Carbon plates have been used to increase running shoes' longitudinal bending stiffness (LBS), leading to reductions in the energy cost of level running (Cr). However, whether or not this is true ...during uphill (UH) running remains unknown. The aim of our study was to identify the effect of LBS on Cr during UH running.
Twenty well-trained male runners participated in this study. Cr was determined using gas exchange during nine 4-minute bouts performed using 3 different LBS shoe conditions at 2.22 and 4.44 m/s on level and 2.22 m/s UH (gradient: + 15%) running. All variables were compared using 2-way analyses of variance (LBS × speed/grade effects).
There was no significant effect of LBS (F = 2.04; P = .14, ηp2=.11) and no significant LBS × grade interaction (F = 0.31; P = .87, ηp2=.02). Results were characterized by a very large interindividual variability in response to LBS changes.
The current study contributes to a growing body of literature reporting no effect of LBS on Cr during level and UH running. Yet, the very large interindividual differences in response to changes in LBS suggest that increasing shoe LBS may be beneficial for some runners.
Background
The aim of the present retrospective study was to evaluate complications following carbon-fiber-reinforced polyetheretherketon (CFR-PEEK) volar plating in distal radius fracture in a large ...cohort of patients. As an alternative to conventional metallic devices, CFR-PEEK plates have been introduced over the last few years.
Methods
We performed a retrospective study including all patients who were treated for distal radius fracture using a volar fixed-angle plate DiPHOS-RM (Lima Corporate, Udine, Italy). All CFR-PEEK plates implanted were reviewed between May 2012 and December 2017. Plate removal, second surgery and adverse events were collected by reviewing medical records. A total of 110 patients were included with a mean follow-up of 4 years.
Results
Adverse side effects were observed in 9 cases (8%), developed during or after treatment. The most frequent complication was represented by intraoperative plate rupture (4%). Infection was reported in one case.
Discussion
The rate of complications of PEEK volar plates seems to be similar to those occurring with plates of different materials. Advantages of PEEK plates are the absence of the cold-welding phenomenon and the absence of exuberant bone callus on the plate, ensuring an easy hardware removal. Intraoperative rupture remains the main complication correlated with PEEK material. These complications can be reduced with an accurate surgical technique, especially at the beginning of the learning curve.
Level of evidence
Therapeutic IV.
In adsorption heat pumps, the properties of the porous adsorbent and the refrigerant determine the performance. Major parameters for this working pair are the total uptake of the adsorptive, its ...kinetics, and the heat transfer characteristics. In the technical application despite powdered adsorbents, thin consolidated layers of the adsorbent can be attractive and obtained by a binder‐based approach but likely result in competing material properties. Thus, for a process optimization, the accessible parameter space and interdependencies have to be known and were deduced in this work for model porous carbons (carbide‐derived carbons derived from TiC and ZrC) and methanol as well as the addition of different amounts of boron nitride, silver, and graphite as heat‐conductive agents and the use of two binders.
The utilization of active material, binder, and heat‐conductive additives adds complexity to adsorption cooling systems and therefore leads to an optimization problem of competing material properties. Model adsorption beds were prepared using carbide‐derived carbons derived from TiC or ZrC as model active materials to make this parameter space accessible and to deduce the interdependencies.
An appropriate water balance between membrane dehydration and water flooding is essential to improve the performance and endurance of the polymer electrolyte membrane fuel cell (PEMFC). In this ...study, a novel hydrophilic porous carbon plate (HPCP) is employed as a water transport plate (WTP) to achieve the water balance by virtue of its humidification and water drainage functions. The HPCP is fabricated by electrochemically assisted self-assembly of a hydrophilic silica film on the pore surface of a porous carbon plate (PCP). To overcome the problem that the precursor is unable to enter the hydrophobic pores of the PCP, a novel electro-deposition device forcing the precursor to flow through the pores is designed. Consequently, continuous hydrophilic pores are obtained which promotes the ability of humidification and water drainage. Owing to the humidification function of the HPCP, at the current density of 1000mAcm−2, the voltage of the cell with HPCP is 270mV higher than that with solid plate (SP) under no-humidity. Attributed to the water drainage function, the runtime of the cell is twelve times longer than that with SP under dead-ended cathode operation.
A large number of metallic structures have already reached or even exceeded the limit of their initial design fatigue life. All this paper reports and investigates about the various works carried out ...in order to extend the fatigue life of existing motorway bridges located in the north of France. The studied bridge is composed with two independent decks of a French motorway carrying heavy traffics for 40 years. The slabs of both bridge decks are very fine: steel-concrete composite slabs associating 8 mm steel plate and 100 mm concrete layer according to the original design of Charles Brignon, who was also a pioneer in France of modern fatigue design for bridges, using rounded gussets to attach transverse beams, which reduces the stress concentration factor at the crossing point of the flanges. The structures of the bridges were recently strengthened to extend their fatigue resistance by three different methods which are: Addition of a continuous welded steel plate inclined outside of the edge girders to increase the safety at the Ultimate Limit State (ULS) and the robustness in fatigue of the bottom steel flanges. The inclined additional plate supported by the webs and the free bottom flanges Post weld treatment with Tungsten Inert Gas (TIG) dressing of the welded cross-beams connection gussets were performed. Bonding of CFRP carbon fibres on the bottom steel flanges of the main beams at the extremities of the welded existing cover-plates. These fibres need a high elastic modulus of 400 GPa. The interactions between both fatigue and anticorrosion life extension works are discussed. An innovative option of mixed complete-partial sandblasting methods was proved more economic than the usual complete sandblasting method and performed. The initial conception with two independent decks carrying the highway showed itself particularly relevant for the implementation of heavy repairs. The traffic deviation on the other deck allowed to work on each deck without stopping the traffic.
In order to develop a vertically arranged passive DMFC with a porous carbon plate, PCP, the effect of the head height of the methanol solution in contact with the porous carbon plate on the power ...generation was investigated for a 55
mm height using a single cell. The single cell was operated at several methanol concentrations greater than 70
wt%. By filling the reservoir with 90 and 100
wt% methanol solutions, power densities greater than 30
mW
cm
−2 for over 10
h were demonstrated. Based on the result of the single cell study, a passive DMFC stack consisting of 8 unit cells with the PCP was designed and fabricated. The power generation characteristics were then experimentally measured. The maximum power output of 1.8
W, which was almost 10% lower than that expected from the single cell performance, was obtained with 100% methanol. At the same time, a nonuniform cell voltage among the 8 unit cells was found as a reason for the decreasing power output with the increasing current.
The effect of the pore structure and thickness of the porous carbon plate, PCP, as well as the gas barrier thickness on the methanol transport and the performance of a passive DMFC under the ...different cell voltages of 0.1, 0.2 and 0.3
V using different methanol concentrations was investigated. As a result of the mass transfer restrictions by employing the PCP, high methanol concentrations over 20
M could be efficiently used to produce the relatively high power density of 30
mW
cm
−2 for more than 10
h. The DMFC was operated under limiting current conditions in all the PCPs at 0.1 and 0.2
V to more than 20
M. The main factors for controlling the methanol transport were the barrier of the gas layer with CO
2, which was formed between the anode surface and the PCP and the properties of the PCP. At the low current densities of less than 60
mA
cm
−2, when no CO
2 bubbles are emitted, both the pore structure and thickness of the PCP did not affect the methanol transport and the current voltage relationship. At the higher current densities, CO
2 bubbles were evolved through the PCP and different resistances to the methanol transport were observed depending on the PCP pore structure and thickness. The CO
2 gas layer between the MEA and the PCP caused a major resistivity for the methanol transport, and its resistivity increased with its thickness increasing. By using the PCP at 0.1
V, the energy density of the passive DMFC was significantly increased, e.g., more than seven times.
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