• 해양환경안전학회지
• /
• 제15권2호
• /
• pp.135-142
• /
• 2009

본 연구는 고성능콘크리트의 강도조절과 수화열 저감을 위하여 쇄석 쇄사 생산시 발생되는 쇄석미분말을 사용하여 고성능콘리트의 강도, 유동성 내구성능 및 건조수축 특성을 검토한 것이다. 실험결과 쇄석미분말은 치환율 10% 증가시마다 무치환시의 압축강도를 약 $10{\sim}15%$씩 감소시키며, 변형계수와 물구속비를 감소시켜 고성능콘크리트의 유동성 향상에 효과적이다. 또한, 고성능콘크리트에서 쇄식미분말 10% 치환시 마다 단위시멘트량 감소에 따른 최고 단열온도상승량을 약 $4^{\circ}C$씩 감소시켰다. 반면 건조수축랑은 10% 치환시마다 약 5% 증가시키는 것으로 나타났다. 한편 고성능콘크리트의 내구성은 단위분체량과 유동성향상에 따른 조직의 치밀화로 쇄석미분말의 치환에 관계없이 상대동탄성계수 100%이상으로 우수하게 나타났다. 이와 같이 문제로서 쇄석미분말의 사용은 치환량에 따른 고성능콘크리트의 강도조절이 가능하며 수차 발열량을 저감시킬 수 있다.

• 한방재활의학과학회지
• /
• 제23권2호
• /
• pp.33-48
• /
• 2013

Objectives : Peripheral nerve injuries are commonly encountered clinical problems and often result in severe functional deficits. Sukjiyanggeun-Tang(shudiyangjin-tang), in oriental medicine, has been used to treat various musculoskeletal disorders. Methods : In the present study, the effects of aqueous extract of Sukjiyanggeun-Tang(shudiyangjin-tang) on functional recovery, severity of pain, and expressions of neurofilament, cycloxygenease-2(COX-2), inducible nitric oxide synthase(iNOS), and tumor necrosis factor-${\alpha}$(TNF-${\alpha}$) following sciatic crushed nerve injury in rats were investigated. For this study, walking tract analysis, plantar test, western blot analysis for COX-2 iNOS, and TNF-${\alpha}$, and Immunofluorescence test for neurofilament were performed. Results : In the present results, sciatic functional index(SFI) in walking tract analysis was significantly decreased following sciatic crushed nerve injury, and pain severity in plantar test was significantly increased. COX-2, iNOS and TNF-${\alpha}$ expressions were increased whereas neurofilament expression was decreased by sciatic crushed nerve injury, In contrast, treatment with Sukjiyanggeun-Tang(shudiyangjin-tang) improved SFI in walking tract analysis and suppressed the pain severity in sciatic crushed nerve injury. Sukjiyanggeun-Tang(shudiyangjin-tang) treatment also suppressed COX-2, iNOS, and TNF-${\alpha}$ expressions and enhanced the neurofilament expression in sciatic crushed nerve injury. Conclusions : In the present study, we have shown that Sukjiyanggeun-Tang(shudiyangjin-tang) is the effective therapeutic modality to ameliorate the symptoms of sciatic crushed nerve injury.

• 한방재활의학과학회지
• /
• 제23권2호
• /
• pp.17-31
• /
• 2013

Objectives : Peripheral nerve injuries are commonly encountered clinical problems and often result in serve functional deficit. Bee venom and scolopendra subspinipes have been traditionally used in oriental medicine to treat several inflammatory diseases and chronic pain conditions. Methods : In the present study, the effects of bee venom pharmacopuncture and scolopendra subspinipes pharmacopuncture on functional recovery, severity of pain, and expressions of neurofilament, cycloxygenease-2(COX-2), and tumor necrosis factor-${\alpha}$(TNF-${\alpha}$) following sciatic crushed nerve injury in rats were investigated. For this study, walking tract analysis, plantar test, western blot for COX-2 and TNF-${\alpha}$, and immunohistochemistry for neurofilament were performed. Results : In the present results, sciatic functional index(SFI) in walking tract analysis was significantly decreased following sciatic crushed nerve injury, and pain severity in plantar test was significantly increased. COX-2 and TNF-${\alpha}$ expressions were increased whereas neurofilament expression was decreased by sciatic crushed nerve injury. On the other hand, bee venom pharmacopuncture and scolopendra subspinipes pharmacopuncture improved SFI in walking tract analysis and suppressed the pain severity in sciatic crushed nerve injury. Bee venom pharmacopuncture and scolopendra subspinipes pharmacopuncture suppressed COX-2 and TNF-${\alpha}$ expression and enhanced the neurofilament expression in sciatic crushed nerve injury. Conclusions : In the present study, we have shown that treatment with bee venom or scolopendra subspinipes is the effective therapeutic modality to ameliorate the symptoms of sciatic crushed nerve injury. The efficacies of bee venom and scolopendra subspinipes were similar.

• 농업과학연구
• /
• 제47권3호
• /
• pp.485-496
• /
• 2020

Recent changes in the disaster environment have greatly increased the possibility of internal erosion in deteriorated reservoirs; thus, countermeasure methods are required to enhance the drainage performance of embankments. Sand filters have been mainly used to prevent internal erosion; however, due to the sand depletion and environmental problems, new alternative materials are required to replace the sand in the filter zone. In this study, crushed stone was used instead of sand as a material that could satisfy permeability, material supply, demanding conditions, and economic efficiency. Although crushed stone has excellent drainage performance, it has a clogging phenomenon due to its high permeability. Accordingly, the materials need to be separated with a geotextile wrapping method. Additionally, the 3D numerical analysis and a large model experiment were conducted to evaluate the seepage characteristics and in-site application of the crushed stone filter. As a result, the crushed stone filter showed an excellent dispersion effect by reducing the pore water pressure by about 9.5 times that of the sand filter. In addition, it was shown that the safety factor for piping increased significantly by reducing internal erosion. When comparing the economics and supply and demand conditions of the material, crushed stone was evaluated as an effective method to reduce the internal erosion of embankments at deteriorated reservoirs.

• 한국토양비료학회지
• /
• 제43권5호
• /
• pp.637-643
• /
• 2010

석회고토 및 패화석비료를 대체할 수 있는 토양개량제로 활용가치가 높은 굴껍질을 사과 '감홍' 재배 과수원에 시용하여 고두병 발생에 미치는 효과를 검토하였다. 석회고토와 굴껍질을 처리한구는 무처리구에 비해 표토와 심토의 토양 pH와 치환성 칼슘 함량이 증가된 반면, 치환성 나트륨 함량은 차이가 없었다. 사과의 고두병 발생비율은 무처리구가 10.4%로 가장 높았고 굴껍질 4 Mg$ha^{-1}$ 이상 처리할 경우 3.7% 이하로 유의적인 감소를 보였으며 석회고토 처리구는 8.9%로 무처리구와 비슷한 수준이었다. 굴껍질 시용량과 수확기 표토 및 심토의 pH와 치환성 칼슘 함량은 고두병 발병비율과 고도로 유의적인 부의상관을 보였다. 고두병 발병비율을 경감시킬 수 있는 굴껍질 시용량은 4 Mg $ha^{-1}$ 이지만 시험 후 토양의 치환성 칼슘 함량, pH 및 과실중량, 수량 등을 감안할 때 최적의 굴껍질 시용량은 2 Mg $ha^{-1}$로서 석회소요량과 같았다.

• Geomechanics and Engineering
• /
• 제16권3호
• /
• pp.273-284
• /
• 2018

A detailed understanding of the mechanical behaviors for crushed coal rocks after grouting is a key for construction in the broken zones of mining engineering. In this research, experiments of grouting into the crushed coal rock using independently developed test equipment for solving the problem of sampling of crushed coal rocks have been carried out. The application of uniaxial compression was used to approximately simulate the ground stress in real engineering. In combination with the analysis of crack evolution and failure modes for the grouted specimens, the influences of different crushed degrees of coal rock (CDCR) and solidified grout strength (SGS) on the mechanical behavior of grouted specimens under uniaxial compression were investigated. The research demonstrated that first, the UCS of grouted specimens decreased with the decrease in the CDCR at constant SGS (except for the SGS of 12.3 MPa). However, the UCS of grouted specimens for constant CDCR increased when the SGS increased; optimum solidification strengths for grouts between 19.3 and 23.0 MPa were obtained. The elastic moduli of the grouted specimens with different CDCR generally increased with increasing SGS, and the peak axial strain showed a slightly nonlinear decrease with increasing SGS. The supporting effect of the skeleton structure produced by the solidified grouts was increasingly obvious with increasing CDCR and SGS. The possible evolution of internal cracks for the grouted specimens was classified into three stages: (1) cracks initiating along the interfaces between the coal blocks and solidified grouts; (2) cracks initiating and propagating in coal blocks; and (3) cracks continually propagating successively in the interfaces, the coal blocks, and the solidified grouts near the coal blocks. Finally, after the propagation and coalescence of internal cracks through the entire specimens, there were two main failure modes for the failed grouted specimens. These modes included the inclined shear failure occurring in the more crushed coal rock and the splitting failure occurring in the less crushed coal rock. Both modes were different from the single failure mode along the fissure for the fractured coal rock after grouting solidification. However, compared to the brittle failure of intact coal rock, grouting into the different crushed degree coal rocks resulted in ductile deformation after the peak strength for the grouted specimens was attained.

• 한국농공학회논문집
• /
• 제57권4호
• /
• pp.31-38
• /
• 2015

This study aims to assess the effectiveness of limestone, zeolite, and crushed concrete as capping material to block the release of heavy metals (As, Cu, Cr, Ni, and Pb) and reduce the sediment oxygen demand. The efficiency of limestone, zeolite, and crushed concrete was evaluated in a reactor in which a 1-cm thick layer of capping materials was placed on the sediments collected from Inchon north harbor. Dissolved oxygen concentration and heavy metal concentration in seawater above the uncapped sediments and capping material were monitored for 17 days. The sediment oxygen demand was in the following increasing order: crushed concrete ($288.37mg/m^2{\cdot}d$) < zeolite ($428.96mg/m^2{\cdot}d$) < limestone ($904.53mg/m^2{\cdot}d$) < uncapped ($981.34mg/m^2{\cdot}d$). The capping materials could reduce the sediment oxygen demand by blocking the release of biochemical matters consuming dissolved oxygen in seawater. It was also shown that zeolite and crushed concrete could effectively block the release of Cu, Ni, and Pb but those were not effective for the interruption of As and Cr release from marine contaminated sediments.

• 대한한의학회지
• /
• 제30권3호
• /
• pp.28-38
• /
• 2009

Background : Peripheral nerve injuries are a commonly encountered clinical problem and often result in a chronic pain and severe functional deficits. Objective : The aim of this study was to evaluate the effects of Gentianae Macrophyllae Radix (G. M. Radix) on the pain control and the recovery of the locomotor function that results from the sciatic crushed nerve injury in rats. Method : Using rats, we crushed their sciatic nerve, and then orally administered the aqueous extract of G. M. Radix. The effects of G. M. Radix on the recovery locomotor function were investigated by walking track analysis. The effects of G. M. Radix on pain control were investigated by brain-derived neurotrophic factor (BDNF) expression in the sciatic nerve, and c-Fos expression in the paraventricular nucleus (PVN) of the hypothalamus and in the ventrolateral periaqueductal gray (vlPAG). Result : G. M. RADIX facilitates motor function from the locomotor deficit, and thereby increased BDNF expression and suppressed painful stimuli in the PVN and vlPAG after sciatic crushed nerve injury. Conclusion : It is suggested that G. M. Radix might aid recovery locomotor function and control pain after sciatic crushed nerve injury. Further studies on identifying specific the component in G.M. Radix associated with enhanced neural activity in the peripheral nerve injury may be helpful to develop therapeutic strategies for the treatment of peripheral nerve injury.

• 농업과학연구
• /
• 제37권1호
• /
• pp.97-104
• /
• 2010

In this study, a laboratory model test on utilization of recycled aggregates and crushed stone as vertical drains to use alternative material of sand in soft ground is performed. The vertical and horizontal coefficient of permeability of the recycled aggregates and crushed stone showed largely 1.2~4.0 times and 3.0~3.3 times greater than sand, respectively. Therefore, it showed enough to be an alternative material to the sand which had been being used as the vertical and horizontal drainage material before. The variations of pore water pressure with time showed constantly regardless of the load in all vertical drainage materials. When water level drops suddenly, the pore water pressure of the recycled aggregate and crushed aggregate is reduced to nearly zero. Therefore, it was applicable to the field because discharge capacity was similarity to that of sand. The settlement in crushed aggregates and recycled aggregate decreases gradually with the load increase. When water level drops suddenly, earth pressure in all drains materials was evaluated the equivalent drainage capacity similarity to sand because it show approaching the nearly zero.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2010년도 춘계 학술발표회
• /
• pp.1250-1255
• /
• 2010

In this study, in order to examine the hydraulic characteristics for a crushed stone mat. it was accomplished discharge capacity test and soil-water characteristic curve(SWCC) with the object of the research. From the test result, it produced propriety mixed ratio of the crushed stone which mixes the sand. at the time of crushed stone 100% where it does not mixes the sand it appeared that permeability was biggest. increase of shock and content of the sand showed decrease of air entry value.