Heat transfer in flow through a porous medium bounded by an infinite vertical plate under the action of a magnetic field

An analysis of steady two-dimensional flow, of an electrically conducting fluid through a porous medium, occupying a semi-infinite region of the space bounded by an infinite, vertical and porous limiting surface under the action of a transverse magnetic field is considered. Approximate solutions have been derived for the velocity and temperature fields and the rate of heat transfer (Nusselt number). The variations of the velocity and Nusselt number are shown on graphs.     

Dynamic Properties of a WDM Switching Module Based on Active Microring Resonators

The switching properties of a resonator consisting of two serially cascaded active microrings (MRs) are reported. The switching is achieved through the variation of the refractive index and the losses of the MRs with current injection, which alters the overall output spectral response. The switch is suitable for optical burst switching systems and metro architectures as it provides fast optical switching in the nanosecond scale with contrast ratio higher than 30 dB for 10-Gb/s intensity modulated signals. The capacity of the switch can be remarkably increased if multiwavelength switching is employed.      

Nonsingular Constant Modulus Equalizer for PDM-QPSK Coherent Optical Receivers

Adaptive electronic equalizers using the constant modulus algorithm (CMA) algorithm often converge to a singular coefficient matrix that produces the same signal at multiple outputs. We address this issue in the context of optical communications systems with polarization-division multiplexing and coherent receivers. We study, by computer simulation, the performance of multiuser CMA equalizer, an enhanced CMA equalizer initially proposed for use in wireless multiuser and later multiple-input/multiple-output communications systems. We show that the proposed adaptive electronic equalizer does not exhibit singularities and, therefore, is superior to the commonly used CMA equalizer.     

Extensive apoptosis of bone marrow cells as evaluated by the in situ end-labelling (ISEL) technique may be the basis for ineffective haematopoiesis in patients with myelodysplastic syndromes

By using data from the Bremer Adolescent Study, this report presents findings on the frequency, comorbidity, and psychosocial impairment of panic disorder and panic attacks among 1,035 adolescents. The adolescents were randomly selected from 36 schools in the province of Bremen, Germany. Panic disorder and other psychiatric disorders were coded based on DSM-IV criteria using the computerized-assisted personal interview of the Munich version of the Composite International Diagnostic Interview. Panic disorder occurred rather rare, with only 0.5% of all the adolescents met the DSM-IV criteria for this disorder sometimes in their live. Panic attack occurred more frequently, with 18% of the adolescents reported having had at least one panic attack. Slightly more girls than boys had panic attack and panic disorder. The occurrence of panic attack and panic disorder were the greatest among the 14-15 year olds. The experience of having a panic attack was associated with a number of problems, the most frequent being avoiding the situation for fear of having another attack. Four most common symptoms associated with a panic attack were that of palpitations, trembling/shaking, nausea or abdominal distress, and chills or hot flushes. Panic disorder comorbid highly with other psychiatric disorder covered in our study, especially with that of major depression. Among those with a panic disorder, about 40% of them were severely impaired during the worst episode of their illness. Only one out of five adolescents with panic disorder sought professional help for emotional and psychiatric problems. The implication of our findings for research and clinical practice are discussed.     

Application of Millimeter-Wave Radiometry for Remote Chemical Detection

Passive millimeter-wave systems have been used in the past to remotely map solid targets and to measure low-pressure spectral lines of stratospheric and interstellar gases; however, its application to pressure-broadened spectral line detection of industrial emissions is new. We developed a radiative transfer model to determine feasibility and system requirements for passive millimeter-wave spectral detection of terrestrial gases. We designed and built a Dicke-switched multispectral radiometer in the 146-154-GHz band to detect nitric oxide (NO), a prototypical gas of nuclear fuel processing operations. We first tested the spectral detection capability of the radiometer in the laboratory using a gas cell and then field tested it at the Nevada test site at a distance of 600 m from a stack that released hot plumes of NO and air. With features such as Dicke-switched integration, frequent online calibration, and spectral baseline subtraction, we demonstrated the feasibility of remote detection of terrestrial gases by a ground-based radiometer.     

Anterior, posterior, or laparoscopic approach for the management of adrenal diseases?

An important role in the formation of hemostasis defects in uremic patients is attributed to platelet dysfunction. An essential role in platelet structure and function is played by membrane phospholipids (PL). They are asymmetrically distributed within the platelet membrane: outer surface is composed mainly of sphingomyelin (Sph) and phosphatidylcholine (PC). During platelet activation a translocation of phosphatidylserine (PS) and phosphatidylethanolamine (PE) from inner to outer membrane surface is observed. Phosphatidylinositol (PI) is not translocated. Lipid abnormalities are common in uremic patients. According to some authors erythropoietin (EPO) has been reported to alter lipid metabolism. In our recent works a positive influence of EPO on platelet PL composition in uremic patients has been indicated. The aim of this study was the assessment of the EPO influence (applied 4000 U per week) on platelet membrane PL distribution in chronically hemodialyzed patients. The PL distribution was determined using nonpenetrating tracer (TNBS) by Vale method, and using high purified phospholipases hydrolysis according to Chap method. Our results indicate that during EPO therapy the PS, PE, Sph and PC exposition at the outer surface of platelet membrane (in patients hemodialyzed without EPO widely disturbed compared with healthy controls) approaches to normal values. These results confirm our recent observations that EPO profoundly interferes with lipid metabolism. The smaller PS exposition at the outer platelet surface during EPO treatment suggests less platelet activation, and might partially explains the positive EPO influence on platelet hemostasis.     

Unsteady flow through a porous medium with the presence mass transfer

Unsteady flow through a very porous medium with the presence mass transfer is considered. The porous medium is bounded by a vertical plate and this plate absorbs the fluid with a constant velocity. Also the free stream velocity of the fluid vibrates about a mean constant value. The influences of the permeability parameter and the modified Grashof number on the velocity field are discussed.     

Free convection flow of water near 4 °C past a moving plate

In the present study the unsteady free convection flow of water near 4?^°C in the laminar boundary layer over a vertical moving porous plate is investigated. The effect of the suction/injection parameter at the plate on the velocity is considered. The momentum equation is solved numerically by a fourth-order Runge-Kutta scheme. The numerical results which are obtained for the flow are shown graphically.