A comprehensive study of two-phase flow and heat transfer of water/Ag nanofluid in an elliptical curved minichannel

In this research, laminar flow and heat transfer of two-phase water/Ag nanofluid with 0–6% volume fraction of nanoparticles at Re = 150–700 in a curved geometry are simulated using finite volume method. Studied geometry is an elliptical curved minichannel with curvature angle of 180°. Forced and natural flow of two-phase nanofluid is simulated at Gr = 15000, 35000 and 75000. For estimation of nanofluid flow behavior, two-phase mixture method is used. The second-order discretization and SIMPLEC algorithm are used for solving governing equations. The results indicate that the increase of volume fraction of nanoparticles leads to the enhancement of the temperature of central line of flow. The increase of Grashof number(Gr ～75000) has a great effect on reduction of dimensionless temperature in central line of flow. Creation of thermal boundary layer at Re = 500 and after the angle of 30° becomes significant. In low Grashof numbers(Gr ～15000), due to the great effects of temperature gradients close to wall, these regions have significant entropy generation.     

Histological,transmission electron microscopic,and immunohistochemical study of the adrenal gland in the Persian squirrel (Sciurus anomalus)

This research was aimed to present the histological and ultrastructure properties of the adrenal gland in the Persian squirrel. Two male and female animals were included in the study. The adrenal gland was bean-shaped and located on the cranial pole of kidney. The enveloping capsule was dense connective tissue that reacted positively with Periodic-Acid Schiff (PAS) and Masson trichrome stainings. The parenchyma of the gland consisted of two-part, namely cortex and medulla; the cortex had three layers: zona glomerulosa (ZG), zona fasciculata (ZF), and zona reticularis (ZR). The cells of the ZG were mainly spherical and ovoid with circular arrangement and few lipid droplets in TEM micrographs. The cells of the ZF were columnar and spherical that were arranged in cord-like rows. Transmission electron microscopy (TEM) indicated conspicuous lipid droplets and mitochondria in this zone. The cells of the ZR were arranged in a tangled networks and were almost similar to those in the ZF. TEM images showed fewer lipid vesicles in the ZR compared to the ZF and ZG. Chromaffin cells were located in the medulla of the adrenal gland in two layers. TEM images showed that some of them were smaller and contained fewer secretory granules; other cells were larger and contained more electron-dense secretory granules. Immunofluorescence staining showed that steroidogenic factor 1 (SF1) expressed from cortex to the corticomedullary junction (CMJ) and tyrosine hydroxylase (TH) expressed in the medulla. In conclusion, the results indicated both similarities and differences between the adrenal gland of the Persian squirrel and other animals such as mammals and rodents.     

Development of 3D Scanning System for Robotic Plasma Processing of Medical Products with Complex Geometries

This paper describes the development of an intelligent automated control system of a robot manipulator for plasma treatment of medical implants with complex shapes. The two-layer coatings from the Ti wire and hydroxyapatite powders are applied on the surface of Ti medical implants by microplasma spraying to increase the biocompatibility of implants. The coating process requires precise control of a number of parameters, particularly the plasma spray distance and plasma jet traverse velocity. Thus, the development of the robotic plasma surface treatment involves automated path planning. The key idea of the proposed intelligent automatic control system is the use of data of preliminary three-dimensional (3D) scanning of the processed implant by the robot manipulator. The segmentation algorithm of the point cloud from laser scanning of the surface is developed. This methodology is suitable for robotic 3D scanning systems with both non-contact laser distance sensors and video cameras, used in additive manufacturing and medicine.     

Structural,Half-Metallic,Optical, and Thermoelectric Study on the Zr2TiX (X = Al,Ga, Ge,Si) Heuslers: by DFT

Silicon - Based on the density functional theory (DFT) framework, the mechanical, half-metallic (HF), optical and thermoelectric properties of Zr2TiX (X = Al, Ga, Ge, Si) Heusler compounds are...     

Sensitivity analysis and optimization on effective parameters during chemical enhanced oil recovery (CEOR) using experimental design and numerical simulation

Several factors effect on choosing the best enhanced oil recovery process in a hydrocarbon reservoir. In the present study, effective factors on chemical enhanced oil recovery involved in polymer flooding, surfactant flooding, surfactant–polymer flooding, and alkaline–surfactant–polymer flooding are discussed in numerical simulation. The numbers of the simulation runs are estimated based on the number of factors and their maximum and minimum values using experimental design software. Oil recovery factor from reservoir simulation is considered as comparison factor in all of the run cases. The results from one parameter and two interaction factors during each flooding case were analyzed by Tornado and Parto plot. The oil recovery factor also was estimated using statistical analysis using Minitab. The results show that there is a strong correlation between simulation and statistical analysis. Furthermore, the results show that each selected factor has a different effect on oil recovery in each case of chemical flooding. The case study results on two Iranian oil fields at the end of the present study clarified that results of this study can be useful for selecting the best chemical process for oil reservoir based on reservoir properties.     

Support vector regression and neural networks analytical models for gas sensor based on molybdenum disulfide

Microsystem Technologies - In this study, MoS2 gas sensor based on field effect transistor has been proposed and the adsorption of NO2 molecules on the channel surface can lead to significant...     

The effects of caffeine intake on weight loss: a systematic review and dos-response meta-analysis of randomized controlled trials

Abstract

This systematic review and meta-analysis of randomized controlled trials (RCTs) was performed to summarize the effect of caffeine intake on weight loss. We searched the following databases until November 2017: MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials. The relevant data were extracted and assessed for quality of the studies according to the Cochrane risk of bias tool. We estimated an intake-status regression coefficient (Beta) for each primary study and estimated the overall pooled Beta and SE using random effects meta-analysis on a double-log scale. Heterogeneity between studies was assessed by the Cochran Q statistic and I-squared tests (I²). Thirteen RCTs with 606 participants were included in the meta-analyses. The overall pooled Beta for the effect of caffeine intake was 0.29 (95%CI: 0.19, 0.40; Q = 124.5, I²?=?91.2%) for weigh, 0.23 (95%CI: 0.09, 0.36; Q = 71.0, I²?=?93.0%) for BMI, and 0.36 (95% CI: 0.24, 0.48; Q = 167.36, I²?=?94.0%) for fat mass. For every doubling in caffeine intake, the mean reduction in weight, BMI, and fat mass increased 2 Beta-fold (20.29 = 1.22, 20.23 = 1.17, and 20.36 = 1.28), which corresponding to 22, 17, and 28 percent, respectively. Overall, the current meta-analysis demonstrated that caffeine intake might promote weight, BMI and body fat reduction.     

Effect of ARB Cycle Number and Second Phase Content on Mechanical properties and Microstructure of Pb–Ag Composite

A solid state method has been found for manufacturing of lead–silver composites for use as anodes in electrowinning production. Mechanical properties and microstructure of composite were characterized via peeling, tensile and microhardness tests, and scanning electron microscopy, transmission electron microscopy and fractography. Based on the peeling test results, maximum bond strength was achieved in the presence of 0.125 wt% of Ag (1.8 N/mm). Best mechanical properties were achieved in the Pb–0.5 wt% Ag composite after 10 ARB cycles by the enhanced tensile strength rising up to 50%, yield strength up to 170%, shear strength up to 63% and hardness up to 2.6 times higher, and the strain decreasing to 68% lower. These advanced properties led to higher stiffness and considerable enhancements in dimensional stability of the anodes and they improved creep characteristics. The advanced properties of the processed Pb–Ag composite anodes could be introduced as certification for slower anode failure, upkeep, surcharge and capital expenditure of industries with essential lead anode requirement.     

Solubility and thermodynamics of lamotrigine in carbitol + water mixtures from T = (293.2 to 313.2) K

The solubility of lamotrigine (LTG) are measured in aqueous mixtures of carbitol at temperatures ranging from 293.2 to 313.2 K. LTG solubility increases with increasing mass fraction of carbitol, and maximum solubility is observed in neat carbitol. Four cosolvency mathematical models; i.e., Yalkowsky model, Jouyban–Acree model, Jouyban–Acree–van’t Hoff model and modified Wilson model are fitted to the experimental results, and back-calculation is performed by using the solubility data in monosolvents in which the mean relative deviation of the investigated models are 64.8%, 9.0%, 7.2%, and 46.7%, respectively. Furthermore, the apparent thermodynamic properties of the dissolution process are computed according to van’t Hoff and Gibbs equations. The preferential solvation is analyzed based on the inverse Kirkwood-Buff integrals by using the solubility values at 298.2 K. LTG is preferentially solvated by water in water-rich mixtures (0.00?<?x₁?<?0.12) and by carbitol in mixtures with solvent composition of 0.12?<?x₁?<?1.00.