scholarly journals Thermoregulatory responses of sindhi and guzerat heifers under shade in a tropical environment

2016 ◽  
Vol 37 (6) ◽  
pp. 4327 ◽  
Author(s):  
Vinícius De França Carvalho Fonsêca ◽  
Ebson Pereira Cândido ◽  
Severino Gonzaga Neto ◽  
Edilson Paes Saraiva ◽  
Dermeval Araújo Furtado ◽  
...  
Keyword(s):  
Heat Loss ◽  
Thermal Environment ◽  
Bos Indicus ◽  
Experimental Period ◽  
Environmental Data ◽  
Tropical Environment ◽  
Significant Difference ◽  
Globe Temperature ◽  
Latent Heat Loss ◽  
Cutaneous Evaporation

This study characterized the thermal environment and assessed the physiological aspects of acclimatization of Sindhi and Guzerat heifers in a tropical environment (Brazil) under shade. Eight Sindhi and eight Guzerat purebred heifers (Bos indicus) had their physiological traits measured twice a day (9:00 a.m. and 2:00 p.m.). Environmental data during the experimental period were collected at two-hour intervals between 5:00 a.m. and 5:00 p.m. The temperature-humidity (THI) and the black globe temperature-humidity (BGHI) indices were calculated, and surface temperature (St), respiratory rate (Rr), and rectal temperature (Rt) were collected, being used to estimate heat loss by cutaneous (Ec) and respiratory (Er) evaporation. In the warmer parts of the day (1:00 and 3:00 p.m.), the THI and BGHI reached values of 80.26 and 81.25, respectively. There was no significant difference in rectal temperatures between the breeds, but higher values were observed in the afternoon. Heat transfer by cutaneous evaporation reached 118.71±12.91 W.m-2 and 103.43±6.82 W.m-2 at 2:00 p.m. for the Sindhi and Guzerat heifers, respectively. Under these conditions (air temperature was between 29 and 30°C), 84% of the total latent heat loss in Sindhi and Guzerat heifers was represented by Ec. It can be concluded that Sindhi and Guzerat heifers can maintain homeothermy with minimal thermoregulatory effort under shade conditions in a tropical environment.

scholarly journals Latent heat loss of Holstein cows in a tropical environment: a prediction model

2008 ◽  
Vol 37 (10) ◽  
pp. 1837-1843 ◽  
Author(s):  
Alex Sandro Campos Maia ◽  
Roberto Gomes da Silva ◽  
Cintia Maria Battiston Loureiro
Keyword(s):  
Heat Loss ◽  
Latent Heat ◽  
Air Temperature ◽  
Holstein Cows ◽  
Tropical Region ◽  
Weight Class ◽  
Air Temperatures ◽  
Latent Heat Loss ◽  
Cutaneous Evaporation ◽  
Respiratory Evaporation

Nine lactating Holstein cows with average 526 ± 5 kg of BW, five predominantly black and four predominantly white, bred in a tropical region and managed in open pasture were observed to measure cutaneous and respiratory evaporation rates under different environmental conditions. Cows were separated in three weight class: 1 (<450 kg), 2 (450-500 kg) and 3 (>500 kg). Latent heat loss from cutaneous surface was measured using a ventilated capsule; evaporation in the respiratory system was measured using a facial mask. The results showed that heaviest cows (2 and 3 classes) presented the least evaporation rates. When air temperature increased from 10 to 36ºC the relative humidity decreased from 90 to 30%. In these conditions the heat loss by respiratory evaporation increased from 5 to 57 Wm-2, while the heat loss by cutaneous evaporation increased from 30 to 350 Wm-2. The results confirm that latent heat loss was the main way of thermal energy elimination under high air temperatures (>30ºC); cutaneous evaporation was the main mechanism of heat loss, responding for about 85% of the heat loss. A model was presented for the prediction of the latent heat loss that was based on physiological and environmental variables and could be used to estimate the contribution of evaporation to thermoregulation; a second, based on air temperature only, should be used to make a simple characterization of the evaporation process.

scholarly journals A Field Study on the Indoor Thermal Environment of the Airport Terminal in Tibet Plateau in Winter

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Jianglong Zhen ◽  
Jun Lu ◽  
Guangqin Huang ◽  
Liyue Zeng ◽  
Jianping Lin ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Thermal Environment ◽  
Vertical Direction ◽  
Outer Zone ◽  
Tibet Plateau ◽  
Indoor Thermal Environment ◽  
Airport Terminal ◽  
Globe Temperature ◽  
Environment Parameters ◽  
Radiant Floor Heating

In order to study the characteristics of indoor thermal environment in the airport terminal in Tibet Plateau with radiant floor heating in winter, a field measurement of the indoor thermal environment was conducted in Lhasa Gonggar Airport terminal 2. First, the unique climate characteristics in Tibet Plateau were analyzed through comparison of meteorological parameters in Beijing and Lahsa. The thermal environment in the terminal was divided into outer zone and inner zone as well as south zone and north zone. Thermal environment parameters including air temperature, black globe temperature, relative humidity in each zone, and inner surface temperature of envelope were measured and analyzed. Meanwhile, temperature and relative humidity in the vertical direction were measured. In addition, PMV and PPD were calculated for evaluating the thermal environment in the terminal. The findings can provide guidance for the design and regulation of thermal environment in terminals in Tibet Plateau in China.

scholarly journals Productive performance and parasitological control of kids supplemented with umbu fruits (Spondias tuberosa Arruda)

2016 ◽  
Vol 17 (3) ◽  
pp. 520-528
Author(s):  
Thiago Vinicius Costa NASCIMENTO ◽  
Daniel Maia NOGUEIRA ◽  
Nilton de Brito CAVALCANTE
Keyword(s):  
Weight Gain ◽  
Arid Zone ◽  
Experimental Period ◽  
Gastrointestinal Nematodes ◽  
Daily Weight Gain ◽  
Productive Performance ◽  
Buffel Grass ◽  
Significant Difference ◽  
Semi Arid Region ◽  
Semi Arid

Summary Native fruits from Caatinga vegetation can be an important alternative to improve the productive performance of kids in the semi-arid region of Brazil. This work aimed to evaluate the effect of supplementation with Umbuzeiro fruits in natura over the weight gain and anthelmintic control of kids kept in Buffel grass pasture in the semi-arid zone of Pernambuco, Brazil. Twenty-four castrated, crossbreed kids were allocated into three treatments: 1) Control (n = 8) fed exclusively with Buffel grass; 2) Umbu 1x (n = 8) fed with fruits once a week and 3) Umbu 3x (n = 8) fed with fruits for three times a week. The following parameters were evaluated: variation of body weight, faecal egg counts (FEC) and coproculture. Overall, the average consumption of Umbu fruits in natura was 1.48 kg/animal/day, which corresponded to 133.5 g daily dry matter intake (DMI/animal/day). There were no significant difference (P>0.05) for any parameters evaluated. During the experimental period, the overall daily weight gain was variable between 108.75 to 116.70 g/animal/day and the average FEC was 436 eggs. In the present study, the goat kids supplemented with fresh umbu fruits showed a good productive performance, however the supplementation with umbu did not control the infestation of gastrointestinal nematodes in kids.

scholarly journals Long-Term Cytotoxicity, pH and Dissolution Rate of AH Plus and MTA Fillapex

2016 ◽  
Vol 27 (4) ◽  
pp. 419-423 ◽  
Author(s):  
Emmanuel João Nogueira Leal da Silva ◽  
Thais Accorsi-Mendonça ◽  
Ana Carolina Pedrosa ◽  
José Mauro Granjeiro ◽  
Alexandre A. Zaia
Keyword(s):  
Dissolution Rate ◽  
Experimental Period ◽  
Cell Viability Assay ◽  
Time Points ◽  
Viability Assay ◽  
Significant Difference ◽  
High Dissolution Rate ◽  
Post Test ◽  
Ah Plus

Abstract The aim of the present study was to verify the long-term cytotoxic effects of the MTA Fillapex and to compare them with AH Plus. Dissolution rate and pH were also evaluated. Human osteoblast cells were incubated with elutes of fresh specimens from AH Plus and MTA Fillapex, and with elutes of the same specimens for 4 successive weeks. Elute's pH was evaluated at each time point. A multiparametric cell viability assay was performed. For dissolution rate, ISO methodology was used. The results were analyzed by one-way analysis of variance, complemented with the Tukey post-test (p<0.05). No significant difference was found among the materials when fresh mixed (p>0.05). After 1 week, AH Plus became non-cytotoxic on all three evaluated parameters. Conversely, MTA Fillapex remained severely and mildly cytotoxic over the entire experimental period (p<0.05). The dissolution rate of AH Plus was significantly lower than MTA Fillapex at all time points (p>0.05). The pH of AH Plus was significantly lower than MTA Fillapex at the second and third week (p<0.05). In the other tested time points no statistical difference was observed. In conclusion, MTA Fillapex remained cytotoxic after 4 weeks and its cytotoxicity may be related to the high dissolution rate of this material.

scholarly journals The Street Air Warming Phenomenon in a High-Rise Compact City

Atmosphere ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 402 ◽  
Author(s):  
Xiaoxue Wang ◽  
Yuguo Li ◽  
Xinyan Yang ◽  
Pak Chan ◽  
Janet Nichol ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Thermal Environment ◽  
Urban Climate ◽  
Pollutant Dispersion ◽  
Urban Morphology ◽  
Air Temperatures ◽  
Significant Difference ◽  
Sensitivity Studies ◽  
Weather Stations

The street thermal environment is important for thermal comfort, urban climate and pollutant dispersion. A 24-h vehicle traverse study was conducted over the Kowloon Peninsula of Hong Kong in summer, with each measurement period consisting of 2–3 full days. The data covered a total of 158 loops in 198 h along the route on sunny days. The measured data were averaged by three methods (direct average, FFT filter and interpolated by the piecewise cubic Hermite interpolation). The average street air temperatures were found to be 1–3 °C higher than those recorded at nearby fixed weather stations. The street warming phenomenon observed in the study has substantial implications as usually urban heat island (UHI) intensity is estimated from measurement at fixed weather stations, and therefore the UHI intensity in the built areas of the city may have been underestimated. This significant difference is of interest for studies on outdoor air temperature, thermal comfort, urban environment and pollutant dispersion. The differences were simulated by an improved one-dimensional temperature model (ZERO-CAT) using different urban morphology parameters. The model can correct the underestimation of street air temperature. Further sensitivity studies show that the building arrangement in the daytime and nighttime plays different roles for air temperature in the street. City designers can choose different parameters based on their purpose.

The Comparison of Aerodynamic Performance Data Acquired From Thermal Measurements and a Torquemeter on a Compressor Impeller

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Natalie R. Smith ◽  
Timothy C. Allison ◽  
Jason C. Wilkes ◽  
Christopher Clarke ◽  
Michael Cave
Keyword(s):  
Steady State ◽  
Heat Loss ◽  
Performance Metrics ◽  
Aerodynamic Performance ◽  
Performance Data ◽  
Testing Time ◽  
Southwest Research Institute ◽  
Significant Difference ◽  
Thermal Measurements ◽  
Isentropic Efficiency

Full-thermal heat-soak of machinery is vital for acquiring accurate aerodynamic performance data, but this process often requires significant testing time to allow all facility components to reach a steady-state temperature. Even still, there is the potential for heat loss in a well-insulated facility, and this can lead to inaccurate results. The implementation of a torquemeter to calculate performance metrics, such as isentropic efficiency, has two potential advantages: (1) the method is not susceptible to effects due to thermal heat loss in the facility, and (2) a torquemeter directly measures actual torque, and thus work, input, which eliminates the need to fully heat-soak to measure the actual enthalpy rise of the gas. This paper presents a comparison of aerodynamic performance metrics calculated both from data acquired with thermal measurements as well as from a torquemeter. These tests were conducted over five speedlines for a shrouded impeller in the Southwest Research Institute Single Stage Test Rig facility. Isentropic efficiency calculated from the torquemeter was approximately 1–2 efficiency points lower than the isentropic efficiency based on thermal measurements. This corresponds to approximately 0.5–1 °C in heat loss in the discharge collector and piping. Furthermore, observations from three full-thermal heat-soak points indicate the significant difference in time required to reach steady-state performance within measurement uncertainty tolerances between the torque-based and thermal-based methods. This comparison, while largely suspected, has not yet been studied in previous publications.

Reproductive performance of Shorthorn and Brahman crossbred cows in the dry tropics of north Queensland

1979 ◽  
Vol 19 (98) ◽  
pp. 276 ◽  
Author(s):  
RG Holroyd ◽  
PK O'Rourke ◽  
PJ Allan
Keyword(s):  
Reproductive Performance ◽  
Experimental Period ◽  
Ovarian Activity ◽  
Gestation Length ◽  
Variable Effect ◽  
Crossbred Cows ◽  
Lactating Cows ◽  
Dry Tropics ◽  
Significant Difference ◽  
Conception Rates

A study was made (1 970 to 1973) of the reproductive performance of Shorthorn and Brahman crossbred cows grazing pasture in the dry tropics of north Queensland. Breed had a variable effect on the conception rates of lactating cows, with Brahman crossbreds having significantly higher (P < 0.05) conception rates in the first year. The two breeds had similar conception rates in the following year. In the third year, overall conception rates of both breeds were reduced due to a prolonged dry season, with Shorthorn cows having significantly higher (P < 0.01) conception rates than Brahman cows. However, during this dry period, twice as many Shorthorn cows required survival feeding as did Brahman cows. Calving rates followed conception rates closely, prenatal loss in each breed being low. In all years, Shorthorns had significantly earlier (P < 0.05) calving dates than Brahmans. The interval from calving to first recorded ovarian activity was significantly longer (P < 0.05) in Brahman cross than in Shorthorn cows in only one of the three years. There was no significant difference between breeds for the interval from first recorded ovarian activity to conception, but this interval decreased with increasing age of the cow. Breed had a variable effect on gestation length. Brahman cows were generally heavier each year in April and in better condition throughout the experimental period than Shorthorn cows.

scholarly journals Profile of cortisol, glycaemia, and blood parameters of American Bullfrog tadpoles Lithobates catesbeianus exposed to density and hypoxia stressors

2012 ◽  
Vol 32 (suppl 1) ◽  
pp. 91-98 ◽  
Author(s):  
Patricia C. Teixeira ◽  
Danielle C. Dias ◽  
Guilherme C. Rocha ◽  
Antônio M. Antonucci ◽  
Fernanda M. França ◽  
...  
Keyword(s):  
Blood Cells ◽  
White Blood Cells ◽  
Experimental Period ◽  
Blood Parameters ◽  
Air Exposure ◽  
Physiological Profile ◽  
Lithobates Catesbeianus ◽  
American Bullfrog ◽  
Physiological Alterations ◽  
Significant Difference

The aim of this study was to evaluate alterations to the physiological profile (cortisol, glycaemia, and blood parameters) of Lithobates catesbeianus caused by the stressors density and hypoxia. The organisms were in the prometamorphosis stage and exposed to different tadpole densities: 1 tadpole/L (T1), 5 tadpoles/L (T2), and 10 tadpoles/L (T3) for 12 days. The blood was collected through the rupture of the caudal blood vessel and collected under normoxia (immediate collection) and hypoxia (after 15 minutes of air exposure) conditions. Cortisol levels rose on the fourth and eighth days of treatment and returned to basal levels by the end of the experiment. The stressor mechanisms tested did not affect glycaemia. White blood cells (total number of lymphocytes, neutrophils, and eosinophils) showed a significant difference at the twelfth day of the experiment when compared with the start of the experiment. We concluded that, under controlled conditions, a density of up to 10 tadpoles/L and air exposure for 15 minutes did not cause harmful physiological alterations during the experimental period. The answer to these stressors maybe was in another hormonal level (corticosterone).

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