Der Verfahrensingenieur in der Chemischen Industrie

The role of the chemical engineer in the chemical industry. The principal tasks and activities of the chemical engineers in the chemical industry can be divided into four large areas which are often grouped together from an organizational standpoint: pilot and development engineers are concerned with process development and chemical research, as well as developments relating to chemical engineering unit operations. The task of the plant construction engineer is to build production plant, and the plant engineer is responsible for maintaining the technical standard of the production plant. The work of the chemical engineer in the chemical industry comprises a spectrum of the non-technical tasks which have to be mastered within an engineering framework. Of particular importance is the observation of economic factors. The important subsidiary roles include observation of socioenvironmental conditions, whether of a legislative, social, or human nature. Such knowledge and ability are rarely taught in University courses and have to be acquired in the plant. An increasing demand for chemical engineers is expected in the next few years. The number of new graduates has remained constant for several years and is unlikely to change in the forseeable future.     

Macroscopic Quantum Phenomena in High Critical Temperature Superconducting Josephson Junctions

YBa₂Cu₃O_7?δ grain boundary bi-epitaxial Josepshon junctions (JJs) allow a very clear demonstration of Josephson current variation with the misorientation angle, consistent with the d-wave symmetry of the superconducting order parameter in cuprate, high temperature superconductors. Our bi-epitaxial junctions show a strong suppression of the first harmonic, I ₁ sin ø, of the current phase relation when tunneling from a lobe into a node of the superconducting gap function. In these configurations, the contribution of the second harmonic, I ₂ sin 2ø, becomes of the same magnitude as the first one, giving rise to a characteristic two-well Josephson potential as a function of phase ø instead of the usual single well. This characteristic intrinsic property has suggested proposals of a new class of qu-bit named “quiet” because of the existence a spontaneously degenerate fundamental state without the need of applying an external field. Our experiments probe the macroscopic quantum properties in a d-wave Josephson junction by measuring macroscopic quantum tunneling and energy level quantization. The switching current out of the zero voltage state is measured as a function of temperature down to 20 mK. The temperature variation of the width of an ensemble of switching events goes over from one, which is characteristic of a thermal activation of phase fluctuations to a temperature independent width which is a token of quantum tunneling of the phase. The transition regime is affected by the two-well potential in a 45^° misorientation junction as the second harmonic term gives rise to additional thermal transitions. The difference between quantized energy levels in the harmonic potential was determined by microwave spectroscopy. From the broadening of energy levels, it was possible to extract a Q-value of about 40 for the phase oscillations. The relatively high Q indicates quantum coherence over a sizeable time in d-wave junctions and gives hopes for a realization of a “quiet” high-T _c qu-bit. The contributions of V. L. Ginzburg to several different fields of physics are impressive and long standing. In superconductivity the Ginzburg–Landau theory, for instance, still represents a very powerful approach to model a huge number of different physical systems. High Temperature Superconductors (HTS) have strongly influenced research of the last 20 years and their d-wave order parameter symmetry represents one of the most intriguing features from both the fundamental point of view and some types of innovative long-term applications.     

Alzheimer brain proteins investigated by two-dimensional gel electrophoresis with immobilized pH gradients in the first dimension

Two-dimensional (2-D) gel electrophoresis with immobilized pH gradient 4-8 in the first dimension was applied in the analysis of Alzheimer's disease brain proteins. The silver-stained 2-D maps of extracts from the frontal cerebral cortex were examined. About 800 and 550 protein spots could be observed on the electrophoretograms from the total and buffer-soluble fractions, respectively. In comparing the gels, four protein spots could now be detected which had either been hitherto undetectable (one spot) or which were weaker (two spots) or stronger (one spot) in density (in the controls) [corrected].     

Comparison of the antigen distribution of two US porcine reproductive and respiratory syndrome virus isolates with that of the Lelystad virus

OBJECTIVE: The present study investigates the comorbidity between bulimia nervosa (BN) and the entire range of American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, 3rd rev. ed. (DSM-III-R) personality disorders and controls for the presence of coexisting depression. METHOD: The Personality Disorders Examination (PDE), a structured interview that encompasses all 13 (provisional) DSM-III-R personality disorders, was administered to three groups of subjects: depressed BN patients (n = 15), nondepressed BN patients (n = 15), and nonpsychiatric controls (n = 15). The BN patients were referrals to a dieting disorder unit affiliated with the University of Sydney. They all met DSM-III-R criteria and all had body mass indexes (BMIs) greater than 19. The nonpsychiatric control group were recruited from an undergraduate psychology course. All subjects were given the Bulimic Investigatory Test, Edinburgh (BITE), the Eating Disorders Inventory-2 (EDI-2), the Hamilton Depression Rating Scale (HDRS), and the PDE. RESULTS: 46.7% of depressed BN patients met the criteria for at least one Axis II diagnosis, as assessed by the PDE, and 33.3% of nondepressed BN patients received such a diagnosis, whereas only 6.7% of nonpsychiatric control subjects met this criterion (p < .05). The results of the present study provide support for an increased comorbidity between personality disorders and BN that cannot be attributed to the confounding influence of coexisting depression. DISCUSSION: This finding enables the identification of subgroups of individuals with BN, enabling them to be compared and contrasted. The identification of differences between subgroups may provide information regarding prognosis and differential response to treatment, which could enable more appropriate treatment decisions to be made.     

The efficacy of epinephrine test doses during spinal anesthesia in volunteers: implications for combined spinal-epidural anesthesia

Epinephrine test doses may be administered during combined spinal-epidural anesthesia to determine intravascular placement of epidural catheters. This study was designed to determine systolic blood pressure (SBP) and heart rate (HR) responses to intravenous injection of epinephrine (15 microg) during spinal anesthesia. Twelve volunteers received three spinal anesthetics (lidocaine 100 mg, tetracaine 15 mg, and bupivacaine 15 mg) in a randomized, double blind, cross-over fashion. Epinephrine was administered prior to spinal anesthesia (control), 30 min after injection of spinal anesthesia, and at regression of sensory block to T-10. SBP was measured with a radial arterial catheter and HR with an electrocardiogram. Positive responses were defined as peak increase in SBP > or = 15 mm Hg or HR > or = 20 bpm after injection of epinephrine. Compared with control, peak SBP responses decreased by a mean of 12 mm Hg during spinal anesthesia with tetracaine and bupivacaine (P < 0.05). Peak HR responses decreased by 11 bpm during all three spinal anesthetics (P < 0.05). Incidences of detection of intravenous injection by positive SBP and HR responses ranged from 50% to 100% and were not significantly affected by spinal anesthesia. Spinal anesthesia reduces hemodynamic responses to intravenous epinephrine injection but is unlikely to reduce detection by positive SBP and HR criteria.     

Behavioral biophysics.

Electromagnetic energy is an important factor in the biophysical analysis of the properties and function of living systems. Due to technical advances in electronics, this energy is now being used as a research tool, both by study of its emission by living organisms and also by applying it to the organism. In this paper, the nature of the energy is sketched. Then, data on fingertip detection of color, neural emission of infrared energy, the use of electron paramagnetic resonance techniques to detect neural activity, brain impedance shifts and behavior, and the influence of UHF energy on behavior are considered. It is concluded that, though these areas are in the embryonic stage of development, most are potentially of great significance in the understanding of the nervous system and behavior. (2 p. ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Shrinkage behavior of oriented PVC by thermomechanical analysis

This paper describes a novel application of thermomechanical analysis. Observation and measurement of the thermal recovery of stresses induced in oriented PVC by stretching at elevated temperature is achieved by the modification of a commercial TMA instrument. Employment of an electronic signal differentiation system, in combination with this instrument, permits the simultaneous recording of the rate of shrinkage as a function of temperature. Specific examples are given which demonstrate the performance of the instrument and illustrate its application to problems of practical interest, such as effects of stretching and annealing conditions on shrinkage behavior.     

Teacher–student ethnicity and recommendations for special education referrals.

81 Black, 31 Hispanic, and 87 White teachers responded to a specially constructed case history, in which the ethnic background of the 10th-grade male student was varied, by indicating whether they felt he could be maintained in a classroom or should be referred for specialized services. Results indicate (a) no difference in referral recommendations by the student's ethnic background, (b) mean response differences by the ethnic background of the teacher, and (c) an interaction indicating that teachers responded to the case history by recommending referral of students whose ethnic background was identical to their own less frequently than they did students of other ethnic backgrounds. (4 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

RenderBots—Multi-Agent Systems for Direct Image Generation

The term stroke‐based rendering collectively describes techniques where images are generated from elements that are usually larger than a pixel. These techniques lend themselves well for rendering artistic styles such as stippling and hatching. This paper presents a novel approach for stroke‐based rendering that exploits multi‐agent systems. RenderBots are individual agents each of which in general represents one stroke. They form a multi‐agent system and undergo a simulation to distribute themselves in the environment. The environment consists of a source image and possibly additional G‐buffers. The final image is created when the simulation is finished by having each RenderBot execute its painting function. RenderBot classes differ in their physical behavior as well as their way of painting so that different styles can be created in a very flexible way.