Analysis of diametrical wear of grinding wheel and roundness errors in the machining of steel VC 131

Due to the high industrial competitiveness, the rigorous laws of environmental protection, the necessary reduction of costs, the mechanical industry sees itself forced to worry more and more with the refinement of your processes and products. In this context, can be mentioned the need to eliminate the roundness errors that appear after the grinding process. This work has the objective of verifying if optimized nozzles for the application of cutting fluid in the grinding process can minimize the formation of the roundness errors and the diametrical wear of grinding wheel in the machining of the steel VC 131 with 60 HRc, when compared to the conventional nozzles. These nozzles were analyzed using two types of grinding wheels and two different cutting fluids. Was verified that the nozzle of 3mm of diameter, integral oil and the CBN grinding wheel, were the best options to obtain smaller roundness errors and the lowest diametrical wears of grinding wheels.

Using cubic splines to mitigate systematic errors in GPS relative positioning

Systematic errors can have a significant effect on GPS observable. In medium and long baselines the major systematic error source are the ionosphere and troposphere refraction and the GPS satellites orbit errors. But, in short baselines, the multipath is more relevant. These errors degrade the accuracy of the positioning accomplished by GPS. So, this is a critical problem for high precision GPS positioning applications. Recently, a method has been suggested to mitigate these errors: the semiparametric model and the penalised least squares technique. It uses a natural cubic spline to model the errors as a function which varies smoothly in time. The systematic errors functions, ambiguities and station coordinates, are estimated simultaneously. As a result, the ambiguities and the station coordinates are estimated with better reliability and accuracy than the conventional least square method.

A new way of analyzing occlusion 3 dimensionally

This article introduces a new method for 3-dimensional dental cast analysis, by using a mechanical 3-dimensional digitizer, MicroScribe 3DX (Immersion, San Jose, Calif), and TIGARO software (not yet released, but available from the author at hayasaki@dent.kyushu-u.ac.jp). By digitizing points on the model, multiple measurements can be made, including tooth dimensions; arch length, width, and perimeter; curve of Spee; overjet and overbite; and anteroposterior discrepancy. The bias of the system can be evaluated by comparing the distance between 2 points as determined by the new system and as measured with digital calipers. Fifteen pairs of models were measured digitally and manually, and the bias was evaluated by comparing the variances of both methods and checking for the type of error obtained by each method. No systematic errors were found. The results showed that the method is accurate, and it can be applied to both clinical practice and research. Copyright © 2005 by the American Association of Orthodontists.

Temporal evolution of sulfated zirconia sol-gel during dip coating: Analysis of mass drainage with time-varying refractive index

The formation of sulfated zirconia films from a sol-gel derived aqueous suspension is subjected to double-optical monitoring during batch dip coating. Interpretation of interferometric patterns, previously obscured by a variable refractive index, is now made possible by addition of its direct measurement by a polarimetric technique in real time. Significant sensitivity of the resulting physical thickness and refractive index curves (uncertainties of ±7 nm and ±0.005, respectively) to temporal film evolution is shown under different withdrawal speeds. As a first contribution to quantitative understanding of temporal film formation with varying nanostructure during dip coating, detailed analysis is directed to the stage of the process dominated by mass drainage, whose simple modeling with temporal t-1/2 dependence is verified experimentally. © 2006 Elsevier B.V. All rights reserved.

Mitigating systematic errors for single frequency GPS receivers employing a penalized least squares methodology

Among the positioning systems that compose GNSS (Global Navigation Satellite System), GPS has the capability of providing low, medium and high precision positioning data. However, GPS observables may be subject to many different types of errors. These systematic errors can degrade the accuracy of the positioning provided by GPS. These errors are mainly related to GPS satellite orbits, multipath, and atmospheric effects. In order to mitigate these errors, a semiparametric model and the penalized least squares technique were employed in this study. This is similar to changing the stochastical model, in which error functions are incorporated and the results are similar to those in which the functional model is changed instead. Using this method, it was shown that ambiguities and the estimation of station coordinates were more reliable and accurate than when employing a conventional least squares methodology.

Modifying the stochastic model to mitigate GPS systematic errors in relative positioning

The GPS observables are subject to several errors. Among them, the systematic ones have great impact, because they degrade the accuracy of the accomplished positioning. These errors are those related, mainly, to GPS satellites orbits, multipath and atmospheric effects. Lately, a method has been suggested to mitigate these errors: the semiparametric model and the penalised least squares technique (PLS). In this method, the errors are modeled as functions varying smoothly in time. It is like to change the stochastic model, in which the errors functions are incorporated, the results obtained are similar to those in which the functional model is changed. As a result, the ambiguities and the station coordinates are estimated with better reliability and accuracy than the conventional least square method (CLS). In general, the solution requires a shorter data interval, minimizing costs. The method performance was analyzed in two experiments, using data from single frequency receivers. The first one was accomplished with a short baseline, where the main error was the multipath. In the second experiment, a baseline of 102 km was used. In this case, the predominant errors were due to the ionosphere and troposphere refraction. In the first experiment, using 5 minutes of data collection, the largest coordinates discrepancies in relation to the ground truth reached 1.6 cm and 3.3 cm in h coordinate for PLS and the CLS, respectively, in the second one, also using 5 minutes of data, the discrepancies were 27 cm in h for the PLS and 175 cm in h for the CLS. In these tests, it was also possible to verify a considerable improvement in the ambiguities resolution using the PLS in relation to the CLS, with a reduced data collection time interval. © Springer-Verlag Berlin Heidelberg 2007.

Antimony glasses with large nonlinear refractive indices, small two-photon absorption coefficients and ultrafast response at telecom wavelengths

Nonlinear (NL) optical properties of antimony oxide based glasses (AG) were characterized for excitation wavelengths from 800 to 1600 m. The NL refractive indices, n2, and the two-photon absorption (TPA) coefficient, β, have been evaluated using the Z-scan technique. Values of n2≈ 10-15 - 10-14 cm2/W of electronic origin were measured and negligible TPA coefficients (β < 0.003 cm/GW) were determined. The response time of the nonlinearity is faster than 100 fs as determined using the Kerr shutter technique. The figure-of-merit usually considered for all-optical switching, T = 2βλ/n2 , indicates that AG are very good materials for ultrafast switches at telecom wavelengths. © 2007 IEEE.

Modeling approach based on experimental results for prediction of measurement errors in energy meters

This paper presents a general modeling approach to investigate and to predict measurement errors in active energy meters both induction and electronic types. The measurement error modeling is based on Generalized Additive Model (GAM), Ridge Regression method and experimental results of meter provided by a measurement system. The measurement system provides a database of 26 pairs of test waveforms captured in a real electrical distribution system, with different load characteristics (industrial, commercial, agricultural, and residential), covering different harmonic distortions, and balanced and unbalanced voltage conditions. In order to illustrate the proposed approach, the measurement error models are discussed and several results, which are derived from experimental tests, are presented in the form of three-dimensional graphs, and generalized as error equations. © 2009 IEEE.

Importance of xenarthrans in the eco-epidemiology of Paracoccidioides brasiliensis

Background. Several pathogens that cause important zoonotic diseases have been frequently associated with armadillos and other xenarthrans. This mammal group typically has evolved on the South American continent and many of its extant species are seriously threatened with extinction. Natural infection of armadillos with Paracoccidioides brasiliensis in hyperendemic areas has provided a valuable opportunity for understanding the role of this mammal in the eco-epidemiology of Paracoccidioidomycosis (PCM), one of the most important systemic mycoses in Latin America. Findings. This study aimed to detect P. brasiliensis in different xenarthran species (Dasypus novemcinctus, Cabassous spp., Euphractus sexcinctus, Tamandua tetradactyla and Myrmecophaga tridactyla), by molecular and mycological approaches, in samples obtained by one of the following strategies: i) from road-killed animals (n = 6); ii) from naturally dead animals (n = 8); iii) from animals that died in captivity (n = 9); and iv) from living animals captured from the wild (n = 2). Specific P. brasiliensis DNA was detected in several organs among 7/20 nine-banded armadillos (D. novemcinctus) and in 2/2 anteaters (M. tridactyla). The fungus was also cultured in tissue samples from one of two armadillos captured from the wild. Conclusion. Members of the Xenarthra Order, especially armadillos, have some characteristics, including a weak cellular immune response and low body temperature, which make them suitable models for studying host-pathogen interaction. P. brasiliensis infection in wild animals, from PCM endemic areas, may be more common than initially postulated and reinforces the use of these animals as sentinels for the pathogen in the environment. © 2009 Bagagli et al; licensee BioMed Central Ltd.

Late-onset sepsis: Epidemiology, evaluation, and outcome

Late-onset neonatal sepsis is a common serious problem in preterm infants in neonatal intensive care units. Diagnosis can be difficult because clinical manifestations are not specific and none of the available laboratory tests can be considered an ideal marker. For this reason, a combination of markers has been proposed. Complete blood count and acute-phase reactants evaluated together help in diagnosis. C-reactive protein is a specific but late marker, and procalcitonin has proven accurate, although it is little studied in newborns. Blood, cerebrospinal fluid, and urine cultures always should be obtained when late-onset sepsis is suspected. Blood culture, the gold standard in diagnosis, is highly sensitive but needs up to 48 hours to detect microbial growth. Various cytokines have been investigated as early markers of infection, but results are not uniform. Other diagnostic tests that offer promise include: neutrophil surface markers, granulocyte colony-stimulating factor, toll-like receptors, and nuclear factor kappa B. The greatest hope for quick and accurate diagnosis lies in molecular biology, using real time polymerase chain reaction combined withDNAmicroarray. Sepsis and meningitis may affect both the short- and long-term prognosis for newborns. Mortality in neonatal meningitis has been reduced in recent years, but short-term complications and later neurocognitive sequelae remain. Late-onset sepsis significantly increases preterm infant mortality and the risk of cerebral lesions and neurosensory sequelae, including developmental difficulties and cerebral palsy. Early diagnosis of late-onset sepsis contributes to improved neonatal prognosis, but the outcome remains far from satisfactory. © 2010 by the American Academy of Pediatrics.

Epidemiology of vampire bat-transmitted rabies virus in Goiaαs, central Brazil: Re-evaluation based on G-L intergenic region

Background. Vampire bat related rabies harms both livestock industry and public health sector in central Brazil. The geographical distributions of vampire bat-transmitted rabies virus variants are delimited by mountain chains. These findings were elucidated by analyzing a high conserved nucleoprotein gene. This study aims to elucidate the detailed epidemiological characters of vampire bat-transmitted rabies virus by phylogenetic methods based on 619-nt sequence including unconserved G-L intergenic region. Findings. The vampire bat-transmitted rabies virus isolates divided into 8 phylogenetic lineages in the previous nucleoprotein gene analysis were divided into 10 phylogenetic lineages with significant bootstrap values. The distributions of most variants were reconfirmed to be delimited by mountain chains. Furthermore, variants in undulating areas have narrow distributions and are apparently separated by mountain ridges. Conclusions. This study demonstrates that the 619-nt sequence including G-L intergenic region is more useful for a state-level phylogenetic analysis of rabies virus than the partial nucleoprotein gene, and simultaneously that the distribution of vampire bat-transmitted RABV variants tends to be separated not only by mountain chains but also by mountain ridges, thus suggesting that the diversity of vampire bat-transmitted RABV variants was delimited by geographical undulations. © 2010 Itou et al; licensee BioMed Central Ltd.

Evaluation of electrical conductivity, pH and refractive index as physico-chemical parameters for quality control of Aveloz homeopathic solutions

Euphorbia tirucalli Lineu (Aveloz) belongs to the family Euphorbiaceae and is used in the treatment of cancer and warts. Some studies have reported that phorbol esters are the active principles responsible for the antitumor activity of Aveloz. The production of these molecules occurs in greater quantity in May, during the morning. This study aimed to evaluate whether the physico-chemical parameters of Aveloz homeopathic aqueous solutions such as pH, electrical conductivity and refractive index change due to storage time. Such parameters were measured regularly for 180 days. All solutions were prepared according to the method of grinding with lactose and subsequent dissolution in aqueous medium, as described in the Brazilian Homeopathic Pharmacopoeia, using as starting point the Aveloz latex collected in May. Homeopathic aqueous solutions containing only lactose were also prepared and evaluated as a control group. The potencies that were analyzed for electrical conductivity, pH and refractive index were: 4cH, 7cH, 9cH, 12cH, 14cH, 15cH, 29cH, 30cH. As a result, we found out that there was only statistical difference (p=0.035) in electrical conductivity between the homeopathic solutions containing Aveloz and the homeopathic solutions without Aveloz, when 15cH potency was compared. We also observed that the electrical conductivity increased with the aging of the solutions but is not directly related to the pH or the refractive index of the solutions, indicating that the aging process may alter the electrical conductivity of the homeopathic medicines. The presence of gas inside the glass that stores these solutions may affect the electrical conductivity measurements. Finally, no statistically significant difference was observed (p> 0.05) in the pH and refractive index.

Tamanho de amostra e estimativa de custo em levantamento epidemiológico de cárie dentária

This study aimed to analyze how the prevalence and the distribution of dental caries influence the sample size in epidemiological surveys, and how much are the costs. Secondary data of oral health surveys in 12-year-old schoolchildren from Bauru in 1976, 1984, 1990, 1994, and 2001, and from Piracicaba in 2001 and 2005 were studied. Sample sizes were estimated taking into account the mean DMFT and standard deviation of each survey, establishing sampling errors of 1%, 2%, 5%, and 10%. Costs were estimated considering permanent material, consumption material and human resources. The sample size in both towns needed to be increased, ranging from 119 in 1976 to 1,118 in 2001 in Bauru, and from 954 in 2001 to 1,252 in 2005 in Piracicaba, when a sampling error of 10% was considered. The cost of dental caries surveys was verified considering different sampling errors. This cost depends on how acceptable is the margin of difference between the true mean and the one found in the survey. In conclusion, the reduction in the prevalence of dental caries has determined the need for increase in sample size and in costs for conducting the surveys.

Relevance of Chinese goose (Anser cygnoides) in experimental epidemiology of Newcastle disease

This study aimed to characterize the true epidemiological role played by the Chinese goose (Anser cygnoides) as a potential source of infection by the Newcastle disease virus (NDV). For this, Specific-Pathogen-Free chicks (SPF) were used and were housed with Chinese geese that had been inoculated with a pathogenic strain (velogenic viscerotropic, strain São João do Meriti) of NDV (DIE50=108.15/0.1 mL) pathogenic to chickens, by the ocular-nasal route. Each group was composed of 6 SPF Leghorn chicks and 3 geese. At 6 days (Group I) and 14 days (Group II) after inoculation of the Chinese geese with NDV, SPF chicks were put into direct contact with each goose group. Cloacal swabs were collected from both species (Chinese geese and SPF chicks) 6, 10 and 20 days after challenge to genome viral excretion by Reverse Transcription Polymerase Chain Reaction (RT-PCR). Chinese geese did not demonstrate any clinical signs of Newcastle disease (ND). They were refractory to the clinical disease with the NDV. However, NDV genome was detected 20 days after challenge. Therefore, NDV carrier status was demonstrated by Chinese geese. Moreover, 100% of SPF chicks housed with the infected Chinese geese had died by 6 (Group I) and 14 days (Group II) after challenge. Thus, the transmission of the pathogenic virus from the Chinese geese to cohabiting SPF chicks was evident within 20 days of the experimental infection. This reveals the epidemiological importance of Chinese geese as a potential transmitter of NDV infection to other commercial birds that could be raised in close proximity.

Relevance of lovebirds (Agapornis roseicollis Selby, 1836) in experimental epidemiology of Newcastle disease

Studies were made to clarify the role that was played by the lovebirds (Agapornis roseicollis) in the epidemiological plan, under the perspective of its being a potential source of infection of Newcastle Disease Virus (NDV). The study used Specific-Pathogen-Free chicks (SPF) that were housed with lovebirds inoculated with a pathogenic strain (velogenic viscerotropic) of NDV pathogenic to chickens, by the ocular-nasal via. Each group was composed of six SPF chicks and four lovebirds. After five days of the inoculation of the lovebirds with NDV, SPF chicks were put together with each group of lovebirds. Cloacae swabs were collected after 9, 14 and 21 days post-challenge in both species (lovebirds and SPF chicks) for genome viral excretion by Reverse Transcription Polymerase Chain Reaction (RT-PCR). Lovebirds did not demonstrate any clinical signs of NDV. They were refractory to the clinical disease with the NDV. However, NDV genome was detected 9 and 21 days after challenge. This study shows that lovebirds can be carriers NDV. Moreover, 100% of SPF chicks allocated with the infected lovebirds demonstrated clinical signs and lesions suggestive of NDV. In these birds, NDV genome was detected 9, 14 and 21 days after challenge. Thus, the transmission of the pathogenic virus from the lovebirds to SPF chicks that were housed together was evident until 21 days of the experimental infection. This study reveals the importance of lovebirds from the epidemiological point of view as potential source of infection of the NDV to other avian species that could be raised near this species. © Asian Network for Scientific Information, 2012.