• Advances in nano research
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• v.12 no.6
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• pp.567-581
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• 2022

The free and forced vibration in addition to electric energy harvesting of a piezoelectric disk resting on two-parameter foundation modeled by modified couple stress as well as Kirchhoff plate theory is probed. The governing equations and boundary conditions are obtained using Hamilton's principle. Then, the free and forced vibration are solved using numerical solutions, generalized differential quadrature method (GDQM) and Newmark-beta method. The forced vibration is resulted from a base excitation load. Also, the possible voltage which can be harvested from this system is obtained using generalized integral quadrature method. The validity of the formulation and solution procedure is confirmed using a compassion study. The impact of parameters such as length effect, inner to outer radius ratio, and foundations parameters on the free and forced vibration as well as energy harvesting is investigated in detail. This paper can be a basis for future studies in the area of piezoelectric harvesters in small scales.

• Advances in nano research
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• v.16 no.3
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• pp.313-324
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• 2024

The main aims of this study are to develop a new nonlocal quasi-3D theory for the free vibration behaviors of the functionally graded sandwich nanobeams. The sandwich beams consist of a ceramic core and two functionally graded material layers resting on elastic foundations. The two layers, linear spring stiffness and shear layer, are used to model the effects of the elastic foundations. The size-effect is considered using nonlocal elasticity theory. The governing equations of the motion of the functionally graded sandwich nanobeams are obtained via Hamilton's principle in combination with nonlocal elasticity theory. Then the Navier's solution technique is used to solve the governing equations of the motion to achieve the nonlocal free vibration behaviors of the nanobeams. A deep parametric study is also provided to demonstrate the effects of some parameters, such as length-to-height ratio, power-law index, nonlocal parameter, and two parameters of the elastic foundation, on the free vibration behaviors of the functionally graded sandwich nanobeams.

• Steel and Composite Structures
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• v.52 no.4
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• pp.487-499
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• 2024

The primary objective of this study is to analyze the free vibration behavior of a sandwich cylindrical shell with a defective core and wavy carbon nanotube (CNT)-enhanced face sheets, utilizing the three-dimensional theory of elasticity. The intricate equations of motion for the structure are solved semi-analytically using the generalized differential quadrature method. The shell structure consists of a damaged isotropic core and two external face sheets. The distributions of CNTs are either functionally graded (FG) or uniform across the thickness, with their mechanical properties determined through an extended rule of mixture. In this research, the conventional theory regarding the mechanical effectiveness of a matrix embedding finite-length fibers has been enhanced by introducing tube-to-tube random contact. This enhancement explicitly addresses the progressive reduction in the tubes' effective aspect ratio as the filler content increases. The study investigates the influence of a damaged matrix, CNT distribution, volume fraction, aspect ratio, and waviness on the free vibration characteristics of the sandwich cylindrical shell with wavy CNT-reinforced face sheets. Unlike two-dimensional theories such as classical and the first shear deformation plate theories, this inquiry is grounded in the three-dimensional theory of elasticity, which comprehensively accounts for transverse normal deformations.

• Archives of Reconstructive Microsurgery
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• v.7 no.1
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• pp.68-72
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• 1998

With the advent of microvascular free-tissue transfer, this single stage resurfacing method for large scar and soft tissue defects around the wrist in the patients of electrical burn has distinctive advantage over the conventional multistage pedicle-flap transfer. Between 1992 and 1996, we treated 9 cases of 8 patients who had large scar around the wrist due to old electrical burn with free flaps as a preparation of staged tendon graft. Mean age was 30.3 years and average scar area was $6{\times}11cm$. The length of time the injury and free flaps was 9 months on an average. Prior to the free flap, we performed the angiography to all patients in order to evaluate the circulation of the forearm and hand and to choose the recipient vessel. In all cases, proximal ulnar arteries in the forearm remained intact and all radial arteries remained intact in 8 of 9 cases on angiogram. The interosseous arteries were well visualized in all cases. We used the ulnar arteries as a recipient artery. The types of flaps used were f scapular cutaneous flaps, 2 dorsalis pedis flaps and a radial forearm flap. Flap survial was 100 percents with satisfactory functional and cosmetic results. Free flaps using ulnar artery as a recipient artery is one of the useful reconstruction methods for the resurfacing of large scar around the wrist in the patients of old electrical burn.

• Archives of Plastic Surgery
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• v.34 no.5
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• pp.569-573
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• 2007

Purpose: The selection of the recipient vessels in breast reconstruction has a great influence on the surgical result and the shape of the reconstructed breast. We would like to introduce the criteria for the selection of recipient vessels in delayed reconstruction of the breast. Methods: We studied 56 patients with delayed breast reconstruction using free TRAM flaps from April 1994 to December 2006. The thoracodorsal and the ipsilateral internal mammary vessels were used as recipients in 25 patients each, the opposite internal mammary vessels in 3 patients, the thoracoacromial vessels in 2 patients, and the transverse cervical artery with the cephalic vein in 1 patient. The survival rate of the flaps, the vessel diameter, the length of the pedicles, and the convenience of vessel dissection were studied. Results: The diameter of the recipient vessel did not influence the anastomosis. The operation time, the survival rate of flap, the postoperative complications showed no significant difference according to the recipient vessel. Dissection of the thoracodorsal vessels was tedious due to scar formation from the prior operation. Dissection of the internal mammary vessels proved to be relatively easy, and the required length of the pedicle was shorter than any other site, but the need for removal of rib cartilage makes this procedure inconvenient. Conclusion: The first choice of the recipient vessel in immediate breast reconstruction is the thoracodorsal vessels, but in cases of delayed reconstruction the internal mammary vessels are favored as the first choice, because the thoracodorsal vessels have a high unusability rate. If the ipsilateral internal mammary vessels prove to be useless, the contralateral vessels can be used. The thoracoacromial vessels are useful, when the mastectomy scar is located in the upper portion. The transverse cervical artery and the cephalic vein can serve as the last resort, if all other vessels are unreliable.

• Korean journal of food and cookery science
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• v.1 no.1
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• pp.8-17
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• 1985

Followings are the obtained results from the experiment of changes in content of proximate composition, free amino acid and nucleotides in soup prepared from beef brisket, leg bone, tripe and small intestine according to the diverse heating times-3, 6, 12, 18, 24, 30 hrs. The content of moisture in each sample is decreased from 97∼99％ in 8 hours heating to 95∼97% after heating 30 hours. On the contrary, the content of crude protein and crude fat are gradually increased in proportion to the length of heating times and it showed a rapid increasement when it was boiled 6∼12 hours long. We can extract the most protein from the soup stock of tripe among all samples ana the most crude fat from the leg bone. The contents of free amino acids is gradually increased in proportion to the length of heating times. Especially after being boiled longer than 18 hours it is increased obviously. In the soup stock prepared from the brisket, the lysine and alanine were contained the most. In leg bone soup stock, glutamic acid and histidine were extracted the most but bone soup stock, glutamic acid contents were decreased a little in longer heating. In the soup stock of tripe, glutamic acid which is contained very little in a raw material was extracted more as increasing times. In the soup stock of small intestine, lysine and glutamic acid were extracted the most. The least content in free amino acid from each sample was cystine which is sulphur-containing amino acid. These result suggest that, in order to get enough extraction of amino acid, crude fat, 18 hours heating is the most useful while 5’-IMP, which is the taste compound of meat, is extracted at 3 hours heating.

• Archives of Reconstructive Microsurgery
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• v.5 no.1
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• pp.106-111
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• 1996

Purpose : Propose a surgical technique in donor harvesting method in free vascularized proximal fibular epiphysis. Methodology : Concerned about growth potentials of the transplanted epiphysis in our long term results of the epiphyseal transplanted 13 cases more than 4 years follow-up, anterior tibial artery which contains anterior tibial recurrent artery is most reliable vessel to proximal fibular epiphysis which is the best donor of the free vascularized epiphyseal transplantation. In vascular anatomical aspect proximal fibular epiphysis norished by latearl inferior genicular artery from popliteal, posterior tibial recurrent artery and anterior tibial recurrent artery from anterior tibial artery and peroneal artery through metaphysis. The lateral inferior genicular artery is very small and difficult to isolate, peroneal artery from metaphysis through epiphyseal plate can not give enough blood supply to epiphysis itself. The anterior tibial artery which include anterior tibial recurrent and posterior tibial recurrent artery is the best choice in this procedure. But anterior tibial recurrent artery merge from within one inch from bifucating point of the anterior and posterior tibial arteries from popliteal artery. So it is very difficult to get enough vascular pedicle length to anastomose in recipient vessel without vein graft even harvested from bifucating point from popliteal artery. Authors took recipient artery from distal direction of anterior tibial artery after ligation of the proximal popliteal side vessel, which can get unlimited pedicle length and safer dissection of the harvesting proximal fibular epiphysis. Results : This harvesting procedure can performed supine position, direct anterolateral approach to proximal tibiofibular joint. Dissect and isolate the biceps muscle insertion from fibular head, micro-dissection is needed to identify the anterior tibial recurrent arteries to proximal epiphysis, soft tissue release down to distal and deeper plane to find main anterior tibial artery which overlying on interosseous membrane. Special care is needed to protect peroneal nerve damage which across the surgical field. Conclusions : Proximal fibular epiphyseal transplantation with distally directed anterior tibial artery harvesting technique is effective and easier dissect and versatile application with much longer arterial pedicle.

• Journal of Nutrition and Health
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• v.27 no.5
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• pp.473-482
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• 1994

This study was to compare the bioavailability of calcium from anchovy and tofu to those of calcium from calcium carbonate(CaCO3)as the control diet and non-fat dry milk(NFDM). Rats weighing 50-60g were placed on experimental diets and deionized water at free access for 4 weeks. Diets contained 0.2% calcium from calcium-carbonate, NFDM, anchovy, tofu or 0.5% calcium as obtained were as follows : 1) No significant differences in the apparent absorption of calcium(62.5%-71.0%) were observed in the rats fed four different calcium sources at the level of 0.2% while 0.5% calcium diet group apparently absorbed calcium less efficiently(52.2%). 2) Bone length of tibia and femur was not significantly different among the groups, though 0.5% calcium of control group showed slightly longer length. 3) Tibia fat-free dry weights of 0.2% calcium of NFDM and anchovy diet groups were not significantly different from that of 0.5% calcium of control group. For femurs NFDM, anchovy and tofu groups were similar in their fat-free dry weight to that of 0.5% calcium group. 4) For calcium contents tibia contents tibia from anchovy treated group showed higher value than calcium-carbonate and tofu groups and the value was not significantly different from that of 0.5% calcium group. In femur NFDM, tofu and calcium-carbonate groups were not significantly different in their calcium content but 0.5% calcium group had higher level of calcium than 0.2% calcium groups. 5) The normalized values(NV) show that there was no significant differences in NV among 0.2% CaCO3 anchovy and tofu groups, while NV of NFDM group was significantly lower than that of calcium-carbonate group. NV of 0.5% calcium group was a little more than 50% of those in 0.2% calcium groups. Though the values obtained for the calcium bioavailability were somewhat variable among experimental products, it was demonstrated that anchovy and tofu are as good as NFDM for the dietary calcium provider when calcium intake is at marginal level.

• Smart Structures and Systems
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• v.8 no.1
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• pp.17-37
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• 2011

The microcantilever (MCL) sensor is one of the most promising platforms for next-generation label-free biosensing applications. It outperforms conventional label-free detection methods in terms of portability and parallelization. In this paper, an overview of recent advances in our understanding of the coupling between biomolecular interactions and MCL responses is given. A dual compact optical MCL sensing platform was built to enable biosensing experiments both in gas-phase environments and in solutions. The thermal bimorph effect was found to be an effective nanomanipulator for the MCL platform calibration. The study of the alkanethiol self-assembly monolayer (SAM) chain length effect revealed that 1-octanethiol ($C_8H_{17}SH$) induced a larger deflection than that from 1-dodecanethiol ($C_{12}H_{25}SH$) in solutions. Using the clinically relevant biomarker C-reactive protein (CRP), we revealed that the analytical sensitivity of the MCL reached a diagnostic level of $1{\sim}500{\mu}g/ml$ within a 7% coefficient of variation. Using grazing incident x-ray diffractometer (GIXRD) analysis, we found that the gold surface was dominated by the (111) crystalline plane. Moreover, using X-ray photoelectron spectroscopy (XPS) analysis, we confirmed that the Au-S covalent bonds occurred in SAM adsorption whereas CRP molecular bindings occurred in protein analysis. First principles density functional theory (DFT) simulations were also used to examine biomolecular adsorption mechanisms. Multiscale modeling was then developed to connect the interactions at the molecular level with the MCL mechanical response. The alkanethiol SAM chain length effect in air was successfully predicted using the multiscale scheme.

• Journal of Nutrition and Health
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• v.31 no.6
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• pp.1057-1065
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• 1998

Anthropometric and body compositional changes and the outcomes of the pregnancies of 90 healthy Korean women were investigated in a longitudinal study. Their weight increased from 51.3$\pm$5.9kg to 65.1$\pm$7.8kg during their pregnancies. The total weight gain was 13.8$\pm$4.5kg, and therefore, weekly weight gain was 340$\pm$110g during the entire period of the pregnancy. The weight gain was composed of approximately 50-60% fat mass and 40-50% fat-free mass. Skinfold thicknesses, both of triceps and subscapular, increased during the pregnancies. The fat mass calculated from skinfold thickness and that measured with bioelectrical impedance analysis went on increasing during the pregnancies. Although there was a considerable difference with respect to the fat mass observed using the three methods, fat mass gain was 5.0-6.1kg and fat-free mass gain was 4.0-5.3kg from the first trimester to the third trimester of pregnancies. There were significant correlations between maternal anthropometric parameters and indices of pregnancy outcomes. Especially, the infant's birth weight was associated with maternal pre-pregnancy weight and weight gains during the pregnancies. The infant's birth length was related to the maternal weight observed at term(p<0.05) and weight gain during the entire pregnancies (p<0.05) . Neither increase of fat mass nor fat-free mass affected the outcomes of pregnancy. These results show that maternal weight gain during pregnancy is led by increments of approximately above 50% fat mass. The fat mass increase seems to be larger in central areas than in subcutaneous areas. Maternal weight gain during pregnancy, especially during late pregnancy, is a factor affecting the birth weight and length of infant. On the basis of the body compositional changes, it can be predicted that the additional energy requirement for pregnancy in Korean women is more than 200-230 MJ (64,500-76,250kca1). (Korean J Nutrition 31(6) : 1057-1065, 1998)