185 research outputs found
Co-Combustion of High and Low Ash Lignites With Raw and Torrefied Biomass Under Air and Oxy-Fuel Combustion Atmospheres
No full textBarzegar, Ramin/0000-0003-2796-7126;Co-combustion characteristics of high and low ash lignites blended with raw and torrefied pine woodchips were studied by Thermogravimetric Analyzer (TGA) under air and oxy-fuel conditions. The lignites were blended with biomass samples at the mass fraction of 50/50 wt.%. Three heating rates of 10, 20, and 40 degrees C/min were chosen, and the characteristic temperatures, including initial, ignition, and burnout temperatures, were obtained. In order to estimate the activation energies of the co-combustion of the blends, Flynn-Wall-Ozawa, Kissinger-Akahira-Sunose, and Friedman kinetic methods were employed. Additionally, to assess the summative behavior of the fuel blends, the relative error as a degree of synergism was calculated based on the difference between theoretical and experimental DTG profiles. It was seen that co-combustion of torrefied biomass with the low ash Orhaneli lignite in air resulted in the average relative error of 21.41%, indicating the maximum synergism for the blend. This value was 9.59% under oxy-fuel combustion atmosphere. Blending torrefied biomass with the high ash Soma lignite resulted in average relative errors of 1.34% and 1.45% under air and oxy-fuel combustion atmospheres showing an insignificant synergetic effect. An improvement in combustion performance was noticed under oxy-fuel combustion conditions. The average activation energy values for the blend of torrefied biomass and Orhaneli lignite were 54.47 and 112.48 kJ/mol under air and oxy-fuel combustion atmospheres, which were lower than that of the parent fuels indicating higher reactivity of the blends. This trend was not seen for Soma lignite. The associated uncertainty values for the FWO method were in the range of 3.57% to 12.45% making it a proper tool for obtaining the kinetic parameters.Turkiye Bilimsel ve Teknolojik Arastirma Kurumu [213M525]This work was supported by the Turkiye Bilimsel ve Teknolojik Arastirma Kurumu [213M525]
The God Without Trust: A Lived Experience of Doubt, a Conditioned Brain, and the Possibility of Reclaiming a Conscious Relationship with the Transcendent
No full textThis article examines a deeply personal experience of doubt toward God—rooted not in denial, but in the inner struggle with conditioned neural patterns, upbringing, and cultural-religious conditioning. The author distinguishes consciousness from mere brain activity, and argues that sincere doubt can serve as a gateway to a more authentic relationship with the divine. God is understood not as an adjudicating or rewarding entity, but as a presence free from judgment and independent of belief. Remaining faithful to the inner experience, the article engages with neuroscience and spiritual psychology to propose a redefinition of the human-divine relationship within individual and collective psychological contexts. "Scientific name: Ramin Bidari. Legal name: Ramin Bidarsefidi.
Donna Vis e i suoi tre mariti. Semantica del desiderio femminile nel Vis o Ramin di Gorgani
No full textThe author focuses on the analysis of the characters, especially the female characters, and their mutual complex relations, in the first verse romance of the New Persian literature, Vis and Ramin of Gorgani (XI sec.) set at the Marv court in the pre-Islamic era. Subsequently the author examines the dynamics of adultery, highlighting how Gorgani will focus on the role of the “demonic”, within the love triangle, as a factor of disorder but also of dynamization of private and public life. Finally, the author analyzes the attitude marked by open philoginy of Gorgani and his legitimation strategies of Vis’s sin
Hannah Arendt: The illegitimacy of violence
No full textThis book presents an original understanding of Hannah Arendt in the context of comparative political theory. The author discusses Arendt’s acute and perceptive view of violence as well as practical applications of her thought in a comparative context. The book examines Hannah Arendt’s ideas about politics and violence provoked by the horrors of totalitarianism. It applies the rich potential of Arendt’s insights to the wider cultural context and discourse of nonviolence. Through case studies of India and Iran, it presents a new way of reading Arendt’s understanding and critique of violence beyond the simple analysis of her work on power and violence. An original, nuanced and meaningful guide to Hannah Arendt, the book will be essential reading for students and scholars in politics, philosophy and peace and conflict studies. © 2025 Ramin Jahanbegloo
Linyit ve torifiye edilmiş biyokütlenin oksi-yanma koşularında yakılmasının termogravimetrik analiz cihazında ve dolaşımlı akışkan yatak yakma sisteminde incelenmesi.
No full textIn this study, the combustion of Turkish lignites (Orhaneli and Soma), torrefied woodchip, and their blends was studied under oxygen-enriched and oxy-fuel combustion conditions in a thermogravimetric analyzer. The iso-conversional kinetic methods were used to estimate the Arrhenius parameters and the uncertainty assessments associated with the kinetic calculations were considered. The co-combustion experiments showed a synergetic effect between the biomass samples and Orhaneli lignite. Based on the obtained results, Orhaneli lignite and the biomass torrefied at 300°C-30 min torrefaction conditions were selected for further analysis in a laboratory scale Circulating Fluidized Bed Combustor (CFBC). The CFBC experiments were conducted under oxygen-enriched and oxy-fuel combustion conditions and included the addition of calcium-based sorbents (Çan limestone and Eskişehir dolomite) for in-situ adsorption of sulfur dioxide emission. The conducted CFBC experiments showed that the sulfur dioxide removal was more effective with the addition of Çan limestone with the particle size of 1-2 mm and Ca/S ratio of 2. Also, increasing the oxygen concentration was an effective solution in sulfur retention. Furthermore, the combustion process in the CFBC was numerically simulated and the results were compared with the experiments. The simulation results showed a good agreement with the experimental data in estimation of the combustor temperature and carbon-based efficiency.Thesis (Ph.D.) -- Graduate School of Natural and Applied Sciences. Mechanical Engineering
Linyit ve torifiye edilmiş biyokütlenin oksi-yanma koşularında yakılmasının termogravimetrik analiz cihazında ve dolaşımlı akışkan yatak yakma sisteminde incelenmesi.
No full textIn this study, the combustion of Turkish lignites (Orhaneli and Soma), torrefied woodchip, and their blends was studied under oxygen-enriched and oxy-fuel combustion conditions in a thermogravimetric analyzer. The iso-conversional kinetic methods were used to estimate the Arrhenius parameters and the uncertainty assessments associated with the kinetic calculations were considered. The co-combustion experiments showed a synergetic effect between the biomass samples and Orhaneli lignite. Based on the obtained results, Orhaneli lignite and the biomass torrefied at 300°C-30 min torrefaction conditions were selected for further analysis in a laboratory scale Circulating Fluidized Bed Combustor (CFBC). The CFBC experiments were conducted under oxygen-enriched and oxy-fuel combustion conditions and included the addition of calcium-based sorbents (Çan limestone and Eskişehir dolomite) for in-situ adsorption of sulfur dioxide emission. The conducted CFBC experiments showed that the sulfur dioxide removal was more effective with the addition of Çan limestone with the particle size of 1-2 mm and Ca/S ratio of 2. Also, increasing the oxygen concentration was an effective solution in sulfur retention. Furthermore, the combustion process in the CFBC was numerically simulated and the results were compared with the experiments. The simulation results showed a good agreement with the experimental data in estimation of the combustor temperature and carbon-based efficiency
Essays on Education, Personality and the Labor Market
No full textHow do different dimensions of personality predict school vs. labor-market performance? How has the value of these traits changed over time? In Essay I, we (my co-author and I) answer these questions using data that includes multidimensional personality and cognitive test scores from mandatory military conscription for 80% of Finnish men. We document that some dimensions of noncognitive skills are productive at school, and some dimensions are counterproductive at school but still valued in the labor market. Action-oriented traits predict low school performance but high labor market performance. School-oriented traits, such as dutifulness, deliberation, and achievement striving, predict high school performance but are not independently valued in the labor market after controlling for school achievement. We further document that the labor-market premium to action-oriented personality traits has rapidly increased over the past two decades.
Labor markets are in constant change. Which personality traits and skills help workers to deal with a changing environment? In Essay II, we document how responses to labor-market shocks vary by individuals' psychological traits. We construct measures of cognitive ability, extraversion, and conscientiousness using the same military data as in Essay I. We analyze establishment closures and mass layoffs between 1995-2010 and document heterogeneous responses to the shock. Extraversion is the strongest predictor of adaptation: the negative effect of a mass layoff on earnings is about 20% smaller for those with one standard deviation higher scores of extraversion. Conscientiousness appears to have no differential impact conditional on other traits. Cognitive ability and education predict a significantly smaller initial drop in earnings, but have no long term advantage. Our findings appear to be driven directly by smaller dis-employment effects: extraverted and high cognitive-ability individuals find re-employment faster in a similar occupation and industry they worked in before.
Finland's success in international student comparisons is often attributed to the quality of its teachers. In Essay III, I examine the teacher selection process in Finland and highlight three new findings. First I show that teacher graduates have lower standardized test performance in comparison to other university graduates. However, in contrast to findings from other developed countries, they have been closing that gap during the last 40 years. Second, past test performance is a poor predictor of teacher aptitude, as measured by expert evaluators during entrance interviews for teacher training programs. This implies that the performance gap between teaching and other programs is not due to lack in applicant quality, but due to uncorrelated factors that influence the aptitude test performance in teaching. In other words, teacher training programs in Finland are not looking to enroll the academically best students. Third, relative to other university graduates, teachers have high wages but low earnings, which helps to explain the popularity of teacher training programs
The Paradox of Zero Tolerance: When the Tool Misses the Target
No full textThe Paradox of Zero Tolerance: When the Tool Misses the Target examines the systemic and psychological impacts of "Zero Tolerance" policies in the post-#MeToo era. While acknowledging that these movements arose from a genuine historical need to address deep-seated injustices against the vulnerable, the article argues that the current implementation of Zero Tolerance has failed to reduce real harassment. Instead, it has led to the "sanitization" of healthy social dialogue and the erosion of communal trust.
Through a multidisciplinary lens, the author explores how evolutionary negativity bias, our ancestral drive to prioritize threat detection over progress, distorts modern policymaking. The article further utilizes the biological principle of Hormesis to argue that complete protection from all stressors (Safetyism) can hinder human resilience, creating "greenhouse environments" where individuals lose the capacity to manage conflict. By analyzing Concept Creep, the text illustrates how the expanding definitions of "violence" may lead to an endless retreat from natural human interaction.
The author concludes by proposing "Smart Regulation" based on four distinct criteria: power asymmetry, intentionality, possibility of escape, and growth potential. The article calls for a shift from "Safe Spaces" to "Brave Spaces", where real, purposeful abuse is decisively halted, but the essential human capacities for empathy, dialogue, and "healed femurs", the true signs of civilization, are preserved.
Note on Language and Translation: The original version of this article was written in Persian by Ramin Saadat and subsequently translated into English by the author to bridge cultural and academic perspectives on the shared human challenge of social justice and resilience
Probing the nature of AFEX-pretreated corn stover derived decomposition products that inhibit cellulase activity
No full textSequential fractionation of AFEX-pretreated corn stover extracts was carried out using ultra-centrifugation, ultra-filtration, and solid phase extraction to isolate various classes of pretreatment products to evaluate their inhibitory effect on cellulases. Ultra-centrifugation removed dark brown precipitates that caused no appreciable enzyme inhibition. Ultra-filtration of ultra-centrifuged AFEX-pretreated corn stover extractives using a 10 kDa molecular weight cutoff (MWCO) membrane removed additional high molecular weight components that accounted for 24–28% of the total observed enzyme inhibition while a 3 kDa MWCO membrane removed 60–65%, suggesting significant inhibition is caused by oligomeric materials. Solid phase extraction (SPE) of AFEX-pretreated corn stover extractives after ultra-centrifugation removed 34–43% of the inhibition; ultra-filtration with a 5 kDa membrane removed 44–56% of the inhibition and when this ultra-filtrate was subjected to SPE a total of 69–70% of the inhibition were removed. Mass spectrometry found several phenolic compounds among the hydrophobic inhibition removed by SPE adsorption.Published version: Humpula, James F., Uppugundla, Nirmal, Vismeh, Ramin, Sousa, Leonardo, Chundawat, Shishir P. S., Jones, A. Daniel, Balan, Venkatesh, Dale, Bruce E. & Cheh, Albert M. (2014). Probing the nature of AFEX-retreated corn stover derived decomposition products that inhibit cellulase activity. Bioresource Technology 152, 38-45. http://dx.doi.org/10.1016/j.biortech.2013.10.08
Profiling of Soluble Neutral Oligosaccharides from Treated Biomass using Solid Phase Extraction and Liquid Chromatography-Multiplexed Collision Induced Dissociation-Mass Spectrometry
No full textThermochemical pretreatment of cellulosic biomass improves cell wall enzymatic digestibility, while simultaneously releasing substantial amounts of soluble oligosaccharides. Profiling of oligosaccharides released during pretreatment yield information essential for choosing glycosyl hydrolases necessary for cost-effective conversion of cellulosic biomass to desired biofuel/biochemical end-products. In this report we present a methodology for profiling of soluble neutral oligosaccharides released from ammonia fiber expansion (AFEXTM)-pretreated corn stover. Our methodology employs solid phase extraction (SPE) enrichment of oligosaccharides based on porous graphitized carbon (PGC), followed by high performance liquid chromatography (HPLC) separation using a polymeric amine based column (Prevail Carbohydrate ES) and electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS) in both positive and negative modes. For structural elucidation on the chromatographic time scale, nonselective multiplexed collision-induced dissociation was performed for quasi-simultaneous acquisition of accurate molecular and fragment masses of neutral oligosaccharids in a single analysis. These analyses directly revealed presence of glucans up to degree of polymerization (DP) 22 without side-chain modifications. Additionally, arabinoxylans with DP up to 6 were detected in the pretreated biomass samples (post-enzymatic digestion). All linkages between sugar units in glucans and arabinoxylans were identified to be p-1-4 linkages based on cross-ring fragment masses. Comprehensive profiling of soluble oligosaccharides also demonstrated that arabinoxylan acetylation was reduced by greater than 85% post-AFEXTM treatment.Published version: Vismeh, Ramin, Humpula, James F., Chundawat, Shishir P. S., Balan, Venkatesh, Dale, Bruce E. & Jones, A. Daniel. (2013). Profiling of Soluble Neutral Oligosaccharides from Treated Biomass using Solid Phase Extraction and LC-TOF MS. Carbohydrate Polymers 94(2), 791-799. http://dx.doi.org/10.1016/j.carbpol.2013.02.00
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