PTC thermistor protects multiloaded power supplies

A PTC /Positive-Temperature-Coefficient/ thermistor placed in series with each branch load of a multiload circuit prevents power loss in parallel branches. This thermistor may be used in any circuit requiring current limiting or intended overload resetting

Perfectionism, alcohol intoxication, and deliberate self-harm in men and women

Previous research has demonstrated associations between deliberate self-harm (DSH) and perfectionism, although most of that research used retrospective self-report measures of DSH, which are prone to various cognitive biases. Although perfectionism has been associated with alcohol abuse, no research has examined how alcohol intoxication may moderate the relation between perfectionism and DSH. The aims of this experimental study were to determine if perfectionism is associated with a laboratory analogue of DSH (the Self-Aggression Paradigm) and examine the role of alcohol intoxication as a potential moderator. Using archival data, blood alcohol content (BAC) was manipulated by randomly assigning participants to reach one of four target BACs. Results indicated that perfectionism was not associated with DSH (mean self-administered shock or number of “severe” shocks). There was no interaction between perfectionism and BAC. These findings are discussed within the context of the perfectionism measure’s psychometric characteristics and the strength of previous research findings

Optimisation of confinement in a fusion reactor using a nonlinear turbulence model

The confinement of heat in the core of a magnetic fusion reactor is optimised using a multidimensional optimisation algorithm. For the first time in such a study, the loss of heat due to turbulence is modelled at every stage using first-principles nonlinear simulations which accurately capture the turbulent cascade and large-scale zonal flows. The simulations utilise a novel approach, with gyrofluid treatment of the small-scale drift waves and gyrokinetic treatment of the large-scale zonal flows. A simple near-circular equilibrium with standard parameters is chosen as the initial condition. The figure of merit, fusion power per unit volume, is calculated, and then two control parameters, the elongation and triangularity of the outer flux surface, are varied, with the algorithm seeking to optimise the chosen figure of merit. A two-fold increase in the plasma power per unit volume is achieved by moving to higher elongation and strongly negative triangularity.Comment: 32 pages, 8 figures, accepted to JP

Automatic solar lamp intensity control system

System that substitutes solar cells directly in the path of the radiation incident on the test volume and uses a dc bridge-null system was developed. The solar cell is affixed to a heat sink mounted on each of three arms for each solar lamp. Control of the radiation from the solar lamps is automatic

Water Delivery and Giant Impacts in the 'Grand Tack' Scenario

A new model for terrestrial planet formation (Hansen 2009, Walsh et al. 2011) has explored accretion in a truncated protoplanetary disk, and found that such a configuration is able to reproduce the distribution of mass among the planets in the Solar System, especially the Earth/Mars mass ratio, which earlier simulations have generally not been able to match. Walsh et al. tested a possible mechanism to truncate the disk--a two-stage, inward-then-outward migration of Jupiter and Saturn, as found in numerous hydrodynamical simulations of giant planet formation. In addition to truncating the disk and producing a more realistic Earth/Mars mass ratio, the migration of the giant planets also populates the asteroid belt with two distinct populations of bodies--the inner belt is filled by bodies originating inside of 3 AU, and the outer belt is filled with bodies originating from between and beyond the giant planets (which are hereafter referred to as `primitive' bodies). We find here that the planets will accrete on order 1-2% of their total mass from primitive planetesimals scattered onto planet-crossing orbits during the formation of the planets. For an assumed value of 10% for the water mass fraction of the primitive planetesimals, this model delivers a total amount of water comparable to that estimated to be on the Earth today. While the radial distribution of the planetary masses and the dynamical excitation of their orbits are a good match to the observed system, we find that the last giant impact is typically earlier than 20 Myr, and a substantial amount of mass is accreted after that event. However, 5 of the 27 planets larger than half an Earth mass formed in all simulations do experience large late impacts and subsequent accretion consistent with the dating of the Moon-forming impact and the estimated amount of mass accreted by Earth following that event

Role of plasma arginine vasopressin in the impaired water diuresis of isolated glucocorticoid deficiency in the rat

Role of plasma arginine vasopressin in the impaired water diuresis of isolated glucocorticoid deficiency in the rat. The role of antidiuretic hormone in the impaired water excretion of isolated glucocorticoid deficiency was investigated in the thyroxin-re-placed, anterior hypophysectomized rat. Hypophysectomized rats demonstrated marked impairment in the excretion of an oral water load (32 ± 4% vs. 94 ± 4%), plasma hypoosmolality (281 ± 2 vs. 289 ± 2 mOsm/kg), and hyponatremia (129 ± 1 vs. 140 ± 1 mEq/liter) compared to controls (all P < 0.001). These defects were associated with increased levels of plasma arginine vasopressin (3.05 ± 0.45 vs. 1.38 ± 0.11 pg/ml; P < 0.001). Following physiologic corticosterone replacement in hypophysectomized rats, the percentage of the water load excreted, free water clearance, plasma sodium, plasma osmolality, and circulating levels of plasma arginine vasopressin were all restored to control values. This correction of water diuresis occurred in the absence of changes in GFR or solute excretion. The defect in water excretion and the elevation of plasma arginine vasopressin could not be corrected by chronic extracellular volume expansion in the absence of glucocorticoid replacement. It is concluded that (a) increased secretion of vasopressin plays an important role in the impaired water diuresis of isolated glucorticoid deficiency; (b) physiologic corticosterone replacement corrects both the impaired water excretion and the increased secretion of vasopressin associated with glucocorticoid deficiency; and (c) a volume-independent nonosmotic stimulus to vasopressin secretion may be activated by the chronic absence of glucocorticoid hormones.Rôle de l'rginine vasopressine du plasma dans l'ncapacite de diluer l'urine au cours du déficit isolé en glucocorticoïdes chez le rat. Le rôle de l'hormone antidiurétique dans l'incapacité à diluer l'urine au cours du déficit isolé en glucocorticoïdes a été étudié chez des rats ayant subi une hypophysectomie antérieure et compensés par de la thyroxine. Les rats hypohysectomisés ont un déficit important de l'excrétion d'une charge en eau (32 ± 4% contre 94 ± 4%), une hypoosmolalité plasmatique (281 ± 2 contre 289 ± 2 mOsm/kg), et une hyponatrémie (129 ± 1 contre 140 ± 1 mEq/liter), par comparaison aux contrôles (P < 0,001). Ces modifications sont associées à des concentrations plasmatiques élevées d'arginine vasopressine (3,05 ± 0,45 contre 1,38 ± 0,11 pg/ml; P < 0,001). L'administration de corticostérone aux rats hypophysectomisés ramène aux valeurs contrôles le pourcentage de la charge d'eau excrétée, la clearance de l'eau libre, la natrémie, l'osmolalité plasmatique et la concentration circulante d'arginine vasopressine. Cette restauration de la diurèse aqueuse est observée en l'absence de modifications du débit de filtration glomérulaire ou du débit urinaire de substances dissoutes. Le déficit d'excrétion de l'eau et l'augmentation de l'arginine vasopressine du plasma ne peuvent pas être corrigés par une expansion chronique du volume extra-cellulaire en l'absence de traitement substitutif par les glucocorticoïdes. I1 est conclu que: (a) l'augmentation de la sécrétion de vasopressine joue un rôle important dans l'incapacité de diluer les urines observée au cours du déficit en glucocorticoïdes; (b) un traitement substitutif par des doses physiologiques de corticostérone corrige à la fois le déficit d'excrétion de l'eau et la sécrétion excessive de vasopressine associés au déficit en glucocorticoïdes; et (c) un stimulus, non osmotique et indépendant du volume extracellulaire, de la sécrétion de vasopressine peut être activé par l'absence chronique d'hormones glucocorticoïdes