alkaline earth metals were prepared by the impregnation method, the NOx emission were investigated in a silica fixed bed reactor in the combustion process of raw coke and coke modified by Na, K, Ca and Mg. The results show that Na, K, Ca and Mg play in-situ catalytic effects on the NOx reduction reactions. When the loading amount of Na2CO3 is 2.0%, the NOx reduction ratio was around 17.4%, when the loading of K2CO3 is 2.0%, the amount of NOx emission is reduced by 26.5%. When the loading of CaCl2 is 2.0%, the amount of NOx emission is reduced by 22.3%. When the loading of MgCl2 is 2.0%, the NOx reduction ratio is about 10.9%.

Abstract: the paper relates a study in developing a quantitative elemental analysis for clay minerals by the EDXRF technique. Elements of interest are Al, Si, K, Ca, Ti and Fe. The regression method involved development of calibration graphs of each of these elements using six different clay minerals reference standards. straight lines were obtained from these calibration graphs with r2 values ranging from 0.923 to 0.997. The accuracy of this regression method was then tested by comparing the quantitative analysis result obtained from fundamental parameter method using argillaceous limestone reference standard as the sample. Fundamental parameter method gives a more accurate result than that of the regression method.