937 resultados para high efficiency


Relevância:

30.00% 30.00%

Publicador:

Resumo:

Studies on nutritional efficiency of phosphorus in conilon coffee plants are important tools to unravel the high limitation that natural low levels of this nutrient in soil impose to these species cultivars. Therefore, this study aimed at evaluating the nutritional efficiency and the response to phosphorus of conilon coffee clones. Plants were managed during 150 days in pots containing 10 dm³ of soil, in greenhouse. A factorial scheme 13 x 2 was used, with three replications, being the factors: 13 clones constituting the clonal cultivar "Vitória Incaper 8142" and two levels of phosphate fertilization (0% and 150% of the P2O5 usualy recommended), in a completely randomized design (CRD). The results indicate a differentiated response of dry matter production and of phosphorus content on each level of phosphate fertilization for the conilon coffee clones and that CV-04, CV-05 and CV-08 clones are nutritionally efficient and responsive to the phosphate fertilization.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

n plant breeding programs that aim to obtain cultivars with nitrogen (N) use efficiency, the focus is on methods of selection and experimental procedures that present low cost, fast response, high repeatability, and can be applied to a large number of cultivars. Thus, the objectives of this study were to classify maize cultivars regarding their use efficiency and response to N in a breeding program, and to validate the methodology with contrasting doses of the nutrient. The experimental design was a randomized block with the treatments arranged in a split-plot scheme with three replicates and five N doses (0, 30, 60, 120 and 200 kg ha-1) in the plots, and six cultivars in subplots. We compared a method examining the efficiency and response (ER) with two contrasting doses of N. After that, the analysis of variance, mean comparison and regression analysis were performed. In conclusion, the method of the use efficiency and response based on two N levels classifies the cultivars in the same way as the regression analysis, and it is appropriate in plant breeding routine. Thus, it is necessary to identify the levels of N required to discriminate maize cultivars in conditions of low and high N availability in plant breeding programs that aim to obtain efficient and responsive cultivars. Moreover, the analysis of the interaction genotype x environment at experiments with contrasting doses is always required, even when the interaction is not significant.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Titanium films have been deposited on stainless steel metal sheets using dc magnetron sputtering technique at different substrate temperatures. The structure of the titanium films strongly depend on the substrate temperature. The titanium film deposited at the substrate temperature lower than 300 ◦C has a loose flat sheet grains structure and the titanium film prepared at the substrate temperature higher than 500 ◦C has a dense nubby grains structure. The DSSC assembled using stainless steel sheet coated with titanium film deposited at high substrate temperature has a low charge transfer resistance in the TiO2/Ti interface and results in a high conversion efficiency. The DSSC assembled using stainless steel sheet coated with titanium film deposited at temperature higher than 500 ◦C has higher conversion efficiency than that assembled using titanium metal sheet as the substrate. The maximum conversion efficiency, 2.26% is obtained for DSSC assembled using stainless steel sheet coated with titanium film deposited at 700 ◦C substrate temperature, which is about 70% of the conversion efficiency of the FTO reference cell used in this study.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

A new high performance architecture for the computation of all the DCT operations adopted in the H.264/AVC and HEVC standards is proposed in this paper. Contrasting to other dedicated transform cores, the presented multi-standard transform architecture is supported on a completely configurable, scalable and unified structure, that is able to compute not only the forward and the inverse 8×8 and 4×4 integer DCTs and the 4×4 and 2×2 Hadamard transforms defined in the H.264/AVC standard, but also the 4×4, 8×8, 16×16 and 32×32 integer transforms adopted in HEVC. Experimental results obtained using a Xilinx Virtex-7 FPGA demonstrated the superior performance and hardware efficiency levels provided by the proposed structure, which outperforms its more prominent related designs by at least 1.8 times. When integrated in a multi-core embedded system, this architecture allows the computation, in real-time, of all the transforms mentioned above for resolutions as high as the 8k Ultra High Definition Television (UHDTV) (7680×4320 @ 30fps).

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The present paper describes a procedure to isolate volatiles from rock-rose (Cistus ladanifer L.) using simultaneous distillation–extraction (SDE). High-value volatile compounds (HVVC) were selected and the influence of the extraction conditions investigated. The effect of the solvent nature and extraction time on SDE efficiency was studied. The best performance was achieved with pentane in 1 h operation. The extraction efficiencies ranged from 65% to 85% and the repeatability varied between 4% and 6% (as a CV%). The C. ladanifer SDE extracts were analysed by headspace solid phase microextraction (HS-SPME) followed by gas chromatography with flame ionization detection (GC-FID). The HS-SPME sampling conditions such as fiber coating, temperature, ionic strength and exposure time were optimized. The best results were achieved with an 85 µm polyacrylate fiber for a 60 min headspace extraction at 40ºC with 20% (w/v) of NaCl. For optimized conditions the recovery was in average higher than 90% for all compounds and the intermediate precision ranged from 4 to 9% (as CV %). The volatiles α-pinene (22.2 mg g−1 of extract), 2,2,6-trimethylcyclohexanone (6.1 mg g−1 of extract), borneol (3.0 mg g−1 of extract) and bornyl acetate (3.9 mg g−1 of extract) were identified in the SDE extracts obtained from the fresh plant material.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

High risk of recurrence/progression bladder tumours is treated with Bacillus Calmette-Guérin (BCG) immunotherapy after complete resection of the tumour. Approximately 75% of these tumours express the uncommon carbohydrate antigen sialyl-Tn (Tn), a surrogate biomarker of tumour aggressiveness. Such changes in the glycosylation of cell-surface proteins influence tumour microenvironment and immune responses that may modulate treatment outcome and the course of disease. The aim of this work is to determine the efficiency of BCG immunotherapy against tumours expressing sTn and sTn-related antigen sialyl-6-T (s6T). METHODS: In a retrospective design, 94 tumours from patients treated with BCG were screened for sTn and s6T expression. In vitro studies were conducted to determine the interaction of BCG with high-grade bladder cancer cell line overexpressing sTn. RESULTS: From the 94 cases evaluated, 36 had recurrence after BCG treatment (38.3%). Treatment outcome was influenced by age over 65 years (HR=2.668; (1.344-5.254); P=0.005), maintenance schedule (HR=0.480; (0.246-0.936); P=0.031) and multifocality (HR=2.065; (1.033-4.126); P=0.040). sTn or s6T expression was associated with BCG response (P=0.024; P<0.0001) and with increased recurrence-free survival (P=0.001). Multivariate analyses showed that sTn and/or s6T were independent predictive markers of recurrence after BCG immunotherapy (HR=0.296; (0.148-0.594); P=0.001). In vitro studies demonstrated higher adhesion and internalisation of the bacillus to cells expressing sTn, promoting cell death. CONCLUSION: s6T is described for the first time in bladder tumours. Our data strongly suggest that BCG immunotherapy is efficient against sTn- and s6T-positive tumours. Furthermore, sTn and s6T expression are independent predictive markers of BCG treatment response and may be useful in the identification of patients who could benefit more from this immunotherapy.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

TiO2 nanorod films have been deposited on ITO substrates by dc reactive magnetron sputtering technique. The structures of these nanorod films were modified by the variation of the oxygen pressure during the sputtering process. Although all these TiO2 nanorod films deposited at different oxygen pressures show an anatase structure, the orientation of the nanorod films varies with the oxygen pressure. Only a very weak (101) diffraction peak can be observed for the TiO2 nanorod film prepared at low oxygen pressure. However, as the oxygen pressure is increased, the (220) diffraction peak appears and the intensity of this diffraction peak is increased with the oxygen pressure. The results of the SEM show that these TiO2 nanorods are perpendicular to the ITO substrate. At low oxygen pressure, these sputtered TiO2 nanorods stick together and have a dense structure. As the oxygen pressure is increased, these sputtered TiO2 nanorods get separated gradually and have a porous structure. The optical transmittance of these TiO2 nanorod films has been measured and then fitted by OJL model. The porosities of the TiO2 nanorod films have been calculated. The TiO2 nanorod film prepared at high oxygen pressure shows a high porosity. The dye-sensitized solar cells (DSSCs) have been assembled using these TiO2 nanorod films prepared at different oxygen pressures as photoelectrode. The optimum performance was achieved for the DSSC using the TiO2 nanorod film with the highest (220) diffraction peak and the highest porosity.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Feature selection is a central problem in machine learning and pattern recognition. On large datasets (in terms of dimension and/or number of instances), using search-based or wrapper techniques can be cornputationally prohibitive. Moreover, many filter methods based on relevance/redundancy assessment also take a prohibitively long time on high-dimensional. datasets. In this paper, we propose efficient unsupervised and supervised feature selection/ranking filters for high-dimensional datasets. These methods use low-complexity relevance and redundancy criteria, applicable to supervised, semi-supervised, and unsupervised learning, being able to act as pre-processors for computationally intensive methods to focus their attention on smaller subsets of promising features. The experimental results, with up to 10(5) features, show the time efficiency of our methods, with lower generalization error than state-of-the-art techniques, while being dramatically simpler and faster.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Empowered by virtualisation technology, cloud infrastructures enable the construction of flexi- ble and elastic computing environments, providing an opportunity for energy and resource cost optimisation while enhancing system availability and achieving high performance. A crucial re- quirement for effective consolidation is the ability to efficiently utilise system resources for high- availability computing and energy-efficiency optimisation to reduce operational costs and carbon footprints in the environment. Additionally, failures in highly networked computing systems can negatively impact system performance substantially, prohibiting the system from achieving its initial objectives. In this paper, we propose algorithms to dynamically construct and readjust vir- tual clusters to enable the execution of users’ jobs. Allied with an energy optimising mechanism to detect and mitigate energy inefficiencies, our decision-making algorithms leverage virtuali- sation tools to provide proactive fault-tolerance and energy-efficiency to virtual clusters. We conducted simulations by injecting random synthetic jobs and jobs using the latest version of the Google cloud tracelogs. The results indicate that our strategy improves the work per Joule ratio by approximately 12.9% and the working efficiency by almost 15.9% compared with other state-of-the-art algorithms.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Urinary tract infection (UTI) is one of the most prevalent pathologies in developed countries, particularly in women, characterized by the presence of bacterial growth in any part of the urinary system. Currently, urine culture is considered the gold standard method for the diagnosis of UTI. However, this method has several disadvantages including the time necessary for obtaining the results and the associated high costs. Therefore, it is important to evaluate new efficient and valuable methods for the diagnosis of these infections. Objectives: Presently, dipsticks are considered a possible valuable alternative to urine culture. This method has very low costs associated and the results can be obtained in few minutes. Here we aim to compare the sensibility, specificity, predictive value of a positive test and a negative test of both methods in order to determine the efficiency of the test strips method and also to characterize the microorganism more frequently isolated.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Passage of high-speed trains may induce high ground and track vibrations, which, besides increasing wheel, rail and track deterioration, may have a negative impact on the vehicle stability and on the passengers comfort. In this paper two distinct analyses are presented. The first one is dedicated to efficient decoupling of rail and soil vibrations by suggesting new interface materials in rail-sleeper fixing system, i.e. in the part where damping efficiency can be directly controlled and tested. The second analysis concerns with an adequate model of soils damping. Proper understanding and correct numerical simulation of this behaviour can help in suggesting soil improvement techniques.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Summary form only given. Bacterial infections and the fight against them have been one of the major concerns of mankind since the dawn of time. During the `golden years' of antibiotic discovery, during the 1940-90s, it was thought that the war against infectious diseases had been won. However currently, due to the drug resistance increase, associated with the inefficiency of discovering new antibiotic classes, infectious diseases are again a major public health concern. A potential alternative to antibiotic treatments may be the antimicrobial photodynamic inactivation (PDI) therapy. To date no indication of antimicrobial PDI resistance development has been reported. However the PDI protocol depends on the bacteria species [1], and in some cases on the bacteria strains, for instance Staphylococcus aureus [2]. Therefore the development of PDI monitoring techniques for diverse bacteria strains is critical in pursuing further understanding of such promising alternative therapy. The present works aims to evaluate Fourier-Transformed-Infra-Red (FT-IR) spectroscopy to monitor the PDI of two model bacteria, a gram-negative (Escherichia coli) and a gram-positive (S. aureus) bacteria. For that a high-throughput FTIR spectroscopic method was implemented as generally described in Scholz et al. [3], using short incubation periods and microliter quantities of the incubation mixture containing the bacteria and the PDI-drug model the known bactericidal tetracationic porphyrin 5,10,15,20-tetrakis (4-N, N, Ntrimethylammoniumphenyl)-porphyrin p-tosylate (TTAP4+). In both bacteria models it was possible to detect, by FTIR-spectroscopy, the drugs effect on the cellular composition either directly on the spectra or on score plots of principal component analysis. Furthermore the technique enabled to infer the effect of PDI on the major cellular biomolecules and metabolic status, for example the turn-over metabolism. In summary bacteria PDI was monitored in an economic, rapid (in minutes- , high-throughput (using microplates with 96 wells) and highly sensitive mode resourcing to FTIR spectroscopy, which could serve has a technological basis for the evaluation of antimicrobial PDI therapies efficiency.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Dissertação para obtenção do Grau de Mestre em Biotecnologia

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Electrical and Computer Engineering of the Faculdade de Ciências e Tecnologia of Universidade Nova de Lisboa

Relevância:

30.00% 30.00%

Publicador:

Resumo:

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics