Thermodynamic Condition and Behavior of Precipitates in Al2O3p/7055 Composites with Cryogenic Treatment

2013 ◽  
Vol 575-576 ◽  
pp. 378-381
Author(s):  
Hong Ming Wang ◽  
Tian You Xing ◽  
Guirong Li ◽  
Xue Ting Yuan ◽  
Yu Tao Zhao ◽  
...  
Keyword(s):  
Expansion Coefficient ◽  
Driving Forces ◽  
Cryogenic Treatment ◽  
Weight Percent ◽  
Balance Theory ◽  
Thermodynamic Condition ◽  
Heat Expansion ◽  
The Difference ◽  
Precipitated Phases ◽  
And Behavior

The thermodynamic condition and behavior of precipitates were discussed about the Al2O3 p/7055 composites subjected to cryogenic treatments. A kind of software named Thermo-Calc was employed to calculate and analyze the mass amount of several main precipitates based on the thermodynamic balance theory. The results demonstrate that when the temperature decreases from 300K to 77K the precipitated amount of T(AlZnMgCu) and θ (Al2Cu) phases will increase. For S(Al2CuMg) phase, at 175K there is a transverse point from increasing tendency to the opposite. It should be noted that η (MgZn2) is the main precipitated phases in compistes ,which accounts for more than eleven weight percent in one mole material. But the balance mass amount lower a little from 300K to 77K. It is analyzed that the volume shrinkage and lattice contract are the main driving forces for precipiting. Due to the difference of heat expansion coefficient among various phases the anisotropic shirinkge lead to micro voids that will act as the nucleation cores,which faciliate the precipitation.

Behavior of β(Mg17Al12) Phases in Mg-Al Alloy Subject to Cycling Cryogenic Treatment

2013 ◽  
Vol 575-576 ◽  
pp. 390-393 ◽  
Author(s):  
Guirong Li ◽  
Hong Ming Wang ◽  
Yun Cai ◽  
Xue Ting Yuan
Keyword(s):  
Cryogenic Treatment ◽  
Weight Percent ◽  
Al Alloy ◽  
Β Phase ◽  
The Matrix ◽  
Thermo Calc Software ◽  
And Performance ◽  
And Behavior ◽  
Microstructure And Performance ◽  
Electronic Microscope

In Mg-Al alloy β (Mg17Al12) phase is the main precipitate and reinforced phase. The microstructure and performance of alloy are strongly dependent on the morphology and behavior of β phases. In this paper, a kind of Mg-Al alloy is chosen as the research object with 8.92 weight percent aluminum element. The alloy is subjected to cycling cryogenic treatment. The microstructure evolution and thermodynamic balance are analyzed by scanning electronic microscope and Thermo-CALC software. The results show that after two cryogenic treatments the quantity of the precipitate hardening β phase increases and the sizes of the precipitates are refined from 8~10 μm to 2~4μm. This is expected to be due to the decreased solubility of aluminum in the matrix at low temperatures and the significant plastic deformation due to internal differences in thermal contraction between phases and grains.

scholarly journals Large numbers of vertebrates began rapid population decline in the late 19th century

2016 ◽  
Vol 113 (49) ◽  
pp. 14079-14084 ◽  
Author(s):  
Haipeng Li ◽  
Jinggong Xiang-Yu ◽  
Guangyi Dai ◽  
Zhili Gu ◽  
Chen Ming ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Size ◽  
Threatened Species ◽  
Driving Forces ◽  
Population Decline ◽  
Cumulative Effect ◽  
Extinction Time ◽  
Time Period ◽  
Large Numbers ◽  
The Difference

Accelerated losses of biodiversity are a hallmark of the current era. Large declines of population size have been widely observed and currently 22,176 species are threatened by extinction. The time at which a threatened species began rapid population decline (RPD) and the rate of RPD provide important clues about the driving forces of population decline and anticipated extinction time. However, these parameters remain unknown for the vast majority of threatened species. Here we analyzed the genetic diversity data of nuclear and mitochondrial loci of 2,764 vertebrate species and found that the mean genetic diversity is lower in threatened species than in related nonthreatened species. Our coalescence-based modeling suggests that in many threatened species the RPD began ∼123 y ago (a 95% confidence interval of 20–260 y). This estimated date coincides with widespread industrialization and a profound change in global living ecosystems over the past two centuries. On average the population size declined by ∼25% every 10 y in a threatened species, and the population size was reduced to ∼5% of its ancestral size. Moreover, the ancestral size of threatened species was, on average, ∼22% smaller than that of nonthreatened species. Because the time period of RPD is short, the cumulative effect of RPD on genetic diversity is still not strong, so that the smaller ancestral size of threatened species may be the major cause of their reduced genetic diversity; RPD explains 24.1–37.5% of the difference in genetic diversity between threatened and nonthreatened species.

scholarly journals Perbedaan Perkembangan Motorik Bayi Pasca Pemberian Stimulasi Pijatan dan Berenang

2016 ◽  
Vol 2 (1) ◽  
pp. 42-44
Author(s):  
Aryunani Aryunani ◽  
Pipit Festi Wilianarti
Keyword(s):  
Treatment Group ◽  
Motor Development ◽  
Wilcoxon Test ◽  
Growth Disorders ◽  
Data Sampling ◽  
Developmental Growth ◽  
Before And After ◽  
The Difference ◽  
And Behavior ◽  
Attitudes And Behavior

Developmental growth disorders in children under five will result in a decrease in the formation of attitudes and behavior of children in the future. These disorders can be prevented by stimulating development. This study used a quasy experimental design. This research was carried out for 4 months in Privately Practising Midwives in Sidotopo village of Semampir sub-district of North Surabaya with a sample of infants aged 6 to 12 months. Data sampling used consecutive sampling collected through observation using the observation sheet. Data were analyzed using Wilcoxon test to see the difference in gross motor before and after treatment in  the treatment group. In  the treatment group 40% infant experienced an increase of 1-2 segment of motor development and 60% had an increase of 3-4 segments.  

scholarly journals Behavior and Energy Losses of Cows during the Period of Low Temperatures

2021 ◽  
Vol 24 (5) ◽  
pp. 46-53
Author(s):  
Oleksandr O. Borshch ◽  
Oleksandr V. Borshch ◽  
Yurii Mashkin ◽  
Vasyl Malina ◽  
Maxim Fedorchenko
Keyword(s):  
Low Temperatures ◽  
Heat Insulation ◽  
Energy Losses ◽  
Strong Wind ◽  
The Past ◽  
Air Temperatures ◽  
The Difference ◽  
And Behavior ◽  
Positive Effect ◽  
Moderate Climate

Over the past 20 years, dairy farms in Ukraine have been actively introducing the keeping of cows in easy-to-assemble premises. However, in a moderate climate (with four distinct year seasons), the issues of microclimate, energy losses of animals and their behavior during the cold period of the year for keeping in such premises have not been fully studied. The purpose of this work was to study the influence of the heat insulation elements use of side curtains in easy-to-assemble premises during the period of low temperatures on microclimate, energy outgoings for thermoregulation and behavior of cows. The research conducted in the central part of Ukraine (Kyiv region). The research was conducted during January-February (29-43 days of the year) 2021. This period characterized by low average daily temperatures of -12.2– -18.7°С, strong wind gusts and daily precipitation in the form of snow. Two easy-toassemble premises for 400 heads were used for research. Parameters of placements (LxWxH): 150х32х10.5 m. The first one was without the use of curtains heat insulation elements, and the second one was with these elements of heat insulation. It was found that the use of polycarbonate wall heat insulation elements had a positive effect on the microclimate in the placement during the period of low temperatures. Indicators of average daily air temperatures in the placement were 3.2 and 8.8°C higher compared to the temperature in the same premise without the use of heat insulation elements and the environment. The wind speed also differed by 0.18 and 11.04 m/s, respectively. In addition, the heat insulation of the walls affected the temperature under the lying cow (+1.8°C), energy outgoings for thermoregulation (-1.93 MJ) and the number of cows that lay in the period of the lowest temperatures (+3.23-9.83%) compared to the placement without heat insulation elements. The difference in temperature of rubber carpet in the compared premises was significant: +3.3°C in the premises with heat insulation elements compared to the premises without heat insulation

scholarly journals Range Automatic Adjusted Current Transformer Primary Winning

2021 ◽  
Vol 12 (3) ◽  
pp. 3142-3147
Author(s):  
Amirov Sultan Fayzullayevich Et.al
Keyword(s):  
Correction Factor ◽  
Driving Forces ◽  
Operating Mode ◽  
Current Transformer ◽  
Measuring Range ◽  
Secondary Current ◽  
Measuring Devices ◽  
The Difference ◽  
Protection And Control ◽  
And Control

The article discusses the issue of introducing a correction factor for protection and control devices, as the value of the secondary current in a certain range of the auto-adjustable current transformer does not correspond to the value of the secondary current in another range determined by the difference of magnetic driving forces generated by the components of the primary current. Alternatively, an algorithm has been developed to account for the measurement error in this condition in an automatic system that controls the operating mode of the current transformer. It was also found that the output data should be transmitted taking into account the correction factor in order to ensure the proper operation of the protection and measuring devices when the current transformer is switched to another measuring range in the measuring range.

Ethical Consumerism in Tourism

2020 ◽  
pp. 110-133
Author(s):  
Erica Mingotto ◽  
Federica Montaguti ◽  
Luca Scarpellini
Keyword(s):  
Social Studies ◽  
Ethical Consumption ◽  
Recent Survey ◽  
Ethical Consumerism ◽  
Italian Market ◽  
Official Definitions ◽  
The Difference ◽  
And Behavior ◽  
Responsible Tourism

The chapter focuses on responsible tourism as a form of ethical consumption, based on conscious travel choices and behavior. There is a growing demand for responsible tourism, although it seems to be characterized by some inconsistencies, both between tourists' intention and concrete behavior and between these behaviors and the official definitions promoted by the industry and institutions. Starting from the analysis of a recent survey about responsible tourism on the Italian market, the chapter then tries to investigate and explain these gaps, by applying the perspective of social studies and of researches on consumer tribes and new consumers' communities. The findings of the survey discussed in the chapter seem to confirm that consumers have their own perception of responsible tourism and that the meaning is discursively constructed within and outside responsible tourists' communities. Therefore, the intention-behavior gap and the difference between tourists' account of responsible tourism and “institutional” definitions cannot be categorized as true inconsistencies.

scholarly journals Building a Framework of Evaluating Human–Environment Relationships: Considering the Differences between Subjective Evaluations and Objective Assessments

2019 ◽  
Vol 12 (1) ◽  
pp. 167
Author(s):  
Ying Liu ◽  
Wei Deng ◽  
Li Peng
Keyword(s):  
Subjective Evaluation ◽  
Objective Assessment ◽  
Human Environment ◽  
Subjective Evaluations ◽  
The Matrix ◽  
The Difference ◽  
Objective Basis ◽  
And Behavior ◽  
Attitudes And Behavior ◽  
The Relationship

The human–environment relationship is bidirectional, meaning that human attitudes and behavior to nature are at the root of environmental change, while changes in the environment affect human attitudes and behavior. It is necessary to analyze the human–environment relationship from two aspects: (a) Whether there is a good objective basis for maintaining an environment, and (b) whether people report that they are satisfied with that environment. This study attempted to construct a framework to evaluate the human–environment relationship considering these two aspects. The framework consists of three parts: Traditional evaluation, indicator construction, and evaluation considering the relationship between subjective and objective assessment. Traditional evaluations consist of subjective evaluations and objective assessments. Indicator construction focuses on putting forward indicators that quantitively evaluate the human–environment relationship, considering the results of objective assessments and subjective evaluations. The indicators introduced in this study include MD (match degree) and OSC (objective assessment and subjective evaluation comparison) to explain the difference and the relationship between objective assessments and subjective evaluations of the environment. Then, based on the indicator value, a matrix containing four situations (Match-H, Match-L, H-L, and L-H) was constructed to explore why a human–environment relationship may not be harmonious. Since the upper Minjiang River basin is a typical area, because of its intensive human activity, as well as its fragile ecological environment, this study chose it as a case study and used it to verify the framework. Through the framework construction and application, this study found that: (1) The framework of this study provided a more comprehensive method to evaluate the human–environment relationship; (2) as the subjective evaluation was based on individual comprehensive tradeoffs, the evaluation combining the subjective and objective assessment was more accurate; (3) environmental conditions were the basis, and human activities were the key factors, for the coordination of human–environment relationships; so the matrix put forward in this study was necessary for finding the cause of human–environment incongruity.

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