دانلود مقاله دینامیک سیالات-زیستی قلب مصنوعی BIOFLUID DYNAMICS OF THE ARTIFICIAL HEART
The heart pumps blood to the human body. Artificial hearts are implanted in patients suffering from severe heart diseases. For the artificial heart system, we need to consider body fluids such as: Blood, intracellular fluids, extra cellular fluids, intravenous fluids and artificial (synthetic) blood. The use of anticoagulants (Heparin or Coumarin) is necessary in the implantation of an artificial organ. These act as blood thinners and prevent thromboembolism. Cardiovascular biomaterials are used to develop artificial heart valves, mechanical heart valves, pacemakers, vascular grafts, oxygenerators and cardiac assist systems (medical devices) like total artificial hearts, intra-aortic balloon pumps etc. Some of the biomaterials used in medicine are metals, polymers ceramics and hydrogels.
دانلود مقاله اصول گاز و حرارت تئوری کشتی هوایی The Basics of Gas and Heat Airship Theory
“The basics of Theory of Gas and Heat Airships” is unique work written by Lev
KONSTANTINOV and it will be published in the journal. The work of uncommon beauty and
elegance includes theory problems and practical recommendations. The work was written for all
those who will simultaneously to ply a theory of airship and its making.
دانلود مقاله بازیافت انرژی از مواد جامد زیستی و بایومس (زیست-توده) یک مروری بر فناوریهای تبدیل حرارتی Energy Recovery from Biosolids and Biomass A Review of Thermal Conversion Technologies
Melbourne Water investigated a broad variety of biosolids reuse options, including energy, fuel, chemical, nutrient, and metal recovery and reuse; use of biosolids as a geotechnical fill or building material extender; and for carbon sequestration. This paper focuses on those technologies capable of recovering energy, fuels, or non-nutrient chemicals from biosolids. Recognizing the higher energy content of other feedstocks and the potential benefits from taking advantage of capital installations‘ economies of scale, Melbourne Water also considered receiving foreign biomass at a potential future energy recovery plant, and hauling their biosolids to off-site facilities. Technologies investigated ranged from the most established, with hundreds of installations, to the most embryonic, that have only been tested in university laboratories. Maturity, scale, feedstock suitability, costs of facilities and market conditions for products were identified for each technology.
دانلود مقاله تطبیق تولید انرژی غیر متمرکز و مصرف محلی: مروری بر سیستمهای انرژی تجدید پذیر با فناوریهای تبدیل و ذخیره Matching decentralized energy production and local consumption: A review of renewable energy systems with conversion and storage technologies
The increasing share of decentralized intermittent renewable energy reinforces the
necessity of balancing local production and consumption. Decentralized energy
systems, powered by renewable energy technologies and incorporating storage and
conversion technologies, are promising options to cope with this challenge. Many
studies have evaluated their potential contributions, but an overview of the statusquo
in both academia and practice is missing. The extant literature lacks a comprehensive
review of the scientific knowledge on decentralized energy systems,
partially attributed to the lack of common terminology. Additionally, it remains
unclear what kind of systems are already implemented today worldwide as they
have not yet been thoroughly analyzed and described. However, pilot projects provide
valuable insights into future applications and operational aspects. To fill these
gaps, an extensive review of the current state of literature and practice is conducted.
To do so, 64 publications and 56 projects were analyzed and an overview is provided
using four criteria: terminology, scope/motivation, application, and technical
configuration. These criteria facilitate the understanding of decentralized energy
systems needed to spur their development and diffusion. Further advancements of
research and practice are discussed. For example, technological learning hinges on
a common terminology and on an identification of optimal technical configurations
per application. There are both avenues for future research.
This article is categorized under:
Energy Systems Analysis > Economics and Policy
Energy Infrastructure > Systems and Infrastructure
Energy and Urban Design > Systems and Infrastructure
Energy Research & Innovation > Systems and Infrastructure
دانلود مقاله مروری بر کاربردهای فناوریهای بازیابی و تبدیل انرژی بر مبنای سیستمهای انتقال هیدرولیکی The applications of energy regeneration and conversion technologies based on hydraulic transmission systems: A review
Hydraulic transmission systems (HTSs) are widely used in various industrial fields. With the increase in research
on renewable energy and energy-saving technologies, energy regeneration and conversion (ERC) technologies
based on HTSs, including potential energy regeneration, braking energy regeneration, vibration energy acquisition
and power take-off (PTO), have attracted increasing attention. First, this review briefly explains the main
concepts of ERC technologies based on HTSs and applications; then their working principles are analysed. As the
main content of this review, the current status of ERC technologies based on HTSs in the application fields of
construction machinery, hydraulic vehicles, regenerative suspensions and wave energy converters (WECs) are
comprehensively analysed, compared and discussed. Finally, ERC technologies based on HTSs are prospected
from the aspects of hydraulic system component optimization, all-electric power system integration and potential
applications. This review is expected to provide readers with a comprehensive and clear understanding of
ERC technologies based on HTSs through a detailed overview of their application, which will provide an important
reference for further research and potential applications in this field.
دانلود مقاله تئوری لایه مرزی:یک پارادوکس قرن بیستم؟ LAMINAR BOUNDARY-LAYER THEORY: A 20TH CENTURY PARADOX?
Boundary-layer theory is crucial in understanding why certain phenomena
occur. We start by reviewing steady and unsteady separation from
the viewpoint of classical non-interactive boundary-layer theory. Next,
interactive boundary-layer theory is introduced in the context of unsteady
separation. This discussion leads onto a consideration of large-
Reynolds-number asymptotic instability theory. We emphasise that a
key aspect of boundary-layer theory is the development of singularities
in solutions of the governing equations. This feature, when combined
with the pervasiveness of instabilities, often forces smaller and smaller
scales to be considered. Such a cascade of scales can limit the quantitative
usefulness of solutions. We also note that classical boundarylayer
theory may not always be the large-Reynolds-number limit of the
Navier-Stokes equations. This is because of the possible ampli cation of
short-scale modes, which are initially exponentially small, by a Rayleigh
instability mechanism.
دانلود مقاله مروری بر فناوری روتور موجی و کاربردهای آن A Review of Wave Rotor Technology and Its Applications
The objective of this paper is to provide a succinct review of past and current research in
developing wave rotor technology. This technology has shown unique capabilities to
enhance the performance and operating characteristics of a variety of engines and machinery
utilizing thermodynamic cycles. Although there have been a variety of applications
in the past, this technology is not yet widely used and is barely known to engineers.
Here, an attempt is made to summarize both the previously reported work in the literature
and ongoing efforts around the world. The paper covers a wide range of wave rotor
applications including the early attempts to use wave rotors, its successful commercialization
as superchargers for car engines, research on gas turbine topping, and other
developments. The review also pays close attention to more recent efforts: utilization of
such devices in pressure-gain combustors, ultra-micro gas turbines, and water refrigeration
systems, highlighting possible further efforts on this topic. Observations and lessons
learnt from experimental studies, numerical simulations, analytical approaches, and
other design and analysis tools are presented. DOI: 10.1115/1.2204628
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An Introduction to Turbulence Models Almost all fluid flow which we encounter in daily life is turbulent. Typical examples are flow around (as well as in) cars, aeroplanes and buildings.The boundary layers and the wakes around and after bluff bodies such as cars, aeroplanes and buildings are turbulent. Also the flow and combustion in engines,…...
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Turbulence Models and TheirApplication to Complex FlowsR. H. NicholsUniversity of Alabama atBirmingham Some basic knowledge of turbulence and an understanding of how turbulence models are developed can help provide insight into choosing and applying these models to obtain reasonable engineering simulations of turbulent flows. This effort is directed at production users of Computational Fluid Dynamics…...