FLOW STRESS DATA FOR FINITE ELEMENT SIMULATION IN METAL CUTTING: A PROGRESS REPORT ON MADAMS

To obtain reliable results from Finite Element (FE) simulation of machining processes, it is necessary to have as input the properties of the workpiece and tool materials as well as the characteristics of the tool/chip interface. These input parameters include physical and thermal data, friction and heat transfer, and most importantly the flow stress of the workpiece material under high strain, strain rate and temperature conditions that exist during the process. This paper presents a brief review of FE simulation of machining processes, a review of the approaches used to determine the flow stress at high deformation rate, and the examples of different constitutive equations used to represent such flow stress data. A material property database (MADAMS) has been developed and provides useful information to conduct simulations of machining processes. The main objectives of the material database are to assist researchers in areas of machining analysis and material modeling and to promote collaboration between various international research groups.     

Recent developments in catalyst synthesis using DBD plasma for reforming applications

The catalyst has a significant role in gas processing applications such as reforming technologies for H₂ and syngas production. The stable catalyst is requisite for any industrial catalysis application to make it commercially viable. Several methods are employed to synthesize the catalysts. However, there is still a challenge to achieve a controlled morphology and pure catalyst which majorly influences the catalytic activity in reforming applications. The conventional methods are expansive, and the removal of the impurities are major challenges. Nevertheless, it is not straightforward to achieve the desired structure and stability. Therefore, significant interest has been developed on the advanced techniques to take control of the physicochemical properties of the catalyst through non-thermal plasma (NTP) techniques. In this review, the systematic evolution of the catalyst synthesis using NTP technique is elucidated. The emerging DBD plasma to synthesized and effective surface treatment is reviewed. DBD plasma synthesized catalyst performance in reforming application for H₂ and syngas production is summarised. Furthermore, the status of DBD plasma for catalyst synthesis and proposed future avenues to design environmentally suitable and cost-effective synthesis techniques are discussed.     

Effect of Bicarbonate Salts and Sequential Using of Frying Oil on Acrylamide and 5-Hydroxymethylfurfural Contents in Coated Fried Chicken Meat

In this research, the effect of different bicarbonate salts (sodium and ammonium) and their doses (0, 1, 2, and 3 g/100 g raw material) in the coating batter formula use and the sequential use of frying oil (1st, 2nd, 3rd, and 4th) on 5-hydroxymethylfurfural and acrylamide contents in coated fried chicken meat. The addition of sodium bicarbonate was efficient for reducing acrylamide content, but it increased browning and 5-hydroxymethylfurfural content compared to the control. When increasing the doses of sodium and ammonium bicarbonate from 1 to 3 g/100 g of raw material, the acrylamide content of samples did not change significantly, although adding sodium bicarbonate significantly reduced the acrylamide content as a control. These research results showed that using about 1 g/100 g raw material sodium bicarbonate rather than ammonium bicarbonate and as little frying oil as possible use during the production of coated and fried meat results in lower contents of 5-hydroxymethylfurfural and acrylamide.     

The use of basalt powder as a natural heterogeneous catalyst in the Fenton and Photo-Fenton oxidation of cationic dyes

The use of naturally present heterogeneous catalysts has recently been an essential issue in the Fenton and photo-Fenton processes. In this study, the uses of basalt as a catalyst for the Fenton and photo-Fenton reactions for methylene Blue (MB) and Basic Red 18 (BR18) degradations were investigated. Basalt was selected because of the presence of the iron (III) oxide in the structure. Basalt was characterized by X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD) analysis to obtain the chemical composition and the crystalline phase. The surface charge and the surface area were obtained by zeta potential and Brunauer Emmett-Teller (BET) analysis. Fourier Transform Infrared Spectroscopy (FTIR) and scanning electron microscope (SEM) were utilized to explore the functional group and the surface morphology. Fenton and photo-Fenton processes were applied to explore the best degradation method. Adsorption was also tested and the adsorption process had minimum removal efficiency (12% for MB and 17% for BR18). The removal efficiencies for MB and BR18 by the Fenton process were 87% and 28%, respectively. The photo-Fenton process had maximum removal efficiency with 100% for MB and 70% for BR18. The optimum conditions were 70 mg/L dye concentration, 5 mM H₂O₂, 1.0 g/L basalt loading and pH 2. Basalt has shown reuse capability as a catalyst for three consecutive cycles.     

Forecasting hydrogen production potential in islamabad from solar energy using water electrolysis

The focus of this study is the use of Machine Learning methods to forecast Solar Hydrogen production potential for the Islamabad region of Pakistan. For this purpose, we chose a Photovoltaic-Electrolytic (PV-E) system to forecast electricity and, hence, hydrogen production. The weather data used for forecasting and simulation were recorded with precise meteorological instruments stationed in Islamabad, over the course of 13 and a half months. Out of the three tested algorithms, Prophet performs the best with Mean Absolute Percentage Error of 3.7%, forecasting a daily average Hydrogen production of 93.3 × 10³ kg/Km². Although, the forecast in this study is made for the month of August and September, during which the local season moves towards winter, this study demonstrates solar hydrogen production, as a green energy source, has a tremendous potential in this region.     

A new acylated and oleanane-type triterpenoid saponin from Gypsophila arrostii roots

A new acylated and triterpenoidal saponin, named GS1, was isolated from the roots of Gypsophila arrostii Guss. On the basis of acid hydrolysis, comprehensive spectroscopic analyses and comparison with spectral data of known compounds, its structure was established as 3-O-β-D-xylopyranosyl-(1→2)-[β-D-xylopyranosyl-(1→3)]-β-D-glucopyranosyl-{21-O-[(E)-3,4,5trimethoxycinnamoyl]}21-hydroxygypsogenin 28-O-β-D-glucopyranosyl-(1→2)- [β-D-arabinopyranosyl-(1→3)]-β-D-xylopyranosyl-(1→3]-α-L-rhamnopyranosyl ester. This article deals with the isolation and structural elucidation of new acylated and oleanane-type saponin.     

Fracture load and microcrack comparison of crowns manufactured from tooth‐shaped and traditional blocks

This study intended to analyze microcracks and fractographic markings on the surface of all ceramic crowns after milling and compare the fracture loads. 90 crowns were manufactured from two feldspathic (Priticrown‐Pr and Vita Mark II‐Vi) and a lithium disilicate (EmaxCAD‐Em) blocks (n = 30). Two groups (n = 15) were prepared for each ceramic. In the first group, crowns were analyzed twice via the fluorescent penetrant method for microcrack detection, after the manufacturing process and thermal cycles. The load to fracture test was applied at a crosshead speed of 0.5 mm/min until catastrophic failure. Second group crowns were directly cemented onto the Co‐Cr dies following the manufacturing process and loaded to fracture. Fractographic markings were analyzed through scanning electron microscope. Spearman correlation analysis, Kruskal–Wallis H test, Mann–Whitney U test, and Wilcoxon Signed Rank test were applied (α = .05). Fracture loads of Em crowns were higher than other groups (p < .05), with and without the aging procedure. Except for second group Pr (r = ?.532), no significant relationship was found between microcrack numbers and fracture loads (p > .05). Thermal cycling did not affect microcrack numbers and fracture loads (p > .05). Tooth‐shaped multilayered Pr blocks did not provide an advantage in terms of microcrack and fracture loads.