scholarly journals Association between the Area of the Highest Flank Temperature and Concentrations of Reproductive Hormones during Pregnancy in Polish Konik Horses—A Preliminary Study

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1517
Author(s):  
Małgorzata Maśko ◽  
Łukasz Zdrojkowski ◽  
Małgorzata Wierzbicka ◽  
Małgorzata Domino
Keyword(s):  
Lateral Surface ◽  
Regional Blood Flow ◽  
Thermal Characteristics ◽  
Reproductive Hormones ◽  
Ambient Temperatures ◽  
Estrone Sulfate ◽  
Average Temperature ◽  
Pregnancy Status ◽  
Thermal Features ◽  
Preliminary Study

Determination of the pregnancy status is one of the most important factors for effective pregnancy management. Knowledge of the stage of pregnancy is important to interpret many of the reproductive hormones’ concentrations, including progesterone (P4), estrone sulfate (E1S), 17-ß estradiol (E2), and relaxin (REL). However, it is limited in wildlife or captive equids that cannot be handled. Reproductive hormones affect regional blood flow, the proliferation of tissues, and local metabolism intensity. Therefore, this preliminary study aimed to assess changes in thermal features of the abdomen lateral surface and concentrations of reproductive hormones in Polish native pregnant mares. The study was carried out on 14 non-pregnant and 26 pregnant Polish Konik mares during eleven months of pregnancy. Infrared thermography was conducted to image the lateral surface of mares' abdomen (Px1) and flank area (Px2); P4, E1S, E2, and REL concentrations in serum were also determined. The evidence of the association between the area with the highest temperatures (Area of Tmax) and serum concentrations of P4 (the slope = 1.373; p = 0.9245) and REL (the slope = 1.342; p = 0.4324) were noted dependent across months of pregnancy. Measures of superficial body temperatures were found to change monthly, similarly to ambient temperatures, with no evidence of coincidence with changes in reproductive hormone concentrations. Individual thermal characteristics of the lateral surface of the abdomen differed between pregnant and non-pregnant mares in other periods. Differences in maximal and average temperature and Area of Tmax were observed from the sixth month of pregnancy, and those in minimal temperature were observed from the eighth month.

scholarly journals Technical note: Fourier approach for estimating the thermal attributes of streams

2016 ◽  
Vol 20 (8) ◽  
pp. 3411-3418 ◽  
Author(s):  
Masahiro Ryo ◽  
Marie Leys ◽  
Christopher T. Robinson
Keyword(s):  
Fourier Analysis ◽  
Thermal Characteristics ◽  
Stream Temperature ◽  
Technical Note ◽  
Swiss Alps ◽  
Diel Periodicity ◽  
Seasonal Periodicity ◽  
Average Temperature ◽  
Poor Site ◽  
Periodic Components

Abstract. Temperature models that directly predict ecologically important thermal attributes across spatiotemporal scales are still poorly developed. This study developed an analytical method based on Fourier analysis to estimate seasonal and diel periodicities, as well as irregularities in stream temperature, at data-poor sites. The method extrapolates thermal attributes from highly resolved temperature data at a reference site to the data-poor sites on the assumption of spatial autocorrelation. We first quantified the thermal attributes of a glacier-fed stream in the Swiss Alps using 2 years of hourly recorded temperature. Our approach decomposed stream temperature into its average temperature of 3.8 °C, a diel periodicity of 4.9 °C, seasonal periodicity spanning 7.5 °C, and the remaining irregularity (variance) with an average of 0.0 °C but spanning 9.7 °C. These attributes were used to estimate thermal characteristics at upstream sites where temperatures were measured monthly, and we found that a diel periodicity and the variance strongly contributed to the variability at the sites. We evaluated the performance of our predictive mechanism and found that our approach can reasonably estimate periodic components and extremes. We could also estimate the variability in irregularity, which cannot be represented by other techniques that assume a linear relationship in temperature variabilities between sites. The results confirm that spatially extrapolating thermal attributes based on Fourier analysis can predict thermal characteristics at a data-poor site. The R scripts used in this study are available in the Supplement.

Numerical study of steady natural convection in a liquefied natural gas cylindrical storage tank equipped with baffles

2019 ◽  
Vol 234 (5) ◽  
pp. 709-721 ◽  
Author(s):  
Mohamed Haddar ◽  
Moez Hammami ◽  
Mounir Baccar
Keyword(s):  
Rayleigh Number ◽  
Natural Gas ◽  
Lateral Surface ◽  
Storage Tank ◽  
Cooling System ◽  
Numerical Study ◽  
Gas Storage ◽  
Liquefied Natural Gas ◽  
Natural Gas Storage ◽  
Average Temperature

In this paper, a study of cooling system for a liquefied natural gas storage tank is conducted. Our objective is to remedy the heat ingress to the liquefied natural gas from the environment using baffles toward limiting temperature elevation in the tank, and then the Boil-off Gas (BOG) formation. A specific code based on the finite volume method is developed to supply a fine knowledge of the hydrodynamic and thermal liquefied natural gas characteristics in the cylindrical tank heated from bottom and lateral surfaces. The effect of the number, position and dimension of baffles, on the flow structure and thermal behavior, has been analyzed. According to our simulation results, the baffles should be placed at the top of tank nearby the lateral wall as the liquefied natural gas dimensionless average temperature can be reduced by 36%. The installation of four rectangular baffles, equally spaced around the perimeter of the tank, gives better homogenization of the temperature field and decreases the average temperature by about 44% in order to limit BOG formation. Finally, two correlations of the Nusselt number are established for the flat rectangular baffle plates and the lateral surface of the cylindrical liquefied natural gas storage tank as a function of the Rayleigh number, as well as the baffle number. Scaling of these correlations with the Rayleigh number gives exponents of 0.25 and 0.18 for lateral surface and baffle, respectively, which are in good agreement with literature.

Analysis on Thermal Characteristics of Phase Change Roof and Insulation Roof

2011 ◽  
Vol 99-100 ◽  
pp. 1128-1136
Author(s):  
Guo Zhong Wu ◽  
Yan Zhao ◽  
Jing Wang ◽  
Dong Li
Keyword(s):  
Phase Transition ◽  
Heat Flux ◽  
Transition Temperature ◽  
Phase Change ◽  
Thermal Characteristics ◽  
Bottom Surface ◽  
Average Heat ◽  
Average Temperature ◽  
Steady Stage ◽  
Change Material

The two-dimensional unsteady heat transfer models of common roof, insulation roof and phase change roof were established, and the thermal characteristics of common roof, insulation roof and phase change roof with different phase transition temperature were analyzed based on CFD software, the hourly average temperature distribution of their top and bottom surface from initial stage to steady stage and 24-hour hourly average temperature distribution of and average heat flux of bottom surface in steady stage were also attained. The results show that, under air conditioning constant temperature mode, addition of insulation material and phase change material observably improve the heat insulation performance of roof structures, the cooling and energy saving effect of roof more obviously, the attenuation multiple and delay time of roof more obviously, and make the hourly distribution of average temperature and average heat flux of roof bottom surface much gentler. In addition, choosing a phase change material with suitable phase transition temperature according to outside air comprehensive temperature is the key to utilize its latent heat more effectively.

Loss of integrative control of peripheral circulation during desynchronized sleep

1991 ◽  
Vol 261 (2) ◽  
pp. R373-R377 ◽  
Author(s):  
T. Cianci ◽  
G. Zoccoli ◽  
P. Lenzi ◽  
C. Franzini
Keyword(s):  
Blood Flow ◽  
Regional Blood Flow ◽  
Sleep Stage ◽  
Peripheral Circulation ◽  
Arteriovenous Anastomoses ◽  
Nervous Regulation ◽  
Radioactive Microspheres ◽  
Ambient Temperatures ◽  
Circulation Patterns ◽  
Vasomotor Activity

Regional blood flow (BF) changes during sleep were measured in rabbits at low, neutral, and high ambient temperatures (Ta) with radioactive microspheres. At both low and high Ta, peripheral vasomotor changes at the onset of desynchronized sleep (DS) were incompatible with thermoregulatory homeostasis. At low Ta, BF decreased in muscle (with the disappearance of shivering), whereas it increased in the arteriovenous anastomoses (AVA) and in the splanchnic bed. At high Ta, BF decreased in muscle (with the disappearance of panting) and in the AVA, whereas it increased in the splanchnic bed. An impaired central nervous regulation underlies the disruption of peripheral circulation patterns in this sleep stage. The lack of adaptive vasomotor adjustments in DS, which has little consequence in normal conditions, may become relevant in cardiovascular pathophysiology when BF redistribution through increased neurogenic vasomotor activity becomes a major compensating mechanism.

Thermal Management of Electronic Chips in a Channel Using Input Power to Control Flow Velocity

2009 ◽  
Vol 131 (1) ◽  
Author(s):  
Esam M. Alawadhi
Keyword(s):  
Steady State ◽  
Pressure Drop ◽  
Thermal Management ◽  
Heat Generation ◽  
Electronic Device ◽  
Thermal Characteristics ◽  
Input Power ◽  
Control Flow ◽  
Steady State Condition ◽  
Average Temperature

In this research, thermal management of an electronic device using the input power is investigated numerically using the finite element method. The considered geometry consists of a horizontal channel with three volumetrically heated chips mounted on the bottom wall of the channel. The magnitude of the channel’s inlet velocity is varied with the variation of heat generation in the chips. The thermal characteristics of the system are presented, and compared with thermal characteristics of a system at a steady state condition. The effect of the Reynolds number and the oscillating period of the heat generation on the chips’ average temperature and Nusselt number is presented. The pressure drop in the channel is also calculated. The results indicated that the transient operating condition causes temperature to be higher than steady state by more than 45%, and difference between the transient and steady operations is reduced if the frequency is high. However, flow frequency has nearly no effect on the pressure drop in the channel.

Seasonal variation in the reproductive hormones of male goats

1992 ◽  
Vol 126 (3) ◽  
pp. 271-275 ◽  
Author(s):  
Francesca Grasselli ◽  
Rosella Gaiani ◽  
Carlo Tamanini
Keyword(s):  
Ambient Temperature ◽  
Plasma Levels ◽  
Stress Condition ◽  
Acute Stress ◽  
Plasma Concentrations ◽  
Early Spring ◽  
Reproductive Hormones ◽  
Estrone Sulfate ◽  
Lh Release ◽  
Plasma Prl

The aim of this work was to study the circannual plasma profiles of LH, PRL, testosterone (T) and estrone sulfate (EIS) in different periods of the year and to characterize the possible variations in LH and PRL release patterns. We also tried to verify a possible relationship between plasma PRL fluctuations and ambient temperature, as well as the influence of an acute stress condition on levels of plasma PRL. Six adult male goats of the Ionica and Alpine breed reared in Southern Italy (40°N lat.) were subjected to frequent samplings (every 1 5 min for 6 h) once a month for a whole year. The blood samples were assayed for plasma concentrations of EIS, LH and PRL by radioimmunoassay, and for T by enzyme-immunoassay. The ambient temperature was recorded on each day of bleeding. Sex steroids and PRL showed marked circannual variations, with the highest levels during the summer (July) and the lowest during the winter-early spring (March). The concentrations of plasma LH did not indicate significant seasonal variations. A positive relationship was observed between plasma levels of PRL and EIS and ambient temperature. The patterns of LH release seemed to change depending on season, but this was not an obvious and common feature in all bucks. The hormone concentrations for plasma PRL profiles seemed to be influenced by an acute stress condition (associated with cannula insertion and handling procedures), with the variations more marked when the plasma levels of PRL were low.

scholarly journals Effect of temperature on the life cycle of Acanthagrion Selys, 1876 (Insecta: Coenagrionidae) under artificial conditions

2015 ◽  
Vol 15 (2) ◽  
Author(s):  
João Ânderson Fulan ◽  
Marcelo Rodrigues dos Anjos ◽  
Nadja Gomes Machado
Keyword(s):  
Life Cycle ◽  
Water Temperature ◽  
Single Species ◽  
Effect Of Temperature ◽  
Southern State ◽  
Ambient Temperatures ◽  
Average Temperature

The goal of this study was to investigate the effect of temperature on the life cycle of Acanthagrion nymphs sampled in a stream in the southern state of Amazonas. Altogether, 50 nymphs (10 in each of the five treatments) with ambient temperatures of 16, 20, 24, 28 and 32°C and water temperatures of 18, 22, 26, 30 and 34oC, respectively, were used. The only treatment that had a hatching adult was at a temperature of 28oC, identified in a single species, Acanthagrion apicale. In all other treatments (16, 20, 24 and 32oC), all nymphs died, respectively 1, 1, 3 and 2 days. We conclude from the results of this study that controlling water temperature near 28°C was the most efficient for obtaining adult A. apicale, and that this temperature was close to the average temperature where the nymphs were sampled, indicating that the control of this variable in artificial conditions is extremely important to obtain adults from nymphs.

scholarly journals Forming egg shape index as influenced by ambient temperatures and age of hens

2006 ◽  
Vol 22 (1-2) ◽  
pp. 119-125 ◽  
Author(s):  
Nedeljka Nikolova ◽  
Dragoslav Kocevski
Keyword(s):  
Winter Season ◽  
Shape Index ◽  
Poultry Farm ◽  
High Significance ◽  
Ambient Temperatures ◽  
Average Temperature ◽  
Autumn Season ◽  
Average Shape ◽  
Index Value ◽  
Autumn And Winter

The effects of ambient temperatures and hen?s age were investigated on poultry farm on the south of R. Macedonia, where annually average temperature was higher then other regions. In nine-month period of testing were included summer, autumn and winter season. Two groups of hens (ISA-BROWN) were used; the first one was younger (to 45-week age) and second was older (above 45-weeks). Once a month, about 100 eggs were examined, so the final number of tested eggs was 877. Average shape index was 75.19% for all eggs. High significance (p<0.01) showed both factors: age and season. Eggs from younger hens had index value of 76.16%, which is pointed on eggs with rounded shape, while older hen's eggs had index 74.20% with elongated shape. In summer and autumn season, most of eggs were with elongated shape while rounded shape had eggs in winter season.

PCB thermal reliability characteristics analysis under ambient temperature

2020 ◽  
Vol 20 (3) ◽  
pp. 853-858
Author(s):  
Hailong Huang ◽  
Yi Wan ◽  
Kai Zhou
Keyword(s):  
Flow Analysis ◽  
Thermal Characteristics ◽  
Thermal Design ◽  
Junction Temperature ◽  
Electrical Transmission ◽  
Thermal Reliability ◽  
Ambient Temperatures ◽  
Reliability Characteristics ◽  
Characteristics Analysis ◽  
Volume Method

PCB is an important component for electronic devices – Mechanical connections and electrical transmission, thermal failure is its main failure mode, the heat flow analysis and thermal design is the basis and premise to improve thermal characteristics of PCBs. In this paper, based on the principles of fluid mechanics, using the finite volume method, the thermal characteristics of the PCB is modeled, and we obtain the maximum junction temperature of the PCB, PCB’s thermal distribution and effect of different ambient temperatures on the PCB thermal characteristics. The study provides a theoretical basis for the PCB thermal design.

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