Study of the properties of compatibilized ABS/PA6 blends using response surface methodology

Styrene‐(maleic anhydride) copolymer (SMA) compatibilized blends of acrylonitrile‐butadiene rubber (ABS) and polyamide 6 (PA6) with a variety of compositions and compatibilizer levels were prepared at various screw speeds in a corotating twin screw extruder. A Box–Behnken model for three variables, with three levels, was chosen as an experimental design, and the mechanical properties of the blends were considered as the responses. Each response was analyzed and formulated versus the considered factors by the use of response surface methodology. Impact resistance increased with increased SMA concentration and reduced screw speed. In compatibilized samples, with an increase in PA6 content, higher impact resistance was observed. Increasing PA6 content and SMA concentration, as well as decreasing screw speed, gave improvements in both tensile and flexural strengths. In each case, all of the correlations among factors were studied. Grafting of SMA was proved by detecting the graft copolymer (SMA‐PA6) formed through extraction in formic acid and FTIR spectroscopy. Compared with uncompatibilized blends, compatibilized samples displayed more uniform and finer particle sizes, thereby proving the compatibilizing effect of the graft copolymer. The asymmetry trend in dispersed particle size before and after the phase inversion became more differentiated in the presence of the compatibilizer. Adding SMA lowered the phase inversion composition (based on PA6), whereas higher screw speed increased it. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers     

Supplementation effects of pomegranate by-products on oxidative status,metabolic profile,and performance in transition dairy cows

Recent studies demonstrated a high antioxidant capacity for pomegranate components due to their rich bioactive compounds, such as conjugated fatty acids and phenolics. The objective of the present study was, therefore, to assess whether pomegranate seed or pomegranate seed pulp (peel + seed) supplementation could be effective to improve antioxidant status, and hence metabolic profile and performance in periparturient dairy cows. After a 1-wk pretreatment period, Holstein cows (primiparous n = 12, multiparous n = 18) were assigned to 3 dietary treatments from 25 d before expected calving through 25 d postcalving. The dietary treatments included (1) control (CON); (2) diet supplemented with pomegranate seeds (PS; 400 g/cow per day); and (3) diet supplemented with pomegranate seed pulp (PSP; 400 g of seeds/cow per day + 1200 g of peels/cow per day). Compared with CON, supplementation with either PS or PSP had no effects on dry matter intake, rumen fermentation, and plasma concentrations of cholesterol, total protein, globulin, and aspartate amino transferase, but enhanced plasma total antioxidant activity, and lowered triacylglycerol, free fatty acids (FFA), and β-hydroxybutyrate at both pre- and postpartum periods. Plasma concentration of glucose, albumin, malondialdehyde (MDA) and blood superoxide dismutase (SOD) activity were not affected by dietary treatments at prepartum, whereas SOD activity increased and glucose, albumin, MDA, and FFA-to-albumin ratio decreased by feeding both by-products at postpartum period. In contrast to PS, supplementing PSP resulted in a greater decrease in plasma glucose and triacylglycerol concentration and higher increase in SOD activity. Energy- and fat-corrected milk yields were higher in cows fed PSP diet compared with those fed CON or PS diets, but content of milk fat, protein, and lactose were similar across the dietary treatments. These findings indicated that dietary pomegranate by-products supplementation, in particular PSP, could improve antioxidant status, which was associated with a decline in lipid oxidation (FFA and β-hydroxybutyrate) and peroxidation (MDA) and an enhancement in glucose utilization as well as fat-corrected milk yield.     

Bipotential deposition of nickel–cobalt hexacyanoferrate nanostructure on graphene coated stainless steel for supercapacitors

Graphene oxide (GO) was deposited on inexpensive and mechanically stable stainless steel (SS) electrode by electrophoretic deposition (EPD) technique. GO was reduced electrochemically in NaNO₃ to obtain electrochemically reduced graphene oxide (ERGO). Next, Hybrid nickel–cobalt hexacyanofarrate (NiCoHCF) nanoparticles were deposited from solution containing Ni⁺² and Co⁺² with ratio of 1:1 on ERGO/SS by bipotential method. Morphological investigation of prepared sample by scanning electron microscopy showed the presence of nanoparticles with diameters in the range of 15–50 nm. Crystal structure of nanocomposite was investigated by X-ray diffraction technique. Electrochemical behavior of prepared film indicates that hybrid nanocomposite has higher specific capacitance (411 F g⁻¹) than ERGO (185.2 F g⁻¹) in KNO₃ solution at current density of 0.2 A g⁻¹. In other words, pseudocapacitor that is formed based on the faradaic behavior of NiCoHCF can improve the capacitive performance of ERGO.     

Iron-deficiency anemia among children in southwest Iran

BACKGROUND: Iron deficiency is a major health problem worldwide and especially in developing countries. Iron-deficiency anemia has adverse effects on the development of children. OBJECTIVE: The purpose of this study was to determine the prevalence of iron-deficiency anemia in children under 5 years of age in southwest Iran. The study also sought to investigate the association between socioeconomic, demographic, cultural, and nutritional factors and iron-deficiency anemia in the selected area. METHODS: A randomized, cross-sectional study was performed of children 6 to 59 months of age living in urban and rural areas of Ahwaz District in Khuzestan Province. At eight randomly selected health centers, the children's height (or length) and weight were measured, and information on length and weight at birth was obtained from growth charts. Blood samples were taken from 337 randomly selected children. RESULTS: The results showed that 43.9% of the children had anemia and 29.1% iron-deficiency anemia. The highest prevalence of iron-deficiency anemia was in the 12- to 24-month age group. In the urban areas, infants 6 to 11 months of age had the highest prevalence of iron-deficiency anemia. CONCLUSIONS: The high prevalence of iron-deficiency anemia among children in southwest Iran indicates a major nutrition and health problem.     

Enhanced Evaporation in a Multilayer Porous Media Under Heat Localization: A Numerical Study

Evaporation and steam generation are two of the most vital processes in industry. A new method to advance the efficiency of evaporation involves localizing heat at the water surface where the vapor escapes into the air to minimize energy loss. In this research, we numerically investigate the improvement of a novel evaporation process via solar heat localization in a porous medium. A layer of carbon foam with a combination of interconnected and dead-end pores with a high hydrophilicity surface adjacent to a layer of expanded graphite with known porosity and properties were modeled numerically using a finite volume method. The hydrophilic porous media facilitates the capillary forces for better transportation of the bulk water through the porous media to the top surface of the porous media where the absorbed solar energy is delivered to the water inside the pores for evaporation. Continuity, momentum, heat and mass transfer equations were solved in this modeling effort. The modeling results were validated with the experimental data available in the literature. The findings in this numerical study can shed light on the complex interplay between the fluid dynamics and heat and mass transfer across the porous medium, which are important for efficient evaporation processes.     

Effect of different fat supplements on performance of dairy calves during cold season

The objective of this experiment was to evaluate the effects of starter supplementation with fat sources differing in their fatty acid (FA) profile on performance of dairy calves during cold season. Sixty Holstein calves (3 d of age; 39.7 ± 3.8 kg of body weight) were randomly assigned to 1 of 5 starter diets supplemented with (1) no fat or oil source (control), (2) 3% palm fat (PLF), (3) 3% soybean oil (SBO), (4) 3% tallow (TAL), and (5) a 3.2% mixture (MIX) of PLF, SBO, and fish oil. The fat supplements were substituted for corn in the basal starter diet. Both the control and fat-supplemented diets contained similar amounts of dietary crude protein (19.4%), but the latter had a slightly higher quantity of calculated metabolizable energy (3.17 vs. 3.07 Mcal/kg) than did the former. Calves were reared outdoor in individual pens during the cold of winter with a mean ambient temperature of 5.0°C during the study period. Whole milk was offered twice daily from d 3 to 45 and once from d 46 to 49. The animals were weaned on d 50 and monitored in their individual pens until d 70. Supplementation with SBO and MIX increased both the dietary concentration and ratio of essential FA (n-6 and n-3), whereas supplementation with TAL and PLF made no change in the essential FA profile. Starter intake and average daily gain were not affected by PLF and TAL supplements, but were reduced as a result of feeding MIX. Feeding supplemental SBO did not affect starter intake, but tended to improve average daily gain and final body weight. Fat sources had no effects on body skeletal measurements, fecal score, digestibility, ruminal pH, ammonia, and total volatile FA concentrations; however, feeding MIX increased rumen molar proportion of propionate. No differences were observed in blood metabolites across the treatments during the preweaning period. Plasma concentrations of triacylglycerol and cholesterol increased when fat sources were supplemented and glucose concentration increased when SBO was supplemented during the postweaning period. Overall, addition of 3% PLF or TAL to the diet of young calves failed to improve growth performance. Although addition of SBO and MIX increased the dietary essential FA concentration, calf performance was only improved when SBO was supplemented.     

Exopolysaccharide from Pantoea sp. BCCS 001 GH isolated from nectarine fruit: production in submerged culture and preliminary physicochemical characterizations

Food Science and Biotechnology - Exopolysaccharide (EPS), as potential microbial base polysaccharide source, has plenty of applications due to its unique physicochemical structure. A Pantoea sp....     

Chemical composition,antibacterial and antifungal activities of seed essential oil of Ferulago angulata

The aim of this study was to determine the chemical composition and the in vitro antimicrobial effects of seed essential oil of Ferulago angulata. The oil analyses by GC and GC/MS resulted in the identification of 39 compounds representing 91.07% of the oil. The major constituents were (Z)-β-ocimene (19.93%), α-pinene (15.50%), p-cymene (7.67%), sabinene (7.49%), β-phellandrene (5.5%), and α-phellandrene (4.95%). The oil was also screened for its antimicrobial properties against six bacteria (Erwinia amylovora, Xanthomonas oryzae, Pseudomonas syringae, Pectobacterium carotovorum, Ralstonia solanacearum, Bacillus thuringiensis) and six fungi (Alternaria alternata, Culvularia fallax, Macrophomina phaseolina, Fusarium oxysporum, Cytospora sacchari, Colletotrichum tricbellum). According to the results of antibacterial activity, B. thuringiensis (with 8 µL mL^?1 minimal inhibitory concentration (MIC) and 15 µL mL^?1 minimum bactericidal concentration (MBC)) was the most sensitive bacterium; P. carotovorum and R. solanacearum (with 20 µL mL^?1 MIC and 30< MBC) were the most resistant bacteria. Additionally, a broad differentiation against all of the tested fungi showed that the most susceptible and resistant fungi after 6 days at the highest concentration (800 µL L^?1) were F. oxysporum (100.0 ± 0.00%) and C. tricbellum (52.50 ± 1.67%) of growth inhibition, respectively.     

Chemical Composition and Antibacterial Activity of Essential Oils of Iranian Herbs Against Staphylococcus Aureus Isolated from Milk

Chemical composition and antibacterial activity of essential oils from three endemic plants including, Thymus daenensis Celak, Dracocephalum multicaule Montbr & Auch., Satureja bachtiarica Bunge and one native plant, Tanacetum polycephalum Schultz-Bip were determined. Volatile oils analyzed using gas chromatography and gas chromatography-mass spectrometry. The in-vitro antibacterial activity was performed by agar disc diffusion and micro-dilution assays. The results revealed distinct differences in the compounds depending on sample plant. Among the plant species screened, essential oils of S. bachtiarica and T. daenensis showed highest antibacterial activity against Staphylococcus aureus.