EXERGETIC ANALYSIS OF AN INTERNAL COMBUSTION ENGINE RUNNING ON E22 AND E100

The internal combustion engine performance enhancement is a widely explored subject. Additionally, to pollutant emissions attention, reducing fuel consumption and consequently the greenhouse gas emissions is one of the leading research and development drivers for the future of the engines industry. As the technologies to increase global engine efficiency are becoming less promising (already reaching improvement limits), the next round would be developing technologies capable of recovering the energy rejected to the environment, especially by cooling and exhaust systems. The internal combustion engine efficiency is mainly assessed by its global efficiency, which consists of an energy balance. The exergy analysis enhances the classic energy analysis from the concept of maximum possible work, including the rejected energy, consisting of a handy tool for the feasibility study of energy recovery systems. This article presents and contrasts the energy and the exergy analyses of a flex-fuel internal combustion engine running on its top global efficiency condition. The boundary fuels are hydrous ethanol (E100) and gasoline blend (E22), available fuels in Brazil. The hydrous ethanol fuel properties (octane number, air-fuel ratio, and vaporization enthalpy) theoretically result in higher energetic engine efficiency than E22 in the same engine hardware, with a fixed compression ratio. Preliminary results of this study point 4,5% higher global engine efficiency running on E100 compared to E22. The higher engine energy efficiency running on E100 than E22 does not happen in the Second Law analysis. The classic exergetic efficiency, based on engine brake power, is similar for E22 and E100. The maximum exergetic efficiency, based on destroyed exergy, is 4,1% higher for E22 compared to E100. The estimation and comparison of the exergy rejected to the cooling and the exhaust systems according to the boundary fuel (about 21 kW on average in this case), is fundamental to assess the potential and the availability of any recovery system eventually implemented in the internal combustion engine

Assessing the Role of Water Users Associations in Operating and Maintaining the Improved Irrigation System in Egypt

The current study investigated the influence of Water Users Associations (WUAs) in the operation and the maintenance of the facilities of improved areas in Egypt. With the establishment of irrigation improvement projects, it was planned that WUAs would play an important role in improving water management and ensuring the sustainability of the improved system through enhancing the cooperation between farmers, scheduling the irrigation and maintaining the improved Mesqas (distributaries). The current study aims to check the actual situation after the implementation of irrigation improvement projects through collecting data from samples according to design questionnaires in the improved areas, and analyzing the collected data to investigate the influence of these associations. The results showed that the influence of WUAs in Egypt was still very limited. Irrigation practices were close to the old trend, which was targeting by irrigation improvement projects. The improved system was operated based on the natural relationships between farmers, with no predefined irrigation schedule targeting improving water management. The operator was the main person, and his role was just to arrange the irrigation based on the reservation of the farmers. Old lifting points were still used in the new system. This gave the farmers the chance to work individually, which could decrease the direct conflicts between them, but it had negative impact on water use efficiency. The maintenance of the system was poor, and the target was just to make the system work without considering the sustainability of the system. The study discussed the reasons behind the weak influence of WUAs including the characteristics of such organizations and different factors that affect their performance. In addition, the study suggested the required steps to improve the capacities of these organizations and to enhance the coordination between farmers including the precise distribution of water supply, and the support from the government

N-terminal prohormone brain natriuretic peptide (NT-proBNP) as a noninvasive marker for restrictive syndromes

Constrictive pericarditis (CP) and restrictive cardiomyopathy share many similarities in both their clinical and hemodynamic characteristics and N-terminal prohormone brain natriuretic peptide (NT-proBNP) is a sensitive marker of cardiac diastolic dysfunction. The objectives of the present study were to determine whether serum NT-proBNP was high in patients with endomyocardial fibrosis (EMF) and CP, and to investigate how this relates to diastolic dysfunction. Thirty-three patients were divided into two groups: CP (16 patients) and EMF (17 patients). The control group consisted of 30 healthy individuals. Patients were evaluated by bidimensional echocardiography, with restriction syndrome evaluated by pulsed Doppler of the mitral flow and serum NT-proBNP measured by immunoassay and detected by electrochemiluminescence. Spearman correlation coefficient was used to analyze the association between log NT-proBNP and echocardiographic parameters. Log NT-proBNP was significantly higher (P < 0.05) in CP patients (log mean: 2.67 pg/mL; 95%CI: 2.43-2.92 log pg/mL) and in EMF patients (log mean: 2.91 pg/mL; 95%CI: 2.70-3.12 log pg/mL) compared with the control group (log mean: 1.45; 95%CI: 1.32-1.60 log pg/mL). There were no statistical differences between EMF and CP patients (P = 0.689) in terms of NT-proBNP. The NT-proBNP log tended to correlate with peak velocity of the E wave (r = 0.439; P = 0.060, but not with A wave (r = -0.399; P = 0.112). Serum NT-proBNP concentration can be used as a marker to detect the presence of diastolic dysfunction in patients with restrictive syndrome; however, serum NT-proBNP levels cannot be used to differentiate restrictive cardiomyopathy from CP

Amenability of heap leaching technology on uranium extraction from Gattar and El Missikat area, Eastern Desert, Egypt: A kinetic approach

Studies of uranium heap leaching from different uranium mineralization situated in Eastern Desert of Egypt was investigated via batch experiments, followed by its optimum condition applicationon column percolationtests.The optimum process operating parameters were implemented on large column scale in order to make more condition control and evaluate the time and reagents needed in the large scale. The results show thatleaching efficiency of GIIattained about 78.3% with 34kg/ton acid consumption in a 44 days period, while leaching efficiency of El-Missikat attained about 86.6% with 28kg/ton acid consumption in a 40 days period.Kinetics reaction models of column tests have been investigated to optimize the column leaching behavior. Based on the leaching results of two mineralized samples, the rate of the uranium metal dissolution is controlled by the chemical reaction and the diffusion reaction but diffusion reaction control was more predominate than a chemical reaction control

Predictors of Long Covid 19 Syndrome

Background: Symptoms of covid persist in most cases with development of a multisystem syndrome called long covid syndrome.Objective: The aim of the work was to evaluate symptoms that persist after the acute stage of the disease in a cohort of patients with confirmed or suspected COVID 19 and to define the predictors for long COVID syndrome.Patients and method: This retrospective study involved 164 patients with previously confirmed or highly suspected COVID 19 and still attending to the post covid outpatient clinic in El-Minia University Chest Hospital complaining from persistence of symptoms or for regular follow up. Their data was obtained from their previous medical reports. Results: Post Covid 19 symptoms were found in about 86 % of the studied patients with 42.7% reported neuropsychiatric symptoms and 26.8% reported respiratory symptoms. The most common reported symptoms in nonsevere cases were the anxiety disorders (18.9%), followed by chronic fatigue and neuropathy (15.2%), while chronic dyspnea in 9.8% mostly in severe cases, while vertigo and headache in 9.1%, musculoskeletal symptoms in 6.1% and skin lesions in 3.7%.Conclusion: It could be concluded that persistence of symptoms is very common after acute Covid 19 infection. Chronic dyspnea was reported more frequently in severe cases while anxiety reported mostly by patients with mild disease

Phosphonated Polyetheramine-Coated Superparamagnetic Iron Oxide Nanoparticles for Inhibition of Oilfield Scale

Oilfield scale is one of the significant problems in hydrocarbon production in the oil and gas industry. Many research groups have attempted to develop greener chemicals to meet environmental regulations. Magnetic nanoparticles are an intriguing technology due to their multiple properties, such as size effects, surface-to-volume ratio, magnetic separation, specificity, low toxicity, and the ability to control exposure and surface chemistry. In this project, we propose a new method to remove chemicals from the produced fluids by attaching the chemicals to superparamagnetic iron oxide nanoparticles (SPIONs), allowing a facile magnetic removal and reusing and recycling. In principle, the system is fully self-contained, and no chemicals or SPIONs are discharged, reducing the overall environmental footprint. We earlier reported synthesizing and using phosphonated polyetheramines (PPEAs) as environmentally friendly and potent scale inhibitors against carbonate and sulfate oilfield scales. Herein, we report the synthesis of superparamagnetic iron oxide nanoparticles (SPIONs) functionalized with biocompatible trisodium citrate (TSC) as a stabilizer agent to avoid crystal grain growth SPIONs using a coprecipitation approach. The resultant SPIONs-TSC was further functionalized with a partially linear phosphonated polyetheramine (PPEA), as green SI, via electrostatic interaction, affording highly monodisperse SPIONs-TSC-PPEA. The synthesized SPIONs-TSC-PPEA was thoroughly characterized via various spectroscopic and analytical techniques. Moreover, to validate the proof of concept of inhibition, recovering, and recycling SPIONs-based scale inhibitors, a series of static jar tests and high-pressure dynamic tube-blocking tests at 80 bar and 100 °C under oilfield conditions were conducted. The results showed that SPIONs-TSC-PPEA gave excellent inhibition performance against the gypsum scale even when recycled four times. In addition, the morphology of the gypsum scales in the absence and presence of SPIONs-TSC-PPEA was determined using scanning electron microscopy (SEM).Financial support from the Research Council of Norway for Green Production Chemistry-Based Nanotechnology through the project PETROMAKS 2 program/research project no. 300754. We thank the Research Council of Norway (RCN), and the University of Stavanger for the financial support for A.H.K. under the RCN Ph.D. fellowship grant (fellowship no. 300754-02)

Regiospecific Photochemical Synthesis of Methylchrysenes

Methylated polycyclic aromatic hydrocarbons (PAHs) are suspected to be some of the toxic compounds in crude oil towards marine life and are needed as single compounds for environmental studies. 1-, 3- and 6-methylchrysene (3a,b,c) were prepared as single isomers by photochemical cyclization of the corresponding stilbenoids in the Mallory reaction using stoichiometric amounts of iodine in 82-88% yield. 2-methylchrysene (3d) was prepared by photochemical cyclization where the regioselectivity was controlled by elimination of an ortho-methoxy group under acidic oxygen free conditions in 72% yield. These conditions failed to form 4-methylchrysene from the corresponding stilbenoid. All stilbenoids were made from a common naphthyl Wittig salt and suitably substituted benzaldehydes. We have also demonstrated that methylchrysenes can be oxidized to the corresponding chrysenecarboxylic acids by KMnO4 in modest yields.publishedVersio