6,273 research outputs found
Mohamed Abdel Khalek Allam Oral History
No full textMohamed Abdel Khalek Allam served as Vice President for Student Affairs at the American University in Cairo from the early 1970s until his retirement in 2000, having begun his career at the university in 1966 as Registrar, in these posts acting as a liaison with the Egyptian government. He recalls his boyhood schooling and his graduate studies and life in the United States, as well as his early career in education and work in forming an Egyptian Government’s Youth Ministry in the early 1960s. Allam discusses how he came to he hired at AUC as Registrar, his adjustment to the position for which he had no prior experience, and his relationship with President Thomas Bartlett and Dean of Students Frank Blanning. The run-up to and aftermath of the June 1967 Six-Day is outlined, including efforts to forestall nationalization like his own back-channel dealings with the Egyptian authorities (and the advantage of President Nasser’s daughter Mona attending AUC). Allam gives a detailed account of his involvement in the university reaching a protocol agreement with the Egyptian government in the mid-1970s that recognized AUC’s degrees. He provides a view of his relationships with AUC Presidents in the 1970s and 1980s (Chris Thoron, Cecil Byrd, and Dick Pedersen, along with Board of Trustees Chairman Landon Thorne), and reveals his input on administrative personnel decisions, including the University Counselor position. The 1990s controversy over the retirement age for Egyptian faculty members, and the role of President Donald McDonald, also receive attention. In connection with this position as Vice President for Student Affairs, Allam’s interaction with students, influence on admissions policy, and initiatives like the Student Counseling Center are addressed. He also speaks about his time working for United Nations projects in Sudan in the early 1970s
La solitudine dell'Occidente
No full textIl desiderio e il malessere che legano l'Islam all'Occidente nel racconto di vita di un musulmano in Italia.
Non più scontro o crisi di civiltà, ma incontro delle diversità: è questo il passaggio cruciale di un Occidente che deve fare i conti con le proprie identità multiple e imparare a comprendere la complessità anziché combatterla. Khaled Fouad Allam, da sempre cittadino di due mondi, si pne alla confluenza tra queste identità e dal suo punto di osservazione privilegiato fa spaziare lo sguardo su luoghi ed eventi, sentimenti e umori dei nostri tempi: da Trieste a Qom, da Gerusalemme alle banlieues parigine, dalla rivoluzione iraniana del 1979 alla guerra in Iraq, dall'11 settembre al trionfo di Hamas nelle ultime elezioni palestinesi. La testimonianza diretta del proprio vissuto – l'infanzia in Marocco, i viaggi, il lavoro di giornalista, docente e parlamentare in Italia – si intreccia alla denuncia degli stereotipi e dei luoghi comuni che segnano la nostra comprensione di nodi problematici fondamentali quali la questione femminile; la separazione tra legge civile, morale e religiosa; l'uso ideologico dei concetti di gruppo etnico e comunità. "La questione per i musulmani oggi è come essere musulmani d'Occidente" osserva Fouad Allam, e mostra con il proprio esempio che la nostra cultura può essere rideclinata alla luce di una sensibilità e di un'esperienza provenienti dal mondo musulmano. Per questo riprende e interpreta – con riferimenti culturali eclettici, tra cui lo scrittore nomade per eccellenza Bruce Chatwin, i poeti della classicità araba, la filosofia di Deridda e le armonie di Bach – nozioni cardine del pensiero occidentale quali Europa, civiltà, téchne, progresso, multiculturalismo, integrazione, che oggi più che mai chiedono di essere riformulate. La sua prosa live, elegante e precisa disegna una mappa per la convivenza tra Islam e Occidente invitando l'etica, la politica e la riflessione filosofica di questi mondi a porsi in ascolto e in dialogo reciproco
CO2 Sequestration by Allam Cycle
No full textNatural gas powerplants account for 40% of the electricity generation in the United States[1] and 617 million tons of CO2 emissions a year[2]. The largest powerplants with carbon capture technology utilize a post-combustion absorption technology that must treat a large volume of flue gas and compress CO2 to pipeline specifications from near-ambient pressure. The Allam cycle, patented in 2013 by Rodney Allam, uses oxy-combustion and a supercritical CO2 stream as the working fluid to produce high-purity liquid pipeline CO2. While it was developed commercially at a 50-megawatt thermal (MWt) plant in 2018, the economics for a larger, 300 MW plant had not been documented. This project shows that under the current US tax code, the Allam cycle is less economical than the traditional natural gas combined cycle (NGCC) and NGCC with CDR. However, due to the over 99% capture rate, compared to 90% in post-combustion capture, the breakeven credit to traditional NGCC of 121/tonne. Similarly, for a desired IRR of 15%, the CO2 credit required for the Allam cycle is 188/tonne for the NGCC with CDR. The Allam cycle provides increasingly better financial returns than the NGCC with CDR as the tax credit for sequestration rises. The results of this analysis were produced by first simulating both powerplants in Aspen Plus, and then conducting a discounted cash flow analysis for various scenarios
The hydrogen-fueled Allam Cycle
No full textThe Allam Cycle is one of the most promising concepts in thermal power generation, especially due to its high thermal efficiency (> 60 %) and near zero emissions while being fossil fueled. In view of a global shift towards renewable energies and the imminent scarcity of fossil energy sources, the transition of thermal power generation to hydrogen as fuel becomes increasingly relevant. This raises questions about the performance, design and operational challenges associated with switching to hydrogen.
Although various combinations of working fluids and fuels have been discussed before, a thorough design and a thermodynamic analysis of the H2-fired Allam Cycle has yet to be carried out. This work presents an Aspen HYSYS-based first thermodynamic analysis of the H2-fueled Allam Cycle and compares it with the fossil-fueled cycle. Preventing and compensating the inevitable CO2 release via the condensate becomes the key challenge, for the solution of which three methods are proposed and evaluated. The resulting, newly proposed LSM-model allows a net zero emission H2-Allam Cycle.
Based on the lower heating value (LHV) the thermal efficiency of the H2-Allam Cycle is 5 % higher than for the NG-Allam Cycle. This is primarily due to the higher specific turbine work resulting from the increased specific isobaric heat capacity of the steam-enriched working fluid and secondarily due to the higher LHV of hydrogen.
When accounting for the energy requirements of hydrogen processing and losses via turbine cooling, the thermal efficiency of the new cycle drops significantly but remains competitive with the NG-Allam Cycle.Vo
Creep rupture life analysis of a supercritical CO2 gas turbine for Allam cycle using the IN713C
No full textLAUREA MAGISTRALEIl cambiamento climatico è una realtà poiché la temperatura media globale è aumentata di 0,9 ° C rispetto alla temperatura media globale preindustriale. Per mantenere l'aumento della temperatura media globale al di sotto dei 2 ° C, è necessario passare a fonti energetiche a basse emissioni oa zero emissioni di carbonio. Il gas naturale, un combustibile fossile a basse emissioni, offre un equilibrio alla natura intermittente delle energie rinnovabili nel soddisfare la domanda mondiale di energia. Il ciclo Allam è un nuovo ciclo che utilizza gas naturale e CO2 supercritica come fluido di lavoro, producendo zero carbonio netto o, in altre parole, cattura il 100% del carbonio prodotto. Le turbine a gas basate sul ciclo Allam utilizzano il meglio delle tecnologie delle turbine a vapore e delle turbine a gas, poiché la turbina a gas progettata per funzionare con il ciclo Allam deve essere progettata per CO2 supercritica. Questo studio di ricerca esplora l'uso della superlega IN713C nelle pale e nelle palette della turbina progettata per funzionare con ciclo Allam. L'obiettivo di questo lavoro è trovare la risposta alla rottura per scorrimento delle pale e alette di guida di tutti gli stadi della turbina a gas CO2 supercritica, eseguendo un'analisi fondamentale della rottura per scorrimento utilizzando i parametri della legge di potenza. L'obiettivo principale è verificare se il materiale ben collaudato e più ampiamente disponibile INCONEL 713C può essere utilizzato per pale e palette guida nei sistemi di turbina progettati dopo il nuovo ciclo Allam. Questo lavoro di ricerca rileva che IN713C si mostra promettente per l'uso nelle pale e nelle pale di guida della turbina a gas progettata dopo il ciclo Allam.Climate change is a reality as the global average temperature increased by 0.9 °C when compared with the pre-industrial global average temperature. To keep the increase in global average temperature below 2 °C, it is necessary to move to low emission or net zero carbon energy sources. Natural gas, a low emission fossil fuel offers a balance to the intermittent nature of the renewable energy in meeting the world energy demand. Allam cycle is a novel cycle that uses Natural gas and supercritical CO2 as working fluid, producing net zero carbon or in other words, captures 100% of the carbon produced. Gas turbines based on Allam cycle uses the best of steam turbine and gas turbine technologies, since the gas turbine designed to run on Allam cycle need to be designed for supercritical CO2. This research study explores the use of the superalloy IN713C in the blades and vanes of the turbine that is designed to operate on Allam cycle. The objective of this work is to find the creep rupture response of the blades and guide vanes of all stages of the supercritical CO2 gas turbine, by performing a fundamental creep rupture analysis using the power law parameters. The primary objective is to check whether the well proven and most widely available material INCONEL 713C is viable to be used for blades and guide vanes in the turbine systems designed after the novel Allam Cycle. This research work finds that IN713C shows promise for use in blades and guide vanes of the gas turbine designed after Allam cycle
Coupling chemical looping air separation with the Allam cycle – A thermodynamic analysis
No full textThe Allam cycle is a class of oxy-fuel combustion power cycles using supercritical CO2 (s-CO2) as the thermal fluid to achieve power generation with inherent capture of CO2. Compared to other conventional CO2 capture techniques, the Allam cycle stands out owing to its high fuel-to-electricity conversion efficiency (55–59%), the elimination of the Rankine cycle and reduced physical footprint. A key source of energy penalty of Allam cycle comes from the air separation unit (ASU), which supplies pure oxygen via an energy intensive cryogenic process. This paper presents a thermodynamic analysis of a novel supercritical CO2-based power generation scheme, in which a natural gas fuelled Allam cycle is integrated with a chemical looping air separation (CLAS) system, which supplies oxygen to the combustor. The modelling results show that the Allam-chemical looping air separation (Allam-CLAS) process can achieve 56.04% net electrical efficiency with a 100% CO2 capture rate, when a Co3O4-based oxygen carrier is used. This is 6% higher than the Allam cycle coupled to a cryogenic ASU. The exergetic efficiency of the Allam-CLAS system driven by the Co3O4-CoO redox cycle is 57.13%, also more favourable than a conventional Allam-ASU system (with reported exergetic efficiency of 53.4%). This newly proposed Allam-CLAS power cycle presents a highly efficient, and simple solution to generate zero-carbon electricity from natural gas.Nanyang Technological UniversityThe authors wish to acknowledge financial support by Nanyang Technological University
The Allam Cycle: A Review of Numerical Modeling Approaches
No full textIn recent years supercritical CO2 power plants have seen a growing interest in a wide range of applications (e.g., nuclear, waste heat recovery, solar concentrating plants). The Allam Cycle, also known as the Allam-Fetvedt or NET Power cycle, seems to be one of the most interesting direct-fired sCO2 cycles. It is a semi-closed loop, high-pressure, low-pressure ratio, recuperated, direct-fired with oxy-combustion, trans-critical Brayton cycle. Numerical simulations play a key role in the study of this novel cycle. For this reason, the aim of this review is to offer the reader a wide array of modeling solutions, emphasizing the ones most frequently employed and endeavoring to provide guidance on which choices seem to be deemed most appropriate. Furthermore, the review also focuses on the system’s performance and on the opportunities related to the integration of the Allam cycle with a series of processes, e.g., cold energy storage, LNG regasification, biomass or coal gasification, and ammonia production
Khaled Fouad Allam, L’Islam spiegato ai leghisti
No full textPonendosi alla “frontiera” tra «ciò che stiamo lasciando e l’enigma del domani» Allam, autore tra l’altro di alcuni bestsellers quali L’Islam globale e La solitudine dell’Occidente, attraverso il libro, L’Islam spiegato ai leghisti, propone un nuovo approccio ad una delle più stringenti questioni del XXI secolo: il rapporto tra l’Islam e l’Occidente. A metà tra racconto personale e analisi sociologica il saggio di Allam, sociologo e politico di origine algerina, cittadino italiano dal 1993 do..
Modelling, simulation and control of the Allam cycle
No full textLAUREA MAGISTRALENell’ultimo decennio sono state sviluppate soluzioni ottimistiche per affrontare il problema dell’elevata concentrazione di CO2. Una delle tecnologie più promettenti è il Ciclo Allam. Utilizzando questo processo di ossicombustione è possibile ottenere alta efficienza, semplicità, bassi costi ed emissioni prossime allo zero. Il Dipartimento di Energia del Politecnico di Milano ha studiato questo ciclo negli ultimi sei anni, trovando risultati interessanti in termini di efficienza e prestazioni a carico parziale del ciclo in condizioni statiche, tuttavia non esistono studi relativi alla dinamica e al controllo di questo nuovo processo. Nel presente studio è stata sviluppata la modellazione, simulazione e analisi dinamica del Ciclo Allam, con l’obiettivo di verificare se questo processo può essere completamente controllato utilizzando regolatori tradizionali anche in condizioni off-design. Per la modellazione e simulazione dell’impianto sono state considerate le informazioni fornite dal Dipartimento di Energia del Politecnico di Milano. Dopo la costruzione completa del modello, viene eseguita l’analisi dinamica per definire quali variabili verranno controllate e quali verranno utilizzate come input del sistema. Dopo ulteriori analisi,
i regolatori sono progettati, utilizzando i controller PI in tutto il sistema. Infine,
grazie al sistema di controllo, è stato possibile testare il modello in scenari più realistici, ottenendo una rampa di carico del 4% al minuto, valore competitivo in termini di flessibilità dell’impianto. Allo stesso modo, sono stati analizzati i principali transitori durante questi scenari.During the last decade, optimistic solutions to face off the problem of high concentration of CO2 has been developed. One of the most promising technologies is the so called Allam Cycle. By using this oxy-combustion process, it is possible to obtaing high efficiency, simplicity, low costs and near-zero emissions. The department of Energy of Politecnico di Milano has been studying this cycle during
the last six years, finding interesting results in terms of efficiency and part-load perfomance of the cycle in static conditions, however there are no studies focus on the energy production and on the its flexibility. In the present study, the modelling, simulation and dynamic analysis of the Allam Cycle has been developed, with the
aim to verify whether or not this process can be fully controlled using traditional regulators even in off-design conditions. For the modelling and simulation of the plant, the information given by the Energy department of Politecnico di Milano has been considered. After the full construction of the model, the dynamic analysis was
perform to define which variables will be controlled and which ones will be used as an inputs of the system. After additional analysis, the regulators are designed, using PI controllers in all the system. Finally, thanks to the control system, it has been possible to test the model in more realistic scenarios, getting a load ramp rate of 4% per minute, which is a competitive value in terms of power plant flexibility. Likewise, the main transients during these scenarios have been analysed.Martelli, Emanuel
ALLaM: Large Language Models for Arabic and English
No full textWe present ALLaM: Arabic Large Language Model, a series of large language models to support the ecosystem of Arabic Language Technologies (ALT). ALLaM is carefully trained considering the values of language alignment and knowledge transfer at scale. Our autoregressive decoder-only architecture models demonstrate how second-language acquisition via vocabulary expansion and pretraining on a mixture of Arabic and English text can steer a model towards a new language (Arabic) without any catastrophic forgetting in the original language (English). Furthermore, we highlight the effectiveness of using parallel/translated data to aid the process of knowledge alignment between languages. Finally, we show that extensive alignment with human preferences can significantly enhance the performance of a language model compared to models of a larger scale with lower quality alignment. ALLaM achieves state-of-the-art performance in various Arabic benchmarks, including MMLU Arabic, ACVA, and Arabic Exams. Our aligned models improve both in Arabic and English from their base aligned models
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