1,043 research outputs found

    Numerical Analysis of NOₓ Reduction Using Ammonia Injection and Comparison With Water Injection

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    [Abstract] This work analyzes NOₓ reduction in a marine diesel engine using ammonia injection directly into the cylinder and compares this procedure with water injection. A numerical model based on the so-called inert species method was applied. It was verified that ammonia injection can provide almost 80% NOₓ reduction for the conditions analyzed. Furthermore, it was found that the effectiveness of the chemical effect using ammonia is extremely dependent on the injection timing. The optimum NOₓ reduction was obtained when ammonia is injected during the expansion stroke, while the optimum injection timing using water is near top dead center. Chemical, thermal, and dilution effects of both ammonia and water injection were compared. The chemical effect was dominant in the case of ammonia injection. On the other hand, water injection reduces NOₓ through dilution and, more significantly, through a thermal effect

    An analysis of the use of accounting information by portuguese SMEs

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    Despite the significant economic contribution of small and medium-sized enterprises (SMEs), little is known about the extent to which they make use of accounting information (AI). Although AI is considered one of the main sources of information for SMEs, many continue to ignore its potential, considering that this information is only intended to meet tax obligations. The literature stresses the influence of several factors on AI usage. However, the conclusions of the studies are fragmented, contradictory, and not very enlightening. Following these studies, the purpose of this paper is to explore which characteristics of decision makers, companies, and accounting services influence the importance and use of AI in SMEs. Data were collected through an online questionnaire survey applied to Portuguese SMEs. The findings show that the decision makers’ level of education, as well as their educational background, influence the importance they attribute to AI. It has also been found that smaller companies and SMEs that use outsourced accounting services make the least use of AI. Therefore, in addition to providing empirical evidence on the importance and use of AI, a debate that has been mainly theoretical, and on the importance of SMEs in any economy, this paper aims to raise awareness of the need to further study the decision-making process in such firms.info:eu-repo/semantics/publishedVersio

    Detection of adulterations in tradictional portuguese game meat products by polymerase chain reaction technique

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    Authenticity assessment and fraud detection in processed meat products have becn attracting an increased attention driven by public health, economic and legal cancems, and also for religiolls reasons. Currcntly, ooe af the major issues conceming adulterations in the meat indust:ry regards the fraudulent substitution af higher commercial valued meat species by less expensive oDes [1]. The manufacture af traditional meat products is a long-established practice in the Northeast of Portugal. One of the most appreciated products is called "Alheiras", which are traditional smoked fermented sausages, mainly produced with pork and poultry meat. In addition to the two Portuguese Alheiras with Protected Geographical Indication (pGI), other types of "Alheiras" are now available in the market, including the ones produced with game meat. Due to the game meat particular taste, intense Oavour and seasonality, it generally eommands higher prices compared to other meats [1]. Sinee game meat "Alheiras" should, totally or partially, include different types of game meat, they are particularly prone to fraudulent meat substitutions

    Species identification and authentication of hare (Lepus) meat by the use of the mitochondrial cytb gene

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    Nowadays, consumers are increasingly concerned with issues of food safety and authenticity. In particular, game meat has been much appreciated by consumers for their exotic flavour and texture, low in fat and cholesterol as well as by the absence of steroids or other drugs. Food authenticity assessment is important in that it avoids unfair competition among producers and allows consumers to have accurate information about the products they purchase. Therefore, it is important to ensure that species of high commercial value declared are not replaced by other species of lesser value [I]

    Cyclophosphamide and human organ transplantation.

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    Cyclophosphamide, a drug that has not previously had an important role in whole-organ transplantation, was given as a primary immunosuppressant to one liver and eleven kidney recipients, in combination with prednisone and horse antilymphocyte globulin. One of the patients died despite good renal-graft function. Two kidneys from a common cadaveric donor failed. The other nine patients have excellent function of their homografts after 2-3 months. Cyclophosphamide was substituted for azathioprine in one hepatic and five renal recipients who were suspected of having liver toxicity from azathioprine 3 months to almost 8 years post-transplantation. Graft function was maintained after this change, and the evidence of liver injury subsided. © 1971

    tri-n-butyltin hydride-mediated radical reaction of a 2-iodobenzamide: Formation of an unexpected carbon-tin bond

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    Leonardo S. Santos. Instituto de Química de Recursos Naturales, Universidad de Talca, P.O. Box 747, Talca - Chile.The tri-n-butyltin hydride-mediated reaction of methyl 2,3-di-O-benzyl-4-O-trans-cinnamyl -6-deoxy-6-(2-iodobenzoylamino)-a-D-galactopyranoside afforded an unexpected aryltributyltin compound. The structure of this new tetraorganotin(IV) product has been elucidated by 1H, 13C NMR spectroscopy, COSY and HMQC experiments and electrospray ionization mass spectrometry (ESI-MS). The formation of this new compound via a radical coupling reaction and a radical addition-elimination process is discusse

    Magneto-optical trap for metastable helium at 389 nm

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    We have constructed a magneto-optical trap (MOT) for metastable triplet helium atoms utilizing the 2 3S1 -> 3 3P2 line at 389 nm as the trapping and cooling transition. The far-red-detuned MOT (detuning Delta = -41 MHz) typically contains few times 10^7 atoms at a relatively high (~10^9 cm^-3) density, which is a consequence of the large momentum transfer per photon at 389 nm and a small two-body loss rate coefficient (2 * 10^-10 cm^3/s < beta < 1.0 * 10^-9 cm^3/s). The two-body loss rate is more than five times smaller than in a MOT on the commonly used 2 3S1 -> 2 3P2 line at 1083 nm. Furthermore, we measure a temperature of 0.46(1) mK, a factor 2.5 lower as compared to the 1083 nm case. Decreasing the detuning to Delta= -9 MHz results in a cloud temperature as low as 0.25(1) mK, at small number of trapped atoms. The 389 nm MOT exhibits small losses due to two-photon ionization, which have been investigated as well.Comment: 11 page

    Heat stress and ACTH administration on cortisol and insulin-like growth factor I (IGF-I) levels in lactating Holstein cows

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    Physiological and productive responses were studied in five Holstein cows in thermal comfort (T1), stress by exogenous adrenocorticotropic hormone (ACTH) administration (T2) and heat stress (T3) to compare acute and punctual stress (ACTH) and prolonged stress (heat stress). During T1 and T2, cows were housed in a climatic-free stall barn. In T3, the animals were kept in a climatic room (air temperature of 37°C from 08:00 to 13:00 h, and of 26°C from 14:00 to 07:00 h) for 7 days. Milk yield, rectal temperature (RT), respiratory rate (RR) and blood samples were obtained before, during and after all treatments. In T1 at 08:00 h, RT and RR were below the upper critical limit. Simultaneously, cortisol and insulin growth-factor I (IGF-I) were within the normal limits. After ACTH administration (T2), cortisol significantly increased, reaching maximum levels at 60 min and returning to basal levels at 300 min. However, IGF-I was not affected. During T3, Holstein cows did not effectively dissipate their body temperature and RT, RR and cortisol significantly increased. There was a 26.6% reduction in milk production after heat stress (P < .05). Prolonged heat stress was more stressful and cows had higher levels of CORT in T3 than in T2 even before the increase in body temperature. Although the total amount of cortisol and IGF-I presented a negative and significant Pearson correlation (r = −0.79), IGF-I was not significantly influenced by heat stress or ACTH administration, and the relationship between IGF-I and heat stress remains controversial

    Favorabilidade Climática Para A Ferrugem Do Eucalipto No Estado Do Paraná

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    The culture of eucalyptus in the state of Paraná, Brazil, provides raw materials for the production of cellulose, coal, treated wood and lumber. Among the major fungal diseases, rust caused by Puccinia psidii can be pointed out as the most important one. Several forms to control this disease can be cited, especially the planting of resistant clones in areas of climatic conditions less favorable to the occurrence of this disease. The choice for areas of low climatic risks can be made by means of climate zoning. Thus, the aim of this study was to develop a climate favorability zoning for Eucalyptus rust, in Paraná State, Brazil, based on temperature and leaf wetness duration for urediniospore germination and infection by P. psidii. These data were applied in models to produce monthly maps of the disease distribution, according to the favorability to the disease occurrence: ‘highly favorable’, ‘favorable’, ‘scarcely favorable’ and ‘unfavorable’. The generated maps were validated by means of comparison with points of natural rust occurrence in Paraná State. It was concluded that spring and summer were the seasons most favorable to the disease, whereas winter was the least favorable season. The central region of the state, in the zone of transition between the tropical climate of the North and the temperate climate of the South, is more favorable to the occurrence of rust, and the South and the North regions are less favorable for different reasons, due to the low temperature and humidity, respectively. © 2016, Universidade Estadual Paulista (UNESP). All rights reserved.421244
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