1,327 research outputs found
Fuel saving and reduction of emissions in ports with cold ironing applications
The progress of economic globalization, the rapid growth of international trade and maritime transportation have played a significant role in providing international cargo and passenger transportation. Seaports all over the world are suffering from the problem of fuel consumption and exhaust gases coming by ships during their stopover in ports. In Italy, the emissions of the industrial and energy sectors have been reduced (almost 50% between 1998 and 2012), but the sulfur oxide (SOx ) from the maritime sector has almost doubled. The national and international maritime traffic is responsible for 80% of total emissions attributable to transportation. In this paper firstly we propose a method to compare the costs of various shore-side power sources connections with those obtained by use of auxiliary engines on board; two numerical examples have been developed. The results, in terms of costs and reduction of exhaust, have been particularly discussed
Evaluation of the environmental impact of harbour activities: problem analisys and possible solutions
A relevant problem is a main subject of this work: the pollution in ports close to inhabited zones where, due to the contemporaneous presence of many cruise ships, the contents of noxious elements in the air are excessive and the quality of life risks to become unsustainable.
The impact of the operations of cruise ships in port has been analysed together with the possible consequences of their impact on the human health and the rules that attempt to reduce the effects of the pollution on it.
Some possible solutions were proposed; first of all, the so called “cold ironing” consisting in a connection between the electric system of the ship and a shore system providing the ship with the electric energy to be used onboard.
The major characteristics of the cold ironing were analysed together with its main problems; among them, the need of integrate this practice in a more wide scene, combining it with the microgrids in order to not to solve the problem simply by moving the production of electric energy from one site to another
A sustainable electrical interface to mitigate emissions due to power supply in ports
The paper presents a proposal of an innovative sustainable power supply solution for seaports with the related design and control. This solution differs from the classical solution for the presence of a smart electrical interface composed by two basic components: the first one, a rotating converter instead of the widely used static converter that ensures higher and therefore much more detectable short-circuit currents; the second, an advanced static var compensator specifically designed for enhancing power quality issues and hence favoring these seaport connection to the main grid for cold ironing applications.
The designed control strategy for the tailored power supply solution is proven successful and effective by the numerical applications reported in the last part of the paper
CARATTERIZZAZIONE ACUSTICA DI NAVI IN PORTO
Le sorgenti acustiche portuali sono molte e variegate: tra queste, le navi occupano un posto di primo piano. La caratterizzazione della sorgente nave non è molto trattata in letteratura e presenta aspetti problematici legati alle dimensioni del mezzo ed alla sua complessità impiantistica. Il testo riporta i risultati di una campagna sperimentale condotta nel porto di Napoli su diversi tipi di imbarcazione in condizioni transitorie e stazionarie. L’attività è propedeutica alla formulazione di un modello di propagazione verso le zone abitate che circondano il porto
Assessment of ambient air quality in the port of Naples
Two experimental monitoring campaigns were carried out in 2012 to investigate the air quality in the port of Naples, the most
important in southern Italy for traffic of passengers and one of the most important for goods. Therefore, it represents an
important air pollution source located close to the city of Naples. The concentrations of sulfur dioxide (SO2), nitrogen dioxide
(NO2), and BTEX (benzene, toluene, ethylbenzene, and xylenes) in the air were measured at 15 points inside the Naples port area
through the use of passive samplers. In addition, a mobile laboratory was positioned in a fixed point inside the port area to
measure continuous concentration of pollutants together with particulate matter, ambient parameters, and wind direction and
intensity. The pollution levels monitored were compared with those observed in the urban area of Naples and in other
Mediterranean ports. Even though the observation time was limited, measured concentrations were also compared with limit
values established by European legislation. All the measured pollutants were below the limits with the exception of nitrogen
dioxide: its average concentration during the exposition time exceeded the yearly limit value. A spatial analysis of data,
according to the measured wind direction and intensity, provided information about the effects that ship emissions have on
ambient air quality in the port area. The main evidence indicates that ship emissions influence sulfur dioxide concentration more
than any other pollutants analyze
On field experimental characterisation of the ship sources of acoustic pollution within a commercial harbour
The noise associated to ship operations within large commercial harbours is an issue because often these infrastructures affect strongly the overall acoustic levels of close residential areas. The dimensions and complexity of the ship noise sources and of the transmission path to the receiver make the sound pressure field particularly complex. In this situation, even an assessment of the acoustic impact of harbours may be particularly difficult to achieve, if based on a purely experimental approach. This situation calls for the use of prediction models that, with a proper calibration, allow exploring with continuity the acoustic field in the areas around the source. Moreover, models become essential when studying corrective actions and comparing their effectiveness. Within this general context, the present work illustrates the preliminary experimental activities carried out in a part of the Naples commercial harbour for the calibration of a numerical model of the noise field associated to the operation of a specific ship. The model, based on a Ray Tracing approach, includes both the main noise sources on board the ship and the surrounding physical structures (buildings and infrastructures characterizing the area). The paper describes the main characteristics of the model and presents the procedure envisaged for its development and calibration. Results of the on-field experimental campaign in a portion of the port of Naples are presented and discussed in view of the identification and characterisation of the ship sources detected and surveyed and of the first part of the propagation path around the ship
Nasal cytology in children: recent advances
Nasal cytology is a very useful diagnostic tool in nasal disorders, being able to detect both the cellular modifications of the nasal epithelium caused by either allergen exposure or irritative stimuli (that may be physical or chemical, acute or chronic), or inflammation. Over these past few years, nasal cytology has allowed to identify new disorders, such as the non-allergic rhinitis with eosinophils (NARES), the non-allergic rhinitis with mast cells (NARMA), the non-allergic rhinitis with neutrophils (NARNE), and the non-allergic rhinitis with eosinophils and mast cells (NARESMA). The rhinocytogram is actually able to distinguish the different forms of allergic rhinitis and to suggest the appropriate treatment, such as antinflammatory drugs or allergen immunotherapy. The technique is easy to perform and nasal cytology is therefore particularly suitable even for children. Such a consideration suggests the utility of a systematic use of nasal cytology in the diagnostic work-up of nasal disorders in children, in order to reach a proper defined diagnosis and to set a rational therapeutic approach: in facts, these two elements are fundamental in order to prevent from complications and to improve the patient’s quality of life
Co-Transplantation of endothelial progenitor cells and pancreatic islets to induce long-lasting normoglycemia in streptozotocin-treated diabetic rats
Graft vascularization is a crucial step to obtain stable normoglycemia in pancreatic islet transplantation. Endothelial progenitor cells (EPCs) contribute to neoangiogenesis and to the revascularization process during ischaemic events and play a key role in the response to pancreatic islet injury. In this work we co-transplanted EPCs and islets in the portal vein of chemically-induced diabetic rats to restore islet vascularization and to improve graft survival. Syngenic islets were transplanted, either alone or with EPCs derived from green fluorescent protein (GFP) transgenic rats, into the portal vein of streptozotocin-induced diabetic rats. Blood glucose levels were monitored and intraperitoneal glucose tolerance tests were performed. Real time-PCR was carried out to evaluate the gene expression of angiogenic factors. Diabetic-induced rats showed long-lasting (6 months) normoglycemia upon co-transplantation of syngenic islets and EPCs. After 3–5 days from transplantation, hyperglycaemic levels dropped to normal values and lasted unmodified as long as they were checked. Further, glucose tolerance tests revealed the animals' ability to produce insulin on-demand as indexed by a prompt response in blood glucose clearance. Graft neovascularization was evaluated by immunohistochemistry: for the first time the measure of endothelial thickness revealed a donor-EPC-related neovascularization supporting viable islets up to six months after transplant. Our results highlight the importance of a newly formed viable vascular network together with pancreatic islets to provide de novo adequate supply in order to obtain enduring normoglycemia and prevent diabetes-related long-term health hazards
Magnetic carbon nanotubes: a new tool for shepherding mesenchymal stem cells by magnetic fields
We investigated the interaction between magnetic carbon nanotubes (CNTs) and mesenchymal stem cells (MSCs), and their ability to guide these intravenously injected cells in living rats by using an external magnetic field.
MATERIALS & METHODS:
Multiwalled CNTs were used to treat MSCs derived from rat bone marrow. Cytotoxicity induced by nanotubes was studied using the WST-1 proliferation and Hoechest 33258 apoptosis assays. The effects of nanotubes on MSCs were evaluated by monitoring the effects on cellular growth rates, immunophenotyping and differentiation, and on the arrangement of cytoskeletal actin. MSCs loaded with nanotubes were injected in vivo in the portal vein of rats driving their localization in the liver by magnetic field. An histological analysis was performed on the liver, lungs and kidneys of all animals.
RESULTS:
CNTs did not affect cell viability and their ability to differentiate in osteocytes and adipocytes. Both the CNTs and the magnetic field did not alter the cell growth rate, phenotype and cytoskeletal conformation. CNTs, when exposed to magnetic fields, are able to shepherd MSCs towards the magnetic source in vitro. Moreover, the application of a magnetic field alters the biodistribution of CNT-labelled MSCs after intravenous injection into rats, increasing the accumulation of cells into the target organ (liver).
CONCLUSION:
Multiwalled CNTs hold the potential for use as nanodevices to improve therapeutic protocols for transplantation and homing of stem cells in vivo. This could pave the way for the development of new strategies for the manipulation/guidance of MSCs in regenerative medicine and cell transplantation
Ensino da educação física na educação infantil: dificuldades e possibilidades
Qual profissional deverá assumir a prática da educação física na Educação Infantil? Essa é uma questão ainda não resolvida no Brasil. Historicamente, foram os professores polivalentes que assumiram tal tarefa. No entanto, hoje há perspectiva de que os professores licenciados em Educação Física ministrem aulas para o segmento. Em ambos os casos existem dificuldades a superar: a formação inicial dos docentes; as condições institucionais; as ambiguidades epistemológicas decorrentes das especificidades no trato da infância e a fragilidade das equipes pedagógicas escolares. Nesse cenário de complexidade, o objetivo deste estudo é compreender as condições e dificuldades pedagógicas que enfrentam professores de Educação Física na Educação Infantil e as possibilidades de avançar nas perspectivas pedagógicas para a infância. A pesquisa foi realizada em um município do estado de São Paulo que optou pelo trabalho de professores de Educação Física na Educação Infantil. Utilizamo-nos de dados de questionários e entrevistas realizadas com professores e supervisoras de ensino, triangulando-os através da análise de conteúdos e trabalhos hermenêuticos de interpretação. Os dados permitiram compreender que há necessidade de que os currículos dos cursos de formação considerem as crianças pequenas com mais profundidade; analisando suas especificidades e possibilidades formativas e que olhar para a criança e seu movimento expressivo deve constituir o roteiro didático para o planejamento de atividades e sentidos da aprendizagem. Concluímos, ainda, que o trabalho pedagógico com crianças pequenas requer que o coletivo dos docentes se integre à formação continuada e que as atividades se desenvolvam de forma interdisciplinar
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