Synthesis of Ti-6Al-4V alloy with nano-TiN microstructure via spark plasma sintering technique

Abstract: The effect of nano-TiN dispersion strengthened Ti-6Al-4V via spark plasma sintering method has been investigated. Ti-6Al-4V with 4 vol. percent of nano-TiN were mixed in a Turbula shaker mixer for 8 h at a speed of 49 rpm and the admixed powders were sintered at sintering temperature range of 1000 - 1100 oC, holding time of 10-30 mins, heating rate of 100 oC/min under an applied pressure of 50 MPa. The morphology of the as-received and sintered compacts was examined by scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS) and phase analysis was done by X-ray diffractometry (XRD). The sintered compacts without nano-TiN reveal lamellar structure while reinforced Ti- 6Al-4V with nano-TiN shows a bimodal structure and titanium nitride has a great influence on α grain growth at high temperature. Furthermore, the microstructural formation mechanism was investigated. With the addition of the content of Ti-6Al-4V with 4 vol.% of nano-TiN, the microhardness also improved and this was due to homogenous distribution of TiN in Ti-6Al-4V matrix

Influence of sintering temperature on hardness and wear properties of TiN Nano reinforced SAF 2205

Abstract: Conventional duplex stainless steel degrade in wear and mechanical properties at high temperature. Attempts have been made by researchers to solve this problems leading to the dispersion of second phase particles into duplex matrix. Powder metallurgy methods have been used to fabricate dispersion strengthened steels with a challenge of obtaining fully dense composite and grain growth. This could be resolved by appropriate selection of sintering parameters especially temperature. In this research, spark plasma sintering was utilized to fabricate nanostructured duplex stainless steel grade SAF 2205 with 5 wt.% nano TiN addition at different temperatures ranging from 1000 °C to 1200 °C. The effect of sintering temperature on the microstructure, density, hardness and wear of the samples was investigated. The results showed that the densities and grain sizes of the sintered nanocomposites increased with increasing the sintering temperature. The microstructures reveal ferrite and austenite grains with fine precipitates within the ferrite grains. The study of the hardness and wear behaviors, of the samples indicated that the optimum properties were obtained for the sintering temperature of 1150 °C

The practice of hepatocellular cancer surveillance in Nigeria

Background: Hepatocellular cancer is a disease of global and public health importance due to the widespread distribution of risk factors and associated high case fatality. Hepatocellular Cancer (HCC) in Sub-Saharan Africa is commonly seen among the younger age groups (<45 years) who present mostly in the terminal stage, when the disease is not amenable to any curative therapy. Hepatocellular Carcinoma surveillance employs the use of simple, cheap and readily available investigations, to detect early curable cancer in individuals with risk factors for HCC.Objectives:The aim of this study is to assess the practice of hepatocellular cancer screening among physicians.Methodolgy:This is a nationwide online survey carried out among physicians who care for patients with HCC. A questionnaire was sent out via a web link to all consenting doctors in Nigeria. The responses were collated in a cloud-based application and data was analysed using Epi-info version 20.Results:Atotal of 218 respondents, 142 were males (65.1 %) with a mean age of 37.6 ± 5.7 years. The modal age group was 31-40 years 153 (69.5%). The main factors considered as a hindrance to surveillance were; the cost of the tests (57.7%), failure of return of patients (50.5%) and not being aware of a surveillance program (45.2 %). The majority of the respondents were Gastroenterologists and Family Physicians. 54% of the gastroenterologists and 64% of the family physicians have never offered HCC surveillance to their patients.Conclusion:This survey highlights a knowledge gap in HCC surveillance among physicians. There is a need to make HCCsurveillance a daily routine among patients at risk by all physicians. Keywords: Surveillance, Hepatocellular Carcinoma, HBV, HCV, Cancer screening

Dry season juvenile growth and physiological parameters in exotic and nigerian indigenous chicken

This study evaluated early growth and plasma hormonal profile in exotic strains of broiler and Nigerian indigenous chicken. A total of 1200 hatching eggs, 300 each from four strains of chicken were used for this study. The strains included the Nigerian indigenous chicken (NIC), the Arbor acre, Hubbard, and Marshall broiler strains. Chicks weights were monitored weekly. Blood samples were collected at hatch (day-old), weeks 1, 2, 3 and 4 post-hatch for triiodothyronine (T 3 ) and corticosterone level determination. The chicks were randomly distributed into four rearing pens for a 28-d assessment of growth rate. Results showed that the body weights (g) in the broiler strains were higher than that of the NIC throughout the rearing period. There was no significant difference (p>0.05) in the levels of T 3 at day-old and at week 1 until later in the growth phase. Corticosterone levels did not differ significantly at day-old but became different from week 1 post-hatch. The levels of T 3 were not statistically different in the first week of growth. In the second week of post-hatch growth, there was a statistical difference in the levels of T 3 among the four strains of chicken. The level in the NIC was comparable (p<0.05) to those of Arbor acre and Marshall strains. The level in the Hubbard was significantly lower than that of the NIC, Arbor acre and Marshall. In the third week of growth, the level in the NIC was similar to that of Marshall strain and higher than those of Hubbard and Arbor acre strains. This study showed that at hatching, there was no difference (p>0.05) in the metabolic rate and the stress level among the strains of chicken as shown by the levels of T 3 and corticosterone respectively. The day-old chick weight and the weights in subsequent weeks post-hatch were smaller in the NIC than the broiler strains possibly as a result of low hatching weight. The early growth difference could not be explained by physiological parameters such as T 3 and corticosterone. However, the differences in post- hatch physiological and metabolic parameters may be due partly to genetic differences.En este estudio se evaluó el crecimiento juvenil y perfil de hormonas plasmáticas en cepas exó- ticas de broilers y pollos nigerianos, empleando un total de 1200 huevos eclosionados, 300 de cada una de las cuatro líneas estudiadas. Las líneas estudiadas fueron Pollo Indígena Nigeriano (NIC) y las líneas Arbor Acre, Hubbard y Marshall. Se- manalmente se controló el peso y se tomaron muestras de sangre a la eclosión (1 día) y sema- nas 1, 2, 3 y 4 de vida para la determinación de triyodotironina (T3) y corticosterona. Los pollos fueron distribuidos al azar en cuatro jaulas de cría para evaluación del crecimiento en 28 días. Los resultados mostraron que el peso en las líneas de broilers fueron mayores que en los pollos NIC en todo el periodo. No hubo diferencias significativas en los niveles de T3 a 1 día de edad y semana 1 hasta el final de la fase de crecimiento. Los niveles de corticosterona no variaron en el día 1, pero se hicieron diferentes desde la semana 1. Los niveles de T3 no fueron diferentes en la primera semana de crecimiento. En la segunda semana de creci- miento hubo diferencias entre las cuatro líneas estudiadas. El nivel en NIC fue conmparable al de las líneas Arbor Acre y Marshall. El nivel en la línea Hubbard fue inferior al de NIC, Arbor Acre y Marshall. En la tercera semana de crecimiento, el nivel en NIC fue similar al de Marshall y superior al de Hubbard y Arbor Acre. El estudio demostró que a la eclosión, no hubo diferencias en la tasa metabólica y nivel de estrés entre las cepas estudiadas como se comprueba por los niveles de T3 y corticosterona respectivamente. El peso de los pollos de un día y el peso en las siguientes semanas fueron más bajos en los pollos NIC. Sin embargo, las diferencias en los parámetros fisio- lógicos y metabólicos en el crecimiento juvenil, pueden ser parcialmente debidas a las diferencias genéticas

APPLICATION OF PROFITABILITY CONCEPT: A CASE IN THE PLASTIC RECYCLING INDUSTRY

&lt;p&gt;ENGLISH ABSTRACT:In this article the principles of industrial engineering are applied to maximize the profitability of the recycling industry. A case in the plastic recycling industry is presented to demonstrate the practical application of the financial calculation functions developed in the paper. In particular, the profitability maximization concept for the plastic recycling industry was examined, based on the theory of demand and supply. By estimating the profit realizable on regular as well as high product demand, part of the objective of the paper was achieved. Inventory principles were further applied to determine optimum inventory levels.&lt;/p&gt;&lt;p&gt;AFRIKAANSE OPSOMMING: Die beginsels van bedryfsingenieurswese word in die artikel toegepas om die maksimisering van winsgewendheid by herwinbaarheidsvraagstukke te bewerkstellig. 'n Voorbeeld wat voorkom by die herwinbaarheid van plastiek word voorgehou om te toon hoedat finansiële modellering aangewend kan word. Voorraadhouding onder toestande van stabiele en toenemende vraag word behandel en in besonderheid ondersoek.&lt;/p&gt