• Macromolecular Research
• /
• v.12 no.1
• /
• pp.119-126
• /
• 2004

In this study, the influence of silane coupling agents, featuring different organo-functional groups on the interlaminar and thermal properties of woven glass fabric-reinforced nylon 6 composites, has been by means of short-beam shear tests, dynamic mechanical analysis, scanning electron microscopy, and thermogravimetric analysis. The results indicate that the fiber-matrix interfacial characteristics obtained using the different analytical methods agree well with each other. The interlaminar shear strengths (ILSS) of glass fabric/nylon 6 composites sized with various silane coupling agents are significantly improved in comparison with that of the composite sized commercially. ILSS of the composites increases in the order: Z-6076 with chloropropyl groups in the silanes > Z-6030 with methacrylate groups> Z-6020 with diamine groups; this trend is similar to that of results found in an earlier study of interfacial shear strength. The dynamic mechanical properties, the fracture surface observations, and the thermal stability also support the interfacial results. The improvement of the interfacial properties may be ascribed to the different chemical reactivities of the reactive amino end groups of nylon 6 and the organo-functional groups located at the ends of the silane chains, which results from the increased chemical reactivity in order chloropropyl > methacrylate > diamine.

• Journal of the Korean Wood Science and Technology
• /
• v.25 no.3
• /
• pp.83-95
• /
• 1997

The degradation mode of lignocellulose by anaerobic ruminal cellulolytic bacterium Ruminococcus albus F-40 was investigated. Birchwood holocellulose and filter paper were incubated as the sole carbohydrate sources with using the Hungate techniques. After 2 or 4 days of incubation, samples were employed for chemical and electron microscopic evaluations. The degradation rate of cellulosic substrates and the adhesion rate of bacteria to the substrates increased proportionally with the decrease of relative crystallinity of cellulose, indicating the preferential breakdown of amorphous cellulose, by this bacterium. X-ray diffraction analyses and polarized light microscopy showed, however, that crystalline cellulose was also degraded by R. albus. FT-IR spectra indicated that not only cellulose but hemicellulose was also degraded by this bacterium. Electron microscopic investigations showed the protuberant structures on the surface of R. albus. These structures were much more significant when bacterial cells were grown in the media containing insoluble substrates, such as cellulose, indicating clearly that bacterial protuberant structures were induced by the substrates. Protuberant structures extended from the bacterial cells adhered tightly to the substrates and numerous vesicles covered the surface of cellulosic substrates affected. Cellulosome-like structures were distributed on the cellulose matrix. Electron microscopic works showed that diverse surface organells of R. albus were involved in the degradation of cellulosic materials. SEM examinations showed the breakdown of cellulose by R. albus was proceeded by severeal routes : short fiber formation, defibrillation and destrafication of cellulose microfibril.

• Journal of the Korean Society of Tobacco Science
• /
• v.32 no.2
• /
• pp.77-87
• /
• 2010

Traditional simultaneous distillation extraction(SDE) and solid-phase micro extraction(SPME) methods using GC/MS were compared for their effectiveness in the extraction of volatile flavor compounds from different tobacco leaves types(flue-cured, burley, oriental). The major volatile flavor compounds of flue-cured and burley tobacco were similar such as neophytadiene, solanone, megastigmatrienone isomers, ${\beta}$-damascenone and ${\beta}$-ionone. On the other hand, volatile flavor compounds such as norambreinolide, sclareolide were specifically identified in oriental tobacco. Each method was used to evaluate the responses of some analytes from real samples and standards in order to provide sensitivity comparisons between two techniques. Among three types of SPME fibers such as PDMS(Polydimethylsiloxane), PA(Polyacrylate) and PDMS/DVB (Polydimethylsiloxane/Divinylbenzene) which were investigated to determine the selectivity and adsorption efficiency, PDMS/DVB fiber was selected for the extractions of the volatile flavor compounds due to its effectiveness. The qualitative analysis showed that the total amount of volatile flavor compounds in SDE method(130 species) was much more than that in SPME method(85 species). SPME method was more efficient for all the highly volatile compounds than SDE method, but on the other hand, low-volatile compounds such as fatty acids or high-molecular hydrocabons were detected in SDE method. SPME method based on a short-time sampling can be adjusted to favor a selected group compounds in tobacco. Furthermore this results could be used to estimate the aroma characteristics of cigarette blending by using a different type of tobacco with more effectiveness and convenience.

• Journal of Veterinary Clinics
• /
• v.24 no.2
• /
• pp.244-246
• /
• 2007

Clinical and histopathologic features of idopathic polymyositis in twenty-month-old Alaskan malamute dog are described. The clinical signs were progressive exercise intolerance with acute exacerbation of weakness, muscle atrophy, synchronous pelvic limb gait, short stiff steps and tip-toeing as like walking on eggshells. Physical and clinical examination revealed no evidence of neurologic, skeletal and secondary muscular disorders associated with other diseases. Therefore muscle biopsy was performed at the most severe muscle atrophy lesions to confirm by histopathology. Histopathologic findings documented mononuclear cell infiltration and necrosis of muscle fiber and it was diagnosed as idiopathic polymyositis. Initial treatment was focused on pain relief. Prednisone at immunosuppressive dose (2 mg/kg) was administered orally twice daily. After 3 weeks of starting treatment, the patient showed improvement of gait, appetite, exercise as well as gradually return to normal state of hematologic and serum chemistry profiles.

• Journal of Fashion Business
• /
• v.13 no.3
• /
• pp.136-148
• /
• 2009

The phenomenon of the shrinkage of silk fibers induced by inorganic salts including LiBr, $Ca(NO_3){_2}$, and $CaCl_2$, has been studied up to the present as one of the finishing methods of silk. It is expected that the shrinkage phenomenon may greatly contribute to the realization of the high sensibility of silk fibers. Especially the shrinkage enables the expression of three-dimensional appearance of silk fabrics along with the improvements in dimensional stability, resilience in stretching, and comfort. Numerous theoretical studies on the contraction phenomenon by $Ca(NO_3){_2}$ have been conducted so far. These studies have focused mostly on the silk fibers. It is difficult to find studies on silk fabrics. The negative aspects of the finishing are such as strength drop, yellowish discoloration, and fiber damage. These should also be considered as well as the positive aspects. In this study, the phenomenon of salt shrinkage is diversely reviewed by applying $Ca(NO_3){_2}$ solution for the silk fabrics as objects. The changes in the air permeability, thickness, and color were investigated with focus on the shrinkage of the silk fabrics according to the changes in treatment conditions. Some findings from this study are as follows: Within short period of time at the initiation of salt shrinkage, the salt shrinkage proceeds effectively. In the case of concentration of 47.4%, or 46.3% of $Ca(NO_3){_2}$ solution, appropriate treatment time seems to be 20seconds, or $2{\sim}8$minutes, respectively. Excessive shrinkage is obtained when lower liquor ratio is adopted. As a result, the condition is acting extremely disadvantageously against the thickness and yellow discoloration aspects.

• Journal of Advanced Navigation Technology
• /
• v.10 no.3
• /
• pp.262-267
• /
• 2006

For growing need for the multimedia application in the vehicles, the MOST protocol has been focused on. The MOST protocol supports three kinds of communication modes; short control message, asynchronous packets, and reserved synchronous stream data. Because of a variety of transportation, the MOST is suitable for various applications in vehicle environment. In this paper, we implemented embedded system which is MOST-enabled AMS platform and tested the network communication operation through the control port and the synchronous channel of the source port. We implemented the prototype platforms which communicate each other on the MOST's POF network. Moreover we implemented the DivX decoder attached AMS platform and verified the operation by transferring the video stream and the control messages through the MOST network.

• Journal of Nutrition and Health
• /
• v.45 no.5
• /
• pp.462-469
• /
• 2012

We investigated dietary effects of prickly pear cactus (Opuntina ficus-indica) on plasma lipids, platelet aggregation (PA), hemolysis, plasma TBARS and liver enzymes. Twenty eight volunteer diving women in Jeju island had daily 20 g cactus tea containing 27% prickly pear cactus (PPC) powder for 4 weeks, and data for the study subjects were analyzed, on the basis of diagnostic criteria for blood pressure (BP)(${\geq}$ 140/90 mmHg), plasma cholesterol (${\geq}$ 200 mg/dL) and triglyceride (${\geq}$ 150 mg/dL). The subjects with higher BP had higher plasma total cholesterol (TC) and triglyceride (TG) concentrations than those with normal BP. Those with higher TC also had higher TG. Subjects with normal BP or normal TC had higher initial slope of PA than their higher counterpart in BP and TC. PPC intake decreased plasma TG in those with higher BP. PPC intake significantly decreased the elevated initial slope in groups with normal BP, TC, and TG. Hemolysis after PPC intake decreased significantly in all the subjects and plasma TBARS decreased in the subjects with higher plasma TC and higher TG. Glutamic-oxaloacetic transaminase (GOT) significantly increased and total bilirubin significantly decreased in all the subjects after PPC intake. The present study with diving women showed that beneficial effects of short term intake of prickly pear cactus might differ depending on the subject conditions in term of blood pressure, and plasma lipids. However, long term usage of prickly pear cactus may provide preventive effects of cardiovascular diseases to all the population, presumably by hypolipidemic, antithrombotic, and antioxidant actions of its bioactive flavonoids and soluble fiber.

• Journal of the Society of Naval Architects of Korea
• /
• v.54 no.4
• /
• pp.312-320
• /
• 2017

This paper deals with the development of structural test facility for the strength assessment of marine leisure boat built from carbon fiber reinforced plastics (CFRP) materials. The structural test facility consists of test jig, load application and control system, and data acquisition system. Test jig, and load application and control system are designed to accommodate various size and short span to depth ratios of single skin, top-hat stiffened and sandwich constructions in plated structural format such as square and rectangular shapes. A lateral pressure load, typical and important applied load condition to the plates of the hull structure for marine leisure boat, is simulated by employing a number of hydraulic cylinders operated automatically and manually. To examine and operate the structural test facility, five carbon/epoxy based FRP square plates having the test section area of $1m^2$, which are part of CFRP marine leisure boat hull, are prepared and they are subjected to monotonically increasing lateral pressure loads. In the test preparation, considering the symmetry of the plates geometry, various strain gauges and linear variable displacement transformer are used in conjunction with data acquisition system utilizing LabVIEW. From the test observation, the responses of the CFRP hull structure of marine leisure boat are understood by obtaining load to deflection and strain to load curves.

• Microbiology and Biotechnology Letters
• /
• v.49 no.2
• /
• pp.192-200
• /
• 2021

Kunun-zaki, produced by submerged fermentation of a combination of millet and sorghum, is a popular beverage in Northern Nigeria. Owing to the nature of the process involved in its production, kunun-zaki is highly susceptible to contamination by food spoilage microorganisms, leading to inconsistent quality and short shelf-life. In this study, we investigated various food spices, including cinnamon, garlic, and nutmeg, as potential preservatives that could be used to extend kunun-zaki shelf-life. Kunun-zaki varieties were fermented with each of these spices mentioned above and subjected to bacterial, nutritional, sensory, and quality maintenance assessments (using a twelve-member sensory panel to evaluate the organoleptic properties of kunun-zaki). Bacterial counts in the final products ranged between 10^5-7 CFU/ml. We identified two bacterial genera, Weissella and Enterococcus, based on partial 16S rRNA gene amplicon sequencing. Three amino acids, namely leucine, aspartate, and glutamate, were abundant in all kunun-zaki varieties, while the total essential amino acid content was above 39%, suggesting that kunun-zaki could potentially be considered as a protein-rich food source both for infants and adults. The kunun-zaki products were also rich in carbohydrates, crude proteins, ash, crude fiber, and fat, with contents estimated as 81-84, 8-11, 0.8-4.0, 2.9-3.58, and 5.1-6.3%, respectively. However, this nutritional content depreciated rapidly after 24 h of storage, except for kunun-zaki fermented with garlic, which its crude protein and fat content was maintained for up to 48 h. Our results revealed that organic spices increased the nutritional content of the kunun-zaki varieties and could be potentially be used as natural preservatives for enhancing the kunun-zaki shelf-life. However, garlic might be considered a better alternative based on our preliminary investigation. The presence of the isolated microorganisms in the analyzed kunun-zaki samples should be highlighted to raise awareness on the possible health hazards that could arise from poor handling and processing techniques.

• Nutrition Research and Practice
• /
• v.13 no.4
• /
• pp.333-343
• /
• 2019

BACKGROUND/OBJECTIVES: To compare five indices of adherence to the Mediterranean Diet (MD) among adults living in the Mediterranean region. SUBJECTS/METHODS: A total of 100 healthy Lebanese adults aged between 18 and 65 years. Face-to-face interviews to collect sociodemographic and medical information, to take anthropometric measurements, and to fill a validated, culturally adapted, food frequency questionnaire (FFQ). The score for each item was calculated following the recommendations for each corresponding index. The five MD indices were Mediterranean Diet Scale (MDScale), Mediterranean Food Pattern (MFP), MD Score (MDS), Short Mediterranean Diet Questionnaire (SMDQ), and the MedDiet score. RESULTS: Significant correlations were detected between items with P-values < 0.001. Minimal agreement was seen between MDScale and MedDiet score and maximal agreement between MDS and MedDiet score. Univariate and multivariate analyses showed that MDS and MedDiet scores had significant correlations with fiber and olive oil intake, main components of the MD. MDScale showed a significant correlation with waist-to-hip ratio and with total energy intake but none of the five indices was correlated to body mass index (BMI). CONCLUSIONS: The indices that showed the highest correlation with variables related to the MD are the MDScale and the MedDiet score; therefore, they can be used to assess our future study populations. Based on the current results, more than half of the study population was non-adherent to the MD and adherence to this diet did not appear to protect against being overweight ($BMI{\geq}30$).