453 research outputs found
Langmuir monolayers of Co nanoparticles and their Patterning by microcontact printing
No full textIn this paper, we describe an easy and reliable method for the production of patterned monolayers of Co nanoparticles. A two-dimensional monolayer of Co nanoparticles is fabricated by spreading a nanoparticle solution over an air-water interface and then transferring it to a hydrophobic substrate by using the Langmuir-Blodgett (LB) method. Transmission electron microscopy (TEM) was used to show that, with increasing surface pressure, the Co nanoparticles become well-organized into a Langmuir monolayer with a hexagonal close-packed structure. By controlling the pH of the subphase, it was found that a monolayer of Co nanoparticles with long-range order could be obtained. Further, by transferring the Langmuir monolayer onto a poly(dimethoxysilane) (PDMS) mold, the selective micropatterning of the Co nanoparticles could be achieved on a patterned electronic circuit. The electronic transport properties of the Co nanoparticles showed the ohmic I-V curve.KOSEF through the Center for Nanotubes and Nanostructured Composites, the Brain Korea 21 Project, KRF (Grant R02-2004-000-10096-0), NCRC (Grant R15-2004-024-02002-0), the National R&D Project for Nano Science and Technology, the National R&D for Cancer Control (0320250-2), Korea Health 21R&D(0405-MN01-0604-0007), AOARD(FA520904P0406)
What do African Citizens of Different Income Levels think of Chinese Investment? 2015-2019 A study of three countries in Africa
No full textThis study focused on determining the relationship between occupation, education and perception on Chinese investment in Kenya, Senegal and Nigeria.
It used a combination of qualitative and quantitative research to determine conclusions. The qualitative research focused on interviews and personal one on one interactions with Africans. The author used publicly available Afrobarometer data for the quantitative study.
The results of the study indicate that there is a correlation between occupation and perception on Chinese influence for all three countries. However, there was no conclusive evidence that there was correlation between education and perception of Chinese influence.
Readers for this text are: Dr. Lewis, Dr. Cheon and Mr. Gregoire
Magnetic superlattices and their nanoscale phase transition effects
No full textThe systematic assembly of nanoscale constituents into highly ordered superlattices is of significant interest because of the potential of their multifunctionalities and the discovery of new collective properties. However, Successful observations of such superlattice-associated nanoscale phenomena are still elusive. Here, we present magnetic superlattices of Co and Fe3O4 nanoparticles with multidimensional symmetry of either AB (NaCl) or AB(2) (AlB2). The discovery of significant enhancement (approximate to 25 times) of ferrimagnetism is further revealed by forming previously undescribed superlattices of magnetically soft-hard Fe3O4@COFe2O4 through the confined geometrical effect of thermally driven intrasuperlattice phase transition between the nanoparticulate components.Nano Science and Technology Grant
M1-0213-12-0001, National Core Research Center Grant R15-2004-024-02002-0, R & D Program of Fusion Strategies for Advanced Technologies Grant M1-0326-11-0006, NCI Center for Nanotechnology Excellence,
Center for Nanotubes and Nanostructured Composites, and the BK 21 Project
High-order synchronization of hair cell bundles
No full textAuditory and vestibular hair cell bundles exhibit active mechanical oscillations at natural frequencies that are typically lower than the detection range of the corresponding end organs. We explore how these noisy nonlinear oscillators mode-lock to frequencies higher than their internal clocks. A nanomagnetic technique is used to stimulate the bundles without an imposed mechanical load. The evoked response shows regimes of high-order mode-locking. Exploring a broad range of stimulus frequencies and intensities, we observe regions of high-order synchronization, analogous to Arnold Tongues in dynamical systems literature. Significant areas of overlap occur between synchronization regimes, with the bundle intermittently flickering between different winding numbers. We demonstrate how an ensemble of these noisy spontaneous oscillators could be entrained to efficiently detect signals significantly above the characteristic frequencies of the individual cells. © The Author(s) 20161
Cerostoma xenicopis Meyrick 1938
No full textCerostoma xenicopis Meyrick, 1938: 23 [Fig. 6]. A lectotype of Cerostoma xenicopis Meyrick (in MGAB) was designated by Popescu-Gorj (1992) but this specimen is now missing. The first author (JCS) examined a male syntype of Cerostoma xenicopis from the BMNH’s collection (Fig. 6). The specimen was not dissected because the exposed valvae not covered by expanded lobes of the 8 th abdominal pleura evidently precluded its association with Ypsolophinae and even possibly with Yponomeutoidea. Determination of its taxonomic placement will require eventually dissection of its genitalia.Published as part of Sohn, Jae-Cheon, Ponomarenko, Margarita G., Wu, Chun-Sheng, Han, Hui-Lin & Wang, Xin-Li, 2010, Descriptions of three new species of Ypsolopha Latreille (Lepidoptera: Ypsolophidae) from East Asia, redescription of Y. contractella (Caradja) and a checklist of East Asian Ypsolopha, pp. 22-38 in Zootaxa 2511 on page 34, DOI: 10.5281/zenodo.29440
Megahertz-wave-transmitting conducting polymer electrode for device-to-device integration
No full textThe ideal combination of high optical transparency and high electrical conductivity, especially at very low frequencies of less than the gigahertz (GHz) order, such as the radiofrequencies at which electronic devices operate (tens of kHz to hundreds of GHz), is fundamental incompatibility, which creates a barrier to the realization of enhanced user interfaces and ‘device-to-device integration.’ Herein, we present a design strategy for preparing a megahertz (MHz)-transparent conductor, based on a plasma frequency controlled by the electrical conductivity, with the ultimate goal of device-to-device integration through electromagnetic wave transmittance. This approach is verified experimentally using a conducting polymer, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS), the microstructure of which is manipulated by employing a solution process. The use of a transparent conducting polymer as an electrode enables the fabrication of a fully functional touch-controlled display device and magnetic resonance imaging (MRI)-compatible biomedical monitoring device, which would open up a new paradigm for transparent conductors. © 2019, The Author(s
Binary-state scanning probe microscopy for parallel imaging
No full textScanning probe microscopy techniques, such as atomic force microscopy and scanning tunnelling microscopy, are harnessed to image nanoscale structures with an exquisite resolution, which has been of significant value in a variety of areas of nanotechnology. These scanning probe techniques, however, are not generally suitable for high-throughput imaging, which has, from the outset, been a primary challenge. Traditional approaches to increasing the scalability have involved developing multiple probes for imaging, but complex probe design and electronics are required to carry out the detection method. Here, we report a probe-based imaging method that utilizes scalable cantilever-free elastomeric probe design and hierarchical measurement architecture, which readily reconstructs high-resolution and high-throughput topography images. In a single scan, we demonstrate imaging with a 100-tip array to obtain 100 images over a 1-mm2 area with 106 pixels in less than 10 min. The potential for large-scale tip integration and the advantage of a simple probe array suggest substantial promise for our approach to high-throughput imaging far beyond what is currently possible. © 2022, The Author(s).11Nsciescopu
Study on health education implementation for Korean industrial workers
No full text보건학과/석사[한글]
1957년 대한석탄공사에서 광산근로자들에 대한 건강진단이 실시된 이래 산업보건활동이 시작되었으나, 1976년 진폐증 유병율이 2.3 ∼ 4.9%에 이르고 1978년에 근로자들에 대한 산업보건에 관한 의식조사에서 직업병에 대해 잘 알지도 못하고 들어본 일도 없다는 근
로자가 47%나 된다는 사실은 이들에 대한 보건교육의 필요성을 나타내고 있다. 산업장 근로자들에 대한 보건교육 실시 실태에 대해서는 조사된바 없어 저자는 실태파악과 아울러 기초자료률 수집코저 본 조사를 실시하였다.
조사대상은 산업장의 보건교육을 담당하고 있는 보건관리자 또는 보건관리요원과 이에 준하는 해당직원으로 했으며, 산업장 근로자들에 대한 건강진단을 실시하는 모연구소를 통하여 건강진단과 병행하여 면접조사를 실시하고 전국의 1,000명이상의 기업에는 우편을 통하여 설문을 회수받었다.
조사내용은 기업의 규모, 교육실시 여부. 교육실시시기, 교육의 방법, 교육내용, 미실시의 이유 등이었고 기업의 규모나 유해작업부서의 근로자수별, 교육담당자별. 경영진의 관심도별로의 비교를 실시하였다. 총 자료수는 364건으로 조사결과는 다음과 같다.
1. 보건교육의 실시여부는 기업의 규모가 클수록 유해작업부서의 근로자가 많을수록 경영진의 관심도가 높을수록 교육담당자의 근무년한이 많을수록 실시율이 높아지는 경향을 보였다.
2. 교육의 실시시기는 500명이상의 기업에서는 필요시와 의무실 방문시에, 50명이상 500명미만의 기업에서는 휴식시와 필요시에, 50명미만의 기업에서는 식사시기와 출퇴근시기에 실시하는 경향이 높았다.
3. 교육의 방법에서는 기업의 규모, 경영진의 관심도, 교육담당자에 관계없이 공히 강의식과 인쇄매체이용이 많은 빈도를 보였다.
4. 교육의 내용에 있어서는 기업의 규모나 유해작업부서 근로자수에 관계없이 일반건강 및 질병에 대한 내용과 응급처치가 많은 빈도를 보였다.
5. 교육미실시의 이유로서는 여건의 부적당과 전문인력자원 및 교재부족이 가장 많았다.
Study on Heal th Education Implementation for Korean Industrial Workers
Cheon, Yong Hee
Department of Public Health Graduate School
Yonsei University
(Directed by Professor Moon, Young Han)
Frankly speaking the actual health seroice for industrial workers in Korea was
initiated through the health examination for coal miners on 1957. Thereafter, the
prevalence rate of pneumoconiosis among workers was found out as 2.3-4.9% on 1976.
Looking at health education aspect, 47% of workers responded as they were ignore
about occupational diseases in knowledge, attitude and behavior study for them.
From this fact it is easily emphasized that heal th education activity should be
urgently carried out in the industrial field. Therefore the author tried to plan
and obtain the basic data on health education implementation in the industrial
field in Korea through the sampling survey.
The interview survey was performed for health workers to whom health examination
was carried out by the Institute of Industrial Health, Yonsei University on one
hand, and on the other hand the mailing survey was done for industrial factories in
the country where more than 1,000 workers were working.
The items of survey was consisted of size of the factory, time, methods, contents
of health education and reasons for neglecting health education.
The result of the study are summarized as below.
1. The rate of education implementation was higher as size of industries were
larger, the number of workers working in hazard environment was larger, the
interest of manager was higher, the period of employment of health worker was
longer.
2. The time of education was like below. In the industries employing below 50
workers, when workers go on duty and left one's work site. In the industries
employing more than 50 workers and below 500 workers, when educator feels need and
workers rest. In the industries employing more than 500 workers, when educator
feels need and workers visit health service center.
3. The lecture and printed material were used more frequently in whole industries
as method of education.
4. The general health problem and emergency care were contained more frequently
as the content of health education in whole industries.
5. The reasons for neglecting health education were inappropriate condition,
insufficient manpower and teaching material in more than 50%.
[영문]
Frankly speaking the actual health seroice for industrial workers in Korea was initiated through the health examination for coal miners on 1957. Thereafter, the prevalence rate of pneumoconiosis among workers was found out as 2.3-4.9% on 1976.
Looking at health education aspect, 47% of workers responded as they were ignore about occupational diseases in knowledge, attitude and behavior study for them.
From this fact it is easily emphasized that heal th education activity should be urgently carried out in the industrial field. Therefore the author tried to plan and obtain the basic data on health education implementation in the industrial field in Korea through the sampling survey.
The interview survey was performed for health workers to whom health examination was carried out by the Institute of Industrial Health, Yonsei University on one hand, and on the other hand the mailing survey was done for industrial factories in the country where more than 1,000 workers were working.
The items of survey was consisted of size of the factory, time, methods, contents of health education and reasons for neglecting health education.
The result of the study are summarized as below.
1. The rate of education implementation was higher as size of industries were larger, the number of workers working in hazard environment was larger, the interest of manager was higher, the period of employment of health worker was longer.
2. The time of education was like below. In the industries employing below 50 workers, when workers go on duty and left one's work site. In the industries employing more than 50 workers and below 500 workers, when educator feels need and workers rest. In the industries employing more than 500 workers, when educator
feels need and workers visit health service center.
3. The lecture and printed material were used more frequently in whole industries as method of education.
4. The general health problem and emergency care were contained more frequently as the content of health education in whole industries.
5. The reasons for neglecting health education were inappropriate condition, insufficient manpower and teaching material in more than 50%.prohibitio
Large Sternocleidomastoid Haematoma after Minor Trauma in a Postradiation Neck
No full text Sternocleidomastoid (SCM) muscle haematoma after minor blunt injury is rare. Radiation therapy as a treatment for head and neck tumours e.g. nasopharyngeal cancer can result in complications, including fibrosis, scarring, and atrophy. We report a 51-year-old man suffering from massive haematoma of SCM muscle after minor blunt injury to a postradiation neck. Signs of haematoma were absent during his first visit to the emergency department. Emergency physicians need to be aware that bleeding from a postradiation neck, even after minor trauma, may be life threatening. </jats:p
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