42 research outputs found

    A multiscale methodology for the preliminary screening of alternative process designs from a sustainability viewpoint adopting molecular and process simulation along with data envelopment analysis

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    La ricerca scientifica nell\u2019ambito dell\u2019ingegneria chimica si \ue8 focalizzata sia sul perfezionamento delle teorie e delle tecniche utilizzate attualmente, che sullo sviluppo di nuovi strumenti atti a risolvere le problematiche ancora insolute relative alle produzioni di beni e servizi tipici delle industrie chimiche, biochimiche e farmaceutiche. In questo panorama, gli approcci multiscala si sono rivelati molto utili grazie alla loro peculiarit\ue0 di coniugare aspetti che spaziano dalla quanto-meccanica tipica della nanoscala, alla meccanica classica dei materiali massivi, comprendendo prospettive molto ampie e adattando ogni teoria alle diverse applicazioni. Inoltre, il riconoscimento dei concetti legati alla sostenibilit\ue0 come principi cardine per ottenere uno sviluppo sostenibile ha generato un prolifico incremento della diffusione di metodologie per considerare aspetti sociali e ambientali, a fianco delle tradizionali stime economiche, nel quadro pi\uf9 ampio delle valutazioni degli impianti chimici. Di conseguenza, questa tesi tratta dello sviluppo di una metodologia multiscala per la stima preliminare di diverse configurazioni impiantistiche, promuovendo l\u2019adozione di strumenti computazionali differenti e comprendendo valutazioni di carattere economico, sociale e ambientale. Il fine ultimo che tale metodologia si prefigge risiede nella soddisfazione della necessit\ue0 tipica di qualsiasi impianto di produzione, ovvero nella definizione di una metodologia di valutazione di vari parametri e configurazioni impiantistiche, utilizzando un\u2019ottica sostenibile e fornendo risultati velocemente. Al lettore verranno fornite le adeguate informazioni sull\u2019argomento in maniera progressiva attraverso i capitoli di questa tesi. Nel Chapter I saranno descritti il concetto di sostenibilit\ue0 e di sviluppo sostenibile. Seguir\ue0 una trattazione riguardante la loro applicazione nella societ\ue0 odierna da diverse prospettive: a partire da quella pi\uf9 generalista delle istituzioni, fino a quella pi\uf9 particolare dell\u2019industria, per concludere con una parte specifica sull\u2019industria chimica, corredata di esempi di metodologie applicate a processi chimici. Il Chapter II descriver\ue0 i passaggi necessari ad ottenere la valutazione della sostenibilit\ue0 delle alternative impiantistiche. Dal reperimento delle informazioni necessarie, all\u2019implementazione dei modelli nei simulatori di processo, seguito dal calcolo degli indici rappresentativi dei pilastri della sostenibilit\ue0, i cui valori vengono successivamente valutati tramite un algoritmo matematico (DEA) per identificare la configurazione impiantistica ottimale. Infine \ue8 necessario analizzare le alternative inefficienti di modo da comprendere su quali variabili si debba intervenire per migliorarne le prestazioni attraverso una retrofit analisi. Il Chapter III affronter\ue0 l\u2019utilizzo di diverse tecniche di simulazione molecolare per la stima del coefficiente di ripartizione ottanolo-acqua (Kow), che \ue8 un propriet\ue0 fondamentale per il calcolo di alcuni indici utilizzati. Il lettore trover\ue0 alcuni casi di studio descritti nel Chapter IV. Il primo appartiene al ramo della farmaceutica e si occupa della produzione del pioglitazone cloridrato attraverso l\u2019utilizzo di diverse vie di sintesi appartenenti a numerosi brevetti. La seconda applicazione della metodologia riguarda l\u2019industria biochimica e ottimizza le condizioni operative di un reattore utilizzato per la produzione di biodiesel a partire da olio vegetale. L\u2019ultimo caso di studio esplora il mondo dei materiali nanostrutturati, valutando diversi parametri di reazione utilizzati per condurre la sintesi di CdSe quantum dot. L\u2019ultimo Chapter V conterr\ue0 le valutazioni conclusive e le prospettive future.Research activity in chemical engineering is focused on the refinement of theories and techniques employed for the development of new tools aiming at solving issues directly related to the generation of goods and services supplied by chemical, biochemical and pharmaceutical industries. In this context, multiscale approaches revealed to be very useful, since they embrace theories from quantum mechanics at the nanoscale to classical mechanics at the macroscale, contemplating wide perspectives and enabling the adaptation of each theory to an abundance of disparate applications. Furthermore, the acknowledgment of sustainability among the cornerstones of future development led to a copious diffusion of sustainability evaluation methodologies, aiming to account for economic, social and environmental concerns among chemical processes assessments. Therefore, this thesis deals with the development of a multiscale framework for the preliminary screening of chemical process designs, promoting the adoption of various computational tools along with sustainability considerations. The purpose of this methodology resides in the fulfillment of an emblematic need for any production site, i.e. evaluating a production process considering possible modifications from different perspectives in order to identify as fast as possible the most efficient design including economic, social and environmental concerns. The reader will be guided through this topic following the chapters of this dissertation. In Chapter I, the concept of sustainability and sustainable development will be presented, followed by some applications starting from the wider panorama of institutions to the industry perspective, concluding with some relevant examples from chemical process engineering. Chapter II will describe each step to be performed in order to gain the sustainability evaluation of the process alternatives. From retrieving the promising process designs, to implementing each flowsheet in a process simulator, then calculating several indicators based on the sustainability pillars, which is followed by employing a mathematical tool (DEA) in order to select the most efficient designs and finally investigating how to enhance the sub-optimal alternatives through a retrofit analysis. Chapter III will deal with the application of different molecular simulation techniques in order to estimate the octanol-water partition coefficient (Kow), which is an essential parameter for the calculation of several sustainability indicators. Then the reader will encounter the three case studies shown in details in Chapter IV. The first one belongs to the pharmaceutical field and deals with the production of pioglitazone hydrochloride considering different synthesis routes from various patents. The second application regards the biochemical industry, optimizing the operating conditions of a reactor employed for the production of biodiesel from vegetable oil. The last one explores the synthesis of nanomaterials, evaluating several reaction parameters involved in the laboratory production of CdSe quantum dots from a sustainability viewpoint. Some concluding remarks and future perspectives will be included in the final Chapter V

    Foundational Learning and Rehabilitation: An Investigation of the Remedial Strategies of Postsecondary Violin Instructors

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    Applied violin instructors at the postsecondary level often face the task of having to implement rehabilitation (remedial/corrective pedagogy) with incoming first-year students in order to address technical/musical habits or deficiencies. (Burt & Mills, 2006; Rolland, 1974b; Zweig, 2008). If students are not guided appropriately in the critical early stages, they increase their potential of developing poor technical habits or deficiencies that could be carried with them into their future studies (Hallam, 2013; Howe & Sloboda, 1991b; Kempter, 2003; Mills & Smith, 2003; Nerland, 2007). As various motor patterns are formed through habitual reinforcement, incorrect techniques may be strengthened (Salzberg & Salzberg, 1981). Using a descriptive qualitative methodology with elements of multiple case study research design, 10 postsecondary violin instructors from across North America were interviewed to gain insight into personal rehabilitative approaches, influences, experiences, and assessment strategies that they implement with their first-year performance students. The interview data, external data sources, and artifacts were then analyzed through the theoretical framework of empiricism, Social Development Theory, Scaffolding Theory, Attribution Theory, and Teacher Attribution Scaffolding Theory. The results indicated that most first-year violin performance students require remedial work, with posture and the bow arm representing the most pressing deficiencies. The participants had differing opinions in terms of how deficiencies are established, but they agreed that appropriate early instruction is imperative. Many participants believe that through experience, they now address correction based on the individual psychological wellbeing of every student, their level of self-efficacy, resistance to change, and postsecondary pressures. By contrast, other participants view rehabilitation as a necessary part of postsecondary education, regardless of artistic proficiency. The participants agreed that although some first-year students resist correction, the majority of students exhibit an increased sense of self-efficacy through a positive feedback loop of practice, motivation, feedback from their instructors and peers, and tangible documentation of improvement. The pedagogical expertise and applied experiences presented in this study should inform current and future violin pedagogues about the effects of inappropriate early instruction, how to assess the need for rehabilitation, and how to address technical/musical deficiencies effectively

    Sustainability Analysis of Hydrogen Production Processes: a Comparison Based on Sustainability Indicators

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    Hydrogen is a versatile energy carrier and storage medium that may be employed in a variety of applications. It may be produced using different processes. In this work, process simulation is used to obtain material and energy balances for each process investigated, as well as for the evaluation of capital and maintenance costs. Process simulation outcomes are then used to estimate three key performance indicators focusing on sustainability issues: the energy return of energy invested, the levelized cost of hydrogen and the life cycle assessment. We compared several hydrogen generation processes, each denoted by a unique colour code: (i) green hydrogen, produced by electrolysis of water using electricity from renewable sources, (ii) grid hydrogen, produced by electrolysis using grid electricity, (iii) grey hydrogen, produced from natural gas using steam reforming and (iv) blue hydrogen, like grey one, but coupled with carbon capture and storage. In conclusion, the most sustainable hydrogen production method is the green hydrogen, produced by water electrolysis

    Carbon Dioxide Capture in the Iron and Steel Industry: Thermodynamic Analysis, Process Simulation, and Life Cycle Assessment

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    The iron and steel sector is one of the dominant drivers behind economic and social progress, but it is also very energy-intensive and hard-to-abate, making it a major cause of global warming. Improving energy efficiency, introducing hydrogen for direct reduction, and utilising CCS technologies are the three most viable options for reducing CO2 emissions from steel mills. This investigation deals with a life cycle comparison of three different carbon capture processes, the inventory data of which have been obtained using process simulation based on rigorous phase and chemical equilibrium equations. In-silico models for the absorption of carbon dioxide employing MDEA, membranes, or sodium hydroxide to produce sodium bicarbonate have been developed and compared from a life cycle viewpoint. The research findings showed a variable amount of CO2 removal in the three cases, where membranes achieved the best performance (95 % CO2 removal). Since NaOH absorption produces a valuable by-product (sodium bicarbonate, which is commonly produced by Solvay process), the other two technologies were modified to integrate the utilisation of CO2 for the synthesis of sodium bicarbonate with NaOH rather than transporting and storing the carbon dioxide. As a result, this production pathway for sodium bicarbonate generates lower environmental burdens than traditional Solvay process. The environmental performances of the alternatives are nearly equal, even though the environmental impacts associated with capturing the CO2 and subsequently reacting with NaOH are always slightly higher than those involved with reacting directly during absorption. Among the evaluated alternatives, the direct conversion to sodium bicarbonate appears to be the most promising approach for converting CO2 emissions in the steel sector

    PROPOSAL OF SCALE DIAGRAMMATIC FOR QUANTIFICATION OF CERCOSPORA OF BEET

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    Cercospora leaf. Spot (Cercospora beticola) is present in almost all fields where beet (Beta vulgaris) is cultivated and it can cause sugar yielding loss up to 40%. The aim of this work was to design and validate a diagrammatic scale for this disease. For the design of the diagrammatic scale, 95 sugar beet leaves were collected randomly in the metropolitan region of Curitiba, PR. The maximum and minimum proportions of damaged leaf area were considered and the intermediate levels of severity were determined according to "Weber and Fechner’s Stimulus Law". The proposed validation of the diagrammatic scale was conducted from 35 sugar beet leaves with different levels of severity, with and without the proposed diagrammatic scale. The use of the scale provided more accuracy and precision in the visual estimates, being indicated in epidemiological studies and may provide more accurate information in order to develop management strategies for the beet’s Cercospora leaf. SpotA cercosporiose (Cercospora beticola) esta presente praticamente em todos os lugares onde se cultiva beterraba (Beta vulgaris), podendo provocar perda de rendimento de açúcar de até 40%. O objetivo deste trabalho foi elaborar e validar uma escala diagramática para esta doença. Para elaboração da escala diagramática foram coletadas, aleatoriamente, 95 folhas de beterraba, na região Metropolitana de Curitiba, PR. Considerou-se a máxima e mínima proporção de área foliar lesionada e os níveis intermediários de severidade foram determinados seguindo a "Lei do estímulo de Weber e Fechner". A validação foi realizada a partir de 35 folhas de beterraba com diferentes níveis de severidade, sem e posteriormente com o auxílio da escala diagramática proposta. O uso da escala proporcionou maior acurácia e precisão das estimativas visuais, sendo indicada em estudos epidemiológicos e poderá proporcionar informações mais adequadas para estabelecer estratégias de manejo para a cercospora da beterraba

    Genotype-phenotype features of germline variants of the TMEM127 pheochromocytoma susceptibility gene: A 10-year update

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    Purpose: This work aimed to evaluate genotype-phenotype associations in individuals carrying germline variants of transmembrane protein 127 gene (TMEM127), a poorly known gene that confers susceptibility to pheochromocytoma (PHEO) and paraganglioma (PGL). Design: Data were collected from a registry of probands with TMEM127 variants, published reports, and public databases. Main Outcome Analysis: Clinical, genetic, and functional associations were determined. Results: The cohort comprised 110 index patients (111 variants) with a mean age of 45 years (range, 21-84 years). Females were predominant (76 vs 34, P <. 001). Most patients had PHEO (n = 94; 85.5%), although PGL (n = 10; 9%) and renal cell carcinoma (RCC, n = 6; 5.4%) were also detected, either alone or in combination with PHEO. One-third of the cases had multiple tumors, and known family history was reported in 15.4%. Metastatic PHEO/PGL was rare (2.8%). Epinephrine alone, or combined with norepinephrine, accounted for 82% of the catecholamine profiles of PHEO/PGLs. Most variants (n = 63) occurred only once and 13 were recurrent (2-12 times). Although nontruncating variants were less frequent than truncating changes overall, they were predominant in non-PHEO clinical presentations (36% PHEO-only vs 69% other, P <. 001) and clustered disproportionately within transmembrane regions (P <. 01), underscoring the relevance of these domains for TMEM127 function. Integration of clinical and previous experimental data supported classification of variants into 4 groups based on mutation type, localization, and predicted disruption. Conclusions: Patients with TMEM127 variants often resemble sporadic nonmetastatic PHEOs. PGL and RCC may also co-occur, although their causal link requires further evaluation. We propose a new classification to predict variant pathogenicity and assist with carrier surveillance.Fil: Armaiz Pena, Gustavo. University Of Texas Health Science Center At San Antonio;; Estados UnidosFil: Flores, Shahida K.. No especifíca;Fil: Cheng, Zi Ming. No especifíca;Fil: Zhang, Xhingyu. No especifíca;Fil: Esquivel, Emmanuel. No especifíca;Fil: Poullard, Natalie. No especifíca;Fil: Vaidyanathan, Anusha. No especifíca;Fil: Liu, Qianqian. No especifíca;Fil: Michalek, Joel. No especifíca;Fil: Santillan Gomez, Alfredo A.. No especifíca;Fil: Liss, Michael. No especifíca;Fil: Ahmadi, Sara. No especifíca;Fil: Katselnik, Daniel. No especifíca;Fil: Maldonado, Enrique. No especifíca;Fil: Salgado, Sarimar Agosto. No especifíca;Fil: Jimenez, Camilo. No especifíca;Fil: Fishbein, Lauren. No especifíca;Fil: Hamidi, Oksana. No especifíca;Fil: Else, Tobias. No especifíca;Fil: Lechan, Ron. Tufts Medical Center; Estados UnidosFil: Tischler, Art S.. Tufts Medical Center; Estados UnidosFil: Benn, Diana E.. No especifíca;Fil: Dwight, Trisha. University of Technology Sydney; AustraliaFil: Clifton Bligh, Rory. University of Technology Sydney; AustraliaFil: Sanso, Elsa Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones Endocrinológicas "Dr. César Bergada". Gobierno de la Ciudad de Buenos Aires. Centro de Investigaciones Endocrinológicas "Dr. César Bergada". Fundación de Endocrinología Infantil. Centro de Investigaciones Endocrinológicas "Dr. César Bergada"; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Barontini, Marta Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones Endocrinológicas "Dr. César Bergada". Gobierno de la Ciudad de Buenos Aires. Centro de Investigaciones Endocrinológicas "Dr. César Bergada". Fundación de Endocrinología Infantil. Centro de Investigaciones Endocrinológicas "Dr. César Bergada"; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Vincent, Deepa. Massachusetts Institute of Technology; Estados UnidosFil: Aronin, Neil. Massachusetts Institute of Technology; Estados UnidosFil: Biondi, Bernadette. University of Naples Federico II; ItaliaFil: Koops, Maureen. University of Texas Health San Antonio; Estados UnidosFil: Bowhay Carnes, Elizabeth. No especifíca;Fil: Gimenez Roqueplo, Anne Paule. No especifíca;Fil: Alvarez Eslava, Andrea. No especifíca;Fil: Bruder, Jan M.. No especifíca;Fil: Kitano, Mio. No especifíca;Fil: Burnichon, Nelly. No especifíca;Fil: Ding, Yanli. No especifíca;Fil: Dahia, Patricia L. M.. No especifíca

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Observation of gravitational waves from the coalescence of a 2.5−4.5 M⊙ compact object and a neutron star

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    Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

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    Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M&gt;70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0&lt;e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

    Ultralight vector dark matter search using data from the KAGRA O3GK run

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    Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM
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