29 research outputs found

    Estimating the maximum earthquake magnitude in the Iranian Plateau

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    The Iranian Plateau has been subjected to destructive earthquakes throughout its history. Reliable assessment of the seismic hazard in this earthquake-prone region is therefore essential. Our study focuses on estimating the maximum earthquake magnitude as one of the main parameters of seismic hazard analysis. We implemented two quantitative approaches, namely, probabilistic and deterministic. The probabilistic method allows combining the historical (i.e. incomplete) and the instrumental parts of a catalogue with different levels of completeness and considers the uncertainties in earthquake magnitude determination. In this study, we used a unified, declustered, and complete catalogue of earthquakes in Iran, covering the period from the fourth century BC to 2019. We calculated the maximum possible magnitudes for hundreds of grid points by using the seismicity data in a 200-km radial region around each grid point. The maximum possible earthquake was observed to vary between 6.0 and 8.2, and the highest values were found in the Alborz-Azarbayejan seismotectonic province, Kopeh-Dagh, central east Iran, Makran, and the southeast Zagros. The lowest mmax values were found in the Persian Gulf, Arabian Platform, Esfahan-Sirjan region, and the Dasht-e-Kavir Desert in central Iran. As a second part to this study, we calculated the maximum credible earthquakes for 1103 identified major faults by using five empirical magnitude-scaling relationships. Our results were consistent with both the observed earthquakes and the seismic potential of the various seismogenic zones of Iran. The study results can be used in future seismic hazard analyses and have fundamental implications for mitigating seismic risk in Iran.http://link.springer.com/journal/10950hj2022Geolog

    Twisted energy ladder : complexities and unintended consequences in the transition to modern energy services

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    More than one-third of the world’s population has inadequate access to modern energy services and suffers as a consequence. A better understanding of energy transition is vital for improving future programs. This thesis investigates the challenges of transitioning to modern energy services with the goal of informing policy-making. Chapter 2 is a review of the literature on energy analysis and energy system uptake by the households with a particular focus on rural regions. Building upon the findings in the literature, a new conceptual framework is developed that can act as a basis for developing new empirical and theoretical models of household energy system uptake and use. In Chapter 3, the private sector based approach to rural energy provision (i.e. electrification and Improved Cookstove (ICS) dissemination) is investigated by examining two enterprises in India. Results indicate that the private sector based approach to rural energy provision cannot be a universal solution. It further shows that enterprises are facing many challenges that are beyond their capacity to address, necessitating alternate approaches to private sector involvement. Chapter 4 and 5 investigate the uptake of ICS by commercial kitchens in Bangalore and its potential health implications. The attributes of ICS and Liquefied Petroleum Gas (LPG) stove, as perceived by stove users and owners, are explored and the reasons for purchasing ICS are assessed. Results indicate that both groups mostly prefer LPG stoves and that ICS uptake is mainly motivated by economic factors. The potential health implications of this switch in the commercial kitchens are explored by investigating the stove’s emission characteristics (based on both secondary data and direct emission measurements), the stoves smokiness (as perceived by users and owners); and some health symptoms associated with stove smoke. Uptake of ICS by these commercial kitchens is found to potentially have adverse health implications. In brief, this thesis concludes that rural energy provision policies can be improved through a greater emphasis on the human dimension, comprehensive assessment of the target population, and ongoing evaluation of the programs’ outcomes given the major challenges in improving rural energy access and possibilities for spillovers into other market segments.Science, Faculty ofResources, Environment and Sustainability (IRES), Institute forGraduat

    Effects of fuel ethanol content and injector temperature on the spray characteristics of gasoline direct-injection atomizers

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    Recently, the Energy Policy Act of 2005 was passed into U.S. Law. This comprehensive energy legislation includes, for the first time in U.S. history, a national renewable fuels standard (RFS). The RFS legislates, with immediate effect, a significant increase in renewable fuel usage over a six-year period starting at 4 billion gallons in 2006 and increasing to 7.5 billion gallons in 2012. In practice, these legal requirements are most likely to be met by the increased use Biodiesel fuels and, most significantly, of ethanol as an additive to conventional gasoline. It is well known that the addition of ethanol (C₂H₅OH) to gasoline, which is itself a multi-component hydrocarbon blend, can significantly change the distillation characteristics of the fuel. In a fully warm, port-fuel-injected (PFI) engine, the change in fuel properties may not be significant. However, it is to be expected that the next generation of gasoline engines will use direct-injection fuelling strategies. The potential advantages of direct-injection spark-ignition (DISI) engine systems are substantial. However, the limited time available for fuel preparation in DlSl systems suggests that the technology may be more sensitive to fuel properties than previous generation injection technologies. This study investigates the changes in DISI fuel spray structure induced by the addition of ethanol, in varying amounts, to a base fuel of fixed composition, a process typically known as ’splash blending’. Five fuels of different ethanol content were injected into atmosphere at an injection pressure of 10.0 MPa through two prototype DISI fuel injectors (one single hole and one multi-hole design). The fuels were: a 5-component model fuel, comprised of isopentane, iso-octane, n-octane, n-decane and dodecane, simulated E5 (5% ethanol 95% model fuel), simulated E10 (10% ethanol 90% model fuel), simulated E22 (22% ethanol, 78% model fuel), E80 (80% ethanol, 20% model fuel) and finally pure ethanol. The effect of each fuel on the global characteristics of the spray was examined at four different temperatures (20, 40, 60 and 80 degrees Celsius) using Mie-Scattering, Schlieren and Shadowgraphy imaging techniques. Different stages of the spray development were identified. In accordance with the literature, increasing the fuel temperature was seen to increase the spray penetration while narrowing the spray structure for all fuels. At low fuel temperatures, the impact of fuel composition was negligible. The results showed the effect of fuel composition on the spray structure to be most evident in intermediate temperatures. Further increasing the fuel temperature caused spray collapse for all fuel compositions. Evidence of flash boiling was observed at high fuel temperatures. The ethanol content of fuel blends was not found to be proportional to the changes in spray structure. Finally, observations showed the sprays exhibited the highest level of shot-to-shot variability in the case of intermediate fuel temperatures. Sprays from the swirl-type injector were found to be more consistent than those of multi-hole injectors.Applied Science, Faculty ofMechanical Engineering, Department ofGraduat

    Criblage Combinatoire de Médicament en Microfluidique de Gouttes

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    Les puces microfluidiques sont de petites plateformes permettant de manipuler des fluides dans des canaux dont les dimensions sont à l'échelle submillimétrique. Ces dispositifs ont facilité la découverte de médicaments en augmentant le débit, le contrôle spatial de la diffusion des facteurs de signal, l'automatisation et la réduction du coût des expériences. La combinaison de médicaments est une stratégie alternative et prometteuse pour accélérer la découverte de médicaments, soit en combinant deux médicaments déjà approuvés, soit en combinant un candidat médicament avec un médicament approuvé. Le concept de combinaison d'antibiotiques s'aligne sur les preuves croissantes que les antibiotiques efficaces semblent interagir avec plus d'une cible. En général, la synergie n'est pas évidente à prévoir car elle résulte d'interactions complexes dans les voies cellulaires. L'exploration systématique de l'espace combinatoire pourrait être prolifique car des combinaisons synergiques non évidentes pourraient être identifiées.Dans cette thèse, nous avons proposé une nouvelle méthode basée sur des systèmes microfluidiques en réseau et des chambres d'hydrogel pour augmenter le débit des essais basés sur la diffusion tout en évitant un flux de travail complexe. Dans cette approche, les cellules restent dans la même position, et les réactifs sont amenés jusqu'à elles. Ainsi, chaque point reçoit un traitement connu, ce qui élimine la nécessité d'un marquage fluorescent ou d'un code-barres ADN. Deux gradients de concentration de petites molécules se chevauchant se forment dans chaque chambre cellulaire. Ainsi, contrairement aux plaques de microtitration où chaque puits contient une seule dose ou une seule combinaison de doses, notre puce microfluidique génère des combinaisons de doses multiples par chambre sans augmenter le travail de mélange des médicaments à diverses concentrations.J'ai commencé par décrire la conception de notre dispositif microfluidique qui distribue les composés médicamenteux dans les chambres, les dilue dans un hydrogel chargé de cellules et les mélange avec un autre composé. Pour fabriquer un tel dispositif, la principale difficulté est de fabriquer des membranes PDMS avec des trous traversants pour connecter une couche du dispositif microfluidique à la couche suivante. J'ai mis au point deux méthodes pour fabriquer des membranes en PDMS avec des micro-caractéristiques et des trous traversants accessibles.Pour montrer les performances de notre appareil, j'ai d'abord testé deux paires d'antibiotiques qui interagissent fortement : la combinaison sulfamonométhoxine × triméthoprime qui produit une interaction synergique et la combinaison FOS × nitrofurantoïne qui produit une interaction antagoniste. Nous avons calculé la surface des zones d'inhibition pour mesurer l'efficacité du traitement antibiotique. Nous avons ensuite testé la répétabilité des résultats en traitant toutes les chambres cellulaires avec la même paire d'antibiotiques à des concentrations identiques. Le coefficient de variabilité de l'aire des zones d'inhibition dans l'expérience de répétabilité était de 5,7 % pour le traitement avec une solution de 6,4 µg/ml de fosfomycine et de 7,6 % pour le traitement avec une solution de 20,48 µg/ml de nitrofurantoïne.En fin, j'ai expliqué l'itération à haut débit pour l'analyse de combinaisons de 12 antibiotiques. Nous avons démontré les interactions synergiques entre sulfamonométhoxine et triméthoprime et les interactions additives entre nitrofurantoïne et ampicilline. De plus, nous avons analysé statistiquement la répétabilité des traitements par médicament unique en calculant le coefficient de variation pour la taille des zones d'inhibition dans les hydrogels. Dans presque tous les cas, le coefficient de variation était inférieur à 10%, ce qui indique une bonne uniformité des résultats.J'ai consacré le dernier chapitre à discuter de cinq directions que nous pouvons poursuivre dans la suite de cette thèse.Microfluidic chips are small platforms to manipulate fluids in channels with dimensions at the submillimeter scale. These devices have facilitated drug discovery by increasing the throughput, spatial control on the diffusion of signal factors, automation, and reducing the cost of experiments. Drug combination therapy (DCT) is an alternative and promising strategy to accelerate drug discovery, either by combining two already approved drugs (repurposing by DCT) or by combining a drug candidate with an approved drug (boosting by DCT). The concept of antibiotic combination aligns with the increasing evidence that successful antibiotics seem to interact with more than one target. Considering the synergistic combination of β-lactam antibiotics and β-lactamase inhibitors as an exceptional case, the discovery of other combinations results from clinical experimentations. In general, synergy is non-obvious to predict as it arises from complex interactions in cellular pathways. The modern model of combinatorial discovery aims to systematically search for synergistic combinations instead of relying on the serendipitous discovery of synergy. Systematic exploration of combinatorial space could be prolific as non-obvious synergistic combinations might be identified.In this thesis, we proposed a novel method based on arrayed microfluidic systems and hydrogel chambers to increase the throughput of the diffusion-based assays while avoiding complex workflow. In this approach, the cells stay in the same position, and reagents are brought to them. Thus, each spot receives a known treatment, eliminating the need for fluorescent labeling or DNA barcoding. Two overlapping concentration gradients of small molecules will form in each cell chamber. Thus, in contrast to microtitration plates where each well contains a single dose or a single combination of doses, our microfluidic chip generates multiple-dose combinations per chamber without increasing the labor of mixing drugs at various concentrations.I began by describing the design of our microfluidic device which distributes the drug compounds to the chambers, dilutes them in a cell-laden hydrogel, and mixes them with another compound. To fabricate such a device, the main difficulty is fabricating PDMS membranes with through-layer holes to connect one layer of the microfluidic device to the next layer. I developed two methods for fabricating PDMS membranes with microfeatures and accessible through-layer holes.To show the performance of our device, first I tested two pairs of antibiotics that strongly interact: Sulfamonomethoxine × Trimethoprim combination that produces a synergistic interaction and Fosfomycin × Nitrofurantoin combination that produce an antagonistic interaction. We further tested the repeatability of the results by treating all the cell chambers with the same pair of antibiotics at identical concentrations. The coefficient of variability of the area of inhibition zones in the repeatability experiment was 5.7% for treatment with a 6.4 µg/ml solution of Fosfomycin and 7.6% for treatment with a 20.48 µg/ml solution of Nitrofurantoin, showing excellent reproducibility.Lastly, I explained the high-throughput iteration of the microdevice for analysis of combinations of 12 antibiotics. We demonstrated the synergistic interactions between Sulfamonomethoxine and Trimethoprim and additive interactions between Nitrofurantoin and Ampicillin. Further, we statistically analyzed the repeatability of single-drug treatments by calculating the coefficient of variation for the size of inhibition zones in the hydrogels. In almost all cases the CV was less than 10%, which indicates a good uniformity in the results.I dedicated the final chapter to discussing five directions we can pursue in the continuation of this thesis

    Study on Association Between GSTP1 (rs1695) and Late-Onset Alzheimer Disease and Interaction With APOe4

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    Objectives GSTs are detoxification enzymes that remove excess reactive oxygen species (ROS) from cells. Evidence suggests that oxidative stress plays a role in several stages of the neurodegenarative disease like Alzheimer disease. Free radicals and similar molecules are classified as reactive oxygen species (ROS), which can cause oxidative modifications in the cell. In this study we have investigated the association between GSTP1 (rs1695) and AD risk for  genetic variant in Iranian population. Methods & Materials The patient group consisted of 280 cases for GSTP1 gene investigation, whose Alzheimer disease had been approved by psychologists based on clinical test (DSM-IV). The control group included 168 healthy individuals, satisfying the condition of not having any psychological disorders. Individuals’ genotype have been determined by PCR-RFLP method. Statistical analysis was done by logistic regression using OpenEpi 2.3.1 and SPSS 16. Results Significant association was observed between heterozygote genotype (AG) rs1695 A/G of GSTP1 gene and the risk of Alzheimer disease (P=0.005, OR=0.57[0.38-0.84]).This genotype acts as a protective factor. This observed result was significant in within women group (P=0.02). Significant interaction was also found between heterozygote genotype (AG) rs1695 A/G of GSTP1 gene (protective factor) and absent ε4 allele in our study group (P=0.001). Conclusion Based on our results, we suggest that heterozygote genotype (AG) rs1695 A/G of GSTP1 gene can act as a protective factor for Alzheimer disease in Iranian population.&nbsp

    مقایسه تست عملکردی FMS در ورزشکاران ووشوکار حرفه‎ای با و بدون آسیب

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    Background and Aim: Many researchers have reported changes in movement patterns after injury. In this regard, the aim of this study was to compare the performance test of FMS in professional Wushu athletes with and without injury. Methods: In this cross-sectional and causal-comparative study, 120 Wushu players in the age range of 23 to 30 years were purposefully selected based on inclusion criteria. The evaluation of functional movement patterns was assessed by FMS functional test. Data were analyzed using SPSS software version 26 through descriptive statistics, the Chi-square test was used to compare the difference between the groups with and without injury, and univariate and multivariate logistic regression tests were used to compare the two groups. Results: The results of this study showed that there was a significant difference between the performance test scores between the two groups. The non-injured group reported a higher overall score than those with a history of injury. Conclusion: It can be pointed out that injury can mainly lead to changes in movement patterns. Athletes with a history of previous injury may have faulty movement patterns; therefore, they may have problems when performing high-level sports activities. Please cite this article as: Karimizadeh Ardakani M, Kowsari R, Varmazyar M, Najafi A, Mousavi SH. Comparison of FMS Performance Test in Professional Wushu Athletes with and without Injury. Irtiqa Imini Pishgiri Masdumiyat. 2022;10(3):280-9.                           سابقه و هدف: محققان بسیاری تغییر در الگوهای حرکتی پس از بروز آسیب را گزارش کرده‎اند. در همین راستا هدف از مطالعه حاضر مقایسه تست عملکردی FMS در ورزشکاران ووشوکار حرفه‎ای با و بدون آسیب می‎باشد. روش کار: این مطالعه از نوع مقطعی و علی­مقایسه‌ای، کاربردی بود. در این تحقیق تعداد 120 ووشوکار با دامنه سنی23 تا 30  سال به صورت هدفمند بر اساس معیار­های ورود و خروج قرار گرفتند. ارزیابی الگوهای حرکتی عملکردی به وسیله آزمون عملکردی FMS ارزیابی شد. داده­ها به وسیله نرم افزار SPSS نسخه 26 و از طریق آمار توصیفی، آزمون خی­دو براي مقايسه تفاوت بين گروه با و بدون آسیب و آزمون رگرسیون لجستیک تک متغیره و چند متغیره به منظور مقایسه بین دو گروه­ها استفاده شد. لازم به ذکر است در اجرای پژوهش ملاحظات اخلاقی مطابق با دستورالعمل کمیته اخلاق دانشگاه تهران در نظر گرفته شده است. یافته‌ها: نتایج این پژوهش نشان داد تفاوت معنی داری بین نمرات آزمون عملکردی بین دو گروه وجود داشت. بدین صورت که گروهی که هیچ‎گونه آسیبی را نداشتند نمره کلی بیشتری نسبت به افراد با سابقه آسیب دیدگی گزارش کردند. نتیجه‌گیری: در یک نتیجه‌گیری کلی می‌توان به این نکته اشاره کرد که آسیب عمدتا می‎تواند منجر به تغییر در الگوهای حرکتی شود و از آنجایی که الگوی حرکتی کارآمد لازمه فعالیت‎های ورزشی سطح بالا است، ورزشکاران با سابقه آسیب قبلی دچار اختلال در این فاکتور بسیار مهم هستند. به این مقاله، به صورت زیر استناد کنید: Karimizadeh Ardakani M, Kowsari R, Varmazyar M, Najafi A, Mousavi SH. Comparison of FMS Performance Test in Professional Wushu Athletes with and without Injury. Irtiqa Imini Pishgiri Masdumiyat. 2022;10(3):280-9.                          &nbsp

    Natural Selection at the NHLH2 Core Promoter Exceptionally Long CA-Repeat in Human and Disease-Only Genotypes in Late-Onset Neurocognitive Disorder

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    Background: Approximately 2% of the human core promoter short tandem repeats (STRs) reach lengths of ≥6 repeats, which may in part be a result of adaptive evolutionary processes and natural selection. A single-exon transcript of the human nescient helix loop helix 2 (NHLH2) gene is flanked by the longest CA-repeat detected in a human protein-coding gene core promoter (Ensembl transcript ID: ENST00000369506.1). NHLH2 is involved in several biological and pathological pathways, such as motivated exercise, obesity, and diabetes. Methods: The allele and genotype distribution of the NHLH2 CA-repeat were investigated by sequencing in 655 Iranian subjects, consisting of late-onset neurocognitive disorder (NCD) as a clinical entity (n = 290) and matched controls (n = 365). The evolutionary trend of the CA-repeat was also studied across vertebrates. Results: The allele range was between 9 and 25 repeats in the NCD cases, and 12 and 24 repeats in the controls. At the frequency of 0.56, the 21-repeat allele was the predominant allele in the controls. While the 21-repeat was also the predominant allele in the NCD patients, we detected significant decline of the frequency (p < 0.0001) and homozygosity (p < 0.006) of this allele in this group. Furthermore, 12 genotypes were detected across 16 patients (5.5% of the entire NCD sample) and not in the controls (disease-only genotypes; p < 0.0003), consisting of at least one extreme allele. The extreme alleles were at 9, 12, 13, 18, and 19 repeats (extreme short end), and 23, 24, and 25 repeats (extreme long end), and their frequencies ranged between 0.001 and 0.04. The frequency of the 21-repeat allele significantly dropped to 0.09 in the disease-only genotype compartment (p < Downloaded by: Albert R.Mann Library 132.174.252.179 - 9/3/2020 9:30:52 AM 2 Gerontology Afshar et al. DOI: 10.1159/000509471 0.0001). Evolutionarily, while the maximum length of the NHLH2 CA-repeat was 11 repeats in non-primates, this CArepeat was ≥14 repeats in primates and reached maximum length in human. Conclusion: We propose a novel locus for late-onset NCD at the NHLH2 core promoter exceptionally long CA-STR and natural selection at this locus. Furthermore, there was indication of genotypes at this locus that unambiguously linked to late-onset NCD. This is the first instance of natural selection in favor of a predominantly abundant STR allele in human and its differential distribution in late-onset NCD

    EXPERIMENTAL STUDY ON TURBULENT HEAT TRANSFER, PRESSURE DROP, AND THERMAL PERFORMANCE OF ZnO/WATER NANOFLUID FLOW IN A CIRCULAR TUBE

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    In this experimental study heat transfer and pressure drop behavior of ZnO/water nanofluid flow inside a circular tube with constant wall temperature condition is in

    Strategies for directing cells into building functional hearts and parts

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    This review presents the current state-of-the-art, emerging directions and future trends to direct cells for building functional heart parts.</p
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