174 research outputs found
Association Analysis of Polymorphisms in Slc22a4 and Runx1 with Rheumatoid Arthritis Susceptibility and Disease Severity in a Korean Population
No full textLuffa cylindrica -inspired powerless micropump: long-term, high-flow operation and energy-generation application
No full textA biomimetic micropump inspired by Luffa cylindrica enhances passive fluid transport by integrating a hierarchical porous aerogel and flow resistors, enabling controlled and sustained operation for microfluidics and energy generation applications.Powerless micropumps are in increasing demand for applications requiring portability, simplicity, and long-term operation. However, several existing passive pumps have limitations such as sustained high flow rates and extended operational periods. Inspired by the unique structural characteristics of Luffa cylindrica , this study aims to develop a biomimetic micropump capable of long-term and high-flow operation. By examining the water transport mechanisms in a hierarchical porous structure, we designed and fabricated micropumps that replicate these mechanisms. A key aspect of this design is the integration of flow resistors, which enables precise control over the absorption rates and extend the pumping duration. The cone-shaped agarose aerogel (AAG) micropump operates for over 930 min with an average flow rate of 5.6 μl min −1 , demonstrating significant longevity. The agarose superabsorbent polymer aerogel (ASAG) micropump, while having a shorter operational duration of approximately 620 min, exhibited a significantly higher average pumping rate of 13.2 μl min −1 . This study highlights the potential of bio-inspired designs for advancing efficient and powerless pumping systems. The proposed micropump shows promise for applications in microfluidic devices and reverse electrodialysis systems, where continuous and sustainable fluid transport is essential.A biomimetic micropump inspired by Luffa cylindrica enhances passive fluid transport by integrating a hierarchical porous aerogel and flow resistors, enabling controlled and sustained operation for microfluidics and energy generation applications.Powerless micropumps are in increasing demand for applications requiring portability, simplicity, and long-term operation. However, several existing passive pumps have limitations such as sustained high flow rates and extended operational periods. Inspired by the unique structural characteristics of Luffa cylindrica , this study aims to develop a biomimetic micropump capable of long-term and high-flow operation. By examining the water transport mechanisms in a hierarchical porous structure, we designed and fabricated micropumps that replicate these mechanisms. A key aspect of this design is the integration of flow resistors, which enables precise control over the absorption rates and extend the pumping duration. The cone-shaped agarose aerogel (AAG) micropump operates for over 930 min with an average flow rate of 5.6 μl min −1 , demonstrating significant longevity. The agarose superabsorbent polymer aerogel (ASAG) micropump, while having a shorter operational duration of approximately 620 min, exhibited a significantly higher average pumping rate of 13.2 μl min −1 . This study highlights the potential of bio-inspired designs for advancing efficient and powerless pumping systems. The proposed micropump shows promise for applications in microfluidic devices and reverse electrodialysis systems, where continuous and sustainable fluid transport is essential.National Research Foundation of Korea https://doi.org/10.13039/50110000372
Ethnic differences in association of susceptibility to rheumatoid arthritis with single-nucleotide polymorphisms in PADI4, SLC22A4 and RUNX1 genes
No full text대한제국기 도시한옥 측량도면을 바탕으로
No full text학위논문 (석사)-- 서울대학교 대학원 : 건축학과, 2012. 2. 전봉희.이 연구는 가옥의 외곽선만 그려져 있는 대한제국기 도시한옥의 측량도면을 바탕으로 평면부터 구조, 입면에 이르기까지의 대한제국기 한성부 도시한옥의 건축적 내용을 복원하고자 하였다.
대한제국기의 근대적인 토지제도에 의하여 만들어진 도시한옥에 관한 도서 『토지가옥증명원본(土地家屋證明原本)』과 『토지가옥전당증명원본(土地家屋典當證明原本)』은 토지 및 가옥의 명확한 소유권 확립을 목표로 하는 것이었기 때문에 당시의 도시한옥에 대한 정확한 정보를 제공해 준다. 특히 근대적인 측량 기법과 제도에 의해 작성된 측량도면은 도시한옥에 대한 정확한 건축적 형태 정보를 제공하고 있어 대한제국기 도시한옥에 대한 복원적 연구를 진행할 수 있는 기본적 토대가 된다. 그러나 도서에 기록되어 있는 가옥의 정보는 토지 및 가옥의 평(坪), 칸(間) 등 규모 위주의 한정된 정보이기 때문에 이러한 정보만으로 도시한옥의 복원을 진행하는 것은 한계가 있다. 정보의 부족을 채우기 위해서는 당시의 가옥에 대한 2차 자료의 정보 및 목조 건축의 이론적인 내용이 뒷받침되어야 한다. 또한 각각의 정보들을 조합하여 하나의 건축물을 만들어 가는 과정에서 정보들 간의 간극을 메워야 하는 가정 설정이 필요하게 된다. 이러한 정보들과 가정에 의해 진행되는 복원적 연구는 대한제국기 한성부 도시한옥을 온전히 재현하지 못하더라도 잠정적 결론으로서 건축사적 의미를 가진다.
복원은 평면과 구조 및 입면으로 나누어 진행하였다. 평면 복원은 칸 나누기, 실 구성하기, 치수 조절하기의 세 단계로 구성하여 각 단계마다 세부적인 가정을 설정하였다. 이러한 가정을 복원 대상으로 선정한 가옥에 적용하여 평면 복원안을 도출하였다. 또한 구조 복원은 도시한옥을 입체적으로 재현하는 데 있어서 필수적인 상부 가구와 지붕형태를 중심으로 진행하였다. 상부 가구는 도시한옥의 규모와 평면과의 연계성을 고려하여 가구형식 등을 추정하였다. 지붕형태는 사진자료 등을 통하여 유형을 결정하고 그에 해당하는 서까래 배치를 복원하였다. 그리고 입면은 도시주거로서의 특징이 나타나는 가로입면과 소규모 주택으로서의 특징이 나타나는 마당입면을 복원하였다.
위와 같은 복원 과정을 거쳐 본 연구는 대한제국기 한성부 도시한옥의 평면과 구조 및 입면까지 복원하였으나 전반적인 복원 과정에서 세밀한 부분까지 다루지 못 했다는 한계가 있다. 그럼에도 불구하고 평면 복원은 세부적인 가정을 설정하여 도시한옥의 평면에 있어서 가장 중요한 요소인 칸과 실의 복원 가능성을 보여줌으로써 대한제국기 도시한옥 측량도면의 분석의 틀을 확장했다는 점에서 의미를 가진다. 또한 구조 및 입면 복원은 도시한옥을 입체적으로 복원하는 데 있어서 필수적인 상부가구와 지붕형태 및 주요 입면을 복원하여 이 후 대상 자료의 복원작업에 대한 토대를 마련했다는 의의를 가진다.Maste
THE POTENTIAL OF HYDROLYZED URINE AS A SOLVENT FOR BIOGAS UPGRADING
No full textDepartment of Urban and Environmental Engineering (Environmental Science and Engineering )Currently, global warming is accelerating and greenhouse gases are known to be the main cause. Therefore, various studies on the reduction of greenhouse gases have been carried out in order to solve global warming around the world. The purpose of this study is to separate carbon dioxide and methane from biogas in anaerobic digesters to reduce carbon dioxide, which accounts for a large proportion of greenhouse gases. As a criterion for selecting a suitable solvent, not only the reduction of carbon dioxide but also the recycling of collected carbon dioxide was also observed. This study on the solvent which plays a dominant role in the physical interaction rather than the chemical interaction with the carbon dioxide enables us to improve the reuse efficiency of the solvent through the increase and decrease of the pressure. In order to find a suitable solvent for the purpose of the experiment, the solvent was divided into five categories. Water was used as a basic comparison of the experiments and pure solvents were used to increase the dissolved amount of carbon dioxide. We also used an aqueous solution of artificial seawater with salt added to the water to determine how salt influences the degassing of the anaerobic digestion gas (AD gas). The aqueous solution was used to confirm the synergy effect between water and solvent. Finally, the experiment was carried out by mixing acetone-based solutions with various advantages in pure solvent form. To maximize the merits of each solvent, we have combined three tertiary systems: water with the advantage of increasing the rate of carbon dioxide degassing, salt that can lead to a salting out effect, and acetone, which can increase the solubility of carbon dioxide. Compared with other experimental conditions in the tertiary system, it was possible to capture a high rate of carbon dioxide in the degassed AD gas with increasing solubility of carbon dioxide. It is concluded that the tertiary system is the best condition for the experimental purpose in the case of containing a small amount of water.clos
Analysis of a geometric path tracking method for a nonholonomic mobile robots based on vector pursuit
No full textThe path tracking is important method in the autonomous navigation. The path tracking controller should be robust with the large tracking error, and the geometric path tracking methods already have an ability to overcome that problem. In this paper, we deal with the vector pursuit which is the one of the geometric path tracking methods. We proposed the new path tracking control system which can determines the look-ahead distance with the given constraints, the reference velocity and the limit on the angular velocity. The simulation and the experiment result show that the mobile robot satisfies the constraints while it follows the path. �� 2009 SICE
The study of data transfer method non-matching meshes interface using common-refinement method for fluid-structure interface
No full text본 연구는 유체-고체 연성 해석이 활발히 진행되고 있는 고체로켓의 3차원 연소실 상경계면 형상에 대해 정보 전달 기법 중 하나인 공통세분 기법의 적용을 목적으로 수행되었다. 본 기법은 불일치하는 경계면간 정보 전달에도 보존성과 정확도를 동시에 만족시킬 수 있다는 장점을 갖는다. 기법 구현은 상경계면에 공통표면을 구성하고 특정 오차를 최소화 시키는 최소화 내삽법을 적용하는 과정으로 수행되었다. 이를 바탕으로 다양한 다차원 상경계면 형상에서 연속 및 불연속 함수를 이용한 정보 전달 실험을 수행하였고, 다른 기법들과 해석 결과를 비교하였다.During multi-physics or multi-phase simulations accompanying fluid- structure- thermal interaction, data transfer problems always arise along non- matching interfaces caused by different computational meshes for each physical domain. Common- refinement scheme, among many available methods, is attractive since it is known to yield conservative and accurate data transfer for non- matching interface cases. This is particularly important in simulating compressible unsteady fluid- structure- thermal interaction inside solid propellant rockets, where grid size along solid- fluid interfaces is substantially different. From this perspective, we examine performances of common- refinement- based data transfer scheme between structured quadrilateral (structure part) and unstructured triangular (fluid part) meshes by comparing computed results with other data transfer methodsOAIID:oai:osos.snu.ac.kr:snu2014-01/102/0000004648/1SEQ:1PERF_CD:SNU2014-01EVAL_ITEM_CD:102USER_ID:0000004648ADJUST_YN:YEMP_ID:A001138DEPT_CD:446CITE_RATE:0FILENAME:유체-구조_연성_해석을_위한_common-refinement_기반_불일치_격자_경계면에서의_정보_전달_기법_연구.pdfDEPT_NM:기계항공공학부SCOPUS_YN:NCONFIRM:
Optimal design of the task-oriented wearable robot for the upper extremity
No full textThis study presents several measures aimed at mathematically quantifying characteristics associated with human performance and wearable robot platform; there will be trials for improving the kinematic performance of the proposed wearable robot system through the optimization methodology. Within constrained conditions, optimal link lengths will be defined for its objectives and purposes. In particular, parameters from these studies and experiments, is one way of improving its performance of function-orient human robot corporative system; they are used for quantifying the feeling of putting on platform and flexibility, too. �� 2009 SICE
Enhancing Fuel Cell Durability with Heteroenergetic TaOx -Carbon Support
No full textAttaining the high durability of supported metal catalysts in heterogeneous catalysis remains a significant challenge. Here, we introduce a mixed tantalum oxide-carbon support for an oxygen reduction reaction catalyst in alkaline fuel cells, aiming to address the degradation arising from suboptimal metal-support interactions. The composite support, conceptualized as a heteroenergetic support, comprises two distinct components exhibiting substantially disparate affinities for metal nanoparticles (NPs). This unique configuration ensures the effective stabilization of the metal NPs on the support. The Au-doped Pd NPs on the mixed tantalum oxide-carbon support exhibit fully sustained mass activity even after a 10000-cycle accelerated durability test. This exceptional durability is ascribed to the effective suppression of the particle agglomerations, as elucidated through transmission electron microscopy and X-ray photoelectron spectroscopy. Our study highlights the efficacy of a heteroenergetic support as a compelling approach for achieving ultradurability in catalytic operations and indicates the broad applicability of this strategy for diverse reactions.
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