An arginine (R) to a glycine (G) mutation at position 145 in the highly reserved inhibitory domain of cardiac troponin I (cTnI) is associated with hypertrophic cardiomyopathy (HCM), an autosomal dominant disease characterized by left ventricular hypertrophy. An arginine (R) to tryptophan (W) mutation at the same position in cTnI is associated with restrictive cardiomyopathy (RCM), a disease characterized by diastolic dysfunction with normal left ventricular size and normal systolic function. In this study we addressed the functional consequences of the human cardiac troponin I (hcTnI) HCM R145G mutation and hcTnI RCM R145W mutation in transgenic mice. Simultaneous measurements of the ATPase activity and force in skinned papillary fibers from hcTnI R145G transgenic mice (Tg-R145G) versus hcTnI wild type transgenic mice (Tg-WT) showed a significant decrease in the maximal Ca2+ activated force without changes in the maximal ATPase activity and an increase in the Ca2+ sensitivity by both ATPase activity and force development. No difference in the cross-bridge turnover rate was observed at the same level of cross-bridge attachment (activation state) showing that changes in Ca2+ sensitivity were not due to changes in cross-bridge kinetics. Energy cost calculations demonstrated higher energy consumption in Tg-R145G fibers compared to Tg-WT fibers. The addition of 3mM BDM at pCa 9.0 showed that there was approximately 2~4 percent of force generating cross-bridges attached in Tg-R145G fibers compared to less than 1.0 percent in Tg-WT fibers, suggesting the mutation impairs the ability of the cardiac troponin complex to fully inhibit cross-bridge attachment under relaxing conditions. Prolonged force and intracellular [Ca2+] transients in electrically stimulated intact papillary muscles were observed in Tg-R145G compared to Tg-WT. These results suggest that the phenotype of HCM is most likely caused by the compensatory mechanisms in the cardiovascular system which are activated by: 1) higher energy cost in the heart resulting from a significant decrease in average force per cross-bridge; 2) incomplete relaxation (diastolic dysfunction) caused by prolonged [Ca2+] and force transients; and 3) an inability of the cardiac TnI to completely inhibit activation at low levels of diastolic Ca2+ in Tg-R145G. Simultaneous measurements of the ATPase activity and force in transgenic skinned papillary fibers from hcTnI R145W transgenic mice (Tg-R145W) versus Tg-WT showed that there was a ~13 to ~16 percent increase in the maximal Ca2+ activated force and ATPase activity, respectively. The rate of dissociation of force generating cross-bridges (g) and energy cost (ATPase/force) was the same in all groups of fibers. These results suggest that the increase in force and ATPase activity is associated with an increase in the number of force generating cross-bridges attached at all activation levels. Additionally, there was a large increase in the Ca2+ sensitivity of force development and ATPase activity. In intact fibers, the mutation caused prolonged force and intracellular [Ca2+] transients, as expected due to the increased Ca2+ sensitivity (slower dissociation rate of Ca2+ from cTnC). The above cited results suggest that: 1) there would be an increase in resistance to ventricular filling during diastole resulting from the prolonged force and Ca2+ transients, especially at high heart rates; 2) there would be a decrease in ventricular filling (diastolic dysfunction); and 3) an increase in contractility during systole that would off-set the negative effect of a decrease in diastolic filling on ventricle stroke volume thus allowing the heart to maintain normal stroke volume despite the compromise in RCM (Tg-R145W) heart.

<p>Vilket arbetssätt har den svenska styrkan i Afghanistan, specifikt i PRT Mazar-e-Sharif, i förhållande till arbetsmetoderna minimum force och show of force? Har det skett någon förändring i arbetssättet mellan 2006/07 och 2009/10? Vad kan en eventuell förändring bero på och kan man se någon inriktning för framtiden? Genom en jämförande fallstudie skall uppsatsen analysera hur den svenska styrkan i Afghanistan förhöll sig till arbetssätten minimum force och show of force vid två olika tidsperioder. Genom att analysera två tidsperioder kan man komma fram till om en förändring i arbetssätt skett samt undersöka anledningarna till den. Resultatet av analysen visar att under åren 2006/07 arbetade svenskarna i mångt och mycket efter metoden minimum force genom användandet av lätta fordon och små patruller. Under 2009/10 har dock en förskjutning mot arbetssättet show of force upptäckts genom införandet av tyngre fordon och fler vapensystem. Anledningarna beror på en förändrad taktik samt utökat samarbete med afghanskastyrkor vilket ökar hot- och risknivån och således ställer större krav på tyngre materiel med mer skydd och eldkraft. Framtiden visar inte på någon tillbakagång mot den brittiska metoden minimumforce.</p> / <p>Which approach does the Swedish force in Afghanistan, especially in the PRT Mazar-e-Sharif, use in relation to the methods minimum force and show of force? Has there been any change in approach between 2006/07 and 2009/10? What are the motives for an eventual change and can you see some indications in the future?Through a comparative case study the essay will analyze how the Swedish forces in Afghanistan worked in relation to the two approaches minimum force and show of force at two different time periods. By analyzing two time periods an eventual change in approach can be obtained and motives for it can be investigated. The results of the analysis show that during the years 2006/07 Swedish forces, in many aspects, used the method minimum force through the use of light vehicles and small patrols. During 2009/10, however, a shift in approach towards show of force is detected through the introduction of heavier vehicles and more weapons system. Motives for a change are believed to be in tactics and enhanced cooperation with Afghan forces, which increases the threat and risk level and thus increases the demands on heavier equipment with more protection and firepower. The future does not show any decline against the British method of minimum force.</p>

Vilket arbetssätt har den svenska styrkan i Afghanistan, specifikt i PRT Mazar-e-Sharif, i förhållande till arbetsmetoderna minimum force och show of force? Har det skett någon förändring i arbetssättet mellan 2006/07 och 2009/10? Vad kan en eventuell förändring bero på och kan man se någon inriktning för framtiden? Genom en jämförande fallstudie skall uppsatsen analysera hur den svenska styrkan i Afghanistan förhöll sig till arbetssätten minimum force och show of force vid två olika tidsperioder. Genom att analysera två tidsperioder kan man komma fram till om en förändring i arbetssätt skett samt undersöka anledningarna till den. Resultatet av analysen visar att under åren 2006/07 arbetade svenskarna i mångt och mycket efter metoden minimum force genom användandet av lätta fordon och små patruller. Under 2009/10 har dock en förskjutning mot arbetssättet show of force upptäckts genom införandet av tyngre fordon och fler vapensystem. Anledningarna beror på en förändrad taktik samt utökat samarbete med afghanskastyrkor vilket ökar hot- och risknivån och således ställer större krav på tyngre materiel med mer skydd och eldkraft. Framtiden visar inte på någon tillbakagång mot den brittiska metoden minimumforce. / Which approach does the Swedish force in Afghanistan, especially in the PRT Mazar-e-Sharif, use in relation to the methods minimum force and show of force? Has there been any change in approach between 2006/07 and 2009/10? What are the motives for an eventual change and can you see some indications in the future?Through a comparative case study the essay will analyze how the Swedish forces in Afghanistan worked in relation to the two approaches minimum force and show of force at two different time periods. By analyzing two time periods an eventual change in approach can be obtained and motives for it can be investigated. The results of the analysis show that during the years 2006/07 Swedish forces, in many aspects, used the method minimum force through the use of light vehicles and small patrols. During 2009/10, however, a shift in approach towards show of force is detected through the introduction of heavier vehicles and more weapons system. Motives for a change are believed to be in tactics and enhanced cooperation with Afghan forces, which increases the threat and risk level and thus increases the demands on heavier equipment with more protection and firepower. The future does not show any decline against the British method of minimum force.

This thesis presents results from experimental and numerical investigations of the hydrodynamic forces on a rigid cylinder moving with prescribed orbits in uniform flow. The hydrodynamic forces are measured in both in-line (IL) and cross- ow (CF) directions. The measurements are processed to nd excitation and added mass coeffcients at discrete frequencies. The numerical simulations are used to illustrate the vortex shedding modes and are compared with the experimental results. The hydrodynamic coeffcients obtained from the harmonic forced motion experiments of a rigid cylinder do not always represent forces on a cross section of a exible beam. The orbits used in the forced motion experiments are therefore extracted from the measured motions of cross sections of a exible pipe under uniform and shear flows. Both periodic and observed orbits within a time window are applied as prescribed motions. Higher order displacement components are present in such orbits. IL response amplitudes from combined IL and CF response are larger than pure IL response amplitudes. The hydrodynamic coefficients obtained from the periodic experiments are often larger than those obtained from the pure IL tests. Higher order displacement components are more common in the IL direction than in the CF direction, and higher order IL displacement components will cause larger hydrodynamic forces in both directions. The hydrodynamic coefficients obtained from periodic motion tests are adequate for representing quasi-periodic observed motions. For chaotic observed motions, periodic orbits will yield hydrodynamic coefficients with larger uncertainties. Results from numerical analyses using large eddy simulation (LES) indicate that this method can be used to identify vortex shedding patterns and predict hydrodynamic forces under certain Re numbers and orbits.

The purpose of this study was to characterize the micromechanical properties of various structural components in asphalt using Atomic Force Microscopy (AFM). The focus of the study was based on nano-indentation experiments performed within a micro-grid of asphalt phases in order to determine micromechanical properties such as stiffness, adhesion and elastic/plastic behavior. The change in microstructure and micromechanical behavior due to oxidative aging of the asphalt was also a primary focus of the study. The experiment was performed with careful consideration of AFM artifacts, which can occur due to factors such as geometry of the cantilever tip, hysteresis, filtering methods and acoustic vibrations. The materials used in this study included asphalts AAB, AAD and ABD from the Materials Reference Library (MRL) of the Strategic Highway Research Program (SHRP), chosen due to variations in crude source, chemical composition and elemental analysis for each asphalt type. The analysis of nano-indentation creep measurements corresponding to phase-separated regions ultimately revealed heterogeneous domains in asphalt with different mechanical properties, and oxidative aging was found to induce substantial microstructural change within these domains, including variations in phase structure, phase properties and phase distribution. The form and extent of these changes, however, were different for each asphalt studied. Data analysis and information collected during this study were used for comparisons to existing models and asphalt data, which validated results and established correlations to earlier, related studies. From these comparisons, it was found that data parallels followed expected trends; furthermore, analogous interpretations and distinctions were made between results from this study and the micellar and microstructural models of asphalt. This study of micromechanical properties that govern asphalt behavior has yielded information essential to the advancement of hot mix asphalt (HMA) performance, including a new asphalt “weak zone” hypothesis and a foundation of data for implementation into new and existing asphalt models.

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Because the need of high speed data transmission is increasing day by day, fiber optic communication have played an important role. However, with increasing of the data transmission distance, the loss of the power is a series problem. To solve this problem, the power of the signal must be amplified in a fixed distance to keep the signal reality. In the optic amplified system, the pump laser is always a 980nm high-power laser. Because of the high aspect ratio of this laser, the quadrangular- pyramid-shaped fiber endface(QPSFE) lensed fiber is needed in order to increase the coupling efficiency. There is no standard process to fabricate QPSFE now. The experiment method is as follow. The first procedure is to polish the flat-end fiber to become the QPSFE, then melt the fiber by electric arc, the QPSFE lensed fiber is formed finally. In the polishing step, the bare fiber polishing machine is used. But, the polished quantity is unavailable during polishing, so the yield of the well-polished fibers is poor, only 20%. In this research, the force sensing mechanism mounted in the polishing machine is proposed to measure the force between the fiber and the polish disk. By mounting the mechanism, there are several advantages, such as operating conveniently, increasing the polishing speed, and making the polished quantity available during polishing. Using this force sensing mechanism to develop a polish rule will improve the yield of the well-polished fibers. The strain gauge method is used to design the force sensing mechanism. Using this mechanism and taking the force analysis of the fiber polishing will make the force information between the fiber and the polish disk available. By design the parameters of this mechanism advisably, it will reach the expected purpose in this research. A 0.5

In the control of the vibration structure, active vibration control is an important topic during these years. In this thesis, an active vibration control strategy is proposed to improve the vibration problem in a linear motor positioning system. The main purpose of the present research is to reduce the vibration of the positioning system. A force estimator is applied to suppress extra force produced from a linear motor positioning system. However, uncertain parameters of the system and external disturbance degrade the accuracy of the force estimator. A sliding controller has been designed to enhance the performance of the control system. The performance of the force estimator and the improvement of the control strategy have been discussed thoroughly in this research. The computer simulation and experiments both show encouraging results of the proposed control strategy. The vibration induced from a linear motor positioning system can be suppressed to the expected amplitude 0.0956 when the linear motor position completed.

Rotor-bearing system characteristics, such as natural frequencies, mode shapes, stiffness and damping coefficients, are essential to diagnose and correct vibration problems during system operation. Of the above characteristics, accurate identification of bearing force parameters, i.e. stiffness and damping coefficients, is one of the most difficult to achieve. Field identification by imbalance response measurements is a simple and often reliable way to determine synchronous speed force coefficients. An enhanced method to estimate bearing support force coefficients in flexible rotor-bearing systems is detailed. The estimation is carried out from measurements obtained near bearing locations from two linearly independent imbalance tests. An earlier approach assumed rotordynamic measurements at the bearing locations, which is very difficult to realize in practice. The enhanced method relaxes this constraint and develops the procedure to estimate bearing coefficients from measurements near the bearing locations. An application of the method is presented for a test rotor mounted on two-lobe hydrodynamic bearings. Imbalance response measurements for various imbalance magnitudes are obtained near bearing locations and also at rotor mid-span. At shaft speeds around the bending critical speed, the displacements at the rotor mid-span are an order of magnitude larger than the shaft displacements at the bearing locations. The enhanced identification procedure renders satisfactory force coefficients in the rotational speed range between 1,000 rpm and 4,000 rpm. The amount of imbalance mass needed to conduct the tests and to obtain reliable shaft displacement measurements influences slightly the magnitude of the identified force coefficients. The effect of increasing the number of rotor sub-elements in the finite-element modeling of the shaft is noted. Sensitivity of the method and derived parameters to noise in the measurements is also quantified.

Thèse de doctorat : Physique : Strasbourg 1 : 2007. / Titre provenant de l'écran-titre. Bibliogr. p. 141-146.