人間と生活環境 vol.03

伝熱学つまみ喰い(2):物質移動を伴う伝熱

棚澤 一郎
棚澤 一郎

Heat Transfer in Too Short (2):
Heat Transfer Accompanied with Mass Transport

Ichiro TANASAWA
Department of Mechanical Systems Engineering,
Tokyo University of Agriculture and Technology

This is the second part of lecture courses entitled "Heat Transfer in Too Short." In the first part of this lecture published on Vol. 2, No. I of this Journal, the fundamentals of heat transfer are de-scribed. The contents of the first part are; 1. Temperature, and Heat Transfer, 2. Three Modes of Heat Transfer, 3. Heat Conduction, 4. Convective Heat Transfer, and 5. Concluding Remarks. This second part is devoted to heat transfer accompanied with transport of mass. Transport of mass is very important in the temperature regulation by perspiration from a human body exposed to a hot environment. The main contents are; Introduction, Definition of Concentration, Partial Pressure and Humidity, Fick's Law, Convective Mass Transfer, and Analogy between Mass Transfer and Heat Transfer
Key words: Iecture, heat tranfer, mass transfer

 本稿は、『伝熱学つまみ喰い』と題して本誌Vol.2, No.1に掲載された基礎講座の第2回目である。第1回目の目次は、1.温度・熱・伝熱、2.伝熱の三つのモード、3.熱伝導、4.対流伝熱、5.結び、であった。第2回目の本稿では、物質移動を伴う伝熱について解説している。物質移動は、高温環境下でのヒトの体温調節のメカニズムである発汗と関連して重要である。主な内容は、序論、濃度の定義、分圧と湿度、フィックの法則、対流物質伝達、物質伝達と熱伝達のアナロジーなどである。
キーワード 基礎講座、伝熱学、物質伝達
(J.Human and Living Environment), 3(1), 2/8, 1996
back

老若男女の温熱生理学(1)
─新生児期から小児期まで─

小林 徳雄
愛知医科大学第二生理学教室

Thernral Physiology of the Young and Old of Both Sexes:
-Part 1. Neonates, Infants and Children-

Tokuo OGAWA
Department of Physiology, Aichi Medical University

Update knowledge on thermoregulatory functions and thermal adaptability of the young and old of both sexes is surveyed. In part 1, that from birth to preadolescence is discussed. Newborns are characterized by a relatively large surface area, thin skin and subcutaneous fat, and insufficient thermo regulatory responses, making their thermoneutral zone warmer and narrower, compared to adults. On the other hand, well-developed brown adipose tissue plays an important role in newborn thermogenesis Sweating function has been developed in newborns, in whom, however, thermal threshold is high and sweat-secretory capacity is poor. The central thermoregulatory mechanism is assumed not to be fully developed at birth, and fever is not induced by infection in neonates. Cutaneous vasomotor response is even stronger in children than adults, whereas it is not clear whether sweating activity is greater in children or not. Thus the thermoregulatory significance of dry heat loss is greater in children than in adults. Infants and children are more predisposed to heat disorders because they are more susceptible to heat congestion and to dehydration. They are acclimatized to heat more slowly and to a less degree than adults.
Key words: body temperature, thermoregulation, neonates, infants, children

 老・若・男・女の体温調節機能と温度適応能について最新知識を概説する。第1部では、出生から思春前期までのこどもについて述べる。新生児は体重の割に体表面積が広く、皮下脂肪層が薄く、体温調節反応が不十分で、中性温度域が高く狭い。一方、褐色脂肪組織が発達し、新生児の熱産生に重要な役割を演じる。出生時発汗機能はあるが、体温閾値が高く、汗分泌能が低い。体温調節中枢機能は発達が不十分らしく、感染しても発熱しない。小児では成人と比べ、発汗反応の過不足は明らかでないが、皮膚血管反応が成人よりむしろ強く、乾性熱発散の体温調節における役割が大きい。幼少児は暑さによるうつ熱や脱水を来しやすいので高温障害に罹りやすい。また暑熱順化は遅く、その程度も低い。
キーワード 体温、体温調節、新生児、乳幼児、小児
(J.Human and Living Environment), 3(1), 9/14, 1996
back

住宅建築物被害と被害防止対策

小林 康彦
大和ハウス工業株式会社 総合技術研究所

Great Hanshin Earthquake Damage Sustained by Residential Buildings and Damage Prevention Measures

Yasuhiko KOBAYASHI
aiwa House Industry Co., Ltd. Central Research Laboratory

The Great Hanshin Earthquake occurred at dawn on Jan. 17, 1995. Of the great damage brought about by the earthquake, we reviewed that sustained by residential buildings and studied the causes of damage to old wood-frame housings which suffered particularly severe damage. Based on these studies and discussions, we proposed general measures for earthquake damage prevention while focusing on the process of construction of residential buildings.
(Received: April 1, 1996 Accepted: April 16, 1996)
Key words: Great Hanshin Earthquake, earthquake damage, damage prevention measures, Building Standards Act, earthquake resistant design

 1995年1月17日未明に阪神淡路大震災は起きた。その地震によってもたらされた未曾有の被害のうち、住宅建築物に関する被害状況について概観し、特に被害の大きかった古い木造住宅についてその原因等に関し二、三の考察を行った。その上で、住宅を建てるというハード面から震災被害に対する一般的な防止対策について概説した。
キーワード 阪神大震災、地震被害、被害防止対策、建築基準法、耐震設計
(J.Human and Living Environment), 3(1), 15/19, 1996
back

都市空間における人体への日射熱負荷に緑陰による緩和効果

鄭 椙元、堀越 哲美、福岡 真由美、水谷 章夫
名古屋工業大学社会開発工学科

Relief of Human Solar Heat load by Tree Shades in an Urban Area

JEONG Chang Won, Tetsumi HORIKOSHI, Mayumi FUKUOKA and Akio MIZUTANI
Departrment of Architrcture, Nagoya Institute of Technology

The purpose of this paper is to find out the amount of relief frorn human solar heat load and thermal cormfort afforded by tree shade in an urban garden in summer. A pre-observation was carried out to measure air temperature distributlon as characteristlcs of the urban climate in Nagoya. The lower temperature zone was found around TSURUMAI garden and HIGASHIYAMA park. Six different types of sites, TSURUMAI garden and its neighboring area, were selected as the experiment sites. The experi-ments were conducted from 22 to 29 August, 1994 to find the relationship between climatic conditions and human responses. Climatic conditions, and subjects' thermal sensation were measured. Thermal comfort is affected by solar radiation in an outdoor environment. Radiant heat exchange on the human body was estimated on the basls of the measured air and surface temperature, and solar radiation. The operative temperature was modified with the effect of the radiant heat exchange. New effective temperature was calculated with the modified operative temperature. There were significant differences between sunny places and shady places in the park, and the urban canyon in the thermal sensation under equivalent new effective temperature ET* conditions. The effect of tree shade on thermal comfort was verified in this study.
(Received: Jart. 9, 1996 Accepted: Mar. 19, 1996)
Key words: urban garden, urban climate, human solar radiation load, human heat balance, new effective temperature

 本研究は、都市の暑熱時における緑がもたらす人体の熱的快適性への暑熱緩和効果を知ろうとするものである。予備調査として名古屋市の都市気温の水平分布の実測調査を行った結果、緑が多く見られる鶴舞公園と東山公園で周囲より低温域が観測された。周囲より低い気温が観測された都心部にある鶴舞公園と、周囲の市街地の樹木の繁茂状況や都市空間の性質が違う6ヵ所を選び、1994年8月22日から29日の間、温熱環境要素測定とともに、被験者を用いた心理反応を測定した。熱的快適性は屋外での日射の影響を受ける。人体の放射熱授受は気温・表面温・日射に基づいて算出された。作用温度は日射熱授受量で修正された。この修正した作用温度で新有効温度を計算した。緑陰・市街地日向の間に、等しい新有効温度でも温冷感に有意差があった。本研究によって、暑熱時における都市緑地空間の有効性が検証された。
キーワード 都市公園、都市気候、人体日射熱負荷、人体熱収支、新有功温度
(J.Human and Living Environment), 3(1), 20/28, 1996
back

熱放射源の位置が人体皮膚温・温冷感に及ぼす影響

野原 宗道、志村 欣一、宮本 征一、堀越 哲美
名古屋工業大学社会開発工学科

Influence of Geometry Thermal Radiation on Human Skin Temperature and Thermal Sensation

Munemichi NOHARA, Kinichi SHIMURA, Seiichi MIYAMOTO and Tetsumi HORIKOSHI
Department of Architecture, Nagoya Institute of Technology

The purpose of this paper is to evaluate the influence of non-uniform thermal radiation environments on the human body under equal operative temperatures. Experiments were conducted to find the effects of geometries between the human body and a radiant heating panel on the human skin tempera ture and thermal sensation. The operative temperature was set at 28℃. Six kinds of the panel position in relation to the human body were used for keeping an equal configuration factor between the panel and the body as an experimental condition: combinations of front-side-rear positions and upper-lower posi-tions. At the lower-front condition the mean skin temperature rose to 0.8℃ during expose time. In th per condition, the mean skin temperature was most apparently influenced by radiation from the fron~ ulp-in emperature begun to rise after 20 minutes from the beginning of exposu : the slde condrtron, instep skin t . r . In the upper condition, the thermal sensatron of the whole body did not depend on the panel direction but in the side condition, the thermal sensation vote fiuctuated from a hotter vote to a colder vote during the exposure time. In the lower-rear condition, the thermal sensation represented a colder vote than at the other positions. The partial operative temperature correlated to the thermal sensation of a part of the body.
(Received:Jan.22,1996 Accepted: Mar.19,1996)
Key words: thermal radiation geometry, operative temperature, mean skin temperature, thermal sensation

 不均一な熱放射環境が人体にどのような影響を与えるかを明らかにすることを目的として熱授受が一定となるような熱放射条件で実験を行った。実験は、等しい作用温度28℃を与えた。面放射熱源の位置を人体と放射源との間の形態係数が等しくなるように決めた。人体の上方・下方と前・側・背面の組合せを設定した。平均皮膚温は、前面下からの放射条件の場合に最も大きく上昇した。平均皮膚温は上方の放射源位置の場合、前面方向からの放射が最も顕著に影響した。側面からの放射条件の場合、抹消部における皮膚温上昇の時間遅れが認められた。全身温冷感は上方からの放射の場合、放射の方向にあまり左右されない。全身温冷感は、側面からの放射条件の場合、申告に上下の変動が現れた。全身温冷感は、背面下の放射条件の場合、他の条件よりもより寒い側に申告する傾向があった。部分作用温度はその方向の部分温冷感とよく対応した。
キーワード 放射源位置、作用温度、平均皮膚温、温冷感
(J.Human and Living Environment), 3(1), 29/37, 1996
back

暑熱環境における少年の体温調節反応に関する研究

都築 和代、河崎 剛、多屋 秀人、植木 章三
生命工学工業技術研究所

Thermal Responses of Prepubertal Boys at Rest during
Exposure to Heat and Wind

Kazuyo TSUZUKI-HAYAKAWA, Tsuyoshi KAWASAKI, Hideto TAYA and Shozo UEKI
National Institute of Bioscience and Human-Technology

As compared with adults, children have been reported to have a less effective thermoregulatory capability during exercise in a hot climate. This study was undertaken to investigate the thermal re-sponses and heat balance of children at rest during exposure to heat and wind. Ten prepubertal boys and 8 male graduate students served as the subjects during the summer. Each subject first rested in a thermoneutral room [air temperature (Ta) 28℃, relative humidity (Rh) 50%, air velocity (V) 0.2 m/s] and then moved to a hot room (Ta 35℃, Rh 70%, V 0.2 m/s) and stayed for I hour. They were then exposed to wind (V 1.0 m/s) from a fan placed in front of them for an additional 30 minutes under the same temperature and humidity conditions. Total sweat rate (Msw, t), Iocal sweat rate (Msw, l) and the numbers of heat activated sweat glands on the back and the upper arm, rectal temperature (Tre), skin temperatures at nine sites and metabolic rate were measured. The numbers of heat activated sweat glands on both the back and upper arms of the boys were significantly greater than that of the men, although both the Msw, l and Msw, t were similar. The mean skin temperature (Ts) of the boys was significantly higher than that of the men during the heat exposure, although the change in Tre among both groups was similar. The metabolic rate, radiative and convective heat losses and heat balance for both groups were also similar except for dry heat loss during exposure to the wlnd. The dry heat losses of the boys were significantly greater than those of the men. These results suggest that the thermoregulatory ability of prepubertal boys during heat exposure is similar to that of the men.
(Received: Feb. 29, 1996 Accepted: April 16, 1996)
Key words: prepubertal boys, thermoregulation, heat, wind, heat balance

 子供の体温調節は、成人に比べて、暑熱環境における運動中の体温調節能力が劣ると報告されてきた。この研究は、安静時の子供を暑熱と風に暴露した時の温熱反応と熱バランスを検討した。10人の思春期前期少年と8人の男子大学院生を夏期において被験者として採用した。各被験者は、最初に温熱的中性室(気温28℃、相対湿度50%、気流0.2m/s)で安静状態を計測した後に、暑熱室(気温35℃、相対湿度70%、気流0.2m/s)に移動し1時間滞在した。さらにその環境下で被験者の全面に置いた送風装置より期流速1m/sの風を30分間被験者に暴露した。全身発汗量(Msw, t)、局所発汗量(Msw, l)、背部と上腕における能動汗腺数、直腸温、9ヵ所の皮膚温、代謝量が測定された。両群のMsw, tとMsw, lは同様であったにも関わらず、少年の背部と上腕における能動汗腺数は男性よりも有意に多かった。両群のTreの変化は同様であったが、少年の平均皮膚温(Ts)は暑熱暴露中、男性よりも有意に高くなった。風に暴露中の乾性放熱量を除くと、両群の代謝量、放射と対流による放熱量および熱バランスもまた同様であった。少年の乾性放熱量は男性よりも有意に大きくなった。これらの結果は、暑熱暴露中の思春期前期少年の体温調節能力は男性とほぼ同様であることを示唆している。
キーワード 少年、体温調節、暑熱、風、熱バランス
(J.Human and Living Environment), 3(1), 38/44, 1996
back

温暖環境下での人体の局所加温刺激が
温熱生理・感覚反応に及ぼす影響

申 正和、田村 照子
文化女子大学家政学部

Physiological and Psychological Thermal Responses to Local Heating of Human Body in Warm Environments

Jeoung-hwa SHIN and Teruko TAMURA
Faculty of Home Econouac, Bunka Womenis University

The effects of local heating on physiological and psychological thermal responses were examined. Four healthy female students were used as subjects in a climatic chamber controlled at 31℃ and 50% r.h. The skin temperature beneath the heating pad increased significantly. The increase in temperature of other regions varied significantly, with the largest increases being found during abdomen and loin heating. The tympanic temperature (Tty) rose or remained unchanged during local heating. Relatively greater increases in Tty Were recorded during forearm, foot and upper arm heating. No transient falls in Tty Were noted. The sweating rates of the dorsum of the hand and the thigh increased during local heat-ing of any body region, particularly upper arms, abdomen and forearm. The effects of peripheral heating extended to the central and peripheral parts of the body surface, but the heating of the central parts affected the skin temperature of those parts only. The physiological and psychological thermal responses were different depending on the body region heated. The influence of heating of the upper extremities was greater than that of the central part of the body.
(Received: Feb.15, 1995 Accepted: April 27, 1996)
Key words: Iocal heating, thermoregulation, sweating rate, mean skin temperature

 本研究の目的は、人体に均一な局所加温を負荷した時の温熱生理的、心理的反応に及ぼす影響を検討することである。実験は、健康な成人女子4名を対象に、気温31±0.5℃、湿度50±10%の人工気候室内にて行った。その結果、加温部位皮膚温は有意に上昇し、加温部位によって上昇度に有意な差、特に、下腹、腰では高い上昇がみられた。鼓膜温はほとんどの部位の局所加温により上昇または不変であった。前腕、足、上腕の加温で皮膚温の高い上昇がみられたが一過性の下降はみられなかった。手背、大腿の局所蒸散量は大腿より手背で著しく、いずれの部位の加温でも増加し、上腕、下腹、前腕で高い上昇がみられた。各皮膚温への影響としては四肢部の加温により発汗による体幹部皮膚温の著しい低下がみられるが体幹部の加温の場合はこのような傾向を認めなかった。人体の温熱生理的、心理的反応は部位によって異なり、体幹部より上肢部加温の影響が大であるといえる。
キーワード 局所加温、体温調節、蒸発量、平均皮膚温
(J.Human and Living Environment), 3(1), 45/55, 1996
back

Back | Next