Inductive Effects on Molecular Ionization Potentials. V. Hydrogen Sulfide and Aliphatic Thioethers

The ionization energies of thioethers, R₂S, have been correlated with the polar substituent constants and the inductive substituent constants. Good correlations are obtained which indicate that the effect of alkyl substituents on the S-atom is primarily an inductive one.     

Multiple necking of tungsten fibers in a brass-tungsten composite

A model composite system, brass-tungsten, was used to study the effect of multiple necking of metal fibers, strain rate, and fiber surface condition on the ductility and deformation behavior of uniaxial metal matrix composites. Low volume percent (<20 vol pct) composites were made using brass (90 Cu-10 Zn) powders and tungsten wires. Tungsten wires contained in plastically deformed composites exhibited numerous necks per length of wire, with an average spacing between necks of 3 to 5 wire diameters. Composite ductility was shown to increase with decreasing multiple neck spacing and increasing percent reduction-in-area at the necks and was generally independent of strain rate. The multiple necking of tungsten wires in a brass matrix was found to result from local strain hardening of the brass matrix in the vicinity of each neck enabling the matrix to control composite deformation locally. Degrading the brass-tungsten interfacial bond by electropolishing the tungsten wires and coating them with graphite had no effect on the multiple necking phenomenon and composite ductility.     

Optimum Frame Synchronization for Biorthogonally Coded Data

The optimum procedure for locating a sync word periodically inserted in uncoded binary data received over a binary symmetric channel is based on the Hamming or bit distance metric. This concise paper addresses the corresponding frame-sync problem for biorthogonally coded data transmitted over the additive white Gaussian noise (AWGN) channel. For conceptual convenience, thek-bit words from the decoder output are treated as "super symbols" from an alphabet of dimension 2^k. It is argued that the optimum sync-word search over the decoded data stream is based on a supersymbol distance rule matched to the properties of the biorthogonally coded transmissions over the noisy channel. An optimum frame-sync acquisition algorithm based on this distance rule is formulated, and its performance is investigated. As an example, the performance of this optimum frame-sync algorithm is contrasted analytically with that of a Hamming distance algorithm operating on decoded (32, 6) biorthogonal data, a case of interest to some recent unmanned American space missions.     

Remediation of alpha-methylnaphthalene-contaminated sediments using peroxy acid

Laboratory experiments have been conducted to elucidate the degradation of alpha-methylnaphthalene in lake sediments using an advanced oxidation process (AOP) employing peroxy-acids as oxidizing agents. Abiotic degradation of alpha-methylnaphthalene was observed in sediment samples exposed to a 1:1:1 v/v/v mixture of water/organic acid/hydrogen peroxide solution. Sediment samples were collected from Lake Macatawa (Holland, MI) and ranged in total organic carbon content from 2.1% (sandy sediment sample III) to 12.8% (silty-clay sediment sample I) and surface area, which ranged from 3.2m(2)/g (sandy sediment sample III) to 22.0m(2)/g (silty-clay sediment sample I). Analytical measurements performed by gas chromatography revealed varied rates of degradation, depending on the type of acid and the characteristics of the sediment sample. Within 24h, alpha-methylnaphthalene was reduced to 70% and 100% of its original concentration when propionic acid and acetic acid were used as the organic acids, respectively. The formation of products was explored using a gas chromatograph equipped with a mass spectrometer and indicated mainly the formation of lower molecular weight compounds, such as alkyl chains. This AOP method of PAH degradation in sediment/liquid slurry was fast acting and products were most likely biodegradable.     

Three-dimensional confocal microscopy of colloids

Confocal microscopy is used in the study of colloidal gels, glasses, and binary fluids. We measure the three-dimensional positions of colloidal particles with a precision of approximately 50 nm (a small fraction of each particle's radius) and with a time resolution sufficient for tracking the thermal motions of several thousand particles at once. This information allows us to characterize the structure and the dynamics of these materials in qualitatively new ways, for example, by quantifying the topology of chains and clusters of particles as well as by measuring the spatial correlations between particles with high mobilities. We describe our experimental technique and describe measurements that complement the results of light scattering.     

A qualitative investigation of eminent therapists' values within psychotherapy: Developing integrative principles for moment-to-moment psychotherapy practice.

Ample empirical research on values has demonstrated that clients' values tend to become increasingly like those of their therapist during therapy. There is little research, however, on how therapists negotiate value conflicts and the role of values in therapy. In order to better understand this process, 14 expert psychotherapists from four major psychotherapy orientations were interviewed about their use of values in the psychotherapeutic change process. A grounded theory analysis was conducted leading to an integrative understanding of how expert therapists from different orientations conceptualize the relationship of values and change in therapy and how they work with values in sessions. Based on this analysis, four transtheoretical principles were generated that can be applied to training and practice and used to inform research on psychotherapy process and integration. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Expression of listeriolysin O and ActA by intracellular and extracellular Listeria monocytogenes

A gene encoding a chitin synthase with a myosin motor-like domain (csm1) was isolated from Pyricularia oryzae using a PCR fragment amplified from a fungal chitin synthase conserved region. The deduced amino acid sequence of csm1 is homologous to that of CsmA of Aspergillus nidulans (65% identity). The putative gene product of csm1 is consisted of the myosin motor-like domain and a chitin synthase domain as in A. nidulans csmA. The chitin synthase domain of its C-terminus was also homologous to Aspergillus fumigatus ChsE (61.4% identity) and Ustilago maydis Chs6 (48.6% identity) that encode class V chitin synthases. Northern analysis demonstrated that the csm1 was expressed throughout the mycelial growth of P. oryzae. This is the first report on the isolation of the gene encoding a class V chitin synthase with the myosin motor-like domain from P. oryzae.     

White Electroluminescence by Supramolecular Control of Energy Transfer in Blends of Organic‐Soluble Encapsulated Polyfluorenes

Here, it is demonstrated that energy transfer in a blend of semiconducting polymers can be strongly reduced by non‐covalent encapsulation of one constituent, ensured by threading of the conjugated strands into functionalized cyclodextrins. Such macrocycles control the minimum intermolecular distance of chromophores with similar alignment, at the nanoscale, and therefore the relevant energy transfer rates, thus enabling fabrication of white‐light‐emitting diodes (CIE coordinates: x = 0.282, y = 0.336). In particular, white electroluminescence in a binary blend of a blue‐emitting, organic‐soluble rotaxane based on a polyfluorene derivative and the green‐emitting poly(9,9‐dioctylfluorene‐alt‐benzothiadiazole ( F8BT ) is achieved. Morphological and structural analyses by atomic force microscopy, fluorescence mapping, µ‐Raman, and fluorescence lifetime microscopy are used to complement optical and electroluminescence characterization, and to enable a deeper insight into the properties of the novel blend.     

Harmonizing agriculture and health sector actions to improve household nutrition: policy experiences from Afghanistan (2002–2007)

Coordination across sectors to address undernutrition with its varied underlying causes remains a challenge in developing countries. In Afghanistan, harmonization of health and agriculture policies and actions to reduce endemic undernutrition occurred during 2002-2007. This qualitative case study explores the forms of harmonization, enabling features and constraints in the policy process. We interviewed 57 stakeholders (39 central level, 18 provincial) involved in public nutrition or food security issues. Forms of harmonization included written policies, reseach, training and advocacy. Important features of the policy process included: policy entrepreneurs with operational and strategic capacity, consensus-building using a shared causal framework, working groups and strategic alliances. This case presents an interesting alternative to a national nutrition coordinating body, an approach that has met with mixed results, often due to the lack of authority, budget, and operational capacity of such a body to oversee ministries and enforce national nutrition objectives. Mid-level professionals mobilized into task forces achieved much with the support of national and international partners. This study highlights the importance of building capacity for sustaining change through local institutions.