• 제목/요약/키워드: $SO_2$ Removal

검색결과 1,086건 처리시간 0.037초

High Resolution HC$_3$N Observations toward the Central Region of Sagittarius B2

  • H.S-Ching;Oh, M.ishi;M.Morimoto
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
    • /
    • 한국우주과학회 1993년도 한국우주과학회보 제2권2호
    • /
    • pp.17-17
    • /
    • 1993
  • The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70${\pm}$1.32mmHg/min)compared to CF dialyzers(4.32${\pm}$0.55mmHg/min)(p<0.05). However, there was no observable difference in the UFR between the two dialyzers. Neither APD nor UFR showed any significant increase with an increasing number of reuses for up to more than 20reuses. A substantial number of failures observed in APD(larger than 20mmHe/min)on the reused dialyzers(2 out of 40 CP and S out 26 C-DAK) were attributed to the Possible damage on the fibers. The CF 15-11 HFDs which failed APD test did not show changes in the UFR compared to normal dialyzers indicating that APD is a more sensitive test than UFR test to evaluate the integrity of the fibers. 30527 T00401030527 ^x For quantitative measurement of reflected light from a clinical diagnostic strip, a prototype old reflectance photometer was designed. The strip loader and cassette were made to obtain more accurate reflectance parameters. The strip was illuminated at 45˚c through optical fiber and the intensity of reflected light was determined at rectanguLat angle using a photodiode. The kubelka-munk coefficient and reflection optical density were determined ar four different wavelengths(500,550,570 and 610nm) for blood glucose strip. For higher concentration than 300mg/41 about glucose, a saturation state of abforbance was observed at 500,550 and 570nm. The correlation between glucose concentration and parameters was the best at 610nm. 30535 T00401030535 ^x Radiation-induced fibrosarcoma tumors were grown on the flanks of C3H mice. The mice were divided into two groups. One group was injected with Photofrin II, intravenously (2.5mg/kg body weight). The other group received no Photofrin II. Mice from both groups were irradialed for approximately 15 minutes at 100,300, or 500 mW/cm2 with the argon (488nm/514.5 nm), dye(628nm) and gold vapor (pulsed 628 nm) laser light. A photosensitizer behaved as an added absorber. Under our experimental conditions, the presence of Photolfrin II increased surface temperature by at least 40% and the temperature rise due to 300 mW/cm2 irradiation exceeded values for hyperthermia. Light and temperature distributions with depth were estimated by a computer model. The model demonstrated the influence of wavelength on the thermal process and proved to be a valuable tool to investigate internal temperature rise. 30536 T00401030536 ^x We investigated the structural geometry of thirty-eight Korean femurs. The purpose of this study is to identify major geometrical differences between Korean femurs 3nd others that we believe belong to Caucasians so that we would be able to get insights into the femoral component design that fits Asians including Koreans. We utilized computerized tomography (CT) images of femurs extracted from cadavers. The CT images were transformed into bitmap data by using a film scanner, and then analyzed by using a commercially available software called Image v.1.0 and a Macintosh IIci computer.The resulting data were compared with already published data. The major results show that the geometry of the Korean femurs is significantly different from that of Caucasians: (1) the anteversion angle and the canal flare index are greater by the amount of approximately 8˚ and 0.5, respectively, (2) the shape of the isthmus cross section is more round, and (3) the distance between the teaser trochanter and the proximal border of the isthmus is shelter by about 15 mm. The results suggested that the femoral component suitable for Asians should be different from the currently-used components designed and manufactured mostly by European or American companies. 30537 T00401030537 ^x It is well known that nonlinear propagation characteristics of the wave in the tissue may give very useful information for the medical diagnoisis. In this paper, a new method to detect nonlinear propagation characteristics of the internal vibration in the tissue for the low frequency mechanical vibration by using bispectral analysis is proposed. In the method, low frequency vibration of f0( = 100Hz) is applied on the surface of the object, and the waveform of the internal vibration x (t) is measured from Doppler frequency modulation of silmultaneously transmitted probing ultrasonic waves. Then, the bispectra of the signal x (t) at the frequencies (f0, f0) and (f0, 2f0) are calculated to estimate the nonlinear propagation characteristics as their magnitude ratio, w here since bispectrum is free from the gaussian additive noise we can get the value with high S/N. Basic experimental system is constructed by using 3.0 MHz probing ultrasonic waves and the several experiments are carried out for some phantoms. Results show the superiority of the proposed method to the conventional method using power spectrum and also its usefulness for the tissue characterization. 30541 T00401030541 ^x This paper describes the implementation of a computerized radial pulse diagnosis by aids of a clinical expert. On this base, we composed of the radial pulse diagnosis system in korean traditional medicine. The system composed of a radial pulse wave detection system and a radial pulse diagnosis system. With a detection system, we detected Inyoung and Cheongu radial pulse wave and processed it. Then, we have got the characteristic parameters of radial pulse wave and also quantified that according to the method of Inyoung-Cheongu Comparison Radial Pulse Diagnosis. We defined the jugement standard of radial pulse diagnosis system and then we confirmed the possibility for realization of automatic radial pulse diagnosis in korean traditional medicine. 30545 T00401030545 ^x Microspheres are expected to be applied to biomedical areas such as solid-phase immunoassays, drug delivery systems, immunomagnetic cell separation. To synthesize microspheres for biomedical application, "two stage shot growth method" was developed. The uniformity ratio of synthesized microspheres was always smaller than 1.05. And the surface charge density (or the number of ionizable functional groups) of the microspheres synthesized by "two stage shot growth method" was 6~13 times higher than that of the microspheres synthesized by conventional seeded batch copolymerization. As a previous step for biomedical application, adsorption experiments of bovine albumin on microspheres were carried out under various conditions. The maximum adsorbed amount was obtained in the neighborhood of pH 4.5. Isoelectric point of bovine albumin is pH 5.0, so experimental result shows that it shifted to acid area. The adsorption isotherm was obtained, the plateau region was always reached at 2.Og/L (bulk concentration of bovine albumin).The effect of the kind and the amount of surface functional group was also examined. 30575 T00401030575 ^x A medical image workstation was developed using multimedia technique. The system based on PC-486DX was designed to acquire medical images produced by medical imaging instruments and related audio information, that is, doctors' reporting results. Input information was processed and analyzed, then the results were presented in the form of graph and animation. All the informations of the system were hierarchically related with the image as the apex. Processing and analysis algorithms were implemented so that the diagnostic accuracy could be improved. The diagnosed information can be transferred for patient diagnosis through LAN(local area network). 30592 T00401030592 ^x In the conventional infrared imaging system, complex infrared lens systems are usually used for directing collimated narrow infrared beams into the high speed 2-dimensional optic scanner. In this paper, a simple reflective infrared optic system with a 2-dimensional optic scanner is proposed for the realization of medical infrared thermography system. It has been experimentally proven that the intfrared thermography system composed of the proposed optic system has the temperature resolution of 0.1˚c under the spatial resolution of lmrad, the image matrix size of 256 X 240, and tile imaging time of 4 seconds. 30593 T00401030593 ^x In this paper, MIIS (Medical Image Information System) has been designed and implemented using INGRES RDBMS, which is based on a client/server architecture. The implemented system allows users to register and retrieve patient information, medical images and diagnostic reports. It also provides the function to display these information on workstation windows simultaneously by using the designed menu-driven graphic user interface. The medical image compression/decompression techniques are implemented and integrated into the medical image database system for the efficient data storage and the fast access through the network. 30594 T00401030594 ^x In this paper, computerized BEAM was implemented for the space domain analysis of EEG. Trans-formation from temporal summation to two-dimensional mappings is formed by 4 nearest point inter-polaton method. Methods of representation of BEAM are two. One is dot density method which classify brain electrical potential 9 levels by dot density of gray levels and the other is colour method which classify brain electrical 12 levels by red-green colours. In this BEAM, instantaneous change and average energy distribution over any arbitrary time interval of brain electrical activity could be observed and analyzed easily. In the frequency domain, the distribution of energy spectrum of a special band can easily be distinguished normality and abnormality. 30608 T00401030608 ^x Laboratory information system (LIS) is a key tool to manage laboratory data in clinical pathology. Our department has developed an information system for routine hematology using down-sized computer system. We have used an IBM 486 compatible PC with 16MB main memory, 210 MB hard disk drive, 9 RS-232C port and 24 pin dot printer. The operating system and database management system were SCO UNIX and SCO foxbase, respectively. For program development, we used Xbase language provided by SCO foxbase. The C language was used for interface purpose. To make the system use friendly, pull-down menu was used. The system connected to our hospital information system via application program interface (API), so the information related to patient and request details is automatically transmitted to our computer. Our system interfaced with fwd complete blood count analyzers(Sysmex NE-8000 and Coulter STKS) for unidirectional data tansmission from analyzer to computer. The authors suggests that this system based on down-sized computer could provide a progressive approach to total LIS based on local area network, and the implemented system could serve as a model for other hospital's LIS for routine hematology. 30609 T00401030609 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed a composite that is consisted of calcium phosphate and collagen. To use as the structural matrix of the composite, collagen was purified from human umbilical cord. The obtained collagen was treated by pepsin to remove telopeptides, and finally, the immune-free atelocollagen was produced: The cross linked atelocollagen was highly resistant to the collagenase induced collagenolysis. The cross linked collagen demonstrated an improved tensile strength. 30618 T00401030618 ^x This paper is a study on the design of adptive filter for QRS complex detection. We propose a simple adaptive algorithm to increase capability of noise cancelation in QRS complex detection with two stage adaptive filter. At the first stage, background noise is removed and at the next stage, only spectrum of QRS complex components is passed. Two adaptive filters can afford to keep track of the changes of both noise and QRS complex. Each adaptive filter consists of prediction error filter and FIR filter The impulse response of FIR filter uses coefficients of prediction error filter. The detection rates for 105 and 108 of MIT/BIH data base were 99.3% and 97.4% respectively. 30619 T00401030619 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed and produced a composite that is consisted of calcium phosphate and collagen. Human umbilical cord origin pepsin treated type I atelocollagen was used as the structural matrix, by which sintered or non-sintered carbonate apatite was encapsulated to form an inorganic-organic composite. With cross linking atelocollagen by UV ray irradiation, the resistance to both compressive and tensile strength was increased. Collagen degradation by the collagenase induced collagenolysis was also decreased. 30620 T00401030620 ^x We have developed a monoleaflet polymer valve as an inexpensive and viable alternative, especially for short-term use in the ventricular assist device or total artificial heart. The frame and leaflet of the polymer valve were made from polyurethane, To evaluate the hemodynamic performance of the polymer valve a comparative study of flow dynamics past a polymer valve and a St. Jude Medical prosthetic valve under physiological pulsatile flow conditions in vitro was made. Comparisons between the valves were made on the transvalvular pressure drop, regurgitation volume and maximum valve opening area. The polymer valve showed smaller regurgitation volume and transvalvular pressure drop compared to the mechanical valve at higher heart rate. The results showed that the functional characteristics of the polymer valve compared favorably with those of the mechanical valve at higher heart rate. 30621 T00401030621 ^x Explosive evaporative removal process of biological tissue by absorption of a CW laser has been simulated by using gelatin and a multimode Nd:YAG laser. Because the point of maximun temperature of laser-irradiated gelatin exists below the surface due to surface cooling, evaporation at the boiling temperature is made explosively from below the surface. The important parameters of this process are the conduction loss to laser power absorption (defined as the conduction-to-laser power parameter, Nk), the convection heat transfer at the surface to conduction loss (defined as Bi), dimensionless extinction coefficient (defined as Br.), and dimensionless irradiation time (defined as Fo). Dependence of Fo on Nk and Bi has been observed by experiment, and the results have been compared with the numerical results obtained by solving a 2-dimensional conduction equation. Fo and explosion depth (from the surface to the point of maximun temperature) are increased when Nk and Bi are increased.To find out the minimum laser power for explosive evaporative removal process, steady state analysis has been also made. The limit of Nk to induce evaporative removal, which is proportional to the inverse of the laser power, has been obtained. 30622 T00401030622 ^x N1 and N2 gross neural action potentials were measured from the round window of the guinea pig cochlea at the onset of the acoustic stimuli. N1-N2 audiograms were made by means of regulating stimulant intensities in order to produce constant N1-N2 potentials as criteria for different input tone pip frequencies. The lowest threshold was measured with an input tone pip I5 dB SPL in intensity and 12 KHz in frequency when the animal was in normal physiological condition. The procedure of experimental measurements is explained in detail. This experimental approach is very useful for the investigation of the Cochlear function. Both noN1inear and active functions of the Cochlea can be monitored by N1-N2 audiograms. 30623 T00401030623 ^x In electrical impedance tomography(EIT), we use boundary current and voltage measurements toprovide the information about the cross-sectional distribution of electrical impedance or resistivity. One of the major problems in EIT has been the inaccessibility of internal voltage or current data in finding the internal impedance values. We propose a new image reconstruction method using internal current density data measured by NMR. We obtained a two-dimensional current density distribution within a phantom by processing the real and imaginary MR images from a 4.77 NMR machine. We implemented a resistivity mage reconstruction algorithm using the finite element method and sensitivity matrix. We presented computer simulation results of the mage reconstruction algorithm and furture direction of the research. 30624 T00401030624 ^x A new method of digital image analysis technique for discrimination of cancer cell was presented in this paper. The object image was the Thyroid eland cells image that was diagnosed as normal and abnormal (two types of abnormal: follicular neoplastic cell, and papillary neoplastic cell), respectively. By using the proposed region segmentation algorithm, the cells were segmented into nucleus. The 16 feature parameters were used to calculate the features of each nucleus. A9 a consequence of using dominant feature parameters method proposed in this paper, discrimination rate of 91.11% was obtained for Thyroid Gland cells. 30625 T00401030625 ^x An electrical stimulator was designed to induce locomotion for paraplegic patients caused by central nervous system injury. Optimal stimulus parameters, which can minimize muscle fatigue and can achieve effective muscle contraction were determined in slow and fast muscles in Sprague-Dawley rats. Stimulus patterns of our stimulator were designed to simulate electromyographic activity monitored during locomotion of normal subjects. Muscle types of the lower extremity were classified according to their mechanical property of contraction, which are slow muscle (msoleus m.) and fast muscle (medial gastrocneminus m., rectus femoris m., vastus lateralis m.). Optimal parameters of electrical stimulation for slow muscles were 20 Hz, 0.2 ms square pulse. For fast muscle, 40 Hz, 0.3 ms square pulse was optimal to produce repeated contraction. Higher stimulus intensity was required when synergistic muscles were stimulated simultaneously than when they were stimulated individually. Electrical stimulation for each muscle was designed to generate bipedal locomotion, so that individual muscles alternate contraction and relaxation to simulate stance and swing phases. Portable electrical stimulator with 16 channels built in microprocessor was constructed and applied to paraplegic patients due to lumbar cord injury. The electrical stimulator restored partially gait function in paraplegic patients. 30626 T00401030626 ^x Two-Dimensional modelling of the Cochlear biomechanics is presented in this paper. The Laplace partial differential equation which represents the fluid mechanics of the Cochlea has been transformed into two-dimensional electrical transmission line. The procedure of this transformation is explained in detail. The comparison between one and two dimensional models is also presented. This electrical modelling of the basilar membrane (BM) is clearly useful for the next approach to the further. Development of active elements which are essential in the producing of the sharp tuning of the BM. This paper shows that two-dimension model is qualitatively better than one-dimensional model both in amplitude and phase responses of the BM displacement. The present model is only for frequency response. However because the model is electrical, the two-dimensional transmission line model can be extended to time response without any difficult. 30627 T00401030627 ^x A method has been proposed for the fully automatic detection of left ventricular endocardial boundary in 2D short axis echocardiogram using geometric model. The procedure has the following three distinct stages. First, the initial center is estimated by the initial center estimation algorithm which is applied to decimated image. Second, the center estimation algorithm is applied to original image and then best-fit elliptic model estimation is processed. Third, best-fit boundary is detected by the cost function which is based on the best-fit elliptic model. The proposed method shows effective result without manual intervention by a human operator. 30628 T00401030628 ^x The intelligent trajectory control method that controls moving direction and average velocity for a prosthetic arm is proposed by pattern recognition and force estimations using EMG signals. Also, we propose the real time trajectory planning method which generates continuous accelleration paths using 3 stage linear filters to minimize the impact to human body induced by arm motions and to reduce the muscle fatigue. We use combination of MLP and fuzzy filter for pattern recognition to estimate the direction of a muscle and Hogan's method for the force estimation. EMG signals are acquired by using a amputation simulator and 2 dimensional joystick motion. The simulation results of proposed prosthetic arm control system using the EMf signals show that the arm is effectively followed the desired trajectory depended on estimated force and direction of muscle movements. 30638 T00401030638 ^x A new neural network architecture for the recognition of patterns from images is proposed, which is partially based on the results of physiological studies. The proposed network is composed of multi-layers and the nerve cells in each layer are connected by spatial filters which approximate receptive fields in optic nerve fields. In the proposed method, patterns recognition for complicated images is carried out using global features as well as local features such as lines and end-points. A new generating method of matched filers representing global features is proposed in this network. 30659 T00401030659 ^x An implementation scheme of the magnetic nerve stimulator using a switching mode power supply is proposed. By using a switching mode power supply rather than a conventional linear power supply for charging high voltage capacitors, the weight and size of the magnetic nerve stimulator can be considerably reduced. Maximum output voltage of the developed magnetic nerve stimulator using the switching mode power supply is 3,000 volts and switching time is about 100 msec. Experimental results or human nerve stimulations using the developed stimulator are presented. 30768 T00401030768 ^x In this paper, we describe the design methodology and specifications of the developed module-based bedside monitors for patient monitoring. The bedside monitor consists of a main unit and module cases with various parameter modules. The main unit includes a 12.1" TFT color LCD, a main CPU board, and peripherals such as a module controller, Ethernet LAN card, video card, rotate/push button controller, etc. The main unit can connect at maximum three module cases each of which can accommodate up to 7 parameter modules. They include the modules for electrocardiograph, respiration, invasive blood pressure, noninvasive blood pressure, temperature, and SpO2 with Plethysmograph.

  • PDF

Fusion & Maximum Intensity Projection 3D 재구성 영상에서 Region Cut Subtraction의 유용성 (Usefulness of Region Cut Subtraction in Fusion & MIP 3D Reconstruction Image)

  • 문아름;지용기;최성욱;이혁;이규복;석재동
    • 핵의학기술
    • /
    • 제14권1호
    • /
    • pp.18-23
    • /
    • 2010
  • 최근 PET/CT영상의 발달로 종양의 진단 및 평가를 통해 임상에 많은 도움을 주고 있다. 특히 PET와 CT를 융합한 Fusion PET/CT영상이나 2차원 PET영상을 3차원 영상으로 재구성한 최대강도영상(Maximum Intensity Projection)은 전체적인 병변을 한눈에 시각화하는 데 유용하게 쓰이고 있다. 하지만 Fusion & MIP 3D 재구성 영상에서 $^{18}F$-FDG의 생리적 배출로 소변이나 요루주머니에 의한 열소가 나타나 병변이 겹쳐져 육안적으로 병변을 구별하는 데 어려움이 있다. 본 연구에서는 소변에 의해 나타나는 열소 부위를 제거하여 병변의 분별력을 향상하고자 한다. 2008년 9월부터 2009년 3월까지 내원한 환자 중 PET/CT 검사에서 자궁, 방광, 직장 부위의 질환으로 잔존하는 소변량이 많은 환자들을 대상으로 하였다. 분석장비는 GE사의 Advantage Workstation AW4.3 05 버전 Volume Viewer 프로그램을 사용하였다. 분석 방법은 2D PET axial volume 영상에서 제거하고자 하는 region에 ROI를 설정하여 Cut Outside를 선택한 후 coronal volume 영상도 동일한 방법을 적용한다. 다음으로 3D Tools의 threshold 값을 지정하고, Advanced Processing에서 Subtraction을 선택하여 차집합 방식으로 소변 영상만을 소거한다. 이렇게 Region Cut Subtraction이 된 2D PET영상과 CT영상으로 Fusion영상과 MIP영상을 만들어 Region Cut Subtraction하지 않은 영상과 비교한다. Fusion & MIP 3D 재구성 영상에서 Advantage Workstation AW4.3 05버전의 Region Cut Subtraction으로 환자의 소변이나 요루주머니에 의한 열소 부위를 제거할 수 있었다. Region Cut Definition을 사용한 영상에서 그렇지 않은 영상보다 소변 섭취 때문에 구별이 어렵던 병변과의 경계가 보다 명확하게 재구성되었다. 영상을 재구성하는 과정에서 Region Cut Subtraction을 사용하여 열소 부위를 제거한다면 기존에 사용하던 단순 역치범위 설정에 의한 영상 소거법보다 우수한 진단적 정보를 제공할 것이다. 특히 방광, 자궁, 직장 부위 질환의 경우, 판독의와 임상의에게 판독에 보다 유용한 영상 정보를 제공하고, 영상의 질적 향상에 도움이 될 것이라 판단된다.

  • PDF

두개인두종의 감마나이프 치료 후 장기 추적 결과 (Long-term Results of Gamma Knife Radiosurgery for Craniopharyngioma)

  • 김윤석;이도희;라동숙;전영일;안재성;전상룡;김정훈;노성우;나영신;김창진;권양;임승철;이정교;권병덕
    • Journal of Korean Neurosurgical Society
    • /
    • 제30권sup2호
    • /
    • pp.289-293
    • /
    • 2001
  • Objectives : The optimal treatment of craniopharyngioma is controversial. Despite recent advances in microsurgical management, complete surgical removal of craniopharyngioma remains very difficult. Radiation added to surgery is effective, but radiation therapy resulted in untoward side effect in young patient. Gamma knife radiosurgery offers the theoretical advantage of a reduced radiation dose to surrounding structures during the treatment of residual or recurrent craniopharyngioma compared with fractionated radiotheraphy. We described retrospective analysis of tumor size and clinical symptoms of patients after gamma knife radiosurgery in residual or recurrent craniopharyngioma were performed. Material and Methods : From September 1990 to January 2000, 18 patients of craniopharyngioma were treated by gamma knife radiosurgery. All patient had undergone surgery, but residual or recurrent tumor was found and all of them treated postoperative gamma knife radiosurgery. The mean age was 19(from 6 to 66) and male to female ratio was 10 to 8 and 8 patients were below 15 years old. In young age group(below age 15), the average volume of the tumor was $2904.8mm^3$ and mean maximal gamma knife dose was 34.9Gy. In old age group(older than 15), the average volume of the tumor was $2590.4mm^3$ and mean maximal gamma knife dose was 45.2Gy. The size of the tumor was average $2730.1mm^3$($88-12000mm^3$), mean average radiation dose was 40.7Gy and the mean prescription dose was 17.6 Gy(4-35Gy) delivered to a median prescription 50.7% isodose. Results : The follow up was from 1 year to 9 years(mean 59.1 months) after gamma knife radiosurgery. The tumor was controlled in 13(72.2%) patients. The tumor decreased in 9 patients and not changed in 4 patients. The tumor size increased in 4(22.2%) patients during follow up period. In two cases the tumor size increased because of its cystic portion was increased, but their solid portion of the tumor was not changed. In another two patients, the solid portion of the tumor was increased. So, one patient underwent reoperation and the other patient underwent operation and repeated gamma knife radiosurgery. The tumor recurred in one case(5.6%) that is a outside of irradiated site. The presenting symptoms were improved in 4 patients(improved visual acuity in 1, controlled increased intracranial presure sign in 3 patients). In one case, visual acuity decreased after gamma knife radiosurgery. The endocrine symptoms were not influenced by gamma knife radiosurgery. Conclusion : Craniopharyngioma can be treated successfully by gamma knife radiosurgery. Causes of the tumor regrowth are inadequate dose planning because of postoperatively poor margination of the tumor, close approximation of optic nerve and residual tumors outside the target lesion. Recurrence can develop 4 years after gamma knife radiosurgery. Volume is important, but the accurate targeting is more important to prevent tumor recurrence. If the tumor definition is not clear during planning gamma knife surgery, long-term image follow up is required.

  • PDF

합곡(合谷), 삼음교(三陰交) 자침(刺鍼)이 백서(白鼠) 자궁(子宮) 운동(運動) 및 Cyclooxygenase-2 발현(發現)에 미치는 영향(影響) (Effects of HapKok (LI-4) , SamUmGyo (SP-6) Acupuncture on Uterine Motility and Cyclooxygenase-2 Manifestation in Rats)

  • 이병철;이호섭;김경식;이건목;나창수;김정상;황우준
    • Journal of Acupuncture Research
    • /
    • 제17권2호
    • /
    • pp.187-208
    • /
    • 2000
  • By the activation of ovary hormone, many morphological changes occur in the epithelial cell lines and muscle cells in rat uterus. These two cells in uterus are important to the implantation of embryo, maintaining pregnancy and starting parturition. One important change associated with the morphological change of these two cells in uterus is the change on prostaglandin(PG) metabolism. Its presence and synthesis in endometriurn and myometrium in uterus affects estrous cycle and the start of embryo implantation in uterus. It also performs as an important modulator in parturition. So the abnormally weak expression of PG causes difficulty during labor and over-expression causes pre-term labor. PG biosynthesis starts from either free or liberated arachidonic acids from membrane phospholipid by phospholipase. Such arachidonic acids are converted into PG catalyzed by Cyclooxygenase. Under normal physiological condition, Cyclooxygenase-1(COX-1) having 602 units of amino acids controls the synthesis of PG. It acts as a local hormone regulating vasomodulation of blood flow, flexible muscle movement, increasing the blood permeability and contributing the protective role in preserving integrity of the stomach lining and Cyclooxygenase-2 (COX-2) is induced by the inflammation, pregnancy and increased its expression until parturition. Lipid metabolite like PG is located in uterine and expression of COX-2 increased with pregnancy. Increased expression of COX proteins in epithelial cells and myometrial cells are told to increase the muscle contractility in uterus but decreased right after the labor in rat. It is a good sign indicating that COX proteins are deeply related to the start of labor. Currently, Several studies report the use of PG and COX-2 inhibitor as medication for controlled abortion or to prevent pre-term labor but they entail various side-effects. Our study proposed to suggest use of acupuncture as an another mediator to control abortion or pre-term labor without causing unnecessary side-effects by those medicines. Two acupuncture sites, LI-4 & SP-6 were selected due to their known efficacy. From the immunohistochemical staining of COX-2, normal expression of COX-2 protein in nonpregnant SD rat's uterus revealed that COX-2 protein was primarily detected in the lumina epithelial lining and in the epithelial cell lining contacting the stromal cells. High resolution optical microscopic scanning revealed distinguishable staining in the myometrial mucosa. LI-4 acupuncture administered nonpregnant rat's uterus showed strong expression for COX-2 in endometrium contacted with lumina epithelial lining of rat uterus and in myometrial mucosa. Stromal cells showed more staining than untreated nonpregnant rat's uterus and stronger staining in stromal cells contacting myometrial layer compared to untreated nonpregnant rat's uterus. SP-6 acupuncture administered nonpregnant rat's uterus showed weak expression for COX-2 in myometrial layers and stromal cells but no staining was visible in lumina epitheliai and glandular epithelial cells. Few stromal cells and myometrial mucosa were positively stained for COX-2. Pregnant SD rat's uterus was also immunostained for COX-2 expression after 18 days of pregnancy. Unlike to untreated nonpregnant rat's uterus, luminal epithelial cells were not positively stained for COX-2 but stronger staining for COX-2 was revealed in stromal cells. LI-4 acupunctured SD rat's uterus had very strong expression of COX-2 in luminal epithelial lining. Few stromal cells showed stronger positive COX-2 staining and myometrial layers also showed more expression than untreated pregnant rat. SP-6 acupuncture administered pregnant SD rat's uterus showed positive expression of COX-2 in epithelial cells of luminal mucosa layer but weaker than that of LI-4 acupuncture treatment's case. However, strong positive staining was revealed in stromal mucosa and myometrial layers. Virgin SD rat's uterus motility index during LI-4 acupuncture was 66.52 % (Prob〉T = 0.0197) compared to its motility before the acupuncture treatment but the motility index was slighdy elevated up to 79.58 % (Prob〉T = 0.1175) after the acupuncture. During the SP-6 acupuncture treatment for 30 minutes, uterus motility index was 90.52 % (Prob〉T = 0.1832) showing lesser decrement but consequently reached similar motility index decreasal to 79.95 % (Prob〉T = 0.0215) after the acupuncture treatment as LI-4 showed. LI-4 acupuncture tend to be a quick treatment to reducing the uterus motility in a virgin rat but eventually both two acupuncture administration created very similar reduction of uterus motility seeing the index after the both acupunctures. The uterus movement monitored during the LI-4 acupuncture administered for 30 minutes, Pregnant SD rat showed decreased motility down to 77.90 % (Prob〉 T = 0.0076) compared to uterus motility before the acupuncture and it continuously decreased down to 71.81 %(Prob〉T = 0.0214) after the removal of needle. The statistical analysis using paired t-test showed significance difference for both two motility indexs at =0.05. SP-6 acupuncture administered to pregnant SD rat also had similar pattern of decreasing uterus motility index down to 74.70 % (Prob〉T = 0.1730) during the initial 30 minutes acupuncture administration and it was continuously lowered to 71.52 % (Prob〉T = 0.0155) after the acupuncture. The paired t-test resuit for SP-6 suggest prompt response of uterus motility index to the SP-6 acupuncture treatment but consequently reached same level of inducing the motility reduction as LI-4 at =0.05 level.

  • PDF

제품 디자인의 파급효과와 품질경쟁력의 결정요인에 관한 연구 (A Study on a Effect of Product Design and a Primary factor of Qualify Competitiveness)

  • 임채숙;윤종영
    • 디자인학연구
    • /
    • 제18권4호
    • /
    • pp.95-104
    • /
    • 2005
  • 본 연구의 분석목표는 제품 디자인의 결정요인을 추정하고 품질경쟁력, 제품 신뢰성, 고객충성에 대한 제품 디자인의 파급효과를 실증적으로 분석함으로써 디자인 경영이론에 유용한 시사점을 도출하는 것이다. 상기한 실증적 분석을 위하여, 한국 제조업 부문의 400개 표본기업에 대한 설문조사(2003년 8월${\sim}$10월)를 통하여 관련 측정변수들을 추출하였다. 본 연구의 분석결과는 다음과 같다. 첫째, 제품 디자인의 유의적 결정요인은 연구개발력 수준, 연구개발투자 수준, 혁신활동 수준(5S, TQM, 6Sigma 운동, QC 등)으로 추정되었다. 이 분석결과는 제품 디자인과 제품 개발을 동시적 엔지니어링(CE: concurrent engineering) 개념으로 파악하고 이들의 성과를 평가하기 위한 시스템관련 원리(system-related principle)와 행렬관련 원리(matrix-related principle)로써 서술한 Pawar and Driva(1999)를 실증적으로 뒷받침한다. 둘째, 제품 디자인의 파급효과는 제품 디자인${\rightarrow}$품질경쟁력${\rightarrow}$고객만족${\rightarrow}$고객충성의 인과관계로 나타나는 것으로 추정되었다. 즉, 제품 디자인은 고객만족을 직접적으로 유발하는 것이 아니라 품질경쟁력을 경유하여 간접적으로 고객만족을 유도한다는 것이다. 이 분석결과는 디자인 경영이 통합된 제품 품질의 중요한 결정인자라고 분석한 Flynn et al(1994), Ahire et al.(1996), Ahire and Dreyfus(2000) 등을 실증적으로 뒷받침한다. 일반적으로 제품 디자인의 접근방법으로써 3가지 즉 (1) 제품 개발자(엔지니어, 기술개발담당자, 품질관리팀)를 중심으로 하는 QFD(quality function development)의 접근방법, (2) 마케팅 담당자를 중심으로 하는 컨조인트 분석(conjoint analysis), (3) 상기의 2가지 접근방법의 상호보완적 및 동시적 결합 및 피드백의 주장(Pullman, Moore and Wardell, 2002)을 들 수 있다. 그러나 본 연구의 실증적 분석결과에는 품질경쟁력이 제품 디자인과 고객만족사이에 교량적 역할을 담당한다. 이 분석결과는 제품 디자인에 대한 품질경쟁력의 2가지 접근방법(QFD의 접근방법과 컨조인트 분석)의 조화를 이룰 수 있는 이론적 기초가 될 수 있다. 즉, 제품디자인의 결정요인 분석결과는 QFD의 접근방법에, 제품 디자인 파급효과 분석결과는 컨조인트 분석에 각각 보완적 기여를 할 수 있다. 이와 동시에, 실증적 분석결과는 Ettlie(1997)의 디자인 통합(DI) 이론에 대한 실증적 기반을 제공할 수 있다. 마지막으로, 성공적인 디자인 경영(DM)을 위해서는 최고 경영자의 지원뿐만 아니라 부처 간 의사소통의 장애요인을 제거하고 CFT(cross-functional team)를 운영함으로써 동시적 엔지니어링(CE) 및 제품 및 공정 디자인의 개발이 제품 개발의 속도를 가속화하고 디자인 품질을 높이며 시장 성공을 보증할 수 있도록 해야 한다.

  • PDF

만성 골수성 백혈병 K562세포의 분화 내성 분획에서 백혈병 유지 세포의 동정 (Presence of Leukemia-maintaining Cells in Differentiation-resistant Fraction of K562 Chronic Myelogenous Leukemia)

  • 이홍래;김미주;하가희;김소중;김선희;강치덕
    • 생명과학회지
    • /
    • 제23권2호
    • /
    • pp.197-206
    • /
    • 2013
  • 본 연구에서는 K562 만성 골수성 백혈병 세포를 이용하여, 분화 유도에 의해 암 유지/개시 세포의 자기 재생능력이 소실되는 지를 조사하였다. K562 세포의 집락(colony) 형성 능력은 PMA 처리에 의하여 현저히 억제되었고, 1 nM 이상의 PMA 처리시에는 집락이 형성되지 않았으나, 약 40%의 세포는 여전히 연한천(soft agar)에서 살아 있었다. PMA 4 nM을 3일간 처리하고 제거한 후 분리한 집락 형성 세포에 다시 10 nM PMA를 3일간 처리하였을 때, 약 70% 정도의 세포가 분화되었고, 6주 후에 PMA를 처리하였을 때는 분화율이 약 90%로 K562 모세포에 PMA를 처리한 수준에 도달하였다. 한편, imatinib-내성 K562 변종 세포들은 연한천에서 집락을 형성하지 않았으며, 대부분의 세포가 CD44 양성이었다. Imatinib 무첨가 배지에서 4개월 배양 후, 이 세포들의 표면 CD44발현량은 감소하였고, K562/R3 imatinib-내성 변종 세포에서는 연한천에서 작은 집락이 형성되었다. 이 세포에서는 imatinib-내성 변종 세포에서 소실되었던 Bcr-Abl이 다시 발현되기 시작하였고, 다른 표현형들도 부분적으로 회복되었다. 이러한 결과는 백혈병 유지 세포가 분화에 내성을 나타내는 세포이며, 분화 유도제를 오랜 기간 동안 고농도로 처리할 수 있다면 백혈병 줄기 세포를 제거하기 위한 분화 요법이 백혈병 치료에 적용될 수 있음을 시사하였다.

ICT기술을 활용한 곤충스마트팩토리팜의 현황과 미래 (Current status and future of insect smart factory farm using ICT technology)

  • 석영식
    • 식품과학과 산업
    • /
    • 제55권2호
    • /
    • pp.188-202
    • /
    • 2022
  • 최근 곤충산업은 애완곤충, 천적 등 산업에서 사료, 식용, 약용곤충으로 그 활용범위가 확대되면서 곤충 원료의 품질관리에 대한 요구가 커지고 곤충 제품의 안전성 확보에 관심이 높아지고 있다. 전세계 곤충산업 시장은 많은 소규모 농가형 기업과 소수의 대기업으로 구성되어 있으며 전통적인 수작업 사육에서 고도로 자동화되고 기술적으로 진보된 플랜트형 사육 등 다양한 기술 수준의 사육형태가 존재한다. 산업규모가 확대되는 과정에서 사육환경의 설계는 온습도, 공기질 조절과 병원체 및 기타 오염 물질의 전파를 방지하는 것은 중요한 성공 요인이 되며 사육에서 부화, 사육, 가공에 이르기까지 생산의 안전성을 유지하기 위해서 통일된 운영시스템 아래 통제된 환경이 필요하다. 따라서 곤충의 생육과 사육환경의 빅데이터화 된 데이터베이스를 기반으로 외부 환경 변화에도 안정적인 사육환경 유지가 가능하고 곤충성장에 맞추어 사육환경을 제어하며 노동력 감소와 생산성 향상을 이루기 위한 ICT 기반 곤충 스마트팩토리팜의 설계 및 운용알고리즘을 개발하는 것은 곤충산업 발전의 필수 선결조건이 되고 있다. 특히 유럽 상업용 곤충사육시설은 상당한 투자자의 관심을 받아 곤충 회사가 대규모 생산시설로 건설하고 있는데 이는 EU가 2017년 7월 물고기양식 사료원료로 곤충 단백질의 사용을 승인한 후 가능해졌으며 이를 기반으로 곤충산업의 식용, 의료 등 다른 분야도 첨단기술을 접목하는 현상이 가속화되었다. 외국 곤충산업은 주로 전세계 식품 생산량의 30%에 이르는 소비 전 폐기물이라고 불리는 식품회사의 생산과잉 원료 등을 업사이클링을 통해 재활용생태계를 형성하는데 반해 우리나라는 가정 및 가게에서 발생하는 음식물폐기물 또는 농산물 가공부산물을 주로 이용한다는 점에서 사료 수집과 영양성분 유지, 위생 등 지속가능한 산업생태계를 이루는 데 어려움을 겪고 있다. 또한, 각 곤충 종은 고유하고 특정 사육기술을 요구하고 있다는 점을 감안할 때 곤충사육자는 각기 다른 종별 접근 방식을 채택해야 하는데 대부분의 곤충기업은 여전히 소규모로 운영되며 특히 농가형 기업의 경우 지식과 경험이 도제식으로 전승되는 경우가 많아 표준화되고 규격화된 사육기술이 유지되기 어려운 반면, 일부 곤충 기업은 대규모 사육시설에 스마트 통합 제어시스템을 도입하여 먹이주기, 물주기, 취급, 수확, 청소 시스템, 가공, 품질관리, 포장 및 보관과 같은 곤충 생산과 관련된 요소가 최적화된 사육 환경과 사육프로세스로 표준화되어가는 모습을 보이고 있으며 심지어 일부 유럽기업은 AI기술로 구동되는 완전 자율 모듈식 곤충시스템으로 사육 유지관리를 하고 있는 사례도 등장하기 시작하였다. 향후 전세계 곤충산업은 공급업체로부터 알이나 작은 유충을 구입하고 곤충을 성숙시키기까지 애벌레의 비육 즉 생산원료에 중점을 두는 시스템과 알을 낳고 수확하고 유충의 초기 전처리에 이르기까지 전체 생산 과정을 다루는 시스템, 곤충 유충 생산의 모든 단계와 제분, 지방 제거 및 단백질 또는 지방 분획 등 추가 가공 단계를 다루는 대규모 생산시스템 등으로 점점 세분화할 것으로 본다. 우리나라에서도 인공지능 및 ICT 첨단기술을 활용한 곤충스마트팩토리팜 연구 및 개발 등이 가속화되고 있어 곤충이 기존 사료, 식품 뿐만 아니라 천연 플라스틱 또는 천연성형소재 등 2차산업의 탄소제로 소재로 활용할 수 있도록 특정 종 육종과정 단축이나 기능성 강화를 위한 사육제어가 가능하도록 곧 곤충 스마트팩토리팜 한국형 맞춤사육시스템이 등장할 수 있을 것으로 보이며, 특히 곤충 제품의 지속 가능성을 높이기 위해 사료 및 자원 사용에 대한 통합 소프트웨어 접근 방식을 개발하는 것에 중점을 두고 진행되고 있다.

소아 청소년 골육종 재발 후 치료성적 : 한국의 단일기관 성적 (Outcome after relapse in childhood and adolescent osteosarcoma : single institution experience in Korea)

  • 이윤정;이현재;김동호;임중섭;이준아;박경덕;전대근;이수용
    • Clinical and Experimental Pediatrics
    • /
    • 제51권1호
    • /
    • pp.78-83
    • /
    • 2008
  • 목 적 : 골육종은 소아 청소년기에 뼈에 발생하는 가장 흔한 악성종양으로 종양 제거술 및 집중적 항암 화학요법을 시행한 경우에도 약 30-40%에서 재발하는 매우 침습적인 질환이다. 하지만 아직까지 재발한 골육종의 예후 및 예후인자에 대한 연구가 부족한 상태이다. 저자들은 치료 후 재발한 골육종 환아의 치료성적 및 재발 후 생존율에 영향을 주는 요인들을 분석하고자 하였다. 방 법 : 1985년 2월부터 2004년 2월까지 원자력병원에서 골육종으로 치료한 461명의 환아 중 재발한 180명의 의무기록을 후향적으로 조사하였으며 재발 후 생존율과 재발 후 예후인자로 재발병소의 위치, 재발 후 치료 방법, 원발병소의 수술전 화학요법에 대한 병리학적 반응도, 첫 진단 시 전이여부 및 재발기간을 분석하였다. 결 과 : 전체 재발율은 39%였고 재발한 골육종 환아의 5년 및 10년 재발 후 생존율은 각각 13%와 4%였다. 평균 재발기간은 15개월이었다. 재발 후 5년 생존율에 영향을 주는 인자는 재발 부위(폐, 39%; 원발병소, 0%; 폐와 뼈의 재발, 25%; 기타 부위의 재발, 12%), 병소 부위 절제 여부(절제한 경우 38%; 절제하지 않은 경우 11%), 재발기간(1년 이내에 재발한 경우 13%, 1년 이후에 재발한 경우 44%)이었다. 결 론 : 재발된 골육종 환자의 생존율은 높지 않다. 하지만 본 연구에서는 재발된 병변을 적극적으로 치료할 때 생존율이 향상됨을 보여주고 있으며 특히 재발기간이 길고 폐에 재발된 경우에는 수술 및 항암 화학요법과 그 외의 적극적인 치료가 필요하다 하겠다.

맹출 장애를 가진 상악 제1대구치의 외과적 노출을 이용한 치험례 (CASE REPORTS OF TREATMENT OF ERUPTION-DISTURBED MX. FIRST MOLAR BY SURGICAL EXPOSURE)

  • 석충기;남동우;김현정;김영진;남순현
    • 대한소아치과학회지
    • /
    • 제31권1호
    • /
    • pp.11-18
    • /
    • 2004
  • 치아의 맹출이란 구강내로 치아가 출현하기 전의 악골 내에서의 이동, 구강에 출현하여 교합면에 이르기까지의 이동, 그리고 교합면 도달이후의 추가적인 이동 등 모두를 포괄적으로 의미하는 용어이다. 맹출은 대부분 유전적으로 결정되며 치아가 성장 발육 과정에 따라 구강내로 맹출되는 과정은 preeruptive alveolar bone stage, alveolar bone stage와 mucosal stage로 구분할 수 있는데, 이들 과정의 어느 단계에서도 장애가 발생하면 치아가 맹출하지 않는다. 맹출 장애의 원인으로는 치배의 부정위, 정상 맹출로의 방해, 치낭 혹은 치주인대의 손상 등이 있다. 맹출 장애의 치료에는 유치발거 및 맹출 공간확보, 외과적 노출, 외과적 정위, 외과적 노출 후 견인이 있고, 이 중 외과적 노출이 가장 기본적인 술식이다. 외과적 노출은 영구치를 둘러싸는 점막, 골, 병소, 경우에 따라 치낭 등을 제거하여 개방된 맹출로를 확보하는 것이고, 형성된 맹출로는 레진관(celluloid crown)의 접착, 거타 퍼챠 혹은 산화 아연 유지놀 시멘트, 치주 포대 등을 노출된 부위에 충전하여 개방성을 유지하여야 한다. 외과적 노출시에는 치경부 치근의 백악질을 노출시키지 않도록 하여야 하며, 인접치아의 치주 조직이나 치근의 손상도 피해야 한다. 또한 노출 후 치아는 각화된 치은에 위치하여야 한다. 외과적 노출 중에 가해진 손상의 정도는 치아의 병리 생리학적 이상의 발현에 영향을 미치므로 주의하여야 한다. 본 증례들은 상악 제1대구치가 맹출 장애를 가진 증례들이었으며 이를 개선하기 위해 위의 사항을 고려하여 외과적 노출을 시행하였고, 맹출 장애를 효과적으로 개선할 수 있었다.이지 않았다(p>0.05). 5. DIFOTI 이미지의 광투과율과 CLMS의 병소 깊이에 대한 상관 계수는 -0.688이었으나(p<0.05), LFD의 측정값은 유의성을 보이지 않았다.ococcus mutans에 의한 인공치태 형성을 억제하였다.향을 미치는 해양환경 요인으로 나타났다. 고현항 내측수괴는 동계에 가조도와 칠천도 사이의 중앙 수역까지 확장되어 나타났다.착제의 종류는 별다른 영향을 주지 않은 것으로 분석되었다. 결합강도의 비교에서 컴포머가 글라스 아이어노머에 비해 우수한 것으로 평가되어 소아 환자의 유구치 심미 수복재료로서의 가능성이 입증되었다.후 중합한 군이 산소억제층의 두께가 평균 49%의 감소되었으며(p<0.05), 이들 산소를 차단한 군 간의 유의차는 없었다.며 CYP1A2유전자형에 따른 영향은 관찰할 수 없었다. CYP1A2유전자형에 따른 생체내 대사능을 관찰하는 실험이 향후 이루어 져야 할 것으로 사료된다.san film보다 큰 수증기 투과도를 보였다.적으로 유의한 차이를 보이지 않았다.y tissue layer thinning은 3 군모두에서 관찰되었고 항암 3 일군이 가장 심하게 나타났다. 이상의 실험결과를 보면 술전 항암제투여가 초기에 시행한 경우에는 조직의 치유에 초기 5 일정도까지는 영향을 미치나 7 일이 지나면 정상범주로 회복함을 알수 있었고 실험결과 항암제 투여후 3 일째 피판 형성한 군에서 피판치유가 늦어진 것으로 관찰되어 인체에서 항암 투여후 수술시기는 인체면역계가 회복하는 시기를 3주이상 경과후 적어도 4주째 수술시기를 정하는 것이 유리하리라 생각되었다.한 복합레진은 개발의 초기단계이며, 물성의 증가를 위한 연구가 필요할 것으로 사료된다.또 다른 약물인

  • PDF

스퍼터링 증확 CdTe 박막의 두께 불균일 현상 개선을 위한 화학적기계적연마 공정 적용 및 광특성 향상 (Application of CMP Process to Improving Thickness-Uniformity of Sputtering-deposited CdTe Thin Film for Improvement of Optical Properties)

  • 박주선;임채현;류승한;명국도;김남훈;이우선
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
    • /
    • pp.375-375
    • /
    • 2010
  • CdTe as an absorber material is widely used in thin film solar cells with the heterostructure due to its almost ideal band gap energy of 1.45 eV, high photovoltaic conversion efficiency, low cost and stable performance. The deposition methods and preparation conditions for the fabrication of CdTe are very important for the achievement of high solar cell conversion efficiency. There are some rearranged reports about the deposition methods available for the preparation of CdTe thin films such as close spaced sublimation (CSS), physical vapor deposition (PVD), vacuum evaporation, vapor transport deposition (VTD), closed space vapor transport, electrodeposition, screen printing, spray pyrolysis, metalorganic chemical vapor deposition (MOCVD), and RF sputtering. The RF sputtering method for the preparation of CdTe thin films has important advantages in that the thin films can be prepared at low growth temperatures with large-area deposition suitable for mass-production. The authors reported that the optical and electrical properties of CdTe thin film were closely connected by the thickness-uniformity of the film in the previous study [1], which means that the better optical absorbance and the higher carrier concentration could be obtained in the better condition of thickness-uniformity for CdTe thin film. The thickness-uniformity could be controlled and improved by the some process parameters such as vacuum level and RF power in the sputtering process of CdTe thin films. However, there is a limitation to improve the thickness-uniformity only in the preparation process [1]. So it is necessary to introduce the external or additional method for improving the thickness-uniformity of CdTe thin film because the cell size of thin film solar cell will be enlarged. Therefore, the authors firstly applied the chemical mechanical polishing (CMP) process to improving the thickness-uniformity of CdTe thin films with a G&P POLI-450 CMP polisher [2]. CMP process is the most important process in semiconductor manufacturing processes in order to planarize the surface of the wafer even over 300 mm and to form the copper interconnects with damascene process. Some important CMP characteristics for CdTe were obtained including removal rate (RR), WIWNU%, RMS roughness, and peak-to-valley roughness [2]. With these important results, the CMP process for CdTe thin films was performed to improve the thickness-uniformity of the sputtering-deposited CdTe thin film which had the worst two thickness-uniformities of them. Some optical properties including optical transmittance and absorbance of the CdTe thin films were measured by using a UV-Visible spectrophotometer (Varian Techtron, Cary500scan) in the range of 400 - 800 nm. After CMP process, the thickness-uniformities became better than that of the best condition in the previous sputtering process of CdTe thin films. Consequently, the optical properties were directly affected by the thickness-uniformity of CdTe thin film. The absorbance of CdTe thin films was improved although the thickness of CdTe thin film was not changed.

  • PDF