Green synthesis of ZnO and ZnO/CuO nanocomposites in <Emphasis Type="Italic">Mentha longifolia</Emphasis> leaf extract: characterization and their application as anti-bacterial agents

In this work, we fabricated ZnO and ZnO/CuO nanocomposites using Mentha longifolia leaf extract as a natural, non-toxic, and efficient stabilizer. Anti-bacterial activities of the prepared samples against two pathogenic bacteria, Escherichia coli (Gram-negative), and Staphylococcus aureus (Gram-positive) were investigated. The properties of the as-prepared samples were characterized by XRD, EDX, SEM, TEM, TGA, FT-IR, UV–Vis DRS, and BET instruments. The XRD analysis indicated that the size of crystallites was decreased for the ZnO powder prepared in the presence of the leaf extract. The SEM images showed that the samples consist of spherical shaped well-distributed particles. In addition, the presence of biomolecules from the leaf extract was revealed by EDX, TGA, FT-IR, and UV–Vis DRS analyses, which are important in biosynthesis process. The highest anti-bacterial activity belonged to the ZnO/CuO (10%) nanocomposite and the other compounds, including ZnO/CuO (5%), ZnO (ext), and ZnO (W) were in the next ranks, respectively. It was observed that the viability percentages against E. coli (10.16?±?2.2) is higher than that of S. aureus (17.1?±?0.87) in the presence of the ZnO/CuO (10%) nanocomposite. Ultimately, the mechanism for the action of the ZnO/CuO (10%) nanocomposite was explored through the SEM images, which involved the disruption of the bacterial membranes.     

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.     

Reactive DC magnetron sputter deposited copper nitride nano-crystalline thin films: Growth and characterization

CuN_x thin films were grown by reactive DC magnetron sputtering and their structural, morphological, optical and electrical properties were evaluated. This study provides insight into the importance of substrate temperature and nitrogen content on the characteristic of CuN_x films. Phase analysis and structural properties of these films were identified by X-ray diffraction (XRD) technique. XRD results showed that the CuN_x films were single phase and polycrystalline with mixed orientation. Nitrogen excess accommodates in vacant interstitial sites of cubic anti-ReO₃ crystal structure of CuN_x and exhibits a solid solubility. The variation of surface morphology, studied by scanning electron microscope (SEM), shows suppression of the pyramidal-like grain growth by N richness. Optical study were performed by UV-Vis-near IR transmittance spectroscopy. Film thickness, refractive index and extinction coefficient were extracted from the measured transmittance using a reversed engineering method. Absorption coefficient and electrical resistivity indicate that the CuN_x films present extrinsic semiconducting behavior with an indirect optical band gap between 1.19 and 1.44 eV. To confirm the optical band gap energy, a first principle calculation was performed and compared with the measured data.