PWM CONTROLLER'S MODELS FOR INVESTIGATION ACS IN SPICEFAMILY ECAD PROGRAMS

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O. V. VASYLENKO

2018-05-01

Full Text Available Purpose. To improve simulation and design of Automatic Control Systems in the SPICE-compatible programs and to obtain separate economic and universal macromodels of PWM controller. Development of an PWM controller economical macromodel for the study of automatic control systems (ACS in computer-aided design (ECAD  programs, which does not generate algorithmic failures in comparison with the existing models of PWM. Findings. Analysis of SPICE-family applications’ mathematical basis allowed to classifying existing models of PWM-controllers, defining their suitability for ACS simulation. The criteria for the synthesis of new models have been defined. For the SPICE 3G algorithms, the Switch and Averaged models based on behavioral elements has been developed. Universal and economical PWM controller macromodel based on the simple algorithm for determining the output signal with minimum numbers of input parameters has been designed. For the Automated Measuring magnetic susceptibility System, the macromodel of quasi-PWM signal generator have been designed, which is used in the compensation subsystem. This model is different from the existing ones: it synthesizes the staircase output signal instead the pulse one, thus, there is direct control of the amplitude of the output signal, which is taken averaged. The adequacy of the models is confirmed as comparison of the simulation results during investigations of the model already existing in the SPICE program, as well as the results of experiments with real ACS. The modeling of the PWM controller was carried out on the basis of behavioral elements from the ECAD library, simulation (solution of algebra-differential equations systems with programming elements is based on SPICE algorithms. The object of the study was the simulation process of ACS with the pulse-width principle of adjusting the output value. The subject of the research are the models of PWM controllers. Originality. The new macromodel of PWM

Bi-Frequency Modulated Quasi-Resonant Converters: Theory and Applications

Science.gov (United States)

Zhang, Yuefeng

1995-01-01

To avoid the variable frequency operation of quasi -resonant converters, many soft-switching PWM converters have been proposed, all of them require an auxiliary switch, which will increase the cost and complexity of the power supply system. In this thesis, a new kind of technique for quasi -resonant converters has been proposed, which is called the bi-frequency modulation technique. By operating the quasi-resonant converters at two switching frequencies, this technique enables quasi-resonant converters to achieve the soft-switching, at fixed switching frequencies, without an auxiliary switch. The steady-state analysis of four commonly used quasi-resonant converters, namely, ZVS buck, ZCS buck, ZVS boost, and ZCS boost converter has been presented. Using the concepts of equivalent sources, equivalent sinks, and resonant tank, the large signal models of these four quasi -resonant converters were developed. Based on these models, the steady-state control characteristics of BFM ZVS buck, BFM ZCS buck, BFM ZVS boost, and BFM ZCS boost converter have been derived. The functional block and design consideration of the bi-frequency controller were presented, and one of the implementations of the bi-frequency controller was given. A complete design example has been presented. Both computer simulations and experimental results have verified that the bi-frequency modulated quasi-resonant converters can achieve soft-switching, at fixed switching frequencies, without an auxiliary switch. One of the application of bi-frequency modulation technique is for EMI reduction. The basic principle of using BFM technique for EMI reduction was introduced. Based on the spectral analysis, the EMI performances of the PWM, variable-frequency, and bi-frequency modulated control signals was evaluated, and the BFM control signals show the lowest EMI emission. The bi-frequency modulated technique has also been applied to the power factor correction. A BFM zero -current switching boost converter has

Soft-switching PWM full-bridge converters topologies, control, and design

CERN Document Server

Ruan, Xinbo

2014-01-01

Soft-switching PWM full-bridge converters have been widely used in medium-to-high power dc-dc conversions for topological simplicity, easy control and high efficiency. Early works on soft-switching PWM full-bridge converter by many researchers included various topologies and modulation strategies.  However, these works were scattered, and the relationship among these topologies and modulation strategies had not been revealed. This book intends to describe systematically the soft-switching techniques for pulse-width modulation (PWM) full-bridge converters, including the topologies, control and

Transistorized PWM inverter-induction motor drive system

Science.gov (United States)

Peak, S. C.; Plunkett, A. B.

1982-01-01

This paper describes the development of a transistorized PWM inverter-induction motor traction drive system. A vehicle performance analysis was performed to establish the vehicle tractive effort-speed requirements. These requirements were then converted into a set of inverter and motor specifications. The inverter was a transistorized three-phase bridge using General Electric power Darlington transistors. The description of the design and development of this inverter is the principal object of this paper. The high-speed induction motor is a design which is optimized for use with an inverter power source. The primary feedback control is a torque angle control with voltage and torque outer loop controls. A current-controlled PWM technique is used to control the motor voltage. The drive has a constant torque output with PWM operation to base motor speed and a constant horsepower output with square wave operation to maximum speed. The drive system was dynamometer tested and the results are presented.

SYNTHESIS OF VOLTAGES OF UNIFORM PWM IN TIME REGULATION

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A. G. Stryzhniou

2014-01-01

Full Text Available The article describes a process of synthesis and qualitative assessment of the harmonic composition of voltages of multiple and single PWM pulses in time regulation, being, along with amplitude, frequency and phase method, one of control methods of an asynchronous motor. The main point of time regulation is that a pause after any two single PWM pulses with different polarity or after any two groups of multiple PWM pulses with different polarity changes during a process of regulation. Feature of time regulation is that a motor has fast response in the range of small-signal of control and good linearity of speed-torque characteristics in the whole control range. Analytical expressions of parameters of PWM pulses ai and ti are obtained which allow to simplify considerably a process of formation and implementation of time regulation using tabular or indexed-tabular methods. These expressions allow not only to define voltage amplitude of  harmonic but also to perform qualitative assessment of harmonic composition of output voltages at time regulation. It is specified that harmonic frequencies wi = w0/q change in inverse proportion to magnitude of parameter q during a process of regulation and there is a replacement of a fundamental frequency by frequencies of higher harmonics.The offered approach allows to synthesize voltage of uniform single and multiple PWM pulses and to perform their comparative and qualitative analysis and the obtained expressions can be used at modeling of AC motor work. Voltage of multiple PWM pulses which is formed using stepped reference voltage with even quantity of steps in a half period and a pause on a zero level has the best parameters by criterion of a minimum of harmonic components and a maximum of a factor of anharmonicity Kнс at time regulation.

Analysis of Input and Output Ripples of PWM AC Choppers

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Pekik Argo Dahono

2008-11-01

Full Text Available This paper presents an analysis of input and output ripples of PWM AC choppers. Expressions of input and output current and voltage ripples of single-phase PWM AC choppers are first derived. The derived expressions are then extended to three-phase PWM AC choppers. As input current and output voltage ripples specification alone cannot be used to determine the unique values of inductance and capacitance of the LC filters, an additional criterion based on the minimum reactive power is proposed. Experimental results are included in this paper to show the validity of the proposed analysis method.

EMC Increasing of PWM Rectifier in Comparison with Classical Rectifier

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R. Dolecek

2008-12-01

Full Text Available Pulse width modulated rectifier is a very popular topic nowadays. The modern industrial production demands continuous and lossless conversion of electrical energy parameters. This need leads to wide spread of power semiconductor converters. The rapid development in power electronics and microprocessor technology enables to apply sophisticated control methods that eliminate negative side effects of the power converters on the supply network. The phase controlled thyristor rectifiers overload the supply network with higher harmonics and reactive power consumption. That is why the PWM rectifier is being examined. In comparison with the phase controlled rectifier it can be controlled to consume nearly sinusoidal current with power factor equal to unity. Another advantage is its capability of energy recuperation. The PWM rectifier can assert itself for its good behavior in many applications, for example as an input rectifier in indirect frequency converter, or in traction. Traction vehicles equipped with PWM rectifier do not consume reactive power, do not load the supply network with higher harmonics, and the recuperation is possible. The paper deals with the PWM rectifier functional model realization and examination. Electromagnetic compatibility of PWM rectifier and classical phase controlled rectifier is compared on the basis of the input current harmonic analysis.

A digital input class-D audio amplifier with sixth-order PWM

International Nuclear Information System (INIS)

Luo Shumeng; Li Dongmei

2013-01-01

A digital input class-D audio amplifier with a sixth-order pulse-width modulation (PWM) modulator is presented. This modulator moves the PWM generator into the closed sigma—delta modulator loop. The noise and distortions generated at the PWM generator module are suppressed by the high gain of the forward loop of the sigma—delta modulator. Therefore, at the output of the modulator, a very clean PWM signal is acquired for driving the power stage of the class-D amplifier. A sixth-order modulator is designed to balance the performance and the system clock speed. Fabricated in standard 0.18 μm CMOS technology, this class-D amplifier achieves 110 dB dynamic range, 100 dB signal-to-noise rate, and 0.0056% total harmonic distortion plus noise. (semiconductor integrated circuits)

Feedforward Synchronised PWM for Adjustable Speed AC Drives with Different Control Modes

DEFF Research Database (Denmark)

Oleschuk, Valentin; Blaabjerg, Frede; Jensen, Flemming Buus

2002-01-01

This paper presents a novel method of direct synchronised pulswidth modulation (PWM) for three-phase voltage source inverters, feeding induction motors with different control regimes. It is based on the universal algorithm with either simplified algebraic or accurate trigonometric control functions......, with vector approached for determination of the pulse patterns, with vector approach for determination of the pulse patterns. Different control modes of the drive system with synchronised PWM, including standard scalar V/F control, and also V2/F = constant and V/F2 = constant control regimes, have been...... analysed in the paper. Simulations give the behaviour of the PWM techniques proposed. Both continuous and discontinuous schemes of synchronised PWM, applied for the corresponding control regime, have been analysed and compared....

Prediction of power losses in silicon iron sheets under PWM voltage supply

International Nuclear Information System (INIS)

Amar, M.; Kaczmarek, R.; Protat, F.

1994-01-01

The behavior of iron losses in silicon iron steels submitted to a PWM voltage is studied. The influence of modulation parameters (the depth of modulation and the number of eliminated harmonics) is clarified. In particular, the idea of an equivalent alternating pulse voltage that gives the same iron losses as the PWM voltage is established. An estimation formula for iron losses under the PWM voltage is developed based on the loss separation model and the voltage form factor. ((orig.))

Boosted PWM open loop control of hydraulic proportional valves

International Nuclear Information System (INIS)

Amirante, R.; Innone, A.; Catalano, L.A.

2008-01-01

This paper presents an innovative open loop control technique for direct single stage hydraulic proportional valves whose response rate is significantly higher than that obtained by standard open loop control techniques, even comparable to more costly commercial closed loop systems. Different from standard open loop techniques, which provide the coil with a constant current proportional to the target position, the control strategy proposed in this paper employs the peak and hold (P and H) technique, widely used in Diesel engine modern supply systems, to boost the duty cycle value of the pulse width modulation (PWM) signal for a short time, namely during the spool displacement, while maintaining a lower duty cycle for holding the spool in the required opening position. The developed 'boosted PWM' technique only requires a low cost microcontroller, such as a peripheral interface controller (PIC) equipped with a metal oxide semiconductor (MOS) power driver. The PWM parameters are calibrated as a function of the spool displacement so as to maximize the response rate without introducing overshoots: the collected data are stored in the PIC. Different valve opening procedures with step response have been compared to demonstrate the merits of the proposed boosted PWM technique. No overshoots have been registered. Moreover, the proposed method is characterized by a significantly higher response rate with respect to a standard open loop control, which approximately has the same cost. Similar experimental tests show that the proposed boosted PWM technique has a response rate even higher than that provided by the more costly commercial closed loop system mounted on the valve, and it produces no overshoots

Boosted PWM open loop control of hydraulic proportional valves

Energy Technology Data Exchange (ETDEWEB)

Amirante, R.; Catalano, L.A. [Dipartimento di Ingegneria Meccanica e Gestionale, Politecnico di Bari, Via Re David 200, 70125 Bari (Italy); Innone, A. [Universita degli Studi di Foggia, via Napoli, 25 Foggia (Italy)

2008-08-15

This paper presents an innovative open loop control technique for direct single stage hydraulic proportional valves whose response rate is significantly higher than that obtained by standard open loop control techniques, even comparable to more costly commercial closed loop systems. Different from standard open loop techniques, which provide the coil with a constant current proportional to the target position, the control strategy proposed in this paper employs the peak and hold (P and H) technique, widely used in Diesel engine modern supply systems, to boost the duty cycle value of the pulse width modulation (PWM) signal for a short time, namely during the spool displacement, while maintaining a lower duty cycle for holding the spool in the required opening position. The developed 'boosted PWM' technique only requires a low cost microcontroller, such as a peripheral interface controller (PIC) equipped with a metal oxide semiconductor (MOS) power driver. The PWM parameters are calibrated as a function of the spool displacement so as to maximize the response rate without introducing overshoots: the collected data are stored in the PIC. Different valve opening procedures with step response have been compared to demonstrate the merits of the proposed boosted PWM technique. No overshoots have been registered. Moreover, the proposed method is characterized by a significantly higher response rate with respect to a standard open loop control, which approximately has the same cost. Similar experimental tests show that the proposed boosted PWM technique has a response rate even higher than that provided by the more costly commercial closed loop system mounted on the valve, and it produces no overshoots. (author)

High flexibility and low cost digital implementation for modern PWM strategies

DEFF Research Database (Denmark)

Mathe, Laszlo; Sera, Dezso; Kerekes, Tamas

2011-01-01

like AZSPWM, NSPWM, or ACRPWM. By using a conventional PWM unit from a microcontroller, these modern modulation techniques are often difficult, or even impossible, to implement. The proposed method can be used to implement PWM strategies even for those microcontrollers which are not equipped...

A PWM strategy for acoustic noise reduction for grid-connected single-phase inverters

Energy Technology Data Exchange (ETDEWEB)

Shao, R.; Guo, Z.; Chang, L. [New Brunswick Univ., Fredericton, NB (Canada). Dept. of Electrical and Computer Engineering

2006-07-01

This paper presented a newly proposed and improved pulse width modulation (PWM) strategy for grid-connected single-phase inverters. Small distributed generators using energy from renewable resources such as PV and wind systems typically use grid-connected single-phase inverters as voltage source inverters for good acoustic performance. PWM is generally applied in these inverters in order to achieve good waveforms of output current as required by interconnection standards. In routine simultaneous switching PWM methods, the current ripples through the inverter output filter inductor are at the carrier switching frequency, which is one of the major causes for inverter acoustic noise. The new PWM strategy effectively alleviates acoustic noise and improves output power quality. It is based on the principle of evenly splitting the switching of Insulated Gate Bipolar Transistors (IGBT) in each switching cycle among all IGBTs of the full bridge, thereby using a non-simultaneous mode of PWM which doubles the output current ripple frequency. This increases the inductor current ripple frequency to twice the carrier frequency. It is therefore possible to increase the current ripple frequency, or noise frequency into the range of ultrasonic which is inaudible to the human ear, without increasing the inverter's switching frequency to which the inverter's switching loss is proportional. In addition, this new PWM scheme can reduce the output current harmonics distortion and dc link current ripples. As such, lower capacitance in dc link capacitors and lower inductance of output inductor are needed. The improved PWM scheme was verified in a 3 kW grid-connected single-phase inverter. It was shown that the PWM strategy can be readily implemented with a digital signal processing microcontroller. 8 refs., 11 figs.

A Zero Input Current Ripple ZVS/ZCS Boost Converter with Boundary-Mode Control

Directory of Open Access Journals (Sweden)

Ching-Ming Lai

2014-10-01

Full Text Available In this paper, in order to achieve zero ripple conditions, the use of a ripple mirror (RM circuit for the boost converter is proposed. The operation modes are studied and steady-state analyses performed to show the merits of the proposed converter. It is found that the proposed RM circuit technique can provide much better flexibility than the two-phase interleaved boost converter for locating the zero ripple operating point in the design stage. In addition, the choice of using a boundary-mode control is mainly based on the consideration of achieving both ZVS (zero voltage switching/ZCS (zero current switching soft-switching and constant on-time control for the converter. To verify the performance of the proposed converter, a 48 V input and 200 W/200 V output prototype is constructed. Experimental results verify the effectiveness of the proposed converter.

A dual-path, current-sensing resistor-free boost LED driver with fast PWM dimming

International Nuclear Information System (INIS)

Zhou Minchao; Lü Danzhu; Cheng Lin; Hong Zhiliang; Liu, Bill Yang

2013-01-01

A boost LED driver featuring a high PWM dimming ratio and optimized efficiency is presented. This LED driver, which has a low dropout voltage and is able to drive 3–7 LEDs in series with constant output current and fast PWM dimming, provides an alternative technique for brightness adjustment. A dual-path control scheme with automatic switching and state maintenance is proposed. Meanwhile, a cascode current mirror structure is applied with the output transistor multiplexed as an LED PWM dimming transistor. Implemented in 0.5 μm 25 V BCD process, the measurement results show that a voltage conversion range of 5 V input to 6–24 V output with constant output current is obtained. With automatically switching dual-path control and an optimized current mirror, the response time during PWM dimming is reduced to as low as 240 ns and the efficiency keeps above 89% over a wide PWM dimming ratio - 250 mA output current. (semiconductor integrated circuits)

Discrete/PWM Ballast-Resistor Controller

Science.gov (United States)

King, Roger J.

1994-01-01

Circuit offers low switching loss and automatic compensation for failure of ballast resistor. Discrete/PWM ballast-resistor controller improved shunt voltage-regulator circuit designed to supply power from high-resistance source to low-impedance bus. Provides both coarse discrete voltage levels (by switching of ballast resistors) and continuous fine control of voltage via pulse-width modulation.

Performance analysis of samarium cobalt P.M. synchronous motor fed from PWM inverters

International Nuclear Information System (INIS)

Rahman, M.A.; Choudhury, M.A.

1985-01-01

This paper presents an analysis and performance of samarium cobalt permanent magnet (P.M.) synchronous motors fed from two types of voltage source pulse width modulated (PWM) inverters. The analysis and test results on the steady state performance of a P.M. motor fed from PWM inverters are presented. PWM inverters are used in variable voltage variable frequency applications to avoid a double conversion process of ordinary inverters. In drives, they are used for voltage and speed regulation of motors. Use of modulation technique in inverters also allow to eliminate or minimize selected harmonics from the inverter output voltage

Neural network based PWM AC chopper fed induction motor drive

Directory of Open Access Journals (Sweden)

Venkatesan Jamuna

2009-01-01

Full Text Available In this paper, a new Simulink model for a neural network controlled PWM AC chopper fed single phase induction motor is proposed. Closed loop speed control is achieved using a neural network controller. To maintain a constant fluid flow with a variation in pressure head, drives like fan and pump are operated with closed loop speed control. The need to improve the quality and reliability of the drive circuit has increased because of the growing demand for improving the performance of motor drives. With the increased availability of MOSFET's and IGBT's, PWM converters can be used efficiently in low and medium power applications. From the simulation studies, it is seen that the PWM AC chopper has a better harmonic spectrum and lesser copper loss than the Phase controlled AC chopper. It is observed that the drive system with the proposed model produces better dynamic performance, reduced overshoot and fast transient response. .

Apparent permeability of electrical steel under PWM magnetisation

International Nuclear Information System (INIS)

Moses, A.J.; Leicht, J.; Anderson, P.

2006-01-01

In recent years much attention has been paid to material performance under pulse width modulation (PWM) excitation conditions, which is of increasing importance to motor applications particularly in energy efficient variable speed drive systems. It is well known that in general, losses increase significantly with reducing modulation index, the increase depending on parameters such as silicon contents, thickness and grain size. The effect of the PWM waveform on permeability has attracted little attention until now. So in this paper its influence on the permeability of electrical steel is analysed and characterised. A prediction approach based on the permeability under sine wave excitation and total harmonic distortion is introduced which results in errors below 10% for non-electrical steel at 1.5 T

PWM pulse pattern optimization method using carrier frequency modulation. Carrier shuhasu hencho ni yoru PWM pulse pattern saitekikaho

Energy Technology Data Exchange (ETDEWEB)

Iwaji, Y.; Fukuda, S. (Hokkaido University, Sapporo (Japan))

1991-07-15

Sinusoidal inverters are getting more widely used keeping pace with the development of semiconductor switching elements. This paper discusses optimizing a PWM pulse pattern at an inverter output to drive an induction motor, proposes methods for improving distortion and torque ripples using a carrier frequency modulation (CFM), and describes a method for realizing the improvement through use of a single-chip microcomputer. The method defines evaluation parameters corresponding to the distortion and torque ripples, and optimizes the CFM depth to the parameters. The PWM pulse pattern has its voltage vector and time width so selected that the time integrated space vector of a three-phase voltage approaches a circular locus. Furthermore, the carrier frequency, that is the sampling frequency of the inverter, is also adjusted so that the above evaluation parameters are minimized. The addition of a new variable called the frequency modulation provides freedom in selecting an output characteristic as called for by the purpose. 12 refs., 18 figs.

Take Control of Fonts in Leopard

CERN Document Server

Zardetto, Sharon

2009-01-01

Install, organize, and use fonts with ease in Leopard! In this essential ebook, long-time Mac author Sharon Zardetto reveals all the details about how fonts work in Mac OS X 10.5 Leopard. She explains what folders your fonts reside in, in what order they load, and how to deal with font duplication. You'll also learn the ins and outs of different font installation methods; how to use Font Book to manage, validate, and organize fonts; how to make the most of character-rich Unicode fonts; and more. Whether you work in a font-intensive profession, use Unicode fonts for non-Roman languages, or wa

PWM control of current source type six-phase inverter with improved waveforms by coupling reactor; Ketsugo reactor ni yori hakei kaizen sareta denryugata rokuso inverter no PWM seigyo

Energy Technology Data Exchange (ETDEWEB)

Inami, K.; Danjo, M.; Kondo, Y.; Yamada, M. [Niihama Technical College, Ehime (Japan); Toki, K. [Shikoku Electric Power Co., Inc., Kagawa (Japan); Heike, J. [Shikoku Instrumentation Co. Ltd., Kagawa (Japan)

1998-10-01

A PWM method has been applied to a high capacity six phase current source inverter system in order to obtain sinusoidal output voltage and current. In this system, the three-phase coupling reactor is connected between the inverter output and an induction motor used as a load. Then the reactor eliminates harmonic components included in the inverter output current except 12k {+-} 1 (k=1,2,3)th order. As a result, the distortion factor of the inverter output current decreases. But the resonant circuit is composed of the capacitance of filter capacitor and the induction motor leakage inductance. Then the resonance current is superimposed on the induction motor phase currents. To solve this problem, the optimal PWM pattern is derived, so that the resonant current becomes very small. The order of the resonant frequency component of the induction motor phase current depend on the inverter frequency. Then total inverter frequency range is divided into several areas. The optimal PWM pattern is derived in each areas. As a result, the use of each optimal PWM pattern allows us to drive the induction motor, over a wide range of speed, under the condition of small distortion factor of phase currents. 5 refs., 10 figs., 1 tab.

EVALUATION OF VARIOUS UNIPOLAR MULTICARRIER PWM STRATEGIES FOR FIVE LEVEL FLYING CAPACITOR INVERTER

Directory of Open Access Journals (Sweden)

B. SHANTHI

2012-06-01

Full Text Available This paper presents the comparison of unipolar multicarrier Pulse Width Modulation (PWM techniques for the Flying Capacitor Multi Level Inverter (FCMLI. Due to switch combination redundancies, there are certain degrees of freedom to generate the five level AC output voltage. This paper presents the use of Control Freedom Degree (CFD combination. The effectiveness of the PWM strategies developed using CFD are demonstrated by simulation and experimentation. The results indicate that the multilevel inverter triggered by the developed USHPWM strategy exhibits reduced harmonics. PWM strategies developed are implemented in real time using dSPACE/Real Time Interface (RTI. The simulation and experimental output closely match with each other validating the strategies presented.

FONT DISCRIMINATIO USING FRACTAL DIMENSIONS

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S. Mozaffari

2014-09-01

Full Text Available One of the related problems of OCR systems is discrimination of fonts in machine printed document images. This task improves performance of general OCR systems. Proposed methods in this paper are based on various fractal dimensions for font discrimination. First, some predefined fractal dimensions were combined with directional methods to enhance font differentiation. Then, a novel fractal dimension was introduced in this paper for the first time. Our feature extraction methods which consider font recognition as texture identification are independent of document content. Experimental results on different pages written by several font types show that fractal geometry can overcome the complexities of font recognition problem.

Soft Switching Full-Bridge PWM DC/DC Converter Using Secondary Snubber

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Jaroslav Dudrik

2009-05-01

Full Text Available A novel full-bridge PWM DC/DCconverter with controlled secondary side rectifier usingsecondary snubber is presented in this paper.Limitation of the circulating current as well as softswitching for all power switches of the inverter isachieved for full load range from no-load to shortcircuit by using controlled rectifier and snubber on thesecondary side. Phase shift PWM control strategy isused for the converter. The principle of operation isexplained and analyzed and the experimental resultson a 1kW, 50 kHz laboratory model of the converterare presented.

Led spectral and power characteristics under hybrid PWM/AM dimming strategy

DEFF Research Database (Denmark)

Beczkowski, Szymon; Munk-Nielsen, Stig

2010-01-01

In order to dim LEDs the pulse width modulation (PWM) or amplitude modulation (AM) dimming scheme is typically used. Previous studies show that these dimming schemes can have opposite effects on diodes peak wavelength shift. An experimental study was conducted to test the behavior of InGaN diodes...... and phosphor-converted white diodes under hybrid PWM/AM modulation. Feed forward control schemes that provide stable peak wavelength position during dimming and the ability to compensate the thermally induced color shifts and the decrease of the luminous flux are investigated....

Highly Sensitive and Wide-Dynamic-Range Multichannel Optical-Fiber pH Sensor Based on PWM Technique

OpenAIRE

Md. Rajibur Rahaman Khan; Shin-Won Kang

2016-01-01

In this study, we propose a highly sensitive multichannel pH sensor that is based on an optical-fiber pulse width modulation (PWM) technique. According to the optical-fiber PWM method, the received sensing signal?s pulse width changes when the optical-fiber pH sensing-element of the array comes into contact with pH buffer solutions. The proposed optical-fiber PWM pH-sensing system offers a linear sensing response over a wide range of pH values from 2 to 12, with a high pH-sensing ability. The...

Isolated PDM and PWM DC-AC SICAMs[Pulse Density Modulated; Pulse Width Modulated

Energy Technology Data Exchange (ETDEWEB)

Ljusev, P.

2004-03-15

In this report a class of isolated PDM and PWM DC-AC SICAMs is described, which introduce the audio reference only in the output stage. AC-DC power supply is implemented in its simplest form: diode rectifier followed by a medium-size charge-storage capacitor. Isolation from the AC mains is achieved using a high frequency (HF) transformer, receiving the HF voltage pulses from the input 'inverter' stage and transferring them to the output 'rectifier+inverter' stage, which can use either PDM or PWM. The latter stage is then interfaced to the load using an output low-pass filter. Each of the dedicated stages is discussed in detail. Measurements on the master/slave PWM DC-AC SICAM prototype are presented to help benchmarking the performance of this class of SICAMs and identify the advantages and drawbacks. (au)

The 120V 20A PWM switch for applications in high power distribution

Science.gov (United States)

Borelli, V.; Nimal, W.

1989-08-01

A 20A/120VDC (voltage direct current) PWM (Pulse Width Modulation) Solid State Power Controller (SSPC) developed under ESA contract to be used in the power distribution system of Columbus is described. The general characteristics are discussed and the project specification defined. The benefits of a PWM solution over a more conventional approach, for the specific application considered are presented. An introduction to the SSPC characteristics and a functional description are presented.

Design and Experimental Investigations on a new ZCS Non-Isolated Bidirectional Converter based on Auxiliary resonant Circuit for DC Traction Vehicles

Directory of Open Access Journals (Sweden)

Veera Venkata Subrahmanya Kumar Bhajana

2017-12-01

Full Text Available This paper proposes a new ZCS non-isolated bidirectional converter for energy storage systems in DC Traction vehicles. The conventional hard-switched non-isolated bidirectional converter is additionally assisted with an auxiliary resonant cell, which is implemented with auxiliary IGBTs, resonant inductor and capacitor will provide the zero current switching, while the main IGBT commutates. This paper mainly deals with the design analysis, simulation and experimental investigations of the proposed converter are provided to prove the soft-switching capability and its overall performance. The 100-200V/2kW laboratory prototype has been implemented and tested to verify the theoretical assumptions and simulation results.

A Novel Application of Zero-Current-Switching Quasiresonant Buck Converter for Battery Chargers

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Kuo-Kuang Chen

2011-01-01

Full Text Available The main purpose of this paper is to develop a novel application of a resonant switch converter for battery chargers. A zero-current-switching (ZCS converter with a quasiresonant converter (QRC was used as the main structure. The proposed ZCS dc–dc battery charger has a straightforward structure, low cost, easy control, and high efficiency. The operating principles and design procedure of the proposed charger are thoroughly analyzed. The optimal values of the resonant components are computed by applying the characteristic curve and electric functions derived from the circuit configuration. Experiments were conducted using lead-acid batteries. The optimal parameters of the resonance components were determined using the load characteristic curve diagrams. These values enable the battery charger to turn on and off at zero current, resulting in a reduction of switching losses. The results of the experiments show that when compared with the traditional pulse-width-modulation (PWM converter for a battery charger, the buck converter with a zero- current-switching quasiresonant converter can lower the temperature of the activepower switch.

The comparison of radiosensitivity of human lymphocytes stimulated with PHA Con A and PWM

International Nuclear Information System (INIS)

Geng Yongzhi; Su Liaoyuan

1989-11-01

The transformation, DNA strand breaks and its repair ability in human peripheral blood lymphocytes stimulated with PHA, Con A and PWM were respectively assessed following exposure to 60 Co gamma rays by 3 H-thymidine uptake and hydroxylapatite chromatography. It was showed the transformation of lymphocytes stimulated with PHA, Con A and PWM were suppressed by gamma rays and the dose-effect curves were biphase within the range of 0∼8 Gy. The lymphocytes stimulated with PWM was the most resistant to gamma rays. The extent of DNA strand breaks in lymphocytes induced by gamma rays was linearly related to the dose within the range of 0∼30 Gy and was identical in three kinds of lymphocytes. After post-irradiation incubation of 37 deg C, the DNA strand breaks could be repaired incompletely and after maxium repair the strand breaks were observed again. The repair ratio of strand breaks in the lymphocytes stimulated with PWM was the highest in the cells with three mitogens. The results showed that the difference of radiation effect on the transformation is probably related to the repair ability of DNA strand breaks

High frequency three-phase PWM grid connected drive using silicon-carbide switches

DEFF Research Database (Denmark)

Kouchaki, Alireza; Pedersen, Jacob Lykke; Nymand, Morten

2016-01-01

This paper presents controller design procedure for a fully silicon-carbide (SiC) based three-phase grid-connected PWM drive. The influence of the feedforward compensation for the presented setup is studied and the transfer function of the system with feedforward is derived and compared with the ......This paper presents controller design procedure for a fully silicon-carbide (SiC) based three-phase grid-connected PWM drive. The influence of the feedforward compensation for the presented setup is studied and the transfer function of the system with feedforward is derived and compared...

Highly Sensitive and Wide-Dynamic-Range Multichannel Optical-Fiber pH Sensor Based on PWM Technique.

Science.gov (United States)

Khan, Md Rajibur Rahaman; Kang, Shin-Won

2016-11-09

In this study, we propose a highly sensitive multichannel pH sensor that is based on an optical-fiber pulse width modulation (PWM) technique. According to the optical-fiber PWM method, the received sensing signal's pulse width changes when the optical-fiber pH sensing-element of the array comes into contact with pH buffer solutions. The proposed optical-fiber PWM pH-sensing system offers a linear sensing response over a wide range of pH values from 2 to 12, with a high pH-sensing ability. The sensitivity of the proposed pH sensor is 0.46 µs/pH, and the correlation coefficient R² is approximately 0.997. Additional advantages of the proposed optical-fiber PWM pH sensor include a short/fast response-time of about 8 s, good reproducibility properties with a relative standard deviation (RSD) of about 0.019, easy fabrication, low cost, small size, reusability of the optical-fiber sensing-element, and the capability of remote sensing. Finally, the performance of the proposed PWM pH sensor was compared with that of potentiometric, optical-fiber modal interferometer, and optical-fiber Fabry-Perot interferometer pH sensors with respect to dynamic range width, linearity as well as response and recovery times. We observed that the proposed sensing systems have better sensing abilities than the above-mentioned pH sensors.

Highly Sensitive and Wide-Dynamic-Range Multichannel Optical-Fiber pH Sensor Based on PWM Technique

Science.gov (United States)

Khan, Md. Rajibur Rahaman; Kang, Shin-Won

2016-01-01

In this study, we propose a highly sensitive multichannel pH sensor that is based on an optical-fiber pulse width modulation (PWM) technique. According to the optical-fiber PWM method, the received sensing signal’s pulse width changes when the optical-fiber pH sensing-element of the array comes into contact with pH buffer solutions. The proposed optical-fiber PWM pH-sensing system offers a linear sensing response over a wide range of pH values from 2 to 12, with a high pH-sensing ability. The sensitivity of the proposed pH sensor is 0.46 µs/pH, and the correlation coefficient R2 is approximately 0.997. Additional advantages of the proposed optical-fiber PWM pH sensor include a short/fast response-time of about 8 s, good reproducibility properties with a relative standard deviation (RSD) of about 0.019, easy fabrication, low cost, small size, reusability of the optical-fiber sensing-element, and the capability of remote sensing. Finally, the performance of the proposed PWM pH sensor was compared with that of potentiometric, optical-fiber modal interferometer, and optical-fiber Fabry–Perot interferometer pH sensors with respect to dynamic range width, linearity as well as response and recovery times. We observed that the proposed sensing systems have better sensing abilities than the above-mentioned pH sensors. PMID:27834865

Transistor Clamped Five-Level Inverter using Non-Inverting Double Reference Single Carrier PWM Technique for photovoltaic applications

DEFF Research Database (Denmark)

Bhaskar, Mahajan Sagar; Padmanaban, Sanjeevikumar; Fedák, Viliam

2017-01-01

in output waveform. Under-modulation (modulation Index = 0.85), unity (modulation Index =1) and over-modulation (modulation Index = 1.25) PWM signal is obtained to drive control switches. Simulation results will confirm the functionality, design and operation of the proposed MLI and NIDRSC PWM Technique....

Control Strategy of PWM Rectifiers Connected to Unbalanced Grids

Czech Academy of Sciences Publication Activity Database

Bejvl, Martin; Švec, J.; Tlustý, J.; Valouch, V.

-, č. 11 (2013) ISSN 2172-038X. [International Conference on Renewable Energies and Power Quality (ICREPQ´13). Bilbao, 20.03.2013-22.03.2013] Institutional support: RVO:61388998 Keywords : electric power system * PWM rectifier * dc voltage ripple Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

Take control of font problems in Leopard

CERN Document Server

Zardetto, Sharon

2009-01-01

Are you suffering from mysterious font problems using Microsoft Office, the Adobe Creative Suite, or other programs in Mac OS X Leopard? Help is at hand, with troubleshooting steps and real-world advice that help you solve problems fast. If you've experienced seemingly inexplicable trouble with characters displaying incorrectly, being unable to type a particular character, fonts missing from Font menus, Font Book crashing, or Character Palette misbehaving, turn to font expert Sharon Zardetto for help. Read this ebook to find the answers to questions such as: Where do fonts belong on my hard

Research on Single-Phase PWM Converter with Reverse Conducting IGBT Based on Loss Threshold Desaturation Control

Directory of Open Access Journals (Sweden)

Xianjin Huang

2017-11-01

Full Text Available In the application of vehicle power supply and distributed power generation, there are strict requirements for the pulse width modulation (PWM converter regarding power density and reliability. When compared with the conventional insulated gate bipolar transistor (IGBT module, the Reverse Conducting-Insulated Gate Bipolar Transistor (RC-IGBT with the same package has a lower thermal resistance and higher current tolerance. By applying the gate desaturation control, the reverse recovery loss of the RC-IGBT diode may be reduced. In this paper, a loss threshold desaturation control method is studied to improve the output characteristics of the single-phase PWM converter with a low switching frequency. The gate desaturation control characteristics of the RC-IGBT’s diode are studied. A proper current limit is set to avoid the ineffective infliction of the desaturation pulse, while the bridge arm current crosses zero. The expectation of optimized loss decrease is obtained, and the better performance for the RC-IGBTs of the single-phase PWM converter is achieved through the optimized desaturation pulse distribution. Finally, the improved predictive current control algorithm that is applied to the PWM converter with RC-IGBTs is simulated, and is operated and tested on the scaled reduced power platform. The results prove that the gate desaturation control with the improved predictive current algorithm may effectively improve the RC-IGBT’s characteristics, and realize the stable output of the PWM converter.

Parallel implementation of DNA sequences matching algorithms using PWM on GPU architecture.

Science.gov (United States)

Sharma, Rahul; Gupta, Nitin; Narang, Vipin; Mittal, Ankush

2011-01-01

Positional Weight Matrices (PWMs) are widely used in representation and detection of Transcription Factor Of Binding Sites (TFBSs) on DNA. We implement online PWM search algorithm over parallel architecture. A large PWM data can be processed on Graphic Processing Unit (GPU) systems in parallel which can help in matching sequences at a faster rate. Our method employs extensive usage of highly multithreaded architecture and shared memory of multi-cored GPU. An efficient use of shared memory is required to optimise parallel reduction in CUDA. Our optimised method has a speedup of 230-280x over linear implementation on GPU named GeForce GTX 280.

Analysis of Peak-to-Peak Current Ripple Amplitude in Seven-Phase PWM Voltage Source Inverters

Directory of Open Access Journals (Sweden)

Gabriele Grandi

2013-08-01

Full Text Available Multiphase systems are nowadays considered for various industrial applications. Numerous pulse width modulation (PWM schemes for multiphase voltage source inverters with sinusoidal outputs have been developed, but no detailed analysis of the impact of these modulation schemes on the output peak-to-peak current ripple amplitude has been reported. Determination of current ripple in multiphase PWM voltage source inverters is important for both design and control purposes. This paper gives the complete analysis of the peak-to-peak current ripple distribution over a fundamental period for multiphase inverters, with particular reference to seven-phase VSIs. In particular, peak-to-peak current ripple amplitude is analytically determined as a function of the modulation index, and a simplified expression to get its maximum value is carried out. Although reference is made to the centered symmetrical PWM, being the most simple and effective solution to maximize the DC bus utilization, leading to a nearly-optimal modulation to minimize the RMS of the current ripple, the analysis can be readily extended to either discontinuous or asymmetrical modulations, both carrier-based and space vector PWM. A similar approach can be usefully applied to any phase number. The analytical developments for all different sub-cases are verified by numerical simulations.

Power Electronic Transformer based Three-Phase PWM AC Drives

Science.gov (United States)

Basu, Kaushik

A Transformer is used to provide galvanic isolation and to connect systems at different voltage levels. It is one of the largest and most expensive component in most of the high voltage and high power systems. Its size is inversely proportional to the operating frequency. The central idea behind a power electronic transformer (PET) also known as solid state transformer is to reduce the size of the transformer by increasing the frequency. Power electronic converters are used to change the frequency of operation. Steady reduction in the cost of the semiconductor switches and the advent of advanced magnetic materials with very low loss density and high saturation flux density implies economic viability and feasibility of a design with high power density. Application of PET is in generation of power from renewable energy sources, especially wind and solar. Other important application include grid tied inverters, UPS e.t.c. In this thesis non-resonant, single stage, bi-directional PET is considered. The main objective of this converter is to generate adjustable speed and magnitude pulse width modulated (PWM) ac waveforms from an ac or dc grid with a high frequency ac link. The windings of a high frequency transformer contains leakage inductance. Any switching transition of the power electronic converter connecting the inductive load and the transformer requires commutation of leakage energy. Commutation by passive means results in power loss, decrease in the frequency of operation, distortion in the output voltage waveform, reduction in reliability and power density. In this work a source based partially loss-less commutation of leakage energy has been proposed. This technique also results in partial soft-switching. A series of converters with novel PWM strategies have been proposed to minimize the frequency of leakage inductance commutation. These PETs achieve most of the important features of modern PWM ac drives including 1) Input power factor correction, 2) Common

A DEMODULATOR OF PWM SIGNALS GENERATED FOR A DIGITAL ACCELEROMETER IS DEVELOPED USING A MICROCONTROLLER UN DEMODULADOR DE SEÑALES PWM GENERADAS POR UN ACELERÓMETRO DIGITAL ES DESARROLLADO USANDO UN MICROCONTROLADOR

Directory of Open Access Journals (Sweden)

Eduardo Pérez Lobato

2006-08-01

Full Text Available This paper presents the use of a microcontroller to demodulate two Pulse Width Modulated (PWM signals which are being generated by a digital accelerometer, to obtain their pulse widths and transmit them serially to a parallel port of a general purpose computer.Esta publicación presenta el uso de un microcontrolador para demodular dos señales PWM que están siendo generadas por un acelerómetro digital, obtener sus anchos y enviarlas en forma serial al puerto paralelo de un computador de propósitos generales.

A high efficiency PWM CMOS class-D audio power amplifier

Energy Technology Data Exchange (ETDEWEB)

Zhu Zhangming; Liu Lianxi; Yang Yintang [Institute of Microelectronics, Xidian University, Xi' an 710071 (China); Lei Han, E-mail: zmyh@263.ne [Xi' an Power-Rail Micro Co., Ltd, Xi' an 710075 (China)

2009-02-15

Based on the difference close-loop feedback technique and the difference pre-amp, a high efficiency PWM CMOS class-D audio power amplifier is proposed. A rail-to-rail PWM comparator with window function has been embedded in the class-D audio power amplifier. Design results based on the CSMC 0.5 mum CMOS process show that the max efficiency is 90%, the PSRR is -75 dB, the power supply voltage range is 2.5-5.5 V, the THD+N in 1 kHz input frequency is less than 0.20%, the quiescent current in no load is 2.8 mA, and the shutdown current is 0.5 muA. The active area of the class-D audio power amplifier is about 1.47 x 1.52 mm{sup 2}. With the good performance, the class-D audio power amplifier can be applied to several audio power systems.

A high efficiency PWM CMOS class-D audio power amplifier

International Nuclear Information System (INIS)

Zhu Zhangming; Liu Lianxi; Yang Yintang; Lei Han

2009-01-01

Based on the difference close-loop feedback technique and the difference pre-amp, a high efficiency PWM CMOS class-D audio power amplifier is proposed. A rail-to-rail PWM comparator with window function has been embedded in the class-D audio power amplifier. Design results based on the CSMC 0.5 μm CMOS process show that the max efficiency is 90%, the PSRR is -75 dB, the power supply voltage range is 2.5-5.5 V, the THD+N in 1 kHz input frequency is less than 0.20%, the quiescent current in no load is 2.8 mA, and the shutdown current is 0.5 μA. The active area of the class-D audio power amplifier is about 1.47 x 1.52 mm 2 . With the good performance, the class-D audio power amplifier can be applied to several audio power systems.

A high efficiency PWM CMOS class-D audio power amplifier

Science.gov (United States)

Zhangming, Zhu; Lianxi, Liu; Yintang, Yang; Han, Lei

2009-02-01

Based on the difference close-loop feedback technique and the difference pre-amp, a high efficiency PWM CMOS class-D audio power amplifier is proposed. A rail-to-rail PWM comparator with window function has been embedded in the class-D audio power amplifier. Design results based on the CSMC 0.5 μm CMOS process show that the max efficiency is 90%, the PSRR is -75 dB, the power supply voltage range is 2.5-5.5 V, the THD+N in 1 kHz input frequency is less than 0.20%, the quiescent current in no load is 2.8 mA, and the shutdown current is 0.5 μA. The active area of the class-D audio power amplifier is about 1.47 × 1.52 mm2. With the good performance, the class-D audio power amplifier can be applied to several audio power systems.

Elimination of output voltage oscillations in DC-DC converter using PWM with PI controller

Directory of Open Access Journals (Sweden)

Sreenivasappa Veeranna Bhupasandra

2010-01-01

Full Text Available In this paper the SIMULINK model of a PWM controlled DC-DC converter is modeled using switching function concept to control the speed of the DC motor. The presence of the voltage oscillation cycles due to higher switching frequency in the DC-DC converter is identified. The effect of these oscillations on the output voltage of the converter, Armature current, Developed torque and Speed of the DC motor is analyzed. In order to minimize the oscillation cycles the PI controller is proposed in the PWM controller.

Font generation of personal handwritten Chinese characters

Science.gov (United States)

Lin, Jeng-Wei; Wang, Chih-Yin; Ting, Chao-Lung; Chang, Ray-I.

2014-01-01

Today, digital multimedia messages have drawn more and more attention due to the great achievement of computer and network techniques. Nevertheless, text is still the most popular media for people to communicate with others. Many fonts have been developed so that product designers can choose unique fonts to demonstrate their idea gracefully. It is commonly believed that handwritings can reflect one's personality, emotion, feeling, education level, and so on. This is especially true in Chinese calligraphy. However, it is not easy for ordinary users to customize a font of their personal handwritings. In this study, we performed a process reengineering in font generation. We present a new method to create font in a batch mode. Rather than to create glyphs of characters one by one according to their codepoints, people create glyphs incrementally in an on-demand manner. A Java Implementation is developed to read a document image of user handwritten Chinese characters, and make a vector font of these handwritten Chinese characters. Preliminary experiment result shows that the proposed method can help ordinary users create their personal handwritten fonts easily and quickly.

The PWM strategies of grid-connected distributed generation active NPC inverters

DEFF Research Database (Denmark)

Ma, Lin; Xinmin, Jin; Kerekes, Tamas

2009-01-01

The Neutral Point Clamped topology due to high efficiency, low leakage current and EMI, its integration is widely used in the distributed generation (DG) systems. However the main disadvantage of the NPC inverter is given by an unequal distribution of the losses in the semiconductor devices, which...... leads to an unequal distribution of temperature. By using the Active NPC topology, the power losses distribution problem is alleviated. The modulation strategy is a key issue for losses distribution in this topology. In this paper two known strategies are discussed and a new proposed PWM strategy......, namely the Adjustable Losses Distribution (ALD) PWM strategy is proposed for better losses distribution in the Active NPC (ANPC) topology. Simulations using Simulink and the PLECS toolbox have been done for evaluating efficiency of different NPC topologies and some experimental results are presented...

Instant HTML5 fonts and typography

CERN Document Server

Jaouher, K

2013-01-01

Filled with practical, step-by-step instructions and clear explanations for the most important and useful tasks. Written as practical recipes, Instant HTML5 Fonts and Typography How-to will enable you to use custom fonts with outstanding effects.This book is great for both professional and amateur HTML and CSS developers who are looking to use fonts in order to enhance interface design. Familiarity with JavaScript is assumed.

Development of a current-type PWM converter with high power factor. 1

International Nuclear Information System (INIS)

Miura, Yushi; Matsukawa, Makoto; Miyachi, Kengo; Kimura, Toyoaki

1998-01-01

A power supply system for superconducting poloidal field coils of a next generation tokamak-type fusion device can be operated on the relatively low voltage for the duration of discharge except the plasma initiation. In the case of the conventional phase-controlled thyristor converters are adopted in such a system, the input power factor would be low in average, and a reactive power fluctuation caused by the change of DC output voltage may produce serious effects on the commercial transmission line. From the above viewpoint, a current-type PWM (Pulse Width Modulation) converter, which can work with the power factor of unity for the input power, is regarded as one of the promising candidates of the converters for the power supplies of next generation fusion devices. Hence, a 100kW-class current-type PWM converter has been developed by using IGBT (Insulated Gate Bipolar Transistor) as switching devices. In this development, the basic performance has been preliminary investigated whether this converter is applicable to the power supply for the next generation fusion device. In addition, two different PWM control methods were examined whether these methods can realize a unit power factor and suppress the transient oscillation of converter input current at the same time in case that the reference of DC output current is changed rapidly. (author)

Shunt PWM advanced var compensators based on voltage source inverters for Facts applications

Energy Technology Data Exchange (ETDEWEB)

Barbosa, Pedro G; Misaka, Isamu; Watanabe, Edson H [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia

1994-12-31

Increased attention has been given to improving power system operation. This paper presents modeling, analysis and design of reactive shunt power compensators based on PWM-Voltage Source Inverters (Pulse Width Modulation -Voltage Source Inverters). (Pulse Width Modulation - Voltage Source Inverters). The control algorithm is based on new concepts of instantaneous active and reactive power theory. The objective is to show that with a small capacitor in the side of a 3-phase PWM-VSI it is possible to synthesize a variable reactive (capacitive or inductive) device. Design procedures and experimental results are presented. The feasibility of this method was verified by digital simulations and measurements on a small scale model. (author) 9 refs., 12 figs.

The analysis of ink jet printed eco-font efficiency

Directory of Open Access Journals (Sweden)

Rastko Milošević

2016-07-01

Full Text Available Utilization of eco-font for office printing is one of sustainable, “green” printing concepts, which besides obvious economic benefits, as a result has a certain effect on environmental sustainability as well. The fundamental problem that this practice faces is decreased quality of text printed using eco-fonts comparing to those printed with regular fonts. The aim of this research is eco-font efficiency estimation, i.e. determination of toner usage reduction level of ink jet printed documents typed with this font type, as well as estimation of the extent humans perceive differences between text printed with eco-font and the one printed by its „non-eco“ equivalent. Combining instrumental measuring method and digital image analysis, it was found that this simple principle (eco-font utilization enables substantial toner usage reduction for an ink jet printing system, while visual test showed that visual experience of text printed using eco-font is sufficient. In addition, awareness of benefits that eco-font utilization brings, change users’ attitude towards eco-font quality.

Installing fonts in LaTeX a user's experience

NARCIS (Netherlands)

Hanssen, F.T.Y.

2003-01-01

This paper presents a user's experience with installing fonts for use in LaTeX. It will be shown that it is not hard to make a standard Type 1 font work, if you use modern font installation software for LaTeX. All the steps necessary to install the example fonts will be shown. The example fonts used

GENETIC ALGORITHM BASED SOLUTION IN PWM CONVERTER SWITCHING FOR VOLTAGE SOURCE INVERTER FEEDING AN INDUCTION MOTOR DRIVE

Directory of Open Access Journals (Sweden)

V. Jegathesan

2017-11-01

Full Text Available This paper presents an efficient and reliable Genetic Algorithm based solution for Selective Harmonic Elimination (SHE switching pattern. This method eliminates considerable amount of lower order line voltage harmonics in Pulse Width Modulation (PWM inverter. Determination of pulse pattern for the elimination of some lower order harmonics of a PWM inverter necessitates solving a system of nonlinear transcendental equations. Genetic Algorithm is used to solve nonlinear transcendental equations for PWM-SHE. Many methods are available to eliminate the higher order harmonics and it can be easily removed. But the greatest challenge is to eliminate the lower order harmonics and this is successfully achieved using Genetic Algorithm without using Dual transformer. Simulations using MATLABTM and Powersim with experimental results are carried out to validate the solution. The experimental results show that the harmonics up to 13th were totally eliminated.

Born Broken: Fonts and Information Loss in Legacy Digital Documents

Directory of Open Access Journals (Sweden)

Geoffrey Brown

2011-03-01

Full Text Available For millions of legacy documents, correct rendering depends upon resources such as fonts that are not generally embedded within the document structure. Yet there is a significant risk of information loss due to missing or incorrectly substituted fonts. Large document collections depend on thousands of unique fonts not available on a common desktop workstation, which typically has between 100 and 200 fonts. Silent substitution of fonts, performed by applications such as Microsoft Office, can yield poorly rendered documents. In this paper we use a collection of 230,000 Word documents to assess the difficulty of matching font requirements with a database of fonts. We describe the identifying information contained in common font formats, font requirements stored in Word documents, the API provided by Windows to support font requests by applications, the documented substitution algorithms used by Windows when requested fonts are not available, and the ways in which support software might be used to control font substitution in a preservation environment.

The harmonic composition of the output voltage of a rectifier unit with a PWM voltage booster converter.

OpenAIRE

ПАНЧЕНКО, В В

2015-01-01

The author investigates a rectifier unit constructed on the basis of cascade connection of the main non-controlled m-pulse rectifier and PWM voltage booster converter. The research presents the analysis of the harmonic composition of the output voltage of a rectifier unit with a PWM voltage booster converter on completely controlled keys. The dependence of the relative harmonic amplitude on the commutation corner is defined. The estimation of a rectifier unit electromagnetic compatibility wit...

Three Phase Six-Switch PWM Buck Rectifier with Power Factor Improvement

DEFF Research Database (Denmark)

Zafar Ullah Khan, M; Mohsin Naveed, M.; Hussain, Dil Muhammad Akbar

2013-01-01

Conventional Phase Controlled Rectifier injects low order current harmonics into the AC mains. Large size filtering components are required to attenuate these harmonics. In this paper, Three Phase Six-Switch PWM Buck Rectifier[1] is presented which operates at nearly unity power factor and provides...

Application of digital PWM technology in current transducers

International Nuclear Information System (INIS)

Liu Huifang; Hu Zhimin; Li Rui

2012-01-01

With the development of DSP technology and mature use of PID technology,, a new program for DC or AC signal measurement is proposed. Combined with the DSP chip timer module and PID algorithm, PWM signals are generated to control the feedback circuit for the compensation current. Finally the measured current value can be obtained according to the ampere-turns compensation current and the measured current. Studies have shown that this technology enables new current transducers have high stability. (authors)

Stator insulation systems for medium voltage PWM drives fed motors

International Nuclear Information System (INIS)

Gao, G.; Chen, W.

2005-01-01

This paper presents the partial results of a research project that studied the impact of medium voltage PWM ASD (adjustable speed drives) on motor stator insulation system. The findings from this study/ investigation have aided designers to improve the robustness of the insulation system used for ASD-fed motors, based on accelerated laboratory tests. (author)

Interleaved Boost-Half-Bridge Dual–Input DC-DC Converter with a PWM plus Phase-Shift Control for Fuel Cell Applications

DEFF Research Database (Denmark)

Zhang, Zhe; Andersen, Michael A. E.

2013-01-01

This paper presents an isolated dual-input DC-DC converter with a PWM plus phase-shift control for fuel cell hybrid energy systems. The power switches are controlled by phase shifted PWM signals with a variable duty cycle, and thus the two input voltages as well as the output voltage can...

Microcontroller based PWM controlled four switch three phase inverter fed induction motor drive

Directory of Open Access Journals (Sweden)

Mohanty Kant Nalin

2010-01-01

Full Text Available This paper presents PIC microcontroller based PWM inverter controlled four switch three phase inverter (FSTPI fed Induction Motor drive. The advantage of this inverter that uses of 4 switches instead of conventional 6 switches is lesser switching losses, lower electromagnetic interference (EMI, less complexity of control algorithms and reduced interface circuits. Simulation and experimental work are carried out and results presented to demonstrate the feasibility of the proposed approach. Simulation is carried out using MATLAB SIMULINK and in the experimental work a prototype model is built to verify the simulation results. PIC microcontroller (PIC 16F877A is used to generate the PWM pulses for FSTPI to drive the 0.5 hp 3-phase Induction Motor.

Step-down switched-capacitor quasi-resonant PWM converter with continuous conversion ratio

NARCIS (Netherlands)

Turhan, M.; Hendrix, M.A.M.; Duarte, J.L.

2015-01-01

Inherent disadvantages of conventional switched-capacitor converters (SCC) are their discrete conversion ratio and inefficient energy transfer. In order to soften these downsides, a step-down switched-capacitor quasi-resonant PWM converter is proposed. The operation modes and steady-state

Modeling and the analysis of control logic for a digital PWM controller based on a nano electronic single electron transistor

Directory of Open Access Journals (Sweden)

Rathnakannan Kailasam

2008-01-01

Full Text Available This paper describes the modelling and the analysis of control logic for a Nano-Device- based PWM controller. A comprehensive simple SPICE schematic model for Single Electron transistor has been proposed. The operation of basic Single Electron Transistor logic gates and SET flip flops were successfully designed and their performances analyzed. The proposed design for realizing the logic gates and flip-flops is used in constructing the PWM controller utilized for switching the buck converter circuit. The output of the converter circuit is compared with reference voltage, and when the error voltage and the reference are matched the latch is reset so as to generate the PWM signal. Due to the simplicity and accuracy of the compact model, the simulation time and speed are much faster, which makes it potentially applicable in large-scale circuit simulation. This study confirms that the SET-based PWM controller is small in size, consumes ultra low power and operates at high speeds without compromising any performance. In addition these devices are capable of measuring charges of extremely high sensitivity.

An improved fault-tolerant control scheme for PWM inverter-fed induction motor-based EVs.

Science.gov (United States)

Tabbache, Bekheïra; Benbouzid, Mohamed; Kheloui, Abdelaziz; Bourgeot, Jean-Matthieu; Mamoune, Abdeslam

2013-11-01

This paper proposes an improved fault-tolerant control scheme for PWM inverter-fed induction motor-based electric vehicles. The proposed strategy deals with power switch (IGBTs) failures mitigation within a reconfigurable induction motor control. To increase the vehicle powertrain reliability regarding IGBT open-circuit failures, 4-wire and 4-leg PWM inverter topologies are investigated and their performances discussed in a vehicle context. The proposed fault-tolerant topologies require only minimum hardware modifications to the conventional off-the-shelf six-switch three-phase drive, mitigating the IGBTs failures by specific inverter control. Indeed, the two topologies exploit the induction motor neutral accessibility for fault-tolerant purposes. The 4-wire topology uses then classical hysteresis controllers to account for the IGBT failures. The 4-leg topology, meanwhile, uses a specific 3D space vector PWM to handle vehicle requirements in terms of size (DC bus capacitors) and cost (IGBTs number). Experiments on an induction motor drive and simulations on an electric vehicle are carried-out using a European urban driving cycle to show that the proposed fault-tolerant control approach is effective and provides a simple configuration with high performance in terms of speed and torque responses. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

A Review on Direct Power Control for Applications to Grid Connected PWM Converters

Directory of Open Access Journals (Sweden)

T. A. Trivedi

2015-08-01

Full Text Available The Direct Power Control strategy has become popular as an alternative to the conventional vector oriented control strategy for grid connected PWM converters. In this paper, Direct Power Control as applied to various applications of grid connected converters is reviewed. The Direct Power Control for PWM rectifiers, Grid Connected DC/AC inverters applications such as renewable energy sources interface, Active Power Filters, Doubly Fed Induction Generators and AC-DC-AC converters are discussed. Control strategies such as Look-Up table based control, predictive control, Virtual Flux DPC, Model based DPC and DPC-Space Vector Modulation are critically reviewed. The effects of various key parameters such as selection of switching vector, sampling time, hysteresis band and grid interfacing on performance of direct power controlled converters are presented.

Three-Phase High-Power and Zero-Current-Switching OBC for Plug-In Electric Vehicles

Directory of Open Access Journals (Sweden)

Cheng-Shan Wang

2015-06-01

Full Text Available In this paper, an interleaved high-power zero-current-switching (ZCS onboard charger (OBC based on the three-phase single-switch buck rectifier is proposed for application to plug-in electric vehicles (EVs. The multi-resonant structure is used to achieve high efficiency and high power density, which are necessary to reduce the volume and weight of the OBC. This study focuses on the border conditions of ZCS converting with a battery load, which means the variation ranges of the output voltage and current are very large. Furthermore, a novel hybrid control method combining pulse frequency modulation (PFM and pulse width modulation (PWM together is presented to ensure a driving frequency higher than 10 kHz, and this will reduce the unexpected inner resonant power flow and decrease the total harmonic distortion (THD of the input current under a light load at the end of the charging process. Finally, a prototype is established, and experiments are carried out. According to the experimental results, the conversion efficiency is higher than 93.5%, the THD about 4.3% and power factor (PF 0.98 under the maximum power output condition. Besides, a three-stage charging process is also carried out the experimental platform.

Progressive decrement PWM algorithm for minimum mean square error inverter output voltage

International Nuclear Information System (INIS)

Ghaeb, J.A.; Smadi, M.A.; Ababneh, M.

2011-01-01

Highlights: → The main contribution of this work is to provide a better performance for the power inverter operation. → The proposed technique splits the determined original pulse-width of an inverter operation in to many pulses. → The new approach extends the central pulse and shrinks the exterior pulses. → This is leading to an inverter output cycle close to the sinusoidal form of fewer harmonics. - Abstract: The paper proposes two modulation techniques for the power inverter. These new techniques are named progressive decrement PWM algorithm (PDPA) and progressive increment PWM algorithm (PIPA). Both techniques take the determined original pulse-width of an inverter operation and split it to many pulses. In the PDPA technique, the largest width is given to the middle pulse and the width of the boundary pulses is reduced progressively starting from the first boundary-pulse toward the last boundary-pulse. In the PIPA technique, there is a gradual increment instead of decrement. The two techniques have been proved that it can maintain the original pulse-width of the inverter operation. The new approach PDPA extends the central pulse and shrinks the exterior pulses, leading to an inverter output cycle close to the sinusoidal form of fewer harmonic contents. Simulation results are performed to evaluate the performances of the proposed techniques: PDPA and PIPA and to compare them with the well known methods. The main contribution of the proposed PDPA technique is that it provides a better performance for the most harmonic orders compared to the well established sinusoidal PWM technique.

Synchronised PWM Schemes for Three-level Inverters with Zero Common-mode Voltage

DEFF Research Database (Denmark)

Oleschuk, Valentin; Blaabjerg, Frede

2002-01-01

This paper presents results of analysis and comparison of novel synchronised schemes of pulsewidth modulation (PWM), applied to three-level voltage source inverters with control algorithms providing elimination of the common-mode voltage. The proposed approach is based on a new strategy of digital...

Designing legible fonts for distance reading

DEFF Research Database (Denmark)

Beier, Sofie

2016-01-01

This chapter reviews existing knowledge on distance legibility of fonts, and finds that for optimal distance reading, letters and numbers benefit from relative wide shapes, open inner counters and a large x-height; fonts should further be widely spaced, and the weight should not be too heavy or t...

A ZVT–ZCT PWM synchronous buck converter with a simple passive auxiliary circuit for reduction of losses and efficiency enhancement

Directory of Open Access Journals (Sweden)

S. Shiva Kumar

2015-06-01

Full Text Available In this paper, a Zero-Voltage-Transition (ZVT–Zero-Current Transition (ZCT Pulse-width Modulated (PWM synchronous buck converter (SBC, with a simple passive auxiliary circuit is proposed, which reduces the stresses and improves the efficiency by pacifying the conduction losses compared to a traditional PWM converter, typically suitable for photovoltaic applications. The important design feature of ZVT–ZCT PWM SBC converters is placement of resonant components that mollifies the conduction losses. Due to the ZVT–ZCT, the resonant components with low values are used, thereby resulting in the increase of switching frequency. The ZVT–ZCT operation of the proposed converter is presented through theoretical analysis. The characteristics of the proposed converter are verified with the simulation in the PSIM co-simulated with MATLAB/SIMULINK environment and implemented experimentally.

Math Model and Calculation Analysis of Inter-harmonic of Double PWM Speed Control System in Distribution Network

Directory of Open Access Journals (Sweden)

Yang Wen-Huan

2014-11-01

Full Text Available Aiming at the problem that the distribution network voltage will fluctuate because of the inter-harmonic currents injected into the network by double PWM speed control system when regulating the speed of the asynchronous motor, we established the inter-harmonic current math model of double PWM speed control system according to switching function based on a real bridge crane. The distribution law of the inter-harmonic is got by calculating the grid-side currents and their spectrum while letting the motor run at different quadrants and frequencies. The result which is verified by simulation and experiment shows that the content of the inter harmonic currents is more than that of harmonic currents in double PWM speed control system, the frequency of the inter harmonics of the grid-side current mainly focus on the scope lower than the fundamental frequency, and when the motor runs at low frequencies, the THD of the grid-side current is high. The result has verified the reason why the voltage of a bridge crane distribution system of a deepwater port in Shanghai flickers.

Serifs and font legibility

Science.gov (United States)

Arditi, Aries; Cho, Jianna

2015-01-01

Using lower-case fonts varying only in serif size (0%, 5%, and 10% cap height), we assessed legibility using size thresholds and reading speed. Five percentage serif fonts were slightly more legible than sans serif, but the average inter-letter spacing increase that serifs themselves impose, predicts greater enhancement than we observed. RSVP and continuous reading speeds showed no effect of serifs. When text is small or distant, serifs may, then, produce a tiny legibility increase due to the concomitant increase in spacing. However, our data exhibited no difference in legibility between typefaces that differ only in the presence or absence of serifs. PMID:16099015

Power electronic converters PWM strategies and current control techniques

CERN Document Server

Monmasson, Eric

2013-01-01

A voltage converter changes the voltage of an electrical power source and is usually combined with other components to create a power supply. This title is devoted to the control of static converters, which deals with pulse-width modulation (PWM) techniques, and also discusses methods for current control. Various application cases are treated. The book is ideal for professionals in power engineering, power electronics, and electric drives industries, as well as practicing engineers, university professors, postdoctoral fellows, and graduate students.

Loss Distribution Analysis of Three-Level Active Neutral-Point-Clamped (3L-ANPC) Converter with Different PWM Strategies

DEFF Research Database (Denmark)

Zhang, Gang; Yang, Yongheng; Iannuzzo, Francesco

2016-01-01

The three-level (3L) Active Neutral-Point-Clamped (ANPC) topology has been introduced to resolve the uneven loss distribution issue in the classical 3L Neutral-Point-Clamped (NPC) topology. This Pulse-Width-Modulation (PWM) strategy is then an important means to fully explore the potential benefits...... are separated in order to improve the loss distribution among the power devices. A comparison between the proposed strategy and other major PWM strategies for the loss distribution is also carried out in this paper. Benchmarking results show that the proposed strategy has effective and superior performance...

17 CFR 232.308 - Type size and font; legibility.

Science.gov (United States)

2010-04-01

... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Type size and font; legibility. 232.308 Section 232.308 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION... § 232.308 Type size and font; legibility. Provisions relating to type size, font and other legibility...

Multi-font printed Mongolian document recognition system

Science.gov (United States)

Peng, Liangrui; Liu, Changsong; Ding, Xiaoqing; Wang, Hua; Jin, Jianming

2009-01-01

Mongolian is one of the major ethnic languages in China. Large amount of Mongolian printed documents need to be digitized in digital library and various applications. Traditional Mongolian script has unique writing style and multi-font-type variations, which bring challenges to Mongolian OCR research. As traditional Mongolian script has some characteristics, for example, one character may be part of another character, we define the character set for recognition according to the segmented components, and the components are combined into characters by rule-based post-processing module. For character recognition, a method based on visual directional feature and multi-level classifiers is presented. For character segmentation, a scheme is used to find the segmentation point by analyzing the properties of projection and connected components. As Mongolian has different font-types which are categorized into two major groups, the parameter of segmentation is adjusted for each group. A font-type classification method for the two font-type group is introduced. For recognition of Mongolian text mixed with Chinese and English, language identification and relevant character recognition kernels are integrated. Experiments show that the presented methods are effective. The text recognition rate is 96.9% on the test samples from practical documents with multi-font-types and mixed scripts.

Temperature prediction in high speed bone grinding using motor PWM signal.

Science.gov (United States)

Tai, Bruce L; Zhang, Lihui; Wang, Anthony C; Sullivan, Stephen; Wang, Guangjun; Shih, Albert J

2013-10-01

This research explores the feasibility of using motor electrical feedback to estimate temperature rise during a surgical bone grinding procedure. High-speed bone grinding is often used during skull base neurosurgery to remove cranial bone and approach skull base tumors through the nasal corridor. Grinding-induced heat could propagate and potentially injure surrounding nerves and arteries, and therefore, predicting the temperature in the grinding region would benefit neurosurgeons during the operation. High-speed electric motors are controlled by pulse-width-modulation (PWM) to alter the current input and thus maintain the rotational speed. Assuming full mechanical to thermal power conversion in the grinding process, PWM can be used as feedback for heat generation and temperature prediction. In this study, the conversion model was established from experiments under a variety of grinding conditions and an inverse heat transfer method to determine heat flux. Given a constant rotational speed, the heat conversion was represented by a linear function, and could predict temperature from the experimental data with less than 20% errors. Such results support the advance of this technology for practical application. Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.

A novel five-level optimized carrier multilevel PWM quad-inverter six-phase AC drive

DEFF Research Database (Denmark)

Sanjeevikumar, P.; Blaabjerg, F.; Wheeler, Pat

2016-01-01

A novel single carrier pulse-width modulation (PWM) for a new quad-inverter configuration for multilevel six-phase asymmetrical open-winding ac converter is proposed in this article. Modularity of the circuit consist of four standard two-level voltage source inverters (VSIs) with slight modificat......A novel single carrier pulse-width modulation (PWM) for a new quad-inverter configuration for multilevel six-phase asymmetrical open-winding ac converter is proposed in this article. Modularity of the circuit consist of four standard two-level voltage source inverters (VSIs) with slight...... modifications, i.e. one additional bi-direction switch (MOSFET/IGBT) in each phase and a link to neutral with two capacitors to generate increased output levels. Furthermore, original optimal single carrier zero-shifted five-level modulation (SCZSFM) algorithm is developed for each VSI to behave as equivalent...

SlaVaComp Fonts Converter

Directory of Open Access Journals (Sweden)

Simon Skilevic

2013-12-01

Full Text Available This paper presents a fonts converter that was developed as a part of the Freiburg project on historical corpus linguistics. The tool named SlaVaComp-Konvertierer converts Church Slavonic texts digitized with non-Unicode fonts into the Unicode format without any loss of information contained in the original file and without damage to the original formatting. It is suitable for the conversion of all idiosyncratic fonts—not only Church Slavonic—and therefore can be used not only in Palaeoslavistic, but also in all historical and philological studies.

A High-Precision Control for a ZVT PWM Soft-Switching Inverter to Eliminate the Dead-Time Effect

Directory of Open Access Journals (Sweden)

Baoquan Kou

2016-07-01

Full Text Available Attributing to the advantages of high efficiency, low electromagnetic interference (EMI noise and closest to the pulse-width-modulation (PWM converter counterpart, zero-voltage-transition (ZVT PWM soft-switching inverters are very suitable for high-performance applications. However, the conventional control algorithms intended for high efficiency generally results in voltage distortion. Thus, this paper, for the first time, proposes a high-precision control method to eliminate the dead-time effect through controlling the auxiliary current in the auxiliary resonant snubber inverter (ARSI, which is a typical ZVT PWM inverter. The dead-time effect of ARSI is analyzed, which is distinguished from hard-switching inverters. The proposed high-precision control is introduced based on the investigation of dead-time effect. A prototype was developed to verify the effectiveness of the proposed control. The experimental results shows that the total harmonic distortion (THD of the output current of the ARSI can be reduced compared with that of the hard-switching inverter, because the blanking delay error is eliminated. The quality of the output current and voltage can be further improved by utilizing the proposed control method.

Combined resonant tank capacitance and pulse frequency modulation control for ZCS-SR inverter-fed high voltage DC power supply

International Nuclear Information System (INIS)

Lee, S S; Iqbal, S; Kamarol, M

2011-01-01

Conventional pulse frequency modulated (PFM) zero current switching (ZCS) series resonant (SR) inverter fed high voltage dc power supplies have nearly zero switching loss. However, they have limitations of poor controllability at light loads and large output voltage ripple at low switching frequencies. To address these problems, this paper proposes a combined resonant tank capacitance and pulse frequency modulation based control approach. For the realization of the proposed control approach, the tank circuit of the resonant inverter is made up of several resonant capacitors that are switched into or out of the tank circuit by electromechanical switches. The output voltage of the converter is regulated by digitally modulating the resonant tank capacitance and narrowly varying the switching frequency. The proposed control scheme has several features, namely a wide range of controllability even at light loads, less output voltage ripple, and less current stress on the inverter's power switches at light loads. Therefore, the proposed control approach alleviates most of the problems associated with conventional PFM. Experimental results obtained from a scaled down laboratory prototype are presented to verify the effectiveness of the proposed system.

Tipe Dry Cell dan Wet Cell berdimensi 80 x 80 mm dengan Penambahan PWM E-3 FF (1 kHz

Directory of Open Access Journals (Sweden)

Yanur Arzaqa Ghiffari

2013-09-01

Full Text Available Ketersediaan bahan bakar minyak semakin terbatas dan hasil pembakarannya berdampak pada pencemaran lingkungan, salah satu solusinya dengan memanfaatkan gas HHO pada kendaraan bermotor. Penelitian dengan sistem direct connection, temperatur mencapai lebih dari 90oC menyebabkan  generator HHO menjadi rusak dan meleleh, maka penelitian ini menambahan alat untuk mengkontrol besarnya arus, frekuensi, dan duty cycle. Pengembangan generator HHO menggunakan tipe kering (dry cell dan tipe basah (wet cell dengan penambahan PWM (Pulse Width Modulation E-3 Fixed Frequency 1 kHz divariasikan berupa duty cycle: 20%, 40%, 60%, 80%  dan direct connection. Pengujian dilakukan di Laboratorium Teknik Pembakaran dan Bahan Bakar - Teknik Mesin ITS.  Dari hasil penelitian didapatkan karakteristik unjuk kerja terbaik pada kedua tipe generator HHO dengan penambahan PWM. Nilai arus dan tegangan lebih stabil dibandingkan dengan tanpa penambahan PWM (direct connection, namun arus cenderung meningkat seiring dengan kenaikan temperatur mencapai 70oC. Efisiensi terbaik pada generator tipe wet dengan duty cycle 80%,  yaitu 27,7 %.

A PWM Controller of a Full Bridge Single-Phase Synchronous Inverter for Micro-Grid System

Science.gov (United States)

Rahman, Tawfikur; Motakabber, S. M. A.; Ibrahimy, M. I.; Raghib, Aliza ‘Aini Binti Md Ralib@ Md

2017-12-01

Nowadays, microgrid system technology is becoming popular for small area power management systems. It is essential to be less harmonic-distortion and high efficiency of the inverter for microgrid applications. Pulse width modulation (PWM) controller is a conventional switching control technique which is suitable to use in the microgrid connected power inverter system. The control method and algorithm of this technique are challenging, and different approaches are required to avoid the complexity for a customized solution of the microgrid application. This paper proposes a comparative analysis of different controller and their operational methods. A PWM controller is used to reduce the ripple voltage noise while a continuous current mode provides a small output ripple which gives steady-state error as zero on fundamental and cutoff frequency. To reduce the ripple current, higher frequency harmonic distortion, switching loss and phase noise, LC low pass filter is used on either side of input and output terminals. The proposed inverter is designed by MATLAB 2016a simulation software. A balanced load resistance (RL = 20.5 Ω) of star configuration and a dual input DC voltage of ± 35V are considered. In this design, the circuit parameters, the fundamental frequency of 50 Hz, the PWM duty cycle of 95%, the cutoff frequency of the switching controller of 33 kHz are considered. The inverter in this paper exhibits THD of 0.44% and overall efficiency approximately of 98%. The proposed inverter is expected to be suitable for microgrid applications.

Dyslexie font does not benefit reading in children with or without dyslexia.

Science.gov (United States)

Kuster, Sanne M; van Weerdenburg, Marjolijn; Gompel, Marjolein; Bosman, Anna M T

2017-12-04

In two experiments, the claim was tested that the font "Dyslexie", specifically designed for people with dyslexia, eases reading performance of children with (and without) dyslexia. Three questions were investigated. (1) Does the Dyslexie font lead to faster and/or more accurate reading? (2) Do children have a preference for the Dyslexie font? And, (3) is font preference related to reading performance? In Experiment 1, children with dyslexia (n = 170) did not read text written in Dyslexie font faster or more accurately than in Arial font. The majority preferred reading in Arial and preference was not related to reading performance. In Experiment 2, children with (n = 102) and without dyslexia (n = 45) read word lists in three different font types (Dyslexie, Arial, Times New Roman). Words written in Dyslexie font were not read faster or more accurately. Moreover, participants showed a preference for the fonts Arial and Times New Roman rather than Dyslexie, and again, preference was not related to reading performance. These experiments clearly justify the conclusion that the Dyslexie font neither benefits nor impedes the reading process of children with and without dyslexia.

Highly Sensitive Temperature Sensors Based on Fiber-Optic PWM and Capacitance Variation Using Thermochromic Sensing Membrane

Directory of Open Access Journals (Sweden)

Md. Rajibur Rahaman Khan

2016-07-01

Full Text Available In this paper, we propose a temperature/thermal sensor that contains a Rhodamine-B sensing membrane. We applied two different sensing methods, namely, fiber-optic pulse width modulation (PWM and an interdigitated capacitor (IDC-based temperature sensor to measure the temperature from 5 °C to 100 °C. To the best of our knowledge, the fiber-optic PWM-based temperature sensor is reported for the first time in this study. The proposed fiber-optic PWM temperature sensor has good sensing ability; its sensitivity is ~3.733 mV/°C. The designed temperature-sensing system offers stable sensing responses over a wide dynamic range, good reproducibility properties with a relative standard deviation (RSD of ~0.021, and the capacity for a linear sensing response with a correlation coefficient of R2 ≈ 0.992 over a wide sensing range. In our study, we also developed an IDC temperature sensor that is based on the capacitance variation principle as the IDC sensing element is heated. We compared the performance of the proposed temperature-sensing systems with different fiber-optic temperature sensors (which are based on the fiber-optic wavelength shift method, the long grating fiber-optic Sagnac loop, and probe type fiber-optics in terms of sensitivity, dynamic range, and linearity. We observed that the proposed sensing systems have better sensing performance than the above-mentioned sensing system.

Active and reactive power control of a current-source PWM-rectifier using space vectors

Energy Technology Data Exchange (ETDEWEB)

Salo, M.; Tuusa, H. [Tampere University of Technology (Finland). Department of Electrical Engineering, Power Electronics

1997-12-31

In this paper the current-source PWM-rectifier with active and reactive power control is presented. The control system is realized using space vector methods. Also, compensation of the reactive power drawn by the line filter is discussed. Some simulation results are shown. (orig.) 8 refs.

Character feature integration of Chinese calligraphy and font

Science.gov (United States)

Shi, Cao; Xiao, Jianguo; Jia, Wenhua; Xu, Canhui

2013-01-01

A framework is proposed in this paper to effectively generate a new hybrid character type by means of integrating local contour feature of Chinese calligraphy with structural feature of font in computer system. To explore traditional art manifestation of calligraphy, multi-directional spatial filter is applied for local contour feature extraction. Then the contour of character image is divided into sub-images. The sub-images in the identical position from various characters are estimated by Gaussian distribution. According to its probability distribution, the dilation operator and erosion operator are designed to adjust the boundary of font image. And then new Chinese character images are generated which possess both contour feature of artistical calligraphy and elaborate structural feature of font. Experimental results demonstrate the new characters are visually acceptable, and the proposed framework is an effective and efficient strategy to automatically generate the new hybrid character of calligraphy and font.

Improving dynamic performances of PWM-driven servo-pneumatic systems via a novel pneumatic circuit.

Science.gov (United States)

Taghizadeh, Mostafa; Ghaffari, Ali; Najafi, Farid

2009-10-01

In this paper, the effect of pneumatic circuit design on the input-output behavior of PWM-driven servo-pneumatic systems is investigated and their control performances are improved using linear controllers instead of complex and costly nonlinear ones. Generally, servo-pneumatic systems are well known for their nonlinear behavior. However, PWM-driven servo-pneumatic systems have the advantage of flexibility in the design of pneumatic circuits which affects the input-output linearity of the whole system. A simple pneumatic circuit with only one fast switching valve is designed which leads to a quasi-linear input-output relation. The quasi-linear behavior of the proposed circuit is verified both experimentally and by simulations. Closed loop position control experiments are then carried out using linear P- and PD-controllers. Since the output position is noisy and cannot be directly differentiated, a Kalman filter is designed to estimate the velocity of the cylinder. Highly improved tracking performances are obtained using these linear controllers, compared to previous works with nonlinear controllers.

Electromagnetic phenomena analysis in brushless DC motor with speed control using PWM method

Science.gov (United States)

Ciurys, Marek Pawel

2017-12-01

Field-circuit model of a brushless DC motor with speed control using PWM method was developed. Waveforms of electrical and mechanical quantities of the designed motor with a high pressure vane pump built in a rotor of the motor were computed. Analysis of electromagnetic phenomena in the system: single phase AC network - converter - BLDC motor was carried out.

Design of a High Performance Green-Mode PWM Controller IC with Smart Sensing Protection Circuits

Directory of Open Access Journals (Sweden)

Shen-Li Chen

2014-08-01

Full Text Available A design of high performance green-mode pulse-width-modulation (PWM controller IC with smart sensing protection circuits for the application of lithium-ion battery charger (1.52 V ~ 7.5 V is investigated in this paper. The protection circuits architecture of this system mainly bases on the lithium battery function and does for the system design standard of control circuit. In this work, the PWM controller will be with an automatic load sensing and judges the system operated in the operating mode or in the standby mode. Therefore, it reduces system’s power dissipation effectively and achieves the saving power target. In the same time, many protection sensing circuits such as: (1 over current protection (OCP and under current protection (UCP, (2 over voltage protection (OVP and under voltage protection (UVP, (3 loading determintion and short circuit protection (SCP, (4 over temperature protection (OTP, (5 VDD surge-spiking protection are included. Then, it has the characteristics of an effective monitoring the output loading and the harm prevention as a battery charging. Eventually, this green-mode pulse-width-modulation (PWM controller IC will be that the operation voltage is 3.3 V, the operation frequency is 0.98 MHz, and the output current range is from 454 mA to 500 mA. Meanwhile, the output convert efficiency is range from 74.8 % to 91 %, the power dissipation efficiency in green-mode is 25 %, and the operation temperature range is between -20 0C ~ 114 0C.

New PWM method and commutation strategy for HF-link converters for fuel cells and photovoltaics

DEFF Research Database (Denmark)

Ljusev, Petar; Andersen, Michael Andreas E.

2005-01-01

This paper presents a new PWM method and commutation strategy for HF-link converters, which leads to safe commutation of the load current in the output bidirectional bridge. The proposed implementation is independent of the particular HF-link converter topology and bidirectional switch selection ...

Effect of metallurgical factors on the magnetic properties of non-oriented electrical steels under PWM excitation

International Nuclear Information System (INIS)

Tanaka, T.; Yashiki, H.; Takada, S.; Sasaki, T.

1994-01-01

Magnetic properties of non-oriented electrical steel sheets under PWM voltage excitation as well as those under sinusoidal excitation have been investigated from a metallurgical point of view. The core loss under PWM excitation is slightly larger than that under sinusoidal excitation. The induction dependence of the core loss difference between the two excitation conditions changes by changing Si content and grain size. The higher the induction, the larger the core loss difference of 0.2% Si steel with small grains. In the case of higher Si steels and 0.2% Si steel with large grain sizes, however, the core loss difference at inductions over 1.3 T decreases with increasing induction. At low induction levels the core loss difference has little relationship to the grain size. On the other hand, at high induction levels this difference decreases with increasing grain size. ((orig.))

Windowed SHE-PWM of Interleaved Four-Quadrant Converters for Resonance Suppression in Traction Power Supply Systems

DEFF Research Database (Denmark)

Song, Kejian; Konstantinou, Georgios; Mingli, Wu

2017-01-01

AC electric locomotives that use a number of interleaved four-quadrant converters generate high-frequency switching harmonics which may stimulate certain resonances in traction power supply systems (TPSSs). A windowed selective harmonic elimination pulse-width modulation (SHE-PWM) method...

PERANCANGAN FONT TAPYCH BERBASIS KARAKTER VISUAL MOTIF TAPIS LAMPUNG

Directory of Open Access Journals (Sweden)

Wantoro Wantoro

2017-02-01

Full Text Available Abstrak Tapis merupakan kain khas asal Lampung yang terbuat dari tenunan benang kapas berwarna emas dan perak. Sebagai produk budaya, tapis memiliki visualisasi yang khas. Berdasarkan observasi, pemanfaatan tapis yang memiliki representasi nilai dan nilai estetika tinggi masih terbatas pada media dan waktu tertentu. Hal ini tentu saja menimbulkan kekhawatiran tentang pelestarian dan pengembangan tapis karena keterbatasan pemanfaatannya. Contoh pemanfaatan tapis yang dapat dilakukan adalah upaya eksplorasi visual kedalam bentuk produk budaya lain yang lekat dengan keseharian masyarakat. Salah satu produk budaya yang dapat dirancang adalah huruf. Huruf merupakan media komunikasi tulisan yang sebenarnya telah lama ada dan berkembang. Di Indonesia, komunikasi tulisan mayoritas  menggunakan huruf latin. Penggunaan huruf latin di Indonesia dapat dilihat mulai dari cara manual hingga sudah dilakukan secara digital. Huruf digital atau disebut dengan font saat ini banyak digunakan pada perangkat-perangkat digital/elektronik. Perkembangan desain font juga terus berkembang karena kebutuhan akan penyampaian pesan maupun kesan estetis pada suatu karya juga berkembang. Hal inilah yang kemudian menginspirasi lahirnya kemungkinan-kemungkinan bentuk visual baru font khususnya yang berbasis huruf Latin. Tapis, dengan kekayaan estetik pada visualnya dapat dijadikan sebagai inspirasi dalam menciptakan kemungkinan bentuk baru dari sebuah font yang berbasis pada bentuk huruf latin. Perpaduan visual antara tapis dan karakter huruf latin dapat menghasilkan karakteristik yang khas. Kata Kunci: Adaptasi, Font, Perancangan, Tapis, Visual Abstract Tapis from Lampung is a unique fabric made from cotton yarn woven gold and silver. As cultural products, Tapis have a typical visualization. Based on observations, the use of Tapis which has a value of representation and a high aesthetic value is still limited to the media and a certain time. This raises concerns about the

Six-Phase Vehicular Drive with Renewable DC Sources and Hybrid PWM Control of Four Inverters

DEFF Research Database (Denmark)

Oleschuk, Valentin; Ermuratskii, Vladimir; Blaabjerg, Frede

2015-01-01

The paper presents results of research of quad-inverter-based automotive system with combined scheme of PWM control of inverters, supplied by two renewable dc sources (by fuel cells and by battery). It has been shown, that hybrid switching techniques can be used successfully for control of vehicle...

A Reconfigurable Series Resonant DC-DC Converter for Wide-Input and Wide-Output Voltages

DEFF Research Database (Denmark)

Shen, Yanfeng; Wang, Huai; Qin, Zian

2017-01-01

This paper proposes a dual-bridge based LC series resonant dc-dc converter. The input inverter unit incorporates two bridge structures, i.e., a full-bridge inverter and a half-bridge inverter. For the output rectifier, it can be a full-bridge rectifier or an asymmetric half-bridge rectifier....... Different from the conventional resonant converter, a fixed-frequency PWM control is employed which makes the optimization of magnetic components easier. The primary-side switches can achieve ZVS and the secondary-side diodes turn off with ZCS. In addition, the root-mean-square (RMS) values...... of the transformer currents do not significantly vary with respect to the voltage variation. Therefore, this converter can maintain high efficiency over a wide voltage range. The topology and operating principle are firstly described. Then the dc voltage gain and the RMS current characteristics are detailed. Finally...

Self oscillating PWM modulators, a topological comparison

DEFF Research Database (Denmark)

Poulsen, Søren; Andersen, Michael Andreas E.

2004-01-01

or fs/ð range respectively, where fs is the switching frequency of the converter. For some applications this will require unacceptable high switching frequency to achieve enough control loop bandwidth for the desired dynamic performance. With self oscillating modulators, the open loop bandwidth is equal...... to fs which makes this type of modulators an excellent choice for a wide range of applications. Self oscillating PWM modulators can be made in a number of ways, either as voltage or current mode modulators, and the self oscillating behavior can be achieved either by using hysteresis control...... or by shaping the open loop function of the modulator so its gain and phase response causes a closed loop natural oscillation. The two main types of self oscillating modulators have many similarities, but differences in dynamic performance and linearity are present. The work presented is related to the author...

A ZVS PWM control strategy with balanced capacitor current for half-bridge three-level DC/DC converter

DEFF Research Database (Denmark)

Liu, Dong; Deng, Fujin; Chen, Zhe

2017-01-01

The capacitor current would be imbalanced under the conventional control strategy in the half-bridge three-level (HBTL) DC/DC converter due to the effect of the output inductance of the power supply and the input line inductance, which would affect the converter's reliability. This paper proposes...... a pulse-wide modulation (PWM) strategy composed of two operation modes for the HBTL DC/DC converter, which can realize the zero-voltage switching (ZVS) for the efficiency improvement. In addition, a capacitor current balancing control is proposed by alternating the two operation modes of the proposed ZVS...... PWM strategy, which can eliminate the current imbalance among the two input capacitors. Therefore, the proposed control strategy can improve the converter's performance and reliability in: 1) reducing the switching losses and noises of the power switches; 2) balancing the thermal stresses...

Modelling and Controller Design of Electro-Pneumatic Actuator Based on PWM

Directory of Open Access Journals (Sweden)

Behrouz Najjari

2012-07-01

Full Text Available In this paper, a nonlinear model associated to the fast switching on-off solenoid valve and pneumatic cylinder was dynamically presented. Furthermore, an investigation into the electrical, magnetic, mechanical and fluid subsystems are made. Two common control policies to track valve position, a Proportional Integrator (PI based on Pulse Width Modulation (PWM and hysteresis controllers, are investigated. To control cylinder position, a Programmable Logic Controller (PLC on a simulated unit and an experimental setup regulated with AVR microcontroller are carried out. Experimental results show effective validation to the simulation results from PLC.

Transformer-assisted PWM zero-voltage switching pole inverter with high output bandwidth applied to linear motor drives

NARCIS (Netherlands)

Myrzik, J.M.A.; Duarte, J.L.; Haardt, de P.; Vissers, J.

2002-01-01

An application of the transformer-assisted PWM zero-voltage switching pole inverter (TRAP) is described in this paper. The TRAP is based on the auxiliary resonant commutated pole inverter (ARCP), but avoids its disadvantages. This paper describes the converter functionality and its applicability

Dynamic Sliding Mode Evolution PWM Controller for a Novel High-Gain Interleaved DC-DC Converter in PV System

Directory of Open Access Journals (Sweden)

Taizhou Bei

2014-01-01

Full Text Available Considering the disadvantages of the traditional high-gain DC-DC converter such as big size, high voltage stress of switches, and large input current ripple, a novel high-gain interleaved boost converter with coupled-inductor and switched-capacitor was proposed correspondingly and the operation principle together with the steady-state analysis of this converter was also described. Besides, a new control approach-dynamic sliding mode evolution PWM controller (DSME PWM for the novel topological converter based on both dynamic evolution and sliding mode control was also presented. From the simulation results and experimental validation the proposed converter can fulfill high-gain boost, low ripple of both the input current and the output voltage. Furthermore, MPPT technique can be also achieved in a short time by simulation. The efficiency and stability of the converter proposed in this paper can be improved.

Fontes de informações do consumidor organizacional: as compras de medicamentos por hospitais

Directory of Open Access Journals (Sweden)

Paulo Fernando Burlamaqui

2008-07-01

Full Text Available http://dx.doi.org/10.5007/2175-8069.2008v10n20p163 A fonte das buscas de informação realizadas pelo consumidor organizacional pode influir decisivamente no momento da escolha do fornecedor. A compreensão de como são processadas as buscas de informações realizadas nas compras se apresenta como questão estratégica por parte de profissionais de marketing no reconhecimento das necessidades dos consumidores organizacionais. O presente estudo analisa como é efetuada a busca das fontes de informações na compra de medicamentos observando o comportamento deste consumidor, através de uma survey aplicada aos compradores dos hospitais gaúchos. O estudo desenvolvido identificou a forte utilização das fontes de informações (fontes comerciais, fontes de mídia, fontes pessoais e fontes experimentais; onde observou-se que a principal influência são as fontes comerciais. A conclusão do estudo indica também que, por sua vez, o comprador pode compreender como a sua organização (hospital se comporta diante destas variáveis.

A Harmonic Resonance Suppression Strategy for a High-Speed Railway Traction Power Supply System with a SHE-PWM Four-Quadrant Converter Based on Active-Set Secondary Optimization

Directory of Open Access Journals (Sweden)

Runze Zhang

2017-10-01

Full Text Available Pulse width modulation (PWM technology is widely used in traction converters for high-speed railways. The harmonic distribution caused by PWM is quite extensive, and increases the possibility of grid–train coupling resonance in the traction power supply system (TPSS. This paper first analyzes the mechanism of resonance, when the characteristic harmonic frequency of a four-quadrant converter (4QC current that injects into the traction grid matches the resonant frequency of the traction grid, which may result in resonance in the system. To suppress resonance, this paper adopts specific harmonic elimination–pulse width modulation (SHE-PWM technology combined with a transient direct current control strategy to eliminate the harmonics in the resonant frequency, which may suppress the grid–train coupling resonance. Due to the fact that the SHE-PWM process with multiple switching angles contains complex transcendental equations, the initial value is difficult to provide, and is difficult to solve using ordinary iterative algorithms. In this paper, an active-set secondary optimization method is used to solve the equation. The algorithm has the benefits of low dependence on initial values, fast convergence and high solution accuracy. Finally, the feasibility of the resonant suppression algorithm is verified by means of Matlab simulation.

Soft switching PWM isolated boost converter for fuel cell application

Energy Technology Data Exchange (ETDEWEB)

Rezaei, M.; Adib, E. [Isfahan Univ. of Technology, Isfahan (Iran, Islamic Republic of)

2009-07-01

This presentation introduced a newly developed soft switching, isolated boost type converter for fuel cell applications. With a simple PWM control circuit, the converter achieves zero voltage switching the main switch. Since the auxiliary circuit is soft switched, the converter can operate at high powers which make it suitable for fuel cell applications. In particular, the converter is suitable for the interface of fuel cell and inverters because of its high voltage gain and isolation between input and output sources. In addition, the input current of the converter (current drained from the fuel cell) is almost constant since it is a boost type converter. The converter was analyzed and the simulation results validate the theoretical analysis.

A new PWM algorithm for battery-source three-phase inverters

Energy Technology Data Exchange (ETDEWEB)

Chan, C.C. (Dept. of Electrical and Electronic Engineering, Univ. of Hong Kong, Pokfulam Road (HK)); Chau, K.T. (Dept. of Electrical Engineering, Hong Kong Polytechnic, Hung Hom (HK))

1991-01-01

A new PWM algorithm for battery-source three-phase inverters is described in this paper. The concept of the algorithm is to determine the pulsewidths by equating the areas of the segments of the sinusodial reference with the related output pulse areas. The algorithm is particularly suitable to handle a non-constant voltage source with good harmonic suppression. Since the pulsewidths are computable in real time with minimal storage requirement as well as compact hardware and software, it is especially suitable for single-chip microcomputer implementation. Experimental results show that the single-chip microcomputer Intel 8095-based battery-source inverter can control a 3 kW synchronous motor drive satisfactorily over a frequency range of 2 to 100Hz.

A Special Font for People with Dyslexia: Does it Work and, if so, why?

Science.gov (United States)

Marinus, Eva; Mostard, Michelle; Segers, Eliane; Schubert, Teresa M; Madelaine, Alison; Wheldall, Kevin

2016-08-01

In 2008 Christian Boer, a Dutch artist, developed a special font ("Dyslexie") to facilitate reading in children and adults with dyslexia. The font has received a lot of media attention worldwide (e.g., TheGuardian.com, Slate.com, TheAtlantic.com, USA Today, and io9.com). Interestingly, there is barely any empirical evidence for the efficacy of Dyslexie. This study aims to examine if Dyslexie is indeed more effective than a commonly used sans serif font (Arial) and, if so, whether this can be explained by its relatively large spacing settings. Participants were 39 low-progress readers who were learning to read in English. They were asked to read four different texts in four different font conditions that were all matched on letter display size (i.e., x-height), but differed in the degree to which they were matched for spacing settings. Results showed that low-progress readers performed better (i.e., read 7% more words per minute) in Dyslexie font than in standardly spaced Arial font. However, when within-word spacing and between-word spacing of Arial font was matched to that of Dyslexie font, the difference in reading speed was no longer significant. We concluded that the efficacy of Dyslexie font is not because of its specially designed letter shapes, but because of its particular spacing settings. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Power system stabilization by SMES using current-fed pwm power conditioner

International Nuclear Information System (INIS)

Ishikawa, T.; Akita, S.; Taniguchi, H.; Kosho, S.; Tanaka, T.

1988-01-01

A superconducting magnetic energy storage (SMES) unit, consisted of superconducting coil and AC/DC power conditioner, can be used to suppress various kinds of instability that may cause service interruption in electric power system as it has high controllability of input/output electric power. Power system stabilizing ability of SMES has been examined experimentally by using model power system and small SMES unit. Current-fed PWM power conditioner was used to obtain maximum stabilizing effect by controlling active and reactive power simultaneously and independently. Power conditioner configuration, operating characteristics and control scheme for power system stabilization are also described. Results from experiments show the effectiveness of SMES on power system stabilization

Metamemory and memory for a wide range of font sizes: What is the contribution of perceptual fluency?

Science.gov (United States)

Undorf, Monika; Zimdahl, Malte F

2018-04-26

Words printed in a larger 48-point font are judged to be more memorable than words printed in a smaller 18-point font, although font size does not affect actual memory. To clarify the basis of this font size effect on metamemory and memory, 4 experiments investigated how presenting words in 48 (Experiment 1) or 4 (Experiments 2 to 4) font sizes between 6 point and 500 point affected judgments of learning (JOLs) and recall performance. Response times in lexical decision tasks were used to measure perceptual fluency. In all experiments, perceptual fluency was lower for words presented in very small and very large font sizes than for words presented in intermediate font sizes. In contrast, JOLs increased monotonically with font size, even beyond the point where a large font impaired perceptual fluency. Assessments of people's metacognitive beliefs about font size revealed that the monotonic increase in JOLs was not due to beliefs masking perceptual fluency effects (Experiment 3). Also, JOLs still increased across the whole range of font sizes when perceptual fluency was made salient at study (Experiment 4). In all experiments but Experiment 4, recall performance increased with increasing font size, although to a lesser extent than JOLs. Overall, the current study supports the idea that metacognitive beliefs underlie font size effects in metamemory. As important, it reveals that people's font size beliefs have some accuracy. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Zero-Voltage Switching PWM Strategy Based Capacitor Current-Balancing Control for Half-Bridge Three-Level DC/DC Converter

DEFF Research Database (Denmark)

Liu, Dong; Deng, Fujin; Zhang, Qi

2018-01-01

The current imbalance among the two input capacitors is one of the important issues of the half-bridge threelevel (HBTL) DC/DC converter, which would affect system performance and reliability. In this paper, a zero-voltage switching (ZVS) pulse-wide modulation (PWM) strategy including two operation...

FONTES PRIMÁRIAS: SABERES EM MOVIMENTO

Directory of Open Access Journals (Sweden)

CAMPOS Edson Nascimento

1997-01-01

Full Text Available Este artigo trata as fontes primárias à luz de uma epistemologia que submete a investigação e a pesquisa à ação desconstrutora dos sujeitos: as fontes, por isso, saem da posição de "ponto primacial" para a de "ponto relacional". E, aí, a linguagem se transforma em relação de intertextualidade, pois a contradição marca o sentido da interdependência e, nisso, a significação põe a força da instabilidade na relação do sujeito com o objeto. Este, aliás, aberto à abordagem múltipla do real, integra a relação de interdisciplinaridade, e, assim, vêm surgindo, por exemplo, explicações iluminadoras com as articulações de Educação, Pedagogia, Linguagem, História.

Synchronized Scheme of Continuous Space-Vector PWM with the Real-Time Control Algorithms

DEFF Research Database (Denmark)

Oleschuk, V.; Blaabjerg, Frede

2004-01-01

This paper describes in details the basic peculiarities of a new method of feedforward synchronous pulsewidth modulation (PWM) of three-phase voltage source inverters for adjustable speed ac drives. It is applied to a continuous scheme of voltage space vector modulation. The method is based...... their position inside clock-intervals. In order to provide smooth shock-less pulse-ratio changing and quarter-wave symmetry of the voltage waveforms, special synchronising signals are formed on the boundaries of the 60 clock-intervals. The process of gradual transition from continuous to discontinuous...

Estimating return levels from maxima of non-stationary random sequences using the Generalized PWM method

Directory of Open Access Journals (Sweden)

P. Ribereau

2008-12-01

Full Text Available Since the pioneering work of Landwehr et al. (1979, Hosking et al. (1985 and their collaborators, the Probability Weighted Moments (PWM method has been very popular, simple and efficient to estimate the parameters of the Generalized Extreme Value (GEV distribution when modeling the distribution of maxima (e.g., annual maxima of precipitations in the Identically and Independently Distributed (IID context. When the IID assumption is not satisfied, a flexible alternative, the Maximum Likelihood Estimation (MLE approach offers an elegant way to handle non-stationarities by letting the GEV parameters to be time dependent. Despite its qualities, the MLE applied to the GEV distribution does not always provide accurate return level estimates, especially for small sample sizes or heavy tails. These drawbacks are particularly true in some non-stationary situations. To reduce these negative effects, we propose to extend the PWM method to a more general framework that enables us to model temporal covariates and provide accurate GEV-based return levels. Theoretical properties of our estimators are discussed. Small and moderate sample sizes simulations in a non-stationary context are analyzed and two brief applications to annual maxima of CO₂ and seasonal maxima of cumulated daily precipitations are presented.

A hard-to-read font reduces the framing effect in a large sample.

Science.gov (United States)

Korn, Christoph W; Ries, Juliane; Schalk, Lennart; Oganian, Yulia; Saalbach, Henrik

2018-04-01

How can apparent decision biases, such as the framing effect, be reduced? Intriguing findings within recent years indicate that foreign language settings reduce framing effects, which has been explained in terms of deeper cognitive processing. Because hard-to-read fonts have been argued to trigger deeper cognitive processing, so-called cognitive disfluency, we tested whether hard-to-read fonts reduce framing effects. We found no reliable evidence for an effect of hard-to-read fonts on four framing scenarios in a laboratory (final N = 158) and an online study (N = 271). However, in a preregistered online study with a rather large sample (N = 732), a hard-to-read font reduced the framing effect in the classic "Asian disease" scenario (in a one-sided test). This suggests that hard-read-fonts can modulate decision biases-albeit with rather small effect sizes. Overall, our findings stress the importance of large samples for the reliability and replicability of modulations of decision biases.

Estudo espectral em raios-X duros de fontes do tipo Z com o HEXTE/RXTE

Science.gov (United States)

D'Amico, F.; Heindl, W. A.; Rothschild, R. E.

2003-08-01

Apresentam-se os resultados de um estudo espectral em raios-X de fontes do tipo Z. As fontes do tipo Z são binárias de raios-X de baixa massa (BXBM) com campo magnético intermediário (B~109G). Esta classe de fontes é composta por apenas 6 fontes Galácticas (a saber: ScoX-1, 9, 7, CygX-2, 5 e 0). A nossa análise se concentra na faixa de raios-X duros (E ~ 20keV), até cerca de 200keV, faixa ótima de operação do telescópio "High Energy X-ray Timing Experiment" (HEXTE), um dos três telescópios de raios-X à bordo do Rossi X-ray Timing Explorer (RXTE). Nossa motivação para tal estudo, uma busca de caudas em raios-X duros em fontes do tipo Z, foi o pouco conhecimento sobre a emissão nesta faixa de energia das referidas fontes quando comparadas, por exemplo, as fontes do tipo atoll (também BXBM). Apresentam-se a análise/redução de dados e explicita-se a maneira como o HEXTE mede o ru1do de fundo. Especial atenção é direcionada a este item devido a localização das fontes do tipo Z e também ao problema de contaminação por fontes próximas. Com exceção de ScoX-1, nenhuma cauda em raios-X duros foi encontrada para as outras fontes, a despeito de resultados de detecção dessas caudas em algumas fontes pelo satélite BeppoSAX. As interpretações deste resultado serão apresentadas. Do ponto de vista deste estudo, nós deduzimos que a produção de caudas de raios-X duros em fontes do tipo Z é um processo disparado quando, pelo menos, uma condição é satisfeita: o brilho da componente térmica do espectro precisa estar acima de um certo valor limiar de ~4´1036ergs-1.

Iconographic dental typography. A dental character font for computer graphics.

Science.gov (United States)

McCormack, J

1991-06-08

The recent massive increase in available memory for microcomputers now allows multiple font faces to be stored in computer RAM memory for instant access to the screen and for printed output. Fonts can be constructed in which the characters are not just letters or numbers, but are miniature graphic icons--in this instance pictures of teeth. When printed on an appropriate laser printer, this produces printed graphics of publishing quality.

A comprehensive study and analysis of second order harmonic ripple in DC microgrid feeding single phase PWM inverter loads

DEFF Research Database (Denmark)

Gautam, Aditya R.; Fulwani, Deepak; Guerrero, Josep M.

2016-01-01

The paper presents a detailed analysis of second order harmonic ripple in a DC microgrid. A boost converter feeding PWM inverter load is considered and equivalent circuit is proposed. The effect of the size of input capacitor, output capacitor and inductor of boost converter, on this ripple has...

Dyslexie font does not benefit reading in children with or without dyslexia

NARCIS (Netherlands)

Kuster, S.M.; Weerdenburg, M.W.C. van; Gompel, M.; Bosman, A.M.T.

2018-01-01

In two experiments, the claim was tested that the font "Dyslexie", specifically designed for people with dyslexia, eases reading performance of children with (and without) dyslexia. Three questions were investigated. (1) Does the Dyslexie font lead to faster and/or more accurate reading? (2) Do

SlaVaComp: Konvertierungstool (= SlaVaComp Fonts Converter

Directory of Open Access Journals (Sweden)

Simon Skilevic

2013-12-01

Full Text Available Der vorliegende Beitrag informiert über ein Tool, das im Rahmen eines Freiburger Projekts zur historischen Korpuslinguistik entwickelt wurde und dazu dient, kirchenslavische Texte, die ohne Einsatz von Unicode digitalisiert wurden, ohne Verlust von Information bzw. Formatierung ins Unicode-Format zu überführen. Das Tool heißt SlaVaComp-Konvertierer. Es eignet sich für die Konvertierung aller idiosynkratischen Fonts und kann somit nicht nur in der Paläoslavistik, sondern in allen historisch arbeitenden Philologien eingesetzt werden. ____________________ This paper presents a fonts converter that was developed as a part of the Freiburg project on historical corpus linguistics. The tool named SlaVaComp-Konvertierer converts Church Slavonic texts digitized with non-Unicode fonts into the Unicode format without any loss of information contained in the original file and without damage to the original formatting. It is suitable for the conversion of all idiosyncratic fonts—not only Church Slavonic—and therefore can be used not only in Palaeoslavistic, but also in all historical and philological studies.

Atmel Microcontroller Based Soft Switched PWM ZVS Full Bridge DC to DC Converter

Directory of Open Access Journals (Sweden)

DEEPAK KUMAR NAYAK

2010-12-01

Full Text Available This paper deals with the simulation and implementation of soft switched PWM ZVS full bridge DC to DC converter. The 48V DC is efficiently reduced to 12V DC using a DC to DC converter. This converter has advantages like reduced switching losses, stresses and EMI. Input DC is converted into high frequency AC and it is stepped down to 12V level. Later it is rectified using a full wave rectifier. Laboratory model of microcontroller based DC to DC converter is fabricated and tested. The experimental results are compared with the simulation results.

Thin grain oriented electrical steel for PWM voltages fed magnetic cores

Directory of Open Access Journals (Sweden)

Thierry Belgrand

2018-04-01

Full Text Available This paper reports on performances of high permeability grain oriented electrical steel when used in association with power electronic switching devices. Loss measurement results obtained from the Epstein test, using sinusoidal or various PWM voltages in medium frequency range, show that for both studied thicknesses (HGO 0.23mm and HGO 0.18mm, comparing performances at a fixed induction level between the various situations may not be the most convenient method. The effect of magnetic domain refinement has been investigated. After having shown the interest of lowering the thickness, an alternative way of looking at losses is proposed that may help to design the magnetic core when it comes to the matter of reducing size in considering frequency and magnetization levels.

Writing and reading training effects on font type and size preferences by students with low vision.

Science.gov (United States)

Atasavun Uysal, Songül; Düger, Tülin

2012-06-01

The effect of writing and reading training on preferred font type and size in low-vision students was evaluated in 35 children. An ophthalmologist confirmed low vision according to ICD-10-CM. Children identified the font type and size they could best read. The writing subtest of the Jebsen-Taylor Hand Function Test, read in 1 min., and legibility as measured by the number of readable written letters were used in evaluating the children. A writing and reading treatment program was conducted, beginning with the child's preferred font type and size, for 3 months, 2 days per week, for 45 min. per day at the child's school. Before treatment, the most preferred font type was Verdana; after treatment, the preferred font type and size changed. Students had gained reading and writing speed after training, but their writing legibility was not significantly better. Training might affect the preferred font type and size of students with low vision. Surprisingly, serif and sans-serif fonts were preferred about equally after treatment.

A Comparison of Phase-Shift Self- Oscillating and Carrier-based PWM Modulation for Embedded Audio Amplifiers

OpenAIRE

Huffenus , Alexandre; Pillonnet , Gaël; Abouchi , Nacer; Goutti , Frédéric

2010-01-01

International audience; This paper compares two modulation schemes for Class-D amplifiers: Phase-Shift Self-Oscillating (PSSO) and Carrier-Based Pulse Width Modulation (PWM). Theoretical analysis (modulation, frequency of oscillation, bandwidth…), design procedure, and IC silicon evaluation will be shown for mono and stereo operation (on the same silicon die) on both structures. The design of both architectures will use as many identical building blocks as possible, to provide a fair, "all el...

As fontes digitais e o ofício de historiador

Directory of Open Access Journals (Sweden)

Micael Alvino Silva

2015-07-01

Full Text Available A depender do objeto de pesquisa, o historiador pode trabalhar a partir de diversas tipologias de fontes que podem variar desde documentos oficiais ou privados, fotografias, áudio, obras literárias ou de arte, cartas, diários, discursos, testamentos, inventários, processos criminais ou administrativos, etc. Para complementar e ampliar ainda mais as possibilidades, o avanço da tecnologia nas últimas décadas tem disponibilizado o acesso a enorme quantidade de acervos e fontes digitais. Pelo menos desde a década de 1970 alguns historiadores já refletem sobre o uso da informática e dos computadores na pesquisa histórica e, particularmente, nossa pesquisa de doutorado nos levou a refletir sobre as fontes digitais em função de nossa pesquisa em três acervos online essenciais ao nosso trabalho. Este artigo pretende analisar os acervos digitais utilizados e refletir com eles sobre o ofício de historiador no século XXI.

PWM Inverter control and the application thereof within electric vehicles

Science.gov (United States)

Geppert, Steven

1982-01-01

An inverter (34) which provides power to an A.C. machine (28) is controlled by a circuit (36) employing PWM control strategy whereby A.C. power is supplied to the machine at a preselectable frequency and preselectable voltage. This is accomplished by the technique of waveform notching in which the shapes of the notches are varied to determine the average energy content of the overall waveform. Through this arrangement, the operational efficiency of the A.C. machine is optimized. The control circuit includes a micro-computer and memory element which receive various parametric inputs and calculate optimized machine control data signals therefrom. The control data is asynchronously loaded into the inverter through an intermediate buffer (38). In its preferred embodiment, the present invention is incorporated within an electric vehicle (10) employing a 144 VDC battery pack (32) and a three-phase induction motor (18).

Design Research on Three-Phase PWM Rectifier Based on Double Closed Loop Control Technology

Directory of Open Access Journals (Sweden)

Guang Ya LIU

2014-02-01

Full Text Available Based on the high frequency of three-phase voltage source PWM rectifier, this paper established a mathematical model of three phase current inner ring and outer ring voltage, and put forward the setting method of three phase double closed loop control. Finally, it was verified through simulation. The experimental results show that Three-phase output of DC voltage is stable with the operation of regulating systems, the current flowing into the grid tends to be sinusoidal and power factor is close to 1, which greatly reduce the interference of harmonics on the grid, thus improve grid operation.

Design of a ZVS PWM inverter for a brushless DC motor in an EMA application

Science.gov (United States)

Bell, J. Brett; Nelms, R. M.; Shepherd, Michael T.

1993-01-01

The Component Development Division of the Propulsion Laboratory at Marshall Space Flight Center (MSFC) is currently investigating the use of electromechanical actuators for use in space transportation applications such as Thrust Vector Control (TVC). These high power servomechanisms will require rugged, reliable, and compact power electronic modules capable of modulating several hundred amperes of current at up to 270 Vdc. This paper will discuss the design and implementation of a zero-voltage-switched PWM (Pulse Width Modulation) inverter which operates from a 270 Vdc source at currents up to 100 A.

Design of a ZVS PWM inverter for a brushless DC motor in an EMA application

Science.gov (United States)

Bell, J. Brett; Nelms, R. M.; Shepherd, Michael T.

The Component Development Division of the Propulsion Laboratory at Marshall Space Flight Center (MSFC) is currently investigating the use of electromechanical actuators for use in space transportation applications such as Thrust Vector Control (TVC). These high power servomechanisms will require rugged, reliable, and compact power electronic modules capable of modulating several hundred amperes of current at up to 270 Vdc. This paper will discuss the design and implementation of a zero-voltage-switched PWM (Pulse Width Modulation) inverter which operates from a 270 Vdc source at currents up to 100 A.

Fontes de crescimento da agricultura do Nordeste : 1970-1999

OpenAIRE

Correia Leitão, Janete

2002-01-01

Neste trabalho analisa-se a evolução da produção agrícola no Nordeste brasileiro e suas fontes de crescimento nas últimas três décadas. Consideramse como fontes de crescimento as mudanças verificadas: a) na área cultivada, b) nos rendimentos por hectare, c) na localização geográfica da produção, ou seja, a mudança na proporção da área cultivada de determinada lavoura cultivada em vários Estados, e d) na composição da produção que resulta de alterações na proporção da área to...

FONTES E TRANSPORTE DE METAIS PESADOS PARA ENSEADA DE JURUJUBA (BAIA DE GUANABARA RJ - BRASIL

Directory of Open Access Journals (Sweden)

José Antônio Baptista Neto

2005-12-01

Full Text Available As fontes de sedimentos e metais pesados para um estuário urbanizado são complexas e difusas. Esta pesquisa tem como objetivo acessar as principais fontes de metais pesados para a enseada de Jurujuba (RJ. Analisaram- se as concentrações dos elementos Cr, Cu, Ni, Pb, Zn e Fe, em amostras de solo, rios e escoamento superficial urbano, bem como sedimentos de marinas. Apesar de se poderem distinguir as fontes naturais das antrópicas de metais pesados para a Enseada de Jurujuba, é evidente que os processos de urbanização são os principais responsáveis pelas maiores concentrações de metais pesados para a enseada, através de rios e escoamento superficial urbano. No entanto, não se podem desprezar a deposição atmosférica e as atividades náuticas como importantes fontes de poluição.Palavras-chave: fontes de sedimentos, poluição de metais pesados, Enseada de Jurujuba, processo de urbanização.

The Effect of a Specialized Dyslexia Font, Opendyslexic, on Reading Rate and Accuracy

Science.gov (United States)

Wery, Jessica J.; Diliberto, Jennifer A.

2017-01-01

A single-subject alternating treatment design was used to investigate the extent to which a specialized dyslexia font, OpenDyslexic, impacted reading rate or accuracy compared to two commonly used fonts when used with elementary students identified as having dyslexia. OpenDyslexic was compared to Arial and Times New Roman in three reading tasks:…

Position control of an electro-pneumatic system based on PWM technique and FLC.

Science.gov (United States)

Najjari, Behrouz; Barakati, S Masoud; Mohammadi, Ali; Futohi, Muhammad J; Bostanian, Muhammad

2014-03-01

In this paper, modeling and PWM based control of an electro-pneumatic system, including the four 2-2 valves and a double acting cylinder are studied. Dynamic nonlinear behavior of the system, containing fast switching solenoid valves and a pneumatic cylinder, as well as electrical, magnetic, mechanical, and fluid subsystems are modeled. A DC-DC power converter is employed to improve solenoid valve performance and suppress system delay. Among different position control methods, a proportional integrator derivative (PID) controller and fuzzy logic controller (FLC) are evaluated. An experimental setup, using an AVR microcontroller is implemented. Simulation and experimental results verify the effectiveness of the proposed control strategies. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

A single-phase PWM controlled AC to DC converter based on control of unity displacement power factor

OpenAIRE

Funabiki, Shigeyuki

1990-01-01

A modified pulse-width modulation (PWM) technique that improves the displacement power factor and the input power factor of a single-phase AC to DC converter is discussed. The modified converter is shown to have a high input power factor and allows the of DC voltage from zero to more than the maximum value of the source voltage. The displacement power factor is unity, and the input power factor is almost unity in the wide range of current command

An eye movement study for identification of suitable font characters for presentation on a computer screen.

Science.gov (United States)

Banerjee, Jayeeta; Majumdar, Dhurjati; Majumdar, Deepti; Pal, Madhu Sudan

2010-06-01

We are experiencing a shifting of media: from the printed paper to the computer screen. This transition is modifying the process of how we read and understand a text. It is very difficult to conclude on suitability of font characters based upon subjective evaluation method only. Present study evaluates the effect of font type on human cognitive workload during perception of individual alphabets on a computer screen. Twenty six young subjects volunteered for this study. Here, subjects have been shown individual characters of different font types and their eye movements have been recorded. A binocular eye movement recorder was used for eye movement recording. The results showed that different eye movement parameters such as pupil diameter, number of fixations, fixation duration were less for font type Verdana. The present study recommends the use of font type Verdana for presentation of individual alphabets on various electronic displays in order to reduce cognitive workload.

The Optimum Font Size and Type for Students Aged 9-12 Reading Arabic Characters on Screen: A Case Study

Science.gov (United States)

Abubaker, A. A.; Lu, J.

2012-05-01

More and more, interest in the way data is displayed on screen has increased, especially with the increase in the number of people using e-text for learning purposes. So, this requires more focus on factors that affect screen legibility. Text display factors, such as font size, line length and font type, have an impact on reading online. Two font types [Arabic Traditional and Simplified Arabic] in four different sizes [10, 14, 16 and 18] are measured using Arabic text. On-line processes were measured using reading-aloud technique. Accuracy of reading was also measured by the average of errors that students made when reading the text, while reading speed was tested by the time it took students to read the text. However, results indicated that Arabic text in font size 10 is not readable to students aged 10 to 12. On the other hand, font sizes sixteen and eighteen are more readable than any smaller-sized font, the averages of error size 18 improve in all font types, while age has a significant impact on reading speed. Simplified Arabic font is reported as readable to students aged 10-12, especially in sizes 14 and 18.

A Dual-Bridge LLC Resonant Converter with Fixed-Frequency PWM Control for Wide Input Applications

DEFF Research Database (Denmark)

Xiaofeng, Sun; Li, Xiaohua; Shen, Yanfeng

2017-01-01

This paper proposes a dual-bridge (DB) LLC resonant converter for wide input applications. The topology is an integration of a half-bridge (HB) LLC circuit and a full-bridge (FB) LLC circuit. The fixed-frequency PWM control is employed and a range of twice the minimum input voltage can be covered....... Compared with the traditional pulse frequency modulation (PFM) controlled HB/FB LLC resonant converter, the voltage gain range is independent of the quality factor and the magnetizing inductor has little influence on the voltage gain, which can simplify the parameter selection process and benefit...

One-Stage and Two-Stage Schemes of High Performance Synchronous PWM with Smooth Pulses-Ratio Changing

DEFF Research Database (Denmark)

Oleschuk, V.; Blaabjerg, Frede

2002-01-01

This paper presents detailed description of one-stage and two-stage schemes of a novel method of synchronous, pulsewidth modulation (PWM) for voltage source inverters for ac drive application. The proposed control functions provide accurate realization of different versions of voltage space vector...... modulation with synchronization of the voltage waveform of the inverter and with smooth pulse-ratio changing. Voltage spectra do not contain even harmonic and sub-harmonics (combined harmonics) during the whole control range including the zone of overmodulation. Examples of determination of the basic control...

The optimal viewing position effect in printed versus cursive words: Evidence of a reading cost for the cursive font.

Science.gov (United States)

Danna, Jérémy; Massendari, Delphine; Furnari, Benjamin; Ducrot, Stéphanie

2018-06-13

Two eye-movement experiments were conducted to examine the effects of font type on the recognition of words presented in central vision, using a variable-viewing-position technique. Two main questions were addressed: (1) Is the optimal viewing position (OVP) for word recognition modulated by font type? (2) Is the cursive font more appropriate than the printed font in word recognition in children who exclusively write using a cursive script? In order to disentangle the role of perceptual difficulty associated with the cursive font and the impact of writing habits, we tested French adults (Experiment 1) and second-grade French children, the latter having exclusively learned to write in cursive (Experiment 2). Results revealed that the printed font is more appropriate than the cursive for recognizing words in both adults and children: adults were slightly less accurate in cursive than in printed stimuli recognition and children were slower to identify cursive stimuli than printed stimuli. Eye-movement measures also revealed that the OVP curves were flattened in cursive font in both adults and children. We concluded that the perceptual difficulty of the cursive font degrades word recognition by impacting the OVP stability. Copyright © 2018 Elsevier B.V. All rights reserved.

Jyske fonte med modstillede løver –

DEFF Research Database (Denmark)

Kaspersen, Søren

2016-01-01

, from the Sumerian to Western Europe in the Romanesque period. Taking these things in consideration, the confronted lions on the baptismal fonts are analyzed in relation to different schemes and contexts: flanking a human head, either with their heads en face or in profile, often with their tongues...

O contexto-fonte e o ensino de línguas

Directory of Open Access Journals (Sweden)

Silvana Serrani-Infante

2002-10-01

Full Text Available No texto, discute-se a noção de contexto-fonte, tendo em vista o papel crucial de fatores interculturais no ensino de línguas não maternas (fator incidente, também, em casos do ensino de língua materna. Na primeira parte, é examinada a complexidade da relação contexto-fonte/contexto-alvo, à luz da concepção bakhtiniana de contexto e da abordagem processual da linguagem e do sujeito. Propõe-se que um foco maior, nas pesquisas e nas práticas pedagógicas, em relação ao contexto-fonte e a sua pluralidade constitutiva, pode se associar às mobilizações subjetivo-identitárias de decentramento cultural que a relação com outras línguas e culturas propicia. Na segunda parte, a partir de pesquisas sobre leitura em português e espanhol, apontam-se conseqüênciaspara as práticas de escrita em língua-alvo. As conclusões dizem respeito ao questionamento do normativismo e da visão instrumentalista na pedagogia de línguas. 

Assessment of an Average Controller for a DC/DC Converter via Either a PWM or a Sigma-Delta-Modulator

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R. Silva-Ortigoza

2014-01-01

Full Text Available Sliding mode control is a discontinuous control technique that is, by its nature, appropriate for controlling variable structure systems, such as the switch regulated systems employed in power electronics. However, when designing control laws based on the average models of these systems a modulator is necessary for their experimental implementation. Among the most widely used modulators in power electronics are the pulse width modulation (PWM and, more recently, the sigma-delta-modulator (Σ-Δ-modulator. Based on the importance of achieving an appropriate implementation of average control laws and the relevance of the trajectory tracking task in DC/DC power converters, for the first time, this research presents the assessment of the experimental results obtained when one of these controllers is implemented through either a PWM or a Σ-Δ-modulator to perform such a task. A comparative assessment based on the integral square error (ISE index shows that, at frequencies with similar efficiency, the Σ-Δ-modulator provides a better tracking performance for the DC/DC Buck converter. In this paper, an average control based on differential flatness was used to perform the experiments. It is worth mentioning that a different trajectory tracking controller could have been selected for this research.

Font Effects of Chinese Characters and Pseudo-Characters on the N400: Evidence for an Orthographic Processing View

Science.gov (United States)

Lv, Caixia; Wang, Quanhong

2012-01-01

Event-related brain potentials (ERPs) were recorded during a Chinese character decision task to examine whether N400 amplitude is modulated by stimulus font. Results revealed large negative-going ERPs in an N400 time window of 300-500 ms to stimuli presented in degraded Xing Kai Ti (XKT) font compared with more intact Song Ti (ST) font regardless…

[Explicit memory for type font of words in source monitoring and recognition tasks].

Science.gov (United States)

Hatanaka, Yoshiko; Fujita, Tetsuya

2004-02-01

We investigated whether people can consciously remember type fonts of words by methods of examining explicit memory; source-monitoring and old/new-recognition. We set matched, non-matched, and non-studied conditions between the study and the test words using two kinds of type fonts; Gothic and MARU. After studying words in one way of encoding, semantic or physical, subjects in a source-monitoring task made a three way discrimination between new words, Gothic words, and MARU words (Exp. 1). Subjects in an old/new-recognition task indicated whether test words were previously presented or not (Exp. 2). We compared the source judgments with old/new recognition data. As a result, these data showed conscious recollection for type font of words on the source monitoring task and dissociation between source monitoring and old/new recognition performance.

Advanced Control Strategy of Back-to-Back PWM Converters in PMSG Wind Power System

Directory of Open Access Journals (Sweden)

Tan Luong Van

2015-01-01

Full Text Available This paper proposes a control scheme of back-to-back PWM converters for the permanent magnet synchronous generator (PMSG wind turbine system. The DC-link voltage can be controlled at the machine-side converter (MSC, while the grid-side converter (GSC controls the grid active power for a maximum power point tracking (MPPT. At the grid fault condition, the DC-link voltage controller is designed using a feedback linearization (FL theory. For the MPPT, a proportional control loop is added to the torque control to reduce the influence of the inertia moment in the wind turbines, which can improve its dynamic performance. The validity of this control algorithm has been verified by the simulation of the 2-MW PMSG wind turbine system.

Crystal Structure of Serine Racemase that Produces Neurotransmitter font-variant:small-caps">d-Serine for Stimulation of the NMDA Receptor

Science.gov (United States)

Goto, Masaru

font-variant:small-caps">d-Serine is an endogenous coagonist for the N-methyl-font-variant:small-caps">d-aspartate receptor and is involved in excitatory neurotransmission in the brain. Mammalian pyridoxal 5’-phosphate-dependent serine racemase, which is localized in the mammalian brain, catalyzes the racemization of font-variant:small-caps">l-serine to yield font-variant:small-caps">d-serine and vice versa. We have determined the structures of three forms of the mammalian enzyme homolog from Schizosaccharomyces pombe. Lys57 and Ser82 located on the protein and solvent sides, respectively, with respect to the cofactor plane, are acid-base catalysts that shuttle protons to the substrate. The modified enzyme, which has a unique lysino-font-variant:small-caps">d-alanyl residue at the active site, also binds the substrate serine in the active site, suggesting that the lysino-font-variant:small-caps">d-alanyl residue acts as a catalytic base in the same manner as Lys57 of the wild type enzyme.

O FILME COMO FONTE DE INFORMAÇÃO APLICADO AO ENSINO DA BIBLIOTECONOMIA

Directory of Open Access Journals (Sweden)

Carla Façanha de Brito

2017-02-01

Full Text Available Trata da experiência com a utilização dos filmes: ‘Central do Brasil’ e ‘Uma Cidade sem Passado’ como ferramenta pedagógica na disciplina Fontes Gerais da Informação do Curso de Biblioteconomia da Universidade Federal do Cariri. Tem como objetivo identificar o filme como metodologia criativa para apoio ao ensino da disciplina de Fontes Gerais da Informação proporcionando aprendizagem e aprofundamento das temáticas. O exercício da aprendizagem passa por uma dinâmica que concerne quatro etapas que vão desde o primeiro contato com a disciplina através do estudo do plano de aula à leitura, análise e discussão do filme. O filme por meio de imagens em movimento, desperta interesse e aponta caminhos para uma discussão que revela a importância das fontes informacionais para otimizar o cotidiano da sociedade e a prática da docência.

Protegendo Fontes: De Leis de Proteção a Wikileaks

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Mélanie Dupéré

2015-09-01

Full Text Available Este trabalho se concentra sobre a evolução recente o direito e a capacidade dos jornalistas de proteger o anonimato de suas fontes no Reino Unido, particularmente à luz das revelações de Snowden em junho de 2013, bem como a importância da cooperação entre a organização de mídia online WikiLeaks e as organiza ções noticiosas. O artigo explora duas dificuldades principais enfrentadas por jornalistas: a noção de um privilégio profissional qualificado e a extensão desconhecida de solicitações de acobertamento de divulgação por autoridades públicas envolvendo comunicações dados e metadados. Ao fazê-lo, o estudo comenta o caso Wikileaks, que protege suas fontes anônimas por meio da alta segurança de dados e criptografia. Os resultados tendem a mostrar que a prática de cobertura de vigilância digital de massa de comunicações individuais, incluindo jornalistas, está a minar a proteção da fonte e a ascensão do Wikileaks como um modelo alternativo está desafiando o papel tradicional de jornalistas como mediadores e gatekeepers na era digital.

Descoberta de um aglomerado estelar massivo associado a fonte IRAS 16177-5018

Science.gov (United States)

Roman Lopes, A.; Abraham, Z.; Lépine, J. R. D.

2003-08-01

Neste trabalho apresentamos a descoberta de um aglomerado de estrelas jovens e massivas embebido em uma região HII extensa associado com a fonte IRAS 16177-5018, que se apresenta invisível na faixa óptica do espectro eletromagnético, onde a extinção é da ordem de AV = 26 magnitudes. As observações foram feitas com a camera infravermelha (CamIV) do Laboratório Nacional de Astrofísica, Brasil, equipada com um detector Hawaii de HgCdTe de 1024´1024 pixel acoplada ao telescópio de 60 cm Boller & Chivens do IAG. A fotometria obtida a partir das imagens nas bandas J, H e K (filtro estreito) mostrou a presença de fontes com excesso de emissão no infravermelho em 2.2 mm, concentradas em uma área de aproximadamente um minuto de arco quadrado em torno da nebulosa na qual esta embebido o objeto identificado como a fonte IRAS. A fonte IRAS apresenta um índice espectral (entre 2.2 21.3 mm) a = d log(l Fl) / d log l = 4.78, característico de um objeto extremamente jovem com luminosidade bolométrica (obtida da integral da densidade de fluxo entre o infravermelho próximo (1.25mm) e o infravermelho distante (100mm)) de 2.8´105L¤, o qual corresponde a uma estrela da sequência principal de idade zero de cerca de 42 M¤. A partir do diagrama cor-magnitude foi possível classificar a maioria dos membros do aglomerado como estrelas massivas mais luminosas que tipo espectral B5.

Fontes e modos de aplicação de boro na cultura do eucalipto

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Thiago de Souza Celestrino

2015-12-01

Full Text Available Os solos de Cerrado apresentam baixo teor de boro (B no solo, sendo comum a suplementação deste elemento através da adubação via solo e/ou foliar. Portanto, é importante definir qual o melhor modo de aplicação e fonte de B para o bom desenvolvimento do eucalipto. Assim, o objetivo deste trabalho foi comparar o efeito de fontes de B com alta e baixa solubilidade na cultura do eucalipto, bem como a aplicação foliar do micronutriente. O experimento foi conduzido em uma área com latitude 20o 34’ S e longitude 51o 50’ O e altitude de 305 m, no período de 01/2012 a 02/2014. O delineamento experimental foi o de blocos casualizados com seis tratamentos e cinco repetições, dispostos em um esquema fatorial de 3 x 2, sendo: 0 kg ha-1 de B, 1 kg ha-1 de B utilizando como fonte o ácido bórico (alta solubilidade, 17% B ou1 kg ha-1 de B utilizando como fonte o borogran (baixa solubilidade, 10% B, aplicados no sulco de plantio, com ou sem aplicações de ácido bórico via foliar na dose de 0,5% de ácido bórico na calda com volume de 250 L ha-1. Com a omissão de B via foliar houve incremento em altura de plantas nos tratamentos que receberam a aplicação do micronutriente no plantio, diferindo significativamente da testemunha. Porém, ambas as fontes, independente da solubilidade, apresentaram resultados semelhantes. As duas aplicações de B via foliar foram suficientes para que houvesse incremento em altura de plantas, quando comparadas aos tratamentos que não receberam aplicação de B no plantio, aos 21 meses. Aos 24 meses após o plantio foi constatado aumento no teor foliar de B nos tratamentos que receberam aplicação foliar. No entanto, esta não incrementou o crescimento, DAP e volume de madeira do clone de eucalipto. A aplicação de B no plantio, independente da fonte utilizada, assim como aplicação foliar do elemento, foram suficientes para reduzir os sintomas de deficiência de B. Com relação às fontes utilizadas no

Letter processing and font information during reading: beyond distinctiveness, where vision meets design.

Science.gov (United States)

Sanocki, Thomas; Dyson, Mary C

2012-01-01

Letter identification is a critical front end of the reading process. In general, conceptualizations of the identification process have emphasized arbitrary sets of distinctive features. However, a richer view of letter processing incorporates principles from the field of type design, including an emphasis on uniformities across letters within a font. The importance of uniformities is supported by a small body of research indicating that consistency of font increases letter identification efficiency. We review design concepts and the relevant literature, with the goal of stimulating further thinking about letter processing during reading.

A Method of Maximum Power Control in Single-phase Utility Interactive Photovoltaic Generation System by using PWM Current Source Inverter

Science.gov (United States)

Neba, Yasuhiko

This paper deals with a maximum power point tracking (MPPT) control of the photovoltaic generation with the single-phase utility interactive inverter. The photovoltaic arrays are connected by employing the PWM current source inverter to the utility. The use of the pulsating dc current and voltage allows the maximum power point to be searched. The inverter can regulate the array voltage and keep the arrays to the maximum power. This paper gives the control method and the experimental results.

Comparative analysis between different font types and letter styles using a nonlinear invariant digital correlation

Science.gov (United States)

Coronel-Beltrán, Ángel; Álvarez-Borrego, Josué

2010-01-01

We present, in this paper, a comparative analysis of the letters in Times New Roman (TNR), Courier New (CN) and Arial (Ar) font types in plain and italic style and the effects of five foreground/background color combinations using an invariant digital correlation system with a nonlinear filter with k = 0.3. The evaluation of the output plane with this filter is given by the peak-to-correlation energy (PCE) metric. The results show that the letters in TNR font have a better mean PCE value when compared with the CN and Ar fonts. This result is in agreement with some studies on text legibility and for readability where the reaction time (RT) of some participant individuals reading a text is measured. We conclude that the PCE metric is proportional to 1/RT.

Font size and viewing distance of handheld smart phones.

Science.gov (United States)

Bababekova, Yuliya; Rosenfield, Mark; Hue, Jennifer E; Huang, Rae R

2011-07-01

The use of handheld smart phones for written communication is becoming ubiquitous in modern society. The relatively small screens found in these devices may necessitate close working distances and small text sizes, which can increase the demands placed on accommodation and vergence. Font size and viewing distance were measured while subjects used handheld electronic devices in two separate trials. In the first study (n=129), subjects were asked to show a typical text message on their own personal phone and to hold the device "as if they were about to read a text message." A second trial was conducted in a similar manner except subjects (n=100) were asked to view a specific web page from the internet. For text messages and internet viewing, the mean font size was 1.1 M (range, 0.7 to 2.1 M) and 0.8 M (range, 0.3 to 1.4 M), respectively. The mean working distance for text messages and internet viewing was 36.2 cm (range, 17.5 to 58.0 cm) and 32.2 cm (range, 19 to 60 cm), respectively. The mean font size for both conditions was comparable with newspaper print, although some subjects viewed text that was considerably smaller. However, the mean working distances were closer than the typical near working distance of 40 cm for adults when viewing hardcopy text. These close distances place increased demands on both accommodation and vergence, which could exacerbate symptoms. Practitioners need to consider the closer distances adopted while viewing material on smart phones when examining patients and prescribing refractive corrections for use at near, as well as when treating patients presenting with asthenopia associated with nearwork. Copyright © 2011 American Academy of Optometry

Internal-Model-Principle-Based Specific Harmonics Repetitive Controller for Grid-Connected PWM Inverters

Directory of Open Access Journals (Sweden)

Wenzhou Lu

2016-01-01

Full Text Available This paper analyzes the general properties of IMP-based controller and presents an internal-model-principle-based (IMP-based specific harmonics repetitive control (SHRC scheme. The proposed SHRC is effective for specific nk±m order harmonics, with n>m≥0 and k=0,1,2,…. Using the properties of exponential function, SHRC can also be rewritten into the format of multiple resonant controllers in parallel, where the control gain of SHRC is n/2 multiple of that of conventional RC (CRC. Therefore, including SHRC in a stable closed-loop feedback control system, asymptotic disturbance eliminating, or reference tracking for any periodic signal only including these specific harmonic components at n/2 times faster error convergence rate compared with CRC can be achieved. Application examples of SHRC controlled three-phase/single-phase grid-connected PWM inverters demonstrate the effectiveness and advantages of the proposed SHRC scheme.

Selection of the optimum font type and size interface for on screen continuous reading by young adults: an ergonomic approach.

Science.gov (United States)

Banerjee, Jayeeta; Bhattacharyya, Moushum

2011-12-01

There is a rapid shifting of media: from printed paper to computer screens. This transition is modifying the process of how we read and understand text. The efficiency of reading is dependent on how ergonomically the visual information is presented. Font types and size characteristics have been shown to affect reading. A detailed investigation of the effect of the font type and size on reading on computer screens has been carried out by using subjective, objective and physiological evaluation methods on young adults. A group of young participants volunteered for this study. Two types of fonts were used: Serif fonts (Times New Roman, Georgia, Courier New) and Sans serif fonts (Verdana, Arial, Tahoma). All fonts were presented in 10, 12 and 14 point sizes. This study used a 6 X 3 (font type X size) design matrix. Participants read 18 passages of approximately the same length and reading level on a computer monitor. Reading time, ranking and overall mental workload were measured. Eye movements were recorded by a binocular eye movement recorder. Reading time was minimum for Courier New l4 point. The participants' ranking was highest and mental workload was least for Verdana 14 point. The pupil diameter, fixation duration and gaze duration were least for Courier New 14 point. The present study recommends using 14 point sized fonts for reading on computer screen. Courier New is recommended for fast reading while for on screen presentation Verdana is recommended. The outcome of this study will help as a guideline to all the PC users, software developers, web page designers and computer industry as a whole.

On the Fonte structure between a pair of Banach spaces

International Nuclear Information System (INIS)

Sharma, C.S.

1990-01-01

The main purpose of the present note is to establish the essential equivalence of the adjoint of a semilinear map defined through the Fonte structure between a pair of Banach spaces and the adjoint of the same map defined by Pian and the present author

A New Pixels Flipping Method for Huge Watermarking Capacity of the Invoice Font Image

Directory of Open Access Journals (Sweden)

Li Li

2014-01-01

Full Text Available Invoice printing just has two-color printing, so invoice font image can be seen as binary image. To embed watermarks into invoice image, the pixels need to be flipped. The more huge the watermark is, the more the pixels need to be flipped. We proposed a new pixels flipping method in invoice image for huge watermarking capacity. The pixels flipping method includes one novel interpolation method for binary image, one flippable pixels evaluation mechanism, and one denoising method based on gravity center and chaos degree. The proposed interpolation method ensures that the invoice image keeps features well after scaling. The flippable pixels evaluation mechanism ensures that the pixels keep better connectivity and smoothness and the pattern has highest structural similarity after flipping. The proposed denoising method makes invoice font image smoother and fiter for human vision. Experiments show that the proposed flipping method not only keeps the invoice font structure well but also improves watermarking capacity.

A new pixels flipping method for huge watermarking capacity of the invoice font image.

Science.gov (United States)

Li, Li; Hou, Qingzheng; Lu, Jianfeng; Xu, Qishuai; Dai, Junping; Mao, Xiaoyang; Chang, Chin-Chen

2014-01-01

Invoice printing just has two-color printing, so invoice font image can be seen as binary image. To embed watermarks into invoice image, the pixels need to be flipped. The more huge the watermark is, the more the pixels need to be flipped. We proposed a new pixels flipping method in invoice image for huge watermarking capacity. The pixels flipping method includes one novel interpolation method for binary image, one flippable pixels evaluation mechanism, and one denoising method based on gravity center and chaos degree. The proposed interpolation method ensures that the invoice image keeps features well after scaling. The flippable pixels evaluation mechanism ensures that the pixels keep better connectivity and smoothness and the pattern has highest structural similarity after flipping. The proposed denoising method makes invoice font image smoother and fiter for human vision. Experiments show that the proposed flipping method not only keeps the invoice font structure well but also improves watermarking capacity.

Fontes binárias supermoles de raios X

Science.gov (United States)

Pires, A. M.; Janot Pacheco, E.

2003-08-01

Estuda-se as características físicas das fontes supermoles (de raios X (SSS), utilizando dados ópticos e em altas energias, no âmbito de um trabalho de IC. Trata-se de binárias que apresentam espectro X muito mole, baixas temperaturas e altas luminosidades bolométricas. Esse sistemas são compostos por uma anã branca realizando fusão em sua superfície, a partir de matéria perdida pela estrela companheira. Os resíduos de fusão se acumulam na superfície da anã branca, e essa pode ultrapassar o limite de Chadrasekhar, produzir um colapso gravitacional, sendo esse um dos cenários propostos para as explosões de SN Ia. Apresentamos nesta comunicação o estado da arte das características físicas das fontes SSS, situando-as no âmbito das VCs. Procuramos também situar esses objetos em relação às variáveis galácticas V Sge, na medida em que os dois grupos apresentam certas caracerísticas bastante semelhantes.A metodologia adotada é aquela pedagógico-cognitiva clássica de um trabalho de IC na área de ciências exatas.

A familiar font drives early emotional effects in word recognition.

Science.gov (United States)

Kuchinke, Lars; Krause, Beatrix; Fritsch, Nathalie; Briesemeister, Benny B

2014-10-01

The emotional connotation of a word is known to shift the process of word recognition. Using the electroencephalographic event-related potentials (ERPs) approach it has been documented that early attentional processing of high-arousing negative words is shifted at a stage of processing where a presented word cannot have been fully identified. Contextual learning has been discussed to contribute to these effects. The present study shows that a manipulation of the familiarity with a word's shape interferes with these earliest emotional ERP effects. Presenting high-arousing negative and neutral words in a familiar or an unfamiliar font results in very early emotion differences only in case of familiar shapes, whereas later processing stages reveal similar emotional effects in both font conditions. Because these early emotion-related differences predict later behavioral differences, it is suggested that contextual learning of emotional valence comprises more visual features than previously expected to guide early visual-sensory processing. Copyright © 2014 Elsevier Inc. All rights reserved.

Seeking Visual Clarity an Examination of Font Legibility and Visual Presentation for Elementary-Level Special Education Students

Science.gov (United States)

Haugen, Theresa Tetrick

2010-01-01

This study examined font and layout alternatives for mild special education children in third through sixth grade. Of this group, twelve were boys and two were girls, seven were suburban students and seven were urban students. During the first phase, the students were observed reading four different fonts, then the participant named the easiest…

O estudo das fontes estrangeiras na obra de Machado de Assis e o caso italiano

Directory of Open Access Journals (Sweden)

Eugênio Vinci de Moraes

2008-04-01

Full Text Available Os estudos das fontes italianas na obra de Machado de Assis ainda são uma esquecida árvore no meio da floresta dos estudos machadianos. Três aspectos explicam talvez a posição marginal dessas pesquisas: primeiro, o número menor de refer~encias italianas perante as inglesas e francesas, por exemplo; segundo, a ausência de estudos de maior fôlego; por último, por essa fonte não tocar nas questões centrais da obra de Machado. Neste artigo pretende-se mostrar de que forma trabalhar com as fontes em Machado, com base em três modelos de análise, e também de que forma esses estudos podem tocar, sim, em pontos fundamentais da obra de Machado, desde que não se desdenhe a já alentada e qualificada fortuna crítica do escritor fluminense.

Phase shift PWM with double two-switch bridge for high power capacitor charging

International Nuclear Information System (INIS)

Karandikar, U.S.; Singh, Yashpal; Thakurta, A.C.

2013-01-01

Pulse power supply systems working at higher voltage and high repetition rate demands for higher power from capacitor chargers. Capacitor charging requirement become more challenging in such cases. In pulse power circuits, energy storage capacitor should be charged to its desired voltage before the next switching occurs. It is discharged within a small time, delivering large pulse power. A capacitor charger has to work with wide load variation repeatedly. Many schemes are used for this purpose. The proposed scheme aims at reducing stresses on switches by reducing peak current and their evils. A high voltage power supply is designed for capacitor charging. The proposed scheme is based on a Phase-Shifted PWM without using any extra component to achieve soft switching. Indirect constant average current capacitor charging is achieved with a simple control scheme. A double two-switch bridge is proposed to enhance reliability. Power supply has been developed to charge a capacitor of 50 μF to 2.5 kV at 25 Hz. (author)

Performance optimization of a photovoltaic chain conversion by the PWM control

Science.gov (United States)

Rezoug, M. R.; Chenni, R.

2017-02-01

The interest of the research technique of maximum power point tracking, exposed by this article, lays in the fact of work instantly on the real characteristic of the photovoltaic module. This work is based on instantaneous measurements of its terminals' current & voltage as well as the exploitation of the characteristic "Power - Duty Cycle" to define rapidly the Duty cycle in which power reaches its maximum value. To ensure instantaneous tracking of the point of maximum power, we use "DC/DC Converter" based on "Pulse Wave Modulation's (PWM) Command" controlled by an algorithm implanted in a microcontroller's memory. This algorithm responds to the quick changes in climate (sunlight and temperature). To identify the control parameters "VPV & IPV" at any change in operating conditions, sensors are projected. this algorithm applied to the Duty cycle of the static converter enables the control of power supplied by the photovoltaic generator thanks to oscillatory movement around the MPP. Our article highlights the importance of this technique which lays in its simplicity and performance in changing climatic conditions. This efficiency is confirmed by experimental tests and this technique will improve its predecessors.

FONTES ALTERNATIVAS E RENOVÁVEIS DE ENERGIA NO BRASIL: MÉTODOS E BENEFÍCIOS AMBIENTAIS

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Raphael Santos do Nascimento

2017-01-01

Full Text Available Resumo: Atualmente, os recursos renováveis tem sido o foco de inúmeras pesquisas, devido à preocupação com o meio ambiente. Nesse sentido, várias são as razões para a implementação de fontes renováveis de energia. Assim, o objetivo desse estudo foi identificar os diferentes tipos de energias renováveis existentes no Brasil, bem como, a aplicabilidade e o impacto ambiental gerado por essas fontes. O trabalho foi desenvolvido sobre os preceitos do estudo exploratório por meio de uma pesquisa bibliográfica. Foram identificados cinco tipos de energias alternativas renováveis no Brasil, Biomassa, Eólica, Geotérmica, Hidráulica, Marítima e Solar. A energia Solar foi considerada a mais viável em função de sua aplicabilidade, mesmo em locais isolados, do potencial encontrado em todo território, e, a redução dos impactos ambientais. Foram consideradas expressivas as diferenças de impacto ambiental entre as fontes estudadas e as fontes não-renováveis. Ainda, identificou-se que mesmo com diversas alternativas energéticas e um imenso potencial de recursos renováveis, a utilização desses recursos no Brasil deve ser considerada insuficiente para geração de energia.

El món del consum: una aproximació a les fonts d'informació

OpenAIRE

Llorens, Maria Josep; Fullà i Bohigas, Núria

1997-01-01

Aquest article pretén introduir el lector en la temàtica del consum i en les seves fonts d'informació. S'ha estructurat en base a les diferents tipologies d'informació, citant, en cada cas, una mostra de les fonts documentals més representatives. Finalment, s'hi exposa la situació dels centres de recursos documentals sobre aquest tema a Catalunya i es facilita una llista de biblioteques de temàtica complementària.

The effects of luminance contrast, colour combinations, font, and search time on brand icon legibility.

Science.gov (United States)

Ko, Ya-Hsien

2017-11-01

This study explored and identified the effects of luminance contrast, colour combinations, font, and search time on brand icon legibility. A total of 108 participants took part in the experiment. As designed, legibility was measured as a function of the following independent variables: four levels of luminance contrast, sixteen target/background colour combinations, two fonts, and three search times. The results showed that a luminance contrast of 18:1 provided readers with the best legibility. Yellow on black, yellow on blue, and white on blue were the three most legible colour combinations. One of this study's unique findings was that colour combinations may play an even more important role than luminance contrast in the overall legibility of brand icon design. The 12-s search time corresponded with the highest legibility. Arial font was more legible than Times New Roman. These results provide some guidance for brand icon and product advertisement design. Copyright © 2017 Elsevier Ltd. All rights reserved.

Design and implementation of high performance direct power control of three-phase PWM rectifier, via fuzzy and PI controller for output voltage regulation

International Nuclear Information System (INIS)

Bouafia, Abdelouahab; Krim, Fateh; Gaubert, Jean-Paul

2009-01-01

This paper proposes direct power control (DPC) for three-phase PWM rectifiers using a new switching table, without line voltage sensors. The instantaneous active and reactive powers, directly controlled by selecting the optimum state of the converter, are used as the PWM control variables instead of the phase line currents being used. The main goal of the control system is to maintain the dc-bus voltage at the required level, while input currents drawn from the power supply should be sinusoidal and in phase with respective phase voltages to satisfy the unity power factor (UPF) operation. Conventional PI and a designed fuzzy logic-based controller, in the dc-bus voltage control loop, have been used to provide active power command. A dSPACE based experimental system was developed to verify the validity of the proposed DPC. The steady-state, and dynamic results illustrating the operation and performance of the proposed control scheme are presented. As a result, it was confirmed that the novel DPC is much better than the classical one. Line currents very close to sinusoidal waveforms (THD < 2%) and good regulation of dc-bus voltage are achieved using PI or fuzzy controller. Moreover, fuzzy logic controller gives excellent performance in transient state, a good rejection of impact load disturbance, and a good robustness

Perfil lipídico tecidual de ratos alimentados com diferentes fontes lipídicas

OpenAIRE

Almeida,Martha Elisa Ferreira de; Queiroz,José Humberto de; Queiroz,Maria Eliana Lopes Ribeiro de; Costa,Neuza Maria Brunoro; Matta,Sérgio Luis Pinto

2009-01-01

OBJETIVO:Determinar se fontes lipídicas com diferentes razões de ácidos graxos insaturados e saturados (PUFA+MUFA)/SFA na dieta altera o perfil lipídico tecidual, a concentração de lipídios (mg/g) dos tecidos hepáticos e mesentérico e a digestibilidade lipídica. MÉTODOS: Foi realizada cromatografia gasosa para determinar o perfil de ácidos graxos nos tecidos hepático e adiposo de ratos alimentados com diferentes fontes lipídicas. O coeficiente de digestibilidade foi determinado a partir da re...

JUS COGENS E A VALIDADE NORMATIVA: RUPTURA AO PARADIGMA DAS TRADICIONAIS FONTES NA TEORIA DO DIREITO INTERNACIONAL

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Leonam Baesso da Silva Liziero

2015-07-01

Full Text Available O presente artigo problematizará o papel do jus cogens como uma fonte do direito internacional público, de reconhecimento posterior ao estabelecido pelo Estatuto da Corte Internacional de Justiça. Neste aspecto, é necessário se discutir o que representa o denominado jus cogens dentro da atual configuração do direito internacional público. Inicialmente será debatido a respeito de uma nova visão das fontes do direito internacional público que, a partir de 1945 com o advento do sistema Nações Unidas e posteriormente com a implementação das normas internacionais humanitárias e de proteção aos direitos humanos, é necessária para a compreensão da sociedade internacional contemporânea. O que se defende é a obsolescência do direito internacional composto apenas pelas fontes reconhecidas pelo Estatuto da Corte Internacional de Justiça. Posteriormente será discutido o lugar que ele ocupa no direito internacional, se é fonte ou apenas um critério de resolução de antinomias.

A história cultural e as fontes de pesquisa

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Alboni Marisa Dudeque Pianovski Vieira

2015-07-01

Full Text Available Na primeira metade do século XX, a história “abriu-se” para as demais ciências, com uma proposta de diálogo interdisciplinar. O campo historiográfico, então, sofreu mudança significativa, obrigando os historiadores a reconsiderar o conceito de fontes, para além daquelas predominantemente documentais, na pesquisa em história. Sobre essas fontes de pesquisa incide a reflexão, considerando-se a contribuição que os avanços tecnológicos trazem à coleta de dados, em particular, na história oral. Do ponto de vista metodológico, trata-se de estudo de caso, com caráter bibliográfico, que traça uma retrospectiva da história cultural, enfatizando as possibilidades de uso da história oral. Como aporte teórico, foram consultados estudos de Ribeiro (2003, Pesavento (2005 e Alberti (2005. Os resultados apontam para possibilidades de utilização da história oral na pesquisa em história cultural.

Objetivos de organizações culturais sem fins lucrativos e suas fontes financiadoras

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Samara Regina Bernardino Hoffmann

Full Text Available A fim de compreender as mudanças no contexto das organizações culturais, apresenta-se uma reflexão sobre as transformações nos objetivos de dois grupos teatrais sem fins lucrativos de Florianópolis-SC e sobre a influência que os critérios requeridos pelas fontes financiadoras podem ter exercido neste processo. Quatro importantes categorias de análise guiaram a pesquisa: grupo teatral, objetivos, fontes de financiamento e critérios de avaliação de desempenho, orientando as entrevistas semi-estruturadas realizadas com os responsáveis pelas respectivas organizações e a observação constante das pesquisadoras em encontros, reuniões, ensaios e apresentações de espetáculos envolvendo as organizações pesquisadas. A pesquisa, predominantemente qualitativa e longitudinal gerou reflexões ante os dados coletados, com destaque para a história do Erro Grupo, que apresentou um forte distanciamento de seus propósitos iniciais ao longo de sua trajetória, por direcionar suas ações à captação de recursos junto às fontes financiadoras em detrimento de sua dedicação às atividades teatrais.

Prática social e armadilhas das fontes: as fontes historiográficas e normativas sobre o casamento por rapto na Alta Idade Média

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Sylvie Joye

2010-06-01

Full Text Available O casamento por rapto é uma prática reprovada e juridicamente condenada, mas, ao mesmo tempo, até certo ponto, tolerada socialmente, na alta Idade Média, no Ocidente. Assim, o estatuto atribuído às fontes normativas (em particular as leis bárbaras e a maneira pela qual alguns artigos de lei foram isolados de seu contexto documentário explicam, em grande parte, a razão de historiadores terem, por muito tempo, visto, no rapto, uma forma de casamento completo e uma sobrevivência de instituições "germânicas" antigas. Quanto às fontes narrativas, é imperativo não esquecer o contexto de sua redação, mesmo se, às vezes, ele parece relativamente neutro. De outra forma, corremos o risco de dar muito peso a alguns exemplos marginais ou pouco representativos. Recolocar no contexto dos documentos e da ideologia os retumbantes exemplos do período carolíngio permite, assim, relativizar a idéia de um crescimento importante do número de raptos nesta época.

Estrutura de capital: o papel das fontes de financiamento nas quais companhias abertas brasileiras se baseiam

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Wilson Tarantin Junior

2015-01-01

Full Text Available ResumoEste estudo avaliou a estrutura de capital de companhias abertas brasileiras, no período de 2005 a 2012, verificando o papel das fontes de financiamento nas quais tais companhias se baseiam. Para tanto, foi avaliada a proporção das dívidas em 3 fontes distintas: as instituições financeiras, o mercado de capitais e as fontes com taxas de juros subsidiadas, estas últimas representando um fator institucional da economia brasileira. Foi utilizada uma amostra de 95 empresas, dentre as 150 maiores empresas com ações negociadas na Bolsa de Valores, Mercadorias e Futuros de São Paulo (BM&FBOVESPA. Por meio de modelos com dados em painel, os resultados mostram que as fontes de financiamento impactam a formação da estrutura de capital das empresas, exercendo influência tanto na alavancagem quanto na maturidade das dívidas. Em relação à alavancagem, empresas que têm maior proporção de seus recursos captados no mercado de capitais são mais alavancadas. O mesmo não acontece com as empresas que têm maior proporção de recursos subsidiados. Em relação à maturidade das dívidas, recursos de diferentes maturidades são captados em diferentes fontes: os recursos de menores maturidades são captados em instituições financeiras e os recursos de maiores maturidades são captados no mercado de capitais e nas fontes com taxas de juros subsidiadas - leia-se Banco Nacional de Desenvolvimento Econômico e Social (BNDES. Comparando-se os recursos do mercado de capitais com os recursos subsidiados, verifica-se que os primeiros têm maior maturidade. Tal resultado pode ser justificado em virtude do crescimento do mercado de capitais brasileiro nos últimos anos, a partir de 2009, de modo que as companhias estão se baseando no mercado de capitais para seus financiamentos de maior maturidade e nos recursos subsidiados, do BNDES, para seus financiamentos de maturidades intermediárias.

Vibration and acoustic noise emitted by dry-type air-core reactors under PWM voltage excitation

Science.gov (United States)

Li, Jingsong; Wang, Shanming; Hong, Jianfeng; Yang, Zhanlu; Jiang, Shengqian; Xia, Shichong

2018-05-01

According to coupling way between the magnetic field and the structural order, structure mode is discussed by engaging finite element (FE) method and both natural frequency and modal shape for a dry-type air-core reactor (DAR) are obtained in this paper. On the basis of harmonic response analysis, electromagnetic force under PWM (Pulse Width Modulation) voltage excitation is mapped with the structure mesh, the vibration spectrum is gained and the consequences represents that the whole structure vibration predominates in the radial direction, with less axial vibration. Referring to the test standard of reactor noise, the rules of emitted noise of the DAR are measured and analyzed at chosen switching frequency matches the sample resonant frequency and the methods of active vibration and noise reduction are put forward. Finally, the low acoustic noise emission of a prototype DAR is verified by measurement.

High benefits approach for electrical energy conversion in electric vehicles from DC to PWM-AC without any generated harmonic

International Nuclear Information System (INIS)

Fathabadi, Hassan

2014-01-01

Highlights: • Novel hybrid power source including AC feature for using in electric/hybrid vehicles. • Minimizing the energy loss in electric/hybrid vehicles by using the proposed system. • Suitable AC wave form for braking/accelerating purposes in electric/hybrid vehicles. • A novelty is that the harmonic generated by the added AC feature is really zero. • Another novelty is the capability of choosing arbitrary frequency for AC feature. - Abstract: This paper presents a novel hybrid power source, including a Li-ion battery together with an interface, which generates simultaneously electrical energy with the forms of both DC and AC for electric vehicles. A novel and high benefits approach is applied to convert the electrical energy of the Li-ion battery from DC form to single-phase symmetric pulse-width modulation (PWM)-AC form. Harmonic generation is one of the important problems when electrical energy is converted from DC to AC but there are not any generated harmonic during the DC/AC conversion using the proposed technique. The proposed system will be widely used in electric/hybrid vehicles because it has many benefits. Minimizing the energy loss (saving energy), no generated harmonic (it is really zero), the capability of arbitrary/necessary frequency selection for output AC voltage and the ability of long distance energy transmission are some novelties and advantages of the proposed system. The proposed hybrid power source including DC/AC PWM inverter is simulated in Proteus 6 software environment and a laboratory-based prototype of the hybrid power source is constructed to validate the theoretical and simulation results. Simulation and experimental results are presented to prove the superiority of the proposed hybrid power supply

A CMOS/SOI Single-input PWM Discriminator for Low-voltage Body-implanted Applications

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Jader A. De Lima

2002-01-01

Full Text Available A CMOS/SOI circuit to decode Pulse-Width Modulation (PWM signals is presented as part of a body-implanted neurostimulator for visual prosthesis. Since encoded data is the sole input to the circuit, the decoding technique is based on a novel double-integration concept and does not require low-pass filtering. Non-overlapping control phases are internally derived from the incoming pulses and a fast-settling comparator ensures good discrimination accuracy in the megahertz range. The circuit was integrated on a 2 μm single-metal thin-film CMOS/SOI fabrication process and has an effective area of 2 mm2. Measured resolution of encoding parameter α is better than 10% at 6 MHz and VDD = 3.3 V. Idle-mode consumption is 340 μW. Pulses of frequencies up to15 MHz and α =10% can be discriminated for 2.3 V ≤ VDD ≤ 3.3 V. Such an excellent immunity to VDD deviations meets a design specification with respect to inherent coupling losses on transmitting data and power by means of a transcutaneous link.

Fraturas expostas: uma análise das pinturas de "Desconstruções," de Alan Fontes

OpenAIRE

Costa, Alexandre Rodrigues da

2015-01-01

Este artigo se propõe a analisar as pinturas da série Desconstruções, de 2014, do artista mineiro Alan Fontes, a partir dos conceitos de informe e heterogenia de Georges Bataille. Tais conceitos nos permitirão pensar em uma pintura que se detém de maneira crítica sobre a arquitetura, ao tratar a casa como lugar precário, aberto aos acidentes. A casa se constitui, nas pinturas de Alan Fontes, como um espaço de proliferação de sentidos, que se abre, através do dilaceramento, para a desordem, a ...

Distracted While Reading? Changing to a Hard-to-Read Font Shields against the Effects of Environmental Noise and Speech on Text Memory.

Science.gov (United States)

Halin, Niklas

2016-01-01

The purpose of this study was to investigate the distractive effects of background speech, aircraft noise and road traffic noise on text memory and particularly to examine if displaying the texts in a hard-to-read font can shield against the detrimental effects of these types of background sounds. This issue was addressed in an experiment where 56 students read shorter texts about different classes of fictitious creatures (i.e., animals, fishes, birds, and dinosaurs) against a background of the aforementioned background sounds respectively and silence. For half of the participants the texts were displayed in an easy-to-read font (i.e., Times New Roman) and for the other half in a hard-to-read font (i.e., Haettenschweiler). The dependent measure was the proportion correct answers on the multiple-choice tests that followed each sound condition. Participants' performance in the easy-to-read font condition was significantly impaired by all three background sound conditions compared to silence. In contrast, there were no effects of the three background sound conditions compared to silence in the hard-to-read font condition. These results suggest that an increase in task demand-by displaying the text in a hard-to-read font-shields against various types of distracting background sounds by promoting a more steadfast locus-of-attention and by reducing the processing of background sound.

PWM Regulation of Grid-Tied PV System on the Base of Photovoltaic-Fed Diode-Clamped Inverters

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Oleschuk V.I.

2015-12-01

Full Text Available Investigation of grid-tied photovoltaic system on the base of two diode-clamped inverters, controlled by specific algorithms of pulse-width modulation (PWM, has been done. This system includes two strings of photovoltaic panels feeding two diode-clamped inverters. The outputs of inverters are connected with the corresponding windings on the primary side of three-phase transformer, connected with a grid. In order to reduce phase voltage distortion and to increase efficiency of operation of the system, special scheme of control and modulation of inverters has been used, providing minimization of common-mode voltages and voltage waveforms symmetries under different operating conditions. Detailed simulation of processes in this photovoltaic-fed power conversion system has been executed. The results of simulations verify good performance of photovoltaic system regulated in accordance with specific strategy of control and modulation.

A nonlinear adaptive backstepping approach applied to a three phase PWM AC-DC converter feeding induction heating

Science.gov (United States)

Hadri-Hamida, A.; Allag, A.; Hammoudi, M. Y.; Mimoune, S. M.; Zerouali, S.; Ayad, M. Y.; Becherif, M.; Miliani, E.; Miraoui, A.

2009-04-01

This paper presents a new control strategy for a three phase PWM converter, which consists of applying an adaptive nonlinear control. The input-output feedback linearization approach is based on the exact cancellation of the nonlinearity, for this reason, this technique is not efficient, because system parameters can vary. First a nonlinear system modelling is derived with state variables of the input current and the output voltage by using power balance of the input and output, the nonlinear adaptive backstepping control can compensate the nonlinearities in the nominal system and the uncertainties. Simulation results are obtained using Matlab/Simulink. These results show how the adaptive backstepping law updates the system parameters and provide an efficient control design both for tracking and regulation in order to improve the power factor.

Taxas de eventos para as fontes astrofísicas do detector Mario Schenberg

Science.gov (United States)

Castro, C. S.; Araujo, J. C. N.; Miranda, O. D.; Aguiar, O. D.

2003-08-01

O detector de ondas gravitacionais Mario Schenberg será sensível a sinais que cheguem à Terra com amplitude h~10-21 e dentro da faixa em frequências que varia de 3,0 a 3,4 kHz. As principais fontes astrofísicas em condições de gerar um sinal detectável pela antena Schenberg são: colapsos estelares que produzam eventos do tipo supernova; instabilidades hidrodinâmicas em estrelas de nêutrons; excitação dos modos fluído (modos f) de estrelas de nêutrons; excitação dos primeiros modos quadrupolares de buracos negros com massa ~ 3,8 M¤; coalescências de estrelas de nêutrons e buracos negros em sistemas binários e, ainda, espiralações de mini-buracos negros. Neste trabalho nós determinamos as taxas de eventos para o Schenberg associadas a dois tipos de fontes: através da de-excitação dos modos f de estrelas de nêutrons e através da coalescência de mini-buracos negros de 0,5 M¤ (que atualmente têm sido colocados como possíveis candidatos a objetos massivos do halo Galáctico). Nós mostramos que esses tipos de fontes poderão produzir sinais em ondas gravitacionais com uma taxa em torno de um evento por ano dentro da banda do Schenberg.

Evaluation of a health system strengthening initiative in the Zambian prison system

Science.gov (United States)

Sharma, Anjali; Moonga, Clement N; Chileshe, Chisele; Magwende, George; Henostroza, German

2018-01-01

Introduction In 2013, the Zambian Correctional Service (ZCS) partnered with the Centre for Infectious Disease Research in Zambia on the Zambian Prisons Health System Strengthening project, seeking to tackle structural, organisational and cultural weaknesses within the prison health system. We present findings from a nested evaluation of the project impact on high, mid-level and facility-level health governance and health service arrangements in the Zambian Correctional Service. Methods Mixed methods were used, including document review, indepth interviews with ministry (11) and prison facility (6) officials, focus group discussions (12) with male and female inmates in six of the eleven intervention prisons, and participant observation during project workshops and meetings. Ethical clearance and verbal informed consent were obtained for all activities. Analysis incorporated deductive and iterative inductive coding. Results Outcomes: Improved knowledge of the prison health system strengthened political and bureaucratic will to materially address prison health needs. This found expression in a tripartite Memorandum of Understanding between the Ministry of Home Affairs, Ministry of Health (MOH) and Ministry of Community Development, and in the appointment of a permanent liaison between MOH and ZCS. Capacity-building workshops for ZCS Command resulted in strengthened health planning and management outcomes, including doubling ZCS health professional workforce (from 37 to78 between 2014 and 2016), new preservice basic health training for incoming ZCS officers and formation of facility-based prison health committees with a mandate for health promotion and protection. Mechanisms: continuous and facilitated communication among major stakeholders and the emergence of interorganisational trust were critical. Enabling contextual factors included a permissive political environment, a shift within ZCS from a ‘punitive’ to ‘correctional’ organisational culture, and

Desain dan Realisasi Sistem Komunikasi Cahaya Tampak untuk Streaming Teks berbasis PWM

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Trio Adiono

2017-12-01

Full Text Available The design and implementation of visible light communication systems for transmitting digital data (texts have been discussed in this paper. Then, two evaluations were performed also, i.e. the demonstration of streaming text through the visible light as a proof-of-concept system design. The next evaluation is a BER measurement intended to know the VLC system performance quantitatively. The value of BER against the several parameters: by the variation of distance and its reception angle. The proposed VLC system works well until the photodiode reception angle to the LEDs up to 50°. According to evaluation, our system can operate optimally within 30 – 80 cm or 50 – 130 cm of optical channel range depending on the Gain setting option. To support the reliability of noise from ambient light and interference lamps such as fluorescent lamps, the filters circuit are employed: high pass filter and DC-offset remover. Based on the BER analysis, the filters can compensate the problem of ambient light noise (DC-offset signal and interference lamp (100-150 Hz of carrier frequency. The speed of data-rate obtained with 1-PWM modulation and the low-cost analog component is 3.3 kbps.

Situação Energética no Estado do Rio de Janeiro e o Capim-Elefante como Fonte Renovável

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Antonio Alonso Cecon Novo

2016-12-01

Full Text Available Esta revisão aborda a situação energética no Estado do Rio de Janeiro e também outras fontes alternativas de energia que vêm se destacando, como por exemplo, o capim-elefante. Foi realizado um breve relato sobre as fontes para geração de energia que tiveram um papel importante para o setor energético. Dentre as principais fontes para fins energéticos, o capim-elefante tem sido muito utilizado em pesquisas pela Universidade Estadual Norte Fluminense – UENF, na obtenção de cultivares mais produtivas para o desenvolvimento econômico principalmente da região Norte e Noroeste Fluminense. Este trabalho destaca as principais fontes de energia, com ênfase para o capim-elefante na matriz energética, com a produção de biomassa para geração de energia.

A matter of font type: The effect of serifs on the evaluation of scientific abstracts.

Science.gov (United States)

Kaspar, Kai; Wehlitz, Thea; von Knobelsdorff, Sara; Wulf, Tim; von Saldern, Marie Antoinette Oktavie

2015-10-01

Text-based communication is one of the substantial ways of spreading scientific information. While the content and contextual aspects of written words have been widely researched, the impact of font characteristics on text perception is an almost blank page. The following study deals with the influence of serifs on the evaluation of online-presented scientific abstracts. Yet there is only evidence for faster reading times when texts are presented in sans-serif fonts, although the opposite is stated in parts of the literature. The present work examines if the presence or absence of serifs also have an impact on the appraisal of scientific texts when all other important font characteristics do not change. For this purpose, 188 university students participated in an online experiment and rated different aspects of scientific abstracts as well as of the research outlined in the abstracts. The results show that missing serifs led to increased reading speed. However, and in contrast to the perceptual fluency hypothesis, the presence of serifs had a positive effect on all evaluation dimensions. The results of a second study with 187 participants also indicated that reading fluency counteracted the liking of texts. Implications for future studies and media production are discussed. © 2015 International Union of Psychological Science.

Pó de forno elétrico de siderurgia como fonte de micronutrientes e de contaminantes para plantas de milho

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ACCIOLY ADRIANA MARIA DE AGUIAR

2000-01-01

Full Text Available O objetivo deste trabalho foi avaliar o pó de forno elétrico (PFE, resíduo da indústria siderúrgica, como fonte de micronutrientes e contaminantes para o milho, em condições de casa-de-vegetação. Utilizou-se como substrato um Cambissolo álico, onde foram aplicados três níveis de calcário (0, 2 e 4 t ha-1 e cinco tratamentos: sem fornecimento de micronutrientes (testemunha, com fornecimento de micronutrientes via fontes de reagentes p.a., e com 250, 500 e 1.000 kg ha-1 do pó de forno elétrico. A produção de matéria seca só variou significativamente na presença de calagem. Os tratamentos com PFE proporcionaram aumentos na produção de biomassa em relação à testemunha, porém apresentaram resultados inferiores aos proporcionados pela aplicação de micronutrientes via fontes p.a. Não ocorreram diferenças entre os tratamentos na produção de matéria seca do milho com a adição de doses crescentes de PFE. O PFE atuou como fonte de micronutrientes, principalmente de Zn e de Fe. A solubilidade do PFE é sensivelmente maior em condições de maior acidez do solo. A presença de Cd e Pb foi detectada na matéria seca da parte aérea. O risco de contaminação do solo e dos alimentos por metais pesados presentes no PFE pode limitar seu uso agrícola como fonte de micronutrientes.

Fontes de apoio social a idosos portadores de doença pulmonar obstrutiva crônica

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Danyelle Almeida de Andrade

2013-03-01

Full Text Available Este trabalho objetivou identificar e estimular fontes de apoio social a idosos portadores de doença pulmonar obstrutiva crônica. Pautado por uma análise qualitativa e com caráter intervencionista, foi realizado através de quatro oficinas, que foram gravadas e posteriormente transformadas em corpus de discursos submetidos à análise categorial temática de conteúdo. A amostra foi composta por sete idosos (seis homens e uma mulher com média de idade de 70 anos. As temáticas mais recorrentes foram: queixas advindas das limitações impostas pela doença, isolamento e dependência funcional e estímulo das fontes de apoio social. Apesar de a família e os médicos terem sido identificados como as principais fontes de apoio, as dificuldades acarretadas pela enfermidade e o sentimento de incapacidade dificultavam as relações com os familiares e/ou cuidadores e o estabelecimento de novas redes sociais. As oficinas proporcionaram trocas de experiências entre os idosos, desenvolvendo vínculos e promovendo apoio social.

The effect of font size on reading comprehension on second and fifth grade children: bigger is not always better.

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Tami Katzir

Full Text Available Research on reading development has focused on the linguistic, cognitive, and recently, metacognitive skills children must master in order to learn to read. Less focus has been devoted to how the text itself, namely the perceptual features of the words, affects children's learning and comprehension. In this study, we manipulated perceptual properties of text by presenting reading passages in different font sizes, line lengths, and line spacing to 100 children in the second and fifth grades. For second graders (Experiment 1, decreasing font size, as well as increasing line length, yielded significantly lower comprehension scores. Line spacing had no effect on performance. For fifth graders (Experiment 2, decreasing font size yielded higher comprehension scores, yet there were no effects for line length and line spacing. Results are discussed within a "desirable difficulty" approach to reading development.

Jogando o Passado: Videogames como Fontes Históricas * Playing the past: video games as historical sources

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MARCELO CARREIRO

2013-12-01

Full Text Available Resumo: A historiografia contemporânea vem se utilizando, de forma cada vez mais segura, das novas mídias mistas como uma rica fonte histórica – é o caso do cinema e dos quadrinhos. Contudo, essa abertura metodológica a fontes não-textuais ganha nova dimensão com a consolidação da indústria de videogames como uma mídia audiovisual interativa, com elementos das mídias anteriores, mas resultando num caráter próprio. A recente maturidade da mídia, seu alcance demográfico e de mercado, assim como sua condição de arte de massa, colocam os videogames como fonte indispensável para a historiografia do tempo presente.Palavras-chave: Videogame – Fontes – Metodologia – História do tempo presente. Abstract: Contemporary historiography has been using, in an increasingly confident way, new mixed media as a rich historical source – such is the case concerning movies and comics. However, this methodological opening to nontextual sources gains a new dimension with the setting of the video game industry as an interactive audiovisual medium, containing elements of previous media but resulting in a distinctive character. The recent maturity of this medium, its demographics and market reach – as well as its character of mass art – makes video games an indispensable source for the historiography of the present time.Keywords: Video game – Historical sources – Methodology – History of the Present Time.

The effects of age, viewing distance, display type, font type, colour contrast and number of syllables on the legibility of Korean characters.

Science.gov (United States)

Kong, Yong-Ku; Lee, Inseok; Jung, Myung-Chul; Song, Young-Woong

2011-05-01

This study evaluated the effects of age (20s and 60s), viewing distance (50 cm, 200 cm), display type (paper, monitor), font type (Gothic, Ming), colour contrast (black letters on white background, white letters on black background) and number of syllables (one, two) on the legibility of Korean characters by using the four legibility measures (minimum letter size for 100% correctness, maximum letter size for 0% correctness, minimum letter size for the least discomfort and maximum letter size for the most discomfort). Ten subjects in each age group read the four letters presented on a slide (letter size varied from 80 pt to 2 pt). Subjects also subjectively rated the reading discomfort of the letters on a 4-point scale (1 = no discomfort, 4 = most discomfort). According to the ANOVA procedure, age, viewing distance and font type significantly affected the four dependent variables (p fonts were smaller than the Ming fonts. Monitors were smaller than paper for correctness and maximum letter size for the most discomfort. From a comparison of the results for correctness and discomfort, people generally preferred larger letter sizes to those that they could read. The findings of this study may provide basic information for setting a global standard of letter size or font type to improve the legibility of characters written in Korean. STATEMENT OF RELEVANCE: Results obtained in this study will provide basic information and guidelines for setting standards of letter size and font type to improve the legibility of characters written in Korean. Also, the results might offer useful information for people who are working on design of visual displays.

Multi Channels PWM Controller for Thermoelectric Cooler Using a Programmable Logic Device and Lab-Windows CVI

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Eli FLAXER

2008-09-01

Full Text Available We present a complete design of a multi channels PID controller for Thermoelectric Cooler (TEC using a pulse width modulation (PWM technique implemented by a dedicated programmable logic device (PLD programmed by VHDL. The PID control loop is implemented by software written by National Instrument Lab-Windows CVI. Due to the fact that the implementation is by a VHDL and PLD the design is modular, as a result, the circuit is very compact in size and very low cost as compared to any commercial product. In addition, since the control loop is implemented by software running on a personal computer (PC using a C language, it is easy to adjust the controller to various environmental conditions and for a width range of sensors like: a thermo couple (TC, thermistor, resistance temperature detectors (RTD etc. We demonstrate the performance of this circuit as a controller for a small incubator using thermistor as the temperature sensor.

ORGANIC FERTILIZER AS PHOSPHORUS SUPPLIER FOR Brachiaria brizantha CV. MARANDÚ FERTILIZANTE ORGÂNICO COMO FONTE DE FÓSFORO NO CULTIVO INICIAL DE Brachiaria brizantha CV. MARANDÚ

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Diego Henriques Santos

2010-05-01

Full Text Available

font-style: normal; font-weight: normal; line-height: 120%; text-decoration: none;" lang="pt-BR" align="JUSTIFY">font-family: Times New Roman,serif;">font-size: small;">Phosphorus is considered an essential element for plants, but it is found in low amounts in Brazilian soils, mainly in areas destined to pastures, and the application of organic matter contributes to the improvement of physical, chemical and biological soil attributes. The research had the objective of evaluating the application effects of the Bokashi organic compound on soil macro and micronutrients contents and leaves, as well as on Brachiaria brizantha cv. Marandú dry mass yield, evaluating the potential of the organic fertilizer as phosphorus source, in comparison with conventional chemical fertilizers. Different organic compound doses supplied the soil with 17 kg P₂O₅ ha^-1, 34 kg P₂O₅ ha^-1, 68 kg P₂O₅ ha^-1, 136 kg P₂O₅ ha^-1, and 204 kg P₂O₅ ha^-1, comparing it with the conventional chemical fertilizer and the control. The results revealed that the organic fertilizer Bokashi can adequately replace the conventional chemical fertilizer of Brachiaria brizantha cv. Marandú, supplying the soil and plant with appropriate nutrients levels and maintaining the dry mass yield.

font-style: normal; font-weight: normal; line-height: 120%; text-decoration: none;" lang="pt-BR" align="JUSTIFY">font-family: Times New Roman,serif;">font-size: small;">KEY-WORDS: Organic matter; organic fertilizers; plants mineral nutrition; Bokashi

Efeito de diferentes fontes de sílica nos parâmetros texturais da peneira molecular MCM-41

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M. S. B. Fontes

2016-03-01

Full Text Available Resumo Nas últimas décadas, pesquisas estão sendo desenvolvidas para obtenção de materiais eficientes e economicamente viáveis para aplicação em diversos setores da indústria. Os materiais mesoporosos da família MCM-41 estão entre os candidatos eficazes pela facilidade de síntese e estrutura que favorece uma gama de aplicações. O objetivo desse trabalho foi apresentar uma abordagem rítica das características e propriedades dos materiais mesoporosos do tipo MCM-41, enfocando nos aspectos estruturais. Além isso, foram discutidas as vantagens e desvantagens do uso de sílica comerciais e alternativas. As fontes de sílica comerciais analisadas foram sílica gel e TEOS; já as fontes de sílica alternativas foram cinza da casca de arroz, quartzo e pó de vidro. Os materiais analisados foram sintetizados pelo método hidrotérmico e caracterizados por DRX, FTIR, BET e TG. Os resultados apresentados comprovam a eficiência das fontes de sílica alternativas na síntese do MCM-41, pois os materiais apresentaram propriedades texturais dentro dos padrões exigidos. Dessa forma, eles estão aptos a serem testados na indústria em substituição aos MCM-41 sintetizados com fonte de sílica comercial.

Apparatus-Program Complexes Processing and Creation of Essentially non-Format Documents on the Basis of Technology Auto-Adaptive Fonts

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E. G. Andrianova

2014-01-01

Full Text Available The need to translate paper documents into electronic form demanded a development of methods and algorithms for automatic processing systems and web publishing unformatted graphic documents of on-line libraries. Translation of scanned images into modern formats of electronic documents using OCR programmes faces serious difficulties. These difficulties are connected with the standardization set of fonts and design of printed documents. There is also a need to maintain the original form of electronic format of such documents. The article discusses the possibility for building an extensible adaptive dictionary of graphic objects, which constitute unformatted graphics documents. Dictionary automatically adjusted as graphics processing and accumulation of statistical information for each new document. This adaptive extensible dictionary of graphic letters, fonts, and other objects of automated particular document processing is called "auto-adaptive font", and a set of its application methods is named "auto-adaptive font technology."Based on the theory of estimation algorithms, a mathematical model is designed. It allows us to represent all objects of unformatted graphic document in a unified manner to build a feature vector for each object, and evaluate a similarity of these objects in the selected metric. The algorithm of the adaptive models of graphic images is developed and a criterion for combining similar properties in one element to build an auto-adaptive font is offered thus allowing us to build a software core of hardware-software complex for processing the unformatted graphic documents. A standard block diagram of hardware-software complex is developed to process the unformatted graphic documents. The article presents a description of all the blocks of this complex, including document processing station and its interaction with the web server of publishing electronic documents.

Distracted While Reading? Changing to A Hard-to-read Font Shields against the Effects of Environmental Noise and Speech on Text Memory

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Niklas Halin

2016-08-01

Full Text Available The purpose of this study was to investigate the distractive effects of background speech, aircraft noise and road traffic noise on text memory and particularly to examine if displaying the texts in a hard-to-read font can shield against the detrimental effects of these types of background sounds. This issue was addressed in an experiment where 56 students read shorter texts about different classes of fictitious creatures (i.e., animals, fishes, birds, and dinosaurs against a background of the aforementioned background sounds respectively and silence. For half of the participants the texts were displayed in an easy-to-read font (i.e., Times New Roman and for the other half in a hard-to-read font (i.e., Haettenschweiler. The dependent measure was the proportion correct answers on the multiple-choice tests that followed each sound condition. Participants’ performance in the easy-to-read font condition was significantly impaired by all three background sound conditions compared to silence. In contrast, there were no effects of the three background sound conditions compared to silence in the hard-to-read font condition. These results suggest that an increase in task demand—by displaying the text in a hard-to-read font—shields against various types of distracting background sounds by promoting a more steadfast locus-of-attention and by reducing the processing of background sound.

Fontes hidrominerais do Brasil: componentes biologicamente ativos (BAC) naturais

OpenAIRE

Lazzerini, Fábio Tadeu [UNESP

2013-01-01

Os ambientes e recursos naturais de fontes hidrominerais devem fazer parte da governança e planejamento estratégico na saúde pública, meio ambiente, bem estar, turismo e mineração. Na atual política nacional observada em: termalismo social/crenoterapia como prática integrativa complementar da medicina (PIC) através da Portaria Ministério da Saúde 971/2006; na exploração e aplicação das águas minerais prevista pelas Portarias Ministério das Minas e Energia 337/2002 e 127/2011; na implementação...

Impact of frequency modulation ratio on capacitor cells balancing in phase-shifted PWM based chain-link STATCOM

DEFF Research Database (Denmark)

Behrouzian, Ehsan; Bongiorno, Massimo; Teodorescu, Remus

2014-01-01

to provide more uniform power distribution among the cells, two different methods called, a) carrier swapping and b) non-integer frequency modulation ratio are studied. In particular, it is shown that the selection of a non-integer frequency modulation ratio helps in providing a more uniform power......The purpose of this paper is to investigate the impact of switching harmonics on the instantaneous power that flows in the cells of a chain-link based STATCOM when using Phase-Shifted PWM. Two different cases are investigated for the converter cells: low, and high switching frequency. It is shown...... that any deviation from the ideal conditions lead to undesired harmonics, which will impact the charge of the dc capacitors. It is also shown that for low switching frequencies, cells voltage sideband harmonics interact with baseband harmonics of the current and causes extra source of unbalance. In order...

A Novel Application of Zero-Current-Switching Quasiresonant Buck Converter for Battery Chargers

OpenAIRE

Kuo-Kuang Chen

2011-01-01

The main purpose of this paper is to develop a novel application of a resonant switch converter for battery chargers. A zero-current-switching (ZCS) converter with a quasiresonant converter (QRC) was used as the main structure. The proposed ZCS dc–dc battery charger has a straightforward structure, low cost, easy control, and high efficiency. The operating principles and design procedure of the proposed charger are thoroughly analyzed. The optimal values of the resonant components are compute...

Nanosecond-Timescale Intra-Bunch-Train Feedback for the Linear Collider: Results of the FONT2 Run

International Nuclear Information System (INIS)

Barlow, R.; Dufau, M.; Kalinin, A.; Daresbury; Myatt, G.; Perry, C.; Oxford U.; Burrows, P.N.; Hartin, T.; Hussain, S.M.; Molloy, S.; White, G.R.; Queen Mary, U. of London; Adolphsen, C.; Frisch, J.C.; Hendrickson, L.; Jobe, R.K.; Markiewicz, T.; McCormick, D.J.; Nelson, J.; Ross, M.C.; Smith, S.; Smith, T.J.; SLAC

2005-01-01

We report on experimental results from the December 2003/January 2004 data run of the Feedback On Nanosecond Timescales (FONT) experiment at the Next Linear Collider Test Accelerator at SLAC. We built a second-generation prototype intra-train beam-based feedback system incorporating beam position monitors, fast analogue signal processors, a feedback circuit, fast-risetime amplifiers and stripline kickers. We applied a novel real-time charge-normalization scheme to account for beam current variations along the train. We used the system to correct the position of the 170-nanosecond-long bunchtrain at NLCTA. We achieved a latency of 53 nanoseconds, representing a significant improvement on FONT1 (2002), and providing a demonstration of intra-train feedback for the Linear Collider

Moderata Fonte y María Zambrano: por cuenta propia

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Rosa Rius Gatell

2003-01-01

Full Text Available In this paper, Rosa Rius thinks about feminine identity and its history, based on the expressions of freedom of two authors living four centuries apart: the Venetian humanist Moderata Fonte (1555-1592 and the Malagan philosopher María Zambrano (1904-1991. The fact that these women’s freedom is taken as one of their main identifying elements, and straining the historical action of this freedom, unforeseen by the establishment, does not at all imply that the undeniable discrimination inflicted upon women throughout centuries is forgotten or goes on without protest.

O novo Direito Internacional Privado e o conflito de fontes na cooperação jurídica internacional

OpenAIRE

Carvalho Ramos, André de

2013-01-01

O Direito Internacional Privado contemporâneo possui na cooperação jurídica internacional uma de suas áreas de maior dinamismo. A existência de fontes internacionais e internas da cooperação jurídica internacional exige uma análise da solução dos conflitos de fontes. The current Private International Law treats the international legal cooperation as one of its most dynamic subjects. However, the existence of both international and national law sources of legal cooperation requires a study ...

The effect of font size and type on reading performance with Arabic words in normally sighted and simulated cataract subjects.

Science.gov (United States)

Alotaibi, Abdullah Z

2007-05-01

Previous investigations have shown that reading is the most common functional problem reported by patients at a low vision practice. While there have been studies investigating effect of fonts in normal and low vision patients in English, no study has been carried out in Arabic. Additionally, there has been no investigation into the use of optimum print sizes or fonts that should be used in Arabic books and leaflets for low vision patients. Arabic sentences were read by 100 normally sighted volunteers with and without simulated cataract. Subjects read two font types (Times New Roman and Courier) in three different sizes (N8, N10 and N12). The subjects were asked to read the sentences aloud. The reading speed was calculated as number of words read divided by the time taken, while reading rate was calculated as the number of words read correctly divided by the time taken. There was an improvement in reading performance of normally sighted and simulated visually impaired subjects when the print size increased. There was no significant difference in reading performance between the two types of font used at small print size, however the reading rate improved as print size increased with Times New Roman. The results suggest that the use of N12 print in Times New Roman enhanced reading performance in normally sighted and simulated cataract subjects.

Diseño asistido por computadora del patrón de encendido en inversores de tensión, utilizando la técnica de control PWM

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Elio Castro Alfonso

2011-03-01

Full Text Available El artículo se relaciona con el desarrollo de un programa de ayuda para el diseño de los patrones de control deinversores de potencia tipo puente que utilizan técnicas PWM (Pulse Width Modulation. Este método de controlbien establecido, permite incorporar todas las funciones del inversor, pero en lo fundamental garantizar la regulaciónde la tensión de salida manteniendo el factor de distorsión de armónicos lo suficientemente bajo (3-5 % comopara ser tolerado por los consumidores usuales. Obtener un adecuado diseño del patrón de tablas de búsquedapara su utilización en un inversor real empleando microcontrolador, es el problema fundamental a resolver. Losresultados del trabajo han sido comprobados con la ayuda de un procesador 8031.  This paper is related with a program which calculates the control pattern of single-phase power inverters usingPWM techniques.This kind of control if it's well established makes possible to incorporate not all the inverterfunctions,but mainly the voltage regulation by keeping the total harmonics distorsion as low as possible (3-5%;quite good for any consumer.The main problem to solve is to get a proper design of the tables search pattern tobe used in a real single-phase inverter control using any processor.The experimental work has been done usingthe 8031 microcontroller.

Desempenho ponderal de bovinos Nelore suplementados com fontes alternativas de fósforo

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Guilherme Cazerta Lemos

2013-02-01

Full Text Available O desempenho produtivo e a possível interferência do flúor sobre a saúde dos animais foram investigados em bovinos Nelore suplementados, por 866 dias, com distintas fontes alternativas de fósforo com diferentes relações fósforo:fluor (P:F. Os tratamentos experimentais foram: Controle negativo (CONTNEG, sem qualquer suplementação com P, fosfato bicálcico (FB 120:1, FB 30:1 e FB 10:1, fosfato monobicálcico (FMBC 60:1, superfosfato triplo (SFT 30:1 e fosfato de rocha de Cajati (FR 10:1. Foram utilizados 49 novilhos, desmamados aos oito meses de idade, castrados e com 230 kg de peso médio, distribuídos em sete piquetes com água e mistura mineral formulada sem P. A dieta padrão foi feita com bagaço de cana (0,03% de P como volumoso e um concentrado contendo 0,239 % de P oferecido na base de 1% do peso dos animais para permitir um ganho de peso aproximado de 0,50 kg/dia. Até o dia 134, não houve diferença estatística entre os diversos lotes, inclusive para o tratamento CONTNEG, que não recebeu fósforo suplementar na dieta e ganhou 71,6 kg de peso ou 0,633 kg/dia. Após 866 dias de confinamento (2,37 anos, os animais suplementados com o fosfato bicálcico padrão (120:1 ganharam menos peso que os suplementados com as fontes FMCB 60:1, FB 30:1 e SFT 30:1. Até um ano de suplementação fosfórica com fosfato bicálcico padrão (120:1 artificialmente fluoretado com NaF ou com o fosfato de rocha não se detectou danos à saúde ou ao ganho de peso dos animais. As análises de fósforo nos ossos mostraram diferença estatística apenas entre o tratamento CONTNEG e os que tinham fosfato bicálcico. As concentrações de flúor nos ossos se mostraram intimamente associadas à quantidade de flúor disponível nas fontes utilizadas. Conforme a proporção P:F na dieta foi diminuindo, características relacionadas à fluorose dentária ficaram mais evidentes, sendo que os animais que receberam fontes com relação 10:1, apresentaram, ao

Classificação das bases conceituais para elaboração de sistema digital de busca de fontes jornalísticas

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Walter Teixeira Lima Junior

2008-11-01

Full Text Available Este artigo contém a definição de conceitos e revisão bibliográfica da primeira parte da pesquisa de nosso pós-doutorado visando à produção de software para pesquisa e validação qualitativa de fontes de informação jornalística. O texto versa sobre memória biológica, decision making e conceitos fundamentais para escolha de uma fonte jornalística: natureza da fonte, credibilidade, prestígio e atualidade. Eles permeiam e influenciam a escolha (tomada de decisão por parte do profissional que necessita de uma fonte para realizar seu trabalho jornalístico. Foram classificados, categorizados, estruturados e relacionados visando servir de parâmetros confiáveis e consolidados para que um software possa, a partir deles, realizar a tarefa de seleção das melhores opções de fontes jornalísticas, sem que esse processo contenha os vícios apontados por pesquisadores da área. Palavras-chave: fontes jornalísticas; jornalismo; tecnologia; ciências cognitivas; memória biológica Abstract Classification of conceptual bases for the construction of a digital system for searching journalistic sources - This article contains definitions of concepts and bibliographical reviews of the first part of a post-doctoral research aimed at the production of software for the research and qualitative validation of journalistic information sources. The text discusses biological memory, decision-making and fundamental concepts for the choice of a journalistic source: the nature of the source, its credibility, prestige and currentness. These factors imbue and influence the choice (decision-making of the professional seeking a source to carry out his journalistic work. They were classified, categorized, structured and interrelated to serve as reliable and consolidated parameters to enable a software program to perform the task of selecting the best journalistic sources without the errors and problems that researchers of the area have experienced

Avaliação das principais fontes de vibração no meio urbano

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Luiz Antonio Brito

Full Text Available No meio urbano existem diversas fontes de vibração que podem gerar a incomodidade ao ser humano, danos estruturais ou prejudicar o funcionamento de equipamentos sensíveis, como os hospitalares, por exemplo. A principal forma de atenuação da energia vibratória é o aumento da distância entre a fonte e o receptor o que vem sendo reduzido sistematicamente pela especulação imobiliária e invasão das áreas de domínio de ferrovias e rodovias. A forma de propagação da energia vibratória depende da fonte, do tipo de solo e da interação entre as ondas de vibração e a estrutura da edificação. As normas técnicas propõem critérios para avaliar a incomodidade dos usuários e danos estruturais das edificações. O parâmetro de análise da vibração é a velocidade da partícula peak (PVP que é ligada às tensões mecânicas geradas na fundação e estrutura da edificação durante o processo vibratório. O objetivo deste trabalho é avaliar o impacto gerado pelas principais fontes de vibração no meio urbano por meio de medição da velocidade da partícula peak e o cálculo do decaimento da energia vibratória com o aumento da distância. Foram avaliados o tráfego rodoviário, o ferroviário, o processo de cravação de estacas de concreto e metálica e a operação de uma rompedor de concreto movido a ar comprimido. O limite de incomodidade foi superado em todas as análises com exceção da estaca metálica. O limite de danos estruturais foi ultrapassado pelo tráfego ferroviário e operação do bate estacas.

Processamento de biscoitos adicionados de óleo de buriti (Mauritia flexuosa L.: uma alternativa para o consumo de alimentos fontes de vitamina A na merenda escolar

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Jailane de Souza Aquino

2012-12-01

Full Text Available OBJETIVO: Este trabalho teve como objetivo desenvolver biscoitos tipo cookie adicionado de óleo de buriti a fim de se analisarem sua aceitação sensorial e seu valor nutricional, visando a sua utilização na merenda escolar, bem como avaliar o consumo de alimentos fontes de vitamina A por escolares. MÉTODOS: Uma formulação-controle (15% de óleo de soja e duas formulações experimentais (7,5% e 15% de óleo de buriti foram produzidas e avaliadas quanto à composição centesimal, conteúdo de vitamina A e aceitação sensorial, testada por 201 escolares. Avaliou-se também o consumo de alimentos fontes de vitamina A por esses escolares mediante questionário semiquantitativo contendo 28 alimentos considerados fontes da referida vitamina. RESULTADOS: O biscoito elaborado com 15% de óleo de buriti obteve boa aceitação, e apresenta maior percentual de proteínas, de minerais e de vitamina A, podendo ser considerado fonte deste último nutriente. Observou-se uma maior frequência de consumo de alimentos com baixo teor de vitamina A, como também uma menor frequência de consumo dos frutos da região Nordeste. CONCLUSÃO: Os biscoitos adicionados de óleo de buriti podem ser uma alternativa de inclusão de alimentos fontes de vitamina A na dieta de escolares, no entanto o consumo de frutas e hortaliças fontes dessa vitamina deve ser estimulado, tendo em vista que os escolares consomem pouca variedade de alimentos fontes dessa vitamina, o que aumenta o risco de deficiência a longo prazo.

Gênero e nação: a série fontes e a virilização da raça - Gender and nation: the série fontes and the virilization of the race

Directory of Open Access Journals (Sweden)

Cristiani Bereta da Silva, Maria Bernardete Ramos Flores

2011-03-01

Full Text Available O  objetivo desse artigo é fazer  um  exercício de  interpretação  da coleção didática conhecida como Série Fontes, de autoria de Henrique da Silva Fontes (1885-1966, como uma das leituras dadas a ler pela escola no contexto da construção da Nação republicana. Tal coleção foi distribuída gratuitamente na rede de Instrução Pública de Santa Catarina, e adotada também nos estabelecimentos de ensino privados, entre a década de 1920  até meados da década de 1950. Partimos do pressuposto que os manuais didáticos ocuparam  importante  função nas últimas décadas do século XIX e primeiras décadas do século XX, como veículos do projeto        de Estado Nação, respaldado primordialmente no ideário nacionalista. O foco principal da análise será o de perceber como nesse processo de formação de cidadãos e de construção da idéia  de pátria  moderna e civilizada, as pedagogias prescreviam o ethos da virilidade para almejar o progresso da Nação. Palavras-chave: gênero; nação; virilização da raça.   GENDER  AND NATION: THE SÉRIE FONTES AND THE VIRILIZATION OF THE RACE Abstract The aim of this article is to accomplish an exercise of interpretation of the educational collection known as Série Fontes, by Henrique da Silva Fontes (1885-1966, as one of the books given to the students by the school in the  context of the construction  of the republican Nation.   The collection was freely distributed in the public educational system of the state of Santa  Catarina, in  Brazil. It was also adopted in private schools from the  decade of 1920  until  the decade of 1950.   In  this  article  we assume that  the  schoolbooks played an important role as vehicles for the propagation of the State- Nation project and its nationalistic principles during the last decades of the 19th  century and the the first  decades  of the 20th  century. The focus of the analysis  will be identifying

SANTÉ PUBLIQUE Les troubles de santé font fi des frontières – les ...

International Development Research Centre (IDRC) Digital Library (Canada)

SANTÉ PUBLIQUE Les troubles de santé font fi des frontières – les connaissances et les solutions devraient elles ... Dangers du tabac et des narguilés pour la santé ... ÉTUDE DE CAS : Nouvelles armes dans la guerre contre le paludisme.

NECESSIDADE DE MAIOR CRÍTICA ÀS FONTES HISTORIOGRÁFICAS SOBRE OS ÍNDIOS NO BRASIL: CONTRIBUIÇÕES À ETNO-HISTÓRIA, ETNOARQUEOLOGIA E À ARQUEOLOGIA PRÉ-HISTÓRICA

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Rafael Borges Deminicis

2015-06-01

Full Text Available As analogias feitas pelo uso de fontes historiográficas (mapas, imagens, manuscritos etc., principalmente as que abordam os povos indígenas encontrados no Brasil, sem uma metodologia crítica de análise dessas fontes, têm criado algumas armadilhas aos estudos nos campos da etno-história e da etnoarqueologia. Portanto, o que poderia auxiliar no descobrimento da história e das identidades étnicas das inúmeras sociedades tribais remotas ou indígenas sul-americanas, traz cada vez mais encobrimento. Neste sentido, uma dialética serial das fontes se faz extremamente necessária. O panorama do que existe acumulado no Brasil sobre métodos de crítica das fontes historiográficas sobre as sociedades indígenas é extremamente raro, resumindo-se a duas referências: o trabalho de síntese dos grandes contextos sociais de produção das fontes criado pelo sociólogo Florestan Fernandes; e o sistema de observação das particularidades das fontes, a “sociologia dos viajantes”, do antropólogo João Pacheco de Oliveira. Um primeiro passo na direção de uma dialética e serial às referidas fontes seria a combinação desses dois métodos.

Font Size Matters—Emotion and Attention in Cortical Responses to Written Words

OpenAIRE

Bayer, Mareike; Sommer, Werner; Schacht, Annekathrin

2012-01-01

For emotional pictures with fear-, disgust-, or sex-related contents, stimulus size has been shown to increase emotion effects in attention-related event-related potentials (ERPs), presumably reflecting the enhanced biological impact of larger emotion-inducing pictures. If this is true, size should not enhance emotion effects for written words with symbolic and acquired meaning. Here, we investigated ERP effects of font size for emotional and neutral words. While P1 and N1 amplitu...

Pó-de-aciaria como fonte de zinco para o milho e seu efeito na disponibilidade de metais pesados

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Santos Glaucia Cecília Gabrieli dos

2002-01-01

Full Text Available O objetivo deste trabalho foi avaliar o pó-de-aciaria como fonte de zinco para o milho (Zea mays L. e seu efeito no acúmulo e disponibilidade de Cd, Cr, Ni e Pb no solo e nas plantas. O experimento foi realizado em casa de vegetação, utilizando-se dois Latossolos Vermelhos e em dois valores de pH (5,0 e 6,0. As fontes de zinco foram o pó-de-aciaria e o sulfato de zinco aplicados nas doses de 0, 5, 50 e 150 mg.dm-3 de Zn. Fez-se a extração de Zn, Pb, Cd, Cr e Ni do solo utilizando-se as soluções de DTPA e de Mehlich-1. A menor dose de Zn adicionada ao solo, nas duas fontes, proporcionou teores na parte aérea da planta superiores ao nível crítico para a cultura. As concentrações dos metais Pb, Cd, Cr e Ni, tanto na parte aérea como no solo, foram menores que os níveis críticos para toxicidade. Os coeficientes de correlação entre o Zn extraído do solo pelas duas soluções e a concentração de Zn na parte aérea do milho foram significativos e semelhantes para ambos os solos. O mesmo não foi observado para os outros elementos. Conclui-se que, nas condições estudadas, o pó-de-aciaria é uma fonte eficiente de Zn para o milho; os extratores são adequados para determinar a disponibilidade desse elemento, ineficientes, entretanto, para os outros metais estudados. O pH alterou a disponibilidade do Zn diminuindo a disponibilidade com seu aumento.

Variáveis mineralógicas preditoras de fontes de produção de sedimentos, em uma bacia hidrográfica do Rio Grande do Sul

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Pablo Miguel

2014-06-01

Full Text Available O uso da mineralogia como ferramenta para a avaliação das propriedades dos minerais que compõem o solo é extremamente importante para o entendimento das diferentes relações químicas e físicas que ocorrem nele. Essas propriedades/variáveis, na identificação das fontes de sedimentos em suspensão, podem ajudar a elucidar os fatores e processos que regem a transferência de sedimentos e poluentes dos sistemas terrestres para os sistemas aquáticos. Os objetivos deste estudo foram caracterizar quantitativamente a mineralogia do solo das fontes e dos sedimentos em suspensão, em uma bacia hidrográfica, e identificar quais variáveis mineralógicas possuem propriedades traçadoras. Para a identificação das fontes, foi utilizado o método fingerprinting, que compara os solos de diferentes fontes e os sedimentos que são encontrados em suspensão no canal de drenagem, usando elementos traçadores. Os principais minerais que compõem o solo das fontes e do sedimento foram caulinita, minerais de camada 2:1 e hematita e goethita. Entre os óxidos, a hematita foi o que predominou entre as amostras. As variáveis mineralógicas, teor de caulinita e de goethita apresentaram capacidade discriminante e puderam ser usados como traçadores na identificação das fontes de produção de sedimentos e na estimativa da contribuição de cada uma das fontes, aumentando assim a capacidade preditiva do modelo. A maior contribuição na produção de sedimentos foi dos canais fluviais, seguidos pela malha e, por último, pelas estradas.

Renditions of Faithfulness; from Jorge Calvetti’s Poetry to Gustavo Fontán’s Films.

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Adriana C. Cid

2015-04-01

Full Text Available An original and sensitive filmmaker, Gustavo Fontán goes beyond classic transpositions to venture into a poet’s obsessions, aesthetic and atmospheres. He has done so with the work of Jacobo Fijman, Juan L. Ortiz and Jorge Calvetti – to name just a few. In this paper I intend to explore El paisaje invisible, a short film by Fontán that brings us closer to Calvetti. I will focus on the director’s strategies – characteristic of the cinematographic language - that convey the poet’s mythical world and aesthetic, and I will analyze the union of both artists’ poetics. Finally, I would like to offer a brief explanation of the title of this article, which is drawn from a reflection by Calvetti: “All inspiration is born with its own form or forms. The same subject can be written as a narrative or in verse. Why not? They are different renditions of faithfulness.” I believe cinema is another rendition.

A queda do muro de Berlim: um estudo com fontes brasileiras

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Carlos Federico Domínguez Ávila

2010-10-01

Full Text Available O artigo explora os acontecimentos que resultaram na queda do muro de Berlim, bem como algumas das suas mais importantes conseqüências, inclusive no que diz respeito à reunificação alemã, em 1990. O texto utiliza prioritariamente fontes primárias resgatadas no Arquivo Histórico do Ministério das Relações Exteriores do Brasil - após vários anos de resguardo legal. Também são utilizadas fontes secundárias - isto é, literatura especializada na temática publicada no Brasil e no exterior. Analiticamente o artigo constata a transcendental relevância da queda do muro de Berlim e eventos subseqüentes, tanto na própria Alemanha, quanto na Europa e no mundo. Nessa linha, o texto alude ao colapso político e econômico da República Democrática da Alemanha (RDA, aos atores fundamentais que levaram ao esboroamento do muro, aos condicionantes domésticos, inter-alemães, europeus e globais que incidiram no processo de reunificação da nação alemã e aos dilemas específicos da cidade de Berlim no contexto geral da reunificação germânica. O trabalho inclui uma pós-data de novembro de 2009, em que se comenta brevemente as comemorações do vigésimo aniversário da queda do muro de Berlim.

“Fontes para a história dos museus de arte em Portugal”. Um projeto, muitos projetos…

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Luís Soares

2013-04-01

Full Text Available Este artigo tem como objetivo dar notícia das atividades que estão a ser desenvolvidas no âmbito do projeto “Fontes para a História dos Museus de Arte em Portugal” e que se centram no estudo, sistematização e divulgação de fontes documentais relacionadas com a criação e atividade dos museus de arte em Portugal. Sendo esta uma investigação inédita no campo da Museologia e da História da Arte no nosso país, definiu-se como prioritária a documentação associada a instituições de referência da museologia e da formação de coleções públicas, que se ligam também aos primórdios dos museus de arte portugueses: a Academia Nacional de Belas-Artes, o Museu Nacional de Arte Antiga e o Palácio Nacional da Ajuda. Este projeto abarca ainda a segunda metade do século XX, contemplando a ação da Fundação Calouste Gulbenkian nas artes plásticas. Pretende-se, deste modo, criar novos pontos de partida, fundamentados pela análise das fontes primárias, para a elaboração de uma História dos Museus em Portugal.

Reading on the Computer Screen: Does Font Type Have Effects on Web Text Readability?

Science.gov (United States)

Ali, Ahmad Zamzuri Mohamad; Wahid, Rahani; Samsudin, Khairulanuar; Idris, Muhammad Zaffwan

2013-01-01

Reading on the World Wide Web has become a daily habit nowadays. This can be seen from the perspective of changes in readers' tendency to be more interested in materials from the internet, than printed media. Taking these developments into account, it is important for web-based instructional designers to choose the appropriate font, especially for…

As fontes de Duarte Pacheco Pereira no "Esmeraldo de Situ Orbis" (IV

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Joaquim Barradas de Carvalho

1966-06-01

Full Text Available A História Natural de Plínio é logo após o De Situ Orbis de Pompônio Mela, a fonte mais importante de Duarte Pacheco Pereira no seu Esmeraldo de situ orbis. Encontramos no texto da obra de Duarte Pacheco vinte e sete passos em que, de maneira explícita ou não, verificamos nitidamente a influência de Plínio e da sua História Natural.

EFEITO DE FONTES E DOSES DE NITROGÊNIO NA REAÇÃO DA CULTIVAR DE TRIGO BR 14 À Septoria nodorum

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Eduardo Dânia Ugalde

1993-04-01

Full Text Available O experimento foi conduzido em casa de vegetação da UFSM no período de maio a outubro de 1989. Três plantas de trigo, cultivar BR 14, foram cultivadas em cada vaso (6 litros com Solo Podzólico Vermelho Amarelo (Unidade de Mapeamento São Pedro, com 70% da capacidade de campo, constituindo a unidade experimental. O delineamento experimental foi inteiramente casualizado, sendo que os tratamentos foram fontes e doses de N, e inoculação das plantas com Septoria nodorum, constituindo um trifatorial com três repetições. As fontes de nitrogênio utilizadas foram uréia e salitre do Chile nas doses de 30, 60, 90 e 120kg/ha de N, sendo parte aplicado na semeadura (30% e o restante (70% no estádio 2 (início do afilhamento da escala proposta por LARGE (1956. Os tratamentos que não foram inoculados com Septoria nodorum apresentaram maior percentagem de N no tecido, o que parece não ter sido afetado tanto com relação a fonte de nitrogênio nem quanto a dose utilizada. O teor de matéria seca, sendo consideradas plantas inoculadas e não inoculadas, não diferiu tanto para fontes como para doses de nitrogênio (kg/ha. A severidade da doença foi maior em plantas que receberam maiores doses de adubação nitrogenada.

Uso da alga Lithothamnium calcareum como fonte alternativa de cálcio nas rações de frangos de corte

OpenAIRE

Carlos,André Carreira; Sakomura,Nilva Kazue; Pinheiro,Sandra Regina Freitas; Toledano,Fernando Marcelo Micai; Giacometti,Renato; Silva Júnior,José Walter da

2011-01-01

Objetivou-se, com este trabalho, avaliar o uso da alga Lithothamnium calcareum (Pallas) Areschoug nas rações para frangos de corte de 1 a 21 e 21 a 42 dias de idade, em substituição à fonte de cálcio tradicional (calcário calcítico). Para isso, foram utilizados 300 pintos machos, da linhagem Cobb®, que receberam rações contendo o calcário calcítico e a alga Lithothamnium calcareum (colhida de inteira e na forma de areia biodentrítica) como fontes de cálcio. O delineamento experimental utiliza...

Harmonic Analyzing of the Double PWM Converter in DFIG Based on Mathematical Model

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Jing Liu

2017-12-01

Full Text Available Harmonic pollution of double fed induction generators (DFIGs has become a vital concern for its undesirable effects on power quality issues of wind generation systems and grid-connected system, and the double pulse width modulation (PWMconverter is one of the main harmonic sources in DFIGs. Thus the harmonic analysis of the converter in DFIGs is a necessary step to evaluate their harmonic pollution of DFIGs. This paper proposes a detailed harmonic modeling method to discuss the main harmonic components in a converter. In general the harmonic modeling could be divided into the low-order harmonic part (up to 30th order and the high-order harmonic part (greater than order 30 parts in general. The low-order harmonics are produced by the circuit topology and control algorithm, and the harmonic component will be different if the control strategy changes. The high-order harmonics are produced by the modulation of the switching function to the dc variable. In this paper, the low-order harmonic modeling is established according to the directions of power flow under the vector control (VC, and the high-order harmonic modeling is established by the switching function of space vector PWM and dc currents. Meanwhile, the simulations of harmonic a components in a converter are accomplished in a real time digital simulation system. The results indicate that the proposed modeling could effectively show the harmonics distribution of the converter in DFIGs.

Disponibilidade biológica do fósforo de diferentes fontes para eqüinos em crescimento

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FURTADO CARLOS EDUARDO

2000-01-01

Full Text Available Objetivou-se neste estudo, determinar a disponibilidade biológica do P de diferentes fontes, para eqüinos em fase de crescimento. Utilizaram-se dezesseis eqüinos machos em fase de crescimento, submetidos à aplicação de quatro fontes fosfatadas -- fosfato de rocha de Tapira (TAP, fosfato de rocha de Patos de Minas (PAT, fosfato bicálcico (BIC e farinha de osso (FOS --, adicionadas à dieta basal em quantidades suficientes para fornecer 22 g de P/animal/dia. No 16º dia, foram-lhes injetados 30 MBq de 32P/animal, e coletaram-se amostras de sangue, fezes e urina, durante sete dias. Foram determinadas as atividades específicas no plasma, fezes e urina e calculou-se a perda endógena fecal e a absorção real de P. Os valores obtidos quanto ao P consumido, P excretado, P no plasma e P retido não apresentaram diferenças estatísticas (P>0,05. Os valores de absorção real do P do TAP, PAT, BIC e da FOS foram, respectivamente, 25,23%, 33,97%, 31,71% e 29,36%. Não houve diferenças estatísticas (P>0,05 entre as fontes estudadas. Em relação ao BIC, as rochas fosfáticas apresentaram altos valores de disponibilidade biológica.

Contribuição das fontes de sedimentos em uma bacia hidrográfica agrícola sob plantio direto

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Tales Tiecher

2014-04-01

Full Text Available O conhecimento das principais fontes difusas de produção de sedimento pode aumentar a eficiência de utilização dos recursos públicos, investidos em estratégias de gestão em bacias hidrográficas, que visem mitigar a transferência de sedimentos aos cursos d'água. Objetivou-se com este trabalho avaliar as fontes de sedimentos numa bacia hidrográfica rural de cabeceira com predomínio de cultivos anuais sob plantio direto e com intensa e inadequada exploração dos recursos naturais, por meio da quantificação da contribuição relativa das estradas e das lavouras na produção global de sedimentos. A bacia hidrográfica está localizada no município de Júlio de Castilhos, Rio Grande do Sul. O período de estudo foi de maio de 2009 a abril de 2011. Para a identificação das fontes, foi utilizado o método fingerprinting, que compara os solos de diferentes fontes e os sedimentos que são encontrados em suspensão no canal de drenagem, usando elementos traçadores. O manejo inadequado do solo nas áreas de lavoura, a falta de planejamento das vias de acesso e a ausência de práticas de controle do escoamento superficial, que sejam compatíveis com a fragilidade condicionada pelos solos e pelo relevo da bacia hidrográfica, têm provocado o surgimento de processos erosivos acelerados com efeitos negativos ao agricultor e à sociedade. As estradas apresentam alta porcentagem de contribuição na transferência de sedimentos, mas a contribuição das áreas de lavoura aumenta em precipitações pluviais de alta magnitude. Isso evidencia que a magnitude dos eventos de chuva influencia a proporção de contribuição entre as fontes ao longo do ano na bacia hidrográfica, interferindo no processo de mobilização de sedimentos e nutrientes em direção à rede de drenagem.

As fontes literárias no ensino de História

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Joan Pagès Blanch

2013-07-01

Full Text Available Existem muitos recursos para levar aos alunos do ensino fundamental e médio o conhecimento e a compreensão do passado, boa parte deles são habitualmente utilizados nas salas de aula. Provavelmente um dos recursos com mais potencialidades educativas é a literatura e, em especial, o romance. Neste artigo propomos que a literatura pode contribuir para a aprendizagem do passado e qual é o valor educativo das fontes literárias no ensino de história e a sugestão de algumas ideias para o seu tratamento na prática.

Development of Digital Hysteresis Current Control with PLL Loop Gain Compensation Strategy for PWM Inverters with Constant Switching Frequency

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N. Belhaouchet

2008-03-01

Full Text Available Hysteresis current control is one of the simplest techniques used to control the magnitude and phase angle of motor current for motor drives systems. However, this technique presents several disadvantages such as operation at variable switching frequency which can reveal problems of filtering, interference between the phases in the case of the three-phase systems with insulated neutral connection or delta connection, and irregularity of the modulation pulses which especially causes an acoustic noise on the level of the machine for the high power drive. In this paper, a new technique is proposed for a variable-hysteresis-band controller based on dead beat control applied to three phase voltage source PWM inverters feeding AC motors. Its main aim is firstly ensure a constant switching frequency and secondly the synchronization of modulation pulses using the phase-locked-loop with loop gain compensation in order to ensure a better stability. The behavior of the proposed technique is verified by simulation.

Fontes de Sódio e Relação Sódio: Cloro para Frangos de Corte Sodium Chloride Levels in Broiler Diets

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AV Fischer da Silva

2000-04-01

Full Text Available Foram utilizados 2.880 pintos de corte, para avaliar os efeitos de diferentes fontes de sódio (Na+ e relações sódio:cloro (Na+:Cl- na ração. As aves receberam ração e água ad libtum. O delineamento experimental foi inteiramente casualizado, com quatro tratamentos e seis repetições. O ganho de peso, consumo de ração, conversão alimentar e mortalidade não foram influenciados (p>0,05 pela substituição da fonte tradicional de Na e pelas diferentes relações Na:Cl. A umidade da cama foi afetada pela fonte e níveis de Na na ração. Os resultados mostraram que pode-se utilizar o NaHCO3 como fonte parcial à exigência de Na para frangos de corte de 1 a 47 dias de idade.A trial was carried out with 2,880 day old chicks to evaluate different sources of sodium (Na+ and Na+:Cl- ratio in diets. Water and diets were available in "ad libitum" feeding. Experimental design was completely randomized with four treatments and six repetitions. The performance (feed intake, body weight, feed conversion and mortality was not affected (P>0.05 by treatments, but different levels and sources of Na+ increased litter moisture. The NaHCO3 can be used in chicken broilers diets in partial substitution of Na for day 1 to 47.

Fontes de energias alternativas e os desafios para a cadeia produtiva automotiva

OpenAIRE

Alves, Marcelo Ivanildo dos Santos

2011-01-01

Resumo: A indústria automotiva sempre esteve envolta num processo permanente de inovações e mais recentemente ela vem passando por várias e importantes mudanças. Essas mudanças decorrem de três fatores fundamentais: motivações ambientais, preço do petróleo e novos mercados. Num cenário de aperfeiçoamento dos padrões atuais de propulsão veicular, percebe-se o surgimento de fontes de energias alternativas. Onde o etanol surge como alternativa e poderá ser adotado em determinados mercados, como ...

Inverter Output Filter Effect on PWM Motor Drives of a Flywheel Energy Storage System

Science.gov (United States)

Santiago, Walter

2004-01-01

NASA Glenn Research Center (GRC) has been involved in the research and development of high speed flywheel systems for small satellite energy storage and attitude control applications. One research and development area has been the minimization of the switching noise produced by the pulsed width modulated (PWM) inverter that drives the flywheel permanent magnet motor/generator (PM M/G). This noise can interfere with the flywheel M/G hardware and the system avionics hampering the full speed performance of the flywheel system. One way to attenuate the inverter switching noise is by placing an AC filter at the three phase output terminals of the inverter with the filter neutral point connected to the DC link (DC bus) midpoint capacitors. The main benefit of using an AC filter in this fashion is the significant reduction of the inverter s high dv/dt switching and its harmonics components. Additionally, common mode (CM) and differential mode (DM) voltages caused by the inverter s high dv/dt switching are also reduced. Several topologies of AC filters have been implemented and compared. One AC filter topology consists of a two-stage R-L-C low pass filter. The other topology consists of the same two-stage R-L-C low pass filter with a series connected trap filter (an inductor and capacitor connected in parallel). This paper presents the analysis, design and experimental results of these AC filter topologies and the comparison between the no filter case and conventional AC filter.

Nova história da administração pública brasileira: pressupostos teóricos e fontes alternativas

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Frederico Lustosa da Costa

2016-04-01

Full Text Available Resumo: Nos últimos anos, diversas iniciativas isoladas assinalam a redescoberta da história da administração pública e a utilidade do seu estudo para a compreensão do Estado contemporâneo como ordem social, instituição e representação. Esses trabalhos representam um avanço com relação à produção historiográfica publicada até os anos 1980. Entretanto, ainda persistem fragilidades conceituais e metodológicas que pouco a pouco começam a ser superadas. Além disso, uma das maiores dificuldades dos pesquisadores que se engajam nesse esforço é a identificação e o acesso a fontes mais diversificadas para a elaboração de uma nova história da administração pública, baseada nos avanços da historiografia mais recente. Este artigo se propõe a discutir pressupostos teórico-metodológicos para o desenvolvimento dessa nova história e contribuir para a identificação, apresentação e análise dessas fontes. A partir da indicação desses pressupostos, do estabelecimento de uma periodização da história do Estado brasileiro e da identificação de temas emergentes, foram definidas seis categorias em que as fontes podem, num primeiro momento, ser enquadradas para agrupar temas, acervos ou bases de dados, a saber: repertório das leis sobre organização governamental; falas do trono e mensagens presidenciais; relatórios do TCU; estatísticas; arquivos pessoais; histórias de vida. O levantamento não pretende apresentar fontes totalmente inéditas nem ser exaustivo, mas oferecer pistas para a utilização de materiais ainda muito poucos usuais em estudos sobre história da administração pública.

Efeito da fonte de amido e do manejo alimentar no controle da glicemia em cães com diabete mellitus naturalmente adquirida

OpenAIRE

Teshima, Eliana [UNESP

2010-01-01

A diabetes mellitus (DM) é uma das endocrinopatias mais comuns em cães, sendo o tratamento um desafio. As fibras dietéticas têm sido relatadas como benéficas no auxílio do controle glicêmico de cães diabéticos, mas nenhum trabalho faz referência aos efeitos de diferentes fontes de amido sobre a resposta glicêmica nesses animais. Neste trabalho, objetivou-se estudar os efeitos de duas diferentes fontes de amido (arroz e sorgo) em dietas com teor moderado de fibra sobre o controle glicêmico de ...

Design and implementation of a digital clock showing digits in Bangla font using microcontroller AT89C4051

OpenAIRE

Muslim, Nasif; Adnan, Md. Tanvir; Kabir, Mohammad Zahidul; Kabir, Md. Humayun; Islam, Sheikh Mominul

2012-01-01

In this paper, a digital clock is designed where the microcontroller is used for timing controller and the font of the Bangla digits are designed, and programmed within the microcontroller. The design is cost effective, simple and easy for maintenance.

Para cada universo colecionista, suas fontes: dinâmicas informacionais nas tramas de Clifford Janeway

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Kelly Castelo Branco da Silva Melo

2017-09-01

Full Text Available O artigo parte do pressuposto que a literatura policial, como modo de registro e expressão de experiências ficcionais, ela mesma também considerada, nos estudos das áreas de Biblioteconomia e Ciência da Informação, uma fonte de informação, constitui-se de uma abordagem que torna possível a análise/interpretação e representação de quadros de referências sócio-históricas e, mais especificamente, de determinadas práticas colecionistas. Como desdobramento de estudos sobre bibliofilia em Memória Social, o artigo toma como campo empírico cinco romances policiais escritos pelo norte-americano John Dunning. Por meio da leitura analítica desses livros, propõe teórica e metodologicamente identificar, recortar e descrever as fontes de informação julgadas relevantes para as dinâmicas das tramas, visando elucidar o que é possível depreender do universo bibliófilo, e o que, nesse universo ficcional, constitui e representa práticas informacionais utilizadas por/em um universo colecionista não ficcional.

The FONT5 Bunch-by-Bunch Position and Angle Feedback System at ATF2

Science.gov (United States)

Apsimon, R. J.; Bett, D. R.; Burrows, P. N.; Christian, G. B.; Constance, B.; Davis, M. R.; Gerbershagen, A.; Perry, C.; Resta-Lopez, J.

The FONT5 upstream beam-based feedback system at ATF2 is designed to correct the position and angle jitter at the entrance to the ATF2 final-focus system, and also to demonstrate a prototype intra-train feedback system for the International Linear Collider interaction point. We discuss the hardware, from stripline BPMs to kickers, and RF and digital signal processing, as well as presenting results from the latest beam tests at ATF2.

Development of an On-Line Self-Tuning FPGA-PID-PWM Control Algorithm Design for DC-DC Buck Converter in Mobile Applications

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Ahmed Sabah Al-Araji

2017-08-01

Full Text Available This paper presents a new development of an on-line hybrid self-tuning control algorithm of the Field Programmable Gate Array - Proportional Integral Derivative - Pulse Width Modulation (FPGA-PID-PWM controller for DC-DC buck converter which is used in battery operation of mobile applications. The main goal in this work is to propose structure of the hybrid Bees-PSO tuning control algorithm which has a capability of quickly and precisely searching in the global regions in order to obtain optimal gain parameters for the proposed controller to generate the best voltage control action to achieve the desired performance of the Buck converter output. Matlab simulation results and Xilinx development tool Integrated Software Environment (ISE experimental work show the robustness and effectiveness of the proposed on-line hybrid Bees-PSO tuning control algorithm in terms of obtaining smooth and unsaturated state voltage control action and minimizing the tracking voltage error of the Buck converter output. Moreover, the fitness evaluation number is reduced.

Fontes primárias no ensino de física: considerações e exemplos de propostas

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Giovanninni Leite de Freitas Batista

2015-10-01

Full Text Available http://dx.doi.org/10.5007/2175-7941.2015v32n3p663 Em contraste com a tendência positivista de outrora, fontes primárias não são mais consideradas como documentos oficiais que contém “a verdade sobre o passado”. Atualmente, são compreendidas como artefatos culturalmente produzidos que refletem intencionalidades de personagens. São essenciais para o trabalho interpretativo realizado por historiadores e historiadores da ciência. No contexto educacional, na disciplina escolar de História, os estudantes já costumam ser convidados a uma interpretação diacrônica de documentos históricos. De modo distinto, o uso desse tipo de material é ainda raro em iniciativas para a inserção da História e Filosofia da Ciência no ensino de Física. Adicionalmente, há lacunas quanto a refletir sobre o uso didático dessas fontes em aulas de Física numa perspectiva não ilustrativa, mas sim investigativa, a qual estaria em ressonância com pressupostos historiográficos da História da Ciência e objetivos didáticos atualizados. Atividades investigativas, dialógicas, baseadas na interpretação diacrônica de documentos podem incentivar a curiosidade e a imaginação dos alunos acerca do processo de construção do conhecimento científico, evocando elementos usualmente ausentes em livros didáticos. O presente artigo reflete sobre tais questões e discute dois exemplos de possibilidades didáticas de uso de fontes primárias relacionadas à História do Vácuo e da Pressão Atmosférica.

Design of the ILC Prototype FONT4 Digital Intra-Train Beam-Based Feedback System

International Nuclear Information System (INIS)

Burrows, P.; Queen Mary, U. of London; Christian, G.B.; Hartin, A.F.; Dabiri Khah, H.; White, G.R.; Oxford U.; Clarke, C.C.; Perry, C.; Oxford Instruments; Kalinin, A.; Daresbury; McCormick, D.J.; Molloy, S.; Ross, M.C.; SLAC

2007-01-01

We present the design of the FONT4 digital intra-train beam position feedback system prototype and preliminary results of initial beam tests at the Accelerator Test Facility (ATF) at KEK. The feedback system incorporates a fast analogue beam position monitor (BPM) front-end signal processor, a digital feedback board, and a kicker driver amplifier. The short bunchtrain, comprising 3 electron bunches separated by c. 150ns, in the ATF extraction line was used to test components of the prototype feedback system

FLAVONÓIS E FLAVONAS: FONTES BRASILEIRAS E FATORES QUE INFLUENCIAM A COMPOSIÇÃO EM ALIMENTOS

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L. S. HUBER

2008-12-01

Full Text Available

O interesse em pesquisar os flavonóides se deve a estudos que indicam efeitos benéfi cos à saúde, principalmente na prevenção de doenças degenerativas, como câncer e doenças cardiovasculares. A determinação dos flavonóides em alimentos, bem como a investigação dos fatores que influenciam a composição, são necessários para apontar as fontes e otimizar as condições de produção, processamento e estocagem, a fi m de manter ou incrementar seus teores na dieta da população, para promoção da saúde. Os chás preto e verde e a erva mate são muito ricos em quercetina, sendo os dois primeiros fontes também de miricetina e kaempferol e o último de kaempferol. As melhores fontes entre as frutas são pitanga e caju, que contém quercetina, kaempferol e miricetina; acerola, tendo quercetina e kaempferol, e taperebá e maçã com altos conteúdos de quercetina. Entre as hortaliças consumidas no Brasil, as principais fontes são cebola, couve e rúcula, com altos teores de quercetina, rúcula e couve com altos níveis de kaempferol, e salsa com grande quantidade de apigenina. Os teores de flavonóides nos alimentos são determinados geneticamente, porém, são influenciados também por fatores como estação do ano, clima, composição do solo, estádio de maturação, preparo, processamento e estocagem dos alimentos.

A new type of accelerator power supply based on voltage-type space vector PWM rectification technology

International Nuclear Information System (INIS)

Wu, Fengjun; Gao, Daqing; Shi, Chunfeng; Huang, Yuzhen; Cui, Yuan; Yan, Hongbin; Zhang, Huajian; Wang, Bin; Li, Xiaohui

2016-01-01

To solve the problems such as low input power factor, a large number of AC current harmonics and instable DC bus voltage due to the diode or thyristor rectifier used in an accelerator power supply, particularly in the Heavy Ion Research Facility in Lanzhou-Cooler Storage Ring (HIRFL-CSR), we designed and built up a new type of accelerator power supply prototype base on voltage-type space vector PWM (SVPWM) rectification technology. All the control strategies are developed in TMS320C28346, which is a digital signal processor from TI. The experimental results indicate that an accelerator power supply with a SVPWM rectifier can solve the problems above well, and the output performance such as stability, tracking error and ripple current meet the requirements of the design. The achievement of prototype confirms that applying voltage-type SVPWM rectification technology in an accelerator power supply is feasible; and it provides a good reference for design and build of this new type of power supply. - Highlights: • Applying SVPWM rectification technology in an accelerator power supply improves its grid-side performance. • New Topology and its control strategies make an accelerator power supply have bidirectional power flow ability. • Hardware and software of controller provide a good reference for design of this new type of power supply.

A new type of accelerator power supply based on voltage-type space vector PWM rectification technology

Energy Technology Data Exchange (ETDEWEB)

Wu, Fengjun, E-mail: wufengjun@impcas.ac.cn [Institute of Modern Physics, CAS, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Gao, Daqing; Shi, Chunfeng; Huang, Yuzhen [Institute of Modern Physics, CAS, Lanzhou 730000 (China); Cui, Yuan [Institute of Modern Physics, CAS, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Yan, Hongbin [Institute of Modern Physics, CAS, Lanzhou 730000 (China); Zhang, Huajian [Institute of Modern Physics, CAS, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Wang, Bin [University of Chinese Academy of Sciences, Beijing 100049 (China); Li, Xiaohui [Institute of Modern Physics, CAS, Lanzhou 730000 (China)

2016-08-01

To solve the problems such as low input power factor, a large number of AC current harmonics and instable DC bus voltage due to the diode or thyristor rectifier used in an accelerator power supply, particularly in the Heavy Ion Research Facility in Lanzhou-Cooler Storage Ring (HIRFL-CSR), we designed and built up a new type of accelerator power supply prototype base on voltage-type space vector PWM (SVPWM) rectification technology. All the control strategies are developed in TMS320C28346, which is a digital signal processor from TI. The experimental results indicate that an accelerator power supply with a SVPWM rectifier can solve the problems above well, and the output performance such as stability, tracking error and ripple current meet the requirements of the design. The achievement of prototype confirms that applying voltage-type SVPWM rectification technology in an accelerator power supply is feasible; and it provides a good reference for design and build of this new type of power supply. - Highlights: • Applying SVPWM rectification technology in an accelerator power supply improves its grid-side performance. • New Topology and its control strategies make an accelerator power supply have bidirectional power flow ability. • Hardware and software of controller provide a good reference for design of this new type of power supply.

DESENVOLVIMENTO E COMPOSIÇÃO CORPORAL DE ALEVINOS DE JUNDIÁ (Rhamdia quelen ALIMENTADOS COM DIETAS CONTENDO DIFERENTES FONTES DE LIPÍDIOS

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Melo José Fernando Bibiano

2002-01-01

Full Text Available Foram testadas três fontes de lipídios em rações experimentais para juvenis de jundiá Rhamdia quelen com a inclusão de 5% na dieta de óleo de canola (T1, óleo de fígado de bacalhau (T2 ou banha suína (T3, usando o delineamento inteiramente casualizado com três tratamentos e três repetições. O desempenho e o rendimento de carcaça não foram afetados pelas fontes de lipídios testadas, porém estas influenciaram na maior deposição de proteína na carcaça dos peixes do tratamento T1 e de gordura na carcaça no tratamento T3.

Fontes alimentares de Triatoma pseudomaculata no Estado do Ceará, Brasil

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Simone Patrícia Carneiro Freitas

2005-01-01

Full Text Available OBJETIVO: Triatoma pseudomaculata, espécie peridomiciliar, é encontrada apresentando baixa taxa de infecção por Trypanosoma cruzi. Com o objetivo de identificar os possíveis reservatórios de T. cruzi, investigou-se a ocorrência desse triatomíneo no domicílio, bem como suas fontes alimentares. MÉTODOS: De janeiro de 2001 a julho de 2002 foram capturados 921 espécimes de T. pseudomaculata em 13 municípios do sul do Estado do Ceará. O conteúdo intestinal dos triatomíneos foi retirado, espalhado em disco de papel de filtro e analisado por precipitina para os seguintes anti-soros: ave, roedor, cão, gambá, lagarto, boi/cabra, gato, porco, barata e humano. A investigação da presença de T. cruzi foi feita observando-se parte do conteúdo intestinal dos insetos a fresco, entre lâmina e lamínula, e pela sua semeadura em meio de cultura. RESULTADOS: Do total examinado, 184 (90,6% foram positivos para os anti-soros testados: ave (62,5%> roedor (33,7%> cão (20,1%> gambá (9,8%> lagarto (5%> boi-cabra (5%> gato (2,7%> porco (2,2%> barata (2,2%> humano (1,6%. As alimentações variaram de zero (não reagiram a quatro da seguinte forma: não reagiram (9,4%, uma (57,1%, duas (26%, três (7% ou quatro (0,5%. Das fontes alimentares identificadas apenas três espécimes (1,6% foram positivos para T. cruzi. CONCLUSÕES: A baixa incidência de sangue humano mostra que T. pseudomaculata está bem adaptado ao peridomicílio. Porém, a vigilância epidemiológica na região sul do Estado do Ceará se faz necessária tendo em vista a proximidade da espécie ao domicílio.

FONTES DE FÓSFORO PARA ADUBAÇÃO DE CANA-DE-AÇÚCAR FORRAGEIRA NO CERRADO PHOSPHORUS SOURCES FOR SUGARCANE FORAGE CULTIVARS FERTILIZATION IN THE BRAZILIAN SAVANNAH

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Cleiton Gredson Sabin Benett

2011-01-01

Full Text Available

font-style: normal; font-weight: normal; line-height: 120%; text-decoration: none;" lang="pt-BR" align="JUSTIFY">font-family: Times New Roman,serif;">font-size: small;">Com a expansão da cana-de-açúcar em áreas de Cerrado, há necessidade de se estudar o manejo da adubação, principalmente do fósforo (P, pois é o nutriente que mais limita a produção, neste ecossistema. Objetivou-se, com este trabalho, comparar o efeito de fontes de fósforo (P, em duas variedades de cana-de-açúcar. O experimento foi realizado em Alta Floresta (MT, em Latossolo Vermelho-Amarelo distrófico. O delineamento experimental utilizado foi o de blocos casualizados, em esquema fatorial 4x2, sendo avaliados os fatores fontes de P (farinha de ossos, fosfato de Arad e superfosfato triplo, na dose de 100 kg de P₂O₅ ha^-1, acrescidas de uma testemunha sem aplicação do nutriente, e as variedades IAC 86 2480 e SP 79 101, com quatro repetições. Foram avaliados a altura de plantas, diâmetro de colmos, número de perfilhos, produtividade (matéria fresca e seca, eficiência do teor de P na planta, extração de P e viabilidade econômica, na escolha da fonte e ºBrix. A adubação fosfatada influenciou o número e altura de plantas, concentração de P na planta, produtividade de matéria fresca e seca. Quanto às fontes estudadas, houve semelhança nos resultados encontrados, mas com maior eficiência para a farinha de ossos, que promoveu maior acúmulo de P na planta e maior extração pela cultura, e apresentou maior viabilidade econômica. A variedade IAC 86 2480 apresentou médias superiores às da SP 79 1011, em todos os parâmetros avaliados.

font-style: normal; font-weight: normal; line-height: 120%; text-decoration: none;" lang="pt-BR" align="JUSTIFY">font

Produtividade e Qualidade de Frutos de Melancia em Função de Alterações na Relação Fonte-Dreno

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Hamurábi Anízio Lins

2013-10-01

Full Text Available As hortaliças de frutos são cultivadas em todas as regiões do Brasil, e no nordeste, em que as condições de solo e clima favorecem o crescimento e desenvolvimento das plantas e dos frutos, o cultivo de plantas da família das Cucurbitáceas tem se destacado proporcionando a obtenção de plantas com alta produtividade e qualidade dos frutos colhidos. A melancieira é uma planta que permite várias formas de manipulação da relação entre a fonte e o dreno. Estas alterações na fonte e no dreno exercem influência na produtividade e qualidade dos frutos na colheita. O objetivo deste trabalho foi avaliar a produtividade e qualidade de frutos de melancieira em função de alterações na relação entre fonte e o dreno. No experimento os tratamentos constaram da condução da poda da haste dominante em diferentes épocas de cultivo (25, 30, 35 e 40 dias após o transplante - DAT e do número de frutos por planta (1 e 2. O experimento foi instalado no DBC em parcelas subdivididas com quatro repetições. As modificações induzidas na planta de melancieira por meio de podas e raleio de frutos proporcionaram alterações na relação fonte e dreno sendo benéfica para as características de produtividade e qualidade dos frutos. A poda da haste principal aos 35 DAT elevou a massa dos frutos e produtividade independente do número de frutos na planta. Plantas conduzidas com dois frutos proporcionaram redução na massa do fruto e dos sólidos solúveis e elevação na produtividade da cultura.

Crescimento de mudas de Gonçalo-Alves (Astronium fraxinifolium sob diferentes fontes e doses de nitrogênio

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Diego Gonçalves Feitosa

2011-06-01

Full Text Available A degradação do cerrado e a perda de sua biodiversidade demandam a revegetação de áreas desse bioma, onde existem espécies com potencial de uso econômico e ambiental pouco conhecidos. Este trabalho teve o objetivo de avaliar o efeito de diferentes fontes e doses de nitrogênio sobre o crescimento de mudas de Gonçalo-Alves (Astronium fraxinifolium, espécie arbórea nativa do cerrado ameaçada de extinção. O experimento foi realizado em estufa na UNESP/Campus de Ilha Solteira. O solo utilizado (Latossolo Vermelho foi coletado na profundidade de 0,0 a 0,20 m, em Selvíria (MS. As fontes de nitrogênio utilizadas ((NH42SO4, NH4NO3 e Ca(NO32 foram aplicadas nas doses de 0; 50; 100; 150 e 200 mg dm-3. O N aplicado na forma de Ca(NO32 apresentou melhor resultado para o solo utilizado. O crescimento das mudas de Gonçalo-Alves não foi influenciado pelas diferentes fontes de N, mas respondeu às doses. A altura da planta, o diâmetro do coleto, o teor de clorofila foliar, o peso da matéria fresca e seca da parte aérea e do sistema radicular, o peso seco total, bem como o IQD e a razão entre o peso da matéria seca da parte aérea e do sistema radicular, apresentaram valor máximo para doses que variaram de 59,0 a 72,5 mg dm-3 de N, permitindo sugerir a dose de 72,5 mg dm-3 de N como suficiente para o crescimento satisfatório de mudas de Gonçalo-Alves.

Mineralogia e fontes de potássio em solos no Rio Grande do Sul cultivados com arroz irrigado

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R. M. Castilhos

2002-09-01

Full Text Available Estudos desenvolvidos com arroz irrigado por inundação no estado do Rio Grande do Sul têm evidenciado ausência de resposta desta cultura à adubação potássica, mesmo em solos com baixo teor de potássio disponível. Este trabalho objetivou verificar a contribuição da mineralogia destes solos como fonte potencial de potássio para a cultura do arroz. Para tal, selecionaram-se quatro solos representativos das zonas orizícolas do estado do Rio Grande do Sul (Planossolo Hidromórfico, Planossolo Háplico, Gleissolo Háplico e Chernossolo Ebânico cultivados com arroz irrigado. Estes solos apresentam baixos teores de potássio trocável e não apresentam respostas à adubação potássica. Nas amostras dos horizontes A e B dos quatro solos, foram analisadas a granulometria e a composição química. A mineralogia das frações areia, silte e argila foi identificada por difratometria de raios-X. Os principais minerais fontes de potássio foram os seguintes: na fração areia, feldspatos e micas; nas frações silte e argila, feldspatos, micas, esmectitas e esmectitas com hidróxi-alumínio entrecamadas. A quantidade de potássio total, nas frações granulométricas, diferiu entre os solos. As frações silte e argila apresentaram os maiores teores de K-total, exceto para o Planossolo Háplico, que revelou maior reserva de potássio na fração areia. A ausência, ou a baixa resposta, à adubação potássica na cultura do arroz irrigado nesses quatro solos pode ser explicada pelos minerais fontes de potássio que ocorrem nesses solos.

Águas minerais de algumas fontes naturais brasileiras Mineral waters from brazilian natural sources

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M. A. P. Rebelo

1999-07-01

Full Text Available Paciente de litíase renal é estimulado a aumentar a ingestão hídrica, principalmente na forma de água tratada da torneira, pela irrelevante biodisponibilidade de minerais em sua composição. O benefício é atribuído à redução da saturação dos sais urinários. Não está claro se as águas minerais naturais comercialmente disponíveis também é benéfica. OBJETIVO. Divulgar as informações sobre as características químicas e físico-químicas de águas minerais naturais de algumas das diversas fontes brasileiras. Essas informações serão de utilidade na análise de protocolos de pesquisa e na orientação do paciente. MÉTODOS. Foi feito uma coletânea das informações que constam nos rótulos de garrafas de águas minerais naturais, predominantemente não-gasosas, acessíveis ao consumo carioca. A partir da composição salina provável, foi calculada a concentração iônica de cada mineral. RESULTADOS. Foram estudadas as informações de 36 fontes situadas em alguns estados brasileiros. O pH, a 25oC, variou de 4,1 a 9,3 na dependência da fonte e foi linearmente correlacionado com as concentrações dos cátions cálcio, magnésio, sódio e do anion bicarbonato. Isto foi atribuído à alta alcalinidade desses sais, que contêm cerca de 70% de bicarbonato na molécula. Os teores de cálcio (0,3 a 42 mg/l, de magnésio (0,0 a 18 mg/l e de bicarbonato (4 a 228 mg/l foram considerados relativamente baixos. CONCLUSÃO. O teor mineral das fontes brasileiras que compuseram esse levantamento é baixo, com cerca de 70% delas apresentando teores de cálcio e de magnésio abaixo de 10 mg/l e 1 mg/l, respectivamente, semelhantes ao da água tratada da torneira.PURPOSE. To divulge information on the chemical composition and physical-chemical features of some mineral waters from Brazilian natural sources that will be of useful protocol in vestigation and patient advice. METHODS. The survey was based on bottle labels of non

ENERGIA EÓLICA: uma fonte energética limpa e renovável em nosso meio

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GABRIEL MOREIRA

2011-07-01

Full Text Available Segundo o IBGE, no ano de 2010, a população brasileira teve um crescimento de 1,12%. Tendo em vista que tal crescimento necessita de uma grande demanda energética, precisa-se de fontes alternativas. Um bom meio supressor é a energia eólica. Meio de energia renovável e limpa. Segundo o documentário, Energia Eólica: a caçada pelos ventos, exibido pela TV Zabelê: “É uma dádiva da natureza o fato da nossa região ter esse grande potencial eólico [...].” No entanto, sua instalação necessita-se de grandes investimentos. Tendo em vista este grande crescimento populacional o projeto de pesquisa Energia Eólica: Uma fonte energética limpa e renovável em nosso meio, tem como objetivo a produção de um pequeno campo de energia eólica, em uma biblioteca na escola Oswaldo Cruz, na cidade de Sinop, Mato Grosso. Desta forma temos a possibilidade de reduzir 70% do consumo energético convencional, proporcionando uma economia financeira considerável. A implantação deste projeto está prevista para o segundo semestre de 2014.

O tesouro de conhecimentos de um bairro chamado maré: pessoas como fontes de informaçãoKnowlegde treasure in maré neighborhood: people as information sources

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Isa Maria Freire

2007-01-01

Full Text Available Apresenta o resultado de pesquisa, em nível exploratório, abordando as pessoas, cidadãos comuns, como fontes de informação para uma dada comunidade, na perspectiva da responsabilidade social do profissional bibliotecário. Discorre sobre o campo da pesquisa, o bairro Maré e suas comunidades. Utiliza a metodologia da pesquisa-ação para criar uma equipe de pesquisa e investigar a existência dessas pessoas e sua atuação como fontes de informação na comunidade. Procura dar visibilidade ao “invisível”, identificando onde e como funcionam a busca, recuperação e uso da informação nas pessoas detentoras de conhecimento, em uma dada comunidade. Utiliza a técnica de entrevista estruturada para o registro do conhecimento de uma dessas fontes, seus ofícios e talentos, revelando como adquiriu esse conhecimento e se o transmite para outras pessoas. Apresenta um formato para um sítio virtual contendo o Tesouro de conhecimentos de Comunidades da Maré.This work is a presentation of research results in an exploratory level as a graduation monograph. The aim of the work was to approach people common citizens as information fonts related to determined community in the perspective of the social responsibility of the librarian professional. The research environment dealt was the Maré neighborhood and its communities. The methodology used was research-action in order to create a research staff to investigate theexistence of these people and their actions as information fonts in the community. The work also aimed to make the “invisible” more visible, identifying where and how search, recall ad information use is done through people that gather knowledge in a referred community. Thus a structures interview technique was used to register the information fonts´ knowledge, their occupations and talents; making the revelation of how the knowledge was acquired as well as its transmission to other people. The interview was Transcripted and

Intertextos: sobre les fonts i els motius literaris de Lo desengany de Fontanella

OpenAIRE

Rossich i Estragó, Albert

2012-01-01

En aquest article s’estudien les fonts i els préstecs literaris que es poden detectar en «Lo Desengany», una notable peça dramàtica en dos actes escrita per Francesc Fontanella cap al 1650. Bon coneixedor de la literatura clàssica i de les iteratures més importants del seu temps (la castellana, la francesa i la italiana), Fontanella reflecteix en aquesta obra les seves lectures, i concretament les dels «Idil·lis» de Teòcrit, les «Metamorfosis» d’Ovidi, la «Farsàlia» de Lucà, «La Araucana» d’A...

Fuzzy-Based Segmentation for Variable Font-Sized Text Extraction from Images/Videos

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Samabia Tehsin

2014-01-01

Full Text Available Textual information embedded in multimedia can provide a vital tool for indexing and retrieval. A lot of work is done in the field of text localization and detection because of its very fundamental importance. One of the biggest challenges of text detection is to deal with variation in font sizes and image resolution. This problem gets elevated due to the undersegmentation or oversegmentation of the regions in an image. The paper addresses this problem by proposing a solution using novel fuzzy-based method. This paper advocates postprocessing segmentation method that can solve the problem of variation in text sizes and image resolution. The methodology is tested on ICDAR 2011 Robust Reading Challenge dataset which amply proves the strength of the recommended method.

Método "fingerprinting" para identificação de fontes de sedimentos em bacia hidrográfica rural Fingerprinting method for identification of sediment sources in a rural watershed

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Jean P. G. Minella

2009-10-01

Full Text Available Este trabalho se refere a um estudo de identificação de fontes de sedimentos, realizado em uma bacia rural localizada em uma região montanhosa, no sul do Brasil. A bacia representa um ecossistema típico de exploração agrícola, realizado por pequenos agricultores que cultivam fumo em áreas marginais, com conseqüências severas aos recursos naturais. A identificação das fontes de sedimentos, baseada na análise dos sedimentos transportados em suspensão, possibilita avaliar as áreas que contribuem para a sua produção e fazer inferências sobre o potencial poluidor desses sedimentos. A metodologia utilizada foi a técnica "fingerprinting", através da qual foram exploradas as principais limitações da metodologia e as potencialidades na identificação das fontes de sedimentos. A classificação possibilitou a identificação da contribuição relativa das fontes, considerando-se preponderantes as lavouras e as estradas. Os resultados mostraram que a contribuição das duas fontes foi variável no tempo e a proporção relativa da contribuição de cada fonte variou de acordo com o manejo e a cobertura do solo que ocorreu nas lavouras e das obras de manutenção realizadas nas estradas. A contribuição das fontes mostrou que as lavouras e as estradas contribuíram com 64 e 36%, respectivamente.In this study, the fingerprinting method was used to identify sediment sources in a small rural watershed located in a mountainous region in southern Brazil. This watershed represents a typical agricultural ecosystem, in which smallhold farmers cultivate tobacco in marginal areas, with severe consequences to the natural resources. The identification of sediment sources, based on analysis of sediments transported in suspension, enables an evaluation of which areas are truly contributing to sediment production and, therefore, to make inferences about the polluting potential of these sediments. The study considered the main limitations of this

A High-Frequency Isolation (HFI Charging DC Port Combining a Front-End Three-Level Converter with a Back-End LLC Resonant Converter

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Guowei Cai

2017-09-01

Full Text Available The high-frequency isolation (HFI charging DC port can serve as the interface between unipolar/bipolar DC buses and electric vehicles (EVs through the two-power-stage system structure that combines the front-end three-level converter with the back-end logical link control (LLC resonant converter. The DC output voltage can be maintained within the desired voltage range by the front-end converter. The electrical isolation can be realized by the back-end LLC converter, which has the bus converter function. According to the three-level topology, the low-voltage rating power devices can be adapted for half-voltage stress of the total DC grid, and the PWM phase-shift control can double the equivalent switching frequency to greatly reduce the filter volume. LLC resonant converters have advance characteristics of inverter-side zero-voltage-switching (ZVS and rectifier-side zero-current switching (ZCS. In particular, it can achieve better performance under quasi-resonant frequency mode. Additionally, the magnetizing current can be modified following different DC output voltages, which have the self-adaptation ZVS condition for decreasing the circulating current. Here, the principles of the proposed topology are analyzed in detail, and the design conditions of the three-level output filter and high-frequency isolation transformer are explored. Finally, a 20 kW prototype with the 760 V input and 200–500 V output are designed and tested. The experimental results are demonstrated to verify the validity and performance of this charging DC port system structure.

Novas citações de Chytridiomycota e Oomycota para o Parque Estadual das Fontes do Ipiranga (PEFI), SP, Brasil New records of Chytridiomycota and Oomycota from the "Parque Estadual das Fontes do Ipiranga (PEFI)", SP, Brazil

OpenAIRE

Carmen Lidia Amorim Pires-Zottarelli; Maristela Rocha

2007-01-01

Levantamento de fungos zoospóricos realizado em lagos artificiais do Parque Estadual das Fontes do Ipiranga (PEFI), situado na cidade de São Paulo, Estado de São Paulo, Brasil, resultou no isolamento de 41 táxons, sendo 36 identificados em nível específico. Vinte e três táxons pertencem ao Reino Fungi, filo Chytridiomycota, ordens Chytridiales, Monoblepharidales e Spizellomicetales e, 18 ao Reino Straminipila, filo Oomycota, ordens Saprolegniales e Peronosporales. Dentre os fungos isolados, 1...

Solubilização de fostatos por microrganismos na presença de fontes de carbono

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G. N. Silva Filho

2000-06-01

Full Text Available O potencial de solubilização de fosfatos por bactérias e fungos cultivados em meio de cultura GEL (Glicose-Extrato de Levedura, suplementado com diferentes formas de fosfatos (cálcio, alumínio e ferro e fontes de carbono (celulose, amido, sacarose, glicose, frutose e xilose, foi avaliado em laboratório. O crescimento, o diâmetro da área solubilizada e a relação halo/colônia variaram conforme o tipo de microrganismo e a fonte de fósforo e de carbono. Dos 57 isolados utilizados, 56 formaram halo na presença de fosfato de cálcio e cinco apenas na presença de fosfato de alumínio e nenhum foi capaz de solubilizar fosfato de ferro. Contudo, seis isolados cresceram melhor no meio com fosfato de ferro em comparação com o meio testemunha. As maiores colônias e halos foram observados nos isolados de Rhizopus e Aspergillus, enquanto as maiores relações halo/colônia foram encontradas em Paecilomyces e Penicillium. Todos os isolados cresceram no meio GEL base (testemunha sem açúcar, mas a solubilização ocorreu apenas na presença de carbono adicionado ao meio, destacando-se xilose, glicose, frutose e sacarose.

Cativeiro de aves como fonte de Cryptococcus neoformans na cidade de Campo Grande, Mato Grosso do Sul, Brasil

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Filiú Wander Fernando de Oliveira

2002-01-01

Full Text Available Cryptococcus neoformans é a levedura capsulada causadora de criptococose em humanos e animais. A variedade neoformans, encontrada em diversas fontes ambientais, inclusive habitats de aves, é importante causa de mortalidade em indivíduos com AIDS em todo o Mundo. Contudo, ainda não há estudos sobre a sua ecologia na região Centro Oeste brasileira, onde há registro da ocorrência de casos humanos da micose. Para estudar fontes saprofíticas de C. neoformans, na cidade de Campo Grande, foram coletadas 20 amostras de excretas de aves em distintos ambientes. Suspensão das amostras em salina estéril foram semeadas em placas com meio ágar níger. Após 5 dias, colônias mucóides marrom-escuro foram subcultivadas para identificação através de provas morfofisiológicas, determinação da variedade e sorotipagem. C. neoformans var. neoformans sorotipo A foi isolado de 10 (50% das amostras, comprovando a ocorrência saprofítica de C. neoformans na cidade de Campo Grande, relacionada a habitat de aves em cativeiro.

Representações sociais, conhecimento científico e fontes de informação sobre aids

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Jean Carlos Natividade

2011-08-01

Full Text Available Investigaram-se, neste estudo, as relações entre a valorização simbólica atribuída a onze elementos descritores da representação social da aids, o nível de conhecimento científico sobre o HIV e aids, e as fontes de obtenção de informações sobre aids. Utilizou-se um questionário autoaplicável, de respostas fechadas, em 150 estudantes do ensino médio de uma escola pública. Identificaram-se relações significativas entre os elementos, que apontaram três fatores como caracterizadores da representação social da aids: responsabilidade diante do contágio; medo das consequências do contágio; descrição da aids. Foram encontradas relações significativas entre a valorização simbólica de seis elementos e quatro fontes de informação, que corroboraram a importância da comunicação extragrupo na constituição das representações sociais. Contudo, entre a valorização simbólica dos elementos e os níveis de conhecimento científico as relações não se mostraram significativas.

Uso de diferentes fontes de nitrogênio na cultura da soja

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Evelin Cristina Marcon

2017-05-01

Full Text Available O nitrogênio é um nutriente requerido em quantidade pela da soja, pois é responsável pelo crescimento da cultura e produção de novas células e tecidos. Com estudo teve-se por objetivo avaliar diferentes fontes de nitrogênio na soja e a sua influência sobre proteína bruta e rendimento de grãos. O experimento foi realizado durante o ciclo 2015/2016, na Fazenda Escola da Unoesc, São José do Cedro – SC. O delineamento experimental foi em blocos ao acaso (DBC, com 7 repetições. A unidade experimental constituiu-se de uma parcela. Os tratamentos compreenderam diferentes fontes de nitrogênio (sólido (Super N, líquido N 32 e a testemunha sem nitrogênio testadas na cultivar TMG 7062 IPRO. A aplicação de nitrogênio foi realizada em cobertura em duas etapas, metade da dose aplicada no estádio R1 (início do florescimento e a outra metade em R3 (formação da vagem, nas dosagens de 4 L ha-1 para o nitrogênio líquido 32% e 200 kg ha-1 de nitrogênio sólido 46%. Após a colheita, avaliou-se o teor de proteína bruta, o rendimento de grãos por área, a viabilidade econômica e a produtividade. Os dados foram submetidos à análise de variância pelo teste F e, quando significativos, foram submetidos à comparação de médias pelo teste de Tukey (P≤0,05. Para a cultura da soja a aplicação de nitrogênio líquido suplementar tem efeito positivo sobre o componente de rendimento da soja massa de mil grãos. A aplicação de nitrogênio sólido incrementou a produtividade de grãos. O uso de nitrogênio proporcionou maior rendimento econômico no ciclo 2015/2016 para a cultivar TMG 7062 IPRO em relação a testemunha.

METODOLOGIA DE IDENTIFICAÇÃO DE FONTE E COLETA DE INFORMAÇÃO: UMA PROPOSTA DE MODELO PARA CADEIA PRODUTIVA DO COURO, CALÇADOS E ARTEFATOS

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Alexander Willian Azevedo

2012-04-01

Full Text Available Este trabalho descreve a metodologia de análise de coleta de fontes de informação desenvolvida e implementada como ferramenta de apoio às atividades de inteligência do Sistema de Inteligência Competitiva da Cadeia Produtiva do Couro, Calçados e Artefatos (SIC. O objetivo do presente trabalho compreende em apresentar a descrição e os procedimentos para a aplicação de coletas das fontes de informação junto aos produtos de informações armazenados na ferramenta de apoio às atividades do SIC, visando à elaboração de um processo de busca de informação relevante dos atores globais da cadeia produtiva. Com base nas dinâmicas competitivas da Cadeia Produtiva do Couro, Calçados e Artefatos do Brasil, o principal resultado apresenta modelo de coleta de fontes de informação para um setor da cadeia produtiva, de acordo com as necessidades de inteligência identificadas que podem servir de base para as equipes de inteligência dos elos das cadeias produtivas do Brasil.

Energy optimal control strategies for electro motors; low-cost and sensorless PWM-VSI based induction motor control. Vol. 1: Main report, appendix and annex

Energy Technology Data Exchange (ETDEWEB)

Abrahamsen, F

1998-02-01

When variable speed induction motor drives are used in applications that run at low load for long periods, energy can be saved by reducing the motor flux at low load. In this report the efficiency of 2.2 kW standard and high-efficiency motor drives are investigated experimentally with efficiency optimized and constant flux control, with sinusoidal and PWM voltage supply and with varying switching frequency. Steady-state motor models are developed and verified experimentally, and are used to analyze and develop efficiency optimizing control strategies. Four energy optimal control strategies are tested experimentally: cos({phi}) control, model-based control, off-line calculated airgap flux control and stator current/input power minimising search control. Their dynamical properties and their ability to reject load disturbances are analysed. Their ability to save energy is tested on a water pump system. For a typical predefined test-cycle the energy optimal control reduces the energy consumption with 10% compared with classical constant V/Hz control. (au)

Ferramentas para mediação de fontes de informação: avaliação sobre seus usos em bibliotecas universitárias nacionais e internacionais

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Valéria Aparecida Moreira Novelli

Full Text Available A pesquisa relata o uso de ferramentas para mediação de fontes de informação por bibliotecas universitárias nacionais e internacionais. O estudo foi de caráter exploratório e utilizou análise de conteúdo, com abordagem quantitativa e qualitativa, de websites de 24 bibliotecas selecionadas dentre as melhores universidades internacionais e nacionais segundo indicadores da Webometrics Ranking of World's Universities, World University Rankings 2011-2012 e Índice Geral de Cursos. Objetivou-se investigar e identificar tendências de aplicações de ferramentas para as atividades de mediação dos processos de acesso, busca e aprendizagem do uso de fontes de informação em bibliotecas universitárias. Os resultados apontam um panorama geral de como as bibliotecas universitárias estão realizando o processo de mediação de fontes de informação, especialmente em relação às bases de dados bibliográficas. Observou-se variações na escala de implementação dessas ferramentas entre as bibliotecas internacionais e as bibliotecas nacionais, bem como o destaque de algumas delas. Conclui-se que diante da disponibilidade e acessibilidade cada vez mais crescente das fontes de informação, torna-se necessário que estas sejam utilizadas de forma eficaz e eficiente. Neste contexto cabe ao bibliotecário refletir, selecionar e implementar ações e ferramentas mais viáveis à realidade de cada biblioteca, considerando as características específicas das gerações e categorias de usuários, a diversidade de tecnologias ofertadas a estes usuários e também aos não usuários, autonomia, estímulo e facilidades para o acesso, busca e uso das fontes de informação.

Emissões veiculares em São Paulo: quantificação de fontes com modelos receptores e caracterização do material carbonáceo

OpenAIRE

Djacinto Aparecido Monteiro dos Santos Junior

2015-01-01

A significativa emissão veicular na Região Metropolitana de São Paulo (RMSP), com mais de 7 milhões de veículos e uma população da ordem de 18 milhões de habitantes, fazem desta uma área crítica do ponto de vista de níveis de poluentes atmosféricos. Neste trabalho foi obtida a determinação quantitativa de fontes de poluentes atmosféricos na RMSP, em particular do material carbonáceo na fração fina (PM2.5) do aerossol atmosférico, focando na componente veicular. Como parte do projeto FONTES, c...

Design and implementation of predictive current control of three-phase PWM rectifier using space-vector modulation (SVM)

International Nuclear Information System (INIS)

Bouafia, Abdelouahab; Gaubert, Jean-Paul; Krim, Fateh

2010-01-01

This paper is concerned with the design and implementation of current control of three-phase PWM rectifier based on predictive control strategy. The proposed predictive current control technique operates with constant switching frequency, using space-vector modulation (SVM). The main goal of the designed current control scheme is to maintain the dc-bus voltage at the required level and to achieve the unity power factor (UPF) operation of the converter. For this purpose, two predictive current control algorithms, in the sense of deadbeat control, are developed for direct controlling input current vector of the converter in the stationary α-β and rotating d-q reference frame, respectively. For both predictive current control algorithms, at the beginning of each switching period, the required rectifier average voltage vector allowing the cancellation of both tracking errors of current vector components at the end of the switching period, is computed and applied during a predefined switching period by means of SVM. The main advantages of the proposed predictive current control are that no need to use hysteresis comparators or PI controllers in current control loops, and constant switching frequency. Finally, the developed predictive current control algorithms were tested both in simulations and experimentally, and illustrative results are presented here. Results have proven excellent performance in steady and transient states, and verify the validity of the proposed predictive current control which is compared to other control strategies.

Isolated PWM DC-AC SICAM with an active capacitive voltage clamp[Pulse Density Modulated; Pulse Width Modulation

Energy Technology Data Exchange (ETDEWEB)

Ljusev, P.

2004-03-15

In this report an isolated PWM DC-AC SICAM with an active capacitive voltage clamp is presented. AC-DC power supply is implemented in its simplest form: diode rectifier followed by a medium-size charge-storage capacitors and possibly with an EMC filter on the mains entrance. Isolation from the AC mains is achieved using a high frequency (HF) transformer, whose voltages are not audio-modulated. The latter simplifies the design and is expected to have many advantages over the approach where the transformer voltages are modulated in regards to the audio signal reference. Input stage is built as a DC-AC inverter (push-pull, half-bridge or a full-bridge) and operated with 50% duty cycle, with all the challenges to avoid transformer saturation and obtain symmetrical operation. On the secondary side the output section is implemented as rectifier+inverter AC-AC stage, i.e. a true bidirectional bridge, which operation is aimed towards amplification of the audio signal. In order to solve the problem with the commutation of the load current, a dead time between the incoming and outgoing bidirectional switch is implemented, while a capacitive voltage clamp is used to keep the induced overvoltage to reasonable levels. The energy stored in the clamping capacitor is not wasted as in the dissipative clamps, but is rather transferred back to the primary side for further processing using an auxiliary isolated single-switch converter, i.e. an active clamping technique is used. (au)

Analise da influencia das fontes de carbono na patogenicidade do Moniliophthora perniciosa pathogenicity em Theobroma cacao

OpenAIRE

Fatima Cerqueira Alvim

2009-01-01

Resumo: O fungo basidiomiceto hemibiotrófico Moniliophthora perniciosa, agente causal da doença vassoura-de-bruxa (VB) em Theobroma cacao, é o principal patógeno da lavoura cacaueira nas Américas e no Caribe. O presente trabalho apresentou como objetivo primordial identificar proteínas relacionadas com a patogenicidade deste fungo. No primeiro capítulo desta tese foi demonstrado o efeito de diferentes fontes de carbono sobre a morfologia e fisiologia do M, perniciosa. O fungo foi crescido em ...

Auditorias internas como fonte de informa??o para o conhecimento organizacional: estudo de caso em uma IFES

OpenAIRE

Santos, Ludinaura Regina Souza dos

2012-01-01

O objetivo geral desta pesquisa foi o de analisar como os processos de auditoria interna v?m se transformando em fonte de informa??o para o conhecimento organizacional em uma IFES. O marco te?rico foi estruturado em quatro partes: (1) discuss?o sobre conhecimento organizacional, (2) teoria da cria??o do conhecimento organizacional, (3) o controle da administra??o p?blica no Brasil e (4) auditorias internas governamentais. Quanto ? caracteriza??o da pesquisa, apresentou um aspec...

Comparative study of the action of two different types of bleaching agents activated by two different types of irradiation fonts: xenon plasma arc lamp and 960 nm diode laser

International Nuclear Information System (INIS)

Walverde, Debora Ayala

2001-01-01

This in vitro study compares two different types of tooth bleaching agents stimulated with two different irradiation fonts. These fonts accelerate the action of the bleaching agents upon the enamel surface by heating up the materials. We used the xenon plasma arc lamp and a 960 nm fiber-coupled diode laser to irradiate the two materials containing 35% of hydrogen peroxide (Opus White and Opalescence extra). The color of the teeth was measured with a spectrophotometer using the CIELAB color system that gives the numeric values of L * a * b * . (author)

Design of an Internal Model Control strategy for single-phase grid-connected PWM inverters and its performance analysis with a non-linear local load and weak grid.

Science.gov (United States)

Chaves, Eric N; Coelho, Ernane A A; Carvalho, Henrique T M; Freitas, Luiz C G; Júnior, João B V; Freitas, Luiz C

2016-09-01

This paper presents the design of a controller based on Internal Model Control (IMC) applied to a grid-connected single-phase PWM inverter. The mathematical modeling of the inverter and the LCL output filter, used to project the 1-DOF IMC controller, is presented and the decoupling of grid voltage by a Feedforward strategy is analyzed. A Proportional - Resonant Controller (P+Res) was used for the control of the same plant in the running of experimental results, thus moving towards the discussion of differences regarding IMC and P+Res performances, which arrived at the evaluation of the proposed control strategy. The results are presented for typical conditions, for weak-grid and for non-linear local load, in order to verify the behavior of the controller against such situations. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Compósitos a partir de materiais de fontes renováveis como alternativa para o desenvolvimento de produtos

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Eliana Paula Calegari

2016-04-01

Full Text Available A preocupação ambiental tem gerado interesse na pesquisa de novos materiais que estejam alinhados com os princípios da sustentabilidade. Entre esses materiais, atualmente, encontram-se os compósitos produzidos a partir de recursos de fontes renováveis. Este artigo apresenta os resultados de um estudo de caso acerca de produtos em que são empregados os referidos compósitos. Realizou-se uma pesquisa na rede mundial de computadores usando a ferramenta de buscas google sobre produtos fabricados com esses compósitos e comparou-se com produtos fabricados a partir de materiais usualmente utilizados na indústria, tais como polímeros, metais e cerâmicas. Constatou-se que os compósitos feitos a partir de fontes renováveis estão sendo, principalmente, aplicados em embalagens, na produção de ferramentas para jardinagem e vasos para plantas. Dessa forma, observou-se que os referidos compósitos podem substituir materiais comumente empregados na indústria atendendo aos requisitos funcionais e estéticos demandados na confecção desses produtos.

Font size matters--emotion and attention in cortical responses to written words.

Science.gov (United States)

Bayer, Mareike; Sommer, Werner; Schacht, Annekathrin

2012-01-01

For emotional pictures with fear-, disgust-, or sex-related contents, stimulus size has been shown to increase emotion effects in attention-related event-related potentials (ERPs), presumably reflecting the enhanced biological impact of larger emotion-inducing pictures. If this is true, size should not enhance emotion effects for written words with symbolic and acquired meaning. Here, we investigated ERP effects of font size for emotional and neutral words. While P1 and N1 amplitudes were not affected by emotion, the early posterior negativity started earlier and lasted longer for large relative to small words. These results suggest that emotion-driven facilitation of attention is not necessarily based on biological relevance, but might generalize to stimuli with arbitrary perceptual features. This finding points to the high relevance of written language in today's society as an important source of emotional meaning.

APLIKASI GENERATOR AKORD DENGAN MENGGUNAKAN FONT NOTANGKA.TTF DAN MENGADAPTASI LOGIKA DIRECT PRODUCT PADA NOTASI MUSIKAL ANGKA

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Eko Sediyono

2009-01-01

Full Text Available Information technology has brought a big influence in other fields of science, especially in music. One part of the musical arrangement process is chord defining. Direct product is one of vector multiplication types. Although its using in vector, but in music, it can be used for searching all possibilities of chord arrangement. This chord generator will use NotAngka2.ttf as a basic for input writing. Because of the unexistence of application for writing song in number notation with NotAngka2 font type and generating some chord arrangements for the song, so this topic become a focus for application designing and implementing. Abstract in Bahasa Indonesia: Paper ini membahas perancangan aplikasi pembangkit akord dari not angka yang ditulis dengan editor teks dengan font NotAngka2.ttf. Langkah-langkah yang digunakan untuk membangkitkan akord menggunakan teknik kompilasi. Tahap pertama adalah lexical analysis yang menyaring string dan membentuk token. Tahap ke dua adalah syntax analysis dimana input yang masuk diteliti struktur gramarnya. Selanjutnya dengan menggunakan logika perkalian langsung (direct product logic, maka dapat dibentuk akord yang sesuai dengan lagu masukannya. Aplikasi yang dibangun masih dalam tahap awal, sehingga inputnya masih terbatas pada lagu yang sangat sederhana, yang dibatasi pada patokan nada dasar, ketukan, jenis akord, serta tangga nada yang digunakan Kata kunci: akord, direct product, syntax analysis, lexical analysis

CARMELITA PINTO FONTES E O GINÁSIO DE APLICAÇÃO DA FACULDADE CATÓLICA DE FILOSOFIA DE SERGIPE (1961-1967

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Ane Rose de Jesus Santos Maciel

2016-03-01

Full Text Available Este artigo evidencia as ações pedagógicas da professora Carmelita Pinto Fontes no Ginásio de Aplicação da Faculdade Católica de Filosofia de Sergipe, entre os anos de 1961 a 1967. Esses estabelecimentos foram construídos como espaço de estágio para alunos concludentes dos cursos de Didática das Faculdades de Filosofia no Brasil, no entanto, tornaram-se um dos principais meios de divulgação de novas metodologias educacionais. Metodologicamente ancorado na pesquisa qualitativa, com apoio da História Cultural, da Educação e de Sergipe, além da História Oral, buscamos preencher lacunas deixadas pela historiografia da educação acerca de uma personagem importante para a configuração educacional que, através da educação, construiu sua trajetória intelectual em uma sociedade marcadamente masculina. Palavras-chave: Didática; Educação; Ginásio de Aplicação.   CARMELITA PINTO FONTES AND THE GYMNASIUM OF APPLICATION FROM THE CATHOLIC COLLEGE OF PHILOSOPHY OF SERGIPE (1961-1967 ABSTRACT This paper evidences the pedagogical actions from the professor Carmelita Pinto Fontes in the Gymnasium of Application from the Catholic College of Philosophy of Sergipe, through 1961 to 1967. These stablishment were built as a space of internship to senior students of the Didatic major from the Catholic College of Philosophy of Sergipe in Brazil; however, they became one of the main means for disseminating new educational technology. Methodologically anchored in qualitative research, with support of the Cultural History, Education and Sergipe, beyond of the Oral History, we seek to fill left gaps for the historiography of education about an important caracther to the educational configuration that built through education, her intellectual trajectory in a markedly male society. Keywords: Didatic; Education; Gymnasium of Application.   CARMELITA PINTO FONTES E O GIMNASIO DE APLICACIÓN DE LA FACULTAD CATÓLICA DE FILOSOFIA DE SERGIPE

Cytokine and immunoglobulin production by PWM-stimulated peripheral and tumor-infiltrating lymphocytes of undifferentiated nasopharyngeal carcinoma (NPC patients

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Bouzouita Kamel

2004-09-01

Full Text Available Abstract Background Undifferentiated Nasopharyngeal Carcinoma (NPC patients show a characteristic pattern of antibody responses to the Epstein-Barr virus (EBV which is regularly associated with this tumor. However, no EBV-specific cytotoxic activity is detectable by the standard chromium-release assay at both peripheral and intratumoral levels. The mechanisms underlying this discrepancy between the humoral and cellular immune responses in NPC are still unknown, but might be related to an imbalance in immunoregulatory interleukin production. In this report, we investigated the ability of peripheral (PBL and tumor- infiltrating (TIL lymphocytes of undifferentiated NPC patients to produce in vitro three interleukins (IL-2, IL-6, IL-10 and three immunoglobulin isotypes (IgM, IgG, IgA. Methods Lymphocytes from 17 patients and 17 controls were cultured in the presence of Pokeweed mitogen (PWM for 12 days and their culture supernatants were tested for interleukins and immunoglobulins by specific enzyme-linked immunosorbent assays (ELISA. Data were analysed using Student's t-test and probability values below 5% were considered significant. Results The data obtained indicated that TIL of NPC patients produced significantly more IL-2 (p = 0,0002, IL-10 (p = 0,020, IgM (p= 0,0003 and IgG (p Conclusion Taken together, our data reinforce the possibility of an imbalance in immunoregulatory interleukin production in NPC patients. An increased ability to produce cytokines such as IL-10 may underlie the discrepancy between humoral and cellular immune responses characteristic of NPC.

Modelagem conceitual para identificação de áreas com potencial para geração de energia por fonte renovável

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Vivian Celestino

2016-12-01

Full Text Available O mundo enfrenta um desafio na busca de alternativas para atender a demanda de energia elétrica de forma sustentável e diminuir os efeitos dos Gases de Efeito Estufa. Uma maneira de minimizar estes efeitos e expandir o parque gerador é incrementar a produção com recurso a fontes renováveis. Mas para que, no momento de instalar um novo empreendimento, seja tomada uma decisão assertiva é necessário realizar a compilação de variáveis que sejam pertinentes ao tema e ao espaço geográfico. O objetivo deste artigo é apresentar uma modelagem conceitual por objetos (de acordo com o padrão OMT-G de forma a identificar áreas potenciais para gerar energia elétrica por fontes renováveis.

Extração de compostos bioativos de fontes vegetais utilizando solventes eutécticos

OpenAIRE

Almeida, Fátima Daniela Ferreira

2016-01-01

Na última década, tem-se intensificado o estudo da utilização de líquidos iónicos e solventes eutécticos em diversos processos de separação e reação, podendo constituir em muitas aplicações, uma alternativa mais favorável aos solventes orgânicos voláteis. Neste trabalho, pretende-se estudar a aplicação de alguns destes solventes na extração de compostos fenólicos existentes em verduras. Como planta modelo, escolheu-se a espécie Asparagus acutifolius L., uma planta comestível, fonte de comp...

FONTES PROTÉICAS DE ORIGEM VEGETAL EM DIETAS PARA JUVENIS DE CARPA HÚNGARA (Cyprinus carpio)

OpenAIRE

Giovani Taffarel Bergamin

2009-01-01

O objetivo deste trabalho foi avaliar a resposta de diferentes fontes protéicas de origem vegetal em substituição à farinha de carne suína da dieta, sobre o crescimento, rendimento e qualidade de carcaça, parâmetros sangüíneos e avaliação sensorial dos filés de juvenis de carpa húngara. Foram realizados dois experimentos, utilizando sistema de recirculação de água com 15 unidades experimentais (280L). No experimento 1, foram avaliadas cinco dietas experimentais. Uma dieta controle (FCS) co...

A ética de lado a lado: Fontes de notícias e jornalistas frente a frente

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Francisco José Karam

2010-12-01

Full Text Available O artigo confronta a ética das fontes de notícias com a deontologia dos jornalistas. Os protagonistas são colocados frente a frente para apurar as responsabilidades, os conflitos, direitos, equívocos e, inclusive, as promiscuidades. Além do diálogo entre autores, confere-se nos manuais de redação e ética dos principais jornais brasileiros - Folha de S. Paulo, O Estado de S. Paulo, O Globo e Zero Hora - como tratam essa relação.

Fontes Clássicas acerca do ceticismo de Arcesilaos de Pitanê Parte I: Agostinho de Hipona

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Roberto zarco

2014-07-01

Full Text Available Primeiro de uma série de artigos que pretende fazer um crítico e filosófico levantamento das fontes Clássicas acerca das filosofia e atividade filosófica de Arcesilaos de Pitanê, propõe demonstrar a inviabilidade de utilizar-se de Agostinho de Hipona, e sua obra Contra Academicus, no executar deste intuito. Para tanto, intenciona-se apresentar Contra Academicus enquanto livro inserido num contexto anti-estóico e cristão, típicos de um autor patrístico como Agostinho de Hipona.

Comparative growth of trichoderma strains in different nutritional sources, using bioscreen c automated system Crescimento de linhagens de Trichoderma em diferentes fontes nutricionais, empregando o sistema automatizado Bioscreen C.

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Bianca Caroline Rossi-Rodrigues

2009-06-01

Full Text Available Trichoderma is one of the fungi genera that produce important metabolites for industry. The growth of these organisms is a consequence of the nutritional sources used as also of the physical conditions employed to cultivate them. In this work, the automated Bioscreen C system was used to evaluate the influence of different nutritional sources on the growth of Trichoderma strains (T. hamatum, T. harzianum, T. viride, and T. longibrachiatum isolated from the soil in the Juréia-Itatins Ecological Station (JIES, São Paulo State - Brazil.The cultures were grown in liquid culture media containing different carbon- (2%; w/v and nitrogen (1%; w/v sources at 28ºC, pH 6.5, and agitated at 150 rpm for 72 h. The results showed, as expected, that glucose is superior to sucrose as a growth-stimulating carbon source in the Trichoderma strains studied, while yeast extract and tryptone were good growth-stimulating nitrogen sources in the cultivation of T. hamatum and T. harzianum.Trichoderma é um dos gêneros de fungos produtores de metabólitos de interesse industrial. O crescimento destes organismos é conseqüência das fontes nutricionais utilizadas, juntamente com as condições físicas de cultivo. Neste trabalho, o sistema automatizado Bioscreen C foi utilizado para avaliar a influência de diferentes fontes nutricionais sobre o crescimento de linhagens de Trichoderma (T. hamatum, T. harzianum, T. viride e T. longibrachiatum isoladas do solo da Estação Ecológica da Juréia-Itatins (JIES, São Paulo - Brasil. Os cultivos foram feitos em meios líquidos de cultura contendo diferentes fontes de carbono (2%; w / v e nitrogênio (1%; w / v a 28ºC, pH 6,5 e agitados a 150 rpm durante 72 h. Os resultados mostraram, conforme esperado, que a glicose é melhor do que a sacarose como fonte de carbono indutora de crescimento das linhagens de Trichoderma testadas, enquanto que, o extrato de leveduras e a triptona foram boas fontes de nitrogênio indutoras de

Contribuição ao estudo das fontes arteriais do encéfalo: arterjografia toracocervical mediante hiperpressão pulmonar

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Oswaldo Ricciardi-Cruz

1963-12-01

Full Text Available Êste trabalho versa sôbre a visibilização das fontes arteriais do encéfalo mediante injeção de substância radiopaca por via carotídea, graças ao bloqueio circulatório resultante do aumento da pressão intrapulmonar. São consideradas fontes arteriais encefálicas as carótidas comuns, as artérias vertebrais, o tronco braquiocefálico e os segmentos pré-vertebrais das artérias subclávias. A punção arterial, transcutânea, é feita em uma das carótidas comuns ou, excepcionalmente, no tronco braquiocefálico ou na artéria subclávia (segmento pré-vertebral. Para aumentar a pressão intrapulmonar, o pulmão do paciente é insuflado com oxigênio através da sonda traqueal munida de "cuff". Uma válvula, colocada entre a fonte de oxigênio e a sonda traqueal, permite controlar a pressão intrapulmonar, que não deve exceder a 75 mm Hg. A injeção de substância contrastante é feita em 2 a 3 segundos e deve ser iniciada assim que a pressão intrapulmonar atinge o valor de 75 mm Hg, prèviamente fixado na válvula. A compressão digital da carótida a jusante do ponto de inserção da agulha tem sido recurso complementar eficiente, proporcionando visibilização de tôdas as artérias da região de modo nítido e constante. São expostos os resultados de 46 exames realizados segundo a técnica descrita. Nenhum caso de acidente foi registrado. Embora haja ainda alguns pontos obscuros e pormenores de técnica que devem ser aperfeiçoados ou modificados, a simplicidade e a segurança do método permitem situá-lo em posição vantajosa entre seus congêneres.

Sadhana | Indian Academy of Sciences

Indian Academy of Sciences (India)

current-switching (ZCS) during turn-off. Due to soft-switching operation of the power switches and output diodes, the proposed ZVS DC–DC converter shows high efficiency. Steady-state analysis of the converter is presented to determine the circuit ...

A revista Saúde em Debate como fonte e objeto de estudo

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Daniela Carvalho Sophia

2013-11-01

Full Text Available A presente nota de pesquisa busca divulgar estudo sobre o Centro Brasileiro de Estudos da Saúde e o movimento de reforma sanitária desenvolvido no âmbito do Programa de História das Ciências e da Saúde Pública da Casa de Oswaldo Cruz. Atém-se à revista Saúde em Debate , periódico do Centro, devido à relevância que teve na área ao longo dos dez anos de publicação. A utilização da revista na pesquisa deu visibilidade a questões pertinentes à participação de seus membros na reforma sanitária. Enfatiza-se o fato de que a utilização do periódico como fonte e objeto de estudo para fomentar a produção de pesquisa na área da saúde merece investigação mais ampla.

Fontes de informação on line em Arquivologia: uma avaliação métrica

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Ely Francina T. de Oliveira

2009-04-01

Full Text Available O conhecimento é elemento fundamental na sobrevivência das espécies. A informação é necessária para formar o conhecimento que constrói a ciência. Esse fluxo beneficia os que produzem informação, bem como aqueles que a consomem. Não basta apenas pesquisar para se ter um novo domínio e conhecimento, é fundamental a publicação e validação pela comunidade científica. A ampla exposição das informações ao julgamento da comunidade é necessária para que a informação seja disseminada, exercendo assim sua principal função, que é de produzir conhecimento. A comunicação científica é importante indicador do desenvolvimento de uma área do conhecimento, pois possibilita a verificação e análise da comunidade na qual foi realizada. Por essa razão, o processo de atividade científica é dependente de um intrincado sistema de comunicação eficaz, que compreende canais formais e informais, que são utilizados tanto para comunicar os resultados obtidos como para informar os resultados alcançados por outros pesquisadores. Assim, toda pesquisa envolve atividades diversas de comunicação e disseminação. As informações publicadas variam de formatos, suporte e função. Podem ser veiculadas por meio impresso ou meio eletrônico, quer sejam artigos, livros, atas, conferências e revistas. O objetivo desta pesquisa é levantar as fontes de informação por meio eletrônico, através da Internet, os sites que têm revistas eletrônicas que publicam textos, artigos, teses, dissertações, projetos e trabalhos de pesquisa de estudiosos na área de Arquivologia. Considerando a informática como um fator fundamental no processo de recuperação da informação e a grande quantidade de informações abrangidas pela Internet, muitas vezes há dificuldade de localização de uma fonte específica, mesmo porque o meio eletrônico possui um espaço ilimitado de disponibilizar informação, não existindo limite para se pesquisar

DESENVOLVIMENTO DE UM MÉTODO MONTE CARLO NÃO PARAMÉTRICO PARA SIMULAR FONTES RADIATIVAS PLANARES EM MODELOS COMPUTACIONAIS DE EXPOSIÇÃO

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José Wilson Vieira

2014-07-01

Full Text Available Nos modelos computacionais de exposição (MCEs do DEN/UFPE, um fantoma (simulador antropomórfico é acoplado ao código Monte Carlo (MC EGSnrc para avaliações dosimétricas. Os modelos também precisam de um simulador da fonte emissora de radiação. Este trabalho apresenta um algoritmo MC não paramétrico de uma fonte radioativa planar, isotrópica por rotação, dependente da variável radial e da função de distribuição acumulada (FDA do problema, conhecida, mas não inversível. O algoritmo escolhe N valores da variável radial e calcula os correspondentes valores da função densidade de probabilidade (FDP e da FDA do problema. A suposição usada é que, se os valores da FDA fossem discretos, corresponderiam a frequências de raio (FR em intervalos consecutivos do domínio. Usando um gerador de números aleatórios (GNA uniformes normalizados em [0, 1, a técnica MC da inversão generalizada e interpolações lineares, foi possível obter amostras de r. Para comparações dosimétricas, foi reutilizado o MCE MSTA (Mash STAnding = fantoma MASH + EGSnrc + algoritmo baseado na FDP exponencial e montado o MSTA_FR. As implementações foram adicionadas ao software MonteCarlo, desenvolvido pelos autores e atualizado sempre que necessário. Os resultados apresentados e comentados estabelecem um novo algoritmo para uma fonte radioativa planar.

Development of microheaters for gas sensor with an AT-Mega 8535 temperature controller using a PWM (pulse width modulation) method

Science.gov (United States)

Megayanti, Meti; Panatarani, Camellia; Joni, I. Made

2016-03-01

Microheater is the main component in gas sensor characterized by their sensitivity, selectivity, and time response of gas sensor which is depend on the microheater temperature stability. A Cu microheater was developed and utilized AT-Mega 8535 controller using a PWM (pulse width modulation) method. This control system is interfaced to the PC to observe the real time temperature response of the microheater. Three initial resistance (R0) variations of microheater were developed in an open loop control system. The power characteristic of designed microheater depends on the specified microheater initial resistance. The smaller R0, the less power required to reach a temperature setting value. The developed microheater was designed to reach a temperature setting value of 250°C having resistance 0.531 Ω for 1.979 Watt and 0.265 Ω for 1.072 Watt respectively. The results of the investigation on the control performances shows microheater-control system achieved operating temperature up to 250°C. The response of the temperature control shows smallest R0 resulted in a high stability with short settling time, short delay time and small ripple for temperature setting values higher than 150°C. The obtained error of microheater temperature with R0 = 0.265 is 8.596 %. It is concluded that the developed microheater can be utilized as a component of a gas sensor.

Development of microheaters for gas sensor with an AT-Mega 8535 temperature controller using a PWM (pulse width modulation) method

Energy Technology Data Exchange (ETDEWEB)

Megayanti, Meti; Panatarani, Camellia; Joni, I. Made, E-mail: imadejoni@phys.unpad.ac.id [Instrumentation System and Functional Material Processing Laboratory, Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran Jalan Raya Bandung-Sumedang KM 21, Jatinangor 45363, West Java (Indonesia)

2016-03-11

Microheater is the main component in gas sensor characterized by their sensitivity, selectivity, and time response of gas sensor which is depend on the microheater temperature stability. A Cu microheater was developed and utilized AT-Mega 8535 controller using a PWM (pulse width modulation) method. This control system is interfaced to the PC to observe the real time temperature response of the microheater. Three initial resistance (R0) variations of microheater were developed in an open loop control system. The power characteristic of designed microheater depends on the specified microheater initial resistance. The smaller R0, the less power required to reach a temperature setting value. The developed microheater was designed to reach a temperature setting value of 250°C having resistance 0.531 Ω for 1.979 Watt and 0.265 Ω for 1.072 Watt respectively. The results of the investigation on the control performances shows microheater-control system achieved operating temperature up to 250°C. The response of the temperature control shows smallest R0 resulted in a high stability with short settling time, short delay time and small ripple for temperature setting values higher than 150°C. The obtained error of microheater temperature with R0 = 0.265 is 8.596 %. It is concluded that the developed microheater can be utilized as a component of a gas sensor.

Utilização de fontes de gorduras em rações de vacas leiteiras

OpenAIRE

José Esler de Freitas Júnior

2008-01-01

O objetivo deste estudo foi avaliar a utilização de diferentes fontes de gordura em rações de vacas em lactação sobre o consumo e digestibilidade dos nutrientes, fermentação ruminal, produção e composição do leite, composição da fração protéica do leite, balanço de energia e de nitrogênio. Foram utilizadas 12 vacas da raça Holandesa, agrupadas em três quadrados latinos balanceados 4x4, alimentadas com as seguintes rações: 1) Controle; 2) Óleo de soja refinado; 3) Grão de soja in natura; e 4) ...

AVALIAÇÃO DE FONTES DE CARBONO PARA A PRODUÇÃO DE INIBIDOR DE CRESCIMENTO DE Aspergillus fumigatus USP2 por Corynebacterium sp.

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Gabrielle Fernanda Zimmer

2013-07-01

Full Text Available O aumento significativo na incidência de infecções fúngicas invasivas e a resistência natural de agentes etiológicos a antifúngicos existentes têm motivado a constante pesquisa por novos agentes antifúngicos nos ultimos anos. Neste sentido, foi selcionada uma cepa de Corynebacterium sp. com potencial antagonista frente à Aspergilus fumigatus USP2. A cepa foi cultivada em fase submersa e em fase sólida, avaliando-se a variação das fontes de glicose, sacarose e glicerol em presença de peptona, bem como o meio sintético Czapek. Os caldos de cultivo submerso foram utilizados para o ensaio de antagonismo microbiano com o fungo Aspergillus fumigatus USP2. Os resultados apontam que o cultivo em fase sólida utilizando glicose como fonte de carbono apresenta maior potencial inibitório da cepa de Corynebacterium sp. sobre o fungo Aspergillus fumigatus USP2.

Achado dunhas lousas con arte megalítico en Fonte Tourón Lalín, Pontevedra

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Cabrejas Domínguez, Elena

2009-12-01

Full Text Available In an archaeological context before a works execution took place (an electric half tension line, some engraved gravestones were found around the area of Fonte Touron, Council of Lalín. These gravestones have engravings representative of megalithism and nowadays they became boundary markers of the yards in which they are. The features of the engravings, besides the very shape of the stones and the context where other mounds are located, and above everything, the information provided by local neighbors that relate the stones of this mound to one set apart some years ago, points that they were part of a megalithic monument, and it is highly probable that they were the orthostats of a chamber.

No contexto dos traballos arqueolóxicos previos á execución dunha obra (unha liña eléctrica de media tensión, localizáronse unhas lousas con gravados na zona de Fonte Tourón, en Lalín. Trátase dunhas lousas que presentan uns gravados de estilo propio do megalitismo e que agora forman parte dos lindes das fincas nas que se atopan. As características destes gravados, sumado á propia forma das pedras, a un contexto onde se localizan outras mámoas e sobre todo, á información dos veciños que vinculan estas pedras cunha mámoa desfeita fai uns anos, apuntan a que formaron parte dun monumento megalítico, e que moi probablemente se trata dos esteos dunha cámara.

Aspectos econômicos do uso de fontes orgânicas de nutrientes associadas a sistemas de preparo do solo Economical aspects of organic nutrient sources associated with soil tillage systems

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Carla Maria Pandolfo

2008-09-01

Full Text Available A análise econômica é fundamental para a tomada de decisão no uso de fontes orgânicas de nutrientes. O objetivo do trabalho foi avaliar aspectos econômicos do uso de fontes orgânicas de nutrientes para auxiliar a tomada de decisão sobre o seu uso em diferentes condições de manejo do solo. Foi utilizado um experimento conduzido durante nove anos na Estação Experimental da Epagri de Campos Novos/SC. Os tratamentos consistiram da combinação de cinco sistemas de preparo (plantio direto, preparo reduzido, preparo convencional, preparo convencional com resíduos queimados e preparo convencional com resíduos retirados, combinados com quatro fontes de nutrientes (TES - testemunha, sem aplicação de nutrientes, AM - adubação mineral de acordo com a recomendação para cada cultura, EA - 5mg ha-1 de matéria úmida de cama de aves, ELB - 60m³ ha-1 de dejeto líquido de bovinos e; ELS - 40m³ ha-1 de dejeto líquido de suínos. Os atributos econômicos utilizados foram os custos variáveis (CV, a receita bruta (RB e o custo da correção da fertilidade com calcário, P e K (CC, após nove anos de aplicação das fontes de nutrientes. A interpretação para cada combinação de fonte de nutriente e sistema de preparo do solo foi feita por meio de figuras triangulares e a área das mesmas com intervalo de confiança a 90% de probabilidade. Concluiu-se que o desempenho econômico das fontes orgânicas de nutrientes foi dependente do sistema de preparo do solo, sendo que as fontes apresentaram melhor desempenho no sistema plantio direto. O esterco de aves e o esterco líquido de suínos foram as fontes que apresentaram melhor desempenho econômico. O esterco líquido de suínos e o esterco líquido de bovinos, mesmo apresentando áreas diferentes, foram as fontes que apresentaram menor variabilidade nos atributos econômicos avaliados, não havendo um atributo que se destaque dos demais. O custo da correção da fertilidade do solo com calc

Novas citações de Chytridiomycota e Oomycota para o Parque Estadual das Fontes do Ipiranga (PEFI, SP, Brasil New records of Chytridiomycota and Oomycota from the "Parque Estadual das Fontes do Ipiranga (PEFI", SP, Brazil

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Carmen Lidia Amorim Pires-Zottarelli

2007-03-01

Full Text Available Levantamento de fungos zoospóricos realizado em lagos artificiais do Parque Estadual das Fontes do Ipiranga (PEFI, situado na cidade de São Paulo, Estado de São Paulo, Brasil, resultou no isolamento de 41 táxons, sendo 36 identificados em nível específico. Vinte e três táxons pertencem ao Reino Fungi, filo Chytridiomycota, ordens Chytridiales, Monoblepharidales e Spizellomicetales e, 18 ao Reino Straminipila, filo Oomycota, ordens Saprolegniales e Peronosporales. Dentre os fungos isolados, 14 são mencionados pela primeira vez para o PEFI: Aphanomyces helicoides von Minden, Catenochytridium kevorkianii Sparrow, Catenochytridium sp., Chytriomyces appendiculatus Karling, C. aureus Karling, C. hyalinus Karling, C. spinosus Fay, Diplophlyctis asteroidea Dogma, D. complicata (Willoughby Dogma, Karlingia dubia Karling, Nowakowskiella hemisphaerospora Shanor, Saprolegnia australis Elliott, Septochytrium variabile Berdan e Truittella sp., os quais são descritos, comentados e ilustrados. O gênero Truitella é mencionado pela primeira vez para o Brasil.A survey of zoosporic fungi from artificial lakes of the Fontes do Ipiranga State Park, in the city of São Paulo, São Paulo State, Brazil, yielded the isolation of 41 taxa with 36 species. Twenty-three taxa belong to Chytridiales, Monoblepharidales and Spizellomycetales of the Phylum Chytridiomycota, Fungi Kingdom and 18 belong to Saprolegniales and Peronosporales, Phylum Oomycota, Straminipila Kingdom. Of these, 14 are first-time records for this State Park: Aphanomyces helicoides von Minden, Catenochytridium kevorkianii Sparrow, Catenochytridium sp., Chytriomyces appendiculatus Karling, C. aureus Karling, C. hyalinus Karling, C. spinosus Fay, Diplophlyctis asteroidea Dogma, D. complicata (Willoughby Dogma, Karlingia dubia Karling, Nowakowskiella hemisphaerospora Shanor, Saprolegnia australis Elliott, Septochytrium variabile Berdan and Truittella sp., which are described, commented and

Fontes cotidianas de estresse entre mulheres portadoras de HIV Daily sources of stress among HIV-positive women

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Leticia Gaspar Tunala

2002-08-01

Full Text Available OBJETIVO: Categorizar e descrever as fontes de estresse cotidianas de mulheres portadoras do vírus da imunodeficiência humana (HIV. MÉTODOS: Foram realizadas entrevistas individuais, por meio de um questionário semi-estruturado, com uma amostra consecutiva de 150 mulheres portadoras do HIV, de julho a dezembro de 1997, no Centro de Referência e Tratamento de Doenças Sexualmente Transmissíveis e Aids (CRT DST/Aids (Secretaria de Estado da Saúde, SP. As variáveis investigadas foram: dados demográficos, estrutura familiar, percepção de risco, sexualidade, acesso ao sistema de saúde, adesão ao tratamento, uso de álcool e drogas, evento significativo e evento estressante, sendo este o foco de discussão do artigo. RESULTADOS: Apenas 14% dos eventos estressantes são diretamente resultados do tratamento ou do adoecimento. Os relatos das fontes de estresse foram distribuídos nos seguintes assuntos: familiares (17%; relacionamento com o parceiro (12%; filhos (14%; enfermidade (14%; relacionamento com outras pessoas (9%; problemas financeiros (8% e profissionais (7%; vivências de discriminação (7%; outros (4%; e não responderam (8%. CONCLUSÕES: As fontes de estresse apresentam principalmente um conteúdo afetivo-relacional, derivadas muitas vezes do estigma associado ao HIV e, na maioria das vezes, a temas comuns a todas as mulheres. Os profissionais de saúde deveriam oferecer cuidado integral às mulheres portadoras do HIV.OBJECTIVE: To categorize and describe the daily sources of stress encountered by HIV-infected women. METHODS: Using a semi-structured questionnaire, 150 interviews were conducted among HIV-infected women who attended the Reference and Treatment Center for Sexually Transmitted Diseases and Aids in the state of São Paulo, Brazil, between July and December 1997. The studied variables were: demographics, family structure, risk perception, sexuality, access to health system, treatment compliance, drug use, and

Novas citações de Chytridiomycota e Oomycota para o Parque Estadual das Fontes do Ipiranga (PEFI), SP, Brasil

OpenAIRE

Pires-Zottarelli,Carmen Lidia Amorim; Rocha,Maristela

2007-01-01

Levantamento de fungos zoospóricos realizado em lagos artificiais do Parque Estadual das Fontes do Ipiranga (PEFI), situado na cidade de São Paulo, Estado de São Paulo, Brasil, resultou no isolamento de 41 táxons, sendo 36 identificados em nível específico. Vinte e três táxons pertencem ao Reino Fungi, filo Chytridiomycota, ordens Chytridiales, Monoblepharidales e Spizellomicetales e, 18 ao Reino Straminipila, filo Oomycota, ordens Saprolegniales e Peronosporales. Dentre os fungos isolados, 1...

The relationship between lymphocytes activated by pokeweed mitogen and by lipopolysaccharides and their radiosensitivity

International Nuclear Information System (INIS)

Su Liaoyuan; Liu Fenju; Liu Keliang; Xu Changshao; Xu Yingdong; Geng Yongzhi

1992-07-01

Human whole blood was incubated in vitro. Lymphocytes were activated by poke-weed mitogen (PWM) and by Lipopolysaccharides (LPS). The relationship between the two kinds of lymphocytes was investigated using radioactive compound incorporation. The study showed that PWM-activated lymphocytes were able to promote the stimulating effect of LPS on B lymphocytes. The stimulating effect of PWM-activated lymphocytes was obviously decreased after they were irradiated with 10 Gy gamma rays. When PWM-activated lymphocytes and LPS-activated lymphocytes were incubated together after one of the cell populations had been exposed 10 Gy 60 Co gamma rays, the incorporation of [ 3 H] TdR was much decreased and the synergistic function disappeared, especially when the PWM-activated lymphocytes were irradiated. In cells from patients treated with 60 Co gamma rays for carcinoma of nasopharynx, the incorporation in LPS-activated lymphocytes approached normal levels while that in PWM-activated lymphocytes was reduced significantly and the stimulating effect of PWM-activated lymphocytes on LPS-activated lymphocytes was also markedly reduced. These demonstrate that PWM-activated lymphocytes have a similar function to T-helper cells and seem to be more radiosensitive than LPS-activated lymphocytes

An Algebraic Method of Synchronous Pulsewidth Modulation for Converters for Adjustable Speed Drives

DEFF Research Database (Denmark)

Oleschuk, Valentin; Blaabjerg, Frede

2002-01-01

This paper describes the basic peculiarities of a new method of feedforward synchronous pulsewidth modulation (PWM) of the output voltage of converters, based on one-stage closed-form strategy of PWM with pure algebraic control dependencies. It is applied to voltage source inverters with a contin......This paper describes the basic peculiarities of a new method of feedforward synchronous pulsewidth modulation (PWM) of the output voltage of converters, based on one-stage closed-form strategy of PWM with pure algebraic control dependencies. It is applied to voltage source inverters...... with a continuous scheme of conventional voltage space vector modulation and with two basic variants of symmetrical discontinuous PWM. Simulations give the behaviour of the proposed method and show the advantage of algebraic synchronous PWM compared with the typical asynchronous, for low indices of the frequency...

A fonte ionizante do disco de acreção no núcleo de NGC1097

Science.gov (United States)

Silva, R. N.; Storchi-Bergmann, T.

2003-08-01

Observações em raios-X revelam o "coração" dos núcleos ativos de galáxias, pois esse tipo de radiação provém das suas regiões mais internas, próximas ao buraco negro central. Neste trabalho apresentamos observações em raios-X da região central da galáxia NGC1097, que hospeda um buraco negro supermassivo e um disco de acreção cuja emissão vem sendo observada há dez anos através da linha de emissão Ha larga (10000 km/s) e de duplo pico. As observações em raios-X - que foram obtidas com o Telescópio Chandra - foram combinadas com observações no ultravioleta obtidas com o Telescópio Espacial Hubble e são usadas para estudar as características da fonte central que ioniza o disco de acreção. A distribuição espectral de energia é comparada com a predita por modelos, em particular o de uma estrutura "ADAF" ("advection dominated accretion flow") na parte interna do disco. Tal estrutura produz um espectro de emissão de linhas estreitas tipo LINER, como observado em NGC1097 e em rádio-galáxias que apresentam linhas de Balmer largas de duplo pico. Apresentamos também uma comparação entre outros LINERs com linhas de emissão largas de duplo pico, disponíveis na literatura ou nos arquivos do Chandra e do Telescópio Espacial Hubble e discutimos as correspondentes implicações para modelos da fonte central.

Fontes de nitrogênio e caule decomposto de Mauritia flexuosa na nodulação e crescimento de Enterolobium contortsiliquum

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Waldeídes Castro Sousa

2013-10-01

Full Text Available Avaliaram-se fontes de nitrogênio (N e proporções de caule decomposto de buritizeiro (Mauritia flexuosa L.f. na nodulação, crescimento e nos índices biométricos das mudas de tamboril [Enterolobium contortsiliquum (Vell. Morong] na região sudoeste do Piauí. O delineamento experimental foi inteiramente casualizado em esquema fatorial 3x5, com cinco repetições. Foram testadas três fontes de N (N-mineral, N do substrato e inoculação com a estirpe Bradyrhizobium elkanii BR 4406 e cinco proporções de caule decomposto de buritizeiro:solo (v/v, %: 0: 100; 10: 90; 20: 80; 40: 60; 80: 20. A emergência das plântulas foi avaliada diariamente até o décimo terceiro dia após a semeadura. Aos 80 dias, as mudas foram coletadas para as determinações da nodulação, do crescimento e dos índices biométricos. As mudas que foram cultivadas com os substratos contendo caule decomposto de buritizeiro apresentaram maior crescimento e nodulação, em relação às que foram cultivadas no substrato 0: 100 (caule decomposto de buritizeiro: solo. A obtenção de máximo Índice de Qualidade de Dickson foi com 48: 52 (caule decomposto de buritizeiro: solo, sendo, portanto, esta a proporção recomendada para a produção de mudas. Com relação às fontes de nitrogênio, a estirpe BR 4406 não foi eficiente em promover ganhos no teor de nitrogênio e matéria seca da parte aérea, em relação ao tratamento com N-mineral. As populações nativas de bactérias diazotróficas presentes no substrato que não recebeu N-mineral e nem inoculação foram capazes de nodular eficientemente o tamboril, uma vez que promoveram acréscimos no teor de nitrogênio e matéria seca da parte aérea equivalentes ao tratamento adubado com N-mineral.

Fontes de energia em suplementos múltiplos para novilhos em pastejo durante o período das águas Energy sources in multiple supplements for steers on pasture during rainy season

Directory of Open Access Journals (Sweden)

Michele Lopes do Nascimento

2010-04-01

Full Text Available Avaliou-se a influência do fornecimento de fontes de energia amiláceas e fibrosas em suplementos múltiplos sobre o desempenho e as características nutricionais de novilhos mestiços Holandês × Zebu em terminação em pastagem de Brachiaria decumbens Stapf. no período das águas. A área experimental consistiu de cinco piquetes de 2,0 ha, com disponibilidade média de MS de 5.853,0 kg/ha. Utilizaram-se 24 novilhos mestiços castrados, com aproximadamente 27 meses de idade e peso vivo inicial de 377,03 ± 7,28 kg. A cada animal, destinou-se casualmente um dos suplementos: mistura mineral à vontade, grão de sorgo ou grão de milho como fontes amiláceas de energia; e casca de soja ou farelo de trigo como fontes fibrosas. Às fontes de energia foram adicionados: mistura mineral, farelo de algodão e ureia para comporem suplementos com 33% de PB, com base na matéria seca, fornecidos na proporção de 1,0 kg/animal/dia. Nos animais sob suplementação com fontes energéticas, o ganho médio diário foi 33,4% maior. Os novilhos que consumiram suplemento com grão de sorgo foram os que apresentaram maior ganho de peso médio diário e maiores consumos nutrientes do pasto em comparação aos que consumiram grão de milho. A digestibilidade aparente total da fibra em detergente neutro corrigida para cinzas e proteína não foi afetada pela suplementação, independentemente da fonte de energia. O teor de nitrogênio ureico urinário foi menor nos animais sem suplementação. Suplementos múltiplos fornecidos em quantidade equivalente a 0,3% do peso vivo promovem ganho de peso superior ao obtido com mistura mineral em novilhos mestiços na fase de terminação durante o período das águas. Suplementos formulados com fontes fibrosas ou fontes amiláceas proporcionam desempenho produtivo semelhante.This study evaluated the supply of starch and fibrous energy in multiple supllements on the performance and nutritional characteristics of finishing

The Potential of Digital Tools in Art Lessons at Junior School Level to Improve Artistic Ability Using Tamazight Fonts

OpenAIRE

Aber Salem Aboalgasm; Rupert Ward

2014-01-01

The aim of this research is to explore how pupils in art classes can use creative digital art tools to redesign Tamazight fonts, in order to develop children’s artistic creativity, enable them to learn about a new culture, and to help the teacher assess the creativity of pupils in the art class. It can also help students to improve their talents in drawing. The study could relate to research in Libya among the Amazigh people (better known as Berber) and possibly the development of Tamazight f...

A Modified High-Efficient Step-Up Sepic for DC Motor Drives

Directory of Open Access Journals (Sweden)

P. Dhanasekaran

2013-12-01

Full Text Available In this paper, Single-Ended Primary Inductor Converter (SEPIC fed DC motor is proposed. Soft-switching technique such as Zero-Voltage-Switching (ZVS and Zero-Current-Switching (ZCS operation plays a vital role in high voltage applications. Zero-Current-Switching (ZCS operation achieved due to resonance between the resonant inductor and the capacitor by using output diode and its reverse-recovery loss is subsequently reduced. Zero-Voltage-Switching (ZVS operation is achieved by using coupled inductor and auxiliary inductor. The model has been simulated through MATLAB/SIMULINK using Diode Bridge, SEPIC topology and closed loop DC motor load and it is modeled analytically. The proposed system is modeled with input side Diode Bridge Rectifier and SEPIC Topology with Proportional Integral (PI controller. The soft switching scheme for the proposed topology is developed with closed loop motor load. The motor voltage is achieved twice the rated voltage. The results are generated in MATLAB/SIMULINK and are shown.

Means-source on the international pages of O Estado de S. Paulo Meios-fonte nas pginas de internacional de O Estado de S. Paulo

Directory of Open Access Journals (Sweden)

Angela Zamin

2012-01-01

Full Text Available On journalistic production, the objectivation of each event involves a conflict of perspectives between journalists and sources through the present definition that surrounds us. These combats are established in the discursive level, among social controls and pressures for what to say and how to say it, being conformed within an information network built up from priorities on which informational efforts in each media are focused. This article approaches the use of other medias (newspapers, radio and TV stations by the newspaper O Estado de S. Paulo as sources for the signification of the diplomatic crisis between Colombia and Ecuador, in the period from March 2008 to August 2009. The article is guided by a debate on the implications of the means-source used by the journalistic production about international occurrences. For the analysis the corpus is based on 307 pieces of the International section.Na produo jornalstica, a objetivao de cada acontecimento envolve um conflito de perspectivas entre jornalistas e fontes pela definio do presente que nos cerca. Esses combates se estabelecem no discursivo, em meio a controles e presses sociais pelo que dizer e como dizer, sendo conformados no interior de uma rede informativa estabelecida a partir de prioridades sobre as quais se concentram os esforos informativos de cada meio. Este artigo aborda o uso de outros meios (jornais, rdios, TVs pelo jornal O Estado de S. Paulo como fontes na significao da crise diplomtica entre Colmbia e Equador, no perodo de maro de 2008 a agosto de 2009. Orienta-se por um debate acerca das implicaes do emprego de meios-fonte na produo jornalstica que versa sobre ocorrncias internacionais. Para a anlise serve de base um corpus de 307 peas da editoria de Internacional.

Vibração: fonte de incômodo à populaçao e de danos às edificações no meio urbano

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Luiz Antonio Brito

Full Text Available A energia vibratória gerada pelo tráfego de veículos leves e pesados e pelas composições ferroviárias são uma fonte de poluição ambiental pouco estudada no Brasil. A forma mais eficaz de atenuação da energia vibratória é o aumento da distância entre o receptor e a fonte, o que normalmente é obtido com os recuos definidos pelas leis de zoneamento urbano e pela faixa de domínio, tanto de ferrovias como de rodovias. O adensamento das áreas urbanas, já perceptível nas cidades de médio porte, gerado principalmente pela especulação imobiliária, vem aproximando as edificações das principais fontes de vibração no meio urbano. O efeito da energia vibratória nas edificações varia de acordo com o tipo de estrutura e fundação, sua altura e o tipo de solo. As construções que possuem estrutura em aço ou concreto armado tendem a receber melhor os efeitos da vibração (DIN 4150-3,1999. Em contrapartida, as construções antigas e patrimônios históricos, edificados com materiais menos resistentes, em algumas situações mal conservadas, podem sofrer desde trincas estéticas até danos estruturais irreversíveis quando expostas a elevados níveis de vibração. O objetivo deste trabalho é avaliar a incomodidade e os danos estruturais gerados pela energia vibratória induzida pelo tráfego rodoviário e ferroviário em edificações. Os resultados obtidos indicam que os limites de integridade estrutural são atendidos, mas não os de incomodidade.

Biodisponibilidade de cobre de diferentes fontes para coelhos

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Cavalcante S.G.

2002-01-01

Full Text Available Utilizaram-se 140 coelhos das raças Nova Zelândia Branco e Califórnia, com 60 dias de idade, de ambos os sexos, distribuídos em 14 tratamentos experimentais, com o objetivo de determinar a biodisponibilidade de cobre (Cu de três fontes inorgânicas, óxido de cobre (tratamento OC, sulfato de cobre (tratamento SC e carbonato de cobre (tratamento CC e uma orgânica, quelato de cobre (tratamento QC, usadas nas concentrações de 0, 20, 40, 80 e 160 ppm para a curva padrão. O maior consumo de ração ocorreu nos tratamentos 80SC, 80OC, 40SC, 160SC, 0C, 20SC, 40CC e 40OC e os menores resultados nos tratamentos 160QC, 40QC, 80CC, 160CC e 160OC (R²= 0,1913. Para ganho de peso o melhor tratamento foi 80SC e o pior 80CC (R²=0,2358. Para conversão alimentar, os tratamentos 80CC, 80SC, 0C, 20SC e 80QC apresentaram nessa ordem os maiores valores e o menor valor foi em 40QC. Para o cobre no fígado, o tratamento 160CC apresentou o maior valor, e 80SC e 40SC os menores. Não houve diferenças com relação ao sexo, mas os animais Nova Zelândia Branco apresentaram maior deposição de cobre. Pelos resultados chegou-se à equação de regressão: Y Cu= 1,37 + 3,83 x1 + 2,77 x2 + 2,83 x3 + 2,84 x4 + 2,84 x5 (R² = 0,3288.

A time for dogma, a time for the Bible, a time for condoms: Building a Catholic theology of prevention in the face of public health policies at Casa Fonte Colombo in Porto Alegre, Brazil

Science.gov (United States)

Seffner, Fernando; Garcia, Jonathan; Muñoz-Laboy, Miguel; Parker, Richard

2011-01-01

The Casa Fonte Colombo (CFC) is a religious organisation that assists people living with HIV/AIDS (PLWHA). The funding for its activities comes from public sources such as the Brazilian National STD/AIDS Program as well as the Catholic Church. Capuchin (Franciscan) priests run the CFC, and it has an extensive group of volunteers made up mostly of women. Between 2006 and 2009, we observed daily life at the Casa Fonte Colombo and interviewed priests, volunteers, employees, service providers, and clients. We also attended meetings, group sessions, and celebrations. Everyday actions carried out by the CFC reveal the efforts to resolve the tension between the position of the Catholic Church and the Brazilian state in the politics of AIDS. These efforts affirm that the Casa Fonte Colombo presents itself as a space where the position of the Catholic Church, as much as the politics of public health, are re-worked, giving way to a progressive act of Catholic prevention and assistance for AIDS, that we call “theology of prevention.” PMID:21834734

Switching power supplies with multiple isolated output and unitary power factor with an only switch; Fonte chaveada com multiplas saidas isoladas e fator de potencia unitario com um unico interruptor

Energy Technology Data Exchange (ETDEWEB)

Canesin, Carlos Alberto

1990-09-01

The analysis and implementation of switching power supplies with multiple output, through the use of the D C/D C Single Ended Primary Inductance Converter - SEPIC is presented. The structure has a single switch mode processing stage, improved input power factor, with the use of the variable current hysteresis control, or, constant on time control. The analysis of the D C/D C SEPIC, output characteristics and computer simulation is presented. A switching power supply practical design and experimental results are presented to demonstrate the validity of the theoretical analysis. (author)

Assessment of clusters of transcription factor binding sites in relationship to human promoter, CpG islands and gene expression

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Sakaki Yoshiyuki

2004-02-01

Full Text Available Abstract Background Gene expression is regulated mainly by transcription factors (TFs that interact with regulatory cis-elements on DNA sequences. To identify functional regulatory elements, computer searching can predict TF binding sites (TFBS using position weight matrices (PWMs that represent positional base frequencies of collected experimentally determined TFBS. A disadvantage of this approach is the large output of results for genomic DNA. One strategy to identify genuine TFBS is to utilize local concentrations of predicted TFBS. It is unclear whether there is a general tendency for TFBS to cluster at promoter regions, although this is the case for certain TFBS. Also unclear is the identification of TFs that have TFBS concentrated in promoters and to what level this occurs. This study hopes to answer some of these questions. Results We developed the cluster score measure to evaluate the correlation between predicted TFBS clusters and promoter sequences for each PWM. Non-promoter sequences were used as a control. Using the cluster score, we identified a PWM group called PWM-PCP, in which TFBS clusters positively correlate with promoters, and another PWM group called PWM-NCP, in which TFBS clusters negatively correlate with promoters. The PWM-PCP group comprises 47% of the 199 vertebrate PWMs, while the PWM-NCP group occupied 11 percent. After reducing the effect of CpG islands (CGI against the clusters using partial correlation coefficients among three properties (promoter, CGI and predicted TFBS cluster, we identified two PWM groups including those strongly correlated with CGI and those not correlated with CGI. Conclusion Not all PWMs predict TFBS correlated with human promoter sequences. Two main PWM groups were identified: (1 those that show TFBS clustered in promoters associated with CGI, and (2 those that show TFBS clustered in promoters independent of CGI. Assessment of PWM matches will allow more positive interpretation of TFBS in

Novas Fontes, Novas Versões: Contribuições do Acervo da Comissão Nacional da Verdade

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Alessandra Sá Mello Costa

2017-03-01

Full Text Available Na área de estudos organizacionais, o interesse dos pesquisadores em utilizar fontes e acervos históricos em suas pesquisas cresce a cada dia (Rowlinson, Hassard, & Decker, 2014; Yates, 2014. Como forma de enriquecer e aprofundar a discussão sobre esse movimento, a presente pesquisa tem por objetivo refletir sobre possíveis contribuições das fontes reunidas, sistematizadas e produzidas pela Comissão Nacional da Verdade (CNV. Instituída para investigar as graves violações dos direitos humanos cometidas no regime da ditadura civil-militar brasileira, a CNV (a partir de seu acervo oferece aos pesquisadores das organizações novas versões dos fatos históricos, o que torna possível não só problematizar e rever versões históricas oficiais hegemônicas, mas também investigar fenômenos organizacionais sob outras perspectivas. Assim, após a descrição do processo de constituição e de composição do seu acervo documental, foram elencadas quatro avenidas de pesquisas iniciais: (a sobre o apoio e a participação da sociedade civil na constituição e manutenção do governo civil-militar brasileiro; (b sobre a formação de redes de agentes sociais envolvidos no processo de criação e de trabalho da CNV; (c sobre as relações de trabalho durante o período, como a atuação dos sindicatos ou as práticas de recursos humanos sob um regime autoritário; e (d sobre o tema da história e memória das empresas.

Substituição parcial do milho por fontes energéticas para bovinos de corte em pastejo

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Adriano Borges Cardoso

2013-09-01

Full Text Available O objetivo deste trabalho foi avaliar o efeito da substituição parcial do milho por fontes energéticas alternativas, em suplementos concentrados para bovinos de corte mantidos em pasto de Urochloa brizantha cultivar Marandu, durante o período das águas, no consumo e na digestibilidade aparente total dos alimentos. Foram utilizados cinco bovinos Nelore com peso médio corporal inicial de 367,8±4,31 kg. Utilizou-se o delineamento experimental quadrado latino 5x5, com cinco animais e cinco tratamentos. Foram avaliados: suplementos concentrados isoproteicos, com 30% de proteína bruta, formulados à base de grãos de milho, de milheto e de sorgo, e casca de soja; e um suplemento mineral (controle. Não foram observadas diferenças significativas no consumo de matéria seca (MS total e de matéria orgânica (MO entre os animais que receberam suplementação mineral e os que receberam suplementação concentrada; no entanto, estes últimos apresentaram menor (12,28% consumo de MS de pasto. A suplementação concentrada aumentou o coeficiente de digestibilidade aparente total da MS, da MO, da proteína bruta e dos carboidratos não fibrosos que não foram influenciados pelas fontes de energia. Os grãos de milheto e de sorgo e a casca de soja podem ser utilizados em substituição parcial ao milho, na formulação de suplementos concentrados, sem prejudicar o consumo e a digestibilidade dos nutrientes da dieta.

Perfil lipídico tecidual de ratos alimentados com diferentes fontes lipídicas Tissue lipid profile of rats fed with different lipid sources

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Martha Elisa Ferreira de Almeida

2009-02-01

Full Text Available OBJETIVO:Determinar se fontes lipídicas com diferentes razões de ácidos graxos insaturados e saturados (PUFA+MUFA/SFA na dieta altera o perfil lipídico tecidual, a concentração de lipídios (mg/g dos tecidos hepáticos e mesentérico e a digestibilidade lipídica. MÉTODOS: Foi realizada cromatografia gasosa para determinar o perfil de ácidos graxos nos tecidos hepático e adiposo de ratos alimentados com diferentes fontes lipídicas. O coeficiente de digestibilidade foi determinado a partir da relação entre a quantidade de lipídios consumidos e a quantidade fecal excretada. RESULTADOS:Diferentes fontes lipídicas (óleo de soja, manteiga, margarina e gorduras de porco e de peixe não alteraram o coeficiente de digestibilidade e o peso hepático, mas alteraram a deposição de lipídios em todos os tecidos adiposos estudados. Não foi possível fazer a correlação direta entre o perfil dietário dos ácidos graxos não essenciais e sua deposição nos tecidos estudados, visto que a lipogênese de novo impede a identificação dos ácidos graxos dietários. CONCLUSÃO:Não foi constatada uma relação direta entre o perfil dietário dos ácidos graxos e sua deposição nos tecidos estudados, exceto para os ácidos graxos trans e linoléico (C18:2 que não são sintetizados no rato. Esses ácidos graxos apresentaram uma concentração tecidual diretamente proporcional àquela das fontes dietárias. Quanto à razão (PUFA+MUFA/SFA, encontrada no tecido hepático dos diferentes grupos, observa-se que esta foi diretamente proporcional aos valores apresentados pelas fontes lipídicas dietárias. Entretanto, essa associação não foi observada nos tecidos adiposos analisados.OBJECTIVE:To determine if lipid sources with different unsaturated to saturated fatty acid ratios, (PUFA+MUFA/SFA in the diet alter the lipid profile of tissues, the lipid concentration (mg/g of the hepatic and mesenteric tissues and the lipid digestibility. METHODS

A Cell-to-Cell Battery Equalizer With Zero-Current Switching and Zero-Voltage Gap Based on Quasi-Resonant LC Converter and Boost Converter

DEFF Research Database (Denmark)

Shang, Yunlong; Zhang, Chenghui; Cui, Naxin

2015-01-01

these difficulties, an innovative direct cell-to-cell battery equalizer based on quasi-resonant LC converter (QRLCC) and boost DC-DC converter (BDDC) is proposed. The QRLCC is employed to gain zero-current switching (ZCS), leading to a reduction of power losses. The BDDC is employed to enhance the equalization...

Uso da alga Lithothamnium calcareum como fonte alternativa de cálcio nas rações de frangos de corte Use of algae Lithothamnium calcareum as alternative source of calcium in diets for broiler chickens

OpenAIRE

André Carreira Carlos; Nilva Kazue Sakomura; Sandra Regina Freitas Pinheiro; Fernando Marcelo Micai Toledano; Renato Giacometti; José Walter da Silva Júnior

2011-01-01

Objetivou-se, com este trabalho, avaliar o uso da alga Lithothamnium calcareum (Pallas) Areschoug nas rações para frangos de corte de 1 a 21 e 21 a 42 dias de idade, em substituição à fonte de cálcio tradicional (calcário calcítico). Para isso, foram utilizados 300 pintos machos, da linhagem Cobb®, que receberam rações contendo o calcário calcítico e a alga Lithothamnium calcareum (colhida de inteira e na forma de areia biodentrítica) como fontes de cálcio. O delineamento experimental utiliza...

Cytokine and immunoglobulin production by PWM-stimulated peripheral and tumor-infiltrating lymphocytes of undifferentiated nasopharyngeal carcinoma (NPC) patients

International Nuclear Information System (INIS)

Fliss-Jaber, Lilia; Houissa-Kastally, Radhia; Bouzouita, Kamel; Khediri, Naceur; Khelifa, Ridha

2004-01-01

Undifferentiated Nasopharyngeal Carcinoma (NPC) patients show a characteristic pattern of antibody responses to the Epstein-Barr virus (EBV) which is regularly associated with this tumor. However, no EBV-specific cytotoxic activity is detectable by the standard chromium-release assay at both peripheral and intratumoral levels. The mechanisms underlying this discrepancy between the humoral and cellular immune responses in NPC are still unknown, but might be related to an imbalance in immunoregulatory interleukin production. In this report, we investigated the ability of peripheral (PBL) and tumor- infiltrating (TIL) lymphocytes of undifferentiated NPC patients to produce in vitro three interleukins (IL-2, IL-6, IL-10) and three immunoglobulin isotypes (IgM, IgG, IgA). Lymphocytes from 17 patients and 17 controls were cultured in the presence of Pokeweed mitogen (PWM) for 12 days and their culture supernatants were tested for interleukins and immunoglobulins by specific enzyme-linked immunosorbent assays (ELISA). Data were analysed using Student's t-test and probability values below 5% were considered significant. The data obtained indicated that TIL of NPC patients produced significantly more IL-2 (p = 0,0002), IL-10 (p = 0,020), IgM (p= 0,0003) and IgG (p < 0,0001) than their PBL. On the other hand, patients PBL produced significantly higher levels of IL-2 (p = 0,022), IL-10 (p = 0,016) and IgM (p = 0,004) than those of controls. No significant differences for IL-6 and IgA were observed. Taken together, our data reinforce the possibility of an imbalance in immunoregulatory interleukin production in NPC patients. An increased ability to produce cytokines such as IL-10 may underlie the discrepancy between humoral and cellular immune responses characteristic of NPC

Subpopulation of human helper and suppressor T lymphocytes

International Nuclear Information System (INIS)

Venkataraman, M.; Levin, R.D.; Westerman, M.P.

1983-01-01

Mitogen driven differentiation of normal human mononuclear cells is a well-established model for the study of antibody synthesis in man. In certain rare individuals who are clinically normal, unfractionated mononuclear cells or a mixture of purified B plus T lymphocytes differentiate into immunoglobulin producing cells in response to purified protein derivative of tuberculin (PPD) but not in response to pokeweed mitogen (PWM). To evaluate this observation we have irradiated T cells from such individuals to eliminate naturally occurring suppressor T cell activity and then added the irradiated T cells back to autologous B cells before culture. The B cells then responded to PWM. The original PPD responses of cells from these individuals were now significantly reduced. Although, there was no difference between PWM nonresponders and responders in the number of OKT-8 positive cells, elimination of OKT-8 positive cells in the PWM nonresponders with OKT-8 monoclonal antibody and complement resulted in a significantly increased response to PWM. This study indicates that there are suppressor T cells which specifically inhibit B cell response to PWM without affecting the PPD response. These results also show that the helper T cells involved in the PWM response are radioresistant and those involved in the PPD response are radiosensitive

Investigation of thermodynamic parameters in the thermal decomposition of plastic waste-waste lube oil compounds.

Science.gov (United States)

Kim, Yong Sang; Kim, Young Seok; Kim, Sung Hyun

2010-07-01

Thermal decomposition properties of plastic waste-waste lube oil compounds were investigated under nonisothermal conditions. Polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyethylene terephthalate (PET) were selected as representative household plastic wastes. A plastic waste mixture (PWM) and waste lube oil (WLO) were mixed with mixing ratios of 33, 50, and 67 (w/w) % on a PWM weight basis, and thermogravimetric (TG) experiments were performed from 25 to 600 degrees C. The Flynn-Wall method and the Ozawa-Flynn-Wall method were used for analyses of thermodynamic parameters. In this study, activation energies of PWM/WLO compounds ranged from 73.4 to 229.6 kJ/mol between 0.2 and 0.8 of normalized mass conversions, and the 50% PWM/WLO compound had lower activation energies and enthalpies among the PWM/WLO samples at each mass conversion. At the point of maximum differential mass conversion, the analyzed activation energies, enthalpies, entropies, and Gibbs free energies indicated that mixing PWM and WLO has advantages in reducing energy to decrease the degree of disorder. However, no difference in overall energy that would require overcoming both thermal decomposition reactions and degree of disorder was observed among PWM/WLO compounds under these experimental conditions.

Panorama de les fonts audiovisuals internacionals en televisió : contingut, gestió i drets

Directory of Open Access Journals (Sweden)

López de Solís, Iris

2014-12-01

Full Text Available Les cadenes generalistes espanyoles (nacionals i autonòmiques disposen de diferents fonts audiovisuals per informar dels temes internacionals, com ara agències, consorcis de notícies i corresponsalies. En aquest article, a partir de les dades facilitades per diferents cadenes, s'aborda la cobertura, l'ús i la gestió d'aquestes fonts, així com també els seus drets d'ús i arxivament, i s'analitza la història i les eines en línia de les agències més emprades. Finalment, es descriu la tasca diària del departament d'Eurovision de TVE, al qual fa uns mesos s'han incorporat documentalistes que, a més de tractar documentalment el material audiovisual, duen a terme tasques d'edició i de producció.Las cadenas generalistas españolas (nacionales y autonómicas cuentan con diferentes fuentes audiovisuales para informar de los temas internacionales, como agencias, consorcios de noticias y corresponsalías. En este artículo, a partir de los datos facilitados por diferentes cadenas, se aborda la cobertura, el uso y la gestión de dichas fuentes, así como sus derechos de uso y archivado, y se analiza la historia y las herramientas en línea de las agencias más empleadas. Finalmente se describe la labor diaria del departamento de Eurovision de TVE, al que hace unos meses se han incorporado documentalistas que, además de tratar documentalmente el material audiovisual, realizan labores de edición y producción.At both national and regional levels, Spain’s main public service television channels rely upon a number of independent producers of audiovisual content to deliver news on international affairs, including news agencies and consortia and correspondent networks. Using the data provided by different channels, this paper examines the coverage, use and management of these sources as well as the regulations determining their use and storage. It also analyzes the history of the most prominent agencies and the online toolkits they offer

Growth of Bauhinia forficata Link, Curcuma zedoaria Roscoe and Phaseolus vulgaris L. cell suspension cultures with carbon sources Crescimento de cultura de células em suspensão de Bauhinia forficata Link, Curcuma zedoaria Roscoe e Phaseolus vulgaris L. em fontes de carbono

Directory of Open Access Journals (Sweden)

Marcia Ometto Mello

2001-09-01

Full Text Available Cell suspension cultures of Bauhinia forficata Link, Curcuma zedoaria Roscoe and Phaseolus vulgaris L. were used to test plant ability to utilize an alternative to sucrose as carbon source and energy for growth. Glycerol, sorbitol and galactose were the alternative carbon sources tested. Cell suspension cultures established on liquid medium containing sucrose were transferred to culture medium supplemented with sucrose or glycerol, or sorbitol, or galactose as the sole carbon source. Fresh and dry weight increasing and protein content showed marked differences among the different carbon sources used. Sucrose was the best carbon source for all the three plant species tested. Galactose and glycerol promoted slow or no growth of the three studied species. Sucrose in liquid medium promoted initiation of meristemoid formation. Sorbitol, which was ineffective on promoting significant growth, was the only alternative carbon source tested that also promoted this effect.Culturas de células em suspensão de Bauhinia forficata Link, Curcuma zedoaria Roscoe e Phaseolus vulgaris L. foram usadas para avaliar a eficiência de fontes alternativas de carbono e energia. Glicerol, sorbitol e galactose foram as fontes alternativas estudadas. As culturas de células estabelecidas em meio líquido contendo sacarose foram transferidas para meios de cultura suplementados com sacarose ou glicerol ou sorbitol ou galactose. A fonte de carbono afetou distintamente os ganhos de matéria fresca, matéria seca e o acúmulo de proteína. A sacarose foi a melhor fonte de carbono para as três espécies estudadas. Galactose e glicerol promoveram pequeno crescimento das três espécies estudadas. A sacarose utilizada como fonte de carbono no meio líquido, promoveu o início de organização celular conhecido como a formação de meristemóides. Sorbitol, que não promoveu crescimento significativo, foi a única fonte alternativa de carbono testada que também promoveu este

Sobre a origem e dispersão das leishmanioses cutânea e mucosa com base em fontes históricas pré e pós-colombianas

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Altamirano-Enciso Alfredo J.

2003-01-01

Full Text Available A partir de quatro fontes do século XVI, são relatadas algumas ocorrências sugestivas de leishmaniose tegumentar americana (LTA no território andino. A reinterpretação dessas fontes permite enfocar o velho tema da origem da espundia ou leishmaniose de forma mucosa (LM. O artigo reforça a hipótese de que a LM tenha se originado na área amazônica ocidental em tempos arqueológicos por intermédio de migrações humanas, depois ascendido à selva alta e, posteriormente, às terras quentes interandinas, pelos limites da Bolívia e do Peru com o Brasil. As migrações dos mitmaq ou mitimaes contribuíram para sua intensificação durante o império inca. Tais fatos se desenvolvem no contexto histórico e social da queda do império inca e da instalação da colônia espanhola.

Fontes nitrogenadas com diferentes taxas de degradação ruminal na alimentação de ovinos

OpenAIRE

Clayton Quirino Mendes

2010-01-01

Foram realizados três experimentos com o objetivo de determinar os efeitos do aumento da PDR da ração por meio do uso de fontes nitrogenadas com diferentes taxas de degradação ruminal. Exp. 1: 28 cordeiros da raça Santa Inês foram utilizados para avaliação do desempenho, características da carcaça e da carne e parâmetros sanguíneos. Além disso, foi avaliada a capacidade do SRNS em predizer o CMS e o GMD dos animais. O farelo de soja foi substituído pela uréia nos teores de 0,7%; 1,4% e 2,1% d...

Produção e qualidade de frutos de laranjeira 'Pêra' em função de fontes e doses de boro Yield and quality of 'Pera' sweet orange in effect of boron source and doses

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Isabela Rodrigues Bologna

2006-08-01

Full Text Available O presente trabalho objetivou estudar o efeito de fontes e doses de boro aplicadas no solo na produção e qualidade dos frutos de laranjeira 'Pêra'. Os tratamentos constituíram-se de cinco fontes de boro (ulexita-pó, colemanita, ulexita-granulada, termofosfato magnesiano com boro e ácido bórico e quatro doses (1; 2; 3 e 4 kg ha-1, em delineamento inteiramente casualizado e esquema fatorial 5 x 4, em quatro repetições. A produção da cultura não sofreu influência das fontes e doses de boro, 11 meses após a aplicação dos tratamentos. Nos atributos tecnológicos, não foram observados efeitos significativos nos parâmetros: ratio, teor de sólidos solúveis e ºBrix. Houve redução do rendimento de suco com o aumento da dose de boro aplicada para todas as fontes testadas. O maior e o menor diâmetro de fruto foram obtidos, respectivamente, com o uso da fonte mais solúvel (ácido bórico e menos solúvel (colemanita, não havendo influência dos tratamentos na espessura de casca.The aim of this research was to evaluate effects of boron sources and doses in the yield and quality of 'Pera' sweet orange. The treatments were five boron sources (ulexite-powder, colemanite, ulexite-grain, magnesian thermo phosphate with boron and acid boric and four boron doses (1, 2, 3 and 4 kg ha-1. Experimental design was completely randomized in factorial 5 x 4, with four replications. Eleven months after treatments application crop yield was not influenced by boron source and doses. Fruit technological attributes as ratio, soluble solid contents and ºBrix were not different. Orange juice production decreased with boron dose increasing for all evaluated sources. The largest fruit diameter was found under the most soluble source (boric acid while the smallest fruit diameter was obtained under the less soluble source (colemanite. Treatment influence was not observed to fruit skin thickness.

A New Control Method for a Bi-Directional Phase-Shift-Controlled DC-DC Converter with an Extended Load Range

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Wenzheng Xu

2017-10-01

Full Text Available Phase-shifted converters are practically important to provide high conversion efficiencies through soft-switching techniques. However, the limitation on a resonant inductor current in the converters often leads to a non-fulfillment of the requirement of minimum load current. This paper presents a new power electronics control technique to enable the dual features of bi-directional power flow and an extended load range for soft-switching in phase-shift-controlled DC-DC converters. The proposed technique utilizes two identical full bridge converters and inverters in conjunction with a new control logic for gate-driving signals to facilitate both Zero Current Switching (ZCS and Zero Voltage Switching (ZVS in a single phase-shift-controlled DC-DC converter. The additional ZCS is designed for light load conditions at which the minimum load current cannot be attained. The bi-directional phase-shift-controlled DC-DC converter can implement the function of synchronous rectification. Its fast dynamic response allows for quick energy recovery during the regenerative braking of traction systems in electrified trains.

Shared neuroanatomical substrates of impaired phonological working memory across reading disability and autism.

Science.gov (United States)

Lu, Chunming; Qi, Zhenghan; Harris, Adrianne; Weil, Lisa Wisman; Han, Michelle; Halverson, Kelly; Perrachione, Tyler K; Kjelgaard, Margaret; Wexler, Kenneth; Tager-Flusberg, Helen; Gabrieli, John D E

2016-03-01

Individuals with reading disability or individuals with autism spectrum disorder (ASD) are characterized, respectively, by their difficulties in reading or social communication, but both groups often have impaired phonological working memory (PWM). It is not known whether the impaired PWM reflects distinct or shared neuroanatomical abnormalities in these two diagnostic groups. White-matter structural connectivity via diffusion weighted imaging was examined in sixty-four children, ages 5-17 years, with reading disability, ASD, or typical development (TD), who were matched in age, gender, intelligence, and diffusion data quality. Children with reading disability and children with ASD exhibited reduced PWM compared to children with TD. The two diagnostic groups showed altered white-matter microstructure in the temporo-parietal portion of the left arcuate fasciculus (AF) and in the temporo-occipital portion of the right inferior longitudinal fasciculus (ILF), as indexed by reduced fractional anisotropy and increased radial diffusivity. Moreover, the structural integrity of the right ILF was positively correlated with PWM ability in the two diagnostic groups, but not in the TD group. These findings suggest that impaired PWM is transdiagnostically associated with shared neuroanatomical abnormalities in ASD and reading disability. Microstructural characteristics in left AF and right ILF may play important roles in the development of PWM. The right ILF may support a compensatory mechanism for children with impaired PWM.

2000 days of SMOS at the Barcelona Expert Centre: a tribute to the work of Jordi Font

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Antonio Turiel

2016-09-01

Full Text Available Soil Moisture and Ocean Salinity (SMOS is the first satellite mission capable of measuring sea surface salinity and soil moisture from space. Its novel instrument (the L-band radiometer MIRAS has required the development of new algorithms to process SMOS data, a challenging task due to many processing issues and the difficulties inherent in a new technology. In the wake of SMOS, a new community of users has grown, requesting new products and applications, and extending the interest in this novel brand of satellite services. This paper reviews the role played by the Barcelona Expert Centre under the direction of Jordi Font, SMOS co-principal investigator. The main scientific activities and achievements and the future directions are discussed, highlighting the importance of the oceanographic applications of the mission.

Fonte eólica de energia: aspectos de inserção, tecnologia e competitividade

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Elbia Melo

2013-01-01

Full Text Available A energia eólica tem experimentado um exponencial e virtuoso crescimento no Brasil. De 2009 a 2012, nos seis leilões em que a fonte eólica participou, foram contratados 7 GW em novos projetos representando mais de 25 bilhões de reais em investimentos. A trajetória da fonte eólica que deverá chegar em 2017 com 8,5 GW de capacidade instalada teve início com o Programa de Incentivo às Fontes Alternativas de Energia Elétrica (Proinfa. Lançado em 2004 e baseado em um estruturado modelo de financiamento e políticas regionais, o Proinfa foi responsável pela contratação de 1.422,9 MW, por meio de preços subsidiados. O ano 2012 foi marcado pela comemoração da inserção de 2 GW de potência instalada de energia eólica no sistema elétrico nacional, de forma que o Brasil encerra o ano de 2012 com 2,5 GW de potência eólica instalada e 2% de participação na matriz elétrica brasileira. Porém, também foi um ano de grandes desafios e dificuldades para a fonte eólica, o que culminou em uma relativa desaceleração para esta indústria. Inclusive com a realização de apenas um leilão que teve a menor demanda contratada de todos os leilões de energia nova já realizados. A reduzida contratação também resultou em preços muito baixos, uma vez que a competição foi muito acirrada, a oferta foi 28 vezes superior a demanda, de forma que o certame foi encerrado com preços médios de R$ 90,00 por MWh. A indústria eólica está passando por uma fase crucial de consolidação, apresentando estágio ainda imaturo, a existência de onze fabricantes, cada um com capacidade média de produção de 500 MW por ano de equipamentos, não necessariamente determina uma oferta de 5.000 MW de máquinas. É certo que o ano 2012, sob o aspecto da contratação, não foi um período muito animador, visto que a economia cresceu menos do que o esperado e para 2013 espera-se a retomada do crescimento do PIB nacional, em torno de 4%, e a retomada nos n

Implantação de Íons de Nitrogênio em PMMA Através de uma Fonte Kaufman

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Cristian Padilha Fontoura

2017-08-01

Full Text Available A modificação de superfícies é uma técnica que a engenharia tem feito uso há muito tempo, para melhoria de propriedades em materiais. O poli metil-metacrilato (PMMA, por ser um material de constante uso em aplicações biomédicas, exige que sua superfície apresente características favoráveis à adesão celular e compatibilidade com tecidos. Os polímeros, de uma maneira geral, quando submetidos a tratamentos em plasma, tendem a formar grupos funcionais que alteram propriedades ópticas, químicas, físicas e de biocompatibilidade. Em função disso, este trabalho propôs realizar a funcionalização de substratos de PMMA através da fonte de íons Kaufman. Amostras de PMMA foram submetidas ao feixe de íons de nitrogênio gerado pela fonte Kaufman, em diversas condições. A caracterização foi feita pelas técnicas de GD-OES, FTIR e EDS. Ficou comprovado, através do perfil de concentração de nitrogênio obtido por GD-OES, que a quantidade de nitrogênio na superfície aumenta gradativamente com o tempo de implantação e a potência. Outro indício foi a análise em FTIR, que mostrou presença de aminas nas faixas entre 1654-655 cm-1 e 3300-3700 cm-1. A análise em EDS, porém, comprovou também a presença de ferro e cromo, agentes citotóxicos, que precisam ser eliminados para a continuidade dos trabalhos.

Three-Level Inverters with Common-Mode Voltage Cancellation Based on Synchronous Pulsewidth Modulation

DEFF Research Database (Denmark)

Oleschuk, Valentin; Blaabjerg, Frede

2002-01-01

A novel method of direct synchronous pulse-width modulation (PWM) is disseminated to three-level voltage source inverters with control algorithms with elimination of the common-mode voltages in three-phase drive systems with PWM. It provides smooth pulses-ratio changing and a quarter-wave symmetry...... of the voltage waveforms during the whole control range including overmodulation. Continuous, discontinuous and "direct-direct" schemes of synchronous PWM with both algebraic and trigonometric control functions have been analysed and compared. Simulations give the behaviour of the proposed methods and show some...... advantages of synchronous PWM in comparison with asynchronous at low ratios between the switching frequency and fundamental frequency....

Synchronised Voltage Space Vector Modulation for Three-level Inverters with Common-mode Voltage Elimination

DEFF Research Database (Denmark)

Oleschuk, Valentin; Blaabjerg, Frede

2002-01-01

A novel method of direct synchronous pulse-width modulation (PWM) is disseminated to three-level voltage source inverters with control algorithms with elimination of the common-mode voltages in three-phase drive systems with PWM. It provides smooth pulses-ratio changing and a quarter-wave symmetry...... of the voltage waveforms during the whole control range including overmodulation. Continuous, discontinuous and "direct-direct" schemes of synchronous PWM with both algebraic and trigonometric control functions have been analysed and compared. Simulations give the behaviour of the proposed methods and show some...... advantages of synchronous PWM in comparison with asynchronous at low ratios between the switching frequency and fundamental frequency....

Fontes para a história dos 50 anos do Ministério da Saúde

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Lima Ana Luce Girão Soares de

2003-01-01

Full Text Available Este trabalho e um levantamento das fontes sobre a história do Ministério da Saúde existentes no acervo da Casa de Oswaldo Cruz/Fiocruz. Utilizamos como marcos cronológicos os cinqüenta anos anteriores à lei 1.920, de 25 de julho de 1953, que separou a saúde e a educação em pastas autônomas. Nesse período foram lançadas as bases que fundamentariam as políticas públicas de saúde e informariam a estrutura do futuro ministério. Privilegiou-se aqui também a ação dos sanitaristas e intelectuais que figuraram como atores importantes no processo de construção ideológica não só das estruturas de Estado, como também das próprias políticas.

A current view of copybooks (the font in the Czech Republic and in selected countries of Europe

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Bartošová Iva Košek

2016-01-01

Full Text Available The purpose of the present research of mixed design, i.e. qualitative and quantitative nature is to draw a comparison of the most widely used copybooks – textbooks in the Czech Republic based on adapted evaluation criteria originally presented by [1] - content, graphic design, format and adequacy of writing tasks and range etc. and subsequently focus the research on an analysis of similar workbooks – copybooks (including the used font in selected European countries. The proposed research project is a follow-up of a research project realized in 2014 and designed to identify the publishing houses having the greatest numbers of sales of textbooks for 1st -3rd grades of primary schools as well as the reasons for which teachers choose the materials from a particular publishing house in the Czech Republic.

Higher moments method for generalized Pareto distribution in flood frequency analysis

Science.gov (United States)

Zhou, C. R.; Chen, Y. F.; Huang, Q.; Gu, S. H.

2017-08-01

The generalized Pareto distribution (GPD) has proven to be the ideal distribution in fitting with the peak over threshold series in flood frequency analysis. Several moments-based estimators are applied to estimating the parameters of GPD. Higher linear moments (LH moments) and higher probability weighted moments (HPWM) are the linear combinations of Probability Weighted Moments (PWM). In this study, the relationship between them will be explored. A series of statistical experiments and a case study are used to compare their performances. The results show that if the same PWM are used in LH moments and HPWM methods, the parameter estimated by these two methods is unbiased. Particularly, when the same PWM are used, the PWM method (or the HPWM method when the order equals 0) shows identical results in parameter estimation with the linear Moments (L-Moments) method. Additionally, this phenomenon is significant when r ≥ 1 that the same order PWM are used in HPWM and LH moments method.

Resíduo de Curtumes como Fonte de Nitrogênio para Trigo e Arroz em Sucessão

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Lívia Cristina Coelho

2015-10-01

Full Text Available RESUMO O processo de estabilização necessário para o curtimento das peles, na indústria coureira, gera grande quantidade de resíduo sólido colagênico com elevado potencial poluidor. Esse resíduo contém elevado teor de nitrogênio, o que confere ao resíduo potencial para uso agrícola. Para avaliar a viabilidade da aplicação de rejeito da indústria do couro, como fonte nitrogenada para as culturas do trigo e arroz de sequeiro, foi implantado um experimento em casa de vegetação com cinco doses de N provenientes do colágeno (0, 225, 450, 675 e 900 mg kg-1 e três tratamentos adicionais (controle, ureia e ureia reposta no segundo cultivo. A aplicação de até 675 mg kg-1 de N via colágeno propiciou produção de matéria seca de plantas de trigo similar à aplicação de N mineral e maior massa de grãos de trigo em todas as doses estudadas (14 a 41 % superiores à aplicação de N mineral. Como fonte residual, a aplicação do colágeno proporcionou níveis de N no solo suficientes para obter massa de grãos de arroz nas doses mais elevadas (acima de 675 mg kg-1de N via colágeno, sem que os teores de Cr foliares sejam considerados tóxicos. O colágeno pode ser boa alternativa para a implantação da cultura do arroz após a colheita de trigo, sem prejuízos de produtividade e necessidade de reposição de fertilizantes nitrogenados, se aplicado na dose 675 mg kg-1 de N fornecido via colágeno.

FONTES DE ADUBOS ORGÂNICOS NA PRODUÇÃO DE MUDAS DE PITAIA

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Felipe Pereira Dal'col

2016-10-01

Full Text Available A pitaia (Hylocereus undatus é uma frutífera exótica que vem se popularizando perante os produtores brasileiros. Com isso, verificou-se a utilização de duas fontes de esterco animal, como tratamentos compostos de solo de barranco + esterco de curral (2:1, solo de barranco  + esterco suíno curtido (2:1 e solo de barranco, onde todos foram enriquecidos com a dose de 2Kg m-3 de superfosfato simples. O experimento foi realizado no Setor de Viveiricultura do Ifes- Campus Santa Teresa. Utilizou-se o delineamento inteiramente casualizado (DIC, com 5 repetições. Transcorridos 75 dias do plantio as mudas foram avaliadas considerando-se a parte aérea e o sistema radicular. Observou-se efeito significativo nos tratamentos aplicados para a produção de mudas de pitaia. Os tratamentos contendo esterco bovino e suíno se apresentaram superiores com relação ao número de brotos, altura de plantas e matéria seca de brotos, o que os indica  proporcionar o melhor desenvolvimento de mudas de pitaia, em virtude dos acréscimos nutricionais e nas características físicas do substrato.

Fontes nitrogenadas e uso de Sacharomyces cerevisiae em dietas à base de cana-de-açúcar para novilhos: consumo, digestibilidade, balanço nitrogenado e parâmetros ruminais

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Pereira Elzânia Sales

2001-01-01

Full Text Available O objetivo do presente estudo foi avaliar os efeitos das fontes nitrogenadas e o uso de Sacharomyces cerevisiae em dietas à base de cana-de-açúcar sobre os consumos e as digestibilidades aparentes totais e parciais de matéria seca (MS, matéria orgânica (MO, proteína bruta (PB, extrato etéreo (EE, carboidratos totais (CHO, fibra em detergente neutro (FDN e carboidratos não-estruturais (CNE, o balanço nitrogenado e os parâmetros ruminais. Foram utilizados quatro novilhos Holandês-Zebu, fistulados no rúmen e abomaso, alimentados com quatro rações à base de cana-de-açúcar, constituídas de duas fontes nitrogenadas (uréia ou cama de frango combinadas com dois níveis de Sacharomyces cerevisiae (0 e 10 g/dia. Utilizou-se delineamento em quadrado latino 4 x 4. A fibra em detergente neutro indigestível (FDNi foi utilizada como indicador, para determinar as digestibilidades aparentes totais e parciais. Os consumos de MS, MO, EE, CT e CNE não foram influenciados pelas fontes nitrogenadas e pela utilização de Sacharomyces cerevisiae. Os consumos de PB e FDN foram maiores para as dietas suplementadas com cama de frango. Os coeficientes de digestibilidades totais de PB e EE foram maiores para as dietas constituídas de uréia. As digestibilidades aparentes totais de MS, MO, CT e FDN não foram influenciadas pelas fontes nitrogenadas e pela utilização de Sacharomyces cerevisiae. O pH do líquido ruminal decresceu linearmente para as dietas suplementadas com uréia e apresentou comportamento quadrático, quando estas dietas foram combinadas com Sacharomyces cerevisiae. As concentrações de amônia no líquido ruminal apresentaram comportamento quadrático, estimando-se valores máximos de 16,90; 26,12; 18,48; e 14,40 mg/100 mL para os tratamentos constituídos de cana-de-açúcar e uréia; cana-de-açúcar, uréia e Sacharomyces cerevisiae; cana-de-açúcar e cama de frango; e cana-de-açúcar, cama de frango e Sacharomyces cerevisiae

Relationships between mountain pine and climate in the French Pyrenees (Font-Romeu studied using the radiodensitometrical method

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Rolland, Cristian

1994-12-01

Full Text Available A radiodensitometrical study was carried out on 46 Pinus uncinata (Ramond in Font-Romeu (French Pyrenees. Correlation functions with monthly climatical data were calculated using separately the ring-widths, the earlywood and the latewood densities. The Mountain Pine shows narrow rings (1.5 mm and a high sensitivity to climate (M.S. = 0.221, but it does not seem to suffer from drought despite the dryness of the climate (788 mm rainfall per year. This species is more sensitive to temperature than to precipitation, since temperature governs latewood formation. A hot spring and a mild autumn with maximum temperatures above threshold levels will extend the growing period. A warm autumn also increases the latewood density, whereas cold nights during the previous year's autumn are unfavourable to growth because they may affect the cambium and bud initiations.

[es] Se ha llevado a cabo un trabajo densitométrico sobre 46 Pinus uncinata (Ramond en Font-Romeu (Cerdaña francesa. Las funciones de correlación con el clima han sido calculadas sucesivamente con el espesor de los anillos de crecimiento, la densidad de la madera temprana y de la madera tardía. Esta especie produce anillos de crecimiento delgados (1.5 mm y presenta una elevada sensibilidad con el clima (S.M. = 0.221 pero no parece afectada por la falta de lluvia aunque el clima es más xérico (788 mm/ año. La madera tardía parece muy sensible a las temperaturas. Una primavera cálida ejerce un efecto favorable y un otoño suave con temperaturas máximas superiores a límites críticos permite continuar su desarollo. De la misma manera un otoño caliente aumenta la densidad de la madera tardía aunque las noches frías durante el otoño precedente son desfavorables para el crecimiento porque pueden afectar al Inicio de las yemas y del cambium.
[fr] Une étude radiodensitométrique de46 Pinus uncinata (Ramond a été réalisée à Font-Romeu (Pyrénées Françaises. Les

Latest Performance Results from the FONT5 Intra-train Beam Position and Angle Feedback System at ATF2

CERN Document Server

Christian, G B; Bett, D R; Blaskovic Kraljevic, N; Burrows, P N; Davis, M R; Gerbershagen, A; Perry, C; Constance, B; Resta-Lopez, J

2012-01-01

A prototype Interaction Point beam-based feedback system for future electron-positron colliders, such as the International Linear Collider, has been designed and tested on the extraction line of the KEK Accelerator Test Facility (ATF). The FONT5 intra-train feedback system aims to stabilize the beam orbit by correcting both the position and angle jitter in the vertical plane on bunch-tobunch time scales, providing micron-level stability at the entrance to the ATF2 final-focus system. The system comprises three stripline beam position monitors (BPMs) and two stripline kickers, custom low-latency analogue front-end BPM processors, a custom FPGA-based digital processing board with fast ADCs, and custom kickerdrive amplifiers. The latest results from beam tests at ATF2 will be presented, including the system latency and correction performance.

Reasoned versus reactive prediction of behaviour: a meta-analysis of the prototype willingness model.

Science.gov (United States)

Todd, Jemma; Kothe, Emily; Mullan, Barbara; Monds, Lauren

2016-01-01

The prototype willingness model (PWM) was designed to extend expectancy-value models of health behaviour by also including a heuristic, or social reactive pathway, to better explain health-risk behaviours in adolescents and young adults. The pathway includes prototype, i.e., images of a typical person who engages in a behaviour, and willingness to engage in behaviour. The current study describes a meta-analysis of predictive research using the PWM and explores the role of the heuristic pathway and intentions in predicting behaviour. Eighty-one studies met inclusion criteria. Overall, the PWM was supported and explained 20.5% of the variance in behaviour. Willingness explained 4.9% of the variance in behaviour over and above intention, although intention tended to be more strongly related to behaviour than was willingness. The strength of the PWM relationships tended to vary according to the behaviour being tested, with alcohol consumption being the behaviour best explained. Age was also an important moderator, and, as expected, PWM behaviour was best accounted for within adolescent samples. Results were heterogeneous even after moderators were taken into consideration. This meta-analysis provides support for the PWM and may be used to inform future interventions that can be tailored for at-risk populations.

Influência das fontes e granulometria do calcário calcítico sobre a densidade, resistência e composição mineral da tíbia de poedeiras comerciais - DOI: 10.4025/actascianimsci.v27i1.1238 Influence of limestone source and particle size on the density, strength and mineral content of laying hens' tibia bone - DOI: 10.4025/actascianimsci.v27i1.1238

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Maria Auxiliadora Andrade

2005-03-01

Full Text Available O objetivo desse trabalho foi verificar a influência de diferentes fontes de calcário calcítico com diferentes faixas granulométricas (fino, médio, pedrisco sobre a densidade, a resistência e composição mineral de tíbias de poedeiras comerciais em três idades. Foram utilizadas 192 poedeiras da linhagem Isa Babcock B 300, com 33 semanas de idade, distribuídas em um delineamento em blocos casualizados com 6 tratamentos, 2 blocos e 4 repetições de 8 aves cada. O experimento durou 38 semanas a foi dividido em 9 ciclos de 28 dias. Os tratamentos consistiram em 1 = calcário fino Fonte 1; 2 = médio Fonte 1; 3 = pedrisco Fonte 1; 4 = calcário fino Fonte 2; 5 = pedrisco Fonte 2; 6 = calcário pedrisco Fonte 3. Não foi observado efeito negativo nas características ósseas avaliadas para as diferentes fontes e granulometria de calcário testadas, porém nota-se maior força de resistência óssea quando utilizado calcário pedriscoThis experiment was carried out to evaluate the effects of different sources of limestone with different particle sizes (fine, medium and large on bone quality of laying hens. 192 Isa Babcock B 300 hens - 33 weeks of age were allotted in a randomized block design with a total of 6 treatments, 2 blocks and 4 replicates of 8 hens each. The feeding trial lasted 38 weeks. The six experimental diets were: 1 - fine limestone Source 1; 2 - medium limestone Source 1; 3 - larger limestone Source 1; 4 - fine limestone Source 2; 5 - larger limestone Source 2; 6 - larger limestone Source 3. No negative effects on layer bone characteristics were observed, but better strength bone when larger particles were used

O trabalho de tradutor como fonte para constituição de base de dados

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Bibiana Teixeira de Almeida

2005-12-01

Full Text Available O presente artigo visa a relatar o trabalho desenvolvido durante o projeto de iniciação científica “O trabalho de tradutor como fonte para a constituição de base de dados”. Através da documentação, recuperação e digitalização do glossário pessoal e de parte do acervo de livros de traduções do falecido tradutor público Gustavo Lohnefink, o referido projeto de pesquisa teve por objetivo principal constituir uma base de dados digital de termos técnicos para o par de línguas alemão – português e colocá-lo à disposição de tradutores(as. Para tanto, foi necessário o desenvolvimento de uma metodologia específica, aqui relatada, que poderá servir como ponto de partida para o tratamento e a recuperação de acervos semelhantes.

Ácidos graxos trans: implicações nutricionais e fontes na dieta Trans fatty acids: nutritional implications and sources in the diet

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Clayton Antunes Martin

2004-09-01

Full Text Available Este artigo revisa as principais fontes de ácidos graxos trans na dieta e as implicações nutricionais da ingestão elevada destes isômeros. São apresentados resumidamente os métodos analíticos utilizados na identificação e quantificação dos ácidos graxos trans, sendo abordados as suas vantagens e desvantagens. Os alimentos que empregam gordura parcialmente hidrogenada na sua produção, são fontes importantes de isômeros trans na dieta da maior parte da população em países industrializados. Este estudo compara os níveis de ácidos graxos trans em gorduras hidrogenadas, margarinas e batatas frita, analisados em diversos países, incluindo o Brasil. Esta avaliação indica a presença de níveis elevados de isômeros trans em alimentos produzidos no Brasil.This article review the main sources of trans fatty acids in the diet and nutritional implications of the high intake of these isomers. Analytical methods for the identification and quantification of trans fatty acids are presented briefly with regard to advantages and drawbacks of each method. Foods make with partially hidrogenated fats are important sources of trans isomers in the diets of most people in industrialized countries. It is made a comparison between levels of trans fatty acids in shortenings, margarines and potato chips evaluated in Brazil and in other countries. High levels of trans isomers are noted in Brazilian foods.

Analysis and development of fourth order LCLC resonant based capacitor charging power supply for pulse power applications.

Science.gov (United States)

Naresh, P; Hitesh, C; Patel, A; Kolge, T; Sharma, Archana; Mittal, K C

2013-08-01

A fourth order (LCLC) resonant converter based capacitor charging power supply (CCPS) is designed and developed for pulse power applications. Resonant converters are preferred t utilize soft switching techniques such as zero current switching (ZCS) and zero voltage switching (ZVS). An attempt has been made to overcome the disadvantages in 2nd and 3rd resonant converter topologies; hence a fourth order resonant topology is used in this paper for CCPS application. In this paper a novel fourth order LCLC based resonant converter has been explored and mathematical analysis carried out to calculate load independent constant current. This topology provides load independent constant current at switching frequency (fs) equal to resonant frequency (fr). By changing switching condition (on time and dead time) this topology has both soft switching techniques such as ZCS and ZVS for better switching action to improve the converter efficiency. This novel technique has special features such as low peak current through switches, DC blocking for transformer, utilizing transformer leakage inductance as resonant component. A prototype has been developed and tested successfully to charge a 100 μF capacitor to 200 V.

HARMONIC ANALYSIS OF SVPWM INVERTER USING MULTIPLE-PULSES METHOD

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Mehmet YUMURTACI

2009-01-01

Full Text Available Space Vector Modulation (SVM technique is a popular and an important PWM technique for three phases voltage source inverter in the control of Induction Motor. In this study harmonic analysis of Space Vector PWM (SVPWM is investigated using multiple-pulses method. Multiple-Pulses method calculates the Fourier coefficients of individual positive and negative pulses of the output PWM waveform and adds them together using the principle of superposition to calculate the Fourier coefficients of the all PWM output signal. Harmonic magnitudes can be calculated directly by this method without linearization, using look-up tables or Bessel functions. In this study, the results obtained in the application of SVPWM for values of variable parameters are compared with the results obtained with the multiple-pulses method.

Fontes alternativas e doses de nitrogênio no milho safrinha em sucessão à soja Sidedressing nitrogen alternative sources and rates on out-of-season corn after soybean

Directory of Open Access Journals (Sweden)

Rogério Peres Soratto

2010-12-01

Full Text Available A produtividade do milho safrinha pode ser aumentada com a adubação nitrogenada em cobertura mesmo quando cultivado em sucessão à soja. No entanto, existem inconsistências dos resultados especialmente quanto às fontes e doses a serem empregadas nessa modalidade de cultivo. Com o objetivo de avaliar o efeito de fontes e doses de nitrogênio em cobertura no milho safrinha, cultivado após soja no sistema plantio direto, conduziu-se o experimento em um Latossolo Vermelho distrófico, em Chapadão do Céu (GO. O delineamento experimental foi o de blocos ao acaso, em esquema fatorial 4 x 4, com quatro repetições. Os tratamentos foram constituídos pela combinação de quatro fontes (uréia, sulfato de amônio, uréia extrusada com produtos amiláceos (Amiréia® 180S e sulfonitrato de amônio com inibidor de nitrificação (Entec® 26 e quatro doses de nitrogênio (0; 30; 60 e 120 kg ha-1. A interação fonte x dose não foi significativa para nenhuma das variáveis avaliadas. A aplicação de nitrogênio na forma de entec proporcionou maiores teores de nitrogênio na folha do milho safrinha que o sulfato de amônio e a amiréia. A produtividade de grãos do milho safrinha foi maior quando o nitrogênio em cobertura foi fornecido na forma de sulfato de amônio, em comparação com a amiréia. A aplicação de nitrogênio em cobertura aumentou os teores de nitrogênio e enxofre na folha, altura da planta, diâmetro do colmo, número de espigas por planta e grãos por espiga, massa de 1.000 grãos e produtividade de grãos do milho safrinha, em sucessão à soja, independentemente da fonte utilizada.Out-of-season corn yield can be increased by nitrogen sidedressing fertilization even when sowed after soybean harvest. However, there is result inconsistency especially as to nitrogen sources and rates for corn in the cropping system. In order to evaluate the effect of sources and rates of sidedressed nitrogen application on out-of-season corn

Generalized model of a bidirectional DC-DC converter

Science.gov (United States)

Hinov, Nikolay; Arnaudov, Dimitar; Penev, Dimitar

2017-12-01

The following paperwork presents models of bidirectional converters. A classic bidirectional converter and a new bidirectional circuit based on a ZCS resonant converter are investigated and compared. The developed models of these converters allow comparison between their characteristics showing their advantages and disadvantages. The models allow precise models of energy storage elements to be implemented as well, which is useful for examination of energy storage systems.

Inventory and categorization of radioactive sources in the CDTN, Minas Gerais, Brazil; Inventario e categorizacao de fontes radioativas no CDTN, Minas Gerais, Brasil

Energy Technology Data Exchange (ETDEWEB)

Silva, Fabio; Tello, Cledola Cassia Oliveira de, E-mail: silvaf@cdtn.b, E-mail: tellocc@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2011-10-26

Radioactive sources have wide application, in the medicine, industry, agriculture and in the research centers. After the use those sources are considered radioactive wastes and conducted to the CNEN research institutes, that have the legal responsibility to receive and control. The safe attribution of wasted sources is essential for minimizing the possibility oc accident occurrence. The data of the stored sources in the CDTN are included and processed in the data bank SISFONT - Sistema de Informacoes sobre Fontes Seladas Fora de Uso, but this system does not allow their categorization. For that, a efficient, precise and easy interaction categorization system was developed

Disque denúncia como fonte de informações para análises criminais na Região Metropolitana de Salvador 2006-2011

OpenAIRE

Portella, Daniel Deivson Alves

2013-01-01

Introdução: O tráfico de drogas pode ser considerado como um dos fatores determinantes para o aumento de homicídios nas metrópoles e nas regiões metropolitanas. A grande frequência de crimes contribuiu para que a população passasse a fazer denúncias anônimas sobre os fatos criminosos através do programa Disque Denúncia,implantado na Bahia desde 2005. Objetivos: Analisar o Disque Denúncia como fonte de informações para análises criminais na Região Metropolitana de Salvador (RMS) de 2006-2011 e...

Registros de hóspedes como fonte de pesquisa para a História

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Liara Fagundes Echart

2016-03-01

Full Text Available O presente trabalho busca analisar os livros de registros e movimentação de hóspedes do Grande Hotel de Pelotas. O Grande Hotel foi inaugurado em 1928 e permaneceu em funcionamento até o ano de 2002. Atualmente no prédio, doado à Universidade Federal de Pelotas, encontra-se as dependências do Curso Superior de Tecnologia em Hotelaria. A metodologia utilizada consistiu na identificação e análise dos livros de registros e de movimentação de hóspedes do Grande Hotel de Pelotas. Concomitantemente ao processo de pesquisa documental, realizou-se a pesquisa bibliográfica acerca da temática proposta, a fim de realizar o questionamento sobre a relevância do assunto. Ao todo foram localizados 18 exemplares de livros de registros e movimentação de hóspedes, compreendendo o período entre meados de 1959 até 2002, sendo esta última data marcada pelo encerramento das atividades hoteleiras do Grande Hotel de Pelotas. Os livros de registros e movimentação de hóspedes do Grande Hotel mostraram-se uma importante fonte histórica para o estudo da hotelaria em Pelotas.

Líquens da área de reserva do Parque Estadual das Fontes do Ipiranga

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Lúcia Yoko Nagaoka

1989-01-01

Full Text Available O objetivo deste trabalho é verificar a alteração da flora liquenica do parque neste século através da comparação de material de herbário com aquele encontrado atualmente na área de reserva do parque. Apenas 9 das 38 espécies levantadas em herbário puderam ser encontradas atualmente, sendo que a maioria apresenta sinais evidentes de perda de vigor e poderão desaparecer em pouco tempo. Pseudoparmelia texana (Tuck.Hale aparece nas coletas posteriores a 1973 sendo agora abundante sobre troncos nas áreas mais expostas.The Parque Estadual das Fontes do Ipiranga is within the urban area of the São Paulo city (São Paulo state, Brazil and through the years has received air effluents from a smelter of the vicinity. The aim of this work is to verify the change of the park's lichen flora by comparison of the extant flora with that held at the SP herbarium. Only 9 species can be found nowadays. 7 of them are very rare and from youngless populations. Parmotrema tinctorum (Nyl. Hale is rare. Pseudoparmelia texana (Tuck.Hale appears in the collections after 1973 and is now abundant, covering great trunk extensions at exposed places.

Potencialidade de uso de fontes alternativas de água para fins não potáveis em uma unidade residencial

OpenAIRE

Peters, Madelon Rebelo

2006-01-01

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pos-Graduação em Engenharia Ambiental. O uso racional da água compreende o controle de desperdícios e uma re-educação de hábitos e costumes. Esta re-educação está associada ao uso de fontes alternativas como, por exemplo, os efluentes tratados gerados na própria residência e a captação de águas pluviais, em substituição a água potável para fins que não seja o consumo humano. O uso de águas de c...

Experimental determination of mechanical parameters in sensorless ...

Indian Academy of Sciences (India)

V S S PAVAN KUMAR HARI

pulse width modulation (PWM) selected. The three-phase .... and the simulation and experimental results are presented. ... between 0 and Ts due to the process of PWM. Hence, the .... MATLAB SIMULINK with the machine parameters in.

Fontes proteicas alternativas oriundas da cadeia produtiva do biodiesel para alimentação de ruminantes

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F.F. Medeiros

2015-04-01

Full Text Available Objetivou-se avaliar a degradação e a produção de gás de diferentes fontes proteicas geradas na cadeia produtiva do biodiesel em substituição à silagem de milho. Os tratamentos foram: coprodutos de Gossyypium hirsutum, Ricinus communis, Moringa oleifera, Jatropha curcas, Helianthus annus. Os produtos foram analisados mediante a técnica semiautomática de produção de gases in vitro. O coproduto da moringa apresentou maior taxa de degradação, quando comparado aos demais alimentos, porém apresentou baixa produção de gás e se tornou mais eficiente, sendo, portanto, indicado como o melhor nível (27,06% de substituição à silagem de milho. O coproduto da mamona e o do algodão produziram a maior quantidade de gás em 48h de incubação. Todos os coprodutos estudados podem ser utilizados na dieta de ruminantes como alimento proteico até 30% de substituição à silagem de milho.

Font attributes based text steganographic algorithm (FATS) for communicating images. A nuclear power plant perspective

Energy Technology Data Exchange (ETDEWEB)

Krishnan, R. Bala [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Computer Division; Thandra, Prasanth Kumar; Murty, S.A.V. Satya [Indira Gandhi Centre for Atomic Research, Kalpakkam (India); Thiyagarajan, P. [Central Univ. of Tamil Nadu, Thiruvarur (India). Dept. of Computer Science

2017-03-15

Today even sensitive organizations like nuclear power plants are connected to the internet. As information security is of utmost priority to such organizations, achieving the same is a challenging task while using the public network like the internet. Though cryptography could be used to enhance the information security, it cannot hide its own presence from the attackers. This drawback lead security professionals to look for an alternate technique like steganography. Steganography hides the secret information, stealthily, inside another innocent looking cover medium like text, image, audio and video. Considering these, this paper proposes a novel text steganographic algorithm that embeds images as codes in the font attributes such as color, character spacing and kerning. The procedure of representing an image as codes makes the proposed method independent from the resolution of the image. Experiments were conducted by embedding diverse categories of images. A comparison with the best existing method depicted that the embedding capacity attained by the proposed method is higher at 1.59-bits/character, which suits best for low bandwidth environments. Various security aspects of the proposed method have also been discussed.

Font attributes based text steganographic algorithm (FATS) for communicating images. A nuclear power plant perspective

International Nuclear Information System (INIS)

Krishnan, R. Bala; Thiyagarajan, P.

2017-01-01

Today even sensitive organizations like nuclear power plants are connected to the internet. As information security is of utmost priority to such organizations, achieving the same is a challenging task while using the public network like the internet. Though cryptography could be used to enhance the information security, it cannot hide its own presence from the attackers. This drawback lead security professionals to look for an alternate technique like steganography. Steganography hides the secret information, stealthily, inside another innocent looking cover medium like text, image, audio and video. Considering these, this paper proposes a novel text steganographic algorithm that embeds images as codes in the font attributes such as color, character spacing and kerning. The procedure of representing an image as codes makes the proposed method independent from the resolution of the image. Experiments were conducted by embedding diverse categories of images. A comparison with the best existing method depicted that the embedding capacity attained by the proposed method is higher at 1.59-bits/character, which suits best for low bandwidth environments. Various security aspects of the proposed method have also been discussed.

Pulsewidth modulated DC-to-DC power conversion circuits, dynamics, and control designs

CERN Document Server

Choi, Byungcho

2013-01-01

This is the definitive reference for anyone involved in pulsewidth modulated DC-to-DC power conversion Pulsewidth Modulated DC-to-DC Power Conversion: Circuits, Dynamics, and Control Designs provides engineers, researchers, and students in the power electronics field with comprehensive and complete guidance to understanding pulsewidth modulated (PWM) DC-to-DC power converters. Presented in three parts, the book addresses the circuitry and operation of PWM DC-to-DC converters and their dynamic characteristics, along with in-depth discussions of control design of PWM DC-to

INCERTEZAS NA REPRESENTAÇÃO DA SALUBRIDADE AMBIENTAL ATRAVÉS DE INDICADORES OBTIDOS COM BASE EM DIFERENTES FONTES DE INFORMAÇÃO. ESTUDO DE CASO: BACIA DO RIACHO REGINALDO EM MACEIÓ, ALAGOAS

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José Aparecido da Silva Gama

2016-12-01

Full Text Available Indicadores têm sido utilizados para representar a qualidade e abrangência na prestação de serviços de saneamento básico. Entretanto, diferentes fontes de informação abordam de forma distinta cada um dos componentes do saneamento. O IBGE, por exemplo, mostra como os usuários acessam (ou usam determinado serviço, enquanto o prestador do serviço traz sua abrangência e disponibilidade. Assim, a disponibilidade de determinado serviço de saneamento (abastecimento de água, por exemplo não garante que todos os usuários fazem uso (ou se beneficiam dele e da mesma forma. Com este trabalho, apresenta-se uma metodologia para composição de um Indicador de Salubridade Ambiental (ISA/Maceió, considerando informações relacionadas à prestação de serviços de saneamento básico provenientes de duas fontes: IBGE (censo 2010 e prestadores municipais de serviços de saneamento. O trabalho resultou em: (i adaptação de metodologias existentes de cálculo do ISA, considerando informações locais disponíveis; (ii a composição e (iii o mapeamento do ISA. A metodologia foi aplicada em estudo de caso na bacia do riacho Reginaldo em Maceió/AL, e os resultados mostraram que a fonte de informação utilizada pode gerar distorções importantes de interpretação do ISA. De maneira geral, a bacia estudada apresenta grande variação nas condições de salubridade ambiental, com setores censitários variando de condição de salubridade muito baixa a alta, considerando a realidade local.

Quantitative 1H MR spectroscopy of the brain in patients with congestive heart failure before and after cardiac transplantation

International Nuclear Information System (INIS)

Lim, Soo Mee; Lee, Ho Kyu; Choi, Choong Gon; Lim, Tae Hwan; Lee, Jung Hee

1999-01-01

To evaluate the effects of cardiac transplantation on the brain in patients with congestive heart failure (CHF), using quantitative 1 H MR spectroscopy ( 1 H-MRS). Ten patients with CHF underwent MRI and quantitative 1 H-MRS before and 1-2 and 4-9 months after cardiac transplantation. MR spectra were obtained from parietal white matter (PWM) and occipital gray matter (OGM) using PROBE (PROton Brain Exam). Changes in MR signal intensity were evaluated, and the cerebral metabolic concentrations in PWM and OGM were compared. For comparative purposes, 20 normal volunteers were included. No abnormal MR signal intensity was seen in the brain before or after cardiac transplantation. Changes in cerebral metabolic concentrations were observed on 1 H-MRS; concentrations of creatine (Cr) in PWM, and of N-acetylacepartate (NAA), Cr and myo-Inositol(mI) in OGM were significantly lower before transplantation. After successful transplantation, Cr levels returned to their normal range in PWM and OGM, while a slightly increase choline (Cho) level was observed in PWM. Cerebral hypoperfusion in CHF can be evaluated using 1 H-MRS. MRS may play a substantial role in monitoring the effect of cardiac transplantation

T-lymphocyte dependency of B-lymphocyte blastogenic response to phytomitogens

International Nuclear Information System (INIS)

Han, T.; Dadey, B.

1978-01-01

Human peripheral blood T and B lymphocytes were separated by a method based on the stable rosette formation of T lymphocytes with neuraminidase-treated sheep erythrocytes, followed by centrifugation over a Ficoll-Hypaque gradient. Monocytes were isolated from the T-depleted B lymphocyte preparation by allowing the monocytes to ingest iron particles and by subsequent centrifugation over a Ficoll-Hypaque gradient. The T lymphocytes responded extremely well to PHA and very well to PWM, while the B lymphocytes were unresponsive to either PHA or PWM. However, when the B lymphocytes were cultured together with irradiated autologous or allogeneic T lymphocytes (1 : 1,1:2 or 1 : 4 ratio), both PHA and PWM became mitogenic to B lymphocytes. Irradiated T lymphocytes alone did not respond to either PHA or PWM, indicating that the 3 H-thymidine incorporation seen in the mixed-cell culture was due to the activation of unirradiated B lymphocytes. The B lymphocytes failed to respond to these phytomitogens in the presence of lower concentrations of irradiated T lymphocytes. The monocytes were found to be incapable of helping the B lymphocytes to respond to PHA or PWM. (author)

Quantitative {sup 1}H MR spectroscopy of the brain in patients with congestive heart failure before and after cardiac transplantation

Energy Technology Data Exchange (ETDEWEB)

Lim, Soo Mee; Lee, Ho Kyu; Choi, Choong Gon; Lim, Tae Hwan [Asan Medical Center, Ulsan Univ. College of Medicine, Ulsan (Korea, Republic of); Lee, Jung Hee [Asan Institute for Life Sciences, Seoul (Korea, Republic of)

1999-12-01

To evaluate the effects of cardiac transplantation on the brain in patients with congestive heart failure (CHF), using quantitative {sup 1}H MR spectroscopy ({sup 1}H-MRS). Ten patients with CHF underwent MRI and quantitative {sup 1}H-MRS before and 1-2 and 4-9 months after cardiac transplantation. MR spectra were obtained from parietal white matter (PWM) and occipital gray matter (OGM) using PROBE (PROton Brain Exam). Changes in MR signal intensity were evaluated, and the cerebral metabolic concentrations in PWM and OGM were compared. For comparative purposes, 20 normal volunteers were included. No abnormal MR signal intensity was seen in the brain before or after cardiac transplantation. Changes in cerebral metabolic concentrations were observed on {sup 1}H-MRS; concentrations of creatine (Cr) in PWM, and of N-acetylacepartate (NAA), Cr and myo-Inositol(mI) in OGM were significantly lower before transplantation. After successful transplantation, Cr levels returned to their normal range in PWM and OGM, while a slightly increase choline (Cho) level was observed in PWM. Cerebral hypoperfusion in CHF can be evaluated using {sup 1}H-MRS. MRS may play a substantial role in monitoring the effect of cardiac transplantation.

Quasi-Resonant Full-Wave Zero-Current Switching Buck Converter Design, Simulation and Application

OpenAIRE

Yanik, G.; Isen, E.

2015-01-01

—This paper presents a full wave quasi-resonant zerocurrent switching buck converter design, simulation and application. The converter control uses with zero-current switching (ZCS) technique to decrease the switching losses. Comparing to conventional buck converter, resonant buck converter includes a resonant tank equipped with resonant inductor and capacitor. The converter is analyzed in mathematical for each subintervals. Depending on the desired input and output electrical quantities, con...

Pulse-width modulated DC-DC power converters

CERN Document Server

Kazimierczuk, Marian K

2008-01-01

This book studies switch-mode power supplies (SMPS) in great detail. This type of converter changes an unregulated DC voltage into a high-frequency pulse-width modulated (PWM) voltage controlled by varying the duty cycle, then changes the PWM AC voltage to a regulated DC voltage at a high efficiency by rectification and filtering. Used to supply electronic circuits, this converter saves energy and space in the overall system. With concept-orientated explanations, this book offers state-of-the-art SMPS technology and promotes an understanding of the principle operations of PWM converters,

The theory and implementation of a high quality pulse width modulated waveform synthesiser applicable to voltage FED inverters

Science.gov (United States)

Lower, Kim Nigel

1985-03-01

Modulation processes associated with the digital implementation of pulse width modulation (PWM) switching strategies were examined. A software package based on a portable turnkey structure is presented. Waveform synthesizer implementation techniques are reviewed. A three phase PWM waveform synthesizer for voltage fed inverters was realized. It is based on a constant carrier frequency of 18 kHz and a regular sample, single edge, asynchronous PWM switching scheme. With high carrier frequencies, it is possible to utilize simple switching strategies and as a consequence, many advantages are highlighted, emphasizing the importance to industrial and office markets.

Cargas polínicas de abelhas polinizadoras de Byrsonima chrysophylla Kunth. (Malpighiaceae: fidelidade e fontes alternativas de recursos florais Pollen loads of pollinator bees of Byrsonima chrysophylla Kunth. (Malpighiaceae: fidelity and alternative sources of flower resources

Directory of Open Access Journals (Sweden)

Éville Karina Maciel Delgado Ribeiro

2008-03-01

Full Text Available Byrsonima chrysophylla, conhecida popularmente como murici pitanga, é uma espécie arbustiva que ocorre em restinga. Dentre seus visitantes, além de abelhas da tribo Centridini, também se encontram com freqüência abelhas Xylocopini. Para verificação das espécies vegetais utilizadas pelas abelhas visitantes mais freqüentes, cargas polínicas de suas pernas posteriores (n = 5, bem como de ninhos naturais de Centris caxiensis (n = 7 foram analisados através de acetólise. Durante toda a floração, Byrsonima chrysophylla foi a principal fonte de pólen utilizada por suas abelhas visitantes. Comolia lythrarioides e Myrcia obtusa foram fontes secundárias de pólen, Mouriri guianensis foi fonte secundária de óleo e pólen, enquanto Anacardium microcarpum, Cuphea tenella, Matayba discolor e Phthirusa pyrifolia mostraram-se importantes fontes de néctar durante esse período, sendo o pólen detectado nas amostras, provavelmente aderido ao corpo das abelhas durante a coleta de néctar. Os resultados demonstram que as abelhas visitantes não misturaram os recursos polínicos durante o vôo para a coleta de pólen, apresentando fidelidade às flores de Byrsonima chrysophylla.Byrsonima chrysophylla, known as "murici pitanga", is a shrubby species occurring in 'restinga'. Among its visitors, bees of the Centridini tribe as well as Xylocopini bees are frequently found. To detect which plant species have been used by the most frequent visitors, pollen loads from the back legs (n = 5 and also from natural nests of Centris caxiensis (n = 7 were treated by acetolysis. During flowering of Byrsonima chrysophylla, this plant species was the main pollen source used by bees. Comolia lythrarioides and Myrcia sylvatica were secondary pollen sources, Mouriri guianensis was a secondary oil and pollen source, while Anacardium microcarpum, Cuphea tenella, Matayba discolor and Phthirusa pyrifolia were important nectar sources at this time. The pollen detected in

Três mulheres no nazismo: Reflexões sobre as fontes do comportamento moral

Directory of Open Access Journals (Sweden)

Maria Claudia Coelho

2009-07-01

Full Text Available Este trabalho discute as fontes do comportamento moral. Seu ponto de partida é a crítica feita à sociologia da moral durkheimiana por Zygmunt Bauman, que problematiza os pressupostos da origem social da moral e sua natureza coercitiva. Bauman contrapropõe, com base nas obras de Hannah Arendt e Emmanuel Lévinas, uma concepção de moralidade cujo núcleo é a responsabilidade para com o outro. A discussão é empreendida com base em três filmes que retratam cada qual a trajetória de uma mulher durante o nazismo: Traudl Junge, Sophie Scholl e Leni Riefenstahl. O eixo da análise é o modo como responsabilidade, culpa e consciência se entrelaçam em suas trajetórias. This article discusses the sources of moral behaviour. Its point of departure is Zygmunt Bauman’s criticism of the Durkheimian sociology of morality, challenging the assumptions of the social origin of morality and its coercive nature. Drawing on Hannah Arendt’s and Emmanuel Levinas’ works, Bauman counter-proposes a concept of morality based on responsibility toward each other. The discussion is then developed in relation to three fi lms that portray, each in their own way, the experience of a woman during the Nazi regime: Traudl Junge, Sophie Scholl and Leni Riefenstahl. The analysis is centred on how responsibility, guilt and conscience intertwine in the course of those lives.

Produtividade da cultura da melancia em função de fontes e doses de potássio Yield of watermelon fruits as a function of sources and doses of potassium

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Arthur Bernardes Cecílio Filho

2004-06-01

Full Text Available Foram conduzidos dois experimentos em propriedades rurais próximas à cidade de Borborema - SP, nos períodos de outubro a dezembro de 2001 e de fevereiro a abril de 2002, com o objetivo de avaliar a produtividade de melancia (Citrullus lanatus (Thumb. Matsum. & Nakai, híbrido Tide, em função de fontes e doses de potássio. O delineamento experimental utilizado foi o de blocos casualizados completos, em esquema fatorial 3 x 4, com três repetições, sendo utilizadas as fontes: cloreto KCl, nitrato (KNO3 e sulfato de potássio (K2SO4 e as doses: 50; 100; 200 e 300 kg de K2O ha-1. Foram avaliados o peso médio de fruto, o número de frutos e produção por planta e produtividade. O maior número de frutos por planta estimado foi obtido nas doses de 190 e 300 kg K2O ha-1, respectivamente, nas fontes KNO3 e KCl. Não houve diferença significativa entre as doses para K2SO4. Para o peso médio de fruto, houve diferença significativa entre as fontes apenas no cultivo de fevereiro a abril de 2002, quando o KCl proporcionou maior peso. A maior produção por planta foi obtida com K2SO4, seguido por KNO3 e KCl. Entretanto, as doses de potássio para as máximas produtividades foram de 132, 193 e 205 kg K2O ha-1, respectivamente, para as fontes K2SO4, KNO3 e KCl. O plantio de outubro a dezembro de 2001 proporcionou maior peso médio, produção de frutos por planta e produtividade, ao passo que o maior número de frutos por planta foi obtido no cultivo de fevereiro a abril de 2002.Two field experiments were conducted in Borborema, State of São Paulo, from periods of October to December of the 2001 and February to April of 2002, with the objective of evaluate the yield of watermelon (Tide hybrid (Citrullus lanatus (Thumb. Matsum. & Nakai in function of sources and doses of potassium. The experimental design was a randomized complete block, with three replications, in a 3 x 4 factorial scheme, being evaluated sources: potassium chloride, nitrate and

Agronomic efficiency of potassium fertilization in lettuce fertilized with alternative nutrient sources Eficiência agronômica da adubação potássica na alface adubada com fontes alternativas de nutrientes

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Douglas Ramos Guelfi-Silva

2013-06-01

Full Text Available The aim of this study was to evaluate the effect of alternative sources of nutrients on the nutrition, yield and efficiency of potassium fertilization in lettuce. The experiment was carried out in a greenhouse, using 3.7 kg pots filled with a dystrophic red-yellow Latosol of medium texture. The experimental design was randomized, with treatments divided into a 4 x 6 factorial: four doses of potassium (0; 200; 400; 600 kg ha-1 K2O and six alternative sources of nutrients (breccia, ultramafic, biotite schist, phlogopite, and mining and Chapada by-products, with four replications. Content and accumulation were determined for potassium (K, copper (Cu, zinc (Zn and nickel (Ni in the lettuce shoots, and from these data two indices were calculated for the efficiency of potassium as a fertilizer. The application of increasing values of alternative sources of nutrients promoted improvements in nutrition and increases in lettuce yield. The efficiency of potassium fertilization decreased with the increase in values of potassium taken from alternative nutrient sources, with the mining by-products and the ultramafic being superior to the other sources. Crushed silicate rocks and mining by-products can therefore both be used as fertilizer in organic and conventional production systems.O objetivo desse estudo foi avaliar o efeito da aplicação de fontes alternativas de nutrientes na nutrição, produção e eficiência da adubação potássica na alface. O experimento foi conduzido em casa de vegetação, em vasos com 3,7 kg preenchidos com um Latossolo Vermelho Amarelo distrófico de textura média. O delineamento experimental foi inteiramente casualizado e os tratamentos foram distribuídos em arranjo fatorial 4 x 6, sendo quatro doses de potássio (0; 200; 400; 600 kg ha-1 de K2O e seis fontes alternativas de nutrientes (brecha, ultramáfica, biotita xisto, flogopitito, subproduto de mineração e subproduto de chapada, com quatro repetições. Foram

Consumo e conhecimento sobre alimentos fontes de lipídeos por professores de escola técnica em saúde = Consumption and knowledge on source of lipid foods by health technical school teachers

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Anastácio, Gislaine

2009-01-01

Full Text Available Objetivo: Investigar o hábito de consumo e conhecimentos sobre alimentos fontes de lipídios, entre os professores de uma Escola Técnica em Saúde da Rede Estadual de Ensino em Porto Alegre, RS. Materiais e Métodos: Estudo transversal, realizado com professores de ambos os sexos, através de um questionário de frequência de consumo alimentar contendo nove grupos alimentares, predominantemente fontes de lipídeos e, outro questionário, visando o reconhecimento sobre gorduras alimentares e os efeitos na saúde humana. A análise estatística foi descritiva e com auxílio do software Excel. Resultados: 39 professores participaram da pesquisa, destes 28 mulheres e média de 43±11anos de idade. O consumo de azeite de oliva diariamente foi citado por 38% dos participantes e leite desnatado em 41%. Margarina é habitual para cerca de 25% deles e mais da metade do grupo nega uso de maionese e manteiga. Referem consumo frequente, de 1 a 3 vezes por semana, para pizza (54%, carne bovina sem gordura aparente (49% e ave sem pele (70%. Os embutidos, frituras e preparações à milanesa são de consumo eventual para a maioria, inclusive as oleaginosas. Conclusão: Os professores demonstram adequados conhecimentos sobre a importância de selecionar alimentos que são fontes de gordura e sobre seus efeitos no organismo. Eles também exercem boas escolhas desses alimentos, no seu dia-a-dia. Esclarecimentos adicionais em Nutrição poderão contribuir ainda mais à prática saudável e à difusão dessas informações

Fontes energéticas vegetais para juvenis de jundiá e carpa

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V. Corrêia

2012-06-01

Full Text Available Para avaliar o desempenho, o metabolismo e a composição corporal de juvenis de jundiá (Rhamdia quelen e de carpa húngara (Cyprinus carpio alimentados com fontes energéticas vegetais, foi conduzido experimento de 60 dias. Três dietas compostas por aveia descascada, farelo de arroz desengordurado estabilizado (FADE ou por farelo de trigo e milho (dieta-controle foram ofertadas três vezes ao dia a 360 juvenis de jundiá (5,59±0,06g ou de carpa húngara (5,82±0,14g distribuídos em 18 tanques (280L, totalizando nove tanques por espécie. Não foram observadas diferenças significativas no desempenho das espécies estudadas. Em relação aos parâmetros metabólicos, as menores concentrações séricas de colesterol total no jundiá foram verificadas nas dietas com aveia (214,49mg/dL e FADE (216,3mg/dL, enquanto para a carpa húngara as menores concentrações observadas foram nos peixes alimentados com FADE (222,54mg/dL. Quanto à composição centesimal, os valores de gordura no filé foram menores nos jundiás dos tratamentos controle (3,76% e aveia (3,95%. A inclusão de aveia proporcionou menor deposição de gordura corporal em ambas as espécies. Conclui-se que 20% de aveia descascada ou de farelo de arroz desengordurado podem ser incluídos na dieta de juvenis de jundiá e de carpa húngara sem prejuízos para o crescimento.

Estudo do efeito da incorporação de plastificante de fonte renovável em compostos de PVC

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Derval dos Santos Rosa

2013-01-01

Full Text Available O acúmulo de resíduos poliméricos tem crescido nos últimos anos e os subsolos dos lixões já estão saturados com resíduos plásticos. Isso possivelmente se deve à elevada produção de resíduos sólidos de plásticos (cerca de 25 mil t/dia em 2008, segundo a Lei de Resíduos. Em vista disso, este trabalho apresenta uma análise comparativa do estudo do potencial de (biodegradação de compostos de PVC utilizando um plastificante de origem vegetal renovável (PFR com estrutura de éster de milho com massa molar 296,5 g.mol- 1 e dois plastificantes sintéticos, ftalato de dioctila (DOP e adipato de dioctila (DOA, buscando inovar na obtenção de um composto de PVC com um plastificante de fonte renovável. Os resultados de FTIR evidenciaram maior interação do PFR com a resina de PVC para o teor de 30 phr, e para o teor de 40 phr observou-se que os plastificantes DOP e PFR apresentaram os mesmos valores de variação da banda atática. Já os ensaios mecânicos reforçaram os resultados de FTIR com maior compatibilidade para as composições contendo PFR. Uma maior estabilidade térmica no composto de PVC foi observada por TGA para a amostra contendo 40 phr de DOA, o que foi confirmado por RMN, e para a amostra com PFR nos teores de 30 e 40 phr. Por fim, uma perda significativa de massa foi observada nos ensaios de resistência à extração por solvente para os compostos contendo DOA, sendo que a amostra com 30 phr mostrou menor valor de extração. A biodegradação em solo simulado mostrou maior perda de massa para as amostras plastificadas com DOA (40phr e PFR (40phr. Isso indica que é viável usar plastificante de fonte renovável nos compostos de PVC, devido à compatibilidade deste com esta resina.

Revision of Fontes & Garnier's model for the initial 14C content of dissolved inorganic carbon used in groundwater dating

Science.gov (United States)

Han, Liang-Feng; Plummer, Niel

2013-01-01

The widely applied model for groundwater dating using 14C proposed by Fontes and Garnier (F&G) (Fontes and Garnier, 1979) estimates the initial 14C content in waters from carbonate-rock aquifers affected by isotopic exchange. Usually, the model of F&G is applied in one of two ways: (1) using a single 13C fractionation factor of gaseous CO2 with respect to a solid carbonate mineral, εg/s, regardless of whether the carbon isotopic exchange is controlled by soil CO2 in the unsaturated zone, or by solid carbonate mineral in the saturated zone; or (2) using different fractionation factors if the exchange process is dominated by soil CO2 gas as opposed to solid carbonate mineral (typically calcite). An analysis of the F&G model shows an inadequate conceptualization, resulting in underestimation of the initial 14C values (14C0) for groundwater systems that have undergone isotopic exchange. The degree to which the 14C0 is underestimated increases with the extent of isotopic exchange. Examples show that in extreme cases, the error in calculated adjusted initial 14C values can be more than 20% modern carbon (pmc). A model is derived that revises the mass balance method of F&G by using a modified model conceptualization. The derivation yields a “global” model both for carbon isotopic exchange dominated by gaseous CO2 in the unsaturated zone, and for carbon isotopic exchange dominated by solid carbonate mineral in the saturated zone. However, the revised model requires different parameters for exchange dominated by gaseous CO2 as opposed to exchange dominated by solid carbonate minerals. The revised model for exchange dominated by gaseous CO2 is shown to be identical to the model of Mook (Mook, 1976). For groundwater systems where exchange occurs both in the unsaturated zone and saturated zone, the revised model can still be used; however, 14C0 will be slightly underestimated. Finally, in carbonate systems undergoing complex geochemical reactions, such as oxidation of

A Cell-to-Cell Equalizer Based on Three-Resonant-State Switched-Capacitor Converters for Series-Connected Battery Strings

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Yunlong Shang

2017-02-01

Full Text Available Due to the low cost, small size, and ease of control, the switched-capacitor (SC battery equalizers are promising among active balancing methods. However, it is difficult to achieve the full cell equalization for the SC equalizers due to the inevitable voltage drops across Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET switches. Moreover, when the voltage gap among cells is larger, the balancing efficiency is lower, while the balancing speed becomes slower as the voltage gap gets smaller. In order to soften these downsides, this paper proposes a cell-to-cell battery equalization topology with zero-current switching (ZCS and zero-voltage gap (ZVG among cells based on three-resonant-state SC converters. Based on the conventional inductor-capacitor (LC converter, an additional resonant path is built to release the charge of the capacitor into the inductor in each switching cycle, which lays the foundations for obtaining ZVG among cells, improves the balancing efficiency at a large voltage gap, and increases the balancing speed at a small voltage gap. A four-lithium-ion-cell prototype is applied to validate the theoretical analysis. Experiment results demonstrate that the proposed topology has good equalization performances with fast equalization, ZCS, and ZVG among cells.

Effect of different methods of pulse width modulation on power losses in an induction motor

Science.gov (United States)

Gulyaev, Alexander; Fokin, Dmitrii; Shuharev, Sergey; Ten, Evgenii

2017-10-01

We consider the calculation of modulation power losses in a system “induction motor-inverter” for various pulse width modulation (PWM) methods of the supply voltage. Presented values of modulation power losses are the result of modeling a system “DC link - two-level three-phase voltage inverter - induction motor - load”. In this study the power losses in a system “induction motor - inverter” are computed, as well as losses caused by higher harmonics of PWM supply voltage, followed by definition of active power consumed by the DC link for a specified value mechanical power on the induction motor shaft. Mechanical power was determined by the rotation speed and the torque on the motor shaft in various quasi-sinusoidal supply voltage PWM modes. These calculations reveal the best coefficient of performance (COP) in a system of a variable frequency drive (VFD) with independent voltage inverter controlled by induction motor PWM.

Levantamento das principais fontes de desperdício de unidades assistenciais de um hospital universitário

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Valéria Castilho

2011-12-01

Full Text Available Este estudo teve como principais objetivos levantar os diferentes tipos de desperdício, suas causas e sugestões para eliminá-los, segundo a opinião de profissionais de enfermagem e médicos atuantes em unidades de Clínica Médica, Clínica Cirúrgica, Pediatria, Alojamento Conjunto e Berçário; e estimar o custo da principal fonte de desperdício nessas unidades. Trata-se de um estudo descritivo, exploratório, com abordagem quantitativa realizado no Hospital Universitário da Universidade de São Paulo. A amostra foi constituída por 189 profissionais de enfermagem e médicos. O desperdício relacionado aos materiais (36% foi o mais apontado por todas as categorias profissionais seguido pelo desperdício de estrutura física (27%. Os materiais desperdiçados mais citados foram os medicamentos, pacotes de curativo, papel sulfite e dispositivos de infusão. O custo do desperdício anual com materiais nas unidades estudadas pode girar em torno de R$ 479.262,86.

Produtividade, acúmulo de nitrato e estado nutricional de cultivares de alface, em hidroponia, em função de fontes de nutrientes

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Fernandes Adriano Alves

2002-01-01

Full Text Available Foram avaliados a produtividade, acúmulo de nitrato e estado nutricional das cultivares de alface Regina, Babá de Verão e Grandes Lagos em cultivo hidropônico. O experimento foi conduzido no outono, de 25/03 a 20/05/99 em estufa da UFV. Foram avaliados dois conjuntos de fontes de nutrientes para compor as soluções nutritivas de crescimento vegetativo, que continham: 13,6; 1,0; 7,0; 4,48; e 2,5 mmol L-1 de N, P, K, Ca e Mg, respectivamente. O enxofre foi fornecido na concentração de 3,5 ou 2,5 mmol L-1 e os micronutrientes nas concentrações de 45; 32; 46; 2; 0,9; e 0,2 mmol L-1 para Fe, Mn, B, Zn, Cu e Mo, respectivamente. A solução 1 forneceu 21,9% de N na forma amoniacal, e a solução 2, 100% de N na forma de nitrato. As fontes de P empregadas foram fosfato monoamônico e fosfato monopotássico para as soluções 1 e 2 respectivamente, sendo que esta variação implicou no uso de diferentes quantidades de KCl nas soluções, o que proporcionou concentrações diferentes de Cl, apresentando-se 6,76 e 2,18 mmol L-1 para as soluções 1 e 2, respectivamente. O cultivo foi feito em recipiente plástico com 8L de capacidade, contendo três plantas. Os recipientes foram arranjados de modo que se obtivesse espaçamento de 0,22 m entre plantas. O delineamento experimental utilizado foi blocos ao acaso com seis repetições, em arranjo fatorial 2 x 3 (soluções x cultivares. Cada parcela foi constituída por três plantas. Foram avaliados o peso da matéria fresca da parte aérea, folhas, raízes e caule, número de folhas, comprimento do caule, porcentagem de matéria seca das folhas e estado nutricional da planta. A cv. Regina produziu 233 g planta-1 e a cv. Babá de Verão 193 g planta-1. Os resultados obtidos para a cultivar Grandes Lagos não foram satisfatórios nas condições do experimento. A solução 1 proporcionou menores concentrações de nitrato para as cultivares Grandes Lagos (1082 mg kg-1 de matéria fresca e Regina (1092

Grupo Padre Luiz Gonzaga - Bragança-PA: arquivos, método e fontes da história da educação da Amazônia, no século XX

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Maria José Aviz do Rosário

2015-08-01

Full Text Available O trabalho objetiva apresentar análise das primeiras fontes históricas sobre o Grupo Escolar Padre Luiz Gonzaga, de Bragança - PA. Pautou - se em dois propósitos, recuperação e disponibilização da história e memória dessa instituição escolar, de formação do povo bragantino, no Século XX e contribuição ao registro de fontes históricas das instituições escolares da Região Amazônica. A metodologia constituiu-se do levantamento e análise de fontes históricas documentais, orais e iconográficas. Na análise procurou - se discutir o conceito e a importância de método do trabalho com fontes históricas, articulando o conhecimento mais geral sobre a formação educacional paraense e brasileira, fazendo-se aproximações de como foram forjadas as propostas educacionais no contexto bragantino por meio do grupo. A primeira etapa dedicou-se aos documentos escritos, Projeto Político Pedagógico e cadernetas escolares e a iconografia composta de retratos com os quais pode – se compor as primeiras cenas da educação do grupo. Em seguida ouviu-se a segunda diretora, a segunda secretária e as professoras da primeira geração e segunda geração. A análise aponta o grupo como instrumento de articulação da proposta de expansão da educação primária nos anos de 1960, já que sua criação, em 1962, atendia a reivindicação da nova população da cidade, composta de agricultores e pescadores dos campos, das praias e colônias que empurrados para os arrabaldes da cidade, exigiam do poder público, escola para seus filhos. A escola também era tida como modelo pedagógico em que prevaleciam o respeito e a disciplina; o amor à pátria incutido pelo cântico do Hino Nacional; a preocupação em não deixar criança sem estudar, por meio do famoso “jeito”; a influência da igreja católica; pela catequese de responsabilidade da paróquia, cujo ápice era realização da primeira comunhão; a distribuição de merenda escolar

Hybrid Modulation Scheme for Cascaded H-Bridge Inverter Cells ...

African Journals Online (AJOL)

This work proposes a switching technique for cascaded H-Bridge (CHB) cells. Single carrier Sinusoidal PWM (SCSPWM) scheme is employed in the generation of the gating signals. A sequential switching and base PWM circulation schemes are presented for this fundamental cascaded multilevel inverter topology.

Efeito da suplementação com pupunha como fonte de vitamina A em dieta: estudo em ratos

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Lucia K.O. Yuyama

1996-02-01

Full Text Available Foi estudado o efeito da suplementação com pupunha (Bactris gasipaes H.B.K., polpa cozida e transformada em farinha, como fonte de vitamina A, em dieta regional de Manaus, AM,Brasil, por meio do ensaio biológico com ratos. A metodologia utilizada foi da depleção dos animais em zinco e vitamina A, seguida da repleção com a dieta regional (DR, DR + pupunha, DR + vitamina A e dieta controle (DC. A dieta foi elaborada para famílias com rendimentos inferiores a dois salários-mínimos. Foram utilizadas ratas albinas adultas pós-parto, cada qual com 6 filhotes machos, que receberam ração à base de caseína lavada com EDTA a 1%, sem adição de Zn e vitamina A, por 25 dias, com a finalidade de obtenção de animais recém-desmamados deficientes nestes dois nutrientes. O período de repleção dos animais, recém-desmamados, foi de 30 dias e o delineamento foi inteiramente casualizado com 4 tratamentos de 8 animais cada. A suplementação efetuada seguiu as recomendações do "Committee on Laboratory Animal Diets". Os parâmetros empregados para a avaliação da utilização de vitamina A foram as concentrações de vitamina A no fígado e plasma e o crescimento dos animais. Ao final do experimento, observou-se que os animais que consumiram a ração à base da dieta regional de Manaus, suplementada com pupunha e vitamina A, apresentaram, respectivamente, concentração significativamente maior de vitamina A no fígado, 43,3 ± 6,5 µg/g e 42,0 ± 4,3 µg/g em relação à dieta regional, 5,5 ± 1,1 µg/g (p<0,05. A quantidade de zinco presente na dieta regional de Manaus, 10,7 mg diários, foi biodisponível quando avaliada pela concentração de zinco nos fêmures. Os resultados sugerem que existe necessidade de suplementação da dieta regional de Manaus com vitamina A para a manutenção das reservas hepáticas, podendo, para tanto, ser utilizada a fonte natural da pupunha.

A Cost-Effective Design and Analysis of Full Bridge LLC Resonant Converter

OpenAIRE

Kaibalya Prasad Panda; Sreyasee Rout

2016-01-01

LLC (Inductor-inductor-capacitor) resonant converter has lots of advantages over other type of resonant converters which include high efficiency, more reliable and have high power density. This paper presents the design and analysis of a full bridge LLC resonant converter. In addition to the operational principle, the ZVS and ZCS conditions are also explained with the DC characteristics. Simulation of the LLC resonant converter is performed in MATLAB/ Simulink and the practical prototype setu...

Development of high-performance solar LED lighting system

KAUST Repository

Huang, B.J.; Wu, M.S.; Hsu, P.C.; Chen, J.W.; Chen, K.Y.

2010-01-01

The present study developed a high-performance charge/discharge controller for stand-alone solar LED lighting system by incorporating an nMPPO system design, a PWM battery charge control, and a PWM battery discharge control to directly drive the LED. The MPPT controller can then be removed from the stand-alone solar system and the charged capacity of the battery increases 9.7%. For LED driven by PWM current directly from battery, a reliability test for the light decay of LED lamps was performed continuously for 13,200 h. It has shown that the light decay of PWM-driven LED is the same as that of constant-current driven LED. The switching energy loss of the MOSFET in the PWM battery discharge control is less than 1%. Three solar-powered LED lighting systems (18 W, 100 W and 150 W LED) were designed and built. The long-term outdoor field test results have shown that the system performance is satisfactory with the control system developed in the present study. The loss of load probability for the 18 W solar LED system is 14.1% in winter and zero in summer. For the 100 W solar LED system, the loss of load probability is 3.6% in spring. © 2009 Elsevier Ltd. All rights reserved.

Spelling errors among children with ADHD symptoms: the role of working memory.

Science.gov (United States)

Re, Anna Maria; Mirandola, Chiara; Esposito, Stefania Sara; Capodieci, Agnese

2014-09-01

Research has shown that children with attention deficit/hyperactivity disorder (ADHD) may present a series of academic difficulties, including spelling errors. Given that correct spelling is supported by the phonological component of working memory (PWM), the present study examined whether or not the spelling difficulties of children with ADHD are emphasized when children's PWM is overloaded. A group of 19 children with ADHD symptoms (between 8 and 11 years of age), and a group of typically developing children matched for age, schooling, gender, rated intellectual abilities, and socioeconomic status, were administered two dictation texts: one under typical conditions and one under a pre-load condition that required the participants to remember a series of digits while writing. The results confirmed that children with ADHD symptoms have spelling difficulties, produce a higher percentages of errors compared to the control group children, and that these difficulties are enhanced under a higher load of PWM. An analysis of errors showed that this holds true, especially for phonological errors. The increased errors in the PWM condition was not due to a tradeoff between working memory and writing, as children with ADHD also performed more poorly in the PWM task. The theoretical and practical implications are discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Development of high-performance solar LED lighting system

International Nuclear Information System (INIS)

Huang, B.J.; Wu, M.S.; Hsu, P.C.; Chen, J.W.; Chen, K.Y.

2010-01-01

The present study developed a high-performance charge/discharge controller for stand-alone solar LED lighting system by incorporating an nMPPO system design, a PWM battery charge control, and a PWM battery discharge control to directly drive the LED. The MPPT controller can then be removed from the stand-alone solar system and the charged capacity of the battery increases 9.7%. For LED driven by PWM current directly from battery, a reliability test for the light decay of LED lamps was performed continuously for 13,200 h. It has shown that the light decay of PWM-driven LED is the same as that of constant-current driven LED. The switching energy loss of the MOSFET in the PWM battery discharge control is less than 1%. Three solar-powered LED lighting systems (18 W, 100 W and 150 W LED) were designed and built. The long-term outdoor field test results have shown that the system performance is satisfactory with the control system developed in the present study. The loss of load probability for the 18 W solar LED system is 14.1% in winter and zero in summer. For the 100 W solar LED system, the loss of load probability is 3.6% in spring.

Development of high-performance solar LED lighting system

KAUST Repository

Huang, B.J.

2010-08-01

The present study developed a high-performance charge/discharge controller for stand-alone solar LED lighting system by incorporating an nMPPO system design, a PWM battery charge control, and a PWM battery discharge control to directly drive the LED. The MPPT controller can then be removed from the stand-alone solar system and the charged capacity of the battery increases 9.7%. For LED driven by PWM current directly from battery, a reliability test for the light decay of LED lamps was performed continuously for 13,200 h. It has shown that the light decay of PWM-driven LED is the same as that of constant-current driven LED. The switching energy loss of the MOSFET in the PWM battery discharge control is less than 1%. Three solar-powered LED lighting systems (18 W, 100 W and 150 W LED) were designed and built. The long-term outdoor field test results have shown that the system performance is satisfactory with the control system developed in the present study. The loss of load probability for the 18 W solar LED system is 14.1% in winter and zero in summer. For the 100 W solar LED system, the loss of load probability is 3.6% in spring. © 2009 Elsevier Ltd. All rights reserved.

Desempenho e rendimento de carcaça de bovinos mestiços alimentados com diferentes volumosos e fontes protéicas Performance and carcass dressing in crossbreed steers fed different forage and nitrogen sources

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Fernanda Macitelli

2007-12-01

Full Text Available Quarenta bovinos machos, com 30 meses de idade e 371 kg, foram distribuídos em um delineamento em blocos casualizado com esquema fatorial 3 x 3, para avaliar o desempenho e rendimento de carcaça quando alimentados com diferentes fontes protéicas (Amiferm, uréia e farelo de soja e volumosos (pastagem de capim-braquiária, cana-de-açúcar e silagem de milho. As dietas foram balanceadas para conterem níveis semelhantes de EM e PB. A interação volumoso x fonte de N não foi significativa para nenhum dos parâmetros estudados. O ganho de peso vivo diário (GPV/dia dos animais alimentados com cana-de-açúcar (0,83 kg não diferiu dos mantidos em pastagem (0,82 kg, mas ambos foram menores que dos animais alimentados com silagem de milho (1,09 kg. As diferentes fontes de N proporcionaram GPV/dia semelhantes, com valores de 0,94; 0,83 e 0,97 kg, para os animais que receberam uréia, Amiferm e farelo de soja, respectivamente. As dietas contendo farelo de soja proporcionaram maior ganho de carcaça diário (0,57 kg em relação ao uso de Amiferm, não diferindo da uréia (0,55 kg. Não houve diferença entre volumosos e fontes nitrogenadas para rendimento de carcaça, rendimento de carcaça do corpo vazio, rendimento de carcaça do ganho de peso e espessura de gordura, com média de 51,03%, 54,49%, 60,10% e 8,5 mm, respectivamente. O uso de Amiferm proporcionou ganhos de peso e rendimento de carcaça semelhantes às demais fontes protéicas.Forty steers averaging 371 kg BW were allotted to a randomized block design, in a factorial scheme 3 x 3 to evaluate the effect of feeding different protein sources (urea, amiferm, soybean meal and forage (sugar cane, corn silage and pasture Bracharia brizantha on performance and carcass dressing. Diets were formulated to contain similar ME and CP protein levels. Forage and nitrogen source interaction was not significant for all studied factors. Daily live weight (LWG/day of animal fed sugar cane (0.83 kg did

Por dentro da autoeficácia: um estudo sobre seus fundamentos teóricos, suas fontes e conceitos correlatos

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Marizeth Barros

2010-09-01

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