Processing of nano boron carbide reinforced flexible polymer composites with improved shielding properties

Aims: The main objective of the current research is to develop light-weight and flexible electromagnetic shielding materials with improved properties using nano/mikro boron carbide dispersed into polymer based matrices after surface modification. Methods: Nano/micro boron carbide particles with various morphologies were synthesized by sol-gel techniques and the obtained particles were surface modified with different functional groups. After mixing the particles with different polymers using high shear mixer, shielding composite plates were shaped using injection moulding and warm pressing. Results: It was shown that sol-gel technique was able to produce boron carbide particles with controlled morphology and better shielding properties could be obtained using these particles within polymeric matrices leading to the formation of flexible composites. Conclusions: Overall, it was found that light-weight and effective shielding materials could be obtained using boron carbide particles dispersed within polymeric matrices. Surface modification of the particles is critical for good dispersion and hence to get better final properties. The concentration of the reinforcing particles also affects the properties in terms of energy absorption and shielding

Search efficiency, wage dynamics and welfare

Advances in information technology have improved the job-search process in the labor market. We analyze the effects of this improvement by constructing a search-and-matching model with two sectors: a risky sector with firm-specific productivity shocks and a risk-free sector. The risky sector is characterized by a low level of commitment between employers and workers - either party can end the employment relationship. We show that a better job-search process generates more job matches in the risky sector, and this benefits workers by improving their outside options. The effect on employers is subtle: while it is easier to fill vacancies, workers become more expensive. At the same time, the ease of finding new workers makes it harder for employers to keep their wage promises to workers and increases wage volatility. Our paper contributes to the literature by offering a novel explanation for the observed rise in wage volatility

Production and characterization of xylanases of a Bacillus strain isolated from soil

Xylanase production was performed by growing a Bacillus isolate on agricultural by-products, wheat straw, wheat bran, corn cobs and cotton bagasse. A maximum xylanase activity of 180 U/ml was obtained together with a cellulase activity of 0.03 U/ml on 4 (w/v) corn cobs. Electrophoretic analysis showed the presence of three endo-beta-1, 4-xylanases having molecular weights of about 22, 23 and 40 kDa. Xylanolytic activity was stable up to 50degreesC in the pH range of 4.5-10 and the highest activity was observed at 70degreesC and pH 6.5

Intercropping of corn with cowpea and bean: Biomass yield and silage quality

An experiment was carried out at the Bornova experimental fields of Field Crops Department of Agriculture Faculty., Ege Univ., Turkey during 2004-2005 growing season in order to determine biomass yield and silage quality of corn (Zea mays indendata) mixed with legumes such as various cowpea (Vigna ungiuculata) and bean (Phaseolus vulgaris) cultivars monocropped or intercropped in same or alternate-rows. Results indicated that intercropping system affected many characteristics such as plant height, fresh biomass and dry matter (DM) yield, pH level and crude protein (CP) content and yield of silage material. Intercropped corn withlegumes were far more effective than monocrop corn to produce higher DM yield and roughage for silage with better quality. Practicing alternate-row sowings and benefiting from climbing types of legumes as componentcrop had better performances than same-row sowings and dwarf type legume

Turf and playing quality traits of some new turfgrass alternatives in a mediterranean environment

In an attempt to investigate the turfgrass and playing quality characteristics of some newly introduced warm season turf grasses and traditional cool season sports turf mixture, classical and contemporary techniques were imposed on the turfgrass experimental plots of the research area of Department of Field Crops, Agriculture Faculty of Ege University, Bornova/Izmir/Turkey. Some warm season turfgrasses (Cynodon dactylon cv. SR9554, Cynodon dactylon x Cynodon transvaalensis cv. Tifway-419, Paspalum vaginatum cv. Sea Spray and Zoysia japonica cv. Zenith) and traditional cool season sports turf mixture were tested in terms of visual turf quality and playing quality traits (ball rebound, ball roll and shock absorption) on a monthly and seasonal bases for three years under Mediterranean environmental conditions. Significant variations were determined among the turfgrass alternatives in all traits except years. It was concluded that Tifway-419 and Sea Spray turf grasses were the most successful and promising alternatives compared to the other options under Mediterranean environmental conditions. © 2019, Society of Field Crops Science. All rights reserved.Türkiye Bilimsel ve Teknolojik Araştirma KurumuResearch study (112O130) funded by The Scientific and Technological Research Council of Turkey (TUBITAK). -

Performances of some cool season turfgrass species in mediterranean environment: I. Lolium perenne L., Festuca arundinacea Schreb., Poa pratensis L., and Agrostis tenuis Sibth

The commitment to turf research is more recent and is challenged by the diversity of climatic conditions occurring throughout the Anatolian peninsula in Turkey, thereby complicating the recommendation of species and cultivars. Assessing the peculiarities of turfs during the growing period and the efficient use of turf for establishing lawns requires field evaluation of the existing cultivars particularly in the sites with a Mediterranean climate. Our study is aimed at evaluating the adaptability and quality of the popular cultivars (introductions) of cool season turfgrass species in a Mediterranean site in western Turkey, Bornova/IZMIR. Six cultivars of perennial ryegrass (Lolium perenne L.), four cultivars of tall fescue (Festuca arundinacea Schreb.), four cultivars of Kentucky bluegrass (Poa pratensis L.) and four cultivars of colonial bentgrass (Agrostis tenuis Sibth) were tested for 3 years in a replicated experimental block group design. Turf cover, colour and quality traits of each cultivar in each species were evaluated by using a visual score (1-9) and assessed in each season from 2003 to 2005. Cultivars of tall fescue and to some extent perennial ryegrass species were better able than those of Kentucky bluegrass and colonial bentgrass to cope with the existing Mediterranean climatic condition. All species performed better in winter, spring and autumn than summer season, except for tall fescue. Kentucky bluegrass and colonial bentgrass cultivars were not found recommendable for Mediterranean environment

Performances of some cool season turfgrass cultivars in mediterranean environment: II. Festuca arundinacea Schreb., Festuca ovina L., Festuca rubra spp. rubra L., Festuca rubra spp. trichophylla Gaud and Festuca rubra spp. commutata Gaud

The commitment to turf research is more recent and is challenged by the diversity of climatic conditions occurring in Anatolian peninsula of Turkey. These differences in climatic factors and environmental variation may determine the specific adaptation of species to certain areas and complicate the species and cultivar recommendations. In this present study, aiming to evaluate the adaptability and quality of newly introduced cultivars of different cool season turfgrass species in a Mediterranean environment in western Turkey, Bornova-Izmir, four cultivars of Tall fescue (Festuca arundinacea Schreb), Sheep fescue (Festuca ovina L), Festuca rubra L. spp. trichophlylla Gaud (Slender creeping red fescue) and Festuca rubra spp. rubra commutata Gaud (Chewings red fescue) and six cultivars of Festuca rubra spp. rubra L. (Creeping red fescue) were tested for 3 years (2003-2005) in a replicated experimental block group design. Turf cover, colour and quality traits of these cool season turfgrass cultivars were evaluated by using a visual score (1-9) and the target of the generated information was the support turfgrass specialist in turfgrass cultivars selection and recommendations and research institutions for their breeding programs. Results indicated that tall fescue cultivars were the only genotypes maintaining high scores of cover, colour and quality in different seasons and years. Sheep fescue cultivars were also consistent throughout the experimental years, although their colour, cover and quality scores were not high. We also suggested that all red fescue sub-species were not fully adaptable to Mediterranean conditions and their usage had to be limited in turf mixtures