Design optischer Schichtsysteme

A logical approach to optical coatings, their design, manufacture, properties and application would be the dream of all users. Optical coatings are thought to be rather mysterious with the unexpected the norm and success depende? How can it be manufactured in large numbers of items under real conditions reproducibly and profitable? The article is a mixture of fundamental optics and practical design examples. The objective is the presentation of a logical unified treatment of the subject with emphasis throughout on understanding and reasoning.     

The Novel Cardiac Myosin Activator Danicamtiv Improves Cardiac Systolic Function at the Expense of Diastolic Dysfunction In Vitro and In Vivo: Implications for Clinical Applications

Recent cardiotropic drug developments have focused on cardiac myofilaments. Danicamtiv, the second direct myosin activator, has achieved encouraging results in preclinical and clinical studies, thus implicating its potential applicability in the treatment of heart failure with reduced ejection fraction (HFrEF). Here, we analyzed the inotropic effects of danicamtiv in detail. To this end, changes in sarcomere length and intracellular Ca²⁺ levels were monitored in parallel, in enzymatically isolated canine cardiomyocytes, and detailed echocardiographic examinations were performed in anesthetized rats in the absence or presence of danicamtiv. The systolic and diastolic sarcomere lengths decreased; contraction and relaxation kinetics slowed down with increasing danicamtiv concentrations without changes in intracellular Ca²⁺ transients in vitro. Danicamtiv evoked remarkable increases in left ventricular ejection fraction and fractional shortening, also reflected by changes in systolic strain. Nevertheless, the systolic ejection time was significantly prolonged, the ratio of diastolic to systolic duration was reduced, and signs of diastolic dysfunction were also observed upon danicamtiv treatment in vivo. Taken together, danicamtiv improves cardiac systolic function, but it can also limit diastolic performance, especially at high drug concentrations.     

Resource allocation with project management software

We present results of a benchmark test evaluating the resource allocation capabilities of the project management software packages Acos Plus.1 8.2, CA SuperProject 5.0a, CS Project Professional 3.0, MS Project 2000, and Scitor Project Scheduler 8.0.1. The tests are based on 1560 instances of precedence– and resource–constrained project scheduling problems. For different complexity scenarios, we analyze the deviation of the makespan obtained by the software packages from the best feasible makespan known. Among the tested software packages, Acos Plus.1 and Project Scheduler show the best resource allocation performance. Moreover, our numerical analysis reveals a considerable performance gap between the implemented methods and state–of–the–art project scheduling algorithms, especially for large–sized problems. Thus, there is still a significant potential for improving solutions to resource allocation problems in practice.      

Bemessung und Überwachung einer geokunststoffbewehrten Tragschicht auf HSP‐Pfählen

Design and monitoring of a geosynthetic reinforced base‐layer on HSP‐piles. A four‐field fly‐over and the access dam for a double‐track railway line and a bicycle path has been constructed to cross a motorway in a suburb of Rotterdam. The access dam is up to 8.5 m high and was constructed with a slope of 1:2 leading to the preferred small construction width. In spite of the underground conditions with very low shear strength a short‐term traffic initiation as well as low long‐term maintenance cost was demanded. In close collaboration between the contracting authority, the geotechnical consultant CRUX Engineering BV and the construction company Voorbij Funderingstechniek BV a flexible foundations system was developed. Advantages of the chosen system are the possibility top bridge differential settlement, adjust it to the local subsoil conditions and minimise disturbance of the adjacent recreation area. To transfer the self weight and the traffic load into sand layers with higher bearing capacity a combination of Voton HSP‐ piles (high speed piles) and an overlying load distributing geosynthetic stabilised soil layer has been constructed. This innovative combination enables high economic efficiency and an optimised load transfer in the subsoil. A geotechnical monitoring program has been installed to verify that the acting loads on the construction elements are not higher than the allowable loads.     

Photochemische Reaktionen von Pyrazolidon-(3)-betainen. IV. Photooxydation von Pyrazolidon-(3)-azomethiniminen

Photochemical Reactions of 3-Pyrazolidone Betains. IV. Photooxidation of 3-Pyrazolidone Azomethinimines Azomethinimines 1 , easily obtainable from 3-pyrazolidone and aldehydes, on dyesensitized photooxidation in methanol as a solvent undergo decomposition to nitrogen, methyl β-methoxypropionate 3 , methyl acrylate 4 and the corresponding aldehyde 2 . The formation of these products is interpreted by formation and decomposition of a cyclic peroxide 5 , produced by a 1,3-dipolar cycloaddition reaction between 1 and singlet oxygen. The photooxidation of 1 in acetonitrile produces: nitrogen, carbon dioxide, ethylene, β-propiolactone 9 , and the corresponding aldehyde 2 . The dye-sensitized photooxidation in methanol of the azomethinimines 16 , prepared from 3-pyrazolidone and ketones, gives the following products: nitrogen, methyl β-methoxypropionate 3 , methyl acrylate 4 , and the corresponding ketone, besides hydrazine and the corresponding α-methoxy-alkylhydroperoxides 17 and 21 . Key intermediate of the peroxide formation is the Criegee ozonization zwitterion which was trapped with acetaldehyde as an ozonide.     

A Photographic Study of the Combustion Zones of burning double base propellant strands

The combustion zones of doublebase propellant strands and their dependence on pressure were studied by different photographic techniques to get new information on the action of ballistic modifiers. Photos of short exposure time were taken from the foam, dark and flame zones. The extinguished burning surface was studied by optical and scanning electron microscopes. A detailed picture on the production of carbonaceous material on the burning surface was obtained.     

Stability of acrylamide in model systems and its reactivity with selected nucleophiles

Since the discovery of relatively high amounts of the carcinogenic acrylamide in heat-processed food products, many studies have been devoted to the formation of acrylamide. However, as acrylamide is an α,β-unsaturated amide, subsequent reactions can provoke the desired removal of this compound. Therefore, the stability of acrylamide and its reactivity with various food-relevant nucleophiles were studied.The results showed that acrylamide was quite stable in aqueous solutions, but much less in dry reaction conditions. Buffer type and pH had a significant influence on the decrease of free acrylamide. The presence of amino acids with a nucleophilic side chain considerably decreased the free acrylamide, due to Michael-type addition reactions. The highest reactivity was noted for cysteine, leading to the formation of the mono-addition product cysteine-S-β-propionamide, as well as to the double addition product. Other nucleophiles, such as lysine, arginine, serine and ascorbic acid, were less reactive, but yielded comparable condensation products.     

Subacute myocardial infarction: assessment by STIR T2-weighted MR imaging in comparison to regional function

Purpose Increased T2 signal intensity (SI) can be regularly observed in myocardial infarction. However, there are controversial reports about the relationship of elevated T2 SI to myocardial viability and some authors propose that high T2 SI serves as a sign of irreversible myocardial injury. This study investigates increased T2 SI compared to myocardial function in patients with reperfused subacute myocardial infarction. Preserved function was used as criterion for viability. Methods Ten healthy volunteers and 17 patients with myocardial infarction and patent inlarct related coronary artery were examined on a 1.5 T Magnetom Vision system (Siemens). For T2-weighted MR imaging a breath-hold STIR sequence with dark-blood preparation was used. Cine FLASH 2D imaging was applied to assess myocardial function. Signal-to-noise (S/N) in STIR T2 images was measured in normal and infarcted regions and subsequently identified by two independent observers. Based on a 20 segment model of the left ventricle findings were compared to regional myocardial function. Results Elevated STIR T2 SI was found in all 17 patients and observed in 27% (204/754) of segments. S/N of normal myocardium was 5.1 ±0.7 in volunteers and 4.9 ± 0.8 in patients(P=NS). Infarcted myocardium presented with significantly-increased S/N 12.8 ± 1.9 (P < 0.0001). Significant transmural elevation of T2 SI was noted in 32% of segments with preserved systolic function. Conclusion Increased STIR T2 SI can be observed transmurally in post-ischemic myocardial regions with preserved function. It therefore cannot be used as an exclusive marker for the non-viable region.     

Experimental investigation and theoretical modelling of absolute convective drying of starch

Starch is a granular, hygroscopic, capillary-porous material with an intricate structure. It is known that drying starch till 0% moisture is a physical treatment that modifies starch properties. However, depending upon the heat and mass transfer mechanisms prevalent in the drying system, starch properties are modified in a unique manner. Therefore, the drying operation itself needs to be thoroughly understood. Potato starch was treated in an oven at three high-temperature levels (110, 130 and 140 °C) and for three sample thicknesses (2.8, 5.6 and 11.2 mm). It was observed that drying of starch with moisture content in the hygroscopic range occurred only in the 2nd falling rate period. Two existing theoretical, drying models, one based upon the Krischer Theory and the other based upon the Percolation Approach, were considered apt for modelling the oven drying. Both models describe the experimentally measured moisture profiles well. During drying, transition from one water sub-population to another was smooth. The effective diffusion coefficient decreased with moisture content and increased with temperature, but did not follow Arrhenius’ Law above 130 °C.