• Title/Summary/Keyword: Heating System

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A Study of material analysis and its experimentation of metamorphosis and its utilities in Copper Alloy plates for contemporary metal craft (현대금속공예용 동합금판의 재료분석과 형질변환 실험 및 응용에 관한 연구)

  • Lim, Ock-Soo
    • Archives of design research
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    • v.17 no.4
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    • pp.241-250
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    • 2004
  • In this research, the copper alloy plates C2200, C5210, C7701, C8113 were selected to make datum and to identify further usage of metal craft experimentation. For its experimentation, the general welding and TIG welding methods were researched; for 2nd experimentation, the Reticulation and Electroforming skill's differences in color and temperature were researched. With these methods 3 different kinds of works are introduced for sample studies. For this research, Dr. Lee, Dong-Woo who works in Poongsan Metal Co, supported 4 kinds of copper alloy metals. Which are Commercial bronze (Cu-Zn), Deoxidiged Copper(Cu-Sn-P), Nickel Silver (Cu-Ni-Zn), and White Bronze (Cu-Ni); they were applied partly and wholly by the method of Laminatin, Reticulation, Fusing, and Electroforming skills. In case of C2200, the brass, the A. C. TIG welding method is better under 2mm slight plate; the D.C. TIG welding is better upper 2mm plate; and 250~300$^{\circ}C$ is recommended for remain heat treatment. In case of C5210, not having Hydrogen in high temperature return period, doesn't need Oxygen in high temperature and hardening in comparative high temperature neither, it is good for welding. It contains Sn 2-9% ad P 0.03-0.4% generally; and in accordance with the growth rate of Sn contain amount, the harden temperature boundary become broad. In case of cold moment after welding, they are recommended that higher speed TIG welding, smaller melting site and less than 200$^{\circ}C$ for pre-heating temperature. In case of C7701, the 10-20% Ni, 15-30% Zn are widely used.. If it is upper 30% Zn, it become (${\alpha}+{\beta}$) system and adhesive power rate become lower, and the productivity become lower in low temperature but the productivity become higher in high temperature. Nickel Silver's resistance of electricity is well; and the heatproof and incorrodibility is good, too. Lastly, in case of C8113, good at persistence in salty and grind; high in strength of high temperature. In case of white brass, contain 10-30% Nickel and hardened in high temperature and become single phrase. For these reason, the crystallization particles easily become large, if the resistance become higher small amount of Pb, P, S separation rate become higher.

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An Economic Factor Analysis of Air Pollutants Emission Using Index Decomposition Methods (대기오염 배출량 변화의 경제적 요인 분해)

  • Park, Dae Moon;Kim, Ki Heung
    • Environmental and Resource Economics Review
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    • v.14 no.1
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    • pp.167-199
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    • 2005
  • The following policy implications can be drawn from this study: 1) The Air Pollution Emission Amount Report published by the Ministry of Environment since 1991 classifies industries into 4 sectors, i. e., heating, manufacturing, transportation and power generation. Currently, the usability of report is very low and extra efforts should be given to refine the current statistics and to improve the industrial classification. 2) Big pollution industries are as follows - s7, s17 and s20. The current air pollution control policy for these sectors compared to other sectors are found to be inefficient. This finding should be noted in the implementation of future air pollution policy. 3) s10 and s17 are found to be a big polluting industrial sector and its pollution reduction effect is also significant. 4) The effect of emission coefficient (${\Delta}f$) has the biggest impact on the reduction of emission amount change and the effect of economic growth coefficient (${\Delta}y$) has the biggest impact on the increase of emission volume. The effect of production technology factor (${\Delta}D$) and the effect of the change of the final demand structure (${\Delta}u$) are insignificant in terms of the change of emission volume. 5) Further studies on emission estimation techniques on each industry sector and the economic analysis are required to promote effective enforcement of the total volume control system of air pollutants, the differential management of pollution causing industrial sectors and the integration of environment and economy. 6) Korea's economic growth in 1990 is not pollution-driven in terms of the Barry Commoner's hypothesis, even though the overall industrial structure and the demand structure are not environmentally friendly. It indicates that environmental policies for the improvement of air quality depend mainly on the government initiatives and systematic national level consideration of industrial structures and the development of green technologies are not fully incorporated.

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Analysis Study on the use of Frequency and the Cooking Method of Leaf and Stem Vegetables in High School Foodservice (고등학교 급식식단의 엽경채류 식재료 사용 빈도 및 조리방법 분석 연구)

  • Min, Ji-Hyeon;Lee, Jong-Kyung;Kim, Hyun-Jung;Yoon, Ki-Sun
    • Journal of Food Hygiene and Safety
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    • v.31 no.4
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    • pp.250-257
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    • 2016
  • This study was conducted to extract the factors affecting the microbial safety of leaf and stem vegetables in the high school foodservice and to provide information for supplying the safe foodservice menu. The lunch and dinner menu (1,945 data) of the total 6 high schools at the Central and the South Region in March, June, September, and December were collected. The frequency analysis and the multiple correspondence analysis (MCA) based on the 3 factors (potentially hazardous food (PHF), leafy and stem vegetables in the menu, the cooking methods) were conducted. The most frequent PHF was the menu of blanched vegetables, salads, seaweeds and fried chicken. The most frequent consumed leaf and stem vegetables were spinach, chive, lettuce, Western cabbage, perilla leaf, iceberg lettuce, chicory, leek and broccoli. MCA based on the leaf and stem vegetables, the region, and the cooking method (cooked/non-cooked) showed that garlic stem and spinach were more used in the Central Region, while water drop-wort were more used in the South Region. Iceberg lettuce, Bok choy and leek were included frequently in the PHF menu. Plant products frequently used in PHF menu requires the food safety system such as Good Agricultural Practice (GAP) to reduce the microbial risk. The menu database according to raw materials based on cooking methods (heating or mixing) as well as the development and verification of menu based on the microbial safety will be contributed to provide the safer foodservice menu.

HACCP Application of Instant Ablactation Baby Food Processing (즉석 이유식 제조시 HACCP의 적용)

  • 이정규;노완섭
    • The Korean Journal of Food And Nutrition
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    • v.14 no.5
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    • pp.457-466
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    • 2001
  • In this study. HACCP system was applied to improve the quality of instant ablactation baby food with rising sanitary problem among SunSig(powder of roasted grains and vegetables) . It took about 9min 30 second to produce and the temperature status of raw materials were 30.9∼31.8$\^{C}$. Raw material and production phase goods had average 6.2 in pH and 0.23∼0.63 in water activity. The average number of total aerobic bacteria(TAB) and coliform were 1.4$\times$10$^4$ CFU/g, 5.5$\times$10 CFU/g in raw materials. And the number became 8.7$\times$10$^2$ CFU/g, 6.9$\times$10 CFU/g after 1st grinding step. The distributions of TAB and coliform in equipments were 3.8$\times$10$^4$ CFU/㎠, 8.0$\times$10 CFU/㎠ on the average. According to storage temperature, variations of number of TAB coliform were slight at 4$\^{C}$ but increased at 20$\^{C}$ and 30$\^{C}$ . Therefore following subjects can be issued on the basis of results. Minimize the storage time and keep at cool temperature. 1st and 2nd grinders should be managed hygienically. Establish the heating step during the production of instant action baby food. Instant ablactation baby food produced should be stored at cool and freeze condition.

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Assessment of Sensory and Safety Evaluation of Cook/Chill Pajeon (Cook-chill 파전의 관능성 및 안전성 평가)

  • Lyu, Eun-Soon;Jeong, Dong-Kwan
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.5
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    • pp.674-680
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    • 2005
  • The purposes of this study were to compare the effect of several reheating treatments (heating in the frying pan, convection oven and microwave oven) on sensory characteristics and to evaluate the safety during storage period of cook/chill Pajeon. The sensory evaluations were made on 5 sensory attributes by a 9-member panel using quantitative descriptive analysis (QDA). The fresh cooked Pajeon and the Pajeon reheated in the frying pan obtained a significantly (p<0.01) higher score in taste than the ones reheated in a convection oven and microwave oven. The reheated cook/chill Pajeon had a significantly (p<0.01) lower score in flavor than the freshed cooked one. Regardless of the reheating methods, sensory scores in texture of the Pajeon reheated at $v$ for 1 day were not different from that of fresh cooked one. However, the scores of the reheated ones in a convection oven and in a microwave oven decreased with storage time up to 5 days at $3^{\circ}C$. On the other hand, the Pajeon reheated in the frying pan, even after 3 days' storage at $3^{\circ}C$, was not found to be inferior to the freshed cook one in every quality attributes except flavor. Therefore, the reheating treatment in frying pan may be superior to those in a convection oven and a microwave oven. The safety of Pajeon was also evaluated by measuring total count, coliform count, psychrotrophic count, acid value and peroxide value during 5 days of storage periods at $4^{\circ}C$. Total counts of Pajeon was ranged from not detectable to $5.2\times10^2$ CFU/g. The coliform and psychrotroph were not detected at all experiments. The acid values were ranged from 1.90 to 4.03 mg of KOH/g of fat until 5 days at $4^{\circ}C$. And the peroxide values were ranged from 3.63 to 12.50 meq of peroxide/kg of fat until 5 days of storage period. Therefore, these results demonstrated that Pajeon is microbiologically and chemically safe during 5 days of storage period at refligeration temperature.

A study on the Meaning Contact of ManChwi Pavilion's Place Transmission and Sense of Prototype Landscape (만취정(晩翠亭)의 장소 전승과 원형경관향유 양상)

  • Lee, Seung-Yeon;Shin, Sang-Sup;Kahng, Byung-Seon
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.34 no.3
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    • pp.38-49
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    • 2016
  • This study is based on the assumption that the documentations, and poetry form a basis for undertone of the location and original landscape explored by inference and enjoyment aspects; the significance has been inferred by investigating the original location, relocated location, and the original landscape of Imsil Manchwi Pavilion. The results of the attempted research for locational value, and preservation of the original landscape before and after the relocation of Imsil Manchwi Pavilion is as follows. Firstly, Manchwi, meaning evergreen, was made a pseudonym of KimWi. The name reflects an image two evergreen pine trees facing one another. The poetry form presents the eternal fidelity. In addition, considering the symbolic plant and the meaning of evergreen pine trees specified on the pavilion, the name is derived from the fidelity, longevity of the family, vitality and so on. Secondly, Manchwi Pavilion was founded in the location, known as the snakehead form, that represents the vitality. Snake faces the swallow form over the river, therefore, it connotes the wishes for fidelity and prosperity of the family. Manchwi Pavillion is prostrate pheasant form which is suitable for those who look for a hiding place or place for their study. It is noticeable that the location infers and hand down the efforts on succession for prosperity of the family and the study. Thirdly, it is estimated that Manchwi Pavilion was established between 1572 and 1582; and the relocation was conducted in the late 1880s. Fourthly, although eternal fidelity was presented in Manchwi Pavillion with locational language, the Manchwi Pavillion after its relocation next to KimWi's grave implies the tendency of the changed value: the commemoration of the ancestors, and prosperity of the family. Fifthly, after the relocation of the pavilion, the proportion of the rooms with Korean heating system, so-called'Ondol'has been increased for its best use in all seasons. And its veranda for extension and its verse couplet implies that this connote the original meaning and pursuit of the study. Sixthly, the way that the poetry portrays pine trees, pond, plants, valleys, and streams shows the aspect of enjoyment of the landscapes and the meaning of fidelity, pure mind, free and easy life, self-examination, the frailty of human life. Lastly, despite the difference between tenth poetic language of three Sipyoung and Wonwoon Sipyeong, exploring the landscape based on the analysis on the poetry can be a basis on the maintenance and restoration of the original landscape as the inspiration and the meaning show that Wonwoon Sipyeong maintains the aspect of the author enjoying original landscape.

Optimal Operation of Gas Engine for Biogas Plant in Sewage Treatment Plant (하수처리장 바이오가스 플랜트의 가스엔진 최적 운영 방안)

  • Kim, Gill Jung;Kim, Lae Hyun
    • Journal of Energy Engineering
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    • v.28 no.2
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    • pp.18-35
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    • 2019
  • The Korea District Heating Corporation operates a gas engine generator with a capacity of $4500m^3 /day$ of biogas generated from the sewage treatment plant of the Nanji Water Recycling Center and 1,500 kW. However, the actual operation experience of the biogas power plant is insufficient, and due to lack of accumulated technology and know-how, frequent breakdown and stoppage of the gas engine causes a lot of economic loss. Therefore, it is necessary to prepare technical fundamental measures for stable operation of the power plant In this study, a series of process problems of the gas engine plant using the biogas generated in the sewage treatment plant of the Nanji Water Recovery Center were identified and the optimization of the actual operation was made by minimizing the problems in each step. In order to purify the gas, which is the main cause of the failure stop, the conditions for establishing the quality standard of the adsorption capacity of the activated carbon were established through the analysis of the components and the adsorption test for the active carbon being used at present. In addition, the system was applied to actual operation by applying standards for replacement cycle of activated carbon to minimize impurities, strengthening measurement period of hydrogen sulfide, localization of activated carbon, and strengthening and improving the operation standards of the plant. As a result, the operating performance of gas engine # 1 was increased by 530% and the operation of the second engine was increased by 250%. In addition, improvement of vent line equipment has reduced work process and increased normal operation time and operation rate. In terms of economic efficiency, it also showed a sales increase of KRW 77,000 / year. By applying the strengthening and improvement measures of operating standards, it is possible to reduce the stoppage of the biogas plant, increase the utilization rate, It is judged to be an operational plan.

A Study on the Sanctuary of the Residence in East China Sea Skirts Area (동중국해권 민가의 성역(聖域)에 관한 연구)

  • Youn, Lily;Onomichi, Kenji
    • Korean Journal of Heritage: History & Science
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    • v.43 no.2
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    • pp.60-81
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    • 2010
  • Jeju Island, in Korea, shows many characteristics that are differentiated from the rest of Korea. Its culture is rooted in mythology which advocates a egalitarian, rather than hierarchical, social structure, the place of women in the home is relatively high, and the formation of buildings, the separation of cooking and heating facilities, and the living format of residential homes is dissimilar. These disparities in culture indicate that Jeju Island's heritage was not formed only from influences from the North, but also from other places as well. To fill in the blanks, residential homes in Jeju Island were compared with those scattered throughout the East China Sea, which connect the southern coastline of the Korean peninsula and Jeju Island. The regions encompassed by the East China Sea, sharing the Kuroshio current and a seasonal wind, can be considered as one cultural region integrating cultural aspects from the continental North and the oceanbound South. The unique characteristics of southern culture as seen in southern residences was examined through an investigation of the sacred places in which gods were considered to dwell. First, the myths of these areas usually concerned with the ocean, and a sterile environment made sustenance impossible without a dual livelihood, usually taking on the forms of half-farming and half-fishing, or half-farming, half-gardening. Although family compositions were strongly matricentric or collateral thanks to southern influence, a patriarchical system like those found in the North were present in the upper classes and in the cities. Therefore, residential spaces were not divided based on age or gender, as in hierarchical societies, but according to family and function. Second, these areas had local belief systems based on animism and ancestor worship, and household deities were closely related to women, agriculture and fire. The deities of the kitchen, the granary and the toilet were mostly female, and the role of priest was often filled by a woman. After Buddhism and Confucianism were introduced from mainland Korea, China and Japan, the sacred areas of the household took on a dual form, integrating the female-focused local rites with male-centered Buddhist and Confucian rites. Third, in accordance with worship of a kitchen deity, a granary deity, and a toilet deity led to these areas of the home being separated into disparate buildings. Eventually, these areas became absorbed into the home as architectural technology was further developed and lifestyles were changed. There was also integration of northern and southern cultures, with rites concerning granary and toilet deities coming from China, and the personality of the kitchen deity being related to the southern sea. In addition, the use of stone in separate kitchens, granaries, and toilets is a distinguishing characteristic of the East China Sea. This research is a part of the results gained from a project funded by the Korea Research Foundation in 2006.

A Study on Exchange and Cooperation between South and North Korea through UNESCO Intangible Cultural Heritage of Humanity : Focusing on joint nomination to the Representative List (인류무형문화유산 남북 공동등재를 위한 교류협력방안 연구)

  • Song, Min-Sun
    • Korean Journal of Heritage: History & Science
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    • v.50 no.2
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    • pp.94-115
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    • 2017
  • 'Arirang folk song in the Democratic People's Republic of Korea' was inscribed to the Representative List of the Intangible Cultural Heritage of Humanity in 2014 and 'Tradition of kimchi-making in the Democratic People's Republic of Korea' followed in 2015. It is presumed that North Korea was influenced by the Republic of Korea inscribing 'Arirang, lyrical folk song in the Republic of Korea' to the list in 2012 as well as 'Kimjang, making and sharing kimchi in the Republic of Korea' in 2013. These cases show the necessity (or possibility) of cultural exchanges between the two Koreas through UNESCO ICH lists. The purpose of this article is to explore the possibility of inter-Korean cultural integration. Therefore, I would like to review UNESCO's ICH policy and examine the ways of cooperation and joint nominations to the Representative List of Intangible Cultural Heritage of Humanity between the two Koreas. First, I reviewed the amendments to the laws and regulations of the two Koreas and how the two countries applied the UNESCO Convention for the Safeguarding of the Intangible Cultural Heritage. Although the cultural exchange is a non-political field, given the situation between South and North Korea, it is influenced by politics. Therefore, we devised a stepwise development plan, divided into four phases: infrastructure development, cooperation and promotion, diversification, and policymaking and alternative development. First a target group will be needed. In this regard, joint nominations to the Representative List of the UNESCO Intangible Cultural Heritage of Humanity will be suitable for cooperation. Both countries have already started separate nominations on shared ICH elements to the UNESCO lists. Therefore, I have selected a few elements as examples that can be considered for joint nominations. The selected items are makgeolli (traditional liquor), jang (traditional soybean sauce), gayangju (homebrewed liquor), gudeul (Korean floor heating system), and jasu (traditional embroidery). Cooperation should start with sharing information on ICH elements. A pilot project for joint nomination can be implemented and then a mid-term plan can be established for future implementation. When shared ICH elements are inscribed on UNESCO ICH lists, various activities can be considered as follow-ups, such as institution visits, performances, exhibitions, and joint monitoring of the intangible cultural heritage. Mutual cooperation of the two Koreas' intangible cultural heritage will be a unique example between the divided countries, so its value will be recognized as a symbol of cultural cooperation. In addition, it will be a foundation for cultural integration of the two Koreas, and it will show the value of their unique ICH to the world. At the same time, it will become a good example for joint nominations to the Representative List recommended by UNESCO.

A STUDY ON THE IONOSPHERE AND THERMOSPHERE INTERACTION BASED ON NCAR-TIEGCM: DEPENDENCE OF THE INTERPLANETARY MAGNETIC FIELD (IMF) ON THE MOMENTUM FORCING IN THE HIGH-LATITUDE LOWER THERMOSPHERE (NCAR-TIEGCM을 이용한 이온권과 열권의 상호작용 연구: 행성간 자기장(IMF)에 따른 고위도 하부 열권의 운동량 강제에 대한 연구)

  • Kwak, Young-Sil;Richmond, Arthur D.;Ahn, Byung-Ho;Won, Young-In
    • Journal of Astronomy and Space Sciences
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    • v.22 no.2
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    • pp.147-174
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    • 2005
  • To understand the physical processes that control the high-latitude lower thermospheric dynamics, we quantify the forces that are mainly responsible for maintaining the high-latitude lower thermospheric wind system with the aid of the National Center for Atmospheric Research Thermosphere-Ionosphere Electrodynamics General Circulation Model (NCAR-TIEGCM). Momentum forcing is statistically analyzed in magnetic coordinates, and its behavior with respect to the magnitude and orientation of the interplanetary magnetic field (IMF) is further examined. By subtracting the values with zero IMF from those with non-zero IMF, we obtained the difference winds and forces in the high-latitude 1ower thermosphere(<180 km). They show a simple structure over the polar cap and auroral regions for positive($B_y$ > 0.8|$\overline{B}_z$ |) or negative($B_y$ < -0.8|$\overline{B}_z$|) IMF-$\overline{B}_y$ conditions, with maximum values appearing around -80$^{\circ}$ magnetic latitude. Difference winds and difference forces for negative and positive $\overline{B}_y$ have an opposite sign and similar strength each other. For positive($B_z$ > 0.3125|$\overline{B}_y$|) or negative($B_z$ < -0.3125|$\overline{B}_y$|) IMF-$\overline{B}_z$ conditions the difference winds and difference forces are noted to subauroral latitudes. Difference winds and difference forces for negative $\overline{B}_z$ have an opposite sign to positive $\overline{B}_z$ condition. Those for negative $\overline{B}_z$ are stronger than those for positive indicating that negative $\overline{B}_z$ has a stronger effect on the winds and momentum forces than does positive $\overline{B}_z$ At higher altitudes(>125 km) the primary forces that determine the variations of tile neutral winds are the pressure gradient, Coriolis and rotational Pedersen ion drag forces; however, at various locations and times significant contributions can be made by the horizontal advection force. On the other hand, at lower altitudes(108-125 km) the pressure gradient, Coriolis and non-rotational Hall ion drag forces determine the variations of the neutral winds. At lower altitudes(<108 km) it tends to generate a geostrophic motion with the balance between the pressure gradient and Coriolis forces. The northward component of IMF By-dependent average momentum forces act more significantly on the neutral motion except for the ion drag. At lower altitudes(108-425 km) for negative IMF-$\overline{B}_y$ condition the ion drag force tends to generate a warm clockwise circulation with downward vertical motion associated with the adiabatic compress heating in the polar cap region. For positive IMF-$\overline{B}_y$ condition it tends to generate a cold anticlockwise circulation with upward vertical motion associated with the adiabatic expansion cooling in the polar cap region. For negative IMF-$\overline{B}_z$ the ion drag force tends to generate a cold anticlockwise circulation with upward vertical motion in the dawn sector. For positive IMF-$\overline{B}_z$ it tends to generate a warm clockwise circulation with downward vertical motion in the dawn sector.