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Critical Buckling load Analysis of Truck Chassis Using Arclength Method

Ehsan Hedayati, Arefeh Hedayati, Mohammad Vahedi
2015 Maǧallaẗ al-abḥāṯ al-handasiyyaẗ  
doi:10.7603/s40632-015-0018-3 fatcat:batcmfexsvfzfncdcmipfvjyvy

Burden of fungal infections in Iran

Mohammad T Hedayati, Mojtaba Tagizadeh Armaki, Jamshid Yazdani Charati, Newsha Hedayati, Seyedmojtaba Seyedmousavi, David W Denning
2018 Journal of Infection in Developing Countries  
According to the only investigation on CPA in Iran by Hedayati et al. [50] , the incidence of CPA in TB patients was 11.3%.  ... 
doi:10.3855/jidc.10476 pmid:32004161 fatcat:5bftbajl75bd3fnslxkwk2uvgq

Microplastics in Marine Ecosystems

Aliakbar Hedayati, Mohammad Gholizadeh, Tahereh Bagheri, Safoura Abarghouei, Wahid Zamani
2022 Zenodo  
Large plastic debris is broken down into smaller pieces by different mechanisms such as weathering, light degradation and biodegradation, eventually turning into microplastics (˂ 5 mm). Microplastics can also enter the marine ecosystems directly via rivers, waste discharges, and the dumping of waste by the people. Marine organisms are directly and indirectly exposed to accidental feeding from microplastics. Microplastics, apart from the physical effects of being consumed by living organisms,
more » ... be a carrier of contaminants to be absorbed. Numerous studies have reported pollutants can be absorbed by microplastics and enriched in seas and oceans. Therefore, the study of the presence, distribution and accumulation of microplastics in aquatic ecosystems can create a comprehensive model in the integrated management of these emerging pollutants. In this study the origin, fate and behavior of microplastics in marine ecosystems was examined to determine the sources of microplastics in these ecosystems and their effects on living organisms and trophic transmission."
doi:10.5281/zenodo.7033633 fatcat:osnnnwlx5jhhhfbebhld6tvwqu

Microplastics in Marine Ecosystems

Aliakbar Hedayati, Mohammad Gholizadeh, Tahereh Bagheri, Safoura Abarghouei, Wahid Zamani
2022 Zenodo  
., Hedayati, A., Raeisi, M., Hadavand, B.S., Rezaei, H. and Abed-Elmdoust, A. (2021) .  ... 
doi:10.5281/zenodo.7038554 fatcat:476jjjspvbhatpjpmn6nu3jb44

Aspergillus species in indoor environments and their possible occupational and public health hazards

Bita Mousavi, Mohammad T Hedayati, Newsha Hedayati, Macit Ilkit, Seyedmojtaba Syedmousavi
2016 Current Medical Mycology  
The genus Aspergillus, which consists of a few hundred opportunistic mold species found in various climatic conditions, causes diseases including localized infections, fatal diseases, allergic responses, and inhaled conidia in humans. Herein, we present an overview of the most common diseases and allergic infections caused by Aspergillus species and their associated health hazards in various indoor environments worldwide.
doi:10.18869/acadpub.cmm.2.1.36 pmid:28681011 pmcid:PMC5490296 fatcat:ynb2lw2omrc5zpe5jxpyh3qhly

Understanding and Optimizing Persistent Memory Allocation [article]

Wentao Cai, Haosen Wen, H. Alan Beadle, Chris Kjellqvist, Mohammad Hedayati, Michael L. Scott
2020 arXiv   pre-print
The proliferation of fast, dense, byte-addressable nonvolatile memory suggests that data might be kept in pointer-rich "in-memory" format across program runs and even process and system crashes. For full generality, such data requires dynamic memory allocation, and while the allocator could in principle "rolled into" each data structure, it is desirable to make it a separate abstraction. Toward this end, we introduce recoverability, a correctness criterion for persistent allocators, together
more » ... h a nonblocking allocator, Ralloc, that satisfies this criterion. Ralloc is based on the LRMalloc of Leite and Rocha, with three key innovations. First, we persist just enough information during normal operation to permit correct reconstruction of the heap after a full-system crash. Our reconstruction mechanism performs garbage collection (GC) to identify and remedy any failure-induced memory leaks. Second, we introduce the notion of filter functions, which identify the locations of pointers within persistent blocks to mitigate the limitations of conservative GC. Third, to allow persistent regions to be mapped at an arbitrary address, we employ position-independent (offset-based) pointers for both data and metadata. Experiments show Ralloc to be performance-competitive with both Makalu, the state-of-the-art lock-based persistent allocator, and such transient allocators as LRMalloc and JEMalloc. In particular, reliance on GC and offline metadata reconstruction allows Ralloc to pay almost nothing for persistence during normal operation.
arXiv:2003.06718v1 fatcat:x4ig7vil2zd5tkmsqnxe7r6pye

Modeling the Corona Virus Outbreak in IRAN [article]

Maryam Moghadami, Maryam Moghadami, Mohammad Hassanzadeh, ka wa, Aziz Hedayati, Mila Malekolkalami
2020 medRxiv   pre-print
As the outbreak of coronavirus disease 2019 (COVID19) is a worldwide pandemic it is rapidly expanding in Iran realtime analyses of epidemiological data are needed to increase situational awareness and inform interventions. In this study we built a predictive model based on the cumulative trend of new cases and deaths for the top five provinces. we will also look at modeling the trends for confirmed cases deaths and recovered for the whole country. Method: In this study we have chosen to apply
more » ... e exponential smoothing model to iteratively forecast future values of a regular time seires from weighted averages of past daily values of the series. This method is exponential because the value of each level is influenced by every preceeding actual value to an exponentially decreasing degree more recent values are given a greater weight. The available data is too small to identify seasonal patterns and make predictable variation in value, such as annual fluctuation in temperature relative to the season. Trend is a tendency in the data to increase or decrease over time. Results: If no control measures are put in place it is expected that over 40000 would be infected in Tehran around the middle of June. However if control measures were implemented with a high degree of success one would expect the spread of the COV19 virus would peak at the start of April with a downward trend dropping off by the end of May (70 days). In the scenario that no further measures are implemented, one would expect the spread of COVID19 to continue on a gentle incline reaching 21000 by mid-June. The same process has been applied to review the confirmed deaths and recovered dataset. The forecast has been carried out for the next 30 days a shorter timeframe has been selected as there is a high probability that the Iranian New Years celebration Farvardin first month of Spring (30th March in Western calendar) will have an impact on the infection rate following the event. The best predictive model predicts the confirmed cases to be in the range of 35000 70000 with the number of reported COVDI-19 deaths to be between 3000 5000 and 5000 30000 of recovered cases. Conclusions: Modeling outbreak ofCovid19 shows that the number of patients and deaths is still increasing. Contagious diseases follow an exponential model and the same be Haves this one. This is because the virus can spread to others and finally each person turns into a carrier of the virus and transmit it to another person. Disease control depends on disconnection and social distancing. In addition many factors are effective in stopping the disease. These include citizens participation in the prevention process health education the effectiveness of instructive traditions environmental conditions and so on.
doi:10.1101/2020.03.24.20041095 fatcat:h2qqn3i35jdj3jpuqndijjy3gq

Multi-Queue Fair Queuing

Mohammad Hedayati, Kai Shen, Michael L. Scott, Mike Marty
2019 USENIX Annual Technical Conference  
The source code for our implementation is available at  ... 
dblp:conf/usenix/HedayatiSSM19 fatcat:4f4d7dr2mze6xjzoglmeod46cu

Mechanical Properties of Additively Manufactured Thick Honeycombs

Reza Hedayati, Mojtaba Sadighi, Mohammad Mohammadi Aghdam, Amir Zadpoor
2016 Materials  
Honeycombs resemble the structure of a number of natural and biological materials such as cancellous bone, wood, and cork. Thick honeycomb could be also used for energy absorption applications. Moreover, studying the mechanical behavior of honeycombs under in-plane loading could help understanding the mechanical behavior of more complex 3D tessellated structures such as porous biomaterials. In this paper, we study the mechanical behavior of thick honeycombs made using additive manufacturing
more » ... niques that allow for fabrication of honeycombs with arbitrary and precisely controlled thickness. Thick honeycombs with different wall thicknesses were produced from polylactic acid (PLA) using fused deposition modelling, i.e., an additive manufacturing technique. The samples were mechanically tested in-plane under compression to determine their mechanical properties. We also obtained exact analytical solutions for the stiffness matrix of thick hexagonal honeycombs using both Euler-Bernoulli and Timoshenko beam theories. The stiffness matrix was then used to derive analytical relationships that describe the elastic modulus, yield stress, and Poisson's ratio of thick honeycombs. Finite element models were also built for computational analysis of the mechanical behavior of thick honeycombs under compression. The mechanical properties obtained using our analytical relationships were compared with experimental observations and computational results as well as with analytical solutions available in the literature. It was found that the analytical solutions presented here are in good agreement with experimental and computational results even for very thick honeycombs, whereas the analytical solutions available in the literature show a large deviation from experimental observation, computational results, and our analytical solutions. Materials 2016, 9, 613 2 of 23 mechanically and biologically when used as the micro-architecture of bone replacing scaffolds [2, 3] . Singh showed that in some areas (where bone is very dense), cancellous bone microarchitecture resembles that of a hexagonal honeycomb with thick cell walls [4] . Hexagonal honeycombs or honeycomb-like structures have been manufactured as biomedical implants using different additive manufacturing techniques [5, 6] . Recently, various cells have been successfully cultured in collagen scaffold honeycombs [7] [8] [9] . It is important to study the mechanical behavior of thick honeycomb-like structures, because the mechanical properties of the biomaterials used for tissue regeneration could significantly influence the tissue regeneration performance of biomaterials. The mechanical properties of honeycombs (such as their stiffness and yield stress) in out-of-plane direction are usually much higher compared to their in-plane properties. This is why more studies have been devoted to the investigation of out-of-plane properties of honeycombs compared to their in-plane properties. However, honeycombs are loaded in-plane in a number of natural structures such as cancellous bone, wood, and cork [10] . Moreover, thick honeycombs could be also useful for energy absorption purposes in the in-plane direction. In this case, the mechanism dominating the structure deformation is bending of the cell walls (rather than sudden buckling of the walls which is common in the out-of-plane deformations of honeycombs) and then face-to face crushing of the cell walls. This can lead to a smoother stress-strain curve with higher energy absorption capacity as compared to the out-of-plane direction, if the geometrical parameters are chosen properly. Several experimental works have been carried out on the in-plane deformation of honeycombs. Foo et al. [11] obtained linear elastic mechanical properties of Nomex™ honeycomb structures using extensive test programs and compared their results with those of their finite element (FE) models. They observed size effects for the moduli of Nomex™ honeycombs. Papka and Kyriakides [12] compressed honeycomb specimens between stiff flat grips experimentally and numerically. They found out that although the crushing patterns developed during the plateau regime differs from specimen to specimen (caused by specimen size and geometric imperfections), the cell failure mechanism is similar for all cases. Other experimental works on the in-plane mechanical behavior of honeycombs can be found in [13] [14] [15] [16] [17] . Several numerical studies have also been carried out using FE methods the most important of which are in the following references [18] [19] [20] . El-Sayed et al. [21] published the first analytical study on the in-plane mechanical properties of hexagonal honeycombs in which the elastic mechanical properties of a composite under in-plane axial and out-of-plane bending loads were studied, and the plastic deformation properties under in-plane axial loading were characterized. However, as stated in [10], their work had 'numerous small errors' which rendered the results unreliable. In 1982, Gibson et al. [10] presented improved analytical relationships for the mechanical properties of hexagonal honeycombs (E 1 , E 2 , υ 12 , υ 21 , σ y1 , σ y2 , G, and σ el ). Their results showed good agreement with their experimental results for both rubber and metal honeycombs but only for very small values of wall thickness and relative density. Masters and Evans [22] developed an analytical model for prediction of elastic constants of honeycombs by decomposing the general deformation of a honeycomb cell into flexural, stretching, and hinging parts. For each of the three mechanisms, force constants were defined while relationships for E 1 , E 2 , υ 12 , υ 21 , and G were calculated. The elastic constants calculated from each mechanism were then superimposed to give a general model [23] . Masters and Evans [22] did not obtain any relationship for yield stress. Goswami [24] derived analytical formulas for the elastic properties of hexagonal honeycomb cores. Elemental beam theory was used for each component inside the unit cell to give different elastic properties by means of strain energy concept. The results of their model coincided with the results reported in [10] . Balawi and Abot [25] presented a modified model for commercial hexagonal honeycombs having double wall thickness in vertical walls and some curvature in the neighborhood of cell vertices caused by expansion or corrugation processes during manufacturing. In all of the above-mentioned works, the Euler-Bernoulli beam theory is the theoretical basis for deriving the analytical relationships. The analytical solutions obtained using the Euler-Bernoulli beam theory are not applicable to thick honeycombs, because a number of simplifying assumptions are used
doi:10.3390/ma9080613 pmid:28773735 pmcid:PMC5509007 fatcat:dvh3zkxcr5blvgau2a2jk5weci


Mohammad T. Hedayati, Sadegh Khodavaisy, Masoud Alialy, Saeed Mahdavi Omran, Mohammad R. Habibi
2013 Acta Medica  
We assessed the intensive care unit (ICU) patients for Invasive aspergillosis (IA) with culture and non-culture based diagnostic methods from Iran. Thirty-six ICU patients with underlying predisposing conditions for IA were enrolled in the study. Sixty eight Bronchoalveolar lavage (BAL) samples were collected by bronchoscope twice a weekly. BAL samples were analyzed by microscopic examination, fungal culture and galactomannan (GM) detection. The Platelia Aspergillus GM EIA was used to quantify
more » ... M indices. Samples with a BAL GM index ≥1 were considered as positive for GM. Patients were classified as having probable or possible IA. Out of 36 suspected patients to IA, 36.1% of cases showed IA which were categorized as: 4 cases of possible IA and 9 of probable IA. 76.2% of BAL samples were positive for GM. From 13 patients with IA, 11 (84.6%) had at least one positive BAL GM index. Of these patients, 9 (81.8%) showed probable IA. The main underlying predisposing conditions were neutropenia (53.8%) and COPD (30.8%). Our study has indicated that COPD must be considered as one of the main predisposing condition for occurrence of aspergillosis in ICU patients. Our data have also revealed that GM detection in BAL samples play a significant role to IA diagnosis.
doi:10.14712/18059694.2014.24 pmid:24069658 fatcat:wcg7qi6zufhxjibwmusvlfplj4

GPU Taint Tracking

Ari B. Hayes, Lingda Li, Mohammad Hedayati, Jia-Huan He, Eddy Z. Zhang, Kai Shen
2017 USENIX Annual Technical Conference  
Dynamic tainting tracks the influence of certain inputs (taint sources) through execution and it is a powerful tool for information flow analysis and security. Taint tracking has primarily targeted CPU program executions. Motivated by recent recognition of information leaking in GPU memory and GPU-resident malware, this paper presents the first design and prototype implementation of a taint tracking system on GPUs. Our design combines a static binary instrumentation with dynamic tainting at
more » ... ime. We present new performance optimizations by exploiting unique GPU characteristics-a large portion of instructions on GPU runtime parameters and constant memory can be safely eliminated from taint tracking; large GPU register file allows fast maintenance of a hot portion of the taint map. Experiments show that these techniques improved the GPU taint tracking performance by 5 to 20 times for a range of image processing, data encryption, and deep learning applications. We further demonstrate that GPU taint tracking can enable zeroing sensitive data to minimize information leaking as well as identifying and countering GPU-resident malware.
dblp:conf/usenix/HayesLHHZS17 fatcat:bttqbasiqzdsdkvfi7i2sndsdy

First Autochthonous Coinfected Anthrax in an Immunocompetent Patient

Parvaneh Afshar, Mohammad Taghi Hedayati, Narges Aslani, Sadegh Khodavaisy, Farhang Babamahmoodi, Mohammad Reza Mahdavi, Somayeh Dolatabadi, Hamid Badali
2015 Case Reports in Medicine  
Hedayati was financially supported by the School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran. I. Haghani is acknowledged for help in building up part of the sequence database.  ... 
doi:10.1155/2015/325093 pmid:26451148 pmcid:PMC4586956 fatcat:vxydnymcafhfznmmmqyzee2nxi


Massoomeh Hedayati Marzbali, Aldrin Abdullah, Mohammad Javad Maghsoodi Tilaki
Massoomeh Hedayati Marzbali, Aldrin Abdullah & Mohammad Javad Maghsoodi Tilaki Surveillability and Guardianship Attitudes: The Role of Multiple Mediators ACKNOWLEDGEMENTS The authors would like to thank  ...  Hedayati-Marzbali et al. (2016) suggested that natural surveillance is a second-order latent construct which consists of visibility and lighting as first-order constructs.  ...  Social cohesion items were adapted from the work of Hedayati et al. (2015), Reynald (2011), and Sampson et al. (1997) on a seven-pint Likert scale (1=strongly disagree, 7=strongly agree).  ... 
doi:10.21837/pm.v18i13.777 fatcat:gml67vej3vfqxlkwkn2x4np5g4

Androgens Involvement in the Pathogenesis of Renal Stones Formation

Mohammad Reza Naghii, Mnasour Babaei, Mehdi Hedayati, Bin He
2014 PLoS ONE  
Objective: The potential role for the gonadal steroids in the pathogenesis of urolithiasis, higher mean of plasma oxalate concentration and kidney calcium oxalate deposition influenced by androgens in men has been proposed. In this study, the serum levels of steroid hormones as a pathogenesis of this condition in male patients with active renal stone disease compared with controls was investigated. Methods: Forty patients diagnosed with renal stones and hospitalized for further clinical
more » ... ts or referred to our office after ultrasonographic evaluations participated in the study. Forty six healthy subjects served as controls. Steroid sex hormones in the plasma samples including testosterone, free testosterone, dihydrotestosterone, estradiol, and sex hormone binding globulin were analyzed. Results: A significant difference was observed between patients and the control subjects regarding serum testosterone, free testosterone, dihydrotestosterone, estradiol, and sex hormone binding globulin. Conclusions: Based on the results, a higher androgens level was diagnosed in renal stone patients, indicating a possibility of a substantial pathogenic role of testosterone, free testosterone, and dihydrotestosterone involvement in the pathogenesis of renal stones formation. Therefore, data presentation and further investigation on the relation between male steroids and urolithiasis is of importance and should be considered in evaluation of the etiology of the disease.
doi:10.1371/journal.pone.0093790 pmid:24695421 pmcid:PMC3973622 fatcat:xlyxbtk7vnevfcxfsffr74aitq

Increased Expression of miR-377-3p in Patients with Relapsing Remitting Multiple Sclerosis

Majid Amini Khorasgani, Parisa Mohammady Nejad, Mohammad Mehdi Moghani Bashi, Mohammad Hedayati
2019 SciMedicine Journal  
One of the most recent studies in the field of genetics is to investigate the role of microRNAs as biomarkers for the diagnosis of multiple sclerosis. It is an inflammatory and degenerative disease of the central nervous myelin, which is manifested in numerous small and large plaques in the white matter of the brain and spinal cord. Formerly called has-miR-377-3p, miR-377-3p is located within the chromosomal region 32q14, and is located in the SOD gene. SOD (Superoxide Dismutase) is a gene
more » ... ed on chromosomal region 22q21 and the protein encoded by this gene is the superoxide dismutase enzyme. The aim of this study was to evaluate the expression of miR-377 in people with RRMS (Relapsing-Remitting Multiple Sclerosis) and healthy individuals in the Isfahan population. The study included 49 patients with RRMS and 52 healthy individuals who had no history of autoimmune and inflammatory disease. Total RNA was extracted from the blood lymphocytes of the study subjects using Ficol and Trizol and then made using miRNA cDNA, cDNA specific kit, and expression was measured by real-time RT PCR in healthy subjects and patients. Was. According to the results, miR-377-3p expression was higher in patients than in healthy subjects (P = 0.036) and the sensitivity and diagnostic value of miRNA was AUC = 0.80 (Area under the Curve). ) is. The results were consistent with previous studies and miR-377-3p could be used as a biomarker for the diagnosis of Multiple Sclerosis.
doi:10.28991/scimedj-2019-0102-2 fatcat:nfhzci4x6jag3i5l7heiduzxmu
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