Land-use land-cover classification analysis of Giba catchment using hyper temporal MODIS NDVI satellite images

Landsat-based land-use land-cover (LULC) mapping studies were previously conducted in Giba catchment, comprising an area of 4019 km². No attempt has been done to map LULC of this catchment through the analysis of Moderate Resolution Imaging Spectroradiometer (MODIS) normalized difference vegetation index (NDVI) time-series data. This article is aimed to see whether time-series MODIS NDVI data set is applicable for LULC mapping of Giba catchment or not. MODIS NDVI data sets of the year 2010 were used for classification analysis. The original data were subjected to MODIS Reproduction Tool and stacking. The re-projected and stacked images were filtered using Harmonic Analysis of Time-Series filtering algorism to remove the effects of cloud and other noises. The MODIS NDVI data sets (16-day maximum value composite) were classified using the ISODATA clustering algorithm available under ERDAS IMAGINE software. A series of unsupervised classification runs were carried out with a pre-defined number of classes (5–24). From this classification, the optimal numbers of classes were determined to be eight after checking for average divergence analysis. The classification result became eight LULC classes namely: bare land, grass land, irrigated land, cultivated land, area closure, shrub land, bush land, and forest land with an overall accuracy of 87.7%. It was therefore concluded that MODIS NDVI time-series image is applicable for mapping large watersheds.     

Parameter Variation and Part-Load Efficiencies of Wave Energy Conversion

There are growing provisions to include ocean wave energy as an alternate renewable energy source. There are also several challenges that need to be addressed before the technology gains full engineering and market confidence. One of the main technical hurdles is the need to address part-load problems of wave energy converters resulting from bathymetric conditions and variations in wave parameters such as wave frequency and height. As such, the wave phenomenon is inherently variable in time and space. This is compounded by the fact that wave energy conversion devices are less efficient at part load. This paper discusses sources of part loads in wave energy conversion including their impact on system efficiency for a California weather scenario, also relating wave energy conversion techniques to part-load efficiencies.     

Enhanced Sintering of Yttrium-Doped Barium Zirconate by Addition of ZnO

The influence of transition metal oxides additives, especially zinc oxide, on the densification and electrical properties of doped barium zirconate have been examined. With the use of zinc oxide as a sintering aid, BaZr_0.85Y_0.15O_3–δ was readily sintered to above 93% of theoretical density at 1300°C. Scanning electron microscopic investigations showed Zn accumulation in the intergranular regions. Thermogravimetric analysis of the material under flowing CO₂ showed ZnO-modified barium zirconate to exhibit excellent chemical stability. The conductivity, as measured by A.C. impedance spectroscopy under H₂O saturated nitrogen, was slightly lower than that of unmodified barium zirconate. Electromotive force measurements under fuel cell conditions revealed the total ionic transport number to be ∼0.9 at 600°C. The combination of electrical and chemical properties and good sinterability render ZnO-modified barium zirconate an excellent candidate for reduced temperature solid oxide fuel cell applications.     

Improving time-domain measurements with a network analyzer using arobust rational interpolation technique

A method to efficiently and accurately compute a time-domain waveform from a network-analyzer frequency-domain measurement is presented in this paper. The method is based on a robust interpolation technique to construct a pole-residue representation of the response of the device-under-test. First, the rational function is expressed in terms of Chebyshev polynomials, instead of the usual power series, to accurately determine the poles of the network over a wide frequency range. The properties of a passive system are then utilized to efficiently calculate the residues. The resulting pole-residue model is analytically transformed to obtain the time-domain response in any time window, beyond the limitations of the discrete Fourier transform (DFT) technique. Unlike the DFT technique, the method does not require a large number of equally spaced harmonically related frequency points. The parametric model can also be used to economically store large measurement data. The proposed procedure is computationally inexpensive and less sensitive to numerical instability. To illustrate the validity of the method, examples of frequency- and time-domain measurements of a Beatty structure and simulation data of a low-pass Butterworth filter are given     

壳聚糖固定化单宁酶及其澄清绿茶汤的应用研究

以固定化单宁酶的酶活和活力回收为指标,筛选出壳聚糖海绵载体固定化单宁酶。与游离酶相比,固定化酶的最适反应pH向酸性偏移0.5,最适反应温度提高5℃;对金属离子和EDTA的稳定性均增强。固定化酶的半衰期也明显延长,4℃时半衰期由35.39h延长至324.25h,25℃时半衰期仍高达189.56h。分别以没食子酸甲酯溶液和绿茶汤为底物,经连续6批次酶促反应,固定化单宁酶的酶活保持稳定。经固定化单宁酶处理后,绿茶汤澄清度、贮存稳定性明显提高。     

催化式红外干法杀青同步脱水对叶菜干燥影响的研究

脱水蔬菜加工需要杀青和干燥2个阶段,传统加工方法存在耗水量大、能耗高、产品品质差、污染重等缺点。采用催化式红外干法杀青同步脱水技术,对叶菜类蔬菜(大葱、香葱、紫甘蓝、韭菜、生菜)进行加工处理,分别对蔬菜POD酶活酶钝化情况、水分去除情况和干燥速率情况进行研究;对蔬菜维生素C保留率和颜色等质量指标进行考察。研究表明:5种叶菜类蔬菜经过催化式红外杀青处理后POD酶活残留率稳定在20%左右,达到了预期效果;蔬菜杀青灭酶的同时,去除部分水分,起到干燥的作用;得到不同蔬菜催化式红外最佳杀青工艺条件,在此条件下得到杀青产品质量高。     

樟芝深层液体发酵条件的试验研究

目的 研究提高樟芝菌丝体干重和胞内外多糖产量的方法 .方法 用二次通用旋转组合设计法,研究樟芝液体发酵条件中的温度、转速和接种量对菌丝体干重和胞内外多糖产量的影响.结果 与结论 胞内多糖总产量的最优参数组合为温度27℃、转速113 r/min、接种量21%;胞外多糖产量的最优参数组合为温度27℃、转速120 r/min,接种量22%,并通过试验验证了最优组合.     

Effects of close-up dietary energy level and supplementing rumen-protected lysine on energy metabolites and milk production in transition cows

The objective of this study was to investigate the effects of dietary energy levels and rumen-protected lysine supplementation on serum free fatty acid levels, β-hydroxybutyrate levels, dry matter (DM) intake, and milk production and composition. Treatments were arranged in a 2 × 2 factorial design with 2 dietary energy levels [high net energy for lactation (NE_L) = 1.53 Mcal/kg of DM vs. low NE_L = 1.37 Mcal/kg of DM; HE vs. LE) fed either with rumen-protected lysine (bypass lysine; 40 g/cow per day) or without rumen-protected lysine (control). Sixty-eight third-lactation Holstein dairy cows entering their fourth lactation were randomly allocated to 4 treatments groups: HE with bypass lysine, HE without bypass lysine, LE with bypass lysine, and LE without bypass lysine. Groups were balanced based upon their expected calving date, previous milk yields, and body condition score. All cows were fed the same diet (NE_L = 1.34 Mcal/kg of DM) during the dry period prior to the trial. Rumen-protected lysine was top-dressed on a total mixed ration to deliver 9.68 g/d of metabolizable lysine to pre- and postpartum cows. After calving, all cows received the same TMR (1.69 Mcal/kg of DM). Blood samples were collected at ?21, ?14, ?7, 0, 3, 7, 14, and 21 d relative to calving, and free fatty acids and β-hydroxybutyrate concentrations were measured. Amount of feed offered and orts were collected and measured for individual cows 4 d/wk. Milk samples were collected once per week following calving, and milk composition was analyzed. Feeding high NE_L to close-up cows decreased the concentrations of free fatty acid and β-hydroxybutyrate in prepartum cows but not in postpartum cows. Addition of rumen-protected lysine increased postpartum DM intake, and decreased serum free fatty acid and β-hydroxybutyrate concentrations. Neither energy nor rumen-protected lysine supplementation nor their interaction affected milk yield or fat or lactose yields. However, cows in the group receiving HE with bypass lysine tended to produce more milk compared with other groups and had a lower blood β-hydroxybutyrate concentration postpartum. These results indicate that feeding a high-energy diet together with rumen-protected lysine improved DM intake and lowered serum free fatty acid and β-hydroxybutyrate concentrations in transition cows.     

Optimization on the Conversion of Bamboo Shoot Shell to Levulinic Acid with Environmentally Benign Acidic Ionic Liquid and Response Surface Analysis

Levulinic acid (LA) has been identified as a promising green, biomass derived platform chemical. Response surface analysis (RSA) with a four-factor-five-level central composite design (CCD) was applied to optimize the hydrolysis conditions for the conversion of bamboo (Phyllostachys Praecox f. preveynalis) shoot shell (BSS) to LA catalyzed with ionic liquid [C₄mim]HSO₄. The effects of four main reaction parameters including temperature, time,C_[C4mim]HSO4(initial [C₄mim]HSO₄ concentration) and X_BSS (initial BSS intake) on the hydrolysis reaction for yield of LA were analyzed. A quadratic equation model for yield of LA was established and fitted to the data with an R² of 0.9868, and effects of main factors and their corresponding relationships were obtained with RSA. Model validation and results of CCD showed good correspondence between actual and predicted values. The analysis of variance (ANOVA) of the results indicated that the yield of LA in the range studied was significantly (P<0.05) affected by the four factors. The optimized reaction conditions were as follows: temperature of 145 ℃, time of 103.8 min,C_[C4mim]HSO4 of 0.9 mol·L^-1 and X_BSS of 2.04% (by mass), respectively. A high yield [(71±0.41)% (by mol), triplicate experiment] was obtained at the optimum conditions of temperature of 145 ℃, time of 104 min,C_[C4mim]HSO4 of 0.9 mol·L^-1 and X_BSS of 2% (by mass), which obtained from the real experiments, concurred with the model prediction [73.8% (by mol) based on available C₆ sugars in BSS or 17.9% (by mass) based on the mass of BSS], indicating that the model was adequate for the hydrolysis process.