Optimization of biodiesel production from waste cooking oil using ion exchange resins

Waste cooking oil is a potential alternative of refined vegetable oil for biodiesel production due to its low cost and elimination of its disposal problem. The concentration of free fatty acids (FFAs) in WCO dictates the type of chemical treatment required for biodiesel production: a single esterification reaction is considered at high content of FFAs, whereas, a combination of estrification and transestrification reaction is used at moderate content of FFAs. In this study, optimization of esterification process of FFAs in artificially acidified soybean oil with oleic acid combined with methanol as an agent and ion exchange resin as a heterogeneous catalyst was carried out. The optimization process was performed by means of Matlab software based on a kinetic model available in the literature. Conversion of acidified oil was determined as an objective function in correlation with reaction variables i.e., temperature and catalyst weight. It is found that the maximum conversion of the free acids is 95.95% which is achievable at 4.48 g catalyst loading and reaction temperature of 120°C

Comparing the validity of EEG in epileptic patients with and without activation methods

چکیده: زمینه و هدف: متداول ترین راه تشخیص پاراکلینیکی صرع، نوار مغزی (EEG) می باشد. ولی به اینکه موارد منفی کاذب در این روش تشخیصی نسبتاً زیاد می باشد (در بعضی از انواع صرع حتی تا 40) لذا روشهای مختلف فعال سازی (Activation) جهت کم شدن این موارد منفی پیشنهاد شده است. این مطالعه با هدف مقایسه میزان روایی در حالت فعال سازی و بدون فعال سازی نوار مغزی در بیماران صرعی انجام شد. روش بررسی: این مطالعه کلینیکی بر روی 500 بیمار اپی لپتیک که صرع آنها از نظر کلینیکی مسلم بود انجام شد. پس از انجام نوار مغزی اولیه، بیماران با نوار مغزی غیر طبیعی کنار گذاشته شده و بیمارانی که علیرغم بیماری، نوار مغزی طبیعی داشتند به صورت تصادفی در 5 گروه، (یک گروه شاهد و 4 گروه مورد) مورد نوار برداری مجدد با مدل های مختلف فعال سازی شامل تنفس عمیق و تند (HV)، تحریک نوری (PS)، خواب و محرومیت از خواب قرار گرفتند و مجدداً EEG شدند. سپس داده ها با استفاده از آزمون آماری کای دو و دقیق فیشر تجزیه و تحلیل شد. یافته ها: از جمع 500 نفر کل بیماران 386 نفر (2/77) EEG غیر طبیعی و 114 نفر EEG طبیعی داشتند. در گروه شاهد هیچ مورد مثبت گزارش نگردید. آزمون دقیق فیشر نشان داد که فعال سازی در مثبت شدن EEG موثر بود (01/0P). استفاده از مدل های مختلف فعال سازی در صرع تونیک – کلونیک، 3/3، Absence 5/9 و دیگر انواع صرع 45/12 موارد منفی کاذب را کاهش داد. نتیجه گیری: بر اساس نتایج گرچه EEG بهترین راه تشخیص پاراکلینیکی انواع صرع می باشد ولی چنانچه بطور معمول و بدون فعال سازی انجام گیرد، منفی کاذب زیادی در آن دیده می شود و چنانچه مدل های مختلف فعال سازی انجام گیرد، روایی بیشتری می توان از آن انتظار داشت

Seroprevalence of hepatitis B virus and its co-infection with hepatitis D virus and hepatitis C virus in Iranian adult population

Context: Hepatitis B virus (HBV) infection is one of the most prevalent public health problems worldwide (especially in developing countries). Aims: This study was carried out to determine the seroprevalence of HBV and its co-infection with hepatitis D (HDV) and C (HCV) viruses in the northeastern part of Iran. Setting and Design: A population-based cross-sectional study in Iran. Materials and Methods: As many as 1,850 subjects were explored for HBsAg. Anti-HDV and anti-HCV antibodies were assessed in HBsAg-positive cases. Statistical Analysis Used: Proportions were compared by Chi-square and Fisher's exact tests. Results: The mean age of subjects was 43.86 ± 11.2 years. The age- and sex-standardized prevalence for HBsAg positivity was 9.7%. It was higher in males than in females (OR: 1.28; 95% CI: 0.9-1.7). The risk of infection in singles was significantly higher than in married cases (OR: 2.13). Eight (5.8%) of HBsAg-positive cases were infected with HDV, and 17 (12.3%) were positive for anti-HCV antibody. Conclusion: This study demonstrates that the prevalence of HBsAg seropositivity in Golestan province of Iran is higher than the levels reported by WHO and previous studies from Iran. It is very important, especially for health providers and policy makers, to recognize the risk factors of HBV infection and its co-infection with HDV and HCV in this area and design effective preventive programs

Dvogodišnje serološko istraživanje virusa goveđe virusne dijareje, goveđeg alfa-herpesvirusa 1 i virusa goveđe parainfluence tipa 3 na farmama mliječnih krava u Qazvinu, sjeverozapadni Iran

Infections with bovine viral diarrhea virus (BVDV), bovine alphaherpesvirus 1 (BoHV-1), and bovine parainfluenza virus type 3 (BPIV-3) cause diseases in cattle with serious economic consequences worldwide. The objective of the present study was to determine of herd-level and animal-level BVDV, BoHV-1, and BPIV-3 seroprevalence, and evaluate some of the associated risk factors on farms in Qazvin province, Northwestern Iran. A total of 1036 cattle in 16 herds were randomly selected, and their serum samples were tested to detect antibodies to these viruses in a cross-sectional study over 2 years. The results showed the seroprevalence of BVDV, BoHV-1, and BPIV-3 was 100%, 56.3%, and 100% at herd-level and 55.1%, 5.1%, and 95.2% at animal-level, respectively. Statistical analysis revealed that the farm was a strong risk factor for all the studied viruses, while the year was determined as a risk factor for only BVDV (P<0.001). The seroprevalence of BVDV and BPIV-3 was significantly (P<0.01) affected by season. The proportion of seropositive cows increased with age for BVDV and BoHV-1 (P<0.001). Concurrent infection was the highest in mixed infections with BVDV and BPIV-3 (53.2%), and there was a positive correlation between BVDV and BoHV-1 seropositivity (R2= 0.106, P<0.001). The present study shows that infections of BVDV and BPIV-3 are common in cattle in Northwestern Iran and which implies the need to implement control programs to reduce the risk of the spread of these viruses.Infekcije virusom goveđe virusne dijareje (BVDV), goveđeg alfa-herpesvirusa 1(BoHV-1) i virusa goveđe parainfluenze tipa 3 (BPIV-3) uzrokuju pobol u goveda širom svijeta, sa znatnim ekonomskim posljedicama. Cilj ovog istraživanja bio je odrediti seroprevalenciju BVDV-a, BoHV-1 i BPIV-3, na razini stada i na razini životinje, te procijeniti rizične čimbenike povezane s tim virusima na farmama u pokrajini Qazvin u sjeverozapadnom Iranu. U presječnom istraživanju, koje je trajalo više od dvije godine, nasumično je odabrano ukupno 1036 goveda iz 16 stada čiji su uzorci seruma testirani kako bi se pronašla antitijela na tri navedena virusa. Rezultati su pokazali da je seroprevalencija BVDV-a 100 %, BoHV-1 56,3 %, a BPIV-3 100 % na razini stada, dok je na razini životinje seroprevalencija BVDV-a bila 55,1 %, BoHV-1 5,1 %, a BPIV-3 95,2 %. Statistička je analiza pokazala da je farma znatan rizični čimbenik za sve istraživane viruse, dok se kombinacija godine i sezone pokazala rizičnim faktorom samo za BVDV (P < 0,001). Na seroprevalenciju BVDV-a i BPIV-3 znakovito je utjecala sezona (P < 0,01). Omjer seropozitivnih krava za BVDV i BoHV-1 znakovito je rastao s dobi (P < 0,001). Najčešća je koinfekcija bila virusima BVDV i BPIV-3 (53,2 %), a ustanovljena je i pozitivna korelacija između seropozitivnosti BVDV-a i BoHV-1 (R2 = 0,106, P < 0,001). Ovo je istraživanje pokazalo da su infekcije BVDV-om i BPIV-3 česte u goveda u sjeverozapadnom Iranu što upućuje na potrebu uvođenja programa nadzora kako bi se smanjio rizik od širenja ovih virusa

Transport Properties in Ferromagnetic Josephson Junction between Triplet Superconductors

Charge and spin Josephson currents in a ballistic superconductor-ferromagnet-superconductor junction with spin-triplet pairing symmetry are studied using the quasiclassical Eilenberger equation. The gap vector of superconductors has an arbitrary relative angle with respect to magnetization of the ferromagnetic layer. We clarify the effects of the thickness of ferromagnetic layer and magnitude of the magnetization on the Josephson charge and spin currents. We find that 0-\pi transition can occur except for the case that the exchange field and d-vector are in nearly perpendicular configuration. We also show how spin current flows due to misorientation between the exchange field and d-vector.Comment: 6 pages, 8 figure