Polarographische Bestimmung von Schwefelverbindungen nebeneinander in wäßriger Lösung

Polarographische Bestimmung von Sulfat, Sulfit, Thiosulfat, Trithionat, Sulfid und Polysulfid im Gemisch. Überprüfung der Arbeitsvorschriften und Bestimmung der Genauigkeit und Bestimmungsgrenzen mit Modellanalysen. Untersuchung der Auslaugewässer von Hochofenschlacken.     

Isolation, identification and monitoring of contaminant bacteria in Iranian Kefir type drink by 16S rDNA sequencing

Iranian Kefir type drink (IKTD) is a highly consumed, traditional Iranian, fermented milk product. To improve monitoring procedures for food safety 32 industrial Kefir type drinks from 4 brands and 8 different production dates as well as 32 samples from pasteurized milk of the same Kefir manufacturers and air of the production sites were analyzed for contaminations. 16S rDNA extraction from Kefir samples as well as 16S rDNA obtained from samples incubated on Columbia agar were analyzed using PCR/DGGE, cloning, sequencing and phylogenetic classification. Already DGGE analysis indicated contaminations including Bacillus strains. Subsequently analysis of cultured clones indicated contaminations with Bacillus sp. including Bacillus cereus, Bacillus thuringiensis and Paenibacillus sp. in 9 (28%) from all analyzed samples. Also 38% of pasteurized milk samples were contaminated with B. cereus. The average count of B. cereus was 74 ± 19 cfu/ml. B. cereus and B. thuringiensis were found as contaminant bacteria in the air of the all manufacturing sites. These results suggest that milk is one of the most important sources of contamination with Bacillus sp., especially B. cereus for Kefir products in Iran. But bacterial contamination in Kefir samples might also originate from the air of the production sites. 16S rDNA analysis accelerates monitoring strategies.     

R&D for a single-layer Nb/sub 3/Sn common coil dipole using the react-and-wind fabrication technique

A dipole magnet based on the common coil design, using prereacted Nb/sub 3/Sn superconductor, is under development at Fermilab, for a future Very Large Hadron Collider. This magnet has some innovative design and technological features such as single layer coils, a 22 mm wide 60-strand Rutherford type cable and stainless steel collars reinforced by horizontal bridges inserted between coil blocks. Both left and right coils are wound simultaneously into the collar structure and then impregnated with epoxy. In order to optimize the design and fabrication techniques an R&D program is underway. The production of cables with the required characteristics was shown possible. Collar laminations were produced, assembled and tested in order to check the effectiveness of the bridges and the validity of the mechanical design. A mechanical model consisting in a 165 mm long section of the magnet straight section was assembled and tested. This paper summarizes the status of the program, and reports the results of fabrication and test of cable, collars and the mechanical model.     

Correction for protein content in the determination of the glucosinolate content of rapeseed by the X-RF method

Thirty six rapeseed samples from a factorial designed nitrogen and sulphur trial were analysed for total glucosinolate content by the X-ray fluorescence (X-RF) and HPLC methods and for protein content by the Kjeldahl method. Protein content varied from 16.0 to 22.6%. Correction for seed protein content in the calculation of glucosinolate content by X-RF significantly improved the agreement between the two methods of glucosinolate analysis. The following equation was used in the correction: Y = 14.99 [S(mg g^?1)-protein %/7.5].     

Estimation of manufacturing defects in the creep range

Various concepts are available for the estimation of crack-like manufacturing defects of components operated in the creep regime. All these methods raise questions as to their practicable application respectively transferability to the component. Discussing these problems resulted in the demand for the development of a “Two-Criteria-Diagram” which can represent practicable load conditions and make statements on the failure modus.     

Exact 3-satisfiability is decidable in time <Emphasis Type="Italic">O</Emphasis>(2<Superscript>0.16254<Emphasis Type="Italic">n</Emphasis></Superscript>)

Let F=C ₁C _m be a Boolean formula in conjunctive normal form over a set V of n propositional variables, s.t. each clause C _i contains at most three literals l over V. Solving the problem exact 3-satisfiability (X3SAT) for F means to decide whether there is a truth assignment setting exactly one literal in each clause of F to true (1). As is well known X3SAT is NP-complete [6]. By exploiting a perfect matching reduction we prove that X3SAT is deterministically decidable in time O(2^0.18674n ). Thereby we improve a result in [2,3] stating X3SATO(2^0.2072n ) and a bound of O(2^0.200002n ) for the corresponding enumeration problem #X3SAT stated in a preprint [1]. After that by a more involved deterministic case analysis we are able to show that X3SATO(2^0.16254n ).