In The Roland De Witte 1991 Experiment (to the Memory of Roland De Witte) , R. T. Cahill gives us a briefing on his view that interferometer measurements and one-way RF coaxial cable propagation-time measurements amount to a detection of the anisotropy in the speedoflight. This startling conclusion is difficult to swallow in the face of rigorous lightspeed in vacuo measurements which are reproducible and flaunt good experimental controls. For instance, in  Eisele et. al. were able to limit anisotropy in c to a fractional uncer- tainty of 10 −17 . It would seem apparent that, to this precision,
O presente trabalho tem como objetivo construir e aplicar uma Unidade de Ensino Potencialmente Significativa (UEPS), baseada na teoria da Aprendizagem Significativa de David Ausubel e proposta por Marco A. Moreira. A UEPS visa facilitar a aprendizagem significativa da teoria da Relatividade Restrita e suprimir o excesso de matematização que envolve a tal teoria. Um dos diferenciais desta UEPS é o uso do game educativo A slower speedoflight e animações. Os temas abordados na unidade de ensino são a dilatação temporal, a contração do comprimento, a invariância da velocidade da luz, a simultaneidade de eventos relativísticos, o efeito holofote e o efeito Terrell. A UEPS construída foi capaz de permitir aulas diferenciadas, fornecendo evidências de uma evolução conceitual por parte dos alunos, viabilizando e incentivando o ensino da física moderna e contemporânea neste nível de ensino. A UEPS desenvolvida neste trabalho foi aplicada em duas salas de uma escola pública de Itapira – SP, sendo que os resultados foram analisados para que se pudesse avaliar a eficácia da unidade de ensino. Ao final do trabalho é apresentado o produto educacional que consiste na UEPS para o ensino da teoria da Relatividade Restrita.
The Apache Point Lunar Laser-ranging Operation (APOLLO), in NM, can detect pho- ton bounces from retroreflectors on the moon surface to 0.1ns timing resolution. This facility enables not only the detection oflightspeed anisotropy, which defines a local preferred frame of reference — only in that frame is the speedoflight isotropic, but also fluctuations/turbulence (gravitational waves) in the flow of the dynamical 3-space rela- tive to local systems/observers. So the APOLLO facility can act as an effective “gravi- tational wave” detector. A recently published small data set from November 5, 2007, is analysed to characterise both the average anisotropy velocity and the wave/turbulence effects. The results are consistent with some 13 previous detections, with the last and most accurate being from the spacecraft earth-flyby Doppler-shift NASA data.
cycle and was presented at 40 frames/sec for a total presentation time of one second. For scrambled PLWs, local motion was applied to 12 white dots at locations drawn from a two-dimensional normal distribution with mean (and standard deviation) location determined from the mean (and standard deviation) location across joints of the intact PLW. This scrambling procedure ensured that the retinal displacement of the intact and scrambled PLWs was comparable. Point-light animations depicting the typical motion of scissors and pliers (“tool motion”) were presented at a reduced frame rate of 29 frames/second. Detailed methods describing the construction of the tool and PLW stimuli can be found in [9,17]. For experiment two, the PLW stimuli consisted of nine randomly selected frames from the animations used in experiment one (presented for one second). Tool point-light displays consisted of randomly selected frames of the tool animations. See Figure 1 for static representations of the four stimulus types used. All stimuli were preceded by a green fixation square, displayed for 500 ms and were followed by a red fixation square presented for a variable duration between 500 and 1000ms (randomly drawn from a uniform distribution). Stimuli were displayed using Presentation software (Neurobehavioral Systems, California, USA).
The rationale behind the direct method is as follows: during the creation of a DHT, the supervisor service per- forms a (weighted) distribution of DHT buckets, among a set of regular services; this initial distribution follows a simple, deterministic algorithm, such that the only infor- mation that is needed to reconstruct that distribution is the number of buckets assigned to each service; later, when a client application opens/creates/reactivates a DHT, the su- pervisor is asked that information which, thereafter, will be used to resolve any lookup request; if the DHT has not yet been redistributed since its creation, then a 100% hit- ratio will be achieved; if the DHT has been somehow redis- tributed, lookup-misses will accumulate and, past a certain configurable threshold, the direct method will be turned off. The cached method consists on distributed lookup, enriched with a client-side LRU cache, per DHT; the cache
This paper presents a contribution to hardened tool steel milling studies. High speed milling is largely utilized to substitute some EDM and polishing operations, mainly in hardened tool steel finishing. Tool path strategy may either enable good surface finish or contributes to generate high roughness values and poor surface finish. Tool inclination (angle between tool axis and workpiece surface) influences the system response to vibration. In this work, several milling experiments were performed in a circular convex AISI D6 hardened steel workpiece, having as input variables feed direction (upward and downward the circle) and tilt angle (tool inclination). The main results indicate that upward tool path presented mostly high roughness values which were also influenced by tool inclination. Downward tool path presented low roughness values and was less influenced by tool inclination. Upward tool path and positive tool inclination should be avoided because they presented roughness values incompatible to EDM process substitution.
The current regulator is a current controller with adjustable hysteresis band width. Modulation Technique used in current regulator. The hysteresis modulation is a feedback current control method. Where the motor current tracks the reference current within a hysteresis band. The operation principle of the hysteresis modulation to controller and generates sinusoidal reference current of desired magnitude frequency which then is compared to the actual motor line current. If current cross the upper limit of the hysteresis band, the upper switch of the inverter arm is turned off and the lower switch is turned on. As a result, the current starts to decrease. If the current cross the lower limit of the hysteresis band, the lower switch of the inverter arm is turned off and the upper switch is turned on. As a result, the current gets back into the hysteresis band. Hence, the actual current is forced to track the reference current within the hysteresis band.
Abstract. The Colebrook [ 1 ] equation is considered the standard for the calculation of friction factor for turbulent ﬂow in commercial pipes, but it is implicit, and therefore it must be computed by iterative meth- ods. Although such iterative computation quickly converges, the com- putational time in large pipe system simulations can be reduced using an accurate explicit correlation. A review of the up to date literature identiﬁed 30 diﬀerent explicit correlations. In order to determine which correlation is the best alternative to Colebrook’s, both accuracy and computational burden were compared. The accuracy of each explicit cor- relation was compared against Colebrook’s correlation using the mean and maximum relative errors and the coeﬃcient of determination. Also, the computational time of each equation was measured using the tic and toc functions in GNU Octave software. It was found that the iterative computation of the Colebrook equation demands about 2.6 times the computational time of the slowest explicit correlation. The correlations with the best balance between accuracy and computational burden are, in decreasing order of accuracy and increasing order ofspeed, correla- tions by Serghides [ 13 ] (Eqs. ( 17 ), ( 18 ), ( 19 ), and ( 20 )), by Shacham [ 8 ] (Eqs. ( 10 ) and ( 11 )), by Brki´c and Praks [ 33 ] (Eqs. ( 53 ), ( 54 ), ( 55 ), and ( 56 )), and by Fang et al. [ 19 ] (Eq. ( 28 )).
In chapter 4 the focus was on gear design. Several parameters were specified according to the current industry developments and requirements. Small module helical gear pairs, which provide better efficiency and NVH behaviour were engineered making use of the capabilities of the KISSsoft software. Two main operating conditions were considered: maximum torque and maximum speed. These are extreme conditions at which the transmission has to operate for a certain period of time, so if the transmission properly works at these conditions, it will certainly correctly operate at normal conditions. It was concluded that when operating at maximum speed, the efficiency is greater but the noise generation increases. All gears comply with the demanded safeties regarding teeth root and flank strength. The stipulated safeties are probably overstated, but there is still a need for additional experimental data to validate this statement.
Our results are consistent with a recent computational model of phase precession (CHADWICK; VAN ROSSUM; NOLAN, 2016). This model was able to account for the speed dependence of the rate of change in the spiking theta phase of place cells as the animal traverses the place field, in which the temporal slope of phase precession is steeper for faster speeds. In turn, the variable temporal slope allows for a fixed relation between spiking theta phase and position at different running speeds (HUXTER; BURGESS; O’KEEFE, 2003; GEISLER et al., 2007, p. 20). The model results crucially relied on the activity of interneurons, which were predicted to receive excitatory inputs dependent on speed (CHADWICK; VAN ROSSUM; NOLAN, 2016). Consistent with this possibility, glutamatergic cells of the medial septum were recently shown to provide CA1 interneurons with a depolarizing drive that increases with running speed (FUHRMANN et al., 2015). Neurons modulated by speed in other subcortical structures such as the mammillary bodies, habenula, and interpeduncular nucleus could potentially contribute (SHARP; TURNER- WILLIAMS, 2005; SHARP; TURNER-WILLIAMS; TUTTLE, 2006). Regardless of the source of excitation, by demonstrating their high modulation by speed, our results support the idea that the activity of inhibitory interneurons in CA1 would allow for flexible timescales of theta spiking sequences (CHADWICK; VAN ROSSUM; NOLAN, 2016).
Studies assessing the adaptations promoted by strength training performed at different speeds of repetitions in isokinetic exercise found that fast speed provides greater strength gains and muscle hypertrophy than the slow speed [5-7]. In opposite, with slow speed the muscles stay more time under tension, which is important for hypertrophy and strength gains . Then, studies are needed using isotonic resistance training, since it is the most common type of resistance training. Furthermore, the cost is generally more feasible when compared with isokinetic equipment. In addition the response of different repetition speed in trained subjects is not clear. Knowing that this population is highly adapted to training stimulus and consequently have low trainability. It is necessary to know what the best strategies to reach their goals are.
Abstract: The aim of this study is to design a simple controller to maximize the extracted energy of wind turbines. In this study the pitch angle control of variable speed wind turbine is investigated. In particular, it concentrates on the extraction of maximum available energy, reduction of torque and output power variations, which gives stresses in the gearbox and mechanical structure. The control concentrates on separate wind speed internals as well as on whole wind speed region. It is found that the control structures varies substantially between the wind speed regions. Two different control systems are compared. The results show that pitch actuator with three levels of pitching speed have better response.
LAr scintillation light quenched by nitrogen contamination to excite TPB. It has been compared to the time behavior of the delayed lightof TPB when excited by β and α particles and they have been found to be perfectly compatible with each other. The time shape of the light emission has also been found to be consistent with what is expected from the delayed luminescence of a unitary scintillator as described in literature. This experiment sheds some light on the most relevant incongruities that have been reported in the past few years concerning the time dependence of LAr scintillation light: namely the presence of an intermediate component with a decay time in the range of 50–100 ns and the ambiguity in the determination of the decay time of the slow component, for which values ranging from 800 to 1600 ns have been reported. LAr scintillation is often used for particle discrimination since the relative abundance of the fast and slow components strongly depends on the particle type. The use of TPB tends to worsen this feature of LAr since a consistent part of the prompt light is delayed and the two populations are more mixed.
Nevertheless, I am undertaking this research in the fields of art and science, seeking to turn my personal circumstance into a premise for this thesis. Thus, I will consider the interdisciplinary practice, both scientific and artistic, within this framework in order to explore the effects caused by dwelling between them. One of the aims of this work is to make concrete the influence of both disciplines in the experimental work and/or the experimenter and maker: me. This research is an opportunity to re-explore the fundamentals oflight that I certainly learned some time ago. Yet, they did not grow as many curiosities back then as they are growing now. Currently, I have been amazed by the rediscovery of the subject, as much as a child would be on his first visit to a science museum. I was encouraged and driven by my new inquiries to engage in a full immersion on the topic in order for the information to be absorbed, breathed in, thought over, digested, spoken and reused. Once the knowledge starts residing in my consciousness it can influence, affect and join other thoughts and ideas, mutating, deforming, multiplying and reconstructing each other. This would urge the formation of new blocks of understanding, letting me recognize the way I perceive the world, motivating an awareness of and within myself, and the way I shape reality.
TODOS 28 D01835100003CI TAMPA LATERAL ESQUERDA AMARELA - SPEED TODOS 29 94014082230ABI PINO DE BORRACHA TODOS 30 00045597010ASI COXIM TODOS 31 D011400008 PARA-LAMA TRASEIRO TODOS 33 93906003ZBI PORCA SEXT. FLANG. RANHURADA M6 (T10) ZB TODOS 34 D01337030000SI REFORCO DE ACO INTERNO TODOS 35 D01801010000SI PARALAMA TRASEIRO INFERIOR TODOS 36 000454070500SN GUIA DO CABO DO VELOCIMETRO TODOS 37 9480200C001I REFLETOR DIANTEIRO TODOS 38 9480100A001N REFLETOR TRASEIRO DAF003 TODOS 39 9493016002PIN SUPORTE DA PLACA 6102 TODOS 40 51001-D01-001 BORRACHA DE ACABAMENTO DO ASSENTO -
As mentioned previously, the red‐shift in absorption observed for DEACM‐ATP when compared to the other DEACM derivatives, and the considerable shift in the 7‐amine pKa, points to the presence of an interaction in the ground‐state between the coumarin ring and the ATP moiety. The larger fluorescence quantum yield and longer decay times (in the nanosecond range, not observed for DEACM‐OH and DEACM‐P) indicates that this association also affects excited state behavior of DEACM‐ATP. A fair assumption can be made that the interaction between coumarin and ATP is a ground‐state intramolecular association between the coumarin and the adenine ring in ATP moiety. The presence of a “sandwich” conformer, formed through stacking of the two rings, might be responsible for leading to a change in coumarin long‐wavelength absorption, and consequently the observed red‐shift. Also, the presence of this sandwich conformer should impair 7‐diethylamino group rotation in the excited state, which would lead to a decrease in the TICT non‐radiative pathway. As a consequence, a less efficient non‐radiative pathway would increase significantly the fluorescence quantum yield, and lead to longer lifetimes, as observed in DEACM‐ATP. From the amplitudes taken from the decay times, circa 40% of the total DEACM‐ATP is present as the sandwich conformer, in 10 mM Tris‐acetate buffer. Hagen and co‐ workers [112,172] reported that for cAMP and cGMP caged nucleotides with 7‐aminocoumarin derivatives, different photochemical quantum yields for the isomers (axial or equatorial, at the phosphate – 4‐ methylcoumarin bond) were found. When comparing the photochemistry of two isomers, both the coumarin derivative and the leaving group are the same, thus this observation cannot be attributed to different stabilization of the carbocation intermediate species. A satisfactory explanation for this observation couldn’t be presented. However, the presence of a ground‐state association between the adenine (or guanine) base and the coumarin chromophore, different in nature or yield between the two isomers, could account for the differences reported. The caged‐cyclic nucleotides present efficient photochemical deactivation, where non‐radiative processes play a minor role in overall excited state deactivation. This might also be the reason why the difference between isomers photochemical quantum yield is not as pronounced as for the DEACM‐ATP vs. DEACM‐P case.
Once the sampling window was properly defined, that means, a sampling windows whose number of bits is such that it results in a sampling period suitable for the bias current calibration of the LED, it will be possible to size the Counter block, which function is to count how many bits with the logic value '1' exist in each sampling window. This Counter block can consist of two binary counters, one that receives the bitstream of data and increments its value to each bit '1'. The other counter receives a clock signal with the same frequency of the binary rate and counts the total amount of bits. Its function is to make auto-clear to the first counter whenever the number of transmitted bits corresponding to the size of the sampling window that has been achieved. The next block is responsible for converting the calculated count to each sampling of the bitstream into a voltage signal. The signal shall describe a curve such that the output value decreases as the number of bits '1' increases and reflects the boundary conditions, i. e. the cases where the number of bits is maximum and minimum, to offer a proper offset. In this sense, the block can be constituted by a LUT - Look Up Table - and a DAC. The DAC converts the binary signal into a voltage signal as intended, but the LUT offers the possibility of easily modeling this linear signal so that the response is adequate and allows to make the resolution of the controller independent of the size of the sampling window. The Transconductance Amplifier block has the function of transforming the received voltage signal from the previous block into a current suitable for the utilized LED. For this, the amplifier must be sized to get a gain according to the maximum current that the LED can receive and must be as linear as possible.
Poincaré map, but without considering the Perron-Frobenius operator for the flow itself. This means that the discretisation of this flow by using a time-1 map provides an example of a system with decay of correlations against L 1 for which it is not known if there exists a spectral gap of the corresponding Perron-Frobenius operator. As we have said, existence of a spectral gap for the map’s Perron-Frobenius operator, defined in some nice function space, appears to be a stronger property than decay of correlations against L 1 observables. However, the latter is still a very strong property. In fact, from decay of correlations against L 1 observables, regardless of the rate, as long as it is summable, one can actually show that the system has exponential decay of correlations of Hölder observables against L ∞ . (See [AFLV11, Theorem B]).
orthopaedic surgeries [1, 2]. Every day, millions of accidents happen involving bone fractures. In the United States alone, about 6.5 million automobile accidents happen annually resulting in femur or tibia fractures and other injuries . The treatment normally requires drilling for screw placement, temporary bone fixation and surface preparation for joint fusion. However, the bone loss at the drilling site could negate any beneficial effects of this type of treatment. Recent studies have shown that the implant failure rate for lower leg osteosynthesis is 2.1–7.1% [4, 5]. One of the main causes of implant failures is the increase of the temperature during the process. Significant heat is produced during drilling due to the friction between the cutting surface of the drill bit in contact with the hole and bone fragments. When the