Waste heat recovery technologies for offshore platforms

none5siThis article aims at finding the most suitable waste heat recovery technology for existing and future offshore facilities. The technologies considered in this work are the steam Rankine cycle, the air bottoming cycle and the organic Rankine cycle. A multi-objective optimization approach is employed to attain optimal designs for each bottoming unit by selecting specific functions tailored to the oil and gas sector, i.e. yearly CO2 emissions, weight and economic revenue. The test case is the gas turbine-based power system serving an offshore platform in the North Sea. Results indicate that the organic Rankine cycle technology presents larger performances compared to steam Rankine cycle units, whereas the implementation of air bottoming cycle modules is not attractive from an economic and environmental perspective compared to the other two technologies. Despite the relatively high cost of the expander and of the primary heat exchanger, organic Rankine cycle turbogenerators appear thus to be the preferred solution to abate CO2 emissions and pollutants on oil and gas facilities. As a practical consequence, this paper provides guidelines for the design of high-efficiency, cost-competitive and low-weight power systems for offshore installationsrestrictedL. Pierobon;A. Benato;E. Scolari;F. Haglind;A. StoppatoL., Pierobon; Benato, Alberto; E., Scolari; F., Haglind; Stoppato, Ann

Surgery for Recurrent Pancreatic Cancer: Is It Effective?

Despite improvements to surgical procedures and novel combinations of drugs for adjuvant and neoadjuvant therapies for pancreatic adenocarcinoma, the recurrence rate after radical surgery is still high. Little is known about the role of surgery in the treatment of isolated recurrences of pancreatic cancer. The aim of this study was to review the current literature dealing with surgery for recurrent pancreatic cancer in order to examine its feasibility and effectiveness. An extensive literature review was conducted according to the 2009 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and 14 articles dealing with re-resections for recurrent pancreatic adenocarcinoma were analyzed, focusing on the characteristics of the primary neoplasm and its recurrence, the surgical procedures used, and patient outcomes. Data were retrieved on a total of 301 patients. The interval between surgery for primary pancreatic cancer and the detection of a recurrence ranged from 2 to 120 months. The recurrence was local or regional in 230 patients, and distant in 71. The median overall survival was 68.9 months (range 3-152) after resection of the primary tumor, and 26.0 months (range 0-112) after surgery for recurrent disease. The disease-free interval after the resection of recurrences was 14.2 months (range 4-29). Although data analysis was performed on a heterogeneous and limited number of patients, some of these may benefit from surgery for isolated recurrence of pancreatic adenocarcinoma. Further studies are needed to identify these cases

Safety and Efficacy of Surgery for Metastatic Tumor to the Pancreas: A Single-Center Experience

Pancreatic metastases from other neoplasms are rare. The role of surgery for this clinical entity is unclear. The aim of this study was to investigate the role of resection in patients with pancreatic secondary lesions. We observed 44 patients with pancreatic metastases from other tumors. Renal cell carcinoma was the most common primary tumor (n = 19, 43.2%). Thirty-seven patients underwent surgery, and pancreatic resection with curative intent was feasible in 35 cases. Fifteen patients (43.2%) experienced major postoperative complications (Clavien-Dindo > 2), and postoperative mortality rate was 5.4%. The median overall survival and disease-free survival were 38 (range 0–186) and 11 (range 0–186) months, respectively. Overall survival and disease-free survival were significantly longer for pancreatic metastases from renal cell carcinoma when compared to other primary tumors. Multivariate analysis confirmed a pathological diagnosis of metastasis from RCC as an independent prognostic factor for overall survival (OR 2.48; 95% CI, 1.00–6.14; p = 0.05). In conclusion, radical resection of metastases to the pancreas is feasible and safe, and may confer a survival benefit for selected patients. There is a clear benefit of metastasectomy in terms of patient survival for metastases from renal cell carcinoma, while for those with other primary tumors, surgery seems to be mainly palliative

Exploring the physical channel of diffusion-based molecular communication by simulation

Diffusion-based molecular communication is a promising bio-inspired paradigm to implement nanonetworks, i.e., the interconnection of nanomachines. The peculiarities of the physical channel in diffusion-based molecular communication require the development of novel models, architectures and protocols for this new scenario, which need to be validated by simulation. With this purpose, we present N3Sim, a simulation framework for diffusion-based molecular communication. N3Sim allows to simulate scenarios where transmitters encode the information by releasing molecules into the medium, thus varying their local concentration. N3Sim models the movement of these molecules according to Brownian dynamics, and it also takes into account their inertia and the interactions among them. Receivers decode the information by sensing the particle concentration in their neighborhood. The benefits of N3Sim are multiple: the validation of channel models for molecular communication and the evaluation of novel modulation schemes are just a few examples.Peer ReviewedPostprint (author’s final draft

The Role of Positron Emission Tomography in Clinical Management of Intraductal Papillary Mucinous Neoplasms of the Pancreas

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas represent a heterogeneous group of tumors, increasingly diagnosed in clinical practice. An early differential diagnosis between malignant and benign lesions is crucial to patient management and the choice of surgery or observation. The therapeutic approach is currently based on a patient's clinical, biochemical, and morphological characteristics. The latest published International Consensus Guidelines (ICG) make no mention of the role of metabolic assessments of IPMNs. The aim of this study was to review the current literature, examining the role of 18-fluorodeoxyglucose (FDG) positron emission tomography (PET) in IPMN management. An extensive literature review was conducted according to the 2009 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and 10 articles were analyzed in detail, focusing on the value of PET as opposed to other standard imaging criteria. Data were retrieved on 419 patients. The 18-FDG-PET proved more sensitive, specific, and accurate than the ICG criteria in detecting malignant IPMNs (reaching 80%, 95%, and 87% vs. 67%, 58%, and 63%, respectively). Metabolic assessments may be used as an additional tool for the appropriate management of patients with doubtful imaging findings

Carbamazepine-induced thrombocytopenic purpura in a child: Insights from a genomic analysis

To the Editor, Carbamazepine is an effective anticonvulsant and has a relatively low incidence of adverse effects, although it occasionally causes hema- tologic disorders. We herein describe a patient with carbamazepine- induced thrombocytopenic purpura that was investigated by pharma- cological, immunological and genomic assays

Desenvolvimento in vitro de Cattleya loddigesii Lindley (Orchidaceae) utilizando fertilizantes comerciais

A propagação massal via semeadura in vitro constituí ferramenta indispensável para propagação das principais espécies de orquídeas em extinção, como por exemplo, Cattleya loddigesii Lindl., a qual devido a ampla utilização na obtenção de híbridos acabou ocupando lugar de destaque em lista de espécies ameaçadas. Devido a este fator, o presente trabalho teve por objetivo estudar aspectos do desenvolvimento in vitro da espécie mediante avaliação do efeito dos meios de cultura MS, e de dois meios à base dos fertilizantes Hyponex e Kristalon laranja. Após 180 dias de cultivo, inferiu-se que o meio de cultura mais eficiente para a germinação e desenvolvimento in vitro de sementes é o à base de fertilizante Kristalon laranja, que apresentou as maiores médias para altura da planta, peso da matéria fresca e seca e comprimento da maior raiz e folha, podendo dessa forma ser utilizado tanto comercialmente quanto em programas de semeadura para recomposição de áreas degradadas, por apresentar maior facilidade e baixo custo de produção

Desenvolvimento in vitro de Dendrobium nobile Lindl. (Orchidaceae) em recipientes de diferentes volumes

Commercial cultivation of Dendrobium nobile Lindl. is of great importance to the agribusiness floricultural world, but the slow development of the plant contributes to the high unit value of the plant in the market. The massal propagation through sowing seeds in vitro is an important method for propagation orchid commercial species. The type of the flasks and the amount of culture medium used are variables that have received little attention although they directly affect the superficial area of the medium-air culture interface, depth, volume of air over the culture medium, and the identification of the ideal vessels for each species can optimize the production. The present study aimed to evaluate the in vitro development of D. nobile seedlings in different size vessels, each containing the same volume of MS culture (30 mL). D nobile seeds were inoculated in flasks of 100 mL, 200 mL, and 400 mL and cultivated in BOD for 180 days. The results showed that the development of the D. nobile seedlings was promoted by the use of 100 mL-flasks, which could then be used for commercial propagation. Comercialmente, o cultivo de Dendrobium nobile Lindl. é de grande importância para o agronegócio florícola mundial, mas seu lento desenvolvimento contribui para o elevado valor unitário da planta no mercado. A propagação massal via semeadura in vitro constitui ferramenta indispensável para propagação das principais espécies de orquídeas comerciais. O tipo de frasco e a quantidade de meio de cultura utilizado são variáveis que têm merecido pouca atenção, embora afetem diretamente a área superficial da interface meio de cultura-atmosfera, a profundidade e o volume de ar sobre o meio de cultura, sendo que o emprego do recipiente ideal para cada espécie pode otimizar sua velocidade de produção. O presente trabalho objetivou avaliar o desenvolvimento in vitro de plântulas de D. nobile em recipientes de diferentes tamanhos, contendo o mesmo volume de meio de cultura MS (30 mL). Sementes de D. nobile foram inoculadas em frascos de 100 mL, 200 mL e 400 mL e cultivadas em BOD por 180 dias. Os resultados demonstraram que o desenvolvimento de plântulas de D. nobile foi promovido pelo uso de frascos de 100 mL, os quais podem ser utilizados para propagação comercial