Annular wave packets at Dirac points in graphene and their probability-density oscillation.

PubMed

Luo, Ji; Valencia, Daniel; Lu, Junqiang

2011-12-14

Wave packets in graphene whose central wave vector is at Dirac points are investigated by numerical calculations. Starting from an initial Gaussian function, these wave packets form into annular peaks that propagate to all directions like ripple-rings on water surface. At the beginning, electronic probability alternates between the central peak and the ripple-rings and transient oscillation occurs at the center. As time increases, the ripple-rings propagate at the fixed Fermi speed, and their widths remain unchanged. The axial symmetry of the energy dispersion leads to the circular symmetry of the wave packets. The fixed speed and widths, however, are attributed to the linearity of the energy dispersion. Interference between states that, respectively, belong to two branches of the energy dispersion leads to multiple ripple-rings and the probability-density oscillation. In a magnetic field, annular wave packets become confined and no longer propagate to infinity. If the initial Gaussian width differs greatly from the magnetic length, expanding and shrinking ripple-rings form and disappear alternatively in a limited spread, and the wave packet resumes the Gaussian form frequently. The probability thus oscillates persistently between the central peak and the ripple-rings. If the initial Gaussian width is close to the magnetic length, the wave packet retains the Gaussian form and its height and width oscillate with a period determined by the first Landau energy. The wave-packet evolution is determined jointly by the initial state and the magnetic field, through the electronic structure of graphene in a magnetic field. © 2011 American Institute of Physics

Evaluation of Bare Ground on Rangelands using Unmanned Aerial Vehicles

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

Robert P. Breckenridge; Maxine Dakins

2011-01-01

Attention is currently being given to methods that assess the ecological condition of rangelands throughout the United States. There are a number of different indicators that assess ecological condition of rangelands. Bare Ground is being considered by a number of agencies and resource specialists as a lead indicator that can be evaluated over a broad area. Traditional methods of measuring bare ground rely on field technicians collecting data along a line transect or from a plot. Unmanned aerial vehicles (UAVs) provide an alternative to collecting field data, can monitor a large area in a relative short period of time, andmore » in many cases can enhance safety and time required to collect data. In this study, both fixed wing and helicopter UAVs were used to measure bare ground in a sagebrush steppe ecosystem. The data were collected with digital imagery and read using the image analysis software SamplePoint. The approach was tested over seven different plots and compared against traditional field methods to evaluate accuracy for assessing bare ground. The field plots were located on the Idaho National Laboratory (INL) site west of Idaho Falls, Idaho in locations where there is very little disturbance by humans and the area is grazed only by wildlife. The comparison of fixed-wing and helicopter UAV technology against field estimates shows good agreement for the measurement of bare ground. This study shows that if a high degree of detail and data accuracy is desired, then a helicopter UAV may be a good platform. If the data collection objective is to assess broad-scale landscape level changes, then the collection of imagery with a fixed-wing system is probably more appropriate.« less

Beam dynamics validation of the Halbach Technology FFAG Cell for Cornell-BNL Energy Recovery Linac

NASA Astrophysics Data System (ADS)

Méot, F.; Tsoupas, N.; Brooks, S.; Trbojevic, D.

2018-07-01

The Cornell-BNL Electron Test Accelerator (CBETA), a 150 MeV energy recovery linac (ERL) now in construction at Cornell, employs a fixed-field alternating gradient optics return loop: a single beam line comprised of FFAG cells, which accepts four recirculated energies. CBETA FFAG cell uses Halbach permanent magnet technology, its design studies have covered an extended period of time supported by extensive particle dynamics simulations using computed 3-D field map models. This approach is discussed, and illustrated here, based on the final stage in these beam dynamics studies, namely the validation of a ultimate, optimized design of the Halbach cell.

Use of nitrogen-fixing bacteria as biofertiliser for non-legumes: prospects and challenges.

PubMed

Bhattacharjee, Rumpa Biswas; Singh, Aqbal; Mukhopadhyay, S N

2008-08-01

The potential of nitrogen-fixing (NF) bacteria to form a symbiotic relationship with leguminous plants and fix atmospheric nitrogen has been exploited in the field to meet the nitrogen requirement of the latter. This phenomenon provides an alternative to the use of the nitrogenous fertiliser whose excessive and imbalanced use over the decades has contributed to green house emission (N2O) and underground water leaching. Recently, it was observed that non-leguminous plants like rice, sugarcane, wheat and maize form an extended niche for various species of NF bacteria. These bacteria thrive within the plant, successfully colonizing roots, stems and leaves. During the association, the invading bacteria benefit the acquired host with a marked increase in plant growth, vigor and yield. With increasing population, the demand of non-leguminous plant products is growing. In this regard, the richness of NF flora within non-leguminous plants and extent of their interaction with the host definitely shows a ray of hope in developing an ecofriendly alternative to the nitrogenous fertilisers. In this review, we have discussed the association of NF bacteria with various non-leguminous plants emphasizing on their potential to promote host plant growth and yield. In addition, plant growth-promoting traits observed in these NF bacteria and their mode of interaction with the host plant have been described briefly.

Transverse beam dynamics in non-linear Fixed Field Alternating Gradient accelerators

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

Haj, Tahar M.; Meot, F.

2016-03-02

In this paper, we present some aspects of the transverse beam dynamics in Fixed Field Ring Accelerators (FFRA): we start from the basic principles in order to derive the linearized transverse particle equations of motion for FFRA, essentially FFAGs and cyclotrons are considered here. This is a simple extension of a previous work valid for linear lattices that we generalized by including the bending terms to ensure its correctness for FFAG lattice. The space charge term (contribution of the internal coulombian forces of the beam) is contained as well, although it is not discussed here. The emphasis is on themore » scaling FFAG type: a collaboration work is undertaken in view of better understanding the properties of the 150 MeV scaling FFAG at KURRI in Japan, and progress towards high intensity operation. Some results of the benchmarking work between different codes are presented. Analysis of certain type of field imperfections revealed some interesting features about this machine that explain some of the experimental results and generalize the concept of a scaling FFAG to a non-scaling one for which the tune variations obey a well-defined law.« less

Short-term memory for responses: the "choose-small" effect.

PubMed Central

Fetterman, J G; MacEwen, D

1989-01-01

Pigeons' short-term memory for fixed-ratio requirements was assessed using a delayed symbolic matching-to-sample procedure. Different choices were reinforced after fixed-ratio 10 and fixed-ratio 40 requirements, and delays of 0, 5, or 20 s were sometimes placed between sample ratios and choice. All birds made disproportionate numbers of responses to the small-ratio choice alternative when delays were interposed between ratios and choice, and this bias increased as a function of delay. Preference for the small fixed-ratio alternative was also observed on "no-sample" trials, during which the choice alternatives were presented without a prior sample ratio. This "choose-small" bias is analogous to results obtained by Spetch and Wilkie (1983) with event duration as the discriminative stimulus. The choose-small bias was attenuated when the houselight was turned on during delays, but overall accuracy was not influenced systematically by the houselight manipulation. PMID:2584917

Health economic analyses of domiciliary dental care and care at fixed clinics for elderly nursing home residents in Sweden.

PubMed

Lundqvist, M; Davidson, T; Ordell, S; Sjöström, O; Zimmerman, M; Sjögren, P

2015-03-01

Dental care for elderly nursing home residents is traditionally provided at fixed dental clinics, but domiciliary dental care is an emerging alternative. Longer life expectancy accompanied with increased morbidity, and hospitalisation or dependence on the care of others will contribute to a risk for rapid deterioration of oral health so alternative methods for delivering oral health care to vulnerable individuals for whom access to fixed dental clinics is an obstacle should be considered. The aim was to analyse health economic consequences of domiciliary dental care for elderly nursing home residents in Sweden, compared to dentistry at a fixed clinic. A review of relevant literature was undertaken complemented by interviews with nursing home staff, officials at county councils, and academic experts in geriatric dentistry. Domiciliary dental care and fixed clinic care were compared in cost analyses and cost-effectiveness analyses. The mean societal cost of domiciliary dental care for elderly nursing home residents was lower than dental care at a fixed clinic, and it was also considered cost-effective. Lower cost of dental care at a fixed dental clinic was only achieved in a scenario where dental care could not be completed in a domiciliary setting. Domiciliary dental care for elderly nursing home residents has a lower societal cost and is cost-effective compared to dental care at fixed clinics. To meet current and predicted need for oral health care in the ageing population alternative methods to deliver dental care should be available.

Beam dynamics validation of the Halbach Technology FFAG Cell for Cornell-BNL Energy Recovery Linac

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

Meot, Francois; Tsoupas, N.; Brooks, S.

The Cornell-BNL Electron Test Accelerator (CBETA), a 150 MeV energy recovery linac (ERL) now in construction at Cornell, employs a fixed-field alternating gradient optics return loop: a single beam line comprised of FFAG cells, which accepts four recirculated energies. CBETA FFAG cell uses Halbach permanent magnet technology, its design studies have covered an extended period of time supported by extensive particle dynamics simulations using computed 3-D field map models. As a result, this approach is discussed, and illustrated here, based on the final stage in these beam dynamics studies, namely the validation of a ultimate, optimized design of the Halbachmore » cell.« less

Beam dynamics validation of the Halbach Technology FFAG Cell for Cornell-BNL Energy Recovery Linac

DOE PAGES

Meot, Francois; Tsoupas, N.; Brooks, S.; ...

2018-04-16

The Cornell-BNL Electron Test Accelerator (CBETA), a 150 MeV energy recovery linac (ERL) now in construction at Cornell, employs a fixed-field alternating gradient optics return loop: a single beam line comprised of FFAG cells, which accepts four recirculated energies. CBETA FFAG cell uses Halbach permanent magnet technology, its design studies have covered an extended period of time supported by extensive particle dynamics simulations using computed 3-D field map models. As a result, this approach is discussed, and illustrated here, based on the final stage in these beam dynamics studies, namely the validation of a ultimate, optimized design of the Halbachmore » cell.« less

Tune-stabilized, non-scaling, fixed-field, alternating gradient accelerator

DOEpatents

Johnstone, Carol J [Warrenville, IL

2011-02-01

A FFAG is a particle accelerator having turning magnets with a linear field gradient for confinement and a large edge angle to compensate for acceleration. FODO cells contain focus magnets and defocus magnets that are specified by a number of parameters. A set of seven equations, called the FFAG equations relate the parameters to one another. A set of constraints, call the FFAG constraints, constrain the FFAG equations. Selecting a few parameters, such as injection momentum, extraction momentum, and drift distance reduces the number of unknown parameters to seven. Seven equations with seven unknowns can be solved to yield the values for all the parameters and to thereby fully specify a FFAG.

The debris-flow rheology myth

USGS Publications Warehouse

Iverson, R.M.; ,

2003-01-01

Models that employ a fixed rheology cannot yield accurate interpretations or predictions of debris-flow motion, because the evolving behavior of debris flows is too complex to be represented by any rheological equation that uniquely relates stress and strain rate. Field observations and experimental data indicate that debris behavior can vary from nearly rigid to highly fluid as a consequence of temporal and spatial variations in pore-fluid pressure and mixture agitation. Moreover, behavior can vary if debris composition changes as a result of grain-size segregation and gain or loss of solid and fluid constituents in transit. An alternative to fixed-rheology models is provided by a Coulomb mixture theory model, which can represent variable interactions of solid and fluid constituents in heterogeneous debris-flow surges with high-friction, coarse-grained heads and low-friction, liquefied tails. ?? 2003 Millpress.

A 1 GeV CW FFAG High Intensity Proton Driver

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

Johnstone, C.; Sheehy, S. L.

2012-05-01

The drive for high beam power, high duty cycle, and reliable beams at reasonable cost has focused world attention on fixed-field accelerators, notably Fixed-Field Alternating Gradient accelerators (FFAGs). High-intensity GeV proton drivers are of particular interest, as these encounter duty cycle and space-charge limits in the synchrotron and machine size concerns in the weaker-focusing cyclotron. Recently, the concept of isochronous orbits has been explored and developed for non-scaling FFAGs using powerful new methodologies in FFAG accelerator design. These new breeds of FFAGs have been identified by international collaborations for serious study thanks to their potential applications including Accelerator Driven Subcriticalmore » Reactors (ADS) a nd Accelerator Transmutation of Waste. The extreme reliability requirements for ADS mandate CW operation capability and the FFAG s strong focusing, particularly in the vertical, will serve to mitigate the effect of space charge (as compared with the weak- focusing cyclotron). This paper reports on these new advances in FFAG accelerator technology and presents a stable, 0.25-1GeV isochronous FFAG for an accelerator driven subcritical reactor.« less

Alternative management structures for municipal waste collection services: The influence of economic and political factors

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

Plata-Díaz, Ana María, E-mail: amplata@ugr.es; Zafra-Gómez, José Luis, E-mail: jlzafra@ugr.es; Pérez-López, Gemma, E-mail: gemmapl@ugr.es

2014-11-15

Highlights: • We analyzed the factors that influence on the restructuring of MSW services. • We evaluated five different alternatives for public and private service. • Our analysis covers a broad time horizon, 2002–2010. • We used a conditional fixed-effects logistic regression as the evaluation method. • Municipalities tend to contract out the MSW service in the presence of high costs and fiscal stress. - Abstract: Identifying and characterising the factors that determine why a local authority opts for a particular way of managing its waste collection service is an important issue, warranting research interest in the field of municipalmore » solid waste (MSW) management. This paper presents empirical evidence spanning a broad time horizon (2002–2010) showing that economic and political factors impact in different ways on the provision of waste management services. We examine five alternatives in this area, including public and private service delivery formulas and, within each field, individual and joint options. Our findings highlight the importance of the service cost and that of the various indicators of fiscal stress as determinant factors of management decisions regarding the provision of MSW management services.« less

33 CFR 101.120 - Alternatives.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Alternatives. 101.120 Section 101... MARITIME SECURITY: GENERAL General § 101.120 Alternatives. (a) Alternative Security Agreements. (1) The U.S... Alternative Security Arrangements covering short international voyages on fixed routes between facilities...

Effects of high-intensity power-frequency electric fields on implanted modern multiprogrammable cardiac pacemakers.

PubMed

Butrous, G S; Meldrum, S J; Barton, D G; Male, J C; Bonnell, J A; Camm, A J

1982-05-01

The effect on an implanted, multiprogrammable pacemaker of power-frequency (50 Hz) electric fields up to an intensity (unperturbed value measured at 1.7 m) of 20 kV/m were assessed in ten paced patients. Radiotelemetric monitoring of the electrocardiogram allowed supervision of the electrocardiogram throughout exposure to the alternating electric field. Displacement body currents of up to 300μA were achieved depending on the position and height of the patient. None of the pacemakers was inhibited, triggered or reverted to fixed rate operation during the exposure. The programmable functions, programmability or output characteristics were not affected. Small changes in cardiac rate and rhythm elicited the correct pacemaker responses. Unlike earlier models of pacemaker, this modern implanted pacemaker, which represents `the state of the art', is not affected by 50 Hz electric fields likely to be encountered when standing underneath power lines.

Democratic Superstring Field Theory and Its Gauge Fixing

NASA Astrophysics Data System (ADS)

Kroyter, M.

This work is my contribution to the proceedings of the conference``SFT2010 -- the third international conference on string field theory and related topics'' and it reflects my talk there, which described the democratic string field theory and its gauge fixing. The democratic string field theory is the only fully RNS string field theory to date. It lives in the large Hilbert space and includes all picture numbers. Picture changing amounts in this formalism to a gauge transformation. We describe the theory and its properties and show that when partially gauge fixed it can be reduced to the modified theory and to the non-polynomial theory. In the latter case we can even include the Ramond sector in the picture-fixed action. We also show that another partial gauge-fixing leads to a new consistent string field theory at picture number -1.

41 CFR 302-12.109 - What must we consider in deciding whether to use the fixed-fee or cost-reimbursable contracting...

Code of Federal Regulations, 2010 CFR

2010-07-01

... deciding whether to use the fixed-fee or cost-reimbursable contracting method? 302-12.109 Section 302-12... Services Company § 302-12.109 What must we consider in deciding whether to use the fixed-fee or cost...-fee or cost-reimbursable contracting method: (a) Risk of alternative methods. Under a fixed fee...

46 CFR 95.05-10 - Fixed fire extinguishing systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... in special cases: (1) A fixed foam system may be used in cargo tanks. (2) A water sprinkling system.... Alternately, the Commandant may permit the installation of an approved water sprinkler system or other... is contracted for on or after November 19, 1952, a fixed carbon dioxide, foam, or water spray system...

46 CFR 95.05-10 - Fixed fire extinguishing systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... in special cases: (1) A fixed foam system may be used in cargo tanks. (2) A water sprinkling system.... Alternately, the Commandant may permit the installation of an approved water sprinkler system or other... is contracted for on or after November 19, 1952, a fixed carbon dioxide, foam, or water spray system...

46 CFR 95.05-10 - Fixed fire extinguishing systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... in special cases: (1) A fixed foam system may be used in cargo tanks. (2) A water sprinkling system.... Alternately, the Commandant may permit the installation of an approved water sprinkler system or other... is contracted for on or after November 19, 1952, a fixed carbon dioxide, foam, or water spray system...

46 CFR 95.05-10 - Fixed fire extinguishing systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... in special cases: (1) A fixed foam system may be used in cargo tanks. (2) A water sprinkling system.... Alternately, the Commandant may permit the installation of an approved water sprinkler system or other... is contracted for on or after November 19, 1952, a fixed carbon dioxide, foam, or water spray system...

Impact of Alternative Rate Structures on Distributed Solar Customer Electricity Bills

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

McLaren, Joyce A

Electric utilities are increasingly proposing changes to residential rate structures, in order to address concerns about their inability to recover fixed system costs from customers with grid connected distributed generation. The most common proposals have been to increase fixed charges, set minimum bills or instigate residential demand charges. This presentation provides results of an analysis to explore how these rate design alternatives impact electricity bills for PV and non-PV customers.

Impact of Rate Design Alternatives on Residential Solar Customer Bills. Increased Fixed Charges, Minimum Bills and Demand-based Rates

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

Bird, Lori; Davidson, Carolyn; McLaren, Joyce

With rapid growth in energy efficiency and distributed generation, electric utilities are anticipating stagnant or decreasing electricity sales, particularly in the residential sector. Utilities are increasingly considering alternative rates structures that are designed to recover fixed costs from residential solar photovoltaic (PV) customers with low net electricity consumption. Proposed structures have included fixed charge increases, minimum bills, and increasingly, demand rates - for net metered customers and all customers. This study examines the electricity bill implications of various residential rate alternatives for multiple locations within the United States. For the locations analyzed, the results suggest that residential PV customers offset,more » on average, between 60% and 99% of their annual load. However, roughly 65% of a typical customer's electricity demand is non-coincidental with PV generation, so the typical PV customer is generally highly reliant on the grid for pooling services.« less

A BRST gauge-fixing procedure for Yang Mills theory on sphere

NASA Astrophysics Data System (ADS)

Banerjee, Rabin; Deguchi, Shinichi

2006-01-01

A gauge-fixing procedure for the Yang-Mills theory on an n-dimensional sphere (or a hypersphere) is discussed in a systematic manner. We claim that Adler's gauge-fixing condition used in massless Euclidean QED on a hypersphere is not conventional because of the presence of an extra free index, and hence is unfavorable for the gauge-fixing procedure based on the BRST invariance principle (or simply BRST gauge-fixing procedure). Choosing a suitable gauge condition, which is proved to be equivalent to a generalization of Adler's condition, we apply the BRST gauge-fixing procedure to the Yang-Mills theory on a hypersphere to obtain consistent results. Field equations for the Yang-Mills field and associated fields are derived in manifestly O (n + 1) covariant or invariant forms. In the large radius limit, these equations reproduce the corresponding field equations defined on the n-dimensional flat space.

FFAGs: Front-end for neutrino factories and medical accelerators

NASA Astrophysics Data System (ADS)

Mori, Yoshiharu

The idea of Fixed Field Alternating Gradient (FFAG) accelerator was originated by different people and groups in the early 1950s. It was independently introduced by Ohkawa [Ohkawa (1953)], Symon et al. [Symon et al. (1956)], and Kolomensky [Kolomensky and Lebedev (1966)] when the strong Alternate Gradient (AG) focusing and the phase stability schemes were applied to particle acceleration. The first FFAG electron model was developed in the MURA accelerator project led by Kerst and Cole in the late 1950s. Since then, they have fabricated several electron models in the early 1960s [Symon et al. (1956)]. However, the studies did not lead to a single practical FFAG accelerator for the following 50 years. Because of the difficulties of treating non-linear magnetic field and RF acceleration for non-relativistic particles, the proton FFAG, especially, was not accomplished until recently. In 2000, the FFAG concept was revived with the world's first proton FFAG (POP) which was developed at KEK [Aiba (2000); Mori (1999)]. Since then, in many places [Berg (2004); Johnstone et al. (2004); Mori (2011); Ruggiero (2004); Trbojevic (2004)], FFAGs have been developed and constructed...

eLISA Telescope In-field Pointing and Scattered Light Study

NASA Astrophysics Data System (ADS)

Livas, J.; Sankar, S.; West, G.; Seals, L.; Howard, J.; Fitzsimons, E.

2017-05-01

The orbital motion of the three spacecraft that make up the eLISA Observatory constellation causes long-arm line of sight variations of approximately ± one degree over the course of a year. The baseline solution is to package the telescope, the optical bench, and the gravitational reference sensor (GRS) into an optical assembly at each end of the measurement arm, and then to articulate the assembly. An optical phase reference is exchanged between the moving optical benches with a single mode optical fiber (“backlink” fiber). An alternative solution, referred to as in-field pointing, embeds a steering mirror into the optical design, fixing the optical benches and eliminating the backlink fiber, but requiring the additional complication of a two-stage optical design for the telescope. We examine the impact of an in-field pointing design on the scattered light performance.

Compactification and inflation in the superstring theory from the condensation of gravitino pairs

NASA Astrophysics Data System (ADS)

Pollock, M. D.

1987-12-01

We discuss the possibility that inflation can occur in the E8×E8' heterotic superstring theory, if there is a pair condensation of the gravitino field ψA and also of the Majorana-Weyl spinor λ, as suggested by the Helayël-Neto and Smith. In the absence of a condensation of the anti-symmetric tensor field HMNP, then the associated potential V(θ,φ) is bounded from below and independent of the dilaton field φ. It can be made to vanish at the minimum, where the compactification scale θ is fixed. Alternatively, a small cosmological constant may remain (ultimately to be cancelled by radiative corrections at the lower energy scale of the gaugino condensation), which could in principle lead to inflation. Present address: Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Bombay 400 005, India.

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

Ju, N; Chen, C; Gans, S

Purpose: A fixed-beam room could be underutilized in a multi-room proton center. We investigated the use of proton pencil beam scanning (PBS) on a fixed-beam as an alternative for posterior fossa tumor bed (PF-TB) boost treatments which were usually treating on a gantry with uniform scanning. Methods: Five patients were treated with craniospinal irradiation (CSI, 23.4 or 36.0 Gy(RBE)) followed by a PF-TB boost to 54 Gy(RBE) with proton beams. Three PF-TB boost plans were generated for each patient: (1) a uniform scanning (US) gantry plan with 4–7 posterior fields shaped with apertures and compensators (2) a PBS plan usingmore » bi-lateral and vertex fields with a 3-mm planning organ-at-risk volume (PRV) expansion around the brainstem and (3) PBS fields using same beam arrangement but replacing the PRV with robust optimization considering a 3-mm setup uncertainty. Results: A concave 54-Gy(RBE) isodose line surrounding the brainstem could be achieved using all three techniques. The mean V95% of the PTV was 99.7% (range: 97.6% to 100%) while the V100% of the PTV ranged from 56.3% to 93.1% depending on the involvement of the brainstem with the PTV. The mean doses received by 0.05 cm{sup 3} of the brainstem were effectively identical: 54.0 Gy(RBE), 53.4 Gy(RBE) and 53.3 Gy(RBE) for US, PBS optimized with PRV, and PBS optimized with robustness plans respectively. The cochlea mean dose increased by 23% of the prescribed boost dose in average from the bi-lateral fields used in the PBS plan. Planning time for the PBS plan with PRV was 5–10 times less than the US plan and the robustly optimized PBS plan. Conclusion: We have demonstrated that a fixed-beam with PBS can deliver a dose distribution comparable to a gantry plan using uniform scanning. Planning time can be reduced substantially using a PRV around the brainstem instead of robust optimization.« less

Donation return time at fixed and mobile donation sites

PubMed Central

Carey, Patricia M.; High, Patrick M.; Schlumpf, Karen S.; Johnson, Bryce R.; Mast, Alan E.; Rios, Jorge A.; Simon, Toby L.; Wilkinson, Susan L.

2013-01-01

BACKGROUND This study investigated the effect of blood donation environment, fixed or mobile with differing sponsor types, on donation return time. STUDY DESIGN AND METHODS Data from 2006 through 2009 at six US blood centers participating in the Retrovirus Epidemiology Donor Study-II (REDS-II) were used for analysis. Descriptive statistics stratified by whole blood (WB), plateletpheresis (PP), and double red blood cell (R2) donations were obtained for fixed and mobile locations, including median number of donations and median interdonation interval. A survival analysis estimated median return time at fixed and mobile sites, while controlling for censored return times, demographics, blood center, and mandatory recovery times. RESULTS Two-thirds (67.9%) of WB donations were made at mobile sites, 97.4% of PP donations were made at fixed sites, and R2 donations were equally distributed between fixed and mobile locations. For donations at fixed sites only or alternating between fixed and mobile sites, the highest median numbers of donations were nine and eight, respectively, and the shortest model-adjusted median return times (controlling for mandatory eligibility times of 56 and 112 days) were 36 and 30 days for WB and R2 donations, respectively. For PP donations, the shortest model-adjusted median return time was 23 days at a fixed location and the longest was 693 days at community locations. CONCLUSION WB, PP, and R2 donors with the shortest time between donations were associated with fixed locations and those alternating between fixed and mobile locations, even after controlling for differing mandatory recovery times for the different blood donation procedures. PMID:21745215

The Dominance Concept Inventory: A Tool for Assessing Undergraduate Student Alternative Conceptions about Dominance in Mendelian and Population Genetics.

PubMed

Abraham, Joel K; Perez, Kathryn E; Price, Rebecca M

2014-01-01

Despite the impact of genetics on daily life, biology undergraduates understand some key genetics concepts poorly. One concept requiring attention is dominance, which many students understand as a fixed property of an allele or trait and regularly conflate with frequency in a population or selective advantage. We present the Dominance Concept Inventory (DCI), an instrument to gather data on selected alternative conceptions about dominance. During development of the 16-item test, we used expert surveys (n = 12), student interviews (n = 42), and field tests (n = 1763) from introductory and advanced biology undergraduates at public and private, majority- and minority-serving, 2- and 4-yr institutions in the United States. In the final field test across all subject populations (n = 709), item difficulty ranged from 0.08 to 0.84 (0.51 ± 0.049 SEM), while item discrimination ranged from 0.11 to 0.82 (0.50 ± 0.048 SEM). Internal reliability (Cronbach's alpha) was 0.77, while test-retest reliability values were 0.74 (product moment correlation) and 0.77 (intraclass correlation). The prevalence of alternative conceptions in the field tests shows that introductory and advanced students retain confusion about dominance after instruction. All measures support the DCI as a useful instrument for measuring undergraduate biology student understanding and alternative conceptions about dominance. © 2014 J. K. Abraham et al. CBE—Life Sciences Education © 2014 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Eye Movements in Darkness Modulate Self-Motion Perception.

PubMed

Clemens, Ivar Adrianus H; Selen, Luc P J; Pomante, Antonella; MacNeilage, Paul R; Medendorp, W Pieter

2017-01-01

During self-motion, humans typically move the eyes to maintain fixation on the stationary environment around them. These eye movements could in principle be used to estimate self-motion, but their impact on perception is unknown. We had participants judge self-motion during different eye-movement conditions in the absence of full-field optic flow. In a two-alternative forced choice task, participants indicated whether the second of two successive passive lateral whole-body translations was longer or shorter than the first. This task was used in two experiments. In the first ( n = 8), eye movements were constrained differently in the two translation intervals by presenting either a world-fixed or body-fixed fixation point or no fixation point at all (allowing free gaze). Results show that perceived translations were shorter with a body-fixed than a world-fixed fixation point. A linear model indicated that eye-movement signals received a weight of ∼25% for the self-motion percept. This model was independently validated in the trials without a fixation point (free gaze). In the second experiment ( n = 10), gaze was free during both translation intervals. Results show that the translation with the larger eye-movement excursion was judged more often to be larger than chance, based on an oculomotor choice probability analysis. We conclude that eye-movement signals influence self-motion perception, even in the absence of visual stimulation.

Eye Movements in Darkness Modulate Self-Motion Perception

PubMed Central

Pomante, Antonella

2017-01-01

Abstract During self-motion, humans typically move the eyes to maintain fixation on the stationary environment around them. These eye movements could in principle be used to estimate self-motion, but their impact on perception is unknown. We had participants judge self-motion during different eye-movement conditions in the absence of full-field optic flow. In a two-alternative forced choice task, participants indicated whether the second of two successive passive lateral whole-body translations was longer or shorter than the first. This task was used in two experiments. In the first (n = 8), eye movements were constrained differently in the two translation intervals by presenting either a world-fixed or body-fixed fixation point or no fixation point at all (allowing free gaze). Results show that perceived translations were shorter with a body-fixed than a world-fixed fixation point. A linear model indicated that eye-movement signals received a weight of ∼25% for the self-motion percept. This model was independently validated in the trials without a fixation point (free gaze). In the second experiment (n = 10), gaze was free during both translation intervals. Results show that the translation with the larger eye-movement excursion was judged more often to be larger than chance, based on an oculomotor choice probability analysis. We conclude that eye-movement signals influence self-motion perception, even in the absence of visual stimulation. PMID:28144623

SU-E-J-187: Management of Optic Organ Motion in Fractionated Stereotactic Radiotherapy

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

Manning, M; Maurer, J

2015-06-15

Purpose: Fractionated stereotactic radiotherapy (FSRT) for optic nerve tumors can potentially use planning target volume (PTV) expansions as small as 1–5 mm. However, the motion of the intraorbital segment of the optic nerve has not been studied. Methods: A subject with a right optic nerve sheath meningioma underwent CT simulation in three fixed gaze positions: right, left, and fixed forward at a marker. The gross tumor volume (GTV) and the organs-at-risk (OAR) were contoured on all three scans. An IMRT plan using 10 static non-coplanar fields to 50.4 Gy in 28 fractions was designed to treat the fixed-forward gazing GTVmore » with a 1 mm PTV, then resulting coverage was evaluated for the GTV in the three positions. As an alternative, the composite structures were computed to generate the internal target volume (ITV), 1 mm expansion free-gazing PTV, and planning organat-risk volumes (PRVs) for free-gazing treatment. A comparable IMRT plan was created for the free-gazing PTV. Results: If the patient were treated using the fixed forward gaze plan looking straight, right, and left, the V100% for the GTV was 100.0%, 33.1%, and 0.1%, respectively. The volumes of the PTVs for fixed gaze and free-gazing plans were 0.79 and 2.21 cc, respectively, increasing the PTV by a factor of 2.6. The V100% for the fixed gaze and free-gazing plans were 0.85 cc and 2.8 cc, respectively increasing the treated volume by a factor of 3.3. Conclusion: Fixed gaze treatment appears to provide greater organ sparing than free-gazing. However unanticipated intrafraction right or left gaze can produce a geometric miss. Further study of optic nerve motion appears to be warranted in areas such as intrafraction optical confirmation of fixed gaze and optimized gaze directions to minimize lens and other normal organ dose in cranial radiotherapy.« less

New geophysical electromagnetic method of archeological object research in Egypt

NASA Astrophysics Data System (ADS)

Hachay, O. A.; Khachay, O. Yu.; Attia, Magdi.

2009-04-01

The demand to the enhanced geophysical technique and device, in addition to the precise interpretation of the geophysical data, is the resolution of the geophysical complex research, especially by the absence of priory information about the researched place. Therefore, an approach to use the planshet method of electromagnetic induction in the frequency geometry was developed by Hachay. et al., 1997a, 1997b, 1999, 2000, 2002, and 2005. The method was adapted to map and monitor the high complicated geological mediums, to determine the structural factors and criteria of the rock massif in the mine subsurface. The field observation and the way of interpretation make the new technology differ from other known earlier methods of field raying or tomography (Hachay et al., 1997c, 1999, and 2000).The 3D geoelectrical medium research is based on the concept of three staged interpreting of the alternating electromagnetic field in a frame of the block-layered isotropic medium with inclusion (Hachay 1997a, and 2002); in the first stage, the geoelectrical parameters of the horizontal block-layered medium, which includes the heterogeneities, are defined. In the second stage a geometrical model of the different local heterogeneities or groups inside the block-layered medium is constructed based on the local geoelectrical heterogeneities produced from the first stage after filtering the anomalous fields plunged in the medium. While in the third stage, the surfaces of the searched heterogeneities could be calculated in account of the physical parameters of the anomalous objects.For practical realization of that conception the system of observation for alternating electromagnetic field with use of vertical magnetic dipole was elaborated. Such local source of excitation and regular net of observations allows realizing overlapping by different angles of observation directions. As incoming data for interpretation, three components of modules of three components of magnetic field are used. For the case on surface observations the data are measured on the Earth's surface at the set of distances between the source and receiver as a function of frequencies. The measurements of the module of three components of the magnetic field vertical and two horizontal: one directed to the source and second perpendicular to that direction are provided in the frame of planshet for the fixed net with fixed step and fixed length of the planshet's side. In the frame of profile observations the planshet become to a band or a line and the length of the band or the line is a base of observations or an array. For the variant of the wide profile (band) the source of excitation is located at the beginning of the array on the profile, which is parallel to the measuring profile. We shall call that a wide array. It moves systematically with a fixed step of meters. For the variant of an usual profile the source is located on the measuring profile and the moving of the oscillator is similar. For the variant of a planshet survey the source is located into the center of the planshet using the fixed net of observation. Then the planshet array moves systematically with overlapping usually on the half of the planshet.The interpretation is made in a frame of n-layered model for each array and planshet location. After that each point of the planshet is associated with one and only column of layers thicknesses and corresponding fixed column with resistance of the medium in that layers. Gathering information of all planshets together we obtain a many-valued function of each point - distribution of thicknesses and resistances of the medium layers. Then we calculate the average value for these distributions for each point of the observation set. Thus we obtain the unique distribution of thicknesses of horizontal layers and resistances, which corresponds to the medium model as a cylinder with vertical generatrixes and with a rectangle at the bottom and with a point of observation located in its center. Thus we change over layered model to a block-layered model. Then, gathering the values of thicknesses and resistances for all points of observation, located on one and the same profile we obtain the file of an average cross-section along the profile.The next step is combining the neighboring blocks with close-range values of resistance to one block. That operation is made according to the fixed scale of resistance. The second stage of interpretation is used to define the geometrical characteristics of conductive inclusions and their equivalent moments, which are proportional to the ratio of the conductivity difference in the host rock and in the inclusion to the conductivity in the host rock. Here the approximation principle is used for alternating electromagnetic fields. The initial model of the inclusion is a current line of fixed length. That approximation construction is used for fitting of the average parameter of geoelectrical heterogeneity, which is calculated and located to each point of the profile (Hachay O.A. et all. 2002).The first problem: to found the tomb of Ptolemey in Alexandria. That work is provided by NRIAG together with the Aphine University. The historical and archeological work was provided during a long time. In that moment when we had been asked to do our research on that object it must be needed to show more precisely the place of that tomb on the territory of the ancient royal garden in Alexandria. NRIAG had developed electro prospecting works using radar and vertical electric soundings. With use of our results on the archeological object it had been choose a more precise place for the borehole and for next excavation. The results of drilling showed, as it was forecasted, that from the depth 7m on the showed picket of the observed profile it had been revealed stone objects which differ from the limestones sandstones. The drilling was achieved on 20-th of april 2008.

Alternating-gradient canted cosine theta superconducting magnets for future compact proton gantries

DOE PAGES

Wan, Weishi; Brouwer, Lucas; Caspi, Shlomo; ...

2015-10-23

We present a design of superconducting magnets, optimized for application in a gantry for proton therapy. We have introduced a new magnet design concept, called an alternating-gradient canted cosine theta (AG-CCT) concept, which is compatible with an achromatic layout. This layout allows a large momentum acceptance. The 15 cm radius of the bore aperture enables the application of pencil beam scanning in front of the SC-magnet. The optical and dynamic performance of a gantry based on these magnets has been analyzed using the fields derived (via Biot-Savart law) from the actual windings of the AG-CCT combined with the full equationsmore » of motion. The results show that with appropriate higher order correction, a large 3D volume can be rapidly scanned with little beam shape distortion. A very big advantage is that all this can be done while keeping the AG-CCT fields fixed. This reduces the need for fast field ramping of the superconducting magnets between the successive beam energies used for the scanning in depth and it is important for medical application since this reduces the technical risk (e.g., a quench) associated with fast field changes in superconducting magnets. For proton gantries the corresponding superconducting magnet system holds promise of dramatic reduction in weight. For heavier ion gantries there may furthermore be a significant reduction in size.« less

Alternating-gradient canted cosine theta superconducting magnets for future compact proton gantries

NASA Astrophysics Data System (ADS)

Wan, Weishi; Brouwer, Lucas; Caspi, Shlomo; Prestemon, Soren; Gerbershagen, Alexander; Schippers, Jacobus Maarten; Robin, David

2015-10-01

We present a design of superconducting magnets, optimized for application in a gantry for proton therapy. We have introduced a new magnet design concept, called an alternating-gradient canted cosine theta (AG-CCT) concept, which is compatible with an achromatic layout. This layout allows a large momentum acceptance. The 15 cm radius of the bore aperture enables the application of pencil beam scanning in front of the SC-magnet. The optical and dynamic performance of a gantry based on these magnets has been analyzed using the fields derived (via Biot-Savart law) from the actual windings of the AG-CCT combined with the full equations of motion. The results show that with appropriate higher order correction, a large 3D volume can be rapidly scanned with little beam shape distortion. A very big advantage is that all this can be done while keeping the AG-CCT fields fixed. This reduces the need for fast field ramping of the superconducting magnets between the successive beam energies used for the scanning in depth and it is important for medical application since this reduces the technical risk (e.g., a quench) associated with fast field changes in superconducting magnets. For proton gantries the corresponding superconducting magnet system holds promise of dramatic reduction in weight. For heavier ion gantries there may furthermore be a significant reduction in size.

Navy applications experience with small wind power systems

NASA Astrophysics Data System (ADS)

Pal, D.

1985-05-01

This report describes the experience gained and lesson learned from the ongoing field evaluations of seven small, 2-to 20-kW wind energy conversion systems (WECS) at Navy installations located in the Southern California desert, on San Nicolas Island, in California, and in Kaneohe Bay, Hawaii. The field tests show that the WECS's bearings and yaw slip-rings are prone to failure. The failures were attributed to the corrosive environment and poor design practices. Based upon the field tests, it is concluded that a reliable WECS must use a permanent magnet alternator without a gearbox and yaw slip-rings that are driven by a fixed pitch wind turbine rotor. The present state-of-the-art in small WECS technology, including environmental concerns, is reviewed. Also presented is how the technology is advancing to improve reliability and availability for effectively using wind power at Navy bases. The field evaluations are continuing on the small WECS in order to develop operation, maintenance, and reliability data.

Newly velocity field of Sulawesi Island from GPS observation

NASA Astrophysics Data System (ADS)

Sarsito, D. A.; Susilo, Simons, W. J. F.; Abidin, H. Z.; Sapiie, B.; Triyoso, W.; Andreas, H.

2017-07-01

Sulawesi microplate Island is located at famous triple junction area of the Eurasian, India-Australian, and Philippine Sea plates. Under the influence of the northward moving Australian plate and the westward motion of the Philippine plate, the island at Eastern part of Indonesia is collide and with the Eurasian plate and Sunda Block. Those recent microplate tectonic motions can be quantitatively determine by GNSS-GPS measurement. We use combine GNSS-GPS observation types (campaign type and continuous type) from 1997 to 2015 to derive newly velocity field of the area. Several strategies are applied and tested to get the optimum result, and finally we choose regional strategy to reduce error propagation contribution from global multi baseline processing using GAMIT/GLOBK 10.5. Velocity field are analyzed in global reference frame ITRF 2008 and local reference frame by fixing with respect alternatively to Eurasian plate - Sunda block, India-Australian plate and Philippine Sea plates. Newly results show dense distribution of velocity field. This information is useful for tectonic deformation studying in geospatial era.

78 FR 29063 - Survey of Urban Rates for Fixed Voice and Fixed Broadband Residential Services

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-17

... in alternative formats (computer diskette, large print, audio record, and Braille). Persons with... Company Name: Provider FRN (used on MONTH DAY, YEAR Form 477): Provider Study Area Code (if current USF...

Nitrogen isotope fractionation by alternative nitrogenases and past ocean anoxia

PubMed Central

Zhang, Xinning; Sigman, Daniel M.; Morel, François M. M.; Kraepiel, Anne M. L.

2014-01-01

Biological nitrogen fixation constitutes the main input of fixed nitrogen to Earth’s ecosystems, and its isotope effect is a key parameter in isotope-based interpretations of the N cycle. The nitrogen isotopic composition (δ15N) of newly fixed N is currently believed to be ∼–1‰, based on measurements of organic matter from diazotrophs using molybdenum (Mo)-nitrogenases. We show that the vanadium (V)- and iron (Fe)-only “alternative” nitrogenases produce fixed N with significantly lower δ15N (–6 to –7‰). An important contribution of alternative nitrogenases to N2 fixation provides a simple explanation for the anomalously low δ15N (<–2‰) in sediments from the Cretaceous Oceanic Anoxic Events and the Archean Eon. A significant role for the alternative nitrogenases over Mo-nitrogenase is also consistent with evidence of Mo scarcity during these geologic periods, suggesting an additional dimension to the coupling between the global cycles of trace elements and nitrogen. PMID:24639508

Pathobiological investigation of naturally infected canine rabies cases from Sri Lanka.

PubMed

Beck, S; Gunawardena, P; Horton, D L; Hicks, D J; Marston, D A; Ortiz-Pelaez, A; Fooks, A R; Núñez, A

2017-04-12

The recommended screening of rabies in 'suspect' animal cases involves testing fresh brain tissue. The preservation of fresh tissue however can be difficult under field conditions and formalin fixation provides a simple alternative that may allow a confirmatory diagnosis. The occurrence and location of histopathological changes and immunohistochemical (IHC) labelling for rabies in formalin fixed paraffin embedded (FFPE) canine brain is described in samples from 57 rabies suspect cases from Sri-Lanka. The presence of Negri bodies and immunohistochemical detection of rabies virus antigen were evaluated in the cortex, hippocampus, cerebellum and brainstem. The effect of autolysis and artefactual degeneration of the tissue was also assessed. Rabies was confirmed in 53 of 57 (93%) cases by IHC. IHC labelling was statistically more abundant in the brainstem. Negri bodies were observed in 32 of 53 (60.4%) of the positive cases. Although tissue degradation had no effect on IHC diagnosis, it was associated with an inability to detect Negri bodies. In 13 cases, a confirmatory Polymerase chain reaction (PCR) testing for rabies virus RNA was undertaken by extracting RNA from fresh frozen tissue, and also attempted using FFPE samples. PCR detection using fresh frozen samples was in agreement with the IHC results. The PCR method from FFPE tissues was suitable for control material but unsuccessful in our field cases. Histopathological examination of the brain is essential to define the differential diagnoses of behaviour modifying conditions in rabies virus negative cases, but it is unreliable as the sole method for rabies diagnosis, particularly where artefactual change has occurred. Formalin fixation and paraffin embedding does not prevent detection of rabies virus via IHC labelling even where artefactual degeneration has occurred. This could represent a pragmatic secondary assay for rabies diagnosis in the field because formalin fixation can prevent sample degeneration. The brain stem was shown to be the site with most viral immunoreactivity; supporting recommended sampling protocols in favour of improved necropsy safety in the field. PCR testing of formalin fixed tissue may be successful in certain circumstances as an alternative test.

The use of optical pyrometers in axial flow turbines

NASA Astrophysics Data System (ADS)

Sellers, R. R.; Przirembel, H. R.; Clevenger, D. H.; Lang, J. L.

1989-07-01

An optical pyrometer system that can be used to measure metal temperatures over an extended range of temperature has been developed. Real-time flame discrimination permits accurate operation in the gas turbine environment with high flame content. This versatile capability has been used in a number of ways. In experimental engines, a fixed angle pyrometer has been used for turbine health monitoring for the automatic test stand abort system. Turbine blade creep capability has been improved by tailoring the burner profile based on measured blade temperatures. Fixed and traversing pyrometers were used extensively during engine development to map blade surface temperatures in order to assess cooling effectiveness and identify optimum configurations. Portable units have been used in turbine field inspections. A new low temperature pyrometer is being used as a diagnostic tool in the alternate turbopump design for the Space Shuttle main engine. Advanced engine designs will incorporate pyrometers in the engine control system to limit operation to safe temperatures.

Alternative medicine complements standard. Various forms focus on holistic concepts.

PubMed

Seaward, B L

1994-09-01

Western or conventional medical practices are founded on the principle of Newtonian physics; the body is viewed as a large clock whose broken parts are fixed or replaced. The placebo effect, hypnosis, psychoneuroimmunology, and spontaneous remission have recently inspired researchers to look beyond this mechanistic model toward a new paradigm of greater understanding regarding the entity we call "human beings." The premise of alternative medicine, based on the paradigm of whole systems, suggests that human beings are more than physical bodies with fixable and replaceable parts; they are a complicated network of pulsating energy frequencies often described in terms of a human aura. Western researchers now call this "the human energy field." Homeopathy, acupuncture, polarity healing, and the healing power of touch are only a few of the more common branches of holistic medicine that unite body, mind, and spirit for optimal health. The U.S. Congress has appropriated more than $2 million to the National Institutes of Health to research the validity of alternative or complementary medicines. In light of proposed changes in the healthcare system, alternative medicine may eventually be incorporated into the American structure of healthcare delivery. Proponents of holistic medicine agree that various forms of alternative medicine should be used to complement, rather than compete, with, the current accepted standard of healthcare.

Periodic magnetic field as a polarized and focusing thermal neutron spectrometer and monochromator.

PubMed

Cremer, J T; Williams, D L; Fuller, M J; Gary, C K; Piestrup, M A; Pantell, R H; Feinstein, J; Flocchini, R G; Boussoufi, M; Egbert, H P; Kloh, M D; Walker, R B

2010-01-01

A novel periodic magnetic field (PMF) optic is shown to act as a prism, lens, and polarizer for neutrons and particles with a magnetic dipole moment. The PMF has a two-dimensional field in the axial direction of neutron propagation. The PMF alternating magnetic field polarity provides strong gradients that cause separation of neutrons by wavelength axially and by spin state transversely. The spin-up neutrons exit the PMF with their magnetic spins aligned parallel to the PMF magnetic field, and are deflected upward and line focus at a fixed vertical height, proportional to the PMF period, at a downstream focal distance that increases with neutron energy. The PMF has no attenuation by absorption or scatter, as with material prisms or crystal monochromators. Embodiments of the PMF include neutron spectrometer or monochromator, and applications include neutron small angle scattering, crystallography, residual stress analysis, cross section measurements, and reflectometry. Presented are theory, experimental results, computer simulation, applications of the PMF, and comparison of its performance to Stern-Gerlach gradient devices and compound material and magnetic refractive prisms.

Periodic magnetic field as a polarized and focusing thermal neutron spectrometer and monochromator

PubMed Central

Cremer, J. T.; Williams, D. L.; Fuller, M. J.; Gary, C. K.; Piestrup, M. A.; Pantell, R. H.; Feinstein, J.; Flocchini, R. G.; Boussoufi, M.; Egbert, H. P.; Kloh, M. D.; Walker, R. B.

2010-01-01

A novel periodic magnetic field (PMF) optic is shown to act as a prism, lens, and polarizer for neutrons and particles with a magnetic dipole moment. The PMF has a two-dimensional field in the axial direction of neutron propagation. The PMF alternating magnetic field polarity provides strong gradients that cause separation of neutrons by wavelength axially and by spin state transversely. The spin-up neutrons exit the PMF with their magnetic spins aligned parallel to the PMF magnetic field, and are deflected upward and line focus at a fixed vertical height, proportional to the PMF period, at a downstream focal distance that increases with neutron energy. The PMF has no attenuation by absorption or scatter, as with material prisms or crystal monochromators. Embodiments of the PMF include neutron spectrometer or monochromator, and applications include neutron small angle scattering, crystallography, residual stress analysis, cross section measurements, and reflectometry. Presented are theory, experimental results, computer simulation, applications of the PMF, and comparison of its performance to Stern–Gerlach gradient devices and compound material and magnetic refractive prisms. PMID:20113108

Fixed-Charge Atomistic Force Fields for Molecular Dynamics Simulations in the Condensed Phase: An Overview.

PubMed

Riniker, Sereina

2018-03-26

In molecular dynamics or Monte Carlo simulations, the interactions between the particles (atoms) in the system are described by a so-called force field. The empirical functional form of classical fixed-charge force fields dates back to 1969 and remains essentially unchanged. In a fixed-charge force field, the polarization is not modeled explicitly, i.e. the effective partial charges do not change depending on conformation and environment. This simplification allows, however, a dramatic reduction in computational cost compared to polarizable force fields and in particular quantum-chemical modeling. The past decades have shown that simulations employing carefully parametrized fixed-charge force fields can provide useful insights into biological and chemical questions. This overview focuses on the four major force-field families, i.e. AMBER, CHARMM, GROMOS, and OPLS, which are based on the same classical functional form and are continuously improved to the present day. The overview is aimed at readers entering the field of (bio)molecular simulations. More experienced users may find the comparison and historical development of the force-field families interesting.

75 FR 24930 - Fort Bliss (Texas) Army Growth and Force Structure Realignment Final Environmental Impact...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-06

... effects that would result from use of stationing and training capacity, land use changes, and training... 4 stationing action; Alternative 5 land use change; and Alternative 4 training infrastructure... stationing package. Alternative 5 land use changes allow fixed sites (e.g., military bivouac), mission...

Migration of cell surface concanavalin A receptors in pulsed electric fields.

PubMed Central

Lin-Liu, S; Adey, W R; Poo, M M

1984-01-01

Concanavalin A (con A) receptors on the surface of cultured Xenopus myoblasts redistributed in response to monopolar, pulsed electric fields. The prefield uniform distribution of the receptors became asymmetrical, and was polarized toward the cathodal pole, in the same way as in DC fields. The extent of asymmetry depended on the duration of field exposure, pulse width (or alternatively, interpulse interval), frequency, and intensity. This relationship was most conveniently expressed by using duty cycle, a quantity determined by both pulse width and frequency. Pulses of average intensity 1.5 V/cm induced detectable asymmetry within 5 min. At the lowest average field intensity used, 0.8 V/cm, significant asymmetry was detected at 150 min. For pulses of high duty cycle (greater than 25%), steady state was reached after 30 min exposure and the steady state asymmetry was dependent on average field intensity. For low duty cycle fields, the time required to reach steady state was prolonged (greater than 50 min). Before reaching a steady state, effectiveness of the pulses, as compared with DC fields of equivalent intensity, was a function of duty cycle. A low duty cycle field (fixed number of pulses at low frequency or long interpulse interval) was less effective than high duty cycle fields or DC. PMID:6743751

Duality for massive spin two theories in arbitrary dimensions

NASA Astrophysics Data System (ADS)

González, B.; Khoudeir, A.; Montemayor, R.; Urrutia, L. F.

2008-09-01

Using the parent Lagrangian approach we construct a dual formulation, in the sense originally proposed by Curtright and Freund, of a massive spin two Fierz-Pauli theory in arbitrary dimensions D. This is achieved in terms of a mixed symmetry tensor TA[B1B2...BD-2], without the need of auxiliary fields. The relation of this method with an alternative formulation based on a gauge symmetry principle proposed by Zinoviev is elucidated. We show that the latter formulation in four dimensions, with a given gauge fixing together with a definite sequence of auxiliary fields elimination via their equations of motion, leads to the parent Lagrangian already considered by West completed by a Fierz-Pauli mass term, which in turns yields the Curtright-Freund action. This motivates our generalization to arbitrary dimensions leading to the corresponding extension of the four dimensional result. We identify the transverse true degrees of freedom of the dual theory and verify that their number is in accordance with those of the massive Fierz-Pauli field.

Comparative analysis of Trichuris muris surface using conventional, low vacuum, environmental and field emission scanning electron microscopy.

PubMed

Lopes Torres, Eduardo José; de Souza, Wanderley; Miranda, Kildare

2013-09-23

The whipworm of the genus Trichuris Roederer, 1791, is a nematode of worldwide distribution and comprises species that parasitize humans and other mammals. Infections caused by Trichuris spp. in mammals can lead to various intestinal diseases of human and veterinary interest. The morphology of Trichuris spp. and other helminths has been mostly studied using conventional scanning electron microscopy of chemically fixed, dried and metal-coated specimens, although this kind of preparation has been shown to introduce a variety of artifacts such as sample shrinking, loss of secreted products and/or hiding of small structures due to sample coating. Low vacuum (LVSEM) and environmental scanning electron microscopy (ESEM) have been applied to a variety of insulator samples, also used in the visualization of hydrated and/or live specimens in their native state. In the present work, we used LVSEM and ESEM to analyze the surface of T. muris and analyze its interaction with the host tissue using freshly fixed or unfixed hydrated samples. Analysis of hydrated samples showed a set of new features on the surface of the parasite and the host tissue, including the presence of the secretory products of the bacillary glands on the surface of the parasite, and the presence of mucous material and eggs on the intestinal surface. Field emission scanning electron microscopy (FESEM) was also applied to reveal the detailed structure of the glandular chambers in fixed, dried and metal coated samples. Taken together, the results show that analysis of hydrated samples may provide new insights in the structural organization of the surface of helminth parasites and its interaction with the infected tissue, suggesting that the application of alternative SEM techniques may open new perspectives for analysis in taxonomy, morphology and host-parasite interaction fields. Copyright © 2013 Elsevier B.V. All rights reserved.

Application of alternative fixatives to formalin in diagnostic pathology

PubMed Central

Gatta, L. Benerini; Cadei, M.; Balzarini, P.; Castriciano, S.; Paroni, R.; Verzeletti, A.; Cortellini, V.; De Ferrari, F.; Grigolato, P.

2012-01-01

Fixation is a critical step in the preparation of tissues for histopathology. The aim of this study was to investigate the effects of different fixatives vs formalin on proteins and DNA, and to evaluate alternative fixation for morphological diagnosis and nucleic acid preservation for molecular methods. Forty tissues were fixed for 24 h with six different fixatives: the gold standard fixative formalin, the historical fixatives Bouin and Hollande, and the alternative fixatives Greenfix, UPM and CyMol. Tissues were stained (Haematoxylin-Eosin, Periodic Acid Schiff, Trichromic, Alcian-blue, High Iron Diamine stainings), and their antigenicity was determined by immunohistochemistry (performed with PAN-CK, CD31, Ki-67, S100, CD68, AML antibodies). DNA extraction, KRAS sequencing, FISH for CEP-17, and flow cytometry analysis of nuclear DNA content were applied. For cell morphology the alternative fixatives (Greenfix, UPM, CyMol) were equivalent to formalin. As expected, Hollande proved to be the best fixative for morphology. The morphology obtained with Bouin was comparable to the one with formalin. Hollande was the best fixative for histochemistry. Bouin proved to be equivalent to formalin. The alternative fixatives were equivalent to formalin, although with greater variability in haematoxylin-eosin staining. It proved the possibility to obtain immunohistochemical staining largely equivalent to that following formalin-fixation with the following fixatives: Greenfix, Hollande, UPM and CyMol. The tissues fixed in Bouin did not provide results comparable to those obtained with formalin. The DNA extracted from samples fixed with alternative fixatives was found to be suitable for molecular analysis. PMID:22688293

A new approach to blind deconvolution of astronomical images

NASA Astrophysics Data System (ADS)

Vorontsov, S. V.; Jefferies, S. M.

2017-05-01

We readdress the strategy of finding approximate regularized solutions to the blind deconvolution problem, when both the object and the point-spread function (PSF) have finite support. Our approach consists in addressing fixed points of an iteration in which both the object x and the PSF y are approximated in an alternating manner, discarding the previous approximation for x when updating x (similarly for y), and considering the resultant fixed points as candidates for a sensible solution. Alternating approximations are performed by truncated iterative least-squares descents. The number of descents in the object- and in the PSF-space play a role of two regularization parameters. Selection of appropriate fixed points (which may not be unique) is performed by relaxing the regularization gradually, using the previous fixed point as an initial guess for finding the next one, which brings an approximation of better spatial resolution. We report the results of artificial experiments with noise-free data, targeted at examining the potential capability of the technique to deconvolve images of high complexity. We also show the results obtained with two sets of satellite images acquired using ground-based telescopes with and without adaptive optics compensation. The new approach brings much better results when compared with an alternating minimization technique based on positivity-constrained conjugate gradients, where the iterations stagnate when addressing data of high complexity. In the alternating-approximation step, we examine the performance of three different non-blind iterative deconvolution algorithms. The best results are provided by the non-negativity-constrained successive over-relaxation technique (+SOR) supplemented with an adaptive scheduling of the relaxation parameter. Results of comparable quality are obtained with steepest descents modified by imposing the non-negativity constraint, at the expense of higher numerical costs. The Richardson-Lucy (or expectation-maximization) algorithm fails to locate stable fixed points in our experiments, due apparently to inappropriate regularization properties.

48 CFR 246.710 - Contract clauses.

Code of Federal Regulations, 2010 CFR

2010-10-01

... contracts that include the clause at 252.227-7013, Rights in Technical Data and Computer Software, when... Alternate I when extended liability is desired and a fixed price incentive contract is contemplated. (3) Use... and a firm fixed price contract is contemplated. (4) Use the clause at 252.246-7002, Warranty of...

Theoretical Comparison of Fixed Route Bus and Flexible Route Subscription Bus Feeder Service in Low Density Areas

DOT National Transportation Integrated Search

1975-03-01

parametric variation of demand density was used to compare service level and cost of two alternative systems for providing low density feeder service. Supply models for fixed route and flexible route service were developed and applied to determine ra...

Spontaneous Lorentz and diffeomorphism violation, massive modes, and gravity

NASA Astrophysics Data System (ADS)

Bluhm, Robert; Fung, Shu-Hong; Kostelecký, V. Alan

2008-03-01

Theories with spontaneous local Lorentz and diffeomorphism violation contain massless Nambu-Goldstone modes, which arise as field excitations in the minimum of the symmetry-breaking potential. If the shape of the potential also allows excitations above the minimum, then an alternative gravitational Higgs mechanism can occur in which massive modes involving the metric appear. The origin and basic properties of the massive modes are addressed in the general context involving an arbitrary tensor vacuum value. Special attention is given to the case of bumblebee models, which are gravitationally coupled vector theories with spontaneous local Lorentz and diffeomorphism violation. Mode expansions are presented in both local and spacetime frames, revealing the Nambu-Goldstone and massive modes via decomposition of the metric and bumblebee fields, and the associated symmetry properties and gauge fixing are discussed. The class of bumblebee models with kinetic terms of the Maxwell form is used as a focus for more detailed study. The nature of the associated conservation laws and the interpretation as a candidate alternative to Einstein-Maxwell theory are investigated. Explicit examples involving smooth and Lagrange-multiplier potentials are studied to illustrate features of the massive modes, including their origin, nature, dispersion laws, and effects on gravitational interactions. In the weak static limit, the massive mode and Lagrange-multiplier fields are found to modify the Newton and Coulomb potentials. The nature and implications of these modifications are examined.

Fixed-angle plate osteosynthesis of the patella - an alternative to tension wiring?

PubMed

Wild, M; Eichler, C; Thelen, S; Jungbluth, P; Windolf, J; Hakimi, M

2010-05-01

The goal of this study is carry out a biomechanical evaluation of the stability of a bilateral, polyaxial, fixed-angle 2.7 mm plate system specifically designed for use on the patella. The results of this approach are then compared to the two currently most commonly used surgical techniques for patella fractures: modified anterior tension wiring with K-wires and cannulated lag screws with anterior tension wiring. A transient biomechanical analysis determining material failure points of all osteosyntheses were conducted on 21 identical left polyurethane foam patellae, which were osteotomized horizontally. Evaluated were load (N), displacement (mm) and run-time (s) as well as elastic modulus (MPa), tensile strength (MPa) and strain at failure (%). With a maximum load capacity of 2396 (SD 492) N, the fixed-angle plate proved to be significantly stronger than the cannulated lag screws with anterior tension wiring (1015 (SD 246) N) and the modified anterior tension wiring (625 (SD 84.9) N). The fixed-angle plate displayed significantly greater stiffness and lower fracture gap dehiscence than the other osteosyntheses. Additionally, osteosynthesis deformation was found to be lower for the fixed-angle plate. A bilateral fixed-angle plate was the most rigid and stable osteosynthesis for horizontal patella fractures with the least amount of fracture gap dehiscence. Further biomechanical trials performed under cycling loading with fresh cadaver specimen should be done to figure out if a fixed-angle plate may be an alternative in the surgical treatment of patella fractures. Copyright 2009 Elsevier Ltd. All rights reserved.

An Investigation of Spontaneous Lorentz Violation and Cosmic Inflation

NASA Astrophysics Data System (ADS)

Tam, Heywood

2010-12-01

In this thesis we re-examine two established ideas in theoretical physics: Lorentz invariance and cosmic inflation. In the first four chapters, we (i) propose a way to hide large extra dimensions by coupling standard model fields with Lorentz-violating tensor fields with expectation values along the extra dimensions; (ii) examine the stability of theories in which Lorentz invariance is spontaneously broken by fixed-norm 'aether' fields; (iii) investigate the phenomenological properties of the sigma-model aether theory; and (iv) explore the implications of an alternative theory of gravity in which the graviton arises from the Goldstone modes of a two-index symmetric aether field. In the final chapter, we examine the horizon and flatness problems using the canonical measure (developed by Gibbons, Hawking, and Stewart) on the space of solutions to Einstein's equations. We find that the flatness problem does not exist, while the homogeneity of our universe does represent a substantial fine-tuning. Based on the assumption of unitary evolution (Liouville's theorem), we further dispute the widely accepted claim that inflation makes our universe more natural.

Attitudes of older adults toward shooter video games: An initial study to select an acceptable game for training visual processing.

PubMed

McKay, Sandra M; Maki, Brian E

2010-01-01

A computer-based 'Useful Field of View' (UFOV) training program has been shown to be effective in improving visual processing in older adults. Studies of young adults have shown that playing video games can have similar benefits; however, these studies involved realistic and violent 'first-person shooter' (FPS) games. The willingness of older adults to play such games has not been established. OBJECTIVES: To determine the degree to which older adults would accept playing a realistic, violent FPS-game, compared to video games not involving realistic depiction of violence. METHODS: Sixteen older adults (ages 64-77) viewed and rated video-clip demonstrations of the UFOV program and three video-game genres (realistic-FPS, cartoon-FPS, fixed-shooter), and were then given an opportunity to try them out (30 minutes per game) and rate various features. RESULTS: The results supported a hypothesis that the participants would be less willing to play the realistic-FPS game in comparison to the less violent alternatives (p's<0.02). After viewing the video-clip demonstrations, 10 of 16 participants indicated they would be unwilling to try out the realistic-FPS game. Of the six who were willing, three did not enjoy the experience and were not interested in playing again. In contrast, all 12 subjects who were willing to try the cartoon-FPS game reported that they enjoyed it and would be willing to play again. A high proportion also tried and enjoyed the UFOV training (15/16) and the fixed-shooter game (12/15). DISCUSSION: A realistic, violent FPS video game is unlikely to be an appropriate choice for older adults. Cartoon-FPS and fixed-shooter games are more viable options. Although most subjects also enjoyed UFOV training, a video-game approach has a number of potential advantages (for instance, 'addictive' properties, low cost, self-administration at home). We therefore conclude that non-violent cartoon-FPS and fixed-shooter video games warrant further investigation as an alternative to the UFOV program for training improved visual processing in seniors.

An improved least cost routing approach for WDM optical network without wavelength converters

NASA Astrophysics Data System (ADS)

Bonani, Luiz H.; Forghani-elahabad, Majid

2016-12-01

Routing and wavelength assignment (RWA) problem has been an attractive problem in optical networks, and consequently several algorithms have been proposed in the literature to solve this problem. The most known techniques for the dynamic routing subproblem are fixed routing, fixed-alternate routing, and adaptive routing methods. The first one leads to a high blocking probability (BP) and the last one includes a high computational complexity and requires immense backing from the control and management protocols. The second one suggests a trade-off between performance and complexity, and hence we consider it to improve in our work. In fact, considering the RWA problem in a wavelength routed optical network with no wavelength converter, an improved technique is proposed for the routing subproblem in order to decrease the BP of the network. Based on fixed-alternate approach, the first k shortest paths (SPs) between each node pair is determined. We then rearrange the SPs according to a newly defined cost for the links and paths. Upon arriving a connection request, the sorted paths are consecutively checked for an available wavelength according to the most-used technique. We implement our proposed algorithm and the least-hop fixed-alternate algorithm to show how the rearrangement of SPs contributes to a lower BP in the network. The numerical results demonstrate the efficiency of our proposed algorithm in comparison with the others, considering different number of available wavelengths.

New horizons in orthodontics & dentofacial orthopedics: fixed Twin Blocks & TransForce lingual appliances.

PubMed

Clark, William John

2011-01-01

During the 20th century functional appliances evolved from night time wear to more flexible appliances for increased day time wear to full time wear with Twin Block appliances. The current trend is towards fixed functional appliances and this paper introduces the Fixed Twin Block, bonded to the teeth to eliminate problems of compliance in functional therapy. TransForce lingual appliances are pre-activated and may be used in first phase treatment for sagittal and transverse arch development. Alternatively they may be integrated with fixed appliances at any stage of treatment.

Fiber-reinforced composite fixed dental prostheses: two clinical reports.

PubMed

Zarow, Maciej; Paisley, Carl Stuart; Krupinski, Jerzy; Brunton, Paul Anthony

2010-06-01

Various options are available in clinical practice for the replacement of a single missing tooth, ranging from conventional fixed and removable dental prostheses to a single implant-supported crown. There are situations in which a semipermanent fixed dental prosthesis may be desirable, particularly for patients who have completed orthodontic treatment but are too young to embark on implant therapy. Following advances in fiber-reinforcement technology, fiber-reinforced composite resin (FRC) now represents a lower-cost alternative to traditional metal-ceramic for the construction of resin-bonded prostheses. Two case reports illustrate the use of FRC prostheses as fixed semipermanent_restorations.

Fixed drug eruption associated with intravenous contrast media: report in a woman receiving iohexol.

PubMed

Wright, Natalie A; Cohen, Philip R

2011-07-01

Fixed drug eruption, a medication-associated mucocutaneous reaction, rarely presents as a delayed adverse reaction to intravenous non-ionic contrast media. We describe a 57-year-old woman with a history of metastatic renal cell carcinoma who repeatedly developed a sharply demarcated, erythematous patch on her left breast after receiving the iodinated non-ionic contrast media iohexol for staging computed tomography scans. Recurrent fixed drug eruption may be avoided by using another contrast medium. Prophylactic treatment with systemic corticosteroids may prevent repeated fixed drug eruption if an alternative contrast agent cannot be used.

Alternative display and interaction devices

NASA Technical Reports Server (NTRS)

Bolas, M. T.; McDowall, I. E.; Mead, R. X.; Lorimer, E. R.; Hackbush, J. E.; Greuel, C.

1995-01-01

While virtual environment systems are typically thought to consist of a head mounted display and a flex-sensing glove, alternative peripheral devices are beginning to be developed in response to application requirements. Three such alternatives are discussed: fingertip sensing gloves, fixed stereoscopic viewers, and counterbalanced head mounted displays. A subset of commercial examples that highlight each alternative is presented as well as a brief discussion of interesting engineering and implementation issues.

A fixed energy fixed angle inverse scattering in interior transmission problem

NASA Astrophysics Data System (ADS)

Chen, Lung-Hui

2017-06-01

We study the inverse acoustic scattering problem in mathematical physics. The problem is to recover the index of refraction in an inhomogeneous medium by measuring the scattered wave fields in the far field. We transform the problem to the interior transmission problem in the study of the Helmholtz equation. We find an inverse uniqueness on the scatterer with a knowledge of a fixed interior transmission eigenvalue. By examining the solution in a series of spherical harmonics in the far field, we can determine uniquely the perturbation source for the radially symmetric perturbations.

Reduction of low frequency ac losses in coaxial cables of type II superconductors by a steady bias current

NASA Astrophysics Data System (ADS)

LeBlanc, M. A. R.; Cameron, Daniel S. M.; LeBlanc, David; Meng, Jinglei

1996-01-01

Hysteresis losses, Wac, in the core of a monolithic coaxial cable carrying an alternating current of fixed amplitude Iac are predicted to trace a valley as a steady bias current Ibias is superimposed on Iac, when (a) the critical current density jc diminishes with increasing magnetic field H, and/or (b) a Meissner current IM or a surface barrier current ISB opposing flux entry play a role. The predicted Ibias,min where the valley minimum occurs and the value of Wac at the minima are displayed for various IM≥0 and ISB≥0 when jc=α (Bean) and jc=α/H (Kim approximation).

Biotemplated flagellar nanoswimmers

NASA Astrophysics Data System (ADS)

Ali, Jamel; Cheang, U. Kei; Darvish, Armin; Kim, Hoyeon; Kim, Min Jun

2017-11-01

In this article, a porous hollow biotemplated nanoscale helix that can serve as a low Reynolds number robotic swimmer is reported. The nanorobot utilizes repolymerized bacterial flagella from Salmonella typhimurium as a nanotemplate for biomineralization. We demonstrate the ability to generate templated nanotubes with distinct helical geometries by using specific alkaline pH values to fix the polymorphic form of flagellar templates. Using uniform rotating magnetic fields to mimic the motion of the flagellar motor, we explore the swimming characteristics of these silica templated flagella and demonstrate the ability to wirelessly control their trajectories. The results suggest that the biotemplated nanoswimmer can be a cost-effective alternative to the current top-down methods used to produce helical nanorobots.

On flow of electrically conducting fluids over a flat plate in the presence of a transverse magnetic field

NASA Technical Reports Server (NTRS)

Rossow, Vernon J

1958-01-01

The use of a magnetic field to control the motion of electrically conducting fluids is studied. The incompressible boundary-layer solutions are found for flow over a flat plate when the magnetic field is fixed relative to the plate or to the fluid. The equations are integrated numerically for the effect of the transverse magnetic field on the velocity and temperature profiles, and hence, the skin friction and rate of heat transfer. It is concluded that the skin friction and the heat-transfer rate are reduced when the transverse magnetic field is fixed relative to the plate and increased when fixed relative to the fluid. The total drag is increased in all of the areas.

Investigation and Implementation of Commercially Available Optically Stimulated Luminescence Dosimeters for Use in Fixed Nuclear Accident Dosimeter Systems.

PubMed

Georgeson, David L; Christiansen, Byron H

2018-06-01

Idaho National Laboratory transitioned from an external dosimetry system reliant on thermoluminescent dosimeters to one that uses optically stimulated luminescence dosimeters in 2010. This change not only affected the dosimeters worn by personnel, but those found in the nuclear-accident dosimeters used across Idaho National Laboratory. The elimination of on-site use and processing of thermoluminescent dosimeters impacted Idaho National Laboratory's ability to process nuclear-accident dosimeters in a timely manner. This change in processes drove Idaho National Laboratory to develop an alternative method for fixed nuclear-accident dosimeter gamma-dose analyses. This new method was driven by the need to establish a simple, cost-effective, and rapid-turnaround alternative to the thermoluminescent-dosimeter-based fixed nuclear-accident dosimeter system. An adaptation of existing technologies proved to be the most efficient path to this end. The purpose of this article is to delineate the technical basis for replacing the thermoluminescent dosimeter contained within the Idaho National Laboratory fixed nuclear-accident dosimeter system with optically stimulated luminescence-based Landauer, Inc., nanoDot dosimeters.

A Simple Accurate Alternative to the Minimum-Deviation Method for the Determination of the Refractive Index of a Prism.

ERIC Educational Resources Information Center

Waldenstrom, S.; Naqvi, K. Razi

1978-01-01

Proposes an alternative to the classical minimum-deviation method for determining the refractive index of a prism. This new "fixed angle of incidence method" may find applications in research. (Author/GA)

Simulation of design-unbiased point-to-particle sampling compared to alternatives on plantation rows

Treesearch

Thomas B. Lynch; David Hamlin; Mark J. Ducey

2016-01-01

Total quantities of tree attributes can be estimated in plantations by sampling on plantation rows using several methods. At random sample points on a row, either fixed row lengths or variable row lengths with a fixed number of sample trees can be assessed. Ratio of means or mean of ratios estimators can be developed for the fixed number of trees option but are not...

Impact of Rate Design Alternatives on Residential Solar Customer Bills: Increased Fixed Charges, Minimum Bills and Demand-Based Rates

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

McLaren, Joyce; Davidson, Carolyn; Miller, John

Utilities are proposing changes to residential rate structures to address concerns about lost revenue due to increased adoption of distributed solar generation. An investigation of the impacts of increased fixed charges, minimum bills and residential demand charges on PV and non-PV customer bills suggests that minimum bills more accurately capture utilities' revenue requirement than fixed charges, while not acting as a disincentive to efficiency or negatively impacting low-income customers.

Alternative Parameterizations for Cluster Editing

NASA Astrophysics Data System (ADS)

Komusiewicz, Christian; Uhlmann, Johannes

Given an undirected graph G and a nonnegative integer k, the NP-hard Cluster Editing problem asks whether G can be transformed into a disjoint union of cliques by applying at most k edge modifications. In the field of parameterized algorithmics, Cluster Editing has almost exclusively been studied parameterized by the solution size k. Contrastingly, in many real-world instances it can be observed that the parameter k is not really small. This observation motivates our investigation of parameterizations of Cluster Editing different from the solution size k. Our results are as follows. Cluster Editing is fixed-parameter tractable with respect to the parameter "size of a minimum cluster vertex deletion set of G", a typically much smaller parameter than k. Cluster Editing remains NP-hard on graphs with maximum degree six. A restricted but practically relevant version of Cluster Editing is fixed-parameter tractable with respect to the combined parameter "number of clusters in the target graph" and "maximum number of modified edges incident to any vertex in G". Many of our results also transfer to the NP-hard Cluster Deletion problem, where only edge deletions are allowed.

Brushless direct-current motor with stationary armature and field

NASA Technical Reports Server (NTRS)

Studer, P. A.

1970-01-01

Electronically commutated dc motor has an active fixed field winding, and active fixed armature winding, and passive rotor. By use of brushless dc motor switching technique, motor provides continuous controllable and reversible torque without use of sliding contacts.

Bar coded retroreflective target

DOEpatents

Vann, Charles S.

2000-01-01

This small, inexpensive, non-contact laser sensor can detect the location of a retroreflective target in a relatively large volume and up to six degrees of position. The tracker's laser beam is formed into a plane of light which is swept across the space of interest. When the beam illuminates the retroreflector, some of the light returns to the tracker. The intensity, angle, and time of the return beam is measured to calculate the three dimensional location of the target. With three retroreflectors on the target, the locations of three points on the target are measured, enabling the calculation of all six degrees of target position. Until now, devices for three-dimensional tracking of objects in a large volume have been heavy, large, and very expensive. Because of the simplicity and unique characteristics of this tracker, it is capable of three-dimensional tracking of one to several objects in a large volume, yet it is compact, light-weight, and relatively inexpensive. Alternatively, a tracker produces a diverging laser beam which is directed towards a fixed position, and senses when a retroreflective target enters the fixed field of view. An optically bar coded target can be read by the tracker to provide information about the target. The target can be formed of a ball lens with a bar code on one end. As the target moves through the field, the ball lens causes the laser beam to scan across the bar code.

Miniature Laser Tracker

DOEpatents

Vann, Charles S.

2003-09-09

This small, inexpensive, non-contact laser sensor can detect the location of a retroreflective target in a relatively large volume and up to six degrees of position. The tracker's laser beam is formed into a plane of light which is swept across the space of interest. When the beam illuminates the retroreflector, some of the light returns to the tracker. The intensity, angle, and time of the return beam is measured to calculate the three dimensional location of the target. With three retroreflectors on the target, the locations of three points on the target are measured, enabling the calculation of all six degrees of target position. Until now, devices for three-dimensional tracking of objects in a large volume have been heavy, large, and very expensive. Because of the simplicity and unique characteristics of this tracker, it is capable of three-dimensional tracking of one to several objects in a large volume, yet it is compact, light-weight, and relatively inexpensive. Alternatively, a tracker produces a diverging laser beam which is directed towards a fixed position, and senses when a retroreflective target enters the fixed field of view. An optically bar coded target can be read by the tracker to provide information about the target. The target can be formed of a ball lens with a bar code on one end. As the target moves through the field, the ball lens causes the laser beam to scan across the bar code.

Alternative Line Coding Scheme with Fixed Dimming for Visible Light Communication

NASA Astrophysics Data System (ADS)

Niaz, M. T.; Imdad, F.; Kim, H. S.

2017-01-01

An alternative line coding scheme called fixed-dimming on/off keying (FD-OOK) is proposed for visible-light communication (VLC). FD-OOK reduces the flickering caused by a VLC transmitter and can maintain a 50% dimming level. Simple encoder and decoder are proposed which generates codes where the number of bits representing one is same as the number of bits representing zero. By keeping the number of ones and zeros equal the change in the brightness of lighting may be minimized and kept constant at 50%, thereby reducing the flickering in VLC. The performance of FD-OOK is analysed with two parameters: the spectral efficiency and power requirement.

Gaugeon formalism for the second-rank antisymmetric tensor gauge fields

NASA Astrophysics Data System (ADS)

Aochi, Masataka; Endo, Ryusuke; Miura, Hikaru

2018-02-01

We present a BRST symmetric gaugeon formalism for the second-rank antisymmetric tensor gauge fields. A set of vector gaugeon fields is introduced as a quantum gauge freedom. One of the gaugeon fields satisfies a higher-derivative field equation; this property is necessary to change the gauge-fixing parameter of the antisymmetric tensor gauge field. A naive Lagrangian for the vector gaugeon fields is itself invariant under a gauge transformation for the vector gaugeon field. The Lagrangian of our theory includes the gauge-fixing terms for the gaugeon fields and corresponding Faddeev-Popov ghost terms.

Nonparametric estimation and testing of fixed effects panel data models

PubMed Central

Henderson, Daniel J.; Carroll, Raymond J.; Li, Qi

2009-01-01

In this paper we consider the problem of estimating nonparametric panel data models with fixed effects. We introduce an iterative nonparametric kernel estimator. We also extend the estimation method to the case of a semiparametric partially linear fixed effects model. To determine whether a parametric, semiparametric or nonparametric model is appropriate, we propose test statistics to test between the three alternatives in practice. We further propose a test statistic for testing the null hypothesis of random effects against fixed effects in a nonparametric panel data regression model. Simulations are used to examine the finite sample performance of the proposed estimators and the test statistics. PMID:19444335

Changes in Blood Pressure and Heart Rate during Fixed-Interval Responding in Squirrel Monkeys

ERIC Educational Resources Information Center

DeWeese, Jo

2009-01-01

Episodic and sustained increases in heart rate and mean arterial blood pressure can occur with recurring patterns of schedule-controlled behavior. Most previous studies were conducted under fixed-ratio schedules, which maintained a consistent high rate of responding that alternated with periods of no responding during times when the schedule was…

48 CFR 752.247-70 - Preference for privately owned U.S.-flag commercial vessels.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., depending on current compliance with Cargo Preference requirements. If freight under the contract is fixed... commodity. (viii) Gross weight in pounds and cubic feet if available. (ix) Total ocean freight revenue in U.S. dollars. Alternate I (d) If freight is fixed on a U.S. flag vessel, except as provided in...

48 CFR 752.247-70 - Preference for privately owned U.S.-flag commercial vessels.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., depending on current compliance with Cargo Preference requirements. If freight under the contract is fixed... commodity. (viii) Gross weight in pounds and cubic feet if available. (ix) Total ocean freight revenue in U.S. dollars. Alternate I (d) If freight is fixed on a U.S. flag vessel, except as provided in...

48 CFR 752.247-70 - Preference for privately owned U.S.-flag commercial vessels.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., depending on current compliance with Cargo Preference requirements. If freight under the contract is fixed... commodity. (viii) Gross weight in pounds and cubic feet if available. (ix) Total ocean freight revenue in U.S. dollars. Alternate I (d) If freight is fixed on a U.S. flag vessel, except as provided in...

48 CFR 752.247-70 - Preference for privately owned U.S.-flag commercial vessels.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., depending on current compliance with Cargo Preference requirements. If freight under the contract is fixed... commodity. (viii) Gross weight in pounds and cubic feet if available. (ix) Total ocean freight revenue in U.S. dollars. Alternate I (d) If freight is fixed on a U.S. flag vessel, except as provided in...

A Geometric Analysis of when Fixed Weighting Schemes Will Outperform Ordinary Least Squares

ERIC Educational Resources Information Center

Davis-Stober, Clintin P.

2011-01-01

Many researchers have demonstrated that fixed, exogenously chosen weights can be useful alternatives to Ordinary Least Squares (OLS) estimation within the linear model (e.g., Dawes, Am. Psychol. 34:571-582, 1979; Einhorn & Hogarth, Org. Behav. Human Perform. 13:171-192, 1975; Wainer, Psychol. Bull. 83:213-217, 1976). Generalizing the approach of…

Flow, turbulence, and drag associated with engineered log jams in a fixed-bed experimental channel

USDA-ARS?s Scientific Manuscript database

Engineered log jams (ELJs) have become attractive alternatives for river restoration and bank stabilization programs. Yet the effects of ELJs on turbulent flow and the fluid forces acting on the ELJs are not well known, and such information could inform design criteria. In this study, a fixed-bed ph...

Comparison of Effectiveness of Computerized and Conventional Fixed and Learning Module in Undergraduate Pathology Teaching

ERIC Educational Resources Information Center

Madhavan, Manoharan; Kaur, Gurjeet

2006-01-01

Introduction: Fixed Learning Module (FLM) adopted in pathology teaching to medical undergraduates, encompasses exhibition of potted specimens and charts. Though it is an important teaching method it also has its limitations. Aim: To create an alternative method for teaching pathology using web based, interactive computer technology [i.e.,…

48 CFR 970.5215-3 - Conditional payment of fee, profit, and other incentives-facility management contracts

Code of Federal Regulations, 2012 CFR

2012-10-01

... period, the DOE Operations/Field Office Manager, or designee, may reduce any otherwise earned fee, fixed... Operations/Field Office Manager, or designee, may reduce in whole or in part any otherwise earned fee, fixed...

Electric field characteristics of electroconvulsive therapy with individualized current amplitude: a preclinical study.

PubMed

Lee, Won Hee; Lisanby, Sarah H; Laine, Andrew F; Peterchev, Angel V

2013-01-01

This study examines the characteristics of the electric field induced in the brain by electroconvulsive therapy (ECT) with individualized current amplitude. The electric field induced by bilateral (BL), bifrontal (BF), right unilateral (RUL), and frontomedial (FM) ECT electrode configurations was computed in anatomically realistic finite element models of four nonhuman primates (NHPs). We generated maps of the electric field strength relative to an empirical neural activation threshold, and determined the stimulation strength and focality at fixed current amplitude and at individualized current amplitudes corresponding to seizure threshold (ST) measured in the anesthetized NHPs. The results show less variation in brain volume stimulated above threshold with individualized current amplitudes (16-36%) compared to fixed current amplitude (30-62%). Further, the stimulated brain volume at amplitude-titrated ST is substantially lower than that for ECT with conventional fixed current amplitudes. Thus individualizing the ECT stimulus current could compensate for individual anatomical variability and result in more focal and uniform electric field exposure across different subjects compared to the standard clinical practice of using high, fixed current for all patients.

Neural networks with local receptive fields and superlinear VC dimension.

PubMed

Schmitt, Michael

2002-04-01

Local receptive field neurons comprise such well-known and widely used unit types as radial basis function (RBF) neurons and neurons with center-surround receptive field. We study the Vapnik-Chervonenkis (VC) dimension of feedforward neural networks with one hidden layer of these units. For several variants of local receptive field neurons, we show that the VC dimension of these networks is superlinear. In particular, we establish the bound Omega(W log k) for any reasonably sized network with W parameters and k hidden nodes. This bound is shown to hold for discrete center-surround receptive field neurons, which are physiologically relevant models of cells in the mammalian visual system, for neurons computing a difference of gaussians, which are popular in computational vision, and for standard RBF neurons, a major alternative to sigmoidal neurons in artificial neural networks. The result for RBF neural networks is of particular interest since it answers a question that has been open for several years. The results also give rise to lower bounds for networks with fixed input dimension. Regarding constants, all bounds are larger than those known thus far for similar architectures with sigmoidal neurons. The superlinear lower bounds contrast with linear upper bounds for single local receptive field neurons also derived here.

Magnetic hyperthermia study in water based magnetic fluids containing TMAOH coated Fe3O4 using infrared thermography

NASA Astrophysics Data System (ADS)

Lahiri, B. B.; Ranoo, Surojit; Philip, John

2017-01-01

We study the alternating magnetic field induced heating of a water based ferrofluid containing tetramethyl ammonium hydroxide coated iron oxide nanoparticles using infrared thermography and compare the results obtained from the conventional fiber optic temperature sensor. Experiments are performed on ferrofluid samples of five different concentrations and under four different external field amplitudes at a fixed frequency. The temperature rise curves measured using both the infrared thermography and fiber optic sensor are found to be very similar up to a certain time interval, above which deviations are observed, which are attributed to the internal and external convection phenomena. A correction methodology is developed to account for the convection losses. The convection corrected specific absorption rate is found to be in good agreement with the values obtained from the conventional fiber optic temperature sensor, within a maximum error of ±3.4%. The highest specific absorption rate obtained in the present study is 135.98 (±4.6) W/gFe for a sample concentration of 3 wt.%, at an external field amplitude and a frequency of 63.0 kA m-1 and 126 kHz, respectively. The specific absorption rate is found to decrease with increasing sample concentration, due to the enhancement of dipolar interaction with increasing sample concentration due to agglomeration. This study validates the efficacy and universal applicability of IRT as an alternate, real time, non-contact and wide area temperature measurement methodology for magnetic fluid hyperthermia experiments without any sample contamination.

Electromagnetic scattering and emission by a fixed multi-particle object in local thermal equilibrium: General formalism.

PubMed

Mishchenko, Michael I

2017-10-01

The majority of previous studies of the interaction of individual particles and multi-particle groups with electromagnetic field have focused on either elastic scattering in the presence of an external field or self-emission of electromagnetic radiation. In this paper we apply semi-classical fluctuational electrodynamics to address the ubiquitous scenario wherein a fixed particle or a fixed multi-particle group is exposed to an external quasi-polychromatic electromagnetic field as well as thermally emits its own electromagnetic radiation. We summarize the main relevant axioms of fluctuational electrodynamics, formulate in maximally rigorous mathematical terms the general scattering-emission problem for a fixed object, and derive such fundamental corollaries as the scattering-emission volume integral equation, the Lippmann-Schwinger equation for the dyadic transition operator, the multi-particle scattering-emission equations, and the far-field limit. We show that in the framework of fluctuational electrodynamics, the computation of the self-emitted component of the total field is completely separated from that of the elastically scattered field. The same is true of the computation of the emitted and elastically scattered components of quadratic/bilinear forms in the total electromagnetic field. These results pave the way to the practical computation of relevant optical observables.

Character Sets for PLATO/NovaNET: An Expository Catalog.

ERIC Educational Resources Information Center

Gilpin, John B.

The PLATO and NovaNET computer-based instructional systems use a fixed system character set ("normal font") and an author-definable character set ("alternate font"). The alternate font lets the author construct his own symbols and bitmapped pictures. This expository catalog allows users to determine quickly (1) whether there is…

75 FR 52733 - Record of Decision (ROD) for Fort Bliss Army Growth and Force Structure Realignment

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-27

... alternative consists of actions in three different categories (stationing/training, land use changes, and... (Stationing Action Alternative 4); land use changes that allow fixed site bivouac areas, mission support... supports Army expansion, future stationing actions, and land use changes and training infrastructure...

Fixing the model for transcription: the DNA moves, not the polymerase.

PubMed

Papantonis, Argyris; Cook, Peter R

2011-01-01

The traditional model for transcription sees active polymerases tracking along their templates. An alternative (controversial) model has active enzymes immobilized in "factories." Recent evidence supports the idea that the DNA moves, not the polymerase, and points to alternative explanations of how regulatory motifs like enhancers and silencers work.

Localization and Classification of Paddy Field Pests using a Saliency Map and Deep Convolutional Neural Network.

PubMed

Liu, Ziyi; Gao, Junfeng; Yang, Guoguo; Zhang, Huan; He, Yong

2016-02-11

We present a pipeline for the visual localization and classification of agricultural pest insects by computing a saliency map and applying deep convolutional neural network (DCNN) learning. First, we used a global contrast region-based approach to compute a saliency map for localizing pest insect objects. Bounding squares containing targets were then extracted, resized to a fixed size, and used to construct a large standard database called Pest ID. This database was then utilized for self-learning of local image features which were, in turn, used for classification by DCNN. DCNN learning optimized the critical parameters, including size, number and convolutional stride of local receptive fields, dropout ratio and the final loss function. To demonstrate the practical utility of using DCNN, we explored different architectures by shrinking depth and width, and found effective sizes that can act as alternatives for practical applications. On the test set of paddy field images, our architectures achieved a mean Accuracy Precision (mAP) of 0.951, a significant improvement over previous methods.

Field testing of linear individual pitch control on the two-bladed controls advanced research turbine

DOE PAGES

van Solingen, Edwin; Fleming, Paul A.; Scholbrock, Andrew; ...

2015-04-17

This paper presents the results of field tests using linear individual pitch control (LIPC) on the two-bladed Controls Advanced Research Turbine 2 (CART2) at the National Renewable Energy Laboratory (NREL). LIPC has recently been introduced as an alternative to the conventional individual pitch control (IPC) strategy for two-bladed wind turbines. The main advantage of LIPC over conventional IPC is that it requires, at most, only two feedback loops to potentially reduce the periodic blade loads. In previous work, LIPC was designed to implement blade pitch angles at a fixed frequency (e.g., the once-per-revolution (1P) frequency), which made it only applicablemore » in above-rated wind turbine operating conditions. In this study, LIPC is extended to below-rated operating conditions by gain scheduling the controller on the rotor speed. With this extension, LIPC and conventional IPC are successfully applied to the NREL CART2 wind turbine. Lastly, the field-test results obtained during the measurement campaign indicate that LIPC significantly reduces the wind turbine loads for both below-rated and above-rated operation.« less

Localization and Classification of Paddy Field Pests using a Saliency Map and Deep Convolutional Neural Network

PubMed Central

Liu, Ziyi; Gao, Junfeng; Yang, Guoguo; Zhang, Huan; He, Yong

2016-01-01

We present a pipeline for the visual localization and classification of agricultural pest insects by computing a saliency map and applying deep convolutional neural network (DCNN) learning. First, we used a global contrast region-based approach to compute a saliency map for localizing pest insect objects. Bounding squares containing targets were then extracted, resized to a fixed size, and used to construct a large standard database called Pest ID. This database was then utilized for self-learning of local image features which were, in turn, used for classification by DCNN. DCNN learning optimized the critical parameters, including size, number and convolutional stride of local receptive fields, dropout ratio and the final loss function. To demonstrate the practical utility of using DCNN, we explored different architectures by shrinking depth and width, and found effective sizes that can act as alternatives for practical applications. On the test set of paddy field images, our architectures achieved a mean Accuracy Precision (mAP) of 0.951, a significant improvement over previous methods. PMID:26864172

A new type of accelerator for charged particle cancer therapy

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

Edgecock, Rob

2013-04-19

Non-scaling Fixed Field Alternating Gradient accelerators (ns-FFAGs) show great potential for the acceleration of protons and light ions for the treatment of certain cancers. They have unique features as they combine techniques from the existing types of accelerators, cyclotrons and synchrotrons, and hence look to have advantages over both for this application. However, these unique features meant that it was necessary to build one of these accelerators to show that it works and to undertake a detailed conceptual design of a medical machine. Both of these have now been done. This paper will describe the concepts of this type ofmore » accelerator, show results from the proof-of-principle machine (EMMA) and described the medical machine (PAMELA).« less

HEATHER - HElium Ion Accelerator for RadioTHERapy

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

Taylor, Jordan; Edgecock, Thomas; Green, Stuart

2017-05-01

A non-scaling fixed field alternating gradient (nsFFAG) accelerator is being designed for helium ion therapy. This facility will consist of 2 superconducting rings, treating with helium ions (He²⁺ ) and image with hydrogen ions (H + 2 ). Currently only carbon ions are used to treat cancer, yet there is an increasing interest in the use of lighter ions for therapy. Lighter ions have reduced dose tail beyond the tumour compared to carbon, caused by low Z secondary particles produced via inelastic nuclear reactions. An FFAG approach for helium therapy has never been previously considered. Having demonstrated isochronous acceleration frommore » 0.5 MeV to 900 MeV, we now demonstrate the survival of a realistic beam across both stages.« less

16,000-rpm Interior Permanent Magnet Reluctance Machine with Brushless Field Excitation

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

Hsu, J.S.; Burress, T.A.; Lee, S.T.

2007-10-31

The reluctance interior permanent magnet (RIPM) motor is currently used by many leading auto manufacturers for hybrid vehicles. The power density for this type of motor is high compared with that of induction motors and switched reluctance motors. The primary drawback of the RIPM motor is the permanent magnet (PM) because during high-speed operation, the fixed PM produces a huge back electromotive force (emf) that must be reduced before the current will pass through the stator windings. This reduction in back-emf is accomplished with a significant direct-axis (d-axis) demagnetization current, which opposes the PM's flux to reduce the flux seenmore » by the stator wires. This may lower the power factor and efficiency of the motor and raise the requirement on the alternate current (ac) power supply; consequently, bigger inverter switching components, thicker motor winding conductors, and heavier cables are required. The direct current (dc) link capacitor is also affected when it must accommodate heavier harmonic currents. It is commonly agreed that, for synchronous machines, the power factor can be optimized by varying the field excitation to minimize the current. The field produced by the PM is fixed and cannot be adjusted. What can be adjusted is reactive current to the d-axis of the stator winding, which consumes reactive power but does not always help to improve the power factor. The objective of this project is to avoid the primary drawbacks of the RIPM motor by introducing brushless field excitation (BFE). This offers both high torque per ampere (A) per core length at low speed by using flux, which is enhanced by increasing current to a fixed excitation coil, and flux, which is weakened at high speed by reducing current to the excitation coil. If field weakening is used, the dc/dc boost converter used in a conventional RIPM motor may be eliminated to reduce system costs. However, BFE supports a drive system with a dc/dc boost converter, because it can further extend the constant power speed range of the drive system and adjust the field for power factor and efficiency gains. Lower core losses at low torque regions, especially at high speeds, are attained by reducing the field excitation. Safety and reliability are increased by weakening the field when a winding short-circuit fault occurs, preventing damage to the motor. For a high-speed motor operating at 16,000-revolutions per minute (rpm), mechanical stress is a challenge. Bridges that link the rotor punching segments together must be thickened for mechanical integrity; consequently, increased rotor flux leakage significantly lowers motor performance. This barrier can be overcome by BFE to ensure sufficient rotor flux when needed.« less

Affimer proteins for F-actin: novel affinity reagents that label F-actin in live and fixed cells.

PubMed

Lopata, Anna; Hughes, Ruth; Tiede, Christian; Heissler, Sarah M; Sellers, James R; Knight, Peter J; Tomlinson, Darren; Peckham, Michelle

2018-04-26

Imaging the actin cytoskeleton in cells uses a wide range of approaches. Typically, a fluorescent derivative of the small cyclic peptide phalloidin is used to image F-actin in fixed cells. Lifeact and F-tractin are popular for imaging the cytoskeleton in live cells. Here we characterised novel affinity reagents called Affimers that specifically bind to F-actin in vitro to determine if they are suitable alternatives as eGFP-fusion proteins, to label actin in live cells, or for labeling F-actin in fixed cells. In vitro experiments showed that 3 out of the 4 Affimers (Affimers 6, 14 and 24) tested bind tightly to purified F-actin, and appear to have overlapping binding sites. As eGFP-fusion proteins, the same 3 Affimers label F-actin in live cells. FRAP experiments suggest that eGFP-Affimer 6 behaves most similarly to F-tractin and Lifeact. However, it does not colocalise with mCherry-actin in dynamic ruffles, and may preferentially bind stable actin filaments. All 4 Affimers label F-actin in methanol fixed cells, while only Affimer 14 labels F-actin after paraformaldehyde fixation. eGFP-Affimer 6 has potential for use in selectively imaging the stable actin cytoskeleton in live cells, while all 4 Affimers are strong alternatives to phalloidin for labelling F-actin in fixed cells.

The L0 Regularized Mumford-Shah Model for Bias Correction and Segmentation of Medical Images.

PubMed

Duan, Yuping; Chang, Huibin; Huang, Weimin; Zhou, Jiayin; Lu, Zhongkang; Wu, Chunlin

2015-11-01

We propose a new variant of the Mumford-Shah model for simultaneous bias correction and segmentation of images with intensity inhomogeneity. First, based on the model of images with intensity inhomogeneity, we introduce an L0 gradient regularizer to model the true intensity and a smooth regularizer to model the bias field. In addition, we derive a new data fidelity using the local intensity properties to allow the bias field to be influenced by its neighborhood. Second, we use a two-stage segmentation method, where the fast alternating direction method is implemented in the first stage for the recovery of true intensity and bias field and a simple thresholding is used in the second stage for segmentation. Different from most of the existing methods for simultaneous bias correction and segmentation, we estimate the bias field and true intensity without fixing either the number of the regions or their values in advance. Our method has been validated on medical images of various modalities with intensity inhomogeneity. Compared with the state-of-art approaches and the well-known brain software tools, our model is fast, accurate, and robust with initializations.

Coping with changing conditions: alternative strategies for the delivery of maternal and child health and family planning services in Dhaka, Bangladesh.

PubMed Central

Routh, S.; el Arifeen, S.; Jahan, S. A.; Begum, A.; Thwin, A. A.; Baqui, A. H.

2001-01-01

The door-to-door distribution of contraceptives and information on maternal and child health and family planning (MCH-FP) services, through bimonthly visits to eligible couples by trained fieldworkers, has been instrumental in increasing the contraceptive prevalence rate and immunization coverage in Bangladesh. The doorstep delivery strategy, however, is labour-intensive and costly. More cost-effective service delivery strategies are needed, not only for family planning services but also for a broader package of reproductive and other essential health services. Against this backdrop, operations research was conducted by the Centre for Health and Population Research at the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B) from January 1996 to May 1997, in collaboration with government agencies and a leading national nongovernmental organization, with a view to developing and field-testing alternative approaches to the delivery of MCH-FP services in urban areas. Two alternative strategies featuring the withdrawal of home-based distribution and the delivery of basic health care from fixed-site facilities were tested in two areas of Dhaka. The clinic-based service delivery strategy was found to be a feasible alternative to the resource-intensive doorstep system in urban Dhaka. It did not adversely affect programme performance and it allowed the needs of clients to be addressed holistically through a package of essential health and family planning services. PMID:11242821

Analytical Deriving of the Field Capacity through Soil Bundle Model

NASA Astrophysics Data System (ADS)

Arnone, E.; Viola, F.; Antinoro, C.; Noto, L. V.

2015-12-01

The concept of field capacity as soil hydraulic parameter is widely used in many hydrological applications. Althought its recurring usage, its definition is not univocal. Traditionally, field capacity has been related to the amount of water that remains in the soil after the excess water has drained away and the water downward movement experiences a significant decresase. Quantifying the drainage of excess of water may be vague and several definitions, often subjective, have been proposed. These definitions are based on fixed thresholds either of time, pressure, or flux to which the field capacity condition is associated. The flux-based definition identifies the field capacity as the soil moisture value corresponding to an arbitrary fixed threshold of free drainage flux. Recently, many works have investigated the flux-based definition by varying either the drainage threshold, the geometry setting and mainly the description of the drainage flux. Most of these methods are based on the simulation of the flux through a porous medium by using the Darcy's law or Richard's equation. Using the above-mentioned flux-based definition, in this work we propose an alternative analytical approach for deriving the field capacity based on a bundle-of-tubes model. The pore space of a porous medium is conceptualized as a bundle of capillary tubes of given length of different radii, derived from a known distribution. The drainage from a single capillary tube is given by the analytical solution of the differential equation describing the water height evolution within the capillary tube. This equation is based on the Poiseuille's law and describes the drainage flux with time as a function of tube radius. The drainage process is then integrated for any portion of soil taking into account the tube radius distribution which in turns depends on the soil type. This methodology allows to analytically derive the dynamics of drainage water flux for any soil type and consequently to define the soil field capacity as the latter reachs a given threshold value. The theoretical model also accounts for the tortuosity which characterizes the water pathways in real soils, but neglects the voids mutual interconnections.

More asymptotic safety guaranteed

NASA Astrophysics Data System (ADS)

Bond, Andrew D.; Litim, Daniel F.

2018-04-01

We study interacting fixed points and phase diagrams of simple and semisimple quantum field theories in four dimensions involving non-Abelian gauge fields, fermions and scalars in the Veneziano limit. Particular emphasis is put on new phenomena which arise due to the semisimple nature of the theory. Using matter field multiplicities as free parameters, we find a large variety of interacting conformal fixed points with stable vacua and crossovers inbetween. Highlights include semisimple gauge theories with exact asymptotic safety, theories with one or several interacting fixed points in the IR, theories where one of the gauge sectors is both UV free and IR free, and theories with weakly interacting fixed points in the UV and the IR limits. The phase diagrams for various simple and semisimple settings are also given. Further aspects such as perturbativity beyond the Veneziano limit, conformal windows, and implications for model building are discussed.

Androgen responses to reproductive competition of males pursuing either fixed or plastic alternative reproductive tactics.

PubMed

von Kuerthy, Corinna; Ros, Albert F H; Taborsky, Michael

2016-11-15

Alternative reproductive tactics (ARTs), which can be plastic or fixed for life, may be characterized by distinct hormonal profiles. The relative plasticity hypothesis predicts flexible androgen regulation for adult males pursuing plastic tactics, but a less flexible regulation for males using a fixed tactic throughout life. Furthermore, androgen profiles may respond to changes in the social environment, as predicted by the social reciprocity models of hormone/behaviour interactions. The cichlid fish Lamprologus callipterus provides a rare opportunity to study the roles of androgens for male ARTs within a single species, because fixed and plastic ARTs coexist. We experimentally exposed males to competitors pursuing either the same or different tactics to test predictions of the relative plasticity and the social reciprocity models. Androgen profiles of different male types partly comply with predictions derived from the relative plasticity hypothesis: males of the plastic bourgeois/sneaker male trajectory showed different 11-ketotestosterone (11-KT) levels when pursuing either bourgeois or parasitic sneaker male behaviours. Surprisingly, males pursuing the fixed dwarf male tactic showed the highest free and conjugated 11-KT and testosterone (T) levels. Our experimental social challenges significantly affected the free 11-KT levels of bourgeois males, but the androgen responses did not differ between challenges involving different types of competitors. Furthermore, the free T-responses of the bourgeois males correlated with their aggressive behaviour exhibited against competitors. Our results provide new insights into the endocrine responsiveness of fixed and plastic ARTs, confirming and refuting some predictions of both the relative plasticity and the social reciprocity models. © 2016. Published by The Company of Biologists Ltd.

Renormalization group fixed points of foliated gravity-matter systems

NASA Astrophysics Data System (ADS)

Biemans, Jorn; Platania, Alessia; Saueressig, Frank

2017-05-01

We employ the Arnowitt-Deser-Misner formalism to study the renormalization group flow of gravity minimally coupled to an arbitrary number of scalar, vector, and Dirac fields. The decomposition of the gravitational degrees of freedom into a lapse function, shift vector, and spatial metric equips spacetime with a preferred (Euclidean) "time"- direction. In this work, we provide a detailed derivation of the renormalization group flow of Newton's constant and the cosmological constant on a flat Friedmann-Robertson-Walker background. Adding matter fields, it is shown that their contribution to the flow is the same as in the covariant formulation and can be captured by two parameters d g d λ . We classify the resulting fixed point structure as a function of these parameters finding that the existence of non-Gaussian renormalization group fixed points is rather generic. In particular the matter content of the standard model and its most common extensions gives rise to one non-Gaussian fixed point with real critical exponents suitable for Asymptotic Safety. Moreover, we find non-Gaussian fixed points for any number of scalar matter fields, making the scenario attractive for cosmological model building.

Alternative Work Schedules in Office and Nonoffice Work Settings.

ERIC Educational Resources Information Center

Kirk, Raymond J.; Barton, H. David

A rapidly growing change in the workplace is the replacement of a fixed work schedule with a variety of alternative work schedules (AWS), including both flexible and compressed schedules. Experimenting organizations (N=901) evaluated one of four major categories of AWS in office and nonoffice settings, i.e., a flexible 8-hour day;…

Alternative prosthodontic-based treatment of a patient with hypocalcified type Amelogenesis Imperfecta.

PubMed

Jivanescu, Anca; Miglionico, Antonio; Barua, Souman; Hategan, Simona Ioana

2017-07-01

The Amelogenesis Imperfecta is associated with malocclusion and usually requires an interdisciplinary treatment. Due to the patient's refusal of orthodontic treatment, prosthodontics-based treatments alternative was considered and planned. The patient was treated with zirconia-based fixed partial dentures, which resulted in improved occlusion, better oral health, and improved esthetic appearance.

Analogies between the Torque-Free Motion of a Rigid Body about a Fixed Point and Light Propagation in Anisotropic Media

ERIC Educational Resources Information Center

Bellver-Cebreros, Consuelo; Rodriguez-Danta, Marcelo

2009-01-01

An apparently unnoticed analogy between the torque-free motion of a rotating rigid body about a fixed point and the propagation of light in anisotropic media is stated. First, a new plane construction for visualizing this torque-free motion is proposed. This method uses an intrinsic representation alternative to angular momentum and independent of…

The four fixed points of scale invariant single field cosmological models

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

Xue, BingKan, E-mail: bxue@princeton.edu

2012-10-01

We introduce a new set of flow parameters to describe the time dependence of the equation of state and the speed of sound in single field cosmological models. A scale invariant power spectrum is produced if these flow parameters satisfy specific dynamical equations. We analyze the flow of these parameters and find four types of fixed points that encompass all known single field models. Moreover, near each fixed point we uncover new models where the scale invariance of the power spectrum relies on having simultaneously time varying speed of sound and equation of state. We describe several distinctive new modelsmore » and discuss constraints from strong coupling and superluminality.« less

A two-beam acoustic system for tissue analysis.

PubMed

Sachs, T D; Janney, C D

1977-03-01

In the 'thermo-acoustic sensing technique' (TAST), a burst of sound, called the 'thermometer' beam is passed through tissue and its transit time is measured. A focused sound field, called the heating field, then warms a small volume in the path of the therometer beam, in proportion to the absorption. Finally, the therometer beam burst is repeated and its transit time subtracted from that of the initial thermometer burst. This difference measures the velocity perturbation in the tissue produced by the heating field. The transit time difference is td = K integral of infinity-infinity IP dchi where K is the instrument constant, I the heating field intensity, and P a perturbation factor which characterizes the tissues. The integration is carried out along the path of the thermometer beam. The perturbation factor is P = (formula: see text) where C is the specific heat, rho the denisty, V the velocity of sound, (formula: see text) the temperature coefficient of velocity and alpha the heating field absorption coefficient which is apparently sensitive to tissue structure and condition. Experiments on a fixed human brain showed an ability to distinguish between various tissue types combined with a spatial resolution of better than 3 mm. Should predictions based on the data and theory prove correct, TAST may become a non-invasive alternative to biopsy.

Cognition, Information Fields and Hologenomic Entanglement: Evolution in Light and Shadow

PubMed Central

Miller, William B.

2016-01-01

As the prime unification of Darwinism and genetics, the Modern Synthesis continues to epitomize mainstay evolutionary theory. Many decades after its formulation, its anchor assumptions remain fixed: conflict between macro organic organisms and selection at that level represent the near totality of any evolutionary narrative. However, intervening research has revealed a less easily appraised cellular and microbial focus for eukaryotic existence. It is now established that all multicellular eukaryotic organisms are holobionts representing complex collaborations between the co-aligned microbiome of each eukaryote and its innate cells into extensive mixed cellular ecologies. Each of these ecological constituents has demonstrated faculties consistent with basal cognition. Consequently, an alternative hologenomic entanglement model is proposed with cognition at its center and conceptualized as Pervasive Information Fields within a quantum framework. Evolutionary development can then be reconsidered as being continuously based upon communication between self-referential constituencies reiterated at every scope and scale. Immunological reactions support and reinforce self-recognition juxtaposed against external environmental stresses. PMID:27213462

Vorticity and helicity decompositions and dynamics with real Schur form of the velocity gradient

NASA Astrophysics Data System (ADS)

Zhu, Jian-Zhou

2018-03-01

The real Schur form (RSF) of a generic velocity gradient field ∇u is exploited to expose the structures of flows, in particular, our field decomposition resulting in two vorticities with only mutual linkage as the topological content of the global helicity (accordingly decomposed into two equal parts). The local transformation to the RSF may indicate alternative (co)rotating frame(s) for specifying the objective argument(s) of the constitutive equation. When ∇u is uniformly of RSF in a fixed Cartesian coordinate frame, i.e., ux = ux(x, y) and uy = uy(x, y), but uz = uz(x, y, z), the model, with the decomposed vorticities both frozen-in to u, is for two-component-two-dimensional-coupled-with-one-component-three-dimensional flows in between two-dimensional-three-component (2D3C) and fully three-dimensional-three-component ones and may help curing the pathology in the helical 2D3C absolute equilibrium, making the latter effectively work in more realistic situations.

[Health economics and antibiotic therapy].

PubMed

Leclercq, P; Bigdéli, M

1995-01-01

In the field of antibiotic therapy, particularly the methods of economic evaluation hold one's attention within the wide range of health economics' applications. Several tools allow a comparison of the outcomes of alternative strategies and thereby guide choices to the most appropriate solutions. After a brief recall of the methods classically used to evaluate health care strategy, the authors stress the importance and difficulty of fixing and applying a correct and satisfactory procedure for evaluation. An evaluation example of antibiotic therapy allows to illustrate the application of the principles confronting a field in which competition is intense and economic stakes stay large--a fact which naturally yields to seek after objective decision making criteria. The health care policies drawn by public authorities as well as the marketing strategies of the health sector trade are partly based on such evaluations. If these techniques are not intended for the practitioner in the first place, they should not be indifferent to him since they influence health authorities and thereby indirectly affect the therapeutic freedom of the physician.

Accounting for nitrogen fixation in simple models of lake nitrogen loading/export.

PubMed

Ruan, Xiaodan; Schellenger, Frank; Hellweger, Ferdi L

2014-05-20

Coastal eutrophication, an important global environmental problem, is primarily caused by excess nitrogen and management efforts consequently focus on lowering watershed N export (e.g., by reducing fertilizer use). Simple quantitative models are needed to evaluate alternative scenarios at the watershed scale. Existing models generally assume that, for a specific lake/reservoir, a constant fraction of N loading is exported downstream. However, N fixation by cyanobacteria may increase when the N loading is reduced, which may change the (effective) fraction of N exported. Here we present a model that incorporates this process. The model (Fixation and Export of Nitrogen from Lakes, FENL) is based on a steady-state mass balance with loading, output, loss/retention, and N fixation, where the amount fixed is a function of the N/P ratio of the loading (i.e., when N/P is less than a threshold value, N is fixed). Three approaches are used to parametrize and evaluate the model, including microcosm lab experiments, lake field observations/budgets and lake ecosystem model applications. Our results suggest that N export will not be reduced proportionally with N loading, which needs to be considered when evaluating management scenarios.

Maternal Nutrition and Four-Alternative Choice

ERIC Educational Resources Information Center

Davison, Michael; Krageloh, Christian U.; Fraser, Mhoyra; Breier, Bernhard H.

2007-01-01

Two groups of 10 male rats were trained to nose poke for food pellets at four alternatives that provided differing rates of pellet delivery on aperiodic schedules. After a fixed number of pellets had been delivered, 5, 10 or 20 in different conditions of the experiment, a 10-s blackout occurred, and the locations of the differing rates of pellet…

Investigating the Performance of Alternate Regression Weights by Studying All Possible Criteria in Regression Models with a Fixed Set of Predictors

ERIC Educational Resources Information Center

Waller, Niels; Jones, Jeff

2011-01-01

We describe methods for assessing all possible criteria (i.e., dependent variables) and subsets of criteria for regression models with a fixed set of predictors, x (where x is an n x 1 vector of independent variables). Our methods build upon the geometry of regression coefficients (hereafter called regression weights) in n-dimensional space. For a…

Use of rpoB gene analysis for identification of nitrogen-fixing Paenibacillus species as an alternative to the 16S rRNA gene.

PubMed

da Mota, F F; Gomes, E A; Paiva, E; Rosado, A S; Seldin, L

2004-01-01

To avoid the limitations of 16S rRNA-based phylogenetic analysis for Paenibacillus species, the usefulness of the RNA polymerase beta-subunit encoding gene (rpoB) was investigated as an alternative to the 16S rRNA gene for taxonomic studies. Partial rpoB sequences were generated for the type strains of eight nitrogen-fixing Paenibacillus species. The presence of only one copy of rpoB in the genome of P. graminis strain RSA19(T) was demonstrated by denaturing gradient gel electrophoresis and hybridization assays. A comparative analysis of the sequences of the 16S rRNA and rpoB genes was performed and the eight species showed between 91.6-99.1% (16S rRNA) and 77.9-97.3% (rpoB) similarity, allowing a more accurate discrimination between the different species using the rpoB gene. Finally, 24 isolates from the rhizosphere of different cultivars of maize previously identified as Paenibacillus spp. were assigned correctly to one of the nitrogen-fixing species. The data obtained in this study indicate that rpoB is a powerful identification tool, which can be used for the correct discrimination of the nitrogen-fixing species of agricultural and industrial importance within the genus Paenibacillus.

Democratic superstring field theory: gauge fixing

NASA Astrophysics Data System (ADS)

Kroyter, Michael

2011-03-01

We show that a partial gauge fixing of the NS sector of the democratic-picture superstring field theory leads to the non-polynomial theory. Moreover, by partially gauge fixing the Ramond sector we obtain a non-polynomial fully RNS theory at pictures 0 and 1/2 . Within the democratic theory and in the partially gauge fixed theory the equations of motion of both sectors are derived from an action. We also discuss a representation of the non-polynomial theory analogous to a manifestly two-dimensional representation of WZW theory and the action of bosonic pure-gauge solutions. We further demonstrate that one can consistently gauge fix the NS sector of the democratic theory at picture number -1. The resulting theory is new. It is a {mathbb{Z}_2} dual of the modified cubic theory. We construct analytical solutions of this theory and show that they possess the desired properties.

Note: A sample holder design for sensitive magnetic measurements at high temperatures in a magnetic properties measurement system

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

Arauzo, A.; Guerrero, E.; Urtizberea, A.

2012-06-15

A sample holder design for high temperature measurements in a commercial MPMS SQUID magnetometer from Quantum Design is presented. It fulfills the requirements for the simultaneous use of the oven and reciprocating sample option (RSO) options, thus allowing sensitive magnetic measurements up to 800 K. Alternating current susceptibility can also be measured, since the holder does not induce any phase shift relative to the ac driven field. It is easily fabricated by twisting Constantan Copyright-Sign wires into a braid nesting the sample inside. This design ensures that the sample be placed tightly into a tough holder with its orientation fixed,more » and prevents any sample displacement during the fast movements of the RSO transport, up to high temperatures.« less

Low cost satellite land mobile service for nationwide applications

NASA Technical Reports Server (NTRS)

Weiss, J. A.

1978-01-01

A satellite land mobile system using mobile radios in the UHF band, and Ku-band Communications Routing Terminals (earth stations) for a nationwide connection from any mobile location to any fixed or mobile location, and from any fixed location to any mobile location is proposed. The proposed nationwide satellite land mobile service provides: telephone network quality (1 out of 100 blockage) service, complete privacy for all the users, operation similar to the telephone network, alternatives for data services up to 32 Kbps data rates, and a cost effective and practical mobile radio compatible with system sizes ranging from 10,000 to 1,000,000 users. Seven satellite alternatives (ranging from 30 ft diameter dual beam antenna to 210 ft diameter 77 beam antenna) along with mobile radios having a sensitivity figure of merit (G/T) of -15 dB/deg K are considered. Optimized mobile radio user costs are presented as a function of the number of users with the satellite and mobile radio alternatives as system parameters.

The evolving Planck mass in classically scale-invariant theories

NASA Astrophysics Data System (ADS)

Kannike, K.; Raidal, M.; Spethmann, C.; Veermäe, H.

2017-04-01

We consider classically scale-invariant theories with non-minimally coupled scalar fields, where the Planck mass and the hierarchy of physical scales are dynamically generated. The classical theories possess a fixed point, where scale invariance is spontaneously broken. In these theories, however, the Planck mass becomes unstable in the presence of explicit sources of scale invariance breaking, such as non-relativistic matter and cosmological constant terms. We quantify the constraints on such classical models from Big Bang Nucleosynthesis that lead to an upper bound on the non-minimal coupling and require trans-Planckian field values. We show that quantum corrections to the scalar potential can stabilise the fixed point close to the minimum of the Coleman-Weinberg potential. The time-averaged motion of the evolving fixed point is strongly suppressed, thus the limits on the evolving gravitational constant from Big Bang Nucleosynthesis and other measurements do not presently constrain this class of theories. Field oscillations around the fixed point, if not damped, contribute to the dark matter density of the Universe.

ff14ipq: A Self-Consistent Force Field for Condensed-Phase Simulations of Proteins

PubMed Central

2015-01-01

We present the ff14ipq force field, implementing the previously published IPolQ charge set for simulations of complete proteins. Minor modifications to the charge derivation scheme and van der Waals interactions between polar atoms are introduced. Torsion parameters are developed through a generational learning approach, based on gas-phase MP2/cc-pVTZ single-point energies computed of structures optimized by the force field itself rather than the quantum benchmark. In this manner, we sacrifice information about the true quantum minima in order to ensure that the force field maintains optimal agreement with the MP2/cc-pVTZ benchmark for the ensembles it will actually produce in simulations. A means of making the gas-phase torsion parameters compatible with solution-phase IPolQ charges is presented. The ff14ipq model is an alternative to ff99SB and other Amber force fields for protein simulations in programs that accommodate pair-specific Lennard–Jones combining rules. The force field gives strong performance on α-helical and β-sheet oligopeptides as well as globular proteins over microsecond time scale simulations, although it has not yet been tested in conjunction with lipid and nucleic acid models. We show how our choices in parameter development influence the resulting force field and how other choices that may have appeared reasonable would actually have led to poorer results. The tools we developed may also aid in the development of future fixed-charge and even polarizable biomolecular force fields. PMID:25328495

Reduced bleeding events with subcutaneous administration of recombinant human factor IX in immune-tolerant hemophilia B dogs.

PubMed

Russell, Karen E; Olsen, Eva H N; Raymer, Robin A; Merricks, Elizabeth P; Bellinger, Dwight A; Read, Marjorie S; Rup, Bonita J; Keith, James C; McCarthy, Kyle P; Schaub, Robert G; Nichols, Timothy C

2003-12-15

Intravenous administration of recombinant human factor IX (rhFIX) acutely corrects the coagulopathy in hemophilia B dogs. To date, 20 of 20 dogs developed inhibitory antibodies to the xenoprotein, making it impossible to determine if new human FIX products, formulations, or methods of chronic administration can reduce bleeding frequency. Our goal was to determine whether hemophilia B dogs rendered tolerant to rhFIX would have reduced bleeding episodes while on sustained prophylactic rhFIX administered subcutaneously. Reproducible methods were developed for inducing tolerance to rhFIX in this strain of hemophilia B dogs, resulting in a significant reduction in the development of inhibitors relative to historical controls (5 of 12 versus 20 or 20, P <.001). The 7 of 12 tolerized hemophilia B dogs exhibited shortened whole blood clotting times (WBCTs), sustained detectable FIX antigen, undetectable Bethesda inhibitors, transient or no detectable antihuman FIX antibody titers by enzyme-linked immunosorbent assay (ELISA), and normal clearance of infused rhFIX. Tolerized hemophilia B dogs had 69% reduction in bleeding frequency in year 1 compared with nontolerized hemophilia B dogs (P =.0007). If proven safe in human clinical trials, subcutaneous rhFIX may provide an alternate approach to prophylactic therapy in selected patients with hemophilia B.

Characterization of the exradin W1 plastic scintillation detector for small field applications in proton therapy.

PubMed

Hoehr, C; Lindsay, C; Beaudry, J; Penner, C; Strgar, V; Lee, R; Duzenli, C

2018-05-04

Accurate dosimetry in small field proton therapy is challenging, particularly for applications such as ocular therapy, and suitable detectors for this purpose are sought. The Exradin W1 plastic scintillating fibre detector is known to out-perform most other detectors for determining relative dose factors for small megavoltage photon beams used in radiotherapy but its potential in small proton beams has been relatively unexplored in the literature. The 1 mm diameter cylindrical geometry and near water equivalence of the W1 makes it an attractive alternative to other detectors. This study examines the dosimetric performance of the W1 in a 74 MeV proton therapy beam with particular focus on detector response characteristics relevant to relative dose measurement in small fields suitable for ocular therapy. Quenching of the scintillation signal is characterized and demonstrated not to impede relative dose measurements at a fixed depth. The background cable-only (Čerenkov and radio-fluorescence) signal is 4 orders of magnitude less than the scintillation signal, greatly simplifying relative dose measurements. Comparison with other detectors and Monte Carlo simulations indicate that the W1 is useful for measuring relative dose factors for field sizes down to 5 mm diameter and shallow spread out Bragg peaks down to 6 mm in depth.

Characterization of the exradin W1 plastic scintillation detector for small field applications in proton therapy

NASA Astrophysics Data System (ADS)

Hoehr, C.; Lindsay, C.; Beaudry, J.; Penner, C.; Strgar, V.; Lee, R.; Duzenli, C.

2018-05-01

Accurate dosimetry in small field proton therapy is challenging, particularly for applications such as ocular therapy, and suitable detectors for this purpose are sought. The Exradin W1 plastic scintillating fibre detector is known to out-perform most other detectors for determining relative dose factors for small megavoltage photon beams used in radiotherapy but its potential in small proton beams has been relatively unexplored in the literature. The 1 mm diameter cylindrical geometry and near water equivalence of the W1 makes it an attractive alternative to other detectors. This study examines the dosimetric performance of the W1 in a 74 MeV proton therapy beam with particular focus on detector response characteristics relevant to relative dose measurement in small fields suitable for ocular therapy. Quenching of the scintillation signal is characterized and demonstrated not to impede relative dose measurements at a fixed depth. The background cable-only (Čerenkov and radio-fluorescence) signal is 4 orders of magnitude less than the scintillation signal, greatly simplifying relative dose measurements. Comparison with other detectors and Monte Carlo simulations indicate that the W1 is useful for measuring relative dose factors for field sizes down to 5 mm diameter and shallow spread out Bragg peaks down to 6 mm in depth.

A Diamond Electron Tunneling Micro-Electromechanical Sensor

NASA Technical Reports Server (NTRS)

Albin, Sacharia

2000-01-01

A new pressure sensing device using field emission from diamond coated silicon tips has been developed. A high electric field applied between a nano-tip array and a diaphragm configured as electrodes produces electron emission governed by the Fowler Nordheim equation. The electron emission is very sensitive to the separation between the diaphragm and the tips, which is fixed at an initial spacing and bonded such that a cavity is created between them. Pressure applied to the diaphragm decreases the spacing between the electrodes, thereby increasing the number of electrons emitted. Silicon has been used as a substrate on which arrays of diamond coated sharp tips have been fabricated for electron emission. Also, a diaphragm has been made using wet orientation dependent etching. These two structures were bonded together using epoxy and tested. Current - voltage measurements were made at varying pressures for 1-5 V biasing conditions. The sensitivity was found to be 2.13 mV/V/psi for a 20 x 20 array, which is comparable to that of silicon piezoresistive transducers. Thinner diaphragms as well as alternative methods of bonding are expected to improve the electrical characteristics of the device. This transducer will find applications in many engineering fields for pressure measurement.

Racetrack-shape fixed field induction accelerator for giant cluster ions

NASA Astrophysics Data System (ADS)

Takayama, Ken; Adachi, Toshikazu; Wake, Masayoshi; Okamura, Katsuya

2015-05-01

A novel scheme for a racetrack-shape fixed field induction accelerator (RAFFIA) capable of accelerating extremely heavy cluster ions (giant cluster ions) is described. The key feature of this scheme is rapid induction acceleration by localized induction cells. Triggering the induction voltages provided by the signals from the circulating bunch allows repeated acceleration of extremely heavy cluster ions. The given RAFFIA example is capable of realizing the integrated acceleration voltage of 50 MV per acceleration cycle. Using 90° bending magnets with a reversed field strip and field gradient is crucial for assuring orbit stability in the RAFFIA.

Nonquadratic gauge fixing and ghosts for gauge theories on the hypersphere

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

Brandt, F. T.; McKeon, D. G. C.; Department of Mathematics and Computer Science, Algoma University, Sault St. Marie, Ontario P6A 2G4

2011-10-15

It has been suggested that using a gauge fixing Lagrangian that is not quadratic in a gauge fixing condition is most appropriate for gauge theories formulated on a hypersphere. We reexamine the appropriate ghost action that is to be associated with gauge fixing, applying a technique that has been used for ensuring that the propagator for a massless spin-two field is transverse and traceless. It is shown that this nonquadratic gauge fixing Lagrangian leads to two pair of complex Fermionic ghosts and two Bosonic real ghosts.

Sap fluxes from different parts of the rootzone modulate xylem ABA concentration during partial rootzone drying and re-wetting

PubMed Central

Pérez-Pérez, J. G.; Dodd, I. C.

2015-01-01

Previous studies with partial rootzone drying (PRD) irrigation demonstrated that alternating the wet and dry parts of the rootzone (PRD-Alternated) increased leaf xylem ABA concentration ([X-ABA]leaf) compared with maintaining the same wet and dry parts of the rootzone (PRD-Fixed). To determine the relative contributions of different parts of the rootzone to this ABA signal, [X-ABA]leaf of potted, split-root tomato (Solanum lycopersicum) plants was modelled by quantifying the proportional water uptake from different soil compartments, and [X-ABA]leaf responses to the entire pot soil-water content (θpot). Continuously measuring soil-moisture depletion by, or sap fluxes from, different parts of the root system revealed that water uptake rapidly declined (within hours) after withholding water from part of the rootzone, but was rapidly restored (within minutes) upon re-watering. Two hours after re-watering part of the rootzone, [X-ABA]leaf was equally well predicted according to θpot alone and by accounting for the proportional water uptake from different parts of the rootzone. Six hours after re-watering part of the rootzone, water uptake by roots in drying soil was minimal and, instead, occurred mainly from the newly irrigated part of the rootzone, thus [X-ABA]leaf was best predicted by accounting for the proportional water uptake from different parts of the rootzone. Contrary to previous results, alternating the wet and dry parts of the rootzone did not enhance [X-ABA]leaf compared with PRD-Fixed irrigation. Further work is required to establish whether altered root-to-shoot ABA signalling contributes to the improved yields of crops grown with alternate, rather than fixed, PRD. PMID:25740924

Sap fluxes from different parts of the rootzone modulate xylem ABA concentration during partial rootzone drying and re-wetting.

PubMed

Pérez-Pérez, J G; Dodd, I C

2015-04-01

Previous studies with partial rootzone drying (PRD) irrigation demonstrated that alternating the wet and dry parts of the rootzone (PRD-Alternated) increased leaf xylem ABA concentration ([X-ABA]leaf) compared with maintaining the same wet and dry parts of the rootzone (PRD-Fixed). To determine the relative contributions of different parts of the rootzone to this ABA signal, [X-ABA]leaf of potted, split-root tomato (Solanum lycopersicum) plants was modelled by quantifying the proportional water uptake from different soil compartments, and [X-ABA]leaf responses to the entire pot soil-water content (θpot). Continuously measuring soil-moisture depletion by, or sap fluxes from, different parts of the root system revealed that water uptake rapidly declined (within hours) after withholding water from part of the rootzone, but was rapidly restored (within minutes) upon re-watering. Two hours after re-watering part of the rootzone, [X-ABA]leaf was equally well predicted according to θpot alone and by accounting for the proportional water uptake from different parts of the rootzone. Six hours after re-watering part of the rootzone, water uptake by roots in drying soil was minimal and, instead, occurred mainly from the newly irrigated part of the rootzone, thus [X-ABA]leaf was best predicted by accounting for the proportional water uptake from different parts of the rootzone. Contrary to previous results, alternating the wet and dry parts of the rootzone did not enhance [X-ABA]leaf compared with PRD-Fixed irrigation. Further work is required to establish whether altered root-to-shoot ABA signalling contributes to the improved yields of crops grown with alternate, rather than fixed, PRD. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Joint estimation of high resolution images and depth maps from light field cameras

NASA Astrophysics Data System (ADS)

Ohashi, Kazuki; Takahashi, Keita; Fujii, Toshiaki

2014-03-01

Light field cameras are attracting much attention as tools for acquiring 3D information of a scene through a single camera. The main drawback of typical lenselet-based light field cameras is the limited resolution. This limitation comes from the structure where a microlens array is inserted between the sensor and the main lens. The microlens array projects 4D light field on a single 2D image sensor at the sacrifice of the resolution; the angular resolution and the position resolution trade-off under the fixed resolution of the image sensor. This fundamental trade-off remains after the raw light field image is converted to a set of sub-aperture images. The purpose of our study is to estimate a higher resolution image from low resolution sub-aperture images using a framework of super-resolution reconstruction. In this reconstruction, these sub-aperture images should be registered as accurately as possible. This registration is equivalent to depth estimation. Therefore, we propose a method where super-resolution and depth refinement are performed alternatively. Most of the process of our method is implemented by image processing operations. We present several experimental results using a Lytro camera, where we increased the resolution of a sub-aperture image by three times horizontally and vertically. Our method can produce clearer images compared to the original sub-aperture images and the case without depth refinement.

The next $120,000: a case study to illustrate analysis of alternative farm investments in fixed assets.

PubMed

St-Pierre, N R; Shoemaker, D; Jones, L R

2000-05-01

Dairy scientists specializing in the area of farm management are increasingly involved in analysis of farm investments in fixed assets. There have been instances where the wrong procedures were used to assess investments in fixed assets, leading to erroneous and possibly disastrous conclusions. A detailed case study of a dairy farm facing the decision of where best to invest an unexpected $120,000 windfall is used to illustrate the various facets of financial analysis. Indicators of profitability, liquidity, solvency, repayment capacity, and financial efficiency are explained and applied to the farm case to produce a detailed analysis of the current financial position of the firm. Long-range budgets of four alternate investment options and their impact on all financial indicators are presented. The four options are: 1) to pay down debt, 2) to purchase an additional 100 cows, 3) to install automatic milk yield recording in the parlor, and 4) to build new heifer facilities. All four investments are profitable. Therefore, an analysis limited to profitability indicators would conclude that any of the four options is a good investment. However, liquidity and financial efficiency issues showed that the option of purchasing 100 cows is far superior to the three others. We conclude that a complete and thorough financial analysis is required to evaluate the impact of long-run investments in fixed assets.

Using biologically-fixed nitrogen by native plants to enhance growth of hardwood saplings

Treesearch

J.W. Van Sambeek; Nadia E. Navarrete-Tindall

2013-01-01

Available soil nitrogen is frequently low in old-field plantings. Underplanting forage legumes and interplanting nitrogen-fixing shrubs can improve growth of hardwood saplings, especially black walnut and pecan. Most of the nitrogen-fixing shrubs and forbs have been introduced, and several are now considered invasive species. Research trials have been established on...

Application of the magnetic fluid as a detector for changing the magnetic field

NASA Astrophysics Data System (ADS)

Zyatkov, D.; Yurchenko, A.; Yurchenko, V.; Balashov, V.

2018-05-01

In article the possibility of use of magnetic fluid as a sensitive element for fixing of change of induction of magnetic field in space is considered. Importance of solvable tasks is connected with search of the perspective magnetic substances susceptible to weak magnetic field. The results of a study of the capacitive method for fixing the change in the magnetic field on the basis of a ferromagnetic liquid are presented. The formation of chain structures in the ferrofluid from magnetic particles under the influence of the applied magnetic field leads to a change in the capacitance of the plate condenser. This task has important practical value for development of a magnetosensitive sensor of change of magnetic field.

Teaching an Old Dog an Old Trick: FREE-FIX and Free-Boundary Axisymmetric MHD Equilibrium

NASA Astrophysics Data System (ADS)

Guazzotto, Luca

2015-11-01

A common task in plasma physics research is the calculation of an axisymmetric equilibrium for tokamak modeling. The main unknown of the problem is the magnetic poloidal flux ψ. The easiest approach is to assign the shape of the plasma and only solve the equilibrium problem in the plasma / closed-field-lines region (the ``fixed-boundary approach''). Often, one may also need the vacuum fields, i.e. the equilibrium in the open-field-lines region, requiring either coil currents or ψ on some closed curve outside the plasma to be assigned (the ``free-boundary approach''). Going from one approach to the other is a textbook problem, involving the calculation of Green's functions and surface integrals in the plasma. However, no tools are readily available to perform this task. Here we present a code (FREE-FIX) to compute a boundary condition for a free-boundary equilibrium given only the corresponding fixed-boundary equilibrium. An improvement to the standard solution method, allowing for much faster calculations, is presented. Applications are discussed. PPPL fund 245139 and DOE grant G00009102.

AC electroosmosis in microchannels packed with a porous medium

NASA Astrophysics Data System (ADS)

Kang, Yuejun; Yang, Chun; Huang, Xiaoyang

2004-08-01

This paper presents a theoretical study on ac-driven electroosmotic flow in both open-end and closed-end microchannels packed with uniform charged spherical microparticles. The time-periodic oscillating electroosmotic flow in an open-end capillary in response to the application of an alternating (ac) electric field is obtained using the Green function approach. The analysis is based on the Carman-Kozeny theory. The backpressure associated with the counter-flow in a closed-end capillary is obtained by analytically solving the modified Brinkman momentum equation. It is demonstrated that in a microchannel with its two ends connected to reservoirs and subject to ambient pressure, the oscillating Darcy velocity profile depends on both the pore size and the excitation frequency; such effects are coupled through an important aspect ratio of the tubule radius to the Stokes penetration depth. For a fixed pore size, the magnitude of the ac electroosmotic flow decreases with increasing frequency. With increasing pore size, however, the magnitude of the maximum velocity shows two different trends with respect to the excitation frequency: it gets higher in the low frequency domain, and gets lower in the high frequency domain. In a microchannel with closed ends, for a fixed excitation frequency, use of smaller packing particles can generate higher backpressure. For a fixed pore size, the backpressure magnitude shows two different trends changing with the excitation frequency. When the excitation frequency is lower than the system characteristic frequency, the backpressure decreases with increasing excitation frequency. When the excitation frequency is higher than the system characteristic frequency, the backpressure increases with increasing excitation frequency.

Suprathreshold contrast summation over area using drifting gratings.

PubMed

McDougall, Thomas J; Dickinson, J Edwin; Badcock, David R

2018-04-01

This study investigated contrast summation over area for moving targets applied to a fixed-size contrast pedestal-a technique originally developed by Meese and Summers (2007) to demonstrate strong spatial summation of contrast for static patterns at suprathreshold contrast levels. Target contrast increments (drifting gratings) were applied to either the entire 20% contrast pedestal (a full fixed-size drifting grating), or in the configuration of a checkerboard pattern in which the target increment was applied to every alternate check region. These checked stimuli are known as "Battenberg patterns" and the sizes of the checks were varied (within a fixed overall area), across conditions, to measure summation behavior. Results showed that sensitivity to an increment covering the full pedestal was significantly higher than that for the Battenberg patterns (areal summation). Two observers showed strong summation across all check sizes (0.71°-3.33°), and for two other observers the summation ratio dropped to levels consistent with probability summation once check size reached 2.00°. Therefore, areal summation with moving targets does operate at high contrast, and is subserved by relatively large receptive fields covering a square area extending up to at least 3.33° × 3.33° for some observers. Previous studies in which the spatial structure of the pedestal and target covaried were unable to demonstrate spatial summation, potentially due to increasing amounts of suppression from gain-control mechanisms which increases as pedestal size increases. This study shows that when this is controlled, by keeping the pedestal the same across all conditions, extensive summation can be demonstrated.

Spectrum efficient distance-adaptive paths for fixed and fixed-alternate routing in elastic optical networks

NASA Astrophysics Data System (ADS)

Agrawal, Anuj; Bhatia, Vimal; Prakash, Shashi

2018-01-01

Efficient utilization of spectrum is a key concern in the soon to be deployed elastic optical networks (EONs). To perform routing in EONs, various fixed routing (FR), and fixed-alternate routing (FAR) schemes are ubiquitously used. FR, and FAR schemes calculate a fixed route, and a prioritized list of a number of alternate routes, respectively, between different pairs of origin o and target t nodes in the network. The route calculation performed using FR and FAR schemes is predominantly based on either the physical distance, known as k -shortest paths (KSP), or on the hop count (HC). For survivable optical networks, FAR usually calculates link-disjoint (LD) paths. These conventional routing schemes have been efficiently used for decades in communication networks. However, in this paper, it has been demonstrated that these commonly used routing schemes cannot utilize the network spectral resources optimally in the newly introduced EONs. Thus, we propose a new routing scheme for EON, namely, k -distance adaptive paths (KDAP) that efficiently utilizes the benefit of distance-adaptive modulation, and bit rate-adaptive superchannel capability inherited by EON to improve spectrum utilization. In the proposed KDAP, routes are found and prioritized on the basis of bit rate, distance, spectrum granularity, and the number of links used for a particular route. To evaluate the performance of KSP, HC, LD, and the proposed KDAP, simulations have been performed for three different sized networks, namely, 7-node test network (TEST7), NSFNET, and 24-node US backbone network (UBN24). We comprehensively assess the performance of various conventional, and the proposed routing schemes by solving both the RSA and the dual RSA problems under homogeneous and heterogeneous traffic requirements. Simulation results demonstrate that there is a variation amongst the performance of KSP, HC, and LD, depending on the o - t pair, and the network topology and its connectivity. However, the proposed KDAP always performs better for all the considered networks and traffic scenarios, as compared to the conventional routing schemes, namely, KSP, HC, and LD. The proposed KDAP achieves up to 60 % , and 10.46 % improvement in terms of spectrum utilization, and resource utilization ratio, respectively, over the conventional routing schemes.

Systemic delivery of factor IX messenger RNA for protein replacement therapy

PubMed Central

Ramaswamy, Suvasini; Tonnu, Nina; Tachikawa, Kiyoshi; Limphong, Pattraranee; Vega, Jerel B.; Karmali, Priya P.; Chivukula, Pad; Verma, Inder M.

2017-01-01

Safe and efficient delivery of messenger RNAs for protein replacement therapies offers great promise but remains challenging. In this report, we demonstrate systemic, in vivo, nonviral mRNA delivery through lipid nanoparticles (LNPs) to treat a Factor IX (FIX)-deficient mouse model of hemophilia B. Delivery of human FIX (hFIX) mRNA encapsulated in our LUNAR LNPs results in a rapid pulse of FIX protein (within 4–6 h) that remains stable for up to 4–6 d and is therapeutically effective, like the recombinant human factor IX protein (rhFIX) that is the current standard of care. Extensive cytokine and liver enzyme profiling showed that repeated administration of the mRNA–LUNAR complex does not cause any adverse innate or adaptive immune responses in immune-competent, hemophilic mice. The levels of hFIX protein that were produced also remained consistent during repeated administrations. These results suggest that delivery of long mRNAs is a viable therapeutic alternative for many clotting disorders and for other hepatic diseases where recombinant proteins may be unaffordable or unsuitable. PMID:28202722

RESOLFT nanoscopy with photoswitchable organic fluorophores

NASA Astrophysics Data System (ADS)

Kwon, Jiwoong; Hwang, Jihee; Park, Jaewan; Han, Gi Rim; Han, Kyu Young; Kim, Seong Keun

2015-12-01

Far-field optical nanoscopy has been widely used to image small objects with sub-diffraction-limit spatial resolution. Particularly, reversible saturable optical fluorescence transition (RESOLFT) nanoscopy with photoswitchable fluorescent proteins is a powerful method for super-resolution imaging of living cells with low light intensity. Here we demonstrate for the first time the implementation of RESOLFT nanoscopy for a biological system using organic fluorophores, which are smaller in size and easier to be chemically modified. With a covalently-linked dye pair of Cy3 and Alexa647 to label subcellular structures in fixed cells and by optimizing the imaging buffer and optical parameters, our RESOLFT nanoscopy achieved a spatial resolution of ~74 nm in the focal plane. This method provides a powerful alternative for low light intensity RESOLFT nanoscopy, which enables biological imaging with small organic probes at nanoscale resolution.

Principal Component Analysis of Thermographic Data

NASA Technical Reports Server (NTRS)

Winfree, William P.; Cramer, K. Elliott; Zalameda, Joseph N.; Howell, Patricia A.; Burke, Eric R.

2015-01-01

Principal Component Analysis (PCA) has been shown effective for reducing thermographic NDE data. While a reliable technique for enhancing the visibility of defects in thermal data, PCA can be computationally intense and time consuming when applied to the large data sets typical in thermography. Additionally, PCA can experience problems when very large defects are present (defects that dominate the field-of-view), since the calculation of the eigenvectors is now governed by the presence of the defect, not the "good" material. To increase the processing speed and to minimize the negative effects of large defects, an alternative method of PCA is being pursued where a fixed set of eigenvectors, generated from an analytic model of the thermal response of the material under examination, is used to process the thermal data from composite materials. This method has been applied for characterization of flaws.

A new patent-based approach for technology mapping in the pharmaceutical domain.

PubMed

Russo, Davide; Montecchi, Tiziano; Carrara, Paolo

2013-09-01

The key factor in decision-making is the quality of information collected and processed in the problem analysis. In most cases, patents represent a very important source of information. The main problem is how to extract such information from the huge corpus of documents with a high recall and precision, and in a short time. This article demonstrates a patent search and classification method, called Knowledge Organizing Module, which consists of creating, almost automatically, a pool of patents based on polysemy expansion and homonymy disambiguation. Since the pool is done, an automatic patent technology landscaping is provided for fixing the state of the art of our product, and exploring competing alternative treatments and/or possible technological opportunities. An exemplary case study is provided, it deals with a patent analysis in the field of verruca treatments.

Accelerators for charged particle therapy: PAMELA and related issues

NASA Astrophysics Data System (ADS)

Peach, Ken

2014-05-01

Cancer is a dreadful disease that will affect one in three people at some point in their life; radiotherapy is used in more than half of all cancer treatment, and contributes about 40% to the successful treatment of cancer. Charged Particle Therapy uses protons and other light ions to deliver the lethal dose to the tumor while being relatively sparing of healthy tissue and, because of the finite range of the particles, is able to avoid giving any dose to vital organs. While there are adequate technologies currently available to deliver the required energies and fluxes, the two main technologies (cyclotrons and synchrotrons) have limitations. PAMELA (the Particle Accelerator for MEdicaLApplications) uses the newly-developed non-scaling Fixed Field Alternating Gradient accelerator concepts to deliver therapeutically relevant beams. The status of the development of the PAMELA conceptual design is discussed.

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

Brihaye, Yves; Delsate, Terence; Kodama, Yuta

We consider a six-dimensional brane world model, where the brane is described by a localized solution to the baby-Skyrme model extending in the extra dimensions. The branes have a cosmological constant modeled by inflating four-dimensional slices, and we further consider a bulk cosmological constant. We construct solutions numerically and present evidence that the solutions cease to exist for large values of the brane cosmological constant in some particular case. Then we study the stability of the model by considering perturbation of the gravitational part (resp. baby Skyrmion) with fixed matter fields (resp. gravitational background). Our results indicate that the perturbationmore » equations do not admit localized solutions for certain type of perturbation. The stability analysis can be alternatively seen as leading to a particle spectrum; we give mass estimations for the baby-Skyrme perturbation and for the graviton.« less

Equivalent source modeling of the core magnetic field using magsat data

NASA Technical Reports Server (NTRS)

Mayhew, M. A.; Estes, R. H.

1983-01-01

Experiments are carried out on fitting the main field using different numbers of equivalent sources arranged in equal area at fixed radii at and inside the core-mantle boundary. In fixing the radius for a given series of runs, the convergence problems that result from the extreme nonlinearity of the problem when dipole positions are allowed to vary are avoided. Results are presented from a comparison between this approach and the standard spherical harmonic approach for modeling the main field in terms of accuracy and computational efficiency. The modeling of the main field with an equivalent dipole representation is found to be comparable to the standard spherical harmonic approach in accuracy. The 32 deg dipole density (42 dipoles) corresponds approximately to an eleventh degree/order spherical harmonic expansion (143 parameters), whereas the 21 dipole density (92 dipoles) corresponds to approximately a seventeenth degree and order expansion (323 parameters). It is pointed out that fixing the dipole positions results in rapid convergence of the dipole solutions for single-epoch models.

76 FR 35181 - Wireless Backhaul; Further Inquiry Into Fixed Service Sharing of the 6875-7125 and 12700-13200...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-16

... continuation of electronic newsgathering operations, and the appropriate channelization scheme, coordination... also sought comment on alternative channelization schemes. Several commenters, including FWCC and...

Isotopic Biomarkers of Nitrogenase Metalloenzymes: Forging Links Between the Cycles of Nitrogen and Trace Metals

NASA Astrophysics Data System (ADS)

Zhang, X.; McRose, D. L.; Darnajoux, R.; Bellenger, J. P.; Kraepiel, A. M. L.

2015-12-01

Biological N2 fixation, catalyzed by the metalloenzyme nitrogenase, is a critical process that makes life possible on Earth. Environmental N2 fixation has been automatically attributed to canonical Mo-based nitrogenases despite over two decades of knowledge that two other metalloenzyme forms of nitrogenase exist: those containing catalytic V or Fe-only. A key area of missing information is the contribution of the "alternative" V and Fe-only nitrogenases, as the interpretation of field data to construct budgets and assess N availability depends on the type of nitrogenase metalloenzyme used to fix N2. Additionally, substantial changes in metal speciation over geological time may have favored the use of different metalloenzymes, with implications for evolution of the biosphere. Despite the potential importance of alternative nitrogenases in modern and ancient N cycling, few methods can determine their contributions to environmental N2 fixation. Here, we present new isotopic methods to distinguish between the activities of Mo, V, and Fe-only nitrogenases. We show evidence for alternative N2 fixation in diverse environments (cyanolichens, microbial mats, sediments, leaf litter), thereby linking a key process in the nitrogen cycle to specific metalloenzyme forms of nitrogenase. The results invite a reexamination of the conditions under which the different nitrogenase metalloenzymes are active and may lead to new insights into the coupling of the cycles of nitrogen and trace metals.

Performance determinants of fixed gear cycling during criteriums.

PubMed

Babault, Nicolas; Poisson, Maxime; Cimadoro, Guiseppe; Cometti, Carole; Païzis, Christos

2018-06-17

Nowadays, fixed gear competitions on outdoor circuits such as criteriums are regularly organized worldwide. To date, no study has investigated this alternative form of cycling. The purpose of the present study was to examine fixed gear performance indexes and to characterize physiological determinants of fixed gear cyclists. This study was carried out in two parts. Part 1 (n = 36) examined correlations between performance indexes obtained during a real fixed gear criterium (time trial, fastest laps, averaged lap time during races, fatigue indexes) and during a sprint track time trial. Part 2 (n = 9) examined correlations between the recorded performance indexes and some aerobic and anaerobic performance outputs (VO 2max , maximal aerobic power, knee extensor and knee flexor maximal voluntary torque, vertical jump height and performance during a modified Wingate test). Results from Part 1 indicated significant correlations between fixed gear final performance (i.e. average lap time during the finals) and single lap time (time trial, fastest lap during races and sprint track time trial). In addition, results from Part 2 revealed significant correlations between fixed gear performance and aerobic indicators (VO 2max and maximal aerobic power). However, no significant relationship was obtained between fixed gear cycling and anaerobic qualities such as strength. Similarly to traditional cycling disciplines, we concluded that fixed gear cycling is mainly limited by aerobic capacity, particularly criteriums final performance. However, specific skills including technical competency should be considered.

Time-periodic solutions of driven-damped trimer granular crystals

DOE PAGES

Charalampidis, E. G.; Li, F.; Chong, C.; ...

2015-01-01

In this work, we consider time-periodic structures of granular crystals consisting of alternate chrome steel (S) and tungsten carbide (W) spherical particles where each unit cell follows the pattern of a 2:1 trimer: S-W-S. The configuration at the left boundary is driven by a harmonic in-time actuation with given amplitude and frequency while the right one is a fixed wall. Similar to the case of a dimer chain, the combination of dissipation, driving of the boundary, and intrinsic nonlinearity leads to complex dynamics. For fixed driving frequencies in each of the spectral gaps, we find that the nonlinear surface modesmore » and the states dictated by the linear drive collide in a saddle-node bifurcation as the driving amplitude is increased, beyond which the dynamics of the system becomes chaotic. While the bifurcation structure is similar for solutions within the first and second gap, those in the first gap appear to be less robust. We also conduct a continuation in driving frequency, where it is apparent that the nonlinearity of the system results in a complex bifurcation diagram, involving an intricate set of loops of branches, especially within the spectral gap. The theoretical findings are qualitatively corroborated by the experimental full-field visualization of the time-periodic structures.« less

Metallic and antiferromagnetic fixed points from gravity

NASA Astrophysics Data System (ADS)

Paul, Chandrima

2018-06-01

We consider SU(2) × U(1) gauge theory coupled to matter field in adjoints and study RG group flow. We constructed Callan-Symanzik equation and subsequent β functions and study the fixed points. We find there are two fixed points, showing metallic and antiferromagnetic behavior. We have shown that metallic phase develops an instability if certain parametric conditions are satisfied.

An alternative technique in the treatment of anterior cross bite in a case of Nickel allergy: a case report.

PubMed

Giancotti, A; Mozzicato, P; Mampieri, G

2011-03-01

The objective of this paper is to show an alternative use of an Essix based appliance in the treatment of anterior single-tooth crossbite malocclusion in a patient with Nickel allergy. Anterior crossbite malocclusion of one or more teeth, without posterior crossbite association, is a relatively frequent condition both in the mixed and the permanent dentition. This kind of malocclusion is usually treated with either fixed or removable appliances. The use of preformed Essix appliances could be an alternative to traditional removable and fixed orthodontic devices in patients with Nickel allergy as well as in every patient. The treatment was successfully completed in 12 weeks, the anterior single tooth crossbite was corrected using three full arch Essix-based appliances planned on the set-up casting, providing a gradual vestibular movement. Patient compliance was requested in order to provide the planned dental movement. The Essix appliance can be successfully used to correct a single-tooth crossbite even in allergic subjects in a short time with patient cooperation.

Obstacle-avoiding navigation system

DOEpatents

Borenstein, Johann; Koren, Yoram; Levine, Simon P.

1991-01-01

A system for guiding an autonomous or semi-autonomous vehicle through a field of operation having obstacles thereon to be avoided employs a memory for containing data which defines an array of grid cells which correspond to respective subfields in the field of operation of the vehicle. Each grid cell in the memory contains a value which is indicative of the likelihood, or probability, that an obstacle is present in the respectively associated subfield. The values in the grid cells are incremented individually in response to each scan of the subfields, and precomputation and use of a look-up table avoids complex trigonometric functions. A further array of grid cells is fixed with respect to the vehicle form a conceptual active window which overlies the incremented grid cells. Thus, when the cells in the active window overly grid cell having values which are indicative of the presence of obstacles, the value therein is used as a multiplier of the precomputed vectorial values. The resulting plurality of vectorial values are summed vectorially in one embodiment of the invention to produce a virtual composite repulsive vector which is then summed vectorially with a target-directed vector for producing a resultant vector for guiding the vehicle. In an alternative embodiment, a plurality of vectors surrounding the vehicle are computed, each having a value corresponding to obstacle density. In such an embodiment, target location information is used to select between alternative directions of travel having low associated obstacle densities.

Fully Resolved Simulations of Particle-Bed-Turbulence Interactions in Oscillatory Flows

NASA Astrophysics Data System (ADS)

Apte, S.; Ghodke, C.

2017-12-01

Particle-resolved direct numerical simulations (DNS) are performed to investigate the behavior of an oscillatory flow field over a bed of closely packed fixed spherical particles for a range of Reynolds numbers in transitional and rough turbulent flow regime. Presence of roughness leads to a substantial modification of the underlying boundary layer mechanism resulting in increased bed shear stress, reduction in the near-bed anisotropy, modification of the near-bed sweep and ejection motions along with marked changes in turbulent energy transport mechanisms. Characterization of such resulting flow field is performed by studying statistical descriptions of the near-bed turbulence for different roughness parameters. A double-averaging technique is employed to reveal spatial inhomogeneities at the roughness scale that provide alternate paths of energy transport in the turbulent kinetic energy (TKE) budget. Spatio-temporal characteristics of unsteady particle forces by studying their spatial distribution, temporal auto-correlations, frequency spectra, cross-correlations with near-bed turbulent flow variables and intermittency intermittency in the forces using the concept of impulse are investigated in detail. These first principle simulations provide substantial insights into the modeling of incipient motion of sediments.

The effect of 1/f fluctuation in inter-stimulus intervals on auditory evoked mismatch field.

PubMed

Harada, Nobuyoshi; Masuda, Tadashi; Endo, Hiroshi; Nakamura, Yukihiro; Takeda, Tsunehiro; Tonoike, Mitsuo

2005-05-13

This study focused on the effect of regularity of environmental stimuli on the informational order extracting function of human brain. The regularity of environmental stimuli can be described with the exponent n of the fluctuation 1/f(n). We studied the effect of the exponent of the fluctuation in the inter-stimulus interval (ISI) on the elicitation of auditory evoked mismatch fields (MMF) with two sounds with alternating frequency. ISI times were given by three types of fluctuation, 1/f(0), 1/f(1), 1/f(2), and with a fixed interval (1/f(infinity)). The root mean square (RMS) value of the MMF increased significantly (F(3/9)=4.95, p=0.027) with increases in the exponent of the fluctuation. Increments in the regularity of the fluctuation provoked enhancement of the MMF, which reflected the production of a memory trace, based on the anticipation of the stimulus timing. The gradient of the curve, indicating the ratio of increments between the MMF and the exponent of fluctuation, can express a subject's capability to extract regularity from fluctuating stimuli.

Practical fit functions for transport critical current versus field magnitude and angle data from (RE)BCO coated conductors at fixed low temperatures and in high magnetic fields

NASA Astrophysics Data System (ADS)

Hilton, D. K.; Gavrilin, A. V.; Trociewitz, U. P.

2015-07-01

Applications of (RE = Y, Gd)BCO coated conductors for the generation of high magnetic fields are increasing sharply, this while (RE)BCO coated conductors themselves are evolving rapidly. This article describes and demonstrates recently developed and applied mathematical models that systematically and comprehensively characterize the transport critical current angular dependence of a batch of (RE)BCO coated conductor in high magnetic fields at fixed temperatures with an uncertainty of 10% or better. The model development was based on analysis of experimental data sets from various published sources and coated conductors with different microstructures. These derivations directly are applicable to the accurate prediction of the performance in high magnetic fields of coils wound with (RE)BCO coated conductors. In particular, a nonlinear fit is discussed in this article of transport critical current at T = 4.2 K versus field and angle data. This fit was used to estimate the hysteresis losses of (RE)BCO coated conductors in high magnetic fields, and to design the inserts wound with such conductors of the all-superconducting 32 T magnet being constructed at the NHMFL. A series of such fits, recently developed at several fixed temperatures, continues to be used to simulate the quench behavior of that magnet.

Cells and Stripes: A novel quantitative photo-manipulation technique

PubMed Central

Mistrik, Martin; Vesela, Eva; Furst, Tomas; Hanzlikova, Hana; Frydrych, Ivo; Gursky, Jan; Majera, Dusana; Bartek, Jiri

2016-01-01

Laser micro-irradiation is a technology widely used in the DNA damage response, checkpoint signaling, chromatin remodeling and related research fields, to assess chromatin modifications and recruitment of diverse DNA damage sensors, mediators and repair proteins to sites of DNA lesions. While this approach has aided numerous discoveries related to cell biology, maintenance of genome integrity, aging and cancer, it has so far been limited by a tedious manual definition of laser-irradiated subcellular regions, with the ensuing restriction to only a small number of cells treated and analyzed in a single experiment. Here, we present an improved and versatile alternative to the micro-irradiation approach: Quantitative analysis of photo-manipulated samples using innovative settings of standard laser-scanning microscopes. Up to 200 cells are simultaneously exposed to a laser beam in a defined pattern of collinear rays. The induced striation pattern is then automatically evaluated by a simple algorithm, which provides a quantitative assessment of various laser-induced phenotypes in live or fixed cells. Overall, this new approach represents a more robust alternative to existing techniques, and provides a versatile tool for a wide range of applications in biomedicine. PMID:26777522

A model for complex flows of soft glassy materials with application to flows through fixed fiber beds

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

Sarkar, Arijit; Koch, Donald L., E-mail: dlk15@cornell.edu

2015-11-15

The soft glassy rheology (SGR) model has successfully described the time dependent simple shear rheology of a broad class of complex fluids including foams, concentrated emulsions, colloidal glasses, and solvent-free nanoparticle-organic hybrid materials (NOHMs). The model considers a distribution of mesoscopic fluid elements that hop from trap to trap at a rate which is enhanced by the work done to strain the fluid element. While an SGR fluid has a broad exponential distribution of trap energies, the rheology of NOHMs is better described by a narrower energy distribution and we consider both types of trap energy distributions in this study.more » We introduce a tensorial version of these models with a hopping rate that depends on the orientation of the element relative to the mean stress field, allowing a range of relative strengths of the extensional and simple shear responses of the fluid. As an application of these models we consider the flow of a soft glassy material through a dilute fixed bed of fibers. The dilute fixed bed exhibits a range of local linear flows which alternate in a chaotic manner with time in a Lagrangian reference frame. It is amenable to an analytical treatment and has been used to characterize the strong flow response of many complex fluids including fiber suspensions, dilute polymer solutions and emulsions. We show that the accumulated strain in the fluid elements has an abrupt nonlinear growth at a Deborah number of order one in a manner similar to that observed for polymer solutions. The exponential dependence of the hopping rate on strain leads to a fluid element deformation that grows logarithmically with Deborah number at high Deborah numbers. SGR fluids having a broad range of trap energies flowing through fixed beds can exhibit a range of rheological behaviors at small Deborah numbers ranging from a yield stress, to a power law response and finally to Newtonian behavior.« less

Treating childhood pneumonia in hard-to-reach areas: a model-based comparison of mobile clinics and community-based care.

PubMed

Pitt, Catherine; Roberts, Bayard; Checchi, Francesco

2012-01-10

Where hard-to-access populations (such as those living in insecure areas) lack access to basic health services, relief agencies, donors, and ministries of health face a dilemma in selecting the most effective intervention strategy. This paper uses a decision mathematical model to estimate the relative effectiveness of two alternative strategies, mobile clinics and fixed community-based health services, for antibiotic treatment of childhood pneumonia, the world's leading cause of child mortality. A "Markov cycle tree" cohort model was developed in Excel with Visual Basic to compare the number of deaths from pneumonia in children aged 1 to 59 months expected under three scenarios: 1) No curative services available, 2) Curative services provided by a highly-skilled but intermittent mobile clinic, and 3) Curative services provided by a low-skilled community health post. Parameter values were informed by literature and expert interviews. Probabilistic sensitivity analyses were conducted for several plausible scenarios. We estimated median pneumonia-specific under-5 mortality rates of 0.51 (95% credible interval: 0.49 to 0.541) deaths per 10,000 child-days without treatment, 0.45 (95% CI: 0.43 to 0.48) with weekly mobile clinics, and 0.31 (95% CI: 0.29 to 0.32) with CHWs in fixed health posts. Sensitivity analyses found the fixed strategy superior, except when mobile clinics visited communities daily, where rates of care-seeking were substantially higher at mobile clinics than fixed posts, or where several variables simultaneously differed substantially from our baseline assumptions. Current evidence does not support the hypothesis that mobile clinics are more effective than CHWs. A CHW strategy therefore warrants consideration in high-mortality, hard-to-access areas. Uncertainty remains, and parameter values may vary across contexts, but the model allows preliminary findings to be updated as new or context-specific evidence becomes available. Decision analytic modelling can guide needed field-based research efforts in hard-to-access areas and offer evidence-based insights for decision-makers.

The Holographic F Theorem

NASA Astrophysics Data System (ADS)

Taylor, Marika; Woodhead, William

2017-12-01

The F theorem states that, for a unitary three dimensional quantum field theory, the F quantity defined in terms of the partition function on a three sphere is positive, stationary at fixed point and decreases monotonically along a renormalization group flow. We construct holographic renormalization group flows corresponding to relevant deformations of three-dimensional conformal field theories on spheres, working to quadratic order in the source. For these renormalization group flows, the F quantity at the IR fixed point is always less than F at the UV fixed point, but F increases along the RG flow for deformations by operators of dimension between 3/2 and 5/2. Therefore the strongest version of the F theorem is in general violated.

Supersymmetric interactions of a six-dimensional self-dual tensor and fixed-shape second quantized strings

NASA Astrophysics Data System (ADS)

Ganor, Ori J.

2018-02-01

"Curvepole (2,0)-theory" is a deformation of the (2,0)-theory with nonlocal interactions. A curvepole is defined as a two-dimensional generalization of a dipole. It is an object of fixed two-dimensional shape of which the boundary is a charged curve that interacts with a 2-form gauge field. Curvepole theory was previously only defined indirectly via M-theory. Here, we propose a supersymmetric Lagrangian, constructed explicitly up to quartic terms, for an "Abelian" curvepole theory, which is an interacting deformation of the free (2,0) tensor multiplet. This theory contains fields of which the quanta are curvepoles (i.e., fixed-shape strings). Supersymmetry is preserved (at least up to quartic terms) if the shape of the curvepoles is (two-dimensional) planar. This nonlocal six-dimensional quantum field theory may also serve as a UV completion for certain (local) five-dimensional gauge theories.

Unmasking the masked Universe: the 2M++ catalogue through Bayesian eyes

NASA Astrophysics Data System (ADS)

Lavaux, Guilhem; Jasche, Jens

2016-01-01

This work describes a full Bayesian analysis of the Nearby Universe as traced by galaxies of the 2M++ survey. The analysis is run in two sequential steps. The first step self-consistently derives the luminosity-dependent galaxy biases, the power spectrum of matter fluctuations and matter density fields within a Gaussian statistic approximation. The second step makes a detailed analysis of the three-dimensional large-scale structures, assuming a fixed bias model and a fixed cosmology. This second step allows for the reconstruction of both the final density field and the initial conditions at z = 1000 assuming a fixed bias model. From these, we derive fields that self-consistently extrapolate the observed large-scale structures. We give two examples of these extrapolation and their utility for the detection of structures: the visibility of the Sloan Great Wall, and the detection and characterization of the Local Void using DIVA, a Lagrangian based technique to classify structures.

Quantifying the impact of time-varying baseline risk adjustment in the self-controlled risk interval design.

PubMed

Li, Lingling; Kulldorff, Martin; Russek-Cohen, Estelle; Kawai, Alison Tse; Hua, Wei

2015-12-01

The self-controlled risk interval design is commonly used to assess the association between an acute exposure and an adverse event of interest, implicitly adjusting for fixed, non-time-varying covariates. Explicit adjustment needs to be made for time-varying covariates, for example, age in young children. It can be performed via either a fixed or random adjustment. The random-adjustment approach can provide valid point and interval estimates but requires access to individual-level data for an unexposed baseline sample. The fixed-adjustment approach does not have this requirement and will provide a valid point estimate but may underestimate the variance. We conducted a comprehensive simulation study to evaluate their performance. We designed the simulation study using empirical data from the Food and Drug Administration-sponsored Mini-Sentinel Post-licensure Rapid Immunization Safety Monitoring Rotavirus Vaccines and Intussusception study in children 5-36.9 weeks of age. The time-varying confounder is age. We considered a variety of design parameters including sample size, relative risk, time-varying baseline risks, and risk interval length. The random-adjustment approach has very good performance in almost all considered settings. The fixed-adjustment approach can be used as a good alternative when the number of events used to estimate the time-varying baseline risks is at least the number of events used to estimate the relative risk, which is almost always the case. We successfully identified settings in which the fixed-adjustment approach can be used as a good alternative and provided guidelines on the selection and implementation of appropriate analyses for the self-controlled risk interval design. Copyright © 2015 John Wiley & Sons, Ltd.

Different Relative Orientation of Static and Alternative Magnetic Fields and Cress Roots Direction of Growth Changes Their Gravitropic Reaction

NASA Astrophysics Data System (ADS)

Sheykina, Nadiia; Bogatina, Nina

The following variants of roots location relatively to static and alternative components of magnetic field were studied. At first variant the static magnetic field was directed parallel to the gravitation vector, the alternative magnetic field was directed perpendicular to static one; roots were directed perpendicular to both two fields’ components and gravitation vector. At the variant the negative gravitropysm for cress roots was observed. At second variant the static magnetic field was directed parallel to the gravitation vector, the alternative magnetic field was directed perpendicular to static one; roots were directed parallel to alternative magnetic field. At third variant the alternative magnetic field was directed parallel to the gravitation vector, the static magnetic field was directed perpendicular to the gravitation vector, roots were directed perpendicular to both two fields components and gravitation vector; At forth variant the alternative magnetic field was directed parallel to the gravitation vector, the static magnetic field was directed perpendicular to the gravitation vector, roots were directed parallel to static magnetic field. In all cases studied the alternative magnetic field frequency was equal to Ca ions cyclotron frequency. In 2, 3 and 4 variants gravitropism was positive. But the gravitropic reaction speeds were different. In second and forth variants the gravitropic reaction speed in error limits coincided with the gravitropic reaction speed under Earth’s conditions. At third variant the gravitropic reaction speed was slowed essentially.

Multi-criteria analysis towards the new end use of recycled water for household laundry: a case study in Sydney.

PubMed

Chen, Z; Ngo, H H; Guo, W S; Listowski, A; O'Halloran, K; Thompson, M; Muthukaruppan, M

2012-11-01

This paper aims to put forward several management alternatives regarding the application of recycled water for household laundry in Sydney. Based on different recycled water treatment techniques such as microfiltration (MF), granular activated carbon (GAC) or reverse osmosis (RO), and types of washing machines (WMs), five alternatives were proposed as follows: (1) do nothing scenario; (2) MF+existing WMs; (3) MF+new WMs; (4) MF-GAC+existing WMs; and (5) MF-RO+existing WMs. Accordingly, a comprehensive quantitative assessment on the trade-off among a variety of issues (e.g., engineering feasibility, initial cost, energy consumption, supply flexibility and water savings) was performed over the alternatives. This was achieved by a computer-based multi-criteria analysis (MCA) using the rank order weight generation together with preference ranking organization method for enrichment evaluation (PROMETHEE) outranking techniques. Particularly, the generated 10,000 combinations of weights via Monte Carlo simulation were able to significantly reduce the man-made errors of single fixed set of weights because of its objectivity and high efficiency. To illustrate the methodology, a case study on Rouse Hill Development Area (RHDA), Sydney, Australia was carried out afterwards. The study was concluded by highlighting the feasibility of using highly treated recycled water for existing and new washing machines. This could provide a powerful guidance for sustainable water reuse management in the long term. However, more detailed field trials and investigations are still needed to effectively understand, predict and manage the impact of selected recycled water for new end use alternatives. Copyright © 2012 Elsevier B.V. All rights reserved.

EAO consensus conference: economic evaluation of implant-supported prostheses.

PubMed

Beikler, Thomas; Flemmig, Thomas F

2015-09-01

There are various alternatives for the management of oral conditions that may lead to or already have lead to partial or full edentulism. Economic evaluations measure the efficiency of alternative healthcare interventions and provide useful information for decision-making and the allocation of scarce resources. The current English literature dealing with "cost-effectiveness" of dental implant therapy versus different alternative treatment modalities, that is, complete and fixed partial dentures, root canal, and periodontal treatment, has been included in this narrative review. Due to the high heterogeneity within the literature, a meta-analysis could not be conducted. The available evidence from economic evaluations indicated that for the treatment of central incisors with irreversible pulpitis and coronal lesions, root canal treatments were most cost-effective initial treatment options. When initial root canal treatments failed, orthograde retreatments were most cost-effective. When root canal retreatments failed, extractions and replacement with single implant-supported crowns were more cost-effective compared to fixed or removable partial dentures. In the treatment of periodontitis in molars with Class I furcation invasion, non-surgical periodontal therapy was more effective and costed less than implant-supported single crowns. For the replacement of single missing teeth, two evaluations indicated that implant-supported single crowns provided better outcomes in terms of greater quality-adjusted tooth years or survival rates at lower costs compared to fixed partial prostheses. Another economic evaluation found that implant-supported crowns costed more, but provided greater survival rates compared to fixed partial dentures. For the restoration of edentulous mandibles, two evaluations indicated that overdentures retained by two or four implants improved oral health-related quality of life outcomes, but costed more than complete dentures. To better assess the efficiency of implant-supported prostheses in various clinical conditions, more economic evaluations are needed that follow well-established methodologies in health economics. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Role of a Standardized Prism Under Cover Test in the Assessment of Dissociated Vertical Deviation.

PubMed

Klaehn, Lindsay D; Hatt, Sarah R; Leske, David A; Holmes, Jonathan M

2018-03-01

Dissociated vertical deviation (DVD) is commonly measured using a prism and alternate cover test (PACT), but some providers use a prism under cover test (PUCT). The aim of this study was to compare a standardized PUCT measurement with a PACT measurement, for assessing the magnitude of DVD. Thirty-six patients with a clinical diagnosis of DVD underwent measurement of the angle of deviation with the PACT, fixing with the habitually fixing eye, and with PUCT, fixing both right and left eyes. The PUCT was standardized, using a 10-second cover for each prism magnitude, until the deviation was neutralized. The magnitude of hyperdeviation by PACT and PUCT was compared for the non-fixing eye, using paired non-parametric tests. The frequency of discrepancies more than 4 prism diopters (PD) between PACT and PUCT was calculated. The magnitude of hyperdeviation was greater when measured with PUCT (range 8PD hypodeviation to 20PD hyperdeviation) vs. PACT (18PD hypodeviation to 25PD hyperdeviation) with a median difference of 4.5PD (range -5PD to 21PD); P < 0.0001. Eighteen (50%) of 36 measurements elicited >4PD hyperdeviation (or >4PD less hypodeviation) by PUCT than by PACT. A standardized 10-second PUCT yields greater values than a prism and alternate cover test in the majority of patients with DVD, providing better quantification of the severity of DVD, which may be important for management decisions.

Simple coil-powering techniques for generating 10KA/m alternating magnetic field at multiple frequencies using 0.5KW RF power for magnetic nanoparticle hyperthermia

NASA Astrophysics Data System (ADS)

Piao, Daqing; Sun, Tengfei; Ranjan, Ashish

2017-02-01

Alternating magnetic field (AMF) configurable at a range of frequencies is a critical need for optimization of magnetic nanoparticle based hyperthermia, and for their application in targeted drug delivery. Currently, most commercial AMF devices including induction heaters operate at one factory-fixed frequency, thereby limiting customized frequency configuration required for triggered drug release at mild hyperthermia (40-42°C) and ablations (>55°C). Most AMF devices run as an inductor-capacitor resonance network that could allow AMF frequencies to be changed by changing the capacitor bank or the coil looped with it. When developing AMF inhouse, the most expensive component is usually the RF power amplifier, and arguably the most critical step of building a strong AMF field is impedance-matched coupling of RF power to the coolant-cooled AMF coil. AMF devices running at 10KA/m strength are quite common, but generating AMF at that level of field strength using RF power less than 1KW has remained challenging. We practiced a few techniques for building 10KA/m AMFs at different frequencies, by utilizing a 0.5KW 80-800KHz RF power amplifier. Among the techniques indispensable to the functioning of these AMFs, a simple cost-effective technique was the tapping methods for discretely or continuously adjusting the position of an RF-input-tap on a single-layer or the outer-layer of a multi-layer AMF coil for maximum power coupling into the AMF coil. These in-house techniques when combined facilitated 10KA/m AMF at frequencies of 88.8 KHz and higher as allowed by the inventory of capacitors using 0.5KW RF power, for testing heating of 10-15nm size magnetic particles and on-going evaluation of drug-release by low-level temperature-sensitive liposomes loaded with 15nm magnetic nanoparticles.

75 FR 17899 - Availability of Seats for the Stellwagen Bank National Marine Sanctuary Advisory Council

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-08

... and Alternate two-year terms for (1) Research; (1) Conservation; (1) Whale Watching; (1) Fixed Gear... professional affiliations; philosophy regarding the protection and management of marine resources; and possibly...

Resilient Attachments as an Alternative to Conventional Cast Clasp Removable Partial Denture: 3-Year Follow-up.

PubMed

Schuh, Cristian; Adiel Skupien, Jovito; Mesko, Mauro Elias; Valentini, Fernanda; Pereira-Cenci, Tatiana; Boscato, Noéli

2014-12-01

The present clinical report describes the prosthodontic management for a patient with uncontrolled bleeding and diabetes mellitus treated with a maxillary complete denture and a mandibular partial fixed dental prosthesis designed to interface with a removable cast framework partial denture retained by 2 ERA attachments. This approach was undertaken to improve both retention and stability of the distal extension Kennedy Class I removable partial denture. The rehabilitation provided better anterior esthetics than if treated with a conventional clasp retained removable partial denture, by employing a simple, practical design and offering a significant biomechanical advantages, restoring both oral health and function. Thus, this treatment modality, involving an ERA system and transfixation in fixed crowns, is an effective treatment and can be indicated as a clinical alternative for edentulous and partially edentulous patients with systemic disorders or for patients in economic situations that might preclude implant-based rehabilitation.

Alignment Solution for CT Image Reconstruction using Fixed Point and Virtual Rotation Axis.

PubMed

Jun, Kyungtaek; Yoon, Seokhwan

2017-01-25

Since X-ray tomography is now widely adopted in many different areas, it becomes more crucial to find a robust routine of handling tomographic data to get better quality of reconstructions. Though there are several existing techniques, it seems helpful to have a more automated method to remove the possible errors that hinder clearer image reconstruction. Here, we proposed an alternative method and new algorithm using the sinogram and the fixed point. An advanced physical concept of Center of Attenuation (CA) was also introduced to figure out how this fixed point is applied to the reconstruction of image having errors we categorized in this article. Our technique showed a promising performance in restoring images having translation and vertical tilt errors.

Digital data acquisition for a CAD/CAM-fabricated titanium framework and zirconium oxide restorations for an implant-supported fixed complete dental prosthesis.

PubMed

Lin, Wei-Shao; Metz, Michael J; Pollini, Adrien; Ntounis, Athanasios; Morton, Dean

2014-12-01

This dental technique report describes a digital workflow with digital data acquisition at the implant level, computer-aided design and computer-aided manufacturing fabricated, tissue-colored, anodized titanium framework, individually luted zirconium oxide restorations, and autopolymerizing injection-molded acrylic resin to fabricate an implant-supported, metal-ceramic-resin fixed complete dental prosthesis in an edentulous mandible. The 1-step computer-aided design and computer-aided manufacturing fabrication of titanium framework and zirconium oxide restorations can provide a cost-effective alternative to the conventional metal-resin fixed complete dental prosthesis. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Zygomatic implant-retained fixed complete denture for an elderly patient.

PubMed

Baig, Mirza Rustum; Rajan, Gunaseelan; Yunus, Norsiah

2012-06-01

Dental rehabilitation of a completely edentulous geriatric patient has always been a challenge to the clinician, especially in treating those with higher expectations and demands. Treatment duration and the amount of residual alveolar bone available are often important considerations when planning for dental implant-based fixed treatment for these patients. With the introduction of zygomatic implants, a graftless alternative solution has emerged for deficient maxillary bone with provision for immediate loading. This article describes the treatment of a completely edentulous elderly patient using zygomatic implants in conjunction with conventional implants. The implants were immediately loaded using a definitive acrylic resin fixed denture reinforced with a cast metal framework, to provide function and aesthetics. © 2011 The Gerodontology Society and John Wiley & Sons A/S.

Video-microscopy for use in microsurgical aspects of complex hepatobiliary and pancreatic surgery: a preliminary report

PubMed Central

Nissen, Nicholas N; Menon, Vijay; Williams, James; Berci, George

2011-01-01

Background The use of loupe magnification during complex hepatobiliary and pancreatic (HBP) surgery has become routine. Unfortunately, loupe magnification has several disadvantages including limited magnification, a fixed field and non-variable magnification parameters. The aim of this report is to describe a simple system of video-microscopy for use in open surgery as an alternative to loupe magnification. Methods In video-microscopy, the operative field is displayed on a TV monitor using a high-definition (HD) camera with a special optic mounted on an adjustable mechanical arm. The set-up and application of this system are described and illustrated using examples drawn from pancreaticoduodenectomy, bile duct repair and liver transplantation. Results This system is easy to use and can provide variable magnification of ×4–12 at a camera distance of 25–35 cm from the operative field and a depth of field of 15 mm. This system allows the surgeon and assistant to work from a HD TV screen during critical phases of microsurgery. Conclusions The system described here provides better magnification than loupe lenses and thus may be beneficial during complex HPB procedures. Other benefits of this system include the fact that its use decreases neck strain and postural fatigue in the surgeon and it can be used as a tool for documentation and teaching. PMID:21929677

Dose Rationalization of Pembrolizumab and Nivolumab Using Pharmacokinetic Modeling and Simulation and Cost Analysis.

PubMed

Ogungbenro, Kayode; Patel, Alkesh; Duncombe, Robert; Nuttall, Richard; Clark, James; Lorigan, Paul

2018-04-01

Pembrolizumab and nivolumab are highly selective anti-programmed cell death 1 (PD-1) antibodies approved for the treatment of advanced malignancies. Variable exposure and significant wastage have been associated with body size dosing of monoclonal antibodies (mAbs). The following dosing strategies were evaluated using simulations: body weight, dose banding, fixed dose, and pharmacokinetic (PK)-based methods. The relative cost to body weight dosing for band, fixed 150 mg and 200 mg, and PK-derived strategies were -15%, -25%, + 7%, and -16% for pembrolizumab and -8%, -6%, and -10% for band, fixed, and PK-derived strategies for nivolumab, respectively. Relative to mg/kg doses, the median exposures were -1.0%, -4.6%, + 27.1%, and +3.0% for band, fixed 150 mg, fixed 200 mg, and PK-derived strategies, respectively, for pembrolizumab and -3.1%, + 1.9%, and +1.4% for band, fixed 240 mg, and PK-derived strategies, respectively, for nivolumab. Significant wastage can be reduced by alternative dosing strategies without compromising exposure and efficacy. © 2017 American Society for Clinical Pharmacology and Therapeutics.

Advection of nematic liquid crystals by chaotic flow

NASA Astrophysics Data System (ADS)

O'Náraigh, Lennon

2017-04-01

Consideration is given to the effects of inhomogeneous shear flow (both regular and chaotic) on nematic liquid crystals in a planar geometry. The Landau-de Gennes equation coupled to an externally prescribed flow field is the basis for the study: this is solved numerically in a periodic spatial domain. The focus is on a limiting case where the advection is passive, such that variations in the liquid-crystal properties do not feed back into the equation for the fluid velocity. The main tool for analyzing the results (both with and without flow) is the identification of the fixed points of the dynamical equations without flow, which are relevant (to varying degrees) when flow is introduced. The fixed points are classified as stable/unstable and further as either uniaxial or biaxial. Various models of passive shear flow are investigated. When tumbling is present, the flow is shown to have a strong effect on the liquid-crystal morphology; however, the main focus herein is on the case without tumbling. Accordingly, the main result of the work is that only the biaxial fixed point survives as a solution of the Q-tensor dynamics under the imposition of a general flow field. This is because the Q-tensor experiences not only transport due to advection but also co-rotation relative to the local vorticity field. A second result is that all families of fixed points survive for certain specific velocity fields, which we classify. We single out for close study those velocity fields for which the influence of co-rotation effectively vanishes along the Lagrangian trajectories of the imposed velocity field. In this scenario, the system exhibits coarsening arrest, whereby the liquid-crystal domains are "frozen in" to the flow structures, and the growth in their size is thus limited.

Sidewall containment of liquid metal with vertical alternating magnetic fields

DOEpatents

Lari, Robert J.; Praeg, Walter F.; Turner, Larry R.; Battles, James E.; Hull, John R.; Rote, Donald M.

1990-01-01

An apparatus for containing molten metal using a magnet producing vertical alternating magnetic field positioned adjacent the area in which the molten metal is to be confined. This invention can be adapted particularly to the casting of metal between counter-rotating rollers with the vertical alternating magnetic field used to confine the molten metal at the edges of the rollers. Alternately, the vertical alternating magnetic field can be used as a flow regulator in casting molten metal from an opening in a channel.

Subwavelength resolution from multilayered structure (Conference Presentation)

NASA Astrophysics Data System (ADS)

Cheng, Bo Han; Jen, Yi-Jun; Liu, Wei-Chih; Lin, Shan-wen; Lan, Yung-Chiang; Tsai, Din Ping

2016-10-01

Breaking optical diffraction limit is one of the most important issues needed to be overcome for the demand of high-density optoelectronic components. Here, a multilayered structure which consists of alternating semiconductor and dielectric layers for breaking optical diffraction limitation at THz frequency region are proposed and analyzed. We numerically demonstrate that such multilayered structure not only can act as a hyperbolic metamaterial but also a birefringence material via the control of the external temperature (or magnetic field). A practical approach is provided to control all the diffraction signals toward a specific direction by using transfer matrix method and effective medium theory. Numerical calculations and computer simulation (based on finite element method, FEM) are carried out, which agree well with each other. The temperature (or magnetic field) parameter can be tuned to create an effective material with nearly flat isofrequency feature to transfer (project) all the k-space signals excited from the object to be resolved to the image plane. Furthermore, this multilayered structure can resolve subwavelength structures at various incident THz light sources simultaneously. In addition, the resolution power for a fixed operating frequency also can be tuned by only changing the magnitude of external magnetic field. Such a device provides a practical route for multi-functional material, photolithography and real-time super-resolution image.

Comparative field study: impact of laboratory assay variability on the assessment of recombinant factor IX Fc fusion protein (rFIXFc) activity.

PubMed

Sommer, Jurg M; Buyue, Yang; Bardan, Sara; Peters, Robert T; Jiang, Haiyan; Kamphaus, George D; Gray, Elaine; Pierce, Glenn F

2014-11-01

Due to variability in the one-stage clotting assay, the performance of new factor IX (FIX) products should be assessed in this assay. The objective of this field study was to evaluate the accuracy of measuring recombinant FIX Fc fusion protein (rFIXFc) activity in clinical haemostasis laboratories using the one-stage clotting assay. Human haemophilic donor plasma was spiked with rFIXFc or BeneFIX® at 0.80, 0.20, or 0.05 IU/ml based on label potency. Laboratories tested blinded samples using their routine one-stage assay and in-house FIX plasma standard. The mean spike recoveries for BeneFIX (n=30 laboratories) were 121 %, 144 %, and 168 % of expected at nominal 0.80, 0.20, and 0.05 IU/ml concentrations, respectively. Corresponding rFIXFc spike recoveries were 88 %, 107 %, and 132 % of expected, respectively. All BeneFIX concentrations were consistently overestimated by most laboratories. rFIXFc activity was reagent-dependent; ellagic acid and silica gave higher values than kaolin, which underestimated rFIXFc. BeneFIX demonstrated significantly reduced chromogenic assay activity relative to one-stage assay results and nominal activity, while rFIXFc activity was close to nominal activity at three concentrations with better dilution linearity than the typical one-stage assay. In conclusion, laboratory- and reagent-specific assay variabilities were revealed, with progressively higher variability at lower FIX concentrations. Non-parallelism against the FIX plasma standard was observed in all one-stage assays with rFIXFc and BeneFIX, leading to significant overestimation of FIX activity at lower levels and generally high inter-laboratory variability. Compared to the accuracy currently achieved in clinical laboratories when measuring other rFIX products, most laboratories measured rFIXFc activity with acceptable accuracy and reliability using routine one-stage assay methods and commercially available plasma standards.

A translating stage system for µ-PIV measurements surrounding the tip of a migrating semi-infinite bubble.

PubMed

Smith, B J; Yamaguchi, E; Gaver, D P

2010-01-01

We have designed, fabricated and evaluated a novel translating stage system (TSS) that augments a conventional micro particle image velocimetry (µ-PIV) system. The TSS has been used to enhance the ability to measure flow fields surrounding the tip of a migrating semi-infinite bubble in a glass capillary tube under both steady and pulsatile reopening conditions. With conventional µ-PIV systems, observations near the bubble tip are challenging because the forward progress of the bubble rapidly sweeps the air-liquid interface across the microscopic field of view. The translating stage mechanically cancels the mean bubble tip velocity, keeping the interface within the microscope field of view and providing a tenfold increase in data collection efficiency compared to fixed-stage techniques. This dramatic improvement allows nearly continuous observation of the flow field over long propagation distances. A large (136-frame) ensemble-averaged velocity field recorded with the TSS near the tip of a steadily migrating bubble is shown to compare well with fixed-stage results under identical flow conditions. Use of the TSS allows the ensemble-averaged measurement of pulsatile bubble propagation flow fields, which would be practically impossible using conventional fixed-stage techniques. We demonstrate our ability to analyze these time-dependent two-phase flows using the ensemble-averaged flow field at four points in the oscillatory cycle.

Synergistic dye adsorption by biochar from co-pyrolysis of spent mushroom substrate and Saccharina japonica.

PubMed

Sewu, Divine Damertey; Boakye, Patrick; Jung, Hwansoo; Woo, Seung Han

2017-11-01

The potential of activating terrestrial biomass (spent mushroom substrate, SMS) with ash-laden marine biomass [kelp seaweed, KE] via co-pyrolysis in the field of adsorption was first investigated. KE biochar (KBC), SMS biochar (SMSBC), biochar (SK10BC) from 10%-KE added SMS, and biochar (ESBC) from KE-extract added SMS were used for the adsorption of cationic dye crystal violet (CV). ESBC had highest fixed carbon content (70.60%) and biochar yield (31.6%). SK10BC exhibited high ash content, abundant functional groups, coarser surface morphology and Langmuir maximum adsorptive capacity (610.1mg/g), which is 2.2 times higher than that of SMSBC (282.9mg/g). Biochar activated by a small amount of high ash-containing biomass such as seaweed via co-pyrolysis can serve as viable alternative adsorbent for cationic dye removal. Copyright © 2017 Elsevier Ltd. All rights reserved.

Broadband wireless, integrated services, and their application to intelligent transportation systems

DOT National Transportation Integrated Search

2000-06-01

This paper introduces some of the newer broadband wireless communications alternatives and describes how they could be used to provide high-speed connections between fixed, transportable, and mobile facilities. We also describe the new integrated ser...

Electromagnetic Fields and Public Health: Mobile Phones

MedlinePlus

... Ebola virus disease » Home / News / Fact sheets / Detail Electromagnetic fields and public health: mobile phones 8 October ... fixed antennas called base stations. Radiofrequency waves are electromagnetic fields, and unlike ionizing radiation such as X- ...

Angulated Implants for Fabrication of Implant Supported Fixed Partial Denture in the Maxilla

PubMed Central

Egbert, Nicholas; Ahuja, Swati; Selecman, Audrey; Wicks, Russell

2017-01-01

Until recently, angled abutments have been the only solution to correcting the trajectory of the emergence profile of labially inclined implants in the maxilla. However, the clinical implications of angled abutments reveal several shortcomings. Newly designed angulated implants with a 12-degree restorative platform angulation are an alternative to angled abutments. The purpose of this article was to report a case utilizing new angulated implants (Co-axis, Keystone dental, Burlington, MA, USA) in the premaxilla thereby facilitating fabrication of a multi-unit implant retained fixed dental prosthesis. PMID:29201975

[Fixed-dose combination fluticasone propionate/formoterol for the treatment of asthma: a review of its pharmacology, efficacy and tolerability].

PubMed

Quintano Jiménez, J A; Ginel Mendoza, L; Entrenas Costa, L M; Polo García, J

2016-02-01

The fixed-dose combination fluticasone propionate/formoterol (FPF) is a novel combination of a widely known and used inhaled glucocorticoid (IGC) and a long-acting β2-adrenergic agonist (LABA), available for the first time in a single device. This fixed-dose combination of FPF has a demonstrated efficacy and safety profile in clinical trials compared with its individual components and other fixed-dose combinations of IGC/LABA and is indicated for the treatment of persistent asthma in adults and adolescents. FPF is available in a wide range of doses that can adequately cover the therapeutic steps recommended by treatment guidelines, constituting a fixed-dose combination of GCI/LABA that is effective, rapid, well tolerated and with a reasonable acquisition cost. Various assessment agencies of the Spanish Autonomous Communities consider this combination to be an appropriate alternative therapy for asthma in the primary care setting. Copyright © 2016 Elsevier España, S.L.U. y Sociedad Española de Medicina Rural y Generalista (SEMERGEN). All rights reserved.

VMAT vs. 7-Field-IMRT: Assessing the Dosimetric Parameters of Prostate Cancer Treatment with a 292-Patient Sample

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

Kopp, Robert W.; Duff, Michael, E-mail: mduff@cancercarewny.com; Catalfamo, Frank

2011-01-01

We compared normal tissue radiation dose for the treatment of prostate cancer using 2 different radiation therapy delivery methods: volumetric modulated arc therapy (VMAT) vs. fixed-field intensity-modulated radiation therapy (IMRT). Radiotherapy plans for 292 prostate cancer patients treated with VMAT to a total dose of 7740 cGy were analyzed retrospectively. Fixed-angle, 7-field IMRT plans were created using the same computed tomography datasets and contours. Radiation doses to the planning target volume (PTV) and organs at risk (bladder, rectum, penile bulb, and femoral heads) were measured, means were calculated for both treatment methods, and dose-volume comparisons were made with 2-tailed, pairedmore » t-tests. The mean dose to the bladder was lower with VMAT at all measured volumes: 5, 10, 15, 25, 35, and 50% (p < 0.05). The mean doses to 5 and 10% of the rectum, the high-dose regions, were lower with VMAT (p < 0.05). The mean dose to 15% of the rectal volume was not significantly different (p = 0.95). VMAT exposed larger rectal volumes (25, 35, and 50%) to more radiation than fixed-field IMRT (p < 0.05). Average mean dose to the penile bulb (p < 0.05) and mean dose to 10% of the femoral heads (p < 0.05) were lower with VMAT. VMAT therapy for prostate cancer has dosimetric advantages for critical structures, notably for high-dose regions compared with fixed-field IMRT, without compromising PTV coverage. This may translate into reduced acute and chronic toxicity.« less

MHD Turbulence Sheared in Fixed and Rotating Frames

NASA Technical Reports Server (NTRS)

Kassinos, S. C.; Knaepen, B.; Wray, A.

2004-01-01

We consider homogeneous turbulence in a conducting fluid that is exposed to a uniform external magnetic field while being sheared in fixed and rotating frames. We take both the frame-rotation axis and the applied magnetic field to be aligned in the direction normal to the plane of the mean shear. Here a systematic parametric study is carried out in a series of Direct Numerical Simulations (DNS) in order to clarify the main effects determining the structural anisotropy and stability of the flow.

Decay of superconducting correlations for gauged electrons in dimensions D ≤ 4

NASA Astrophysics Data System (ADS)

Tada, Yasuhiro; Koma, Tohru

2018-03-01

We study lattice superconductors coupled to gauge fields, such as an attractive Hubbard model in electromagnetic fields, with a standard gauge fixing. We prove upper bounds for a two-point Cooper pair correlation at finite temperatures in spatial dimensions D ≤ 4. The upper bounds decay exponentially in three dimensions and by power law in four dimensions. These imply the absence of the superconducting long-range order for the Cooper pair amplitude as a consequence of fluctuations of the gauge fields. Since our results hold for the gauge fixing Hamiltonian, they cannot be obtained as a corollary of Elitzur's theorem.

Weather resistance of CaSO4 ṡ 1/2H2O-based sand-fixation material

NASA Astrophysics Data System (ADS)

Liu, Xin; Tie, Shengnian

2017-07-01

Searching for an economical and effective sand-fixing material and technology is of great importance in Northwest China. This paper described the use of a semihydrated gypsum-(CaSO4 ṡ 1/2H2O-)based composite as a sand-fixing material. Its morphology and composition were characterized by SEM, and its water resistance, freezing-thawing resistance and wind erosion resistance were tested in the field. The results indicated that semihydrated gypsum-(CaSO4 ṡ 1/2H2O-)based sand-fixing composite has good water resistance and water-holding capacity. Its strength is maintained at 1.42 MPa after 50 freezing and thawing cycles, and its wind erosion increases with increasing wind speed and slope. Its compressive strength starts to decrease after nine months of field tests with no change in appearance, but it still satisfies the requirements of fixation technology. This sand-fixing material should have wide application owing to its good weather resistance.

Sidewall containment of liquid metal with vertical alternating magnetic fields

DOEpatents

Lari, R.J.; Praeg, W.F.; Turner, L.R.; Battles, J.E.; Hull, J.R.; Rote, D.M.

1990-12-04

An apparatus is disclosed for containing molten metal using a magnet producing vertical alternating magnetic field positioned adjacent the area in which the molten metal is to be confined. This invention can be adapted particularly to the casting of metal between counter-rotating rollers with the vertical alternating magnetic field used to confine the molten metal at the edges of the rollers. Alternately, the vertical alternating magnetic field can be used as a flow regulator in casting molten metal from an opening in a channel. 9 figs.

Sidewall containment of liquid metal with vertical alternating magnetic fields

DOEpatents

Lari, R.J.; Praeg, W.F.; Turner, L.R.; Battles, J.E.; Hull, J.R.; Rote, D.M.

1988-06-17

An apparatus for containing molten metal using a magnet producing vertical alternating magnetic field positioned adjacent to the area in which the molten metal is to be confined. This invention can be adapted particularly to the casting of metal between counter-rotating rollers with the vertical alternating magnetic field used to confine the molten metal at the edges of the rollers. Alternately, the vertical alternating magnetic field can be used as a flow regulator in casting molten metal from an opening in a channel. 8 figs.

Dynamic Balancing of Isoprene Carbon Sources Reflects Photosynthetic and Photorespiratory Responses to Temperature Stress1[W][OPEN

PubMed Central

Chambers, Jeffrey; Alves, Eliane G.; Teixeira, Andrea; Garcia, Sabrina; Holm, Jennifer; Higuchi, Niro; Manzi, Antonio; Abrell, Leif; Fuentes, Jose D.; Nielsen, Lars K.; Torn, Margaret S.; Vickers, Claudia E.

2014-01-01

The volatile gas isoprene is emitted in teragrams per annum quantities from the terrestrial biosphere and exerts a large effect on atmospheric chemistry. Isoprene is made primarily from recently fixed photosynthate; however, alternate carbon sources play an important role, particularly when photosynthate is limiting. We examined the relative contribution of these alternate carbon sources under changes in light and temperature, the two environmental conditions that have the strongest influence over isoprene emission. Using a novel real-time analytical approach that allowed us to examine dynamic changes in carbon sources, we observed that relative contributions do not change as a function of light intensity. We found that the classical uncoupling of isoprene emission from net photosynthesis at elevated leaf temperatures is associated with an increased contribution of alternate carbon. We also observed a rapid compensatory response where alternate carbon sources compensated for transient decreases in recently fixed carbon during thermal ramping, thereby maintaining overall increases in isoprene production rates at high temperatures. Photorespiration is known to contribute to the decline in net photosynthesis at high leaf temperatures. A reduction in the temperature at which the contribution of alternate carbon sources increased was observed under photorespiratory conditions, while photosynthetic conditions increased this temperature. Feeding [2-13C]glycine (a photorespiratory intermediate) stimulated emissions of [13C1–5]isoprene and 13CO2, supporting the possibility that photorespiration can provide an alternate source of carbon for isoprene synthesis. Our observations have important implications for establishing improved mechanistic predictions of isoprene emissions and primary carbon metabolism, particularly under the predicted increases in future global temperatures. PMID:25318937

Dynamic balancing of isoprene carbon sources reflects photosynthetic and photorespiratory responses to temperature stress.

PubMed

Jardine, Kolby; Chambers, Jeffrey; Alves, Eliane G; Teixeira, Andrea; Garcia, Sabrina; Holm, Jennifer; Higuchi, Niro; Manzi, Antonio; Abrell, Leif; Fuentes, Jose D; Nielsen, Lars K; Torn, Margaret S; Vickers, Claudia E

2014-12-01

The volatile gas isoprene is emitted in teragrams per annum quantities from the terrestrial biosphere and exerts a large effect on atmospheric chemistry. Isoprene is made primarily from recently fixed photosynthate; however, alternate carbon sources play an important role, particularly when photosynthate is limiting. We examined the relative contribution of these alternate carbon sources under changes in light and temperature, the two environmental conditions that have the strongest influence over isoprene emission. Using a novel real-time analytical approach that allowed us to examine dynamic changes in carbon sources, we observed that relative contributions do not change as a function of light intensity. We found that the classical uncoupling of isoprene emission from net photosynthesis at elevated leaf temperatures is associated with an increased contribution of alternate carbon. We also observed a rapid compensatory response where alternate carbon sources compensated for transient decreases in recently fixed carbon during thermal ramping, thereby maintaining overall increases in isoprene production rates at high temperatures. Photorespiration is known to contribute to the decline in net photosynthesis at high leaf temperatures. A reduction in the temperature at which the contribution of alternate carbon sources increased was observed under photorespiratory conditions, while photosynthetic conditions increased this temperature. Feeding [2-(13)C]glycine (a photorespiratory intermediate) stimulated emissions of [(13)C1-5]isoprene and (13)CO2, supporting the possibility that photorespiration can provide an alternate source of carbon for isoprene synthesis. Our observations have important implications for establishing improved mechanistic predictions of isoprene emissions and primary carbon metabolism, particularly under the predicted increases in future global temperatures. © 2014 American Society of Plant Biologists. All Rights Reserved.

Understanding your capital options.

PubMed

Payne, Christopher T

2012-05-01

When planning capital expenditures, hospitals and health systems should understand the following financing considerations: Traditional fixed-rate tax-exempt bonds; Variable-rate financing alternatives; Basel III Accord requirements; Direct tax-exempt bank loans; Total return swaps Taxable financings; Interest-rate swaps and collateral requirements

Evaluating the use of transfers for improving demand responsive systems adopting zoning strategies.

DOT National Transportation Integrated Search

2011-08-01

Due to widely dispersed population density over large and sparsely suburban/rural areas, : conventional fixed route transit services hardly satisfy the travel needs of their residents. As an : alternative, demand responsive transit (DRT) systems have...

The current use of patient-centered/reported outcomes in implant dentistry: a systematic review.

PubMed

De Bruyn, Hugo; Raes, Stefanie; Matthys, Carine; Cosyn, Jan

2015-09-01

To provide an update on the use of Patient-Reported Outcome Measures (PROMs) in the field of implant dentistry (1); to compare PROMs for prostheses supported by one or more implants to alternative treatment options or a healthy dentition (2). The dental literature was searched on PubMed until December 31, 2014, using a general search algorithm. An overall quantitative analysis was performed, and a qualitative appraisal was made on the output of the last 6 years. Per type of edentulism and prosthetic treatment, the general search algorithm was refined in order to select controlled studies comparing PROMs for prostheses supported by one or more implants to alternative treatment options or a healthy dentition. With nearly half of the output (300 of 635) published in the last 6 years, there is a growing interest in PROMs by the scientific community. When scrutinizing the 300 most recent publications, only 84 controlled studies could be identified among which 38 RCTs and 31 cohort studies. An "ad hoc" approach is commonly employed using non-standardized questions and different scoring methods, which may compromise validity and reliability. Overall, 39 eligible papers related to fully edentulous patients treated with an implant overdenture (IOD) and 9 to fully edentulous patients treated with a fixed implant prosthesis (FIP). There is plenty of evidence from well-controlled studies showing that fully edentulous patients in the mandible experience higher satisfaction with an IOD when compared to a conventional denture (CD). This may not hold true for fully edentulous patients in the maxilla. In general, fully edentulous patients seem to opt for a fixed or removable rehabilitation on implants for specific reasons. Data pertaining to partially edentulous patients were limited (FIP: n = 6; single implants: n = 16). In these patients, the timing of implant placement does not seem to affect patient satisfaction. Patients seem to prefer straightforward implant surgery over complex surgery that includes bone grafting. There is an urgent need for standardized reporting of PROMs in the field of implant dentistry. Fully edentulous patients in the mandible experience higher satisfaction with an IOD when compared to a CD. All other types of prostheses have been underexposed to research. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Choice in situations of time-based diminishing returns: immediate versus delayed consequences of action.

PubMed Central

Hackenberg, T D; Hineline, P N

1992-01-01

Pigeons chose between two schedules of food presentation, a fixed-interval schedule and a progressive-interval schedule that began at 0 s and increased by 20 s with each food delivery provided by that schedule. Choosing one schedule disabled the alternate schedule and stimuli until the requirements of the chosen schedule were satisfied, at which point both schedules were again made available. Fixed-interval duration remained constant within individual sessions but varied across conditions. Under reset conditions, completing the fixed-interval schedule not only produced food but also reset the progressive interval to its minimum. Blocks of sessions under the reset procedure were interspersed with sessions under a no-reset procedure, in which the progressive schedule value increased independent of fixed-interval choices. Median points of switching from the progressive to the fixed schedule varied systematically with fixed-interval value, and were consistently lower during reset than during no-reset conditions. Under the latter, each subject's choices of the progressive-interval schedule persisted beyond the point at which its requirements equaled those of the fixed-interval schedule at all but the highest fixed-interval value. Under the reset procedure, switching occurred at or prior to that equality point. These results qualitatively confirm molar analyses of schedule preference and some versions of optimality theory, but they are more adequately characterized by a model of schedule preference based on the cumulated values of multiple reinforcers, weighted in inverse proportion to the delay between the choice and each successive reinforcer. PMID:1548449

Clinical relevance of diagnosing COPD by fixed ratio or lower limit of normal: a systematic review.

PubMed

van Dijk, Wouter D; Gupta, Nisha; Tan, Wan C; Bourbeau, Jean

2014-02-01

Different spirometric criteria in diagnosing COPD have been advocated by different groups, debilitating adequate diagnosis and treatment of COPD. We reviewed the clinical relevance of fixed ratio and lower limit of normal (LLN) in diagnosing COPD and explored if modifying factors may affect their clinical relevance. Two reviewers independently searched PubMed and Embase for papers that compared both criteria on any clinically relevant outcome, published before June 1st, 2012, without any language restriction. Two reviewers independently extracted the study characteristics, including study design, population characteristics and diagnostic criteria used, and summarized the results of clinical relevance. Study quality was assessed by scoring forms for bias and level of evidence. Of 394 studies retrieved, 11 studies were included, with a median of 1,258 participants. Although both criteria appeared related with various clinically relevant outcomes, we were unable to prefer one criterion over the other, with various performances of the criteria for different outcomes. Should the criteria disagree on diagnosis, an alternative diagnosis should be suspected, in particular in those (elderly) with less severe airflow limitation for whom the LLN appears a better criterion. The fixed ratio appears to perform better in subjects with more severe airflow limitation. In diagnosing COPD, severity of airflow limitation appears an important factor for choosing whether the fixed ratio or LLN. Disagreement between the criteria is suggestive for an alternative diagnosis. Future studies on clinical relevance should further reveal the criterion of choice, in order to improve adequate diagnosis and consequent treatments.

Clinical acceptability of metal-ceramic fixed partial dental prosthesis fabricated with direct metal laser sintering technique-5 year follow-up.

PubMed

Prabhu, Radhakrishnan; Prabhu, Geetha; Baskaran, Eswaran; Arumugam, Eswaran M

2016-01-01

In recent years, direct metal laser sintered (DMLS) metal-ceramic-based fixed partial denture prostheses have been used as an alternative to conventional metal-ceramic fixed partial denture prostheses. However, clinical studies for evaluating their long-term clinical survivability and acceptability are limited. The aim of this study was to assess the efficacy of metal-ceramic fixed dental prosthesis fabricated with DMLS technique, and its clinical acceptance on long-term clinical use. The study group consisted of 45 patients who were restored with posterior three-unit fixed partial denture prosthesis made using direct laser sintered metal-ceramic restorations. Patient recall and clinical examination of the restorations were done after 6months and every 12 months thereafter for the period of 60 months. Clinical examination for evaluation of longevity of restorations was done using modified Ryge criteria which included chipping of the veneered ceramic, connector failure occurring in the fixed partial denture prosthesis, discoloration at the marginal areas of the veneered ceramic, and marginal adaptation of the metal and ceramic of the fixed denture prosthesis. Periapical status was assessed using periodical radiographs during the study period. Survival analysis was made using the Kaplan-Meier method. None of the patients had failure of the connector of the fixed partial denture prostheses during the study period. Two exhibited biological changes which included periapical changes and proximal caries adjacent to the abutments. DMLS metal-ceramic fixed partial denture prosthesis had a survival rate of 95.5% and yielded promising results during the 5-year clinical study.

Next-gen tissue: preservation of molecular and morphological fidelity in prostate tissue.

PubMed

Gillard, Marc; Tom, Westin R; Antic, Tatjana; Paner, Gladell P; Lingen, Mark W; VanderWeele, David J

2015-01-01

Personalization of cancer therapy requires molecular evaluation of tumor tissue. Traditional tissue preservation involves formalin fixation, which degrades the quality of nucleic acids. Strategies to bank frozen prostate tissue can interfere with diagnostic studies. PAXgene is an alternative fixative that preserves protein and nucleic acid quality. Portions of prostates obtained from autopsy specimens were fixed in either 10% buffered formalin or PAXgene, and processed and embedded in paraffin. Additional sections were immediately embedded in OCT and frozen. DNA and RNA were extracted from the formalin-fixed, PAXgene-fixed, or frozen tissue. Quantitative PCR was used to compare the quality of DNA and RNA obtained from all three tissue types. In addition, 5 μm sections were cut from specimens devoid of cancer and from prostate cancer specimens obtained at prostatectomy and fixed in PAXgene. They were either stained with hematoxylin and eosin or interrogated with antibodies for p63, PSA and p504. Comparable tissue morphology was observed in both the formalin and PAXgene-fixed specimens. Similarly, immunohistochemical expression of the P63, PSA and P504 proteins was comparable between formalin and PAXgene fixation techniques. DNA from the PAXgene-fixed tissue was of similar quality to that from frozen tissue. RNA was also amplified with up to 8-fold greater efficiency in the PAXgene fixed tissue compared to the formalin-fixed tissue. Prostate specimens fixed with PAXgene have preserved histologic morphology, stain appropriately, and have preserved quality of nucleic acids. PAXgene fixation facilitates the use of prostatectomy tissue for molecular biology techniques such as next-generation sequencing.

Buffer Gas Experiments in Mercury (Hg+) Ion Clock

NASA Technical Reports Server (NTRS)

Chung, Sang K.; Prestage, John D.; Tjoelker, Robert L.; Maleki, Lute

2004-01-01

We describe the results of the frequency shifts measured from various buffer gases that might be used as a buffer gas to increase the loading efficiency and cooling of ions trapped in a small mercury ion clock. The small mass, volume and power requirement of space clock precludes the use of turbo pumps. Hence, a hermetically sealed vacuum system, incorporating a suitable getter material with a fixed amount of inert buffer gas may be a practical alternative to the groundbased system. The collision shifts of 40,507,347.996xx Hz clock transition for helium, neon and argon buffer gases were measured in the ambient earth magnetic field. In addition to the above non-getterable inert gases we also measured the frequency shifts due to getterable, molecular hydrogen and nitrogen gases which may be used as buffer gases when incorporated with a miniature ion pump. We also examined the frequency shift due to the low methane gas partial pressure in a fixed higher pressure neon buffer gas environment. Methane gas interacted with mercury ions in a peculiar way as to preserve the ion number but to relax the population difference in the two hyperfine clock states and thereby reducing the clock resonance signal. The same population relaxation was also observed for other molecular buffer gases (N H,) but at much reduced rate.

Extended Range Aerial Delivery Using an Unpowered Autonomous Tailless UAV

NASA Astrophysics Data System (ADS)

Kraft, Tyler E.

An alternative approach for precision aerial delivery utilizing a flying wing for controllable forward glide is presented. Although effective, current delivery methods either display a lack of control, or require close standoff distances, potentially endangering aircraft personnel as well as bystanders. Hardware-in-the-loop simulations provide an efficient method for evaluating various wing designs and actuation configurations. Four control surface configurations are presented and evaluated, encompassing traditional aircraft and ram-air parafoil control approaches. Fixed-wing and multirotor unmanned aircraft-based flight tests were conducted to evaluate the controllability and handling performance of the various configurations of both a fixed wing model and a model with collapsing wings. A manufacturing process was developed to allow repeatable results in the field using cheap, mostly disposable materials. A powered flying wing model was used to maximize data collection in later stages of software development. Data collected during flight tests was used to create a model of the system and develop a Nonlinear Dynamic Inversion controller for autonomous flight. The NDI controller was able to provide stable flight in pitch, but will need more development to control yaw, instead an intentional bias was built in to show proof of concept for direct yaw control. The results demonstrate the feasibility of the flying wing-based aerial delivery; however, significant challenges remain regarding the stability and scalability of the system.

Apparatus and Methods for Mitigating Electromagnetic Emissions

NASA Technical Reports Server (NTRS)

Geng, Steven M. (Inventor); Niedra, Janis M. (Inventor)

2013-01-01

Apparatus, methods, and other embodiments associated with mitigation of magnetic fields are described herein. In an embodiment, a method for mitigating an electromagnetic field includes positioning a mitigating coil around a linear alternator of linear motor so that the mitigating coil is coaxially located with an alternator coil; arranging the mitigating coil to generate a field to mitigate an electromagnetic field generated by the alternator coil; and passing an induced current from the alternator coil through the mitigating coil.

Apparatus and Methods for Mitigating Electromagnetic Emissions

NASA Technical Reports Server (NTRS)

Geng, Steven M. (Inventor); Niedra, Janis M. (Inventor)

2016-01-01

Apparatus, methods, and other embodiments associated with mitigation of magnetic fields are described herein. In an embodiment, a method for mitigating an electromagnetic field includes positioning a mitigating coil around a linear alternator of linear motor so that the mitigating coil is coaxially located with an alternator coil; arranging the mitigating coil to generate a field to mitigate an electromagnetic field generated by the alternator coil; and passing an induced current from the alternator coil through the mitigating coil.

Insights into the history of the legume-betaproteobacterial symbiosis.

PubMed

Angus, Annette A; Hirsch, Ann M

2010-01-01

The interaction between legumes and rhizobia has been well studied in the context of a mutualistic, nitrogen-fixing symbiosis. The fitness of legumes, including important agricultural crops, is enhanced by the plants' ability to develop symbiotic associations with certain soil bacteria that fix atmospheric nitrogen into a utilizable form, namely, ammonia, via a chemical reaction that only bacteria and archaea can perform. Of the bacteria, members of the alpha subclass of the protebacteria are the best-known nitrogen-fixing symbionts of legumes. Recently, members of the beta subclass of the proteobacteria that induce nitrogen-fixing nodules on legume roots in a species-specific manner have been identified. In this issue, Bontemps et al. reveal that not only are these newly identified rhizobia novel in shifting the paradigm of our understanding of legume symbiosis, but also, based on symbiotic gene phylogenies, have a history that is both ancient and stable. Expanding our understanding of novel plant growth promoting rhizobia will be a valuable resource for incorporating alternative strategies of nitrogen fixation for enhancing plant growth.

Federal funding of rail rehabilitation : a review of alternative approaches

DOT National Transportation Integrated Search

1975-09-01

This study explores the proposed mechanisms for injecting federal funds into the rehabilitation of the fixed plant of U.S. railroads--that is, the roadbed, ballast, ties, signaling systems, yards and terminals that make up the physical rail system. T...

In-Vivo Techniques for Measuring Electrical Properties of Tissues.

DTIC Science & Technology

1980-09-01

probe Electromagnetic energy Dielectric properties Monopole antenna In-situ tissues , Antemortem/Pos tmortem studies Renal blood flow 10 ABSTRACT... mice or rats, which were positioned beneath a fixed measurement probe. Several alternative methods involving the use of semi-rigid or flexible coaxial

MERCURIC CHLORIDE CAPTURE BY ALKALINE SORBENTS

EPA Science Inventory

The paper gives results of bench-scale mechanistic studies of mercury/sorbent reactions that showed that mercuric chloride (HgC12) is readily adsorbed by alkaline sorbents, which may offers a less expensive alternative to the use of activated carbons. A laboratory-scale, fixed-b...

On the Control of the Fixed Charge Densities in Al2O3-Based Silicon Surface Passivation Schemes.

PubMed

Simon, Daniel K; Jordan, Paul M; Mikolajick, Thomas; Dirnstorfer, Ingo

2015-12-30

A controlled field-effect passivation by a well-defined density of fixed charges is crucial for modern solar cell surface passivation schemes. Al2O3 nanolayers grown by atomic layer deposition contain negative fixed charges. Electrical measurements on slant-etched layers reveal that these charges are located within a 1 nm distance to the interface with the Si substrate. When inserting additional interface layers, the fixed charge density can be continuously adjusted from 3.5 × 10(12) cm(-2) (negative polarity) to 0.0 and up to 4.0 × 10(12) cm(-2) (positive polarity). A HfO2 interface layer of one or more monolayers reduces the negative fixed charges in Al2O3 to zero. The role of HfO2 is described as an inert spacer controlling the distance between Al2O3 and the Si substrate. It is suggested that this spacer alters the nonstoichiometric initial Al2O3 growth regime, which is responsible for the charge formation. On the basis of this charge-free HfO2/Al2O3 stack, negative or positive fixed charges can be formed by introducing additional thin Al2O3 or SiO2 layers between the Si substrate and this HfO2/Al2O3 capping layer. All stacks provide very good passivation of the silicon surface. The measured effective carrier lifetimes are between 1 and 30 ms. This charge control in Al2O3 nanolayers allows the construction of zero-fixed-charge passivation layers as well as layers with tailored fixed charge densities for future solar cell concepts and other field-effect based devices.

Divided attention limits perception of 3-D object shapes

PubMed Central

Scharff, Alec; Palmer, John; Moore, Cathleen M.

2013-01-01

Can one perceive multiple object shapes at once? We tested two benchmark models of object shape perception under divided attention: an unlimited-capacity and a fixed-capacity model. Under unlimited-capacity models, shapes are analyzed independently and in parallel. Under fixed-capacity models, shapes are processed at a fixed rate (as in a serial model). To distinguish these models, we compared conditions in which observers were presented with simultaneous or sequential presentations of a fixed number of objects (The extended simultaneous-sequential method: Scharff, Palmer, & Moore, 2011a, 2011b). We used novel physical objects as stimuli, minimizing the role of semantic categorization in the task. Observers searched for a specific object among similar objects. We ensured that non-shape stimulus properties such as color and texture could not be used to complete the task. Unpredictable viewing angles were used to preclude image-matching strategies. The results rejected unlimited-capacity models for object shape perception and were consistent with the predictions of a fixed-capacity model. In contrast, a task that required observers to recognize 2-D shapes with predictable viewing angles yielded an unlimited capacity result. Further experiments ruled out alternative explanations for the capacity limit, leading us to conclude that there is a fixed-capacity limit on the ability to perceive 3-D object shapes. PMID:23404158

Separability of electrostatic and hydrodynamic forces in particle electrophoresis

NASA Astrophysics Data System (ADS)

Todd, Brian A.; Cohen, Joel A.

2011-09-01

By use of optical tweezers we explicitly measure the electrostatic and hydrodynamic forces that determine the electrophoretic mobility of a charged colloidal particle. We test the ansatz of O'Brien and White [J. Chem. Soc. Faraday IIJCFTBS0300-923810.1039/f29787401607 74, 1607 (1978)] that the electrostatically and hydrodynamically coupled electrophoresis problem is separable into two simpler problems: (1) a particle held fixed in an applied electric field with no flow field and (2) a particle held fixed in a flow field with no applied electric field. For a system in the Helmholtz-Smoluchowski and Debye-Hückel regimes, we find that the electrostatic and hydrodynamic forces measured independently accurately predict the electrophoretic mobility within our measurement precision of 7%; the O'Brien and White ansatz holds under the conditions of our experiment.

Subtle alternating electrocardiographic morphology as an indicator of decreased cardiac electrical stability

NASA Technical Reports Server (NTRS)

Smith, J. M.; Blue, B.; Clancy, E.; Valeri, C. R.; Cohen, R. J.

1985-01-01

Observations from finite-element computer models, together with analytic developments based on percolation theory have suggested that subtle fluctuations of ECG morphology might serve as an indicator diminished cardiac electrical stability. With fixed-rate atrial pacing in canines, we have previously observed a pattern of alternation in T wave energy which correlated with cardiac electrical stability. We report here on a series of 20 canine experiments in which cardiac electrical stability (measured via Ventricular Fibrillation Threshold determination) was compared to a non-degenerate, multidimensional measurement of the degree of alternating activity present in the ECG complex morphology. The decrease in cardiac electrical stability brought on by both coronary artery occlusion and systemic hypothermia was consistently accompanied by subtle alternation in ECG morphology, with the absolute degree of alternating activity being significantly (negatively) correlated with cardiac electrical stability.

Applying electric field to charged and polar particles between metallic plates: extension of the Ewald method.

PubMed

Takae, Kyohei; Onuki, Akira

2013-09-28

We develop an efficient Ewald method of molecular dynamics simulation for calculating the electrostatic interactions among charged and polar particles between parallel metallic plates, where we may apply an electric field with an arbitrary size. We use the fact that the potential from the surface charges is equivalent to the sum of those from image charges and dipoles located outside the cell. We present simulation results on boundary effects of charged and polar fluids, formation of ionic crystals, and formation of dipole chains, where the applied field and the image interaction are crucial. For polar fluids, we find a large deviation of the classical Lorentz-field relation between the local field and the applied field due to pair correlations along the applied field. As general aspects, we clarify the difference between the potential-fixed and the charge-fixed boundary conditions and examine the relationship between the discrete particle description and the continuum electrostatics.

Wavelength converter placement for different RWA algorithms in wavelength-routed all-optical networks

NASA Astrophysics Data System (ADS)

Chu, Xiaowen; Li, Bo; Chlamtac, Imrich

2002-07-01

Sparse wavelength conversion and appropriate routing and wavelength assignment (RWA) algorithms are the two key factors in improving the blocking performance in wavelength-routed all-optical networks. It has been shown that the optimal placement of a limited number of wavelength converters in an arbitrary mesh network is an NP complete problem. There have been various heuristic algorithms proposed in the literature, in which most of them assume that a static routing and random wavelength assignment RWA algorithm is employed. However, the existing work shows that fixed-alternate routing and dynamic routing RWA algorithms can achieve much better blocking performance. Our study in this paper further demonstrates that the wavelength converter placement and RWA algorithms are closely related in the sense that a well designed wavelength converter placement mechanism for a particular RWA algorithm might not work well with a different RWA algorithm. Therefore, the wavelength converter placement and the RWA have to be considered jointly. The objective of this paper is to investigate the wavelength converter placement problem under fixed-alternate routing algorithm and least-loaded routing algorithm. Under the fixed-alternate routing algorithm, we propose a heuristic algorithm called Minimum Blocking Probability First (MBPF) algorithm for wavelength converter placement. Under the least-loaded routing algorithm, we propose a heuristic converter placement algorithm called Weighted Maximum Segment Length (WMSL) algorithm. The objective of the converter placement algorithm is to minimize the overall blocking probability. Extensive simulation studies have been carried out over three typical mesh networks, including the 14-node NSFNET, 19-node EON and 38-node CTNET. We observe that the proposed algorithms not only outperform existing wavelength converter placement algorithms by a large margin, but they also can achieve almost the same performance comparing with full wavelength conversion under the same RWA algorithm.

Electromagnetic and scalar diffraction by a right-angled wedge with a uniform surface impedance

NASA Technical Reports Server (NTRS)

Hwang, Y. M.

1974-01-01

The diffraction of an electromagnetic wave by a perfectly-conducting right-angled wedge with one surface covered by a dielectric slab or absorber is considered. The effect of the coated surface is approximated by a uniform surface impedance. The solution of the normally incident electromagnetic problem is facilitated by introducing two scalar fields which satisfy a mixed boundary condition on one surface of the wedge and a Neumann of Dirichlet boundary condition on the other. A functional transformation is employed to simplify the boundary conditions so that eigenfunction expansions can be obtained for the resulting Green's functions. The eigenfunction expansions are transformed into the integral representations which then are evaluated asymptotically by the modified Pauli-Clemmow method of steepest descent. A far zone approximation is made to obtain the scattered field from which the diffraction coefficient is found for scalar plane, cylindrical or sperical wave incident on the edge. With the introduction of a ray-fixed coordinate system, the dyadic diffraction coefficient for plane or cylindrical EM waves normally indicent on the edge is reduced to the sum of two dyads which can be written alternatively as a 2 X 2 diagonal matrix.

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

Colliat, J.L.; Boisard, P.; Andersen, K.

Shallow caisson foundations are considered as alternative anchors for permanent mooring of a process barge at an oil and gas field developed by ELF Congo in the Gulf of Guinea. The 12 mooring lines are scheduled to be installed on site in July 1995 and the process barge will be connected in 1996 for start of production. With a water depth of about 170m, this field will be the deepest one offshore Western Africa to date. The soils at the site consist of soft normally consolidated clays. The paper presents the results of a comparative study of potential anchor solutionsmore » for this production barge, including high capacity drag anchors, driven piles, and shallow caisson foundations installed by underpressure. This comparative study, including design, construction, and installation of the mooring system, has shown that the caisson foundations represent the best suited solution, technically as well as on an economical point of view, because of the following advantages: (1) vertical load capability, thus allowing to reduce the anchoring pattern, (2) once positioned on the seabed, the location of each anchor is fixed and known with accuracy, and (3) more simple and shorter installation procedure, since caisson anchors, as piles, do not require to be proof-loaded on site.« less

Structural and magnetic study of La0.7Sr0.3MnO3 nanoparticles and AC magnetic heating characteristics for hyperthermia applications

NASA Astrophysics Data System (ADS)

Manh, D. H.; Phong, P. T.; Nam, P. H.; Tung, D. K.; Phuc, N. X.; Lee, In-Ja

We investigated structural and magnetic properties and alternating current magnetic heating characteristics of La0.7Sr0.3MnO3 nanoparticles with respect to the possible application for magnetic hyperthermia treatments. Using Rietveld Profile refinement of powder X-ray diffraction data, the hexagonal structure has been observed. The particle sizes varied from 20 to 50 nm as the annealing temperature increases from 700 to 900 °C. The hysteresis loop is not observed and the good fit of Langevin function with magnetization data reveals the superparamagnetic nature at room temperature for all samples. Characteristic magnetic parameters of the particles including saturation magnetization in the temperature range 10-300 K, an effective anisotropy constant and a magnetocrystalline anisotropy constant have been determined. The Specific Absorption Rate for 15 mg/mL sample concentration was measured in alternating magnetic fields of 50-80 Oe at a fixed frequency of 236 kHz. In addition, the intrinsic loss power (ILP) has been calculated from SAR values. It is believed that La0.7Sr0.3MnO3 nanoparticles with a high ILP will be useful for the in situ hyperthermia treatment of cancer.

Computing Real-time Streamflow Using Emerging Technologies: Non-contact Radars and the Probability Concept

NASA Astrophysics Data System (ADS)

Fulton, J. W.; Bjerklie, D. M.; Jones, J. W.; Minear, J. T.

2015-12-01

Measuring streamflow, developing, and maintaining rating curves at new streamgaging stations is both time-consuming and problematic. Hydro 21 was an initiative by the U.S. Geological Survey to provide vision and leadership to identify and evaluate new technologies and methods that had the potential to change the way in which streamgaging is conducted. Since 2014, additional trials have been conducted to evaluate some of the methods promoted by the Hydro 21 Committee. Emerging technologies such as continuous-wave radars and computationally-efficient methods such as the Probability Concept require significantly less field time, promote real-time velocity and streamflow measurements, and apply to unsteady flow conditions such as looped ratings and unsteady-flood flows. Portable and fixed-mount radars have advanced beyond the development phase, are cost effective, and readily available in the marketplace. The Probability Concept is based on an alternative velocity-distribution equation developed by C.-L. Chiu, who pioneered the concept. By measuring the surface-water velocity and correcting for environmental influences such as wind drift, radars offer a reliable alternative for measuring and computing real-time streamflow for a variety of hydraulic conditions. If successful, these tools may allow us to establish ratings more efficiently, assess unsteady flow conditions, and report real-time streamflow at new streamgaging stations.

Biogeochemistry and biodiversity interact to govern N2 fixers (Fabaceae) across Amazon tropical forests

NASA Astrophysics Data System (ADS)

Batterman, Sarah; Hedin, Lars; Lloyd, Jon; Quesada, Beto

2015-04-01

Dinitrogen (N2)-fixing trees in the Fabaceae fulfill a central role in tropical rainforests by supplying nitrogen from the atmosphere, yet whether they will support a forest CO2 sink in the future by alleviating nitrogen limitation may depend on whether and how they are controlled by local environmental conditions. Theory predicts that soil nutrients govern the function of N2 fixers, yet there have been no large-scale field-based tests of this idea. Moreover, recent findings indicate that N2-fixing species behave differently in biogeochemical cycles, suggesting that any environmental control may differ by species, and that the diversity of N2-fixing trees may be critical for ensuring tropical forest function. In this talk, we will use the RAINFOR dataset of 108 (~1.0 ha) lowland tropical rainforest plots from across the Amazon Basin to test whether the abundance and diversity of N2-fixing trees are controlled by soil nutrient availability (i.e., increasing with phosphorus and decreasing with nitrogen), or if fixer abundance and diversity simply follow the dynamics of all tree species. We also test an alternative - but not mutually exclusive - hypothesis that the governing factor for fixers is forest disturbance. Results show a surprising lack of control by local nutrients or disturbance on the abundance or diversity of N2 fixers. The dominant driver of fixer diversity was the total number of tree species, with fixers comprising 10% of all species in a forest plot (R2 = 0.75, linear regression). When considering the dominant taxa of N2 fixers (Inga, Swartzia, Tachigali) alone, environmental factors (nitrogen, phosphorus and disturbance) became important and clearly governed their abundance. These taxa, which contain >60% of N2-fixing trees in the data set, appear to have evolved to specialize in different local environmental conditions. The strong biogeochemistry-by-biodiversity interaction observed here points to a need to consider individual species or taxa of N2 fixers and their differential constraints and roles in biogeochemical cycles across tropical forests. Such an individual-based perspective may improve our understanding of the ability of N2 fixers to overcome any future nitrogen constraints as CO2 levels rise in the atmosphere.

The effect of an exogenous magnetic field on neural coding in deep spiking neural networks.

PubMed

Guo, Lei; Zhang, Wei; Zhang, Jialei

2018-01-01

A ten-layer feed forward network is constructed in the presence of an exogenous alternating magnetic field. Specifically, our results indicate that for rate coding, the firing rate is significantly increased in the presence of an exogenous alternating magnetic field and particularly with increasing enhancement of the alternating magnetic field amplitude. For temporal coding, the interspike intervals of the spiking sequence are decreased and the distribution of the interspike intervals of the spiking sequence tends to be uniform in the presence of alternating magnetic field.

Treatment adherence and real-life effectiveness of topical therapy in patients with mild or moderate psoriasis: uptake of scientific evidence in clinical practice and dermatologists' preferences for alternative treatment options.

PubMed

Neri, L; Miracapillo, A

2015-02-01

Topical corticosteroids and the vitamin D analogue calcipotriol are the cornerstone of therapy for patients with mild-to-moderate plaque psoriasis. Lack of patients' adherence leads to suboptimal effectiveness of topical therapy in real-life practice. The fixed combination betamethasone/calcipotriol gel is more effective and safe than the administration of single components and may enhance patients' adherence. We aimed at evaluating the pattern of care and dermatologists' expert opinion toward the available topical treatments for the management of mild-to-moderate psoriasis in Italy. We enrolled 242 Italian dermatologists and collected information related to their practice pattern and opinion toward available topical treatments with a face-to-face structured interview. We evaluated dermatologists' ratings of therapy with 16 items tapping their opinion toward the relevance and satisfaction toward 8 therapy attributes in clinical practices which tapped aspects of real-life effectiveness, adherence promotion, toxicity, convenience of use. Ratings occurred along a 10-point scale. We compared single-attribute and weighted overall therapy ratings across alternative treatment options with random-intercept linear models to account for ratings clustering within dermatologists. There was a wide variation in practice patterns: 1/3 of dermatologist had seen more than 30 patients with psoriasis while around 1/4 had seen less than 10 patients. The fixed combination betamethasone/calcipotriol gel was considered superior to monotherapies in all the eight attributes considered which tapped aspects of real-life effectiveness, adherence promotion, toxicity, convenience of use. Participant dermatologists' strongly preferred the fixed betamethasone/calcipotriol combination gel over both the fixed combination ointment formulation and corticosteroid or vitamin D analogues monotherapies. Such findings are in line with evidence from randomized controlled trials and few observational studies demonstrating superior clinical outcomes, quality of life, tolerability and lower risk of side effect in patients treated with the fixed combination of betamethasone/calcipotriol gel.

Removal of dioxins and furans from flue gases by non-flammable adsorbents in a fixed bed.

PubMed

Fell, H J; Tuczek, M

1998-01-01

The presented adsorption--process KOMBISORBON is applied for high efficient off-gas purification, preferably of polychlorinated dioxins and furans from off-gas of incineration plants, which are generated, when these are operated under unfavourable conditions [2]. This off-gas purification process complies with german laws, which limit the concentration of these substances to less than 0.1 ng toxicity equivalents (TE) per cubic metre of gas [1]. The adsorbent, the adsorption process and its plant concept (fixed bed) is described in detail including economics and obtained operation results. Alternative removal technologies are briefly outlined.

Experimental study on heat transfer enhancement of laminar ferrofluid flow in horizontal tube partially filled porous media under fixed parallel magnet bars

NASA Astrophysics Data System (ADS)

Sheikhnejad, Yahya; Hosseini, Reza; Saffar Avval, Majid

2017-02-01

In this study, steady state laminar ferroconvection through circular horizontal tube partially filled with porous media under constant heat flux is experimentally investigated. Transverse magnetic fields were applied on ferrofluid flow by two fixed parallel magnet bar positioned on a certain distance from beginning of the test section. The results show promising notable enhancement in heat transfer as a consequence of partially filled porous media and magnetic field, up to 2.2 and 1.4 fold enhancement were observed in heat transfer coefficient respectively. It was found that presence of both porous media and magnetic field simultaneously can highly improve heat transfer up to 2.4 fold. Porous media of course plays a major role in this configuration. Virtually, application of Magnetic field and porous media also insert higher pressure loss along the pipe which again porous media contribution is higher that magnetic field.

48 CFR 48.104-2 - Sharing acquisition savings.

Code of Federal Regulations, 2010 CFR

2010-10-01

... CONTRACT MANAGEMENT VALUE ENGINEERING Policies and Procedures 48.104-2 Sharing acquisition savings. (a... value engineering clause or alternate used, and the type of savings, as follows: Government/Contractor... percent for fixed-price contracts; or (2) 75 percent for cost-reimbursement contracts. Value engineering...

Online 1990.

ERIC Educational Resources Information Center

Goldstein, Morris

This paper examines the co-existence of online and CD-ROM technologies in terms of their existing pricing structures, marketing strategies, functionality, and future roles. "Fixed Price Unlimited Usage" (FPUU) pricing and flat-rate pricing are discussed as viable alternatives to current pricing practices. In addition, it is argued that the…

A NOVEL SEPARATION TECHNOLOGY FOR REMOVAL RECOVERY OF METALS FROM AQUEOUS SOLUTIONS

EPA Science Inventory

Recovery/Recycling of metal ions from industrial process waste streams is a preferred alternative to disposal by conventional techniques. This paper presents methods for preparation of inorganic chemically active adsorbents to be used in fixed bed adsorbers. Methods for immobiliz...

Fixed bed column study for water defluoridation using neem oil-phenolic resin treated plant bio-sorbent.

PubMed

Manna, Suvendu; Saha, Prosenjit; Roy, Debasis; Adhikari, Basudam; Das, Papita

2018-04-15

Fluoride has both detrimental and beneficial effects on living beings depending on the concentration and consumption periods. The study presented in this article investigated the feasibility of using neem oil phenolic resin treated lignocellulosic bio-sorbents for fluoride removal from water through fixed bed column study. Results indicated that treated bio-sorbents could remove fluoride both from synthetic and groundwater with variable bed depth, flow rate, fluoride concentration and column diameter. Data obtained from this study indicated that columns with the thickest bed, lowest flow rate, and fluoride concentration showed best column performance. Bio-sorbents used in this study are regenerable and reusable for more than five cycles. The initial materials cost needed to remove one gram of fluoride also found to be lower than the available alternatives. This makes the process more promising candidate to be used for fluoride removal. In addition, the process is also technically advantageous over the available alternatives. Copyright © 2018 Elsevier Ltd. All rights reserved.

Developments and Validations of Fully Coupled CFD and Practical Vortex Transport Method for High-Fidelity Wake Modeling in Fixed and Rotary Wing Applications

NASA Technical Reports Server (NTRS)

Anusonti-Inthra, Phuriwat

2010-01-01

A novel Computational Fluid Dynamics (CFD) coupling framework using a conventional Reynolds-Averaged Navier-Stokes (BANS) solver to resolve the near-body flow field and a Particle-based Vorticity Transport Method (PVTM) to predict the evolution of the far field wake is developed, refined, and evaluated for fixed and rotary wing cases. For the rotary wing case, the RANS/PVTM modules are loosely coupled to a Computational Structural Dynamics (CSD) module that provides blade motion and vehicle trim information. The PVTM module is refined by the addition of vortex diffusion, stretching, and reorientation models as well as an efficient memory model. Results from the coupled framework are compared with several experimental data sets (a fixed-wing wind tunnel test and a rotary-wing hover test).

The ecology and evolution of animal medication: genetically fixed response versus phenotypic plasticity.

PubMed

Choisy, Marc; de Roode, Jacobus C

2014-08-01

Animal medication against parasites can occur either as a genetically fixed (constitutive) or phenotypically plastic (induced) behavior. Taking the tritrophic interaction between the monarch butterfly Danaus plexippus, its protozoan parasite Ophryocystis elektroscirrha, and its food plant Asclepias spp. as a test case, we develop a game-theory model to identify the epidemiological (parasite prevalence and virulence) and environmental (plant toxicity and abundance) conditions that predict the evolution of genetically fixed versus phenotypically plastic forms of medication. Our model shows that the relative benefits (the antiparasitic properties of medicinal food) and costs (side effects of medicine, the costs of searching for medicine, and the costs of plasticity itself) crucially determine whether medication is genetically fixed or phenotypically plastic. Our model suggests that animals evolve phenotypic plasticity when parasite risk (a combination of virulence and prevalence and thus a measure of the strength of parasite-mediated selection) is relatively low to moderately high and genetically fixed medication when parasite risk becomes very high. The latter occurs because at high parasite risk, the costs of plasticity are outweighed by the benefits of medication. Our model provides a simple and general framework to study the conditions that drive the evolution of alternative forms of animal medication.

COMPARISON OF LABORATORY SUBSAMPLING METHODS OF BENTHIC SAMPLES FROM BOATABLE RIVERS USING ACTUAL AND SIMULATED COUNT DATA

EPA Science Inventory

We examined the effects of using a fixed-count subsample of 300 organisms on metric values using macroinvertebrate samples collected with 3 field sampling methods at 12 boatable river sites. For each sample, we used metrics to compare an initial fixed-count subsample of approxima...

Thin silicon layer SOI power device with linearly-distance fixed charge islands

NASA Astrophysics Data System (ADS)

Yuan, Zuo; Haiou, Li; Jianghui, Zhai; Ning, Tang; Shuxiang, Song; Qi, Li

2015-05-01

A new high-voltage LDMOS with linearly-distanced fixed charge islands is proposed (LFI LDMOS). A lot of linearly-distanced fixed charge islands are introduced by implanting the Cs or I ion into the buried oxide layer and dynamic holes are attracted and accumulated, which is crucial to enhance the electric field of the buried oxide and the vertical breakdown voltage. The surface electric field is improved by increasing the distance between two adjacent fixed charge islands from source to drain, which lead to the higher concentration of the drift region and a lower on-resistance. The numerical results indicate that the breakdown voltage of 500 V with Ld = 45 μm is obtained in the proposed device in comparison to 209 V of conventional LDMOS, while maintaining low on-resistance. Project supported by the Guangxi Natural Science Foundation of China (No. 2013GXNSFAA019335), the Guangxi Department of Education Project (No.201202ZD041), the China Postdoctoral Science Foundation Project (Nos. 2012M521127, 2013T60566), and the National Natural Science Foundation of China (Nos. 61361011, 61274077, 61464003).

Influence of the Redundant Verification and the Non-Redundant Verification on the Hydraulic Tomography

NASA Astrophysics Data System (ADS)

Wei, T. B.; Chen, Y. L.; Lin, H. R.; Huang, S. Y.; Yeh, T. C. J.; Wen, J. C.

2016-12-01

In the groundwater study, it estimated the heterogeneous spatial distribution of hydraulic Properties, there were many scholars use to hydraulic tomography (HT) from field site pumping tests to estimate inverse of heterogeneous spatial distribution of hydraulic Properties, to prove the most of most field site aquifer was heterogeneous hydrogeological parameters spatial distribution field. Many scholars had proposed a method of hydraulic tomography to estimate heterogeneous spatial distribution of hydraulic Properties of aquifer, the Huang et al. [2011] was used the non-redundant verification analysis of pumping wells changed, observation wells fixed on the inverse and the forward, to reflect the feasibility of the heterogeneous spatial distribution of hydraulic Properties of field site aquifer of the non-redundant verification analysis on steady-state model.From post literature, finding only in steady state, non-redundant verification analysis of pumping well changed location and observation wells fixed location for inverse and forward. But the studies had not yet pumping wells fixed or changed location, and observation wells fixed location for redundant verification or observation wells change location for non-redundant verification of the various combinations may to explore of influences of hydraulic tomography method. In this study, it carried out redundant verification method and non-redundant verification method for forward to influences of hydraulic tomography method in transient. And it discuss above mentioned in NYUST campus sites the actual case, to prove the effectiveness of hydraulic tomography methods, and confirmed the feasibility on inverse and forward analysis from analysis results.Keywords: Hydraulic Tomography, Redundant Verification, Heterogeneous, Inverse, Forward

Clinical acceptability of metal-ceramic fixed partial dental prosthesis fabricated with direct metal laser sintering technique-5 year follow-up

PubMed Central

Prabhu, Radhakrishnan; Prabhu, Geetha; Baskaran, Eswaran; Arumugam, Eswaran M.

2016-01-01

Statement of Problem: In recent years, direct metal laser sintered (DMLS) metal-ceramic-based fixed partial denture prostheses have been used as an alternative to conventional metal-ceramic fixed partial denture prostheses. However, clinical studies for evaluating their long-term clinical survivability and acceptability are limited. Aims and Objective: The aim of this study was to assess the efficacy of metal-ceramic fixed dental prosthesis fabricated with DMLS technique, and its clinical acceptance on long-term clinical use. Materials and Methods: The study group consisted of 45 patients who were restored with posterior three-unit fixed partial denture prosthesis made using direct laser sintered metal-ceramic restorations. Patient recall and clinical examination of the restorations were done after 6months and every 12 months thereafter for the period of 60 months. Clinical examination for evaluation of longevity of restorations was done using modified Ryge criteria which included chipping of the veneered ceramic, connector failure occurring in the fixed partial denture prosthesis, discoloration at the marginal areas of the veneered ceramic, and marginal adaptation of the metal and ceramic of the fixed denture prosthesis. Periapical status was assessed using periodical radiographs during the study period. Survival analysis was made using the Kaplan–Meier method. Results: None of the patients had failure of the connector of the fixed partial denture prostheses during the study period. Two exhibited biological changes which included periapical changes and proximal caries adjacent to the abutments. Conclusion: DMLS metal-ceramic fixed partial denture prosthesis had a survival rate of 95.5% and yielded promising results during the 5-year clinical study. PMID:27141171

Human's choices in situations of time-based diminishing returns.

PubMed Central

Hackenberg, T D; Axtell, S A

1993-01-01

Three experiments examined adult humans' choices in situations with contrasting short-term and long-term consequences. Subjects were given repeated choices between two time-based schedules of points exchangeable for money: a fixed schedule and a progressive schedule that began at 0 s and increased by 5 s with each point delivered by that schedule. Under "reset" conditions, choosing the fixed schedule not only produced a point but it also reset the requirements of the progressive schedule to 0 s. In the first two experiments, reset conditions alternated with "no-reset" conditions, in which progressive-schedule requirements were independent of fixed-schedule choices. Experiment 1 entailed choices between a progressive-interval schedule and a fixed-interval schedule, the duration of which varied across conditions. Switching from the progressive- to the fixed-interval schedule was systematically related to fixed-interval size in 4 of 8 subjects, and in all subjects occurred consistently sooner in the progressive-schedule sequence under reset than under no-reset procedures. The latter result was replicated in a second experiment, in which choices between progressive- and fixed-interval schedules were compared with choices between progressive- and fixed-time schedules. In Experiment 3, switching patterns under reset conditions were unrelated to variations in intertrial interval. In none of the experiments did orderly choice patterns depend on verbal descriptions of the contingencies or on schedule-controlled response patterns in the presence of the chosen schedules. The overall pattern of results indicates control of choices by temporarily remote consequences, and is consistent with versions of optimality theory that address performance in situations of diminishing returns. PMID:8315364

40 CFR 35.2211 - Field testing for Innovative and Alternative Technology Report.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Treatment Works § 35.2211 Field testing for Innovative and Alternative Technology Report. The grantee shall... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Field testing for Innovative and Alternative Technology Report. 35.2211 Section 35.2211 Protection of Environment ENVIRONMENTAL PROTECTION...

40 CFR 35.2211 - Field testing for Innovative and Alternative Technology Report.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Treatment Works § 35.2211 Field testing for Innovative and Alternative Technology Report. The grantee shall... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Field testing for Innovative and Alternative Technology Report. 35.2211 Section 35.2211 Protection of Environment ENVIRONMENTAL PROTECTION...

40 CFR 35.2211 - Field testing for Innovative and Alternative Technology Report.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Treatment Works § 35.2211 Field testing for Innovative and Alternative Technology Report. The grantee shall... 40 Protection of Environment 1 2012-07-01 2012-07-01 false Field testing for Innovative and Alternative Technology Report. 35.2211 Section 35.2211 Protection of Environment ENVIRONMENTAL PROTECTION...

40 CFR 35.2211 - Field testing for Innovative and Alternative Technology Report.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Treatment Works § 35.2211 Field testing for Innovative and Alternative Technology Report. The grantee shall... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Field testing for Innovative and Alternative Technology Report. 35.2211 Section 35.2211 Protection of Environment ENVIRONMENTAL PROTECTION...

40 CFR 35.2211 - Field testing for Innovative and Alternative Technology Report.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Treatment Works § 35.2211 Field testing for Innovative and Alternative Technology Report. The grantee shall... 40 Protection of Environment 1 2014-07-01 2014-07-01 false Field testing for Innovative and Alternative Technology Report. 35.2211 Section 35.2211 Protection of Environment ENVIRONMENTAL PROTECTION...

Tensor gauge condition and tensor field decomposition

NASA Astrophysics Data System (ADS)

Zhu, Ben-Chao; Chen, Xiang-Song

2015-10-01

We discuss various proposals of separating a tensor field into pure-gauge and gauge-invariant components. Such tensor field decomposition is intimately related to the effort of identifying the real gravitational degrees of freedom out of the metric tensor in Einstein’s general relativity. We show that as for a vector field, the tensor field decomposition has exact correspondence to and can be derived from the gauge-fixing approach. The complication for the tensor field, however, is that there are infinitely many complete gauge conditions in contrast to the uniqueness of Coulomb gauge for a vector field. The cause of such complication, as we reveal, is the emergence of a peculiar gauge-invariant pure-gauge construction for any gauge field of spin ≥ 2. We make an extensive exploration of the complete tensor gauge conditions and their corresponding tensor field decompositions, regarding mathematical structures, equations of motion for the fields and nonlinear properties. Apparently, no single choice is superior in all aspects, due to an awkward fact that no gauge-fixing can reduce a tensor field to be purely dynamical (i.e. transverse and traceless), as can the Coulomb gauge in a vector case.

Learning by Employing Educational Multimedia in Field-Dependent and Field-Independent Cognitive Styles

ERIC Educational Resources Information Center

Karamaerouz, Mohamad Javad; Abdi, Ali; Laei, Soosan

2013-01-01

Cognitive learning styles are relatively fixed procedures using which individuals receive, process and organize information. This paper aims to examine academic achievement in English for both field dependence and field independence learning styles using educational multimedia. The sample of the study consisted of 40 second-grade female students…

Customized sampling plans : a guide to alternative sampling techniques for National Transit Database reporting

DOT National Transportation Integrated Search

2004-05-01

For estimating the system total unlinked passenger trips and passenger miles of a fixed-route bus system for the National Transit Database (NTD), the FTA approved sampling plans may either over-sample or do not yield FTAs required confidence and p...

Ambulance ride: fixed or floating stretcher?

PubMed Central

Snook, R; Pacifico, R

1976-01-01

The alternatives of a purpose-bult ambulance and a specially designed stretcher suspension system were considered and the features of the latter assessed by subjective and objective tests. The results showed a significant improvement in the quality of the ride offered to the patient. Images FIG 2 PMID:947448

Fixed Route Comprehensive Operational Analysis, 1994 Operating Year. Fourth Installment, Route 2: Berkshire Shopping Center Analysis

DOT National Transportation Integrated Search

1995-03-01

The study evaluated the performance of the service, analyzed possible alternatives, and recommended several service changes, which took effect in August of 1993. By use of ongoing data collection, HART intends to provide continual analysis of the ser...

Cost of riparian buffer zones: A comparison of hydrologically adapted site-specific riparian buffers with traditional fixed widths

NASA Astrophysics Data System (ADS)

Tiwari, T.; Lundström, J.; Kuglerová, L.; Laudon, H.; Öhman, K.; Ågren, A. M.

2016-02-01

Traditional approaches aiming at protecting surface waters from the negative impacts of forestry often focus on retaining fixed width buffer zones around waterways. While this method is relatively simple to design and implement, it has been criticized for ignoring the spatial heterogeneity of biogeochemical processes and biodiversity in the riparian zone. Alternatively, a variable width buffer zone adapted to site-specific hydrological conditions has been suggested to improve the protection of biogeochemical and ecological functions of the riparian zone. However, little is known about the monetary value of maintaining hydrologically adapted buffer zones compared to the traditionally used fixed width ones. In this study, we created a hydrologically adapted buffer zone by identifying wet areas and groundwater discharge hotspots in the riparian zone. The opportunity cost of the hydrologically adapted riparian buffer zones was then compared to that of the fixed width zones in a meso-scale boreal catchment to determine the most economical option of designing riparian buffers. The results show that hydrologically adapted buffer zones were cheaper per hectare than the fixed width ones when comparing the total cost. This was because the hydrologically adapted buffers included more wetlands and low productive forest areas than the fixed widths. As such, the hydrologically adapted buffer zones allows more effective protection of the parts of the riparian zones that are ecologically and biogeochemically important and more sensitive to disturbances without forest landowners incurring any additional cost than fixed width buffers.

An Energy Balance Model to Predict Chemical Partitioning in a Photosynthetic Microbial Mat

NASA Technical Reports Server (NTRS)

Hoehler, Tori M.; Albert, Daniel B.; DesMarais, David J.

2006-01-01

Studies of biosignature formation in photosynthetic microbial mat communities offer potentially useful insights with regards to both solar and extrasolar astrobiology. Biosignature formation in such systems results from the chemical transformation of photosynthetically fixed carbon by accessory microorganisms. This fixed carbon represents a source not only of reducing power, but also energy, to these organisms, so that chemical and energy budgets should be coupled. We tested this hypothesis by applying an energy balance model to predict the fate of photosynthetic productivity under dark, anoxic conditions. Fermentation of photosynthetically fixed carbon is taken to be the only source of energy available to cyanobacteria in the absence of light and oxygen, and nitrogen fixation is the principal energy demand. The alternate fate for fixed carbon is to build cyanobacterial biomass with Redfield C:N ratio. The model predicts that, under completely nitrogen-limited conditions, growth is optimized when 78% of fixed carbon stores are directed into fermentative energy generation, with the remainder allocated to growth. These predictions were compared to measurements made on microbial mats that are known to be both nitrogen-limited and populated by actively nitrogen-fixing cyanobacteria. In these mats, under dark, anoxic conditions, 82% of fixed carbon stores were diverted into fermentation. The close agreement between these independent approaches suggests that energy balance models may provide a quantitative means of predicting chemical partitioning within such systems - an important step towards understanding how biological productivity is ultimately partitioned into biosignature compounds.

A simple quantitative diagnostic alternative for MGMT DNA-methylation testing on RCL2 fixed paraffin embedded tumors using restriction coupled qPCR.

PubMed

Pulverer, Walter; Hofner, Manuela; Preusser, Matthias; Dirnberger, Elisabeth; Hainfellner, Johannes A; Weinhaeusel, Andreas

2014-01-01

MGMT promoter methylation is associated with favorable prognosis and chemosensitivity in glioblastoma multiforme (GBM), especially in elderly patients. We aimed to develop a simple methylation-sensitive restriction enzyme (MSRE)-based quantitative PCR (qPCR) assay, allowing the quantification of MGMT promoter methylation. DNA was extracted from non-neoplastic brain (n = 24) and GBM samples (n = 20) upon 3 different sample conservation conditions (-80 °C, formalin-fixed and paraffin-embedded (FFPE); RCL2-fixed). We evaluated the suitability of each fixation method with respect to the MSRE-coupled qPCR methylation analyses. Methylation data were validated by MALDITOF. qPCR was used for evaluation of alternative tissue conservation procedures. DNA from FFPE tissue failed reliable testing; DNA from both RCL2-fixed and fresh frozen tissues performed equally well and was further used for validation of the quantitative MGMT methylation assay (limit of detection (LOD): 19.58 pg), using individual's undigested sample DNA for calibration. MGMT methylation analysis in non-neoplastic brain identified a background methylation of 0.10 ± 11% which we used for defining a cut-off of 0.32% for patient stratification. Of GBM patients 9 were MGMT methylationpositive (range: 0.56 - 91.95%), and 11 tested negative. MALDI-TOF measurements resulted in a concordant classification of 94% of GBM samples in comparison to qPCR. The presented methodology allows quantitative MGMT promoter methylation analyses. An amount of 200 ng DNA is sufficient for triplicate analyses including control reactions and individual calibration curves, thus excluding any DNA qualityderived bias. The combination of RCL2-fixation and quantitative methylation analyses improves pathological routine examination when histological and molecular analyses on limited amounts of tumor samples are necessary for patient stratification.

Box-Cox Mixed Logit Model for Travel Behavior Analysis

NASA Astrophysics Data System (ADS)

Orro, Alfonso; Novales, Margarita; Benitez, Francisco G.

2010-09-01

To represent the behavior of travelers when they are deciding how they are going to get to their destination, discrete choice models, based on the random utility theory, have become one of the most widely used tools. The field in which these models were developed was halfway between econometrics and transport engineering, although the latter now constitutes one of their principal areas of application. In the transport field, they have mainly been applied to mode choice, but also to the selection of destination, route, and other important decisions such as the vehicle ownership. In usual practice, the most frequently employed discrete choice models implement a fixed coefficient utility function that is linear in the parameters. The principal aim of this paper is to present the viability of specifying utility functions with random coefficients that are nonlinear in the parameters, in applications of discrete choice models to transport. Nonlinear specifications in the parameters were present in discrete choice theory at its outset, although they have seldom been used in practice until recently. The specification of random coefficients, however, began with the probit and the hedonic models in the 1970s, and, after a period of apparent little practical interest, has burgeoned into a field of intense activity in recent years with the new generation of mixed logit models. In this communication, we present a Box-Cox mixed logit model, original of the authors. It includes the estimation of the Box-Cox exponents in addition to the parameters of the random coefficients distribution. Probability of choose an alternative is an integral that will be calculated by simulation. The estimation of the model is carried out by maximizing the simulated log-likelihood of a sample of observed individual choices between alternatives. The differences between the predictions yielded by models that are inconsistent with real behavior have been studied with simulation experiments.

C. elegans Demonstrates Distinct Behaviors within a Fixed and Uniform Electric Field

PubMed Central

Chrisman, Steven D.; Waite, Christopher B.; Scoville, Alison G.; Carnell, Lucinda

2016-01-01

C. elegans will orient and travel in a straight uninterrupted path directly towards the negative pole of a DC electric field. We have sought to understand the strategy worms use to navigate to the negative pole in a uniform electric field that is fixed in both direction and magnitude. We examined this behavior by quantifying three aspects of electrotaxis behavior in response to different applied field strengths: the mean approach trajectory angles of the animals’ tracks, turning behavior (pirouettes) and average population speeds. We determined that C. elegans align directly to the negative pole of an electric field at sub-preferred field strength and alter approach trajectories at higher field strengths to maintain taxis within a preferred range we have calculated to be ~ 5V/cm. We sought to identify the sensory neurons responsible for the animals’ tracking to a preferred field strength. eat-4 mutant animals defective in glutamatergic signaling of the amphid sensory neurons are severely electrotaxis defective and ceh-36 mutant animals, which are defective in the terminal differentiation of two types of sensory neurons, AWC and ASE, are partially defective in electrotaxis. To further elucidate the role of the AWC neurons, we examined the role of each of the pair of AWC neurons (AWCOFF and AWCON), which are functionally asymmetric and express different genes. nsy-5/inx-19 mutant animals, which express both neurons as AWCOFF, are severely impaired in electrotaxis behavior while nsy-1 mutants, which express both neurons as AWCON, are able to differentiate field strengths required for navigation to a specific field strength within an electric field. We also tested a strain with targeted genetic ablation of AWC neurons and found that these animals showed only slight disruption of directionality and turning behavior. These results suggest a role for AWC neurons in which complete loss of function is less disruptive than loss of functional asymmetry in electrotaxis behavior within a uniform fixed field. PMID:26998749

Sound-field reproduction systems using fixed-directivity loudspeakers.

PubMed

Poletti, M; Fazi, F M; Nelson, P A

2010-06-01

Sound reproduction systems using open arrays of loudspeakers in rooms suffer from degradations due to room reflections. These reflections can be reduced using pre-compensation of the loudspeaker signals, but this requires calibration of the array in the room, and is processor-intensive. This paper examines 3D sound reproduction systems using spherical arrays of fixed-directivity loudspeakers which reduce the sound field radiated outside the array. A generalized form of the simple source formulation and a mode-matching solution are derived for the required loudspeaker weights. The exterior field is derived and expressions for the exterior power and direct to reverberant ratio are derived. The theoretical results and simulations confirm that minimum interference occurs for loudspeakers which have hyper-cardioid polar responses.

Sidewall containment of liquid metal with horizontal alternating magnetic fields

DOEpatents

Pareg, Walter F.

1990-01-01

An apparatus for confining molten metal with a horizontal alternating magnetic field. In particular, this invention employs a magnet that can produce a horizontal alternating magnetic field to confine a molten metal at the edges of parallel horizontal rollers as a solid metal sheet is cast by counter-rotation of the rollers.

Sidewall containment of liquid metal with horizontal alternating magnetic fields

DOEpatents

Praeg, Walter F.

1995-01-01

An apparatus for confining molten metal with a horizontal alternating magnetic field. In particular, this invention employs a magnet that can produce a horizontal alternating magnetic field to confine a molten metal at the edges of parallel horizontal rollers as a solid metal sheet is cast by counter-rotation of the rollers.

Coast Guard Aircraft: Transfer of Fixed-Wing C-27J Aircraft Is Complex and Further Fleet Purchases Should Coincide with Study Results

DTIC Science & Technology

2015-03-01

C-27J to the Coast Guard. This report assesses (1) the status of the transfer and risks the Coast Guard faces in fielding the transferred aircraft...had transferred 2 of the 14 C-27J aircraft it is receiving from the Air Force to its aircraft maintenance facility, with plans to field 14 fully...Coast Guard continues to receive these aircraft in the near term, the capability and cost of the Coast Guard’s fixed-wing fleet runs the risk of being

Conformal Dimensions via Large Charge Expansion

NASA Astrophysics Data System (ADS)

Banerjee, Debasish; Chandrasekharan, Shailesh; Orlando, Domenico

2018-02-01

We construct an efficient Monte Carlo algorithm that overcomes the severe signal-to-noise ratio problems and helps us to accurately compute the conformal dimensions of large-Q fields at the Wilson-Fisher fixed point in the O (2 ) universality class. Using it, we verify a recent proposal that conformal dimensions of strongly coupled conformal field theories with a global U (1 ) charge can be obtained via a series expansion in the inverse charge 1 /Q . We find that the conformal dimensions of the lowest operator with a fixed charge Q are almost entirely determined by the first few terms in the series.

Field programmable gate array-assigned complex-valued computation and its limits

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

Bernard-Schwarz, Maria, E-mail: maria.bernardschwarz@ni.com; Institute of Applied Physics, TU Wien, Wiedner Hauptstrasse 8, 1040 Wien; Zwick, Wolfgang

We discuss how leveraging Field Programmable Gate Array (FPGA) technology as part of a high performance computing platform reduces latency to meet the demanding real time constraints of a quantum optics simulation. Implementations of complex-valued operations using fixed point numeric on a Virtex-5 FPGA compare favorably to more conventional solutions on a central processing unit. Our investigation explores the performance of multiple fixed point options along with a traditional 64 bits floating point version. With this information, the lowest execution times can be estimated. Relative error is examined to ensure simulation accuracy is maintained.

Conformal Dimensions via Large Charge Expansion.

PubMed

Banerjee, Debasish; Chandrasekharan, Shailesh; Orlando, Domenico

2018-02-09

We construct an efficient Monte Carlo algorithm that overcomes the severe signal-to-noise ratio problems and helps us to accurately compute the conformal dimensions of large-Q fields at the Wilson-Fisher fixed point in the O(2) universality class. Using it, we verify a recent proposal that conformal dimensions of strongly coupled conformal field theories with a global U(1) charge can be obtained via a series expansion in the inverse charge 1/Q. We find that the conformal dimensions of the lowest operator with a fixed charge Q are almost entirely determined by the first few terms in the series.

Environmental setting of fixed sites in the western Lake Michigan drainages, Michigan and Wisconsin

USGS Publications Warehouse

Sullivan, D.J.; Peterson, E.M.; Richards, K.D.

1995-01-01

This report describes selected environmental- setting features for 11 fixed surface-water sites in the Western Lake Michigan Drainages study unit of the National Water-Quality Assessment Pro- gram. The study unit, which includes 10 major river systems draining to Lake Michigan, is bounded on the south by the Illinois State line and extends north to about 31 miles north of Escanaba, Mich. The fixed sites are on the following streams: Peshekee River, Popple River, Menominee River, Pensaukee River, Duck Creek, Tomorrow River, East River, Fox River, North Branch Milwaukee River, Lincoln Creek, and Milwaukee River. Drainage basins above these sites receive runoff from land uses and land covers, bedrock types, and surficial deposits representative of the main types of each of these characteristics in the study unit. Data types collected at the fixed sites include water chemistry; organic compounds and trace elements in streambed sediment and biological tissues; algal, benthic-invertebrate, and fish communities; and aquatic habitat. Field measurements include water temperature, pH, specific conductance, alkalinity, and dissolved oxygen. Results of water- quality field measurements indicate little variation in temperature among the fixed sites. Specific conductance and alkalinity were generally higher at sites underlain by carbonate bedrock than at sites underlain by igneous/metamorphic bedrock. Differences in pH among the fixed sites were less than those for specific conductance and alkalinity, but pH seemed to increase slightly from north to south. Dissolved-oxygen concentration varied more at agricultural sites than at forested and urban sites, perhaps because of higher nutrient inputs at agricultural sites. The information included in this report has been assembled as reference material for ongoing studies at the fixed sites.

Low- Z polymer sample supports for fixed-target serial femtosecond X-ray crystallography

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

Feld, Geoffrey K.; Heymann, Michael; Benner, W. Henry

X-ray free-electron lasers (XFELs) offer a new avenue to the structural probing of complex materials, including biomolecules. Delivery of precious sample to the XFEL beam is a key consideration, as the sample of interest must be serially replaced after each destructive pulse. The fixed-target approach to sample delivery involves depositing samples on a thin-film support and subsequent serial introduction via a translating stage. Some classes of biological materials, including two-dimensional protein crystals, must be introduced on fixed-target supports, as they require a flat surface to prevent sample wrinkling. A series of wafer and transmission electron microscopy (TEM)-style grid supports constructedmore » of low- Z plastic have been custom-designed and produced. Aluminium TEM grid holders were engineered, capable of delivering up to 20 different conventional or plastic TEM grids using fixed-target stages available at the Linac Coherent Light Source (LCLS). As proof-of-principle, X-ray diffraction has been demonstrated from two-dimensional crystals of bacteriorhodopsin and three-dimensional crystals of anthrax toxin protective antigen mounted on these supports at the LCLS. In conclusion, the benefits and limitations of these low- Z fixed-target supports are discussed; it is the authors' belief that they represent a viable and efficient alternative to previously reported fixed-target supports for conducting diffraction studies with XFELs.« less

Decomposing University Grades: A Longitudinal Study of Students and Their Instructors

ERIC Educational Resources Information Center

Beenstock, Michael; Feldman, Dan

2018-01-01

First-degree course grades for a cohort of social science students are matched to their instructors, and are statistically decomposed into departmental, course, instructor, and student components. Student ability is measured alternatively by university acceptance scores, or by fixed effects estimated using panel data methods. After controlling for…

49 CFR Appendix A to Part 611 - Description of Measures Used for Project Evaluation.

Code of Federal Regulations, 2010 CFR

2010-10-01

...) Livable Communities initiatives and local economic activities; (5) Consideration of alternative land use... to fixed guideway systems and extensions may not be limited to a single project). (b) The stability and reliability of the proposed capital financing plan, according to: (i) The stability, reliability...

48 CFR 15.408 - Solicitation provisions and contract clauses.

Code of Federal Regulations, 2013 CFR

2013-10-01

... officer determines that the prospective contractor has demonstrated that its functions provide added value.... If a less economical “make” or “buy” categorization is selected for one or more items of significant value, the contracting officer shall use the clause with— (1) Its Alternate I, if a fixed-price...

48 CFR 15.408 - Solicitation provisions and contract clauses.

Code of Federal Regulations, 2014 CFR

2014-10-01

... officer determines that the prospective contractor has demonstrated that its functions provide added value.... If a less economical “make” or “buy” categorization is selected for one or more items of significant value, the contracting officer shall use the clause with— (1) Its Alternate I, if a fixed-price...

48 CFR 2015.209-70 - Solicitation provisions and contract clauses.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 2052.215-71, Project Officer Authority in applicable solicitations and contracts for cost-reimbursement, cost-plus-fixed-fee, cost-plus-award-fee, cost sharing, labor-hour or time-and-materials, including... for cost type contracts; (2) Section 2052.215-75 Alternate 1 may be used for all solicitations for...

Predicting Organizational Performance: Application of Neurocomputing as an Alternative to Statistical Regression

DTIC Science & Technology

1989-09-01

separate network architetures would otherwise have to be performed for each 𔃼 5 of the nearly 70 cross-validation regressions. Fixing the composition...presentation. The generalized delta rule says the weight of each connection should be changed by an amount proportional to the product of the processing

Price fixing in general practice.

PubMed

Brushin, Bella; Watts, Ian

2008-07-01

Dr Bev Young has just finished packing up her office. This is her last day in her Preston practice of 19 years. Bev enjoys the autonomy of being a solo general practitioner, but lately she finds managing the practice increasingly stressful. Teaming up with a fellow GP seemed a good alternative.

Effects of Class Size on Alternative Educational Outcomes across Disciplines

ERIC Educational Resources Information Center

Cheng, Dorothy A.

2011-01-01

This is the first study to use self-reported ratings of student learning, instructor recommendations, and course recommendations as the outcome measure to estimate class size effects, doing so across 24 disciplines. Fixed-effects models controlling for heterogeneous courses and instructors reveal that increasing enrollment has negative and…

30 CFR 285.710 - When conducting onsite installation inspections, what must the CVA or project engineer do?

Code of Federal Regulations, 2010 CFR

2010-07-01

... SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE RENEWABLE ENERGY ALTERNATE USES OF EXISTING FACILITIES ON THE OUTER CONTINENTAL SHELF Facility Design, Fabrication, and Installation Certified Verification Agent... Facility Design Report and the Fabrication and Installation Report. (b) For a fixed or floating facility...

48 CFR 32.503-9 - Liquidation rates-alternate method.

Code of Federal Regulations, 2011 CFR

2011-10-01

... with the successive changes to the contract price or target profit when— (i) The target profit is changed under a fixed-price incentive contract with successive targets; or (ii) A redetermined price... modification to specify the new rate in the Progress Payments clause. Adequate consideration for these contract...

Analysis of Energy Conservation Alternatives for Standard Army Building

DTIC Science & Technology

1983-03-01

existing system because of the constant cooling and heating required. The fixed set-point with a temperature ecnomizer me, ECIP criteria in the colder... essential to completing other portions of the project. Care must, be taken to ensure that energy savings are not duplicated between projects or portions of

Dilated Canine Hearts: A Specimen for Teaching Cardiac Anatomy

ERIC Educational Resources Information Center

Cope, Lee Anne

2008-01-01

Dilated canine hearts were used to teach undergraduate students internal and external cardiac anatomy. The specimens were dilated using hydrostatic pressure and then fixed using 5% formalin. These specimens provided the students with an alternative to prepackaged embalmed hearts and anatomical models for studying the external and internal cardiac…

Alternatives in Educational Expenditure Policy for the State of Illinois.

ERIC Educational Resources Information Center

Hickrod, G. Alan; Hubbard, Ben C.

This paper (1) provides background on types of State aid to education and describes how they work, (2) discusses the existing expenditure structure in Illinois, (3) describes and analyzes the fixed foundation (Strayer-Haig), variable foundation, percentage equalization, and resource equalizer formulae used for equalization aid in the United…

Progress in lattice gauge theory

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

Creutz, M.

1983-01-01

These lectures first provide an overview of the current status of lattice gauge theory calculations. They then review some technical points on group integration, gauge fixing, and order parameters. Various Monte Carlo algorithms are discussed. Finally, alternatives to the Wilson action are considered in the context of universality for the continuum limit. 41 references.

48 CFR 970.5215-3 - Conditional payment of fee, profit, and other incentives-facility management contracts

Code of Federal Regulations, 2013 CFR

2013-10-01

... period, the DOE Operations/Field Office Manager, or designee, may reduce any otherwise earned fee, fixed... prescribed in 970.1504-5(b)(1), insert the following clause: Conditional Payment of Fee, Profit, and Other Incentives—Facility Management Contracts (AUG 2009) (a) General. (1) The payment of earned fee, fixed fee...

Displacement efficiency of alternative energy and trans-provincial imported electricity in China.

PubMed

Hu, Yuanan; Cheng, Hefa

2017-02-17

China has invested heavily on alternative energy, but the effectiveness of such energy sources at substituting the dominant coal-fired generation remains unknown. Here we analyse the displacement of fossil-fuel-generated electricity by alternative energy, primarily hydropower, and by trans-provincial imported electricity in China between 1995 and 2014 using two-way fixed-effects panel regression models. Nationwide, each unit of alternative energy displaces nearly one-quarter of a unit of fossil-fuel-generated electricity, while each unit of imported electricity (regardless of the generation source) displaces ∼0.3 unit of fossil-fuel electricity generated locally. Results from the six regional grids indicate that significant displacement of fossil-fuel-generated electricity occurs once the share of alternative energy in the electricity supply mix exceeds ∼10%, which is accompanied by 10-50% rebound in the consumption of fossil-fuel-generated electricity. These findings indicate the need for a policy that integrates carbon taxation, alternative energy and energy efficiency to facilitate China's transition towards a low-carbon economy.

Displacement efficiency of alternative energy and trans-provincial imported electricity in China

NASA Astrophysics Data System (ADS)

Hu, Yuanan; Cheng, Hefa

2017-02-01

China has invested heavily on alternative energy, but the effectiveness of such energy sources at substituting the dominant coal-fired generation remains unknown. Here we analyse the displacement of fossil-fuel-generated electricity by alternative energy, primarily hydropower, and by trans-provincial imported electricity in China between 1995 and 2014 using two-way fixed-effects panel regression models. Nationwide, each unit of alternative energy displaces nearly one-quarter of a unit of fossil-fuel-generated electricity, while each unit of imported electricity (regardless of the generation source) displaces ~0.3 unit of fossil-fuel electricity generated locally. Results from the six regional grids indicate that significant displacement of fossil-fuel-generated electricity occurs once the share of alternative energy in the electricity supply mix exceeds ~10%, which is accompanied by 10-50% rebound in the consumption of fossil-fuel-generated electricity. These findings indicate the need for a policy that integrates carbon taxation, alternative energy and energy efficiency to facilitate China's transition towards a low-carbon economy.

Coincident Aerosol and H2O Retrievals versus HSI Imager Field Campaign ReportH2O Retrievals versus HSI Imager Field Campaign Report

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

Anderson, Gail P.; Cipar, John; Armstrong, Peter S.

Two spectrally calibrated tarpaulins (tarps) were co-located at a fixed Global Positioning System (GPS) position on the gravel antenna field at the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s Southern Great Plains (SGP) site. Their placement was timed to coincide with the overflight of a new hyperspectral imaging satellite. The intention was to provide an analysis of the data obtained, including the measured and retrieved spectral albedos for the calibration tarps. Subsequently, a full suite of retrieved values of H2O column, and the aerosol overburden, were to be compared to those determined by alternate SGPmore » ground truth assets. To the extent possible, the down-looking cloud images would be assessed against the all-sky images. Because cloud contamination above a certain level precludes the inversion processing of the satellite data, coupled with infrequent targeting opportunities, clear-sky conditions were imposed. The SGP site was chosen not only as a target of opportunity for satellite validation, but as perhaps the best coincident field measurement site, as established by DOE’s ARM Facility. The satellite team had every expectation of using the information obtained from the SGP to improve the inversion products for all subsequent satellite images, including the cloud and radiative models and parameterizations and, thereby, the performance assessment for subsequent and historic image collections. Coordinating with the SGP onsite team, four visits, all in 2009, to the Central Facility occurred: • June 6-8 (successful exploratory visit to plan tarp placements, etc.) • July 18-24 (canceled because of forecast for heavy clouds) • Sep 9-12 (ground tarps placed, onset of clouds) • Nov 7-9 (visit ultimately canceled because of weather predictions). As noted, in each instance, any significant overcast prediction precluded image collection from the satellite. Given the long task-scheduling procedures (which were in place for each time period), coupled with other priorities and the satellite lifetime, no alternate SGP images could be obtained.« less

Setting the renormalization scale in pQCD: Comparisons of the principle of maximum conformality with the sequential extended Brodsky-Lepage-Mackenzie approach

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

Ma, Hong -Hao; Wu, Xing -Gang; Ma, Yang

A key problem in making precise perturbative QCD (pQCD) predictions is how to set the renormalization scale of the running coupling unambiguously at each finite order. The elimination of the uncertainty in setting the renormalization scale in pQCD will greatly increase the precision of collider tests of the Standard Model and the sensitivity to new phenomena. Renormalization group invariance requires that predictions for observables must also be independent on the choice of the renormalization scheme. The well-known Brodsky-Lepage-Mackenzie (BLM) approach cannot be easily extended beyond next-to-next-to-leading order of pQCD. Several suggestions have been proposed to extend the BLM approach tomore » all orders. In this paper we discuss two distinct methods. One is based on the “Principle of Maximum Conformality” (PMC), which provides a systematic all-orders method to eliminate the scale and scheme ambiguities of pQCD. The PMC extends the BLM procedure to all orders using renormalization group methods; as an outcome, it significantly improves the pQCD convergence by eliminating renormalon divergences. An alternative method is the “sequential extended BLM” (seBLM) approach, which has been primarily designed to improve the convergence of pQCD series. The seBLM, as originally proposed, introduces auxiliary fields and follows the pattern of the β0-expansion to fix the renormalization scale. However, the seBLM requires a recomputation of pQCD amplitudes including the auxiliary fields; due to the limited availability of calculations using these auxiliary fields, the seBLM has only been applied to a few processes at low orders. In order to avoid the complications of adding extra fields, we propose a modified version of seBLM which allows us to apply this method to higher orders. As a result, we then perform detailed numerical comparisons of the two alternative scale-setting approaches by investigating their predictions for the annihilation cross section ratio R e+e– at four-loop order in pQCD.« less

The Effect of External Magnetic Fields on the MRT Instability in MagLIF

NASA Astrophysics Data System (ADS)

Hess, Mark; Peterson, Kyle; Weis, Matthew; Lau, Yue Ying

2014-10-01

Recent experiments on MagLIF which incorporate an external B-field suggest that the MRT instability within the liner has a different behavior than without the B-field. Previous work by Chandrasekhar and Harris have illustrated how the MRT growth rate, assuming fixed liner density and fixed acceleration, can change due to the presence of an external B-field. In this work, we show how the growth rate of the MRT instability is dynamically affected by the rapidly varying acceleration, liner density, and surface magnetic field, which is composed of the external B-field and the drive B-field of the liner in the MagLIF experiments. In addition, we also examine the effects of finite liner resistivity on MRT growth, which gives rise to an additional time scale corresponding to magnetic diffusion. We discuss the implications of this result for future MagLIF designs. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract DE-AC04-94AL85000.

Conversions of formaldehyde-modified 2'-deoxyadenosine 5'-monophosphate in conditions modeling formalin-fixed tissue dehydration.

PubMed

Rait, Vladimir K; Zhang, Qingrong; Fabris, Daniele; Mason, Jeffrey T; O'Leary, Timothy J

2006-03-01

Formalin-fixed, paraffin-embedded specimens typically provide molecular biologists with low yields of extractable nucleic acids that exhibit extensive strand cleavage and covalent modification of nucleic acid bases. This study supports the idea that these deleterious effects are promoted by the first step in formalin-fixed tissue processing--i.e., tissue dehydration with a graded series of alcohols. We analyzed the conversions of formaldehyde-modified 2'-deoxyadenosine 5'-monophosphate (dAMP) by reverse-phase ion-pair, high-performance liquid chromatography and found that dehydration does not stabilize N-methylol groups in the modified nucleotide. Furthermore, spontaneous demodification in a dry state or in anhydrous ethanol can be as fast as it is in aqueous solutions if the preparation is contaminated with salts of orthophosphoric acid. In ethanol, orthophosphates also catalyze formation of abundant N6-ethoxymethyl-dAMP, as well as cross-linking and depurination of nucleotides present in the mixture. Identification of the products was performed using ultraviolet absorbance spectroscopy and electrospray ionization Fourier-transform ion cyclotron resonance mass spectrometry. Alternatives to the traditional processing of formalin-fixed tissues are discussed.

A new cable-tie based sternal closure system: description of the device, technique of implantation and first clinical evaluation

PubMed Central

2012-01-01

Background Wire closure still remains the preferred technique despite reasonable disadvantages. Associated complications, such as infection and sternal instability, cause time- and cost-consuming therapies. We present a new tool for sternal closure with its first clinical experience and results. Methods The sternal ZipFixTM System is based on the cable-tie principle. It primarily consists of biocompatible Poly-Ether-Ether-Ketone implants and is predominantly used peristernally through the intercostal space. The system provides a large implant-to-bone contact for better force distribution and for avoiding bone cut through. Results 50 patients were closed with the ZipFixTM system. No sternal instability was observed at 30 days. Two patients developed a mediastinitis that necessitated the removal of the device; however, the ZipFixTM were intact and the sternum remained stable. Conclusions In our initial evaluation, the short-term results have shown that the sternal ZipFixTM can be used safely and effectively. It is fast, easy to use and serves as a potential alternative for traditional wire closure. PMID:22731778

Effects of AN Alfalfa (medicago Sativa) Buffer Strip on Leached δ15NNITRATE Values: Implications for Management of Hydrologic N Losses

NASA Astrophysics Data System (ADS)

Kelley, C. J.; Keller, C. K.; Smith, J. L.; Evans, R. D.; Harlow, B.

2011-12-01

Buffer strips are commonly used to decrease agricultural runoff with the objective of limiting sediment and agrochemicals fluxes to surface waters. The objective of this study was to determine the effects of an alfalfa buffer strip on the magnitude and source(s) of leached nitrate from a dryland agricultural field. Previous research at the Cook Agronomy Farm has inferred two sources of nitrate in tile drain discharge, a high-discharge-season (January through May) synthetic fertilizer source, and a low-discharge-season (June through December) soil organic nitrogen source. This study examines how a change in management strategy and crop species alters the low discharge season nitrate source. In the spring of 2006 an alfalfa buffer strip approximately 20 m wide was planted running approximately north-south in the lowland portion of a 12 ha tile-drained field bordering a ditch that drains into Missouri Flat Creek. Three-year (2003 through 2005) average NO3--N flux prior to the planting of the alfalfa buffer strip was ~0.40 kg ha-1 year-1. After planting, the three-year (2006 through 2008) average NO3--N flux was ~0.38 kg ha-1 year-1. The lack of evident buffer-strip influence on the fluxes may be due in part to the large variation in precipitation amounts and timing that control water flows through the system. Three-year average δ15Nnitrate values for the tile drain pre and post planting of the alfalfa buffer strip were 6.9 ± 1.1 % and 4.2 ± 0.9 % respectively. We hypothesize that the significant difference indicates that the alfalfa strip affects the source of leached nitrate. Before planting the alfalfa buffer strip, the interpreted source of nitrate was mineralization of soil organic nitrogen from non-N2 fixing crops (spring and summer wheat varieties). After planting the alfalfa buffer strip, the source of nitrate was interpreted to be a mixture of mineralized soil organic nitrogen from N2 fixing alfalfa and non-N2 fixing crops. Further work is needed to test alternative explanations for the observed isotopic shift. This study suggests that the effects of leguminous buffer strips on nutrient fluxes are not simple, and may depend on combinations of hydrologic and pedo-geologic factors.

Gas flow meter and method for measuring gas flow rate

DOEpatents

Robertson, Eric P.

2006-08-01

A gas flow rate meter includes an upstream line and two chambers having substantially equal, fixed volumes. An adjustable valve may direct the gas flow through the upstream line to either of the two chambers. A pressure monitoring device may be configured to prompt valve adjustments, directing the gas flow to an alternate chamber each time a pre-set pressure in the upstream line is reached. A method of measuring the gas flow rate measures the time required for the pressure in the upstream line to reach the pre-set pressure. The volume of the chamber and upstream line are known and fixed, thus the time required for the increase in pressure may be used to determine the flow rate of the gas. Another method of measuring the gas flow rate uses two pressure measurements of a fixed volume, taken at different times, to determine the flow rate of the gas.

Removable partial denture on osseointegrated implants and natural teeth.

PubMed

Chang, Li-Ching; Wang, Jen-Chyan; Tasi, Chi-Cheng

2007-01-01

Implants have been designed to provide edentulous patients with fixed prostheses or overdentures. Recently, implant-supported fixed partial prostheses and single crowns have become successful treatment alternatives to removable and fixed partial dentures. However, few researchers have examined "removable partial dentures on implants and natural teeth". In this article, we report two patients fitted with "removable partial dentures on implants and natural teeth". The patients were satisfied with their dentures in terms of function and aesthetics. Regular follow-up visits revealed that the periodontal and peri-implant conditions were stable. There was no evidence of excessive intrusion or mobility of the teeth, nor were any visible changes in the bone levels of the natural teeth or implants noted on radiographs. Since the average duration of observation was about 38 months, further follow-up examinations are necessary to determine whether these dentures remain stable long-term.

Fixed solar concentrator-collector-satelite receiver and co-generator

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

Meckler, M.

1985-01-01

An insolation and micro wave receiver fixedly installed in alignment with the suns azimuth and within the look angle of a satellite, and comprised of holographic windows recorded according to time related to the suns position as zone plates to concentrate infrared light into a Rankine cycle power generating receiver and to columnate ultraviolet light onto a photo voltaic power generating plane, utilizing a micro wave dish as the substrate support of photo voltaic cells and as a condenser of the Rankine cycle operating an induction generator synchronous with an external alternating current power system, and with the photo voltaicmore » power synchronized therewith by commutation.« less

Stability and Control Properties of an Aeroelastic Fixed Wing Micro Aerial Vehicle

NASA Technical Reports Server (NTRS)

Waszak, Martin R.; Jenkins, Luther N.; Ifju, Peter

2001-01-01

Micro aerial vehicles have been the subject of considerable interest and development over the last several years. The majority of current vehicle concepts rely on rigid fixed wings or rotors. An alternate design based on an aeroelastic membrane wing concept has also been developed that has exhibited desired characteristics in flight test demonstrations and competition. This paper presents results from a wind tunnel investigation that sought to quantify stability and control properties for a family of vehicles using the aeroelastic design. The results indicate that the membrane wing does exhibit potential benefits that could be exploited to enhance the design of future flight vehicles.

Sidewall containment of liquid metal with horizontal alternating magnetic fields

DOEpatents

Praeg, W.F.

1995-01-31

An apparatus is disclosed for confining molten metal with a horizontal alternating magnetic field. In particular, this invention employs a magnet that can produce a horizontal alternating magnetic field to confine a molten metal at the edges of parallel horizontal rollers as a solid metal sheet is cast by counter-rotation of the rollers. 19 figs.

Method of Mapping Anomalies in Homogenous Material

NASA Technical Reports Server (NTRS)

Taylor, Bryant D. (Inventor); Woodard, Stanley E. (Inventor)

2016-01-01

An electrical conductor and antenna are positioned in a fixed relationship to one another. Relative lateral movement is generated between the electrical conductor and a homogenous material while maintaining the electrical conductor at a fixed distance from the homogenous material. The antenna supplies a time-varying magnetic field that causes the electrical conductor to resonate and generate harmonic electric and magnetic field responses. Disruptions in at least one of the electric and magnetic field responses during this lateral movement are indicative of a lateral location of a subsurface anomaly. Next, relative out-of-plane movement is generated between the electrical conductor and the homogenous material in the vicinity of the anomaly's lateral location. Disruptions in at least one of the electric and magnetic field responses during this out-of-plane movement are indicative of a depth location of the subsurface anomaly. A recording of the disruptions provides a mapping of the anomaly.

Phase seeding of a terahertz quantum cascade laser

PubMed Central

Oustinov, Dimitri; Jukam, Nathan; Rungsawang, Rakchanok; Madéo, Julien; Barbieri, Stefano; Filloux, Pascal; Sirtori, Carlo; Marcadet, Xavier; Tignon, Jérôme; Dhillon, Sukhdeep

2010-01-01

The amplification of spontaneous emission is used to initiate laser action. As the phase of spontaneous emission is random, the phase of the coherent laser emission (the carrier phase) will also be random each time laser action begins. This prevents phase-resolved detection of the laser field. Here, we demonstrate how the carrier phase can be fixed in a semiconductor laser: a quantum cascade laser (QCL). This is performed by injection seeding a QCL with coherent terahertz pulses, which forces laser action to start on a fixed phase. This permits the emitted laser field to be synchronously sampled with a femtosecond laser beam, and measured in the time domain. We observe the phase-resolved buildup of the laser field, which can give insights into the laser dynamics. In addition, as the electric field oscillations are directly measured in the time domain, QCLs can now be used as sources for time-domain spectroscopy. PMID:20842195

Evaluation of Electromechanical Systems Dynamically Emulating a Candidate Hydrokinetic Turbine

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

Cavagnaro, Robert J.; Neely, Jason C.; Fay, Franois-Xavier

The use of controllable motor-generator sets to emulate the dynamics of a hydrokinetic turbine is evaluated as an alternative to field testing a prototype. The emulator control dynamic equations are presented, methods for scaling turbine parameters are examined, and experimental results are presented from three electromechanical emulation machines (EEMs) programmed to emulate the same vertical-axis fixed-pitch turbine. Although hardware platforms and control implementations varied, results show that each EEM is successful in emulating the turbine model, thus demonstrating the general feasibility of the approach. However, performance of motor control under torque command, current command or speed command differed. In onemore » of the EEMs evaluated, the power take off controller tracks the maximum power-point of the turbine in response to turbulence. Utilizing realistic inflow conditions and control laws, the emulator dynamic speed response is shown to agree well at low frequencies with numerical simulation but to deviate at high frequencies.« less

The effect of the magnetic nanoparticle's size dependence of the relaxation time constant on the specific loss power of magnetic nanoparticle hyperthermia

NASA Astrophysics Data System (ADS)

Harabech, Mariem; Leliaert, Jonathan; Coene, Annelies; Crevecoeur, Guillaume; Van Roost, Dirk; Dupré, Luc

2017-03-01

Magnetic nanoparticle hyperthermia is a cancer treatment in which magnetic nanoparticles (MNPs) are subjected to an alternating magnetic field to induce heat in the tumor. The generated heat of MNPs is characterized by the specific loss power (SLP) due to relaxation phenomena of the MNP. Up to now, several models have been proposed to predict the SLP, one of which is the Linear Response Theory. One parameter in this model is the relaxation time constant. In this contribution, we employ a macrospin model based on the Landau-Lifshitz-Gilbert equation to investigate the relation between the Gilbert damping parameter and the relaxation time constant. This relaxation time has a pre-factor τ0 which is often taken as a fixed value ranging between 10-8 and 10-12 s. However, in reality it has small size dependence. Here, the influence of this size dependence on the calculation of the SLP is demonstrated, consequently improving the accuracy of this estimate.

Alternative definitions of the frozen energy in energy decomposition analysis of density functional theory calculations.

PubMed

Horn, Paul R; Head-Gordon, Martin

2016-02-28

In energy decomposition analysis (EDA) of intermolecular interactions calculated via density functional theory, the initial supersystem wavefunction defines the so-called "frozen energy" including contributions such as permanent electrostatics, steric repulsions, and dispersion. This work explores the consequences of the choices that must be made to define the frozen energy. The critical choice is whether the energy should be minimized subject to the constraint of fixed density. Numerical results for Ne2, (H2O)2, BH3-NH3, and ethane dissociation show that there can be a large energy lowering associated with constant density orbital relaxation. By far the most important contribution is constant density inter-fragment relaxation, corresponding to charge transfer (CT). This is unwanted in an EDA that attempts to separate CT effects, but it may be useful in other contexts such as force field development. An algorithm is presented for minimizing single determinant energies at constant density both with and without CT by employing a penalty function that approximately enforces the density constraint.

Evaluation of Electromechanical Systems Dynamically Emulating a Candidate Hydrokinetic Turbine

DOE PAGES

Cavagnaro, Robert J.; Neely, Jason C.; Fay, Franois-Xavier; ...

2016-11-06

The use of controllable motor-generator sets to emulate the dynamics of a hydrokinetic turbine is evaluated as an alternative to field testing a prototype. The emulator control dynamic equations are presented, methods for scaling turbine parameters are examined, and experimental results are presented from three electromechanical emulation machines (EEMs) programmed to emulate the same vertical-axis fixed-pitch turbine. Although hardware platforms and control implementations varied, results show that each EEM is successful in emulating the turbine model, thus demonstrating the general feasibility of the approach. However, performance of motor control under torque command, current command or speed command differed. In onemore » of the EEMs evaluated, the power take off controller tracks the maximum power-point of the turbine in response to turbulence. Utilizing realistic inflow conditions and control laws, the emulator dynamic speed response is shown to agree well at low frequencies with numerical simulation but to deviate at high frequencies.« less

Extension of a three-dimensional viscous wing flow analysis

NASA Technical Reports Server (NTRS)

Weinberg, Bernard C.; Chen, Shyi-Yaung; Thoren, Stephen J.; Shamroth, Stephen J.

1990-01-01

Three-dimensional unsteady viscous effects can significantly influence the performance of fixed and rotary wing aircraft. These effects are important in both flows about helicopter rotors in forward flight and flows about 3-D (swept and tapered) supercritical wings. A computational procedure for calculating such flow field is developed, and therefore would be of great value in the design process as well as in understanding the corresponding flow phenomena. The procedure is based upon an alternating direction technique employing the Linearized Block Implicit method for solving 3-D viscous flow problems. In order to demonstrate the viability of this method, 2-D and 3-D problems are computed. These include the flow over a 2-D NACA 0012 airfoil under steady and oscillating conditions, and the steady, skewed, 3-D flow on a flat plate. Although actual 3-D flows over wings were not obtained, the ground work was laid for considering such flows. The description of the computational procedure and results are given.

Neural circuits. Labeling of active neural circuits in vivo with designed calcium integrators.

PubMed

Fosque, Benjamin F; Sun, Yi; Dana, Hod; Yang, Chao-Tsung; Ohyama, Tomoko; Tadross, Michael R; Patel, Ronak; Zlatic, Marta; Kim, Douglas S; Ahrens, Misha B; Jayaraman, Vivek; Looger, Loren L; Schreiter, Eric R

2015-02-13

The identification of active neurons and circuits in vivo is a fundamental challenge in understanding the neural basis of behavior. Genetically encoded calcium (Ca(2+)) indicators (GECIs) enable quantitative monitoring of cellular-resolution activity during behavior. However, such indicators require online monitoring within a limited field of view. Alternatively, post hoc staining of immediate early genes (IEGs) indicates highly active cells within the entire brain, albeit with poor temporal resolution. We designed a fluorescent sensor, CaMPARI, that combines the genetic targetability and quantitative link to neural activity of GECIs with the permanent, large-scale labeling of IEGs, allowing a temporally precise "activity snapshot" of a large tissue volume. CaMPARI undergoes efficient and irreversible green-to-red conversion only when elevated intracellular Ca(2+) and experimenter-controlled illumination coincide. We demonstrate the utility of CaMPARI in freely moving larvae of zebrafish and flies, and in head-fixed mice and adult flies. Copyright © 2015, American Association for the Advancement of Science.

Evaluation of formalin-fixed paraffin-embedded tissues in the proteomic analysis of parathyroid glands

PubMed Central

2011-01-01

Background Proteomic research in the field of parathyroid tissues is limited by the very small dimension of the glands and by the low incidence of cancer lesions (1%). Formalin-fixed paraffin-embedded (FFPE) tissue specimens are a potentially valuable resource for discovering protein cancer biomarkers. In this study we have verified the applicability of a heat induced protein extraction from FFPE parathyroid adenoma tissues followed by a gel-based or gel-free proteomic approach in order to achieve protein separation and identification. Results The best results for high quality MS spectra and parameters, were obtained by using a gel-free approach, and up to 163 unique proteins were identified. Similar results were obtained by applying both SDS-out and SDS-out + TCA/Acetone techniques during the gel-free method. Western blot analysis carried out with specific antibodies suggested that the antigenicity was not always preserved, while specific immunoreactions were detected for calmodulin, B box and SPRY domain-containing protein (BSPRY), peroxiredoxin 6 (PRDX 6) and parvalbumin. Conclusions In spite of some limitations mainly due to the extensive formalin-induced covalent cross-linking, our results essentially suggest the applicability of a proteomic approach to FFPE parathyroid specimens. From our point of view, FFPE extracts might be an alternative source, especially in the validation phase of protein biomarkers when a large cohort of samples is required and the low availability of frozen tissues might be constraining. PMID:21651755

Random phase detection in multidimensional NMR.

PubMed

Maciejewski, Mark W; Fenwick, Matthew; Schuyler, Adam D; Stern, Alan S; Gorbatyuk, Vitaliy; Hoch, Jeffrey C

2011-10-04

Despite advances in resolution accompanying the development of high-field superconducting magnets, biomolecular applications of NMR require multiple dimensions in order to resolve individual resonances, and the achievable resolution is typically limited by practical constraints on measuring time. In addition to the need for measuring long evolution times to obtain high resolution, the need to distinguish the sign of the frequency constrains the ability to shorten measuring times. Sign discrimination is typically accomplished by sampling the signal with two different receiver phases or by selecting a reference frequency outside the range of frequencies spanned by the signal and then sampling at a higher rate. In the parametrically sampled (indirect) time dimensions of multidimensional NMR experiments, either method imposes an additional factor of 2 sampling burden for each dimension. We demonstrate that by using a single detector phase at each time sample point, but randomly altering the phase for different points, the sign ambiguity that attends fixed single-phase detection is resolved. Random phase detection enables a reduction in experiment time by a factor of 2 for each indirect dimension, amounting to a factor of 8 for a four-dimensional experiment, albeit at the cost of introducing sampling artifacts. Alternatively, for fixed measuring time, random phase detection can be used to double resolution in each indirect dimension. Random phase detection is complementary to nonuniform sampling methods, and their combination offers the potential for additional benefits. In addition to applications in biomolecular NMR, random phase detection could be useful in magnetic resonance imaging and other signal processing contexts.

Wall shear stress fixed points in cardiovascular fluid mechanics.

PubMed

Arzani, Amirhossein; Shadden, Shawn C

2018-05-17

Complex blood flow in large arteries creates rich wall shear stress (WSS) vectorial features. WSS acts as a link between blood flow dynamics and the biology of various cardiovascular diseases. WSS has been of great interest in a wide range of studies and has been the most popular measure to correlate blood flow to cardiovascular disease. Recent studies have emphasized different vectorial features of WSS. However, fixed points in the WSS vector field have not received much attention. A WSS fixed point is a point on the vessel wall where the WSS vector vanishes. In this article, WSS fixed points are classified and the aspects by which they could influence cardiovascular disease are reviewed. First, the connection between WSS fixed points and the flow topology away from the vessel wall is discussed. Second, the potential role of time-averaged WSS fixed points in biochemical mass transport is demonstrated using the recent concept of Lagrangian WSS structures. Finally, simple measures are proposed to quantify the exposure of the endothelial cells to WSS fixed points. Examples from various arterial flow applications are demonstrated. Copyright © 2018 Elsevier Ltd. All rights reserved.

Some remarks on the attractor behaviour in ELKO cosmology

NASA Astrophysics Data System (ADS)

Pereira, S. H.; A. Pinho S., S.; Hoff da Silva, J. M.

2014-08-01

Recent results on the dynamical stability of a system involving the interaction of the ELKO spinor field with standard matter in the universe have been reanalysed, and the conclusion is that such system does not exhibit isolated stable points that could alleviate the cosmic coincidence problem. When a constant parameter δ related to the potential of the ELKO field is introduced in the system however, stable fixed points are found for some specific types of interaction between the ELKO field and matter. Although the parameter δ is related to an unknown potential, in order to satisfy the stability conditions and also that the fixed points are real, the range of the constant parameter δ can be constrained for the present time and the coincidence problem can be alleviated for some specific interactions. Such restriction on the ELKO potential opens possibility to apply the ELKO field as a candidate to dark energy in the universe, and so explain the present phase of acceleration of the universe through the decay of the ELKO field into matter.

New Phenomena in NC Field Theory and Emergent Spacetime Geometry

NASA Astrophysics Data System (ADS)

Ydri, Badis

2010-10-01

We give a brief review of two nonperturbative phenomena typical of noncommutative field theory which are known to lead to the perturbative instability known as the UV-IR mixing. The first phenomena concerns the emergence/evaporation of spacetime geometry in matrix models which describe perturbative noncommutative gauge theory on fuzzy backgrounds. In particular we show that the transition from a geometrical background to a matrix phase makes the description of noncommutative gauge theory in terms of fields via the Weyl map only valid below a critical value g*. The second phenomena concerns the appearance of a nonuniform ordered phase in noncommutative scalar φ4 field theory and the spontaneous symmetry breaking of translational/rotational invariance which happens even in two dimensions. We argue that this phenomena also originates in the underlying matrix degrees of freedom of the noncommutative field theory. Furthermore it is conjectured that in addition to the usual WF fixed point at θ = 0 there must exist a novel fixed point at θ = ∞ corresponding to the quartic hermitian matrix model.

Ultrasonic Phased Array Sound Field Mapping Through Large-Bore Coarse Grained Cast Austenitic Stainless Steel (CASS) Piping Materials

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

Cinson, Anthony D.; Crawford, Susan L.; Prowant, Matthew S.

2012-04-16

A sound field beam mapping exercise was conducted to further understand the effects of coarse grained microstructures found in CASS materials on phased array ultrasonic wave propagation. Laboratory measurements were made on three CASS specimens with different microstructures; the specimens were polished and etched to reveal measurable grain sizes, shapes and orientations. Three longitudinal, phased array probes were fixed on a specimen's outside diameter with the sound field directed toward one end (face) of the pipe segment over a fixed range of angles. A point receiver was raster scanned over the surface of the specimen face generating a sound fieldmore » image. A slice of CASS material was then removed from the specimen end and the beam mapping exercise repeated. The sound fields acquired were analyzed for spot size, coherency, and beam redirection. Analyses were conducted between the resulting sound fields and the microstructural characteristics of each specimen.« less

Wastewater treatment with submerged fixed bed biofilm reactor systems--design rules, operating experiences and ongoing developments.

PubMed

Schlegel, S; Koeser, H

2007-01-01

Wastewater treatment systems using bio-films that grow attached to a support media are an alternative to the widely used suspended growth activated sludge process. Different fixed growth biofilm reactors are commercially used for the treatment of municipal as well as industrial wastewater. In this paper a fairly new fixed growth biofilm system, the submerged fixed bed biofilm reactor (SFBBR), is discussed. SFBBRs are based on aerated submerged fixed open structured plastic media for the support of the biofilm. They are generally operated without sludge recirculation in order to avoid clogging of the support media and problems with the control of the biofilm. Reactor and process design considerations for these reactors are reviewed. Measures to ensure the development and maintenance of an active biofilm are examined. SFBBRs have been applied successfully to small wastewater treatment plants where complete nitrification but no high degree of denitrification is necessary. For the pre-treatment of industrial wastewater the use of SFBBRs is advantageous, especially in cases of wastewater with high organic loading or high content of compounds with low biodegradability. Performance data from exemplary commercial plants are given. Ongoing research and development efforts aim at achieving a high simultaneous total nitrogen (TN) removal of aerated SFBBRs and at improving the efficiency of TN removal in anoxic SFBBRs.

Inflation, quintessence, and the origin of mass

NASA Astrophysics Data System (ADS)

Wetterich, C.

2015-08-01

In a unified picture both inflation and present dynamical dark energy arise from the same scalar field. The history of the Universe describes a crossover from a scale invariant "past fixed point" where all particles are massless, to a "future fixed point" for which spontaneous breaking of the exact scale symmetry generates the particle masses. The cosmological solution can be extrapolated to the infinite past in physical time - the universe has no beginning. This is seen most easily in a frame where particle masses and the Planck mass are field-dependent and increase with time. In this "freeze frame" the Universe shrinks and heats up during radiation and matter domination. In the equivalent, but singular Einstein frame cosmic history finds the familiar big bang description. The vicinity of the past fixed point corresponds to inflation. It ends at a first stage of the crossover. A simple model with no more free parameters than ΛCDM predicts for the primordial fluctuations a relation between the tensor amplitude r and the spectral index n, r = 8.19 (1 - n) - 0.137. The crossover is completed by a second stage where the beyond-standard-model sector undergoes the transition to the future fixed point. The resulting increase of neutrino masses stops a cosmological scaling solution, relating the present dark energy density to the present neutrino mass. At present our simple model seems compatible with all observational tests. We discuss how the fixed points can be rooted within quantum gravity in a crossover between ultraviolet and infrared fixed points. Then quantum properties of gravity could be tested both by very early and late cosmology.

Holographic entanglement chemistry

NASA Astrophysics Data System (ADS)

Caceres, Elena; Nguyen, Phuc H.; Pedraza, Juan F.

2017-05-01

We use the Iyer-Wald formalism to derive an extended first law of entanglement that includes variations in the cosmological constant, Newton's constant and—in the case of higher-derivative theories—all the additional couplings of the theory. In Einstein gravity, where the number of degrees of freedom N2 of the dual field theory is a function of Λ and G , our approach allows us to vary N by keeping the field theory scale fixed or to vary the field theory scale by keeping N fixed. We also derive an extended first law of entanglement for Gauss-Bonnet and Lovelock gravity and show that in these cases all the extra variations reorganize nicely in terms of the central charges of the theory. Finally, we comment on the implications for renormalization group flows and c -theorems in higher dimensions.

Tailoring treatment of haemophilia B: accounting for the distribution and clearance of standard and extended half-life FIX concentrates.

PubMed

Iorio, Alfonso; Fischer, Kathelijn; Blanchette, Victor; Rangarajan, Savita; Young, Guy; Morfini, Massimo

2017-06-02

The prophylactic administration of factor IX (FIX) is considered the most effective treatment for haemophilia B. The inter-individual variability and complexity of the pharmacokinetics (PK) of FIX, and the rarity of the disease have hampered identification of an optimal treatment regimens. The recent introduction of extended half-life recombinant FIX molecules (EHL-rFIX), has prompted a thorough reassessment of the clinical efficacy, PK and pharmacodynamics of plasma-derived and recombinant FIX. First, using longer sampling times and multi-compartmental PK models has led to more precise (and favourable) PK for FIX than was appreciated in the past. Second, investigating the distribution of FIX in the body beyond the vascular space (which is implied by its complex kinetics) has opened a new research field on the role for extravascular FIX. Third, measuring plasma levels of EHL-rFIX has shown that different aPTT reagents have different accuracy in measuring different FIX molecules. How will this new knowledge reflect on clinical practice? Clinical decision making in haemophilia B requires some caution and expertise. First, comparisons between different FIX molecules must be assessed taking into consideration the comparability of the populations studied and the PK models used. Second, individual PK estimates must rely on multi-compartmental models, and would benefit from adopting a population PK approach. Optimal sampling times need to be adapted to the prolonged half-life of the new EHL FIX products. Finally, costs considerations may apply, which is beyond the scope of this manuscript but might be deeply connected with the PK considerations discussed in this communication.

Simulation of the fixed optical path difference of near infrared wind imaging interferometer

NASA Astrophysics Data System (ADS)

Rong, Piao; Zhang, Chunmin; Yan, Tingyu; Liu, Dongdong; Li, Yanfen

2017-02-01

As an important part of the earth, atmosphere plays a vital role in filtering the solar radiation, adjusting the temperature and organizing the water circulation and keeping human survival. The passive atmospheric wind measurement is based on the imaging interferometer technology and Doppler effect of electromagnetic wave. By using the wind imaging interferometer to get four interferograms of airglow emission lines, the atmospheric wind velocity, temperature, pressure and emission rate can be derived. Exploring the multi-functional and integrated innovation of detecting wind temperature, wind velocity and trace gas has become a research focus in the field. In the present paper, the impact factors of the fixed optical path difference(OPD) of near infrared wind imaging interferometer(NIWII) are analyzed and the optimum value of the fixed optical path difference is simulated, yielding the optimal results of the fixed optical path difference is 20 cm in near infrared wave band (the O2(a1Δg) airglow emission at 1.27 microns). This study aims at providing theoretical basis and technical support for the detection of stratosphere near infrared wind field and giving guidance for the design and development of near infrared wind imaging interferometer.

Physical stress, mass, and energy for non-relativistic matter

NASA Astrophysics Data System (ADS)

Geracie, Michael; Prabhu, Kartik; Roberts, Matthew M.

2017-06-01

For theories of relativistic matter fields there exist two possible definitions of the stress-energy tensor, one defined by a variation of the action with the coframes at fixed connection, and the other at fixed torsion. These two stress-energy tensors do not necessarily coincide and it is the latter that corresponds to the Cauchy stress measured in the lab. In this note we discuss the corresponding issue for non-relativistic matter theories. We point out that while the physical non-relativistic stress, momentum, and mass currents are defined by a variation of the action at fixed torsion, the energy current does not admit such a description and is naturally defined at fixed connection. Any attempt to define an energy current at fixed torsion results in an ambiguity which cannot be resolved from the background spacetime data or conservation laws. We also provide computations of these quantities for some simple non-relativistic actions.

Inflation with a massive vector field nonminimally coupled to gravity

NASA Astrophysics Data System (ADS)

Páramos, J.

2018-01-01

The possibility that inflation is driven by a massive vector field with SO(3) global symmetry nonminimally coupled to gravity is presented. Through an appropriate Ansatz for the vector field, the behaviour of the equations of motion is studied through the ensuing dynamical system, focusing on the characterisation of the ensuing fixed points.

47 CFR 22.602 - Transition of the 2110-2130 and 2160-2180 MHz channels to emerging technologies.

Code of Federal Regulations, 2011 CFR

2011-10-01

... other microwave bands, authorization must be obtained under part 101 of this chapter. (a) Licensees... to other fixed microwave bands or other media, or alternatively, (2) Accept a sharing arrangement... will have a three-year mandatory negotiation period. (d) The mandatory negotiation period is triggered...

47 CFR 22.602 - Transition of the 2110-2130 and 2160-2180 MHz channels to emerging technologies.

Code of Federal Regulations, 2013 CFR

2013-10-01

... other microwave bands, authorization must be obtained under part 101 of this chapter. (a) Licensees... to other fixed microwave bands or other media, or alternatively, (2) Accept a sharing arrangement... will have a three-year mandatory negotiation period. (d) The mandatory negotiation period is triggered...

47 CFR 22.602 - Transition of the 2110-2130 and 2160-2180 MHz channels to emerging technologies.

Code of Federal Regulations, 2014 CFR

2014-10-01

... other microwave bands, authorization must be obtained under part 101 of this chapter. (a) Licensees... to other fixed microwave bands or other media, or alternatively, (2) Accept a sharing arrangement... will have a three-year mandatory negotiation period. (d) The mandatory negotiation period is triggered...

47 CFR 22.602 - Transition of the 2110-2130 and 2160-2180 MHz channels to emerging technologies.

Code of Federal Regulations, 2012 CFR

2012-10-01

... other microwave bands, authorization must be obtained under part 101 of this chapter. (a) Licensees... to other fixed microwave bands or other media, or alternatively, (2) Accept a sharing arrangement... will have a three-year mandatory negotiation period. (d) The mandatory negotiation period is triggered...

Children First: An Alternative Approach to Assessment (The Brian Simon Memorial Lecture 2015)

ERIC Educational Resources Information Center

Peacock, Alison

2016-01-01

The author discusses the importance of listening to children and engaging them in dialogue about their learning. She does not accept that assessment should entail labelling children and believes such practices encourage a culture of fixed "ability" thinking. Through examples of specific children, the author illustrates the importance of…

Bayesian Model Comparison for the Order Restricted RC Association Model

ERIC Educational Resources Information Center

Iliopoulos, G.; Kateri, M.; Ntzoufras, I.

2009-01-01

Association models constitute an attractive alternative to the usual log-linear models for modeling the dependence between classification variables. They impose special structure on the underlying association by assigning scores on the levels of each classification variable, which can be fixed or parametric. Under the general row-column (RC)…

An Alternating Least Squares Method for the Weighted Approximation of a Symmetric Matrix.

ERIC Educational Resources Information Center

ten Berge, Jos M. F.; Kiers, Henk A. L.

1993-01-01

R. A. Bailey and J. C. Gower explored approximating a symmetric matrix "B" by another, "C," in the least squares sense when the squared discrepancies for diagonal elements receive specific nonunit weights. A solution is proposed where "C" is constrained to be positive semidefinite and of a fixed rank. (SLD)

Preparation for implementation of the mechanistic-empirical pavement design guide in Michigan : part 2 - evaluation of rehabilitation fixes (part 1).

DOT National Transportation Integrated Search

2013-08-01

The main objectives of Task 2 of the project were to determine the impact of various input variables on the predicted pavement performance for the selected rehabilitation design alternatives in the MEPDG/DARWin-ME, and to verify the pavement performa...

Online Kiosks: The Alternative to Mobile Technologies for Mobile Users.

ERIC Educational Resources Information Center

Slack, Frances; Rowley, Jennifer

2002-01-01

Describes the development and use of online kiosks in contexts where users are away from fixed technologies. Uses a case study of a United Kingdom airport terminal to illustrate different types of kiosk applications; makes comparisons with mobile phone technologies; and considers their role in self-managed, self-service delivery of information and…

Environmental damage schedules: community judgments of importance and assessments of losses

Treesearch

Ratana Chuenpagdee; Jack L. Knetsch; Thomas C. Brown

2001-01-01

Available methods of valuing environmental changes are often limited in their applicability to current issues such as damage assessment and implementing regulatory controls, or may otherwise not provide reliable readings of community preferences. An alternative is to base decisions on predetermined fixed schedules of sanctions, restrictions, damage awards, and other...

Evaluation of Moving Object Detection Based on Various Input Noise Using Fixed Camera

NASA Astrophysics Data System (ADS)

Kiaee, N.; Hashemizadeh, E.; Zarrinpanjeh, N.

2017-09-01

Detecting and tracking objects in video has been as a research area of interest in the field of image processing and computer vision. This paper evaluates the performance of a novel method for object detection algorithm in video sequences. This process helps us to know the advantage of this method which is being used. The proposed framework compares the correct and wrong detection percentage of this algorithm. This method was evaluated with the collected data in the field of urban transport which include car and pedestrian in fixed camera situation. The results show that the accuracy of the algorithm will decreases because of image resolution reduction.

Two-axis magnetic field sensor

NASA Technical Reports Server (NTRS)

Smith, Carl H. (Inventor); Nordman, Catherine A. (Inventor); Jander, Albrecht (Inventor); Qian, Zhenghong (Inventor)

2006-01-01

A ferromagnetic thin-film based magnetic field sensor with first and second sensitive direction sensing structures each having a nonmagnetic intermediate layer with two major surfaces on opposite sides thereof having a magnetization reference layer on one and an anisotropic ferromagnetic material sensing layer on the other having a length in a selected length direction and a smaller width perpendicular thereto and parallel to the relatively fixed magnetization direction. The relatively fixed magnetization direction of said magnetization reference layer in each is oriented in substantially parallel to the substrate but substantially perpendicular to that of the other. An annealing process is used to form the desired magnetization directions.

Flow interaction and noise from a counter rotating propeller

NASA Technical Reports Server (NTRS)

Chung, Jin-Deog; Walls, James L.; Nagel, Robert T.

1991-01-01

The aerodynamic interaction between the forward and rear rotors in a counter rotating propeller (CRP) system, has been examined using a conditional sampling technique applied to three-dimensional thermal anemometer data. The technique effectively freezes the rotors in any desired relative position and provides the inter-rotor flow field. Axial, radial and circumferential mean flow between rotors is shown relative to the 'fixed' forward rotor for various 'fixed' aft rotor positions. Acoustic far field noise data have also been collected for the same operating conditions. The acoustic results are presented with emphasis on the blade passing frequencies and interaction tone of the CRP.

Recording Field Potentials From Zebrafish Larvae During Escape Responses

PubMed Central

Monesson-Olson, Bryan D.; Troconis, Eileen L.; Trapani, Josef G.

2014-01-01

Among vertebrates, startle responses are a ubiquitous method for alerting, and avoiding or escaping from alarming or dangerous stimuli. In zebrafish larvae, fast escape behavior is easily evoked through either acoustic or tactile stimuli. For example, a light touch to the head will excite trigeminal neurons that in turn excite a large reticulospinal neuron in the hindbrain called the Mauthner cell (M-cell). The M-cell action potential then travels down the contralateral trunk of the larva exciting motoneurons, which subsequently excite the entire axial musculature, producing a large amplitude body bend away from the source of the stimulus. This body conformation is known as the “C-bend” due to the shape of the larva during the behavior. As a result of the semi-synchronized activation of the M-cell, the population of motor neurons, and the axial trunk muscles, a large field potential is generated and can be recorded from free-swimming or fixed-position larvae. Undergraduate laboratories that record field potentials during escape responses in larval zebrafish are relatively simple to setup and allow students to observe and study the escape reflex circuit. Furthermore, by testing hypotheses, analyzing data and writing journal-style laboratory reports, students have multiple opportunities to learn about many neuroscience topics including vertebrate reflexes; sensory transduction; synaptic-, neuro-, and muscle-physiology; the M-cell mediated escape response; and the zebrafish as a model organism. Here, we detail the equipment, software, and recording setup necessary to observe field potentials in an undergraduate teaching lab. Additionally, we discuss potential advanced laboratory exercises and pedagogical outcomes. Finally, we note possible low-cost alternatives for recording field potentials. PMID:25565920

Competing exchange interactions in multiferroic and ferrimagnetic CaBaCo 4 O 7

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

Fishman, Randy Scott; Bordacs, S.; Kocsis, Vilmos

Competing exchange interactions can produce complex magnetic states together with spin-induced electric polarizations. With competing interactions on alternating triangular and kagome layers, the swedenborgite CaBaCo 4O 7 may have one of the largest measured spin-induced polarizations of ~1700 nC/cm 2 below its ferrimagnetic transition temperature at 70 K. Upon rotating our sample about c = [0,0,1] while the magnetic field is fixed along [1,0,0], the threefold splitting of the spin-wave frequencies indicates that our sample is hexagonally twinned. In addition, magnetization measurements then suggest that roughly 20% of the sample is in a domain with the a axis along [1,0,0]more » and that 80% of the sample is in one of two other domains with the a axis along either [-1/2,√3/2, 0] or [-1/2, -√3/2, 0] . Powder neutron-diffraction data, magnetization measurements, and terahertz (THz) absorption spectroscopy reveal that the complex spin order in each domain can be described as a triangular array of bitetrahedral c-axis chains ferrimagnetically coupled to each other in the ab plane. In conclusion, the electric-field dependence of bonds coupling those chains produces the large spin-induced polarization of CaBaCo 4O 7 .« less

Competing exchange interactions in multiferroic and ferrimagnetic CaBaCo 4 O 7

DOE PAGES

Fishman, Randy Scott; Bordacs, S.; Kocsis, Vilmos; ...

2017-01-23

Competing exchange interactions can produce complex magnetic states together with spin-induced electric polarizations. With competing interactions on alternating triangular and kagome layers, the swedenborgite CaBaCo 4O 7 may have one of the largest measured spin-induced polarizations of ~1700 nC/cm 2 below its ferrimagnetic transition temperature at 70 K. Upon rotating our sample about c = [0,0,1] while the magnetic field is fixed along [1,0,0], the threefold splitting of the spin-wave frequencies indicates that our sample is hexagonally twinned. In addition, magnetization measurements then suggest that roughly 20% of the sample is in a domain with the a axis along [1,0,0]more » and that 80% of the sample is in one of two other domains with the a axis along either [-1/2,√3/2, 0] or [-1/2, -√3/2, 0] . Powder neutron-diffraction data, magnetization measurements, and terahertz (THz) absorption spectroscopy reveal that the complex spin order in each domain can be described as a triangular array of bitetrahedral c-axis chains ferrimagnetically coupled to each other in the ab plane. In conclusion, the electric-field dependence of bonds coupling those chains produces the large spin-induced polarization of CaBaCo 4O 7 .« less

Tidal and tidally averaged circulation characteristics of Suisun Bay, California

USGS Publications Warehouse

Smith, Lawrence H.; Cheng, Ralph T.

1987-01-01

Availability of extensive field data permitted realistic calibration and validation of a hydrodynamic model of tidal circulation and salt transport for Suisun Bay, California. Suisun Bay is a partially mixed embayment of northern San Francisco Bay located just seaward of the Sacramento-San Joaquin Delta. The model employs a variant of an alternating direction implicit finite-difference method to solve the hydrodynamic equations and an Eulerian-Lagrangian method to solve the salt transport equation. An upwind formulation of the advective acceleration terms of the momentum equations was employed to avoid oscillations in the tidally averaged velocity field produced by central spatial differencing of these terms. Simulation results of tidal circulation and salt transport demonstrate that tides and the complex bathymetry determine the patterns of tidal velocities and that net changes in the salinity distribution over a few tidal cycles are small despite large changes during each tidal cycle. Computations of tidally averaged circulation suggest that baroclinic and wind effects are important influences on tidally averaged circulation during low freshwater-inflow conditions. Exclusion of baroclinic effects would lead to overestimation of freshwater inflow by several hundred m3/s for a fixed set of model boundary conditions. Likewise, exclusion of wind would cause an underestimation of flux rates between shoals and channels by 70–100%.

General Series Solutions for Stresses and Displacements in an Inner-fixed Ring

NASA Astrophysics Data System (ADS)

Jiao, Yongshu; Liu, Shuo; Qi, Dexuan

2018-03-01

The general series solution approach is provided to get the stress and displacement fields in the inner-fixed ring. After choosing an Airy stress function in series form, stresses are expressed by infinite coefficients. Displacements are obtained by integrating the geometric equations. For an inner-fixed ring, the arbitrary loads acting on outer edge are extended into two sets of Fourier series. The zero displacement boundary conditions on inner surface are utilized. Then the stress (and displacement) coefficients are expressed by loading coefficients. A numerical example shows the validity of this approach.

Low power multi-camera system and algorithms for automated threat detection

NASA Astrophysics Data System (ADS)

Huber, David J.; Khosla, Deepak; Chen, Yang; Van Buer, Darrel J.; Martin, Kevin

2013-05-01

A key to any robust automated surveillance system is continuous, wide field-of-view sensor coverage and high accuracy target detection algorithms. Newer systems typically employ an array of multiple fixed cameras that provide individual data streams, each of which is managed by its own processor. This array can continuously capture the entire field of view, but collecting all the data and back-end detection algorithm consumes additional power and increases the size, weight, and power (SWaP) of the package. This is often unacceptable, as many potential surveillance applications have strict system SWaP requirements. This paper describes a wide field-of-view video system that employs multiple fixed cameras and exhibits low SWaP without compromising the target detection rate. We cycle through the sensors, fetch a fixed number of frames, and process them through a modified target detection algorithm. During this time, the other sensors remain powered-down, which reduces the required hardware and power consumption of the system. We show that the resulting gaps in coverage and irregular frame rate do not affect the detection accuracy of the underlying algorithms. This reduces the power of an N-camera system by up to approximately N-fold compared to the baseline normal operation. This work was applied to Phase 2 of DARPA Cognitive Technology Threat Warning System (CT2WS) program and used during field testing.

The effect of budesonide/formoterol maintenance and reliever therapy on the risk of severe asthma exacerbations following episodes of high reliever use: an exploratory analysis of two randomised, controlled studies with comparisons to standard therapy

PubMed Central

2012-01-01

Background Divergent strategies have emerged for the management of severe asthma. One strategy utilises high and fixed doses of maintenance treatment, usually inhaled corticosteroid/long-acting β2-agonist (ICS/LABA), supplemented by a short-acting β2-agonist (SABA) as needed. Alternatively, budesonide/formoterol is used as both maintenance and reliever therapy. The latter is superior to fixed-dose treatment in reducing severe exacerbations while achieving similar or better asthma control in other regards. Exacerbations may be reduced by the use of budesonide/formoterol as reliever medication during periods of unstable asthma. We examined the risk of a severe exacerbation in the period after a single day with high reliever use. Methods Episodes of high reliever use were quantified and exacerbations occurring post-index day with these episodes were examined post hoc in two double-blind studies comparing the efficacy and safety of budesonide/formoterol maintenance and reliever therapy (Symbicort SMART™, Turbuhaler®) 160/4.5 μg twice daily plus as needed with similar or higher maintenance doses of ICS/LABA plus SABA or formoterol. Results Budesonide/formoterol maintenance and reliever therapy significantly reduced the risk of episodes of high reliever use (>6 inhalations/day) vs. all alternative ICS/LABA regimens. With conventional fixed-dose treatment the need for exacerbation treatment within 21 days ranged from 6.0–10.1% of days post-index for all regimens compared with 2.5–3.4% of days with budesonide/formoterol maintenance and reliever therapy. Conclusions Budesonide/formoterol maintenance and reliever therapy reduces the incidence of high reliever episodes and the exacerbation burden immediately following these episodes vs. alternative ICS/LABA plus SABA regimens at up to double the maintenance dose of ICS. Trial registration These studies do not have registration numbers as they were conducted before clinical trial registration was required PMID:22816878

Noninvasive valve monitor using alternating electromagnetic field

DOEpatents

Eissenberg, David M.; Haynes, Howard D.; Casada, Donald A.

1993-01-01

One or more electrical coils are carefully located on the outside of a valve body. An alternating current passing through the coil(s) results in an alternating electromagnetic field being transmitted into the valve body and valve internals. The electromagnetic field varies in intensity and polarity in the valve. As the position of a valve internal part is changed, the electromagnetic field throughout the valve body and its internals is altered. A passive receiver coil carefully located on the outside of the valve body detects the intensity of the electromagnetic field at that location as an induced electrical voltage in the coil. With the change in position of the valve internal part, there is a corresponding change in the induced voltage as a result of the alteration in the alternating electromagnetic field at that location. Changes in the voltage provide an indication of the position and motion of valve internals.

Noninvasive valve monitor using alternating electromagnetic field

DOEpatents

Eissenberg, D.M.; Haynes, H.D.; Casada, D.A.

1993-03-16

One or more electrical coils are carefully located on the outside of a valve body. An alternating current passing through the coil(s) results in an alternating electromagnetic field being transmitted into the valve body and valve internals. The electromagnetic field varies in intensity and polarity in the valve. As the position of a valve internal part is changed, the electromagnetic field throughout the valve body and its internals is altered. A passive receiver coil carefully located on the outside of the valve body detects the intensity of the electromagnetic field at that location as an induced electrical voltage in the coil. With the change in position of the valve internal part, there is a corresponding change in the induced voltage as a result of the alteration in the alternating electromagnetic field at that location. Changes in the voltage provide an indication of the position and motion of valve internals.

Counterfactual comparison modulates fairness consideration in the mini-ultimatum game: an event-related potentials study.

PubMed

Liang, Jiafeng; Lin, Huiyan; Xiang, Jing; Wu, Hao; Li, Xu; Liang, Hongyu; Zheng, Xue

2015-04-01

Existing literature on the mini-ultimatum game indicates that counterfactual comparison between chosen and unchosen alternatives is of great importance for individual's fairness consideration. However, it is still unclear how counterfactual comparison influences the electrophysiological responses to unfair chosen offers. In conjunction with event-related potentials' (ERPs) technique, the current study aimed to explore the issue by employing a modified version of the mini-ultimatum game where a fixed set of two alternatives (unfair offer vs. fair alternative, unfair vs. hyperfair alternative, unfair offer vs. hyperunfair alternative) was presented before the chosen offer. The behavioral results showed that participants were more likely to accept unfair chosen offers when the unchosen alternative was hyperunfair than when the unchosen alternative was fair or hyperfair. The ERPs results showed that the feedback-related negativity (FRN) elicited by unfair chosen offers was insensitive to the type of unchosen alternative when correcting for possible overlap with other components. In contrast, unfair chosen offers elicited larger P300 amplitudes when the unchosen alternative was hyperunfair than when the unchosen alternative was fair or hyperfair. These findings suggest that counterfactual comparison may take effect at later stages of fairness consideration as reflected by the P300. © 2015 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

Procedures to handle inventory cluster plots that straddle two or more conditions

Treesearch

Jerold T. Hahn; Colin D. MacLean; Stanford L. Arner; William A. Bechtold

1995-01-01

We review the relative merits and field procedures for four basic plot designs to handle forest inventory plots that straddle two or more conditions, given that subplots will not be moved. A cluster design is recommended that combines fixed-area subplots and variable-radius plot (VRP) sampling. Each subplot in a cluster consists of a large fixed-area subplot for...

Functions Character

NASA Astrophysics Data System (ADS)

Dugave, Maxime; Göhmann, Frank; Kozlowski, Karol Kajetan

2014-04-01

We establish several properties of the solutions to the linear integral equations describing the infinite volume properties of the XXZ spin-1/2 chain in the disordered regime. In particular, we obtain lower and upper bounds for the dressed energy, dressed charge and density of Bethe roots. Furthermore, we establish that given a fixed external magnetic field (or a fixed magnetization) there exists a unique value of the boundary of the Fermi zone.

Field structure at the ends of a precision superconducting dipole magnet

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

Doinikov, N.I.; Eregin, V.E.; Sychevskii, S.E.

1983-10-01

Results are reported from a numerical simulation of the spatial field of a superconducting dipole magnet with a saddle-shaped winding employed in an accelerating and storage system (ASS). It is shown that the peak field in the winding can be kept to a fixed level and edge nonlinearities of the field can be suppressed by suitably shaping the front portions of the magnet.

Scoring from Contests

PubMed Central

Penn, Elizabeth Maggie

2014-01-01

This article presents a new model for scoring alternatives from “contest” outcomes. The model is a generalization of the method of paired comparison to accommodate comparisons between arbitrarily sized sets of alternatives in which outcomes are any division of a fixed prize. Our approach is also applicable to contests between varying quantities of alternatives. We prove that under a reasonable condition on the comparability of alternatives, there exists a unique collection of scores that produces accurate estimates of the overall performance of each alternative and satisfies a well-known axiom regarding choice probabilities. We apply the method to several problems in which varying choice sets and continuous outcomes may create problems for standard scoring methods. These problems include measuring centrality in network data and the scoring of political candidates via a “feeling thermometer.” In the latter case, we also use the method to uncover and solve a potential difficulty with common methods of rescaling thermometer data to account for issues of interpersonal comparability. PMID:24748759

Method for digital measurement of phase-frequency characteristics for a fixed-length ultrasonic spectrometer

NASA Astrophysics Data System (ADS)

Astashev, M. E.; Belosludtsev, K. N.; Kharakoz, D. P.

2014-05-01

One of the most accurate methods for measuring the compressibility of liquids is resonance measurement of sound velocity in a fixed-length interferometer. This method combines high sensitivity, accuracy, and small sample volume of the test liquid. The measuring principle is to study the resonance properties of a composite resonator that contains a test liquid sample. Ealier, the phase-locked loop (PLL) scheme was used for this. In this paper, we propose an alternative measurement scheme based on digital analysis of harmonic signals, describe the implementation of this scheme using commercially available data acquisition modules, and give examples of test measurements with accuracy evaluations of the results.

Analysis of fixed bed data for the extraction of a rate mechanism for the reaction of hematite with methane

DOE PAGES

Breault, Ronald W.; Monazam, Esmail R.

2015-04-01

In this study, chemical looping combustion is a promising technology for the capture of CO 2 involving redox materials as oxygen carriers. The effects of reduction conditions, namely, temperature and fuel partial pressure on the conversion products are investigated. The experiments were conducted in a laboratory fixed-bed reactor that was operated cyclically with alternating reduction and oxidation periods. Reactions are assumed to occur in the shell surrounding the particle grains with diffusion of oxygen to the surface from the grain core. Activation energies for the shell and core reactions range from 9 to 209 kJ/mol depending on the reaction step.

Generation of squeezing in a driven many-body system

NASA Astrophysics Data System (ADS)

Hebbe Madhusudhana, Bharath; Boguslawski, Matthew; Anquez, Martin; Robbins, Bryce; Barrios, Maryrose; Hoang, Thai; Chapman, Michael

2016-05-01

In a spin-1 Bose-Einstein condensate, the non-linear spin-dependent collisional interactions can create entanglement and squeezing. Typically, the condensate is initialized at an unstable fixed point of the phase space, and subsequent free evolution under a time-independent Hamiltonian creates the squeezed state. Alternatively, it is possible to generate squeezing by driving the system localized at a stable fixed point. Here, we demonstrate that periodic modulation of the Hamiltonian can generate highly squeezed states. Our measurements show -5 dB of squeezing, limited by the detection, but calculations indicate that a theoretical potential of -20 dB of squeezing. We discuss the advantages of this method compared with the typical techniques.

Planning alternative organizational frameworks for a large scale educational telecommunications system served by fixed/broadcast satellites

NASA Technical Reports Server (NTRS)

Walkmeyer, J.

1973-01-01

This memorandum explores a host of considerations meriting attention from those who are concerned with designing organizational structures for development and control of a large scale educational telecommunications system using satellites. Part of a broader investigation at Washington University into the potential uses of fixed/broadcast satellites in U.S. education, this study lays ground work for a later effort to spell out a small number of hypothetical organizational blueprints for such a system and for assessment of potential short and long term impacts. The memorandum consists of two main parts. Part A deals with subjects of system-wide concern, while Part B deals with matters related to specific system components.

Maxillary rehabilitation using fixed and removable partial dentures with attachments: a clinical report.

PubMed

dos Santos Nunes Reis, José Maurício; da Cruz Perez, Luciano Elias; Alfenas, Bruna Fernandes Moreira; de Oliveira Abi-Rached, Filipe; Filho, João Neudenir Arioli

2014-01-01

Despite requiring dental crown preparation and possible root canal treatment, besides the difficulty of clinical and laboratory repairs, and financial burden, the association between fixed (FPD) and removable partial dentures (RPD) by means of attachments is an important alternative for oral rehabilitation, particularly when the use of dental implants and FPDs is limited or not indicated. Among the advantages of attachment-retained RPDs are the improvements in esthetics and biomechanics, as well as correction of the buccal arrangement of anterior teeth in Kennedy Class III partially edentulous arches. This article describes the treatment sequence and technique for the use of attachments in therapy combining FPD/RPD. © 2013 by the American College of Prosthodontists.

Study of free-piston Stirling engine driven linear alternators

NASA Technical Reports Server (NTRS)

Nasar, S. A.; Chen, C.

1987-01-01

The analysis, design and operation of single phase, single slot tubular permanent magnet linear alternator is presented. Included is the no-load and on-load magnetic field investigation, permanent magnet's leakage field analysis, parameter identification, design guidelines and an optimal design of a permanent magnet linear alternator. For analysis of the magnetic field, a simplified magnetic circuit is utilized. The analysis accounts for saturation, leakage and armature reaction.

Hydrodynamic Dispersion in Turbulent Open-Channel Flow Over an Irregular Bed

NASA Astrophysics Data System (ADS)

Stefan, D.; Iobst, B. R.; Furbish, D. J.

2007-05-01

Characterizing hydrodynamic dispersion in open-channel flow is a key element in environmental studies aimed at modeling the transport and cycling of nutrients and pollutants. We use a simple flow model together with a particle-tracking algorithm to explore first-order influences of bed topography on the hydrodynamic dispersion. The model is based on linearized versions of the shallow-water equations for flow over an irregular bed topography composed of alternate bars. Theoretical dispersion curves were generated by simultaneously releasing tracer particles across the channel at a fixed location and keeping track of their positions for various intervals of time and different channel geometries. Particles were subject to fluctuating motions mimicking effects of turbulence. The shape and length of the tail of the dispersion curve appears to depend primarily on the time elapsed since the particles were released. For short time intervals, the curve is characterized by a steep leading edge which later transforms into a peak with a less steeply sloping front. This transition occurs more rapidly with increasing bar amplitude, and also with increasing number of alternate bars in the section traveled - thus with shorter bar wavelengths. Rhodamine WT was used in a field dye test conducted on a 150 m straight reach of Panther Creek, KY. This section of the creek has an average channel width of 6.3m, and exhibits a loose alternate bar structure with wavelength of ~55 m and amplitude of ~0.1 m. The bed of the channel has an average slope of 0.01 and consists of coarse gravel with a D85 of 6 cm. Consistent with the modeling results, the tracer test revealed a relative steep leading front and slowing decaying tail. In both the simulated and field case, this tail is similar to the behavior predicted by "dead zone" models of dispersion, and is attributable mostly to spatial variations in the local flow (with superimposed fluctuating motions) associated with vertical velocity structure combined with shoaling and deepening over the bed topography.

Gauge-independent Abelian mechanism of color confinement in gluodynamics

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

Suzuki, Tsuneo; Ishiguro, Katsuya; Sekido, Toru

Abelian mechanism of non-Abelian color confinement is observed in a gauge-independent way by high precision lattice Monte Carlo simulations in gluodynamics. An Abelian gauge field is extracted with no gauge fixing. Then we decompose the Abelian field into regular photon and singular monopole parts using the Hodge decomposition. We find that only the monopole part is responsible for the string tension. The investigation of the flux-tube profile then shows that an Abelian electric field defined in an arbitrary color direction is squeezed by the monopole supercurrent with the same color direction, and the quantitative features of flux squeezing are consistentmore » with those observed previously after Abelian projections with gauge fixing. Non-Abelian color confinement is explained in the framework of the gauge-independent Abelian dual Meissner effect.« less

A Variable Energy CW Compact Accelerator for Ion Cancer Therapy

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

Johnstone, Carol J.; Taylor, J.; Edgecock, R.

2016-03-10

Cancer is the second-largest cause of death in the U.S. and approximately two-thirds of all cancer patients will receive radiation therapy with the majority of the radiation treatments performed using x-rays produced by electron linacs. Charged particle beam radiation therapy, both protons and light ions, however, offers advantageous physical-dose distributions over conventional photon radiotherapy, and, for particles heavier than protons, a significant biological advantage. Despite recognition of potential advantages, there is almost no research activity in this field in the U.S. due to the lack of clinical accelerator facilities offering light ion therapy in the States. In January, 2013, amore » joint DOE/NCI workshop was convened to address the challenges of light ion therapy [1], inviting more than 60 experts from diverse fields related to radiation therapy. This paper reports on the conclusions of the workshop, then translates the clinical requirements into accelerat or and beam-delivery technical specifications. A comparison of available or feasible accelerator technologies is compared, including a new concept for a compact, CW, and variable energy light ion accelerator currently under development. This new light ion accelerator is based on advances in nonscaling Fixed-Field Alternating gradient (FFAG) accelerator design. The new design concepts combine isochronous orbits with long (up to 4m) straight sections in a compact racetrack format allowing inner circulating orbits to be energy selected for low-loss, CW extraction, effectively eliminating the high-loss energy degrader in conventional CW cyclotron designs.« less

Modeling and simulation of deformation of hydrogels responding to electric stimulus.

PubMed

Li, Hua; Luo, Rongmo; Lam, K Y

2007-01-01

A model for simulation of pH-sensitive hydrogels is refined in this paper to extend its application to electric-sensitive hydrogels, termed the refined multi-effect-coupling electric-stimulus (rMECe) model. By reformulation of the fixed-charge density and consideration of finite deformation, the rMECe model is able to predict the responsive deformations of the hydrogels when they are immersed in a bath solution subject to externally applied electric field. The rMECe model consists of nonlinear partial differential governing equations with chemo-electro-mechanical coupling effects and the fixed-charge density with electric-field effect. By comparison between simulation and experiment extracted from literature, the model is verified to be accurate and stable. The rMECe model performs quantitatively for deformation analysis of the electric-sensitive hydrogels. The influences of several physical parameters, including the externally applied electric voltage, initial fixed-charge density, hydrogel strip thickness, ionic strength and valence of surrounding solution, are discussed in detail on the displacement and average curvature of the hydrogels.

Beneficial effects of aluminum enrichment on nitrogen-fixing cyanobacteria in the South China Sea.

PubMed

Liu, Jiaxing; Zhou, Linbin; Ke, Zhixin; Li, Gang; Shi, Rongjun; Tan, Yehui

2018-04-01

Few studies focus on the effects of aluminum (Al) on marine nitrogen-fixing cyanobacteria, which play important roles in the ocean nitrogen cycling. To examine the effects of Al on the nitrogen-fixing cyanobacteria, bioassay experiments in the oligotrophic South China Sea (SCS) and culture of Crocosphaera watsonii in the laboratory were conducted. Field data showed that 200 nM Al stimulated the growth and the nitrogenase gene expression of Trichodesmium and unicellular diazotrophic cyanobacterium group A, and the nitrogen fixation rates of the whole community. Laboratory experiments demonstrated that Al stimulated the growth and nitrogen fixation of C. watsonii under phosphorus limited conditions. Both field and laboratory results indicated that Al could stimulate the growth of diazotrophs and nitrogen fixation in oligotrophic oceans such as the SCS, which is likely related to the utilization of phosphorus, implying that Al plays an important role in the ocean nitrogen and carbon cycles by influencing nitrogen fixation. Copyright © 2018 Elsevier Ltd. All rights reserved.

DeepFix: A Fully Convolutional Neural Network for Predicting Human Eye Fixations.

PubMed

Kruthiventi, Srinivas S S; Ayush, Kumar; Babu, R Venkatesh

2017-09-01

Understanding and predicting the human visual attention mechanism is an active area of research in the fields of neuroscience and computer vision. In this paper, we propose DeepFix, a fully convolutional neural network, which models the bottom-up mechanism of visual attention via saliency prediction. Unlike classical works, which characterize the saliency map using various hand-crafted features, our model automatically learns features in a hierarchical fashion and predicts the saliency map in an end-to-end manner. DeepFix is designed to capture semantics at multiple scales while taking global context into account, by using network layers with very large receptive fields. Generally, fully convolutional nets are spatially invariant-this prevents them from modeling location-dependent patterns (e.g., centre-bias). Our network handles this by incorporating a novel location-biased convolutional layer. We evaluate our model on multiple challenging saliency data sets and show that it achieves the state-of-the-art results.

Risk management policies and practices regarding radio frequency electromagnetic fields: results from a WHO survey.

PubMed

Dhungel, Amit; Zmirou-Navier, Denis; van Deventer, Emilie

2015-04-01

This study aims to describe current risk management practices and policies across the world in relation to personal exposures from devices emitting radiofrequency fields, environmental exposures from fixed installations and exposures in the work environment. Data from 86 countries representing all WHO regions were collected through a survey. The majority of countries (76.8 %) had set exposure limits for mobile devices, almost all (90.7 %) had set public exposure limits for fixed installations and 76.5 % had specified exposure limits for personnel in occupational settings. A number of other policies had been implemented at the national level, ranging from information provisions on how to reduce personal exposures and restrictions of usage for certain populations, such as children or pregnant women to prevention of access around base stations. This study suggests that countries with higher mobile subscriptions tend to have set radiofrequency exposure limits for mobile devices and to have provisions on exposure measurements about fixed installations. © The Author 2014. Published by Oxford University Press.

A Spaceborne Synthetic Aperture Radar Partial Fixed-Point Imaging System Using a Field- Programmable Gate Array—Application-Specific Integrated Circuit Hybrid Heterogeneous Parallel Acceleration Technique

PubMed Central

Li, Bingyi; Chen, Liang; Wei, Chunpeng; Xie, Yizhuang; Chen, He; Yu, Wenyue

2017-01-01

With the development of satellite load technology and very large scale integrated (VLSI) circuit technology, onboard real-time synthetic aperture radar (SAR) imaging systems have become a solution for allowing rapid response to disasters. A key goal of the onboard SAR imaging system design is to achieve high real-time processing performance with severe size, weight, and power consumption constraints. In this paper, we analyse the computational burden of the commonly used chirp scaling (CS) SAR imaging algorithm. To reduce the system hardware cost, we propose a partial fixed-point processing scheme. The fast Fourier transform (FFT), which is the most computation-sensitive operation in the CS algorithm, is processed with fixed-point, while other operations are processed with single precision floating-point. With the proposed fixed-point processing error propagation model, the fixed-point processing word length is determined. The fidelity and accuracy relative to conventional ground-based software processors is verified by evaluating both the point target imaging quality and the actual scene imaging quality. As a proof of concept, a field- programmable gate array—application-specific integrated circuit (FPGA-ASIC) hybrid heterogeneous parallel accelerating architecture is designed and realized. The customized fixed-point FFT is implemented using the 130 nm complementary metal oxide semiconductor (CMOS) technology as a co-processor of the Xilinx xc6vlx760t FPGA. A single processing board requires 12 s and consumes 21 W to focus a 50-km swath width, 5-m resolution stripmap SAR raw data with a granularity of 16,384 × 16,384. PMID:28672813

Electromagnetic Interference in Implantable Defibrillators in Single-Engine Fixed-Wing Aircraft.

PubMed

de Rotte, Alexandra A J; van der Kemp, Peter; Mundy, Peter A; Rienks, Rienk; de Rotte, August A

2017-01-01

Little is known about the possible electromagnetic interferences (EMI) in the single-engine fixed-wing aircraft environment with implantable cardio-defibrillators (ICDs). Our hypothesis is that EMI in the cockpit of a single-engine fixed-wing aircraft does not result in erroneous detection of arrhythmias and the subsequent delivery of an inappropriate device therapy. ICD devices of four different manufacturers, incorporated in a thorax phantom, were transported in a Piper Dakota Aircraft with ICAO type designator P28B during several flights. The devices under test were programmed to the most sensitive settings for detection of electromagnetic signals from their environment. After the final flight the devices under test were interrogated with the dedicated programmers in order to analyze the number of tachycardias detected. Cumulative registration time of the devices under test was 11,392 min, with a mean of 2848 min per device. The registration from each one of the devices did not show any detectable "tachycardia" or subsequent inappropriate device therapy. This indicates that no external signals, which could be originating from electromagnetic fields from the aircraft's avionics, were detected by the devices under test. During transport in the cockpit of a single-engine fixed-wing aircraft, the tested ICDs did not show any signs of being affected by electromagnetic fields originating from the avionics of the aircraft. This current study indicates that EMI is not a potential safety issue for transportation of passengers with an ICD implanted in a single-engine fixed-wing aircraft.de Rotte AAJ, van der Kemp P, Mundy PA, Rienks R, de Rotte AA. Electromagnetic interference in implantable defibrillators in single-engine fixed-wing aircraft. Aerosp Med Hum Perform. 2017; 88(1):52-55.

A Spaceborne Synthetic Aperture Radar Partial Fixed-Point Imaging System Using a Field- Programmable Gate Array-Application-Specific Integrated Circuit Hybrid Heterogeneous Parallel Acceleration Technique.

PubMed

Yang, Chen; Li, Bingyi; Chen, Liang; Wei, Chunpeng; Xie, Yizhuang; Chen, He; Yu, Wenyue

2017-06-24

With the development of satellite load technology and very large scale integrated (VLSI) circuit technology, onboard real-time synthetic aperture radar (SAR) imaging systems have become a solution for allowing rapid response to disasters. A key goal of the onboard SAR imaging system design is to achieve high real-time processing performance with severe size, weight, and power consumption constraints. In this paper, we analyse the computational burden of the commonly used chirp scaling (CS) SAR imaging algorithm. To reduce the system hardware cost, we propose a partial fixed-point processing scheme. The fast Fourier transform (FFT), which is the most computation-sensitive operation in the CS algorithm, is processed with fixed-point, while other operations are processed with single precision floating-point. With the proposed fixed-point processing error propagation model, the fixed-point processing word length is determined. The fidelity and accuracy relative to conventional ground-based software processors is verified by evaluating both the point target imaging quality and the actual scene imaging quality. As a proof of concept, a field- programmable gate array-application-specific integrated circuit (FPGA-ASIC) hybrid heterogeneous parallel accelerating architecture is designed and realized. The customized fixed-point FFT is implemented using the 130 nm complementary metal oxide semiconductor (CMOS) technology as a co-processor of the Xilinx xc6vlx760t FPGA. A single processing board requires 12 s and consumes 21 W to focus a 50-km swath width, 5-m resolution stripmap SAR raw data with a granularity of 16,384 × 16,384.

Hybrid simulations of radial transport driven by the Rayleigh-Taylor instability

NASA Astrophysics Data System (ADS)

Delamere, P. A.; Stauffer, B. H.; Ma, X.

2017-12-01

Plasma transport in the rapidly rotating giant magnetospheres is thought to involve a centrifugally-driven flux tube interchange instability, similar to the Rayleigh-Taylor (RT) instability. In three dimensions, the convective flow patterns associated with the RT instability can produce strong guide field reconnection, allowing plasma mass to move radially outward while conserving magnetic flux (Ma et al., 2016). We present a set of hybrid (kinetic ion / fluid electron) plasma simulations of the RT instability using high plasma beta conditions appropriate for Jupiter's inner and middle magnetosphere. A density gradient, combined with a centrifugal force, provide appropriate RT onset conditions. Pressure balance is achieved by initializing two ion populations: one with fixed temperature, but varying density, and the other with fixed density, but a temperature gradient that offsets the density gradient from the first population and the centrifugal force (effective gravity). We first analyze two-dimensional results for the plane perpendicular to the magnetic field by comparing growth rates as a function of wave vector following Huba et al. (1998). Prescribed perpendicular wave modes are seeded with an initial velocity perturbation. We then extend the model to three dimensions, introducing a stabilizing parallel wave vector. Boundary conditions in the parallel direction prohibit motion of the magnetic field line footprints to model the eigenmodes of the magnetodisc's resonant cavity. We again compare growth rates based on perpendicular wave number, but also on the parallel extent of the resonant cavity, which fixes the size of the largest parallel wavelength. Finally, we search for evidence of strong guide field magnetic reconnection within the domain by identifying areas with large parallel electric fields or changes in magnetic field topology.

Displacement efficiency of alternative energy and trans-provincial imported electricity in China

PubMed Central

Hu, Yuanan; Cheng, Hefa

2017-01-01

China has invested heavily on alternative energy, but the effectiveness of such energy sources at substituting the dominant coal-fired generation remains unknown. Here we analyse the displacement of fossil-fuel-generated electricity by alternative energy, primarily hydropower, and by trans-provincial imported electricity in China between 1995 and 2014 using two-way fixed-effects panel regression models. Nationwide, each unit of alternative energy displaces nearly one-quarter of a unit of fossil-fuel-generated electricity, while each unit of imported electricity (regardless of the generation source) displaces ∼0.3 unit of fossil-fuel electricity generated locally. Results from the six regional grids indicate that significant displacement of fossil-fuel-generated electricity occurs once the share of alternative energy in the electricity supply mix exceeds ∼10%, which is accompanied by 10–50% rebound in the consumption of fossil-fuel-generated electricity. These findings indicate the need for a policy that integrates carbon taxation, alternative energy and energy efficiency to facilitate China's transition towards a low-carbon economy. PMID:28211467

The FasT-Fix Repair Technique for Ramp Lesion of the Medial Meniscus.

PubMed

Li, Wei-Ping; Chen, Zhong; Song, Bin; Yang, Rui; Tan, Weiquan

2015-03-01

This technical note describes a new arthroscopic technique to repair the peripheral attachment lesion of the posterior horn of the medial meniscus. The operation was performed under arthroscopy using a standard anterior portal. A FasT-Fix needle was inserted obliquely close to the tibial plateau and the first implant was inserted into the joint capsule depending on its bending angle underneath the meniscus. The second implant was inserted through 1/3 periphery of the meniscus into the meniscocapsular area. The pre-tied self-sliding knot was tensioned to achieve secure fixation of the posterior meniscal peripheral attachment at the original attachment point. From August 2011 to February 2014, 23 knees were diagnosed as ramp lesion, underwent meniscal repair using FasT-Fix technique. All patients were followed up for average 14 months. The Lysholm score improved from preoperative 64.4±4.52 to postoperative 91.2±4.60. We believe that the FasT-Fix technique via the standard anterior portal can be a more convenient and less traumatic alternative for repair of the peripheral attachment lesion of the posterior horn of the medial meniscus in the anterior cruciate ligament deficient knee.

Static Performance of a Fixed-Geometry Exhaust Nozzle Incorporating Porous Cavities for Shock-Boundary Layer Interaction Control

NASA Technical Reports Server (NTRS)

Asbury, Scott C.; Hunter, Craig A.

1999-01-01

An investigation was conducted in the model preparation area of the Langley 16-Foot Transonic Tunnel to determine the internal performance of a fixed-geometry exhaust nozzle incorporating porous cavities for shock-boundary layer interaction control. Testing was conducted at static conditions using a sub-scale nozzle model with one baseline and 27 porous configurations. For the porous configurations, the effects of percent open porosity, hole diameter, and cavity depth were determined. All tests were conducted with no external flow at nozzle pressure ratios from 1.25 to approximately 9.50. Results indicate that baseline nozzle performance was dominated by unstable, shock-induced, boundary-layer separation at over-expanded conditions. Porous configurations were capable of controlling off-design separation in the nozzle by either alleviating separation or encouraging stable separation of the exhaust flow. The ability of the porous nozzle concept to alternately alleviate separation or encourage stable separation of exhaust flow through shock-boundary layer interaction control offers tremendous off-design performance benefits for fixed-geometry nozzle installations. In addition, the ability to encourage separation on one divergent flap while alleviating it on the other makes it possible to generate thrust vectoring using a fixed-geometry nozzle.

Removable partial denture supported by implants with prefabricated telescopic abutments - a case report.

PubMed

Kumar, Lalit; Sehgal, Komal

2014-06-01

Implants have been designed to rehabilitate edentulous patients with fixed prosthesis or implant supported overdentures. Implant-supported single crowns and fixed partial dentures have become successful treatment alternatives to removable and fixed partial dentures. However, it is common to have clinical situations which make it impossible to use conventional as well as implant supported fixed partial dentures. The implant supported removable partial dentures can be a treatment modality that offers the multitude of benefits of implant-based therapy-biologic, biomechanical, social, and psychological to such patients. The aim of this article is to present a case report describing the fabrication and advantages of removable partial denture supported by teeth and implants for a patient with long edentulous span. The patient was satisfied with his dentures in terms of function and aesthetics. Regular follow-up visits over a period of three years revealed that the periodontal condition of remaining natural dentition and peri-implant conditions were stable. There was no evidence of excessive residual ridge resorption or mobility of the teeth, nor were any visible changes in the bone levels of the natural teeth or implants noted on radiographs.

Tunable terahertz wave-plate based on dual-frequency liquid crystal controlled by alternating electric field.

PubMed

Yu, Jian-Ping; Chen, Sai; Fan, Fei; Cheng, Jie-Rong; Xu, Shi-Tong; Wang, Xiang-Hui; Chang, Sheng-Jiang

2018-01-22

In this work, the optically anisotropic property of dual-frequency liquid crystals (DFLC) in terahertz (THz) regime has been experimentally investigated, which indicates that the refractive index and birefringence of DFLC can be continuously modulated by both the alternating frequency and intensity of the alternating electric field. This tunability originates from the rotation of DFLC molecules induced by alternating electric fields. The results show that by modulating the alternating frequency from 1 kHz to 100 kHz under 30 kV/m electric field, the 600 μm thickness DFLC cell can play as a tunable quarter-wave plate above 0.68 THz, or a half-wave plate above 1.33 THz. Besides, it can be viewed as a tunable THz phase shifter from 0 to π. Therefore, due to its novel tuning mechanism, DFLC will be of great significance in dynamic manipulating on THz phase and polarization.

30 CFR 285.710 - When conducting onsite installation inspections, what must the CVA or project engineer do?

Code of Federal Regulations, 2011 CFR

2011-07-01

... ALTERNATE USES OF EXISTING FACILITIES ON THE OUTER CONTINENTAL SHELF Facility Design, Fabrication, and..., survey, or check, the installation items required by this section. (a) The CVA or project engineer must... according to the Facility Design Report and the Fabrication and Installation Report. (b) For a fixed or...

Income Share Agreements on Campus: A Practice Guide

ERIC Educational Resources Information Center

American Institutes for Research, 2015

2015-01-01

Next fall, students at Purdue University may have a new way to pay their tuition: income share agreements (ISAs). ISAs are an alternative form of higher education financing in which students pledge a fixed percentage of future earnings in exchange for money to pay for college. ISAs present a new challenge to the nation's colleges and universities,…

13 CFR 120.102 - Funds not available from alternative sources, including personal resources of principals.

Code of Federal Regulations, 2010 CFR

2010-01-01

... accounts, CDs, stocks, bonds, or other similar assets. Equity in real estate holdings and other fixed... source) when that owner's liquid assets exceed the amounts specified in paragraphs (a) (1) through (3) of... applicant must inject any personal liquid assets which are in excess of two times the total financing...

A Critical Analysis of Active Learning and an Alternative Pedagogical Framework for Introductory Information Systems Courses

ERIC Educational Resources Information Center

Drake, John R.

2012-01-01

Active learning has been championed in academic circles as the pedagogical fix to boring lectures typically found in introduction to information systems courses. However, the literature on active learning is mixed. In this paper, we critically examine active learning research and discover a misplaced emphasis leading to paradoxical findings in…

Inhibition of decay fungi using cotton cellulose hydrolysis as a model for wood decay

Treesearch

Frederick Green

2000-01-01

Environmental pressures to replace chromium and arsenic in fixed waterborne preservatives have been increasing. Potential inhibitors of brown-, white- and soft-rot fungi need to be evaluated as alternative preservatives by screening and testing in, in vitro model systems. This paper reports the inhibition of cellulose depolymerization and weight loss of selected decay...

Soil moisture patterns in a northern coniferous forest

Treesearch

Thomas F. McLintock

1959-01-01

The trend of soil moisture during the growing season, the alternate wetting from rainfall and drying during clear weather, determines the amount of moisture available for tree growth and also fixes, in part, the environment for root growth. In much of the northern coniferous region both moisture content and root environment are in turn affected by the hummock-and-...

40 CFR 147.1155 - Requirements for all wells.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Requirements for all wells. 147.1155... Requirements for all wells. (a) Area of review. Notwithstanding the alternatives presented in § 146.6 of this chapter, the area of review for Class II wells shall be a fixed radius as described in § 146.6(b) of this...

40 CFR 147.1155 - Requirements for all wells.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Requirements for all wells. 147.1155... Requirements for all wells. (a) Area of review. Notwithstanding the alternatives presented in § 146.6 of this chapter, the area of review for Class II wells shall be a fixed radius as described in § 146.6(b) of this...

Serial Learning in Rats: A Test of Three Hypotheses

ERIC Educational Resources Information Center

Capaldi, E. J.; Miller, Ronald Mellado

2004-01-01

Findings obtained by providing rats with a single fixed series of events, A-B-C-..., often are equally compatible with three alternative serial learning interpretations: that the signal for items is (A) their position in the series (position view), (B) the prior item of the series (chaining view), and (C) one, two, or more prior items of the…

Flight Simulator Evaluation of Display Media Devices for Synthetic Vision Concepts

NASA Technical Reports Server (NTRS)

Arthur, J. J., III; Williams, Steven P.; Prinzel, Lawrence J., III; Kramer, Lynda J.; Bailey, Randall E.

2004-01-01

The Synthetic Vision Systems (SVS) Project of the National Aeronautics and Space Administration's (NASA) Aviation Safety Program (AvSP) is striving to eliminate poor visibility as a causal factor in aircraft accidents as well as enhance operational capabilities of all aircraft. To accomplish these safety and capacity improvements, the SVS concept is designed to provide a clear view of the world around the aircraft through the display of computer-generated imagery derived from an onboard database of terrain, obstacle, and airport information. Display media devices with which to implement SVS technology that have been evaluated so far within the Project include fixed field of view head up displays and head down Primary Flight Displays with pilot-selectable field of view. A simulation experiment was conducted comparing these display devices to a fixed field of view, unlimited field of regard, full color Helmet-Mounted Display system. Subject pilots flew a visual circling maneuver in IMC at a terrain-challenged airport. The data collected for this experiment is compared to past SVS research studies.

Simulation and Evaluation of Small Scale Solar Power Tower Performance under Malaysia Weather Conditions

NASA Astrophysics Data System (ADS)

Gamil, A. M.; Gilani, S. I.; Al-Kayiem, H. H.

2013-06-01

Solar energy is the most available, clean, and inexpensive source of energy among the other renewable sources of energy. Malaysia is an encouraging location for the development of solar energy systems due to abundant sunshine (10 hours daily with average solar energy received between 1400 and 1900 kWh/m2). In this paper the design of heliostat field of 3 dual-axis heliostat units located in Ipoh, Malaysia is introduced. A mathematical model was developed to estimate the sun position and calculate the cosine losses in the field. The study includes calculating the incident solar power to a fixed target on the tower by analysing the tower height and ground distance between the heliostat and the tower base. The cosine efficiency was found for each heliostat according to the sun movement. TRNSYS software was used to simulate the cosine efficiencies and field hourly incident solar power input to the fixed target. The results show the heliostat field parameters and the total incident solar input to the receiver.

Wireless Open-Circuit In-Plane Strain and Displacement Sensor Requiring No Electrical Connections

NASA Technical Reports Server (NTRS)

Woodard, Stanley E. (Inventor)

2014-01-01

A wireless in-plane strain and displacement sensor includes an electrical conductor fixedly coupled to a substrate subject to strain conditions. The electrical conductor is shaped between its ends for storage of an electric field and a magnetic field, and remains electrically unconnected to define an unconnected open-circuit having inductance and capacitance. In the presence of a time-varying magnetic field, the electrical conductor so-shaped resonates to generate harmonic electric and magnetic field responses. The sensor also includes at least one electrically unconnected electrode having an end and a free portion extending from the end thereof. The end of each electrode is fixedly coupled to the substrate and the free portion thereof remains unencumbered and spaced apart from a portion of the electrical conductor so-shaped. More specifically, at least some of the free portion is disposed at a location lying within the magnetic field response generated by the electrical conductor. A motion guidance structure is slidingly engaged with each electrode's free portion in order to maintain each free portion parallel to the electrical conductor so-shaped.

Comparing line-intersect, fixed-area, and point relascope sampling for dead and downed coarse woody material in a managed northern hardwood forest

Treesearch

G. J. Jordan; M. J. Ducey; J. H. Gove

2004-01-01

We present the results of a timed field trial comparing the bias characteristics and relative sampling efficiency of line-intersect, fixed-area, and point relascope sampling for downed coarse woody material. Seven stands in a managed northern hardwood forest in New Hampshire were inventoried. Significant differences were found among estimates in some stands, indicating...

Will the "Fixes" Fall Flat? Prospects for Quality Measures and Payment Incentives to Control Healthcare Spending.

PubMed

Hauswald, Erik; Sklar, David

2017-04-01

Payment systems in the US healthcare system have rewarded physicians for services and attempted to control healthcare spending, with rewards and penalties based upon projected goals for future spending. The incorporation of quality goals and alternatives to fee-for-service was introduced to replace the previous system of rewards and penalties. We describe the history of the US healthcare payment system, focusing on Medicare and the efforts to control spending through the Sustainable Growth Rate. We describe the latest evolution of the payment system, which emphasizes quality measurement and alternative payment models. We conclude with suggestions for how to influence physician behavior through education and payment reform so that their behavior aligns with alternative care models to control spending in the future.

Paleomagnetic Tests of Global Plate Reconstructions with Fixed and Moving Hotspots

NASA Astrophysics Data System (ADS)

Andrews, D. L.; Gordon, R. G.; Horner-Johnson, B. C.

2004-12-01

Three distinct approaches have been used in prior work to estimate the motion of the Pacific basin plates relative to the surrounding continents. The first approach is to use the global plate motion circuit through Antarctica (e.g., the Pacific plate to the Antarctic plate to the African plate to the North American plate). An update to this approach is to incorporate the modest mid-Tertiary motion between East and West Antarctica estimated by Cande et al. (2000). A recently proposed second approach is to take an alternative circuit for the early Tertiary of the Pacific plate to the Australian plate to the East Antarctic plate to the African plate to the North American plate (Steinberger et al. 2004). The third approach is to assume that the hotspots in the Pacific Ocean are fixed relative to those in the Atlantic and Indian Oceans (e.g., Engebretson et al., 1986), which we recently showed indicates motion between East and West Antarctica of 800 ± 500 km near the Ross Sea Embayment. The first approach (global plate motion circuit through Antarctica) indicates very rapid motion between Pacific and Indo-Atlantic hotspots during the early Tertiary (e.g., Raymond et al. 2000). The second approach (global plate motion circuit through Australia) indicates slower, but still substantial, motion between Pacific and Indo-Atlantic hotspots (Steinberger et al. 2004). Because each of the three approaches predicts distinctly different motion between the Pacific plate and the continental plates, they can be tested with paleomagnetic data. The results of such tests indicate that the first approach leads to systematic and significant misfits between Pacific and non-Pacific early Tertiary and Late Cretaceous paleomagnetic poles. The second approach leads to slightly smaller misfits. In contrast, the circuit based on fixed hotspots brings the Pacific and non-Pacific paleomagnetic poles into consistency. Thus the paleomagnetic data decisively favor fixed hotspots over the alternative approaches and suggests that motion between hotspots is substantially less than inferred by Steinberger et al. (2004).

Relative potency of varenicline or fluvoxamine to reduce responding for ethanol versus food depends on the presence or absence of concurrently earned food.

PubMed

Ginsburg, Brett C; Lamb, Richard J

2014-03-01

Varenicline, a nicotinic partial agonist, selectively reduces ethanol (EtOH)- versus sucrose-maintained behavior when tested in separate groups, yet like the indirect agonist fluvoxamine, this selectively inverts when EtOH and food are concurrently available. Here, we extend these findings by examining varenicline and fluvoxamine effects under a multiple concurrent schedule where food and EtOH are concurrently available in different components: Component 1 where the food fixed-ratio was 25 and Component 2 where the food fixed-ratio was 75. The EtOH fixed-ratio was always 5. Food-maintained responding predominated in Component 1, while EtOH-maintained responding predominated in Component 2. In a second experiment, varenicline effects were assessed under a multiple schedule where food, then EtOH, then again food were available in separate 5-minute components with fixed-ratios of 5 for each reinforcement. In the multiple concurrent schedule, varenicline was more potent at reducing food- versus EtOH-maintained responding in both components and reduced EtOH-maintained responding more potently during Component 1 (when food was almost never earned) than in Component 2 (where food was often earned). Fluvoxamine was similarly potent at reducing food- and EtOH-maintained responding. Under the multiple schedule, varenicline, like fluvoxamine, more potently decreases EtOH- versus food maintained responding when only food or EtOH is available in separate components. These results demonstrate that selective effects on drug- versus alternative-maintained behavior depend on the schedule arrangement, and assays in which EtOH or an alternative is the only programmed reinforcement may overestimate the selectivity of treatments to decrease EtOH self-administration. Thus selective effects obtained under one assay may not generalize to another. Better understanding the behavioral mechanisms responsible for these results may help to guide pharmaco-therapeutic development for substance use disorders.

Contact stresses, pressure and area in a fixed-bearing total ankle replacement: a finite element analysis.

PubMed

Martinelli, Nicolo; Baretta, Silvia; Pagano, Jenny; Bianchi, Alberto; Villa, Tomaso; Casaroli, Gloria; Galbusera, Fabio

2017-11-25

Mobile-bearing ankle implants with good clinical results continued to increase the popularity of total ankle arthroplasty to address endstage ankle osteoarthritis preserving joint movement. Alternative solutions used fixed-bearing designs, which increase stability and reduce the risk of bearing dislocation, but with a theoretical increase of contact stresses leading to a higher polyethylene wear. The purpose of this study was to investigate the contact stresses, pressure and area in the polyethylene component of a new total ankle replacement with a fixed-bearing design, using 3D finite element analysis. A three-dimensional finite element model of the Zimmer Trabecular Metal Total Ankle was developed and assembled based on computed tomography images. Three different sizes of the polyethylene insert were modeled, and a finite element analysis was conducted to investigate the contact pressure, the von Mises stresses and the contact area of the polyethylene component during the stance phase of the gait cycle. The peak value of pressure was found in the anterior region of the articulating surface, where it reached 19.8 MPa at 40% of the gait cycle. The average contact pressure during the stance phase was 6.9 MPa. The maximum von Mises stress of 14.1 MPa was reached at 40% of the gait cycle in the anterior section. In the central section, the maximum von Mises stress of 10.8 MPa was reached at 37% of the gait cycle, whereas in the posterior section the maximum stress of 5.4 MPa was reached at the end of the stance phase. The new fixed-bearing total ankle replacement showed a safe mechanical behavior and many clinical advantages. However, advanced models to quantitatively estimate the wear are need. To the light of the clinical advantages, we conclude that the presented prosthesis is a good alternative to the other products present in the market.

Geohydrology and simulation of ground-water flow near Los Alamos, north-central New Mexico

USGS Publications Warehouse

Frenzel, P.F.

1995-01-01

An existing model was modified in recognition of new geohydrologic interpretations and adjusted to simulate hydrographs in well fields in the Los Alamos area. Hydraulic-head drawdowns at the Buckman well field resulting from two projected ground-water-withdrawal alternatives were estimated with the modified model. The Chaquehui formation (informal usage) is the main new feature of recent hydrologic interpretations for the Los Alamos area. The Chaquehui occupies a 'channel' that was eroded or faulted into the Tesuque Formation, and the Chaquehui is more permeable than the Tesuque. The Chaquehui is a major producing zone in the Pajarito Mesa well field and to a lesser extent in the Guaje well field. Model modification included splitting the four layers of the McAda-Wasiolek model (McAda, D.P., and Wasiolek, Maryann, 1988, Simulation of the regional geohydrology of the Tesuque aquifer system near Santa Fe, New Mexico: U.S. Geological Survey Water- Resources Investigations Report 87-4056, 71 p.) into eight layers to better simulate vertical ground-water movement. Other model modifications were limited as much as possible to the area of interest near Los Alamos and consisted mainly of adjusting hydraulic-conductivity values representing the Tesuque Formation, Chaquehui formation (informal usage), and Puye Formation, and adjusting simulated recharge along the Pajarito Fault Zone west of Los Alamos. Adjustments were based mainly on simulation of fluctuations in measured hydraulic heads near Los Alamos. Two possible alternative plans for replacing Guaje well field production were suggested by Los Alamos National Laboratory. In the first plan (Guaje alternative), the Guaje field would be renewed with four new wells replacing the existing production wells in the Guaje field. In the second plan (Pajarito-Otowi alternative), the Guaje well field would be retired and its former production would be made up by additional withdrawals from the Pajarito Mesa and Otowi well fields. A projection for each of these alternatives was made through 2012 using the new eight- layer model. In the Guaje field, projected hydraulic heads at the end of 2012 were as much as 50 feet lower with the Guaje alternative; in the Pajarito Mesa field, hydraulic heads were as much as 12 feet higher with the Guaje alternative. At the western end of the Los Alamos well field, projected hydraulic heads were about 20 feet higher with the Guaje alternative; at the eastern end of the Los Alamos field, the difference between alternatives was much less. At the Buckman field, projected hydraulic heads were about 2 feet higher with the Guaje alternative because the Buckman field is closer to the Pajarito Mesa field than to the Guaje field. Ways of improving the understanding of the flow system include developing a more accurate representation of the structure and extent of the Tesuque Formation, Chaquehui formation, and Puye Formation of the Santa Fe Group and obtaining more detailed geologic and hydrologic data for the Chaquehui and Puye. Data that describe water chemistry, hydraulic head, and degree of saturation would be valuable for determining the location and quantity of recharge on the Pajarito Plateau, especially along the west side of the Plateau and in canyon bottoms. Chloride concentrations in soil at the top of the Bandelier Tuff could be used to verify the concept that evapotranspiration accounts for nearly all precipitation over a large area of the plateau.

Parallel Fixed Point Implementation of a Radial Basis Function Network in an FPGA

PubMed Central

de Souza, Alisson C. D.; Fernandes, Marcelo A. C.

2014-01-01

This paper proposes a parallel fixed point radial basis function (RBF) artificial neural network (ANN), implemented in a field programmable gate array (FPGA) trained online with a least mean square (LMS) algorithm. The processing time and occupied area were analyzed for various fixed point formats. The problems of precision of the ANN response for nonlinear classification using the XOR gate and interpolation using the sine function were also analyzed in a hardware implementation. The entire project was developed using the System Generator platform (Xilinx), with a Virtex-6 xc6vcx240t-1ff1156 as the target FPGA. PMID:25268918

Transforce lingual appliances pre-adjusted invisible appliances simplify treatment.

PubMed

Clark, William John

2011-01-01

Transforce lingual appliances are designed to be used in conjunction with conventional fixed appliances. Lingual arch development is normally followed by bonded fixed appliances to detail the occlusion. Alternatively Transforce appliance treatment is an efficient method of preparing complex malocclusions prior to a finishing stage with invisible appliances. This approach is ideal for adult treatment, using light continuous forces for arch development with appliances that are comfortable to wear. Sagittal and Transverse appliances are designed for arch development in a range of sizes for contracted arches. They can be used to treat all classes of malocclusion and are pre-adjusted fixed/removable devices for non-compliance treatment. Force modules with nickel titanium coil springs enclosed in a tube deliver a gentle, biocompatible continuous force with a long range of action. They are excellent for mixed dentition and ideal for adult arch development. There are multiple sizes for upper and lower arch development and a sizing chart may be placed over a study model for correct selection, eliminating the need for laboratory work.

Studies in integrated line-and packet-switched computer communication systems

NASA Astrophysics Data System (ADS)

Maglaris, B. S.

1980-06-01

The problem of efficiently allocating the bandwidth of a trunk to both types of traffic is handled for various system and traffic models. A performance analysis is carried out both for variable and fixed frame schemes. It is shown that variable frame schemes, adjusting the frame length according to the traffic variations, offer better trunk utilization at the cost of the additional hardware and software complexity needed because of the lack of synchronization. An optimization study on the fixed frame schemes follows. The problem of dynamically allocating the fixed frame to both types of traffic is formulated as a Markovian Decision process. It is shown that the movable boundary scheme, suggested for commercial implementations of integrated multiplexors, offers optimal or near optimal performance and simplicity of implementation. Finally, the behavior of the movable boundary integrated scheme is studied for tandem link connections. Under the assumptions made for the line-switched traffic, the forward allocation technique is found to offer the best alternative among different path set-up strategies.

Comparison of alternatives to amplitude thresholding for onset detection of acoustic emission signals

NASA Astrophysics Data System (ADS)

Bai, F.; Gagar, D.; Foote, P.; Zhao, Y.

2017-02-01

Acoustic Emission (AE) monitoring can be used to detect the presence of damage as well as determine its location in Structural Health Monitoring (SHM) applications. Information on the time difference of the signal generated by the damage event arriving at different sensors in an array is essential in performing localisation. Currently, this is determined using a fixed threshold which is particularly prone to errors when not set to optimal values. This paper presents three new methods for determining the onset of AE signals without the need for a predetermined threshold. The performance of the techniques is evaluated using AE signals generated during fatigue crack growth and compared to the established Akaike Information Criterion (AIC) and fixed threshold methods. It was found that the 1D location accuracy of the new methods was within the range of < 1 - 7.1 % of the monitored region compared to 2.7% for the AIC method and a range of 1.8-9.4% for the conventional Fixed Threshold method at different threshold levels.

Wide scanning spherical antenna

NASA Technical Reports Server (NTRS)

Shen, Bing (Inventor); Stutzman, Warren L. (Inventor)

1995-01-01

A novel method for calculating the surface shapes for subreflectors in a suboptic assembly of a tri-reflector spherical antenna system is introduced, modeled from a generalization of Galindo-Israel's method of solving partial differential equations to correct for spherical aberration and provide uniform feed to aperture mapping. In a first embodiment, the suboptic assembly moves as a single unit to achieve scan while the main reflector remains stationary. A feed horn is tilted during scan to maintain the illuminated area on the main spherical reflector fixed throughout the scan thereby eliminating the need to oversize the main spherical reflector. In an alternate embodiment, both the main spherical reflector and the suboptic assembly are fixed. A flat mirror is used to create a virtual image of the suboptic assembly. Scan is achieved by rotating the mirror about the spherical center of the main reflector. The feed horn is tilted during scan to maintain the illuminated area on the main spherical reflector fixed throughout the scan.

Study of magnetic silk fibroin nanoparticles for massage-like transdermal drug delivery

PubMed Central

Chen, Ai-Zheng; Chen, Lin-Qing; Wang, Shi-Bin; Wang, Ya-Qiong; Zha, Jun-Zhe

2015-01-01

A synergistic approach by the combination of magnetic nanoparticles with an alternating magnetic field for transdermal drug delivery was investigated. Methotrexate-loaded silk fibroin magnetic nanoparticles were prepared using suspension-enhanced dispersion by supercritical CO2. The physiochemical properties of the magnetic nanoparticles were characterized. In vitro studies on drug permeation across skin were performed under different magnetic fields in comparison with passive diffusion. The permeation flux enhancement factor was found to increase under a stationary magnetic field, while an alternating magnetic field enhanced drug permeation more effectively; the combination of stationary and alternating magnetic fields, which has a massage-like effect on the skin, achieved the best result. The mechanistic studies using attenuated total reflection Fourier-transform infrared spectroscopy demonstrate that an alternating magnetic field can change the ordered structure of the stratum corneum lipid bilayers from the gel to the lipid-crystalline state, which can increase the fluidity of the stratum corneum lipids, thus enhancing skin penetration. Compared with the other groups, the fluorescence signal with a bigger area detected in deeper regions of the skin also reveals that the simulated massage could enhance the drug permeation across the skin by increasing the follicular transport. The combination of magnetic nanoparticles with stationary/alternating magnetic fields has potential for effective massage-like transdermal drug delivery. PMID:26229467

Disaggregation and separation dynamics of magnetic particles in a microfluidic flow under an alternating gradient magnetic field

NASA Astrophysics Data System (ADS)

Cao, Quanliang; Li, Zhenhao; Wang, Zhen; Qi, Fan; Han, Xiaotao

2018-05-01

How to prevent particle aggregation in the magnetic separation process is of great importance for high-purity separation, while it is a challenging issue in practice. In this work, we report a novel method to solve this problem for improving the selectivity of size-based separation by use of a gradient alternating magnetic field. The specially designed magnetic field is capable of dynamically adjusting the magnetic field direction without changing the direction of magnetic gradient force acting on the particles. Using direct numerical simulations, we show that particles within a certain center-to-center distance are inseparable under a gradient static magnetic field since they are easy aggregated and then start moving together. By contrast, it has been demonstrated that alternating repulsive and attractive interaction forces between particles can be generated to avoid the formation of aggregations when the alternating gradient magnetic field with a given alternating frequency is applied, enabling these particles to be continuously separated based on size-dependent properties. The proposed magnetic separation method and simulation results have the significance for fundamental understanding of particle dynamic behavior and improving the separation efficiency.

In vivo field-cycling relaxometry using an insert coil for magnetic field offset.

PubMed

Pine, Kerrin J; Goldie, Fred; Lurie, David J

2014-11-01

The T(1) of tissue has a strong dependence on the measurement magnetic field strength. T(1) -dispersion could be a useful contrast parameter, but is unavailable to clinical MR systems which operate at fixed magnetic field strength. The purpose of this work was to implement a removable insert magnet coil for field-cycling T(1) -dispersion measurements on a vertical-field MRI scanner, by offsetting the static field over a volume of interest. An insert magnet coil was constructed for use with a whole-body sized 59 milli-Tesla (mT) vertical-field, permanent-magnet based imager. The coil has diameter 38 cm and thickness 6.1 cm and a homogeneous region (± 5%) of 5 cm DSV, offset by 5 cm from the coil surface. Surface radiofrequency (RF) coils were also constructed. The insert coil was used in conjunction with a surface RF coil and a volume-localized inversion-recovery pulse sequence to plot T(1) -dispersion in a human volunteer's forearm over a range of field strengths from 1 mT to 70 mT. T(1) -dispersion measurements were demonstrated on a fixed-field MRI scanner, using an insert coil. This demonstrates the feasibility of relaxation dispersion measurements on an otherwise conventional MR imager, facilitating the exploitation of T(1) -dispersion contrast for enhanced diagnosis. Copyright © 2013 Wiley Periodicals, Inc.

qPCR in gastrointestinal stromal tumors: Evaluation of reference genes and expression analysis of KIT and the alternative receptor tyrosine kinases FLT3, CSF1-R, PDGFRB, MET and AXL

PubMed Central

2010-01-01

Background Gastrointestinal stromal tumors (GIST) represent the most common mesenchymal tumors of the gastrointestinal tract. About 85% carry an activating mutation in the KIT or PDGFRA gene. Approximately 10% of GIST are so-called wild type GIST (wt-GIST) without mutations in the hot spots. In the present study we evaluated appropriate reference genes for the expression analysis of formalin-fixed, paraffin-embedded and fresh frozen samples from gastrointestinal stromal tumors. We evaluated the gene expression of KIT as well as of the alternative receptor tyrosine kinase genes FLT3, CSF1-R, PDGFRB, AXL and MET by qPCR. wt-GIST were compared to samples with mutations in KIT exon 9 and 11 and PDGFRA exon 18 in order to evaluate whether overexpression of these alternative RTK might contribute to the pathogenesis of wt-GIST. Results Gene expression variability of the pooled cDNA samples is much lower than the single reverse transcription cDNA synthesis. By combining the lowest variability values of fixed and fresh tissue, the genes POLR2A, PPIA, RPLPO and TFRC were chosen for further analysis of the GIST samples. Overexpression of KIT compared to the corresponding normal tissue was detected in each GIST subgroup except in GIST with PDGFRA exon 18 mutation. Comparing our sample groups, no significant differences in the gene expression levels of FLT3, CSF1R and AXL were determined. An exception was the sample group with KIT exon 9 mutation. A significantly reduced expression of CSF1R, FLT3 and PDGFRB compared to the normal tissue was detected. GIST with mutations in KIT exon 9 and 11 and in PDGFRA exon 18 showed a significant PDGFRB downregulation. Conclusions As the variability of expression levels for the reference genes is very high comparing fresh frozen and formalin-fixed tissue there is a strong need for validation in each tissue type. None of the alternative receptor tyrosine kinases analyzed is associated with the pathogenesis of wild-type or mutated GIST. It remains to be clarified whether an autocrine or paracrine mechanism by overexpression of receptor tyrosine kinase ligands is responsible for the tumorigenesis of wt-GIST. PMID:21171987

Steep radio spectra in high-redshift radio galaxies

NASA Technical Reports Server (NTRS)

Krolik, Julian H.; Chen, Wan

1991-01-01

The generic spectrum of an optically thin synchrotron source steepens by 0.5 in spectral index from low frequencies to high whenever the source lifetime is greater than the energy-loss timescale for at least some of the radiating electrons. Three effects tend to decrease the frequency nu(b) of this spectral bend as the source redshift increases: (1) for fixed bend frequency nu* in the rest frame, nu(b) = nu*/(1 + z); (2) losses due to inverse Compton scattering the microwave background rise with redshift as (1 + z) exp 4, so that, for fixed residence time in the radiating region, the energy of the lowest energy electron that can cool falls rapidly with increasing redshift; and (3) if the magnetic field is proportional to the equipartition field and the emitting volume is fixed or slowly varying, flux-limited samples induce a selection effect favoring low nu* at high z because higher redshift sources require higher emissivity to be included in the sample, and hence have stronger implied fields and more rapid synchrotron losses. A combination of these effects may explain the trend observed in the 3CR sample for higher redshift radio galaxies to have steeper spectra, and the successful use of ultrasteep spectrum surveys to locate high-redshift galaxies.

Influence of beam efficiency through the patient-specific collimator on secondary neutron dose equivalent in double scattering and uniform scanning modes of proton therapy.

PubMed

Hecksel, D; Anferov, V; Fitzek, M; Shahnazi, K

2010-06-01

Conventional proton therapy facilities use double scattering nozzles, which are optimized for delivery of a few fixed field sizes. Similarly, uniform scanning nozzles are commissioned for a limited number of field sizes. However, cases invariably occur where the treatment field is significantly different from these fixed field sizes. The purpose of this work was to determine the impact of the radiation field conformity to the patient-specific collimator on the secondary neutron dose equivalent. Using a WENDI-II neutron detector, the authors experimentally investigated how the neutron dose equivalent at a particular point of interest varied with different collimator sizes, while the beam spreading was kept constant. The measurements were performed for different modes of dose delivery in proton therapy, all of which are available at the Midwest Proton Radiotherapy Institute (MPRI): Double scattering, uniform scanning delivering rectangular fields, and uniform scanning delivering circular fields. The authors also studied how the neutron dose equivalent changes when one changes the amplitudes of the scanned field for a fixed collimator size. The secondary neutron dose equivalent was found to decrease linearly with the collimator area for all methods of dose delivery. The relative values of the neutron dose equivalent for a collimator with a 5 cm diameter opening using 88 MeV protons were 1.0 for the double scattering field, 0.76 for rectangular uniform field, and 0.6 for the circular uniform field. Furthermore, when a single circle wobbling was optimized for delivery of a uniform field 5 cm in diameter, the secondary neutron dose equivalent was reduced by a factor of 6 compared to the double scattering nozzle. Additionally, when the collimator size was kept constant, the neutron dose equivalent at the given point of interest increased linearly with the area of the scanned proton beam. The results of these experiments suggest that the patient-specific collimator is a significant contributor to the secondary neutron dose equivalent to a distant organ at risk. Improving conformity of the radiation field to the patient-specific collimator can significantly reduce secondary neutron dose equivalent to the patient. Therefore, it is important to increase the number of available generic field sizes in double scattering systems as well as in uniform scanning nozzles.

Agronomic and environmental aspects of diazotrophic bacteria in irrigated rice fields

USDA-ARS?s Scientific Manuscript database

This article provides an overview of the free-living and plant-associated nitrogen-fixing bacterial communities in irrigated rice fields, with a focus on describing the drivers affecting community assemblages in this soil-water-plant-atmosphere system. Theoretical and technical advances in non-legu...

Causality constraints in conformal field theory

DOE PAGES

Hartman, Thomas; Jain, Sachin; Kundu, Sandipan

2016-05-17

Causality places nontrivial constraints on QFT in Lorentzian signature, for example fixing the signs of certain terms in the low energy Lagrangian. In d dimensional conformal field theory, we show how such constraints are encoded in crossing symmetry of Euclidean correlators, and derive analogous constraints directly from the conformal bootstrap (analytically). The bootstrap setup is a Lorentzian four-point function corresponding to propagation through a shockwave. Crossing symmetry fixes the signs of certain log terms that appear in the conformal block expansion, which constrains the interactions of low-lying operators. As an application, we use the bootstrap to rederive the well knownmore » sign constraint on the (Φ) 4 coupling in effective field theory, from a dual CFT. We also find constraints on theories with higher spin conserved currents. As a result, our analysis is restricted to scalar correlators, but we argue that similar methods should also impose nontrivial constraints on the interactions of spinning operators« less

Magnetization Analysis of Magnesium Boride Wires

NASA Astrophysics Data System (ADS)

Cave, J. R.; Zhu, W.

2006-03-01

Cycled applied field magnetization curves contain a wealth of information on critical current density and flux pinning that is not commonly exploited. Detailed magnetization data for magnesium boride wire cores have been analyzed for critical state model consistency. The iron-sheathed silicon nitride doped magnesium boride wires were prepared from pure magnesium and boron powders with nano-scale silicon nitride additions (MgB2-x(Si3N4)x/7 with x = 0 - 0.4). A subsequent short annealing heat treatment, 800 degrees C and of 1 hour duration in Argon, was applied to create the desired phase. Magnetization critical current densities were up to ˜340 kA/cm2 at 5K and 1T. Major and minor loop analysis will be described, for field sweeps up to 3 tesla at fixed temperatures and for temperature sweeps from 5K to 45K in fixed fields, with respect to parameters describing the critical state model.

Maximizing the potential of direct aperture optimization through collimator rotation

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

Milette, Marie-Pierre; Otto, Karl; Medical Physics, BC Cancer Agency-Vancouver Centre, Vancouver, British Columbia

Intensity-modulated radiation therapy (IMRT) treatment plans are conventionally produced by the optimization of fluence maps followed by a leaf sequencing step. An alternative to fluence based inverse planning is to optimize directly the leaf positions and field weights of multileaf collimator (MLC) apertures. This approach is typically referred to as direct aperture optimization (DAO). It has been shown that equivalent dose distributions may be generated that have substantially fewer monitor units (MU) and number of apertures compared to fluence based optimization techniques. Here we introduce a DAO technique with rotated apertures that we call rotating aperture optimization (RAO). The advantagesmore » of collimator rotation in IMRT have been shown previously and include higher fluence spatial resolution, increased flexibility in the generation of aperture shapes and less interleaf effects. We have tested our RAO algorithm on a complex C-shaped target, seven nasopharynx cancer recurrences, and one multitarget nasopharynx carcinoma patient. A study was performed in order to assess the capabilities of RAO as compared to fixed collimator angle DAO. The accuracy of fixed and rotated collimator aperture delivery was also verified. An analysis of the optimized treatment plans indicates that plans generated with RAO are as good as or better than DAO while maintaining a smaller number of apertures and MU than fluence based IMRT. Delivery verification results show that RAO is less sensitive to tongue and groove effects than DAO. Delivery time is currently increased due to the collimator rotation speed although this is a mechanical limitation that can be eliminated in the future.« less

Microencapsulation by spray drying of nitrogen-fixing bacteria associated with lupin nodules.

PubMed

Campos, Daniela C; Acevedo, Francisca; Morales, Eduardo; Aravena, Javiera; Amiard, Véronique; Jorquera, Milko A; Inostroza, Nitza G; Rubilar, Mónica

2014-09-01

Plant growth promoting bacteria and nitrogen-fixing bacteria (NFB) used for crop inoculation have important biotechnological potential as a sustainable fertilization tool. However, the main limitation of this technology is the low inoculum survival rate under field conditions. Microencapsulation of bacterial cells in polymer matrices provides a controlled release and greater protection against environmental conditions. In this context, the aim of this study was to isolate and characterize putative NFB associated with lupin nodules and to evaluate their microencapsulation by spray drying. For this purpose, 21 putative NFB were isolated from lupin nodules and characterized (16S rRNA genes). Microencapsulation of bacterial cells by spray drying was studied using a mixture of sodium alginate:maltodextrin at different ratios (0:15, 1:14, 2:13) and concentrations (15 and 30% solids) as the wall material. The microcapsules were observed under scanning electron microscopy to verify their suitable morphology. Results showed the association between lupin nodules of diverse known NFB and nodule-forming bacteria belonging to Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria and Bacteroidetes. In microencapsulation assays, the 1:14 ratio of sodium alginate:maltodextrin (15% solids) showed the highest cell survival rate (79%), with a microcapsule yield of 27% and spherical microcapsules of 5-50 µm in diameter. In conclusion, diverse putative NFB genera and nodule-forming bacteria are associated with the nodules of lupine plants grown in soils in southern Chile, and their microencapsulation by spray drying using sodium alginate:maltodextrin represents a scalable process to generate a biofertilizer as an alternative to traditional nitrogen fertilization.

Study on the effect of magnetic field treatment of newly isolated Paenibacillus sp.

PubMed

Li, Jie; Yi, Yanli; Cheng, Xilei; Zhang, Dageng; Irfan, Muhammad

2015-12-01

Symbiotic nitrogen fixation in plants occurs in roots with the help of some bacteria which help in soil nitrogen fertility management. Isolation of significant environment friendly bacteria for nitrogen fixation is very important to enhance yield in plants. In this study effect of different magnetic field intensity and treatment time was studied on the morphology, physiology and nitrogen fixing capacity of newly isolated Paenibaccilus sp. from brown soil. The bacterium was identified by 16S rDNA sequence having highest similarity (99%) with Paenibacillus sp as revealed by BLAST. Different magnetic intensities such as 100mT, 300mT and 500mT were applied with processing time of 0, 5, 10, 20 and 30 minutes. Of all these treatment 300mT with processing time of 10 minutes was found to be most suitable treatment. Results revealed that magnetic treatment improve the growth rate with shorter generation time leading to increased enzyme activities (catalase, peroxidase and superoxide dismutase) and nitrogen fixing efficiencies. High magnetic field intensity (500mT) caused ruptured cell morphology and decreased enzyme activities which lead to less nitrogen fixation. It is concluded that appropriate magnetic field intensity and treatment time play a vital role in the growth of soil bacteria which increases the nitrogen fixing ability which affects the yield of plant. These results were very helpful in future breading programs to enhance the yield of soybean.

Connections between the Sznajd model with general confidence rules and graph theory

NASA Astrophysics Data System (ADS)

Timpanaro, André M.; Prado, Carmen P. C.

2012-10-01

The Sznajd model is a sociophysics model that is used to model opinion propagation and consensus formation in societies. Its main feature is that its rules favor bigger groups of agreeing people. In a previous work, we generalized the bounded confidence rule in order to model biases and prejudices in discrete opinion models. In that work, we applied this modification to the Sznajd model and presented some preliminary results. The present work extends what we did in that paper. We present results linking many of the properties of the mean-field fixed points, with only a few qualitative aspects of the confidence rule (the biases and prejudices modeled), finding an interesting connection with graph theory problems. More precisely, we link the existence of fixed points with the notion of strongly connected graphs and the stability of fixed points with the problem of finding the maximal independent sets of a graph. We state these results and present comparisons between the mean field and simulations in Barabási-Albert networks, followed by the main mathematical ideas and appendices with the rigorous proofs of our claims and some graph theory concepts, together with examples. We also show that there is no qualitative difference in the mean-field results if we require that a group of size q>2, instead of a pair, of agreeing agents be formed before they attempt to convince other sites (for the mean field, this would coincide with the q-voter model).

Simulations of string vibrations with boundary conditions of third kind using the functional transformation method

NASA Astrophysics Data System (ADS)

Trautmann, L.; Petrausch, S.; Bauer, M.

2005-09-01

The functional transformation method (FTM) is an established mathematical method for accurate simulation of multidimensional physical systems from various fields of science, including optics, heat and mass transfer, electrical engineering, and acoustics. It is a frequency-domain method based on the decomposition into eigenvectors and eigenfrequencies of the underlying physical problem. In this article, the FTM is applied to real-time simulations of vibrating strings which are ideally fixed at one end while the fixing at the other end is modeled by a frequency-dependent input impedance. Thus, boundary conditions of third kind are applied to the model at the end fixed with the input impedance. It is shown that accurate and stable simulations are achieved with nearly the same computational cost as with strings ideally fixed at both ends.

Subjective value of risky foods for individual domestic chicks: a hierarchical Bayesian model.

PubMed

Kawamori, Ai; Matsushima, Toshiya

2010-05-01

For animals to decide which prey to attack, the gain and delay of the food item must be integrated in a value function. However, the subjective value is not obtained by expected profitability when it is accompanied by risk. To estimate the subjective value, we examined choices in a cross-shaped maze with two colored feeders in domestic chicks. When tested by a reversal in food amount or delay, chicks changed choices similarly in both conditions (experiment 1). We therefore examined risk sensitivity for amount and delay (experiment 2) by supplying one feeder with food of fixed profitability and the alternative feeder with high- or low-profitability food at equal probability. Profitability varied in amount (groups 1 and 2 at high and low variance) or in delay (group 3). To find the equilibrium, the amount (groups 1 and 2) or delay (group 3) of the food in the fixed feeder was adjusted in a total of 18 blocks. The Markov chain Monte Carlo method was applied to a hierarchical Bayesian model to estimate the subjective value. Chicks undervalued the variable feeder in group 1 and were indifferent in group 2 but overvalued the variable feeder in group 3 at a population level. Re-examination without the titration procedure (experiment 3) suggested that the subjective value was not absolute for each option. When the delay was varied, the variable option was often given a paradoxically high value depending on fixed alternative. Therefore, the basic assumption of the uniquely determined value function might be questioned.

Volumetric-modulated arc therapy (RapidArc) vs. conventional fixed-field intensity-modulated radiotherapy for {sup 18}F-FDG-PET-guided dose escalation in oropharyngeal cancer: A planning study

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

Teoh, May, E-mail: m.teoh@nhs.net; Beveridge, Sabeena; Wood, Katie

2013-04-01

Fluorine-18-fluorodeoxyglucose-positron emission tomography ({sup 18}F-FDG-PET)–guided focal dose escalation in oropharyngeal cancer may potentially improve local control. We evaluated the feasibility of this approach using volumetric-modulated arc therapy (RapidArc) and compared these plans with fixed-field intensity-modulated radiotherapy (IMRT) focal dose escalation plans. Materials and methods: An initial study of 20 patients compared RapidArc with fixed-field IMRT using standard dose prescriptions. From this cohort, 10 were included in a dose escalation planning study. Dose escalation was applied to {sup 18}F-FDG-PET–positive regions in the primary tumor at dose levels of 5% (DL1), 10% (DL2), and 15% (DL3) above standard radical dose (65 Gymore » in 30 fractions). Fixed-field IMRT and double-arc RapidArc plans were generated for each dataset. Dose-volume histograms were used for plan evaluation and comparison. The Paddick conformity index (CI{sub Paddick}) and monitor units (MU) for each plan were recorded and compared. Both IMRT and RapidArc produced clinically acceptable plans and achieved planning objectives for target volumes. Dose conformity was significantly better in the RapidArc plans, with lower CI{sub Paddick} scores in both primary (PTV1) and elective (PTV2) planning target volumes (largest difference in PTV1 at DL3; 0.81 ± 0.03 [RapidArc] vs. 0.77 ± 0.07 [IMRT], p = 0.04). Maximum dose constraints for spinal cord and brainstem were not exceeded in both RapidArc and IMRT plans, but mean doses were higher with RapidArc (by 2.7 ± 1 Gy for spinal cord and 1.9 ± 1 Gy for brainstem). Contralateral parotid mean dose was lower with RapidArc, which was statistically significant at DL1 (29.0 vs. 29.9 Gy, p = 0.01) and DL2 (29.3 vs. 30.3 Gy, p = 0.03). MU were reduced by 39.8–49.2% with RapidArc (largest difference at DL3, 641 ± 94 vs. 1261 ± 118, p < 0.01). {sup 18}F-FDG-PET–guided focal dose escalation in oropharyngeal cancer is feasible with RapidArc. Compared with conventional fixed-field IMRT, RapidArc can achieve better dose conformity, improve contralateral parotid sparing, and uses fewer MU.« less

Solution of effective Hamiltonian of impurity hopping between two sites in a metal

NASA Astrophysics Data System (ADS)

Ye, Jinwu

1998-03-01

We analyze in detail all the possible fixed points of the effective Hamiltonian of a non-magnetic impurity hopping between two sites in a metal obtained by Moustakas and Fisher(MF). We find a line of non-fermi liquid fixed points which continuously interpolates between the 2-channel Kondo fixed point(2CK) and the one channel, two impurity Kondo (2IK) fixed point. There is one relevant direction with scaling dimension 1/2 and one leading irrelevant operator with dimension 3/2. There is also one marginal operator in the spin sector moving along this line. The additional non-fermi liquid fixed point found by MF has the same symmetry as the 2IK, it has two relevant directions with scaling dimension 1/2, therefore also unstable. The system is shown to flow to a line of fermi-liquid fixed points which continuously interpolates between the non-interacting fixed point and the 2 channel spin-flavor Kondo fixed point (2CSFK) discussed by the author previously. The effect of particle-hole symmetry breaking is discussed. The effective Hamiltonian in the external magnetic field is analysed. The scaling functions for the physical measurable quantities are derived in the different regimes; their predictions for the experiments are given. Finally the implications are given for a non-magnetic impurity hopping around three sites with triangular symmetry discussed by MF.

Fiber optic submarine cables cuts cost modeling and cable protection aspects

NASA Astrophysics Data System (ADS)

Al-Lawati, Ali

2015-03-01

This work presents a model to calculate costs associated with submarine fiber optic cable cuts. It accounts for both fixed and variable factors determining cost of fixing cables and restoring data transmission. It considers duration of a cut, capacity of fibers, number of fiber pairs and expected number of cuts during cable life time. Moreover, it provides templates for initial feasibility assessments by comparing cut costs to cost of different cable protection schemes. It offers a needed tool to assist in guiding decision makers in selecting type of cable, length and depth of cable burial in terms of increase in initial investment due to adapting such protection methods, and compare it to cost of cuts repair and alternative restoration paths for data.

Practicality of electronic beam steering for MST/ST radars, part 6.2A

NASA Technical Reports Server (NTRS)

Clark, W. L.; Green, J. L.

1984-01-01

Electronic beam steering is described as complex and expensive. The Sunset implementation of electronic steering is described, and it is demonstrated that such systems are cost effective, versatile, and no more complex than fixed beam alternatives, provided three or more beams are needed. The problem of determining accurate meteorological wind components in the presence of spatial variation is considered. A cost comparison of steerable and fixed systems allowing solution of this problem is given. The concepts and relations involved in phase steering are given, followed by the description of the Sunset ST radar steering system. The implications are discussed, references to the competing SAD method are provided, and a recommendation concerning the design of the future Doppler ST/MST systems is made.

A Novel Method of Localization for Moving Objects with an Alternating Magnetic Field

PubMed Central

Gao, Xiang; Yan, Shenggang; Li, Bin

2017-01-01

Magnetic detection technology has wide applications in the fields of geological exploration, biomedical treatment, wreck removal and localization of unexploded ordinance. A large number of methods have been developed to locate targets with static magnetic fields, however, the relation between the problem of localization of moving objectives with alternating magnetic fields and the localization with a static magnetic field is rarely studied. A novel method of target localization based on coherent demodulation was proposed in this paper. The problem of localization of moving objects with an alternating magnetic field was transformed into the localization with a static magnetic field. The Levenberg-Marquardt (L-M) algorithm was applied to calculate the position of the target with magnetic field data measured by a single three-component magnetic sensor. Theoretical simulation and experimental results demonstrate the effectiveness of the proposed method. PMID:28430153

Intelligence/Electronic Warfare (IEW) direction-finding and fix estimation analysis report. Volume 2: Trailblazer

NASA Technical Reports Server (NTRS)

Gardner, Robert; Gillis, James W.; Griesel, Ann; Pardo, Bruce

1985-01-01

An analysis of the direction finding (DF) and fix estimation algorithms in TRAILBLAZER is presented. The TRAILBLAZER software analyzed is old and not currently used in the field. However, the algorithms analyzed are used in other current IEW systems. The underlying algorithm assumptions (including unmodeled errors) are examined along with their appropriateness for TRAILBLAZER. Coding and documentation problems are then discussed. A detailed error budget is presented.

Field test of an alternative longwall gate road design

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

Cox, R.M.; Vandergrift, T.L.; McDonnell, J.P.

1994-01-01

The US Bureau of Mines (USBM) MULSIM/ML modeling technique has been used to analyze anticipated stress distributions for a proposed alternative longwall gate road design for a western Colorado coal mine. The model analyses indicated that the alternative gate road design would reduce stresses in the headgate entry. To test the validity of the alternative gate road design under actual mining conditions, a test section of the alternative system was incorporated into a subsequent set of gate roads developed at the mine. The alternative gate road test section was instrumented with borehole pressure cells, as part of an ongoing USBMmore » research project to monitor ground pressure changes as longwall mining progressed. During the excavation of the adjacent longwall panels, the behavior of the alternative gate road system was monitored continuously using the USBM computer-assisted Ground Control Management System. During these field tests, the alternative gate road system was first monitored and evaluated as a headgate, and later monitored and evaluated as a tailgate. The results of the field tests confirmed the validity of using the MULSIM/NL modeling technique to evaluate mine designs.« less

Deletions of the SACPD-C locus elevate seed stearic acid levels but also result in fatty acid and morphological alterations in nitrogen fixing nodules

USDA-ARS?s Scientific Manuscript database

Soybean (Glycine max) seeds are the primary source of edible oil in the United States. Despite its widespread utility, soybean oil is oxidatively unstable. Until recently, the majority of soybean oil underwent chemical hydrogenation, a process which generates trans fats. An alternative to chemical h...

Alternative supply specifications and estimates of regional supply and demand for stumpage.

Treesearch

Kent P. Connaughton; David H. Jackson; Gerard A. Majerus

1988-01-01

Four plausible sets of stumpage supply and demand equations were developed and estimated; the demand equation was the same for each set, although the supply equation differed. The supply specifications varied from the model of regional excess demand in which National Forest harvest levels were assumed fixed to a more realistic model in which the harvest on the National...

The Dominance Concept Inventory: A Tool for Assessing Undergraduate Student Alternative Conceptions about Dominance in Mendelian and Population Genetics

ERIC Educational Resources Information Center

Abraham, Joel K.; Perez, Kathryn E.; Price, Rebecca M.

2014-01-01

Despite the impact of genetics on daily life, biology undergraduates understand some key genetics concepts poorly. One concept requiring attention is dominance, which many students understand as a fixed property of an allele or trait and regularly conflate with frequency in a population or selective advantage. We present the Dominance Concept…

78 FR 29615 - Establishment of Area Navigation (RNAV) Routes; Washington, DC

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-21

...). Q-72 extends between the HACKS, WV, intersection and the RAMAY, VA, WP. It provides an alternate route for jet route J-149 via a direct routing to the HACKS intersection, thus reducing miles flown for...]12'20'' W.) Q72 HACKS, WV to RAMAY, VA [New] HACKS, WV FIX (Lat. 39[deg]07'46'' N., long. 081[deg]05...

A new suture technique avoids rib fractures and intercostal nerve trauma in thoracotomy.

PubMed

Huang, Biaotong

2014-12-01

This article describes an alternative suture technique for thoracotomy incisions. A modified mattress suture technique is used to fix the intercostal muscles. The described technique can prevent rib fractures and reduce the incidence of intercostal nerve injury. Also, this technique is easy to perform and is effective. Georg Thieme Verlag KG Stuttgart · New York.

Planning Alternative Organizational Frameworks For a Large Scale Educational Telecommunications System Served by Fixed/Broadcast Satellites. Memorandum Number 73/3.

ERIC Educational Resources Information Center

Walkmeyer, John

Considerations relating to the design of organizational structures for development and control of large scale educational telecommunications systems using satellites are explored. The first part of the document deals with four issues of system-wide concern. The first is user accessibility to the system, including proximity to entry points, ability…

Random preferences towards bioenergy environmental externalities: a case study of woody biomass based electricity in the Southern United States

Treesearch

Andres Susaeta; Pankaj Lal; Janaki Alavalapati; Evan Mercer

2011-01-01

This paper contrasts alternate methodological approaches of investigating public preferences, the random parameter logit (RPL) where tastes and preferences of respondents are assumed to be heterogeneous and the conditional logit (CL) approach where tastes and preferences remain fixed for individuals. We conducted a choice experiment to assess preferences for woody...

77 FR 3017 - Self-Regulatory Organizations; C2 Options Exchange, Incorporated; Notice of Filing and Immediate...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-20

... be charged on a per-Login ID basis. Firms may access C2 via either a CMI Client Application [[Page..., using different Login IDs, accessing the same CMI Client Application Server or FIX Port, allowing the firm to only pay the monthly fee once. Alternatively, a firm may use the same Login ID to access...

Choice Inconsistencies among the Elderly: Evidence from Plan Choice in the Medicare Part D Program: Reply

PubMed Central

ABALUCK, JASON

2017-01-01

We explore the in- and out- of sample robustness of tests for choice inconsistencies based on parameter restrictions in parametric models, focusing on tests proposed by Ketcham, Kuminoff and Powers (KKP). We argue that their non-parametric alternatives are inherently conservative with respect to detecting mistakes. We then show that our parametric model is robust to KKP’s suggested specification checks, and that comprehensive goodness of fit measures perform better with our model than the expected utility model. Finally, we explore the robustness of our 2011 results to alternative normative assumptions highlighting the role of brand fixed effects and unobservable characteristics. PMID:29170561

Rectal methadone in cancer patients with pain. A preliminary clinical and pharmacokinetic study.

PubMed

Ripamonti, C; Zecca, E; Brunelli, C; Rizzio, E; Saita, L; Lodi, F; De Conno, F

1995-10-01

Cancer pain can be treated in most cases with oral analgesics. However, during their clinical history, 53% to 70% of patients will need alternative routes of opioid administration. The rectal administration of opioids is a simple alternative route for many patients. There are no data in the literature regarding the pharmacodynamics and pharmacokinetics of rectal methadone. We evaluated the analgesia, tolerability and absorption profile of methadone hydrochloride in six opioid-naive cancer patients with pain. A blood sample was collected before administration of a single dose of drug (10 mg) and then again after fixed times. At these fixed times the patients were asked about pain, nausea and drowsiness by means of a visual analogue scale of 0-100 mm (VAS). Pain relief was statistically significant as early as 30 minutes and up to eight hours after methadone administration. None of the patients reported significant side effects. The pharmacokinetics of rectal methadone showed rapid and extensive distribution phases followed by a slow elimination phase. Rectal methadone can be considered an effective analgesic therapy for patients with cancer pain for whom oral and/or parenteral opioids are not indicated or available.

The role of the carbohydrate chains in complement (C3) fixation by solid-phase-bound human IgA.

PubMed Central

Nikolova, E B; Tomana, M; Russell, M W

1994-01-01

In contrast to antigen-antibody complexes containing native human IgA, solid-phase-deposited IgA activates the alternative complement pathway and binds C3b. To investigate the role of carbohydrate chains in this, various human IgA preparations were treated with neuraminidase alone or together with N-glycanase or O-glycanase, or with mixed glycosidases from the oral bacterium, Streptococcus mitis. Depletion of oligosaccharides was determined by carbohydrate analysis. Removal of sialic acid and N-linked glycan chains greatly increased the C3b-fixing properties of normal serum IgA1 and IgA2. Myeloma IgA1 and IgA2 proteins and secretory IgA had higher C3b-binding activity than normal serum IgA, and this was further increased by removal of sialic acid and N-linked glycans. Fc alpha and Fc alpha-SC fragments of myeloma and secretory IgA1, respectively, but not Fab alpha fragments, obtained by cleavage with bacterial IgA1 proteases and also free secretory component, fixed C3b by the alternative pathway. Images Figure 4 PMID:7927504

BRST-BV approach to continuous-spin field

NASA Astrophysics Data System (ADS)

Metsaev, R. R.

2018-06-01

Using BRST-BV approach, massless and massive continuous-spin fields propagating in the flat space are studied. For such fields, BRST-BV gauge invariant Lagrangian is obtained. The Lagrangian and gauge transformations are constructed out of traceless gauge fields and traceless gauge transformation parameters. Interrelation between the BRST-BV Lagrangian and the Lagrangian for the continuous-spin fields in metric-like approach is demonstrated. Considering the BRST-BV Lagrangian in the Siegel gauge, we get gauge-fixed Lagrangian which is invariant under global BRST and antiBRST transformations.

How good a clock is rotation? The stellar rotation-mass-age relationship for old field stars

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

Epstein, Courtney R.; Pinsonneault, Marc H., E-mail: epstein@astronomy.ohio-state.edu, E-mail: pinsono@astronomy.ohio-state.edu

2014-01-10

The rotation-mass-age relationship offers a promising avenue for measuring the ages of field stars, assuming the attendant uncertainties to this technique can be well characterized. We model stellar angular momentum evolution starting with a rotation distribution from open cluster M37. Our predicted rotation-mass-age relationship shows significant zero-point offsets compared to an alternative angular momentum loss law and published gyrochronology relations. Systematic errors at the 30% level are permitted by current data, highlighting the need for empirical guidance. We identify two fundamental sources of uncertainty that limit the precision of rotation-based ages and quantify their impact. Stars are born with amore » range of rotation rates, which leads to an age range at fixed rotation period. We find that the inherent ambiguity from the initial conditions is important for all young stars, and remains large for old stars below 0.6 M {sub ☉}. Latitudinal surface differential rotation also introduces a minimum uncertainty into rotation period measurements and, by extension, rotation-based ages. Both models and the data from binary star systems 61 Cyg and α Cen demonstrate that latitudinal differential rotation is the limiting factor for rotation-based age precision among old field stars, inducing uncertainties at the ∼2 Gyr level. We also examine the relationship between variability amplitude, rotation period, and age. Existing ground-based surveys can detect field populations with ages as old as 1-2 Gyr, while space missions can detect stars as old as the Galactic disk. In comparison with other techniques for measuring the ages of lower main sequence stars, including geometric parallax and asteroseismology, rotation-based ages have the potential to be the most precise chronometer for 0.6-1.0 M {sub ☉} stars.« less

Magneto-thermal-acoustic differential-frequency imaging of magnetic nanoparticle with magnetic spatial localization: a theoretical prediction

NASA Astrophysics Data System (ADS)

Piao, Daqing

2017-02-01

The magneto-thermo-acoustic effect that we predicted in 2013 refers to the generation of acoustic-pressure wave from magnetic nanoparticle (MNP) when thermally mediated under an alternating magnetic field (AMF) at a pulsed or frequency-chirped application. Several independent experimental studies have since validated magneto-thermoacoustic effect, and a latest report has discovered acoustic-wave generation from MNP at the second-harmonic frequency of the AMF when operating continuously. We propose that applying two AMFs with differing frequencies to MNP will produce acoustic-pressure wave at the summation and difference of the two frequencies, in addition to the two second-harmonic frequencies. Analysis of the specific absorption dynamics of the MNP when exposed to two AMFs of differing frequencies has shown some interesting patterns of acoustic-intensity at the multiple frequency components. The ratio of the acoustic-intensity at the summation-frequency over that of the difference-frequency is determined by the frequency-ratio of the two AMFs, but remains independent of the AMF strengths. The ratio of the acoustic-intensity at the summation- or difference-frequency over that at each of the two second-harmonic frequencies is determined by both the frequency-ratio and the field-strength-ratio of the two AMFs. The results indicate a potential strategy for localization of the source of a continuous-wave magneto-thermalacoustic signal by examining the frequency spectrum of full-field non-differentiating acoustic detection, with the field-strength ratio changed continuously at a fixed frequency-ratio. The practicalities and challenges of this magnetic spatial localization approach for magneto-thermo-acoustic imaging using a simple envisioned set of two AMFs arranged in parallel to each other are discussed.

Electric Field Induced Interfacial Instabilities

NASA Technical Reports Server (NTRS)

Kusner, Robert E.; Min, Kyung Yang; Wu, Xiao-lun; Onuki, Akira

1999-01-01

The study of the interface in a charge-free, critical and near-critical binary fluid in the presence of an externally applied electric field is presented. At sufficiently large fields, the interface between the two phases of the binary fluid should become unstable and exhibit an undulation with a predefined wavelength on the order of the capillary length. As the critical point is approached, this wavelength is reduced, potentially approaching length-scales such as the correlation length or critical nucleation radius. At this point the critical properties of the system may be affected. In this paper, the flat interface of a marginally polar binary fluid mixture is stressed by a perpendicular alternating electric field and the resulting instability is characterized by the critical electric field E(sub c) and the pattern observed. The character of the surface dynamics at the onset of instability is found to be strongly dependent on the frequency f of the field applied. The plot of E(sub c) vs. f for a fixed temperature shows a sigmoidal shape, whose low and high frequency limits are well described by a power-law relationship, E(sub c) = epsilon(exp zeta) with zeta = 0.35 and zeta = 0.08, respectively. The low-limit exponent compares well with the value zeta = 4 for a system of conducting and non-conducting fluids. On the other hand, the high-limit exponent coincides with what was first predicted by Onuki. The instability manifests itself as the conducting phase penetrates the non-conducting phase. As the frequency increases, the shape of the pattern changes from an array of bifurcating strings to an array of column-like (or rod-like) protrusions, each of which spans the space between the plane interface and one of the electrodes. For an extremely high frequency, the disturbance quickly grows into a parabolic cone pointing toward the upper plate. As a result, the interface itself changes its shape from that of a plane to that of a high sloping pyramid.

Optimal impulsive time-fixed orbital rendezvous and interception with path constraints

NASA Technical Reports Server (NTRS)

Taur, D.-R.; Prussing, J. E.; Coverstone-Carroll, V.

1990-01-01

Minimum-fuel, impulsive, time-fixed solutions are obtained for the problem of orbital rendezvous and interception with interior path constraints. Transfers between coplanar circular orbits in an inverse-square gravitational field are considered, subject to a circular path constraint representing a minimum or maximum permissible orbital radius. Primer vector theory is extended to incorporate path constraints. The optimal number of impulses, their times and positions, and the presence of initial or final coasting arcs are determined. The existence of constraint boundary arcs and boundary points is investigated as well as the optimality of a class of singular arc solutions. To illustrate the complexities introduced by path constraints, an analysis is made of optimal rendezvous in field-free space subject to a minimum radius constraint.

Speckle-field digital holographic microscopy.

PubMed

Park, YongKeun; Choi, Wonshik; Yaqoob, Zahid; Dasari, Ramachandra; Badizadegan, Kamran; Feld, Michael S

2009-07-20

The use of coherent light in conventional holographic phase microscopy (HPM) poses three major drawbacks: poor spatial resolution, weak depth sectioning, and fixed pattern noise due to unwanted diffraction. Here, we report a technique which can overcome these drawbacks, but maintains the advantage of phase microscopy - high contrast live cell imaging and 3D imaging. A speckle beam of a complex spatial pattern is used for illumination to reduce fixed pattern noise and to improve optical sectioning capability. By recording of the electric field of speckle, we demonstrate high contrast 3D live cell imaging without the need for axial scanning - neither objective lens nor sample stage. This technique has great potential in studying biological samples with improved sensitivity, resolution and optical sectioning capability.

Theoretical study of the dynamic magnetic response of ferrofluid to static and alternating magnetic fields

NASA Astrophysics Data System (ADS)

Batrudinov, Timur M.; Ambarov, Alexander V.; Elfimova, Ekaterina A.; Zverev, Vladimir S.; Ivanov, Alexey O.

2017-06-01

The dynamic magnetic response of ferrofluid in a static uniform external magnetic field to a weak, linear polarized, alternating magnetic field is investigated theoretically. The ferrofluid is modeled as a system of dipolar hard spheres, suspended in a long cylindrical tube whose long axis is parallel to the direction of the static and alternating magnetic fields. The theory is based on the Fokker-Planck-Brown equation formulated for the case when the both static and alternating magnetic fields are applied. The solution of the Fokker-Planck-Brown equation describing the orientational probability density of a randomly chosen dipolar particle is expressed as a series in terms of the spherical Legendre polynomials. The obtained analytical expression connecting three neighboring coefficients of the series makes possible to determine the probability density with any order of accuracy in terms of Legendre polynomials. The analytical formula for the probability density truncated at the first Legendre polynomial is evaluated and used for the calculation of the magnetization and dynamic susceptibility spectra. In the absence of the static magnetic field the presented theory gives the correct single-particle Debye-theory result, which is the exact solution of the Fokker-Planck-Brown equation for the case of applied weak alternating magnetic field. The influence of the static magnetic field on the dynamic susceptibility is analyzed in terms of the low-frequency behavior of the real part and the position of the peak in the imaginary part.

Retained Austenite in SAE 52100 Steel Post Magnetic Processing and Heat Treatment

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

Pappas, Nathaniel R; Watkins, Thomas R; Cavin, Odis Burl

2007-01-01

Steel is an iron-carbon alloy that contains up to 2% carbon by weight. Understanding which phases of iron and carbon form as a function of temperature and percent carbon is important in order to process/manufacture steel with desired properties. Austenite is the face center cubic (fcc) phase of iron that exists between 912 and 1394 C. When hot steel is rapidly quenched in a medium (typically oil or water), austenite transforms into martensite. The goal of the study is to determine the effect of applying a magnetic field on the amount of retained austenite present at room temperature after quenching.more » Samples of SAE 52100 steel were heat treated then subjected to a magnetic field of varying strength and time, while samples of SAE 1045 steel were heat treated then subjected to a magnetic field of varying strength for a fixed time while being tempered. X-ray diffraction was used to collect quantitative data corresponding to the amount of each phase present post processing. The percentage of retained austenite was then calculated using the American Society of Testing and Materials standard for determining the amount of retained austenite for randomly oriented samples and was plotted as a function of magnetic field intensity, magnetic field apply time, and magnetic field wait time after quenching to determine what relationships exist with the amount of retained austenite present. In the SAE 52100 steel samples, stronger field strengths resulted in lower percentages of retained austenite for fixed apply times. The results were inconclusive when applying a fixed magnetic field strength for varying amounts of time. When applying a magnetic field after waiting a specific amount of time after quenching, the analyses indicate that shorter wait times result in less retained austenite. The SAE 1045 results were inconclusive. The samples showed no retained austenite regardless of magnetic field strength, indicating that tempering removed the retained austenite. It is apparent that applying a magnetic field after quenching will result in a lower amount of retained austenite but that the exact relationship, linear or other, is inconclusive. This project is a part of a larger, ongoing project investigating the application of a magnetic field during heat treatment and its influence on the iron-carbon phase-equilibria.« less

A unified monolithic approach for multi-fluid flows and fluid-structure interaction using the Particle Finite Element Method with fixed mesh

NASA Astrophysics Data System (ADS)

Becker, P.; Idelsohn, S. R.; Oñate, E.

2015-06-01

This paper describes a strategy to solve multi-fluid and fluid-structure interaction (FSI) problems using Lagrangian particles combined with a fixed finite element (FE) mesh. Our approach is an extension of the fluid-only PFEM-2 (Idelsohn et al., Eng Comput 30(2):2-2, 2013; Idelsohn et al., J Numer Methods Fluids, 2014) which uses explicit integration over the streamlines to improve accuracy. As a result, the convective term does not appear in the set of equations solved on the fixed mesh. Enrichments in the pressure field are used to improve the description of the interface between phases.

The Frame of Fixed Stars in Relational Mechanics

NASA Astrophysics Data System (ADS)

Ferraro, Rafael

2017-01-01

Relational mechanics is a gauge theory of classical mechanics whose laws do not govern the motion of individual particles but the evolution of the distances between particles. Its formulation gives a satisfactory answer to Leibniz's and Mach's criticisms of Newton's mechanics: relational mechanics does not rely on the idea of an absolute space. When describing the behavior of small subsystems with respect to the so called "fixed stars", relational mechanics basically agrees with Newtonian mechanics. However, those subsystems having huge angular momentum will deviate from the Newtonian behavior if they are described in the frame of fixed stars. Such subsystems naturally belong to the field of astronomy; they can be used to test the relational theory.

A framework for an alternatives assessment dashboard for evaluating chemical alternatives applied to flame retardants for electronic applications.

PubMed

Martin, Todd M

2017-05-01

The goal of alternatives assessment (AA) is to facilitate a comparison of alternatives to a chemical of concern, resulting in the identification of safer alternatives. A two stage methodology for comparing chemical alternatives was developed. In the first stage, alternatives are compared using a variety of human health effects, ecotoxicity, and physicochemical properties. Hazard profiles are completed using a variety of online sources and quantitative structure activity relationship models. In the second stage, alternatives are evaluated utilizing an exposure/risk assessment over the entire life cycle. Exposure values are calculated using screening-level near-field and far-field exposure models. The second stage allows one to more accurately compare potential exposure to each alternative and consider additional factors that may not be obvious from separate binned persistence, bioaccumulation, and toxicity scores. The methodology was utilized to compare phosphate-based alternatives for decabromodiphenyl ether (decaBDE) in electronics applications.

Camouflage of moderate Class III malocclusions with extraction of lower second molars and mandibular cervical headgear.

PubMed

Mora, Diego Rey; Oberti, Giovanni; Ealo, Martha; Baccetti, Tiziano

2007-01-01

Orthodontic camouflage in patients with slight or moderate skeletal Class III malocclusions, can be obtained through different treatment alternatives. The purpose of this paper is to present a treatment that has not been described in the literature and which consists of the extraction of lower second molars and distal movement of the posterior segments by means of mandibular cervical headgear (MCH) and fixed appliances as a camouflage alternative. The force applied by the MCH was 250 gr per side (14hr/day). The total treatment time was 1 1/2 years. the extraction of lower second molars along with the use of mandibular cervical headgear is a good treatment alternative for camouflage in moderate Class III patients in order to obtain good occlusal relationships without affecting facial esthetics or producing marked dental compensations.

Linear and Non-Linear Dielectric Response of Periodic Systems from Quantum Monte Carlo

NASA Astrophysics Data System (ADS)

Umari, Paolo

2006-03-01

We present a novel approach that allows to calculate the dielectric response of periodic systems in the quantum Monte Carlo formalism. We employ a many-body generalization for the electric enthalpy functional, where the coupling with the field is expressed via the Berry-phase formulation for the macroscopic polarization. A self-consistent local Hamiltonian then determines the ground-state wavefunction, allowing for accurate diffusion quantum Monte Carlo calculations where the polarization's fixed point is estimated from the average on an iterative sequence. The polarization is sampled through forward-walking. This approach has been validated for the case of the polarizability of an isolated hydrogen atom, and then applied to a periodic system. We then calculate the linear susceptibility and second-order hyper-susceptibility of molecular-hydrogen chains whith different bond-length alternations, and assess the quality of nodal surfaces derived from density-functional theory or from Hartree-Fock. The results found are in excellent agreement with the best estimates obtained from the extrapolation of quantum-chemistry calculations.P. Umari, A.J. Williamson, G. Galli, and N. MarzariPhys. Rev. Lett. 95, 207602 (2005).

Two design of the S4.BEN01 magnet for the CBETA splitter/merger

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

Tsoupas, N.; Berg, S.; Meot, F.

2017-04-10

The splitter/merger section of the CBETA project [1] consists of 4 beam lines as shown in Fig. 1. Two of the functions of the splitter’s/merger’s lines is to match the beam parameters at the exit of the Energy Recovery Linac (ERL) to the beam parameters at the entrance of the Fixed Field Alternating Gradient (FFAG) arc, and also place the reference particles of the beam bunches at the entrance of the FFAG arc on specified trajectories according to their energies. In this technical note we are presenting results from the 2D and 3D electromagnetic analysis of the S4.BEN01 magnet whichmore » is one of the dipole magnets of the 150 MeV line of the splitter/merger. In particular we present results from two designs of the S4.BEN01 magnet, one based on iron dominated current-excited magnet, and the other design based on Halbach-type permanent magnet. An evaluation of the two designs will be given in the section under “conclusion”.« less

Cornell-BNL Electron Energy Recovery Linac FFAG Test Accelerator (CBETA)

NASA Astrophysics Data System (ADS)

Trbojevic, Dejan; Peggs, Steve; Berg, Scott; Brooks, Stephen; Mahler, George; Meot, Francois; Tsoupas, Nicholaos; Witte, Holger; Hoffstaetter, Georg; Bazarov, Ivan; Mayes, Christopher; Patterson, Ritchie; Smolenski, Karl; Li, Yulin; Dobbins, John; BNL Team; Cornell University Team

A novel energy recovery linac (ERL) with Non-Scaling Fixed Field Alternating Gradient (NS-FFAG) racetrack is being constructed as a result of collaboration of the Cornell University with Brookhaven National Laboratory. The existing injector and superconducting linac at Cornell University are being installed together with a single NS-FFAG arcs and straight section at the opposite side of the linac to form an ERL system. The 6 MeV electron beam from injector is transferred into the 36 MeV superconducting linac and accelerated by four successive passes: from 42 to 150 MeV using the same NS-FFAG structure made of permanent magnets. After the maximum energy of 150 MeV is reached, the electron beam is brought back to the linac with opposite Radio Frequency (RF) phase and with 4 passes electron energy is recovered and brought back to the initial energy of 6 MeV. This is going to be the first 4 pass superconducting ERL and the first NS-FFAG permanent magnet structure to bring the electron beam back to the linac.

Can one ADM quantize relativistic bosonicstrings and membranes?

NASA Astrophysics Data System (ADS)

Moncrief, Vincent

2006-04-01

The standard methods for quantizing relativistic strings diverge significantly from the Dirac-Wheeler-DeWitt program for quantization of generally covariant systems and one wonders whether the latter could be successfully implemented as an alternative to the former. As a first step in this direction, we consider the possibility of quantizing strings (and also relativistic membranes) via a partially gauge-fixed ADM (Arnowitt, Deser and Misner) formulation of the reduced field equations for these systems. By exploiting some (Euclidean signature) Hamilton-Jacobi techniques that Mike Ryan and I had developed previously for the quantization of Bianchi IX cosmological models, I show how to construct Diff( S 1)-invariant (or Diff(Σ)-invariant in the case of membranes) ground state wave functionals for the cases of co-dimension one strings and membranes embedded in Minkowski spacetime. I also show that the reduced Hamiltonian density operators for these systems weakly commute when applied to physical (i.e. Diff( S 1) or Diff(Σ)-invariant) states. While many open questions remain, these preliminary results seem to encourage further research along the same lines.

Dynamic self-assembly and directed flow of rotating colloids in microchannels

NASA Astrophysics Data System (ADS)

Götze, Ingo O.; Gompper, Gerhard

2011-09-01

Nonequilibrium structure formation and dynamics in suspensions of superparamagnetic colloids driven by an external rotating magnetic field are studied by particle-based mesoscale hydrodynamics simulations in confined geometry. We address the fundamental question how the rotation of the colloids about their own axes can be converted into a translational motion by breaking the symmetry of the confining geometry. We study a two-dimensional system of colloids with short-range repulsive interactions, which mimics flow in shallow microchannels. In straight channels, we observe a two-way traffic but—for symmetry reasons—no net transport. However, by keeping some colloids fixed near one of the two walls, net transport can be achieved. This approach allows the control and switchability of the flow in complex microchannel networks. A minimal geometry that fulfills the requirement of broken symmetry are ring channels. We determine the translational velocity of the spinning colloids and study its dependence on the channel width for various median radii. We conclude that spinning colloids present a promising alternative for flow generation and control in microfluidic devices.

Regularized variational theories of fracture: A unified approach

NASA Astrophysics Data System (ADS)

Freddi, Francesco; Royer-Carfagni, Gianni

2010-08-01

The fracture pattern in stressed bodies is defined through the minimization of a two-field pseudo-spatial-dependent functional, with a structure similar to that proposed by Bourdin-Francfort-Marigo (2000) as a regularized approximation of a parent free-discontinuity problem, but now considered as an autonomous model per se. Here, this formulation is altered by combining it with structured deformation theory, to model that when the material microstructure is loosened and damaged, peculiar inelastic (structured) deformations may occur in the representative volume element at the price of surface energy consumption. This approach unifies various theories of failure because, by simply varying the form of the class for admissible structured deformations, different-in-type responses can be captured, incorporating the idea of cleavage, deviatoric, combined cleavage-deviatoric and masonry-like fractures. Remarkably, this latter formulation rigorously avoid material overlapping in the cracked zones. The model is numerically implemented using a standard finite-element discretization and adopts an alternate minimization algorithm, adding an inequality constraint to impose crack irreversibility ( fixed crack model). Numerical experiments for some paradigmatic examples are presented and compared for various possible versions of the model.

Chitosan in Molecularly-Imprinted Polymers: Current and Future Prospects.

PubMed

Xu, Long; Huang, Yun-An; Zhu, Qiu-Jin; Ye, Chun

2015-08-07

Chitosan is widely used in molecular imprinting technology (MIT) as a functional monomer or supporting matrix because of its low cost and high contents of amino and hydroxyl functional groups. The various excellent properties of chitosan, which include nontoxicity, biodegradability, biocompatibility, and attractive physical and mechanical performances, make chitosan a promising alternative to conventional functional monomers. Recently, chitosan molecularly-imprinted polymers have gained considerable attention and showed significant potential in many fields, such as curbing environmental pollution, medicine, protein separation and identification, and chiral-compound separation. These extensive applications are due to the polymers' desired selectivity, physical robustness, and thermal stability, as well as their low cost and easy preparation. Cross-linkers, which fix the functional groups of chitosan around imprinted molecules, play an important role in chitosan molecularly-imprinted polymers. This review summarizes the important cross-linkers of chitosan molecularly-imprinted polymers and illustrates the cross-linking mechanism of chitosan and cross-linkers based on the two glucosamine units. Finally, some significant attempts to further develop the application of chitosan in MIT are proposed.

Methods of Using a Magnetic Field Response Sensor Within Closed, Electrically Conductive Containers

NASA Technical Reports Server (NTRS)

Woodward, Stanley E.; Taylor, Bryant D.

2010-01-01

Magnetic field response sensors are a class of sensors that are powered via oscillating magnetic fields, and when electrically active, respond with their own magnetic fields with attributes dependent upon the magnitude of the physical quantity being measured. A magnetic field response recorder powers and interrogates the magnetic sensors [see Magnetic-Field-Response Measurement- Acquisition System, NASA Tech Briefs Vol. 30, No, 6 (June 2006, page 28)]. Electrically conductive containers have low transmissivity for radio frequency (RF) energy and thus present problems for magnetic field response sensors. It is necessary in some applications to have a magnetic field response sensor s capacitor placed in these containers. Proximity to conductive surfaces alters the inductance and capacitance of the sensors. As the sensor gets closer to a conductive surface, the electric field and magnetic field energy of the sensor is reduced due to eddy currents being induced in the conductive surface. Therefore, the capacitors and inductors cannot be affixed to a conductive surface or embedded in a conductive material. It is necessary to have a fixed separation away from the conductive material. The minimum distance for separation is determined by the desired sensor response signal to noise ratio. Although the inductance is less than what it would be if it were not in proximity to the conductive surface, the inductance is fixed. As long as the inductance is fixed, all variations of the magnetic field response are due to capacitance changes. Numerous variations of inductor mounting can be utilized, such as providing a housing that provides separation from the conductive material as well as protection from impact damage. The sensor can be on the same flexible substrate with a narrow throat portion of the sensor between the inductor and the capacitor, Figure 1. The throat is of sufficient length to allow the capacitor to be appropriately placed within the container and the inductor placed outside the container. The throat is fed through the orifice in the container wall (e.g., fuel tank opening) and connects to the inductor and capacitor via electrical leads to form a closed circuit, Figure 2. Another embodiment is to have the inductor and capacitor fabricated as separate units. In this embodiment, the inductor is mounted external to the container, and the capacitor is mounted internal to the container, Figure 1. Electrical leads are fed through the orifice to connect the inductor and capacitor, Figure 2. When a container holding multiple sensors is made of a conductive material, an antenna can be placed internal to the container. An internal antenna allows all components of the sensors to reside inside the container. The antenna must be separated from the container wall s conductive surface. Additionally, the inductors must be maintained in a fixed position relative to and separated from the container

Microsystem enabled photovoltaic modules and systems

DOEpatents

Nielson, Gregory N; Sweatt, William C; Okandan, Murat

2015-05-12

A microsystem enabled photovoltaic (MEPV) module including: an absorber layer; a fixed optic layer coupled to the absorber layer; a translatable optic layer; a translation stage coupled between the fixed and translatable optic layers; and a motion processor electrically coupled to the translation stage to controls motion of the translatable optic layer relative to the fixed optic layer. The absorber layer includes an array of photovoltaic (PV) elements. The fixed optic layer includes an array of quasi-collimating (QC) micro-optical elements designed and arranged to couple incident radiation from an intermediate image formed by the translatable optic layer into one of the PV elements such that it is quasi-collimated. The translatable optic layer includes an array of focusing micro-optical elements corresponding to the QC micro-optical element array. Each focusing micro-optical element is designed to produce a quasi-telecentric intermediate image from substantially collimated radiation incident within a predetermined field of view.

Mental Depreciation and Marginal Decision Making

PubMed

Heath; Fennema

1996-11-01

We propose that individuals practice "mental depreciation," that is, they implicitly spread the fixed costs of their expenses over time or use. Two studies explore how people spread fixed costs on durable goods. A third study shows that depreciation can lead to two distinct errors in marginal decisions: First, people sometimes invest too much effort to get their money's worth from an expense (e.g., they may use a product a lot to spread the fixed expense across more uses). Second, people sometimes invest too little effort to get their money's worth: When people add a portion of the fixed cost to the current costs, their perceived marginal (i.e., incremental) costs exceed their true marginal costs. In response, they may stop investing because their perceived costs surpass the marginal benefits they are receiving. The latter effect is supported by two field studies that explore real board plan decisions by university students.

[Proximate analysis of straw by near infrared spectroscopy (NIRS)].

PubMed

Huang, Cai-jin; Han, Lu-jia; Liu, Xian; Yang, Zeng-ling

2009-04-01

Proximate analysis is one of the routine analysis procedures in utilization of straw for biomass energy use. The present paper studied the applicability of rapid proximate analysis of straw by near infrared spectroscopy (NIRS) technology, in which the authors constructed the first NIRS models to predict volatile matter and fixed carbon contents of straw. NIRS models were developed using Foss 6500 spectrometer with spectra in the range of 1,108-2,492 nm to predict the contents of moisture, ash, volatile matter and fixed carbon in the directly cut straw samples; to predict ash, volatile matter and fixed carbon in the dried milled straw samples. For the models based on directly cut straw samples, the determination coefficient of independent validation (R2v) and standard error of prediction (SEP) were 0.92% and 0.76% for moisture, 0.94% and 0.84% for ash, 0.88% and 0.82% for volatile matter, and 0.75% and 0.65% for fixed carbon, respectively. For the models based on dried milled straw samples, the determination coefficient of independent validation (R2v) and standard error of prediction (SEP) were 0.98% and 0.54% for ash, 0.95% and 0.57% for volatile matter, and 0.78% and 0.61% for fixed carbon, respectively. It was concluded that NIRS models can predict accurately as an alternative analysis method, therefore rapid and simultaneous analysis of multicomponents can be achieved by NIRS technology, decreasing the cost of proximate analysis for straw.

Assessing the feasibility of yttria-stabilized zirconia in novel designs as mandibular anterior fixed lingual retention following orthodontic treatment

NASA Astrophysics Data System (ADS)

Stout, Matthew

The purpose of this study is to explore the feasibility of yttria-stabilized zirconia (Y-TZP) in fixed lingual retention as an alternative to stainless steel. Exploratory Y-TZP specimens were milled to establish design parameters. Next, specimens were milled according to ASTM standard C1161-13 and subjected to four-point flexural test to determine materials properties. Finite Element (FE) Analysis was employed to evaluate nine novel cross-sectional designs and compared to stainless steel wire. Each design was analyzed under the loading conditions to determine von Mises and bond stress. The most promising design was fabricated to assess accuracy and precision of current CAD/CAM milling technology. The superior design had a 1.0 x 0.5 mm semi-elliptical cross section and was shown to be fabricated reliably. Overall, the milling indicated a maximum percent standard deviation of 9.3 and maximum percent error of 13.5 with a cost of $30 per specimen. Y-TZP can be reliably milled to dimensions comparable to currently available metallic retainer wires. Further research is necessary to determine the success of bonding protocol and clinical longevity of Y-TZP fixed retainers. Advanced technology is necessary to connect the intraoral scan to an aesthetic and patient-specific Y-TZP fixed retainer.

Thermodynamic Temperature of High-Temperature Fixed Points Traceable to Blackbody Radiation and Synchrotron Radiation

NASA Astrophysics Data System (ADS)

Wähmer, M.; Anhalt, K.; Hollandt, J.; Klein, R.; Taubert, R. D.; Thornagel, R.; Ulm, G.; Gavrilov, V.; Grigoryeva, I.; Khlevnoy, B.; Sapritsky, V.

2017-10-01

Absolute spectral radiometry is currently the only established primary thermometric method for the temperature range above 1300 K. Up to now, the ongoing improvements of high-temperature fixed points and their formal implementation into an improved temperature scale with the mise en pratique for the definition of the kelvin, rely solely on single-wavelength absolute radiometry traceable to the cryogenic radiometer. Two alternative primary thermometric methods, yielding comparable or possibly even smaller uncertainties, have been proposed in the literature. They use ratios of irradiances to determine the thermodynamic temperature traceable to blackbody radiation and synchrotron radiation. At PTB, a project has been established in cooperation with VNIIOFI to use, for the first time, all three methods simultaneously for the determination of the phase transition temperatures of high-temperature fixed points. For this, a dedicated four-wavelengths ratio filter radiometer was developed. With all three thermometric methods performed independently and in parallel, we aim to compare the potential and practical limitations of all three methods, disclose possibly undetected systematic effects of each method and thereby confirm or improve the previous measurements traceable to the cryogenic radiometer. This will give further and independent confidence in the thermodynamic temperature determination of the high-temperature fixed point's phase transitions.

Ontogenetic loss of phenotypic plasticity of age at metamorphosis in tadpoles

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

Hensley, F.R.

1993-12-01

Amphibian larvae exhibit phenotypic plasticity in size at metamorphosis and duration of the larval period. I used Pseudacris crucifer tadpoles to test two models for predicting tadpole age and size at metamorphosis under changing environmental conditions. The Wilbur-Collins model states that metamorphosis is initiated as a function of a tadpole's size and relative growth rate, and predicts that changes in growth rate throughout the larval period affect age and size at metamorphosis. An alternative model, the fixed-rate model, states that age at metamorphosis is fixed early in larval life, and subsequent changes in growth rate will have no effect onmore » the length of the larval period. My results confirm that food supplies affect both age and size at metamorphosis, but developmental rates became fixed at approximately Gosner (1960) stages 35-37. Neither model completely predicted these results. I suggest that the generally accepted Wilbur-Collins model is improved by incorporating a point of fixed developmental timing. Growth trajectories predicted from this modified model fit the results of this study better than trajectories based on either of the original models. The results of this study suggests a constraint that limits the simultaneous optimization of age and size at metamorphosis. 32 refs., 5 figs., 1 tab.« less

Comparison of dorzolamide/timolol vs brinzolamide/brimonidine fixed combination therapy in the management of primary open-angle glaucoma.

PubMed

Kozobolis, Vassileios; Panos, Georgios D; Konstantinidis, Aristeidis; Labiris, Georgios

2017-03-10

To compare the efficiency of brinzolamide/brimonidine fixed combination vs the dorzolamide/timolol fixed combination. Forty-four eyes of 44 patients were divided in 2 groups treated either with dorzolamide/timolol twice a day (group A) or with brinzolamide/brimonidine twice a day (group B). Complete ophthalmic examination including Goldmann applanation tonometry was performed before treatment administration and 1, 4, 8, and 12 weeks afterwards. The intraocular pressure (IOP) was measured twice a day (morning at 9 AM and afternoon at 4 PM). At the end of the follow-up period (12 weeks), mean morning IOP reduction was 7.0 ± 2.8 mm Hg in group A and 8.4 ± 1.9 mm Hg in group B. A significant difference was found (p = 0.0343). In contrast, mean afternoon IOP reduction was 8.6 ± 2.7 mm Hg in group A and 7.9 ± 1.6 mm Hg in group B and no significant difference was found (p = 0.3413). No significant adverse effects were observed in either group. Brinzolamide/brimonidine seems to be an effective and safe alternative β-blocker free fixed combination, especially for patients with comorbidities, having its own antihypertensive profile.

Experimental Microfracture Permeability Development in Crystalline Rocks Under Different Tectonic Stress Regimes

NASA Astrophysics Data System (ADS)

Faulkner, D. R.; Armitage, P. J.

2011-12-01

Geothermal fields rely on permeable fracture networks that can act for significant periods of time. In crystalline rocks, permeability may be stimulated by injections of fluid pressure at depth. We show how high-pressure laboratory experiments can be used to quantify the effects of different stress states on the permeability of two rocks; Darley Dale sandstone (~10-16 m2 permeability) and Westerly granite (~10-20 m2 permeability). It is well known that microfractures start to grow at stresses around one half of the failure stress. Failure in the experiments was reproduced in several ways: (1) by fixing σ3 and increasing σ1 - equivalent to a compressive or strike-slip tectonic regime (2) by fixing σ1 and decreasing σ3 - equivalent to an extensional tectonic regime (3) by increasing the pore fluid pressure at a fixed differential stress to simulate high pore fluid pressure failure, and (4) by fixing the mean stress while increasing σ1 and decreasing σ3 in sympathy. Permeability was monitored during all of these tests. From these tests we are able to quantify the relative contributions of mean stress, differential stress and pore fluid pressure on the permeability in the pre-failure region. This provides key data on the development of microfracture permeability that might be produced during the stimulation of geothermal fields during injection within different tectonic environments.

A novel micromixer based on the alternating current-flow field effect transistor.

PubMed

Wu, Yupan; Ren, Yukun; Tao, Ye; Hou, Likai; Hu, Qingming; Jiang, Hongyuan

2016-12-20

Induced-charge electroosmosis (ICEO) phenomena have been attracting considerable attention as a means for pumping and mixing in microfluidic systems with the advantage of simple structures and low-energy consumption. We propose the first effort to exploit a fixed-potential ICEO flow around a floating electrode for microfluidic mixing. In analogy with the field effect transistor (FET) in microelectronics, the floating electrode act as a "gate" electrode for generating asymmetric ICEO flow and thus the device is called an AC-flow FET (AC-FFET). We take advantage of a tandem electrode configuration containing two biased center metal strips arranged in sequence at the bottom of the channel to generate asymmetric vortexes. The current device is manufactured on low-cost glass substrates via an easy and reliable process. Mixing experiments were conducted in the proposed device and the comparison between simulation and experimental results was also carried out, which indicates that the micromixer permits an efficient mixing effect. The mixing performance can be further enhanced by the application of a suitable phase difference between the driving electrode and the gate electrode or a square wave signal. Finally, we performed a critical analysis of the proposed micromixer in comparison with different mixer designs using a comparative mixing index (CMI). The novel methods put forward here offer a simple solution to mixing issues in microfluidic systems.

Free adrenaline and noradrenaline excretion related to occupational stress.

PubMed Central

Timio, M; Gentili, S; Pede, S

1979-01-01

Urinary levels of free adrenaline and noradrenaline were measured in two groups of healthy male industrial workers exposed to alternate four-day periods of working conditions with and without time stress, to test the hypothesis that the sympathetic nervous system is overactivated by occupational stress. Thirty confectionary workers alternated piece-work (payment by results) and work with a fixed daily wage while 30 metal workers alternated work on an assembly line with work off it. Under time stress urinary free adrenaline was 450 per cent and noradrenaline 230 per cent of the levels for similar work without time stress but involving equal oxygen consumption. These differences were statistically highly significant and they persisted on retesting after six months of alternating work regimens. They support the concept that occupational stress in industrial workers influences the adrenosympathetic system and they indicate a possible method for assessing the effects of high levels of sympathetic activity on the aetiology of ischaemic heart disease. PMID:508478

Electric field measuring and display system. [for cloud formations

NASA Technical Reports Server (NTRS)

Wojtasinski, R. J.; Lovall, D. D. (Inventor)

1974-01-01

An apparatus is described for monitoring the electric fields of cloud formations within a particular area. It utilizes capacitor plates that are alternately shielded from the clouds for generating an alternating signal corresponding to the intensity of the electric field of the clouds. A synchronizing signal is produced for controlling sampling of the alternating signal. Such samplings are fed through a filter and converted by an analogue to digital converter into digital form and subsequently fed to a transmitter for transmission to the control station for recording.

Evaluating Parametrization Protocols for Hydration Free Energy Calculations with the AMOEBA Polarizable Force Field.

PubMed

Bradshaw, Richard T; Essex, Jonathan W

2016-08-09

Hydration free energy (HFE) calculations are often used to assess the performance of biomolecular force fields and the quality of assigned parameters. The AMOEBA polarizable force field moves beyond traditional pairwise additive models of electrostatics and may be expected to improve upon predictions of thermodynamic quantities such as HFEs over and above fixed-point-charge models. The recent SAMPL4 challenge evaluated the AMOEBA polarizable force field in this regard but showed substantially worse results than those using the fixed-point-charge GAFF model. Starting with a set of automatically generated AMOEBA parameters for the SAMPL4 data set, we evaluate the cumulative effects of a series of incremental improvements in parametrization protocol, including both solute and solvent model changes. Ultimately, the optimized AMOEBA parameters give a set of results that are not statistically significantly different from those of GAFF in terms of signed and unsigned error metrics. This allows us to propose a number of guidelines for new molecule parameter derivation with AMOEBA, which we expect to have benefits for a range of biomolecular simulation applications such as protein-ligand binding studies.

BFV-BRST quantization of two-dimensional supergravity

NASA Astrophysics Data System (ADS)

Fujiwara, T.; Igarashi, Y.; Kuriki, R.; Tabei, T.

1996-01-01

Two-dimensional supergravity theory is quantized as an anomalous gauge theory. In the Batalin-Fradkin (BF) formalism, the anomaly-canceling super-Liouville fields are introduced to identify the original second-class constrained system with a gauge-fixed version of a first-class system. The BFV-BRST quantization applies to formulate the theory in the most general class of gauges. A local effective action constructed in the configuration space contains two super-Liouville actions; one is a noncovariant but local functional written only in terms of two-dimensional supergravity fields, and the other contains the super-Liouville fields canceling the super-Weyl anomaly. Auxiliary fields for the Liouville and the gravity supermultiplets are introduced to make the BRST algebra close off-shell. Inclusion of them turns out to be essentially important especially in the super-light-cone gauge fixing, where the supercurvature equations (∂3-g++=∂2-χ++=0) are obtained as a result of BRST invariance of the theory. Our approach reveals the origin of the OSp(1,2) current algebra symmetry in a transparent manner.

Super-resolution chemical imaging with dynamic placement of plasmonic hotspots

NASA Astrophysics Data System (ADS)

Olson, Aeli P.; Ertsgaard, Christopher T.; McKoskey, Rachel M.; Rich, Isabel S.; Lindquist, Nathan C.

2015-08-01

We demonstrate dynamic placement of plasmonic "hotspots" for super-resolution chemical imaging via Surface Enhanced Raman Spectroscopy (SERS). A silver nanohole array surface was coated with biological samples and illuminated with a laser. Due to the large plasmonic field enhancements, blinking behavior of the SERS hotspots was observed and processed using a Stochastic Optical Reconstruction Microscopy (STORM) algorithm enabling localization to within 10 nm. However, illumination of the sample with a single static laser beam (i.e., a slightly defocused Gaussian beam) only produced SERS hotspots in fixed locations on the surface, leaving noticeable gaps in any final image. But, by using a spatial light modulator (SLM), the illumination profile of the beam could be altered, shifting any hotspots across the nanohole array surface in sub-wavelength steps. Therefore, by properly structuring an illuminating light field with the SLM, we show the possibility of positioning plasmonic hotspots over a metallic nanohole surface on-the-fly. Using this and our SERS-STORM imaging technique, we show potential for high-resolution chemical imaging without the noticeable gaps that were present with static laser illumination. Interestingly, even illuminating the surface with randomly shifting SLM phase profiles was sufficient to completely fill in a wide field of view for super-resolution SERS imaging of a single strand of 100-nm thick collagen protein fibrils. Images were then compared to those obtained with a scanning electron microscope (SEM). Additionally, we explored alternative methods of phase shifting other than holographic illumination through the SLM to create localization of hotspots necessary for SERS-STORM imaging.

Estimation of genetic connectedness diagnostics based on prediction errors without the prediction error variance-covariance matrix.

PubMed

Holmes, John B; Dodds, Ken G; Lee, Michael A

2017-03-02

An important issue in genetic evaluation is the comparability of random effects (breeding values), particularly between pairs of animals in different contemporary groups. This is usually referred to as genetic connectedness. While various measures of connectedness have been proposed in the literature, there is general agreement that the most appropriate measure is some function of the prediction error variance-covariance matrix. However, obtaining the prediction error variance-covariance matrix is computationally demanding for large-scale genetic evaluations. Many alternative statistics have been proposed that avoid the computational cost of obtaining the prediction error variance-covariance matrix, such as counts of genetic links between contemporary groups, gene flow matrices, and functions of the variance-covariance matrix of estimated contemporary group fixed effects. In this paper, we show that a correction to the variance-covariance matrix of estimated contemporary group fixed effects will produce the exact prediction error variance-covariance matrix averaged by contemporary group for univariate models in the presence of single or multiple fixed effects and one random effect. We demonstrate the correction for a series of models and show that approximations to the prediction error matrix based solely on the variance-covariance matrix of estimated contemporary group fixed effects are inappropriate in certain circumstances. Our method allows for the calculation of a connectedness measure based on the prediction error variance-covariance matrix by calculating only the variance-covariance matrix of estimated fixed effects. Since the number of fixed effects in genetic evaluation is usually orders of magnitudes smaller than the number of random effect levels, the computational requirements for our method should be reduced.

Alternative Reinforcer Response Cost Impacts Cocaine Choice in Humans

PubMed Central

Stoops, William W.; Lile, Joshua A.; Glaser, Paul E.A.; Hays, Lon R.; Rush, Craig R.

2011-01-01

Cocaine use disorders are an unrelenting public health concern. Behavioral treatments reduce cocaine use by providing non-drug alternative reinforcers. The purpose of this human laboratory experiment was to determine how response cost for non-drug alternative reinforcers influenced cocaine choice. Seven cocaine-using, non-treatment-seeking subjects completed a crossover, double-blind protocol in which they first sampled doses of intranasal cocaine (5, 10, 20 or 30 mg) and completed a battery of subject-rated and physiological measures. Subjects then made eight discrete choices between the sampled dose and an alternative reinforce (US$0.25). The response cost to earn a cocaine dose was always a fixed ratio (FR) of 100 responses. The response cost for the alternative reinforcer varied across sessions (FR1, FR10, FR100, FR1000). Dose-related increases were observed for cocaine choice. Subjects made fewer drug choices when the FR requirements for the alternative reinforcers were lower than that for drug relative to when the FR requirements were equal to or higher than that for drug. Intranasal cocaine also produced prototypical stimulant-like subject-rated and physiological effects (e.g., increased ratings of Like Drug; elevated blood pressure). These data demonstrate that making alternative reinforcers easier to earn reduces cocaine self-administration, which has implications for treatment efforts. PMID:22015480

Capacitance-voltage analysis of electrical properties for WSe2 field effect transistors with high-k encapsulation layer

NASA Astrophysics Data System (ADS)

Ko, Seung-Pil; Shin, Jong Mok; Jang, Ho Kyun; You, Min Youl; Jin, Jun-Eon; Choi, Miri; Cho, Jiung; Kim, Gyu-Tae

2018-02-01

Doping effects in devices based on two-dimensional (2D) materials have been widely studied. However, detailed analysis and the mechanism of the doping effect caused by encapsulation layers has not been sufficiently explored. In this work, we present experimental studies on the n-doping effect in WSe2 field effect transistors (FETs) with a high-k encapsulation layer (Al2O3) grown by atomic layer deposition. In addition, we demonstrate the mechanism and origin of the doping effect. After encapsulation of the Al2O3 layer, the threshold voltage of the WSe2 FET negatively shifted with the increase of the on-current. The capacitance-voltage measurements of the metal insulator semiconductor (MIS) structure proved the presence of the positive fixed charges within the Al2O3 layer. The flat-band voltage of the MIS structure of Au/Al2O3/SiO2/Si was shifted toward the negative direction on account of the positive fixed charges in the Al2O3 layer. Our results clearly revealed that the fixed charges in the Al2O3 encapsulation layer modulated the Fermi energy level via the field effect. Moreover, these results possibly provide fundamental ideas and guidelines to design 2D materials FETs with high-performance and reliability.

Microbial Ecology of Thermophilic Anaerobic Digestion. Final Report

DOE R&D Accomplishments Database

Zinder, Stephen H.

2000-04-15

This grant supported research on methanogenic archaea. The two major areas that were supported were conversion of acetic acid to methane and nitrogen fixation by Methanosarcina. Among the achievements of this research were the isolation of novel methanogenic cultures, elucidation of the pathways from acetate to methane, description of a specific DNA-binding complex in nitrogen fixing methanogens, and demonstration of an alternative nitrogenase in Methanosarcina.

Resistance to Viral Challenge in the Days Immediately Following Vaccination.

DTIC Science & Technology

Powassan or yellow fever, by the intraperitoneal route into guinea pigs failed to induce visible signs of illness; however, with Japanese encephalitis... Powassan , and Banzi viruses, high titered complement-fixing antibodies developed. Since no disease and death could be used as a criterion of successful...infection of guinea pigs inoculated with Japanese encephalitis virus, or of hamsters inoculated with Powassan , an alternative method of determining

Selection of Common Items as an Unrecognized Source of Variability in Test Equating: A Bootstrap Approximation Assuming Random Sampling of Common Items

ERIC Educational Resources Information Center

Michaelides, Michalis P.; Haertel, Edward H.

2014-01-01

The standard error of equating quantifies the variability in the estimation of an equating function. Because common items for deriving equated scores are treated as fixed, the only source of variability typically considered arises from the estimation of common-item parameters from responses of samples of examinees. Use of alternative, equally…

Successive Over-Relaxation Technique for High-Performance Blind Image Deconvolution

DTIC Science & Technology

2015-06-08

deconvolution, space surveillance, Gauss - Seidel iteration 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT SAR 18, NUMBER OF PAGES 5...sensible approximate solutions to the ill-posed nonlinear inverse problem. These solutions are addresses as fixed points of the iteration which consists in...alternating approximations (AA) for the object and for the PSF performed with a prescribed number of inner iterative descents from trivial (zero

Innovative Solidification Techniques for Hazardous Wastes at Army Installations.

DTIC Science & Technology

1985-11-01

Fixed Hazardous Industrial Wastes and Flue Gas Desulfurization Sludges," Interim Report, EPA-600/2-76-182, US Environmental Protection Agency... flue gas . Flyash from coal-fired power plants is an almost entirely inorganic product having a glassy nature. Consequently, flyash by itself has little...effective- ness of alternative control strategies for reducing environmental impacts. 4. % 46 -"- °° ~~~~~...-.-..o

Rapid Acquisition of Preference in Concurrent Chains when Alternatives Differ on Multiple Dimensions of Reinforcement

ERIC Educational Resources Information Center

Kyonka, Elizabeth G. E.; Grace, Randolph C.

2008-01-01

Pigeons responded in a concurrent-chains procedure in which terminal-link reinforcer variables were changed unpredictably across sessions. In Experiment 1, the terminal-link schedules were fixed-interval (FI) 8 s and FI 16 s, and the reinforcer magnitudes were 2 s and 4 s. In Experiment 2 the probability of reinforcement (100% or 50%) was varied…

Estimating equations estimates of trends

USGS Publications Warehouse

Link, W.A.; Sauer, J.R.

1994-01-01

The North American Breeding Bird Survey monitors changes in bird populations through time using annual counts at fixed survey sites. The usual method of estimating trends has been to use the logarithm of the counts in a regression analysis. It is contended that this procedure is reasonably satisfactory for more abundant species, but produces biased estimates for less abundant species. An alternative estimation procedure based on estimating equations is presented.

Paleomagnetic and rock magnetic results from Koko Seamount (ODP Leg 197, Site 1206): Implications for hotspot motion

NASA Astrophysics Data System (ADS)

Olton, G.; Cottrell, R. D.; Tarduno, J. A.; Carvallo, C.; Torii, M.; Doubrovine, P. V.

2002-12-01

ODP Leg 197 sought to test whether the Hawaiian hotspot was fixed in the mantle during Late Cretaceous to Early Tertiary times. The principal goal was the recovery of basalt sequences from several of the Emperor seamounts and the main tool to be applied was paleomagnetism. Koko Seamount, near the bend in the Hawaiian-Emperor Seamounts, was the southernmost site drilled during Leg 197. Fifteen basalt units separated by thick volcaniclastic units were recovered in 278 m of penetration. Based on nannofossil stratigraphy of the sediments above basalt, the top of the volcanic section is 43.5-49.7 m.y.-old. Shipboard geochemical analyses (Initial Reports, Leg 197) indicate the lavas include tholeiites, suggesting that the age of the sequence recovered is similar to that of the major phase of shield building. Detailed, stepwise alternating field demagnetization experiments, and subsequent principal component analysis (all conducted aboard the JOIDES Resolution) yielded 14 inclination groups suggesting a mean paleolatitude of 21.7o N, slightly steeper than that the present-day latitude of Hawaii. Shore-based hysteresis measurements of basalt samples indicate single to pseudo-single domain behavior (mean Hc = 170 Oe, Hcr = 309 Oe, Mr/Ms = 0.274), whereas unblocking temperatures range from 200-300 oC and 550-600 oC. These data suggest the presence of high titanium titanomagnetite and magnetite. Shore-based thermal demagnetization inclinations are similar to the shipboard alternating field demagnetization data. The paleomagnetic data from Koko Seamount, together with results from Detroit, Suiko and Nintoku Seamounts form a southward decreasing series of paleolatitudes that appear to track motion of the Hawaiian ``hotspot" in the mantle. Rates of motion based on paleolatitudes of the Emperor Seamounts range from 30-50 mm/yr, similar to that observed for some continental plates.

Application of photogrammetry to transforming PIV-acquired velocity fields to a moving-body coordinate system

NASA Astrophysics Data System (ADS)

Nikoueeyan, Pourya; Naughton, Jonathan

2016-11-01

Particle Image Velocimetry is a common choice for qualitative and quantitative characterization of unsteady flows associated with moving bodies (e.g. pitching and plunging airfoils). Characterizing the separated flow behavior is of great importance in understanding the flow physics and developing predictive reduced-order models. In most studies, the model under investigation moves within a fixed camera field-of-view, and vector fields are calculated based on this fixed coordinate system. To better characterize the genesis and evolution of vortical structures in these unsteady flows, the velocity fields need to be transformed into the moving-body frame of reference. Data converted to this coordinate system allow for a more detailed analysis of the flow field using advanced statistical tools. In this work, a pitching NACA0015 airfoil has been used to demonstrate the capability of photogrammetry for such an analysis. Photogrammetry has been used first to locate the airfoil within the image and then to determine an appropriate mask for processing the PIV data. The photogrammetry results are then further used to determine the rotation matrix that transforms the velocity fields to airfoil coordinates. Examples of the important capabilities such a process enables are discussed. P. Nikoueeyan is supported by a fellowship from the University of Wyoming's Engineering Initiative.

Calculations of the Electric Fields in Liquid Solutions

PubMed Central

Fried, Stephen D.; Wang, Lee-Ping; Boxer, Steven G.; Ren, Pengyu; Pande, Vijay S.

2014-01-01

The electric field created by a condensed phase environment is a powerful and convenient descriptor for intermolecular interactions. Not only does it provide a unifying language to compare many different types of interactions, but it also possesses clear connections to experimental observables, such as vibrational Stark effects. We calculate here the electric fields experienced by a vibrational chromophore (the carbonyl group of acetophenone) in an array of solvents of diverse polarities using molecular dynamics simulations with the AMOEBA polarizable force field. The mean and variance of the calculated electric fields correlate well with solvent-induced frequency shifts and band broadening, suggesting Stark effects as the underlying mechanism of these key solution phase spectral effects. Compared to fixed-charge and continuum models, AMOEBA was the only model examined that could describe non-polar, polar, and hydrogen bonding environments in a consistent fashion. Nevertheless, we found that fixed-charge force fields and continuum models were able to replicate some results of the polarizable simulations accurately, allowing us to clearly identify which properties and situations require explicit polarization and/or atomistic representations to be modeled properly, and for which properties and situations simpler models are sufficient. We also discuss the ramifications of these results for modeling electrostatics in complex environments, such as proteins. PMID:24304155

Inhibition of brain tumor cell proliferation by alternating electric fields

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

Jeong, Hyesun; Oh, Seung-ick; Hong, Sunghoi, E-mail: shong21@korea.ac.kr, E-mail: radioyoon@korea.ac.kr

2014-11-17

This study was designed to investigate the mechanism by which electric fields affect cell function, and to determine the optimal conditions for electric field inhibition of cancer cell proliferation. Low-intensity (<2 V/cm) and intermediate-frequency (100–300 kHz) alternating electric fields were applied to glioblastoma cell lines. These electric fields inhibited cell proliferation by inducing cell cycle arrest and abnormal mitosis due to the malformation of microtubules. These effects were significantly dependent on the intensity and frequency of applied electric fields.

A fully Sinc-Galerkin method for Euler-Bernoulli beam models

NASA Technical Reports Server (NTRS)

Smith, R. C.; Bowers, K. L.; Lund, J.

1990-01-01

A fully Sinc-Galerkin method in both space and time is presented for fourth-order time-dependent partial differential equations with fixed and cantilever boundary conditions. The Sinc discretizations for the second-order temporal problem and the fourth-order spatial problems are presented. Alternate formulations for variable parameter fourth-order problems are given which prove to be especially useful when applying the forward techniques to parameter recovery problems. The discrete system which corresponds to the time-dependent partial differential equations of interest are then formulated. Computational issues are discussed and a robust and efficient algorithm for solving the resulting matrix system is outlined. Numerical results which highlight the method are given for problems with both analytic and singular solutions as well as fixed and cantilever boundary conditions.

Computational alternatives to obtain time optimal jet engine control. M.S. Thesis

NASA Technical Reports Server (NTRS)

Basso, R. J.; Leake, R. J.

1976-01-01

Two computational methods to determine an open loop time optimal control sequence for a simple single spool turbojet engine are described by a set of nonlinear differential equations. Both methods are modifications of widely accepted algorithms which can solve fixed time unconstrained optimal control problems with a free right end. Constrained problems to be considered have fixed right ends and free time. Dynamic programming is defined on a standard problem and it yields a successive approximation solution to the time optimal problem of interest. A feedback control law is obtained and it is then used to determine the corresponding open loop control sequence. The Fletcher-Reeves conjugate gradient method has been selected for adaptation to solve a nonlinear optimal control problem with state variable and control constraints.

The 18 and 30 GHz fixed service communication satellite system study: Executive summary

NASA Technical Reports Server (NTRS)

Bronstein, L. M.

1979-01-01

The use of the 18 and 30 GHz bands for fixed service satellite communications is examined. Primary objectives were to determine if satellite communication systems using this allocation (27.5 to 30.0 GHz uplink; 17.7 to 20.2 GHz downlink) can be cost competitive with alternate means of communication, and to determine what technological developments would be required to make these systems competitive. To meet these objectives, the cost and performance to be expected of 18 and 30 GHz hardware in the 1985 to 1990 era was assessed, selected trunking and direct to user concepts were optimized, and the cost of these systems was estimated. Finally, the technology developments required to make the most promising of the concepts competitive were identified.

Flow cytometric method for measuring chromatin fragmentation in fixed sperm from yellow perch (Perca flavescens).

PubMed

Jenkins, J A; Draugelis-Dale, R O; Pinkney, A E; Iwanowicz, L R; Blazer, V S

2015-03-15

Declining harvests of yellow perch, Perca flavescens, in urbanized watersheds of Chesapeake Bay have prompted investigations of their reproductive fitness. The purpose of this study was to establish a flow cytometric technique for DNA analysis of fixed samples sent from the field to provide reliable gamete quality measurements. Similar to the sperm chromatin structure assay, measures were made on the susceptibility of nuclear DNA to acid-induced denaturation, but used fixed rather than live or thawed cells. Nuclei were best exposed to the acid treatment for 1 minute at 37 °C followed by the addition of cold (4 °C) propidium iodide staining solution before flow cytometry. The rationale for protocol development is presented graphically through cytograms. Field results collected in 2008 and 2009 revealed DNA fragmentation up to 14.5%. In 2008, DNA fragmentation from the more urbanized watersheds was significantly greater than from reference sites (P = 0.026) and in 2009, higher percentages of haploid testicular cells were noted from the less urbanized watersheds (P = 0.032) indicating better reproductive condition at sites with less urbanization. For both years, total and progressive live sperm motilities by computer-assisted sperm motion analysis ranged from 19.1% to 76.5%, being significantly higher at the less urbanized sites (P < 0.05). This flow cytometric method takes advantage of the propensity of fragmented DNA to be denatured under standard conditions, or 1 minute at 37 °C with 10% buffered formalin-fixed cells. The study of fixed sperm makes possible the restrospective investigation of germplasm fragmentation, spermatogenic ploidy patterns, and chromatin compaction levels from samples translocated over distance and time. The protocol provides an approach that can be modified for other species across taxa. Published by Elsevier Inc.

Second rank direction cosine spherical tensor operators and the nuclear electric quadrupole hyperfine structure Hamiltonian of rotating molecules

NASA Astrophysics Data System (ADS)

di Lauro, C.

2018-03-01

Transformations of vector or tensor properties from a space-fixed to a molecule-fixed axis system are often required in the study of rotating molecules. Spherical components λμ,ν of a first rank irreducible tensor can be obtained from the direction cosines between the two axis systems, and a second rank tensor with spherical components λμ,ν(2) can be built from the direct product λ × λ. It is shown that the treatment of the interaction between molecular rotation and the electric quadrupole of a nucleus is greatly simplified, if the coefficients in the axis-system transformation of the gradient of the electric field of the outer charges at the coupled nucleus are arranged as spherical components λμ,ν(2). Then the reduced matrix elements of the field gradient operators in a symmetric top eigenfunction basis, including their dependence on the molecule-fixed z-angular momentum component k, can be determined from the knowledge of those of λ(2) . The hyperfine structure Hamiltonian Hq is expressed as the sum of terms characterized each by a value of the molecule-fixed index ν, whose matrix elements obey the rule Δk = ν. Some of these terms may vanish because of molecular symmetry, and the specific cases of linear and symmetric top molecules, orthorhombic molecules, and molecules with symmetry lower than orthorhombic are considered. Each ν-term consists of a contraction of the rotational tensor λ(2) and the nuclear quadrupole tensor in the space-fixed frame, and its matrix elements in the rotation-nuclear spin coupled representation can be determined by the standard spherical tensor methods.

Space-plasma campaign on UCLA's Large Plasma Device (LAPD)

NASA Astrophysics Data System (ADS)

Koepke, M. E.; Finnegan, S. M.; Knudsen, D. J.; Vincena, S.

2007-05-01

Knudsen [JGR, 1996] describes a potential role for stationary Alfvén (StA) waves in auroral arcs' frequency dependence. Magnetized plasmas are predicted to support electromagnetic perturbations that are static in a fixed frame if there is uniform background plasma convection. These stationary waves should not be confused with standing waves that oscillate in time with a fixed, spatially varying envelope. Stationary waves have no time variation in the fixed frame. In the drifting frame, there is an apparent time dependence as plasma convects past fixed electromagnetic structures. We describe early results from an experimental campaign to reproduce in the lab the basic conditions necessary for the creation of StA waves, namely quasi-steady-state convection across magnetic field-aligned current channels. We show that an off-axis, fixed channel of electron current (and depleted density) is created in the Large Plasma Device Upgrade (LAPD) at UCLA, using a small, heated, oxide-coated electrode at one plasma-column end and we show that the larger plasma column rotates about its cylindrical axis from a radial electric field imposed by a special termination electrode on the same end. Initial experimentation with plasma-rotation-inducing termination electrodes began in May 2006 in the West Virginia Q Machine, leading to two designs that, in January 2007, were tested in LAPD. The radial profile of azimuthal velocity was consistent with predictions of rigid-body rotation. Current-channel experiments in LAPD, in August 2006, showed that inertial Alfvén waves could be concentrated in an off-axis channel of electron current and depleted plasma density. These experimental results will be presented and discussed. This research is supported by DOE and NSF.

Flow cytometric method for measuring chromatin fragmentation in fixed sperm from yellow perch (Perca flavescens)

USGS Publications Warehouse

Jenkins, Jill A.; Draugelis-Dale, Rassa O.; Pinkney, Alfred E.; Iwanowicz, Luke R.; Blazer, Vicki

2015-01-01

Declining harvests of yellow perch, Perca flavescens, in urbanized watersheds of Chesapeake Bay have prompted investigations of their reproductive fitness. The purpose of this study was to establish a flow cytometric technique for DNA analysis of fixed samples sent from the field to provide reliable gamete quality measurements. Similar to the sperm chromatin structure assay, measures were made on the susceptibility of nuclear DNA to acid-induced denaturation, but used fixed rather than live or thawed cells. Nuclei were best exposed to the acid treatment for 1 minute at 37 °C followed by the addition of cold (4 °C) propidium iodide staining solution before flow cytometry. The rationale for protocol development is presented graphically through cytograms. Field results collected in 2008 and 2009 revealed DNA fragmentation up to 14.5%. In 2008, DNA fragmentation from the more urbanized watersheds was significantly greater than from reference sites (P = 0.026) and in 2009, higher percentages of haploid testicular cells were noted from the less urbanized watersheds (P = 0.032) indicating better reproductive condition at sites with less urbanization. For both years, total and progressive live sperm motilities by computer-assisted sperm motion analysis ranged from 19.1% to 76.5%, being significantly higher at the less urbanized sites (P < 0.05). This flow cytometric method takes advantage of the propensity of fragmented DNA to be denatured under standard conditions, or 1 minute at 37 °C with 10% buffered formalin–fixed cells. The study of fixed sperm makes possible the restrospective investigation of germplasm fragmentation, spermatogenic ploidy patterns, and chromatin compaction levels from samples translocated over distance and time. The protocol provides an approach that can be modified for other species across taxa.

Cytology specimens offer an effective alternative to formalin-fixed tissue as demonstrated by novel automated detection for ALK break-apart FISH testing and immunohistochemistry in lung adenocarcinoma.

PubMed

Rosenblum, Frida; Hutchinson, Lloyd M; Garver, Joann; Woda, Bruce; Cosar, Ediz; Kurian, Elizabeth M

2014-11-01

Minimally invasive sampling by cytology or core needle biopsy often provides an initial diagnosis for treatment in patients with lung nodules. From these limited specimens, multiple molecular studies are frequently requested. Current guidelines from the US Food and Drug Administration recommend using formalin-fixed paraffin-embedded tissue sections for the detection of anaplastic lymphoma kinase (ALK) gene rearrangement by fluorescence in situ hybridization (FISH). The authors compared alcohol-fixed and formalin-fixed cytology specimens using a novel automated detection for ALK rearrangements by FISH and immunohistochemistry (IHC). ALK FISH testing was performed on 129 lung adenocarcinomas from 71 cytology cases and 58 biopsy/resection specimens using Papanicolaou staining with integrated cytomorphology. IHC with the ALK D5F3 antibody was performed on cases with residual material (88 of 129 cases). The mean age of the patients was 66 years; there were 62 women and 67 men. ALK gene rearrangement was present in 4% of cytology specimens (3 of 71 specimens) and 7% of surgical specimens (4 of 58 specimens). FISH in 13 cases was technically unsuccessful. Of the 7 FISH-positive cases, only 2 cytology cases (4%) and 2 surgical cases (6%) were found to be positive with the ALK antibody, demonstrating 80% concordance. The one case found to be negative for ALK by IHC demonstrated a variant rearrangement of the ALK 2p23 gene locus by FISH. The results of the current study validate the usefulness of alcohol-fixed and/or formalin-fixed cytology specimens for ALK rearrangement by a novel automated FISH method. IHC using the D5F3 antibody for ALK is specific in this limited cohort. The authors also demonstrated that alcohol-fixed cytology specimens can be used for ALK rearrangement by automated FISH, alone or in conjunction with IHC. © 2014 American Cancer Society.

Differences in night-time and daytime ambulatory blood pressure when diurnal periods are defined by self-report, fixed-times, and actigraphy: Improving the Detection of Hypertension study.

PubMed

Booth, John N; Muntner, Paul; Abdalla, Marwah; Diaz, Keith M; Viera, Anthony J; Reynolds, Kristi; Schwartz, Joseph E; Shimbo, Daichi

2016-02-01

To determine whether defining diurnal periods by self-report, fixed-time, or actigraphy produce different estimates of night-time and daytime ambulatory blood pressure (ABP). Over a median of 28 days, 330 participants completed two 24-h ABP and actigraphy monitoring periods with sleep diaries. Fixed night-time and daytime periods were defined as 0000-0600 h and 1000-2000 h, respectively. Using the first ABP period, within-individual differences for mean night-time and daytime ABP and kappa statistics for night-time and daytime hypertension (systolic/diastolic ABP≥120/70 mmHg and ≥135/85 mmHg, respectively) were estimated comparing self-report, fixed-time, or actigraphy for defining diurnal periods. Reproducibility of ABP was also estimated. Within-individual mean differences in night-time systolic ABP were small, suggesting little bias, when comparing the three approaches used to define diurnal periods. The distribution of differences, represented by 95% confidence intervals (CI), in night-time systolic and diastolic ABP and daytime systolic and diastolic ABP was narrowest for self-report versus actigraphy. For example, mean differences (95% CI) in night-time systolic ABP for self-report versus fixed-time was -0.53 (-6.61, +5.56) mmHg, self-report versus actigraphy was 0.91 (-3.61, +5.43) mmHg, and fixed-time versus actigraphy was 1.43 (-5.59, +8.46) mmHg. Agreement for night-time and daytime hypertension was highest for self-report versus actigraphy: kappa statistic (95% CI) = 0.91 (0.86,0.96) and 1.00 (0.98,1.00), respectively. The reproducibility of mean ABP and hypertension categories was similar using each approach. Given the high agreement with actigraphy, these data support using self-report to define diurnal periods on ABP monitoring. Further, the use of fixed-time periods may be a reasonable alternative approach.

Document page structure learning for fixed-layout e-books using conditional random fields

NASA Astrophysics Data System (ADS)

Tao, Xin; Tang, Zhi; Xu, Canhui

2013-12-01

In this paper, a model is proposed to learn logical structure of fixed-layout document pages by combining support vector machine (SVM) and conditional random fields (CRF). Features related to each logical label and their dependencies are extracted from various original Portable Document Format (PDF) attributes. Both local evidence and contextual dependencies are integrated in the proposed model so as to achieve better logical labeling performance. With the merits of SVM as local discriminative classifier and CRF modeling contextual correlations of adjacent fragments, it is capable of resolving the ambiguities of semantic labels. The experimental results show that CRF based models with both tree and chain graph structures outperform the SVM model with an increase of macro-averaged F1 by about 10%.

Minimax confidence intervals in geomagnetism

NASA Technical Reports Server (NTRS)

Stark, Philip B.

1992-01-01

The present paper uses theory of Donoho (1989) to find lower bounds on the lengths of optimally short fixed-length confidence intervals (minimax confidence intervals) for Gauss coefficients of the field of degree 1-12 using the heat flow constraint. The bounds on optimal minimax intervals are about 40 percent shorter than Backus' intervals: no procedure for producing fixed-length confidence intervals, linear or nonlinear, can give intervals shorter than about 60 percent the length of Backus' in this problem. While both methods rigorously account for the fact that core field models are infinite-dimensional, the application of the techniques to the geomagnetic problem involves approximations and counterfactual assumptions about the data errors, and so these results are likely to be extremely optimistic estimates of the actual uncertainty in Gauss coefficients.

Shuttle-promoted nano-mechanical current switch

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

Song, Taegeun, E-mail: tsong@ictp.it; Kiselev, Mikhail N.; Gorelik, Leonid Y.

2015-09-21

We investigate electron shuttling in three-terminal nanoelectromechanical device built on a movable metallic rod oscillating between two drains. The device shows a double-well shaped electromechanical potential tunable by a source-drain bias voltage. Four stationary regimes controllable by the bias are found for this device: (i) single stable fixed point, (ii) two stable fixed points, (iii) two limit cycles, and (iv) single limit cycle. In the presence of perpendicular magnetic field, the Lorentz force makes possible switching from one electromechanical state to another. The mechanism of tunable transitions between various stable regimes based on the interplay between voltage controlled electromechanical instabilitymore » and magnetically controlled switching is suggested. The switching phenomenon is implemented for achieving both a reliable active current switch and sensoring of small variations of magnetic field.« less

In-flight calibration and performance evaluation of the fixed head star trackers for the solar maximum mission

NASA Technical Reports Server (NTRS)

Thompson, R. H.; Gambardella, P. J.

1980-01-01

The Solar Maximum Mission (SMM) spacecraft provides an excellent opportunity for evaluating attitude determination accuracies achievable with tracking instruments such as fixed head star trackers (FHSTs). As a part of its payload, SMM carries a highly accurate fine pointing Sun sensor (FPSS). The EPSS provides an independent check of the pitch and yaw parameters computed from observations of stars in the FHST field of view. A method to determine the alignment of the FHSTs relative to the FPSS using spacecraft data is applied. Two methods that were used to determine distortions in the 8 degree by 8 degree field of view of the FHSTs using spacecraft data are also presented. The attitude determination accuracy performance of the in flight calibrated FHSTs is evaluated.

Shared social responsibility: a field experiment in pay-what-you-want pricing and charitable giving.

PubMed

Gneezy, Ayelet; Gneezy, Uri; Nelson, Leif D; Brown, Amber

2010-07-16

A field experiment (N = 113,047 participants) manipulated two factors in the sale of souvenir photos. First, some customers saw a traditional fixed price, whereas others could pay what they wanted (including $0). Second, approximately half of the customers saw a variation in which half of the revenue went to charity. At a standard fixed price, the charitable component only slightly increased demand, as similar studies have also found. However, when participants could pay what they wanted, the same charitable component created a treatment that was substantially more profitable. Switching from corporate social responsibility to what we term shared social responsibility works in part because customized contributions allow customers to directly express social welfare concerns through the purchasing of material goods.

Efficiency turns the table on neural encoding, decoding and noise.

PubMed

Deneve, Sophie; Chalk, Matthew

2016-04-01

Sensory neurons are usually described with an encoding model, for example, a function that predicts their response from the sensory stimulus using a receptive field (RF) or a tuning curve. However, central to theories of sensory processing is the notion of 'efficient coding'. We argue here that efficient coding implies a completely different neural coding strategy. Instead of a fixed encoding model, neural populations would be described by a fixed decoding model (i.e. a model reconstructing the stimulus from the neural responses). Because the population solves a global optimization problem, individual neurons are variable, but not noisy, and have no truly invariant tuning curve or receptive field. We review recent experimental evidence and implications for neural noise correlations, robustness and adaptation. Copyright © 2016. Published by Elsevier Ltd.

Fibroblast Activation Protein-Alpha, a Serine Protease that Facilitates Metastasis by Modification of Diverse Microenvironments

DTIC Science & Technology

2011-10-01

lung tissue. We were not able to detect sufficient numbers of cells in this manner. We tried a different procedure for fixing the lungs after they...added after 24 hours. The films were fixed and evaluated microscopically. In four trials, 10 random microscopic fields were selected and... dosing by oral gavage once daily with 1.3 mg/kg L-valine-L-boroproline called talabostat (extracellular & intracellular DASH), 13.3 mg/kg L- glutamyl

Optimal strategies for the control of autonomous vehicles in data assimilation

NASA Astrophysics Data System (ADS)

McDougall, D.; Moore, R. O.

2017-08-01

We propose a method to compute optimal control paths for autonomous vehicles deployed for the purpose of inferring a velocity field. In addition to being advected by the flow, the vehicles are able to effect a fixed relative speed with arbitrary control over direction. It is this direction that is used as the basis for the locally optimal control algorithm presented here, with objective formed from the variance trace of the expected posterior distribution. We present results for linear flows near hyperbolic fixed points.

Corruption of accuracy and efficiency of Markov chain Monte Carlo simulation by inaccurate numerical implementation of conceptual hydrologic models

NASA Astrophysics Data System (ADS)

Schoups, G.; Vrugt, J. A.; Fenicia, F.; van de Giesen, N. C.

2010-10-01

Conceptual rainfall-runoff models have traditionally been applied without paying much attention to numerical errors induced by temporal integration of water balance dynamics. Reliance on first-order, explicit, fixed-step integration methods leads to computationally cheap simulation models that are easy to implement. Computational speed is especially desirable for estimating parameter and predictive uncertainty using Markov chain Monte Carlo (MCMC) methods. Confirming earlier work of Kavetski et al. (2003), we show here that the computational speed of first-order, explicit, fixed-step integration methods comes at a cost: for a case study with a spatially lumped conceptual rainfall-runoff model, it introduces artificial bimodality in the marginal posterior parameter distributions, which is not present in numerically accurate implementations of the same model. The resulting effects on MCMC simulation include (1) inconsistent estimates of posterior parameter and predictive distributions, (2) poor performance and slow convergence of the MCMC algorithm, and (3) unreliable convergence diagnosis using the Gelman-Rubin statistic. We studied several alternative numerical implementations to remedy these problems, including various adaptive-step finite difference schemes and an operator splitting method. Our results show that adaptive-step, second-order methods, based on either explicit finite differencing or operator splitting with analytical integration, provide the best alternative for accurate and efficient MCMC simulation. Fixed-step or adaptive-step implicit methods may also be used for increased accuracy, but they cannot match the efficiency of adaptive-step explicit finite differencing or operator splitting. Of the latter two, explicit finite differencing is more generally applicable and is preferred if the individual hydrologic flux laws cannot be integrated analytically, as the splitting method then loses its advantage.

Homogenization of Winkler-Steklov spectral conditions in three-dimensional linear elasticity

NASA Astrophysics Data System (ADS)

Gómez, D.; Nazarov, S. A.; Pérez, M. E.

2018-04-01

We consider a homogenization Winkler-Steklov spectral problem that consists of the elasticity equations for a three-dimensional homogeneous anisotropic elastic body which has a plane part of the surface subject to alternating boundary conditions on small regions periodically placed along the plane. These conditions are of the Dirichlet type and of the Winkler-Steklov type, the latter containing the spectral parameter. The rest of the boundary of the body is fixed, and the period and size of the regions, where the spectral parameter arises, are of order ɛ . For fixed ɛ , the problem has a discrete spectrum, and we address the asymptotic behavior of the eigenvalues {β _k^ɛ }_{k=1}^{∞} as ɛ → 0. We show that β _k^ɛ =O(ɛ ^{-1}) for each fixed k, and we observe a common limit point for all the rescaled eigenvalues ɛ β _k^ɛ while we make it evident that, although the periodicity of the structure only affects the boundary conditions, a band-gap structure of the spectrum is inherited asymptotically. Also, we provide the asymptotic behavior for certain "groups" of eigenmodes.