Hydrogen production by sorption-enhanced steam reforming of glycerol

Catalytic steam reforming of glycerol for H(2) production has been evaluated experimentally in a continuous flow fixed-bed reactor. The experiments were carried out under atmospheric pressure within a temperature range of 400-700 degrees C. A commercial Ni-based catalyst and a dolomite sorbent were used for the steam reforming reactions and in situ CO(2) removal. The product gases were measured by on-line gas analysers. The results show that H(2) productivity is greatly increased with increasing temperature and the formation of methane by-product becomes negligible above 500 degrees C. The results suggest an optimal temperature of approximately 500 degrees C for the glycerol steam reforming with in situ CO(2) removal using calcined dolomite as the sorbent, at which the CO(2) breakthrough time is longest and the H(2) purity is highest. The shrinking core model and the 1D-diffusion model describe well the CO(2) removal under the conditions of this work

Analysis of milling of dry compacted ribbons by distinct element method

Fine cohesive powders are often dry granulated to improve their flowability. Roller compaction is commonly used to produce dense ribbons which are then milled. The material properties of the powder and the conditions in the roller compactor affect the strength of the ribbons, however there is no method in the literature to predict the size distribution of the product of ribbon milling. Here we introduce a method, by using the Distinct Element Method (DEM) to determine the prevailing impact velocities and stresses in the mill, with bonded spheres representing the ribbons. The bond strength is calibrated by matching experimental results of three point bend measurements and predictions from numerical simulations. The ribbons are then exposed to the dynamic conditions predicted by the DEM, by dropping them from a controlled height to cause fragmentation, and subsequently stressing them in a shear cell under the conditions again predicted by the DEM. The fragments are sheared under these conditions to represent repeated passage of bars over the fragments at the mill base. Sieve analysis is used here to determine the particle size distribution under given mill conditions. The predicted size distribution of the mill product compares well with the plant data. It is found that the mill speed and length of ribbons fed to the mill have no significant influence on the product size distribution for the range tested

Efficiency of multi walled carbon nanotubes for removing Direct Blue 71 from aqueous solutions

Dye wastewater produced from industrial activity is usually toxic, resistant to biodegradation and persistent in the environment. The aim of this study was to evaluate the efficiency of multiwalled carbon nanotubes (MWCNTs) for decolorization of Direct Blue 71 (DB71). In this experimental study, the effect of various variables including contact time, solution pH, adsorbent dose, and initial dye concentration was evaluated in a batch reactor. The adsorption and kinetic models were evaluated to explain the adsorbed dye and dynamic reaction. The results of this study showed that the efficiency of dye removal increased, as the contact time and adsorbent dose increased, but as pH and initial dye concentration increased, removal efficiency decreased. The maximum efficiency of Direct Blue 71 removal was observed at acidic solution (pH=3), contact time of 90 minutes, adsorbent dose of 0.6 g/l and initial dye concentration of 25 mg/l. The adsorption of direct blue 71 best fitted the Langmuir isotherm (R2=0.87) and pseudo first order kinetic equation (R2=0.99). According to the results obtained, multiwalled nanotubes was offered as an effective adsorbent for removing direct blue 71. © Authors

Staphylococcus aureus Isolates Carrying Panton-Valentine Leucocidin Genes: Their Frequency, Antimicrobial Patterns, and Association With Infectious Disease in Shahrekord City, Southwest Iran

Background: A diversity of virulence factors work together to create the pathogenicity of Staphylococcus aureus. These factors include cell surface components that promote adherence to surfaces as well as exoproteins such as Panton-Valentine leukocidin (PVL), encoded by the luk-PV genes, that invade or bypass the immune system and are toxic to the host, thereby enhancing the severity of infections caused by methicillin-resistant Staphylococcus aureus (MRSA). Objectives: The aim of this study was to determine the frequency of PVL-positive MRSA strains by real-time PCR and their antibiotic susceptibility patterns by phenotypic test. Materials and Methods: In total, 284 Staphylococcus isolates, identified by phenotypic methods from clinical samples of Shahrekord University Hospitals, Shahrekord, Iran, were tested for nuc, mecA, and PVL genes by TaqMan real-time PCR. The antibiotic susceptibility patterns of PVL-containing MRSA strains were determined via the disk diffusion method. Results: In total, 196 isolates (69%) were nuc positive (i.e., S. aureus); of those isolates, 96 (49%) were mecA positive (MRSA). Eighteen (18.8%) of the 96 MRSA positive and 3 (3%) of the 100 methicillin-susceptible Staphylococcus aureus (MSSA) strains were PVL positive. PVL-positive MRSA strains were mostly recovered from tracheal specimens. Eight PVL-positive MRSA strains were resistant to all the tested antibiotics except vancomycin. A significant correlation (P = 0.001) was found between the mecA positivity and the presence of luk-PV genes. Conclusions: Community acquired (CA)-MRSA is becoming a public health concern in many parts of the world, including Asian countries. The variable prevalence of luk-PV-positive MRSA isolates in different regions and their rather high frequency in pneumonia necessitate the application of rapid diagnostic methods such as real-time PCR to improve treatment effectiveness

Step by step towards citizen science — deconstructing youth participation in BioBlitzes

BioBlitzes, typically one-day citizen science (CS) events, provide opportunities for the public to participate in data collection for research and conservation, potentially promoting deeper engagement with science. We observed 81 youth at 15 BioBlitzes in the U.S. and U.K., identifying five steps participants use to create a biological record (Exploring, Observing, Identifying, Documenting and Recording). We found 67 youth engaged in at least one of the steps, but seldom in all, with rare participation in Recording which is crucial for contributing data to CS. These findings suggest BioBlitzes should reduce barriers to Recording for youth to increase engagement with science

Efficiency of multi walled carbon nanotubes for removing Direct Blue 71 from aqueous solutions

Dye wastewater produced from industrial activity is usually toxic, resistant to biodegradation and persistent in the environment. The aim of this study was to evaluate the efficiency of multiwalled carbon nanotubes (MWCNTs) for decolorization of Direct Blue 71 (DB71). In this experimental study, the effect of various variables including contact time, solution pH, adsorbent dose, and initial dye concentration was evaluated in a batch reactor. The adsorption and kinetic models were evaluated to explain the adsorbed dye and dynamic reaction. The results of this study showed that the efficiency of dye removal increased, as the contact time and adsorbent dose increased, but as pH and initial dye concentration increased, removal efficiency decreased. The maximum efficiency of Direct Blue 71 removal was observed at acidic solution (pH=3), contact time of 90 minutes, adsorbent dose of 0.6 g/l and initial dye concentration of 25 mg/l. The adsorption of direct blue 71 best fitted the Langmuir isotherm (R2=0.87) and pseudo first order kinetic equation (R2=0.99). According to the results obtained, multiwalled nanotubes was offered as an effective adsorbent for removing direct blue 71. © Authors

Association of P1635 and P1655 polymorphisms in dysbindin (DTNBP1) gene with schizophrenia

Alizadeh F, Tabatabaiefar MA, Ghadiri M, Yekaninejad MS, Jalilian N, Noori-Daloii MR. Association of P1635 and P1655 polymorphisms in dysbindin (DTNBP1) gene with schizophrenia. Objectives: Schizophrenia (SCZ) is a severe psychiatric disorder with a lifetime prevalence of approximately 1 in most of the populations studied. SCZ is multifactorial with the contribution of multiple susceptibility genes that could act in conjunction with epigenetic processes and environmental factors. There is some evidence supporting the association between genetic variants in dysbindin (DTNBP1) gene and SCZ in populations. In this study, we investigated the association between polymorphisms P1635 and P1655 in dysbindin gene with SCZ. Methods: Totally, 115 unrelated patients with SCZ and 117 unrelated healthy volunteers were studied. Genomic DNA was extracted from blood. Genotyping was done with the PCR-RFLP method. The allele and genotype associations were analysed with �2 test. The Benjamini-Hochberg procedure was used to correct p values for multiple comparisons. Results: The results showed no significant difference between patients and controls in allelic frequencies or genotypic distributions of SNP P1635 (p = 0.809), but a significant difference between the case and control groups for SNP P1655 (p = 0.009) was found. We could also find a significant positive association between A-C haplotype and SCZ (OR = 1.7, 95 CI 1.18-2.42; p = 0.004, pc = 0.02) and a protective effect for A-G haplotype (p = 0.003, OR = 0.57, 95 CI 1.18-2.42; p = 0.003, pc = 0.02). Conclusion: This study may provide further support for the association between SNP polymorphisms in DTNBP1 and SCZ in the Iranian population. Studies with more markers and subjects for various populations will be necessary to understand the genetic contribution of the gene to the development of SCZ. © 2011 John Wiley & Sons A/S

Optimization of electro-kinetic process for remediation of soil contaminated with phenanthrene using response surface methodology

The objective of this work was to investigate the modification of soil contaminated with phenanthrene (PHE) by electro-kinetic remediation (EKR) process using response surface methodology (RSM). The soil sample was obtained from the subgrades (0–30 cm) of an area close to Shahroud City, Northeast of Iran. The effect of variables such as initial pH, voltage, electrolyte concentration, and reaction time on PHE removal was studied. Based on the results obtained from the central composite design (CCD) experiment, the highest and lowest amount of PHE removal was 97 and 20%, respectively. In this study, the variables A, B, C, AB, AC, and C2 with a p value < 0.05 were significant model terms and the parameter of the lack of fit was not significant (p value = 0.0745). Findings indicated that the “predicted R-squared” of 0.9670 was in reasonable agreement with the “adj R-squared” of 0.9857 and the plot of residual followed a normal distribution and approximately linear. Also, the kinetic rates of the removal PHE by the EKR process best fitted with a first-order kinetic model (R2: 0.926). Results of the investigation of the effective variables showed that in values of pH 3, time of 168 h, voltage of 3 V, and electrolyte concentration of 4 mg/L, the removal efficiency of PHE reached 96.6%. [Figure not available: see fulltext.

Young people in iNaturalist: a blended learning framework for biodiversity monitoring

Participation in authentic research in the field and online through Community and Citizen Science (CCS) has shown to bring learning benefits to volunteers. In online CCS, available platforms present distinct features, ranging from scaffolding the process of data collection, to supporting data analysis and enabling volunteers to initiate their own studies. What is yet not well understood is how best to design CCS programmes that are educational, inclusive, and accessible by diverse volunteers, including young people and those with limited prior science experiences who are rather few in CCS. In this study, we interviewed 31 young people, aged 7–20 years old, who used iNaturalist, an online biodiversity monitoring platform, and identified how different forms of participation online and in the field facilitated (or inhibited) certain forms of learning, as defined by the Environmental Science Agency framework. Findings revealed that iNaturalist enabled participation of young people including those with limited science experiences and facilitated science learning such as the development of science competence and understanding. A blended learning framework for biodiversity monitoring in CCS is presented as a means to support the development of hybrid, educational, and inclusive CCS programmes for young people