Running Cycle Research Articles

P950: COMBINED PROTEASOME AND AUTOPHAGY INHIBITION IN RELAPSED/REFRACTORY MULTIPLE MYELOMA – A PHASE I TRIAL OF HYDROXYCHLOROQUINE, CARFILZOMIB AND DEXAMETHASONE

Background: Multiple myeloma (MM) is characterized by malignant cells which produce large amounts of monoclonal immunoglobulin. MM cells are highly sensitive to drugs that target protein degradation. There are two important intracellular pathways for protein degradation (Lamark, 2010). The proteasome is responsible for the degradation of poly-ubiquitinated damaged, modified, misfolded and redundant proteins (Jung, 2009). This pathway of degradation is the target of proteasome inhibitors. The other main pathway is that of autophagy and lysosomal degradation, eliminating protein aggregates and damaged organelles. Hydroxychloroquine (HCQ) is an inhibitor of autophagy. In vitro studies have shown that HCQ potentiates carfilzomib (K) toxicity towards myeloma cells and could therefore be an attractive treatment option in myeloma (Baranowska, 2016). Here we present safety and efficacy data from a phase 1 study on the combination of HCQ, K and dexamethasone (d). Aims: This study aimed to answer the question whether combined inhibition of the proteasome and the autophagosome is safe and tolerable. The primary endpoint was to establish a maximum tolerated dose (MTD) of the combination HCQ-Kd. Methods: This phase I, single arm, open label dose escalation study (3 + 3 design), included patients with relapsed and/or refractory MM with at least two prior lines of therapy including bortezomib and an immunomodulatory agent. All patients started a 14-day run-in of HCQ at their intended HCQ dose level (DL) before the first cycle of HCQ-Kd. The HCQ DL were 200 mg (DL1), 400 mg (DL2), 600 mg (DL3), and 800 mg (DL4&5) daily. Intravenous carfilzomib was given in a dose of 20 mg/m2 in cycle 1 day 1, and thereafter 56 mg/m2 (DL1-4) and 70 mg/m2 (DL5) on day 8, 15, and in all subsequent cycles and doses. Oral dexamethasone 40 mg (20 mg pts >75y) was administered on day 1, 8, 15 and 22. Patients were treated with HCQ-Kd for a maximum of six 28-day cycles and continued Kd if still responding thereafter. The dose limiting toxicity (DLT) observation period was 28 days. Adverse events (AE) grade (G) 1-5 were registered from day 1 of run-in cycle and until 90 days post last dose of HCQ. Results: The clinical trial is completed, and we here report the data for MTD, safety and efficacy. 19 patients were included. One patient withdrew consent prior to first treatment cycle and was therefore not included in MTD and efficacy analyses. Median previous lines of therapy were 4 (2-9), 50% had high-risk cytogenetics. Only one DLT occurred at DL2 (G3 pneumonia), and MTD was not reached. 104 AEs were recorded, of which G1 45%, G2 32%, G3 22% and G4 1%. No deaths occurred. Most common AEs were anemia (74%), neutropenia (42%), thrombocytopenia (19%), skeletal pain (32%), respiratory tract infections (26%), insomnia (26%) and vomiting/nausea (21%). A total of 13 serious adverse events (SAEs) occurred during the study of which 2 led to treatment discontinuation. Responses were seen in 8 of 18 (ORR 44 %) including 3 PR (18%), 3 VGPR (18%), 1 CR (6%), 1 sCR (6%). Clinical benefit rate was 78 % when including 6 MR (33%) (figure 1). One patient reached MRD negativity. 7 patients did not complete all 6 cycles of HCQ-Kd, 5 due to PD and 2 due to SAEs. Image:Summary/Conclusion: HCQ given up to 800 mg daily in combination with weekly carfilzomib and dexamethasone is well tolerated in patients with relapsed/refractory multiple myeloma. Adverse events were mostly grade 1 and 2. The study results indicate a meaningful clinical efficacy of the combination.

A Workload and Machine Categorization-Based Resource Allocation Framework for Load Balancing and Balanced Resource Utilization in the Cloud

This paper proposes a workload and machine categorization based resource allocation framework for balancing the load across active physical machines as well as utilizing their different resource capacities in a balanced manner. The workload, essentially independent and non-preemptive tasks are allocated resources on the physical machines whose resource availability complements the resource requirement of tasks. Simulation based experiments are performed using CloudSim simulator to execute three different set of tasks comprising 10000, 20000, and 30000 number of tasks. The metric of load imbalance across active physical machines and the metric of utilization imbalance among their considered resource capacities (i.e., CPU and RAM) are measured in different scheduling cycles of a simulation run. Simulation results show that the proposed resource allocation method outperforms the compared methods in terms of balancing the load across active physical machines and utilizing their different resource capacities in a balanced manner.

Energy Consumption of Water Running and Cycling at Four Exercise Intensities.

Water exercise provides a workload in every direction of motion for training in a reduced impact environment. The selection of an appropriate physical activity and an individual exercise prescription are essential to obtain training effects. The aim of the present study was to determine individualised relative exercise intensities at four speeds of motion for water cycling and water running. Running was tested both in buoyancy and with the feet in contact with the bottom of the pool. To this purpose, gas exchanges, heart rate, and blood lactate were measured in each test session. Fourteen active, healthy females (23.2 ± 1.6 years) underwent a dry land maximal incremental protocol to exhaustion on a treadmill and hydrobike (HB); they engaged in water running with ground contact (RC) and water running suspended (RS) tests in a swimming pool at 30, 40, 50, and 60 cycles per minute (cpm), submerged at the individual xiphoid level. The four motion speeds of the three water exercise modalities ranged from 50% to 95% of the maximal heart rate and the maximal oxygen uptake, representing a moderate-to-vigorous training stimulus. RS elicited the lowest oxygen consumption, whereas HB demanded the significantly highest oxygen consumption and presented the highest blood lactate accumulation, with vigorous intensity being reached at 50 cpm and near maximal intensity at 60 cpm. It appears that water cycling could be more suitable for athletic training, whereas water running could be more appropriate for health and fitness purposes.

DESIGN AND IMPLIMENTATION OF A MECHATRONIC SYSTEM NAMELY SEAT CHECK MODULE WITH APPLICATION TO CNC SYSTEM: A REVIEW

In this study an effective method has been developed to automate a process implemented in manufacturing industry "CNC system", it details the research and development of a mechatronic system to overcome one of the most difficult tasks in today's manufacturing industry which is to reduce number of rejected parts of NG parts. This problem mainly occurs when the metal workpiece is disturbed or not properly attached to the fixture and due to that small change in location, it gets improperly machined, which leads to part getting rejected. A gap inspection sensor is included in the design to confirm that the workpiece is properly seated on the fixture and all the components needed for module assembly are designed and tested on a VMC machine. As the gap check sensor uses the principle of back pressure sensing to monitor the gap or distance, the sensor is supplied with pneumatic pressure through a regulator to ensure stabilized input, and outlet of sensor is connected to the orifices on the fixture plate under clamping points, so when the job is placed properly there is no air leakage and the change in pressure will respond to sensor. The developed module gets linked to PLC and needed changes were also made in ladder logic program to incorporate the new module in machine running cycle. This developed architecture is flexible and can be used on many other machines and applications. Doing so automates the machine and prevents potential tool damage and material wastage. Keywords - Mechatronic System, Sensor, Automation, Back pressure Sensing, CNC Programming, PLC program (Ladder Logic), Precision manufacturing

Temporal differences in the myoelectric activity of lower limb muscles during rearfoot and forefoot running: A statistical parametric mapping approach

The aim of this study was to apply statistical parametric mapping (SPM) to compare temporal changes in EMG amplitude between rearfoot (RF) and forefoot (FF) running techniques. Eleven recreational runners ran on a treadmill at a self-selected speed, once using a RF strike pattern and once using a FF strike pattern (randomized order). The myoelectric activity of five lower limb muscles [rectus femoris (RFe), biceps femoris (BF), tibialis anterior (TA), medial and lateral gastrocnemius (MG and LG)] was evaluated, using bipolar electromyography (EMG). EMG data from the RF and FF running techniques was then processed and posteriorly compared with SPM, dividing the analysis of the running cycle into stance and swing phases. The MG and LG muscles showed higher activation during FF running at the beginning of the stance phase and at the end of the swing phase. During the end of the swing phase the TA muscle’s EMG amplitude was higher, when the RF running technique was used. A higher level of co-activation between the gastrocnemius and TA muscles was observed at the end of the swing phase during RF running. The myoelectric behaviour of the RFe and BF muscles was similar during both running techniques. These findings highlight the importance of SPM for the accurate assessment of differences in muscle activity during running and strongly suggest that these two running techniques predominately reflect adjustments of the leg and not the thigh muscles.

The effects of foot orthosis and low-dye tape on lower limb joint angles and moments during running in individuals with pes planus

BackgroundPes Planus or Flat feet is one of the most common lower limb abnormalities. When runners with this abnormality participate in recreational running, interventional therapies could help in pain alleviation and enhance performance. To determine the most effective treatment, however, a biomechanical examination of the effects of each treatment modality is required. Research questionThe aim of the present study was to investigate the effects of Foot Orthoses (FOs) and Low-Dye Tape (LDT) on lower limb joint angles and moments during running in individuals with pes planus. Methodskinematic and kinetic data of 20 young people with pes planus were measured during running in three conditions: (1) SHOD (2) with shoes and FOs (3) with shoes and LDT. One-way repeated measure ANOVA was used to investigate the impacts of the FOs and LDT on the lower limb joint angles and moments throughout the stance phase of the running cycle. ResultsThe results showed that FOs reduced ankle eversion compared to SHOD and LDT (P < 0.001) and decreased the dorsiflexion angle (P = 0.005) and the plantarflexor moment compared to the SHOD (P < 0.001). FOs increased knee adduction angle (P = 0.021) and knee external rotator moment (P < 0.001) compared to both conditions and increased knee extensor and abductor moments compared to SHOD (P < 0.001). At the hip joint, FOs only increased hip external rotation compared with the LDT condition (P = 0.031); and LDT increased hip extensor moment compared to SHOD and FOs (P = 0.037) and also increased hip adduction angle compared to SHOD (P = 0.037). SignificanceFOs with a medial wedge appears to increase the external knee adduction moment and knee adduction angles, which are risk factors for the development and progression of knee osteoarthritis. Further, usage of FOs seems to reduce the ankle joint role in propulsion as it impacts the ankle sagittal angles and moments.

Evaluation of a Novel Simulation Curriculum With the Segmented Model in Pediatric Cardiovascular Education.

ObjectiveThe need to develop the full range of knowledge, skills, and professionalism poses new challenges for pediatric cardiovascular education. This study aimed to investigate the effectiveness of a novel simulation curriculum with the segmented model for pediatric cardiovascular residents.Materials and MethodsFirst, the simulation course was designed according to a prior survey and based on a human patient simulator setting. Then, another 55 residents were randomly selected and assigned to participate in a simulation course (about acute fulminant myocarditis in children), either in the experimental group or the control group. Taking full advantage of the simulation education, the simulation case in the experimental group was divided into three segments and included a micro-debriefing at the end of each segment. The three segments were independent but together formed the whole case. It was designed through three cycles of running and debriefing, and more challenging tasks were gradually proposed to residents. The case in the control group was not split and included only one case running and debriefing. The assessments of the residents' knowledge, skills, professionalism performance, and satisfaction feedback from residents were analyzed to evaluate the effectiveness of the course.ResultsIn total, 44 residents completed the whole experimental period, including 23 participants in the experimental group and 21 participants in the control group. The pre-course knowledge assessment scores of the two groups were comparable, while the mean post-course score in the experimental group was 82.61 ± 17.38, which was significantly higher than that in the control group (50.48 ± 18.57, p < 0.01). The mean skills assessment score of residents in the experimental group was 84.17 ± 6.01, which was significantly higher than the control group (54.50 ± 5.72, p < 0.01). In terms of the professionalism assessment, the residents in the experimental group achieved better performance than those in the control group in all aspects (respect, privacy, communication, responsibility, and cooperation) (p < 0.05). Satisfaction feedback from residents showed that self-confidence regarding knowledge mastery in the experimental group was significantly higher than that in the control group (p < 0.05), while there were no significant differences in the evaluations of the teacher's performance (p > 0.05).ConclusionsThe novel simulation curriculum with the segmented model helps residents achieve better performance in terms of knowledge, skills, and professionalism while improving self-confidence. It has some value in pediatric cardiovascular education and is worthy of further promotion.

Enhanced anaerobic digestion of dairy wastewater in a granular activated carbon amended sequential batch reactor.

This study investigated the potential of granular activated carbon (GAC) supplementation to enhance anaerobic degradation of dairy wastewater. Two sequential batch reactors (SBRs; 0.8 L working volume), one control and another amended with GAC, were operated at 37°C and 1.5–1.6 m/h upflow velocity for a total of 120 days (four cycles of 30 days each). The methane production at the end of each cycle run increased by about 68%, 503%, 110%, and 125% in the GAC‐amended SBR, compared with the Control SBR. Lipid degradation was faster in the presence of GAC. Conversely, the organic compounds, especially lipids, accumulated in the absence of the conductive material. In addition, a reduction in lag phase duration by 46%–100% was observed at all four cycles in the GAC‐amended SBR. The peak methane yield rate was at least 2 folds higher with GAC addition in all cycles. RNA‐based bacterial analysis revealed enrichment of Synergistes (0.8% to 29.2%) and Geobacter (0.4% to 11.3%) in the GAC‐amended SBR. Methanolinea (85.8%) was the dominant archaea in the biofilm grown on GAC, followed by Methanosaeta (11.3%), at RNA level. Overall, this study revealed that GAC supplementation in anaerobic digesters treating dairy wastewater can promote stable and efficient methane production, accelerate lipid degradation and might promote the activity of electroactive microorganisms.

Study on Temperature Sensor Data Anomaly Diagnosis Method Based on Deep Neural Network

In order to solve the problems of low accuracy and low efficiency of traditional sensor data anomaly diagnosis methods, a new temperature sensor data anomaly diagnosis method based on deep neural network is proposed in this paper. Firstly, the temperature sensor data in a running cycle is collected, and the characteristics of the temperature sensor data are extracted by the sliding window technology. Secondly, based on the feature extraction results, a deep neural network model for anomaly diagnosis of temperature sensor data is constructed. The feature data are input into the model, and the result obtained is the diagnosis result. Finally, the simulation comparison experiment is carried out. The experimental results show that the error rate of feature extraction of temperature sensor data in this method changes between −2.1% and 5.9%, the diagnosis accuracy remains above 95%, the average diagnosis time is only 59 ms, and the diagnosis efficiency is high.

H- ion source operational performance and latest development at the Spallation Neutron Source

The U.S. Spallation Neutron Source (SNS) at Oak Ridge National Laboratory is the world’s most powerful accelerator-driven pulsed neutron source. An H- injector feeds the accelerator with high current (>50 mA), time structured (1ms, 60 Hz) H- beam. The injector consists of an RF-driven, Cs-enhanced H- ion source and an electrostatic low energy beam transport section. In the recent three run cycles, an H- ion source operated ∼4 months for each run with excellent availability near 99.9%. The presently ongoing run is also on track to finish another ∼4 months run with similar high availability. Lately, we have tested a solid-state RF system for the ion source to replace the existing vacuum-tube type RF amplifier for the sake of improving the ease of operation and maintenance. Progress has also been made on the continued development of an external antenna RF H- ion source with a focus on improvement to its plasma ignition scheme.

Significant Stability Improvement of Fullerene Organic Photovoltaics via ZnO Film Modification through the Intermittent Spray Pyrolysis Technique.

Morphological control of the layers within the bulk heterojunction organic photovoltaics (BHJ-OPVs) is a key feature that governs their performance. In the present work, we demonstrate that zinc oxide—ZnO—interlayers sprayed via the intermittent spray pyrolysis technique, employing a low-concentration precursor solution, can yield inverted BHJ-OPVs as efficient as the standard reported ones using the conventional laboratory-scale spin-coating technique. However, we record a pioneer stability behavior of the fabricated inverted fullerene organic photovoltaics (iF-OPVs) with various sprayed ZnO conditions. Thus, after optimizing the sprayed ZnO interfacial layer morphology for the inverted PTB7-Th:PC70BM devices, by carefully inspecting the interdependence between the sprayed ZnO thin film morphology and the figures of merit of the optimized iF-OPVs, we conducted a distinct analysis on the optical and electronic properties of the fresh and degraded devices using external quantum efficiency measurements and impedance spectroscopy. Hence, we showed that the most proper ZnO microstructural morphology was obtained by spraying 25 running cycles (25R). Remarkably, we observed that 25R-ZnO-based iF-OPV devices showed a stunning stability behavior and maintained 85% of their initial power conversion efficiency even after 16.7 months without encapsulation in a dry nitrogen glovebox, demonstrating an excellent shelf stability. Accordingly, this approach might facilitate the scalability of inverted OPVs for industrial production visibility.

Effects of Gradient and Speed on Uphill Running Gait Variability.

The aim of this study was to investigate the effects of gradient and speed on running variability (RV) and local dynamic stability (LDS) during uphill running. (1) Both gradient and speed increase metabolic effort, in terms of heart rate (HR) and perceived exertion (CR10), in line with the contemporary literature, and (2) gradient increases RV and impairs LDS. "Crossover" observational design. Level 3. A total of 25 runners completed 10-minute running trials in 3 different conditions and in a randomized order: gradient at 0% (0CON), 2% (2CON), and 2% at isoefficiency speed (2IES). 0CON and 2CON speeds were calculated as the "best 10-km race performance" minus 1 km·h-1, whereas 2IES speed was adjusted to induce the same metabolic expenditure as 0CON. HR and perceived exertion as well as running kinematic variables were collected across all trials and conditions. Running variability was calculated as the standard deviation of the mean stride-to-stride intervals over 100 strides, while LDS was expressed by the Lyapunov exponent (LyE) determined on running cycle time over different running conditions. Increases in HR and CR10 were observed between 0CON and 2CON (P < 0.001) and between 2IES and 2CON (P < 0.01). Higher RV was found in 2CON compared with 0CON and 2IES (both P < 0.001). Finally, the largest LyE was observed in 2IES compared with 0CON and 2CON (P = 0.02 and P = 0.01, respectively). Whereas RV seems to be dependent more on metabolic effort, LDS is affected by gradient to a greater extent. Running variability could be used to monitor external training load in marathon runners.

Enhanced bacterial inactivation by activated carbon modified with nano-sized silver oxides: Performance and mechanism

In this study, nano-sized silver oxides were loaded on activated carbon (nAg2O/AC) through a facile impregnation-calcination method for enhanced bacterial inactivation from drinking water, in which Escherichia coli (E. coli) was used as target bacteria. XRD and SEM characterization confirmed that nano-sized Ag2O particles (50–200 nm) were successfully prepared and uniformly distributed on the surfaces and pores of AC. Due to the structural reducing groups of AC, surface-bound Ag(I) was partially converted to Ag in the nAg2O matrix and the resulted Ag could sterilize E. coli directly. More importantly, surface-bound Ag could catalyze O2 and H2O to generate reactive oxygen species (ROS) for oxidation sterilization, thus significantly enhanced the inactivation efficiency from 0.8 log10 CFU/mL (nAg2O control) and 0.2 log10 CFU/mL (AC control) to 6.0 log10 CFU/mL in the nAg2O/AC system. The inactivation process was highly pH-dependent, and neutral pH was favorable for sterilization. A sterilization efficiency of 5.2 log10 CFU/mL could still be achieved after 5 running cycles, indicating stable sterilization performance of nAg2O/AC. In addition, the nAg2O/AC also exhibited excellent renewability since a sterilization efficiency of 5.8 log10 CFU/mL was obtained after nAg2O being stripped and reloaded on the AC. These results demonstrated that nAg2O-modified AC is an efficient material for sterilization in water treatment.

Changes in blood rheological properties and biochemical markers after participation in the XTERRA Poland triathlon competition

The importance of physical activity in preventing chronic cardiovascular and metabolic diseases and the role of exercise as an adjunct therapy are widely recognized. Triathlon is a typically endurance discipline. Prolonged and intensive exercise is known to cause changes in blood rheological properties and biochemical markers; sometimes athletes participating in strenuous competitions need medical attention. To understand the phenomena occurring in the body in such situations, we decided to study participants’ biomarkers after the XTERRA Poland 2017 triathlon competition. The study involved 10 triathletes. The XTERRA Poland 2017 event comprised 1500-m swimming, 36-km cycling, and 10-km mountain running. Blood samples were collected 2 days before, immediately after, and 16 h after the competition. Immediately after the race, white blood cells count, platelets, and uric acid levels were significantly (P < 0.001) increased; haematocrit, Na+, Cl–, and IgA were decreased. On the following day, Na+, Cl–, and C-reactive protein levels were significantly (P < 0.001) increased; white blood cells count, red blood cells count, haemoglobin, haematocrit, mean corpuscular volume, platelets, IgG, and IgA were decreased. Assessing rheological parameters such as erythrocyte deformability and aggregation is useful for monitoring adverse effects of intensive and exhaustive exercise. The study illustrates the change in blood rheological properties and biochemical markers after intensive physical effort. Despite these differences, the indicators were within the reference range for the general population, which may demonstrate normal body function in the studied triathletes.

Anaerobic derivates of mitochondria and peroxisomes in the free-living amoeba Pelomyxa schiedti revealed by single-cell genomics

BackgroundMitochondria and peroxisomes are the two organelles that are most affected during adaptation to microoxic or anoxic environments. Mitochondria are known to transform into anaerobic mitochondria, hydrogenosomes, mitosomes, and various transition stages in between, collectively called mitochondrion-related organelles (MROs), which vary in enzymatic capacity. Anaerobic peroxisomes were identified only recently, and their putatively most conserved function seems to be the metabolism of inositol. The group Archamoebae includes anaerobes bearing both anaerobic peroxisomes and MROs, specifically hydrogenosomes in free-living Mastigamoeba balamuthi and mitosomes in the human pathogen Entamoeba histolytica, while the organelles within the third lineage represented by Pelomyxa remain uncharacterized.ResultsWe generated high-quality genome and transcriptome drafts from Pelomyxa schiedti using single-cell omics. These data provided clear evidence for anaerobic derivates of mitochondria and peroxisomes in this species, and corresponding vesicles were tentatively identified in electron micrographs. In silico reconstructed MRO metabolism harbors respiratory complex II, electron-transferring flavoprotein, a partial TCA cycle running presumably in the reductive direction, pyruvate:ferredoxin oxidoreductase, [FeFe]-hydrogenases, a glycine cleavage system, a sulfate activation pathway, and an expanded set of NIF enzymes for iron-sulfur cluster assembly. When expressed in the heterologous system of yeast, some of these candidates localized into mitochondria, supporting their involvement in the MRO metabolism. The putative functions of P. schiedti peroxisomes could be pyridoxal 5′-phosphate biosynthesis, amino acid and carbohydrate metabolism, and hydrolase activities. Unexpectedly, out of 67 predicted peroxisomal enzymes, only four were also reported in M. balamuthi, namely peroxisomal processing peptidase, nudix hydrolase, inositol 2-dehydrogenase, and d-lactate dehydrogenase. Localizations in yeast corroborated peroxisomal functions of the latter two.ConclusionsThis study revealed the presence and partially annotated the function of anaerobic derivates of mitochondria and peroxisomes in P. schiedti using single-cell genomics, localizations in yeast heterologous systems, and transmission electron microscopy. The MRO metabolism resembles that of M. balamuthi and most likely reflects the state in the common ancestor of Archamoebae. The peroxisomal metabolism is strikingly richer in P. schiedti. The presence of myo-inositol 2-dehydrogenase in the predicted peroxisomal proteome corroborates the situation in other Archamoebae, but future experimental evidence is needed to verify additional functions of this organelle.

Disrupted Sleep During a Pandemic.

The COVID-19 pandemic affected sleep in several people. Though most of the studies argued that age, gender, employment, finances, responsibilities, and exposure to sunlight governed sleep-wake schedule and sleep disturbances, there is also scientific evidence to suggest that these issues could have aroused because of the infiltration of the central nervous system (CNS) by SARS-CoV-2. Sleep disturbances must be addressed during the pandemic as sleep disturbances and systemic inflammation run in a vicious cycle; quality of sleep and timing of vaccination can influence the immune response to vaccination and subjects having obstructive sleep apnea (OSA) are at higher risk for having SARS-CoV-2 infection-related complications.

Preparation of Waterproof and Air-Permeable Membrane by Water Surface Spreading Method for Metal-Air Battery

The electrochemical performance of metal–air batteries is sensitive to environmental humidity, which significantly limits its wide application in an air environment. In this paper, a waterproof and breathable polydimethylsiloxane (PDMS) composite membrane has been successfully synthesized by the water spreading method for metal–air batteries. The effects of spreading times and fillers (hydrophobic SiO2 and silicalite-1) on the water vapor and air permeability of the PDMS membrane were investigated. The results demonstrate that increasing the spreading times and adding an appropriate amount of hydrophobic SiO2 can improve the waterproof quality and air permeability of the PDMS membrane. The optimized membrane was assembled into a metal–air battery, and the effects of the membrane on the running resistance, cycle number, and polarization voltage of the battery were evaluated. The hydrophobic SiO2–PDMS membrane significantly reduces the running resistance of the battery and improves the cycle number of lithium–air batteries by 25% and that of zinc–air batteries by 100% in an air environment (40% RH, 25 °C). The polarization voltage is also significantly reduced, indicating great potential in applications.

Cell voltage and two-phase flow in a unitized regenerative fuel cell operating in alternate fuel cell and electrolytic cell modes

ABSTRACT Mode switching between fuel cell and electrolytic mode is inevitable for actual applications. During the mode switching, complicated electrical response and gas-liquid phase change occur due to the different operation conditions in these two modes. To explore the effect of water removal method on electrical performance before fuel cell mode startup in mode switching process and get better overall cell performance. In this paper, the continuous mode switching within three cycles is explored by experimental works. It is found that the voltage decreases slightly with the cycle running, and the two-phase flow in the corresponding mode of each cycle is similar through analyzing the two-phase flow phenomenon of the two modes during mode switching. It is also found that bubbles are generated during electrolytic cell, the water is consumed and there is only water mist at the transparent end plate during electrolytic cell mode without water. A handful of liquid water gathers at the bottom of the flow channel during fuel cell mode. Experiments of the cycle test process are also conducted. It is shown that with the cell mode switching periodically, the cell voltages of the electrolytic cell and fuel cell both decrease periodically. The fuel cell performance changes more, especially under high current density.

Seasonal atmospheric water harvesting yield and water quality using electric-powered desiccant and compressor dehumidifiers

Atmospheric water harvesting (AWH) is an emerging technology for decentralized water supply and is proving to be viable for use in emergencies, military deployment, and sustainable industries. The atmosphere is a freshwater reservoir that contains 12,900 km3 of water, 6-fold more than the volume of global rivers. Dehumidification water harvesting technologies can be powered by solar, wind, or electric sources. Compressor/refrigerant-based dehumidifiers operate via dew point condensation and provide a cold surface upon which water vapor can condense. Conversely, desiccant-based technologies saturate water vapor using a sorbent that is then heated, and the supersaturated water vapor condenses on a surface when interacting with cooler ambient process air. This work compares productivity, energy consumption, efficiency, cost and quality of water produced of two water-harvesting mechanisms. Electric-powered compressor and desiccant dehumidifiers were operated outdoors for more than one year in the arid southwestern USA, where temperatures ranged from 3.1 to 43.7 °C and relative humidity (RH) ranged from 6 to 85%. The compressor system harvested >2-fold more water than the desiccant system when average RH during the run cycle was >30%, average temperature was >20 °C, and average dew point temperature was >5 °C. Desiccant systems performed more favorably when average RH during the run cycle was <30%, average temperature was <20 °C, and average dew point temperature was <5 °C. Water collected by compressor-based technologies had conductivity up to 180 μS/cm, turbidity up to 190 NTU, and aluminum, iron and manganese near or above the US EPA secondary drinking water standard. Dissolved organic carbon (DOC) averaged <2 mg C/L but ranged up to 12 mg C/L. Water collected by desiccant-based technologies had significantly lower conductivity, metals, and turbidity, and DOC was always <6 mg/L. Aldehydes such as formaldehyde and acetaldehyde and carboxylic acids such as formic acid and acetic acid were primary contributors to DOC. The differences in harvested water quality were attributed to differences in the condensation method between compressor and desiccant AWH technologies. Multiple strategies could be employed to prevent these volatile organic compounds (VOCs) from contributing to DOC in harvested water, such as pretreating air to remove VOCs or post-treating DOC in harvested liquid water.

The Timing of Thigh Muscle Activity Is a Factor Limiting Performance in the Deceleration Phase of the 100-m Dash.

We aimed to examine the timing of electromyography activity of the rectus femoris (RF) and biceps femoris (BF) in both legs, as well as spatiotemporal variables (running speed (RS), step frequency (SF), step length (SL)) between the maximal speed (Max) phase (50-70 m) and the deceleration (Dec) phase (80-100 m) of the 100-m dash. Nine track and field athletes performed the 100-m dash with maximal effort. Spatiotemporal variables of each 10-m section were measured. A portable wireless data logger was attached to the subject's lower back to record electromyographies. We calculated onset/offset timing (%) of RF and BF in both legs using a Teager-Kaiser Energy Operator filter (e.g., ipsilateral leg RF onset is "iRF-onset," contralateral leg BF onset is "cBF-onset") in a running cycle. The decreased RS in the Dec phase (P < 0.001) was due to a decreased SF (P < 0.001). Moreover, iRF-onset (P = 0.002), iRF-offset (P = 0.008), iBF-offset (P = 0.049), and cBF-offset (P = 0.017) in the Dec phase lagged in the running cycle as compared with the Max phase. Furthermore, the time difference between the swing leg RF activity (iRF-onset) and the contact leg BF activity (cBF-onset; "Scissors1") became bigger in the Dec phase (P = 0.041). Significant negative correlations were found between ΔiRF-onset and ΔSF (P = 0.045), and between ΔiBF-offset and ΔSF (P = 0.036). The decreased RS and SF in the Dec phase of the 100-m dash would be the delayed timing of the RF and BF activities in the same leg as well as the disturbed interleg muscular coordination.