열처리와 비열처리 퍼머넌트 웨이브에 의한 모발 손상 비교

김진아 ( Jin Ah Kim ),김정은 ( Jung Eun Kim ),박선우 ( Sun Woo Park ),제갈미 ( Mi Jegal ),손아름 ( Ah Reum Sohn ) 한국미용학회 2009 한국미용학회지 Vol.15 No.2

To find out the hair damage between non-heat-treated permanent wave (B hair) and heat-treated permanent (C hair), we have compared their forms of wave, physical and chemical changes with those of virgin hair. Looking through the changes of waves occurred by permanent, we were able to see silkier and smoother hair from the heat-treated permanent hair, whereas non-heat-treated permanent waved hair shows wave through out and bouncy hair. Both treated hair (D hair) was not even. Moreover, it only formed a smaller wave and resulted in fuzzy hair. Looking under the SEM, the cuticle surface of B hair showed splitting and breakage. Both C hair and D hair showed profound damage such as the detachment of cuticle. As the level of hair damage increases, the stretch intensity of hair decreases. Whereas stretch, swelling and alkaline solubility of hair increases. The morphological damage of C hair was more severe than that of B hair, but severity of physical and chemical damage is decreasing, which may be due to involvement of hair conservative agent in the process of heat-treated permanent. It is unavoidable that hair damage occurs in the process of permanent application. In addition, repeated application of heat-treated and non-heat-treated permanent wave increased the damage level drastically. These findings represent that there is much to be done to improve in order to minimize the level of hair damage in the process of permanent application.

Design and Analysis of a Permanent-Magnet-Assisted Switched Reluctance Motor

Hongsik Hwang,Jin Hur,Cheewoo Lee 대한전기학회 2014 Journal of Electrical Engineering & Technology Vol.9 No.6

A permanent-magnet-assisted switched reluctance motor (SRM) having small excitation poles, where phase coils are concentrically wound on the poles and thin permanent magnets are inserted inside the poles, is proposed in this paper. The insertion of permanent magnets into the stator excitation poles has a significant influence on positive torque improvement leading to a boost in efficiency. Three key design parameters such as the thickness of permanent magnets, space between two adjacent permanent magnets, and the width of stator excitation poles are determined during a design procedure in terms of the enhancement of positive torque. Step-by-step design modification and a comparison between the proposed permanent-magnet-assisted SRM and no-permanent-magnet SRM have been conducted by means of static torque comparison along with dynamic performance. The first prototype from steel laminations up to its physical assembly has been constructed.

스트레이트퍼머넌트 시술시 소맥분과 난백분의 두피․ 모발 손상의 비교 분석

이하나,조희숙 한국피부과학연구원 2011 대한피부미용학회지 Vol.9 No.4

In this study the effects of the wheat flour, Egg White and straight permanent cream on hair damage was comparative analyze when performed in straight permanent. In hair thickness and tensile strength were observed cuticle surface, microbial amount, red spots index and the state of the scalp dead skin cells by observing the degree damage of the scalp were analyzed. In thickness and tensile strength of hair permanent product + egg white group, permanent product+ flour group, straight permanent group was greater reduction rate in the order. After permanent hair straight application, the cuticle of hair was observed with intervals of cuticle epidermal scales was observed in state of fall off. The color of the scalp red spots and small amount of microorganisms present in the permanent product + egg white group, permanent product + flour group, straight permanent group were increased in the order. Also, after the straight permanent application of the scalp exfoliating dead skin lifting of the state observed phenomena, delamination was observed. Large and little scale was distributed irregularly.

시스테인을 주성분으로 하는 퍼머넌트 환원제의 웨이브 형성과 모발 손상도

박수경(Soo-Kyung Park),김미영(Mi-Young Kim),문덕환(Deog-Hwan Moon) 한국인체미용예술학회 2012 한국인체미용예술학회지 Vol.13 No.3

This study was conducted to prepare the fundamental data for healthy hair, to assess the level of hair damage and wave formation on permanent agents with cysteine compounds according to the frequency of permanent, price and company of production. The model was a 20 year old woman with virgin hair which had never been chemically treated, and a sample was cut by the length of 20cm at the point and 5cm away from the scalp. Each sample of pieces was 2g and was used as permanent samples. The author observed and examined the hair roughness with SEM according to frequency of permanent, price and company of production, the level or damage were classified into 5 levels, and evaluated by ten professors of hairdressing in the Department of Cosmetology. There were significant differences in hair roughness according to the frequency of permanent (P<0.05). The level of roughness was the lowest in price of 5,000 Korean won. The levels of wave formation were higher in price and the more expensive. As above results, there were significant differences in hair roughness according to the frequency of permanent. The author recommend that the hair dresser should use protective material on hair in the procedure of permanent, and the author considers that various reducing agents should be developed and that there will be further research on hair permanent reducing agents.

한국과 중국여성 모발의 원형아이론 열펌 시 시술방법에 따른 모발손상 연구

김은영 ( Eun Young Kim ),정지영 ( Jee Young Jung ),고경숙 ( Kyoung Sook Ko ) 한국미용학회 2016 한국미용학회지 Vol.22 No.3

This study has identified hair damage after applying heat permanent by using silicon circular iron on women hair from Korea and China. As a result, KJ treating with direct permanent with silicon circular iron on women hair from Korea was turned out to have the highest level of hair thickness as .0355 ± .0017 ㎜ when measuring the hair thickness. According to the result of measuring hair moisture, the content of moisture was turned out to be in a descending order of KY, KJ, CY, and CJ. According to the tensile strength, it was shown to be higher in a descending order of KJ, KY, CJ, and CY. Reduction rate of tensile strength of women hair from Korea was turned out to be lowest as 7.93% in KJ. According to the result of overall comparison from observation of hair cuticle in the experiment group based on virgin hair (K, C), KJ applied with J-permanent had relatively even scale intervals and stable hair cuticle compared to virgin hair (K). According to the result of observation of microstructure, a degree of hair floating on women hair from Korea was turned out to be 412.41 ± 6.52 nm in KY applied with softening permanent. Hence, it was reduced by 3.8% compared to the control group (K) representing the least amount of damage. According to aforementioned results, damage was reduced when treating with direct permanent without softening the hair in overall if applying iron permanent on women hair from Korea and China.

Design and Analysis of a Permanent-Magnet-Assisted Switched Reluctance Motor

황홍식,이치우,허진 대한전기학회 2014 Journal of Electrical Engineering & Technology Vol.9 No.6

A permanent-magnet-assisted switched reluctance motor (SRM) having small excitationpoles, where phase coils are concentrically wound on the poles and thin permanent magnets areinserted inside the poles, is proposed in this paper. The insertion of permanent magnets into the statorexcitation poles has a significant influence on positive torque improvement leading to a boost inefficiency. Three key design parameters such as the thickness of permanent magnets, space betweentwo adjacent permanent magnets, and the width of stator excitation poles are determined during adesign procedure in terms of the enhancement of positive torque. Step-by-step design modification anda comparison between the proposed permanent-magnet-assisted SRM and no-permanent-magnet SRMhave been conducted by means of static torque comparison along with dynamic performance. The firstprototype from steel laminations up to its physical assembly has been constructed.

Design and Analysis of a Permanent-Magnet-Assisted Switched Reluctance Motor

Hwang, Hongsik,Hur, Jin,Lee, Cheewoo The Korean Institute of Electrical Engineers 2014 Journal of Electrical Engineering & Technology Vol.9 No.6

A permanent-magnet-assisted switched reluctance motor (SRM) having small excitation poles, where phase coils are concentrically wound on the poles and thin permanent magnets are inserted inside the poles, is proposed in this paper. The insertion of permanent magnets into the stator excitation poles has a significant influence on positive torque improvement leading to a boost in efficiency. Three key design parameters such as the thickness of permanent magnets, space between two adjacent permanent magnets, and the width of stator excitation poles are determined during a design procedure in terms of the enhancement of positive torque. Step-by-step design modification and a comparison between the proposed permanent-magnet-assisted SRM and no-permanent-magnet SRM have been conducted by means of static torque comparison along with dynamic performance. The first prototype from steel laminations up to its physical assembly has been constructed.

열유동 연성해석을 통한 대용량 직접구동형 발전기 냉각시스템의 적합성 평가

박형준(Hyung Joon Park),한승호(Seung Ho Han) 대한기계학회 2021 大韓機械學會論文集B Vol.45 No.1

해상의 일정한 풍속과 우수한 풍질로 해상풍력발전기가 선호되는 추세이나, 설치비용 및 유지 · 보수 비용이 상대적으로 높아 단위 발전기당 발전용량을 올리기 위하여 터빈이 대형화되고 있다. 저자 등에 의해 제안된 대용량 6.2 MW 하이브리드 직접구동형 발전기는 2단의 AFPM(axial flux permanent magnet) 발전기와 RFPM(radial flux permanent magnet) 발전기를 조합하여, 단위 체적 및 중량 대비 발전량이 높은 출력성능을 보여주었다. 그러나 대용량 발전기에서는 전력 생산 시 구리 및 철 손실에 의한 발열이 심하여 고정자에서 절연손상 그리고 영구자석에서 불가역 감자현상이 나타날 수 있다. 대용량 발전기의 초기설계 단계부터 고정자 및 영구자석 주위의 열전달 특성을 분석하여 발열 시 이를 냉각시킬 수 있는 냉각장치의 설계가 요구된다. 본 연구에서는 6.2 MW급 하이브리드 발전기에 적합한 강제대류 및 히트 파이프를 이용한 공랭식과 수랭식 냉각장치를 대상으로 실제 작동조건을 고려한 전자기 및 열-유동 연성해석으로 발전기의 열전달 특성을 해석적으로 평가하였다. 고정자 절연손상의 한계온도를 규정한 IEC 60076-11에 의거하여 두 냉각장치 모두 B등급을 만족하였으며, 영구자석의 불가역 감자현상에 대한 한계온도인 90°C도 충족함을 확인하였다. Offshore wind speeds tend to be faster and steadier than land wind speed. Hence, the electricity generated by offshore wind power is higher per amount of capacity in installed wind turbines. Wind turbines used in offshore environments are generally larger and taller because of reduced building and maintenance costs. The authors developed a 6.2 MW class hybrid direct-drive generator, which was constructed in two stages using 2.5 MW axial-flux permanent-magnet (AFPM) and 1.2 MW radial-flux permanent-magnet (RFPM) machines. Because heat was significantly generated owing to copper and iron losses, the AFPM and RFPM machines experienced insulation failure of stators and demagnetization of permanent magnets under sever thermal conditions. In this study, the heat transfer in the 6.2 MW class hybrid direct-drive generator using the developed cooling systems, e.g., forced-air-type and liquid-cooled-type systems, was analyzed numerically, and the actual operation conditions were considered. The results for the thermal-fluid interaction analysis of the designed cooling systems showed that the temperatures of the stators and permanent magnets decreased significantly. The cooling systems satisfied the IEC 60076-11 requirements, in which the limit temperature of the stator insulation failure was specified, and the limit temperature for the irreversible demagnetization of permanent magnets was 90°C.

Permanent Mold를 이용한 저압주조공정의 스케줄링

박용국,양정민,김진곤 한국경영공학회 2009 한국경영공학회지 Vol.14 No.1

In this article, scheduling of a casting sequence is studied in a low-pressure casting foundry employing permanent molds. Since a permanent-mold casting shop usually simultaneously manufactures a range of casts with an identical alloy but different shapes and weights, it faces the task of production scheduling on a frequent and regular basis. It is critical to achieve an optimal casting schedule in order to maximize the production rate and raw material efficiency under the constraints of limited resources; melting furnaces, molds, and alloted operation time for each casting machine. To solve this practical problem - fulfilling the objectives of casting the assigned mixed orders for the highest raw material efficiency within the given time span, we implement simple integer programming. A case study reflecting a real production environment in a typical casting plant, manufacturing multiple kinds of casts simultaneously using permanent molds, proves that the proposed method can provide a feasible solution with a high accuracy for a complex, multi-variable and multi-constraint optimization problem. Employing this simple methodology, a low-pressure casting foundry is able to produce a mixed order of casts with a maximum furnace utilization within the due date.

Improved Method for Calculating Magnetic Field of Surface-Mounted Permanent Magnet Machines Accounting for Slots and Eccentric Magnet Pole

Zhou, Yu,Li, Huaishu,Wang, Wei,Cao, Qing,Zhou, Shi The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

This paper presented an improved analytical method for calculating the open-circuit magnetic field in the surface-mounted permanent magnet machines accounting for slots and eccentric magnet pole. Magnetic field produced by radial and parallel permanent magnet is equivalent to that produced by surface current according to equivalent surface-current method of permanent magnet. The model is divided into two types of subdomains. The field solution of each subdomain is obtained by applying the interface and boundary conditions. The magnet field produced by equivalent surface current is superposed according to superposition principle of vector potential. The investigation shows harmonic contents of radial flux density can be reduced a lot by changing eccentric distance of eccentric magnet poles compared with conventional surface-mounted permanent-magnet machines with concentric magnet poles. The FE(finite element) results confirm the validity of the analytical results with the proposed model.