Valorization of waste cooking oil based biodiesel for biolubricant production in a vertical pulsed column: Energy efficient process approach

International audienceDevelopment of bio-based lubricants have received growing interest as sustainable substitutes to petroleum-based lubricants due to their renewability, biodegradability and superior physicochemical properties. Biolubricant production from waste cooking oil in an intensified reactor, which is designed with the aim of scaling-up for industrial purposes, can effectively decrease the cost of finished product. In this study, a vertical pulsed column with tri-orifice baffles was applied to produce trimethylolpropane fatty acid triester (biolubricant) from waste cooking oil, which is a cost and environmentally effective feedstock. This type of reactor enables high interfacial areas between immiscible reactants, leading to improved reaction performance. In addition, response surface methodology was used to optimize the levels of different operating parameters to obtain the highest reaction yield and the lowest power consumption. An optimal reaction yield of 83.3% and power consumption of 1006 kW/m 3 were obtained with an oscillation frequency of 3.6 Hz, a baffle spacing of 1.45d e , a molar ratio of 4:1 and a potassium carbonate catalyst loading of 1%

Prediction of Solvent Effect on Asphaltene Precipitation at Reservoir Conditions

The aim of the current study is to evaluate the effects of inhibitors or solvents on asphaltene precipitation under reservoir conditions. To this end, the interaction between live oil and solvent, and its side effects on precipitated/dissolved asphaltene were predicted via Miller’s entropy modified polymer solution theory under reservoir conditions. Then, the adjustable parameters of the model were tuned using experimental the data of asphaltene precipitation within a live oil sample. The obtained adjusted parameters were considered to monitor the effects of solvent injection, miscible gas injection, and natural depletion on asphaltene deposition through an oil sample. Finally, Peng-Robinson equation of state was applied to calculate vapor-liquid equilibrium conditions. The results showed that the output of the model was really in good agreement with all experimental, field, and theoretical data

Static Modeling of Oil Field Mineral Scales: Software Development

Mineral scale deposition in near wellbore regions of injection wells is one of the main challengeable issues during the water injection process, which magnifies the importance of robust models in predicting the amount of mineral scale deposition such as calcium sulfate. One of the main challenges of CaSO4 scale is in carbonated reservoirs, in which sensitive behavior is observed in related to the contribution of both calcium and sulfate ions in carbonated and sulfated scale reactions. This defect is mirror of wrong procedure and value in the estimation of first kind/value of precipitant contributed in scale deposition reactions (ions competition) as well as inconsistent temperature/pressure dependent coefficients of prediction model. The objective of this study is to develop a model that can accurately predict the formation and amount of CaSO4 scale as the dominant scale in multicomponent aqueous systems by three major tools, namely utilization the best temperature- and pressure-dependent thermodynamic interactive ion coefficients (MSE Model: Pitzer), developing our fine-tuned iterative mathematical solver, and verification of the results of the model by accurate experimental data. The results showed that at the optimum value of precipitant (10%) in scale deposition reactions and by defining the best temperature- and pressure-dependent coefficients, we can attain the best accuracy in the prediction of CaSO4 scale deposited amount (less than 0.06% as a relative error compared to 36% overestimation and 22% underestimation in commercial software). The output of this study is developed software leading to the more accurate prediction of the amount of promising scales in near wellbore regions or pipelines

Optimization of methyl ester production from waste cooking oil in a batch tri-orifice oscillatory baffled reactor

Transesterification of vegetable oils is a common route for the production of biodiesel. This reaction is a slow mass transfer limited reaction that has been shown to benefit from process intensification reactors such as the Oscillatory Baffled Reactor (OBR). The use of waste cooking oil as a resource is an attractive alternative to other virgin vegetable oils that will enable the capital costs of biodiesel production to be largely decreased, thereby making biodiesel an affordable and competitive fuel. In this study, optimization of biodiesel, or fatty acid methyl ester (FAME) production from waste cooking oil (WCO) was investigated using a batch OBR (diameter = 0.06 m, height = 0.55 m) with multi-orifice baffles, which have been recommended for scale-up. Response Surface Methodology (RSM) was applied to study the effects and interaction of different operating parameters: oscillation frequency (in the range 2.4–4.9 Hz), inter-baffle spacing (in the range 0.05–0.09 m) and reaction temperature (in the range 40–60 °C). It was found that temperature is the main factor influencing reaction yield and the interaction between temperature and oscillation frequency is non-negligible. Inter-baffle spacing does not, however, have a significant effect on the reaction. This is different from the design recommendations of OBRs in the literature, which were originally developed for single orifice baffles. An optimal reaction yield of 81.9% was obtained with an oscillation frequency of 4.1 Hz and an inter-baffle spacing of 5 cm (i.e. approximately 1.5de) at a temperature of 60 °C. However, similar reaction yields could be obtained for different values of inter-baffle spacing

Study of the Epidemiology and Use of Condoms in Vulnerable Women Referring to Damage Reduction Centers in Shiraz During 2015-2016

Background and aims: Female sex workers (FSWs) play an essential role in the transmission of HIV and are considered critical groups compared to the public groups of society and their customers. Therefore, this study was conducted to investigate the status of sexual intercourse among prostitutes in Shiraz in 2015-2016. Methods: This is a cross-sectional study conducted on 162 prostitutes referred to Shiraz transitional damage reduction centers and the information was gathered through a checklist. Results: The results showed that the mean age at the first vaginal intercourse was 16.57±3.65. In 62.3 of people, the main reason for prostitution was the need for money to help the family. It was also found that 39.5 of prostitutes had anal sex, and more than 95 of them did not use condoms during sex. There was also a statistically significant relationship (P<0.01) between the age of sexual intercourse and education level. Conclusion: The results of this study demonstrated that prostitutes initiated the first sexual intercourse at a very young age, and increase in the education level postponed the first sexual intercourse. Otherwise stated, the first sexual intercourse can be delayed by increasing the level of education

Teaching Metacognitive strategies on Metacognitive Behavior and Internet Self-Efficacy of Female Students at Risk of Internet Addiction during the COVID-19

Background: Adolescents, for whom the Internet is an indispensable part of their daily life, are the most significant group at risk of Internet addiction. The objective of this study was to investigate the effectiveness of metacognitive strategies on metacognitive behavior and internet self-efficacy of female students at risk of Internet addiction during the COVID-19. &nbsp; Methods:&nbsp; &nbsp;&nbsp;The present research was quasi-experimental with pretest-posttest design with a control group. The statistics population for the academic year 2020-2021 comprised all secondary schools' females in Tehran's 15 district. In this study, purposeful sampling process was applied. Primarily, one school (Ebne Sina) was randomly selected from the secondary schools of region 15 in Tehran, in the second grade. Three classes were chosen from each grade in the form of Lottery and among 360 students, 30 students who were most at risk for internet addiction were randomly selected and assigned in the experimental (n=15) and control (n=15) groups via shad application. The experimental group received metacognitive strategies training for 8 treatment sessions (90 minutes for each session). The data were analyzed with SPSS-23 and &nbsp;analysis of covariance (ANCOVA).&nbsp; &nbsp; Results: Mean and SD of age in the Transactional Analysis and the control groups were 15.87 ± 0.734 and 16±0.816, respectively. Moreover, our findings showed that the experimental and control groups differ significantly in their metacognitive behavior (p =0.01and F=55.349) and internet use self-efficacy during pretest control (p =0.01 and F=43.573). &nbsp; Conclusions: The result of our study showed that metacognitive strategies had significant effects on Metacognitive Behavior and Internet self-efficacy of female students at risk of Internet addiction during the COVID-19.&nbsp; Therefore, psychological group therapy could be suggested to improve metacognitive behavior and increase internet self-efficacy and thus reduce behavioral and social damages. keywords: Teaching metacognitive strategies, Metacognitive Behavior, Internet Self-Efficacy, Female students, Internet addictio

Comparative evaluation of prophylactic single-dose intravenous antibiotic with postoperative antibiotics in elective urologic surgery

Mohammad K Moslemi1, Seyed M Moosavi Movahed2, Akram Heidari3, Hossein Saghafi2, Mehdi Abedinzadeh41Department of Urology, 2Department of Nephrology, 3Department of Health, Kamkar Hospital, Qom University of Medical Sciences, Qom, Iran; 4Department of Urology, Moradi Hospital, School of Medicine, Rafsanjan University of Medical Sciences, Rafsanjan, IranBackground: Unrestricted antibiotic use is very common in Iran. As a result, emergence of resistant organisms is commonplace. Antibiotic prophylaxis in surgery consists of a short antibiotic course given immediately before the procedure in order to prevent development of a surgical site infection. The basic principle of prophylaxis is to maintain effective concentrations of an antibiotic active against the commonest pathogens during the entire surgery.Materials and methods: We prospectively investigated 427 urologic surgery cases in our department between August 2008 and September 2009 (Group1). As reference cases, we retrospectively reviewed 966 patients who underwent urologic surgery between May 2004 and May 2008 (Group 2) who were administered antibiotics without any restriction. Prophylactic antibiotics such as cefazolin were administered intravenously according to our protocol. Postoperative body temperature, peripheral white blood cell counts, urinalysis, and urine culture were checked.Results: To judge perioperative infections, wound condition and general condition were evaluated in terms of surgical site infection, as well as remote infection and urinary tract infection, up to postoperative day 30. Surgical site infection was defined as the presence of swelling, tenderness, redness, or drainage of pus from the wound, superficially or deeply. Remote infection was defined as occurrence of pneumonia, sepsis, or urinary tract infection. Perioperative infection rates (for surgical site and remote infection) in Group 1 and Group 2 were nine of 427 (2.6%) and 24 of 966 (2.5%), respectively. Surgical site infection rates of categories A and B in Group 1 were 0 and two (0.86%), respectively, while those in Group 2 were 0 and five (0.92%), respectively. There was no significant difference in infection rates in terms of remote infection and surgical site infection between Group 1 and Group 2 (P = 0.670). The amounts, as well as the prices, for intravenously administered antibiotics decreased to approximately one quarter.Conclusion: Our protocol effectively decreased the amount of antibiotics used without increasing perioperative infection rates. Thus, our protocol of prophylactic antibiotic therapy can be recommended as an appropriate method for preventing perioperative infection in urologic surgery. Keywords: surgical site infection, antibiotic prophylaxis, single dose, urologic surger

Possibility of the blood clot, thrombotic thrombocytopenia following injection of COVID-19-vaccine AstraZeneca; a systematic review

Introduction: Recently, it has been reported that the injection of vaccines such as the ChAdOx1 nCoV-19 (AstraZeneca) involves some rare cases of thrombocytopenia and blood clots, although the vaccines created immunity in people. Estimates of this phenomenon are not the same in different countries, probably due to age distribution and number. Objectives: This study attempted to study AstraZeneca’s rare side effects in people injected with this vaccine. Methods: This systematic study was conducted using articles published in 2021 under the title of blood clot and thrombocytopenia by AstraZeneca injection. The references and data were gathered through national and international sites such as Magiran, Google Scholar, PubMed, Web of Science, and Scopus. They were also gathered and examined using report cases and the available data on COVID-19 vaccine immunization in various countries. The keywords used mainly are COVID-19 vaccine, ChAdOx1 nCoV-19 vaccine, blood clots, thrombus, thrombotic, and thrombocytopenia. Eventually, 25 articles were searched and examined, of which 15 related ones were selected after reviewing and re-studying. While investigating the summary and method in those 15, they were filtered more accurately; finally, ten articles were chosen. Inclusion criteria consisted of all related articles and exclusion criteria contained articles that were less related to our research subject after purification or were redundant and not of high quality. Results: This study found that rare blood clot cases and thrombocytopenia were seen despite mild side effects after AstraZeneca injection. After assessing its benefits, adverse effects, and age distribution, the countries using AstraZeneca decided to continue using it. The main difference in reported statistics in these countries is due to the variety in the age and number of people receiving the vaccine. Conclusion: Blood clots and thrombocytopenia are among the rare side effects of the AstraZeneca vaccine. In different countries, the vaccine side effects vary depending on the age and number of participants. Anyway, according to the investigations conducted in this area, the highest records of these side effects are observed in Norway, which is still low. Overall, through studying this study and other similar ones, politicians, managers, and even ordinary people can be informed about the pros and cons of this vaccine

Determining the Concentration of Particulate Matters and Microbiological Quality of Indoor Air in Intensive Care Units of Kashan Hospital, Iran

Introduction: Maintaining hospital air quality is very important, especially in intensive care units (ICUs), where patients undergo invasive procedures. Therefore, the present study was conducted with the aim of determining the relationship between particulate matters (PMs) and bioaerosols in pediatric ICU (PICU), neonatal ICU (NICU), and ICU open heart (ICU OH) of Shahid Beheshti Hospital in Kashan. Materials and Methods: This cross-sectional study was conducted for six consecutive months, i.e., autumn and winter of 2021. PM samples were taken using a Grimm Dust Monitor and microbial samples were taken using a Quick Take 30 sampler. Kolmogorov-Smirnov test was used for analysis and then ANOVA and LSD were used for further tests. Results: The maximum and minimum PM10 concentrations in the PICU and ICU OH were 59.19 and 9.71 μg/m3, respectively; and the maximum and minimum PM2.5 concentrations were 20.23 μg/m3 in the NICU and 4.69 μg/m3 in PICU. The mean PM concentration and the number of bacterial and fungal colonies were consistent with the WHO and EPA guidelines. Gram-positive Staphylococcus were the most abundant bacteria (90.96%). The most abundant fungi were Aspergillus (54.23%), Penicillium (15.64%), and Cladosperium (12.17%) species. There was also no significant relationship between PMs and bioaerosols. Conclusion: The mean concentrations of PMs and bioaerosols match with the guidelines, which can be attributed to more observance of health protocols and restrictions on the movement of people into ICUs due to the COVID-19 outbreak