Room temperature photonic crystal defect lasers at near-infrared wavelengths in InGaAsP

Room temperature lasing from optically pumped single defects in a two-dimensional (2-D) photonic bandgap (PBG) crystal is demonstrated. The high-Q optical microcavities are formed by etching a triangular array of air holes into a half-wavelength thick multiquantum-well waveguide. Defects in the 2-D photonic crystal are used to support highly localized optical modes with volumes ranging from 2 to 3 (lambda/2n)(3). Lithographic tuning of the air hole radius and the lattice spacing are used to match the cavity wavelength to the quantum-well gain peak, as well as to increase the cavity Q. The defect lasers were pumped with 10-30 ns pulses of 0.4-1% duty cycle. The threshold pump power was 1.5 mW (approximate to 500 μW absorbed)

A novel wideband dynamic directional indoor channel model based on a Markov process

This document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available

Is Mail Service Pharmacy Cost Beneficial to Plan Sponsors?

The objective of this study was to describe and compare prescription drug costs charged to a plan sponsor for the top 50 maintenance medications provided through retail and mail service procurement channels. Data were obtained for covered beneficiaries of a health plan sponsored by an employer with just over 3,000 covered employees The analytics team at the PBM administering the plan sponsor’s prescription drug benefit provided de-identified claims information for the top 50 maintenance prescription drugs delivered through either mail service or retail procurement methods for this employer over a one year period (7/1/2008 to 6/30/2009). Based on these data, (1) dollar amount difference (mail service minus retail), and (2) percentage difference between mail and retail costs (as a percentage of the lower net cost per day) were computed. The findings revealed that 76 percent of the medication products studied were associated with a lower net cost per day to the plan sponsor through mail service procurement and 24 percent were associated with lower net cost through retail procurement

The contribution of the immune system to parturition

The immune system plays a central role before and during parturition, including the main physiological processes of parturition: uterine contractions and cervical ripening. The immune system comprises white blood cells and their secretions. Polymorphonuclear cells and macrophages invade the cervical tissue and release compounds, such as oxygen radicals and enzymes, which break down the cervical matrix to allow softening and dilatation. During this inflammatory process, white blood cells undergo chemotaxis, adherence to endothelial cells, diapedesis, migration and activation. Factors that regulate white blood cell invasion and secretion include cytokines such as tumour necrosis factor and interleukins. Glucocorticoids, sex hormones and prostaglandins, affect cytokine synthesis. They also modulate the target cells, resulting in altered responses to cytokines. On the other hand, the immune system has profound effects on the hormonal system and prostaglandin synthesis. In animals, nitric oxide has marked effects on uterine quiescence during gestation. At the same time, it plays an important role in regulating the vascular tone of uterine arteries and has anti-adhesive effects on leukocytes. Cytokines are found in amniotic fluid, and in maternal and foetal serum at term and preterm. Several intrauterine cells have been shown to produce these cytoldnes. Since neither white blood cells, cytokines nor nitric oxide seem to be the ultimate intermediate for human parturition, the immune system is an additional but obligatory and underestimated component in the physiology of delivery. Scientists, obstetricians and anaesthesiologists must thus be aware of these processes

Analytical Evaluation of the MoM Matrix Elements

Cataloged from PDF version of article.Derivation of the closed-form Green’s functions has eliminated the computationally expensive evaluation of the Sommerfeld integrals to obtain the Green’s functions in the spatial domain. Therefore, using the closed-form Green’s functions in conjunction with the method of moments (MOM) has improved the computational efficiency of the technique significantly. Further improvement can he achieved on the calculation of the matrix elements involved in the MOM, usually double integrals for planar geometries, by eliminating the numerical integration. The contribution of this paper is to present the analytical evaluation of the matrix elements when the closed-form Green’s functions are used, and to demonstrate the amount of improvement in computation time

Intensification of high-temperature hydrogen degradation of heat-resistance steels caused by heat changes during exploitation on the main steam pipeline of a heat power plant

Запропоновано підхід для оцінювання технічного стану деградованого металу парогонів з урахуванням впливу пусків-зупинок енергоблоків ТЕС. Цей підхід дозволяє встановлювати можливість подальшого використання обладнання після довготривалої роботи. Моделювання пусків-зупинок проводилося в лабораторних умовах термоциклуванням зразків у чистому водні від робочої температури парогону до кімнатної температури. Зреалізовано цей підхід на сталях 12Х1МФ та 15Х1М1Ф за результатами випроб на циклічну тріщиностійкість після різної їх експлуатації на головних парогонах ТЕС і після термоциклування у водні. Визначили ефективний поріг циклічної тріщиностійкості й ефективний час експлуатації, враховуючи різну історію експлуатації. Згідно з цими даними побудовано базову діаграму для сталі 12Х1МФ та 15Х1М1Ф.An approach for evaluation of technical state of degraded metal of steam pipelines taking into account shutdowns of the power units of power plant has been proposed. This approach enables to establish the possibility to use the equipment after long term service. Shutdowns were simulated in laboratory conditions by thermocycling of specimens in pure hydrogen from service temperature of steam pipelines to room temperature. This approach was realized by fatigue fracture testing of 15Kh1M1F and 12Kh1MF steels after different service time and number of shutdowns during exploitation on the heat power plant stem pipelines and after thermocycling in hydrogen. The effective fatigue crack growth resistance thresholds have been determined and the effective operation time has been calculated using the service history data. According to this data the basic diagram for assessment of the 15Kh1M1F and 12Kh1MF steels state has been developed

The COST 259 Directional Channel Model Part II: Macrocells

Abstract — This paper describes the attributes of the COST 259 directional channel model that are applicable for use in the design and implementation of macrocellular mobile and portable radio systems and associated technology. Special care has been taken to model all propagation mechanisms that are currently understood to contribute to the characteristics of practical macrocellular channels and confirm that large scale, small scale, and directional characteristics of implemented models are realistic through their comparison with available measured data. The model that is described makes full use of previously published work, as well as incorporating some new results. It is considered that its implementation should contribute to a tool that can be used for simulations and comparison of different aspects of a large variety of wireless communication systems, including those that exploit the spatial aspects of radio channels, as, for example, through the use of adaptive antenna systems. Index Terms — Direction of arrival, mobile radio channel, smart antenna. I

Study of Power Quality: Problems in Commercial Buildings in Puerto Rico

Abstract-This paper describe studies of power quality done in Puerto Rico. A literature review will be done about different studies made in the past related to power quality problems in P.R. Data, from Lor