A new approach for synthesis of well-crystallized Y zeolite from bentonite and rice husk ash used in Ni-Mo/Al2O3-Y hybrid nanocatalyst for hydrocracking of heavy oil

A series of Ni-Mo/Al₂O₃-Y hybrid nanocatalysts were synthesized for hydrocracking of heavy oil. The well crystallized Y zeolite was synthesized from mineral bentonite and rice husk ash by a two-step synthesis method. The solution combustion method was applied to develop a fast and simple technique for preparing of alumina-supported NiMo catalyst with high hydrodesulfurization activity. Such activity may be due to the morphological and textural modification as a consequence of the release of a high amount of exhaust gases during the combustion process. The XRD analysis revealed that the P zeolite was a competitive phase presented in the obtained product that could be eliminated using a two-step synthesis method. Compared to a one-step method, the pore volume and external surface area of the synthesized zeolite by the two-step method increased by 74 and 62%, respectively. The hydrocracking results illustrated that the synthesized zeolite was able to convert 66% of heavy oil to lighter products and reduce the viscosity up to 60%. Furthermore, the amount of sulfur removal was found to be 58%. The spent catalyst characterization suggested that the type of deposited coke was hard coke with the unsaturated aromatic ring which could be responsible for the pores blockage after the cracking reaction.     

Pair Interaction between Two Catalytically Active Colloids

Due to the intrinsically complex non-equilibrium behavior of the constituents of active matter systems, a comprehensive understanding of their collective properties is a challenge that requires systematic bottom–up characterization of the individual components and their interactions. For self-propelled particles, intrinsic complexity stems from the fact that the polar nature of the colloids necessitates that the interactions depend on positions and orientations of the particles, leading to a 2d − 1 dimensional configuration space for each particle, in d dimensions. Moreover, the interactions between such non-equilibrium colloids are generically non-reciprocal, which makes the characterization even more complex. Therefore, derivation of generic rules that enable us to predict the outcomes of individual encounters as well as the ensuing collective behavior will be an important step forward. While significant advances have been made on the theoretical front, such systematic experimental characterizations using simple artificial systems with measurable parameters are scarce. Here, two different contrasting types of colloidal microswimmers are studied, which move in opposite directions and show distinctly different interactions. To facilitate the extraction of parameters, an experimental platform is introduced in which these parameters are confined on a 1D track. Furthermore, a theoretical model for interparticle interactions near a substrate is developed, including both phoretic and hydrodynamic effects, which reproduces their behavior. For subsequent validation, the degrees of freedom are increased to 2D motion and resulting trajectories are predicted, finding remarkable agreement. These results may prove useful in characterizing the overall alignment behavior of interacting self-propelling active swimmer and may find direct applications in guiding the design of active-matter systems involving phoretic and hydrodynamic interactions.     

Automatic Seeded Region Growing (ASRG) Using Genetic Algorithm for Brain MRI Segmentation

Wireless Personal Communications - Massive multiple-input multiple-output (MIMO) technology has been proven to be a viable strategy for balancing the trade-off between energy efficiency (EE) and...     

Dynamics and vibration analysis of suspended microchannel resonators based on strain gradient theory

Microsystem Technologies - In this paper, dynamics of a suspended microchannel resonator (SMR) will be derived using the strain gradient theory. Accordingly, the size dependent governing equation...     

Regional water quality management for the Karun–Dez River basin, Iran

To achieve water quality goals in a river basin, a water quality management model (WQMM) has been developed through the geographic information system (GIS) approach and a mathematical water quality model. The developed model has been applied to the Karun and Dez Rivers, where water quality has decreased due to heavy pollutant loads from Khuzestan province cities and surrounding areas. Pollution sources, land use, geographic features and measured water quality data of the river basin were incorporated into the Arc‐View GIS database. With the database, the management model calculated management type and management cost for each management project in the river basin. Until now, river management policy for polluted rivers in Iran first penalizes pollution sources and then constructs treatment plants for the pollution sources whose wastewater is released untreated and for which the wastewater quality goal of the Iranian Department of Environment is not met. Different management projects with a time programme were proposed and they were compared with the results of the river quality without any management approach. It became clear that the results based on the management approach were much better than those for the unmanaged condition from the viewpoint of the achievement of water quality goals and cost optimization.     

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.     

Localization and quantification of drugs in animal tissues by use of desorption electrospray ionization mass spectrometry imaging

Mass spectrometric imaging (MSI) has emerged as a powerful technique to obtain spatial arrangement of individual molecular ions in animal tissues. Ambient desorption electrospray ionization (DESI) technique is uniquely suited for such imaging experiments, as it can be performed on animal tissues in their native environment without prior treatments. Although MSI has become a rapid growing technique for localization of proteins, lipids, drugs, and endogenous compounds in different tissues, quantification of imaged targets has not been explored extensively. Here we present a novel MSI approach for localization and quantification of drugs in animal thin tissue sections. DESI-MSI using an Orbitrap mass analyzer in full scan mode was performed on 6 μm coronal brain sections from rats that were administered 2.5 mg/kg clozapine. Clozapine was localized and quantified in individual brain sections 45 min postdose. External calibration curves were prepared by micropipetting standards with internal standard (IS) on top of the tissues, and average response factors were calculated for the scans in which both clozapine and IS were detected. All response factors were normalized to area units. Quantifications from DESI-MSI revealed 0.2-1.2 ng of clozapine in individual brain sections, results that were further confirmed by extraction and liquid chromatography/tandem mass spectrometry (LC/MS/MS) analysis.     

+Transient characteristics of a liquid-to-air membrane energy exchanger (LAMEE) experimental data with correlations

In this paper, the transient and steady-state performance of a liquid to air membrane energy exchanger (LAMEE) is investigated experimentally. The transient sensible, latent and total effectiveness are each presented for particular air and desiccant mass flow rate for both summer and winter supply air test conditions. After a step change in inlet conditions the effectiveness increases with time. Also, the transient effectiveness is assessed for various air and desiccant mass flow rates under summer test conditions and the LAMEE’s time constant is investigated as an important variable that depends primarily on the thermal capacity of the exchanger and liquid content. The calculated effectiveness shows considerable dependency on the air and desiccant mass flow rate. Finally, steady-state results reveal that as the desiccant mass flow rate increases or air mass flow rate decreases, the effectiveness increases.     

Performance of North American Bioreactor Landfills. II: Chemical and Biological Characteristics

The objective of this research was to examine the performance of five North American bioreactor landfills. This paper represents the second of a two-part series and addresses biological and chemical aspects of bioreactor performance including gas production and management, and leachate chemistry. The data support accelerated methane generation at several landfills (k = 0.08–0.21?1/year) relative to the AP-42 default decay rate (k = 0.04?1/year). While the data indicate that gas collection increases at bioreactor landfills, a general relationship between decay rate and moisture added or wet weight water content could not be identified. There was no indication that gas collection increases appreciably when the water content reaches 40%. Most of the leachates at the landfills in this study were commingled from cells operating as a bioreactor and conventionally. Nevertheless, trends in pH and BOD:COD in the bioreactor leachates were consistent with the impacts of enhanced biological activity. Ammonia concentrations also increased over time but remained below levels reported to be inhibitory. For both heavy metals and speciated organic chemicals, there was no indication that bioreactor landfill leachate is significantly different from leachate generated at conventional landfills.     

Investigation of indium oxide as a self-catalyst in ZnO/ZnInO heterostructure nanowires growth

We investigated the self-catalytic role of indium oxide in the growth process of ZnO/ZnInO heterostructure nanowires on Si(111). The prepared nanowires had hexagonal cross sections and were tapered with tip diameters of 90 ± 5 nm and base diameters of 230 ± 5 nm. Energy dispersive X-ray and field emission Auger spectroscopies indicated that the grown nanowires were heterostructures of ZnO and ZnInO. Analysis of the early growth process revealed that indium may play a self-catalytic role. Therefore, the vapor-liquid-solid mechanism is likely to be responsible for growth of ZnO/ZnInO nanowires. X-ray diffraction and room temperature photoluminescence (PL) data demonstrated that the presence of indium results in a decrease in nanowires' crystallinity. These wires produced a large PL emission peak in the ultraviolet (UV) region and a smaller peak in the green region of the electromagnetic spectrum. The UV peak of the ZnO/ZnInO nanowires is blue-shifted with respect to that of pure ZnO nanowires.