Prediction of asphaltene precipitation upon injection of various gases at near-wellbore conditions: A simulation study using PC-SAFT EoS

International audienceThe depletion of oil reservoirs and increased global oil demand have given impetus to employ various secondary and tertiary oil recovery methods. Gas injection is widely used in both secondary and tertiary modes, though the major problem associated with this process is the precipitation and deposition of asphaltene, particularly at near-wellbore conditions. In-depth knowledge of asphaltene phase behavior is therefore essential for the prediction of asphaltene precipitation. Previous studies reported the impact of gas injection on asphaltene phase behavior, but the knowledge of precipitation of asphaltene as a function of different mole fractions of injected gas is also imperative. In this study, the thermodynamic model of PC-SAFT EoS is used to discern the phase equilibrium of asphaltene by analyzing the asphaltene drop-out curve during gas injection. Asphaltene drop-out curves of two different live oil samples are analyzed by injecting CO2, CH4, and N2 gases at different mole percentages and temperatures. The results revealed that PC-SAFT EoS can serve as a reliable tool for estimating bubble pressure and asphaltene onset pressure for a wide range of temperatures, pressures, and compositions. The simulation results for the injection of CO2, CH4, and N2 also showed that CO2 gas gives minimum asphaltene precipitation. It reduces the size of the drop-out curve or moves it toward higher pressures. CH4 and N2 expand the drop-out curve by raising the upper onset point. CH4 increases the maximum point of the drop-out curve for two types of oil studied (A and B) at two different temperatures. N2 raises the maximum point of oil type “A” by approximately 57% at 395 K, while it has no effect on the maximum point of oil type “B”. In addition, reducing the temperature resulted in either decrease or increase of asphaltene solubility, demonstrating that the impact of temperature on asphaltene precipitation is closely related to the composition of the crude

Effect of continuous aerobic training and high-intensity interval training on some anthropometric indicators of overweight and obese military personnel

Overweight and obesity are associated with an increased risk of cardiovascular disease, hypertension and type 2 diabetes. The purpose of this study was to determine the effect of two continuous aerobic training and high-intensity interval training on body weight, body mass index, waist to hip ratio, and body fat percentage in overweight and obese military people. In this quasi-experimental study, 30 overweight or obese military personnel stationed in a military center were divided into two equal groups of 15 subjects within continuous aerobic training group and high-intensity interval training group. The training protocol consisted of six weeks of continuous aerobic training and high intensity interval training performed every week for three sessions and each session for 60 minutes with equal intensity. The research variables included body weight, body mass index, waist to hip ratio and body fat percentage, which were measured in the same and standard conditions in two stages of pre-test and post-test. After 6 weeks of intervention, high-intensity interval training group showed a significant reduction in body mass index, waist-hip ratio and body fat percentage compared to the continuous aerobic training group(P<0.05). However, there was no significant change in the body weight of the subjects (P<0.05). The results of this study showed that the high-intensity interval training protocol had a greater effect on the body composition parameters of the subjects compared to the continuing aerobic exercise protocol, so it could be included in the training program for overweight or obese military persons

Zataria multiflora Essential oil Prevent Iron Oxide Nanoparticles-induced Liver Toxicity in Rat Model

Over loading of iron oxide nanoparticles can causes the liver injury through overproduction of free radicals. Zataria multiflora Boiss. (Lamiaceae) has been used for many years in folk medicine due to its antioxidant and antibacterial activities. This study evaluates -for the first time- the effect of Z. multiflora essential oil (EO) against iron oxide nanoparticles hepatotoxicity in rat model. Male Wistar rats were divided randomly into 4 groups; control group (C), non-treated control group (NT), treatment groups, nanoparticles plus Z. multiflora EO at 100 and 200 mg/kg b.w. In following, the liver and blood tissue were collected for estimating antioxidant / oxidative stress parameters including lipid peroxidation (LP), glutathione (GSH), glutathione-S-transferase (GST), and liver enzyme asparate transaminase (AST) and also histopathological examinations. Iron oxide nanoparticles toxicity produced a significant increase in the levels of LP, ferric reducing ability of plasma (FRAP), and AST activity concomitant with decrease in the levels of GSH and GST activity compared to the control group. However, in the treatment groups received Z. multiflora EO, the levels of LP and AST activity reduced together with increasing in GSH content and GST activity were significantly reported. Histopathological studies also supported the biochemical assessments indicating hepatic improvements induced by nanoparticles. Z. multiflora EO protected the liver from injuries induced by iron oxide nanoparticles which can be correlated with its antioxidant activities. This can be a valuable candidate in modulating the oxidative hepatic injuries

Potential Protective Effect of Pretreatment with Caraway Essential Oil in vivo Model of Iron Nanoparticle-induced Liver Injury

Recently, there has been a great deal of interest in the use of the medicinal plants with high antioxidant compounds for curing liver injuries induced by hepatoxcitic agents. This study was to assess the protective effect of Carum carvi L. essential oil (E.O) on the hepatoxitic rats induced by overdose of iron oxide nanoparticles (NPs). The rats were distributed to 4 groups. In negative control group (NC), the rats received normal saline and DMSO daily for 3 days. In control group (C), iron oxide nanoparticles (Fe2O3) (200 mg/kg b.w) was injected daily for 3 days. In the treatment groups, iron oxide nanoparticles plus E.O at 100 & 200 mg/kg b.w were injected daily for 3 days. In following, cytochrome P450 (CYP450), glutathione S-transferase (GST), glutathione (GSH), aspartate transaminase (AST), alkaline phosphatase (ALP) and alanine transaminase (ALT) were estimated at 72 h after NP-treatment. The administration of the E.O could return considerably the decrease of the GST and GSH levels as well as the increase of the level of AST induced by iron oxide NPs. These results are in agreement with histopathological results. The data indicated that E.O provided an efficient prevention against iron oxide NPs-induced hepatotoxicity in rats

A Comparative Analysis of Clinical Characteristics and Laboratory Findings of COVID-19 between Intensive Care Unit and Non-Intensive Care Unit Pediatric Patients: A Multicenter, Retrospective, Observational Study from Iranian Network for Research in Viral

Introduction: To date, little is known about the clinical features of pediatric COVID-19 patients admitted to intensive care units (ICUs).&nbsp;Objective: Herein, we aimed to describe the differences in demographic characteristics, laboratory findings, clinical presentations, and outcomes of Iranian pediatric COVID-19 patients admitted to ICU versus those in non-ICU settings.&nbsp;Methods: This multicenter investigation involved 15 general and pediatrics hospitals and included cases with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection based on positive real-time reverse transcription polymerase chain reaction (RT-PCR) admitted to these centers between March and May 2020, during the initial peak of the COVID-19 pandemic in Iran.&nbsp;Results: Overall, 166 patients were included, 61 (36.7%) of whom required ICU admission. The highest number of admitted cases to ICU were in the age group of 1–5 years old. Malignancy and heart diseases were the most frequent underlying conditions. Dyspnea was the major symptom for ICU-admitted patients. There were significant decreases in PH, HCO3 and base excess, as well as increases in creatinine, creatine phosphokinase (CPK), lactate dehydrogenase (LDH), and potassium levels between ICU-admitted and non-ICU patients. Acute respiratory distress syndrome (ARDS), shock, and acute cardiac injury were the most common features among ICU-admitted patients. The mortality rate in the ICU-admitted patients was substantially higher than non-ICU cases (45.9% vs. 1.9%, respectively; p&lt;0.001).&nbsp;Conclusions: Underlying diseases were the major risk factors for the increased ICU admissions and mortality rates in pediatric COVID-19 patients. There were few paraclinical parameters that could differentiate between pediatrics in terms of prognosis and serious outcomes of COVID-19. Healthcare providers should consider children as a high-risk group, especially those with underlying medical conditions

SF2A-2009: Semaine de l'Astrophysique Francaise

National audienc

SF2A-2009: Semaine de l'Astrophysique Francaise

National audienc