Fabrication of superparamagnetic adsorbent based on layered double hydroxide as effective nanoadsorbent for removal of Sb (III) from water samples

In this study, the superparamagnetic adsorbent as Fe@Mg‐Al LDH was synthesised by different methods with two steps for the removal of heavy metal ions from water samples. An easy, practical, economical, and replicable method was introduced to remove water contaminants, including heavy ions from aquatic environments. Moreover, the structure of superparamagnetic adsorbent was investigated by various methods including Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, and vibrating sample magnetometer. For better separation, ethylenediaminetetraacetic acid ligand was used, forming a complex with antimony ions to create suitable conditions for the removal of these ions. Cadmium and antimony ions were studied by floatation in aqueous environments with this superparamagnetic adsorbent owing to effective factors such as pH, amount of superparamagnetic adsorbent, contact time, sample temperature, volume, and ligand concentration. The model of Freundlich, Langmuir, and Temkin isotherms was studied to qualitatively evaluate the adsorption of antimony ions by the superparamagnetic adsorbent. The value of loaded antimony metal ions with Fe@Mg‐Al LDH was resulted at 160.15 mg/g. The standard deviation value in this procedure was found at 7.92%. The desorption volume of antimony metal ions by the adsorbent was found to be 25 ml. The thermodynamic parameters as well as the effect of interfering ions were investigated by graphite furnace atomic absorption spectrometry.     

Combining replication and checkpointing redundancies for reducing resiliency overhead

We herein propose a heuristic redundancy selection algorithm that combines resubmission, replication, and checkpointing redundancies to reduce the resiliency overhead in fault‐tolerant workflow scheduling. The appropriate combination of these redundancies for workflow tasks is obtained in two consecutive phases. First, to compute the replication vector (number of task replicas), we apportion the set of provisioned resources among concurrently executing tasks according to their needs. Subsequently, we obtain the optimal checkpointing interval for each task as a function of the number of replicas and characteristics of tasks and computational environment. We formulate the problem of obtaining the optimal checkpointing interval for replicated tasks in situations where checkpoint files can be exchanged among computational resources. The results of our simulation experiments, on both randomly generated workflow graphs and real‐world applications, demonstrated that both the proposed replication vector computation algorithm and the proposed checkpointing scheme reduced the resiliency overhead.     

Indirect Measurement of Hydrocarbon Aerosols Across the United States by Nonsulfate Hydrogen-Remaining Gravimetric Mass Correlations

In order to determine the levels of fine organic aerosols at remote sites, two methods were devised to calculate organic concentration from data collected on chemically inert teflon filters by the 34-site National Park Service (NPS) Fine Particle Network from 1982 to 1986. The remaining mass method is based on the difference between the measured gravimetric mass and the sum of the ammonium sulfate, soil, and soot carbon components, derived from measured parameters. This remaining mass is between 53% and 67% organic matter, based on two studies measuring organic carbon directly in the arid west. The nonsulfate hydrogen method is based on the concentration of particulate hydrogen, which has been measured on NPS samples since 1984, using techniques developed at Davis, CA. After removing the contribution associated with ammonium sulfate, the remaining nonsulfate hydrogen is predominantly due to organic matter. The two methods are in good agreement, with a sample to sample correlation of 0.76. For each western site, the average estimate by remaining mass is 1.2?1.5 times the average estimate by nonsulfate hydrogen, depending on the choice of organic fraction in the remaining mass. For all 28 western sites, the average organic concentration by the remaining mass method is between 0.75 and 0.95 μg/m³, as compared to 0.65 μg/m³ by the nonsulfate hydrogen method. The results are compared to those of other studies of organic matter in the west.     

Particulate emission factors for mobile fossil fuel and biomass combustion sources

PM emission factors (EFs) for gasoline- and diesel-fueled vehicles and biomass combustion were measured in several recent studies. In the Gas/Diesel Split Study (GD-Split), PM_2.5 EFs for heavy-duty diesel vehicles (HDDV) ranged from 0.2 to ~ 2 g/mile and increased with vehicle age. EFs for HDDV estimated with the U.S. EPA MOBILE 6.2 and California Air Resources Board (ARB) EMFAC2007 models correlated well with measured values. PM_2.5 EFs measured for gasoline vehicles were ~ two orders of magnitude lower than those for HDDV and did not correlate with model estimates. In the Kansas City Study, PM_2.5 EFs for gasoline-powered vehicles (e.g., passenger cars and light trucks) were generally < 0.03 g/mile and were higher in winter than summer. EMFAC2007 reported higher PM_2.5 EFs than MOBILE 6.2 during winter, but not during summer, and neither model captured the variability of the measured EFs. Total PM EFs for heavy-duty diesel military vehicles ranged from 0.18 ± 0.03 and 1.20 ± 0.12 g/kg fuel, corresponding to 0.3 and 2 g/mile, respectively. These values are comparable to those of on-road HDDV. EFs for biomass burning measured during the Fire Laboratory at Missoula Experiment (FLAME) were compared with EFs from the ARB Emission Estimation System (EES) model. The highest PM_2.5 EFs (76.8 ± 37.5 g/kg) were measured for wet (> 50% moisture content) Ponderosa Pine needles. EFs were generally < 20 g/kg when moisture content was < 20%. The EES model agreed with measured EFs for fuels with low moisture content but underestimated measured EFs for fuel with moisture content > 40%. Average EFs for dry chamise, rice straw, and dry grass were within a factor of three of values adopted by ARB in California's San Joaquin Valley (SJV). Discrepancies between measured and modeled emission factors suggest that there may be important uncertainties in current PM_2.5 emission inventories.     

Effect of gamma irradiation and frozen storage on chemical and sensory characteristics of rainbow trout (Oncorhynchus mykiss) fillet

The present study was conducted to evaluate the combined effect of low‐dose gamma irradiation (1, 3 and 5 kGy) and frozen storage (5 months at ?20 °C) on chemical and sensory characteristics of rainbow trout (Oncorhynchus mykiss) fillet. Our statistical analysis showed that irradiation process and frozen storage time had a significant effect (P < 0.05) on total volatile nitrogen (TVN), peroxide value (PV), thiobarbituric acid (TBA) and pH. The level of all of these factors increased with increasing frozen storage time. At the end of the fifth month of frozen storage, the lowest and the highest level of TVN, PV and TBA were corresponding to the irradiated samples at 3 and 5 kGy, respectively. In terms of the overall acceptability of their texture, odour, colour and taste, irradiated samples at 3 kGy had the best quality and remained acceptable after 5 months frozen storage. The optimum dose of gamma radiation of rainbow trout fillets according to chemical and sensory analysis was obtained at 3 kGy.     

Determination of production planning policies for different products in process industries: using discrete event simulation

The increasing attention to customer demands in the product process, and the inevitable features and costs of production processes have led researchers and artisans to manage orders and choose the right policy for production planning. This article identifies the structure for determining the optimal location of the Customer Order Decoupling Point (CODP) and the optimal production planning policy as one of the most important strategic decisions in the production process. So, we developed a discrete-event simulation model for realistic calculation of cost and flow time, under different scenarios, and we used the production and sales information of a dairy production plant for validation and implementation of the model. The results suggest that the use of a hybrid production planning policy reduces the cost and delivery time.     

A structure-aware algorithm for fault-tolerant scheduling of scientific workflows

The Journal of Supercomputing - Here, we propose a fault-tolerant workflow scheduling algorithm that combines basic redundancies to reduce execution time through minimizing the redundancy overhead....     

Quality changes of fish burgers prepared from deep flounder (Pseudorhombus elevatus Ogilby, 1912) with and without coating during frozen storage (−18 °C)

In the present study, chemical and sensory qualities of fish burgers prepared from deep flounder (Pseudorhombus elevatus Ogilby, 1912) with and without coating (Group A and Group B, respectively) or batter and breading materials were determined during frozen storage at ?18 °C for 5 months. According the statistical results, Total volatile base nitrogen of two groups increased significantly (P < 0.05) but a significant decrease (P < 0.05) was observed at the third month for Group A. Thiobarbituric acid value of Group A decreased significantly (P < 0.05) with the storage time from 1.01 to 0.22, whereas a significant increase (P < 0.05) was observed for Group B from 0.15 to 0.62 at the end of storage time. There were significant differences of pH in either the Group A or Group B between the beginning and end of the storage periods (P < 0.05). Parameters of colour, texture, taste and general acceptability for two groups decreased (P < 0.05) but Group B indicated better scores than Group A at the end of the storage period.     

Surface modification of poly (ethylene terephthalate) fabric by soy protein isolate hydrogel for wound dressing application

In this study, a composite of poly (ethylene terephthalate) (PET) fabric and soy protein isolate (SPI) hydrogel loaded with gabapentin was developed. For covalent attachment of SPI on the surface of PET fabric, graft polymerization of acrylic acid (AA) on the surface of PET fabric was performed and then carboxyl groups available in the structure of AA were activated using EDAC and then SPI was coated on the surface of PET fabric. The results revealed appropriate connection between hydrogel and modified fabric. The hydrogel was characterized by swelling test and the drug release behavior was investigated. It was found that the casting temperature affects the swelling ratio of the hydrogel and an appropriate release profile of the drug was observed. The surface of fabric was characterized by contact angle measurement, electron microscopy, and infrared spectroscopy. In vitro cell culture study was performed using NIH 3T3 mouse fibroblasts to investigate the biocompatibility of final composite and MTS results along with morphology of cells on the surface of PET fabric coated with SPI revealed the biocompatibility of final product and no cell cytotoxicity was observed in modified PET fabric.     

Seasonal study of aflatoxin M1 contamination in milk in five regions in Iran

Between April 2003 and February 2004, 98 samples of raw milk were obtained from milk tanks in one dairy plant in each of five regions in Iran. These were chosen with mean distances apart of 400 km, whereby they have different ecologies (temperature, relative humidity, etc.) and different agricultural products were used for animal feeding. Samples (24-25 per season) were laboratory heat treated and were analyzed for aflatoxin M1 with a validated High Performance Liquid Chromatography (HPLC) system. The overall mean of all samples was 0.041-0.065 microg/L (95% confidence) and the adjusted mean based on statistical modification was 0.039 ppb: 61 samples had 0.000-0.050 microg/L, 29 samples were contaminated with 0.05-0.10 microg/L, and the remaining 8 samples had 0.1-0.39 microg/L. All of the samples were lower than Codex Alimentarius and FDA standards (0.5 microg/L). Levels of aflatoxin M1 were higher in winter and spring than in summer and autumn, but the differences were not statistically significant (P>0.07). However, the level of aflatoxin in milk from one region (Hamedan) was significantly lower (P<0.05) than in those of the other regions (Gorgan, Rasht, Shiraz, Tehran).