Use of spectroscopy of gamma-radiation from the inelastic scattering of reactor fast neutrons for elemental analysis

Gamma-spectra of stainless-steel and soil samples have been measured to study the potentialities of using spectroscopy of γ-radiation from the inelastic scattering of reactor fast neutrons for element analysis of various materials. Contents of iron, chromium, nickel, manganese, silicon and titanium in stainless steel, and those of silicon, iron, aluminium, magnesium, calcium, sodium, titanium, carbon and oxygen in soil have been determined by comparing the spectra of the samples with those of specially prepared mixtures of elements. The distinguishing features, advantages, and limitations of this method are discussed.     

Group-wise sufficient dimension reduction with principal fitted components

Sufficient dimension reduction methodologies in regressions of Y on a p-variate X aim at obtaining a reduction \(R(X) \in {\mathbb R}^{d}, d \le p\), that retains all the regression information of Y in X. When the predictors fall naturally into a number of known groups or domains, it has been established that exploiting the grouping information often leads to more effective sufficient dimension reduction of the predictors. In this article, we consider group-wise sufficient dimension reduction based on principal fitted components, when the grouping information is unknown. Principal fitted components methodology is coupled with an agglomerative clustering procedure to identify a suitable grouping structure. Simulations and real data analysis demonstrate that the group-wise principal fitted components sufficient dimension reduction is superior to the standard principal fitted components and to general sufficient dimension reduction methods.     

Evaluation of antibacterial and antioxidant activities of Artemisia campestris (Astraceae) and Ziziphus lotus (Rhamnacea)

The present work quantitatively evaluates the antimicrobial and antioxidant potentials of two Libyan folk medicinal plants [Artemisia campestris (Astraceae) and Ziziphus lotus (Rhamnacea)] that commonly grow in the south of Libya. The crude methanolic leaves extracts of both plants are appreciably active against Gram-positive species, associated with week anti-Gram-negative activity. These two plant extracts also showed reasonably high contents of polyphenolics and alkaloids, with minimal inhibitory concentrations between 12.5–25 and 250–1000 μg/ml for Gram-positive and Gram-negative species, respectively. Results collectively suggest that A. campestris and Z. lotus are not only reliable natural sources of antimicrobials but also potential sources of phenolic antioxidants and hence could be nominated for future intensive studies.     

Benchmarking of maintenance performance: a case study in two manufacturers of furniture

When profit margins of a plant are decreasing, the need forreliable and efficient maintenance policy becomes more important.Measuring maintenance performance is important for companiesto recognize whether their planned goals are achieved or not.Also, such measurements can be utilized for benchmarking, whichis one of the tools for never-ending improvement. But, theseobjectives cannot be achieved without well-documented data ofthe relevant variables. Better data coverage and quality isnecessary for following maintenance performance developmentand it would, in many cases, clarify the ambiguity concerningthe main problem in the context, namely that neither the productionnor maintenance department can show what effect maintenancehas on profitability. A more effective maintenance policy indirectly implies improvementsin product quality and manufacturing process effectiveness.Elongation of the production time, i.e. reducing the downtimedue to failures, planned replacements and repair, in additionto the improvement in the total maintenance activities, arealso some of the results that can be expected when an efficientmaintenance policy is used. Measuring and monitoring maintenanceperformance measures is required partly for detecting, and eventuallytreating as soon as possible, undesirable changes and partlyto make benchmarking with the best in the branch, which savesappreciable economic losses for companies. In this paper, a model for how to identify the measurable variables,which are needed to develop measures for monitoring maintenanceperformance behaviour systematically, is developed. Five maintenanceperformance measures are proposed and applied. An additionalmodel for systematically analysing the trend of maintenanceperformance measures, for an overall assessment of the company'ssituation, is presented. Two case studies in manufacturers offurniture are conducted to verify these models.     

Energy aware proactive optimized link state routing in mobile ad-hoc networks

In this paper we develop a novel energy aware routing approach for mobile ad hoc network (MANET) problems. The approach is based on using Optimized Link State Routing Protocol. Our Energy Aware OLSR labeled as OLSR_EA measures and predicts per-interval energy consumptions using the well-known Auto-Regressive Integrated Moving Average time series method. We develop a composite energy cost, by considering transmission power consumption and residual energy of each node, and use this composite energy index as the routing metric. Our extensive ns2 simulation experiments show that OLSR_EA substantially prolongs the network lifetime and saves total energy used in MANET. In our experiments we considered different scenarios considering a variety of traffic loads, node mobilities, homogeneous power consumption, and heterogeneous power consumption. Simulation results also confirm that OLSR_EA improves the traffic balance between nodes, and packet delivery ratio in higher node speed. We further develop characteristics of OLSR_EA in power-wise heterogeneous MANET to achieve efficient energy preserving performance.     

Discovery of potential M2 channel inhibitors based on the amantadine scaffold via virtual screening and pharmacophore modeling

The M2 channel protein on the influenza A virus membrane has become the main target of the anti-flu drugs amantadine and rimantadine. The structure of the M2 channel proteins of the H3N2 (PDB code 2RLF) and 2009-H1N1 (Genbank accession number GQ385383) viruses may help researchers to solve the drug-resistant problem of these two adamantane-based drugs and develop more powerful new drugs against influenza A virus. In the present study, we searched for new M2 channel inhibitors through a combination of different computational methodologies, including virtual screening with docking and pharmacophore modeling. Virtual screening was performed to calculate the free energies of binding between receptor M2 channel proteins and 200 new designed ligands. After that, pharmacophore analysis was used to identify the important M2 protein-inhibitor interactions and common features of top binding compounds with M2 channel proteins. Finally, the two most potential compounds were determined as novel leads to inhibit M2 channel proteins in both H3N2 and 2009-H1N1 influenza A virus.     

A remarkable accidental degeneracy in the1H-n.m.r. Spectrum of a (cyanoethene)platinum (II) complex

Summary In the¹H-n.m.r. spectra of (acetylacetonato)chloro-(²-cyanoetheiie)platinum(II), the three protons of the ligand appear to be equivalent.¹³C-n.m.r., i.r. and further¹H-n.m.r. studies indicate that the metal-ligand bonding is of orthodox -olefin type (as formulated in the name of the compound above). The two 2-hydrogens are made equivalent by fluxion, but there is an accidental degeneracy with 1-hydrogen atom.     

Synthesis and characterization of some rhodium(III) cyclometallated complexes of 2-substituted benzylideneamino thiazoles

Summary Schiffs bases derived from 2-aminothiazole and substituted benzaldehydes were reacted with [RhCl(PPh₃)₃] or [Rh(-Cl)(COD)]₂ (COD = 1,5-cyclooctadiene) in the presence of four equivalents of PPh₃ to give Rh^III cyclometallated complexes of the type [RhHCl{(X-benzylidene) thiazole}(PPh₃)₂], in which the imine C-H added oxidatively to the metal. The complexes were characterized using i.r., u.v. and n.m.r. spectroscopy. The disposition of the hydride ligand was inferred as trans to a N-donor ligand.     

Tripropyltin(iv) complexes with some selected bioligands in 50% v/v dioxane/water mixture

The interaction of the tri-n-propyltin(IV) (TPT) with some selected bioligands having a variety of model functional groups were investigated using potentiometric technique at 25 degrees C and 0.1 M ionic strength in 50% v/v dioxane/water mixture. TPT is hydrolyzed to give [(C3H7)3SnOH], [(C3H7)3Sn(OH)2]-, and [((C3H7)3Sn)2OH]+. Amino acids and DNA constituents form 1:1 and 1:2 complexes. Peptides form 1:1 complexes and the corresponding deprotonated amide species. The protonated complexes are formed with amino acids, peptides and some DNA constituents. The hydrolysis constants and the stepwise formation constants of the complexes formed in solution were calculated using the nonlinear least-square program MINIQUAD-75. The participation of different ligand functional groups in binding to organotin is discussed. The speciation diagrams of the various complex species were evaluated as a function of pH.