EFFECT OF VARIOUS ANTIOXIDANTS ON THE OXIDATIVE STABILITY OF ACID AND ALKALI SOLUBILIZED MUSCLE PROTEIN ISOLATES

Protein isolates prepared from cod ( Gadus morhua ) myofibrillar proteins using acid or alkali solubilization are susceptible to oxidative rancidity. Oxidation could be delayed by the exogenous addition of antioxidants. The objective of this research was to compare the efficacy of antioxidants such as δ-tocopherol, butylated hydroxyanisole (BHA) and propyl gallate, to inhibit oxidation in acid- and alkali- solubilized cod protein isolates. Oxidation was catalyzed using cod hemolysate. Oxidation of lipids was monitored by the measurement of thiobarbituric acid reactive substances and painty odor. Results showed that protein isolates prepared using the acid process was significantly ( P <  0.05) more susceptible to lipid oxidation than alkali-solubilized protein isolates. Regardless of pH treatments, the efficacy of various antioxidants decreased in the order propyl gallate  >  BHA  >  δ-tocopherol.

PRACTICAL APPLICATIONS

Research has shown that seafood available for human consumption is rapidly getting depleted and that many fish species may become extinct in the next half-century or so. Acid and alkali solubilization methods are recent but well-known techniques used for preparing protein isolates from under-utilized aquatic species and the by-products of seafood industry. Although numerous researchers have studied the use of acid and alkali processes on several sources of seafood, almost no research has been done on the use of antioxidants to protect protein isolates from lipid oxidation. In our research, we have studied the effect of various antioxidants on the oxidative stability of acid- and alkali-solubilized fish myofibrillar proteins. The results from this work will enable the seafood industry to properly identify the process and the type of antioxidants required for making muscle food products with increased oxidative stability.     

利用回归和人工神经网络预测城市雨水径流总磷模型的有效性

利用人工神经网络(ANN),探讨在不无监测系统的集水区城市降水质量预测的适用性.预测使用常规的气候和地理数据集,通过构建背景传播的神经网络和回归联合模型,克服利用逐步回归的方法对数据进行分析时违背独立数据假设的问题.研究通过交叉验证用于确定停止降水时间为输入变量参数,利用地区平均浓度(EMC)作为独立的变量,构建的模型比用负荷量构建的模型更精确.数据域和输入变量的选择对回归模型的准确性也有较大影响.但计算效率、动量和隐节点数目的选择等因素,对人工神经网络模型准确性的影响较小.同时,回归和人工神经网络模型的降水质量预测结果十分相似,但在不无监测系统的集水区域城市降水质量的预测方面,回归模型更有实效性.     

Studies on the influence of power ultrasound on dye penetration in leather dyeing using photomicrographic analysis

The use of power ultrasound in enhancing diffusion rate in various chemical as well as physical processes is gaining in importance. The influence of power ultrasound in the leather dyeing process on enhancing the penetration of dye through the leather matrix was studied. The penetration of dye through a leather cross-section for a given time in the presence and absence of an ultrasonic field (33 kHz, 150 W) was studied by photomicrographic analysis using a stereomicroscope. Different types of black dyes, such as Acid black 1, Metal complex black 194 and Direct black 155, were used for dyeing leather in the present study. Photomicrographic analysis of a cross-section of dyed leather indicated better penetration of dyes through the leather matrix with the use of ultrasound than without it. Therefore, the results indicate that ultrasound helps to improve the diffusion of dye and to reduce diffusional resistance in the leather dyeing process.     

利用厌氧生物反应器处理奶牛饲养废水

澳大利亚的畜禽养殖业,如奶牛饲养业,在不断的发展壮大,在生产中产生了大量的奶牛饲养废水,这些废水长期以来一直被视为主要的污染物扩散源.但是,常规的奶牛饲养废水处理方法,如两池系统,对该废水的处理并不充分.另外,从营养物质管理规划和固态粪便处理的角度讲,新的相关法规要求对该废水应采用新的处理和管理方法.厌氧消化（AD）是一种可替代技术,该技术不仅能使环境污染实现最小化,而且能够实现资源回收利用,尤其是可再生生物燃料（甲烷）产生,可实现资源利用的最大化.本研究以奶牛饲养废水为对象,在对AD技术进行简要综述的基础上,基于奶牛场废水管理实践和相关法规,对澳大利亚奶牛饲养场采用AD方法的必要性进行讨论.在澳大利亚,奶牛饲养场废水处理的独特之处在于采用了高效的厌氧消化池.本研究在实验过程中采用厌氧固定膜消化池来处理奶牛饲养场废水.初步结果表明,厌氧固定膜消化池能够将奶牛饲养场冲刷废水成功地转变为生物燃料气体.     

Structural integrity assessment of FBR components using a distributed computing environment

In this work, the structural integrity of the critical components of the fast breeder reactor (FBR) that are subjected thermal striping is assessed using a fracture mechanics approach based on linear elastic fracture mechanics (LEFM). The structural integrity is assessed in terms of the actual life of the component for a particular difference between the hot and cold liquid temperatures at the critical mixing velocities. A generalized procedure is attempted for the computation of fatigue life. It is demonstrated in this work that the analysis procedure adopted is computationally very efficient. Green's function method is used for transient mode I crack propagation analysis. An inherent parallelism in the method is exploited for computational efficiency. A distributed computing environment is, therefore, used to demonstrate the effectiveness of Green's function method for crack propagation analysis for the kind of problem solved in this work. A simple idealization in the form of flat plate geometry is used in a numerical example to show the computational efficiency. The method shows a good scale‐up justifying the benefit of using a distributed computing environment given a large amount of input data for the thermal striping problem.     

Experimental investigation and ANN modeling on improved performance of an innovative method of using heave response of a non-floating object for ocean wave energy conversion

To convert wave energy into usable forms of energy by utilizing heaving body, heaving bodies (buoys) which are buoyant in nature and float on the water surface are usually used. The wave exerts excess buoyancy force on the buoy, lifting it during the approach of wave crest while the gravity pulls it down during the wave trough. A hydraulic, direct or mechanical power takeoff is used to convert this up and down motion of the buoy to produce usable forms of energy. Though using a floating buoy for harnessing wave energy is conventional, this device faces many challenges in improving the overall conversion efficiency and survivability in extreme conditions. Up to the present, no studies have been done to harness ocean waves using a non-floating object and to find out the merits and demerits of the system. In the present paper, an innovative heaving body type of wave energy converter with a non-floating object was proposed to harness waves. It was also shown that the conversion efficiency and safety of the proposed device were significantly higher than any other device proposed with floating buoy. To demonstrate the improvements, experiments were conducted with non-floating body for different dimensions and the heave response was noted. Power generation was not considered in the experiment to observe the worst case response of the heaving body. The device was modeled in artificial neural network (ANN), the heave response for various parameters were predicted, and compared with the experimental results. It was found that the ANN model could predict the heave response with an accuracy of 99%.     

Laboratory experiment on using non-floating body to generate electrical energy from water waves

This paper describes an innovative method of using a non-buoyant body to harness ocean waves. All the point absorbers are buoyant in nature and move up due to buoyancy and come down because of gravity. The point absorbers are designed to move along the waves to make the device efficient. These devices face excessive stress during the rough weather on account of the extreme motion of waves and cause the total device failure. The present study shows that using a non-buoyant body for conventional point absorber principle is much efficient and safer than any other device proposed till today. A small scale wave energy converter with non-buoyant body was designed, fabricated and tested in small scale wave maker. An electrical generator was coupled with the device to generate electrical energy from harnessed waves. The generator was electrically loaded and the generated power was measured. It was found from the experiments that the proposed device showed a significant improvement in electricity generation and safety during extreme conditions. In addition to the electricity generation, the characteristics of the device were also studied by using various wave and device parameters.     

利用农业废弃物的生物制氢

利用农业废弃物进行生物制氢,生物质产生的氢被认为是最清洁的燃料,其与甲烷和化石燃料燃烧产物比较,燃烧的副产品只有水．产氢菌通过其耐热特性进行分离．影响产氢菌产生氢气的因素有：pH、温度、基质浓度和生物量比例等．研究显示：当以30％的葡糖糖作为基质、温度为40℃、pH为4．3时,产氢效率最好．其结果为进一步研究提高批反应及连续厌氧产氢效率提供支撑．     

Malposition of hemodialysis catheter in left superior intercostal vein

Malposition of hemodialysis catheter needs to be identified promptly. Straight descent of left side internal jugular catheter mandates a thorough evaluation than unnecessary apprehensions. We report an unusual case of straight descent of hemodialysis catheter into superior intercostal vein.