Heterogeneous electron-transfer kinetics with synchrotron 57Fe Mossbauer spectroscopy

In the first known kinetic application of the technique, synchrotron 57Fe-Mössbauer spectroscopy was used to follow the rate of heterogeneous electron transfer between aqueous reagents and a solid phase containing Fe. The solid, a synthetic 57Fe-enriched Fe (III)-bearing pyroaurite-like phase having terephthalate (TA) in the interlayer [Mg3Fe (OH)8(TA)0.5 • 2H2O], was reduced by Na2S2O4 and then reoxidized by K2Cr2O7 by means of a novel flow-through cell. Synchrotron Mössbauer spectra were collected in the time domain at 30-s intervals. Integration of the intensity obtained during a selected time interval in the spectra allowed sensitive determination of Fe(II) content as a function of reaction time. Analysis of reaction end member specimens by both the synchrotron technique and conventional Mössbauer spectroscopy yielded comparable values for Mössbauer parameters such as center shift and Fe (II)/Fe (III) area ratios. Slight differences in quadrupole splitting values were observed, however. A reactive diffusion model was developed that fit the experimental Fe(II) kinetic data well and allowed the extraction of second-order rate constants for each reaction. Thus, in addition to rapidly collecting high quality Mössbauer data, the synchrotron technique seems well suited for aqueous rate experiments as a result of the penetrating power of 14.4 keV X-rays and high sensitivity to Fe valence state

Effects of Virtual Reality During Rowing Ergometry on Metabolic and Performance Parameters

Physical activity and moderate or intense exercise improve musculoskeletal and metabolic health; however, approximately 80% of Americans do not meet the minimum exercise recommendations from the American College of Sports Medicine (ACSM) or the Centers for Disease Control (CDC). Exercise intensity may be the most important factor in eliciting positive physical outcomes with exercise. PURPOSE: To assess the effectiveness of a proprietary virtual reality (VR) interface to increase metabolic and physical performance during rowing ergometry. METHODS: A novel VR software program for rowing ergometry was developed. Subsequently, sixteen apparently healthy, recreationally active individuals (12M, 4F; 35.5 ± 13.9 y; 174.5 ± 10.1 cm; 80.4 ± 12.8 kg; VO2max: 38.1 ± 5.6 mL/kg/min) were familiarized with the rowing ergometer and VR software, and then completed a VO2max test during two separate sessions. Finally, subjects performed four, 30-min rowing sessions in a randomized, counterbalanced order at maximal voluntary intensity in four different conditions: 1) no augmented visual or audio stimuli (CON), 2) no augmented visual stimuli with self-selected music (MUS), 3) screen-based environmental display (SB), and 4) a virtual reality environment (VR). Oxygen consumption, ventilation, heart rate, and the respiratory exchange ratio (RER) were measured continuously during the four experimental sessions; these data were then averaged over each 30-min testing period. Power output (W) and distance rowed (m) were measured and similarly reduced. Data (mean ± SD) were analyzed by repeated measures ANOVA and appropriate Tukey’s post hoc tests. Alpha was set at P \u3c 0.05. RESULTS: Oxygen consumption (CON: 2.23 ± 0.63 L/min; MUS: 2.30 ± 0.63 L/min; SB: 2.23 ± 0.71 L/min; VR: 2.19 ± 0.69 L/min), ventilation (CON: 74.2 ± 21.0 L/min; MUS: 77.5 ± 20.5 L/min; SB: 73.4 ± 23.9 L/min; VR: 71.7 ± 23.8 L/min), heart rate (CON: 154 ± 16 bpm; MUS: 156 ± 17 bpm; SB: 152 ± 23 bpm; VR: 154 ± 17 bpm), and RER (CON: 0.94 ± 0.04; MUS: 0.95 ± 0.04; SB: 0.94 ± 0.04; VR: 0.93 ± 0.05) were not different between conditions (all P \u3e 0.05). Performance outcomes also did not differ between conditions (CON: 126 ± 40 W, 6337 ± 763 m; MUS: 130 ± 42 W, 6486 ± 617 m; SB: 128 ± 46 W, 6358 ± 862 m; VR: 124 W ± 44 W, 6294 ± 849 m; all P \u3e 0.05). CONCLUSION: The pilot version of the VR software for rowing ergometry did not increase voluntary effort as determined by metabolic or physical performance outputs. Added features, such as greater immersion for reluctant exercisers, and competitive elements for highly motivated individuals, may elicit greater voluntary exertion with VR in rowing ergometry. Moreover, such applications may be more beneficial and improve exercise enjoyment in less experienced exercises who are not accustomed to high exercise intensities

Effects of Virtual Reality During Rowing Ergometry on Presence, Perceived Exertion, and Exercise Enjoyment

Physical inactivity is associated with a host of negative health outcomes. Approximately 80% of Americans do not meet minimum levels of recommended physical activity. Virtual reality (VR) may improve exercise outcomes by enhancing presence, decreasing perceived exertion, and increasing exercise enjoyment. PURPOSE: To assess the effects of a proprietary VR interface on presence, perceived exertion, and exercise enjoyment during rowing ergometry. METHODS: First, we developed a novel VR software program for rowing ergometry. Subsequently, sixteen apparently healthy, recreationally active individuals (12M, 4F; 35.5 ± 13.9 y; 174.5 ± 10.1 cm; 80.4 ± 12.8 kg; VO2max: 38.1 ± 5.6 mL/kg/min) were familiarized with the rowing ergometer and VR software, and then completed a VO2max test during two separate sessions. Finally, subjects performed four, 30-min rowing sessions in a randomized, counterbalanced order at maximal voluntary intensity in four different conditions: 1) no augmented visual or audio stimuli (CON), 2) no augmented visual stimuli with self-selected music (MUS), 3) screen-based environmental display (SB), and 4) a virtual reality environment (VR). Presence (Spatial Presence Experience Scale), perceived exertion (Borg 6-20 scale), and enjoyment (Exercise-Induced Feelings Inventory) were assessed using questionnaires. Data (mean ± SD) were analyzed by repeated measures ANOVA and appropriate Tukey’s post hoc tests. Alpha was set at P \u3c 0.05. RESULTS: Eight of twenty spatial presence items indicated an enhanced experience in VR vs. SB (P \u3c 0.05). Perceived exertion (CON: 14.7 ± 2.1; MUS: 14.9 ± 2.0; SB: 15.2 ± 2.5; VR: 14.9 ± 1.7) and exercise-induced feelings were not different between conditions (P \u3e 0.05). CONCLUSION: The pilot version of the VR software for rowing ergometry did not reduce perceived exertion or increase exercise enjoyment in recreationally active individuals, although it did facilitate improved user presence compared to a screen-based enhanced environment. Added features, such as better coupling of rowing intensity to boat velocity in VR may further enhance presence and immersion, thereby decreasing perceived exertion and increasing exercise enjoyment

In Situ Redox Manipulation Field Injection Test Report - Hanford 100-H Area

This report presents results of an In Situ Redox Manipulation (ISRM) Field Injection Withdrawal Test performed at the 100-H Area of the US. Department of Energy`s (DOE`s) Hanford Site in Washington State in Fiscal Year 1996 by researchers at Pacific Northwest National Laboratory (PNNL). The test is part of the overall ISRM project, the purpose of which is to determine the potential for remediating contaminated groundwater with a technology based on in situ manipulation of subsurface reduction-oxidation (redox) conditions. The ISRM technology would be used to treat subsurface contaminants in groundwater zones at DOE sites

Association Between Anthropometrics, Vertical Jump and Broad Jump to Pure and Transitional Acceleration in Junior College Baseball Players

Sprint acceleration is a key physical attribute in baseball players that can be characterized by two phases: pure (PURE) and transitional (TRANS) acceleration. In a linear sprint, PURE occurs from the initiation of movement to approximately 15-meters; TRANS acceleration occurs from approximately 15-meters until an athlete reaches top velocity. Since baseball fields are clearly marked at 13.7m (foul-line) and 27.4m (1st base), acceleration can be determined in a sports-specific environment and these data may be helpful in characterizing player success. Purpose The purpose of this study was to determine the relationship between anthropometrics, vertical, and broad jump ability to PURE and TRANS acceleration of junior college baseball players sprinting to first-base. Methods: Nineteen male junior college baseball players (19.6 ± 2.2y; 181.2 ± 6.9cm; 80.6 ± 11.7kg) volunteered as subjects. They performed tests of physical performance on three days, separated by one week. Initially, subject height and body mass (BM) were determined using a standard equipment. Percent fat (%Fat) was measured using skinfold calipers and a three-site equation. On a separate day, countermovement vertical jumps were performed on a force plate set to sample at 400 Hz. Vertical jump height (VJ), peak force (PF), peak power (PP), and relative power (PP rel) were determined from these data. Broad jump (BJ) distance was measured using a marked court and tape measure. During a third testing day, subjects performed linear sprints from the batter’s box to first-base. Time was recorded at the foul-line and first-base using hand-held stop watches. Acceleration was computed between the two 13.7 meter intervals to first-base: home-plate to the foul-line (PURE) and foul-line to first-base (TRANS). Pearson’s r were calculated between PURE and TRANS and the anthropometric and performance data. Alpha was set a p \u3c 0.05 which equated to r = 0.44 for df = 18. Results: Of the tested variables, PURE was only associated with %Fat (r = -0.50), TRANS was significantly correlated with %Fat (r = -0.61), VJ (r = -0.50), and PP rel (r \=-0.51). Conclusion: These preliminary data indicate a primary determinant of pure acceleration to first-base is %Fat. VJ and PP relative to body mass are also associated with acceleration from the foul-line to first-base. Interesting, body mass was not related to acceleration in either phase. Therefore, strength and conditioning programs that reduce body fat and develop increased peak vertical power capabilities may be helpful in improving overall acceleration to first-base

Virtual Exercise Training Software System

The purpose of this study was to develop and evaluate a virtual exercise training software system (VETSS) capable of providing real-time instruction and exercise feedback during exploration missions. A resistive exercise instructional system was developed using a Microsoft Kinect depth-camera device, which provides markerless 3-D whole-body motion capture at a small form factor and minimal setup effort. It was hypothesized that subjects using the newly developed instructional software tool would perform the deadlift exercise with more optimal kinematics and consistent technique than those without the instructional software. Following a comprehensive evaluation in the laboratory, the system was deployed for testing and refinement in the NASA Extreme Environment Mission Operations (NEEMO) analog

Speed and Agility Prediction Models in High School Football Players

Background: Optimal relationships between speed, agility, power and body mass are essential in American football. An increase in body mass, theoretically, reduces acceleration (Newton’s 2nd Law). However, an increase in lean body mass may enhance overall force or power generating potential and momentum of an athlete. Body mass, height, and vertical jump height are routinely measured, easily obtainable, and may be used as predictors of speed and agility. Purpose: To determine associations between height, vertical jump height, and body mass to speed and agility in high school football players. Methods: Data were collected on 1261 male football players (16.4±0.9yrs, 179.7±6.9cm, 87.5±18.4kg) at a regional football combine. In successive order, each athlete completed the following tests: height (HT; cm), body mass (BM; kg), 40-yard sprint (SP; s), pro-agility (AG; s), and vertical jump (VJ; cm). The data were collected after a self selected warm-up and athletes were provided three trials on performance drills. HT was measured using a standard stadiometer and BM using a calibrated scale. SP and AG times were measured with hand held stop watches. Finally, a contact mat was used to measure flight time during a countermovement VJ; subsequently VJ height was calculated from flight time using freely falling body equations. Model prediction equations for SP and AG were generated using SigmaStat statistical software package. For each equation, HT, BM, and VJ were set as predictor variables. Non-significant variables were eliminated from the model with an alpha level of p \u3c 0.05. Results: VJ (R=-0.73), BM (R= 0.67), and HT (R = 0.17), were all significant predictors of SP. The combined regression model SP(s) = 6.60561–0.0217VJ+0.00753BM– 0.00438HT explains 73% of the variance in forty yard sprint time (R=0.086; SEE =0.20). HT (R=0.08), BM (R=0.44), and VJ (-0.62) were significantly correlated with AG and were included in the combined regression model: AG(s) = 6.479-0.00437HT+0.00394BM-0.0180VJ (R=0.40; SEE=0.304). Conclusions: HT, VJ, and BM are strong predictors of linear speed. American football players may be able to increase speed by engaging in exercise programs that reduce body mass and improve vertical ground reaction force production. However, these data suggest that HT, BM, and VJ are not as strong of predictors of agility. Future research should address associations between other potential testing constructs and agility in American football players

Project Work Plan Carbon Tetrachloride and Chloroform Attenuation Parameter Studies: Heterogeneous Hydrolytic Reactions

Between 1955 and 1973, an estimated 750,000 kg of carbon tetrachloride were discharged to the soil in the 200 West Area of the Hanford Site as part of the plutonium production process. Of this amount, some carbon tetrachloride reached the groundwater more than 70 m below the ground surface and formed a plume of 10 km2. Recent information has shown that the carbon tetrachloride plume extends to a depth of at least 60 m below the water table. Some carbon tetrachloride has been degraded either by the original process or subsequent transformations in the subsurface to form a co-existing chloroform plume. Although current characterization efforts are improving the conceptual model of the source area, more information is needed to effectively assess the fate and transport of carbon tetrachloride and chloroform to support upcoming remediation decisions for the plume. As noted in a simulation study by Truex et al. (2001), parameters describing porosity, sorption, and abiotic degradation have the largest influence on predicted plume behavior. The work proposed herein will improve the ability to predict future plume movement by better quantifying abiotic degradation mechanisms and rates. This effort will help define how much active remediation may be needed and estimate where the plume will eventually stabilize – key factors in determining the most appropriate remedy for the plume

Next Gen One Portal Usability Evaluation

Each exercise device on the International Space Station (ISS) has a unique, customized software system interface with unique layouts / hierarchy, and operational principles that require significant crew training. Furthermore, the software programs are not adaptable and provide no real-time feedback or motivation to enhance the exercise experience and/or prevent injuries. Additionally, the graphical user interfaces (GUI) of these systems present information through multiple layers resulting in difficulty navigating to the desired screens and functions. These limitations of current exercise device GUI's lead to increased crew time spent on initiating, loading, performing exercises, logging data and exiting the system. To address these limitations a Next Generation One Portal (NextGen One Portal) Crew Countermeasure System (CMS) was developed, which utilizes the latest industry guidelines in GUI designs to provide an intuitive ease of use approach (i.e., 80% of the functionality gained within 5-10 minutes of initial use without/limited formal training required). This is accomplished by providing a consistent interface using common software to reduce crew training, increase efficiency & user satisfaction while also reducing development & maintenance costs. Results from the usability evaluations showed the NextGen One Portal UI having greater efficiency, learnability, memorability, usability and overall user experience than the current Advanced Resistive Exercise Device (ARED) UI used by astronauts on ISS. Specifically, the design of the One-Portal UI as an app interface similar to those found on the Apple and Google's App Store, assisted many of the participants in grasping the concepts of the interface with minimum training. Although the NextGen One-Portal UI was shown to be an overall better interface, observations by the test facilitators noted specific exercise tasks appeared to have a significant impact on the NextGen One-Portal UI efficiency. Future updates to the NextGen One Portal UI will address these inefficiencies

Abiotic reduction of aquifer materials by dithionite: A promising in-situ remediation technology

Laboratory batch and column experiments were conducted with Hanford sediments to develop the capability to predict (1) the longevity of dithionite in these systems, (2) its efficiency as a reductant of structural iron, and (3) the longevity and reactivity of the reduced iron with soluble inorganic and organic species. After an initial induction period, the loss of dithionite by disproportionation and oxidation could be described by pseudo-first-order (PFO) kinetics. Other than the initial reaction with ferric iron, the primary factor promoting loss of dithionite in this system was disproportion nation via heterogeneous catalysis at mineral surfaces. The efficiency of the reduction of structural iron was nearly 100% for the first fourth of the ferric iron, but declined exponentially with higher degrees of reduction so that 75% of the ferric iron could be reduced. This decrease in reduction efficiency probably was related to differences in the accessibility of ferric iron in the mineral particles, with iron in clay-sized particles being the most accessible and that in silt- and sand-sized particles less accessible. Flow-through column studies showed that a reduced-sediment barrier created in this manner could maintain a reducing environment