Experimental Study and Mathematical Modeling of NO Removal Using the UV/H2O2 Advanced Oxidation Process

An experimental study on NO removal via UV/H₂O₂ process was conducted in a semi‐continuous bubble‐column reactor and the effect of some operation parameters including NO initial concentration and gas flow rates on removal efficiency was investigated. Applying UV light increased the efficiency significantly. The steady‐state removal efficiency was found to be higher at the lower gas flow rates. The bubble size as an important factor in mass transfer calculations and modeling procedure was determined at different gas flow rates using bubble photographs and image processing technique. In the ranges of flow rates studied here, the gas flow rate had no significant effect on the bubble diameter. A mathematical model was developed to describe the NO removal process. The model predictions were compared with existing experimental data, confirming a good agreement of the data.     

The Bioactivity and Toxicological Actions of Carvacrol

Carvacrol is a monoterpenic phenol produced by an abundant number of aromatic plants, including thyme and oregano. Presently, carvacrol is used in low concentrations as a food flavoring ingredient and preservative, as well as a fragrance ingredient in cosmetic formulations. In recent years, considerable research has been undertaken in an effort to establish the biological actions of carvacrol for its potential use in clinical applications. Results from in vitro and in vivo studies show that carvacrol possess a variety of biological and pharmacological properties including antioxidant, antibacterial, antifungal, anticancer, anti-inflammatory, hepatoprotective, spasmolytic, and vasorelaxant. The focus of this review is to evaluate the existing knowledge regarding the biological, pharmacological, and toxicological effects of carvacrol.     

Developing new components for variable flow distribution system modelling in TRNSYS

This study attempts to fill the existing gap in the simulation of variable flow distribution systems through developing new pressure governing components. These components are able to capture the actual ever-changing system performance curve in variable flow distribution systems together with the prediction of controversial issues such as starving, over-flow and the lack of controllability on the flow rate of different branches in a hydronic system. The performance of the proposed components is verified using a case study under design and off-design circumstances. Full integration of the new components within the TRNSYS simulation package is another advantage of this study, which makes it more applicable for designers in both the design and commissioning of hydronic systems.     

Assessment of composite beam performance using GWO–ELM metaheuristic algorithm

Composite beams (CBs) include concrete slabs jointed to the steel parts by the shear connectors, which highly popular in modern structures such as high rise buildings and bridges. This study has investigated the structural behavior of simply supported CBs in which a concrete slab is jointed to a steel beam by headed stud shear connector. Determining the behavior of CB through empirical study except its costly process can also lead to inaccurate results. In this case, AI models as metaheuristic algorithms could be effectively used for solving difficult optimization problems, such as Genetic algorithm, Differential evolution, Firefly algorithm, Cuckoo search algorithm, etc. This research has used hybrid Extreme machine learning (ELM)–Grey wolf optimizer (GWO) to determine the general behavior of CB. Two models (ELM and GWO) and a hybrid algorithm (GWO–ELM) were developed and the results were compared through the regression parameters of determination coefficient (R²) and root mean square (RMSE). In testing phase, GWO with the RMSE value of 2.5057 and R² value of 1.2510, ELM with the RMSE value of 4.52 and R² value of 1.927, and GWO–ELM with the RMSE value of 0.9340 and R² value of 0.9504 have demonstrated that the hybrid of GWO–ELM could indicate better performance compared to solo ELM and GWO models. In this case, GWO–ELM could determine the general behavior of CB faster, more accurate and with the least error percentages, so the hybrid of GWO–ELM is more reliable model than ELM and GWO in this study.

     

The Role of Fuzzy Awareness Modelling in Cooperative Management

Cooperative management is concerned with the management of networks and services involving the cooperation of a number of human/organizational entities. One of the prerequisites for efficient management of these complex systems is related to understanding of the roles of humans and the ways hey interact with each other. Cooperative management Methodology for Enterprise Networks (CoMEN) achieves these objectives by defining an abstract measure of cooperation called Awareness level that is based on Computer Supported Cooperative Work (CSCW) concepts and techniques. In view of the abstract nature of the awareness level definitions, it is not clear how abstract awareness levels can be accurately translated into equivalent cooperative management design parameters. This paper explores the notion of fuzzy sets that enables the use of linguistic values for awareness levels. This is aimed at unveiling of the deficiencies in the existing collaborative support tools with a view to developing more effective cooperative applications. We also model the CSCW tools in terms of repositories and communication mechanisms using fuzzy notions with a view to arrive at a formal design methodology for cooperative management systems. The idea has been illustrated with a case study in a large telecom organization.     

Laminar Heat Transfer in a Pipe Subjected to a Circumferentially Varying External Heat Transfer Coefficient

Abstract

Numerical techniques have been used to solve the thermally developed regime for a laminar pipe flow that exchanges heat with a fluid environment in the presence of a circumferentially varying external heat transfer coefficient. By making use of the fact that the temperature distributions have similar shapes at successive streamwise locations, the three-dimensional temperature field was scaled to two dimensions. The resulting two-dimensional eigenvalue problem was solved by a rapidly converging automated scheme that successively refines an initial guess. Solutions were obtained for two circumferential distributions of the external heat transfer coefficient respectively intended to model forced and natural convection cross flows. The circumferential average heat transfer coefficient was found to be quite insensitive to the imposed circumferential variations. The local wall heat flux is nearly circumferentially uniform when the mean value of the external coefficient is high. On the other hand, at low mean values of the external coefficient, the local wall heat flux tends to follow the imposed circumferential variations.     

Innovative strategies for engineering mannitol production

Mannitol is an important polyol which is being used mainly in the food and pharmaceutical industries. The current techniques for the production of mannitol are reviewed. The present commercial production of d-mannitol takes place by hydrogenation reaction. The low d-mannitol yield, however, asks for the development of alternative procedures. The shortcomings and major drawbacks of commercial conventional methods and the potential prospects and incentives of new developing techniques such as supercritical and subcritical fluid extraction, and microorganism processing are discussed. Furthermore, important research obstacles and challenges in the development of an alternative technology for the mannitol production are pinpointed.     

Modification of PES/PU membrane by supercritical CO2 to enhance CO2/CH4 selectivity: Fabrication and correlation approach using RSM

Integrally skinned asymmetric gas separation membranes of polyethersulfone (PES)/polyurethane (PU) blend were prepared using supercritical CO₂ (SC-CO₂) as a nonsolvent for the polymer solution. The membrane consisted of a dense and a porous layer, which were conjoined to separate CO₂ from CH₄. The FTIR, DSC, tensile and SEM tests were performed to study and characterize the membranes. The results revealed that an increase in SC-CO₂ temperature causes an increment in permeance and a decrease in membrane selectivity. Furthermore, by raising the pressure, both permeance and selectivity increased. The modified membrane with SC-CO₂ had much higher selectivity, about 5.5 times superior to the non-modified membrane. This higher selectivity performance compared to previous works was obtained by taking the advantages of both using partial miscible blend polymer due to the strong polar–polar interaction between PU PES and SC-CO₂ to fabricate the membrane. The response surface methodology (RSM) was applied to find the relationships between several explanatory variables and CO₂ and CH₄ permeance and CO₂/CH₄ selectivity as responses. Finally, the results were validated with the experimental data, which the model results were in good agreement with the available experimental data.     

The effects of supplementation with conjugated linoleic acid on anthropometric indices and body composition in overweight and obese subjects: A systematic review and meta-analysis

Abstract

Clinical trials have indicated conflicting results on the effects of conjugated linoleic acid (CLA) on obesity. The present study aimed to systematically review controlled clinical trials examining the effects of CLA on anthropometric indices and body composition in overweight and obese subjects. Pubmed, Scopus, Web of science, and Cochrane databases were searched between 2000 and December 2017 with no language restriction. Placebo-controlled clinical trials that reported anthropometric indices and body composition in overweight and obese subjects were included. Random-effect model was used to pool the effect estimates. Of 4032 publications, 13 trials were included for the meta-analysis. Pooled effect sizes indicated that CLA significantly reduced body weight (WMD: ?0.52 kg, 95% CI: ?0.83, ?0.21; I²: 48.0%, p?=?0.01), BMI (WMD: ?0.23 kg/m², 95% CI: ?0.39,???0.06; I²: 64.7%, p?=?0.0001), FM (WMD: ?0.61 kg, 95% CI: ?0.98, ?0.24; I²: 53.8%, p?=?0.01) and increased LBM (WMD: 0.19 kg, 95% CI: 0.04, 0.34; I²: 81.4%, p?=?0.0001) compared to the placebo group. However, the effects of CLA on WC (WMD: 0.05 cm, 95% CI: ?0.01, 0.1; I²: 0%, p?=?0.93) was not significant. Additionally, its impact on body weight in subjects older than 44 year (WMD: ?1.05 kg, 95% CI: ?1.75, ?0.35; I²: 57.0%, p?=?0.01), with longer duration (more than 12 weeks) (WMD: ?1.29 kg, 95% CI: ?2.29, ?0.29; I²: 70.3%, p?=?0.003) and dosage more than 3.4 g/day (WMD: ?0.77 kg, 95% CI: ?1.28, ?0.25; I²: 62.7%, p?=?0.004) were greater than comparative groups. Supplementation with CLA can slightly reduce body weight and FM and increase LBM in overweight and obese subjects. However, its efficacy was not clinically considerable. Further studies with high methodological quality are needed to shed light on the effects of CLA on anthropometric indices in overweight and obese subjects.