• Journal of the Microelectronics and Packaging Society
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• v.7 no.3
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• pp.45-54
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• 2000

The effect of electropolishing far stamped leadframe on the removal of the edge burr and residual stress relief was examined. The present study showed that the electropolishing could be used for enhanced surface quality of stamped leadframes. The electropolishing was performed at the condition of 60% phosphoric acid electrolyte, 5 ampere of current and 3 cm electrode gap at $70^{\circ}C$ for 2 minutes for Alloy42 type leadframe, and $50^{\circ}C$ for 1.5 minutes for C-194 type leadframe. The FWHM values from X-ray diffraction showed that residual stress of electropolished leadframe recovered to the level of as-received raw materials and surface roughness measured by using AFM tuned out to be improved by 0.079 $\mu\textrm{m}$ and 0.014 $\mu\textrm{m}$ ($R_{rms}$) far alloy 42 and C-194 type leadframes, respectively. The plated thickness using XRF showed the improved uniformity in thickness variation by 0.4~0.5 $\mu\textrm{m}$ and grain growth, which is favorable for interface adhesion, was also observed from the bake test samples. We could certify dimensional stability of leadframe with inspection by means of 3D-topography and hardness measurements.

• Journal of the Korean Ceramic Society
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• v.39 no.12
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• pp.1143-1148
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• 2002

Precipitated calcium carbonate is one of the most versatile mineral fillers and is consumed in an wide range of products including paper, paint, plastics, rubber, textiles, sealants, adhesives and printing ink and can be produced by several methods. Calcium carbonate has three isomorphism; vaterite, aragonite and calcite, with numerous variations of morphology in the natural mineral or organism. Formation process of vaterite in the reaction of system $Ca(OH)_2-CH_3OH-H_2O-CO_2$ were investigated by measuring the electrical conductivity, $Ca^{2+}$ ion concentration, pH in the slurries and by means of X-ray diffraction and electron microscopic observation. It was clearly established that the reaction temperature is important variable in the carbonation process; in general over 50${\circ}C$, the vaterite was precipitated with the calcite and aragonite. SEM and XRD observations revealed that the vaterite formation could be prepared the temperature range of 40 to 50${\circ}C$ and mean size of particles in this range is controlled from 0.5 to 0.8 ${\mu}m$.

• Journal of the Korean Magnetics Society
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• v.17 no.1
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• pp.34-37
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• 2007

The crystallographic and magnetic properties of $Fe_{0.9}Zn_{0.1}Cr_2S_4$ have been studied by X-ray diffractometer(XRD), vibrating sample magnetometer(VSM) and $M\"{o}ssbauer$ spectroscopy measurement. The crystal structure was determined by the normal cubic spinel of space group Fd3m and the lattice constant was $a_0=9.9967\;{\AA}$. The specific phenomenon which looks like cusp pattern at 77 K was observed in magnetization corves(ZFC : Zero Field Cooling) under 100 Oe applied field. $N\acute{e}el$ temperature($T_N$) was determined to be 153 K by VSM and $M\"{o}ssbauer$ spectra. The asymmetric 8-line profile has been observed at 4.2 K, which was attributed by the colossal electric quadupole interaction(${\Delta}E_Q$), ${\Delta}E_Q$ has 2.22 mm/s at 4.2 K. The ${\Delta}E_Q$ abruptly decreases around 77 K and then it disappears above 77 K with diminishing of 8-line pattern. The isomer shift $\delta$ at room temperature is 0.48 mm/s relative to Fe metal, which means that the charge state of Fe ions is ferrous in character.

• Korean Journal of Materials Research
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• v.8 no.12
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• pp.1146-1151
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• 1998

The crystallization behaviour of perovskite $PbTiO_3$ for the samples heat- treated at various temperatures for various times in the $PbO-TiO_2-A1_2O_3-SiO_2$, glass system has been investigated by the means of X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses. Higher crystallinity obtained in the sample heat-treated at higher temperature for longer time. With increasing heat-treatment time, dielectric constant of the samples heat-treated at $610^{\circ}C$ and $650^{\circ}C$ increased, but that of the sample heat- treated at $800^{\circ}C$ decreased. Loss tangent of the heat-treated samples was not much influenced by heat-treatment conditions. Piezodielectric charge constant was approximately $1.0\times10^{-12}~8.0$\times$10^{-12}C/N$ in the samples heat-treated at $800^{\circ}C$ for 1h, 2h, and 8h.

• Journal of Korean Academy of Nursing
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• v.23 no.3
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• pp.377-398
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• 1993

A survey of infant practices was conducted to provide information on which to base planned nursing interventions. The subjects were a convenience sample of 168 mothers visiting out - patients departments of five general hospitals and one public health center in Seoul for immunizations or treatment for common colds for their infants from two to 12 months of age. Data collection was carried out from July 8th to September 30th, 1991 using a questionnaire of 84 questions, 31 on the type of feeding, 22 on supplementary feeding and 21 on demographic infer mation. The results are summarized as follows : 1) The type of feeding was primarily artificial feed-ing (63.1%), followed by mixed feeding (22%) and breast feeding (14.9%) of the 59 mothers expecting during pregnancy to breast feed, 54. 2% changed artificial feeding and 30.5% went on to breast feed as they had expected. For mothers expecting to continue breast feeding over seven months. only one infant was being breast fed for over seven months. 2) For the 106 mothers using artificial feeding, 70. 8% hed attempted breast feeding, 64% of them for less than a month. Breast milk had been suppressed by for medication (38.7%) : 34.9% had used no specia] means. 3) The major reasons for replacing breast feeding with artificial feeding were the infants' demand for more milk (47.2% ) and insufficient supply of breast milk (49.3％). 4) Most mixed feeding was started at the age of one to three months (59.5%). Only 34.4% gave an artificial feeding after breast feeding : most (46%) alternated breast feeding with artificial feeding. On the whole, the motive for mixed feeding was the lack of breast milk (70.3%). 5) Many mothers (81.8%) were adding vitamin or mineral supplements to artificial milk and 51.5% were adding something to faciliate digestion. As for the method of sterilizing milk bottles and nipples, 56% had sterilized them together in boiling water from the beginning : 27% were just washing the bottles after boiling only once initially when measuring artificial milk powder, 31. 5% of the mothers over filled the measuring spoon rather than to the level. 6) The mother's occupation was related to her way of feeding. Mothers at home full time did more breast feeding than mothers employed outside the home. (x²=5.72, p=〈0.05). 7) Most mothers began supplementary food, from three to four months (48.8%) : 11.2% began later than seven months. Supplementary food was given between milk feedings by 67.2% of the mothers : 19.2% gave it before a milk feeding. Some mothers(26.4%) made their own supplementary food : 19.2% used ready - made supplementary food products for convenience. Recommendations for nursing interventions included : 1. Prenatal education about the advantages of breast feeding and breast care, and home visits after delivery for counselling related to breast feeding. Correct preparation of artificial feeding methods need to be taught in both pre & postnatal periods. In addition, specific education about supplementary feeding needed. 2. Further research is indicated about the Perceived lack of supply of breast milk and about the effectiveness of nursing interventions to Promote breast feeding.

• The Journal of Korean Academy of Prosthodontics
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• v.19 no.1
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• pp.7-16
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• 1981

The technology of precision attachments has developed at such a pace that from a very few T-shaped attachments and bar attachments from the years 1915 to 1935 since removable bridge utilizing a T-shaped intracoronal attachment was constructed by Dr. Herman E.S. Chayes in 1906. There are now more than 120 models of the most diversified designs, ready made or laboratory fashioned. In 1971, 126 attachments were listed and classified by Mensor in his E M Attachment Selector. This selector consists of five charts giving specifications as to type, vertical dimensions, application, type of resilience, size of movement, type of retention and type of material and alloy. Thus the E M Attachment Selector is a useful guide for dentists to choose the attachment for his patients. But dentists should apply the attachment in each patient's case according to an accurate diagnosis and treatment plan. This paper is a case report of removable partial dentures utilizing CSP, PD and Bar attachment on a patient who needed full mouth reconstruction. Patient has right first, second molar and left first molar on the upper arch and also left first molar, first premolar and right canine on the lower arch. (Fig. 5)All remaining teeth are relatively healthy in their supporting tissues. On upper arch, ring shape CSP attachment was designed on left first molar and modified ring shape CSP attachment was designed on right first and second molar as the direct retainer of the removable partial denture. Full palatal coverage was used as the major connector in this case. (Fig. 23) On lower arch, author first splinted with a fixed bridge between left first molar and second premolar and a splint bar between left second premolar and right canine. (Fig. 11) A lower removable partial denture in which was designed with an Aker clasp on the left first molar and a PD attachment on .the right canine was constructed. (Fig. 17) This denture could get additional support from anterior splint bar. After both removable partial dentures were delivered to the patient (Fig. 26), author evaluated function of the dentures and supporting structures of the abutment teeth by means of clinical and X-ray examinations for eighteen months. According to the examination data author came to the conclusion that the prognosis of this case was excellent.

• Korean Journal of Health Education and Promotion
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• v.19 no.1
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• pp.59-85
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• 2002

The purpose of this study was to examine the health promoting behavior of university students and its related factors. A self-administered questionnaire survey was carried out for 1,031(male, 477, female, 554) students from 7 universities in Taegu from March 10 to April 15 2000. Collected data were analyzed by the $X^2$-test, t-test, ANOV A and structural equation modeling analysis. The results of this study were as follows; Mean score of health promoting behavior of women was higher than mean score of men(p〈0.01). According to the subordinate fields, female students showed significantly higher scores in the fields of stress management, nutrition, personal relations and alcohol-cigarette(p〈0.05). And in male students, the only fields of exercise had meaningfully higher score(p〈0.01). The highest degree of performance was marked in alcohol-cigarette field in female, and interpersonal field in male. In Both male and female students, the lowest field was health responsibility. The mean score of health promoting behavior showed significant differences in intermediating factors such as age, health education and grade in male, and such as grade, pocket money for a month, taking health education, perceived body shape and gastrointestinal symptoms in female(p〈0.05). The mean score of health promoting behavior showed significant differences in cognitive-perceptual factors and cues to action such as perceived health status, perceived benefits, perceived barriers, and health concern of parents in both male and female(p〈0.05). By the results of structural equation modeling analysis in male students, the economic status, gastrointestinal symptoms and perceived body shape as lean had significant direct effects on cognitive-perceptual factors($\mid$T$\mid$〉2.0). Grade and health concern of parents had significant direct effects on health promotion behaviors($\mid$T$\mid$〉2.0). In female students, perceived body shape as lean and perceived body shape as fat had significant direct effects on cognitive-perceptual factors($\mid$T$\mid$〉2.0). Grade, pocket money and health concern of parents had significant direct effects on health promotion behaviors($\mid$T$\mid$〉2.0). On the consideration of above findings, it is recommended that perceived health status and perceived benefits should be raised and perceived barriers should be lowered to increase health promoting behaviors, by means such as institutional approach which can enhance the primary prevention for a disease. In addition, the health policy for improving parents' concern about health as well as university students, through various ways such as health education, consulting, and health program, should be employed.

• Resources Recycling
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• v.8 no.4
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• pp.45-56
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• 1999

The purpose of tlus sludy was to preparc raw material powder for Mn-Zn iclrile, h m mined mill scale and fero-Mn, usins a co-spray roasting process The mill scale and ferra-Mn uscd in this raalins process was rcf~nedb y mesn-ns of a slxc~apl rxcss ~nvolvinm~a te~ialsc ontalning imp~u-ltleso r less than 100 pprn In this study an effeclive spray roaster system. wllich produces fme complex oxide powder, collects produccd ~owder.,m d prcvel~tse ~~llssiooifi HCI gas. was also manufactured. By means of spray~ngp urifcd raw malerial solu~lionl nln a manufacued high tcmpervture rumace. &-ferrite powder and a comnpleu o ~ d e powder of Fe,O; and M,x203 were manufactured. The chmcterlstics of the composllion. surface urca, and p'miicle size dismbulion or the produced powder were exmined. ptoduced powdcr was then ~ m e dwi tli ZnO powder. aid olher addilives of defined cornposnion, and Mn-Zn femite cares werc praiuccil by meuns of Sorlning and closely controlled sintering processes. The magpelic p~oprlieso f c olo~ss, initlal permeability. mauin~u~mnn agnehc flux. coz~civcr orcc and residual magnccic flux for the above cores we,= measured, and fmm Il~ase I-csulls the eflicacy of lhe co-spray roasling pncess to pl.ellare raw material powder lor Mn-Zn ferntc was established

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.8 no.2
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• pp.21-29
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• 2013

Objectives : The purpose of this study is to investigate the relation between cervical spine lateroflexion and upper limb numbness after whiplash injury by traffic accident. Methods : Outpatients who visited Jaseng korean medicine hospital after traffic accident took cervical MRI. Patients who had Normal disc and bulging disc were reviewed to measure the cervical lateroflexion by C2-C7 Cobb's angle & scalenus muscle's length through neutrality AP X-ray views. For statistics, we used SPSS version 18.0 for windows. Results : Groups classified into difference of scalenus muscle's length were showen statistical significance than into cobb's angle. Means of numbness group's length difference are $4.18{\pm}2.26mm$ and that of non-numbness group is $1.59{\pm}1.17mm$. Unilateral numbness group had greater angle and longer of length's difference than non-numbness group. Conclusions : The more severe the lateroflexion of the upper extremity numbness occurs well. Group classifed into difference of scalenus muscle's length has more tendency of occurrence of upper limb numbness than that into cobb's angle. And upper limb numbness occurs more frequently at the same direction of lateroflexion.

• Progress in Medical Physics
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• v.13 no.1
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• pp.1-8
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• 2002

Accurate knowledge of the distribution of contamination electrons ( which comes from mainly gantry head by Compton scattering, pair production, and tray: henceforth called leptons ) at the surface and in the first centimeters of tissue is essential for the clinical practice of radiation oncology. Such lepton tends to reduce or eliminate the ‘skin-sparing’ advantage of megavoltage photon beam radiotherapy, This information is needed to prescribe a absorbed dose to a skin volume at a few millimeter depth in high energy therapeutic radiation photon beam All experiments were done with 15 MV photon beam from a dual energy linear accelerator (Clinac 1800, Varian). Field size is defined by ranged from 10.0$\times$10.0 to 30.0$\times$30.0 $\textrm{cm}^2$. The absorbed dose and distribution of leptons in therapeutic radiation beam (15 MV) are investigated by means of variable blocked beams of 30.0$\times$30.0 $\textrm{cm}^2$ and dose beam profiles partly removed leptons with a copper plate. A numerous leptons mainly are distributed as shape of broad cone in the central photon beam and leptons path length in the water are shorter than 2.5 cm because of the leptons energy having around 3.0 MeV. These results clearly appears that the subtraction of leptons from the total depth dose curve not only lower the absolute dose in the buildup region and surface dose, it also causes a shift of d$_{max}$ to a deeper depth.