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The purpose of this paper is to present the application of the loss approximation method for non-oriented electrical steel developed by the authors. A new model of a toroidal sample with dimensions ensuring high uniformity of the field was presented.

A critical analysis of the methods used was carried out. Based on these considerations, the authors proposed their own loss approximation method, which allows obtaining high accuracy in a wide range of induction and frequency. The proposed method is based on the assumption that for a certain frequency range losses can be describe by two terms formula. For a fixed value of the peak flux density Bm, the graph of specific loss divided by the frequency should have the form of a straight line. Then, the obtained coefficients for different Bm are the basis for approximation with the power function.

The comparison of measurement and approximation results shows that the method allows to obtain very good accuracy in a wide range of induction and frequency.

More detailed studies on the impact of cutting on a larger number of samples with different geometrical dimensions are needed.

Application of the new method provides a better approximation of the curve of the loss and thus a more accurate calculation of the core loss in the electrical machines.

The paper presents the application of the loss approximation method for non-oriented electrical steel developed by the authors. A new model of a toroidal sample with dimensions ensuring high uniformity of the field was presented. It is shown that the approximation introduced allows for high accuracy in a wide range of frequency and magnetic flux density.

The purpose of this paper is to present the distribution of the magnetic field and additional losses analysis of the induction motors (IM) with opened and closed rotor slots.

In the field-circuit approach the distribution and changes of magnetic flux density in the motor are computed using a time-stepping finite element method. The additional losses in each element are evaluated at different frequencies.

An approximate analytical formulation is derived for rapid losses computation confirmed by the results of field-circuit method. For high-voltage motors due to the size ratios of the core and relatively deep stator and rotor slots major role in causing loss of higher harmonics play a fundamental slot harmonics. Higher harmonics order bigger than 100 cause only small part of total higher harmonics core losses. Closed rotor slots construction influenced significantly on no-load losses mainly due to reduction of losses at slot upper part. For nominal load condition that influence is not so strong according to the saturation of slot tips by rotor leakage flux. Nevertheless, core losses at load are several times higher as at no-load.

In future research authors will take into account motors feed from PWM inverter, working in the frequency range up to 400 Hz.

The results of investigation will be used in more detailed design of IMs especially for motors with closed rotor slots.

The methods presented in the paper was not used before. Also results of additional losses in the motor core calculation, especially according motors with closed slots at no load and load conditions are new.

Discusses the 27 papers in ISEF 1999 Proceedings on the subject of electromagnetisms. States the groups of papers cover such subjects within the discipline as: induction machines; reluctance motors; PM motors; transformers and reactors; and special problems and applications. Debates all of these in great detail and itemizes each with greater in‐depth discussion of the various technical applications and areas. Concludes that the recommendations made should be adhered to.

This paper aims to focus on the numerical modelling of 3D structure of surface micromachined (MEMS) accelerometers.

The paper focuses on the methods of mechanical design and analysis of electrostatic accelerometers (comb drive structure) and uses computer simulation procedure leading to final structure design, then to be defined as a basic structure for stress analysis.

The strategy in computer modeling of accelerometer MEMS is satisfactory in order to simulate the electromechanical characteristics of different accelerometer structures (IMEMS).

A novel complex strategy in computer modeling of accelerometer MEMS, based on solid modeling is proposed.

In a printed circuit board assembly (PCBA), the coefficient of thermal expansion (CTE) mismatch between the solder joint materials has a detrimental impact on reliability. The mechanical stresses caused by the thermal changes of the assembly lead to fatigue and sometimes the failure of the solder joints. The purpose of this study is to propose a novel pad design to obtain an interrupted solder/substrate interface, to improve the PCBA reliability.

An interruption in the continuous intermetallic compound (IMC) layer of a solder joint was implemented, by the deposition of a silicone film in the pad, changing its geometry. That change allows a redistribution of stresses in the most ductile zone of the solder joint, the solder. The stress concentration at the solder/substrate interface is reduced, as well as the general state of stress at the solder joint.

A new way was developed to reduce the stress on the solder joints, caused by thermal variations, because of the different components CTEs mismatch. This new method consists of interrupting the IMC layers of the solder joint, strategically, redirecting the usual stresses to a more ductile area of the joint, the solder. This is an innovative method that allows increase the lifetime of PCBAs and the equipments.

In this study, a new pad design concept for higher solder joint reliability was developed to reduce the shear stress in the solder joints because of the CTE mismatch between all the solder joint components.

The purpose of this paper is to investigate the effect of a sealing protective treatment on the water absorption and mechanical properties of acrylonitrile butadiene styrene (ABS)-printed parts by fused deposition modelling. Protective products include aqueous acetone solutions with different concentrations, polyurethane wood sealer and aqueous acrylic-based varnish.

Open porosity was estimated by the absorption coefficient and the total amount of water retained, obtained from water absorption tests. Mechanical characterization was performed by compressive and tensile tests. Different specimens with different build directions and raster angles were used.

The treatments with acetone solutions were not effective in reducing the porosity of ABS parts, as the amount of acetone that reduces effectively the porosity will also affect the sample dimensional stability. The polyurethane treatment was found to reduce the absorption coefficient, but the maximum water content and the open porosity remain almost unchanged in comparison with the ones obtained for untreated specimens. The treatment with an acrylic-based varnish was found to preserve the dimensional stability of the specimens, to reduce the open porosity and to maintain the compression and tension properties of the specimens in different build directions and raster angles.

Surface modification for water tight applications of ABS 3D printing parts enables new designs where both sealing and the preservation of mechanical properties are important. As per the knowledge of the authors, the water absorption and the mechanical behaviour of ABS 3D printed parts, before and after treatment, were not previously investigated.

Introduces a special issue on globalization and the welfare state. Asserts that economic globalization constrains national economic and social policy far more now than ever before, although the level of international trade has not increased that much compared to levels at the beginning of this century. Talks about the political consequences of economic globalization, particularly welfare state retrenchment in the advanced capitalist world. Outlines the papers included in this issue – comparing welfare system changes in Sweden, the UK and the USA; urban bias in state policy‐making in Mexico; and the developing of the Israeli welfare state. Concludes that economic globalization has a limited effect in shaping social welfare policy in advanced capitalist countries; nevertheless, recommends further research into which aspects of economic globalization shape social welfare policy.

Nobody concerned with political economy can neglect the history of economic doctrines. Structural changes in the economy and society influence economic thinking and, conversely, innovative thought structures and attitudes have almost always forced economic institutions and modes of behaviour to adjust. We learn from the history of economic doctrines how a particular theory emerged and whether, and in which environment, it could take root. We can see how a school evolves out of a common methodological perception and similar techniques of analysis, and how it has to establish itself. The interaction between unresolved problems on the one hand, and the search for better solutions or explanations on the other, leads to a change in paradigma and to the formation of new lines of reasoning. As long as the real world is subject to progress and change scientific search for explanation must out of necessity continue.

Investigates urban bias in state policy making in Mexico. Refers to literature claiming that rural poverty in developing nations is a major problem because capitalism reflects an urban bias. Examines social security coverage for the rural poor in Mexico and notes that there are great variations depending on area, suggesting that social security coverage is politically negotiable. Outlines briefly the historical development of Mexico’s welfare state and uses a power resource model to demonstrate how groups with competing interests go about securing benefits from the state. Cites literature on dependency theory, indicating that rural groups have failed to mobilize politically and have therefore not secured the same state resources (such as social security benefits and housing) as urban groups, yet argues that this does not always apply in Mexico, partially due to party politics and bureaucratic paternalism. Explains how data was collected to examine regional variations in social security coverage among the rural poor and how the data was analysed. Reveal that workers in important international export markets (such as cotton and sugar) have greater political leverage in obtaining better social security benefits. Notes also that areas supporting the political party in power obtain better benefits. Concludes, therefore, that rural workers are not powerless in the face of urban capitalism and that urban bias and dependency theories do not reflect the situation in Mexico – rather social security benefits are politically negotiable.

This monograph contains abstracts from the 2005 Employment Research Unit Annual Conference Cardiff Business School, Cardiff University, 6‐7th September 2005