Дисертації з теми "Spinal loads"
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1
Dennis, Gary. "Spinal Loads in Team Lifting." Thesis, Griffith University, 2003. http://hdl.handle.net/10072/367181.
Повний текст джерелаАнотація:
In the first experiment, spinal loads during individual and two-person team lifting tasks were compared. Ten healthy male subjects performed symmetrical individual lifts with a box mass of 15, 20 and 25 kg and symmetrical two-person team lifts with 30, 40 and 50 kg from the floor to standing knuckle height. Results indicated that the torque and compression force experienced by the lumbar spine were approximately 20% lower during team lifts compared to the load-matched individual lifting tasks. The two main and equal contributing factors reducing spinal load during team compared to individual lifting tasks were: (i) the increased horizontal pulling force and (ii) the ability of the team to hold the load at the ends of the box, which reduced the moment arm of the load. The second experiment assessed the effect of relative team member height (matched versus unmatched) on lumbar spinal loads during two-person team lifting tasks. Twelve young healthy male subjects performed matched and unmatched team lifts with two box masses (30 and 60 kg) and three initial box heights (0, 20 and 40 cm). Matched team members had standing heights within 5%, whilst unmatched teams had an average standing height difference of 25 ± 2.5 cm. Although spinal loads were reduced for the shorter subjects and increased for the taller subjects at the end of the lift, no significant difference was found in the maximum spinal loads incurred during matched compared to unmatched lifting conditions. In the final experiment the relationship between load mass distribution and the relative spinal loads incurred by each of the individual team members during two-person team lifting tasks was examined. Two-person lifting teams were required to lift a box containing a mass of 30 kg or 60 kg from the floor to standing knuckle height. Adjusting the position of the centre of mass within the box by ± 15 cm and ± 7.5 cm relative to the evenly distributed position (0 cm) yielded three load mass distribution ratios (69:31, 59:41 and 50:50), which represented the percentage of the total mass lifted by each team member. Although the spinal load incurred by the team member lifting at the heavier end of the load was greater than for the person at the lighter end of the load, the difference between the spinal loads incurred by each team member was not as great as the difference in the asymmetric distribution of the load mass. Subsequent investigation of the factors influencing spinal load indicated that the spinal loads experienced by the team member at the heavier end of the load was less than expected because they generated a larger horizontal pulling force than their lifting partner. Consequently, during the lift the load translated toward the team member at the heavier end of the load, which combined with the larger horizontal pulling force reduced the extensor torque required at the lumbar spine. Overall, results from this study have demonstrated that: (i) the lifting strategy used by two-person teams is distinguished from individual lifts by a greater use of horizontal pulling forces applied to the load and a decreased distance between the load and the lumbar spine, (ii) both the horizontal pulling force and the position of the hands on the load in team lifting have a load relieving effect on the lumbar spine and (iii) two-person team lifts performed by team members of unmatched standing height and with asymmetrical load mass appear to be coordinated in a manner that partially mitigates the increased spinal loads for the team member at increased risk of spinal injury.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Physiotherapy and Exercise Science
Griffith Health
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Boocock, Mark Graham. "An ergonomic appraisal of the mechanical loads imposed on the human spinal column during impact landing." Thesis, Liverpool John Moores University, 1992. http://researchonline.ljmu.ac.uk/4942/.
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Wang, Xueke. "Does visual access when lifting unstable objects affect the biomechanical loads experienced by the spine and shoulders." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1492722421190945.
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Jaafar, Kamal Rachid. "Spiral shear reinforcement for concrete structures under static and seismic loads." Thesis, University of Cambridge, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.616166.
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5
Wang, Tianjiao. "Feasibility for spinal muscles creating pure axial compressive load or follower load in the lumbar spine in 3-D postures." Diss., University of Iowa, 2015. https://ir.uiowa.edu/etd/1790.
Повний текст джерелаАнотація:
Previous in-vivo studies showed that compressive force acting on the spine may exceed 2600 N. However, the ligamentous lumbar spine becomes unstable when subjected to compressive loads less than 100 N. It is generally accepted that the ligamentous spine itself is unstable but can be stabilized by muscle forces (MFs) in vivo. Nevertheless, normal spinal muscle contraction patterns remain unknown.
In recent in vitro studies, when the direction of the applied load was controlled along the spinal curvature so that the internal spinal load became perfect compressive follower loads (CFLs) at all lumbar levels, the ligamentous lumbar spine was found to withstand large compressive load (up to 1200 N) without buckling while maintaining its flexibility in neutral or flexed postures. The results of in-vivo animal studies also have shown that shear stress has a more detrimental effect on the rate of disc degeneration compared to compressive stress. These results suggest CFLs in the lumbar spine would be a normal spinal load whereas the transverse (or shear) load abnormal. An initial test of this postulation would be to investigate whether the spinal muscles can create perfect internal CFLs in the lumbar spine in all 3-D postures. In addition, small intrinsic muscles (SIMs) are crucial for better control of the direction of the internal spinal load along the spinal axis was also proposed.
A finite element (FE) model together with an optimization model were used for this study. Both models consist of the trunk, sacrolumbar spine and 244 spinal muscles. Different from other studies, 54 SIMs were also included in the models. The FE model was validated by comparing the ROM of the spine with the literature data. Minimization of the summation of the spinal loads and moments was used as the cost function for the optimization model. The geometrical data obtained from the FE model was used as the input for the optimization model; it was then used to calculate the MFs required for creating the CFLs at all lumbar spine levels. The MFs determined in the optimization model were then imported back to the FE model as input loads to check the stability of the spine under this loading condition. Five different postures were studied: neutral, flexion 40°, extension 5°, lateral bending 30° and axial rotation 10°.
Many optimization solutions for spinal muscle force combinations creating pure CFLs in the lumbar spine were found available in each posture. However, FE analyses showed that only muscle forces and patterns solved at FLPs along the curve in the vicinity of the baseline curve stabilized the lumbar spine. Stability was determined by small displacement of the trunk (less or equal to 5mm) due to small deformation of the lumbar spine. The magnitudes of joint reaction forces (JRFs) predicted from the optimization model were comparable to those reported in the literature. When the SIMs were removed, optimization solutions were still feasible in all five postures, but JRFs and trunk displacement were increased. This suggests the need of SIM inclusion in future spine biomechanics studies and clinically, damages to the SIMs may have a high risk of future spinal problems, such as spinal instability, early disc degeneration, deformity and/or early failure of spinal fixation devices.
The results from this study supported the hypothesis that the perfect CFLs at all lumbar levels could be the normal physiological load under which the lumbar spinal column could support large load without buckling while allowing flexibility. SIMs played an important role in creating CFLs as by including SIMs in the models, the JRFs at all lumbar spine levels were lowered and the stability of the spine was increased.
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Bakker, E. W. P. "Spinal mechanical load. A risk factor for non-specific low back pain." [S.l.] : Rotterdam : [The Author] ; Erasmus University [Host], 2008. http://hdl.handle.net/1765/14715.
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Mokwa, Robert L. "Investigation of the Resistance of Pile Caps to Lateral Loading." Diss., Virginia Tech, 1999. http://hdl.handle.net/10919/29152.
Повний текст джерелаАнотація:
Bridges and buildings are often supported on deep foundations. These foundations consist of groups of piles coupled together by concrete pile caps. These pile caps, which are often massive and deeply buried, would be expected to provide significant resistance to lateral loads. However, practical procedures for computing the resistance of pile caps to lateral loads have not been developed, and, for this reason, cap resistance is usually ignored.
Neglecting cap resistance results in estimates of pile group deflections and bending moments under load that may exceed the actual deflections and bending moments by 100 % or more. Advances could be realized in the design of economical pile-supported foundations, and their behavior more accurately predicted, if the cap resistance can be accurately assessed.
This research provides a means of assessing and quantifying many important aspects of pile group and pile cap behavior under lateral loads. The program of work performed in this study includes developing a full-scale field test facility, conducting approximately 30 lateral load tests on pile groups and pile caps, performing laboratory geotechnical tests on natural soils obtained from the site and on imported backfill materials, and performing analytical studies. A detailed literature review was also conducted to assess the current state of practice in the area of laterally loaded pile groups.
A method called the "group-equivalent pile" approach (abbreviated GEP) was developed for creating analytical models of pile groups and pile caps that are compatible with established approaches for analyzing single laterally loaded piles. A method for calculating pile cap resistance-deflection curves (p-y curves) was developed during this study, and has been programmed in the spreadsheet called PYCAP.
A practical, rational, and systematic procedure was developed for assessing and quantifying the lateral resistance that pile caps provide to pile groups. Comparisons between measured and calculated load-deflection responses indicate that the analytical approach developed in this study is conservative, reasonably accurate, and suitable for use in design. The results of this research are expected to improve the current state of knowledge and practice regarding pile group and pile cap behavior.Ph. D.
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Richard, Leeland. "Spiral Welded Pipe Piles For Structures In Southeastern Louisiana." ScholarWorks@UNO, 2010. http://scholarworks.uno.edu/td/1257.
Повний текст джерелаАнотація:
In an effort to obtain 100-year level hurricane protection for southeastern Louisiana, the U.S. Army Corps of Engineers (USACE) has implemented design guidelines that both levees and structures shall be designed to. Historically, USACE has used concrete piles or steel H-piles as the foundations for these structures. Because of the magnitude of obtaining 100-year level hurricane protection, limited resources, and a condensed timeline, spiral welded pipe piles can be manufactured as an alternative to either the concrete piles or steel H-piles. This research will provide the necessary background for understanding pile foundations, will compare the behaviors of spiral welded pipe piles to that of other piles with respect to geotechnical concerns through a series of pile load tests, and will offer a current cost analysis. This background, testing, and cost analysis will show that spiral welded pipe piles are a viable alternative for USACE structures from a geotechnical and economic perspective.
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Ramsey, Todd R. "The Effects of Load-Positioning Material Handling Equipment on Spinal Loading During Manual Handling of Bulk Bags." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1368027435.
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Usman, Irfan-ur-rab. "Rotary-axial spindle design for large load precision machining applications." Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/30163.
Повний текст джерелаАнотація:
Normal stress electromagnetic actuators can be used as both an axial bearing and an in-feed motor in precision machine tool applications that require only millimeter-range axial stroke, such as silicon wafer face grinding or meso-machining. The rotary cutting stage may be integrated with the axially-feeding stage in a rotary-axial architecture. This typology allows the use of independent rotary and axial actuators acting on a single moving mass, rather than an axial actuator moving an entire rotary motor assembly in the feed direction as in typical machine tool architectures. Non-collocated resonances are therefore minimized and thrust and radial stiffness is increased through the elimination of intermediate lateral and thrust bearings, and achievable closed loop positioning performance is improved.
This thesis presents the working principle, design, and analysis of radially-biased electromagnetic bearing/actuators for large load precision rotary-axial spindle applications, and the integration of such an actuator in a full scale prototype to be used as a silicon wafer face grinder. The experimental results indicate that the rotary-axial spindle with radially-biased thrust bearing/actuator is capable of achieving less than 7 nm resolution over a 1.5 mm axial stroke, a worst case load capacity of approximately 5000 N and a best case load capacity of over 8000 N, with rotary-axial coupling of less than 30 nm axial error at 3000 rpm.
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RINDER, MARIA M. "Three-Dimensional Dynamic Biomechanical Model for Lifting and Lowering Activities: Systematic Review, Critical Appraisal and Model Development." University of Cincinnati / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1179430261.
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Sugyarto, Eddy. "The Kinematic Study, Geometry Generation, and Load Distribution Analysis of Spiral Bevel and Hypoid Gears." The Ohio State University, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=osu1392985391.
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13
Erkilic, Erdem. "A Model to Predict Pocketing Power Losses in Spiral Bevel and Hypoid Gears." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1337616576.
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Ssemakula, Hamzah. "Minimization of stock weight during close-die forging of a spindle." Högskolan Dalarna, Materialteknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:du-12555.
Повний текст джерелаАнотація:
In this paper, Finite Element method and full-scale experiments have been used to study a hot forging method for fabri-cation of a spindle using reduced initial stock size. The forging sequence is carried out in two stages. In the first stage, the hot rolled cylindrical billet is pre-formed and pierced in a closed die using a spherical nosed punch to within 20 mm of its base. This process of piercing or impact extrusion leads to high strains within the work piece but requires high press loads. In the second stage, the resulting cylinder is placed in a die with a flange chamber and upset forged to form a flange. The stock mass is optimized for complete die filling. Process parameters such as effective strain distribution, material flow and forging load in different stages of the process are analyzed. It is concluded from the simulations that minor modifications of piercing punch geometry to reduce contact between the punch and emerging vertical walls of the cylinder appreciably reduces the piercing load. In the flange chamber, a die surfaces angle of 52° instead of 45° is pro-posed to ensure effective material flow and exert sufficient tool pressure to achieve complete cavity filling. In order to achieve better compression, it is also proposed to shorten both the length of the inserted punch and the die “tongues” by a few mm.
15
Song, Ino. "The effect of variations in the strength and type of spinal muscles on the stabilization of the lumbar spine via follower compressive load mechanism." Thesis, University of Iowa, 2017. https://ir.uiowa.edu/etd/5638.
Повний текст джерелаАнотація:
The ligamentous human lumbar spine is considered as a long and slender column, which can be buckled when subjected to the axial compressive load even less than 100N. However, previous in vivo study showed that the compressive force acting on the spine predicted by intradiscal pressure was exceed 2600N. Meanwhile, recent experiments suggested that, when the compressive force is subjected to the lumbar spine along the spinal curvature (follower load), the lumbar spine may support up to a compressive force of 1200N without buckling while maintaining its flexibility. Since such a follower load is directed tangential to the curved column over the entire length, the lumbar spine subjected to a follower load should experience only pure compressive force components with zero shear force components.
It is generally agreed that the ligamentous lumbar spine can be stabilized by applying the muscle forces (MFs) in vivo creating follower compressive loads (FCLs). In previous studies, computational model of the lumbar spine showed the feasibility for spinal muscles to stabilize the lumbar spine via the FCL mechanism, which supports the hypothesis of FCLs as normal physiological loads in the spine in-vivo. In addition, the muscle forces of short intrinsic muscles (SIMs), such as interspinales, intertransversarii, and rotatores may increase the stability of the lumbar spine (i.e., deflection of the spinal column or trunk sway) significantly. However, the mechanical roles of SIMs for spinal stability have not been quantified and understood well.
A finite element (FE) model with optimization model of the lumbar spinal system was used in this study. Both models were consisted of 122 pairs of spinal muscle fascicles including 54 SIMs fascicles. The variation of spinal muscle strength was simulated by changing the values of MFCs of long muscles as well as SIMS from zero to 90 N/cm2. Five different MFC conditions of both long muscles and SIMs in the spinal system were investigated in five different postures, which are neutral standing, flexion 40°, extension 5°, left axial rotation 10°, and right lateral bending 30°. The trunk displacement (TD) and joint loads including joint reaction forces (JRFs) and moments (JRMs) predicted from 25 cases of MFC variation were compared in order to investigate the effect of the strength of spinal muscles on the stabilization of the lumbar spine in a given posture.
The results showed that small trunk sways (< 2mm) were predicted when MFCs of both long muscles and SIMs were average or higher regardless of the spinal postures. In contrast, no optimum solution or unstable conditions were predicted in many cases of the weakening of the long muscles, especially in flexion and lateral bending postures. Although the FCLs were created in most of the cases regardless of MFC-S when working with strong long muscles, higher joint loads were predicted as a result of weakening of SIMs. In addition, even if the long muscles were strong, absence of SIMs induced spine buckling in some cases of extension and axial rotation postures.
The results from this study imply that although the effect of MFCs variation of long muscle and/or SIMs was varied depending the spinal postures, the simultaneous use of both SIMs and long muscles is necessary for stabilization of the spine in any physiological posture with minimum joint loads for maximum safety.
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Yantzer, Brenda Kay. "Torsion-Induced Pressure Distribution Changes in Human Intervertebral Discs: an In Vitro Study." [Tampa, Fla] : University of South Florida, 2005. http://purl.fcla.edu/usf/dc/et/SFE0001397.
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Пестунов, В. М., В. В. Свяцький, Л. П. Свяцька, V. Pestunov, V. Sviatskyi та L. Sviatska. "Імітація силового навантаження на шпиндель". Thesis, Publishing House „Education and science” s.r.o, 2009. http://dspace.kntu.kr.ua/jspui/handle/123456789/6514.
Повний текст джерелаАнотація:
Розглянуто пристрій для імітації силового навантаження на шпиндель, що виникають при його обертовому і поступальному рухах. The device for simulating a power load on a spindle, which arise at its rotary and translational motions is considered.
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Nedbal, David. "Návrh manuální pravoúhlé frézovací hlavy určené pro technologické operace na středně těžkých obrobcích." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-382413.
Повний текст джерелаАнотація:
This thesis deals with mechanical design of right-angle manual milling head for headstock of horizontal boring machine of Fermat production. The thesis includes research of milling head types, Fermat production heads, but also heads of competition companies with similar parameters like designed head. Design part of thesis is about describing used components of chosen solution. The thesis includes also technical report describing calculation of load spectrum from machining, design of gears, calculation of reactions in spindle bearings, spindle deformation and control of spindle bearings. The end of the thesis describes financial evaluation including also comparation with competitive milling heads with similar parameters.
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Roulois, Guillaume. "Etude et simulation du bruit des boîtes de transmission principales d'hélicoptères." Thesis, Dijon, 2011. http://www.theses.fr/2011DIJOS105.
Повний текст джерелаАнотація:
La boîte de transmission principale (BTP) est une des principales sources dubruit perçu dans les cabines d’hélicoptères et pénalise fortement le confort acoustique deséquipages et passagers. Afin de réduire l’impact de cette source, les phénomènes acoustiqueset vibratoires mis en jeu par les boîtes de transmission à engrenages doivent être compris etsimulés durant les phases de développement. De cette façon, le comportementvibroacoustique des BTP pourra être amélioré dès la conception, réduisant ainsi le coût, lamasse et les difficultés d’intégration des solutions d’insonorisation. Ce travail présente lesBTP d’hélicoptères ainsi que le bruit qu’elles génèrent. Il présente également nosdéveloppements concernant la modélisation du comportement dynamique des BTP afin d’encalculer le bruit. Nous avons développé un code éléments finis permettant d’effectuer desétudes paramétriques afin d’ajuster le design des boîtes de transmission lors des phases dedéveloppement. Notre modèle est capable de calculer les efforts dynamiques aux paliers detransmissions composées de plusieurs engrenages cylindriques et spiro-coniques. Enfin, nousanalysons des mesures acoustiques et vibratoires effectuées autour de deux BTP pourplusieurs conditions de couple et vitesse. Ces mesures nous permettent de mieux comprendrele comportement vibroacoustique des BTP et de confirmer certaines tendances observées avecnotre modèleMain gearbox (MGB) is one of the main noise sources in helicopter cabinsand it strongly penalizes acoustic comfort of crews and passengers. In order to reduce theimpact of this source, acoustic and vibration mechanisms of gearboxes have to be understoodand simulated during the development phases. By this way, MGB vibroacoustic behaviourcould be improved by design, thus reducing cost, additional weight and integration difficultiesof sound-proofing solutions. This work presents helicopters MGB and the noise they generate.It also presents our developments regarding the modelling of MGB dynamic behaviour fornoise computation. We have developed a finite elements code allowing to conduct parametricstudies to tune the gearboxes design in early development phases. Our model is able tocompute dynamic loads on bearings of any transmission composed of several cylindrical andspiral bevel gears. At last, we analyse acoustic and vibration measurements done around twoMGB for several conditions of torque and speed. These measurements allow to betterunderstand MGB vibroacoustic behaviour and to confirm some trends observed with ourmodel
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Pavelka, Radomil. "Pohon vřeten pětivřetenového soustružnického automatu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231522.
Повний текст джерелаАнотація:
The subject of the thesis is design of independent spindle drive for multi-spindle automatic lathe MORI-SAY TMZ 520 CNC manufactured by TAJMAC-ZPS. The thesis will introduce the representatives of manufacturing program of TAJMAC-ZPS multi-spindle automatic lathes division and there will be a brief description of their main constructional parts. The main objective of the thesis is an engineering design of testing device which will be bulit for verification of the correct drive concept. There is also many calculations and detailed description of the engineering design. The testing device is made for internal needs of TAJMAC-ZPS.
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Cabral, Fábio Aparecido Barbosa. "Avaliação da carga viral plasmática do HTLV-1 em indivíduos assintomáticos e desenvolvendo a mielopatia associada ao HTLV-1/paraparesia espástica tropical (HAM/TSP)." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/42/42132/tde-06102010-171847/.
Повний текст джерелаАнотація:
O vírus linfotrópico das células T humanas tipo 1 (HTLV-1), é responsável por patologias como a mielopatia associada ao HTLV-1 ou paraparesia espástica tropical (HAM/TSP) e a leucemia/linfoma das células T do adulto (ATL) dentre outras. As vias de replicação até hoje demonstradas, não suportam a hipótese de um estado virêmico. Neste estudo, a detecção de partículas virais plasmáticas foi executada, por PCR em Tempo Real e Nested PCR em 190 amostras de pacientes infectados pelo HTLV-1(assintomáticos ou com HAM/TSP), em acompanhamento, no Instituto de Infectologia Emílio Ribas. 12 indivíduos (8%) testados por PCR em tempo real (n=150) e 6 indivíduos (18%) testados por Nested PCR (n=33, dado que sete amostras foram excluídas da análise) apresentaram RNA do HTLV-1 detectável no plasma. Em conclusão, foi possível identificar RNA plasmático do HTLV-1, tanto em pessoas assintomáticas quanto com HAM/TSP. Esta detecção abre novas possibilidades de discussão sobre a replicação do HTLV-1 e das vias de transmissão, sugerindo maiores investigações para elucidar o assunto.The human T-cell lymphotropic virus type1 (HTLV-1) is responsible for some pathologies such as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and Adult T-cell Leukemia/ Lymphoma (ATL) among others. Its ways of replication so far presented do not support the hypothesis of a viremic stage. In this study, the detection of the plasmatic viral load was performed by real time PCR and Nested PCR in 190 samples from HTLV-1 infected individuals (Either Asymptomatic or HAM/TSP cases) following up at Instituto de Infectologia Emílio Ribas. 12 individuals (8%) tested by Real time PCR (n= 150) and 6 individuals (18%) tested by Nested PCR (n= 33, given that 7 samples were excluded from the analysis) presented detectable HTLV-1 RNA in the plasma. In conclusion, it was possible to indentify HTLV-1 plasmatic RNA in asymptomatic carriers as well as in HAM/TSP cases. This detection opens new possibilities of discussion about HTLV-1 replication and transmission pathways, suggesting further investigation for clarifying this matter.
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Ching-Fang, Chang, and 張靜芳. "THE SPINAL CURVATUREUNDER VARIOUS LOADS IN DEADLIFT." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/67554606874059916174.
Повний текст джерелаАнотація:
碩士國立臺灣體育學院
體育研究所
93
ABSTRACT The purposes of this study were to estimate the deformation of spinal curve and to evaluate the strategies of weight-lifting in deadlift with different loading. Four males (age: 26.8 ± 3.3 years, height: 162 ± 5 cm, weight: 58.8 ± 5.8 kg) and four females (age: 21.5 ± 1.8 years, height: 162 ± 4 cm, weight: 61.3 ± 6.5 kg) who are national powerlifting athletes were recruited in this study. Each subject was asked to perform the deadlift in the motion laboratory with 30%, 50%, 70%, and 90% of his/her peak performance of deadlift. The VICON 612 motion analysis system was used to record the trajectories of reflective markers that were placed on the skin surface of spinal landmark. The information of landmarks of spine was used to calculate the displacements and the curvature angles of the spine. Repeated measures one-way ANVOA and Duncan post hoc tests were used to test the statistical differences for kinematical parameters with the alpha level .05. The results showed that the displacements of the 7th cervical spine (C7) and the 6th thoracic spine (T6) in the loading of 90% of the peak performance of deadlift and the inclination of trunk in saggittal plane were significantly greater than that in 30% and 50% of loading of the peak performance during the stage of prior-movement. The results of Kyphosis angle showed that the range of motion in the loading of 90% of the peak performance was significantly greater than that in the loading of 30% and 50% of the peak performance during the stage of prior-movement, the stage of movement, and the total stage of movement. It indicated that the powerlifting athletes increased the displacement of trunk and the angle of kyphosis posteriorly during the stage of prior-movement for the treatment of increase loading. Under the situation of larger loading, the powerlifting athletes adopted the strategy of pre-acted upper trunk and held the angle of kyphosis to perform the movement of deadlift.
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Diederich, Jennifer Marie. "Estimate of muscle contribution to spinal loads during continuous passive motion for low back pain." 2005. http://edissertations.library.swmed.edu/pdf/DiederichJ051105/DiederichJennifer.pdf.
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Beaucage-Gauvreau, Erica. "Brace for it: assessing lumbar spinal loads for a braced arm-to-thigh lifting and bending technique using a musculoskeletal modelling approach." Thesis, 2019. http://hdl.handle.net/2440/120550.
Повний текст джерелаАнотація:
Manual material handling activities that involve forward bending and lifting have been identified as risk factors for the development of low back pain, due to the spinal loads and postures experienced during these tasks. Several activities of daily living, such as lifting light-to-moderate objects, gardening, and cleaning, require forward bending and lifting. Many of these tasks can be performed with one hand, therefore allowing for trunk support by placing the free hand on the ipsilateral thigh. This “braced arm-to-thigh technique” (BATT) could especially benefit individuals with low back pain (LBP). However, the BATT has not been evaluated biomechanically in this specific population, and has not been evaluated when applied to tasks other than lifting. The overall goal of this thesis was to evaluate the effect of a bracing force, applied by the hand on the ipsilateral thigh, on lumbar spine loading and trunk kinematics for symmetrical and asymmetrical bending and lifting tasks, using a newly developed and validated full-body musculoskeletal model with a detailed lumbar spine. In Study 1 (Chapter 4), an OpenSim full-body model was developed and validated by adapting an existing OpenSim jogging model to be suitable for lifting motions. Muscle activations predicted by the resulting Lifting Full-Body (LFB) model were directly compared to muscle activations measured with electromyography (EMG), during various lifting tasks. Good agreement, both with respect to pattern and timing, was observed for the back musculature. Comparison between model estimates of intradiscal pressures (IDP) and in vivo IDP measurements also showed strong agreement. The spinal loads estimated by the model matched the trends reported for vertebral body replacement (VBR) measurements in older individuals for similar lifting tasks. This study demonstrated that the LFB model is suitable to evaluate changes in lumbar loading during symmetrical and asymmetrical lifting. In Study 2 (Chapter 5), trunk kinematics and L4/L5 spine loading for the BATT were compared to those of three common unsupported two-handed and one-handed lifting techniques for two loading conditions (2 kg and 10 kg), in 20 healthy participants (30-70 years old) matched in age and gender to 18 participants. The thigh bracing force, measured by a load cell secured to the thigh with a custom apparatus, significantly reduced L4/L5 extension moments, compressive and antero-posterior (AP) shear forces, compared to unsupported lifting techniques. However, the BATT technique also increased asymmetrical L4/L5 moments and trunk angles. In Study 3 (Chapter 6), the BATT was adapted to three activities of daily living (ADLs) to understand the effect of thigh bracing on lumbar loading and spine kinematics in tasks other than lifting. These three tasks, namely weeding (gardening), reaching for objects in low cupboards, and car egress, were simulated in the laboratory, using custom apparatus, by ten healthy young males. The BATT reduced L4/L5 extension moments, compressive and AP shear forces compared to self-selected techniques. This thesis presents the first validated full-body OpenSim model suited to estimating lumbar spine loading in symmetrical and asymmetrical lifting tasks, with or without external loads. Using this LFB model, it was demonstrated that the BATT reduces lumbar extension moments, compression and AP shear forces for lifting tasks and other ADLs, compared to unsupported techniques, for healthy and LBP populations.Thesis (Ph.D.) -- University of Adelaide, School of Mechanical Engineering, 2019
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Choi, Hyeonki. "Muscle forces and spinal loads in the human neck an EMG experiment and a comparison of three modeling methods /." 1996. http://catalog.hathitrust.org/api/volumes/oclc/36554082.html.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--University of Wisconsin--Madison, 1996.Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 56-67).
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Zheng, Qi-Cong, and 鄭琦聰. "Dynamic Analysis of High Speed Spindle with Axial Loads." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/26209044348668600478.
Повний текст джерела
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Park, Joon-Hyuk. "Wearable Torso Exoskeletons for Human Load Carriage and Correction of Spinal Deformities." Thesis, 2016. https://doi.org/10.7916/D81V5F5G.
Повний текст джерелаАнотація:
The human spine is an integral part of the human body. Its functions include mobilizing the torso, controlling postural stability, and transferring loads from upper body to lower body, all of which are essential for the activities of daily living. However, the many complex tasks of the spine leave it vulnerable to damage from a variety of sources. Prolonged walking with a heavy backpack can cause spinal injuries. Spinal diseases, such as scoliosis, can make the spine abnormally deform. Neurological disorders, such as cerebral palsy, can lead to a loss of torso control. External torso support has been used in these cases to mitigate the risk of spinal injuries, to halt the progression of spinal deformities, and to support the torso. However, current torso support designs are limited by rigid, passive, and non-sensorized structures. These limitations were the motivations for this work in developing the science for design of torso exoskeletons that can improve the effectiveness of current external torso support solutions. Central features to the design of these exoskeletons were the abilities to sense and actively control the motion of or the forces applied to the torso. Two applications of external torso support are the main focus in this study, backpack load carriage and correction of spine deformities. The goal was to develop torso exoskeletons for these two applications, evaluate their effectiveness, and exploit novel assistive and/or treatment paradigms.
With regard to backpack load carriage, current torso support solutions are limited and do not provide any means to measure and/or adjust the load distribution between the shoulders and the pelvis, or to reduce dynamic loads induced by walking. Because of these limitations, determining the effects of modulating these loads between the shoulders and the pelvis has not been possible. Hence, the first scientific question that this work aims to address is What are the biomechanical and physiological effects of distributing the load and reducing the dynamic load of a backpack on human body during backpack load carriage?
Concerning the correction of spinal deformities, the most common treatment is the use of a spine brace. This method has been shown to effectively slow down the progression of spinal deformity. However , a limitation in the effectiveness of this treatment is the lack of knowledge of the stiffness characteristics of the human torso. Previously, there has been no means to measure the stiffness of human torso. An improved understanding of this subject would directly affect treatment outcomes by better informing the appropriate external forces (or displacements) to apply in order to achieve the desired correction of the spine. Hence, the second scientific question that this work aims to address is How can we characterize three dimensional stiffness of the human torso for quantifiable assessment and targeted treatment of spinal deformities?
In this work, a torso exoskeleton called the Wearable upper Body Suit (WEBS) was developed to address the first question. The WEBS distributes the backpack load between the shoulders and the pelvis, senses the vertical motion of the pelvis, and provides gait synchronized compensatory forces to reduce dynamic loads of a backpack during walking. It was hypothesized that during typical backpack load carriage, load distribution and dynamic load compensation reduce gait and postural adaptations, the user’s overall effort and metabolic cost. This hypothesis was supported by biomechanical and physiological measurements taken from twelve healthy male subjects while they walked on a treadmill with a 25 percent body weight backpack. In terms of load distribution and dynamic load compensation, the results showed reductions in gait and postural adaptations, muscle activity, vertical and braking ground reaction forces, and metabolic cost. Based on these results, it was concluded that the wearable upper body suit can potentially reduce the risk of musculoskeletal injuries and muscle fatigue associated with carrying heavy backpack loads, as well as reducing the metabolic cost of loaded walking.
To address the second question, the Robotic Spine Exoskeleton (ROSE) was developed. The ROSE consists of two parallel robot platforms connected in series that can adjust to fit snugly at different levels of the human torso and dynamically modulate either the posture of the torso or the forces exerted on the torso. An experimental evaluation of the ROSE was performed with ten healthy male subjects that validated its efficacy in controlling three dimensional corrective forces exerted on the torso while providing flexibility for a wide range of torso motions. The feasibility of characterizing the three dimensional stiffness of the human torso was also validated using the ROSE. Based on these results, it was concluded that the ROSE may alleviate some of the limitations in current brace technology and treatment methods for spine deformities, and offer a means to explore new treatment approaches to potentially improve the therapeutic outcomes of the brace treatment.
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Chen, Y. C., and 陳雅娟. "The Spiral Grid Routing Protocol for Load Balancing in Wireless Sensor Network." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/30079047447724372952.
Повний текст джерелаАнотація:
碩士中華大學
資訊工程學系(所)
97
In recent years, “Network Grid” technology has been dramatically improved. New techniques are keeping revealed it gradually becomes the new generation of internet. Also, with the developing of wireless network communication technology, “Network Grid” technology has made significant contribution on resource management. Such as Remote Sensing, Automatic Data Acquisitions, Special Species Protection are all become reality. The administrators now do not have to travel a long distance to investigate the field. It also saves a lot of time and budget to get the data they want. First, in the sensor network, spread many sensor nodes over the area to acquire the environmental data. Then return the data to Sink or user via the wireless data acquirer through wireless network. Because the first concern of sensor hardware design are low cost, low profile, low battery power consumption. Since the battery of sensor is not easy to replaceable, efficiently power management is a very challenge research topic. The communication and sensing activity within the network will drain a lot of energy inside the sensor. To save the energy and extend the life time of network, one can reduce the redundancy overlay coverage of detection area, select robust and fast Routing Protocol, and reduce the impact of Duplicate Data. Recently, there are many routing protocol methods focus on data communication have been proposed by academic researchers. This thesis also proposed a new method which is called “Spiral Grid Routing Protocol, SGR”. The main purpose is to let the grids moving like a spiral curves to change working sensors then distribute the power consumption over the other sensors. So Loading Balance will be improved. Better performance has been obtained through experimental result.
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Hung, Yu-Bin, and 洪裕賓. "Identification of dynamic load for a built-in motor spindle." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/95428109761233540728.
Повний текст джерелаАнотація:
碩士國立成功大學
機械工程學系碩博士班
93
The thesis built the dynamic electron-mechanical analytical model to analysis the speed and current response for a built-in motor spindle under the dynamic milling load. In addition, it is also applied to estimate the dynamic milling load with the voltage, current and spindle speed. The model integrated the induction motor dynamic subsystem model and milling load model. After building the system model, the motor’s electronics parameters, spindle inertial and cutting constant can be identified from the experiments. Then, the nonlinear system model is applied to predict the current, power and speed of the spindle motor with the numerical method. Besides, it is developed to estimate the milling dynamic load when the current, voltage, and speed are captured. Due to the difficulty of the complex nonlinear system to realized the system characteristics. The simple model is built to explain the relation between the input harmonic force and output harmonic speed. The relation between the current and milling load is also estimated by the spectrum convolution theorem. Finally, the feasibility of the theorem is verified by the milling experiments.
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Wang, Ming-Jheng, and 王明正. "Tool Wear Fuzzy Detection Based on the Machine Tool's Spindle Load." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/11351979308896545612.
Повний текст джерелаАнотація:
碩士逢甲大學
機械與電腦輔助工程學系
105
In the present automation technology development, artificial intelligence is having a huge impact on manufacturing throughout the world. Monitoring abnormal condition during machining process an important inspection, but during the machining, the tool wear will affect the quality of the workpiece and the production costs and efficiency. This study is based on the detection of tool wear through an indirect monitoring on the machine spindle motor current load. The milling experiment was first carried out based on the spindle load, the spindle load was measured under different cutting conditions, the spindle load was then converted into power, the cutting power was obtained, and the X, Y and Z cutting forces were tested by the dynamometer. The main cutting force acting on the tool is calculated, and the membership degree of the cutting force of the spindle is then analyzed through triangular membership function. The wear interval of the tool is determined by fuzzy monitoring. Finally, the feasibility and validity this study is obtained, for easy set-up and other high cost detection method, this study may be another option for tool wear detection.
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Wang, Chuen-Ren, and 王春仁. "Dynamic Analysis of a Rotating Shaft with Elastic Bearing Subjected to a Harmonic Moving Spiral Load." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/99920845929162148202.
Повний текст джерелаАнотація:
碩士國立中正大學
機械工程所
98
This study mainly studies which the dynamic response of a rotating shaft subjected to the harmonic effect of the moving spiral load. This study regard the rotating shaft as Rayleigh beam and is used the global assumed mode method (GAMM) which simulates the dynamic deflection of a rotating shaft, and the two end support is simulated to the springs, this study propose the distribution of a spiral load is mainly derived from the type of the arrangement of the steel ball between the nut and ball screw, and consider this load subjected to the effect of the different swing frequency. Through the Lagargian Approach is derived the equation of motion, then the dynamic response of a rotating shaft is solved by the Runge-Kutta method, and discuss the effect of the dynamic response of a rotating shaft with respect to the different moving load speed and different rotational speed of a shaft, meanwhile, this study also discuss the dynamic response of a rotating shaft subjected to different swing frequency of the moving and rotating concentrated load, and compare result of moving spiral load each other. The results show that the maximum lateral deflection of a rotating shaft subjected to the harmonic spiral load is smaller between triple and quadruple than the harmonic moving and rotating concentrated load, when the bearing stiffness is smaller than 10^11 (N/m) and 10^8 (N/m), the two end displacement of a rotating shaft of beta=0.15 and beta=0.03 subjected to the moving and rotating concentrated load and the moving spiral load has obvious increase, respectively. In addition, the different moving speed of the concentrated load and spiral load affect the dynamic response apparently, the different rotating speed of a shaft has not almost affect the dynamic response of a rotating shaft, and the effect of lateral dynamic response subjected the variable magnitude of a swing angle is more smaller than the axial dynamic response.
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Тенета, Яна Володимірівна. "Дослідження навантаження на головну лінію прокатного стана «Блюмінг»". Магістерська робота, 2021. https://dspace.znu.edu.ua/jspui/handle/12345/5882.
Повний текст джерелаАнотація:
Тенета Я. В. Дослідження навантаження на головну лінію прокатного стана «Блюмінг» : кваліфікаційна робота магістра спеціальністі 133 "Галузеве машинобудування" / наук. керівник К .В. Таратута. Запоріжжя : ЗНУ, 2021. 97 с.UA : В роботі проведено огляд і аналіз науково-технічних рішень підвищення навантажувальної здатності вузлів та деталей головної лінії обтискного прокатного стана. Проведено розрахунки навантажень, що діють на деталі привода валків. Досліджено роботу універсальних шпинделів в умовах критичних навантажень. Запропоновано шляхи збільшення їх ресурсу.
EN : The paper provides an overview and analysis of scientific and technical solutions for increasing the load capacity of units and parts of the main line of the blooming mill. Calculations of the loads acting on the parts of the roll drive have been made. The work of universal spindles under critical loads has been investigated. Ways to increase their resource are proposed.
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HANDIKA, NURAZIZ, and NURAZIZ HANDIKA. "Shear Behavior of Tied and Multi-Spiral Columns with High Strength Steel and Concrete Under Low Axial Load." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/vhpe9p.
Повний текст джерелаАнотація:
碩士國立臺灣科技大學
營建工程系
100
ABSTRACT The development of High Strength Concrete (HSC) and High Strength Steel (HSS) facilitate the realization of high-rise building especially in seismic region to resist earthquake excitation. Innovative multi-spiral shear reinforcement which is designed for square cross section column offers technical and cost advantages comparing to conventional tied column stirrup. This research has objective to recognize the shear behavior of two types of stirrups with high strength steel and concrete under low axial load. The square hoops columns and multi-spiral columns are tested under 20% and 10% axial load ratio, respectively. Concrete compressive strength (70 MPa and 100 MPa) and spacing of the transverse reinforcement are two parameters that will be examined. Longitudinal and transversal reinforcements with specified yield strengths of 685 MPa and 785 MPa, respectively, are considered. Critical crack angle; shear strain and curvature; stress of transverse reinforcement; effect of axial compression load of six large-scale columns will be explained. Test results show that the maximum strength of columns appears before the yielding of stirrups. Thus, stress at transverse reinforcement that can be predicted from drift ratio and stress at hoops relationship derived from test result becomes important as the limitation for design calculation. Moreover, smaller critical crack angle, stiffer column and higher lateral strength will be occurred from higher axial load application. Current codes provisions in shear strength provide the conservative estimation as 45 degrees of crack angle applied. On the other hand, models proposed by researchers overestimate the measured strength.
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MENDLOVÁ, Olga. "Redcord na vozíku." Master's thesis, 2015. http://www.nusl.cz/ntk/nusl-187931.
Повний текст джерелаАнотація:
Diploma thesis deals with a suspension system of cords and slings called Redcord. Redcord helps physiotherapists as their auxiliary third hand. Redcord has a wide range of application. The main goal of the thesis is to develop and test training units in Redcord for spinal patients on a wheelchair in the Rehabilitation Institute Kladruby. This goal was successfully realized and the group exercise in Redcord were implemented between the procedures of the rehabilitation program. The study also discusses the effectiveness of exercise in Redcord, the evaluation of different dosage of load and monitoring the progression of a group training. The group exercise in Redcord for spinal patients on a wheelchair is effective, because it allows the same exercise training for patients with different level of spinal cord lesion and different stability of the trunk. This is possible thanks to the various dosage of load in Redcord. The feedback from spinal patients has been verified by subjective evaluation in the form of a questionnaire supplemented with a interview.