Effect of Brood Pheromone on Survival and Nutrient Intake of African Honey Bees (<Emphasis Type="Italic">Apis mellifera scutellata</Emphasis>) under Controlled Conditions

The influence of pheromones on insect physiology and behavior has been thoroughly reported for numerous aspects, such as attraction, gland development, aggregation, mate and kin recognition. Brood pheromone (BP) is released by honey bee larvae to indicate their protein requirements to the colony. Although BP is known to modulate pollen and protein consumption, which in turn can affect physiological and morphological parameters, such as hypopharyngeal gland (HPG) development and ovarian activation, few studies have focused on the effect of BP on nutritional balance. In this study, we exposed newly emerged worker bees for 14 d and found that BP exposure increased protein intake during the first few days, with a peak in consumption at day four following exposure. BP exposure decreased survival of caged honey bees, but did not affect either the size of the HPG acini or ovarian activation stage. The uncoupling of the BP releaser effect, facilitated by working under controlled conditions, and the presence of larvae as stimulating cues are discussed.     

The unique relationship between swell percent and swell pressure of compacted clays

Expansive soils exhibit high volumetric deformations, posing a serious threat to the stability of structures and foundations. However, measurement of swelling properties is time consuming and requires special and expensive equipment. This study made an attempt to investigate the relationship between these parameters and easily obtained soil properties using various clay mineral mixtures to obtain soils in a wide range of plasticity indices. Free swell percent was correlated to clay percent, water content, dry unit weight, plasticity index, liquidity index and cation exchange capacity using multiple regression analyses. A very high (R = 0.94) fit was also found for a proposed relationship between the percent swell and swell pressure values for samples having a swell pressure ≤300 kPa. It is concluded that the proposed equations offer a rapid and inexpensive substitute for laboratory testing of swell percent/swell pressure in the preliminary stages of site investigations.     

Investigation on Wear Behavior of Steels Coated with WC by ESD Technique

Protection of Metals and Physical Chemistry of Surfaces - Electro-spark deposition (ESD) or low energy welding (LEW) technique allows the coating of metallic materials with different metal and...     

Comparison of measured rain attenuation in the 10.982‐GHz band with predictions and sensitivity analysis

The campaign to collect rain attenuation data on terrestrial links had commenced in Malaysian tropical climates for almost two decades. The terrestrial data so far collected have been greatly utilized to derive useful statistics for various microwave applications, such as frequency scaling, rain rate conversion factor, 1‐min rain rate contour maps, wet antenna losses, and fade slope duration analysis. However, there is still severe scarcity of rain attenuation data on earth–space links in Malaysia. The results of the 2‐year measurement (January 2009–December 2010) of rain rates and rain‐induced attenuation in vertically polarized signals propagating at 10.982 GHz have been presented in this paper. The rain attenuation over the link path was measured at Islamic International University Malaysia and compared with ITU‐R P.618‐10 and Crane global models in this paper. The test results show that the two prediction models seem inadequate for predicting rain attenuation in the Ku‐band in Malaysia. Sensitivity analysis performed on measured data also reveals that the sensitivity variables depend on rain rate. Copyright © 2014 John Wiley & Sons, Ltd.     

Manipulating InAs nanowires with submicrometer precision

InAs nanowires are grown epitaxially by catalyst-free metal organic vapor phase epitaxy and are subsequently positioned with a lateral accuracy of less than 1 μm using simple adhesion forces between the nanowires and an indium tip. The technique, requiring only an optical microscope, is used to place individual nanowires onto the corner of a cleaved-edge wafer as well as across predefined holes in Si(3)N(4) membranes. The precision of the method is limited by the stability of the micromanipulators and the precision of the optical microscope.     

Effect of filler content on the structure‐property behavior of poly(ethylene oxide) based polyurethaneurea‐silica nanocomposites

Poly(ethylene oxide) (PEO) based polyurethaneurea‐silica nanocomposites were prepared by solution blending and characterized by Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, Differential Scanning Calorimetry and tensile testing. The colloidal silica nanoparticles with an average size of 50 nm were synthesized by modified Stöber method in isopropanol. Silica particles were incorporated into three cycloaliphatic polyurethaneurea (PUs) copolymers based on PEO oligomers with molecular weights of 2,000, 4,600, and 8,000 g/mol. Hard segment content of PUs was constant at 30% by weight. Silica content of the PU nanocomposites varied between 1 and 20% by weight. Soft segment (SS) glass transition and melting temperatures slightly increased with increasing filler content for all the copolymers. Degree of SS crystallinity first increased with 1% silica incorporation and subsequently decreased by further silica addition. Elastic modulus and tensile strengths of PU copolymers gradually increased with increasing amount of the silica filler. Elongation at break values gradually decreased in PEO‐2000 based PU copolymer with increasing silica content, whereas no significant change was observed in PUs based on PEO‐4600 and PEO‐8000. Enhancement in tensile properties of the materials was mainly attributed to the homogeneous distribution of silica filler in polymer matrices and strong polymer‐filler interactions. POLYM. ENG. SCI., 58:1097–1107, 2018. © 2017 Society of Plastics Engineers     

Investigation Anthropogenic Impacts and Climate Factors on Drying up of Urmia Lake using Water Budget and Drought Analysis

The water level of Urmia Lake, the largest inland lake in Iran with maximum water surface area of about 6000 km², has been shrinking for the last two decades. Although a number of study have been performed to determine drought condition and coastline changes of Urmia Lake, there has not been a detailed study to distinguish anthropogenic effects from climate impacts on the drying of Urmia Lake. In this study, water budget of Urmia Lake and the intensity of drought in the basin were analyzed in the period from 1985 to 2010 and a new hypothesis is proposed to quantify anthropogenic and climate impacts in reducing the volume of Urmia Lake. The results of this study indicate that human impacts on the Lake and its basin are more important than climate factors. Though previous studies assumed that ground water output from Urmia Lake is negligible, the results of this study show the presence of significant groundwater seepage from Urmia Lake. Major changes in the variables that reduced the water level of Urmia Lake were observed since 1998. Anthropogenic impacts and climate factors have roughly 80% and 20% effects on the drying up of Urmia Lake, respectively. Hence, the first step to recover Urmia Lake could be the revision of management surface water, operation of dams and groundwater resources. The second step could be the review and classification of agricultural products grown in the region in terms of water consumption and teach local people the best practice methods for irrigation.     

Symbiotic organisms search optimization algorithm for economic/emission dispatch problem in power systems

This paper presents symbiotic organisms search (SOS) algorithm to solve economic emission load dispatch (EELD) problem for thermal generators in power systems. The basic objective of the EELD is to minimize both minimum operating costs and emission levels, while satisfying the load demand and all equality–inequality constraints. In other research direction, this multi-objective problem is converted into single-objective function by using price penalty factor approach in order to solve it with SOS. The proposed algorithm has been implemented on various test cases, with different constraints and various cost curve nature. In order to see the effectiveness of the proposed algorithm, its results are compared to those reported in the recent literature. The results of the algorithms indicate that SOS gives good results in both systems and very competitive with the state of the art for the solution of the EELD problems.