Balancing-compensation system for the vertically moving elements of the machine tools with numerical control

The main topic consists of enhancing the geometrical and positioning accuracy of the machine tools with numerical control. Currently, in order to minimize the errors met during the vertical motions of the moving elements in the structure of a machine tool, various systems are used that are relatively complex and whose adjustments are difficult to do. This work is presenting a balancing–compensation system of the elements moving vertically that includes three invention patents; it has a simple structure that is easily adaptable to various types of machine tools. The newness element of the balancing-compensation system is represented by the pressure regulator being used, whose operation principle and design is described into detail. The related results have been reified in increasing by approximately 10 times the geometrical accuracy and, by default, the positioning accuracy of the element moving in a vertical plane.     

Electrical DC conduction mechanism in some newly synthesized nylon 6/12 copolymers

The synthesis and the study of DC electrical transport properties (electrical conductivity, σ, and Seebeck coefficient, S) as a function of temperature of some recently synthesized nylon 6/12 copolymers with 0, 5, 10, 20, 30, and 50 wt % laurolactam (LL), respectively, are reported. Nylons were obtained by rotational molding via the anionic activated copolymerization of ε‐caprolactam and LL. As evidenced by XRD analyses, they are semicrystalline. The temperature dependences of σ and S are typical for polycrystalline semiconducting (p‐type) materials. The activation energy of electrical conduction lay in the range 0.79–1.22 eV, while the ratio of charge carrier mobilities ranged between 0.53 and 0.77. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 794–799, 2007     

Separation of nitrophenols. Equilibriums in bi- and tri-phasic systems

The paper presents experimental data obtained in the study of liquid–liquid partition equilibriums in biphasic system in order to optimize the process of transport through bulk liquid membranes (triphasic partition systems). The partition equilibriums of some nitrophenols using chloroform as extraction solvent and membranary solvent, respectively, were studied. The influence of the pH on the partition equilibriums was investigated. The repartition constants and the pK_a values of the studied nitrophenols were calculated. Nitrophenols were transferred in triphasic system from a feed phase with pH 2, through a chloroform liquid membrane, into a receiving phase with pH 12, with efficiencies over 90%.     

GC-MS Analysis of Methadone and EDDP in Addicted Patients under Methadone Substitution Treatment: Comparison of Urine and Plasma as Biological Samples

(1) Background: Methadone, along with buprenorphine, is the most commonly used drug for the treatment of opioid dependence. This study aimed to analyze methadone and its major metabolite, 2-ethylidene-1,5-dimethyl-3,3-diphenyl pyrrolidine (EDDP), in the urine and plasma of opiate addicts. The study group consisted of drug users voluntarily admitted to the detoxification center C.E.T.T.T. “St. Stelian” of Bucharest. Secondly, the study aimed to identify whether urine or plasma provides better results for the proposed method. (2) Methods: A GC-MS method, using an internal standard (diphenylamine) in the FULL-SCAN and SIM modes of operation and using the m/z = 72 ion for methadone and the m/z = 277 ion for EDDP, combined with a liquid–liquid extraction procedure was performed. (3) Results: The applied procedure allows the detection and quantification of methadone in both urine and plasma samples. EDDP was identified in patients with higher levels of methadone. Higher levels of methadone were detected in urine than in plasma samples. (4) Conclusions: This procedure can be used in clinical laboratories for the rapid determination of methadone levels in urine rather than in plasma. The procedure can be applied for the monitoring of methadone substitution treatment.     

Some abstract maximal ideal-like spaces

Presented by R. S. Pierce.     

Über die Finslerschen Räume mit konform verallgemeinerter Struktur

Ohne Zusammenfassung     

Sur les solutions fondamentales d'ordre fini de croissance

Sans résumé     

Ordinary p-Laplacian systems with nonlinear boundary conditions

This paper is concerned with the existence of solutions for the boundary value problem