Regimes of stabilization of the flow of anomalous thermoviscous liquid depending on the heat exchange

2016 ◽  
Vol 11 (2) ◽  
pp. 272-277
Author(s):  
V.N. Kireev ◽  
S.F. Urmancheev
Keyword(s):  
Numerical Modeling ◽  
Heat Exchange ◽  
Incompressible Fluid ◽  
Convective Heat Exchange ◽  
The Third ◽  
Nusselt Numbers ◽  
Flow Stabilization ◽  
Different Types ◽  
Exchange Intensity ◽  
Unsteady Processes

In the paper the results of numerical modeling of the flow of an incompressible fluid with a non-monotonic dependence of the viscosity on the temperature in a channel are presented. On the channel’s walls the heat exchange is specified that are written mathematically in the form of the boundary conditions of the third kind on the basis of the Newton– Richman convective heat exchange law. The regimes of flow stabilization in the channel depending on the Nusselt numbers have been studied. Four different types of unsteady processes are discovered and it has been shown that they are determined by the different heat exchange intensity.

Laminar and Turbulent Natural Convection Simulation with Radiation in Enclosure

2016 ◽  
Vol 818 ◽  
pp. 3-11
Author(s):  
M. Hussen Hasanen ◽  
Hussein J. Akeiber
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Temperature Distribution ◽  
Convective Heat ◽  
Convective Heat Exchange ◽  
Turbulent Natural Convection ◽  
Heating Efficiency ◽  
Partial Heating ◽  
Different Types ◽  
Floor Heating

Several features of heat transfer on enclosing surfaces are discussed including temperature distributions in a room heated by a floor heater. Numerical analyses on radiative and convective heat transfer were carried out against several partial floor heating. Partial floor heating produces different types of temperature distribution between the heated and non-heated places, which is a remarkable characteristics found out in this study. In the heated places, the temperature distribution is almost the same as that of typical floor heating. However, in the non-heated places, air temperature differs by 6 °C (3.6 °Difference) between a point near the floor surface and a point well above that. Heating efficiency of partial heating slightly depends on the set place as well as its Area. Moreover, convective heat exchange constitutes approximately half of the total heat exchange

Topoi in der Musik Béla Bartóks

2013 ◽  
Vol 54 (3) ◽  
pp. 289-299
Author(s):  
Jürgen Hunkemöller
Keyword(s):  
Bird Song ◽  
Musical Analysis ◽  
Piano Concerto ◽  
The Third ◽  
Different Types ◽  
Important Means

The recognition of topoi, i.e. traditional formulae, is an important means of musical analysis. To illustrate this, the paper discusses the types of the battaglia and the pastoral in Bach’s Cantata Halt im Gedächtnis Jesum Christ, and briefly enumerates different types of allusions to jazz in 20th-century compositions by Stravinsky, Milhaud, Blacher, Tippet, and Zimmermann. Then it raises the possibility of an analysis of topoi in Bartók’s music in four main categories. It considers Bartók’s musical quotations from Bach to Shostakovich; the chorale as special topos appearing in Mikrokosmos, in the Concerto for Orchestra, in the Adagio religioso of the Third Piano Concerto; the topos-like employment of the tritone; and finally the idea of a Bartókian Arcadia in the Finale of Music for Strings, and the integration of bird song in the Adagio religioso.

DYNAMIC AND THERMAL INTERFERENCE EFFECTS ON TWO NEIGHBOURING BUILDING MODELS

2019 ◽  
Vol 21 (5) ◽  
pp. 138-150
Author(s):  
S. V. Korobkov ◽  
A. I. Gnyrya ◽  
V. I. Terekhov
Keyword(s):  
Heat Exchange ◽  
Mutual Effect ◽  
Convective Heat Exchange ◽  
Physical Models ◽  
Interference Effects ◽  
Total Contribution ◽  
Heat Flows ◽  
Building Models ◽  
Number Of Factors ◽  
Thermal Interference

The paper considers the dynamic and thermal interference effects on two neighbouring building models in the form of square prisms arranged at a short distance from each other. It is shown how relative positions of the models affect the specific phenomena caused by the airflow interactions.The aim of this paper is to experimentally study the dynamic and thermal interference of a tandem of two building models in the form of square prisms depending on their relative position.The phenomenon of wind loads on buildings and structures has always attracted great interest among engineers and researchers. With the accumulation of knowledge and technical capabilities, the potential for likely ways to study wind flows and their impact on different objects increased. In recent years, the world science has accumulated an extensive knowledge base on wind impacts on objects of various shapes, such as prisms, pyramids, cylinders, etc. Studies are carried out for their mutual impact of several objects on changes in both the wind load and heat exchange. Their mutual effect on the air motion and turbulence is considered.There are two main areas in the field of the wind impact. The first impact is the force load on building, the second is the wind as a source of convective heat exchange. The object of this study is the interference parameters allowing to assess the influence on the field of pressure and heat recoil of disturbances evoked in front of the barriers.At the first stage, physical models help to study the pressure field on different facets and ratios of the local and medium heat exchange under the forced convection conditions. The next step is to jointly consider the wind (dynamic) load and heat flows, attempting to detect the total contribution to changes depending on the reciprocal model arrangement. All experiments are performed in the aerodynamic tube, at the TSUAB department. It is shown that the dynamic and thermal interference ratios vary greatly in two building models. At the same time, the thermal interference is very conservative compared to the dynamic. Using the interference parameters, it is easy to analyze the extreme pressure and the heat flow on the model surface depending on a large number of factors, including their arrangement.

scholarly journals Preliminary Study on Gold Recovery from High Grade E-Waste by Thiourea Leaching and Electrowinning

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 235
Author(s):  
Nicolò Maria Ippolito ◽  
Ionela Birloaga ◽  
Francesco Ferella ◽  
Marcello Centofanti ◽  
Francesco Vegliò
Keyword(s):  
Sulfuric Acid ◽  
Leach Solution ◽  
High Grade ◽  
Gold Dissolution ◽  
Plastic Part ◽  
The Third ◽  
Current Consumption ◽  
Different Types ◽  
Preliminary Study ◽  
A Current

The present paper is focused on the extraction of gold from high-grade e-waste, i.e., spent electronic connectors and plates, by leaching and electrowinning. These connectors are usually made up of an alloy covered by a layer of gold; sometimes, in some of them, a plastic part is also present. The applied leaching system consisted of an acid solution of diluted sulfuric acid (0.2 mol/L) with thiourea (20 g/L) as a reagent and ferric sulfate (21.8 g/L) as an oxidant. This system was applied on three different high-grade e-waste, namely: (1) Connectors with the partial gold-plated surface (Au concentration—1139 mg/kg); (2) different types of connectors with some of which with completely gold-plated surface (Au concentration—590 mg/kg); and (3) connectors and plates with the completely gold-plated surface (Au concentration—7900 mg/kg). Gold dissolution yields of 52, 94, and 49% were achieved from the first, second, and third samples, respectively. About 95% of Au recovery was achieved after 1.5 h of electrowinning at a current efficiency of only 4.06% and current consumption of 3.02 kWh/kg of Au from the leach solution of the third sample.

Sign in / Sign up

Export Citation Format

Share Document