2,144 research outputs found
The Second Demographic Transition Theory: A Review and Appraisal
References to the second demographic transition (SDT) concept/theoretical framework have increased dramatically in the last two decades. The SDT predicts unilinear change toward very low fertility and a diversity of union and family types. The primary driver of these changes is a powerful, inevitable and irreversible shift in attitudes and norms in the direction of greater individual freedom and self-actualization. First, we describe the origin of this framework and its evolution over time. Second, we review the empirical fit of the framework to major changes in demographic and family behavior in the U.S., the West, and beyond. As has been the case for other unilinear, developmental theories of demographic/family change, the SDT failed to predict many contemporary patterns of change/difference. Finally, we review previous critiques and identify fundamental weaknesses of this perspective, and provide brief comparisons to selected alternative approaches
Effect of Listening to A Relaxing Water Sound for Fifteen Minutes On Traumatic Stress Subjects’ Immediate Stress Levels and Electroencephalograms
BACKGROUND: Music and calmness are noteworthy stimulators that significantly affect mental health. Listening to relaxing sounds activates the feeling of wellbeing. The present study aimed to analyze the effect of closed eyes brief exposure to a relaxing water sound on Electroencephalogram (EEG) in pre and post-test states. METHODOLOGY: A total of 20 traumatic stress subjects were included to participate in this study. The subjects were requested to be seated with eyes closed while the sound of water flowing was played for 15 min in between (before and after) the EEG recordings. A subsection of the Sadaf Stress Scale (SSS) i.e. traumatic stress scale was used to assess the traumatic stress and muse (SCR_014418) monitor headband was utilized for EEG evaluation i.e. Alpha waves, Beta waves, Theta waves & Delta waves. RESULTS: Significantly increased theta wave & alpha waves were found after the listening of relaxing water sound in the eyes-closed state. While no significant change was observed in beta & delta waves. Conclusion: The results of this study suggest that exposure to the sound of water flowing quietly significantly generates alteration in brain waves. Although, the applied stimulators were for a brief period changes in frequencies suggest if applied for a longer period it could generate a relaxation state
Benefits and Hazards of Electromagnetic waves; Telecommunication, Physical and Biomedical: a Review
Cloaking using the anisotropic multilayer sphere
We studied a Spherically Radially Anisotropic (SRA) multilayer sphere with an arbitrary number of layers. Within each layer permittivity components are different from each other in radial and tangential directions. Under the quasi-static approximation, we developed a more generalized mathematical model that can be used to calculate polarizability of the SRA multilayer sphere with any arbitrary number of layers. Moreover, the functionality of the SRA multilayer sphere as a cloak has been investigated. It has been shown that by choosing a suitable contrast between components of the permittivity, the SRA multilayer sphere can achieve threshold required for invisibility cloaking
Shear flow-driven electrostatic instabilities in low density and low temperature pair-ion plasmas with and without electrons
Introduction to radar scattering application in remote sensing and diagnostics: Review
The manuscript reviews the current literature on scattering applications of RADAR (Radio
Detecting And Ranging) in remote sensing and diagnostics. This paper gives prime features for
a variety of RADAR applications ranging from forest and climate monitoring to weather forecast,
sea status, planetary information, and mapping of natural disasters such as the ones caused by
earthquakes. Both the fundamental parameters involved in scattering mechanisms of RADAR
applications and the factors affecting RADAR performances are also discusse
A plan for transportation and distribution the products based on multi-objective travelling salesman problem in fuzzy environmental
Transportation and distribution are the most important elements in the work system for any company, which are of great importance in the success of the chain work. Al-Rabee factory is one of the largest ice cream factories in Iraq and it is considered one of the most productive and diversified factories with products where its products cover most areas of the capital Baghdad, however, it lacks a distribution system based on scientific and mathematical methods to work in the transportation and distribution processes, moreover, these processes need a set of important data that cannot in any way be separated from the reality of fuzziness industrial environment in Iraq, which led to use the fuzzy sets theory to reduce the levels of uncertainty. The decision-maker has several goals that he aspires to accomplish for two stages, so, the decision-maker adopted in his work system on a multi-objective travelling salesman problem. A network of paths for transportation and distribution of the products has been designed based on a multi-objective travelling salesman problem, by building a mathematical model that finds the best paths for each stage, taking into account the goals required by the decision-maker. The results obtained from the use of (Lingo) software showed the importance of these methods in determining the optimal path for the processes of collecting and transporting milk from their collection centers to the Al-Rabee factory as a first stage, as well as transporting the final products and distributing them from the Al-Rabee factory to the shopping centers as a second stage
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