• Title/Summary/Keyword: Specific rotation

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Synthesis and Properties of Novel Flame-Retardant and Thermally Stable Poly(amideimide)s from N,N'-(bicyclo[2,2,2]oct-7-ene-tetracarboxylic)-bis-L-amino Acids and Phosphine Oxide Moiety by Two Different Methods

  • Faghihi, Khalil;Hajibeygi, Mohsen;Shabanian, Meisam
    • Macromolecular Research
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    • v.17 no.10
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    • pp.739-745
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    • 2009
  • N,N'-(bicyclo[2,2,2]oct-7-ene-tetracarboxylic)-bis-L-amino acids 3a-g were synthesized by the condensation reaction of bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride 1 with two equimolars of Lalanine 2a, L-valine 2b, L-leucine 2c, L-isoleucine 2d, L-phenyl alanine 2e, L-2-aminobutyric acid 2f and L-histidine 2g in an acetic acid solution. Seven new poly(amide-imide)s PAIs 5a-g were synthesized through the direct polycondensation reaction of seven chiral N,N'-(bicyclo[2,2,2]oct-7-ene-tetracarboxylic)-bis-L-amino acids 3a-g with bis(3-amino phenyl) phenyl phosphine oxide 4 by two different methods: direct polycondensation in a medium consisting of N-methyl-2-pyrrolidone (NMP)/triphenyl phosphite (TPP)/calcium chloride ($CaCl_2$/pyridine (py), and direct polycondensation in a tosyl chloride (TsCl)/pyridine (py)/N,N-dimethylformamide (DMF) system. The polymerization reaction produced a series of flame-retardant and thermally stable poly(amide-imide)s 5a-g with high yield. The resulted polymers were fully characterized by FTIR, $^1H$ NMR spectroscopy, elemental analyses, inherent viscosity, specific rotation and solubility tests. Data obtained by thermal analysis (TGA and DTG) revealed that the good thermal stability of these polymers. These polymers can be potentially utilized in flame retardant thermoplastic materials.

Leakage Flow Influence on SHF pump model performances

  • Dupont, Patrick;Bayeul-Laine, Annie-Claude;Dazin, Antoine;Bois, Gerard;Roussette, Olivier;Si, Qiaorui
    • International Journal of Fluid Machinery and Systems
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    • v.8 no.3
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    • pp.193-201
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    • 2015
  • This paper deals with the influence of leakage flow existing in SHF pump model on the analysis of internal flow behaviour inside the vane diffuser of the pump model performance using both experiments and calculations. PIV measurements have been performed at different hub to shroud planes inside one diffuser channel passage for a given speed of rotation and various flow rates. For each operating condition, the PIV measurements have been trigged with different angular impeller positions. The performances and the static pressure rise of the diffuser were also measured using a three-hole probe. The numerical simulations were carried out with Star CCM+ 9.06 code (RANS frozen and unsteady calculations). Some results were already presented at the XXth IAHR Symposium for three flowrates for RANS frozen and URANS calculations. In the present paper, comparisons between URANS calculations with and without leakages and experimental results are presented and discussed for these flow rates. The performances of the diffuser obtained by numerical calculations are compared to those obtained by the three-holes probe measurements. The comparisons show the influence of fluid leakages on global performances and a real improvement concerning the efficiency of the diffuser, the pump and the velocity distributions. These results show that leakage is an important parameter that has to be taken into account in order to make improved comparisons between numerical approaches and experiments in such a specific model set up.

Structure Determination of Macrolactin Compounds with Antibacterial Activities Isolated from Bacillus polyfermenticus KJS-2 (Bacillus polyfermenticus KJS-2에서 분리된 항생물질 마크로락틴류의 구조결정)

  • Kim, Dong-Hee;Kang, Kyung-Ran;Kim, Hyun-Woo;Yoon, Si-Yeol;Kim, Chun-Gyu;Yamaguchi, Tokutaro;Sohng, Jae-Kyung;Kang, Jae-Seon
    • Journal of Life Science
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    • v.20 no.12
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    • pp.1792-1800
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    • 2010
  • In this study, we isolated five macrolactin compounds from a fermentation broth of Bacillus polyfermenticus KJS-2. The macrolactin compounds were structurally identified as macrolactin A (MA), 7-O-malonyl macrolactin A (MMA), 7-O-succinyl macrolactin A (SMA), macrolactin E (ME) and macrolactin F (MF) via a variety of NMR techniques, COZY, DEPT, HMQC and HMBC, and mass and specific rotation assays. The three macrolactin compounds, MA, MMA and SMA, profoundly inhibited the growth of both vancomycin-resistant Enterococci (VREs) and methicillin-resistant Staphylococcus aureus (MRSA), the inhibition of which were estimated via a disc agar diffusion bioassay. MA, MMA, and SMA exhibited antibacterial activities superior to those of vancomycin and teicoplanin.

The Study of Two-dimensional Chemical Distribution about Soil using Laser Spectroscopy (레이저 분광법을 활용한 토양 2차원 화학적 분포도 검출 연구)

  • Yang, Jun-Ho;Yoh, Jai-Ick
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.45 no.6
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    • pp.523-530
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    • 2017
  • Laser-Induced Breakdown Spectroscopy (LIBS) which a plasma is irradiated at a specific wavelength depending on the material when a high-energy laser is irradiated, and a Raman spectroscopy which measures rotation and vibration in molecules as light-scattering phenomenon occurs, are attracting attention as a space exploration technology because of the advantages of high accuracy and real-time analysis, and the ability to perform long-range detection. In this study, the tendency of the laser spectrum according to the change of the soil component was analyzed by laser spectroscopy and the two - dimensional chemical distribution was conducted based on the trend of laser spectrum. We have also established the environment of Mars (4-7 torr) and lunar atmosphere (<1 torr) in experimental setup, to prove that it is possible to measure by difference of soil chemical composition using LIBS and Raman spectroscopy even in artificial space environment.

Image Watermarking for Identification Forgery Prevention (신분증 위변조 방지를 위한 이미지 워터마킹)

  • Nah, Ji-Hah;Kim, Jong-Weon;Kim, Jae-Seok
    • The Journal of the Korea Contents Association
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    • v.11 no.12
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    • pp.552-559
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    • 2011
  • In this paper, a new image watermarking algorithm is proposed which can hide specific information of an ID card's owner in photo image for preventing ID's photo forgery. Proposed algorithm uses the image segmentation and the correlation peak position modulation of spread spectrum. The watermark embedded in photo ensures not only robustness against printing and scanning but also sufficient information capacity hiding unique number such as social security numbers in small-sized photo. Another advantage of proposed method is extracting accurate information with error tolerance within some rotation range by using $2^h{\times}2^w$ unit sample space not instead $1{\times}1$ pixels for insertion and extraction of information. 40 bits information can be embedded and extracted at $256{\times}256$ sized ID photo with BER value of 0 % when the test condition is 300dpi scanner and photo printer with 22 photos. In conclusion, proposed algorithm shows the robustness for noise and rotational errors occured during printing and scanning.

The Nutrition Requirements and Foraging Behaviour of Ostriches

  • Miao, Z.H.;Glatz, P.C.;Ru, Y.J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.16 no.5
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    • pp.773-788
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    • 2003
  • Ostrich farming is a developing industry in most countries in the world, with farm profitability being largely dependent on the quality of the products, especially skins and meat. To produce quality products, it is essential to ensure that nutrient supply matches the nutrient requirements of ostriches during their growth. To achieve this, information on feed utilisation efficiency and nutrient requirements of ostriches at different maturity stages is required. In South Africa, a number of experiments were carried out to assess the nutritive value of feed and to define the nutrient requirement of ostriches. These data were derived from limited number of birds and the direct application of the results to ostrich farming in Australia and other countries is questionable due to the difference in environment and feed resources. Initially ostrich farmers used data from poultry as a guideline for feed formulation, but in recent years more data has become available for ostriches. Ostriches have a better feed utilisation efficiency and a larger capacity of using high fibre feeds such as pastures than poultry. This review revealed that there are a number of areas there further nutritional research and development is required to ensure the ostriches are provided suitable diets to maximise farm profitability. These include the assessment of the nutritive value of feed ingredients for ostrich chicks and adult birds, the determination of nutrient requirements of ostriches under different farming systems, the development of ostrich diet for producing specific product, and grazing management strategies of ostriches in a crop-pasture rotation system.

The Study on Goods Attributes and Brand Attitude by Fashion Brand (패션브랜드에 따른 상품속성과 브랜드 태도에 관한 연구)

  • Shin, Won-Hye;Yoo, Tai-Soon
    • Korean Journal of Human Ecology
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    • v.13 no.6
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    • pp.943-957
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    • 2004
  • The purpose of this study is to 1) understand the importance of brands, which are known as one of the key purchasing points to consumers today; 2) 10 clearly clarify the various attributes of goods well-known to consumers; 3) to research the effect of the goods attributes on brand attitude. We examined 465 consumers to understand a purchase or a shopping habit with national and non-brand. The study used SPSS 11.0 package for a data analysis. Then using varimax rotation, we employed a factor analysis to analyze the data and obtain Cronbach ${\alpha}$ value. For more specific data analysis, we conducted t-test, regression analysis, and x2 analysis. The results are as followings: 1. The goods attribute is classified into product attribute, shop attribute, and price attribute. The product attribute is divided into wearability, labeling of size and quality, aesthetic expression, brand expression-harmony, textile-suitability, manageability and product assortment. The shop attribute is into shop environment, shopping convenience, promotion, salesperson service, convenience of location, shop's reputation. The price attribute is into price reasonability, price value, price economy, and price information. 2. The product attribute is different, by national and non-brands, in wearability, labeling of size and quality, brand expression-harmony, textile-suitability, manageability. The shop attribute had a significant difference in environment of shop and its reputation, and the price attribute had one only in price economy. 3. The brand attitude was affected by wearability, aesthetic expression, shop environment, price value, and price information. 4. Also, there exists a difference by demographic variables(age, job, academic background, marriage, income level) in brand attitude. For example, national brands have its consumers with the following variables: higher education, higher income, professional job, over 20s, and married.

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Development and validation of a computational multibody model of the elbow joint

  • Rahman, Munsur;Cil, Akin;Johnson, Michael;Lu, Yunkai;Guess, Trent M.
    • Advances in biomechanics and applications
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    • v.1 no.3
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    • pp.169-185
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    • 2014
  • Computational multibody models of the elbow can provide a versatile tool to study joint mechanics, cartilage loading, ligament function and the effects of joint trauma and orthopaedic repair. An efficiently developed computational model can assist surgeons and other investigators in the design and evaluation of treatments for elbow injuries, and contribute to improvements in patient care. The purpose of this study was to develop an anatomically correct elbow joint model and validate the model against experimental data. The elbow model was constrained by multiple bundles of non-linear ligaments, three-dimensional deformable contacts between articulating geometries, and applied external loads. The developed anatomical computational models of the joint can then be incorporated into neuro-musculoskeletal models within a multibody framework. In the approach presented here, volume images of two cadaver elbows were generated by computed tomography (CT) and one elbow by magnetic resonance imaging (MRI) to construct the three-dimensional bone geometries for the model. The ligaments and triceps tendon were represented with non-linear spring-damper elements as a function of stiffness, ligament length and ligament zero-load length. Articular cartilage was represented as uniform thickness solids that allowed prediction of compliant contact forces. As a final step, the subject specific model was validated by comparing predicted kinematics and triceps tendon forces to experimentally obtained data of the identically loaded cadaver elbow. The maximum root mean square (RMS) error between the predicted and measured kinematics during the complete testing cycle was 4.9 mm medial-lateral translational of the radius relative to the humerus (for Specimen 2 in this study) and 5.30 internal-external rotation of the radius relative to the humerus (for Specimen 3 in this study). The maximum RMS error for triceps tendon force was 7.6 N (for Specimen 3).

Optimal Operating Condition of Vortex Separator for Combined Sewer Overflows Treatment (합류식 하수관거 월류수 처리를 위한 와류형 분리장치의 최적 운전조건)

  • Han, Jung-kyun;Joo, Jae-young;Lee, Bum-joon;Na, Ji-hun;Park, Chul-hwi
    • Journal of Korean Society of Water and Wastewater
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    • v.23 no.5
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    • pp.557-564
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    • 2009
  • A combined sewer system can quickly drain both storm water and sewage, improve the living environment and resolve flood measures. A combined sewer system is much superior to separate sewer system in reduction of the non-point source pollutant load. However, during rainfall. it is impossible in time, space and economic terms to cope with the entire volume of storm water. A sewage system that exceeds the capacity of the sewer facilities drain into the river mixed with storm-water. In addition, high concentration of CSOs by first-flush increase pollution load and reduce treatment efficiency in sewage treatment plant. The aim of this study was to develope a processing unit for the removal of high CSOs concentrations in relation to water quality during rainfall events in a combined sewer. The most suitable operational design for processing facilities under various conditions was also determined. With a designed discharge of 19.89 m/min, the removal efficiency was good, without excessive overflow, but it was less effective in relation to underflow, and decreased with decreasing particle size and specific gravity. It was necessary to lessen radius of vortex separator for increasing inlet velocity in optimum range for efficient performance, and removal efficiency was considered to high because of rotation increases through enlargement of comparing height of vortex separator in diameter. By distribution of influent particle size, the actual turbulent flow and experimental results was a little different from the theoretical removal efficiency due to turbulent effect in device.

Study on the Influence and Difference of Taijiquan and Five-animal Exercises on College Students' Ankle Muscle Strength

  • Nie, ShangQi;Ma, Biao;Song, Jeho
    • International Journal of Advanced Culture Technology
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    • v.8 no.3
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    • pp.307-315
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    • 2020
  • The physique and health status of Chinese college students have received a generous concern in recent years. The physical condition of Chinese college students is not good and this phenomenon is especially obvious among female college students, which has been an disputable fact. This study starts from exercise intervention to study the concrete influence of taijiquan (a kind of traditional Chinese shadow boxing) and five-animal exercises on human body balance ability; the study uses experimental apparatus to measure the specific impact of exercise intervention on human body balance ability; meanwhile, the study also applies data analysis to longitudinally study whether the two studied sports items affect body balance, and whether there is difference in terms of the influence of two sports items on human body balance ability. The conclusions are as follows: firstly, 24-style taijiquan and five-animal exercises can improve ankle muscle strength, and the focus and degree of the improvement are different; secondly, five-animal exercises have a better improvement effect on the flexor and extensor muscles of ankle joint and 24-style taijiquan is in the second place. Moreover, compared with 24-style taijiquan, there is no significant difference in terms of the improvement caused by five-animal exercises; thirdly, 24-style taijiquan has a better effect on the improvement of internal rotation and evertors muscle strength. Compared with 24-style taijiquan, five-animal exercises have no significant difference in terms of the improvement degree.