thermodynamic study of orc at different working and peripheral conditions

Abstract Power generation from low temperature sources using Organic Rankine Cycle (ORC) was studied in this paper. A thermodynamic model was achieved in Aspen plus environment and the best working conditions were obtained for on-design conditions. Furthermore, off-design analysis is conducted for the cycle in this study. Results depict the effect of peripheral conditions on performance of the cycle. In addition, the effect of some possible working fluid defects on the performance of the cycle is considered at off-design conditions

Parameter estimation and modeling of lithium and lithium-ion batteries

Specific characteristics of Li-ion batteries (LIBs) make them promising candidates for energy storage systems when compared with the others. High working voltage and energy density as well as green technology of LIBs are the reasons for increasing interest to use these electrochemical systems as the substitute of conventional combustion engine of automobiles. Consequently, the interest to study these technologies has increased recently and several models have been introduced to simulate their behavior. However, it is difficult to model all multiphysics phenomena happening inside such rechargeable batteries. Some important choices need to be made when one wants to select an appropriate model for considering the main physics elements and yet be simple enough for large time scale studies. Combining chemical/electrochemical kinetics and transport phenomena, electrochemical models have been introduced to tackle most important principles inside the cell. These models, however, require known electrochemical parameters which most of the time are hard to get experimentally. Parameter estimation (PE) techniques simplify extracting these representative parameters of the cell behaviour. In this study, a PE methodology has been introduced to estimate the most influential electrochemical parameters of LIBs considering different positive electrode materials. The methodology starts with simplifying the well-known pseudo-two-dimensional (P2D) model, the most complex and the most popular electrochemical engineering models for simulating porous electrodes and introducing an enhanced single particle model (SPM). Neglecting the micro-structure of LIB, major electrochemical parameters are detected at the cell level. Next, the best time domains and discharge current rates to estimate each parameter are estimated by virtue of sensitivity analyses. Owing to the fact that the behavior of LIBs depends on the active materials employed in the electrode, the proposed methodology is verified for three different positive electrode active materials including LiCoO2, LiMn2O4 and LiFePO4. Furthermore, focusing on LiFePO4 (LFP), as the most promising positive electrode active material, a new modification is proposed to the model to address special features of this material. In this regard, a simplified electrochemical model is equipped with a variable resistance equation whose coefficients are estimated by means of PE.Résumé : Les batteries au Li-ion (BLI) figurent parmi les technologies les plus prometteuses pour le design de systèmes de stockage d’énergie à cause de leurs caractéristiques intrinsèques. Leur grand voltage de travail, leur grande densité énergétique et leur impact écologique positif expliquent l’intérêt soutenu de l’utilisation des BLI pour remplacer par exemple les moteurs à explosion dans les applications de transport terrestre. Il n’est donc pas surprenant de constater que ces technologies ont eu une attention scientifique importante et que plusieurs auteurs ont développé des modèles numériques simulant leur comportement. Il reste cependant difficile de représenter tous les phénomènes multiphysiques qui se déroulent à l’intérieur des batteries rechargeables par des modèles mathématiques. Des compromis importants doivent être faits lorsqu’on doit choisir un modèle représentant les principaux phénomènes physico-chimiques tout en restant assez simple pour pouvoir l’utiliser dans des études s’échelonnant sur de larges périodes temps. Représentant à la fois la cinétique électrochimique et le transport de masse, les modèles électrochimiques ont été introduits pour prendre en compte les phénomènes les plus importants. Ces modèles demandent cependant de connaître tous les paramètres électrochimiques, des données qui sont difficiles à obtenir expérimentalement. Les techniques d’estimation de paramètres simplifient l’obtention de ces données critiques pour représenter le comportement de la pile. Dans cette étude, une méthode d’estimation de paramètres a été introduite pour estimer les paramètres électrochimiques des BLI les plus influents, en prenant en compte différents matériaux d’électrode positive. La méthode proposée repose sur une amélioration du modèle à particule unique, qui représente lui-même une simplification du modèle pseudo-2D, le modèle électrochimique le plus connu et le plus complexe dans le domaine de la simulation de piles à électrodes poreuses. Les paramètres électrochimiques les plus importants ont été identifiés en négligeant la micro-structure de la batterie au Li-ion. Une étude de sensibilité a ensuite permis d’identifier les domaines temporels et les courants de décharge les plus favorables pour l’identification de chaque paramètre. Étant donné que le comportement des BLI dépend fortement des matériaux actifs utilisés pour la fabrication des électrodes, la méthodologie proposée a été testée sur 3 matériaux actifs différents (LiCoO2, LiMn2O4 and LiFePO4) employés dans la fabrication industrielle d’électrodes positives. Finalement, une autre amélioration du modèle à particule unique a été proposée et testée afin de mieux représenter le comportement spécifique du LiFePO4 (LFP), un matériau actif parmi les plus prometteurs pour l’électrode positive. Plus précisément, un modèle électrochimique simplifié incluant une équation représentant la variation de résistance en fonction du degré de décharge a été développé et les coefficients de cette équation ont été déterminés au moyen de la méthode d’estimation de paramètres proposée

Utjecaj tretmana limunskom kiselinom na svojstva iverice proizvedene od grana vrtnog drveća pomiješanih s ostatkom od prerade šećerne trske i palminim lišćem

The aim of this research was to determine the effect of citric acid treatment on the particleboard properties obtained by mixing three types of lignocellulosic sources. The board was produced by mixing garden tree branches, bagasse and palm leaves in different mass portions (90:5:5, 70:15:15, 50:25:25). Urea-formaldehyde (UF) resin was used at two levels as 10 % surface layer and 8 % middle layer, and 8 % surface layer and 6 % middle layer based on the raw materials. Citric acid was used at three levels of 0, 10, and 20 % by weight. The physical and mechanical properties of particleboards are measured according to the European Standard EN. Fourier transform infrared spectroscopy was used to distinguish the effect of citric acid treatment on the particles. The results showed that, when the amount of citric acid increased, the water absorption of panels decreased, and the mechanical properties improved. As garden tree branch content in the particleboard increased, so did the total resistance. According to the results of this study, the particleboards containing 70 % garden tree branches, 0 % citric acid, and 8 % UF resin, as well as those of 50 % garden tree branches, 0 % citric acid, and 10 % UF resin can be used for type P1 boards (bending strength of 10 MPa and 0.24 MPa internal bonding). In comparison, the boards containing 90 % garden tree branches, 10 % citric acid and 10 % UF resin were proposed for type P2 boards (bending strength of 11 MPa, modulus of elasticity of 1600 MPa and internal bonding of 0.35 MPa).Cilj ovog istraživanja bio je utvrditi utjecaj tretmana limunskom kiselinom na svojstva iverice proizvedene miješanjem triju vrsta lignoceluloznog materijala. Ploča je proizvedena miješanjem grana vrtnog drveća, ostataka od prerade šećerne trske i palmina lišća u različitim masenim udjelima (90 : 5 : 5; 70 : 15 : 15; 50 : 25 : 25). Urea-formaldehidna (UF) smola dodavana je u različitim udjelima s obzirom na lignoceluloznu sirovinu: 10 % u površinski sloj i 8 % u srednji sloj te 8 % u površinski sloj i 6 % u srednji sloj. Primijenjena su tri težinska udjela limunske kiseline: 0, 10 i 20 %. Fizička i mehanička svojstva ploča iverica mjerena su na temelju europskog standarda. Za određivanje utjecaja tretmana limunskom kiselinom na čestice lignoceluloznog materijala primijenjena je Fourierova infracrvena spektroskopija. Rezultati su pokazali da se s povećanjem količine limunske kiseline smanjilo upijanje vode ploča i da su se poboljšala njezina mehanička svojstva. Kako se udio grana vrtnog drveća u iverici povećavao, tako se povećavala i ukupna otpornost ploče. Kao ploče tipa P1 (čvrstoća na savijanje od 10 MPa i čvrstoća na raslojavanje od 0,24 MPa) mogu se upotrebljavati iverice koje sadržavaju 70 % grana vrtnog drveća, 0 % limunske kiseline i 8 % UF smole te iverice koje imaju 50 % grana vrtnog drveća, 0 % limunske kiseline i 10 % UF smole. Za usporedbu, ploče koje sadržavaju 90 % grana vrtnog drveća, 10 % limunske kiseline i 10 % UF smole predlažu se kao ploče tipa P2 (čvrstoća na savijanje 11 MPa, modul elastičnosti 1600 MPa i čvrstoća na raslojavanje 0,35 MPa)

Discourse Formulation of the Modern Woman Subject in the Discourses of Constitutional Era

Amidst Iran's confrontation with Western modernity and the subsequent discursive conflicts, women's lives, identities, and living conditions came to the forefront as prominent topics of discourse. This resulted in an extensive array of discussions concerning them, thereby transforming women into a subject of tension. This article analyzes the discourses that emerged concerning women in the writings of the Constitutional era. It employs critical discourse analysis to investigate how the modern woman subject was formulated in the most prominent discourses of this era. The objective of this study is to comprehend the ideologies that govern each discourse of the Constitutional era as they pertain to the modern woman subject. Additionally, the position and status of each discourse within the hegemonic discourse are examined. The results suggest that the progressive discourse presents the modern woman as a demanding and critical subject, having been formed in opposition to tradition. Conversely, the traditional discourse depicts her as a liberated and European-like figure. In the midst of these semantic disputes, the integrative discourse constructs the subject of a woman who is acknowledged as a conscientious, Sharia-compliant, and duty-oriented individual. The integrative discourse's construction of meaning, which avoided explicit conflict with religious traditions, attained a more advantageous position and has maintained its existence throughout subsequent eras

The Social Construction of Financial Accountability in Government and Parliament Discourses

Differences in the perceptions of various social groups, including parliamentarians, government officials, and elites from financial accountability, raise the question of what the meaning of financial accountability is or how it is understood. So, with a post-structuralist approach, we considered financial accountability as a social construct, and we get a better understanding of it from Norman Fairclough's theoretical knowledge of text analysis, and Laclau and Mouffe in the context of political discourse analysis. We analyzed the parliament's detailed negotiations on the adoption of the budget of the entire country in the deliberations of the government and the parliament and classified the research findings in the six political, economic and social paradigms of Iran after the revolution. The findings of the research, summarized briefly in this article, indicate the influence of power relations and the use of hegemonic elements in the discourse system formed in the discourses of the government and the parliament. Thus, in each paradigm, dominant discourses formed with context, and by highlighting themselves and marginalizing rival discourse, they succeeded in securing a temporary centralized sign and a new articulation of the semantic system of financial accountability

Decarbonization for the energy transition and green production

A considerable part of the fossil CO2 emissions comes from the energy sector, in which the main parts are released through energy-intensive industries, namely metal production, chemicals, and manufacturing. Hence, decarbonization of industries is considerably important beside the other sectors such as net zero buildings and transformation. The main concept of this speech will cover renewable energy/resources solutions after looking into potential classic decarbonization. First objective is about the upgrading of the existing processes, equipment, and plants besides implementing the heat recovery/integration based on the innovations toward reducing the energy requirements and efficiency increments. Then, the renewable resources are going to be introduced. Moreover, energy production and conversion methods, feedstocks, carbon capture and storage, and electrification will be discussed. Overall, both classic and innovative renewable attempts are required to reach the deep decarbonization targets. At the end, the objectives are going to be expanded toward chemical industries by introducing the potential technology implementation at different subsectors. For this purpose, the assessed roadmaps and pathways will be discussed further. The primary research results of my current study reveal that although all of the inventive suggestions are not available at an industrial scale or are not economically viable yet, they will play a crucial role in the energy transition at upcoming decades. Dr. Talieh Rajabloo GSM +32(0)465437542 [email protected], [email protected]; [email protected] www.uhasselt.be/imo

The effect of education based on Leventhal's model on adherence to treatment and control of blood pressure in patients with hypertension

Background &amp; Aim: Hypertension is a prevalent and significant health problem; moreover, lack of treatment adherence can cause precarious complications. The present study aims to determine the effect of education based on Leventhal's model on adherence to treatment and control of blood pressure in patients with hypertension.&#x0D; Methods &amp; Materials: This quasi-experimental study was performed on 59 patients with hypertension in Gonabad in 2020. The participants were selected based on convenience sampling; they were randomly assigned to the intervention and control groups. In addition to the routine treatment for hypertension, the patients in the intervention group received a training program based on Leventhal's model in 45-minute sessions and three times a week. In contrast, the patients in the control group received only the routine treatment for hypertension. A demographic and Hill-Bone Adherence Questionnaires were completed for the participants. Moreover, their blood pressure was recorded using the blood pressure record form. The data were analyzed in SPSS v.22 software, at the significance level of p&lt;0.05.&#x0D; Results: The two groups were homogeneous in adherence to treatment (P=0.63) before the intervention; yet, there was a substantial difference between the groups once the intervention was implemented (P&lt;0.001). Besides, the average systolic and diastolic blood pressure was not significantly different between the two groups before the intervention. After the intervention, though, the difference was reported significant (p&lt;0.05).&#x0D; Conclusion: Education based on Leventhal's model caused an improvement in adherence to treatment and reduced blood pressure among patients with hypertension.</jats:p

Potential of petro-chemical sectors for industrial decarbonization_Part I

Facing energy transition and carbon mitigation is the subject of different sectors from energy production and industries to transportation and building constructions. This study focuses on industrial decarbonization and investigates carbon dioxide (CO2) emissions from different petro-/chemical plants. For this research project, the emission rate and CO2 stream purity of various petro-/chemical sub-sectors were listed to find the low-hanging fruit options for decarbonization. Then, the processes are categorized and described, deriving the most important parameters from different literature to generate an essential dataset for each product. This paper includes the main achievements over ethylene-oxide and ammonia production and investigates the CO2 emission sources at the related processes, it also introduces novel decarbonization approaches.EPOC projec