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    Design and fabrication of a centrifugal microfluidic disc including septum valve for measuring hemoglobin A1c in human whole blood using immunoturbidimetry method

    , Article Talanta ; Volume 190 , 2018 , Pages 134-139 ; 00399140 (ISSN) Mahmodi Arjmand, E ; Saadatmand, M ; Bakhtiari, M. R ; Eghbal, M ; Sharif University of Technology
    Elsevier B.V  2018
    Abstract
    Diabetes mellitus is a global endemic with a rapidly increasing prevalence in both developing and developed countries. Recently, hemoglobin A1c has been recommended by the American Diabetes Associations as a possible substitute for fasting blood glucose for the diagnosis of diabetes, because it is an indicator of long-term glycemic control. Also, centrifugal microfluidic systems have good potential for use in the point of care testing systems. In this study, a centrifugal microfluidic disc was designed and manufactured to measure hemoglobin A1c in whole blood using an immunoturbidimetry based method. Also, a new passive valve, named septum valve, was presented to precisely control the entry... 

    A centrifugal microfluidic platform to measure hemoglobin of whole blood

    , Article 2017 24th Iranian Conference on Biomedical Engineering and 2017 2nd International Iranian Conference on Biomedical Engineering, ICBME 2017, 30 November 2017 through 1 December 2017 ; 2018 ; 9781538636091 (ISBN) Mahmodi Arjmand, E ; Saadatmand, M ; Bakhtiari, M. R ; Eghbal, M ; Balaei, A ; Sharif University of Technology
    2018
    Abstract
    Microfluidics has been becoming more and more popular over last two decades. The reason for this, is inherent features of microfluidics including low consumption of samples and reagents, high sensitivity, short analysis time, and low cost. As well as, centrifugal microfluidics as a subset of microfluidics has been able to prove itself as a helpful tool in analytic assays. The main application of centrifugal microfluidic devices is being used in point-of-care testing systems. Herein, we presented a microfluidic disc for measuring hemoglobin(Hb) concentration in the EDTA-anticoagulated venous blood using cyanmethemoglobin method. In this experiment, at first a hand-made standard solution was... 

    A new detection chamber design on centrifugal microfluidic platform to measure hemoglobin of whole blood

    , Article SLAS Technology ; Volume 26, Issue 4 , 2021 , Pages 392-398 ; 24726303 (ISSN) Mahmodi Arjmand, E ; Saadatmand, M ; Eghbal, M ; Bakhtiari, M. R ; Mehraji, S ; Sharif University of Technology
    SAGE Publications Inc  2021
    Abstract
    Undoubtedly, microfluidics has been a focal point of interdisciplinary science during the last two decades, resulting in many developments in this area. Centrifugal microfluidic platforms have good potential for use in point-of-care devices because they take advantage of some intrinsic forces, most notably centrifugal force, which obviates the need to any external driving forces. Herein, we introduce a newly designed detection chamber for use on microfluidic discs that can be employed as an absorbance readout step in cases where the final solution has a very low viscosity and surface tension. In such situations, our chamber easily eliminates the air bubbles from the final solution without... 

    Synthesis and absorbency of gelatin-graft-poly(sodium acrylate-co- acrylamide) superabsorbent hydrogel with saltand pH-responsiveness properties

    , Article E-Polymers ; 2006 , Pages 1-15 ; 16187229 (ISSN) Pourjavadi, A ; Sadeghi, M ; Mahmodi Hashemi, M ; Hosseinzadeh, H ; Sharif University of Technology
    European Polymer Federation  2006
    Abstract
    In this article, we synthesize a novel gelatin-based superabsorbent hydrogel via graft copolymerization of mixtures of acrylic acid (AA) and acrylamide (AAm) onto gelatin backbones. The polymerization reaction was carried out in an aqueous medium and in the presence of ammonium persulfate (APS) as an initiator and N,N-methylene bisacrylamide (MBA) as a crosslinker. The hydrogel structures were confirmed by FTIR spectroscopy. The effect of grafting variables, i.e. concentration of MBA and APS, AA/AAm weight ratio, and reaction time and temperature, was systematically optimized to achieve a hydrogel with swelling capacity as high as possible. The swelling behavior of these absorbent polymers... 

    The effect of parameters of equilibrium-based 3-D biomechanical models on extracted muscle synergies during isometric lumbar exertion

    , Article Journal of Biomechanics ; Volume 49, Issue 6 , 2016 , Pages 967-973 ; 00219290 (ISSN) Eskandari, A. H ; Sedaghat Nejad, E ; Rashedi, E ; Sedighi, A ; Arjmand, N ; Parnianpour, M ; Sharif University of Technology
    Elsevier Ltd  2016
    Abstract
    A hallmark of more advanced models is their higher details of trunk muscles represented by a larger number of muscles. The question is if in reality we control these muscles individually as independent agents or we control groups of them called "synergy". To address this, we employed a 3-D biomechanical model of the spine with 18 trunk muscles that satisfied equilibrium conditions at L4/5, with different cost functions. The solutions of several 2-D and 3-D tasks were arranged in a data matrix and the synergies were computed by using non-negative matrix factorization (NMF) algorithms. Variance accounted for (VAF) was used to evaluate the number of synergies that emerged by the analysis, which... 

    Stereoselective synthesis ofβ-Amino ketones via direct mannich-type reaction catalyzed with SO 2- 4/TiO 2 and SO 2- 4/nano TiO 2

    , Article Synthetic Communications ; Volume 39, Issue 24 , 2009 , Pages 4441-4453 ; 00397911 (ISSN) Samet, M ; Eftekhari Sis, B ; Mahmodi Hashemi, M ; Farmad, F ; Sharif University of Technology
    2009
    Abstract
    At room temperature, SO 2- 4/nano-TiO 2 efficiently catalyze the direct Mannich-type reaction of varieties of in situ-generated aldimines using aldehydes and anilines with ketones in a three-component reaction under solvent-free conditions. The reaction proceeds rapidly and affords the correspondingβ-amino ketones in good to high yields with good to excellent stereoselectivity. The catalyst can be recycled for subsequent reactions without any appreciable loss of efficiency  

    The potential application of particle swarm optimization algorithm for forecasting the air-overpressure induced by mine blasting

    , Article Engineering with Computers ; 2017 , Pages 1-9 ; 01770667 (ISSN) AminShokravi, A ; Eskandar, H ; Mahmodi Derakhsh, A ; Nikafshan Rad, H ; Ghanadi, A ; Sharif University of Technology
    2017
    Abstract
    In tunneling projects and open-pit mines, drilling and blasting is a common method for fragmenting the rock masses. Although fragmentation is the main aim of blasting, the adverse effects such as air-overpressure (AOp) and ground vibration are unavoidable. Among these unwanted effects, AOp is considered as one of the most important effects which can cause damage to nearby structures. Therefore, precise estimation of AOp is required for minimizing the environmental problems. This article proposes three new models for predicting blast-induced AOp at Shur river dam area, Iran, optimized by particle swarm optimization (PSO). For this aim, 80 blasting events were investigated and the requirement... 

    The potential application of particle swarm optimization algorithm for forecasting the air-overpressure induced by mine blasting

    , Article Engineering with Computers ; Volume 34, Issue 2 , 2018 , Pages 277-285 ; 01770667 (ISSN) Aminshokravi, A ; Eskandar, H ; Mahmodi Derakhsh, A ; Nikafshan Rad, H ; Ghanadi, A ; Sharif University of Technology
    Springer London  2018
    Abstract
    In tunneling projects and open-pit mines, drilling and blasting is a common method for fragmenting the rock masses. Although fragmentation is the main aim of blasting, the adverse effects such as air-overpressure (AOp) and ground vibration are unavoidable. Among these unwanted effects, AOp is considered as one of the most important effects which can cause damage to nearby structures. Therefore, precise estimation of AOp is required for minimizing the environmental problems. This article proposes three new models for predicting blast-induced AOp at Shur river dam area, Iran, optimized by particle swarm optimization (PSO). For this aim, 80 blasting events were investigated and the requirement... 

    Investigation of the Role of Fiber Reinforcement on the Performance of Rubber Based Friction Material

    , M.Sc. Thesis Sharif University of Technology Arjmand, Mohammad (Author) ; Shojaei, Akbar (Supervisor)
    Abstract
    Friction composites, as a part of vehicle safety system, should hold some characteristics such as high wear resistance, low weight, durability, low noise, stable friction coefficient, availability and low price. It is very interested to use mixture of rubber and resin in friction materials to reach good properties of both rubber and resin simultaneously. This mixture is especially used in railway’s brake pads. Fibrous reinforcement is another important ingredient in friction composites. Asbestos used to be the most significant fibrous reinforcement due to its appropriate tribological specifications but the recent ban on asbestos by environmental protection agency has forced the friction... 

    Effect of Iatrogenic Muscle Injuries on Spine Biomechanics During Posterior Lumbar Surgeries Using a Biomechanical Model for Design of Rehabilitation Exercises

    , M.Sc. Thesis Sharif University of Technology Jamshidnezhad, Saman (Author) ; Arjmand, Navid (Supervisor)
    Abstract
    Posterior lumbar surgery is often associated with extensive injuries to back muscles. In this thesis, the effect of such iatrogenic injuries in some patients was examined. For this purpose, the CSA of back muscles in 6 patients were measured using MR scan. To examine any natural change in CSAs of healthy people or instrument errors, same measurement were carried out on 10 healthy volunteers. In addition, a detailed anatomical model of an intact human spine was developed. With the aim of experimental studies and intact model, the post-operative model of patients was also developed. These two models were used to quantizing the change in activity of back muscles during some symmetric, normal... 

    A Hyrid EMG-optimization Based Model of the Lumbar Spine to Estimate Muscle Forces in Different Tasks

    , M.Sc. Thesis Sharif University of Technology Mohammadi, Yousef (Author) ; Arjmand, Navid (Supervisor)
    Abstract
    Low back pains (LBP) are prevalent and costly. One of the important factors causing LBP is excessive axial compression and shear forces that are applied on the intervertebral discs during different activities. Due to lack of direct in vivo measurement methods for estimating these loads, musculoskeletal biomechanical models have been emerged as indispensable tools under various activities. Different biomechanical models have been suggested to estimate muscle forces and spinal loads base on optimization, EMG and hybrid (EMG assisted optimization, EMGAO) methods. Although there have been a number of studies on the differences between various optimization and EMG-based methods, there has been no... 

    Evaluation of 1991 NIOSH Lifting Equation in Controlling the Biomechanical Loads of the Human Spine

    , M.Sc. Thesis Sharif University of Technology Lesani, Ali (Author) ; Arjmand, Navid (Supervisor)
    Abstract
    The 1991 NIOSH Lifting Equation (NLE) is widely used to assess risk of injury to the spine by providing estimates of the recommended weight limit (RWL) in hands. The present study uses two biomechanical models of the spine to verify whether the RWL generates L5-S1 loads within the limits (e.g., 3400 N for compression recommended by NIOSH and 1000 N for shear recommended in some studies).Severallifting activities are simulated here to evaluate the RWL by the NLE and the L5-S1 loads by the models. In lifting activities involving moderate to large forward trunk flexion, the estimated RWL generates L5-S1 spine loads exceeding the recommended limits. The NIOSH vertical multiplier is the likely... 

    Lumbopelvic Rhythm during Forward and Backward Sagittal Trunk Rotations; in vivo Measurements Using Inertial Sensors

    , M.Sc. Thesis Sharif University of Technology Tafazzol, Alireza (Author) ; Arjmand, Navid (Supervisor)
    Abstract
    Direct in vivo measurements of spinal loads and muscle forces are invasive. Investigators have thus used musculoskeletal biomechanical models that require kinematic data including trunk and pelvis angular movements as their inputs. . Novel devices measure anglular movements using both inertial sensors (such as gyroscopes and accelerometers) and miniature magnetometers. Relative low cost, portability, and accuracy are among specific characteristics of inertial tracking devices. The main objective of the present study was set to measure spinal kinematics including the lumbopelvic rhythm as the ratio of total lumbar rotation over pelvic rotation during trunk sagittal movement which is essential... 

    Tribological characteristics of rubber-based friction materials

    , Article Tribology Letters ; Volume 41, Issue 2 , October , 2011 , Pages 325-336 ; 10238883 (ISSN) Arjmand, M ; Shojaei, A ; Sharif University of Technology
    2011
    Abstract
    This article deals with the rubber-based friction materials (RBFMs) which can be used in brake system. The physico-mechanical and tribological properties of a series of fiber filled RBFMs containing steel wool and aramid pulp at different concentrations along with a fiber-free reference material were characterized. Rubber-glass transition induced at higher sliding velocities was identified based on the friction fade behavior of the RBFMs. The rubber-glass transition which is inherently originated by viscoelastic response of polymeric binder was found to be influential on the tribological properties of the RBFMs. It was revealed that steel wool increased coefficient of friction (COF) and... 

    Sagittal Range of Motion of the Thoracic Spine Using Inertial Tracking Device and Effect of Measurement Errors on Model Predictions

    , M.Sc. Thesis Sharif University of Technology Hajibozorgi, Mahdieh (Author) ; Arjmand, Navid (Supervisor)
    Abstract
    Range of motion (ROM) of the thoracic spine has implications in patient discrimination for diagnostic purposes and in biomechanical models for predictions of spinal loads. Few previous studies have reported quite different thoracic ROMs. Total (T1-T12), lower (T5-T12) and upper (T1-T5) thoracic, lumbar (T12-S1), pelvis, and entire trunk (T1) ROMs were measured using an inertial tracking device as asymptomatic subjects flexed forward from their neutral upright position to full forward flexion. Correlations between body height and the ROMs were conducted. Effect of measurement errors of the trunk flexion (T1) on the model-predicted spinal loads was investigated. Mean of peak voluntary total... 

    A Detailed Finite Element Model of the Lumbar Spine under Muscle Forces

    , M.Sc. Thesis Sharif University of Technology Asadi, Hamed (Author) ; Arjmand, Navid (Supervisor)
    Abstract
    Etiological studies proves the fact that Low Back Pain (LBP) is one of the most expensive and prevalent desease all over the world. This fact illustrates the reqiurment of the special effort in ordet to reducing the pain due to this problem. Finite element modeling of human spine is one the suitable methods to simulate the behavior of human spine in different loading conditions. These conditions could be different daily occupational tasks. There is two general viewpoint toward finite element modeling of human spine. The fisrt method focuses on the detailed geometry and mechanical properties of spine, while the other complexities such as detailed muscle forces are overlooked. The latter... 

    Numerical Simulation and Investigation of Gas Explosion in the Confined Spaces

    , M.Sc. Thesis Sharif University of Technology Arjmand, Ali (Author) ; Farhanieh, Bijan (Supervisor)
    Abstract
    Generally speaking, there are two types of self-propagating combustion waves: deflagrations and detonations. deflagrations waves propagate at relatively low subsonic velocities with respect to the reactants ahead of it. The propagation velocity in deflagration wave is of order of 1 to 10 meters per second depend on laminar or turbulent regime. On the other hand, the detonation wave is a supersonic combustion wave (of the order of 2000 m/s) across which the thermodynamic states (e.g., pressure and temperature) increase sharply. It can be considered as a reacting shock wave where reactants transform into products, accompanied by an energy release across it. Due to drastic changes that... 

    3D Measurements of the Thoracic and Lumbar Spine Range of Motions Using Inertial Sensors

    , M.Sc. Thesis Sharif University of Technology Narimany, Mohammad (Author) ; Arjmand, Navid (Supervisor)
    Abstract
    Musculoskeletal abnormalities affect joints and change their range of motion (RoM). Correcting these abnormalities thoroughly depends on the information related to the normal spine movement. Therefore, spine motion analysis can be used as an important tool to distinguish between healthy and patient individuals as well as to determine the intensity of such diseases. Additionally, existing biomechanical models need kinematics data in order to analyze spinal forces. The present study hence aims to measure 3D range of motion of thoracic and lumbar spine using inertial sensors. Their small size, portability, low weight, and relatively low cost make inertial sensors as indispensable tools in... 

    A Novel Stability-based EMG-assisted Model of the Lumbar Spine to Estimate Trunk Muscle Forces and Spinal Loads in Various Static Activities

    , M.Sc. Thesis Sharif University of Technology Samadi, Soheil (Author) ; Arjmand, Navid (Supervisor)
    Abstract
    The spine like every other mechanical pillar, is exposed to buckling and loss of stability. While existing biomechanical models emphasize the pressure force on the disk as the main cause of injury, there is also a possibility of local buckling phenomenon in vertebral discs. Because of the prevalence and high cost of lower back pain, it is essential to evaluate the forces carried by disks and lumbar muscles during occupational activities more accurately. In this regard, hybrid EMG-assisted optimization (EMGAO) approaches are most common methods for estimation of spinal loads. These models, not only use EMG data to be physiologically creditable, but also satisfy equilibrium requirements at all... 

    Effect of Lumbar Spine Lordosis on Intervertebral Joint Load Sharing Using Musculoskeletal and Finite Element Modeling

    , M.Sc. Thesis Sharif University of Technology Havashinezhadian, Sara (Author) ; Arjmand, Navid (Supervisor)
    Abstract
    There is a large, at times contradictory body of investigations relating low back pain and spinal curvature in sagittal plane. The previous studies have not been subject-specified, and they have not considered the active tissues in the models. The mechanical load has a significant impact on the prevalence of low back pain and the geometry of lumbar spine in the sagittal plane is one of the most important characteristics in determining the load sharing of the spine. Thus, it is essential to know how the geometry load affects the load sharing of the lumbar spine. As a matter of fact, the purpose of this project is to know how the geometry of the lumbar spine affects the load sharing. Thus,...