scholarly journals Constructal Law: Optimization as Design Evolution

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Adrian Bejan
Keyword(s):  
Entropy Production ◽  
Flow Resistance ◽  
Ad Hoc ◽  
Human Life ◽  
Maximum Flow ◽  
Minimum Entropy ◽  
Design Evolution ◽  
Constructal Law ◽  
And Migration ◽  
Design In Nature

Here, I review the physics meaning of optimization, knowledge and design evolution, and why these concepts and human activities are profoundly useful for human life. A law of physics is a concise statement that summarizes a phenomenon that occurs in nature. A phenomenon is a fact, circumstance, or experience that is apparent to the human senses and can be described. The design in nature phenomenon facilitates access for everything that flows, evolves, spreads, and is collected: river basins, atmospheric and ocean currents, animal life and migration, and technology (the evolution of the “human-and-machine species,” wealth, life). This phenomenon is summarized by the constructal law: the occurrence and evolution of designs in nature, its time direction. Based on its record, the constructal law accounts for the design phenomenon and also for all the phenomena that have been described individually (ad-hoc) with end-design (destiny) statements of “optimality” (min, max). Most notably, the constructal law accounts for contradictory end-design statements such as minimum entropy production and maximum entropy production, and minimum flow resistance and maximum flow resistance.

scholarly journals The constructal law of design and evolution in nature

2010 ◽  
Vol 365 (1545) ◽  
pp. 1335-1347 ◽  
Author(s):  
Adrian Bejan ◽  
Sylvie Lorente
Keyword(s):  
Entropy Generation ◽  
Flow Resistance ◽  
Scaling Laws ◽  
Minimum Weight ◽  
Finite Size ◽  
Maximum Flow ◽  
Constructal Theory ◽  
Minimum Entropy ◽  
Constructal Law ◽  
Flow Systems

Constructal theory is the view that (i) the generation of images of design (pattern, rhythm) in nature is a phenomenon of physics and (ii) this phenomenon is covered by a principle (the constructal law): ‘for a finite-size flow system to persist in time (to live) it must evolve such that it provides greater and greater access to the currents that flow through it’. This law is about the necessity of design to occur, and about the time direction of the phenomenon: the tape of the design evolution ‘movie’ runs such that existing configurations are replaced by globally easier flowing configurations. The constructal law has two useful sides: the prediction of natural phenomena and the strategic engineering of novel architectures, based on the constructal law, i.e. not by mimicking nature. We show that the emergence of scaling laws in inanimate (geophysical) flow systems is the same phenomenon as the emergence of allometric laws in animate (biological) flow systems. Examples are lung design, animal locomotion, vegetation, river basins, turbulent flow structure, self-lubrication and natural multi-scale porous media. This article outlines the place of the constructal law as a self-standing law in physics, which covers all the ad hoc (and contradictory) statements of optimality such as minimum entropy generation, maximum entropy generation, minimum flow resistance, maximum flow resistance, minimum time, minimum weight, uniform maximum stresses and characteristic organ sizes. Nature is configured to flow and move as a conglomerate of ‘engine and brake’ designs.

Changes in environment as cause for environmentally induced migration of people

2017 ◽  
pp. 527-537
Author(s):  
Aleksandra Ljustina
Keyword(s):  
Ad Hoc ◽  
Social Issues ◽  
Human Life ◽  
Modern Society ◽  
Human Interaction ◽  
Complex Relation ◽  
Environmental Migration ◽  
Global Environmental ◽  
Adequate Definition ◽  
The Subject

Migration is one of the oldest and most used strategies for overcoming negative social issues. Despite the fact that it is historically deeply rooted, environmental migration as a social phenomenon has only recently become the subject research of numerous scientific fields. However, the study of current environmental migration is characterized by a number of issues, such as absence of an adequate definition and multi-causality of environmental migration. In this paper, through conceptual framework, author analyzed two main questions: who are environmental migrants and what reasons cause environmental migration. Due to the destruction of the global environmental balance, as well as accumulated environmental disturbances, it is likely that environmental migration will increase in future and there is nowhere you cannot make more use of scientific and professional projection of the future than in demographic and environmental spheres of human life. There is no doubt that our future is unpredictable. However, the environmental factors influencing the pattern of human interaction with the environment must be taken into account when projecting future development of the modern society. Such is the context in which the complex relation among migration, change and the environment has to be studied. In order to establish the basis for controlling environmental migration caused by negative changes in the environment, it is necessary to adopt a consistent strategy instead of ad hoc activities that are being used. In this paper, author analyzed societal response for the challenges caused by environmental migration, specifically regarding actions related to governing environmental migrations.

scholarly journals The principle of minimum entropy production and snow structure

2004 ◽  
Vol 50 (170) ◽  
pp. 342-352 ◽  
Author(s):  
Perry Bartelt ◽  
Othmar Buser
Keyword(s):  
Mass Transfer ◽  
Temperature Gradient ◽  
Entropy Production ◽  
Surface Curvature ◽  
The State ◽  
Temperature Gradients ◽  
Curvature Radius ◽  
Minimum Entropy ◽  
Snow Layer ◽  
Minimum Entropy Production

AbstractAn essential problem in snow science is to predict the changing form of ice grains within a snow layer. Present theories are based on the idea that form changes are driven by mass diffusion induced by temperature gradients within the snow cover. This leads to the well-established theory of isothermal- and temperature-gradient metamorphism. Although diffusion theory treats mass transfer, it does not treat the influence of this mass transfer on the form — the curvature radius of the grains and bonds — directly. Empirical relations, based on observations, are additionally required to predict flat or rounded surfaces. In the following, we postulate that metamorphism, the change of ice surface curvature and size, is a process of thermodynamic optimization in which entropy production is minimized. That is, there exists an optimal surface curvature of the ice grains for a given thermodynamic state at which entropy production is stationary. This state is defined by differences in ice and air temperature and vapor pressure across the interfacial boundary layer. The optimal form corresponds to the state of least wasted work, the state of minimum entropy production. We show that temperature gradients produce a thermal non-equilibrium between the ice and air such that, depending on the temperature, flat surfaces are required to mimimize entropy production. When the temperatures of the ice and air are equal, larger curvature radii are found at low temperatures than at high temperatures. Thus, what is known as isothermal metamorphism corresponds to minimum entropy production at equilibrium temperatures, and so-called temperature-gradient metamorphism corresponds to minimum entropy production at none-quilibrium temperatures. The theory is in good agreement with general observations of crystal form development in dry seasonal alpine snow.

Step-Pool Streams: Adjustment to Maximum Flow Resistance

1995 ◽  
Vol 31 (10) ◽  
pp. 2593-2602 ◽  
Author(s):  
Athol D. Abrahams ◽  
Gang Li ◽  
Joseph F. Atkinson
Keyword(s):  
Flow Resistance ◽  
Maximum Flow

MONITORING HUMAN CAPITAL DEVELOPMENT CONDITIONS IN RURAL AREAS

2020 ◽  
Vol 10 (10) ◽  
pp. 2384-2369
Author(s):  
V.G. Zakshevskiy ◽  
◽  
Z.V. Gavrilova ◽  
Keyword(s):  
Human Capital ◽  
Rural Areas ◽  
Policy Development ◽  
Agricultural Sector ◽  
Human Life ◽  
Main Stage ◽  
Human Capital Development ◽  
Integral System ◽  
And Migration ◽  
Capital Development

The article discusses the problems that arise when monitoring the conditions for the development of human capital in rural areas, since, despite the sufficient number of works on monitoring the human capital in rural areas or the agricultural sector, the integral system of quantitative socio-economic indicators for assessing the human capital development conditions in rural areas remains poorly studied. First of all, a basic concept of monitoring is given, as well as an applied concept - monitoring the human capital development conditions in rural areas, which is understood as a system of constant monitoring, collection, registration, storage and analysis of several key parameters that assess the conditions for the formation and development of congenital and accumulated physical, mental and personal abilities and qualities of the population of rural areas, as well as acquiring knowledge and skills that can be used by them in order to deliver economic income or social effect. The monitoring process is presented in detail in the relationship of this category with concepts close to it (diagnostics, as a preliminary stage, monitoring as the main stage, appropriate policy development, as the final stage). The diversity of monitoring indicators used in the social sphere of human life is reflected: for rural areas, for the agrarian sphere, for the regional socio-economic system, for the development of municipalities' social and labor systems, for social factors of the region's development, etc. The authors' idea of an integral system of indicators for monitoring the human capital development conditions in rural areas is given, which is a combination of six blocks: health care, education, culture and sports, demography and migration, infrastructure, as well as socio-economic conditions.

scholarly journals Development of a Priority based System for Emergency Vehicles to Reduce Accidents in VANETs

2020 ◽  
Vol 9 (2) ◽  
pp. 483-486
Keyword(s):  
Waiting Time ◽  
Vehicular Ad Hoc Networks ◽  
Ad Hoc ◽  
Human Life ◽  
Traffic Signals ◽  
Emergency Vehicles ◽  
Movement System ◽  
Hoc Networks ◽  
The Cost ◽  
Vehicle Movement

Due to tremendous increase of vehicles in number leads to excessive congestion of vehicles at intersection of roads. It causing inconvenience to emergency vehicles like Ambulance and Fire brigade etc, ultimately which is the cost of human life To avoid this, Emergency Vehicles will have to give high priority to overcome from the congestion. Vehicular Ad-Hoc Networks (VANETs) is a network which is used to create a temporary communication among the vehicles. In this paper, priority based vehicle movement system is proposed to give high priority to emergency vehicles and establishing communication among the vehicles through VANET. Due to this high priority, there is no necessity to wait for the emergency vehicles at the traffic signals to get the green signal while communicating with traffic controller. In this paper, SUMO simulator is used for experimental analysis. The result indicates that the proposed methodology reduces the waiting time when compared to the existing system.

scholarly journals A Biomechanical Evaluation of the Epidural Neurolysis Procedure

2012 ◽  
Vol 1;15 (1;1) ◽  
pp. E89-E97
Author(s):  
Christof Birkenmaier
Keyword(s):  
Experimental Study ◽  
Epidural Space ◽  
Flow Resistance ◽  
Maximum Flow ◽  
Mechanical Effect ◽  
Treatment Situation ◽  
Axial Forces ◽  
Key Words Epidural ◽  
Surgery Department

Background: The epidural lysis of adhesions (ELOA) procedure supposedly has a biomechanical component in addition to the targeted injection of medications into the epidural space. It is assumed that the catheters used for the ELOA procedure can release epidural scars and adhesions. Objectives: To evaluate the possible biomechanical effects of the typically used catheters and to put these effects into clinical perspective. Study Design: Experimental study. Setting: The biomechanical laboratory of an academic orthopedic surgery department. Methods: Experimental setups were devised that allow for the measurement of the 3 main forces that can be exerted by manipulating a catheter in the epidural space or by injecting fluids through such a catheter: axial forces, torsional forces, and hydraulic effects. Results: The maximum axial forces measured under extremely tight catheter guidance were 7 newton (N), whereas the maximum forces under conditions that more likely reflect a real treatment situation were between 1 and 2 N. The maximum torsional forces measured were 0.3 N under extremely tight catheter guidance and 0.01 N under more realistic conditions. The maximum flow that could be achieved through the typical catheter using normal saline and the maximum possible thumb pressure onto a 5 mL or a 10 mL Luer-Lock syringe was 0.48 mL/ s. Given these results and other data available to us, it appears impossible that the ELOA procedure with typically used catheters has any relevant mechanical effect. Limitations: Like with any experimental study, the realities of an in vivo situation can only be modeled to a limited degree. The main limitation of our study is that we cannot calculate, measure, or simulate neither the flow resistance between an epidural adhesion pocket and the open, local epidural space nor the flow resistance between the open, local epidural space and the larger epidural space as well as the retroperitoneal space. Conclusions: According to our findings and arguments, the ELOA procedure is predominantly a method for the highly targeted application of epidural medications and possibly also has a lavage effect. A mechanical lysis of scars or adhesions appears unlikely. Key words: epidural lysis of adhesions, epidural neurolysis, epidural neuroplasty, biomechanical, experimental, epidural, catheter, back pain, sciatica

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