• Title/Summary/Keyword: swelling volume

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Control of phosphoric acid induced volume change in clays using fly ash

  • Chavali, Rama Vara Prasad;Reddy, P. Hari Prasad
    • Geomechanics and Engineering
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    • v.15 no.6
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    • pp.1135-1141
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    • 2018
  • Volume changes of soils induced by inorganic acids cause severe foundation and superstructure failures in industrial buildings. This study aimed to assess the potential of fly ash to control volume changes in soils under acidic environment. Two soils such as black cotton soil predominant with montmorillonite and kaolin clay predominant with kaolinite were used for the present investigation. Both soils exhibited an increase in swelling subjected to phosphoric acid contamination. Ion exchange reactions and mineralogical transformations lead to an increase in swelling and a decrease in compressibility in black cotton soil, whereas phosphate adsorption and mineral dissolution lead to an increase in swelling and compressibility in case of kaolin clay. Different percentages of Class F fly ash obtained from Ramagundam national thermal power station were used for soil treatment. Fly ash treatment leads to significant reduction in swelling and compressibility, which is attributed to the formation of aluminum phosphate cements in the presence of phosphoric acid.

Genotypic and Environmental Effects on Flour Properties in Korean Winter Wheat

  • Hong, Byung-Hee;Park, Chul-Soo;Baik, Byung-Kee
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.47 no.1
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    • pp.1-12
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    • 2002
  • Flour characteristics of Korean winter wheat grown in Suwon in 1997 and 1998, and in Suwon and Deokso in 1998 were evaluated. Korean winter wheat cultivars were significantly influenced by years and locations in flour properties such as ash content, protein content, damaged starch content, starch swelling volume and power. Protein content was highly correlated with starch damage and alkaline water retention capacity. There were highly significant correlations between mixing time of mixograph and SDS sedimentation volume. Swelling properties of flour and starch were highly correlated with pasting properties of flour and starch, respectively. Compared to commercial flours for baking, Alchanmil, Gobunmil, Keumkangmil and Tapdongmil showed similar protein content, SOS sedimentation volume and mixograph mixing time. Eunpamil, Geurumil, Olgeurumil, Suwon 258, Suwon 261, Suwon 265, Suwon 275, Suwon 276, Suwon 277, Suwon 278 and Urimil had similar values to commercial noodle flours in SDS sedimentation volume. Alchanmil, Olgeurumil, Suwon 274, Suwon 275, Suwon 276 and Urimil showed higher swelling and pasting properties than the others. Chokwang, Olgeurumil, Suwon 277 and Urimil were similar to commercial cookie flours. Friabilin-absence lines showed higher protein content and starch damage than those of friabilin-presence lines. Absence lines of 1D$\times$2.2 + 1Dy12 subunit in high molecular weight glutenin subunits showed higher SDS sedimentation volume and mixing time of mixograph than those of presence lines.

Diffusion Coefficients of Polyimide/N-Methyl-2-Pyrrolidone Systems below Glass Transition Temperature (유리전이온도이하에서의 Polyimide/N-Methyl-2-Pyrrolidone계의 확산계수)

  • 박광승;김덕준
    • Polymer(Korea)
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    • v.24 no.2
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    • pp.194-200
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    • 2000
  • The diffusion coefficients in polyimide/N-methyl-2-pyrrolidone (NMP) systems were proposed using tile Vrentas-Duda's hole free volume theory. Several free volume parameters included in the diffusion coefficients were obtained from the fundamental physical properties of polyimide and NMP and group contribution theory, and the pre-exponential diffusion coefficient, D$_{0}$ was also determined from the dynamic swelling behavior of polyimide in NMP solution. The experimental swelling behavior of polyimide films in NMP was well described by the theoretical one using the proposed diffusion coefficient.t.

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A Comprehensive Swelling Model of Silicide Dispersion Fuel for Research Reactor (연구로용 우라늄실리사이드 분산형 핵연료의 팽윤모델)

  • Woan Hwang;Suk, Ho-Chun;Jae, Won-Mok
    • Nuclear Engineering and Technology
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    • v.24 no.1
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    • pp.40-51
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    • 1992
  • One of the important irradiation performance characteristics of the silicide dispersion fuel element in research reactors is the diameteral increase resulting from fuel swelling. This paper, will attempt to develop a physical model for the fuel swelling, DFSWELL, by analyzing the basic irradiation behaviours and some experimental evidences. From the experimental evidences, it was shown that the volume changes in irradiated U$_3$Si-Al were strongly dependent on temperature and fission rate. The quantitative-amount of swelling for silicide fuel is estimated by considering temperature, fission rate, solid fission product build-up and gas bubble behavior. The swelling for the silicide fuel is comprised of three major components : i ) a volume change due to the formation of an interfacial layer between the fuel particle and matrix. ii ) a volume change due to the accumulation of gas bubble nucleation iii ) a volume change due to the accumulation of solid fission products The DFSWELL model which takes into account the above three major physical components predicts well the absolute magnitude of silicide fuel swelling in accordance with the power histories in comparison with the experimental data.

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A CLASSIFICATION OF UNIQUELY DIFFERENT TYPES OF NUCLEAR FISSION GAS BEHAVIOR

  • HOFMAN GERARD L.;KIM YEON SOO
    • Nuclear Engineering and Technology
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    • v.37 no.4
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    • pp.299-308
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    • 2005
  • The behavior of fission gas in all major types of nuclear fuel has been reviewed with an emphasis on more recently discovered aspects. It is proposed that the behavior of fission gas can be classified in a number of characteristic types that occur at a high or low operating temperature, and/or at high or low fissile burnup. The crystal structure and microstructure of the various fuels are the determinant factors in the proposed classification scheme. Three types of behavior, characterized by anisotropic $\alpha$-U, high temperature metallic $\gamma$-U, and cubic ceramics, are well-known and have been extensively studied in the literature. Less widely known are two equally typical low temperature kinds: one associated with fission induced grain refinement and the other with fission induced amorphization. Grain refinement is seen in crystalline fuel irradiated to high burnup at low temperatures, whereas breakaway swelling is observed in amorphous fuel containing sufficient excess free-volume. Amorphous fuel, however, shows stable swelling if insufficient excess free-volume is available during irradiation.

Maxillary sinus haziness and facial swelling following suction drainage in the maxilla after orthognathic surgery

  • Lee, Jung-Soo;Kim, Moon-Key;Kang, Sang-Hoon
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.42
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    • pp.33.1-33.8
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    • 2020
  • Background: We investigated the efficacy of a maxillary Jackson-Pratt (J-P) suction drain for preventing maxillary sinus hematoma and facial swelling after maxillary Le Fort I osteotomy (LF1). Methods: We retrospectively evaluated 66 patients who underwent LF1 at a single institution. Of these, 41 had a J-P suction tube inserted in the mandible and maxilla (maxillary insertion), and 25 had a J-P drain inserted in the mandible only (no maxillary insertion). Facial CT was obtained before and 4 days after surgery. We compared mean midfacial swelling and maxillary sinus haziness by t test and examined correlations between bleeding amount and body mass index (BMI). Results: For the maxillary-insertion group, the ratio of total maxillary sinus volume to haziness (57.5 ± 24.2%) was significantly lower than in the group without maxillary drain insertion (65.5% ± 20.3; P = .043). This latter group, however, did not have a significantly greater midfacial soft tissue volume (7575 mm3) than the maxillary-insertion group (7250 mm3; P = .728). BMI did not correlate significantly with bleeding amount or facial swelling. Conclusions: Suction drainage in the maxilla reduced maxillary sinus haziness after orthognathic surgery but did not significantly reduce midfacial swelling.

Postoperative Brain Swelling after Resection of Olfactory Groove Meningiomas

  • Song, Sang-Woo;Park, Chul-Kee;Paek, Sun-Ha;Kim, Dong-Gyu;Jung, Hee-Won;Chung, Young-Seob
    • Journal of Korean Neurosurgical Society
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    • v.40 no.6
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    • pp.423-427
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    • 2006
  • Objective : Postoperative brain swelling after resection of olfactory groove meningiomas by bifrontal interhemispheric transbasal approach is a knotty subject. Pathogenesis and predictive factors were investigated to prevent the problem. Methods : Eighteen patients of olfactory groove meningiomas who had undergone surgery were enrolled and retrospectively analyzed using their clinical and radiological data. Bifrontal inter hemispheric transbasal approach was used in all patients. Magnetic resonance imaging and transfemoral cerebral angiography were available for investigation in 18 and 14 patients respectively. Postoperative clinical course, tumor volume, peritumoral edema, tumor supplying vessels, and venous drainage patterns were carefully investigated in relation to postoperative brain swelling. Results : Seven patients [39%] developed clinically overt brain swelling after surgery. Among them, 4 patients had to undergo decompression surgery. In three patients, attempted bone flap removal was done by way of prevention of increased intracranial pressure resulted from intractable brain swelling and two of them eventually developed brain swelling which could be recovered without sequellae. Abnormal frontal base venous channel observed in preoperative angiography was significant predictive factor for postoperative brain swelling [p=0.031]. However, tumor volume, peritumoral edema, and existence of pial tumor supplying vessels from anterior cerebral arteries were failed to show statistical significances. Conclusion : To prevent postoperative brain swelling in olfactory groove meningioma surgery, unilateral approach to preserve frontal base venous channels or temporal bone flap removal is recommended when it is indicated.

Effects of kinesiology tape after enucleation of mandibular dentigerous cysts

  • Kim, Min-Gyu;Kim, Moon-Young
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.46 no.2
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    • pp.108-115
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    • 2020
  • Objectives: Kinesiology tape (KT) creates a pulling force on the skin, thus improving blood and lymph flow by alleviating hemorrhage and congestion of lymphatic fluid. The authors hypothesized that the use of KT could be beneficial for the management of complications after head and neck surgery and designed this study to evaluate the effects of KT on swelling, pain, and trismus after enucleation of mandibular dentigerous cysts with third molar extraction. Materials and Methods: Forty patients who underwent enucleation of a dentigerous cyst with extraction of the mandibular third molar were selected. The patients were randomized into two groups (n=20 each): a KT group, where KT was applied after surgery in addition to basic postoperative care, and a control group, where patients received basic postoperative care without KT application. Swelling, pain, and trismus were evaluated before surgery (T0) and on postoperative days 1 (T1), 2 (T2), and 3 (T3). Cyst volume, gauze weight for assessing bleeding, and operation time were recorded. Results: There was a significant difference between the two groups in the change in swelling up to T1 and the change in swelling between T1 and T2. The maximum swelling in the KT group was significantly less than that in the No-KT group and maximum swelling appeared faster in the KT group than in the No-KT group. Both groups showed a mild pain response but there was no significant difference between the two groups. There was no significant difference on interincisal distance change between the two groups. There were no correlations between cyst volume, bleeding, operation time, and maximum swelling. Conclusion: KT can effectively manage facial swelling after oral and maxillofacial surgeries such as cyst enucleation and third molar extraction, thus improving postoperative patient satisfaction levels and quality of life.

The Analysis of HVDC Cable Oil Swelling Characteristics on the Silicone Rubber (HVDC 절연유 중에서 Silicone Rubber의 팽윤특성 분석)

  • Lee, T.H.;Kim, N.Y.;Kim, J.N.;Jeon, S.I.
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.623-624
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    • 2007
  • This work examines the effects of swelling MI type HVDC cable oil on the semiconductive silicone rubber and silicone rubber as used in accessories for application on outdoor termination (EBA) slip on sleeve. The behavior of volume resistivity is monitored as a function of the amount of cable oil diffused into the material. Resistivities of semiconductive silicone samples up to the typical insulator range (${\sim}10^{10}{\Omega}-cm$) are observed as a consequence of swelling due to the presence of the diffused oil. The measured volume resistivities of the oil-impregnated semiconductive silicone rubber are compared to desired value as function of stress relief cone.

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Modelling of effective irradiation swelling for inert matrix fuels

  • Zhang, Jing;Wang, Haoyu;Wei, Hongyang;Zhang, Jingyu;Tang, Changbing;Lu, Chuan;Huang, Chunlan;Ding, Shurong;Li, Yuanming
    • Nuclear Engineering and Technology
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    • v.53 no.8
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    • pp.2616-2628
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    • 2021
  • The results of effective irradiation swelling in a wide range of burnup levels are numerically obtained for an inert matrix fuel, which are verified with DART model. The fission gas swelling of fuel particles is calculated with a mechanistic model, which depends on the external hydrostatic pressure. Additionally, irradiation and thermal creep effects are included in the inert matrix. The effects of matrix creep strains, external hydrostatic pressure and temperature on the effective irradiation swelling are investigated. The research results indicate that (1) the above effects are coupled with each other; (2) the matrix creep effects at high temperatures should be involved; and (3) ranged from 0 to 300 MPa, a remarkable dependence of external hydrostatic pressure can be found. Furthermore, an explicit multi-variable mathematic model is established for the effective irradiation swelling, as a function of particle volume fraction, temperature, external hydrostatic pressure and fuel particle fission density, which can well reproduce the finite element results. The mathematic model for the current volume fraction of fuel particles can help establish other effective performance models.