• Title/Summary/Keyword: physical pretreatment

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Preparation of Silica-Filled SBR Compounds with Low Rolling Resistance by Wet Masterbatch

  • Yang, Jae-Kyoung;Park, Wonhyeong;Ryu, Changseok;Kim, Sun Jung;Kim, Doil;Seo, Gon
    • Elastomers and Composites
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    • v.55 no.1
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    • pp.26-39
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    • 2020
  • The physical properties of silica-filled SBR compounds (WSBR) prepared using silica-SBR wet masterbatches (WMB) were systematically investigated to understand the effect of the surface treatment of silica on the reinforcement performance of SBR. Treatment of silica with bis(triethoxysilylpropyl)tetrasulfide (TESPT) in the liquid phase, followed by mixing with an SBR solution and recovery by water stripping, easily produced silica-SBR WMB. However, insufficient surface treatment in terms of the amount and stability of the incorporated TESPT led to considerable silica loss and inevitable TESPT elution. Pretreatment of silica in the gas phase with TESPT and another organic material that enabled the formation of organic networks among the silica particles on the surface provided hydrophobated silica, which could be used to produce silica-SBR WMB, in high yields of above 99%. The amount and type of organic material incorporated into silica greatly influenced the cure characteristics, processability, and tensile and dynamic properties of the WSBR compounds. The TESPT and organic material stably incorporated into silica increased their viscosity, while the organic networks dispersed on the silica surface were highly beneficial for reducing their rolling resistance. Excessive dosing of TESTP induced low viscosity and a high modulus. The presence of connection bonds formed by the reaction of glycidyloxy groups with amine groups on the silica surface resulted in physical entanglement of the rubber chains with the bonds in the WSBR compounds, leading to low rolling resistance without sacrificing the mechanical properties. Mixing of the hydrophobated silica with a rubber solution in the liquid phase improved the silica dispersion of WSBR compounds, as confirmed by their low Payne effect, and preservation of the low modulus enhanced the degree of entanglement.

Ultrasound-guided PENG block versus intraarticular corticosteroid injection in hip osteoarthritis: a randomised controlled study

  • Selin Guven Kose;Halil Cihan Kose;Feyza Celikel;Serkan Tulgar;Omer Taylan Akkaya
    • The Korean Journal of Pain
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    • v.36 no.2
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    • pp.195-207
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    • 2023
  • Background: This study aimed to compare the effectiveness of the pericapsular nerve group (PENG) block and intra-articular injection (IAI) of steroid-bupivacaine in the treatment of hip osteoarthritis (OA). Methods: After randomization, patients received either a PENG block or IAI under ultrasound-guidance. Clinical evaluations were recorded at baseline, day 1, and weeks 1, 4, and 8 post-intervention. The numerical rating scale (NRS), Western Ontario and McMaster Universities Arthritis Index (WOMAC), Harris Hip Scale (HHS) scores, pain medication use determined by a quantitative analgesic questionnaire, and patient satisfaction were evaluated. Results: Sixty patients were included in this study. NRS scores improved significantly for both groups during the follow-up compared to pretreatment (P < 0.001), with better pain scores for the PENG group (P < 0.001) at day 1 with larger effect size (Cohen's d = 4.62), and IAI group at 4 (Cohen's d = 5.15) and 8 (Cohen's d = 4.33) weeks (P < 0.001). There was no significant difference in pain medication consumption (P = 0.499) and patient satisfaction (P = 0.138) between groups. Patients in the IAI group experienced significant improvement in HHS (Cohen's d = 2.16, P = 0.007) and WOMAC (Cohen's d = 1.02, P = 0.036) scores at 8 weeks compared to the PENG group. Conclusions: The ultrasound-guided PENG block provides effective pain relief which improves functionality and quality of life in hip OA patients up to 2 months. The PENG block can be considered an easy, safe, and useful alternative treatment modality for hip OA.

Biological Hydrogen Production from Mixed Waste of Food and Activated Sludge (음식물쓰레기와 폐활성슬러지의 혼합물로부터 혐기성 바이오 수소 생산)

  • Chung, Chong Min;Hong, Seok Won;Park, Chul Hee;Kim, Young O;Lee, Sang Hyup
    • Journal of Korean Society of Water and Wastewater
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    • v.22 no.5
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    • pp.571-580
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    • 2008
  • The influence of bacterial stress on anaerobic hydrogen-producing microorganisms was investigated in batch tests using serum bottles. Several physical and chemical stresses (i.e., heating, adding methane producing inhibitor and chemical acidification) were adapted as a pretreament of the seed sludge. In this experiment, the cultivation temperature were set at mesophilic ($35^{\circ}C$) and thermophilic conditions ($55^{\circ}C$) with adjusting pH at 5, 6, and 7 when using the mixture of food waste and activated sludge as a substrate. In conjunction with the pretreatment, hydrogen production was significantly enhanced as compared with that from untreated sludge. However, less biogas (hydrogen and methane) was produced without the pH control, resulted from the decrease of pH to below 4, mainly due to the formation of VFAs. Hydrogen and carbon dioxide gas were analyzed as main components of the biogas while methane not detected. With an application of chemical acidification, the highest hydrogen production value of 248 ml/l/day achieved at pH 7 and $35^{\circ}C$. In addition, more hydrogen gas produced when the ratio of butyric/acetic acid ratio increased. The optimum pH and temperature for hydrogen production were found to be 7 and $35^{\circ}C$, respectively.

Characteristics of Cadmium Biosorption and Desorption by Brown Marine Algae (갈색해조류에 의한 카드뮴의 흡착 및 탈착 특성)

  • 이학성
    • Journal of Environmental Science International
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    • v.8 no.2
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    • pp.249-254
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    • 1999
  • The biosorption and desorption of Cd were carried out using brown marine algae, known as the good biosorbent of heavy metals. The content of alginate bound to light metals could be changed by the physical and the chemical pretreatment of Sargassum fluitans biomass. The Cd uptake was independent of the alginate content. In case of protonated biomass, Cd uptake was the lowest because the alginic acid of biomass was dissolved to cadmium solution during the biosorption. The maximum Cd uptake of Sargassum biomass was ranged from 79 mg/g to 139 mg/g. In case of raw biomass, the higher the alginate content of biomass, the higher was the Cd uptake. 100% of Cd and light metals sorbed in the biomass were eluted at 0.1N HCI(pH 1.1). However, the elution efficiency in $CaCl_2$ and $Ca{(NO_3)}_2$solution was varied by the concentration, the solid to liquid ratio and the pH of calcium solution. The distribution coefficient between Cd and protons in the desorption solution at pH ranged from 1.6 to 2.9 was observed on the constant stoichometric coefficient(1.3).

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Biosynthesis of Xylobiose: A Strategic Way to Enrich the Value of Oil Palm Empty Fruit Bunch Fiber

  • Lakshmi, G. Suvarna;Rajeswari, B. Uma;Prakasham, R.S.
    • Journal of Microbiology and Biotechnology
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    • v.22 no.8
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    • pp.1084-1091
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    • 2012
  • Xylooligosaccharides are functional foods mainly produced during the hydrolysis of xylan by physical, chemical, or enzymatic methods. In this study, production of xylobiose was investigated using oil palm empty fruit bunch fiber (OPEFB) as a source material, by chemical and enzymatic methods. Xylanase-specific xylan hydrolysis followed by xylobiose production was observed. Among different xylanases, xylanase from FXY-1 released maximum xylobiose from pretreated OPEFB fiber, and this fungal strain was identified as Aspergillus terreus and subsequently deposited under the accession Number MTCC- 8661. The imperative role of lignin on xylooligosaccharides enzymatic synthesis was exemplified with the notice of xylobiose production only with delignified material. A maximum 262 mg of xylobiose was produced from 1.0 g of pretreated OPEFB fiber using FXY-1 xylanase (6,200 U/ml) at pH 6.0 and $45^{\circ}C$. At optimized environment, the yield of xylobiose was improved to 78.67 g/100 g (based on xylan in the pretreated OPEFB fiber).

Experimental Study for Consolidating Materials of the Excavated Wooden Coffin (출토 목관재 보존을 위한 강화처리제 연구)

  • Kim, Soo-Chul;Shin, Seong-Phil
    • Journal of Conservation Science
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    • v.20
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    • pp.81-88
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    • 2007
  • For the conservation of wooden coffin from King Muryeong's Tomb we examined weight change, shrinkage rate, color changes, and permeation expansion according to the permeation pretreatment chemicals by producing experimental samples with similar physical properties. The result shows Dammar 2 %(in xylene) as the most excellent treatment for protecting deformation by contraction and strengthening materials which are also maintaining its original colors of wood. Therefore, we could get strengthening conservation treatments of dried wooden coffin materials by using Dammar.

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Fundamental Study on Developing Lignocellulosic Fillers for Papermaking(I) (목질계 제지용 충전제 개발을 위한 기초연구(I))

  • Shin, Tae-Gi;Kim, Chul-Hwan;Chung, Ho-Kyung;Seo, Jung-Min;Lee, Young-Rok
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.40 no.2
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    • pp.8-15
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    • 2008
  • Wastewoods (logging residues) generated in Korea were used to make lignocellulosic fillers for papermaking. Lignocellulosic fillers could play great roles to increase retention efficiency and thus decrease turbidity of white water in papermaking process. In addition, lignocellulosic fillers could be used to improve physical properties of paper through their high affinity to cellulosic fibers, leading to the less use of chemical additives like retention aids. Wastewoods including Pinus densiflora and Quercus variabilis were chemically and mechanically treated for making fine particles passing through 100 mesh wire. The newly generated fillers showed larger particle size distribution than ground calcium carbonates but similar distribution to talc. In particular, pretreatment by hot water was more effective to generate smaller particle size than by alkali treatment. Lignocellulosic particles mixed with ground calcium carbonates under intense hybridizing condition greatly contributed to surface coverage of organic fillers in addition to filling to lumen and pits.

악관절 질환 환자에 대한 초기치료의 효과: 상담 및 투약

  • Kim, Yeong-Gyun;Kim, Hyeon-Tae;Kim, In-Su
    • The Journal of the Korean dental association
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    • v.38 no.6 s.373
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    • pp.549-557
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    • 2000
  • ㆍPurpose: This study was performed to investigate the initial conservative treatment for TMD patients using careful counselling and medication prospectively. ㆍMaterials and Methods: Careful counselling and medication were performed in 51 TMD patients and 27 patients had follow-up check 2 months or more. Diagnosis of TMD was based on medical history and, physical and radiographic examination. TMD included masticatory disorder, internal derangement, degenerative joint disease, inflammatory joint disorder. and problems resulting from extrinsic trauma. All patients had chief complaints of TMJ pain, mouth-opening limitation. joint noise, and/or referred pain. We counselled and explained to the patient about the pathogenesis, etiologic factors, diagnosis and treatment plan for abut 10 minutes. We prescribed nonsteroidal anti-inflammatorv analgesic(Somalgen) and amitriptyline 10mg per day for 2 weeks. We informed the patient of the attention sheet and taught self-exercise of jaw. The patient were assessed by answering the questionnaire of subjective evaluation of TMD & maxillofacial pain. Questionnaire of an activity limitation. Questionnaire of a jaw function, and Questionnaire for the evaluation of TMD. ㆍResults: In questionnaire for the evaluation of TMD, 88.5% of 26 patients answered that the treatment was efficacious. 71.4% of 21 patients answered no problem in everyday life. There were significant differences between pretreatment and final follow-up in the evaluation of the subjective pain in the following sections: opening widely, chewing, resting, morning, masticatory muscle, and temporal portion(SAS program, paired T-test, P = 0.05). ㆍConclusions: Considerate counselling and proper medication could be significantly effectve in the initial treatment of TMD.

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Biosorption of Cr, Cu and Al by Sargassum Biomass

  • Lee, Hak-Sung
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.2 no.2
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    • pp.126-131
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    • 1997
  • The biosorption and desorption of Cr, Cu and Al were carried out using brown marine algae Sargassum fluitans biomass, known as the good biosorbent of heavy metals. The content of alginate bound to light metals could be changed by physical and chemical pretreatment. The maximum uptake of Cr, Cu and Al was independent of the alginate content. The maximum uptaker of Al was two times(mole basis) than those of Cu and Cr. The aluminum-alginate complex was found in the sorption solution of raw and protonated biomass. Most of Cu, Al and light metals sorbed in the biomass were eluted at pH 1.1. However, only 5 to 10% of Cr sorbed was eluted at pH 1.1. The stoiceometric ion exchange between Cu and Ca ion was observed on Cu biosorption with Ca-loaded biomass. A part of Cr ion was bound to biomass as Cr(OH)2+ or Cr(OH)2+. Al was also bound to biomass as multi-valence ion and interfered with the desorbed Ca ion. The behavior of raw S. fluitans in ten consecutive sorption-desorption cycles has been investigated in a packed bed flow-through-column during a continuous removal of copper from a 35 mg/L aqueous solution at pH 5. The eluant used was a 1%(w/v) CaCl2/HC solution at pH 3.

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Effects of the Moxibustion Therapy on the Pain Decrease and Joint Recovery with Degenerative Knee Arthritis (뜸 치료가 퇴행성 슬관절 환자의 동통완화와 관절기능 회복에 미치는 영향)

  • Doh, Myung-Hea;Kim, Tae-Yeol
    • Journal of Society of Preventive Korean Medicine
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    • v.13 no.1
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    • pp.81-92
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    • 2009
  • Objective : This study was designed to the effect of moxibustion therapy on the pain decrease and joint recovery with degenerative knee arthritis Methods : The research was administered from January to March 2008. The study subjects are menopause female 20 person and over 50 years old with degenerative knee arthritis patients, The Research were conducted with 10 moxibustion group and to 10 hot pack group during 4 Weeks. Results : 1. There is no significant difference of LSS of pre-treatment between hot pack group and moxibustion group(p<0.05). 2. There is no significant difference of LSS of post-treatment between hot pack group and moxibustion group(p<0.05). 3. There is no significant difference of LSS between pretreatment and post-treatment in hot pack group and moxibustion group(p<0.05). 4. There is no significant difference of VAS of pre-treatment between hot pack group and moxibustion group(p<0.05). Conclusion : This study suggests that hot pack used usually in physical therapy can decrease pain but the there is no significantly different between these two methods.

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