Quantitative analysis of 3-alkyl-2-methoxypyrazines in German Sauvignon blanc wines by MDGC–MS or MDGC–MS/MS for viticultural and enological studies

A method for trace-level analysis of 3-alkyl-2-methoxypyrazines (MPs) based on mixed-bed cation-exchange solid phase extraction followed by heart-cut multidimensional gas chromatographic analysis was applied in a trial on viticultural and enological treatments of Sauvignon blanc wines produced in Germany. The quantification was based on a stable isotope dilution assay using deuterated MPs. For method comparison, detection was either with selected ion monitoring with a quadrupole mass spectrometer (MS) or after selected reaction monitoring using a triple quadrupole MS. Comparable performance for MP detection in the lower ng L^?1 concentration range was found for both detection methods; however, in some cases, matrix problems could only be solved with MS/MS detection. It could be shown that MP levels varied considerably between the investigated vintages, with concentrations often well below 10 ng L^?1. Leaf removal as a viticultural trial was a measure to decrease MP concentrations; however, the effects observed were low in the vintages studied here. Cold maceration and stem addition to the must were found as valuable enological means for increasing the MP concentration and improving the green sensory notes typical for cold climate Sauvignon blanc wines.     

Lipophilic compounds and thermal behaviour of African mango (Irvingia gabonensis (Aubry-Lecomte ex. O'Rorke) Baill.) kernel fat

Irvingia gabonensis kernels are a promising oleiferous source. Their total lipid content was 72.3%. C14:0 and C12:0 represented the most abundant fatty acids. Triacylglycerols with ECN 32 and 46–48 were identified for the first time by HPLC-DAD-ESI-MSⁿ. Comprehensive GC-FID and GC-MS analyses revealed novel insights into minor lipids like phytosterols and tocochromanols. Among the latter, γ-tocopherol was found to be the major vitamer. β-Sitosterol and stigmasterol were the prevailing phytosterols in the kernel fat. The high saturation level of the fat resulted in a sharp differential scanning calorimetry melting curve with a high melting temperature of 42.1 °C. The fat remained solid over a wide temperature range and still contained 66.6% solid fats at 35 °C. Consequently, kernels of the African mango provide a viable source for the recovery of solid fats applicable in the food industry as sustainable alternatives to replace palm-based fats or hardened vegetable oils.     

晶粒取向电工钢带生产的完美解决

前言随着市场对高质量的晶粒取向电工钢带需求的不断增长,其价格也不断提升.这种材料的生产工艺路线是极其复杂的,并要求有若干条连续的,高技术含量的生产线来组成.根据各自的程序,其基本步骤包括热轧带钢的退火和除磷,紧接着有冷轧与脱碳同时进行的初次再结晶,以及为得到显微组织最终取向的二次再结晶及材料的精整.精整工艺通常包括最终...     

UML Statechart Diagrams on the ADONIS Metamodeling Platform

The metamodeling platform ADONIS has originally been implemented for the use in business process management. Its method independency and extensive customization functionalities also allow for the application in many different other areas such as strategic management, e-learning, object-oriented systems engineering, knowledge management, and numerous others. In computer science the Unified Modeling Language (UML) is the dominating standard for describing systems and behaviours. In this article it is shown how the abstract and concrete syntax of UML statechart diagrams can be described by the use of the metamodeling concepts of ADONIS.     

Predictive quality control of hybrid metal-CFRP components using information fusion

The paper presents an approach to determine the durability of hybrid metal-CFRP components combining the results of non-destructive testing (ndt) and finite element simulation The advantage of hybrid metal-CFRP components lies in the use of the properties of the materials used. CFRP parts with higher specific stiffness and strength are combined with metallic joining points, so that established joining processes for metal components can be applied to these lightweight components. In order to further promote the use of these hybrids in industry, it is necessary to guarantee a high level of component reliability through 100% quality control in order to avoid production-related defects. These defects such as delamination or fibre disorientation however vary in shape, size and position and lead to different effects on the part performance and reliability. Therefore the presented approach includes the application of non-destructive testing methods that are applied as in-line quality control measures in order to determine defect characteristics of the inspected parts. Due to the novelty of the component under test it is necessary to evaluate the individual criticality of detected defects and how they affect part performance during the testing procedure. Therefore the acquired ndt-data is used in finite element simulations where defect characteristics are added to the component model and whose effects on part reliability are evaluated. The generation of additional information combining non-destructive testing and simulation is referred to as data fusion. In order to evaluate the validity of the presented approach the determined part performances are compared to experimental mechanic tests.     

Witterungsbeständige Kunststoffe und Textilien im Automobilbau – Korrelation zwischen Frei-und Gerätrebewitterung – Teil I

Weather-Resistant Plastics and Fabrics in Automotive Engineering – Correlation between Natural and Artificial Weathering

1 Schriftfassung eines Vortrages, gehalten am 21. März 1996 in Mannheim, VDI-K-Jahrestagung „Kunststoffe im Automobilbau”︁

– Part I Plastics and textiles used in automotive engineering are partly exposed to extreme weathering influences. These produce an ageing of the materials and components, which can become visible e. g. in the form of cracks, color changes or deformations. The first part of this report deals with climatic variables that are important for the ageing of polymer materials and the stresses on vehicle components due to climate. In the second part test methods used to prove the weathering resistance will be presented, first the natural weathering, then some short-time testing methods of artificial weathering. Further the correlation between natural and artificial weathering will be explained using selected examples.