8 research outputs found
effects of upgraded cooling system and new blade materials on a real gas turbine performance
Abstract The aim of this paper is to study the effects on the performance of a real heavy-duty gas turbine of two different solutions for enhancing turbine blades thermal resistance. An upgrade of the first stator cooling system and the adoption of improved blade materials are simulated exploiting an in-house simulation tool (ESMS). The changes are studied separately in order to point out the positive effects as well as the related risks, such as the side effect of temperature increase on downstream blade rows, to be considered in service operations
Modular tool for the simulation of compressor trains for oil and gas applications
AbstractRecently, in the oil and gas extraction and transportation field, much attention has been paid both to increase efficiency and to reduce the environmental impact of the extraction techniques that, by now, consists mainly on Enhanced Oil Recovery processes based on gas or water injection into the reservoirs. Thus, compressor trains are a crucial part of the overall plant, and they require precise performance estimation during the whole oilfield lifespan, when production rates and compression demands significantly change. For this reason, in compression plant design and in-service behavior prediction, modular simulation codes turns out to be the best choice respect to tools for specific plant configuration, since they provide flexibility without losing accuracy.In this paper, a new modular tool for compression plant simulation is described; it is based on a wide database of centrifugal compressors and a library of elementary components that can be freely assembled to build any plant's configuration, regardless of its layout. The code's numerical solver is the implementation of a trust-region Gauss-Newton method, called TRESNEI, which possess a larger convergence region than standard Newton methods.The performance of the code has been tested on two compression train arrangements with both series and parallel-mounted compressors; comparison with the solution of the test cases obtained with a dedicated pre-existing in-house code, shows a good matching between the results. Computational speed and robustness of the new code is also shown
Enhancement of Tumor Homing by Chemotherapy-Loaded Nanoparticles
Targeted delivery of anticancer drugs with nanocarriers can reduce side effects and ameliorate therapeutic efficacy. However, poorly perfused and dysfunctional tumor vessels limit the transport of the payload into solid tumors. The use of tumor-penetrating nanocarriers might enhance tumor uptake and antitumor effects. A peptide containing a tissue-penetrating (TP) consensus motif, capable of recognizing neuropilin-1, is here fused to a neuroblastoma-targeting peptide (pep) previously developed. Neuroblastoma cell lines and cells derived from both xenografts and high-risk neuroblastoma patients show overexpression of neuropilin-1. In vitro studies reveal that TP\u2013pep binds cell lines and cells derived from neuroblastoma patients more efficiently than pep. TP\u2013pep, after coupling to doxorubicin-containing stealth liposomes (TP\u2013pep\u2013SL[doxorubicin]), enhances their uptake by cells and cytotoxic effects in vitro, while increasing tumor-binding capability and homing in vivo. TP\u2013pep\u2013SL[doxorubicin] treatment enhances the Evans Blue dye accumulation in tumors but not in nontumor tissues, pointing to selective increase of vascular permeability in tumor tissues. Compared to pep\u2013SL[doxorubicin], TP\u2013pep\u2013SL[doxorubicin] shows an increased antineuroblastoma activity in three neuroblastoma animal models mimicking the growth of neuroblastoma in humans. The enhancement of drug penetration in tumors by TP\u2013pep-targeted nanoparticles may represent an innovative strategy for neuroblastoma
Quasi-Newton methods for constrained nonlinear systems: complexity analysis and applications
Whole transcriptome analysis reveals an 8-oxoguanine DNA glycosylase-1-driven DNA repair-dependent gene expression linked to essential biological processes
ContribuiçÔes da Sociologia na AmĂ©rica Latina Ă imaginação sociolĂłgica: anĂĄlise, crĂtica e compromisso social Sociology's contribution in Latin America to sociological imagination: analysis, critique, and social commitment
O artigo aborda o papel desempenhado pela Sociologia na anĂĄlise dos processos de transformação das sociedades latino-americanas, no acompanhamento do processo de construção do Estado e da Nação, na problematização das questĂ”es sociais na AmĂ©rica Latina. SĂŁo analisados seis perĂodos na Sociologia na AmĂ©rica Latina e no Caribe: I) a herança intelectual da Sociologia ; II) a sociologia da cĂĄtedra; III) O perĂodo da "Sociologia CientĂfica" e a configuração da "Sociologia CrĂtica"; IV) a crise institucional, a consolidação da "Sociologia CrĂtica" e a diversificação da sociologia; V) a sociologia do autoritarismo, da democracia e da exclusĂŁo; VI) a consolidação institucional e a mundialização da sociologia da AmĂ©rica Latina (desde o ano de 2000), podendo-se afirmar que os traços distintivos do saber sociolĂłgico no continente foram: o internacionalismo, o hibridismo, a abordagem crĂtica dos processos e conflitos das sociedades latino-americanas e o compromisso social do sociĂłlogo.<br>The article focuses on the role played by Sociology in the analysis of processes of change in Latin American societies, in the process of construction of Nation and State, in the debate of social issues in Latin America and the Caribbean. Six periods in Sociology in Latin America and the Caribbean are examined: I) sociology's intellectual legacy; II) sociology as a cathedra; III) the period of "Scientific Sociology"; IV) the institutional crisis, the consolidation of "Critical Sociology", and the diversifying of sociology; V) sociology of authoritarianism, democracy and exclusion; VI) institutional consolidation and globalization of Latin American sociology (since 2000). It may be said that the distinctive features of sociological knowledge in the continent were: internationalism, hybridism, the critical approach to processes and conflicts of Latin American societies, and the sociologist social commitment
Neotropical ornithology: Reckoning with historical assumptions, removing systemic barriers, and reimagining the future
A major barrier to advancing ornithology is the systemic exclusion of professionals from the Global South. A recent special feature, Advances in Neotropical Ornithology, and a shortfalls analysis therein, unintentionally followed a long-standing pattern of highlighting individuals, knowledge, and views from the Global North, while largely omitting the perspectives of people based within the Neotropics. Here, we review current strengths and opportunities in the practice of Neotropical ornithology. Further, we discuss problems with assessing the state of Neotropical ornithology through a northern lens, including discovery narratives, incomplete (and biased) understanding of history and advances, and the promotion of agendas that, while currently popular in the north, may not fit the needs and realities of Neotropical research. We argue that future advances in Neotropical ornithology will critically depend on identifying and addressing the systemic barriers that hold back ornithologists who live and work in the Neotropics: unreliable and limited funding, exclusion from international research leadership, restricted dissemination of knowledge (e.g., through language hegemony and citation bias), and logistical barriers. Moving forward, we must examine and acknowledge the colonial roots of our discipline, and explicitly promote anti-colonial agendas for research, training, and conservation. We invite our colleagues within and beyond the Neotropics to join us in creating new models of governance that establish research priorities with vigorous participation of ornithologists and communities within the Neotropical region. To include a diversity of perspectives, we must systemically address discrimination and bias rooted in the socioeconomic class system, anti-Blackness, anti-Brownness, anti-Indigeneity, misogyny, homophobia, tokenism, and ableism. Instead of seeking individual excellence and rewarding top-down leadership, institutions in the North and South can promote collective leadership. In adopting these approaches, we, ornithologists, will join a community of researchers across academia building new paradigms that can reconcile our relationships and transform science. Spanish and Portuguese translations are available in the Supplementary Material.âąâResearch conducted by ornithologists living and working in Latin America and the Caribbean has been historically and systemically excluded from global scientific paradigms, ultimately holding back ornithology as a discipline.âąâTo avoid replicating systems of exclusion in ornithology, authors, editors, reviewers, journals, scientific societies, and research institutions need to interrupt long-held assumptions, improve research practices, and change policies around funding and publication.âąâTo advance Neotropical ornithology and conserve birds across the Americas, institutions should invest directly in basic field biology research, reward collective leadership, and strengthen funding and professional development opportunities for people affected by current research policies.Peer reviewe