scholarly journals An Analysis of the Temperature Profiles of Some Antarctic Lakes

2021 ◽  
Author(s):  
◽  
T. G. L. Shirtcliffe
Keyword(s):  
Heat Source ◽  
Temperature Profile ◽  
Fresh Water ◽  
Solute Concentration ◽  
Temperature Profiles ◽  
Antarctic Lakes ◽  
Taylor Valley ◽  
Victoria Land ◽  
Brine Pools

<p>The temperature profiles of certain lakes in Taylor Valley, Victoria Land, Antarctica, are shown to be consistent with the hypothesis that these lakes were formerly cold brine pools; that their levels were raised by the addition of fresh water; and that they have since been heated principally by the absorption of sunlight. The temperature profile of a lake in Wright Valley, Victoria Land, is shown to be consistent with the hypothesis that this lake was formerly warm and stable, as are those Taylor Valley lakes which were analysed; that the addition of a further large quantity of fresh water caused instability and limited convection; and that the heat source is again absorbed sunlight. The study of this lake requires an understanding of convection in the presence of a gradient of solute concentration. A survey of existing knowledge of this type of convection shows that it is inadequate for the task. Experiments which provide the necessary information are described.</p>

scholarly journals An Analysis of the Temperature Profiles of Some Antarctic Lakes

2021 ◽  
Author(s):  
◽  
T. G. L. Shirtcliffe
Keyword(s):  
Heat Source ◽  
Temperature Profile ◽  
Fresh Water ◽  
Solute Concentration ◽  
Temperature Profiles ◽  
Antarctic Lakes ◽  
Taylor Valley ◽  
Victoria Land ◽  
Brine Pools

<p>The temperature profiles of certain lakes in Taylor Valley, Victoria Land, Antarctica, are shown to be consistent with the hypothesis that these lakes were formerly cold brine pools; that their levels were raised by the addition of fresh water; and that they have since been heated principally by the absorption of sunlight. The temperature profile of a lake in Wright Valley, Victoria Land, is shown to be consistent with the hypothesis that this lake was formerly warm and stable, as are those Taylor Valley lakes which were analysed; that the addition of a further large quantity of fresh water caused instability and limited convection; and that the heat source is again absorbed sunlight. The study of this lake requires an understanding of convection in the presence of a gradient of solute concentration. A survey of existing knowledge of this type of convection shows that it is inadequate for the task. Experiments which provide the necessary information are described.</p>

scholarly journals PROFIL SALINITAS DAN SUHU DI TELUK MANADO PADA HARI-HARI HUJAN DAN TIDAK HUJAN

2012 ◽  
Vol 8 (3) ◽  
pp. 95
Author(s):  
Patrice NI Kalangi ◽  
Kawilarang WA Masengi ◽  
Masamitsu Iwata ◽  
Fransisco PT Pangalila ◽  
Ixchel F Mandagi
Keyword(s):  
Surface Layer ◽  
Temperature Profile ◽  
Layer Thickness ◽  
Fresh Water ◽  
Water Layer ◽  
Temperature Measurements ◽  
Temperature Profiles ◽  
Vertical Profiles ◽  
Surface Salinity ◽  
Rainy Days

Pengukuran salinitas dan suhu perairan dilakukan pada hari-hari hujan dan tidak hujan di dua tempat di perairan Teluk Manado, yang memiliki lima sungai utama di pinggirannya, untuk menyelidiki profil vertikal dari salinitas dan suhu, serta ketebalan air tawar. Profil salinitas dan suhu perairan pada hari yang sama di kedua tempat adalah mirip. Pada hari-hari hujan, salinitas rata-rata lapisan permukaan perairan adalah 33,9 lebih rendah 0,3 dibandingkan pada hari-hari tidak hujan. Salinitas permukaan ini setara dengan ketebalan lapisan air tawar sebesar 0,45 m. di lapisan permukaan, profil suhu cukup mirip. Akan tetapi, pada lapisan yang lebih dalam, suhu berosilasi pada fase yang berbeda dengan bertambahnya kedalaman. Kata kunci: ketebalan lapisan air tawar, termoklin, Bunaken.   Salinity and temperature measurements were carried out on rainy days and non rainy days in two locations in Manado Bay, which is the outlet of fresh water masses from five main rivers, to investigate vertical profiles of salinity and temperature, and the thickness of the fresh water layer. Same day salinity and temperature profiles in both places is similar. On rainy days, the average salinity in the surface layer was 33.9, 0.3 lower than that of non rainy days. The surface salinity is equivalent to the thickness of the freshwater layer thickness of 0.45 m. In the surface layer, the temperature profile is quite similar. However, in the deeper layers, the temperature oscillates at different phases according to the increasing depths. Keywords: freshwater thickness, thermocline, Bunaken.

scholarly journals Analysis of hyperbolic Pennes bioheat equation in perfused homogeneous biological tissue subject to the instantaneous moving heat source

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Ali Kabiri ◽  
Mohammad Reza Talaee
Keyword(s):  
Heat Source ◽  
Closed Form ◽  
Method Comparison ◽  
Closed Form Solution ◽  
Form Solution ◽  
Temperature Profiles ◽  
Moving Heat Source ◽  
Bioheat Equation ◽  
Perfusion Rate

AbstractThe one-dimensional hyperbolic Pennes bioheat equation under instantaneous moving heat source is solved analytically based on the Eigenvalue method. Comparison with results of in vivo experiments performed earlier by other authors shows the excellent prediction of the presented closed-form solution. We present three examples for calculating the Arrhenius equation to predict the tissue thermal damage analysis with our solution, i.e., characteristics of skin, liver, and kidney are modeled by using their thermophysical properties. Furthermore, the effects of moving velocity and perfusion rate on temperature profiles and thermal tissue damage are investigated. Results illustrate that the perfusion rate plays the cooling role in the heating source moving path. Also, increasing the moving velocity leads to a decrease in absorbed heat and temperature profiles. The closed-form analytical solution could be applied to verify the numerical heating model and optimize surgery planning parameters.

Analytical Formulation for the Temperature Profile by Duhamel’s Theorem in Bodies Subjected to an Oscillatory Heat Source

2005 ◽  
Vol 129 (2) ◽  
pp. 236-240 ◽  
Author(s):  
Jun Wen ◽  
M. M. Khonsari
Keyword(s):  
Finite Element Method ◽  
Heat Flux ◽  
Heat Source ◽  
Temperature Profile ◽  
Rectangular Domain ◽  
Temperature Fields ◽  
Heat Sources ◽  
Point Heat Source ◽  
Analytical Formulation ◽  
Analytical Technique

An analytical technique is presented for treating heat conduction problems involving a body experiencing oscillating heat flux on its boundary. The boundary heat flux is treated as a combination of many point heat sources, each of which emits heat intermittently based on the motion of the flux. The working function of the intermittent heat source with respect to time is evaluated by using the Fourier series and temperature profile of each point heat source is derived by using the Duhamel’s theorem. Finally, by superposition of the temperature fields over all the point heat sources, the temperature profile due to the original moving heat flux is determined. Prediction results and verification using finite element method are presented for an oscillatory heat flux in a rectangular domain.

scholarly journals A new method to derive middle atmospheric temperature profiles using a combination of Rayleigh lidar and O<sub>2</sub> airglow temperatures measurements

2012 ◽  
Vol 30 (1) ◽  
pp. 27-32 ◽  
Author(s):  
A. Taori ◽  
A. Jayaraman ◽  
K. Raghunath ◽  
V. Kamalakar
Keyword(s):  
Temperature Profile ◽  
Atmospheric Temperature ◽  
New Method ◽  
Temperature Profiles ◽  
Vertical Temperature ◽  
Lidar System ◽  
Mesospheric Temperature ◽  
Simultaneous Measurements ◽  
Rayleigh Lidar ◽  
First Time

Abstract. The vertical temperature profiles in a typical Rayleigh lidar system depends on the backscatter photon counts and the CIRA-86 model inputs. For the first time, we show that, by making simultaneous measurements of Rayleigh lidar and upper mesospheric O2 temperatures, the lidar capability can be enhanced to obtain mesospheric temperature profile up to about 95 km altitudes. The obtained results are compared with instantaneous space-borne SABER measurements for a validation.

INFLUENCE OF CALORIMETRIC MIXING ON THE TEMPERATURE PROFILE WHEN EVALUATING WORKING INTERVALS

2021 ◽  
Author(s):  
Марат Финатович Закиров ◽  
Айрат Шайхуллинович Рамазанов ◽  
Рим Абдуллович Валиуллин ◽  
Рамиль Фаизырович Шарафутдинов
Keyword(s):  
Temperature Profile ◽  
Temperature Profiles ◽  
Measured Temperature ◽  
Vertical Wells

В данной работе исследуется профиль термограммы в зависимости от производительности работающих интервалов вертикальной скважины. Установлено, что существуют уникальные профили температур в зависимости от проявления эффекта калориметрического смешивания. Полученные результаты могут быть использованы для анализа экспериментальных профилей температуры с целью выделения работающих интервалов. In this paper, the thermogram profile is studied depending on the performance of the working intervals of the vertical wells. It is established that there are unique temperature profiles depending on the manifestation of calorimetric mixing. The obtained results can be used to analyze measured temperature profiles in order to identify working intervals.

Osmoregulation in the Diamondback Terrapin, Malaclemys Terrapin Centrata

1967 ◽  
Vol 46 (1) ◽  
pp. 161-167 ◽  
Author(s):  
P. J. BENTLEY ◽  
W. L. BRETZ ◽  
KNUT SCHMIDT-NIELSEN
Keyword(s):  
Fresh Water ◽  
Solute Concentration ◽  
Diamondback Terrapin ◽  
Malaclemys Terrapin ◽  
Excess Sodium ◽  
Diamondback Terrapins ◽  
Do So

1. While in hypertonic environment diamondback terrapins (Malaclemys centrata) slowly lose water by osmosis through the integument and as urine through the kidney. 2. Small amounts of sodium are gained, probably largely as a result of diffusion through the integument rather than by drinking, and this sodium is principally excreted extrarenally. Nevertheless, the solute concentration in the blood of such turtles increases. 3. When returned to fresh water the animals rehydrate and excrete accumulated excess sodium. 4. In these ways they could undoubtedly survive for extended periods in the absence of fresh water, but it is not clear whether they could do so indefinitely.

Lattice Boltzmann modeling of convective flows in a large-scale cavity heated from below by two imposed temperature profiles

2019 ◽  
Vol 30 (5) ◽  
pp. 2759-2779
Author(s):  
Noureddine Abouricha ◽  
Mustapha El Alami ◽  
Khalid Souhar
Keyword(s):  
Nusselt Number ◽  
Temperature Profile ◽  
Lattice Boltzmann ◽  
Large Scale ◽  
Temperature Profiles ◽  
Control Parameters ◽  
Content Type ◽  
Convective Flows ◽  
Glass Door ◽  
Vertical Walls

Purpose The purpose of this paper is to model the convective flows in a room equipped by a glass door and a heated floor of length l = 0.8 × H and submitted to a sinusoidal temperature profile and mono alternative temperature profile. Design/methodology/approach The paper opts for a numerical study of convective flows in a large scale cavity using the Lattice Boltzmann Method (LBM) by considering a two dimensions (2D) square cavity of side H and filled by air (Pr = 0.71). All the vertical walls, the ceiling and the rest of the floor are thermally insulated, the hot portion of length l = 0.8×H is heated with two imposed temperature profiles of amplitude values 0.2 ≤  a  ≤ 0.6 and for two different periods ζ = ζ0 and ζ = 0.4×ζ0. One of the vertical walls has a cold portion θc = 0 that represents the glass door. Findings A systematic study of the flow structure and heat transfer is carried out considering principal control parameters: amplitude “a” and period ζ for Rayleigh number Ra = 108. Effects of these parameters on results are presented in terms of isotherms, streamlines, profiles of velocities, temperature in the cavity, global and local Nusselt number. It has been found that an increase in amplitude or period increases the amplitude of the temperature in the core of cavity. The Nusselt number increases when the amplitude “a” of the imposed temperature increases, but this later is not affected by variation of the period. Originality/value The authors used LBM to simulate the convective flows in a cavity at high Ra, heated from below by tow imposed temperature profiles. Indeed, they simulate a local equipped by a solar water heater (SWH). The floor is subjected to a periodic heating: Sinusoidal heating (Case 1) for which the temperature varies sinusoidally (SWH without a supplement), and mono alternation heating (Case 2), the temperature evolves like a redressed signal (SWH with a supplement). The considered method has been successfully validated and compared with the previous work. The study has been conducted using several control parameters such as the signal amplitude and period in the case of turbulent convection. This allowed us to obtain a considerable set of results that can be used for engineering.

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