Microstrip Coupler Design Using Bat Algorithm

Evolutionary and swarm algorithms have found many applications in design problems since todays computing power enables these algorithms to find solutions to complicated design problems very fast. Newly proposed hybrid algorithm, bat algorithm, has been applied for the design of microwave microstrip couplers for the first time. Simulation results indicate that the bat algorithm is a very fast algorithm and it produces very reliable results.Comment: 7 pages, 4 figures, 1 tabl

Consumption Patterns around the Time of Retirement: Evidence from the Consumer Expenditure Surveys

This study,using the Consumer Expenditure Surveys from 1984 through 1998, revisits the widely pronounced retirement-savings puzzle, which claims the existence of a sharp drop in consumption at the time of retirement. In contrast to previous work, I find that consumption of the retired households is consistent with the smoothing behavior implied by the conventional permanent income/life-cycle models. The results present evidence that the elderly actually do not reduce their standard of living around the time of retirement due to a shortage in savings or some other reasons. While the evidence does not favor a dramatic drop in consumption, the composition of consumption changes significantly as households move into the retirement period. The difference between the results of this study and those of the previous work is mainly driven by the fact that I use a comprehensive measure of consumption that includes not only nondurables and services but also service flows from housing and durables. Moreover, using detailed information on the prices faced by the households yields a more accurate measure of household consumptionConsumption, Well-being of the Elderly, Retirement

Do Non-standard Working Hours Cause Negative Health Effects? Some Evidence from Panel Data

What does the around-the-clock economic activity mean for workers’ health? Despite the fact that non-standard work accounts for an increasing share of the job opportunities, relatively little is known about the potential consequences for health and the existing evidence is ambiguous. In this paper I examine the relationship between non-standard job schedules and workers’ physical and mental health outcomes using longitudinal data from the Household, Income and Labour Dynamics in Australia (HILDA). Specifically, the four health indicators considered are self-rated health and the SF-36 health indices for general health, mental health and physical functioning. In terms of direction of the effects, overall results generally suggest a negative relationship between non-standard work schedules and better health for both males and females. Regarding the statistical significance and magnitudes of the effects, however, we observe apparent differences between males and females. Among females, most of the coefficients in all models are statistically insignificant, which implies very small magnitudes in terms of the correlation between non-standard working hours and health. These results apply uniformly to all health measures investigated. Among males, on the other hand, the negative relationship is more noticeable for self-rated health, general health and physical functioning than for mental health. The pooled OLS and random effects coefficients are usually larger in magnitude and more significant than the fixed effects parameters. Nonetheless, even the more significant coefficients, fortunately, do not imply large effects in absolute terms.Non-standard work, physical health, mental health

Vitamins Reverse Endothelial Dysfunction Through Regulation of eNOS and NAD(P)H Oxidase Activities

Antioxidant vitamins C and E have protective properties in genetic hypertension associated with enhanced oxidative stress. This study investigated whether vitamins C and/or E modulate vascular function by regulating enzymatic activities of endothelial nitric oxide synthase (eNOS) and NAD(P)H oxidase using thoracic aortas of 20- to 22-week-old male spontaneously hypertensive rats (SHR) and their matched normotensive counterparts, Wistar-Kyoto rats (WKY). SHR aortas had impaired relaxant responses to acetylcholine but not to sodium nitroprusside, despite an 2-fold increase in eNOS activity and NO release. The levels of superoxide anion (O2 ), a potent NO scavenger, and NAD(P)H oxidase activity were also 2-fold higher in SHR aortas. Mechanical but not pharmacological inactivation of endothelium (by rubbing and 100 mol/L L-NAME, respectively) significantly abrogated O2 in both strains. Treatments of SHR aortas with NAD(P)H oxidase inhibitors, namely diphenyleneiodinium and apocynin, significantly diminished O2 production. The incubation of SHR aortas with different concentrations of vitamin C (10 to 100 mol/L) and specifically with high concentrations of vitamin E (100 mol/L) improved endothelial function, reduced superoxide production as well as NAD(P)H oxidase activity, and increased eNOS activity and NO generation in SHR aortas to the levels observed in vitamin C- and E-treated WKY aortas. Our results reveal endothelial NAD(P)H oxidase as the major source of vascular O2 in SHR and also show that vitamins C and E are critical in normalizing genetic endothelial dysfunction through regulation of eNOS and NAD(P)H oxidase activities

Broken lines of Il/Legality and the reproduction of state sovereignty: the impact of visa policies on immigrants to Turkey from Bulgaria

After the granting of citizenship to the 300,000 Turkish migrants from Bulgaria in 1989, the Turkish state has proceeded to enact a series of visa regime changes concerning more recent migrants from Bulgaria, who, according to the most recent modification, are only allowed to stay for ninety days within any six month period. This paper argues that the arbitrariness sustained by Turkish immigration policies partakes, on the one hand, in more global trends to increase the vulnerability of the dispensable workforce required by neoliberal market economies and, on the other hand, the arbitrariness enhances the political power of the state within and outside of its borders. The temporary legalization of Bulgarian Turkish migrants in return for voting in the Bulgarian elections reveals that the state consolidates its transnational political power by drawing and redrawing the broken lines of legality/ illegality. Moreover we demonstrate not only the ways in which the migrant population from Bulgaria is managed but also the strategies deployed by the migrants themselves in the face of such sovereign acts

Design and implementation of a control system for use of galvanometric scanners in laser micromachining applications

In the recent years, laser machining technology has been used widely in industrial applications usually with the aim of increasing the production capability of mass production lines - especially for fast marking, engraving type of applications where speed is an important concern - or manufacturing quality of a certain facility by increasing the level of accuracy in material processing applications such as drilling, cutting; or any scientific research oriented work where high precision machining of parts in sub millimeter scale might be required. A galvanometric scanner is a high precision device that is able to steer a laser beam with a mirror attached to a motor, whose rotor angular range is usually limited with tens of degrees in both directions of rotation; and position is controlled either by voltage or current. Due to their lightness, the rotor and the mirror can move very fast, allowing fast marking (burning out) operation with the laser beam. This can be evaluated as a great advantage compared to slower mechanical appliances used for cutting/machining of different materials. This study concentrates on the analysis of galvanometric scanner system components; and the design and implementation of a hardware and software based control system for a dual-axis galvo setup; and their adaptation for use in laser micromachining applications either as a standalone system or a modular subsystem. Analysis part of the thesis work contains: evaluation of dominant laser micromachining techniques, an overview of the galvanometric scanner system based approach and related components (e.g. electromechanical, electrical, optical), understanding of working principles and related simulation work, compatibility issues with the target micromachining applications. Design part of the thesis work includes: the design and implementation of electronic controller board, intermediate drive electronics stage, microcontroller programming for machining control algorithm, interfacing with graphical user interface based control software and production of necessary mechanical parts. The study has been finalized with experimental work and evaluation of obtained results. The results of these studies are promising and motivate the use of laser galvanometric scanner systems in laser micromachining applications