Response of Piled Raft Foundation on Soft Clay Under Seismic Load

A number of researchers has extensively investigated the vertical load bearing mechanism of piled raft foundation, by applying elasticity theory and finite element method. The study on the load bearing mechanism under horizontal loading or during earthquakes, however, is very limited. This is partially because piled raft foundations are considered as raft foundations in the current design practice. Since the behavior of a piled raft foundation during earthquakes is considered fairly complex due to dynamic interaction among a raft, piles and a soil, the design procedure should include the effect of this mechanism in an appropriate manner. In other hands, the behavior of piled raft foundations under earthquake loading is an important factor affecting the performance of structures. Observations from past earthquakes have shown that piles in firm soils generally perform well, while those installed in soft or liquefiable soils are more susceptible to problems arising from ground amplification or excessive soil movements. This research comprises three major components: (1) Numerical modeling of piled raft foundation using finite element program (ABAQUSE), (2) verification of numerical program with dynamic centrifuge tests on clay pile-raft systems, and (3) performing parametric studies. The acceleration predicted by numerical method is well matched with the measured acceleration in a centrifuge test when simulating a piled raft foundation

Security challenges in mobile assisted language learning in the millennium for education

Distance learning technologies enrich learning opportunities due to many advantages like ubiquity and flexibility. Although the usefulness of such technologies in teaching and learning is clear, their testing part is remained to be discussed due to the security issue. Administrators and teachers need to use more authentic and secure distant testing software in which the scores are guaranteed and the testees keep away from cheating. Static and online authentication systems like “username” and “password” and face detection have empowered educational parties to have more reliable testing outcomes. Mobile devices as the necessity of the new millennium need to use authentication software in their testing. Mobile devices with their multimedia course materials provide learners with many optimistic learning opportunities through collaboration, cooperation, interaction and testing. The unique chances of ubiquity, individualization, informality, and spontaneity make the mobile learning of particular importance not only for digital natives but also for teachers, administrators, developers, instructors, and policy makers. Yielding an economical learning opportunity along with providing authentic contexts for collaborative learning is beneficial for the economy of the country in general an d for the meaningful and deep learning of the learners. This paper will discuss how authentication techniques have applied to electronic devices like mobile phones

A Laguerre spectral method for quadratic optimal control of nonlinear systems in a semi-infinite interval

This paper presents a Laguerre homotopy method for quadratic optimal control problems in semi-infinite intervals (LaHOC), with particular interests given to nonlinear interconnected large-scale dynamic systems. In LaHOC, the spectral homotopy analysis method is used to derive an iterative solver for the nonlinear two-point boundary value problem derived from Pontryagin\u27s maximum principle. A proof of local convergence of the LaHOC is provided. Numerical comparisons are made between the LaHOC, Matlab BVP5C generated results and results from the literature for two nonlinear optimal control problems. The results show that LaHOC is superior in both accuracy and efficiency

BIOMECHANICAL EFFECTS OF ORTHOTIC WEDGING ON SPORTS AND ACTIVITIES IN PATIENTS WITH PLANTAR FASCIITIS

Plantar Fasciitis is an inflammatory stress syndrome of the plantar fascia and the most common hind foot problem in runners (Anderson, 2000). It is related to the stress on the plantar fascia from the weight of and the activity combined with weight transfer up onto the toes which leads to metatarsophalangeal joint extension and causes a “windlass” effect on the plantar fascia. Different conditions such as excessive tightness of Achilles tendon, excessive or prolonged pronation, pes cavus, or obesity can overload the plantar fascia origin on the anteromedial aspect of the calcaneus during weight bearing activities (Taunton et al, 1996)

Pedobarography of the coper and non-coper ACL-deficient knee subjects during single and double leg stance

Introduction: Biomechanical studies have frequently shown a close relationship between the knee and ankle joint movements. ACL-deficiency may change the foot pressure pattern of the ACL-deficient knee subjects. The current study aimed to investigate the pattern of the foot pressure in coper and non-coper ACL-deficient knee subjects during standing on one and both feet. Methods and Materials: This case-control study was conducted on 12 coper and 12 non-coper ACL-deficient knee subjects and 25 age-sex matched healthy subjects. The subjects were tested barefoot during single and bilateral standing on the platform of a Zebris pedobarograph tool. The outcome measures included the measurements of the pressures of each part of the foot during the tests. Results: The results showed a significantly decreased total pressure only between the non-coper and control groups during double leg stance test. In terms of the forefoot pressure, a significant increased pressure was shown only in the non-coper ACL-deficient knee subjects during both single and double leg stance tests (P<0.05). In both test conditions, the coper ACL-deficient knee subjects showed forefoot and hind foot pressures very close to the control group (P>0.05). Conclusion: This study revealed marked changes following ACL-deficiency mainlyin non-coper ACL-deficient knee subjects. The increased forefoot pressure in non-coper ACL-deficient knee subjects was probably due to the forwarded line of gravity in these patients aligned with their base of support to keep their knees more stable. Further studies are needed to verify the differences between the male and female ACL-deficient knee subjects.Keywords: Coper/non-coper ACL-deficient knee subjects; Stability; Pedobarograph; Foot pressure system; Postural contro

The Effects of Knee Orthosis with Two Degrees of Freedom Joint Design on Gait and Sit-to-Stand Task in Patients with Medial Knee Osteoarthritis

Objectives: Knee bracing as a conservative treatment option for patients with medial knee osteoarthritis (KOA) is of great interest to health practitioners and patients alike. Optimal orthotic knee joint structure is essential to achieve biomechanical and clinical effectiveness. Therefore, this study aimed to identify the effects of a knee orthosis with a new two-degrees-of-freedom (DOF) joint design on selected gait parameters and in a sit-to-stand task in patients with mild-to-moderate medial KOA. Methods: This study was conducted both at the Physical Medicine and Rehabilitation Clinic in Shahid Modarres Academic Hospital and the Biomechanical Laboratory of Rehabilitation Faculty of Iran University of medical Sciences in Tehran, Iran from September 2015 to October 2017. The gait performance of 16 patients was assessed without an orthosis, using a common one-DOF (DOF) knee orthosis and using the same knee orthosis with a two-DOF orthotic joint design. The interactive shearing force between limb and brace in the shell area during a sit-to-stand test was also identified. Repeated measures analysis of variance was used to analyse the data. Results: Compared with walking with no orthosis, both orthosis conditions reduced the external knee adduction moment significantly (P ≤0.05). A significant increase between the one-DOF and two-DOF conditions in terms of walking speed (P = 0.041 and P = 0.009, respectively) and stride length (P = 0.028 and P = 0.038, respectively) was observed. In a sit-to-stand test, wearing the orthosis significantly decreased knee transverse plane range of motion (P ≤0.05). There was a 41.31 ± 8.34 Newtons reduction in knee flexion constraint force. Conclusion: The two-DOF knee orthosis was more comfortable compared to the one-DOF knee orthosis during deep knee flexion. Otherwise, the one- DOF- and two-DOF-braces performed similarly. Keywords: Knee Osteoarthritis; Orthosis; Braces; Gait Analysis; Rotations; Kinematics; Kinetics; Patient Comfort

Design, Implementation and Testing of a Novel Prototype Orthotic Knee Joint with Two Degrees of Freedom in a Patient with Medial Knee Osteoarthritis

Knee braces are a conservative treatment option for patients with knee osteoarthritis (KOA). However, no commercially available orthotic knee joint currently reflects natural knee movements. A prototype orthotic knee joint with two degrees of freedom (DOF) in the sagittal and transverse planes was developed to more closely simulate the natural motion of the knee joint. The prototype was tested on a male subject with medial KOA during a sit-to-stand task. The efficacy of the transverse plane DOF was assessed by comparing the limb-orthosis interaction force when the transverse plane was locked to mimic a one-DOF setting versus when it was unlocked. Unlocking the transverse plane eliminated the 45-Newton shearing force produced with the one-DOF setting at wide angles of flexion. The two-DOF orthotic knee joint prototype demonstrated greater conformity to natural knee movements, allowing the wearer to better tolerate bracing-related difficulties.  Keywords: Knee Joint; Knee Osteoarthritis; Orthotic Devices; Braces; Rotation; Movement; Materials Testing

Emotional Disorders in Pediatric Renal Transplant Recipients: A Comparative Study

Introduction: Kidney transplantation is recognized as the optimal therapy for children with ESRD. We performed this study to compare the children’s behavioral problems and their parents’ function in pediatric patients with Kidney transplantation in Arak Amir Kabir Hospital.Materials and Methods: To perform this case-control study, we recruited 29 children with renal transplantation and compared them with 29 healthy children aged 5-14 years old. The Child Behavior Checklist (CBCL4/18) was used for the assessment of the children’s behavioral problems and Global Assessment of functioning (GAF) was employed for the evaluation of their parents’ behaviors. Results: Among 29 patients with RTR, anxiety/depression, somatic complaints, social problems, and attention problem were demonstrated in 65.5%, 55.1%, 51.7%, and 76%, respectively. We found a significant difference between cases and controls. Delinquent and aggressive behavior was not seen in two groups. As a significant difference, the parents’ mean stress and behavior score in case and control groups was 22.4% and 63.1%, respectively.   Conclusions: The higher prevalence of behavioral problems in the renal transplant recipients and their parent’s functional impairment highlights the importance of early parental intervention for early prevention of future behavioral problems in their siblings.Keywords: Emotional Disturbances; Renal Transplantation, Child

National and sub-national environmental burden of disease in Iran from 1990 to 2013-study profile

Development of national evidence-based public health strategies requires a deep understanding of the role of major risk factors (RFs) and the burden of disease (BOD). In this article, we explain the framework for studying the national and sub-national Environmental Burden of Disease (EBD) in Iran as a part of the National and Sub-national Burden of Disease (NASBOD) study.; The distribution of exposures to environmental RFs and their attributable effect size over 1990-2013 will be estimated through comprehensive reviews of either published or unpublished sources. Statistical modeling will be used to impute missing data in the distribution of RFs exposures for each district-year. National and sub-national BOD attributable to these RFs will be estimated in the following metrics: Prevalence, death, years of life lost due to premature death (YLL), years of life lost due to disability (YLD), and disability-adjusted life years lost (DALYs). The BOD attributable to the current distribution of exposures will be compared with a counterfactual exposure distribution scenario-here, the theoretical-minimum-risk exposure distribution. Inequalities in the distribution of exposure to RFs will be analyzed and manifested nationwide using geographic information systems.; The EBD study aims to provide an official report to Iranian Ministry of Health and Medical Education, to publish a series of articles on the exposure trends of the selected environmental RFs, to estimate the BOD attributable to these RFs, and to assess inequalities and its determinants in the distribution of exposure to RFs. Iran's territory is large with diverse population, socioeconomic, and geographic areas. Results of this comparative risk assessment study may pave the way for health policy makers to plan more comprehensive and cost-effective evidence-based strategies