Effects of Thoracic Mobility Exercise Program on Pain, Proprioception, and Static Balance Ability in Patients with non-Specific Chronic Low Back Pain

Donghwan Park(Donghwan Park),Kang-Seong Lee(Kang-Seong Lee) 물리치료재활과학회 2024 Physical therapy rehabilitation science Vol.13 No.1

Objective: The objective of this study was to investigate the effect of the thoracic mobility exercise program on pain, proprioception, and static balance ability in patients with non-specific chronic low back pain. Design: Randomized controlled trial design. Methods: Thirty patients with non-specific chronic low back pain participated in this study. The participants were randomized into the thoracic mobility exercise group (n=15) and the lumbar stabilization exercise group (n=15). Both groups received traditional physical therapy for 30 minutes per session. In addition, the thoracic mobility exercise group and the lumbar stabilization exercise group each exercise 3 times a week for 6 weeks. All participants were measured visual analog scale, proprioception test, and static balance ability before and after the intervention. Results: After 6 weeks of interventions, the thoracic mobility exercise group showed greater improvement in visual analog scale, proprioception test, and static balance ability than the LSE group (p<0.05). Further, the thoracic mobility exercise group had significant Enhancements in all measured variables compared to the baselinetest (p<0.05). However, the lumbar stabilization exercise group had significant improvement only visual analog scale, and static balance ability compared to the baselinetest (p<0.05). Conclusions: Our investigation demonstrates that the thoracic mobility exercise is an effective intervention method for improving pain, proprioception, and static balance ability in patients with non-specific chronic low back pain.

Effect of Acceleration Voltage on Phosphorus-Implanted Emitter of p-Type Crystalline Silicon Solar Cell

Park, Hyomin,Park, Sungeun,Lee, Seunghun,Kang, Yoonmook,Lee, Hae-Seok,Kim, Donghwan American Scientific Publishers 2016 Journal of Nanoscience and Nanotechnology Vol.16 No.10

<P>In this study, the effect of acceleration voltage on emitter properties was investigated. Phosphorus ion was implanted into a silicon substrate at acceleration voltages of 7, 13, and 20 KeV. As the acceleration voltage increased, the amorphous layer thickness increased from 14 to 33 nm. The projected ranges were around 10 to 13 nm, and little change was observed with the acceleration voltage. The as-implanted phosphorus concentrations as well as the junction depth were higher for higher acceleration voltages. As the phosphorus acceleration voltage increased, a larger and rougher area of contrast was observed at the amorphous/crystalline interface. After thermal treatment at 750 degrees C, strains were observed by high-resolution X-ray diffraction for all acceleration conditions. It was observed that a higher acceleration voltage resulted in a higher intensity of rocking curves with more fringes. Sheet resistances decreased rapidly after thermal treatment above 850 degrees C. The sheet resistance decreased with increasing annealing temperature, while at every temperature, the sample at 7 KeV acceleration voltage showed a higher sheet resistance than the samples at 13 and 20 KeV. The mobility increased for temperatures up to 850 degrees C but the carrier concentrations showed little change. Above 850 degrees C, the mobility did not show much change, but the carrier concentration increased. It is considered that the dopant activation was highly affected by the carrier concentration and not by the mobility.</P>

Effects of talus stabilization taping versus ankle kinesio taping in patients with chronic stroke : a randomized controlled trial

Donghwan Park,Kang-Seong Lee 한국운동재활학회 2019 JER Vol.15 No.6

Analysis of aluminum back surface field at different wafer specifications in crystalline silicon solar cells

Park, Sungeun,Park, Hyomin,Kang, Yoonmook,Lee, Hae-Seok,Kim, Donghwan Elsevier 2016 Current Applied Physics Vol.16 No.9

<P>The purpose of this work is to investigate a back surface field (BSF) at a number of wafer resistivities for industrial crystalline silicon solar cells. As indicated in this manuscript, doping a crucible-grown Czochralski (Cz)-Si ingot with Ga offers a sure way of eliminating light-induced degradation (LID) because LID is composed of B and O complex. However, the low segregation coefficient of Ga in Si causes a much wider resistivity variation in the Ga-doped Cz-Si ingot. This resistivity variation in a Cz-Si wafer at different locations varies the performance, as is already known. In the light of a B-doped wafer, we made wider resistivity in Si ingot; we investigated how resistivities affect the solar cell performance as a function of BSF quality. (C) 2016 Elsevier B.V. All rights reserved.</P>

Effect of surfactants on sol–gel transition of silk fibroin

Park, Ji Hun,Kim, Min Hee,Jeong, Lim,Cho, Donghwan,Kwon, Oh Hyeong,Park, Won Ho Springer-Verlag 2014 Journal of sol-gel science and technology Vol.71 No.2

Leukotriene B₄ receptors contribute to house dust mite-induced eosinophilic airway inflammation via T_H2 cytokine production

( Donghwan Park ),( Dong-wook Kwak ),( Jae-hong Kim ) 생화학분자생물학회 2021 BMB Reports Vol.54 No.3

Leukotriene B₄ (LTB₄) is a lipid mediator of inflammation that is generated from arachidonic acid via the 5-lipoxygenase pathway. Previous studies have reported that the receptors of LTB₄, BLT1, and BLT2 play mediatory roles in the allergic airway inflammation induced by ovalbumin (OVA). However, considering that house dust mites (HDMs) are the most prevalent allergen and well-known risk factor for asthmatic allergies, we are interested in elucidating the contributory roles of BLT1/2 in HDM-induced allergic airway inflammation. Our aim in this study was to investigate whether BLT1/2 play any roles in HDM-induced allergic airway inflammation. In this study, we observed that the levels of ligands for BLT1/2 [LTB₄ and 12(S)-HETE (12(S)-hydroxyeicosatetraenoic acid)] were significantly increased in bronchoalveolar lavage fluid (BALF) after HDM challenge. Blockade of BLT1 or BLT2 as well as of 5-lipoxygenase (5-LO) or 12-lipoxygenase (12-LO) markedly suppressed the production of T_H2 cytokines (IL-4, IL-5, and IL-13) and alleviated lung inflammation and mucus secretion in an HDM-induced eosinophilic airway-inflammation mouse model. Together, these results indicate that the 5-/12-LO-BLT1/2 cascade plays a role in HDM-induced airway inflammation by mediating the production of T_H2 cytokines. Our findings suggest that BLT1/2 may be a potential therapeutic target for patients with HDM-induced allergic asthma. [BMB Reports 2021; 54(3): 182-187]

Optimization of Controllable Factors in the Aluminum Silicon Eutectic Paste and Rear Silicon Nitride Mono-Passivation Layer of PERC Solar Cells

Park, Sungeun,Park, Hyomin,Kim, Dongseop,Yang, JungYup,Lee, Dongho,Kim, Young-Su,Kim, Hyun-Jong,Suh, Dongchul,Min, Byoung Koun,Kim, Kyung Nam,Park, Se Jin,Kim, Donghwan,Lee, Hae-Seok,Nam, Junggyu,Kang Springer-Verlag 2018 METALS AND MATERIALS International Vol.24 No.3

<P>Passivated emitter and rear contact (PERC) is a promising technology owing to high efficiency can be achieved with p-type wafer and their easily applicable to existing lines. In case of using p-type mono wafer, 0.5-1% efficiency increase is expected with PERC technologies compared to existing Al BSF solar cells, while for multi-wafer solar cells it is 0.5-0.8%. We addressed the optimization of PERC solar cells using the Al paste. The paste was prepared from the aluminum-silicon alloy with eutectic composition to avoid the formation of voids that degrade the open-circuit voltage. The glass frit of the paste was changed to improve adhesion. Scanning electron microscopy revealed voids and local back surface field between the aluminum electrode and silicon base. We confirmed the conditions on the SiNx passivation layer for achieving higher efficiency and better adhesion for long-term stability. The cell characteristics were compared across cells containing different pastes. PERC solar cells with the Al/Si eutectic paste exhibited the efficiency of 19.6%.</P>

Prediction of wall impingement in a direct injection spark ignition engine by analyzing spray images for high-pressure injection up to 50 MPa

Park, Junkyu,Kim, Taehoon,Kim, Donghwan,Park, Sungwook Elsevier 2018 Fuel processing technology Vol.179 No.-

<P><B>Abstract</B></P> <P>This study was performed to analyze the wall impingement and fuel film formation in a DISI engine with injection strategies using image-based analysis and CFD. The direct injection engine uses a high-pressure injection strategy to improve the homogeneity of the air-fuel mixture, so the spray behavior was analyzed by spray visualization for various injection pressures, and the wall impingement was predicted for various engine operating conditions based on the acquired images. The mass distribution of the injected fuel was calculated using the injection profiles and the spray image, and the amount of fuel that impinges on the piston and wall (i.e., the geometric boundaries of the cylinder) was calculated using data from the spray behavior for various engine operation conditions such as load and engine speed. The image-based analysis was limited to understanding the influence of the injection strategy on the droplet behavior after wall impingement of the fuel spray. Therefore, CFD using KIVA 3 V code was additionally conducted to analyze the effects of the injection strategies on wall film formation and droplet rebounding reflecting in-cylinder conditions. In the early- and late-injection conditions, the initial piston position is high, and most of the injected fuel impinges on the piston. As the injection pressure increases, the injection timing at which wall impingement occurs is advanced because of the rapid spray development. The results of the 3D analysis for the temperature and the intake flow in the engine cylinder showed that both the wall impingement and the fuel film were reduced as the injection pressure increased because the fuel evaporation increased due to improved atomization.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A prediction method of wall impingement in DISI engines is introduced. </LI> <LI> Effects of injection pressure and injection timing on spray wall impingement are analyzed using image-based method. </LI> <LI> 3D CFD are used to analyze effects of the engine conditions on formation of fuel film. </LI> <LI> Higher injection pressure conditions can reduce formation of fuel film due to superior vaporization characteristics. </LI> </UL> </P>

The Effect of Post-Fabrication Annealing on an Amorphous IGZO Visible-Light Photodetector

Park, Yongkook,Park, Hyung-Youl,Kang, Dong-Ho,Kim, Gwang-Sik,Lim, Donghwan,Yu, Hyun-Yong,Choi, Changhwan,Park, Jin-Hong American Scientific Publishers 2016 Journal of Nanoscience and Nanotechnology Vol.16 No.11

<P>We demonstrate the effect of the thermal annealing temperature (250 and 300 degrees C) on the performance (photosensitivity and temporal photoresponse) of an amorphous indium-gallium-zinc-oxide (alpha-IGZO) photodetector based on the TFT structure to visible radiation. Analysis of photosensitivity was performed to assess various sensing parameters, such as photoresponsivity (R-ph), threshold voltage (V-TH) shift, and subthreshold swing (SS). The photosensitivity was improved as the wavelength of light decreased and the annealing temperature increased. This was analyzed based on the activation energy for the ionization of an oxygen vacancy (V-o) and the concentration of Vo in relation to the thermal annealing condition. The temporal photoresponse of the alpha-IGZO device are also presented. The photoresponse times improved as the annealing temperature increased, which was due to the increase in the concentration of V-o functioning as a generation and recombination center with increasing annealing temperature.</P>

Hydrothermal carbonization of lipid extracted algae for solid fuel production

( Donghwan Sohn ),( Jongkeun Lee ),( Junhee Ryu ),( Youngho Park ),( Sungwan Cho ),( Ki Young Park ) 한국폐기물자원순환학회(구 한국폐기물학회) 2019 한국폐기물자원순환학회 심포지움 Vol.2019 No.1

As the microalgae are used as the third generation biomass, the area of cultivation is narrow and the growth is fast, so much research is being conducted for the production of biodiesel. During biodiesel production, lipid extracted algae (LEA) is generated from the algal biodiesel production industries. The LEA residue, after the extraction of lipid, is commonly considered as waste. The objective of this study is to produce alternative solid fuels from LEAs via HTC process as a method of bio-carbon recovery and waste disposal. In this study, feedstocks were used LEA form Chlorella vulgaris were extracted by Dimethyl Ether (DME), and untreated C. vulgaris. Experiments were performed using a lab-scale reactor with a volume of 1 L, into which 300mL of LEA or C.vulgaris feedstock, mixed with an equal amount of distilled was water loaded. The anaerobic condition was achieved by purging the reactor with nitrogen gas for sufficient time before the HTC experiments. The operating temperature ranged between 180 to 270℃ with the reaction being maintained for 30 min in the presence of subcritical water. The contents of the reactor were mixed vigorously using an agitator, rotating at 200 rpm. After the HTC treatment, the residual steam was discharged from the reactor. The reaction time, as a result, the carbon contents of LEA and microalgae increased from 47.16% to 58.45% and from 50.91% to 59.36%, respectively, as the treatment temperature increased until 210℃. Also, the calorific value was also increased, indicating the highest value of 6,594 kcal/kg and 6,800 kcal/kg at 210℃. LEA has low carbon content and calorific value compare with C.vulgaris, but it has enough high carbon content and calorific value for using solid fuel. In addition, the characteristics of solid fuel of LEA are enhanced by HTC, and the product may be sufficient to use solid fuel.