Characterization of aluminum silicon/short carbon fiber composites fabricated by novel thixomixing method

The metal matrix composites (MMC) are widely used in different applications and offer high strength-to-weight ratio. In this thesis, it was developed a novel method to fabricate composite material in semi-solid state of aluminum with short carbon fibers (Cs f ). The semi-solid slurry of aluminum silicon alloys represent thixotropic feature when sheared. The intensive shear stress created by high viscosity at mushy zone impacts on uniform distribution and effective dispersion of Cs f into the eutectic without serious physical or chemical damages. For this process, called thixomixing, a prototype mixer was designed to study on A356, A357 and hypereutectic 4047 alloys. The homogenous distribution ofCs f were obtained under optimum conditions: around 48% of solid fraction in slurry and 100 rpm mixing speed. The Cs f was wetted in the molten of eutectic when the primary a-phase was formed. Deposition of silicon or intermetallic compounds on the fiber surface improves wettability aluminum and provides relatively good adherence. The extruded and T6 heat treated Al composites had around 24% improvement of mechanical strength. The fractography analysis illustrated the ductile fracture with some plastic deformation as the results of dimples and some fiber pullout in the fractured surface. Ultra-micro hardness evaluation showed relatively good interfacial bonding after heat treatment. Hypereutectic aluminum alloy (4047)/Cs f composite was used to evaluate the tribological properties. This composite showed low coefficient of friction, when the Cs f acts self-lubricant material. Taguchi method was employed to design the experiments to analyze the effects of the sliding speed, applied load and the volume fraction of Cs f on the tribological properties of thixomixed Al/Cs f composite. The contribution percentage for each parameter was determined by the analysis of variance. The results were indicated that Al/Cs f composite had better tribological properties than matrix alloy due to the carbon as solid-lubricant. The interfacial adherence of matrix/Cs f was shown with no fibers pull out in the tracking area. The presence of coherent and adherent graphite-rich layer on the worn surface was detected. Electrochemical tests were conducted over three alloys, Al/Cs f composites with and without T6 heat treatment. The exposure surfaces were evaluated by SEM in order to find out the localized corrosion and the interfacial adherence. The Cs f , Si particles and iron-intermetallics play as cathode and the matrix as anode to form a galvanic couples. The corrosion current density was decreased for un-reinforced alloys in compare to the composite samples.Los compuestos de matriz metálica (MMC) son ampliamente utilizados en diferentes aplicaciones y ofrecen una alta relación resistencia-peso. En esta tesis se ha desarrollado un nuevo método de conformación en estado semisólido de materiales compuestos en base aluminio con fibras cortas de carbono (Cs f ). Las aleaciones de aluminio en estado semisólido presentan características tixotrópicas cuando son agitadas. La tensión de cizalla provocada por la alta viscosidad repercute en la distribución uniforme y eficaz de las fibras en el constituyente eutéctico, sin daños físicos o químicos graves. Para este proceso, denominado thixomixing, se ha diseñado un prototipo mezclador, con el cual se han estudiado las aleaciones A356, A357 y la aleación hipereutéctica 4047. La óptima distribución del Cs f se ha obtenido en las siguientes condiciones: en torno al 48% de fracción sólida y 100 rpm de velocidad de mezclado. La deposición de silicio o de compuestos intermetálicos en la superficie de la fibra mejora su mojabilidad en el aluminio y proporciona relativamente buena adherencia. Los materiales compuestos base alumino extruidos y sometidos a tratamiento térmico T6 tuvieron una mejoría en torno al 24% de su resistencia mecánica. El análisis fractográfico indica una fractura de carácter d¿uctil, dando como resultado la presencia en la superficie fracturada de hoyuelos y el desprendimiento de algunas fibras. La evaluación mediante ensayos de ultramicrodureza mostró una relativamente buena adherencia fibra-matriz después del tratamiento térmico. Para evaluar las características tribológicas se utilizó como matriz la aleación de aluminio hipereutéctica (4047) reforzada con fibras de carbono. Este material compuesto mostró un bajo coeficiente de fricción debido al carácter lubricante del Cs f . Se ha realizado un diseño de experimentos utilizando el método Taguchi para analizar el efecto de la velocidad de deslizamiento, la carga aplicada y la fracción de volumen de los Cs f en las propiedades tribológicas del material compuesto Al/Cs f . El porcentaje de contribución de cada parámetro se determinó mediante análisis de varianza. Los resultados han indicado que el material compuesto presenta mejores propiedades tribológicas que la matriz debido al carácter lubricante del Cs f . La ausencia de fibras en el canal de desgaste demuestra la buena adherencia entre fibras y matriz. En la superficie del canal de desgaste se observó la presencia de una capa coherente y adherente rica en grafito. Los ensayos electroquímicos se realizaron en las tres aleaciones y en los tres materiales compuestos Al/Cs f , con y sin tratamiento térmico T6. El Cs f , las partículas de Si y los compuestos intermetálicos de hierro actúan como cátodo en una matriz de aluminio anódica, formando pares galvánicos. La densidad de corriente de corrosión es menor en las aleaciones sin reforzar en comparación con los materiales compuestos

The effect of antidepressant treatment on the HPA axis, changes in depression score and serum levels of TNF-α in depressed infertile women

Objectives: This study aimed to explore the effect of antidepressant treatment on the HPA axis, changes in depression score, and serum levels of TNF-α in depressed infertile women. Methods: In this randomized controlled trial research, 60 infertile women who had undergone in vitro fertilization (IVF) treatment with depression scores between 16-47 were divided into two groups. The intervention group with fluoxetine capsule was under treatment for two months before the embryo transfer, while the control group was given placebo. Depression score, serum levels of tumor necrosis factor alpha (TNF-α) as well as cortisol hormone levels were measured and recorded both before and after the intervention. The data were analyzed using SPSS version 21 software. Results: We analyzed the data related to 55 subjects who had undergone embryo transfer. 7 subjects in the intervention group and 3 in the control group got pregnant. We observed a significant decrease in the depression score (p < 0/001) and serum levels of cortisol (p = 0/001) in the intervention group. There was a significant increase in the serum levels of TNF-α in the intervention group (p < 0/001). There was a significant difference between the two groups in the number of pregnancies (p = 0.04). However, there was no statistical difference between them with regard to the number of harvested oocytes (p = 0.174). Discussion: Decrease in depression score and cortisol level, and an increase in the levels of TNF-α in the intervention group caused any changes in the number of oocytes in comparison with the control group. However, the number of pregnancies was larger in the intervention group

Effect of 940nm Diode Laser Irradiation on Microtensile Bond Strength of an Etch and Rinse Adhesive (Single Bond 2) to Dentin

Statement of the Problem: Laser can influence bonding mechanism by increasing the penetration depth of adhesive in smear layer. The effect of 940 nm diode laser on microtensile bond strength of adhesive to dentin has not been investigated in previous studies. Purpose: The aim of this study was to evaluate the effect of 940 nm diode laser irradiation on microtensile bond strength of Single Bond 2 to dentin. Materials and Method: Thirty sound premolars extracted for orthodontic reasons were randomly divided into five groups as follows: G1 or control: etching+ Single Bond2 (SB); G2: diode laser (940 nm wavelength, 1W power, continuous mode)+ etching+ SB; G3: etching+ laser irradiation+ SB; G4: etching+ SB+ laser irradiation+ adhesive curing; G5: etching+ laser irradiation+ SB +laser irradiation +adhesive curing. After the bonding procedure, Z250 composite resin was applied on the dentin surface in three layers of 2 mm thickness. After 24 hours of immersion in distilled water at 37°C and thermocycling for 1000 thermal cycles, the teeth were sectioned into 1mm2 sticks. The microtensile bond strength was measured using a universal testing machine. Bond strength (MPs) was analyzed by one-way ANOVA followed by HSD post hoc Tukey’s test (α=0.05). Results: G4 (38.35±8.99) showed the significant highest bond strength compared to other groups (p= 0.000). G5 (25.16±6.14) showed significantly higher bondstrength than the control group (18.85±4.79) (p= 0.032).Bond strength of G2 (23.39±6.07) and G3 (22.85±5.11) groups was the same and similar to that in the control group (p> 0.05). Conclusion: Based on the results of this study, it may be concluded that dentin surface irradiation with 940 nm diode laser after adhesive application and prior to curing can significantly increase the bond strength of composite to dentin

Is Acceptable Noise Level Affected by the Number of Competitive Talkers? An Implication of Informational Masking and Listening in Dips for Acceptable Noise Level Mechanism

Background and Aim: The Acceptable Noise Level (ANL), which is an effective clinical tool for quantitative assessment of noise tolerance, is affected by some known variables related to both subject and testing materials. The present study examined how the characteristics of different babble noises may affect the ANL results in normal adult listeners. Methods: Forty Persian listeners with normal hearing participated. In addition to typical ANL testing with 12-talker noise, the ANL was obtained in 8 different conditions varying in number of talkers from 2 to 10 in the babble noises presenting forward and backward. Results: There was a significantly lower ANL for 2-talker babble compared to 4, 8, 10, and 12-talker babble in both forward and backward noise conditions. With the increase in talkers in noise, the ANL becomes worse but reaches almost a plateau with more than 4 talkers in babble noise. There was a statistically significant difference between 2-talker forward and 2-talker backward noises, with no difference for the other conditions. Conclusion: This finding that the ANL is affected by the number of talkers in babble noise and by the forward and backward background noise suggests that informational masking and listening in dip mechanisms are involved in ANL for normal hearing people at least

Thixomixing as novel method for fabrication aluminum composite with carbon and alumina fibers

This study focuses on a novel method for dispersion and distribution of reinforcement under high intensive shear stress to produce metal composites. The polyacrylonitrile (PAN)-based short carbon fiber (Csf) and Nextel 610 alumina fiber were dispersed under high intensive shearing at mushy zone in semi-solid of A356 by a novel method. The bundles and clusters were embedded by infiltration of slurry into the clusters, thus leading to a uniform microstructure. The fibers were embedded homogenously into the aluminum around 576-580°C with around 46% of solid fraction. Other experiments at 615°C and 568°C which are contained 0% and 90% solid respectively were not successful for dispersion and infiltration of aluminum into bundles of Csf. The alumina fiber has been cracked by high shearing load. The morphologies and crystalline phase were evaluated by SEM and XRD. The adopted thixo-process effectively improved the adherence and distribution of Csf into Al that can be developed to produce various composites by thixomixing.This study focuses on a novel method for dispersion and distribution of reinforcement under high intensive shear stress to produce metal composites. The polyacrylonitrile (PAN)-based short carbon fiber (Csf) and Nextel 610 alumina fiber were dispersed under high intensive shearing at mushy zone in semi-solid of A356 by a novel method. The bundles and clusters were embedded by infiltration of slurry into the clusters, thus leading to a uniform microstructure. The fibers were embedded homogenously into the aluminum around 576-580°C with around 46% of solid fraction. Other experiments at 615°C and 568°C which are contained 0% and 90% solid respectively were not successful for dispersion and infiltration of aluminum into bundles of Csf. The alumina fiber has been cracked by high shearing load. The morphologies and crystalline phase were evaluated by SEM and XRD. The adopted thixo-process effectively improved the adherence and distribution of Csf into Al that can be developed to produce various composites by thixomixing.Peer ReviewedPostprint (author's final draft

Monitoring of fisheries resources in artificial reefs in east of Kish Island waters

Artificial reefs are manmade materials deployed under water in order to improve environment and increase the exploitation of fishing area. Usage of artificial technic has developed due to increase of world population and need to supply of protein, aim to restoring of natural specially rehabilitation of demersal fishes. It has effected to increase the production in order sustainable exploitation. Coasts and Islands have destruction due to over harvesting from ecosystems and other activities by humans and natural, these caused many aquatic as demersal fishes has endangered in Persian Gulf and Oman Sea. The artificial reef is one way or method that can improve the environment and restore the aquatic. Iranian fisheries has established an artificial reefs area in west of Kish Island. This area has studied during one year, Data of assembled fishes and physical sampling were collected in seasonal during spring, summer, autumn and wintered. There were tow treatment for sampling as artificial reefs site and a control site. Collected data has analyzed and evaluated by SPSS and Exel. The results showed that there was significant difference between the sites and assembled fishes in artificial reefs were more than control site. Consequently the artificial reefs can be a tool and technic to improve the marine environment and increase the production of fishes, especially the demersal fishes

Global, regional, and national incidence of six major immune-mediated inflammatory diseases: findings from the global burden of disease study 2019

BACKGROUND: The causes for immune-mediated inflammatory diseases (IMIDs) are diverse and the incidence trends of IMIDs from specific causes are rarely studied. The study aims to investigate the pattern and trend of IMIDs from 1990 to 2019. METHODS: We collected detailed information on six major causes of IMIDs, including asthma, inflammatory bowel disease, multiple sclerosis, rheumatoid arthritis, psoriasis, and atopic dermatitis, between 1990 and 2019, derived from the Global Burden of Disease study in 2019. The average annual percent change (AAPC) in number of incidents and age standardized incidence rate (ASR) on IMIDs, by sex, age, region, and causes, were calculated to quantify the temporal trends. FINDINGS: In 2019, rheumatoid arthritis, atopic dermatitis, asthma, multiple sclerosis, psoriasis, inflammatory bowel disease accounted 1.59%, 36.17%, 54.71%, 0.09%, 6.84%, 0.60% of overall new IMIDs cases, respectively. The ASR of IMIDs showed substantial regional and global variation with the highest in High SDI region, High-income North America, and United States of America. Throughout human lifespan, the age distribution of incident cases from six IMIDs was quite different. Globally, incident cases of IMIDs increased with an AAPC of 0.68 and the ASR decreased with an AAPC of −0.34 from 1990 to 2019. The incident cases increased across six IMIDs, the ASR of rheumatoid arthritis increased (0.21, 95% CI 0.18, 0.25), while the ASR of asthma (AAPC = −0.41), inflammatory bowel disease (AAPC = −0.72), multiple sclerosis (AAPC = −0.26), psoriasis (AAPC = −0.77), and atopic dermatitis (AAPC = −0.15) decreased. The ASR of overall and six individual IMID increased with SDI at regional and global level. Countries with higher ASR in 1990 experienced a more rapid decrease in ASR. INTERPRETATION: The incidence patterns of IMIDs varied considerably across the world. Innovative prevention and integrative management strategy are urgently needed to mitigate the increasing ASR of rheumatoid arthritis and upsurging new cases of other five IMIDs, respectively. FUNDING: The Global Burden of Disease Study is funded by the Bill and Melinda Gates Foundation. The project funded by Scientific Research Fund of Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital (2022QN38)

The global burden of cancer attributable to risk factors, 2010-19 : a systematic analysis for the Global Burden of Disease Study 2019

Background Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. Methods The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk-outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. Findings Globally, in 2019, the risk factors included in this analysis accounted for 4.45 million (95% uncertainty interval 4.01-4.94) deaths and 105 million (95.0-116) DALYs for both sexes combined, representing 44.4% (41.3-48.4) of all cancer deaths and 42.0% (39.1-45.6) of all DALYs. There were 2.88 million (2.60-3.18) risk-attributable cancer deaths in males (50.6% [47.8-54.1] of all male cancer deaths) and 1.58 million (1.36-1.84) risk-attributable cancer deaths in females (36.3% [32.5-41.3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20.4% (12.6-28.4) and DALYs by 16.8% (8.8-25.0), with the greatest percentage increase in metabolic risks (34.7% [27.9-42.8] and 33.3% [25.8-42.0]). Interpretation The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe

Global, regional, and national incidence of six major immune-mediated inflammatory diseases : findings from the global burden of disease study 2019

DATA SHARING STATEMENT : Data used for the analyses are publicly available from the Institute of Health Metrics and Evaluation (http://www.healthdata.org/; http:// ghdx.healthdata.org/gbd-results-tool).BACKGROUND : The causes for immune-mediated inflammatory diseases (IMIDs) are diverse and the incidence trends of IMIDs from specific causes are rarely studied. The study aims to investigate the pattern and trend of IMIDs from 1990 to 2019. METHODS : We collected detailed information on six major causes of IMIDs, including asthma, inflammatory bowel disease, multiple sclerosis, rheumatoid arthritis, psoriasis, and atopic dermatitis, between 1990 and 2019, derived from the Global Burden of Disease study in 2019. The average annual percent change (AAPC) in number of incidents and age standardized incidence rate (ASR) on IMIDs, by sex, age, region, and causes, were calculated to quantify the temporal trends. FINDINGS : In 2019, rheumatoid arthritis, atopic dermatitis, asthma, multiple sclerosis, psoriasis, inflammatory bowel disease accounted 1.59%, 36.17%, 54.71%, 0.09%, 6.84%, 0.60% of overall new IMIDs cases, respectively. The ASR of IMIDs showed substantial regional and global variation with the highest in High SDI region, High-income North America, and United States of America. Throughout human lifespan, the age distribution of incident cases from six IMIDs was quite different. Globally, incident cases of IMIDs increased with an AAPC of 0.68 and the ASR decreased with an AAPC of −0.34 from 1990 to 2019. The incident cases increased across six IMIDs, the ASR of rheumatoid arthritis increased (0.21, 95% CI 0.18, 0.25), while the ASR of asthma (AAPC = −0.41), inflammatory bowel disease (AAPC = −0.72), multiple sclerosis (AAPC = −0.26), psoriasis (AAPC = −0.77), and atopic dermatitis (AAPC = −0.15) decreased. The ASR of overall and six individual IMID increased with SDI at regional and global level. Countries with higher ASR in 1990 experienced a more rapid decrease in ASR. INTERPRETATION : The incidence patterns of IMIDs varied considerably across the world. Innovative prevention and integrative management strategy are urgently needed to mitigate the increasing ASR of rheumatoid arthritis and upsurging new cases of other five IMIDs, respectively.The Global Burden of Disease Study is funded by the Bill and Melinda Gates Foundation. Support from Scientific Research Fund of Sichuan Academy of Medical Sciences & Sichuan Provincial People’s Hospital; Shaqra University; the School of Pharmacy, University of Botswana; the Indian Council of Medical Research (ICMR); an Australian National Health and Medical Research Council (NHMRC) Investigator Fellowship; the Italian Center of Precision Medicine and Chronic Inflammation in Milan; the Department of Environmental Health Engineering of Isfahan University of Medical Sciences, Isfahan, Iran; National Health and Medical Research Council (NHMRC), Australia; Jazan University, Saudi Arabia; the Clinician Scientist Program of the Clinician Scientist Academy (UMEA) of the University Hospital Essen; AIMST University, Malaysia; the Department of Community Medicine, Kasturba Medical College, Mangalore, Manipal Academy of Higher Education, Manipal, India; a Kornhauser Research Fellowship at The University of Sydney; the National Research, Development and Innovation Office Hungary; Taipei Medical University; CREATE Hope Scientific Fellowship from Lung Foundation Australia; the National Institute for Health and Care Research Manchester Biomedical Research Centre and an NIHR Clinical Lectureship in Respiratory Medicine; Kasturba Medical College, Mangalore and Manipal Academy of Higher Education, Manipal; Author Gate Publications; the Cleveland Clinic Foundation and Nassau University Medical center; the Italian Ministry of Health (RRC); King Abdulaziz University (DSR), Jeddah, and King Abdulaziz City for Science & Technology (KACSAT), Saudi Arabia, Science & Technology Development Fund (STDF), and US-Egypt Science & Technology joint Fund: The Academy of Scientific Research and Technology (ASRT), Egypt; partially supported by the Centre of Studies in Geography and Spatial Planning; the International Center of Medical Sciences Research (ICMSR), Islamabad Pakistan; Ain Shams University and the Egyptian Fulbright Mission Program; the Belgian American Educational Foundation; Health Data Research UK; the Spanish Ministry of Science and Innovation, Institute of Health Carlos III, CIBERSAM, and INCLIVA; the Clinical Research Development Unit, Imam Reza Hospital, Mashhad University of Medical Sciences; Shaqra University; Saveetha Institute of Medical and Technical Sciences and SRM Institute of Science and Technology; University of Agriculture, Faisalabad-Pakistan; the Chinese University of Hong Kong Research Committee Postdoctoral Fellowship Scheme; the institutional support of the Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Egypt; the European (EU) and Developing Countries Clinical Trials Partnership, the EU Horizon 2020 Framework Programme, UK-National Institute for Health and Care Research, the Mahathir Science Award Foundation and EU-EDCTP.http://www.thelancet.comam2024School of Health Systems and Public Health (SHSPH)SDG-03:Good heatlh and well-bein

Improving lithium carbonate therapeutics by pegylated liposomal technology: an in vivo study

Bipolar disorder is a chronic mental illness which is associated with high risk of self-harm and suicide. Lithium carbonate has been suggested as a medicine to control and cure this disease. To overcome the complications related to taking lithium carbonate, nanotechnology has come to the aid of scientists. In this study, pegylated liposomal lithium carbonate nanoparticles were prepared by the reverse phase evaporation method to improve the drug’s therapeutic characteristics as well as lessening its side effects. In order to synthesize pegylated liposomal lithium carbonate, phosphatidylcholine, polyethylene glycol 3350 (PEG3350), cholesterol, and lithium carbonate were mixed. The characterization of synthesized nanoparticles was determined by Zetasizer. Encapsulation and drug loading efficiency and release pattern studies were determined through spectrophotometry method. In addition, serum lithium and creatinine levels of the samples were analyzed. The mean diameter, size distribution, and zeta potential for pegylated liposomal particles containing lithium carbonate and blank pegylated liposomal were determined by Zetasizer equal to 102\ua0nm, 0.458, and −25.1\ua0mV; 284.2\ua0nm, 0.427, and −28.3\ua0mV, respectively. Drug loading and encapsulation efficiency were calculated to be 32.87 and 97.4\ua0%, respectively. The drug release pattern demonstrated that the half-life of the nanodrug was approximately two times higher than the standard drug. The results related to the analysis of serum lithium and creatinine levels indicated that the efficiency of liposomal drug formulation was increased compared to the standard drug. Based on the findings, the nanodrug enjoyed a half-life two times higher than that of the standard drug and an efficiency level equal to it