• Title/Summary/Keyword: volume expansion

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Analysis of the Chest Expansion and Pulmonary Function in the 20s men Obesity according to Position Change (20대 남성 비만인의 자세에 따른 가슴우리 확장과 폐기능 특성분석)

  • Kim, Hyeun-Ae;Seo, Kyo-Chul;Yim, Sang-Yoan;Kim, Hee-Tak;Kim, Kyoung
    • Journal of the Korean Society of Physical Medicine
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    • v.6 no.3
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    • pp.247-256
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    • 2011
  • Purpose : The purpose of this study were to determine whether changes of position might effect the chest expansion and pulmonary function of the 20s men obesity. Methods : Thirty subjects with obesity(M:30, % fat>25.0) and thirty normal subjects(M:30, % fat<24.9) were participated in experiment. Subjects were assessed according to position changes(supine position, $45^{\circ}$ lean sitting position, $90^{\circ}$ sitting position) using chest length(chest length for resting, chest expansion) and pulmonary function (Tidal volume, Inspiratory capacity, Vital capacity, Inspiratory reserve volume, Expiratory reserve volume) by the CardioTouch 3000S(BIONET, USA). Repeated measure ANOVA was used to compare each region data of chest length and pulmonary function according to changes of position with obesity and normal subjects. Results : These findings suggest that the obesity can be appear to low chest expansion and pulmonary function than normal subjects on position method. In comparison of three experimental position, supine position was more low. Conclusion : This study showed position of the obesity appear low chest expansion and function of pulmonary volume than normal subjects, and thus it indicates that the pulmonary function of the obesity will be suggest objective respiratory data through the exercise program.

Evaluation on Cavity Expansion under Pavement based on Groundwater Injection test (지하수 주입실험을 통한 도로노면 하부의 공동 확장 평가)

  • Park, Jeong-Jun;You, Seung-Kyong;Hong, Gigwon
    • Journal of the Korean Geosynthetics Society
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    • v.18 no.3
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    • pp.79-88
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    • 2019
  • This study described a results of groundwater injection test in cavity, in order to evaluate characteristics of cavity expansion under pavement. That is, groundwater amount proportional to the cavity volume was injected into the generated cavity step by step, and then the cavity with the changed size was monitored as the injected groundwater was drained. The test result showed that the cavity volume by groundwater injection increased, and then it converged or decreased. This means that some of the relaxation soil around the cavity collapsed, and the fine-grained soils in some soils filled the void in the surrounding soils when the cavity is expanded by groundwater injection. The volume change and expansion characteristics of the cavity according to the groundwater injection step were analyzed. The result showed that the cavity extended laterally. Therefore, it was found that the cavity expansion is caused by the repetition of the relaxation soil collapse due to the groundwater flow and the loss of the collapsed soil below the cavity.

Prediction of Thermal Expansion Coefficients for Fiber-Reinforced Composites by Direct Numerical Simulation (직접 수치 모사법을 이용한 섬유 강화 복합재료의 열팽창계수 예측)

  • Nam, Youn-Sic;Oh, Min-Hwan;Kim, Kwang-Sik;Cho, Jin-Yeon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.35 no.9
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    • pp.771-777
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    • 2007
  • In this paper, thermal expansion coefficients of fiber-reinforced composite materials are predicted by direct numerical simulation. From comparing the predicted results with experimental results, it is confirmed that direct numerical simulation gives similar results to the previously proposed methods while minimizing artificial assumptions. Additionally trend of variation in thermal expansion coefficients is investigated according to the fiber volume fraction.

Expansion Characteristics of the Hydrated Sodium Silicate (수화된 규산소다의 팽창 특성)

  • Kong, Yang-Pyo;Cho, Ho-Yeon;Suhr, Dong-Soo
    • Journal of the Korean Ceramic Society
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    • v.45 no.1
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    • pp.54-59
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    • 2008
  • Hydrated sodium silicate with 25 wt% water contents was synthesized by hydrothermal reaction using anhydrous sodium silicate. The hydrated sodium silicate was expanded at $370^{\circ}C$ for 30 min. and then pulverized, classified (- 200 mesh) and press-formed. The samples were heat treated at $400{\sim}900^{\circ}C$ for 30 min. in order to study the expansion characteristics depending on heat treatment temperature. A porous body with closed pore was formed above $600^{\circ}C$. The volume expansion ratio and the pore size were increased and the specific gravity was decreased with increasing heat treatment temperature. However, the volume expansion ratio was decreased and the specific gravity was increased above $850^{\circ}C$ due to the softening of the sodium silicate.

Two-Stage Latissimus Dorsi Flap with Implant for Unilateral Breast Reconstruction: Getting the Size Right

  • Feng, Jiajun;Pardoe, Cleone I;Mota, Ashley Manuel;Chui, Christopher Hoe Kong;Tan, Bien-Keem
    • Archives of Plastic Surgery
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    • v.43 no.2
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    • pp.197-203
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    • 2016
  • Background The aim of unilateral breast reconstruction after mastectomy is to craft a natural-looking breast with symmetry. The latissimus dorsi (LD) flap with implant is an established technique for this purpose. However, it is challenging to obtain adequate volume and satisfactory aesthetic results using a one-stage operation when considering factors such as muscle atrophy, wound dehiscence and excessive scarring. The two-stage reconstruction addresses these difficulties by using a tissue expander to gradually enlarge the skin pocket which eventually holds an appropriately sized implant. Methods We analyzed nine patients who underwent unilateral two-stage LD reconstruction. In the first stage, an expander was placed along with the LD flap to reconstruct the mastectomy defect, followed by gradual tissue expansion to achieve overexpansion of the skin pocket. The final implant volume was determined by measuring the residual expander volume after aspirating the excess saline. Finally, the expander was replaced with the chosen implant. Results The average volume of tissue expansion was 460 mL. The resultant expansion allowed an implant ranging in volume from 255 to 420 mL to be placed alongside the LD muscle. Seven patients scored less than six on the relative breast retraction assessment formula for breast symmetry, indicating excellent breast symmetry. The remaining two patients scored between six and eight, indicating good symmetry. Conclusions This approach allows the size of the eventual implant to be estimated after the skin pocket has healed completely and the LD muscle has undergone natural atrophy. Optimal reconstruction results were achieved using this approach.

Fabrication of Polymeric Optical Fiber Array (정밀 고분자 광섬유 어레이 제작 연구)

  • Cho, Sang-Uk;Jeong, Myung-Yung;Kim, Chang-Seok;Ahn, Seung-Ho
    • Journal of the Korean Society for Precision Engineering
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    • v.24 no.5
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    • pp.82-88
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    • 2007
  • This work is to fabricate a precise optical fiber array using polymer composite for optical interconnection. Optical fiber array has to satisfy low optical loss requirement less than 0.4 dB according to temperature change. For this purpose, design criteria for an optical fiber array was derived. The coefficient of thermal expansion of silica particulate epoxy composites was affected by volume fraction of silica particles. And also, elastic modulus of silica particulate epoxy composites was affected by volume fraction of silica particles. To obtain the coefficients of thermal expansion below $10{\times}10E-6/^{\circ}C$ and elastic modulus more than 20 GPa , we chose the volume fraction more than 76%. Using silica particulate epoxy composites with the volume fraction 76%, 8-channel optical fiber array with dimensional tolerances below $1\;{\mu}m$ was manufactured by transfer molding technique using dies with the uniquely-designed core pin and precisely-machined zirconia ceramic V block. These optical fiber arrays showed optical loss variations within 0.4 dB under thermal cycling test and high temperature test.

Does mini-implant-supported rapid maxillary expansion cause less root resorption than traditional approaches? A micro-computed tomography study

  • Alcin, Rukiye;Malkoc, Siddik
    • The korean journal of orthodontics
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    • v.51 no.4
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    • pp.241-249
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    • 2021
  • Objective: This study aimed to evaluate the volume, amount, and localization of root resorption in the maxillary first premolars using micro-computed tomography (micro-CT) after expansion with four different rapid maxillary expansion (RME) appliances. Methods: In total, 20 patients who required RME and extraction of the maxillary first premolars were recruited for this study. The patients were divided into four groups according to the appliance used: mini-implant-supported hybrid RME appliance, hyrax RME appliance, acrylic-bonded RME appliance, and full-coverage RME appliance. The same activation protocol (one activation daily) was implemented in all groups. For each group, the left and right maxillary first premolars were scanned using micro-CT, and each root were divided into six regions. Resorption craters in the six regions were analyzed using special CTAn software for direct volumetric measurements. Data were statistically analyzed using Kruskal-Wallis one-way analysis of variance and Mann-Whitney U test with Bonferroni adjustment. Results: The hybrid expansion appliance resulted in the lowest volume of root resorption and the smallest number of craters (p < 0.001). In terms of overall root resorption, no significant difference was found among the other groups (p > 0.05). Resorption was greater on the buccal surface than on the lingual surface in all groups except the hybrid appliance group (p < 0.05). Conclusions: The findings of this study suggest that all expansion appliances cause root resorption, with resorption craters generally concentrated on the buccal surface. However, the mini-implant-supported hybrid RME appliance causes lesser root resorption than do other conventional appliances.

Optimization of Design Pressure Ratio of Positive Displacement Expander for Engine Waste Heat Recovery of Vehicle (자동차 엔진 폐열 회수 동력시스템에서 용적형 팽창기의 설계 팽창비 최적화)

  • Kim, Young Min;Shin, Dong Gil;Kim, Chang Gi;Woo, Se Jong;Choi, Byung Chul
    • Journal of Energy Engineering
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    • v.21 no.4
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    • pp.411-418
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    • 2012
  • The effect of built-in volume ratio of expander on the performance of a two-loop Rankine cycle system for engine waste heat recovery of vehicle has been investigated. In the case of positive displacement expander in the various operating condition of the vehicle, it can operate in both under-expansion and over-expansion conditions. Therefore, the analysis of off-design performance for the expander is very important. Furthermore, the volume and weight of the expander as well as the efficiency must be considered in the optimization of the expander. This study shows that the built-in volume ratio of expander causing under-expansion at a target condition is more desirable considering the off-design performance and size of the expander, based on the simple modeling of off-design operation of the expander.

Comparison of the effects of rapid maxillary expansion and alternate rapid maxillary expansion and constriction protocols followed by facemask therapy

  • Ozbilen, Elvan Onem;Yilmaz, Hanife Nuray;Kucukkeles, Nazan
    • The korean journal of orthodontics
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    • v.49 no.1
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    • pp.49-58
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    • 2019
  • Objective: The aim of this retrospective study was to evaluate and compare the changes in the pharyngeal airway (PA), maxillary sinus volume, and skeletal parameters after rapid maxillary expansion (RME) and alternate rapid maxillary expansion and constriction (Alt-RAMEC) followed by facemask (FM) therapy. Methods: The records of 40 patients with skeletal Class III malocclusion due to maxillary retrognathism were collected, and the patients were assigned into two groups. The first group comprised 8 male and 12 female patients (mean age, $10.0{\pm}1.1years$) treated using RME/FM for an average of 10 months. The second group comprised 10 male and 10 female patients (mean age, $9.64{\pm}1.3years$) treated using Alt-RAMEC/FM for an average of 12 months. Cone-beam computed tomography images acquired before (T0) and after treatment (T1) were evaluated. Results: Regarding the skeletal effects, significant differences between the groups were the increase in ANS-HRP (perpendicular distance of ANS to the horizontal reference plane, 0.99 mm, p <0.05) in the Alt-RAMEC/FM group and the decrease in PP-SN (palatal plane to Sella-Nasion plane, $0.93^{\circ}$, p < 0.05) in the RME/FM group. Maxillary sinus volumes increased significantly in both the groups, and the increase was statistically significantly higher in the Alt-RAMEC/FM group. Although no significant intergroup differences were observed in PA volumes, both lower ($1,011.19mm^3$) and total ($1,601.21mm^3$), PA volume increased significantly in the Alt-RAMEC/FM group. Conclusions: The different expansion devices and protocols used with FM therapy do not seem to affect the forward movement of the maxilla and PA volumes. In contrast, the increase in maxillary sinus volume was greater in the Alt-RAMEC/FM protocol.