Evaluation,modification and comparison of two rapid assays for cyanogens in cassava

Two rapid semi-quantitative assays for total cyanogens in cassava were evaluated. These were the well-known rapid picrate paper test, and a recently proposed rapid paper test involving the reagent tetra base (TB, 4,4′- methylenebis-(N, N-dimethylaniline)). A precise colorimetric assay was used as a control in the evaluative work. After primary evaluation, both assay methods underwent some modification regarding the interpretation of sample scores. As a result, the reliability of the picrate assay was greatly improved. The TB assay was modified in the interests of safety. Evaluation of this assay over a range of temperatures between 20 and 35°C showed no significant temperature effects upon performance when the new scoring interpretation system was used. The level of endogenous linamarase activity in the sample was found to be an influential factor in rapid assay performance. In a series of comparative trials in three distinct ecosystems, the newly modified picrate assay produced correct results in 68% of cases. This compared with 66% of results correct in the TB assay. It was observed that the TB assay performed more reliably with low cyanogen samples, whilst the picrate assay was more reliable with intermediate cyanogen samples.     

Do tricyclic responders have different brain laterality?

A previous study showed that depressed patients who improved with tricyclic antidepressant medication had dichotic complex tones test results suggesting right-hemisphere dysfunction relative to nonresponders and controls (G. E. Bruder et al., 1990). A new sample of 68 depressed patients completed dichotic consonant-vowel (CV) and complex tones (CT) tests and then were treated with imipramine or placebo. A significant Ear?×?Test?×?Treatment?×?Response interaction was accounted for by significantly poorer left-ear accuracy for CVs among imipramine responders compared with nonresponders, placebo responders, and controls. CV left-ear accuracy was also significantly greater among placebo responders than placebo nonresponders; and controls. The results only partially replicate the prior study in that evidence of right-hemisphere dysfunction in tricyclic responders was seen for the CV test but not the CT test. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How small the contacts could be optimal for nanoscale organic transistors?

We report on a study seeking an optimized contact configuration for organic transistors that minimizes contact effects but maintains smallest contact size. We begin with the bulk access resistance in staggered transistors which results from the charge transport through the organic semiconductor film. Bulk access resistance is an intrinsic contributor to the contact resistance which has been little understood due to lack of a reliable study tool. In this work, we utilize the inner transported power inside the semiconductor film as a medium to investigate the contact resistance and the relevant contact effects. We examine the influences of the organic film thickness (t_SC), the channel length (L), the underlying charge transport and various organic semiconductor materials with variable carrier mobility. A roughly optimal contact length (L_C) of L_C0 ≈ 6t_SC is obtained. The results reveal that besides the device architecture the underlying charge transport should be also taken into account in designing organic transistors for practical application.     

Safety climate and the Theory of Planned Behavior: Towards the prediction of unsafe behavior

The present study is concerned with the human factors that contribute to violations in aviation maintenance. Much of our previous research in this area has been based on safety climate surveys and the analysis of relations among core dimensions of climate. In this study, we tap into mainstream psychological theory to help clarify the mechanisms underlying the links between climate and behavior. Specifically, we demonstrate the usefulness of Ajzen's (1991, 2001) Theory of Planned Behavior (TPB) to understanding violation behaviors in aircraft maintenance. A questionnaire was administered to 307 aircraft maintenance workers. Constructs measured by the survey included perceptions of management attitudes to safety, own attitudes to violations, intention to violate, group norms, workplace pressures, and violations. A model based on the TPB illustrated hypothetical connections among these variables. Path analyses using AMOS suggested some theoretically justifiable modifications to the model. Fit statistics of the revised model were excellent with intentions, group norms, and personal attitudes combining to explain 50% of the variance in self-reported violations. The model highlighted the importance of management attitudes and group norms as direct and indirect predictors of violation behavior. We conclude that the TPB is a useful tool for understanding the psychological background to the procedural violations so often associated with incidents and accidents.     

New optical material europium EDTA complex in polyvinyl pyrrolidone films with fluorescence enhanced by silver plasmons

In our search for efficient Luminescent Solar Concentrators (LSC) we have prepared polyvinyl pyrrolidone (PVP) films incorporated by ethylenediamine tetraacetic acid (EDTA) complex of europium and co-doped with silver nanoparticles (NPs). Steady state fluorescence was studied under weak and strong excitation. Dynamical study was performed by second harmonic of Nd laser. Under weak excitation the fluorescence of europium co-doped with silver plasmons increased by a factor of three and excited by continuous laser by a factor of 50. The lifetimes of films doped by the complex were 755 μs and co-doped with silver nanoparticles 946 μs. This is the first finding that the photon density accumulates the number of plasmons interacting with electronic states of europium increasing its transition probability resulting in the strong intensification of fluorescence. In dynamical measurements of lifetimes a single pulse does not provide enough energy to create such number of plasmons.     

Some Basic Concepts Regarding the Separation of Oily Water Mixtures

The various factors that determine the stability and separation rate of oil from oily water mixtures are reviewed. The effect of droplet size, viscosity and unique interfacial properties promoted by the presence of surface-active agents are considered. The appropriate means to handle the separation/removal of oil from waste water effluents, as influenced by these factors, will be discussed. Wherever possible, first principles are applied; conversely, other areas are indicated where the nature of the problem dictates the reliance on empirical results and test data. Specific problems, properties and equipment are used throughout the presentation to illustrate the various concepts.     

A supply-side interregional model of the U.S. manufacturing industry: 1960–78

This paper presents a multiregional simultaneous model of the U.S. manufacturing industry based on the supply-side paradigm, focusing on the behavior of the primary inputs, capital stock and labor force, across the nine Census Regions. The estimated structure shows that the regional investment sensitively responds to the marginal productivity of capital in the respective region relative to the national average, while the net interregional migration basically follows the relative regional wages. As an application, the model is used for evaluating the economic value of migration and analyzing the relationship between the overall national growth and interregional equalization of income.Presented at Ninth Pacific Conference, Molokai, 1985.     

Neutral endopeptidase activity in newborn and adult rabbit tracheas

Neutral endopeptidase (NEP, E.C. 3.4.24.11), a widely distributed ectoenzyme, cleaves and inactivates a variety of biologically active peptides, including the tachykinin, substance P (SP). This study was undertaken to determine whether the modulation of SP airway smooth muscle contraction by NEP is age-dependent. We studied the contractile response of isolated tracheal rings from newborn and 120 day old New Zealand white rabbits. We measured NEP activity and determined immunoreactive NEP content in tracheal membrane preparations. NEP activity was then localized histochemically in sections of rabbit tracheas. In the presence of the NEP inhibitor, SCH 32615, the contractile response of isolated tracheal rings to SP was increased both in the newborn and 120 day old rabbits. However, the increase was greatest in the newborn animals. NEP activity in tracheal membrane preparations increased fivefold between the newborn and 120 day old rabbits. Western blot analysis also revealed a significant increase in the immunoreactive NEP content of these tracheal membrane preparations between the newborn and 120 day old rabbits. NEP activity, localized histochemically, was most intense in the epithelial region of the newborn animals, with a shift of activity to the subepithelial region with age. The prominent epithelial localization of neutral endopeptidase in the tracheas of these 1 day old rabbits, which we have shown to have relatively low neutral endopeptidase activity, suggests that the location of neutral endopeptidase in the airway, including proximity to relevant substance P receptors, may be critical to its function.     

Miscibility and thermal and dynamic mechanical behaviour of semi‐interpenetrating polymer networks based on polyurethane and poly(hydroxyethyl methacrylate)

The thermodynamic miscibility and thermal and dynamic mechanical behaviour of semi‐interpenetrating polymer networks (semi‐IPNs) of crosslinked polyurethane (PU) and linear poly(hydroxyethyl methacrylate) (PHEMA) have been investigated. The free energies of mixing of the semi‐IPN components have been determined by the vapour sorption method and it was established that the parameters are positive and depend on the amount of PHEMA in the semi‐IPN samples. Thermal analyses glass transition temperatures evidenced two in the semi‐IPNs in accordance with the investigation of the thermodynamic miscibility of these systems. Dynamic mechanical analysis revealed a pronounced change in the viscoelastic properties of the PU‐based semi‐IPNs with different amounts of PHEMA in the samples. The semi‐IPNs have two distinct tan δ maxima related to the relaxations of the two polymers in their glass temperature domains. The temperature position of PU relaxation maximum tan δ is invariable but its amplitude decreases in the semi‐IPNs with increasing amount of PHEMA in the systems. The tan δ maximum of PHEMA is shifted to a lower temperature and its amplitude decreases with increasing amount of PU in the semi‐IPNs. The segregation degree of components α was calculated using the viscoelastic properties of semi‐IPNs. It was concluded that the studied semi‐IPNs are two‐phase systems with incomplete phase separation. The different levels of immiscibility lead to the different degree of phase separation in the semi‐IPNs with compositions. Copyright © 2004 Society of Chemical Industry     

HAWT near‐wake aerodynamics,Part I: axial flow conditions

An improved physical understanding of the rotor aerodynamics of a horizontal axis wind turbine (HAWT) is required to reduce the uncertainties associated with today's design codes. Wind tunnel experiments contribute to increased knowledge and enable validation and construction of models. The present study focuses on the near‐wake of a model HAWT in both axial and yawed flow conditions. At three downstream planes parallel to the rotor plane, single‐sensor hot‐film traverses are made. The phase‐locked unsteady three‐dimensional flow velocity vector is determined by a novel data reduction method. A series of two papers discusses the near‐wake aerodynamics of a model HAWT. The main goals are to obtain a detailed understanding of the near‐wake development and to arrive at a base for model construction and validation. The first paper presents the experimental setup, data reduction and the results for the baseline case (axial flow conditions). In the second paper, the results for the yawed flow cases are presented and the effect of yaw misalignment on the near‐wake development is discussed. Copyright © 2008 John Wiley & Sons, Ltd.