Multilevel assimilation of inverted seismic data

I ensemble-basert data-assimilering (DA) er størrelsen på ensemblet vanligvis begrenset til hundre medlemmer. Rett frem bruk av ensemble-basert DA kan resultere i betydelig Monte Carlo-feil, som ofte viser seg som alvorlig undervurdering av parameterusikkerheter. Assimilering av store mengder samtidige data forsterker de negative effektene av Monte Carlo-feilen. Avstandsbasert lokalisering er det konvensjonelle middelet for å begrense dette problemet. Denne metoden har imidlertid sine egne ulemper. Den vil, f.eks., fjerne sanne korrelasjoner over lange distanser og det er svært vanskelig å benytte på data som ikke har en unik fysisk plassering. Bruk av modeller med lavere kvalitet reduserer beregningskostnadene per ensemble-medlem og gir derfor muligheten til å redusere Monte Carlo-feilen ved å øke ensemble-størrelsen. Men, modeller med lavere kvalitet øker også modelleringsfeilen. Data-assimilering på flere nivåer (MLDA) bruker et utvalg av modeller som danner hierarkier av både beregningskostnad og beregningsnøyaktighet, og prøver åå oppnå en bedre balanse mellom Monte Carlo-feil og modelleringsfeil. I dette PhD-prosjektet ble flere MLDA-algoritmer utviklet og deres kvalitet for assimilering av inverterte seismiske data ble vurdert på forenklede reservoarproblemer. Bruk av modeller på flere nivå innebærer introduksjon av noen numeriske feil (multilevel modeling error, MLME), i tillegg til de allerede eksisterende numeriske feilene. Flere beregningsmessig rimelige metoder ble utviklet for delvis å kompansere for MLME i gjennomføring av data-assimilering på flere nivåer. Metodene ble også undersøkt under historie tilpassing på forenklede reservoar problemer. Til slutt ble en av de nye MLDA-algoritmene valgt og ytelsen ble vurdert på et historie tilpassings problem med en realistisk reservoar modell.In ensemble-based data assimilation (DA), the ensemble size is usually limited to around one hundred. Straightforward application of ensemble-based DA can therefore result in significant Monte Carlo errors, often manifesting themselves as severe underestimation of parameter uncertainties. Assimilation of large amounts of simultaneous data enhances the negative effects of Monte Carlo errors. Distance-based localization is the conventional remedy for this problem. However, it has its own drawbacks, e.g. not allowing for true long-range correlations and difficulty in assimilation of data which do not have a specific physical location. Use of lower-fidelity models reduces the computational cost per ensemble member and therefore renders the possibility to reduce Monte Carlo errors by increasing the ensemble size, but it also adds to the modeling error. Multilevel data assimilation (MLDA) uses a selection of models forming hierarchies of both computational cost and computational accuracy, and tries to obtain a better balance between Monte Carlo errors and modeling errors. In this PhD project, several MLDA algorithms were developed and their quality for assimilation of inverted seismic data was assessed in simplistic reservoir problems. Utilization of multilevel models entails introduction of some numerical errors (multilevel modeling error, MLME) to the problem in addition to the already existing numerical errors. Several computationally inexpensive methods were devised for partially accounting for MLME in the context of multilevel data assimilation. They were also investigated in simplistic reservoir history-matching problems. Finally, one of the novel MLDA algorithms was chosen and its performance was assessed in a realistic reservoir history-matching problem.Doktorgradsavhandlin

Graphite furnace atomic absorption spectrometric determination of cadmium after solid-liquid extraction with dithizone

A method for the determination of trace amount of cadmium ion after preconcentration by extracting its dithizone complex into molten naphthalene was developed. Several experimental conditions such as pH of the solution, stirring time, the amounts of naphthalene, standing time and volume of the solution were optimized. Trace amount of cadmium ion in aqueous solution of sample was chelated with 5 mL of 0.001 M dithizone at pH 8. After addition of 0.15 g naphthalene, the solution was heated to about 85 oC and stirred (800rpm) for 2 min to reproduce the microcrystalline naphthalene. Cadmium ion was determined by a graphite furnace atomic absorption spectrometer. The interfering effects of diverse concomitant ions (cations and anions) wereinvestigated. Artificial sea water and a standard reference material (SRM) were analyzed by this method. The sensitivity and detection limit of 1.2 ngL-1 and 1.5 ng L-1 were found, respectively

Association of adiponectin rs17300539 gene polymorphism with a non-alcoholic fatty liver disease in an Iranian population

Background: Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disorder, resulting from exceeding fat cumulating in the liver .Adiponectin, a protein secreted from the adipose tissue, reduces liver inflammation. In this study, the relationship between adiponectin rs17300539 gene polymorphism and a non-alcoholic fatty liver disease was investigated. Materials and Methods: This case-control study was conducted on 80 subjects with NAFLD and 80 healthy subjects. The determination of polymorphism rs17300539 of adiponectin gene was performed by the PCR-RFLP method and electrophoresis technique. The plasma levels of adiponectin and insulin hormones were measured by an enzyme-linked immunosorbent assay (ELISA) kit. Results: The results showed that there was no significant difference in allele frequencies between the two groups of the case and control (P>0.05). The body mass index (BMI) in genotype GA carriers was higher than that of genotype GG carriers (P<0.05). Moreover, the diastolic blood pressure in the male patients carrying the genotype GA was higher than that in the genotype GG carriers (P<0.05). In the female patients carrying the genotype GA, the AST and triglyceride levels were higher than the GG female carriers (P<0.05). Conclusion: It seems that the allele G can be beneficial in reducing the side-effects of the non-alcoholic fatty liver disease

Assessment of heavy metals (Pb, Cd and Cu) concentrations in groundwater resources of Shahrab and its surrounding villages in Ardestan city during May and June 2015

Background and Aims: The increasing demand for groundwater in Iran, which is facing water shortages and lack of rainfall, is intensively ongoing. Consumption of water contaminated with heavy metals may result in adverse health effects in people. The present study aimed to determine the amount of arsenic,cadmium and lead in groundwater resources of Shahrab and its surrounding areas having a lot of drinking and agricultural water uses.Materials and Methods: A total of fourteen wells supplying rural drinking water in Shahrab area were sampled. Sampling was performed by standard methods. EC, pH and Eh were measured using a portable pH meter. Heavy metals concentration were also determined by ICP-MS. All stages of this research were conducted ethically.Results: Cadmium concentrations were less than 3 μg/L in studied samples. However, lead concentrations were more than 10 μg/L, exceeding national drinking water standards in Iran. Furthermore, arsenic concentrations exceeded national standards (10 μg/L) in three sample.Conclusion: A significant positive correlation was not observed between studied metals (arsenic and lead) and principal physicochemical parameters of water based on comparison between correlation coefficients. The concentration of heavy metals in groundwater resources is dependent on several factors, including thetype and amount of agricultural pesticides, the region’s climatic conditions, the level of groundwater, and geology of region. Further studies are needed to determine the exact source(s) of contamination.Keywords: Drinking water, Heavy metals, Arsenic, Lead, Cadmium, ShahrabFor downloading the full text please click her

Sequential multilevel assimilation of inverted seismic data

We consider estimation of absolute permeability from inverted seismic data. Large amounts of simultaneous data, such as inverted seismic data, enhance the negative effects of Monte Carlo errors in ensemble-based Data Assimilation (DA). Multilevel (ML) models consist of a selection of models with different fidelities. Multilevel Data Assimilation (MLDA) attempts to obtain a better statistical accuracy with a small sacrifice of the numerical accuracy. Spatial grid coarsening is one way of generating an ML model. It has been shown that coarsening the spatial grid results in a problem with weaker nonlinearity, and hence, in a less challenging problem than the problem on the original fine grid. Accordingly, formulating a sequential MLDA algorithm which uses the coarser models in the first steps of the DA, followed by the finer models, helps to find an approximation to the solution of the inverse problem at the first steps and gradually converge to the solution. We present two variants of a sequential MLDA algorithm and compare their performance with both conventional DA algorithms and a simultaneous (i.e., using all the models on the different grids simultaneously) MLDA algorithm using numerical experiments. Both posterior parameters and posterior model forecasts are compared qualitatively and quantitatively. The results from numerical experiments suggest that all MLDA algorithms generally perform better than the conventional DA algorithms. In estimation of the posterior parameter fields, the simultaneous MLDA algorithm and one of the variants of sequential MLDA (SMLES-H) perform similarly and slightly better than the other variant (SMLES-S). While in estimation of the posterior model forecasts, SMLES-S clearly performs better than both the simultaneous MLDA algorithm and SMLES-H.publishedVersio

Fuzzy Programming for Parallel Machines Scheduling: Minimizing Weighted Tardiness/Earliness and Flow Time through Genetic Algorithm

Appropriate scheduling and sequencing of tasks on machines is one of the basic and significant problems that a shop or a factory manager encounters; this is why in recent decades extensive studies have been done on scheduling issues. One type of scheduling problems is just-in-time (JIT) scheduling and in this area, motivated by JIT manufacturing, this study investigates a mathematical model for appraising a multi-objective programing that minimize total weighted tardiness, earliness and total flowtime with fuzzy parameters on parallel machines, simultaneously with respect to the impact of machine deterioration. Besides, in this paper attempted to present a defuzzification approach and a heuristic method based on genetic algorithm (GA) to solve the proposed model. Finally, several dominant properties of optimal solutions are demonstrated in comparison with the results of a state-of-the-art commercial solver and the simulated annealing method that is followed by illustrating some instances for indicating validity and efficiency of the method

بررسی غلظت فلزات سنگین آرسنیک، کادمیوم و سرب در منابع آب زیرزمینی منطقه شهراب و روستاهای اطراف در شهرستان اردستان در خرداد 1394

Background and Aims: The increasing demand for groundwater in Iran, which is facing water shortages and lack of rainfall, is intensively ongoing. Consumption of water contaminated with heavy metals may result in adverse health effects in people. The present study aimed to determine the amount of arsenic,cadmium and lead in groundwater resources of Shahrab and its surrounding areas having a lot of drinking and agricultural water uses.Materials and Methods: A total of fourteen wells supplying rural drinking water in Shahrab area were sampled. Sampling was performed by standard methods. EC, pH and Eh were measured using a portable pH meter. Heavy metals concentration were also determined by ICP-MS. All stages of this research were conducted ethically.Results: Cadmium concentrations were less than 3 μg/L in studied samples. However, lead concentrations were more than 10 μg/L, exceeding national drinking water standards in Iran. Furthermore, arsenic concentrations exceeded national standards (10 μg/L) in three sample.Conclusion: A significant positive correlation was not observed between studied metals (arsenic and lead) and principal physicochemical parameters of water based on comparison between correlation coefficients. The concentration of heavy metals in groundwater resources is dependent on several factors, including thetype and amount of agricultural pesticides, the region’s climatic conditions, the level of groundwater, and geology of region. Further studies are needed to determine the exact source(s) of contamination.زمینه و اهداف: تقاضاي روز افزون آب زيرزميني در ایران که با مشکل کم آبی و کمبود نزولات جوی مواجه است، با شدت در حال انجام است. مصرف آب آلوده به فلزات سنگین می­تواند عوارض بهداشتی را در افراد ایجاد نماید. مطالعه حاضر با هدف تعیین میزان آرسنیک، کادمیوم و سرب در منابع آب زیرزمینی منطقه شهراب و اطراف آن که مصارف آشامیدنی و کشاورزی زیادی دارند، انجام شده است. مواد و روش­ها: از 14 چاه که  منبع تأمین آب شرب روستایی منطقه شهراب بودند، نمونه­برداری انجام شد. نمونه­ برداری با روش استاندارد انجام گرفت و پارامترهای میدانی pH, EC و Eh با  دستگاه‌های پورتابل اندازه ­گیری شد. میزان فلزات سنگین با دستگاه    ICP-MS تعیین شدند. تمام مراحل این تحقیق با رعایت موازین اخلاقی و پژوهشی انجام شد. یافته­ ها: در کلیه نمونه­ ها میزان کادمیوم کمتر از 3 میکروگرم بر لیتر و میزان سرب بیشتر از 10 میکروگرم بر لیتر اندازه گیری شد که بیشتر از حد مجاز استاندارد آب آشامیدنی ایران است. در 3 نمونه میزان آرسنیک بیش از میزان توصیه شده استاندارد کشور یعنی 10 میکروگرم بر لیتر است. نتیجه­ گیری: ضریب همبستگی بین فلزات آرسنیک و سرب و پارامترهای اصلی فیزیکوشیمیایی آب نشان داد که بین آنها و فلزات مورد بررسی همبستگی مثبت معنی­ داری مشاهده نگردید. غلظت فلزات سنگین در منابع آب زیرزمینی به عوامل متعددی وابسته است که از جمله می­توان به نوع و میزان سموم مصرفی کشاورزی، شرایط اقلیمی منطقه، سطح سفره­ های زیرزمینی و زمین­شناسی منطقه اشاره نمود. جهت تعیین دقیق منبع آلودگی احتیاج به مطالعات بیشتری می­باشد

A Nondominated Sorting Genetic Algorithm for Sustainable Reverse Logistics Network Design

Abstract Determining the appropriate strategy in recycling method that will has less pollution besides the economical process, has been signified as one of the basic principles for achieving sustainability in the supply chain due to the new legislation, environmental concerns' growth, increase volume of returns, etc. in recent years. Here will be considered a design of reverse network development for recycling waste products besides the reduction of harmful emissions due to storage, transportation and various processes. The purpose of this study investigates a multi objective optimization problem of sustainable Reverse logistics network design with the aim of management in allocating customers by coordinating facilities to ensure minimum cost as well as the environmental impact. In this work is presented a dynamic linear programming model which examines the important aspects for the design and strategic planning of a sustainable chain. Due to the complexity and differences in the nature of the model objectives, is proposed a heuristic method based nondominated sorting genetic algorithm to solve the problem. Finally, the results are discussed and analyzed

Bioactive sesquiterpene lactone from Artemisia santolina

Most species of genus Artemisia L. (Compositae) are medicinal herbswith several uses in the folk medicine worldwide. In the present study, methanol extract of Artemisia santolina has been subjected for isolation of its metabolites along with evaluation of cytotoxic activity against Artemia salina larvae. The structures of the compounds determined by 1H-and 13C-NMR, HMQC, HMBC, 1H-1H COSY and Mass spectral analysis. Two sesquiterpenes, 1,5-dihydroxy- 4(15)eudesman-12,6-olid (artemin) (1), 2-hidroxy-2,6,10-trimethyl-7,10- oxide-3,11-dodecadien-5-one (2) and one flavonoid, 5,7,4'-trihydroxy-6,3'-dimethoxyflavone (jaceosidin) (3) have been successfully characterized. Cytotoxicity of the sesquiterpene lactone (1), was assessed on Artemia salina larvae and resulted in IC50 value of 6.44 μg/mL, which was more potent compared to the positive standard berberine hydrochloride (IC50 = 26 μg/mL). In this study, the separation and identification of two sesquiterpenes and one flavone from the aerial parts of A. santolina is described. Among them the compound artemin (1) showed a toxicity effect against A. salina nauplii