Academic literature on the topic 'Anisotropic regulator'
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Journal articles on the topic "Anisotropic regulator"
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Abufanas, A. S., A. A. Lobaty, and Yu F. Yacina. "ANISOTROPIC REGULATOR OF DAMPING OF RANDOM VIBRATIONS OF THE MOBILE PLATFORM OF A BILAMENT VEHICLE APPARATUS." «System analysis and applied information science», no. 3 (November 2, 2017): 13–19. http://dx.doi.org/10.21122/2309-4923-2017-3-13-19.
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The problem of damping of random effects on a mobile platform with a system for monitoring the earth’s surface installed on an unmanned aerial vehicle is considered. As an external influence, we consider the random turbulence of the atmosphere, described with the aid of a shaping filter, to which white noise enters. Monitoring system with a mobile platform is considered as a control system, the criterion of optimality of which is proposed to use the criterion of quality of the stochastic norm of the system, which quantitatively characterizes the sensitivity of the output of the system to random input disturbances whose probabilistic distribution is not known accurately. This leads to a special variant of the stochastic norm-the anisotropic norm. A technique for constructing a robust phase control system using an anisotropic regulator is considered. The coefficients of the optimal regulator are obtained by mathematical modeling. As an example for evaluating the operability of the proposed algorithm, one of the control channels of the mobile platform, defined by a discrete mathematical model of the second order, is considered. Qualitative illustrations of the operability of the proposed algorithm and quantitative characteristics of the change in output signals are presented. The use of anisotropic regulators in damping systems of random effects is promising, since it allows to reduce the influence on the quality of the system operation of uncertainties caused by the differences between the chosen mathematical model and the real optimized system.
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Ishimoto, Takuya, Keita Kawahara, Aira Matsugaki, Jun Wang, Hiroshi Kamioka, and Takayoshi Nakano. "Analysis of Osteocyte Morphology in Terms of Sensation of In Vivo Stress Applied on Bone." Materials Science Forum 783-786 (May 2014): 1265–68. http://dx.doi.org/10.4028/www.scientific.net/msf.783-786.1265.
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Most bones are anisotropically loaded and seem to be adapted to the anisotropic stress or strain field by changing the anisotropy in their microstructure. Osteocyte (OCY) is believed to play an important role as a mechanosensor and regulator of modeling and/or remodeling orchestrating osteoblast and osteoclast activity to make bone suitable to resist the mechanical environment. In general, osteocytes sense magnitude of stress (strain) applied upon the bone and then work as a trigger to change bone mass to adjust bone’s mechanical function to the stress field. This structural optimization is an important aspect of the bone functional adaptation; another inevitable optimization might be achieved through the change in intrinsic material anisotropy including the preferential c-axis orientation of biological apatite (BAp) crystal. To achieve this adaptation through material anisotropy, osteocyte needs to be a mechanosensor which can detect anisotropic stress field. In the present study, osteocyte lacunae and canaliculi in the mid-diaphysis and the distal part of the rat femur were stained by a fluorescein dye for visualization and analysis. The mid-diaphysis shows greater degree of the preferential c-axis orientation of BAp crystal than the distal part in relation to the magnitude of uni-axial stress field. It was found that the osteocytes in long bone preferentially align along the bone long axis and the degree of alignment is greater in the mid-diaphysis than in the distal region, which seems to be effective for the sensation of the site-dependent specific stress field applied on the long bone.
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Greig, Joshua, and Natalia A. Bulgakova. "Interplay between actomyosin and E-cadherin dynamics regulates cell shape in the Drosophila embryonic epidermis." Journal of Cell Science 133, no. 15 (July 14, 2020): jcs242321. http://dx.doi.org/10.1242/jcs.242321.
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ABSTRACTPrecise regulation of cell shape is vital for building functional tissues. Here, we study the mechanisms that lead to the formation of highly elongated anisotropic epithelial cells in the Drosophila epidermis. We demonstrate that this cell shape is the result of two counteracting mechanisms at the cell surface that regulate the degree of elongation: actomyosin, which inhibits cell elongation downstream of RhoA (Rho1 in Drosophila) and intercellular adhesion, modulated via clathrin-mediated endocytosis of E-cadherin (encoded by shotgun in flies), which promotes cell elongation downstream of the GTPase Arf1 (Arf79F in Drosophila). We show that these two mechanisms do not act independently but are interconnected, with RhoA signalling reducing Arf1 recruitment to the plasma membrane. Additionally, cell adhesion itself regulates both mechanisms – p120-catenin, a regulator of intercellular adhesion, promotes the activity of both Arf1 and RhoA. Altogether, we uncover a complex network of interactions between cell–cell adhesion, the endocytic machinery and the actomyosin cortex, and demonstrate how this network regulates cell shape in an epithelial tissue in vivo.
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Weirich, Kimberly L., Shiladitya Banerjee, Kinjal Dasbiswas, Thomas A. Witten, Suriyanarayanan Vaikuntanathan, and Margaret L. Gardel. "Liquid behavior of cross-linked actin bundles." Proceedings of the National Academy of Sciences 114, no. 9 (February 15, 2017): 2131–36. http://dx.doi.org/10.1073/pnas.1616133114.
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The actin cytoskeleton is a critical regulator of cytoplasmic architecture and mechanics, essential in a myriad of physiological processes. Here we demonstrate a liquid phase of actin filaments in the presence of the physiological cross-linker, filamin. Filamin condenses short actin filaments into spindle-shaped droplets, or tactoids, with shape dynamics consistent with a continuum model of anisotropic liquids. We find that cross-linker density controls the droplet shape and deformation timescales, consistent with a variable interfacial tension and viscosity. Near the liquid–solid transition, cross-linked actin bundles show behaviors reminiscent of fluid threads, including capillary instabilities and contraction. These data reveal a liquid droplet phase of actin, demixed from the surrounding solution and dominated by interfacial tension. These results suggest a mechanism to control organization, morphology, and dynamics of the actin cytoskeleton.
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Chilton, Beverly S., and Aveline Hewetson. "Progesterone regulation of RUSH/SMARCA3/HLTF includes DNA looping." Biochemical Society Transactions 36, no. 4 (July 22, 2008): 632–36. http://dx.doi.org/10.1042/bst0360632.
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RUSH/SMARCA3 (SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily A, member 3) is capable of sequence-selective DNA binding and ATP-dependent DNA unwinding. In rabbit uterine epithelial cells, RUSH-1α (113 kDa) is the progesterone-dependent splice variant and RUSH-1β (95 kDa) is the oestrogen-dependent splice variant. Rabbit RUSH/SMARCA3 mRNA is primarily regulated at the proximal promoter (−162/+90) via a PRE (progesterone-response element) half-site/overlapping Y-box domain (−38/−26) and two Sp (specificity protein) 3 sites centred at −128 and −58. We investigated hormone regulation by exploring binding of transcription factors to a putative RUSH/SMARCA3 site (−616/−611) and the distal Sp3 (−131/−126) site. In response to progesterone, RUSH-1α binds the RUSH site and the Sp3 site becomes a functional binding site for Egr-1 (early growth-response gene product 1)/Sp (specificity protein)1/3/MAZ (Myc-associated zinc-finger protein)/MZF1 (myeloid zinc finger 1)/c-Rel. TransSignal TF–TF Interaction Arrays, supershift assays and ChIP (chromatin immunoprecipitation) analyses confirmed strong physical interactions between RUSH and Egr-1/c-Rel. Higher-order long-range interactions between RUSH and the Egr-1/c-Rel derivative of the anisotropic flexibility of the intervening DNA sequence were shown with 3C (chromosome conformation capture) assays. Transient transfection assays with mutant constructs showed the co-operative interaction between RUSH and Egr-1 mediates repression by c-Rel. Thus DNA-bound RUSH/SMARCA3 communicates with its own proximal promoter by looping the intervening DNA. Moreover, progesterone-dependent DNA looping is an adjunct to progesterone induction of the RUSH/SMARCA3 gene because the availability of RUSH isoforms and relevant binding partners is progesterone-regulated.
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Augustine, Sruthy Maria, Anoop V. Cherian, Divya P. Syamaladevi, and N. Subramonian. "Erianthus arundinaceusHSP70 (EaHSP70) Acts as a Key Regulator in the Formation of Anisotropic Interdigitation in Sugarcane (Saccharumspp. hybrid) in Response to Drought Stress." Plant and Cell Physiology 56, no. 12 (September 30, 2015): 2368–80. http://dx.doi.org/10.1093/pcp/pcv142.
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Haiza, Haroon, A. Azizan, Aizat Hazwan Mohidin, and D. S. C. Halin. "Green Synthesis of Silver Nanoparticles Using Local Honey." Nano Hybrids 4 (May 2013): 87–98. http://dx.doi.org/10.4028/www.scientific.net/nh.4.87.
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In this work, silver nanoparticles have been successfully prepared with a simple, cost-effective and reproducible aqueous room temperature green synthesis method. Honey was chosen as the eco-friendly reducing and stabilizing agent replacing most reported reducing agents such as hydrazine, sodium borohydride (NaBH4) and dimethyl formamide (DMF) which are highly reactive chemicals but also pose a biological risk to the society and environment. The size and shape of silver nanoparticles were modulated by varying the honey concentration and pH of the aqueous solution that contain silver nitrate as the silver precursor, sodium hydroxide as the pH regulator and ethylene glycol as the solvent. The silver nanoparticles obtained are characterized by field-emission scanning electron microscope (FESEM), ultraviolet-visible spectra (UV-Vis) and Fourier transform infrared spectroscopy (FTIR). From SEM analysis, it was found that by increasing the concentration of honey, the size of silver nanoparticles produced decreased, from the range of 18.98 nm - 26.05 nm for 10 g of honey to 15.63 nm - 17.86 nm for 40 g of honey. Similarly, the particle size decreased as the pH of the aqueous solution increased. UV-Vis spectra revealed large anisotropic and polydispersed Ag nanoparticle were produced.
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Nam, Dayeon, Yuki Matsumoto, Takeshi Uchida, Mark R. O'Brian, and Koichiro Ishimori. "Mechanistic insights into heme-mediated transcriptional regulation via a bacterial manganese-binding iron regulator, iron response regulator (Irr)." Journal of Biological Chemistry 295, no. 32 (June 17, 2020): 11316–25. http://dx.doi.org/10.1074/jbc.ra119.011855.
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The transcription factor iron response regulator (Irr) is a key regulator of iron homeostasis in the nitrogen-fixating bacterium Bradyrhizobium japonicum. Irr acts by binding to target genes, including the iron control element (ICE), and is degraded in response to heme binding. Here, we examined this binding activity using fluorescence anisotropy with a 6-carboxyfluorescein-labeled ICE-like oligomer (FAM-ICE). In the presence of Mn2+, Irr addition increased the fluorescence anisotropy, corresponding to formation of the Irr–ICE complex. The addition of EDTA to the Irr–ICE complex reduced fluorescence anisotropy, but fluorescence was recovered after Mn2+ addition, indicating that Mn2+ binding is a prerequisite for complex formation. Binding activity toward ICE was lost upon introduction of substitutions in a His-cluster region of Irr, revealing that Mn2+ binds to this region. We observed that the His-cluster region is also the heme binding site; results from fluorescence anisotropy and electrophoretic mobility shift analyses disclosed that the addition of a half-equivalent of heme dissociates Irr from ICE, likely because of Mn2+ release due to heme binding. We hypothesized that heme binding to another heme binding site, Cys-29, would also inhibit the formation of the Irr–ICE complex because it is proximal to the ICE binding site, which was supported by the loss of ICE binding activity in a Cys-29–mutated Irr. These results indicate that Irr requires Mn2+ binding to form the Irr–ICE complex and that the addition of heme dissociates Irr from ICE by replacing Mn2+ with heme or by heme binding to Cys-29.
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Matsugaki, Aira, Ryosuke Ozasa, Yoshihiro Isobe, Taro Saku, and Takayoshi Nakano. "Oriented Collagen Scaffolds for Anisotropic Bone Tissue Construction In Vitro." Materials Science Forum 783-786 (May 2014): 1303–6. http://dx.doi.org/10.4028/www.scientific.net/msf.783-786.1303.
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Constructing biomimetic tissue architecture in vitro holds the key to the realization of tissue engineering. To control the anisotropic microstructure of bone tissue which governs the mechanical properties of bone, especially, is imperative for the establishment of ideal bone regeneration process. In this study, highly aligned collagen scaffolds were fabricated to control osteoblast alignment. Collagen fibrillogenesis were regulated by an extrusion process, resulting in formation of biomimetic, hierarchically-aligned bony microstructure. Osteoblasts adhered to the fabricated scaffolds showed aligned morphology along the collagen orientation. In the present method, the degree of scaffold orientation is regulatable, which suggests that the designing of the appropriate scaffolds depending on the tissue anisotropy is possible. Interestingly, the bone matrix produced by the aligned osteoblasts exhibited anisotropic microstructure along the cell alignment. Our findings imply that controlling the osteoblast alignment by oriented collagen scaffolds could be an initiator to establish the anisotropic bone structural development or regeneration.
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Deng, Chao, Jue Hou, Xing Zhang, R. Hugh Gong, and Xiangyu Jin. "Controllable anisotropic properties of wet-laid hydroentangled nonwovens." March 2019 18, no. 3 (April 1, 2019): 173–80. http://dx.doi.org/10.32964/tj18.3.173.
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For nonwovens, fiber orientation distribution is an important structural characteristic that directly influences the anisotropic properties of the materials. Different Vslurry/Vbelt ratios were adopted to fabricate nonwovens during the wet-laid process. The results indicated that fiber orientation distribution of nonwovens can be regulated by adopting different Vslurry/Vbelt ratios owing to the web-forming principle of wet-laid techniques. Mechanical tests showed that both wet and dry tensile strength of nonwovens in different angle directions present anisotropy under different Vslurry/Vbelt ratio parameters. A liquid spreading distribution experiment proved that liquid spreading length and area of nonwovens could be manipulated using different Vslurry/Vbelt ratios in the fabrication process. Therefore, specific anisotropic properties of wet-laid hydroentangled nonwovens can be realized by controlling the process parameters for particular end-use applications.
Dissertations / Theses on the topic "Anisotropic regulator"
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Georgoulis, Emmanuil H. "Discontinuous Galerkin methods on shape-regular and anisotropic meshes." Thesis, University of Oxford, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270366.
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Хоменко, Віктор Віталійович. "Багатокритеріальний синтез систем із анізотропійними регуляторами на основі стохастичної мультиагентної оптимізації." Thesis, Українська інженерно-педагогічна академія, 2016. http://repository.kpi.kharkov.ua/handle/KhPI-Press/22705.
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Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.13.03 – системи та процеси керування. – Національний технічний університет "Харківський політехнічний інститут", Харків, 2016.
У роботі вирішена науково-практична задача підвищення точності керування багатомасовими електромеханічними системами з невизначеними параметрами на основі багатокритеріального підходу до стохастичних робастних методів. Розроблено метод багатокритеріального синтезу анізотропійних регуляторів для керування багатомасовими електромеханічними системами із параметричною невизначеністю. Багатокритеріальний синтез анізотропійних регуляторів зведено до рішення задачі векторного математичного нелінійного програмування, в якій обчислення векторної цільової функції і обмежень зводиться до ітеративного рішення системи з чотирьох пов'язаних рівнянь Ріккаті, рівняння Ляпунова та обчислення виразу спеціального виду. Удосконалено метод рішення багатокритеріальної задачі математичного програмування на основі багатороєвоі стохастичної мультиагентної оптимізації на основі Парето – оптимальних рішень. Досліджено динамічні характеристики синтезованих багатомасових електромеханічних систем з анізотропійними регуляторами, які синтезовані на основі багатокритеріального підходу. Застосування робастних регуляторів дозволило підвищити швидкодію системи за рахунок скорочення часу першого узгодження в 4,1 разів, зменшити помилку регулювання швидкості обертання при випадковій зміні моменту зовнішнього впливу більше ніж у 2 рази, системи до зміни параметрів об'єкту керування у порівнянні із системою з типовими регуляторами. Проведено експериментальні дослідження синтезованих систем із анізотропійними регуляторами на стенді стохастичної двомасової електромеханічної системи. Експериментально встановлено, що застосування анізотропійних регуляторів у стенді двомасової електромеханічної системи дозволило скоротити час першого узгодження регулювання швидкості у 2 рази, зменшити помилку регулювання швидкості обертання при випадковій зміні моменту зовнішнього впливу більше ніж у 2 рази у порівнянні із системою з типовими регуляторами.Thesis for scientific degree of candidate of engineering science on speciality 05.13.03 – control systems and processes. – National Technical University "Kharkiv Polytechnic Institute", Kharkiv, 2016. The thesis is devoted to solving scientific and practice task of increasing the accuracy of control multimass electromechanical systems with uncertain parameters on the basis of multiobjective approach to the synthesis of anisotropic regulators. A method of multiobjective synthesis of anisotropic regulators multimass electromechanical systems, which allows to meet the diverse requirements that apply to the work multimass electromechanical systems in various modes. Multiobjective synthesis of anisotropic regulators reduced to solution the vector nonlinear programming, in which the calculation of the objective function is algo-rithmic in nature, involving multiple solution of algebraic Riccati equations, Lyapunov equations and special expressions for calculating of anisotropy level. Improved method for solving multiobjective programming problem based on a stochastic multi-agent multi swarm optimization based on Pareto-optimal solutions. Investigated the dynamic characteristics of the synthesized multimass electro-mechanical systems with anisotropic regulators are synthesized from multi approach. The results of the comparisons of dynamic characteristics multimass electro-mechanical systems with synthesized anisotropic regulators and controller types. It is proved that the use of synthetic anisotropic regulators allowed to reduce time of the first coordination by 4.1 times, to reduce the error compensation of random external perturbation 2 times and to reduce the system sensitivity to changes of plant parameters compared to a system with standard controllers. Experimental on the stand two-mass electromechanical system found that the use of synthesized anisotropic regulators can reduce time of the first coordination by 2 times, reduce the error speed control for random change of the load torque is 2 times as compared with the system controller types.
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Хоменко, Віктор Віталійович. "Багатокритеріальний синтез систем із анізотропійними регуляторами на основі стохастичної мультиагентної оптимізації." Thesis, НТУ "ХПІ", 2016. http://repository.kpi.kharkov.ua/handle/KhPI-Press/22704.
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Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.13.03 – системи та процеси керування. – Національний технічний університет "Харківський політехнічний інститут", Харків, 2016.
У роботі вирішена науково-практична задача підвищення точності керування багатомасовими електромеханічними системами з невизначеними параметрами на основі багатокритеріального підходу до стохастичних робастних методів. Розроблено метод багатокритеріального синтезу анізотропійних регуляторів для керування багатомасовими електромеханічними системами із параметричною невизначеністю. Багатокритеріальний синтез анізотропійних регуляторів зведено до рішення задачі векторного математичного нелінійного програмування, в якій обчислення векторної цільової функції і обмежень зводиться до ітеративного рішення системи з чотирьох пов'язаних рівнянь Ріккаті, рівняння Ляпунова та обчислення виразу спеціального виду. Удосконалено метод рішення багатокритеріальної задачі математичного програмування на основі багатороєвоі стохастичної мультиагентної оптимізації на основі Парето – оптимальних рішень. Досліджено динамічні характеристики синтезованих багатомасових електромеханічних систем з анізотропійними регуляторами, які синтезовані на основі багатокритеріального підходу. Застосування робастних регуляторів дозволило підвищити швидкодію системи за рахунок скорочення часу першого узгодження в 4,1 разів, зменшити помилку регулювання швидкості обертання при випадковій зміні моменту зовнішнього впливу більше ніж у 2 рази, системи до зміни параметрів об'єкту керування у порівнянні із системою з типовими регуляторами. Проведено експериментальні дослідження синтезованих систем із анізотропійними регуляторами на стенді стохастичної двомасової електромеханічної системи. Експериментально встановлено, що застосування анізотропійних регуляторів у стенді двомасової електромеханічної системи дозволило скоротити час першого узгодження регулювання швидкості у 2 рази, зменшити помилку регулювання швидкості обертання при випадковій зміні моменту зовнішнього впливу більше ніж у 2 рази у порівнянні із системою з типовими регуляторами.Thesis for scientific degree of candidate of engineering science on speciality 05.13.03 – control systems and processes. – National Technical University "Kharkiv Polytechnic Institute", Kharkiv, 2016. The thesis is devoted to solving scientific and practice task of increasing the accuracy of control multimass electromechanical systems with uncertain parameters on the basis of multiobjective approach to the synthesis of anisotropic regulators. A method of multiobjective synthesis of anisotropic regulators multimass electromechanical systems, which allows to meet the diverse requirements that apply to the work multimass electromechanical systems in various modes. Multiobjective synthesis of anisotropic regulators reduced to solution the vector nonlinear programming, in which the calculation of the objective function is algo-rithmic in nature, involving multiple solution of algebraic Riccati equations, Lyapunov equations and special expressions for calculating of anisotropy level. Improved method for solving multiobjective programming problem based on a stochastic multi-agent multi swarm optimization based on Pareto-optimal solutions. Investigated the dynamic characteristics of the synthesized multimass electro-mechanical systems with anisotropic regulators are synthesized from multi approach. The results of the comparisons of dynamic characteristics multimass electro-mechanical systems with synthesized anisotropic regulators and controller types. It is proved that the use of synthetic anisotropic regulators allowed to reduce time of the first coordination by 4.1 times, to reduce the error compensation of random external perturbation 2 times and to reduce the system sensitivity to changes of plant parameters compared to a system with standard controllers. Experimental on the stand two-mass electromechanical system found that the use of synthesized anisotropic regulators can reduce time of the first coordination by 2 times, reduce the error speed control for random change of the load torque is 2 times as compared with the system controller types.
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Yu, Peng. "Allosteric regulation of glycerol kinase: fluorescence and kinetics studies." Diss., Texas A&M University, 2003. http://hdl.handle.net/1969.1/1537.
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Glycerol kinase (GK) from Escherichia coli is allosterically controlled by fructose 1,6-bisphosphate (FBP) and the glucose-specific phosphocarrier protein IIAGlc of the phosphotransferase system. These controls allow glucose to regulate glycerol utilization. Fluorescence spectroscopic and enzyme kinetic methods are applied to investigate these allosteric controls in this study. The linkage between FBP binding and GK tetramer assembly is solved by observation of homo-fluorescence energy transfer of the fluorophore Oregon Green (OG) attached specifically to an engineered surface cysteine in GK. FBP binds to tetramer GK with an affinity 4000-fold higher than to dimeric GK. A region named the coupling locus that plays essential roles in the allosteric signal transmission from the IIAGlc binding site to the active site was identified in GK. The relationship between the coupling locus sequence in Escherichia coli or Haemophilus influenzae GK variants and the local flexibility of the IIAGlc binding site is established by fluorescence anisotropy determinations of the OG attached to the engineered surface cysteine in each variant. The local flexibility of the IIAGlc binding site is influenced by the coupling locus sequence, and in turn affects the binding affinity for IIAGlc. Furthermore, the local dynamics of each residue in the IIAGlc binding site of GK is studied systematically by the fluorescence anisotropy measurements of OG individually attached to each position of the IIAGlc binding site. The fluorescence steady-state anisotropy measurement provides a valid estimation of the local flexibility and correlates well with the crystallographic B-factors. Steady-state kinetics of FBP inhibition shows that the data are best described by a model in which the partial inhibition and FBP binding stoichiometry are taken into account. Kinetic viscosity effects show that the product-release step is not the purely rate-limiting step in the GK-catalyzed reaction. Viscosity effects on FBP inhibition are also discussed.
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Sura, Giri Raju. "Studies of the relationship of protein structure to regulation and catalysis in tyrosine hydroxylase." Diss., Texas A&M University, 2003. http://hdl.handle.net/1969.1/5904.
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Tyrosine hydroxylase (TyrH) catalyzes the rate-limiting step in the synthesis of the catecholamine neurotransmitters dopamine, epinephrine, and norepinephrine. Phosphorylation of Ser40 of rat TyrH activates the enzyme by decreasing the affinity for catecholamines. In humans, there are four different TyrH isoforms with varying lengths for the regulatory domain. DOPA and dopamine binding studies were performed on the phosphorylated and unphosphorylated human isoforms. The Kd for DOPA was increased two times upon phosphorylation of hTyrH1, but no change was seen for hTyrH4; the Kd value decreased with the increase in the size of regulatory domain. The small effect on the Kd value for DOPA upon phosphorylation of hTyrH suggests that DOPA does not regulate the activity of hTyrH. Dopamine binds very tightly and upon phosphorylation the affinity for dopamine is decreased. This Kd value decreases with the increase in the length of the regulatory domain. The crystal structures of substrate complexes of the homologous enzyme phenylalanine hydroxylase (PheH) show a large movement of a surface loop (residues 131-155) upon amino acid binding. The corresponding loop residues (175-200) in TyrH play an important role in DOPA formation. This conformational change in TyrH loop was studied with fluorescence anisotropy. Three tryptophan residues in the TyrH, at positions 166, 233, and 372, were mutated to phenylalanine, and Phe184 was mutated to tryptophan. An increase in anisotropy was observed in the presence of phenylalanine and 6-methyl-5-deazatetrahydropterin (6M5DPH4), but the magnitude of the change of anisotropy with 6M5DPH4 was greater than that with phenylalanine. Further characterization of the sole tryptophan in the loop showed a decrease in the amplitude of the local motion only in the presence of 6M5DPH4 alone. The conformational change in wild type TyrH was examined by H/D exchange LC/MS spectroscopy in the presence of the natural ligands. Time-course dependent deuterium incorporation into the loop in the presence of ligands indicated that the pterin alone can induce the conformational change in the loop irrespective of whether iron is reduced or oxidized. From these results, one can conclude that the loop undergoes a conformational change upon pterin binding, making the active site better for amino acid binding.
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Siddiqui, Tabrez Jamal. "SNARE assembly and regulation on membranes." Doctoral thesis, 2006. http://hdl.handle.net/11858/00-1735-0000-0006-B5F0-D.
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Pecqueur, Ludovic. "Etude du rôle du zinc et des cystéines dans la dimérisation de la protéine FUR (Ferric Uptake Regulator) d'E.coli : une approche structurale par RMN." Phd thesis, 2005. http://tel.archives-ouvertes.fr/tel-00011629.
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La protéine FUR (Ferric Uptake Regulator) est un régulateur global ubiquitaire chez les bactéries Gram-négatives. Sa liaison au Fe2+, in vivo, entraîne la répression de l'expression des gènes qu'elle contrôle. Ce travail est une étude structurale par RMN de la forme dimérique non activée de FUR d'Escherichia coli, un dimère de 2*17 kDa contenant un ion zinc par monomère. Une forme monomérique oxydée, capable de dimériser en présence de réducteur et de zinc, a également été isolée et étudiée. Le dichroïsme circulaire et la RMN montrent que la dimérisation entraîne une structuration du domaine C-terminal lors de l'incorporation du zinc. Les structures secondaires du domaine N-terminal du monomère et du dimère sont très proches. Seuls les premiers résidus sont structurés en hélice Α dans le monomère et déstructurés dans le dimère non activé. Cette hélice, observée dans le dimère activé de FUR de P. aeruginosa, pourrait jouer un rôle dans le mécanisme de régulation. Une protéine tronquée (FUR1-82) a été construite, purifiée, cristallisée. Sa structure est superposable à celle du domaine N-terminal de FUR de P. aeruginosa et le spectre 1H-15N-HSQC est superposable aux signaux du domaine N-terminal de FUR monomère. L'étude, par anisotropie de fluorescence, de la liaison du monomère et du dimère à l'ADN montre qu'ils se lient spécifiquement à l'ADN en présence de métal, contrairement à la forme tronquée. L'affinité du monomère pour l'ADN est 5 fois plus faible que celle du dimère en excès de métal. L'ensemble de ces données nous a permis de proposer un mécanisme de dimérisation de FUR d'E. coli ainsi qu'un mécanisme d'activation mettant en jeu cette hélice Α N-terminale.
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Νομικός, Δημήτριος. "Διαφορική θεωρία Galois και μη-ολοκληρωσιμότητα του ανισοτροπικού προβλήματος Stormer και του ισοσκελούς προβλήματος τριών σωμάτων." Thesis, 2010. http://nemertes.lis.upatras.gr/jspui/handle/10889/3876.
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Στην παρούσα διατριβή μελετήσαμε την ολοκληρωσιμότητα του ανισοτροπικού προβλήματος Størmer (ASP) και του ισοσκελούς προβλημάτος τριών σωμάτων (IP), με εφαρμογή της θεωρίας Morales-Ramis-Simó. Τα αποτελέσματα της μελέτης δημοσιεύθηκαν στο περιοδικό Physica D: Nonlinear Phenomena.
Ένα σύστημα Hamilton SH, Ν βαθμών ελευθερίας, είναι ολοκληρώσιμο (κατά Liouville) όταν επιδέχεται Ν συναρτησιακώς ανεξάρτητα και σε ενέλιξη πρώτα ολοκληρώματα. Οι J.J. Morales-Ruiz, J.P. Ramis και C. Simó απέδειξαν ότι αν ένα SH είναι ολοκληρώσιμο, τότε η ταυτοτική συνιστώσα G0k της διαφορικής ομάδας Galois των εξισώσεων μεταβολών VE¬k τάξης k , που αντιστοιχούν σε μια ολοκληρωτική καμπύλη του SH, είναι αβελιανή.
Το ASP μπορεί να θεωρηθεί ότι είναι ένα σύστημα Hamilton δυο βαθμών ελευθερίας που περιέχει τις παραμέτρους pφ και ν2>0, το οποίο περιγράφει την κίνηση ενός φορτισμένου σωματιδίου υπό την επίδραση του μαγνητικού πεδίου ενός διπόλου. Οι Α. Almeida, T. Stuchi είχαν αποδείξει ότι το ASP είναι μη-ολοκληρώσιμο για pφ≠0 και ν2>0, ενω για pφ=0 είχαν αποδείξει τη μη-ολοκληρωσιμότητα των περιπτώσεων που αντιστοιχούν στις τιμές ν2≠5/12, 2/3. Η δική μας διερεύνηση απέδειξε ότι το ASP με pφ=0 (ASP0) είναι, επίσης, μη-ολοκληρώσιμο για ν2=5/12, 2/3. Αρχικά, με χρήση της μεθόδου Yoshida, αναλύσαμε τις G01 των VE¬1, που αντιστοιχούν σε δύο ολοκληρωτικές καμπύλες του ASP0, καταλήγοντας ότι οι G01 είναι μη-αβελιανές για ν2≠2/3. Στη συνέχεια, ορίσαμε τις VE3 κατά μήκος μιας τρίτης ολοκληρωτικής καμπύλης του ASP0 και δείξαμε ότι η αντίστοιχη G03 είναι μη-αβελιανή για ν2=2/3. Σύμφωνα με τη θεωρία Morales-Ramis-Simó, τα προαναφερόμενα αποδεικνύουν τη μη-ολοκληρωσιμότητα του ASΡ για pφ=0 και ν2>0.
Το ΙΡ είναι μια υποπερίπτωση του προβλήματος τριών σωμάτων και μπορεί να μελετηθεί ως ένα σύστημα Hamilton δύο βαθμών ελευθερίας με παραμέτρους pφ και m, m3>0. Η προγενέστερη ανάλυση του ΙΡ υπεδείκνυε τη μη-ολοκληρωσιμότητα του συστήματος, όμως είχε πραγματοποιηθεί με χρήση αριθμητικών μεθόδων. Βρίσκοντας από μια ολοκληρωτική καμπύλη για κάθε μια απο τις περιπτώσεις pφ=0, pφ≠0, ορίσαμε τις αντίστοιχες VE1 και αποδείξαμε τη μη-ολοκληρωσιμότητα του ΙΡ. Για pφ=0 χρησιμοποιήσαμε τη μέθοδο Yoshida για να μελετήσουμε την G01, ενώ για pφ≠0 εφαρμόσαμε τον αλγόριθμο Kovacic και ερευνητικά αποτελέσματα των D. Boucher, J.A. Weil για να διερευνήσουμε την αντίστοιχη G01. Οι G01 και στις δυο προαναφερόμενες περιπτώσεις είναι μη-αβελιανές, οπότε το ΙΡ είναι μη-ολοκληρώσιμο, σύμφωνα με τη θεωρία Morales-Ramis-Simó.In the present dissertation we studied the integrability of the anisotropic Stormer problem (ASP) and the isosceles three-body problem (IP), applying the Morales-Ramis-Simo theory. The results of our study were published by the journal Physica D: Nonlinear Phenomena. A Hamiltonian system SH, of N degrees of freedom, is integrable (in the Liouville sense) if it admits an involutive set of N functionally independent first integrals. J.J. Morales-Ruiz, J.P. Ramis and C. Simó proved that if an SH is integrable, then the identity component G0k of the differential Galois group of the variational equations VE¬k of order k that correspond to an integral curve of the SH, is abelian. The ASP can be considered as a Hamiltonian system of two degrees of freedom that contains the parameters pφ and ν2>0, which describes the motion of a charged particle under the influence of the magnetic field of a dipole. Α. Almeida, T. Stuchi had proved that the ASP is non-integrable for pφ≠0 and ν2>0, while for pφ=0 they had proved the non-integrability of the cases that correspond to ν2≠5/12, 2/3. Our study proved that the ASP with pφ=0 (ASP0) is, also, non-integrable for ν2=5/12, 2/3. Initially, using the Yoshida method, we analysed the G01 of the VE¬1, that correspond to two integrals curves of the ASP0, concluding that they are non-abelian for ν2≠2/3. Then, we defined the VE3 along a third integral curve of the ASP0 and indicated that the corresponding G03 is non-abelian for ν2=2/3. According to the Morales-Ramis-Simó theory, the aforementioned considerations prove the non-integrability of the ASP for pφ=0 and ν2>0. The IP is a special case of the three-body problem and it can be treated as a Hamiltonian system of two degrees of freedom that embodies the parameters pφ and m, m3>0. Previous analysis of the IP suggested the non-integrability of the system, but it was performed with the use of numerical methods. Finding an integral curve for each of the cases pφ=0, pφ≠0, we defined the corresponding VE1 and proved the non-integrability of the IP. For pφ=0 we used the Yoshida method to examine G01 , while for pφ≠0 we applied the Kovacic algorithm and some results of D. Boucher, J.A. Weil to investigate the corresponding G01 . In both of the aforementioned cases the G01 were non-abelian, yielding IP non-integrable, according to the Morales-Ramis-Simó theory.
Book chapters on the topic "Anisotropic regulator"
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Vashakmadze, Tamaz S. "Theories with Regular Processes." In The Theory of Anisotropic Elastic Plates, 55–142. Dordrecht: Springer Netherlands, 1999. http://dx.doi.org/10.1007/978-94-017-3479-0_3.
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Parygin, V. N. "Acousto-Optical Interaction in Media with Regulated Anisotropy." In Physical Acoustics, 77–85. Boston, MA: Springer US, 1991. http://dx.doi.org/10.1007/978-1-4615-9573-1_8.
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Kopilevich, Yu I. "Regular inhomogeneous anisotropic elastic waveguides: an implementation of the abstract theory." In Spectral Theory of Guided Waves, 211–72. Boca Raton: CRC Press, 2021. http://dx.doi.org/10.1201/9781003209645-7.
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Katsikadelis, J. T., and N. G. Babouskos. "Optimum Design of Thick Laminated Anisotropic Plates via Frequency Regulation. A BEM Approach." In Advanced Structured Materials, 223–39. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-70563-7_10.
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Albing, Carl, Norm Troullier, Stephen Whalen, Ryan Olson, Joe Glenski, Howard Pritchard, and Hugo Mills. "Scalable Node Allocation for Improved Performance in Regular and Anisotropic 3D Torus Supercomputers." In Recent Advances in the Message Passing Interface, 61–70. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-24449-0_9.
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Ting, T. T. C. "Particular Solutions, Stress Singularities, and Stress Decay." In Anisotropic Elasticity. Oxford University Press, 1996. http://dx.doi.org/10.1093/oso/9780195074475.003.0012.
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Not all boundary value problems are amenable to a simple analytical solution. This is particularly the case when the geometry of the boundary on which the boundary conditions are specified contains a corner. A crack tip is a special corner. When an analytical solution for the entire region is not available, asymptotic solutions near the corner can be obtained which provide useful information on the nature of stress singularities at the corner. They also provide more accurate numerical solutions by a finite element scheme in which the asymptotic solution at the corner is employed in a special element at the corner with regular elements elsewhere (see, for example, Stolarski and Chiang, 1989). Other information that can be obtained by an asymptotic analysis is the decay factor of stress at a large distance from a point at which a self-equilibrated load is applied (Crafter, et al., 1993). For singularities that arise in non-linear elastic materials the reader is referred to the book by Antman (1995). As in Chapter 8 most solutions can be expressed in a real form with the aid of identities presented in Chapters 6 and 7.
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Bouchez, Jean-Luc, and Adolphe Nicolas. "Technical aspects of tectonics." In Principles of Rock Deformation and Tectonics, 199–222. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780192843876.003.0010.
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Practical tools that can be useful in tectonic studies are briefly examined in this chapter. Field geologists will find some of these tools to be theoretical and conceptual (e.g., tensors), while a few, such as the universal stage (mounted on an optical microscope), are rarely used in the 21st century. It was routinely employed in the previous century, particularly in crystallography, before the advent of modern (but costly) techniques that use X-rays, neutrons or secondary electrons, which will be also discussed. A good handling of orientation data on 2D-projections (Schmidt or Wulff nets) continues to be very practical and of regular use to geologists. The chapter will end with brief introduction to digital imagery and magnetic studies (Anisotropy of Magnetic Susceptibility, AMS) that help to define shape preferred orientations (SPOs) in rocks, and with gravity techniques that are also commonly in practice in geological studies.
Conference papers on the topic "Anisotropic regulator"
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Ye, Suiying, Arvind Sridhar, Luca Del Carro, Paul McCloskey, Ansar Masood, and Thomas Brunschwiler. "Anisotropic Composite Core Material for Inductor-based Fully Integrated Voltage Regulator." In 2019 22nd European Microelectronics and Packaging Conference & Exhibition (EMPC). IEEE, 2019. http://dx.doi.org/10.23919/empc44848.2019.8951870.
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"Learning the changes of barnase mutants thermostability from structural fluctuations obtained using anisotropic network modeling." In Bioinformatics of Genome Regulation and Structure/ Systems Biology. institute of cytology and genetics siberian branch of the russian academy of science, Novosibirsk State University, 2020. http://dx.doi.org/10.18699/bgrs/sb-2020-372.
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Bartkowiak, Tomasz. "Characterization of 3D Surface Texture Directionality Using Multi-Scale Curvature Tensor Analysis." In ASME 2017 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/imece2017-71609.
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Anisotropy of surface texture can in many practical cases significantly affect the interaction between the surface and phenomena that influence or are influenced by the topography. Tribological contacts in sheet forming, wetting behavior or dental wear are good examples. This article introduces and exemplifies a method for quantification and visualization of anisotropy using the newly developed 3D multi-scale curvature tensor analysis. Examples of a milled steel surface, which exhibited an evident anisotropy, and a ruby contact probe surface, which was the example of isotropic surface, were measured by the confocal microscope. They were presented in the paper to support the proposed approach. In the method, the curvature tensor T is calculated using three proximate unit vectors normal to the surface. The multi-scale effect is achieved by changing the size of the sampling interval for the estimation of the normals. Normals are estimated from regular meshes by applying a covariance matrix method. Estimation of curvature tensor allows determination of two directions around which surface bends the most and the least (principal directions) and the bending radii (principal curvatures). The direction of the normal plane, where the curvature took its maximum, could be plotted for each analyzed region and scale. In addition, 2D and 3D distribution graphs could be provided to visualize anisotropic or isotropic characteristics. This helps to determine the dominant texture direction or directions for each scale. In contrast to commonly used surface isotropy/anisotropy determination techniques such as Fourier transform or autocorrelation, the presented method provides the analysis in 3D and for every region at each scale. Thus, different aspects of the studied surfaces could clearly be seen at different scales.
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Tsvankin, Vadim, Dmitry Belchenko, Devon Scott, and Wei Tan. "Anisotropic Strain Effects on Vascular Smooth Muscle Cell Physiology." In ASME 2007 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2007. http://dx.doi.org/10.1115/sbc2007-176284.
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Biological development is a complex and highly-regulated process, a significant part of which is controlled by mechanostimulus, or the strain imparted on a cell by its environment. Mechanostimulus is important for stem cell differentiation, from cytoskeletal assembly to cell-cell and cell-matrix adhesion [1]. The mechanics of cells and tissues play a critical role in organisms, under both physiological and pathological conditions; abnormal mechanotransduction — the mechanism by which cells sense and respond to strain — has been implicated in a wide range of clinical pathologies [2,3].
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Takahashi, Wataru, Norikazu Suzuki, and Eiji Shamoto. "Design of Anisotropic Boring Tools With L/D = 10 for Chatter Free Cutting." In ASME 2017 12th International Manufacturing Science and Engineering Conference collocated with the JSME/ASME 2017 6th International Conference on Materials and Processing. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/msec2017-2928.
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This paper presents design of a novel boring bar with a ratio of cylinder length to diameter (L/D) of 10 to suppress chatter vibration regardless of low stiffness. It is essentially difficult to decrease the compliance of the long slender structures. However, nominal compliance of the displacement along the depth of cut direction against the resultant cutting force may be regulated by giving the designated anisotropy upon the boring bar dynamics. The past research has clarified the feasibility through turning experiments by using the developed boring bar with L/D of 4. In the present study, much slenderer ones with L/D of 10 are designed, which are significantly flexible but attractive to manufacturers. Finite element analysis (FEA) is utilized to estimate dynamics of the anisotropic boring bar. Through analytical investigations, two kinds of boring bars were designed, where the compliance ratio of 1.53 or 1.88 was accomplished. Influence of several conditions on the chatter stability was investigated. Analytical investigations revealed that the chatter stability is significantly improved at a designated depth of cut by utilizing the proposed designs regardless of feed rate. In particular, the compliance ratio of 1.55 showed wider stable zone to attain chatter free boring, while chatter avoidance is impossible by use of the conventional isotropic boring bar under the same conditions.
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Kumar, A. R., D. A. Achimov, T. Zeng, and G. Chen. "Thermal Conductivity of Nanochanneled Alumina." In ASME 2000 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/imece2000-1452.
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Abstract We present an experimental study on the thermal conductivity of anodized alumina with regular nanochannels. Thermal conductivity values in both directions parallel and perpendicular to the nanochannel axis are measured at room temperature using the 3ω technique. An anisotropic heat conduction model is developed to analyze the experimental data.
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Baglietto, Emilio. "Anisotropic Turbulence Modeling for Accurate Rod Bundle Simulations." In 14th International Conference on Nuclear Engineering. ASMEDC, 2006. http://dx.doi.org/10.1115/icone14-89646.
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An improved anisotropic eddy viscosity model has been developed for accurate predictions of the thermal hydraulic performances of nuclear reactor fuel assemblies. The proposed model adopts a non-linear formulation of the stress-strain relationship in order to include the reproduction of the anisotropic phenomena, and in combination with an optimized low-Reynolds-number formulation based on Direct Numerical Simulation (DNS) to produce correct damping of the turbulent viscosity in the near wall region. This work underlines the importance of accurate anisotropic modeling to faithfully reproduce the scale of the turbulence driven secondary flows inside the bundle subchannels, by comparison with various isothermal and heated experimental cases. The very low scale secondary motion is responsible for the increased turbulence transport which produces a noticeable homogenization of the velocity distribution and consequently of the circumferential cladding temperature distribution, which is of main interest in bundle design. Various fully developed bare bundles test cases are shown for different geometrical and flow conditions, where the proposed model shows clearly improved predictions, in close agreement with experimental findings, for regular as well as distorted geometries. Finally the applicability of the model for practical bundle calculations is evaluated through its application in the high-Reynolds form on coarse grids, with excellent results.
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TADIE. "LOWER BOUNDS FOR LARGE SOLUTIONS OF SOME ANISOTROPIC PROBLEMS IN REGULAR BOUNDED DOMAINS." In Proceedings of the International Conference on Differential Equations. WORLD SCIENTIFIC, 2005. http://dx.doi.org/10.1142/9789812702067_0201.
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Huang, Siyao, and Hsiao-Ying Shadow Huang. "Tissue- and Cell-Level Stress Distributions of the Heart Valve Tissue During Diastole." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-63229.
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Heart valves are inhomogeneous microstructure with nonlinear anisotropic properties and constantly experience different stress states during cardiac cycles. However, how tissue-level mechanical forces can translate into altered cellular stress states remains unclear, and associated biomechanical regulation in the tissue has not been fully understood. In the current study, we use an image-based finite element method to investigate factors contributing the stress distributions at both tissue- and cell-levels inside the healthy heart valve tissues. Effects of tissue microstructure, inhomogeneity, and anisotropic material property at different diastole states are discussed to provide a better understanding of structure-mechanics-property interactions, which alters tissue-to-cell stress transfer mechanisms in heart valve tissue. To the best of the authors’ knowledge, this is the first study reporting on the evolution of stress fields at both the tissue- and cellular-levels in valvular tissue, and thus contributes toward refining our collective understanding of valvular tissue micromechanics while providing a computational tool enabling further study of valvular cell-tissue interactions.
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Ahsanizadeh, Sahand, and LePing Li. "Strain-Rate Sensitive Constitutive Modeling of Anisotropic Visco-Hyperelastic Materials." In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-88608.
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Integral-based formulations of viscoelasticity have been widely used to describe the mechanical behavior of soft biological tissues and polymers. However, it is suggested that they are not suitable to be used under high strain rates. On the other hand, strain-rate sensitive models with an explicit dependence on the strain-rate have been developed for a certain class of materials. They predict the viscoelastic behavior during ramp loading more accurately while fail to account for the relaxation response. In order to overcome these drawbacks, a viscoelastic constitutive model has been proposed in this study based on the concept of internal variables. While the behavior of elastic materials is uniquely determined by the current state of deformation or external variables, the mechanical response of inelastic materials are regulated also by internal variables. The internal variables are associated with the dissipative mechanisms in the material and along with the evolution equations introduce the effect of history of the deformation to the current configuration. The current study employs short-term and long-term internal variables to account for the viscoelastic response during loading and relaxation respectively.