943 resultados para Weighted average power tests


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There is little information on Caribbean soccer players. Thus, the aim this study was to descriptive and to compare the anthropometric, motor and aerobic fitness profile between Trinidad and Tobago team professional and junior soccer players. Twenty six soccer players were evaluated (14 professional and 12 junior): anthropometric (height, body mass, BMI, body fat percent), flexibility (sit and reach), velocity (30 m), explosive strength (horizontal and vertical jump), anaerobic power (maximum, mean and minimum power, index of fatigue) and maximum aerobic power. Student Test-t to independent sample was used in statistical analyzes, considering 5% of significance (p<0,05). Results of professional and junior players were, respectively: height (180,6 ± 8,1; 175,0 ± 6,9 cm), body mass (77,1 ± 7,5; 70,6 ± 8,7 kg); BMI (23,6 ± 1,5 / 23,0 ± 1,6 kgm 2 ); body fat (11,9 ± 1,7; 11,6 ± 1,2 %); sitting and reaching (24,9 ± 10,3; 24,9 ± 7,7 cm); velocity (30 m) (4,61 ± 0,14; 4,66 ± 0,15 s); horizontal jump (263,4 ± 14,9; 239,7 ± 12,1 cm); vertical jump (58,7 ± 4,3; 54,6 ± 6,6 cm); maximum power (7,9 ± 0,9; 6,6 ± 0,8 w∙kg-1 ); mean power (6,5 ± 0,7; 5,4 ± 0,9 w∙kg-1 ); minimum power (5,3 ± 0,7; 4,3 ± 1,1 w∙kg-1 ); index of fatigue (33,0 ± 7,9; 34,8 ± 12,8 %); aerobic power (55,0 ± 3,2; 57,2 ± 4,8 ml∙kg-1 ∙min-1 ). Professional players presented higher horizontal jump and maximum, mean and minimum anaerobic power in comparing to the junior players. The highest values of power tests for the lower limbs may be relationship to the longer time of practice in the modality of professional players, which can also indicate a higher level of specialization, which gives priority to the training of power (force and velocity).

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The purpose of this study is to characterize the geological subsurface structure of the diabase sill of the Paraná Magmatic Province intruded in the Itararé Group, located near the city of Limeira, in the east-central region of São Paulo state. The magnetometric method served as an important tool defining the igneous body in view of the great contrast between the physical properties of the diabase sill and the host sandstones. Previous cartographic data signaled in region a possible lateral continuity in subsurface, of the various sills that occur in the region. However, the magnetic data obtained herein indicate that the area of occurrence of this body is very restricted and independent of the others observed in the region. The analysis of the radial average power spectrum obtained allowed determine the interval of number of waves adequate for the separation of shallow and deep sources, and thus conclude that the sill of the Limeira region is located more than 100 m deep.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The sunflower oleaginous is the fourth of recognized importance in the oil production and few studies related to agricultural operations adopted for this crop. The objective of the present work was to study the performance of agricultural machines in the conventional tillage and reduced in the plantation of the sunflower crop. The experiment was installed at the Experimental Farm of Lageado, belonging to the Faculty of Agricultural Sciences of UNESP, located in Botucatu-SP. It consisted of two types of tillage (conventional tillage-CC and reduced tillage-CR), with experimental design in randomized blocks and four replications. The treatment CC promoted less coverage of the soil surface protected with waste when compared to CR treatment. The chisel plow was the tillage of equipment that required the tractor higher average traction force, average power traction and slippage, consequently, promoted lower average speed of work. The theoretical field capacity and area of land involved in the treatment CR were superior when compared to treatment CC, thereby lower consumption of fuel per hour worked was lower in CR treatment.

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Forage sorghum can be grown in areas and environmental conditions dry and warm, where the productivity of other forage plants can often be uneconomical. The soil disturbance can be made only on the lines of planting (direct seeding) or entirely from the area for seeding (conventional tillage), as plowing, harrowing, subsoiling and chiseling (minimum tillage). The displacement speed ideal for planting is one in which the groove is opened and closed without removing the over-ground, allowing the distribution of seed spacing and depth constant. The experiment was conducted in a soil classified as Typic Oxisol at Lageado Experimental Farm, Faculty of Agronomic Sciences, UNESP, Botucatu campus. This study aimed to evaluate the response of sorghum in four forward speeds (3, 5, 6 and 9 km h-1) and four systems of soil management: SD (direct seeding), GP (harrow + sowing), LPG (disc harrow and two light disking + sowing) and CR (scarification and seeding). Data was subjected to analysis of variance in a factorial 4 x 4 and a randomized block design with split plots. The following parameters were determined: average speed, average strength of the drawbar, the average power drawbar, theoretical field capacity of the tractor-equipment, fuel consumption per hour. For the conditions under which the experiment was conducted, it was concluded that the hourly fuel consumption was not influenced by tillage systems and was inversely proportional to the increase of speed work, and that the change of speed in the sowing operation did not provide additional the values of average traction force on the bar of the tractor-planter.

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Using the Geographic Information System (GIS) and taking into account its capability to analyze spatial data, a database of updated spatial data from the sub-basin of the Descalvado stream, Botucatu, SP, was developed to provide an evaluation and diagnosis of the area concerning land use and the degradation processes therein. Through GIS, priority areas for forest recovery were defined by Multicriteria Evaluation and using the Ordered Weighted Average method. The latter allows the decision maker to define the area to be recovered, facing limitation of resources, among one of the proposed scenarios, or do it in stages. The study showed that there are accelerated erosion processes in the headwaters of the springs of water bodies; there is also fragmentation of native vegetation, especially in hillside areas, and little presence of native vegetation in riparian areas. The application of the multicriteria analysis using the Ordered Weighted Average was important as it systematized and discriminated scenarios of priority for forest recovery.

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After several years of successively rising land values and cash rents, Nebraska’s farmland markets throttled back during 2008. Preliminary results from the University of Nebraska-Lincoln’s 2009 Nebraska Farm Real Estate Market Survey show a clear picture of the market mood turning very cautious in response to the U.S. and global economic downturns. As of February 1, 2009, the weighted average value of Nebraska farmland was $1,424 per acre, identical to the year-earlier level (Figure 1 and Table 1 at end of article). Likewise, estimated 2009 cash rents are stable to slightly down from 2008 levels throughout most of the state.

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Corn Suitability ratings have been used for many years in other parts of the Corn Belt as an agronomic measure of soil productivity, and in turn, some correlation with associated cropland values. For example, in Iowa the Corn Suitability Rating (CSR) is used extensively as a measure of soil productivity across regions and counties, and even down to parcel levels. Google on Iowa CSR, and you will find weighted average CSRs for each county, as well as private firms offering detailed analysis of CSR for any parcel of land in the state. The intent is to provide an index (between 5 and 100) of potential yields for row crop production.

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We aimed to investigate the role of betaine supplementation on muscle phosphorylcreatine (PCr) content and strength performance in untrained subjects. Additionally, we compared the ergogenic and physiological responses to betaine versus creatine supplementation. Finally, we also tested the possible additive effects of creatine and betaine supplementation. This was a double-blind, randomized, placebo-controlled study. Subjects were assigned to receive betaine (BET; 2 g/day), creatine (CR; 20 g/day), betaine plus creatine (BET + CR; 2 + 20 g/day, respectively) or placebo (PL). At baseline and after 10 days of supplementation, we assessed muscle strength and power, muscle PCr content, and body composition. The CR and BET + CR groups presented greater increase in muscle PCr content than PL ( = 0.004 and = 0.006, respectively). PCr content was comparable between BET versus PL ( = 0.78) and CR versus BET + CR ( = 0.99). CR and BET + CR presented greater muscle power output than PL in the squat exercise following supplementation ( = 0.003 and = 0.041, respectively). Similarly, bench press average power was significantly greater for the CR-supplemented groups. CR and BET + CR groups also showed significant pre- to post-test increase in 1-RM squat and bench press (CR: = 0.027 and < 0.0001; BET + CR: = 0.03 and < 0.0001 for upper- and lower-body assessments, respectively) No significant differences for 1-RM strength and power were observed between BET versus PL and CR versus BET + CR. Body composition did not differ between the groups. In conclusion, we reported that betaine supplementation does not augment muscle PCr content. Furthermore, we showed that betaine supplementation combined or not with creatine supplementation does not affect strength and power performance in untrained subjects.

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In this letter, we describe a simple and effective technique to prevent evaporation in liquid-core photonic crystal fibers (PCFs). The technique consists of using a micropipette to deploy a micro-droplet of an ultraviolet curable polymer adhesive in both core inputs. After it is cured, the adhesive creates sealing polymer plugs with quite satisfactory insertion loss (overall optical transmission of about 15%). Processed fibers remained liquid-filled for at least six weeks. From a practical point of view, we conducted a supercontinuum generation experiment in a water-core PCF to demonstrate a 120-minute spectral width stability and the ability to withstand at least 3-mW average power at the sealed fiber input. Similar experiments carried out with nonsealed fibers produced supercontinuum spectra lasting no longer than 10 minutes, with average powers kept below 0.5 mW to avoid thermally induced evaporation.

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One of the clinical limitations of the photodynamic therapy (PDT) is the reduced light penetration into biological tissues. Pulsed lasers may present advantages concerning photodynamic response when compared to continuous wave (CW) lasers operating under the same average power conditions. The aim of this study was to investigate PDT-induced response when using femtosecond laser (FSL) and a first-generation photosensitizer (Photogem) to evaluate the induced depth of necrosis. The in vitro photodegradation of the sensitizer was monitored during illumination either with CWor an FSL as an indirect measurement of the PDT response. Healthy liver of Wistar rats was used to evaluate the tissue response. The photosensitizer was endovenously injected and 30 min after, an energy dose of 150 Jcm-2 was delivered to the liver surface. We observed that the photodegradation rate evaluated via fluorescence spectroscopy was higher for the FSL illumination. The FSL-PDT produced a necrosis nearly twice as deep when compared to the CW-PDT. An increase of the tissue temperature during the application was measured and was not higher than 2.5 °C for the CW laser and not higher than 4.5 °C for the pulsed laser. FSL should be considered as an alternative in PDT applications for improving the results in the treatment of bulky tumors where higher light penetration is required.

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In the work underlying this thesis solid-phase microextraction (SPME) was evaluated as a passive sampling technique for organophosphate triesters in indoor air. These compounds are used on a large scale as flame-retarding and plastizicing additives in a variety of materials and products, and have proven to be common pollutants in indoor air. The main objective of this work was to develop an accurate method for measuring the volatile fraction. Such a method can be used in combination with active sampling to obtain information regarding the vapour/particulate distribution in different indoor environments. SPME was investigated under both equilibrium and non-equilibrium conditions and parameters associated with these different conditions were estimated. In Paper I, time-weighted average (TWA) SPME under dynamic conditions was investigated in order to obtain a fast air sampling method for organophosphate triesters. Among the investigated SPME coatings, the absorptive PDMS polymer had the highest affinity for the organophosphate triesters and was consequently used in all further work. Since the sampling rate is dependent on the agitation conditions, the linear airflow rates had to be carefully considered. Sampling periods as short as 1 hour were shown to be sufficient for measurements in the ng-μg m-3 range when using a PDMS 100-μm fibre and a linear flow rate above 7 cm s-1 over the fibre. SPME under equilibrium conditions is rather time-consuming, even under dynamic conditions, for slowly partitioning compounds such as organophosphate triesters. Nevertheless, this method has some significant advantages. For instance, the limit of detection is much lower compared to 1 h TWA sampling. Furthermore, the sampling time can be ignored as long as equilibrium has been attained. In Paper II, SPME under equilibrium conditions was investigated and evaluated for organophosphate triester vapours. Since temperature and humidity are closely associated with the distribution constant a simple study of the effect of these parameters was performed. The obtained distribution constants were used to determine the air levels in a common indoor environment. SPME and parallel active sampling on filters yielded similar results, indicating that the detected compounds were almost entirely associated with the vapour phase To apply dynamic SPME method in the field a sampler device, which enables controlled linear airflow rates to be applied, was constructed and evaluated (Paper III). This device was developed for application of SPME and active sampling in parallel. A GC/PICI-MS/MS method was developed and used in combination with active sampling of organophosphate triesters in indoor air (Paper IV). The combination of MS/MS and the soft ionization achieved with methanol as reagent gas yielded high selectivity and detection limits comparable to those provided by GC with nitrogen-phosphorus detection (NPD). The method limit of detection, when sampling 1.5 m3 of air, was in the range 0.1-1.4 ng m-3. In Paper V, the developed MS method was used in combination with SPME for indoor air measurements. The levels detected in the investigated indoor environments range from a few ng to μg m-3. Tris(2-chloropropyl) phosphate was detected at a concentration as high as 7 μg m-3 in a newly rebuilt lecture room.

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The convergence of information technology and consumer electronics towards battery powered portable devices has increased the interest in high efficiency, low dissipation amplifiers. Class D amplifiers are the state of the art in low power consumption and high performance amplification. In this thesis we explore the possibility of exploiting nonlinearities introduced by the PWM modulation, by designing an optimized modulation law which scales its carrier frequency adaptively with the input signal's average power while preserving the SNR, thus reducing power consumption. This is achieved by means of a novel analytical model of the PWM output spectrum, which shows how interfering harmonics and their bandwidth affect the spectrum. This allows for frequency scaling with negligible aliasing between the baseband spectrum and its harmonics. We performed low noise power spectrum measurements on PWM modulations generated by comparing variable bandwidth, random test signals with a variable frequency triangular wave carrier. The experimental results show that power-optimized frequency scaling is both feasible and effective. The new analytical model also suggests a new PWM architecture that can be applied to digitally encoded input signals which are predistorted and compared with a cosine carrier, which is accurately synthesized by a digital oscillator. This approach has been simulated in a realistic noisy model and tested in our measurement setup. A zero crossing search on the obtained PWM modulation law proves that this approach yields an equivalent signal quality with respect to traditional PWM schemes, while entailing the use of signals whose bandwidth is remarkably smaller due to the use of a cosine instead of a triangular carrier.

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This thesis deal with the design of advanced OFDM systems. Both waveform and receiver design have been treated. The main scope of the Thesis is to study, create, and propose, ideas and novel design solutions able to cope with the weaknesses and crucial aspects of modern OFDM systems. Starting from the the transmitter side, the problem represented by low resilience to non-linear distortion has been assessed. A novel technique that considerably reduces the Peak-to-Average Power Ratio (PAPR) yielding a quasi constant signal envelope in the time domain (PAPR close to 1 dB) has been proposed.The proposed technique, named Rotation Invariant Subcarrier Mapping (RISM),is a novel scheme for subcarriers data mapping,where the symbols belonging to the modulation alphabet are not anchored, but maintain some degrees of freedom. In other words, a bit tuple is not mapped on a single point, rather it is mapped onto a geometrical locus, which is totally or partially rotation invariant. The final positions of the transmitted complex symbols are chosen by an iterative optimization process in order to minimize the PAPR of the resulting OFDM symbol. Numerical results confirm that RISM makes OFDM usable even in severe non-linear channels. Another well known problem which has been tackled is the vulnerability to synchronization errors. Indeed in OFDM system an accurate recovery of carrier frequency and symbol timing is crucial for the proper demodulation of the received packets. In general, timing and frequency synchronization is performed in two separate phases called PRE-FFT and POST-FFT synchronization. Regarding the PRE-FFT phase, a novel joint symbol timing and carrier frequency synchronization algorithm has been presented. The proposed algorithm is characterized by a very low hardware complexity, and, at the same time, it guarantees very good performance in in both AWGN and multipath channels. Regarding the POST-FFT phase, a novel approach for both pilot structure and receiver design has been presented. In particular, a novel pilot pattern has been introduced in order to minimize the occurrence of overlaps between two pattern shifted replicas. This allows to replace conventional pilots with nulls in the frequency domain, introducing the so called Silent Pilots. As a result, the optimal receiver turns out to be very robust against severe Rayleigh fading multipath and characterized by low complexity. Performance of this approach has been analytically and numerically evaluated. Comparing the proposed approach with state of the art alternatives, in both AWGN and multipath fading channels, considerable performance improvements have been obtained. The crucial problem of channel estimation has been thoroughly investigated, with particular emphasis on the decimation of the Channel Impulse Response (CIR) through the selection of the Most Significant Samples (MSSs). In this contest our contribution is twofold, from the theoretical side, we derived lower bounds on the estimation mean-square error (MSE) performance for any MSS selection strategy,from the receiver design we proposed novel MSS selection strategies which have been shown to approach these MSE lower bounds, and outperformed the state-of-the-art alternatives. Finally, the possibility of using of Single Carrier Frequency Division Multiple Access (SC-FDMA) in the Broadband Satellite Return Channel has been assessed. Notably, SC-FDMA is able to improve the physical layer spectral efficiency with respect to single carrier systems, which have been used so far in the Return Channel Satellite (RCS) standards. However, it requires a strict synchronization and it is also sensitive to phase noise of local radio frequency oscillators. For this reason, an effective pilot tone arrangement within the SC-FDMA frame, and a novel Joint Multi-User (JMU) estimation method for the SC-FDMA, has been proposed. As shown by numerical results, the proposed scheme manages to satisfy strict synchronization requirements and to guarantee a proper demodulation of the received signal.