45 resultados para open loop rectangular resonator (OLRR)
Resumo:
What is the importance of open habitat in a predominantly closed forest to the dung beetle assemblage? The Atlantic Forest in Brazil is one of the most highly disturbed ecosystems and is mainly represented by fragmented areas. However, in places where human disturbances have ceased, certain areas are showing a natural regeneration pattern. The aim of the present study was to determine how the dung beetle assemblage responds to distinct habitat structures in a fragment of Atlantic Forest. For such, open and closed forest areas were sampled in a fragment of the Atlantic Forest in the northeastern region of Brazil. Pitfall traps baited with excrement and carrion were used to collect the beetles. A total of 7,267 individuals belonging to 35 species were captured. Canthon chalybaeus and C. mutabilis were restricted to open areas. Nearly 90% of the individuals of C. aff. simulans and Deltochilum aff. irroratum were identified in these areas. A higher percentage (> 50%) of Canthon staigi, Dichotomius aff. depressicolis and D. aff. sericeus occurred in closed areas. Abundance differed between areas, with higher values in closed areas. Richness was not influenced by the habitat structure. NMDS ordination exhibited the segregation of areas and ANOSIM confirmed that this variable explained the assemblage of dung beetle species. The findings of the present study validate that open areas are associated to more restrictive conditions, limiting a higher abundance of dung beetle. Although situated near preserved fragments, the studied open areas increase the heterogeneity of the general landscape.
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The quantification of ammonia (NH3) losses from sugarcane straw fertilized with urea can be performed with collectors that recover the NH3 in acid-treated absorbers. Thus, the use of an open NH3 collector with a polytetrafluoroethylene (PTFE)-wrapped absorber is an interesting option since its cost is low, handling easy and microclimatic conditions irrelevant. The aim of this study was to evaluate the efficiency of an open collector for quantifying NH3-N volatilized from urea applied over the sugarcane straw. The experiment was carried out in a sugarcane field located near Piracicaba, São Paulo, Brazil. The NH3-N losses were estimated using a semi-open static collector calibrated with 15N (reference method) and an open collector with an absorber wrapped in PTFE film. Urea was applied to the soil surface in treatments corresponding to rates of 50, 100, 150 and 200 kg ha-1 N. Applying urea-N fertilizer on sugarcane straw resulted in losses NH3-N up to 24 % of the applied rate. The amount of volatile NH3-N measured in the open and the semi-open static collector did not differ. The effectiveness of the collection system varied non-linearly, with an average value of 58.4 % for the range of 100 to 200 kg ha-1 of urea-N. The open collector showed significant potential for use; however, further research is needed to verify the suitability of the proposed method.
Resumo:
A comunicação científica ampliou seus horizontes de troca de dados, informações e conhecimentos com o aparecimento dos open archives, arquivos que congregam e-prints das diversas áreas do saber e que são abertos à consulta pública, bem como à publicação automatizada dos trabalhos por parte dos pesquisadores. A experiência americana em áreas da física, matemática e ciência da computação, entre outras, demonstra a viabilidade e utilidade dos arquivos abertos como ponto de convergência para comunidades de pesquisadores que se vêem sem fronteiras geográficas ou institucionais para o intercâmbio de seus resultados de pesquisas.
Resumo:
The author reviews past work with Ibict and the global progress made by the Open Access Movement. He postulates a theory of open access being an example of a complex adaptive system created by Internet-based scholarly publishing. Open access could be the cause of a cascade of increasing complexity and opportunities that will reshape this system. He has chosen the pervasive and global "Connectedness" created by the internet and the content spaces it provides for open access collections as a "simple disruptive agent". He discusses how connectedness influences infinite variety, creativity, work, change, knowledge, and the information economy. Case studies from the University of New Mexico Libraries are used where appropriate.
Resumo:
Worldwide initiatives toward digital library (DL) support for electronic theses and dissertations (ETDs), facilitated by the work of the Networked Digital Library of Theses and Dissertations (NDLTD), are a key part of the move toward open access. When all graduate students learn to use openly available ETDs, and have experience with authoring and submission in connection with their own research results, it will be easy for them to continue these efforts through other contributions to open access. When all universities support ETD activities, they will be key participants in institutional repositories and open access, and will have engaged in discussion and infrastructure development supportive of further open access activities. Understanding of open access also can be facilitated through modeling of all of these efforts using the 5S framework, considering the key aspects of DL development: Societies, Scenarios, Spaces, Structures, and Streams.
Resumo:
This paper describes a project led by the Instituto Brasileiro de Informações em Ciência e Tecnologia (Ibict), a government institution, to build a national digital library for electronic theses and dissertations - Bibliteca Digital de Teses e Dissertações (BDTD). The project has been a collaborative effort among Ibict, universities and other research centers in Brazil. The developers adopted a system architecture based on the Open Archives Initiative (OAI) in which universities and research centers act as data providers and Ibict as a service provider. A Brazilian metadata standard for electronic theses and dissertations was developed for the digital library. A toolkit including open source package was also developed by Ibict to be distributed to potential data providers. BDTD has been integrated with the international initiative: the Networked Digital Library of Thesis and Dissertation (NDLTD). Discussions in the paper address various issues related to project design, development and management as well as the role played by Ibict. Conclusions highlight some important lessons learned to date and challenges for the future in expanding the BDTD project.
Resumo:
The objetive of this work was to evaluate the influence of intergenotypic competition in open-pollinated families of Eucalyptus and its effects on early selection efficiency. Two experiments were carried out, in which the timber volume was evaluated at three ages, in a randomized complete block design. Data from the three years of evaluation (experiment 1, at 2, 4, and 7 years; and experiment 2, at 2, 5, and 7 years) were analyzed using mixed models. The following were estimated: variance components, genetic parameters, selection gains, effective number, early selection efficiency, selection gain per unit time, and coincidence of selection with and without the use of competition covariates. Competition effect was nonsignificant for ages under three years, and adjustment using competition covariates was unnecessary. Early selection for families is effective; families that have a late growth spurt are more vulnerable to competition, which markedly impairs ranking at the end of the cycle. Early selection is efficient according to all adopted criteria, and the age of around three years is the most recommended, given the high efficiency and accuracy rate in the indication of trees and families. The addition of competition covariates at the end of the cycle improves early selection efficiency for almost all studied criteria.
Resumo:
An important component for the automation of flow injection analysis (FIA) systems is the sample injection valve. A simple and inexpensive commutator with 16 pinch valves (8 normally open and 8 closed) was developed and configured as a multichannel injection valve. It is activated by a single solenoid of 3 Kgf, powered by a pulsed driver circuit, controlled by a microcomputer or a switch. FIA with spectrophometric detection of potassium dichromate solution was used for the evaluation of the new injection valve and its comparison with other valves, for sample loops of 50, 100, 200, 300 and 500 muL. The repeatability was favorable (RSD 1.0% for 15 injections at each loop volume) compared to a manual injector, an electropneumatic injector and an injector configured with three mini solenoid valves (RSD 1.1, 1.3 and 1.0%, respectively, for15 injections at each loop volume).
Resumo:
QSAR modeling is a novel computer program developed to generate and validate QSAR or QSPR (quantitative structure- activity or property relationships) models. With QSAR modeling, users can build partial least squares (PLS) regression models, perform variable selection with the ordered predictors selection (OPS) algorithm, and validate models by using y-randomization and leave-N-out cross validation. An additional new feature is outlier detection carried out by simultaneous comparison of sample leverage with the respective Studentized residuals. The program was developed using Java version 6, and runs on any operating system that supports Java Runtime Environment version 6. The use of the program is illustrated. This program is available for download at lqta.iqm.unicamp.br.
LOW COST ANALYZER FOR THE DETERMINATION OF PHOSPHORUS BASED ON OPEN-SOURCE HARDWARE AND PULSED FLOWS
Resumo:
The need for automated analyzers for industrial and environmental samples has triggered the research for new and cost-effective strategies of automation and control of analytical systems. The widespread availability of open-source hardware together with novel analytical methods based on pulsed flows have opened the possibility of implementing standalone automated analytical systems at low cost. Among the areas that can benefit from this approach are the analysis of industrial products and effluents and environmental analysis. In this work, a multi-pumping flow system is proposed for the determination of phosphorus in effluents and polluted water samples. The system employs photometric detection based on the formation of molybdovanadophosphoric acid, and the fluidic circuit is built using three solenoid micropumps. The detection is implemented with a low cost LED-photodiode photometric detection system and the whole system is controlled by an open-source Arduino Uno microcontroller board. The optimization of the timing to ensure the color development and the pumping cycle is discussed for the proposed implementation. Experimental results to evaluate the system behavior are presented verifying a linear relationship between the relative absorbance and the phosphorus concentrations for levels as high as 50 mg L-1.
Resumo:
The present study shows the development, simulation and actual implementation of a closed-loop controller based on fuzzy logic that is able to regulate and standardize the mass flow of a helical fertilizer applicator. The control algorithm was developed using MATLAB's Fuzzy Logic Toolbox. Both open and closed-loop simulations of the controller were performed in MATLAB's Simulink environment. The instantaneous deviation of the mass flow from the set point (SP), its derivative, the equipment´s translation velocity and acceleration were all used as input signals for the controller, whereas the voltage of the applicator's DC electric motor (DCEM) was driven by the controller as output signal. Calibration and validation of the rules and membership functions of the fuzzy logic were accomplished in the computer simulation phase, taking into account the system's response to SP changes. The mass flow variation coefficient, measured in experimental tests, ranged from 6.32 to 13.18%. The steady state error fell between -0.72 and 0.13g s-1 and the recorded average rise time of the system was 0.38 s. The implemented controller was able to both damp the oscillations in mass flow that are characteristic of helical fertilizer applicators, and to effectively respond to SP variations.
Resumo:
The Bartlett-Lewis Rectangular Pulse Modified (BLPRM) model simulates the precipitous slide in the hourly and sub-hourly and has six parameters for each of the twelve months of the year. This study aimed to evaluate the behavior of precipitation series in the duration of 15 min, obtained by simulation using the model BLPRM in situations: (a) where the parameters are estimated from a combination of statistics, creating five different sets; (b) suitability of the model to generate rain. To adjust the parameters were used rain gauge records of Pelotas/RS/Brazil, which statistics were estimated - mean, variance, covariance, autocorrelation coefficient of lag 1, the proportion of dry days in the period considered. The results showed that the parameters related to the time of onset of precipitation (λ) and intensities (μx) were the most stable and the most unstable were ν parameter, related to rain duration. The BLPRM model adequately represented the mean, variance, and proportion of the dry period of the series of precipitation lasting 15 min and, the time dependence of the heights of rain, represented autocorrelation coefficient of the first retardation was statistically less simulated series suitability for the duration of 15 min.
Resumo:
OBJECTIVE: to evaluate the outcome of abdominal wall integrity of both techniques. METHODS: a retrospective study was carried out at the Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, identifying the patients undergoing temporary abdominal closure (TAC) from January 2005 to December 2011. Data were collected through the review of clinical charts. Inclusion criteria were indication of TAC and survival to definitive abdominal closure. In the post-operative period only a group of three surgeons followed all patients and performed the reoperations. RESULTS: Twenty eightpatients were included. The difference in primary closure rates and mean time for fascial closure did not reach statistical significance (p=0.98 and p=0.23, respectively). CONCLUSION: VAC and Bogota Bag do not differ significantly regarding the outcome of abdominal wall integrity, due to the monitoring of a specific team and the adoption of progressive closure
Comparison between open and laparoscopic elective cholecystectomy in elderly, in a teaching hospital
Resumo:
Objective: to analyze the differences in mortality rates, length of hospital stay, time of surgery and the conversion rate between elective open cholecystectomies (OC) and laparoscopic ones (LC) in elderly patients. Methods : we evaluated medical records of patients 65 years of age or older undergoing open or laparoscopic cholecystectomy at the Hospital Regional de Mato Grosso do Sul between January 2008 and December 2011. We excluded individuals operated in non-elective scenarios or who underwent intraoperative cholangiography. Results : we studied 113 patients, of whom 38.1% were submitted to the OC and 61.9%, to LC. Women accounted for 69% of patients and men, for 31%. The conversion rate was 2.9%. The mean age and duration of the procudure was 70.1 and 84 minutes, respectively, with no significant difference between OC and LC. Patients undergoing LC had shorter hospital stays (2.01 versus 2.95 days, p=0.0001). We identified operative complications in sixpatients (14%) after OC and in nine (12%) after LC, with no statistical difference. Conclusion : there was no difference in morbidity and mortality when comparing OC with LC. The laparoscopic approach led to shorter hospital stay. Operative time did not differ between the two access routes. The conversion rate was similar to other studies.
Resumo:
Objective: to investigate the effects of preoperative fasting abbreviation with oral supplementation with carbohydrate in the evolution of grip strength in patients undergoing cholecystectomy by laparotomy. Methods : we conducted a clinical, randomizeddouble blind study with adult female patients, aged 18-60 years. Patients were divided into two groups: Control Group, with fasting prescription 6-8h until the time of operation; and Intervention Group, which received prescription of fasting for solids 6-8h before surgery, but ingested an oral supplement containing 12.5% carbohydrate, six (400ml) and two (200ml) hours before theprocedure. The handgrip strength was measured in both hands in both groups, at patient's admission (6h before surgery), the immediate pre-operative time (1h before surgery) and 12-18h postoperatively. Results : we analyzed 27 patients, 14 in the intervention group and 13 in the control group. There was no mortality. The handgrip strength (mean [standard deviation]) was significantly higher in the intervention group in the three periods studied, in at least one hand: preoperatively in the dominant hand (27.8 [2.6] vs 24.1 [3.7] kg; p=0.04), in the immediate preoperative in both hands, and postoperatively in the non-dominant hand (28.5 [3.0] vs 21.3 [5.9] kg; p=0.01). Conclusion : the abbreviation of preoperative fasting to two hours with drink containing carbohydrate improves muscle function in the perioperative period.