Influence Of Short Heat Treatment On The Microstructures And Mechanical Properties Of Thixoformed Aluminum Alloy Composite

Typical T6 heat treatment is commonly applied to aluminum alloy to improve mechanical strength and prevent a catastrophic failure. However, previous studies of T6 have not dealt with aluminum alloy reinforced by carbon nanotubes composite in great detail. In addition, the T6 heat treatment is time-consuming and incurred a high operational cost to production. The present study was designed to determine the effect of a short T6 (ST6) on mutiwalled carbon nanotubes (MWCNT)-A356 alloy composite. The ST6 consists of 1 hour-solution treatment (ST), water quenching at room temperature, and 2 hoursartificial aging (AA). The results revealed that a total of ST and AA is enough to dissolve soluble phases and homogenize alloy elements, and MWCNT particles to be distributed uniformly in the matrix. The effectiveness of the ST6 heat treatment was also shown in the overall improvement of the alloy and composite mechanical properties against the standard T6 heat treatment. The highest values of yield strength, ultimate tensile strength, elongation to fracture, and hardness of the composite obtained were 215 MPa, 277 MPa, 6.8%, and 106.4 HV respectivel

An Investigation of the Impact of Cylindrical Grinding Parameters on Surface Roughness

This paper presented an investigation of impact of cylindrical grinding parameter to surface roughness on SUS316 stainless steel. Grinding is the most common process when the workpiece demands good surface, dimensional and geometrical quality. In this experiment, the finding is the actual effect of surface roughness and the relationship for each parameter that have been choosing. The method that has been used to design the experiment was Design of Experiment (DOE) full factorial with two levels. The surface roughness of the workpiece has been analyzed by using a Portable Roughness Measurement Machine. The data will be compared and analyzed using MINITAB 14 software. The graphs have been created to shows the optimum factor and interaction between the factors. This experiment runs using three factors which are traverse speed, work speed and depth of cut

Különböző érettségi fokú szamóca és kajszibarack néhány fizikai és kémiai jellemzője

Die Verfasser studierten im Laufe ihrer Untersuchungen die Änderung des Penetrationswertes, den Trockensubstanzgehalt, den Ascorbinsäuresowie den gesamten und reduzierenden Zuckergehalt in reifen, halbreifen und unreifen Sorten der Erdbeere und Aprikose. Ihre Resultate können wie folgt zusammengefasst werden: 1. Im Laufe des Reifungsprozesses nimmt bei Erdbeeren, wie auch bei Aprikosen der Penetrationswert zu und der Trockensubstanzgehalt bleibt unverändert. 2. Bei Erdbeeren ist der Ascorbinsäuregehalt bei den weniger reifen Früchten höher. Im Falle von Aprikosen besteht kein signifikanter Unterschied zwischen dem Ascorbinsäuregehalt der reifen und unreifen Früchte. 3. Der reduzierende und gesamte Zuckergehalt ändert sich nur in geringem Masse bei verschiedenen Graden der Reifung, Die Änderungen erweisen sich im Falle von Erdbeeren als geringer und der höchste Zuckergehalt kann bei halbreifen Früchten beobachtet werden. In the course of the investigations the changes in penetration value, and the contents of dry matter, ascorbic acid, total and reducing sugars were studied in ripe, semi-ripe and unripe varieties of strawberry and apricot. The experimental results may be summarized as follows. 1. Both in case of strawberry and of apricot the penetration value increases whereas the dry matter content remains unchanged with the progress of ripening. 2. The content of ascorbic acid of strawberry is higher in the less ripe fruits. In case of apricots no significant difference could be observed in the content of ascorbic acid of ripe and semi-ripe fruits. 3. Contents of reducing and total sugars exhibited only minute changes at the various degrees of ripeness. These changes were of minor nature in case of strawberry. The highest sugar content appeared in semi-ripe fruits. Les auteurs ont étudié les variations des valeurs de pénétration, la teneur en matiére séche, la teneur en acide ascorbique ainsi qu’en sucres totaux et réducteurs dans des espéces müres, demi-müres et vertes de fraises et d’abricots. Le résumé de leur travaux est le suivant: 1. Chez les fraises comme chez les abricots la valeur de pénétration augmente au cours de la maturation, tandis que la matiére séche ne varié pás. 2. Chez les fraises la teneur en acide ascorbique est plus élevée dans les fruits moins műrs. Chez les abricots la teneur en acide ascorbique des fruits mürs ne montre pas de variations signifiantes, comparée ä celles des fruits demi-mürs. 3. Chez les fruits de divers degrés de maturité on n’observe que de faibles variations dans les teneurs respectives des sucres totaux et réducteurs. Les variations sont encore plus faibles chez les fraises. La teneur la plus élevée en sucres se fait observer chez les fruit demi-mürs

Investigation Of Wear And Corrosion Characteristics Of Short Heat Treated Thixoformed Aluminium Alloy

The thixoformed Al-Si-Cu alloys play an important role in automotive and engineering industries due to their wear resistance properties. This investigation looks into the wear and corrosion behaviors of thixoformed Al-Si-Cu alloy. Attempt has been made to relate the coefficient of friction (CoF) and corrosion rate on the short series of T6-heat treatment of thixoformed LM4 aluminium alloy. The short T6 heat treatment involves the application of solute solutioning, quenching and artificial ageing. Dry sliding condition using a pin-on-disc configuration against the SKD II steel disk under a constant load, distance and speed of 10 N, 1000 m and 0.1 m/s respectively was conducted to investigate the wear. The CoF of thixoformed shows an improvement of 5% where the T6 treated alloy is 0.4299 as compared to the 0.4537 untreated LM4 alloy. Furthermore, a significant reduction of 54% from 2.5459x10-4 mmpy to 1.1697x10-4 mmpy corrosion rate was also noted between the untreated and treated thixoformed alloy. Therefore, the alloys that undergone the short T6 heat treatment cycle generally improved the wear and corrosion resistant as compared to the alloys without heat treatment

High Quality Factor Using Nested Complementary Split Ring Resonator For Dielectric Properties Of Solids Sample

A Nested complementary split ring resonator (CSRR) was proposed based on planar structure. The main objective of this work is to get a higher quality factor (Q-factor) with minimal error detection of complex permittivity. The sensor operated at the 3.37GHz resonant frequency and simulated by ANSYS HFSS software. Subsequently, the designed sensor has been fabricated and tested with the presence of several material under test (MUTs) placed over the sensor. The result achieved high unloaded Q-factor, 464. There has been proof of good agreement concerning the results between theoretical, simulation, and measured parameters of error detection, which is below 13.2% real part permittivity and 2.3% the loss tangent. The proposed sensor is practically useful for the food industry, bio-sensing, and pharmacy industry applications

Review of recent microwave planar resonator-based sensors: Techniques of complex permittivity extraction, applications, open challenges and future research directions

Recent developments in the field of microwave planar sensors have led to a renewed interest in industrial, chemical, biological and medical applications that are capable of performing real-time and non-invasive measurement of material properties. Among the plausible advantages of microwave planar sensors is that they have a compact size, a low cost and the ease of fabrication and integration compared to prevailing sensors. However, some of their main drawbacks can be considered that restrict their usage and limit the range of applications such as their sensitivity and selectivity. The development of high-sensitivity microwave planar sensors is required for highly accurate complex permittivity measurements to monitor the small variations among different material samples. Therefore, the purpose of this paper is to review recent research on the development of microwave planar sensors and further challenges of their sensitivity and selectivity. Furthermore, the techniques of the complex permittivity extraction (real and imaginary parts) are discussed based on the different approaches of mathematical models. The outcomes of this review may facilitate improvements of and an alternative solution for the enhancement of microwave planar sensors’ normalized sensitivity for material characterization, especially in biochemical and beverage industry applications

Electrical Equivalent Model Of Symmetrical Split Ring Resonator Sensor-Based Microwave Technology

In this paper, a microwave planar sensor based on symmetrical split ring resonator (SSRR) is investigated. This sensor uses ring resonator with slits at 0o and 180o angles as method to realize the harmonic resonant frequency response and then, it integrated with symmetrical split ring for suppressing the undesired harmonic spurious. Compact size, simplicity, cost effective, and ease of fabrication are the main advantage of SSRR sensor. The model of analytical equivalent circuit is proposed and the characteristic of band-pass and band-stop are derived and investigated for the analysed SSRR with/without spurliners filters. The performance and sensitivity of the SSRR sensor is high with an average accuracy between 96% to 98 % at narrow band frequencies. This type of resonators sensors can detect the material properties under their chemical or physical changes which is essential for numerous applications such as quality control, agriculture, bio-sensing, medicine and pharmacy, food industry, and material science

Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015

SummaryBackground The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform debates on the importance of addressing risks in context. Methods We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defined criteria for convincing or probable evidence. We extracted relative risk and exposure estimates from randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. We developed a metric that allows comparisons of exposure across risk factors—the summary exposure value. Using the counterfactual scenario of theoretical minimum risk level, we estimated the portion of deaths and DALYs that could be attributed to a given risk. We decomposed trends in attributable burden into contributions from population growth, population age structure, risk exposure, and risk-deleted cause-specific DALY rates. We characterised risk exposure in relation to a Socio-demographic Index (SDI). Findings Between 1990 and 2015, global exposure to unsafe sanitation, household air pollution, childhood underweight, childhood stunting, and smoking each decreased by more than 25%. Global exposure for several occupational risks, high body-mass index (BMI), and drug use increased by more than 25% over the same period. All risks jointly evaluated in 2015 accounted for 57·8% (95% CI 56·6–58·8) of global deaths and 41·2% (39·8–42·8) of DALYs. In 2015, the ten largest contributors to global DALYs among Level 3 risks were high systolic blood pressure (211·8 million [192·7 million to 231·1 million] global DALYs), smoking (148·6 million [134·2 million to 163·1 million]), high fasting plasma glucose (143·1 million [125·1 million to 163·5 million]), high BMI (120·1 million [83·8 million to 158·4 million]), childhood undernutrition (113·3 million [103·9 million to 123·4 million]), ambient particulate matter (103·1 million [90·8 million to 115·1 million]), high total cholesterol (88·7 million [74·6 million to 105·7 million]), household air pollution (85·6 million [66·7 million to 106·1 million]), alcohol use (85·0 million [77·2 million to 93·0 million]), and diets high in sodium (83·0 million [49·3 million to 127·5 million]). From 1990 to 2015, attributable DALYs declined for micronutrient deficiencies, childhood undernutrition, unsafe sanitation and water, and household air pollution; reductions in risk-deleted DALY rates rather than reductions in exposure drove these declines. Rising exposure contributed to notable increases in attributable DALYs from high BMI, high fasting plasma glucose, occupational carcinogens, and drug use. Environmental risks and childhood undernutrition declined steadily with SDI; low physical activity, high BMI, and high fasting plasma glucose increased with SDI. In 119 countries, metabolic risks, such as high BMI and fasting plasma glucose, contributed the most attributable DALYs in 2015. Regionally, smoking still ranked among the leading five risk factors for attributable DALYs in 109 countries; childhood underweight and unsafe sex remained primary drivers of early death and disability in much of sub-Saharan Africa. Interpretation Declines in some key environmental risks have contributed to declines in critical infectious diseases. Some risks appear to be invariant to SDI. Increasing risks, including high BMI, high fasting plasma glucose, drug use, and some occupational exposures, contribute to rising burden from some conditions, but also provide opportunities for intervention. Some highly preventable risks, such as smoking, remain major causes of attributable DALYs, even as exposure is declining. Public policy makers need to pay attention to the risks that are increasingly major contributors to global burden. Funding Bill & Melinda Gates Foundation

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Global, regional, and national age-sex-specific mortality and life expectancy, 1950-2017 : a systematic analysis for the Global Burden of Disease Study 2017

Background Assessments of age-specific mortality and life expectancy have been done by the UN Population Division, Department of Economics and Social Affairs (UNPOP), the United States Census Bureau, WHO, and as part of previous iterations of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD). Previous iterations of the GBD used population estimates from UNPOP, which were not derived in a way that was internally consistent with the estimates of the numbers of deaths in the GBD. The present iteration of the GBD, GBD 2017, improves on previous assessments and provides timely estimates of the mortality experience of populations globally. Methods The GBD uses all available data to produce estimates of mortality rates between 1950 and 2017 for 23 age groups, both sexes, and 918 locations, including 195 countries and territories and subnational locations for 16 countries. Data used include vital registration systetns, sample registration systetns, household surveys (complete birth histories, summary birth histories, sibling histories), censuses (summary birth histories, household deaths), and Demographic Surveillance Sites. In total, this analysis used 8259 data sources. Estimates of the probability of death between birth and the age of 5 years and between ages 15 and 60 years are generated and then input into a model life table system to produce complete life tables for all locations and years. Fatal discontinuities and mortality due to HIV/AIDS are analysed separately and then incorporated into the estimation. We analyse the relationship between age-specific mortality and development status using the Socio-demographic Index, a composite measure based on fertility under the age of 25 years, education, and income. There are four main methodological improvements in GBD 2017 compared with GBD 2016: 622 additional data sources have been incorporated; new estimates of population, generated by the GBD study, are used; statistical methods used in different components of the analysis have been further standardised and improved; and the analysis has been extended backwards in time by two decades to start in 1950. Findings Globally, 18.7% (95% uncertainty interval 18.4-19.0) of deaths were registered in 1950 and that proportion has been steadily increasing since, with 58.8% (58.2-59.3) of all deaths being registered in 2015. At the global level, between 1950 and 2017, life expectancy increased from 48.1 years (46.5-49.6) to 70.5 years (70.1-70.8) for men and from 52.9 years (51.7-54.0) to 75.6 years (75.3-75.9) for women. Despite this overall progress, there remains substantial variation in life expectancy at birth in 2017, which ranges from 49.1 years (46.5-51.7) for men in the Central African Republic to 87.6 years (86.9-88.1) among women in Singapore. The greatest progress across age groups was for children younger than 5 years; under-5 mortality dropped from 216.0 deaths (196.3-238.1) per 1000 livebirths in 1950 to 38.9 deaths (35.6-42.83) per 1000 livebirths in 2017, with huge reductions across countries. Nevertheless, there were still 5.4 million (5.2-5.6) deaths among children younger than 5 years in the world in 2017. Progress has been less pronounced and more variable for adults, especially for adult tnales, who had stagnant or increasing mortality rates in several countries. The gap between male and female life expectancy between 1950 and 2017, while relatively stable at the global level, shows distinctive patterns across super-regions and has consistently been the largest in central Europe, eastern Europe, and central Asia, and smallest in south Asia. Performance was also variable across countries and time in observed mortality rates compared with those expected on the basis of development. Interpretation This analysis of age-sex-specific mortality shows that there are remarkably complex patterns in population mortality across countries. The findings of this study highlight global successes, such as the large decline in under-5 mortality, which reflects significant local, national, and global commitment and investment over several decades. However, they also bring attention to mortality patterns that are a cause for concern, particularly among adult men and, to a lesser extent, wotnen, whose mortality rates have stagnated in many countries over the time period of this study, and in some cases are increasing. Copyright C) 2018 The Author(s). Published by Elsevier Ltd.Peer reviewe