Analytical balance-based Faraday magnetometer

NASA Astrophysics Data System (ADS)

Riminucci, Alberto; Uhlarz, Marc; De Santis, Roberto; Herrmannsdörfer, Thomas

2017-03-01

We introduce a Faraday magnetometer based on an analytical balance in which we were able to apply magnetic fields up to 0.14 T. We calibrated it with a 1 mm Ni sphere previously characterized in a superconducting quantum interference device (SQUID) magnetometer. The proposed magnetometer reached a theoretical sensitivity of 3 × 10-8 A m2. We demonstrated its operation on magnetic composite scaffolds made of poly(ɛ-caprolactone)/iron-doped hydroxyapatite. To confirm the validity of the method, we measured the same scaffold properties in a SQUID magnetometer. The agreement between the two measurements was within 5% at 0.127 T and 12% at 24 mT. With the addition, for a small cost, of a permanent magnet and computer controlled linear translators, we were thus able to assemble a Faraday magnetometer based on an analytical balance, which is a virtually ubiquitous instrument. This will make simple but effective magnetometry easily accessible to most laboratories, in particular, to life sciences ones, which are increasingly interested in magnetic materials.

On firework blasts and qualitative parameter dependency.

PubMed

Zohdi, T I

2016-01-01

In this paper, a mathematical model is developed to qualitatively simulate the progressive time-evolution of a blast from a simple firework. Estimates are made for the blast radius that one can expect for a given amount of detonation energy and pyrotechnic display material. The model balances the released energy from the initial blast pulse with the subsequent kinetic energy and then computes the trajectory of the material under the influence of the drag from the surrounding air, gravity and possible buoyancy. Under certain simplifying assumptions, the model can be solved for analytically. The solution serves as a guide to identifying key parameters that control the evolving blast envelope. Three-dimensional examples are given.

On firework blasts and qualitative parameter dependency

PubMed Central

Zohdi, T. I.

2016-01-01

In this paper, a mathematical model is developed to qualitatively simulate the progressive time-evolution of a blast from a simple firework. Estimates are made for the blast radius that one can expect for a given amount of detonation energy and pyrotechnic display material. The model balances the released energy from the initial blast pulse with the subsequent kinetic energy and then computes the trajectory of the material under the influence of the drag from the surrounding air, gravity and possible buoyancy. Under certain simplifying assumptions, the model can be solved for analytically. The solution serves as a guide to identifying key parameters that control the evolving blast envelope. Three-dimensional examples are given. PMID:26997903

A study of hyperelastic models for predicting the mechanical behavior of extensor apparatus.

PubMed

Elyasi, Nahid; Taheri, Kimia Karimi; Narooei, Keivan; Taheri, Ali Karimi

2017-06-01

In this research, the nonlinear elastic behavior of human extensor apparatus was investigated. To this goal, firstly the best material parameters of hyperelastic strain energy density functions consisting of the Mooney-Rivlin, Ogden, invariants, and general exponential models were derived for the simple tension experimental data. Due to the significance of stress response in other deformation modes of nonlinear models, the calculated parameters were used to study the pure shear and balance biaxial tension behavior of the extensor apparatus. The results indicated that the Mooney-Rivlin model predicts an unstable behavior in the balance biaxial deformation of the extensor apparatus, while the Ogden order 1 represents a stable behavior, although the fitting of experimental data and theoretical model was not satisfactory. However, the Ogden order 6 model was unstable in the simple tension mode and the Ogden order 5 and general exponential models presented accurate and stable results. In order to reduce the material parameters, the invariants model with four material parameters was investigated and this model presented the minimum error and stable behavior in all deformation modes. The ABAQUS Explicit solver was coupled with the VUMAT subroutine code of the invariants model to simulate the mechanical behavior of the central and terminal slips of the extensor apparatus during the passive finger flexion, which is important in the prediction of boutonniere deformity and chronic mallet finger injuries, respectively. Also, to evaluate the adequacy of constitutive models in simulations, the results of the Ogden order 5 were presented. The difference between the predictions was attributed to the better fittings of the invariants model compared with the Ogden model.

A simple scheme for magnetic balance in four-component relativistic Kohn-Sham calculations of nuclear magnetic resonance shielding constants in a Gaussian basis.

PubMed

Olejniczak, Małgorzata; Bast, Radovan; Saue, Trond; Pecul, Magdalena

2012-01-07

We report the implementation of nuclear magnetic resonance (NMR) shielding tensors within the four-component relativistic Kohn-Sham density functional theory including non-collinear spin magnetization and employing London atomic orbitals to ensure gauge origin independent results, together with a new and efficient scheme for assuring correct balance between the large and small components of a molecular four-component spinor in the presence of an external magnetic field (simple magnetic balance). To test our formalism we have carried out calculations of NMR shielding tensors for the HX series (X = F, Cl, Br, I, At), the Xe atom, and the Xe dimer. The advantage of simple magnetic balance scheme combined with the use of London atomic orbitals is the fast convergence of results (when compared with restricted kinetic balance) and elimination of linear dependencies in the basis set (when compared to unrestricted kinetic balance). The effect of including spin magnetization in the description of NMR shielding tensor has been found important for hydrogen atoms in heavy HX molecules, causing an increase of isotropic values of 10%, but negligible for heavy atoms.

A standing location detector enabling people with developmental disabilities to control environmental stimulation through simple physical activities with Nintendo Wii Balance Boards.

PubMed

Shih, Ching-Hsiang

2011-01-01

This study evaluated whether two people with developmental disabilities would be able to actively perform simple physical activities by controlling their favorite environmental stimulation using Nintendo Wii Balance Boards with a newly developed standing location detection program (SLDP, i.e., a new software program turning a Nintendo Wii Balance Board into a standing location detector). This study was carried out using to an ABAB design. The data showed that both participants significantly increased their simple physical activity (target response) to activate the control system to produce environmental stimulation during the B (intervention) phases. The practical and developmental implications of the findings are discussed. Copyright © 2010 Elsevier Ltd. All rights reserved.

Cavendish Balance Automation

NASA Technical Reports Server (NTRS)

Thompson, Bryan

2000-01-01

This is the final report for a project carried out to modify a manual commercial Cavendish Balance for automated use in cryostat. The scope of this project was to modify an off-the-shelf manually operated Cavendish Balance to allow for automated operation for periods of hours or days in cryostat. The purpose of this modification was to allow the balance to be used in the study of effects of superconducting materials on the local gravitational field strength to determine if the strength of gravitational fields can be reduced. A Cavendish Balance was chosen because it is a fairly simple piece of equipment for measuring gravity, one the least accurately known and least understood physical constants. The principle activities that occurred under this purchase order were: (1) All the components necessary to hold and automate the Cavendish Balance in a cryostat were designed. Engineering drawings were made of custom parts to be fabricated, other off-the-shelf parts were procured; (2) Software was written in LabView to control the automation process via a stepper motor controller and stepper motor, and to collect data from the balance during testing; (3)Software was written to take the data collected from the Cavendish Balance and reduce it to give a value for the gravitational constant; (4) The components of the system were assembled and fitted to a cryostat. Also the LabView hardware including the control computer, stepper motor driver, data collection boards, and necessary cabling were assembled; and (5) The system was operated for a number of periods, data collected, and reduced to give an average value for the gravitational constant.

A simple model of hohlraum power balance and mitigation of SRS

DOE PAGES

Albright, Brian J.; Montgomery, David S.; Yin, Lin; ...

2016-04-01

A simple energy balance model has been obtained for laser-plasma heating in indirect drive hohlraum plasma that allows rapid temperature scaling and evolution with parameters such as plasma density and composition. Furthermore, this model enables assessment of the effects on plasma temperature of, e.g., adding high-Z dopant to the gas fill or magnetic fields.

A Standing Location Detector Enabling People with Developmental Disabilities to Control Environmental Stimulation through Simple Physical Activities with Nintendo Wii Balance Boards

ERIC Educational Resources Information Center

Shih, Ching-Hsiang

2011-01-01

This study evaluated whether two people with developmental disabilities would be able to actively perform simple physical activities by controlling their favorite environmental stimulation using Nintendo Wii Balance Boards with a newly developed standing location detection program (SLDP, i.e., a new software program turning a Nintendo Wii Balance…

Gait-force model and inertial measurement unit-based measurements: A new approach for gait analysis and balance monitoring.

PubMed

Li, Xinan; Xu, Hongyuan; Cheung, Jeffrey T

2016-12-01

This work describes a new approach for gait analysis and balance measurement. It uses an inertial measurement unit (IMU) that can either be embedded inside a dynamically unstable platform for balance measurement or mounted on the lower back of a human participant for gait analysis. The acceleration data along three Cartesian coordinates is analyzed by the gait-force model to extract bio-mechanics information in both the dynamic state as in the gait analyzer and the steady state as in the balance scale. For the gait analyzer, the simple, noninvasive and versatile approach makes it appealing to a broad range of applications in clinical diagnosis, rehabilitation monitoring, athletic training, sport-apparel design, and many other areas. For the balance scale, it provides a portable platform to measure the postural deviation and the balance index under visual or vestibular sensory input conditions. Despite its simple construction and operation, excellent agreement has been demonstrated between its performance and the high-cost commercial balance unit over a wide dynamic range. The portable balance scale is an ideal tool for routine monitoring of balance index, fall-risk assessment, and other balance-related health issues for both clinical and household use.

Uncertainty analysis on simple mass balance model to calculate critical loads for soil acidity

Treesearch

Harbin Li; Steven G. McNulty

2007-01-01

Simple mass balance equations (SMBE) of critical acid loads (CAL) in forest soil were developed to assess potential risks of air pollutants to ecosystems. However, to apply SMBE reliably at large scales, SMBE must be tested for adequacy and uncertainty. Our goal was to provide a detailed analysis of uncertainty in SMBE so that sound strategies for scaling up CAL...

10 CFR 72.72 - Material balance, inventory, and records requirements for stored materials.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 2 2010-01-01 2010-01-01 false Material balance, inventory, and records requirements for stored materials. 72.72 Section 72.72 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING...-RELATED GREATER THAN CLASS C WASTE Records, Reports, Inspections, and Enforcement § 72.72 Material balance...

10 CFR 72.72 - Material balance, inventory, and records requirements for stored materials.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 2 2011-01-01 2011-01-01 false Material balance, inventory, and records requirements for stored materials. 72.72 Section 72.72 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING...-RELATED GREATER THAN CLASS C WASTE Records, Reports, Inspections, and Enforcement § 72.72 Material balance...

Emergency material allocation with time-varying supply-demand based on dynamic optimization method for river chemical spills.

PubMed

Liu, Jie; Guo, Liang; Jiang, Jiping; Jiang, Dexun; Wang, Peng

2018-04-13

Aiming to minimize the damage caused by river chemical spills, efficient emergency material allocation is critical for an actual emergency rescue decision-making in a quick response. In this study, an emergency material allocation framework based on time-varying supply-demand constraint is developed to allocate emergency material, minimize the emergency response time, and satisfy the dynamic emergency material requirements in post-accident phases dealing with river chemical spills. In this study, the theoretically critical emergency response time is firstly obtained for the emergency material allocation system to select a series of appropriate emergency material warehouses as potential supportive centers. Then, an enumeration method is applied to identify the practically critical emergency response time, the optimum emergency material allocation and replenishment scheme. Finally, the developed framework is applied to a computational experiment based on south-to-north water transfer project in China. The results illustrate that the proposed methodology is a simple and flexible tool for appropriately allocating emergency material to satisfy time-dynamic demands during emergency decision-making. Therefore, the decision-makers can identify an appropriate emergency material allocation scheme in a balance between time-effective and cost-effective objectives under the different emergency pollution conditions.

A wireless object location detector enabling people with developmental disabilities to control environmental stimulation through simple occupational activities with Nintendo Wii Balance Boards.

PubMed

Shih, Ching-Hsiang; Chang, Man-Ling

2012-01-01

The latest researches have adopted software technology, turning the Nintendo Wii Balance Board into a high performance standing location detector with a newly developed standing location detection program (SLDP). This study extended SLDP functionality to assess whether two people with developmental disabilities would be able to actively perform simple occupational activities by controlling their favorite environmental stimulation using Nintendo Wii Balance Boards and SLDP software. An ABAB design was adopted in this study to perform the tests. The test results showed that, during the intervention phases, both participants significantly increased their target response (i.e. simple occupational activity) to activate the control system to produce environmental stimulation. The practical and developmental implications of the findings are discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.

Water balance models in one-month-ahead streamflow forecasting

USGS Publications Warehouse

Alley, William M.

1985-01-01

Techniques are tested that incorporate information from water balance models in making 1-month-ahead streamflow forecasts in New Jersey. The results are compared to those based on simple autoregressive time series models. The relative performance of the models is dependent on the month of the year in question. The water balance models are most useful for forecasts of April and May flows. For the stations in northern New Jersey, the April and May forecasts were made in order of decreasing reliability using the water-balance-based approaches, using the historical monthly means, and using simple autoregressive models. The water balance models were useful to a lesser extent for forecasts during the fall months. For the rest of the year the improvements in forecasts over those obtained using the simpler autoregressive models were either very small or the simpler models provided better forecasts. When using the water balance models, monthly corrections for bias are found to improve minimum mean-square-error forecasts as well as to improve estimates of the forecast conditional distributions.

The role of boundary layer momentum advection in the mean location of the ITCZ

NASA Astrophysics Data System (ADS)

Dixit, Vishal; Srinivasan, J.

2017-08-01

The inter-tropical convergence zones (ITCZ) form closer to the equator during equinoxes while they form well away from the equator during the boreal summer. A simple three-way balance between the pressure gradients, Coriolis force and effective Rayleigh friction has been classically used to diagnose the location of maximum boundary layer convergence in the near equatorial ITCZ. If such a balance can capture the dynamics of off-equatorial convergence was not known. We used idealized aqua planet simulations with fixed, zonally symmetric sea surface temperature boundary conditions to simulate the near equatorial and off-equatorial ITCZ. As opposed to the convergence of inter-hemispheric flows in the near equatorial convergence, the off-equatorial convergence forms due to the deceleration of cross-equatorial meridional flow. The detailed momentum budget of the off-equatorial convergence zone reveals that the simple balance is not sufficient to capture the relevant dynamics. The deceleration of the meridional flow is strongly modulated by the inertial effects due to the meridional advection of zonal momentum in addition to the terms in the simple balance. The simple balance predicts a spurious near equatorial convergence and a consistent off-equatorial convergence of the meridional flow. The spurious convergence disappears when inertial effects are included in the balance. As cross equatorial meridional flow decelerates to form convergence, the inertial effects cancel the pressure gradient effects near the equator while they add away from the equator. The contribution to the off-equatorial convergence induced by the pressure gradients is significantly larger than the contribution due to the inertial effects and hence pressure gradients appear to be the primary factor in anchoring the strength and location of the off-equatorial convergence.

Electron-emission-induced cooling of boundary region in fusion devices

NASA Astrophysics Data System (ADS)

Mishra, Sanjay K.; Avinash, K.; Kaw, Predhiman; Kaw

2014-12-01

In this brief communication we have explored whether the electron emission from the boundary region surfaces (or from additional fine structured dust particles/droplets of some benign material put purposely in the area surrounding the surfaces) can act as an efficient cooling mechanism for boundary region surfaces/dust electrons and hence the lattice. In order to estimate the contribution of this cooling process a simple kinetic model based on charge flux balance and associated energetics has been established. Along with some additional sophistication like suitable choice of material and modification in the work function via surface coating, the estimates show that it is possible to keep the temperature of the plate/particles well within the critical limit, i.e. melting/sublimation point for the desired regime of incident heat flux.

75 FR 66686 - Defense Federal Acquisition Regulation Supplement; Balance of Payments Program Exemption for...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-29

... Federal Acquisition Regulation Supplement; Balance of Payments Program Exemption for Commercial... Balance of Payments Program for construction material that is commercial information technology. DATES..., Balance of Payments Program--Construction Material, and 252.225- 7045, Balance of Payments Program...

Improving Current Balance In Parallel MOSFET's

NASA Technical Reports Server (NTRS)

Niedra, Janis M.

1992-01-01

Simple circuit makes currents more nearly equal. Addition of diodes and adjustable-tap resistor increases operating range over which drain currents in two unmatched power MOSFET's brought more nearly into balance.

Adequate model complexity for scenario analysis of VOC stripping in a trickling filter.

PubMed

Vanhooren, H; Verbrugge, T; Boeije, G; Demey, D; Vanrolleghem, P A

2001-01-01

Two models describing the stripping of volatile organic contaminants (VOCs) in an industrial trickling filter system are developed. The aim of the models is to investigate the effect of different operating conditions (VOC loads and air flow rates) on the efficiency of VOC stripping and the resulting concentrations in the gas and liquid phases. The first model uses the same principles as the steady-state non-equilibrium activated sludge model Simple Treat, in combination with an existing biofilm model. The second model is a simple mass balance based model only incorporating air and liquid and thus neglecting biofilm effects. In a first approach, the first model was incorporated in a five-layer hydrodynamic model of the trickling filter, using the carrier material design specifications for porosity, water hold-up and specific surface area. A tracer test with lithium was used to validate this approach, and the gas mixing in the filters was studied using continuous CO2 and O2 measurements. With the tracer test results, the biodegradation model was adapted, and it became clear that biodegradation and adsorption to solids can be neglected. On this basis, a simple dynamic mass balance model was built. Simulations with this model reveal that changing the air flow rate in the trickling filter system has little effect on the VOC stripping efficiency at steady state. However, immediately after an air flow rate change, quite high flux and concentration peaks of VOCs can be expected. These phenomena are of major importance for the design of an off-gas treatment facility.

Balancing Chemical Equations: The Role of Developmental Level and Mental Capacity.

ERIC Educational Resources Information Center

Niaz, Mansoor; Lawson, Anton E.

1985-01-01

Tested two hypotheses: (1) formal reasoning is required to balance simple one-step equations; and (2) formal reasoning plus sufficient mental capacity are required to balance many-step equations. Independent variables included intellectual development, mental capacity, and degree of field dependence/independence. With 25 subjects, significance was…

Spray automated balancing of rotors: Methods and materials

NASA Technical Reports Server (NTRS)

Smalley, Anthony J.; Baldwin, Richard M.; Schick, Wilbur R.

1988-01-01

The work described consists of two parts. In the first part, a survey is performed to assess the state of the art in rotor balancing technology as it applies to Army gas turbine engines and associated power transmission hardware. The second part evaluates thermal spray processes for balancing weight addition in an automated balancing procedure. The industry survey reveals that: (1) computerized balancing equipment is valuable to reduce errors, improve balance quality, and provide documentation; (2) slow-speed balancing is used exclusively, with no forseeable need for production high-speed balancing; (3) automated procedures are desired; and (4) thermal spray balancing is viewed with cautious optimism whereas laser balancing is viewed with concern for flight propulsion hardware. The FARE method (Fuel/Air Repetitive Explosion) was selected for experimental evaluation of bond strength and fatigue strength. Material combinations tested were tungsten carbide on stainless steel (17-4), Inconel 718 on Inconel 718, and Triballoy 800 on Inconel 718. Bond strengths were entirely adequate for use in balancing. Material combinations have been identified for use in hot and cold sections of an engine, with fatigue strengths equivalent to those for hand-ground materials.

Balance point characterization of interstitial fluid volume regulation.

PubMed

Dongaonkar, R M; Laine, G A; Stewart, R H; Quick, C M

2009-07-01

The individual processes involved in interstitial fluid volume and protein regulation (microvascular filtration, lymphatic return, and interstitial storage) are relatively simple, yet their interaction is exceedingly complex. There is a notable lack of a first-order, algebraic formula that relates interstitial fluid pressure and protein to critical parameters commonly used to characterize the movement of interstitial fluid and protein. Therefore, the purpose of the present study is to develop a simple, transparent, and general algebraic approach that predicts interstitial fluid pressure (P(i)) and protein concentrations (C(i)) that takes into consideration all three processes. Eight standard equations characterizing fluid and protein flux were solved simultaneously to yield algebraic equations for P(i) and C(i) as functions of parameters characterizing microvascular, interstitial, and lymphatic function. Equilibrium values of P(i) and C(i) arise as balance points from the graphical intersection of transmicrovascular and lymph flows (analogous to Guyton's classical cardiac output-venous return curves). This approach goes beyond describing interstitial fluid balance in terms of conservation of mass by introducing the concept of inflow and outflow resistances. Algebraic solutions demonstrate that P(i) and C(i) result from a ratio of the microvascular filtration coefficient (1/inflow resistance) and effective lymphatic resistance (outflow resistance), and P(i) is unaffected by interstitial compliance. These simple algebraic solutions predict P(i) and C(i) that are consistent with reported measurements. The present work therefore presents a simple, transparent, and general balance point characterization of interstitial fluid balance resulting from the interaction of microvascular, interstitial, and lymphatic function.

Dynamic self-assembly of charged colloidal strings and walls in simple fluid flows.

PubMed

Abe, Yu; Zhang, Bo; Gordillo, Leonardo; Karim, Alireza Mohammad; Francis, Lorraine F; Cheng, Xiang

2017-02-22

Colloidal particles can self-assemble into various ordered structures in fluid flows that have potential applications in biomedicine, materials synthesis and encryption. These dynamic processes are also of fundamental interest for probing the general principles of self-assembly under non-equilibrium conditions. Here, we report a simple microfluidic experiment, where charged colloidal particles self-assemble into flow-aligned 1D strings with regular particle spacing near a solid boundary. Using high-speed confocal microscopy, we systematically investigate the influence of flow rates, electrostatics and particle polydispersity on the observed string structures. By studying the detailed dynamics of stable flow-driven particle pairs, we quantitatively characterize interparticle interactions. Based on the results, we construct a simple model that explains the intriguing non-equilibrium self-assembly process. Our study shows that the colloidal strings arise from a delicate balance between attractive hydrodynamic coupling and repulsive electrostatic interaction between particles. Finally, we demonstrate that, with the assistance of transverse electric fields, a similar mechanism also leads to the formation of 2D colloidal walls.

Complex and Simple Clinical Reaction Times Are Associated with Gait, Balance, and Major Fall Injury in Older Subjects with Diabetic Peripheral Neuropathy

PubMed Central

Richardson, James K.; Eckner, James T.; Allet, Lara; Kim, Hogene; Ashton-Miller, James

2016-01-01

Objective To identify relationships between complex and simple clinical measures of reaction time (RTclin), and indicators of balance in older subjects with and without diabetic peripheral neuropathy (DPN). Design Prospective cohort design. Complex RTclin Accuracy, Simple RTclin Latency, and their ratio were determined using a novel device in 42 subjects (age = 69.1 ± 8.3 yrs), 26 with DPN and 16 without. Dependent variables included unipedal stance time (UST), step width variability and range on an uneven surface, and major fall-related injury over 12 months. Results In the DPN subjects the ratio of Complex RTclin Accuracy:Simple RTclin Latency was strongly associated with longer UST (r/p = .653/.004), and decreased step width variability and range (r/p = −.696/.001 and −.782/<.001, respectively) on an uneven surface. Additionally, the two DPN subjects sustaining major injuries had lower Complex RTclin Accuracy:Simple: RTclin Latency than those without. Conclusions The ratio of Complex RTclin Accuracy:Simple RTclin Latency is a potent predictor of UST and frontal plane gait variability in response to perturbations, and may predict major fall injury in older subjects with DPN. These short latency neurocognitive measures may compensate for lower limb neuromuscular impairments, and provide a more comprehensive understanding of balance and fall risk. PMID:27552354

The Effects of Shoulder Slings on Balance in Patients With Hemiplegic Stroke.

PubMed

Sohn, Min Kyun; Jee, Sung Ju; Hwang, Pyoungsik; Jeon, Yumi; Lee, Hyunkeun

2015-12-01

To investigate the effects of a shoulder sling on balance in patients with hemiplegia. Twenty-seven hemiplegic stroke patients (right 13, left 14) were enrolled in this study. The subjects' movement in their centers of gravity (COGs) during their static and dynamic balance tests was measured with their eyes open in each sling condition-without a sling, with Bobath's axillary support (Bobath sling), and with a simple arm sling. The percent times in quadrant, overall, anterior/posterior, and medial/lateral stability indexes were measured using a posturography platform (Biodex Balance System SD). Functional balance was evaluated using the Berg Balance Scale and the Trunk Impairment Scale. All balance tests were performed with each sling in random order. The COGs of right hemiplegic stroke patients and all hemiplegic stroke patients shifted to, respectively, the right and posterior quadrants during the static balance test without a sling (p<0.05). This weight asymmetry pattern did not improve with either the Bobath or the simple arm sling. There was no significant improvement in any stability index during either the static or the dynamic balance tests in any sling condition. The right and posterior deviations of the hemiplegic stroke patients' COGs were maintained during the application of the shoulder slings, and there were no significant effects of the shoulder slings on the patients' balance in the standing still position.

The Effects of Shoulder Slings on Balance in Patients With Hemiplegic Stroke

PubMed Central

Sohn, Min Kyun; Jee, Sung Ju; Hwang, Pyoungsik; Jeon, Yumi

2015-01-01

Objective To investigate the effects of a shoulder sling on balance in patients with hemiplegia. Methods Twenty-seven hemiplegic stroke patients (right 13, left 14) were enrolled in this study. The subjects' movement in their centers of gravity (COGs) during their static and dynamic balance tests was measured with their eyes open in each sling condition-without a sling, with Bobath's axillary support (Bobath sling), and with a simple arm sling. The percent times in quadrant, overall, anterior/posterior, and medial/lateral stability indexes were measured using a posturography platform (Biodex Balance System SD). Functional balance was evaluated using the Berg Balance Scale and the Trunk Impairment Scale. All balance tests were performed with each sling in random order. Results The COGs of right hemiplegic stroke patients and all hemiplegic stroke patients shifted to, respectively, the right and posterior quadrants during the static balance test without a sling (p<0.05). This weight asymmetry pattern did not improve with either the Bobath or the simple arm sling. There was no significant improvement in any stability index during either the static or the dynamic balance tests in any sling condition. Conclusion The right and posterior deviations of the hemiplegic stroke patients' COGs were maintained during the application of the shoulder slings, and there were no significant effects of the shoulder slings on the patients' balance in the standing still position. PMID:26798614

Development of a simplified urban water balance model (WABILA).

PubMed

Henrichs, M; Langner, J; Uhl, M

2016-01-01

During the last decade, water sensitive urban design (WSUD) has become more and more accepted. However, there is not any simple tool or option available to evaluate the influence of these measures on the local water balance. To counteract the impact of new settlements, planners focus on mitigating increases in runoff through installation of infiltration systems. This leads to an increasing non-natural groundwater recharge and decreased evapotranspiration. Simple software tools which evaluate or simulate the effect of WSUD on the local water balance are still needed. The authors developed a tool named WABILA (Wasserbilanz) that could support planners for optimal WSUD. WABILA is an easy-to-use planning tool that is based on simplified regression functions for established measures and land covers. Results show that WSUD has to be site-specific, based on climate conditions and the natural water balance.

A Multipurpose Experiment with an Electronic Balance

ERIC Educational Resources Information Center

Ganci, S.

2008-01-01

This short article describes some useful and quick applications of a cooking electronic balance. Newton's third law, Archimedes buoyancy and an estimate of relative density are accomplished in a very simple way. (Contains 1 figure.)

78 FR 28540 - Airworthiness Directives; Hawker Beechcraft Corporation

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-15

... airplanes. That NPRM proposed requiring inspections of elevator balance weights and replacement of defective elevator balance weights. That NPRM was prompted by reports of elevator balance weights becoming loose or failing because the balance weight material was under strength and did not meet material specifications...

Simple Forest Canopy Thermal Exitance Model

NASA Technical Reports Server (NTRS)

Smith J. A.; Goltz, S. M.

1999-01-01

We describe a model to calculate brightness temperature and surface energy balance for a forest canopy system. The model is an extension of an earlier vegetation only model by inclusion of a simple soil layer. The root mean square error in brightness temperature for a dense forest canopy was 2.5 C. Surface energy balance predictions were also in good agreement. The corresponding root mean square errors for net radiation, latent, and sensible heat were 38.9, 30.7, and 41.4 W/sq m respectively.

Two-way ANOVA Problems with Simple Numbers.

ERIC Educational Resources Information Center

Read, K. L. Q.; Shihab, L. H.

1998-01-01

Describes how to construct simple numerical examples in two-way ANOVAs, specifically randomized blocks, balanced two-way layouts, and Latin squares. Indicates that working through simple numerical problems is helpful to students meeting a technique for the first time and should be followed by computer-based analysis of larger, real datasets when…

The Effects of Class Organization Upon the Balance Performance of Young Children.

ERIC Educational Resources Information Center

MacCracken, Mary Jo

The effects of the presence of others on 120 young children's performance of balancing skills were tested. The boys and girls, aged four, six, and eight, were tested under three different conditions: while acting "alone," in coaction (pairs), and alone before an audience. The tests were divided into simple and complex balance tasks, consisting of…

Isostasy for Geoscience Labs.

ERIC Educational Resources Information Center

Diecchio, Richard Joseph

1995-01-01

Presents simple laboratory experiments to help students understand the principle of buoyancy and mass balance. Buoyancy experiments can simulate lithospheric mass balance, crustal loading and unloading, and can be used to model differences between the oceanic and continental lithosphere. (MKR)

The Nitrogen Balancing Act: Tracking the Environmental Performance of Food Production

PubMed Central

McLellan, Eileen L; Cassman, Kenneth G; Eagle, Alison J; Woodbury, Peter B; Sela, Shai; Tonitto, Christina; Marjerison, Rebecca D; van Es, Harold M

2018-01-01

Abstract Farmers, food supply-chain entities, and policymakers need a simple but robust indicator to demonstrate progress toward reducing nitrogen pollution associated with food production. We show that nitrogen balance—the difference between nitrogen inputs and nitrogen outputs in an agricultural production system—is a robust measure of nitrogen losses that is simple to calculate, easily understood, and based on readily available farm data. Nitrogen balance provides farmers with a means of demonstrating to an increasingly concerned public that they are succeeding in reducing nitrogen losses while also improving the overall sustainability of their farming operation. Likewise, supply-chain companies and policymakers can use nitrogen balance to track progress toward sustainability goals. We describe the value of nitrogen balance in translating environmental targets into actionable goals for farmers and illustrate the potential roles of science, policy, and agricultural support networks in helping farmers achieve them. PMID:29662247

The Li And Be Dips Revisited: The Role Of Gyroscopic Pumping.

NASA Astrophysics Data System (ADS)

Garaud, Pascale; Bodenheimer, P.

2011-01-01

The existence of a dip in the observed abundances of Li and Be in young stars in the mass range 1.3 to 1.5 solar masses strongly suggests the presence of an additional mixing mechanism to transport these elements from the outer convection zone down to the region where they are destroyed. However, no simple model to date has been able to reproduce simultaneously the respective amplitudes of the Li and the Be dips, as well as their shapes. We study here the effect of an important new mechanism for rotational mixing called "gyroscopic pumping", first noted for its importance in the dynamics of the solar interior, and find that it does indeed provide an elegant answer to this long-standing problem. Gyroscopic pumping is a simple and very generic consequence of angular momentum conservation in differentially rotating convective regions. The perpetual azimuthal force driving the differential rotation also drives a large-scale meridional circulation through angular momentum conservation. We show here how, specifically for the mass range of the Li-dip stars, the flows thus pumped form a slow, large-scale "conveyor belt" between the inner convective core and the outer convection zone. Li- and Be-rich material flowing down from the outer regions is slowly replaced by Li- and Be-poor material flowing up from the inner regions. Meanwhile, turbulent mixing in the thin overshoot layer also replenishes the outer convection zone with Li- and Be-rich material. Overall, the balance between advection by gyroscopic pumping and turbulent mixing by overshooting motions is found to provide a rather good agreement with observations of Li and Be, within a single and very simple framework. This work was funded by an NSF CAREER award of the presenting author.

Identifying and Evaluating the Relationships that Control a Land Surface Model's Hydrological Behavior

NASA Technical Reports Server (NTRS)

Koster, Randal D.; Mahanama, Sarith P.

2012-01-01

The inherent soil moisture-evaporation relationships used in today 's land surface models (LSMs) arguably reflect a lot of guesswork given the lack of contemporaneous evaporation and soil moisture observations at the spatial scales represented by regional and global models. The inherent soil moisture-runoff relationships used in the LSMs are also of uncertain accuracy. Evaluating these relationships is difficult but crucial given that they have a major impact on how the land component contributes to hydrological and meteorological variability within the climate system. The relationships, it turns out, can be examined efficiently and effectively with a simple water balance model framework. The simple water balance model, driven with multi-decadal observations covering the conterminous United States, shows how different prescribed relationships lead to different manifestations of hydrological variability, some of which can be compared directly to observations. Through the testing of a wide suite of relationships, the simple model provides estimates for the underlying relationships that operate in nature and that should be operating in LSMs. We examine the relationships currently used in a number of different LSMs in the context of the simple water balance model results and make recommendations for potential first-order improvements to these LSMs.

Rainfall characteristics for shallow landsliding in Seattle, Washington, USA

USGS Publications Warehouse

Godt, J.W.; Baum, R.L.; Chleborad, A.F.

2006-01-01

Shallow landsliding in the Seattle, Washington, area, has caused the occasional loss of human life and millions of dollars in damage to property. The effective management of the hazzard requires an understanding of the rainfall conditions that result in landslides. We present an empirical approach to quantify the antecedent moisture conditions and rainstorm intensity and duration that have triggered shallow landsliding using 25 years of hourly rainfull data and a complementary record of landslide occurrence. Our approach combines a simple water balance to estimate the antecedent moisture conditions of hillslope materials and a rainfall intensity-duration threshold to identify periods when shallow landsliding can be expected. The water balance is calibrated with field-monitoring data and combined with the rainfall intensity-duration threshold using a decision tree. Results are cast in terms of a hypothetical landslide warning system. Two widespread landslide events are correctly identified by the warning scheme; however, it is less accurate for more isolated landsliding. Copyright ?? 2005 John Wiley & Sons, Ltd.

48 CFR 252.225-7045 - Balance of Payments Program-Construction Material Under Trade Agreements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Balance of Payments... SOLICITATION PROVISIONS AND CONTRACT CLAUSES Text of Provisions And Clauses 252.225-7045 Balance of Payments... clause: Balance of Payments Program—Construction Material Under Trade Agreements (JUN 2011) (a...

48 CFR 252.225-7044 - Balance of Payments Program-Construction Material.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Balance of Payments... AND CONTRACT CLAUSES Text of Provisions And Clauses 252.225-7044 Balance of Payments Program—Construction Material. As prescribed in 225.7503(a), use the following clause: Balance of Payments Program...

78 FR 51053 - Airworthiness Directives; Beechcraft Corporation and Hawker Beechcraft Corporation

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-20

... of elevator balance weights becoming loose or failing because the balance weight material was under strength and did not meet material specifications. This AD requires inspections of elevator balance weights and replacement of defective elevator balance weights. We are issuing this AD to correct the unsafe...

48 CFR 252.225-7045 - Balance of Payments Program-Construction Material Under Trade Agreements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Balance of Payments... SOLICITATION PROVISIONS AND CONTRACT CLAUSES Text of Provisions And Clauses 252.225-7045 Balance of Payments... clause: Balance of Payments Program—Construction Material Under Trade Agreements (NOV 2009) (a...

48 CFR 252.225-7044 - Balance of Payments Program-Construction Material.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Balance of Payments... AND CONTRACT CLAUSES Text of Provisions And Clauses 252.225-7044 Balance of Payments Program—Construction Material. As prescribed in 225.7503(a)(1), use the following clause: Balance of Payments Program...

Process balance and product quality in the production of natural indigo from Polygonum tinctorium Ait. applying low-technology methods.

PubMed

Bechtold, T; Turcanu, A; Geissler, S; Ganglberger, E

2002-02-01

Indigo is the most important blue component in the class of natural dyes for cellulose and protein fibres. In the moderate European climate Polygonum tinctorium Ait. could be an interesting source for natural indigo (Vat blue 1). Following a cultivation of the plant material a simple procedure for the extraction of the indigo precursor indican was investigated with regard to crop and quality of dye obtained. The dependence of the crop on the storage conditions of the harvested plant material was investigated. The results quantify the distinct sensitivity of the fresh material to the time of storage before extraction with regard to the amount of natural indigo obtained, the photometrically determined indigo content in the product and the shade and colour depth observed in standardised dyeing experiments. A basic set of data is presented, which describes the process in terms of consumption of energy, water and chemicals and organic waste released from the extraction step.

40 CFR Table 5 to Subpart Uuuu of... - Continuous Compliance With Emission Limits and Work Practice Standards

Code of Federal Regulations, 2011 CFR

2011-07-01

... material balance that includes the pertinent data used to determine the percent reduction of total sulfide... material balance; and (3) complying with the continuous compliance requirements for closed-vent systems. 2... material balance that includes the pertinent data used to determine the percent reduction of toluene...

40 CFR Table 5 to Subpart Uuuu of... - Continuous Compliance With Emission Limits and Work Practice Standards

Code of Federal Regulations, 2010 CFR

2010-07-01

... material balance that includes the pertinent data used to determine the percent reduction of total sulfide... material balance; and (3) complying with the continuous compliance requirements for closed-vent systems. 2... material balance that includes the pertinent data used to determine the percent reduction of toluene...

40 CFR 60.104a - Performance tests.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (dry basis); K1 = Material balance and conversion factor, 0.2982 (kg-min)/(hr-dsc-%) [0.0186 (lb-min)/(hr-dscf-%)]; K2 = Material balance and conversion factor, 2.088 (kg-min)/(hr-dscm) [0.1303 (lb-min)/(hr-dscf)]; and K3 = Material balance and conversion factor, 0.0994 (kg-min)/(hr-dscm-%) [0.00624 (lb...

40 CFR 60.104a - Performance tests.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (dry basis); K1 = Material balance and conversion factor, 0.2982 (kg-min)/(hr-dsc-%) [0.0186 (lb-min)/(hr-dscf-%)]; K2 = Material balance and conversion factor, 2.088 (kg-min)/(hr-dscm) [0.1303 (lb-min)/(hr-dscf)]; and K3 = Material balance and conversion factor, 0.0994 (kg-min)/(hr-dscm-%) [0.00624 (lb...

40 CFR Table 3 to Subpart Uuuu of... - Initial Compliance With Emission Limits and Work Practice Standards

Code of Federal Regulations, 2012 CFR

2012-07-01

...) you prepare a material balance that includes the pertinent data used to determine the percent... uncontrolled total sulfide emissions were reduced by at least 75%; (3) you prepare a material balance that... uncontrolled total sulfide emissions were reduced by at least 35%; (3) you prepare a material balance that...

40 CFR 60.104a - Performance tests.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (dry basis); K1 = Material balance and conversion factor, 0.2982 (kg-min)/(hr-dscm-%) [0.0186 (lb-min)/(hr-dscf-%)]; K2 = Material balance and conversion factor, 2.088 (kg-min)/(hr-dscm) [0.1303 (lb-min)/(hr-dscf)]; and K3 = Material balance and conversion factor, 0.0994 (kg-min)/(hr-dscm-%) [0.00624 (lb...

40 CFR Table 5 to Subpart Uuuu of... - Continuous Compliance With Emission Limits and Work Practice Standards

Code of Federal Regulations, 2013 CFR

2013-07-01

...) maintaining a material balance that includes the pertinent data used to determine the percent reduction of... pertinent data from the material balance; and (3) complying with the continuous compliance requirements for... systems (1) maintaining a material balance that includes the pertinent data used to determine the percent...

40 CFR Table 3 to Subpart Uuuu of... - Initial Compliance With Emission Limits and Work Practice Standards

Code of Federal Regulations, 2013 CFR

2013-07-01

...) you prepare a material balance that includes the pertinent data used to determine the percent... uncontrolled total sulfide emissions were reduced by at least 75%; (3) you prepare a material balance that... uncontrolled total sulfide emissions were reduced by at least 35%; (3) you prepare a material balance that...

40 CFR Table 5 to Subpart Uuuu of... - Continuous Compliance With Emission Limits and Work Practice Standards

Code of Federal Regulations, 2014 CFR

2014-07-01

...) maintaining a material balance that includes the pertinent data used to determine the percent reduction of... pertinent data from the material balance; and (3) complying with the continuous compliance requirements for... systems (1) maintaining a material balance that includes the pertinent data used to determine the percent...

40 CFR Table 3 to Subpart Uuuu of... - Initial Compliance With Emission Limits and Work Practice Standards

Code of Federal Regulations, 2014 CFR

2014-07-01

...) you prepare a material balance that includes the pertinent data used to determine the percent... uncontrolled total sulfide emissions were reduced by at least 75%; (3) you prepare a material balance that... uncontrolled total sulfide emissions were reduced by at least 35%; (3) you prepare a material balance that...

40 CFR Table 5 to Subpart Uuuu of... - Continuous Compliance With Emission Limits and Work Practice Standards

Code of Federal Regulations, 2012 CFR

2012-07-01

...) maintaining a material balance that includes the pertinent data used to determine the percent reduction of... pertinent data from the material balance; and (3) complying with the continuous compliance requirements for... systems (1) maintaining a material balance that includes the pertinent data used to determine the percent...

40 CFR 60.104a - Performance tests.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (dry basis); K1 = Material balance and conversion factor, 0.2982 (kg-min)/(hr-dsc-%) [0.0186 (lb-min)/(hr-dscf-%)]; K2 = Material balance and conversion factor, 2.088 (kg-min)/(hr-dscm) [0.1303 (lb-min)/(hr-dscf)]; and K3 = Material balance and conversion factor, 0.0994 (kg-min)/(hr-dscm-%) [0.00624 (lb...

40 CFR 60.104a - Performance tests.

Code of Federal Regulations, 2014 CFR

2014-07-01

... (dry basis); K1 = Material balance and conversion factor, 0.2982 (kg-min)/(hr-dscm-%) [0.0186 (lb-min)/(hr-dscf-%)]; K2 = Material balance and conversion factor, 2.088 (kg-min)/(hr-dscm) [0.1303 (lb-min)/(hr-dscf)]; and K3 = Material balance and conversion factor, 0.0994 (kg-min)/(hr-dscm-%) [0.00624 (lb...

Attenuation of landfill leachate by UK Triassic sandstone aquifer materials. 1. Fate of inorganic pollutants in laboratory columns

NASA Astrophysics Data System (ADS)

Thornton, Steven F.; Tellam, John H.; Lerner, David N.

2000-05-01

The attenuation of inorganic contaminants in acetogenic and methanogenic landfill leachate by calcareous and carbonate-deficient, oxide-rich Triassic sandstone aquifer materials from the English Midlands was examined in laboratory columns. Aqueous equilibrium speciation modelling, simple transport modelling and chemical mass balance approaches are used to evaluate the key processes and aquifer geochemical properties controlling contaminant fate. The results indicate that leachate-rock interactions are dominated by ion-exchange processes, acid-base and redox reactions and sorption/precipitation of metal species. Leachate NH 4 is attenuated by cation exchange with the aquifer sediments; however, NH 4 migration could be described with a simple model using retardation factors. Organic acids in the acetogenic leachate buffered the system pH at low levels during flushing of the calcareous aquifer material. In contrast, equilibrium with Al oxyhydroxide phases initially buffered pH (˜4.5) during flushing of the carbonate-deficient sandstone with methanogenic leachate. This led to the mobilisation of sorbed and oxide-bound heavy metals from the aquifer sediment which migrated as a concentrated pulse at the leachate front. Abiotic reductive dissolution of Mn oxyhydroxides on each aquifer material by leachate Fe 2+ maintains high concentrations of dissolved Mn and buffers the leachate inorganic redox system. This feature is analogous to the Mn-reducing zones found in leachate plumes and in the experiments provides a sink for the leachate Fe load and other heavy metals. The availability of reactive solid phase Mn oxyhydroxides limits the duration of redox buffering and Fe attenuation by these aquifer sediments. Aquifer pH and redox buffering capacity exert a fundamental influence on leachate inorganic contaminant fate in these systems. The implications for the assessment of aquifer vulnerability at landfills are discussed and simple measurements of aquifer properties which may improve the prediction of contaminant attenuation are outlined.

It's Not All About Calories

Cancer.gov

Losing weight is about balancing calories in (food and drink) with calories out (exercise). Sounds simple, right? But if it were that simple, you and the millions of other women struggling with their weight probably would have figured it out.

Human life support during interplanetary travel and domicile. II - Generic Modular Flow Schematic modeling

NASA Technical Reports Server (NTRS)

Farral, Joseph F.; Seshan, P. K.; Rohatgi, Naresh K.

1991-01-01

This paper describes the Generic Modular Flow Schematic (GMFS) architecture capable of encompassing all functional elements of a physical/chemical life support system (LSS). The GMFS can be implemented to synthesize, model, analyze, and quantitatively compare many configurations of LSSs, from a simple, completely open-loop to a very complex closed-loop. The GMFS model is coded in ASPEN, a state-of-the-art chemical process simulation program, to accurately compute the material, heat, and power flow quantities for every stream in each of the subsystem functional elements (SFEs) in the chosen configuration of a life support system. The GMFS approach integrates the various SFEs and subsystems in a hierarchical and modular fashion facilitating rapid substitutions and reconfiguration of a life support system. The comprehensive ASPEN material and energy balance output is transferred to a systems and technology assessment spreadsheet for rigorous system analysis and trade studies.

40 CFR Table 3 to Subpart Uuuu of... - Initial Compliance With Emission Limits and Work Practice Standards

Code of Federal Regulations, 2010 CFR

2010-07-01

... uncontrolled total sulfide emissions were reduced by at least 25%; (3) you prepare a material balance that... reduced by at least 75%; (3) you prepare a material balance that includes the pertinent data used to... emissions were reduced by at least 35%; (3) you prepare a material balance that includes the pertinent data...

40 CFR Table 3 to Subpart Uuuu of... - Initial Compliance With Emission Limits and Work Practice Standards

Code of Federal Regulations, 2011 CFR

2011-07-01

... uncontrolled total sulfide emissions were reduced by at least 25%; (3) you prepare a material balance that... reduced by at least 75%; (3) you prepare a material balance that includes the pertinent data used to... emissions were reduced by at least 35%; (3) you prepare a material balance that includes the pertinent data...

Magneto-mechanical bone growth stimulation by actuation of highly porous ferromagnetic fiber arrays

NASA Astrophysics Data System (ADS)

Markaki, Athina E.; Clyne, Trevor W.

2005-02-01

This work relates to porous material made by bonding together fibres of a magnetic material. When subjected to a magnetic field, the array deforms, with individual fibres becoming magnetised along their length and then tending to line up locally with the direction of the field. An investigation is presented into the concept that this deformation could induce beneficial strains in bone tissue network in the early stages of growth as it grows into the porous fibre array. An analytical model has been developed, based on the deflection of individual fibre segments (between joints) experiencing bending moments as a result of the induced magnetic dipole. The model has been validated via measurements made on simple fibre assemblies and random fibre arrays. Work has also been done on the deformation characteristics of random fibre arrays with a matrix filling the inter-fibre space. This has the effect of reducing the fibre deflections. The extent of this reduction, and an estimate of the maximum strains induced in the space-filling material, can be obtained using a simple force balance approach. Predictions indicate that in-growing bone tissue, with a stiffness of around 0.01-0.1 GPa, could be strained to beneficial levels (~1 millistrain), using magnetic field strengths in current diagnostic use (~1 Tesla), provided the fibre segment aspect ratio is at least about 10. Such material has a low Young"s modulus, but the overall stiffness of a prosthesis could be matched to that of cortical bone by using an integrated design involving a porous magneto-active layer bonded to a dense non-magnetic core.

Mass, energy and material balances of SRF production process. Part 2: SRF produced from construction and demolition waste.

PubMed

Nasrullah, Muhammad; Vainikka, Pasi; Hannula, Janne; Hurme, Markku; Kärki, Janne

2014-11-01

In this work, the fraction of construction and demolition waste (C&D waste) complicated and economically not feasible to sort out for recycling purposes is used to produce solid recovered fuel (SRF) through mechanical treatment (MT). The paper presents the mass, energy and material balances of this SRF production process. All the process streams (input and output) produced in MT waste sorting plant to produce SRF from C&D waste are sampled and treated according to CEN standard methods for SRF. Proximate and ultimate analysis of these streams is performed and their composition is determined. Based on this analysis and composition of process streams their mass, energy and material balances are established for SRF production process. By mass balance means the overall mass flow of input waste material stream in the various output streams and material balances mean the mass flow of components of input waste material stream (such as paper and cardboard, wood, plastic (soft), plastic (hard), textile and rubber) in the various output streams of SRF production process. The results from mass balance of SRF production process showed that of the total input C&D waste material to MT waste sorting plant, 44% was recovered in the form of SRF, 5% as ferrous metal, 1% as non-ferrous metal, and 28% was sorted out as fine fraction, 18% as reject material and 4% as heavy fraction. The energy balance of this SRF production process showed that of the total input energy content of C&D waste material to MT waste sorting plant, 74% was recovered in the form of SRF, 16% belonged to the reject material and rest 10% belonged to the streams of fine fraction and heavy fraction. From the material balances of this process, mass fractions of plastic (soft), paper and cardboard, wood and plastic (hard) recovered in the SRF stream were 84%, 82%, 72% and 68% respectively of their input masses to MT plant. A high mass fraction of plastic (PVC) and rubber material was found in the reject material stream. Streams of heavy fraction and fine fraction mainly contained non-combustible material (such as stone/rock, sand particles and gypsum material). Copyright © 2014 Elsevier Ltd. All rights reserved.

Multimedia modeling of engineered nanoparticles with SimpleBox4nano: model definition and evaluation.

PubMed

Meesters, Johannes A J; Koelmans, Albert A; Quik, Joris T K; Hendriks, A Jan; van de Meent, Dik

2014-05-20

Screening level models for environmental assessment of engineered nanoparticles (ENP) are not generally available. Here, we present SimpleBox4Nano (SB4N) as the first model of this type, assess its validity, and evaluate it by comparisons with a known material flow model. SB4N expresses ENP transport and concentrations in and across air, rain, surface waters, soil, and sediment, accounting for nanospecific processes such as aggregation, attachment, and dissolution. The model solves simultaneous mass balance equations (MBE) using simple matrix algebra. The MBEs link all concentrations and transfer processes using first-order rate constants for all processes known to be relevant for ENPs. The first-order rate constants are obtained from the literature. The output of SB4N is mass concentrations of ENPs as free dispersive species, heteroaggregates with natural colloids, and larger natural particles in each compartment in time and at steady state. Known scenario studies for Switzerland were used to demonstrate the impact of the transport processes included in SB4N on the prediction of environmental concentrations. We argue that SB4N-predicted environmental concentrations are useful as background concentrations in environmental risk assessment.

Behavior of silica aerogel networks as highly porous solid solvent media for lipases in a model transesterification reaction.

PubMed

El Rassy, H; Perrard, A; Pierre, A C

2003-03-03

Highly porous silica aerogels with differing balances of hydrophobic and hydrophilic functionalities were studied as a new immobilization medium for enzymes. Two types of lipases from Candida rugosa and Burkholderia cepacia were homogeneously dispersed in wet gel precursors before gelation. The materials obtained were compared in a simple model reaction: transesterification of vinyl laurate by 1-octanol. To allow a better comparison of the hydrophobic/hydrophilic action of the solid, very open aerogel networks with traditional organic hydrophobic/hydrophilic liquid solvents, this reaction was studied in mixtures containing different proportions of 2-methyl-2-butanol, isooctane, and water. The results are discussed in relation to the porous and hydrophobic nature of aerogels, characterized by nitrogen adsorption. It was found that silica aerogels can be considered as "solid" solvents for the enzymes, able to provide hydrophobic/hydrophilic characteristics different from those prevailing in the liquid surrounding the aerogels. A simple mechanism of action for these aerogel networks is proposed.

Mass, energy and material balances of SRF production process. Part 3: solid recovered fuel produced from municipal solid waste.

PubMed

Nasrullah, Muhammad; Vainikka, Pasi; Hannula, Janne; Hurme, Markku; Kärki, Janne

2015-02-01

This is the third and final part of the three-part article written to describe the mass, energy and material balances of the solid recovered fuel production process produced from various types of waste streams through mechanical treatment. This article focused the production of solid recovered fuel from municipal solid waste. The stream of municipal solid waste used here as an input waste material to produce solid recovered fuel is energy waste collected from households of municipality. This article presents the mass, energy and material balances of the solid recovered fuel production process. These balances are based on the proximate as well as the ultimate analysis and the composition determination of various streams of material produced in a solid recovered fuel production plant. All the process streams are sampled and treated according to CEN standard methods for solid recovered fuel. The results of the mass balance of the solid recovered fuel production process showed that 72% of the input waste material was recovered in the form of solid recovered fuel; 2.6% as ferrous metal, 0.4% as non-ferrous metal, 11% was sorted as rejects material, 12% as fine faction and 2% as heavy fraction. The energy balance of the solid recovered fuel production process showed that 86% of the total input energy content of input waste material was recovered in the form of solid recovered fuel. The remaining percentage (14%) of the input energy was split into the streams of reject material, fine fraction and heavy fraction. The material balances of this process showed that mass fraction of paper and cardboard, plastic (soft) and wood recovered in the solid recovered fuel stream was 88%, 85% and 90%, respectively, of their input mass. A high mass fraction of rubber material, plastic (PVC-plastic) and inert (stone/rock and glass particles) was found in the reject material stream. © The Author(s) 2014.

Balance Contrast Enhancement using piecewise linear stretching

NASA Astrophysics Data System (ADS)

Rahavan, R. V.; Govil, R. C.

1993-04-01

Balance Contrast Enhancement is one of the techniques employed to produce color composites with increased color contrast. It equalizes the three images used for color composition in range and mean. This results in a color composite with large variation in hue. Here, it is shown that piecewise linear stretching can be used for performing the Balance Contrast Enhancement. In comparison with the Balance Contrast Enhancement Technique using parabolic segment as transfer function (BCETP), the method presented here is algorithmically simple, constraint-free and produces comparable results.

Models of convection-driven tectonic plates - A comparison of methods and results

NASA Technical Reports Server (NTRS)

King, Scott D.; Gable, Carl W.; Weinstein, Stuart A.

1992-01-01

Recent numerical studies of convection in the earth's mantle have included various features of plate tectonics. This paper describes three methods of modeling plates: through material properties, through force balance, and through a thin power-law sheet approximation. The results obtained are compared using each method on a series of simple calculations. From these results, scaling relations between the different parameterizations are developed. While each method produces different degrees of deformation within the surface plate, the surface heat flux and average plate velocity agree to within a few percent. The main results are not dependent upon the plate modeling method and herefore are representative of the physical system modeled.

New views of granular mass flows

USGS Publications Warehouse

Iverson, R.M.; Vallance, J.W.

2001-01-01

Concentrated grain-fluid mixtures in rock avalanches, debris flows, and pyroclastic flows do not behave as simple materials with fixed rheologies. Instead, rheology evolves as mixture agitation, grain concentration, and fluid-pressure change during flow initiation, transit, and deposition. Throughout a flow, however, normal forces on planes parallel to the free upper surface approximately balance the weight of the superincumbent mixture, and the Coulomb friction rule describes bulk intergranular shear stresses on such planes. Pore-fluid pressure can temporarily or locally enhance mixture mobility by reducing Coulomb friction and transferring shear stress to the fluid phase. Initial conditions, boundary conditions, and grain comminution and sorting can influence pore-fluid pressures and cause variations in flow dynamics and deposits.

Functional measures show improvements after a home exercise program following supervised balance training in older adults with elevated fall risk.

PubMed

Tisher, Kristen; Mann, Kimberly; VanDyke, Sarah; Johansson, Charity; Vallabhajosula, Srikant

2018-03-05

Supervised balance training shows immediate benefit for older adults at fall risk. The long-term effectiveness of such training can be enhanced by implementing a safe and simple home exercise program (HEP). We investigated the effects of a12-week unsupervised HEP following supervised clinic-based balance training on functional mobility, balance, fall risk, and gait. Six older adults with an elevated fall risk obtained an HEP and comprised the HEP group (HEPG) and five older adults who were not given an HEP comprised the no HEP group (NoHEPG). The HEP consisted of three static balance exercises: feet-together, single-leg stance, and tandem. Each exercise was to be performed twice for 30-60 s, once per day, 3 days per week for 12 weeks. Participants were educated on proper form, safety, and progression of exercises. Pre- and post-HEP testing included Berg Balance Scale (BBS), Timed Up and Go, Short Physical Performance Battery (SPPB) assessments, Activities-Balance Confidence, Late-Life Functional Disability Instrument and instrumented assessments of balance and gait (Limits of Stability, modified Clinical Test of Sensory Interaction on Balance, Gait). A healthy control group (HCG; n = 11) was also tested. For most of the measures, the HEPG improved to the level of HCG. Though task-specific improvements like BBS and SPPB components were seen, the results did not carry over to more dynamic assessments. Results provide proof of concept that a simple HEP can be independently implemented and effective for sustaining and/or improving balance in older adults at elevated fall-risk after they have undergone a clinic-based balance intervention.

A review on simple assembly line balancing type-e problem

NASA Astrophysics Data System (ADS)

Jusop, M.; Rashid, M. F. F. Ab

2015-12-01

Simple assembly line balancing (SALB) is an attempt to assign the tasks to the various workstations along the line so that the precedence relations are satisfied and some performance measure are optimised. Advanced approach of algorithm is necessary to solve large-scale problems as SALB is a class of NP-hard. Only a few studies are focusing on simple assembly line balancing of Type-E problem (SALB-E) since it is a general and complex problem. SALB-E problem is one of SALB problem which consider the number of workstation and the cycle time simultaneously for the purpose of maximising the line efficiency. This paper review previous works that has been done in order to optimise SALB -E problem. Besides that, this paper also reviewed the Genetic Algorithm approach that has been used to optimise SALB-E. From the reviewed that has been done, it was found that none of the existing works are concern on the resource constraint in the SALB-E problem especially on machine and tool constraints. The research on SALB-E will contribute to the improvement of productivity in real industrial application.

Considerations affecting the additional weight required in mass balance of ailerons

NASA Technical Reports Server (NTRS)

Diehl, W S

1937-01-01

This paper is essentially a consideration of mass balance of ailerons from a preliminary design standpoint, in which the extra weight of the mass counterbalance is the most important phase of the problem. Equations are developed for the required balance weight for a simple aileron and this weight is correlated with the mass-balance coefficient. It is concluded the location of the c.g. of the basic aileron is of paramount importance and that complete mass balance imposes no great weight penalty if the aileron is designed to have its c.g. inherently near to the hinge axis.

10 CFR 75.8 - IAEA inspections.

Code of Federal Regulations, 2011 CFR

2011-01-01

... exports) or § 75.43(c) (pertaining to imports) at any place where nuclear material may be located; (3... nuclear material at key measurement points for material balance accounting are representative; (3) Verify... samples at key measurement points for material balance accounting are taken in accordance with procedures...

Impacts of invasive earthworms on soil mercury cycling: Two mass balance approaches to an earthworm invasion in a northern Minnesota forest

Treesearch

Sona Psarska; Edward A. Nater; Randy Kolka

2016-01-01

Invasive earthworms perturb natural forest ecosystems that initially developed without them, mainly by consuming the forest floor (an organic rich surficial soil horizon) and by mixing the upper parts of the soil. The fate of mercury (Hg) formerly contained in the forest floor is largely unknown. We used two mass balance approaches (simple mass balance and geochemical...

A heuristic simulation model of Lake Ontario circulation and mass balance transport

USGS Publications Warehouse

McKenna, J.E.; Chalupnicki, M.A.

2011-01-01

The redistribution of suspended organisms and materials by large-scale currents is part of natural ecological processes in large aquatic systems but can contribute to ecosystem disruption when exotic elements are introduced into the system. Toxic compounds and planktonic organisms spend various lengths of time in suspension before settling to the bottom or otherwise being removed. We constructed a simple physical simulation model, including the influence of major tributaries, to qualitatively examine circulation patterns in Lake Ontario. We used a simple mass balance approach to estimate the relative water input to and export from each of 10 depth regime-specific compartments (nearshore vs. offshore) comprising Lake Ontario. Despite its simplicity, our model produced circulation patterns similar to those reported by more complex studies in the literature. A three-gyre pattern, with the classic large counterclockwise central lake circulation, and a simpler two-gyre system were both observed. These qualitative simulations indicate little offshore transport along the south shore, except near the mouths of the Niagara River and Oswego River. Complex flow structure was evident, particularly near the Niagara River mouth and in offshore waters of the eastern basin. Average Lake Ontario residence time is 8 years, but the fastest model pathway indicated potential transport of plankton through the lake in as little as 60 days. This simulation illustrates potential invasion pathways and provides rough estimates of planktonic larval dispersal or chemical transport among nearshore and offshore areas of Lake Ontario. ?? 2011 Taylor & Francis.

Interpreting lateral dynamic weight shifts using a simple inverted pendulum model.

PubMed

Kennedy, Michael W; Bretl, Timothy; Schmiedeler, James P

2014-01-01

Seventy-five young, healthy adults completed a lateral weight-shifting activity in which each shifted his/her center of pressure (CoP) to visually displayed target locations with the aid of visual CoP feedback. Each subject's CoP data were modeled using a single-link inverted pendulum system with a spring-damper at the joint. This extends the simple inverted pendulum model of static balance in the sagittal plane to lateral weight-shifting balance. The model controlled pendulum angle using PD control and a ramp setpoint trajectory, and weight-shifting was characterized by both shift speed and a non-minimum phase (NMP) behavior metric. This NMP behavior metric examines the force magnitude at shift initiation and provides weight-shifting balance performance information that parallels the examination of peak ground reaction forces in gait analysis. Control parameters were optimized on a subject-by-subject basis to match balance metrics for modeled results to metric values calculated from experimental data. Overall, the model matches experimental data well (average percent error of 0.35% for shifting speed and 0.05% for NMP behavior). These results suggest that the single-link inverted pendulum model can be used effectively to capture lateral weight-shifting balance, as it has been shown to model static balance. Copyright © 2014 Elsevier B.V. All rights reserved.

Hands-on Scorecarding in the Higher Education Sector

ERIC Educational Resources Information Center

Scholey, Cam; Armitage, Howard

2006-01-01

The balanced scorecard, introduced by Robert Kaplan and David Norton, has evolved from an improved performance measurement system to an integrated strategic planning, implementation, and scorecarding system. Simple yet powerful second-generation balanced scorecards depict the organization's strategy through a series of strategy maps and scorecards…

Chromatographic matrix based on hydrogel-coated reticulated polyurethane foams, prepared by gamma irradiation

NASA Astrophysics Data System (ADS)

Sánchez, Mirna L.; Giménez, Claudia Y.; Delgado, Juan F.; Martínez, Leandro J.; Grasselli, Mariano

2017-12-01

Novel chromatographic materials for protein purification with high adsorption capacity and fouling resistance are highly demanded to improve downstream processes. Here, we describe a novel adsorptive material based on reticulated polyurethane foam (rPUF) coated with a functional hydrogel layer. rPUF provides physical rigidity through its macroscopic structure, whereas the hydrogel layer provides capacity to adsorb proteins by specific interactions. The hydrogel coating process was performed by the dip-coating method, using a polyvinyl alcohol (PVA) solution. The PVA hydrogel was linked to the rPUF material by using a radiation-induced crosslinking process in aqueous ethanol solution. The ethanol in the solvent mixture allowed a balance between PVA swelling and PVA dissolution during the irradiation step. The resulting material showed higher thermal stability than the non-irradiated one. In addition, a simultaneous radiation-induced grafting polymerization (SRIGP) was done by simple addition of glycidyl methacrylate monomer into the irradiation solution. In a further step, sulfonic ligands were included specifically in the hydrogel layer, which contained around 200% of PVA respect to the original rPUF. Materials were characterized by FT-IR, thermogravimetric analysis, SEM microscopy and EDX analysis. The cation-exchange rPUF material was functionally characterized by the Langmuir isotherm and a dynamic adsorption experiment to analyze the chromatographic properties for protein purification processes.

Mass, energy and material balances of SRF production process. Part 1: SRF produced from commercial and industrial waste.

PubMed

Nasrullah, Muhammad; Vainikka, Pasi; Hannula, Janne; Hurme, Markku; Kärki, Janne

2014-08-01

This paper presents the mass, energy and material balances of a solid recovered fuel (SRF) production process. The SRF is produced from commercial and industrial waste (C&IW) through mechanical treatment (MT). In this work various streams of material produced in SRF production process are analyzed for their proximate and ultimate analysis. Based on this analysis and composition of process streams their mass, energy and material balances are established for SRF production process. Here mass balance describes the overall mass flow of input waste material in the various output streams, whereas material balance describes the mass flow of components of input waste stream (such as paper and cardboard, wood, plastic (soft), plastic (hard), textile and rubber) in the various output streams of SRF production process. A commercial scale experimental campaign was conducted on an MT waste sorting plant to produce SRF from C&IW. All the process streams (input and output) produced in this MT plant were sampled and treated according to the CEN standard methods for SRF: EN 15442 and EN 15443. The results from the mass balance of SRF production process showed that of the total input C&IW material to MT waste sorting plant, 62% was recovered in the form of SRF, 4% as ferrous metal, 1% as non-ferrous metal and 21% was sorted out as reject material, 11.6% as fine fraction, and 0.4% as heavy fraction. The energy flow balance in various process streams of this SRF production process showed that of the total input energy content of C&IW to MT plant, 75% energy was recovered in the form of SRF, 20% belonged to the reject material stream and rest 5% belonged with the streams of fine fraction and heavy fraction. In the material balances, mass fractions of plastic (soft), plastic (hard), paper and cardboard and wood recovered in the SRF stream were 88%, 70%, 72% and 60% respectively of their input masses to MT plant. A high mass fraction of plastic (PVC), rubber material and non-combustibles (such as stone/rock and glass particles), was found in the reject material stream. Copyright © 2014 Elsevier Ltd. All rights reserved.

Beam walking can detect differences in walking balance proficiency across a range of sensorimotor abilities.

PubMed

Sawers, Andrew; Ting, Lena H

2015-02-01

The ability to quantify differences in walking balance proficiency is critical to curbing the rising health and financial costs of falls. Current laboratory-based approaches typically focus on successful recovery of balance while clinical instruments often pose little difficulty for all but the most impaired patients. Rarely do they test motor behaviors of sufficient difficulty to evoke failures in balance control limiting their ability to quantify balance proficiency. Our objective was to test whether a simple beam-walking task could quantify differences in walking balance proficiency across a range of sensorimotor abilities. Ten experts, ten novices, and five individuals with transtibial limb loss performed six walking trials across three different width beams. Walking balance proficiency was quantified as the ratio of distance walked to total possible distance. Balance proficiency was not significantly different between cohorts on the wide-beam, but clear differences between cohorts on the mid and narrow-beams were identified. Experts walked a greater distance than novices on the mid-beam (average of 3.63±0.04m verus 2.70±0.21m out of 3.66m; p=0.009), and novices walked further than amputees (1.52±0.20m; p=0.03). Amputees were unable to walk on the narrow-beam, while experts walked further (3.07±0.14m) than novices (1.55±0.26m; p=0.0005). A simple beam-walking task and an easily collected measure of distance traveled detected differences in walking balance proficiency across sensorimotor abilities. This approach provides a means to safely study and evaluate successes and failures in walking balance in the clinic or lab. It may prove useful in identifying mechanisms underlying falls versus fall recoveries. Copyright © 2015 Elsevier B.V. All rights reserved.

THE WATER BALANCE OF THE SUSQUEHANNA RIVER BASIN AND ITS RESPONSE TO CLIMATE CHANGE. (R824995)

EPA Science Inventory

Abstract

Historical precipitation, temperature and streamflow data for the Susquehanna River Basin (SRB) are analyzed with the objective of developing simple statistical and water balance models of streamflow at the watershed's outlet. Annual streamflow is highly corre...

ON EDGE CHIPPING TESTING AND SOME PERSONAL PERSPECTIVES ON THE STATE OF THE ART OF MECHANICAL TESTING

PubMed Central

Quinn, G. D.

2014-01-01

Objective The edge chipping test is used to measure the fracture resistance of dental restoration ceramics and resin composites. This paper focuses on the progress of evaluating chipping resistance of these materials and also on the progress of standardization of this test method. This paper also makes observations about the state of the art of mechanical testing of ceramic and composite restorative materials in general. Interlaboratory comparative studies (“round robins”) are recommended. Methods An edge chipping machine was used to evaluate dozens of materials including porcelains, glass ceramics, aluminas, zirconias, filled resin-composites, new hybrid ceramic-resin composites, laminated composite ceramics, and even polymethyl methacrylate based denture materials. Force versus distance data were collected over a broad range with different indenters. Several chipping resistance parameters were quantified. Results Older restorative materials such as feldspathic porcelains and veneering materials had limited chipping resistance, but more modern ceramics and filled composites show significant improvements. A yttria-partially stabilized zirconia had the greatest resistance to chipping. Much of the early work on edge chipping resistance of brittle materials emphasized linear force versus distance trends obtained with relatively blunt Rockwell C indenters. More recently, trends for dental restorative materials with alternative sharper indenters have been nonlinear. A new phenomenological model with a simple quadratic function fits all data exceptionally well. It is loosely based on an energy balance between indenter work and fracture and deformation energies in the chipped material. Significance Although a direct comparison of our laboratory scale tests on idealized simple geometries to clinical outcomes has not yet been done, anecdotal evidence suggests the procedure does produce clinically relevant rankings and outcomes. Despite the variations in the trends and indenters, comparisons between materials can easily be made by chipping convenient block-shaped specimens with sharp conical 120°, Vickers, or Rockwell C indenters at a defined edge distance of 0.5 mm. Broad distance ranges are recommended for trend evaluation. This work has provided important information for standardization. PMID:25244927

Analytical Modeling of Plasma Arc Cutting of Steel Plate

NASA Astrophysics Data System (ADS)

Cimbala, John; Fisher, Lance; Settles, Gary; Lillis, Milan

2000-11-01

A transferred-arc plasma torch cuts steel plate, and in the process ejects a molten stream of iron and ferrous oxides ("ejecta"). Under non-optimum conditions - especially during low speed cuts and/or small-radius corner cuts - "dross" is formed. Dross is re-solidified molten metal that sticks to the underside of the cut and renders it rough. The present research is an attempt to analytically model this process, with the goal of predicting dross formation. With the aid of experimental data, a control volume formulation is used in a steady frame of reference to predict the mass flow of molten material inside the cut. Although simple, the model is three-dimensional, can predict the shear stress driving the molten material in the direction of the plasma jet, and can predict the velocity of molten material exiting the bottom of the plate. In order to predict formation of dross, a momentum balance is performed on the flowing melt, considering the resisting viscous and surface tension forces. Preliminary results are promising, and provide a potential means of predicting dross formation without resorting to detailed computational analyses.

78 FR 23503 - Hazardous Materials; Temporary Reduction of Registration Fees

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-19

... the annual registration fee to account for any unexpended balance in the Hazardous Materials Emergency Preparedness (HMEP) Fund. Due to an unexpended balance that has accumulated in the Fund, PHMSA is lowering the... and thus draw down the unexpended balance as soon as possible, PHMSA is issuing this final rule...

A SIMPLE MODEL FOR THE UPTAKE, TRANSLOCATION, AND ACCUMULATION OF PERCHLORATE IN TOBACCO PLANTS

EPA Science Inventory

A simple mathematical model is being developed to describe the uptake, translocation, and accumulation of perchlorate in tobacco plants. The model defines a plant as a set of compartments, consisting of mass balance differential equations and plant-specific physiological paramet...

MO200: a model for evaluation safeguards through material accountability for a 200 tonne per year mixed-oxide fuel-rod fabrication plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sandborn, R.H.

1976-01-01

M0200, a computer simulation model, was used to investigate the safeguarding of plutonium dioxide. The computer program operating the model was constructed so that replicate runs could provide data for statistical analysis of the distributions of the randomized variables. The plant model was divided into material balance areas associated with definable unit processes. Indicators of plant operations studied were modified end-of-shift material balances, end-of-blend errors formed by closing material balances between blends, and cumulative sums of the differences between actual and expected performances. (auth)

From homeostasis to behavior: Balanced activity in an exploration of embodied dynamic environmental-neural interaction.

PubMed

Hellyer, Peter John; Clopath, Claudia; Kehagia, Angie A; Turkheimer, Federico E; Leech, Robert

2017-08-01

In recent years, there have been many computational simulations of spontaneous neural dynamics. Here, we describe a simple model of spontaneous neural dynamics that controls an agent moving in a simple virtual environment. These dynamics generate interesting brain-environment feedback interactions that rapidly destabilize neural and behavioral dynamics demonstrating the need for homeostatic mechanisms. We investigate roles for homeostatic plasticity both locally (local inhibition adjusting to balance excitatory input) as well as more globally (regional "task negative" activity that compensates for "task positive", sensory input in another region) balancing neural activity and leading to more stable behavior (trajectories through the environment). Our results suggest complementary functional roles for both local and macroscale mechanisms in maintaining neural and behavioral dynamics and a novel functional role for macroscopic "task-negative" patterns of activity (e.g., the default mode network).

A National Study of Work-Family Balance and Job Satisfaction among Agriculture Teachers

ERIC Educational Resources Information Center

Sorensen, Tyson J.; McKim, Aaron J.; Velez, Jonathan J.

2016-01-01

This national study sought to extend previous research on the work-family balance (WFB) ability of secondary school agriculture teachers. We utilized data from a simple random sample of agriculture teachers to explore the relationships between work and family characteristics, WFB ability, and job satisfaction. Work role characteristics of interest…

Writing by Number: Teaching Students to Read the Balance Sheet.

ERIC Educational Resources Information Center

Cross, Mary

1990-01-01

Describes an assignment in which students write a short memo report analyzing and comparing both what a company says in its annual report and what its balance sheet shows. Describes four simple mathematical formulas students can use to quickly diagnose a company's financial health. Appends a sample of the short report format. (RS)

A Balanced Approach to Managing Student Meal Charges

ERIC Educational Resources Information Center

Frye, Lisa K.

2012-01-01

As with most things in life, managing student meal charges is all about balance. To be successful, the program needs to include a fair and reasonable policy, to serve nutritious and flavorful meals, and to include students as active stakeholders in the program. A plan that acknowledges simple forgetfulness, explains expectations of all…

Microprocessor-Controlled Laser Balancing System

NASA Technical Reports Server (NTRS)

Demuth, R. S.

1985-01-01

Material removed by laser action as part tested for balance. Directed by microprocessor, laser fires appropriate amount of pulses in correct locations to remove necessary amount of material. Operator and microprocessor software interact through video screen and keypad; no programing skills or unprompted system-control decisions required. System provides complete and accurate balancing in single load-and-spinup cycle.

10 CFR 75.8 - IAEA inspections.

Code of Federal Regulations, 2010 CFR

2010-01-01

... inspection at a facility, to: (1) Examine records kept under § 75.21; (2) Observe that the measurements of nuclear material at key measurement points for material balance accounting are representative; (3) Verify... samples at key measurement points for material balance accounting are taken in accordance with procedures...

Simple Library Bookkeeping.

ERIC Educational Resources Information Center

Hoffman, Herbert H.

A simple and cheap manual double entry continuous transaction posting system with running balances is developed for bookkeeping by small libraries. A very small library may operate without any system of fiscal control but when a library's budget approaches three figures, some kind of bookkeeping must be introduced. To maintain control over his…

Amount of balance necessary for the independence of transfer and stair-climbing in stroke inpatients.

PubMed

Fujita, Takaaki; Sato, Atsushi; Ohashi, Yuji; Nishiyama, Kazutaka; Ohashi, Takuro; Yamane, Kazuhiro; Yamamoto, Yuichi; Tsuchiya, Kenji; Otsuki, Koji; Tozato, Fusae

2018-05-01

The purpose of this study was to clarify the amount of balance necessary for the independence of transfer and stair-climbing in stroke patients. This study included 111 stroke inpatients. Simple and multiple regression analyses were conducted to establish the association between the FIM ® instrument scores for transfer or stair-climbing and Berg Balance Scale. Furthermore, receiver operating characteristic curves were used to elucidate the amount of balance necessary for the independence of transfer and stair-climbing. Simple and multiple regression analyses showed that the FIM ® instrument scores for transfer and stair-climbing were strongly associated with Berg Balance Scale. On comparison of the independent and supervision-dependent groups, Berg Balance Scale cut-off values for transfer and stair-climbing were 41/40 and 54/53 points, respectively. On comparison of the independent-supervision and dependent groups, the cut-off values for transfer and stair-climbing were 30/29 and 41/40 points, respectively. The calculated cut-off values indicated the amount of balance necessary for the independence of transfer and stair-climbing, with and without supervision, in stroke patients. Berg Balance Scale has a good discriminatory ability and cut-off values are clinically useful to determine the appropriate independence levels of transfer and stair-climbing in hospital wards. Implications for rehabilitation The Berg Balance Scale's (BBS) strong association with transfer and stair-climbing independence and performance indicates that establishing cut-off values is vitally important for the established use of the BBS clinically. The cut-off values calculated herein accurately demonstrate the level of balance necessary for transfer and stair-climbing independence, with and without supervision, in stroke patients. These criteria should be employed clinically for determining the level of independence for transfer and stair-climbing as well as for setting balance training goals aimed at improving transfer and stair-climbing.

Evaluating MC&A effectiveness to verify the presence of nuclear materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dawson, P. G.; Morzinski, J. A.; Ostenak, Carl A.

Traditional materials accounting is focused exclusively on the material balance area (MBA), and involves periodically closing a material balance based on accountability measurements conducted during a physical inventory. In contrast, the physical inventory for Los Alamos National Laboratory's near-real-time accounting system is established around processes and looks more like an item inventory. That is, the intent is not to measure material for accounting purposes, since materials have already been measured in the normal course of daily operations. A given unit process operates many times over the course of a material balance period. The product of a given unit process maymore » move for processing within another unit process in the same MBA or may be transferred out of the MBA. Since few materials are unmeasured the physical inventory for a near-real-time process area looks more like an item inventory. Thus, the intent of the physical inventory is to locate the materials on the books and verify information about the materials contained in the books. Closing a materials balance for such an area is a matter of summing all the individual mass balances for the batches processed by all unit processes in the MBA. Additionally, performance parameters are established to measure the program's effectiveness. Program effectiveness for verifying the presence of nuclear material is required to be equal to or greater than a prescribed performance level, process measurements must be within established precision and accuracy values, physical inventory results meet or exceed performance requirements, and inventory differences are less than a target/goal quantity. This approach exceeds DOE established accounting and physical inventory program requirements. Hence, LANL is committed to this approach and to seeking opportunities for further improvement through integrated technologies. This paper will provide a detailed description of this evaluation process.« less

CARE AND FEEDING OF FROGS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pan, Margaret; Chiang, Eugene, E-mail: mpan@astro.berkeley.edu

2012-01-15

'Propellers' are features in Saturn's A ring associated with moonlets that open partial gaps. They exhibit non-Keplerian motion (Tiscareno et al.); the longitude residuals of the best-observed propeller, 'Bleriot', appear consistent with a sinusoid of period {approx}4 years. Pan and Chiang proposed that propeller moonlets librate in 'frog resonances' with co-orbiting ring material. By analogy with the restricted three-body problem, they treated the co-orbital material as stationary in the rotating frame and neglected non-co-orbital material. Here we use simple numerical experiments to extend the frog model, including feedback due to the gap's motion, and drag associated with the Lindblad diskmore » torques that cause Type I migration. Because the moonlet creates the gap, we expect the gap centroid to track the moonlet, but only after a time delay t{sub delay}, the time for a ring particle to travel from conjunction with the moonlet to the end of the gap. We find that frog librations can persist only if t{sub delay} exceeds the frog libration period P{sub lib}, and if damping from Lindblad torques balances driving from co-orbital torques. If t{sub delay} << Pl{sub ib}, then the libration amplitude damps to zero. In the case of Bleriot, the frog resonance model can reproduce the observed libration period P{sub lib} {approx_equal} 4 yr. However, our simple feedback prescription suggests that Bleriot's t{sub delay} {approx} 0.01P{sub lib}, which is inconsistent with the observed libration amplitude of 260 km. We urge more accurate treatments of feedback to test the assumptions of our toy models.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wollaber, Allan Benton; Park, HyeongKae; Lowrie, Robert Byron

Recent efforts at Los Alamos National Laboratory to develop a moment-based, scale-bridging [or high-order (HO)–low-order (LO)] algorithm for solving large varieties of the transport (kinetic) systems have shown promising results. A part of our ongoing effort is incorporating this methodology into the framework of the Eulerian Applications Project to achieve algorithmic acceleration of radiationhydrodynamics simulations in production software. By starting from the thermal radiative transfer equations with a simple material-motion correction, we derive a discretely consistent energy balance equation (LO equation). We demonstrate that the corresponding LO system for the Monte Carlo HO solver is closely related to the originalmore » LO system without material-motion corrections. We test the implementation on a radiative shock problem and show consistency between the energy densities and temperatures in the HO and LO solutions as well as agreement with the semianalytic solution. We also test the approach on a more challenging two-dimensional problem and demonstrate accuracy enhancements and algorithmic speedups. This paper extends a recent conference paper by including multigroup effects.« less

Long-term Evaluation of Landuse Changes On Landscape Water Balance - A Case Study From North-east Germany

NASA Astrophysics Data System (ADS)

Wegehenkel, M.

In this paper, long-term effects of different afforestation scenarios on landscape wa- ter balance will be analyzed taking into account the results of a regional case study. This analysis is based on using a GIS-coupled simulation model for the the spatially distributed calculation of water balance.For this purpose, the modelling system THE- SEUS with a simple GIS-interface will be used. To take into account the special case of change in forest cover proportion, THESEUS was enhanced with a simple for- est growth model. In the regional case study, model runs will be performed using a detailed spatial data set from North-East Germany. This data set covers a mesoscale catchment located at the moraine landscape of North-East Germany. Based on this data set, the influence of the actual landuse and of different landuse change scenarios on water balance dynamics will be investigated taking into account the spatial distributed modelling results from THESEUS. The model was tested using different experimen- tal data sets from field plots as well as obsverded catchment discharge. Additionally to such convential validation techniques, remote sensing data were used to check the simulated regional distribution of water balance components like evapotranspiration in the catchment.

A Simple Watt Balance for the Absolute Determination of Mass

ERIC Educational Resources Information Center

Quinn, Terry; Quinn, Lucas; Davis, Richard

2013-01-01

A watt balance is an electromechanical device that allows a mass to be determined in terms of measurable electrical and mechanical quantities, themselves traceable to the fundamental constants of physics. International plans are well advanced to redefine the unit of mass, the kilogram, in terms of a fixed numerical value for the Planck constant. A…

A Measurement of the Force between Two Current-Carrying Wires

ERIC Educational Resources Information Center

Straulino, S.; Cartacci, A.

2014-01-01

The measurement of the force acting between two parallel, current-carrying wires is known as Ampère's experiment. A mechanical balance was historically employed to measure that force. We report a simple experiment based on an electronic precision balance that is useful in clearly showing students the existence of this interaction and how to…

How to Design and Present Texts to Cultivate Balanced Regional Images in Geography Education

ERIC Educational Resources Information Center

Lee, Dong-Min; Ryu, Jaemyong

2013-01-01

This article examines possibilities associated with the cultivation of balanced regional images via the use of simple methods. Two experiments based on the primacy effect and the painting picture rule, or visual depiction of regions, were conducted. The results show significant differences in the formation of regional images. More specifically,…

Effect of the shell material and confinement type on the conversion efficiency of core/shell quantum dot nanocrystal solar cells

NASA Astrophysics Data System (ADS)

Sahin, Mehmet

2018-05-01

In this study, the effects of the shell material and confinement type on the conversion efficiency of core/shell quantum dot nanocrystal (QDNC) solar cells have been investigated in detail. For this purpose, the conventional, i.e. original, detailed balance model, developed by Shockley and Queisser to calculate an upper limit for the conversion efficiency of silicon p–n junction solar cells, is modified in a simple and effective way to calculate the conversion efficiency of core/shell QDNC solar cells. Since the existing model relies on the gap energy () of the solar cell, it does not make an estimation about the effect of QDNC materials on the efficiency of the solar cells, and gives the same efficiency values for several QDNC solar cells with the same . The proposed modification, however, estimates a conversion efficiency in relation to the material properties and also the confinement type of the QDNCs. The results of the modified model show that, in contrast to the original one, the conversion efficiencies of different QDNC solar cells, even if they have the same , become different depending upon the confinement type and shell material of the core/shell QDNCs, and this is crucial in the design and fabrication of the new generation solar cells to predict the confinement type and also appropriate QDNC materials for better efficiency.

Solar, Install, Mount, Production, Labor, Equipment Balance of Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gentry, Russell; Al-Haddad, Tristan; Valdes, Francisco

2015-08-27

The GTRI led project team in partnership with the DOE, universities, and numerous industry leaders, have advanced the mission of the DOE EERE, the Solar Energy Technologies Program, and the SunShot Initiative by accelerating the research, development, and demonstration of solar PV technologies that provide Extreme Balance of Systems Cost Reductions (BOS-X). The research produced 132 design concepts, resulting in 19 invention disclosures, five patent applications, four 90% pre-commercial designs, and three licensed technologies. Technology practice rights were obtained by an industry partner, and a new solar commercial start-up company was launched in Atlanta as a result of this project.more » Innovations in residential, commercial, and utility scale balance of systems technologies were realized through an unprecedented multi-disciplinary university/industry partnership with over 50 students and 24 faculty members that produced 18 technical publications, a PhD thesis, and two commercially deployed operating prototypes. The technical effectiveness and economic feasibility of the multidisciplinary systems based approach executed by the project team was realized through 1) a comprehensive evaluation of industry, regulatory, and public stakeholder requirements; 2) numerous industry/student/faculty engagements in design studios, technical conferences, and at solar PV installation sites; 3) time and motion studies with domain experts that provided technical data and costs for each phase and component of the solar PV installation processes; 4) extensive wind tunnel and systems engineering modeling; and 5) design, construction, and demonstration of the selected technologies in the field at high profile sites in Atlanta. The SIMPLE BOS project has benefitted the public in the following ways: • Workforce development: The launch of a start-up company to commercialize the DOE funded SIMPLE BoS designs has directly created 9 new jobs in the State of Georgia. As of November 2014, the Georgia solar industry employs 2,890 solar workers, representing a 12.8% growth in employment over 2013 (Solar Jobs Census, 2014). • Growth of the solar industry: The DOE SIMPLE BoS SunShot Award to GTARC accelerated the growth of the solar industry in Georgia, due to the national publicity of the award and the engagement of numerous solar PV manufacturers, designers, and installers on the SIMPLE BoS project. In 2011 less than 50 megawatts of solar PV capacity existed in Georgia; by 2016 Georgia may reach nearly 800 MW of total approved solar capacity with the 2012 Georgia Power Advanced Solar Initiative. • Technical outreach and publications: Georgia Tech has participated in numerous technical symposiums, technology demonstrations, campus solar PV tours, and produced 18 publications for the solar industry and general public. • Cost reductions for consumers: The SIMPLE BoS pre-commercial systems and discoveries enable cost reductions of 50% or more in labor and materials for residential, commercial and utility scale PV installations.« less

ZIMOD: A Simple Computer Model of the Zimbabwean Economy.

ERIC Educational Resources Information Center

Knox, Jon; And Others

1988-01-01

This paper describes a rationale for the construction and use of a simple consistency model of the Zimbabwean economy that incorporates an input-output matrix. The model is designed to investigate alternative industrial strategies and their consequences for the balance of payments, consumption, and overall gross domestic product growth for a…

77 FR 66566 - Airworthiness Directives; Hawker Beechcraft Corporation

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-06

... elevator balance weights becoming loose or failing because the balance weight material was under strength... balance weights and replacement of defective elevator balance weights. We are proposing this AD to correct.... Discussion We received reports of elevator balance weights becoming loose or failing on Hawker Beechcraft...

Analysis of an algae-based CELSS. I - Model development

NASA Technical Reports Server (NTRS)

Holtzapple, Mark T.; Little, Frank E.; Makela, Merry E.; Patterson, C. O.

1989-01-01

A steady state chemical model and computer program have been developed for a life support system and applied to trade-off studies. The model is based on human demand for food and oxygen determined from crew metabolic needs. The model includes modules for water recycle, waste treatment, CO2 removal and treatment, and food production. The computer program calculates rates of use and material balance for food, O2, the recycle of human waste and trash, H2O, N2, and food production/supply. A simple noniterative solution for the model has been developed using the steady state rate equations for the chemical reactions. The model and program have been used in system sizing and subsystem trade-off studies of a partially closed life support system.

Analysis of an algae-based CELSS. Part 1: model development

NASA Technical Reports Server (NTRS)

Holtzapple, M. T.; Little, F. E.; Makela, M. E.; Patterson, C. O.

1989-01-01

A steady state chemical model and computer program have been developed for a life support system and applied to trade-off studies. The model is based on human demand for food and oxygen determined from crew metabolic needs. The model includes modules for water recycle, waste treatment, CO2 removal and treatment, and food production. The computer program calculates rates of use and material balance for food. O2, the recycle of human waste and trash, H2O, N2, and food production supply. A simple non-iterative solution for the model has been developed using the steady state rate equations for the chemical reactions. The model and program have been used in system sizing and subsystem trade-off studies of a partially closed life support system.

Tunable rotating-mode density measurement using magnetic levitation

NASA Astrophysics Data System (ADS)

Gao, Qiu-Hua; Zhang, Wen-Ming; Zou, Hong-Xiang; Liu, Feng-Rui; Li, Wen-Bo; Peng, Zhi-Ke; Meng, Guang

2018-04-01

In this letter, a density measurement method by magnetic levitation using the rotation mechanism is presented. By rotating the entire magnetic levitation device that consists of four identical magnets, the horizontal centrifugal force and gravity can be balanced by the magnetic forces in the x-direction and the z-direction, respectively. The controllable magnified centripetal acceleration is investigated as a means to improve the measurement sensitivity without destabilization. Theoretical and experimental results show that the density measurement method can be flexible in characterizing small differences in density by tuning the eccentric distance or rotating speed. The rotating-mode density measurement method using magnetic levitation has prospects of providing an operationally simple way in separations and quality control of objects with arbitrary shapes in materials science and industrial fields.

An Experimental Investigation of Sewage Sludge Gasification in a Fluidized Bed Reactor

PubMed Central

Calvo, L. F.; García, A. I.; Otero, M.

2013-01-01

The gasification of sewage sludge was carried out in a simple atmospheric fluidized bed gasifier. Flow and fuel feed rate were adjusted for experimentally obtaining an air mass : fuel mass ratio (A/F) of 0.2 < A/F < 0.4. Fuel characterization, mass and power balances, produced gas composition, gas phase alkali and ammonia, tar concentration, agglomeration tendencies, and gas efficiencies were assessed. Although accumulation of material inside the reactor was a main problem, this was avoided by removing and adding bed media along gasification. This allowed improving the process heat transfer and, therefore, gasification efficiency. The heating value of the produced gas was 8.4 MJ/Nm, attaining a hot gas efficiency of 70% and a cold gas efficiency of 57%. PMID:24453863

A Wireless Object Location Detector Enabling People with Developmental Disabilities to Control Environmental Stimulation through Simple Occupational Activities with Nintendo Wii Balance Boards

ERIC Educational Resources Information Center

Shih, Ching-Hsiang; Chang, Man-Ling

2012-01-01

The latest researches have adopted software technology, turning the Nintendo Wii Balance Board into a high performance standing location detector with a newly developed standing location detection program (SLDP). This study extended SLDP functionality to assess whether two people with developmental disabilities would be able to actively perform…

Balance and Gait Impairment: Sensor-Based Assessment for Patients With Peripheral Neuropathy.

PubMed

Campbell, Grace; Skubic, Marjorie A

2018-06-01

Individuals with peripheral neuropathy (PN) frequently experience balance and gait impairments that can lead to poor physical function, falls, and injury. Nurses are aware that patients with cancer experience balance and gait impairments but are unsure of optimal assessment and management strategies. This article reviews options for balance and gait assessment for patients diagnosed with cancer experiencing PN, describes advantages and limitations of the various options, and highlights innovative, clinically feasible technologies to improve clinical assessment and management. The literature was reviewed to identify and assess the gold standard quantitative measures for assessing balance and gait. Gold standard quantitative measures are burdensome for patients and not often used in clinical practice. Sensor-based technologies improve balance and gait assessment options by calculating precise impairment measures during performance of simple clinical tests at the point of care.

EVALUATING MC AND A EFFECTIVENESS TO VERIFY THE PRESENCE OF NUCLEAR MATERIALS

DOE Office of Scientific and Technical Information (OSTI.GOV)

P. G. DAWSON; J. A MORZINSKI; ET AL

Traditional materials accounting is focused exclusively on the material balance area (MBA), and involves periodically closing a material balance based on accountability measurements conducted during a physical inventory. In contrast, the physical inventory for Los Alamos National Laboratory's near-real-time accounting system is established around processes and looks more like an item inventory. That is, the intent is not to measure material for accounting purposes, since materials have already been measured in the normal course of daily operations. A given unit process operates many times over the course of a material balance period. The product of a given unit process maymore » move for processing within another unit process in the same MBA or may be transferred out of the MBA. Since few materials are unmeasured the physical inventory for a near-real-time process area looks more like an item inventory. Thus, the intent of the physical inventory is to locate the materials on the books and verify information about the materials contained in the books. Closing a materials balance for such an area is a matter of summing all the individual mass balances for the batches processed by all unit processes in the MBA. Additionally, performance parameters are established to measure the program's effectiveness. Program effectiveness for verifying the presence of nuclear material is required to be equal to or greater than a prescribed performance level, process measurements must be within established precision and accuracy values, physical inventory results meet or exceed performance requirements, and inventory differences are less than a target/goal quantity. This approach exceeds DOE established accounting and physical inventory program requirements. Hence, LANL is committed to this approach and to seeking opportunities for further improvement through integrated technologies. This paper will provide a detailed description of this evaluation process.« less

The Subjective Visual Vertical: Validation of a Simple Test

ERIC Educational Resources Information Center

Tesio, Luigi; Longo, Stefano; Rota, Viviana

2011-01-01

The study sought to provide norms for a simple test of visual perception of verticality (subjective visual vertical). The study was designed as a cohort study with a balanced design. The setting was the Rehabilitation Department of a University Hospital. Twenty-two healthy adults, of 23-58 years, 11 men (three left handed) and 11 women (three left…

Stoichiometric balance of protein copy numbers is measurable and functionally significant in a protein-protein interaction network for yeast endocytosis

PubMed Central

2018-01-01

Stoichiometric balance, or dosage balance, implies that proteins that are subunits of obligate complexes (e.g. the ribosome) should have copy numbers expressed to match their stoichiometry in that complex. Establishing balance (or imbalance) is an important tool for inferring subunit function and assembly bottlenecks. We show here that these correlations in protein copy numbers can extend beyond complex subunits to larger protein-protein interactions networks (PPIN) involving a range of reversible binding interactions. We develop a simple method for quantifying balance in any interface-resolved PPINs based on network structure and experimentally observed protein copy numbers. By analyzing such a network for the clathrin-mediated endocytosis (CME) system in yeast, we found that the real protein copy numbers were significantly more balanced in relation to their binding partners compared to randomly sampled sets of yeast copy numbers. The observed balance is not perfect, highlighting both under and overexpressed proteins. We evaluate the potential cost and benefits of imbalance using two criteria. First, a potential cost to imbalance is that ‘leftover’ proteins without remaining functional partners are free to misinteract. We systematically quantify how this misinteraction cost is most dangerous for strong-binding protein interactions and for network topologies observed in biological PPINs. Second, a more direct consequence of imbalance is that the formation of specific functional complexes depends on relative copy numbers. We therefore construct simple kinetic models of two sub-networks in the CME network to assess multi-protein assembly of the ARP2/3 complex and a minimal, nine-protein clathrin-coated vesicle forming module. We find that the observed, imperfectly balanced copy numbers are less effective than balanced copy numbers in producing fast and complete multi-protein assemblies. However, we speculate that strategic imbalance in the vesicle forming module allows cells to tune where endocytosis occurs, providing sensitive control over cargo uptake via clathrin-coated vesicles. PMID:29518071

Stoichiometric balance of protein copy numbers is measurable and functionally significant in a protein-protein interaction network for yeast endocytosis.

PubMed

Holland, David O; Johnson, Margaret E

2018-03-01

Stoichiometric balance, or dosage balance, implies that proteins that are subunits of obligate complexes (e.g. the ribosome) should have copy numbers expressed to match their stoichiometry in that complex. Establishing balance (or imbalance) is an important tool for inferring subunit function and assembly bottlenecks. We show here that these correlations in protein copy numbers can extend beyond complex subunits to larger protein-protein interactions networks (PPIN) involving a range of reversible binding interactions. We develop a simple method for quantifying balance in any interface-resolved PPINs based on network structure and experimentally observed protein copy numbers. By analyzing such a network for the clathrin-mediated endocytosis (CME) system in yeast, we found that the real protein copy numbers were significantly more balanced in relation to their binding partners compared to randomly sampled sets of yeast copy numbers. The observed balance is not perfect, highlighting both under and overexpressed proteins. We evaluate the potential cost and benefits of imbalance using two criteria. First, a potential cost to imbalance is that 'leftover' proteins without remaining functional partners are free to misinteract. We systematically quantify how this misinteraction cost is most dangerous for strong-binding protein interactions and for network topologies observed in biological PPINs. Second, a more direct consequence of imbalance is that the formation of specific functional complexes depends on relative copy numbers. We therefore construct simple kinetic models of two sub-networks in the CME network to assess multi-protein assembly of the ARP2/3 complex and a minimal, nine-protein clathrin-coated vesicle forming module. We find that the observed, imperfectly balanced copy numbers are less effective than balanced copy numbers in producing fast and complete multi-protein assemblies. However, we speculate that strategic imbalance in the vesicle forming module allows cells to tune where endocytosis occurs, providing sensitive control over cargo uptake via clathrin-coated vesicles.

Shaping up synthetic cells

NASA Astrophysics Data System (ADS)

Mulla, Yuval; Aufderhorst-Roberts, Anders; Koenderink, Gijsje H.

2018-07-01

How do the cells in our body reconfigure their shape to achieve complex tasks like migration and mitosis, yet maintain their shape in response to forces exerted by, for instance, blood flow and muscle action? Cell shape control is defined by a delicate mechanical balance between active force generation and passive material properties of the plasma membrane and the cytoskeleton. The cytoskeleton forms a space-spanning fibrous network comprising three subsystems: actin, microtubules and intermediate filaments. Bottom-up reconstitution of minimal synthetic cells where these cytoskeletal subsystems are encapsulated inside a lipid vesicle provides a powerful avenue to dissect the force balance that governs cell shape control. Although encapsulation is technically demanding, a steady stream of advances in this technique has made the reconstitution of shape-changing minimal cells increasingly feasible. In this topical review we provide a route-map of the recent advances in cytoskeletal encapsulation techniques and outline recent reports that demonstrate shape change phenomena in simple biomimetic vesicle systems. We end with an outlook toward the next steps required to achieve more complex shape changes with the ultimate aim of building a fully functional synthetic cell with the capability to autonomously grow, divide and move.

Elimination of initial stress-induced curvature in a micromachined bi-material composite-layered cantilever

NASA Astrophysics Data System (ADS)

Liu, Ruiwen; Jiao, Binbin; Kong, Yanmei; Li, Zhigang; Shang, Haiping; Lu, Dike; Gao, Chaoqun; Chen, Dapeng

2013-09-01

Micro-devices with a bi-material-cantilever (BMC) commonly suffer initial curvature due to the mismatch of residual stress. Traditional corrective methods to reduce the residual stress mismatch generally involve the development of different material deposition recipes. In this paper, a new method for reducing residual stress mismatch in a BMC is proposed based on various previously developed deposition recipes. An initial material film is deposited using two or more developed deposition recipes. This first film is designed to introduce a stepped stress gradient, which is then balanced by overlapping a second material film on the first and using appropriate deposition recipes to form a nearly stress-balanced structure. A theoretical model is proposed based on both the moment balance principle and total equal strain at the interface of two adjacent layers. Experimental results and analytical models suggest that the proposed method is effective in producing multi-layer micro cantilevers that display balanced residual stresses. The method provides a generic solution to the problem of mismatched initial stresses which universally exists in micro-electro-mechanical systems (MEMS) devices based on a BMC. Moreover, the method can be incorporated into a MEMS design automation package for efficient design of various multiple material layer devices from MEMS material library and developed deposition recipes.

Evaporation estimation of rift valley lakes: comparison of models.

PubMed

Melesse, Assefa M; Abtew, Wossenu; Dessalegne, Tibebe

2009-01-01

Evapotranspiration (ET) accounts for a substantial amount of the water flux in the arid and semi-arid regions of the World. Accurate estimation of ET has been a challenge for hydrologists, mainly because of the spatiotemporal variability of the environmental and physical parameters governing the latent heat flux. In addition, most available ET models depend on intensive meteorological information for ET estimation. Such data are not available at the desired spatial and temporal scales in less developed and remote parts of the world. This limitation has necessitated the development of simple models that are less data intensive and provide ET estimates with acceptable level of accuracy. Remote sensing approach can also be applied to large areas where meteorological data are not available and field scale data collection is costly, time consuming and difficult. In areas like the Rift Valley regions of Ethiopia, the applicability of the Simple Method (Abtew Method) of lake evaporation estimation and surface energy balance approach using remote sensing was studied. The Simple Method and a remote sensing-based lake evaporation estimates were compared to the Penman, Energy balance, Pan, Radiation and Complementary Relationship Lake Evaporation (CRLE) methods applied in the region. Results indicate a good correspondence of the models outputs to that of the above methods. Comparison of the 1986 and 2000 monthly lake ET from the Landsat images to the Simple and Penman Methods show that the remote sensing and surface energy balance approach is promising for large scale applications to understand the spatial variation of the latent heat flux.

Paralleling power MOSFETs in their active region: Extended range of passively forced current sharing

NASA Technical Reports Server (NTRS)

Niedra, Janis M.

1989-01-01

A simple passive circuit that improves current balance in parallelled power MOSFETs that are not precisely matched and that are operated in their active region from a common gate drive are exhibited. A nonlinear circuit consisting of diodes and resistors generates the differential gate potential required to correct for unbalance while maintaining low losses over a range of current. Also application of a thin tape wound magnetic core to effect dynamic current balance is reviewed, and a simple theory is presented showing that for operation in the active region the branch currents tend to revert to their normal unbalanced values even if the core is not driven into saturation. Results of several comparative experiments are given.

Population Genetics of Three Dimensional Range Expansions

NASA Astrophysics Data System (ADS)

Lavrentovich, Maxim; Nelson, David

2014-03-01

We develop a simple model of genetic diversity in growing spherical cell clusters, where the growth is confined to the cluster surface. This kind of growth occurs in cells growing in soft agar, and can also serve as a simple model of avascular tumors. Mutation-selection balance in these radial expansions is strongly influenced by scaling near a neutral, voter model critical point and by the inflating frontier. We develop a scaling theory to describe how the dynamics of mutation-selection balance is cut off by inflation. Genetic drift, i.e., local fluctuations in the genetic diversity, also plays an important role, and can lead to the extinction even of selectively advantageous strains. We calculate this extinction probability, taking into account the effect of rough population frontiers.

A Planar Quasi-Static Constraint Mode Tire Model

DTIC Science & Technology

2015-07-10

strikes a balance between simple tire models that lack the fidelity to make accurate chassis load predictions and computationally intensive models that...strikes a balance between heuristic tire models (such as a linear point-follower) that lack the fidelity to make accurate chassis load predictions...UNCLASSIFIED: Distribution Statement A. Cleared for public release A PLANAR QUASI-STATIC CONSTRAINT MODE TIRE MODEL Rui Maa John B. Ferris

Nanoscale Charge Balancing Mechanism in Calcium-Silicate-Hydrate Gels: Novel Complex Disordered Materials from First-principles

NASA Astrophysics Data System (ADS)

Ozcelik, Ongun; White, Claire

Alkali-activated materials which have augmented chemical compositions as compared to ordinary Portland cement are sustainable technologies that have the potential to lower CO2 emissions associated with the construction industry. In particular, calcium-silicate-hydrate (C-S-H) gel is altered at the atomic scale due to changes in its chemical composition. Here, based on first-principles calculations, we predict a charge balancing mechanism at the molecular level in C-S-H gels when alkali atoms are introduced into their structure. This charge balancing process is responsible for the formation of novel structures which possess superior mechanical properties compared to their charge unbalanced counterparts. Different structural representations are obtained depending on the level of substitution and the degree of charge balancing incorporated in the structures. The impact of these charge balancing effects on the structures is assessed by analyzing their formation energies, local bonding environments, diffusion barriers and mechanical properties. These results provide information on the phase stability of alkali/aluminum containing C-S-H gels, shedding light on the fundamental mechanisms that play a crucial role in these complex disordered materials. We acknowledge funding from the Princeton Center for Complex Materials, a MRSEC supported by NSF.

Effects of Nesting Material on Energy Homeostasis in BALB/cAnNCrl, C57BL/6NCrl, and Crl:CD1(ICR) Mice Housed at 20 °C.

PubMed

Johnson, Jay S; Taylor, Daniel J; Green, Angela R; Gaskill, Brianna N

2017-05-01

Discrepancies exist between the preferred temperature range for mice (26 to 32 °C) and current recommendations (20 to 26 °C), which may alter metabolism and negatively affect studies using mice. Previous research indicates that nesting material can alleviate cold stress in mice; therefore, we sought to determine the effects of the amount of nesting material provided (0, 6, or 12 g) on heat energy loss and energy balance in 3 mouse strains housed at currently recommended temperatures during the daytime, a period of presumed inactivity. Groups of BALB/cAnNCrl, C57BL/6NCrl, and Crl:CD1(ICR) mice, balanced by strain and sex, were group-housed and provided 0, 6, or 12 g of nesting material. After a 3-d acclimation period, body weight was determined daily at 0800, food intake was determined at 0800 and 2000, and total heat production was evaluated from 0800 to 2000 on 4 consecutive days and used to calculate energy balance and the respiratory quotient. Although the amount of nesting material had no overall effect on food intake or heat production, mice provided 12 g of nesting material had greater weight gain than those given 0 or 6 g. This increase in body weight might have been due to improved energy balance, which was corroborated by an increased respiratory quotient in mice provided 12 g of nesting material. In summary, although heat production did not differ, providing 12 g of nesting material improved energy balance, likely leading to an increase in body weight during the 0800-2000 testing period.

The effects of salinity in the soil water balance: A Budyko's approach

NASA Astrophysics Data System (ADS)

Perri, S.; Viola, F.; Molini, A.

2017-12-01

Soil degradation and water scarcity pose important constraints on productivity and development of arid and semi-arid countries. Among the main causes of loss of soil fertility, aridification and soil salinization are deeply connected threats enhanced by climate change. Assessing water availability is fundamental for a large number of applications especially in arid regions. An approach often adopted to estimate the long-term rainfall partitioning into evapotranspiration and runoff is the Budyko's curve. However, the classical Budyko framework might not be able to properly reproduce the water balance in salt affected basins, especially under elevated soil salinization conditions. Salinity is a limiting factor for plant transpiration (as well as growth) affecting both short and long term soil moisture dynamics and ultimately the hydrologic balance. Soluble salts cause a reduction of soil water potential similar to the one arising from droughts, although plant adaptations to soil salinity show extremely different traits and can vary from species to species. In a similar context, the salt-tolerance plants are expected to control the amount of soil moisture lost to transpiration in saline soils, also because salinity reduces evaporation. We propose a simple framework to include the effects of salinization on the surface energy and water balance within a simple Budyko approach. By introducing the effects of salinity in the stochastic water balance we are able to include the influence of vegetation type (i.e. in terms of salt-tolerance) on evapotranspiration-runoff partitioning under different climatic conditions. The water balance components are thus compared to data obtained from arid salt-affected regions.

Thermal Characterization of the Air Force Institute of Technology Solar Simulation Thermal Vacuum Chamber

DTIC Science & Technology

2014-03-27

mass and surface area, Equation 12 demonstrates an energy balance for the material, assuming the rest of the surfaces of the material are isothermal...radiation in order to dissipate heat from 18 the spacecraft [8]. As discussed in the system thermal energy balance defined previously, emission of IR... energy balance calculations will be utilized. The Monte Carlo/Ray Trace Radiation Method The Monte Carlo/Ray Trace method is utilized in order to

A simple performance calculation method for LH2/LOX engines with different power cycles

NASA Technical Reports Server (NTRS)

Schmucker, R. H.

1973-01-01

A simple method for the calculation of the specific impulse of an engine with a gas generator cycle is presented. The solution is obtained by a power balance between turbine and pump. Approximate equations for the performance of the combustion products of LH2/LOX are derived. Performance results are compared with solutions of different engine types.

A Simple Model to Demonstrate the Balance of Forces at Functional Residual Capacity

ERIC Educational Resources Information Center

Kanthakumar, Praghalathan; Oommen, Vinay

2012-01-01

Numerous models have been constructed to aid teaching respiratory mechanics. A simple model using a syringe and a water-filled bottle has been described by Thomas Sherman to explain inspiration and expiration. The elastic recoil of the chest wall and lungs has been described using a coat hanger or by using rods and rubber bands. A more complex…

40 CFR 63.707 - Reporting requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

...(c)(1) (material balance calculation) shall include with the notification of compliance status required by § 63.9(h) the results of the initial material balance calculation. (e) The owner or operator... nonregenerative carbon adsorber and demonstrating initial compliance in accordance with § 63.705(c)(6) shall...

40 CFR 63.707 - Reporting requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

...(c)(1) (material balance calculation) shall include with the notification of compliance status required by § 63.9(h) the results of the initial material balance calculation. (e) The owner or operator... nonregenerative carbon adsorber and demonstrating initial compliance in accordance with § 63.705(c)(6) shall...

40 CFR 63.707 - Reporting requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

...(c)(1) (material balance calculation) shall include with the notification of compliance status required by § 63.9(h) the results of the initial material balance calculation. (e) The owner or operator... nonregenerative carbon adsorber and demonstrating initial compliance in accordance with § 63.705(c)(6) shall...

40 CFR 63.707 - Reporting requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

...(c)(1) (material balance calculation) shall include with the notification of compliance status required by § 63.9(h) the results of the initial material balance calculation. (e) The owner or operator... nonregenerative carbon adsorber and demonstrating initial compliance in accordance with § 63.705(c)(6) shall...

40 CFR 63.707 - Reporting requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

...(c)(1) (material balance calculation) shall include with the notification of compliance status required by § 63.9(h) the results of the initial material balance calculation. (e) The owner or operator... nonregenerative carbon adsorber and demonstrating initial compliance in accordance with § 63.705(c)(6) shall...

10 CFR 72.76 - Material status reports.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Commission a Material Balance Report and a Physical Inventory Listing Report as specified in the instructions... the licensee. Each report must be submitted within 60 days of the beginning of the physical inventory... Balance Reports and Physical Inventory Listing Reports at other times. Each licensee required to report...

Biodegradable and compostable alternatives to conventional plastics.

PubMed

Song, J H; Murphy, R J; Narayan, R; Davies, G B H

2009-07-27

Packaging waste forms a significant part of municipal solid waste and has caused increasing environmental concerns, resulting in a strengthening of various regulations aimed at reducing the amounts generated. Among other materials, a wide range of oil-based polymers is currently used in packaging applications. These are virtually all non-biodegradable, and some are difficult to recycle or reuse due to being complex composites having varying levels of contamination. Recently, significant progress has been made in the development of biodegradable plastics, largely from renewable natural resources, to produce biodegradable materials with similar functionality to that of oil-based polymers. The expansion in these bio-based materials has several potential benefits for greenhouse gas balances and other environmental impacts over whole life cycles and in the use of renewable, rather than finite resources. It is intended that use of biodegradable materials will contribute to sustainability and reduction in the environmental impact associated with disposal of oil-based polymers. The diversity of biodegradable materials and their varying properties makes it difficult to make simple, generic assessments such as biodegradable products are all 'good' or petrochemical-based products are all 'bad'. This paper discusses the potential impacts of biodegradable packaging materials and their waste management, particularly via composting. It presents the key issues that inform judgements of the benefits these materials have in relation to conventional, petrochemical-based counterparts. Specific examples are given from new research on biodegradability in simulated 'home' composting systems. It is the view of the authors that biodegradable packaging materials are most suitable for single-use disposable applications where the post-consumer waste can be locally composted.

Effect of the shell material and confinement type on the conversion efficiency of core/shell quantum dot nanocrystal solar cells.

PubMed

Sahin, Mehmet

2018-05-23

In this study, the effects of the shell material and confinement type on the conversion efficiency of core/shell quantum dot nanocrystal (QDNC) solar cells have been investigated in detail. For this purpose, the conventional, i.e. original, detailed balance model, developed by Shockley and Queisser to calculate an upper limit for the conversion efficiency of silicon p-n junction solar cells, is modified in a simple and effective way to calculate the conversion efficiency of core/shell QDNC solar cells. Since the existing model relies on the gap energy ([Formula: see text]) of the solar cell, it does not make an estimation about the effect of QDNC materials on the efficiency of the solar cells, and gives the same efficiency values for several QDNC solar cells with the same [Formula: see text]. The proposed modification, however, estimates a conversion efficiency in relation to the material properties and also the confinement type of the QDNCs. The results of the modified model show that, in contrast to the original one, the conversion efficiencies of different QDNC solar cells, even if they have the same [Formula: see text], become different depending upon the confinement type and shell material of the core/shell QDNCs, and this is crucial in the design and fabrication of the new generation solar cells to predict the confinement type and also appropriate QDNC materials for better efficiency.

Covariant balance laws in continua with microstructure

NASA Astrophysics Data System (ADS)

Yavari, Arash; Marsden, Jerrold E.

2009-02-01

The purpose of this paper is to extend the Green-Naghdi-Rivlin balance of energy method to continua with microstructure. The key idea is to replace the group of Galilean transformations with the group of diffeomorphisms of the ambient space. A key advantage is that one obtains in a natural way all the needed balance laws on both the macro and micro levels along with two Doyle-Erickson formulas. We model a structured continuum as a triplet of Riemannian manifolds: a material manifold, the ambient space manifold of material particles and a director field manifold. The Green-Naghdi-Rivlin theorem and its extensions for structured continua are critically reviewed. We show that when the ambient space is Euclidean and when the microstructure manifold is the tangent space of the ambient space manifold, postulating a single balance of energy law and its invariance under time-dependent isometries of the ambient space, one obtains conservation of mass, balances of linear and angular momenta but not a separate balance of linear momentum. We develop a covariant elasticity theory for structured continua by postulating that energy balance is invariant under time-dependent spatial diffeomorphisms of the ambient space, which in this case is the product of two Riemannian manifolds. We then introduce two types of constrained continua in which microstructure manifold is linked to the reference and ambient space manifolds. In the case when at every material point, the microstructure manifold is the tangent space of the ambient space manifold at the image of the material point, we show that the assumption of covariance leads to balances of linear and angular momenta with contributions from both forces and micro-forces along with two Doyle-Ericksen formulas. We show that generalized covariance leads to two balances of linear momentum and a single coupled balance of angular momentum. Using this theory, we covariantly obtain the balance laws for two specific examples, namely elastic solids with distributed voids and mixtures. Finally, the Lagrangian field theory of structured elasticity is revisited and a connection is made between covariance and Noether's theorem.

40 CFR 60.424 - Test methods and procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

... weigh scales, or the result of computations using a material balance, shall be used to determine the rate (P) of the ammonium sulfate production. If production rate is determined by material balance, the... combined feed stream flow rate to the ammonium crystallizer before the point where any recycle streams...

Reconstruction Era: Resources for a Balanced Approach.

ERIC Educational Resources Information Center

Seiter, David M.

1989-01-01

Lists instructional materials from the ERIC database that focus on the Reconstruction. Includes materials that present a balanced approach to this period of U.S. history. Offers documents concerned with Black education, the Freedmen's Bureau, the Indian Territory, textbook evaluation, Black women's education, and Reverend Moses Drury Hoge. (KO)

Multi-Plane High Speed Balancing Techniques and the Use of a High Specific Stiffness Ti-Borsic Material for Vibration Control.

DTIC Science & Technology

1980-02-01

maneuver conditions, and transmit the net axial thrust force between the turbine and fan sections due to pressure and aero dynamic gas loads . 49 Lm...stiffness composite material shaft. Both~~ balancing demonstration and the composite shaft design ad as their objective the management of small turbofan ...CONFIGURATIONS 99 LIST OF ILLUSTRATIONS Figure Title Page 1 High Speed Balancing Program Schedule 4 2 Teledyne CAE Model 471-11DX Turbofan Engine

Polarization-dependent optical reflection ultrasonic detection

NASA Astrophysics Data System (ADS)

Zhu, Xiaoyi; Huang, Zhiyu; Wang, Guohe; Li, Wenzhao; Li, Changhui

2017-03-01

Although ultrasound transducers based on commercial piezoelectric-material have been widely used, they generally have limited bandwidth centered at the resonant frequency. Currently, several pure-optical ultrasonic detection methods have gained increasing interest due to their wide bandwidth and high sensitivity. However, most of them require customized components (such as micro-ring, SPR, Fabry-Perot film, etc), which limit their broad implementations. In this study, we presented a simple pure-optical ultrasound detection method, called "Polarization-dependent Reflection Ultrasonic Detection" (PRUD). It detects the intensity difference between two polarization components of the probe beam that is modulated by ultrasound waves. PRUD detect the two components by using a balanced detector, which effectively suppressed much of the unwanted noise. We have achieved the sensitivity (noise equivalent pressure) to be 1.7kPa, and this can be further improved. In addition, like many other pure-optical ultrasonic detection methods, PRUD also has a flat and broad bandwidth from almost zero to over 100MHz. Besides theoretical analysis, we did a phantom study by imaging a tungsten filament to demonstrate the performance of PRUD. We believe this simple and economic method will attract both researchers and engineers in optical and ultrasound fields.

A Simple, Inexpensive Acoustic Levitation Apparatus

NASA Astrophysics Data System (ADS)

Schappe, R. Scott; Barbosa, Cinthya

2017-01-01

Acoustic levitation uses a resonant ultrasonic standing wave to suspend small objects; it is used in a variety of research disciplines, particularly in the study of phase transitions and materials susceptible to contamination, or as a stabilization mechanism in microgravity environments. The levitation equipment used for such research is quite costly; we wanted to develop a simple, inexpensive system to demonstrate this visually striking example of standing waves. A search of the literature produced only one article relevant to creating such an apparatus, but the authors' approach uses a test tube, which limits the access to the standing wave. Our apparatus, shown in Fig. 1, can levitate multiple small (1-2 mm) pieces of expanded polystyrene (Styrofoam) using components readily available to most instructors of introductory physics. Acoustic levitation occurs in small, stable equilibrium locations where the weight of the object is balanced by the acoustic radiation force created by an ultrasonic standing wave; these locations are slightly below the pressure nodes. The levitation process also creates a horizontal restoring force. Since the pressure nodes are also velocity antinodes, this transverse stability may be analogous to the effect of an upward air stream supporting a ball.

Understanding the role of electron and hole trions on current transport in aluminium tris(8-hydroxyquinoline) using organic magnetoresistance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Sijie; Gillin, W. P., E-mail: w.gillin@qmul.ac.uk; Materials Research Institute and School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS

The change in current through an organic light emitting diode (OLED) when it is placed in a magnetic field has been dubbed organic magnetoresistance and provides a means to understand the spin interactions that are occurring in working devices. Whilst there are a wide range of interactions that have been proposed to be the cause of the measured effects, there is still a need to identify their individual roles and in particular how they respond to an applied magnetic field. In this work, we investigate the effect of changing the balance of electron and hole injection in a simple aluminiummore » tris(8-hydroxyqinoline) based OLED and demonstrate that the triplet polaron interaction appears to be much stronger for electrons than for holes in this material.« less

Lagrangian formulation for penny-shaped and Perkins-Kern geometry models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, W.S.

1989-09-01

This paper discusses basic theories for vertical penny-shaped and Perkins-Kern (PK) geometry models developed with a Lagrangian formulation combined with a virtual-work analysis. The Lagrangian formulation yields a pair of nonlinear equations in R/sub f/ or L/sub f/ and b/sub f/, the fracture radius or length and half-width. By introduction of a virtual-work analysis, a simple equation is obtained that can be solved numerically. This equation is written in a form that can be used to determine fracture geometry when the fluid-loss coefficient of the fracturing fluid is known. Also, this equation, coupled with a material-balance equation after shut-in, canmore » be used to analyze pressure-decline data after shut-in to determine the effective fluid-loss coefficient and fracture geometry.« less

Multigroup Radiation-Hydrodynamics with a High-Order, Low-Order Method

DOE PAGES

Wollaber, Allan Benton; Park, HyeongKae; Lowrie, Robert Byron; ...

2016-12-09

Recent efforts at Los Alamos National Laboratory to develop a moment-based, scale-bridging [or high-order (HO)–low-order (LO)] algorithm for solving large varieties of the transport (kinetic) systems have shown promising results. A part of our ongoing effort is incorporating this methodology into the framework of the Eulerian Applications Project to achieve algorithmic acceleration of radiationhydrodynamics simulations in production software. By starting from the thermal radiative transfer equations with a simple material-motion correction, we derive a discretely consistent energy balance equation (LO equation). We demonstrate that the corresponding LO system for the Monte Carlo HO solver is closely related to the originalmore » LO system without material-motion corrections. We test the implementation on a radiative shock problem and show consistency between the energy densities and temperatures in the HO and LO solutions as well as agreement with the semianalytic solution. We also test the approach on a more challenging two-dimensional problem and demonstrate accuracy enhancements and algorithmic speedups. This paper extends a recent conference paper by including multigroup effects.« less

Non-linear optical measurement of the twist elastic constant in thermotropic and DNA lyotropic chiral nematics.

PubMed

Lucchetti, Liana; Fraccia, Tommaso P; Ciciulla, Fabrizio; Bellini, Tommaso

2017-07-10

Throughout the whole history of liquid crystals science, the balancing of intrinsic elasticity with coupling to external forces has been the key strategy for most application and investigation. While the coupling of the optical field to the nematic director is at the base of a wealth of thoroughly described optical effects, a significant variety of geometries and materials have not been considered yet. Here we show that by adopting a simple cell geometry and measuring the optically induced birefringence, we can readily extract the twist elastic coefficient K 22 of thermotropic and lyotropic chiral nematics (N*). The value of K 22 we obtain for chiral doped 5CB thermotropic N* well matches those reported in the literature. With this same strategy, we could determine for the first time K 22 of the N* phase of concentrated aqueous solutions of DNA oligomers, bypassing the limitations that so far prevented measuring the elastic constants of this class of liquid crystalline materials. The present study also enlightens the significant nonlinear optical response of DNA liquid crystals.

Functional materials discovery using energy-structure-function maps

NASA Astrophysics Data System (ADS)

Pulido, Angeles; Chen, Linjiang; Kaczorowski, Tomasz; Holden, Daniel; Little, Marc A.; Chong, Samantha Y.; Slater, Benjamin J.; McMahon, David P.; Bonillo, Baltasar; Stackhouse, Chloe J.; Stephenson, Andrew; Kane, Christopher M.; Clowes, Rob; Hasell, Tom; Cooper, Andrew I.; Day, Graeme M.

2017-03-01

Molecular crystals cannot be designed in the same manner as macroscopic objects, because they do not assemble according to simple, intuitive rules. Their structures result from the balance of many weak interactions, rather than from the strong and predictable bonding patterns found in metal-organic frameworks and covalent organic frameworks. Hence, design strategies that assume a topology or other structural blueprint will often fail. Here we combine computational crystal structure prediction and property prediction to build energy-structure-function maps that describe the possible structures and properties that are available to a candidate molecule. Using these maps, we identify a highly porous solid, which has the lowest density reported for a molecular crystal so far. Both the structure of the crystal and its physical properties, such as methane storage capacity and guest-molecule selectivity, are predicted using the molecular structure as the only input. More generally, energy-structure-function maps could be used to guide the experimental discovery of materials with any target function that can be calculated from predicted crystal structures, such as electronic structure or mechanical properties.

Functional materials discovery using energy-structure-function maps.

PubMed

Pulido, Angeles; Chen, Linjiang; Kaczorowski, Tomasz; Holden, Daniel; Little, Marc A; Chong, Samantha Y; Slater, Benjamin J; McMahon, David P; Bonillo, Baltasar; Stackhouse, Chloe J; Stephenson, Andrew; Kane, Christopher M; Clowes, Rob; Hasell, Tom; Cooper, Andrew I; Day, Graeme M

2017-03-30

Molecular crystals cannot be designed in the same manner as macroscopic objects, because they do not assemble according to simple, intuitive rules. Their structures result from the balance of many weak interactions, rather than from the strong and predictable bonding patterns found in metal-organic frameworks and covalent organic frameworks. Hence, design strategies that assume a topology or other structural blueprint will often fail. Here we combine computational crystal structure prediction and property prediction to build energy-structure-function maps that describe the possible structures and properties that are available to a candidate molecule. Using these maps, we identify a highly porous solid, which has the lowest density reported for a molecular crystal so far. Both the structure of the crystal and its physical properties, such as methane storage capacity and guest-molecule selectivity, are predicted using the molecular structure as the only input. More generally, energy-structure-function maps could be used to guide the experimental discovery of materials with any target function that can be calculated from predicted crystal structures, such as electronic structure or mechanical properties.

A new paradigm for human stick balancing: a suspended not an inverted pendulum.

PubMed

Lee, Kwee-Yum; O'Dwyer, Nicholas; Halaki, Mark; Smith, Richard

2012-09-01

We studied 14 skilled subjects balancing a stick (a television antenna, 52 cm, 34 g) on their middle fingertip. Comprehensive three-dimensional analyses revealed that the movement of the finger was 1.75 times that of the stick tip, such that the balanced stick behaved more like a normal noninverted pendulum than the inverted pendulum common to engineering models for stick balancing using motors. The average relation between the torque applied to the stick and its angle of deviation from the vertical was highly linear, consistent with simple harmonic motion. We observed clearly greater rotational movement of the stick in the anteroposterior plane than the mediolateral plane. Despite this magnitude difference, the duration of stick oscillatory cycles was very similar in both planes, again consistent with simple harmonic motion. The control parameter in balancing was the ratio of active torque applied to the stick relative to gravitational torque. It determined both the pivot point and oscillatory cycle period of the pendulum. The pivot point was located at the radius of gyration (about the centre of mass) of the stick from its centre of mass, showing that the subjects attuned to the gravitational dynamics and mass distribution of the stick. Hence, the key to controlling instability here was mastery of the physics of the unstable object. The radius of gyration may--similar to centre of mass--contribute to the kinesthesis of rotating limb segments and control of their gravitational dynamics.

Hidden Connections between Regression Models of Strain-Gage Balance Calibration Data

NASA Technical Reports Server (NTRS)

Ulbrich, Norbert

2013-01-01

Hidden connections between regression models of wind tunnel strain-gage balance calibration data are investigated. These connections become visible whenever balance calibration data is supplied in its design format and both the Iterative and Non-Iterative Method are used to process the data. First, it is shown how the regression coefficients of the fitted balance loads of a force balance can be approximated by using the corresponding regression coefficients of the fitted strain-gage outputs. Then, data from the manual calibration of the Ames MK40 six-component force balance is chosen to illustrate how estimates of the regression coefficients of the fitted balance loads can be obtained from the regression coefficients of the fitted strain-gage outputs. The study illustrates that load predictions obtained by applying the Iterative or the Non-Iterative Method originate from two related regression solutions of the balance calibration data as long as balance loads are given in the design format of the balance, gage outputs behave highly linear, strict statistical quality metrics are used to assess regression models of the data, and regression model term combinations of the fitted loads and gage outputs can be obtained by a simple variable exchange.

Work-life balance and welfare.

PubMed

Evans, Lois; Young, Greg

2017-04-01

An online survey and focus groups were conducted, providing qualitative information on the work-life balance of psychiatrists and trainees in Australasia. An invitation to participate in an anonymous online welfare survey was emailed to all the Royal Australian and New Zealand College of Psychiatrists trainees, Fellows, and Affiliates. Following this, nine focus groups were held across Australia and New Zealand. Responses received were thematically analysed. The emergent patterns are presented in this report. Our research suggests that work-life balance can be subjectively and objectively measured. There are phases of good and bad work-life balance, depending on stage of career and other commitments. Work-life balance may be an indicator of the health of individuals and organisations. Due to its complexity, with intrinsic and extrinsic factors involved, solutions are unlikely to be simple. Further studies are needed to substantiate our findings.

48 CFR 225.7703-5 - Solicitation provisions and contract clauses.

Code of Federal Regulations, 2011 CFR

2011-10-01

...—Balance of Payments Program Certificate. (5) 252.225-7036, Buy American Act—Free Trade Agreements—Balance...-7045, Balance of Payments Program—Construction Material Under Trade Agreements. (f) Do not use the... 252.225-7024, or the clause at 252.225-7026: (1) 252.225-7000, Buy American Act—Balance of Payments...

48 CFR 225.7703-5 - Solicitation provisions and contract clauses.

Code of Federal Regulations, 2010 CFR

2010-10-01

...—Balance of Payments Program Certificate. (5) 252.225-7036, Buy American Act—Free Trade Agreements—Balance...-7045, Balance of Payments Program—Construction Material Under Trade Agreements. (f) Do not use the... 252.225-7024, or the clause at 252.225-7026: (1) 252.225-7000, Buy American Act—Balance of Payments...

Influence of footwear midsole material hardness on dynamic balance control during unexpected gait termination.

PubMed

Perry, Stephen D; Radtke, Alison; Goodwin, Chris R

2007-01-01

The purpose of this study was to determine the influence of different midsole hardnesses on dynamic balance control during unexpected gait termination. Twelve healthy young female adults were asked to walk along an 8-m walkway, looking straight ahead. During 25% of the trials, they were signaled (via an audio buzzer) to terminate gait within the next two steps. The four experimental conditions were: (1) soft (A15); (2) standard (A33); (3) hard (A50); (4) barefoot. Center of mass (COM) position relative to the lateral base of support (BOS), center of mass-center of pressure (COM-COP) difference and vertical loading rate were used to evaluate the influence of midsole material on dynamic balance control. The results were a decrease in the medial-lateral range of COM with respect to the lateral BOS, a reduction in the maximum COM-COP difference and an increase in the vertical loading rate due to the presence and hardness level of the midsole material when compared to the barefoot condition. The primary outcomes of this study have illustrated the influence of midsole hardness as an impediment to dynamic balance control during responses to gait termination. In conclusion, the present study suggests that variations in midsole material and even the presence of it, impairs the dynamic balance control system.

Positivity-preserving well-balanced discontinuous Galerkin methods for the shallow water flows in open channels

NASA Astrophysics Data System (ADS)

Qian, Shouguo; Li, Gang; Shao, Fengjing; Xing, Yulong

2018-05-01

We construct and study efficient high order discontinuous Galerkin methods for the shallow water flows in open channels with irregular geometry and a non-flat bottom topography in this paper. The proposed methods are well-balanced for the still water steady state solution, and can preserve the non-negativity of wet cross section numerically. The well-balanced property is obtained via a novel source term separation and discretization. A simple positivity-preserving limiter is employed to provide efficient and robust simulations near the wetting and drying fronts. Numerical examples are performed to verify the well-balanced property, the non-negativity of the wet cross section, and good performance for both continuous and discontinuous solutions.

IRA balances and contributions: an overview of the EBRI IRA database.

PubMed

Copeland, Craig

2010-09-01

NEW IRA DATABASE: The Employee Benefit Research Institute created the EBRI IRA Database in order to more closely examine retirement savings behavior. The EBRI IRA Database is able to link individuals within and across the data providers and will also be able to link the data with participants in 401(k) plans, allowing retirement funds to be tracked as they are generated, rolled over, and ultimately used. This Issue Brief is the first of a series of publications analyzing the EBRI IRA Database, and highlights the distribution of IRA owners by IRA type, average and median account balances, and contributions to IRAs. The data security techniques used by the data providers assure that EBRI has no ability to identify individuals so that all privacy is assured. IRA TYPES: In the EBRI IRA Database, IRAs are classified into four types: traditional (originating from contributions), rollovers from other retirement plans, Roth, and SEP/SIMPLE. The distribution of the IRA accounts is 33.6 percent traditional IRAs; 33.4 percent rollover IRAs (combined with the traditional IRAs, 67 percent); 23.4 percent Roth IRAs; the remaining 9.6 percent are SEPs and SIMPLEs. OWNERSHIP BY AGE AND GENDER: IRA owners were more likely to be male, especially those having a rollover or a SEP/SIMPLE IRA. Among all IRA participants in the database, nearly one-half (48.3 percent) were ages 45-64. Only 16.7 percent of those owning a traditional IRA were under age 45, compared with 46.5 percent for those with a Roth, 30.4 percent for rollovers, and 34.8 percent for those with a SEP or SIMPLE. AVERAGE AND MEDIAN BALANCES: The average and median IRA account balance in 2008 was $54,863 and $15,756, respectively, while the average and median IRA individual balance (all accounts from the same person combined) was $69,498 and $20,046, Individuals with a rollover balance had the highest average and median balance at $91,783 and $31,264. Roth owners had the lowest average and median balance at $14,056 and $7,319. The average and median individual IRA balance increased with age before leveling off for those age 70 or older. Averages--The average amount contributed to an IRA in the database was $3,665 in 2008. The average contribution was highest for accounts owned by those ages 65-69. More contributions were made to Roth accounts than to traditional (combined traditional and rollover) accounts. However, the average contribution to a traditional account was higher, at $3,798, compared with $3,580 to a Roth account. Yet, a higher overall amount was contributed to Roth IRAs ($3.4 billion for Roths compared with $2.3 billion for traditional accounts). By type--Focusing only on those owning traditional, rollover, or Roth IRAs, 12.1 percent of the accounts were contributed to, and 15.1 percent of the individuals owning these IRA types contributed to them in 2008. When combining the owners of traditional and rollover IRAs (which are considered the same type for contribution purposes), 7.2 percent contributed, while 29.5 percent of those owning a Roth IRA contributed to a Roth IRA. Maxing out--Of those individuals contributing, 42.4 percent contributed the maximum amount. Of those contributing to a traditional or rollover IRA, 43.4 percent maxed out, while 40.2 percent did so with a Roth IRA.

Design Tools for Assessing Manufacturing Environmental Impact.

DTIC Science & Technology

1997-11-26

the material report alone. In order to more easily design, update and verify the output report, many of the cells which contained the information...needed for the material balance calculations were named. The cell name was then used in the calculations. Where possible the same names that were used in...Material balance information was used extensively to ensure all the equations were correct and were put into the appropriate cells . A summary of the

Modeling and Analysis of the Reverse Water Gas Shift Process for In-Situ Propellant Production

NASA Technical Reports Server (NTRS)

Whitlow, Jonathan E.

2000-01-01

This report focuses on the development of mathematical models and simulation tools developed for the Reverse Water Gas Shift (RWGS) process. This process is a candidate technology for oxygen production on Mars under the In-Situ Propellant Production (ISPP) project. An analysis of the RWGS process was performed using a material balance for the system. The material balance is very complex due to the downstream separations and subsequent recycle inherent with the process. A numerical simulation was developed for the RWGS process to provide a tool for analysis and optimization of experimental hardware, which will be constructed later this year at Kennedy Space Center (KSC). Attempts to solve the material balance for the system, which can be defined by 27 nonlinear equations, initially failed. A convergence scheme was developed which led to successful solution of the material balance, however the simplified equations used for the gas separation membrane were found insufficient. Additional more rigorous models were successfully developed and solved for the membrane separation. Sample results from these models are included in this report, with recommendations for experimental work needed for model validation.

Power Balance Analysis of the Prototype-Material Plasma Exposure eXperiment

NASA Astrophysics Data System (ADS)

Showers, M. A.; Biewer, T. M.; Caneses, J. F.; Caughman, J. B. O.; Lumsdaine, A.; Owen, L.; Rapp, J.; Youchison, D.; Beers, C. J.; Donovan, D. C.; Kafle, N.; Ray, H. B.

2017-10-01

The Prototype-Material Plasma Exposure eXperiment (Proto-MPEX) is a test bed for the plasma source concept for the planned Material Plasma Exposure eXperiment (MPEX), a steady-state linear device studying plasma material interactions for fusion reactors. A power balance of Proto-MPEX attempts to identify machine operating parameters that will improve Proto-MPEX's performance, potentially impacting the MPEX design concept. A power balance has been performed utilizing an extensive diagnostic suite to identify mechanisms and locations of power loss from the main plasma. The diagnostic package includes infrared cameras, double Langmuir probes, fluoroptic probes, Mach probes, a Thomson scattering diagnostic, a McPherson spectrometer and in-vessel thermocouples. Radiation losses are estimated with absolute calibrated spectroscopic signals. This work was supported by the U.S. D.O.E. contract DE-AC05-00OR22725.

48 CFR 225.7503 - Contract clauses.

Code of Federal Regulations, 2011 CFR

2011-10-01

... OF DEFENSE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Balance of Payments Program 225.7503 Contract clauses. Unless the entire acquisition is exempt from the Balance of Payments Program— (a)(1) Use the clause at 252.225-7044, Balance of Payments Program—Construction Material, in solicitations and contracts...

48 CFR 225.7503 - Contract clauses.

Code of Federal Regulations, 2010 CFR

2010-10-01

... OF DEFENSE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Balance of Payments Program 225.7503 Contract clauses. Unless the entire acquisition is exempt from the Balance of Payments Program— (a) Use the clause at 252.225-7044, Balance of Payments Program—Construction Material, in solicitations and contracts...

Design and Optimization of New Metallic Materials (Metal Foams) for the Reduction of the Noise of the Aeronautical Turbo Engines

DTIC Science & Technology

2005-02-01

AApproved for Public Release Distribution Unlimited SANS MENTION DE PROTECTION MATERIALS AND STRUCTURES -1- ONERA BP 72 - 29. avenue de la Division Leclerc...reduction. Finding the best solution in terns balancing structural strength and acoustic properties was the main thrust of this project. Acoustic...material system for noise reduction. Finding the best solution in terms balancing structural strength and acoustic properties was the main thrust of this

Control of mobility in molecular organic semiconductors by dendrimer generation

NASA Astrophysics Data System (ADS)

Lupton, J. M.; Samuel, I. D.; Beavington, R.; Frampton, M. J.; Burn, P. L.; Bässler, H.

2001-04-01

Conjugated dendrimers are of interest as novel materials for light-emitting diodes. They consist of a luminescent chromophore at the core with highly branched conjugated dendron sidegroups. In these materials, light emission occurs from the core and is independent of generation. The dendron branching controls the separation between the chromophores. We present here a family of conjugated dendrimers and investigate the effect of dendron branching on light emission and charge transport. We apply a number of transport measurement techniques to thin films of a conjugated dendrimer in a light-emitting diode configuration to determine the effect of chromophore spacing on charge transport. We find that the mobility is reduced by two orders of magnitude as the size of the molecule doubles with increased branching or dendrimer generation. The degree of branching allows a unique control of mobility by molecular structure. An increase in chromophore separation also results in a reduction of intermolecular interactions, which reduces the red emission tail in film photoluminescence. We find that the steady-state charge transport is well described by a simple device model incorporating the effect of generation, and use the materials to shed light on the interpretation of transient electroluminescence data. We demonstrate the significance of the ability to tune the mobility in bilayer devices, where a more balanced charge transport can be achieved.

Measurement of Momentum Transfer Coefficients for H2, N2, CO, and CO2 Incident Upon Spacecraft Surfaces

NASA Technical Reports Server (NTRS)

Cook, Steven R.; Hoffbauer, Mark A.

1997-01-01

Measurements of momentum transfer coefficients were made for gas-surface interactions between the Space Shuttle reaction control jet plume gases and the solar panel array materials to be used on the International Space Station. Actual conditions were simulated using a supersonic nozzle source to produce beams of the gases with approximately the same average velocities as the gases have in the Shuttle plumes. Samples of the actual solar panel materials were mounted on a torsion balance that was used to measure the force exerted on the surfaces by the molecular beams. Measurements were made with H2, N2, CO, and CO2 incident upon the solar array material, Kapton, SiO2-coated Kapton, and Z93-coated Al. The measurements showed that molecules scatter from the surfaces more specularly as the angle of incidence increases and that the scattering behavior has a strong dependence upon both the incident gas and velocity. These results show that for some technical surfaces the simple assumption of diffuse scattering with complete thermal accommodation is entirely inadequate. It is clear that additional measurements are required to produce models that more accurately describe the gas-surface interactions encountered in rarefied flow regimes.

High Textbook Reading Rates When Using an Interactive Textbook for a Material and Energy Balances Course

ERIC Educational Resources Information Center

Liberatore, Matthew

2017-01-01

Textbooks are experiencing a 21st century makeover. The author has created a web-based electronic textbook, Material and Energy Balances zyBook, that records students' interactions. Animations and question sets create interactive and scaffolded content. The interactive format is adopted successfully in other engineering disciplines and is now…

The Degrees of Freedom Concept--Extending the Domain

ERIC Educational Resources Information Center

Biernacki, J. J.

2016-01-01

The degrees of freedom (DOF) concept is a powerful tool that has been taught since at least the '70s in undergraduate curriculum, typically introduced in the context of a first course on material and energy balances. The concept, however, has not been widely applied beyond the material balance domain and in general is not taught as a unified…

Micarta Propellers II : Method of Construction

NASA Technical Reports Server (NTRS)

Caldwell, F W; Clay, N S

1924-01-01

The methods used in manufacturing Micarta propellers differ considerably from those employed with wood propellers on account of the hardness of the materials. The propellers must be formed accurately to size in a mold and afterwards balanced without the customary trimming of the material from the tips. Described here are the pressing and molding processes, filing, boring, balancing, and curing.

Ablative Laser Propulsion Using Multi-Layered Material Systems

NASA Technical Reports Server (NTRS)

Nehls, Mary; Edwards, David; Gray, Perry; Schneider, T.

2002-01-01

Experimental investigations are ongoing to study the force imparted to materials when subjected to laser ablation. When a laser pulse of sufficient energy density impacts a material, a small amount of the material is ablated. A torsion balance is used to measure the momentum produced by the ablation process. The balance consists of a thin metal wire with a rotating pendulum suspended in the middle. The wire is fixed at both ends. Recently, multi-layered material systems were investigated. These multi-layered materials were composed of a transparent front surface and opaque sub surface. The laser pulse penetrates the transparent outer surface with minimum photon loss and vaporizes the underlying opaque layer.

Comparison of residual stresses in Inconel 718 simple parts made by electron beam melting and direct laser metal sintering

DOE PAGES

Kolbus, Lindsay M.; Payzant, E. Andrew; Cornwell, Paris A.; ...

2015-01-10

Residual stress profiles were mapped using neutron diffraction in two simple prism builds of Inconel 718: one fabricated with electron beam melting and the other with direct laser sintering. Spatially indexed stress-free cubes were obtained by EDM sectioning equivalent prisms of similar shape. The (311) interplanar spacing examined for the EDM sectioned sample was compared to the interplanar spacings calculated to fulfill force and moment balance. We have shown that Applying force and moment balance is a necessary supplement to the measurements for the stress-free cubes with respect to accurate stress calculations in additively manufactured components. Furthermore, our work hasmore » shown that residual stresses in electron beam melting parts are much smaller than that of direct laser metal sintering parts.« less

Laser balancing system for high material removal rates

NASA Technical Reports Server (NTRS)

Jones, M. G.; Georgalas, G.; Ortiz, A. L.

1984-01-01

A laser technique to remove material in excess of 10 mg/sec from a spinning rotor is described. This material removal rate is 20 times greater than previously reported for a surface speed of 30 m/sec. Material removal enhancement was achieved by steering a focused laser beam with moving optics to increase the time of laser energy interaction with a particular location on the circumferential surface of a spinning rotor. A neodymium:yttrium aluminum garnet (Nd:YAG) pulse laser was used in this work to evaluate material removal for carbon steel, 347 stainless steel, Inconal 718, and titanium 6-4. This technique is applicable to dynamic laser balancing.

Basins of attraction in human balance

NASA Astrophysics Data System (ADS)

Smith, Victoria A.; Lockhart, Thurmon E.; Spano, Mark L.

2017-12-01

Falls are a recognized risk factor for unintentional injuries among older adults, accounting for a large proportion of fractures, emergency department visits, and urgent hospitalizations. Human balance and gait research traditionally uses linear or qualitative tests to assess and describe human motion; however, human motion is neither a simple nor a linear process. The objective of this research is to identify and to learn more about what factors affect balance using nonlinear dynamical techniques, such as basin boundaries. Human balance data was collected using dual force plates for leans using only ankle movements as well as for unrestricted leans. Algorithms to describe the basin boundary were created and compared based on how well each method encloses the experimental data points as well as captures the differences between the two leaning conditions.

Biodegradable and compostable alternatives to conventional plastics

PubMed Central

Song, J. H.; Murphy, R. J.; Narayan, R.; Davies, G. B. H.

2009-01-01

Packaging waste forms a significant part of municipal solid waste and has caused increasing environmental concerns, resulting in a strengthening of various regulations aimed at reducing the amounts generated. Among other materials, a wide range of oil-based polymers is currently used in packaging applications. These are virtually all non-biodegradable, and some are difficult to recycle or reuse due to being complex composites having varying levels of contamination. Recently, significant progress has been made in the development of biodegradable plastics, largely from renewable natural resources, to produce biodegradable materials with similar functionality to that of oil-based polymers. The expansion in these bio-based materials has several potential benefits for greenhouse gas balances and other environmental impacts over whole life cycles and in the use of renewable, rather than finite resources. It is intended that use of biodegradable materials will contribute to sustainability and reduction in the environmental impact associated with disposal of oil-based polymers. The diversity of biodegradable materials and their varying properties makes it difficult to make simple, generic assessments such as biodegradable products are all ‘good’ or petrochemical-based products are all ‘bad’. This paper discusses the potential impacts of biodegradable packaging materials and their waste management, particularly via composting. It presents the key issues that inform judgements of the benefits these materials have in relation to conventional, petrochemical-based counterparts. Specific examples are given from new research on biodegradability in simulated ‘home’ composting systems. It is the view of the authors that biodegradable packaging materials are most suitable for single-use disposable applications where the post-consumer waste can be locally composted. PMID:19528060

Perpendicular Orientation Control without Interfacial Treatment of RAFT-Synthesized High-χ Block Copolymer Thin Films with Sub-10 nm Features Prepared via Thermal Annealing.

PubMed

Nakatani, Ryuichi; Takano, Hiroki; Chandra, Alvin; Yoshimura, Yasunari; Wang, Lei; Suzuki, Yoshinori; Tanaka, Yuki; Maeda, Rina; Kihara, Naoko; Minegishi, Shinya; Miyagi, Ken; Kasahara, Yuusuke; Sato, Hironobu; Seino, Yuriko; Azuma, Tsukasa; Yokoyama, Hideaki; Ober, Christopher K; Hayakawa, Teruaki

2017-09-20

In this study, a series of perpendicular lamellae-forming poly(polyhedral oligomeric silsesquioxane methacrylate-block-2,2,2-trifluoroethyl methacrylate)s (PMAPOSS-b-PTFEMAs) was developed based on the bottom-up concept of creating a simple yet effective material by tailoring the chemical properties and molecular composition of the material. The use of silicon (Si)-containing hybrid high-χ block copolymers (BCPs) provides easy access to sub-10 nm feature sizes. However, as the surface free energies (SFEs) of Si-containing polymers are typically vastly lower than organic polymers, this tends to result in the selective segregation of the inorganic block onto the air interface and increased difficulty in controlling the BCP orientation in thin films. Therefore, by balancing the SFEs between the organic and inorganic blocks through the use of poly(2,2,2-trifluoroethyl methacrylate) (PTFEMA) on the organic block, a polymer with an SFE similar to Si-containing polymers, orientation control of the BCP domains in thin films becomes much simpler. Herein, perpendicularly oriented BCP thin films with a χ eff value of 0.45 were fabricated using simple spin-coating and thermal annealing processes under ambient conditions. The thin films displayed a minimum domain size of L 0 = 11 nm, as observed via atomic force microscopy (AFM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Furthermore, directed self-assembly (DSA) of the BCP on a topographically prepatterned substrate using the grapho-epitaxy method was used to successfully obtain perpendicularly oriented lamellae with a half pitch size of ca. 8 nm.

Dual-Latching, Solenoid-Actuated Tube Valve

NASA Technical Reports Server (NTRS)

Brudnicki, Myron J.

1993-01-01

Tube-type shutoff valve electrically positioned to open or closed state by concentric solenoid. Solenoid dual latching: it holds position until changed electrically or manually. In tube valve, central tube slides axially, closing off flow when held against seat and allowing flow when backed away from seat. Simple to balance pressure on seal between seat and sharp edge of tube. With pressure-balanced seal, only small force needed to hold valve in position, regardless of pressure acting on valve.

A Simple, Low-cost, and Robust System to Measure the Volume of Hydrogen Evolved by Chemical Reactions with Aqueous Solutions

PubMed Central

Brack, Paul; Dann, Sandie; Wijayantha, K. G. Upul; Adcock, Paul; Foster, Simon

2016-01-01

There is a growing research interest in the development of portable systems which can deliver hydrogen on-demand to proton exchange membrane (PEM) hydrogen fuel cells. Researchers seeking to develop such systems require a method of measuring the generated hydrogen. Herein, we describe a simple, low-cost, and robust method to measure the hydrogen generated from the reaction of solids with aqueous solutions. The reactions are conducted in a conventional one-necked round-bottomed flask placed in a temperature controlled water bath. The hydrogen generated from the reaction in the flask is channeled through tubing into a water-filled inverted measuring cylinder. The water displaced from the measuring cylinder by the incoming gas is diverted into a beaker on a balance. The balance is connected to a computer, and the change in the mass reading of the balance over time is recorded using data collection and spreadsheet software programs. The data can then be approximately corrected for water vapor using the method described herein, and parameters such as the total hydrogen yield, the hydrogen generation rate, and the induction period can also be deduced. The size of the measuring cylinder and the resolution of the balance can be changed to adapt the setup to different hydrogen volumes and flow rates. PMID:27584581

Totally confined explosive welding

NASA Technical Reports Server (NTRS)

Bement, L. J. (Inventor)

1978-01-01

The undesirable by-products of explosive welding are confined and the association noise is reduced by the use of a simple enclosure into which the explosive is placed and in which the explosion occurs. An infrangible enclosure is removably attached to one of the members to be bonded at the point directly opposite the bond area. An explosive is completely confined within the enclosure at a point in close proximity to the member to be bonded and a detonating means is attached to the explosive. The balance of the enclosure, not occupied by explosive, is filled with a shaped material which directs the explosive pressure toward the bond area. A detonator adaptor controls the expansion of the enclosure by the explosive force so that the enclosure at no point experiences a discontinuity in expansion which causes rupture. The use of the technique is practical in the restricted area of a space station.

Venous Ulcers

PubMed Central

Caprini, J.A.; Partsch, H.; Simman, R.

2013-01-01

Venous leg ulcers are the most frequent form of wounds seen in patients. This article presents an overview on some practical aspects concerning diagnosis, differential diagnosis and treatment. Duplex ultrasound investigations are essential to ascertain the diagnosis of the underlying venous pathology and to treat venous refluxes. Differential diagnosis includes mainly other vascular lesions (arterial, microcirculatory causes), hematologic and metabolic diseases, trauma, infection, malignancies. Patients with superficial venous incompetence may benefit from endovenous or surgical reflux abolition diagnosed by Duplex ultrasound. The most important basic component of the management is compression therapy, for which we prefer materials with low elasticity applied with high initial pressure (short-stretch bandages and Velcro-strap devices). Local treatment should be simple, absorbing and not sticky dressings keeping adequate moisture balance after debridement of necrotic tissue and biofilms are preferred. After the ulcer is healed compression therapy should be continued in order to prevent recurrence. PMID:26236636

Digital rights language support for evolving digital cinema requirements

NASA Astrophysics Data System (ADS)

Orri, Xavier; Mas, Joan-Maria; Macq, Benoit M. M.

2003-06-01

Digital cinema can be defined as the digital electronic distribution and display of theatrical film content or live material to the theatre. However, this simple definition does not reflect the complex mesh of balanced business relationships between the different parties involved in the worldwide cinematic distribution. Its transition from an analogue to a digital business will happen progressively, starting with only content being digitally distributed and going until an all-digital business. From these facts derive strong requirements on digital rights management (DRM) systems for digital cinema and therefore on the digital rights language supporting it. This paper explores the requirements imposed by the cinematic distribution model and by its progressive transition to digital, and the impact these have on digital rights languages. We analyze the support provided by different digital rights languages, identifying weaknesses and exploring solutions in fulfilling the requirements of the digital cinema distribution model.

Nanostructural characterization of amorphous diamondlike carbon films

DOE Office of Scientific and Technical Information (OSTI.GOV)

SIEGAL,MICHAEL P.; TALLANT,DAVID R.; MARTINEZ-MIRANDA,L.J.

2000-01-27

Nanostructural characterization of amorphous diamondlike carbon (a-C) films grown on silicon using pulsed-laser deposition (PLD) is correlated to both growth energetic and film thickness. Raman spectroscopy and x-ray reflectivity probe both the topological nature of 3- and 4-fold coordinated carbon atom bonding and the topographical clustering of their distributions within a given film. In general, increasing the energetic of PLD growth results in films becoming more ``diamondlike'', i.e. increasing mass density and decreasing optical absorbance. However, these same properties decrease appreciably with thickness. The topology of carbon atom bonding is different for material near the substrate interface compared to materialmore » within the bulk portion of an a-C film. A simple model balancing the energy of residual stress and the free energies of resulting carbon topologies is proposed to provide an explanation of the evolution of topographical bonding clusters in a growing a-C film.« less

Improved Student Achievement Using Personalized Online Homework for a Course in Material and Energy Balances

ERIC Educational Resources Information Center

Liberatore, Matthew W.

2011-01-01

Personalized, online homework was used to supplement textbook homework, quizzes, and exams for one section of a course in material and energy balances. The objective of this study was to test the hypothesis that students using personalized, online homework earned better grades in the course. The online homework system asks the same questions of…

Mobility Lab to Assess Balance and Gait with Synchronized Body-worn Sensors

PubMed Central

Mancini, Martina; King, Laurie; Salarian, Arash; Holmstrom, Lars; McNames, James; Horak, Fay B

2014-01-01

This paper is a commentary to introduce how rehabilitation professionals can use a new, body-worn sensor system to obtain objective measures of balance and gait. Current assessments of balance and gait in clinical rehabilitation are largely limited to subjective scales, simple stop-watch measures, or complex, expensive machines not practical or largely available. Although accelerometers and gyroscopes have been shown to accurately quantify many aspects of gait and balance kinematics, only recently a comprehensive, portable system has become available for clinicians. By measuring body motion during tests that clinicians are already performing, such as the Timed Up and Go test (TUG) and the Clinical Test of Sensory Integration for Balance (CITSIB), the additional time for assessment is minimal. By providing instant analysis of balance and gait and comparing a patient’s performance to age-matched control values, therapists receive an objective, sensitive screening profile of balance and gait strategies. This motion screening profile can be used to identify mild abnormalities not obvious with traditional clinical testing, measure small changes due to rehabilitation, and design customized rehabilitation programs for each individual’s specific balance and gait deficits. PMID:24955286

75 FR 32635 - Defense Acquisition Regulations System; Defense Federal Acquisition Regulation Supplement...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-08

... Regulations System; Defense Federal Acquisition Regulation Supplement; Balance of Payments Program Exemption... implement the exemption from the Balance of Payments Program for construction material that is commercial... is proposing to amend the DFARS to implement in the clauses at 252.225-7044, Balance of Payments...

Efficient hybrid white organic light-emitting diodes for application of triplet harvesting with simple structure

NASA Astrophysics Data System (ADS)

Hwang, Kyo Min; Lee, Song Eun; Lee, Sungkyu; Yoo, Han Kyu; Baek, Hyun Jung; Kim, Young Kwan; Kim, Jwajin; Yoon, Seung Soo

2016-08-01

In this study, we fabricated hybrid white organic light-emitting diodes (WOLEDs) based on triplet harvesting with a simple structure. All the hole transporting material and host in the emitting layer (EML) of devices utilized the same material N,N'-di-1-naphthalenyl-N,N'-diphenyl [1,1':4',1″:4″,1‴-quaterphenyl]-4,4‴-diamine (4P-NPD), which is known to be blue fluorescent material. Simple hybrid WOLEDs were fabricated with blue fluorescent, green and red phosphorescent materials. We investigated the effect of triplet harvesting (TH) by an exciton generation zone on simple hybrid WOLEDs. The simple hybrid WOLEDs characteristically had a dominant hole mobility, so an exciton generation zone was expected in the EML. Additionally, the optimal the thickness of the hole transporting layer and electron transporting layer was fabricated a simple hybrid WOLEDs. The simple hybrid WOLED exhibits a maximum luminous efficiency of 29.3 cd/A and a maximum external quantum efficiency of 11.2%. The Commission Internationale de l'Éclairage (International Commission on Illumination) coordinates were (0.45, 0.43) at about 10,000 cd/m2.

Schrödinger and Dirac solutions to few-body problems

NASA Astrophysics Data System (ADS)

Muolo, Andrea; Reiher, Markus

We elaborate on the variational solution of the Schrödinger and Dirac equations for small atomic and molecular systems without relying on the Born-Oppenheimer approximation. The all-particle equations of motion are solved in a numerical procedure that relies on the variational principle, Cartesian coordinates and parametrized explicitly correlated Gaussians functions. A stochastic optimization of the variational parameters allows the calculation of accurate wave functions for ground and excited states. Expectation values such as the radial and angular distribution functions or the dipole moment can be calculated. We developed a simple strategy for the elimination of the global translation that allows to generally adopt laboratory-fixed cartesian coordinates. Simple expressions for the coordinates and operators are then preserved throughout the formalism. For relativistic calculations we devised a kinetic-balance condition for explicitly correlated basis functions. We demonstrate that the kinetic-balance condition can be obtained from the row reduction process commonly applied to solve systems of linear equations. The resulting form of kinetic balance establishes a relation between all components of the spinor of an N-fermion system. ETH Zürich, Laboratorium für Physikalische Chemie, CH-8093 Zürich, Switzerland.

Complexity Survey.

ERIC Educational Resources Information Center

Gordon, Sandra L.; Anderson, Beth C.

To determine whether consensus existed among teachers about the complexity of common classroom materials, a survey was administered to 66 pre-service and in-service kindergarten and prekindergarten teachers. Participants were asked to rate 14 common classroom materials as simple, complex, or super-complex. Simple materials have one obvious part,…

A novel multiple batch extraction test to assess contaminant mobilization from porous waste materials

NASA Astrophysics Data System (ADS)

Iden, S. C.; Durner, W.; Delay, M.; Frimmel, F. H.

2009-04-01

Contaminated porous materials, like soils, dredged sediments or waste materials must be tested before they can be used as filling materials in order to minimize the risk of groundwater pollution. We applied a multiple batch extraction test at varying liquid-to-solid (L/S) ratios to a demolition waste material and a municipal waste incineration product and investigated the release of chloride, sulphate, sodium, copper, chromium and dissolved organic carbon from both waste materials. The liquid phase test concentrations were used to estimate parameters of a relatively simple mass balance model accounting for equilibrium partitioning. The model parameters were estimated within a Bayesian framework by applying an efficient MCMC sampler and the uncertainties of the model parameters and model predictions were quantified. We tested isotherms of the linear, Freundlich and Langmuir type and selected the optimal isotherm model by use of the Deviance Information Criterion (DIC). Both the excellent fit to the experimental data and a comparison between the model-predicted and independently measured concentrations at the L/S ratios of 0.25 and 0.5 L/kg demonstrate the applicability of the model for almost all studied substances and both waste materials. We conclude that batch extraction tests at varying L/S ratios provide, at moderate experimental cost, a powerful complement to established test designs like column leaching or single batch extraction tests. The method constitutes an important tool in risk assessments, because concentrations at soil water contents representative for the field situation can be predicted from easier-to-obtain test concentrations at larger L/S ratios. This helps to circumvent the experimental difficulties of the soil saturation extract and eliminates the need to apply statistical approaches to predict such representative concentrations which have been shown to suffer dramatically from poor correlations.

Uncertainty analysis on simple mass balance model to calculate critical loads for soil acidity.

PubMed

Li, Harbin; McNulty, Steven G

2007-10-01

Simple mass balance equations (SMBE) of critical acid loads (CAL) in forest soil were developed to assess potential risks of air pollutants to ecosystems. However, to apply SMBE reliably at large scales, SMBE must be tested for adequacy and uncertainty. Our goal was to provide a detailed analysis of uncertainty in SMBE so that sound strategies for scaling up CAL estimates to the national scale could be developed. Specifically, we wanted to quantify CAL uncertainty under natural variability in 17 model parameters, and determine their relative contributions in predicting CAL. Results indicated that uncertainty in CAL came primarily from components of base cation weathering (BC(w); 49%) and acid neutralizing capacity (46%), whereas the most critical parameters were BC(w) base rate (62%), soil depth (20%), and soil temperature (11%). Thus, improvements in estimates of these factors are crucial to reducing uncertainty and successfully scaling up SMBE for national assessments of CAL.

The Hydrological Sensitivity to Global Warming and Solar Geoengineering Derived from Thermodynamic Constraints

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kleidon, Alex; Kravitz, Benjamin S.; Renner, Maik

2015-01-16

We derive analytic expressions of the transient response of the hydrological cycle to surface warming from an extremely simple energy balance model in which turbulent heat fluxes are constrained by the thermodynamic limit of maximum power. For a given magnitude of steady-state temperature change, this approach predicts the transient response as well as the steady-state change in surface energy partitioning and the hydrologic cycle. We show that the transient behavior of the simple model as well as the steady state hydrological sensitivities to greenhouse warming and solar geoengineering are comparable to results from simulations using highly complex models. Many ofmore » the global-scale hydrological cycle changes can be understood from a surface energy balance perspective, and our thermodynamically-constrained approach provides a physically robust way of estimating global hydrological changes in response to altered radiative forcing.« less

Computing multiple periodic solutions of nonlinear vibration problems using the harmonic balance method and Groebner bases

NASA Astrophysics Data System (ADS)

Grolet, Aurelien; Thouverez, Fabrice

2015-02-01

This paper is devoted to the study of vibration of mechanical systems with geometric nonlinearities. The harmonic balance method is used to derive systems of polynomial equations whose solutions give the frequency component of the possible steady states. Groebner basis methods are used for computing all solutions of polynomial systems. This approach allows to reduce the complete system to an unique polynomial equation in one variable driving all solutions of the problem. In addition, in order to decrease the number of variables, we propose to first work on the undamped system, and recover solution of the damped system using a continuation on the damping parameter. The search for multiple solutions is illustrated on a simple system, where the influence of the retained number of harmonic is studied. Finally, the procedure is applied on a simple cyclic system and we give a representation of the multiple states versus frequency.

A Simple Encryption Algorithm for Quantum Color Image

NASA Astrophysics Data System (ADS)

Li, Panchi; Zhao, Ya

2017-06-01

In this paper, a simple encryption scheme for quantum color image is proposed. Firstly, a color image is transformed into a quantum superposition state by employing NEQR (novel enhanced quantum representation), where the R,G,B values of every pixel in a 24-bit RGB true color image are represented by 24 single-qubit basic states, and each value has 8 qubits. Then, these 24 qubits are respectively transformed from a basic state into a balanced superposition state by employed the controlled rotation gates. At this time, the gray-scale values of R, G, B of every pixel are in a balanced superposition of 224 multi-qubits basic states. After measuring, the whole image is an uniform white noise, which does not provide any information. Decryption is the reverse process of encryption. The experimental results on the classical computer show that the proposed encryption scheme has better security.

Active Learning and Just-in-Time Teaching in a Material and Energy Balances Course

ERIC Educational Resources Information Center

Liberatore, Matthew W.

2013-01-01

The delivery of a material and energy balances course is enhanced through a series of in-class and out-of-class exercises. An active learning classroom is achieved, even at class sizes over 150 students, using multiple instructors in a single classroom, problem solving in teams, problems based on YouTube videos, and just-in-time teaching. To avoid…

A novel approach to sports concussion assessment: Computerized multilimb reaction times and balance control testing.

PubMed

Vartiainen, Matti V; Holm, Anu; Lukander, Jani; Lukander, Kristian; Koskinen, Sanna; Bornstein, Robert; Hokkanen, Laura

2016-01-01

Mild traumatic brain injuries (MTBI) or concussions often result in problems with attention, executive functions, and motor control. For better identification of these diverse problems, novel approaches integrating tests of cognitive and motor functioning are needed. The aim was to characterize minor changes in motor and cognitive performance after sports-related concussions with a novel test battery, including balance tests and a computerized multilimb reaction time test. The cognitive demands of the battery gradually increase from a simple stimulus response to a complex task requiring executive attention. A total of 113 male ice hockey players (mean age = 24.6 years, SD = 5.7) were assessed before a season. During the season, nine concussed players were retested within 36 hours, four to six days after the concussion, and after the season. A control group of seven nonconcussed players from the same pool of players with comparable demographics were retested after the season. Performance was measured using a balance test and the Motor Cognitive Test battery (MotCoTe) with multilimb responses in simple reaction, choice reaction, inhibition, and conflict resolution conditions. The performance of the concussed group declined at the postconcussion assessment compared to both the baseline measurement and the nonconcussed controls. Significant changes were observed in the concussed group for the multilimb choice reaction and inhibition tests. Tapping and balance showed a similar trend, but no statistically significant difference in performance. In sports-related concussions, complex motor tests can be valuable additions in assessing the outcome and recovery. In the current study, using subtasks with varying cognitive demands, it was shown that while simple motor performance was largely unaffected, the more complex tasks induced impaired reaction times for the concussed subjects. The increased reaction times may reflect the disruption of complex and integrative cognitive function in concussions.

Data Partitioning and Load Balancing in Parallel Disk Systems

NASA Technical Reports Server (NTRS)

Scheuermann, Peter; Weikum, Gerhard; Zabback, Peter

1997-01-01

Parallel disk systems provide opportunities for exploiting I/O parallelism in two possible waves, namely via inter-request and intra-request parallelism. In this paper we discuss the main issues in performance tuning of such systems, namely striping and load balancing, and show their relationship to response time and throughput. We outline the main components of an intelligent, self-reliant file system that aims to optimize striping by taking into account the requirements of the applications and performs load balancing by judicious file allocation and dynamic redistributions of the data when access patterns change. Our system uses simple but effective heuristics that incur only little overhead. We present performance experiments based on synthetic workloads and real-life traces.

Reactions of Standing Bipeds on Moving Platforms to Keep Their Balance May Increase the Amplitude of Oscillations of Platforms Satisfying Hooke’s Law

PubMed Central

Goldsztein, Guillermo H.

2016-01-01

Consider a person standing on a platform that oscillates laterally, i.e. to the right and left of the person. Assume the platform satisfies Hooke’s law. As the platform moves, the person reacts and moves its body attempting to keep its balance. We develop a simple model to study this phenomenon and show that the person, while attempting to keep its balance, may do positive work on the platform and increase the amplitude of its oscillations. The studies in this article are motivated by the oscillations in pedestrian bridges that are sometimes observed when large crowds cross them. PMID:27304857

Reactions of Standing Bipeds on Moving Platforms to Keep Their Balance May Increase the Amplitude of Oscillations of Platforms Satisfying Hooke's Law.

PubMed

Goldsztein, Guillermo H

2016-01-01

Consider a person standing on a platform that oscillates laterally, i.e. to the right and left of the person. Assume the platform satisfies Hooke's law. As the platform moves, the person reacts and moves its body attempting to keep its balance. We develop a simple model to study this phenomenon and show that the person, while attempting to keep its balance, may do positive work on the platform and increase the amplitude of its oscillations. The studies in this article are motivated by the oscillations in pedestrian bridges that are sometimes observed when large crowds cross them.

Synergetic Influences of Mixed-Host Emitting Layer Structures and Hole Injection Layers on Efficiency and Lifetime of Simplified Phosphorescent Organic Light-Emitting Diodes.

PubMed

Han, Tae-Hee; Kim, Young-Hoon; Kim, Myung Hwan; Song, Wonjun; Lee, Tae-Woo

2016-03-09

We used various nondestructive analyses to investigate various host material systems in the emitting layer (EML) of simple-structured, green phosphorescent organic light-emitting diodes (OLEDs) to clarify how the host systems affect its luminous efficiency (LE) and operational stability. An OLED that has a unipolar single-host EML with conventional poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) ( PSS) showed high operating voltage, low LE (∼26.6 cd/A, 13.7 lm/W), and short lifetime (∼4.4 h @ 1000 cd/m(2)). However, the combined use of a gradient mixed-host EML and a molecularly controlled HIL that has increased surface work function (WF) remarkably decreased operating voltage and improved LE (∼68.7 cd/A, 77.0 lm/W) and lifetime (∼70.7 h @ 1000 cd/m(2)). Accumulated charges at the injecting interfaces and formation of a narrow recombination zone close to the interfaces are the major factors that accelerate degradation of charge injection/transport and electroluminescent properties of OLEDs, so achievement of simple-structured OLEDs with high efficiency and long lifetime requires facilitating charge injection and balanced transport into the EML and distributing charge carriers and excitons in EML.

Welding arc plasma physics

NASA Technical Reports Server (NTRS)

Cain, Bruce L.

1990-01-01

The problems of weld quality control and weld process dependability continue to be relevant issues in modern metal welding technology. These become especially important for NASA missions which may require the assembly or repair of larger orbiting platforms using automatic welding techniques. To extend present welding technologies for such applications, NASA/MSFC's Materials and Processes Lab is developing physical models of the arc welding process with the goal of providing both a basis for improved design of weld control systems, and a better understanding of how arc welding variables influence final weld properties. The physics of the plasma arc discharge is reasonably well established in terms of transport processes occurring in the arc column itself, although recourse to sophisticated numerical treatments is normally required to obtain quantitative results. Unfortunately the rigor of these numerical computations often obscures the physics of the underlying model due to its inherent complexity. In contrast, this work has focused on a relatively simple physical model of the arc discharge to describe the gross features observed in welding arcs. Emphasis was placed of deriving analytic expressions for the voltage along the arc axis as a function of known or measurable arc parameters. The model retains the essential physics for a straight polarity, diffusion dominated free burning arc in argon, with major simplifications of collisionless sheaths and simple energy balances at the electrodes.

Germany's Persistent Balance-of-Payments Disequilibrium Revisited. German Studies Notes.

ERIC Educational Resources Information Center

Kindleberger, Charles P.

This essay compares Germany's persistent financial disequilibrium with the balance of payments situation in the United States. Delivered at a Symposium on German Economic Growth and Stability, the author concentrates on Germany's balance of payments surplus and presents U.S. figures mainly as a point of comparison. The material on Germany has been…

Heat flux estimates of power balance on Proto-MPEX with IR imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Showers, M., E-mail: mshower1@vols.utk.edu; Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831; Biewer, T. M.

The Prototype Material Plasma Exposure eXperiment (Proto-MPEX) at Oak Ridge National Laboratory (ORNL) is a precursor linear plasma device to the Material Plasma Exposure eXperiment (MPEX), which will study plasma material interactions (PMIs) for future fusion reactors. This paper will discuss the initial steps performed towards completing a power balance on Proto-MPEX to quantify where energy is lost from the plasma, including the relevant diagnostic package implemented. Machine operating parameters that will improve Proto-MPEX’s performance may be identified, increasing its PMI research capabilities.

Quartz Crystal Microbalance Operation and In Situ Calibration

NASA Technical Reports Server (NTRS)

Albyn, K. C.

2004-01-01

Quartz crystal microbalances (QCMs) are commonly used to measure the rate of deposition of molecular species on a surface. The measurement is often used to select materials with a low outgassing rate for applications where the material has a line of sight to a contamination-sensitive surface. A quantitative, in situ calibration of the balance, or balances, using a pure material for which the enthalpy of sublimation is known, is described in this Technical Memorandum. Supporting calculations for surface dwell times of deposited materials and the effusion cell Clausing factor are presented along with examples of multiple QCM measurements of outgassing from a common source.

Understanding and comparisons of different sampling approaches for the Fourier Amplitudes Sensitivity Test (FAST)

PubMed Central

Xu, Chonggang; Gertner, George

2013-01-01

Fourier Amplitude Sensitivity Test (FAST) is one of the most popular uncertainty and sensitivity analysis techniques. It uses a periodic sampling approach and a Fourier transformation to decompose the variance of a model output into partial variances contributed by different model parameters. Until now, the FAST analysis is mainly confined to the estimation of partial variances contributed by the main effects of model parameters, but does not allow for those contributed by specific interactions among parameters. In this paper, we theoretically show that FAST analysis can be used to estimate partial variances contributed by both main effects and interaction effects of model parameters using different sampling approaches (i.e., traditional search-curve based sampling, simple random sampling and random balance design sampling). We also analytically calculate the potential errors and biases in the estimation of partial variances. Hypothesis tests are constructed to reduce the effect of sampling errors on the estimation of partial variances. Our results show that compared to simple random sampling and random balance design sampling, sensitivity indices (ratios of partial variances to variance of a specific model output) estimated by search-curve based sampling generally have higher precision but larger underestimations. Compared to simple random sampling, random balance design sampling generally provides higher estimation precision for partial variances contributed by the main effects of parameters. The theoretical derivation of partial variances contributed by higher-order interactions and the calculation of their corresponding estimation errors in different sampling schemes can help us better understand the FAST method and provide a fundamental basis for FAST applications and further improvements. PMID:24143037

Understanding and comparisons of different sampling approaches for the Fourier Amplitudes Sensitivity Test (FAST).

PubMed

Xu, Chonggang; Gertner, George

2011-01-01

Fourier Amplitude Sensitivity Test (FAST) is one of the most popular uncertainty and sensitivity analysis techniques. It uses a periodic sampling approach and a Fourier transformation to decompose the variance of a model output into partial variances contributed by different model parameters. Until now, the FAST analysis is mainly confined to the estimation of partial variances contributed by the main effects of model parameters, but does not allow for those contributed by specific interactions among parameters. In this paper, we theoretically show that FAST analysis can be used to estimate partial variances contributed by both main effects and interaction effects of model parameters using different sampling approaches (i.e., traditional search-curve based sampling, simple random sampling and random balance design sampling). We also analytically calculate the potential errors and biases in the estimation of partial variances. Hypothesis tests are constructed to reduce the effect of sampling errors on the estimation of partial variances. Our results show that compared to simple random sampling and random balance design sampling, sensitivity indices (ratios of partial variances to variance of a specific model output) estimated by search-curve based sampling generally have higher precision but larger underestimations. Compared to simple random sampling, random balance design sampling generally provides higher estimation precision for partial variances contributed by the main effects of parameters. The theoretical derivation of partial variances contributed by higher-order interactions and the calculation of their corresponding estimation errors in different sampling schemes can help us better understand the FAST method and provide a fundamental basis for FAST applications and further improvements.

Cleaning by Surfactant Gradients: Particulate Removal from Porous Materials and the Significance of Rinsing in Laundry Detergency

NASA Astrophysics Data System (ADS)

Shin, Sangwoo; Warren, Patrick B.; Stone, Howard A.

2018-03-01

Removing particles from fibrous materials involves loosening via surfactants followed by particle transfer in a flow. While flow advection is commonly believed to be the major driver for pore-scale transport, small pores within the fabric do not allow any significant fluid flow inside them, thus significantly reducing the role of advection. However, rinsing the fabric with fresh water naturally establishes a surfactant gradient within the pore space, providing a suitable environment for particles to undergo diffusiophoresis. We demonstrate that this mechanism can remove particles from deep within fabric pores at an accelerated rate. The nonlinear aspect of diffusiophoresis significantly prolongs the lifetime of the phoretic motion beyond the naive solute diffusion time scale during rinsing, allowing long-lasting, continuous removal of particles. Moreover, owing to the fine balance between chemiphoresis and electrophoresis for particles in anionic surfactant concentration gradients, we show that the particle removal is sensitive to the counterion mobility, suggesting a simple route to control the effect. We thus claim to have resolved the "stagnant core problem"—a long-standing mystery in laundry detergency—and have identified a physicochemical approach to particle transport in fibrous media with broad applicability.

Parametric amplification and bidirectional invisibility in PT -symmetric time-Floquet systems

NASA Astrophysics Data System (ADS)

Koutserimpas, Theodoros T.; Alù, Andrea; Fleury, Romain

2018-01-01

Parity-time (PT )-symmetric wave devices, which exploit balanced interactions between material gain and loss, exhibit extraordinary properties, including lasing and flux-conserving scattering processes. In a seemingly different research field, periodically driven systems, also known as time-Floquet systems, have been widely studied as a relevant platform for reconfigurable active wave control and manipulation. In this article, we explore the connection between PT -symmetry and parametric time-Floquet systems. Instead of relying on material gain, we use parametric amplification by considering a time-periodic modulation of the refractive index at a frequency equal to twice the incident signal frequency. We show that the scattering from a simple parametric slab, whose dynamics follows the Mathieu equation, can be described by a PT -symmetric scattering matrix, whose PT -breaking threshold corresponds to the Mathieu instability threshold. By combining different parametric slabs modulated out of phase, we create PT -symmetric time-Floquet systems that feature exceptional scattering properties, such as coherent perfect absorption (CPA)-laser operation and bidirectional invisibility. These bidirectional properties, rare for regular PT -symmetric systems, are related to a compensation of parametric amplification due to multiple scattering between two parametric systems modulated with a phase difference.

On the Misuse of the Laplace Law in Bio Fluid Dynamics

NASA Astrophysics Data System (ADS)

Thatte, Azam

2005-11-01

The Laplace law is commonly applied in biomechanical analyses of blood vessels, lung alveoli, and the gastrointestinal tract, often without concern to assumptions that underlie its use. This ``law'' is a simple force balance applied across the wall of a static pressurized (δP) vessel for small thickness-to-radius ratio τ/r. However, the true thin-wall requirement is more severe than τ/r << 1. Furthermore, because the Laplace law estimates total stress rather than deviatoric stress, the common practice of evaluating material stiffness by plotting Laplace law stress against strain is, in principle, incorrect. To study the validity of the Laplace law in biomechanical applications, we solved exactly the model problem of an axisymmetric pressurized cylinder of arbitrary thickness, linearly elastic isotropic material, in steady state, with the no-load state (δP = 0) as the zero stress state. Vessel radii and all stresses (total, deviatoric, hydrostatic) are predicted as functions of δP. We find that the Laplace law is invalid for many biomechanical applications and that total stress is not an appropriate surrogate for deviatoric stress to evaluate stiffness. We propose a model for deviatoric stress that we argue should replace the Laplace law for many biomechanical applications.

Material Development and Meeting Learner's Need

ERIC Educational Resources Information Center

Aydin, Abdullah

2013-01-01

In this study, the aim was to show that learners' needs can be met using simple and cheap materials that can be found everywhere in 9th to 11th grade Chemistry courses. To this end, materials were developed using simple everyday life materials for 9th to 11th grade Chemistry courses. In the research, the project method was employed. The study was…

Using thermal balance model to determine optimal reactor volume and insulation material needed in a laboratory-scale composting reactor.

PubMed

Wang, Yongjiang; Pang, Li; Liu, Xinyu; Wang, Yuansheng; Zhou, Kexun; Luo, Fei

2016-04-01

A comprehensive model of thermal balance and degradation kinetics was developed to determine the optimal reactor volume and insulation material. Biological heat production and five channels of heat loss were considered in the thermal balance model for a representative reactor. Degradation kinetics was developed to make the model applicable to different types of substrates. Simulation of the model showed that the internal energy accumulation of compost was the significant heat loss channel, following by heat loss through reactor wall, and latent heat of water evaporation. Lower proportion of heat loss occurred through the reactor wall when the reactor volume was larger. Insulating materials with low densities and low conductive coefficients were more desirable for building small reactor systems. Model developed could be used to determine the optimal reactor volume and insulation material needed before the fabrication of a lab-scale composting system. Copyright © 2016 Elsevier Ltd. All rights reserved.

In vitro biocompatibility and electrical stability of thick-film platinum/gold alloy electrodes printed on alumina

NASA Astrophysics Data System (ADS)

Carnicer-Lombarte, Alejandro; Lancashire, Henry T.; Vanhoestenberghe, Anne

2017-06-01

Objective. High-density electrode arrays are a powerful tool in both clinical neuroscience and basic research. However, current manufacturing techniques require the use of specialised techniques and equipment, which are available to few labs. We have developed a high-density electrode array with customisable design, manufactured using simple printing techniques and with commercially available materials. Approach. Electrode arrays were manufactured by thick-film printing a platinum-gold alloy (Pt/Au) and an insulating dielectric on 96% alumina ceramic plates. Arrays were conditioned in serum and serum-free conditions, with and without 1 kHz, 200 µA, charge balanced stimulation for up to 21 d. Array biocompatibility was assessed using an extract assay and a PC-12 cell contact assay. Electrode impedance, charge storage capacity and charge injection capacity were before and after array conditioning. Main results. The manufactured Pt/Au electrodes have a highly porous surface and exhibit electrical properties comparable to arrays manufactured using alternative techniques. Materials used in array manufacture were found to be non-toxic to L929 fibroblasts by extract assay, and neuronal-like PC-12 cells adhered and extended neurites on the array surfaces. Arrays remained functional after long-term delivery of electrical pulses while exposed to protein-rich environments. Charge storage capacities and charge injection capacities increased following stimulation accounted for by an increase in surface index (real surface area) observed by vertical scanning interferometry. Further, we observed accumulation of proteins at the electrode sites following conditioning in the presence of serum. Significance. This study demonstrates the in vitro biocompatibility of commercially available thick-film printing materials. The printing technique is both simple and versatile, with layouts readily modified to produce customized electrode arrays. Thick-film electrode arrays are an attractive tool that may be implemented for general tissue engineering and neuroscience research.

Inferring Soil Moisture Memory from Streamflow Observations Using a Simple Water Balance Model

NASA Technical Reports Server (NTRS)

Orth, Rene; Koster, Randal Dean; Seneviratne, Sonia I.

2013-01-01

Soil moisture is known for its integrative behavior and resulting memory characteristics. Soil moisture anomalies can persist for weeks or even months into the future, making initial soil moisture a potentially important contributor to skill in weather forecasting. A major difficulty when investigating soil moisture and its memory using observations is the sparse availability of long-term measurements and their limited spatial representativeness. In contrast, there is an abundance of long-term streamflow measurements for catchments of various sizes across the world. We investigate in this study whether such streamflow measurements can be used to infer and characterize soil moisture memory in respective catchments. Our approach uses a simple water balance model in which evapotranspiration and runoff ratios are expressed as simple functions of soil moisture; optimized functions for the model are determined using streamflow observations, and the optimized model in turn provides information on soil moisture memory on the catchment scale. The validity of the approach is demonstrated with data from three heavily monitored catchments. The approach is then applied to streamflow data in several small catchments across Switzerland to obtain a spatially distributed description of soil moisture memory and to show how memory varies, for example, with altitude and topography.

Digital Posturography Games Correlate with Gross Motor Function in Children with Cerebral Palsy.

PubMed

Bingham, Peter M; Calhoun, Barbara

2015-04-01

This pilot study aimed to assess whether performance on posturography games correlates with the Gross Motor Function Measure (GMFM) in children with cerebral palsy. Simple games using static posturography technology allowed subjects to control screen events via postural sway. Game performance was compared with GMFMs using correlation analysis in a convenience sample of nine girls and six boys with cerebral palsy. Likert scales were used to obtain subjective responses to the balance games. GMFM scores correlated with game performance, especially measures emphasizing rhythmic sway. Twelve of the 15 subjects enjoyed the game and asserted an interest in playing again. Digital posturography games engage children with cerebral palsy in balance tasks, provide visual feedback in a balance control task, and have the potential to increase autonomy in balance control training among pediatric patients with cerebral palsy. This approach can support the relationship between child and therapist. The potential for interactive posturography to complement the assessment and treatment of balance in cerebral palsy bears continuing study.

Load Balancing Strategies for Multiphase Flows on Structured Grids

NASA Astrophysics Data System (ADS)

Olshefski, Kristopher; Owkes, Mark

2017-11-01

The computation time required to perform large simulations of complex systems is currently one of the leading bottlenecks of computational research. Parallelization allows multiple processing cores to perform calculations simultaneously and reduces computational times. However, load imbalances between processors waste computing resources as processors wait for others to complete imbalanced tasks. In multiphase flows, these imbalances arise due to the additional computational effort required at the gas-liquid interface. However, many current load balancing schemes are only designed for unstructured grid applications. The purpose of this research is to develop a load balancing strategy while maintaining the simplicity of a structured grid. Several approaches are investigated including brute force oversubscription, node oversubscription through Message Passing Interface (MPI) commands, and shared memory load balancing using OpenMP. Each of these strategies are tested with a simple one-dimensional model prior to implementation into the three-dimensional NGA code. Current results show load balancing will reduce computational time by at least 30%.

A well-balanced finite volume scheme for the Euler equations with gravitation. The exact preservation of hydrostatic equilibrium with arbitrary entropy stratification

NASA Astrophysics Data System (ADS)

Käppeli, R.; Mishra, S.

2016-03-01

Context. Many problems in astrophysics feature flows which are close to hydrostatic equilibrium. However, standard numerical schemes for compressible hydrodynamics may be deficient in approximating this stationary state, where the pressure gradient is nearly balanced by gravitational forces. Aims: We aim to develop a second-order well-balanced scheme for the Euler equations. The scheme is designed to mimic a discrete version of the hydrostatic balance. It therefore can resolve a discrete hydrostatic equilibrium exactly (up to machine precision) and propagate perturbations, on top of this equilibrium, very accurately. Methods: A local second-order hydrostatic equilibrium preserving pressure reconstruction is developed. Combined with a standard central gravitational source term discretization and numerical fluxes that resolve stationary contact discontinuities exactly, the well-balanced property is achieved. Results: The resulting well-balanced scheme is robust and simple enough to be very easily implemented within any existing computer code that solves time explicitly or implicitly the compressible hydrodynamics equations. We demonstrate the performance of the well-balanced scheme for several astrophysically relevant applications: wave propagation in stellar atmospheres, a toy model for core-collapse supernovae, convection in carbon shell burning, and a realistic proto-neutron star.

Determination of recharge fraction of injection water in combined abstraction-injection wells using continuous radon monitoring.

PubMed

Lee, Kil Yong; Kim, Yong-Chul; Cho, Soo Young; Kim, Seong Yun; Yoon, Yoon Yeol; Koh, Dong Chan; Ha, Kyucheol; Ko, Kyung-Seok

2016-12-01

The recharge fractions of injection water in combined abstraction-injection wells (AIW) were determined using continuous radon monitoring and radon mass balance model. The recharge system consists of three combined abstraction-injection wells, an observation well, a collection tank, an injection tank, and tubing for heating and transferring used groundwater. Groundwater was abstracted from an AIW and sprayed on the water-curtain heating facility and then the used groundwater was injected into the same AIW well by the recharge system. Radon concentrations of fresh groundwater in the AIWs and of used groundwater in the injection tank were measured continuously using a continuous radon monitoring system. Radon concentrations of fresh groundwater in the AIWs and used groundwater in the injection tank were in the ranges of 10,830-13,530 Bq/m 3 and 1500-5600 Bq/m 3 , respectively. A simple radon mass balance model was developed to estimate the recharge fraction of used groundwater in the AIWs. The recharge fraction in the 3 AIWs was in the range of 0.595-0.798. The time series recharge fraction could be obtained using the continuous radon monitoring system with a simple radon mass balance model. The results revealed that the radon mass balance model using continuous radon monitoring was effective for determining the time series recharge fractions in AIWs as well as for characterizing the recharge system. Copyright © 2016 Elsevier Ltd. All rights reserved.

Transport of pollutants considered from the point of view of a short and medium range-material balance

Treesearch

Michel Benaire

1976-01-01

Episodical long-range transport is the quasi-instantaneous peak event. It does not express the total dosage of pollutant carried over from the source area to some distant place. The purpose of the present paper is to obtain an average material balance of a pollutant leaving a given area. Available information from the OECD "Long Range Transport of Air Pollutants...

Defense Departmental Reporting System-Budgetary Was Not Effectively Implemented for the Army General Fund

DTIC Science & Technology

2012-05-31

or events. Unsupported journal vouchers increase the risk of materially misstated balances reported on the AGF financial statements. DFAS...with U.S. generally accepted accounting principles and that the Army automated systems did not support material amounts on the financial statements...files, abnormal balance detection , journal vouchers, and reconciliations between Army and OMB SF 133s and the Statements of Budgetary Resources

Association of balance, strength, and power measures in young adults.

PubMed

Muehlbauer, Thomas; Gollhofer, Albert; Granacher, Urs

2013-03-01

The purpose of this study was to investigate the relationship between variables of static/dynamic balance, isometric strength, and power. Twenty-seven young healthy adults (mean age: 23 ± 4 years) performed measurements of static (unperturbed)/dynamic (perturbed) balance, isometric strength (i.e., maximal isometric torque [MIT]; rate of torque development [RTD] of the plantar flexor), and power (i.e., countermovement jump [CMJ] height and power). No significant associations were found between variables of static and dynamic balance (r = -0.090 to +0.329, p > 0.05) and between measures of static/dynamic balance and isometric strength (r = +0.041 to +0.387, p > 0.05) and static/dynamic balance and power (r = -0.076 to +0.218, p > 0.05). Significant positive correlations (r) were detected between variables of power and isometric strength ranging from +0.458 to +0.689 (p < 0.05). Furthermore, simple regression analyses revealed that a 10% increase in mean CMJ height (4.1 cm) was associated with 22.9 N·m and 128.4 N·m·s better MIT and RTD, respectively. The nonsignificant correlation between static and dynamic balance measures and between static/dynamic balance, isometric strength, and power variables implies that these capacities may be independent of each other and may have to be tested and trained complementarily.

Comparison of Objective Measures for Predicting Perceptual Balance and Visual Aesthetic Preference

PubMed Central

Hübner, Ronald; Fillinger, Martin G.

2016-01-01

The aesthetic appreciation of a picture largely depends on the perceptual balance of its elements. The underlying mental mechanisms of this relation, however, are still poorly understood. For investigating these mechanisms, objective measures of balance have been constructed, such as the Assessment of Preference for Balance (APB) score of Wilson and Chatterjee (2005). In the present study we examined the APB measure and compared it to an alternative measure (DCM; Deviation of the Center of “Mass”) that represents the center of perceptual “mass” in a picture and its deviation from the geometric center. Additionally, we applied measures of homogeneity and of mirror symmetry. In a first experiment participants had to rate the balance and symmetry of simple pictures, whereas in a second experiment different participants rated their preference (liking) for these pictures. In a third experiment participants rated the balance as well as the preference of new pictures. Altogether, the results show that DCM scores accounted better for balance ratings than APB scores, whereas the opposite held with respect to preference. Detailed analyses revealed that these results were due to the fact that aesthetic preference does not only depend on balance but also on homogeneity, and that the APB measure takes this feature into account. PMID:27014143

Spent Nuclear Fuel (SNF) Project Canister Storage Building (CSB) Process Flow Diagram Mass Balance Calculations

DOE Office of Scientific and Technical Information (OSTI.GOV)

KLEM, M.J.

2000-05-11

The purpose of these calculations is to develop the material balances for documentation of the Canister Storage Building (CSB) Process Flow Diagram (PFD) and future reference. The attached mass balances were prepared to support revision two of the PFD for the CSB. The calculations refer to diagram H-2-825869.

Balancing Detection and Eradication for Control of Epidemics: Sudden Oak Death in Mixed-Species Stands

PubMed Central

Ndeffo Mbah, Martial L.; Gilligan, Christopher A.

2010-01-01

Culling of infected individuals is a widely used measure for the control of several plant and animal pathogens but culling first requires detection of often cryptically-infected hosts. In this paper, we address the problem of how to allocate resources between detection and culling when the budget for disease management is limited. The results are generic but we motivate the problem for the control of a botanical epidemic in a natural ecosystem: sudden oak death in mixed evergreen forests in coastal California, in which species composition is generally dominated by a spreader species (bay laurel) and a second host species (coast live oak) that is an epidemiological dead-end in that it does not transmit infection but which is frequently a target for preservation. Using a combination of an epidemiological model for two host species with a common pathogen together with optimal control theory we address the problem of how to balance the allocation of resources for detection and epidemic control in order to preserve both host species in the ecosystem. Contrary to simple expectations our results show that an intermediate level of detection is optimal. Low levels of detection, characteristic of low effort expended on searching and detection of diseased trees, and high detection levels, exemplified by the deployment of large amounts of resources to identify diseased trees, fail to bring the epidemic under control. Importantly, we show that a slight change in the balance between the resources allocated to detection and those allocated to control may lead to drastic inefficiencies in control strategies. The results hold when quarantine is introduced to reduce the ingress of infected material into the region of interest. PMID:20856850

A theory of wheelchair wheelie performance.

PubMed

Kauzlarich, J J; Thacker, J G

1987-01-01

The results of this analytical study of wheelchair wheelie performance can be summarized into two wheelchair design equations, or rules of thumb, as developed in the paper. The equation containing the significant parameters involved in popping a wheelie for curb climbing is: fh = 0.8 mg theta c.g. [A] where fh is handrim force, m is the mass of the wheelchair + user less rear wheels, g is acceleration of gravity (9.807 m/s2), and theta c.g. is "c.g. angle," i.e., the angle between the vertical through the rear axle and a line connecting the rear axle and the system center-of-gravity. Equation [A] shows that reducing the mass and/or the c.g. angle will make it easier to pop a wheelie. The c.g. angle is reduced by moving the rear axle position forward on the wheelchair. Wheelie balance is the other aspect of performance considered; where the user balances the wheelchair on the rear wheels for going down curbs or just for fun. The ease with which a system can be controlled (balanced) is related to the static stability of the system. The static stability is defined as: omega 2 = mgl/J [B] where J is the mass moment of inertia at the center of gravity of the system about the direction perpendicular to the sideframe. For better wheelchair control during wheelchair balance the static stability should be reduced. Measurements of the value for the polar mass moment of inertia for a typical wheelchair + user of m = 90 kg was found to be J = 8.7 kg-m2. In order to decrease the value of the static stability, Equation [B], one can increase J or decrease m and/or l, where l is the distance from the rear axle to the c.g. of the system. It is also shown that balancing a rod in the palm of the hand (inverted pendulum) is a mathematical problem similar to the wheelie balance problem, and a rod of length 1.56 meters is similar to a wheelchair + user system mass of 90 kg. However, balancing a rod is done primarily by using visual perception, whereas wheelie balance involves human joint proprioceptors and visual plus vestibular (inner ear) perception. Thus, a simple test of determining the shortest length of rod one can balance in the palm of the hand (plus measuring handrim force capability and simple reaction time) may indicate if a wheelchair user will find it easy to do a wheelie balance.

Twelve essential tools for living the life of whole person health care.

PubMed

Schlitz, Marilyn; Valentina, Elizabeth

2013-01-01

The integration of body, mind, and spirit has become a key dimension of health education and disease prevention and treatment; however, our health care system remains primarily disease centered. Finding simple steps to help each of us find our own balance can improve our lives, our work, and our relationships. On the basis of interviews with health care experts at the leading edge of the new model of medicine, this article identifies simple tools to improve the health of patients and caregivers.

Experiments in balance with a 2D one-legged hopping machine

NASA Astrophysics Data System (ADS)

Raibert, M. H.; Brown, H. B., Jr.

1984-03-01

The ability to balance is important to the mobility obtained by legged creatures found in nature, and may someday lead to versatile legged vehicles. In order to study the role of balance in legged locomotion and to develop appropriate control strategies, a 2D hopping machine was constructed for experimentation. The machine has one leg on which it hops and runs, making balance a prime consideration. Control of the machine's locomotion was decomposed into three separate parts: a vertical height control part, a horizontal velocity part, and an angular attitude control part. Experiments showed that the three part control scheme, while very simple to implement, was powerful enough to permit the machine to hop in place, to run at a desired rate, to translate from place to place, and to leap over obstacles. Results from modeling and computer simulation of a similar one-legged device are described by Raibert (1983).

Community-based adapted tango dancing for individuals with Parkinson's disease and older adults.

PubMed

Hackney, Madeleine E; Hackney, Madeleine; McKee, Kathleen

2014-12-09

Adapted tango dancing improves mobility and balance in older adults and additional populations with balance impairments. It is composed of very simple step elements. Adapted tango involves movement initiation and cessation, multi-directional perturbations, varied speeds and rhythms. Focus on foot placement, whole body coordination, and attention to partner, path of movement, and aesthetics likely underlie adapted tango's demonstrated efficacy for improving mobility and balance. In this paper, we describe the methodology to disseminate the adapted tango teaching methods to dance instructor trainees and to implement the adapted tango by the trainees in the community for older adults and individuals with Parkinson's Disease (PD). Efficacy in improving mobility (measured with the Timed Up and Go, Tandem stance, Berg Balance Scale, Gait Speed and 30 sec chair stand), safety and fidelity of the program is maximized through targeted instructor and volunteer training and a structured detailed syllabus outlining class practices and progression.

Nuclear Disarmament.

ERIC Educational Resources Information Center

Johnson, Christopher

1982-01-01

Material about nuclear disarmament and the arms race should be included in secondary school curricula. Teachers can present this technical, controversial, and frightening material in a balanced and comprehensible way. Resources for instructional materials are listed. (PP)

78 FR 67225 - Amendments to Material Control and Accounting Regulations

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-08

... Amendments to Material Control and Accounting Regulations AGENCY: Nuclear Regulatory Commission. ACTION... for material control and accounting (MC&A) of special nuclear material (SNM). The goal of this... added to designate material balance areas, item control areas, and custodians? N. Why would calendar...

Force instrumentation for cryogenic wind tunnels using one-piece strain-gage balances

NASA Technical Reports Server (NTRS)

Ferris, A. T.

1980-01-01

The use of cryogenic temperatures in wind tunnels to achieve high Reynolds numbers has imposed a harsh operating environment on the force balance. Laboratory tests were conducted to study the effect cryogenic temperatures have on balance materials, gages, wiring, solder, adhesives, and moisture proofing. Wind tunnel tests were conducted using a one piece three component balance to verify laboratory results. These initial studies indicate that satisfactory force data can be obtained under steady state conditions.

An egalitarian network model for the emergence of simple and complex cells in visual cortex

PubMed Central

Tao, Louis; Shelley, Michael; McLaughlin, David; Shapley, Robert

2004-01-01

We explain how simple and complex cells arise in a large-scale neuronal network model of the primary visual cortex of the macaque. Our model consists of ≈4,000 integrate-and-fire, conductance-based point neurons, representing the cells in a small, 1-mm2 patch of an input layer of the primary visual cortex. In the model the local connections are isotropic and nonspecific, and convergent input from the lateral geniculate nucleus confers cortical cells with orientation and spatial phase preference. The balance between lateral connections and lateral geniculate nucleus drive determines whether individual neurons in this recurrent circuit are simple or complex. The model reproduces qualitatively the experimentally observed distributions of both extracellular and intracellular measures of simple and complex response. PMID:14695891

Causal electric charge diffusion and balance functions in relativistic heavy-ion collisions

NASA Astrophysics Data System (ADS)

Kapusta, Joseph I.; Plumberg, Christopher

2018-01-01

We study the propagation and diffusion of electric charge fluctuations in high-energy heavy-ion collisions using the Cattaneo form for the dissipative part of the electric current. As opposed to the ordinary diffusion equation this form limits the speed at which charge can propagate. Including the noise term in the current, which arises uniquely from the fluctuation-dissipation theorem, we calculate the balance functions for charged hadrons in a simple 1+1-dimensional Bjorken hydrodynamical model. Limiting the speed of propagation of charge fluctuations increases the height and reduces the width of these balance functions when plotted versus rapidity. We also estimate the numerical value of the associated diffusion time constant from anti-de Sitter-space/conformal-field theory.

Multi-level characterization of balanced inhibitory-excitatory cortical neuron network derived from human pluripotent stem cells.

PubMed

Nadadhur, Aishwarya G; Emperador Melero, Javier; Meijer, Marieke; Schut, Desiree; Jacobs, Gerbren; Li, Ka Wan; Hjorth, J J Johannes; Meredith, Rhiannon M; Toonen, Ruud F; Van Kesteren, Ronald E; Smit, August B; Verhage, Matthijs; Heine, Vivi M

2017-01-01

Generation of neuronal cultures from induced pluripotent stem cells (hiPSCs) serve the studies of human brain disorders. However we lack neuronal networks with balanced excitatory-inhibitory activities, which are suitable for single cell analysis. We generated low-density networks of hPSC-derived GABAergic and glutamatergic cortical neurons. We used two different co-culture models with astrocytes. We show that these cultures have balanced excitatory-inhibitory synaptic identities using confocal microscopy, electrophysiological recordings, calcium imaging and mRNA analysis. These simple and robust protocols offer the opportunity for single-cell to multi-level analysis of patient hiPSC-derived cortical excitatory-inhibitory networks; thereby creating advanced tools to study disease mechanisms underlying neurodevelopmental disorders.

An Integrated Fuselage-Sting Balance for a Sonic-Boom Wind-Tunnel Model

NASA Technical Reports Server (NTRS)

Mack, Robert J.

2004-01-01

Measured and predicted pressure signatures from a lifting wind-tunnel model can be compared when the lift on the model is accurately known. The model's lift can be set by bending the support sting to a desired angle of attack. This method is simple in practice, but difficult to accurately apply. A second method is to build a normal force/pitching moment balance into the aft end of the sting, and use an angle-of-attack mechanism to set model attitude. In this report, a method for designing a sting/balance into the aft fuselage/sting of a sonic-boom model is described. A computer code is given, and a sample sting design is outlined to demonstrate the method.

Refining of Military Jet Fuels from Shale Oil. Part II. Volume III. Above Ground Shale Oil Process Data.

DTIC Science & Technology

1982-03-01

system. Regenerator flue gas composi- tion, spent catalyst carbon content and regenerated cata- lyst content are monitored for material balance purposes...and good material balance closures obtained. During each run pro- duct gas samples, regenerator flue gas samples, spent and -85- regenerated...TEMPERATURE DEPENDENCE OF DENITROGENATION AT 2 LHSV ON CO/MO ......................... 26 111-2 TEMPERATURE DEPENDENCE OF DESULFURIZATION AT 2 LHSV ON

DOD Financial Management: Ongoing Challenges with Reconciling Navy and Marine Corps Fund Balance with Treasury

DTIC Science & Technology

2011-12-01

significant deficiencies, that results in more than a remote likelihood that a material misstatement of the financial statements will not be prevented or...reconciliations of FBWT collection and disbursement activity, the amount of funds available for expenditure may contain material misstatements ; related...10 GAO-12-132 Fund Balance Reconciliations misstated , and the Department of the Navy is at increased risk of Antideficiency Act violations.31 • The

A two-phase micromorphic model for compressible granular materials

NASA Astrophysics Data System (ADS)

Paolucci, Samuel; Li, Weiming; Powers, Joseph

2009-11-01

We introduce a new two-phase continuum model for compressible granular material based on micromorphic theory and treat it as a two-phase mixture with inner structure. By taking an appropriate number of moments of the local micro scale balance equations, the average phase balance equations result from a systematic averaging procedure. In addition to equations for mass, momentum and energy, the balance equations also include evolution equations for microinertia and microspin tensors. The latter equations combine to yield a general form of a compaction equation when the material is assumed to be isotropic. When non-linear and inertial effects are neglected, the generalized compaction equation reduces to that originally proposed by Bear and Nunziato. We use the generalized compaction equation to numerically model a mixture of granular high explosive and interstitial gas. One-dimensional shock tube and piston-driven solutions are presented and compared with experimental results and other known solutions.

Anaerobic digestion of source-segregated domestic food waste: performance assessment by mass and energy balance.

PubMed

Banks, Charles J; Chesshire, Michael; Heaven, Sonia; Arnold, Rebecca

2011-01-01

An anaerobic digester receiving food waste collected mainly from domestic kitchens was monitored over a period of 426 days. During this time information was gathered on the waste input material, the biogas production, and the digestate characteristics. A mass balance accounted for over 90% of the material entering the plant leaving as gaseous or digestate products. A comprehensive energy balance for the same period showed that for each tonne of input material the potential recoverable energy was 405 kWh. Biogas production in the digester was stable at 642 m3 tonne(-1) VS added with a methane content of around 62%. The nitrogen in the food waste input was on average 8.9 kg tonne(-1). This led to a high ammonia concentration in the digester which may have been responsible for the accumulation of volatile fatty acids that was also observed. Copyright © 2010 Elsevier Ltd. All rights reserved.

A coupled problem of finite deformation and flow in porous media

NASA Astrophysics Data System (ADS)

Moussa, A. B.

1980-06-01

A theory for deformation and two phase flow in porous media was developed. Equations of balance of mass, momentum, moment of momentum and energy for each constituent were postulated. These led to equivalent balance equations for the mixture as a whole to which an entropy production inequality was also postulated. The formulation was then applied to the silage material. A constitutive theory was developed for the mixture. General appropriate constitutive assumptions were suggested and made to satisfy the axiom of material objectivity and entropy production inequality. Material incompressibility was defined and introduced into the general form of constitutive relations.

Single Logon: balancing security and healthcare productivity.

PubMed

Sapp, Margaret J; Behrens, Terrence L

2004-01-01

Mayo Single Logon (MSL) has faced the traditional dilemma that is painful to all IT organizations because it forces the tradeoff between user productivity and security. Recent regulatory initiatives, such as HIPAA, have caused the issue of security to take on more importance, forcing organizations to revisit the balance of security and productivity. MSL is a security application that brokers user credentials and facilitates desktop security. The simple design, functionality and stability have allowed MSL to speed up user productivity, keep satisfaction high and help solve many security initiatives.

Development of specification for the superpave simple performance tests (SPT).

DOT National Transportation Integrated Search

2009-05-16

This report describes the development and establishment of a proposed Simple Performance : Test (SPT) specification in order to contribute to the asphalt materials technology in the state of : Michigan. The properties and characteristic of materials,...

Coupling Climate Models and Forward-Looking Economic Models

NASA Astrophysics Data System (ADS)

Judd, K.; Brock, W. A.

2010-12-01

Authors: Dr. Kenneth L. Judd, Hoover Institution, and Prof. William A. Brock, University of Wisconsin Current climate models range from General Circulation Models (GCM’s) with millions of degrees of freedom to models with few degrees of freedom. Simple Energy Balance Climate Models (EBCM’s) help us understand the dynamics of GCM’s. The same is true in economics with Computable General Equilibrium Models (CGE’s) where some models are infinite-dimensional multidimensional differential equations but some are simple models. Nordhaus (2007, 2010) couples a simple EBCM with a simple economic model. One- and two- dimensional ECBM’s do better at approximating damages across the globe and positive and negative feedbacks from anthroprogenic forcing (North etal. (1981), Wu and North (2007)). A proper coupling of climate and economic systems is crucial for arriving at effective policies. Brock and Xepapadeas (2010) have used Fourier/Legendre based expansions to study the shape of socially optimal carbon taxes over time at the planetary level in the face of damages caused by polar ice cap melt (as discussed by Oppenheimer, 2005) but in only a “one dimensional” EBCM. Economists have used orthogonal polynomial expansions to solve dynamic, forward-looking economic models (Judd, 1992, 1998). This presentation will couple EBCM climate models with basic forward-looking economic models, and examine the effectiveness and scaling properties of alternative solution methods. We will use a two dimensional EBCM model on the sphere (Wu and North, 2007) and a multicountry, multisector regional model of the economic system. Our aim will be to gain insights into intertemporal shape of the optimal carbon tax schedule, and its impact on global food production, as modeled by Golub and Hertel (2009). We will initially have limited computing resources and will need to focus on highly aggregated models. However, this will be more complex than existing models with forward-looking economic modules, and the initial models will help guide the construction of more refined models that can effectively use more powerful computational environments to analyze economic policies related to climate change. REFERENCES Brock, W., Xepapadeas, A., 2010, “An Integration of Simple Dynamic Energy Balance Climate Models and Ramsey Growth Models,” Department of Economics, University of Wisconsin, Madison, and University of Athens. Golub, A., Hertel, T., etal., 2009, “The opportunity cost of land use and the global potential for greenhouse gas mitigation in agriculture and forestry,” RESOURCE AND ENERGY ECONOMICS, 31, 299-319. Judd, K., 1992, “Projection methods for solving aggregate growth models,” JOURNAL OF ECONOMIC THEORY, 58: 410-52. Judd, K., 1998, NUMERICAL METHODS IN ECONOMICS, MIT Press, Cambridge, Mass. Nordhaus, W., 2007, A QUESTION OF BALANCE: ECONOMIC MODELS OF CLIMATE CHANGE, Yale University Press, New Haven, CT. North, G., R., Cahalan, R., Coakely, J., 1981, “Energy balance climate models,” REVIEWS OF GEOPHYSICS AND SPACE PHYSICS, Vol. 19, No. 1, 91-121, February Wu, W., North, G. R., 2007, “Thermal decay modes of a 2-D energy balance climate model,” TELLUS, 59A, 618-626.

Review of Potential Wind Tunnel Balance Technologies

NASA Technical Reports Server (NTRS)

Burns, Devin E.; Williams, Quincy L.; Phillips, Ben D.; Commo, Sean A.; Ponder, Jonathon D.

2016-01-01

This manuscript reviews design, manufacture, materials, sensors, and data acquisition technologies that may benefit wind tunnel balances for the aerospace research community. Current state-of-the-art practices are used as the benchmark to consider advancements driven by researcher and facility needs. Additive manufacturing is highlighted as a promising alternative technology to conventional fabrication and has the potential to reduce both the cost and time required to manufacture force balances. Material alternatives to maraging steels are reviewed. Sensor technologies including piezoresistive, piezoelectric, surface acoustic wave, and fiber optic are compared to traditional foil based gages to highlight unique opportunities and shared challenges for implementation in wind tunnel environments. Finally, data acquisition systems that could be integrated into force balances are highlighted as a way to simplify the user experience and improve data quality. In summary, a rank ordering is provided to support strategic investment in exploring the technologies reviewed in this manuscript.

Regression Analysis by Example. 5th Edition

ERIC Educational Resources Information Center

Chatterjee, Samprit; Hadi, Ali S.

2012-01-01

Regression analysis is a conceptually simple method for investigating relationships among variables. Carrying out a successful application of regression analysis, however, requires a balance of theoretical results, empirical rules, and subjective judgment. "Regression Analysis by Example, Fifth Edition" has been expanded and thoroughly…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Prior to 1978, the Wilsonville Advanced Coal Liquefaction facility material balance surrounded only the thermal liquefaction unit and involved analyses of only the slurry stream and individual gas streams. The distillate solvent yield was determined by difference. Subsequently, several modifications and additional process units were introduced to this single unit system. With the inclusion of the deashing unit in 1978 and the catalytic hydrogenation unit in 1981, the process has evolved into a sophisticated two-stage coal liquefaction process and has the potential for various modes of integration. This report presents an elemental balancing procedure and a simplified presentation format thatmore » is sufficiently flexible to meet current and future needs. The development of the elemental balancing technique and the relevant computer programs to handle the calculations have been addressed. This will be useful in modelling individual unit performance as well as determining the impact of each unit on the overall liquefaction system, provided the units are on a steady-state basis. Five different material balance envelopes are defined. Three of these envelopes pertain to the individual units (the thermal liquefaction or TL unit, the Critical Solvent Deashing or CSD unit and the H-Oil Ebullated Bed Hydrotreating or HTR unit). The fourth or single stage material balance envelope combines the TL and CSD units. The fifth envelope is the two-stage configuration combining all three units. 3 references.« less

Cryogenic balances for the US NTF

NASA Technical Reports Server (NTRS)

Ferris, Alice T.

1989-01-01

Force balances were used to obtain aerodynamic data in the National Transonic Facility (NTF) wind tunnel since it became operational in 1983. These balances were designed, fabricated, gaged, and calibrated to Langley Research Center's specifications to operate over the temperature range of -320 F to +140 F without thermal control. Some of the materials and procedures developed to obtain a balance that would perform in this environment are reviewed. The degree of success in using these balances thus far is reported. Some of the problem areas that need additional work are specified and some of the progress addressing these problems is described.

A contribution to the validation of the Wii Balance Board for the assessment of standing balance.

PubMed

Pavan, Piero; Cardaioli, Matteo; Ferri, Ilaria; Gobbi, Erica; Carraro, Attilio

2015-01-01

Valid and reliable accessible measures of balance are required in a health-related fitness test battery, both in the general population and in groups with special needs. For this purpose, the capability of the Wii Balance Board (WBB) in evaluating standing balance was analysed and compared with a laboratory-graded force platform (FP). A 30-s double limb standing test with open and closed eyes was performed by 28 individuals (12 male and 16 female, mean age = 23.8, SD = ±2.7 years). A simple method of acquisition of the centre of pressure (CoP) over time was applied to compare WBB and FP simultaneously on the same signal. User-defined software was developed to obtain the CoP from WBB over time and the resulting related measures and graphical representations. The comparison of measures, such as sway path and maximum oscillations along the anterior-posterior and medial-lateral direction, obtained with the FP and the WBB shows that the latter, in conjunction with the user-defined developed software, can be appropriate, considering prescribed limits, and an easy-to-use tool for evaluating standing balance.

A balanced motor primitive framework can simultaneously explain motor learning in unimanual and bimanual movements.

PubMed

Takiyama, Ken; Sakai, Yutaka

2017-02-01

Certain theoretical frameworks have successfully explained motor learning in either unimanual or bimanual movements. However, no single theoretical framework can comprehensively explain motor learning in both types of movement because the relationship between these two types of movement remains unclear. Although our recent model of a balanced motor primitive framework attempted to simultaneously explain motor learning in unimanual and bimanual movements, this model focused only on a limited subset of bimanual movements and therefore did not elucidate the relationships between unimanual movements and various bimanual movements. Here, we extend the balanced motor primitive framework to simultaneously explain motor learning in unimanual and various bimanual movements as well as the transfer of learning effects between unimanual and various bimanual movements; these phenomena can be simultaneously explained if the mean activity of each primitive for various unimanual movements is balanced with the corresponding mean activity for various bimanual movements. Using this balanced condition, we can reproduce the results of prior behavioral and neurophysiological experiments. Furthermore, we demonstrate that the balanced condition can be implemented in a simple neural network model. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Effect of Surface Nonequilibrium Thermochemistry in Simulation of Carbon Based Ablators

NASA Technical Reports Server (NTRS)

Chen, Yih-Kang; Gokcen, Tahir

2012-01-01

This study demonstrates that coupling of a material thermal response code and a flow solver using finite-rate gas/surface interaction model provides time-accurate solutions for multidimensional ablation of carbon based charring ablators. The material thermal response code used in this study is the Two-dimensional Implicit Thermal Response and Ablation Program (TITAN), which predicts charring material thermal response and shape change on hypersonic space vehicles. Its governing equations include total energy balance, pyrolysis gas momentum conservation, and a three-component decomposition model. The flow code solves the reacting Navier-Stokes equations using Data Parallel Line Relaxation (DPLR) method. Loose coupling between material response and flow codes is performed by solving the surface mass balance in DPLR and the surface energy balance in TITAN. Thus, the material surface recession is predicted by finite-rate gas/surface interaction boundary conditions implemented in DPLR, and the surface temperature and pyrolysis gas injection rate are computed in TITAN. Two sets of gas/surface interaction chemistry between air and carbon surface developed by Park and Zhluktov, respectively, are studied. Coupled fluid-material response analyses of stagnation tests conducted in NASA Ames Research Center arc-jet facilities are considered. The ablating material used in these arc-jet tests was a Phenolic Impregnated Carbon Ablator (PICA). Computational predictions of in-depth material thermal response and surface recession are compared with the experimental measurements for stagnation cold wall heat flux ranging from 107 to 1100 Watts per square centimeter.

Effect of Non-Equilibrium Surface Thermochemistry in Simulation of Carbon Based Ablators

NASA Technical Reports Server (NTRS)

Chen, Yih-Kanq; Gokcen, Tahir

2012-01-01

This study demonstrates that coupling of a material thermal response code and a flow solver using non-equilibrium gas/surface interaction model provides time-accurate solutions for the multidimensional ablation of carbon based charring ablators. The material thermal response code used in this study is the Two-dimensional Implicit Thermal-response and AblatioN Program (TITAN), which predicts charring material thermal response and shape change on hypersonic space vehicles. Its governing equations include total energy balance, pyrolysis gas mass conservation, and a three-component decomposition model. The flow code solves the reacting Navier-Stokes equations using Data Parallel Line Relaxation (DPLR) method. Loose coupling between the material response and flow codes is performed by solving the surface mass balance in DPLR and the surface energy balance in TITAN. Thus, the material surface recession is predicted by finite-rate gas/surface interaction boundary conditions implemented in DPLR, and the surface temperature and pyrolysis gas injection rate are computed in TITAN. Two sets of nonequilibrium gas/surface interaction chemistry between air and the carbon surface developed by Park and Zhluktov, respectively, are studied. Coupled fluid-material response analyses of stagnation tests conducted in NASA Ames Research Center arc-jet facilities are considered. The ablating material used in these arc-jet tests was Phenolic Impregnated Carbon Ablator (PICA). Computational predictions of in-depth material thermal response and surface recession are compared with the experimental measurements for stagnation cold wall heat flux ranging from 107 to 1100 Watts per square centimeter.

Understanding uncertainty in precipitation changes in a balanced perturbed-physics ensemble under multiple climate forcings

NASA Astrophysics Data System (ADS)

Millar, R.; Ingram, W.; Allen, M. R.; Lowe, J.

2013-12-01

Temperature and precipitation patterns are the climate variables with the greatest impacts on both natural and human systems. Due to the small spatial scales and the many interactions involved in the global hydrological cycle, in general circulation models (GCMs) representations of precipitation changes are subject to considerable uncertainty. Quantifying and understanding the causes of uncertainty (and identifying robust features of predictions) in both global and local precipitation change is an essential challenge of climate science. We have used the huge distributed computing capacity of the climateprediction.net citizen science project to examine parametric uncertainty in an ensemble of 20,000 perturbed-physics versions of the HadCM3 general circulation model. The ensemble has been selected to have a control climate in top-of-atmosphere energy balance [Yamazaki et al. 2013, J.G.R.]. We force this ensemble with several idealised climate-forcing scenarios including carbon dioxide step and transient profiles, solar radiation management geoengineering experiments with stratospheric aerosols, and short-lived climate forcing agents. We will present the results from several of these forcing scenarios under GCM parametric uncertainty. We examine the global mean precipitation energy budget to understand the robustness of a simple non-linear global precipitation model [Good et al. 2012, Clim. Dyn.] as a better explanation of precipitation changes in transient climate projections under GCM parametric uncertainty than a simple linear tropospheric energy balance model. We will also present work investigating robust conclusions about precipitation changes in a balanced ensemble of idealised solar radiation management scenarios [Kravitz et al. 2011, Atmos. Sci. Let.].

The ω-3 and ω-6 fats in meals: a proposal for a simple new label.

PubMed

Turner, Nigel; Mitchell, Todd W; Else, Paul L; Hulbert, A J

2011-06-01

The ω-3 and ω-6 polyunsaturated fatty acids (PUFAs) are separate essential dietary fatty acids that play a key role in many physiologic processes in higher animals. The content of these PUFAs is relatively well described for many individual food components. Our goal in this study was to analyze the PUFA content of whole meals and produce a simple measurement to estimate the intake of these fatty acids. The fatty acid profile and macronutrient composition were determined for a range of fast food, cuisine (restaurant-prepared), and home-prepared whole meals commonly consumed by Australians. Across the different meals there was significant variation in protein (4-fold), fat (13-fold), and carbohydrate (23-fold) contents. With regard to the fatty acid profile, saturated and monounsaturated fatty acids made up approximately 80% of total fatty acids for most meals. The ω-6 PUFAs were substantially more abundant than ω-3 PUFAs for most meals. The balance of dietary ω-3 and ω-6 PUFAs is an important determinant of their metabolic effects within the body, and accordingly we calculated the percentage of the total PUFA comprised of ω-3 PUFAs and referred to this as the PUFA Balance. This parameter showed the greatest variation among the different meals (>45-fold). The relative proportions of ω-3 and ω-6 PUFAs vary greatly across meals. PUFA Balance is a useful tool that will allow individuals to more easily monitor and balance their intake of ω-3 and ω-6 fats. Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.

CONVERTING ISOTOPE RATIOS TO DIET COMPOSITION - THE USE OF MIXING MODELS

EPA Science Inventory

Investigations of wildlife foraging ecology with stable isotope analysis are increasing. Converting isotope values to proportions of different foods in a consumer's diet requires the use of mixing models. Simple mixing models based on mass balance equations have been used for d...

Analysis of Levene's Test under Design Imbalance.

ERIC Educational Resources Information Center

Keyes, Tim K.; Levy, Martin S.

1997-01-01

H. Levene (1960) proposed a heuristic test for heteroscedasticity in the case of a balanced two-way layout, based on analysis of variance of absolute residuals. Conditions under which design imbalance affects the test's characteristics are identified, and a simple correction involving leverage is proposed. (SLD)

A Thermal-based Two-Source Energy Balance Model for Estimating Evapotranspiration over Complex Canopies

USDA-ARS?s Scientific Manuscript database

Land surface temperature (LST) provides valuable information for quantifying root-zone water availability, evapotranspiration (ET) and crop condition as well as providing useful information for constraining prognostic land surface models. This presentation describes a robust but relatively simple LS...

Second Law of Thermodynamics Applied to Metabolic Networks

NASA Technical Reports Server (NTRS)

Nigam, R.; Liang, S.

2003-01-01

We present a simple algorithm based on linear programming, that combines Kirchoff's flux and potential laws and applies them to metabolic networks to predict thermodynamically feasible reaction fluxes. These law's represent mass conservation and energy feasibility that are widely used in electrical circuit analysis. Formulating the Kirchoff's potential law around a reaction loop in terms of the null space of the stoichiometric matrix leads to a simple representation of the law of entropy that can be readily incorporated into the traditional flux balance analysis without resorting to non-linear optimization. Our technique is new as it can easily check the fluxes got by applying flux balance analysis for thermodynamic feasibility and modify them if they are infeasible so that they satisfy the law of entropy. We illustrate our method by applying it to the network dealing with the central metabolism of Escherichia coli. Due to its simplicity this algorithm will be useful in studying large scale complex metabolic networks in the cell of different organisms.

Coatings on reflective mask substrates

DOEpatents

Tong, William Man-Wai; Taylor, John S.; Hector, Scott D.; Mangat, Pawitter J. S.; Stivers, Alan R.; Kofron, Patrick G.; Thompson, Matthew A.

2002-01-01

A process for creating a mask substrate involving depositing: 1) a coating on one or both sides of a low thermal expansion material EUVL mask substrate to improve defect inspection, surface finishing, and defect levels; and 2) a high dielectric coating, on the backside to facilitate electrostatic chucking and to correct for any bowing caused by the stress imbalance imparted by either other deposited coatings or the multilayer coating of the mask substrate. An film, such as TaSi, may be deposited on the front side and/or back of the low thermal expansion material before the material coating to balance the stress. The low thermal expansion material with a silicon overlayer and a silicon and/or other conductive underlayer enables improved defect inspection and stress balancing.

Design, development and applications of novel techniques for studying surface mechanical properties

NASA Technical Reports Server (NTRS)

Miyoshi, Kazuhisa

1989-01-01

Research is reviewed for the adhesion, friction, and micromechanical properties of materials and examples of the results presented. The ceramic and metallic materials studied include silicon carbide, aluminum oxide, and iron-base amorphous alloys. The design and operation of a torsion balance adapted for study of adhesion from the Cavendish balance are discussed first. The pull-off force (adhesion) and shear force (friction) required to break the interfacial junctions between contacting surfaces of the materials were examined at various temperatures in a vacuum. The surface chemistry of the materials was analyzed by X-ray photoelectron spectroscopy. Properties and environmental conditions of the surface regions which affect adhesion and friction-such as surface segregation, composition, crystal structure, surface chemistry, and temperature were also studied.

A simple daily soil-water balance model for estimating the spatial and temporal distribution of groundwater recharge in temperate humid areas

USGS Publications Warehouse

Dripps, W.R.; Bradbury, K.R.

2007-01-01

Quantifying the spatial and temporal distribution of natural groundwater recharge is usually a prerequisite for effective groundwater modeling and management. As flow models become increasingly utilized for management decisions, there is an increased need for simple, practical methods to delineate recharge zones and quantify recharge rates. Existing models for estimating recharge distributions are data intensive, require extensive parameterization, and take a significant investment of time in order to establish. The Wisconsin Geological and Natural History Survey (WGNHS) has developed a simple daily soil-water balance (SWB) model that uses readily available soil, land cover, topographic, and climatic data in conjunction with a geographic information system (GIS) to estimate the temporal and spatial distribution of groundwater recharge at the watershed scale for temperate humid areas. To demonstrate the methodology and the applicability and performance of the model, two case studies are presented: one for the forested Trout Lake watershed of north central Wisconsin, USA and the other for the urban-agricultural Pheasant Branch Creek watershed of south central Wisconsin, USA. Overall, the SWB model performs well and presents modelers and planners with a practical tool for providing recharge estimates for modeling and water resource planning purposes in humid areas. ?? Springer-Verlag 2007.

Development of a multicomponent force and moment balance for water tunnel applications, volume 1

NASA Technical Reports Server (NTRS)

Suarez, Carlos J.; Malcolm, Gerald N.; Kramer, Brian R.; Smith, Brooke C.; Ayers, Bert F.

1994-01-01

The principal objective of this research effort was to develop a multicomponent strain gauge balance to measure forces and moments on models tested in flow visualization water tunnels. An internal balance was designed that allows measuring normal and side forces, and pitching, yawing and rolling moments (no axial force). The five-components to applied loads, low interactions between the sections and no hysteresis. Static experiments (which are discussed in this Volume) were conducted in the Eidetics water tunnel with delta wings and a model of the F/A-18. Experiments with the F/A-18 model included a thorough baseline study and investigations of the effect of control surface deflections and of several Forebody Vortex Control (FVC) techniques. Results were compared to wind tunnel data and, in general, the agreement is very satisfactory. The results of the static tests provide confidence that loads can be measured accurately in the water tunnel with a relatively simple multicomponent internal balance. Dynamic experiments were also performed using the balance, and the results are discussed in detail in Volume 2 of this report.

The effect of low versus high approach-motivated positive affect on the balance between maintenance and flexibility.

PubMed

Liu, Liting; Xu, Baihua

2016-05-27

Successful goal-directed behavior in a constantly changing environment requires a balance between maintenance and flexibility. Although some studies have found that positive affect influences this balance differently than neutral affect, one recent study found that motivational intensity of positive affective states influences this balance in a cognitive set-shifting paradigm. However, working memory updating and set shifting are interrelated but distinct components of cognitive control. The present study examined the effect of low versus high approach-motivated positive affect on the balance between maintenance and flexibility in working memory. A simple cuing paradigm (the AX Continuous Performance Task) was employed, and neutral affect and high and low approach-motivated positive affect were induced using affective pictures. The results revealed that, relative to neutral affect, low approach-motivated positive affect attenuated maintenance and increased flexibility, whereas high approach-motivated positive affect promoted maintenance and decreased flexibility. These findings offer further evidence that the effects of positive affect on cognitive control are modulated by approach motivational intensity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Silicon production process evaluations

NASA Technical Reports Server (NTRS)

1982-01-01

Chemical engineering analyses involving the preliminary process design of a plant (1,000 metric tons/year capacity) to produce silicon via the technology under consideration were accomplished. Major activities in the chemical engineering analyses included base case conditions, reaction chemistry, process flowsheet, material balance, energy balance, property data, equipment design, major equipment list, production labor and forward for economic analysis. The process design package provided detailed data for raw materials, utilities, major process equipment and production labor requirements necessary for polysilicon production in each process.

Improved Analysis of Earth System Models and Observations using Simple Climate Models

NASA Astrophysics Data System (ADS)

Nadiga, B. T.; Urban, N. M.

2016-12-01

Earth system models (ESM) are the most comprehensive tools we have to study climate change and develop climate projections. However, the computational infrastructure required and the cost incurred in running such ESMs precludes direct use of such models in conjunction with a wide variety of tools that can further our understanding of climate. Here we are referring to tools that range from dynamical systems tools that give insight into underlying flow structure and topology to tools that come from various applied mathematical and statistical techniques and are central to quantifying stability, sensitivity, uncertainty and predictability to machine learning tools that are now being rapidly developed or improved. Our approach to facilitate the use of such models is to analyze output of ESM experiments (cf. CMIP) using a range of simpler models that consider integral balances of important quantities such as mass and/or energy in a Bayesian framework.We highlight the use of this approach in the context of the uptake of heat by the world oceans in the ongoing global warming. Indeed, since in excess of 90% of the anomalous radiative forcing due greenhouse gas emissions is sequestered in the world oceans, the nature of ocean heat uptake crucially determines the surface warming that is realized (cf. climate sensitivity). Nevertheless, ESMs themselves are never run long enough to directly assess climate sensitivity. So, we consider a range of models based on integral balances--balances that have to be realized in all first-principles based models of the climate system including the most detailed state-of-the art climate simulations. The models range from simple models of energy balance to those that consider dynamically important ocean processes such as the conveyor-belt circulation (Meridional Overturning Circulation, MOC), North Atlantic Deep Water (NADW) formation, Antarctic Circumpolar Current (ACC) and eddy mixing. Results from Bayesian analysis of such models using both ESM experiments and actual observations are presented. One such result points to the importance of direct sequestration of heat below 700 m, a process that is not allowed for in the simple models that have been traditionally used to deduce climate sensitivity.

Balance between apical membrane growth and luminal matrix resistance determines epithelial tubule shape.

PubMed

Dong, Bo; Hannezo, Edouard; Hayashi, Shigeo

2014-05-22

The morphological stability of biological tubes is crucial for the efficient circulation of fluids and gases. Failure of this stability causes irregularly shaped tubes found in multiple pathological conditions. Here, we report that Drosophila mutants of the ESCRT III component Shrub/Vps32 exhibit a strikingly elongated sinusoidal tube phenotype. This is caused by excessive apical membrane synthesis accompanied by the ectopic accumulation and overactivation of Crumbs in swollen endosomes. Furthermore, we demonstrate that the apical extracellular matrix (aECM) of the tracheal tube is a viscoelastic material coupled with the apical membrane. We present a simple mechanical model in which aECM elasticity, apical membrane growth, and their interaction are three vital parameters determining the stability of biological tubes. Our findings demonstrate a mechanical role for the extracellular matrix and suggest that the interaction of the apical membrane and an elastic aECM determines the final morphology of biological tubes independent of cell shape. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

The Self-sustained High temperature Synthesis (SHS) technology as novel approach in the management of asbestos waste.

PubMed

Gaggero, Laura; Ferretti, Maurizio

2018-06-15

The SHS technique was experimented in chrysotile breakdown. By means of two reactions such as Mg 3 Si 2 O 5 (OH) 4  + Fe 2 O 3  + 3 Mg and 2Mg 3 Si 2 O 5 (OH) 4  + Fe 3 O 4  + 4 Mg the chrysotile was completely converted into forsterite-rich olivine. Different mixtures of hematite + Mg and magnetite + Mg were tested with chrysotile to establish the maximum chrysotile amount in order to allow the reaction. In comparison with conventional thermal treatments, the SHS process is characterized by a fast reaction, needs low activation energy and the apparatus is simple. For these reasons, the asbestos neutralisation is carried out with positive balance of time and costs of the process. Furthermore, the combustion product can be re-used as secondary material. Copyright © 2017 Elsevier Ltd. All rights reserved.

Translating Research into Clinical Scale Manufacturing of Mesenchymal Stromal Cells

PubMed Central

Bieback, Karen; Kinzebach, Sven; Karagianni, Marianna

2010-01-01

It sounds simple to obtain sufficient numbers of cells derived from fetal or adult human tissues, isolate and/or expand the stem cells, and then transplant an appropriate number of these cells into the patient at the correct location. However, translating basic research into routine therapies is a complex multistep process which necessitates product regulation. The challenge relates to managing the expected therapeutic benefits with the potential risks and to balance the fast move to clinical trials with time-consuming cautious risk assessment. This paper will focus on the definition of mesenchymal stromal cells (MSCs), and challenges and achievements in the manufacturing process enabling their use in clinical studies. It will allude to different cellular sources, special capacities of MSCs, but also to current regulations, with a special focus on accessory material of human or animal origin, like media supplements. As cellular integrity and purity, formulation and lot release testing of the final product, validation of all procedures, and quality assurance are of utmost necessity, these topics will be addressed. PMID:21318154

A simple inertial model for Neptune's zonal circulation

NASA Technical Reports Server (NTRS)

Allison, Michael; Lumetta, James T.

1990-01-01

Voyager imaging observations of zonal cloud-tracked winds on Neptune revealed a strongly subrotational equatorial jet with a speed approaching 500 m/s and generally decreasing retrograde motion toward the poles. The wind data are interpreted with a speculative but revealingly simple model based on steady gradient flow balance and an assumed global homogenization of potential vorticity for shallow layer motion. The prescribed model flow profile relates the equatorial velocity to the mid-latitude shear, in reasonable agreement with the available data, and implies a global horizontal deformation scale L(D) of about 3000 km.

The Wang Landau parallel algorithm for the simple grids. Optimizing OpenMPI parallel implementation

NASA Astrophysics Data System (ADS)

Kussainov, A. S.

2017-12-01

The Wang Landau Monte Carlo algorithm to calculate density of states for the different simple spin lattices was implemented. The energy space was split between the individual threads and balanced according to the expected runtime for the individual processes. Custom spin clustering mechanism, necessary for overcoming of the critical slowdown in the certain energy subspaces, was devised. Stable reconstruction of the density of states was of primary importance. Some data post-processing techniques were involved to produce the expected smooth density of states.

SIMPLE MODEL OF ICE SEGREGATION USING AN ANALYTIC FUNCTION TO MODEL HEAT AND SOIL-WATER FLOW.

USGS Publications Warehouse

Hromadka, T.V.; Guymon, G.L.

1984-01-01

This paper reports on the development of a simple two-dimensional model of coupled heat and soil-water flow in freezing or thawing soil. The model also estimates ice-segregation (frost-heave) evolution. Ice segregation in soil results from water drawn into a freezing zone by hydraulic gradients created by the freezing of soil-water. Thus, with a favorable balance between the rate of heat extraction and the rate of water transport to a freezing zone, segregated ice lenses may form.

A simple kinetic model of a Ne-H2 Penning-plasma laser

NASA Astrophysics Data System (ADS)

Petrov, G. M.; Stefanova, M. S.; Pramatarov, P. M.

1995-09-01

A simple kinetic model of the Ne-H2 Penning-Plasma Laser (PPL) (NeI 585.3 nm) is proposed. The negative glow of a hollow cathode discharge at intermediate pressures is considered as the active medium. The balance equations for the upper and lower laser levels, electrons, ions and electron energy are solved. The dependences of the laser gain on the discharge conditions (Ne and H2 partial pressures, discharge current) are calculated and measured. The calculated values are in a good agreement with the experimental data.

The construction and operation of a low-cost poultry waste digester.

PubMed

Steinsberger, S C; Shih, J C

1984-05-01

A simple and low-cost poultry waste digester (PWD) was constructed to treat the waste from 4000 caged laying hens on University Research Unit No. 2 at North Carolina State University. The system was built basically of a plastic lining with insulation, a heating system, a hot-water tank, and other metering equipment. It was operated at 50 degrees C and pH 7.5-8.0. The initiation of methane production was achieved using the indigenous microflora in the poultry waste. At an optimal loading rate (7.5 kg volatile solids/m(3) day), the PWD produced biogas (55% methane) at a rate of 4.0 m(3)/m(3) day. The PWD was biologically stable and able to tolerate temporary overloads and shutdowns. A higher loading rate failed to maintain a high gas production rate and caused drops in methane content and pH value. Under optimal conditions, a positive energy balance was demonstrated with a net surplus of 50.6% of the gross energy. For methane production, the PWD system was proved to be technically feasible. The simple design and inexpensive materials used for this model could significantly reduce the cost of digestion compared to more conventional systems. More studies are needed to determine the durability, the required maintenance of the system, and the most economical method of biogas and solid residue utilization.

Multi-Mode Analysis of Dual Ridged Waveguide Systems for Material Characterization

DTIC Science & Technology

2015-09-17

characterization is the process of determining the dielectric, magnetic, and magnetoelectric properties of a material. For simple (i.e., linear ...field expressions in terms of elementary functions (sines, cosines, exponentials and Bessel functions) and corresponding propagation constants of the...with material parameters 0 and µ0. • The MUT is simple ( linear , isotropic, homogeneous), and the sample has a uniform thickness. • The waveguide

A Simple Model of Nitrogen Concentration, Throughput, and Denitrification in Estuaries

EPA Science Inventory

The Estuary Nitrogen Model (ENM) is a mass balance model that includes calculation of nitrogen losses within bays and estuaries using system flushing time. The model has been used to demonstrate the dependence of throughput and denitrification of nitrogen in bays and estuaries on...

Internet-based home training is capable to improve balance in multiple sclerosis: a randomized controlled trial.

PubMed

Frevel, D; Mäurer, M

2015-02-01

Balance disorders are common in multiple sclerosis. Aim of the study is to investigate the effectiveness of an Internet-based home training program (e-Training) to improve balance in patients with multiple sclerosis. A randomized, controlled study. Academic teaching hospital in cooperation with the therapeutic riding center Gut Üttingshof, Bad Mergentheim. Eighteen multiple sclerosis patients (mean EDSS 3,5) took part in the trial. Outcome of patients using e-Training (N.=9) was compared to the outcome of patients receiving hippotherapy (N.=9), which can be considered as an advanced concept for the improvement of balance and postural control in multiple sclerosis. After simple random allocation patients received hippotherapy or Internet-based home training (balance, postural control and strength training) twice a week for 12 weeks. Assessments were done before and after the intervention and included static and dynamic balance (primary outcome). Isometric muscle strength of the knee and trunk extension/flexion (dynamometer), walking capacity, fatigue and quality of life served as secondary outcome parameters. Both intervention groups showed comparable and highly significant improvement in static and dynamic balance capacity, no difference was seen between the both intervention groups. However looking at fatigue and quality of life only the group receiving hippotherapy improved significantly. Since e-Training shows even comparable effects to hippotherapy to improve balance, we believe that the established Internet-based home training program, specialized on balance and postural control training, is feasible for a balance and strength training in persons with multiple sclerosis. We demonstrated that Internet-based home training is possible in patients with multiple sclerosis.

Compact forced simple-shear sample for studying shear localization in materials

DOE PAGES

Gray, George Thompson; Vecchio, K. S.; Livescu, Veronica

2015-11-06

In this paper, a new specimen geometry, the compact forced-simple-shear specimen (CFSS), has been developed as a means to achieve simple shear testing of materials over a range of temperatures and strain rates. The stress and strain state in the gage section is designed to produce essentially “pure” simple shear, mode II in-plane shear, in a compact-sample geometry. The 2-D plane of shear can be directly aligned along specified directional aspects of a material's microstructure of interest; i.e., systematic shear loading parallel, at 45°, and orthogonal to anisotropic microstructural features in a material such as the pancake-shaped grains typical inmore » many rolled structural metals, or to specified directions in fiber-reinforced composites. Finally, the shear-stress shear-strain response and the damage evolution parallel and orthogonal to the pancake grain morphology in 7039-Al are shown to vary significantly as a function of orientation to the microstructure.« less

Balanced mechanical resonator for powder handling device

NASA Technical Reports Server (NTRS)

Sarrazin, Philippe C. (Inventor); Brunner, Will M. (Inventor)

2012-01-01

A system incorporating a balanced mechanical resonator and a method for vibration of a sample composed of granular material to generate motion of a powder sample inside the sample holder for obtaining improved analysis statistics, without imparting vibration to the sample holder support.

Selection Metric for Photovoltaic Materials Screening Based on Detailed-Balance Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blank, Beatrix; Kirchartz, Thomas; Lany, Stephan

The success of recently discovered absorber materials for photovoltaic applications has been generating increasing interest in systematic materials screening over the last years. However, the key for a successful materials screening is a suitable selection metric that goes beyond the Shockley-Queisser theory that determines the thermodynamic efficiency limit of an absorber material solely by its band-gap energy. Here, we develop a selection metric to quantify the potential photovoltaic efficiency of a material. Our approach is compatible with detailed balance and applicable in computational and experimental materials screening. We use the complex refractive index to calculate radiative and nonradiative efficiency limitsmore » and the respective optimal thickness in the high mobility limit. We also compare our model to the widely applied selection metric by Yu and Zunger [Phys. Rev. Lett. 108, 068701 (2012)] with respect to their dependence on thickness, internal luminescence quantum efficiency, and refractive index. Finally, the model is applied to complex refractive indices calculated via electronic structure theory.« less

Selection Metric for Photovoltaic Materials Screening Based on Detailed-Balance Analysis

DOE PAGES

Blank, Beatrix; Kirchartz, Thomas; Lany, Stephan; ...

2017-08-31

The success of recently discovered absorber materials for photovoltaic applications has been generating increasing interest in systematic materials screening over the last years. However, the key for a successful materials screening is a suitable selection metric that goes beyond the Shockley-Queisser theory that determines the thermodynamic efficiency limit of an absorber material solely by its band-gap energy. Here, we develop a selection metric to quantify the potential photovoltaic efficiency of a material. Our approach is compatible with detailed balance and applicable in computational and experimental materials screening. We use the complex refractive index to calculate radiative and nonradiative efficiency limitsmore » and the respective optimal thickness in the high mobility limit. We also compare our model to the widely applied selection metric by Yu and Zunger [Phys. Rev. Lett. 108, 068701 (2012)] with respect to their dependence on thickness, internal luminescence quantum efficiency, and refractive index. Finally, the model is applied to complex refractive indices calculated via electronic structure theory.« less

Research on regulating technique of material flow for 2-person and 30-day integrated CELSS test

NASA Astrophysics Data System (ADS)

Guo, Shuangsheng; Dong, Wenping; Ai, Weidang; Feng, Hongqi; Tang, Yongkang; Huang, Zhide; Shen, Yunze; Ren, Jin; Qin, Lifeng; Zeng, Gu; Zhang, Lihong; Zhu, Jingtao; Fei, Jinxue; Xu, Guoxin

2014-07-01

A man-plant integration test was processed using the CELSS integration experiment platform in which 4 kinds of plants were grown (Lactuca sativa L var. Dasusheng, L. sativa L var. Youmaicai, Gynura bicolor and Cichorium endivia L) to exchange material with 2 persons in order to research the dynamic changing laws and balanced regulation of air and water between man and plant in an inclosed system. In the test the material flow was measured so that the dynamically changing laws and balanced regulation of air and water between man and plant in the closed system were mostly mastered. The material closure degree of air, water and food reached 100%, 90% and 13.9% respectively with the whole system closure degree up to 95.1%. Meanwhile, it was proved that a 13.5 m2 planting area could meet the demand of one person for O2 in the system, and the energy efficiency ratio of which reached 59.56 g/(kW m2 day). The material flow dynamic balance-regulating technology was initially mastered between man and plant through the test. The interaction was realized among man, plant and environment in the closed system, which is of great significance to the advancement of long-term manned environment control and life support technology for China.

URINE SOURCE SEPARATION AND TREATMENT: NUTRIENT RECOVERY USING LOW-COST MATERIALS

EPA Science Inventory

Successful completion of this P3 Project will achieve the following expected outputs: identification of low-cost materials that can effectively recover ammonium, phosphate, and potassium from urine; material balance calculations for different urine separation and treatment scheme...

A homogenized localizing gradient damage model with micro inertia effect

NASA Astrophysics Data System (ADS)

Wang, Zhao; Poh, Leong Hien

2018-07-01

The conventional gradient enhancement regularizes structural responses during material failure. However, it induces a spurious damage growth phenomenon, which is shown here to persist in dynamics. Similar issues were reported with the integral averaging approach. Consequently, the conventional nonlocal enhancement cannot adequately describe the dynamic fracture of quasi-brittle materials, particularly in the high strain rate regime, where a diffused damage profile precludes the development of closely spaced macrocracks. To this end, a homogenization theory is proposed to translate the micro processes onto the macro scale. Starting with simple elementary models at the micro scale to describe the fracture mechanisms, an additional kinematic field is introduced to capture the variations in deformation and velocity within a unit cell. An energetic equivalence between micro and macro is next imposed to ensure consistency at the two scales. The ensuing homogenized microforce balance resembles closely the conventional gradient expression, albeit with an interaction domain that decreases with damage, complemented by a micro inertia effect. Considering a direct single pressure bar example, the homogenized model is shown to resolve the non-physical responses obtained with conventional nonlocal enhancement. The predictive capability of the homogenized model is furthermore demonstrated by considering the spall tests of concrete, with good predictions on failure characteristics such as fragmentation profiles and dynamic tensile strengths, at three different loading rates.

An amorphous silicon photodiode with 2 THz gain-bandwidth product based on cycling excitation process

NASA Astrophysics Data System (ADS)

Yan, Lujiang; Yu, Yugang; Zhang, Alex Ce; Hall, David; Niaz, Iftikhar Ahmad; Raihan Miah, Mohammad Abu; Liu, Yu-Hsin; Lo, Yu-Hwa

2017-09-01

Since impact ionization was observed in semiconductors over half a century ago, avalanche photodiodes (APDs) using impact ionization in a fashion of chain reaction have been the most sensitive semiconductor photodetectors. However, APDs have relatively high excess noise, a limited gain-bandwidth product, and high operation voltage, presenting a need for alternative signal amplification mechanisms of superior properties. As an amplification mechanism, the cycling excitation process (CEP) was recently reported in a silicon p-n junction with subtle control and balance of the impurity levels and profiles. Realizing that CEP effect depends on Auger excitation involving localized states, we made the counter intuitive hypothesis that disordered materials, such as amorphous silicon, with their abundant localized states, can produce strong CEP effects with high gain and speed at low noise, despite their extremely low mobility and large number of defects. Here, we demonstrate an amorphous silicon low noise photodiode with gain-bandwidth product of over 2 THz, based on a very simple structure. This work will impact a wide range of applications involving optical detection because amorphous silicon, as the primary gain medium, is a low-cost, easy-to-process material that can be formed on many kinds of rigid or flexible substrates.

Uncertainty in Estimates of Net Seasonal Snow Accumulation on Glaciers from In Situ Measurements

NASA Astrophysics Data System (ADS)

Pulwicki, A.; Flowers, G. E.; Radic, V.

2017-12-01

Accurately estimating the net seasonal snow accumulation (or "winter balance") on glaciers is central to assessing glacier health and predicting glacier runoff. However, measuring and modeling snow distribution is inherently difficult in mountainous terrain, resulting in high uncertainties in estimates of winter balance. Our work focuses on uncertainty attribution within the process of converting direct measurements of snow depth and density to estimates of winter balance. We collected more than 9000 direct measurements of snow depth across three glaciers in the St. Elias Mountains, Yukon, Canada in May 2016. Linear regression (LR) and simple kriging (SK), combined with cross correlation and Bayesian model averaging, are used to interpolate estimates of snow water equivalent (SWE) from snow depth and density measurements. Snow distribution patterns are found to differ considerably between glaciers, highlighting strong inter- and intra-basin variability. Elevation is found to be the dominant control of the spatial distribution of SWE, but the relationship varies considerably between glaciers. A simple parameterization of wind redistribution is also a small but statistically significant predictor of SWE. The SWE estimated for one study glacier has a short range parameter (90 m) and both LR and SK estimate a winter balance of 0.6 m w.e. but are poor predictors of SWE at measurement locations. The other two glaciers have longer SWE range parameters ( 450 m) and due to differences in extrapolation, SK estimates are more than 0.1 m w.e. (up to 40%) lower than LR estimates. By using a Monte Carlo method to quantify the effects of various sources of uncertainty, we find that the interpolation of estimated values of SWE is a larger source of uncertainty than the assignment of snow density or than the representation of the SWE value within a terrain model grid cell. For our study glaciers, the total winter balance uncertainty ranges from 0.03 (8%) to 0.15 (54%) m w.e. depending primarily on the interpolation method. Despite the challenges associated with accurately and precisely estimating winter balance, our results are consistent with the previously reported regional accumulation gradient.

Audiovisual Fundamentals; Basic Equipment Operation and Simple Materials Production.

ERIC Educational Resources Information Center

Bullard, John R.; Mether, Calvin E.

A guide illustrated with simple sketches explains the functions and step-by-step uses of audiovisual (AV) equipment. Principles of projection, audio, AV equipment, lettering, limited-quantity and quantity duplication, and materials preservation are outlined. Apparatus discussed include overhead, opaque, slide-filmstrip, and multiple-loading slide…

Tradeoffs in the Design of Health Plan Payment Systems: Fit, Power and Balance

PubMed Central

Geruso, Michael; McGuire, Thomas G.

2016-01-01

In many markets, including the new U.S. Marketplaces, health insurance plans are paid by risk-adjusted capitation, sometimes combined with reinsurance and other payment mechanisms. This paper proposes a framework for evaluating the de facto insurer incentives embedded in these complex payment systems. We discuss fit, power and balance, each of which addresses a distinct market failure in health insurance. We implement empirical metrics of fit, power, and balance in a study of Marketplace payment systems. Using data similar to that used to develop the Marketplace risk adjustment scheme, we quantify tradeoffs among the three classes of incentives. We show that an essential tradeoff arises between the goals of limiting costs and limiting cream skimming because risk adjustment, which is aimed at discouraging cream-skimming, weakens cost control incentives in practice. A simple reinsurance system scores better on our measures of fit, power and balance than the risk adjustment scheme in use in the Marketplaces. PMID:26922122

Tradeoffs in the design of health plan payment systems: Fit, power and balance.

PubMed

Geruso, Michael; McGuire, Thomas G

2016-05-01

In many markets, including the new U.S. Marketplaces, health insurance plans are paid by risk-adjusted capitation, sometimes combined with reinsurance and other payment mechanisms. This paper proposes a framework for evaluating the de facto insurer incentives embedded in these complex payment systems. We discuss fit, power and balance, each of which addresses a distinct market failure in health insurance. We implement empirical metrics of fit, power, and balance in a study of Marketplace payment systems. Using data similar to that used to develop the Marketplace risk adjustment scheme, we quantify tradeoffs among the three classes of incentives. We show that an essential tradeoff arises between the goals of limiting costs and limiting cream skimming because risk adjustment, which is aimed at discouraging cream-skimming, weakens cost control incentives in practice. A simple reinsurance system scores better on our measures of fit, power and balance than the risk adjustment scheme in use in the Marketplaces. Copyright © 2016 Elsevier B.V. All rights reserved.

Assisting people with disabilities to actively improve their collaborative physical activities with Nintendo Wii Balance Boards by controlling environmental stimulation.

PubMed

Shih, Ching-Hsiang; Chen, Ling-Che; Shih, Ching-Tien

2012-01-01

The latest researches have adopted software technology to modify the Nintendo Wii Balance Board functionality and used it to enable two people with developmental disabilities to actively perform physical activities. This study extended the latest research of the Wii Balance Board application to assess whether four people (two groups) with developmental disabilities would be able to actively improve their physical activities collaboration--walking to the designated location following simple instructions, by controlling their favorite environmental stimulation through using three Nintendo Wii Balance Boards. We employed an A-B-A-B design, with A represented the baseline and B represented intervention phases. Data showed that both groups of participants significantly increased their collaborative target response (collaboratively performing designated physical activities) by activating the control system to produce their preferred environmental stimulation during the intervention phases. Practical and developmental implications of the findings are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

Voluntary food intake during prolonged exercise in obese women.

PubMed

Woo, R; Garrow, J S; Pi-Sunyer, F X

1982-09-01

The effect of 57 days of moderate physical activity on the energy intake and balance of three obese women (187% of ideal weight) was investigated in a metabolic balance study. Food was offered in extra quantity, prepared in a palatable but simple fashion, and intake was covertly monitored. Expenditure was measured using the factorial method and indirect calorimetry done every 3 to 4 days. After a 5-day evaluation phase which no exercise was done, individual treadmill assignments were given to subjects to increase daily expenditure to 125% of sedentary levels. Mean dialy intake (1903 kcal/day) and expenditure (2882 kcal/day) did not change with time. As a result, negative energy balance was obtained and sustained. A consistent rate of weight loss (0.12 kg/day) at a reasonable cost (8200 kcal/kg)occurred. Therefore, obese women doing long-term moderate exercise do not compensate by an increase in caloric intake. This can produce a negative caloric balance when exercise is coupled with ad libitum selection of ordinary foods.

Community-based Adapted Tango Dancing for Individuals with Parkinson's Disease and Older Adults

PubMed Central

Hackney, Madeleine E.; McKee, Kathleen

2014-01-01

Adapted tango dancing improves mobility and balance in older adults and additional populations with balance impairments. It is composed of very simple step elements. Adapted tango involves movement initiation and cessation, multi-directional perturbations, varied speeds and rhythms. Focus on foot placement, whole body coordination, and attention to partner, path of movement, and aesthetics likely underlie adapted tango’s demonstrated efficacy for improving mobility and balance. In this paper, we describe the methodology to disseminate the adapted tango teaching methods to dance instructor trainees and to implement the adapted tango by the trainees in the community for older adults and individuals with Parkinson’s Disease (PD). Efficacy in improving mobility (measured with the Timed Up and Go, Tandem stance, Berg Balance Scale, Gait Speed and 30 sec chair stand), safety and fidelity of the program is maximized through targeted instructor and volunteer training and a structured detailed syllabus outlining class practices and progression. PMID:25548831

Effect of low-cost resistance training on lower-limb strength and balance in institutionalized seniors.

PubMed

Motalebi, Seyedeh Ameneh; Cheong, Loke Seng; Iranagh, Jamileh Amirzadeh; Mohammadi, Fatemeh

2018-01-01

Background/Study Context: Given the rapid increase in the aging population worldwide, fall prevention is of utmost importance. It is essential to establish an efficient, simple, safe, and low-cost intervention method for reducing the risk of falls. This study examined the effect of 12 weeks of progressive elastic resistance training on lower-limb muscle strength and balance in seniors living in the Rumah Seri Kenangan, social welfare home in Cheras, Malaysia. A total of 51 subjects qualified to take part in this quasi-experimental study. They were assigned to either the resistance exercise group (n = 26) or control group (n = 25). The mean age of the 45 participants who completed the program was 70.7 (SD = 6.6). The exercise group met twice per week and performing one to three sets of 8 to 10 repetitions for each of nine lower-limb elastic resistance exercises. All exercises were conducted at low to moderate intensities in sitting or standing positions. The subjects were tested at baseline and 6 and 12 weeks into the program. The results showed statistically significant improvements in lower-limb muscle strength as measured by five times sit-to-stand test (%Δ = 22.6) and dynamic balance quantified by the timed up-and-go test (%Δ = 18.7), four-square step test (%Δ = 14.67), and step test for the right (%Δ = 18.36) and left (%Δ = 18.80) legs. No significant changes were observed in static balance as measured using the tandem stand test (%Δ = 3.25), and one-leg stand test with eyes opened (%Δ = 9.58) and eyes closed (%Δ = -0.61) after completion of the program. The findings support the feasibility and efficacy of a simple and inexpensive resistance training program to improve lower-limb muscle strength and dynamic balance among the institutionalized older adults.

Stability of strongly nonlinear normal modes

NASA Astrophysics Data System (ADS)

Recktenwald, Geoffrey; Rand, Richard

2007-10-01

It is shown that a transformation of time can allow the periodic solution of a strongly nonlinear oscillator to be written as a simple cosine function. This enables the stability of strongly nonlinear normal modes in multidegree of freedom systems to be investigated by standard procedures such as harmonic balance.

SPATIALLY-BALANCED SAMPLING OF NATURAL RESOURCES IN THE PRESENCE OF FRAME IMPERFECTIONS

EPA Science Inventory

The spatial distribution of a natural resource is an important consideration in designing an efficient survey or monitoring program for the resource. Generally, samples that are more or less evenly dispersed over the extent of the resource will be more efficient than simple rando...

Action Research Methods: Plain and Simple

ERIC Educational Resources Information Center

Klein, Sheri R., Ed.

2012-01-01

Among the plethora of action research books on the market, there is no one text exclusively devoted to understanding how to acquire and interpret research data. Action Research Methods provides a balanced overview of the quantitative and qualitative methodologies and methods for conducting action research within a variety of educational…

A thermal-based remote sensing modeling system for estimating evapotranspiration from field to global scales

USDA-ARS?s Scientific Manuscript database

Thermal-infrared remote sensing of land surface temperature provides valuable information for quantifying root-zone water availability, evapotranspiration (ET) and crop condition. This paper describes a robust but relatively simple thermal-based energy balance model that parameterizes the key soil/s...

EVALUATION OF VAPOR EQUILIBRATION AND IMPACT OF PURGE VOLUME ON SOIL-GAS SAMPLING RESULTS

EPA Science Inventory

Sequential sampling was utilized at the Raymark Superfund site to evaluate attainment of vapor equilibration and the impact of purge volume on soil-gas sample results. A simple mass-balance equation indicates that removal of three to five internal volumes of a sample system shou...

Evaluation of the reliability and validity for X16 balance testing scale for the elderly.

PubMed

Ju, Jingjuan; Jiang, Yu; Zhou, Peng; Li, Lin; Ye, Xiaolei; Wu, Hongmei; Shen, Bin; Zhang, Jialei; He, Xiaoding; Niu, Chunjin; Xia, Qinghua

2018-05-10

Balance performance is considered as an indicator of functional status in the elderly, a large scale population screening and evaluation in the community context followed by proper interventions would be of great significance at public health level. However, there has been no suitable balance testing scale available for large scale studies in the unique community context of urban China. A balance scale named X16 balance testing scale was developed, which was composed of 3 domains and 16 items. A total of 1985 functionally independent and active community-dwelling elderly adults' balance abilities were tested using the X16 scale. The internal consistency, split-half reliability, content validity, construct validity, discriminant validity of X16 balance testing scale were evaluated. Factor analysis was performed to identify alternative factor structure. The Eigenvalues of factors 1, 2, and 3 were 8.53, 1.79, and 1.21, respectively, and their cumulative contribution to the total variance reached 72.0%. These 3 factors mainly represented domains static balance, postural stability, and dynamic balance. The Cronbach alpha coefficient for the scale was 0.933. The Spearman correlation coefficients between items and its corresponding domains were ranged from 0.538 to 0.964. The correlation coefficients between each item and its corresponding domain were higher than the coefficients between this item and other domains. With the increase of age, the scores of balance performance, domains static balance, postural stability, and dynamic balance in the elderly declined gradually (P < 0.001). With the increase of age, the proportion of the elderly with intact balance performance decreased gradually (P < 0.001). The reliability and validity of the X16 balance testing scale is both adequate and acceptable. Due to its simple and quick use features, it is practical to be used repeatedly and routinely especially in community setting and on large scale screening.

Flexible polymeric rib waveguide with self-align couplers system

PubMed Central

Huang, Cheng-Sheng; Wang, Wei-Chih

2011-01-01

The authors report a polymeric based rib waveguide with U shape self-align fiber couplers system using a simple micromolding process with SU8 as a molding material and polydimethysiloxane as a waveguide material. The material is used for its good optical transparency, low surface tension, biocompatibility, and durability. Furthermore, the material is highly formable. This unique fabrication molding technique provides a means of keeping the material and manufacturing costs to a minimum. The self-align fiber couplers system also proves a fast and simple means of light coupling. The flexible nature of the waveguide material makes this process ideal for a potential wearable optical sensor. PMID:22171151

10 CFR 75.10 - Facility information.

Code of Federal Regulations, 2010 CFR

2010-01-01

... features of the facility relating to material accounting, containment, and surveillance; (4) A description of the existing and proposed procedures at the facility for nuclear material accounting and control, with special reference to material balance areas established by the licensee, measurement of flow, and...

Relational Database Design of a Shipboard Ammunition Inventory, Requisitioning, and Reporting System

DTIC Science & Technology

1990-06-01

history of transactions effecting the status or quantity of that NI1N. Information on the current inventory balance is obtained from this section of...Number * Julian Date of Transaction * Activity Classification Code (ACC) * NALC * N1IN * Condition Code * Beginning Balance * Serial Number (if applicable...Ending Balance * Remarks As with the inventory information, ATR format varies with the type of control (Material Condition Code) applicable to that

Do planetary seasons play a role in attaining stable climates?

NASA Astrophysics Data System (ADS)

Olsen, Kasper Wibeck; Bohr, Jakob

2018-05-01

A simple phenomenological account for planetary climate instabilities is presented. The description is based on the standard model where the balance of incoming stellar radiation and outward thermal radiation is described by the effective planet temperature. Often, it is found to have three different points, or temperatures, where the influx of radiation is balanced with the out-flux, even with conserved boundary conditions. Two of these points are relatively long-term stable, namely the point corresponding to a cold climate and the point corresponding to a hot climate. In a classical sense these points are equilibrium balance points. The hypothesis promoted in this paper is the possibility that the intermediate third point can become long-term stable by being driven dynamically. The initially unstable point is made relatively stable over a long period by the presence of seasonal climate variations.

Spacecraft Charging Current Balance Model Applied to High Voltage Solar Array Operations

NASA Technical Reports Server (NTRS)

Willis, Emily M.; Pour, Maria Z. A.

2016-01-01

Spacecraft charging induced by high voltage solar arrays can result in power losses and degradation of spacecraft surfaces. In some cases, it can even present safety issues for astronauts performing extravehicular activities. An understanding of the dominant processes contributing to spacecraft charging induced by solar arrays is important to current space missions, such as the International Space Station, and to any future space missions that may employ high voltage solar arrays. A common method of analyzing the factors contributing to spacecraft charging is the current balance model. Current balance models are based on the simple idea that the spacecraft will float to a potential such that the current collecting to the surfaces equals the current lost from the surfaces. However, when solar arrays are involved, these currents are dependent on so many factors that the equation becomes quite complicated. In order for a current balance model to be applied to solar array operations, it must incorporate the time dependent nature of the charging of dielectric surfaces in the vicinity of conductors1-3. This poster will present the factors which must be considered when developing a current balance model for high voltage solar array operations and will compare results of a current balance model with data from the Floating Potential Measurement Unit4 on board the International Space Station.

Humic First Theory: A New Theory on the Origin of Life

NASA Astrophysics Data System (ADS)

Daei, Mohammad Ali; Daei, Manijeh; Daei, Bijan

2017-04-01

In 1953, Miller & Urey through a brilliant experiment demonstrated that the building blocks of life could evolve in primitive earth conditions [1]. During the recent years scientists revealed that organic matters are not very rare compounds in comets, asteroids, and meteorites which have bombarded the ancient earth repeatedly [2]. So simple organic molecules on early earth could be quite enough to start chemical evolution and steadily, proceeded to the very simple form of life. Many theories have tried to explain how life emerged from non life, but failed, largely due to the lack of a distinct methodology. There is a huge gap between the simple building blocks, like amino acid, sugar, and lipid molecules, to a living cell with a very sophisticated structure and organization. It is unacceptable to fill this great distance, only by accidental reactions in a passive media (primitive soap) even, over a very long time. Obviously, manufacturing of a primitive cell required a natural factory with rather firm and resistant basement, plenty of organic and inorganic raw materials and qualified production line, plus some sources of energy. There were plenty of solar energy and water in the early Earth, but what about the other factors? Availability of essential minerals was not guaranteed at all, in primitive earth which covered with bare, dead rocks. While we are not able today, to multiply any microorganisms in ideal conditions of modern laboratory in the absence of only one of essential nutrients or elements, how can we expect primitive cells appear on early earth conditions without the support of soluble minerals and organic matters? Ideal production line must be active and protective, have catalyzing ability, could provide numerous opportunities for interaction between basic bio molecules (mainly RNA and proteins) and above all, have capability to react with different sources of energy. There are strong evidences that show only some form of stable, rich and active organic matter like modern "humic substances" could perform this great and complicated duty. A mass of warm, wet clay mixed with enough humic substances (HS) in suitable PH, could provide all above requirements, and promote biochemical evolution step by step toward a functional primitive cell. HS are fluorescent compounds and could transform UV radiation to usable light. In addition these protective materials could provide chemical energy plus balanced minerals and organic molecules. While everything in non living world is reducing energy, HS can collect more and more material and energy like a living organism. Fortunately, there are reliable evidences that HS could be accessible on ancient Earth. In fact Ziechman et al [7], in 1994 by finding humic material in Miller's experimental vessels proved that humic substances could be generated on early Earth conditions by polymerizing simple organic molecules. Our investigations show elemental selection and also chairal selection for life are proportionately tailored to Humic materials. For example nearly all heavy metals make insoluble compounds with HS, hence omitted from life processes. In contrast all essential elements have appropriate affinity and workability with HS. There is reliable evidence that shows HS prefer left amino acids and right sugars. As you see many signs and symptoms are referring to "humic substances" as the mother of life, at least on this planet.

Design and development of a novel balancer with variable difficulty for training and evaluation.

PubMed

Ang, W T; Tan, U-X; Tan, H G; Myo, T; Ng, C K; Koh, K L; Cheam, B S

2008-11-01

This paper presents a novel, portable and cost-effective balance trainer with the necessary important features to improve the reach of rehabilitation to the masses. There are three factors that contribute to a person's ability to maintain standing balance: Proprioceptive feedback (from the joints), vision, and the vestibular system. These systems can be affected by injury, infection, or brain damage caused by stroke. One example of such injuries is ankle injury. A large focus of the physiotherapy and sports medicine community is using postural-control tasks to prevent, assess and rehabilitate patients. Unfortunately, there are presently two extreme ends of balance training devices. On one end, there is high-end equipment which only large hospitals are capable of buying. On the other end are the simple balance boards which offer limited features. To develop the new balance trainer - the Pro.Balance - therapists at the Singapore General Hospital drafted a new 'wish list' of requirements. The prototype was built at the Nanyang Technological University, Singapore, and was commercialized by Lab Rehab Pte Ltd as the Pro.Balance. The device has a small footprint, incorporating only the most important and frequently used functions. These functions include being able to provide different levels of difficulty, setting different difficulties in different directions, the storing of a patient's performance, real-time visual feedback to aid the patient and different types of modes for different purposes. Springs are used to vary the amount of supporting moments, thus varying the difficulty levels. This paper describes the design and features of the Pro.Balance.

Evaluation of residual oil saturation after waterflood in a carbonate reservoir

DOE Office of Scientific and Technical Information (OSTI.GOV)

Verma, M.K.; Boucherit, M.; Bouvier, L.

Four different approaches, including special core analysis (SCAL), log-inject-log, thermal-decay-time (TDT) logs, and material balance, were used to narrow the range of residual oil saturation (ROS) after waterflood, S[sub orw], in a carbonate reservoir in Qatar to between 23% and 27%. An equation was developed that relates S[sub orw] with connate-water saturation, S[sub wi], and porosity. This paper presents the results of S[sub orw] determinations with four different techniques: core waterflood followed by centrifuging, log-inject-log, TDT logging, and material balance.

NASA LaRC Strain Gage Balance Design Concepts

NASA Technical Reports Server (NTRS)

Rhew, Ray D.

1999-01-01

The NASA Langley Research Center (LaRC) has been designing strain-gage balances for more than fifty years. These balances have been utilized in Langley's wind tunnels, which span over a wide variety of aerodynamic test regimes, as well as other ground based test facilities and in space flight applications. As a result, the designs encompass a large array of sizes, loads, and environmental effects. Currently Langley has more than 300 balances available for its researchers. This paper will focus on the design concepts for internal sting mounted strain-gage balances. However, these techniques can be applied to all force measurement design applications. Strain-gage balance concepts that have been developed over the years including material selection, sting, model interfaces, measuring, sections, fabrication, strain-gaging and calibration will be discussed.

An applicational process for dynamic balancing of turbomachinery shafting

NASA Technical Reports Server (NTRS)

Verhoff, Vincent G.

1990-01-01

The NASA Lewis Research Center has developed and implemented a time-efficient methodology for dynamically balancing turbomachinery shafting. This methodology minimizes costly facility downtime by using a balancing arbor (mandrel) that simulates the turbomachinery (rig) shafting. The need for precision dynamic balancing of turbomachinery shafting and for a dynamic balancing methodology is discussed in detail. Additionally, the inherent problems (and their causes and effects) associated with unbalanced turbomachinery shafting as a function of increasing shaft rotational speeds are discussed. Included are the design criteria concerning rotor weight differentials for rotors made of different materials that have similar parameters and shafting. The balancing methodology for applications where rotor replaceability is a requirement is also covered. This report is intended for use as a reference when designing, fabricating, and troubleshooting turbomachinery shafting.

Assessment of the Uniqueness of Wind Tunnel Strain-Gage Balance Load Predictions

NASA Technical Reports Server (NTRS)

Ulbrich, N.

2016-01-01

A new test was developed to assess the uniqueness of wind tunnel strain-gage balance load predictions that are obtained from regression models of calibration data. The test helps balance users to gain confidence in load predictions of non-traditional balance designs. It also makes it possible to better evaluate load predictions of traditional balances that are not used as originally intended. The test works for both the Iterative and Non-Iterative Methods that are used in the aerospace testing community for the prediction of balance loads. It is based on the hypothesis that the total number of independently applied balance load components must always match the total number of independently measured bridge outputs or bridge output combinations. This hypothesis is supported by a control volume analysis of the inputs and outputs of a strain-gage balance. It is concluded from the control volume analysis that the loads and bridge outputs of a balance calibration data set must separately be tested for linear independence because it cannot always be guaranteed that a linearly independent load component set will result in linearly independent bridge output measurements. Simple linear math models for the loads and bridge outputs in combination with the variance inflation factor are used to test for linear independence. A highly unique and reversible mapping between the applied load component set and the measured bridge output set is guaranteed to exist if the maximum variance inflation factor of both sets is less than the literature recommended threshold of five. Data from the calibration of a six{component force balance is used to illustrate the application of the new test to real-world data.

Self-folding and aggregation of amyloid nanofibrils

NASA Astrophysics Data System (ADS)

Paparcone, Raffaella; Cranford, Steven W.; Buehler, Markus J.

2011-04-01

Amyloids are highly organized protein filaments, rich in β-sheet secondary structures that self-assemble to form dense plaques in brain tissues affected by severe neurodegenerative disorders (e.g. Alzheimer's Disease). Identified as natural functional materials in bacteria, in addition to their remarkable mechanical properties, amyloids have also been proposed as a platform for novel biomaterials in nanotechnology applications including nanowires, liquid crystals, scaffolds and thin films. Despite recent progress in understanding amyloid structure and behavior, the latent self-assembly mechanism and the underlying adhesion forces that drive the aggregation process remain poorly understood. On the basis of previous full atomistic simulations, here we report a simple coarse-grain model to analyze the competition between adhesive forces and elastic deformation of amyloid fibrils. We use simple model system to investigate self-assembly mechanisms of fibrils, focused on the formation of self-folded nanorackets and nanorings, and thereby address a critical issue in linking the biochemical (Angstrom) to micrometre scales relevant for larger-scale states of functional amyloid materials. We investigate the effect of varying the interfibril adhesion energy on the structure and stability of self-folded nanorackets and nanorings and demonstrate that these aggregated amyloid fibrils are stable in such states even when the fibril-fibril interaction is relatively weak, given that the constituting amyloid fibril length exceeds a critical fibril length-scale of several hundred nanometres. We further present a simple approach to directly determine the interfibril adhesion strength from geometric measures. In addition to providing insight into the physics of aggregation of amyloid fibrils our model enables the analysis of large-scale amyloid plaques and presents a new method for the estimation and engineering of the adhesive forces responsible of the self-assembly process of amyloidnanostructures, filling a gap that previously existed between full atomistic simulations of primarily ultra-short fibrils and much larger micrometre-scale amyloid aggregates. Via direct simulation of large-scale amyloid aggregates consisting of hundreds of fibrils we demonstrate that the fibril length has a profound impact on their structure and mechanical properties, where the critical fibril length-scale derived from our analysis of self-folded nanorackets and nanorings defines the structure of amyloid aggregates. A multi-scale modeling approach as used here, bridging the scales from Angstroms to micrometres, opens a wide range of possible nanotechnology applications by presenting a holistic framework that balances mechanical properties of individual fibrils, hierarchical self-assembly, and the adhesive forces determining their stability to facilitate the design of de novoamyloid materials.

Sorption of Radionuclides to Building Materials and its Removal Using Simple Wash Solutions

EPA Pesticide Factsheets

Data corresponding to the figures in the paper.This dataset is associated with the following publication:Kaminski, M., C. Mertz, L. Ortega, and N. Kivenas. Sorption of Radionuclides to Building Materials and its Removal Using Simple Wash Solutions. Journal of Environmental Chemical Engineering. Elsevier B.V., Amsterdam, NETHERLANDS, ., (2016).

Monitored Natural Attenuation and Enhanced Attenuation for Chlorinated Solvent Plumes - It’s All About Balance

DOE Office of Scientific and Technical Information (OSTI.GOV)

VANGELAS, KAREN

2005-05-19

Nature's inherent ability to cleanse itself is at the heart of Monitored Natural Attenuation (MNA). The complexity comes when one attempts to measure and calculate this inherent ability, called the Natural Attenuation Capacity (NAC), and determine if it is sufficient to cleanse the system to agreed upon criteria. An approach that is simple in concept for determining whether the NAC is sufficient for MNA to work is the concept of a mass balance. Mass balance is a robust framework upon which all decisions can be made. The inflows to and outflows from the system are balanced against the NAC ofmore » the subsurface system. For MNA to be acceptable, the NAC is balanced against the contaminant loading to the subsurface system with the resulting outflow from the system being in a range that is acceptable to the regulating and decision-making parties. When the system is such that the resulting outflow is not within an acceptable range, the idea of taking actions that are sustainable and that will bring the system within the acceptable range of outflows is evaluated. These sustainable enhancements are being developed under the Enhanced Attenuation (EA) concept.« less

Load Balancing in Hypergraphs

NASA Astrophysics Data System (ADS)

Delgosha, Payam; Anantharam, Venkat

2018-03-01

Consider a simple locally finite hypergraph on a countable vertex set, where each edge represents one unit of load which should be distributed among the vertices defining the edge. An allocation of load is called balanced if load cannot be moved from a vertex to another that is carrying less load. We analyze the properties of balanced allocations of load. We extend the concept of balancedness from finite hypergraphs to their local weak limits in the sense of Benjamini and Schramm (Electron J Probab 6(23):13, 2001) and Aldous and Steele (in: Probability on discrete structures. Springer, Berlin, pp 1-72, 2004). To do this, we define a notion of unimodularity for hypergraphs which could be considered an extension of unimodularity in graphs. We give a variational formula for the balanced load distribution and, in particular, we characterize it in the special case of unimodular hypergraph Galton-Watson processes. Moreover, we prove the convergence of the maximum load under some conditions. Our work is an extension to hypergraphs of Anantharam and Salez (Ann Appl Probab 26(1):305-327, 2016), which considered load balancing in graphs, and is aimed at more comprehensively resolving conjectures of Hajek (IEEE Trans Inf Theory 36(6):1398-1414, 1990).

Recovery of dynamic balance after general anesthesia with sevoflurane in short-duration oral surgery.

PubMed

Fujisawa, Toshiaki; Miyamoto, Eriko; Takuma, Shigeru; Shibuya, Makiko; Kurozumi, Akihiro; Kimura, Yukifumi; Kamekura, Nobuhito; Fukushima, Kazuaki

2009-01-01

Recovery of dynamic balance, involving adjustment of the center of gravity, is essential for safe discharge on foot after ambulatory anesthesia. The purpose of this study was to assess the recovery of dynamic balance after general anesthesia with sevoflurane, using two computerized dynamic posturographies. Nine hospitalized patients undergoing oral surgery of less than 2 h duration under general anesthesia (air-oxygensevoflurane) were studied. A dynamic balance test, assessing the ability of postural control against unpredictable perturbation stimuli (Stability System; Biodex Medical), a walking analysis test using sheets with foot pressure sensors (Walk Way-MG1000; Anima), and two simple psychomotor function tests were performed before anesthesia (baseline), and 150 and 210 min after the emergence from anesthesia. Only the double-stance phase in the walking analysis test showed a significant difference between baseline and results at 150 min. None of the other variables showed any differences among results at baseline and at 150 and 210 min. The recovery times for dynamic balance and psychomotor function seem to be within 150 min after emergence from general anesthesia with sevoflurane in patients undergoing oral surgery of less than 2-h duration.

Poor anaerobic power/capability and static balance predicted prospective musculoskeletal injuries among Soldiers of the 101st Airborne (Air Assault) Division.

PubMed

Nagai, Takashi; Lovalekar, Mita; Wohleber, Meleesa F; Perlsweig, Katherine A; Wirt, Michael D; Beals, Kim

2017-11-01

Musculoskeletal injuries have negatively impacted tactical readiness. The identification of prospective and modifiable risk factors of preventable musculoskeletal injuries can guide specific injury prevention strategies for Soldiers and health care providers. To analyze physiological and neuromuscular characteristics as predictors of preventable musculoskeletal injuries. Prospective-cohort study. A total of 491 Soldiers were enrolled and participated in the baseline laboratory testing, including body composition, aerobic capacity, anaerobic power/capacity, muscular strength, flexibility, static balance, and landing biomechanics. After reviewing their medical charts, 275 male Soldiers who met the criteria were divided into two groups: with injuries (INJ) and no injuries (NOI). Simple and multiple logistic regression analyses were used to calculate the odds ratio (OR) and significant predictors of musculoskeletal injuries (p<0.05). The final multiple logistic regression model included the static balance with eyes-closed and peak anaerobic power as predictors of future injuries (p<0.001). The current results highlighted the importance of anaerobic power/capacity and static balance. High intensity training and balance exercise should be incorporated in their physical training as countermeasures. Copyright © 2017 Sports Medicine Australia. All rights reserved.

Monitored natural attenuation and enhanced attenuation for chlorinated solvent plumes - It's all about balance

USGS Publications Warehouse

Adams, K.A.; Vangelas, K.M.; Looney, B.B.; Chapelle, F.; Early, T.; Gilmore, T.; Sink, C.H.

2005-01-01

Nature's inherent ability to cleanse itself is at the heart of Monitored Natural Attenuation (MNA). The complexity comes when one attempts to measure and calculate this inherent ability, called the Natural Attenuation Capacity (NAC), and determine if it is sufficient to cleanse the system to agreed upon criteria. An approach that is simple in concept for determining whether the NAC is sufficient for MNA to work is the concept of a mass balance. Mass balance is a robust framework upon which all decisions can be made. The inflows to and outflows from the system are balanced against the NAC of the subsurface system. For MNA to be acceptable, the NAC is balanced against the contaminant loading to the subsurface system with the resulting outflow from the system being in a range that is acceptable to the regulating and decision-making parties. When the system is such that the resulting outflow is not within an acceptable range, the idea of taking actions that are sustainable and that will bring the system within the acceptable range of outflows is evaluated. These sustainable enhancements are being developed under the Enhanced Attenuation (EA) concept. Copyright ASCE 2005.

Fracture as a material sink

NASA Astrophysics Data System (ADS)

Volokh, K. Y.

2017-12-01

Cracks are created by massive breakage of molecular or atomic bonds. The latter, in its turn, leads to the highly localized loss of material, which is the reason why even closed cracks are visible by a naked eye. Thus, fracture can be interpreted as the local material sink. Mass conservation is violated locally in the area of material failure. We consider a theoretical formulation of the coupled mass and momenta balance equations for a description of fracture. Our focus is on brittle fracture and we propose a finite strain hyperelastic thermodynamic framework for the coupled mass-flow-elastic boundary value problem. The attractiveness of the proposed framework as compared to the traditional continuum damage theories is that no internal parameters (like damage variables, phase fields, etc.) are used while the regularization of the failure localization is provided by the physically sound law of mass balance.

A Simple Analytic Model for Estimating Mars Ascent Vehicle Mass and Performance

NASA Technical Reports Server (NTRS)

Woolley, Ryan C.

2014-01-01

The Mars Ascent Vehicle (MAV) is a crucial component in any sample return campaign. In this paper we present a universal model for a two-stage MAV along with the analytic equations and simple parametric relationships necessary to quickly estimate MAV mass and performance. Ascent trajectories can be modeled as two-burn transfers from the surface with appropriate loss estimations for finite burns, steering, and drag. Minimizing lift-off mass is achieved by balancing optimized staging and an optimized path-to-orbit. This model allows designers to quickly find optimized solutions and to see the effects of design choices.

[Intracranial pressure monitoring apparatus for clinical use balanced pressure sensors].

PubMed

Numoto, M

1976-04-01

Three types of pressure sensors, (1) electric pressure switch, (2) fiber optic pressure switch and (3) pressure indicating bag for intracranial pressure monitoring which were developed by the author are described. Advantages and disadvantages between them are also discussed. The electric pressure switch is relatively simple in construction but has a possibility of producing micro-shock hazard in case of accidental electric leakage. The fiber optic pressure switch is the safest for the micro shock but its structure is rather complicated and fragile. The pressure indicating bag is simple to make and durable to use. However, it has a hydrostatic effect.

Constitutive restrictions for deformable simple media that are heat conducting and electrically polarizable

NASA Astrophysics Data System (ADS)

Montanaro, Adriano

2017-07-01

We present the constitutive restrictions for a deformable simple medium that is heat conducting, electrically polarizable and interacting with the electric field, either of elastic type or with a fading memory. The used theory is an extension of the well known Green-Naghdi thermo-mechanical theories of continua, mainly devoted to thermoelastic bodies or rigid conductors. Hence the theory that is used here is based on an entropy balance law rather than an entropy imbalance, uses the notion of thermal displacement, and predicts heat propagation by thermal waves at finite speed.

Liquefaction of sub-bituminous coal

DOEpatents

Schindler, Harvey D.; Chen, James M.

1986-01-01

Sub-bituminous coal is directly liquefied in two stages by use of a liquefaction solvent containing insoluble material as well as 850.degree. F.+ material and 850.degree. F.- material derived from the second stage, and controlled temperature and conversion in the second stage. The process is in hydrogen balance.

Physical explanations of the destabilizing effect of damping in rotating parts

NASA Technical Reports Server (NTRS)

Crandall, S. H.

1980-01-01

The destabilizing effect of rotating damping was investigated. When the rotation was faster than the whirl, rotating damping drags the orbiting particle forward. When stationary damping was also present, the stability borderline was readily determined by balancing the backward and forward drags. A key notion was that a forward whirl at rate omega a sub n with respect to stationary axes appears to be a backward whirl at rate Omega - omega sub n with respect to a system rotating supercritically at rate Omega. The growth rate of unstable whirls (or the decay rate of stable whirls was readily estimated by a simple energy balance.

A stability theorem for energy-balance climate models

NASA Technical Reports Server (NTRS)

Cahalan, R. F.; North, G. R.

1979-01-01

The paper treats the stability of steady-state solutions of some simple, latitude-dependent, energy-balance climate models. For north-south symmetric solutions of models with an ice-cap-type albedo feedback, and for the sum of horizontal transport and infrared radiation given by a linear operator, it is possible to prove a 'slope stability' theorem, i.e., if the local slope of the steady-state iceline latitude versus solar constant curve is positive (negative) the steady-state solution is stable (unstable). Certain rather weak restrictions on the albedo function and on the heat transport are required for the proof, and their physical basis is discussed.

Energy-balance climate models

NASA Technical Reports Server (NTRS)

North, G. R.; Cahalan, R. F.; Coakley, J. A., Jr.

1980-01-01

An introductory survey of the global energy balance climate models is presented with an emphasis on analytical results. A sequence of increasingly complicated models involving ice cap and radiative feedback processes are solved and the solutions and parameter sensitivities are studied. The model parameterizations are examined critically in light of many current uncertainties. A simple seasonal model is used to study the effects of changes in orbital elements on the temperature field. A linear stability theorem and a complete nonlinear stability analysis for the models are developed. Analytical solutions are also obtained for the linearized models driven by stochastic forcing elements. In this context the relation between natural fluctuation statistics and climate sensitivity is stressed.

Energy balance climate models

NASA Technical Reports Server (NTRS)

North, G. R.; Cahalan, R. F.; Coakley, J. A., Jr.

1981-01-01

An introductory survey of the global energy balance climate models is presented with an emphasis on analytical results. A sequence of increasingly complicated models involving ice cap and radiative feedback processes are solved, and the solutions and parameter sensitivities are studied. The model parameterizations are examined critically in light of many current uncertainties. A simple seasonal model is used to study the effects of changes in orbital elements on the temperature field. A linear stability theorem and a complete nonlinear stability analysis for the models are developed. Analytical solutions are also obtained for the linearized models driven by stochastic forcing elements. In this context the relation between natural fluctuation statistics and climate sensitivity is stressed.

Improving Postural Control in the Battement Tendu: One Teacher's Reflections and Somatic Exercises

ERIC Educational Resources Information Center

Batson, Glenna

2010-01-01

The battement tendu is introduced early in dance training, remaining integral to a dancer's vocabulary. Although appearing relatively simple to execute, the tendu aesthetic takes years to master. One reason might be that efficient performance requires complex coordination of postural balance. Known as postural control, this coordination appears in…

Two-Wire to Four-Wire Audio Converter

NASA Technical Reports Server (NTRS)

Talley, G. L., Jr; Seale, B. L.

1983-01-01

Simple circuit provides interface between normally incompatible voicecommunication lines. Circuit maintains 40 dB of isolation between input and output halves of four-wire line permitting two-wire line to be connected. Balancing potentiometer, Rg, adjusts gain of IC2 to null feed through from input to output. Adjustment is done on workbench just after assembly.

Effective Management of Information Security and Privacy

ERIC Educational Resources Information Center

Anderson, Alicia

2006-01-01

No university seems immune to cyber attacks. For many universities, such events have served as wake-up calls to develop a comprehensive information security and privacy strategy. This is no simple task, however. It involves balancing a culture of openness with a need for security and privacy. Security and privacy are not the same, and the…

Physical Education Curriculum Priorities: Evidence for Education and Skillfulness

ERIC Educational Resources Information Center

Ennis, Catherine D.

2011-01-01

One question facing kinesiologists today is how to implement findings from research into society, in this case, physical education. In this paper I examine the role of a balanced approach to educational physical education in promoting physical activity. I argue that limiting physical education to simple tasks that encourage students to workout at…

Sharing the Earth, Kit II.

ERIC Educational Resources Information Center

1971

Introducing the pupil to the science of ecology is the purpose of Scholastic's Earth Corps Ecology/Conservation Study Kits for grades 3-6. Simple terms are used to show how all living things are inter-related to their environment, to demonstrate the intricate and delicate balance of nature, and to point out how man's interference with nature's…

Introducing Valuation Effects-Based External Balance Analysis into the Undergraduate Macroeconomics Curricula: A Simple Framework with Applications

ERIC Educational Resources Information Center

Brust, Peter; Jayakumar, Vivekanand

2012-01-01

Global imbalances and the sustainability of large U.S. current account deficits have dominated international macroeconomics of late. Pedagogically, a clear disconnect exists between graduate-level open-economy macroeconomics that emphasizes intertemporal current account models and net foreign asset adjustment featuring valuation effects, and,…

A Simple Water Balance Model Adapted for Arctic Hydrology Reveals Glacier and Streamflow Responses to Climate Change in the Copper River, Alaska

NASA Astrophysics Data System (ADS)

Valentin, M. M.; Hay, L.; Van Beusekom, A. E.; Viger, R. J.; Hogue, T. S.

2016-12-01

Forecasting the hydrologic response to climate change in Alaska's glaciated watersheds remains daunting for hydrologists due to sparse field data and few modeling tools, which frustrates efforts to manage and protect critical aquatic habitat. Approximately 20% of the 64,000 square kilometer Copper River watershed is glaciated, and its glacier-fed tributaries support renowned salmon fisheries that are economically, culturally, and nutritionally invaluable to the local communities. This study adapts a simple, yet powerful, conceptual hydrologic model to simulate changes in the timing and volume of streamflow in the Copper River, Alaska as glaciers change under plausible future climate scenarios. The USGS monthly water balance model (MWBM), a hydrologic tool used for two decades to evaluate a broad range of hydrologic questions in the contiguous U.S., was enhanced to include glacier melt simulations and remotely sensed data. In this presentation we summarize the technical details behind our MWBM adaptation and demonstrate its use in the Copper River Basin to evaluate glacier and streamflow responses to climate change.

Dynamic Characteristics of a Simple Brayton Cryocycle

NASA Astrophysics Data System (ADS)

Kutzschbach, A.; Kauschke, M.; Haberstroh, Ch.; Quack, H.

2006-04-01

The goal of the overall program is to develop a dynamic numerical model of helium refrigerators and the associated cooling systems based on commercial simulation software. The aim is to give system designers a tool to search for optimum control strategies during the construction phase of the refrigerator with the help of a plant "simulator". In a first step, a simple Brayton refrigerator has been investigated, which consists of a compressor, an after-cooler, a counter-current heat exchanger, a turboexpander and a heat source. Operating modes are "refrigeration" and "liquefaction". Whereas for the steady state design only component efficiencies are needed and mass and energy balances have to be calculated, for the dynamic calculation one needs also the thermal masses and the helium inventory. Transient mass and energy balances have to be formulated for many small elements and then solved simultaneously for all elements. Starting point of the simulation of the Brayton cycle is the steady state operation at design conditions. The response of the system to step and cyclic changes of the refrigeration or liquefaction rate are calculated and characterized.

Transcranial direct current stimulation (tDCS) to the supplementary motor area (SMA) influences performance on motor tasks.

PubMed

Hupfeld, K E; Ketcham, C J; Schneider, H D

2017-03-01

The supplementary motor area (SMA) is believed to be highly involved in the planning and execution of both simple and complex motor tasks. This study aimed to examine the role of the SMA in planning the movements required to complete reaction time, balance, and pegboard tasks using anodal transcranial direct current stimulation (tDCS), which passes a weak electrical current between two electrodes, in order to modulate neuronal activity. Twenty healthy adults were counterbalanced to receive either tDCS (experimental condition) or no tDCS (control condition) for 3 days. During administration of tDCS, participants performed a balance task significantly faster than controls. After tDCS, subjects significantly improved their simple and choice reaction time. These results demonstrate that the SMA is highly involved in planning and executing fine and gross motor skill tasks and that tDCS is an effective modality for increasing SMA-related performance on these tasks. The findings may be generalizable and therefore indicate implications for future interventions using tDCS as a therapeutic tool.

A Simple Ballistic Material Model for Soda-Lime Glass

DTIC Science & Technology

2009-01-01

Author’s personal copy A simple ballistic material model for soda-lime glass M. Grujicic a,*, B. Pandurangan a, N. Coutris a, B.A. Cheeseman b, C...Transparent armor Material modeling Ballistic performance Soda-lime glass a b s t r a c t Various open-literature experimental findings pertaining...notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not

Scintillator material

DOEpatents

Anderson, David F.; Kross, Brian J.

1994-01-01

An improved scintillator material comprising cerium fluoride is disclosed. Cerium fluoride has been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to known scintillator materials such as thallium-doped sodium iodide, barium fluoride and bismuth germanate. As a result, cerium fluoride is favorably suited for use as a scintillator material in positron emission tomography.

Scintillator material

DOEpatents

Anderson, David F.; Kross, Brian J.

1992-01-01

An improved scintillator material comprising cerium fluoride is disclosed. Cerium fluoride has been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to known scintillator materials such as thallium-doped sodium iodide, barium fluoride and bismuth germanate. As a result, cerium fluoride is favorably suited for use as a scintillator material in positron emission tomography.

Solution-Processable Balanced Ambipolar Field-Effect Transistors Based on Carbonyl-Regulated Copolymers.

PubMed

Yang, Chengdong; Fang, Renren; Yang, Xiongfa; Chen, Ru; Gao, Jianhua; Fan, Hanghong; Li, Hongxiang; Hu, Wenping

2018-04-04

It is very important to develop ambipolar field effect transistors to construct complementary circuits. To obtain balanced hole- and electron-transport properties, one of the key issues is to regulate the energy levels of the frontier orbitals of the semiconductor materials by structural tailoring, so that they match well with the electrode Fermi levels. Five conjugated copolymers were synthesized and exhibited low LUMO energy levels and narrow bandgaps on account of the strong electron-withdrawing effect of the carbonyl groups. Polymer thin film transistors were prepared by using a solution method and exhibited high and balanced hole and electron mobility of up to 0.46 cm 2  V -1  s -1 , which suggested that these copolymers are promising ambipolar semiconductor materials. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Comparison of mass balance, energy consumption and cost of composting facilities for different types of organic waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang Huijun; Matsuto, Toshihiko, E-mail: matsuto@eng.hokudai.ac.jp

2011-03-15

Mass balance, energy consumption and cost are basic pieces of information necessary for selecting a waste management technology. In this study, composting facilities that treat different types of organic waste were studied by questionnaire survey and via a chemical analysis of material collected at the facilities. The mass balance was calculated on a dry weight basis because the moisture content of organic waste was very high. Even though the ratio of bulking material to total input varied in the range 0-65% on a dry basis, the carbon and ash content, carbon/nitrogen ratio, heavy metal content and inorganic nutrients in themore » compost were clearly influenced by the different characteristics of the input waste. The use of bulking material was not correlated with ash or elemental content in the compost. The operating costs were categorised into two groups. There was some economy of scale for wages and maintenance cost, but the costs for electricity and fuel were proportional to the amount of waste. Differences in operating costs can be explained by differences in the process characteristics.« less

A spatial-temporal method for assessing the energy balance dynamics of partially sealed surfaces.

NASA Astrophysics Data System (ADS)

Pipkins, Kyle; Kleinschmit, Birgit; Wessolek, Gerd

2017-04-01

The effects of different types of sealed surfaces on the surface energy balance have been well-studied in the past. However, these field studies typically aggregate these surfaces into continuous units. The proposed method seeks to disaggregate such surfaces into paving and seam areas using spatial methods, and to consider the temperature dynamics under wet and dry conditions between these two components. This experimental work is undertaken using a thermal camera to record a time series of images over two lysimeters with differing levels of surface sealing. The images are subsequently decomposed into component materials using object-based image analysis and compared on the basis of both the surface materials as well as the spatial configuration of materials. Finally, a surface energy balance method is used to estimate evaporation rates from the surfaces, both separately for the different surface components as well as using the total surface mean. Results are validated using the output of the weighing lysimeter. Our findings will determine whether the explicitly spatial method is an improvement over the mean aggregate method.

A Thermodynamics Course Package in Onenote

ERIC Educational Resources Information Center

Falconer, John L.; Nicodemus, Garret D.; Medlin, J. Will; deGrazia, Janet; McDanel, Katherine P.

2014-01-01

A ready-to-use package of active-learning materials for a semester-long chemical engineering thermodynamics course was prepared for instructors, and similar materials are being prepared for a material and energy balance course. The course package includes ConcepTests, explanations of the ConcepTests for instructors, links to screencasts, chapter…

Instability of 2D Flows to Hydrostatic 3D Perturbations.

NASA Astrophysics Data System (ADS)

Straub, David N.

2003-01-01

Considered here is the evolution of three-dimensional perturbations to the hydrostatic equations linearized about a two-dimensional base state U. Motivated by an argument by T. Warn, this study begins with the nonrotating, unstratified case, and draws analogies between the perturbation equations and equations describing evolution of material line elements and scalar gradients embedded in the same 2D flow. When U is chaotic, both scalar gradients and line elements are characterized by rapid growth, and this leads one to suspect that the perturbations behave similarly. A generalized Okubo-Weiss parameter is proposed, and it is argued that this gives a reasonable litmus test for identifying regions where growth is most probable. Rotation modifies the generalized Okubo-Weiss parameter and tends to curb growth of the perturbation fields, as expected. It is also pointed out that, in realistic geophysical settings, the stability parameter can be suggestive of growth locally, even when a globally defined Rossby number is small.Also considered is the effect of a constant stratification. The perturbation equations can then be separated into vertical modes that have simple sinusoidal structures. The equations describing the evolution of a given mode take a form analogous to the shallow water equations, linearized about U. Numerical simulations of these, assuming a simple but chaotic prescription of U, are carried out. For sufficiently strong stratification, a balance dynamics similar to that suggested by Riley, Metcalfe, and Weissman is recovered. For a given value of the buoyancy frequency N, however, this balance breaks down at high vertical wavenumbers. For high vertical wavenumbers, the modified Okubo-Weiss parameter once again appears to give a potentially useful indication of when growth should be expected. When the Rossby number is small, this criterion predicts stability, and growth occurs only when stratification effects are comparable to or larger than rotational effects. More specifically, growth is seen when the relevant Rossby radius is comparable to or larger than the characteristic length scale of U. It is also found in this limit that approximate geostrophic adjustment occurs prior to growth.

Consecutive Course Modules Developed with Simple Materials to Facilitate the Learning of Basic Concepts in Astronomy

ERIC Educational Resources Information Center

Okulu, Hasan Zuhtu; Oguz-Unver, Ayse

2015-01-01

From the perspective of teaching, the huge natural laboratory that astronomy provides constitutes the most prominent connection between astronomy and other branches of science. The purpose of this research was to provide educators with activities of observation using simple materials that were developed to facilitate the teaching of basic concepts…

A Medieval Clock Made out of Simple Materials

ERIC Educational Resources Information Center

Danese, B.; Oss, S.

2008-01-01

A cheap replica of the verge-and-foliot clock has been built from simple materials. It is a didactic tool of great power for physics teaching at every stage of schooling, in particular at university level. An account is given of its construction and its working principles, together with motivated examples of a few activities. (Contains 3 tables…

A Simple Method for Determination of the Density of Granular Materials

ERIC Educational Resources Information Center

Tsutsumanova, G. G.; Kirilov, K. M.; Russev, S. C.

2012-01-01

A simple experiment using low cost equipment for the determination of the density of granular materials, without immersing them in a liquid, is presented. It is based only on the ideal gas state equation, so it is a good experimental task for undergraduate and high school students. (Contains 2 tables and 5 figures.)

Development and implementation of an automatic integration system for fibre optic sensors in the braiding process with the objective of online-monitoring of composite structures

NASA Astrophysics Data System (ADS)

Hufenbach, W.; Gude, M.; Czulak, A.; Kretschmann, Martin

2014-04-01

Increasing economic, political and ecological pressure leads to steadily rising percentage of modern processing and manufacturing processes for fibre reinforced polymers in industrial batch production. Component weights beneath a level achievable by classic construction materials, which lead to a reduced energy and cost balance during product lifetime, justify the higher fabrication costs. However, complex quality control and failure prediction slow down the substitution by composite materials. High-resolution fibre-optic sensors (FOS), due their low diameter, high measuring point density and simple handling, show a high applicability potential for an automated sensor-integration in manufacturing processes, and therefore the online monitoring of composite products manufactured in industrial scale. Integrated sensors can be used to monitor manufacturing processes, part tests as well as the component structure during product life cycle, which simplifies allows quality control during production and the optimization of single manufacturing processes.[1;2] Furthermore, detailed failure analyses lead to a enhanced understanding of failure processes appearing in composite materials. This leads to a lower wastrel number and products of a higher value and longer product life cycle, whereby costs, material and energy are saved. This work shows an automation approach for FOS-integration in the braiding process. For that purpose a braiding wheel has been supplemented with an appliance for automatic sensor application, which has been used to manufacture preforms of high-pressure composite vessels with FOS-networks integrated between the fibre layers. All following manufacturing processes (vacuum infiltration, curing) and component tests (quasi-static pressure test, programmed delamination) were monitored with the help of the integrated sensor networks. Keywords: SHM, high-pressure composite vessel, braiding, automated sensor integration, pressure test, quality control, optic-fibre sensors, Rayleigh, Luna Technologies

Mechanistic Studies Of Combustion And Structure Formation During Combustion Synthesis Of Advanced Materials: Phase Separation Mechanism For Bio-Alloys

NASA Technical Reports Server (NTRS)

Varma, A.; Lau, C.; Mukasyan, A.

2003-01-01

Among all implant materials, Co-Cr-Mo alloys demonstrate perhaps the most useful balance of resistance to corrosion, fatigue and wear, along with strength and biocompatibility [1]. Currently, these widely used alloys are produced by conventional furnace technology. Owing to high melting points of the main alloy elements (e.g. Tm.p.(Co) 1768 K), high-temperature furnaces and long process times (several hours) are required. Therefore, attempts to develop more efficient and flexible methods for production of such alloys with superior properties are of great interest. The synthesis of materials using combustion phenomena is an advanced approach in powder metallurgy [2]. The process is characterized by unique conditions involving extremely fast heating rates (up to 10(exp 6 K/s), high temperatures (up to 3500 K), and short reaction times (on the order of seconds). As a result, combustion synthesis (CS) offers several attractive advantages over conventional metallurgical processing and alloy development technologies. The foremost is that solely the heat of chemical reaction (instead of an external source) supplies the energy for the synthesis. Also, simple equipment, rather than energy-intensive high-temperature furnaces, is sufficient. This work was devoted to experiments on CS of Co-based alloys by utilizing thermite (metal oxide-reducing metal) reactions, where phase separation subsequently produces materials with tailored compositions and properties. Owing to high reaction exothermicity, the CS process results in a significant increase of temperature (up to 3000 C), which is higher than melting points of all products. Since the products differ in density, phase separation may be a gravitydriven process: the heavy (metallic phase) settles while the light (slag) phase floats. The goal was to determine if buoyancy is indeed the major mechanism that controls phase segregation.

Pickup protons and pressure-balanced structures: Voyager 2 observations in merged interaction regions near 35 AU

NASA Astrophysics Data System (ADS)

Burlaga, L. F.; Ness, N. F.; Belcher, J. W.; Szabo, A.; Isenberg, P. A.; Lee, M. A.

1994-11-01

Five pressure-balanced structures, each with a scale of the order of a few hundredths of an astonomical unit (AU), were identified in two merged interaction regions (MIRs) near 35 AU in the Voyager 2 plasma and magnetic field data. They include a tangential discontinuity, simple and complex magnetic holes, slow correlated variations among the plasma and magnetic field parameters, and complex uncorrelated variations among the parameters. The changes in the magnetic pressure in these events are balanced by changes in the pressure of interstellar pickup protons. Thus the pickup protons probably play a major role in the dynamics of the MIRs. The solar wind proton and electron pressures are relatively unimportant in the MIRs at 35 AU and beyond. The region near 35 AU is transition region: the Sun is the source of the magnetic field, but the interstellar medium in source of pickups protons. Relative to the solar wind proton guyroadius, the thicknesses of the discontinuities and simple magnetic holes observed near 35 AU are at least an order of magnitude greater than those observed at 1 AU. However, the thicknesses of the tangential discontinuity and simple magnetic holes observed near 35 AU (in units of the pickup proton Larmor radius) are comparable to those observed at 1 AU (in units of the solar wind proton gyroradius). Thus the gyroradius of interstellar pickup protons controls the thickness of current sheets near 35 AU. We determine the interstellar pickup proton pressure in the PBSs. Using a model for the pickup proton temperature, we estimate that the average interstellar pickup proton pressure, temperature, and density in the MIRs at 35 AU are (0.53 +/- 0.14) x 10-12 erg/cu cm, (5.8 +/- 0.4) x 106 K and (7 +/- 2) x 10-4/cu cm.

Optical identification using imperfections in 2D materials

NASA Astrophysics Data System (ADS)

Cao, Yameng; Robson, Alexander J.; Alharbi, Abdullah; Roberts, Jonathan; Woodhead, Christopher S.; Noori, Yasir J.; Bernardo-Gavito, Ramón; Shahrjerdi, Davood; Roedig, Utz; Fal'ko, Vladimir I.; Young, Robert J.

2017-12-01

The ability to uniquely identify an object or device is important for authentication. Imperfections, locked into structures during fabrication, can be used to provide a fingerprint that is challenging to reproduce. In this paper, we propose a simple optical technique to read unique information from nanometer-scale defects in 2D materials. Imperfections created during crystal growth or fabrication lead to spatial variations in the bandgap of 2D materials that can be characterized through photoluminescence measurements. We show a simple setup involving an angle-adjustable transmission filter, simple optics and a CCD camera can capture spatially-dependent photoluminescence to produce complex maps of unique information from 2D monolayers. Atomic force microscopy is used to verify the origin of the optical signature measured, demonstrating that it results from nanometer-scale imperfections. This solution to optical identification with 2D materials could be employed as a robust security measure to prevent counterfeiting.

Experimental Testing of Corpuscular Radiation Detectors. Volume 1. Revision 1

DTIC Science & Technology

1989-09-07

several layers of Sflexible Permag metglass); (c) 1/4" lead shield, against X-rays; (d) Cadmium/boron/lead shield against 14 MeV neutrons. I * I In...balance. Tn Figure 2.3 (d) the shielding of the torsion balance has been complemented with a PERMAG metglass magnetic shield. This is how the sensor looks...dB. The torsion balance was shielded by several layers of PERMAG U high-mu flexible Metglass material. in these two integrations, no lead shield was

Size-assortative mating and sexual size dimorphism are predictable from simple mechanics of mate-grasping behavior

PubMed Central

2010-01-01

Background A major challenge in evolutionary biology is to understand the typically complex interactions between diverse counter-balancing factors of Darwinian selection for size assortative mating and sexual size dimorphism. It appears that rarely a simple mechanism could provide a major explanation of these phenomena. Mechanics of behaviors can predict animal morphology, such like adaptations to locomotion in animals from various of taxa, but its potential to predict size-assortative mating and its evolutionary consequences has been less explored. Mate-grasping by males, using specialized adaptive morphologies of their forelegs, midlegs or even antennae wrapped around female body at specific locations, is a general mating strategy of many animals, but the contribution of the mechanics of this wide-spread behavior to the evolution of mating behavior and sexual size dimorphism has been largely ignored. Results Here, we explore the consequences of a simple, and previously ignored, fact that in a grasping posture the position of the male's grasping appendages relative to the female's body is often a function of body size difference between the sexes. Using an approach taken from robot mechanics we model coercive grasping of females by water strider Gerris gracilicornis males during mating initiation struggles. We determine that the male optimal size (relative to the female size), which gives the males the highest grasping force, properly predicts the experimentally measured highest mating success. Through field sampling and simulation modeling of a natural population we determine that the simple mechanical model, which ignores most of the other hypothetical counter-balancing selection pressures on body size, is sufficient to account for size-assortative mating pattern as well as species-specific sexual dimorphism in body size of G. gracilicornis. Conclusion The results indicate how a simple and previously overlooked physical mechanism common in many taxa is sufficient to account for, or importantly contribute to, size-assortative mating and its consequences for the evolution of sexual size dimorphism. PMID:21092131

Basic Body Awareness Therapy for patients with stroke: Experiences among participating patients and physiotherapists.

PubMed

Lindvall, Mialinn Arvidsson; Anderzén Carlsson, Agneta; Forsberg, Anette

2016-01-01

After a stroke many patients have muscle weakness, spasticity and compromised sensation leading to decreased postural stability. Basic Body Awareness Therapy includes slow movements that challenge postural control. The aim was to describe experiences of 8 weeks of Basic Body Awareness Therapy from the perspective of both patients with stroke and physiotherapists. This study had a qualitative design. Twenty-one patients and four physiotherapists were interviewed. The interviews were analysed using manifest and latent content analysis. One overall theme emerged "Simple yet challenging" which was based on six categories: "Facing one's limitations", "Individualized movements", "A feeling of harmony", "Improved balance", "Integrated knowledge" and "Frustration and doubt". The patients described improvement in balance and stability, as well as increased wellbeing. The patients and physiotherapists related that Basic Body Awareness Therapy challenges balance but also provides an opportunity to reflect on the body. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Dendritic excitation–inhibition balance shapes cerebellar output during motor behaviour

PubMed Central

Jelitai, Marta; Puggioni, Paolo; Ishikawa, Taro; Rinaldi, Arianna; Duguid, Ian

2016-01-01

Feedforward excitatory and inhibitory circuits regulate cerebellar output, but how these circuits interact to shape the somatodendritic excitability of Purkinje cells during motor behaviour remains unresolved. Here we perform dendritic and somatic patch-clamp recordings in vivo combined with optogenetic silencing of interneurons to investigate how dendritic excitation and inhibition generates bidirectional (that is, increased or decreased) Purkinje cell output during self-paced locomotion. We find that granule cells generate a sustained depolarization of Purkinje cell dendrites during movement, which is counterbalanced by variable levels of feedforward inhibition from local interneurons. Subtle differences in the dendritic excitation–inhibition balance generate robust, bidirectional changes in simple spike (SSp) output. Disrupting this balance by selectively silencing molecular layer interneurons results in unidirectional firing rate changes, increased SSp regularity and disrupted locomotor behaviour. Our findings provide a mechanistic understanding of how feedforward excitatory and inhibitory circuits shape Purkinje cell output during motor behaviour. PMID:27976716

Multipoint fiber-optic laser-ultrasonic actuator based on fiber core-opened tapers.

PubMed

Tian, Jiajun; Dong, Xiaolong; Gao, Shimin; Yao, Yong

2017-11-27

In this study, a novel fiber-optic, multipoint, laser-ultrasonic actuator based on fiber core-opened tapers (COTs) is proposed and demonstrated. The COTs were fabricated by splicing single-mode fibers using a standard fiber splicer. A COT can effectively couple part of a core mode into cladding modes, and the coupling ratio can be controlled by adjusting the taper length. Such characteristics are used to obtain a multipoint, laser-ultrasonic actuator with balanced signal strength by reasonably controlling the taper lengths of the COTs. As a prototype, we constructed an actuator that generated ultrasound at four points with a balanced ultrasonic strength by connecting four COTs with coupling ratios of 24.5%, 33.01%, 49.51%, and 87.8% in a fiber link. This simple-to-fabricate, multipoint, laser-ultrasonic actuator with balanced ultrasound signal strength has potential applications in fiber-optic ultrasound testing technology.

Ephemeral penalty functions for contact-impact dynamics

NASA Technical Reports Server (NTRS)

De La Fuente, Horacio M.; Felippa, Carlos A.

1991-01-01

The use of penalty functions to treat a class of structural contact-impact problems is investigated, with emphasis on ones in which the impact phenomena are primarily nondestructive in nature and in which only the gross characterization of the response is required. The dynamic equations of motion are integrated by the difference method. The penalty is represented as an ephemeral fictitious nonlinear spring that is inserted on anticipation of contact. The magnitude and variation of the penalty force is determined through energy balancing considerations. The 'bell shape' of the penalty force function for positive gap was found to be satisfactory, as it depends on only two parameters that can be directly assigned the physical meaning of force and distance. The determination of force law parameters by energy balance worked well. The incorporation of restitution coefficients by the area balancing method yielded excellent results, and no substantial modifications are anticipated. Extensional penalty springs are obviously sufficient for the simple examples treated.

Reviews Book: The Babylonian Theorem Video Game: BrainBox360 (Physics Edition) Book: Teaching and Learning Science: Towards a Personalized Approach Book: Good Practice in Science Teaching: What Research Has to Say Equipment: PAPERSHOW Equipment: SEP Steady State Bottle Kit Equipment: Sciencescope Datalogging Balance Equipment: USB Robot Arm Equipment: Sciencescope Spectrophotometer Web Watch

NASA Astrophysics Data System (ADS)

2010-07-01

WE RECOMMEND Good Practice in Science Teaching: What Research Has to Say Book explores and summarizes the research Steady State Bottle Kit Another gem from SEP Sciencescope Datalogging Balance Balance suits everyday use Sciencescope Spectrophotometer Device displays clear spectrum WORTH A LOOK The Babylonian Theorem Text explains ancient Egyptian mathematics BrainBox360 (Physics Edition) Video game tests your knowledge Teaching and Learning Science: Towards a Personalized Approach Book reveals how useful physics teachers really are PAPERSHOW Gadget kit is useful but has limitations Robotic Arm Kit with USB PC Interface Robot arm teaches programming WEB WATCH Simple applets teach complex topics

A new accounting system for financial balance based on personnel cost after the introduction of a DPC/DRG system.

PubMed

Nakagawa, Yoshiaki; Takemura, Tadamasa; Yoshihara, Hiroyuki; Nakagawa, Yoshinobu

2011-04-01

A hospital director must estimate the revenues and expenses not only in a hospital but also in each clinical division to determine the proper management strategy. A new prospective payment system based on the Diagnosis Procedure Combination (DPC/PPS) introduced in 2003 has made the attribution of revenues and expenses for each clinical department very complicated because of the intricate involvement between the overall or blanket component and a fee-for service (FFS). Few reports have so far presented a programmatic method for the calculation of medical costs and financial balance. A simple method has been devised, based on personnel cost, for calculating medical costs and financial balance. Using this method, one individual was able to complete the calculations for a hospital which contains 535 beds and 16 clinics, without using the central hospital computer system.

Surgical technique for balancing posterior spinal fusions to the pelvis using the T square of Tolo.

PubMed

Andras, Lindsay; Yamaguchi, Kent T; Skaggs, David L; Tolo, Vernon T

2012-12-01

Correcting pelvic obliquity and improving sitting balance in neuromuscular scoliosis often requires fixation to the pelvis. We describe the use of a T square instrument to assist intraoperatively in evaluating the alignment of these curves and achieving balance in the coronal plane. The T square instrument was constructed with a vertical limb perpendicular to 2 horizontal limbs in a T formation. At the conclusion of the instrumentation and preliminary reduction maneuvers, the T square was positioned with the horizontal limbs parallel to the pelvis and the vertical limb in line with the central sacral line. If the spine and pelvis were well balanced, fluoroscopic images demonstrated that the superior aspect of the vertical limb of the T square was crossing the vertebral body of T1. If this was not shown, then some combination of compression, distraction, or a change in the contouring of the rods was performed until this balance was achieved. In this series, we describe case examples in which the T square has been successfully used to aid in achieving balance in the coronal plane. This technique helps to overcome the challenges with positioning and imaging often encountered in managing these long, rigid curves. The T square is a useful adjunct in balancing posterior spinal fusions and evaluating the correction of pelvic obliquity in cases of neuromuscular scoliosis. This novel, yet simple, T square technique can be used for any method of posterior spinal fusion with lumbopelvic fixation to assist in the intraoperative evaluation and achievement of balance in the coronal plane and has become routine at our institution. IV.

Engineering Curriculum Development: Balancing Employer Needs and National Interest--A Case Study.

ERIC Educational Resources Information Center

Buniyamin, Norlida; Mohamad, Zainuddin

The Faculty of Mechanical Engineering at the University Teknologi MARA, Malaysia, developed an undergraduate-level engineering curriculum that balances national interests with those of employers and academics. The curriculum was based on materials posted at the Internet sites of universities in the United States, United Kingdom, and Malaysia…

The "Balance Intervention" for Promoting Caloric Compensatory Behaviours in Response to Overeating: A Formative Evaluation

ERIC Educational Resources Information Center

Wammes, Birgitte; Breedveld, Boudewijn; Kremers, Stef; Brug, Johannes

2006-01-01

To help people prevent weight gain, the Netherlands Nutrition Centre initiated the "balance intervention", which promotes moderation of food intake and/or increased physical activity in response to occasions of overeating. The aim of this study was to determine whether intervention materials were appreciated, encouraged information…

Material Flow Analysis as a Tool to improve Waste Management Systems: The Case of Austria.

PubMed

Allesch, Astrid; Brunner, Paul H

2017-01-03

This paper demonstrates the power of material flow analysis (MFA) for designing waste management (WM) systems and for supporting decisions with regards to given environmental and resource goals. Based on a comprehensive case study of a nationwide WM-system, advantages and drawbacks of a mass balance approach are discussed. Using the software STAN, a material flow system comprising all relevant inputs, stocks and outputs of wastes, products, residues, and emissions is established and quantified. Material balances on the level of goods and selected substances (C, Cd, Cr, Cu, Fe, Hg, N, Ni, P, Pb, Zn) are developed to characterize this WM-system. The MFA results serve well as a base for further assessments. Based on given goals, stakeholders engaged in this study selected the following seven criteria for evaluating their WM-system: (i) waste input into the system, (ii) export of waste (iii) gaseous emissions from waste treatment plants, (iv) long-term gaseous and liquid emissions from landfills, (v) waste being recycled, (vi) waste for energy recovery, (vii) total waste landfilled. By scenario analysis, strengths and weaknesses of different measures were identified. The results reveal the benefits of a mass balance approach due to redundancy, data consistency, and transparency for optimization, design, and decision making in WM.

Bioactive food stimulants of sympathetic activity: effect on 24-h energy expenditure and fat oxidation.

PubMed

Belza, A; Jessen, A B

2005-06-01

Bioactive food ingredients influence energy balance by exerting weak thermogenic effects. We studied whether the thermogenic effect of a combination of capsaicin, green tea extract (catechins and caffeine), tyrosine, and calcium was maintained after 7-day treatment and whether local effects in the gastric mucosa were involved in the efficacy. The present study was designed as a 3-way crossover, randomised, placebo-controlled, double-blinded intervention. Department of Human Nutrition, RVAU, Denmark. A total of 19 overweight to obese men (BMI: 28.0+/-2.7 kg/m2) were recruited by advertising locally. The subjects took the supplements for a period of 7 days. The supplements were administrated as a simple supplement with the bioactive ingredients, a similar enterocoated version, or placebo. In all, 24-h energy expenditure (EE), substrate oxidations, spontaneous physical activity (SPA), and heart rate were measured in respiration chambers on the seventh day of each test period. After adjustment for changes in body weight and SPA, 24-h EE was increased by 160 kJ/day (95% CI: 15-305) by the simple preparation as compared to placebo, whereas the enterocoated preparation had no such effect (53 kJ/day, -92 to 198); simple vs enterocoated versions (P=0.09). The simple preparation produced a deficit in 24-h energy balance of 193 kJ/day (49-338, P=0.03). Fat and carbohydrate oxidation were equally increased by the supplements. A supplement containing bioactive food ingredients increased daily EE by approximately 200 kJ or 2%, without raising the heart rate or any observed adverse effects. The lack of effect of the enterocoated preparation suggests that a local action of capsaicin in the gastric mucosa is a prerequisite for exerting the thermogenic effect.

A simple test of choice stepping reaction time for assessing fall risk in people with multiple sclerosis.

PubMed

Tijsma, Mylou; Vister, Eva; Hoang, Phu; Lord, Stephen R

2017-03-01

Purpose To determine (a) the discriminant validity for established fall risk factors and (b) the predictive validity for falls of a simple test of choice stepping reaction time (CSRT) in people with multiple sclerosis (MS). Method People with MS (n = 210, 21-74y) performed the CSRT, sensorimotor, balance and neuropsychological tests in a single session. They were then followed up for falls using monthly fall diaries for 6 months. Results The CSRT test had excellent discriminant validity with respect to established fall risk factors. Frequent fallers (≥3 falls) performed significantly worse in the CSRT test than non-frequent fallers (0-2 falls). With the odds of suffering frequent falls increasing 69% with each SD increase in CSRT (OR = 1.69, 95% CI: 1.27-2.26, p = <0.001). In regression analysis, CSRT was best explained by sway, time to complete the 9-Hole Peg test, knee extension strength of the weaker leg, proprioception and the time to complete the Trails B test (multiple R 2   =   0.449, p < 0.001). Conclusions A simple low tech CSRT test has excellent discriminative and predictive validity in relation to falls in people with MS. This test may prove useful in documenting longitudinal changes in fall risk in relation to MS disease progression and effects of interventions. Implications for rehabilitation Good choice stepping reaction time (CSRT) is required for maintaining balance. A simple low-tech CSRT test has excellent discriminative and predictive validity in relation to falls in people with MS. This test may prove useful documenting longitudinal changes in fall risk in relation to MS disease progression and effects of interventions.

Model reduction for Space Station Freedom

NASA Technical Reports Server (NTRS)

Williams, Trevor

1992-01-01

Model reduction is an important practical problem in the control of flexible spacecraft, and a considerable amount of work has been carried out on this topic. Two of the best known methods developed are modal truncation and internal balancing. Modal truncation is simple to implement but can give poor results when the structure possesses clustered natural frequencies, as often occurs in practice. Balancing avoids this problem but has the disadvantages of high computational cost, possible numerical sensitivity problems, and no physical interpretation for the resulting balanced 'modes'. The purpose of this work is to examine the performance of the subsystem balancing technique developed by the investigator when tested on a realistic flexible space structure, in this case a model of the Permanently Manned Configuration (PMC) of Space Station Freedom. This method retains the desirable properties of standard balancing while overcoming the three difficulties listed above. It achieves this by first decomposing the structural model into subsystems of highly correlated modes. Each subsystem is approximately uncorrelated from all others, so balancing them separately and then combining yields comparable results to balancing the entire structure directly. The operation count reduction obtained by the new technique is considerable: a factor of roughly r(exp 2) if the system decomposes into r equal subsystems. Numerical accuracy is also improved significantly, as the matrices being operated on are of reduced dimension, and the modes of the reduced-order model now have a clear physical interpretation; they are, to first order, linear combinations of repeated-frequency modes.

Microfabrication of hierarchical structures for engineered mechanical materials

NASA Astrophysics Data System (ADS)

Vera Canudas, Marc

Materials found in nature present, in some cases, unique properties from their constituents that are of great interest in engineered materials for applications ranging from structural materials for the construction of bridges, canals and buildings to the fabrication of new lightweight composites for airplane and automotive bodies, to protective thin film coatings, amongst other fields. Research in the growing field of biomimetic materials indicates that the micro-architectures present in natural materials are critical to their macroscopic mechanical properties. A better understanding of the effect that structure and hierarchy across scales have on the material properties will enable engineered materials with enhanced properties. At the moment, very few theoretical models predict mechanical properties of simple materials based on their microstructures. Moreover these models are based on observations from complex biological systems. One way to overcome this challenge is through the use of microfabrication techniques to design and fabricate simple materials, more appropriate for the study of hierarchical organizations and microstructured materials. Arrays of structures with controlled geometry and dimension can be designed and fabricated at different length scales, ranging from a few hundred nanometers to centimeters, in order to mimic similar systems found in nature. In this thesis, materials have been fabricated in order to gain fundamental insight into the complex hierarchical materials found in nature and to engineer novel materials with enhanced mechanical properties. The materials fabricated here were mechanically characterized and compared to simple mechanics models to describe their behavior with the goal of applying the knowledge acquired to the design and synthesis of future engineered materials with novel properties.

Tank 12H Acidic Chemical Cleaning Sample Analysis And Material Balance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martino, C. J.; Reboul, S. H.; Wiersma, B. J.

2013-11-08

A process of Bulk Oxalic Acid (BOA) chemical cleaning was performed for Tank 12H during June and July of 2013 to remove all or a portion of the approximately 4400 gallon sludge heel. Three strikes of oxalic acid (nominally 4 wt% or 2 wt%) were used at 55°C and tank volumes of 96- to 140-thousand gallons. This report details the sample analysis of a scrape sample taken prior to BOA cleaning and dip samples taken during BOA cleaning. It also documents a rudimentary material balance for the Tank 12H cleaning results.

Doping-assisted defect control in compound semiconductors

DOEpatents

Specht, Petra; Weber, Eicke R.; Weatherford, Todd Russell

2006-07-11

The present invention relates to the production of thin film epilayers of III–V and other compounds with acceptor doping wherein the acceptor thermally stabilizes the epilayer, stabilize the naturally incorporated native defect population and therewith maintain the epilayer's beneficial properties upon annealing among other advantageous effects. In particular, balanced doping in which the acceptor concentration is similar to (but does not exceed) the antisite defects in the as-grown material is shown to be particularly advantageous in providing thermal stability, high resistivity and ultrashort trapping times. In particular, MBE growth of LT-GaAs epilayers with balanced Be doping is described in detail. The growth conditions greatly enhance the materials reproducibility (that is, the yield in processed devices). Such growth techniques can be transferred to other III–V materials if the growth conditions are accurately reproduced. Materials produced herein also demonstrate advantages in reproducibility, reliability and radiation hardening.

Relationships Between Simple Toe Elevation Angle in the Standing Position and Dynamic Balance and Fall Risk Among Community-Dwelling Older Adults.

PubMed

Takatori, Katsuhiko; Matsumoto, Daisuke

2015-10-01

To investigate the relationships between toe elevation ability in the standing position and dynamic balance and fall risk among community-dwelling older adults. Cross-sectional survey. General community. Community-dwelling older adults (N = 287). Toe elevation angles in the standing position. Intra-rater and inter-rater reliability of measurements of the toe elevation angle was high (internal coefficient of correlation [ICC] (1,2) = 0.94 for the former and ICC (2,1) = 0.90 for the latter). Significant correlations were found between the toe elevation angle and age (r = -0.20, P < .01), 5-m walking time (r = -0.31, P < .01), Functional Reach Test (r = 0.36, P < .01), Timed Up and Go Test (r = -0.36, P < .01), and Chair Stand Test (r = 0.26, P < .01). Subjects who experienced a fall in the previous 6 months had a significantly lower toe elevation angle compared with subjects who did not experience a fall (t = 2.19, P < .05). Multiple regression analysis revealed that results of the Functional Reach Test (β = .22, P < .001) and Timed Up and Go Test (β = -0.74, P < .001) were significantly associated with the toe elevation angle. Toe elevation angle was an index of dynamic balance ability and appears to be a simple screening test for fall risk in community-dwelling older adults. Copyright © 2015 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Constrained Allocation Flux Balance Analysis

PubMed Central

Mori, Matteo; Hwa, Terence; Martin, Olivier C.

2016-01-01

New experimental results on bacterial growth inspire a novel top-down approach to study cell metabolism, combining mass balance and proteomic constraints to extend and complement Flux Balance Analysis. We introduce here Constrained Allocation Flux Balance Analysis, CAFBA, in which the biosynthetic costs associated to growth are accounted for in an effective way through a single additional genome-wide constraint. Its roots lie in the experimentally observed pattern of proteome allocation for metabolic functions, allowing to bridge regulation and metabolism in a transparent way under the principle of growth-rate maximization. We provide a simple method to solve CAFBA efficiently and propose an “ensemble averaging” procedure to account for unknown protein costs. Applying this approach to modeling E. coli metabolism, we find that, as the growth rate increases, CAFBA solutions cross over from respiratory, growth-yield maximizing states (preferred at slow growth) to fermentative states with carbon overflow (preferred at fast growth). In addition, CAFBA allows for quantitatively accurate predictions on the rate of acetate excretion and growth yield based on only 3 parameters determined by empirical growth laws. PMID:27355325

Mathematical model of whole-process calculation for bottom-blowing copper smelting

NASA Astrophysics Data System (ADS)

Li, Ming-zhou; Zhou, Jie-min; Tong, Chang-ren; Zhang, Wen-hai; Li, He-song

2017-11-01

The distribution law of materials in smelting products is key to cost accounting and contaminant control. Regardless, the distribution law is difficult to determine quickly and accurately by mere sampling and analysis. Mathematical models for material and heat balance in bottom-blowing smelting, converting, anode furnace refining, and electrolytic refining were established based on the principles of material (element) conservation, energy conservation, and control index constraint in copper bottom-blowing smelting. Simulation of the entire process of bottom-blowing copper smelting was established using a self-developed MetCal software platform. A whole-process simulation for an enterprise in China was then conducted. Results indicated that the quantity and composition information of unknown materials, as well as heat balance information, can be quickly calculated using the model. Comparison of production data revealed that the model can basically reflect the distribution law of the materials in bottom-blowing copper smelting. This finding provides theoretical guidance for mastering the performance of the entire process.

Materialism and credit card use by college students.

PubMed

Pinto, M B; Parente, D H; Palmer, T S

2000-04-01

Much has been written in the popular press on credit card use and spending patterns of American college students. The proliferation of credit cards and their ease of acquisition ensure that students today have more opportunities for making more credit purchases than any other generation of college students. Little is known about the relationship between students' attitudes towards materialism and their use of credit cards. A study was conducted at three college campuses in the northeastern part of the United States where a total of 1,022 students were surveyed. Students' attitudes toward use of credit and their credit card balances were evaluated relative to their scores on Richins and Dawson's Materialism Scale (1992). Our findings suggest no significant difference between those individuals scoring high versus low on the Materialism Scale in terms of the number of credit cards owned and the average balance owed. Individuals high on materialism, however, significantly differed in terms of their uses for credit cards and their general attitude toward their use.

Scintillator material

DOEpatents

Anderson, D.F.; Kross, B.J.

1992-07-28

An improved scintillator material comprising cerium fluoride is disclosed. Cerium fluoride has been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to known scintillator materials such as thallium-doped sodium iodide, barium fluoride and bismuth germanate. As a result, cerium fluoride is favorably suited for use as a scintillator material in positron emission tomography. 4 figs.

Scintillator material

DOEpatents

Anderson, D.F.; Kross, B.J.

1994-06-07

An improved scintillator material comprising cerium fluoride is disclosed. Cerium fluoride has been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to known scintillator materials such as thallium-doped sodium iodide, barium fluoride and bismuth germanate. As a result, cerium fluoride is favorably suited for use as a scintillator material in positron emission tomography. 4 figs.

R package CityWaterBalance | Science Inventory | US EPA

EPA Pesticide Factsheets

CityWaterBalance provides a reproducible workflow for studying an urban water system. The network of urban water flows and storages can be modeled and visualized. Any city may be modeled with preassembled data, but data for US cities can be gathered via web services using this package and dependencies, geoknife and dataRetrieval. Urban water flows are difficult to comprehensively quantify. Although many important data sources are openly available, they are published by a variety of agencies in different formats, units, spatial and temporal resolutions. Increasingly, open data are made available via web services, which allow for automated, current retrievals. Integrating data streams and estimating the values of unmeasured urban water flows, however, remains needlessly time-consuming. In order to streamline a reproducible analysis, we have developed the CityWaterBalance package for the open source R language. The CityWaterBalance package for R is based on a simple model of the network of urban water flows and storages. The model may be run with data that has been pre-assembled by the user, or data can be retrieved by functions in CityWaterBalance and dependencies. CityWaterBalance can be used to quickly assemble a quantitative portrait of any urban water system. The systemic effects of water management decisions can be readily explored. Much of the data acquisition process for US cities can already be automated, while the package serves as a place-hold

Balanced Flow Meters without Moving Parts

NASA Technical Reports Server (NTRS)

Kelley, Anthony R.; VanBuskirk, Paul

2008-01-01

Balanced flow meters are recent additions to an established class of simple, rugged flow meters that contain no moving parts in contact with flow and are based on measurement of pressure drops across objects placed in flow paths. These flow meters are highly accurate, minimally intrusive, easily manufacturable, and reliable. A balanced flow meter can be easily mounted in a flow path by bolting it between conventional pipe flanges. A balanced flow meter can be used to measure the flow of any of a variety of liquids or gases, provided that it has been properly calibrated. Relative to the standard orifice-plate flow meter, the balanced flow meter introduces less turbulence and two times less permanent pressure loss and is therefore capable of offering 10 times greater accuracy and repeatability with less dissipation of energy. A secondary benefit of the reduction of turbulence is the reduction of vibration and up to 15 times less acoustic noise generation. Both the balanced flow meter and the standard orifice-plate flow meter are basically disks that contain holes and are instrumented with pressure transducers on their upstream and downstream faces. The most obvious difference between them is that the standard orifice plate contains a single, central hole while the balanced flow meter contains multiple holes. The term 'balanced' signifies that in designing the meter, the sizes and locations of the holes are determined in an optimization procedure that involves balancing of numerous factors, including volumetric flow, mass flow, dynamic pressure, kinetic energy, all in an effort to minimize such undesired effects as turbulence, pressure loss, dissipation of kinetic energy, and non-repeatability and nonlinearity of response over the anticipated range of flow conditions. Due to proper balancing of these factors, recent testing demonstrated that the balanced flow-meter performance was similar to a Venturi tube in both accuracy and pressure recovery, but featured reduced cost and pipe-length requirements.

Degradation Mechanisms in Blue Phosphorescent Organic Light-Emitting Devices by Exciton-Polaron Interactions: Loss in Quantum Yield versus Loss in Charge Balance.

PubMed

Zhang, Yingjie; Aziz, Hany

2017-01-11

We study the relative importance of deterioration of material quantum yield and charge balance to the electroluminescence stability of PHOLEDs, with a special emphasis on blue devices. Investigations show that the quantum yields of both host and emitter in the emission layer degrade due to exciton-polaron interactions and that the deterioration in material quantum yield plays the primary role in device degradation under operation. On the other hand, the results show that the charge balance factor is also affected by exciton-polaron interactions but only plays a secondary role in determining device stability. Finally, we show that the degradation mechanisms in blue PHOLEDs are fundamentally the same as those in green PHOLEDs. The limited stability of the blue devices is a result of faster deterioration in the quantum yield of the emitter.

Preparing "Chameleon Balls" from Natural Plants: Simple Handmade pH Indicator and Teaching Material for Chemical Education

NASA Astrophysics Data System (ADS)

1996-05-01

Some of the structures in Figure 1 from "Preparing "Chameleon Balls" from Natural Plants: Simple Handmade pH Indicator and Teaching Material for Chemical Education"[Kanda, N.; Asano, T.; Itoh, T.; Onoda, M. J. Chem. Educ. 1995, 72, 1131] were incorrect due to a staff error. The correct figure appears below.

A Simple Experiment to Demonstrate the Effects of Cracks on Materials Strength

ERIC Educational Resources Information Center

Sauls, Frederick C.

2011-01-01

A simple in-class experiment was designed to expose students to an aspect of materials science dealing with defects. Students break a series of paper strips to gauge the breaking strength. A precut transverse "crack" weakens the paper strip by a surprising amount. Adding a precut "crack stopper" greatly reduces the effect of the original "crack".…

Utility of remote sensing-based surface energy balance models to track water stress in rain-fed switchgrass under dry and wet conditions

NASA Astrophysics Data System (ADS)

Bhattarai, Nishan; Wagle, Pradeep; Gowda, Prasanna H.; Kakani, Vijaya G.

2017-11-01

The ability of remote sensing-based surface energy balance (SEB) models to track water stress in rain-fed switchgrass (Panicum virgatum L.) has not been explored yet. In this paper, the theoretical framework of crop water stress index (CWSI; 0 = extremely wet or no water stress condition and 1 = extremely dry or no transpiration) was utilized to estimate CWSI in rain-fed switchgrass using Landsat-derived evapotranspiration (ET) from five remote sensing based single-source SEB models, namely Surface Energy Balance Algorithm for Land (SEBAL), Mapping ET with Internalized Calibration (METRIC), Surface Energy Balance System (SEBS), Simplified Surface Energy Balance Index (S-SEBI), and Operational Simplified Surface Energy Balance (SSEBop). CWSI estimates from the five SEB models and a simple regression model that used normalized difference vegetation index (NDVI), near-surface temperature difference, and measured soil moisture (SM) as covariates were compared with those derived from eddy covariance measured ET (CWSIEC) for the 32 Landsat image acquisition dates during the 2011 (dry) and 2013 (wet) growing seasons. Results indicate that most SEB models can predict CWSI reasonably well. For example, the root mean square error (RMSE) ranged from 0.14 (SEBAL) to 0.29 (SSEBop) and the coefficient of determination (R2) ranged from 0.25 (SSEBop) to 0.72 (SEBAL), justifying the added complexity in CWSI modeling as compared to results from the simple regression model (R2 = 0.55, RMSE = 0.16). All SEB models underestimated CWSI in the dry year but the estimates from SEBAL and S-SEBI were within 7% of the mean CWSIEC and explained over 60% of variations in CWSIEC. In the wet year, S-SEBI mostly overestimated CWSI (around 28%), while estimates from METRIC, SEBAL, SEBS, and SSEBop were within 8% of the mean CWSIEC. Overall, SEBAL was the most robust model under all conditions followed by METRIC, whose performance was slightly worse and better than SEBAL in dry and wet years, respectively. Underestimation of CWSI under extremely dry soil conditions and the substantial role of SM in the regression model suggest that integration of SM in SEB models could improve their performances under dry conditions. These insights will provide useful guidance on the broader applicability of SEB models for mapping water stresses in switchgrass under varying geographical and meteorological conditions.

In Vitro Tensile Strength Study on Suturing Technique and Material.

PubMed

González-Barnadas, Albert; Camps-Font, Octavi; Espanya-Grifoll, Dunia; España-Tost, Antoni; Figueiredo, Rui; Valmaseda-Castellón, Eduard

2017-06-01

Suture technique and materials are important in preventing complications such as wound dehiscences. The purpose of this study was to determine the tensile strength of different suturing techniques, comparing several materials with different diameters. One hundred sixty sutures were performed using silk, e-PTFE, and 2 types of polyamide (monofilament and Supramid). Ten simple, 10 horizontal mattress, and 10 combinations of the two stitches were performed with 4-0 gauge of each material. Additionally, 10 simple sutures were performed with the 5-0 gauge of each material. The maximum tensile force resisted by each suture was recorded. When 5 mm of traction was applied, the polyamide monofilament resisted significantly better without untying or breaking compared with Supramid or silk, while the e-PTFE was superior to all the others. However, the force when e-PTFE 4-0 sutures untied or broke was lower than for either type of polyamide. The combined technique withstood a significantly higher tensile force before unknotting or breaking than did the simple and mattress stitches. The 5-0 gauges of silk and both types of polyamide showed lower tensile strengths than the 4-0 materials. Among the 5-0 sutures, Supramid showed a higher tensile strength than silk. The combined suture technique possessed greater tensile strength than did a simple or a horizontal mattress suture, and e-PTFE 4-0 withstood more traction without untying or breaking than did all the other materials, although at a lower tensile force. With the exception of e-PTFE, 4-0 sutures had greater tensile strength than did 5-0 sutures.

Quantification of colloidal and aqueous element transfer in soils: The dual-phase mass balance model

USGS Publications Warehouse

Bern, Carleton R.; Thompson, Aaron; Chadwick, Oliver A.

2015-01-01

Mass balance models have become standard tools for characterizing element gains and losses and volumetric change during weathering and soil development. However, they rely on the assumption of complete immobility for an index element such as Ti or Zr. Here we describe a dual-phase mass balance model that eliminates the need for an assumption of immobility and in the process quantifies the contribution of aqueous versus colloidal element transfer. In the model, the high field strength elements Ti and Zr are assumed to be mobile only as suspended solids (colloids) and can therefore be used to distinguish elemental redistribution via colloids from redistribution via dissolved aqueous solutes. Calculations are based upon element concentrations in soil, parent material, and colloids dispersed from soil in the laboratory. We illustrate the utility of this model using a catena in South Africa. Traditional mass balance models systematically distort elemental gains and losses and changes in soil volume in this catena due to significant redistribution of Zr-bearing colloids. Applying the dual-phase model accounts for this colloidal redistribution and we find that the process accounts for a substantial portion of the major element (e.g., Al, Fe and Si) loss from eluvial soil. In addition, we find that in illuvial soils along this catena, gains of colloidal material significantly offset aqueous elemental loss. In other settings, processes such as accumulation of exogenous dust can mimic the geochemical effects of colloid redistribution and we suggest strategies for distinguishing between the two. The movement of clays and colloidal material is a major process in weathering and pedogenesis; the mass balance model presented here is a tool for quantifying effects of that process over time scales of soil development.

Balanced and servo control surfaces

NASA Technical Reports Server (NTRS)

1930-01-01

Many reports on various control systems are available, but the results cannot be generally applied since the effect of particular changes of surface-form and mounting are subject to variations depending upon airfoil section and influences of airplane layout. This report presents a simple analysis of several control systems in more general use. Elevators, ailerons, and rudders are all discussed.

Analyzing the Cost Efficiency of Academic Departments and Instructional Personnel at State Universities.

ERIC Educational Resources Information Center

Norris, Robert G.

A cost-effectiveness model is presented for academic administrators to use in making evaluation and planning decisions related directly to the instructional activities of academic departments. The advantages seen in the model are that it is simple and flexible, concentrates on balancing income generated by the department to expenses incurred, and…

Earth Is My Home, Kit I.

ERIC Educational Resources Information Center

1971

Introducing the pupil to the science of ecology is the purpose of Scholastic's Earth Corps Ecology/Conservation Study Kits for grades 3-6. Simple terms are used to show how all living things are inter-related to their environment, to demonstrate the intricate and delicate balance of nature, and to point out how man's interference with nature's…

The Impact of Brain-Based Instruction on Reading Achievement in a Second-Grade Classroom

ERIC Educational Resources Information Center

McNamee, Merideth M.

2011-01-01

School accountability and high-stakes testing often shift classroom focus from the use of engaging learning activities that promote critical thinking and creativity to simple test preparation practices. Using brain research as a guide, educators may be able to improve test scores, while still providing a balanced education that promotes critical…

iSTEM: A Fibonacci Simple Ecosystem--Prey and Predator

ERIC Educational Resources Information Center

Garcia, Jorge

2014-01-01

The branch of biology that studies ecosystems, habitats, their developments, and the equilibrium of species is called conservation biology (Soule 1986). It is important to study this balance of species within an ecosystem, where species might live for a short period of time (such as mosquitoes, the main source of food for frogs) or live for…

77 FR 41841 - Self-Regulatory Organizations; Chicago Board Options Exchange, Incorporated; Notice of Filing and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-16

... Commission is publishing this notice to solicit comments on the proposed rule change from interested persons... System for processing as a simple market order(s) and any remaining balance of the stock leg will route... public interest, for the protection of investors, or otherwise in furtherance of the purposes of the Act...

Simple three-pool model accurately describes patterns of long-term litter decomposition in diverse climates

Treesearch

E. Carol Adair; William J. Parton; Steven J. Del Grosso; Shendee L. Silver; Mark E. Harmon; Sonia A. Hall; Ingrid C. Burke; Stephen C. Hart

2008-01-01

As atmospheric CO2 increases, ecosystem carbon sequestration will largely depend on how global changes in climate will alter the balance between net primary production and decomposition. The response of primary production to climatic change has been examined using well-validated mechanistic models, but the same is not true for decomposition, a...

Theoretical Aspect of Low Pressure Discharges in Simple Gasses

DTIC Science & Technology

1994-03-28

electrons, ions and atoms satisfies the relation: NeNi /Na - [exp-Ei/T]GeGi/Ga (5.7) where Ei ionization energy and Ga - 7.*jgjaexp -{(Eja-Eoa)/T) (5.8) for...ionization with recombination gives neni /na = aiOWi (5.14) while balancing photoionization with radiative recombination gives neni /na = apl/jp (5.15

Get Kids Moving: Simple Activities To Build Gross-Motor Skills.

ERIC Educational Resources Information Center

Texas Child Care, 2003

2003-01-01

Highlights the importance of activities to build gross motor skills and provides hints for encouraging such activities. Specific areas of activities presented are: (1) running and jumping; (2) music games; (3) action games; (4) races; (5) bed sheets or parachutes; (6) hula hoops; (7) balls; (8) batting; (9) balance; and (10) creative movement. (SD)

Fire in the Sky--From Big Bang to Big Money: Outdoor Education and Sustainable Development. Part One.

ERIC Educational Resources Information Center

Walker, Rod

1998-01-01

Within diverse outdoor educational activities, a core experience of connection with the earth balances self, others, and nature with elements of ritual. Most effective when experiential, integrated, and technologically simple, the core experience's educative power lies in awakening awareness of interconnectedness between human and nonhuman life.…

EFFECTS OF REVERSE OSMOSIS ISOLATION ON REACTIVITY OF NATURALLY OCCURRING DISSOLVED ORGANIC MATTER IN PHYSICOCHEMICAL PROCESSES. (R828045)

EPA Science Inventory

A field reverse osmosis system was used to isolate dissolved organic matter (DOM) from two lacustrine and two riverine surface water sources. The rejection of DOM was on the order of 99% and did not vary significantly with pressure. A simple mass balance model using a single m...

Cryogenic temperature effects on sting-balance deflections in the National Transonic Facility

NASA Technical Reports Server (NTRS)

Popernack, Thomas G., Jr.; Adcock, Jerry B.

1990-01-01

An investigation was conducted at the National Transonic Facility (NTF) to document the change in sting-balance deflections from ambient to cryogenic temperatures. Space limitations in some NTF models do not allow the use of on-board angle of attack instrumentation. In order to obtain angle of attack data, pre-determined sting-balance bending data must be combined with arc sector angle measurements. Presently, obtaining pretest sting-balance data requires several cryogenic cycles and cold loadings over a period of several days. A method of reducing the calibration time required is to obtain only ambient temperature sting-balance bending data and correct for changes in material properties at cryogenic temperatures. To validate this method, two typical NTF sting-balance combinations were tested. The test results show excellent agreement with the predicted values and the repeatability of the data was 0.01 degree.

Methods for developing time-series climate surfaces to drive topographically distributed energy- and water-balance models

USGS Publications Warehouse

Susong, D.; Marks, D.; Garen, D.

1999-01-01

Topographically distributed energy- and water-balance models can accurately simulate both the development and melting of a seasonal snowcover in the mountain basins. To do this they require time-series climate surfaces of air temperature, humidity, wind speed, precipitation, and solar and thermal radiation. If data are available, these parameters can be adequately estimated at time steps of one to three hours. Unfortunately, climate monitoring in mountain basins is very limited, and the full range of elevations and exposures that affect climate conditions, snow deposition, and melt is seldom sampled. Detailed time-series climate surfaces have been successfully developed using limited data and relatively simple methods. We present a synopsis of the tools and methods used to combine limited data with simple corrections for the topographic controls to generate high temporal resolution time-series images of these climate parameters. Methods used include simulations, elevational gradients, and detrended kriging. The generated climate surfaces are evaluated at points and spatially to determine if they are reasonable approximations of actual conditions. Recommendations are made for the addition of critical parameters and measurement sites into routine monitoring systems in mountain basins.Topographically distributed energy- and water-balance models can accurately simulate both the development and melting of a seasonal snowcover in the mountain basins. To do this they require time-series climate surfaces of air temperature, humidity, wind speed, precipitation, and solar and thermal radiation. If data are available, these parameters can be adequately estimated at time steps of one to three hours. Unfortunately, climate monitoring in mountain basins is very limited, and the full range of elevations and exposures that affect climate conditions, snow deposition, and melt is seldom sampled. Detailed time-series climate surfaces have been successfully developed using limited data and relatively simple methods. We present a synopsis of the tools and methods used to combine limited data with simple corrections for the topographic controls to generate high temporal resolution time-series images of these climate parameters. Methods used include simulations, elevational gradients, and detrended kriging. The generated climate surfaces are evaluated at points and spatially to determine if they are reasonable approximations of actual conditions. Recommendations are made for the addition of critical parameters and measurement sites into routine monitoring systems in mountain basins.

Process monitoring in modern safeguards applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ehinger, M.H.

1989-11-01

From the safeguards standpoint, regulatory requirements are finally moving into the modern world of communication and information processing. Gone are the days when the accountant with the green eye shade and arm bands made judgments on the material balance a month after the balance was closed. The most recent Nuclear Regulatory Commission (NRC) regulations and U.S. Department of Energy (DOE) orders have very strict standards for timeliness and sensitivity to loss or removal of material. The latest regulations recognize that plant operators have a lot of information on and control over the location and movement of material within their facilities.more » This information goes beyond that traditionally reported under accountability requirements. These new regulations allow facility operators to take credit for many of the more informal process controls.« less

Flexible rotor balancing by the influence coefficient method: Multiple critical speeds with rigid or flexible supports

NASA Technical Reports Server (NTRS)

Tessarzik, J. M.

1975-01-01

Experimental tests were conducted to demonstrate the ability of the influence coefficient method to achieve precise balance of flexible rotors of virtually any design for operation through virtually any speed range. Various practical aspects of flexible-rotor balancing were investigated. Tests were made on a laboratory quality machine having a 122 cm (48 in.) long rotor weighing 50 kg (110 lb) and covering a speed range up to 18000 rpm. The balancing method was in every instance effective, practical, and economical and permitted safe rotor operation over the full speed range covering four rotor bending critical speeds. Improved correction weight removal methods for rotor balancing were investigated. Material removal from a rotating disk was demonstrated through application of a commercially available laser.

Effect of electron count and chemical complexity in the Ta-Nb-Hf-Zr-Ti high-entropy alloy superconductor.

PubMed

von Rohr, Fabian; Winiarski, Michał J; Tao, Jing; Klimczuk, Tomasz; Cava, Robert Joseph

2016-11-15

High-entropy alloys are made from random mixtures of principal elements on simple lattices, stabilized by a high mixing entropy. The recently discovered body-centered cubic (BCC) Ta-Nb-Hf-Zr-Ti high-entropy alloy superconductor appears to display properties of both simple crystalline intermetallics and amorphous materials; e.g., it has a well-defined superconducting transition along with an exceptional robustness against disorder. Here we show that the valence electron count dependence of the superconducting transition temperature in the high-entropy alloy falls between those of analogous simple solid solutions and amorphous materials and test the effect of alloy complexity on the superconductivity. We propose high-entropy alloys as excellent intermediate systems for studying superconductivity as it evolves between crystalline and amorphous materials.

Functionalized white graphene - Copper oxide nanocomposite: Synthesis, characterization and application as catalyst for thermal decomposition of ammonium perchlorate.

PubMed

Paulose, Sanoop; Raghavan, Rajeev; George, Benny K

2017-05-15

Reactivity is of great importance for metal oxide nanoparticles (MONP) used as catalysts and advanced materials, but seeking for higher reactivity seems to be conflict with high chemical stability required for MONP. There is direct balance between reactivity and stability of these MONP. This could be acheived for metal oxide by dispersing them in a substrate. Here, we report a simple, efficient and high-yield process for the production of copper oxide (CuO) nanoparticles dispersed on a chemically inert material, few-layer hexagonal boron nitride (h-BN) with a thickness around 1.7nm and lateral dimensions mostly below 200nm. The mechano-chemical reaction which take place at atmospheric pressure and room temperature involves a urea assisted exfoliation of pristine boron nitride. Copper oxide nanoparticles dispersed on the surface of these few layered h-BN reduced its tendency for aggregation. The optimum concentration of CuO:h-BN was found to be 2:1 which shows highest catalytic activity for the thermal decomposition of ammonium perchlorate. The high catalytic activity of the in situ synthesized CuO-h-BN composite may be attributed to uniform distribution of CuO nanoparticles on the few layered h-BN which in turn provide a number of active sites on the surface due to non aggregation. Copyright © 2017 Elsevier Inc. All rights reserved.

On deriving the Maxwell stress tensor method for calculating the optical force and torque on an object in harmonic electromagnetic fields

NASA Astrophysics Data System (ADS)

Ye, Qian; Lin, Haoze

2017-07-01

Though extensively used in calculating optical force and torque acting on a material object illuminated by laser, the Maxwell stress tensor (MST) method follows the electromagnetic linear and angular momentum balance that is usually derived in most textbooks for a continuous volume charge distribution in free space, if not resorting to the application of Noether’s theorem in electrodynamics. To cast the conservation laws into a physically appealing form involving the current densities of linear and angular momentum, on which the MST method is based, the divergence theorem is employed to transform a volume integral into a surface integral. When a material object of finite volume is put into the field, it brings about a discontinuity of field across its surface, due to the presence of induced surface charge and surface current. Ambiguity arises among students in whether the divergence theorem can still be directly used without any justification. By taking into account the effect of the induced surface charge and current, we present a simple pedagogical derivation for the MST method for calculating the optical force and torque on an object immersed in monochromatic optical field, without resorting to Noether’s theorem. Although the results turn out to be identical to those given in the standard textbooks, our derivation avoids the direct use of the divergence theorem on a discontinuous function.

Reconfigurable ultra-wideband waveform generation with simple photonic devices

NASA Astrophysics Data System (ADS)

Dastmalchi, Mansour; Abtahi, Mohammad; Lemus, David; Rusch, Leslie A.; LaRochelle, Sophie

2012-08-01

We propose and experimentally demonstrate a low cost, low power consumption technique for ultra-wideband pulse shaping. Our approach is based on thermal apodization of two identical linearly chirped fiber Bragg gratings (LCFBG) placed in both arms of a balanced photodetector. Resistive heating elements with low electrical power consumption are used to tune the LCFBG spectral responses. Using a standard gain switched distributed feedback laser as a pulsed optical source and a simple energy detector receiver, we measured a bit error rate of 1.5×10-4 at a data rate of 1 Gb/s after RF transmission over a 1-m link.

A simple model describing the nonlinear dynamics of the dusk/dawn asymmetry in the high-latitude thermospheric flow

NASA Technical Reports Server (NTRS)

Gundlach, J. P.; Larsen, M. F.; Mikkelsen, I. S.

1988-01-01

A simple nonlinear, axisymmetric, shallow-water numerical model has been used to study the asymmetry in the neutral flow between the dusk and dawn sides of the auroral oval. The results indicate that the Coriolis force and the curvature terms are nearly in balance on the evening side and require only a small pressure gradient to effect adjustment. The result is smaller neutral velocities near dawn and larger velocities near dusk than would be the case for a linearized treatment. A consequence is that more gravity wave energy is produced on the morning side than on the evening side.

Design Considerations for Heavily-Doped Cryogenic Schottky Diode Varactor Multipliers

NASA Technical Reports Server (NTRS)

Schlecht, E.; Maiwald, F.; Chattopadhyay, G.; Martin, S.; Mehdi, I.

2001-01-01

Diode modeling for Schottky varactor frequency multipliers above 500 GHz is presented with special emphasis placed on simple models and fitted equations for rapid circuit design. Temperature- and doping-dependent mobility, resistivity, and avalanche current multiplication and breakdown are presented. Next is a discussion of static junction current, including the effects of tunneling as well as thermionic emission. These results have been compared to detailed measurements made down to 80 K on diodes fabricated at JPL, followed by a discussion of the effect on multiplier efficiency. Finally, a simple model of current saturation in the undepleted active layer suitable for inclusion in harmonic balance simulators is derived.

The Alliance of Advanced Process Control and Accountability – A Future Safeguards-By-Design Tool

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lumetta, Gregg J.; Bresee, James C.; Paviet, Patricia D.

For any chemical separation process producing a valuable product, a material balance is an important process control measurement. That is particularly true for the separation of actinides from irradiated nuclear fuel, not only for their intrinsic value but also because an incomplete material balance may indicate diversion for unauthorized use. The DOE Office of Nuclear Energy is currently carrying out at the Pacific Northwest National Laboratory an experimental measurement of how well and with what precision current technologies can implement near real-time actinide material balances. This measurement effort is called the CoDCon project. It involves the separation of a productmore » with a 70/30 uranium/plutonium mass ratio. Initial tests will use dissolved fuel simulants prepared with pure uranium and plutonium nitrates at the same input ratios as irradiated fuel. Subsequent testing with actual irradiated fuel would be done to verify the results obtained with simulants. The experiments will use advanced on-line instrumentation supported by dynamic process models. Since accountability uncertainties could mask diversions, the aim of the project is not only to measure present-day capabilities but also, through sensitivity analyses, to identify those measurements with the greatest potential for overall material-balance improvements. The latter results will help identify priorities for future fuel cycle R&D programs. Advanced separations process control and material accountability technologies thus have a common goal: to provide the best tools available for safeguards-by-design [defined by the International Atomic Energy Agency (IAEA) as the integration of the design of a new nuclear facility through planning, construction, operation and decommissioning]. Since the potential domestic use of CoDCon results may be later than their possible foreign applications, arrangements may be feasible for possible bilateral or multinational cooperation in the CoDCon project.« less

Salinity controls on plant transpiration and soil water balance

NASA Astrophysics Data System (ADS)

Perri, S.; Molini, A.; Suweis, S. S.; Viola, F.; Entekhabi, D.

2017-12-01

Soil salinization and aridification represent a major threat for the food security and sustainable development of drylands. The two problems are deeply connected, and their interplay is expected to be further enhanced by climate change and projected population growth. Salt-affected land is currently estimated to cover around 1.1 Gha, and is particularly widespread in semi-arid to hyper-arid climates. Over 900 Mha of these saline/sodic soils are potentially available for crop or biomass production. Salt-tolerant plants have been recently proposed as valid solution to exploit or even remediate salinized soils. However the effects of salinity on evapotranspiration, soil water balance and the long-term salt mass balance in the soil, are still largely unexplored. In this contribution we analyze the feedback of evapotranspiration on soil salinization, with particular emphasis on the role of vegetation and plant salt-tolerance. The goal is to introduce a simple modeling framework able to shed some light on how (a) soil salinity controls plant transpiration, and (b) salinization itself is favored/impeded by different vegetation feedback. We introduce at this goal a spatially lumped stochastic model of soil moisture and salt mass dynamics averaged over the active soil depth, and accounting for the effect of salinity on evapotranspiration. Here, the limiting effect of salinity on ET is modeled through a simple plant response function depending on both salt concentration in the soil and plant salt-tolerance. The coupled soil moisture and salt mass balance is hence used to obtain the conditional steady-state probability density function (pdf) of soil moisture for given salt tolerance and salinization level, Our results show that salinity imposes a limit in the soil water balance and this limit depends on plant salt-tolerance mainly through the control of the leaching occurrence (tolerant plants exploit water more efficiently than the sensitive ones). We also analyzed the effect of salt-tolerance on salt concentration patterns pointing out how vegetation imposes an upper bound to concentration of soluble salts in the soil. The long-term effects of plant salt tolerance on soil salinization are also discussed by an approximated expression for the salt mass pdf.

Laser welding of polymers: phenomenological model for a quick and reliable process quality estimation considering beam shape influences

NASA Astrophysics Data System (ADS)

Timpe, Nathalie F.; Stuch, Julia; Scholl, Marcus; Russek, Ulrich A.

2016-03-01

This contribution presents a phenomenological, analytical model for laser welding of polymers which is suited for a quick process quality estimation for the practitioner. Besides material properties of the polymer and processing parameters like welding pressure, feed rate and laser power the model is based on a simple few parameter description of the size and shape of the laser power density distribution (PDD) in the processing zone. The model allows an estimation of the weld seam tensile strength. It is based on energy balance considerations within a thin sheet with the thickness of the optical penetration depth on the surface of the absorbing welding partner. The joining process itself is modelled by a phenomenological approach. The model reproduces the experimentally known process windows for the main process parameters correctly. Using the parameters describing the shape of the laser PDD the critical dependence of the process windows on the PDD shape will be predicted and compared with experiments. The adaption of the model to other laser manufacturing processes where the PDD influence can be modelled comparably will be discussed.

Semi-empirical long-term cycle life model coupled with an electrolyte depletion function for large-format graphite/LiFePO4 lithium-ion batteries

NASA Astrophysics Data System (ADS)

Park, Joonam; Appiah, Williams Agyei; Byun, Seoungwoo; Jin, Dahee; Ryou, Myung-Hyun; Lee, Yong Min

2017-10-01

To overcome the limitation of simple empirical cycle life models based on only equivalent circuits, we attempt to couple a conventional empirical capacity loss model with Newman's porous composite electrode model, which contains both electrochemical reaction kinetics and material/charge balances. In addition, an electrolyte depletion function is newly introduced to simulate a sudden capacity drop at the end of cycling, which is frequently observed in real lithium-ion batteries (LIBs). When simulated electrochemical properties are compared with experimental data obtained with 20 Ah-level graphite/LiFePO4 LIB cells, our semi-empirical model is sufficiently accurate to predict a voltage profile having a low standard deviation of 0.0035 V, even at 5C. Additionally, our model can provide broad cycle life color maps under different c-rate and depth-of-discharge operating conditions. Thus, this semi-empirical model with an electrolyte depletion function will be a promising platform to predict long-term cycle lives of large-format LIB cells under various operating conditions.

Synthesis and click chemistry of a new class of biodegradable polylactide towards tunable thermo-responsive biomaterials.

PubMed

Zhang, Quanxuan; Ren, Hong; Baker, Gregory L

2015-02-28

A new class of clickable and biodegradable polylactide was designed and prepared via bulk polymerization of 3,6-dipropargyloxymethyl-1,4-dioxane-2,5-dione ( 1 ) which was synthesized from easily accessible propargyloxylactic acid ( 5 ). A homopolymer of 1 and random copolymer of 1 with l-lactide were obtained as amorphous materials and exhibit low T g of 8.5 and 34 °C, respectively, indicating their promising potentials for biomedical applications. The statistical nature of random copolymers was investigated by DSC analysis and 13 C NMR spectroscopy, which implies the random distribution of terminal alkyne groups along the back bone of copolymers. The efficient click post-modification of this new class of polylactide with alkyl and mPEG azides affords novel hydrophilic biomaterials, which exhibit reversible thermo-responsive properties as evidenced by their tunable LCST ranging from 22 to 69 °C depending on the balance of the incorporated hydrophilic/hydrophobic side chains. These results indicate the generality of this new class of clickable polylactide in preparing novel smart biomaterials in a simple and efficient manner via click chemistry.

Continental extension, magmatism and elevation; formal relations and rules of thumb

USGS Publications Warehouse

Lachenbruch, A.H.; Morgan, P.

1990-01-01

To investigate simplified relations between elevation and the extensional, magmatic and thermal processes that influence lithosphere buoyancy, we assume that the lithosphere floats on an asthenosphere of uniform density and has no flexural strength. A simple graph relating elevation to lithosphere density and thickness provides an overview of expectable conditions around the earth and a simple test for consistancy of continental and oceanic lithosphere models. The mass-balance relations yield simple general rules for estimating elevation changes caused by various tectonic, magmatic and thermal processes without referring to detailed models. The rules are general because they depend principally on buoyancy, which under our assumptions is specified by elevation, a known quantity; they do not generally require a knowledge of lithosphere thickness and density. The elevation of an extended terrain contains important information on its tectonic and magmatic history. In the Great Basin where Cenozoic extension is estimated to be 100%, the present high mean elevation ( ~ 1.75 km) probably requires substantial low-density magmatic contributions to the extending lithosphere. The elevation cannot be reasonably explained solely as the buoyant residue of a very high initial terrane, or of a lithosphere that was initially very thick and subsequently delaminated and heated. Even models with a high initial elevation typically call for 10 km or so of accumulated magmatic material of near-crustal density. To understand the evolution of the Great Basin, it is important to determine whether such intruded material is present; some could replenish the stretching crust by underplating and crustal intrusion and some might reside in the upper mantle. The elevation maintained or approached by an intruded extending lithosphere depends on the ratio B of how fast magma is supplied from the asthenosphere ( b km/Ma) to how fast the lithosphere spreads the magma out by extension (?? Ma-1). For a surface maintained 2 1 2km below sea level (e.g., an ocean ridge) B is about 5 km; for continental extension the ratio may be much greater. The frequent association of volcanism with continental extension, the high elevation (and buoyancy) of some appreciably extended terrains, and the oceanic spreading analog all suggest that magmatism may play an important role in continental extension. Better estimates of total extension and elevation change in extended regions can help to identify that role. ?? 1990.

Intrinsic and Extrinsic Contributions to Seated Balance in the Sagittal and Coronal Planes: Implications for Trunk Control After Spinal Cord Injury.

PubMed

Audu, Musa L; Triolo, Ronald J

2015-08-01

The contributions of intrinsic (passive) and extrinsic (active) properties of the human trunk, in terms of the simultaneous actions about the hip and spinal joints, to the control of sagittal and coronal seated balance were examined. Able-bodied (ABD) and spinal-cord-injured (SCI) volunteers sat on a moving platform which underwent small amplitude perturbations in the anterior-posterior (AP) and medial-lateral (ML) directions while changes to trunk orientation were measured. A linear parametric model that related platform movement to trunk angle was fit to the experimental data by identifying model parameters in the time domain. The results showed that spinal cord injury leads to a systematic reduction in the extrinsic characteristics, while most of the intrinsic characteristics were rarely affected. In both SCI and ABD individuals, passive characteristics alone were not enough to maintain seated balance. Passive stiffness in the ML direction was almost 3 times that in the AP direction, making more extrinsic mechanisms necessary for balance in the latter direction. Proportional and derivative terms of the extrinsic model made the largest contribution to the overall output from the active system, implying that a simple proportional plus derivative (PD) controller structure will suffice for restoring seated balance after spinal cord injury.

An improved algorithm for balanced POD through an analytic treatment of impulse response tails

NASA Astrophysics Data System (ADS)

Tu, Jonathan H.; Rowley, Clarence W.

2012-06-01

We present a modification of the balanced proper orthogonal decomposition (balanced POD) algorithm for systems with simple impulse response tails. In this new method, we use dynamic mode decomposition (DMD) to estimate the slowly decaying eigenvectors that dominate the long-time behavior of the direct and adjoint impulse responses. This is done using a new, low-memory variant of the DMD algorithm, appropriate for large datasets. We then formulate analytic expressions for the contribution of these eigenvectors to the controllability and observability Gramians. These contributions can be accounted for in the balanced POD algorithm by simply appending the impulse response snapshot matrices (direct and adjoint, respectively) with particular linear combinations of the slow eigenvectors. Aside from these additions to the snapshot matrices, the algorithm remains unchanged. By treating the tails analytically, we eliminate the need to run long impulse response simulations, lowering storage requirements and speeding up ensuing computations. To demonstrate its effectiveness, we apply this method to two examples: the linearized, complex Ginzburg-Landau equation, and the two-dimensional fluid flow past a cylinder. As expected, reduced-order models computed using an analytic tail match or exceed the accuracy of those computed using the standard balanced POD procedure, at a fraction of the cost.

Forces between permanent magnets: experiments and model

NASA Astrophysics Data System (ADS)

González, Manuel I.

2017-03-01

This work describes a very simple, low-cost experimental setup designed for measuring the force between permanent magnets. The experiment consists of placing one of the magnets on a balance, attaching the other magnet to a vertical height gauge, aligning carefully both magnets and measuring the load on the balance as a function of the gauge reading. A theoretical model is proposed to compute the force, assuming uniform magnetisation and based on laws and techniques accessible to undergraduate students. A comparison between the model and the experimental results is made, and good agreement is found at all distances investigated. In particular, it is also found that the force behaves as r -4 at large distances, as expected.

Statistical foundations of liquid-crystal theory

PubMed Central

Seguin, Brian; Fried, Eliot

2013-01-01

We develop a mechanical theory for systems of rod-like particles. Central to our approach is the assumption that the external power expenditure for any subsystem of rods is independent of the underlying frame of reference. This assumption is used to derive the basic balance laws for forces and torques. By considering inertial forces on par with other forces, these laws hold relative to any frame of reference, inertial or noninertial. Finally, we introduce a simple set of constitutive relations to govern the interactions between rods and find restrictions necessary and sufficient for these laws to be consistent with thermodynamics. Our framework provides a foundation for a statistical mechanical derivation of the macroscopic balance laws governing liquid crystals. PMID:23772091

Cyclic voltammetry modeling of proton transport effects on redox charge storage in conductive materials: application to a TiO2 mesoporous film.

PubMed

Kim, Y S; Balland, V; Limoges, B; Costentin, C

2017-07-21

Cyclic voltammetry is a particularly useful tool for characterizing charge accumulation in conductive materials. A simple model is presented to evaluate proton transport effects on charge storage in conductive materials associated with a redox process coupled with proton insertion in the bulk material from an aqueous buffered solution, a situation frequently encountered in metal oxide materials. The interplay between proton transport inside and outside the materials is described using a formulation of the problem through introduction of dimensionless variables that allows defining the minimum number of parameters governing the cyclic voltammetry response with consideration of a simple description of the system geometry. This approach is illustrated by analysis of proton insertion in a mesoporous TiO 2 film.

How protein materials balance strength, robustness, and adaptability

PubMed Central

Buehler, Markus J.; Yung, Yu Ching

2010-01-01

Proteins form the basis of a wide range of biological materials such as hair, skin, bone, spider silk, or cells, which play an important role in providing key functions to biological systems. The focus of this article is to discuss how protein materials are capable of balancing multiple, seemingly incompatible properties such as strength, robustness, and adaptability. To illustrate this, we review bottom-up materiomics studies focused on the mechanical behavior of protein materials at multiple scales, from nano to macro. We focus on alpha-helix based intermediate filament proteins as a model system to explain why the utilization of hierarchical structural features is vital to their ability to combine strength, robustness, and adaptability. Experimental studies demonstrating the activation of angiogenesis, the growth of new blood vessels, are presented as an example of how adaptability of structure in biological tissue is achieved through changes in gene expression that result in an altered material structure. We analyze the concepts in light of the universality and diversity of the structural makeup of protein materials and discuss the findings in the context of potential fundamental evolutionary principles that control their nanoscale structure. We conclude with a discussion of multiscale science in biology and de novo materials design. PMID:20676305

The influence of intraoperative soft tissue balance on patellar pressure in posterior-stabilized total knee arthroplasty.

PubMed

Matsumoto, Tomoyuki; Shibanuma, Nao; Takayama, Koji; Sasaki, Hiroshi; Ishida, Kazunari; Matsushita, Takehiko; Kuroda, Ryosuke; Kurosaka, Masahiro

2016-06-01

Appropriate soft tissue balance is essential for the success of total knee arthroplasty (TKA), and assessment with an offset-type tensor provides useful information about the femorotibial (FT) joint. The purpose of the study was to investigate the relationship between intraoperative soft tissue balance and patellar pressure at both medial and lateral sides. Thirty varus-type osteoarthritis patients who received mobile-bearing posterior-stabilized TKAs were enrolled in the study. Using the tensor, soft tissue balance, including joint component gap and varus ligament balance, was recorded at 0°, 10°, 30°, 60°, 90°, 120°, and 135° with patellofemoral (PF) joint reduction and femoral component placement. Following final prostheses implanted with appropriate insert, the medial and lateral patellar pressures were measured at each flexion angle. A simple regression analysis was performed between each patellar pressure, parameter of soft tissue balance, and postoperative flexion angle. Both lateral and medial patellar pressures increased with flexion. The lateral patellar pressure was significantly higher than the medial patellar pressure at 60°, 90°, and 135° of flexion (p<0.05). The lateral patellar pressure inversely correlated with the varus ligament balance at 60° and 90° of flexion (p<0.05). The lateral patellar pressure at 120° and 135° of flexion inversely correlated with the postoperative flexion angle (p<0.05). Soft tissue balance influenced patellar pressure. In particular, a reduced lateral patellar pressure was found at the lateral laxity at flexion, leading to high postoperative flexion angle. III. Copyright © 2016 Elsevier B.V. All rights reserved.

Method of Manufacturing a Micromechanical Oscillating Mass Balance

NASA Technical Reports Server (NTRS)

Altemir, David A. (Inventor)

1999-01-01

A micromechanical oscillating mass balance and method adapted for measuring minute quantities of material deposited at a selected location, such as during a vapor deposition process. The invention comprises a vibratory composite beam which includes a dielectric layer sandwiched between two conductive layers.The beam is positioned in a magnetic field. An alternating current passes through one conductive layers, the beam oscillates, inducing an output current in the second conductive layer, which is analyzed to determine the resonant frequency of the beam. As material is deposited on the beam, the mass of the beam increases and the resonant frequency of the beam shifts, and the mass added is determined.

Micromechanical Oscillating Mass Balance

NASA Technical Reports Server (NTRS)

Altemir, David A. (Inventor)

1997-01-01

A micromechanical oscillating mass balance and method adapted for measuring minute quantities of material deposited at a selected location, such as during a vapor deposition process. The invention comprises a vibratory composite beam which includes a dielectric layer sandwiched between two conductive layers. The beam is positioned in a magnetic field. An alternating current passes through one conductive layers, the beam oscillates, inducing an output current in the second conductive layer, which is analyzed to determine the resonant frequency of the beam. As material is deposited on the beam, the mass of the beam increases and the resonant frequency of the beam shifts, and the mass added is determined.

A Robust Damage-Reporting Strategy for Polymeric Materials Enabled by Aggregation-Induced Emission.

PubMed

Robb, Maxwell J; Li, Wenle; Gergely, Ryan C R; Matthews, Christopher C; White, Scott R; Sottos, Nancy R; Moore, Jeffrey S

2016-09-28

Microscopic damage inevitably leads to failure in polymers and composite materials, but it is difficult to detect without the aid of specialized equipment. The ability to enhance the detection of small-scale damage prior to catastrophic material failure is important for improving the safety and reliability of critical engineering components, while simultaneously reducing life cycle costs associated with regular maintenance and inspection. Here, we demonstrate a simple, robust, and sensitive fluorescence-based approach for autonomous detection of damage in polymeric materials and composites enabled by aggregation-induced emission (AIE). This simple, yet powerful system relies on a single active component, and the general mechanism delivers outstanding performance in a wide variety of materials with diverse chemical and mechanical properties.

Investigating the Feasibility and Utility of Bedside Balance Technology Acutely After Pediatric Concussion: A Pilot Study.

PubMed

Rhine, Tara D; Byczkowski, Terri L; Clark, Ross A; Babcock, Lynn

2016-05-01

To examine postural instability in children acutely after concussion, using the Wii Balance Board (WBB). We hypothesized that children with traumatic brain injury would have significantly worse balance relative to children without brain injury. Prospective case-control pilot study. Emergency department of a tertiary urban pediatric hospital. Cases were a convenience sample 11-16 years old who presented within 6 hours of sustaining concussion. Two controls, matched on gender, height, and age, were enrolled for each case that completed study procedures. Controls were children who presented for a minor complaint that was unlikely to affect balance. Not applicable. The participant's postural sway expressed as the displacement in centimeters of the center of pressure during a timed balance task. Balance testing was performed using 4 stances (single or double limb, eyes open or closed). Three of the 17 (17.6%) cases were too dizzy to complete testing. One stance, double limbs eyes open, was significantly higher in cases versus controls (85.6 vs 64.3 cm, P = 0.04). A simple test on the WBB consisting of a 2-legged standing balance task with eyes open discriminated children with concussion from non-head-injured controls. The low cost and feasibility of this device make it a potentially viable tool for assessing postural stability in children with concussion for both longitudinal research studies and clinical care. These pilot data suggest that the WBB is an inexpensive tool that can be used on the sideline or in the outpatient setting to objectively identify and quantify postural instability.

Water balance of a lake with floodplain buffering: Lake Tana, Blue Nile Basin, Ethiopia

NASA Astrophysics Data System (ADS)

Dessie, Mekete; Verhoest, Niko E. C.; Pauwels, Valentijn R. N.; Adgo, Enyew; Deckers, Jozef; Poesen, Jean; Nyssen, Jan

2015-03-01

Lakes are very important components of the earth's hydrological cycle, providing a variety of services for humans and ecosystem functioning. For a sustainable use of lakes, a substantial body of knowledge on their water balance is vital. We present here a detailed daily water balance analysis for Lake Tana, the largest lake in Ethiopia and the source of the Blue Nile. Rainfall on the lake is determined by Thiessen polygon procedure, open water evaporation is estimated by the Penman-combination equation and observed inflows for the gauged catchments as well as outflow data at the two lake outlets are directly used. Runoff from ungauged catchments is estimated using a simple rainfall-runoff model and runoff coefficients. Hillslope catchments and floodplains are treated separately, which makes this study unique compared to previous water balance studies. Impact of the floodplain on the lake water balance is analyzed by conducting scenario-based studies. We found an average yearly abstraction of 420 × 106 m3 or 6% of river inflows to the lake by the floodplain in 2012 and 2013. Nearly 60% of the inflow to the lake is from the Gilgel Abay River. Simulated lake levels compare well with the observed lake levels (R2 = 0.95) and the water balance can be closed with a closure error of 82 mm/year (3.5% of the total lake inflow). This study demonstrates the importance of floodplains and their influence on the water balance of the lake and the need of incorporating the effects of floodplains and water abstraction for irrigation to improve predictions.

Calibrating a surface mass-balance model for Austfonna ice cap, Svalbard

NASA Astrophysics Data System (ADS)

Schuler, Thomas Vikhamar; Loe, Even; Taurisano, Andrea; Eiken, Trond; Hagen, Jon Ove; Kohler, Jack

2007-10-01

Austfonna (8120 km2) is by far the largest ice mass in the Svalbard archipelago. There is considerable uncertainty about its current state of balance and its possible response to climate change. Over the 2004/05 period, we collected continuous meteorological data series from the ice cap, performed mass-balance measurements using a network of stakes distributed across the ice cap and mapped the distribution of snow accumulation using ground-penetrating radar along several profile lines. These data are used to drive and test a model of the surface mass balance. The spatial accumulation pattern was derived from the snow depth profiles using regression techniques, and ablation was calculated using a temperature-index approach. Model parameters were calibrated using the available field data. Parameter calibration was complicated by the fact that different parameter combinations yield equally acceptable matches to the stake data while the resulting calculated net mass balance differs considerably. Testing model results against multiple criteria is an efficient method to cope with non-uniqueness. In doing so, a range of different data and observations was compared to several different aspects of the model results. We find a systematic underestimation of net balance for parameter combinations that predict observed ice ablation, which suggests that refreezing processes play an important role. To represent these effects in the model, a simple PMAX approach was included in its formulation. Used as a diagnostic tool, the model suggests that the surface mass balance for the period 29 April 2004 to 23 April 2005 was negative (-318 mm w.e.).

A coupled chemo-thermo-hygro-mechanical model of concrete at high temperature and failure analysis

NASA Astrophysics Data System (ADS)

Li, Xikui; Li, Rongtao; Schrefler, B. A.

2006-06-01

A hierarchical mathematical model for analyses of coupled chemo-thermo-hygro-mechanical behaviour in concretes at high temperature is presented. The concretes are modelled as unsaturated deforming reactive porous media filled with two immiscible pore fluids, i.e. the gas mixture and the liquid mixture, in immiscible-miscible levels. The thermo-induced desalination process is particularly integrated into the model. The chemical effects of both the desalination and the dehydration processes on the material damage and the degradation of the material strength are taken into account. The mathematical model consists of a set of coupled, partial differential equations governing the mass balance of the dry air, the mass balance of the water species, the mass balance of the matrix components dissolved in the liquid phases, the enthalpy (energy) balance and momentum balance of the whole medium mixture. The governing equations, the state equations for the model and the constitutive laws used in the model are given. A mixed weak form for the finite element solution procedure is formulated for the numerical simulation of chemo-thermo-hygro-mechanical behaviours. Special considerations are given to spatial discretization of hyperbolic equation with non-self-adjoint operator nature. Numerical results demonstrate the performance and the effectiveness of the proposed model and its numerical procedure in reproducing coupled chemo-thermo-hygro-mechanical behaviour in concretes subjected to fire and thermal radiation.

Effect of electron count and chemical complexity in the Ta-Nb-Hf-Zr-Ti high-entropy alloy superconductor

DOE Office of Scientific and Technical Information (OSTI.GOV)

von Rohr, Fabian; Winiarski, Michał J.; Tao, Jing

High-entropy alloys are made from random mixtures of principal elements on simple lattices, stabilized by a high mixing entropy. The recently discovered body-centered cubic (BCC) Ta-Nb-Hf-Zr-Ti high-entropy alloy superconductor appears to display properties of both simple crystalline intermetallics and amorphous materials; e.g., it has a well-defined superconducting transition along with an exceptional robustness against disorder. Here we show that the valence electron count dependence of the superconducting transition temperature in the high-entropy alloy falls between those of analogous simple solid solutions and amorphous materials and test the effect of alloy complexity on the superconductivity. We propose high-entropy alloys as excellentmore » intermediate systems for studying superconductivity as it evolves between crystalline and amorphous materials.« less

Effect of electron count and chemical complexity in the Ta-Nb-Hf-Zr-Ti high-entropy alloy superconductor

PubMed Central

von Rohr, Fabian; Winiarski, Michał J.; Tao, Jing; Klimczuk, Tomasz; Cava, Robert Joseph

2016-01-01

High-entropy alloys are made from random mixtures of principal elements on simple lattices, stabilized by a high mixing entropy. The recently discovered body-centered cubic (BCC) Ta-Nb-Hf-Zr-Ti high-entropy alloy superconductor appears to display properties of both simple crystalline intermetallics and amorphous materials; e.g., it has a well-defined superconducting transition along with an exceptional robustness against disorder. Here we show that the valence electron count dependence of the superconducting transition temperature in the high-entropy alloy falls between those of analogous simple solid solutions and amorphous materials and test the effect of alloy complexity on the superconductivity. We propose high-entropy alloys as excellent intermediate systems for studying superconductivity as it evolves between crystalline and amorphous materials. PMID:27803330

Effect of electron count and chemical complexity in the Ta-Nb-Hf-Zr-Ti high-entropy alloy superconductor

DOE PAGES

von Rohr, Fabian; Winiarski, Michał J.; Tao, Jing; ...

2016-11-01

High-entropy alloys are made from random mixtures of principal elements on simple lattices, stabilized by a high mixing entropy. The recently discovered body-centered cubic (BCC) Ta-Nb-Hf-Zr-Ti high-entropy alloy superconductor appears to display properties of both simple crystalline intermetallics and amorphous materials; e.g., it has a well-defined superconducting transition along with an exceptional robustness against disorder. Here we show that the valence electron count dependence of the superconducting transition temperature in the high-entropy alloy falls between those of analogous simple solid solutions and amorphous materials and test the effect of alloy complexity on the superconductivity. We propose high-entropy alloys as excellentmore » intermediate systems for studying superconductivity as it evolves between crystalline and amorphous materials.« less

Construction of flexible metal-organic framework (MOF) papers through MOF growth on filter paper and their selective dye capture.

PubMed

Park, Jeehyun; Oh, Moonhyun

2017-09-14

The conjugation of metal-organic frameworks (MOFs) with other materials is an excellent strategy for the production of advanced materials having desired properties and so appropriate applicability. In particular, the integration of MOFs with a flexible paper is expected to form valuable materials in separation technology. Here we report a simple method for the generation of MOF papers through the compact and uniform growth of MOF nanoparticles on the cellulose surface of a carboxymethylated filter paper. The resulting MOF papers show a selective capture ability for negatively charged organic dyes and they can be used for dye separation through simple filtration of a dye solution on the MOF papers. In addition, MOF papers can be reused after a simple washing process without losing their effective dye capture ability.

Forming heterojunctions at the nanoscale for improved photoelectrochemical water splitting by semiconductor materials: case studies on hematite.

PubMed

Mayer, Matthew T; Lin, Yongjing; Yuan, Guangbi; Wang, Dunwei

2013-07-16

In order for the future energy needs of humanity to be adequately and sustainably met, alternative energy techniques such as artificial photosynthesis need to be made more efficient and therefore commercially viable. On a grand scale, the energies coming to and leaving from the earth are balanced. With the fast increasing waste heat produced by human activities, the balance may be shifted to threaten the ecosystem in which we reside. To avoid such dire consequences, it is necessary to power human activities using energy derived from the incoming source, which is predominantly solar irradiation. Indeed, most life on the surface of the earth is supported, directly or indirectly, by photosynthesis that harvests solar energy and stores it in chemical bonds for redistribution. Being able to mimic the process and perform it at high efficiencies using low-cost materials has significant implications. Such an understanding is a major intellectual driving force that motivates research by us and many others. From a thermodynamic perspective, the key energy conversion step in natural photosynthesis happens in the light reactions, where H₂O splits to give O₂ and reactive protons. The capability of carrying out direct sunlight-driven water splitting with high efficiency is therefore fundamentally important. We are particularly interested in doing so using inorganic semiconductor materials because they offer the promise of durability and low cost. In this Account, we share our recent efforts in bringing semiconductor-based water splitting reactions closer to reality. More specifically, we focus on earth-abundant oxide semiconductors such as Fe₂O₃ and work on improving the performance of these materials as photoelectrodes for photoelectrochemical reactions. Using hematite (α-Fe₂O₃) as an example, we examine how the main problems that limit the performance, namely, the short hole collection distance, poor light absorption near the band edge, and mismatch of the band edge energetics with those of water redox reactions, can in principle be addressed by adding nanoscale charge collectors, forming buried junctions, and including additional light absorbers. These results highlight the power of forming homo- or heterojunctions at the nanoscale, which permits us to engineer the band structures of semiconductors to the specific application of water splitting. The key enabling factor is our ability to synthesize materials with precise control over the dimensions, crystallinity, and, most importantly, the interface quality at the nanoscale. While being able to tailor specific properties on a simple, earth-abundant device is not straightforward, the approaches we report here take significant steps towards efficient artificial photosynthesis, an energy harvesting technique necessary for the well-being of humanity.

Motor Performance of Women as a Function of Age and Physical Activity Level.

ERIC Educational Resources Information Center

Rikli, Roberta; Busch, Sharman

Two studies compared motor skills of women in terms of the influence of age and activity level. In the first study, simple and choice reaction time, balance, flexibility, and grip strength of older active women were compared with that of older inactive women, and active and inactive younger women. Except for grip strength, scores of older active…

A Learning Center on the Lever for Young Children.

ERIC Educational Resources Information Center

Keislar, Evan R.; Luckenbill, Maryann

This document describes a project designed to explore the possibilities of children's learning in mechanics. The principle of the lever, one example of a simple machine, was used in the form of a balance toy. The apparatus was set up as a game in a specially devised learning center. The children made non-verbal predictions as to which way the bar…

Mixing Hot and Cold Water Streams at a T-Junction

ERIC Educational Resources Information Center

Sharp, David; Zhang, Mingqian; Xu, Zhenghe; Ryan, Jim; Wanke, Sieghard; Afacan, Artin

2008-01-01

A simple mixing of a hot- and cold-water stream at a T-junction was investigated. The main objective was to use mass and energy balance equations to predict mass low rates and the temperature of the mixed stream after the T-junction, and then compare these with the measured values. Furthermore, the thermocouple location after the T-junction and…

Modeling of breath methane concentration profiles during exercise on an ergometer*

PubMed Central

Szabó, Anna; Unterkofler, Karl; Mochalski, Pawel; Jandacka, Martin; Ruzsanyi, Vera; Szabó, Gábor; Mohácsi, Árpád; Teschl, Susanne; Teschl, Gerald; King, Julian

2016-01-01

We develop a simple three compartment model based on mass balance equations which quantitatively describes the dynamics of breath methane concentration profiles during exercise on an ergometer. With the help of this model it is possible to estimate the endogenous production rate of methane in the large intestine by measuring breath gas concentrations of methane. PMID:26828421

Balancing the Equation. Supply and Demand in Tomorrow's School Choice Marketplaces

ERIC Educational Resources Information Center

McShane, Michael Q.

2015-01-01

School choice is an education reform premised on a simple proposition: give families more choices, and they will find schools that best fit their children's needs. In short, school choice aims to create a marketplace of schooling options. School choice programs will succeed or fail based on how well they are able to create this marketplace and how…

Finding the Density of Objects without Measuring Mass and Volume

ERIC Educational Resources Information Center

Mumba, Frackson; Tsige, Mesfin

2007-01-01

A simple method based on the moment of forces and Archimedes' principle is described for finding density without measuring the mass and volume of an object. The method involves balancing two unknown objects of masses M[subscript 1] and M[subscript 2] on each side of a pivot on a metre rule and measuring their corresponding moment arms. The object…

Getting the Horse to Drink.

PubMed

Patterson, Jerry

2016-01-01

Most employers understand the frustration of seeing their employees pass up retirement savings opportunities. This article reviews the problem of insufficient retirement savings and describes simple plan design features that can make it easier for employees to do what's best for their financial futures. The author provides a case example showing what impact such changes can have on participation, deferral rates and account balances.

A simple, mass balance model of carbon flow in a controlled ecological life support system

NASA Technical Reports Server (NTRS)

Garland, Jay L.

1989-01-01

Internal cycling of chemical elements is a fundamental aspect of a Controlled Ecological Life Support System (CELSS). Mathematical models are useful tools for evaluating fluxes and reservoirs of elements associated with potential CELSS configurations. A simple mass balance model of carbon flow in CELSS was developed based on data from the CELSS Breadboard project at Kennedy Space Center. All carbon reservoirs and fluxes were calculated based on steady state conditions and modelled using linear, donor-controlled transfer coefficients. The linear expression of photosynthetic flux was replaced with Michaelis-Menten kinetics based on dynamical analysis of the model which found that the latter produced more adequate model output. Sensitivity analysis of the model indicated that accurate determination of the maximum rate of gross primary production is critical to the development of an accurate model of carbon flow. Atmospheric carbon dioxide was particularly sensitive to changes in photosynthetic rate. The small reservoir of CO2 relative to large CO2 fluxes increases the potential for volatility in CO2 concentration. Feedback control mechanisms regulating CO2 concentration will probably be necessary in a CELSS to reduce this system instability.

Development of motor speed and associated movements from 5 to 18 years.

PubMed

Gasser, Theo; Rousson, Valentin; Caflisch, Jon; Jenni, Oskar G

2010-03-01

To study the development of motor speed and associated movements in participants aged 5 to 18 years for age, sex, and laterality. Ten motor tasks of the Zurich Neuromotor Assessment (repetitive and alternating movements of hands and feet, repetitive and sequential finger movements, the pegboard, static and dynamic balance, diadochokinesis) were administered to 593 right-handed participants (286 males, 307 females). A strong improvement with age was observed in motor speed from age 5 to 10, followed by a levelling-off between 12 and 18 years. Simple tasks and the pegboard matured early and complex tasks later. Simple tasks showed no associated movements beyond early childhood; in complex tasks associated movements persisted until early adulthood. The two sexes differed only marginally in speed, but markedly in associated movements. A significant laterality (p<0.001) in speed was found for all tasks except for static balance; the pegboard was most lateralized, and sequential finger movements least. Associated movements were lateralized only for a few complex tasks. We also noted a substantial interindividual variability. Motor speed and associated movements improve strongly in childhood, weakly in adolescence, and are both of developmental relevance. Because they correlate weakly, they provide complementary information.

mGrid: A load-balanced distributed computing environment for the remote execution of the user-defined Matlab code

PubMed Central

Karpievitch, Yuliya V; Almeida, Jonas S

2006-01-01

Background Matlab, a powerful and productive language that allows for rapid prototyping, modeling and simulation, is widely used in computational biology. Modeling and simulation of large biological systems often require more computational resources then are available on a single computer. Existing distributed computing environments like the Distributed Computing Toolbox, MatlabMPI, Matlab*G and others allow for the remote (and possibly parallel) execution of Matlab commands with varying support for features like an easy-to-use application programming interface, load-balanced utilization of resources, extensibility over the wide area network, and minimal system administration skill requirements. However, all of these environments require some level of access to participating machines to manually distribute the user-defined libraries that the remote call may invoke. Results mGrid augments the usual process distribution seen in other similar distributed systems by adding facilities for user code distribution. mGrid's client-side interface is an easy-to-use native Matlab toolbox that transparently executes user-defined code on remote machines (i.e. the user is unaware that the code is executing somewhere else). Run-time variables are automatically packed and distributed with the user-defined code and automated load-balancing of remote resources enables smooth concurrent execution. mGrid is an open source environment. Apart from the programming language itself, all other components are also open source, freely available tools: light-weight PHP scripts and the Apache web server. Conclusion Transparent, load-balanced distribution of user-defined Matlab toolboxes and rapid prototyping of many simple parallel applications can now be done with a single easy-to-use Matlab command. Because mGrid utilizes only Matlab, light-weight PHP scripts and the Apache web server, installation and configuration are very simple. Moreover, the web-based infrastructure of mGrid allows for it to be easily extensible over the Internet. PMID:16539707

Computer simulation of flagellar movement. VI. Simple curvature-controlled models are incompletely specified.

PubMed

Brokaw, C J

1985-10-01

Computer simulation is used to examine a simple flagellar model that will initiate and propagate bending waves in the absence of viscous resistances. The model contains only an elastic bending resistance and an active sliding mechanism that generates reduced active shear moment with increasing sliding velocity. Oscillation results from a distributed control mechanism that reverses the direction of operation of the active sliding mechanism when the curvature reaches critical magnitudes in either direction. Bend propagation by curvature-controlled flagellar models therefore does not require interaction with the viscous resistance of an external fluid. An analytical examination of moment balance during bend propagation by this model yields a solution curve giving values of frequency and wavelength that satisfy the moment balance equation and give uniform bend propagation, suggesting that the model is underdetermined. At 0 viscosity, the boundary condition of 0 shear rate at the basal end of the flagellum during the development of new bends selects the particular solution that is obtained by computer simulations. Therefore, the details of the pattern of bend initiation at the basal end of a flagellum can be of major significance in determining the properties of propagated bending waves in the distal portion of a flagellum. At high values of external viscosity, the model oscillates at frequencies and wavelengths that give approximately integral numbers of waves on the flagellum. These operating points are selected because they facilitate the balance of bending moments at the ends of the model, where the external viscous moment approaches 0. These mode preferences can be overridden by forcing the model to operate at a predetermined frequency. The strong mode preferences shown by curvature-controlled flagellar models, in contrast to the weak or absent mode preferences shown by real flagella, therefore do not demonstrate the inapplicability of the moment-balance approach to real flagella. Instead, they indicate a need to specify additional properties of real flagella that are responsible for selecting particular operating points.

mGrid: a load-balanced distributed computing environment for the remote execution of the user-defined Matlab code.

PubMed

Karpievitch, Yuliya V; Almeida, Jonas S

2006-03-15

Matlab, a powerful and productive language that allows for rapid prototyping, modeling and simulation, is widely used in computational biology. Modeling and simulation of large biological systems often require more computational resources then are available on a single computer. Existing distributed computing environments like the Distributed Computing Toolbox, MatlabMPI, Matlab*G and others allow for the remote (and possibly parallel) execution of Matlab commands with varying support for features like an easy-to-use application programming interface, load-balanced utilization of resources, extensibility over the wide area network, and minimal system administration skill requirements. However, all of these environments require some level of access to participating machines to manually distribute the user-defined libraries that the remote call may invoke. mGrid augments the usual process distribution seen in other similar distributed systems by adding facilities for user code distribution. mGrid's client-side interface is an easy-to-use native Matlab toolbox that transparently executes user-defined code on remote machines (i.e. the user is unaware that the code is executing somewhere else). Run-time variables are automatically packed and distributed with the user-defined code and automated load-balancing of remote resources enables smooth concurrent execution. mGrid is an open source environment. Apart from the programming language itself, all other components are also open source, freely available tools: light-weight PHP scripts and the Apache web server. Transparent, load-balanced distribution of user-defined Matlab toolboxes and rapid prototyping of many simple parallel applications can now be done with a single easy-to-use Matlab command. Because mGrid utilizes only Matlab, light-weight PHP scripts and the Apache web server, installation and configuration are very simple. Moreover, the web-based infrastructure of mGrid allows for it to be easily extensible over the Internet.

Recommended Strain Gage Application Procedures for Various Langley Research Center Balances and Test Articles

NASA Technical Reports Server (NTRS)

Moore, Thomas C., Sr.

1997-01-01

The NASA Langley Research Center uses more than 10000 strain gages per year in supporting its various research programs. The character of the testing at LaRC is such that the types of strain gage installations, the materials they are applied to, and the test environments encountered, require many varied approaches for installing strain gages. These installations must be accomplished in the most technically discerning and appropriate manner. This technical memorandum is offered as an assisting guide in helping the strain gage user to determine the appropriate approach for a given strain gage application requirement. Specifically, this document offers detailed recommendations for strain gaging the following: LaRC-Designed balances, LARC custom transducers, certain composite materials and alloys, high-temperature test articles, and selected non-typical or unique materials or test conditions.

Measuring the Coefficient of Restitution and More: A Simple Experiment to Promote Students' Critical Thinking and Autonomous Work

ERIC Educational Resources Information Center

González, Manuel Á.; González, Miguel Á.; Vegas, Jesús; Llamas, César

2017-01-01

A simple experiment on the determination of the coefficient of restitution of different materials is taken as the basis of an extendable work that can be done by students in an autonomous way. On the whole, the work described in this paper would involve concepts of kinematics, materials science, air drag and buoyancy, and would help students to…

Balanced complex chromosome rearrangements: reproductive aspects. A review.

PubMed

Madan, Kamlesh

2012-04-01

This review examines the reproductive consequences for carriers of a balanced complex chromosome rearrangement (CCR). It is based on an analysis of CCRs in 103 adults referred for reproductive problems, including male infertility. The main focus is on reproductive risks based on data from 84 CCRs. Carriers of balanced CCRs have a high risk of an abortion and/or a chromosomally unbalanced child. I have identified roughly four different types of CCRs (I-IV); most (44%) belong to Type I with a simple 3-way or 4-way exchange of segments and risk factors similar to those for reciprocal translocations. There were only three CCRs (4%) of type II, which involve an inversion. Type III CCRs (21%) involve one or more insertions with ∼35% risk of a child with a duplication or a deletion of the inserted segment. Type IV CCRs (31%) involve a "middle segment" in a derivative chromosome with segments from at least three chromosomes. In ∼35% of these CCRs, recombination occurs in this segment, which can produce imbalance but in many cases it changes a CCR into a simpler balanced rearrangement in the next generation. Balanced CCRs, which have been often considered together in one group, can now be split into four types, each with a risk of a different type of imbalance. This analysis provides a better understanding of the reproductive consequences for carriers of balanced CCRs and should be useful in prenatal diagnosis and genetic counseling. Copyright © 2012 Wiley Periodicals, Inc.

Mountain glaciers vs Ice sheet in Greenland - learning from a new monitoring site in West Greenland

NASA Astrophysics Data System (ADS)

Abermann, Jakob; van As, Dirk; Wacker, Stefan; Langley, Kirsty

2017-04-01

Only 5 out of the 20.000 peripheral glaciers and ice caps surrounding Greenland are currently monitored due to logistical challenges and despite their significance for sea level rise. Large spatial coast-to-icesheet mass and energy balance gradients limit simple upscaling methods from ice-sheet observations, which builds the motivation for this study. We present results from a new mass and energy balance time series at Qasigiannguit glacier (64°09'N; 51°21'W) in Southwest Greenland. Inter-annual variability is discussed and the surface energy balance over two summers is quantified and a ranking of the main drivers performed. We find that short-wave net radiation is by far the most dominant energy source during summer, followed by similar amounts of net longwave radiation and sensible heat, respectively. We then relate these observations to synchronous measurements at similar latitude on an outlet glacier of the ice sheet a mere 100 km away. We find very pronounced horizontal surface mass balance gradients, with generally more positive values closer to the coast. We conclude that despite minor differences of atmospheric parameters (i.e. humidity, radiation, and temperature) the main reason for the strongly different signal is a pronounced winter precipitation gradient that translates in a different duration of ice exposure and through that an albedo gradient. Modelled energy balance gradients converted into mass changes show good agreement to measured surface mass balance gradients and we explore a latitudinal signal of these findings.

Biomechanical influences on balance recovery by stepping.

PubMed

Hsiao, E T; Robinovitch, S N

1999-10-01

Stepping represents a common means for balance recovery after a perturbation to upright posture. Yet little is known regarding the biomechanical factors which determine whether a step succeeds in preventing a fall. In the present study, we developed a simple pendulum-spring model of balance recovery by stepping, and used this to assess how step length and step contact time influence the effort (leg contact force) and feasibility of balance recovery by stepping. We then compared model predictions of step characteristics which minimize leg contact force to experimentally observed values over a range of perturbation strengths. At all perturbation levels, experimentally observed step execution times were higher than optimal, and step lengths were smaller than optimal. However, the predicted increase in leg contact force associated with these deviations was substantial only for large perturbations. Furthermore, increases in the strength of the perturbation caused subjects to take larger, quicker steps, which reduced their predicted leg contact force. We interpret these data to reflect young subjects' desire to minimize recovery effort, subject to neuromuscular constraints on step execution time and step length. Finally, our model predicts that successful balance recovery by stepping is governed by a coupling between step length, step execution time, and leg strength, so that the feasibility of balance recovery decreases unless declines in one capacity are offset by enhancements in the others. This suggests that one's risk for falls may be affected more by small but diffuse neuromuscular impairments than by larger impairment in a single motor capacity.

Effects of Ramadan Gasting on Postural Balance and Attentional Capacities in Elderly People.

PubMed

Laatar, R; Borji, R; Baccouch, R; Zahaf, F; Rebai, H; Sahli, S

2016-01-01

To evaluate the effects of Ramadan fasting on postural balance and attentional capacities in older adults. the Neurophysiology department of a University Hospital. Fifteen males aged between 65 and 80 years were asked to perform a postural balance protocol and a simple reaction time (SRT) test in four testing phases: one week before Ramadan (BR), during the second (SWR) and the fourth week of Ramadan (FWR) and 3 weeks after Ramadan (AR). Postural balance measurements were recorded in the bipedal stance in four different conditions: firm surface/eyes open (EO), firm surface/eyes closed (EC), foam surface/EO and foam surface/EC using a force platform. Results of the present study demonstrated that center of pressure (CoP) mean velocity (CoPVm), medio-lateral length (CoPLX) and antero-posterior length (CoPLY) were significantly higher during the SWR than BR. Likewise, values of CoPVm and CoPLX increased significantly during the FWR compared to BR. The CoPLX decreased significantly in the FWR compared to the SWR. Values of CoPVm and CoPLX were significantly higher AR in comparison with BR. In addition, SRT values increased significantly during the SWR and the FWR than BR. Ramadan fasting affects postural balance and attentional capacities in the elderly mainly in the SWR and it may, therefore, increase the risk of fall and fall-related injuries. More than three weeks are needed for older adults to recover postural balance impairment due to Ramadan fasting.

Analysis of Publically Available Skin Sensitization Data from REACH Registrations 2008–2014

PubMed Central

Luechtefeld, Thomas; Maertens, Alexandra; Russo, Daniel P.; Rovida, Costanza; Zhu, Hao; Hartung, Thomas

2017-01-01

Summary The public data on skin sensitization from REACH registrations already included 19,111 studies on skin sensitization in December 2014, making it the largest repository of such data so far (1,470 substances with mouse LLNA, 2,787 with GPMT, 762 with both in vivo and in vitro and 139 with only in vitro data). 21% were classified as sensitizers. The extracted skin sensitization data was analyzed to identify relationships in skin sensitization guidelines, visualize structural relationships of sensitizers, and build models to predict sensitization. A chemical with molecular weight > 500 Da is generally considered non-sensitizing owing to low bioavailability, but 49 sensitizing chemicals with a molecular weight > 500 Da were found. A chemical similarity map was produced using PubChem’s 2D Tanimoto similarity metric and Gephi force layout visualization. Nine clusters of chemicals were identified by Blondel’s module recognition algorithm revealing wide module-dependent variation. Approximately 31% of mapped chemicals are Michael’s acceptors but alone this does not imply skin sensitization. A simple sensitization model using molecular weight and five ToxTree structural alerts showed a balanced accuracy of 65.8% (specificity 80.4%, sensitivity 51.4%), demonstrating that structural alerts have information value. A simple variant of k-nearest neighbors outperformed the ToxTree approach even at 75% similarity threshold (82% balanced accuracy at 0.95 threshold). At higher thresholds, the balanced accuracy increased. Lower similarity thresholds decrease sensitivity faster than specificity. This analysis scopes the landscape of chemical skin sensitization, demonstrating the value of large public datasets for health hazard prediction. PMID:26863411

Development of high-speed balancing technology

NASA Technical Reports Server (NTRS)

Demuth, R.; Zorzi, E.

1981-01-01

An investigation into laser material removal showed that laser burns act in a manner typical of mechanical stress raisers causing a reduction in fatigue strength; the fatigue strength is lowered relative to the smooth specimen fatigue strength. Laser-burn zones were studied for four materials: Alloy Steel 4340, Stainless Steel 17-4 PH, Inconel 718, and Aluminum Alloy 6061-T6. Calculations were made of stress concentration factors K, for laser-burn grooves of each material type. A comparison was then made to experimentally determine the fatigue strength reduction factor. These calculations and comparisons indicated that, except for the 17-4 PH material, good agreement (a ratio of close to 1.0) existed between Kt and Kf. The performance of the 17-4 PH material has been attributed to early crack initiation due to the lower fatigue resistance of the soft, unaged laser-affected zone. Also covered in this report is the development, implementation, and testing of an influence coefficient approach to balancing a long, slender shaft under applied-torque conditions. Excellent correlation existed between the analytically predicted results and those data obtained from testing.

A Simple, Analytical Model of Collisionless Magnetic Reconnection in a Pair Plasma

NASA Technical Reports Server (NTRS)

Hesse, Michael; Zenitani, Seiji; Kuznetova, Masha; Klimas, Alex

2011-01-01

A set of conservation equations is utilized to derive balance equations in the reconnection diffusion region of a symmetric pair plasma. The reconnection electric field is assumed to have the function to maintain the current density in the diffusion region, and to impart thermal energy to the plasma by means of quasi-viscous dissipation. Using these assumptions it is possible to derive a simple set of equations for diffusion region parameters in dependence on inflow conditions and on plasma compressibility. These equations are solved by means of a simple, iterative, procedure. The solutions show expected features such as dominance of enthalpy flux in the reconnection outflow, as well as combination of adiabatic and quasi-viscous heating. Furthermore, the model predicts a maximum reconnection electric field of E(sup *)=0.4, normalized to the parameters at the inflow edge of the diffusion region.

Simple model of hydrophobic hydration.

PubMed

Lukšič, Miha; Urbic, Tomaz; Hribar-Lee, Barbara; Dill, Ken A

2012-05-31

Water is an unusual liquid in its solvation properties. Here, we model the process of transferring a nonpolar solute into water. Our goal was to capture the physical balance between water's hydrogen bonding and van der Waals interactions in a model that is simple enough to be nearly analytical and not heavily computational. We develop a 2-dimensional Mercedes-Benz-like model of water with which we compute the free energy, enthalpy, entropy, and the heat capacity of transfer as a function of temperature, pressure, and solute size. As validation, we find that this model gives the same trends as Monte Carlo simulations of the underlying 2D model and gives qualitative agreement with experiments. The advantages of this model are that it gives simple insights and that computational time is negligible. It may provide a useful starting point for developing more efficient and more realistic 3D models of aqueous solvation.

A simple, analytical model of collisionless magnetic reconnection in a pair plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hesse, Michael; Zenitani, Seiji; Kuznetsova, Masha

2009-10-15

A set of conservation equations is utilized to derive balance equations in the reconnection diffusion region of a symmetric pair plasma. The reconnection electric field is assumed to have the function to maintain the current density in the diffusion region and to impart thermal energy to the plasma by means of quasiviscous dissipation. Using these assumptions it is possible to derive a simple set of equations for diffusion region parameters in dependence on inflow conditions and on plasma compressibility. These equations are solved by means of a simple, iterative procedure. The solutions show expected features such as dominance of enthalpymore » flux in the reconnection outflow, as well as combination of adiabatic and quasiviscous heating. Furthermore, the model predicts a maximum reconnection electric field of E{sup *}=0.4, normalized to the parameters at the inflow edge of the diffusion region.« less

MEASUREMENT OF VOCS DESORBED FROM BUILDING MATERIALS--A HIGH TEMPERATURE DYNAMIC CHAMBER METHOD

EPA Science Inventory

Mass balance is a commonly used approach for characterizing the source and sink behavior of building materials. Because the traditional sink test methods evaluate the adsorption and desorption of volatile organic compounds (VOC) at ambient temperatures, the desorption process is...

PEM fuel cell stack heat and mass management

NASA Technical Reports Server (NTRS)

Vanderborgh, Nicholas E.; Kimble, Michael C.; Huff, James R.; Hedstrom, James C.

1992-01-01

PEM stacks are under evaluation as candidates for future space power technology. Results of long-term operation on a set of contemporary stacks fitted with different proton exchange membrane materials are given. Data on water balances show effects of membrane materials on stack performance.

Development of Experience-based Visible-type Electromagnetic Teaching Materials

NASA Astrophysics Data System (ADS)

Suzuki, Masayoshi; Shima, Kenzou

Electromagnetism is the base of electrical engineering, however, it is one of the most difficult subjects to learn. The small experiments which show the principles of electricity visibly are useful technique to promote these comprehension. For classroom experimental materials to learn basic electromagnetism, we developed rotating magnetic field visualizer, gravity-use generators, simple motors, and electric-field visualizer. We report how we visualized the principles of motors and generators in classroom experiments. In particular, we discuss in detail how to visualize the mechanism of very simple motors. We have been demonstrating the motors in children science classes conducted all over Japan. We developed these experimental materials, and we achieved remarkable results using these materials in the electromagnetism class.

Effect of a broad recombination zone with a triple-emitting layer on the efficiency of blue phosphorescent organic light-emitting diodes

NASA Astrophysics Data System (ADS)

Lee, Seok Jae; Koo, Ja Ryong; Lee, Ho Won; Lee, Song Eun; Yang, Hyung Jin; Yoon, Seung Soo; Park, Jaehoon; Kim, Young Kwan

2014-11-01

The device characteristics of blue phosphorescent organic lightemitting diodes (PHOLEDs) with a broad recombination region within emitting layers (EMLs) were investigated by changing the combination and the composition of the host materials. Six types of devices were fabricated with the novel host material 9-(4-(triphenylsilyl)phenyl)-9H-carbazole, hole transport-type host material N,N'-dicarbazolyl-3,5-benzene, and electron transporttype host material 2,2',2″-(1,3,5-benzenetriyl)tris-[1-phenyl-1H-benzimidazole] as diverse EML structures. Balanced chargecarrier injection and a distributed recombination zone within EMLs were achieved through a triple-emitting layer (T-EML). The properties of a device with a T-EML using a stepwise structure without any mixed host system were found to be superior to the other PHOLEDs. This can be explained in terms of improved charge balance and triplet-exciton confinement within the broad recombination region. [Figure not available: see fulltext.

Theory and computation of general force balance in non-axisymmetric tokamak equilibria

NASA Astrophysics Data System (ADS)

Park, Jong-Kyu; Logan, Nikolas; Wang, Zhirui; Kim, Kimin; Boozer, Allen; Liu, Yueqiang; Menard, Jonathan

2014-10-01

Non-axisymmetric equilibria in tokamaks can be effectively described by linearized force balance. In addition to the conventional isotropic pressure force, there are three important components that can strongly contribute to the force balance; rotational, anisotropic tensor pressure, and externally given forces, i.e. ∇ --> p + ρv-> . ∇ --> v-> + ∇ --> . <-->Π + f-> = j-> × B-> , especially in, but not limited to, high β and rotating plasmas. Within the assumption of nested flux surfaces, Maxwell equations and energy minimization lead to the modified-generalized Newcomb equation for radial displacements with simple algebraic relations for perpendicular and parallel displacements, including an inhomogeneous term if any of the forces are not explicitly dependent on displacements. The general perturbed equilibrium code (GPEC) solves this force balance consistent with energy and torque given by external perturbations. Local and global behaviors of solutions will be discussed when ∇ --> . <-->Π is solved by the semi-analytic code PENT and will be compared with MARS-K. Any first-principle transport code calculating ∇ --> . <-->Π or f-> , e.g. POCA, can also be incorporated without demanding iterations. This work was supported by DOE Contract DE-AC02-09CH11466.

Multi-A Graph Patrolling and Partitioning

NASA Astrophysics Data System (ADS)

Elor, Y.; Bruckstein, A. M.

2012-12-01

We introduce a novel multi agent patrolling algorithm inspired by the behavior of gas filled balloons. Very low capability ant-like agents are considered with the task of patrolling an unknown area modeled as a graph. While executing the proposed algorithm, the agents dynamically partition the graph between them using simple local interactions, every agent assuming the responsibility for patrolling his subgraph. Balanced graph partition is an emergent behavior due to the local interactions between the agents in the swarm. Extensive simulations on various graphs (environments) showed that the average time to reach a balanced partition is linear with the graph size. The simulations yielded a convincing argument for conjecturing that if the graph being patrolled contains a balanced partition, the agents will find it. However, we could not prove this. Nevertheless, we have proved that if a balanced partition is reached, the maximum time lag between two successive visits to any vertex using the proposed strategy is at most twice the optimal so the patrol quality is at least half the optimal. In case of weighted graphs the patrol quality is at least (1)/(2){lmin}/{lmax} of the optimal where lmax (lmin) is the longest (shortest) edge in the graph.

Discrete bivariate population balance modelling of heteroaggregation processes.

PubMed

Rollié, Sascha; Briesen, Heiko; Sundmacher, Kai

2009-08-15

Heteroaggregation in binary particle mixtures was simulated with a discrete population balance model in terms of two internal coordinates describing the particle properties. The considered particle species are of different size and zeta-potential. Property space is reduced with a semi-heuristic approach to enable an efficient solution. Aggregation rates are based on deterministic models for Brownian motion and stability, under consideration of DLVO interaction potentials. A charge-balance kernel is presented, relating the electrostatic surface potential to the property space by a simple charge balance. Parameter sensitivity with respect to the fractal dimension, aggregate size, hydrodynamic correction, ionic strength and absolute particle concentration was assessed. Results were compared to simulations with the literature kernel based on geometric coverage effects for clusters with heterogeneous surface properties. In both cases electrostatic phenomena, which dominate the aggregation process, show identical trends: impeded cluster-cluster aggregation at low particle mixing ratio (1:1), restabilisation at high mixing ratios (100:1) and formation of complex clusters for intermediate ratios (10:1). The particle mixing ratio controls the surface coverage extent of the larger particle species. Simulation results are compared to experimental flow cytometric data and show very satisfactory agreement.

Design of Balanced Mixers for ALMA Band-10

NASA Astrophysics Data System (ADS)

Shitov, Sergey V.; Koryukin, Oleg V.; Uzawa, Yoshinori; Noguchi, Takashi; Uvarov, Andrey V.; Bukovski, Maksim A.; Cohn, Ilya A.

2007-06-01

Two variants of balanced mixer employing twin-SIS structure are under development for 787-950 GHz frequency range. Easy-to-use Geometry Transformation method for modeling of superconducting microstrips is developed, compared to referenced methods and used for design of the mixers. Lens-antenna mixer is based on cross-slot antenna; it does not need any intervening optics between its lens and sub-reflector of ALMA telescope; simple yet efficient composition of lens-antenna cartridge is suggested. Compact single-chamber balanced waveguide mixer employs two SIS chips and capacitive probe for LO injection; coupling above -3 dB and signal loss below -20 dB are expected. Need in shifting of resonance frequency of twin-SIS mixer towards top of the frequency band is predicted using Tucker's theory in large-signal approximation. TRX considerably below 200 K (DSB) is simulated using high-quality hybrid SIS junction for NbTiN/Nb - AlOx - Nb/Al for Jc = 12 kA/cm2.

A multi-objective genetic algorithm for a mixed-model assembly U-line balancing type-I problem considering human-related issues, training, and learning

NASA Astrophysics Data System (ADS)

Rabbani, Masoud; Montazeri, Mona; Farrokhi-Asl, Hamed; Rafiei, Hamed

2016-12-01

Mixed-model assembly lines are increasingly accepted in many industrial environments to meet the growing trend of greater product variability, diversification of customer demands, and shorter life cycles. In this research, a new mathematical model is presented considering balancing a mixed-model U-line and human-related issues, simultaneously. The objective function consists of two separate components. The first part of the objective function is related to balance problem. In this part, objective functions are minimizing the cycle time, minimizing the number of workstations, and maximizing the line efficiencies. The second part is related to human issues and consists of hiring cost, firing cost, training cost, and salary. To solve the presented model, two well-known multi-objective evolutionary algorithms, namely non-dominated sorting genetic algorithm and multi-objective particle swarm optimization, have been used. A simple solution representation is provided in this paper to encode the solutions. Finally, the computational results are compared and analyzed.

Energy balance in adrenalectomized ob/ob mice: effects of dietary starch and glucose.

PubMed

Warwick, B P; Romsos, D R

1988-07-01

Effects of different carbohydrate types on energy balance, fatty acid synthesis, and plasma insulin concentrations in adrenalectomized ob/ob mice were investigated. Obese (ob/ob) and lean mice adrenalectomized at 4 wk of age received one of four high-carbohydrate powdered diets for 3 wk: stock, glucose, starch, or starch plus wheat bran. Adrenalectomy reduced energy intake of ob/ob mice equally independent of diet type, whereas energetic efficiency, in vivo rates of fatty acid synthesis in liver and white adipose tissue, and plasma insulin concentrations were substantially reduced to approach values in lean mice in all adrenalectomized ob/ob mice except those fed glucose. The ability of adrenalectomy to normalize energy balance in ob/ob mice depends on factors other than the reduced circulating concentration of glucocorticoids alone. Diet composition is a crucial factor, and striking differences exist between semipurified diets containing a simple sugar (glucose) and those containing a complex carbohydrate (starch), with no additional effect of dietary fiber (wheat bran).

A simple scoring system for predicting early major complications in spine surgery: the cumulative effect of age and size of surgery.

PubMed

Brasil, Albert Vincent Berthier; Teles, Alisson R; Roxo, Marcelo Ricardo; Schuster, Marcelo Neutzling; Zauk, Eduardo Ballverdu; Barcellos, Gabriel da Costa; Costa, Pablo Ramon Fruett da; Ferreira, Nelson Pires; Kraemer, Jorge Luiz; Ferreira, Marcelo Paglioli; Gobbato, Pedro Luis; Worm, Paulo Valdeci

2016-10-01

To analyze the cumulative effect of risk factors associated with early major complications in postoperative spine surgery. Retrospective analysis of 583 surgically-treated patients. Early "major" complications were defined as those that may lead to permanent detrimental effects or require further significant intervention. A balanced risk score was built using multiple logistic regression. Ninety-two early major complications occurred in 76 patients (13%). Age > 60 years and surgery of three or more levels proved to be significant independent risk factors in the multivariate analysis. The balanced scoring system was defined as: 0 points (no risk factor), 2 points (1 factor) or 4 points (2 factors). The incidence of early major complications in each category was 7% (0 points), 15% (2 points) and 29% (4 points) respectively. This balanced scoring system, based on two risk factors, represents an important tool for both surgical indication and for patient counseling before surgery.

Highly efficient single-layer dendrimer light-emitting diodes with balanced charge transport

NASA Astrophysics Data System (ADS)

Anthopoulos, Thomas D.; Markham, Jonathan P. J.; Namdas, Ebinazar B.; Samuel, Ifor D. W.; Lo, Shih-Chun; Burn, Paul L.

2003-06-01

High-efficiency single-layer-solution-processed green light-emitting diodes based on a phosphorescent dendrimer are demonstrated. A peak external quantum efficiency of 10.4% (35 cd/A) was measured for a first generation fac-tris(2-phenylpyridine) iridium cored dendrimer when blended with 4,4'-bis(N-carbazolyl)biphenyl and electron transporting 1,3,5-tris(2-N-phenylbenzimidazolyl)benzene at 8.1 V. A maximum power efficiency of 12.8 lm/W was measured also at 8.1 V and 550 cd/m2. These results indicate that, by simple blending of bipolar and electron-transporting molecules, highly efficient light-emitting diodes can be made employing a very simple device structure.

Simple artificial neural networks that match probability and exploit and explore when confronting a multiarmed bandit.

PubMed

Dawson, Michael R W; Dupuis, Brian; Spetch, Marcia L; Kelly, Debbie M

2009-08-01

The matching law (Herrnstein 1961) states that response rates become proportional to reinforcement rates; this is related to the empirical phenomenon called probability matching (Vulkan 2000). Here, we show that a simple artificial neural network generates responses consistent with probability matching. This behavior was then used to create an operant procedure for network learning. We use the multiarmed bandit (Gittins 1989), a classic problem of choice behavior, to illustrate that operant training balances exploiting the bandit arm expected to pay off most frequently with exploring other arms. Perceptrons provide a medium for relating results from neural networks, genetic algorithms, animal learning, contingency theory, reinforcement learning, and theories of choice.

High power arcjet

NASA Technical Reports Server (NTRS)

Auweter-Kurtz, M.; Glocker, B.; Goelz, T. M.; Habiger, H.; Kurtz, H. L.; Schrade, H. O.; Wegmann, T.

1990-01-01

The activities on the development of the high power arc jet HIPARC, the thrust balance, and plasma diagnostic probes are discussed. Modifications of the HIPARC design and a synopsis of the materials used are given. Further experimental results with the TT30 thruster in the 50 kW range are presented. Some first calibration measurements of the thrust balance are also included. Progress concerning the development of plasma diagnostic devices is documented.

Walking the Tightrope: The Balance between Innovation and Leadership. Proceedings of the Annual International Conference of the Chair Academy (6th, Reno, NV, February 12-15, 1997).

ERIC Educational Resources Information Center

National Community Coll. Chair Academy, Mesa, AZ.

The papers provided in this proceedings discuss the roles and responsibilities of chairs, deans, and other organizational leaders at community colleges, focusing on strategies for balancing innovative educational approaches with traditional leadership. Following background material on the Chair Academy, the following three keynote speeches are…

Effect of synthetic surfaces and vegetation in urban areas on human energy balance and comfort

Treesearch

Thomas F. Stark; David R. Miller

1977-01-01

The thermal balance of a standard man was quantified for a variety of urban and rural summer daytime microclimates. The resulting net heat-load data were correlated with the relative amounts of vegetation and synthetic materials at each site. By extrapolating these results, it is possible to estimate the expected heat load of a proposed development before it is built...

Mobile Element Reservoir Mass Balance on Mars: New SIMS and EMP Data from Lonar and Mistastin Craters

NASA Technical Reports Server (NTRS)

Newsom, H. E.; Hagerty, J. J.; Shearer, C. W.

2002-01-01

New SIMS data for mobile elements in Lonar Crater clay minerals are remarkably similar to data for alteration material in the Lafayette Mars meteorite. This work strongly supports the use of terrestrial analogues for Mars, including a new mass balance model for mobile elements through time. Additional information is contained in the original extended abstract.

Energy Balance Models and Planetary Dynamics

NASA Technical Reports Server (NTRS)

Domagal-Goldman, Shawn

2012-01-01

We know that planetary dynamics can have a significant affect on the climate of planets. Planetary dynamics dominate the glacial-interglacial periods on Earth, leaving a significant imprint on the geological record. They have also been demonstrated to have a driving influence on the climates of other planets in our solar system. We should therefore expect th.ere to be similar relationships on extrasolar planets. Here we describe a simple energy balance model that can predict the growth and thickness of glaciers, and their feedbacks on climate. We will also describe model changes that we have made to include planetary dynamics effects. This is the model we will use at the start of our collaboration to handle the influence of dynamics on climate.

Statistical foundations of liquid-crystal theory: I. Discrete systems of rod-like molecules.

PubMed

Seguin, Brian; Fried, Eliot

2012-12-01

We develop a mechanical theory for systems of rod-like particles. Central to our approach is the assumption that the external power expenditure for any subsystem of rods is independent of the underlying frame of reference. This assumption is used to derive the basic balance laws for forces and torques. By considering inertial forces on par with other forces, these laws hold relative to any frame of reference, inertial or noninertial. Finally, we introduce a simple set of constitutive relations to govern the interactions between rods and find restrictions necessary and sufficient for these laws to be consistent with thermodynamics. Our framework provides a foundation for a statistical mechanical derivation of the macroscopic balance laws governing liquid crystals.

Tropical Peatland Geomorphology and Hydrology

NASA Astrophysics Data System (ADS)

Cobb, A.; Harvey, C. F.

2017-12-01

Tropical peatlands cover many low-lying areas in the tropics. In tropical peatlands, a feedback between hydrology, landscape morphology, and carbon storage causes waterlogged organic matter to accumulate into gently mounded land forms called peat domes over thousands of years. Peat domes have a stable morphology in which peat production is balanced by loss and net precipitation is balanced by lateral flow, creating a link between peatland morphology, rainfall patterns and drainage networks. We show how landscape morphology can be used to make inferences about hydrologic processes in tropical peatlands. In particular, we show that approaches using simple storage-discharge relationships for catchments are especially well suited to tropical peatlands, allowing river forecasting based on peatland morphology in catchments with tropical peatland subcatchments.

A proposed approach to the application of nonlinear irreversible thermodynamics to fracture in composite materials

NASA Technical Reports Server (NTRS)

Lindenmeyer, P. H.

1983-01-01

The fracture criteria upon which most fracture mechanics is based involves an energy balance that is not appropriate for the fracture mechanics of viscoelastic materials such as polymer matrix composites. A more appropriate criterion based upon nonequilibrium thermodynamics and involving a power balance rather than an energy balance is proposed. This crierion is based upon a reformulation of the second law of thermodynamics which focuses attention on the total Legendre transform of energy expressed as a functional over time and space. This excess energy functional can be shown to be equivalent to the Rice J integral if the only irreversible process is the propogation of a single crack completely through the thickness of the specimen and if the crack propogation is assured to be independent of time. For the more general case of more than one crack in a viscoelastic medium integration over both time and space is required. Two experimentally measurable parameters are proposed which should permit the evaluation of this more general fracture criterion.

The importance of accurate glacier albedo for estimates of surface mass balance on Vatnajökull: Evaluating the surface energy budget in a Regional Climate Model with automatic weather station observations

NASA Astrophysics Data System (ADS)

Steffensen Schmidt, Louise; Aðalgeirsdóttir, Guðfinna; Guðmundsson, Sverrir; Langen, Peter L.; Pálsson, Finnur; Mottram, Ruth; Gascoin, Simon; Björnsson, Helgi

2017-04-01

The evolution of the surface mass balance of Vatnajökull ice cap, Iceland, from 1981 to the present day is estimated by using the Regional Climate Model HIRHAM5 to simulate the surface climate. A new albedo parametrization is used for the simulation, which describes the albedo with an exponential decay with time. In addition, it utilizes a new background map of the ice albedo created from MODIS data. The simulation is validated against observed daily values of weather parameters from five Automatic Weather Stations (AWSs) from 2001-2014, as well as mass balance measurements from 1995-2014. The modelled albedo is overestimated at the AWS sites in the ablation zone, which we attribute to an overestimation of the thickness of the snow layer and the model not accounting for dust and ash deposition during dust storms and volcanic eruptions. A comparison with the specific summer, winter, and annual mass balance for all Vatnajökull from 1995-2014 shows a good overall fit during the summer, with the model underestimating the balance by only 0.04 m w. eq. on average. The winter balance, on the other hand, is overestimated by 0.5 m w. eq. on average, mostly due to an overestimation of the precipitation at the highest areas of the ice cap. A simple correction of the accumulation at these points reduced the error to 0.15 m w. eq. The model captures the evolution of the specific mass balance well, for example it captures an observed shift in the balance in the mid-1990s, which gives us confidence in the results for the entire model run. Our results show the importance of bare ice albedo for modelled mass balance and that processes not currently accounted for in RCMs, such as dust storms, are an important source of uncertainty in estimates of the snow melt rate.

Solid-State Nuclear Power

NASA Technical Reports Server (NTRS)

George, Jeffrey A.

2012-01-01

A strategy for "Solid-State" Nuclear Power is proposed to guide development of technologies and systems into the second 50 years of nuclear spaceflight. The strategy emphasizes a simple and highly integrated system architecture with few moving parts or fluid loops; the leverage of modern advances in materials, manufacturing, semiconductors, microelectromechanical and nanotechnology devices; and the targeted advancement of high temperature nuclear fuels, materials and static power conversion to enable high performance from simple system topologies.

A simple design of an artificial electromagnetic black hole

NASA Astrophysics Data System (ADS)

Lu, Wanli; Jin, JunFeng; Lin, Zhifang; Chen, Huanyang

2010-09-01

We conduct a rigorous study on the properties of an artificial electromagnetic black hole for transverse magnetic modes. A multilayered structure of such a black hole is then proposed as a reduced variety for easy experimental implementations. An actual design of composite materials based on the effective medium theory is given with only five kinds of real isotropic materials. The finite element method confirms the functionality of such a simple design.

The Synthesis of Proteins-A Simple Experiment To Show the Procedures and Problems of Using Radioisotopes in Biochemical Studies

NASA Astrophysics Data System (ADS)

Hawcroft, David M.

1996-11-01

Courses of organic chemistry frequently include studies of biochemistry and hence of biochemical techniques. Radioisotopes have played a major role in the understanding of metabolic pathways, transport, enzyme activity and other processes. The experiment described in this paper uses simple techniques to illustrate the procedures involved in working with radioisotopes when following a simplified metabolic pathway. Safety considerations are discussed and a list of safety rules is provided, but the experiment itself uses very low levels of a weak beta-emitting isotope (tritium). Plant material is suggested to reduce legal, financial and emotive problems, but the techniques are applicable to all soft-tissued material. The problems involved in data interpretation in radioisotope experiments resulting from radiation quenching are resolved by simple correction calculations, and the merits of using radioisotopes shown by a calculation of the low mass of material being measured. Suggestions for further experiments are given.

High Dielectric Low Loss Transparent Glass Material Based Dielectric Resonator Antenna with Wide Bandwidth Operation

NASA Astrophysics Data System (ADS)

Mehmood, Arshad; Zheng, Yuliang; Braun, Hubertus; Hovhannisyan, Martun; Letz, Martin; Jakoby, Rolf

2015-01-01

This paper presents the application of new high permittivity and low loss glass material for antennas. This glass material is transparent. A very simple rectangular dielectric resonator antenna is designed first with a simple microstrip feeding line. In order to widen the bandwidth, the feed of the design is modified by forming a T-shaped feeding. This new design enhanced the bandwidth range to cover the WLAN 5 GHz band completely. The dielectric resonator antenna cut into precise dimensions is placed on the modified microstrip feed line. The design is simple and easy to manufacture and also very compact in size of only 36 × 28 mm. A -10 dB impedance bandwidth of 18% has been achieved, which covers the frequency range from 5.15 GHz to 5.95 GHz. Simulations of the measured return loss and radiation patterns are presented and discussed.

10 CFR 75.33 - Accounting reports.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 2 2011-01-01 2011-01-01 false Accounting reports. 75.33 Section 75.33 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) SAFEGUARDS ON NUCLEAR MATERIAL-IMPLEMENTATION OF US/IAEA AGREEMENT Reports § 75.33 Accounting reports. (a)(1) The accounting reports for each IAEA material balance area must...

10 CFR 75.33 - Accounting reports.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 2 2010-01-01 2010-01-01 false Accounting reports. 75.33 Section 75.33 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) SAFEGUARDS ON NUCLEAR MATERIAL-IMPLEMENTATION OF US/IAEA AGREEMENT Reports § 75.33 Accounting reports. (a)(1) The accounting reports for each IAEA material balance area must...

Development of a 5-Component Balance for Water Tunnel Applications

NASA Technical Reports Server (NTRS)

Suarez, Carlos J.; Kramer, Brian R.; Smith, Brooke C.

1999-01-01

The principal objective of this research/development effort was to develop a multi-component strain gage balance to measure both static and dynamic forces and moments on models tested in flow visualization water tunnels. A balance was designed that allows measuring normal and side forces, and pitching, yawing and rolling moments (no axial force). The balance mounts internally in the model and is used in a manner typical of wind tunnel balances. The key differences between a water tunnel balance and a wind tunnel balance are the requirement for very high sensitivity since the loads are very low (typical normal force is 90 grams or 0.2 lbs), the need for water proofing the gage elements, and the small size required to fit into typical water tunnel models. The five-component balance was calibrated and demonstrated linearity in the responses of the primary components to applied loads, very low interactions between the sections and no hysteresis. Static experiments were conducted in the Eidetics water tunnel with delta wings and F/A-18 models. The data were compared to forces and moments from wind tunnel tests of the same or similar configurations. The comparison showed very good agreement, providing confidence that loads can be measured accurately in the water tunnel with a relatively simple multi-component internal balance. The success of the static experiments encouraged the use of the balance for dynamic experiments. Among the advantages of conducting dynamic tests in a water tunnel are less demanding motion and data acquisition rates than in a wind tunnel test (because of the low-speed flow) and the capability of performing flow visualization and force/moment (F/M) measurements simultaneously with relative simplicity. This capability of simultaneous flow visualization and for F/M measurements proved extremely useful to explain the results obtained during these dynamic tests. In general, the development of this balance should encourage the use of water tunnels for a wider range of quantitative and qualitative experiments, especially during the preliminary phase of aircraft design.

Medical Devices Assess, Treat Balance Disorders

NASA Technical Reports Server (NTRS)

2009-01-01

You may have heard the phrase as difficult as walking and chewing gum as a joking way of referring to something that is not difficult at all. Just walking, however, is not all that simple physiologically speaking. Even standing upright is an undertaking requiring the complex cooperation of multiple motor and sensory systems including vision, the inner ear, somatosensation (sensation from the skin), and proprioception (the sense of the body s parts in relation to each other). The compromised performance of any of these elements can lead to a balance disorder, which in some form affects nearly half of Americans at least once in their lifetimes, from the elderly, to those with neurological or vestibular (inner ear) dysfunction, to athletes with musculoskeletal injuries, to astronauts returning from space. Readjusting to Earth s gravity has a significant impact on an astronaut s ability to balance, a result of the brain switching to a different "model" for interpreting sensory input in normal gravity versus weightlessness. While acclimating, astronauts can experience headaches, motion sickness, and problems with perception. To help ease the transition and study the effects of weightlessness on the body, NASA has conducted many investigations into post-flight balance control, realizing this research can help treat patients with balance disorders on Earth as well. In the 1960s, the NASA-sponsored Man Vehicle Laboratory at the Massachusetts Institute of Technology (MIT) studied the effects of prolonged space flight on astronauts. The lab s work intrigued MIT doctoral candidate Lewis Nashner, who began conducting NASA-funded research on human movement and balance under the supervision of Dr. Larry Young in the MIT Department of Aeronautics and Astronautics. In 1982, Nashner s work resulted in a noninvasive clinical technique for assessing the cooperative systems that allow the body to balance, commonly referred to as computerized dynamic posturography (CDP). CDP employs a series of dynamic protocols to isolate and assess balance function deficiencies. The technology was based on Nashner s novel, engineering-inspired concept of balance as an adaptable collaboration between multiple sensory and motor systems. CDP proved useful not only for examining astronauts, but for anyone suffering from balance problems. Today, CDP is the standard medical tool for objectively evaluating balance control.

Anorexia: Highlights in Traditional Persian medicine and conventional medicine

PubMed Central

Nimrouzi, Majid; Zarshenas, Mohammad Mehdi

2018-01-01

Objective: Anorexia and impaired appetite (Dysorexia) are common symptoms with varying causes, and often need no serious medical intervention. Anorexia nervosa (AN) is a chronic psychiatric disease with a high mortality rate. In Traditional Persian Medicine (TPM), anorexia is a condition in which anorexic patients lose appetite due to dystemperament. This review aims to discuss the common points of traditional and conventional approaches rather than introducing Persian medical recommendations suitable for nowadays use. Materials and Methods: For this purpose, Avicenna's Canon of Medicine, main TPM resources and important databases were reviewed using the related keywords. Results: Despite complex hormonal explanation, etiology of AN in conventional approach is not completely understood. In TPM approach, the etiology and recommended interventions are thoroughly defined based on humoral pathophysiology. In TPM approach, disease states are regarded as the result of imbalances in organs’ temperament and humors. In anorexia with simple dystemperament, the physician should attempt to balance the temperament using foods and medicaments which have opposite quality of temperament. Lifestyle, spiritual diseases (neuro – psychological) and gastrointestinal worms are the other causes for reducing appetite. Also, medicines and foods with warm temperaments (such as Pea soup and Mustard) are useful for these patients (cold temperament). Conclusion: Although the pathophysiology of AN in TPM is different in comparison with conventional views, TPM criteria for treatment this disorder is similar to those of current medicine. Recommending to have spiritual support and a healthy lifestyle are common in both views. Simple safe interventions recommended by TPM may be considered as alternative medical modalities after being confirmed by well-designed clinical trials. PMID:29387569

Removing function model and experiments on ultrasonic polishing molding die

NASA Astrophysics Data System (ADS)

Huang, Qitai; Ni, Ying; Yu, Jingchi

2010-10-01

Low temperature glass molding technology is the main method on volume-producing high precision middle and small diameter optical cells in the future. While the accuracy of the molding die will effect the cell precision, so the high precision molding die development is one of the most important part of the low temperature glass molding technology. The molding die is manufactured from high rigid and crisp metal alloy, with the ultrasonic vibration character of high vibration frequency and concentrative energy distribution; abrasive particles will impact the rigid metal alloy surface with very high speed that will remove the material from the work piece. Ultrasonic can make the rigid metal alloy molding die controllable polishing and reduce the roughness and surface error. Different from other ultrasonic fabrication method, untouched ultrasonic polishing is applied on polish the molding die, that means the tool does not touch the work piece in the process of polishing. The abrasive particles vibrate around the balance position with high speed and frequency under the drive of ultrasonic vibration in the liquid medium and impact the workspace surface, the energy of abrasive particles come from ultrasonic vibration, while not from the direct hammer blow of the tool. So a nummular vibrator simple harmonic vibrates on an infinity plane surface is considered as a model of ultrasonic polishing working condition. According to Huygens theory the sound field distribution on a plane surface is analyzed and calculated, the tool removing function is also deduced from this distribution. Then the simple point ultrasonic polishing experiment is proceeded to certificate the theory validity.

Feasibility of a Brief Community-Based Train-the-Trainer Lesson to Reduce the Risk of Falls among Community Dwelling Older Adults

ERIC Educational Resources Information Center

Gunter, Katherine B.; John, Deborah H.

2014-01-01

The Better Balance, Better Bones, Better Bodies (B-Better©) program was developed to disseminate simple home-based strategies to prevent falls and improve functional health of older adults using a train-the-trainer model. Delivered by Family & Community Education Study Group program volunteers, the lesson stresses the importance of a…

Site-specific critical acid load estimates for forest soils in the Osborn Creek watershed, Michigan

Treesearch

Trevor Hobbs; Jason Lynch; Randy Kolka

2017-01-01

Anthropogenic acid deposition has the potential to accelerate leaching of soil cations, and in turn, deplete nutrients essential to forest vegetation. The critical load concept, employing a simple mass balance (SMB) approach, is often used to model this process. In an evaluation under the U.S. Forest Service Watershed Condition Framework program, soils in all 6th level...

Marangoni Convection and Deviations from Maxwells' Evaporation Model

NASA Technical Reports Server (NTRS)

Segre, P. N.; Snell, E. H.; Adamek, D. H.

2003-01-01

We investigate the convective dynamics of evaporating pools of volatile liquids using an ultra-sensitive thermal imaging camera. During evaporation, there are significant convective flows inside the liquid due to Marangoni forces. We find that Marangoni convection during evaporation can dramatically affect the evaporation rates of volatile liquids. A simple heat balance model connects the convective velocities and temperature gradients to the evaporation rates.