Papers by Mohamad Sadeghi
Investigation on the effect of anti-pitch fins for reducing the motion and acceleration of ships using computational fluid dynamics
Ocean Engineering
Iranian Journal of Chemistry & Chemical Engineering-international English Edition, Oct 1, 2019
In this paper, the synthesis of new montmorillonite nanocomposite hydrogel (MMTNH) based on poly ... more In this paper, the synthesis of new montmorillonite nanocomposite hydrogel (MMTNH) based on poly (acrylic acid-co-acrylamide) grafted onto starch, is described. Montmorillonite (MMT) as nanometer base, acrylic acid (AA) and acrylamide (AAm) as monomers, ammonium persulfate (APS) as an initiator, N,N-methylenebisacrylamide (MBA) as a crosslinker and starch as a biocompatible polymer were prepared in aqueous solution and their amounts were optimized to attain the highest water absorbance. The optimized swelling capacity in distilled water was found to be 810 g/g. A mechanism for hydrogel formation was proposed and the structure of the product was confirmed using a set of techniques including FT-IR spectroscopy, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, and X-ray powder diffraction. Furthermore, the swelling behaviors of the nanocomposite at different pHs, various salt with different concentrations, the mixture of solvents, were investigated. The methylene blue (MB) dye was used as model drugs to assess the loading and release by MMTNH. The pH response of this MMTNH makes it suitable for acting as a controlled delivery system. The results suggest MMTNH may find applications as promising drug delivery vehicles for drug molecules.
Segmentation of lip pixels for lip tracker initialisation
Proceedings 2001 International Conference on Image Processing (Cat. No.01CH37205)
Centre for Vision, Speech and Signal Processing School of Electronics, Computing and Mathematics ... more Centre for Vision, Speech and Signal Processing School of Electronics, Computing and Mathematics University of Surrey, Guildford GU2 7XH, UK Email: M.Sadeghi, J.Ki ttler,K.Messer 0 eim.sun-ey.ac .uk ... ABSTRACT We propose a novel image segmentation method for lip ...
In this work, Acrylic Acid modified Styrene butadiene (SBR-g-AA)/segmented polyurethane (PU) blen... more In this work, Acrylic Acid modified Styrene butadiene (SBR-g-AA)/segmented polyurethane (PU) blends were prepared. SBR has been modified using AA in the presence of benzoyl peroxide via bulke radical polymerization. Then ester-ether based polyurethane mixed with modified SBR using an internal mixer in various weight ratio of AA to SBR. Then blend of modified SBR/PU with weight ratio of 70/30 have been prepared and analytical techniques such as attenuated total reflectance infrared Fourier transform spectrometry (ATR-FTIR), dynamic mechanical thermal analysis (DMTA), tensile tests, Scanning electron microscopy (SEM), contact angle analysis and Water absorption were used to characterize the blend. ATR-FTIR and DMTA were used to confirm grafting of AA o SBR chains and then DMTA was used to qualitative analysis of grafting process. According to FTIR-ATR analysis, the peak at 1711 Cm-1 band due to carbonyl groups of AA shifted to 1736 Cm -1 in grafted SBR. DMTA results show change in AA ...
Thermoplastic polyurethane (TPU)/clay nanocomposites were prepared via a melt-compounding method ... more Thermoplastic polyurethane (TPU)/clay nanocomposites were prepared via a melt-compounding method using ester type TPU and two different modified organoclays (Cloisite 30B and Cloisite 15A) in different contents. The Effects of the chemical structure and content of the nanoclays on the thermal degradation and mechanical properties of TPU were also investigated. The effect of structural modification on dispersion during melt compounding has been studied by XRD and FTIR analysis. Barrier effect formation and thermal stability in both nanocomposites containing different nanoparticle content have been studied. The effect of chemical modification of the nanoparticles on mechanical properties in all contents has been investigated. The XRD results show that better dispersion near the exfoliated structure obtained for cloisite 30B is due to good interaction via hydrogen bonding between the TPU chains and layered silicate. A high content of the nanoparticles leads to disordering of soft and h...
Applied Ocean Research, 2020
Reducing ship's roll motion has always been a major concern in ship design. In the present study,... more Reducing ship's roll motion has always been a major concern in ship design. In the present study, the effect of the angle of a canted rudder system on roll damping of a twin-screw naval vessel has been investigated by using a RANS solver. Moreover, the influence of forward speeds, initial inclination angle, as well as viscosity are also taken into account. For this purpose, free roll decay test is simulated. Besides, numerical validation and verification are performed based on the procedures proposed by the ITTC. The simulation results are then compared with experimental data with regard to an acceptable agreement between them. Based on the results an approximate relation was extracted for calculating roll damping ratio as a function of rudder vertical angle and Froude number. It can be concluded that the roll damping increases, especially for higher forward speeds, as the angle of the canted rudder system increases.
Journal of Research Updates in Polymer Science, 2012
We have developed a new hydrocolloid impression gel to eliminate disinfection process that caused... more We have developed a new hydrocolloid impression gel to eliminate disinfection process that caused to inaccuracy in dimensions of final mold. At first, the proper sample has been prepared based on recommended formulation in literature as well as trial and errors via experimental works. Formulations prepared by variation amounts of ingredients and also samples prepared by adding nanosilver as an antibacterial agent. Characteristic properties such as tear strength, gel temperature, compressive strength and elastic recovery of prepared hydrocolloid impression gels have been evaluated. The effect of agar, potassium sulfate and di-sodiumtetraborate (Borax) on characteristic properties has been investigated. In addition, role of nanosilver as an antibacterial which can be eliminate disinfecting process, on final properties of gels has been evaluated this work presents the role of ingredient on properties of self disinfecting agar impression gel.
Novel Crosslinked Graft Copolymer of Methacrylic Acid and Collagen as a Protein-Based Superabsorbent Hydrogel with Salt and PH-Responsiveness Properties
AIP Conference Proceedings, 2008
In this paper, a novel protein-based superabsorbent hydrogel was synthesized through crosslinking... more In this paper, a novel protein-based superabsorbent hydrogel was synthesized through crosslinking graft copolymerization of methacrylic acid (MAA) onto collagen, using ammonium persulfate (APS) as a free radical initiator in the presence of methylenebisacrylamide (MBA) as a crosslinker. The hydrogel structure was confirmed using FTIR spectroscopy. We were systematically optimized the certain variables of the graft copolymerization (i.e. the monomer, the initiator, and the crosslinker concentration) to achieve a hydrogel with maximum swelling capacity. Under the optimized conditions concluded, maximum capacity of swelling in distilled water was found to be 415 g/g. The swelling kinetics of the synthesized hydrogels with various particle sizes was preliminarily investigated. Absorbency in aqueous chloride salt solutions indicated that the swelling capacity decreased with an increase in the ionic strength of the swelling medium. The swelling of superabsorbing hydrogels was also measured in solutions with pH ranged from 1 to 13. The synthesized hydrogel exhibited a pH-responsiveness character so that a swelling-collapsing pulsatile behavior was recorded at pHs 2 and 7. This behavior makes the synthesized hydrogels as an excellent candidate for controlled delivery of bioactive agents.
Teaching Vocabulary through Word Formation Strategies among Iranian Intermediate EFL Students
We address the problem of fusing colour information for face authentication. The performance of a... more We address the problem of fusing colour information for face authentication. The performance of a face verification system in different colour spaces is experimentally studied first. The verification process is based on the normalised correlation measure within the LDA feature space. A sequential search approach which is in principle similar to the "plus L and take away R" algorithm is then applied in order to find an optimum subset of the colour spaces. Using the proposed method, the performance of the system is considerably improved as compared to the intensity space. The proposed colour fusion scheme also outperforms the best colour space in different conditions.
Evaluation of facial soft tissue parameters for North-west students in Iran
Application of genomic and proteomic technologies in biomarker discovery
American Society of Clinical Oncology educational book / ASCO. American Society of Clinical Oncology. Meeting, 2012
Sequencing of the human genome was completed in 2001. Building on the technology and experience o... more Sequencing of the human genome was completed in 2001. Building on the technology and experience of whole-exome sequencing, numerous cancer genomes have been sequenced, including head and neck squamous cell carcinoma (HNSCC) in 2011. Although DNA sequencing data reveals a complex genome with numerous mutations, the biologic interaction and clinical significance of the overall genetic aberrations are largely unknown. Comprehensive analyses of the tumors using genomics and proteomics beyond sequencing data can potentially accelerate the rate and number of biomarker discoveries to improve biology-driven classification of tumors for prognosis and patient selection for a specific therapy. In this review, we will summarize the current genomic and proteomic technologies, general biomarker-discovery paradigms using the technology and published data in HNSCC-including potential clinical applications and limitations.
Leprosy in Iran: an analysis of 195 cases from 1994-2009
JPMA. The Journal of the Pakistan Medical Association, 2011
To estimate the prevalence of Leprosy in Azerbaijan, Iran. A total of 195 new leprosy cases refer... more To estimate the prevalence of Leprosy in Azerbaijan, Iran. A total of 195 new leprosy cases referred to and registered in Bababaghi Center, Azerbaijan, Northwest of Iran from 1994-2009 were studied. Of the 195 new cases, 131 (67/2%) were males and 64 (32/8%) females. They were born in Azerbaijan with the peak age of the disease at their fourth decade. The most common form of the disease, especially in male patients, was lepromatous leprosy. Skin problems, especially eyebrow hair loss, constituted the most frequent sign of the disease. The most involved nerve was ulnar nerve. Although, leprosy is a rare disease in Iran it is still encountered. It is important for the physicians to be aware of its diagnosis when they see a patient with chronic dermatitis and peripheral nerve involvement.
AFM, SPM, STM and TEM Techniques: Brilliant Techniques in Characterization of Block Copolymer Self-Assembly Nanostructures
Techniques such as AFM, SPM, ATM and TEM will be discussed in this chapter. At first principles o... more Techniques such as AFM, SPM, ATM and TEM will be discussed in this chapter. At first principles of techniques will be presented. Then a short summary about how to use these techniques to characterize self-assembly nanostructures based on block copolymers. Thin film morphology of semicrystalline BCPs and control of the thin film morphology through crystallization-related technologies could be studied by AFM. For example a fingerprint-like pattern, with a domain spacing of ~40 nm could be seen for polystyrene-b-poly (4-vinylpyridine) by using of SPM height and phase images of a thin film ~47 nm in thickness after annealing in solvent. Some example about using of the techniques will be presented. Block copolymers are useful in many applications where a number of different polymers are connected together to yield a material with hybrid properties. For example, thermoplastic elastomers are block copolymers containing a rubbery matrix (polybutadiene or polyisoprene) and glassy hard domain...
The comparative study in treatment of solar lentigines with trichloroacetic acid 40% vs. cryotherapy
VOL. 24 NO. 5 • MAY 2011 • Cosmetic Dermatology 215 www.cosderm.com C haracteristic features of p... more VOL. 24 NO. 5 • MAY 2011 • Cosmetic Dermatology 215 www.cosderm.com C haracteristic features of photoaging skin are sallowness mottled pigmentation, dry and rough skin, loss of skin tone, leathery texture, laxity, coarse and fine wrinkles, benign and malignant tumors, and solar lentigines.1,2 Solar lentigo is local and benign proliferation of melanocytes at the dermoepidermal junction. These lesions are several yellow or brown ovals or round maculae with obvious margins created at the areas such as back of the hands, forearm, and face, which are exposed to sunlight.3 Maculae can also be regarded as the first signs of the photoaging process, which can also have a substantial impact on patients. The incidence increases with age, affecting more than 90% of white persons older than 50 years of age. In the differential diagnosis, solar lentigines should be distinguished from ephelides, lentigo simplex, pigmented actinic keratosis, flat seborrheic keratosis, melanocytic nevus, and malignant melanoma. These can be differentiated based on clinical appearance.4 Considering that solar lentigo is A Comparative Study in the Treatment of Solar Lentigines With Trichloroacetic Acid 40% Versus Cryotherapy
Proceedings - International Conference on Pattern Recognition, 2004
This paper details the results of a Face Authentication Test (FAT2004) [5] held in conjunction wi... more This paper details the results of a Face Authentication Test (FAT2004) [5] held in conjunction with the 17th International Conference on Pattern Recognition. The contest was held on the publicly available BANCA database [1] according to a defined protocol [7]. The competition also had a sequestered part in which institutions had to submit their algorithms for independent testing. 13 different verification algorithms from 10 institutions submitted results. Also, a standard set of face recognition software packages from the Internet [2] were used to provide a baseline performance measure.
Polymer, 2015
A novel method including combined use of nanoparticles and non-solvent is proposed for fabricatio... more A novel method including combined use of nanoparticles and non-solvent is proposed for fabrication of superhydrophobic polystyrene coatings. The proposed method results in utterly homogeneous and mechanically stable coatings with excellent adhesion to the substrate as compared to the other commonly used solution-based methods. It is proved that individual use of nanoparticles and non-solvent could lead to superhydrophobic behavior but at the price of adding very high contents. Based on water contact angle results, the proposed method causes a significant reduction in the required contents of nanoparticles (150 wt% to 20 wt% with respect to the polymer) and non-solvent (33 vol% to 9-16 vol%) for achieving superhydrophobicity. A thorough investigation of surface composition and morphology is also conducted via X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), respectively. Moreover, a different approach is employed for evaluation of surface topography using diverse roughness parameters. It was found that a combination of roughness parameters should be considered for a proper surface analysis instead of only using average roughness and root mean square. It was also demonstrated that the surface roughness uniformity is another key factor to achieve a self-cleaning behavior.
Comparison of microtia reconstructive surgery with autograft versus homograft
Archives of Iranian medicine, 2007
Microtia is a congenital abnormality with low incidence but considerable morbidities. Reconstruct... more Microtia is a congenital abnormality with low incidence but considerable morbidities. Reconstruction of the microtia deformity is a complex and difficult process that requires a proper planning. The primary technique of reconstruction employs patient's own rib cartilage. Irradiated homograft cartilages previously have been used in facial reconstruction but its application in microtia surgery has not been reported yet. This study is designed to compare the results of autograft versus homograft auriculoplasty. Between 1992 - 2002, 23 patients underwent auricular reconstructive surgery by the senior author in our department. Autograft implantation was performed in one stage but homograft auriculoplasty was done in two stages. Auricular deformity was right-sided in 13, left-sided in 8, and bilateral in 2 cases. Implanted graft was autograft in 9 patients and homograft in 14 patients. During mean follow-up of 4 years, cartilage graft resorption was detected in two cases, one in autog...
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Papers by Mohamad Sadeghi