• 제목/요약/키워드: Progressive reduction

검색결과 153건 처리시간 0.022초

Brain morphology according to age, sex, and handedness

  • Kang, Sa Jin;Kang, Kyeong A;Jang, Han;Lee, Jae Youn;Lee, Kang Il;Kwoen, Min Seok;Kim, Jung Soo;Park, Kang Min
    • Annals of Clinical Neurophysiology
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    • 제19권2호
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    • pp.93-100
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    • 2017
  • In this article, we review the differences of the brain morphology according to age, sex, and handedness. Age is a well-known factor affecting brain morphology. With aging, progressive reduction of brain volume is driven. Sex also has great effects on brain morphology. Although there are some reports that the differences of brain morphology may originate from the differences of weight between the 2 sexes, studies have demonstrated that there are regional differences even after the correction for weight. Handedness has long been regarded as a behavioral marker of functional asymmetry. Although there have been debates about the effect of handedness on brain morphology, previous well-established studies suggest there are differences in some regions according to handedness. Even with the studies done so far, normal brain morphology is not fully understood. Therefore, studies specific for the each ethnic group and standardized methods are needed to establish a more reliable database of healthy subjects' brain morphology.

Vibration analysis of sandwich sectorial plates considering FG wavy CNT-reinforced face sheets

  • Tahouneh, Vahid
    • Steel and Composite Structures
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    • 제28권5호
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    • pp.541-557
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    • 2018
  • This paper presents the influence of carbon nanotubes (CNTs) waviness and aspect ratio on the vibrational behavior of functionally graded nanocomposite sandwich annular sector plates resting on two-parameter elastic foundations. The carbon nanotube-reinforced (CNTR) sandwich plate has smooth variation of CNT fraction along the thickness direction. The distributions of CNTs are considered functionally graded (FG) or uniform along the thickness and their mechanical properties are estimated by an extended rule of mixture. In this study, the classical theory concerning the mechanical efficiency of a matrix embedding finite length fibers has been modified by introducing the tube-to-tube random contact, which explicitly accounts for the progressive reduction of the tubes' effective aspect ratio as the filler content increases. Effects of CNT distribution, volume fraction, aspect ratio and waviness, and also effects of Pasternak's elastic foundation coefficients, sandwich plate thickness, face sheets thickness and plate aspect ratio are investigated on the free vibration of the sandwich plates with wavy CNT-reinforced face sheets. The study is carried out based on three-dimensional theory of elasticity and in contrary to two-dimensional theories, such as classical, the first- and the higher-order shear deformation plate theories, this approach does not neglect transverse normal deformations. The sandwich annular sector plate is assumed to be simply supported in the radial edges while any arbitrary boundary conditions are applied to the other two circular edges including simply supported, clamped and free.

한국여성의 Vitamin D 상태 및 관련 생화학적 변인에 관한 연구 (Vitamin D Status and Related Biochemical Parameters of Women in Korean)

  • 문수재
    • Journal of Nutrition and Health
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    • 제29권7호
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    • pp.758-771
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    • 1996
  • This study attempted to define reference data for the distribution of vitamin d status and to explore the relationship between vitamin D status and related biochemical indices in Korean women. The vitamin D status of 179 Korean women aged from 20 to 75 years was analyzed by using HPLC(High Pressure Liquid Chromatography). Related biochemical indices such as iPTH, alkaline phosphatase, creatinine, albumin, Ca, Mg and P were also measured. The mean serum level of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D were s25.8ng/ml and 89.8pg/ml, respectively. Low 25-hydroxyvitamin D (<25nmol/L) was found in 29 subjects(16.5%). There was a significantly progressive decrease in serum 25-hydroxyvitamin D with increasing age(p<0.05). After in their, there was a dramatical reduction in 25-hydroxyvitamin D(p<0.05). It was also significant in post-menopasusal women compared with pre-menopausal women(p<0.000). Serum alkaline phosphatase levels increased significantly with age(p<0.001). Whereas serum calcium and phosphorus levels remained constant with age. Serum 250-hydroxyvitamin D was invesely related to iPTH (p<0.05) and alkaline phophatase (p<0.001).

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Topological optimization procedure considering nonlinear material behavior for reinforced concrete designs

  • Franca, Marcela Bruna Braga;Greco, Marcelo;Lanes, Ricardo Morais;Almeida, Valerio Silva
    • Computers and Concrete
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    • 제17권1호
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    • pp.141-156
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    • 2016
  • The search for new structural systems capable of associating performance and safety requires deeper knowledge regarding the mechanical behavior of structures subject to different loading conditions. The Strut-and-Tie Model is commonly used to structurally designing some reinforced concrete elements and for the regions where geometrical modifications and stress concentrations are observed, called "regions D". This method allows a better structural behavior representation for strength mechanisms in the concrete structures. Nonetheless, the topological model choice depends on the designer's experience regarding compatibility between internal flux of loads, geometry and boundary/initial conditions. Thus, there is some difficulty in its applications, once the model conception presents some uncertainty. In this context, the present work aims to apply the Strut-and-Tie Model to nonlinear structural elements together with a topological optimization method. The topological optimization method adopted considers the progressive stiffness reduction of finite elements with low stress values. The analyses performed could help the structural designer to better understand structural conceptions, guaranteeing the safety and the reliability in the solution of complex problems involving structural concrete.

Combination of air stripping and biological processes for landfill leachate treatment

  • Smaoui, Yosr;Bouzid, Jalel;Sayadi, Sami
    • Environmental Engineering Research
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    • 제25권1호
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    • pp.80-87
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    • 2020
  • Landfill waste decomposition generates a dark effluent named, leachate which is characterized by high organic matter content. To minimize these polluting effects, it becomes necessary to develop an effective landfill leachate treatment process. The objective of this study was to evaluate the performance of an innovative approach based on air stripping, anaerobic digestion (AD) and aerobic activated sludge treatment. A reduction of 80% of ammonia and an increase of carbon to nitrogen ratio to 25 were obtained, which is a suitable ratio for AD. This latter AD was performed in fixed bed reactor with progressive loading rate that reached 2 and 3.2 g COD/L/d for the raw and diluted leachate (1:2), respectively. The anaerobic treatment led to significant removal of chemical oxygen demand (COD) and biogas production, especially for the diluted leachate. The COD removal was of 78% for the raw leachate and a biogas production of 4 L/d with 70% methane content. The use of the diluted leachate led to 81% of COD removal and 7 L/d biogas with 75% methane content. It allowed a removal of 77% COD and more than 97% of the organic compounds present in the initial leachate sample.

측두하악관절에 발생된 골성 강직 (Bony ankylosis of temporomandibular joint)

  • 이병도;윤영남;엄기두;나종일;이완
    • Imaging Science in Dentistry
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    • 제32권2호
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    • pp.113-118
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    • 2002
  • Ankylosis of joint is defined as limited movement due to infection, trauma, or surgical procedure. A 59-year-old female with a chief complaint of limited movements during mouth opening had a positive history of trauma to her right TMJ area about 5 years ago. From that time, progressive mouth opening limitation and intermittent pain have occurred. At the time of admission the patient showed mandibular deviation to the right side during mouth opening, with a maximum opening limited to 5 mm. On plain radiographs, right condylar enlargement and joint space reduction by newly formed bony tissues were observed. CT scans showed right condylar enlargement, cortical sclerosis, and thickening of the condyle, articular fossa and articular eminence.

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Study on drilling of CFRP/Ti6Al4V stack with modified twist drills using acoustic emission technique

  • Prabukarthi, A.;Senthilkumar, M.;Krishnaraj, V.
    • Steel and Composite Structures
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    • 제21권3호
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    • pp.573-588
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    • 2016
  • Carbon Fiber Reinforced Plastic (CFRP) and Titanium Alloy (Ti6Al4V) stack, extensively used in aerospace structural components are assembled by fasteners and the holes are made using drilling process. Drilling of stack in one shot is a complicated process due to dissimilarity in the material properties. It is vital to have optimal machining condition and tool geometry for better hole quality and tool life. In this study the tool wear and hole quality were analysed by experimental analysis using three modified twist drills and online tool condition monitoring using Acoustics Emission (AE) sensor. Helix angle and point angle influence tool performance and cutting force. It was found that a tool geometry (TG1) with high helix angle of $35^{\circ}$ with low point angle $130^{\circ}$ results in reduction in thrust force of 150-500 N range but the TG2 also perform almost similar to TG1, but when compared with the AErms voltage generated during drilling it was found that progressive rise in voltage in TG1 is less with respect to TG2 which can be attributed to tool life. In process wear monitoring was done using crest factor as monitoring index. AErms voltage were measured and correlated with the performance of the drills.

Skeletal Manifestations of Mucolipidosis II/III

  • Cho, Sung Yoon
    • Journal of mucopolysaccharidosis and rare diseases
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    • 제2권1호
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    • pp.8-12
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    • 2016
  • Mucolipidosis (ML) is a kind of skeletal dysplasia. Characteristic X-ray findings of the bone may contribute to the early diagnosis and treatment of ML II/III. Skeletal radiographs show distinctive patterns at different ages: neonatal hyperparathyroidism, osteodystrophy (similar to chronic osteitis fibrosa cystica), and dysostosis multiplex. Patients with ML II/III show a mixture of osteodystrophic bone changes and atypical changes of dysostosis multiplex: proximal pointing of the metacarpals in the wrist, dysplastic changes in the lower third of the ilia, marked broadening of the ribs becoming oar-shaped, and beaking of the lower thoracic and lumbar vertebrae. In ML II, the osteodystrophy has clinical and radiographic features of neonatal hyperparathyroidism. In some neonatal subjects, chemical hyperparathyroidism is also demonstrated. After transient hyperparathyroidism in newborns, the progressive osteitis fibrosa cystica develops from 3-6 months of age. Patients with ML III show prominent skeletal involvement, particularly the destruction of vertebral bodies and the femoral heads. Intravenous pamidronate treatment is well tolerated, and it can produce clinical effects, with a reduction in bone pain and improvements in mobility in patients with ML III. In this review, the skeletal manifestations of ML II and III are investigated.

Effect of Neem (Azadirachta indica) oil on the progressive growth of a spontaneous T cell lymphoma

  • Mallick, Sanjaya Kumar;Gupta, Vivekanand;Singh, Mahendra Pal;Vishvakarma, Naveen Kumar;Singh, Nisha;Singh, Sukh Mahendra
    • Advances in Traditional Medicine
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    • 제7권5호
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    • pp.459-465
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    • 2008
  • The present study was undertaken to investigate the effect of in vivo administration of neem oil intra-peritoneally (i.p.) to mice bearing a progressively growing transplantable T cell lymphoma of spontaneous origin, designated as Daltons lymphoma (DL), on the tumor growth. Mice were administered various doses of neem oil mixed in groundnut oil, which was used as a diluting vehicle or for administration to control DL-bearing mice. Administration of neem oil resulted in an acceleration of tumor growth along with a reduction in the survival time of the tumor-bearing host. Neem oil administered DL-bearing mice showed an augmented apoptosis in splenocytes, bone marrow cells and thymocytes along with an inhibition in the anti-tumor functions of tumor-associated macrophages. Thus this study gives an altogether a novel information that neem oil instead of the popular belief of being anti-tumor and immunoaugmentary may in some tumor-bearing conditions, behave in an opposite way leading to an accelarated tumor progression along with a collapse of the host's anti-tumor machinery. These observations will thus have long lasting clinical significance, suggesting caution in use of neem oil for treatment of cancer.

속성 가중치에 대한 서수 정보가 주어질 때 다요소 의사결정 방법의 비교분석에 관한 연구 (Comparative Analysis of Multiattribute Decision Aids with Ordinal Preferences on Attribute Weights)

  • 안병석
    • 한국경영과학회지
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    • 제30권1호
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    • pp.161-176
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    • 2005
  • In a situation that ordinal preferences on multiattribute weights are captured, we present two solution approaches: an exact approach and an approximate method. The former, an exact solution approach via interaction with a decision-maker, pursues the progressive reduction of a set of non-dominated alternatives by narrowing down the feasible attribute weights region. Subsequent interactive questions and responses, however, sometimes may not guarantee the best alternative or a complete rank order of a set of alternatives that the decision-maker desires to have. Approximate solution approaches, on the other hand, can be divided into three categories including surrogate weights methods, dominance value-based decision rules, and three classical decision rules. Their efficacies are evaluated in terms of choice accuracy via a simulation analysis. The simulation results indicate that a proposed hybrid approach, intended to combine an exact solution approach through interaction and a dominance value-based approach, is recommendable for aiding a decision making in a case that a final choice is seldom made at single step under attribute weights that are imprecisely specified beyond ordinal descriptions.