RELATIVE HEAT EXCHANGE RATE FOR DESIGN OF ENERGY PILE

Sunhong Min,Chulho Lee,Hyungseon Koh,Jaihyun Yoo,Kyoungsik Jung,Hangseok Choi 한국신재생에너지학회 2011 AFORE Vol.2011 No.-

에너지 파일의 열교환 효율 및 성능, 열응력에 의한 역학적 거동 평가

민선홍(Sunhong Min),이철호(Chulho Lee),박문서(Moonseo Park),고형선(Hyungseon Koh),최항석(Hangseok Choi) 한국지열·수열에너지학회 2010 한국지열에너지학회논문집 Vol.6 No.2

The ground source heat pump system is increasingly being considered as an alternative to traditional heating and cooling systems to reduce the emission of ground house gases. In this paper, A series of numerical analysis for energy piles has been performed focusing on heat transfer efficiency, performance and thermal stress. Results of numerical analyses for the W-shape type shows more efficient heat exchange transfer than the coil type. From results of the thermo-mechanical analysis, it is shown that the concentration of thermal stress occurs around the circulating pipe and the interfaces between different materials. The largest deformation caused by thermal stress is observed in the energy pile.

Performance-based comparison of energy pile of various heat exchange pipe arrangement by in-situ thermal response test

민선홍(Min, Sunhong),고형선(Koh, Hyungseon),유재현(Yoo, Jaihyun),정경식(Jung, Kyoungsik),이영진(Lee, Youngjin),최항석(Choi, Hangseok) 한국신재생에너지학회 2011 한국신재생에너지학회 학술대회논문집 Vol.2011 No.05

In this study, a test bed was constructed in order to evaluate thermal efficiency of the energy pile which carries out combined roles of a structural foundation and of a heat exchanger. The energy pile in this study is designed as a large-diameter drilled shaft equipped with the heat exchange pipes which configures a W-shape and an S-shape. The drilled shaft reached to the depth of 60 m whilst the heat exchange pipes were installed to about 30 m deep from the ground surface. The W-shaped and S-shaped heat exchange pipes were installed in the opposite sections of the same drilled shaft. In-situ thermal response tests were performed for both the shapes of heat exchange pipes. To avoid underestimating the thermal performance due to hydration heat of concrete inside the drilled shaft, the in-situ thermal response tests for the energy pile were performed after four weeks since the installation of the energy pile.

에너지 파일의 열전달 효율과 열응력에 의한 역학적 거동 분석

민선홍(Min Sunhong),이철호(Lee Chulho),박문서(Park Moonseo),최항석(Choi Hangseok) 대한토목학회 2010 대한토목학회 학술대회 Vol.2010 No.10

Epigenetic Changes in Neurodegenerative Diseases

이성배,Min Jee Kwon,Sunhong Kim,Myeong Hoon Han 한국분자세포생물학회 2016 Molecules and cells Vol.39 No.11

Afflicted neurons in various neurodegenerative diseases generally display diverse and complex pathological fea-tures before catastrophic occurrence of massive neuronal loss at the late stages of the diseases. This complex nature of neuronal pathophysiology inevitably implicates systemwide changes in basic cellular activities such as transcriptional controls and signal cascades, and so on, as a cause. Recently, as one of these systemwide cellular changes associated with neurodegenerative diseases, epigenetic changes caused by protein toxicity have begun to be highlighted. Notably, recent advances in related techniques including next-generation sequencing (NGS) and mass spectrometry enable us to monitor changes in the post-translational modifications (PTMs) of histone proteins and to link these changes in histone PTMs to the specific transcriptional changes. Indeed, epigenetic alterations and consequent changes in neuronal transcriptome are now begun to be extensively studied in neurodegener-ative diseases including Alzheimer’s disease (AD). In this review, we will discuss details of our current understand-ings on epigenetic changes associated with two repre-sentative neurodegenerative diseases [AD and polygluta-mine (polyQ) diseases] and further discuss possible future development of pharmaceutical treatment of the diseases through modulating these epigenetic changes.

Allele-Specific Suppressors of <i>lin-1(R175Opal)</i> Identify Functions of MOC-3 and DPH-3 in tRNA Modification Complexes in <i>Caenorhabditis elegans</i>

Kim, Sunhong,Johnson, Wade,Chen, Changchun,Sewell, Aileen K.,Byströ,m, Anders S.,Han, Min The Genetics Society of America 2010 Genetics Vol.185 No.4

Supramolecular networking of macrocycles based on exo-coordination: from discrete to continuous frameworks.

Park, Sunhong,Lee, So Young,Park, Ki-Min,Lee, Shim Sung American Chemical Society 2012 Accounts of chemical research Vol.45 No.3

<P>Macrocyclic ligands typically show high selectivity for specific metal ions and small molecules, and these features make such molecules attractive candidates for nanoscale chemical sensing applications. Crown ethers are macrocyclic structures with polyether linkages where the oxygen donors are often separated by an ethylene unit (-O-CH(2)-CH(2)-O-). Because the oxygen lone pairs in crown-type macrocycles are directed inward, the preorganized macrocyclic cavity tends to form complexes where metals coordinate inside the cavity (endo-coordination). However, sulfur-containing macrocycles often demonstrate metal coordination outside of the cavity (exo-coordination). This coordination behavior results from the different torsion arrangements adopted by the X-CH(2)-CH(2)-X atom sequence (X = O, gauche; X = S, anti) in these molecules. Exo-coordination is synthetically attractive because it would provide a means of connecting macrocyclic building blocks in diverse arrangements. In fact, exo-coordination could allow the construction of more elaborate network assemblies than are possible using conventional endocyclic coordination (which gives metal-in-cavity products). Exo-coordination can also serve as a tool for crystal engineering through the use of diverse controlling factors. Although challenges remain in the development of exo-coordination-based synthetic approaches and, in particular, for the architectural control of supramolecular coordination platforms, we have established several strategies for the rational synthesis of new metallosupramolecules. In this Account, we describe our recent studies of the assembly of metallosupramolecules and coordination polymers based on sulfur-containing macrocycles that employ simple and versatile exo-coordination procedures. Initially, we focus on the unusual topological products such as sandwich (1:2, metal-to-ligand), club sandwich (2:3), and cyclic oligomeric complexes as discrete network systems. The primary structures we achieve in these networked macrocycles are one to three dimensional coordination polymers based on homo- and heteronuclear metal systems. Using crystal engineering methods, we have also investigated variation in the donors, interdonor distances, ligand isomer structures, and the effect of counter anions on the chemical and physical properties of the products. Understanding the relationship between structure and function in these exo-coordination products is an important step in the design of these new supramolecules for practical applications. We investigated the photophysical properties of the exocyclic complexes and a chromogenic macrocycle, which exhibited cation-selective and anion-controlled color change depending on an exo- or endo- ligand binding mode. Overall, we suggest that the exocyclic coordination behavior provides a versatile strategy for the preparation of new molecular networks and materials.</P>

Epigenetic Changes in Neurodegenerative Diseases

Kwon, Min Jee,Kim, Sunhong,Han, Myeong Hoon,Lee, Sung Bae Korean Society for Molecular and Cellular Biology 2016 Molecules and cells Vol.39 No.11

Afflicted neurons in various neurodegenerative diseases generally display diverse and complex pathological features before catastrophic occurrence of massive neuronal loss at the late stages of the diseases. This complex nature of neuronal pathophysiology inevitably implicates systemwide changes in basic cellular activities such as transcriptional controls and signal cascades, and so on, as a cause. Recently, as one of these systemwide cellular changes associated with neurodegenerative diseases, epigenetic changes caused by protein toxicity have begun to be highlighted. Notably, recent advances in related techniques including next-generation sequencing (NGS) and mass spectrometry enable us to monitor changes in the post-translational modifications (PTMs) of histone proteins and to link these changes in histone PTMs to the specific transcriptional changes. Indeed, epigenetic alterations and consequent changes in neuronal transcriptome are now begun to be extensively studied in neurodegenerative diseases including Alzheimer's disease (AD). In this review, we will discuss details of our current understandings on epigenetic changes associated with two representative neurodegenerative diseases [AD and polyglutamine (polyQ) diseases] and further discuss possible future development of pharmaceutical treatment of the diseases through modulating these epigenetic changes.

PERFORMANCE ANALYSIS OF GROUND-SOURCE HEAT PUMP SYSTEM WITH ENERGY PILES USING SIMULATION APPROACH

Byonghu SOHN,Sunhong MIN,Jongmuk WON,Hangseok CHOI 한국신재생에너지학회 2011 AFORE Vol.2011 No.-

등가열교환율을 적용한 현장타설 에너지파일 설계법

민선홍,박상우,정경식,최항석,Min, Sunhong,Park, Sangwoo,Jung, Kyoungsik,Choi, Hangseok 대한토목학회 2013 대한토목학회논문집 Vol.33 No.3

본 연구에서는 현장타설 에너지파일의 열교환 파이프 배치 형태별 열교환율을 전산유체해석 프로그램(FLUENT)을 이용하여 평가하고, 이를 이용하여 에너지파일의 설계법을 제시하였다. 등가열교환율을 산정하기 위해 동일한 현장타설말뚝 제원에 대해 열교환파이프 배치 형태를 W-형(직렬), 복합 U-형(병렬 4쌍), 나선형의 3가지로 고려하였다. 건물측 부하조건은 여름철 냉방운용를 모사하기 위해 순환수의 에너지파일 유입온도, 즉 히트펌프 유출온도(Leaving water temperature, LWT)를 $35^{\circ}C$로 일정하게 유지하여 에너지파일 유출온도, 즉 히트펌프 유입온도(Entering water temperature, EWT) 변화를 관찰하였다. 지반에 최대 가상부하를 적용한 경우(100시간 연속 냉방부하 조건)에는 3가지 열교환기 형태가 유사한 열교환율을 보인 반면, 실제 히트펌프 가동에 의한 건물 냉방운용을 모사하기 위해 간헐적으로 일일 8시간 운용-16시간 정지를 7일간 반복 해석한 경우에는 W-형(직렬연결)과 복합 U-형(병렬 4쌍) 열교환기는 유사한 열교환율을 보이나, 나선형 열교환기는 파이프 루프 상호 간 열간섭으로 인해 복합 U-형 열교환기에 비해 약 86%의 열교환율을 갖는 것으로 평가되었다. 전산유체해석에 의해 계산된 열교환파이프 배치 형태별 에너지파일의 등가열교환율을 에너지파일 설계프로그램(PILESIM2)에 적용하여 다양한 형상의 현장타설 에너지파일에 대한 설계법과 대표적인 설계변수에 대한 설계도표를 제시하였다. In this paper, a relative heat exchange rate is numerically compared for cast-in-place concrete energy piles with different heat exchange pipe configurations, and a new design method for energy piles is proposed. An equivalent heat exchange rate was estimated for the W-type (one series loop), multiple U-type (four parallel loops), and coil-type heat exchanger installed in the same large-diameter drilled shaft. In order to simulate a cooling operation in summer by a CFD analysis, the LWT (leaving water temperature) into a energy pile was fixed at $35^{\circ}C$ and then the EWT (entering water temperature) into a heat pump was monitored. In case of continuously applying the artificial maximum cooling load for 100 hours, all of the three types of heat exchangers show the marginally similar heat exchange rate. However, in case of intermittently applying the cooling load with a cycle of 8 hours operation-16 hours off for 7 consecutive days, the coil type heat exchanger exhibits a heat exchange rate only 86 % of the multiple U-type due to measurable thermal interference between pipe loops in the energy pile. On the other hand, the W-type possesses the similar heat exchange rate to the multiple U-type. The equivalent heat exchange rates for each configuration of heat exchangers obtained from the CFD analysis were adopted for implementing the commercial design program (PILESIM2). Finally, a design method for cast-in-place concrete energy piles is proposed along with a design chart in consideration of typical design factors.