ENDURANCE ATHLETES INTEGRATE FOUR CONDITIONING CONCEPTS IN THEIR TRAINING PROGRAMS: high-volume training (HVT), "threshold-training" (THR), high-intensity interval training (HIIT) and a combination ...of these aforementioned concepts known as polarized training (POL). The purpose of this study was to explore which of these four training concepts provides the greatest response on key components of endurance performance in well-trained endurance athletes.
Forty eight runners, cyclists, triathletes, and cross-country skiers (peak oxygen uptake: (VO2peak): 62.6 ± 7.1 mL·min(-1)·kg(-1)) were randomly assigned to one of four groups performing over 9 weeks. An incremental test, work economy and a VO2peak tests were performed. Training intensity was heart rate controlled.
POL demonstrated the greatest increase in VO2peak (+6.8 ml·min·kg(-1) or 11.7%, P < 0.001), time to exhaustion during the ramp protocol (+17.4%, P < 0.001) and peak velocity/power (+5.1%, P < 0.01). Velocity/power at 4 mmol·L(-1) increased after POL (+8.1%, P < 0.01) and HIIT (+5.6%, P < 0.05). No differences in pre- to post-changes of work economy were found between the groups. Body mass was reduced by 3.7% (P < 0.001) following HIIT, with no changes in the other groups. With the exception of slight improvements in work economy in THR, both HVT and THR had no further effects on measured variables of endurance performance (P > 0.05).
POL resulted in the greatest improvements in most key variables of endurance performance in well-trained endurance athletes. THR or HVT did not lead to further improvements in performance related variables.
This study presents a practical control method for electric vehicle (EV) charging optimisation for detached and attached houses. The developed EV charging control method utilises real‐time ...measurements to minimise charging costs of up to two EVs in a single household. Since some Finnish distribution system operators have already launched peak power‐based distribution tariffs for small‐scale customers and because there is a lot of discussion on this kind of tariff development, the control method considers peak power‐based charges. Additionally, the proposed smart charging control method utilises charging current measurements as feedback to reallocate unused charging capacity if an EV does not utilise the whole capacity allocated for it. The control method is implemented and tested with commercial EVs. The conducted hardware‐in‐the‐loop simulations and measurements confirm that the control method works as intended. The proposed smart charging control reduces EV charging electricity distribution costs around 60% when compared to the uncontrolled EV charging.
The purpose of this study was to determine the relative and absolute reliability using PUSH Pro Band 2.0 IMU to measure peak velocity and power during the countermovement (CMJ) and split-squat jump ...(SSJ). Twenty-three resistance trained males and females completed the study. After a familiarization session, each subject completed 2 identical sessions separated by a minimum of 72 hours that included 4 loads during the CMJ (body weight, body weight plus 20, 40 and 60%) and SSJ (body weight, body weight plus 15, 30 and 45%). In each session, 3 repetitions were completed at each load in randomized order with 3 minutes rest between sets and 5 minutes rest between jump types. Dumbbells held to the side were used to add load. A waist belt was worn that contained the accelerometer. High relative (intra-class coefficient ranging from 0.86-0.99) and absolute (coefficient of variation ranging from 1.7-8.0%) reliability were found for all measures of peak velocity and power during the CMJ and SSJ. The PUSH device produced highly reliable measures of jump performance across all loads between trials and across sessions.
A spectral pre-compensation method based on a novel polarization-encoded filter (PEF) with a single-pass configuration is proposed and investigated, which can support a broadband amplification in a ...high-gain Ti:Sapphire amplifier. The spectral filtering effect is realized by adopting cascaded half-wave plate, quarter-wave plate, quartz crystal and thin film polarizer in this novel filter. Jones calculus is used for theoretically analyzing the characteristics of the PEF. The theoretical analysis demonstrates the advantages of using the cascaded wave plates in the PEF. In the proof-of-principle experiment, we can observe that the use of a single-pass PEF before a high gain (>106) Ti:sapphire (Ti:Sa) regenerative amplifier (RA) can effectively suppress the spectral gain-narrowing effect. The full width at half maximum (FWHM) bandwidth of the amplified pulse increases from 16 nm to 43 nm, and the full bandwidth increases from 73 nm to 90 nm, respectively. After compression, the pulse duration is measured to be 26.9 fs. The PEF provides a practical and effective solution of suppressing the spectral gain-narrowing effect in high gain Ti:sapphire amplifiers.
•We report a spectral precompensation method based on a novel polarization-encoded filter (PEF) with a single-pass configuration.•According to the experimental results, the output spectral width full width at half maximum increases from 16 nm to 43 nm, and the full width increases from 73 nm to 90 nm, which proves the ability to suppress the spectral gain-narrowing effect.•Moreover, this PEF can provide a low cost and high-performance solution to any variable spectral shaping applications.
Improving the overall performance of saturable absorber mirrors (SAMs) based on Two-dimensional (2D) narrow-band-gap materials is critically important in their applications of mid-infrared pulse ...laser sources. Herein, a reflective TaSe2 SAM with laser-induced damage threshold of ∼12 MW/cm2 was successfully fabricated, the saturable absorption properties around 2.8 μm were characterized with a modulation depth of 5.3% and a total unsaturated loss of 2.2%. With the as-prepared SAM, high-peak-power passively Q-switched Er:YAP laser operation at ∼2.8 μm was realized. For the condition of the maximum absorbed pump power of 8.0 W, the maximum average output power of 0.7 W was obtained with a pulse width of 264 ns at a repetition rate of 105.5 kHz, which corresponds to a maximum single pulse energy of 6.6 μ J and a peak power of 25.1 W.
•A reflective TaSe2 SAM with good overall performance was successfully fabricated.•The TaSe2 passively Q-switched Er:YAP bulk laser at 2.8μm was first reported.•Based on the TaSe2 SAM, high peak-power pulse laser at 2.8μm was achieved.
Poly(alkyl‐terphenyl piperidinium) ionomers and membranes were used for H2–O2 anion exchange membrane fuel cells, and achieved a high power density of 2.58 W cm−2, which is a new record for ...polyaromatic‐based fuel cells. Details of the study are described by Young Moo Lee and co‐workers in their Research Article on page 7710.
Poly(alkylterphenylpiperidinium)‐Ionomere und ‐Membranen wurden für H2‐O2‐Anionenaustauschmembran‐Brennstoffzellen entwickelt und erreichen eine hohe Leistungsdichte von 2.58 W cm−2, was einen neuen ...Rekord für Brennstoffzellen auf Polyaromatenbasis darstellt. Details der Studie werden von Young Moo Lee et al. in ihrem Forschungsartikel auf S. 7789 beschrieben.
We demonstrate a multicompartment, power-scalable beam-line design in which sub-40-fs, terawatt field waveforms are tailored in space and time for downstream pulse compression to few-cycle pulse ...widths attained right at the site where the intense laser field interacts with a target. An accurate field-waveform characterization performed at multiple locations along the beam path shows that, despite all the complexity of their upstream nonlinear electrodynamics, field waveforms shorter than three field cycles can be delivered to a laser–matter interaction site in such a system, enabling a vast class of ultrafast strong-field laser–matter interaction studies.
•Sub-40-fs, terawatt field waveforms are tailored in space and time for downstream pulse compression to on-site few-cycle pulse widths in high-power laser beam lines.•Despite all the complexity of their upstream nonlinear electrodynamics, field waveforms shorter than three field cycles can be delivered to a high-power laser–matter interaction site.•This methodology enables a vast class of ultrafast strong-field laser–matter interaction studies.
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•The hourly impact of electric vehicles (EVs) on the electricity system is analysed.•The models include individual driving data to optimise EV-electricity generation.•The demand for ...EVs in Scandinavia-Germany is met by wind power and thermal power.•EVs with vehicle-to-grid substantially reduces the need for peak power capacity.•ERS will increase the current net load profile by up to 18 GW.
This study investigates how electrification of the Scandinavian and German road transportation sectors under a stringent CO2 cap will influence investments in new electricity generation capacity up to Year 2050 and the dispatch of the electricity generation portfolio in Year 2030. We apply a cost-minimisation investment model and an electricity dispatch model of the Scandinavian and German electricity systems, assuming both optimised charging and a vehicle-to-grid (V2G) charging strategy for passenger electric vehicles (EVs). Different EV battery sizes and EV deployment levels are investigated in 11 different scenarios, whereby two of the scenarios include also electric trucks and buses using electric road systems (ERS). The results of the modelling show that with a cap on CO2 emissions, the additional electricity demand from an electrified road transport sector is met mainly by increases in the outputs from wind power and thermal power plants, in the form of coal in combination with carbon capture and storage. In Year 2030, wind power generation in Scandinavia and Germany increases by 7–30% depending on the EV scenario, as compared to a scenario without EVs, which corresponds to a few more percentage points than the increased demand from EVs in absolute terms. Furthermore, a V2G charging strategy for passenger EVs smoothens the net load curve and almost completely reduces the need for peak power capacity in the Scandinavian-German electricity system. The value of investing in solar power is also reduced in all the EV scenarios by 22–42%, as compared to a scenario without EVs. This is due to the fact that in Northern Europe solar power competes with EVs for peak power supply. ERS for mainly trucks and buses will increase the current load profile by up to 18 GW in the Scandinavian-German electricity system.
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