Sharif Digital Repository

Nowadays , application of enzymes as biocatalysts in wastewater treatment processes is increasing. It is economically important to reuse enzymes and increase their stability in these types of processes. Therefore, was immobilization of enzymes and using them in wastewater treatment have a great importance.In this project, Horseradish peroxidase enzyme, whose effect on phenol removal reactions in other studies has been proven before, was immobilized on the alginate-coated magnetic nanoparticles, to investigate the effect of immobilization on the stability and function of this enzyme for phenol removal. The enzyme was immobilized at the temperature of 25 ° C and pH = 8, according to the data... 

Due to popularity of mobile wireless devices, security of mobile ad hoc networks (MANETs) being more important than before. Traditional key management schemes based on symmetric key cryptography are became ineffective because of dynamic and infrastructureless nature of these networks.Recent studies are mainly based on traditional public key cryptography schemes and ID-based cryptography schemes. On the other hand, Contributory schemes seem suitable for MANETs because of their inherent self-organize property. Key update and Key revocation are the fundamental issues of key management schemes in mobile ad hoc networks. Certificateless public key cryptography, in addition to solve those issues,... 

Blindness is one of the destructive results of retinal diseases. Artificial retina is a device which can help blind people with AMD and RP diseases to restore their vision. Prevalent approaches to artificial retina use an external power supply and processor which the data and energy is transmitted to eye through an inductive link. Taking advantages of solar power, in this project we proposed a design which the required stimulation data and energy is produced internally so the patients don’t have to carry the processor and external power supply that is of major concern for them. This is the most important advantage of this device which doesn’t need any maintenance or battery either. In this... 

With the increase in the usage of wireless networks and smart grid networks and their applications, need for broadcast transmission has been increased dramatically. In order to use these communication, first we need to secure them by cryptographic methods. As authentication is one of the most important aspect of security, introducing secure broadcast authentication schemes are critical. Because of the resources constrainted nodes of these network, it is important to use light cryptographic methods with high security in these schemes. In this work, after analyzing related works, we introduce a new symmetric broadcast authentication scheme which is more efficient in term of memory consumption... 

A free-membrane superconducting transition edge detector was designed and fabricared for IR and THz detection. YBCO superconducting thin films was grown on SrTiO3 (STO) and Yttria Stabilized Zirconia (YSZ) crystalline substrates using RF magnetron sputtering technique and Metal Organic Deposition method. The electrical and optical characterization of the fabricated transition-edge detectors was carried out in a liquid nitrogen based cooling system. The voltage response of the detector was studied in relation to the thermal parameters and the biasing parameters of the device for optimal design of the transition edge detector. Analytical simulations conducted by applying a one-dimensional... 

Injuries of neuro-musculoskeletal system impose large costs to the modem societies. Studying the strategies of CNS in planning and control of movements can be helpful in developing diagnoSiS, prognosis and treatment procedures in clinical view and also in designing rehabilitation system and humanoid robots. Tow important features of human movements are redundancy problem and structured variability. Previous studies solved the redundancy problem mainly with optimization methods. Also optimal feedback control theory is the only method that successfully modeled structured variability in voluntary movements. Despite the appropriate outputs this methods are not based on physiological facts... 

The behavior movement of human is fundamentally concerned with the relationship between the central nervous system of motor control، and musculoskeletal system of a human. Optimal control was employed to relate these structures together. Movement is one of the important part of human life، CNS is important because it has the fundamental role in the movement. Investigators believe that CNS is learned by iteration movements from childhood and finally it chooses the movement that makes a cost function minimum value of itself. Researching for CNS modeling grows in recent years on the different part of human body. Because upper body have less difficulty in movements، it is more useful for CNS... 

Cerebral palsy (CP) is one of the most common motor disability among children that caused by damage to brain or defective development of brain before, during or just after birth. Due to this damage, children with CP have cognitive and motor problems. As an important activity of daily living, walking enhances independence, social activities and quality of life. Much of therapy for children is aimed to improve their gait. A usual technique to evaluate how a person walk and detect abnormal features in walking pattern is gait analysis. Lots of studies have been done on gait kinematics of CPs and classified them based on their kinematis. The purpose of this thesis is studying muscles activity of... 

Cerebral palsy (CP) is one the most prevalent neuromusculoskeletal disease amongst children. Damage in the central nervous system (CNS) causes defective growth of the musculoskeletal system during infancy to maturity, then leading to impairment of selective motor control (SMC), spasticity and sometimes contracture of musculotendinous junction. Treatment of Cerebral Palsy is limited to reduce complications. Medical procedures such as neurosurgery and orthopaedic surgeries or rehabilitation used as a common operation. Recently studies in the field of synergy directed a new path to understanding of human motor control complexity besides identification of functionality of musculoskeletal... 

Contact between different parts of a system and their interactions on each other is one of the most important phenomena that we face in modeling a variety of mechanical issues which should be carefully considered. Sometimes, this phenomenon occurs between different components in a phase and some other times between several phases, which, causes changes in the performance and response of the system. Therefore, in order to investigate its effect in particular on dynamic problems that are subject to severe changes over a short period of time, and to provide more effective methods for dealing with it, the subject of this research has been devoted to dynamic contact modeling with large... 

Using biomechanical models is one of the most effective ways to analyze and assessment of spinal loads in occupational and daily activities. In spite of many advances in the spine modeling, personal factors especially body weight are ignored in most studies. Epidemiological studies show that high body weight is a very strong risk factor of low back pain (LBP) and disc degeneration. There are only few studies that evaluate the relationship between spinal loads and body weight. The goal of this study is analyzing the effect of body weight on spinal load. A detailed musculoskeletal model of lumbar spine with 18 degree of freedom and 76 muscles was developed. This model consists of two parts... 

In cases with excessive anteversion even after adolescence, surgeons have to choose osteotomy surgery to modify this abnormality. This surgery and modifying the anatomical problem does not necessarily lead to modify the patients’ gait cycle abnormalities; the authors’ hypothesis is the probable reason may be the persistence of the implement of the patients’ kinematics compensation mechanism even after the surgery. This mechanism is used to almost correct the gait of those with excessive anteversion. First, by using gait analysis text books, a patient’s gait cycle is analyzed; this analysis is consist of 3DGA with EMG and observational gait. Then, by using OpenSim, the patient’s patterns of... 

Torsional misalignment of lower extremities is a bone deformity of femur, tibia, knee twist or a complex of all these factors. These deformities affect the patient's gait kinematics. These patients are usually treated with osteotomy surgery with the aim of correction of anatomy. But it doesn't necessarily lead to the modification of gait. Therefor development and application of subject-specific musculoskeletal models to analyze patient's specific condition and predict corrective surgery results are considered. Accordingly, the aim of this project is to create a subject-specific musculoskeletal model for a patient with femoral anteversion in order to predict result of anatomical correction... 

Even though Patellofemoral pain syndrome is one of the most frequent pains and disabilities in knee area, the pathology of this illness has not achieved the needed accuracy and clearness. Most researchers believe the cause of this pain syndrome and disability of it, is abnormal activities of patella. Nevertheless, no non-invasive method has been presented to measure three-dimensional movements of patella in patients. It seems evolving a method based on tactile tracking which surface and touchable trait of knee bone is used can benefit to measure three-dimensional movements of patella non-invasively. On the basis of this, the main idea of the project is registering the pressure changes in... 

Several diseases and injuries may cause disability in locomotion (especially walking). Spinal cord injuries, brain stroke and disease like Parkinson are the most major causes. In the past, some efforts has been made to reduce the effect of organ’s disabilities, but today, there is the chance of healing the spinal cord injury By using new (Schwann Cell) method. Due to long time stillness and severe muscles weakness; condensed physiotherapy exercise is essential to recover locomotion abilities, particularly in walking. In this way, if the practices matches with the normal walking (especially weight bearing); it has more physiological and psychological effect. In order to achieve this goal, a... 

Low back disorders (LBD) is one of the most musculo-skeletal disorders in industrial environments in which it can impose to the society.Therefore, it is very important to reaserch the causes of LBDs, prevention methods and evaluation risk factor in lifting tasks in order to avoid the prevalence of LBDs in society. There is no doubt heavy lifting has a significant role in emerging of LBDs. Hence, many safety risk assessment tools have been made by researchers.Using assessment tools, we need to know the input parameters corrospending to the assessment tools. Input parameters in assessment tools have been measured in a way of traditional method or by expensive equipment in laboratories. On... 

Turan Toad-headed Agama is a lizard (Phrynocephalus mystaceus) inhabiting in the deserts of the Middle East. In order to hide from predators, it laterally vibrates (and slightly oscillates around the dorsal axis) to descend beneath the sand. Despite its low density, toad-headed agama easily burrows beneath the sand. The purpose of this study is to initially determine 3D kinematics of the agama's burial technique (frequency, amplitude and position of critical points of the body). After determining the motion, we will figure how the motion interacts with granular media and enables the animal to burry. This includes simulating animal's motion within granular media using discrete element method... 

The recent project can be considered as a subset of Telerehabilitation, in the field of Telerehabilitation can be defined as the need for long-term data recording in order to determine each individual's movement pattern and compare it to the individual's best model or best practice. With this perspective, it can be said that the recent project, in more detail, remotely targets the use of foot plantar pressure to determine locomotor parameters. With this description, the FSR or force sensitive resistor sensor was selected for a number of reasons, including low cost, low weight and low thickness, and the data acquisition circuit was used to convert the sensors' analog signal to digital output,... 

Lifting is considered a major risk to people's health in life, particularly to the workers. Appropriate wearable tools for measuring the individual’s kinematic and kinetic movement are required for examining and analyzing the lifting activity to prevent injury in the workplace. Different wearable systems have been developed to calculate the force applied on the foot sole to analyze movement in various areas of gait analysis, occupational biomechanics, sports, and other areas. The accuracy and precision of these systems need to be tested before application in any of these areas. In this study, 3 subjects performed five different activities of symmetrical lifting by placing Pedar insoles in...