Insertion of the superior head of the lateral pterigoid muscle in the human fetuses

The lateral pterygoid muscle, more specifically its superior head, as we know, is closely related to the temporomandibular joint (TMJ). Particularly in children, in contrast with what was observed in adults, these joints have been rarely studied, by the anatomic functional aspect, little knowing about its functions in the embryonic and fetal periods. We used, in this work, 12 fetuses ranging in age from 16 to 39 weeks of intrauterine life, where we observed that the superior head of the lateral pterygoid muscle is inserted in the disc and in the articular capsule, in all age groups studied, and also, that the fibers and the thickness of the articular disc is, as well as the articular capsule suffer modifications in accordance with the period of development. © 2007 Sociedad Chilena de Anatom•br>.

Proposal of architecture for launcher systems of unguided sounding rockets

This work presents a proposal of systemic architecture, to make automatic actions in the positioning of launch rail of unguided sounding rockets, which are based on a supervision system, a programmable logical controller, a sensory and actuators, available in Brazilian national market. Copyright © 2006 Society of Automotive Engineers, Inc.

Effect of occlusion on joint sounds in asymptomatic individuals.

Occlusion is a predisposing factor for Temporomandibular Dysfunctions (TMD) of the joint, whose first sign and/or symptom is usually joint sound. To verify the effect of occlusion on joint sounds, temporomandibular joints (TMJ) were analyzed in 78 asymptomatic individuals with various dental conditions. Electrosonography was used to determine the intensity of the vibration in the temporomandibular joint (TMJ) on opening and closing the mouth. Transducers (piezoelectric accelerometer) were placed on the right and left joints. Results were tabled and analyzed using the Kruskal-Wallis test (a=0.05). It was concluded that TMJ vibration in partly edentulous individuals from Kennedy classes I, II and III is statistically higher than in dentate and fully edentulous subjects.

Mechanical behavior of isolated intervertebral disc

The study on several components of intervertebral joints is essential to understand the spine's degenerative mechanisms and to assess the best method for their treatment. For such study it is necessary to know the mechanical properties of the isolated intervertebral disc (ID) mechanical properties and, it is necessary to evaluate its stresses and strains. In order to assess the ID displacements, a fine, U-shaped blade was developed, over which two extensometers connected in a Wheatstone bridge were placed. The device was then tested on porcine spine ID, where compression loads were applied and the extremities displacements of the blade coupled to the intervertebral disc were measured. Stress/strain diagram, both on the compression and on the decompression phases, evidencing the non-linear nature of such relationship. With the experiment, it was possible to obtain approximate values of the longitudinal elasticity module (E) of the disc material and of the Poisson coefficient (n ). After several tests, E results are compatible with those obtained by others studies, with very simple and low-cost device. This experiments can be used for obtained others mechanical properties of isolated ID with precision and accuracy.

Electromyographic evaluation of the temporal muscle after the use of interocclusal splints with a vibrating device in individuals with sleep bruxism

This is the first study performed with an interocclusal splint with a vibrating device on patients with sleep bruxism. The purpose of the present study was to evaluate the effectiveness of the splint with vibrating device on patients who suffer from sleep bruxism through computerized electromyography (EMG) of the anterior temporal muscles. Eight male and female patients, ranging in age from 18 to 28 years, with evident signs and symptoms of bruxism were selected. The splint were made for the upper arch. The patients was treated with the interocclusal splint with a vibrating device, and submitted to EMG evaluations of the anterior temporal muscles on both sides. The evaluations were performed at the beginning of treatment and after 21 days of splint use. Electromyography was performed in an isometric contractions measuring of the temporal muscles. The following results obtained revealed that: when closing the mandible (isometric contraction), the anterior temporal muscles had an expressive reduction in electromyographic activity (p. < 0.10), so this splints were considered effective for patients who suffer from sleep bruxism. © 2009 Springer-Verlag.

Geotechnical and structural behavior of the railroad track in large-scale apparatus

This paper analyses the static and dynamic behavior of the railroad track model in laboratory. Measurements of stresses and strains on a large-scale railroad track apparatus were studied. The model includes: compacted soil, representing the final layers of platform, ballast layer, and ties (steel, wooden, and pre-stressed concrete). The soil and soil ballast interface were instrumented with pneumatic stress gauge. Settlement measurement device were positioned at the same levels as the load cells. Loads were applied by hydraulic actuators, statically and dynamically. After the prescribed number of load cycles, in pre-determined intervals, stresses and strains were measured. Observations indicate that stress and strain distributions, transmitted by wooden or steel ties, behave similarly. A more favorable behavior was observed with pre-stressed concrete mono block ties. Non-linear response was observed after a threshold numbers of cycles were surpassed, showing that the strain modulus increases with the numbers of cycles. © 2009 IOS Press.

Digital radiography for the inspection of weld seams of pipelines - better sensitivity

Conventional radiography, using industrial radiographic films, has its days numbered. Digital radiography, recently, has taken its place in various segments of products and services, such as medicine, aerospace, security, automotive, etc. As well as the technological trend, the digital technique has brought proven benefits in terms of productivity, sensitivity, the environment, tools for image treatment, cost reductions, etc. If the weld to be inspected is on a serried product, such as, for example, a pipe, the best option for the use of digital radiography is the plane detector, since its use can reduce the length of the inspection cycle due to its high degree of automation. This work tested welded joints produced with the submerged arc process, which were specially prepared in such a way that it shows small artificial cracks, which served as the basis forcomparing the sensitivity levels of the techniques involved. After carrying out the various experiments, the digital meth odshowed the highest sensitivity for the image quality indicator (IQI) of the wire and also in terms of detecting small discontinuities, indicating that the use of digital radiography using the plane detector had advantages over the conventional technique (Moreira et al. Digital radiography, the use of plane detectors for the inspection of welds in oil pipes and gas pipes.9th COTEQ and XXV National Testing Congress for Non Destructive Testing and Inspection; Salvador, Bahia, Brazil and Bavendiek et al. New digital radiography procedure exceeds film sensitivity considerably in aerospace applications. ECNDT; 2006; Berlin). The works were carried out on the basis of the specifications for oil and gas pipelines, API 5L 2004 edition (American Petroleum Institute. API 5L: specification for line pipe. 4th ed. p. 155; 2004) and ISO 3183 2007 edition (International Organization for Standardization, ISO 3183. Petroleum and gas industries - steel pipes for pi pelines transportation systems. p. 143; 2007). © 2010 Taylor & Francis.

Transaction costs in the transportation sector and infrastructure in North America: exploring harmonization of standards

Includes bibliography

Relationship between psychological factors and symptoms of TMD in university undergraduate students.

Temporomandibular disorders is a collective term used to describe a number of related disorders involving the temporomandibular joints, masticatory muscles and occlusion with common symptoms such as pain, restricted movement, muscle tenderness and intermittent joint sounds. The multifactorial TMD etiology is related to emotional tension, occlusal interferences, tooth loss, postural deviation, masticatory muscular dysfunction, internal and external changes in TMJ structure and the various associations of these factors. The aim of this study was to evaluate the prevalence of the relationship between signs of psychological distress and temporomandibular disorder in university students. A total 150 volunteers participated in this study. They attended different courses in the field of human science at one public university and four private universities. TMD was assessed by the Research Diagnostic Criteria (RDC) questionnaire. Anxiety was measured by means of a self-evaluative questionnaire, Spielberger's Trait-State anxiety inventory, to evaluate students'state and trait anxiety. The results of the two questionnaires were compared to determine the relationship between anxiety levels and severity degrees of chronic TMD pain by means of the chi-square test. The significance level was set at 5%. The statistical analysis showed that the TMD degree has a positive association with state-anxiety (p = 0.008; p < 0.05) and negative with trait-anxiety (p = 0.619; p < 0.05). Moreover a high TMD rate was observed among the students (40%). This study concluded that there is a positive association between TMD and anxiety.

Photoelastic comparison of single tooth implant-abutment-bone of platform switching vs conventional implant designs

Objectives: The maintenance and stability of peri-implantar soft tissue seem to be related to the crestal bone around the implant platform and different implant designs connections might affect this phenomenon. The aim of this study was to evaluate by photoelastic analysis the stress distribution in the cervical and apical site of implant-abutment interface of conventional implant joints (external hex, internal hex and cone morse) and compare to the novel platform switching design. Materials and methods: It was fabricated photoelastic models using five different implant-abutment connection, one set of external hex (Alvim Ti, Neodent, Curitiba, Brazil), one set of internal hex (Full Osseotite, Biomet 3i, Florida, USA), one cone morse set (Alvim CM, Neodent, Curitiba, Brazil), and two sets of internal hex plus platform switching concept (Alvim II Plus, Neodent, Curitiba, Brazil) (Certain Prevail, Biomet 3i, Florida, USA). These models were submitted to two compressive loads, axial from 20 kgf (load I) and another (load II), inclined 45° from 10 kgf. During the qualitative analysis, digital pictures were taken from a polariscope, for each load situation. For the quantitative analyses in both situations of load, the medium, minimum and maximum in MPa values of shear strain were determined in the cervical and apical site. The Kruskal-Wallis test was used to compare the results between the different systems and between cervical and apical site were compared using Mann-Whitney U test. Results: The results from qualitative analysis showed less concentration of strain in the cervical area to the internal hex plus platform switching (Certain Prevail), in both situation of load. The same results were get in the quantitative analysis, showing less stress concentrations around the implant Certain Prevail with internal hex plus the novel design (17.9 MPa to load I and 29.5 MPa to load II), however, without statistical significant difference between the systems. Conclusion: The minor stress concentration strongly suggest the use of platform switching design as a manner to prevent bone loss around the implant-abutment platform. Clinical Significance: From the result of this study its possible to make clinical decision for implant system which provides implant components with platform switching characteristics.

Optimal trajectory and solution of the inverse kinematics of a robotic manipulator by genetic algorithms

This paper presents the generation of optimal trajectories by genetic algorithms (GA) for a planar robotic manipulator. The implemented GA considers a multi-objective function that minimizes the end-effector positioning error together with the joints angular displacement and it solves the inverse kinematics problem for the trajectory. Computer simulations results are presented to illustrate this implementation and show the efficiency of the used methodology producing soft trajectories with low computing cost. © 2011 Springer-Verlag Berlin Heidelberg.

Use of a type IIB external skeletal fixator in experimental tarsocrural arthrodesis in dogs

The aim of the present study was to evaluate the usefulness of type IIb external skeletal fixators with a transarticular pin in experimental tarsocrural arthrodesis. Twelve adult mongrel dogs of both sexes, ranging in age from two to five years and weighing 12 to 25kg, were used. The configuration of the fixator consisted in the application of a transarticular Steinmann pin and of centrally threaded pins to the proximal portion of the tibia and calcaneus and to the distal portion of the metatarsal bones. In addition, Schanz pins were inserted into the medial and lateral side of the tibia and into the medial side of the metatarsal bones. Radiographs were taken 15; 30 and 45 days after surgery. Bone fusion of the treated joints were observed at 30 days in all animals, and the implants were removed after 45 days. Loosening of the centrally threaded pins was observed in all groups, especially for those applied to the calcaneus. The configuration of the external fixator proposed here was found to be satisfactory in terms of bone union for all joints during the same period, irrespective of the weight of the animal.

Nonlinear dynamic model and simulation of morphing wing profile actuated by shape memory alloys

Morphing aircraft have the ability to actively adapt and change their shape to achieve different missions efficiently. The development of morphing structures is deeply related with the ability to model precisely different designs in order to evaluate its characteristics. This paper addresses the dynamic modeling of a sectioned wing profile (morphing airfoil) connected by rotational joints (hinges). In this proposal, a pair of shape memory alloy (SMA) wires are connected to subsequent sections providing torque by reducing its length (changing airfoil camber). The dynamic model of the structure is presented for one pair of sections considering the system with one degree of freedom. The motion equations are solved using numerical techniques due the nonlinearities of the model. The numerical results are compared with experimental data and a discussion of how good this approach captures the physical phenomena associated with this problem. © The Society for Experimental Mechanics, Inc. 2012.

Concessions and road and rail transport optimization

Includes bibliography

The effect of muscle fatigue on the last stride before stepping down a curb

The stride before landing may be important during stepping down. The aim of this study was to analyze variability of the kinematics and muscle activity in the final stride before stepping down a curb, with and without ankle and knee muscle fatigue. Ten young participants walked at self-selected speed and stepped down a height difference (10-cm) in ongoing gait. Five trials were performed before and after a muscle fatigue protocol (one day: ankle muscle fatigue, another day: knee muscle fatigue). The analysis focused on the trailing leg during the last but one and the last step on the higher level. Kinematics and muscle activity were recorded. Fatigue increased variability of foot-step horizontal distance in the last step on the higher level of the trailing limb, as well as in the first steps on the lower level for both limbs. This appeared due to an increase in the range of motion of the knee joint after both fatigue protocols. Participants additionally showed an increased ankle and hip ROM and decreased knee ROM. Our results suggest a loss of control under fatigue reflected in a higher variability of trailing and leading limb-step horizontal distances, with compensatory changes to limit fatigue effects, such as a redistribution of movement over joints. © 2012 Elsevier B.V.