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International Journal of Clinical Medicine 2018年第5期9卷 400-407页

作者： Farnoosh Razmara hamid mahmoodhashemi Shohreh Zahraei Ali Mahmoudhashemi Department of Oral and Maxillofacial Surgery Craniomaxillofacial Research Center Tehran University of Medical Sciences Tehran Iran Department of Pediatric Dentistry Dental Branch Islamic Azad University Tehran Iran Dentist Private Practice Tehran Iran

Aim: This study was performed to evaluate the movement of the proximal segment following different methods of ramus osteotomy that is one of the side effects of orthognathic surgery. Theoretically, with intraoral verticosagittal ramus osteotomy, it can minimize the movement of the proximal segment. The changes in the intergonal distance of mandible and the angle of the ramus flaring in two methods of osteotomy have been compared in this study. Materials and Methods: In this randomized clinical trial, included 60 patients (32 males) with mandibular prognathism and without any asymmetry were selected and divided into two groups (n = 30). One group underwent bilateral sagittal split ramus osteotomy technique to achieve mandibular setback and the other by the intraoral verticosagittal ramus osteotomy technique. Intergonial width and inner-ramal angle in the transverse plane were measured on radiographs preoperatively and 1 and 12 weeks postoperatively. Data were analyzed using covariance test with the significance level set at P 0.1). Conclusion: Considering our findings, there was no significant difference between two ramus osteotomy techniques regarding changes in mandibular width and inter-ramal flaring angle.

关键词： Bilateral Sagittal Split Ramus Osteotomy (BSSRO) Intraoral Verticosagittal Ramus Osteotomy (IVSRO) Intergonial Width Mandibular Prognathism Inter Ramal Angle

Vertical Ridge Augmentation of Atrophic Anterior Mandible with Autogenic Tibia Grafts Compared Allogenic Grafts

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International Journal of Clinical Medicine 2018年第7期9卷 580-589页

作者： Farnoosh Razmara hamid mahmoodhashemi Shohre Zahraei Ali Mahmoudhashemi Department of Oral and Maxillofacial Surgery Craniomaxillofacial Research Center Tehran University of Medical Sciences Tehran Iran Department of Oral and Maxillofacial Surgery Craniomaxillofacial Research Center Tehran University of Medical SciencesTehran Iran Department of Pediatric Dentistry Dental Branch Islamic Azad University Tehran Iran Dentist Private Practice Tehran Iran

Aim: Ridge augmentation for the atrophied mandible or for supporting dental implants is, an effective treatment in patients with alveolar defects that preserve bone height for the placement of implants or desirable appearance. Two common substans for bone augmentation are autografts and allografts. However, it is difficult to demonstrate that one surgical procedure offers better outcomes than another. Our study aimed to address and compare changes in ridge augmentation following autograft and allograft bone grafting within a 6-month follow up period. Materials and Methods: In a randomized blinded clinical trial, 18 patients who were candidates for mandible bone grafts were randomly divided into two autograft (tibia graft) (n = 9) and allograft (n = 9) groups. In the autograft group demineralized frozen dried bone was used. Height of three local points on graft replacement (Right, Middle and Left points) were measured based on the OPG preoperatively and also 3 and 6 months after the grafting. Results: In all patient, the trend of ridge augmentation change was significant within 6 months following grafting;however no difference was observed in height changes between the autograft and allograft procedures. Conclusion: From the clinical point of view, these two procedures appear to have similar efficacies for treating localized mandibular ridge defects. Clinical Significances: Comparison the success rate and increase the anterior of mandibular height between autogenous bone graft and allogeneic bone graft.

关键词： Ridge Ridge Augmentation Autografting Tibia Osteotomy

Temporal dynamics of neonatal hypoxic-ischemic encephalopathy injuries on magnetic resonance imaging

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Neural Regeneration Research 2025年第11期20卷 3144-3150页

作者： Holly Flyger Samantha J.Holdsworth Alistair J.Gunn Laura Bennet hamid Abbasi Mātai Medical Research Institute Tairāwhiti GisborneNew Zealand Department of Anatomy&Medical Imaging Faculty of Medical and Health SciencesThe University of AucklandAucklandNew Zealand Center for Brain Research The University of AucklandAucklandNew Zealand Auckland Bioengineering Institute The University of AucklandAucklandNew Zealand

Moderate to severe perinatal hypoxic-ischemic encephalopathy occurs in~1 to 3/1000 live births in high-income countries and is associated with a significant risk of death or neurodevelopmental *** assessment is important to help identify highrisk infants,to help families,and to support appropriate interventions.A wide range of monitoring tools is available to assess changes over time,including urine and blood biomarkers,neurological examination,and *** present,magnetic resonance imaging is unique as although it is expensive and not suited to monitoring the early evolution of hypoxic-ischemic encephalopathy by a week of life it can provide direct insight into the anatomical changes in the brain after hypoxic-ischemic encephalopathy and so offers strong prognostic information on the long-term outcome after hypoxic-ischemic *** review investigated the temporal dynamics of neonatal hypoxic-ischemic encephalopathy injuries,with a particular emphasis on exploring the correlation between the prognostic implications of magnetic resonance imaging scans in the first week of life and their relationship to long-term outcome prediction,particularly for infants treated with therapeutic hypothermia.A comprehensive literature search,from 2016 to 2024,identified 20 pertinent *** review highlights that while the optimal timing of magnetic resonance imaging scans is not clear,overall,it suggests that magnetic resonance imaging within the first week of life provides strong prognostic *** challenges limit the timing consistency,particularly the need for intensive care and clinical ***,although most reports examined the prognostic value of scans taken between 4 and 10 days after birth,there is evidence from small numbers of cases that,at times,brain injury may continue to evolve for weeks after *** suggests that in the future it will be important to explore a wider range of times after hypo

关键词： magnetic resonance imaging neonatal hypoxic-ischemic encephalopathy neurodevelopmental outcomes prognostic biomarkers in neuroimaging scan timing therapeutic hypothermia

A multiscale material model for heterogeneous liquid droplets in solid soft composites

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Frontiers of Structural and Civil Engineering 2021年第5期15卷 1292-1299页

作者： hamid GHASEMI Department of Mechanical Engineering Arak University of TechnologyArak 38181-41167Iran

Liquid droplets in solid soft composites have been attracting increasing attention in biological *** contrary with conventional composites,which are made of solid elastic inclusions,available material models for composites including liquid droplets are for highly idealized configurations and do not include all material real *** are also all deterministic and do not address the uncertainties arising from droplet radius,volume fraction,dispersion and *** research revisits the available models for liquid droplets in solid soft composites and presents a multiscale computational material model to determine their elastic moduli,considering nearly all relevant uncertainties and heterogeneities at different length *** effects of surface tension at droplets interface,their volume fraction,size,size polydispersity and agglomeration on elastic modulus,are *** micromechanical material models are incorporated into the presented computational *** results clearly indicate both softening and stiffening effects of liquid droplets and show that the model can precisely predict the effective properties of liquid droplets in solid soft composites.

关键词： liquid in solid soft composite computational modeling multiscale model heterogeneity

Molecular dynamics simulation of structure H clathrate-hydrates of binary guest molecules

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Journal of Natural Gas Chemistry 2011年第6期20卷 577-584页

作者： hamid Erfan-Niya hamid Modarress Department of Chemical Engineering Amirkabir University of Technology

Molecular dynamics （MD） simulations are performed to study the stability of structure H clathrate-hydrates of methane＋large-molecule guest substance （LMGS） at temperatures of 270, 273, 278 and 280 K under canonical （NVT-） ensemble condition in a 3×3×3 structure H unit cell replica with 918 TIP4P water molecules. The studied LMGS are 2-methylbutane （2-MB）, 2,3-dimethylbutane （2,3-DMB）, neohexane （NH）, methylcyclohexane （MCH）, adamantane and tert-butyl methyl ether （TBME）. In the process of MD simulation, achieving equilibrium of the studied system is recognized by stability in calculated pressure for NVT-ensemble. So, for the accuracy of MD simulations, the obtained pressures are compared with the experimental phase diagrams. Therefore, the obtained equilibrium pressures by MD simulations are presented for studying the structure H clathrate-hydrates. The results show that the calculated temperature and pressure conditions by MD simulations are consistent with the experimental phase diagrams. Also, the radial distribution functions （RDFs） of host-host, host-guest and guest-guest molecules are used to analysis the characteristic configurations of the structure H clathrate-hydrate.

关键词： structure H clathrate-hydrate methane+large-molecule guest substance molecular dynamics stability radial distribution function

Application of consistent geometric decomposition theorem to dynamic finite element of 3D composite beam based on experimental and numerical analyses

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Frontiers of Structural and Civil Engineering 2020年第3期14卷 675-689页

作者： Iman FATTAHI hamid Reza MIRDAMADI hamid ABDOLLAHI Department of Mechanical Engineering Isfahan University of TechnologyIsfahan ***Iran

Analyzing static and dynamic problems including composite structures has been of high significance in research efforts and industrial *** this article,equivalent single layer approach is utilized for dynamic finite element procedures of 3D composite beam as the building block of numerous composite *** this model,both displacement and strain fields are decomposed into cross-sectional and longitudinal components,called consistent geometric decomposition ***,the model is discretized using finite clement *** local coordinate systems and a global one are defined to decouple mechanical degrees of ***,from the viewpoint of consistent geometric decomposition theorem,the transformation and element mass matrices for those systems are introduced here for the first *** same decomposition idea can be used for developing element stiffiness ***,comprehensive validations are conducted for the theory against experimental and numerical results in two case studies and for various conditions.

关键词： composite beam dynamic finite element degrees of freedom coupling experimental validation numerical validation

Coal pillar mechanics of violent failure in U.S. Mines

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International Journal of Mining Science and Technology 2017年第3期27卷 387-392页

作者： Maleki hamid Maleki Technologies Inc. Spokane WA 99223 USA

This paper seeks to enhance the understanding that the horizontal stresses build up and release during coal pillar loading and unloading(post-failure) drawing upon three decades of observations, geomechanical monitoring and numerical modeling in bump-prone U.S. mines. The focus is on induced horizontal stress in mine pillars and surrounding strata as highly stressed pillars punch into the roof and floor, causing shear failure and buckling of strata; under stiff stratigraphic units of some western US mines, these events could be accompanied by violent failure of pillar cores. Pillar punching eventually results in tensile stresses at the base of the pillar, facilitating transition into the post-failure regime; this transition will be nonviolent if certain conditions are met, notably the presence of interbedded mudstones with low shear strength properties and proper mine designs for controlling seismicity and dynamic loads. The study clearly shows high confining stress build-up in coal pillars resulting in up to twice higher peak vertical stress and high strain energy accumulations in some western US mines in comparison with peak stresses predicted using common empirical pillar design methods. It is the unstable release of this strain energy that can cause significant damage resulting from pillar dilation and ground movements. These forces are much greater than the capacity of most common internal support systems, resulting in horizontal stressinduced roof falls locally, in mines under unremarkable far-field horizontal stress. Attention should be placed on pillar designs as increasing support density may prove to be ineffective. This mechanism is analyzed using field measurements and generic finite-difference stress analyses. The study confirms the higher load carrying capacity of confinement-controlled coal seams in comparison with structurally controlled coal seams. Such significant differences in confining stresses are not taken into account when estimating peak pil

关键词： Rockburst and coal bumps Field measurements Stress analysis Mechanics Horizontal stress

Parallel resonance type fault current limiting circuit breaker

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High Voltage 2020年第1期5卷 76-82页

作者： hamid Radmanesh Seyed hamid Fathi Electrical Engineering Department Shahid Sattari Aeronautical University of Science and TechnologyTehranIran Electrical Engineering Department Amirkabir University of TechnologyTehranIran

The main goal of this study is introducing a novel fault current limiter based on parallel resonance structure(PRFCL)for high voltage *** normal mode,the PRFCL reactor is short-circuited via a rectifier bridge DC output voltage and LC resonance tank shows negligible impedance in the *** a fault,the rectifier bridge switches are turned off,so that the parallel resonance LC tank connects to the line with high *** impedance of the resonance structure can limit the fault current,*** is shown that the suggested PRFCL can act as a breaker and opens the line during the fault *** order to show the suggested PRFCL abilities,MATLAB software is used to simulate the normal and fault *** addition,a scale-down prototype is implemented to confirm the simulation *** comparative study shows that PRFCL has acceptable performance in normal and current limiting operation modes.

关键词： period fault limiting

Effect of metal oxide arrester on the chaotic oscillations in the voltage transformer with nonlinear core loss model using chaos theory

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Chinese Physics B 2014年第1期23卷 480-488页

作者： hamid Reza Abbasi habbasi@iust.ac.ir Amirkabir University Electrical Engineering Department Tehran 64540 Iran

In this paper, controlling chaos when chaotic ferroresonant oscillations occur in a voltage transformer with nonlin- ear core loss model is performed. The effect of a parallel metal oxide surge arrester on the ferroresonance oscillations of voltage transformers is studied. The metal oxide arrester （MOA） is found to be effective in reducing ferroresonance chaotic oscillations. Also the multiple scales method is used to analyze the chaotic behavior and different types of fixed points in ferroresonance of voltage transformers considering core loss. This phenomenon has nonlinear chaotic dynamics and includes sub-harmonic, quasi-periodic, and also chaotic oscillations. In this paper, the chaotic behavior and various ferroresonant oscillation modes of the voltage transformer is studied. This phenomenon consists of different types of bifur- cations such as period doubling bifurcation （PDB）, saddle node bifurcation （SNB）, Hopf bifurcation （HB）, and chaos. The dynamic analysis of ferroresonant circuit is based on bifurcation theory. The bifurcation and phase plane diagrams are il- lustrated using a continuous method and linear and nonlinear models of core loss. To analyze ferroresonance phenomenon, the Lyapunov exponents are calculated via the multiple scales method to obtain Feigenbaum numbers. The bifurcation diagrams illustrate the variation of the control parameter. Therefore, the chaos is created and increased in the system.

关键词： ferroresonance chaos theory metal oxide arrester Lyapunov exponent

Assessment of fracture process in forta and polypropylene fiber-reinforced concrete using experimental analysis and digital image correlation

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Frontiers of Structural and Civil Engineering 2022年第12期16卷 1633-1652页

作者： Seyed hamid KALALI hamid ESKANDARI-NADDAF Seyed Ali EMAMIAN Department of Civil Engineering Hakim Sabzevari UniversitySabzevar ***Iran

This paper aims to characterize the evolution of the fracture process and the cracking behavior in fortaferro(FF)and polypropylene(PP)fiber-reinforced concrete under the uniaxial compressive loading using experimental analysis and digital image correlation(DIC)on the surface *** this purpose,6 mix designs,including two FF volume fractions of 0.10%,and 0.20%and three PP volume fractions of 0.20%,0.30%,and 0.40%,in addition to a control mix were evaluated according to compressive strength,modulus of elasticity,toughness index,and stress–strain *** influence of fibers on the microstructural texture of specimens was analyzed by scanning electron microscope(SEM)*** show that FF fiber-reinforced concrete specimens demonstrated increased ductility and strength compared to PP *** results revealed that the major crack and fracture appeared at the peak load of the control specimen due to brittleness and sudden gain of large lateral strain,while a gradual increase in micro-crack quantity at 75%of peak load was observed in the fiber specimens,which thenbegan to connect with each other up to the final *** accuracy of the results supports DIC as a reliable alternative for the characterization of the fracture process in fiber-reinforced concrete.

关键词： fiber-reinforced concrete forta-ferro and polypropylene fiber fracture process cracking behavior digital image correlation