Kinetics of drying polybutylene terephthalate and polyethylene terephthalate granulate

In studying the dynamics of drying of PBT and PET granulate, the parameters of the process that ensure sufficient process stability of their melts were determined. It was found that the rate of self-ordering of structural elements in the polymer substrate in drying is higher in PBT than in PET due to the greater flexibility of the macromolecules. __________ Translated from Khimicheskie Volokna, No. 1, pp. 7–10, January–February, 2006.     

Stress relaxation during the orientation stretch of synthetics fibres

Conclusions Results of investigating structural changes during the process of orientation stretching above the glass point (hot stretching) for a number of thermoplastic fibres have been examined: polyethylene, polypropylene, polyvinyl chloride, chlorine, kapron, nitron, lavsan, vinol, and acetate yarns, plus results of heat-treatments under tension and in the free state. The possibility of describing the relaxation of internal stresses in these fibres in terms of the concept of operating volume has been shown.A correlative determination of the dependence of fibre stress dispersion during the process of orientation stretch and setting the structure of polyester yarn on the dispersion in yarn heat treatments has been established, as well as a dependence of the dispersion of physicomechanical properties on dispersion in fibre tension by steps in the technological process.Translated from Khimicheskie Volokna, No. 3, pp. 29–32, May–June, 1993.     

Physical and Chemical Characteristics and Volatility of PM in the Proximity of a Light-Duty Vehicle Freeway

Abstract

Volatility properties of ultrafine particles were analyzed next to State Route 110 (Pasadena freeway CA), a light-duty vehicle freeway where heavy-duty traffic is prohibited. In addition, mass concentration and chemical composition of particulate matter (PM) were measured in coarse, accumulation, and ultrafine modes. On weekdays from 17 May to 4 June 2004, measurements were performed in two locations, one very close to the freeway (within 2.5 m from the curb) and one at a distance of about 50 m from the freeway. For measurement of mass and chemical composition, the study employed in each location a micro-orifice uniform deposit impactor (MOUDI) and a modified high-volume sampler. Both instruments sampled with the same size cutpoints: a coarse mode from 2.5 to 10 μm, an accumulation mode from 0.18 to 2.5 μm, and an ultrafine mode of particles less than 0.18 μm in aerodynamic diameter. Alternately, a tandem differential mobility analyzer (TDMA) was used at the two sites. A heater between the two DMAs evaporated volatile material from the monodisperse aerosol, size selected by the first DMA. The second DMA analyzed the losses of volatile components. The ultrafine number concentrations next to the freeway were 46,000 cm^?3 on average during the sampling period. The MOUDI ultrafine mass concentration, nitrate, and EC were higher next to the freeway than at the background site farther from the freeway. The other components analyzed in the ultrafine mode had similar concentrations next to the freeway and at the background site. Volatility ranged from about 65% volume losses of 120 nm particles heated to 110°C to 95% of 20 nm particles. The 20 nm aerosol was only internally mixed, whereas increasing nonvolatile fractions were found for 40 nm (6% next to the freeway), 80 nm (20%), and 120 nm (28%) aerosols.     

Analytic and Asymptotic Analysis of Bayesian CramÉr–Rao Bound for Dynamical Phase Offset Estimation

In this paper, we present a closed-form expression of a Bayesian Cramer-Rao lower bound for the estimation of a dynamical phase offset in a non-data-aided BPSK transmitting context. This kind of bound is derived considering two different scenarios: a first expression is obtained in an offline context, and then a second expression in an online context logically follows. The SNR-asymptotic expressions of this bound drive us to introduce a new asymptotic bound, namely the asymptotic Bayesian Cramer-Rao Bound. This bound is close to the classical Bayesian bound but is easier to evaluate.     

Cardiothermographic assessment of arterial and venousrevascularization

High blood-flow rate and considerable metabolic activity render the myocardium a possible candidate for infrared (IR) imaging. Cardiothermography is the term used for recording the heart surface temperature. It is a useful tool in monitoring coronary perfusion through epicardial heat emission changes. Elevated heat-emission indicates increased coronary blood flow, while decreased emission represents hypoperfusion. The aim of our study is the early intraoperative cardiothermographic evaluation of arterial and venous bypass graft patency and the quantitative assessment of the temperature changes of the revascularized area. Infrared imaging was complemented by electromagnetic flow measurements on the venous grafts     

Evaluation of the vegetable oil taken up into the duodenum as a factor in pancreozymin liberation in healthy persons and in digestive organ diseases

Investigations carried out in 14 healthy volunteers, 29 patients with chronic pancreatitis and 15 patients with chronic hepatitis showed that infusion into the duodenum of an optimally tolerable quantity (25 ml) of vegetable oil makes for a release of an amount of pancreozymin, which, by the criterion for stimulating secretion of pancreatic amylase, is equivalent to 0.5 Un/kg of pure preparation of pancreozymin and, as to the degree of stimulating the secretion of lipase and trypsin, it exceeds the effect of 0.5 Un/kg, but is less than that of 1.5 Un/kg of pure pancreozymin. These data should be taken into account in evaluating the ability of some alimentary fats to stimulate the release of endogenous pancreozymin.     

Conducting psychotherapy with psychotherapists: I. Prevalence, patients, and problems.

Examines responses from 349 psychologists of the American Psychological Association (APA) Division of Psychotherapy who completed a questionnaire regarding the prevalence of treating fellow psychotherapists, the type of psychotherapist-patients they treated, and the stressors and satisfactions of conducting such work. Three fourths of respondents related that they had treated mental health professionals and professionals-in-training over the past 3 years, and that this population constituted 3% to 796 of their caseloads. Nearly all of the therapist-patients were self-referred, and 85% received individual therapy. The psychotherapist-patients tended to be psychologists (37%) or social workers (29%) of diverse theoretical traditions, with the exception of biologically oriented clinicians. Satisfactions clustered around pleasures inherent in doing meaningful work, acknowledgment by peers, and the opportunity to help therapist-patients enhance their own clinical effectiveness. Predominant stressors concerned evaluation anxieties in treating colleagues and in the related belief that colleagues are more challenging and resistant to change. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

THE TRANSVERSE STRENGTH OF FIRE-CLAY TILES AT FURNACE TEMPERATURES1

Commercial fire-clay tiles, were tested at furnace temperatures, for transverse strength. This was supplemented by tests of tiles of known composition made in the laboratory. Moduli of rupture obtained varied from 245.5 pounds per square inch at 1275°C, to 28.9 pounds per square inch at 1350°C but the data collected do not warrant definite conclusions.