THE PERFORMANCE OF LOW COST CUTTING TOOLS WHEN MACHINING HARDENED STEEL OF 60 HRC

Hard turning is a topic of great interest in today’s industrial production and scientific research. The hard turning technology has the potential for improving productivity against grinding in the manufacturing process. Today, tool manufacturers are constantly developing new combinations of coatings and substrates to precisely match different workpiece materials and operations. Nevertheless, the suitability of coated mixed ceramic (AI2O3 + TiCN) cutting tools when hard turning AISI D2 cold work tool steel (60 HRC) is yet to be investigated. An understanding of the tool life and wear mechanisms, surface integrity produced by coated mixed ceramic cutting tools will give an alternative to the manufacturing industries to exploit low costs cutting tools in hard turning of AISI D2 (60 HRC). The noticeable trend of the tool life was observed at test conditions where the cutting speed is at 100 m/min instead of 140 m/min or 200 m/min. The wear mechanism of coated mixed ceramic cutting tools with TiN is subjected to abrasion, adhesion, chipping and notching, especially when machining at high cutting speed of 200 m/min

Collapsibility of PMMA Based Material in Direct Investment Casting

Over recent years, the rapid growth of Additive manufacturing (AM) has benefits the Direct Investment Casting (DIC) process for intricate design in which significantly reduces the cost when associated with low volume production. Nevertheless, ceramic shells cracking has been recognized as critical problem when involved direct casting in which leads to incomplete collapsibility. Therefore, this study presents a numerical and experimental on poly(methyl) methacrylate (PMMA) pattern collapsibility for investment casting process and the stress analysis study on the ceramic shells. Study revealed that there were significant average of 5.8 % reduction of stress between square and polygon patterns. This study was conducted to examine the collapsibility of AM materials in the IC process

Collapsibility of PMMA Based Material in Direct Investment Casting

Over recent years, the rapid growth of Additive manufacturing (AM) has benefits the Direct Investment Casting (DIC) process for intricate design in which significantly reduces the cost when associated with low volume production. Nevertheless, ceramic shells cracking has been recognized as critical problem when involved direct casting in which leads to incomplete collapsibility. Therefore, this study presents a numerical and experimental on poly(methyl) methacrylate (PMMA) pattern collapsibility for investment casting process and the stress analysis study on the ceramic shells. Study revealed that there were significant average of 5.8 % reduction of stress between square and polygon patterns. This study was conducted to examine the collapsibility of AM materials in the IC process

Drug supply shortage in Nigeria during COVID-19: efforts and challenges

The COVID-19 pandemic has resulted in massive disruptions in global supply chains. Nigeria is particularly vulnerable with respect to pharmaceuticals since there is reduced local production and about 70% of the drug supply is imported creating a huge supply–demand disparity particularly in times like COVID-19. Nigeria is in need of huge quantities of quality-assured health commodities to effectively respond to the pandemic. Significant shortages of other essential medicines and medical products across the country could be imminent. Drug scarcity in Nigeria during the COVID-19 pandemic period is because of several accumulated factors, majorly as a result of global lockdown, decreased manufacturing, unaddressed regulatory affairs, poor access to resources by the population, lack of buffer stocks, security instability, and poor funding of the healthcare system. This situation if left unattended, could cause serious drawbacks to the health of the populace as well as the quality of life of Nigerians amid the COVID-19 Pandemic. Appropriate measures should be directed to ensure ethical processes on drug production, importation, pricing, and distribution to avoid such events during unavoidable scenarios, like the COVID-19 pandemic and other public health emergencies

Ternary glycerol-based deep eutectic solvents: physicochemical properties and enzymatic activity

The present study investigates deep eutectic solvents (DESs) as potential media for enzymatic hydrolysis. A series of ternary ammonium and phosphonium-based DESs were prepared at different molar ratios by mixing with aqueous glycerol (85%). The physicochemical properties including surface tension, conductivity, density, and viscosity were measured at a temperature range of 298.15 K – 363.15 K. The eutectic points were highly influenced by the variation of temperature. The eutectic point of the choline chloride: glycerol: water (ratio of 1: 2.55: 2.28) and methyl triphenylphosphonium bromide:glycerol: water (ratio of 1: 4.25:3.75) is 213.4 K and 255.8 K, respectively. The stability of the lipase enzyme isolated from the porcine pancreas (PPL) and Rhizopus niveus (RNL) toward hydrolysis in ternary DESs medium was investigated. The PPL showed higher activity compared to the RNL in DESs. Molecular docking simulation of the selected DES with the substrate (p-nitrophenyl palmitate) towardPPL was also reported. It is worth noting that ternary DES systems would be viable lipaseactivators in hydrolysis reactions

Étude sur l'affectation des ressources à la recherche agricole en Malaisie

Réunion: Resource Allocation to Agricultural Research, 8-10 June 1981, Singapore, SGDans IDL-648

Agricultural research system in Malaysia : a study of resource allocation

Meeting: Resource Allocation to Agricultural Research, 8-10 June 1981, Singapore, SGIn IDL-448

Sistema de investigación agrícola en Malasia : un estudio de la asignación de recursos

Reunión: Asignación de Recursos para la Investigación Agrícola, 8-10 jun. 1981, Singapore, SGEn IDL-239