14 research outputs found
Self-adaptive approach for optimisation of passive control systems for seismic resistant buildings
The concept of passive control of the seismic response of structures was introduced to improve the performance of structures by increasing their energy dissipation and reduce or eliminate damage in the structural elements. The key task in the design of passive systems is to determine the forces in the control devices (yield/slip or post-tensioning) at each floor, that will result in best performance (e.g. minimum inter-storey drift). This can be achieved by large parametric studies in which both the maximum control force (e.g. at ground level) and the distribution of forces along the height of the structure are varied. Alternatively, optimum forces in the devices can be achieved by semi-active control, where the structure self-adapts to the earthquake. Both solutions are expensive: the first requires hundreds of non-linear response simulations in the design stage; the second needs a system of sensors, controllers and electromechanical devices. Presented here is a new Self Adaptive Optimisation Approach (SAOA) in which the self-optimisation of a semi-active system is used in the design stage and the resulting distribution of control forces is adopted as a passive system. The new approach was evaluated through comparing the simulated dynamic responses of two relatively simple benchmark structures (braced and post-tensioned) with three sets of control forces: (1) passive system with forces obtained in parametric study, (2) semi-active system with self-adapting control forces, and (3) passive system with SAOA-optimized forces. The results show good performance of the SAOA systems, indicating that SAOA offers a simple and effective solution that can replace the existing optimisation approaches for the design of passively controlled earthquake resistant structures. This study presents a novel idea of using the semi-active control as a tool for optimising a passive control system. The passive control systems can be further improved by a larger study in which the semi-active control algorithms are also optimised
Torsion mitigation of existing asymmetric structures using damper
Many existing buildings are irregular in plan or elevation because of asymmetric placement of masonry infills. The stiffness of masonry infill is a considerable value relating to that of the structure. Produced torsion from eccentricity because of infill stiffness leads to extra forces and deformations in structural members and diaphragms. An appropriate alternative to solve this problem especially in existing buildings is using dampers. Dampers can enhance structural performance by reducing seismically induced lateral displacements and by reducing inelastic behavior of beams and columns. In this paper some simple models are used to show structural modeling and a conceptual discussion is presented on the numerical results. An accurate model for masonry infill has been used in structural model. Numerical results show the efficiency and high performance of added dampers to reduce the torsion effects in the structural elements
IMMUNOHISTOCHEMICAL EXPRESSION OF HEPATOCYTE GROWTH FACTOR/c-MET IN THE HEART AND AORTA OF DIABETIC RATS
Context. Diverse physiological or pathological events which are stimulated or contributed by HGF/c-Met pathway overlap by processes that play roles in etiopathogenesis of diabetes
Increased availability of family donors for hematopoietic stem cell transplantation in a population with increased incidence of consanguinity
The study was planned to determine the frequency of parental and non-sibling family donor transplants in our center and to investigate the rate of familial donor availability at two HLA-typing laboratories in Turkey. Among 203 patients who underwent hematopoietic stem cell transplantation (HSCT), 151 (74.4%) received stem cells from siblings, 48 (23.6%) from non-sibling family donors, two (1.0%) from unrelated cord blood, and two (1.0%) autologous transplantation. Of these 48 patients received stem cells from non-sibling family donors; donors were mothers for 26 (12.8%), fathers for 20 (9.9%), and aunts for two (1.0%). The rate of transplants from parental donors was 22.6% in this patient population with increased frequency of inherited diseases (58.1%). Among these 203 patients, there was consanguinity between parents in 60.6% of the patients. Of 833 subjects applying as donor candidates to HLA-typing laboratories, 527 (63.3%) had HLA 6/6 identical family donors. Among 527 full-matched donors, 479 (90.9%) were sibling, 21 (4.0%) were fathers, and 17 (3.2%) were mothers. The remaining 10 (1.9%) were other relatives. The results have shown that the unfavorable factor of consanguinity marriage may increase the availability of family donors for HSCT in particularly developing countries where large donor registries are lacking. © 2010 John Wiley & Sons A/S
Paralytic And Nonparalytic Muscle Adaptations To Exercise Training Versus High-Protein Diet In Individuals With Long-Standing Spinal Cord Injury
This study compares the effects of an 8-wk isocaloric high-protein (HP) diet versus a combination exercise (Comb-Ex) regimen on paralytic vastus lateralis (VL) and nonparalytic deltoid muscle in individuals with long-standing spinal cord injury (SCI). Fiber-type distribution, cross-sectional area (CSA). levels of translation initiation signaling proteins (Erk-1/2, Akt, p70S6K1, 4EBP1, RPS6, and FAK), and lean thigh mass were analyzed at baseline and after the 8-wk interventions. A total of 11 participants (C5-T12 levels, 21.8 +/- 6.3 yr postinjury; 6 Comb-Ex and 5 HP diet) completed the study. Comb-Ex training occurred 3 days/wk and consisted of upper body resistance training (RT) in addition to neuromuscular electrical stimulation (NMES)-induced-RT for paralytic VL muscle. Strength training was combined with high-intensity arm-cranking exercises (1-min intervals at 85-90%, (V) over dotO(2peak)) for improving cardiovascular endurance. For the HP diet intervention, protein and fat each comprised 30%. and carbohydrate comprised 40% of total energy. Clinical tests and muscle biopsies were performed 24 h before and after the last exercise or diet session. The Comb-Ex intervention increased Type IIa myofiber distribution and CSA in VL muscle and Type I and IIa myofiber CSA in deltoid muscle. In addition, Comb-Ex increased lean thigh mass, (V) over dotO(2peak), and upper body strength (P < 0.05). These results suggest that exercise training is required to promote favorable changes in paralytic and nonparalytic muscles in individuals with long-standing SCI, and adequate dietary protein consumption alone may not be sufficient to ameliorate debilitating effects of paralysis. NEW & NOTEWORTHY This study is the first to directly compare the effects of an isocaloric high-protein diet and combination exercise training on clinical and molecular changes in paralytic and nonparalytic muscles of individuals with long-standing spinal cord injury. Our results demonstrated that muscle growth and fiber-type alterations can best be achieved when the paralyzed muscle is sufficiently loaded via neuromuscular electrical stimulation-induced resistance training.Wo