Preserving poultry feeds in the humid tropics: A trial of calcium propionate under feed mill conditions

Calcium propionate was incorporated into a complete poultry feed and a feed concentrate at levels of 0, 0.3, 0.4 and 0.6%. The feeds were stored in 25 kg woven sacks in a feed mill. Air temperatures ranged from 22 to 34°C and relative humidity was in the range 67 to 93%. Mould growth was measured microbiologically and by measurement of feed temperature. Calcium propionate had a large effect on the microbiological measurements but only a small effect on heating in the feeds. As a preservative, it retained its activity for 6 weeks which extended the storage life by only 1 week in this case. The relative merits of the microbiological and temperature measurements are discussed.     

Morphology evolution during cooling of quiescent immiscible polymer blends: matrix crystallization effect on the dispersed phase coalescence

The influence of the matrix crystallization on the coalescence of the dispersed phase particles, in quiescent immiscible polymer blends, is a topic that is scientifically addressed scarcely. The coarsening of the phase structure that is induced by the matrix crystallizing domains was studied using the well-established system comprising a polypropylene and an ethylene–propylene rubber (PP/EPR blends). This subject is of great importance as the effectiveness in the toughening of PP is directly determined by the EPR particle size. Cooling experiments were commenced for resolving the correlation among the imposed cooling conditions, the formed matrix crystalline morphology, and the coalescence of the dispersed phase particles. A confirmation of the profound effect of the PP crystallization on the coalescence of EPR particles was undoubtedly obtained. The contribution of the crystallization to the coalescence of the dispersed phase particles is largest at a finite rate of cooling. A thorough discussion regarding the observed effects, encompassing a potential rejection or an engulfing of the dispersed phase particles by the growing crystallites, was undertaken.     

Surface modification of ion‐exchange membranes: Methods,characteristics, and performance

Considerable effort has been made to improve ion‐exchange membrane (IEM) properties in order to achieve better performance of IEM‐based processes in various applications. Surface modification is one of the effective ways to improve IEM properties. Various methods have been used to modify IEM surfaces, for example, plasma treatment, polymerization, solution casting, electrodeposition, and ion implantation. These methods are able to produce a thin and fine distributed layer and also to modify the chemical structure of the surface. The new layer can be adsorbed, deposited, or chemically bonded on a membrane surface. By using these methods, IEM properties are improved, and the desired or specific characteristics such as high monovalent ion permselectivity, low fuel crossover, and anti‐organic‐fouling property can be obtained. In this paper, methods for surface modification of IEMs are reviewed. Moreover, the effects of modification on IEM properties and performance are discussed. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45540.     

The development of a response surface model for the determination of infinite dilution partial molar volumes and excess volumes from dilute multi-component data alone. Implications for the characterization of non-isolatable solutes in complex homogeneous reactive systems

A non-ideal system containing several solutes, e.g. methanol, acetone, and 2-butanol in n-hexane was studied. Traditionally defined excess molar volumes (based on pure component molar volumes) of the multi-component solutions were measured in the limit of infinite dilution in n-hexane using a vibrating-tube densitometer at and . An experimental design in the concentration range 0.0015<x_solute-i<0.023 was explored, optimizing the metric distance among the solutes to avoid clustering. The partial molar volumes of methanol, acetone, and 2-butanol at infinite dilution determined from the multi-component data were very consistent with the values obtained from separate binary experiments. Next a total molar volume response surface model was developed. Only experimental total volume and component moles are needed for analysis. The partial molar volumes of all the solutes were accurately predicted from the multi-component data alone. A new expression for excess molar volume is proposed to express component interactions. This approach is undoubtedly of considerable usefulness for determination of the partial molar properties of non-isolated but observable species in multi-component reactive solutions.     

Comparison of dielectric constant meter with turbidity meter and focused beam reflectance measurement for metastable zone width determination

This work demonstrates a detailed process analytical technology (PAT) comparison study of dielectric constant measurement with turbidity measurement and focused beam reflectance measurement (FBRM) in detecting phase transitions during crystallization of three model solutions, namely stearic acid–ethyl acetate, paracetamol–ethanol and carbamazepine–methanol. The cloud and clear points determined by the dielectric constant measurement are found to be in close agreement with those obtained from the other two well-established PAT tools. A calibration technique can be further applied on the dielectric constant to improve the accuracy of the cloud point detection. The results have shown that the dielectric constant meter can be reliably used for metastable zone width (MZW) determination. This study opens new opportunities for the use of the dielectric constant meter as a simple and inexpensive alternative PAT tool for process monitoring of solution crystallization.     

Investigation of unusual shunting behavior due to phototransistor effect in n-type aluminum-alloyed rear junction solar cells

N-type silicon wafers have been found to offer numerous advantages over p-type silicon wafers, such that they are becoming more widely used for manufacturing high-efficiency commercial solar cells. This paper focuses on work done on n-type cell structures with a screen-printed aluminum-alloyed rear junction, laser-doped selective emitter and light-induced plated front contacts to suit large-scale commercial production. However, with such a cell structure we report unusual linear shunting behavior that is only present under illumination but disappears under dark conditions. It was shown that such a phenomenon can be represented by a phototransistor model. In fact, such shunting effects are found to have detrimental impacts on the cell short-circuit current density (J_sc) and fill factor (FF), which limits the efficiency of cells in this work to 12%.     

Antioxidant Characteristics of Hops and Hop Products

The method based on the reaction of stable DPPH radical proved to be the best for the determination of antioxidant characteristics of hops and hop products. Antioxidant activity is expressed as the rate of decline in absorbance of the reaction environment and assessed in relative percents. Differences in the values of antioxidant activity were determined in Czech and foreign hop varieties. The highest antioxidant activities in the scope of 70 to 80% rel. were measured in Saaz and Spalter Select. Antioxidant activity in most of the varieties moved in the scope of 40 to 60% rel. A part of antioxidant activity of hops is irreversibly lost in the course of drying. The loss does not usually exceed 5% of the original RA_DPPH value. Drying also resulted in a decrease of polyphenol compound contents. Drying in belt and chamber kilns is comparable from the point of view of preserving hop antioxidant properties. Results of determination of antioxidant activity in hot water extracts of raw hops and ground hops were comparable and statistically non‐significant. The same held true for pelletizing of ground hops. The antioxidant activity of raw hops declined in the course of long‐term storage in dependence on storage temperature. Storage temperature had no effect on the antioxidant activity of the hop pellets packed in a multi‐layer foil without air access.     

The determination of volumetric standard states and solute-solute interactions in competitive quaternary aqueous solutions using a self-consistent multivariate approach

A general methodology involving semi-batch experimental design is proposed in order to determine the volumetric standard states as well as homotactic and heterotactic volumetric solute-solute interaction coefficients from the associated quaternary solutions alone. The densities of quaternary aqueous solutions consisting of three alcohol solutes, e.g. methanol, ethanol, and 1-propanol, in the range of concentrations 0.0000<x_solute-i<0.0093 at 298.15 K and 0.1013 MPa were measured in order to demonstrate the utility of this methodology. The volumetric standard states as well as the interaction coefficients were determined from combined use of a multivariate response surface model together with the McMillan-Mayer formalism and a 3rd-order virial expansion, without relying on either pure component properties or binary/ternary solution information. Since no external measurements are admitted, additional sources of experimentally induced error are eliminated, and the associated numerical sensitivity of the excess volumetric equations is more appropriately treated. The volumes of interaction reveal that hydrophobic-hydrophobic interactions predominate. All homotactic and heterotactic interaction coefficients are negative and their magnitudes increase with increasing alcohol chain length. The coefficients obtained from quaternary-solution multivariate analysis are in good agreement with separate binary and ternary measurements reported in the literature. Such a general approach should provide new opportunities for the understanding of molecular recognition processes in complex solutions.     

The cost of lower self-esteem: Testing a self- and social-bonds model of health.

The authors draw upon social, personality, and health psychology to propose and test a self-and-social-bonds model of health. The model contends that lower self-esteem predicts health problems and that poor-quality social bonds explain this association. In Study 1, lower self-esteem prospectively predicted reports of health problems 2 months later, and this association was explained by subjective reports of poor social bonds. Study 2 replicated the results of Study 1 but used a longitudinal design with 6 waves of data collection, assessed self-reports of concrete health-related behaviors (i.e., number of visits to the doctor and classes missed due to illness), and measured both subjective and objective indicators of quality of social bonds (i.e., interpersonal stress and number of friends). In addition, Study 2 showed that poor-quality social bonds predicted acute drops in self-esteem over time, which in turn predicted acute decreases in quality of social bonds and, consequently, acute increases in health problems. In both studies, alternative explanations to the model were tested. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Does Every Inspection Really Need a Meeting?

Software review is a fundamental component of the software quality assurance process, yet significant controversies surround the most efficient and effective review method. A central question surrounds the use of meetings; traditional review practice views them as essential, while more recent findings question their utility. To provide insight into this question, we conducted a controlled experiment to assess several measures of cost and effectiveness for a meeting and non-meeting-based review method. The experiment used CSRS, a computer mediated collaborative software review environment, and 24 three person groups. We found that the meeting-based review method studied was significantly more costly than the non-meeting-based method, but that meeting-based review did not find significantly more defects than the non-meeting-based method. However, the meeting-based review method was significantly better at reducing the level of false positives, and subjects subjectively preferred meeting-based review over non-meeting-based review. This paper presents the motivation for this experiment, its design and implementation, our empirical findings, pointers to Internet repositories for replication or additional analysis of this experiment, conclusions, and future directions.