• 제목/요약/키워드: $^{232}Th$

검색결과 161건 처리시간 0.021초

고대 이집트인들의 원의 구적과 직각삼각형의 인식 (Squaring the Circle and Recognizing Right Triangles of Ancient Egyptians)

  • 박민구;박제남;홍경희
    • 한국수학사학회지
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    • 제30권4호
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    • pp.221-232
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    • 2017
  • In this paper, we discuss how ancient Egyptians find out the area of the circle based on $\ll$Ahmose Papyrus$\gg$. Vogel and Engels studied the quadrature of the circle, one of the basic concepts of ancient Egyptian mathematics. We look closely at the interpretation based on the approximate right triangle of Robins and Shute. As circumstantial evidence for Robbins and Shute's hypothesis, Egyptians prior to the 12th dynasty considered the perception of a right triangle as examples of 'simultaneous equation', 'unit of length', 'unit of slope', 'Egyptian triple', and 'right triangles transfer to Greece'. Finally, we present a method to utilize the squaring the circle by ancient Egyptians interpreted by Robbins and Shute as the dynamic symmetry of Hambidge.

Clinical Application of Autologous Platelet-Rich Plasma (PRP) on Delayed Wound Healing of a Dog with Burns

  • Lee, Shinho;Cheong, Jongtae;Lee, Joo-Myoung
    • 한국임상수의학회지
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    • 제35권5호
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    • pp.229-232
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    • 2018
  • A 9-year-old intact female Poodle (weighing 3.6 kg) was presented for the treatment of a partial and full thickness burn that covering 45% of body including bilateral thigh and sacrolumbar region. Autologous platelet-rich plasma (PRP) stimulates angiogenesis, promoting vascular in-growth and fibroblast proliferation. On the unrecovered right thigh of the dog, autologous PRP was injected into the lesion after application of micro-needles. For macroscopic evaluation digital, photographs were taken from wounds at days 0, 3, 5, 13, 21, and 28. On the $3^{rd}$ day after PRP application, epithelialization was accelerated. Application of autologous PRP accelerated wound-healing rate and healing time in full thickness burns as well as secondary complications originating from unrecovered wounds. The delayed lesion was completely healed on the $28^{th}$ day by autologous PRP treatment. In human, PRP was increasingly used in the treatment of a variety of soft tissue in the management of chronic non-healing wounds. This study has shown that PRP treatment can be a valuable and effective aid on intractable wound healing in the dog with burns.

Estimation of natural radionuclide and exhalation rates of environmental radioactive pollutants from the soil of northern India

  • Devi, Vandana;Chauhan, Rishi Pal
    • Nuclear Engineering and Technology
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    • 제52권6호
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    • pp.1289-1296
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    • 2020
  • The estimation of radioactivity level is vital for population health risk assessment and geological point of view and can be evaluated as rate of exhalation and source concentration (226Ra, 232Th and 40K). The present study deals with the soil samples for investigation of radionuclides content and exhalation rates of radon -thoron gas from different sites in northern Haryana, India. Absorbed dose and associated index estimated in the present study are the measures of environmental radioactivity to inhalation dose. Effective doses received by different tissues and organs by considering different occupancy and conditions are also measured. Exhalation rates of radon and thoron are measured with active scintillation monitors based on alpha spectroscopy namely scintillation radon (SRM) and thoron (STM) monitors respectively. Sample height was optimized before measurement of thoron exhalation rate using STM. Average values of radon and thoron exhalation are found 16.6 ± 0.7 mBqkg-1h-1 and 132.1 ± 2.6 mBqm-2s-1 respectively. Also, a simple approach was also adopted, to evaluate the thoron exhalation which accomplished a lot of challenges, the results are compared with the data obtained experimentally. The study is useful in the nationwide mapping of radon and thoron exhalation rates for understanding the environmental radioactivity status.

조선전기 고문헌에 수록된 식품저장법에 대한 문헌고찰 (Review of Literature on Food Preservation of the Early Joseon Dynasty)

  • 김명준;차경희;정혜정
    • 한국식생활문화학회지
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    • 제35권1호
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    • pp.28-54
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    • 2020
  • This study aims to investigate the food preservation methods adopted by the Joseon Dynasty, which existed before the 17th century. A total of 232 food preservation methods were discovered in 25 books, and could be classified by their targeted food types: vegetables (84), sea foods (60), meats (41), fruits (37), and others (10). Depending on the preservation method applied, they are classified as food drying, soaking, mud cellar preservation, and other preservation. Food drying is further classified into 8 sub-types: drying, sun-drying, shadow-drying, wind-drying, dry heat, combined drying, smoking, and others. Soaking could be sub-divided into using salt, ash, dry sand, bran, fermented paste, wet distillers grains, oil, and others. Mud cellar preservation is sub-classified into installing shelf inside the mud cellar, making the mud cellar for food preservation, and making hole or underground tunnel for food preservation. Other food preservation methods include minimizing moisture loss by applying beeswax on a section of the vegetable stem, and cutting the vegetables or fruits with their branches and leaves for food preservation.

고혈압과 당뇨병 환자의 관리적 특성이 우울과 자살생각에 미치는 영향 (The Effect of Their Sense of Depression and Suicidal Thinking for Managerial Characteristics in Hypertense and Diabetic Patients)

  • 박소희;황병덕
    • 보건의료산업학회지
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    • 제7권4호
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    • pp.221-232
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    • 2013
  • This study aims to analyze the effect of hypertense, diabetic patients, managerial characteristics on their depression and suicidal thinking. Thus, this study selected 6,217 adults over the age of 19 from the 5th first-year data of Korean National Health and Nutrition Examination Survey conducted by KCDC(Korea Centers for Disease Control and Prevention) in 2010. As factors having effect on their suicidal thinking, unmarried patients(p=.000), middle school(p=.045), high school(p=.015), college and higher(p=.018), medicare(p=.045), hypertense(p=.042), exercise walking irregularly(p=.021), sense of depression(p=.035) showed a higher rate of suicidal thinking which were found to be statistically significant variables. Hypertense show a higher rate of suicidal thinking than normal people. Accordingly, it is necessary not only to pay attention to establishing plans to provide Hypertense and Diabetic patients with medical treatments, but to have more concern about their mental health so that they may be provided with a political support future.

상관관계 해석을 고려한 온 더 머신 자동측정 시스템 (Measuring Automation System for Analysis of Dimensional Reationships On the Machine)

  • 정성종
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 1996년도 춘계학술대회 논문집
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    • pp.183-187
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    • 1996
  • On the machine measuring system composed of touch trigger probes, a DNC module, a CMM module, an analysis module and a man-machine interface unit was developed. Measuring accuracy is affected by working accuracy of the on the machine measuring system. The working accuracy of the system is due to geometric errors of th machine tool, servo errors of feed drives and positioning errors of probes. In order to compensate for the measuring errors due to the working accuracy, a calibration module was developed. The measuring automation system was realized with the on the machine measuring system and an IBM-PC on the machine center through a RS-232C. It turns the machining machine (CMM). The system is used for dimensional checking of machined components. initial job setup, part identification, identification of machining errors due to deflection and wear of tools. cutter run out, and calibration of machine tools. A horizontal machining center equipped with FANUC OMC wre used for verification of the system. The validity and reliability of the system. The validity and reliability of the system were confirmed through a series of experiments with gage blocks, ring gages, comparison measurement with a commercial CMM, and so on.

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Determination of indoor doses and excess lifetime cancer risks caused by building materials containing natural radionuclides in Malaysia

  • Abdullahi, Shittu;Ismail, Aznan Fazli;Samat, Supian
    • Nuclear Engineering and Technology
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    • 제51권1호
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    • pp.325-336
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    • 2019
  • The activity concentrations of $^{226}Ra$, $^{232}Th$, and $^{40}K$ from 102 building materials samples were determined using a high-purity germanium (HPGe) detector. The activity concentrations were evaluated for possible radiological hazards to the human health. The excess lifetime cancer risks (ELCR) were also estimated, and the average values were recorded as $0.42{\pm}0.24{\times}10^{-3}$, $3.22{\pm}1.83{\times}10^{-3}$, and $3.65{\pm}1.85{\times}10^{-3}$ for outdoor, indoor, and total ELCR respectively. The activity concentrations were further subjected to RESRAD-BUILD computer code to evaluate the long-term radiation exposure to a dweller. The indoor doses were assessed from zero up to 70 years. The simulation results were $92{\pm}59$, $689{\pm}566$, and $782{\pm}569{\mu}Sv\;y^{-1}$ for indoor external, internal, and total effective dose equivalent (TEDE) respectively. The results reported were all below the recommended maximum values. Therefore, the radiological hazards attributed to building materials under study are negligible.

Accumulation and distribution of nutrients, radionuclides and metals by roots, stems and leaves of plants

  • Huynh Truc Phuong;Vu Ngoc Ba;Bui Ngoc Thien;Loan Truong Thi Hong
    • Nuclear Engineering and Technology
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    • 제55권7호
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    • pp.2650-2655
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    • 2023
  • In the process of growth and development, plants not only absorb essential nutritional elements, but also absorb radioactive and non-essential elements from the environment, and their distribution varies in different parts of the plant. In this study, neutron activation analysis and gamma spectrometry were performed on stems, roots, and leaves of vegetables. The results indicate that the accumulation of radionuclides and multi-elements depends on the plant type and plant parts. Activity concentrations of 226Ra and 232Th in plants were accumulated in the following order: Roots > Stems > Leaves. The highest concentrations of 40K and 210Pb were observed in the stems and leaves of plants, respectively. Essential nutrient requirements of plants are in the following order: K > Ca > Mg > Fe > Zn > Mn. Among the nonessential metals, the concentration of Na in the vegetable sample was much greater than those of the other elements. The K/Na ratio in the plant depends on the type of plant and the translocation within the plant.

COVID-19로 인한 온라인 중심 교육에서 간호대학생의 핵심 기본 간호술 수행 자신감에 영향을 미치는 요인 (Factors Affecting the Confidence of Nursing Students in the On-line-Based Education by COVID-19)

  • 차혜경;김한송
    • 디지털융복합연구
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    • 제20권1호
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    • pp.459-469
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    • 2022
  • 본 연구는 COVID-19로 인한 온라인 중심 교육에서 간호대학생의 핵심 기본 간호술 수행자신감 향상을 위한 교수법 개발을 위한 기초자료를 제공하고자 시도되었다. C시에 소재한 N대학 간호학과 146명이 연구에 참여하였다. 수집된 자료는 SPSS 23.0 통계 프로그램을 사용하여 기술통계, t-test, ANOVA 및 Duncan test를 활용한 차이 분석, 상관관계분석 및 다중회귀분석을 시행하였다. 연구 결과, 대상자의 핵심 기본 간호술 수행 자신감은 자기 주도 학습준비(r=.368, p<.001), 학습 동기의 하위영역인 내재적 동기(r=.232, p=.005), 외재적 동기(r=.344, p<.001), 과제 가치(r=.237, p=<.001), 학습통제신념(r=.262, p=<.001), 자기효능감(r=.443, p<.001)과 유의한 양의 상관관계가 있었다. 간호대학생의 핵심 기본 간호술 수행자신감 영향 요인으로는, 4학년(β=0.413, p<.001), 학습 동기의 하위 영역 중 외재적 동기(β=0.307, p<.001), 자기효능감(β=0.316, p=.005)이었으며, 설명력은 35.8%였다(F=8.354, p<.001). 본 연구결과를 토대로 핵심 기본 간호술 수행자신감 증진을 위해서 간호대학생의 외재적 동기, 자기효능감을 높일 수 있는 다양한 교수법의 개발 및 적용이 필요하며, 이는 핵심 기본 간호술 수행자신감 향상을 위한 효율적인 온라인 중심의 간호교육 전략 마련에 기초자료가 될 것이다.

Lysine 결핍에 따른 섭식반응과 뇌의 역할 (The Role of Brain and Feeding Response on Lysine Devoid Diet)

  • 김창혁
    • Journal of Animal Science and Technology
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    • 제44권2호
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    • pp.221-232
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    • 2002
  • 시험은 사료내 필수아미노산 결핍이 rat의 사료섭취량과 혈액 및 뇌내 전이상엽피질(PPC)의 유리아미노산 농도 변화에 미치는 영향을 조사하여 뇌내 섭식조절 메카니즘을 구명하고자 하였다. 시험에 이용된 모든 사료의 질소원은 순수 아미노산 혼합물을 이용하였으며, 질소수준은 15%로 하였다. 사료는 하루 6시간 동안 섭취하도록 훈련을 시켰으며(17:00-21:00, meal feeding method), 사료섭취량과 증체량은 사료급여 7일째부터 매시간 측정하였다. 실험 1에서 사료섭취량과 증체량을 사료급여 후 매시간 측정하였으며, 혈액 및 PPC의 아미노산 농도는 사료급여 11일째의 0, 1, 2, 3, 6시간 후에 관찰하였다. 실험 2에서는 complete diet에서 11일째에 lysine 결핍사료로 교체하여 사료섭취량, 증체량 및 혈액 및 PPC의 아미노산 농도는 실험 1과 동일하게 측정하였다. 실험 1에서 complete diet 급여에 따른 사료섭취량은 7일째부터 일일섭취량(15g/day)을 충족하였다. 또한 11일째의 혈액 및 뇌의 유리 아미노산 농도는 사료급여 한시간 후에 증가하였으나, 그 후에는 일정한 수준을 유지하였다. 반면, 실험 2에서는 complete diet에서 lysine 결핍사료로 교체함에 따른 사료섭취량은 급격하게 감소하였고(P$<$0.05), 혈액 및 PPC의 유리 lysine 농도는 lysine 결핍사료 급여 2시간 후에 유의적(p$<$0.05)으로 감소하였으며, 누적 사료섭취량은 사료급여 4시간째 유의적으로 감소하였다(p$<$0.05). 따라서 이상의 결과로 보아 아미노산 결핍사료 섭취에 따른 혈액과 PPC의 해당 아미노산의 농도 감소는 사료섭취량의 감소에 비하여 빠르게 반응하였고, 이러한 결과로 미루어 사료중 아미노산 결핍에 반응하는 부위의 일부분으로 뇌내 PPC가 직접적인 관여를 한다고 판단된다.