Stochastic magnetic actuated random transducer devices based on perpendicular magnetic tunnel junctions

True random number generators are of great interest in many computing applications such as cryptography, neuromorphic systems and Monte Carlo simulations. Here we investigate perpendicular magnetic tunnel junction nanopillars (pMTJs) activated by short duration (ns) pulses in the ballistic limit for such applications. In this limit, a pulse can transform the Boltzmann distribution of initial free layer magnetization states into randomly magnetized down or up states, i.e. a bit that is 0 or 1, easily determined by measurement of the junction's tunnel resistance. It is demonstrated that bitstreams with millions of events: 1) are very well described by the binomial distribution; 2) can be used to create a uniform distribution of 8-bit random numbers; 3) pass multiple statistical tests for true randomness, including all the National Institute of Standards tests for random number generators with only one XOR operation; and 4) can have no drift in the bit probability with time. The results presented here show that pMTJs operated in the ballistic regime can generate true random numbers at GHz bitrates, while being more robust to environmental changes, such as their operating temperature, compared to other stochastic nanomagnetic devices.Comment: 8 pages, 3 figures, 2 tables, will be submitted to peer-reviewed journa

Treatment and long-term outcome in primary nephrogenic diabetes insipidus

Background: Primary nephrogenic diabetes insipidus (NDI) is a rare disorder and little is known about treatment practices and long-term outcome. Methods: Paediatric and adult nephrologists contacted through European professional organizations entered data in an online form. Results: Data were collected on 315 patients (22 countries, male 84%, adults 35%). Mutation testing had been performed in 270 (86%); pathogenic variants were identified in 258 (96%). The median (range) age at diagnosis was 0.6 (0.0–60) years and at last follow-up 14.0 (0.1–70) years. In adults, height was normal with a mean (standard deviation) score of −0.39 (±1.0), yet there was increased prevalence of obesity (body mass index >30 kg/m2; 41% versus 16% European average; P < 0.001). There was also increased prevalence of chronic kidney disease (CKD) Stage ≥2 in children (32%) and adults (48%). Evidence of flow uropathy was present in 38%. A higher proportion of children than adults (85% versus 54%; P < 0.001) received medications to reduce urine output. Patients ≥25 years were less likely to have a university degree than the European average (21% versus 35%; P = 0.003) but full-time employment was similar. Mental health problems, predominantly attention-deficit hyperactivity disorder (16%), were reported in 36% of patients. Conclusion: This large NDI cohort shows an overall favourable outcome with normal adult height and only mild to moderate CKD in most. Yet, while full-time employment was similar to the European average, educational achievement was lower, and more than half had urological and/or mental health problems

Experimental measurement of flow past cavities of different shapes

Experiments are carried out in order to investigate the flow structure past a rectangular, triangular and semi-circular cavity of length-to-depth ratio of 2:1 using the Particle Image Velocimetry (PIV) technique. The experiments are performed in a large scale water channel with three different upstream velocities resulting in Reynolds numbers of 1230, 1460 and 1700, based on inflow momentum thickness, for each cavity type. Contours of constant averaged streamwise and transverse components of velocity, contours of constant averaged vorticity, Reynolds stress and streamline plots for each cavity type for the aforementioned three Reynolds numbers are presented. In addition, streamwise velocity, Reynolds stress and turbulence intensity values are compared for all cavity types. Effect of cavity shape on flow structure within the cavity is discussed in detail. Moreover, spectrum of instantaneous streamwise velocity fluctuations in shear layer near the downstream of the leading corner and the upstream of the trailing corner of the cavities are obtained and it was found that no organized oscillations are present in the flow; rectangular and triangular cavities have the largest amplitudes while semi-circular cavity has the smallest. Calculated turbulence intensities also reveal that the maximum turbulence intensities occur at cavity lid in the centerline section and rectangular and triangular cavities have larger turbulence intensity compared to semi-circular cavity. © 2009 Elsevier Inc. All rights reserved

Effect of impeller-diffuser radial gap ratio in a centrifugal pump

In this study, effects of flow behavior in a non-traditional centrifugal pump, whose diffuser was subjected to different radial gaps, were investigated numerically using multi-purpose FLUENT code. Flow was assumed to be three dimensional, viscous and incompressible. ?-? RNG with standard near-wall functions was used. Centrifugal pump had a five backward curved-bladed impeller running at 890 rpm and a nine vaned diffuser. Investigations for three different radial gaps (10%, 15%, 20%) have been carried out for 15 different volume flow rates. For present pump, 20% radial gap is found most suitable for pressure fluctuations

PIV measurements of flow through a sudden contraction

Flow through a sudden contraction occurs in a variety of engineering applications including injection moulding, extrusion, thermoforming and many polymer melt processing applications. Instabilities observed during polymer melts processing can have an important limiting factor affecting production rates in many industrial area. Analysis of contraction flow is a useful process to identify these defects. In this study, the flow of a Newtonian fluid in an axisymmetrical 4:1 sudden contraction geometry is studied using quantitative flow visualization and Particle Image Velocimetry (PIV) technique. The flow is driven by the effect of gravity under atmospheric conditions in room temperature. Study of the Newtonian entrance problem is useful precursor to the study of the entrance behaviour of viscoelastic fluids. Time averaged and instantaneous velocity vector maps of the flow field, time-averaged velocity and vorticity contours as well as axial and radial velocity profiles right above the contraction for different Reynolds numbers are presented. © 2007 Elsevier Ltd. All rights reserved.Firat University Scientific Research Projects Management Unit: MMF2004BAP15This work was supported by Cukurova University Scientific Research Projects Unit under the grant number MMF2004BAP15 granted to the second author (A. Pinarbasi)

Endothelial dysfunction in renal transplant patients is closely related to serum cyclosporine levels

Background. Cyclosporine (CsA), one of the standard agents used in renal transplant recipients, has been considered to cause endothelial dysfunction and to contribute to arterial complications posttransplant. Since concentration-dependent effects of CsA on endothelial functions in humans have not been examined, this study was performed to investigate this relationship

Infliximab in inflammatory bowel disease: attention to adverse events

OBJECTIVE: To assess the efficacy and adverse effects of infliximab in patients with Crohn's disease and ulcerative colitis who are resistant to conventional therapy or having fistulising type Crohn's disease