• Title/Summary/Keyword: Hot Ambient Temperature

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Performance and Heat Tolerance of Broilers as Affected by Genotype and High Ambient Temperature

  • Al-Batshan, H.A.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.10
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    • pp.1502-1506
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    • 2002
  • This experiment was conducted to evaluate the effects of the broiler's genotype ($G_t$) and ambient temperature ($T_a$) on performance and core body temperature ($T_core$) of broiler chicks. A factorial arrangement of two $G_t$ (Hubbard and ISA J57 chicks) and two $T_a$ (moderate, $23{\pm}0.5^{\circ}C$ and hot, $33{\pm}0.5^{\circ}C$) were used in this study. Performance data (body weight gain, feed intake and feed:gain ratio) were determined weekly for six weeks. Chicks' $T_core$ was measured using a biotelemetric system between Weeks five and six. Results showed that body weight gain and feed intake were significantly high, and feed:gain ratio was significantly low for Hubbard chicks compared to those of ISA J57 chicks. High $T_a$ significantly reduced weight gain and feed intake. Furthermore, the reduction in body weight gain and feed intake under the hot $T_a$ was more pronounced for Hubbard chicks than those of the ISA J57 chicks resulting in significant $G_t$ by $T_a$ interaction. Chicks grown under moderate $T_a$ had significantly lower $T_core$ than those grown under hot $T_a$. The $T_core$ of the Hubbard chicks was significantly lower than that of the ISA J57 at the moderate $T_a$ while under the hot $T_a$, the magnitude of the change in $T_core$ was more pronounced in Hubbard chicks than that of ISA J57; this resulted in a significant $G_t$ by $T_a$ interaction. The results of this study indicate that chicks with higher potential for growth under thermo-neutral temperature are more susceptible to heat stress than chicks with lower potential for growth. This maybe due, at least in part, to their lower body $T_core$ under moderate temperature and to the lesser ability of these fast growing chicks to regulate their $T_core$ when exposed to heat stress, as was clearly shown on these birds' performance.

Hot Wire Wind Speed Sensor System Without Ambient Temperature Compensation (주변 온도보상이 필요 없는 열선식 풍속 센서 시스템)

  • Sung, Junkyu;Lee, Keunwoo;Jung, Hoekyung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.23 no.10
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    • pp.1188-1194
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    • 2019
  • Among the many ways to measure the flow of fluid the hot air wind speed sensor is a device for measuring the speed or temperature by heat transfer of a fluid. However, the hot wire wind speed sensor is sensitive to external environmental factors, and has a disadvantage of inaccuracy due to ambient temperature, humidity, and signal noise. In order to compensate for this disadvantage, advanced technology has been introduced by adding temperature compensation circuits, but it is expensive. In order to solve this problem, this paper studies the wind speed sensor that does not need temperature compensation. Heated wind speed sensors are very vulnerable to the ambient temperature, which is generated by electronic circuits, even among external environmental factors. in order to improve this, the auxiliary heating element is additionally installed in the heating element to control a constant temperature difference between the auxiliary heating element and the heating element.

The Effect of Ambient Air Condition on a Hot Steel Plate Cooled by Impinging Water Jet (주변공기조건이 충돌수분류에 의한 고온강판의 냉각에 미치는 영향 연구)

  • Lee, Pil-Jong;Choi, Hae-Won;Lee, Seung-Hong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.1
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    • pp.29-38
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    • 2000
  • It is observed that the cooling capacity of impinging water jet is affected by the seasonal conditions in steel manufacturing process with large scale. To confirm this phenomena, the cooling experiments of a hot steel plate by a laminar jet were conducted for two different initial ambient air temperature($10^{\circ}C$ and $40^{\circ}C$) in a closed chamber, and an inverse heat conduction method is applied for the quantitative comparison. It is found that the cooling capacity under $10^{\circ}C$ air temperature is lower than that under $40^{\circ}C$, as is the saturated water vapor is more easily observed, and the amount of total extracted heat in the case of $10^{\circ}C$ is smaller by nearly 15% than that of $40^{\circ}C$ case. From these results, it is thought that the quantity of water vapor, which could be absorbed until saturation, effects on the mechanism of boiling heat transfer.

The Effects of Hot Temperature on Impulsive Behaviors: The Role of Product Types as a Moderator

  • Ahn, Hee-Kyung
    • Asia Marketing Journal
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    • v.14 no.3
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    • pp.27-48
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    • 2012
  • Temperature and weather are all around us, quite literally. Furthermore, temperature and weather not only permeate our atmosphere, constantly affecting our visceral states of warmth and coldness, but they metaphorically permeate our language. People, products, and ideas can all be "hot" or "cold." Given this ubiquity, it is perhaps surprising that relatively little research has systematically examined the influence of temperature on choice and judgment. Temperature-related words such as "hot" and "cold" are often used to describe impulsive and calculated behaviors, respectively. These metaphoric connotations of thermal concepts raise the question as to whether temperature, psychological states and decision making are related to each other, and if so, how. The current research examines these questions and finds support for a relationship. Across one field study and one laboratory experiment, I demonstrate that both hot ambient room temperature (Spa) and hot temperature primes (words) trigger decision outcomes in line with the metaphoric association between hot temperature and impulsivity. In the field study, participants were recruited in hot (40-50 degrees Celsius) and cold (10 degrees Celsius) rooms at a spa. Participants were simply asked to indicate their willingness-to-pay (WTP) for three product categories (travel package, birthday dinner, and cell phone). The results showed that participants in the hot room in comparison to those in the cold room were willing to pay more for the same products. Next, I tested if our results would go beyond ambient temperature and would hold if I were to prime temperature concepts by using a different priming method (i.e., subliminal vs. supraliminal). In line with the previous findings in the spa, participants in the hot priming condition were more likely to choose the wrong answer for the bat and baseball question than those in the cold priming condition. In addition, product type (e.g., pleasure vs. necessity) can moderate the effect of hot temperature on impulsivity. Mood and arousal did not mediate participants' responses. My findings seem to suggest that the effects of temperature on decision outcomes can be attributed to metaphoric associations rather than incidental mood or arousal. The current research applies a novel perspective in understanding the relationship between temperature and judgment and decision making. Also, the results have practical implications for packaging, advertising, merchandising, and pricing of goods and services, as well as for public policy and awareness. One of the most natural implications of my findings would be that retailers would be better off carrying more impulse purchase items on hot days. Furthermore, point-of-purchase promotions encouraging impulse purchase is more likely to be effective in retail environments with higher temperature than with lower temperature. In addition, advertisements and product packages evoking hot temperature associations (e.g., beach, sunshine, summer) might lead consumers to pay higher price for the advertised product than those with cold temperature associations.

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Flexural-torsional buckling tests of cold-formed steel compression members at elevated temperatures

  • Heva, Yasintha Bandula;Mahendran, Mahen
    • Steel and Composite Structures
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    • v.14 no.3
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    • pp.205-227
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    • 2013
  • Current design standards do not provide adequate guidelines for the fire design of cold-formed steel compression members subject to flexural-torsional buckling. Eurocode 3 Part 1.2 (2005) recommends the same fire design guidelines for both hot-rolled and cold-formed steel compression members subject to flexural-torsional buckling although considerable behavioural differences exist between cold-formed and hot-rolled steel members. Past research has recommended the use of ambient temperature cold-formed steel design rules for the fire design of cold-formed steel compression members provided appropriately reduced mechanical properties are used at elevated temperatures. To assess the accuracy of flexural-torsional buckling design rules in both ambient temperature cold-formed steel design and fire design standards, an experimental study of slender cold-formed steel compression members was undertaken at both ambient and elevated temperatures. This paper presents the details of this experimental study, its results, and their comparison with the predictions from the current design rules. It was found that the current ambient temperature design rules are conservative while the fire design rules are overly conservative. Suitable recommendations have been made in relation to the currently available design rules for flexural-torsional buckling including methods of improvement. Most importantly, this paper has addressed the lack of experimental results for slender cold-formed steel columns at elevated temperatures.

EFFECTS OF WATERY VAPOR CONCENTRATION ON DROPLET EVAPORATION IN HOT ENVIRONMENT

  • Lee, M.J.;Kim, Y.W.;Ha, J.Y.;Chung, S.S.
    • International Journal of Automotive Technology
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    • v.2 no.3
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    • pp.109-115
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    • 2001
  • A study has been conducted to clarify the effect of watery vapor concentration in hot ambient on droplet evaporation. Droplets of water, ethanol, n-hexadecaneand n-heptane were used in this experimental study. Ambient conditions are fixed at 470 K in temperature, 0.1 MPa in pressure and 2 m/s in velocity of ambient air. Watery vapor concentration was changed 0%~40% by 10% by add water to air. To obtain the time histories of droplet diameter after exposed in ambient, a suspended droplet in hot and humid ambient stream was synchronized with a back flash light, and enlarged droplet images were taken by a CCD camera. The evaporation rate constant of water droplet decreases slightly with the vapor concentration because diffusion velocity reduction of droplet vapor occurs on the surface. The values of ethanol and n-heptane droplet actively increase by effect that water from condensation of vapor flows into the droplet. The evaporation rate constant of n-hexadecane which has higher boiling point than water increases within around 30% of the concentration.

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EFFECTS OF NICARBAZIN AND HOT TEMPERATURE ON EVAPORATIVE WATER LOSS, ACID-BASE BALANCE, BODY TEMPERATURE AND CARBON DIOXIDE EXHALATION IN ADULT ROOSTERS

  • Lee, B.D.;Lee, S.K.;Hyun, W.J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.7 no.1
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    • pp.97-101
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    • 1994
  • Two experiments were conducted to study the effect of ambient temperature and nicarbazin on SCWL adult roosters. In Experiment 1, the effects of nicarbazin supplementation (125 ppm) on the water metabolism, blood acid-base balance; and rectal temperature of 16 birds in normal ($21^{\circ}C$) and hot ($35-36^{\circ}C$) temperature were investigated. In Experiment 2, the evaporative water loss and $CO_2$ exhalation from 8 birds were measured individually with an open-circuit gravimetric respiration apparatus in normal ($21^{\circ}C$) and hot ($33.5-34^{\circ}C$) temperature. The amount of water intake and evaporative water loss increased in birds under heat stress (HS). Nicarbazin exacerbated these effect in hot temperature. Also, nicarbazin decreased the blood $pCO_2$ and increased pH of HS birds. The rectal temperature of birds increased in hot temperature, and nicarbazin worsened this effect. The evaporative water loss, measured directly with respiration apparatus (Experiment 2), was increased in hot temperature. HS decreased the amount of $CO_2$ exhalation. Nicarbazin did not exert ant effect on either of these measurements, probably due to the limited duration (2 h) of the trial. The decrease in $CO_2$ exhalation by HS birds could be explained by reduced metabolic rate, which helps homeothermy of birds in hot temperature.

Relation of Calcium Activity in Milk and Milk Production of Holstein Cows in Hot Season

  • Tanaka, Masahito;Suzuki, Tomoyuki;Kotb, Saber;Kamiya, Yuko
    • Asian-Australasian Journal of Animal Sciences
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    • v.24 no.10
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    • pp.1372-1376
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    • 2011
  • The content of Ca in milk exceeds the typical saturation level of Ca salts, which is necessary for neonate growth. This calcium is distributed between the casein micelles in the colloidal and aqueous phases. Information on the properties of calcium activity in the aqueous phase is limited compared with that on the properties of bound or sequestrated calcium. The objectives of this study were to evaluate the changes in calcium activity in fresh milk using an ion-selective electrode and to assess the relationship between calcium activity and milk production in hot season. Milk samples collected from 10 cows at the National Agricultural Research Center for Kyushu Okinawa Region in June to October (Min-Max: 7.2-$35.2^{\circ}C$, 24.3-100% RH) were analyzed on total calcium concentrations and calcium activity. We observed that the rectal temperature of the cows increased according to elevation of ambient temperature but that the pH of the collected milk ($6.61{\pm}0.01$ (Mean${\pm}$SEM)) was not significantly influenced by rectal and ambient temperature. Total calcium concentrations and calcium activity in fresh milk decreased in July (Min-Max: 21.1-$33.5^{\circ}C$, 48.9-100.0% RH) compared with the values after August (Min-Max: 18.1-$35.0^{\circ}C$, 26.5-96.2% RH) (p<0.05); however, there was no significant correlation between the two parameters. The ratio of calcium activity to total calcium concentration decreased after August compared with the values in June and July (p<0.05). The calcium activity in fresh milk was positively correlated with milk yield (r = 0.45, p<0.01) and negatively correlated with milk lactose content (r = -0.53, p<0.01). These results suggest that the calcium activity in milk could be affected by ambient temperature and might be associated with milking production in hot season.

Changes in the Aggressiveness and Fecundity of Hot Pepper Anthracnose Pathogen (Colletotricum acutatum) under Elevated CO2 and Temperature over 100 Infection Cycles

  • Koo, Tae-Hoon;Hong, Sung-Jun;Yun, Sung-Chul
    • The Plant Pathology Journal
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    • v.32 no.3
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    • pp.260-265
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    • 2016
  • We observed the changes in aggressiveness and fecundity of the anthracnose pathogen Colletotrichum acutatum on hot pepper, under the ambient and the twice-ambient treatments. Artificial infection was repeated over 100 cycles for ambient ($25^{\circ}C/400ppm$ $CO_2$) and twice-ambient ($30^{\circ}C/700ppm$ $CO_2$) growth chamber conditions, over 3 years. During repeated infection cycles (ICs) on green-pepper fruits, the aggressiveness (incidence [% of diseased fruits among 20 inoculated fruits] and severity [lesion length in mm] of infection) and fecundity (the average number of spores per five lesions) of the pathogen were measured in each cycle and compared between the ambient and twice-ambient treatments, and also between the early (ICs 31-50) and late (ICs 81-100) generations. In summary, the pathogen's aggressiveness and fecundity were significantly lower in the late generation. It is likely that aggressiveness and fecundity of C. acutatum may be reduced as global $CO_2$ and temperatures increase.

Rectal Temperature of Lactating Sows in a Tropical Humid Climate according to Breed, Parity and Season

  • Gourdine, J.L.;Bidanel, J.P.;Noblet, J.;Renaudeau, D.
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.6
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    • pp.832-841
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    • 2007
  • Rectal Temperature;Thermoregulation;Sows;Breed;The effects of season (hot vs. warm) in a tropical humid climate, parity (primiparous vs. multiparous) and breed (Creole: CR, Large White: LW) on rectal temperature (RT) were studied for a total of 222 lactations obtained in 85 sows (43 CR and 42 LW; 56 primiparous and 166 multiparous) over a 28-d lactation, between June 2002 and April 2005. Mean daily ambient temperature was higher during the hot season than during the warm season (26.0 vs. $24.1^{\circ}C$) and relative humidity was high and similar in both seasons (89% on average). At farrowing, BW was lower (172 vs. 233 kg) and backfat thickness was higher (37 vs. 21 mm) in CR than in LW sows (p<0.01). During the hot season, the reduction of average daily feed intake (ADFI) was more pronounced in LW than in CR sows (-920 vs. -480 g/d, p<0.05). Rectal temperature was higher at 1200 than at 0700hr, which coincides with the maximum and the minimum values of daily ambient temperature. The daily RT increased ($+0.9^{\circ}C$; p<0.01) between d -3 and d 7 (d 0: farrowing day), remained constant between d 7 and d 25 and decreased (p<0.01) thereafter (i.e. $-0.6^{\circ}C$ between d 25 and d 32). The average daily RT was significantly higher during the hot than during the warm season (38.9 vs. $38.6^{\circ}C$; p<0.01). It was not affected by breed, but the difference in RT between the hot and warm seasons was more pronounced in LW than in CR sows (+0.4 vs. $+0.2^{\circ}C$; p<0.05). Parity influenced the RT response; it was greater in primiparous than in multiparous sows (38.9 vs. $38.7^{\circ}C$; p<0.01). This study suggests that thermoregulatory responses to heat stress can differ between breeds and between parities.