A combined physicochemical and electrocatalytic study of microwave synthesized tungsten mono-carbide nanoparticles on multiwalled carbon nanotubes as a co-catalyst for a proton-exchange membrane fuel cell

Tungsten mono-carbide (WC) nanoparticles supported on multiwalled carbon nanotube (MWCNT) was synthesized by a microwave-assisted solid-state carburization. The prepared samples were used as a co-catalyst to prepare Pt-WC/MWCNT catalyst for a proton-exchange membrane fuel cell. MWCNTs with and without oxidative pretreatments were characterized as the starting precursors. The influence of the carbide formation conditions on the physicochemical characteristics of the final product were extensively investigated. According to the results, surface pretreatment of the MWCNTs can improve the yield of carbide formation. Furthermore, carburization process can improve the catalyst utilization due to increasing the number of surface defects of the MWCNT supporting materials which can be interpreted as structural effect of the carburization process. It is believed that the superior performance of electrodes modified with tungsten carbide is mostly due to the structural effect of the carburization process and synergistic effect between the electrocatalytic activity of WC and Pt.     

Effect of different levels of fat and inulin on the microbial growth and metabolites in probiotic yogurt containing nonviable bacteria

Effects of different levels of fat and inulin on bacterial cell counts, degree of proteolysis and concentrations of organic acids in the yogurt containing inactivated cells of probiotic strains Bifidobacterium animalis and Lactobacillus acidophilus were investigated. Results showed that both L. acidophilus and B. animalis grew well in the yogurt samples reaching cell counts higher than 10⁶ CFU mL^?1 at the final pH of 4.5. Inulin at the concentration of 1% had no significant effects on the production of organic acids and cell counts of L. acidophilus, but promoted the growth of B. animalis with a reduction in the degree of proteolysis. Generally, different fat levels showed significant effects on the production of organic acids and nonsignificant effects on the cell counts of probiotic bacteria and degree of proteolysis. In case of lactic acid, the ratio of L‐ (+)to D‐ (?) isomer ranged from 50/50 to 80/20 in yogurt samples.     

Incorporating essential oils of marjoram and rosemary in the formulation of beef patties manufactured with mechanically deboned poultry meat to improve the lipid stability and sensory attributes

The effect of addition of essential oils of marjoram (Origanum marjorana L.) and rosemary (Rosmarinus officinalis L.) at concentration of 200 mg/kg to beef patties formulated with 200 g/kg mechanically deboned poultry meat (MDPM) was studied. The proximate composition, lipid oxidation, sensory characteristics and microbial counts of beef patties manufactured with 200 g/kg MDPM (percentage of lean portion) were assessed during frozen storage at ?18 °C. Beef patties formulated with MDPM (200 g/kg) showed significant (P < 0.05) reduction in protein content and significant (P < 0.05) increase in fat content. Incorporating MDPM in beef patties formulation significantly (P < 0.05) increased the TBARS (Thiobarbituric acid reactive substance) values and significantly (P < 0.05) reduced the flavor and overall acceptability scores. Addition of essential oils of marjoram and rosemary at level of 200 mg/kg significantly (P < 0.05) reduced the TBARS and significantly (P < 0.05) increased the sensory scores of beef patties during frozen storage period. Overall, the study indicated the potential use of natural herbal essential oils to protect against lipid oxidation and improve the sensory attributes of beef patties formulated with MDPM.     

Separation and preconcentration of La from monazite, followed by determination using nondestructive γ-ray spectrometry

A method was developed for separation, preconcentration, and determination of La by its radioactive isotope ¹³⁸La using an HPGe detector. The method was checked by comparison with ICP-MS. The detection limit (minimum detection activity) is 1.46 and 1.52 Bq kg^?1 at 788.4 and 1435.8 keV lines, respectively. The Th(IV) and U(VI) are separated by precipitation. To separate Ac(III), it is extracted jointly with REEs from 0.1 M HNO₃ with HDEHP and then stripped with 0.2 M HNO₃, with REEs remaining in the organic phase. Lanthanum in a mixture with REEs is determined by ??-ray spectrometry.     

A branch and bound enhanced genetic algorithm for scheduling a flowline manufacturing cell with sequence dependent family setup times

This paper addresses the permutation flowline manufacturing cell with sequence dependent family setup times problem with the objective to minimize the makespan criterion. We develop a cooperative approach including a genetic algorithm and a branch and bound procedure. The latter is probabilistically integrated in the genetic algorithm in order to enhance the current solution. Moreover, the application of the branch and bound algorithm is based upon the decomposition of the problem into subproblems. The performance of the proposed method is tested by numerical experiments on a large number of representative problems.     

The role of advertisements in the marketing of gated communities as a new Western suburban lifestyle: a case study of the Greater Cairo Region, Egypt

This paper examines the advertising themes and rhetoric that have been assembled in the marketing of the Greater Cairo Region’s (GCR) newly built gated communities. We demonstrate how place-marketing strategies, in this case, selling the Egyptian dream home, draws upon specific landscape offerings and values. It shows how aspects of globalization interact with processes of urbanization in the GCR to create new landscapes of housing consumption. The globalization of mass media has influenced consumption preferences and brought new consumption choices to the GCR’s residents. This study concludes that the demand for gated communities in the GCR, in large part, has been created by developers who foster an image of these areas as symbols of ‘modernism’ and Western lifestyles. Underlying these sales efforts is the common assumption held by developers, potential buyers and segments of the larger society that the lifestyles of Western urbanization should naturally emerge as the result of economic development.     

Design and experimental analysis of new industrial vibration dampers

Vibration dampers are the first line of defense against shock and impacts sustained by mechanical and structural systems. Consequently, for decades, new impact damping technologies have been developed and applied in several engineering fields to attenuate undesired vibrations. Linear particle chain (LPC) impact dampers are the latest category of impact dampers being developed for the mitigation of unwanted vibrations in many systems. However, the challenges associated with prototyping such devices made their application in practical systems very limited. This paper proposes five innovative designs for the LPC impact dampers satisfying a wide range of industry needs in terms of efficiency, cost, and sustainability. The proposed designs are fabricated and tested under the same conditions to assess their efficiency in attenuating the vibration of a simple structure. Each design showed consistent behavior, but some designs outperformed others depending on the geometry, physical characteristics, and type of structure. The detailed design, experimental study, and time response comparisons are presented here to provide an initial study towards the development of practical sustainable LPC vibration dampers for real engineering applications.     

6-Pentyl-2H-pyran-2-one: A Potent Peach-Derived Kairomone for New Zealand Flower Thrips,Thrips obscuratus

New Zealand flower thrips, Thrips obscuratus (Thysanoptera: Thripidae), are attracted to ripening fruits, especially peaches. Volatiles from unripe and ripe peach fruits were collected and analyzed by gas chromatography/mass spectrometry. Six lactones were found only in ripe peach volatiles: γ-heptalactone, γ-octalactone, γ-nonalactone, 6-pentyl-2H-pyran-2-one, γ-decalactone, and δ-decalactone. When these compounds were tested individually in field-trapping experiments, three of them (γ-octalactone, γ-nonalactone, and 6-pentyl-2H-pyran-2-one) attracted New Zealand flower thrips. In another field-trapping experiment, aimed at testing various combinations of the three active compounds, no synergistic effects were found among all combinations tested; no combination caught more thrips than 6-pentyl-2H-pyran-2-one, alone. A further field-trapping experiment was conducted to determine the dose (10, 100, and 500 mg) of 6-pentyl-2H-pyran-2-one that gave the greatest catch of T. obscuratus, while also comparing it against another attractant, ethyl nicotinate, for T. obscuratus. The greatest catches in traps baited with either attractant were at loadings of 500 mg. At both 10 and 500 mg, traps baited with 6-pentyl-2H-pyran-2-one caught more T. obscuratus than those baited with the same amounts of ethyl nicotinate. 6-Pentyl-2H-pyran-2-one is a potent attractant for New Zealand flower thrips and, therefore, could be used for monitoring and control of New Zealand flower thrips. Work is underway developing monitoring and control options utilizing 6-pentyl-2H-pyran-2-one for this important pest.