Computer-aided protective relay setting system for large power networks

This paper introduces a protective relay setting system capable of handling a large network up to 10,000 buses. The remarkable features are such useful functions as network analysis (fault analysis, load flow calculation, zero-sequence current calculation, etc.), relay operation simulation, and automated setting coordination tasks. Fault currents in the maximum and the minimum operation networks are calculated to examine the setting values. The protection zones are searched automatically along the network connection. Protection coordination tasks among the primary and the backup relays composed of different types of relays can be performed by the relay operation simulation. The system is built on an engineering workstation, which works in cooperation with other network operation support systems. Its graphical user interface helps every engineer to examine the relay setting using a variety of databases.     

胜利油田耿井水库浮游植物增长潜力限制性营养研究

目的通过对胜利油田耿井水库预沉池，输水渠及水库的水样进行AGP试验，考察营养元素对浮游植物羊角月牙藻增长的影响，确定耿井水库浮游植物的限制性营养元素及其质量浓度限制范围．为该地区水库富营养化的防控提供科学的依据．方法水样采用高压锅灭菌并过滤和过滤两种预处理方法，外加氮磷营养元素，用羊角月牙藻进行AGP试验．结果高压锅灭菌并过滤预处理的水样浮游植物增长潜力明显比过滤预处理水样高出两倍．浮游植物的增长主要依靠磷的质量浓度，对浮游植物增长限制的磷的限制质量浓度是0．025～0．05mg／L．结论磷是胜利油田耿井水库的限制性营养元素，在控制和治理富营养化方面应首先考虑控制和削减总磷的含量．     

KINETICS OF ABSORPTION OF OXYGEN IN ALKALINE SOLUTIONS CONTAINING A QUINONE-TYPE COMPOUND

The rates of absorption of pure oxygen in alkaline aqueous solutions containing sodium salt of 1,4-naphthoquinone 2-sulfonic acid (NQS) as a catalyzer for the Takahax desulfurization process were measured at 25°C using a liquid jet column.

The kinetics of the absorption was examined based on the theory for gas absorption accompanied by an irreversible second order chemical reaction. The pH of the solution, that is, the concentration of hydroxyl ion plays an important role in a reaction of first order with respect to oxygen and to NQS. The reaction rate constant is directly proportional to pH in the range 9.8-11.5, for more alkaline solutions being found to be 4.5 × l0⁶L/mole ? s.     

Prediction of temperature and water level in a spent fuel pit during loss of all AC power supplies

A prediction method for water temperature in a spent fuel pit of a pressurized water reactor (PWR) has been developed to calculate the increase in water temperature during the shutdown of cooling systems. In this study, the prediction method was extended to calculate the water level in a spent fuel pit during loss of all AC power supplies, and predicted results were compared with measured values of spent fuel pools in the Fukushima Daiichi Nuclear Power Station. The calculations gave reasonable results, but overestimated the decreasing rate of the water level and the water temperature. This indicated that decay heat was overestimated and evaporation heat transfer from the water surface was underestimated. Results of calculations with 80% decay heat and 155% (Unit 4 pool) or 230% (Unit 2 pool) evaporation heat flux were in good agreement with measured values. The data-fitted evaporation heat fluxes agreed rather well with the evaporation heat transfer correlation proposed by Fujii et al.     

Application of two immunochromatographic test kits to screening of four kinds of allergic substances in imported foods

We tested for four kinds of allergic substances (egg, milk, wheat and peanuts) in 52 imported processed foods using immunochromatographic test kits (ITK). ELISA was also employed to confirm the effectiveness of the ITK. Among 92 data from 23 samples, allergic substances were detected in 9 cases with one kind of ITK, but not with the ELISA test. Among 116 data from 29 samples, 6 were negative with one kind of ITK and but positive with the other ITK. These results suggested that these 4 kinds of allergic substances in imported foods can be detected by using a double-check method with two kinds of ITK.     

Relationship between Pectic Substances and Strand Separation of Cooked Spaghetti Squash--Part 2. Changes in Firmness,Histological Structure and Pectic Substances during Soaking in Pectin Extractants

The flesh of spaghetti squash separates into strands when cooked. The purpose of this paper is to investigate the cause of strand separation （during cooking） by soaking for 24 h at 35 ℃ in solutions with three kinds of pectin extractant. The changes in strand separation, firmness, histological structure and the pectin of flesh during soaking in 0.01 N HCI solution （pH 2.0）, 0.035 M ammonium oxalate solution （pH 4.0） or 2% sodium hexametaphosphate solution （pH 4.0） were investigated. When flesh was soaked in the HCI solution, the separation into strands and removal of calcium and magnesium were greater than that soaked in other pectin extractants. High methoxyl pectin was extracted by soaking in HC1 solution （pH 2.0） due to removal of polyvalent cations. This result shows that high methoxyl pectin glues strands together in the flesh of spaghetti squash. The shape of the cells which constituted strands was round; on the other hand, that of cells surrounded strands was elongated. When cooked in boiling water or soaked at pH 2.0, the shape of the former cells was maintained, but the latter cells, which contributed to adhesion between strands, broke down. Thus, the flesh separated into strands. When flesh was boiled for 15-30 min, pectin degraded and dissolved in the cooking solution; consequently, the flesh separated into strands and also the middle lamella of cell walls of strands separated. However, pectin remaining in strands maintained their crispness.     

Onion-like carbon-encapsulated Co,Ni, and Fe magnetic nanoparticles with low cytotoxicity synthesized by a pulsed plasma in a liquid

We synthesized onion-like carbon-encapsulated Co, Ni, and Fe (Co–C, Ni–C, and Fe–C) magnetic nanoparticles with low cytotoxicity using pulsed plasma in a liquid. The pulsed plasma is induced by a low-voltage spark discharge submerged in a dielectric liquid. The face-centered cubic Co and Ni, and body-centered cubic Fe core nanoparticles showed good crystalline structures with an average size between 20 and 30 nm were encapsulated in onion-like carbon coatings with a thickness of 2–10 nm. Vibrating-sample magnetometer measurements revealed the ferromagnetic properties of as-synthesized samples at room temperature (Co–C = 360 Oe, Fe–C = 380 Oe, and Ni–C = 211 Oe). Raman-spectroscopy analysis found onion-like carbon shells composed of well-organized graphitic structures. Thermal gravimetric analysis showed a high stability of the as-synthesized samples under thermal treatment and oxidation. Cytotoxicity measurements showed higher cancer cell viability than samples synthesized by different methods.     

处理水AGP值对受纳河流水质的影响

结合藻类增殖潜能试验(AGP试验)探讨了进行污水深度处理的必要性。试验结果表明,污水厂排水的AGP值在94～400mg/L,会导致受纳水体产生富营养化,因此需对污水进行深度处理以去除氮和磷,并加强对流域的水质管理。     

稻田花岗岩单轴拉伸强度和变形 各向异性特征

 为查明稻田花岗岩的强度及变形之各向异性特征,从同一个较大岩块试样的3个相互垂直的方向采制圆柱形拉伸试样,对此进行单轴拉伸实验。结果表明,稻田花岗岩的抗拉强度和变形常数随拉应力的作用方向不同而发生明显变化。在与rift面相垂直的方向拉伸时,其强度和弹性模量都明显小于其他方向。而且,实验结果也表明,抗压强度的各向异性程度比其他各种物性指标的各向异性程度都要大。此外,还设计了一个新的试件安装方式,能够在拉伸过程的任何一个中间阶段非破坏地取下试件以对其进行显微观察等。用此方法,成功地取下一个超过峰值强度且未完全拉断的试件,并切取内部的切片进行显微观察。结果表明,由拉伸所形成的花岗岩中的裂纹主要穿过矿物粒子内部,并不沿着粒子边界延伸。