Facing a Problem of Electrical Energy Quality in Ship Networks-measurements, Estimation, Control

In this paper, electrical energy quality and its indices in ship electric networks are introduced, especially the meaning of electrical energy quality terms in voltage and active and reactive power distribution indices. Then methods of measurement of marine electrical energy indices are introduced in details and a microprocessor measurement-diagnosis system with the function of measurement and control is designed. Afterwards, estimation and control of electrical power quality of marine electrical power networks are introduced. And finally, according to the existing method of measurement and control of electrical power quality in ship power networks, the improvement of relative method is proposed.     

Toward relationships-querying in document retrieval systems

A concept of end-user query language with facilities of expressing relationships between objects kept in a data base is presented. The idea of nesting these facilities in typical document system query language is shown. Special kinds of referring terms are designed. Examples of usage of the new facilities are attached.     

On the use of ASTM closed vessel tests in accelerated ageing research

The ASTM D6819-02e3 standard for testing the accelerated ageing of paper, published in 2002, recommends using closed glass vials in order to keep the degradation products in contact with the paper and thus permitting a better simulation of the natural ageing conditions inside closed books. In the present study, the actual conditions and their stability inside closed vessels have been evaluated. The necessity of assuring a very high sealing performance (tightness) of the systems in order to avoid leakage of water vapour is the main drawback of this ageing method. Systematic studies presented in this publication tried to monitor this tightness and have provided data that helped to answer the question of what circumstances could lead to achieving its improvement. Both gravimetric monitoring of water content in vials and “in situ” IR measurements of the aged paper humidity have been applied for this purpose. As a result, better sealing materials (gaskets and caps) than those recommended by the ASTM standard, have been found. Additionally, application of a dynamometric spanner for closing the vials is recommended, as this is a guarantee of reasonably high and recurring tightness of the systems used in tests. Nevertheless, the systematic, linear with time, loss of moisture for all used vials was observed. A 9% loss of the initial moisture content in samples of the aged paper was observed for the tested conditions (14 days at 90 °C). Therefore, it seems that including some kind of gravimetric control for ageing tests performed in closed vessels is of essential importance.Kinetic studies of accelerated ageing in both closed and open systems, as monitored by DP and breaking length measurements, unexpectedly show that no statistically meaningful difference of degradation rates can be observed. On the other hand, the pH and whiteness index values reveal a meaningful difference between the rates of ageing in these systems, thus confirming the basic assumption of the ASTM test concerning the interaction of paper degradation products with the paper itself.     

The implications of academic entrepreneurship for university administration

The authors argue that universities should offer training and education in Entrepreneurship to all students but particularly to those wishing to become entrepreneurs. Certain institutional changes in favour of Entrepreneurship should be made at the level of governance. Once started, Entrepreneurship programmes can reimburse the initial investments made in them as successful spin‐off enterprises multiply and their founders collaborate with their alma maters. The case of the “International Education Center for Students with Motor Disabilities” at the Cracow University of Economics is evoked. It trains handicapped students in telemarketing and other forms of distance business enterprise by use of the new technologies.     

船舶电气测量的新方法 ——对机舱和供电的测量

根据船舶电气技术的发展 ,阐述了船舶报警系统 ,监视与控制系统及电能质量的测量与控制的最新趋势。文中还阐述了一些有关电力系统的观点     

Assessment of Electric Power Quality in Ships''Modern Systems

The paper deals with the selected problems of electric power quality in ships'modern systems.In the introduction the fundamentals of electric power quality assessment,such as the relations and consequences among power quality phenomena and indices,secondly as the methods and tools as well as the appropriate instrumentation,have been shortly presented.Afterwards,the basic characteristic of power systems on modern ships has been given.The main focus of the paper is put on the assessment of electric power quality in ships'systems fitted with converter subsystems.The state of the art and actual tendencies in the discussed matter have been shown.Some chosen experimental results,based on the research carried out under supervision of the author,have been presented,too.Finally,some concluding issues have been shortly commented on.     

船舶电力系统参数测量的应用和故障诊断

提出把船舶电力系统作为船舶发展过程中的一个重要组成部分来认识，描述了实际应用中占大多数的船舶电站的结构，并提及了船舶电网的特殊性，即其柔性功能及所存在的大量的扰动因素。文章着重讨论了参数测量的利用、诊断对船舶安全和船舶电力系统的有效运行所起的重要作用，指出了这些测量的特性，同时还提出了实现参数测量的进一步利用及用于故障诊断的基本设备和系统设想。笔者不仅叙述了上述内容在现阶段所取得的成就，而且还指出了其发展趋势。