An Asymptotic Preserving Method for Linear Systems of Balance Laws Based on Galerkin’s Method

We apply the concept of asymptotic preserving schemes (SIAM J Sci Comput 21:441–454, 1999) to the linearized \(p\) -system and discretize the resulting elliptic equation using standard continuous Finite Elements instead of Finite Differences. The fully discrete method is analyzed with respect to consistency, and we compare it numerically with more traditional methods such as Implicit Euler’s method.     

Transverse mixing and heat transfer in horizontal rotary drum reactors

The transverse mixing of quartz sand (mean particle sizes 157, 323, 794 and 1038 μm) and sodium carbonate (soda) (mean particle size 137 μm) has been investigated in a laboratory rotary drum reactor of 300 mm length and 310 mm diam. Solid movement in the drum was observed by means of colored tracers and successive exposures as well as by means of hot tracers and recording the local temperature in the bulk of particles. Three different types of the particles and bulk behaviour could be observed for stickly particles. The time constant of the mixing was estimated as a function of the rotational speed of the drum. The “cooling-down” curves of the bulk of particles were measured in a laboratory oven of 250 mm diam. and 600 mm length. The temperature variation as a function of the time can be described by the Newtonian cooling law, from which the heat transfer coefficient at the wall α_w was estimated.The absolute value of α_w's and their dependence on the contact time and particle diameter cannot be calculated by the heat penetration model, which disregards the film resistance at the bulk/wall contact. By taking into account this resistance a good quality of fitting can be achieved.     

机械总院研发立式冷摆动辗压机填补国内空白

机械科学研究总院北京机电研究所承担“2000KN立式冷摆动辗压机开发研究”项目通过验收,研发的2000kN矿式冷摆动辗压机具有自主知识产权,填补了国内空白,达到国际先进水平,人选“2013度中关村科技园区首台（套）重大技术装备试验、示范项目。     

Prevalence and incidence of hand dermatitis in hairdressing apprentices: results of the POSH study. Prevention of occupational skin disease in hairdressers

OBJECTIVE: Occupational skin changes in hairdressers are very common. Morbidity, however, has not yet been quantified precisely. METHODS: A cohort of 2,352 hairdressing apprentices (of the 2,570 invited to participate, i.e., 91.5% response) was prospectively followed for the duration of their vocational training (3 years) by three examinations. Three waves (years) were recruited in 1992, 1993, and 1994 from 15 vocational training schools in northwestern Germany. RESULTS: The point prevalence of (mostly slight) irritant skin changes of the hands increased from 35.4% in the initial examination to 47.5% in the intermediate examination and to 55.1% in the final examination. Given a more conservative definition of a case of "hand dermatitis," these estimates were 12.9%, 23.5%, and 23.9%, respectively. Altogether, 34.3 and 15.2 cases of "skin changes (any degree)" and "hand dermatitis," respectively, in 100 person-years were observed during the study period. The incidence rate, i.e., the number of newly diseased study participants in relation to the person-time at risk contributed, decreased in the course of the study. The proportion of dropouts until final follow-up was 51.8%. CONCLUSION: The present results appear to lie in a range with those found in other, much smaller cohort studies. However, comparison of the results is hampered either by the lack of a clear definition or by a different definition of "person-time at risk" or "a case of hand dermatitis." As compared with an external control group of office apprentices, the incidence was several times higher in hairdressing apprentices, which points to the high risk for skin damage in this occupation.     

Pulmonary infiltrates in neutropenic patients with acute leukemia during chemotherapy: outcome and prognostic factors

STUDY OBJECTIVE: To determine predictors of mortality from pulmonary infiltrates in neutropenic patients with acute leukemia during chemotherapy, and the significance of those factors related to the underlying malignancy and its therapy as well as of those related to the severity of the illness associated with pulmonary infiltrates. DESIGN: A historical cohort study. SETTING: A university teaching hospital and tertiary referral center. PATIENTS AND METHODS: Overall, 53 patients with neutropenia during chemotherapy and with first episodes of pulmonary infiltrates during a 4-year period were studied. Prognostic analysis included 38 variables. Multivariate analyses were performed by logistic regression. RESULTS: The survival rate from pneumonia was 57% (30/53). The following eight parameters were significantly associated with death in univariate analysis: comorbidity present; development of "late" pulmonary infiltrates (> or = 14 days after hospital admission); heart rate > or = 100 beats/min; a ratio heart rate/systolic blood pressure (HR/SBP) > or = 1.2; urea nitrogen > 7 mmol/L; radiographic score > or = 3; neutropenia < 1.0x10(9)/L at the treatment end point; and failed complete remission. In a multivariate model including only parameters available at diagnosis of pulmonary infiltrates, the presence of a ratio HR/SBP > or = 1.2 and of a radiographic score > or = 3 remained independently associated with death. In a second model also including the evolutionary parameter neutropenia < or = 1.0x10(9)/L at the treatment end point, both parameters remained significant together with neutropenia <1.0x 10(9)/L at the treatment end point. The presence of a ratio HR/SBP > or = 1.2 was a strong marker of early death. CONCLUSION: Both therapy- and malignancy-associated neutropenia as well as the severity of illness associated with pulmonary infiltrates are independent prognostic factors. Patients with a ratio HR/SBP > or = 1.2 at diagnosis of pulmonary infiltrates suffer from potentially reversible acute illness, are at risk for early death and, therefore, may be appropriate candidates for treatment in an ICU.     

The metabolism of fenazox in tomato plants

Results from investigations on the metabolism of 14C-Fenazox show that in 6-8 weeks old tomato-plants (sort "Harzfeuer") the agent undergoes a biotransformation. After chromatographic separation the structure of the biotransformation products was elucidated by comparison to authentic test substances, by derivatization as well as by means of physico-chemical methods. With that, the following metabolites were identified: non-transformed Fenazox, o-hydroxyazobenzene, o-hydroxyaniline, and p-hydroxyaniline. Probably, the agent is first transformed enzymatically or non-enzymatically into o-hydroxyazobenzene, then follows a reductive cleavage into o-hydroxyaniline and aniline. In its turn, the latter is transformed into o-hydroxy- and p-hydroxyaniline. Experiments in the field of transformation kinetics indicated that the concentration of the applied Fenazox rapidly decreases and that the first transformation product o-hydroxyazobenzene in the beginning increases and then again decreases in its concentration. With increasing application time it comes to an increase of the non-extractable residues.     

Magnetization and torque measurements on rotating niobium cylinders and ellipsoids

The magnetization and torque of niobium samples of different shapes rotating in a magnetic field are studied with emphasis on the behavior near the upper critical field H _c2. The observed rotational magnetization is free of hysteresis and is found to represent a good approximation to the thermodynamic equilibrium magnetization of the samples if pinning is not too strong and the frequency of rotation is sufficiently low. The viscous contribution to the torque exhibits a step at H _c2whose dependence on sample geometry is in good agreement with predictions derived under the simple assumption of a homogeneous arrangement of parallel straight vortices in the rotating sample.     

The influence of the extraction voltage on the energetic electron population of an electron cyclotron resonance ion source plasma

An influence of the extraction voltage on the high energy slope of bremsstrahlung radiation spectra has been reported in ECRIS experiments, which is not well understood so far. In order to provide more detailed data on this effect, we have measured bremsstrahlung radiation spectra accompanying especially the evolution of highly charge ions (i.e., by monitoring the Ar(14+) charge state) as the extraction voltage is changed from 0 to 20 kV, in dedicated experiments at the Frankfurt 14 GHz-ECRIS.     

Double contrast examination of the stomach. Definition, technic and indications

Double contrast examination constitutes an important element in radiological gastric examination. The author examines the history of the term "double contrast" and defines the designation of "double contrast examination". The exclusive use of the double contrast method reduces the diagnostic value of gastric X-ray examinations. Thus a method is suggested that will avoid the disadvantages of exclusive double contrast examination while adequately including double contrast in the gastric examination. This is done by using various methods - according to the problem posed - in order to achieve the double contrast.     

Cracking in and around the thermally grown oxide in thermal barrier coatings: A comparison of isothermal and cyclic oxidation

In the present paper the time and temperature dependent evolution of the microstructure of TBC systems and especially of post-experimentally determined physical defects in and around the TGO for both isothermal and cyclic exposure conditions are investigated. Specimens with APS- as well as with PVD-topcoats have been oxidised between 950 and 1100°C up to a maximum duration of 5000 h followed by extensive scanning electron microscopy and subsequent interactive image analysis to measure the maximum crack lengths in and around the TGO. These cracks are additionally classified with respect to their local orientation in the TGO or its vicinity. The results of isothermal and cyclic test conditions show a number of similarities in results e.g. an unsystematic occurrence of inwardly growing, “cauliflower like” oxide or the most frequently occurring type of cracks in APS systems. Nevertheless substantial differences concerning the final failure, microstructure, crack growth behaviour and finally life time of the component between isothermal and cyclic test conditions exist. Some indications were found, that for this particular bond coat occurance of inwardly growing oxide intrusions increases the adherence of the TGO.