A commercial cellulase preparation (Viscozyme Cassava C) was employed to process wheat bran to improve the ratio of insoluble to soluble dietary fibre. The effects of initial moisture content, enzyme dosage, and incubation time on the content of soluble and insoluble fibre during the enzymatic treatment were investigated. The appropriate conditions for the cellulase treatment were initial moisture content of 0.75 g water g−1 dry matter, enzyme dosage of 9 U g−1 dry matter and incubation time of 120 min under which the ratio of insoluble to soluble fibre of wheat bran was lowered by 42%. Untreated and cellulase-treated wheat bran was incorporated into cookies at levels of 0%, 20%, 30%, 40% and 50%. Cookie with 50% cellulase-treated bran showed 21% lower ratio of insoluble to soluble fibre as well as 14% lower hardness and 13% higher overall acceptability than sample with the same amount of untreated bran. 相似文献
The potential of cellulose from sugarcane bagasse used for pork sausage was investigated. The purity level of cellulose fibre from sugarcane bagasse and the functional characteristics in pork sausage were studied. The differences in the sugarcane fibre and sausage characteristics were strongly related to the cellulose/lignin content of the extracted cellulose under different amounts of bleaching. Bleached sugarcane fibres showed better water (3.55) and oil (2.34) holding capacity in comparison with untreated fibre (2.92 and 2.38, respectively). The sugarcane fibres in each treatment stage showed different effects on sausage properties. Sausages with 1% cellulose fibres added had an improved texture profile, but the addition of 3% cellulose fibres to sausages resulted in a higher cooking yield. Consumers considered the sensory characteristics of all sausages as acceptable. These results indicated that low levels of cellulose extracted from sugarcane bagasse could be added and maintain the inherent characteristics of meat products. 相似文献
Weakly consolidated reservoirs are prone to sand production problem,which can lead to equipment damages and environmental issues.The conditions for sand production depend on stresses and properties of rock and fluid.Accurate sand volume estimation is,however,still a challenging issue,especially for reservoirs in weak formations.The weak reservoirs containing viscous or heavy oil are mainly discovered in shallow depths in Kazakhstan,with moderate temperature and pressure.Many prediction models developed for open-hole completions where the reservoir materials usually possess certain strength are not applicable for the local reservoirs where the materials are significantly weaker even if casing is used to support the wellbore with oil produced through the perforation tunnels.In this context,a prediction model was proposed where the volume of the produced sand was estimated as the volume of the plastic zone of the failed materials surrounding the perforation tunnels.The model assumes an evolving truncated conical shape for the damage zone and takes into account stress distributions and shear failure in this zone.Then,the proposed model was used to estimate sand volumes in 20 wells during oil production with sequential increase of flow rates.The predictions match well with the measured sand volumes in a local oil field.Finally,a sensitivity analysis was conducted on the model performance.It shows that the permeability of the plastic zone was the most significant controlling factor in the prediction results. 相似文献
The aim of this study is to outline the development and changes in pre‐service teachers' technological pedagogical content knowledge (TPACK) assessments during the first 3 years in teacher education. Specifically, research was conducted at three measurement points over a 3‐year teacher education period. The target group consisted of pre‐service teachers (N = 148) from three Finnish universities. Results indicate a growth in confidence related to all TPACK areas during the research period. The strongest gains were in pedagogical content knowledge. In addition, the gains were larger in other areas related to pedagogical knowledge than areas related to technology or content knowledge. In areas without pedagogical knowledge, the changes were more moderate. In the discussion section, recommendations are provided on the potential of longitudinal use of the TPACK model to study and improve the development of pre‐service teachers' TPACK. 相似文献
Catalytic stability with time‐on‐stream is an important aspect in ethanol dry reforming (EDR) since catalysts could encounter undesirable deterioration arising from deposited carbon. This work examined the promotional effect of La on 10%Co/Al2O3 in terms of activity, stability, and characteristics. Catalysts were characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Raman, and X‐ray photoelectron spectroscopy (XPS) measurements whilst catalytic EDR performance of La‐promoted and unpromoted 10%Co/Al2O3 prepared via wet impregnation technique was investigated at 973 K for 72 h using a stoichiometric feed ratio (C2H5OH/CO2 = 1/1). La promoter substantially enhanced both metal dispersion and metal surface area from 0.11% to 0.64% and 0.08 to 0.43 m2 g?1, respectively. Ethanol and CO2 conversions appeared to be stable within 50 to 72 h after experiencing an initial activity drop. The conversion of C2H5OH and CO2 for La‐promoted catalyst was about 1.65 and 1.34 times greater than unpromoted counterpart in this order. The carbonaceous deposition was considerably decreased from 55.6% to 36.8% with La promotion due to La2O2CO3 intermediate formation. Additionally, 3%La‐10%Co/Al2O3 possessed greater oxygen vacancies acting as active sites for CO2 adsorption and hence increasing carbon gasification. Even though graphitic and filamentous carbons were formed on used catalyst surface, La‐addition diminished graphite formation and increased the reactiveness of amorphous carbon. 相似文献
Workload prediction is an essential prerequisite to allocate resources efficiently and maintain service level agreements in cloud computing environment. However, the best solution for a prediction task may not be a single model due to the challenge of varied characteristics of different systems. Thus, in this work, we propose an ensemble model, namely ESNemble, based on echo state network (ESN) for workload time series forecasting. ESNemble consists of four main steps, including features selection using ESN reservoirs, dimensionality reduction using kernel principal component analysis, features aggregation using matrices concatenation, and regression using least absolute shrinkage and selection operator for final predictions. In addition, necessary hyperparameters for ESNemble are optimized using genetic algorithm. For experimental evaluation, we have used ESNemble to combine five different prediction algorithms on three recent logs extracted from real-world web servers. Through our experimental results, we have shown that ESNemble outperforms all component models in terms of accuracy and resource allocation and presented the running time of our model to show the feasibility of our model in real-world applications.
Peel and seeds of red-skinned passion fruit, mango, longan, rambutan, white-flesh and red-flesh dragon fruit were screened for their in vitro antioxidant activity, and determination of a detailed profile of phenolic compounds. Rambutan peel and mango seed extracts exhibited the highest total phenolic content and antioxidant activities (DPPH, ABTS and FRAP values). By using UPLC-QTOF-MS/MS analysis, the profiles of soluble and bound phenolics in the fruit by-products were obtained. Ellagic acid, geraniin, quercetin hexoside, gallic and galloyshikimic acid were predominant in rambutan peel, whereas, mangiferin, ellagic acid and galloy(di)glucoside were the major phenolic compounds in mango seed. Main phenolic compounds in longan peel were ellagic acid, galloyldiglucoside, and gallic acid, while in dragon fruit peel this was isorhamnetin glycoside, isorhamnetin glucorhamoside. Meanwhile, rutin and quercetin hexoside were predominant in passion fruit peel. These findings contribute significantly to the database of phenolic profiles of by-products of tropical fruits. 相似文献