• Title/Summary/Keyword: apparent stress

Search Result 304, Processing Time 0.043 seconds

Physicochemical, Microbial, Rheological, and Sensory Properties of Yogurt Added with Yuza Pectin Extract (유자펙틴 추출물을 첨가한 요구르트의 이화학적, 미생물학적, 유변학적 및 관능적 품질 특성)

  • Yoon, Mi-Ra;Seo, Jeong-Yun;Ryu, Ga-Eun;Kim, Yeon-Ho;Seo, Moon-Cho;Chang, Yoon Hyuk
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.45 no.4
    • /
    • pp.562-568
    • /
    • 2016
  • This study investigated the effects of Yuza pectin extract (0, 0.1, 0.15, and 0.2%, w/v) on the physicochemical, microbial, rheological, and sensory properties of yogurt. Pectin extract was extracted from Yuza peel by using citrate after juicing the flesh. The total sugar content of Yuza pectin was 89.07%. The pH of Yuza pectin extract-added yogurt was 4.43. All Yuza pectin extract-added yogurt samples showed shear-thinning flow behaviors (n=0.33~0.44). The values for apparent viscosity ($0.34{\sim}0.47Pa{\cdot}s$), consistency index ($4.48{\sim}10.25Pa{\cdot}s^n$), yield stress (6.56~17.61 Pa), storage modulus (47.96~75.21 Pa), and loss modulus (19.79~26.06 Pa) for 0.1~0.2% (w/v) Yuza pectin extract-added yogurt were considerably higher than those of the control. These result indicated that Yuza pectin extract could enhance steady and dynamic shear rheological properties of yogurt. The sensory scores of Yuza pectin extract-added yogurt were higher than those of the control.

Rheological Properties of Cross-Linked Potato Starch (가교화 감자전분의 유변학적 특성)

  • Choi, Moonkyeung;Heo, Hye Mi;Jin, Yong-Ik;Chang, Dong-Chil;Kim, Misook;Lee, Youngseung;Chang, Yoon Hyuk
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.45 no.10
    • /
    • pp.1525-1531
    • /
    • 2016
  • The objective of the present study was to investigate the rheological properties of potato starch cross-linked with different concentrations (0, 0.125, 0.25, and 0.5%, w/v) of cross-linking agents (10 g of adipic acid and 40 g of acetic anhydride). Cross-linked potato starch dispersions showed shear-thinning behaviors (n=0.43~0.63) at $25^{\circ}C$. Apparent viscosity (${\eta}_{a,100}$), consistency index (K), and yield stress (${\sigma}_{oc}$) significantly increased with an increase in the concentrations of cross-linking agents from 0.125 to 0.5% (w/v). Storage modulus (G') and loss modulus (G'') increased, whereas complex viscosity (${\eta}^*$) was reduced with increasing frequency (${\omega}$) from 0.63 to 62.8 rad/s. Magnitudes of G' and G'' for cross-linked potato starch were significantly increased with an elevation in the concentrations of cross-linking agents. G' values of cross-linked potato starches were significantly higher than G'', indicating that the starches had more elastic properties than viscous properties. Cox-Merz rule was not applicable to potato starch dispersions.

Rheological Properties of Calrose Rice and Effect of Thawing Methods on Quality Characteristics of Frozen Turmeric Rice (칼로스 쌀의 유변학적 특성과 이로 제조된 냉동 강황밥의 해동방법에 따른 품질특성 변화)

  • Kim, So Yeon;Choi, Yu Ra;Kim, Kyeong Seop;Lee, Sang Jun;Chang, Yoon Hyuk
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.46 no.6
    • /
    • pp.771-777
    • /
    • 2017
  • This study investigated the rheological properties of Calrose rice flour dispersions as well as the effects of different thawing methods (steamer, smart oven, and microwave oven) on quality characteristics of frozen turmeric rice. Apparent viscosity, consistency index, and yield stress significantly increased at higher rice flour concentrations. Magnitudes of storage modulus and loss modulus significantly increased with elevation of rice flour concentration. Frozen turmeric rice thawed using a steamer had the highest moisture content and largest size (length, width, and thickness) among all thawing methods. The L values of turmeric rice after thawing using a steamer was significantly higher than those of other thawing methods. The a value of turmeric rice after thawing using a steamer was significantly lower than those of other thawing methods. Textural properties (hardness, adhesiveness, springiness, cohesiveness, brittleness, and chewiness) of frozen turmeric rice after thawing using a steamer were significantly lower than those of other thawing methods. Therefore, it can be concluded that frozen turmeric rice after thawing using a steamer might be desirable for improvement of texture.

Study on the Potential of Phytoremediation using Wild Plants for Heavy Metal Pollution (중금속 오염에 대한 Phytoremediation 용 야생식물 연구)

  • Kang, Byeung-Hoa;Shim, Sang-In;Lee, Sang-Gak;Kim, Kwang-Ho;Chung, Il-Min
    • Korean Journal of Environmental Agriculture
    • /
    • v.17 no.4
    • /
    • pp.312-318
    • /
    • 1998
  • The potentials of some Korean wild plants as a phytoremediator for cleaning heavy metal pollution were measured. Several plant species, Ambrosia trifida, Brassica juncea, Rumex crispus, and Abutilon theophrasti screened previously for phytoremediator were treated with cadmium and copper solution. In order to know the growth response to heavy metal stress, the plants were cultivated in hydroponic system containing heavy metals with different concentration. To know the effects of heavy metals on emergence and seedling growth, seeds of 4 species were sown in the pot and watered with heavy metal solution adjusted pH to 6.5, 5.5, and 4.5. A proposed species as potential phytoremediator, A. trifida, showed tolerance to $20{\mu}mol/L$ Cd and $80{\mu}mol/L$ Cu in nutrient solution without apparent growth reduction, and up to $100{\mu}mol/L$ Cd and $400{\mu}mol/L$ Cu without critical visual injury. Up to 311mg/kg of Cd and 369mg/kg were accumulated in dried aerial part in A. trifida. In contrast, A. theophrasti showed injury at $400{\mu}mol/L$ Cu. Significant differences were shown in Cu accumulation among the four species. A. trifida had much higher concentrations of Cd in the shoot, whereas R, crispus accumulated higher concentrations of Cd in the shoot. Testing plant species showed reduced emergence rate with heavy metal treatment. When pH was lowered, the emergence and seedling growth were affected severely with heavy metal. We can suggested that A. trifida was the most proper species for phytoremediation in heavy metal-polluted regions.

  • PDF

Testing The Healing Environment Conditions for Nurses with two Independent Variables: Visibility Enhancement along with Shortening the Walking Distance of the Nurses to Patient - Focused on LogWare stop sequence and space syntax for U-Shape, L- Shape and I-Shape NS-

  • Shaikh, Javaria Manzoor;Park, Jae Seung
    • KIEAE Journal
    • /
    • v.15 no.2
    • /
    • pp.19-26
    • /
    • 2015
  • Purpose: Maximizing human comfort in design of medical environments depends immensely on specialized architects particularly critical care design; the study proposes Evidence-Based Design as an apparent analog to Evidence-Based Medicine. Healthcare facility designs are substantially based on the findings of study in an effort to design environments that augment care by improving patient safety and being therapeutic. On SPSS (Statistical Package for Social Science) t-test is applied to simulate two independent variables of PDR (Pre Design-Research) and POE (Post- Occupancy Evaluation). PDR is conducted on relatively new hospital Hallym University Dongtan Sacred Heart Hospital to analyse visibility from researchers' point of view, here the ICU is arranged in I-Shape. POE is applied on Dongguk University Ilsan Hospital to simulate walking on LogWare where two NS are designed based on L- Shape and Seoul St. Mary's Hospital, The Catholic University of Korea where five NS are functional for ICU Intensive Care Unit, Surgical Intensive Care Unit (SICU), Medical Intensive Care Unit (MICU), Critical Care Unit (CCU), Korean Oriental Medical Care Unit which are mostly arranged in U-Shape, and walking pattern is recognized to be in a zigzag path. Method: T-Test is applied on two dependent communication variables: walkability and visibility, with confidence interval of 95%. This study systematically analyses the Nurse Station (NS) typo-morphology, and simulates nurse horizontal circulation, by computing round route visits to patient's bed, then estimating minimum round route on LogWare stop sequence software. The visual connectivity is measured on depth map graphs. Hence the aim is to reduce staff stress and fatigue for better patients care by minimizing staff horizontal travel time and to facilitate nurse walk path and support space distribution by increasing effectiveness in delivering care. Result: Applying visibility graph and isovist field on space syntax on I- Shape, L- Shape and U- Shape ICU (SICU, MICU and CCU) configuration, I-shape facilitated 20% more patients in linear view as they stir to rise from their beds from nurse station compared to U-shape. In conclusion, it was proved that U-Shape supply minimum walking and maximum visibility; and L shape provides just visibility as the nurse is at pivot. I shape provides panoramic view from the Nurse Station but very rigorous walking.

Site responses of Japanese stations near the epicenter and Korean stations for the Fukuoka earthquake (후쿠오카 지진('05. 3. 20, $M_{JMA}=7.0$)에 대한 일본 인근 지진관측소와 국내 지진관측소의 주파수응답특성 비교)

  • Yun Kwan-Hee;Park Dong-Hee;Chang Chun-Jung;Choi Weon-Hack;Lee Dae-Soo
    • 한국지구물리탐사학회:학술대회논문집
    • /
    • 2005.05a
    • /
    • pp.79-86
    • /
    • 2005
  • The apparent source spectrum of the Fukuoka earthquake is estimated at the seismic basement by removing from the observed spectra at Korean seismic stations the path and site responses that were previously revealed through inversion process applied to large spectral D/B accumulated until 2004. The approximate source spectrum is also estimated by using data recorded near the epicenter from various Japanese seismic networks and compared with the Korean source spectrum. The comparison result shows that there is good agreement among source spectra estimated based on the data from seismic networks of Korea at large distances (190km

  • PDF

Thickness Effect on the Compressive Strength of T800/924C Carbon Fibre-Epoxy Laminates (T800/924C 탄소-에폭시 복합재판의 압축강도에 대한 두께 효과)

  • Lee, J.;C. Kong;C. Soutis
    • Composites Research
    • /
    • v.17 no.4
    • /
    • pp.7-17
    • /
    • 2004
  • In this study, the effect of laminate thickness on the compressive behaviour of composite materials is investigated through systematic experimental work using the stacking sequences, $[O_4]_{ns},{\;}[45/0/-45/90]_{ns}$ and $[45_n/0_n/-45_n/90_n]_s$ (n=2 to 8). Parameters such as fibre volume fraction, void content, fibre waviness and interlaminar stresses, influencing compressive strength with increasing laminate thickness are also studied experimentally and theoretically. Furthermore the stacking sequence effects on failure strength of multidirectional laminates are examined. For this purpose, two different scaling techniques are used; (1) ply-level technique $[45_n/0_n/-45_n/90_n]s$ and (2) sublaminate level technique $[45/0/-45/90]_{ns}$. An apparent thickness effect existes in the lay-up with blocked plies, i.e. unidirectional specimens ($[O_4]_{ns}) and ply-level scaled multidirectional specimens ($[45_n/0_n/-45_n/90_n]_s$). Fibre waviness and void content are found to be main parameters contributing to the thickness effect on the compressive failure strength. However, the compressive strength of the sublaminate level scaled specimens ($[45/0/-45/90]_{ns}$) is almost unaffected regardless of the specimen thickness (since ply thickness remains constant). From the investigation of the stacking sequence effect, the strength values obtained from the sublaminate level scaled specimens are slightly higher than those obtained from the ply level scaled specimens. The reason for this effect is explained by the fibre waviness, void content, free edge effect and stress redistribution in blocked $0^{\circ}$ plies and unblocked $0^{\circ}$ plies. The measured failure strengths are compared with the predicted values.

Rheological Properties of Hot-Water Extractable Concentrates of Boxthorn (Lycii Fructus) and Mixed Boxthorn (구기자 및 혼합구기자 열수 추출 농축액의 리올로지적 특성)

  • Lee, Boo-Yong;Kim, Heung-Man;Kim, Chul-Jin;Park, Moo-Hyun
    • Korean Journal of Food Science and Technology
    • /
    • v.24 no.6
    • /
    • pp.597-602
    • /
    • 1992
  • To improve utilization of boxthorn (Lycii Fructus), the boxthron and mixed boxthron (Lycii Fructus, Schizandrae Fructus, Corni Fructus, Zizyphi Fructus, Zingiberis Rhizoma, Cinnamami Cortex) hot-water extractable concentrates were prepared by vaccum evaporation and its rheological properties were investigated. The rheological properties of concentrates $(20{\sim}50^{\circ}Bx)$ followed power low model and showed a pseudoplastic behavior at the temperature range of $20{\sim}60^{\circ}C$. The apparent viscosity of $20^{\circ}Bx$, $30^{\circ}Bx$, $40^{\circ}Bx$ and $50^{\circ}Bx$ boxthron hot-water extractable concentrate was 0.0074 Pa s, 0.0175 Pa s, 0.0431 Pa s and 0.0988 Pa s, that of mixed boxthorn hot-water extractable concentrate was 0.0099 Pa s, 0.0328 Pa s, 0.0720 Pa s and 0.1940 Pa s at $20^{\circ}C$ and 1500 l/s, respectively. The yield stress of boxthron and mixed boxthron hot-water extractable concentrates ranged from 0.045 to 6.253 Pa and from 0.022 to 8.891 Pa, respectively. The activation energy for the flow of boxthron and mixed boxthorn hot-water extractable concentrates increased from 1.6182 to $2.0543{\times}10^7\;J/kg{\cdot}mol$ and from 1.7057 to $2.1462{\times}10^7\;J/kg{\cdot}mol$ with the concentrations of concentrates, respectively.

  • PDF

Self-Sensing of Single Carbon Fiber/Carbon Nanotube-Epoxy Composites Using Electro-Micromechanical Techniques and Acoustic Emission (전기적-미세역학시험법과 음향방출을 이용한 단일 탄소섬유/탄소나노튜브-에폭시 나노복합재료의 자체-감지능)

  • Park, Joung-Man;Jang, Jung-Hoon;Wang, Zuo-Jia;Kwon, Dong-Jun;Park, Jong-Kyu;Lee, Woo-Il
    • Journal of the Korean Society for Nondestructive Testing
    • /
    • v.30 no.5
    • /
    • pp.411-422
    • /
    • 2010
  • Self-sensing on micro-failure, dispersion degree and relating properties, of carbon nanotube(CNT)/epoxy composites, were investigated using wettability, electro-micromechanical technique with acoustic emission(AE). Specimens were prepared from neat epoxy as well as composites with untreated and acid-treated CNT. Degree of dispersion was evaluated comparatively by measuring volumetric electrical resistivity and its standard deviation. Apparent modulus containing the stress transfer was higher for acid-treated CNT composite than for the untreated case. Applied cyclic loading responded well for a single carbon fiber/CNT-epoxy composite by the change in contact resistivity. The interfacial shear strength between a single carbon fiber and CNT-epoxy, determined in a fiber pullout test, was lower than that between a single carbon fiber and neat epoxy. Regarding on micro-damage sensing using electrical resistivity measurement with AE, the stepwise increment in electrical resistivity was observed for a single carbon fiber/CNT -epoxy composite. On the other hand, electrical resistivity increased infinitely right after the first carbon fiber breaks for a single carbon fiber/neat epoxy composite. The occurrence of AE events of added CNT composites was much higher than the neat epoxy case, due to micro failure at the interfaces by added CNTs.

Performance Responses, Nutrient Digestibility, Blood Characteristics, and Measures of Gastrointestinal Health in Weanling Pigs Fed Protease Enzyme

  • Tactacan, Glenmer B.;Cho, Seung-Yeol;Cho, Jin H.;Kim, In H.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.29 no.7
    • /
    • pp.998-1003
    • /
    • 2016
  • Although exogenous protease enzymes have been used in poultry diets quite extensively, this has not been the case for pig diets. In general, due to their better gut fermentative capacity and longer transit time, pigs have greater capacity to digest dietary proteins than poultry. However, in early-weaned piglets, the stress brought about by weaning adversely affects the digestion of dietary proteins. Therefore, a study was conducted to determine the effects of a commercial protease enzyme in weanling pigs. Indices of growth, nutrient digestibility, blood profiles, fecal microflora, fecal gas emission and fecal scores were measured during the study. A total of 50 weanling pigs ($6.42{\pm}0.12kg$) at 28 d of age were randomly assigned to receive 1 of 2 dietary treatments: i) control diet (corn-soy based) with no supplemental protease (CON), and ii) control diet+200 g/ton protease (PROT) for 42 d. A completely randomized design consisting of 2 treatments, 5 replicates, and 5 pigs in each replicate was used. Growth performance in terms of body weight ($27.04{\pm}0.38kg$ vs $25.75{\pm}0.39kg$; p<0.05) and average daily gain ($491{\pm}7.40g$ vs $460{\pm}7.46g$; p<0.05) in PROT fed pigs were increased significantly, but gain per feed ($0.700{\pm}0.01$ vs $0.678{\pm}0.01$; p>0.05) was similar between treatments at d 42. Relative to CON pigs, PROT fed pigs had increased (p<0.05) apparent total tract digestibility ($84.66%{\pm}0.65%$ vs $81.21%{\pm}1.13%$ dry matter and $84.02%{\pm}0.52%$ vs $80.47%{\pm}1.22%$ nitrogen) and decreased (p<0.05) $NH_3$ emission ($2.0{\pm}0.16ppm$ vs $1.2{\pm}0.12ppm$) in the feces at d 42. Except for a decreased (p<0.05) in blood creatinine level, no differences were observed in red blood cell, white blood cell, lymphocyte, urea nitrogen, and IgG concentrations between treatments. Fecal score and fecal microflora (Lactobacillus and E. coli) were also similar between CON and PROT groups. Overall, the supplementation of protease enzyme in weanling pigs resulted in improved growth rate and nutrient digestibility. Exogenous protease enzyme reduced fecal $NH_3$ emission, thus, potentially serving as a tool in lowering noxious gas contribution of livestock production in the environment.