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71.
Mohamed M. Soumanou Uwe T. Bornscheuer Rolf D. Schmid 《Journal of the American Oil Chemists' Society》1998,75(6):703-710
Structured triacylglycerides with medium-chain fatty acids (caprylic acid) in sn1- and sn3-positions and a long-chain unsaturated fatty acid (oleic or linoleic acid) in the sn2-position of glycerol (MLM) were synthesized by lipase catalysis in a two-step process. First, pure 2-monoacylglycerides
(2-MG) were synthesized by alcoholysis of triacylglycerides (triolein, trilinolein, or peanut oil) in organic solvents with
1,3-regiospecific lipases (from Rhizomucor miehei, Rhizopus delemar, and Rhizopus javanicus). The 2-MG were purified by crystallization and obtained in up to 71.8% yield. These 2-MG were esterified in a second reaction
with caprylic acid in n-hexane to form almost pure MLM. For 2-MG obtained from peanut oil, the final product contained more than 90% caprylic acid
in the sn1- and sn3-positions, whereas the sn2-position was composed of 98.5% unsaturated long-chain fatty acids. Reaction conditions for both steps were optimized with
respect to source and immobilization of lipase, water activity, and solvent. 相似文献
72.
Stephan Bose-O'Reilly Gustav Drasch Saulo Rodrigues-Filho Beate Lettmeier Alexandra Maydl Uwe Siebert 《The Science of the total environment》2010,408(4):713-1000
Small scale miners use mercury to extract gold from ore in many countries. An environmental and health assessment was performed in Indonesia in two regions, Galangan in Central Kalimantan and Talawaan in Northern Sulawesi. The environmental assessment showed severe mercury contamination of the sediments, and increased mercury levels in local fish. For the health investigation 281 volunteers were recruited and examined by a standardized questionnaire, a neurological examination and neuro-psychological tests. A medical score was used consisting of significant factors of mercury intoxication. Mercury exposed workers showed typical symptoms of mercury intoxication, such as movement disorders (ataxia, tremor, dysdiadochokinesia, etc.). Blood, urine and hair samples were taken from any participant and analyzed for mercury. The mercury concentration in the biomonitors was high, partly extreme high in the working population, increased in the population living in the same habitat and low in the control group. By a standard protocol which includes a combination of threshold values of mercury in the biomonitors and a medical sum score the diagnosis of chronic mercury intoxication was made for highly burdened workers (amalgam smelters) in 55% in Sulawesi and in 62% in Kalimantan. Less exposed mineral processors and the general population in the mining areas were also intoxicated to a high percentage. 相似文献
73.
Stefano Panebianco Klara Berg Jean-Christophe David Mohamed Eid Uwe Filges Friedrich Gröschel Arnaud Guertin Alexander Yu Konobeyev Christian Latgé Sébastien Lemaire Sylvie Leray Alain Letourneau Markus Lüthy Franco Michel-Sendis Selene Scazzi Gediminas Stankunas Nicolas Thiollière Leonhard Tobler Luca Zanini 《Annals of Nuclear Energy》2009
The MEGAPIE project aimed to design, build and operate a liquid metal spallation neutron target of about 1 MW beam power in the SINQ facility at the Paul Scherrer Institut (Villigen, Switzerland). This project is an important step in the roadmap towards the demonstration of the accelerator driven system (ADS) concept and high power liquid metal targets in general. Following the design phase, an experimental program was defined to provide a complete characterization of the facility by performing a “mapping” of the neutron flux at different points, from the center of the target to the beam lines. The neutronic performance of the target was studied using different experimental techniques with the goals of validating the Monte Carlo codes used in the design of the target; additionally, the performance was compared with the solid lead targets used before and after the MEGAPIE experiment. 相似文献
74.
在AiF研究项目的(AiF编号:14315)的范围内,通过在邓肯道夫纺织工艺研究所(ITV)对锭子的开发,即应用旋转纱线制动装置和经过优化的钢领钢丝圈系统,研究了改善加工化学纤维的环锭纺设备的性能的可能性. 相似文献
75.
76.
A facile chemical reduction method has been developed to fabricate ultrafine copper nanoparticles whose sizes can be controlled
down to ca. 1 nm by using poly(N-vinylpyrrolidone) (PVP) as the stabilizer and sodium borohyrdride as the reducing agent in an alkaline ethylene glycol (EG)
solvent. Transmission electron microscopy (TEM) results and UV–vis absorption spectra demonstrated that the as-prepared particles
were well monodispersed, mostly composed of pure metallic Cu nanocrystals and extremely stable over extended period of simply
sealed storage. 相似文献
77.
78.
In this paper, we address the problem of localizing extrema points and iso-contours of ambient environmental fields (specifically,
ocean bottom landscape and underwater plumes) using a networked formation of autonomous underwater vehicles. We propose the
use of the Nelder-Mead extension to the basic simplex nonlinear optimization algorithm. In these robust gradient-free strategies,
decisions are solely made based on field values measured by the individual vehicles, while measurements are fused and actions
decided according to the algorithm. A main goal of this paper is to trigger interest in direct search methods as pertains
to this type of robotic problem. 相似文献
79.
Capturing software design knowledge is important because it tends to evaporate as software systems evolve. This has severe consequences for many software projects. To counteract this phenomenon, effective, systematic documentation of design knowledge is important. However, many proposed approaches for capturing design knowledge are still experimental or in an early-adoption stage. In this article, we discuss existing and new approaches to deal with parts of the knowledge evaporation problem. 相似文献
80.
Akram El Hasni Stefan Pfirrmann Anett Kolander Erwin Yacoub-George Martin König Christof Landesberger Anja Voigt Gabi Grützner Uwe Schnakenberg 《Microfluidics and nanofluidics》2017,21(3):41
We present a new epoxy-based negative-tone dry film photoresist (DFR) for fabricating multilayer microfluidic devices using a lamination process combined with a standard photolithography technology. As proof-of-concept, a complex 3D-hydrodynamic focusing device was produced via a six-layer lamination process of 33 µm-thick DFR layers. The bonding strength of the new DFR was tested on silicon, glass, and titanium substrates, respectively. A maximum bonding strength of 37 MPa was obtained for the dry film photoresist laminated on glass. No leakage was found, and burst tests proved excellent robustness and sealing reliability of the microchannels. 相似文献