The proposed study aimed to investigate the potential use of pristine multi-walled carbon nanotubes (MWCNTs) as nano reinforcement in enhancing mechanical properties of hybrid MWCNT/silica fume ...cement composites. Dispersion of MWCNTs was facilitated utilizing very fine particles of silica fume which also helped in an improved interfacial bond between MWCNTs and the cement matrix. The MWCNTs dispersion within the hardened cement matrix was qualitatively assessed by Field Emission Scanning Electron Microscope (FESEM) analysis. It was also observed that addition of MWCNTs accelerated the hydration process. The test results showed an increment in compressive strength by 12.4% and reduction in autogenous shrinkage by 8.5% for hybrid MWCNT/silica fume cement composites containing 0.01% MWCNTs (by wt. of binder). However, higher additions (greater than 0.03%) of MWCNTs appeared to have adverse effects on specimens. It was found that properly dispersed MWCNTs filled the fine pores in the cement matrix by providing an additional nucleation site for the formation of calcium silicate hydrate (C-S-H) that results in a denser microstructure, which in turn enhanced the strengths and limited the autogenous shrinkage.
Ultra-High Molecular Weight Polyethylene (UHMWPE) is used in biomedical applications due to its high wear-resistance, ductility, and biocompatibility. A great deal of research in recent decades has ...focused on further improving its mechanical and tribological performances in order to provide durable implants in patients. Several methods, including irradiation, surface modifications, and reinforcements have been employed to improve the tribological and mechanical performance of UHMWPE. The effect of these modifications on tribological and mechanical performance was discussed in this review.
The transition metal is a planar metallic organic structure, and tetra-cyano-benzene is one of the most studied networks of 3D series of transition metal. Tetra-cyano-benzene behaved as a useful ...object in the alloy synthesis industry due to its excellency of hardness. In spintronics, the tetra-cyano-benzene demonstrate a long-range ferromagnetic connection in the erection of magnetic, which is usually behaved as the ideal entrant. To study this novel tetra-cyano-benzene structure, we use an authentic mathematical tool known as vertex-edge and edge-vertex base topological indicators and shows some physical and chemical properties in numerical form, to understand the structure deeply. In this paper, we consider the formulas of the Zagreb indicator, first Zagreb alpha indicator, first Zagreb beta indicator, second Zagreb indicator, Randic indicators, Atom bond connectivity indicator, Geometric arithmetic indicator, Harmonic indicator and Sum connectivity indicator for transition metal tetra-cyano benzene (TCB(r,s)) structure based on vertex-edge and edge-vertex degree.
The present research reports on the electrical and optical properties of N-CNT doped with ZnO, which is considered as wurtzite transparent and conducting oxide semiconductor structure. The thin films ...of N-doped carbon nanotubes/ZnO were prepared using sol–gel method, then we carried out investigations in optical and electrical point of view to extract their usefulness in photovoltaic applications. For this purpose, ZnO films were doped by several ratios of carbon nanotubes and N-doped carbon nanotubes. The electrical studies were performed over these two kinds of doped ZnO films, the electrical conductivity has found to be more important for ZnO films filled with N-CNTs. This finding is pretty explained by the electronic conduction hold by nitrogen as charge carriers within carbon nanotubes.
Topological indices play a very important role in the study of structure of a chemical graph. There are many types of topological indices which describe quantitative properties of the structure of ...different graphs and molecular networks of chemical graphs. In the beginning of the study of topological indices, there were three different types of indices which were based on degree, distance and counting. M. Chellali et al. ("On Ve-Degrees and Ev-Degrees in Graphs," Discrete Mathematics 340, no. 2 (2017): 31-8) introduced V
e
- degree and E
v
- degree based topological indices. This article is a contribution to the study of V
e
-degree and E
v
-degree based topological indices for series of concealed non-Kekulean benzenoid graph. In this article, we have calculated ten different types of topological indices which are based on V
e
-degree and E
v
-degree for the series of concealed non-Kekulean benzenoid graph.
Grid implementation is a principal unit in electrical and electronic engineering but it depends on the domain of these projects. For example, depending on the grid and the signal processing in that ...fields of electronic and electrical engineering, such as more abstract mathematics in signal conversion and e-transmission theory griding, etc. Provides transmission through grid nodes. Graph theory is very useful in research fields. As topological indices, there are more actual numbers associated with chemical composition complaints connected to the chemical grid with physical and chemical properties and reactions. In this paper, we expand the work to interconnected grid and examine the first Zagreb, the second Zagreb, Randic, sum-connectivity, harmonic, geometric, and atom bond connectivity exponents of hierarchical hypercube network based on vertex-edge and edge-vertex degree.
The optical transpose interconnection system (OTIS) network has many application in architecture for parallel as well as in distributed network. The optical translate interconnection system utilizes ...a straightforward pair of lenslet clusters to execute a coordinated interconnection that is valuable for mix based multistage interconnection networks, work of-trees network processors, and hypercubes. In Cancan (2019) and Hayat et al. (2014), different interconnection network has studied related to topological indices. In this article we have computed the Ve-degree and Ev-degree base topological indices of swapped network by taking path and complete graph as original graphs. We have included some dedicated formulas for different types of topological indices for the OTIS swapped network by taking the path and complete graph on <inline-formula> <tex-math notation="LaTeX">n </tex-math></inline-formula> vertices as basis of graph.
The surface roughness is an important parameter in determining the physical properties and quality of thin films deposited by physical vapor deposition (PVD) method. The presence of an intermediate ...layer between metallic nanoparticles and substrate significantly promotes the adhesion and reduces the surface roughness. In this article, we have investigated the effect of Chromium (Cr) seed layer to optimize the surface roughness on the growth of as-deposited silver (Ag) film using borosilicate glass and silicon wafer substrates. For this purpose, Ag thin films were deposited with a Cr seed layer of different thickness on borosilicate glass and silicon wafer substrates using an electron beam (E-Beam) deposition method. The Cr thin film of different thickness ranging from 1 nm to 6 nm was thermally evaporated and pure Ag with the same thickness was evaporated at the same rate on previously coated substrates. The deposition of the nanostructured thin film was confirmed by UV-Vis and XRD characterizations. The difference in transmittance for uncoated and coated substrates ensured the deposition. The presence of pure Ag crystalline phase was confirmed by XRD pattern. Surface roughness was measured using Atomic Force Microscopy (AFM) and the conductance was measured using 4-probe conductivity method. The density of nanoparticles and smoothness were visualized from two dimensional (2D) and three dimensional (3D) surface height histograms of representative AFM images. The quantitative roughness was measured in terms of root mean square (RMS) roughness and mean roughness. The high dense and smoother thin films were found for ~2-4 nm Cr layer thickness in case of the glass substrate. The slight increase in roughness was observed for ~1-6 nm Cr layer thickness in case of the silicon substrate. The dependence of the conductivity of thin films on surface roughness is investigated to verify the effect of surface roughness on different applications of Ag thin film. The conductance results have been analyzed as; for a glass substrate, conductivity was maximum for thin films containing ~2 nm Cr seed layer thickness, while for silicon substrate the maximum conductivity was found for the thin film containing ~1 nm Cr seed layer.
African Americans are at significantly greater risk of hypertension and worse cardiovascular outcomes than other racialized groups, yet hypertension intervention effects remain limited. Thus, it is ...necessary to understand the potential mechanisms whereby interventions may be more effectively targeted to improve health. Supported by prior research evidence and guided by the Biobehavioral Family Model, this study examined associations between family relationship quality, psychological wellbeing, and self‐management behaviors for African Americans with hypertension. Data were pooled from three Midlife Development in the U.S. projects, resulting in a sample of 317 African Americans (63.4% female, Mage = 53.32) with self‐reported high blood pressure in the past 12 months. We tested four cross‐sectional multiple mediator models, with depressed mood and environmental mastery mediating associations between family strain and exercise, smoking, problematic alcohol use, and stress‐eating. Environmental mastery mediated the association between greater family strain and decreased odds of achieving recommended exercise levels; greater odds of reporting problematic alcohol use; and greater stress‐eating. Though family strain was associated with depressed mood in each model, this variable did not serve as an indirect pathway to self‐management behaviors. Family strain, and the potential pathway identified via environmental mastery, may be a meaningful predictor of disease self‐management for African Americans with hypertension. Longitudinal studies are needed to examine directionality and to support intervention trials for improving self‐management and hypertension outcomes.
摘要
与其他种族群体相比，非裔美国人患高血压和心血管疾病的风险明显更高，但高血压干预效果仍然有限。因此，有必要了解潜在的机制，从而使干预措施可以更有效地针对改善健康。在已有研究证据的支持下，在生物行为家庭模式的指导下，本研究考察了家庭关系质量、心理健康和非裔美国人高血压患者的自我管理行为之间的关联。数据来自于美国的三个中年发展项目，形成了317个非裔美国人(63.4%为女性，M年龄 = 53.32)的样本，他们在过去12个月中自我报告了高血压。我们测试了四个横断面多中介模型，其中抑郁的情绪和环境的掌握在家庭压力和运动、吸烟、问题酒精使用和压力饮食之间起中介作用。环境驾驭能力介导了更大的家庭压力与达到建议的锻炼水平的几率下降、报告有问题的酒精使用的几率增加和更大的压力饮食之间的关系。尽管在每个模型中，家庭压力都与抑郁情绪有关，但这个变量并没有成为自我管理行为的间接途径。结论。家庭压力，以及通过环境掌握确定的潜在途径，可能是非洲裔美国高血压患者疾病自我管理的一个有意义的预测因素。本文表明有必要进行纵向研究来检查方向性，并支持改善自我管理和高血压结果的干预试验。.
Contamination of edible oils with aflatoxins (AFs) is a universal issue due to the detrimental effects of aflatoxins on human health and the fact that edible oils are a major source of fungal growth, ...particularly storage fungi (Aspergillus sp.). The objective of this study was to assess aflatoxin B1 (AFB1) in edible oil used in fried food in order to determine the risk of cancer from AFB1 exposure through cooked food using the FAO/WHO’s and EFSA’s margin of exposure (MOE) quantitative liver cancer risk approaches. Using Mycosep 226 columns and HPLC-FLD, 100 samples of cooking oils (soybean, canola, and sunflower oil) from different food points were analyzed for contamination with aflatoxins. Of all the samples tested, 89% were positive for total aflatoxins and AFB1, with 65% indicating AF concentrations beyond permitted levels. Canola oil was found to contain higher levels of AFB1 and AFs than soybean and sunflower oil. Almost 71 percent of canola oil samples (range of 54.4–281.1 µg/kg) were contaminated with AF levels higher than the proposed limits of the European Union (20 µg/kg). The consumption of canola oil samples used in fried foods had MOE values that were significantly lower as compared to sunflower and soybean oils, indicating that risk reduction is feasible. Additionally, compared to soybean and sunflower oil, canola oil exhibited a greater threat of liver cancer cases linked to AFB1 exposure (17.13 per 100,000 males over 35 and 10.93 per 100,000 females over 35). Using a quantitative liver cancer approach, health risk valuation demonstrated that males and females over the age of 35 are at significant risk of developing liver cancer. The health risk assessment exposed that the males and female over the age of 35 are at considerable risk of liver cancer by using a quantitative liver cancer approach. The innovation of this study lies in the fact that no such study is reported related to liver cancer risk evaluation accompanied with AFB1 exposure from consumed edible oil. As a result, a national strategy must be developed to solve this problem so that edible oil products are subjected to severe regulatory examination.
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