2,616 research outputs found
PREDICTION OF TRUNK MUSCLE FORCES AND INTERNAL LOADS DURING FORWARD FLEXION ACTIVITIES
Knowledge of load distribution among passive and active components of the human trunk during various occupational and sportive activities is essential to assess the risk of injury and to improve prevention, evaluation, and rehabilitation of spinal disorders. To solve the trunk redundancy toward determination of muscle forces and passive loads in forward bending tasks ± loads in hands, a novel synergistic kinematics-based approach coupled with a nonlinear finite element model are introduced. As a part of this study, trunk kinematics needed as input data and surface EMG activity of selected c:.bdominal/back muscles needed for validation of model are measured in normal subjects during isometric forward bending tasks. Predictions are in satisfactory agreement with in vivo measurements. The model proves promising in exercise and rehabilitation applications
Film censorship in Egypt: power and subject-making
This study’s focus is censorship on film in Egypt from 1971 onwards; when the first sign of incorporating religion as a source of law appeared with the addition of article 2, which states that “Islamic Shari’a is a main source of legislation.” Film is the most culturally powerful artistic medium in the Egyptian society due its mass consumption and has, from its point of introduction, served as a mirror into Egyptian politics and morality. Foucault’s mission of understanding how “subjectivity” forms and the power relations/modes that bring it about is a lens through which this project intends to examine the dynamic of artists, artistic material and their relationship to different power mechanisms in Egypt as they induce subjectivity. This study argues that the Egyptian state operates within a certain power dynamic that has allowed the freezing of a moral framework, which began in the 1970s. This framework began with a constitutional makeup that intended to and was successful in making a specific moral and religious ideal permanent, allowing it to permeate Egyptian society, and which can be traced through observing censorship of film. This dynamic has resulted in a peculiar reaction from artists and intellectuals, along with the public, who, holding on to a moral archetype that needs to be protected by the state, have accepted the concept of censorship to varying degrees, and have all at one point deemed it somehow necessary rather than revolted against it
Super insulation material in district heating pipes
In Swedish district heating systems, 10% of the produced energy is lost at the distribution network. It is of interest to lower the energy losses both for economic and environmental reasons. Since 2011 the feasibility of using superinsulation material for insulation of the district heating pipes were studied. Apparent thermal conductivity and long term performance of vacuum panels has been identified has the crucial challenge for using vacuum insulation panels. The estimated life time of a vacuum panel in building applications at 90 °C is about 50 years. The life time estimation is based on the climate condition valid for building application. However, peak temperature in a district heating system can be about 140°C. Hybrid insulated pipes with a Vacuum Insulated Panel (VIP) have been tested and evaluated by laboratory and field measurements. The results of numerical analyses of the measured data indicate a possible small degradation of the VIP at a similar rate as building application, even though the operative temperature is between 80-100 °C. In the laboratory a hybrid insulated pipe has withstood exposure to one sided heating at 115°C for over 5 years. The results indicate that hybrid insulated district heating pipes reduce heat losses by 20-30% for a twin pipe and with more than 50% in a single pipe. It can be concluded that VIP shows promising performance in district heating pipe application
Super insulation material in district heating pipes
In Swedish district heating systems, 10% of the produced energy is lost at the distribution\ua0network. It is of interest to lower the energy losses both for economic and environmental\ua0reasons. Since 2011 the feasibility of using superinsulation material for insulation of the district\ua0heating pipes were studied. Apparent thermal conductivity and long term performance of\ua0vacuum panels has been identified has the crucial challenge for using vacuum insulation panels.The estimated life time of a vacuum panel in building applications at 90 \ub0C is about 50 years.\ua0The life time estimation is based on the climate condition valid for building application.\ua0However, peak temperature in a district heating system can be about 140\ub0C.\ua0Hybrid insulated pipes with a Vacuum Insulated Panel (VIP) have been tested and evaluated\ua0by laboratory and field measurements. The results of numerical analyses of the measureddata indicate a possible small degradation of the VIP at a similar rate as building application,\ua0even though the operative temperature is between 80-100 \ub0C. In the laboratory a hybrid\ua0insulated pipe has withstood exposure to one sided heating at 115\ub0C for over 5 years. The\ua0results indicate that hybrid insulated district heating pipes reduce heat losses by 20-30% for\ua0a twin pipe and with more than 50% in a single pipe. It can be concluded that VIP shows\ua0promising performance in district heating pipe applications
Competition and Predation in Soil Fungivorous Microarthropods Using Stable Isotope Ratio Mass Spectrometry
The soil food web is often described as having three main energy channels: root, bacterial and fungal. Here we provide quantitative data using a sensitive stable isotope ratio mass spectrometry procedure with microcosms on species interactions in the fungal pathway. We measured 15N and 13C enrichment in microarthropods through grazing rare isotope enriched fungal mycelia. Experimental treatments were various combinations of 1, 2, 3, 4 microarthropods species. We used three fungivores (the collembolan Lepidocyrtus curvicollis, the Astigmata Tyrophagus putrescentiae, the Oribatida Oribatula tibialis.), and the Mesostigmata predator Hypoaspis acquilifer We collected individuals of each species separately, as well as their faeces, and moult where available. All three fungivorous microarthropods consumed significantly more than their own body weight per day. The three fungivores differed in their consumption of the mycelium as it was not equally palatable to each. The Mesostigmata predator Hypoaspis also differed in its microarthropod prey preference. In multiple species combinations microarthropod behavioural interactions modified consumption and predation rates. Our selection of mites of different sizes, with varied preference for the mycelium, combined with differing predation rates on each mite, demonstrate that even three trophic level interactions with only five interacting species are not predictably simple. The interpretation of the stable isotope results and consumed-excreted weights indicate that: a) behaviour and microscopic observations should not be ignored in competition-predation interactions, and b) functional guilds can take advantage of more diverse food opportunities. The reality of mixed diets complicates functional guild assignments that are reflected in 15N and 13C isotope levels at natural abundances in the environment. Microcosm experiments with this sensitive technique can help decipher the interpretation of rare isotope natural abundance values, as well as providing measured consumption, growth, and excretion rate values for modelling soil food web interactions
RESPONSE ANALYSIS OF THE KNEE JOINT IN FLEXION UNDER QUADRCEPS ACTIVATION
The human knee joint is a complex structure with interactions between muscle forces, ligaments, menisci and articulations at different regions. Proper management of rehabilitation and treatment programs requires a solid understanding of such interactions in intact and injured conditions. Towards this goal, a realistic nonlinear 3-D finite element model of the entire knee joint is developed. In this work, the ligament forces and contact stresses/areas are computed as the unconstrained joint is flexed from 0° to 90° ± a constant 137 N quadriceps force. Predictions support the coupling between various components as a function of quadriceps exertion and flexion angle. The model is promising in augmenting our understanding of the joint function leading to improved design for rehabilitation programs and replacement procedures in active patients
Posterior distributions for likelihood ratios in forensic science
Evaluation of evidence in forensic science is discussed using posterior distributions for likelihood ratios. Instead of eliminating the uncertainty by integrating (Bayes factor) or by conditioning on parameter values, uncertainty in the likelihood ratio is retained by parameter uncertainty derived from posterior distributions. A posterior distribution for a likelihood ratio can be summarised by the median and credible intervals. Using the posterior mean of the distribution is not recommended. An analysis of forensic data for body height estimation is undertaken. The posterior likelihood approach has been criticised both theoretically and with respect to applicability. This paper addresses the latter and illustrates an interesting application area
KNEE JOINT LIGAMENT RECONSTRUCTION: ON PRETENSION AND COUPLING IN CRUCIATE LIGAMENTS
Wide range of knee cruciate ligament reconstruction procedures with different materials, stiffness, pretensions, orientations, and insertion locations are currently used with the primary goal to restore the joint laxity. With the general lack of success in preservation of force in the reconstructed ligament, the concern, not yet addressed, arises as to the effect of reconstruction on the other intact cruciate ligament. Using a 3-D finite element model, we examined this hypothesis by varying the pretension in each ligament under flexion ±A-P loads and quantifying the extent of coupling between cruciate ligaments. A remarkable coupling was predicted. Moreover, changes in laxity and in ligament forces as ligament pretension was altered varied with flexion and loads. These findings have important consequences in proper management and rehabilitation of the joint ligament disorders
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