Storage stability of a high protein food beverage powder prepared from the Nigerian ‘red skin’ groundnut (Arachis hypogaea) protein concentrates

A high protein, groundnut-based powder reconstitutable into a milk-like beverage was packed in polyethylene bags and in lacquered tin cans, and stored at both room temperature (25 ± 2°C) and in a domestic refrigerator (5 ± 2°C) for 60 days. Storage stability was evaluated by analysing periodically for changes in physical characteristics, proximate composition, and development of browning and rancidity, and assessing moisture sorption characteristics. Protein, lipid, total soluble sugars, peroxide value, total carbonyls and extinction values of the ethanolic extract remained practically constant during storage. The isotherm curves exhibited the characteristic sigmoidal shape typical of high protein foods. There was a greater increase in density, hygroscopicity and wettability in polyethylene-packed samples at both temperatures suggesting that the lacquered tin can leads to better keeping quality for this product.     

A novel nickel-based mixed rare-earth oxide/activated carbon supercapacitor using room temperature ionic liquid electrolyte

Mesopore nickel-based mixed rare-earth oxide (NMRO) and activated carbon (AC) with rich oxygen-contained groups were prepared as electrode materials in a supercapacitor using room temperature ionic liquid (RTIL) electrolyte. These electrode materials were characterized by XPS, XRD, N₂ adsorption, SEM as well as various electrochemical techniques, and showed good properties and operated well with RTIL electrolyte. A 3 V asymmetrical supercapacitor was fabricated, which delivered a real power density of 458 W kg⁻¹ as well as a real energy density of 50 Wh kg⁻¹, and during a 500-cycle galvanostatic charge/discharge measurement, no capacity decay was visible. Such promising energy-storage performance was to a large extent ascribed to nonvolatile RTIL electrolyte with wide electrochemical windows and high stable abilities worked with both electrode materials.     

An accurate volumetric differential pressure method for the determination of hydrogen storage capacity at high pressures in carbon materials

Widely different hydrogen adsorption capacities have been reported for a variety of carbon materials which have attracted attention for hydrogen storage. This has led to doubts as to the validity of some of the claims and it has been suggested that one possible reason for the disparate hydrogen sorption capacities may lie in the inaccurate measurement of the hydrogen adsorbed. The aim of the work described in this paper was to make a contribution to this debate by developing a means and method of producing repeatable, accurate measurements of hydrogen sorption capacity in carbon materials. The apparatus developed is a volumetric differential pressure set-up operating at up to 10 MPa and the method has a conservative limit of detection of 0.1 wt% and an accuracy of ±0.05 wt%, using 1.0-2.5 g samples of the carbon materials studied. These included a carbon nanofiber sample and a series of activated carbons, the latter displaying a direct correlation between the BET effective surface area and the hydrogen sorption capacity of the materials. The amount of hydrogen adsorbed was less than 1 wt% for all the carbons examined.     

新型聚氨酯固-固相变储能材料的组成与热性能的关系

利用差示扫描量热仪、傅里叶红外光谱仪、广角X射线衍射仪研究了一种新型的以聚乙二醇为软段的聚氨酯相变储能材料。结果表明，当软段含量低于90％（质量分数，下同）时，即使温度高于聚乙二醇的熔点，此类材料仍不会熔化成液体，而表现出一种固-固相变行为。该聚氨酯储能材料相变焓较大，相变温度适中，且随着软段含量的减少，材料相变焓和相变温度呈递减趋势。其相变过程实质是聚氨酯软段聚乙二醇由结晶固态转变为无定形固态的过程。     

Effects of washing with oxidising agents on the gel-forming ability and physicochemical properties of surimi produced from bigeye snapper (Priacanthus tayenus)

The effects of washing with hydrogen peroxide (H₂O₂) and sodium hypochlorite (NaOCl) solutions on the gel-forming ability and physicochemical properties of surimi produced from bigeye snapper (Priacanthus tayenus), stored in ice for up to 14 days, were investigated. Generally, pH and the trichloroacetic acid (TCA)-soluble peptide content of washed mince varied, depending on the type of oxidizing agent and storage time of the fish. With increasing time of storage, the pHs of water- and H₂O₂-washed mince were lower than that of NaOCl-washed mince (P < 0.05). However, no differences in the TCA-soluble peptide contents of the resulting mince washed with any media were observed (P > 0.05). Washing with 20 ppm NaOCl resulted in the highest increase in both the breaking force and the deformation of mince from fish stored in ice for all the times studied (P < 0.05). Natural actomyosin (NAM) extracted from NaOCl-washed mince had higher surface hydrophobicity and disulfide bond (SS) content than that of water-washed mince (P < 0.05). With no effect on Ca²⁺-, Mg²⁺-, or Mg²⁺–Ca²⁺-ATPase activities, NaOCl washing resulted in an increase in Mg²⁺–EGTA-ATPase activity of NAM (P < 0.05). The results suggested that washing mince with the appropriate type and concentration of oxidizing agent can improve the gelling ability of surimi, particularly from low quality fish.     

模块化蓝光光存储性能静态测试系统

蓝光光存储是信息存储领域发展的一个重要方向。测试系统是研究蓝光光存储材料的必备条件，为建立蓝光光存储研究平台，设计和搭建了一套模块化蓝光光存储性能静态测试系统。激光工作波长为406．7nm。系统采用调制解调技术降低系统噪声，提高测量粘度：采用光点移动模式降低对样品尺寸的要求；采用纳米平台提高记录点的反复定位性能。实验结果证明测试系统性能良好，可以满足蓝光光存储性能静态测试要求。     

Effects of irradiation in combination with waxing on the essential oils in orange peel

The study evaluated the effects of waxing, irradiation dose and post‐irradiation storage time on the essential oils in orange peel. Mature oranges (Maroc late) waxed or unwaxed were treated with 1 or 2 kGy radiation and stored for 9 weeks at 20 °C and 40–50% RH. Essential oils from the peel were extracted and analysed by GC. Results showed that D ‐limonene was significantly lower in waxed oranges; levels in samples treated with 2 kGy were higher than those in non‐irradiated or treated with 1 kGy. Linalool, methyl anthranilate and 3,7‐dimethyl‐2,6‐octadienal decreased as the dose increased. Levels of linalool increased with storage time but D ‐limonene was unaffected. These results may aid in guaranteeing the quality of orange essential oils during storage time. Copyright © 2004 Society of Chemical Industry     

冷库多台冷风机电热融霜时间与温度双重自动控制方案

从节能和可靠运行的角度提出冷库多台冷风机电热融霜时间与温度双重自动控制方法.     

Interconnected power systems with superconducting magnetic energy storage

The objective of this work is to discuss the concept of back‐to‐back interconnection systems with energy storage, especially with a Superconducting Magnetic Energy Storage (SMES) incorporated into a back‐to‐back DC link. In this case, each converter of the back‐to‐back system is used as a power conditioning system for the SMES coils. Since the AC–DC converter can be designed independently of the frequency of the power system, a two‐way switch is connected to the AC side of each converter. This two‐way switch can select the interconnected power systems. By using the two‐way switches, this system can provide the stored energy in the SMES system to each interconnected power system through two AC–DC converters. For instance, lower‐cost power of each power network can be stored through two converters during the off‐peak hours and made available for dispatch to each power network during periods of demand peak. Then this system increases the reliability of electric power networks and enables the economical operations depending on the power demand. This paper describes the unique operations of the back‐to‐back interconnection with SMES and discuses the optimal SMES configuration for a 300‐MW‐class back‐to‐back interconnection. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 164(2): 37–43, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20482     

Hydrocarbon storage in unlined rock caverns in Greek limestone

The existence of tank farms in the vicinity of cities is a principal component of the urban vulnerability and risk conditions. Even if such environments have been accepted in the past, the enforcement of stricter environmental legislations and the emerging of a strong public opposition towards this co-existence, usually result in the relocation of the facilities. Nevertheless, the relocation process has to overcome a great deal of issues, such as high land cost and strong opposition from neighbouring communities, that often hinder or might even postpone the whole project. Answer to such standstill cases can be given by the development of underground complexes that can facilitate the storage requirements, efficiently and with enhanced environmental protection. Hence, the first area that should be considered for the tank farm relocation is found right beneath the existing facilities. This paper presents the Greek experience, paying special attention to the storage facilities found in the Perama area. The development of an underground storage complex is proposed in that particular area, which could finally offer a viable solution, satisfying the interests of all involved parties. The unlined caverns are to be excavated in limestone bedrock and the characteristics of this alternative are illustrated in detail, followed by the comparative cost analysis between the underground scheme and the surface relocation of the tank farm to another area in Attica.