scholarly journals Role of Al in the Solution Strengthening of Mg–Al Binary Alloys

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 84
Author(s):  
Tingting Liu ◽  
Yanglu Liu ◽  
Lu Xiao ◽  
Shibo Zhou ◽  
Bo Song
Keyword(s):  
Binary Alloys ◽  
Solution Treatment ◽  
Hot Extrusion ◽  
Positive Influence ◽  
Al Alloys ◽  
Tensile Yield Strength ◽  
Self Consistent ◽  
Solution Strengthening ◽  
Deformation Modes

Mg–Al binary alloys in the concentration range from 0 to 4.0 wt.% Al have been prepared under conventional casting conditions. The as-cast Mg and Mg–Al alloys after solution treatment were processed via hot extrusion at 350 °C. The results show that Al has a positive influence on grain refinement and solution strengthening. The as-extruded Mg–Al alloys are fully recrystallized, and the tensile yield strength of the binary alloys is two times higher than that of pure Mg. Furthermore, the elongations of Mg–Al alloys are much higher than that of pure Mg. In addition, Mg and Mg–Al alloys were further studied by the viscoplastic self-consistent (VPSC) model to explore the activation and evolution of deformation modes. The simulation results match well with the experimental results.

scholarly journals Development of Hot-Extruded Mg–RE–Zn Alloy Bar with High Mechanical Properties

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1722 ◽  
Author(s):  
Zehua Li ◽  
Jinghuai Zhang ◽  
Yan Feng ◽  
Jinshu Xie ◽  
Yinfu Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Elevated Temperature ◽  
Basal Plane ◽  
Cast Alloy ◽  
Solution Treatment ◽  
Hot Extrusion ◽  
Tensile Yield Strength ◽  
Elevated Temperature Strength ◽  
Solid Solution Treatment

A new elevated-temperature high-strength Mg–4Er–2Y–3Zn–0.4Mn (wt %) alloy was developed by semi-continuous casting, solid solution treatment, and hot extrusion. W phase (Mg3(Er,Y)2Zn3) with fcc structure, long period stacking ordered phases with 18R (Mg10(Er,Y)1Zn1) and 14H (Mg12(Er,Y)1Zn1) structures, and basal plane stacking faults (SFs) was formed in the as-cast alloy, mainly due to the alloy component of (Er + Y)/Zn = 1:1 and Er/Y = 1:1 (at %). After solid solution treatment and hot extrusion, the novel microstructure feature formed in as-extruded alloy is the high number-density nanospaced basal plane SFs throughout all the dynamically recrystallized (DRXed) and un-DRXed grains, which has not been previously reported. The as-extruded alloy exhibits superior tensile properties from room temperature to 300 °C. The tensile yield strength can be maintained above 250 MPa at 300 °C. The excellent elevated-temperature strength is mainly ascribed to the formation of nanospaced basal plane SFs throughout the whole Mg matrix, fine DRXed grains ~2 μm in size, and strongly basal-textured un-DRXed grains with profuse substructures. The results provide new opportunities for the development of deformed Mg alloys with satisfactory mechanical properties for high-temperature services.

Analisis Pengembalian Kredit Terhadap Profitabilitas Pada PT Bank Sumut Cabang Gunungsitoli

Owner ◽  
2019 ◽  
Vol 3 (2) ◽  
pp. 160
Author(s):  
Victorinus Laoli
Keyword(s):  
Data Collection ◽  
Positive Influence ◽  
Business Continuity ◽  
Working Capital ◽  
The People ◽  
Data Collection Technique

One manifestation of the important role of banking in a region, as implemented by PT Bank Sumut, Gunungsitoli Branch, is to distribute loans for investment, consumption and working capital for the people in the area. The purpose of providing credit for banks is the return of credit that earns interest and can increase income to finance activities and business continuity. From the results of research conducted with this data collection technique, it shows that PT Bank Sumut has a number of loans from 2009 to 2014 which each year rises. From this study, it is also known that the rate of credit repayment has a positive influence on the level of profitability.

Calculation-and-experimental estimation of the role of the frequency ratio in changing the endurance at two-frequency deformation modes

2019 ◽  
Vol 85 (1(I)) ◽  
pp. 64-71 ◽  
Author(s):  
M. M. Gadenin
Keyword(s):  
High Frequency ◽  
Experimental Studies ◽  
Low Frequency ◽  
Reduction Factor ◽  
Single Frequency ◽  
Cyclic Loads ◽  
Small Ratio ◽  
Harmonic Components ◽  
Deformation Modes

The cycle configuration at two-frequency loading regimes depends on the number of parameters including the absolute values of the frequencies and amplitudes of the low-frequency and high-frequency loads added during this mode, the ratio of their frequencies and amplitudes, as well as the phase shift between these harmonic components, the latter having a significant effect only with a small ratio of frequencies. Presence of such two-frequency regimes or service loading conditions for parts of machines and structures schematized by them can significantly reduce their endurance. Using the results of experimental studies of changes in the endurance of a two-frequency loading of specimens of cyclically stable, cyclically softened and cyclically hardened steels under rigid conditions we have shown that decrease in the endurance under the aforementioned conditions depends on the ratio of frequencies and amplitudes of operation low-frequency low-cycle and high-frequency vibration stresses, and, moreover, the higher the level of the ratios of amplitudes and frequencies of those stacked harmonic processes of loading the greater the effect. It is shown that estimation of such a decrease in the endurance compared to a single frequency loading equal in the total stress (strains) amplitudes can be carried out using an exponential expression coupling those endurances through a parameter (reduction factor) containing the ratio of frequencies and amplitudes of operation cyclic loads and characteristic of the material. The reduction is illustrated by a set of calculation-experimental curves on the corresponding diagrams for each of the considered types of materials and compared with the experimental data.

Analisis Peranan Kepuasan Dan Komitmen Sebagai Perantara Pengaruh Kualitas Jasa Tutorial Online Terhadap Loyalitas Mahasiswa

2018 ◽  
Vol 9 (2) ◽  
pp. 18-32
Author(s):  
Andy Mulyana ◽  
Devi Ayuni
Keyword(s):  
Service Quality ◽  
Structural Equation ◽  
Positive Influence ◽  
Management Program ◽  
Equation Modeling ◽  
Online Tutorial ◽  
Student Loyalty ◽  
The Relationship ◽  
Positive Effect

This study aims to evaluate the role of satisfaction and commitment as mediating the effect of service quality on student loyalty as the user of Open University's Online Tutorial. Based on data analysis on student of Management program 229 as respondents with Structural Equation Modeling (SEM), this study found the relationship between: (1) positive influence of service quality to satisfaction and loyalty of students using tuton; (2) the positive effect of satisfaction on student loyalty using tuton; (3) satisfaction is a mediator between service quality and loyalty of students using tuton. Conversely, commitment has no positive effect on student loyalty as a tuton user. In addition, commitment does not mediates the effect of satisfaction on the loyalty of tuton users. Keywords: service quality, satisfaction, commitment, loyalty

The Role of Saline Aerosols in the Prevention and Therapy of Cardio-respiratory and Osteo-muscular Afflictions

2018 ◽  
Vol 69 (10) ◽  
pp. 2826-2832
Author(s):  
Ioan Gabriel Sandu ◽  
Viorica Vasilache ◽  
Andrei Victor Sandu ◽  
Marin Chirazi ◽  
Cezar Honceriu ◽  
...  
Keyword(s):  
Athletic Performance ◽  
Gaseous Medium ◽  
Human Subjects ◽  
Active Surface ◽  
Positive Influence ◽  
Climatic Parameters ◽  
Gaussian Distributions ◽  
Gaseous Media ◽  
Source Number

The saline aerosols generated in gaseous media, as nanodispersions, behave, with respect to the concentration levels and the lifespan, as trimodal distributions (the three domains with Gaussian distributions: fine or Aitken under 50 �m, medium between 50 and 500 mm and, respectively, coarse or large between 500 and 1000 mm). The generation in latent state is dependent on the active surface of the source (number of generator centres, the size and position of the fluorescences, the porosity, size and shape of the source, etc.), the climatic parameters, but also on a series of other characteristics of the gaseous medium. Our team has demonstrated experimentally that saline aerosols, NaCl type, besides the ability to prevent and treat broncho-respiratory and cardiac conditions, through coassistance of saline aerosols of other cations than sodium, and of the iodine anion, have for certain levels of concentrations propitious effects over the immune, bone and muscular systems. Similarly proved has been the positive influence on the development of children, as well the determinant role in increasing athletic performance and of other human subjects performing intense activities.

scholarly journals Event-Based Prospective Memory Deficit in Children with ADHD: Underlying Cognitive Factors and Association with Symptoms

2021 ◽  
Vol 18 (11) ◽  
pp. 5849
Author(s):  
Floriana Costanzo ◽  
Elisa Fucà ◽  
Deny Menghini ◽  
Antonella Rita Circelli ◽  
Giovanni Augusto Carlesimo ◽  
...  
Keyword(s):  
Prospective Memory ◽  
Positive Influence ◽  
Attentional Focus ◽  
Adhd Group ◽  
Typically Developing ◽  
Children With Adhd ◽  
The Road ◽  
Hyperactivity Disorder ◽  
Event Based

Event-based prospective memory (PM) was investigated in children with Attention deficit/hyperactivity disorder (ADHD), using a novel experimental procedure to evaluate the role of working memory (WM) load, attentional focus, and reward sensitivity. The study included 24 children with ADHD and 23 typically-developing controls. The experimental paradigm comprised one baseline condition (BC), only including an ongoing task, and four PM conditions, varying for targets: 1 Target (1T), 4 Targets (4T), Unfocal (UN), and Reward (RE). Children with ADHD were slower than controls on all PM tasks and less accurate on both ongoing and PM tasks on the 4T and UN conditions. Within the ADHD group, the accuracy in the RE condition did not differ from BC. A significant relationship between ADHD-related symptoms and reduced accuracy/higher speed in PM conditions (PM and ongoing trials), but not in BC, was detected. Our data provide insight on the adverse role of WM load and attentional focus and the positive influence of reward in the PM performance of children with ADHD. Moreover, the relation between PM and ADHD symptoms paves the road for PM as a promising neuropsychological marker for ADHD diagnosis and intervention.

scholarly journals Being a Patient Representative Is More Work Than Being a Patient Advocate—Done Right, It Is Also Likely to Be More Effective

2021 ◽  
Vol 28 (2) ◽  
pp. 1017-1019
Author(s):  
Richard Wassersug
Keyword(s):  
Health Outcomes ◽  
Background Knowledge ◽  
Positive Influence ◽  
Patient Advocate ◽  
Different Types ◽  
Health Related ◽  
Patient Representative

For a patient to be effective as a “patient representative” within a health-related organization, work and more than just accepting an honorific title is required. I argue that for a patient to be most effective as a patient representative requires different types of background knowledge and commitment than being a “patient advocate”. Patients need to be cautious about how, when, and where they take on an official role of either an “advocate” or “representative”, if they truly want to be a positive influence on health outcomes.

Microstructural Evolutions, Hot Deformation and Work Hardening Behaviour of Novel Al–Zn Binary Alloys Processed by Squeezing and Hot Extrusion

2021 ◽  
Author(s):  
S. Sivasankaran ◽  
K. R. Ramkumar ◽  
Hany R. Ammar ◽  
Fahad A. Al-Mufadi ◽  
Abdulaziz S. Alaboodi ◽  
...  
Keyword(s):  
Work Hardening ◽  
Hot Deformation ◽  
Binary Alloys ◽  
Hot Extrusion

scholarly journals A Short Review on the Phase Structures, Oxidation Kinetics, and Mechanical Properties of Complex Ti-Al Alloys

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1677
Author(s):  
Hooi Peng Lim ◽  
Willey Yun Hsien Liew ◽  
Gan Jet Hong Melvin ◽  
Zhong-Tao Jiang
Keyword(s):  
Mechanical Properties ◽  
Oxidation Kinetics ◽  
Mass Gain ◽  
Short Review ◽  
Al Alloys ◽  
Alloying Elements ◽  
Isothermal Exposure ◽  
Solid Solution Strengthening ◽  
Phase Structures ◽  
Solution Strengthening

This paper reviews the phase structures and oxidation kinetics of complex Ti-Al alloys at oxidation temperatures in the range of 600–1000 °C. The mass gain and parabolic rate constants of the alloys under isothermal exposure at 100 h (or equivalent to cyclic exposure for 300 cycles) is compared. Of the alloying elements investigated, Si appeared to be the most effective in improving the oxidation resistance of Ti-Al alloys at high temperatures. The effect of alloying elements on the mechanical properties of Ti-Al alloys is also discussed. Significant improvement of the mechanical properties of Ti-Al alloys by element additions has been observed through the formation of new phases, grain refinement, and solid solution strengthening.

scholarly journals How Does Metro Maintenance Staff’s Risk Perception Influence Safety Citizenship Behavior—The Mediating Role of Safety Attitude

2021 ◽  
Vol 18 (10) ◽  
pp. 5466
Author(s):  
Huaiyuan Zhai ◽  
Mengjie Li ◽  
Shengyue Hao ◽  
Mingli Chen ◽  
Lingchen Kong
Keyword(s):  
New York ◽  
Risk Perception ◽  
Positive Influence ◽  
Attitude Scale ◽  
Citizenship Behavior ◽  
Accident Rate ◽  
Human Errors ◽  
Mediating Role ◽  
Safety Attitude

The accident rate is high in subway maintenance work, and most of the accidents are caused by human factors, especially the lack of sensitivity to risk perception, the lack of rigorous attitude towards safety and the lack of safe citizenship behavior (SCB). Therefore, it is very important to study the risk perception (RP), safety attitude (SA) and SCB of metro maintenance staff in order to reduce the accident rate. In order to reduce human errors and accidents, this study analyzed the influence of metro maintenance staff’s RP on their SCB and the mediating role of SA. Based on previous studies, this paper uses the risk perception scale, safety attitude scale and safety citizenship behavior scale as research tools. A survey was administered at the Subway Company, and altogether 268 valid questionnaires were used, and the data were analyzed by SPSS19.0 (IBM, Armonk, NY, USA) and AMOS 24.0 (IBM, Armonk, New York, NY, USA). The result reveals that SA plays a complete mediating role between metro maintenance staff’s RP and their SCB; and SA has a positive influence on SCB; RP has a positive influence on SA; and SA positively predicts SCB.

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