NUMERIČKO ISTRAŽIVANJE NESTABILNOSTI PROTJECANJA FLUIDA U ŠUPLJIKAVOME SUSTAVU S HETEROGENOM PROPUSNOŠĆU I MOČIVOŠĆU

Quadrant geometry with permeability and wettability contrast occurs in different events, such as faults, wellbore damage, and perforation zones. In these events, understanding the dynamics of immiscible fluid displacement is vital for enhanced oil recovery. Fluid flow studies showed that viscous fingering occurs due to viscous instabilities that depend on the mobility of fluids and capillary forces. Besides, the porous domain heterogeneity is also effective on the formation of fingering. So, the purpose of the current research is to numerically investigate the effect of heterogeneity in wettability and permeability, and flow properties in Saffmann-Taylor instabilities. Numerical simulations with different flow rates in the permeability contrast model illustrated the nodal crossflow, growth of viscous fingering in the nodal part, and bypass flow in the second zone. In the wettability contrast model, a capillary fingering pattern is observed and fluid patches are isolated because of capillary force and the end effects are trapped within the quadrant. Moreover, the consequences of wettability on apparent wettability that alters the fluid-front pattern and displacement efficiency are shown.Geometrija kvadranta s razlikama u propusnosti i močivosti pojavljuje se kod rasjeda, oštećenja pribušotinske zone ili u zonama perforacija. Kod takvih pojava razumijevanje dinamike istiskivanja nemješivoga fluida bitno je za povećanje iscrpka nafte. Studije protjecanja fluida pokazale su kako se viskozno probijanje događa zbog nestabilne viskoznosti fluida, a koja ovisi o mobilnosti i kapilarnim silama. Osim toga, heterogenost šupljikavosti također utječe na probijanje fluida. Stoga je cilj bio numerički istražiti utjecaj heterogenosti močivosti i propusnosti te svojstava protoka na Saffmann-Taylorovu nestabilnost. Numeričke simulacije s različitim protjecanjima i propusnostima prikazale su križni protok i porast viskoznoga probijanja u čvorištu modela te zaobilazni protok u susjednoj zoni. Kod modela s različitom močivošću uočen je oblik kapilarnoga probijanja i sloj izoliranoga fluida, ovisno o kapilarnoj sili i obliku pojave unutar kvadranta. Na kraju je opisan utjecaj prividne na ukupnu močivost te je prikazana posljedica močivosti na prividnu močivost kao silu koja utječe na oblik fronte fluida i efikasnost istiskivanja

MODELIRANJE FRAKTURIRANOGA LEŽIŠTA MREŽOM DISKRETNIH PUKOTINA NA TEMELJU GEOMEHANIČKE OBNOVE, ANALIZA SLUČAJA IZ JUŽNOGA IRANA

Fractured reservoirs have always been of interest to many researchers because of their complexities and importance in the oil industry. The purpose of the current study is to model the fractured reservoir based on geomechanical restoration. Our target is the Arab Formation reservoir which is composed of seven limestone and dolomite layers, separated by thin anhydrite evaporate rock. First of all, in addition to the intensity, the dip, and the azimuth of the fractures, the magnitude and the direction of the stresses are determined using wireline data e.g. photoelectric absorption factor (PEF), sonic density, neutron porosity, a dipole shear sonic imager (DSI), a formation micro imager (FMI), and a modular formation dynamics tester (MDT). Then, the seismic data are interpreted and the appropriate seismic attributes are selected. One of our extracted attributes was the ant tracking attribute which is used for identifying large-scale fractures. Using this data, fractures and faults can be identified in the areas away from wells in different scales. Subsequently, the initial model of the reservoir is reconstructed. After that, the stress field and the distribution of fractures are obtained using the relationship between the stresses, the strains, and the elastic properties of the existing rocks. The model is finely approved using the azimuth and the intensity of fractures in the test well. Our findings showed that the discrete fracture network (DFN) model using geomechanical restoration was positively correlated with real reservoir conditions. Also, the spatial distribution of fractures was improved in comparison to the deterministic-stochastic DFN.Frakturirana ležišta oduvijek su bila zanimljiva istraživačima zbog njihove složenosti i važnosti za naftnu industriju te postoji više metoda razvijenih posebno za proučavanje ovoga tipa ležišta. Svrha je ovoga istraživanja modeliranje frakturiranoga ležišta na temelju geomehaničke obnove. Istraživanjem je obuhvaćeno ležište Arab unutar strukture koja se sastoji od sedam slojeva vapnenca i dolomita razdvojenih tankim slojem anhidrita. Prvo su osim podataka o intenzitetu, kutu nagiba i azimutu fraktura određene magnitude i smjerovi djelovanja naprezanja u stijeni korištenjem karotažnih podataka, poput fotoelektričnoga apsorpcijskog faktora, gustoće dobivene zvučnom karotažom, šupljikavosti dobivene neutronskom karotažom te podataka s dipolnoga akustičnog skenera, mikroelektričnoga skenera i modularnoga dinamičkog uređaja za ispitivanje stijene. Zatim su interpretirani seizmički podatci te odabrani odgovarajući seizmički atributi. Jedan od izdvojenih atributa bilo je obilježje seizmičkoga atributa koji se koristi za identificiranje velikih fraktura i rasjeda. Upotrebom tih podataka moguće je identificirati različite frakture i rasjede u područjima udaljenim od samih bušotina. Nakon toga je rekonstruiran i početni model ležišta te je dobiveno stanje naprezanja i raspodjela pukotina u stijeni na temelju odnosa između naprezanja, deformacije i elastičnih svojstava postojeće stijene. Model je u konačnici potvrđen uporabom podataka o azimutu i intenzitetu pukotina izmjerenih u testnoj bušotini. Dobiveni rezultati upućuju na dobru povezanost između modela diskretne mreže fraktura koja se koristi geomehaničkom rekonstrukcijom sa stvarnim uvjetima u ležištu. Također je poboljšana i prostorna raspodjela pukotina u usporedbi s determinističko-stohastičkom diskretnom mrežom. Obnovljeni (restaurirani) model poboljšao je i prostornu raspodjelu te doveo do boljega donošenja odluka kod bušenja, projektiranja bušotine te simulacija toka fluida

Identifying and Prioritizing of Readiness Factors for Implementing ERP Based on Agility (Extension of McKinsey 7S Model)

Studies conducted by many researchers indicate high failure rate of projects of implementing ERP systems. To penetrate in global competition market, it seems necessary to carry out studies to assess organizational readiness prior to system implementation to identify weaknesses and strengths points of the organization. Furthermore, organizations should be agile to be able to respond to market changes fast and effectively to survive in competitive environment. ERP and agility are two important tools for achieving competitive advantages. The main goal of the present study was to identify and prioritize organizational readiness factors for implementing ERP based on organizational agility. In this study, along with extension of McKinsey 7S model (strategy, structure, systems, skills, style, staff, shared values) to 9S (7S+ self-evaluation and supportive factors) model, agility criteria were weighted and rated using group AHP with fuzzy logic approach; so that accountability, speed and flexibility have obtained the maximum score. The nine organizational readiness factors were ranked using integrated FAHP and TOPSIS method based on five criteria of agility. The framework was proposed to a real case of Shiraz distribution cooperative firms. Results showed that among the nine organizational dimensions based on agility, the two added to McKinsey dimensions (self-evaluation and supportive factors) are ranked in the first and fourth places. The proposed framework help the firms “to implement ERP system with agility approach” concentrate on effective empowerments and develop strategies based on their own priority

An Assessment of Readiness Factors for Implementing ERP Based on Agility (Extension of Mckinsey 7s Model)

Studies conducted by many researchers indicate high failure rate of projects of implementing ERP systems. Furthermore, organizations should be agile to be able to respond to market changes fast and effectively to survive in competitive environment. ERP and agility are two important tools for achieving competitive advantages. The main goal of the present study was to identify and prioritize organizational readiness factors for implementing ERP based on organizational agility. In this study, along with extension of McKinsey 7S model (strategy, structure, systems, skills, style, staff, shared values) to 9S (7S+ self-evaluation and supportive factors) model, agility criteria were weighted and rated using group AHP with fuzzy logic approach; so that accountability, speed and flexibility have obtained the maximum score. The nine organizational readiness factors were ranked using integrated FAHP and TOPSIS method based on five criteria of agility. The framework was proposed to a real case of Shiraz distribution cooperative firms. Results showed that among the nine organizational dimensions based on agility, the two added to McKinsey dimensions (self-evaluation and supportive factors) are ranked in the first and fourth places. The proposed framework help the enterprises “to implement ERP system with agility approach” concentrate on change management and develop strategies based on their own priority

High Seroprevalence of Anti-H. pylori Antibodies in Patients with Ventilator Associated Pneumonia

Background: Despite major advances in the management of ventilator-associated pneumonia, its pathogenesis is not clearly known. Recently, the role of gastric colonization has been proposed. We compared the prevalence of H. pylori by serology in patients with VAP and in control subjects to determine the role of H. pylori and gastric colonization in the pathogenesis of VAP. Methods:118 intubated and mechanically ventilated patients were included and divided into two groups; 59 subjects with VAP and 59 control patients. Results of the serologic tests, demographic characteristics and time of blood sampling were registered. Results: Mean age in seropositive patients was significantly higher. 71.2% in the VAP group and 61.01% in controls were IgG seropositive (P=0.24). IgM seropositivity was 23.73% versus 8.47% in VAPs and controls, respectively (P=0.024). By increasing the time of intubation, more patients became seropositive for IgM (Pearson’s correlation coefficient=0.4, P=0.002). Conclusion:  IgM seropositivity and serum level were significantly higher in VAP patients. Also by increasing the duration of intubation and time of sampling, serum levels and seropositivity for IgM increased significantly

A comparative study on the effect of blood collection tubes on stress oxidative markers

Oxidative stress has a major role in disease pathogenesis. However, limited studies have investigated the effect of various sample collection tubes on oxidative biomarkers. The present study aimed to evaluate the effect of different collection tubes on the variation of malondialdehyde (MDA), nitric oxide (NO), total thiol (t-SH), and ferric reducing ability of plasma (FRAP) levels. A total of 35 individuals participated in this study and each collected sample was separated into three different tubes: glass tubes (GTs), plain plastic tubes (PTs), and gel separator tubes (GSTs). The results of PTs and GSTs were compared to those of GTs as the reference tube. The comparison between the means of biomarkers in various tubes indicated that there was no significant difference in MDA results between tubes. In contrast, t-SH and NO content were significantly decreased in GSTs and PTs compared to GTs. However, the Bland-Altman analysis showed an acceptable concordance for the mentioned analytes and the statistically significant differences were not clinically significant for NO, MDA, and t-SH antioxidant parameters. Moreover, the FRAP level was considerably lower in GSTs compared to GTs. Nevertheless, the Bland-Altman analysis showed a high bias percentage for the FRAP assay when using PTs and GSTs. According to the present results, it can be concluded that switching to plastic blood collection tubes or serum separation tubes could influence the FRAP results. However, there was no interference for the interpretation of other antioxidant assays in different types of collection tubes. Hence, it is suggested to use GTs for total antioxidant capacity evaluations, especially the FRAP assay

Differential privacy preserved federated transfer learning for multi-institutional 68Ga-PET image artefact detection and disentanglement.

PURPOSE Image artefacts continue to pose challenges in clinical molecular imaging, resulting in misdiagnoses, additional radiation doses to patients and financial costs. Mismatch and halo artefacts occur frequently in gallium-68 (68Ga)-labelled compounds whole-body PET/CT imaging. Correcting for these artefacts is not straightforward and requires algorithmic developments, given that conventional techniques have failed to address them adequately. In the current study, we employed differential privacy-preserving federated transfer learning (FTL) to manage clinical data sharing and tackle privacy issues for building centre-specific models that detect and correct artefacts present in PET images. METHODS Altogether, 1413 patients with 68Ga prostate-specific membrane antigen (PSMA)/DOTA-TATE (TOC) PET/CT scans from 3 countries, including 8 different centres, were enrolled in this study. CT-based attenuation and scatter correction (CT-ASC) was used in all centres for quantitative PET reconstruction. Prior to model training, an experienced nuclear medicine physician reviewed all images to ensure the use of high-quality, artefact-free PET images (421 patients' images). A deep neural network (modified U2Net) was trained on 80% of the artefact-free PET images to utilize centre-based (CeBa), centralized (CeZe) and the proposed differential privacy FTL frameworks. Quantitative analysis was performed in 20% of the clean data (with no artefacts) in each centre. A panel of two nuclear medicine physicians conducted qualitative assessment of image quality, diagnostic confidence and image artefacts in 128 patients with artefacts (256 images for CT-ASC and FTL-ASC). RESULTS The three approaches investigated in this study for 68Ga-PET imaging (CeBa, CeZe and FTL) resulted in a mean absolute error (MAE) of 0.42 ± 0.21 (CI 95%: 0.38 to 0.47), 0.32 ± 0.23 (CI 95%: 0.27 to 0.37) and 0.28 ± 0.15 (CI 95%: 0.25 to 0.31), respectively. Statistical analysis using the Wilcoxon test revealed significant differences between the three approaches, with FTL outperforming CeBa and CeZe (p-value < 0.05) in the clean test set. The qualitative assessment demonstrated that FTL-ASC significantly improved image quality and diagnostic confidence and decreased image artefacts, compared to CT-ASC in 68Ga-PET imaging. In addition, mismatch and halo artefacts were successfully detected and disentangled in the chest, abdomen and pelvic regions in 68Ga-PET imaging. CONCLUSION The proposed approach benefits from using large datasets from multiple centres while preserving patient privacy. Qualitative assessment by nuclear medicine physicians showed that the proposed model correctly addressed two main challenging artefacts in 68Ga-PET imaging. This technique could be integrated in the clinic for 68Ga-PET imaging artefact detection and disentanglement using multicentric heterogeneous datasets

Neonatal, infant, and under-5 mortality and morbidity burden in the Eastern Mediterranean region: findings from the Global Burden of Disease 2015 study

Objectives Although substantial reductions in under-5 mortality have been observed during the past 35 years, progress in the Eastern Mediterranean Region (EMR) has been uneven. This paper provides an overview of child mortality and morbidity in the EMR based on the Global Burden of Disease (GBD) study. Methods We used GBD 2015 study results to explore under-5 mortality and morbidity in EMR countries. Results In 2015, 755,844 (95% uncertainty interval (UI) 712,064–801,565) children under 5 died in the EMR. In the early neonatal category, deaths in the EMR decreased by 22.4%, compared to 42.4% globally. The rate of years of life lost per 100,000 population under 5 decreased 54.38% from 177,537 (173,812–181,463) in 1990 to 80,985 (76,308–85,876) in 2015; the rate of years lived with disability decreased by 0.57% in the EMR compared to 9.97% globally. Conclusions Our findings call for accelerated action to decrease child morbidity and mortality in the EMR. Governments and organizations should coordinate efforts to address this burden. Political commitment is needed to ensure that child health receives the resources needed to end preventable deaths

Global, regional, and national burden of traumatic brain injury and spinal cord injury, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016.

Traumatic brain injury (TBI) and spinal cord injury (SCI) are increasingly recognised as global health priorities in view of the preventability of most injuries and the complex and expensive medical care they necessitate. We aimed to measure the incidence, prevalence, and years of life lived with disability (YLDs) for TBI and SCI from all causes of injury in every country, to describe how these measures have changed between 1990 and 2016, and to estimate the proportion of TBI and SCI cases caused by different types of injury. METHODS: We used results from the Global Burden of Diseases, Injuries, and Risk Factors (GBD) Study 2016 to measure the global, regional, and national burden of TBI and SCI by age and sex. We measured the incidence and prevalence of all causes of injury requiring medical care in inpatient and outpatient records, literature studies, and survey data. By use of clinical record data, we estimated the proportion of each cause of injury that required medical care that would result in TBI or SCI being considered as the nature of injury. We used literature studies to establish standardised mortality ratios and applied differential equations to convert incidence to prevalence of long-term disability. Finally, we applied GBD disability weights to calculate YLDs. We used a Bayesian meta-regression tool for epidemiological modelling, used cause-specific mortality rates for non-fatal estimation, and adjusted our results for disability experienced with comorbid conditions. We also analysed results on the basis of the Socio-demographic Index, a compound measure of income per capita, education, and fertility. FINDINGS: In 2016, there were 27·08 million (95% uncertainty interval [UI] 24·30-30·30 million) new cases of TBI and 0·93 million (0·78-1·16 million) new cases of SCI, with age-standardised incidence rates of 369 (331-412) per 100 000 population for TBI and 13 (11-16) per 100 000 for SCI. In 2016, the number of prevalent cases of TBI was 55·50 million (53·40-57·62 million) and of SCI was 27·04 million (24·98-30·15 million). From 1990 to 2016, the age-standardised prevalence of TBI increased by 8·4% (95% UI 7·7 to 9·2), whereas that of SCI did not change significantly (-0·2% [-2·1 to 2·7]). Age-standardised incidence rates increased by 3·6% (1·8 to 5·5) for TBI, but did not change significantly for SCI (-3·6% [-7·4 to 4·0]). TBI caused 8·1 million (95% UI 6·0-10·4 million) YLDs and SCI caused 9·5 million (6·7-12·4 million) YLDs in 2016, corresponding to age-standardised rates of 111 (82-141) per 100 000 for TBI and 130 (90-170) per 100 000 for SCI. Falls and road injuries were the leading causes of new cases of TBI and SCI in most regions. INTERPRETATION: TBI and SCI constitute a considerable portion of the global injury burden and are caused primarily by falls and road injuries. The increase in incidence of TBI over time might continue in view of increases in population density, population ageing, and increasing use of motor vehicles, motorcycles, and bicycles. The number of individuals living with SCI is expected to increase in view of population growth, which is concerning because of the specialised care that people with SCI can require. Our study was limited by data sparsity in some regions, and it will be important to invest greater resources in collection of data for TBI and SCI to improve the accuracy of future assessments

Mapping 123 million neonatal, infant and child deaths between 2000 and 2017

Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained rates of 25 or fewer child deaths per 1,000 live births by 2017, and that 58% of child deaths between 2000 and 2017 in these countries could have been averted in the absence of geographical inequality. This study enables the identification of high-mortality clusters, patterns of progress and geographical inequalities to inform appropriate investments and implementations that will help to improve the health of all populations