High-performance size-exclusion chromatographic determination of the potency of biosynthetic human growth hormone products

A new high-performance size-exclusion chromatography method has been developed for the determination of potency of human growth hormone products. This method has been extensively validated and shown to correlate well with the hypophysectomized rat bioassay which has been used traditionally. The method is much more precise than the traditional bioassay and thus provides more reliable means of producing consistent biosynthetic human growth hormone batches.     

Polarographic behavior of uranium(VI) in malonic acid media determination of uranium in plutonium

The polarographic behavior of the uranium-malonate complex was investigated over the pH range 1.1–6.5. A reversible, one-electron wave was obtained. Below pH 4.9, the rate of disproportionation is nearly instantaneous and gives rise to a pseudo uranium(VI)-uranium(IV) reduction. Above pH 4.8 the concentration of uranium(V) is stable with respect to disproportionation. The half-wave potential is pH-dependent below pH 4.9, but it is independent of the malonate concentration above O.1 M. The diffusion current constant is 2.78 for the conditions described. A procedure for the determination of uranium in plutonium was developed for uranium concentrations greater than 225 p.p.m. Of 21 common impurities found in plutonium metal, only Cu, Fe, Pb, Sb and Ti cause significant interference ; titanium can be removed by ion exchange, and the other interferences by mercury cathode electrolysis.     

Semi-wet growth and characterization of multi-functional nano-engineered mixed metal oxides for industrial application

This review paper covers the low temperature wet growth of nano-engineered particles of ZnO-based mixed metal oxides, their growth mechanism, and characterization using X-ray diffraction, SEM, TEM and IR, UV–visible, and XPS spectral techniques. Main focus of this article is centered on low temperature semi-wet methods of synthesis that are suitable for large scale production of zinc oxide-based systems mixed with iron oxide, copper oxide, nickel oxide and cobalt oxide. These mixed metal oxides have broad industrial applications as catalyst, semiconductors, adsorbents, superconductors, electro-ceramics, and antifungal agents in addition to extensive applications in medicines. This paper discusses the low-cost and environment friendly synthesis of these mixed metal oxides, measurement of properties and applicability of these materials systems.     

Principles to guide international standard tests for liquid chemical germicides: a proposal.

This review discusses issues involved in developing standard tests for liquid chemical germicides and suggests some guiding principles to be considered for future development of harmonized international standard methods for testing disinfectants and sterilants. A published test method to measure sporicidal activity is used as an example of the implementation of these principles.     

三轴模拟台的交叉耦合及其控制方法的研究

本文主要从三轴转台的模型出发，研究了采用状态反馈的最优控制及状态观测器来提高控制系统的自适应能力，以解决三轴台特有的不确定非线性耦合问题和变结构解耦控制。     

Logic of secrets in collaboration networks

The article proposes Logic of Secrets in Collaboration Networks, a formal logical system for reasoning about a set of secrets established over a fixed configuration of communication channels. The system’s key feature, a multi-channel relation called independence, is a generalization of a two-channel relation known in the literature as nondeducibility. The main result is the completeness of the proposed system with respect to a semantics of secrets.     

Norms extremal with respect to the Mahler measure

In this paper, we introduce and study several norms which are constructed in order to satisfy an extremal property with respect to the Mahler measure. These norms are a natural generalization of the metric Mahler measure introduced by Dubickas and Smyth. We show that bounding these norms on a certain subspace implies Lehmer?s conjecture and in at least one case that the converse is true as well. We evaluate these norms on a class of algebraic numbers that include Pisot and Salem numbers, and for surds. We prove that the infimum in the construction is achieved in a certain finite dimensional space for all algebraic numbers in one case, and for surds in general, a finiteness result analogous to that of Samuels and Jankauskas for the t-metric Mahler measures.     

Spherically symmetric inhomogeneous dust collapse in higher dimensional space-time and cosmic censorship hypothesis

We consider a collapsing spherically symmetric inhomogeneous dust cloud in higher dimensional space-time. We show that the central singularity of collapse can be a strong curvature or a weak curvature naked singularity depending on the initial density distribution.