Screening of indoles in cheese

 Indole and skatole (3-methylindole) are formed from tryptophan by microbial activity. Depending on their concentration, they may either contribute to an unpleasant odour, as described for pig meat, or alternatively to a positive aroma profile, as during ripening of cheese. In a screening study, the two indoles in various types of cheese were determined, by both HPLC and GC. It was found that the two compounds mainly occur in mould cheese, such as Camembert and are even more pronounced in blue-veined cheese. The concentrations in unripened cheese were up to 700 ng/g fat for indole and 50 ng/g fat for skatole. The formation of the two indoles increases when proteolysis during ripening provides more tryptophan. Skatole formation appears to be specifically favoured by a low pH and anaerobic conditions. Received: 14 May 1997     

Stable meshfree methods in fluid mechanics based on Green’s functions

Recently, stable meshfree methods for computational fluid mechanics have attracted rising interest. So far such methods mostly resort to similar strategies as already used for stabilized finite element formulations. In this study, we introduce an information theoretical interpretation of Petrov–Galerkin methods and Green’s functions. As a consequence of such an interpretation, we establish a new class of methods, the so-called information flux methods. These schemes may not be considered as stabilized methods, but rather as methods which are stable by their very nature. Using the example of convection–diffusion problems, we demonstrate these methods’ excellent stability and accuracy, both in one and higher dimensions.     

Two-tier relaxed heaps

We introduce a data structure which provides efficient heap operations with respect to the number of element comparisons performed. Let n denote the size of the heap being manipulated. Our data structure guarantees the worst-case cost of O(1) for finding the minimum, inserting an element, extracting an (unspecified) element, and replacing an element with a smaller element; and the worst-case cost of O(lg n) with at most lg n + 3 lg lg n + O(1) element comparisons for deleting an element. We thereby improve the comparison complexity of heap operations known for run-relaxed heaps and other worst-case efficient heaps. Furthermore, our data structure supports melding of two heaps of size m and n at the worst-case cost of O(min {lg m, lg n}). A preliminary version of this paper [8] was presented at the 17th International Symposium on Algorithms and Computation held in Kolkata in December 2006. Partially supported by the Danish Natural Science Research Council under contracts 21-02-0501 (project Practical data structures and algorithms) and 272-05-0272 (project Generic programming—algorithms and tools).     

Grundwasserneubildung und ihre Ermittlung – eine Anmerkung zum Beitrag von Hölting: Modellrechnungen zur Grundwasserneubildung

Ohne Zusammenfassung Eingang des Beitrages: 23.04.97     

Schallanalyse Neuronale Repräsentation des Hörvorgangs als Basis

Zusammenfassung Anlehnend an die überlegenheit des Menschen bei der Differenzierung von Schallsignalen, verglichen mit dem aktuellen Stand der Technik, widmet sich dieser Artikel dem Aufzeigen der Mechanismen und Vorg?nge, die sich bei der Verarbeitung von mechanischem Schall in Nervenimpulse innerhalb des Ohrs vollziehen, als Basis für eine m?gliche technische Nachbildung, z.B. zur Erkennung von Tonh?hen in Musik.     

移动和便携式电视系统的新纪元

在科技日新月异的今天,电视广播系统由模拟向数字的变迁已成为现实。预计在未来两年中,35％的电视将会以数字形式接收。除了家庭用的传统电视接收机外,消费者也期待便携式和移动电视接收机。移动电视接收的典型应用是车载电视,而便携式接收的典型应用是     

A review of the development and application of microalloyed medium carbon steels

Microalloyed medium-carbon steels with ferrite-pearlite microstructure were developed in the FRG in early 1972, with the primary aim of saving the cost of heat treatment. A steel with roughly 0.47% C, 0.75% Mn, 0.060% S and 0.1 % V was first used for crankshafts in cars manufactured by one of the largest European automobile companies. The effect of microalloying elements such as vanadium and niobium (niobium instead of columbium is used in this paper) in these steels and their dependence on the cooling rate from drop-forging temperatures is reviewed. Although niobium is more effective than vanadium, it leads to problems while manufacturing these steels with ~0.47% C, due to the high solution temperature of the niobium precipitates, so that preference has been given to vanadium. Further development work carried out to improve the ductility of these steels is reported. Steel compositions, which could make these steels applicable for various automobile and other engineering components, are presented.     

Kommentar II

Ohne Zusammenfassung     

ta‐C beschichtete Werkzeuge für die Trockenumformung von Aluminiumblechen

ta‐C coated tools for dry forming of aluminum sheets The suitability of ta‐C coated tool surfaces for sheet forming of aluminum alloys was examined by strip‐draw testing. It was shown that ta‐C coatings, which are known as DLC coatings with superior wear resistance are also favourable concerning the anti‐adhesive behaviour. In attempts with AlMg5Mn‐ as well as Al99Mg1‐sheet materials several hundred sheets could be formed without noticeable aluminum adhering at the ta‐C coated tool surface. Neither the coefficients of friction nor the surface qualities of the aluminum sheets worsened during the observed period. Compared with tests of uncoated tools in combination with lubricants, the dry ta‐C coated tool behaves comparable with a good lubricant. In a real clinch test with aluminum sheets the positive results from strip‐draw experiments were confirmed. Using ta‐C coated clinching stamps and no lubricants a large number of clinching processes could be performed without noticeable adhering and increase of stripping forces.     

Polymeric thin films of controlled complex refractive index formedby the electrostatic self-assembled monolayer process

This letter reports a method, the electrostatic self-assembled monolayer process, for the synthesis of multilayer thin-film materials with controlled complex refractive index. By incorporating appropriate precursor molecules in each monolayer and organizing the physical order of the multiple monolayers through the material, it is possible to achieve designed complex refractive index properties. In this work, the real part of the refractive index of materials formed by this process was controlled from 1.424 to 1.615, and the imaginary part was controlled from 0.00001 to 0.035, both at a wavelength of 550 nm. To our knowledge, this is the first time that experimental measurements of self-assembled thin films are presented to demonstrate that this method is useful for the design and synthesis of thin films of controllable refractive index