• 제목/요약/키워드: Q4A

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Why A Multimedia Approach to English Education\ulcorner

  • Keem, Sung-uk
    • Proceedings of the KSPS conference
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    • 대한음성학회 1997년도 7월 학술대회지
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    • pp.176-178
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    • 1997
  • To make a long story short I made up my mind to experiment with a multimedia approach to my classroom presentations two years ago because my ways of giving instructions bored the pants off me as well as my students. My favorite ways used to be sometimes referred to as classical or traditional ones, heavily dependent on the three elements: teacher's mouth, books, and chalk. Some call it the 'MBC method'. To top it off, I tried audio-visuals such as tape recorders, cassette players, VTR, pictures, and you name it, that could help improve my teaching method. And yet I have been unhappy about the results by a trial and error approach. I was determined to look for a better way that would ensure my satisfaction in the first place. What really turned me on was a multimedia CD ROM title, ELLIS (English Language Learning Instructional Systems) developed by Dr. Frank Otto. This is an integrated system of learning English based on advanced computer technology. Inspired by the utility and potential of such a multimedia system for regular classroom or lab instructions, I designed a simple but practical multimedia language learning laboratory in 1994 for the first time in Korea(perhaps for the first time in the world). It was high time that the conventional type of language laboratory(audio-passive) at Hahnnam be replaced because of wear and tear. Prior to this development, in 1991, I put a first CALL(Computer Assisted Language Learning) laboratory equipped with 35 personal computers(286), where students were encouraged to practise English typing, word processing and study English grammar, English vocabulary, and English composition. The first multimedia language learning laboratory was composed of 1) a multimedia personal computer(486DX2 then, now 586), 2) VGA multipliers that enable simultaneous viewing of the screen at control of the instructor, 3) an amplifIer, 4) loud speakers, 5)student monitors, 6) student tables to seat three students(a monitor for two students is more realistic, though), 7) student chairs, 8) an instructor table, and 9) cables. It was augmented later with an Internet hookup. The beauty of this type of multimedia language learning laboratory is the economy of furnishing and maintaining it. There is no need of darkening the facilities, which is a must when an LCD/beam projector is preferred in the laboratory. It is headset free, which proved to make students exasperated when worn more than- twenty minutes. In the previous semester I taught three different subjects: Freshman English Lab, English Phonetics, and Listening Comprehension Intermediate. I used CD ROM titles like ELLIS, Master Pronunciation, English Tripple Play Plus, English Arcade, Living Books, Q-Steps, English Discoveries, Compton's Encyclopedia. On the other hand, I managed to put all teaching materials into PowerPoint, where letters, photo, graphic, animation, audio, and video files are orderly stored in terms of slides. It takes time for me to prepare my teaching materials via PowerPoint, but it is a wonderful tool for the sake of presentations. And it is worth trying as long as I can entertain my students in such a way. Once everything is put into the computer, I feel relaxed and a bit excited watching my students enjoy my presentations. It appears to be great fun for students because they have never experienced this type of instruction. This is how I freed myself from having to manipulate a cassette tape player, VTR, and write on the board. The student monitors in front of them seem to help them concentrate on what they see, combined with what they hear. All I have to do is to simply click a mouse to give presentations and explanations, when necessary. I use a remote mouse, which prevents me from sitting at the instructor table. Instead, I can walk around in the room and enjoy freer interactions with students. Using this instrument, I can also have my students participate in the presentation. In particular, I invite my students to manipulate the computer using the remote mouse from the student's seat not from the instructor's seat. Every student appears to be fascinated with my multimedia approach to English teaching because of its unique nature as a new teaching tool as we face the 21st century. They all agree that the multimedia way is an interesting and fascinating way of learning to satisfy their needs. Above all, it helps lighten their drudgery in the classroom. They feel other subjects taught by other teachers should be treated in the same fashion. A multimedia approach to education is impossible without the advent of hi-tech computers, of which multi functions are integrated into a unified system, i.e., a personal computer. If you have computer-phobia, make quick friends with it; the sooner, the better. It can be a wonderful assistant to you. It is the Internet that I pay close attention to in conjunction with the multimedia approach to English education. Via e-mail system, I encourage my students to write to me in English. I encourage them to enjoy chatting with people all over the world. I also encourage them to visit the sites where they offer study courses in English conversation, vocabulary, idiomatic expressions, reading, and writing. I help them search any subject they want to via World Wide Web. Some day in the near future it will be the hub of learning for everybody. It will eventually free students from books, teachers, libraries, classrooms, and boredom. I will keep exploring better ways to give satisfying instructions to my students who deserve my entertainment.

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Lipoprotein and Lipid Abnormalities in Uremic Children with Maintenance Dialysis (투석 치료중인 만성 신부전 소아에서의 지질 및 지질단백 이상)

  • Kim Jung-Sue;Song Jung-Han;Park Hye-Won;Cheong Hae-Il;Kim Jin-Q;Choi Yong;Ko Kwang-Wook
    • Childhood Kidney Diseases
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    • 제1권2호
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    • pp.109-116
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    • 1997
  • Purpose : Chronic renal failure is often accompanied by severe dyslipidemia, a known risk factor for cardiovascular disease. Lipoprotein(a) [Lp(a)] has recently been characterized as a risk factor for atherosclerosis and thrombosis. Cardiovascular disease is the leading cause of death in adult patients on dialysis. However, there are only limited data available concerning risk factors for atherosclerosis in uremic children. We have measured serum levels of lipids, lipoproteins, apolipoproteins and Lp(a) in uremic children with maintenance dialysis. Methods : Ten uremic children with hemodialysis (HD) and 14 with peritoneal dialysis (PD) in our dialysis unit were included in this study. The mean age of HD patients was $162{\pm}59$ months and the male to female ratio was 7:3. The mean age and sex ratio of PD patients were $123{\pm}63$ months and 6:8, respectively. The levels of cholesterol, triglyceride, lipoproteins, apolipoproteins and Lp(a) were measured from serum sampled after 14 hours of fasting. The normal control levels were cited from 2 articles presenting the normal blood lipid and lipoprotein levels of primary school and middle school children in Korea. Results : There was no difference in age, sex ratio, body mass index and duration of dialysis between the HD and the PD group. The serum concentration of the cholesterol, triglyceride and apolipoprotein B were significantly elevated in dialysis patients compared with normal subjects. The serum level of Lp(a) was significantly elevated in only PD group. The serum Lp(a) level was below 30 mg/dl in 13 and above 30 mg/dl in 11 patients. The serum albumin level was significantly decreased in high Lp(a) group than in low Lp(a) group. Conclusion : The uremic children receiving dialysis reveal abnormal serum lipid and lipoprotein profiles. These results suggest that they have a higher risk for coronary heart disease, although there has been no clinical evidence of coronary heart disease at present. A long-term follow-up study of these children to clarify the suggestion should be started now.

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Early Changes after Death of Plaice, Paralichthys olivaceus Muscle -2. Temperature Dependency on Physicochemical and Rheological Properties- (넙치(Paralichthys olivaceus)육의 사후 조기 변화 -2. 물리 화학적 및 물성적 특성의 온도 의존성-)

  • CHO Young-Je;KIM Yuck-Yong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • 제26권1호
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    • pp.1-7
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    • 1993
  • To clarify the effect of storage temperature on the physicochemical and rheological properties of plaice, Paralichthys olivaceus muscle, the changes in IMP accumulation rates, rigor index, breaking strength and K-value of muscle during storage at $0^{\circ},\;5^{\circ}C$ and $10^{\circ}C$ were studied. The maximum speed and content of IMP accumulation were showed in sample stored at $0^{\circ}C$ among the all samples. The content and time reached around the maximum IMP accumulation for each samples were $6.94{\mu}mole/g$ and 30hrs for samples stored at $0^{\circ}C,\;6.30{\mu}mole/g$ and 31.5hrs for $5^{\circ}C$ samples and $5.40{\mu}mole/g$ and 45hrs for $10^{\circ}C$ samples, respectively. Values of breaking strength in sample stored at $5^{\circ}C$ increased rapidly than samples at $0^{\circ}C$ showed maximum values after 10hrs. However, In case of fresh flesh stored at $10^{\circ}C$, there was no increase of breaking strength during storage. The breaking strength was not closely related with rigor index. The times reached around $5\%$ K-value which is representative excellent freshness index of sashimi were 14hrs for samples stored at $0^{\circ}C$, 13hrs for $5^{\circ}C$ samples and 4hrs for $10^{\circ}C$ samples. From the results above, it was suggested that the storage at low temperature($10^{\circ}C{\sim}5^{\circ}C$) was effective in increase the IMP contents and breaking strength, and maintenance the high-freshness of fresh plaice flesh at early periods after death.

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A Study on Recovery from Potentially Lethal Damage Induced by $\gamma-Irradiation$ in Plateau-phase Vero Cells in vitro (평형기의 Vero세포계에서 방사선($\gamma$-선) 조사 후 발생한 잠재치사 손상의 회복에 관한 연구)

  • Kim, Il-Han;Choi, Eun-Kyung;Ha, Sung-Whan;Park, Charn-Il;Cha, Chang-Yong
    • Radiation Oncology Journal
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    • 제6권1호
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    • pp.1-11
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    • 1988
  • Recovery from potentially lethal damage (PLDR) after irradiation was studied in plateau-phase culture of Vero cells in vitro. Unfed plateau-phase cells were irradiated with dose of 1 to 9Gy using Cs-137 irradiator. Cells then were incubated again and left in situ for 0, 1, 2, 3, 4, 5, 6, and 24 hours and then were trypsinized explanted, and subcultured in fresh RPMI-1640 media containing $0.33\%$ agar. Cell survival was measured by colony forming ability. An adequate number of heavily irradiated Vero cells were added as feeder cells to make the total cell number constant in every culture dish. As the postirradiation in situ incubation time increased, surviving fraction increased by PLDR. The rate of PLDR was so rapid that increased surviving fraction reached saturation level at 2 to 4 hours after in situ incubation. As the radiation dose increased, the rate of PLDR fastened and the magnitude of increased surviving fraction at saturation level by PLOR also increased. In analysis of cell survival curve fitted to the linear-quadratic model, the linear inactivation coefficient $(\alpha)$ decreased largely and reached nearly to zero but the quadratic inactivation coefficient $(\beta)$ increased minimally by increment of postirradiation in situ incubation time. So PLDR mainly affected the damage expressed as $\alpha$, In the multitarget model, significant change was not obtained in $D_0\;but\;in D_q$. Therefore, shoulder region in cell survival curve was mainly affected by PLDR and terminal slope was not influenced at all. And dose-modifying factor by PLDR was relatively higher in shoulder region, that is, in low dose area below 3 Gy.

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The Effect of the Pain on the TMJ and Masticatory Muscles to Tension-type Headache (측두하악관절과 저작근의 통증이 긴장성 두통에 미치는 영향)

  • Kim, Jin-Suk;Auh, Q-Schick;Lee, Jin-Yong;Hong, Jung-Pyo;Chun, Yang-Hyun
    • Journal of Oral Medicine and Pain
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    • 제31권4호
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    • pp.327-335
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    • 2006
  • Generally, Tension-Type Headache(TTH) patients exhibit muscle pain, but can also have TMJ pain, which includes mouth opening limitation or joint sounds. The purpose of our study is to observe the clinical pain characteristics between TTH patients with muscle pain and TMJ pain. One hundred sixty-seven patients were diagnosed with TTH according to the questionnaires based on the International Headache Society's proposal on the diagnostic criteria of TTH. The patients were classified into three group; arthralgia group (18 patients), myalgia group (50 patients) and arthromyalgia group (99 patients). TTH patients with pericranial muscle pain were classified in the myalgia group. TTH patients with temporal region pain were classified in the arthralgia group. TTH patients with both types of pain were classified in the arthromyalgia group. The parameters in the diagnostic criteria such as quality, intensity, laterality of pain, and aggravation due to physical activities were compared among the three groups. 1. There were no significant differences in the quality of pain among the three groups. 2. There were no significant differences in the intensity of pain among the three groups. 3. There were no significant differences in the laterality of pain among the three groups. 4. A higher percentage of patients in the arthromyalgia group experienced headaches that were aggravated due to physical activity (p=0.03) compared to the other groups. The results of this study show that TTH patients with both arthralgia (TMJ pain) and myalgia (pericranial muscle pain) are more aggravated by physical activity than TTH patients with either one.

CHANGE OF TASTE PREFERENCE AND TASTE BUD AFTER UNILATERAL LINGUAL NERVE TRANSECTION IN RAT (백서 편측 설신경 손상 후 미각 및 설유두의 변화에 대한 연구)

  • Kim, Yoon-Tae;Jeon, Seung-Ho;Yeom, Hak-Ryol;Kang, Jin-Han;Ahn, Kang-Min;Kim, Sung-Min;Jahng, Jeong-Won;Park, Kyung-Pyo;Lee, Jong-Ho
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제31권6호
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    • pp.515-525
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    • 2005
  • Purpose of study: Lingual nerve damage can be caused by surgery or trauma such as physical irriatation, radiation, chemotherapy, infection and viral infection. Once nerve damage occurred, patients sometimes complain taste change and loss of taste along with serious disturbance of tongue. The purpose of this study was to evaluate the effects of unilateral lingual nerve transection on taste as well as on the maintenance of taste buds. Materials & Methods: Male Sprague-Dawley rats weighing 220-250g received unilateral transection of lingual nerve, subjected to the preference test for various taste solutions (0.1M NaCl, 0.1M sucrose, 0.01M QHCl, or 0.01M HCl) with two bottle test paradigm at 2, 4, 6, or 8 weeks after the operation. Tongue was fixed with 8% paraformaldehyde. After fixation, they were observed with scanning electron microscope(JSM-$840A^{(R)}$, JEOL, JAPAN) and counted the number of the dorsal surface of the fungiform papilla for changes of fungiform papilla. And, Fungiform papilla were obtained from coronal sections of the anterior tongue(cryosection). After cryosection, immunostaining with $G{\alpha}gust$(I-20)(Santa Cruz Biotechnology, USA), $PLC{\beta}2$(Q-15)(Santa Cruz Biotechnology, USA), and $T_1R_1$(Alpha Diagnostic International, USA) were done. Immunofluorescence of labeled taste bud cells was examined by confocal microscopy(F92-$300^{(R)}$, Olympus, JAPAN). Results: The preference score for salty and sweet tended to be higher in the operated rats with statistical significance, compared to the sham rats. Fungiform papilla counting were decreased after lingual nerve transaction. In 2 weeks, maximum differences occurred. Gustducin and $T_1R_1$ expressions of taste receptor in 2 and 4 weeks were decreased. $PLC{\beta}2$ were not expressed in both experimental and control group. Conclusion: This study demonstrated that the taste recognition for sweet and salty taste changed by week 2 and 4 after unilateral lingual nerve transection. However, regeneration related taste was occurred in the presence of preserving mesoneurial tissue and the time was 6 weeks. Our results demonstrated that unilateral lingual nerve damage caused morphological and numerical change of fungiform papilla. It should be noted in our study that lingual nerve transection resulted in not only morphological and numerical change but also functional change of fungiform papillae.

The Effects of Environment-Friendly Diets on the Growth Performance, Nutrient Digestibility, Fecal Excretion, Nitrogen Excretion and Emission Gases in Manure for Growing Pigs (환경친화적인 사료의 급여가 육성돈의 성장 능력, 영양소 소화율, 분 배설량, 분뇨내 질소배설량 및 악취 가스에 미치는 영향)

  • Yoo, J.S.;Cho, J.H.;Chen, Y.G.;Kim, H.J.;Wang, Q.;Hyun, Y.;Ko, T.G.;Park, C.S.;Kim, I.H.
    • Journal of Animal Science and Technology
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    • 제49권4호
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    • pp.491-500
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    • 2007
  • Two experiments were used to determine the effects of environment-friendly diets on growth performance, fecal excretion, nitrogen excretion and emission gases in manure for growing pigs. In experiment 1, ninety six crossed pigs(Landrace×Yorkshire×Duroc) were allocated into four treatments. Treatments were AME(adequate ME diet, 3,265 kcal/kg), LME(lower ME diet, 3,100 kcal/kg), LME 0.05(lower ME diet+α- galactosidase & β-mannanase 0.05%) and LME 0.10(lower ME diet+α-galactosidase & β-mannanase 0.10%). Pigs fed AME diet had lower ADFI(Average Daily Feed Intake) than pigs fed other diets(p<0.05). DM(Dry Matter) digestibility in pigs fed AME and LME 0.10 diets had greater than pigs fed LME diet(p<0.05). Energy digestibility is higher in pigs fed AME and LME 0.10 diets than other treatments(p<0.05). In experiment 2, twenty four crossbred pigs(33.71 kg average BW) were used in a 14-d metabolism experiment. The pigs were housed in individual cages equipped with plastic bed flooring. Treatments were CP(Crude protein) 18% without Bacillus sp., CP 18% diet+Bacillus sp. 0.05%, CP 14% without Bacillus sp. and CP 14% diet+Bacillus sp. 0.05%. Nitrogen intake was higher for CP 18% diets than CP 14% diets(p<0.05). DM, N(Nitrogen) and energy digestibility were affected by probiotics(p<0.05). With the high CP in diets, Energy and N digestibility, urine N percent, urine N excretion and total N excretion were increased significantly compared to low CP in diets(p<0.05). Among the treatments, DM and N digestibilities, feces N excretion, N absorption were decreased significantly(p<0.05), however, feces excretion, feces N, urine N percent, urine N excretion and total N excretion were increased significantly(p<0.05) when pigs fed without probiotics diets compare to pigs fed with probiotics diets. DM and N digestibility, feces excretion, feces N excretion, urine N percent, urine N excretion, total N excretion, N absorption and N adsorption ratio were CP×probiotic interactions in p<0.05. Ammonia(p<0.01) and H2S(p<0.05) in manure were lower in CP 14% diets than CP 18% diets. Also, ammonia and H2S in manure were CP×probiotic interactions in p<0.05. In conclusion, low energy and reduction of CP dietary added enzyme and probiotics improved nutrient digestibility and reduced odors emission in manure for growing pigs.

Metabolites profiling and hypolipidemic/hypocholesterolemic effects of persimmon (Diosyros kaki Thumb.) by different processing procedures: in vitro and in vivo studies (제조방법에 따른 떫은감 (Diosyros kaki Thumb.)의 대사체 프로파일링과 중성지질/콜레스테롤 대사 관련 유전자발현 연구 : in vitro 및 in vivo 연구)

  • Park, Soo-Yeon;Oh, Eun-Kyung;Lim, Yeni;Shin, Ji-Yoon;Jung, Hee-Ah;Park, Song-Yi;Lee, Jin Hee;Choe, Jeong-Sook;Kwon, Oran
    • Journal of Nutrition and Health
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    • 제51권4호
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    • pp.275-286
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    • 2018
  • Purpose: Our previous study demonstrated that persimmon (Diospyros kaki Thumb.) at different stages of ripening provided different protective effects against high-fat/cholesterol diet (HFD)-induced dyslipidemia in rats. In this study, we compared the metabolites profile and gene expressions related to triglyceride (TG)/cholesterol metabolism in vitro and in vivo after treating with persimmon water extracts (PWE) or tannin-enriched persimmon concentrate (TEP). Methods: Primary and secondary metabolites in test materials were determined by GC-TOF/MS, UHPLC-LTQ-ESI-IT-MS/MS, and UPLC-Q-TOF-MS. The expression of genes related to TG and cholesterol metabolism were determined by RT-PCR both in HepG2 cells stimulated by oleic acid/palmitic acid and in liver tissues obtained from Wistar rats fed with HFD and PWE at 0, 150, 300, and 600 mg/d (experiment I) or TEP at 0, 7, 14, and 28 mg/d (experiment II) by oral gavage for 9 weeks. Results: PLS-DA analysis and heatmap analysis demonstrated significantly differential profiling of metabolites of PWE and TEP according to processing of persimmon powder. In vitro, TEP showed similar hypolipidemic effects as PWE, but significantly enhanced hypocholesterolemic effects compared to PWE in sterol regulatory element-binding protein 2 (SREBP2), HMG-CoA reductase (HMGCR), proprotein convertase subtilisin/kexin type 9 (PCSK9), cholesterol $7{\alpha}-hydroxylase$ (CYP7A1), and low density lipoprotein receptor (LDLR) gene expression. Consistently, TEP and PWE showed similar hypolipidemic capacity in vivo, but significantly enhanced hypocholesterolemic capacity in terms of SREBP2, HMGCR, and bile salt export pump (BSEP) gene expression. Conclusion: These results suggest that column extraction after hot water extraction may be a good strategy to enhance tannins and long-chain fatty acid amides, which might cause stimulation of hypocholesterolemic actions through downregulation of cholesterol biosynthesis gene expression and upregulation of LDL receptor gene expression.

Sorption Efficiency of the Bamboo Charcoal to Remove the Cesium in the Contaminated Water System (오염수계 내 세슘 제거를 위한 대나무 활성탄의 흡착효율 규명)

  • Ahn, Joungpil;Lee, Minhee
    • Economic and Environmental Geology
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    • 제51권2호
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    • pp.87-97
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    • 2018
  • The cesium (Cs) removal from the contaminated water system has been considered to be difficult because the cesium likes to exist as soluble phases such as ion and complexes than the solid in water system. Many researches have focused on developing the breakthrough adsorbent to increase the cesium removal efficiency in water. In this study, the laboratory scale experiments were performed to investigate the feasibility of the adsorption process using the bamboo charcoal for the Cs contaminated water system. The Cs removal efficiency of the bamboo charcoal were measured and the optimal adsorption conditions were determined by the adsorption batch experiments. Total 5 types of commercialized bamboo charcoals in Korea were used to identify their surface properties from SEM-EDS and XRD analyses and 3 types of bamboo charcoals having large specific surface areas were used for the adsorption batch experiment. The batch experiments to calculate the Cs removal efficiency were performed at conditions of various Cs concentration (0.01 - 10 mg/L), pH (3 - 11), temperature ($5-30^{\circ}C$), and adsorption time (10 - 120 min.). Experimental results were fitted to the Langmuir adsorption isotherm curve and their adsorption constants were determined to understand the adsorption properties of bamboo charcoal for Cs contaminated water system. From results of SEM-EDS analyses, the surfaces of bamboo charcoal particles were composed of typical fiber structures having various pores and dense lamella structures in supporting major adsorption spaces for Cs. From results of adsorption batch experiments, the Cs-133 removal efficiency of C type bamboo charcoal was the highest among those of 3 bamboo charcoal types and it was higher than 75 % (maximum of 82 %) even when the initial Cs concentration in water was lower than 1.0 mg/L, suggesting that the adsorption process using the bamboo charcoal has a great potential to remove Cs from the genuine Cs contaminated water, of which Cs concentration is low (< 1.0 mg/L) in general. The high Cs removal efficiency of bamboo charcoal was maintained in a relatively wide range of temperatures and pHs, supporting that the usage of the bamboo charcoal is feasible for various types of water. Experimental results were similar to the Langmuir adsorption model and the maximum amount of Cs adsorption (qm:mg/g) was 63.4 mg/g, which was higher than those of commercialized adsorbents used in previous studies. The surface coverage (${\theta}$) of bamboo charcoal was also maintained in low when the Cs concentration in water was < 1.0 mg/L, investigating that the Cs contaminated water can be remediated up with a small amount of bamboo charcoal.

Effect of Low-Level Laser to Oral Microorganisms (저출력 레이저가 구강미생물에 미치는 영향)

  • Yoon, In-Jong;Auh, Q-Schick;Chun, Yang-Hyun;Hong, Jung-Pyo
    • Journal of Oral Medicine and Pain
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    • 제35권1호
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    • pp.31-39
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    • 2010
  • This study is to observe the bacteriocidal effect of the Low Level Laser (LLL) against oral microorganisms which are related to the occurrence of periodontal diseases and oral malodors. The Porphyromonas gingivalis 2561 (P. gingivalis 2561) and Prevotella intermedia (Pr. intermedia) were treated with photosensitizing substance-toluidine blue O (TBO; C.I. 52040) and then radiated with the LLL which has 650nm wavelength for 1, 2, 3 and 5mins. continuously upon varying distances of 1, 2 and 3cm for each experimental groups. The results are as follows; 1. The P. gingivalis 2561 which was treated with TBO and then radiated with LLL at a distance of 3cm for 1min. showed 99.99% higher antibacterial effect in comparison to the experimental group treated only with TBO. 2. The Pr. intermedia which was treated with TBO and then radiated with LLL at a distance of 3cm for 1min. showed 99.8% higher antibacterial effect in comparison to the experimental group treated only with TBO. 3. The bacteriocidal effect of the P. gingivalis 2561 treated with TBO was found to gradually increase as the radiation time of LLL extended from 1min. to 3min. at 1min. intervals. 4. A slight decrease in bacteriocidal effect of the P. gingivalis 2561 was found as the radiation distance of LLL increased from 1cm to 3cm at 1cm intervals. 5. The bacteriocidal effect of the Pr. intermedia was found to slightly decrease as the radiation distance of LLL increased from 1cm to 3cm at 1cm. intervals. As the results shown above suggest, the bacteriocidal effect of LLL was found to increase as the radiation time extended and the distance shortened. Moreover, even the experimental group radiated with LLL at 3cm distance for 1min. which showed the lowest level of bacteriocidal effect, was found to have 99.8% higher bacteriocidal effect than the experimental group which was treated only with TBO and, therefore, this clearly shows the bacteriocidal effect of LLL against oral microorganisms. Thus, the use of LLL is thought to become very useful for suportive treatment for periodontitis and implantitis, and controlling oral malodors as long as it is used within the limits where there is no side effect.