An analysis of the different parameters influence on the microbearing load carrying capacity

An analytical solution for the two-dimensional non-isothermal compressible gas flow in a slider microbearing is presented in this paper. The solutions enable analysis of the relevant parameters influences on the load carrying capacity of the micro-bearing. Hence, the influences of the flow conditions expressed by Mach, Reynolds and Knudsen numbers, the ratio of the inlet to outlet heights, bearing number, as well as temperature field are investigated. (© 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Water-induced isomerism of salicylaldehyde and 2-acetylpyridine mono- and bis-(thiocarbohydrazones) improves the antioxidant activity: spectroscopic and DFT study

Structural Chemistry - Thiocarbohydrazones (TCHs) and structurally related molecules are versatile organic compounds which exert antioxidant, anticancer, and other beneficial health effects. The...     

Stability of mycophenolate mofetil in polypropylene 5% dextrose infusion bags and chemical compatibility associated with the use of the Equashield® closed‐system transfer device

Stability studies are necessary in healthcare settings as they facilitate fast, cost‐effective and efficient work related to batch manufacturing and availability of supplies. We studied the stability of 1–10 mg/mL mycophenolate mofetil (MMF) in polypropylene 5% dextrose infusion bags prepared from Cellcept^® and with a generic brand name (Micofenolato de Mofetilo Accord) at different storage temperatures. To ensure chemical compatibility during preparation, we also tested MMF sorption to the Equashield^® closed‐system drug transfer device used in this step. For this, a validated stability‐indicating high‐performance liquid chromatography method was developed for the quantification and identification of MMF in the infusion bags. The analytical selectivity of the assay was determined by subjecting an MMF sample to extreme values of pH, oxidative stress and heat conditions to force degradation. Protected from light, 1–10 mg/mL MMF in infusion polypropylene bags prepared from reconstituted Cellcept^® 500 mg or Accord 500 mg in 5% dextrose was stable for at least 35 days when stored at 2–8°C or between ?15 and ?25°C, and for 14 days when stored at 25°C. MMF loss owing to chemical sorption to the Equashield^® closed‐system drug transfer device set was negligible.     

Local search intensified: Very large-scale variable neighborhood search for the multi-resource generalized assignment problem

We introduce a heuristic for the Multi-Resource Generalized Assignment Problem (MRGAP) based on the concepts of Very Large-Scale Neighborhood Search and Variable Neighborhood Search. The heuristic is a simplified version of the Very Large-Scale Variable Neighborhood Search for the Generalized Assignment Problem. Our algorithm can be viewed as a k-exchange heuristic; but unlike traditional k-exchange algorithms, we choose larger values of k resulting in neighborhoods of very large size with high probability. Searching this large neighborhood (approximately) amounts to solving a sequence of smaller MRGAPs either by exact algorithms or by heuristics. Computational results on benchmark test problems are presented. We obtained improved solutions for many instances compared to some of the best known heuristics for the MRGAP within reasonable running time. The central idea of our heuristic can be used to develop efficient heuristics for other hard combinatorial optimization problems as well.     

Primitive symmetric designs with prime power number of points

In this paper we either prove the non‐existence or give explicit construction of primitive symmetric (v, k, λ) designs with v=p^m<2500, p prime and m>1. The method of design construction is based on an automorphism group action; non‐existence results additionally include the theory of difference sets, multiplier theorems in particular. The research involves programming and wide‐range computations. We make use of software package GAP and the library of primitive groups which it contains. © 2009 Wiley Periodicals, Inc. J Combin Designs 18: 141–154, 2010     

Reversible Formation of a Light‐Responsive Catalyst by Utilizing Intermolecular Cooperative Effects

A photoresponsive system where structure formation is coupled to catalytic activity is presented. The observed catalytic activity is reliant on intermolecular cooperative effects that are present when amphiphiles assemble into vesicular structures. Photoresponsive units within the amphiphilic pre‐catalysts allow for switching between assembled and disassembled states, thereby modulating the catalytic activity. The ability to reversibly form cooperative catalysts within a dynamic self‐assembled system represents a conceptually new tool for the design of complex artificial systems in water.     

Enhanced Adhesion Properties,Structure and Sintering Mechanism of Hydroxyapatite Coatings Obtained by Plasma Jet Deposition

Plasma Chemistry and Plasma Processing - Hydroxyapatite (HA) coatings were deposited on high purity titanium substrate by atmospheric plasma spraying (APS) with high electric energy input....     

On-line strategies for determining trace levels of nitroaromatic explosives and related compounds in water

We report the development and tests of several systems for the simultaneous determination of 18 energetic compounds and related congeners in untreated water samples. In these systems a Restricted Access Material trap or liquid-chromatography precolumn (with a C(18) or porous graphitic carbon, PGC, stationary phase) followed by a PGC analytical column are used for sample clean-up, enrichment and separation of the trace level analytes, which are then analyzed by mass spectrometry (MS). The relative merits of two MS ionization interfaces (atmospheric pressure chemical ionization, APCI, and atmospheric pressure photoionization, APPI) were also compared for the MS identification and quantification of these analytes. APCI was found to be superior in cases where both alternatives are applicable. A major drawback when applying APPI is that no signal is obtained for the cyclic nitramines and nitrate esters. Using APCI, a wide spectrum of unstable compounds can be determined in a single analysis, and the feasibility of using large volume samples (up to 100 mL) in combination with the sensitivity of the MS detection system provide method detection limits ranging from 2.5 pg/mL (for 2,4-dinitrotoluene and 2,6-diamino-6-nitrotoluene) to 563 pg/mL (for pentaerythritol tetranitrate, PETN), with repeatability ranging from 2 to 7%. Other chemometric parameters such as robustness, selectivity, repeatability, and intermediate precision were also evaluated in the validation of the extraction methods for use in water analysis. Tests with untreated groundwater and drinking water samples, spiked with 20 ng of the analytes, yielded results similar to those obtained with high purity water samples.