Moisture absorption effect on thermal, dynamic mechanical and mechanical properties of injection-molded short glass-fiber/polyamide 6,6 composites

Polymer composites of polyamide 6,6 reinforced with short glass fiber were prepared by injection molding, conditioned under dry, 50 % relative humidity and wet. Investigations by DSC, DMA and tensile tests were conducted. FLD study showed that more fiber degradation occurred during processing of the composites with higher fiber loading. DSC analysis revealed that the incorporation of glass fiber and moisture into the PA 6,6 matrix resulted in a remarkable decrease in the degree of crystallinity. DMA results revealed the glass transition temperatures were sensitive to moisture absorption and their values moved to a lower temperature upon exposure to moisture. Incorporation of glass fiber into the polyamide 6,6 gave rise to a significant improvement in tensile modulus and tensile strength, while tensile strain was reduced. Exposure to different environments from dry to wet conditions resulted in a decrease in the strength and modulus, while tensile strains decreased.     

Protein-binding affinity of leucaena condensed tannins of differing molecular weights

Depending on their source, concentration, chemical structure, and molecular weight, condensed tannins (CTs) form insoluble complexes with protein, which could lead to ruminal bypass protein, benefiting animal production. In this study, CTs from Leuceana leucocephala hybrid were fractionated into five fractions by a size exclusion chromatography procedure. The molecular weights of the CT fractions were determined using Q-TOF LC-MS, and the protein-binding affinities of the respective CT fractions were determined using a protein precipitation assay with bovine serum albumin (BSA) as the standard protein. The calculated number-average molecular weights (M(n)) were 1348.6, 857.1, 730.1, 726.0, and 497.1, and b values (the b value represents the CT quantity that is needed to bind half of the maximum precipitable BSA) of the different molecular weight fractions were 0.381, 0.510, 0.580, 0.636, and 0.780 for fractions 1, 2, 3, 4, and 5, respectively. The results indicated that, in general, CTs of higher molecular weight fractions have stronger protein-binding affinity than those of lower molecular weights. However, the number of hydroxyl units within the structure of CT polymers also affects the protein-binding affinity.     

Feeding Aspergillus awamori reduces skeletal muscle protein breakdown and stimulates growth in broilers

This study was conducted to show that dietary supplementation of a fungus, Aspergillus awamori called Koji in Japan, reduces skeletal muscle protein breakdown and stimulates growth in broiler chickens. A total of 30 chicks at 15 days of age was divided into control and two treatment groups (10 birds per treatment). Control group was fed basal diet and treatment groups were fed the basal diets supplemented with A. awamori at levels of 0.05% and 0.2%. The birds were raised for 12 days from 15 to 27 days of age and then the effect on growth, organ weights and plasma 3‐methylhistidine concentration and digestibilities of protein and energy was evaluated. The messenger RNAs (mRNAs) of atrogin‐1, ubiquitin, proteasome, m‐calpain, µ‐calpain, β‐actin, myosin and pax‐7 in the breast muscle were also measured. Body weight gain and breast muscle weight were increased, although feed intake was decreased by the fungus and thus feed efficiency was increased. Protein and energy digestibilities were increased. Furthermore, plasma 3‐methylhistidine concentration was decreased by the fungus. The mRNAs of atrogin‐1, ubiquitin, proteasome, m‐calpain and µ‐calpain were all decreased. The mRNA of β‐actin but not myosin and pax‐7 was slightly increased by the fungus. In conclusion, feeding A. awamori improves growth performance because skeletal muscle proteolytic activity is reduced and digestibilities of energy and protein are increased.     

Grain filling pattern of Hordeum vulgare as affected by salicylic acid and salt stress

Although application of salicylic acid (SA) to various plants grown on saline soils has been examined adequately, the effect of SA on changes during grain filling period has not been studied in details. In this 2-year field study, the grain-filling pattern of barley has been monitored as affected by different SA concentrations (0, 0.5, 1.0, 1.5, and 2.0?mM) under varied irrigation salinity levels (2 and 12?dSm^?1) during 2012–2013 and 2013–2014 growing seasons. In both years, total soluble carbohydrates (TSC) increased up to 15?days after anthesis (DAA) and then decreased until the end of the grain-filling period. However, starch content (SC) and the mean grain weight (MGW) increased form the first sampling, and such increase was substantial between 15 and 25 DAA. The grain growth rate (GGR) and the absolute grain growth rate (AGGR) were enhanced up to 20 DAA and then were reduced until 30 DAA. The grain-filling pattern changed by salt stress, so that TSC was greater for the salt stressed plants from 15 or 10 DAA in the first and the second years, respectively. Throughout the grain-filling period, SC, MGW, and AGGR were lower under saline conditions in both years. Application of SA increased TSC, SC, MGW, GGR, and AGGR from 15 to 20 DAA, however, the effect of SA was obvious earlier under saline than the non-saline conditions. Generally, it can be concluded that SA foliar application might increase grain weight through modulating the negative impact of salt stress on carbohydrate and starch contents. It also appeared that the effect of SA was obvious earlier under salt stress conditions.     

Earthworms as ecosystem engineers and the most important detritivors in forest soils

Earthworms are considered as soil engineers because of their effects on soil properties and their influence on the availability of resources for other organisms, including microorganisms and plants. However, the links between their impacts on the soil environment and the resulting modification of natural selection pressures on engineer as well as on other organisms have received little attention. Earthworms are known to have a positive influence on the soil fabric and on the decomposition and mineralization of litter by breaking down organic matter and producing large amounts of fasces, thereby mixing litter with the mineral soil. Therefore, they play an important part in changes from one humus from to another according to forest succession patterns. Consequently, they are also expected to be good bio-indicators for forest site quality and are thus useful when planning forest production improvement. Earthworm's populations are as indicator that in exploited regions is destruction indicator and reclamation plans is nature return indicator. In this study we summarized the current knowledge in relation to earthworm's ecology in forest soils as ecosystem engineers.     

Impact properties of glass-fiber/polypropylene composites: The influence of fiber loading, specimen geometry and test temperature

Glass fiber reinforced polypropylene composites were compounded with a twin-screw extruder and injection molded. Fiber length distribution study showed that more fiber degradation occurred during processing of the composites with higher fiber loading. Dynamic mechanical analysis carried out showed that magnitudes of storage and loss modulus of composites are improves with the presence of the glass fiber in the system. The incorporation of fibers into the composites has slightly shifted the glass transition temperature to lower values. On the other hand, the presence of the glass fiber reduces the magnitude of tan δ at α-transition dramatically due to the strengthening effect by the fibers. From impact test, it was found that increment in glass fiber loading leads to an increase in peak load, critical strain energy release rate and critical stress intensity factor indicating the improvement in the material toughness. However, there was no significant change observed in fracture energy. With respect to increasing in specimen geometry, despite an improvement in peak load and fracture energy of the impact specimen, the critical strain energy release rate and critical stress intensity factor values were decreased. On the other hand, increase in test temperature resulted in reduction of peak load and critical stress intensity factor due to increment in material ductility, whereby fracture energy and critical strain energy release rate improved.     

Changes in soil chemistry and element uptake by Oak seedlings after application of soil amendment

ABSTRACT

The purpose of this study is to investigate the effect of cellulosic wastes and nanoscale zero-valent iron (nZVI) on the soil properties and the nutrient uptake by Quercus castaneifolia C.A.Mey seedlings. The seedlings were planted in pots (unpolluted soil) and cadmium (Cd) was added to the pots in three concentrations (10, 20, 30?mg.kg^?1). Cellulosic wastes were mixed with the soil (at the same time as the planting) in four levels (W: 0, 10, 20, 30?g.100g^?1 soil). The reduction method was used to prepare nZVI, then the nanoparticles were injected into the polluted pots in four levels (N: 0, 1, 2, and 3?mg.kg^?1). The lowest concentration of Cd in leaves, stems and roots and for all the contamination levels was observed in N3. All the cellulosic wastes and N3 significantly increased the soil pH at all the levels of contamination. An increasing trend of the soil carbon (C) content was observed by adding the cellulosic wastes. The highest pH and C content were observed in W3. The lowest bioavailable Cd contents for all the contamination levels was observed in N3. According to the results, nZVI and cellulosic wastes could help the plants establishing in heavy metal-polluted lands.     

Study the Physical,Chemical, Mineralogical,and Geo-technical Properties of Soils Used in Pottery Industries,Kurdistan-lraq

The study area is located in Duhok and Sulaimania province in Kurdistan region, lraq. Study soils developed from parent material that has derived from limestone. Randomize, composed and disturbed surface soil samples were collected. The bulk soils were air dried, crushed and passed through 2 mm sieve. Standard methods were used for chemical, physical, geotechnical and mineralogical analyses of soil samples. The results indicated that the study soils texture were clay to loam clay, this texture was considered as suitable for ceramic and pottery industries as a result of increasing clay contents that ranged between 301 g/kg and 676 g/kg. Soil consistence depending on geotechnical properties increased the ability of study soils for resistance rapture and deformation. Existence the high amount of cementing agents in study soils such as organic matter, iron oxides and particularly total carbonate （247.2-308.8 g/kg） act to reduce the bad effect of the smectite minerals group （high shrinkage） in soils of study locations through increasing the resistance of these soils for rupture and deformation. The existing of Kaolinite, palygorskite and chlorite allows clay to be dried in ceramic and pottery industries without cracking from shrinkage. Study soils were different in their colors as a result of existence, different pigmentation materials that led to coloring soils with different colors in turn caused coloring of pottery and ceramic materials. Since, there are no available academic studies or researches about this subject in Kurdistan region in addition the clay pottery and ceramic sector still has a good market at the same time using this type of soils for arts, therefore, this study was conducted.     

Dietary Supplementation of Brown Seaweed and/or Nucleotides Improved Shrimp Performance,Health Status and Cold-Tolerant Gene Expression of Juvenile Whiteleg Shrimp during the Winter Season

This study was aimed to evaluate the efficiency of Sargassum polycystum and nucleotides- supplemented diets to improve immune response and cold-tolerance of juvenile Litopenaeus vannamei. Four treatments were evaluated: T1, the control, shrimp received only a basal diet; T2, a basal diet with 500 ppm nucleotides; T3, a basal diet with 500 ppm S. polycystum powdered; T4, a basal diet with 500 ppm nucleotides and 500 ppm S. polycystum powdered. Shrimp were fed experimental diets for 56 days. Results revealed shrimp fed T4 diet exhibited the best significant improvement in water quality, survival, growth, and feed utilization indices followed by T2, and T3, while T1 showed the worst values. Additionally, nonspecific immune responses (phagocytosis (%), lysozyme, phenoloxidase, super oxide dismutase (SOD) activity, total nitric oxide) were improved with 1.7–3.2-fold in T4 higher than T1. Histomorphology of hepatopancreas in T4 showed the most increased activation of the hepatic glandular duct system compared with the other treatments. Moreover, nucleotides/seaweed-supplemented diets upregulated relative expression of cMnSOD, Penaeidin4, and heat shock protein70 (HSP70) genes, while translationally controlled tumor protein (TCTP) was downregulated. In conclusion, the synergistic effects of both S. polycystum and nucleotides have many advantages as a growth promoter, immunostimulant, antimicrobial, and cold-tolerant stimulant to L. vannamei.