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31.
Marion Balz E. Schulte H.-P. Thier 《European Journal of Lipid Science and Technology》1992,94(6):209-213
HPLC Separation of Tocopherols and Tocotrienols The four tocopherols (T) and four tocotrienols (T3) as well as plastochromanol-8 (P-8) and BHA were separated completely by eluting them from a HPLC diol-column with n-hexane/methyl tert-butylether (96 : 4, v/v). Even for the β- and γ-tocopherol and -tocotrienol isomers, baseline separation was achieved. The method was verified. The method was verified with success on several plant seed oils which were injected directly without any clean-up. For cereals a simplified extraction method was developed and the T, T3 and P-8 content of 9 cereal crops was determined. The separation system showed a long-term stability over six month. 相似文献
32.
Erhard Schulte 《European Journal of Lipid Science and Technology》2004,106(11):772-776
The polar components, formed in fats during deep‐frying, comprise a multitude of different artifacts. Their content is a suited indicator of fat quality. As an alternative to the time‐ and chemicals‐consuming official methods a simplified micromethod is described. The method employs general laboratory equipment and disposable consumables. The eluent mixture of petroleum ether + diethyl ether (90 + 10) was substituted by a mixture of isohexane + diisopropyl ether (85 + 15), because the high volatility of the former eluent caused problems at elevated ambient temperatures, e.g. during hot summers. 相似文献
33.
Schulte Dorothea; Hengstenberg Wolfgang 《Protein engineering, design & selection : PEDS》2000,13(7):515-518
Several amino acids in the active center of the 6-phospho-ß-galactosidasefrom Lactococcus lactis were replaced by the corresponding residuesin homologous enzymes of glycosidase family 1 with differentspecificities. Three mutants, W429A, K435V/Y437F and S428D/K435V/Y437F, were constructed. W429A was found to have an improvedspecificity for glucosides compared with the wild-type, consistentwith the theory that the amino acid at this position is relevantfor the distinction between galactosides and glucosides. Thekcat/Km for o-nitrophenyl-ß-D-glucose-6-phosphate is 8-foldhigher than for o-nitrophenyl-ß-D-galactose-6-phosphatewhich is the preferred substrate of the wild-type enzyme. Thissuggests that new hydrogen bonds are formed in the mutant betweenthe active site residues, presumably Gln19 or Trp421 and theC-4 hydroxyl group. The two other mutants with the exchangesin the phosphate-binding loop were tested for their abilityto bind phosphorylated substrates. The triple mutant is inactive.The double mutant has a dramatically decreased ability to bindo-nitrophenyl-ß-D-galactose-6-phosphate whereas the interactionwith o-nitrophenyl-ß-D-galactose is barely altered. Thisresult shows that the 6-phospho-ß-galactosidase and therelated cyanogenic ß-glucosidase from Trifolium repenshave different recognition mechanisms for substrates althoughthe structures of the active sites are highly conserved. 相似文献
34.
Philipp Landkammer Thomas Schneider Robert Schulte Paul Steinmann Marion Merklein 《Production Engineering》2016,10(1):93-102
Inverse form finding aims in determining the optimal material configuration of a workpiece for a specific forming process. A gradient- and parameter-free (nodal-based) form finding approach has recently been developed, which can be coupled non-invasively as a black box to arbitrary finite element software. Additionally the algorithm is independent from the constitutive behavior. Consequently, the user has not to struggle with the underlying optimization theory behind. Benchmark tests showed already that the approach works robustly and efficiently. This contribution demonstrates that the optimization algorithm is also applicable to more sophisticated forming processes including orthotropic large strain plasticity, combined hardening and frictional contact. A cup deep drawing process with solid-shell elements and a combined deep drawing and upsetting process to form a functional component with external teeth are investigated. 相似文献
35.
Stefanie Viktoria Caroline Schulte 《国际水》2019,44(4):427-443
California introduced its first comprehensive groundwater legislation (the Sustainable Groundwater Management Act) in 2014 to address the overuse of the state’s groundwater resources and to establish a pathway for sustainable groundwater use. However, a recent decision by the US Court of Appeals for the Ninth Circuit declaring the existence of federal reserved rights to groundwater could complicate the future implementation of California’s new groundwater legislation. This article explores the impact of the case and offers recommendations on how the tensions between the court’s decision and the existing legal framework for groundwater management in California could be reduced. 相似文献
36.
Marion Balz Erhard Schulte Hans -Peter Thier 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1996,202(1):80-81
The quality of an -tocopherol standard can be checked easily by measuring the UV absorbance at minimum (255 nm,A
min) and maximum (292 nm,A
max) wavelengths inn-hexane. If the quotientA
min/A
max exceeds 0.18, the standard contains less than 90% -tocopherol and the determination at 292 nm will yield inaccurate results. 相似文献
37.
V. A. Pugsley G. Korn S. Luyckx H. -G. Sockel W. Heinrich M. Wolf H. Feld R. Schulte 《International Journal of Refractory Metals and Hard Materials》2001,19(4-6):311-318
The influence of a corrosive wood-cutting environment on the strength of hardmetals and on their behaviour under static loading conditions has been investigated. Two commercial hardmetals were tested, which differed in hard phase composition. The results show exposure to this environment to have a highly detrimental influence on the strength of both hardmetals investigated, due to localised corrosive attack which results in the formation of stress raisers. The relative loss in strength as a function of corrosion time is the same for both hardmetals. However, the performance of the two grades differ significantly when a static load is applied in this corrosive environment: the strength of the WC-Co grade remains unaffected by the applied load, while the grade containing a mixed carbide phase exhibits stress corrosion cracking which results in a further reduction in strength. 相似文献
38.
A. Schulte 《Cognition, Technology & Work》2002,4(3):146-159
This paper describes an approach to cognitive and cooperative operator assistance in the field of tactical flight mission
management. A framework for a generic functional concept is derived from general considerations of human performance and cognitive
engineering. A system built according to these human-centred design principles will be able to keep up with the change of
situation parameters, in order to provide situational adapted operator assistance. Such a cognitive assistant system represents an approach to ensure the highest degree possible of situation awareness of the flight deck crew as well as a
satisfactory workload level. This generic approach to mission management and crew assistance for military aircraft has been
realised in different application domains such as military transport and air-to-ground attack. The Crew Assistant Military Aircraft is a functional prototype for the air transport application. Even applications in the domain of uninhabited aerial vehicles
(UAV) are in reach. This paper mainly covers one state-of-the-art research and development activity in the domain of combat
aircraft: the TMM – Tactical Mission Management System is an experimental solution for the air-to-ground attack role. The TMM has been implemented as a functional prototype in
the mission avionics experimental cockpit (MAXC), a development flight simulator at ESG and evaluated with German Air Force
pilots as subjects in simulator trials. Therefore, the TMM has been compared with a reference cockpit avionics configuration
in terms of task performance, workload, situation awareness and operator acceptance. After giving an overview of the system
concepts this paper reports on the experimental design and results of the simulator trial campaign. 相似文献
39.
40.
O Weijtens RC Schoemaker AF Cohen FP Romijn EG Lentjes J van Rooij JC van Meurs 《Canadian Metallurgical Quarterly》1998,125(5):673-679
OBJECTIVE: To assess the outcomes of changes in mental health policy introduced in Italy in 1978. METHODS: Data on psychiatric services, before and after the policy change, are presented. Effects of change are evaluated through indicators related to four issues: transfer of care, criminalisation of the mentally ill, suicides, and homelessness. RESULTS: Admissions of new patients to mental hospitals have been stopped and the size of the mental hospital population is now very low (26 per 100,000 population). Psychiatric care has been shifted to community services including general hospital psychiatric units. There has been an overall reduction of psychiatric hospitalisation. However, the provision of residential facilities is inadequate and community services are unevenly distributed across the country. Few negative effects of changing patterns of care have been reported, although the low quality of data limits the validity of such a conclusion. Outcome of care in areas where the full range of community services is available has been rated as satisfactory. CONCLUSIONS: Although care of the mentally ill has been shifted to community services, we lack hard data on the social and clinical outcome of community care at the nation-wide level. Long-term monitoring and evaluation of community services is a high priority in Italy. 相似文献