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This study is aimed to evaluate the compatibility of single-cone filling technique in reciprocal and rotationally formed canals in using Micro-CT (Micro-computed tomography). The samples were split into two groups according to the kinematics system used. In both groups, one canal of the shaped roots was filled with the lateral compaction and the other one with a matched single-cone technique with a bioceramic root canal sealer, BioRoot RCS. The percentage of voids in the canal were evaluated by micro-CT radiograph before and after obturation. Regardless of the kinematics used, the single-cone technique left significantly fewer voids than the lateral compaction. In the kinematics comparison, the group shaped with the reciprocal system and filled with the single-cone system had the best results. The reciprocal nickel-titanium (NiTi) system with a matching single-cone gutta percha filling technique was found to be more effective in terms of reducing voids in root canal filling., Este estudio evaluó la compatibilidad de la técnica de obturación de cono único mediante el uso de Micro-CT (microtomografía computarizada). Las muestras se dividieron en dos grupos según el sistema rotatorio utilizado. En ambos grupos, el conducto se obturó con compactación lateral y el otro con una técnica de cono único combinada con el cemento biocerámico BioRoot RCS. El porcentaje de espacios vacíos en el conducto se evaluó mediante micro-CT antes y después de la obturación. Independientemente de la cinemática utilizada, la técnica de cono único dejó significativamente menos espacios que la compactación lateral. El grupo conformado con el sistema recíproco y obturado con el sistema de cono único obtuvo los mejores resultados. El sistema recíproco con una técnica de obturación de gutapercha de cono único es más eficaz en términos de reducir los espacios vacíos en el conducto radicular.

Microwave spectroscopy has long been the standard for sensitive and specific analysis of small organic molecules. Nearly every molecule identified in the interstellar medium was first studied on earth using microwave spectroscopy, and the technique has recently emerged as a powerful mixture analysis tool. Nearly all of this prior work was done in supersonic expansion experiments, which have cold rotational temperatures in the interaction region, but supersonic lab-frame molecule velocities, limiting total interaction time. Here, I present a variety of results using buffer gas cooled microwave spectroscopy, a different approach to achieving rotationally and translationally cold ensembles of neutral molecules. First, I demonstrate that microwave three-wave mixing, a previously demonstrated technique sensitive to molecular chirality, is also sensitive to molecules chiral only by virtue of isotope placement. Second, I discuss application of buffer-gas cooled microwave spectroscopy to the detection and characterization of gauche-isoprene, a species previously uncharacterizable in supersonic expansion techniques. The remaining chapters are dedicated to demonstration and discussion of third and fourth generation buffer gas cells for microwave spectroscopy. First, I make the most precise measurement of the energy differences between two chiral molecules ever conducted using a cryogenic tunable microwave Fabry-Perot resonator. Second, I demonstrate our ability to measure reaction rates between cold molecules, an essential piece of our understanding of interstellar chemistry. Third, I show that using the new BUGBITES technique, we can reach 880 Hz linewidths, a factor of 3 improvement over any other conventional rotational spectroscopy technique. Together, these experiments show the versatility and utility of buffer gas cells for microwave spectroscopy.

Present polo helmet testing methods only assess linear acceleration, neglecting the evaluation of a helmet's ability to reduce rotational acceleration. Both linear and rotational accelerations are key predictors of brain injuries. Therefore, understanding these measures is crucial for gauging the risk associated with each helmet. This report describes the results of a test series requested by the United States Polo Association Safety Committee that evaluated current polo helmets under rotational loading conditions.

This document details the protocol used by the Virginia Tech Helmet Ratings to rate snow sport helmets based on concussion risk.

AimsPersistent atrial fibrillation (AF) has been explained by multiple mechanisms which, while they conflict, all agree that more disorganized AF is more difficult to treat than organized AF. We hypothesized that persistent AF consists of interacting organized areas which may enlarge, shrink or coalesce, and that patients whose AF areas enlarge by ablation are more likely to respond to therapy.Methods and resultsWe mapped vectorial propagation in persistent AF using wavefront fields (WFF), constructed from raw unipolar electrograms at 64-pole basket catheters, during ablation until termination (Group 1, N = 20 patients) or cardioversion (Group 2, N = 20 patients). Wavefront field mapping of patients (age 61.1 ± 13.2 years, left atrium 47.1 ± 6.9 mm) at baseline showed 4.6 ± 1.0 organized areas, each separated by disorganization. Ablation of sites that led to termination controlled larger organized area than competing sites (44.1 ± 11.1% vs. 22.4 ± 7.0%, P < 0.001). In Group 1, ablation progressively enlarged unablated areas (rising from 32.2 ± 15.7% to 44.1 ± 11.1% of mapped atrium, P < 0.0001). In Group 2, organized areas did not enlarge but contracted during ablation (23.6 ± 6.3% to 15.2 ± 5.6%, P < 0.0001).ConclusionMapping wavefront vectors in persistent AF revealed competing organized areas. Ablation that progressively enlarged remaining areas was acutely successful, and sites where ablation terminated AF were surrounded by large organized areas. Patients in whom large organized areas did not emerge during ablation did not exhibit AF termination. Further studies should define how fibrillatory activity is organized within such areas and whether this approach can guide ablation.

Sensors that provide critical information about jet engine performance are widely installed on static components but are rarely found on rotors because of their inaccessibility and extremely high rotation speeds. We present a new monitoring method, integrating energy harvesting technology with wireless sensors to achieve real-time self-powered engine monitoring. Energy harvesters, used to generate power from ambient vibration, are sustainable alternatives to batteries for achieving self-sustained long-term operation of electronic devices. By utilising structural nonlinearity, force amplification mechanism, and the piezoelectric effect, we show a 22.52-g energy harvester capable of high power output (78.87 mW), broad working bandwidth (22.5 Hz), and strong reliability (2100 RPM). Our approach breaks limitations from wired connections that are weighty and vulnerable to failures. We theoretically and experimentally analyse the nonlinear responses and demonstrate the harvester by constantly lighting 112 LEDs and a self-powered wireless sensor system in a jet engine. This work paves a new way for developing future monitoring systems for advanced jet engines and other rotating machinery applications. © 2020 Elsevier Ltd

When football originated in the 1800s, players wore no protective equipment. Between 1869 and 1905, there were 18 deaths and 159 serious injuries attributed to the sport. Following this, players began to wear protective equipment. The first use of a football helmet was in 1893, made of leather and designed to reduce the risk of skull fracture. Initially, football helmets were intended to protect a player against the most severe hits they would experience on the field. More recently, it has been shown that mild traumatic brain injuries, such as concussions, can induce long-term neurodegenerative processes. Since their introduction, helmets have transformed into plastic shells with padding designed to mitigate accelerations on the brain. With the growing concern for player safety, regulating bodies, like the National Operating Committee on Standards for Athletic Equipment, have implemented standards for protective equipment, including football helmets. On top of these standards, there have been multiple methods developed to assess helmet performance with different testing apparatuses. Manufacturers are interested in how their helmet performs according to multiple testing methods. This could be costly if they do not have the proper testing equipment that a protocol utilizes. This thesis assesses the interchangeability of different test equipment to reproduce a testing protocol. The desire to perform well in testing standards has driven the improvement of helmet performance and continued design innovation. The second aim of this thesis is to evaluate helmet performance and its relationship with design changes in football helmets manufactured between 1980 and 2018.

Recently many interests have been shown to study the rotational motion of molecules in solids of alkali halide crystals doped with polar impurities which shows pronounced effects on optical, thermal and electrical properties of the host crystals, playing a dominant role in science and technology. A free molecule containing N atoms has 3N-6 degree of vibrational freedom, three degree of translational freedom and three degrees of rotational freedom. When a molecule is introduced substitutionally into a lattice, the vibrational degrees of freedom are usually changed relatively small by the matrix. The translational degrees of freedom of the molecules are the same as the translational degrees of freedom of an impurity atom, i.e., they manifest themselves as impurity modes. We have considered the third group of degree of freedom, those connected with the rotational inertia of the molecule. Low temperature infra-red absorption, thermal conductivity and specific heat measurements have shown a better agreement with the theoretical one by optical spectroscopy method on Devonshire model. This model explains gross features of the IR data except the tunneling translations which were not observed in optical measurements that have been discussed in details. By means of infrared-absorption, thermal-conductivity, and specific-heat measurements at low temperatures, the problem of rotational motion of molecules in solids has been studied using CN− ions substituted for the halogen in KCl, KBr, KI, RbCl, NaCl, and NaBr. Energy levels associated with the ion performing free rotation, hindered rotation, oscillation, and tunneling motion were observed. It was found that a simple 3-dimensional potential for a linear diatomic molecule developed by Devonshire based on a 2-dimensional cosine potential first proposed by Pauling explained all of our observations. For the potassium halides the barrier height is 0.003 eV; in RbCl it is 0.0075 eV, and in the sodium halides it is >0.015 eV. Stre

This thesis provides a standardized method to measure accuracy for engine and gearbox sensors. Accuracy is defined by ISO 5725, which states that trueness and precision need to be known to provide a metric for accuracy. However, obtaining and processing the data required for this is not straight forward. In this thesis, a method is presented that consists of two main parts: data acquisition and data analysis. The data acquisition part shows how to connect all of the equipment used and how to sample and store all the raw data from the sensors. The data analysis part shows how to process that raw data into statistical data, such as trueness, repeatability and reproducibility for the sensors. Once repeatability and reproducibility are known, the total precision can be determined. Accuracy can then be obtained by using information from trueness and precision. Besides, this thesis shows that measurement error can be separated into error caused by the sensors and error caused by the measurand. This is useful information, because it can be used to assess which type of error is the greatest, whether or not it can be compensated for, and if it is economically viable to compensate for such error. The results are then shown, where it is possible to gain information about the sensors’ performance from various graphs. Between Hall and inductive sensors, there were no superior winner, since they both have their strengths and weaknesses. The thesis ends by making recommendations on how to compensate for some of the errors, and how to improve upon the method to make it more automatic in the future.

Introduction. Traumatic brain injuries, including sports-related concussions, are a major public health concern. Although participation in sport brings with it many benefits, the potential risk of sustaining adverse injuries such as sports-related concussion is an escalating societal and ethical issue. The onset of short-lived impairment of central nervous system dysfunction in concussed athletes following a sport-related concussion can lead to complications if the condition is not recognised and removed from participation in sport in a timely manner. Rationale and Study aims. This series of studies aim to understand the nature and magnitude of head biomechanics, short-lived impairment of central nervous system (CNS) function, and clinical signs and symptoms associated with concussions and repetitive head impacts. More specifically, it is hypothesised that (i) the biomechanics of repetitive head impacts in amateur boxers, (ii) endorsement of symptoms, and performance on cognition and balance component scores immediately post-contest and, (iii) a decline in function on the King-Devick test, will be worse for boxers clinically classified with a concussion, be associated with high-risk for CNS injury circumstances, and be reflective of exposure to repetitive head impacts through exposure to repeat contests in the tournament. Method. Healthy male collegiate students (n = 376) between the ages of 18-34 years (M = 20.97, SD = 2.30) consented to participate in the Notre Dame Bengal Bouts amateur boxing tournament in 2012 and/or 2013. Boxers completed the Sports Concussion Assessment tool, Cogstate Brief Battery, and the King-Devick test prior to participation in any sparring and following each of the four elimination contests. A sample of boxers were also instrumented with X2 Biosystems headbands to monitor exposure to impacts during contests. Results. The results of this study support the hypothesis that in amateur boxers the number of head impacts, and the acceleration o

When football originated in the 1800s, players wore no protective equipment. Between 1869 and 1905, there were 18 deaths and 159 serious injuries attributed to the sport. Following this, players began to wear protective equipment. The first use of a football helmet was in 1893, made of leather and designed to reduce the risk of skull fracture. Initially, football helmets were intended to protect a player against the most severe hits they would experience on the field. More recently, it has been shown that mild traumatic brain injuries, such as concussions, can induce long-term neurodegenerative processes. Since their introduction, helmets have transformed into plastic shells with padding designed to mitigate accelerations on the brain. With the growing concern for player safety, regulating bodies, like the National Operating Committee on Standards for Athletic Equipment, have implemented standards for protective equipment, including football helmets. On top of these standards, there have been multiple methods developed to assess helmet performance with different testing apparatuses. Manufacturers are interested in how their helmet performs according to multiple testing methods. This could be costly if they do not have the proper testing equipment that a protocol utilizes. This thesis assesses the interchangeability of different test equipment to reproduce a testing protocol. The desire to perform well in testing standards has driven the improvement of helmet performance and continued design innovation. The second aim of this thesis is to evaluate helmet performance and its relationship with design changes in football helmets manufactured between 1980 and 2018.

This thesis provides a standardized method to measure accuracy for engine and gearbox sensors. Accuracy is defined by ISO 5725, which states that trueness and precision need to be known to provide a metric for accuracy. However, obtaining and processing the data required for this is not straight forward. In this thesis, a method is presented that consists of two main parts: data acquisition and data analysis. The data acquisition part shows how to connect all of the equipment used and how to sample and store all the raw data from the sensors. The data analysis part shows how to process that raw data into statistical data, such as trueness, repeatability and reproducibility for the sensors. Once repeatability and reproducibility are known, the total precision can be determined. Accuracy can then be obtained by using information from trueness and precision. Besides, this thesis shows that measurement error can be separated into error caused by the sensors and error caused by the measurand. This is useful information, because it can be used to assess which type of error is the greatest, whether or not it can be compensated for, and if it is economically viable to compensate for such error. The results are then shown, where it is possible to gain information about the sensors’ performance from various graphs. Between Hall and inductive sensors, there were no superior winner, since they both have their strengths and weaknesses. The thesis ends by making recommendations on how to compensate for some of the errors, and how to improve upon the method to make it more automatic in the future.

Recently many interests have been shown to study the rotational motion of molecules in solids of alkali halide crystals doped with polar impurities which shows pronounced effects on optical, thermal and electrical properties of the host crystals, playing a dominant role in science and technology. A free molecule containing N atoms has 3N-6 degree of vibrational freedom, three degree of translational freedom and three degrees of rotational freedom. When a molecule is introduced substitutionally into a lattice, the vibrational degrees of freedom are usually changed relatively small by the matrix. The translational degrees of freedom of the molecules are the same as the translational degrees of freedom of an impurity atom, i.e., they manifest themselves as impurity modes. We have considered the third group of degree of freedom, those connected with the rotational inertia of the molecule. Low temperature infra-red absorption, thermal conductivity and specific heat measurements have shown a better agreement with the theoretical one by optical spectroscopy method on Devonshire model. This model explains gross features of the IR data except the tunneling translations which were not observed in optical measurements that have been discussed in details. By means of infrared-absorption, thermal-conductivity, and specific-heat measurements at low temperatures, the problem of rotational motion of molecules in solids has been studied using CN− ions substituted for the halogen in KCl, KBr, KI, RbCl, NaCl, and NaBr. Energy levels associated with the ion performing free rotation, hindered rotation, oscillation, and tunneling motion were observed. It was found that a simple 3-dimensional potential for a linear diatomic molecule developed by Devonshire based on a 2-dimensional cosine potential first proposed by Pauling explained all of our observations. For the potassium halides the barrier height is 0.003 eV; in RbCl it is 0.0075 eV, and in the sodium halides it is >0.015 eV. Stre

Capsule network (CapsNet) is a new and promising approach to computer vision. In the small amount of research published so far, it has shown to be good at generalizing complex objects and perform well even when the images are skewed or the objects are seen from unfamiliar viewpoints. This thesis further tests this ability of CapsNetby comparing it to convolutional networks (ConvNets) on the task to understand images of clothing in different rotational views. Even though the ConvNets have a higher classification accuracy than CapsNets, the results indicate that CapsNets are better at understanding the clothes when viewed in different rotational views., Capsule network (CapsNet) är en ny typ av neuralt nätverk för datorseende, som framförallt presterar bra även då bilderna är förvrängda eller sedda från obekanta vinklar. Den här uppsatsen testar CapsNets förmåga att förstå klädesobjekt sedda ur olika synviklar genom att göra en jämförelse med ConvNets. Resultaten visar att, trots att ConvNets har en högre exakthet i sin klassificering, är CapsNets bättre på att förstå kläderna sedda från olika synvinklar.

More than 19 million children participate in youth baseball and softball annually. Although baseball and softball are not commonly depicted as contact sports in the, according to the U.S. CPSC baseball and softball were responsible for 11.6% of all head injuries treated in emergency rooms in 2009; third most behind only cycling and football. Ball impact has been identified as the leading cause of injury in baseball and softball, with the most frequent injury resulting from a ball impacting the head. Reduced injury factor balls, infield softball masks, batter's helmets, and catcher's masks have all been integrated into baseball and softball as a means for preventing serious head injury from ball impact. The research in this thesis had four objectives: to compare the responses of the Hybrid III and NOCSAE headforms during high velocity projectile impacts, to compare head injury risk across a range of baseball stiffness designed for different age groups, to evaluate the effectiveness of infielder softball masks' ability to attenuate facial fracture risk, and to describe a novel methodology to evaluate the performance of batter's helmets and catcher's masks. Results of these research objectives determined the most suitable ATD headform to evaluate head injury risk for high velocity projectile impacts, provided a framework for determining the optimal age-specific ball stiffness and optimal infield mask design, and disseminated STAR ratings for batter's helmets and catcher's masks to the public. The research presented in this thesis can be used to further improve safety in baseball and softball.

Capsule network (CapsNet) is a new and promising approach to computer vision. In the small amount of research published so far, it has shown to be good at generalizing complex objects and perform well even when the images are skewed or the objects are seen from unfamiliar viewpoints. This thesis further tests this ability of CapsNetby comparing it to convolutional networks (ConvNets) on the task to understand images of clothing in different rotational views. Even though the ConvNets have a higher classification accuracy than CapsNets, the results indicate that CapsNets are better at understanding the clothes when viewed in different rotational views., Capsule network (CapsNet) är en ny typ av neuralt nätverk för datorseende, som framförallt presterar bra även då bilderna är förvrängda eller sedda från obekanta vinklar. Den här uppsatsen testar CapsNets förmåga att förstå klädesobjekt sedda ur olika synviklar genom att göra en jämförelse med ConvNets. Resultaten visar att, trots att ConvNets har en högre exakthet i sin klassificering, är CapsNets bättre på att förstå kläderna sedda från olika synvinklar.

Fit is often pointed to as the most important factor to consider when selecting a helmet. However, there is no published biomechanical evidence suggesting that of helmet fit effects concussion risk. The objectives of this study were to quantify helmet fit on a headform and to determine the effect fit has on helmet performance. An impact pendulum was used to strike a helmeted NOCSAE headform mounted on a Hybrid III neck. Helmets were impacted at 4 locations at 3 energies representing a range of concussive to sub-concussive impacts. The fit conditions evaluated in this study represent fitting scenarios in which an athlete is provided a helmet that is properly or improperly sized and cases in which a properly sized helmet is too loose, too tight, or properly adjusted. A custom pressure sensor was developed and used to characterize helmet fit in each condition with a quantitative fit metric representative of a variation from zero pressure on the headform. All helmets produced significant differences in both peak linear and peak angular acceleration due to fit. Differences were generally small with some exceptions. Furthermore, air bladder inflation generated significant differences in both peak linear and peak angular acceleration, but these were generally small in magnitude. While fit associated with size and air bladder inflation significantly affected linear and rotational head acceleration for most impact conditions, the best fit condition did not always generate the lowest accelerations. Differences can be attributed to varying helmet characteristics between and within helmet models.

In this paper, for the first time, the nonlinear motion characteristics of a hinged-hinged third-order shear deformable microbeam are examined, based on the modified couple stress theory and the third-order shear deformation theory. The extensibility of the microbeam is modelled by taking into account the longitudinal displacement. The nonlinear equations governing the longitudinal, transverse, and rotational motions are derived by means of Hamilton's principle in conjunction with the modified couple stress theory (to take into account small-scale effects). The three coupled nonlinear partial differential equations are discretized via the Galerkin method and the resulting set of ordinary differential equations is solved by means of the pseudo-arclength continuation technique and via direct time-integration. The effects of the system parameters on the behaviour of the microbeam are studied. Results are presented in the form of frequency-responses and force-responses. Points of interest in the parameter space are also highlighted in the form of time histories, phase-plane portraits, and fast Fourier transforms (FFTs). Moreover, the similarities and differences in the response of the system obtained via the modified couple stress and classical continuum mechanics theories are discussed.

Elastic-plastic, closed-form solutions were developed recently by the author, to capture the nonlinear response of laterally loaded rigid piles. Presented in compact form, the solutions are convenient to use, and sufficiently accurate despite using only two input parameters of the net limiting force per unit length pu along the pile, and a subgrade modulus k. Nevertheless, piles may be subjected to limited cap-restraints or loading below ground surface, which alter the response remarkably.This paper provides explicit expressions for estimating loading capacity of anchored piles and develops new solutions for lateral piles with cap-rotation by stipulating a constant pu or a linear increasing pu (Gibson pu) with depth. Lateral loading capacity Ho (at the tip-yield state and yield at rotation point state) and maximum bending moment Mm (at the tip-yield state) are presented against loading locations, and in form of the lateral capacity Ho-. Mo (applied moment) locus. The capacity is consistent with available solutions for anchored piles, and caissons with either pu profile, allowing a united approach from lateral piles to anchored piles. The new solutions are also presented in charts to highlight the impact of rotational stiffness of pile-cap on nonlinear response, offering a united approach for free-head piles through fixed-head piles.Several advantages of the solutions are identified against the prevalent p-. y curve based approach. To estimate the key parameter pu, values of the resistance factor Np (=ratio of pile-soil limiting resistance over the undrained shear strength su) are deduced using the current expressions against available normalised pile capacity involving the impact of gapping (between pile and soil), pile movement mode, pile slenderness ratio, inclined loading angle (anchored piles) and batter angles (lateral piles). The Np is characterised by: (i) An increase from 5.6-8.6 to 10.14-11.6, as gapping is eliminated around lateral piles and caissons, and

In this study, the rotational resistance of a spiral-type capsule rotating inside a small intestine is investigated by in vitro experiments and analytical modeling, on which a limited literature is available. The results presented exhibit viscoelastic nature of the intestinal tissue. The significance of various spiral structures and rotating speeds is quantitatively evaluated from the propulsion point of view. Also, an analytical torque model is proposed and subsequently validated. The close match between the experimental results and numerical results from the model shows that the model is reasonably accurate to estimate the rotational resistance torque of the small intestine. Both the experimental and modeling works provide a useful guide to determine the torque required for a spiral-type endoscopic capsule operating in a 'really' small intestine. Therefore, the proposed torque model can be used in the design and optimization of in-body robotic systems, which can remotely be articulated using magnetic actuation.

In this study, the rotational resistance of a spiral-type capsule rotating inside a small intestine is investigated by in vitro experiments and analytical modeling, on which a limited literature is available. The results presented exhibit viscoelastic nature of the intestinal tissue. The significance of various spiral structures and rotating speeds is quantitatively evaluated from the propulsion point of view. Also, an analytical torque model is proposed and subsequently validated. The close match between the experimental results and numerical results from the model shows that the model is reasonably accurate to estimate the rotational resistance torque of the small intestine. Both the experimental and modeling works provide a useful guide to determine the torque required for a spiral-type endoscopic capsule operating in a 'really' small intestine. Therefore, the proposed torque model can be used in the design and optimization of in-body robotic systems, which can remotely be articulated using magnetic actuation.

The aim of the present investigation was to examine the critical vortex-induced vibration (VIV) point for cylinders in a rotational system. For translational systems, the existence of a critical mass ratio for cylinders undergoing vortex-induced vibration has been well established. At mass ratios below this critical point, the reduced velocity at VIV lock-out tends to infinity, resulting in the resonance forever condition as described by the authors first reporting this phenomenon. The approach adopted in the present investigation involved measuring the VIV response of a positively buoyant pivoted cylinder being towed at very high reduced velocity. High reduced velocity was attained by establishing a very low system natural frequency. The key finding of this study is the presence of a critical point with a value similar to that of the critical mass ratio in translational systems. This critical point appears to be governed by the force moment ratio rather than the mass moment of inertia ratio. In the present study, a critical force moment ratio of 0.512 ± 0.002 was determined as the onset point for the infinite VIV lock-in regime.

In this study, the rotational resistance of a spiral-type capsule rotating inside a small intestine is investigated by in vitro experiments and analytical modeling, on which a limited literature is available. The results presented exhibit viscoelastic nature of the intestinal tissue. The significance of various spiral structures and rotating speeds is quantitatively evaluated from the propulsion point of view. Also, an analytical torque model is proposed and subsequently validated. The close match between the experimental results and numerical results from the model shows that the model is reasonably accurate to estimate the rotational resistance torque of the small intestine. Both the experimental and modeling works provide a useful guide to determine the torque required for a spiral-type endoscopic capsule operating in a 'really' small intestine. Therefore, the proposed torque model can be used in the design and optimization of in-body robotic systems, which can remotely be articulated using magnetic actuation.

The aim of the present investigation was to examine the critical vortex-induced vibration (VIV) point for cylinders in a rotational system. For translational systems, the existence of a critical mass ratio for cylinders undergoing vortex-induced vibration has been well established. At mass ratios below this critical point, the reduced velocity at VIV lock-out tends to infinity, resulting in the resonance forever condition as described by the authors first reporting this phenomenon. The approach adopted in the present investigation involved measuring the VIV response of a positively buoyant pivoted cylinder being towed at very high reduced velocity. High reduced velocity was attained by establishing a very low system natural frequency. The key finding of this study is the presence of a critical point with a value similar to that of the critical mass ratio in translational systems. This critical point appears to be governed by the force moment ratio rather than the mass moment of inertia ratio. In the present study, a critical force moment ratio of 0.512 ± 0.002 was determined as the onset point for the infinite VIV lock-in regime.

The aim of the present investigation was to examine the critical vortex-induced vibration (VIV) point for cylinders in a rotational system. For translational systems, the existence of a critical mass ratio for cylinders undergoing vortex-induced vibration has been well established. At mass ratios below this critical point, the reduced velocity at VIV lock-out tends to infinity, resulting in the resonance forever condition as described by the authors first reporting this phenomenon. The approach adopted in the present investigation involved measuring the VIV response of a positively buoyant pivoted cylinder being towed at very high reduced velocity. High reduced velocity was attained by establishing a very low system natural frequency. The key finding of this study is the presence of a critical point with a value similar to that of the critical mass ratio in translational systems. This critical point appears to be governed by the force moment ratio rather than the mass moment of inertia ratio. In the present study, a critical force moment ratio of 0.512 ± 0.002 was determined as the onset point for the infinite VIV lock-in regime.

In this study, the rotational resistance of a spiral-type capsule rotating inside a small intestine is investigated by in vitro experiments and analytical modeling, on which a limited literature is available. The results presented exhibit viscoelastic nature of the intestinal tissue. The significance of various spiral structures and rotating speeds is quantitatively evaluated from the propulsion point of view. Also, an analytical torque model is proposed and subsequently validated. The close match between the experimental results and numerical results from the model shows that the model is reasonably accurate to estimate the rotational resistance torque of the small intestine. Both the experimental and modeling works provide a useful guide to determine the torque required for a spiral-type endoscopic capsule operating in a 'really' small intestine. Therefore, the proposed torque model can be used in the design and optimization of in-body robotic systems, which can remotely be articulated using magnetic actuation.

The impact of 3D rotational errors in patient positioning on dose delivered target volumes and critical structures in IMRT was studied. Patient rotational errors ranging from -30 to +30 was introduced to IMRT treatment plans of pelvis, head and neck and brain treatment sites and the impact of rotational error on DVH metrics was assessed. The magnitude of impact of rotational error on the error in dose delivered to the target volume and critical structures depends on the location of the structures from plan isocentre. In studied plans, a maximum percentage difference of up to -9.8(1s=13.4) % in D95 to PTV was observed for head and neck treatments. Similarly, in Brain treatments a maximum difference of up to 24.0(1s=33.0) % in maximum dose of Optic chiasm was observed. The results suggest that failure to correct patient's rotational error results in under-dosage to target volumes and over-dosage to the critical structures in some specific treatment scenarios.

Elastic-plastic, closed-form solutions were developed recently by the author, to capture the nonlinear response of laterally loaded rigid piles. Presented in compact form, the solutions are convenient to use, and sufficiently accurate despite using only two input parameters of the net limiting force per unit length pu along the pile, and a subgrade modulus k. Nevertheless, piles may be subjected to limited cap-restraints or loading below ground surface, which alter the response remarkably.This paper provides explicit expressions for estimating loading capacity of anchored piles and develops new solutions for lateral piles with cap-rotation by stipulating a constant pu or a linear increasing pu (Gibson pu) with depth. Lateral loading capacity Ho (at the tip-yield state and yield at rotation point state) and maximum bending moment Mm (at the tip-yield state) are presented against loading locations, and in form of the lateral capacity Ho-. Mo (applied moment) locus. The capacity is consistent with available solutions for anchored piles, and caissons with either pu profile, allowing a united approach from lateral piles to anchored piles. The new solutions are also presented in charts to highlight the impact of rotational stiffness of pile-cap on nonlinear response, offering a united approach for free-head piles through fixed-head piles.Several advantages of the solutions are identified against the prevalent p-. y curve based approach. To estimate the key parameter pu, values of the resistance factor Np (=ratio of pile-soil limiting resistance over the undrained shear strength su) are deduced using the current expressions against available normalised pile capacity involving the impact of gapping (between pile and soil), pile movement mode, pile slenderness ratio, inclined loading angle (anchored piles) and batter angles (lateral piles). The Np is characterised by: (i) An increase from 5.6-8.6 to 10.14-11.6, as gapping is eliminated around lateral piles and caissons, and

The aim of the present investigation was to examine the critical vortex-induced vibration (VIV) point for cylinders in a rotational system. For translational systems, the existence of a critical mass ratio for cylinders undergoing vortex-induced vibration has been well established. At mass ratios below this critical point, the reduced velocity at VIV lock-out tends to infinity, resulting in the resonance forever condition as described by the authors first reporting this phenomenon. The approach adopted in the present investigation involved measuring the VIV response of a positively buoyant pivoted cylinder being towed at very high reduced velocity. High reduced velocity was attained by establishing a very low system natural frequency. The key finding of this study is the presence of a critical point with a value similar to that of the critical mass ratio in translational systems. This critical point appears to be governed by the force moment ratio rather than the mass moment of inertia ratio. In the present study, a critical force moment ratio of 0.512 ± 0.002 was determined as the onset point for the infinite VIV lock-in regime.

Prediction of the seismic rotational displacements of retaining wall under passive condition is an important aspect of design in earthquake prone region. In this paper, the pseudo-dynamic method is used to compute the rotational displacements of rigid retaining wall supporting cohesionless backfill under seismic loading for the passive earth pressure condition. The proposed method considers time, phase difference and effect of amplification in shear and primary waves propagating through both the backfill and the retaining wall. The influence of ground motion characteristics on rotational displacement of the wall is evaluated. Also the effects of variation of parameters like wall friction angle, soil friction angle, amplification factor, shear wave velocity, primary wave velocity, period of lateral shaking, horizontal and vertical seismic accelerations on the rotational displacements are studied. The rotational displacement of the wall increases substantially with increase in amplification of both shear and primary waves, time of input motion, period of lateral shaking and decreases with increase in soil friction angle, wall friction angle. The rotational displacements of the wall also increase when the effect of wall inertia is taken into account. Results are provided in graphical form.

Prediction of the seismic rotational displacements of retaining wall under passive condition is an important aspect of design in earthquake prone region. In this paper, the pseudo-dynamic method is used to compute the rotational displacements of rigid retaining wall supporting cohesionless backfill under seismic loading for the passive earth pressure condition. The proposed method considers time, phase difference and effect of amplification in shear and primary waves propagating through both the backfill and the retaining wall. The influence of ground motion characteristics on rotational displacement of the wall is evaluated. Also the effects of variation of parameters like wall friction angle, soil friction angle, amplification factor, shear wave velocity, primary wave velocity, period of lateral shaking, horizontal and vertical seismic accelerations on the rotational displacements are studied. The rotational displacement of the wall increases substantially with increase in amplification of both shear and primary waves, time of input motion, period of lateral shaking and decreases with increase in soil friction angle, wall friction angle. The rotational displacements of the wall also increase when the effect of wall inertia is taken into account. Results are provided in graphical form.

Prediction of the seismic rotational displacements of retaining wall under passive condition is an important aspect of design in earthquake prone region. In this paper, the pseudo-dynamic method is used to compute the rotational displacements of rigid retaining wall supporting cohesionless backfill under seismic loading for the passive earth pressure condition. The proposed method considers time, phase difference and effect of amplification in shear and primary waves propagating through both the backfill and the retaining wall. The influence of ground motion characteristics on rotational displacement of the wall is evaluated. Also the effects of variation of parameters like wall friction angle, soil friction angle, amplification factor, shear wave velocity, primary wave velocity, period of lateral shaking, horizontal and vertical seismic accelerations on the rotational displacements are studied. The rotational displacement of the wall increases substantially with increase in amplification of both shear and primary waves, time of input motion, period of lateral shaking and decreases with increase in soil friction angle, wall friction angle. The rotational displacements of the wall also increase when the effect of wall inertia is taken into account. Results are provided in graphical form.

We show hydrodynamic boundary conditions to be the inherent consequence Of the Onsager principle of minimum energy dissipation, , provided the relevant effects of the wall potential appear within a thin fluid layer next to the solid wall, denoted the Surface layer. The condition that the effect of the surface layer on the bulk hydrodynamics Must be independent of its thickness h is shown to imply a set of consistent scaling relationships' between h and the surface-layer variables/parameters. The use of the scaling relations, in conjunction with the surface-layer equations of motion derived from the Onsager principle, directly leads to the hydrodynamic boundary conditions. We demonstrate the surface-layer scaling process both physically and mathematically,, and relate the parameters of' the boundary conditions to those in the surface-layer equations of' motion. In spatial regions outside the surface layer, equivalence between the use of surface-layer dynamics and boundary conditions IS numerically demonstrated for Couette flows. As an application of the present approach, we derive the liquid-crystal hydrodynamic boundary conditions in which the rotational and translational dynamics are Coupled.

We show hydrodynamic boundary conditions to be the inherent consequence Of the Onsager principle of minimum energy dissipation, , provided the relevant effects of the wall potential appear within a thin fluid layer next to the solid wall, denoted the Surface layer. The condition that the effect of the surface layer on the bulk hydrodynamics Must be independent of its thickness h is shown to imply a set of consistent scaling relationships' between h and the surface-layer variables/parameters. The use of the scaling relations, in conjunction with the surface-layer equations of motion derived from the Onsager principle, directly leads to the hydrodynamic boundary conditions. We demonstrate the surface-layer scaling process both physically and mathematically,, and relate the parameters of' the boundary conditions to those in the surface-layer equations of' motion. In spatial regions outside the surface layer, equivalence between the use of surface-layer dynamics and boundary conditions IS numerically demonstrated for Couette flows. As an application of the present approach, we derive the liquid-crystal hydrodynamic boundary conditions in which the rotational and translational dynamics are Coupled.

Prediction of the seismic rotational displacements of retaining wall under passive condition is an important aspect of design in earthquake prone region. In this paper, the pseudo-dynamic method is used to compute the rotational displacements of rigid retaining wall supporting cohesionless backfill under seismic loading for the passive earth pressure condition. The proposed method considers time, phase difference and effect of amplification in shear and primary waves propagating through both the backfill and the retaining wall. The influence of ground motion characteristics on rotational displacement of the wall is evaluated. Also the effects of variation of parameters like wall friction angle, soil friction angle, amplification factor, shear wave velocity, primary wave velocity, period of lateral shaking, horizontal and vertical seismic accelerations on the rotational displacements are studied. The rotational displacement of the wall increases substantially with increase in amplification of both shear and primary waves, time of input motion, period of lateral shaking and decreases with increase in soil friction angle, wall friction angle. The rotational displacements of the wall also increase when the effect of wall inertia is taken into account. Results are provided in graphical form.

Prediction of the seismic rotational displacements of retaining wall under passive condition is an important aspect of design in earthquake prone region. In this paper, the pseudo-dynamic method is used to compute the rotational displacements of rigid retaining wall supporting cohesionless backfill under seismic loading for the passive earth pressure condition. The proposed method considers time, phase difference and effect of amplification in shear and primary waves propagating through both the backfill and the retaining wall. The influence of ground motion characteristics on rotational displacement of the wall is evaluated. Also the effects of variation of parameters like wall friction angle, soil friction angle, amplification factor, shear wave velocity, primary wave velocity, period of lateral shaking, horizontal and vertical seismic accelerations on the rotational displacements are studied. The rotational displacement of the wall increases substantially with increase in amplification of both shear and primary waves, time of input motion, period of lateral shaking and decreases with increase in soil friction angle, wall friction angle. The rotational displacements of the wall also increase when the effect of wall inertia is taken into account. Results are provided in graphical form.

Prediction of the seismic rotational displacements of retaining wall under passive condition is an important aspect of design in earthquake prone region. In this paper, the pseudo-dynamic method is used to compute the rotational displacements of rigid retaining wall supporting cohesionless backfill under seismic loading for the passive earth pressure condition. The proposed method considers time, phase difference and effect of amplification in shear and primary waves propagating through both the backfill and the retaining wall. The influence of ground motion characteristics on rotational displacement of the wall is evaluated. Also the effects of variation of parameters like wall friction angle, soil friction angle, amplification factor, shear wave velocity, primary wave velocity, period of lateral shaking, horizontal and vertical seismic accelerations on the rotational displacements are studied. The rotational displacement of the wall increases substantially with increase in amplification of both shear and primary waves, time of input motion, period of lateral shaking and decreases with increase in soil friction angle, wall friction angle. The rotational displacements of the wall also increase when the effect of wall inertia is taken into account. Results are provided in graphical form.

Prediction of the seismic rotational displacements of retaining wall under passive condition is an important aspect of design in earthquake prone region. In this paper, the pseudo-dynamic method is used to compute the rotational displacements of rigid retaining wall supporting cohesionless backfill under seismic loading for the passive earth pressure condition. The proposed method considers time, phase difference and effect of amplification in shear and primary waves propagating through both the backfill and the retaining wall. The influence of ground motion characteristics on rotational displacement of the wall is evaluated. Also the effects of variation of parameters like wall friction angle, soil friction angle, amplification factor, shear wave velocity, primary wave velocity, period of lateral shaking, horizontal and vertical seismic accelerations on the rotational displacements are studied. The rotational displacement of the wall increases substantially with increase in amplification of both shear and primary waves, time of input motion, period of lateral shaking and decreases with increase in soil friction angle, wall friction angle. The rotational displacements of the wall also increase when the effect of wall inertia is taken into account. Results are provided in graphical form.

English: In 2003, a number of landslides occurred in the Ntchenachena and the Chiweta Areas of the Rumphi District in Northern Malawi, and in the Livilivi/Mvai Catchments of Ntcheu District in Central Malawi. The landslide events caused significant damage to crops, farmland, livestock and infrastructure. Worse still, they caused the death of four people. The high density of landslides occurrences suggested instability of the slopes of these areas. In light of these landslides, this study set out to assess the slope stability status of the areas. The study addressed landslide mapping and classification of observed events; assessment of the causes and contributing factors; assessment of the socio-economic and environmental impacts of the events; exploration of traditional knowledge, beliefs and peoples perceptions surrounding landslides; determination of the coping strategies; and development of mitigations to landslides as geo-hazards. This study involved a landslide inventory of all observed This study involved a landslide inventory of all observed events. The physical characteristics of the terrain influencing slope instability were measured. The characteristics recorded included slope length, angles, aspect and altitude, and channel dimensions. Landslides were classified based on the type of movement, degree of stabilisation, and age, and materials involved in the movement. Soil samples were collected, using core and clod sampling methods and were tested for plastic limit, liquid limit, plasticity index, bulk density, hydraulic conductivity, aggregate stability, and particle sizes. Structural rock weaknesses were also measured. Vegetation data was collected, using the quadrant method and was analysed for average diameters at stump and breast height, canopy cover, and height. Questionnaires/surveys were used to assess local knowledge and perceptions towards landslides. A SPSS statistical package was used to analyse both social and physical data. It was found that 1, Afrikaans: In 2003 het ‘n aantal grondstortings voorgekom in die Ntchenachena en Chiweta gebiede van die Rumphi distrik in noord Malawi, en in die Livilivi/Mvai opvanggebiede van die Ntcheu distrik in sentraal Malawi. Die grondstortings het merkbare skade aan gewasse, landbougrond, lewende hawe en infrastruktuur aangerig. Erger nog, dit het die dood van vier persone veroorsaak. Die hoë digtheid van die voorkoms van grondstortings dui op die onstabiliteit van hange in hierdie gebeide aan. In die lig van hierdie grondstortings is hierdie studie daarop gerig om die stabiliteit van die hange in die gebiede te bepaal. In die studie word grondstortings gekarteer en waargenome gebeurtenisse geklassifiseer; oorsake en bydraende faktore word evalueer; sosio-ekonomiese en omgewingsimpakte van die gebeure word evalueer; tradisionele kennis, gelowe en mense se persepsies aangaande grondstortings word ondersoek; hanteringstrategieë word bepaal en versagting van grondstortings as gevare word ontwikkel. Hierdie studie sluit ‘n inventaris van alle waargenome grondstortings in. Die terrein se fisiese eienskappe wat hang onstabiliteit beïnvloed het, is gemeet. Die eienskappe wat aangeteken is, sluit in hanglengte, helling, aspekte en hoogte, en kanaal dimensies. Grondstortings is geklassifiseer op grond van die tipe beweging, die graad van stabilisering, ouderdom en die materiaal betrokke in die storting. Grondmonsters is versamel deur van kern- en kluitmonster metodes gebruik te maak en is getoets vir plastisiteitsgrens, vloeigrens, plastisiteitsindeks, bulkdigtheid, hidrouliese geleidingsvermoë, aggregaatstabiliteit en partikelgrootte. Strukturele rotsswakhede is ook gemeet. Plantegroeidata is versamel deur gebruik te maak van die kwadrant metode. Dit is ontleed vir gemiddelde deursnitte op stomp- en borshoogte, kroonbedekking en -hoogte. Vraeslyste/opnames is gebruik om plaaslike kennis en opvattings oor grondstortings te bepaal. ‘n SPSS statistiese pakket is gebruik om beide die

The subject of this thesis centers around the study of process; the process of taking a germinal concept or idea and translating it into the language of built form. In this particular case, the process can be described as binary, containing two distinct stages. The first stage consists of the process of translating a gestural idea or sketch into a language which is geometrically descriptive and consequently reproducible. The second stage of the process involves the translation of geometrical ideas into the language of construction. How can the dimensionless character of a geometrical model be expressed and accommodated architecturally?

Prediction of the seismic rotational displacements of retaining wall under passive condition is an important aspect of design in earthquake prone region. In this paper, the pseudo-dynamic method is used to compute the rotational displacements of rigid retaining wall supporting cohesionless backfill under seismic loading for the passive earth pressure condition. The proposed method considers time, phase difference and effect of amplification in shear and primary waves propagating through both the backfill and the retaining wall. The influence of ground motion characteristics on rotational displacement of the wall is evaluated. Also the effects of variation of parameters like wall friction angle, soil friction angle, amplification factor, shear wave velocity, primary wave velocity, period of lateral shaking, horizontal and vertical seismic accelerations on the rotational displacements are studied. The rotational displacement of the wall increases substantially with increase in amplification of both shear and primary waves, time of input motion, period of lateral shaking and decreases with increase in soil friction angle, wall friction angle. The rotational displacements of the wall also increase when the effect of wall inertia is taken into account. Results are provided in graphical form.

This paper reports on the performance evaluation of a dental handpiece in simulation of clinical finishing using a novel two-degrees-of-freedom (2DOF) in vitro apparatus. The instrumented apparatus consisted of a two-dimensional computer-controlled coordinate worktable carrying a dental handpiece, a piezoelectric force dynamometer, and a high-speed data acquisition and signal conditioning system for simulating the clinical operations and monitoring the dental finishing processes. The performance of the dental handpiece was experimentally evaluated with respect to rotational speed, torque, and specific finishing energy under the applied clinical finishing conditions. The results show that the rotational speeds of the dental handpiece decreased by increasing either the depth of cut or the feed rate at a constant clinically applied air pressure and water flowrate. They also decreased when increasing both the tangential and normal finishing forces. The specific finishing energy decreased with an increase in either depth of cut or feed rate, while the finishing torque increased as either the depth of cut or the feed rate was increased. Implications of these results were to provide guidance for proper applications of dental handpieces in clinical practice.

The objective was to study the effects of ethanol on coagulation and fibrinolysis in whole blood. Blood samples from healthy volunteers were analyzed before and after in-vitro addition of ethanol in order to achieve ethanol concentrations of 0, 1, 2 and 4[per mille sign], respectively (0, 22, 44 and 88 mmol/l). Coagulation and fibrinolysis were then assessed using rotational thromboelastometry. We found that increasing ethanol levels increasingly impaired coagulation as evaluated with rotational thromboelastometry, with a maximum prolongation of the clot formation time of 118% at an ethanol level of 4[per mille sign] (P < 0.000001). We also found a very strong impairment of fibrinolysis already at an ethanol level of 1[per mille sign]. This is the first study assessing the effects of ethanol on coagulation and fibrinolysis in a whole blood model. The impairment of coagulation is similar in nature to the impairment found in patients suffering from hypothermia. The impairment is at a level that may be of clinical importance (e.g. in patients suffering from trauma). The inhibition of fibrinolysis is obvious already at an ethanol level of 1[per mille sign] and it may be a contributing factor to the increased amount of coronary and cerebrovascular ischemic events after binge drinking.

A coupled-channel Schrödinger equation (CSE) model of photodissociation, which includes the effects of all interactions between the , , and and the and states, is employed to study the effects of rotation on the lowest- band oscillator strengths and predissociationlinewidths. Significant rotational dependences are found which are in excellent agreement with recent experimental results, where comparisons are possible. New extreme-ultraviolet (EUV)photoabsorption spectra of the key transition of are also presented and analyzed, revealing apredissociationlinewidth peaking near . This behavior can be reproduced only if the triplet structure of the state is included explicitly in the CSE-model calculations, with a spin-orbit constant for the diffuse level which accidentally predissociates . The complex rotational behavior of the and other bands may be an important component in the modeling of EUV transmission through nitrogen-rich planetary atmospheres.

A coupled-channel Schrödinger equation (CSE) model of photodissociation, which includes the effects of all interactions between the , , and and the and states, is employed to study the effects of rotation on the lowest- band oscillator strengths and predissociationlinewidths. Significant rotational dependences are found which are in excellent agreement with recent experimental results, where comparisons are possible. New extreme-ultraviolet (EUV)photoabsorption spectra of the key transition of are also presented and analyzed, revealing apredissociationlinewidth peaking near . This behavior can be reproduced only if the triplet structure of the state is included explicitly in the CSE-model calculations, with a spin-orbit constant for the diffuse level which accidentally predissociates . The complex rotational behavior of the and other bands may be an important component in the modeling of EUV transmission through nitrogen-rich planetary atmospheres.

A coupled-channel Schrödinger equation (CSE) model of photodissociation, which includes the effects of all interactions between the , , and and the and states, is employed to study the effects of rotation on the lowest- band oscillator strengths and predissociationlinewidths. Significant rotational dependences are found which are in excellent agreement with recent experimental results, where comparisons are possible. New extreme-ultraviolet (EUV)photoabsorption spectra of the key transition of are also presented and analyzed, revealing apredissociationlinewidth peaking near . This behavior can be reproduced only if the triplet structure of the state is included explicitly in the CSE-model calculations, with a spin-orbit constant for the diffuse level which accidentally predissociates . The complex rotational behavior of the and other bands may be an important component in the modeling of EUV transmission through nitrogen-rich planetary atmospheres.

Rotational temperatures derived from the OH(8–3) band may vary by ~18K depending on the choice of transition probabilities. This is of concern when absolute temperatures or trends determined in combination with measurements of other hydroxyl bands are important. In this paper, measurements of the OH(8–3) temperature-insensitive Q/P and R/P line intensity ratios are used to select the most appropriate transition probabilities for use with this band. Aurora, airglow and solar and telluric absorption in the OH(8–3) band are also investigated. Water vapour absorption of P1(4), airglow or auroral contamination of P1(2) and solar absorption in the vicinity of P1(5) are concerns to be considered when deriving rotational temperatures from this band. A comparison is made of temperatures derived from OH(6–2) and OH(8–3) spectra collected alternately at Davis (69° S, 78° E) in 1990. An average difference of ~4K is found, with OH(8–3) temperatures being warmer, but a difference of this magnitude is within the two sigma uncertainty limit of the measurements.