32 research outputs found

    Izučavanje CFD-om utjecaja brzine mlaza na miješanje i nastajanje mulja u velikim spremnicima sirove nafte

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    In this paper, computational fluid dynamic modelling was developed to study the effect of the floating jet velocity or submerged rotary jet in sludge prevention in a large crude-oil storage tank. The Euler-Euler method was used in a two-dimensional CFD model to describe oil and sludge flow behaviour at the bottom of the storage tank. By modifying some parameters, the k-e model was used to describe the turbulence of the mixing flow. The results show the effect of jet velocity, angle, and time on the mixing process. By increasing the velocity from 5 m s–1, the mixing pattern significantly changes and improves the mixing of the sludge with crude oil. To evaluate the results, chosen was the sludge profile related to the bottom of the sample tank, and modelling results showed an 80 cm reduction in thickness of the sludge, which corresponds well to the profile of the bottom of the tank. In addition, the y+ axis indicated that the amounts at all points were less than 300, which is acceptable in two-phase modelling. This work is licensed under a Creative Commons Attribution 4.0 International License.Računalnom dinamikom fluida modeliran je utjecaj brzine mlaza potopljene rotacijske mlazne miješalice na nastajanje mulja u velikim spremnicima nafte. U dvodimezionalnom CFD modelu primijenjena je Euler-Eulerova metoda za opisivanje toka nafte i mulja na dnu spremnika. Uz promjenu nekih parametara modelom k-e opisana je turbulencija toka miješanja. Rezultati pokazuju da na miješanje utječu brzina mlaza, kut i vrijeme miješanja. Povećanjem brzine od 5 m s–1 način miješanja znatno se mijenja i poboljšano je miješanje mulja sa sirovom naftom. Rezultati su procijenjeni proučavanjem odabranog profila mulja na dnu spremnika uzorka, a modeliranje pokazuje smanjenje debljine sloja mulja za 80 cm, što se slaže s profilom dna spremnika. Os y+ u svim točkama pokazuje iznose manje od 300, što je prihvatljivo u dvofaznom modeliranju. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna

    INVESTIGATING ALUMINIUM SHEET WRINKLING DURING THE DEEP DRAWING PROCESS

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    The purpose of this study is to consider the effect of different parameters on the wrinkling phenomenon of square cups during the deep drawing process. An experimental system was prepared which consisted of a hydraulic press capable of applying different loads on the sheet metal blank and a blank holder and the process was controlled by a computer. All simulations were performed by using the ABAQUS/EXPLICIT V6.9 software, and the effect of different aluminium alloys, punch and die radius, blank holder force, blank holder gap, and friction coefficient on the wrinkling phenomenon has been investigated. Moreover, the minimal blank holder force was obtained by plotting minor strain with respect to the major strain of produced cups, and obtaining the maximum height of wrinkle in a cup. The wrinkling phenomenon was further investigated on different alloys such as A6111-T4, AA5754-O and Al-1050. The results imply that increasing the blank holder force and friction coefficient on the one hand and reducing the blank holder gap, punch radius, and die radius on the other hand, may lead to a reduction in wrinkling during the deep drawing process. Nevertheless, under the same circumstances of the deep drawing process, the wrinkling of the A6111-T4 alloy is more significant compared to the Al-1050 and AA5754-O alloys, while the Al-1050 alloy needs less blank holder force to avoid wrinkling. Using this simulation program it is possible to easily simulate the wrinkling of sheet metal blanks with the least number of trial and error

    Baseline executive functions and receiving cognitive rehabilitation can predict treatment response in people with opioid use disorder

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    TR and AF have received supports from the Cognitive Science and Technologies Council (CSTC) of Iran and Tehran University of Medical Sciences (TUMS) for the ongoing Clinical Trial with NECOREDA.Background Impaired cognitive functions, particularly executive function, predicts poor treatment success in people with substance use disorders. The current study investigated the effect of receiving adjunct cognitive rehabilitation and baseline executive function (EF) measures on treatment response among people with opioid use disorder (OUD). Method The analysis sample consisted of 113 participants with OUD who were discharged from a compulsory court-mandated methadone maintenance treatment (MMT) and followed for 3 months. We used the Backward digit span/Auditory verbal learning, Stroop, and Trail making tests to assess the three measures of EF, including working memory, inhibition, and shifting, respectively. Treatment response was operationalized as (1) treatment retention and (2) the number of positive urine tests for morphine during 3-month follow-up periods. The study used Cox's proportional hazards model and linear mixed model to identify predictive factors. Results Lower Stroop interference scores predicted increased length of stay in treatment (χ2 = 33.15, P < 0.001). The linear mixed model showed that scores on auditory verbal learning test and group intervention predicted the number of positive urine tests during a 3-month follow-up. Conclusion Working memory and inhibitory control, as well as receiving cognitive rehabilitation, could be potentially considered as predictors of treatment response for newly MMT admitted patients with OUD. Assessment of EF before treatment initiation may inform treatment providers about patient's cognitive deficits that may interfere with therapeutic interventions.PostprintPeer reviewe

    HIV Programs in Iran (Persia), Iraq and Saudi Arabia: A Brief Review of Current Evidence in West and Southwest Asia

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    Background: In Western and Southwest Asia, literature is not documented on human immunodeficiency virus (HIV) programs in Iran, Iraq and Saudi Arabia. The present study is the first brief review that describes HIV programs in these three neighboring countries.Methods: Data regarding the evidence of HIV programs were gathered through a systematic literature searching. English publications were retrieved through searching online scientific databases. Grey literature was also searched online. The review was based on the studies related to the last decade.Findings: Systematic searching resulted in retrieving 21,948 studies but only 21 studies were relevant to the study aim. The review findings indicated that Iran has provided a nationwide sero-surveillance data system and has identified its key populations. Detecting HIV prevalence has been limited to case-finding in Iraq and Saudi Arabia. However, strategic plans for HIV have been provided in the three countries. HIV education, knowledge and support have been provided but still needs consideration in the three countries especially in Iraq. The low coverage of antiretroviral therapy (ART) has remained a critical gap in the provision of comprehensive HIV programs in these three countries. This issue has been followed by the lack of opiate substitution therapies for drug dependents and injecting drug users in Iraq and Saudi Arabia. Condom promotion and voluntary HIV counselling and testing have been provided for at-risk groups in the three countries but need more nationwide coverages. However, needle and syringe programs (NSPs) have been only provided in Iran.Conclusion: The review concluded that the provision of effective HIV programs should address training human resources and infrastructural development. This issue should be facilitated by international collaborations and governmental supports

    Aag-initiated base excision repair promotes ischemia reperfusion injury in liver, brain, and kidney

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    Inflammation is accompanied by the release of highly reactive oxygen and nitrogen species (RONS) that damage DNA, among other cellular molecules. Base excision repair (BER) is initiated by DNA glycosylases and is crucial in repairing RONS-induced DNA damage; the alkyladenine DNA glycosylase (Aag/Mpg) excises several DNA base lesions induced by the inflammation-associated RONS release that accompanies ischemia reperfusion (I/R). Using mouse I/R models we demonstrate that Aag[superscript −/−] mice are significantly protected against, rather than sensitized to, I/R injury, and that such protection is observed across three different organs. Following I/R in liver, kidney, and brain, Aag[superscript −/−] mice display decreased hepatocyte death, cerebral infarction, and renal injury relative to wild-type. We infer that in wild-type mice, Aag excises damaged DNA bases to generate potentially toxic abasic sites that in turn generate highly toxic DNA strand breaks that trigger poly(ADP-ribose) polymerase (Parp) hyperactivation, cellular bioenergetics failure, and necrosis; indeed, steady-state levels of abasic sites and nuclear PAR polymers were significantly more elevated in wild-type vs. Aag[superscript −/−] liver after I/R. This increase in PAR polymers was accompanied by depletion of intracellular NAD and ATP levels plus the translocation and extracellular release of the high-mobility group box 1 (Hmgb1) nuclear protein, activating the sterile inflammatory response. We thus demonstrate the detrimental effects of Aag-initiated BER during I/R and sterile inflammation, and present a novel target for controlling I/R-induced injury.National Institutes of Health (U.S.) (Grant R01-CA055042)National Institutes of Health (U.S.) (Grant R01-CA149261)National Institutes of Health (U.S.) (Grant P30-ES02109)Ellison Medical Foundatio

    Social Work Guidelines for Street Children with Substance Use Disorders

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    This study was designed with the purpose of providing organized instructions on how to improve the psychological, medical, and social circumstances of street children with concurrent substance use disorders. Due to the special vulnerabilities of these children, customized guidelines are required in order to maximize the treatment outcomes. Systemic review of literature was applied on a large number of national and international journal articles available on the phenomenon of substance use among street children. The literature review was followed by a qualitative study using in-depth interviews in order to record and analyze the experience of experts working in this field. The preliminary draft was reviewed by the experts and final modifications were applied. The ultimate guideline presents practical recommendations for different stages of providing service for the target population including case finding, motivational interventions, assessment, care and intervention planning, and follow-ups. Street children face various physical, psychological, and social complications. Substance use disorders can exacerbate their circumstances and add to the complexity of their problems. The current guideline is an initial step to better understanding and treating street children who use drugs. Further research is required to investigate the effectiveness and long term results of this guideline .considering the fact that Iran is one of the many countries dealing with this phenomenon, adjustments should be made for application in different cultures

    Expression of Pro-Apoptotic Bax and Anti-Apoptotic Bcl-2 Proteins in Hydatidiform Moles and Placentas With Hydropic Changes

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    Morphologic examination still forms the main diagnostic tool in the differential diagnosis of molar placentas. However the criteria are subjective and show considerable inter-observer variability among pathologists. The aim of the present study was to investigate the role of Bcl-2 and Bax immunostaining in the differential diagnosis of molar placentas. Bax and Bcl-2 immunohistochemical staining were performed in 19 molars (8 partial and 11 complete hydatidiform mole) and 10 non-molar (hydropic abortion) formalin-fixed, paraffin-embedded tissue samples. Ploidy analysis using flow cytometry had confirmed diploidy in hydropic abortions and complete hydatidiform moles and triploidy in partial hydatidiform moles. Bcl-2 expression was observed only in syncytiotrophoblasts, No immunoreactivity was detected in Cytotrophoblasts, and stromal cells, the total score averages of Bcl-2 immunoexpression in partial hydatidiform moles and hydropic abortions were significantly higher than in complete hydatidiform moles, whereas no significant difference was observed between partial hydatidiform moles and hydropic abortions. Bax immunoreactivity was observed in cytotrophoblasts, stromal cells and occasionally in syncytiotrophoblasts. No statistically significant difference in Bax immunoexpression total score was observed among various groups. Based on the results of this study, Bcl-2 immunostaining offers a potential adjunctive diagnostic tool to distinguish complete hydatidiform mole from partial hydatidiform mole and hydropic abortion, but not partial hydatidiform mole from hydropic abortion, Bax immunostaining cannot be helpful in this regard

    Iranian Female Methadone Patients and the Perceived Educational Needs Related to Human Immunodeficiency Virus

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    Background: Iranian female methadone patients are at risk of human immunodeficiency virus (HIV) due to involvement in high-risk sexual behaviours and/or needle sharing. The present study aimed to explore the perceived educational needs related to HIV among a group of Iranian female methadone patients. Methods:The research design was qualitative and the participants were sampled purposively. Semi-structured interviews were conducted with 34 women and 19 clinicians in Sari, Mashhad, and Tehran, Iran. Then, qualitative content analysis was implemented. Findings: The emergence of three major themes and six minor themes was revealed. Women expressed a need to increase their knowledge including women-specific pathophysiology and disease progression and the modes of the virus transmission and prevention. Women also expressed a need to enhance their knowledge and skills related to the physical management of the virus including self-care and reproductive health. Other themes included perceived psychosocial needs including removing stigma and access to resources in the community. Conclusion: Women reported a wide range of educational needs from basic knowledge to advanced skills. The findings can be used in designing women-specific educational programs related to HIV in Iran. Larger studies are suggested with gender-mixed samples in the Persian contex

    The Post-Eocene Evolution of the Doruneh Fault Region (Central Iran): The Intraplate Response to the Reorganization of the Arabia-Eurasia Collision Zone

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    The Cenozoic deformation history of Central Iran has been dominantly accommodated by the activation of major intracontinental strike-slip fault zones, developed in the hinterland domain of the Arabia-Eurasia convergent margin. Few quantitative temporal and kinematic constraints are available from these strike-slip deformation zones, hampering a full assessment of the style and timing of intraplate deformation in Iran and the understanding of the possible linkage to the tectonic reorganization of the Zagros collisional zone. This study focuses on the region to the north of the active trace of the sinistral Doruneh Fault. By combing structural and low-temperature apatite fission track (AFT) and (U-Th)/He (AHe) thermochronology investigations, we provide new kinematic and temporal constraints to the deformation history of Central Iran. Our results document a post-Eocene polyphase tectonic evolution dominated by dextral strike-slip tectonics, whose activity is constrained since the early Miocene in response to an early, NW-SE oriented paleo-σ1 direction. A major phase of enhanced cooling/exhumation is constrained at the Miocene/Pliocene boundary, caused by a switch of the maximum paleo-σ1 direction to N-S. When integrated into the regional scenario, these data are framed into a new tectonic reconstruction for the Miocene-Quaternary time lapse, where strike-slip deformation in the intracontinental domain of Central Iran is interpreted as guided by the reorganization of the Zagros collisional zone in the transition from an immature to a mature stage of continental collision

    Harnessing the Power of Smart and Connected Health to Tackle COVID-19:IoT, AI, Robotics, and Blockchain for a Better World

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    As COVID-19 hounds the world, the common cause of finding a swift solution to manage the pandemic has brought together researchers, institutions, governments, and society at large. The Internet of Things (IoT), Artificial Intelligence (AI) &#x2014; including Machine Learning (ML) and Big Data analytics &#x2014; as well as Robotics and Blockchain, are the four decisive areas of technological innovation that have been ingenuity harnessed to fight this pandemic and future ones. While these highly interrelated smart and connected health technologies cannot resolve the pandemic overnight and may not be the only answer to the crisis, they can provide greater insight into the disease and support frontline efforts to prevent and control the pandemic. This paper provides a blend of discussions on the contribution of these digital technologies, propose several complementary and multidisciplinary techniques to combat COVID-19, offer opportunities for more holistic studies, and accelerate knowledge acquisition and scientific discoveries in pandemic research. First, four areas where IoT can contribute are discussed, namely, i) tracking and tracing, ii) Remote Patient Monitoring (RPM) by Wearable IoT (WIoT), iii) Personal Digital Twins (PDT), and iv) real-life use case: ICT/IoT solution in Korea. Second, the role and novel applications of AI are explained, namely: i) diagnosis and prognosis, ii) risk prediction, iii) vaccine and drug development, iv) research dataset, v) early warnings and alerts, vi) social control and fake news detection, and vii) communication and chatbot. Third, the main uses of robotics and drone technology are analyzed, including i) crowd surveillance, ii) public announcements, iii) screening and diagnosis, and iv) essential supply delivery. Finally, we discuss how Distributed Ledger Technologies (DLTs), of which blockchain is a common example, can be combined with other technologies for tackling COVID-19
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