• Title/Summary/Keyword: Static charge

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Surface Modification of PET Irradiated by Ultra-Violet (Part II) - Transformation of moisture properties and physical Properties - (UV조사를 통한 PET의 표면개질(제2보) -수분특성 및 물리적 특성 변화-)

  • Choi Hae Young;Lee Jung Soon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.29 no.5 s.142
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    • pp.617-625
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    • 2005
  • The purpose of this study was to develop functional and environment-friendly polyester fabric by irradiating Ultra-Violet, which was produced by the low-pressure mercury lamp. UV irradiation was conducted with various treatment times and distances. Also, pretreatments of solvents and photoinitiator were used to improve the surface modification effects. The effects of UV irradiation on the moisture regain were found to increase gradually with increase of UV treatment time and decrease of treatment distance. Compared the effects of UVC and UVA, UVC was more effective than UVA. Moisture regain and wicking of PET was increased after UV treatment in our experimental condition. And owing to increasing of moisture regain, static charge was decreased. Pretreatment of solvents such as methanol, ethyl ether and addition of photoinitiator such as Benzophenone accelerated surface modification. The moisture regain was increased but wicking was decreased with pretreatment and addition of photoinitiatior. Therefore it is considered as inappropriate f3r clothing because of wicking effects. Yellowness, tensile strength and elasticity slightly decreased after UV irradiation.

Molecular Orbital Analyses on Hammett Substituent Constant (I) (Hammett 치환기 상수에 대한 분자궤도론적 해석 (I))

  • Byung-Kak Park;Gab-Yong Lee
    • Journal of the Korean Chemical Society
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    • v.30 no.2
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    • pp.172-180
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    • 1986
  • The Hammett's substituent constants were analyzed for the substituted-benzoic acid, -benzene and -naphthalene by LCAO MO method. Hammett's ${\sigma}$-values have been theoretically proved to treat as the sum of independent contribution of inductive effect and resonance effect. That is, Is (static inductive effect) and Id (dynamic inductive effect) corresponding to inductive effect are chosen as net charge and approximate self atom polarizability indices respectively, and ${\Delta}E^{HOMO}$ which is the difference in HOMO energy level between substituted molecule and unsubstituted molecule as resonance effect. In conclusion, it has been found that the observed ${\sigma}$-values depend on the sum of Id, Is and ${\Delta}E^{HOMO}$.

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A Study on the Chitosan Treatment of Polyester Fabrics by Low Temperature Plasma Method (저온 플라즈마법에 의한 폴리에스테르 직물의 키토산 처리가공에 관한 연구)

  • Park, Seong-Woo;Lee, Suk young;Cho, In-Sul;Cho, Hwan
    • Textile Coloration and Finishing
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    • v.9 no.5
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    • pp.42-51
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    • 1997
  • The purpose of this article is to investigate the effect of $O_{2}$ low temperature plasma treatment oft chitosan treatment of polyester fabrics. Moisture regain, static charge, crease resistance and reduction ratio of the treated fabric were measured. The results of this study were as follows: The add-on ratio and. the moisture regain of polyester fabrics treated with chitosan after treated by plasma(CP PET) were higher than those of polyester fabrics treated with only chitosan(C PET). The static charge of polyester fabrics decreased greatly with increasing the concentration of chitosan. A durability for laundering of CP PET was higher than those of C PET. The crease resistance of polyester fabrics decreased with ihcreasing the concentration of chitosan continuously. CP PET had higher decreasing rate and better durability than C PET. It showed that chitosan-treated polyester fabrics had over 90% reduction ratio after 10 times of laundering, and CP PET had better reduction ratio than C PET.

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The Ion Generation Characteristics of Charge Neutralizer Applied a Pulse Voltage (펄스전압을 적용한 전하중화장치의 이온발생 특성)

  • Moon, Jae-Duk;Chung, Suk-Hwan
    • Journal of Sensor Science and Technology
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    • v.7 no.2
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    • pp.140-146
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    • 1998
  • Methods and systems to remove static electricity are requested necessarily because the static electricity causes a flammable gas explosion, a fire, reduction of production rate in manufacturing VLSI semiconductor device and so on. In this paper, abrasion and dust contaminant of needle electrode are studied experimentally. And, frequencies and pulse durations of a high frequency pulse source were controlled effectively to minimize the abrasion of needle electrode and control generated numbers of ions. As a result, it is verified experimentally that the ion generation of charge neutralizer increases by using a high frequency pulse source.

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A Study on the Antistatic characteristics of Antistatic Garments for the Prevention of Static Electricity Hazards (정전기 재해예방을 위한 제전복의 제전특성에 관한 연구)

  • 정재희
    • Journal of the Korean Society of Safety
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    • v.5 no.1
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    • pp.57-66
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    • 1990
  • The purpose of this study is to investigate electrostatic charge condition and possibility of electrostatic hazards in case of putting on synthetic smocks and antistatic garments for the purpose of prevention of electrostatic hazards due to a human body electrical charge. It is shown in case of a synthetic smocks, electrostatic voltage by friction is about 2,900 (V), half life period is 12 second, and electrostatic charge is 1.4―1.8 ($\mu$ C). When putting on a synthetic smocks, electrostatic voltage is 2,500―2,800(V). When putting on a jumper of chemical fiber, electrostatic voltage is 8,000(V) . It is, therfore, possible to cause a electrostatic hazards. It is also shown in case of a antistatic garments, electrostatic voltage by friction is 87(V) ―280(V) (washing 90 times), half life period is 3―5 second, and electrostatic charge is 0.24―0.28($\mu$ C) which is much lower than 0.6($\mu$ C) limitation of fire and explosion occurance. When putting on a antistatic garments, electrostatic voltage is 10(V) ―125(V). In conclusion, it is shown when putting on a antistatic garments it is possible to prevent a electrostatic hazards such as fire or explosion due to human body, to prevent a destruction of semiconductor elements and capacity decline, and to prevent a misoperation of automation facilities and semiconductor electric and electronic products.

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Development of Functional Pulp Tray for Prevention of Static Electricity (정전기 방지를 위한 기능성 펄프 트레이 개발)

  • Lee, Ji-Young;Kim, Chul-Hwan;Nam, Hye-Gyeong;Park, Hyeong-Hun;Kwon, Sol;Lee, Young-Min
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.47 no.5
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    • pp.52-60
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    • 2015
  • Static electricity is an imbalance of electric charges within or on the surface of a material. All packed items that are particularly sensitive to static discharge must be protected by antistatic treatment. Otherwise, static electricity generated by an electrical insulator may cause serious damages to some sensitive electronics. In order to remove or prevent a buildup of static electricity, packed items must be treated with the application of an antistatic agent, which helps any excess charge to be evenly distributed. Functional pulp tray used for packing of electronic goods was developed with application of an antistatic agent. As the concentration of the antistatic agent increased, charging voltage and surface resistance of molded pulps decreased. The increase of humidity in surrounding atmosphere around molded pulps led to the decrease of accumulation of static charges. In conclusion, the surface treatment of the antistatic agent not only reduced or eliminated buildup of static electricity in the surface, but also prevented generation of tiny dirts from molded tray.

Design of MYNAMIC CMOS ARRAY LOGIC (DYNAMIC CMOS ARRAY LOGIC의 설계)

  • 한석붕;임인칠
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.26 no.10
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    • pp.1606-1616
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    • 1989
  • In this paper, the design of DYNAMIC CMOS ARRAY LOGIC which has both advantages of dynamic CMOS and array logic circuits is proposed. The major components of DYNAMIC CMOS ARRAY LOGIC are two-stage dunamic CMOS circuits and an internal clock generator. The function block of dynamic CMOS circuits is realized as a parallel interconnection of NMOS transistors. Therefore the operating speed of DYNAMIC CMOS ARRAY LOGIC is much faster than the one of the conventional dynamic CMOS PLAs and static CMOS PLA. Also, the charge redistribution problem by internl delay is solved. The internal clock generator generates four internal clocks that drive all the dynamic CMOS circuits. During evaluation, two clocks of them are delayed as compared with others. Therefore the race problem is completoly eliminated. The internal clock generator also prevents the reduction of circuit output voltage and noise margin due to leakage current and charge coupling without any penalty in circuit operating speed or chip area utilization.

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Variation of some Properties on Contton Knitted Under Wears by Laundering (세탁에 의한 면내의의 실용특성 변화)

  • 정운자
    • Journal of the Korean Home Economics Association
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    • v.17 no.4
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    • pp.23-28
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    • 1979
  • In order to measure the change of constructional and some properties of knitted under wears by laundry, constructional properties, such as fabric count , yarn count, loop length and cover, factor, and some properties , such as shrinkage, tearing, strength, air permeability, electrostatic charge of under wears sold in the market were tested. The results of the experiment can be summarized as follows.1. Interlock and rib were increased in wale direction after laundry and decreased in course direction , plain was decreased, in both direction after laundry. 2. Loop form of plain was changed more than those interlock and rib after laundry. 3. Tearing strength was decreased 51% in wale direction, and 70% in course direction after 20 times laundry. Air permeability was generally increased. 4. Electro static charge was increased 9 times after laundry.

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A study of static characteristics of New gas mixture in AC-PDP

  • Kwon, Shi-Ok;Kim, Ji-Sun;Joung, Bong-Kyu;Hwang, Ho-Jung
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1191-1194
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    • 2005
  • The effects of addition of $D_2$ to conventional gases on the discharge characteristics were investigated in this work with the aim of improving the voltage margin, the wall charge and the jitter. The addition of an extremely small gas-inlet amounts of $D_2$ increased the number of electrons which improves the $Xe^{\ast}$ density and $Xe_2^{\ast}$ density. As a result, the voltage margin, the jitter and the wall charge increased.

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Photoreactivity and Thermogravimetry of Copper(II) Complexes of N-Salicylideneaniline and Its Derivatives

  • Osman, Ahmed H.;Aly, Aref A.M.;El-Mottaleb, Mohamed Abd;Gouda, Gamal A.H.
    • Bulletin of the Korean Chemical Society
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    • v.25 no.1
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    • pp.45-50
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    • 2004
  • $Cu^{II}$-complexes of N-salicylideneaniline and its derivatives were not light sensitive in most solvents such as acetonitrile. A photo-decomposition occurred upon irradiation in halocarbon solvents such as $CHCl_3$. It has been suggested that such photoreactivity is attributed to the reactivity of charge-transfer to solvent (CTTS) excited state attained upon irradiation. A mechanism has been proposed to account for the results obtained. The complexes have been thermally analysed in nitrogen and static air using thermogravimetry (TG) and derivative thermogravimetry (DTG). The thermal degradation of the complexes proceeds in two or three stages. The kinetic parameters obtained from the Coats-Redfern and Horowitz-Metzger equations show the kinetic compensation effect.