947 resultados para entomological evaluation techniques
Resumo:
This study aimed to describe the behavior of oviposition traps for Aedes aegypti over time, to compare it with the larval survey and to investigate the association with climatic variables. It was conducted in So Jos do Rio Preto city, So Paulo. Daily climatic data and fortnightly measurements for oviposition traps and larval infestation were collected from October 2003 to September 2004. Three different periods were identified in the behavior of oviposition traps' positivity and mean number of eggs: increase, plateau and decrease in values. These measurements followed the variation of climatic data from the first and third periods. High correlation was obtained between the positivity and the mean number of eggs. The oviposition traps showed higher capacity to detect the vector than did larval survey. It was observed that the first (October to December) and third (May to September) periods were considered to be the most suitable to use oviposition traps than larval surveys.
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The non-invasive evaluation of myocardial ischemia is a priority in cardiology. The preferred initial non-invasive test is exercise ECG, because of its high accessibility and its low cost. Stress radionuclide myocardial perfusion imaging or stress echocardiography are now routinely performed, and new non-invasive techniques such as perfusion-MRI, dobutamine stress-MRI or 82rubidium perfusion PET have recently gained acceptance in clinical practice. In the same time, an increasing attention has been accorded to the concept of myocardial viability in the decisional processes in case of ischemic heart failure. In this indication, MRI with late enhancement after intravenous injection of gadolinium and 18F-FDG PET showed an excellent diagnostic accuracy. This article will present these new imaging modalities and their accepted indications.
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The effects of diethylenetriaminpenta(methylenephosphonic acid) (DTPMP), a phosphonate inhibitor, on the growth of delayed ettringite have been evaluated using concrete in highway US 20 near Williams, Iowa, and the cores of six highways subject to moderate (built in 1992) or minor (built in 1997) deterioration. Application of 0.01 and 0.1 vol. % DTPMP to cores was made on a weekly or monthly basis for one year under controlled laboratory-based freeze-thaw and wet-dry conditions over a temperature range of -15 degrees to 58 degrees C to mimic extremes in Iowa roadway conditions. The same concentrations of phosphonate were also applied to cores left outside (roof of Science I at Iowa State University) over the same period of time. Nineteen applications of 0.1 vol. % DTPMP with added deicing salt solution (about 23 weight % NACL) were made to US 20 during the winters of 2003 and 2004. In untreated samples, air voids, pores, and occasional cracks are lined with acicular ettringite crystals (up to 50 micrometers in length) whereas air voids, pores, and cracks in concrete from the westbound lane of US 20 are devoid of ettringite up to a depth of about 0.5 mm from the surface of the concrete. Ettringite is also absent in zones up to 6 mm from the surface of concrete slabs placed on the roof of Science I and cores subject to laboratory-based freeze-thaw experiments. In these zones, the relatively high concentration of DTPMP caused it to behave as a chelator. Stunted ettringite crystals 5 to 25 micrometers in length, occasionally coated with porlandite, form on the margins of these zones indicating that in these areas DTPMP behaved as an inhibitor due to a reduction in the concentration of phosphonate. Analyses of mixes of ettringite and DTPMP using electrospray mass spectrometry suggests that the stunting of ettringite growth is caused by the adsorption of a Ca2+ ion and a water molecule to deprotonated DTPMP on the surface of the {0001} face of ettringite. It is anticipated that by using a DTPMP concentration of between 0.001 and 0.01 vol. % for the extended life of a highway (i.e. >20 years), deterioration caused by the expansive growth of ettringite will be markedly reduced.
Resumo:
The objective of this work was to evaluate the accuracy of digestion techniques using nitric and perchloric acid at the ratios of 2:1, 3:1, and 4:1 v v-1, in one- or two-step digestion, to estimate chromium contents in cattle feces, using sodium molybdate as a catalyst. Fecal standards containing known chromium contents (0, 2, 4, 6, 8, and 10 g kg-1) were produced from feces of five animals. The chromium content in cattle feces is accurately estimated using digestion techniques based on nitric and perchloric acids, at a 3:1 v v-1 ratio, in one-step digestion, with sodium molybdate as a catalyst.
Resumo:
The potential for enhancing the energy efficiency of industrial pumping processes is estimated to be in some cases up to 50 %. One way to define further this potential is to implement techniques in accordance to definition of best available techniques in pumping applications. These techniques are divided into three main categories: Design, control method & maintenance and distribution system. In the theory part of this thesis first the definition of best available techniques (BAT) and its applicability on pumping processes is issued. Next, the theory around pumping with different pump types is handled, the main stress being in centrifugal pumps. Other components needed in a pumping process are dealt by presenting different control methods, use of an electric motor, variable speed drive and the distribution system. Last part of the theory is about industrial pumping processes from water distribution, sewage water and power plant applications, some of which are used further on in the empirical part as example cases. For the empirical part of this study four case studies on typical pumping processes from older Masters these were selected. Firstly the original results were analyzed by studying the distribution of energy consumption between different system components and using the definition of BAT in pumping, possible ways to improve energy efficiency were evaluated. The goal in this study was that by the achieved results it would be possible to identify the characteristic energy consumption of these and similar pumping processes. Through this data it would then be easier to focus energy efficiency actions where they might be the most applicable, both technically and economically.
Resumo:
This work presents the implementation and comparison of three different techniques of three-dimensional computer vision as follows: • Stereo vision - correlation between two 2D images • Sensorial fusion - use of different sensors: camera 2D + ultrasound sensor (1D); • Structured light The computer vision techniques herein presented took into consideration the following characteristics: • Computational effort ( elapsed time for obtain the 3D information); • Influence of environmental conditions (noise due to a non uniform lighting, overlighting and shades); • The cost of the infrastructure for each technique; • Analysis of uncertainties, precision and accuracy. The option of using the Matlab software, version 5.1, for algorithm implementation of the three techniques was due to the simplicity of their commands, programming and debugging. Besides, this software is well known and used by the academic community, allowing the results of this work to be obtained and verified. Examples of three-dimensional vision applied to robotic assembling tasks ("pick-and-place") are presented.
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Methods previously described by Canovai et al. (Caryologia 47: 241-247, 1994) which produced C and ASG bands in mitotic chromosomes of Ceratitis capitata were applied to the chromosomes of several Anastrepha species. Metaphase plate yield was substantially increased by use of imaginal disks together with cerebral ganglia. The C-bands were quite prominent allowing the resolution of tiny blocks of heterochromatin. The ASG method produced G-like banded chromosomes, which permitted recognition of each individual chromosome. These simple techniques do not require special equipment and may be valuable for karyotype variability studies in fruit flies and other Diptera
Resumo:
This paper was designed to evaluate the rancidity of 18 pet food samples using the Diamed FATS kits and official AOCS methods for the quantification of free fatty acids, peroxide value and concentrations of malonaldehyde and alkenal in the lipid extracted. Although expiration dates have passed, the samples presented good quality evidencing little oxidative rancidity. The results of this study suggest that the Brazilian pet food market is replete with products of excellent quality due to the competitiveness of this market sector.
Resumo:
Keyphrases are added to documents to help identify the areas of interest they contain. However, in a significant proportion of papers author selected keyphrases are not appropriate for the document they accompany: for instance, they can be classificatory rather than explanatory, or they are not updated when the focus of the paper changes. As such, automated methods for improving the use of keyphrases are needed, and various methods have been published. However, each method was evaluated using a different corpus, typically one relevant to the field of study of the methods authors. This not only makes it difficult to incorporate the useful elements of algorithms in future work, but also makes comparing the results of each method inefficient and ineffective. This paper describes the work undertaken to compare five methods across a common baseline of corpora. The methods chosen were Term Frequency, Inverse Document Frequency, the C-Value, the NC-Value, and a Synonym based approach. These methods were analysed to evaluate performance and quality of results, and to provide a future benchmark. It is shown that Term Frequency and Inverse Document Frequency were the best algorithms, with the Synonym approach following them. Following these findings, a study was undertaken into the value of using human evaluators to judge the outputs. The Synonym method was compared to the original author keyphrases of the Reuters News Corpus. The findings show that authors of Reuters news articles provide good keyphrases but that more often than not they do not provide any keyphrases.
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Hydrogels are polymeric materials used in many pharmaceutical and biomedical applications due to their ability to form 3D hydrophilic polymeric networks, which can absorb large amounts of water. In the present work, polyethylene glycols (PEG) were introduced into the hydrogel liquid phase in order to improve the mechanical properties of hydrogels composed of 2-hydroxyethylacrylate and 2-hydroxyethylmethacrylate (HEAHEMA) synthesized with different co-monomer compositions and equilibrated in water or in 20 % waterPEG 400 and 600 solutions. The thermoanalytical techniques [differential scanning calorimetry (DSC) and thermogravimetry (TG)] were used to evaluate the amount and properties of free and bound water in HEAHEMA hydrogels. The internal structure and the mechanical properties of hydrogels were studied using scanning electron microscopy and friability assay. TG loss-on-drying experiments were applied to study the water-retention properties of hydrogels, whereas the combination of TG and DSC allowed estimating the total amount of freezable and non-freezing water in hydrogels. The results show that the addition of viscous co-solvent (PEG) to the liquid medium results in significant improvement of the mechanical properties of HEAHEMA hydrogels and also slightly retards the water loss from the hydrogels. A redistribution of free and bound water in the hydrogels equilibrated in mixed solutions containing 20 vol% of PEGs takes place.
Resumo:
Soil organic matter (SOM) is one of the main global carbon pools. It is a measure of soil quality as its presence increases carbon sequestration and improves physical and chemical soil properties. The determination and characterisation of humic substances gives essential information of the maturity and stresses of soils as well as of their health. However, the determination of the exact nature and molecular structure of these substances has been proven difficult. Several complex techniques exist to characterise SOM and mineralisation and humification processes. One of the more widely accepted for its accuracy is nuclear magnetic resonance (NMR) spectroscopy. Despite its efficacy, NMR needs significant economic resources, equipment, material and time. Proxy measures like the fluorescence index (FI), cold and hot-water extractable carbon (CWC and HWC) and SUVA-254 have the potential to characterise SOM and, in combination, provide qualitative and quantitative data of SOM and its processes. Spanish and British agricultural cambisols were used to measure SOM quality and determine whether similarities were found between optical techniques and 1H NMR results in these two regions with contrasting climatic conditions. High correlations (p < 0.001) were found between the specific aromatic fraction measured with 1H NMR and SUVA-254 (Rs = 0.95) and HWC (Rs = 0.90), which could be described using a linear model. A high correlation between FI and the aromatics fraction measured with 1H NMR (Rs = 0.976) was also observed. In view of our results, optical measures have a potential, in combination, to predict the aromatic fraction of SOM without the need of expensive and time consuming techniques.
Resumo:
If a plastic material is used as a print bearer there are a need of a special surface treatment to get agod and durable printing. The most used surface treatment technique for the moment is coronatreatment. This kind of treatment has unfortunately showed not to be so durable in the long term.Plasma treatment which in this case uses different kind of gases in the treatment of polypropyleneis shown as a more effective treatment in this project. When the plasma treated surface has beenprinted is the good quality last much longer and the adhesion between the ink and the surface isremained. To test this adhesion is for the moment a standard used (ASTM D3359). This standardhas appeared unstable and dependent at many different factors, which gives a big variation in thetest results. Because of this has new test methods been carried out to give a more even and morereliable result in the test of the adhesion.
Resumo:
Purpose: The aim of this study was to compare 2 different methods of assessment of implants at different inclinations (90 degrees and 65 degrees)-with a profilometer and AutoCAD software. Materials and Methods: Impressions (n = 5) of a metal matrix containing 2 implants, 1 at 90 degrees to the surface and 1 at 65 degrees to the surface, were obtained with square impression copings joined together with dental floss splinting covered with autopolymerizing acrylic resin, an open custom tray, and vinyl polysiloxane impression material. Measurement of the angles (in degrees) of the implant analogs were assessed by the same blinded operator with a profilometer and through analysis of digitized images by AutoCAD software. For each implant analog, 3 readings were performed with each method. The results were subjected to a nonparametric Kruskal-Wallis test, with P <= .05 considered significant. Results: For implants perpendicular to the horizontal surface of the specimen (90 degrees), there were no significant differences between the mean measurements obtained with the profilometer (90.04 degrees) and AutoCAD (89.95 degrees; P=.9142). In the analyses of the angled implants at 65 degrees in relation to the horizontal surface of the specimen, significant differences were observed (P=.0472) between the mean readings with the profilometer (65.73 degrees) and AutoCAD (66.25 degrees). Conclusions: The degrees of accuracy of implant angulation recording vary among the techniques available and may vary depending on the angle of the implant. Further investigation is needed to determine the best test conditions and the best measuring technique for determination of the angle of the implant in vitro.