• Title/Summary/Keyword: Physical stability

Search Result 2,314, Processing Time 0.025 seconds

Rheological properties of flour dough containing roasted rice bran (볶은 쌀겨를 첨가한 밀가루 반죽의 rheology 특성)

  • Shin, Hyun-Kwang;Lee, Jeong-Hoon;Chung, Koo-Chun;Lee, Si-Kyung
    • Korean Journal of Food Science and Technology
    • /
    • v.50 no.6
    • /
    • pp.587-593
    • /
    • 2018
  • This study was carried out to investigate the effect of roasted rice bran (RRB) on the rheological properties of bread dough. According to farinograph analysis, the consistency of the control sample was greatest. There were no significant differences in water absorption (p<0.05). Lower values of development time, stability, and time to breakdown, which were affected, by the addition of RRB, were observed for RRB-containing dough samples, compared to the control dough sample. Addition of RRB significantly increased the mixing tolerance index (MTI). According to rheofermentometer analysis, the values of H'm, $T^{\prime}_1$, and retention volume decreased with increase in the amount of RRB added. According to the rapid visco analyzer (RVA) analysis, peak viscosity, holding strength, and setback values were greater in the control than in the RRB-containing samples. The addition of RRB to the flour influenced rheological properties like fermentation volume and acidity. The total acidity increased with the increase in the amount of RRB added. The present study has indicated that there was no significant difference between the rheological properties of the control and 5% RRB-containing dough samples. Therefore, the addition of 5% RRB could be an effective way to produce functional flour bread without affecting its desirable physical properties.

Soil Properties of Granitic Weathered Soils in the Landslide-prone Areas in Seoul (서울지역 화강암 풍화토 토층지반의 토질특성)

  • Kim, Kyeong-Su
    • The Journal of Engineering Geology
    • /
    • v.29 no.1
    • /
    • pp.23-35
    • /
    • 2019
  • Landslides occur due to heavy rainfall in the summer season. Some of water may infiltrate into the ground; it causes a high saturation condition capable of causing a landslide. Soil properties are crucial in estimating slope stability and debris flow occurrence. The main study areas are Gwanaksan, Suraksan and Bukhansan (Mountain) in Seoul. A total of 44 soil samples were taken from the study area; and a series of geotechnical tests were performed. Physical and mechanical properties were obtained and compared based on region. As a result, among well-graded soils, they are classified as a clayey sand. Coarse-grained and fine-grained contents are approximately 95% and 5%, respectively, with very low amount of clay content. Density, liquid limit and dry unit weight are ranged in $2.62{\sim}2.67g/cm^3$, 27.93~38.15% and $1.092{\sim}1.814g/cm^3$. Cohesion and internal friction angle are 4 kPa and $35^{\circ}$ regardless of mountain area. Coefficient of permeability is varied between $3.07{\times}10^{-3}{\sim}4.61{\times}10^{-2}cm/sec$; it means that it results in great seepage. Permeability is inversely proportional to the uniformity coefficient and is proportional to the effective particle size. In the formal case, there was a difference by mountain area, while in the latter, the tendency was almost similar.

Evaluation of Access Control Function of the Standard Records Management System (표준기록관리시스템 기능 평가 접근관리 기능을 중심으로)

  • Park, Min-Yung
    • The Korean Journal of Archival Studies
    • /
    • no.38
    • /
    • pp.3-35
    • /
    • 2013
  • The physical access or control of records with material entities is relatively easy. However, in the case of electronic records, due to its heightened applicative aspect that allows anyone with the authority to have access over the data, it requires an appropriate standard and stability to ensure the authenticity and integrity of electronic records. This study performed functional evaluation by extracting the minimum critical items from the national functional requirements documents and standards to explore the access control function that play an important role for the standard records management system to maintain quality requirements of electronic records. Based on this checklist, it evaluates whether the standard records management system properly carries out the access control function and investigates the current condition of application to practical records management work. Records managers generally do not use access control function, which may be because they do not feel the necessity, since the application of records management system is not yet actively promoted. In order for the standard records management system to be developed to become a more active system, it requires system improvement as well as considerations for below factors: First, although the necessity of establishing access control conditions is already recognized, it requires a clear stipulation of the regulation. Second, measures must be taken to implement access control in the records management system through document security solution. Third, it requires self-reflection of records manager, who utilizes the records management system. Instead of placing all responsibility on the National Archives, which established the system, professionals must further develop the system through continuous evaluation and improvement. Finally, a general discussion is required to publicize the issue of functional improvement of records management system. Although there is a bulletin board already created for this purpose, its users are extremely limited and it only deals with current problems. A space in online as well as in offline is required to solve the fundamental problems and exchange opinions.

Studies in Biomechanical Properties on Brain-spinal Cord Response Mechanism by Human Posture Control Ability (자세조절능력에 따른 뇌-척수 신경 반응기전의 역학적 해석)

  • Yoo, Kyoung-Seok
    • 한국체육학회지인문사회과학편
    • /
    • v.58 no.6
    • /
    • pp.449-459
    • /
    • 2019
  • The purpose of this study is to identify how postural mechanics affects postural control on balance and stability by using frequency analysis technique from the kinematic data acquired during the one leg standing posture. For this purpose, the experimental group consisted of two groups, the normal group (n=6) and the national Gymnastics group (n=6). Displacement data of CoP were analyzed by frequency analysis of rambling (RM) and trembling (TR) by FFT signal processing. As a results, there was a significant difference in evaluating the stabilization index between the two groups with the eyes open and closed one leg stnading (p <.05). The cause of the difference was found to be the output of the maximum amplitude of RM (f1) and TR (f2) (p <.05). In particular, in the low frequency RM of 8-9 Hz, which is a natural frequency of signal wave involved in postural feedback feedback, the main frequency appeared to be performs the exercise mechanism of stable brain posture control. And in the high frequency TM of 120-135 Hz, it is considered that the adaptation of the reflective muscle response is minimized to minimize posture shaking. In conclusion, this study provides evidence for the intrinsic main frequencies according to the postural control ability which affects the CNS in one leg standing.

Fandom-Persona Design based on Social Network Analysis (소셜 네트워크 분석을 이용한 팬덤 페르소나 디자인)

  • Sul, Sanghun;Seong, Kihun
    • Journal of Internet Computing and Services
    • /
    • v.20 no.5
    • /
    • pp.87-94
    • /
    • 2019
  • In this paper, the method of analyzing the unformatted data of consumers accumulated on social networks in the era of the Fourth Industrial Revolution by utilizing data from the service design and social psychology aspects was proposed. First, the fandom phenomenon, which shows subjective and collective behavior in a space on a social network rather than physical space, was defined from a data service perspective. The fandom model has been transformed into a collective level of customer Persona that has been analyzed at a personal level in traditional service design, and social network analysis that analyzes consumers' big data has been presented as an efficient way to pattern and visually analyze it. Consumer data collected through social leasing were pre-processed by column based on correlation, stability, missing, and ID-ness. Based on the above data, the company's brand strategy was divided into active and passive interventions and the effect of this strategic attitude on the growth direction of the consumer's fandom community was analyzed. To this end, the fandom model of consumers was proposed by dividing it into four strategies that the brand strategy had: stand-alone, decentralized, integrated and centralized, and the fandom shape of consumers was proposed as a growth model analysis technique that analyzes changes over time.

Fluoro-illite/polypropylene Composite Fiber Formation and Their Thermal and Mechanical Properties (불소화 일라이트/폴리프로필렌 복합섬유 형성 및 열 및 기계적 특성)

  • Jeong, Euigyung;Lee, Young-Seak
    • Applied Chemistry for Engineering
    • /
    • v.22 no.5
    • /
    • pp.467-472
    • /
    • 2011
  • This study investigated illite/polypropylene (PP) composite filament formation via melt-spinning and evaluated their physical properties to prepare functional fibers using natural materials. When composite filaments were formed, the composite filaments exhibited smaller fiber diameters compared to that of neat PP filament because of the lubricant effect of illite induced by its layered structure. Moreover, fluorination effect increased interfacial affinity and dispersion in the polymer, resulting in smaller diameter of fluorinated illite/PP composite filament, which was 2/3 of the neat PP filament diameter. Addition of raw and fluorinated illite improved thermal stability of illite/PP composite filament. Raw illite/PP composite filament cannot be used for a practical application, because it broke during drawing process, whereas the fluorinated illite/PP composite filament can be used for a practical application, because it exhibited similar tensile strength of the neat PP filament and 50% increased modulus. Even with improved illite/PP interfacial affinity and illite dispersion in the polymer, illite/PP composite filament formed microcomposite, because non-expandable illite had strongly bound layers, resulting in only a little illite exfoliation and PP intercalation into illite.

Synthesis and Characterization of Zeolite Using Water Treatment Sludge (정수슬러지를 이용한 제올라이트의 합성 및 특성연구)

  • Ko, Hyun Jin;Ko, Yong Sig
    • Clean Technology
    • /
    • v.26 no.4
    • /
    • pp.263-269
    • /
    • 2020
  • Zeolite was synthesized hydrothermally using the water-treatment sludge, and the effects of various synthesis parameters like reaction temperature, reaction time, and Na2O/SiO2 molar ratio on the crystallization of zeolite were investigated. Crystal structure, physical property, and thermal stability of zeolite crystals were characterized by X-ray powder diffraction, FTIR spectroscopy, BET nitrogen adsorption, and TGA measurements. The removal efficiencies of nitrogen in ammonia, heavy metal ions, and TOC were calculated to evaluate zeolite's adsorption capacity. The primary chemical composition of water-treatment sludge was 28.79% Al2O3 and 27.06% SiO2. The zeolites were synthesized by merely employing the water-treatment sludge as silica and alumina sources without additional chemicals. Zeolite crystals synthesized through the water-treatment sludge were confirmed as an A-type zeolite structure. Zeolite A had the highest crystallinity obtained from a gel with the molar composition 2.1Na2O-Al2O3-1.6SiO2-65H2O after 5 h at a temperature of 90 ℃. The specific surface area of zeolite obtained was 55 ㎡ g-1, which was higher than commercial zeolite A. The removal efficiency of nitrogen in ammonia was 68% after 3 h of reaction time, while the removal efficiencies of Pb2+ and Cd2+ ions were 99.1% and 99.3%, respectively. These results indicate active ion exchange between Pb2+ or Cd2+ ion and Na+ ion in the zeolite framework. The adsorption experiments on the different zeolite addition conditions were performed for 3 h with 300 ppm humic acid. Based on the results, TOC's highest efficiency was 83% when 5 g of zeolite was added.

The Mechanical Properties of SMA Concrete Mixture Using Steel Slag Aggregate (제철 슬래그 골재를 이용한 SMA 혼합물의 역학적 특성)

  • Kim, Hyeok-Jung;Na, Il-Ho
    • Journal of the Korean Recycled Construction Resources Institute
    • /
    • v.9 no.1
    • /
    • pp.109-116
    • /
    • 2021
  • In order to replace mineral aggregate used as road pavement materials with steel slag aggregate, this present study evaluated mechanical properties of SMA Concrete mixtures using steel slag aggregate as oxidized slag from electric furnace in iron works. The variables of this experiment are the aggregate type of mineral and steel slag and the sieve sized of 10mm and 13mm. The physical properties inclu ding the specific gravity and absorption rate etc. of the slag aggregate mixtu res satisfied the KS standard as asphalt mixtu re. As a resu lt of evalu ating the mechanical properties of the asphalt mixtures, the optimum asphalt content of the slag aggregate mixtures were lower than that of the mineral aggregate mixtures, but other quality standards were all satisfied. In the deformation strength evaluation, the slag aggregate mixtures were measu red slightly higher than that of the mineral aggregate mixtu res, and the dynamic stability test satisfied the 2,000pass/mm standard value in all specimens. And, the moduli of resilient of the slag aggregate mixtures showed an improved value compared with the mineral aggregate mixtures. Therefore, as the resilient rate of the slag aggregate mixtures improved, it is speculated that there will be an effect of improving public performance according to the repeated traffic load of the vehicle.

The Influence of Middle-aged and Elderly Adult Learning on the Happiness of Adaptation to College Life (중고령 성인학습자의 대학생활적응이 행복감에 미치는 영향)

  • An, Geun-Pil;Kim, Moon-seup;Kim, Jin-Sook
    • The Journal of the Convergence on Culture Technology
    • /
    • v.7 no.3
    • /
    • pp.255-260
    • /
    • 2021
  • This study tried to investigate the effects of the adaptation of middle-aged and elderly adult learners to college life on happiness. For this purpose, a questionnaire survey and analysis were conducted on 321 middle-aged and older adults studying at two-year and four-year colleges in Daegu and Gyeongbuk Province, and the results are as follows. First, college life adaptation according to the general characteristics of middle-aged and elderly learners are higher for those in their 50s and 2nd grade in good health condition. Happiness was the highest women, 60s and those in the form of households where only couples live. Second, there is a static correlation between the adaptation of middle-aged and elderly adult learners to college life and happiness, and the correlation between satisfaction with internal growth and satisfaction with meaning was the highest. Third, it was found that middle-aged and elderly adults' adaptation to college life influenced happiness, and the adaptation to adult student relationships, which is the lower part of the adaptation to college life, had the greatest impact on happiness. The above research results suggest that the various positive experiences experienced in university life can affect happiness by easing student relationships, psychological stability, and physical tension, and improving one's own satisfaction with internal growth.

Fabrication of complete denture using 3D printing: a case report (3D 프린팅을 이용한 양악 총의치 제작 증례)

  • Lee, Eunsu;Park, Chan;Yun, Kwidug;Lim, Hyun-Pil;Park, Sangwon
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.60 no.2
    • /
    • pp.202-210
    • /
    • 2022
  • Recently with the advance in digital dentistry, the fabrication of dentures using computer-aided design and computer-aided manufacturing (CAD-CAM) is on the rise. The denture designed through a CAD software can be produced in a 3-dimensional manufacturing process. This process includes a subtractive processing method such as milling and an additive processing method such as 3D printing and in which it can be applied efficiently in more complex structures. In this case, complete dentures were fabricated using Stereolithography (SLA)-based 3D printing to shorten the production time and interval of visits in patient with physical disabilities due to cerebral infarction. For definitive impression, the existing interim denture was digitally replicated and used as an individual tray. The definitive impression obtained with polyvinyl siloxane impression material was including information about the inclination and length of the maxillary anterior teeth, vertical dimension, and centric relation. In addition, facial scan data with interim denture was obtained so that it can be used as a reference in determination of the occlusal plane and in arrangement of artificial teeth during laboratory work. Artificial teeth were arranged through a CAD program, and a gingival festooning was performed. The definitive dentures were printed by SLA-based 3D printer using a FDA-approved liquid photocurable resin. The denture showed adequate retention, support, and stability, and results were satisfied functionally and aesthetically.