234 research outputs found

    EXERGETIC ANALYSIS OF AN INTERNAL COMBUSTION ENGINE RUNNING ON E22 AND E100

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    The internal combustion engine performance enhancement is a widely explored subject. Additionally, to pollutant emissions attention, reducing fuel consumption and consequently the greenhouse gas emissions is one of the leading research and development drivers for the future of the engines industry. As the technologies to increase global engine efficiency are becoming less promising (already reaching improvement limits), the next round would be developing technologies capable of recovering the energy rejected to the environment, especially by cooling and exhaust systems. The internal combustion engine efficiency is mainly assessed by its global efficiency, which consists of an energy balance. The exergy analysis enhances the classic energy analysis from the concept of maximum possible work, including the rejected energy, consisting of a handy tool for the feasibility study of energy recovery systems. This article presents and contrasts the energy and the exergy analyses of a flex-fuel internal combustion engine running on its top global efficiency condition. The boundary fuels are hydrous ethanol (E100) and gasoline blend (E22), available fuels in Brazil. The hydrous ethanol fuel properties (octane number, air-fuel ratio, and vaporization enthalpy) theoretically result in higher energetic engine efficiency than E22 in the same engine hardware, with a fixed compression ratio. Preliminary results of this study point 4,5% higher global engine efficiency running on E100 compared to E22. The higher engine energy efficiency running on E100 than E22 does not happen in the Second Law analysis. The classic exergetic efficiency, based on engine brake power, is similar for E22 and E100. The maximum exergetic efficiency, based on destroyed exergy, is 4,1% higher for E22 compared to E100. The estimation and comparison of the exergy rejected to the cooling and the exhaust systems according to the boundary fuel (about 21 kW on average in this case), is fundamental to assess the potential and the availability of any recovery system eventually implemented in the internal combustion engine

    Do Akiskal & Mallya's affective temperaments belong to the domain of pathology or to that of normality?

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    BACKGROUND: Kraepelin and Kretschmer hypothesized a continuum between full-blown affective pathology and premorbid temperaments. More recently Akiskal proposed a putative adaptive role for the four fundamental temperaments: the hyperthymic one characterized by emotional intensity, the cyclothymic one by emotional instability, the depressive one by a low energy level, and the irritable one by an excessive response to stimuli. Today it is widely debated whether affective temperaments belong to the domain of pathology or to that of normality. PURPOSE: To make clear, by applying an integrated model, the position of affective temperaments within the continuum between normality and pathology. METHODS: We reviewed several papers that explore the distribution of affective temperaments among the general population, and their involvement both in pathological conditions (somatic and psychiatric) and in human activities (professions and other occupations). RESULTS: Far from being intrinsically pathological conditions, affective temperaments seem to represent adaptive dispositions whose dysregulation can lead to full-blown affective pathology. All the temperamental types display some impact on people's lives by influencing personal skills and professional choices over a wide field of human activities. CONCLUSIONS: Affective temperaments are not problematic when they appear in a mild form, but when they occur in extreme form we have observed a gap between the hyperthymic temperament, which represents the most functional and desirable, and the cyclothymic, depressive, irritable and phobic anxious ones, which are closer to mood, anxiety, and substance use disorders, and imply a component of somatic diseases and life stressors

    Towards Space Deployment of the NDSA Concept for Tropospheric Water Vapour Measurements

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    A novel measurement concept specifically tuned to monitoring tropospheric water vapour's vertical distribution has been demonstrated on a theoretical basis and is currently under development for space deployment. The NDSA (Normalised Differential Spectral Attenuation) technique derives the integrated water vapour (IWV) along the radio link between a transmitter and a receiver carried by two LEO satellites, using the linear correlation between the IWV and a parameter called spectral sensitivity. This is the normalised incremental ratio of the spectral attenuation at two frequencies in the Ku and K bands, with the slope of the water vapour absorption line at 22.235 GHz. Vertical profiles of WV can be retrieved by inverting a set of IWV measurements acquired in limb geometry at different tangent altitudes. This paper provides a comprehensive insight into the NDSA approach for sounding lower tropospheric WV, from the theoretical investigations in previous ESA studies, to the first experimental developments and testing, and to the latest advancements achieved with the SATCROSS project of the Italian Space Agency. The focus is on the new results from SATCROSS activities; primarily, on the upgrading of the instrument prototype, with improved performance in terms of its power stability and the time resolution of the measurements. Special emphasis is also placed on discussing tomographic inversion methods capable of retrieving tropospheric WV content from IWV measurements, i.e., the least squares and the external reconstruction approaches, showing results with different spatial features when applied to a given atmospheric scenario. The ultimate goal of deploying the NDSA measurement technique from space is thoroughly examined and conclusions are drawn after presenting the results of an Observing System Simulation Experiment conducted to assess the impact of NDSA data assimilation on environmental model simulations

    Detecting myocardial salvage after primary PTCA: early myocardial contrast echocardiography versus delayed Sestamibi perfusion imaging.

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    Do rebreathing manoeuvres for non-invasive measurement of cardiac output during maximum exercise test alter the main cardiopulmonary parameters?

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    Background: Inert gas rebreathing has been recently described as an emergent reliable non-invasive method for cardiac output determination during exercise, allowing a relevant improvement of cardiopulmonary exercise test clinical relevance. For cardiac output measurements by inert gas rebreathing, specific respiratory manoeuvres are needed which might affect pivotal cardiopulmonary exercise test parameters, such as exercise tolerance, oxygen uptake and ventilation vs carbon dioxide output (VE/VCO2) relationship slope. Method: We retrospectively analysed cardiopulmonary exercise testing of 181 heart failure patients who underwent both cardiopulmonary exercise testing and cardiopulmonary exercise test+cardiac output within two months (average 16 \ub1 15 days). All patients were in stable clinical conditions (New York Heart Association I\u2013III) and on optimal medical therapy. Results: The majority of patients were in New York Heart Association Class I and II (78.8%), with a mean left ventricular ejection fraction of 31 \ub1 10%. No difference was found between the two tests in oxygen uptake at peak exercise (1101 (interquartile range 870\u20131418) ml/min at cardiopulmonary exercise test vs 1103 (844\u20131389) at cardiopulmonary exercise test-cardiac output) and at anaerobic threshold. However, anaerobic threshold and peak heart rate, peak workload (75 (58\u2013101) watts and 64 (42\u201390), p < 0.01) and carbon dioxide output were significantly higher at cardiopulmonary exercise testing than at cardiopulmonary exercise test+cardiac output, whereas VE/VCO2 slope was higher at cardiopulmonary exercise test+cardiac output (30 (27\u201335) vs 33 (28\u201337), p < 0.01). Conclusion: The similar anaerobic threshold and peak oxygen uptake in the two tests with a lower peak workload and higher VE/VCO2 slope at cardiopulmonary exercise test+cardiac output suggest a higher respiratory work and consequent demand for respiratory muscle blood flow secondary to the ventilatory manoeuvres. Accordingly, VE/VCO2 slope and peak workload must be evaluated with caution during cardiopulmonary exercise test+cardiac output

    Dog skin parasite load, TLR-2, IL-10 and TNF-α expression and infectiousness

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    Visceral leishmaniosis is a zoonotic disease that is transmitted by Lutzomyia longipalpis sandflies. Dogs are the main peri-urban reservoir of the disease, and progression of canine leishmaniosis is dependent on the type of immune response elaborated against the parasite. Type 1 immunity is characterized by effective cellular response, with production of pro-inflammatory cytokines such as tumour necrosis factor alpha (TNF-α). In contrast, Type 2 immunity is predominantly humoral, associated with progression of the disease and mediated by anti-inflammatory cytokines such as interleukin 10 (IL-10). Although seemly important in the dynamics of leishmaniosis, other gene products such as toll-like receptor 2 (TRL-2) and inducible nitric oxide synthase (iNOS) exert unclear roles in the determination of the type of immune response. Given that the dog skin serves as a micro-environment for the multiplication of Leishmania spp., we investigated the parasite load and the expression of TLR-2, iNOS, IL-10 and TNF-α in the skin of 29 infected and 8 control dogs. We found that increased parasite load leads to upregulation of TLR-2, IL-10 and TNF-α, indicating that abundance of these transcripts is associated with infection. We also performed a xenodiagnosis to demonstrate that increased parasitism is a risk factor for infectiousness to sandflies

    The Genome Sequence of Leishmania (Leishmania) amazonensis: Functional Annotation and Extended Analysis of Gene Models

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    We present the sequencing and annotation of the Leishmania (Leishmania) amazonensis genome, an etiological agent of human cutaneous leishmaniasis in the Amazon region of Brazil. L. (L.) amazonensis shares features with Leishmania (L.) mexicana but also exhibits unique characteristics regarding geographical distribution and clinical manifestations of cutaneous lesions (e.g. borderline disseminated cutaneous leishmaniasis). Predicted genes were scored for orthologous gene families and conserved domains in comparison with other human pathogenic Leishmania spp. Carboxypeptidase, aminotransferase, and 3'-nucleotidase genes and ATPase, thioredoxin, and chaperone-related domains were represented more abundantly in L. (L.) amazonensis and L. (L.) mexicana species. Phylogenetic analysis revealed that these two species share groups of amastin surface proteins unique to the genus that could be related to specific features of disease outcomes and host cell interactions. Additionally, we describe a hypothetical hybrid interactome of potentially secreted L. (L.) amazonensis proteins and host proteins under the assumption that parasite factors mimic their mammalian counterparts. the model predicts an interaction between an L. (L.) amazonensis heat-shock protein and mammalian Toll-like receptor 9, which is implicated in important immune responses such as cytokine and nitric oxide production. the analysis presented here represents valuable information for future studies of leishmaniasis pathogenicity and treatment.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo, EPM UNIFESP, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, BR-04023062 São Paulo, BrazilLNBio CNPEM, Lab Nacl Biociencias, Campinas, SP, BrazilLGE UNICAMP, Lab Genom & Expressao, Campinas, SP, BrazilInst Agron Campinas, Ctr Pesquisa & Desenvolvimento Recursos Geneti Ve, Campinas, SP, BrazilUniv Calif San Diego, Sch Med, Dept Pediat, San Diego, CA 92103 USAUniversidade Federal de São Paulo, UNIFESP, Dept Ciencia & Tecnol, Sao Jose Dos Campos, BrazilUniv N Carolina, Sch Med, Dept Genet, Chapel Hill, NC USAUniv Fed Minas Gerais, ICB UFMG, Inst Ciencias Biol, Dept Biol Geral, Belo Horizonte, MG, BrazilUniversidade Federal de São Paulo, EPM UNIFESP, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, UNIFESP, Dept Ciencia & Tecnol, Sao Jose Dos Campos, BrazilFAPESP: 07/50551-2FAPESP: 10/19335-4Web of Scienc
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