From Neweul to Neweul-M<Superscript>2</Superscript>: symbolical equations of motion for multibody system analysis and synthesis

The state-of-the-art for deriving symbolical equations of motion for multibody systems is reviewed. The fundamentals of formalisms based on Newton–Euler equations are presented and the recent development of a research software called Neweul-M² is highlighted. The modeling approach with commands and a graphical user interface are discussed as well as system analysis options, control design by export to Matlab/Simulink, and parameter optimization for system synthesis. The alternatives within the program using symbolic and numeric approaches are emphasized. A double pendulum is used to explain the program features and a vehicle benchmark model is presented as an example. Advanced applications include closed kinematic loops and flexible bodies.     

Case study on the implementation of deammonification for the process water treatment of Munich WWTPs

The two-staged WWTP 'Gut Grosslappen' has a capacity of 2 mio. PE. It comprises a pre-denitrification in the first stage using recirculation from the nitrifying second stage. A residual post-denitrification in a downstream sand filter is required in order to achieve the effluent standards. Presently the process water from sludge digestion is treated separately by nitrification/denitrification. Due to necessary reconstruction of the biological stages, the process water treatment was included in the future overall process concept of the WWTP. A case study was conducted comparing the processes nitritation/denitrititation and deammonification with nitrification/denitrification including their effect on the operational costs of the planned main flow treatment. Besides the different operating costs the investment costs required for the process water treatment played a significant role. Six cases for the process water treatment were compared. As a result, in Munich deammonification can only be recommended for long-term future developments, due to the high investment costs, compared with the nitritation/denitritation alternative realizable in existing tanks. The savings concerning aeration, sludge disposal and chemicals were not sufficient to compensate for the additional investment costs. Due to the specific circumstances in Munich, for the time being the use of existing tanks for nitritation/denitritation proved to be most economical.     

Impact of Marangoni effects on the apparent contact angle — a numerical investigation

The influence of thermocapillary stress on the shape of the gas-liquid phase boundary is investigated numerically. We consider the case of a cold liquid meniscus at a heated solid wall in the absence of gravity. An “apparent contact angle” is defined geometrically and the deviation of this apparent contact angle from the prescribed static contact angle due to thermocapillary convection is studied. We observe an enlarged apparent contact angle compared to the isothermal case. Since a fixed static contact angle is used in the computations, we emphasize that this effect does not depend on the specific model of a dynamic contact angle.     

Metallchelate ungesättigter 1,2-Dithioäther

Metal Chelates of Unsaturated 1,2-Dithioethers The dialkyl- and diaralkyldithioethers of ethylenebisthiol (edt) and xylenedithiol form cationic 1:2 chelates with the d⁸-metal ions Ag^I and Cu^I, which have been isolated and characterized. Pd^II- and Pt^II-halides yield neutral mixed ligand complexes of the type Me (L L) X₂ (L L = dithioether, X = halogen). The dibenzyldithioether of edt is cleaved oxidatively by Cu^II and yields dibenzyldisulfide, Cu^I and an unidentified product.     

Changes in endocrine profile and reproductive organs during puberty in the male marmoset monkey (Callithrix jacchus)

Data on pubertal maturation in male marmoset, a model for human reproduction, are scant and conflicting. We collected data on novel parameters to characterize puberty. Twenty-five marmoset monkeys were assigned to five age groups by weeks (wk): 21 (pre-pubertal), 43 (onset of puberty), 52 (fully pubertal), 70 (mature), and 116 (fully adult). Serum and intratesticular testosterone and pituitary bioactive chorionic gonadotropin (bioCG) were measured. Testicular development was assessed by ultrasonography, histology, and flow cytometry. Three consecutive blood samples revealed extreme fluctuations in testosterone concentrations, suggesting an erratic secretion. Age-related changes in serum testosterone and pituitary bioCG concentrations were observed. Intratesticular androgens (ITAs) showed high fluctuations within groups at all ages and were high in some animals by 21 wk. Unexpectedly, no correlation between pituitary bioCG and serum testosterone or ITAs was found, but these parameters significantly correlated with testicular weight and volume. These observations were consistent a dependence on the testis growth on bioCG. Unfortunately, the low serum levels of bioCG were not measurable in this study. At 43 wk, the animals reached puberty. At 52 wk of age, animals attained maximum body and epididymal weights and qualitatively normal spermatogenesis, but testes continued growing, reaching a maximum of all parameters at 70 wk of age, without further major changes at the age of 116 wk. It is concluded that (1) gonadal activation is evident at wk 21, (2) the male marmoset reaches the pubertal threshold around 43 wk of age, attains qualitative parameters at 52 wk, matures further to sexual maturity at 70 wk, and (3) serum testosterone and ITAs are highly variable without any identifiable correlation with pituitary bioCG.     

Analysis of free amino acids in green coffee beans

To investigate amino acid changes in green coffee beans in the post-harvest period, amino acid concentrations were determined in green beans and after modelled drying, fermentation and storage. After the drying at alternating temperatures up to maximally 40°C, considerable changes in the concentrations of individual amino acids were identified. At the beginning of the storage period, significant changes in concentration were found to a minor extent. Under the condition of drying, it was mainly the concentration of glutamic acid that changed considerably. There was an increase in all the samples by 500 mg/kg dry matter on average, which corresponds to an increase of about 50% of the original value. In contrast, the concentration of aspartic acid in most of the samples decreased clearly due to drying. For the predominant part of the coffee samples, there was a significant increase in the hydrophobic amino acids Val, Phe, Ile and Leu. Changes of the quantities of other amino acids were non-uniform and only insignificant. Constant drying at 80°C for most of the amino acids brought about only minor concentration changes compared to those values obtained at 40°C. Modelled fermentation had no significant effect on the concentrations of the individual amino acids. After a 4-week storage of dried beans, amino acid concentrations did not change further. It is very possible that different post-harvest treatment parameters may influence the amount of aroma precursor compounds in the coffee beans.     

A double-blind multicenter trial comparing sertraline and citalopram in patients with major depression treated in general practice

The purpose of this double-blind, multicenter trial was to compare the efficacy and safety of sertraline (50-150 mg/day) with those of citalopram (20-60 mg/day) in patients with major depression in general practice during 24 weeks of treatment. The patients were assessed using the Montgomery-Asberg Depression Rating Scale and the Clinical Global Impressions of severity and improvement scales. Observed and spontaneously reported adverse events were recorded and side-effects were assessed by means of the UKU Side-Effect Scale. Altogether 400 patients were randomized into the study. A total of 308 patients completed the 24-week study in accordance with the protocol. A significant reduction in the total Montgomery-Asberg Depression Rating Scale scores was observed in both treatment groups as early as 2 weeks, with no statistically significant differences between the drugs. In the intention to treat-last observation carried forward analysis 76% responded to treatment in the sertraline and 81% in the citalopram group. The final mean doses were 82 mg/day (64% higher than baseline) in the sertraline group and 34 mg/day (70% higher than baseline) in the citalopram group. The response rate in completers in accordance with protocol was 90% in the sertraline group and 93% in the citalopram group. The side-effects were those usually seen, and both sertraline and citalopram were considered to be well tolerated. It was concluded that patients with major depression in general practice respond well to 24 weeks of treatment with sertraline or citalopram. With regard to efficacy, no statistically significant differences were found between the drugs.