Rural roads and bridges : financing local roads and bridges in rural areas

DOT National Transportation Integrated Search

1997-01-01

This report examines the arrangements used by counties and towns to finance local roads and bridges and compares current patterns with those recorded during the 1980s. Three data sources were utilized: FHWA's Highway Statistics series; the Census of ...

Suspension Bridges: A Merger of Physics, Engineering, and Art

ERIC Educational Resources Information Center

Greenslade, Thomas B., Jr.

1974-01-01

Discusses the physical principles underlying the design of a small scale suspension bridge, including its types and strength calculations. Included are the working equation and two formulas for determining the load per unit length. (CC)

Bridging the Vector Calculus Gap

NASA Astrophysics Data System (ADS)

Dray, Tevian; Manogue, Corinne

2003-05-01

As with Britain and America, mathematicians and physicists are separated from each other by a common language. In a nutshell, mathematics is about functions, but physics is about things. For the last several years, we have led an NSF-supported effort to "bridge the vector calculus gap" between mathematics and physics. The unifying theme we have discovered is to emphasize geometric reasoning, not (just) algebraic computation. In this talk, we will illustrate the language differences between mathematicians and physicists, and how we are trying reconcile them in the classroom. For further information about the project go to: http://www.physics.orst.edu/bridge

Note: A non-invasive electronic measurement technique to measure the embedded four resistive elements in a Wheatstone bridge sensor

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

Ravelo Arias, S. I.; Ramírez Muñoz, D.; Cardoso, S.

2015-06-15

The work shows a measurement technique to obtain the correct value of the four elements in a resistive Wheatstone bridge without the need to separate the physical connections existing between them. Two electronic solutions are presented, based on a source-and-measure unit and using discrete electronic components. The proposed technique brings the possibility to know the mismatching or the tolerance between the bridge resistive elements and then to pass or reject it in terms of its related common-mode rejection. Experimental results were taken in various Wheatstone resistive bridges (discrete and magnetoresistive integrated bridges) validating the proposed measurement technique specially when themore » bridge is micro-fabricated and there is no physical way to separate one resistive element from the others.« less

Reliability-based criteria for load and resistance factor design code for wood bridges

Treesearch

Chris Eamon; Andrzej S. Nowak; Michael A. Ritter; Joe Murphy

2000-01-01

Recently AASHTO adopted a load and resistance factor design code for highway bridges. The new code provides a rational basis for the design of steel and concrete structures. However, the calibration was not done for wood bridges. Therefore, there is a need to fill this gap. The development of statistical models for wood bridge structures is discussed. Recent test...

Diagnosing alternative conceptions of Fermi energy among undergraduate students

NASA Astrophysics Data System (ADS)

Sharma, Sapna; Ahluwalia, Pardeep Kumar

2012-07-01

Physics education researchers have scientifically established the fact that the understanding of new concepts and interpretation of incoming information are strongly influenced by the preexisting knowledge and beliefs of students, called epistemological beliefs. This can lead to a gap between what students actually learn and what the teacher expects them to learn. In a classroom, as a teacher, it is desirable that one tries to bridge this gap at least on the key concepts of a particular field which is being taught. One such key concept which crops up in statistical physics/solid-state physics courses, and around which the behaviour of materials is described, is Fermi energy (εF). In this paper, we present the results which emerged about misconceptions on Fermi energy in the process of administering a diagnostic tool called the Statistical Physics Concept Survey developed by the authors. It deals with eight themes of basic importance in learning undergraduate solid-state physics and statistical physics. The question items of the tool were put through well-established sequential processes: definition of themes, Delphi study, interview with students, drafting questions, administration, validity and reliability of the tool. The tool was administered to a group of undergraduate students and postgraduate students, in a pre-test and post-test design. In this paper, we have taken one of the themes i.e. Fermi energy of the diagnostic tool for our analysis and discussion. Students’ responses and reasoning comments given during interview were analysed. This analysis helped us to identify prevailing misconceptions/learning gaps among students on this topic. How spreadsheets can be effectively used to remove the identified misconceptions and help appreciate the finer nuances while visualizing the behaviour of the system around Fermi energy, normally sidestepped both by the teachers and learners, is also presented in this paper.

Modeling of the dielectric permittivity of porous soil media with water using statistical-physical models

NASA Astrophysics Data System (ADS)

Usowicz, Boguslaw; Marczewski, Wojciech; Usowicz, Jerzy B.; Łukowski, Mateusz; Lipiec, Jerzy; Stankiewicz, Krystyna

2013-04-01

Radiometric observations with SMOS rely on the Radiation Transfer Equations (RTE) determining the Brightness Temperature (BT) in two linear polarization components (H, V) satisfying Fresnel principle of propagation in horizontally layered target media on the ground. RTE involve variables which bound the equations expressed in Electro-Magnetic (EM) terms of the intensity BT to the physical reality expressed by non-EM variables (Soil Moisture (SM), vegetation indexes, fractional coverage with many different properties, and the boundary conditions like optical thickness, layer definitions, roughness, etc.) bridging the EM domain to other physical aspects by means of the so called tau-omega methods. This method enables joining variety of different valuable models, including specific empirical estimation of physical properties in relation to the volumetric water content. The equations of RTE are in fact expressed by propagation, reflection and losses or attenuation existing on a considered propagation path. The electromagnetic propagation is expressed in the propagation constant. For target media on the ground the dielectric constant is a decisive part for effects of propagation. Therefore, despite of many various physical parameters involved, one must effectively and dominantly rely on the dielectric constant meant as a complex variable. The real part of the dielectric constant represents effect of apparent shortening the propagation path and the refraction, while the imaginary part is responsible for the attenuation or losses. This work engages statistical-physical modeling of soil properties considering the media as a mixture of solid grains, and gas or liquid filling of pores and contact bridges between compounds treated statistically. The method of this modeling provides an opportunity of characterizing the porosity by general statistical means, and is applicable to various physical properties (thermal, electrical conductivity and dielectric properties) which depend on composition of compounds. The method was developed beyond the SMOS method, but they meet just in RTE, at the dielectric constant. The dielectric constant is observed or measured (retrieved) by SMOS, regardless other properties like the soil porosity and without a direct relation to thermal properties of soils. Relations between thermal properties of soil to the water content are very consistent. Therefore, we took a concept of introducing effects of the soil porosity, and thermal properties of soils into the representation of the dielectric constant in complex measures, and thus gaining new abilities for capturing effects of the porosity by the method of SMOS observations. Currently we are able presenting few effects of relations between thermal properties and the soil moisture content, on examples from wetlands Biebrza and Polesie in Poland, and only search for correlations between SM from SMOS to the moisture content known from the ground. The correlations are poor for SMOS L2 data processed with the version of retrievals using the model of Dobson (501), but we expect more correlation for the version using the model of Mironov (551). If the supposition is confirmed, then we may gain encouragement to employing the statistical-physical modeling of the dielectric constant and thermal properties for the purposes of using this model in RTE and tau-omega method. Treating the soil porosity for a target of research directly is not enough strongly motivated like the use of effects on SM observable in SMOS.

StreamStats: a U.S. geological survey web site for stream information

USGS Publications Warehouse

Kernell, G. Ries; Gray, John R.; Renard, Kenneth G.; McElroy, Stephen A.; Gburek, William J.; Canfield, H. Evan; Scott, Russell L.

2003-01-01

The U.S. Geological Survey has developed a Web application, named StreamStats, for providing streamflow statistics, such as the 100-year flood and the 7-day, 10-year low flow, to the public. Statistics can be obtained for data-collection stations and for ungaged sites. Streamflow statistics are needed for water-resources planning and management; for design of bridges, culverts, and flood-control structures; and for many other purposes. StreamStats users can point and click on data-collection stations shown on a map in their Web browser window to obtain previously determined streamflow statistics and other information for the stations. Users also can point and click on any stream shown on the map to get estimates of streamflow statistics for ungaged sites. StreamStats determines the watershed boundaries and measures physical and climatic characteristics of the watersheds for the ungaged sites by use of a Geographic Information System (GIS), and then it inserts the characteristics into previously determined regression equations to estimate the streamflow statistics. Compared to manual methods, StreamStats reduces the average time needed to estimate streamflow statistics for ungaged sites from several hours to several minutes.

Investigation of mechanistic deterioration modeling for bridge design and management.

DOT National Transportation Integrated Search

2017-04-01

The ongoing deterioration of highway bridges in Colorado dictates that an effective method for allocating limited management resources be developed. In order to predict bridge deterioration in advance, mechanistic models that analyze the physical pro...

Global Precipitation Measurement (GPM) Ground Validation (GV) Science Implementation Plan

NASA Technical Reports Server (NTRS)

Petersen, Walter A.; Hou, Arthur Y.

2008-01-01

For pre-launch algorithm development and post-launch product evaluation Global Precipitation Measurement (GPM) Ground Validation (GV) goes beyond direct comparisons of surface rain rates between ground and satellite measurements to provide the means for improving retrieval algorithms and model applications.Three approaches to GPM GV include direct statistical validation (at the surface), precipitation physics validation (in a vertical columns), and integrated science validation (4-dimensional). These three approaches support five themes: core satellite error characterization; constellation satellites validation; development of physical models of snow, cloud water, and mixed phase; development of cloud-resolving model (CRM) and land-surface models to bridge observations and algorithms; and, development of coupled CRM-land surface modeling for basin-scale water budget studies and natural hazard prediction. This presentation describes the implementation of these approaches.

Characterization of stormwater runoff from bridge decks in eastern Massachusetts, 2014–16

USGS Publications Warehouse

Smith, Kirk P.; Sorenson, Jason R.; Granato, Gregory E.

2018-05-02

The quality of stormwater runoff from bridge decks (hereafter referred to as “bridge-deck runoff”) was characterized in a field study from August 2014 through August 2016 in which concentrations of suspended sediment (SS) and total nutrients were monitored. These new data were collected to supplement existing highway-runoff data collected in Massachusetts which were deficient in bridge-deck runoff concentration data. Monitoring stations were installed at three bridges maintained by the Massachusetts Department of Transportation in eastern Massachusetts (State Route 2A in the city of Boston, Interstate 90 in the town of Weston, and State Route 20 near Quinsigamond Village in the city of Worcester). The bridges had annual average daily traffic volumes from 21,200 to 124,000 vehicles per day; the land use surrounding the monitoring stations was 25 to 67 percent impervious.Automatic-monitoring techniques were used to collect more than 160 flow-proportional composite samples of bridge-deck runoff. Samples were analyzed for concentrations of SS, loss on ignition of suspended solids (LOI), particulate carbon (PC), total phosphorus (TP), total dissolved nitrogen (DN), and particulate nitrogen (PN). The distribution of particle size of SS also was determined for composite samples. Samples of bridge-deck runoff were collected year round during rain, mixed precipitation, and snowmelt runoff and with different dry antecedent periods throughout the 2-year sampling period.At the three bridge-deck-monitoring stations, median concentrations of SS in composite samples of bridge-deck runoff ranged from 1,490 to 2,020 milligrams per liter (mg/L); however, the range of SS in individual composites was vast at 44 to 142,000 mg/L. Median concentrations of SS were similar in composite samples collected from the State Route 2A and Interstate 90 bridge (2,010 and 2,020 mg/L, respectively), and lowest at the State Route 20 bridge (1,490 mg/L). Concentrations of coarse sediment (greater than 0.25 millimeters in diameter) dominated the SS matrix by more than an order of magnitude. Concentrations of LOI and PC in composite samples ranged from 15 to 1,740 mg/L and 6.68 to 1,360 mg/L, respectively, and generally represented less than 10 and 3 percent of the median mass of SS, respectively. Concentrations of TP in composite samples ranged from 0.09 to 7.02 mg/L; median concentrations of TP ranged from 0.505 to 0.69 mg/L and were highest on the bridge on State Route 2A in Boston. Concentrations of total nitrogen (TN) (sum DN and PN) in composite samples were variable (0.36 to 29 mg/L). Median DN (0.64 to 0.90 mg/L) concentrations generally represented about 40 percent of the TN concentration at each bridge and were similar to annual volume-weighted mean concentrations of nitrogen in precipitation in Massachusetts.Nonparametric statistical methods were used to test for differences between sample constituent concentrations among the three bridges. These results indicated that there are no statistically significant differences for concentrations of SS, LOI, PC, and TP among the three bridges (one-way analysis of variance test on rank-transformed data, 95-percent confidence level). Test results for concentrations of TN in composite samples indicated that concentrations of TN collected on State Route 20 near Quinsigamond Village were significantly higher than those concentrations collected on State Route 2A in Boston and Interstate 90 near Weston. Median concentrations of TN were about 93 and 55 percent lower at State Route 2A and at Interstate 90, respectively, compared to the median concentrations of TN at State Route 20.Samples of sediment were collected from five fixed locations on each bridge on three occasions during dry weather to calculate semiquantitative distributions of sediment yields on the bridge surface relative to the monitoring location. Mean yields of bridge-deck sediment during this study for State Route 2A in Boston, Interstate 90 near Weston, and State Route 20 near Quinsigamond Village were 1,500, 250, and 5,700 pounds per curb-mile, respectively. Sediment yields at each sampling location varied widely (26 to 25,000 pounds per curb-mile) but were similar to yields reported elsewhere in Massachusetts and the United States. Yields calculated for each sampling location indicated that the sediment was not evenly distributed across each bridge in this study for plausible reasons such as bridge slope, vehicular tracking, and bridge deterioration.Bridge-deck sediment quality was largely affected by the distribution of sediment particle size. Concentrations of TP in the fine sediment-size fraction (less than 0.0625 millimeter in diameter) of samples of bridge-deck sediment were about 6 times greater than in the coarse size fraction. Concentrations for many total-recoverable metals were 2 to 17 times greater in the fine size fraction compared to concentrations in the coarse size fraction (greater than or equal to 0.25 millimeter in diameter), and concentrations of total-recoverable copper and lead in the fine size fraction were 2 to 65 times higher compared to concentrations in the intermediate (greater than or equal to 0.0625 to 0.25 millimeter in diameter) or the coarse size fraction. However, the proportion of sediment particles less than 0.0625 millimeter in diameter in composite samples of bridge-deck runoff was small (median values range from 4 to 8 percent at each bridge) compared to the larger sediment particle-size mass. As a result, more than 50 percent of the sediment-associated TP, aluminum, chromium, manganese, and nickel was estimated to be associated with the coarse size fraction of the SS load. In contrast, about 95 percent of the estimated sediment-associated copper concentration was associated with the fine size fraction of the SS load.Version 1.0.2 of the Stochastic Empirical Loading and Dilution Model was used to simulate long-term (29–30-year) concentrations and annual yields of SS, TP, and TN in bridge-deck runoff and in discharges from a hypothetical stormwater treatment best-management practice structure. Three methods (traditional statistics, robust statistics, and L-moments) were used to calculate statistics for stochastic simulations because the high variability in measured concentration values during the field study resulted in extreme simulated concentrations. Statistics of each dataset, including the average, standard deviation, and skew of the common (base 10) logarithms, for each of the three bridges, and for a lumped dataset, were calculated and used for simulations; statistics representing the median of statistics calculated for the three bridges also were used for simulations. These median statistics were selected for the interpretive simulations so that the simulations could be used to estimate concentrations and yields from other, unmonitored bridges in Massachusetts. Comparisons of the standard and robust statistics indicated that simulation results with either method would be similar, which indicated that the large variability in simulated results was not caused by a few outliers. Comparison to statistics calculated by the L-moments methods indicated that L-moments do not produce extreme concentrations; however, they also do not produce results that represent the bulk of concentration data.The runoff-quality risk analysis indicated that bridge-deck runoff would exceed discharge standards commonly used for large, advanced wastewater treatment plants, but that commonly used stormwater best-management practices may reduce the percentage of exceedances by one-half. Results of simulations indicated that long-term average yields of TN, TP, and SS may be about 21.4, 6.44, and 40,600 pounds per acre per year, respectively. These yields are about 1.3, 3.4, and 16 times simulated ultra-urban highway yields in Massachusetts; however, simulations indicated that use of a best-management practice structure to treat bridge-deck runoff may reduce discharge yields to about 10, 2.8, and 4,300, pounds per acre per year, respectively.

Cal-Bridge and CAMPARE: Engaging Underrepresented Students in Physics and Astronomy

NASA Astrophysics Data System (ADS)

Rudolph, Alexander L.; Cal-Bridge and CAMPARE Teams

2018-01-01

We describe two programs, Cal-Bridge and CAMPARE, with the common mission of increasing participation of groups traditionally underrepresented in astronomy, through summer research opportunities, in the case of CAMPARE, scholarships in the case of Cal-Bridge, and significant mentoring in both programs, creating a national impact on their numbers successfully pursuing a PhD in the field.In 8 years, the CAMPARE program has sent 112 students, >80% from underrepresented groups, to conduct summer research at one of 14 major research institutions throughout the country. Of the CAMPARE scholars who have graduated with a Bachelor’s degree, almost two-thirds (65%) have completed or are pursuing graduate education in physics, astronomy, or a related field, at institutions including UCLA, UC Riverside, UC Irvine, UC Santa Barbara, USC, Stanford, Univ. of Arizona, Univ. of Washington, Univ. of Rochester, Michigan State Univ., Georgia Tech, Georgia State Univ., Kent State, Indiana Univ., Univ. of Oregon, Syracuse Univ., Montana State Univ., and the Fisk-Vanderbilt Master’s-to-PhD program.Now entering its fourth year, the Cal-Bridge program is a CSU-UC Bridge program comprised of >140 physics and astronomy faculty from 9 University of California (UC), 15 California State University (CSU), and 30 California Community College (CCC) campuses throughout California. In the first four years, 34 Cal-Bridge Scholars have been selected, including 22 Hispanic, 3 African-American and 13 women students, 10 of whom are from URM groups. Thirty (30) of the 34 Cal-Bridge Scholars are first generation college students. In the last two years, 11 of 13 Cal-Bridge Scholars have begun PhD programs in physics or astronomy at top PhD programs nationally. Three (3) of these 11 scholars have won NSF Graduate Research Fellowships; one more received an Honorable Mention. The next cohort applies this fall.Cal-Bridge provides much deeper mentoring and professional development experiences over the last two years of undergraduate and first year of graduate school to students from this diverse network of higher education institutions. Cal-Bridge Scholars benefit from substantial financial support, intensive, joint mentoring by CSU and UC faculty, professional development workshops, and exposure to research opportunities at the participating UC campuses.

Enhancing Diversity in Physics: The Fisk-Vanderbilt Masters-to-PhD Bridge Program

NASA Astrophysics Data System (ADS)

Stassun, Keivan

2010-03-01

We describe the Fisk-Vanderbilt Masters-to-PhD Bridge program as a model for partnering with minority-serving institutions to increase the representation of women and minorities earning PhDs in astronomy and related disciplines. Since its inception in 2004, the Fisk-Vanderbilt Bridge program has attracted 30 minority students, 60% of whom are female, and with a retention rate of 94%. When the first Bridge students completed their PhDs in 2010-11, the program will become the top awarder of astronomy PhDs to underrepresented minorities in the United States. Already, Fisk has become the top producer of physics Masters degrees to African Americans. We summarize the program's structure, approach, and research basis with the goal of providing a replicable model for other institutions seeking to build similar collaborative, research-based bridging partnerships.

Unfolding single RNA molecules: bridging the gap between equilibrium and non-equilibrium statistical thermodynamics.

PubMed

Bustamante, Carlos

2005-11-01

During the last 15 years, scientists have developed methods that permit the direct mechanical manipulation of individual molecules. Using this approach, they have begun to investigate the effect of force and torque in chemical and biochemical reactions. These studies span from the study of the mechanical properties of macromolecules, to the characterization of molecular motors, to the mechanical unfolding of individual proteins and RNA. Here I present a review of some of our most recent results using mechanical force to unfold individual molecules of RNA. These studies make it possible to follow in real time the trajectory of each molecule as it unfolds and characterize the various intermediates of the reaction. Moreover, if the process takes place reversibly it is possible to extract both kinetic and thermodynamic information from these experiments at the same time that we characterize the forces that maintain the three-dimensional structure of the molecule in solution. These studies bring us closer to the biological unfolding processes in the cell as they simulate in vitro, the mechanical unfolding of RNAs carried out in the cell by helicases. If the unfolding process occurs irreversibly, I show here that single-molecule experiments can still provide equilibrium, thermodynamic information from non-equilibrium data by using recently discovered fluctuation theorems. Such theorems represent a bridge between equilibrium and non-equilibrium statistical mechanics. In fact, first derived in 1997, the first experimental demonstration of the validity of fluctuation theorems was obtained by unfolding mechanically a single molecule of RNA. It is perhaps a sign of the times that important physical results are these days used to extract information about biological systems and that biological systems are being used to test and confirm fundamental new laws in physics.

Time-resolved observation of thermally activated rupture of a capillary-condensed water nanobridge

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

Bak, Wan; Sung, Baekman; Kim, Jongwoo

2015-01-05

The capillary-condensed liquid bridge is one of the most ubiquitous forms of liquid in nature and contributes significantly to adhesion and friction of biological molecules as well as microscopic objects. Despite its important role in nanoscience and technology, the rupture process of the bridge is not well understood and needs more experimental works. Here, we report real-time observation of rupture of a capillary-condensed water nanobridge in ambient condition. During slow and stepwise stretch of the nanobridge, we measured the activation time for rupture, or the latency time required for the bridge breakup. By statistical analysis of the time-resolved distribution ofmore » activation time, we show that rupture is a thermally activated stochastic process and follows the Poisson statistics. In particular, from the Arrhenius law that the rupture rate satisfies, we estimate the position-dependent activation energies for the capillary-bridge rupture.« less

Cal-Bridge and CAMPARE: Engaging Underrepresented Students in Physics and Astronomy

NASA Astrophysics Data System (ADS)

Rudolph, Alexander L.; Smecker-Hane, Tammy A.; Cal-Bridge Team; CAMPARE Team

2018-06-01

We describe two programs, Cal-Bridge and CAMPARE, with the common mission of increasing participation of groups traditionally underrepresented in astronomy, through summer research opportunities, in the case of CAMPARE, scholarships in the case of Cal-Bridge, and significant mentoring in both programs, creating a national impact on their numbers successfully pursuing a PhD in the field. In 9 years, the CAMPARE program has sent 150 students, >80% from underrepresented groups, to conduct summer research at one of 14 major research institutions throughout the country. Of the CAMPARE scholars who have graduated with a Bachelor’s degree, almost two-thirds (65%) have completed or are pursuing graduate education in physics, astronomy, or a related field, at institutions including UCLA, UC Riverside, UC Irvine, UC Santa Barbara, USC, Stanford, Univ. of Arizona, Univ. of Washington, Univ. of Rochester, Michigan State Univ., Georgia Tech, Georgia State Univ., Kent State, Indiana Univ., Univ. of Oregon, Syracuse Univ., Montana State Univ., and the Fisk- Vanderbilt Master’s-to-PhD program. Now in its fourth year, the Cal-Bridge program is a CSU-UC Bridge program comprised of physics and astronomy faculty from 9 University of California (UC), 15 California State University (CSU), and more than 30 California Community College (CCC) campuses throughout California. In the first four years, 34 Cal-Bridge Scholars have been selected, including 22 Hispanic, 3 African-American and 13 women students, 10 of whom are from URM groups. Thirty (30) of the 34 Cal-Bridge Scholars are first generation college students. In the last three years, 17 of 21 Cal-Bridge Scholars have begun or been accepted PhD programs in physics or astronomy at top PhD programs nationally. Three (3) of these scholars have won NSF Graduate Research Fellowships; one more received an Honorable Mention. Once selected, Cal-Bridge Scholars benefit from substantial financial support, intensive, joint mentoring by CSU and UC faculty, professional development workshops, and exposure to research opportunities at the participating UC campuses. Funding for this program is provided by NSF-DUE SSTEM Grant #1356133.

The Tacoma Narrows Bridge Collapse on Film and Video

NASA Astrophysics Data System (ADS)

Olson, Don; Hook, Joseph; Doescher, Russell; Wolf, Steven

2015-11-01

This month marks the 75th anniversary of the Tacoma Narrows Bridge collapse. During a gale on Nov. 7, 1940, the bridge exhibited remarkable oscillations before collapsing spectacularly (Figs. 1-5). Physicists over the years have spent a great deal of time and energy studying this event. By using open-source analysis tools and digitized footage of the disaster, physics students in both high school and college can continue in this tradition. Students can watch footage of "Galloping Gertie," ask scientific questions about the bridge's collapse, analyze data, and draw conclusions from that analysis. Students should be encouraged to pursue their own investigations, but the question that drove our inquiry was this: "When physics classes watch modern video showing the oscillations and the free fall of the bridge fragments, are these scenes sped up, slowed down, or at the correct speed compared to what was observed by the eyewitnesses on Nov. 7, 1940?"

Physical and cognitive capability in mid-adulthood as determinants of retirement and extended working life in a British cohort study.

PubMed

Stafford, Mai; Cooper, Rachel; Cadar, Dorina; Carr, Ewan; Murray, Emily; Richards, Marcus; Stansfeld, Stephen; Zaninotto, Paola; Head, Jenny; Kuh, Diana

2017-01-01

Objective Policy in many industrialized countries increasingly emphasizes extended working life. We examined associations between physical and cognitive capability in mid-adulthood and work in late adulthood. Methods Using self-reported physical limitations and performance-based physical and cognitive capability at age 53, assessed by trained nurses from the Medical Research Council (MRC) National Survey of Health and Development, we examined prospective associations with extended working (captured by age at and reason for retirement from main occupation, bridge employment in paid work after retirement from the main occupation, and voluntary work participation) up to age 68 among >2000 men and women. Results Number of reported physical limitations at age 53 was associated with higher likelihood of retiring for negative reasons and lower likelihood of participating in bridge employment, adjusted for occupational class, education, partner's employment, work disability at age 53, and gender. Better performance on physical and cognitive tests was associated with greater likelihood of participating in bridge or voluntary work. Cognitive capability in the top 10% compared with the middle 80% of the distribution was associated with an odds ratio of bridge employment of 1.71 [95% confidence interval (95% CI) 1.21-2.42]. Conclusions The possibility for an extending working life is less likely to be realized by those with poorer midlife physical or cognitive capability, independently of education, and social class. Interventions to promote capability, starting in mid-adulthood or earlier, could have long-term consequences for extending working.

The "Why" and "Where" of the Tappan Zee Bridge: A Lesson in Site Location, Physical Geography, and Politics

ERIC Educational Resources Information Center

Mitchell, Jerry T.; Cantrill, Jeremy; Kearse, Justin

2012-01-01

Bridges are some of the most majestic features in the American landscape. For classrooms, the bridge serves as an important component of one of the main themes of geography: movement. One bridge, north of Manhattan and crossing the Hudson River, is the Tappan Zee. One aspect that stands out in a way that does not at all appear reasonable: the…

Truck shipments across the Woodrow Wilson Bridge : value and tonnage in 1993

DOT National Transportation Integrated Search

1998-04-01

The Woodrow Wilson Bridge, where Interstate 95 crosses the Potomac River just south of Washington, DC, carries significant amounts of freight to support economic activities well beyond the nation's capitol. The Bureau of Transportation Statistics (BT...

An experimental validation of a statistical-based damage detection approach.

DOT National Transportation Integrated Search

2011-01-01

In this work, a previously-developed, statistical-based, damage-detection approach was validated for its ability to : autonomously detect damage in bridges. The damage-detection approach uses statistical differences in the actual and : predicted beha...

Calibration of LRFR live load factors using weigh-in-motion data.

DOT National Transportation Integrated Search

2006-06-01

The Load and Resistance Factor Rating (LRFR) code for load rating bridges is based on factors calibrated from structural : load and resistance statistics to achieve a more uniform level of reliability for all bridges. The liveload factors in the : LR...

[Difference analysis of muscle fatigue during the exercises of core stability training].

PubMed

Xiao, Jinzhuang; Sun, Jinli; Wang, Hongrui; Yang, Xincai; Zhao, Jinkui

2017-04-01

The present study was carried out with the surface electromyography signal of subjects during the time when subjects did the exercises of the 6 core stability trainings. We analyzed the different activity level of surface electromyography signal, and finally got various fatigue states of muscles in different exercises. Thirty subjects completed exercises of 6 core stability trainings, which were prone bridge, supine bridge, unilateral bridge (divided into two trainings, i.e. the left and right sides alternatively) and bird-dog (divided into two trainings, i.e. the left and right sides alternatively), respectively. Each exercise was held on for 1 minute and 2 minutes were given to relax between two exercises in this test. We measured both left and right sides of the body's muscles, which included erector spina, external oblique, rectus abdominis, rectus femoris, biceps femoris, anterior tibial and gastrocnemius muscles. We adopted the frequency domain characteristic value of the surface electromyography signal, i.e . median frequency slope to analyze the muscle fatigue in this study. In the present paper, the results exhibit different fatigue degrees of the above muscles during the time when they did the core stability rehabilitation exercises. It could be concluded that supine bridge and unilateral bridge can cause more fatigue on erector spina muscle, prone bridge caused Gastrocnemius muscle much fatigue and there were statistical significant differences ( P <0.05) between prone bridge and other five rehabilitation exercises in the degree of rectus abdominis muscle fatigue. There were no statistical significant differences ( P >0.05) between all the left and right sides of the same-named muscles in the median frequency slope during all the exercises of the six core stability trainings, i.e. the degree which the various kinds of rehabilitation exercises effected the left and right side of the same-named muscle had no statistical significant difference ( P >0.05). In this research, the conclusion presents quantized guidelines on the effects of core stability trainings on different muscles.

Protein thermal stability enhancement by designing salt bridges: a combined computational and experimental study.

PubMed

Lee, Chi-Wen; Wang, Hsiu-Jung; Hwang, Jenn-Kang; Tseng, Ching-Ping

2014-01-01

Protein thermal stability is an important factor considered in medical and industrial applications. Many structural characteristics related to protein thermal stability have been elucidated, and increasing salt bridges is considered as one of the most efficient strategies to increase protein thermal stability. However, the accurate simulation of salt bridges remains difficult. In this study, a novel method for salt-bridge design was proposed based on the statistical analysis of 10,556 surface salt bridges on 6,493 X-ray protein structures. These salt bridges were first categorized based on pairing residues, secondary structure locations, and Cα-Cα distances. Pairing preferences generalized from statistical analysis were used to construct a salt-bridge pair index and utilized in a weighted electrostatic attraction model to find the effective pairings for designing salt bridges. The model was also coupled with B-factor, weighted contact number, relative solvent accessibility, and conservation prescreening to determine the residues appropriate for the thermal adaptive design of salt bridges. According to our method, eight putative salt-bridges were designed on a mesophilic β-glucosidase and 24 variants were constructed to verify the predictions. Six putative salt-bridges leaded to the increase of the enzyme thermal stability. A significant increase in melting temperature of 8.8, 4.8, 3.7, 1.3, 1.2, and 0.7°C of the putative salt-bridges N437K-D49, E96R-D28, E96K-D28, S440K-E70, T231K-D388, and Q277E-D282 was detected, respectively. Reversing the polarity of T231K-D388 to T231D-D388K resulted in a further increase in melting temperatures by 3.6°C, which may be caused by the transformation of an intra-subunit electrostatic interaction into an inter-subunit one depending on the local environment. The combination of the thermostable variants (N437K, E96R, T231D and D388K) generated a melting temperature increase of 15.7°C. Thus, this study demonstrated a novel method for the thermal adaptive design of salt bridges through inference of suitable positions and substitutions.

Introducing the refined gravity hypothesis of extreme sexual size dimorphism

PubMed Central

2010-01-01

Background Explanations for the evolution of female-biased, extreme Sexual Size Dimorphism (SSD), which has puzzled researchers since Darwin, are still controversial. Here we propose an extension of the Gravity Hypothesis (i.e., the GH, which postulates a climbing advantage for small males) that in conjunction with the fecundity hypothesis appears to have the most general power to explain the evolution of SSD in spiders so far. In this "Bridging GH" we propose that bridging locomotion (i.e., walking upside-down under own-made silk bridges) may be behind the evolution of extreme SSD. A biomechanical model shows that there is a physical constraint for large spiders to bridge. This should lead to a trade-off between other traits and dispersal in which bridging would favor smaller sizes and other selective forces (e.g. fecundity selection in females) would favor larger sizes. If bridging allows faster dispersal, small males would have a selective advantage by enjoying more mating opportunities. We predicted that both large males and females would show a lower propensity to bridge, and that SSD would be negatively correlated with sexual dimorphism in bridging propensity. To test these hypotheses we experimentally induced bridging in males and females of 13 species of spiders belonging to the two clades in which bridging locomotion has evolved independently and in which most of the cases of extreme SSD in spiders are found. Results We found that 1) as the degree of SSD increased and females became larger, females tended to bridge less relative to males, and that 2) smaller males and females show a higher propensity to bridge. Conclusions Physical constraints make bridging inefficient for large spiders. Thus, in species where bridging is a very common mode of locomotion, small males, by being more efficient at bridging, will be competitively superior and enjoy more mating opportunities. This "Bridging GH" helps to solve the controversial question of what keeps males small and also contributes to explain the wide range of SSD in spiders, as those spider species in which extreme SSD has not evolved but still live in tall vegetation, do not use bridging locomotion to disperse. PMID:20682029

Skewed highway bridges.

DOT National Transportation Integrated Search

2013-07-01

Many highway bridges are skewed and their behavior and corresponding design analysis need to be furthered to fully accomplish design objectives. This project used physical-test and detailed finite element analysis to better understand the behavior of...

Mapping cognitive structures of community college students engaged in basic electrostatics laboratories

NASA Astrophysics Data System (ADS)

Haggerty, Dennis Charles

Community college students need to be abstract thinkers in order to be successful in the introductory Physics curriculum. The purpose of this dissertation is to map the abstract thinking of community college Physics students. The laboratory environment was used as a vehicle for the mapping. Three laboratory experiments were encountered. One laboratory was based on the classic Piagetian task, the centripetal motion (CM) problem. The other two laboratories were introductory electrostatic Physics experiments, Resistance (RES) and Capacitance (CAP). The students performed all laboratories using the thinking-aloud technique. The researcher collected their verbal protocols using audiotapes. The audiotaped data was quantified by comparing it to a scoring matrix based on the Piagetian logical operators (Inhelder & Piaget, 1958) for abstract thinking. The students received scores for each laboratory experiment. These scores were compared to a reliable test of intellectual functioning, the Shipley Institute of Living Scale (SILS). Spearman rank correlation coefficients (SRCC) were obtained for SILS versus CM; SILS versus RES; and SILS versus CAP. Statistically significant results were obtained for SILS versus CM and SILS versus RES at the p < 0.05 level. When an outlier to the data was considered and suppressed, the SILS versus CAP was also statistically significant at the p < 0.05 level. The scoring matrix permits a bridge from the qualitative Piagetian level of cognitive development to a quantified, mapped level of cognitive development. The ability to quantify student abstract thinking in Physics education provides a means to adjust an instructional approach. This approach could lead to a proper state of Physics education.

California State University Long Beach: Model for a Terminal Master's Program as a Bridge to PhD

NASA Astrophysics Data System (ADS)

Bill, Andreas; Kenealy, Patrick; Kwon, Chuhee; Papp, Zoltan; Pickett, Galen T.

The department of Physics & Astronomy at California State University Long Beach has redesigned its Master's program in 2008 with the goal to provide a true graduate experience in Physics. The hallmarks of the program are five core graduate courses and a research-based MS thesis. During the last five years, 42% of MS recipients (24 students) were accepted to PhD programs, 41% started private-sector STEM careers, and 17% decided on teaching and other paths. The program doubled in size during that period. In 2013 we also became one of six Bridge Sites and only non-PhD granting institution of the American Physical Society (APS). We will describe the structure of the MS program, its goals and its place in the University degree plan landscape. We will also discuss how the APS Bridge Program has been implemented in our institution and has influenced our MS program. We gratefully acknowledge support from a variety of sources that contributed to establish the MS program, including the APS Bridge Program, individual NSF and Army Research Laboratory Grants.

PREFACE: Advanced many-body and statistical methods in mesoscopic systems

NASA Astrophysics Data System (ADS)

Anghel, Dragos Victor; Sabin Delion, Doru; Sorin Paraoanu, Gheorghe

2012-02-01

It has increasingly been realized in recent times that the borders separating various subfields of physics are largely artificial. This is the case for nanoscale physics, physics of lower-dimensional systems and nuclear physics, where the advanced techniques of many-body theory developed in recent times could provide a unifying framework for these disciplines under the general name of mesoscopic physics. Other fields, such as quantum optics and quantum information, are increasingly using related methods. The 6-day conference 'Advanced many-body and statistical methods in mesoscopic systems' that took place in Constanta, Romania, between 27 June and 2 July 2011 was, we believe, a successful attempt at bridging an impressive list of topical research areas: foundations of quantum physics, equilibrium and non-equilibrium quantum statistics/fractional statistics, quantum transport, phases and phase transitions in mesoscopic systems/superfluidity and superconductivity, quantum electromechanical systems, quantum dissipation, dephasing, noise and decoherence, quantum information, spin systems and their dynamics, fundamental symmetries in mesoscopic systems, phase transitions, exactly solvable methods for mesoscopic systems, various extension of the random phase approximation, open quantum systems, clustering, decay and fission modes and systematic versus random behaviour of nuclear spectra. This event brought together participants from seventeen countries and five continents. Each of the participants brought considerable expertise in his/her field of research and, at the same time, was exposed to the newest results and methods coming from the other, seemingly remote, disciplines. The talks touched on subjects that are at the forefront of topical research areas and we hope that the resulting cross-fertilization of ideas will lead to new, interesting results from which everybody will benefit. We are grateful for the financial and organizational support from IFIN-HH, Ovidius University (where the conference took place), the Academy of Romanian Scientists and the Romanian National Authority for Scientific Research. This conference proceedings volume brings together some of the invited and contributed talks of the conference. The hope of the editors is that they will constitute reference material for applying many-body techniques to problems in mesoscopic and nuclear physics. We thank all the participants for their contribution to the success of this conference. D V Anghel and D S Delion IFIN-HH, Bucharest, Romania G S Paraoanu Aalto University, Finland Conference photograph

The Fisk-Vanderbilt Masters-to-PhD Bridge Program: A Model for Broadening Participation of Underrepresented Groups in the Physical Sciences through Effective Partnerships with Minority-Serving Institutions

ERIC Educational Resources Information Center

Stassun, Keivan Guadalupe; Burger, Arnold; Lange, Sheila Edwards

2010-01-01

We describe the Fisk-Vanderbilt Masters-to-PhD Bridge program as a successful model for effective partnerships with minority-serving institutions toward significantly broadening the participation of underrepresented groups in the physical sciences. The program couples targeted recruitment with active retention strategies, and is built upon a…

Encouraging Conceptual Change: The Use of Bridging Analogies in the Teaching of Action-Reaction Forces and the "At Rest" Condition in Physics. Research Report

ERIC Educational Resources Information Center

Bryce, Tom; MacMillan, Kenneth

2005-01-01

The qualitative study described in this paper examined the effectiveness of bridging analogies intended to bring about conceptual change as part of a constructivist approach to teaching about action-reaction forces in the 'at rest' condition in physics. Twenty-one 15-year-old students were involved in the investigation with subgroups previously…

Assessment of bridge abutment scour and sediment transport under various flow conditions

NASA Astrophysics Data System (ADS)

Gilja, Gordon; Valyrakis, Manousos; Michalis, Panagiotis; Bekić, Damir; Kuspilić, Neven; McKeogh, Eamon

2017-04-01

Safety of bridges over watercourses can be compromised by flow characteristics and bridge hydraulics. Scour process around bridge foundations can develop rapidly during low-recurrence interval floods when structural elements are exposed to increased flows. Variations in riverbed geometry, as a result of sediment removal and deposition processes, can increase flood-induced hazard at bridge sites with catastrophic failures and destructive consequences for civil infrastructure. The quantification of flood induced hazard on bridge safety generally involves coupled hydrodynamic and sediment transport models (i.e. 2D numerical or physical models) for a range of hydrological events covering both high and low flows. Modelled boundary conditions are usually estimated for their probability of occurrence using frequency analysis of long-term recordings at gauging stations. At smaller rivers gauging station records are scarce, especially in upper courses of rivers where weirs, drops and rapids are common elements of river bathymetry. As a result, boundary conditions that accurately represent flow patterns on modelled river reach cannot be often reliably acquired. Sediment transport process is also more complicated to describe due to its complexity and dependence to local flow field making scour hazard assessment a particularly challenging issue. This study investigates the influence of flow characteristics to the development of scour and sedimentation processes around bridge abutments of a single span masonry arch bridge in south Ireland. The impact of downstream weirs on bridge hydraulics through variation of downstream model domain type is also considered in this study. The numerical model is established based on detailed bathymetry data surveyed along a rectangular grid of 50cm spacing. Acquired data also consist of riverbed morphology and water level variations which are monitored continuously on bridge site. The obtained data are then used to compare and calibrate numerical models for several flood scenarios. The determination of the boundary conditions is followed by physical modelling to investigate the development of scour around bridge elements. The comparison of surveyed data with the obtained numerical and physical modelling results provide an insight of various flow patterns and their influence on riverbed morphology. This can deliver important information needed for assessment of structural risk associated with flood events. Acknowledgement: The authors wish to acknowledge the financial support of the European Commission, through the Marie Curie action Industry-Academia Partnership and Pathways Network BRIDGE SMS (Intelligent Bridge Assessment Maintenance and Management System) - FP7-People-2013-IAPP- 612517.

Measurements of Surfactant Squeeze-out Using Magnetically-Levitated Liquid Bridges

NASA Technical Reports Server (NTRS)

Rosenblatt, Charles

2004-01-01

Liquid bridges: Columns of liquid supported by two solid surfaces. These are generally opposing right circular cylinders in 0g. For a cylindrical bridge of length L and diameter d, in zero g, the maximum slenderness ratio Lambda [L/d] = pi [Rayleigh]. In the presence of gravity the cylindrical shape of an axisymmetric bridge tends to deform. Fluid has a volumetric magnetic susceptibility X. Magnetic levitation has numerous applications in studies of fluids, "soft" and "hard" condensed matter physics, and biophysics

A Model to predict the impact of specification changes on the chloride-induced service life of Virginia bridge decks.

DOT National Transportation Integrated Search

2002-01-01

A model to determine the time to first repair and subsequent rehabilitation of concrete bridge decks exposed to chloride deicer salts that recognizes and incorporates the statistical nature of factors affecting the corrosion process is developed. The...

Vulnerability of United States Bridges to Potential Increases in Flooding from Climate Change

EPA Science Inventory

This study assesses the potential impacts of increased river flooding from climate change on bridges in the continental United States. Daily precipitation statistics from four climate models and three greenhouse gas (GHG) emissions scenarios (A2, A1B, and B1) are used to capture ...

Record statistics of a strongly correlated time series: random walks and Lévy flights

NASA Astrophysics Data System (ADS)

Godrèche, Claude; Majumdar, Satya N.; Schehr, Grégory

2017-08-01

We review recent advances on the record statistics of strongly correlated time series, whose entries denote the positions of a random walk or a Lévy flight on a line. After a brief survey of the theory of records for independent and identically distributed random variables, we focus on random walks. During the last few years, it was indeed realized that random walks are a very useful ‘laboratory’ to test the effects of correlations on the record statistics. We start with the simple one-dimensional random walk with symmetric jumps (both continuous and discrete) and discuss in detail the statistics of the number of records, as well as of the ages of the records, i.e. the lapses of time between two successive record breaking events. Then we review the results that were obtained for a wide variety of random walk models, including random walks with a linear drift, continuous time random walks, constrained random walks (like the random walk bridge) and the case of multiple independent random walkers. Finally, we discuss further observables related to records, like the record increments, as well as some questions raised by physical applications of record statistics, like the effects of measurement error and noise.

A bridge from physics to biology.

PubMed

Preparata, Giuliano

2010-01-01

Through molecular biology, the 'atomistic paradigm' tries to remove from the analysis of living matter every element of what appears as the distinguishing character of the chain of the biological processes: their cooperative, collective aspects. Living matter appears, on the contrary, governed by Quantum Field Theory (QFT), spontaneously creating order when the thermodynamical conditions are right. 'Electrodynamical coherence' (EC) is the most promising hint for the existence of a bridge between Physics and Biology.

Mechanical reinforcement and segmental dynamics of polymer nanocomposites

NASA Astrophysics Data System (ADS)

Gong, Shushan

The addition of nanofiller into a polymer matrix will dramatically change the physical properties of polymer. The introduction of nanofiller makes the polymer more applicable in many industries, such as automobile tires, coatings, semiconductors, and packaging. The altered properties are not the simple combination of the characters from the two components. The interactions in polymer nanocomposites play an important role in determining the physical properties. This dissertation focuses on the mechanical properties of polymer nanocomposites (silica/poly-2-vinylpyridine) above their glass transition temperature Tg, as a model for automobile tires, which utilize small silica particles in crosslinked rubber far above Tg. We also investigate the impacts of the interaction between particle filler and polymer matrix on the altered mechanical properties. Dielectric relaxation spectroscopy (DRS) is used to study the glassy bound polymer layers formed around the particles. The results show evidence of the existence of immobilized polymer layers at the surface of each nanoparticle. At the same time, the thickness of the immobilized polymer layers is quantified and formed to be around 2 nm. Then we consider particles with glassy bound polymer layers are bridged together (either rubbery bridge or glassy bridge) by polymer chains and form small clusters. Clusters finally percolate to form a particle-polymer network as loading fraction increases. Rheology is used to study the network formation, and to predict the boundary of rubbery bridge and glassy bridge regimes. The distance between particles determines the type of polymer bridging. The particle spacing larger than Kuhn length makes flexible (rubbery) bridge with rheology described by a flexible Rouse model for percolation. When the spacing is shorter than the Kuhn length (~ 1nm), stiffer bridge forms instead, which is called glassy bridge. The mechanical differences between rubbery bridge and glassy bridge, and the effect of Mw on the formation of glassy bridge, are also discussed.

Documentation of bridge condition using QuickTime Virtual Reality.

DOT National Transportation Integrated Search

2006-07-01

In bridge inspection, the condition rating assigned to a structural component represents the outcome of a subjective comparison of the members current physical condition to its as-built condition. This evaluation is made with the aid of the ...

2004 status of the nation's highways, bridges, and transit : conditions & performance : report to Congress

DOT National Transportation Integrated Search

2004-01-01

This document is intended to provide Congress and other decision makers with an objective appraisal of the physical conditions, operational performance, financing mechanisms, and future investment requirements of highways, bridges, and transit system...

Exploring Explanations of Subglacial Bedform Sizes Using Statistical Models.

PubMed

Hillier, John K; Kougioumtzoglou, Ioannis A; Stokes, Chris R; Smith, Michael J; Clark, Chris D; Spagnolo, Matteo S

2016-01-01

Sediments beneath modern ice sheets exert a key control on their flow, but are largely inaccessible except through geophysics or boreholes. In contrast, palaeo-ice sheet beds are accessible, and typically characterised by numerous bedforms. However, the interaction between bedforms and ice flow is poorly constrained and it is not clear how bedform sizes might reflect ice flow conditions. To better understand this link we present a first exploration of a variety of statistical models to explain the size distribution of some common subglacial bedforms (i.e., drumlins, ribbed moraine, MSGL). By considering a range of models, constructed to reflect key aspects of the physical processes, it is possible to infer that the size distributions are most effectively explained when the dynamics of ice-water-sediment interaction associated with bedform growth is fundamentally random. A 'stochastic instability' (SI) model, which integrates random bedform growth and shrinking through time with exponential growth, is preferred and is consistent with other observations of palaeo-bedforms and geophysical surveys of active ice sheets. Furthermore, we give a proof-of-concept demonstration that our statistical approach can bridge the gap between geomorphological observations and physical models, directly linking measurable size-frequency parameters to properties of ice sheet flow (e.g., ice velocity). Moreover, statistically developing existing models as proposed allows quantitative predictions to be made about sizes, making the models testable; a first illustration of this is given for a hypothesised repeat geophysical survey of bedforms under active ice. Thus, we further demonstrate the potential of size-frequency distributions of subglacial bedforms to assist the elucidation of subglacial processes and better constrain ice sheet models.

The bridging conformations of double-end anchored polymer-surfactants destabilize a hydrogel of lipid membranes

NASA Astrophysics Data System (ADS)

Slack, N. L.; Davidson, P.; Chibbaro, M. A.; Jeppesen, C.; Eiselt, P.; Warriner, H. E.; Schmidt, H.-W.; Pincus, P.; Safinya, C. R.

2001-10-01

Double-end-anchored poly-ethylene-glycol-surfactants (DEA-PEG-surfactants) induce the gelation of lyotropic lamellar Lα phases stabilized by undulation forces. The physical hydrogel (Lα,g) derives its viscoelasticity from the proliferation of defects at a mesoscopic level. The DEA-PEG-surfactants assume both looping and bridging conformations. The existence of novel bridging conformations is indicated by the coexistence of two lamellar phases and the limited swelling of the Lα and Lα,g phases. Modeling of the polymer decorated membranes demonstrates the existence of bridging and yields a rapidly decreasing density of bridging conformations with increasing interlayer spacing.

Implementing statistical analysis in multi-channel acoustic impact-echo testing of concrete bridge decks: Determining thresholds for delamination detection

NASA Astrophysics Data System (ADS)

Hendricks, Lorin; Spencer Guthrie, W.; Mazzeo, Brian

2018-04-01

An automated acoustic impact-echo testing device with seven channels has been developed for faster surveying of bridge decks. Due to potential variations in bridge deck overlay thickness, varying conditions between testing passes, and occasional imprecise equipment calibrations, a method that can account for variations in deck properties and testing conditions was necessary to correctly interpret the acoustic data. A new methodology involving statistical analyses was therefore developed. After acoustic impact-echo data are collected and analyzed, the results are normalized by the median for each channel, a Gaussian distribution is fit to the histogram of the data, and the Kullback-Leibler divergence test or Otsu's method is then used to determine the optimum threshold for differentiating between intact and delaminated concrete. The new methodology was successfully applied to individual channels of previously unusable acoustic impact-echo data obtained from a three-lane interstate bridge deck surfaced with a polymer overlay, and the resulting delamination map compared very favorably with the results of a manual deck sounding survey.

A Statistical Physicist's Approach to Biological Motion: From the the Kinesin Walk to Muscle Contraction

NASA Astrophysics Data System (ADS)

Vicsek, Tamas

1997-03-01

It is demonstrated that a wide range of experimental results on biological motion can be successfully interpreted in terms of statistical physics motivated models taking into account the relevant microscopic details of motor proteins and allowing analytic solutions. Two important examples are considered, i) the motion of a single kinesin molecule along microtubules inside individual cells and ii) muscle contraction which is a macroscopic phenomenon due to the collective action of a large number of myosin heads along actin filaments. i) Recently individual two-headed kinesin molecules have been studied in in vitro motility assays revealing a number of their peculiar transport properties. Here we propose a simple and robust model for the kinesin stepping process with elastically coupled Brownian heads showing all of these properties. The analytic treatment of our model results in a very good fit to the experimental data and practically has no free parameters. ii) Myosin is an ATPase enzyme that converts the chemical energy stored in ATP molecules into mechanical work. During muscle contraction, the myosin cross-bridges attach to the actin filaments and exert force on them yielding a relative sliding of the actin and myosin filaments. In this paper we present a simple mechanochemical model for the cross-bridge interaction involving the relevant kinetic data and providing simple analytic solutions for the mechanical properties of muscle contraction, such as the force-velocity relationship or the relative number of the attached cross-bridges. So far the only analytic formula which could be fitted to the measured force-velocity curves has been the well known Hill equation containing parameters lacking clear microscopic origin. The main advantages of our new approach are that it explicitly connects the mechanical data with the kinetic data and the concentration of the ATP and ATPase products and as such it leads to new analytic solutions which agree extremely well with a wide range of experimental curves, while the parameters of the corresponding expressions have well defined microscopic meaning.

Polymer concrete overlay on SH-51, bridge deck

NASA Astrophysics Data System (ADS)

Borg, T. M.

1982-06-01

A thin resinous overlay was placed on a sound bridge deck in Oklahoma to evaluate its performance over one year using various physical tests. The evaluation shows how well the overlay protects the reinforcing steel from corrosion due to deicing salts. The steps leading to the construction of the overlay are detailed as well as the actual placing of the overlay. The results of various physical tests are reported for both before and after the overlay.

Mesoscale Computational Investigation of Shocked Heterogeneous Materials with Application to Large Impact Craters

NASA Technical Reports Server (NTRS)

Crawford, D. A.; Barnouin-Jha, O. S.; Cintala, M. J.

2003-01-01

The propagation of shock waves through target materials is strongly influenced by the presence of small-scale structure, fractures, physical and chemical heterogeneities. Pre-existing fractures often create craters that appear square in outline (e.g. Meteor Crater). Reverberations behind the shock from the presence of physical heterogeneity have been proposed as a mechanism for transient weakening of target materials. Pre-existing fractures can also affect melt generation. In this study, we are attempting to bridge the gap in numerical modeling between the micro-scale and the continuum, the so-called meso-scale. To accomplish this, we are developing a methodology to be used in the shock physics hydrocode (CTH) using Monte-Carlo-type methods to investigate the shock properties of heterogeneous materials. By comparing the results of numerical experiments at the micro-scale with experimental results and by using statistical techniques to evaluate the performance of simple constitutive models, we hope to embed the effect of physical heterogeneity into the field variables (pressure, stress, density, velocity) allowing us to directly imprint the effects of micro-scale heterogeneity at the continuum level without incurring high computational cost.

The prone bridge test: Performance, validity, and reliability among older and younger adults.

PubMed

Bohannon, Richard W; Steffl, Michal; Glenney, Susan S; Green, Michelle; Cashwell, Leah; Prajerova, Kveta; Bunn, Jennifer

2018-04-01

The prone bridge maneuver, or plank, has been viewed as a potential alternative to curl-ups for assessing trunk muscle performance. The purpose of this study was to assess prone bridge test performance, validity, and reliability among younger and older adults. Sixty younger (20-35 years old) and 60 older (60-79 years old) participants completed this study. Groups were evenly divided by sex. Participants completed surveys regarding physical activity and abdominal exercise participation. Height, weight, body mass index (BMI), and waist circumference were measured. On two occasions, 5-9 days apart, participants held a prone bridge until volitional exhaustion or until repeated technique failure. Validity was examined using data from the first session: convergent validity by calculating correlations between survey responses, anthropometrics, and prone bridge time, known groups validity by using an ANOVA comparing bridge times of younger and older adults and of men and women. Test-retest reliability was examined by using a paired t-test to compare prone bridge times for Session1 and Session 2. Furthermore, an intraclass correlation coefficient (ICC) was used to characterize relative reliability and minimal detectable change (MDC 95% ) was used to describe absolute reliability. The mean prone bridge time was 145.3 ± 71.5 s, and was positively correlated with physical activity participation (p ≤ 0.001) and negatively correlated with BMI and waist circumference (p ≤ 0.003). Younger participants had significantly longer plank times than older participants (p = 0.003). The ICC between testing sessions was 0.915. The prone bridge test is a valid and reliable measure for evaluating abdominal performance in both younger and older adults. Copyright © 2017 Elsevier Ltd. All rights reserved.

The core symptoms of bulimia nervosa, anxiety, and depression: A network analysis.

PubMed

Levinson, Cheri A; Zerwas, Stephanie; Calebs, Benjamin; Forbush, Kelsie; Kordy, Hans; Watson, Hunna; Hofmeier, Sara; Levine, Michele; Crosby, Ross D; Peat, Christine; Runfola, Cristin D; Zimmer, Benjamin; Moesner, Markus; Marcus, Marsha D; Bulik, Cynthia M

2017-04-01

Bulimia nervosa (BN) is characterized by symptoms of binge eating and compensatory behavior, and overevaluation of weight and shape, which often co-occur with symptoms of anxiety and depression. However, there is little research identifying which specific BN symptoms maintain BN psychopathology and how they are associated with symptoms of depression and anxiety. Network analyses represent an emerging method in psychopathology research to examine how symptoms interact and may become self-reinforcing. In the current study of adults with a Diagnostic and Statistical Manual for Mental Disorders-Fourth Edition ( DSM-IV ) diagnosis of BN (N = 196), we used network analysis to identify the central symptoms of BN, as well as symptoms that may bridge the association between BN symptoms and anxiety and depression symptoms. Results showed that fear of weight gain was central to BN psychopathology, whereas binge eating, purging, and restriction were less central in the symptom network. Symptoms related to sensitivity to physical sensations (e.g., changes in appetite, feeling dizzy, and wobbly) were identified as bridge symptoms between BN, and anxiety and depressive symptoms. We discuss our findings with respect to cognitive-behavioral treatment approaches for BN. These findings suggest that treatments for BN should focus on fear of weight gain, perhaps through exposure therapies. Further, interventions focusing on exposure to physical sensations may also address BN psychopathology, as well as co-occurring anxiety and depressive symptoms. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

2008 status of the nation's highways, bridges, and transit : conditions & performance : report to Congress

DOT National Transportation Integrated Search

2008-01-01

This document is intended to provide decision makers with an objective appraisal of the physical conditions, operational performances, and financing mechanisms of highways, bridges, and transit systems based both on the current state of these systems...

2006 status of the nation's highways, bridges, and transit : conditions & performance : report to Congress

DOT National Transportation Integrated Search

2006-01-01

This document is intended to provide decision makers with an objective appraisal of the physical conditions, operational performance, and financing mechanisms of highways, bridges, and transit systems based both on the current state of these systems ...

Research of diagnosis sensors fault based on correlation analysis of the bridge structural health monitoring system

NASA Astrophysics Data System (ADS)

Hu, Shunren; Chen, Weimin; Liu, Lin; Gao, Xiaoxia

2010-03-01

Bridge structural health monitoring system is a typical multi-sensor measurement system due to the multi-parameters of bridge structure collected from the monitoring sites on the river-spanning bridges. Bridge structure monitored by multi-sensors is an entity, when subjected to external action; there will be different performances to different bridge structure parameters. Therefore, the data acquired by each sensor should exist countless correlation relation. However, complexity of the correlation relation is decided by complexity of bridge structure. Traditionally correlation analysis among monitoring sites is mainly considered from physical locations. unfortunately, this method is so simple that it cannot describe the correlation in detail. The paper analyzes the correlation among the bridge monitoring sites according to the bridge structural data, defines the correlation of bridge monitoring sites and describes its several forms, then integrating the correlative theory of data mining and signal system to establish the correlation model to describe the correlation among the bridge monitoring sites quantificationally. Finally, The Chongqing Mashangxi Yangtze river bridge health measurement system is regards as research object to diagnosis sensors fault, and simulation results verify the effectiveness of the designed method and theoretical discussions.

Statistical quasi-particle theory for open quantum systems

NASA Astrophysics Data System (ADS)

Zhang, Hou-Dao; Xu, Rui-Xue; Zheng, Xiao; Yan, YiJing

2018-04-01

This paper presents a comprehensive account on the recently developed dissipaton-equation-of-motion (DEOM) theory. This is a statistical quasi-particle theory for quantum dissipative dynamics. It accurately describes the influence of bulk environments, with a few number of quasi-particles, the dissipatons. The novel dissipaton algebra is then followed, which readily bridges the Schrödinger equation to the DEOM theory. As a fundamental theory of quantum mechanics in open systems, DEOM characterizes both the stationary and dynamic properties of system-and-bath interferences. It treats not only the quantum dissipative systems of primary interest, but also the hybrid environment dynamics that could be experimentally measurable. Examples are the linear or nonlinear Fano interferences and the Herzberg-Teller vibronic couplings in optical spectroscopies. This review covers the DEOM construction, the underlying dissipaton algebra and theorems, the physical meanings of dynamical variables, the possible identifications of dissipatons, and some recent advancements in efficient DEOM evaluations on various problems. The relations of the present theory to other nonperturbative methods are also critically presented.

Comparison of a Physical and Numerical Mobile-Bed Model of Beach and T-Head Groin Interaction

DTIC Science & Technology

2011-05-01

Hydraulic Centre’s Large Area Basin (LAB), utilizing a set of moveable wave generators capable of providing long-crested waves to match a variety...was conducted manually from a bridge as shown in Figure 4. The location of the transect (Profile 2) is shown in Figure 2. Planform morphology was...4. Physical model oblique view showing profile measurement location and bridge . 2617 The T-head groins and the shore-normal breakwater trunk at the

Set statistics in conductive bridge random access memory device with Cu/HfO{sub 2}/Pt structure

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

Zhang, Meiyun; Long, Shibing, E-mail: longshibing@ime.ac.cn; Wang, Guoming

2014-11-10

The switching parameter variation of resistive switching memory is one of the most important challenges in its application. In this letter, we have studied the set statistics of conductive bridge random access memory with a Cu/HfO{sub 2}/Pt structure. The experimental distributions of the set parameters in several off resistance ranges are shown to nicely fit a Weibull model. The Weibull slopes of the set voltage and current increase and decrease logarithmically with off resistance, respectively. This experimental behavior is perfectly captured by a Monte Carlo simulator based on the cell-based set voltage statistics model and the Quantum Point Contact electronmore » transport model. Our work provides indications for the improvement of the switching uniformity.« less

Atomtronics: Material and Device Physics of Quantum Gases

DTIC Science & Technology

matter physics to electrical engineering. Our projects title Atomtronics: Material and device physics of quantum gases illustrates the chasm we bridged...starting from therich and fundamental physics already revealed with cold atoms systems, then leading to an understanding of the functional materials

Bridging the Cultural Gap: Ten Steps toward a More Multicultural Youth Library.

ERIC Educational Resources Information Center

Agosto, Denise E.

2001-01-01

Presents ten steps toward a more multicultural youth library to help bridge cultural and linguistic gaps in public and school libraries. Topics include mission statements; physical environment; collection diversity; collaboration; bilingual materials; multicultural materials; community involvement; and appreciating diversity. (LRW)

Stability Limits and Dynamics of Nonaxisymmetric Liquid Bridges

NASA Technical Reports Server (NTRS)

Alexander, J. Iwan D.; Slobozhanin, Lev A.; Resnick, Andrew H.; Ramus, Jean-Francois; Delafontaine, Sylvie

1999-01-01

Liquid bridges have been the focus of numerous theoretical and experimental investigations since the early work by Plateau more than a century ago. More recently, motivated by interest in their physical behavior and their occurrence in a variety of technological situations, there has been a resurgence of interest in the static and dynamic behavior of liquid bridges. Furthermore, opportunities to carry out experiments in the near weightless environment of a low-Earth-orbit spacecraft have also led to a number of low-gravity experiments involving large liquid bridges. In this paper, we present selected results from our work concerning the stability of nonaxisymmetric liquid bridges, the bifurcation of weightless bridges in the neighborhood of the maximum volume stability limit, isorotating axisymmetric bridges contained between equidimensional disks, and bridges contained between unequal disks. For the latter, we discuss both theoretical and experimental results. Finally, we present results concerning the stability of axisymmetric equilibrium configurations for a capillary liquid partly contained in a closed circular cylinder.

Pilot project - demonstration of capabilities and benefits of bridge load rating through physical testing : tech transfer summary.

DOT National Transportation Integrated Search

2013-08-01

This project demonstrated the capabilities for load testing bridges in Iowa, developed and presented a webinar to local and state engineers, and produced a spreadsheet and benefit evaluation matrix that others can use to preliminarily assess where br...

A Multicontextual Model of Counseling: Bridging Brevity and Diversity.

ERIC Educational Resources Information Center

Steenbarger, Brett N.

1993-01-01

Comparison and contrast of brief therapy and multicultural counseling highlighting the tension created by their different developmental assumptions. An integrative, multicontextual model of counseling that bridges this gap by intervening at the interface between individuals and their physical, social, and cultural contexts is outlined. (Author/SR)

Modal Parameter Identification and Numerical Simulation for Self-anchored Suspension Bridges Based on Ambient Vibration

NASA Astrophysics Data System (ADS)

Liu, Bing; Sun, Li Guo

2018-06-01

This paper chooses the Nanjing-Hangzhou high speed overbridge, a self-anchored suspension bridge, as the research target, trying to identify the dynamic characteristic parameters of the bridge by using the peak-picking method to analyze the velocity response data under ambient excitation collected by 7 vibration pickup sensors set on the bridge deck. The ABAQUS is used to set up a three-dimensional finite element model for the full bridge and amends the finite element model of the suspension bridge based on the identified modal parameter, and suspender force picked by the PDV100 laser vibrometer. The study shows that the modal parameter can well be identified by analyzing the bridge vibration velocity collected by 7 survey points. The identified modal parameter and measured suspender force can be used as the basis of the amendment of the finite element model of the suspension bridge. The amended model can truthfully reflect the structural physical features and it can also be the benchmark model for the long-term health monitoring and condition assessment of the bridge.

Bridging the Gulf between Formal Calculus and Physical Reasoning.

ERIC Educational Resources Information Center

Van Der Meer, A.

1980-01-01

Some ways to link calculus instruction with the mathematical models used in physics courses are presented. The activity of modelling is presented as a major tool in synchronizing physics and mathematics instruction in undergraduate engineering programs. (MP)

Exploring Explanations of Subglacial Bedform Sizes Using Statistical Models

PubMed Central

Kougioumtzoglou, Ioannis A.; Stokes, Chris R.; Smith, Michael J.; Clark, Chris D.; Spagnolo, Matteo S.

2016-01-01

Sediments beneath modern ice sheets exert a key control on their flow, but are largely inaccessible except through geophysics or boreholes. In contrast, palaeo-ice sheet beds are accessible, and typically characterised by numerous bedforms. However, the interaction between bedforms and ice flow is poorly constrained and it is not clear how bedform sizes might reflect ice flow conditions. To better understand this link we present a first exploration of a variety of statistical models to explain the size distribution of some common subglacial bedforms (i.e., drumlins, ribbed moraine, MSGL). By considering a range of models, constructed to reflect key aspects of the physical processes, it is possible to infer that the size distributions are most effectively explained when the dynamics of ice-water-sediment interaction associated with bedform growth is fundamentally random. A ‘stochastic instability’ (SI) model, which integrates random bedform growth and shrinking through time with exponential growth, is preferred and is consistent with other observations of palaeo-bedforms and geophysical surveys of active ice sheets. Furthermore, we give a proof-of-concept demonstration that our statistical approach can bridge the gap between geomorphological observations and physical models, directly linking measurable size-frequency parameters to properties of ice sheet flow (e.g., ice velocity). Moreover, statistically developing existing models as proposed allows quantitative predictions to be made about sizes, making the models testable; a first illustration of this is given for a hypothesised repeat geophysical survey of bedforms under active ice. Thus, we further demonstrate the potential of size-frequency distributions of subglacial bedforms to assist the elucidation of subglacial processes and better constrain ice sheet models. PMID:27458921

A 12-year National Study of Suicide by Jumping From Bridges in Norway.

PubMed

Sæheim, Aleksandra; Hestetun, Ingebjørg; Mork, Erlend; Nrugham, Latha; Mehlum, Lars

2017-01-01

Studies from several countries suggest that erecting fences on bridges more commonly used for suicide by jumping may be an effective way of reducing the risk of suicide by jumping from these bridges. Distribution of suicides by jumping off bridges has not yet been studied on a national level in any country. This study included all suicides by jumping from high places registered in the Norwegian Cause of Death Registry (COD) in the period 1999-2010 (n = 319). Combining data from the COD registry and information from police records, 71 cases of suicide by jumping off a bridge were identified involving 36 bridges. This form of suicide constituted approximately 1% of all suicides in Norway in the period 1999-2010. Almost half of these suicides were registered at only 6 bridges. Three Norwegian bridges were secured during the observation period of this study. Two bridges had barriers installed on the full length of the bridge with 11 suicides registered before barriers were installed, and none after. On the 1 bridge that was only partially secured, no change in numbers of suicides was observed after barriers were installed. One-third of jumps from bridges occurred over land. We found that although suicide by jumping off bridges was a relatively rare event, there is a potential for saving lives by installing physical barriers on bridges that are more commonly used for suicide by jumping.

Two Successful Variations of Motivational Contests: Bridges and "Whizzers."

ERIC Educational Resources Information Center

Koser, John F.

1985-01-01

Describes two contests in which students: (1) build bridges from balsa wood; or (2) construct whizzers (self-contained motorized devices for movement on tight steel wires). Testing situations and guidelines for these contests are included. Points out that physics enrollments have increased as a result of the contests. (DH)

CAMPARE and Cal-Bridge: Two Institutional Networks Increasing Diversity in Astronomy

NASA Astrophysics Data System (ADS)

Rudolph, Alexander L.; Smecker-Hane, Tammy A.

2017-01-01

We describe two programs, CAMPARE and Cal-Bridge, with the common mission of increasing participation of groups traditionally underrepresented in astronomy, through summer research opportunities, in the case of CAMPARE, scholarships in the case of Cal-Bridge, and significant mentoring in both programs, creating a national impact on their numbers successfully pursuing a PhD in the field.In 7 years, the CAMPARE program has sent 80 students, >80% from underrepresented groups, to conduct summer research at one of 14 major research institutions throughout the country. The graduation rate among CAMPARE scholars is 98%, and of the CAMPARE scholars who have graduated with a Bachelor’s degree, more than 60% have completed or are pursuing graduate education in astronomy or a related field, at institutions including UCLA, UC Riverside, UC Irvine, UC Santa Barbara, USC, Stanford, Univ. of Arizona, Univ. of Washington, and the Fisk-Vanderbilt Master’s-to-PhD program.Now entering its third year, the Cal-Bridge program is a CSU-UC Bridge program comprised of over 75 physics and astronomy faculty from 5 University of California (UC), 9 California State University (CSU), and 14 California Community College (CCC) campuses in Southern California. In the first three years, 22 Cal-Bridge Scholars have been selected, including 11 Hispanic, 3 African-American and 8 female students, 5 of whom are from URM groups. Nineteen (19) of the 22 Cal-Bridge Scholars are first-generation college students. The entire first cohort of 4 Cal-Bridge scholars was accepted to one or more PhD programs in astronomy or physics, including UC Irvine, UC Santa Cruz, UC Davis, Michigan State, and Georgia State Universities. The second cohort of 8 Cal-Bridge scholars is applying to graduate schools this fall.Cal-Bridge provides much deeper mentoring and professional development experiences over the last two years of undergraduate and first year of graduate school to students from this diverse network of higher education institutions. Cal-Bridge Scholars benefit from substantial financial support, intensive, joint mentoring by CSU and UC faculty, professional development workshops, and exposure to research opportunities at the participating UC campuses.

The Correlated Lecture Laboratory Series in Diagnostic Radiological Physics.

ERIC Educational Resources Information Center

Lamel, David A.; And Others

This series in diagnostic radiological physics has been designed to provide the physics background requisite for the proper conduct of medical diagnostic x-ray examinations. The basic goal of the series is to bridge physics theory and radiological practice, achieved by combining pertinent lecture material with laboratory exercises that illustrate…

[Three-point bending moment of two types of resin for temporary bridges after reinforcement with glass fibers].

PubMed

Didia, E E; Akon, A B; Thiam, A; Djeredou, K B

2010-03-01

One of the concerns of the dental surgeon in the realization of any operational act is the durability of this one. The mechanical resistance of the provisional prostheses contributes in a large part to the durability of those. The resins in general, have weak mechanical properties. The purpose of this study is to evaluate the resistance in inflection of temporary bridges reinforced with glass fibre. To remedy the weak mechanical properties of resins, we thought in this study, to reinforce them with glass fibres. For this purpose, we realized with two different resins, four groups of temporary bridges of 3 elements, including two groups reinforced fibreglass and the others not. Tests of inflection 3 points have been made on these bridges and resistance to fracture was analysed. The statistical tests showed a significant difference in four groups with better resistance for the reinforced bridges.

Association between sella turcica bridging and palatal canine impaction: Evaluation using lateral cephalograms and CBCT.

PubMed

El Wak, Terry; Akl, Roula; Mati, Myriam; Khoury, Elie; Ghoubril, Joseph

2018-06-01

The purpose of this study was to find a correlation between sella turcica bridging and the presence of a palatal impacted canine, using lateral cephalograms and CBCT. We selected the lateral cephalograms and CBCTs of 60 patients meeting specific criteria. The radiographs were analysed to study the relationship between sella turca bridging and several factors. The presence or absence of a partial or total bridging was deducted by measuring the dimensions of the sella turcica and by using an accurate scoring system. Our study did not show any statistically significant association between sella turcica bridging as diagnosed on the lateral cephalogram and the CBCT images and the following factors: age, gender, facial type, skeletal class and the presence of an impacted canine. We found a significant difference for the classification of the sella turcica between these two radiographic methods. Copyright © 2018. Published by Elsevier Masson SAS.

Dynamic and Fatigue Analysis of an 18th Century Steel Arch Bridge

NASA Astrophysics Data System (ADS)

Boumechra, Nadir; Hamdaoui, Karim

2008-07-01

Within the "Oran-Tlemcen" railway line realization project (159 km), several bridges were built by the Railroads Algerian West Company. 7 km from the east of Tlemcen city, this railway line must cross a very broken mountainous collar, that's why the French engineer "Gustave Eiffel" was solicited to construct a 68 m length bridge. In 1890, an arch steel truss bridge was realized. The bridge presents 300 m of apron curvature radius and, currently, is considered as one of the most important monuments of the Algerian historical heritage. Considering the age of the bridge and the evolution of the railway loads in time, it was essential to check the good behavior of the studied structure. For that, analyses to verify the physical and mechanical properties of the growth iron members are made. A finite element model of the bridge was built and numerical simulations were drawn. The structural vibration conducted analysis permit to understand the behavior of this particular structure, then to evaluate (in detail) the rate of the structure fatigue.

Investigating the Associations between Ethnic Networks, Community Social Capital, and Physical Health among Marriage Migrants in Korea.

PubMed

Kim, Harris Hyun-Soo

2018-01-17

This study examines factors associated with the physical health of Korea's growing immigrant population. Specifically, it focuses on the associations between ethnic networks, community social capital, and self-rated health (SRH) among female marriage migrants. For empirical testing, secondary analysis of a large nationally representative sample (NSMF 2009) is conducted. Given the clustered data structure (individuals nested in communities), a series of two-level random intercepts and slopes models are fitted to probe the relationships between SRH and interpersonal (bonding and bridging) networks among foreign-born wives in Korea. In addition to direct effects, cross-level interaction effects are investigated using hierarchical linear modeling. While adjusting for confounders, bridging (inter-ethnic) networks are significantly linked with better health. Bonding (co-ethnic) networks, to the contrary, are negatively associated with immigrant health. Net of individual-level covariates, living in a commuijnity with more aggregate bridging social capital is positively linked with health. Community-level bonding social capital, however, is not a significant predictor. Lastly, two cross-level interaction terms are found. First, the positive relationship between bridging network and health is stronger in residential contexts with more aggregate bridging social capital. Second, it is weaker in communities with more aggregate bonding social capital.

Bridging Physics and Biology Using Resistance and Axons

ERIC Educational Resources Information Center

Dyer, Joshua M.

2014-01-01

When teaching physics, it is often difficult to get biology-oriented students to see the relevance of physics. A complaint often heard is that biology students are required to take physics for the Medical College Admission Test (MCAT) as part of a "weeding out" process, but that they don't feel like they need physics for biology. Despite…

Contest Physics.

ERIC Educational Resources Information Center

Moehnke, Randy

1994-01-01

Discusses the use of contests to keep physics interesting and exciting for the students. Includes: balloon car, egg drop, tennis ball catapult, bridge building, mousetrap vehicle, musical instrument, slide photo, electric junk dissection, windmill generator, and solar heater. (MVL)

Bridging Physics to Electronics--An Outreach Effort

ERIC Educational Resources Information Center

Tan, Kok-Kiong; Tang, Kok-Zuea; Ng, Vivian; Tay, Arthur; Yen, Shih-Cheng; Lee, Tong-Heng

2010-01-01

Physics has been an important part of the science curriculum in high schools. Without the appropriate high school physics background, it is difficult for a student subsequently to pursue an electronics engineering program at the university level since a good understanding of many concepts in physics is required to comprehend the material covered…

Minimally Invasive Osteosynthesis with a Bridge Plate Versus a Functional Brace for Humeral Shaft Fractures: A Randomized Controlled Trial.

PubMed

Matsunaga, Fabio Teruo; Tamaoki, Marcel Jun Sugawara; Matsumoto, Marcelo Hide; Netto, Nicola Archetti; Faloppa, Flavio; Belloti, Joao Carlos

2017-04-05

Nonoperative treatment has historically been considered the standard for fractures of the shaft of the humerus. Minimally invasive bridge-plate osteosynthesis for isolated humeral shaft fractures has been proven to be a safe technique, with good and reproducible results. This study was designed to compare clinical and radiographic outcomes between patients who had been treated with bridge plate osteosynthesis and those who had been managed nonoperatively with a functional brace. A prospective randomized trial was designed and included 110 patients allocated to 1 of 2 groups: surgery with a bridge plate or nonoperative treatment with a functional brace. The primary outcome was the Disabilities of the Arm, Shoulder and Hand (DASH) score at 6 months. The score on the Short Form-36 (SF-36) life-quality questionnaire, complications of treatment, Constant-Murley score for the shoulder, pain level, and radiographic results were assessed as secondary outcomes. Participants were assessed at 2 weeks; 1, 2, and 6 months; and 1 year after the interventions. The mean DASH score of the bridge plate group was statistically superior to that of the functional brace group (mean scores, 10.9 and 16.9, respectively; p = 0.046) only at 6 months. The bridge plate group also had a significantly more favorable nonunion rate (0% versus 15%) and less mean residual angular displacement seen on the anteroposterior radiograph (2.0° versus 10.5°) (both p < 0.05). No difference between the groups was detected with regard to the SF-36 score, pain level, Constant-Murley score, or angular displacement seen on the lateral radiograph. This trial demonstrates that, compared with functional bracing, surgical treatment with a bridge plate has a statistically significant advantage, of uncertain clinical benefit, with respect to self-reported outcome (DASH score) at 6 months, nonunion rate, and residual deformity in the coronal plane as seen on radiographs. Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Seismic fragility analysis of typical pre-1990 bridges due to near- and far-field ground motions

NASA Astrophysics Data System (ADS)

Mosleh, Araliya; Razzaghi, Mehran S.; Jara, José; Varum, Humberto

2016-03-01

Bridge damages during the past earthquakes caused several physical and economic impacts to transportation systems. Many of the existing bridges in earthquake prone areas are pre-1990 bridges and were designed with out of date regulation codes. The occurrences of strong motions in different parts of the world show every year the vulnerability of these structures. Nonlinear dynamic time history analyses were conducted to assess the seismic vulnerability of typical pre-1990 bridges. A family of existing concrete bridge representative of the most common bridges in the highway system in Iran is studied. The seismic demand consists in a set of far-field and near-field strong motions to evaluate the likelihood of exceeding the seismic capacity of the mentioned bridges. The peak ground accelerations (PGAs) were scaled and applied incrementally to the 3D models to evaluate the seismic performance of the bridges. The superstructure was assumed to remain elastic and the nonlinear behavior in piers was modeled by assigning plastic hinges in columns. In this study the displacement ductility and the PGA are selected as a seismic performance indicator and intensity measure, respectively. The results show that pre-1990 bridges subjected to near-fault ground motions reach minor and moderate damage states.

Detection and characterization of corrosion of bridge cables by time domain reflectometry

NASA Astrophysics Data System (ADS)

Liu, Wei; Hunsperger, Robert G.; Folliard, Kevin; Chajes, Michael J.; Barot, Jignesh; Jhaveri, Darshan; Kunz, Eric

1999-02-01

In this paper, we develop and demonstrate a nondestructive evaluation technique for corrosion detection of embedded or encased steel cables. This technique utilizes time domain reflectometry (TDR), which has been traditionally used to detect electrical discontinuities in transmission lines. By applying a sensor wire along with the bridge cable, we can model the cable as an asymmetric, twin-conductor transmission line. Physical defects of the bridge cable will change the electromagnetic properties of the line and can be detected by TDR. Furthermore, different types of defects can be modeled analytically, and identified using TDR. TDR measurement results from several fabricated bridge cable sections with built-in defects are reported.

The effects of bridge exercise on an unstable base of support on lumbar stability and the thickness of the transversus abdominis.

PubMed

Cho, Misuk; Jeon, Hyewon

2013-06-01

[Purpose] We examined the effects of an abdominal drawing-in bridge exercise using a pressure biofeedback unit on different bases on the thickness of trunk and abdominal muscles, and lumbar stability. [Subjects] Thirty healthy young adults (2 males, 28 females) took part in this study. The subjects were randomly and equally assigned to a stable bridge exercise group and an unstable bridge exercise group. [Methods] The subjects performed bridge exercises using an abdominal drawing-in method on a stable base and on an unstable base, and changes in their abdominal muscle thickness and on the stable and on unstable bases lumbar stability were evaluated. [Results] After the intervention, the stable bridge exercise group showed a statistically significantly increased muscle thickness in the transversus abdominis, and the unstable bridge exercise group showed significantly increased muscle thicknesses of the transversus abdominis and internal obliques in static and dynamic lumbar stability. The unstable bridge exercise group showed significant increase after performing the exercise. [Conclusion] Lumbar stability exercise, with the compensation of the lumbar spine minimized, using an abdominal drawing-in method on an unstable support of base is effective and efforts to prevent the compensation may induce a greater exercise effect.

Damage detection in bridges through fiber optic structural health monitoring

NASA Astrophysics Data System (ADS)

Doornink, J. D.; Phares, B. M.; Wipf, T. J.; Wood, D. L.

2006-10-01

A fiber optic structural health monitoring (SHM) system was developed and deployed by the Iowa State University (ISU) Bridge Engineering Center (BEC) to detect gradual or sudden damage in fracture-critical bridges (FCBs). The SHM system is trained with measured performance data, which are collected by fiber optic strain sensors to identify typical bridge behavior when subjected to ambient traffic loads. Structural responses deviating from the trained behavior are considered to be signs of structural damage or degradation and are identified through analytical procedures similar to control chart analyses used in statistical process control (SPC). The demonstration FCB SHM system was installed on the US Highway 30 bridge near Ames, IA, and utilizes 40 fiber bragg grating (FBG) sensors to continuously monitor the bridge response when subjected to ambient traffic loads. After the data is collected and processed, weekly evaluation reports are developed that summarize the continuous monitoring results. Through use of the evaluation reports, the bridge owner is able to identify and estimate the location and severity of the damage. The information presented herein includes an overview of the SHM components, results from laboratory and field validation testing on the system components, and samples of the reduced and analyzed data.

The effect of bridge exercise accompanied by the abdominal drawing-in maneuver on an unstable support surface on the lumbar stability of normal adults.

PubMed

Gong, Wontae

2015-01-01

[Purpose] The present study sought to investigate the influence on static and dynamic lumbar stability of bridge exercise accompanied by an abdominal drawing-in maneuver (ADIM) performed on an uneven support surface. [Subjects] A total of 30 participants were divided into an experimental group (15 participants) and a control group (15 participants). [Methods] The experimental group performed bridge exercise on an unstable surface, whereas the control group performed bridge exercise on a stable surface. The respective bridge exercises were performed for 30 minutes, 3 times per week, for 6 weeks. The static lumbar stability (SLS) and dynamic lumbar stability (DLS) of both the experimental group and the control group were measured using a pressure biofeedback unit. [Results] In the comparison of the initial and final results of the experimental and control groups, only the SLS and DLS of the experimental group were found to be statistically significant. [Conclusion] The results of the present study show that when using bridge exercise to improve SLS and DLS, performing the bridge exercise accompanied by ADIM on an uneven surface is more effective than performing the exercise on a stable surface.

Enhancing Learning in Statistics Classes Through The Use of Concrete Historical Examples: The Space Shuttle Challenger, Pearl Harbor, and the RMS Titanic.

ERIC Educational Resources Information Center

Schumm, Walter R.; Webb, Farrell J.; Castelo, Carlos S.; Akagi, Cynthia G.; Jensen, Erick J.; Ditto, Rose M.; Spencer Carver, Elaine; Brown, Beverlyn F.

2002-01-01

Discusses the use of historical events as examples for teaching college level statistics courses. Focuses on examples of the space shuttle Challenger, Pearl Harbor (Hawaii), and the RMS Titanic. Finds real life examples can bridge a link to short term experiential learning and provide a means for long term understanding of statistics. (KDR)

A Guide to Disability Statistics from the Behavioral Risk Factors Surveillance System. Disability Statistics User Guide Series

ERIC Educational Resources Information Center

Erickson, William A.; Dumoulin-Smith, Adrien

2009-01-01

The mission of the Cornell StatsRRTC is to bridge the divide between the sources of disability data and the users of disability statistics. One product of this effort is a set of "User Guides" to national survey data that collect information on the disability population. The purpose of each of the "User Guides" is to provide…

Salt-Bridge Energetics in Halophilic Proteins

PubMed Central

Nayek, Arnab; Sen Gupta, Parth Sarthi; Banerjee, Shyamashree; Mondal, Buddhadev; Bandyopadhyay, Amal K.

2014-01-01

Halophilic proteins have greater abundance of acidic over basic and very low bulky hydrophobic residues. Classical electrostatic stabilization was suggested as the key determinant for halophilic adaptation of protein. However, contribution of specific electrostatic interactions (i.e. salt-bridges) to overall stability of halophilic proteins is yet to be understood. To understand this, we use Adaptive-Poison-Boltzmann-Solver Methods along with our home-built automation to workout net as well as associated component energy terms such as desolvation energy, bridge energy and background energy for 275 salt-bridges from 20 extremely halophilic proteins. We then perform extensive statistical analysis on general and energetic attributes on these salt-bridges. On average, 8 salt-bridges per 150 residues protein were observed which is almost twice than earlier report. Overall contributions of salt-bridges are −3.0 kcal mol−1. Majority (78%) of salt-bridges in our dataset are stable and conserved in nature. Although, average contributions of component energy terms are equal, their individual details vary greatly from one another indicating their sensitivity to local micro-environment. Notably, 35% of salt-bridges in our database are buried and stable. Greater desolvation penalty of these buried salt-bridges are counteracted by stable network salt-bridges apart from favorable equal contributions of bridge and background terms. Recruitment of extensive network salt-bridges (46%) with a net contribution of −5.0 kcal mol−1 per salt-bridge, seems to be a halophilic design wherein favorable average contribution of background term (−10 kcal mol−1) exceeds than that of bridge term (−7 kcal mol−1). Interiors of proteins from halophiles are seen to possess relatively higher abundance of charge and polar side chains than that of mesophiles which seems to be satisfied by cooperative network salt-bridges. Overall, our theoretical analyses provide insight into halophilic signature in its specific electrostatic interactions which we hope would help in protein engineering and bioinformatics studies. PMID:24743799

Salt-bridge energetics in halophilic proteins.

PubMed

Nayek, Arnab; Sen Gupta, Parth Sarthi; Banerjee, Shyamashree; Mondal, Buddhadev; Bandyopadhyay, Amal K

2014-01-01

Halophilic proteins have greater abundance of acidic over basic and very low bulky hydrophobic residues. Classical electrostatic stabilization was suggested as the key determinant for halophilic adaptation of protein. However, contribution of specific electrostatic interactions (i.e. salt-bridges) to overall stability of halophilic proteins is yet to be understood. To understand this, we use Adaptive-Poison-Boltzmann-Solver Methods along with our home-built automation to workout net as well as associated component energy terms such as desolvation energy, bridge energy and background energy for 275 salt-bridges from 20 extremely halophilic proteins. We then perform extensive statistical analysis on general and energetic attributes on these salt-bridges. On average, 8 salt-bridges per 150 residues protein were observed which is almost twice than earlier report. Overall contributions of salt-bridges are -3.0 kcal mol-1. Majority (78%) of salt-bridges in our dataset are stable and conserved in nature. Although, average contributions of component energy terms are equal, their individual details vary greatly from one another indicating their sensitivity to local micro-environment. Notably, 35% of salt-bridges in our database are buried and stable. Greater desolvation penalty of these buried salt-bridges are counteracted by stable network salt-bridges apart from favorable equal contributions of bridge and background terms. Recruitment of extensive network salt-bridges (46%) with a net contribution of -5.0 kcal mol-1 per salt-bridge, seems to be a halophilic design wherein favorable average contribution of background term (-10 kcal mol-1) exceeds than that of bridge term (-7 kcal mol-1). Interiors of proteins from halophiles are seen to possess relatively higher abundance of charge and polar side chains than that of mesophiles which seems to be satisfied by cooperative network salt-bridges. Overall, our theoretical analyses provide insight into halophilic signature in its specific electrostatic interactions which we hope would help in protein engineering and bioinformatics studies.

Skin bridge versus rod colostomy in children - comparison between complications.

PubMed

Askarpour, Shahnam; Peyvasteh, Mehran; Changai, Bahram; Javaherizadeh, Hazhir

2012-10-01

Due to economic problems, sigmoid loop colostomy using glass rod may cause problems for our patients for finding glass rod and several visits. The aim of the study was to compare rod versus skin bridge colostomy. In this study, 42 cases who are candidate for colostomy were included. Cases were randomly placed in skin bridge and rod colostomy group. Independent sample t-test and Chi-square were used for comparison. SPSS version 16.0 (SPSS Inc, Chicago, IL, USA) was used for analysis. Of 42 cases, 20 were male and 22 were female. Hirschsprung's disease was the indication of colostomy in 33 cases. In nine cases, imperforate anus was the indication of colostomy. Mean time of surgery was 79.4 and 82.5 minute for the rod and skin bridge group respectively (P>0.05). Retraction was seen in 2 case of rod group, and no case of skin bridge group. Prolapse was seen in 2 (9.5%) case of rod group and 1(4.7%) case in skin bridge. There were no reports of necrosis, stenosis, and hernia in both groups. In the skin bridge group the rates of complications were lower but the groups are too small for statistical analysis. Colostomy with a skin bridge method may decrease number of revision and expenses and may be appropriate option. Sigmoid loop colostomy using skin bridge flap may be appropriate choice in developing country. Another study with more samples is recommended to better comparison of Skin Bridge versus rod colostomy.

The effect of bridge exercise method on the strength of rectus abdominis muscle and the muscle activity of paraspinal muscles while doing treadmill walking with high heels.

PubMed

Kang, Taewook; Lee, Jaeseok; Seo, Junghoon; Han, Dongwook

2017-04-01

[Purpose] The purpose of this research is to investigate the effect of the method of bridge exercise on the change of rectus abdominis muscle and the muscle activity of paraspinal muscles while doing treadmill walking with high heels. [Subjects and Methods] The subjects of this research are healthy female students consisting of 10 persons performing bridge exercises in a supine group, 10 persons performing bridge exercises in a prone group, and 10 persons in a control group while in S university in Busan. Bridge exercise in supine position is performed in hook lying position. Bridge exercise in prone position is plank exercise in prostrate position. To measure the strength of rectus abdominis muscle, maintaining times of the posture was used. To measure the muscle activity of paraspinal muscles, EMG (4D-MT & EMD-11, Relive, Korea) was used. [Results] The strength of rectus abdominis muscle of both bridge exercises in the supine group and bridge exercises in the prone group increases significantly after exercise. The muscle activity of paraspinal muscle such as thoracic parts and lumbar parts in bridge exercises in the prone group decreases statistically while walking on a treadmill with high heels. Muscle activity of thoracic parts paraspinal muscle and bridge exercises in the supine group decreased significantly. [Conclusion] According to this study, we noticed that bridge exercise in a prone position is desirable for women who prefer wearing high heels as a back pain prevention exercise method.

Man's Response to the Physical Environment.

ERIC Educational Resources Information Center

Kates, R.W., Ed.; Wohlwill, J.F., Ed.

1966-01-01

Architects, psychologists, geographers, and biologists discuss the impact of the physical environment on man, and his adaptation to it. Article titles are as follows--(1) Galloping Technology, A New Social Disease, (2) Stimulus and Symbol: The View from the Bridge, (3) The Physical Environment: A Problem for a Psychology of Stimulation, (4)…

The Context of Ethnicity: Peer Victimization and Adjustment Problems in Early Adolescence

ERIC Educational Resources Information Center

Hoglund, Wendy L. G.; Hosan, Naheed E.

2013-01-01

The current study bridges research on peer relational and physical victimization with research on ethnic victimization and situates this research in the context of ethnic diversity. Specifically, the authors investigate how ethnic, relational, and physical victimization relate to concurrent levels of depression/anxiety and physical aggression and…

A methodology for the rigorous verification of plasma simulation codes

NASA Astrophysics Data System (ADS)

Riva, Fabio

2016-10-01

The methodology used to assess the reliability of numerical simulation codes constitutes the Verification and Validation (V&V) procedure. V&V is composed by two separate tasks: the verification, which is a mathematical issue targeted to assess that the physical model is correctly solved, and the validation, which determines the consistency of the code results, and therefore of the physical model, with experimental data. In the present talk we focus our attention on the verification, which in turn is composed by the code verification, targeted to assess that a physical model is correctly implemented in a simulation code, and the solution verification, that quantifies the numerical error affecting a simulation. Bridging the gap between plasma physics and other scientific domains, we introduced for the first time in our domain a rigorous methodology for the code verification, based on the method of manufactured solutions, as well as a solution verification based on the Richardson extrapolation. This methodology was applied to GBS, a three-dimensional fluid code based on a finite difference scheme, used to investigate the plasma turbulence in basic plasma physics experiments and in the tokamak scrape-off layer. Overcoming the difficulty of dealing with a numerical method intrinsically affected by statistical noise, we have now generalized the rigorous verification methodology to simulation codes based on the particle-in-cell algorithm, which are employed to solve Vlasov equation in the investigation of a number of plasma physics phenomena.

Dynamic and Fatigue Analysis of an 18{sup th} Century Steel Arch Bridge

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

Boumechra, Nadir; Hamdaoui, Karim

2008-07-08

Within the 'Oran-Tlemcen' railway line realization project (159 km), several bridges were built by the Railroads Algerian West Company. 7 km from the east of Tlemcen city, this railway line must cross a very broken mountainous collar, that's why the French engineer 'Gustave Eiffel' was solicited to construct a 68 m length bridge. In 1890, an arch steel truss bridge was realized. The bridge presents 300 m of apron curvature radius and, currently, is considered as one of the most important monuments of the Algerian historical heritage. Considering the age of the bridge and the evolution of the railway loadsmore » in time, it was essential to check the good behavior of the studied structure. For that, analyses to verify the physical and mechanical properties of the growth iron members are made. A finite element model of the bridge was built and numerical simulations were drawn. The structural vibration conducted analysis permit to understand the behavior of this particular structure, then to evaluate (in detail) the rate of the structure fatigue.« less

Shearing of nanoscopic bridges in two-component thin liquid layers between chemically patterned walls.

PubMed

Hemming, C J; Patey, G N

2004-10-01

Bridge phases associated with a phase transition between two liquid phases occur when a two-component liquid mixture is confined between chemically patterned walls. In the bulk the liquid mixture with components A, B undergoes phase separation into an A-rich phase and a B-rich phase. The walls bear stripes attractive to A. In the bridge phase A-rich and B-rich regions alternate. Grand canonical Monte Carlo studies are performed with the alignment between stripes on opposite walls varied. Misalignment of the stripes places the nanoscopic liquid bridges under shear strain. The bridges exert a Hookean restoring force on the walls for small displacements from equilibrium. As the strain increases there are deviations from Hooke's law. Eventually there is an abrupt yielding of the bridges. Molecular dynamics simulations show the bridges form or disintegrate on time scales which are fast compared to wall motion and transport of molecules into or from the confined space. Some interesting possible applications of the phenomena are discussed. (c) 2004 American Institute of Physics

GPCC - A weather generator-based statistical downscaling tool for site-specific assessment of climate change impacts

USDA-ARS?s Scientific Manuscript database

Resolution of climate model outputs are too coarse to be used as direct inputs to impact models for assessing climate change impacts on agricultural production, water resources, and eco-system services at local or site-specific scales. Statistical downscaling approaches are usually used to bridge th...

[Physical and mechanical properties of the thermosetting resin for crown and bridge cured by micro-wave heating].

PubMed

Kaneko, K

1989-09-01

A heating method using micro-waves was utilized to obtain strong thermosetting resin for crown and bridge. The physical and mechanical properties of the thermosetting resin were examined. The resin was cured in a shorter time by the micro-waves heating method than by the conventional heat curing method and the working time was reduced markedly. The base resins of the thermosetting resin for crown and bridge for the micro-waves heating method were 2 PA and diluent 3 G. A compounding volume of 30 wt% for diluent 3 G was considered good the results of compressive strength, bending strength and diametral tensile strength. Grams of 200-230 of the filler compounded to the base resins of 2 PA-3 G system provided optimal compressive strength, bending strength and diametral tensile strength. A filler gram of 230 provided optimal hardness and curing shrinkage rate, the coefficient of thermal expansion became smaller with the increase of the compounding volume of the filler. The trial thermosetting resin for crown and bridge formed by the micro-waves heating method was not inferior to the conventional resin by the heat curing method or the light curing method.

Continuum mesoscopic framework for multiple interacting species and processes on multiple site types and/or crystallographic planes.

PubMed

Chatterjee, Abhijit; Vlachos, Dionisios G

2007-07-21

While recently derived continuum mesoscopic equations successfully bridge the gap between microscopic and macroscopic physics, so far they have been derived only for simple lattice models. In this paper, general deterministic continuum mesoscopic equations are derived rigorously via nonequilibrium statistical mechanics to account for multiple interacting surface species and multiple processes on multiple site types and/or different crystallographic planes. Adsorption, desorption, reaction, and surface diffusion are modeled. It is demonstrated that contrary to conventional phenomenological continuum models, microscopic physics, such as the interaction potential, determines the final form of the mesoscopic equation. Models of single component diffusion and binary diffusion of interacting particles on single-type site lattice and of single component diffusion on complex microporous materials' lattices consisting of two types of sites are derived, as illustrations of the mesoscopic framework. Simplification of the diffusion mesoscopic model illustrates the relation to phenomenological models, such as the Fickian and Maxwell-Stefan transport models. It is demonstrated that the mesoscopic equations are in good agreement with lattice kinetic Monte Carlo simulations for several prototype examples studied.

Quantum Dots: An Experiment for Physical or Materials Chemistry

ERIC Educational Resources Information Center

Winkler, L. D.; Arceo, J. F.; Hughes, W. C.; DeGraff, B. A.; Augustine, B. H.

2005-01-01

An experiment is conducted for obtaining quantum dots for physical or materials chemistry. This experiment serves to both reinforce the basic concept of quantum confinement and providing a useful bridge between the molecular and solid-state world.

River meander modeling of the Wabash River near the Interstate 64 Bridge near Grayville, Illinois

USGS Publications Warehouse

Lant, Jeremiah G.; Boldt, Justin A.

2018-01-16

Natural river channels continually evolve and change shape over time. As a result, channel evolution or migration can cause problems for bridge structures that are fixed in the flood plain. A once-stable bridge structure that was uninfluenced by a river’s shape could be encroached upon by a migrating river channel. The potential effect of the actively meandering Wabash River on the Interstate 64 Bridge at the border with Indiana near Grayville, Illinois, was studied using a river migration model called RVR Meander. RVR Meander is a toolbox that can be used to model river channel meander migration with physically based bank erosion methods. This study assesses the Wabash River meandering processes through predictive modeling of natural meandering over the next 100 years, climate change effects through increased river flows, and bank protection measures near the Interstate 64 Bridge.

Atomistic mechanisms of ReRAM cell operation and reliability

NASA Astrophysics Data System (ADS)

Pandey, Sumeet C.

2018-01-01

We present results from first-principles-based modeling that captures functionally important physical phenomena critical to cell materials selection, operation, and reliability for resistance-switching memory technologies. An atomic-scale description of retention, the low- and high-resistance states (RS), and the sources of intrinsic cell-level variability in ReRAM is discussed. Through the results obtained from density functional theory, non-equilibrium Green’s function, molecular dynamics, and kinetic Monte Carlo simulations; the role of variable-charge vacancy defects and metal impurities in determining the RS, the LRS-stability, and electron-conduction in such RS is reported. Although, the statistical electrical characteristics of the oxygen-vacancy (Ox-ReRAM) and conductive-bridging RAM (M-ReRAM) are notably different, the underlying similar electrochemical phenomena describing retention and formation/dissolution of RS are being discussed.

Error Sources in Proccessing LIDAR Based Bridge Inspection

NASA Astrophysics Data System (ADS)

Bian, H.; Chen, S. E.; Liu, W.

2017-09-01

Bridge inspection is a critical task in infrastructure management and is facing unprecedented challenges after a series of bridge failures. The prevailing visual inspection was insufficient in providing reliable and quantitative bridge information although a systematic quality management framework was built to ensure visual bridge inspection data quality to minimize errors during the inspection process. The LiDAR based remote sensing is recommended as an effective tool in overcoming some of the disadvantages of visual inspection. In order to evaluate the potential of applying this technology in bridge inspection, some of the error sources in LiDAR based bridge inspection are analysed. The scanning angle variance in field data collection and the different algorithm design in scanning data processing are the found factors that will introduce errors into inspection results. Besides studying the errors sources, advanced considerations should be placed on improving the inspection data quality, and statistical analysis might be employed to evaluate inspection operation process that contains a series of uncertain factors in the future. Overall, the development of a reliable bridge inspection system requires not only the improvement of data processing algorithms, but also systematic considerations to mitigate possible errors in the entire inspection workflow. If LiDAR or some other technology can be accepted as a supplement for visual inspection, the current quality management framework will be modified or redesigned, and this would be as urgent as the refine of inspection techniques.

Comparison of radiological and morphologic assessments of myocardial bridges.

PubMed

Ercakmak, Burcu; Bulut, Elif; Hayran, Mutlu; Kaymaz, Figen; Bilgin, Selma; Hazirolan, Tuncay; Bayramoglu, Alp; Erbil, Mine

2015-09-01

In this study we aimed to compare the findings of coronary dual-source computed tomography angiography of myocardial bridges with cadaveric dissections. Forty-one isolated, non-damaged fresh sheep hearts were used in this study. Myocardial bridges of the anterior interventricular branch of the left coronary artery were demonstrated and analyzed by a coronary dual-source computed tomography angiography. Dissections along the left anterior interventricular branch of the left coronary artery were performed by using Zeiss OPMI pico microscope and the length of the bridges were measured. The depths of the myocardial bridges were measured from the stained sections by using the light microscope (Leica DM 6000B). MBs were found in all 41 hearts (100%) during dissections. Dual-source computed tomography angiography successfully detected 87.8% (36 of the 41 hearts) of the myocardial bridges measured on left anterior interventricular branch of left coronary artery. The lengths of the myocardial bridges were found 5-40 and 8-50 mm with dissection and dual-source computed tomography angiography, respectively. And the depths were found 0.7-4.5 mm by dual-source computed tomography angiography and 0.745-4.632 mm morphologically. Comparison of the mean values of the lengths showed statistically significantly higher values (22.0 ± 8.5, 17.7 ± 7.7 mm, p = 0.003) for the dissections. Radiological assessment also effectively discriminated complete bridges from incomplete ones. Our study showed that coronary computed tomography angiography is reliable in evaluating the presence and depth of myocardial bridges.

Domain Decomposition: A Bridge between Nature and Parallel Computers

DTIC Science & Technology

1992-09-01

B., "Domain Decomposition Algorithms for Indefinite Elliptic Problems," S"IAM Journal of S; cientific and Statistical (’omputing, Vol. 13, 1992, pp...AD-A256 575 NASA Contractor Report 189709 ICASE Report No. 92-44 ICASE DOMAIN DECOMPOSITION: A BRIDGE BETWEEN NATURE AND PARALLEL COMPUTERS DTIC dE...effectively implemented on dis- tributed memory multiprocessors. In 1990 (as reported in Ref. 38 using the tile algo- rithm), a 103,201-unknown 2D elliptic

Understanding the interactions between Social Capital, climate change, and community resilience in Gulf of Mexico coastal counties

NASA Astrophysics Data System (ADS)

Young, C.; Blomberg, B.; Kolker, A.; Nguyen, U.; Page, C. M.; Sherchan, S. P.; Tobias, V. D.; Wu, H.

2017-12-01

Coastal communities in the Gulf of Mexico are facing new and complex challenges as their physical environment is altered by climate warming and sea level rise. To effectively prepare for environmental changes, coastal communities must build resilience in both physical structures and social structures. One measure of social structure resilience is how much social capital a community possesses. Social capital is defined as the connections among individuals which result in networks with shared norms, values and understandings that facilitate cooperation within or among groups. Social capital exists in three levels; bonding, bridging and linking. Bonding social capital is a measure of the strength of relationships amongst members of a network who are similar in some form. Bridging social capital is a measure of relationships amongst people who are dissimilar in some way, such as age, education, or race/ethnicity. Finally Linking social capital measures the extent to which individuals build relationships with institutions and individuals who have relative power over them (e.g local government, educational institutions). Using census and American Community Survey data, we calculated a Social Capital index value for bonding, bridging and linking for 60 Gulf of Mexico coastal counties for the years 2000, and 2010 to 2015. To investigate the impact of social capital on community resilience we coupled social capital index values with physical datasets of land-use/land cover, sea level change, climate, elevation and surface water quality for each coastal county in each year. Preliminary results indicate that in Gulf of Mexico coastal counties, increased bonding social capital results in decreased population change. In addition, we observed a multi-year time lag in the effect of increased bridging social capital on population stability, potentially suggesting key linkages between the physical and social environment in this complex coupled-natural human system. This transdisciplinary study integrated physical and social open science data and provides a better understanding on how increased social capital improves resilience to changes in the physical environment. Thus, by investing in social capital, local governments may have a low cost and non-structural way of increasing community resilience.

Physics Notes.

ERIC Educational Resources Information Center

School Science Review, 1982

1982-01-01

Discusses dice model of exponential radionuclide decay; glancing and collinear perfectly elastic collisions; digital capacitance meter; use of top pan balance in physics; microcomputer calculation of gradient of straight line (includes complete Commodore PET computer program); Fresnel lenses; low-voltage radiant heater; Wheatssone's bridge used as…

Meaningful Statistics in Professional Practices as a Bridge between Mathematics and Science: An Evaluation of a Design Research Project

ERIC Educational Resources Information Center

Dierdorp, Adri; Bakker, Arthur; van Maanen, Jan A.; Eijkelhof, Harrie M. C.

2014-01-01

Background: Creating coherence between school subjects mathematics and science and making these school subjects meaningful are still topical challenges. This study investigates how students make meaningful connections between mathematics, statistics, science and applications when they engage in a specially developed unit that is based on…

Scour assessments and sediment-transport simulation for selected bridge sites in South Dakota

USGS Publications Warehouse

Niehus, C.A.

1996-01-01

Scour at bridges is a major concern in the design of new bridges and in the evaluation of structural stability of existing bridges. Equations for estimating pier, contraction, and abutment scour have been developed from numerous laboratory studies using sand-bed flumes, but little verification of these scour equations has been done for actual rivers with various bed conditions. This report describes the results of reconnaissance and detailed scour assessments and a sediment-transport simulation for selected bridge sites in South Dakota. Reconnaissance scour assessments were done during 1991 for 32 bridge sites. The reconnaissance assessments for each bridge site included compilation of general and structural data, field inspection to record and measure pertinent scour variables, and evaluation of scour susceptibility using various scour-index forms. Observed pier scour at the 32 sites ranged from 0 to 7 feet, observed contraction scour ranged from 0 to 4 feet, and observed abutment scour ranged from 0 to 10 feet. Thirteen bridge sites having high potential for scour were selected for detailed assessments, which were accomplished during 1992-95. These detailed assessments included prediction of scour depths for 2-, 100-, and 500-year flows using selected published scour equations; measurement of scour during high flows; comparison of measured and predicted scour; and identification of which scour equations best predict actual scour. The medians of predicted pier-scour depth at each of the 13 bridge sites (using 13 scour equations) ranged from 2.4 to 6.8 feet for the 2-year flows and ranged from 3.4 to 13.3 feet for the 500-year flows. The maximum pier scour measured during high flows ranged from 0 to 8.5 feet. Statistical comparison (Spearman rank correlation) of predicted pier-scour depths (using flow data col- lected during scour measurements) indicate that the Laursen, Shen (method b), Colorado State University, and Blench (method b) equations correlate closer with measured scour than do the other prediction equations. The predicted pier-scour depths using the Varzeliotis and Carstens equations have weak statistical rela- tions with measured scour depths. Medians of predicted pier-scour depth from the Shen (method a), Chitale, Bata, and Carstens equations are statistically equal to the median of measured pier-scour depths, based on the Wilcoxon signed-ranks test. The medians of contraction scour depth at each of the 13 bridge sites (using one equation) ranged from -0.1 foot for the 2- year flows to 23.2 feet for the 500-year flows. The maximum contraction scour measured during high flows ranged from 0 to 3.0 feet. The contraction- scour prediction equation substantially overestimated the scour depths in almost all comparisons with the measured scour depths. A significant reason for this discrepancy is due to the wide flood plain (as wide as 5,000 feet) at most of the bridge sites that were investigated. One possible way to reduce this effect for bridge design is to make a decision on what is the effective approach section and thereby limit the size of the bridge flow approach width. The medians of abutment-scour depth at each of the 13 bridge sites (using five equations) ranged from 8.2 to 16.5 feet for the 2-year flows and ranged from 5.7 to 41 feet for the 500-year flows. The maximum abutment scour measured during high flows ranged from 0 to 4.0 feet. The abutment-scour prediction equations also substantially overestimated the scour depths in almost all comparisons with the measured scour depths. The Liu and others (live bed) equation predicted abutment-scour depths substantially lower than the other four abutment-scour equations and closer to the actual measured scour depths. However, this equation at times predicted greater scour depths for 2-year flows than it did for 500-year flows, making its use highly questionable. Again, limiting the bridge flow approach width would produce more reasonable predicted abutment scour.

Is the Use of a Support Bridge Beneficial for Preventing Stomal Retraction After Loop Ileostomy? A Prospective Nonrandomized Study.

PubMed

Oh, Heung-Kwon; Han, Eon Chul; Song, Yoon Suk; Seo, Mi Sun; Ryoo, Seung-Bum; Jeong, Seung-Yong; Park, Kyu Joo

2015-01-01

A temporary defunctioning loop ileostomy is frequently created during low colorectal or coloanal anastomosis to prevent peritoneal sepsis associated with anastomotic leakage. We investigated whether routine support bridge placement prevents stoma retraction after the formation of a loop ileostomy. Prospective, nonrandomized trial. The study sample comprised 32 consecutive patients who underwent defunctioning loop ileostomy at an academic tertiary care center in Seoul Korea from February to September 2010. Patients were nonrandomly allocated to "no bridge," "short-term bridge" (1 week), and "long-term bridge" (3 weeks) groups based on the surgeon's clinical judgment. Group differences in stoma height changes over time were analyzed. Subjects' mean age was 59.5 (range: 43-82) years, and the male-to-female ratio was 2.2:1.0. The mean heights of the stoma on postoperative day 2 and postoperative month 3, respectively, were 1.07 ± 0.16 cm (mean ± SD) and 0.81 ± 0.17 cm in the no-bridge group, 1.70 ± 0.29 cm and 1.21 ± 0.18 cm in the short-term bridge group, and 1.18 ± 0.16 cm and 1.01 ± 0.20 cm in the long-term bridge group. The changes in the stoma height 3 months after the surgery showed no statistically significant differences among the groups (P = .430). Stoma Quality of Life scores at 3 weeks (47.4 vs 46.1; P = .730) were similar for patients with and without bridges. However, a significantly greater number of patients with bridges reported difficulty with pouch changes compared to those without bridges (72.7% vs 14.3%; P = .002). Routine use of support bridges during loop ileostomy is unnecessary and inconvenient to patients. If a support bridge must be used, it can be removed early.

Self-expanding metallic stent as a bridge to surgery in the treatment of left colon cancer obstruction: Cost-benefit analysis and oncologic results.

PubMed

Flor-Lorente, Blas; Báguena, Gloria; Frasson, Matteo; García-Granero, Alvaro; Cervantes, Andrés; Sanchiz, Vicente; Peña, Andres; Espí, Alejandro; Esclapez, Pedro; García-Granero, Eduardo

2017-03-01

The use of a self-expanding metallic stent as a bridge to surgery in acute malignant left colonic obstruction has been suggested as an alternative treatment to emergency surgery. The aim of the present study was to compare the morbi-mortality, cost-benefit and long-term oncological outcomes of both therapeutic options. This is a prospective, comparative, controlled, non-randomized study (2005-2010) performed in a specialized unit. The study included 82 patients with left colon cancer obstruction treated by stent as a bridge to surgery (n=27) or emergency surgery (n=55) operated with local curative intention. The main outcome measures (postoperative morbi-mortaliy, cost-benefit, stoma rate and long-term oncological outcomes) were compared based on an "intention-to-treat" analysis. There were no significant statistical differences between the two groups in terms of preoperative data and tumor characteristics. The technically successful stenting rate was 88.9% (11.1% perforation during stent placement) and clinical success was 81.4%. No difference was observed in postoperative morbi-mortality rates. The primary anastomosis rate was higher in the bridge to surgery group compared to the emergency surgery group (77.8% vs. 56.4%; P=.05). The mean costs in the emergency surgery group resulted to be €1,391.9 more expensive per patient than in the bridge to surgery group. There was no significant statistical difference in oncological long-term outcomes. The use of self-expanding metalllic stents as a bridge to surgery is a safe option in the urgent treatment of obstructive left colon cancer, with similar short and long-term results compared to direct surgery, inferior mean costs and a higher rate of primary anastomosis. Copyright © 2017 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

Long-Term Deflection Prediction from Computer Vision-Measured Data History for High-Speed Railway Bridges

PubMed Central

Lee, Jaebeom; Lee, Young-Joo

2018-01-01

Management of the vertical long-term deflection of a high-speed railway bridge is a crucial factor to guarantee traffic safety and passenger comfort. Therefore, there have been efforts to predict the vertical deflection of a railway bridge based on physics-based models representing various influential factors to vertical deflection such as concrete creep and shrinkage. However, it is not an easy task because the vertical deflection of a railway bridge generally involves several sources of uncertainty. This paper proposes a probabilistic method that employs a Gaussian process to construct a model to predict the vertical deflection of a railway bridge based on actual vision-based measurement and temperature. To deal with the sources of uncertainty which may cause prediction errors, a Gaussian process is modeled with multiple kernels and hyperparameters. Once the hyperparameters are identified through the Gaussian process regression using training data, the proposed method provides a 95% prediction interval as well as a predictive mean about the vertical deflection of the bridge. The proposed method is applied to an arch bridge under operation for high-speed trains in South Korea. The analysis results obtained from the proposed method show good agreement with the actual measurement data on the vertical deflection of the example bridge, and the prediction results can be utilized for decision-making on railway bridge maintenance. PMID:29747421

Long-Term Deflection Prediction from Computer Vision-Measured Data History for High-Speed Railway Bridges.

PubMed

Lee, Jaebeom; Lee, Kyoung-Chan; Lee, Young-Joo

2018-05-09

Management of the vertical long-term deflection of a high-speed railway bridge is a crucial factor to guarantee traffic safety and passenger comfort. Therefore, there have been efforts to predict the vertical deflection of a railway bridge based on physics-based models representing various influential factors to vertical deflection such as concrete creep and shrinkage. However, it is not an easy task because the vertical deflection of a railway bridge generally involves several sources of uncertainty. This paper proposes a probabilistic method that employs a Gaussian process to construct a model to predict the vertical deflection of a railway bridge based on actual vision-based measurement and temperature. To deal with the sources of uncertainty which may cause prediction errors, a Gaussian process is modeled with multiple kernels and hyperparameters. Once the hyperparameters are identified through the Gaussian process regression using training data, the proposed method provides a 95% prediction interval as well as a predictive mean about the vertical deflection of the bridge. The proposed method is applied to an arch bridge under operation for high-speed trains in South Korea. The analysis results obtained from the proposed method show good agreement with the actual measurement data on the vertical deflection of the example bridge, and the prediction results can be utilized for decision-making on railway bridge maintenance.

Bridging the Particle Physics and Big Data Worlds

NASA Astrophysics Data System (ADS)

Pivarski, James

2017-09-01

For decades, particle physicists have developed custom software because the scale and complexity of our problems were unique. In recent years, however, the ``big data'' industry has begun to tackle similar problems, and has developed some novel solutions. Incorporating scientific Python libraries, Spark, TensorFlow, and machine learning tools into the physics software stack can improve abstraction, reliability, and in some cases performance. Perhaps more importantly, it can free physicists to concentrate on domain-specific problems. Building bridges isn't always easy, however. Physics software and open-source software from industry differ in many incidental ways and a few fundamental ways. I will show work from the DIANA-HEP project to streamline data flow from ROOT to Numpy and Spark, to incorporate ideas of functional programming into histogram aggregation, and to develop real-time, query-style manipulations of particle data.

Wind effects on long-span bridges: Probabilistic wind data format for buffeting and VIV load assessments

NASA Astrophysics Data System (ADS)

Hoffmann, K.; Srouji, R. G.; Hansen, S. O.

2017-12-01

The technology development within the structural design of long-span bridges in Norwegian fjords has created a need for reformulating the calculation format and the physical quantities used to describe the properties of wind and the associated wind-induced effects on bridge decks. Parts of a new probabilistic format describing the incoming, undisturbed wind is presented. It is expected that a fixed probabilistic format will facilitate a more physically consistent and precise description of the wind conditions, which in turn increase the accuracy and considerably reduce uncertainties in wind load assessments. Because the format is probabilistic, a quantification of the level of safety and uncertainty in predicted wind loads is readily accessible. A simple buffeting response calculation demonstrates the use of probabilistic wind data in the assessment of wind loads and responses. Furthermore, vortex-induced fatigue damage is discussed in relation to probabilistic wind turbulence data and response measurements from wind tunnel tests.

An Analogy-Based Computer Tutor for Remediating Physics Misconceptions.

ERIC Educational Resources Information Center

Murray, Tom; And Others

1990-01-01

Describes an intelligent tutoring system designed to help students remedy misconceptions of physics concepts based on a teaching strategy called bridging analogies. Highlights include tutoring strategies; misconceptions in science education; the example situation network; confidence checking; formative evaluation with college students, including…

Modern hadron spectroscopy: a bridge between nuclear and particle physics.

NASA Astrophysics Data System (ADS)

Szczepaniak, A. P.

2018-05-01

In this talk I discuss aspects of hadron physics, which soon are expected to shed new light on the fundamental QCD phenomena. In the analysis of hadron reactions and their propertieds I emphasize similarities to the nuclear many body problem.

Modern hadron spectroscopy: a bridge between nuclear and particle physics

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

Szczepaniak, Adam P.

Here, in this talk I discuss aspects of hadron physics, which soon are expected to shed new light on the fundamental QCD phenomena. In the analysis of hadron reactions and their propertieds I emphasize similarities to the nuclear many body problem.

Modern hadron spectroscopy: a bridge between nuclear and particle physics

DOE PAGES

Szczepaniak, Adam P.

2018-05-01

Here, in this talk I discuss aspects of hadron physics, which soon are expected to shed new light on the fundamental QCD phenomena. In the analysis of hadron reactions and their propertieds I emphasize similarities to the nuclear many body problem.

Bridging the Conceptual Gap between Free Fall and Drag-Dominated Regimes

ERIC Educational Resources Information Center

de Obaldia, Elida; Miller, Norma; Wittel, Fred; Jaimison, George; Wallis, Kendra

2016-01-01

Some misconceptions about physics are hard to change. For example, students continue to believe that heavier objects fall faster than light ones, even after a year of physics instruction. Physics misconceptions are persistent. Light objects do fall more slowly if their size-to-weight ratio is sufficient for drag to be appreciable. Motion through a…

Results of celiac trunk stenting during fenestrated or branched aortic endografting.

PubMed

Wattez, Hélène; Martin-Gonzalez, Teresa; Lopez, Benjamin; Spear, Rafaëlle; Clough, Rachel E; Hertault, Adrien; Sobocinski, Jonathan; Haulon, Stéphan

2016-12-01

Endovascular repair of aortic aneurysms involving the visceral segment of the aorta often requires placement of a covered bridging stent in the celiac axis (CA). The median arcuate ligament (MAL) is a fibrous arch that unites the diaphragmatic crura on either side of the aortic hiatus. The ligament may compress and distort the celiac artery and result in difficult cannulation, or stenosis and occlusion of the vessel. This study evaluated the influence of the MAL compression on the technical success and the patency of the celiac artery after branched and fenestrated endovascular aortic repair. We retrospectively analyzed a cohort of consecutive patients treated electively for complex aneurysms with branched and fenestrated endovascular aortic repair between January 2007 and April 2014. All data were collected prospectively. Analysis of preoperative computed tomography angiography on a three-dimensional workstation determined the presence of MAL compression. Patency of the CA bridging stent was assessed during follow-up by computed tomography angiography and duplex ultrasound evaluation. Statistical analysis was performed to compare the outcomes of patients with MAL (MAL+) and without MAL (MAL-) compression. Of 315 patients treated for aortic disease involving the visceral segment during the study period, 113 had endografts designed with a branch (n = 57) or fenestration (n = 56) for the CA. In 45 patients (39.8%), asymptomatic compression of the CA by the MAL was depicted (MAL+). Complex endovascular techniques were required in this group to access the CA in 16 (14.2%) patients (vs none in the MAL- group; P = .003), which lead to a failed bridging stent implantation in seven patients (6.2%). Increased operative time and dose area product were observed in the MAL+ group, but this did not reach statistical significance. In the MAL+ group, no thrombosis of the CA bridging stents were observed during follow-up; an external compression of the CA bridging stent was depicted in six patients but without hemodynamic effect on duplex ultrasound imaging. In the MAL- group, one CA bridging stent occlusion occurred owing to an embolus from a cardiac source. MAL compression is associated with good celiac trunk bridging stent patency during follow-up, but with a higher rate of technical difficulties and failed bridging stent implantation during the procedure. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Bridge condition assessment based on long-term strain monitoring

NASA Astrophysics Data System (ADS)

Sun, LiMin; Sun, Shouwang

2011-04-01

In consideration of the important role that bridges play as transportation infrastructures, their safety, durability and serviceability have always been deeply concerned. Structural Health Monitoring Systems (SHMS) have been installed to many long-span bridges to provide bridge engineers with the information needed in making rational decisions for maintenance. However, SHMS also confronted bridge engineers with the challenge of efficient use of monitoring data. Thus, methodologies which are robust to random disturbance and sensitive to damage become a subject on which many researches in structural condition assessment concentrate. In this study, an innovative probabilistic approach for condition assessment of bridge structures was proposed on the basis of long-term strain monitoring on steel girder of a cable-stayed bridge. First, the methodology of damage detection in the vicinity of monitoring point using strain-based indices was investigated. Then, the composition of strain response of bridge under operational loads was analyzed. Thirdly, the influence of temperature and wind on strains was eliminated and thus strain fluctuation under vehicle loads is obtained. Finally, damage evolution assessment was carried out based on the statistical characteristics of rain-flow cycles derived from the strain fluctuation under vehicle loads. The research conducted indicates that the methodology proposed is qualified for structural condition assessment so far as the following respects are concerned: (a) capability of revealing structural deterioration; (b) immunity to the influence of environmental variation; (c) adaptability to the random characteristic exhibited by long-term monitoring data. Further examination of the applicability of the proposed methodology in aging bridge may provide a more convincing validation.

Contact area and pressure in suture bridge rotator cuff repair using knotless lateral anchors.

PubMed

Tompkins, Marc; Monchik, Keith O; Plante, Matthew J; Fleming, Braden C; Fadale, Paul D

2011-10-01

To evaluate whether the use of knotless lateral anchors in a suture bridge construct produces better contact area and pressure parameters than a suture bridge construct with standard lateral anchors that require knots or a double-row repair. The hypothesis was that knotless lateral anchors would produce better contact area and pressure parameters than the other two constructs. A total of fifteen matched pairs of cadaveric shoulders were divided into three groups. In Group 1, a suture bridge using knotless anchors for the lateral row was performed on five shoulders. A suture bridge using standard lateral row anchors that require knots was performed on the contralateral shoulders. In Group 2, suture bridge with knotless lateral row anchors was compared with double-row repair. In Group 3, suture bridge using standard lateral row anchors was compared with double-row repair. The contact conditions of the rotator cuff footprint were measured using pressure-sensitive film. There were no statistically significant differences between any of the techniques regarding contact area F(2, 15.7) = 3.09, P = 0.07 or mean contact pressure F(2, 15.1) = 2.35, P = 0.12. A post hoc power analysis suggests differences between techniques are likely less than 91-113 mm(2) for area and 0.071-0.089 N for pressure. The use of knotless anchors in the lateral row of a suture bridge repair did not increase the footprint contact area or contact pressure when compared to a suture bridge repair requiring knots laterally or to a double-row repair.

Supporting students in building interdisciplinary connections across physics and biology

NASA Astrophysics Data System (ADS)

Turpen, Chandra

2014-03-01

Our research team has been engaged in the iterative redesign of an Introductory Physics course for Life Science (IPLS) majors to explicitly bridge biology and physics in ways that are authentic to the disciplines. Our interdisciplinary course provides students opportunities to examine how modeling decisions (e.g. knowing when and how to use different concepts, identifying implicit assumptions, making and justifying assumptions) may differ depending on canonical disciplinary aims and interests. Our focus on developing students' interdisciplinary reasoning skills requires 1) shifting course topics to focus on core ideas that span the disciplines, 2) shifting epistemological expectations, and 3) foregrounding typically tacit disciplinary assumptions. In working to build an authentic interdisciplinary course that bridges physics and biology, we pay careful attention to supporting students in constructing these bridges. This course has been shown to have important impacts: a) students seek meaningful connections between the disciplines, b) students perceive relevance and utility of ideas from different disciplines, and c) students reconcile challenging disciplinary ideas. Although our focus has been on building interdisciplinary coherence, we have succeeded in maintaining strong student learning gains on fundamental physics concepts and allowed students to deepen their understanding of challenging concepts in thermodynamics. This presentation will describe the shifts in course content and the modern pedagogical approaches that have been integrated into the course, and provide an overview of key research results from this project. These results may aid physicists in reconsidering how they can meaningfully reach life-science students. This work is supported by NSF-TUES DUE 11-22818, the HHMI NEXUS grant, and a NSF Graduate Research Fellowship (DGE 0750616).

Present-day Galaxy Evolution through Baryon Flows in the Circumgalactic Medium of the Galactic-Magellanic System

NASA Astrophysics Data System (ADS)

Barger, Kathleen Ann

Galaxy evolution is governed by an intricate ballet of gas flows. To sustain star formation over many billions of years, more gas must inflow than outflow. Although numerous gas clouds surround the Milky Way, their attributes, origins, destinations, and responses to their surroundings need thorough investigation on an individual basis to realize how the entire population affects Galactic evolution. This dissertation hones in on two circumgalactic gas structures near the Milky Way: Complex A and the Magellanic Bridge. Complex A is an elongated gas structure that is traversing the hot Halo of the Milky Way, plummeting towards the Galaxy's disk. The Magellanic Bridge is a bridge of gas and stars that connects the Magellanic Clouds, created by galaxy interactions. In this thesis, I present the results of the highest sensitivity and kinematically resolved Halpha emission-line survey of Complex A and Halpha, [S II], and [N II] surveys of the Magellanic Bridge using the Wisconsin Halpha Mapper to explore their properties, surroundings, origins, and fates to unravel how circumgalactic structures influence galaxy evolution. I find that the observational properties of Complex A closely match with radiative transfer model predictions of a cloud ionized by the Milky Way and extragalactic background, implying a 5% escape fraction of ionizing photons from the Galactic disk. The multiline observations and modeling place the cloud's metallicity below solar. These results combined with other studies suggests the cloud has an intergalactic medium origin. I find that the global distribution of the warm ionized gas traces the neutral gas in the Magellanic Bridge. These observations place the ionized gas mass between (0.7 -- 1.6) x 108 solar masses, implying an ionization fraction of 25 -- 33% and a 5% maximum escape fraction of ionizing photons from the Magellanic Clouds. The line ratios reveal that the physical state of the the SMC-Tail and the LMC-Bridge interface regions differ from the Magellanic Bridge. The multiple component structure and line ratios reveal that at least two coherent structures with different physical properties exist throughout the Bridge.

A case of survival of extreme vertical impact in seated position.

DOT National Transportation Integrated Search

1962-10-01

Physical, biophysical, and medical data are presented concerning the case of a 20-year-old male of excellent physical condition who jumped from the Golden Gate Bridge in San Francisco, surviving for ten days a free-fall deceleration in the seated pos...

Building bridges between the physical and biological sciences.

PubMed

Ninham, B W; Boström, M

2005-12-16

This paper attempts to identify major conceptual issues that have inhibited the application of physical chemistry to problems in the biological sciences. We will trace out where theories went wrong, how to repair the present foundations, and discuss current progress toward building a better dialogue.

Sociology of Sport.

ERIC Educational Resources Information Center

Greendorfer, Susan L.

1985-01-01

The author describes the issues which created the schism between physical education and sociology. If the subdiscipline of sports sociology is to survive, these misunderstandings must be erased. Current investigations of relevant topics are of interest to both physical educators and coaches and could begin to bridge the gap. (MT)

Rethinking Physics for Biologists: A design-based research approach

NASA Astrophysics Data System (ADS)

Sawtelle, Vashti

2015-03-01

Biology majors at the University of Maryland are required to take courses in biology, chemistry, and physics - but they often see these courses as disconnected. Over the past three years the NEXUS/Physics course has been working to develop an interdisciplinary learning environment that bridges the disciplinary domains of biology and physics. Across the three years we have gone from teaching in a small class with one instructor to teaching in a large lecture hall with multiple instructors. We have used a design-based research approach to support critical reflection of the course at multiple-time scales. In this presentation I will detail our process of collecting systematic data, listening to and valuing students' reasoning, and bridging diverse perspectives led. I will demonstrate how this process led to improved curricular design, refined assessment objectives, and new design heuristics. This work is supported by NSF-TUES DUE 11-22818, the HHMI NEXUS grant, and a NSF Graduate Research Fellowship (DGE 0750616).

Hydraulic modeling of mussel habitat at a bridge-replacement site, Allegheny River, Pennsylvania, USA

USGS Publications Warehouse

Fulton, John W.; Wagner, Chad R.; Rogers, Megan E.; Zimmerman, Gregory F.

2010-01-01

Based on the statistical targets established, the hydraulic model results suggest that an additional 2428 m2 or a 30-percent increase in suitable mussel habitat could be generated at the replacement-bridge site when compared to the baseline condition associated with the existing bridge at that same location. The study did not address the influences of substrate, acid mine drainage, sediment loads from tributaries, and surface-water/ground-water exchange on mussel habitat. Future studies could include methods for quantifying (1) channel–substrate composition and distribution using tools such as hydroacoustic echosounders specifically designed and calibrated to identify bed composition and mussel populations, (2) surface-water and ground-water interactions, and (3) a high-streamflow event.

Clinical study of Mineral Trioxide Aggregate in primary molars. Comparison between Grey and White MTA--a long term follow-up (84 months).

PubMed

Cardoso-Silva, Cristina; Barbería, Elena; Maroto, Myriam; García-Godoy, Franklin

2011-02-01

The aim of the present study was to conduct a clinical and radiographic long-term evaluation of pulpotomy in temporary molars performed with Grey and White Mineral Trioxide Aggregate (MTA) and compare the results of Grey and White MTA pulpotomies in a sample of 233 primary molars with a maximum follow-up period of 84 months. The sample was selected from patients treated at the Department of Pediatric Dentistry, Faculty of Dentistry, Complutense University of Madrid, Spain. This prospective study included first and second primary molars treated with pulpotomy with Grey or White MTA, controlled for a maximum follow-up period of 84 months. Statistical analysis of clinical and radiographic findings was completed using ANOVA (P<0.05). Follow-up evaluations, performed every 6 months, revealed that only 2 molars treated with White MTA presented abscess and pathological mobility. Radiographic examination of the 210 molars revealed unfavourable pulp response in only 6 molars (internal or furcation root resorption), without statistically significant differences between Grey and White MTA. Two radiological findings were noticed: dentine bridge formation and partial or total root canal stenosis. Grey MTA induced a higher percentage of dentine bridges with statistically significant differences (P<0.05), and a higher percentage of pulp canal stenosis, without a statistically significant difference. Grey and White MTA presented high levels of clinical and radiographic success. Although the present study showed evidence of a very good biologic response with both types of MTA, Grey MTA showed significantly higher number of dentine bridge formation than White MTA. Copyright © 2010 Elsevier Ltd. All rights reserved.

Elementary Preservice Teachers' Reasoning about Modeling a "Family Factory" with TinkerPlots--A Pilot Study

ERIC Educational Resources Information Center

Biehler, Rolf; Frischemeier, Daniel; Podworny, Susanne

2017-01-01

Connecting data and chance is fundamental in statistics curricula. The use of software like TinkerPlots can bridge both worlds because the TinkerPlots Sampler supports learners in expressive modeling. We conducted a study with elementary preservice teachers with a basic university education in statistics. They were asked to set up and evaluate…

A statistical mechanics approach to autopoietic immune networks

NASA Astrophysics Data System (ADS)

Barra, Adriano; Agliari, Elena

2010-07-01

In this work we aim to bridge theoretical immunology and disordered statistical mechanics. We introduce a model for the behavior of B-cells which naturally merges the clonal selection theory and the autopoietic network theory as a whole. From the analysis of its features we recover several basic phenomena such as low-dose tolerance, dynamical memory of antigens and self/non-self discrimination.

Self-efficacy, planning, and preparatory behaviours as joint predictors of physical activity: A conditional process analysis.

PubMed

Barz, Milena; Lange, Daniela; Parschau, Linda; Lonsdale, Chris; Knoll, Nina; Schwarzer, Ralf

2016-01-01

Planning can bridge the gap between intentions and action, but what bridges the gap between planning and action? This study helps to answer the question by disentangling the interrelationships between self-efficacy, planning and preparatory behaviours in predicting physical activity. Preparatory behaviours are tested as a working mechanism of planning. Moreover, it is tested whether the utility of preparatory behaviours depends on an individual's level of self-efficacy. A survey assessed planning, self-efficacy and preparatory behaviours for physical activity. Adults (N = 166) provided data at two measurement points. In a longitudinal model, preparatory behaviours were specified as a mediator between planning and physical activity. Self-efficacy was specified as a possible moderator at two points in the model. Preparatory behaviours mediated the relationship between planning and physical activity. An interaction between self-efficacy and preparatory behaviours on physical activity was found, indicating that individuals with low self-efficacy beliefs were more active if they engaged more frequently in preparatory behaviours. Planning seems to stimulate preparatory behaviours, which in turn make future physical activity more likely. Furthermore, as performing preparatory behaviours represent a step forward towards the enactment of behavioural goals, preparatory behaviours may be particular beneficial for individuals afflicted by self-doubts regarding physical activity.

LEM-3 is a midbody-tethered DNA nuclease that resolves chromatin bridges during late mitosis.

PubMed

Hong, Ye; Sonneville, Remi; Wang, Bin; Scheidt, Viktor; Meier, Bettina; Woglar, Alexander; Demetriou, Sarah; Labib, Karim; Jantsch, Verena; Gartner, Anton

2018-02-20

Faithful chromosome segregation and genome maintenance requires the removal of all DNA bridges that physically link chromosomes before cells divide. Using C. elegans embryos we show that the LEM-3/Ankle1 nuclease defines a previously undescribed genome integrity mechanism by processing DNA bridges right before cells divide. LEM-3 acts at the midbody, the structure where abscission occurs at the end of cytokinesis. LEM-3 localization depends on factors needed for midbody assembly, and LEM-3 accumulation is increased and prolonged when chromatin bridges are trapped at the cleavage plane. LEM-3 locally processes chromatin bridges that arise from incomplete DNA replication, unresolved recombination intermediates, or the perturbance of chromosome structure. Proper LEM-3 midbody localization and function is regulated by AIR-2/Aurora B kinase. Strikingly, LEM-3 acts cooperatively with the BRC-1/BRCA1 homologous recombination factor to promote genome integrity. These findings provide a molecular basis for the suspected role of the LEM-3 orthologue Ankle1 in human breast cancer.

Relationship between ancient bridges and population dynamics in the lower Yangtze River Basin, China.

PubMed

Zhao, Yang; Jia, Xin; Lee, Harry F; Zhao, Hongqiang; Cai, Shuliang; Huang, Xianjin

2017-01-01

It has been suggested that population growth dynamics may be revealed by the geographic distribution and the physical structure of ancient bridges. Yet, this relationship has not been empirically verified. In this study, we applied the archaeological records for ancient bridges to reveal the population growth dynamics in the lower Yangtze River Basin in late imperial China. We investigated 89 ancient bridges in Yixing that were built during the Ming and Qing dynasties (AD1368-1911). Global Position System information and structure (length, width, and span) of those bridges was measured during our field investigations. Their distribution density was calculated by ArcGIS. The historical socio-economic dynamics of Yixing was inferred from the distribution and structure of ancient bridges. Based on the above information, the population growth dynamics in Yixing was projected. Our results show that 77 bridges were built in Yixing during the Qing dynasty, which is 6.41 times more than the number built during the Ming dynasty. In the Ming dynasty, bridges were built on pivotal routes; in the Qing dynasty, bridges were scattered across various places. Over the period, the density distribution of bridges shifted northwestward, while the average length and width of bridges decreased. The increasing number of bridges corresponded to population growth, largely attributable to massive clan migration from northern China during the Little Ice Age. The shift in the density distribution of bridges corresponded to the formation of settlements of large clans and the blossoming of Yixing Teapot handicrafts. The scattering and the reduction in average length and width of bridges was due to the dispersal of population and the associated formation of small settlements in the latter period. Our approach is innovative and robust, and could be employed to recover long-term historical population growth dynamics in other parts of China.

Relationship between ancient bridges and population dynamics in the lower Yangtze River Basin, China

PubMed Central

Zhao, Yang; Lee, Harry F.; Zhao, Hongqiang; Cai, Shuliang; Huang, Xianjin

2017-01-01

It has been suggested that population growth dynamics may be revealed by the geographic distribution and the physical structure of ancient bridges. Yet, this relationship has not been empirically verified. In this study, we applied the archaeological records for ancient bridges to reveal the population growth dynamics in the lower Yangtze River Basin in late imperial China. We investigated 89 ancient bridges in Yixing that were built during the Ming and Qing dynasties (AD1368–1911). Global Position System information and structure (length, width, and span) of those bridges was measured during our field investigations. Their distribution density was calculated by ArcGIS. The historical socio-economic dynamics of Yixing was inferred from the distribution and structure of ancient bridges. Based on the above information, the population growth dynamics in Yixing was projected. Our results show that 77 bridges were built in Yixing during the Qing dynasty, which is 6.41 times more than the number built during the Ming dynasty. In the Ming dynasty, bridges were built on pivotal routes; in the Qing dynasty, bridges were scattered across various places. Over the period, the density distribution of bridges shifted northwestward, while the average length and width of bridges decreased. The increasing number of bridges corresponded to population growth, largely attributable to massive clan migration from northern China during the Little Ice Age. The shift in the density distribution of bridges corresponded to the formation of settlements of large clans and the blossoming of Yixing Teapot handicrafts. The scattering and the reduction in average length and width of bridges was due to the dispersal of population and the associated formation of small settlements in the latter period. Our approach is innovative and robust, and could be employed to recover long-term historical population growth dynamics in other parts of China. PMID:28792976

Bridge esthetic guidelines.

DOT National Transportation Integrated Search

1975-01-01

As esthetics is not an exact science, differences of opinion occur, even between experts; however, studies had found that in most cases there were statistical preferences. These preferences are presented. For the convenience of the designer, a format...

The influence of package size and flute type of corrugated boxes on load bridging in unit loads

Treesearch

Jonghun Park; Laszlo Horvath; Marshall S. White; Samantha Phanthanousy; Philip Araman; Robert J. Bush

2017-01-01

Shipping pallets often are designed with the assumption that the payload carried is flexible and uniformly distributed on the pallet surface. However, packages on the pallet can act as a series of discrete loads, and the physical interactions among the packages can add stiffness to the pallet/load combination. The term ‘load bridging’ has been used to describe this...

Combined collapse by bridging and self-adhesion in a prototypical polymer model inspired by the bacterial nucleoid

NASA Astrophysics Data System (ADS)

Scolari, Vittore F.; Cosentino Lagomarsino, Marco

Recent experimental results suggest that the E. coli chromosome feels a self-attracting interaction of osmotic origin, and is condensed in foci by bridging interactions. Motivated by these findings, we explore a generic modeling framework combining solely these two ingredients, in order to characterize their joint effects. Specifically, we study a simple polymer physics computational model with weak ubiquitous short-ranged self attraction and stronger sparse bridging interactions. Combining theoretical arguments and simulations, we study the general phenomenology of polymer collapse induced by these dual contributions, in the case of regularly-spaced bridging. Our results distinguish a regime of classical Flory-like coil-globule collapse dictated by the interplay of excluded volume and attractive energy and a switch-like collapse where bridging interaction compete with entropy loss terms from the looped arms of a star-like rosette. Additionally, we show that bridging can induce stable compartmentalized domains. In these configurations, different "cores" of bridging proteins are kept separated by star-like polymer loops in an entropically favorable multi-domain configuration, with a mechanism that parallels micellar polysoaps. Such compartmentalized domains are stable, and do not need any intra-specific interactions driving their segregation. Domains can be stable also in presence of uniform attraction, as long as the uniform collapse is above its theta point.

Statistical Analyses of High-Resolution Aircraft and Satellite Observations of Sea Ice: Applications for Improving Model Simulations

NASA Astrophysics Data System (ADS)

Farrell, S. L.; Kurtz, N. T.; Richter-Menge, J.; Harbeck, J. P.; Onana, V.

2012-12-01

Satellite-derived estimates of ice thickness and observations of ice extent over the last decade point to a downward trend in the basin-scale ice volume of the Arctic Ocean. This loss has broad-ranging impacts on the regional climate and ecosystems, as well as implications for regional infrastructure, marine navigation, national security, and resource exploration. New observational datasets at small spatial and temporal scales are now required to improve our understanding of physical processes occurring within the ice pack and advance parameterizations in the next generation of numerical sea-ice models. High-resolution airborne and satellite observations of the sea ice are now available at meter-scale resolution or better that provide new details on the properties and morphology of the ice pack across basin scales. For example the NASA IceBridge airborne campaign routinely surveys the sea ice of the Arctic and Southern Oceans with an advanced sensor suite including laser and radar altimeters and digital cameras that together provide high-resolution measurements of sea ice freeboard, thickness, snow depth and lead distribution. Here we present statistical analyses of the ice pack primarily derived from the following IceBridge instruments: the Digital Mapping System (DMS), a nadir-looking, high-resolution digital camera; the Airborne Topographic Mapper, a scanning lidar; and the University of Kansas snow radar, a novel instrument designed to estimate snow depth on sea ice. Together these instruments provide data from which a wide range of sea ice properties may be derived. We provide statistics on lead distribution and spacing, lead width and area, floe size and distance between floes, as well as ridge height, frequency and distribution. The goals of this study are to (i) identify unique statistics that can be used to describe the characteristics of specific ice regions, for example first-year/multi-year ice, diffuse ice edge/consolidated ice pack, and convergent/divergent ice zones, (ii) provide datasets that support enhanced parameterizations in numerical models as well as model initialization and validation, (iii) parameters of interest to Arctic stakeholders for marine navigation and ice engineering studies, and (iv) statistics that support algorithm development for the next-generation of airborne and satellite altimeters, including NASA's ICESat-2 mission. We describe the potential contribution our results can make towards the improvement of coupled ice-ocean numerical models, and discuss how data synthesis and integration with high-resolution models may improve our understanding of sea ice variability and our capabilities in predicting the future state of the ice pack.

Remediating Physics Misconceptions Using an Analogy-Based Computer Tutor. Draft.

ERIC Educational Resources Information Center

Murray, Tom; And Others

Described is a computer tutor designed to help students gain a qualitative understanding of important physics concepts. The tutor simulates a teaching strategy called "bridging analogies" that previous research has demonstrated to be successful in one-on-one tutoring and written explanation studies. The strategy is designed to remedy…

Experiments with Helium-Filled Balloons

ERIC Educational Resources Information Center

Zable, Anthony C.

2010-01-01

The concepts of Newtonian mechanics, fluids, and ideal gas law physics are often treated as separate and isolated topics in the typical introductory college-level physics course, especially in the laboratory setting. To bridge these subjects, a simple experiment was developed that utilizes computer-based data acquisition sensors and a digital gram…

Innovative Uses of Video Analysis

ERIC Educational Resources Information Center

Brown, Douglas; Cox, Anne J.

2009-01-01

The value of video analysis in physics education is well established, and both commercial and free educational video analysis programs are readily available. The video format is familiar to students, contains a wealth of spatial and temporal data, and provides a bridge between direct observations and abstract representations of physical phenomena.…

Teaching Game Sense in Soccer

ERIC Educational Resources Information Center

Pill, Shane

2012-01-01

"Game sense" is a sport-specific iteration of the teaching games for understanding model, designed to balance physical development of motor skill and fitness with the development of game understanding. Game sense can foster a shared vision for sport learning that bridges school physical education and community sport. This article explains how to…

Statistical Representations of Track Geometry : Volume I, Text.

DOT National Transportation Integrated Search

1980-03-31

Mathematical representations of railroad track geometry variations are derived from time series analyses of track measurements. Since the majority of track is free of anomalies (turnouts, crossings, bridges, etc.), representation of anomaly-free trac...

The Bridge from Teacher Preparation to Beginning Teacher: Helping NESB Beginning Teachers Enter a Community of Teaching Practice

ERIC Educational Resources Information Center

McCluskey, Kerryn

2009-01-01

Australia is a multicultural country. In the ten years to November 2007, there were 647,000 migrants who entered Australia (Australian Bureau of Statistics, 2008). Of these migrants 76% were born in countries other than those identified by the Australian Bureau of Statistics (ABS, 2008) as main English speaking countries (the United Kingdom, The…

Tie Goes to the Runner: The Physics and Psychology of a Close Play

NASA Astrophysics Data System (ADS)

Starling, David J.; Starling, Sarah J.

2017-04-01

Since physics is often a service course for college students, it is important to incorporate everyday examples in the curriculum that inspire students of diverse backgrounds and interests. In this regard, baseball has been a workhorse for the physics classroom for a long time, taking the form of demonstrations and example problems. Here, we discuss how baseball can help bridge the physical and social sciences in an introductory physics course by analyzing a close play at first base.

The collection of clear-water contraction and abutment scour data at selected bridge sites in the coastal plain and piedmont of South Carolina

USGS Publications Warehouse

Benedict, Stephen T.; Caldwell, Andy W.; Edited by Abt, S. R. and others

1998-01-01

Clear-water contraction and abutment scour data were collected at 128 bridge sites in South Carolina. In the sandy soils of the Coastal Plain, clear-water-scour data were collected at 63 sites (scour depths ranged from 0.4 to 7.2 meters.) In the clayey soils of the Piedmont, clear-water-scour data were collected at 47 sites (scour depths ranged from 0 to 1.4 meters.) In the sandy, clayey soils of the Piedmont, clear-water-scour data were collected at 18 sites (scour depths ranged from 0.9 to 5.5 meters.) The field data are to be compiled into a data base that will include bridge age; basin, soil and hydraulic characteristics; and theoretical scour data. The data are planned to be statistically analyzed for significant relations that may help explain and (or) predict maximum scour depths at bridges in South Carolina.

Study on Standard Fatigue Vehicle Load Model

NASA Astrophysics Data System (ADS)

Huang, H. Y.; Zhang, J. P.; Li, Y. H.

2018-02-01

Based on the measured data of truck from three artery expressways in Guangdong Province, the statistical analysis of truck weight was conducted according to axle number. The standard fatigue vehicle model applied to industrial areas in the middle and late was obtained, which adopted equivalence damage principle, Miner linear accumulation law, water discharge method and damage ratio theory. Compared with the fatigue vehicle model Specified by the current bridge design code, the proposed model has better applicability. It is of certain reference value for the fatigue design of bridge in China.

JOSPT Experiences Tremendous Growth, Change in 14 Years With Editor-in-Chief Simoneau in Charge.

PubMed

Nyland, John A

2015-12-01

As Editor-in-Chief, Dr Guy G. Simoneau and his editorial board have taken JOSPT from an acceptable US-based journal to a highly influential worldwide force behind contemporary orthopaedic and sports physical therapy research and practice. Today, the bridge Dr Simoneau constructed spans the orthopaedic and sports physical therapy globe for the betterment of clinical practice and research. His work fully supports JOSPT's latest strategic plan to provide value-added knowledge translation, develop a broader authorship and readership, increase global marketing of the JOSPT brand, and expand current relationships to new partners and stakeholders. The bridge places JOSPT on very firm footing, tying its rich history to the promise of an exciting and successful future.

Bridging the Resolution Gap in Structural Modeling of 3D Genome Organization

PubMed Central

Marti-Renom, Marc A.; Mirny, Leonid A.

2011-01-01

Over the last decade, and especially after the advent of fluorescent in situ hybridization imaging and chromosome conformation capture methods, the availability of experimental data on genome three-dimensional organization has dramatically increased. We now have access to unprecedented details of how genomes organize within the interphase nucleus. Development of new computational approaches to leverage this data has already resulted in the first three-dimensional structures of genomic domains and genomes. Such approaches expand our knowledge of the chromatin folding principles, which has been classically studied using polymer physics and molecular simulations. Our outlook describes computational approaches for integrating experimental data with polymer physics, thereby bridging the resolution gap for structural determination of genomes and genomic domains. PMID:21779160

Super-bridges suspended over carbon nanotube cables

NASA Astrophysics Data System (ADS)

Carpinteri, Alberto; Pugno, Nicola M.

2008-11-01

In this paper the new concept of 'super-bridges', i.e. kilometre-long bridges suspended over carbon nanotube cables, is introduced. The analysis shows that the use of realistic (thus defective) carbon nanotube bundles as suspension cables can enlarge the current limit main span by a factor of ~3. Too large compliance and dynamic self-excited resonances could be avoided by additional strands, rendering the super-bridge anchored as a spider's cobweb. As an example, we have computed the limit main spans of the current existing 19 suspended-deck bridges longer than 1 km assuming them to have substituted their cables with carbon nanotube bundles (thus maintaining the same geometry, with the exception of the length) finding spans of up to ~6.3 km. We thus suggest that the design of the Messina bridge in Italy, which would require a main span of ~3.3 km, could benefit from the use of carbon nanotube bundles. We believe that their use represents a feasible and economically convenient solution. The plausibility of these affirmations is confirmed by a statistical analysis of the existing 100 longest suspended bridges, which follow a Zipf's law with an exponent of 1.1615: we have found a Moore-like (i.e. exponential) law, in which the doubling of the capacity (here the main span) per year is substituted by the factor 1.0138. Such a law predicts that the realization of the Messina bridge using conventional materials will only occur around the middle of the present century, whereas it could be expected in the near future if carbon nanotube bundles were used. A simple cost analysis concludes the paper.

CF60 Concrete Composition Design and Application on Fudiankou Xijiang Super Large Bridge

NASA Astrophysics Data System (ADS)

Qiu, Yi Mei; Wen, Sen Yuan; Chen, Jun Xiang

2018-06-01

Guangxi Wuzhou City Ring Road Fudiankou Xijiang super large bridge CF60 concrete is a new multi-phase composite high-performance concrete, this paper for the Fudiankou Xijiang bridge structure and characteristics of the project, in accordance with the principle of local materials and technical specification requirements, combined with the site conditions of CF60 engineering high performance concrete component materials, proportion and the technical performance, quantify the main physical and mechanical performance index. Analysis main influencing factors of the technical indicators, reasonable adjustment of concrete mix design parameters, and the use of technical means of admixture and multi-function composite admixture of concrete, obtain the optimal proportion of good work, process, mechanical properties stability and durability of engineering properties, recommend and verification of concrete mix; to explore the CF60 high performance concrete Soil in the Fudiankou Xijiang bridge application technology, detection and tracking the quality of concrete construction, concrete structure during the construction of the key technology and control points is proposed, evaluation of CF60 high performance concrete in the actual engineering application effect and benefit to ensure engineering quality of bridge structure and service life, and super long span bridge engineering construction to provide basis and reference.

A Conversation with Lee Alvin DuBridge - Part I

NASA Astrophysics Data System (ADS)

Goodstein, Judith R.

Physicist Lee A. DuBridge became president of the California Institute of Technology in 1946. In this interview he recalls the immediate problems he faced, including his dealings with Robert A. Millikan, whom he replaced as chief administrator of the institute; institute financing and inadequate salaries. DuBridge also talks about the advent of federal support for peacetime science and Millikan's distaste for it; his close working relationship with Robert F. Bacher, who came to the institute in 1949 as chairman of the Division of Physics, Mathematics, and Astronomy; his recollections of the meteorologist Irving P. Krick, the physicist Alexander Goetz, and the chemist Linus Pauling; and his attempts to build up the Humanities Division.

Local sediment scour model tests for the Woodrow Wilson Bridge piers

USGS Publications Warehouse

Sheppard, D.M.; Jones, J.S.; Odeh, M.; Glasser, T.

2004-01-01

The Woodrow Wilson Bridge on I-495 over the Potomac River in Prince Georges County, Maryland is being replaced. Physical local scour model studies for the proposed piers for the new bridge were performed in order to help establish design scour depths. Tests were conducted in two different flumes, one in the USGS-BRD Conte Research Center in Turners Falls, Massachusetts and one in the FHWA Turner Fairbanks Laboratory in McLean, Virginia. Due to space limitations in this publication only the tests conducted in the USGS flume are presented in this paper. Two different pier designs were tested. One of the piers was also tested with two different diameter dolphin systems. Copyright ASCE 2004.

Ergonomics of bridge employment.

PubMed

Mohamed, Mokdad

2012-01-01

In many countries of the world, retirement is mandatory at the age at which persons who hold certain jobs or offices are required by employment law to leave their employment, or retire (60 to 65 years). Typically, this is justified by the argument that certain occupations are either too dangerous or require high levels of physical skills and mental work. Every worker has to leave the workforce at that age. However, starting from the last two decades of the last century, it is observed that retirees live more years in retirement than ever before. This relatively long retirement as well as retirees' body fitness made many of them engage in new jobs which are either similar to their career jobs, or completely different from them. In this new type of employment which is called "bridge employment', the retired worker may spend more than ten years. But, to what extent these new jobs are fitted to the aged worker? Considering that experiencing any type of event increases the risk of worse health outcomes over time, bridge employment should be ergonomically designed if it is to fit the aged worker characteristics (physical, mental and affective).

Longevity of anterior resin-bonded bridges: survival rates of two tooth preparation designs.

PubMed

Abuzar, M; Locke, J; Burt, G; Clausen, G; Escobar, K

2018-04-16

Significant developments have occurred in the design of resin-bonded bridges (RBB) over the past two decades. They are commonly used as an alternative treatment option for a single missing tooth. The longevity of these bridges needs to be further investigated to evaluate long-term outcomes for this option to remain relevant. A cohort of patients who received anterior resin-bonded bridges (ARBB) over two decades was studied retrospectively. Longevity of 206 ARBB was assessed using Kaplan-Meier probability estimates. The two modified tooth preparation designs investigated were: (A) mesial and distal vertical grooves only; and (B) one proximal groove adjacent to the pontic and two palatal grooves. Age and gender of the patient cohort were also recorded. Overall survival rate of ARBB was 98% at 5 years, 97.2% at 10 years, and 95.1% from 12 years till 21 years. Survival curves showed minor differences when compared for the two designs, age groups and gender of ARBB recipients. Differences in the proportion of surviving bridges for design A (95.96%) and design B (98.13%) were not statistically significant (Fisher's exact test). Anterior RBB with described tooth preparation designs demonstrate a high survival rate. © 2018 Australian Dental Association.

Full-scale measurements and system identification on Sutong cable-stayed bridge during Typhoon Fung-Wong.

PubMed

Wang, Hao; Tao, Tianyou; Guo, Tong; Li, Jian; Li, Aiqun

2014-01-01

The structural health monitoring system (SHMS) provides an effective tool to conduct full-scale measurements on existing bridges for essential research on bridge wind engineering. In July 2008, Typhoon Fung-Wong lashed China and hit Sutong cable-stayed bridge (SCB) in China. During typhoon period, full-scale measurements were conducted to record the wind data and the structural vibration responses were collected by the SHMS installed on SCB. Based on the statistical method and the spectral analysis technique, the measured data are analyzed to obtain the typical parameters and characteristics. Furthermore, this paper analyzed the measured structural vibration responses and indicated the vibration characteristics of the stay cable and the deck, the relationship between structural vibrations and wind speed, the comparison of upstream and downstream cable vibrations, the effectiveness of cable dampers, and so forth. Considering the significance of damping ratio in vibration mitigation, the modal damping ratios of the SCB are identified based on the Hilbert-Huang transform (HHT) combined with the random decrement technique (RDT). The analysis results can be used to validate the current dynamic characteristic analysis methods, buffeting calculation methods, and wind tunnel test results of the long-span cable-stayed bridges.

Full-Scale Measurements and System Identification on Sutong Cable-Stayed Bridge during Typhoon Fung-Wong

PubMed Central

Tao, Tianyou; Li, Aiqun

2014-01-01

The structural health monitoring system (SHMS) provides an effective tool to conduct full-scale measurements on existing bridges for essential research on bridge wind engineering. In July 2008, Typhoon Fung-Wong lashed China and hit Sutong cable-stayed bridge (SCB) in China. During typhoon period, full-scale measurements were conducted to record the wind data and the structural vibration responses were collected by the SHMS installed on SCB. Based on the statistical method and the spectral analysis technique, the measured data are analyzed to obtain the typical parameters and characteristics. Furthermore, this paper analyzed the measured structural vibration responses and indicated the vibration characteristics of the stay cable and the deck, the relationship between structural vibrations and wind speed, the comparison of upstream and downstream cable vibrations, the effectiveness of cable dampers, and so forth. Considering the significance of damping ratio in vibration mitigation, the modal damping ratios of the SCB are identified based on the Hilbert-Huang transform (HHT) combined with the random decrement technique (RDT). The analysis results can be used to validate the current dynamic characteristic analysis methods, buffeting calculation methods, and wind tunnel test results of the long-span cable-stayed bridges. PMID:24995367

Building Bridges to Diversity in Graduate Physics & Astronomy: The Fisk-Vanderbilt Masters-to-PhD Bridge Program

NASA Astrophysics Data System (ADS)

Stassun, Keivan G.

2006-12-01

We describe the Fisk-Vanderbilt Masters-to-PhD Bridge program as a successful model for effective partnerships with minority-serving institutions toward significantly broadening the participation of underrepresented groups in the physical sciences. The program couples targeted recruitment with active retention strategies, and is built upon a clearly defined structure that is flexible enough to address individual student needs while maintaining clearly communicated baseline standards for student performance. A key precept of the program’s philosophy is to eliminate passivity in student mentoring; students are deliberately groomed to successfully transition into the PhD program through active involvement in research experiences with future PhD advisers, coursework that demonstrates competency in core PhD subject areas, and frequent interactions with joint mentoring committees. This approach allows student progress and performance to be monitored and evaluated in a more holistic manner than usually afforded by limited metrics such as standardized tests. Since its inception in 2004, the program has attracted a total of 18 underrepresented students, with a retention rate of 90%. Recent research indicates that minority students are nearly twice as likely as non-minority students to seek a Masters degree en route to the PhD. In essence, the Bridge program described here builds upon this increasingly important pathway, with a dedicated mentoring process designed to ensure that the Masters-to-PhD transition is a successful one.

Bridge Health Monitoring Using a Machine Learning Strategy

DOT National Transportation Integrated Search

2017-01-01

The goal of this project was to cast the SHM problem within a statistical pattern recognition framework. Techniques borrowed from speaker recognition, particularly speaker verification, were used as this discipline deals with problems very similar to...

From Random Walks to Brownian Motion, from Diffusion to Entropy: Statistical Principles in Introductory Physics

NASA Astrophysics Data System (ADS)

Reeves, Mark

2014-03-01

Entropy changes underlie the physics that dominates biological interactions. Indeed, introductory biology courses often begin with an exploration of the qualities of water that are important to living systems. However, one idea that is not explicitly addressed in most introductory physics or biology textbooks is dominant contribution of the entropy in driving important biological processes towards equilibrium. From diffusion to cell-membrane formation, to electrostatic binding in protein folding, to the functioning of nerve cells, entropic effects often act to counterbalance deterministic forces such as electrostatic attraction and in so doing, allow for effective molecular signaling. A small group of biology, biophysics and computer science faculty have worked together for the past five years to develop curricular modules (based on SCALEUP pedagogy) that enable students to create models of stochastic and deterministic processes. Our students are first-year engineering and science students in the calculus-based physics course and they are not expected to know biology beyond the high-school level. In our class, they learn to reduce seemingly complex biological processes and structures to be described by tractable models that include deterministic processes and simple probabilistic inference. The students test these models in simulations and in laboratory experiments that are biologically relevant. The students are challenged to bridge the gap between statistical parameterization of their data (mean and standard deviation) and simple model-building by inference. This allows the students to quantitatively describe realistic cellular processes such as diffusion, ionic transport, and ligand-receptor binding. Moreover, the students confront ``random'' forces and traditional forces in problems, simulations, and in laboratory exploration throughout the year-long course as they move from traditional kinematics through thermodynamics to electrostatic interactions. This talk will present a number of these exercises, with particular focus on the hands-on experiments done by the students, and will give examples of the tangible material that our students work with throughout the two-semester sequence of their course on introductory physics with a bio focus. Supported by NSF DUE.

Dynamic characterization and damage detection in the I-40 bridge over the Rio Grande

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

Farrar, C.R.; Baker, W.E.; Bell, T.M.

In the 1960`s and 1970`s over 2500 bridges were built in the U.S. with a design similar to those on Interstate 40 over the Rio Grande in Albuquerque, New Mexico. These bridges were built without structural redundancy and typically have only two plate girders carrying the entire dead and live loads. Failure of either girder is assumed to produce catastrophic failure of the bridge, hence these bridges are referred to as fracture-critical bridges. The Federal Highway Administration (FHWA) and the National Science Foundation (NSF) have provided funds to New Mexico State University (NMSU) through the New Mexico State Highway andmore » Transportation Department (NMSH&TD) and The Alliance For Transportation Research (ATR) for evaluation and testing of the existing fracture critical bridges over the Rio Grande. Because the 1-40 bridges over the Rio Grande were to be razed during the summer of 1993, the investigators were able to introduce simulated fatigue cracks, similar to those observed in the field, into the structure in order to test various damage identification methods and to observe the changes in load paths through the structure caused by the cracking. To support this research effort, NMSU contracted Los Alamos National Laboratory (LANL) to perform experimental modal analyses, and to develop experimentally verified numerical models of the bridge. Scientists from the LANL`s Condensed Matter and Thermal Physics Group (P-10) applied state-of-the-art sensors and data acquisition software to the modal tests. Engineers from the LANL`s Advanced Engineering Technology Group (MEE-13) conducted ambient and forced vibration tests to verify detailed and simplified finite element models of the bridge. Forced vibration testing was done in conjunction with engineers from Sandia National Laboratory (SNL) who provided and operated a hydraulic shaker.« less

Are strategies in physics discrete? A remote controlled investigation

NASA Astrophysics Data System (ADS)

Heck, Robert; Sherson, Jacob F.; www. scienceathome. org Team; players Team

2017-04-01

In science, strategies are formulated based on observations, calculations, or physical insight. For any given physical process, often several distinct strategies are identified. Are these truly distinct or simply low dimensional representations of a high dimensional continuum of solutions? Our online citizen science platform www.scienceathome.org used by more than 150,000 people recently enabled finding solutions to fast, 1D single atom transport [Nature2016]. Surprisingly, player trajectories bunched into discrete solution strategies (clans) yielding clear, distinct physical insight. Introducing the multi-dimensional vector in the direction of other local maxima we locate narrow, high-yield ``bridges'' connecting the clans. This demonstrates for this problem that a continuum of solutions with no clear physical interpretation does in fact exist. Next, four distinct strategies for creating Bose-Einstein condensates were investigated experimentally: hybrid and crossed dipole trap configurations in combination with either large volume or dimple loading from a magnetic trap. We find that although each conventional strategy appears locally optimal, ``bridges'' can be identified. In a novel approach, the problem was gamified allowing 750 citizen scientists to contribute to the experimental optimization yielding nearly a factor two improvement in atom number.

Bridging Gender Gap in the Physics Classroom: The Instructional Method Perspective

ERIC Educational Resources Information Center

Obafemi, Deborah T. A.

2015-01-01

The study investigated the influence of students' gender on their understanding, application and analysis of Light waves concept in physics in Ikwerre Local Government Area of Rivers State, Nigeria. A quasi-experimental pretest-posttest design comprising of three experimental and one control group was used, each group was taught with a different…

Professional "Development" and Professional "Learning": Bridging the Gap for Experienced Physical Education Teachers

ERIC Educational Resources Information Center

Armour, Kathleen M.; Yelling, Martin

2004-01-01

This article analyses the career-long continuing professional development (CPD) of 85 experienced physical education (PE) teachers in England. Data were collected using semi-structured interviews (20 teachers) and open-ended profile questionnaires (a further 65 teachers) to find out what forms of professional development these teachers had…

An Analogy-Based Computer Tutor for Remediating Physics Misconceptions. Draft.

ERIC Educational Resources Information Center

Murray, Tom; And Others

This paper evaluates the strengths and limitations of a computer tutor designed to help students understand physics concepts. The tutor uses a teaching strategy called "bridging analogies" that previous research has demonstrated to be successful in one-to-one tutoring. The strategy is designed to remedy misconceptions by appealing to existing…

The Human Landscape - The Functional Bridge Between the Physical, Economic, and Social Elements of Community Resilience

DOE PAGES

Hummel, John R.; Schneider, Jennifer L.

2016-11-09

Here, community resilience results from the collective output of a set of elements within contributing systems. Obvious ones are the physical elements of the supporting infrastructures; the rules and regulations under which they operate; and the economic mechanics by which they are developed, operated, and maintained.

The Human Landscape - The Functional Bridge Between the Physical, Economic, and Social Elements of Community Resilience

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

Hummel, John R.; Schneider, Jennifer L.

Here, community resilience results from the collective output of a set of elements within contributing systems. Obvious ones are the physical elements of the supporting infrastructures; the rules and regulations under which they operate; and the economic mechanics by which they are developed, operated, and maintained.

Infinite variance in fermion quantum Monte Carlo calculations.

PubMed

Shi, Hao; Zhang, Shiwei

2016-03-01

For important classes of many-fermion problems, quantum Monte Carlo (QMC) methods allow exact calculations of ground-state and finite-temperature properties without the sign problem. The list spans condensed matter, nuclear physics, and high-energy physics, including the half-filled repulsive Hubbard model, the spin-balanced atomic Fermi gas, and lattice quantum chromodynamics calculations at zero density with Wilson Fermions, and is growing rapidly as a number of problems have been discovered recently to be free of the sign problem. In these situations, QMC calculations are relied on to provide definitive answers. Their results are instrumental to our ability to understand and compute properties in fundamental models important to multiple subareas in quantum physics. It is shown, however, that the most commonly employed algorithms in such situations have an infinite variance problem. A diverging variance causes the estimated Monte Carlo statistical error bar to be incorrect, which can render the results of the calculation unreliable or meaningless. We discuss how to identify the infinite variance problem. An approach is then proposed to solve the problem. The solution does not require major modifications to standard algorithms, adding a "bridge link" to the imaginary-time path integral. The general idea is applicable to a variety of situations where the infinite variance problem may be present. Illustrative results are presented for the ground state of the Hubbard model at half-filling.

A Statistician's View of Upcoming Grand Challenges

NASA Astrophysics Data System (ADS)

Meng, Xiao Li

2010-01-01

In this session we have seen some snapshots of the broad spectrum of challenges, in this age of huge, complex, computer-intensive models, data, instruments,and questions. These challenges bridge astronomy at many wavelengths; basic physics; machine learning; -- and statistics. At one end of our spectrum, we think of 'compressing' the data with non-parametric methods. This raises the question of creating 'pseudo-replicas' of the data for uncertainty estimates. What would be involved in, e.g. boot-strap and related methods? Somewhere in the middle are these non-parametric methods for encapsulating the uncertainty information. At the far end, we find more model-based approaches, with the physics model embedded in the likelihood and analysis. The other distinctive problem is really the 'black-box' problem, where one has a complicated e.g. fundamental physics-based computer code, or 'black box', and one needs to know how changing the parameters at input -- due to uncertainties of any kind -- will map to changing the output. All of these connect to challenges in complexity of data and computation speed. Dr. Meng will highlight ways to 'cut corners' with advanced computational techniques, such as Parallel Tempering and Equal Energy methods. As well, there are cautionary tales of running automated analysis with real data -- where "30 sigma" outliers due to data artifacts can be more common than the astrophysical event of interest.

Device-independent point estimation from finite data and its application to device-independent property estimation

NASA Astrophysics Data System (ADS)

Lin, Pei-Sheng; Rosset, Denis; Zhang, Yanbao; Bancal, Jean-Daniel; Liang, Yeong-Cherng

2018-03-01

The device-independent approach to physics is one where conclusions are drawn directly from the observed correlations between measurement outcomes. In quantum information, this approach allows one to make strong statements about the properties of the underlying systems or devices solely via the observation of Bell-inequality-violating correlations. However, since one can only perform a finite number of experimental trials, statistical fluctuations necessarily accompany any estimation of these correlations. Consequently, an important gap remains between the many theoretical tools developed for the asymptotic scenario and the experimentally obtained raw data. In particular, a physical and concurrently practical way to estimate the underlying quantum distribution has so far remained elusive. Here, we show that the natural analogs of the maximum-likelihood estimation technique and the least-square-error estimation technique in the device-independent context result in point estimates of the true distribution that are physical, unique, computationally tractable, and consistent. They thus serve as sound algorithmic tools allowing one to bridge the aforementioned gap. As an application, we demonstrate how such estimates of the underlying quantum distribution can be used to provide, in certain cases, trustworthy estimates of the amount of entanglement present in the measured system. In stark contrast to existing approaches to device-independent parameter estimations, our estimation does not require the prior knowledge of any Bell inequality tailored for the specific property and the specific distribution of interest.

Workshop on Harmonic Oscillators

NASA Technical Reports Server (NTRS)

Han, D. (Editor); Kim, Y. S. (Editor); Zachary, W. W. (Editor)

1993-01-01

Proceedings of a workshop on Harmonic Oscillators held at the College Park Campus of the University of Maryland on March 25 - 28, 1992 are presented. The harmonic oscillator formalism is playing an important role in many branches of physics. This is the simplest mathematical device which can connect the basic principle of physics with what is observed in the real world. The harmonic oscillator is the bridge between pure and applied physics.

Evaluating abdominal core muscle fatigue: Assessment of the validity and reliability of the prone bridging test.

PubMed

De Blaiser, C; De Ridder, R; Willems, T; Danneels, L; Vanden Bossche, L; Palmans, T; Roosen, P

2018-02-01

The aims of this study were to research the amplitude and median frequency characteristics of selected abdominal, back, and hip muscles of healthy subjects during a prone bridging endurance test, based on surface electromyography (sEMG), (a) to determine if the prone bridging test is a valid field test to measure abdominal muscle fatigue, and (b) to evaluate if the current method of administrating the prone bridging test is reliable. Thirty healthy subjects participated in this experiment. The sEMG activity of seven abdominal, back, and hip muscles was bilaterally measured. Normalized median frequencies were computed from the EMG power spectra. The prone bridging tests were repeated on separate days to evaluate inter and intratester reliability. Significant differences in normalized median frequency slope (NMF slope ) values between several abdominal, back, and hip muscles could be demonstrated. Moderate-to-high correlation coefficients were shown between NMF slope values and endurance time. Multiple backward linear regression revealed that the test endurance time could only be significantly predicted by the NMF slope of the rectus abdominis. Statistical analysis showed excellent reliability (ICC=0.87-0.89). The findings of this study support the validity and reliability of the prone bridging test for evaluating abdominal muscle fatigue. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

ArrayBridge: Interweaving declarative array processing with high-performance computing

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

Xing, Haoyuan; Floratos, Sofoklis; Blanas, Spyros

Scientists are increasingly turning to datacenter-scale computers to produce and analyze massive arrays. Despite decades of database research that extols the virtues of declarative query processing, scientists still write, debug and parallelize imperative HPC kernels even for the most mundane queries. This impedance mismatch has been partly attributed to the cumbersome data loading process; in response, the database community has proposed in situ mechanisms to access data in scientific file formats. Scientists, however, desire more than a passive access method that reads arrays from files. This paper describes ArrayBridge, a bi-directional array view mechanism for scientific file formats, that aimsmore » to make declarative array manipulations interoperable with imperative file-centric analyses. Our prototype implementation of ArrayBridge uses HDF5 as the underlying array storage library and seamlessly integrates into the SciDB open-source array database system. In addition to fast querying over external array objects, ArrayBridge produces arrays in the HDF5 file format just as easily as it can read from it. ArrayBridge also supports time travel queries from imperative kernels through the unmodified HDF5 API, and automatically deduplicates between array versions for space efficiency. Our extensive performance evaluation in NERSC, a large-scale scientific computing facility, shows that ArrayBridge exhibits statistically indistinguishable performance and I/O scalability to the native SciDB storage engine.« less

A probabilistic analysis of electrical equipment vulnerability to carbon fibers

NASA Technical Reports Server (NTRS)

Elber, W.

1980-01-01

The statistical problems of airborne carbon fibers falling onto electrical circuits were idealized and analyzed. The probability of making contact between randomly oriented finite length fibers and sets of parallel conductors with various spacings and lengths was developed theoretically. The probability of multiple fibers joining to bridge a single gap between conductors, or forming continuous networks is included. From these theoretical considerations, practical statistical analyses to assess the likelihood of causing electrical malfunctions was produced. The statistics obtained were confirmed by comparison with results of controlled experiments.

Building Bridges Using the Shriners Hospitals for Children/American Burn Association Burn Outcome Questionnaires to Follow Teenagers and Young Adults Across the Age Spans.

PubMed

Kaat, Aaron J; Chen, Liang; Kazis, Lewis E; Lee, Austin F; Shapiro, Gabriel D; Sheridan, Robert L; Ryan, Colleen M; Schneider, Jeffrey C

2017-05-04

The Shriners Hospitals for Children/American Burn Association Burn Outcomes Questionnaires (BOQ) are well-established, reliable, and valid outcome measures. The adolescent (BOQ11-18 years) and young adult version (18-30 years) have similar overlapping domains, but the scores are not comparable. This study objective was to build bridges across these forms. Datasets were from the Multi-Center Benchmarking Study Group. The comparable subscales from the BOQ11-18 and the young adult version were bridged using item response theory cocalibration. The item response theory scale scores were then transformed into an expected raw score on the alternative form, from which normative scores are available. A sensitivity analysis using up to three time points, as opposed to one randomly selected occasion, was also conducted to ensure robust results. Data were available on 353 unique adolescents and 148 young adults. The comparable subscales were successfully bridged across forms (adolescent reliability from 0.67 to 0.85; young adult from 0.69 to 0.88). Compared with adolescents, young adults on average reported more pain and itch, less symptom and role satisfaction, and poorer work/school reintegration (Cohen's d = 0.39-0.77; P < .05). Physical functioning, appearance, and family/parental concern were comparable across ages (d = -0.01 to 0.09; P > .05). Family functioning was better for young adults than adolescents (d = -0.25; P = .006). BOQ11-18 scores can be mapped from adolescence into young adulthood. Physical and psychosocial outcomes change across this life span. Bridges provide a highly useful approach to track changes across this part of the lifespan.

Comparison of effects of seven treatment methods for distal radius fracture on minimizing complex regional pain syndrome

PubMed Central

Sun, Tao

2016-01-01

Introduction Using network meta-analysis, we evaluated the adverse effects of the seven most common treatment methods, i.e., bridging external fixation, non-bridging external fixation, K-wire fixation, plaster fixation, dorsal plating, volar plating, and dorsal and volar plating, by their associated risk of developing complex regional pain syndrome (CRPS) in distal radius fracture (DRF) patients. Material and methods Following an exhaustive search of scientific literature databases for high quality studies, randomized controlled trials (RCTs) related to our study topic were screened and selected based on stringent predefined inclusion and exclusion criteria. Data extracted from the selected studies were used for statistical analyses using Stata 12.0 software. Results A total of 17 RCTs, including 1658 DRF patients, were enrolled in this network meta-analysis. Among the 1658 DRF patients, 452 received bridging external fixation, 525 received non-bridging external fixation, 154 received K-wire fixation, 84 received plaster fixation, 132 received dorsal plating, 123 received volar plating, and 188 received dorsal and volar plating. When compared to bridging external fixation patients, there was no marked difference in the CRPS risk in DRF patients receiving different treatments (all p > 0.05). However, the surface under the cumulative ranking curves (SUCRA) for plaster fixation (77.0%) and non-bridging external fixation (71.3%) were significantly higher compared with the other five methods. Conclusions Our findings suggest that compared with bridging external fixation, K-wire fixation, dorsal plating, volar plating, dorsal and volar plating, plaster fixation and non-bridging external fixation might be the better treatment methods to reduce the risk of CRPS in DRF patients. PMID:28144268

From Bridges and Rockets, Lessons for Software Systems

NASA Technical Reports Server (NTRS)

Holloway, C. Michael

2004-01-01

Although differences exist between building software systems and building physical structures such as bridges and rockets, enough similarities exist that software engineers can learn lessons from failures in traditional engineering disciplines. This paper draws lessons from two well-known failures the collapse of the Tacoma Narrows Bridge in 1940 and the destruction of the space shuttle Challenger in 1986 and applies these lessons to software system development. The following specific applications are made: (1) the verification and validation of a software system should not be based on a single method, or a single style of methods; (2) the tendency to embrace the latest fad should be overcome; and (3) the introduction of software control into safety-critical systems should be done cautiously.

Bridging the physical scales in evolutionary biology: From protein sequence space to fitness of organisms and populations

PubMed Central

Bershtein, Shimon; Serohijos, Adrian W.R.; Shakhnovich, Eugene I.

2016-01-01

Bridging the gap between the molecular properties of proteins and organismal/population fitness is essential for understanding evolutionary processes. This task requires the integration of the several physical scales of biological organization, each defined by a distinct set of mechanisms and constraints, into a single unifying model. The molecular scale is dominated by the constraints imposed by the physico-chemical properties of proteins and their substrates, which give rise to trade-offs and epistatic (non-additive) effects of mutations. At the systems scale, biological networks modulate protein expression and can either buffer or enhance the fitness effects of mutations. The population scale is influenced by the mutational input, selection regimes, and stochastic changes affecting the size and structure of populations, which eventually determine the evolutionary fate of mutations. Here, we summarize the recent advances in theory, computer simulations, and experiments that advance our understanding of the links between various physical scales in biology. PMID:27810574

Bridging the physical scales in evolutionary biology: from protein sequence space to fitness of organisms and populations.

PubMed

Bershtein, Shimon; Serohijos, Adrian Wr; Shakhnovich, Eugene I

2017-02-01

Bridging the gap between the molecular properties of proteins and organismal/population fitness is essential for understanding evolutionary processes. This task requires the integration of the several physical scales of biological organization, each defined by a distinct set of mechanisms and constraints, into a single unifying model. The molecular scale is dominated by the constraints imposed by the physico-chemical properties of proteins and their substrates, which give rise to trade-offs and epistatic (non-additive) effects of mutations. At the systems scale, biological networks modulate protein expression and can either buffer or enhance the fitness effects of mutations. The population scale is influenced by the mutational input, selection regimes, and stochastic changes affecting the size and structure of populations, which eventually determine the evolutionary fate of mutations. Here, we summarize the recent advances in theory, computer simulations, and experiments that advance our understanding of the links between various physical scales in biology. Copyright © 2016 Elsevier Ltd. All rights reserved.

Building vulnerability to hydro-geomorphic hazards: Estimating damage probability from qualitative vulnerability assessment using logistic regression

NASA Astrophysics Data System (ADS)

Ettinger, Susanne; Mounaud, Loïc; Magill, Christina; Yao-Lafourcade, Anne-Françoise; Thouret, Jean-Claude; Manville, Vern; Negulescu, Caterina; Zuccaro, Giulio; De Gregorio, Daniela; Nardone, Stefano; Uchuchoque, Juan Alexis Luque; Arguedas, Anita; Macedo, Luisa; Manrique Llerena, Nélida

2016-10-01

The focus of this study is an analysis of building vulnerability through investigating impacts from the 8 February 2013 flash flood event along the Avenida Venezuela channel in the city of Arequipa, Peru. On this day, 124.5 mm of rain fell within 3 h (monthly mean: 29.3 mm) triggering a flash flood that inundated at least 0.4 km2 of urban settlements along the channel, affecting more than 280 buildings, 23 of a total of 53 bridges (pedestrian, vehicle and railway), and leading to the partial collapse of sections of the main road, paralyzing central parts of the city for more than one week. This study assesses the aspects of building design and site specific environmental characteristics that render a building vulnerable by considering the example of a flash flood event in February 2013. A statistical methodology is developed that enables estimation of damage probability for buildings. The applied method uses observed inundation height as a hazard proxy in areas where more detailed hydrodynamic modeling data is not available. Building design and site-specific environmental conditions determine the physical vulnerability. The mathematical approach considers both physical vulnerability and hazard related parameters and helps to reduce uncertainty in the determination of descriptive parameters, parameter interdependency and respective contributions to damage. This study aims to (1) enable the estimation of damage probability for a certain hazard intensity, and (2) obtain data to visualize variations in damage susceptibility for buildings in flood prone areas. Data collection is based on a post-flood event field survey and the analysis of high (sub-metric) spatial resolution images (Pléiades 2012, 2013). An inventory of 30 city blocks was collated in a GIS database in order to estimate the physical vulnerability of buildings. As many as 1103 buildings were surveyed along the affected drainage and 898 buildings were included in the statistical analysis. Univariate and bivariate analyses were applied to better characterize each vulnerability parameter. Multiple corresponding analyses revealed strong relationships between the "Distance to channel or bridges", "Structural building type", "Building footprint" and the observed damage. Logistic regression enabled quantification of the contribution of each explanatory parameter to potential damage, and determination of the significant parameters that express the damage susceptibility of a building. The model was applied 200 times on different calibration and validation data sets in order to examine performance. Results show that 90% of these tests have a success rate of more than 67%. Probabilities (at building scale) of experiencing different damage levels during a future event similar to the 8 February 2013 flash flood are the major outcomes of this study.

Performance Assessment of Bridges Using GPS: The Juarez Bridge in Culiacan, Mexico

NASA Astrophysics Data System (ADS)

Vazquez, G. E.; Gaxiola-Camacho, J. R.; Trejo, M.; Echagaray, J.; Guzman, G. M.

2015-12-01

Performance assessment of bridges has become very important during recent years. Bridges around the world are aging, leading to the incorporation of efficient, reliable, and economic evaluation procedures. These techniques must assess properly the performance of bridges under several loading conditions in a real manner, representing the physics of the problem. Among several approaches, Global Positioning System (GPS) can be intelligently used for the performance evaluation of bridges. We focused on GPS, since it naturally produces position estimates as compared to seismic instruments that record either velocity or acceleration, and thus require an integration. There are several reasons that make the Juarez Bridge a case of study for evaluation: it is approximately 45 years old, it is a reinforced concrete structure, it connects two significant zones of the city, and its spans is closely to 200 meters long. In addition, thousands of vehicles and pedestrians use the Juarez Bridge every day, which make feasible the GPS performance assessment. Hence, in order to produce optimal position estimates, GPS data were collected during two consecutive hours at three different periods of the day for a whole week (Monday through Sunday), to represent three critical limit states of the bridge (mid-span and end-spans). GPS data were processed using the GAMIT/GLOBK software, considering 1-second sampling rate, 15-degree cutoff angle, ionosphere-free double-differenced (DD) carrier phase method, and precise final orbits disseminated by IGS (International GNSS Service). The displacements obtained from the above discussed procedure are compared with allowable values documented in bridge construction manuals. Reliability theory was used to evaluate the probability of failure of the bridge for the three periods of the day. In addition, a conclusion was made about the most risky day of the week for the use of the Juarez Bridge. It is expected that the results from the proposed research will provide enough information to document non-permissible movements of the Juarez Bridge. Finally, guidance for future retrofit of the structure will be fully available.

An Experimental Investigation on the Static Equilibria and Dynamics of Liquid Bridges. Degree Awarded by the University of Alabama, 1997

NASA Technical Reports Server (NTRS)

Resnick, Andrew Howard

1997-01-01

A liquid bridge is a volume of liquid held between two or more solid supports. In the case of small disk supports with a sharp edge, the contact line between the bridge and the support disk will be anchored along the edge of the disk. For these cases the solid presents a geometrical singularity and the contact angle is indeterminate within a given range. This dissertation presents research conducted on liquid bridges with anchored contact lines. The three major topics covered are: determining the role of support geometry on static equilibria, liquid bridge dynamical behavior, and forces exerted by a liquid bridge on a support structure. The work was primarily experimental and conducted in a "Plateau tank" that allowed for the simulation of equivalent low-gravity conditions. The main thrust of the experimental work involved the use of a high resolution optical measurement system for imaging the dynamic zone shape, measurement of the static and dynamic contact angles and non-invasive analysis of excited surface modes. The liquid bridge was manipulated by computer controlled linear actuators which allowed precise control over the physical characteristics of the bridge. Experiments have been carried out to locate a bifurcation point along the maximum volume axisymmetric stability margin. Below the critical slenderness the bifurcation from an axisymmetric to a stable nonaxisymmetric configuration is supercritical. However, above this critical slenderness, the bifurcation is subcritical. A series of experiments analyzed the effect on axisymmetric bridge stability by using support disks of different radii, The shape behavior as transition points were approached, as well as the limiting case of a vanishing support radius was investigated. Experiments were performed to determine the resonant frequencies of axisymmetric bridges subject to lateral vibrations. Anomolous results led to a series of experiments to characterize nonlinearities present in the dynamic bridge shape. Finally, an attempt was made to experimentally measure the force exerted by the bridge on the lower support disk. This was done through use of a force balance apparatus. Particular attention was paid to the behavior of the bridge as the minimum volume stability limit was approached.

Social Capital and Health Outcomes among Older Adults in China: The Urban-Rural Dimension

ERIC Educational Resources Information Center

Norstrand, Julie A.; Xu, Qingwen

2012-01-01

Purpose: This study examines different types of individual-level social capital (bonding, bridging, and linking) and their relationships with physical and emotional health among older Chinese living in urban and rural settings. Design and Methods: Using the 2005 China General Social Survey, physical and emotional health were regressed on social…

Innovative Interdisciplinary Training in and Delivery of Evidence-Based Geriatric Services: Creating a Bridge with Social Work and Physical Therapy

ERIC Educational Resources Information Center

Rowan, Noell L.; Gillette, Patricia D.; Faul, Anna C.; Yankeelov, Pamela A.; Borders, Kevin W.; Deck, Stacy; Nicholas, Lori D.; Wiegand, Mark

2009-01-01

With focus on interdisciplinary education models, social work and physical therapy faculty from two proximate universities partnered to create an evidence-based geriatric assessment and brief intervention research, training, and service project for community-dwelling older adults. Assessment tools and interventions were selected from the…

BRIDG: a domain information model for translational and clinical protocol-driven research.

PubMed

Becnel, Lauren B; Hastak, Smita; Ver Hoef, Wendy; Milius, Robert P; Slack, MaryAnn; Wold, Diane; Glickman, Michael L; Brodsky, Boris; Jaffe, Charles; Kush, Rebecca; Helton, Edward

2017-09-01

It is critical to integrate and analyze data from biological, translational, and clinical studies with data from health systems; however, electronic artifacts are stored in thousands of disparate systems that are often unable to readily exchange data. To facilitate meaningful data exchange, a model that presents a common understanding of biomedical research concepts and their relationships with health care semantics is required. The Biomedical Research Integrated Domain Group (BRIDG) domain information model fulfills this need. Software systems created from BRIDG have shared meaning "baked in," enabling interoperability among disparate systems. For nearly 10 years, the Clinical Data Standards Interchange Consortium, the National Cancer Institute, the US Food and Drug Administration, and Health Level 7 International have been key stakeholders in developing BRIDG. BRIDG is an open-source Unified Modeling Language-class model developed through use cases and harmonization with other models. With its 4+ releases, BRIDG includes clinical and now translational research concepts in its Common, Protocol Representation, Study Conduct, Adverse Events, Regulatory, Statistical Analysis, Experiment, Biospecimen, and Molecular Biology subdomains. The model is a Clinical Data Standards Interchange Consortium, Health Level 7 International, and International Standards Organization standard that has been utilized in national and international standards-based software development projects. It will continue to mature and evolve in the areas of clinical imaging, pathology, ontology, and vocabulary support. BRIDG 4.1.1 and prior releases are freely available at https://bridgmodel.nci.nih.gov . © The Author 2017. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Biomechanical Comparison of Modified Suture Bridge Using Rip-Stop versus Traditional Suture Bridge for Rotator Cuff Repair

PubMed Central

Zhang, Peng; Chen, TianWu; Chen, ShiYi

2016-01-01

Purpose. To compare the biomechanical properties of 3 suture-bridge techniques for rotator cuff repair. Methods. Twelve pair-matched fresh-frozen shoulder specimens were randomized to 3 groups of different repair types: the medially Knotted Suture Bridge (KSB), the medially Untied Suture Bridge (USB), and the Modified Suture Bridge (MSB). Cyclic loading and load-to-failure test were performed. Parameters of elongation, stiffness, load at failure, and mode of failure were recorded. Results. The MSB technique had the significantly greatest load to failure (515.6 ± 78.0 N, P = 0.04 for KSB group; P < 0.001 for USB group), stiffness (58.0 ± 10.7 N/mm, P = 0.005 for KSB group; P < 0.001 for USB group), and lowest elongation (1.49 ± 0.39 mm, P = 0.009 for KSB group; P = 0.001 for USB group) among 3 groups. The KSB repair had significantly higher ultimate load (443.5 ± 65.0 N) than USB repair (363.5 ± 52.3 N, P = 0.024). However, there was no statistical difference in stiffness and elongation between KSB and USB technique (P = 0.396 for stiffness and P = 0.242 for elongation, resp.). The failure mode for all specimens was suture pulling through the cuff tendon. Conclusions. Our modified suture bridge technique (MSB) may provide enhanced biomechanical properties when compared with medially knotted or knotless repair. Clinical Relevance. Our modified technique may represent a promising alternative in arthroscopic rotator cuff repair. PMID:27975065

Evaluation of footprint contact area and pressure using a triple-row modification of the suture-bridge technique for rotator cuff repair.

PubMed

Ostrander, Roger V; McKinney, Bart I

2012-10-01

Studies suggest that arthroscopic repair techniques may have high recurrence rates for larger rotator cuff tears. A more anatomic repair may improve the success rate when performing arthroscopic rotator cuff repair. We hypothesized that a triple-row modification of the suture-bridge technique for rotator cuff repair would result in significantly more footprint contact area and pressure between the rotator cuff and the humeral tuberosity. Eighteen ovine infraspinatus tendons were repaired using 1 of 3 simulated arthroscopic techniques: a double-row repair, the suture-bridge technique, and a triple-row repair. The triple-row repair technique is a modification of the suture-bridge technique that uses an additional reducing anchor between the medial and lateral rows. Six samples were tested per group. Pressure-indicating film was used to measure the footprint contact area and pressure after each repair. The triple-row repair resulted in significantly more rotator cuff footprint contact area and contact pressure compared with the double-row technique and the standard suture-bridge technique. No statistical difference in contact area or contact pressure was found between the double-row technique and the suture-bridge technique. The triple-row technique for rotator cuff repair results in significantly more footprint contact area and contact pressure compared with the double-row and standard suture-bridge techniques. This more anatomic repair may improve the healing rate when performing arthroscopic rotator cuff repair. Copyright © 2012 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

Co-Conserved MAPK Features Couple D-Domain Docking Groove to Distal Allosteric Sites via the C-Terminal Flanking Tail

PubMed Central

Nguyen, Tuan; Ruan, Zheng; Oruganty, Krishnadev; Kannan, Natarajan

2015-01-01

Mitogen activated protein kinases (MAPKs) form a closely related family of kinases that control critical pathways associated with cell growth and survival. Although MAPKs have been extensively characterized at the biochemical, cellular, and structural level, an integrated evolutionary understanding of how MAPKs differ from other closely related protein kinases is currently lacking. Here, we perform statistical sequence comparisons of MAPKs and related protein kinases to identify sequence and structural features associated with MAPK functional divergence. We show, for the first time, that virtually all MAPK-distinguishing sequence features, including an unappreciated short insert segment in the β4-β5 loop, physically couple distal functional sites in the kinase domain to the D-domain peptide docking groove via the C-terminal flanking tail (C-tail). The coupling mediated by MAPK-specific residues confers an allosteric regulatory mechanism unique to MAPKs. In particular, the regulatory αC-helix conformation is controlled by a MAPK-conserved salt bridge interaction between an arginine in the αC-helix and an acidic residue in the C-tail. The salt-bridge interaction is modulated in unique ways in individual sub-families to achieve regulatory specificity. Our study is consistent with a model in which the C-tail co-evolved with the D-domain docking site to allosterically control MAPK activity. Our study provides testable mechanistic hypotheses for biochemical characterization of MAPK-conserved residues and new avenues for the design of allosteric MAPK inhibitors. PMID:25799139

A new approach for structural health monitoring by applying anomaly detection on strain sensor data

NASA Astrophysics Data System (ADS)

Trichias, Konstantinos; Pijpers, Richard; Meeuwissen, Erik

2014-03-01

Structural Health Monitoring (SHM) systems help to monitor critical infrastructures (bridges, tunnels, etc.) remotely and provide up-to-date information about their physical condition. In addition, it helps to predict the structure's life and required maintenance in a cost-efficient way. Typically, inspection data gives insight in the structural health. The global structural behavior, and predominantly the structural loading, is generally measured with vibration and strain sensors. Acoustic emission sensors are more and more used for measuring global crack activity near critical locations. In this paper, we present a procedure for local structural health monitoring by applying Anomaly Detection (AD) on strain sensor data for sensors that are applied in expected crack path. Sensor data is analyzed by automatic anomaly detection in order to find crack activity at an early stage. This approach targets the monitoring of critical structural locations, such as welds, near which strain sensors can be applied during construction and/or locations with limited inspection possibilities during structural operation. We investigate several anomaly detection techniques to detect changes in statistical properties, indicating structural degradation. The most effective one is a novel polynomial fitting technique, which tracks slow changes in sensor data. Our approach has been tested on a representative test structure (bridge deck) in a lab environment, under constant and variable amplitude fatigue loading. In both cases, the evolving cracks at the monitored locations were successfully detected, autonomously, by our AD monitoring tool.

Wildfires: Information for Parents

MedlinePlus

... cleaner air, rather than give them a mask. Outdoor activity should be minimized, and athletic and physical ... be unstable and fall Roadways, bridges, and other outdoor structures that may be damaged and unstable Animals ...

Extending Counter-streaming Motion from an Active Region Filament to a Sunspot Light Bridge

NASA Astrophysics Data System (ADS)

Wang, Haimin; Liu, Rui; Li, Qin; Liu, Chang; Deng, Na; Xu, Yan; Jing, Ju; Wang, Yuming; Cao, Wenda

2018-01-01

We analyze high-resolution observations from the 1.6 m telescope at Big Bear Solar Observatory that cover an active region filament. Counter-streaming motions are clearly observed in the filament. The northern end of the counter-streaming motions extends to a light bridge, forming a spectacular circulation pattern around a sunspot, with clockwise motion in the blue wing and counterclockwise motion in the red wing, as observed in the Hα off-bands. The apparent speed of the flow is around 10–60 km s‑1 in the filament, decreasing to 5–20 km s‑1 in the light bridge. The most intriguing results are the magnetic structure and the counter-streaming motions in the light bridge. Similar to those in the filament, the magnetic fields show a dominant transverse component in the light bridge. However, the filament is located between opposed magnetic polarities, while the light bridge is between strong fields of the same polarity. We analyze the power of oscillations with the image sequences of constructed Dopplergrams, and find that the filament’s counter-streaming motion is due to physical mass motion along fibrils, while the light bridge’s counter-streaming motion is due to oscillation in the direction along the line-of-sight. The oscillation power peaks around 4 minutes. However, the section of the light bridge next to the filament also contains a component of the extension of the filament in combination with the oscillation, indicating that some strands of the filament are extended to and rooted in that part of the light bridge.

Stress stiffened silicon nitride micro bridges array as substrate with tunable stiffness for cell culture.

PubMed

Chen, Jianfeng; Liu, Guangli; Ma, Chengfu; Zhao, Gang; Du, Wenqiang; Zhu, Wulin; Chu, Jiaru

2017-06-01

Recently, interactions between one-dimensional structural stiffness of physical micro environments and cell biological process have been widely studied. However in previous studies, the influence of structural stiffness on biological process was coupled with the influence of micro fiber curvature. Therefore decoupling the influences of fiber curvature and structural stiffness on cell biological process is of prime importance. In this study, we proposed a novel cell culture substrate comprised of silicon nitride bridges whose structure stiffness can be regulated by altering the axial residual stress without changing material and geometry properties. Both theoretical calculations and finite element simulations were performed to study the influence of residual stress on structure stiffness of bridges. Then multi-positions AFM bending tests were implemented to measure local stiffness of a single micro bridge so as to verify our predictions. NIH/3T3 mouse fibroblast cells were cultured on our substrates to examine the feasibility of the substrate application for investigating cellular response to microenvironment with variable stiffness. The results showed that cells on the edge region near bridge ends were more spread, elongated and better aligned along the bridge axial direction than those on the bridge center region. The results suggest that cells can sense and respond to the differences of stiffness and stiffness gradient between the edge and the center region of the bridges, which makes this kind of substrates can be applied in some biomedical fields, such as cell migration and wound healing. Copyright © 2017 Elsevier B.V. All rights reserved.

A predictive Bayesian approach to the design and analysis of bridging studies.

PubMed

Gould, A Lawrence; Jin, Tian; Zhang, Li Xin; Wang, William W B

2012-09-01

Pharmaceutical product development culminates in confirmatory trials whose evidence for the product's efficacy and safety supports regulatory approval for marketing. Regulatory agencies in countries whose patients were not included in the confirmatory trials often require confirmation of efficacy and safety in their patient populations, which may be accomplished by carrying out bridging studies to establish consistency for local patients of the effects demonstrated by the original trials. This article describes and illustrates an approach for designing and analyzing bridging studies that fully incorporates the information provided by the original trials. The approach determines probability contours or regions of joint predictive intervals for treatment effect and response variability, or endpoints of treatment effect confidence intervals, that are functions of the findings from the original trials, the sample sizes for the bridging studies, and possible deviations from complete consistency with the original trials. The bridging studies are judged consistent with the original trials if their findings fall within the probability contours or regions. Regulatory considerations determine the region definitions and appropriate probability levels. Producer and consumer risks provide a way to assess alternative region and probability choices. [Supplemental materials are available for this article. Go to the Publisher's online edition of the Journal of Biopharmaceutical Statistics for the following free supplemental resource: Appendix 2: R code for Calculations.].

Finite element model updating and damage detection for bridges using vibration measurement.

DOT National Transportation Integrated Search

2013-12-01

In this report, the results of a study on developing a damage detection methodology based on Statistical Pattern Recognition are : presented. This methodology uses a new damage sensitive feature developed in this study that relies entirely on modal :...

Addressing the issue of insufficient information in data-based bridge health monitoring : final report.

DOT National Transportation Integrated Search

2015-11-01

One of the most efficient ways to solve the damage detection problem using the statistical pattern recognition : approach is that of exploiting the methods of outlier analysis. Cast within the pattern recognition framework, : damage detection assesse...

Spontaneous emergence of rogue waves in partially coherent waves: A quantitative experimental comparison between hydrodynamics and optics

NASA Astrophysics Data System (ADS)

El Koussaifi, R.; Tikan, A.; Toffoli, A.; Randoux, S.; Suret, P.; Onorato, M.

2018-01-01

Rogue waves are extreme and rare fluctuations of the wave field that have been discussed in many physical systems. Their presence substantially influences the statistical properties of a partially coherent wave field, i.e., a wave field characterized by a finite band spectrum with random Fourier phases. Their understanding is fundamental for the design of ships and offshore platforms. In many meteorological conditions waves in the ocean are characterized by the so-called Joint North Sea Wave Project (JONSWAP) spectrum. Here we compare two unique experimental results: the first one has been performed in a 270 m wave tank and the other in optical fibers. In both cases, waves characterized by a JONSWAP spectrum and random Fourier phases have been launched at the input of the experimental device. The quantitative comparison, based on an appropriate scaling of the two experiments, shows a very good agreement between the statistics in hydrodynamics and optics. Spontaneous emergence of heavy tails in the probability density function of the wave amplitude is observed in both systems. The results demonstrate the universal features of rogue waves and provide a fundamental and explicit bridge between two important fields of research. Numerical simulations are also compared with experimental results.

Spontaneous emergence of rogue waves in partially coherent waves: A quantitative experimental comparison between hydrodynamics and optics.

PubMed

El Koussaifi, R; Tikan, A; Toffoli, A; Randoux, S; Suret, P; Onorato, M

2018-01-01

Rogue waves are extreme and rare fluctuations of the wave field that have been discussed in many physical systems. Their presence substantially influences the statistical properties of a partially coherent wave field, i.e., a wave field characterized by a finite band spectrum with random Fourier phases. Their understanding is fundamental for the design of ships and offshore platforms. In many meteorological conditions waves in the ocean are characterized by the so-called Joint North Sea Wave Project (JONSWAP) spectrum. Here we compare two unique experimental results: the first one has been performed in a 270 m wave tank and the other in optical fibers. In both cases, waves characterized by a JONSWAP spectrum and random Fourier phases have been launched at the input of the experimental device. The quantitative comparison, based on an appropriate scaling of the two experiments, shows a very good agreement between the statistics in hydrodynamics and optics. Spontaneous emergence of heavy tails in the probability density function of the wave amplitude is observed in both systems. The results demonstrate the universal features of rogue waves and provide a fundamental and explicit bridge between two important fields of research. Numerical simulations are also compared with experimental results.

Structural characteristics of chloroquine-bridged ferrocenophane analogues of ferroquine may obviate malaria drug-resistance mechanisms.

PubMed

Salas, Paloma F; Herrmann, Christoph; Cawthray, Jacqueline F; Nimphius, Corinna; Kenkel, Alexander; Chen, Jessie; de Kock, Carmen; Smith, Peter J; Patrick, Brian O; Adam, Michael J; Orvig, Chris

2013-02-28

Five compounds displaying an unprecedented binding mode of chloroquine to ferrocene through the bridging of the cyclopentadienyl rings were studied alongside their monosubstituted ferrocene analogues and organic fragments. The antiplasmodial activity was evaluated against strains of the malaria parasite (Plasmodium falciparum). While the chloroquine-bridged ferrocenyl derivatives were less active than their five monosubstituted ferrocenyl analogues, they retained activity in the drug-resistant strains. The biological and physical properties were correlated to antiplasmodial activity. Intramolecular hydrogen bonding was associated with increased antiplasmodial action, but it is not the determining factor. Instead, balance between lipophilicity and hydrophilicity had a greater influence. It was found that calculated partition coefficient (log P) values of 4.5-5.0 and topological polar surfaces area (tPSA) values of ∼26.0 Å(2) give the best balance. The particular conformation, compact size, and lipophilicity/hydrophilicity balance observed in the bridged compounds provide them with the structural characteristics needed to escape the mechanisms responsible for resistance.

Toughening by crack bridging in heterogeneous ceramics

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

Curtin, W.A.

1995-05-01

The toughening of a ceramic by crack bridging is considered, including the heterogeneity caused simply by spatial randomness in the bridge locations. The growth of a single planar crack is investigated numerically by representing the microstructure as an array of discrete springs with heterogeneity in the mechanical properties of each spring. The stresses on each microstructural element are determined, for arbitrary configurations of spring properties and heterogeneity, using a lattice Green function technique. For toughening by (heterogeneous) crack bridging for both elastic and Dugdale bridging mechanisms, the following key physical results are found: (1) growing cracks avoid regions which aremore » efficiently bridged, and do not propagate as self-similar penny cracks; (2) crack growth thus proceeds at lower applied stresses in a heterogeneous material than in an ordered material; (3) very little toughening is evident for moderate amounts of crack growth in many cases; and (4) a different R-curve is found for every particular spatial distribution of bridging elements. These results show that material reliability is determined by both the flaw distribution and the ``toughness`` distribution, or local environment, around each flaw. These results also demonstrate that the ``microstructural`` parameters derived from fitting an R-curve to a continuum model may not have an immediate relationship to the actual microstructure; the parameters are ``effective`` parameters that absorb the effects of the heterogeneity. The conceptual issues illuminated by these conclusions must be fully understood and appreciated to further develop microstructure-property relationships in ceramic materials.« less

Analysis and prediction of operating vehicle load effects on Highway bridges under the weight charge policy

NASA Astrophysics Data System (ADS)

Huang, Haiyun; Zhang, Junping; Li, Yonghe

2018-05-01

Under the weight charge policy, the weigh in motion data at a toll station on the Jing-Zhu Expressway were collected. The statistic analysis of vehicle load data was carried out. For calculating the operating vehicle load effects on bridges, by Monte Carlo method used to generate random traffic flow and influence line loading method, the maximum bending moment effect of simple supported beams were obtained. The extreme value I distribution and normal distribution were used to simulate the distribution of the maximum bending moment effect. By the extrapolation of Rice formula and the extreme value I distribution, the predicted values of the maximum load effects were obtained. By comparing with vehicle load effect according to current specification, some references were provided for the management of the operating vehicles and the revision of the bridge specifications.

Extreme-value statistics of fractional Brownian motion bridges.

PubMed

Delorme, Mathieu; Wiese, Kay Jörg

2016-11-01

Fractional Brownian motion is a self-affine, non-Markovian, and translationally invariant generalization of Brownian motion, depending on the Hurst exponent H. Here we investigate fractional Brownian motion where both the starting and the end point are zero, commonly referred to as bridge processes. Observables are the time t_{+} the process is positive, the maximum m it achieves, and the time t_{max} when this maximum is taken. Using a perturbative expansion around Brownian motion (H=1/2), we give the first-order result for the probability distribution of these three variables and the joint distribution of m and t_{max}. Our analytical results are tested and found to be in excellent agreement, with extensive numerical simulations for both H>1/2 and H<1/2. This precision is achieved by sampling processes with a free end point and then converting each realization to a bridge process, in generalization to what is usually done for Brownian motion.

Probabilistic model of bridge vehicle loads in port area based on in-situ load testing

NASA Astrophysics Data System (ADS)

Deng, Ming; Wang, Lei; Zhang, Jianren; Wang, Rei; Yan, Yanhong

2017-11-01

Vehicle load is an important factor affecting the safety and usability of bridges. An statistical analysis is carried out in this paper to investigate the vehicle load data of Tianjin Haibin highway in Tianjin port of China, which are collected by the Weigh-in- Motion (WIM) system. Following this, the effect of the vehicle load on test bridge is calculated, and then compared with the calculation result according to HL-93(AASHTO LRFD). Results show that the overall vehicle load follows a distribution with a weighted sum of four normal distributions. The maximum vehicle load during the design reference period follows a type I extremum distribution. The vehicle load effect also follows a weighted sum of four normal distributions, and the standard value of the vehicle load is recommended as 1.8 times that of the calculated value according to HL-93.

An uncertainty analysis of the flood-stage upstream from a bridge.

PubMed

Sowiński, M

2006-01-01

The paper begins with the formulation of the problem in the form of a general performance function. Next the Latin hypercube sampling (LHS) technique--a modified version of the Monte Carlo method is briefly described. The essential uncertainty analysis of the flood-stage upstream from a bridge starts with a description of the hydraulic model. This model concept is based on the HEC-RAS model developed for subcritical flow under a bridge without piers in which the energy equation is applied. The next section contains the characteristic of the basic variables including a specification of their statistics (means and variances). Next the problem of correlated variables is discussed and assumptions concerning correlation among basic variables are formulated. The analysis of results is based on LHS ranking lists obtained from the computer package UNCSAM. Results fot two examples are given: one for independent and the other for correlated variables.

Bridging the divide

NASA Astrophysics Data System (ADS)

Tesh, Sarah

2017-09-01

The recent International Conference on Women in Physics shows that there is still a long way to go to reach gender equality. Sarah Tesh reports from Birmingham, UK - where education activist Malala Yousafzai made a surprise appearance

Dynamic Force Measurement with Strain Gauges

ERIC Educational Resources Information Center

Lee, Bruce E.

1974-01-01

Discusses the use of four strain gauges, a Wheatstone bridge, and an oscilloscope to measure forces dynamically. Included is an example of determining the centripetal force of a pendulum in a general physics laboratory. (CC)

The U.S. geological survey rass-statpac system for management and statistical reduction of geochemical data

USGS Publications Warehouse

VanTrump, G.; Miesch, A.T.

1977-01-01

RASS is an acronym for Rock Analysis Storage System and STATPAC, for Statistical Package. The RASS and STATPAC computer programs are integrated into the RASS-STATPAC system for the management and statistical reduction of geochemical data. The system, in its present form, has been in use for more than 9 yr by scores of U.S. Geological Survey geologists, geochemists, and other scientists engaged in a broad range of geologic and geochemical investigations. The principal advantage of the system is the flexibility afforded the user both in data searches and retrievals and in the manner of statistical treatment of data. The statistical programs provide for most types of statistical reduction normally used in geochemistry and petrology, but also contain bridges to other program systems for statistical processing and automatic plotting. ?? 1977.

All in the Family: The Link between Kin Network Bridging and Cardiovascular Risk among Older Adults*

PubMed Central

Goldman, Alyssa

2016-01-01

While considerable work has examined the association between social relationships and health, most of this research focuses on the relevance of social network composition and quality of dyadic ties. In this study, I consider how the social network structure of ties among older adults’ close family members may affect cardiovascular health in later life. Using data from 938 older adults that participated in Waves 1 and 2 of the National Social Life, Health, and Aging Project (NSHAP), I test whether older adults who occupy bridging positions among otherwise disconnected or poorly connected kin in their personal social network are more likely to present elevated levels of C-reactive protein (CRP), a biomarker for cardiovascular risk. Results indicate that occupying a bridging position among family members is significantly associated with elevated CRP. This effect is unique to bridging kin network members. These findings suggest that ties among one’s closest kin may generate important resources and norms that influence older adults’ health, such that bridging kin network members may compromise physical wellbeing. I discuss these results in the context of prior work on social support, family solidarity, and health in later life. PMID:27566043

All in the family: The link between kin network bridging and cardiovascular risk among older adults.

PubMed

Goldman, Alyssa W

2016-10-01

While considerable work has examined the association between social relationships and health, most of this research focuses on the relevance of social network composition and the quality of dyadic ties. In this study, I consider how the social network structure of ties among older adults' close family members may affect cardiovascular health in later life. Using data from 938 older adults that participated in Waves 1 and 2 of the National Social Life, Health, and Aging Project (NSHAP), I test whether older adults who occupy bridging positions among otherwise disconnected or poorly connected kin in their personal social network are more likely to present elevated levels of C-reactive protein (CRP), a biomarker for cardiovascular risk. Results indicate that occupying a bridging position among family members is significantly associated with elevated CRP. This effect is unique to bridging kin network members. These findings suggest that ties among one's closest kin may generate important resources and norms that influence older adults' health, such that bridging kin network members may compromise physical wellbeing. I discuss these results in the context of prior work on social support, family solidarity, and health in later life. Copyright © 2016 Elsevier Ltd. All rights reserved.

Instability of the capillary bridge

NASA Astrophysics Data System (ADS)

Pare, Gounseti; Hoepffner, Jerome

2014-11-01

Capillary adhesion is a physical mechanism that maintains two bodies in contact by capillarity through a liquid ligament. The capillary bridge is an idealization of this capillary adhesion. In this study we first focus on the classical case of the stability of the capillary bridge. Secondly we study a slightly more complex configuration, imagining a flow in the capillary bridge as in the case of the dynamics of the neck of a liquid ligament, in its withdrawal under the effect of capillarity. Inspired by the experiments on soap films of Plateau, the configuration analyzed consists of an initially axisymmetric, mass of fluid held by surface tension forces between two parallel, coaxial, solid pipes of the same diameter. The results presented are obtained by numerical simulations using the free software, Gerris Flow Solver. We first focus on the capillary Venturi. In the static configuration the stability diagram of the capillary bridge obtained is in perfect agreement with the results of Lev A. Slobozhanin. In the dynamic case we develop a matlab code based on the one dimensional equations of Eggers and Dupont. The comparison of the bifurcation diagram obtained and the numerical simulations shows a good agreement.

Bridging the Gap: Developing a Tool to Support Local Civilian and Military Disaster Preparedness

DTIC Science & Technology

2010-01-01

HSC, 2005), the National Strategy for Physical Protection of Critical Infrastructures and Key Assets (DHS, 2003b), the National Strategy for Mari- time...10-2501 (p. 46), The installation CEMP 10-2 provides comprehensive guidance for emergency response to physical threats resulting from major accidents...installations must develop a CEMP 10-2 using the AF [Air Force] template to address the physical threats to their base. . . . The CEMP 10-2 should be

Bridging the Gap between Physical Therapy and Orientation and Mobility in Schools: Using a Collaborative Team Approach for Students with Visual Impairments

ERIC Educational Resources Information Center

Szabo, Joanne; Panikkar, Rajiv K.

2017-01-01

This article explores transdisciplinary collaboration and role-release strategies that would allow physical therapists and orientation and mobility (O&M) specialists to more effectively support students with visual impairments (that is, those who are blind or have low vision) and additional disabilities with their expanded core curriculum…

Statistical Physics of Adaptation

DTIC Science & Technology

2016-08-23

Statistical Physics of Adaptation Nikolay Perunov, Robert A. Marsland, and Jeremy L. England Department of Physics , Physics of Living Systems Group...Subject Areas: Biological Physics , Complex Systems, Statistical Physics I. INTRODUCTION It has long been understood that nonequilibrium driving can...equilibrium may appear to have been specially selected for physical properties connected to their ability to absorb work from the particular driving environment

Past and future changes in streamflow in the U.S. Midwest: Bridging across time scales

NASA Astrophysics Data System (ADS)

Villarini, G.; Slater, L. J.; Salvi, K. A.

2017-12-01

Streamflows have increased notably across the U.S. Midwest over the past century, principally due to changes in precipitation and land use / land cover. Improving our understanding of the physical drivers that are responsible for the observed changes in discharge may enhance our capability of predicting and projecting these changes, and may have large implications for water resources management over this area. This study will highlight our efforts towards the statistical attribution of changes in discharge across the U.S. Midwest, with analyses performed at the seasonal scale from low to high flows. The main drivers of changing streamflows that we focus on are: urbanization, agricultural land cover, basin-averaged temperature, basin-averaged precipitation, and antecedent soil moisture. Building on the insights from this attribution, we will examine the potential predictability of streamflow across different time scales, with lead times ranging from seasonal to decadal, and discuss a potential path forward for engineering design for future conditions.

Flood Control Minnesota River, Minnesota, Minnesota, Mankato-North Mankato-Le Hillier, Design Memorandum Number 8. Part I. Location Study and Draft Supplement II to the Final Environmental Impact Statement for Bridge Relocations. Chicago and Northwestern Transportation Company Bridges Over the Blue Earth River between Mankato and Le Hillier.

DTIC Science & Technology

1981-04-01

230.4-1Cc) (2)) The composition of the biological community was sampled in the study area. The insect association is generally representative of a warm...be considered in discharge determination (40 CFR 230.5(a)) (1) Impacts on chemical, physical, and biological integrity of acuatic ecosystem (40 CFR

[Should the patient with myocardial bridge be advised not to performe extreme sport effort? Case of a patient with troponin I elevation after exercise].

PubMed

Jankowski, Krzysztof; Ożdżeńska-Milke, Ewa; Jankowski, Łukasz; Rzewuska, Ewa; Dul, Przemysław; Ilnicka, Edyta; Kobylecka, Małgorzata; Pruszczyk, Piotr

2012-01-01

Elevated levels of cardiac troponins are an established method of diagnosis of heart muscle necrosis. A case of a long distance amateur-marathon runner, who showed significant elevation of plasma troponin I after extreme physical effort is reported. The diagnostic examinations did not reveal atherosclerosis burden, but myocardial bridging of coronary artery. The authors describe the significance of the pathology in the view of extreme sport effort performed by the described patient.

Interrelationship of Personality Disorders: Theoretical Formulations and Anecdotal Evidence.

ERIC Educational Resources Information Center

Vincent, Ken R.

1987-01-01

Attempts to define interrelationship of personality disorders. Discusses relationships between and among three major groupings of Diagnostic and Statistical Manual of Mental Disorders. Suggests that passive aggressive, avoidant, and borderline personality disorders serve as bridges between these groupings. Discusses placement within groupings with…

Phase Space Dissimilarity Measures for Structural Health Monitoring

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

Bubacz, Jacob A; Chmielewski, Hana T; Pape, Alexander E

A novel method for structural health monitoring (SHM), known as the Phase Space Dissimilarity Measures (PSDM) approach, is proposed and developed. The patented PSDM approach has already been developed and demonstrated for a variety of equipment and biomedical applications. Here, we investigate SHM of bridges via analysis of time serial accelerometer measurements. This work has four aspects. The first is algorithm scalability, which was found to scale linearly from one processing core to four cores. Second, the same data are analyzed to determine how the use of the PSDM approach affects sensor placement. We found that a relatively low-density placementmore » sufficiently captures the dynamics of the structure. Third, the same data are analyzed by unique combinations of accelerometer axes (vertical, longitudinal, and lateral with respect to the bridge) to determine how the choice of axes affects the analysis. The vertical axis is found to provide satisfactory SHM data. Fourth, statistical methods were investigated to validate the PSDM approach for this application, yielding statistically significant results.« less

Influence of Transplant Center Procedural Volume on Survival Outcomes of Heart Transplantation for Children Bridged with Mechanical Circulatory Support.

PubMed

Hsieh, Alex; Tumin, Dmitry; McConnell, Patrick I; Galantowicz, Mark; Tobias, Joseph D; Hayes, Don

2017-02-01

Transplant center expertise improves survival after heart transplant (HTx) but it is unknown whether center expertise ameliorates risk associated with mechanical circulatory support (MCS) bridge to transplantation. This study investigated whether center HTx volume reduced survival disparities among pediatric HTx patients bridged with extracorporeal membrane oxygenation (ECMO), left ventricular assist device (LVAD), or no MCS. Patients ≤18 years of age receiving first-time HTx between 2005 and 2015 were identified in the United Network of Organ Sharing registry. Center volume was the total number of HTx during the study period, classified into tertiles. The primary outcome was 1 year post-transplant survival, and MCS type was interacted with center volume in Cox proportional hazards regression. The study cohort included 4131 patients, of whom 719 were supported with LVAD and 230 with ECMO. In small centers (≤133 HTx over study period), patients bridged with ECMO had increased post-transplant mortality hazard compared to patients bridged with LVAD (HR 0.29, 95% CI 0.12, 0.71; p = 0.006) and patients with no MCS (HR 0.33, 95% CI 0.19, 0.57; p < 0.001). Interactions of MCS type with medium or large center volume were not statistically significant, and the same differences in survival by MCS type were observed in medium- or large-volume centers (136-208 or ≥214 HTx over the study period). Post-HTx survival disadvantage of pediatric patients bridged with ECMO persisted regardless of transplant program volume. The role of institutional ECMO expertise outside the transplant setting for improving outcomes of ECMO bridge to HTx should be explored.

Development of new polysilsesquioxane spherical particles as stabilized active ingredients for sunscreens

NASA Astrophysics Data System (ADS)

Tolbert, Stephanie Helene

Healthy skin is a sign of positive self-worth, attractiveness and vitality. Compromises to this are frequently caused by extended periods of recreation in the sun and in turn exposure to the harmful effects of UV radiation. To maintain strength and integrity, protection of the skin is paramount. This can be achieved by implementing skin-care products which contain sunscreen active ingredients that provide UV protection. Unfortunately, photo-degradation, toxicity, and photo-allergies limit the effectiveness of present day sunscreen ingredients. Currently, this is moderated by physically embedding within inert silica particles, but leaching of the active ingredient can occur, thereby negating protective efforts. Alternatively, this research details the preparation and investigation of bridged silsesquioxane analogues of commercial ingredients which can be chemically grafted to the silica matrix. Studies with bridged salicylate particles detail facile preparation, minimized leaching, and enhanced UV stability over physically encapsulated and pendant salicylate counterparts. In terms of UVB protective ability, the highest maintenance of sun protection factor (SPF) after extended UV exposure was achieved with bridged incorporation, and has been attributed to corollary UV stability. Additionally, bridged salicylate particles can be classified as broad-spectrum, and rate from moderate to good in terms of UVA protective ability. Particles incorporated with a bridged curcuminoid silsesquioxane were also prepared and displayed comparable results. As such, an attractive method for sunscreen isolation and stabilization has been developed to eliminate the problems associated with current sunscreens, all while maintaining the established UV absorbance profiles of the parent compound. To appreciate the technology utilized in this research, a thorough understanding of sol-gel science as it pertains to hybrid organic/silica particles, including methods of organic fragment incorporation and insight on the effect of incorporation method on ingredient leaching and UV stability, is vital. This was afforded by analysis of hybrid fluorescent dansyl particles, prepared by both O/W microemulsion polymerization and a modified Stober process, which detailed that covalent entrapment of bridged dansyl silsesquioxane is the incorporation method of choice to ensure minimized leaching and enhanced UV stability. As such, use of this method can provide exciting applications in fields where stability and retainment of the embedded ingredient is paramount for efficacy.

Calibration, Data Acquisition, and Post Analysis of Turbulent Fluid Flow in a Calibration Jet Using Hot-wire Anemometry

NASA Technical Reports Server (NTRS)

Moreno, Michelle

2004-01-01

The Turbine Branch concentrates on the following areas: Computational Fluid Dynamics (CFD), and implementing experimental procedures to obtain physical modeling data. Hot-wire Anemometry is a valuable tool for obtaining physical modeling data. Hot-wire Anemometry is likely to remain the principal research tool for most turbulent air/gas flow studies. The Hot-wire anemometer consists of a fine wire heated by electric current. When placed in a fluid stream, the hot-wire loses heat to the fluid by forced convection. In forced convection, energy transfer is due to molecular motion imposed by an extraneous force moving fluid parcels. When the hot-wire is in "equilibrium", the rate of heat input to the wire is equal to the rate of heat loss at the wire ends. The equality between heat input and heat loss is the basis for King s equation, which relates the electrical parameters of the hot-wire to the flow parameters of the fluid. Hot-wire anemometry is based on convective heat transfer from a heated wire element placed in a fluid flow. Any change in the fluid flow condition that affects the heat transfer from the heated element will be detected virtually instantaneously by a constant-temperature Hot-wire anemometry system. The system implemented for this research is the IFA 300. The system is a fully-integrated, thermal anemometer-based system that measures mean and fluctuating velocity components in air, water, and other fluids. It also measures turbulence and makes localized temperature measurements. A constant-temperature anemometer is a bridge and amplifier circuit that controls a tiny wire at constant temperature. As a fluid flow passes over the heated sensor, the amplifier senses the bridge off-balance and adjusts the voltage to the top of the bridge, keeping the bridge in balance. The voltage on top of the bridge can then be related to the velocity of the flow. The bridge voltage is sensitive to temperature as well as velocity and so the built-in thermocouple circuit can be attached to a thermocouple that can measure the fluid temperature. Additional information is included in the original extended abstract.

Curriculum Boosters. Social Studies, Math, Language Arts.

ERIC Educational Resources Information Center

Reissman, Rose; And Others

1994-01-01

Presents three curriculum boosting activities for elementary classes. A social studies activity builds bridges to other cultures via literature. A math activity teaches students about percentages using baseball card statistics. A language arts activity helps students learn to appreciate the language of Shakespeare. A student page presents a…

Assessment and evaluations of I-80 truck loads and their load effects : final report.

DOT National Transportation Integrated Search

2016-12-01

The research objective is to examine the safety of Wyoming bridges on the I-80 corridor considering the actual truck traffic on the : interstate based upon weigh in motion (WIM) data. This was accomplished by performing statistical analyses to determ...

Teaching and physics education research: bridging the gap.

PubMed

Fraser, James M; Timan, Anneke L; Miller, Kelly; Dowd, Jason E; Tucker, Laura; Mazur, Eric

2014-03-01

Physics faculty, experts in evidence-based research, often rely on anecdotal experience to guide their teaching practices. Adoption of research-based instructional strategies is surprisingly low, despite the large body of physics education research (PER) and strong dissemination effort of PER researchers and innovators. Evidence-based PER has validated specific non-traditional teaching practices, but many faculty raise valuable concerns toward their applicability. We address these concerns and identify future studies required to overcome the gap between research and practice.

9th International Workshop on the CKM Unitarity Triangle

NASA Astrophysics Data System (ADS)

The CKM series is a well-established international meeting in the field of quark-flavour physics that brings both experimenters and theorists on a common platform. On the experimental front, we bridge borders between neutron, kaon, charm and beauty hadron, and top quark physics. The theory program tries to cover a wide range of approaches. We shall discuss how this marriage can indirectly probe physics beyond the standard model, taking into account the interplay with high-pT collider searches.

Dust Evolution in Low-Metallicity Environments: Bridging the Gap Between Local Universe and Primordial Galaxies

NASA Astrophysics Data System (ADS)

Galliano, Frederic; Barlow, Mike; Bendo, George; Boselli, Alessandro; Buat, Veronique; Chanial, Pierre; Clements, David; Davies, Jon; Eales, Steve; Gomez, Haley; Isaak, Kate; Madden, Suzanne; Page, Mathew; Perez Fournon, Ismael; Sauvage, Marc; Spinoglio, Luigi; Vaccari, Mattia; Wilson, Christine

2008-03-01

The local galaxy Science Advisory Group (SAG 2) in the Herschel/SPIRE consortium, has constructed a Guaranteed Time Key Program using the PACS and SPIRE insruments to obtain 60 to 550 micron photometry of a statistically significant sample of 51 dwarf galaxies in our local universe chosen to cover an impressivly broad range of physical conditions. Here we propose the necessary complementary IRAC, MIPS and IRS Spitzer observations which together with the Herschel GT database will provide a rich database to the community to perform the dust and gas analyses in unprecedented detail in low metallicity galaxies ranging between 1/50 to 1 solar metallicity. Due to their chemical youth, and to the extreme conditions they experience, low metallicity environments constitute a keystone to understand dust evolution. The primary goal of this combined Herschel and Spitzer project is to study in details the physical processes at play within the ISM of these galaxies. We will take advantage of the powerful combination of Spitzer, Herschel and ancillary data to decompose the SED into the emission coming from the main phases of the ISM. Such a decomposition will provide reliable estimate of the abundances of the principal dust species, as a fonction of metallicity and physical conditions. These results will be exploited to compare the various evolutionary processes affecting the dust content of galaxies. All these outstanding scientific advances will be the true legacy value that this project brings to the community.

A bottom-up approach to urban metabolism: the perspective of BRIDGE

NASA Astrophysics Data System (ADS)

Chrysoulakis, N.; Borrego, C.; San Josè, R.; Grimmond, S. B.; Jones, M. B.; Magliulo, V.; Klostermann, J.; Santamouris, M.

2011-12-01

Urban metabolism considers a city as a system and usually distinguishes between energy and material flows as its components. "Metabolic" studies are usually top-down approaches that assess the inputs and outputs of food, water, energy, and pollutants from a city, or that compare the changing metabolic process of several cities. In contrast, bottom-up approaches are based on quantitative estimates of urban metabolism components at local to regional scales. Such approaches consider the urban metabolism as the 3D exchange and transformation of energy and matter between a city and its environment. The city is considered as a system and the physical flows between this system and its environment are quantitatively estimated. The transformation of landscapes from primarily agricultural and forest uses to urbanized landscapes can greatly modify energy and material exchanges and it is, therefore, an important aspect of an urban area. Here we focus on the exchanges and transformation of energy, water, carbon and pollutants. Recent advances in bio-physical sciences have led to new methods and models to estimate local scale energy, water, carbon and pollutant fluxes. However, there is often poor communication of new knowledge and its implications to end-users, such as planners, architects and engineers. The FP7 Project BRIDGE (SustainaBle uRban plannIng Decision support accountinG for urban mEtabolism) aims at bridging this gap and at illustrating the advantages of considering environmental issues in urban planning. BRIDGE does not perform a complete life cycle analysis or calculate whole system urban metabolism, but rather focuses on specific metabolism components (energy, water, carbon and pollutants). Its main goal is the development of a Decision Suport System (DSS) with the potential to select planning actions which better fit the goal of changing the metabolism of urban systems towards sustainability. BRIDGE evaluates how planning alternatives can modify the physical flows of the above urban metabolism components under consideration in five European cities: Helsinki, Athens, London, Firenze and Gliwice. A Multi-Criteria Evaluation approach has been adopted. To cope with the complexity of urban metabolism issues, objectives are defined in relation to the interactions between the environmental elements (fluxes of energy, water, carbon and pollutants) and socio-economic components (investment costs, housing, employment, etc.) of urban sustainability.

Geometry and Integrability

NASA Astrophysics Data System (ADS)

Mason, Lionel; Nutku, Yavuz

2003-12-01

Based on courses held at the Feza GÜrsey Institute, this collection of survey articles introduces advanced graduate students to an exciting area on the border of mathematics and mathematical physics. Including articles by key names such as Calogero, Donagi and Mason, it features the algebro-geometric material from Donagi as well as the twistor space methods in Woodhouse's contribution, forming a bridge between the pure mathematics and the more physical approaches.

Investigating Approaches to Diversity in a National Survey of Physics Doctoral Degree Programs: The Graduate Admissions Landscape

ERIC Educational Resources Information Center

Potvin, Geoff; Chari, Deepa; Hodapp, Theodore

2017-01-01

Graduate admissions play a critical gatekeeping role in the physics community not only because they select students who are allowed to begin their graduate studies, but also because they influence how students perceive graduate school, and in some cases whether or not they will even choose to apply. In conjunction with the APS Bridge Program, we…

Bridging the Gap -- But Mind You Don't Fall. Primary Physical Education Teachers' Perceptions of the Transition Process to Secondary School

ERIC Educational Resources Information Center

Rainer, Paul; Cropley, Brendan

2015-01-01

Currently there is a large variation in the quality of children's experiences, both across and within primary schools and concerns regarding the quality of physical education (PE) teaching. Significantly, a failure to engage children at this critical time in appropriate high quality PE provision, prior to the transition to secondary education, is…

Emancipation through interaction--how eugenics and statistics converged and diverged.

PubMed

Louçã, Francisco

2009-01-01

The paper discusses the scope and influence of eugenics in defining the scientific programme of statistics and the impact of the evolution of biology on social scientists. It argues that eugenics was instrumental in providing a bridge between sciences, and therefore created both the impulse and the institutions necessary for the birth of modern statistics in its applications first to biology and then to the social sciences. Looking at the question from the point of view of the history of statistics and the social sciences, and mostly concentrating on evidence from the British debates, the paper discusses how these disciplines became emancipated from eugenics precisely because of the inspiration of biology. It also relates how social scientists were fascinated and perplexed by the innovations taking place in statistical theory and practice.

Bridge damage detection using spatiotemporal patterns extracted from dense sensor network

NASA Astrophysics Data System (ADS)

Liu, Chao; Gong, Yongqiang; Laflamme, Simon; Phares, Brent; Sarkar, Soumik

2017-01-01

The alarmingly degrading state of transportation infrastructures combined with their key societal and economic importance calls for automatic condition assessment methods to facilitate smart management of maintenance and repairs. With the advent of ubiquitous sensing and communication capabilities, scalable data-driven approaches is of great interest, as it can utilize large volume of streaming data without requiring detailed physical models that can be inaccurate and computationally expensive to run. Properly designed, a data-driven methodology could enable fast and automatic evaluation of infrastructures, discovery of causal dependencies among various sub-system dynamic responses, and decision making with uncertainties and lack of labeled data. In this work, a spatiotemporal pattern network (STPN) strategy built on symbolic dynamic filtering (SDF) is proposed to explore spatiotemporal behaviors in a bridge network. Data from strain gauges installed on two bridges are generated using finite element simulation for three types of sensor networks from a density perspective (dense, nominal, sparse). Causal relationships among spatially distributed strain data streams are extracted and analyzed for vehicle identification and detection, and for localization of structural degradation in bridges. Multiple case studies show significant capabilities of the proposed approach in: (i) capturing spatiotemporal features to discover causality between bridges (geographically close), (ii) robustness to noise in data for feature extraction, (iii) detecting and localizing damage via comparison of bridge responses to similar vehicle loads, and (iv) implementing real-time health monitoring and decision making work flow for bridge networks. Also, the results demonstrate increased sensitivity in detecting damages and higher reliability in quantifying the damage level with increase in sensor network density.

Polymer concrete overlay test program : interim report.

DOT National Transportation Integrated Search

1974-11-01

This report describes work done on various combinations of monomers and polymer concrete mixes and identifies the mixes showing the greatest potential for use in bridge deck overlays . Presented are test results showing physical properties of various...

Apparatus for Teaching Physics.

ERIC Educational Resources Information Center

Gottlieb, Herbert H., Ed.

1981-01-01

Describes: (1) a variable inductor suitable for an inductance-capacitance bridge consisting of a fixed cylindrical solenoid and a moveable solenoid; (2) long-range apparatus for demonstrating falling bodies; and (3) an apparatus using two lasers to demonstrate ray optics. (SK)

Bridge reliability assessment based on the PDF of long-term monitored extreme strains

NASA Astrophysics Data System (ADS)

Jiao, Meiju; Sun, Limin

2011-04-01

Structural health monitoring (SHM) systems can provide valuable information for the evaluation of bridge performance. As the development and implementation of SHM technology in recent years, the data mining and use has received increasingly attention and interests in civil engineering. Based on the principle of probabilistic and statistics, a reliability approach provides a rational basis for analysis of the randomness in loads and their effects on structures. A novel approach combined SHM systems with reliability method to evaluate the reliability of a cable-stayed bridge instrumented with SHM systems was presented in this paper. In this study, the reliability of the steel girder of the cable-stayed bridge was denoted by failure probability directly instead of reliability index as commonly used. Under the assumption that the probability distributions of the resistance are independent to the responses of structures, a formulation of failure probability was deduced. Then, as a main factor in the formulation, the probability density function (PDF) of the strain at sensor locations based on the monitoring data was evaluated and verified. That Donghai Bridge was taken as an example for the application of the proposed approach followed. In the case study, 4 years' monitoring data since the operation of the SHM systems was processed, and the reliability assessment results were discussed. Finally, the sensitivity and accuracy of the novel approach compared with FORM was discussed.

Fracturing ranked surfaces

NASA Astrophysics Data System (ADS)

Schrenk, K. J.; Araújo, N. A. M.; Andrade, J. S., Jr.; Herrmann, H. J.

2012-04-01

Discretized landscapes can be mapped onto ranked surfaces, where every element (site or bond) has a unique rank associated with its corresponding relative height. By sequentially allocating these elements according to their ranks and systematically preventing the occupation of bridges, namely elements that, if occupied, would provide global connectivity, we disclose that bridges hide a new tricritical point at an occupation fraction p = pc, where pc is the percolation threshold of random percolation. For any value of p in the interval pc < p <= 1, our results show that the set of bridges has a fractal dimension dBB ~ 1.22 in two dimensions. In the limit p --> 1, a self-similar fracture is revealed as a singly connected line that divides the system in two domains. We then unveil how several seemingly unrelated physical models tumble into the same universality class and also present results for higher dimensions.

Tunneling from the past horizon

NASA Astrophysics Data System (ADS)

Kang, Subeom; Yeom, Dong-han

2018-04-01

We investigate a tunneling and emission process of a thin-shell from a Schwarzschild black hole, where the shell was initially located beyond the Einstein-Rosen bridge and finally appears at the right side of the Penrose diagram. In order to obtain such a solution, we should assume that the areal radius of the black hole horizon increases after the tunneling. Hence, there is a parameter range such that the tunneling rate is exponentially enhanced, rather than suppressed. We may have two interpretations regarding this. First, such a tunneling process from the past horizon is improbable by physical reasons; second, such a tunneling is possible in principle, but in order to obtain a stable Einstein-Rosen bridge, one needs to restrict the parameter spaces. If such a process is allowed, this can be a nonperturbative contribution to Einstein-Rosen bridges as well as eternal black holes.

Skin bridging secondary to ingrown toenail

PubMed Central

Dadaci, Mehmet; Ince, Bilsev; Altuntas, Zeynep; Kamburoglu, Haldun Onuralp; Bitik, Ozan

2014-01-01

Ingrown toenails are painful conditions that especially affect young people and may become chronic if not treated. We describe a case of chronically inflamed ingrown toenail left untreated for three years. In the physical examination, skin bridging and epithelialization was observed in midline secondary to soft tissue hypertrophy of the lateral nail matrixes. Epithelized fibrous tissue was cut across the lateral nail matrix and left for secondary healing. Partial matrixectomy was applied and the remnants were cauterized in compliance with the Winograd procedure after removal of the nail. Our case is an advanced condition which is the second report in the literature. Skin bridging secondary to excess soft tissue hypertrophy can be observed in untreated bilateral Heinfert or Frost stage 3 ingrown nails. This rare case can be classified as advanced stage 3 disease or stage 4. PMID:25674152

Digimarc MediaBridge: the birth of a consumer product from concept to commercial application

NASA Astrophysics Data System (ADS)

Perry, Burt; MacIntosh, Brian; Cushman, David

2002-04-01

This paper examines the issues encountered in the development and commercial deployment of a system based on digital watermarking technology. The paper provides an overview of the development of digital watermarking technology and the first applications to use the technology. It also looks at how we took the concept of digital watermarking as a communications channel within a digital environment and applied it to the physical print world to produce the Digimarc MediaBridge product. We describe the engineering tradeoffs that were made to balance competing requirements of watermark robustness, image quality, embedding process, detection speed and end user ease of use. Today, the Digimarc MediaBridge product links printed materials to auxiliary information about the content, via the Internet, to provide enhanced informational marketing, promotion, advertising and commerce opportunities.

Merging Mathematics and English: One Approach to Bridging the Disciplines.

ERIC Educational Resources Information Center

Hansbarger, J. Clark; Stewart, Eric Lane

1996-01-01

Discusses two six-week projects for high school students involving qualitative and quantitative research methods to integrate mathematics and English. Students use descriptive statistics and prose to present findings about (1) their school space and (2) daily life for American troops in the Gulf War. (KMC)

Bridging Ends to Means: Achieving a Viable Peace in Afghanistan

DTIC Science & Technology

2010-04-01

the Global War on Terror. No price should be too high to guarantee national security; yet, as the statistics suggest, the fiscal situation has...Studies AY10 Coursebook , edited by Sharon McBride, 351-356. Maxwell AFB, AL: Air University Press, October 2009. Saikal, Amin. Modern Afghanistan

Estimating Peak-Flow Frequency Statistics for Selected Gaged and Ungaged Sites in Naturally Flowing Streams and Rivers in Idaho

DOT National Transportation Integrated Search

2017-03-01

Reliable estimates of the magnitude and frequency of floods are needed by Federal, regional, State, and local infrastructure designers and water-resource managers for the design of highway, road, and other bridge crossings of rivers, delineation of f...

Portable Classrooms: Immediate Solutions to a "Growing" Problem

ERIC Educational Resources Information Center

Patterson, Judith; Chandler, Mary; Jiang, Binbin; Chan, T. C.

2009-01-01

In 1999, 36% of schools reported that they used portable classrooms and 20% reported that they created temporary instructional spaces, according to the National Center for Education Statistics. Portable classrooms will most certainly continue to be used temporarily to bridge the gap between immediate need and availability of construction funding.…

Electrostatic Solvation Energy for Two Oppositely Charged Ions in a Solvated Protein System: Salt Bridges Can Stabilize Proteins

PubMed Central

Gong, Haipeng; Freed, Karl F.

2010-01-01

Abstract Born-type electrostatic continuum methods have been an indispensable ingredient in a variety of implicit-solvent methods that reduce computational effort by orders of magnitude compared to explicit-solvent MD simulations and thus enable treatment using larger systems and/or longer times. An analysis of the limitations and failures of the Born approaches serves as a guide for fundamental improvements without diminishing the importance of prior works. One of the major limitations of the Born theory is the lack of a liquidlike description of the response of solvent dipoles to the electrostatic field of the solute and the changes therein, a feature contained in the continuum Langevin-Debye (LD) model applied here to investigate how Coulombic interactions depend on the location of charges relative to the protein/water boundary. This physically more realistic LD model is applied to study the stability of salt bridges. When compared head to head using the same (independently measurable) physical parameters (radii, dielectric constants, etc.), the LD model is in good agreement with observations, whereas the Born model is grossly in error. Our calculations also suggest that a salt bridge on the protein's surface can be stabilizing when the charge separation is ≤4 Å. PMID:20141761

REVIEW ARTICLE: The physics of biological molecular motors

NASA Astrophysics Data System (ADS)

Thomas, N.; Thornhill, R. A.

1998-02-01

Molecular motors are the fundamental agents of movement in living organisms. A prime example is the actomyosin motor that powers muscle contraction. We illustrate the remarkable physics of this motor using a simplified three-state model, in which a myosin cross-bridge attaches to an actin filament, tilts over and then detaches. This `cross-bridge cycle', driven by ATP hydrolysis, is similar to a thermodynamic cycle, except that the molecular system is stochastic. Random transitions in the cycle therefore produce tension fluctuations, which have recently been observed in single-molecule experiments. Furthermore, since the rate constants for attachment and tilting depend on the elastic energy in the cross-bridge spring, the molecular motor is a highly nonlinear mechanical system. A bias tension `stretch activates' the motor, and it then develops the remarkable property of `negative viscosity', which allows it to perform as a self-sustained mechanical oscillator. However, when a series of attachment sites is available, the motor operates instead as a ratchet, pulling the actin filament rapidly forwards against a light load, whilst a heavy load pulls the filament only very slowly in the opposite direction. Similar ideas may apply to the dynein-tubulin motor that powers cilia and flagella and the kinesin-tubulin motor used in intracellular transport.

TinyONet: A Cache-Based Sensor Network Bridge Enabling Sensing Data Reusability and Customized Wireless Sensor Network Services

PubMed Central

Jung, Eui-Hyun; Park, Yong-Jin

2008-01-01

In recent years, a few protocol bridge research projects have been announced to enable a seamless integration of Wireless Sensor Networks (WSNs) with the TCP/IP network. These studies have ensured the transparent end-to-end communication between two network sides in the node-centric manner. Researchers expect this integration will trigger the development of various application domains. However, prior research projects have not fully explored some essential features for WSNs, especially the reusability of sensing data and the data-centric communication. To resolve these issues, we suggested a new protocol bridge system named TinyONet. In TinyONet, virtual sensors play roles as virtual counterparts of physical sensors and they dynamically group to make a functional entity, Slice. Instead of direct interaction with individual physical sensors, each sensor application uses its own WSN service provided by Slices. If a new kind of service is required in TinyONet, the corresponding function can be dynamically added at runtime. Beside the data-centric communication, it also supports the node-centric communication and the synchronous access. In order to show the effectiveness of the system, we implemented TinyONet on an embedded Linux machine and evaluated it with several experimental scenarios. PMID:27873968

Statistical innovations in the medical device world sparked by the FDA.

PubMed

Campbell, Gregory; Yue, Lilly Q

2016-01-01

The world of medical devices while highly diverse is extremely innovative, and this facilitates the adoption of innovative statistical techniques. Statisticians in the Center for Devices and Radiological Health (CDRH) at the Food and Drug Administration (FDA) have provided leadership in implementing statistical innovations. The innovations discussed include: the incorporation of Bayesian methods in clinical trials, adaptive designs, the use and development of propensity score methodology in the design and analysis of non-randomized observational studies, the use of tipping-point analysis for missing data, techniques for diagnostic test evaluation, bridging studies for companion diagnostic tests, quantitative benefit-risk decisions, and patient preference studies.

The Vector Magnetic Fields and Thermodynamics of Sunspot Light Bridges: The Case for Field-free Disruptions in Sunspots

NASA Astrophysics Data System (ADS)

Leka, K. D.

1997-07-01

We present observations with the Advanced Stokes Polarimeter of 11 light bridges in sunspots of various ages and sizes, all very close to disk center. Full vector spectropolarimetry and a nonlinear least-squares inversion algorithm allows us to determine not only the vector magnetic field in the bridges and host sunspots but also thermodynamic parameters such as continuum brightness, Doppler shifts, Doppler widths, opacity ratio, and the source function parameters. We can also separate the magnetic and nonmagnetic components of the spectral signal within each resolution element. We find that there is a disruption of the magnetic fields in light bridges, relative both to neighboring umbrae and to normal, undisturbed penumbrae. This change takes the form of lower intrinsic field strength and sparser, more horizontal fields in the bridges relative to umbrae. The magnetic fields in the bridges remain more vertically oriented, however, than those in undisturbed penumbra. There are systematic upflows observed in the bridge plasma relative to the neighboring umbrae, and the evidence points toward a component that is heated and departs from radiative equilibrium. In four cases, we follow a light bridge over several days and find that as the bridges age, they grow wider and brighter, the fields weaken and become sparser, and the heating increases. We also find some evidence that the magnetic field begins to reorganize itself to accommodate the (now) two azimuth centers before there are strong signals of a light bridge in the thermodynamic parameters. This paper presents the first systematic look at sunspot light bridges with full vector polarimetry and thermodynamic determination. The results show that there is an intrusion of field-free, possibly convective material into an otherwise stable, magnetic sunspot. The departure from stability is seen in the magnetic field orientation prior to its appearance in continuum intensity, and the effects of this disruption are evident beyond the immediate umbral intrusion. The results do not unambiguously determine the physical mechanism that makes sunspots disappear. However, it strongly points toward a ropelike magnetic structure through which convection may penetrate when the magnetic fibrils separate or around which field-free plasma may flow. The appearance of field-free heated material is likely an effect, not the cause, of the sunspot light bridges.

Experimental study on spatio-temporal behavior of a single particle forming a particle accumulation structure (PAS) in half-zone liquid bridge

NASA Astrophysics Data System (ADS)

Oba, Takeru; Ueno, Ichiro; Kaneko, Toshihiro

2017-11-01

We focus on particle behavior due to thermocapillary-driven convection in a half-zone liquid bridge of high-Prandtl number fluid. It has been known that the suspended particles exhibit a unique solid-like structure known as 'particle accumulation structure (PAS)' in a rotating frame of reference with traveling-type hydrothermal wave. It is said that PAS is caused by interaction between particles and the free surface of a half-zone liquid bridge. Such structures arise even under small Stokes number conditions. When observing PAS two-dimensionally, it looks like a closed single string, but the actual movement of particles is different. Therefore we employ three-dimensional particle tracking velocimetry to the half-zone liquid bridge of 2.5 mm in radius and 1.7 mm in height, and detect the particle behaviors close to the free surface. We explain the spatio-temporal correlation between the solid-like global structure of PAS and the local particle motions, and make comparisons with proposed physical models of PAS formation.

An embedded wireless system for remote monitoring of bridges

NASA Astrophysics Data System (ADS)

Harms, T.; Bastianini, F.; Sedigh Sarvestani, S.

2008-03-01

This paper describes an autonomous embedded system for remote monitoring of bridges. Salient features of the system include ultra-low power consumption, wireless communication of data and alerts, and incorporation of embedded sensors that monitor various indicators of the structural health of a bridge, while capturing the state of its surrounding environment. Examples include water level, temperature, vibration, and acoustic emissions. Ease of installation, physical robustness, remote maintenance and calibration, and autonomous data communication make the device a self-contained solution for remote monitoring of structural health. The system addresses shortcomings present in centralized structural health monitoring systems, particularly their reliance on a laptop or handheld computer. The system has been field-tested to verify the accuracy of the collected data and dependability of communication. The sheer volume of data collected, and the regularity of its collection can enable accurate and precise assessment of the health of a bridge, guiding maintenance efforts and providing early warning of potentially dangerous events. In this paper, we present a detailed breakdown of the system's power requirements and the results of the initial field test.

Physics of the violin

NASA Astrophysics Data System (ADS)

Jansson, Erik V.

2003-10-01

A method to measure acoustical properties of the violin has been developed. The bridge is excited by an impulse force hammer (see www.speech.kth.se/music/acviguit4). Bridge vibrations are recorded by a small magnet and an electrical coil. Measurements can be made in an ordinary room and give a record of properties built into the violin body. An old good Polish violin, B Dankwart, Vilnius ca. 1600 shows typical results with peaks P1, P2 and the BH-hill. Our goal is as suggested by Gabriel Weinreich ``to understand, not to copy,''-Stradivarius. By shifting the soundpost position the peaks P1, P2 and BH can be somewhat monitored. It can be shown that the BH is not confined to the bridge only. The feet distance of the bridge is important but also the top plate. Marcin Groblicz, the great Polish violin maker, was court instrument maker in Krakow ca. 1600 to Sigismund, King of Poland and Sweden. I believe Gabriel Weinreich has some connection to Vilnius in Poland but unfortunately not to Sweden. We like Gabi.

Work activities and musculoskeletal discomforts amongst active older Albertans on alternative employment trajectories.

PubMed

Doan, Jon B; Copeland, Jennifer L; Brown, Lesley A; Newman, Jeff T; Hudson, D Shane

2014-01-01

Bridge employment (scheduled paid work after retirement age) may promote successful aging and continued health, as work can be an important component of daily physical activity. Appropriate work demands for older adults are neither well-established nor well-applied, however, and excessive loading or increased perceptions of discomfort may negate the health benefits of work activity. This study examined work status and musculoskeletal discomfort (MSD) amongst older Albertans. 1044 Albertans aged 55 years and older participating in an organized 'Games' received a research package. Enclosed in the package were an introductory letter, a return envelope, and modified versions of validated questionnaires examining leisure and work activities, activity frequency, and perceptions of musculoskeletal health. 228 respondents were classified into one of three employment trajectory groups: fully retired, fully employed, or bridge employed. Groups differed in age, and both employed groups more frequently reported MSDs in all body areas. Bridge employed reported increased 'occasional' frequency of musculoskeletal injury risk factors, while both groups reported similar overall ratings of work-related exertion. The increased MSDs reported by bridge employed adults may be the result of irregularity of work activity and soft tissue loading. Detailed examination of work demands and musculoskeletal injuries amongst bridge employed adults could help define safer levels for less regular work activity.

Foraging ants trade off further for faster: use of natural bridges and trunk trail permanency in carpenter ants

NASA Astrophysics Data System (ADS)

Loreto, Raquel G.; Hart, Adam G.; Pereira, Thairine M.; Freitas, Mayara L. R.; Hughes, David P.; Elliot, Simon L.

2013-10-01

Trail-making ants lay pheromones on the substrate to define paths between foraging areas and the nest. Combined with the chemistry of these pheromone trails and the physics of evaporation, trail-laying and trail-following behaviours provide ant colonies with the quickest routes to food. In relatively uniform environments, such as that provided in many laboratory studies of trail-making ants, the quickest route is also often the shortest route. Here, we show that carpenter ants ( Camponotus rufipes), in natural conditions, are able to make use of apparent obstacles in their environment to assist in finding the fastest routes to food. These ants make extensive use of fallen branches, twigs and lianas as bridges to build their trails. These bridges make trails significantly longer than their straight line equivalents across the forest floor, but we estimate that ants spend less than half the time to reach the same point, due to increased carriage speed across the bridges. We also found that these trails, mainly composed of bridges, are maintained for months, so they can be characterized as trunk trails. We suggest that pheromone-based foraging trail networks in field conditions are likely to be structured by a range of potentially complex factors but that even then, speed remains the most important consideration.

Elements of an integrated health monitoring framework

NASA Astrophysics Data System (ADS)

Fraser, Michael; Elgamal, Ahmed; Conte, Joel P.; Masri, Sami; Fountain, Tony; Gupta, Amarnath; Trivedi, Mohan; El Zarki, Magda

2003-07-01

Internet technologies are increasingly facilitating real-time monitoring of Bridges and Highways. The advances in wireless communications for instance, are allowing practical deployments for large extended systems. Sensor data, including video signals, can be used for long-term condition assessment, traffic-load regulation, emergency response, and seismic safety applications. Computer-based automated signal-analysis algorithms routinely process the incoming data and determine anomalies based on pre-defined response thresholds and more involved signal analysis techniques. Upon authentication, appropriate action may be authorized for maintenance, early warning, and/or emergency response. In such a strategy, data from thousands of sensors can be analyzed with near real-time and long-term assessment and decision-making implications. Addressing the above, a flexible and scalable (e.g., for an entire Highway system, or portfolio of Networked Civil Infrastructure) software architecture/framework is being developed and implemented. This framework will network and integrate real-time heterogeneous sensor data, database and archiving systems, computer vision, data analysis and interpretation, physics-based numerical simulation of complex structural systems, visualization, reliability & risk analysis, and rational statistical decision-making procedures. Thus, within this framework, data is converted into information, information into knowledge, and knowledge into decision at the end of the pipeline. Such a decision-support system contributes to the vitality of our economy, as rehabilitation, renewal, replacement, and/or maintenance of this infrastructure are estimated to require expenditures in the Trillion-dollar range nationwide, including issues of Homeland security and natural disaster mitigation. A pilot website (http://bridge.ucsd.edu/compositedeck.html) currently depicts some basic elements of the envisioned integrated health monitoring analysis framework.

Neural Network Technique for Global Ocean Color (Chl-a) Estimates Bridging Multiple Satellite Missions

NASA Astrophysics Data System (ADS)

Garraffo, Z. D.; Nadiga, S.; Krasnopolsky, V.; Mehra, A.; Bayler, E. J.; Kim, H. C.; Behringer, D.

2016-02-01

A Neural Network (NN) technique is used to produce consistent global ocean color estimates, bridging multiple satellite ocean color missions by linking ocean color variability - primarily driven by biological processes - with the physical processes of the upper ocean. Satellite-derived surface variables - sea-surface temperature (SST) and sea-surface height (SSH) fields - are used as signatures of upper-ocean dynamics. The NN technique employs adaptive weights that are tuned by applying statistical learning (training) algorithms to past data sets, providing robustness with respect to random noise, accuracy, fast emulations, and fault-tolerance. This study employs Sea-viewing Wide Field-of-View Sensor (SeaWiFS) chlorophyll-a data for 1998-2010 in conjunction with satellite SSH and SST fields. After interpolating all data sets to the same two-degree latitude-longitude grid, the annual mean was removed and monthly anomalies extracted . The NN technique wass trained for even years of that period and tested for errors and bias for the odd years. The NN output are assessed for: (i) bias, (ii) variability, (iii) root-mean-square error (RMSE), and (iv) cross-correlation. A Jacobian is evaluated to estimate the impact of each input (SSH, SST) on the NN chlorophyll-a estimates. The differences between an ensemble of NNs vs a single NN are examined. After the NN is trained for the SeaWiFS period, the NN is then applied and validated for 2005-2015, a period covered by other satellite missions — the Moderate Resolution Imaging Spectroradiometer (MODIS AQUA) and the Visible Imaging Infrared Radiometer Suite (VIIRS).

Bridging the Gap: research informing practice and policy for healthy youth behavior.

PubMed

Chaloupka, Frank J; Johnston, Lloyd D

2007-10-01

Bridging the Gap (BTG) is a collaborative research initiative supported by the Robert Wood Johnson Foundation. Ten years ago, BTG was created to assess the impact of policies, programs, and other environmental influences on adolescent alcohol, tobacco, and illicit drug use and related outcomes. This multidisciplinary, multisite initiative examines these factors at multiple levels of social organization, including schools, communities, and states. More recently, the significant increases in obesity among children, adolescents, and adults led BTG to expand its efforts to include research on the role of policies, programs, and other factors on adolescent obesity and the physical inactivity and dietary habits that contribute to this growing problem. Eleven papers resulting from BTG's obesity-related research are contained in this supplement, along with two papers describing the National Cancer Institute-supported efforts to track relevant state policies. Bridging the Gap involves a variety of data-collection efforts built largely around the Monitoring the Future (MTF) surveys of 8th-, 10th-, and 12th-grade students. These include: surveys of administrators in the MTF schools that gather extensive information on the school food environment, physical education in schools, and other relevant information; collection of contextual information from the communities in which the MTF schools are located; tracking of relevant state policies; and gathering of a wide variety of data from archival and commercial databases. These databases are analyzed individually and in various combinations. Bridging the Gap's extensive research has shown the importance of a range of school, community, state, and other influences in affecting adolescent substance use and related outcomes. BTG's early research on adolescent diet, physical activity, and obesity--much of which is contained in this supplement--similarly demonstrates the role of environmental factors in influencing these outcomes and in explaining observed racial/ethnic and socioeconomic-related disparities in them. The growing recognition of the public health and economic consequences of childhood, adolescent, and adult obesity has led to a variety of policies, programs, and other interventions to stimulate healthy eating and physical activity, often despite the lack of evidence on their impact. BTG and others are working to build the evidence base for effective interventions to address this significant problem, but much remains to be learned.

The physics of symbols: bridging the epistemic cut.

PubMed

Pattee, H H

2001-01-01

Evolution requires the genotype-phenotype distinction, a primeval epistemic cut that separates energy-degenerate, rate-independent genetic symbols from the rate-dependent dynamics of construction that they control. This symbol-matter or subject-object distinction occurs at all higher levels where symbols are related to a referent by an arbitrary code. The converse of control is measurement in which a rate-dependent dynamical state is coded into quiescent symbols. Non-integrable constraints are one necessary condition for bridging the epistemic cut by measurement, control, and coding. Additional properties of heteropolymer constraints are necessary for biological evolution.

Archimedes meets Einstein: a millennial geometric bridge

NASA Astrophysics Data System (ADS)

Prado, Xabier; Area, Iván; Paredes, Angel; Domínguez Castiñeiras, José Manuel; Edelstein, José D.; Mira, Jorge

2018-07-01

This contribution explores some analogies between special relativity and geometrical tools developed by the ancient Greeks. The kinematics of one-dimensional elastic collisions is solved with simple ruler-and-compass constructions on conic sections. Then, a thought-provoking relation involving Lorentz transformations, Archimedes’ law of the lever and Einstein’s formula for the relativistic mass is put forward. The familiarity with classical geometry is useful in developing intuitions on deep concepts of modern physics and can be profitable for high school or basic undergraduate teaching. Moreover, it is fascinating to establish a bridge connecting beautiful ideas separated by two millennia.

Role of paediatric assist device in bridge to transplant

PubMed Central

Hetzer, Roland; Javier, Mariano Francisco del Maria

2018-01-01

Background While heart transplantation has gained recognition as the gold standard therapy for advanced heart failure, the scarcity of donor organs has become an important concern. The evolution of surgical alternatives such as ventricular assist devices (VADs), allow for recovery of the myocardium and ensure patient survival until heart transplantation becomes possible. This report elaborates the role of VADs as a bridge to heart transplantation in infants and children (≤18 years old) with end-stage heart failure. Methods A retrospective review of the medical records of 201 heart transplant recipients between May 1986 and September 2014 identified 78 children [38.8%; mean age 7.2 (7.8±6.0) years old; IQR: 2.6–11.8 years] with advanced heart failure who were supported with a VAD [left VAD (LVAD) =21; biventricular VAD (BVAD) =57] as a bridge to heart transplantation. Fourteen (17.9%) patients were less than 1 year old; 15 (19.2%) children had a cardiac arrest and underwent cardiopulmonary resuscitation, with 7 of these patients also requiring extracorporeal membrane oxygenation (ECMO) support prior to implantation of a VAD. The aetiology of heart failure was primarily cardiomyopathy (dilative, restrictive from endocardial fibrosis, idiopathic or toxic-induced), reported in 56 (71.8%) patients. The VADs employed were primarily Berlin Heart EXCOR® (n=63), HeartWare (n=13), Berlin Heart INCOR® (n=1), and Toyobo (n=1). Results Mean duration of VAD support was 59 (133.37±191.57) days (range, 1–945 days; IQR: 23–133 days) before a donor heart became available. The primary complication encountered while patients were being bridged to transplant was mediastinal bleeding (7.8%). The main indication for pump exchanges was thrombus formation in the valves. There was no incidence of technical failure of the blood pump or driving system components. Skin infections around the cannulae occurred in 2.5%. Adverse neurological symptoms (thromboembolism 11.1%, cerebral haemorrhage 3.6%) that occurred did not have any permanent neurological sequelae that could be detected on clinical examination in this study. Mean duration of follow-up was 9.4 (10.3±7.6) years (IQR: 3.74–15.14 years). Cumulative survival rates of patients bridged to transplantation with VAD were 93.6%±2.8%, 84.6%±4.1%, 79.1%±4.7%, 63.8%±6.2%, 61.6%±7.1%, and 52.1%±9.3% at 30 days, 1, 5, 10, 15 and 20 years, respectively. There was no statistically significant difference (P=0.79) in survival rates of patients bridged to heart transplantation with VAD compared to those who underwent primary heart transplantation. Post-transplant survival rates stratified according to the type of VAD implanted and number of ventricles supported were not statistically different (P=0.93 and 0.73, respectively). In addition, post-transplant survival rates were not significantly different when age, gender and diagnosis were adjusted for. Furthermore, no statistically significant difference was found when post-transplant survival rates of children who had episodes of rejection were compared to those who did not have episodes of rejection. Conclusions The results in this series demonstrate that VADs satisfactorily support paediatric patients with advanced heart failure from a variety of aetiologies until heart transplantation. The data further suggests that patients bridged with VADs have comparable long-term post-transplant survival as those undergoing primary heart transplantation. PMID:29492386

Nuclear Physics Review

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

Walker-Loud, Andre

2014-11-01

Anchoring low-energy nuclear physics to the fundamental theory of strong interactions remains an outstanding challenge. I review the current progress and challenges of the endeavor to use lattice QCD to bridge this connection. This is a particularly exciting time for this line of research as demonstrated by the spike in the number of different collaborative efforts focussed on this problem and presented at this conference. I first digress and discuss the 2013 Ken Wilson Award.

Brokering and Bridging Knowledge in Health and Physical Education: A Critical Discourse Analysis of One External Provider's Curriculum

ERIC Educational Resources Information Center

Sperka, Leigh; Enright, Eimear; McCuaig, Louise

2018-01-01

Background: There has been a proliferation of external agencies 'knocking on the door' of, and being welcomed into, Health and Physical Education (HPE). This opens HPE up to new products, partners, and services. Although scholarship on the practice of outsourcing HPE is steadily growing in quantity and in scope, there is a significant gap in the…

The effect of rotational isomerism on the first hyperpolarizability of chromophores with divinyl quinoxaline conjugated bridge

NASA Astrophysics Data System (ADS)

Levitskaya, A. I.; Kalinin, A. A.; Fominykh, O. D.; Balakina, M. Yu.

2017-08-01

The effect of rotational isomerism on the values of first hyperpolarizability is studied by the example of two chromophores 7-DMA-VQV-TCP and 3-DMA-VQonV-TCP with quinoxaline and quinoxalinone moieties in the π-electron bridge. At the isomers formation the rotations about three single bonds are considered, thus providing eight possible conformers for each chromophore. The analysis of the results of DFT calculations demonstrates the presence of one lowest-energy conformer characterized by dominating probability for each chromophore. The calculations show that for both chromophores all rotational isomers are characterized by the first hyperpolarizability values rather close (within 8% and 11%) to statistically averaged ones.

Autoregressive statistical pattern recognition algorithms for damage detection in civil structures

NASA Astrophysics Data System (ADS)

Yao, Ruigen; Pakzad, Shamim N.

2012-08-01

Statistical pattern recognition has recently emerged as a promising set of complementary methods to system identification for automatic structural damage assessment. Its essence is to use well-known concepts in statistics for boundary definition of different pattern classes, such as those for damaged and undamaged structures. In this paper, several statistical pattern recognition algorithms using autoregressive models, including statistical control charts and hypothesis testing, are reviewed as potentially competitive damage detection techniques. To enhance the performance of statistical methods, new feature extraction techniques using model spectra and residual autocorrelation, together with resampling-based threshold construction methods, are proposed. Subsequently, simulated acceleration data from a multi degree-of-freedom system is generated to test and compare the efficiency of the existing and proposed algorithms. Data from laboratory experiments conducted on a truss and a large-scale bridge slab model are then used to further validate the damage detection methods and demonstrate the superior performance of proposed algorithms.

Statistical analysis of modal parameters of a suspension bridge based on Bayesian spectral density approach and SHM data

NASA Astrophysics Data System (ADS)

Li, Zhijun; Feng, Maria Q.; Luo, Longxi; Feng, Dongming; Xu, Xiuli

2018-01-01

Uncertainty of modal parameters estimation appear in structural health monitoring (SHM) practice of civil engineering to quite some significant extent due to environmental influences and modeling errors. Reasonable methodologies are needed for processing the uncertainty. Bayesian inference can provide a promising and feasible identification solution for the purpose of SHM. However, there are relatively few researches on the application of Bayesian spectral method in the modal identification using SHM data sets. To extract modal parameters from large data sets collected by SHM system, the Bayesian spectral density algorithm was applied to address the uncertainty of mode extraction from output-only response of a long-span suspension bridge. The posterior most possible values of modal parameters and their uncertainties were estimated through Bayesian inference. A long-term variation and statistical analysis was performed using the sensor data sets collected from the SHM system of the suspension bridge over a one-year period. The t location-scale distribution was shown to be a better candidate function for frequencies of lower modes. On the other hand, the burr distribution provided the best fitting to the higher modes which are sensitive to the temperature. In addition, wind-induced variation of modal parameters was also investigated. It was observed that both the damping ratios and modal forces increased during the period of typhoon excitations. Meanwhile, the modal damping ratios exhibit significant correlation with the spectral intensities of the corresponding modal forces.

Development and field application of a nonlinear ultrasonic modulation technique for fatigue crack detection without reference data from an intact condition

NASA Astrophysics Data System (ADS)

Lim, Hyung Jin; Kim, Yongtak; Koo, Gunhee; Yang, Suyoung; Sohn, Hoon; Bae, In-hwan; Jang, Jeong-Hwan

2016-09-01

In this study, a fatigue crack detection technique, which detects a fatigue crack without relying on any reference data obtained from the intact condition of a target structure, is developed using nonlinear ultrasonic modulation and applied to a real bridge structure. Using two wafer-type lead zirconate titanate (PZT) transducers, ultrasonic excitations at two distinctive frequencies are applied to a target inspection spot and the corresponding ultrasonic response is measured by another PZT transducer. Then, the nonlinear modulation components produced by a breathing-crack are extracted from the measured ultrasonic response, and a statistical classifier, which can determine if the nonlinear modulation components are statistically significant in comparison with the background noise level, is proposed. The effectiveness of the proposed fatigue crack detection technique is experimentally validated using the data obtained from aluminum plates and aircraft fitting-lug specimens under varying temperature and loading conditions, and through a field testing of Yeongjong Grand Bridge in South Korea. The uniqueness of this study lies in that (1) detection of a micro fatigue crack with less than 1 μm width and fatigue cracks in the range of 10-20 μm in width using nonlinear ultrasonic modulation, (2) automated detection of fatigue crack formation without using reference data obtained from an intact condition, (3) reliable and robust diagnosis under varying temperature and loading conditions, (4) application of a local fatigue crack detection technique to online monitoring of a real bridge.

The influence of the guided constructivist instructional model on attitudes toward secondary-level physics

NASA Astrophysics Data System (ADS)

Dallal, Kamel Salim

The effect of guided constructivism (bridging analogies) and expository instructional methods on the attitudes of students toward physics was investigated. A nonrandomize nonequivalent pretest-posttest control group quasi- experimental design was employed. The sample consisted of 127 eleventh-grade and twelfth-grade students from five selected classes from two private high schools in Beirut, Lebanon. Two intact classes were assigned to the control group and three classes to the experimental group. The experimental group was exposed to the bridging analogies instructional method, and the control group was taught using the traditional expository method. A Likert-type instrument, the Physics Attitude Index, was used to measure attitudes on four dimensions. The 40-item Physics Attitude Index (PAI) is a questionnaire using a five response scale. Performance in the assigned topics in physics, cognitive developmental levels, and gender were used as covariants and to examine interaction effects. The experimental groups had significantly higher means than the control groups on all criterion variables. A significant interaction was found between groups and performance levels in the following cases: (a) criterion variable of attitude toward physics; (b) views toward physics learning; and (c) enjoyment of physics. This result indicated that the low performing students among the experimental group had greater gain in attitude toward physics than the high performing students in same group. On the other hand, no interaction occurred between treatment groups and gender, which shows that in this study gender has no significant effect on attitude toward physics. Significant interactions between the treatment groups and cognitive levels were found on the criterion variable of beliefs about physics as a process of learning and enjoyment of physics. In both cases, the difference between the group means were widely different among students at the concrete and transitional levels, but narrowly different among students at the formal level.

Exciton interference revealed by energy dependent exciton transfer rate for ring-structured molecular systems.

PubMed

Yan, Yun-An

2016-01-14

The quantum interference is an intrinsic phenomenon in quantum physics for photon and massive quantum particles. In principle, the quantum interference may also occur with quasi-particles, such as the exciton. In this study, we show how the exciton quantum interference can be significant in aggregates through theoretical simulations with hierarchical equations of motion. The systems under investigation are generalized donor-bridge-acceptor model aggregates with the donor consisting of six homogeneous sites assuming the nearest neighbor coupling. For the models with single-path bridge, the exciton transfer time only shows a weak excitation energy dependence. But models with double-path bridge have a new short transfer time scale and the excitation energy dependence of the exciton transfer time assumes clear peak structure which is detectable with today's nonlinear spectroscopy. This abnormality is attributed to the exciton quantum interference and the condition for a clear observation in experiment is also explored.

Executive edition : New Jersey I-80 and I-287 HOV lane case study

DOT National Transportation Integrated Search

2000-05-01

The report provides the American people with a national perspective on the physical and operating characteristics of the highway, bridge, and transit portions of the nation's intermodal transportation system. It offers a comprehensive, factual backgr...

Image processing, analysis, and management tools for gusset plate connections in steel truss bridges.

DOT National Transportation Integrated Search

2016-10-01

This report details the research undertaken and software tools that were developed that enable digital : images of gusset plates to be converted into orthophotos, establish physical dimensions, collect : geometric information from them, and conduct s...

The Deformation of Overburden Soil and Interaction with Pile Foundations of Bridges Induced by Normal Faulting

NASA Astrophysics Data System (ADS)

Wu, Liang-Chun; Li, Chien-Hung; Chan, Pei-Chen; Lin, Ming-Lang

2017-04-01

According to the investigations of well-known disastrous earthquakes in recent years, ground deformation induced by faulting is one of the causes for engineering structure damages in addition to strong ground motion. Most of structures located on faulting zone has been destroyed by fault offset. Take the Norcia Earthquake in Italy (2016, Mw=6.2) as an example, the highway bridge in Arquata crossing the rupture area of the active normal fault suffered a quantity of displacement which causing abutment settlement, the piers of bridge fractured and so on. However, The Seismic Design Provisions and Commentary for Highway Bridges in Taiwan, the stating of it in the general rule of first chapter, the design in bridges crossing active fault: "This specification is not applicable of making design in bridges crossing or near active fault, that design ought to the other particular considerations ".This indicates that the safty of bridges crossing active fault are not only consider the seismic performance, the most ground deformation should be attended. In this research, to understand the failure mechanism and the deformation characteristics, we will organize the case which the bridges subjected faulting at home and abroad. The processes of research are through physical sandbox experiment and numerical simulation by discrete element models (PFC3-D). The normal fault case in Taiwan is Shanchiao Fault. As above, the research can explore the deformation in overburden soil and the influences in the foundations of bridges by normal faulting. While we can understand the behavior of foundations, we will make the bridge superstructures into two separations, simple beam and continuous beam and make a further research on the main control variables in bridges by faulting. Through the above mentioned, we can then give appropriate suggestions about planning considerations and design approaches. This research presents results from sandbox experiment and 3-D numerical analysis to simulate overburden soil and embedded pile foundations subjected to normal faulting. In order to validate this numerical model, it is compared to sandbox experiments. Since the 3-D numerical analysis corresponds to the sandbox expeiments, the response of pile foundations and ground deformation induced by normal faulting are discussed. To understand the 3-D behavior of ground deformation and pile foundations, the observation such as the triangular shear zone, the width of primary deformation zone and the inclination, displacements, of the pile foundations are discussed in experiments and simulations. Furthermore, to understand the safty of bridges crossing faulting zone. The different superstructures of bridges, simple beam and continuous beam will be discussed subsequently in simulations.

How Did the Spider Cross the River? Behavioral Adaptations for River-Bridging Webs in Caerostris darwini (Araneae: Araneidae)

PubMed Central

Gregorič, Matjaž; Agnarsson, Ingi; Blackledge, Todd A.; Kuntner, Matjaž

2011-01-01

Background Interspecific coevolution is well described, but we know significantly less about how multiple traits coevolve within a species, particularly between behavioral traits and biomechanical properties of animals' “extended phenotypes”. In orb weaving spiders, coevolution of spider behavior with ecological and physical traits of their webs is expected. Darwin's bark spider (Caerostris darwini) bridges large water bodies, building the largest known orb webs utilizing the toughest known silk. Here, we examine C. darwini web building behaviors to establish how bridge lines are formed over water. We also test the prediction that this spider's unique web ecology and architecture coevolved with new web building behaviors. Methodology We observed C. darwini in its natural habitat and filmed web building. We observed 90 web building events, and compared web building behaviors to other species of orb web spiders. Conclusions Caerostris darwini uses a unique set of behaviors, some unknown in other spiders, to construct its enormous webs. First, the spiders release unusually large amounts of bridging silk into the air, which is then carried downwind, across the water body, establishing bridge lines. Second, the spiders perform almost no web site exploration. Third, they construct the orb capture area below the initial bridge line. In contrast to all known orb-weavers, the web hub is therefore not part of the initial bridge line but is instead built de novo. Fourth, the orb contains two types of radial threads, with those in the upper half of the web doubled. These unique behaviors result in a giant, yet rather simplified web. Our results continue to build evidence for the coevolution of behavioral (web building), ecological (web microhabitat) and biomaterial (silk biomechanics) traits that combined allow C. darwini to occupy a unique niche among spiders. PMID:22046378

The Armstrong experiment revisited

NASA Astrophysics Data System (ADS)

Fuchs, Elmar C.; Wexler, Adam D.; Paulitsch-Fuchs, Astrid H.; Agostinho, Luewton L. F.; Yntema, Doekle; Woisetschläger, Jakob

2014-04-01

When a high-voltage direct-current is applied to two beakers filled with water or polar liquid dielectrica, a horizontal bridge forms between the two beakers. This experiment was first carried out by Lord Armstrong in 1893 and then forgotten until recently. Such bridges are stable by the action of electrohydrodynamic (EHD) forces caused by electric field gradients counteracting gravity. Due to these gradients a permanent pumping of liquid from one beaker into the other is observed. At macroscopic scale several of the properties of a horizontal water bridge can be explained by modern electrohydrodynamics, analyzing the motion of fluids in electric fields. Whereas on the molecular scale water can be described by quantum mechanics, there is a conceptual gap at mesoscopic scale which is bridged by a number of theories including quantum mechanical entanglement and coherent structures in water - theories that we discuss here. Much of the phenomenon is already understood, but even more can still be learned from it, since such "floating" liquid bridges resemble a small high voltage laboratory of their own: The physics of liquids in electric fields of some kV/cm can be studied, even long time experiments like neutron or light scattering are feasible since the bridge is in a steady-state equilibrium and can be kept stable for hours. It is also an electro-chemical reactor where compounds are transported through by the EHD flow, enabling the study of electrochemical reactions under potentials which are otherwise not easily accessible. Last but not least the bridge provides the experimental biologist with the opportunity to expose living organisms such as bacteria to electric fields without killing them, but with a significant influence on their behavior, and possibly, even on their genome.

Physical and structural properties of Sm3+ ions doped heavy metal oxide containing lanthanum-boro-telluirte glass

NASA Astrophysics Data System (ADS)

Madhu, A.; Eraiah, B.

2018-05-01

The structural studies of Tellurium oxide substituted by samarium oxide in lathanum-lead-boro-tellurite glass are successfully prepared with physical and optical parameters are determined. Due to the effect of increased number of non-bridging oxygen's in the glass samples few physical parameters are observed to be decreased. For the better structural analysis FTIR was carried out and transformation of BO3 → BO4 is observed. Most effective absorption coefficient OH- group was attained in the present work.

Basics of Bayesian methods.

PubMed

Ghosh, Sujit K

2010-01-01

Bayesian methods are rapidly becoming popular tools for making statistical inference in various fields of science including biology, engineering, finance, and genetics. One of the key aspects of Bayesian inferential method is its logical foundation that provides a coherent framework to utilize not only empirical but also scientific information available to a researcher. Prior knowledge arising from scientific background, expert judgment, or previously collected data is used to build a prior distribution which is then combined with current data via the likelihood function to characterize the current state of knowledge using the so-called posterior distribution. Bayesian methods allow the use of models of complex physical phenomena that were previously too difficult to estimate (e.g., using asymptotic approximations). Bayesian methods offer a means of more fully understanding issues that are central to many practical problems by allowing researchers to build integrated models based on hierarchical conditional distributions that can be estimated even with limited amounts of data. Furthermore, advances in numerical integration methods, particularly those based on Monte Carlo methods, have made it possible to compute the optimal Bayes estimators. However, there is a reasonably wide gap between the background of the empirically trained scientists and the full weight of Bayesian statistical inference. Hence, one of the goals of this chapter is to bridge the gap by offering elementary to advanced concepts that emphasize linkages between standard approaches and full probability modeling via Bayesian methods.

On Instructional Utility, Statistical Methodology, and the Added Value of ECD: Lessons Learned from the Special Issue

ERIC Educational Resources Information Center

Nelson, Brian; Nugent, Rebecca; Rupp, Andre A.

2012-01-01

This special issue of "JEDM" was dedicated to bridging work done in the disciplines of "educational and psychological assessment" and "educational data mining" (EDM) via the assessment design and implementation framework of "evidence-centered design" (ECD). It consisted of a series of five papers: one…

Bridging the gap between habitat-modeling research and bird conservation with dynamic landscape and population models

Treesearch

Frank R., III Thompson

2009-01-01

Habitat models are widely used in bird conservation planning to assess current habitat or populations and to evaluate management alternatives. These models include species-habitat matrix or database models, habitat suitability models, and statistical models that predict abundance. While extremely useful, these approaches have some limitations.

Bridging national and reference definitions for harmonizing forest statistics

Treesearch

Göran ​Ståhl; Emil Cienciala; Gherardo Chirici; Adrian Lanz; Claude Vidal; Susanne Winter; Ronald E. McRoberts; Jacques Rondeux; Klemens Schadauer; Erkki Tomppo

2012-01-01

Harmonization is the process of making information and estimates comparable across administrative borders. The degree to which harmonization succeeds depends on many factors, including the conciseness of the definitions, the availability and quality of data, and the methods used to convert an estimate according to a local definition to an estimate according to the...

Infographics And Public Policy: Using Data Visualization To Convey Complex Information.

PubMed

Otten, Jennifer J; Cheng, Karen; Drewnowski, Adam

2015-11-01

Data visualization combines principles from psychology, usability, graphic design, and statistics to highlight important data in accessible and appealing formats. Doing so helps bridge knowledge producers with knowledge users, who are often inundated with information and increasingly pressed for time. Project HOPE—The People-to-People Health Foundation, Inc.

Statistical analysis of early failures in electromigration

NASA Astrophysics Data System (ADS)

Gall, M.; Capasso, C.; Jawarani, D.; Hernandez, R.; Kawasaki, H.; Ho, P. S.

2001-07-01

The detection of early failures in electromigration (EM) and the complicated statistical nature of this important reliability phenomenon have been difficult issues to treat in the past. A satisfactory experimental approach for the detection and the statistical analysis of early failures has not yet been established. This is mainly due to the rare occurrence of early failures and difficulties in testing of large sample populations. Furthermore, experimental data on the EM behavior as a function of varying number of failure links are scarce. In this study, a technique utilizing large interconnect arrays in conjunction with the well-known Wheatstone Bridge is presented. Three types of structures with a varying number of Ti/TiN/Al(Cu)/TiN-based interconnects were used, starting from a small unit of five lines in parallel. A serial arrangement of this unit enabled testing of interconnect arrays encompassing 480 possible failure links. In addition, a Wheatstone Bridge-type wiring using four large arrays in each device enabled simultaneous testing of 1920 interconnects. In conjunction with a statistical deconvolution to the single interconnect level, the results indicate that the electromigration failure mechanism studied here follows perfect lognormal behavior down to the four sigma level. The statistical deconvolution procedure is described in detail. Over a temperature range from 155 to 200 °C, a total of more than 75 000 interconnects were tested. None of the samples have shown an indication of early, or alternate, failure mechanisms. The activation energy of the EM mechanism studied here, namely the Cu incubation time, was determined to be Q=1.08±0.05 eV. We surmise that interface diffusion of Cu along the Al(Cu) sidewalls and along the top and bottom refractory layers, coupled with grain boundary diffusion within the interconnects, constitutes the Cu incubation mechanism.

Channel evolution of the Hatchie River near the U.S. Highway 51 crossing in Lauderdale and Tipton counties, West Tennessee

USGS Publications Warehouse

Bryan, B.A.

1989-01-01

An investigation was conducted to describe the channel cross-section evolution near the bridge crossing of the Hatchie River at U.S. Highway 51 in Lauderdale and Tipton Counties, in West Tennessee. The study also included velocity and discharge distributions near the bridge crossing, and definition of streamflow duration and flood frequencies at the bridge site and comparison of these statistics with flows prior to the bridge collapse. Cross-section measurements at the site indicated that the channel was widening at a rate of 0.8 ft/year from 1931 through about 1975. The channel bed was stable at an elevation of about 235 ft. Construction of a south bound bridge in 1974 and 1975 reduced the effective flow width from about 4,000 to about 1,000 ft. Data collected from 1975 to 1981 indicated that the channel bed degraded to an elevation of about 230 ft and the widening rate increased to about 4.5 ft/year. The channel bed returned to approximately the pre-construction elevation of 235 ft as channel width increased. The widening rate decreased to about 1.8 ft/year from 1981 through 1989. Channel-geometry data indicated that recent channel morphology changes along the toe of the right bank have resulted in continued bank undercutting and bank failure. Cross-section geometry and flow-velocity distributions from measurements made from April 6 through 10, 1989, indicate that there is a high-flow meander pattern through this river reach and that the bridges are located at the point where the current strikes the right bank. (USGS)

Comparison of submuscular and open plating of pediatric femur fractures: a retrospective review.

PubMed

Abbott, Matthew D; Loder, Randall T; Anglen, Jeffrey O

2013-01-01

Plate osteosynthesis is an accepted method of treatment of pediatric femur fractures. Historically, open plating has been used. Submuscular bridge plating has gained recent popularity due to the theoretical advantages of decreased operative time, decreased blood loss, and decreased risk for infection. The purpose of this study was to compare submuscular bridge plating to open plating of pediatric femur fractures. We retrospectively reviewed 79 patients (80 treated femur fractures) between 1999 and 2011 that underwent either open plating (58 femur fractures) or submuscular bridge plating (22 femur fractures). The outcome measures evaluated were operative time, estimated blood loss, malunion, leg length discrepancy, time to union, infection, unplanned return to the operating room, and length of hospital stay after surgery. Among our outcome measures, there was no difference between the 2 groups in terms of operative time, leg length discrepancy, time to union, infection, or length of hospital stay after surgery. There was greater estimated blood loss in the open plating group (P≤0.0001) and greater rotational asymmetry in the submuscular bridge plating group (P=0.005). There was a trend of increased unplanned return to the operating room in the open plating group (5/58 vs. 0/22) although not statistically significant (P=0.32). Submuscular bridge plating and open plating seem to be equally viable options for the management of pediatric diaphyseal femur fractures. In this study, open plating had an increase in estimated blood loss and a trend of more unplanned returns to the operating room, whereas submuscular bridge plating had an increase in asymptomatic rotational asymmetry. Further larger, prospective, randomized studies are necessary to further evaluate these operative techniques. Therapeutic Level III.

Self-reported physical health of inmates: Impact of incarceration and relation to optimism

PubMed Central

Heigel, Caron P.; Stuewig, Jeffrey; Tangney, June P.

2011-01-01

This study investigated the relationship between inmates’ physical health concerns and optimism. Optimism has been consistently associated with physical health in community samples, but little research has examined this potentially malleable variable in an inmate population. This study of 502 male and female jail inmates attempts to bridge this gap. Results showed optimism was negatively associated with physical health concerns upon entry to jail and prior to release or transfer. Additionally, optimism assessed upon entry to jail predicted modest decreases in physical health concerns over incarceration. Results suggest that optimism is a health-related variable that may be beneficial when optimism-increasing components are integrated into treatment. PMID:20339128

Functional performance testing for power and return to sports.

PubMed

Manske, Robert; Reiman, Michael

2013-05-01

Functional performance testing of athletes can determine physical limitations that may affect sporting activities. Optimal functional performance testing simulates the athlete's activity. A Medline search from 1960 to 2012 was implemented with the keywords functional testing, functional impairment testing, and functional performance testing in the English language. Each author also undertook independent searches of article references. Functional performance tests can bridge the gap between general physical tests and full, unrestricted athletic activity.

Extending Counter-Streaming Motion from an Active Region Filament to Sunspot Light Bridge

NASA Astrophysics Data System (ADS)

Wang, Haimin; Liu, Rui; Deng, Na; Liu, Chang; Xu, Yan; Jing, Ju; Wang, Yuming; Cao, Wenda

2017-08-01

In this study, we analyze the high-resolution observations from the 1.6 m New Solar Telescope at Big Bear Solar Observatory that cover an entire active region filament. The southern end of the filament is well defined by a narrow lane situated in the negative magnetic polarity, while the northern end lies in the positive polarity, extending to a much larger area. Counter-streaming motions are clearly seen in the filament. The northern end of the counter-streaming motions extends to a light bridge, forming a spectacular circulation pattern around a sunspot, with clockwise motion in the blue wing and counterclockwise motion in the red wing as observed in H-alpha off-band. The apparent speed of the flow is around 10 km/s. We show that the southern end of the filament is consistent with that of a flux rope in a NLFFF extrapolation model, but the northern ends of the modeled flux rope and observed H-alpha footpoints have a significant spatial mismatch. The most intriguing results are the magnetic structure and the counter-streaming motions in the light bridge. Similar to those in the filament, magnetic fields show a dominant transverse component in the light bridge. However, the filament is located between opposite magnetic polarities, while the light bridge is between strong fields of the same polarity. We studied the correlation coefficients of image sequences of constructed Dopplergrams, and found that the filament and the section of light bridge next to it do not show oscillation motions, while a small section of light bridge shows a prominent oscillation pattern. Therefore, we conclude that the observed circulating counter-streaming motions are largely collections of physical mass flows in the transverse direction from the filament extending to a large section of the light bridge, rather than a form of periodic oscillatory mass motions in line-of-sight direction generated by perturbations omnipresent in the chromosphere.

The effects of elevated highway construction on water quality in Louisiana wetlands : final report.

DOT National Transportation Integrated Search

1981-02-02

This study is to determined by physical, chemical, and biological means, the effects of bridged highway construction techniques on water quality in wetlands. Water quality was monitored before, during, and after construction. The data shows the incre...

Effectiveness of violator penalties in compelling compliance with state truck weight limits

DOT National Transportation Integrated Search

1997-01-01

This is the 1997 edition of a series of reports required by Congress on America's surface transportation system. The report provides information on the physical and operating characteristics of the highway, bridge, and transit portions of our Nation'...

A bibliometric analysis of statistical terms used in American Physical Therapy Association journals (2011-2012): evidence for educating physical therapists.

PubMed

Tilson, Julie K; Marshall, Katie; Tam, Jodi J; Fetters, Linda

2016-04-22

A primary barrier to the implementation of evidence based practice (EBP) in physical therapy is therapists' limited ability to understand and interpret statistics. Physical therapists demonstrate limited skills and report low self-efficacy for interpreting results of statistical procedures. While standards for physical therapist education include statistics, little empirical evidence is available to inform what should constitute such curricula. The purpose of this study was to conduct a census of the statistical terms and study designs used in physical therapy literature and to use the results to make recommendations for curricular development in physical therapist education. We conducted a bibliometric analysis of 14 peer-reviewed journals associated with the American Physical Therapy Association over 12 months (Oct 2011-Sept 2012). Trained raters recorded every statistical term appearing in identified systematic reviews, primary research reports, and case series and case reports. Investigator-reported study design was also recorded. Terms representing the same statistical test or concept were combined into a single, representative term. Cumulative percentage was used to identify the most common representative statistical terms. Common representative terms were organized into eight categories to inform curricular design. Of 485 articles reviewed, 391 met the inclusion criteria. These 391 articles used 532 different terms which were combined into 321 representative terms; 13.1 (sd = 8.0) terms per article. Eighty-one representative terms constituted 90% of all representative term occurrences. Of the remaining 240 representative terms, 105 (44%) were used in only one article. The most common study design was prospective cohort (32.5%). Physical therapy literature contains a large number of statistical terms and concepts for readers to navigate. However, in the year sampled, 81 representative terms accounted for 90% of all occurrences. These "common representative terms" can be used to inform curricula to promote physical therapists' skills, competency, and confidence in interpreting statistics in their professional literature. We make specific recommendations for curriculum development informed by our findings.

Hybridization and cytonuclear associations among native westslope cutthroat trout, introduced rainbow trout, and their hybrids within the Stehekin River drainage, North Cascades National Park

USGS Publications Warehouse

Ostberg, C.O.; Rodriguez, R.J.

2006-01-01

Historic introductions of nonnative rainbow trout Oncorhynchus mykiss into the native habitats of cutthroat trout O. clarkii have impacted cutthroat trout populations through introgressive hybridization, creating challenges and concerns for cutthroat trout conservation. We examined the effects of rainbow trout introductions on the native westslope cutthroat trout O. c. lewisii within the Stehekin River drainage, North Cascades National Park, Washington, by analyzing 1,763 salmonid DNA samples from 18 locations with nine diagnostic nuclear DNA markers and one diagnostic mitochondrial DNA (mtDNA) marker. Pure westslope cutthroat trout populations only occurred above upstream migration barriers in the Stehekin River and Park Creek. Two categories of rainbow trout admixture were observed: (1) less than 10% within the Stehekin River drainage above the Bridge Creek confluence and the middle and upper Bridge Creek drainage and (2) greater than 30% within the Stehekin River below the Bridge Creek confluence and in lower Bridge Creek. Hybrid indices and multilocus genotypes revealed an absence of rainbow trout and reduced hybrid diversity within the Stehekin River above the Bridge Creek confluence relative to hybrid diversity in the Stehekin River below the confluence and within lower Bridge Creek. Cytonuclear disequilibrium statistics revealed assortative mating between westslope cutthroat and rainbow trout but not among hybrids within the same locations. This suggests that a randomly mating hybrid swarm does not currently exist. However, continual migration of parental genotypes into the study location could also create significant cytonuclear disequilibria. The Stehekin River represents a novel and unique example of a dynamic hybridization zone where the invasion of rainbow trout alleles into the Stehekin River westslope cutthroat trout population above the Bridge Creek confluence appears to be impeded, suggesting that divergent ecological or evolutionary mechanisms promote the population structure within the Stehekin River drainage, depending upon location.

Nonlinear dynamics as an engine of computation.

PubMed

Kia, Behnam; Lindner, John F; Ditto, William L

2017-03-06

Control of chaos teaches that control theory can tame the complex, random-like behaviour of chaotic systems. This alliance between control methods and physics-cybernetical physics-opens the door to many applications, including dynamics-based computing. In this article, we introduce nonlinear dynamics and its rich, sometimes chaotic behaviour as an engine of computation. We review our work that has demonstrated how to compute using nonlinear dynamics. Furthermore, we investigate the interrelationship between invariant measures of a dynamical system and its computing power to strengthen the bridge between physics and computation.This article is part of the themed issue 'Horizons of cybernetical physics'. © 2017 The Author(s).

Statistical Analysis of Stress Signals from Bridge Monitoring by FBG System.

PubMed

Ye, Xiao-Wei; Su, You-Hua; Xi, Pei-Sen

2018-02-07

In this paper, a fiber Bragg grating (FBG)-based stress monitoring system instrumented on an orthotropic steel deck arch bridge is demonstrated. The FBG sensors are installed at two types of critical fatigue-prone welded joints to measure the strain and temperature signals. A total of 64 FBG sensors are deployed around the rib-to-deck and rib-to-diagram areas at the mid-span and quarter-span of the investigated orthotropic steel bridge. The local stress behaviors caused by the highway loading and temperature effect during the construction and operation periods are presented with the aid of a wavelet multi-resolution analysis approach. In addition, the multi-modal characteristic of the rainflow counted stress spectrum is modeled by the method of finite mixture distribution together with a genetic algorithm (GA)-based parameter estimation approach. The optimal probability distribution of the stress spectrum is determined by use of Bayesian information criterion (BIC). Furthermore, the hot spot stress of the welded joint is calculated by an extrapolation method recommended in the specification of International Institute of Welding (IIW). The stochastic characteristic of stress concentration factor (SCF) of the concerned welded joint is addressed. The proposed FBG-based stress monitoring system and probabilistic stress evaluation methods can provide an effective tool for structural monitoring and condition assessment of orthotropic steel bridges.

Comparative Evaluation of Flexural Strength of Provisional Crown and Bridge Materials-An Invitro Study

PubMed Central

Garg, Sandeep

2016-01-01

Introduction Provisional restorations serve a key role as a functional and esthetic try-in for the design of the final prosthesis. During selection of materials for this restoration, clinicians must consider physical properties, ease of handling, cost and patient satisfaction and approval. Aim To evaluate and compare the flexural strength of provisional crown and bridge materials available commercially. Materials and Methods This in-vitro study was done to compare the flexural strength of six temporary crown and bridge materials available commercially at 24 hours, 8 days and after repair. Three poly methyl methacrylate based materials (DPI, SC10 and Trulon) and three bis-acrylic based composite resins (Protemp, Cooltemp and Luxatemp) were selected. A total of 72 specimens of dimensions 64mm×10mm×2.5mm were prepared from these materials (12 from each material) and divided into two groups (n=36). Specimens were stored in artificial saliva and were fractured after 24 hours and 8 days using Universal Testing Machine. The fractured samples from the 8 days study were then subjected to repair. A uniform space of 2mm and a 450 bevel was maintained for all the repaired samples for better distribution of forces. Flexural strength of these repaired samples was recorded using the same machine. Results were recorded and statistically analysed by one-way Anova and Post hoc tests. Result: Results revealed that there was decrease in flexural strength for all the materials tested from 24 hours to 8 days, though flexural strength between poly methyl methacrylate and bis-acrylic resins was similar at 24 hours and 8 days time interval. A substantial decrease was noticed in the strength of bis-acrylic composite resins after repair. Conclusion From the current study it can be suggested that though there is decrease in flexural strength for all the materials from 24 hours to 8 days, both can be used to fabricate the provisional restorations. However, in the event of a fracture of a bis-acrylic provisional restoration, it may be more advantageous to make a new provisional restoration than to repair the fractured one. PMID:27656568

A review on the suitability of rubberized concrete for concrete bridge decks

NASA Astrophysics Data System (ADS)

Syamir Senin, Mohamad; Shahidan, Shahiron; Radziah Abdullah, Siti; Anting Guntor, Nickholas; Syazani Leman, Alif

2017-11-01

Road authorities manage a large population of ageing bridges, a substantial number of which fail to meet the current requirements either due to deterioration and other structural deficiencies or as a result of the escalating demands imposed by increased traffic. This problem is related to the dynamic load from vehicles. This problem can be solved by producing a type of concrete that can reduce the amplitude of oscillation or vibration such as rubberized concrete. Green construction has been a very important aspect in concrete production field in the last decade. One of the most problematic waste materials is scrap tires. The use of scrap tires in civil engineering is increasing by producing rubberized concrete. Rubberized concrete is a type of concrete that is mixed with rubber. The purpose of this review is to justify the suitability of rubberized concrete for concrete bridge decks. Several parameters named physical, chemical and mechanical properties were measured to ensure the suitability of rubberized concrete for concrete bridge decks. Rubberized concrete has similar workability to normal concrete. The rubber reduced the density and compressive strength of the concrete while increased the flexural strength, water absorption and damping ratio. The used of rubber in concrete beyond 20% is not recommended due to decreasing in compressive strength. Rubberized concrete recommended to be used in circumstances where vibration damping was required such as in bridge construction as shock-wave absorber.

High speed transient sampler

DOEpatents

McEwan, T.E.

1995-11-28

A high speed sampler comprises a meandered sample transmission line for transmitting an input signal, a straight strobe transmission line for transmitting a strobe signal, and a plurality of sampling gates along the transmission lines. The sampling gates comprise a four terminal diode bridge having a first strobe resistor connected from a first terminal of the bridge to the positive strobe line, a second strobe resistor coupled from the third terminal of the bridge to the negative strobe line, a tap connected to the second terminal of the bridge and to the sample transmission line, and a sample holding capacitor connected to the fourth terminal of the bridge. The resistance of the first and second strobe resistors is much higher than the signal transmission line impedance in the preferred system. This results in a sampling gate which applies a very small load on the sample transmission line and on the strobe generator. The sample holding capacitor is implemented using a smaller capacitor and a larger capacitor isolated from the smaller capacitor by resistance. The high speed sampler of the present invention is also characterized by other optimizations, including transmission line tap compensation, stepped impedance strobe line, a multi-layer physical layout, and unique strobe generator design. A plurality of banks of such samplers are controlled for concatenated or interleaved sample intervals to achieve long sample lengths or short sample spacing. 17 figs.

High speed transient sampler

DOEpatents

McEwan, Thomas E.

1995-01-01

A high speed sampler comprises a meandered sample transmission line for transmitting an input signal, a straight strobe transmission line for transmitting a strobe signal, and a plurality of sampling gates along the transmission lines. The sampling gates comprise a four terminal diode bridge having a first strobe resistor connected from a first terminal of the bridge to the positive strobe line, a second strobe resistor coupled from the third terminal of the bridge to the negative strobe line, a tap connected to the second terminal of the bridge and to the sample transmission line, and a sample holding capacitor connected to the fourth terminal of the bridge. The resistance of the first and second strobe resistors is much higher than the signal transmission line impedance in the preferred system. This results in a sampling gate which applies a very small load on the sample transmission line and on the strobe generator. The sample holding capacitor is implemented using a smaller capacitor and a larger capacitor isolated from the smaller capacitor by resistance. The high speed sampler of the present invention is also characterized by other optimizations, including transmission line tap compensation, stepped impedance strobe line, a multi-layer physical layout, and unique strobe generator design. A plurality of banks of such samplers are controlled for concatenated or interleaved sample intervals to achieve long sample lengths or short sample spacing.

An unexpected semi-hydrogenation of a ligand in the complexation of 2,7-bispyridinyl-1,8-naphthyridine with Ru3(CO)12.

PubMed

Liao, Bei-Sih; Liu, Yi-Hung; Peng, Shie-Ming; Reddy, K Rajender; Liu, Shin-Hung; Chou, Pi-Tai; Liu, Shiuh-Tzung

2014-03-07

Thermal reaction of 2,7-bis(2-pyridinyl)-l,8-naphthyridine () with Ru3(CO)12 in the presence of moisture resulted in the formation of a formate-bridged diruthenium complex [(-H3)Ru2(μ-HCOO)(CO)4] (), in which the ligand was partially hydrogenated. Complex was fully characterized by spectroscopic analyses and X-ray single crystal determination. Regarding the partially reduced ligand in , it occurs through a water-gas shift type reduction. The bridging formate ligand can be substituted by other carboxylate ligands. Physical and chemical properties of the newly prepared complexes were investigated.

A Good Time to Dance? A Mixed-Methods Approach of the Effects of Dance Movement Therapy for Breast Cancer Patients During and After Radiotherapy.

PubMed

Ho, Rainbow T H; Lo, Phyllis H Y; Luk, Mai Yee

2016-01-01

Dance movement therapy (DMT) is premised on an interconnected body and mind. It has known benefits for cancer patients' physical and psychological health and quality of life. To offer greater insight into a previous randomized controlled trial, the present study qualitatively explored the beneficial elements of DMT over the course of radiotherapy. To better understand the uniqueness of DMT intervention for patients receiving radiotherapy, the study statistically compared them with patients who received DMT after treatment completion. Participants were randomized into radiotherapy and postradiotherapy control groups. The radiotherapy group received DMT (6 sessions at 90 minutes each) as they were undergoing radiotherapy. The postradiotherapy group was provided with the same DMT intervention at 1 to 2 months after completing radiotherapy. One hundred and four participants identified 5 main benefit categories. Dance movement therapy helped them (1) cope with cancer, treatment, and physical symptoms; (2) improve mental well-being, attention, and appreciation for the self and body; (3) improve total functioning; (4) bridge back to a normal and better life; and (5) participate in shared positive experiences. The radiotherapy group reported categories 1 and 2 more prominently than did the postradiotherapy group. The findings reinforced the benefits of DMT while adding the new perspective that delivering DMT intervention throughout cancer treatment can have different and even additional benefits for patients. The pleasure of dancing and the psychological and physical relief from DMT help patients cope with daily radiation treatments. This could decrease treatment dropout rates when administered in clinical settings.

Effects of functional resistance training on fitness and quality of life in females with chronic nonspecific low-back pain.

PubMed

Cortell-Tormo, Juan M; Sánchez, Pablo Tercedor; Chulvi-Medrano, Ivan; Tortosa-Martínez, Juan; Manchado-López, Carmen; Llana-Belloch, Salvador; Pérez-Soriano, Pedro

2018-02-06

Exercise is important as adjuvant in the chronic low back pain (CLBP) treatment. Functional training could involve benefits for low back pain (LBP) patients. To evaluate the effects of a 12-week period of functional resistance training on health-related quality of life (HRQOL), disability, body pain, and physical fitness in CLBP females. Nineteen females CLBP were recruited according to Paris Task Force on Back Pain criteria. Participants were randomly assigned to an exercise group (EG); and a control group (CG). Subjects were tested at baseline and at week 12 after 24 sessions, 2 days per week. Body pain was assessed using visual analog scale (VAS), disability with Oswestry Disability Index (ODI) and HRQOL with Short Form 36 questionnaire. Physical fitness was measured using: flamingo test, back endurance test, side bridge test, abdominal curl-up tests, and 60-s squat test. EG showed significant improvements in physical function (10%; p< 0.05), body pain (42%; p< 0.05), vitality (31%; p< 0.05), physical component scale (15%; p< 0.05), VAS (62.5%; p< 0.01), ODI (61.3%; p< 0.05), balance (58%; p< 0.05), curl-up (83%; p< 0.01), squat (22%; p< 0.01), static back (67%; p< 0.01), and side bridge (56%; p< 0.01). Periodized functional resistance training decreased pain and disability and improved HRQOL, balance and physical fitness in females with CLBP, and can thus be used safely in this population.

Comparison of Neural Network and Linear Regression Models in Statistically Predicting Mental and Physical Health Status of Breast Cancer Survivors

DTIC Science & Technology

2015-07-15

Long-term effects on cancer survivors’ quality of life of physical training versus physical training combined with cognitive-behavioral therapy ...COMPARISON OF NEURAL NETWORK AND LINEAR REGRESSION MODELS IN STATISTICALLY PREDICTING MENTAL AND PHYSICAL HEALTH STATUS OF BREAST...34Comparison of Neural Network and Linear Regression Models in Statistically Predicting Mental and Physical Health Status of Breast Cancer Survivors

A response surface methodology based damage identification technique

NASA Astrophysics Data System (ADS)

Fang, S. E.; Perera, R.

2009-06-01

Response surface methodology (RSM) is a combination of statistical and mathematical techniques to represent the relationship between the inputs and outputs of a physical system by explicit functions. This methodology has been widely employed in many applications such as design optimization, response prediction and model validation. But so far the literature related to its application in structural damage identification (SDI) is scarce. Therefore this study attempts to present a systematic SDI procedure comprising four sequential steps of feature selection, parameter screening, primary response surface (RS) modeling and updating, and reference-state RS modeling with SDI realization using the factorial design (FD) and the central composite design (CCD). The last two steps imply the implementation of inverse problems by model updating in which the RS models substitute the FE models. The proposed method was verified against a numerical beam, a tested reinforced concrete (RC) frame and an experimental full-scale bridge with the modal frequency being the output responses. It was found that the proposed RSM-based method performs well in predicting the damage of both numerical and experimental structures having single and multiple damage scenarios. The screening capacity of the FD can provide quantitative estimation of the significance levels of updating parameters. Meanwhile, the second-order polynomial model established by the CCD provides adequate accuracy in expressing the dynamic behavior of a physical system.

Clinical Rating of Movement-Pattern Quality in Patients With Femoroacetabular Impingement Syndrome: A Methodological Study.

PubMed

Casartelli, Nicola C; Maffiuletti, Nicola A; Brunner, Romana; Büchi, Marcel; Sutter, Reto; Pfirrmann, Christian W; Naal, Florian D; Leunig, Michael; Bizzini, Mario

2018-04-01

Study Design Cross-sectional study. Objectives To evaluate intrarater and interrater agreement among physical therapists with different clinical experience in performing a visual rating of movement-pattern quality of patients with femoroacetabular impingement (FAI) syndrome using a semi-quantitative scale. Background Visual rating of movement patterns in patients with FAI syndrome is of interest, because poor control of dynamic hip motion is frequently noted. Methods A video camera was used to record the performance of 34 patients with FAI syndrome performing single-limb standing, squat, frontal lunge, hop lunge, bridge, and plank. Visual rating of movement, as recorded on video, was performed by a highly experienced, a moderately experienced, and a novice physical therapist on 2 occasions using a semi-quantitative scale. Hip abductor strength was assessed using dynamometry, and hip pain and function were assessed with a patient-reported questionnaire. Intrarater and interrater agreement among physical therapists was evaluated using Gwet's agreement coefficient 1. Construct validity was evaluated as the association between physical therapists' rating and patients' hip abductor strength, pain, and function. Results Good intrarater and interrater agreement was observed in the highly experienced and moderately experienced physical therapists when rating single-limb standing, bridge, and plank. Poor to moderate intrarater and interrater agreement was found when they rated squat, frontal lunge, and hop lunge. Poor performers, as rated by the highly experienced physical therapist only, demonstrated lower hip abductor strength (P<.05), and similar hip pain and hip function compared to those of good performers. Conclusion Movement-pattern quality of patients with FAI syndrome should be rated by a highly experienced physical therapist. J Orthop Sports Phys Ther 2018;48(4):260-269. doi:10.2519/jospt.2018.7840.

25 CFR 170.923 - What qualifies for ERFO funding?

Code of Federal Regulations, 2010 CFR

2010-04-01

... Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER INDIAN RESERVATION ROADS... can use ERFO funding to repair damage to IRR transportation facilities (including roads, bridges, and...) Structural deficiencies, normal physical deterioration, and routine heavy maintenance do not qualify for ERFO...

The effects of elevated highway construction on water quality in Louisiana wetlands : interim report No. 1.

DOT National Transportation Integrated Search

1979-07-01

This study is to determined by physical, chemical, and biological means, the effects of bridged highway construction techniques on water quality in wetlands. Water quality was monitored before, during, and after construction. The data shows the incre...

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

Tanaka, T.J.; Nowlen, S.P.; Anderson, D.J.

Smoke can adversely affect digital electronics; in the short term, it can lead to circuit bridging and in the long term to corrosion of metal parts. This report is a summary of the work to date and component-level tests by Sandia National Laboratories for the Nuclear Regulatory Commission to determine the impact of smoke on digital instrumentation and control equipment. The component tests focused on short-term effects such as circuit bridging in typical components and the factors that can influence how much the smoke will affect them. These factors include the component technology and packaging, physical board protection, and environmentalmore » conditions such as the amount of smoke, temperature of burn, and humidity level. The likelihood of circuit bridging was tested by measuring leakage currents and converting those currents to resistance in ohms. Hermetically sealed ceramic packages were more resistant to smoke than plastic packages. Coating the boards with an acrylic spray provided some protection against circuit bridging. The smoke generation factors that affect the resistance the most are humidity, fuel level, and burn temperature. The use of CO{sub 2} as a fire suppressant, the presence of galvanic metal, and the presence of PVC did not significantly affect the outcome of these results.« less

The Cal-Bridge Program: Increasing the Gender and Ethnic Diversity of Astrophysics Students in Southern California

NASA Astrophysics Data System (ADS)

Smecker-Hane, Tammy A.; Rudolph, Alexander L.

2016-06-01

The mission of the Cal-Bridge program is to increase the number of underrepresented minority and women students completing a bachelor’s degree and entering a PhD program in astronomy, physics, or closely-related fields. The program has created a network of faculty at diverse higher education institutions, including 5 University of California (UC) campuses, 9 California State Universities (CSUs), and 10 community colleges in southern California, dedicated to this goal. Students selected for the program are know as “Cal-Bridge Scholars” and they are given a wide variety of support: (1) scholarships in their junior/senior years at CSU and their first year of graduate school at a UC, (2) intensive mentoring by a pair of CSU and UC faculty members, (3) tutoring, when needed, (4) professional development workshops, (5) exposure to research opportunities at various universities, and (6) membership in a growing cohort of like-minded students. We report on the structure of our program, lessons learned with our current 12 Cal-Bridge scholars, and the results of our first two years of operation. Funding for this program is provided by NSF-SSTEM Grant #1356133.

Electrostatic Assist of Liquid Transfer in Printing Processes

NASA Astrophysics Data System (ADS)

Huang, Chung-Hsuan; Kumar, Satish

2016-11-01

Transfer of liquid from one surface to another plays an important role in many printing processes. Incomplete liquid transfer can produce defects that are detrimental to the operation of printed electronic devices, and one strategy for minimizing these defects is to apply an electric field, a technique known as electrostatic assist (ESA). However, the underlying physical mechanisms of ESA remain a mystery. To better understand these mechanisms, slender-jet models for both perfect dielectric and leaky dielectric Newtonian liquid bridges with moving contact lines are developed. Nonlinear partial differential equations describing the time- and axial-evolution of the bridge radius and interfacial charge are derived, and then solved using finite-element methods. For perfect dielectrics, it is found that application of an electric field enhances transfer of liquid to the more wettable surface. For leaky dielectrics, application of an electric field can augment or oppose the influence of wettability differences, depending on the direction of the electric field and the sign of the interfacial charge. The physical mechanisms underlying these observations will be discussed.

The Effect of Remelting on the Physical Properties of Borotellurite Glass Doped with Manganese

PubMed Central

Hashim, Syed Putra Hashim Syed; Sidek, Haji Abdul Aziz; Halimah, Mohamed Kamari; Matori, Khamirul Amin; Yusof, Wan Mohamad Daud Wan; Zaid, Mohd Hafiz Mohd

2013-01-01

A systematic set of borotellurite glasses doped with manganese (1–x) [(B2O3)0.3(TeO2)0.7]-xMnO, with x = 0.1, 0.2, 0.3 and 0.4 mol%, were successfully synthesized by using a conventional melt and quench-casting technique. In this study, the remelting effect of the glass samples on their microstructure was investigated through density measurement and FT-IR spectra and evaluated by XRD techniques. Initial experimental results from XRD evaluation show that there are two distinct phases of glassy and crystallite microstructure due to the existence of peaks in the sample. The different physical behaviors of the studied glasses were closely related to the concentration of manganese in each phase. FTIR spectra revealed that the addition of manganese oxide contributes the transformation of TeO4 trigonal bipyramids with bridging oxygen (BO) to TeO3 trigonal pyramids with non-bridging oxygen (NBO). PMID:23296276

A spring-block analogy for the dynamics of stock indexes

NASA Astrophysics Data System (ADS)

Sándor, Bulcsú; Néda, Zoltán

2015-06-01

A spring-block chain placed on a running conveyor belt is considered for modeling stylized facts observed in the dynamics of stock indexes. Individual stocks are modeled by the blocks, while the stock-stock correlations are introduced via simple elastic forces acting in the springs. The dragging effect of the moving belt corresponds to the expected economic growth. The spring-block system produces collective behavior and avalanche like phenomena, similar to the ones observed in stock markets. An artificial index is defined for the spring-block chain, and its dynamics is compared with the one measured for the Dow Jones Industrial Average. For certain parameter regions the model reproduces qualitatively well the dynamics of the logarithmic index, the logarithmic returns, the distribution of the logarithmic returns, the avalanche-size distribution and the distribution of the investment horizons. A noticeable success of the model is that it is able to account for the gain-loss asymmetry observed in the inverse statistics. Our approach has mainly a pedagogical value, bridging between a complex socio-economic phenomena and a basic (mechanical) model in physics.

On the problem of boundaries and scaling for urban street networks

PubMed Central

Masucci, A. Paolo; Arcaute, Elsa; Hatna, Erez; Stanilov, Kiril; Batty, Michael

2015-01-01

Urban morphology has presented significant intellectual challenges to mathematicians and physicists ever since the eighteenth century, when Euler first explored the famous Königsberg bridges problem. Many important regularities and scaling laws have been observed in urban studies, including Zipf's law and Gibrat's law, rendering cities attractive systems for analysis within statistical physics. Nevertheless, a broad consensus on how cities and their boundaries are defined is still lacking. Applying an elementary clustering technique to the street intersection space, we show that growth curves for the maximum cluster size of the largest cities in the UK and in California collapse to a single curve, namely the logistic. Subsequently, by introducing the concept of the condensation threshold, we show that natural boundaries of cities can be well defined in a universal way. This allows us to study and discuss systematically some of the regularities that are present in cities. We show that some scaling laws present consistent behaviour in space and time, thus suggesting the presence of common principles at the basis of the evolution of urban systems. PMID:26468071

On the problem of boundaries and scaling for urban street networks.

PubMed

Masucci, A Paolo; Arcaute, Elsa; Hatna, Erez; Stanilov, Kiril; Batty, Michael

2015-10-06

Urban morphology has presented significant intellectual challenges to mathematicians and physicists ever since the eighteenth century, when Euler first explored the famous Königsberg bridges problem. Many important regularities and scaling laws have been observed in urban studies, including Zipf's law and Gibrat's law, rendering cities attractive systems for analysis within statistical physics. Nevertheless, a broad consensus on how cities and their boundaries are defined is still lacking. Applying an elementary clustering technique to the street intersection space, we show that growth curves for the maximum cluster size of the largest cities in the UK and in California collapse to a single curve, namely the logistic. Subsequently, by introducing the concept of the condensation threshold, we show that natural boundaries of cities can be well defined in a universal way. This allows us to study and discuss systematically some of the regularities that are present in cities. We show that some scaling laws present consistent behaviour in space and time, thus suggesting the presence of common principles at the basis of the evolution of urban systems. © 2015 The Authors.

Estimation of π-π Electronic Couplings from Current Measurements.

PubMed

Trasobares, J; Rech, J; Jonckheere, T; Martin, T; Aleveque, O; Levillain, E; Diez-Cabanes, V; Olivier, Y; Cornil, J; Nys, J P; Sivakumarasamy, R; Smaali, K; Leclere, P; Fujiwara, A; Théron, D; Vuillaume, D; Clément, N

2017-05-10

The π-π interactions between organic molecules are among the most important parameters for optimizing the transport and optical properties of organic transistors, light-emitting diodes, and (bio-) molecular devices. Despite substantial theoretical progress, direct experimental measurement of the π-π electronic coupling energy parameter t has remained an old challenge due to molecular structural variability and the large number of parameters that affect the charge transport. Here, we propose a study of π-π interactions from electrochemical and current measurements on a large array of ferrocene-thiolated gold nanocrystals. We confirm the theoretical prediction that t can be assessed from a statistical analysis of current histograms. The extracted value of t ≈35 meV is in the expected range based on our density functional theory analysis. Furthermore, the t distribution is not necessarily Gaussian and could be used as an ultrasensitive technique to assess intermolecular distance fluctuation at the subangström level. The present work establishes a direct bridge between quantum chemistry, electrochemistry, organic electronics, and mesoscopic physics, all of which were used to discuss results and perspectives in a quantitative manner.

Phase Transitions in Finite Systems

NASA Astrophysics Data System (ADS)

Chomaz, Philippe; Gulminelli, Francesca

In this series of lectures we will first review the general theory of phase transition in the framework of information theory and briefly address some of the well known mean field solutions of three dimensional problems. The theory of phase transitions in finite systems will then be discussed, with a special emphasis to the conceptual problems linked to a thermodynamical description for small, short-lived, open systems as metal clusters and data samples coming from nuclear collisions. The concept of negative heat capacity developed in the early seventies in the context of self-gravitating systems will be reinterpreted in the general framework of convexity anomalies of thermostatistical potentials. The connection with the distribution of the order parameter will lead us to a definition of first order phase transitions in finite systems based on topology anomalies of the event distribution in the space of observations. Finally a careful study of the thermodynamical limit will provide a bridge with the standard theory of phase transitions and show that in a wide class of physical situations the different statistical ensembles are irreducibly inequivalent.

The Bridges and Barriers Model of Support for High-Functioning Students with ASD in Mainstream Schools

ERIC Educational Resources Information Center

Holcombe, Wendy; Plunkett, Margaret

2016-01-01

National statistics indicate the ongoing challenge of catering for the unique needs of students with Autism Spectrum Disorder (ASD) within the context of inclusive education. Higher rates of difficulty and poorer outcomes are experienced by this cohort when compared to both the general population and others within the disability sector. The…

Bridging the Gap between Theory and Model: A Reflection on the Balance Scale Task.

ERIC Educational Resources Information Center

Turner, Geoffrey F. W.; Thomas, Hoben

2002-01-01

Focuses on individual strengths of articles by Jensen and van der Maas, and Halford et al., and the power of their combined perspectives. Suggests a performance model that can both evaluate specific theoretical claims and reveal important data features that had been previously obscured using conventional statistical analyses. Maintains that the…

From Theory to Air Force Practice: Applications and Non-Binary Extensions of Probabilistic Model-Building Genetic Algorithms

DTIC Science & Technology

2006-05-31

dynamics (MD) and kinetic Monte Carlo ( KMC ) procedures. In 2D surface modeling our calculations project speedups of 9 orders of magnitude at 300 degrees...programming is used to perform customized statistical mechanics by bridging the different time scales of MD and KMC quickly and well. Speedups in

Bridging the Gap: The Struggle of One Hispanic Father

ERIC Educational Resources Information Center

Vasquez, Sarah

2016-01-01

Parent involvement has been shown to be one of the keys to student educational success, their ability to perform at a high level and persevere. The latest government statistics reveal that 53 million Hispanics now reside in the United States and 75 % of this population speaks Spanish at home [Cooper, M. (2014). "Hispanics in America and in…

Bridging the Gap: Cognitive and Social Approaches to Research in Second Language Learning and Teaching

ERIC Educational Resources Information Center

Hulstijn, Jan H.; Young, Richard F.; Ortega, Lourdes; Bigelow, Martha; DeKeyser, Robert; Ellis, Nick C.; Lantolf, James P.; Mackey, Alison; Talmy, Steven

2014-01-01

For some, research in learning and teaching of a second language (L2) runs the risk of disintegrating into irreconcilable approaches to L2 learning and use. On the one side, we find researchers investigating linguistic-cognitive issues, often using quantitative research methods including inferential statistics; on the other side, we find…

What can we learn from noise? — Mesoscopic nonequilibrium statistical physics —

PubMed Central

KOBAYASHI, Kensuke

2016-01-01

Mesoscopic systems — small electric circuits working in quantum regime — offer us a unique experimental stage to explorer quantum transport in a tunable and precise way. The purpose of this Review is to show how they can contribute to statistical physics. We introduce the significance of fluctuation, or equivalently noise, as noise measurement enables us to address the fundamental aspects of a physical system. The significance of the fluctuation theorem (FT) in statistical physics is noted. We explain what information can be deduced from the current noise measurement in mesoscopic systems. As an important application of the noise measurement to statistical physics, we describe our experimental work on the current and current noise in an electron interferometer, which is the first experimental test of FT in quantum regime. Our attempt will shed new light in the research field of mesoscopic quantum statistical physics. PMID:27477456

What can we learn from noise? - Mesoscopic nonequilibrium statistical physics.

PubMed

Kobayashi, Kensuke

2016-01-01

Mesoscopic systems - small electric circuits working in quantum regime - offer us a unique experimental stage to explorer quantum transport in a tunable and precise way. The purpose of this Review is to show how they can contribute to statistical physics. We introduce the significance of fluctuation, or equivalently noise, as noise measurement enables us to address the fundamental aspects of a physical system. The significance of the fluctuation theorem (FT) in statistical physics is noted. We explain what information can be deduced from the current noise measurement in mesoscopic systems. As an important application of the noise measurement to statistical physics, we describe our experimental work on the current and current noise in an electron interferometer, which is the first experimental test of FT in quantum regime. Our attempt will shed new light in the research field of mesoscopic quantum statistical physics.

Increasing Diversity at the PhD Level in Astronomy: The Fisk-Vanderbilt Masters-to-PhD Bridge Program

NASA Astrophysics Data System (ADS)

Stassun, Keivan; Holley-Bockelmann, K.; Berlind, A. A.

2013-01-01

We briefly review the current status of underrepresented minorities in the physical sciences: The underrepresentation of Black-, Hispanic-, and Native-Americans is an order of magnitude problem. We then describe the Fisk-Vanderbilt Masters-to-PhD Bridge program as a successful model for effective partnerships with minority-serving institutions toward addressing this problem. Since 2004 the program has admitted 60 students, 54 of them underrepresented minorities (60% female), with a retention rate of 92%. The program leads the nation in master’s degrees in physics for African Americans, is one of the top ten producers of physics master’s degrees among all US citizens in general, and has become the nation’s top producer of underrepresented minority PhDs in physics, astronomy, and materials science. We summarize the main features of the program including two of its core strategies: (1) partnering a minority-serving institution and a major research university through collaborative research, and (2) using the master’s degree as a deliberate stepping stone to the PhD. We also specifically discuss one of the emerging core theories of the program: the concept of properly identifying students with 'unrealized or unrecognized potential'. We discuss our methods to recognize and select for unrealized potential during the admissions process, and how we cultivate that unrealized potential toward development of successful scientists and leaders.

Driving Forces in Physical, Biological and Socio-economic Phenomena

NASA Astrophysics Data System (ADS)

Roehner, Bertrand M.

2007-05-01

Preface; Part I. Bridging the Gap between Physics and the Social Sciences: 1. Probing bonds; 2. The battle against noise in physics; 3. The battle against noise in the social sciences; 4. Equilibrium and metastable states; 5. Are the data reliable?; Part II. Macro Interactions: Societies and States: 6. Shaping the zeitgeist; 7. Bonds of vassalage; 8. The absentee ownership syndrome; Part III. Micro Interactions: A Network View of Suicide: 9. Effects of male-female imbalance; 10. Effect of weakened marital bonds on suicide; 11. Effect of social isolation on suicide; 12. Apoptosis; 13. Perspectives; References; Index.

Driving Forces in Physical, Biological and Socio-economic Phenomena

NASA Astrophysics Data System (ADS)

Roehner, Bertrand M.

2012-10-01

Preface; Part I. Bridging the Gap between Physics and the Social Sciences: 1. Probing bonds; 2. The battle against noise in physics; 3. The battle against noise in the social sciences; 4. Equilibrium and metastable states; 5. Are the data reliable?; Part II. Macro Interactions: Societies and States: 6. Shaping the zeitgeist; 7. Bonds of vassalage; 8. The absentee ownership syndrome; Part III. Micro Interactions: A Network View of Suicide: 9. Effects of male-female imbalance; 10. Effect of weakened marital bonds on suicide; 11. Effect of social isolation on suicide; 12. Apoptosis; 13. Perspectives; References; Index.

Physical fitness modulates incidental but not intentional statistical learning of simultaneous auditory sequences during concurrent physical exercise.

PubMed

Daikoku, Tatsuya; Takahashi, Yuji; Futagami, Hiroko; Tarumoto, Nagayoshi; Yasuda, Hideki

2017-02-01

In real-world auditory environments, humans are exposed to overlapping auditory information such as those made by human voices and musical instruments even during routine physical activities such as walking and cycling. The present study investigated how concurrent physical exercise affects performance of incidental and intentional learning of overlapping auditory streams, and whether physical fitness modulates the performances of learning. Participants were grouped with 11 participants with lower and higher fitness each, based on their Vo 2 max value. They were presented simultaneous auditory sequences with a distinct statistical regularity each other (i.e. statistical learning), while they were pedaling on the bike and seating on a bike at rest. In experiment 1, they were instructed to attend to one of the two sequences and ignore to the other sequence. In experiment 2, they were instructed to attend to both of the two sequences. After exposure to the sequences, learning effects were evaluated by familiarity test. In the experiment 1, performance of statistical learning of ignored sequences during concurrent pedaling could be higher in the participants with high than low physical fitness, whereas in attended sequence, there was no significant difference in performance of statistical learning between high than low physical fitness. Furthermore, there was no significant effect of physical fitness on learning while resting. In the experiment 2, the both participants with high and low physical fitness could perform intentional statistical learning of two simultaneous sequences in the both exercise and rest sessions. The improvement in physical fitness might facilitate incidental but not intentional statistical learning of simultaneous auditory sequences during concurrent physical exercise.

Hypothesis Testing as an Act of Rationality

NASA Astrophysics Data System (ADS)

Nearing, Grey

2017-04-01

Statistical hypothesis testing is ad hoc in two ways. First, setting probabilistic rejection criteria is, as Neyman (1957) put it, an act of will rather than an act of rationality. Second, physical theories like conservation laws do not inherently admit probabilistic predictions, and so we must use what are called epistemic bridge principles to connect model predictions with the actual methods of hypothesis testing. In practice, these bridge principles are likelihood functions, error functions, or performance metrics. I propose that the reason we are faced with these problems is because we have historically failed to account for a fundamental component of basic logic - namely the portion of logic that explains how epistemic states evolve in the presence of empirical data. This component of Cox' (1946) calculitic logic is called information theory (Knuth, 2005), and adding information theory our hypothetico-deductive account of science yields straightforward solutions to both of the above problems. This also yields a straightforward method for dealing with Popper's (1963) problem of verisimilitude by facilitating a quantitative approach to measuring process isomorphism. In practice, this involves data assimilation. Finally, information theory allows us to reliably bound measures of epistemic uncertainty, thereby avoiding the problem of Bayesian incoherency under misspecified priors (Grünwald, 2006). I therefore propose solutions to four of the fundamental problems inherent in both hypothetico-deductive and/or Bayesian hypothesis testing. - Neyman (1957) Inductive Behavior as a Basic Concept of Philosophy of Science. - Cox (1946) Probability, Frequency and Reasonable Expectation. - Knuth (2005) Lattice Duality: The Origin of Probability and Entropy. - Grünwald (2006). Bayesian Inconsistency under Misspecification. - Popper (1963) Conjectures and Refutations: The Growth of Scientific Knowledge.

Obstructive Left Colon Cancer Should Be Managed by Using a Subtotal Colectomy Instead of Colonic Stenting

PubMed Central

Min, Chung Ki; Lee, Donghyoun; Jung, Kyung Uk; Lee, Sung Ryol; Kim, Hungdai; Chun, Ho-Kyung

2016-01-01

Purpose This study compared a subtotal colectomy to self-expandable metallic stent (SEMS) insertion as a bridge to surgery for patients with left colon-cancer obstruction. Methods Ninety-four consecutive patients with left colon-cancer obstruction underwent an emergency subtotal colectomy or elective SEMS insertion between January 2007 and August 2014. Using prospectively collected data, we performed a retrospective comparative analysis on an intention-to-treat basis. Results A subtotal colectomy and SEMS insertion were attempted in 24 and 70 patients, respectively. SEMS insertion technically failed in 5 patients (7.1%). The mean age and rate of obstruction in the descending colon were higher in the subtotal colectomy group than the SEMS group. Sex, underlying disease, American Society of Anesthesiologists physical status, and pathological stage showed no statistical difference. Laparoscopic surgery was performed more frequently in patients in the SEMS group (62 of 70, 88.6%) than in patients in the subtotal colectomy group (4 of 24, 16.7%). The overall rate of postoperative morbidity was higher in the SEMS group. No Clavien-Dindo grade III or IV complications occurred in the subtotal colectomy group, but 2 patients (2.9%) died from septic complications in the SEMS group. One patient (4.2%) in the subtotal colectomy group had synchronous cancer. The total hospital stay was shorter in the subtotal colectomy group. The median number of bowel movements in the subtotal colectomy group was twice per day at postoperative 3–6 months. Conclusion A subtotal colectomy for patients with obstructive left-colon cancer is a clinically and oncologically safer, 1-stage, surgical strategy compared to SEMS insertion as a bridge to surgery. PMID:28119864

A Progression of Static Equilibrium Laboratory Exercises

ERIC Educational Resources Information Center

Kutzner, Mickey; Kutzner, Andrew

2013-01-01

Although simple architectural structures like bridges, catwalks, cantilevers, and Stonehenge have been integral in human societies for millennia, as have levers and other simple tools, modern students of introductory physics continue to grapple with Newton's conditions for static equilibrium. As formulated in typical introductory physics…

Bridging Student Health Risks and Academic Achievement through Comprehensive School Health Programs.

ERIC Educational Resources Information Center

Symons, Cynthia Wolford; Cinelli, Bethann; James, Tammy C.; Groff, Patti

1997-01-01

Research confirms a direct link between student health risk behavior and education outcomes, education behaviors, and student attitudes. This article discusses barriers to comprehensive school health programming; summarizes relevant information concerning several health-risk behaviors (intentional injuries, diet, physical activity, sexual-risk…

INDONESIA.

ERIC Educational Resources Information Center

MCVEY, RUTH T.

THIS UNIVERSITY-LEVEL TEXT IS AN ATTEMPT TO BRIDGE THE GAP BETWEEN SUPERFICIAL IMPRESSION AND SPECIALIZED KNOWLEDGE CONCERNING INDONESIA. IT PROVIDES AN INTRODUCTION TO INDONESIA THROUGH CHAPTERS ON--(1) PHYSICAL AND HUMAN RESOURCE PATTERNS, BY K.J. PELZER, (2) INDONESIAN CULTURES AND COMMUNITIES, BY H. GEERTZ, (3) THE CHINESE MINORITY, BY G.W.…

Aligning the Stars

ERIC Educational Resources Information Center

Oguntoyinbo, Lekan

2010-01-01

This article discusses how the Bridge program, a partnership between Fisk University and Vanderbilt University, can become the nation's leading producer of doctoral graduates in astronomy, physics and material sciences. A graduate at Fisk, Ebonee Walker gets free tuition to attend one of the world's leading universities, a book allowance, a…

The Practicality of Statistical Physics Handout Based on KKNI and the Constructivist Approach

NASA Astrophysics Data System (ADS)

Sari, S. Y.; Afrizon, R.

2018-04-01

Statistical physics lecture shows that: 1) the performance of lecturers, social climate, students’ competence and soft skills needed at work are in enough category, 2) students feel difficulties in following the lectures of statistical physics because it is abstract, 3) 40.72% of students needs more understanding in the form of repetition, practice questions and structured tasks, and 4) the depth of statistical physics material needs to be improved gradually and structured. This indicates that learning materials in accordance of The Indonesian National Qualification Framework or Kerangka Kualifikasi Nasional Indonesia (KKNI) with the appropriate learning approach are needed to help lecturers and students in lectures. The author has designed statistical physics handouts which have very valid criteria (90.89%) according to expert judgment. In addition, the practical level of handouts designed also needs to be considered in order to be easy to use, interesting and efficient in lectures. The purpose of this research is to know the practical level of statistical physics handout based on KKNI and a constructivist approach. This research is a part of research and development with 4-D model developed by Thiagarajan. This research activity has reached part of development test at Development stage. Data collection took place by using a questionnaire distributed to lecturers and students. Data analysis using descriptive data analysis techniques in the form of percentage. The analysis of the questionnaire shows that the handout of statistical physics has very practical criteria. The conclusion of this study is statistical physics handouts based on the KKNI and constructivist approach have been practically used in lectures.

Streambed stability and scour potential at selected bridge sites in Michigan

USGS Publications Warehouse

Holtschlag, D.J.; Miller, R.L.

1998-01-01

Contraction scour in the main stream channel at a bridge and local scour near piers and abutments can result in bridge failure. Estimates of contraction-scour and local-scour potentials associated with the 100-year flood were computed for 13 bridge sites in Michigan by use of semi-theoretical equations and procedures recommended by the Federal Highway Administration. These potentials were compared with measures of Streambed stability obtained by use of data from 773 historical streamflow measurements, documenting 20,741 individual Streambed soundings between 1959 and 1995. Analysis of these data indicate small, but statistically significant, monotonic trends in Streambed elevation at 10 sites. No consistent patterns in relations between changes in Streambed elevations and streamflow, flow velocity, or flow depth were evident. Also, estimates of contraction-scour potential were not correlated with measures of Streambed stability, and no differences were detected between measures of Streambed stability in the main channel and stability adjacent to piers. Despite the inconsistencies between measures of Streambed stability and scour potential, data from a single, large flood (greater than a 100-year event) provided field evidence that the relation between scour and streamflow is highly nonlinear. This nonlinearity and the limited availability of measurements of extreme flood events may have reduced the utility of the empirical measures for confirming the nonlinear scour-potential equations and procedures. Results of field surveys using ground-penetrating radar and tuned transducers showed limited ability to aid interpretation of historical scour conditions at four bridge sites. Additional research is needed to confirm the applicability of scour-potential equations for hydrogeologic conditions in Michigan.

A statistical mechanical approach to restricted integer partition functions

NASA Astrophysics Data System (ADS)

Zhou, Chi-Chun; Dai, Wu-Sheng

2018-05-01

The main aim of this paper is twofold: (1) suggesting a statistical mechanical approach to the calculation of the generating function of restricted integer partition functions which count the number of partitions—a way of writing an integer as a sum of other integers under certain restrictions. In this approach, the generating function of restricted integer partition functions is constructed from the canonical partition functions of various quantum gases. (2) Introducing a new type of restricted integer partition functions corresponding to general statistics which is a generalization of Gentile statistics in statistical mechanics; many kinds of restricted integer partition functions are special cases of this restricted integer partition function. Moreover, with statistical mechanics as a bridge, we reveal a mathematical fact: the generating function of restricted integer partition function is just the symmetric function which is a class of functions being invariant under the action of permutation groups. Using this approach, we provide some expressions of restricted integer partition functions as examples.

Sella turcica bridging and dental anomalies: is there an association?

PubMed

Scribante, Andrea; Sfondrini, Maria Francesca; Cassani, Marco; Fraticelli, Danilo; Beccari, Sergio; Gandini, Paola

2017-11-01

Sella turcica bridging (STB), or calcification of the interclinoid ligament of sella turcica, has been reported to be associated with some dental anomalies (palatal canine impaction and transposition). The aim of the study was to find any association between canine impaction, hyperdontia or hypodontia and sellar dimensions or bridging. Lateral cephalometric radiographs from 78 patients with impacted canines, 68 with dental agenesis and 17 with hyperdontia were collected. Linear dimensions of sella turcica were calculated and compared to those of a control group (47 individuals). A standardize scoring scale was used to quantify the extent of STB from each radiographs. The frequency of partial and complete calcifications of sella in patients with dental anomalies is increased when compared to controls. STB can influence the interclinoid distance but does not affect other linear dimensions of sella. No statistically significant difference has been found in sellar dimensions and STB expression when evaluating radiographs at different ages. STB is frequently found in patients with dental abnormalities. © 2017 BSPD, IAPD and John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Real-time and wearable functional electrical stimulation system for volitional hand motor function control using the electromyography bridge method

PubMed Central

Wang, Hai-peng; Bi, Zheng-yang; Zhou, Yang; Zhou, Yu-xuan; Wang, Zhi-gong; Lv, Xiao-ying

2017-01-01

Voluntary participation of hemiplegic patients is crucial for functional electrical stimulation therapy. A wearable functional electrical stimulation system has been proposed for real-time volitional hand motor function control using the electromyography bridge method. Through a series of novel design concepts, including the integration of a detecting circuit and an analog-to-digital converter, a miniaturized functional electrical stimulation circuit technique, a low-power super-regeneration chip for wireless receiving, and two wearable armbands, a prototype system has been established with reduced size, power, and overall cost. Based on wrist joint torque reproduction and classification experiments performed on six healthy subjects, the optimized surface electromyography thresholds and trained logistic regression classifier parameters were statistically chosen to establish wrist and hand motion control with high accuracy. Test results showed that wrist flexion/extension, hand grasp, and finger extension could be reproduced with high accuracy and low latency. This system can build a bridge of information transmission between healthy limbs and paralyzed limbs, effectively improve voluntary participation of hemiplegic patients, and elevate efficiency of rehabilitation training. PMID:28250759

PEOPLE IN PHYSICS: Nobel prize winners in physics from 1901 to 1990: simple statistics for physics teachers

NASA Astrophysics Data System (ADS)

Zhang, Weijia; Fuller, Robert G.

1998-05-01

A demographic database for the 139 Nobel prize winners in physics from 1901 to 1990 has been created from a variety of sources. The results of our statistical study are discussed in the light of the implications for physics teaching.

Universality of bridge functions and its relation to variational perturbation theory and additivity of equations of state

NASA Astrophysics Data System (ADS)

Rosenfeld, Yaakov

1984-05-01

Featuring the modified hypernetted-chain (MHNC) scheme as a variational fitting procedure, we demonstrate that the accuracy of the variational perturbation theory (VPT) and of the method based on additivity of equations of state is determined by the excess entropy dependence of the bridge-function parameters [i.e., η(s) when the Percus-Yevick hard-sphere bridge functions are employed]. It is found that η(s) is nearly universal for all soft (i.e., "physical") potentials while it is distinctly different for the hard spheres, providing a graphical display of the "jump" in pair-potential space (with respect to accuracy of VPT) from "hard" to "soft" behavior. The universality of η(s) provides a local criterion for the MHNC scheme that should be useful for inverting structure-factor data in order to obtain the potential. An alternative local MHNC criterion due to Lado is rederived and extended, and it is also analyzed in light of the plot of η(s).

Three Dimensional Analysis of the Final Design of Pier Extensions and West Guide Wall to Mitigate Local Scour Risk at the BNSF Railroad Bridge Downstream of the Prado Dam Supplemental Report

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

Lottes, S. A.; Sinha, N.; Bojanowski, C.

This report is a supplement to a previous report [ref] covering optimization of wedge shaped pier extensions to streamline large bluff body piers as a local scour countermeasure for the Burlington Northern and Santa Fe (BNSF) Railroad Bridge over the Santa Ana River downstream of Prado Dam in Riverside County, CA. The optimized design was tested in a 1/30 scale physical model at U.S. Army Engineer Research and Development Center (ERDC) in Vicksburg, MS, and the optimized design was used as the base for the construction design. Constructability issues having to do with both materials and site conditions including accessmore » underneath the BNSF bridge yielded a construction design that required making the pier extensions wider and either moving the western curve of the west guide wall upstream or changing its geometry.« less

Exciton interference revealed by energy dependent exciton transfer rate for ring-structured molecular systems

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

Yan, Yun-An, E-mail: yunan@gznc.edu.cn

2016-01-14

The quantum interference is an intrinsic phenomenon in quantum physics for photon and massive quantum particles. In principle, the quantum interference may also occur with quasi-particles, such as the exciton. In this study, we show how the exciton quantum interference can be significant in aggregates through theoretical simulations with hierarchical equations of motion. The systems under investigation are generalized donor-bridge-acceptor model aggregates with the donor consisting of six homogeneous sites assuming the nearest neighbor coupling. For the models with single-path bridge, the exciton transfer time only shows a weak excitation energy dependence. But models with double-path bridge have a newmore » short transfer time scale and the excitation energy dependence of the exciton transfer time assumes clear peak structure which is detectable with today’s nonlinear spectroscopy. This abnormality is attributed to the exciton quantum interference and the condition for a clear observation in experiment is also explored.« less

The world problem: on the computability of the topology of 4-manifolds

NASA Technical Reports Server (NTRS)

vanMeter, J. R.

2005-01-01

Topological classification of the 4-manifolds bridges computation theory and physics. A proof of the undecidability of the homeomorphy problem for 4-manifolds is outlined here in a clarifying way. It is shown that an arbitrary Turing machine with an arbitrary input can be encoded into the topology of a 4-manifold, such that the 4-manifold is homeomorphic to a certain other 4-manifold if and only if the corresponding Turing machine halts on the associated input. Physical implications are briefly discussed.

Microstructurally Based Cross-slip Mechanisms and Their Effects on Dislocation Microstructure Evolution in fcc Crystals

DTIC Science & Technology

2015-01-01

still necessary. One such model that could bridge this gap is discrete dis- location dynamics ( DDD ) simulations, in which both the time- and length-scale...limitations from atomic simulations are greatly reduced. Over the past two decades, two-dimen- sional (2D) and three-dimensional (3D) DDD methods have...dislocation ensem- bles according to physics-based rules [27–34]. The physics that can be incorporated in DDD simulations can range http://dx.doi.org

Functional Performance Testing for Power and Return to Sports

PubMed Central

Manske, Robert; Reiman, Michael

2013-01-01

Context: Functional performance testing of athletes can determine physical limitations that may affect sporting activities. Optimal functional performance testing simulates the athlete’s activity. Evidence Acquisition: A Medline search from 1960 to 2012 was implemented with the keywords functional testing, functional impairment testing, and functional performance testing in the English language. Each author also undertook independent searches of article references. Conclusion: Functional performance tests can bridge the gap between general physical tests and full, unrestricted athletic activity. PMID:24427396

H-Bridge Inverter Loading Analysis for an Energy Management System

DTIC Science & Technology

2013-06-01

In order to accomplish the stated objectives, a physics-based model of the system was developed in MATLAB/Simulink. The system was also implemented ...functional architecture and then compile the high level design down to VHDL in order to program the designed functions to the FPGA. B. INSULATED

Five Potential Crises.

ERIC Educational Resources Information Center

Futurist, 1984

1984-01-01

Five areas that have great potential for becoming crises in the future are described: a warming of the earth's climate, changing weather patterns and growing seasons; water shortage; the decay of the physical infrastructure, e.g., decay of roads, bridges; breakdown of the international monetary and trading system; and nuclear warfare. (Author/RM)

Bridges to Learning: A Guide to Parent Involvement.

ERIC Educational Resources Information Center

Friesen, Sharon

This resource guide aims to assist parents, other adults, and the school in providing a stronger continuum of educational opportunities for children at home and in the school. The introductory section provides background information on parent involvement. Section 2 discusses the physical, emotional/social, intellectual, and creative development of…

Bridging a Cultural Divide with Literature about Arabs and Arab Americans

ERIC Educational Resources Information Center

Al-Hazza, Tami Craft; Bucher, Katherine T.

2010-01-01

Middle school is a time of many changes for young adolescents. They are "searching for individual identity, struggling with society's norms, and grappling with moral issues." They are changing and maturing physically, cognitively, socially, and psychologically as they develop their identities; establish, maintain, and end friendships and social…

"Nobody's Perfect"--Partial Disagreement with Herman, Faust, Bridges, and Ahern

ERIC Educational Resources Information Center

Myers, John E. B.

2012-01-01

Determining whether a child was sexually abused is a tremendous clinical and legal challenge. In litigation, abuse is established--proven--with evidence. Evidence includes testimony from witnesses, hearsay statements, documents, and physical evidence such as semen, genital injury, and fingerprints. There are two types of witnesses: lay witnesses…

Alkaloids from Isopyrum thalictroides L.

PubMed

Istatkova, Ralitsa; Philipov, Stefan

2004-06-01

Two new aporphine-benzylisoquinoline alkaloids thaliphine and isothaliphine with a new type of ether bridge were isolated from the roots and rhyzomes of Isopyrum thalictroides L. (Ranunculaceae). Their structures were established by physical and spectral analysis. The known alkaloid N-methylglaucine was isolated for the first time from a plant of the family Ranunculaceae.

Building Bridges: Transitions from Elementary to Secondary School

ERIC Educational Resources Information Center

Tilleczek, Kate

2008-01-01

Most young people leave elementary school and move into some form of secondary school during early adolescence. At precisely the time that young people are navigating multiple developmental challenges (social, intellectual, academic, physical), they are expected to move between these intuitions of public education. The transition is commonly…

Coordinating Effective Field Experiences: Recommendations for Cooperating Teachers

ERIC Educational Resources Information Center

McEntyre, Kelsey; Baxter, Deborah; Richards, K. Andrew R.

2018-01-01

The role of the cooperating teacher is an integral component of field-based teacher education because the cooperating teacher can bridge the gap between the knowledge developed on campus during physical education teacher education and preservice teachers' field-based learning experiences leading up to and including student teaching. In order to…

Bridging Physics and Biology Using Resistance and Axons

NASA Astrophysics Data System (ADS)

Dyer, Joshua M.

2014-11-01

When teaching physics, it is often difficult to get biology-oriented students to see the relevance of physics.1 A complaint often heard is that biology students are required to take physics for the Medical College Admission Test (MCAT) as part of a "weeding out" process, but that they don't feel like they need physics for biology. Despite this impression held by students, there have been calls for better physics education for future physicians and life scientists.2,3 Research is being performed to improve physics classes and labs by linking topics in biology and physics.4,5 Described here is a laboratory experiment covering the topics of resistance of materials and circuits/Kirchhoff's laws in a biology context with their direct application to neurons, axons, and electrical impulse transmission within animals. This experiment will also demonstrate the mechanism believed to cause multiple sclerosis. The apparatus was designed with low-cost and readily available materials in mind.

The Building Bridges Project: Involving Older Adults in the Design of a Communication Technology to Support Peer-to-Peer Social Engagement

NASA Astrophysics Data System (ADS)

Wherton, Joseph; Prendergast, David

There are a variety of factors that can lead to social isolation and loneliness in old age, including decline in physical and mental health, as well as change to social environment. The Building Bridges project explores how communication technology can help older adults remain socially connected. This paper will first provide an overview of a prototype communication system designed to support peer-to-peer group interaction. A description of the user-centered design process will be provided to demonstrate the importance of involving older adults at the earliest stages. The implications for designing new technology for older adults are discussed.

Ubiquitous health in practice: the interreality paradigm.

PubMed

Gaggioli, Andrea; Raspelli, Simona; Grassi, Alessandra; Pallavicini, Federica; Cipresso, Pietro; Wiederhold, Brenda K; Riva, Giuseppe

2011-01-01

In this paper we introduce a new ubiquitous computing paradigm for behavioral health care: "Interreality". Interreality integrates assessment and treatment within a hybrid environment, that creates a bridge between the physical and virtual worlds. Our claim is that bridging virtual experiences (fully controlled by the therapist, used to learn coping skills and emotional regulation) with real experiences (allowing both the identification of any critical stressors and the assessment of what has been learned) using advanced technologies (virtual worlds, advanced sensors and PDA/mobile phones) may improve existing psychological treatment. To illustrate the proposed concept, a clinical scenario is also presented and discussed: Daniela, a 40 years old teacher, with a mother affected by Alzheimer's disease.

Modelling of hydrothermal instabilities in a capillary bridge

NASA Astrophysics Data System (ADS)

Pillai, Dipin; Wray, Alex; Narayanan, Ranga

2017-11-01

We examine the behaviour of a capillary bridge/boat suspended between two heated plates. Such systems are common in many physical situations such as crystal growth processes. However, as shown experimentally by Messmer et al., the system exhibits a complex array of behaviours driven by a Marangoni instability. While qualitative arguments have been advanced for these behaviours in the past, we develop a complete low-order model to elucidate the mechanisms at work. The model takes into account viscosity, surface tension, Marangoni stress and inertia as well as a full convection-diffusion equation for the thermal effects. Detailed comparisons of flow fields and thermal distributions are made with experiments. NASA NNX17AL27G and NSF 0968313.

Bridging simulations and experiment in shock and ramp induced phenomena

NASA Astrophysics Data System (ADS)

Flicker, Dawn

2014-03-01

The high pressure materials physics program at Sandia's Z facility includes strong collaboration between theory, simulations and experiments. This multi-disciplinary approach has led to new insights in many cases. Several examples will be discussed to illustrate the benefits of bridging simulations and experiments. Results will be chosen from recent work on the xenon equation of state, phase change in MgO, shock induced chemistry in CO2 and tantalum strength. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Work or retirement: Exploration of the experiences of Iranian retired nurses.

PubMed

Nobahar, Monir; Ahmadi, Fazlollah; Alhani, Fatemah; Khoshknab, Masood Fallahi

2015-01-01

According to recent studies, the level of international interest in bridge employment, as return to work after retirement, has been growing. This study aimed to explore the experiences of retired nurses in Iran with regard to making a decision about whether or not to seek bridge employment. A qualitative study using a content analysis approach was conducted in an urban area of Iran. Semi-structured interviews were held with 20 Iranian male and female retired nurses chosen using purposive sampling. During the data analysis, two main themes were identified as the participants' thoughts supporting the decision of seeking bridge employment. The first theme was entitled motivational factors with categories of ``serving the society,'' ``maintaining and promoting health,'' ``tendency toward flexible work,'' and ``maintaining the role and activity.'' The second theme was entitled forcing factors with categories of ``ardent desire to work (pluralistic ignorance)'' and ``financial need.' ' While some Iranian retired nurses were not motivated to seek work for health reasons, most preferred to return to work after retirement. They were motivated to seek bridge employment out of a desire to serve the society, to promote their own physical and mental health, to continue to use their expertise and maintain the worker role, and because of financial needs and perceived societal expectations. Nurses seeking employment later in life tended to look for job flexibility and less stressful work. Therefore, the management of bridge employment by healthcare system authorities can be useful in making use of the invaluable experiences of retired nurses.

Marx and Dahrendorf on Income Inequality, Class Consciousness and Class Conflict: An Empirical Test.

ERIC Educational Resources Information Center

Robinson, Robert V.; Kelley, Jonathan

The issue addressed by this paper is the lack of empirical research on the class theories of Karl Marx and Ralf Dahrendorf. In order to bridge this gap, data are analyzed on the theoretical and statistical implications of Marx's theory (which focuses on ownership of the means of production) and Dahrendorf's theory (which focuses on authority in…

The Truth, the Whole Truth, and Nothing but the Ground-Truth: Methods to Advance Environmental Justice and Researcher-Community Partnerships

ERIC Educational Resources Information Center

Sadd, James; Morello-Frosch, Rachel; Pastor, Manuel; Matsuoka, Martha; Prichard, Michele; Carter, Vanessa

2014-01-01

Environmental justice advocates often argue that environmental hazards and their health effects vary by neighborhood, income, and race. To assess these patterns and advance preventive policy, their colleagues in the research world often use complex and methodologically sophisticated statistical and geospatial techniques. One way to bridge the gap…

Statistical Analysis of Stress Signals from Bridge Monitoring by FBG System

PubMed Central

Ye, Xiao-Wei; Xi, Pei-Sen

2018-01-01

In this paper, a fiber Bragg grating (FBG)-based stress monitoring system instrumented on an orthotropic steel deck arch bridge is demonstrated. The FBG sensors are installed at two types of critical fatigue-prone welded joints to measure the strain and temperature signals. A total of 64 FBG sensors are deployed around the rib-to-deck and rib-to-diagram areas at the mid-span and quarter-span of the investigated orthotropic steel bridge. The local stress behaviors caused by the highway loading and temperature effect during the construction and operation periods are presented with the aid of a wavelet multi-resolution analysis approach. In addition, the multi-modal characteristic of the rainflow counted stress spectrum is modeled by the method of finite mixture distribution together with a genetic algorithm (GA)-based parameter estimation approach. The optimal probability distribution of the stress spectrum is determined by use of Bayesian information criterion (BIC). Furthermore, the hot spot stress of the welded joint is calculated by an extrapolation method recommended in the specification of International Institute of Welding (IIW). The stochastic characteristic of stress concentration factor (SCF) of the concerned welded joint is addressed. The proposed FBG-based stress monitoring system and probabilistic stress evaluation methods can provide an effective tool for structural monitoring and condition assessment of orthotropic steel bridges. PMID:29414850

Optical and Physical Investigations of Lanthanum Bismuth Borate glasses doped with Ho2O3

NASA Astrophysics Data System (ADS)

Ramesh, P.; Jagannath, G.; Eraiah, B.; Kokila, M. K.

2018-02-01

Holmium doped 10La2O3-15Bi2O3-(75-x) B2O3 (Ho3+: LBB) glasses have been prepared by melt quench technique and the impact of holmium ions concentration on optical and physical properties of present glasses have been examined. Ho3+ dependent density, molar volume, refractive index, rare earth ion concentration, polaron radius, inter ionic distance, field strength and energy band gap are calculated and tabulated. Amorphous nature of the all glasses has been confirmed by XRD patterns. The room temperature (RT) Uv-Vis absorption spectrum doped with 1 mol% of Ho2O3 exhibit eight prominent bands centred at 895, 641, 537, 486, 472, 467, 451 and 416 due to transition between ground state to various excited states. The results show that, the density is increases and molar volume of the glasses is decreases with an increase in Ho2O3 concentration and consequently generate more non-bridging oxygen (NBOs) in the glass matrix. The Urbach energy is increases with holmium concentration which exemplifies the degree of disorder present in the LBB glasses. The considerable increase in field strength observed in present glasses is attributed to occurrence of strong bridge between Ho3+ and B- ions and this strong bridge is possibly due to the displacement between Ho3+ and oxygen atoms which are generated from the conversion BO3-BO4 units.

Is math anxiety in the secondary classroom limiting physics mastery? A study of math anxiety and physics performance

NASA Astrophysics Data System (ADS)

Mercer, Gary J.

This quantitative study examined the relationship between secondary students with math anxiety and physics performance in an inquiry-based constructivist classroom. The Revised Math Anxiety Rating Scale was used to evaluate math anxiety levels. The results were then compared to the performance on a physics standardized final examination. A simple correlation was performed, followed by a multivariate regression analysis to examine effects based on gender and prior math background. The correlation showed statistical significance between math anxiety and physics performance. The regression analysis showed statistical significance for math anxiety, physics performance, and prior math background, but did not show statistical significance for math anxiety, physics performance, and gender.

Reconstructing Macroeconomics Based on Statistical Physics

NASA Astrophysics Data System (ADS)

Aoki, Masanao; Yoshikawa, Hiroshi

We believe that time has come to integrate the new approach based on statistical physics or econophysics into macroeconomics. Toward this goal, there must be more dialogues between physicists and economists. In this paper, we argue that there is no reason why the methods of statistical physics so successful in many fields of natural sciences cannot be usefully applied to macroeconomics that is meant to analyze the macroeconomy comprising a large number of economic agents. It is, in fact, weird to regard the macroeconomy as a homothetic enlargement of the representative micro agent. We trust the bright future of the new approach to macroeconomies based on statistical physics.

Identifying Node Role in Social Network Based on Multiple Indicators

PubMed Central

Huang, Shaobin; Lv, Tianyang; Zhang, Xizhe; Yang, Yange; Zheng, Weimin; Wen, Chao

2014-01-01

It is a classic topic of social network analysis to evaluate the importance of nodes and identify the node that takes on the role of core or bridge in a network. Because a single indicator is not sufficient to analyze multiple characteristics of a node, it is a natural solution to apply multiple indicators that should be selected carefully. An intuitive idea is to select some indicators with weak correlations to efficiently assess different characteristics of a node. However, this paper shows that it is much better to select the indicators with strong correlations. Because indicator correlation is based on the statistical analysis of a large number of nodes, the particularity of an important node will be outlined if its indicator relationship doesn't comply with the statistical correlation. Therefore, the paper selects the multiple indicators including degree, ego-betweenness centrality and eigenvector centrality to evaluate the importance and the role of a node. The importance of a node is equal to the normalized sum of its three indicators. A candidate for core or bridge is selected from the great degree nodes or the nodes with great ego-betweenness centrality respectively. Then, the role of a candidate is determined according to the difference between its indicators' relationship with the statistical correlation of the overall network. Based on 18 real networks and 3 kinds of model networks, the experimental results show that the proposed methods perform quite well in evaluating the importance of nodes and in identifying the node role. PMID:25089823

Statistics-related and reliability-physics-related failure processes in electronics devices and products

NASA Astrophysics Data System (ADS)

Suhir, E.

2014-05-01

The well known and widely used experimental reliability "passport" of a mass manufactured electronic or a photonic product — the bathtub curve — reflects the combined contribution of the statistics-related and reliability-physics (physics-of-failure)-related processes. When time progresses, the first process results in a decreasing failure rate, while the second process associated with the material aging and degradation leads to an increased failure rate. An attempt has been made in this analysis to assess the level of the reliability physics-related aging process from the available bathtub curve (diagram). It is assumed that the products of interest underwent the burn-in testing and therefore the obtained bathtub curve does not contain the infant mortality portion. It has been also assumed that the two random processes in question are statistically independent, and that the failure rate of the physical process can be obtained by deducting the theoretically assessed statistical failure rate from the bathtub curve ordinates. In the carried out numerical example, the Raleigh distribution for the statistical failure rate was used, for the sake of a relatively simple illustration. The developed methodology can be used in reliability physics evaluations, when there is a need to better understand the roles of the statistics-related and reliability-physics-related irreversible random processes in reliability evaluations. The future work should include investigations on how powerful and flexible methods and approaches of the statistical mechanics can be effectively employed, in addition to reliability physics techniques, to model the operational reliability of electronic and photonic products.

Multiscale modeling and simulation for nano/micro materials

NASA Astrophysics Data System (ADS)

Wang, Xianqiao

Continuum description and atomic description used to be two distinct methods in the community of modeling and simulations. Science and technology have become so advanced that our understanding of many physical phenomena involves the concepts of both. So our goal now is to build a bridge to make atoms and continua communicate with each other. Micromorphic theory (MMT) envisions a material body as a continuous collection of deformable particles; each possesses finite size and inner structure. It is considered as the most successful top-down formulation of a two-level continuum model to bridge the gap between the micro level and macro level. Therefore MMT can be expected to unveil many new classes of physical phenomena that fall beyond classical field theories. In this work, the constitutive equations for generalized Micromorphic thermoviscoelastic solid and generalized Micromorphic fluid have been formulated. To enlarge the domain of applicability of MMT, from nano, micro to macro, we take a bottom-up approach to re-derive the generalized atomistic field theory (AFT) comprehensively and completely and establish the relationship between AFT and MMT. Finite element (FE) method is then implemented to pursue the numerical solutions of the governing equations derived in AFT. When the finest mesh is used, i.e., the size of FE mesh is equal to the lattice constant of the material, the computational model becomes identical to molecular dynamics simulation. When a coarse mesh is used, the resulting model is a coarse-grained model, the majority of the degrees of freedom are eliminated and the computational cost is largely reduced. When the coarse mesh and finest mesh exist concurrently, i.e., the finest mesh is used in the critical regions and the coarser mesh is used in the far field, it leads naturally to a concurrent atomistic/continuum model. Atomic scale, coarse-grained scale and concurrent atomistic/continuum simulations have demonstrated the potential capability of AFT to simulate most grand challenging problems in nano/micro physics, and shown that AFT has the advantages of both atomic model and MMT. Therefore, AFT has accomplished the mission to bridge the gap between continuum mechanics and atomic physics.

Student Understanding of Taylor Series Expansions in Statistical Mechanics

ERIC Educational Resources Information Center

Smith, Trevor I.; Thompson, John R.; Mountcastle, Donald B.

2013-01-01

One goal of physics instruction is to have students learn to make physical meaning of specific mathematical expressions, concepts, and procedures in different physical settings. As part of research investigating student learning in statistical physics, we are developing curriculum materials that guide students through a derivation of the Boltzmann…

Biomechanical Assessment of the Dorsal Spanning Bridge Plate in Distal Radius Fracture Fixation: Implications for Immediate Weight-Bearing.

PubMed

Huang, Jerry I; Peterson, Bret; Bellevue, Kate; Lee, Nicolas; Smith, Sean; Herfat, Safa

2017-04-01

The goal of this study was to compare the biomechanical stability of a 2.4-mm dorsal spanning bridge plate with a volar locking plate (VLP) in a distal radius fracture model, during simulated crutch weight-bearing. Five paired cadaveric forearms were tested. A 1-cm dorsal wedge osteotomy was created to simulate an unstable distal radius fracture with dorsal comminution. Fractures were fixed with a VLP or a dorsal bridge plate (DBP). Specimens were mounted to a crutch handle, and optical motion-tracking sensors were attached to the proximal and distal segments. Specimens were loaded in compression at 1 mm/s on a servohydraulic test frame until failure, defined as 2 mm of gap site displacement. The VLP construct was significantly more stable to axial load in a crutch weight-bearing model compared with the DBP plate (VLP: 493 N vs DBP: 332 N). Stiffness was higher in the VLP constructs, but this was not statistically significant (VLP: 51.4 N/mm vs DBP: 32.4 N/mm). With the crutch weight-bearing model, DBP failed consistently with wrist flexion and plate bending, whereas VLP failed with axial compression at the fracture site and dorsal collapse. Dorsal spanning bridge plating is effective as an internal spanning fixator in treating highly comminuted intra-articular distal radius fracture and prevents axial collapse at the radiocarpal joint. However, bridge plating may not offer advantages in early weight-bearing or transfer in polytrauma patients, with less axial stability in our crutch weight-bearing model compared with volar plating. A stiffer 3.5-mm DBP or use of a DBP construct without the central holes may be considered for distal radius fractures if the goal is early crutch weight-bearing through the injured extremity.

50 CFR 300.22 - Eastern Pacific fisheries recordkeeping and written reports.

Code of Federal Regulations, 2011 CFR

2011-10-01

... fishing vessel or commercial passenger fishing vessel (CPFV) authorized to fish for tuna and tuna-like... relation to known physical features), and the tonnage of fish on board, by species. The record and bridge... resolutions of the IATTC, all commercial fishing vessels and CPFVs authorized to fish for tuna and tuna-like...

Letters to the Editor

NASA Astrophysics Data System (ADS)

1997-07-01

All the Letters to the Editor in this issue are in the same PostScript or PDF file. Contents Joining capacitors R Bridges King Edward's School, Birmingham B15 2UA, UK Enjoying Physics John Bausor 5 Longcrofte Road, Edgware, Middlesex HA8 6RR, UK The disadvantages of success M L Cooper Newham College of Further Education, London

Limitations and Functions: Four Examples of Integrating Thermodynamics

ERIC Educational Resources Information Center

Chang, Wheijen

2011-01-01

Physics students are usually unaware of the limitations and functions of related principles, and they tend to adopt "hot formulas" inappropriately. This paper introduces four real-life examples for bridging five principles, from fluids to thermodynamics, including (1) buoyant force, (2) thermal expansion, (3) the ideal-gas law, (4) the 1st law,…

Open Schooling for Secondary & Higher Secondary Education. Costs and Effectiveness in India and Namibia

ERIC Educational Resources Information Center

Rumble, Greville; Koul, Badri N

2007-01-01

As defined by the Commonwealth of Learning (COL), Open Schooling involves "the physical separation of the school-level learner from the teacher, and the use of unconventional teaching methodologies, and information and communications technologies (ICTs) to bridge the separation and provide the education and training". Within this…

Necessity Fuels Creativity: Adapting Long-Distance Collaborative Methods for the Classroom

ERIC Educational Resources Information Center

Sopoci Drake, Katie; Larson, Eliza; Rugh, Rachel; Tait, Barbara

2016-01-01

Improved technology has made it possible to virtually bridge distance between dance makers, rendering physical location another choreographic device to be manipulated. Long-distance collaboration as an artistic process is not only a fertile new ground for creation and necessary for many practicing dance artists in the field today, but there is…

Historical and Architectural Documentation of the Interurban Trolley Bridge at Three Mile Creek, Fort Riley, Kansas

DTIC Science & Technology

2009-09-01

legislation was the Antiquities Act of 1906. It was instrumental in securing protection for archeological resources on federal property. The benefits...5 2.1 Physical history ...derived from the Antiquities Act and subsequent legislation precipitated an expanded and broader need for the preservation of historic cultural

Inertial Navigation: A Bridge between Kinematics and Calculus

ERIC Educational Resources Information Center

Sadler, Philip M.; Garfield, Eliza N.; Tremblay, Alex; Sadler, Daniel J.

2012-01-01

Those who come to Cambridge soon learn that the fastest route between Harvard and MIT is by the subway. For many students, this short ride is a quick and easy way to link physics and calculus. A simple, homemade accelerometer provides all the instrumentation necessary to produce accurate graphs of acceleration, velocity, and displacement position…

Bridging classical and molecular genetics of cotton fiber quality and development

USDA-ARS?s Scientific Manuscript database

Cotton is the single most important natural fiber in the world and represents a vital agricultural commodity in the global economy. Ninety percent of cotton’s value resides in the lint fiber. Cotton fiber quality, defined by the physical properties of the lint fibers, is an important part of the cot...

Fibres, Blood and Broken Glass

ERIC Educational Resources Information Center

Tomlinson, Bob; Peacock, Alan

2005-01-01

Crime Scene Investigators (CSIs) are the bridge between the police and forensic science specialists. Their job is to recover physical evidence from the scene of a crime, and try to make sense of it to interpret and explain what probably happened--which is just what scientists also do. They recover many things: objects, photographs of the crime…

Bridging the Gap between the Data Base and User in a Distributed Environment.

ERIC Educational Resources Information Center

Howard, Richard D.; And Others

1989-01-01

The distribution of databases physically separates users from those who administer the database and the administrators who perform database administration. By drawing on the work of social scientists in reliability and validity, a set of concepts and a list of questions to ensure data quality were developed. (Author/MLW)

Focus on Physics: The Delightful Catenary Curve

ERIC Educational Resources Information Center

Hewitt, Paul G.

2017-01-01

When teaching how "tension" and "compression" relate to geometrical structures such as bridges, arches, and domes, The author shows a picture of the Notre Dame Cathedral in Paris, completed in the 14th century, and presents a lesson on using the curve called a catenary to explain how he teaches about tension and compression…

The Origins of Force--Misconceptions and Classroom Controversy.

ERIC Educational Resources Information Center

Steinberg, Melvin S.

Misconceptions associated with the origins of force and the effectiveness of a bridging strategy for developing correct conceptual models in mechanics are identified for high school physics teachers in this paper. The situation investigated was whether a table exerts an upward force on a book. Student misconceptions related to this phenomenon as…

Empirical likelihood-based tests for stochastic ordering

PubMed Central

BARMI, HAMMOU EL; MCKEAGUE, IAN W.

2013-01-01

This paper develops an empirical likelihood approach to testing for the presence of stochastic ordering among univariate distributions based on independent random samples from each distribution. The proposed test statistic is formed by integrating a localized empirical likelihood statistic with respect to the empirical distribution of the pooled sample. The asymptotic null distribution of this test statistic is found to have a simple distribution-free representation in terms of standard Brownian bridge processes. The approach is used to compare the lengths of rule of Roman Emperors over various historical periods, including the “decline and fall” phase of the empire. In a simulation study, the power of the proposed test is found to improve substantially upon that of a competing test due to El Barmi and Mukerjee. PMID:23874142

Directed Design of Experiments (DOE) for Determining Probability of Detection (POD) Capability of NDE Systems (DOEPOD)

NASA Technical Reports Server (NTRS)

Generazio, Edward R.

2007-01-01

This viewgraph presentation reviews some of the problems that are encountered by designers of Non-Destructive Examination (NDE) have in determining the probability of detection. According to the author "[the] NDE community should not blindly accept statistical results due to lack of knowledge." This is an attempt to bridge the gap between people doing NDE, and statisticians.

Entangling mobility and interactions in social media.

PubMed

Grabowicz, Przemyslaw A; Ramasco, José J; Gonçalves, Bruno; Eguíluz, Víctor M

2014-01-01

Daily interactions naturally define social circles. Individuals tend to be friends with the people they spend time with and they choose to spend time with their friends, inextricably entangling physical location and social relationships. As a result, it is possible to predict not only someone's location from their friends' locations but also friendship from spatial and temporal co-occurrence. While several models have been developed to separately describe mobility and the evolution of social networks, there is a lack of studies coupling social interactions and mobility. In this work, we introduce a model that bridges this gap by explicitly considering the feedback of mobility on the formation of social ties. Data coming from three online social networks (Twitter, Gowalla and Brightkite) is used for validation. Our model reproduces various topological and physical properties of the networks not captured by models uncoupling mobility and social interactions such as: i) the total size of the connected components, ii) the distance distribution between connected users, iii) the dependence of the reciprocity on the distance, iv) the variation of the social overlap and the clustering with the distance. Besides numerical simulations, a mean-field approach is also used to study analytically the main statistical features of the networks generated by a simplified version of our model. The robustness of the results to changes in the model parameters is explored, finding that a balance between friend visits and long-range random connections is essential to reproduce the geographical features of the empirical networks.

Small-scale chromospheric jets above a sunspot light bridge

NASA Astrophysics Data System (ADS)

Louis, Rohan E.; Beck, Christian; Ichimoto, Kiyoshi

2014-07-01

Context. The chromosphere above sunspot umbrae and penumbrae shows several different types of fast dynamic events such as running penumbral waves, umbral flashes, and penumbral microjets. Aims: The aim of this paper is to identify the physical driver responsible for the dynamic and small-scale chromospheric jets above a sunspot light bridge. Methods: High-resolution broadband filtergrams of active region NOAA 11271 in Ca ii H and G band were obtained with the Solar Optical Telescope on board Hinode. We identified the jets in the Ca ii H images using a semi-automatic routine and determined their length and orientation. We applied local correlation tracking (LCT) to the G-band images to obtain the photospheric horizontal velocity field. The magnetic field topology was derived from a Milne-Eddington inversion of a simultaneous scan with the Spectropolarimeter. Results: The chromospheric jets consist of a bright, triangular-shaped blob that lies on the light bridge, while the apex of this blob extends into a spike-like structure that is bright against the dark umbral background. Most of the jets have apparent lengths of less than 1000 km and about 30% of the jets have lengths between 1000-1600 km. The jets are oriented within ±35° to the normal of the spine of the light bridge. Most of them are clustered near the central part of the light bridge within a 2'' area. The jets are seen to move rapidly along the light bridge and many of them cannot be identified in successive images taken with a 2 min cadence. The jets are primarily located on one side of the light bridge and are directed into the umbral core. The Stokes profiles at or close to the location of the blobs on the LB exhibit both a significant net circular polarization and multiple components, including opposite-polarity lobes. The magnetic field diverges from the light bridge towards the umbral cores that it separates. The LCT reveals that in the photosphere there is a predominantly uni-directional flow with speeds of 100-150 m s-1 along the light bridge. This unidirectional flow is interrupted by a patch of weak or very small motions on the light bridge which also moves along the light bridge. Conclusions: The dynamic short-lived chromospheric jets above the LB seem to be guided by the magnetic field lines. Reconnection events are a likely trigger for such phenomenon since they occur at locations where the magnetic field changes orientation sharply and where we also observe isolated patches of opposite-polarity magnetic components. We find no clear relation between the jets and the photospheric flow pattern.

The contribution of statistical physics to evolutionary biology.

PubMed

de Vladar, Harold P; Barton, Nicholas H

2011-08-01

Evolutionary biology shares many concepts with statistical physics: both deal with populations, whether of molecules or organisms, and both seek to simplify evolution in very many dimensions. Often, methodologies have undergone parallel and independent development, as with stochastic methods in population genetics. Here, we discuss aspects of population genetics that have embraced methods from physics: non-equilibrium statistical mechanics, travelling waves and Monte-Carlo methods, among others, have been used to study polygenic evolution, rates of adaptation and range expansions. These applications indicate that evolutionary biology can further benefit from interactions with other areas of statistical physics; for example, by following the distribution of paths taken by a population through time. Copyright © 2011 Elsevier Ltd. All rights reserved.

Increasing Diversity in STEM through Ka Hikina O Ka Lā Summer Bridge Program for Native Hawaiian Students

NASA Astrophysics Data System (ADS)

Coopersmith, A.; Cie, D. K.; Calder, S.; Naho`olewa, D.; Rai, B.

2014-12-01

The Advanced Technology Solar Telescope (ATST) Mitigation Initiative and the Kahikina O Ka Lā Program are NSF-funded projects at the University of Hawai`i Maui College. These projects offer instruction and activities intended to increase diversity in STEM careers. Ke Alahaka, the 2014 summer bridge program, was offered to Native Hawaiian high-school students who indicated an interest in STEM areas. Content workshops were offered in Marine Science, Physics, Biotechnology, and Computer Science and Engineering as well as a Hawaiian Studies course designed to provide a cultural context for the STEM instruction. Focus groups and other program assessments indicate that 50% of the students attending the workshops intend to pursue a STEM major during their undergraduate studies.

Suction and cohesion demise in desaturating granular medium

NASA Astrophysics Data System (ADS)

Hueckel, T.; Mielniczuk, B.; El-Youssoufi, S. M.

2017-12-01

Continuum mechanics for unsaturated soils is based on the assumption of a one-to-one relationship betwee saturation degree and suction represented by the characteristic curve. Such curve commonly shows exceedingly high values of suction at saturation decreasing below 10%. We have performed a series of experiments on physical micro-structural models of 8-, 5, 4, 3, and 2-grain assemblies filled with water forming capillary, funicular and pendular bridges. Dynamic variables characterizing the evolution include: Laplace pressure, surface tension force, total intergralular force, contact angle and contact perimeter length. The Laplace pressure was calculated from the directly measured curvatures of interface surface for 2-grain bridges, and estimated from tomography stills for 3 grain bridges. The initial negative Laplace pressure (suction) as well as total intergranular force increase modestly at the begining of evaporation, but undergo an unstable decrease at the advanced stage, often with a jump in the force known as a Haines jumps since 1925. Laplace pressure turns into positive values prior to rupture for 2-grain bodies. For 3-grain bridges there is never an exceedingly high intergranular force of suction, reported in macro-scale experiments. For multiple-grain bodies there are two types of instabilities, depending on densitiy of the assembly and the Gaussian curvature (GC): at positive GC points it is thin-sheet instability, while at negative GC points instability is linked with air entry fingers, all associated with the split of assemblies into smaller isolated funicular, and eventually pendular bodies. The multi-grain bridges instabilities are linked to material drying cracking, the instabilities in 2 grain systems mean eventual loss of cohesion.

Constructing a new nigrostriatal pathway in the Parkinsonian model with bridged neural transplantation in substantia nigra.

PubMed

Zhou, F C; Chiang, Y H; Wang, Y

1996-11-01

The physical repair and restoration of a completely damaged pathway in the brain has not been achieved previously. In a previous study, using excitatory amino acid bridging and fetal neural transplantation, we demonstrated that a bridged mesencephalic transplant in the substantia nigra generated an artificial nerve pathway that reinnervated the striatum of 6-hydroxydopamine (6-OHDA)-lesioned rats. In the current study, we report that a bridged mesencephalic transplant can anatomically, neurochemically, and functionally reinstate the 6-OHDA-eradicated nigro-striatal pathway. An excitatory amino acid, kainic acid, laid down in a track during the transplant generated a trophic environment that effectively guided the robust growth of transplanted neuronal fibers in a bundle to innervate the distal striatum. Growth occurred at the remarkable speed of approximately 200 microm/d. Two separate and distinct types of dopamine (DA) innervation from the transplant have been achieved for the first time: (1) DA innervation of the striatum, and (2) DA innervation of the pars reticularis of the substantia nigra. In addition, neuronal tracing revealed that reciprocal connections were achieved. The grafted DA neurons in the SNr innervated the host's striatum, whereas the host's striatal neurons, in turn, innervated the graft within 3-8 weeks. Electrochemical volt- ammetry recording revealed the restoration of DA release and clearance in a broad striatal area associated with the DA reinnervation. Furthermore, the amphetamine-induced rotation was attenuated, which indicates that the artificial pathways were motor functional. This study provides additional evidences that our bridged transplantation technique is a potential means for the repair of a completely damaged neuronal pathway.

A description of Seismicity based on Non-extensive Statistical Physics: An introduction to Non-extensive Statistical Seismology.

NASA Astrophysics Data System (ADS)

Vallianatos, Filippos

2015-04-01

Despite the extreme complexity that characterizes earthquake generation process, simple phenomenology seems to apply in the collective properties of seismicity. The best known is the Gutenberg-Richter relation. Short and long-term clustering, power-law scaling and scale-invariance have been exhibited in the spatio-temporal evolution of seismicity providing evidence for earthquakes as a nonlinear dynamic process. Regarding the physics of "many" earthquakes and how this can be derived from first principles, one may wonder, how can the collective properties of a set formed by all earthquakes in a given region, be derived and how does the structure of seismicity depend on its elementary constituents - the earthquakes? What are these properties? The physics of many earthquakes has to be studied with a different approach than the physics of one earthquake making the use of statistical physics necessary to understand the collective properties of earthquakes. Then a natural question arises. What type of statistical physics is appropriate to commonly describe effects from the microscale and crack opening level to the level of large earthquakes? An answer to the previous question could be non-extensive statistical physics, introduced by Tsallis (1988), as the appropriate methodological tool to describe entities with (multi) fractal distributions of their elements and where long-range interactions or intermittency are important, as in fracturing phenomena and earthquakes. In the present work, we review some fundamental properties of earthquake physics and how these are derived by means of non-extensive statistical physics. The aim is to understand aspects of the underlying physics that lead to the evolution of the earthquake phenomenon introducing the new topic of non-extensive statistical seismology. This research has been funded by the European Union (European Social Fund) and Greek national resources under the framework of the "THALES Program: SEISMO FEAR HELLARC" project. References F. Vallianatos, "A non-extensive approach to risk assessment", Nat. Hazards Earth Syst. Sci., 9, 211-216, 2009 F. Vallianatos and P. Sammonds "Is plate tectonics a case of non-extensive thermodynamics?" Physica A: Statistical Mechanics and its Applications, 389 (21), 4989-4993, 2010, F. Vallianatos, G. Michas, G. Papadakis and P. Sammonds " A non extensive statistical physics view to the spatiotemporal properties of the June 1995, Aigion earthquake (M6.2) aftershock sequence (West Corinth rift, Greece)", Acta Geophysica, 60(3), 758-768, 2012 F. Vallianatos and L. Telesca, Statistical mechanics in earth physics and natural hazards (editorial), Acta Geophysica, 60, 3, 499-501, 2012 F. Vallianatos, G. Michas, G. Papadakis and A. Tzanis "Evidence of non-extensivity in the seismicity observed during the 2011-2012 unrest at the Santorini volcanic complex, Greece" Nat. Hazards Earth Syst. Sci.,13,177-185, 2013 F. Vallianatos and P. Sammonds, "Evidence of non-extensive statistical physics of the lithospheric instability approaching the 2004 Sumatran-Andaman and 2011 Honshu mega-earthquakes" Tectonophysics, 590 , 52-58, 2013 G. Papadakis, F. Vallianatos, P. Sammonds, " Evidence of Nonextensive Statistical Physics behavior of the Hellenic Subduction Zone seismicity" Tectonophysics, 608, 1037 -1048, 2013 G. Michas, F. Vallianatos, and P. Sammonds, Non-extensivity and long-range correlations in the earthquake activity at the West Corinth rift (Greece) Nonlin. Processes Geophys., 20, 713-724, 2013

On Ruch's Principle of Decreasing Mixing Distance in classical statistical physics

NASA Astrophysics Data System (ADS)

Busch, Paul; Quadt, Ralf

1990-10-01

Ruch's Principle of Decreasing Mixing Distance is reviewed as a statistical physical principle and its basic suport and geometric interpretation, the Ruch-Schranner-Seligman theorem, is generalized to be applicable to a large representative class of classical statistical systems.

Physics Teachers and Students: A Statistical and Historical Analysis of Women

NASA Astrophysics Data System (ADS)

Gregory, Amanda

2009-10-01

Historically, women have been denied an education comparable to that available to men. Since women have been allowed into institutions of higher learning, they have been studying and earning physics degrees. The aim of this poster is to discuss the statistical relationship between the number of women enrolled in university physics programs and the number of female physics faculty members. Special care has been given to examining the statistical data in the context of the social climate at the time that these women were teaching or pursuing their education.

Computational manufacturing as a bridge between design and production.

PubMed

Tikhonravov, Alexander V; Trubetskov, Michael K

2005-11-10

Computational manufacturing of optical coatings is a research area that can be placed between theoretical designing and practical manufacturing in the same way that computational physics can be placed between theoretical and experimental physics. Investigations in this area have been performed for more than 30 years under the name of computer simulation of manufacturing and monitoring processes. Our goal is to attract attention to the increasing importance of computational manufacturing at the current state of the art in the design and manufacture of optical coatings and to demonstrate possible applications of this research tool.

Computational manufacturing as a bridge between design and production

NASA Astrophysics Data System (ADS)

Tikhonravov, Alexander V.; Trubetskov, Michael K.

2005-11-01

Computational manufacturing of optical coatings is a research area that can be placed between theoretical designing and practical manufacturing in the same way that computational physics can be placed between theoretical and experimental physics. Investigations in this area have been performed for more than 30 years under the name of computer simulation of manufacturing and monitoring processes. Our goal is to attract attention to the increasing importance of computational manufacturing at the current state of the art in the design and manufacture of optical coatings and to demonstrate possible applications of this research tool.

A college of science: Bridging the gap between school and university

NASA Astrophysics Data System (ADS)

Rutherford, Margaret; Zietsman, Aletta

1992-12-01

Many tertiary institutions in South Africa have implemented schemes to help redress the unfair school educational system. This paper describes one such initiative to increase access and success of educationally disadvantaged students in science. The background of the College of Science and the success of its first intake of students is described with an emphasis on the physics component of the physical sciences course. Sixty six percent of the students passed all three courses in their first year with the most educationally disadvantaged showing the greatest gains.

Cognitive Issues in Learning Advanced Physics: An Example from Quantum Mechanics

NASA Astrophysics Data System (ADS)

Singh, Chandralekha; Zhu, Guangtian

2009-11-01

We are investigating cognitive issues in learning quantum mechanics in order to develop effective teaching and learning tools. The analysis of cognitive issues is particularly important for bridging the gap between the quantitative and conceptual aspects of quantum mechanics and for ensuring that the learning tools help students build a robust knowledge structure. We discuss the cognitive aspects of quantum mechanics that are similar or different from those of introductory physics and their implications for developing strategies to help students develop a good grasp of quantum mechanics.

Quantum Entanglement in Neural Network States

NASA Astrophysics Data System (ADS)

Deng, Dong-Ling; Li, Xiaopeng; Das Sarma, S.

2017-04-01

Machine learning, one of today's most rapidly growing interdisciplinary fields, promises an unprecedented perspective for solving intricate quantum many-body problems. Understanding the physical aspects of the representative artificial neural-network states has recently become highly desirable in the applications of machine-learning techniques to quantum many-body physics. In this paper, we explore the data structures that encode the physical features in the network states by studying the quantum entanglement properties, with a focus on the restricted-Boltzmann-machine (RBM) architecture. We prove that the entanglement entropy of all short-range RBM states satisfies an area law for arbitrary dimensions and bipartition geometry. For long-range RBM states, we show by using an exact construction that such states could exhibit volume-law entanglement, implying a notable capability of RBM in representing quantum states with massive entanglement. Strikingly, the neural-network representation for these states is remarkably efficient, in the sense that the number of nonzero parameters scales only linearly with the system size. We further examine the entanglement properties of generic RBM states by randomly sampling the weight parameters of the RBM. We find that their averaged entanglement entropy obeys volume-law scaling, and the meantime strongly deviates from the Page entropy of the completely random pure states. We show that their entanglement spectrum has no universal part associated with random matrix theory and bears a Poisson-type level statistics. Using reinforcement learning, we demonstrate that RBM is capable of finding the ground state (with power-law entanglement) of a model Hamiltonian with a long-range interaction. In addition, we show, through a concrete example of the one-dimensional symmetry-protected topological cluster states, that the RBM representation may also be used as a tool to analytically compute the entanglement spectrum. Our results uncover the unparalleled power of artificial neural networks in representing quantum many-body states regardless of how much entanglement they possess, which paves a novel way to bridge computer-science-based machine-learning techniques to outstanding quantum condensed-matter physics problems.

The Utility of a Physics Education in Science Policy

NASA Astrophysics Data System (ADS)

Roberts, Drew

2016-03-01

In order for regulators to create successful policies on technical issues, ranging from environmental protection to distribution of national Grant money, the scientific community must play an integral role in the legislative process. Through a summer-long internship with the Science, Space, and Technology Committee of the U.S. House of Representatives, I have learned that skills developed while pursuing an undergraduate degree in physics are very valuable in the policy realm. My physics education provided me the necessary tools to bridge the goals of the scientific and political communities. The need for effective comprehension and communication of technical subjects provides an important opportunity for individuals with physics degrees to make substantial contributions to government policy. Science policy should be encouraged as one of the many career pathways for physics students. Society of Physics Students, John and Jane Mather Foundation for Science and the Arts.

[Protective role of autotypic contacts under cerebellar neural net injury by toxic doses of NO-generative compounds].

PubMed

Samosudova, N V; Reutov, V P; Larionova, N P; Chaĭlakhian, L M

2005-01-01

In the present work, cerebellar neural net injury was induced by toxic doses of NO-generative compound (NaNO2). A protective role of glial cells was revealed in such conditions. The present results were compared with those of the previous work concerning the action of high concentration glutamate on the frog cerebellum (Samosudova et al., 1996). In both cases we observed the appearance of spiral-like structures--"wrappers)"--involving several rows of transformed glial processes with smaller width and bridges connecting the inner sides of row (autotypic contact). A statistic analysis was made according to both previous and present data. We calculated the number and width of rows, and intervals between bridges depending on experimental conditions. As the injury increased (stimulation in the NO-presence), the row number in "wrappers" also increased, while the row width and intervals between bridges decreased. The presence of autotypic contacts in glial "wrappers" enables us to suppose the involvement of adhesive proteins--cadherins in its formation. The obtained data suggested that the formation of spiral structures--"wrappers" may be regarded as a compensative-adaptive reaction on the injury of cerebellar neural net glutamate and NO-generative compounds.

Risk analysis of emergent water pollution accidents based on a Bayesian Network.

PubMed

Tang, Caihong; Yi, Yujun; Yang, Zhifeng; Sun, Jie

2016-01-01

To guarantee the security of water quality in water transfer channels, especially in open channels, analysis of potential emergent pollution sources in the water transfer process is critical. It is also indispensable for forewarnings and protection from emergent pollution accidents. Bridges above open channels with large amounts of truck traffic are the main locations where emergent accidents could occur. A Bayesian Network model, which consists of six root nodes and three middle layer nodes, was developed in this paper, and was employed to identify the possibility of potential pollution risk. Dianbei Bridge is reviewed as a typical bridge on an open channel of the Middle Route of the South to North Water Transfer Project where emergent traffic accidents could occur. Risk of water pollutions caused by leakage of pollutants into water is focused in this study. The risk for potential traffic accidents at the Dianbei Bridge implies a risk for water pollution in the canal. Based on survey data, statistical analysis, and domain specialist knowledge, a Bayesian Network model was established. The human factor of emergent accidents has been considered in this model. Additionally, this model has been employed to describe the probability of accidents and the risk level. The sensitive reasons for pollution accidents have been deduced. The case has also been simulated that sensitive factors are in a state of most likely to lead to accidents. Copyright © 2015 Elsevier Ltd. All rights reserved.

Investigation of cyano-bridged coordination nanoparticles Gd3+/[Fe(CN)6]3-/d-mannitol as T1-weighted MRI contrast agents

NASA Astrophysics Data System (ADS)

Perrier, M.; Gallud, A.; Ayadi, A.; Kennouche, S.; Porredon, C.; Gary-Bobo, M.; Larionova, J.; Goze-Bac, Ch.; Zanca, M.; Garcia, M.; Basile, I.; Long, J.; de Lapuente, J.; Borras, M.; Guari, Y.

2015-07-01

Cyano-bridged Gd3+/[Fe(CN)6]3- coordination polymer nanoparticles of 3-4 nm stabilized with d-mannitol presenting a high r1 relaxivity value of 11.4 mM-1 s-1 were investigated in vivo as contrast agents (CA) for Magnetic Resonance Imaging (MRI). They allow an increase of the MR image contrast and can act as an efficient intravascular T1 CA with a relatively long blood-circulation lifetime (60 min) without specific toxicity.Cyano-bridged Gd3+/[Fe(CN)6]3- coordination polymer nanoparticles of 3-4 nm stabilized with d-mannitol presenting a high r1 relaxivity value of 11.4 mM-1 s-1 were investigated in vivo as contrast agents (CA) for Magnetic Resonance Imaging (MRI). They allow an increase of the MR image contrast and can act as an efficient intravascular T1 CA with a relatively long blood-circulation lifetime (60 min) without specific toxicity. Electronic supplementary information (ESI) available: Experimental details and procedures, toxicological data, physical characterization. See DOI: 10.1039/c5nr01557j

Electron transport in molecular wires with transition metal contacts

NASA Astrophysics Data System (ADS)

Dalgleish, Hugh

A molecular wire is an organic molecule that forms a conducting bridge between electronic contacts. Single molecules are likely to be the smallest entities to conduct electricity and thus molecular wires present many interesting challenges to fundamental science as well as enormous potential for nanoelectronic technological applications. A particular challenge stems from the realization that the properties of molecular wires are strongly influenced by the combined characteristics of the molecule and the metal contacts. While gold has been the most studied contact material to date, interest in molecular wires with transition metal contacts that are electronically more complex than gold is growing. This thesis presents a theoretical investigation of electron transport and associated phenomena in molecular wires with transition metal contacts. An appropriate methodology is developed on the basis of Landauer theory and ab initio and semi-empirical considerations and new, physically important systems are identified. Spin-dependent transport mechanisms and device characteristics are explored for molecular wires with ferromagnetic iron contacts, systems that have not been considered previously, either theoretically or experimentally. Electron transport between iron point contacts bridged by iron atoms is also investigated. Spin-dependent transport is also studied for molecules bridging nickel contacts and a possible explanation of some experimentally observed phenomena is proposed. A novel physical phenomenon termed strong spin current rectification and a new controllable negative differential resistance mechanism with potential applications for molecular electronic technology are introduced. The phenomena predicted in this thesis should be accessible to present day experimental techniques and this work is intended to stimulate experiments directed at observing them. Keywords. molecular electronics; spintronics; electron transport; interface states.

PARAGON: A Systematic, Integrated Approach to Aerosol Observation and Modeling

NASA Technical Reports Server (NTRS)

Diner, David J.; Kahn, Ralph A.; Braverman, Amy J.; Davies, Roger; Martonchik, John V.; Menzies, Robert T.; Ackerman, Thomas P.; Seinfeld, John H.; Anderson, Theodore L.; Charlson, Robert J.;

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

Paavola, Janika; Hall, Michael J. W.; Paris, Matteo G. A.

The transition from quantum to classical, in the case of a quantum harmonic oscillator, is typically identified with the transition from a quantum superposition of macroscopically distinguishable states, such as the Schroedinger-cat state, into the corresponding statistical mixture. This transition is commonly characterized by the asymptotic loss of the interference term in the Wigner representation of the cat state. In this paper we show that the quantum-to-classical transition has different dynamical features depending on the measure for nonclassicality used. Measures based on an operatorial definition have well-defined physical meaning and allow a deeper understanding of the quantum-to-classical transition. Our analysismore » shows that, for most nonclassicality measures, the Schroedinger-cat state becomes classical after a finite time. Moreover, our results challenge the prevailing idea that more macroscopic states are more susceptible to decoherence in the sense that the transition from quantum to classical occurs faster. Since nonclassicality is a prerequisite for entanglement generation our results also bridge the gap between decoherence, which is lost only asymptotically, and entanglement, which may show a ''sudden death''. In fact, whereas the loss of coherences still remains asymptotic, we emphasize that the transition from quantum to classical can indeed occur at a finite time.« less

Understanding the influence of solvent field and fluctuations on the stability of photo-induced charge-separated state in molecular triad

NASA Astrophysics Data System (ADS)

Balamurugan, D.; Aquino, Adelia; Lischka, Hans; Dios, Francis; Flores, Lionel; Cheung, Margaret

2013-03-01

Molecular triad composed of fullerene, porphyrin, and carotene is an artificial analogue of natural photosynthetic system and is considered for applications in solar energy conversion because of its ability to produce long-lived photo-induced charge separated state. The goal of the present multiscale simulation is to understand how the stability of photo-induced charge-separated state in molecular triad is influenced by a polar organic solvent, namely tetrahydrofuran (THF). The multiscale approach is based on combined quantum, classical molecular dynamics, and statistical physics calculations. The quantum chemical calculations were performed on the triad using the second order algebraic diagrammatic perturbation and time-dependent density functional theory. Molecular dynamics simulations were performed on triad in a box of THF solvent with the replica exchange method. The two methods on different length and time scales are bridged through an important sampling technique. We have analyzed the free energy landscape, structural fluctuations, and the long- range electrostatic interactions between triad and solvent molecules. The results suggest that the polarity and re-organization of the solvent is critical in stabilization of charge-separated state in triad. Supported by DOE (DE-FG02-10ER16175)

Physical Applications of a Simple Approximation of Bessel Functions of Integer Order

ERIC Educational Resources Information Center

Barsan, V.; Cojocaru, S.

2007-01-01

Applications of a simple approximation of Bessel functions of integer order, in terms of trigonometric functions, are discussed for several examples from electromagnetism and optics. The method may be applied in the intermediate regime, bridging the "small values regime" and the "asymptotic" one, and covering, in this way, an area of great…

Reducing Adolescents' Perceived Barriers to Treatment and Increasing Help-Seeking Intentions: Effects of Classroom Presentations by General Practitioners

ERIC Educational Resources Information Center

Wilson, Coralie Joy; Deane, Frank P.; Marshall, Kellie L.; Dalley, Andrew

2008-01-01

The "Building Bridges to General Practice" (BBGP) program is an outreach initiative. It aims to reduce young peoples' perceived knowledge- and belief-based barriers to engaging in treatment and to increase their behavioral intentions to consult a general medical practitioner (GP) for physical and psychological problems. By increasing…

A Bridge between Two Important Problems in Optics and Electrostatics

ERIC Educational Resources Information Center

Capelli, R.; Pozzi, G.

2008-01-01

It is shown how the same physically appealing method can be applied to find analytic solutions for two difficult and apparently unrelated problems in optics and electrostatics. They are: (i) the diffraction of a plane wave at a perfectly conducting thin half-plane and (ii) the electrostatic field associated with a parallel array of stripes held at…

How Can Magnetic Forces Do Work? Investigating the Problem with Students

ERIC Educational Resources Information Center

Onorato, Pasquale; De Ambrosis, Anna

2013-01-01

We present a sequence of activities aimed at promoting both learning about magnetic forces and students' reflection about the conceptual bridge between magnetic forces on a moving charge and on a current-carrying wire in a magnetic field. The activity sequence, designed for students in high school or on introductory physics courses, has been…

Transfer of Life Skills in Sport-Based Youth Development Programs: A Conceptual Framework Bridging Learning to Application

ERIC Educational Resources Information Center

Jacobs, Jennifer M.; Wright, Paul M.

2018-01-01

Research has demonstrated that many quality sport-based youth development programs promote life skill acquisition (e.g., leadership, self-control) with the ultimate goal of facilitating positive outcomes in youth participants' social and academic environments. Researchers call this "transfer of life skills" (i.e., the idea that physical,…

Aazzhoogan: Red Lake Nation's Bridge to the Future

ERIC Educational Resources Information Center

King, Dan; McArthur, Eugene

2014-01-01

The Red Lake Band of Chippewa are investing in education and future generations with a new tribal college campus. The new Red Lake Nation College (RLNC) campus in northern Minnesota will greatly improve not only the college's physical appearance, but will also elevate the community's sense of pride and self-esteem. The impact of the new campus…

Bridging the Gap between Educational Needs for Development and Current Education Systems in Sylhet

ERIC Educational Resources Information Center

Rahaman, Mohammad Mizenur; Chowdhury, Mosaddak Ahmed

2016-01-01

Education builds a nation. National development highly depends on Education. Education is the main component to execute the vision of the nation. The Global scenario of socio-economic development is changing while knowledge supplants physical capital as the source of present (and future) wealth. Sylhet is far better that other division of the…

Gender Differences in Health Risk Behaviors and Physical Activity among Middle School Students

ERIC Educational Resources Information Center

Wu, Tsu-Yin; Rose, Sherry E.; Bancroft, Joanna M.

2006-01-01

Adolescence is a period of accelerated growth and change, bridging the complex transition from childhood to adulthood. This period offers adolescents an opportunity to begin planning for their futures and to adopt healthy attitudes about risk behaviors that can continue into adulthood, thus setting the stage for a lifetime of desirable health…

An Overview of the Computational Physics and Methods Group at Los Alamos National Laboratory

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

Baker, Randal Scott

CCS Division was formed to strengthen the visibility and impact of computer science and computational physics research on strategic directions for the Laboratory. Both computer science and computational science are now central to scientific discovery and innovation. They have become indispensable tools for all other scientific missions at the Laboratory. CCS Division forms a bridge between external partners and Laboratory programs, bringing new ideas and technologies to bear on today’s important problems and attracting high-quality technical staff members to the Laboratory. The Computational Physics and Methods Group CCS-2 conducts methods research and develops scientific software aimed at the latest andmore » emerging HPC systems.« less

Nondestructive ultrasonic testing of materials

DOEpatents

Hildebrand, Bernard P.

1994-01-01

Reflection wave forms obtained from aged and unaged material samples can be compared in order to indicate trends toward age-related flaws. Statistical comparison of a large number of data points from such wave forms can indicate changes in the microstructure of the material due to aging. The process is useful for predicting when flaws may occur in structural elements of high risk structures such as nuclear power plants, airplanes, and bridges.

Nondestructive ultrasonic testing of materials

DOEpatents

Hildebrand, B.P.

1994-08-02

Reflection wave forms obtained from aged and unaged material samples can be compared in order to indicate trends toward age-related flaws. Statistical comparison of a large number of data points from such wave forms can indicate changes in the microstructure of the material due to aging. The process is useful for predicting when flaws may occur in structural elements of high risk structures such as nuclear power plants, airplanes, and bridges. 4 figs.

Do People Take Stimulus Correlations into Account in Visual Search (Open Source)

DTIC Science & Technology

2016-03-10

RESEARCH ARTICLE Do People Take Stimulus Correlations into Account in Visual Search ? Manisha Bhardwaj1, Ronald van den Berg2,3, Wei Ji Ma2,4...visual search experiments, distractors are often statistically independent of each other. However, stimuli in more naturalistic settings are often...contribute to bridging the gap between artificial and natural visual search tasks. Introduction Visual target detection in displays consisting of multiple

Incorporating physically-based microstructures in materials modeling: Bridging phase field and crystal plasticity frameworks

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

Lim, Hojun; Abdeljawad, Fadi; Owen, Steven J.

Here, the mechanical properties of materials systems are highly influenced by various features at the microstructural level. The ability to capture these heterogeneities and incorporate them into continuum-scale frameworks of the deformation behavior is considered a key step in the development of complex non-local models of failure. In this study, we present a modeling framework that incorporates physically-based realizations of polycrystalline aggregates from a phase field (PF) model into a crystal plasticity finite element (CP-FE) framework. Simulated annealing via the PF model yields ensembles of materials microstructures with various grain sizes and shapes. With the aid of a novel FEmore » meshing technique, FE discretizations of these microstructures are generated, where several key features, such as conformity to interfaces, and triple junction angles, are preserved. The discretizations are then used in the CP-FE framework to simulate the mechanical response of polycrystalline α-iron. It is shown that the conformal discretization across interfaces reduces artificial stress localization commonly observed in non-conformal FE discretizations. The work presented herein is a first step towards incorporating physically-based microstructures in lieu of the overly simplified representations that are commonly used. In broader terms, the proposed framework provides future avenues to explore bridging models of materials processes, e.g. additive manufacturing and microstructure evolution of multi-phase multi-component systems, into continuum-scale frameworks of the mechanical properties.« less

A perspective on bridging scales and design of models using low-dimensional manifolds and data-driven model inference

PubMed Central

Zenil, Hector; Kiani, Narsis A.; Ball, Gordon; Gomez-Cabrero, David

2016-01-01

Systems in nature capable of collective behaviour are nonlinear, operating across several scales. Yet our ability to account for their collective dynamics differs in physics, chemistry and biology. Here, we briefly review the similarities and differences between mathematical modelling of adaptive living systems versus physico-chemical systems. We find that physics-based chemistry modelling and computational neuroscience have a shared interest in developing techniques for model reductions aiming at the identification of a reduced subsystem or slow manifold, capturing the effective dynamics. By contrast, as relations and kinetics between biological molecules are less characterized, current quantitative analysis under the umbrella of bioinformatics focuses on signal extraction, correlation, regression and machine-learning analysis. We argue that model reduction analysis and the ensuing identification of manifolds bridges physics and biology. Furthermore, modelling living systems presents deep challenges as how to reconcile rich molecular data with inherent modelling uncertainties (formalism, variables selection and model parameters). We anticipate a new generative data-driven modelling paradigm constrained by identified governing principles extracted from low-dimensional manifold analysis. The rise of a new generation of models will ultimately connect biology to quantitative mechanistic descriptions, thereby setting the stage for investigating the character of the model language and principles driving living systems. This article is part of the themed issue ‘Multiscale modelling at the physics–chemistry–biology interface’. PMID:27698038

Incorporating physically-based microstructures in materials modeling: Bridging phase field and crystal plasticity frameworks

DOE PAGES

Lim, Hojun; Abdeljawad, Fadi; Owen, Steven J.; ...

2016-04-25

Here, the mechanical properties of materials systems are highly influenced by various features at the microstructural level. The ability to capture these heterogeneities and incorporate them into continuum-scale frameworks of the deformation behavior is considered a key step in the development of complex non-local models of failure. In this study, we present a modeling framework that incorporates physically-based realizations of polycrystalline aggregates from a phase field (PF) model into a crystal plasticity finite element (CP-FE) framework. Simulated annealing via the PF model yields ensembles of materials microstructures with various grain sizes and shapes. With the aid of a novel FEmore » meshing technique, FE discretizations of these microstructures are generated, where several key features, such as conformity to interfaces, and triple junction angles, are preserved. The discretizations are then used in the CP-FE framework to simulate the mechanical response of polycrystalline α-iron. It is shown that the conformal discretization across interfaces reduces artificial stress localization commonly observed in non-conformal FE discretizations. The work presented herein is a first step towards incorporating physically-based microstructures in lieu of the overly simplified representations that are commonly used. In broader terms, the proposed framework provides future avenues to explore bridging models of materials processes, e.g. additive manufacturing and microstructure evolution of multi-phase multi-component systems, into continuum-scale frameworks of the mechanical properties.« less

Clinical Outcomes of Modified Mason-Allen Single-Row Repair for Bursal-Sided Partial-Thickness Rotator Cuff Tears: Comparison With the Double-Row Suture-Bridge Technique.

PubMed

Shin, Sang-Jin; Kook, Seung-Hwan; Rao, Nandan; Seo, Myeong-Jae

2015-08-01

Various repair techniques have been reported for the operative treatment of bursal-sided partial-thickness rotator cuff tears. Recently, arthroscopic single-row repair using a modified Mason-Allen technique has been introduced. The arthroscopic, modified Mason-Allen single-row technique with preservation of the articular-sided tendon provides satisfactory clinical outcomes and similar results to the double-row suture-bridge technique after conversion of a partial-thickness tear to a full-thickness tear. Cohort study; Level of evidence, 3. A retrospective study was conducted on 84 consecutive patients with symptomatic, bursal-sided partial-thickness rotator cuff tears involving more than 50% thickness of the tendon. A total of 47 patients were treated by the modified Mason-Allen single-row repair technique, preserving the articular-sided tendon, and 37 patients were treated by the double-row suture-bridge repair technique after conversion to a full-thickness tear. The clinical and functional outcomes were evaluated using the American Shoulder and Elbow Surgeons (ASES) and Constant scores and a visual analog scale (VAS) for pain and satisfaction of patients. Magnetic resonance imaging (MRI) was used to analyze the integrity of tendons at 6-month follow-up. Patients were followed up for a mean of 32.5 months. In the 47 patients treated with the modified Mason-Allen suture technique, the VAS score decreased from a preoperative mean of 5.3 ± 0.3 to 0.9 ± 0.5 at the time of final follow-up. There was a statistically significant increase in the mean ASES score (from 45.4 ± 2.9 to 88.6 ± 4.5) and mean Constant score (from 66.9 ± 2.6 to 88.1 ± 2.4) (P < .001). Four of 47 patients (8.5%) demonstrated retears at 6-month postoperative MRI. There was no statistical difference in terms of functional outcomes and the retear rate compared with those of patients with the suture-bridge repair technique (3 patients, 8.1%). However, the mean number of suture anchors used in the patients with modified Mason-Allen suture repair (1.2 ± 0.4) was significantly fewer than that in the patients with suture-bridge repair (3.2 ± 0.4) (P < .01). The modified Mason-Allen single-row repair technique that preserved the articular-sided tendon provided satisfactory clinical outcomes in patients with symptomatic, bursal-sided partial-thickness rotator cuff tears. Despite a fewer number of suture anchors, the shoulder functional outcomes and retear rate in patients after modified Mason-Allen repair were comparable with those of patients who underwent double-row suture-bridge repair. Therefore, the modified Mason-Allen single-row repair technique using a triple-loaded suture anchor can be considered as an effective treatment in patients with bursal-sided partial-thickness rotator cuff tears. © 2015 The Author(s).

Use of surface-geophysical methods to assess riverbed scour at bridge piers

USGS Publications Warehouse

Gorin, S.R.; Haeni, F.P.

1989-01-01

A ground-penetrating-radar system, and three seismic systems--color fathometer, tuned transducer, and black-and-white fathometer--were used to evaluate river-bed scour at the Charter Oak, Founder 's and Bulkeley Bridges in Hartford, Connecticut. Cross-sections of the channel and some lateral sections were run at each bridge in June and July 1987, and significant scour at piers supporting each of these bridges was recorded. Each of the four geophysical systems proved to have advantages and limitations. The ground penetrating radar system used single and dual 80 megahertz antennae floating in the water to transmit and receive the signal. The method was successful in water less than 25 ft deep, and in resistive earth materials. The geometry of existing scour holes and the extent of post-scour sedimentation were clearly defined. The color fathometer, operating at a signal frequency of 20 kilohertz, delineated existing scour-hole geometry, detected infilling of scour holes, and provided qualitative information about the physical properties of sediments. The tuned transducer, operating at a signal frequency of 14 kilohertz, defined scour-hole geometry and the extent of post-scour sediment deposition. Both of these systems were effective in water greater than 5 ft deep. At a signal frequency of 200 kilohertz, the black-and-white fathometer could not penetrate post-scour deposits, but it was useful in defining existing scour-holed geometry in water of any depth. (USGS)

Data Acquisition and Preprocessing in Studies on Humans: What Is Not Taught in Statistics Classes?

PubMed

Zhu, Yeyi; Hernandez, Ladia M; Mueller, Peter; Dong, Yongquan; Forman, Michele R

2013-01-01

The aim of this paper is to address issues in research that may be missing from statistics classes and important for (bio-)statistics students. In the context of a case study, we discuss data acquisition and preprocessing steps that fill the gap between research questions posed by subject matter scientists and statistical methodology for formal inference. Issues include participant recruitment, data collection training and standardization, variable coding, data review and verification, data cleaning and editing, and documentation. Despite the critical importance of these details in research, most of these issues are rarely discussed in an applied statistics program. One reason for the lack of more formal training is the difficulty in addressing the many challenges that can possibly arise in the course of a study in a systematic way. This article can help to bridge this gap between research questions and formal statistical inference by using an illustrative case study for a discussion. We hope that reading and discussing this paper and practicing data preprocessing exercises will sensitize statistics students to these important issues and achieve optimal conduct, quality control, analysis, and interpretation of a study.

Streamstats: U.S. Geological Survey Web Application for Streamflow Statistics for Connecticut

USGS Publications Warehouse

Ahearn, Elizabeth A.; Ries, Kernell G.; Steeves, Peter A.

2006-01-01

Introduction An important mission of the U. S. Geological Survey (USGS) is to provide information on streamflow in the Nation's rivers. Streamflow statistics are used by water managers, engineers, scientists, and others to protect people and property during floods and droughts, and to manage land, water, and biological resources. Common uses for streamflow statistics include dam, bridge, and culvert design; water-supply planning and management; water-use appropriations and permitting; wastewater and industrial discharge permitting; hydropower-facility design and regulation; and flood-plain mapping for establishing flood-insurance rates and land-use zones. In an effort to improve access to published streamflow statistics, and to make the process of computing streamflow statistics for ungaged stream sites easier, more accurate, and more consistent, the USGS and the Environmental Systems Research Institute, Inc. (ESRI) developed StreamStats (Ries and others, 2004). StreamStats is a Geographic Information System (GIS)-based Web application for serving previously published streamflow statistics and basin characteristics for USGS data-collection stations, and computing streamflow statistics and basin characteristics for ungaged stream sites. The USGS, in cooperation with the Connecticut Department of Environmental Protection and the Connecticut Department of Transportation, has implemented StreamStats for Connecticut.

Mediation analysis in nursing research: a methodological review.

PubMed

Liu, Jianghong; Ulrich, Connie

2016-12-01

Mediation statistical models help clarify the relationship between independent predictor variables and dependent outcomes of interest by assessing the impact of third variables. This type of statistical analysis is applicable for many clinical nursing research questions, yet its use within nursing remains low. Indeed, mediational analyses may help nurse researchers develop more effective and accurate prevention and treatment programs as well as help bridge the gap between scientific knowledge and clinical practice. In addition, this statistical approach allows nurse researchers to ask - and answer - more meaningful and nuanced questions that extend beyond merely determining whether an outcome occurs. Therefore, the goal of this paper is to provide a brief tutorial on the use of mediational analyses in clinical nursing research by briefly introducing the technique and, through selected empirical examples from the nursing literature, demonstrating its applicability in advancing nursing science.

Statistical Optimality in Multipartite Ranking and Ordinal Regression.

PubMed

Uematsu, Kazuki; Lee, Yoonkyung

2015-05-01

Statistical optimality in multipartite ranking is investigated as an extension of bipartite ranking. We consider the optimality of ranking algorithms through minimization of the theoretical risk which combines pairwise ranking errors of ordinal categories with differential ranking costs. The extension shows that for a certain class of convex loss functions including exponential loss, the optimal ranking function can be represented as a ratio of weighted conditional probability of upper categories to lower categories, where the weights are given by the misranking costs. This result also bridges traditional ranking methods such as proportional odds model in statistics with various ranking algorithms in machine learning. Further, the analysis of multipartite ranking with different costs provides a new perspective on non-smooth list-wise ranking measures such as the discounted cumulative gain and preference learning. We illustrate our findings with simulation study and real data analysis.

Useful and Usable Climate Science: Frameworks for Bridging the Social and Physical domains.

NASA Astrophysics Data System (ADS)

Buja, L.

2016-12-01

Society is transforming the Earth's system in unprecedented ways, often with significant variations across space and time. In turn, the impacts of climate change on the human system vary dramatically due to differences in cultural, socioeconomic, institutional, and physical processes at the local level. The Climate Science and Applications Program (CSAP) at the National Center for Atmospheric Research in Boulder Colorado addresses societal vulnerability, impacts and adaptation to climate change through the development of frameworks and methods for analyzing current and future vulnerability, and integrated analyses of climate impacts and adaptation at local, regional and global scales. CSAP relies heavily on GIS-based scientific data and knowledge systems to bridge social and physical science approaches in its five focus areas: Governance of inter-linked natural and managed resource systems. The role of urban areas in driving emissions of climate change Weather, climate and global human health, GIS-based science data & knowledge systems. Regional Climate Science and Services for Adaptation Advanced methodologies and frameworks for assessing current and future risks to environmental hazards through the integration of physical and social science models, research results, and remote sensing data are presented in the context of recent national and international projects on climate change and food/water security, urban carbon emissions, metropolitan extreme heat and global health. In addition, innovative CSAP international capacity building programs teaching interdisciplinary approaches for using geospatial technologies to integrate multi-scale spatial information of weather, climate change into important sectors such as disaster reduction, agriculture, tourism and society for decision-making are discussed.

Physics-based statistical model and simulation method of RF propagation in urban environments

DOEpatents

Pao, Hsueh-Yuan; Dvorak, Steven L.

2010-09-14

A physics-based statistical model and simulation/modeling method and system of electromagnetic wave propagation (wireless communication) in urban environments. In particular, the model is a computationally efficient close-formed parametric model of RF propagation in an urban environment which is extracted from a physics-based statistical wireless channel simulation method and system. The simulation divides the complex urban environment into a network of interconnected urban canyon waveguides which can be analyzed individually; calculates spectral coefficients of modal fields in the waveguides excited by the propagation using a database of statistical impedance boundary conditions which incorporates the complexity of building walls in the propagation model; determines statistical parameters of the calculated modal fields; and determines a parametric propagation model based on the statistical parameters of the calculated modal fields from which predictions of communications capability may be made.

MOSFiT: Modular Open Source Fitter for Transients

NASA Astrophysics Data System (ADS)

Guillochon, James; Nicholl, Matt; Villar, V. Ashley; Mockler, Brenna; Narayan, Gautham; Mandel, Kaisey S.; Berger, Edo; Williams, Peter K. G.

2018-05-01

Much of the progress made in time-domain astronomy is accomplished by relating observational multiwavelength time-series data to models derived from our understanding of physical laws. This goal is typically accomplished by dividing the task in two: collecting data (observing), and constructing models to represent that data (theorizing). Owing to the natural tendency for specialization, a disconnect can develop between the best available theories and the best available data, potentially delaying advances in our understanding new classes of transients. We introduce MOSFiT: the Modular Open Source Fitter for Transients, a Python-based package that downloads transient data sets from open online catalogs (e.g., the Open Supernova Catalog), generates Monte Carlo ensembles of semi-analytical light-curve fits to those data sets and their associated Bayesian parameter posteriors, and optionally delivers the fitting results back to those same catalogs to make them available to the rest of the community. MOSFiT is designed to help bridge the gap between observations and theory in time-domain astronomy; in addition to making the application of existing models and creation of new models as simple as possible, MOSFiT yields statistically robust predictions for transient characteristics, with a standard output format that includes all the setup information necessary to reproduce a given result. As large-scale surveys such as that conducted with the Large Synoptic Survey Telescope (LSST), discover entirely new classes of transients, tools such as MOSFiT will be critical for enabling rapid comparison of models against data in statistically consistent, reproducible, and scientifically beneficial ways.

Characterization of Stormwater Runoff from a Light Rail Transit Area.

PubMed

Sajjad, Raja Umer; Kim, Kyoung Jin; Memon, Sheeraz; Sukhbaatar, Chinzorig; Paule, Ma Cristina; Lee, Bum-Yeon; Lee, Chang-Hee

2015-09-01

The monitoring of stormwater runoff from Light Rail Transit (LRT) facilities is insufficient in many regions around the world. In this study, runoff quality and quantity were monitored during operational and non-operational LRT phases during 2010-2013. The event mean concentration (EMC) of pollutants showed little statistical variability during both phases. The antecedent dry day (ADD) showed a strong to moderate positive correlation with most pollutant EMCs during the non-operational phase. The existence and magnitude of the first flush from LRT runoff was found to be similar to those from other transportation land uses. The comparison of LRT runoff data with an adjacent road bridge site showed that the pollutant EMC and unit load were 2 to 9 times higher from the road bridge. It was suggested that LRT automated operation and the elevated track makes this transportation mode a viable option for the management of non-point source pollution.

Bayesian Group Bridge for Bi-level Variable Selection.

PubMed

Mallick, Himel; Yi, Nengjun

2017-06-01

A Bayesian bi-level variable selection method (BAGB: Bayesian Analysis of Group Bridge) is developed for regularized regression and classification. This new development is motivated by grouped data, where generic variables can be divided into multiple groups, with variables in the same group being mechanistically related or statistically correlated. As an alternative to frequentist group variable selection methods, BAGB incorporates structural information among predictors through a group-wise shrinkage prior. Posterior computation proceeds via an efficient MCMC algorithm. In addition to the usual ease-of-interpretation of hierarchical linear models, the Bayesian formulation produces valid standard errors, a feature that is notably absent in the frequentist framework. Empirical evidence of the attractiveness of the method is illustrated by extensive Monte Carlo simulations and real data analysis. Finally, several extensions of this new approach are presented, providing a unified framework for bi-level variable selection in general models with flexible penalties.

The impact of care management information technology model on quality of care after percutaneous coronary intervention: "Bridging the Divides".

PubMed

Weintraub, William S; Fanari, Zaher; Elliott, Daniel; Ostertag-Stretch, Jennifer; Muther, Ann; Lynahan, Margaret; Kerzner, Roger; Salam, Tabassum; Scherrer, Herbert; Anderson, Sharon; Russo, Carla A; Kolm, Paul; Steinberg, Terri H

2017-07-03

Reducing readmissions and improving metrics of care are a national priority. Supplementing traditional care with care management may improve outcomes. The Bridges program was an initial evaluation of a care management platform (CareLinkHub), supported by information technology (IT) developed to improve the quality and transition of care from hospital to home after percutaneous coronary intervention (PCI) and reduce readmissions. CareLink is comprised of care managers, patient navigators, pharmacists and physicians. Information to guide care management is guided by a middleware layer to gather information, PLR (ColdLight Solutions, LLC) and presented to CareLink staff on a care management platform, Aerial™ (Medecision). An additional analytic engine [Neuron™ (ColdLight Solutions, LLC)] helps, evaluates and guide care. The "Bridges" program enrolled a total of 2054 PCI patients with 2835 admission from April, 1st 2013 through March 1st, 2015. The data of the program was compared with those of 3691 PCI patients with 4414 admissions in the 3years prior to the program. No impact was seen with respect to inpatient and observation readmission, or emergency department visits. Similarly no change was noticed in LDL control. There was minimal improvement in BP control and only in the CTM-3 and SAQ-7 physical limitation scores in the patients' reported outcomes. Patient follow-up with physicians within 1week of discharge improved during the Bridges years. The CareLink hub platform was successfully implemented. Little or no impact on outcome metrics was seen in the short follow-up time. The Bridges program suggests that population health management must be a long-term goal, improving preventive care in the community. Copyright © 2017 Elsevier Inc. All rights reserved.

An Integrated, Statistical Molecular Approach to the Physical Chemistry Curriculum

ERIC Educational Resources Information Center

Cartier, Stephen F.

2009-01-01

As an alternative to the "thermodynamics first" or "quantum first" approaches to the physical chemistry curriculum, the statistical definition of entropy and the Boltzmann distribution are introduced in the first days of the course and the entire two-semester curriculum is then developed from these concepts. Once the tools of statistical mechanics…

Statistical methods for investigating quiescence and other temporal seismicity patterns

USGS Publications Warehouse

Matthews, M.V.; Reasenberg, P.A.

1988-01-01

We propose a statistical model and a technique for objective recognition of one of the most commonly cited seismicity patterns:microearthquake quiescence. We use a Poisson process model for seismicity and define a process with quiescence as one with a particular type of piece-wise constant intensity function. From this model, we derive a statistic for testing stationarity against a 'quiescence' alternative. The large-sample null distribution of this statistic is approximated from simulated distributions of appropriate functionals applied to Brownian bridge processes. We point out the restrictiveness of the particular model we propose and of the quiescence idea in general. The fact that there are many point processes which have neither constant nor quiescent rate functions underscores the need to test for and describe nonuniformity thoroughly. We advocate the use of the quiescence test in conjunction with various other tests for nonuniformity and with graphical methods such as density estimation. ideally these methods may promote accurate description of temporal seismicity distributions and useful characterizations of interesting patterns. ?? 1988 Birkha??user Verlag.

Bringing the Maker Movement to School. Fourth Grade Students Create Projects to Illustrate the Transfer and Transformation of Energy

ERIC Educational Resources Information Center

Smith, Wendy; Smith, Brian C.

2016-01-01

The Maker Movement allows students to strengthen humanistic values through projects and experiences that require the use of their heads, hearts, and hands. Students are introduced to creative technologies that bridge the digital and physical worlds. Through whimsical projects, students take an interest in the concepts and ideas that might normally…

Articulation of Spatial and Geometrical Knowledge in Problem Solving with Technology at Primary School

ERIC Educational Resources Information Center

Soury-Lavergne, Sophie; Maschietto, Michela

2015-01-01

Our paper focuses on the relationship between spatial and geometrical knowledge in problem solving situations at primary school. We have created tasks that involve three different spaces: physical space, graphical space and geometrical space. We aim to study the specific role of graphical space as a bridge between the other two spaces using paper…

Didactic Model--Bridging a Concept with Phenomena

ERIC Educational Resources Information Center

Shternberg, Beba; Yerushalmy, Michal

2004-01-01

The article focuses on a specific method of constructing the concept of function. The core of this method is a didactic model that plays two roles together--on the one hand a role of a model of the concept of function and on the other hand a role of a model of physical phenomena that functions can represent. This synergy of modeling situations and…

Geometry modeling and grid generation using 3D NURBS control volume

NASA Technical Reports Server (NTRS)

Yu, Tzu-Yi; Soni, Bharat K.; Shih, Ming-Hsin

1995-01-01

The algorithms for volume grid generation using NURBS geometric representation are presented. The parameterization algorithm is enhanced to yield a desired physical distribution on the curve, surface and volume. This approach bridges the gap between CAD surface/volume definition and surface/volume grid generation. Computational examples associated with practical configurations have shown the utilization of these algorithms.

Effects of preprocessing Landsat MSS data on derived features

NASA Technical Reports Server (NTRS)

Parris, T. M.; Cicone, R. C.

1983-01-01

Important to the use of multitemporal Landsat MSS data for earth resources monitoring, such as agricultural inventories, is the ability to minimize the effects of varying atmospheric and satellite viewing conditions, while extracting physically meaningful features from the data. In general, the approaches to the preprocessing problem have been derived from either physical or statistical models. This paper compares three proposed algorithms; XSTAR haze correction, Color Normalization, and Multiple Acquisition Mean Level Adjustment. These techniques represent physical, statistical, and hybrid physical-statistical models, respectively. The comparisons are made in the context of three feature extraction techniques; the Tasseled Cap, the Cate Color Cube. and Normalized Difference.

Wave Interactions and Fluid Flows

NASA Astrophysics Data System (ADS)

Craik, Alex D. D.

1988-07-01

This up-to-date and comprehensive account of theory and experiment on wave-interaction phenomena covers fluids both at rest and in their shear flows. It includes, on the one hand, water waves, internal waves, and their evolution, interaction, and associated wave-driven means flow and, on the other hand, phenomena on nonlinear hydrodynamic stability, especially those leading to the onset of turbulence. This study provide a particularly valuable bridge between these two similar, yet different, classes of phenomena. It will be of value to oceanographers, meteorologists, and those working in fluid mechanics, atmospheric and planetary physics, plasma physics, aeronautics, and geophysical and astrophysical fluid dynamics.

Some Research Centers for Plasma Physics and Solid State Physics in the Netherlands and Belgium. Part II. Belgium,

DTIC Science & Technology

plasma column and observed the interesting phenomenon of plasma ejection. At FUB, Balescu and Prigogine direct a group of sixty theoreticians doing...outstanding work in statistical physics. Balescu is writing another graduate textbook on non-equilibrium statistical mechanics. He is tackling the

Physics in Perspective Volume II, Part C, Statistical Data.

ERIC Educational Resources Information Center

National Academy of Sciences - National Research Council, Washington, DC. Physics Survey Committee.

Statistical data relating to the sociology and economics of the physics enterprise are presented and explained. The data are divided into three sections: manpower data, data on funding and costs, and data on the literature of physics. Each section includes numerous studies, with notes on the sources and types of data, gathering procedures, and…

Left Ventricular Assist Device as a Bridge to Recovery for Patients With Advanced Heart Failure.

PubMed

Jakovljevic, Djordje G; Yacoub, Magdi H; Schueler, Stephan; MacGowan, Guy A; Velicki, Lazar; Seferovic, Petar M; Hothi, Sandeep; Tzeng, Bing-Hsiean; Brodie, David A; Birks, Emma; Tan, Lip-Bun

2017-04-18

Left ventricular assist devices (LVADs) have been used as an effective therapeutic option in patients with advanced heart failure, either as a bridge to transplantation, as destination therapy, or in some patients, as a bridge to recovery. This study evaluated whether patients undergoing an LVAD bridge-to-recovery protocol can achieve cardiac and physical functional capacities equivalent to those of healthy controls. Fifty-eight male patients-18 implanted with a continuous-flow LVAD, 16 patients with LVAD explanted (recovered patients), and 24 heart transplant candidates (HTx)-and 97 healthy controls performed a maximal graded cardiopulmonary exercise test with continuous measurements of respiratory gas exchange and noninvasive (rebreathing) hemodynamic data. Cardiac function was represented by peak exercise cardiac power output (mean arterial blood pressure × cardiac output) and functional capacity by peak exercise O 2 consumption. All patients demonstrated a significant exertional effort as demonstrated with the mean peak exercise respiratory exchange ratio >1.10. Peak exercise cardiac power output was significantly higher in healthy controls and explanted LVAD patients compared with other patients (healthy 5.35 ± 0.95 W; explanted 3.45 ± 0.72 W; LVAD implanted 2.37 ± 0.68 W; and HTx 1.31 ± 0.31 W; p < 0.05), as was peak O 2 consumption (healthy 36.4 ± 10.3 ml/kg/min; explanted 29.8 ± 5.9 ml/kg/min; implanted 20.5 ± 4.3 ml/kg/min; and HTx 12.0 ± 2.2 ml/kg/min; p < 0.05). In the LVAD explanted group, 38% of the patients achieved peak cardiac power output and 69% achieved peak O 2 consumption within the ranges of healthy controls. The authors have shown that a substantial number of patients who recovered sufficiently to allow explantation of their LVAD can even achieve cardiac and physical functional capacities nearly equivalent to those of healthy controls. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Quantifying reinforced concrete bridge deck deterioration using ground penetrating radar

NASA Astrophysics Data System (ADS)

Martino, Nicole Marie

Bridge decks are deteriorating at an alarming rate due to corrosion of the reinforcing steel, requiring billions of dollars to repair and replace them. Furthermore, the techniques used to assess the decks don't provide enough quantitative information. In recent years, ground penetrating radar (GPR) has been used to quantify deterioration by comparing the rebar reflection amplitudes to technologies serving as ground truth, because there is not an available amplitude threshold to distinguish healthy from corroded areas using only GPR. The goal of this research is to understand the relationship between GPR and deck deterioration, and develop a model to determine deterioration quantities with GPR alone. The beginning of this research determines that not only is the relationship between GPR and rebar corrosion stronger than the relationship between GPR and delaminations, but that the two are exceptionally correlated (90.2% and 86.6%). Next, multiple bridge decks were assessed with GPR and half-cell potential (HCP). Statistical parameters like the mean and skewness were computed for the GPR amplitudes of each deck, and coupled with actual corrosion quantities based on the HCP measurements to form a future bridge deck model that can be used to assess any deck with GPR alone. Finally, in order to understand exactly which component of rebar corrosion (rust, cracking or chloride) attenuates the GPR data, computational modeling was carried out to isolate each variable. The results indicate that chloride is the major contributor to the rebar reflection attenuation, and that computational modeling can be used to accurately simulate GPR attenuation due to chloride.

Second-chance university admission, the theory of planned behaviour and student achievement

NASA Astrophysics Data System (ADS)

Alas, Yabit; Anshari, Muhammad; Sabtu, Norakmarul Ihsan; Yunus, Norazmah

2016-06-01

The theory of planned behaviour attempts to explain factors which influence behaviour. One of these factors is intention. Positive or negative intentions are formed by a person's impression of the way other people would perceive similar behaviour (external forces). The authors of this study used the theory of planned behaviour to examine, compare and interpret the academic performance of students entering a university either via direct intake or via a bridging programme. This study focuses on the UniBridge programme offered by Universiti Brunei Darussalam (UBD), which is an intensive one-semester course that prepares students for undergraduate-level study. While direct-intake applicants pass minimum requirements for entry and are able to enrol directly into an undergraduate programme, applicants who do not meet these minimum requirements can join this bridging programme which is designed to be a "second-chance" entry option. Using a mixed-methods approach, the authors subjected student performance data of both direct-intake and bridge-programme undergraduates to statistical analyses, carried out interviews and then used the theoretical framework of planned behaviour to pinpoint individual attitudes and social pressures which form an intention to prepare for entry examinations. The results were mostly consistent and showed that the two groups were competitive in terms of undergraduate academic achievement, thus proving the second-chance programme to be effective in enabling students with poor A-Level results to experience academic confidence at university level. On the strength of these findings, the authors conclude their paper with recommendations for tertiary institutions to support lifelong learning initiatives through the use of multiple channels of entry.

Hunting Solomonoff's Swans: Exploring the Boundary Between Physics and Statistics in Hydrological Modeling

NASA Astrophysics Data System (ADS)

Nearing, G. S.

2014-12-01

Statistical models consistently out-perform conceptual models in the short term, however to account for a nonstationary future (or an unobserved past) scientists prefer to base predictions on unchanging and commutable properties of the universe - i.e., physics. The problem with physically-based hydrology models is, of course, that they aren't really based on physics - they are based on statistical approximations of physical interactions, and we almost uniformly lack an understanding of the entropy associated with these approximations. Thermodynamics is successful precisely because entropy statistics are computable for homogeneous (well-mixed) systems, and ergodic arguments explain the success of Newton's laws to describe systems that are fundamentally quantum in nature. Unfortunately, similar arguments do not hold for systems like watersheds that are heterogeneous at a wide range of scales. Ray Solomonoff formalized the situation in 1968 by showing that given infinite evidence, simultaneously minimizing model complexity and entropy in predictions always leads to the best possible model. The open question in hydrology is about what happens when we don't have infinite evidence - for example, when the future will not look like the past, or when one watershed does not behave like another. How do we isolate stationary and commutable components of watershed behavior? I propose that one possible answer to this dilemma lies in a formal combination of physics and statistics. In this talk I outline my recent analogue (Solomonoff's theorem was digital) of Solomonoff's idea that allows us to quantify the complexity/entropy tradeoff in a way that is intuitive to physical scientists. I show how to formally combine "physical" and statistical methods for model development in a way that allows us to derive the theoretically best possible model given any given physics approximation(s) and available observations. Finally, I apply an analogue of Solomonoff's theorem to evaluate the tradeoff between model complexity and prediction power.

Collective behaviours: from biochemical kinetics to electronic circuits.

PubMed

Agliari, Elena; Barra, Adriano; Burioni, Raffaella; Di Biasio, Aldo; Uguzzoni, Guido

2013-12-10

In this work we aim to highlight a close analogy between cooperative behaviors in chemical kinetics and cybernetics; this is realized by using a common language for their description, that is mean-field statistical mechanics. First, we perform a one-to-one mapping between paradigmatic behaviors in chemical kinetics (i.e., non-cooperative, cooperative, ultra-sensitive, anti-cooperative) and in mean-field statistical mechanics (i.e., paramagnetic, high and low temperature ferromagnetic, anti-ferromagnetic). Interestingly, the statistical mechanics approach allows a unified, broad theory for all scenarios and, in particular, Michaelis-Menten, Hill and Adair equations are consistently recovered. This framework is then tested against experimental biological data with an overall excellent agreement. One step forward, we consistently read the whole mapping from a cybernetic perspective, highlighting deep structural analogies between the above-mentioned kinetics and fundamental bricks in electronics (i.e. operational amplifiers, flashes, flip-flops), so to build a clear bridge linking biochemical kinetics and cybernetics.

Collective behaviours: from biochemical kinetics to electronic circuits

NASA Astrophysics Data System (ADS)

Agliari, Elena; Barra, Adriano; Burioni, Raffaella; di Biasio, Aldo; Uguzzoni, Guido

2013-12-01

In this work we aim to highlight a close analogy between cooperative behaviors in chemical kinetics and cybernetics; this is realized by using a common language for their description, that is mean-field statistical mechanics. First, we perform a one-to-one mapping between paradigmatic behaviors in chemical kinetics (i.e., non-cooperative, cooperative, ultra-sensitive, anti-cooperative) and in mean-field statistical mechanics (i.e., paramagnetic, high and low temperature ferromagnetic, anti-ferromagnetic). Interestingly, the statistical mechanics approach allows a unified, broad theory for all scenarios and, in particular, Michaelis-Menten, Hill and Adair equations are consistently recovered. This framework is then tested against experimental biological data with an overall excellent agreement. One step forward, we consistently read the whole mapping from a cybernetic perspective, highlighting deep structural analogies between the above-mentioned kinetics and fundamental bricks in electronics (i.e. operational amplifiers, flashes, flip-flops), so to build a clear bridge linking biochemical kinetics and cybernetics.

Mediation analysis in nursing research: a methodological review

PubMed Central

Liu, Jianghong; Ulrich, Connie

2017-01-01

Mediation statistical models help clarify the relationship between independent predictor variables and dependent outcomes of interest by assessing the impact of third variables. This type of statistical analysis is applicable for many clinical nursing research questions, yet its use within nursing remains low. Indeed, mediational analyses may help nurse researchers develop more effective and accurate prevention and treatment programs as well as help bridge the gap between scientific knowledge and clinical practice. In addition, this statistical approach allows nurse researchers to ask – and answer – more meaningful and nuanced questions that extend beyond merely determining whether an outcome occurs. Therefore, the goal of this paper is to provide a brief tutorial on the use of mediational analyses in clinical nursing research by briefly introducing the technique and, through selected empirical examples from the nursing literature, demonstrating its applicability in advancing nursing science. PMID:26176804

Associations among sella turcica bridging, atlas arcuate foramen (ponticulus posticus) development, atlas posterior arch deficiency, and the occurrence of palatally displaced canine impaction.

PubMed

Haji Ghadimi, Mona; Amini, Fariborz; Hamedi, Shayesteh; Rakhshan, Vahid

2017-03-01

Head and neck skeletal anomalies or normal variants might predict the occurrence of palatally displaced impacted maxillary canines. Despite their clinical importance, studies in this regard are rare, especially when it comes to vertebral anomalies. This case-control study was performed on cephalographs of 35 orthodontic patients (11 male, 24 female) with palatally displaced canines (PDC) and 75 patients without them (29 male, 46 female). PDC were diagnosed on panoramic and lateral cephalographs and from clinical reports. The occurrence and severity of sella turcica bridge and the atlas ponticulus posticus, and deficiency of the posterior atlas arch were evaluated twice on lateral cephalographs. The associations between the occurrence and level of these skeletal anomalies and variations of PDC occurrence as well as additional correlations were assessed using multivariable and bivariate statistics (α = 0.05; β ≤0.2). The patients' mean age was 18.4 ± 1.9 years. In the control and patient groups, 23 (30.7%) and 21 subjects (60%) had sella turcica bridging, respectively (chi-square, P = 0.003). Ponticulus posticus was observed in 14 (18.7%) controls and 15 (42.9%) patients (chi-square, P = 0.007). Posterior atlas arch deficiency was observed in 4 (5.3%) controls and 5 (14.3%) patients (chi-square, P = 0.111). The presence of ponticulus posticus and sella turcica bridging might be associated with increased odds of PDC occurrence for about odds ratios of 3.1 and 3.5 times, respectively (binary logistic regression). PDC is positively associated with the occurrence and severity of sella turcica bridging and ponticulus posticus. The association between PDC and posterior atlas arch deficiency was inconclusive. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Monitoring of air pollution levels related to Charilaos Trikoupis Bridge.

PubMed

Sarigiannis, D A; Handakas, E J; Kermenidou, M; Zarkadas, I; Gotti, A; Charisiadis, P; Makris, K; Manousakas, M; Eleftheriadis, K; Karakitsios, S P

2017-12-31

Charilaos Trikoupis bridge is the longest cable bridge in Europe that connects Western Greece with the rest of the country. In this study, six air pollution monitoring campaigns (including major regulated air pollutants) were carried out from 2013 to 2015 at both sides of the bridge, located in the urban areas of Rio and Antirrio respectively. Pollution data were statistically analyzed and air quality was characterized using US and European air quality indices. From the overall campaign, it was found that air pollution levels were below the respective regulatory thresholds, but once at the site of Antirrio (26.4 and 52.2μg/m 3 for PM 2.5 and ΡΜ 10 , respectively) during the 2nd winter period. Daily average PM 10 and PM 2.5 levels from two monitoring sites were well correlated to gaseous pollutant (CO, NO, NO 2 , NO x and SO 2 ) levels, meteorological parameters and factor scores from Positive Matrix Factorization during the 3-year period. Moreover, the elemental composition of PM 10 and PM 2.5 was used for source apportionment. That analysis revealed that major emission sources were sulfates, mineral dust, biomass burning, sea salt, traffic and shipping emissions for PM 10 and PM 2.5 , for both Rio and Antirrio. Seasonal variation indicates that sulfates, mineral dust and traffic emissions increased during the warm season of the year, while biomass burning become the dominant during the cold season. Overall, the contribution of the Charilaos Trikoupis bridge to the vicinity air pollution is very low. This is the result of the relatively low daily traffic volume (~10,000 vehicles per day), the respective traffic fleet composition (~81% of the traffic fleet are private vehicles) and the speed limit (80km/h) which does not favor traffic emissions. In addition, the strong and frequent winds further contribute to the rapid dispersion of the emitted pollutants. Copyright © 2017. Published by Elsevier B.V.

Statistical physics of hard combinatorial optimization: Vertex cover problem

NASA Astrophysics Data System (ADS)

Zhao, Jin-Hua; Zhou, Hai-Jun

2014-07-01

Typical-case computation complexity is a research topic at the boundary of computer science, applied mathematics, and statistical physics. In the last twenty years, the replica-symmetry-breaking mean field theory of spin glasses and the associated message-passing algorithms have greatly deepened our understanding of typical-case computation complexity. In this paper, we use the vertex cover problem, a basic nondeterministic-polynomial (NP)-complete combinatorial optimization problem of wide application, as an example to introduce the statistical physical methods and algorithms. We do not go into the technical details but emphasize mainly the intuitive physical meanings of the message-passing equations. A nonfamiliar reader shall be able to understand to a large extent the physics behind the mean field approaches and to adjust the mean field methods in solving other optimization problems.

Statistical issues in searches for new phenomena in High Energy Physics

NASA Astrophysics Data System (ADS)

Lyons, Louis; Wardle, Nicholas

2018-03-01

Many analyses of data in High Energy Physics are concerned with searches for New Physics. We review the statistical issues that arise in such searches, and then illustrate these using the specific example of the recent successful search for the Higgs boson, produced in collisions between high energy protons at CERN’s Large Hadron Collider.

'Bridging worlds': meeting the emotional needs of dying patients.

PubMed

Law, Rollanda

2009-12-01

This paper is a report of a study to develop a grounded theory to explain how district nurses meet the emotional needs of dying patients in the community. There has been a policy commitment internationally to improve community services and enable people with terminal illnesses to die in their own homes. This increasing trend towards home deaths in the United Kingdom (UK) makes more demand on district nurses to provide emotional support for dying patients. A 'classic' grounded theory study was conducted in the UK between 2002 and 2005. Unstructured observations and semi-structured interviews were conducted with a purposive sample of nine district nurses, nine patients and four family carers. A further theoretical sample of five books of authors' accounts of their dying experiences and three district nurses who were advanced practitioners were selected. Five categories were identified in the data: 'outside world', 'dying world', 'entering dying world', 'maintaining connections' and the core category 'bridging worlds'. The theory of 'bridging worlds' indicated that dying patients experienced 'dying world' and 'outside world'. District nurses met dying patients' emotional needs by acting as a bridge between their two worlds, encouraging them to maintain connections with the outside world so that they did not become isolated in their dying world. District nurses should ensure that they meet both the physical and emotional needs of dying patients. Nursing education and literature need to concentrate on raising awareness of nurses' role in providing emotional support.

Signatures of the impact of flare-ejected plasma on the photosphere of a sunspot light bridge

NASA Astrophysics Data System (ADS)

Felipe, T.; Collados, M.; Khomenko, E.; Rajaguru, S. P.; Franz, M.; Kuckein, C.; Asensio Ramos, A.

2017-12-01

Aims: We investigate the properties of a sunspot light bridge, focusing on the changes produced by the impact of a plasma blob ejected from a C-class flare. Methods: We observed a sunspot in active region NOAA 12544 using spectropolarimetric raster maps of the four Fe I lines around 15 655 Å with the GREGOR Infrared Spectrograph, narrow-band intensity images sampling the Fe I 6173 Å line with the GREGOR Fabry-Pérot Interferometer, and intensity broad-band images in G-band and Ca II H-band with the High-resolution Fast Imager. All these instruments are located at the GREGOR telescope at the Observatorio del Teide, Tenerife, Spain. The data cover the time before, during, and after the flare event. The analysis is complemented with Atmospheric Imaging Assembly and Helioseismic and Magnetic Imager data from the Solar Dynamics Observatory. The physical parameters of the atmosphere at differents heights were inferred using spectral-line inversion techniques. Results: We identify photospheric and chromospheric brightenings, heating events, and changes in the Stokes profiles associated with the flare eruption and the subsequent arrival of the plasma blob to the light bridge, after traveling along an active region loop. Conclusions: The measurements suggest that these phenomena are the result of reconnection events driven by the interaction of the plasma blob with the magnetic field topology of the light bridge. Movies attached to Figs. 1 and 3 are available at http://www.aanda.org

What is biological physics?

NASA Astrophysics Data System (ADS)

Moss, Frank

1997-11-01

The question arises in a number of contexts from the editorial policies of our journals to the decisions and priorities of agencies that financially support scientific research. What kinds of papers should Physical Review E and Physical Review Letters accept within this category? What constitutes success in choosing which projects to fund? Do biological physicists discover new physics, or new biology, or do they simply make their considerable instrumental and analytical talents available to the biologists(see for example, V.A. Parsegian, Physics Today), July 1997 p. 23 and a Counterpoint by R. H. Austin, ibid p. 27.? And are there bridges to medical science? Are there now some questions in biological and medical science that cannot be creditably addressed without contemporary physics? And what does it mean that the president has ventured that the next five decades will be the age of biology as opposed to the last (which he described as the age of physics)? These questions seem interesting (at least to those who call themselves biological physicists) and may be gaining significance in view of the fact that what we loosely describe as biological physics as a field seems to be growing.

The Cal-Bridge Program: Supporting Diverse Graduate Students in Astrophysics

NASA Astrophysics Data System (ADS)

Smecker-Hane, Tammy A.; Rudolph, Alexander L.; Abazajian, Kevork; Povich, Matthew S.

2018-06-01

The mission of the Cal-Bridge program is to increase the number of underrepresented minority and women students completing a bachelor’s degree and entering a PhD program in astronomy, physics, or closely-related fields. To do so, we have built a network of faculty at diverse higher education institutions, including University of California (UC) campuses, California State Universities (CSUs), and community colleges dedicated to this goal. Students selected for our program are known as Cal-Bridge Scholars, and we give them a wide variety of support: (1) financial scholarships in their junior/senior years at CSU and their first year of graduate school at a UC, (2) intensive mentoring by a pair of CSU and UC faculty members, (3) tutoring, (4) professional development workshops, (5) exposure to research opportunities at various universities, and (6) membership in a growing cohort of like-minded students. In this poster, we report on our work in designing an effective mentoring program and developing tools like our mentoring and graduate application handbooks, and we discuss our tutoring program and the professional development workshops we have designed, and we report on their effectiveness. Funding for this program is provided by NSF-SSTEM Grant #1356133.

Strain features and condition assessment of orthotropic steel deck cable-supported bridges subjected to vehicle loads by using dense FBG strain sensors

NASA Astrophysics Data System (ADS)

Wei, Shiyin; Zhang, Zhaohui; Li, Shunlong; Li, Hui

2017-10-01

Strain is a direct indicator of structural safety. Therefore, strain sensors have been used in most structural health monitoring systems for bridges. However, until now, the investigation of strain response has been insufficient. This paper conducts a comprehensive study of the strain features of the U ribs and transverse diaphragm on an orthotropic steel deck and proposes a statistical paradigm for crack detection based on the features of vehicle-induced strain response by using the densely distributed optic fibre Bragg grating (FBG) strain sensors. The local feature of strain under vehicle load is highlighted, which enables the use of measurement data to determine the vehicle loading event and to make a decision regarding the health status of a girder near the strain sensors via technical elimination of the load information. Time-frequency analysis shows that the strain contains three features: the long-term trend item, the short-term trend item, and the instantaneous vehicle-induced item (IVII). The IVII is the wheel-induced strain with a remarkable local feature, and the measured wheel-induced strain is only influenced by the vehicle near the FBG sensor, while other vehicles slightly farther away have no effect on the wheel-induced strain. This causes the local strain series, among the FBG strain sensors in the same transverse locations of different cross-sections, to present similarities in shape to some extent and presents a time delay in successive order along the driving direction. Therefore, the strain series induced by an identical vehicle can be easily tracked and compared by extracting the amplitude and calculating the mutual ratio to eliminate vehicle loading information, leaving the girder information alone. The statistical paradigm for crack detection is finally proposed, and the detection accuracy is then validated by using dense FBG strain sensors on a long-span suspension bridge in China.

Radiographic Appearance of Transforaminal Lumbar Interbody Fusion Performed With and Without Recombinant Human Morphogenetic Protein-2.

PubMed

Stensby, J Derek; Kaliney, Ryan W; Alford, Bennett; Shen, Francis H; Patrie, James T; Fox, Michael G

2016-03-01

The purpose of this study is to determine whether recombinant human morphogenetic protein-2 (rhBMP-2) alters the findings on routine radiographs performed after transforaminal lumbar interbody fusion (TLIF). A retrospective review of 256 TLIF procedures in 200 patients was performed over a 4-year period. The rhBMP-2 group included 204 TLIFs in 160 patients, and the control group included 52 TLIFs in 40 patients. Two musculoskeletal radiologists reviewed the postoperative radiographs for endplate resorption, resorption resolution, new bone formation, bridging bone, and allograft migration. Statistical analysis was performed using logistic regression. The median age was 53 years in the rhBMP-2 group and 54 years in the control group (p = 0.182). The groups were similar with regard to sex (p = 0.517), single or multilevel TLIF (p = 0.921), specific TLIF levels (p = 0.53), and median radiographic follow-up (373 vs 366 days; p = 0.34). Findings that were more common in the rhBMP-2 group than in the control group included endplate resorption (38% [78/204] vs 12% [6/52]; odds ratio [OR], 4.67; 95% CI, 1.99-12.54; p < 0.001), resorption resolution (59% [46/78] vs 0% [0/6]; OR, 8.09; 95% CI, 1.41 to ∞; p = 0.022), new bone formation (84% [171/204] vs 67% [35/52]; OR, 2.51; 95% CI, 1.24-4.99; p = 0.011), bridging bone (55% [112/204] vs 31% [16/52]; OR, 2.73; 95% CI, 1.43-5.34; p = 0.002), and allograft migration (17% [35/204] vs 2% [1/52]; OR, 6.30; 95% CI, 0.91-151.41; p = 0.065). A statistically significant higher frequency of endplate resorption, new bone formation, and bone bridging is present in TLIF augmented by rhBMP-2 compared with TLIF performed without rhBMP-2. Endplate resorption resolves without treatment in most cases after rhBMP-2 use.

Exploration of the Theoretical Physical Capacity of the John F. Kennedy International Airport Runway System

NASA Technical Reports Server (NTRS)

Neitzke, Kurt W.; Guerreiro, Nelson M.

2014-01-01

A design study was completed to explore the theoretical physical capacity (TPC) of the John F. Kennedy International Airport (KJFK) runway system for a northflow configuration assuming impedance-free (to throughput) air traffic control functionality. Individual runways were modeled using an agent-based, airspace simulation tool, the Airspace Concept Evaluation System (ACES), with all runways conducting both departures and arrivals on a first-come first-served (FCFS) scheduling basis. A realistic future flight schedule was expanded to 3.5 times the traffic level of a selected baseline day, September 26, 2006, to provide a steady overdemand state for KJFK runways. Rules constraining departure and arrival operations were defined to reflect physical limits beyond which safe operations could no longer be assumed. Safety buffers to account for all sources of operational variability were not included in the TPC estimate. Visual approaches were assumed for all arrivals to minimize inter-arrival spacing. Parallel runway operations were assumed to be independent based on lateral spacing distances. Resulting time intervals between successive airport operations were primarily constrained by same-runway and then by intersecting-runway spacing requirements. The resulting physical runway capacity approximates a theoretical limit that cannot be exceeded without modifying runway interaction assumptions. Comparison with current KJFK operational limits for a north-flow runway configuration indicates a substantial throughput gap of approximately 48%. This gap may be further analyzed to determine which part may be feasibly bridged through the deployment of advanced systems and procedures, and which part cannot, because it is either impossible or not cost-effective to control. Advanced systems for bridging the throughput gap may be conceptualized and simulated using this same experimental setup to estimate the level of gap closure achieved.

Allergic to people: building bridges in a ripped psychic-soma.

PubMed

Teitelbaum, Stefanie

2008-06-01

An exploration of the use mind/body metaphors in a woman whose physical, environmental and psychoneurotic trauma culminated in an irreversible colostomy. She lived in a world of concrete symbols, her primary process damaged such that she could not create generative symbols to process her trauma. She regressed to a state of infantile megalomania, recoiling from the external reality of subjective others. Her introjective disorder mirrored her digestive disorder as she could absorb neither good objects nor good nutrients. The analytic situation has been an auxiliary fecal container and we work to bridge her mind body split with mind/body metaphors. As she reclaims lost development mastery, she displays a symbolized sphincter. As her capacity to form symbols grows, she rages and mourns for the loss of her fantasized ideal parents and her ideal body.

Patella instability: building bridges across the ocean a historic review.

PubMed

Arendt, Elizabeth A; Dejour, David

2013-02-01

The diagnosis of and treatment for musculoskeletal disease and injuries have seen an explosion of new knowledge. More precise imaging, correlative injury anatomy, more focused physical examination features, among others, have led this upsurge of current insight. Crucial to this knowledge revolution is the expansion of international knowledge, which is aided by an adoption of a universal scientific language, electronic transfer of information, and personal communication of surgeons and scientists across national boundaries. One area where this is particularly evident is in our knowledge and treatment for patellofemoral disorders. This article will review the developments in the management of patellar dislocations by tracing their historical roots. This is not meant to be a comprehensive review, but rather to give current readers a "historical memory" upon which to judge and interpret our present-day bridge of knowledge. Level of evidence V.

Materials science. Materials that couple sensing, actuation, computation, and communication.

PubMed

McEvoy, M A; Correll, N

2015-03-20

Tightly integrating sensing, actuation, and computation into composites could enable a new generation of truly smart material systems that can change their appearance and shape autonomously. Applications for such materials include airfoils that change their aerodynamic profile, vehicles with camouflage abilities, bridges that detect and repair damage, or robotic skins and prosthetics with a realistic sense of touch. Although integrating sensors and actuators into composites is becoming increasingly common, the opportunities afforded by embedded computation have only been marginally explored. Here, the key challenge is the gap between the continuous physics of materials and the discrete mathematics of computation. Bridging this gap requires a fundamental understanding of the constituents of such robotic materials and the distributed algorithms and controls that make these structures smart. Copyright © 2015, American Association for the Advancement of Science.

"Bridging Old Relations": The (De)Construction of Ethnic Identity in the Educational Context of Bosnia and Herzegovina from the Teachers' Point of View

ERIC Educational Resources Information Center

Kovac, Velibor Bobo; Tveit, Anne Dorthe; Cameron, David Lansing; Jortveit, Maryann

2017-01-01

The present study focuses on an educational arrangement in Bosnia and Herzegovina (BiH) known as "two schools under one roof." The term refers to two different ethnic groups (Bosniaks and Croats) physically sharing the same school building, but maintaining separate administrations, teaching staff, and curricula. The purpose of the study…

Cancer and truth.

PubMed Central

Hanganu, E; Popa, G

1977-01-01

In this paper the authors discuss the continuing dilemma for doctors who have to tell a patient that he has cancer, particularly the moment when he should confirm a diagnosis that most patients have already sensed. For the writers it is most important that the doctor should be a bridge for the patient to return to his everyday world from the physical and spiritual isolation which his disease has created. PMID:874981

Characterization and Physics-Based Modeling of Electrochemical Memristors

DTIC Science & Technology

2015-11-16

conducting films that result from electrical or optical stress. Model parameters and electrical characteristics were obtained from and validated...x- ray scattering, Conductive Bridge Random Access Memory 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME...Calculated DOS for GeSe2 in valence band and (b) conduction band .................. 43  Figure 45. DFT band structure for crystalline GeSe2

Synthesis and characterization of a melt processable polyimide

NASA Technical Reports Server (NTRS)

Burks, H. D.; St.clair, T. L.

1982-01-01

A melt processable polyimide which contains sulfur and oxygen bridges between the aromatic rings (BDSDA/APB) was synthesized and characterized. Its physical, mechanical, thermal and flow properties were determined as was its resistance to some of the more commonly used solvents. The melt flow properties were measured for the temperature range 250 C - 350 C and under the conditions (stress/strain) encountered in commercial processes.

Statistical physics of human beings in games: Controlled experiments

NASA Astrophysics Data System (ADS)

Liang, Yuan; Huang, Ji-Ping

2014-07-01

It is important to know whether the laws or phenomena in statistical physics for natural systems with non-adaptive agents still hold for social human systems with adaptive agents, because this implies whether it is possible to study or understand social human systems by using statistical physics originating from natural systems. For this purpose, we review the role of human adaptability in four kinds of specific human behaviors, namely, normal behavior, herd behavior, contrarian behavior, and hedge behavior. The approach is based on controlled experiments in the framework of market-directed resource-allocation games. The role of the controlled experiments could be at least two-fold: adopting the real human decision-making process so that the system under consideration could reflect the performance of genuine human beings; making it possible to obtain macroscopic physical properties of a human system by tuning a particular factor of the system, thus directly revealing cause and effect. As a result, both computer simulations and theoretical analyses help to show a few counterparts of some laws or phenomena in statistical physics for social human systems: two-phase phenomena or phase transitions, entropy-related phenomena, and a non-equilibrium steady state. This review highlights the role of human adaptability in these counterparts, and makes it possible to study or understand some particular social human systems by means of statistical physics coming from natural systems.

GEOquery: a bridge between the Gene Expression Omnibus (GEO) and BioConductor.

PubMed

Davis, Sean; Meltzer, Paul S

2007-07-15

Microarray technology has become a standard molecular biology tool. Experimental data have been generated on a huge number of organisms, tissue types, treatment conditions and disease states. The Gene Expression Omnibus (Barrett et al., 2005), developed by the National Center for Bioinformatics (NCBI) at the National Institutes of Health is a repository of nearly 140,000 gene expression experiments. The BioConductor project (Gentleman et al., 2004) is an open-source and open-development software project built in the R statistical programming environment (R Development core Team, 2005) for the analysis and comprehension of genomic data. The tools contained in the BioConductor project represent many state-of-the-art methods for the analysis of microarray and genomics data. We have developed a software tool that allows access to the wealth of information within GEO directly from BioConductor, eliminating many the formatting and parsing problems that have made such analyses labor-intensive in the past. The software, called GEOquery, effectively establishes a bridge between GEO and BioConductor. Easy access to GEO data from BioConductor will likely lead to new analyses of GEO data using novel and rigorous statistical and bioinformatic tools. Facilitating analyses and meta-analyses of microarray data will increase the efficiency with which biologically important conclusions can be drawn from published genomic data. GEOquery is available as part of the BioConductor project.

Native American Participation among Bachelors in Physical Sciences and Engineering: Results from 2003-13 Data of the National Center for Education Statistics. Focus On

ERIC Educational Resources Information Center

Merner, Laura; Tyler, John

2017-01-01

Using the National Center of Education Statistics' Integrated Postsecondary Education Data System (IPEDS), this report analyzes data on Native American recipients of bachelor's degrees among 16 physical science and engineering fields. Overall, Native Americans are earning physical science and engineering bachelor's degrees at lower rates than the…

Joint inversion of marine seismic AVA and CSEM data using statistical rock-physics models and Markov random fields: Stochastic inversion of AVA and CSEM data

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

Chen, J.; Hoversten, G.M.

2011-09-15

Joint inversion of seismic AVA and CSEM data requires rock-physics relationships to link seismic attributes to electrical properties. Ideally, we can connect them through reservoir parameters (e.g., porosity and water saturation) by developing physical-based models, such as Gassmann’s equations and Archie’s law, using nearby borehole logs. This could be difficult in the exploration stage because information available is typically insufficient for choosing suitable rock-physics models and for subsequently obtaining reliable estimates of the associated parameters. The use of improper rock-physics models and the inaccuracy of the estimates of model parameters may cause misleading inversion results. Conversely, it is easy tomore » derive statistical relationships among seismic and electrical attributes and reservoir parameters from distant borehole logs. In this study, we develop a Bayesian model to jointly invert seismic AVA and CSEM data for reservoir parameter estimation using statistical rock-physics models; the spatial dependence of geophysical and reservoir parameters are carried out by lithotypes through Markov random fields. We apply the developed model to a synthetic case, which simulates a CO{sub 2} monitoring application. We derive statistical rock-physics relations from borehole logs at one location and estimate seismic P- and S-wave velocity ratio, acoustic impedance, density, electrical resistivity, lithotypes, porosity, and water saturation at three different locations by conditioning to seismic AVA and CSEM data. Comparison of the inversion results with their corresponding true values shows that the correlation-based statistical rock-physics models provide significant information for improving the joint inversion results.« less

Forecasting runout of rock and debris avalanches

USGS Publications Warehouse

Iverson, Richard M.; Evans, S.G.; Mugnozza, G.S.; Strom, A.; Hermanns, R.L.

2006-01-01

Physically based mathematical models and statistically based empirical equations each may provide useful means of forecasting runout of rock and debris avalanches. This paper compares the foundations, strengths, and limitations of a physically based model and a statistically based forecasting method, both of which were developed to predict runout across three-dimensional topography. The chief advantage of the physically based model results from its ties to physical conservation laws and well-tested axioms of soil and rock mechanics, such as the Coulomb friction rule and effective-stress principle. The output of this model provides detailed information about the dynamics of avalanche runout, at the expense of high demands for accurate input data, numerical computation, and experimental testing. In comparison, the statistical method requires relatively modest computation and no input data except identification of prospective avalanche source areas and a range of postulated avalanche volumes. Like the physically based model, the statistical method yields maps of predicted runout, but it provides no information on runout dynamics. Although the two methods differ significantly in their structure and objectives, insights gained from one method can aid refinement of the other.

Engaging Axiology: Enabling MeaningfulTransdisciplinary Collaboration in Adapted Physical Activity.

PubMed

Peers, Danielle

2018-07-01

In this article, I explore the concept of axiology in the context of adapted physical activity research and analyze its connection to the more commonly discussed paradigmatic assumptions of epistemology and ontology. Following methodological scholars, I argue for an acknowledgment of the pivotal role that axiology already plays in adapted physical activity research and for the potential interdisciplinary and transdisciplinary opportunities that could be enabled by engaging with axiology in more explicit ways. I discuss a number of potential axiological gaps between the field of adapted physical activity and disability communities, arguing that such differences may undermine attempts at doing meaningful transdisciplinary research with such communities. I offer strategies for bridging these axiological gaps, encouraging us to work together in axiologically reflexive ways in order to increase meaningful opportunities for more people with disabilities to be engaged in the movement-based activities and communities of their choice.

The influence of marianismo beliefs on physical activity of immigrant Latinas

PubMed Central

D'Alonzo, Karen T.

2011-01-01

Purpose To verify and explicate the impact of marianismo beliefs on the physical activity behaviors of immigrant Latinas. Design/Method Twenty–eight immigrant Latinas, ages 18–40 years, were recruited to participate in two focus group interviews. Data collection and analysis were driven by Spradley’s Developmental Research Sequence (DRS) Results Two domain terms were identified: “Life is too fast here” and “The woman is the center of the family”. Six included terms and five cultural themes were specified. Discussion/Conclusions A combination of marianismo beliefs, acculturation stress, loss of social support and conflicts between collectivist and individualist values combine to adversely influence physical activity behaviors of immigrant Latinas. Implications for Practice Physical activity interventions for Hispanic women should capitalize on the strengths of the marianista, address factors leading to acculturation stress among women and their families and the establishment of bridges of social support among new groups of immigrants. PMID:22294337

Sparking Women's Interest in Physics through Science Education

NASA Astrophysics Data System (ADS)

Merali, Aliya; Wissel, S. A.; Ortiz, M.; Morgan, J. T.; Zwicker, A.

2011-10-01

As of 2010, less than 10% of the members of the APS division of plasma physics are female. Data from a 2005 AIP publication indicate that a lack of female presence in physics exists as early as high school and is perpetuated throughout the educational careers of women. Of the undergraduate programs run by PPPL, 16% of participants are female, and only 11% of participants that continue on to graduate school are female. In an effort to increase the exposure of young women to physics, we have expanded existing programs and initiated new programs such as a mentorship program and an energy focused essay contest. The goal of these programs is to bridge the gap between young and established women in science in order to increase young women's interest in the field of physics and thus increase the likelihood that they will continue on to study higher-level physics. Using data collected from participant surveys we have assessed the short-term effectiveness of PPPL programs in influencing young women to pursue careers in science and plasma physics. Ivie and Ray. AIP Publication Number R-430.02 (February 2005)

A new universality class in corpus of texts; A statistical physics study

NASA Astrophysics Data System (ADS)

Najafi, Elham; Darooneh, Amir H.

2018-05-01

Text can be regarded as a complex system. There are some methods in statistical physics which can be used to study this system. In this work, by means of statistical physics methods, we reveal new universal behaviors of texts associating with the fractality values of words in a text. The fractality measure indicates the importance of words in a text by considering distribution pattern of words throughout the text. We observed a power law relation between fractality of text and vocabulary size for texts and corpora. We also observed this behavior in studying biological data.

A statistical physics perspective on criticality in financial markets

NASA Astrophysics Data System (ADS)

Bury, Thomas

2013-11-01

Stock markets are complex systems exhibiting collective phenomena and particular features such as synchronization, fluctuations distributed as power-laws, non-random structures and similarity to neural networks. Such specific properties suggest that markets operate at a very special point. Financial markets are believed to be critical by analogy to physical systems, but little statistically founded evidence has been given. Through a data-based methodology and comparison to simulations inspired by the statistical physics of complex systems, we show that the Dow Jones and index sets are not rigorously critical. However, financial systems are closer to criticality in the crash neighborhood.

Some past and present challenges of econophysics

NASA Astrophysics Data System (ADS)

Mantegna, R. N.

2016-12-01

We discuss the cultural background that was shared by some of the first econophysicists when they started to work on economic and financial problems with methods and tools of statistical physics. In particular we discuss about the role of stylized facts and statistical physical laws in economics and statistical physics respectively. As an example of the problems and potentials associated with the interaction of different communities of scholars dealing with problems observed in economic and financial systems we briefly discuss the development and the perspectives of the use of tools and concepts of networks in econophysics, economics and finance.

Statistical physics inspired energy-efficient coded-modulation for optical communications.

PubMed

Djordjevic, Ivan B; Xu, Lei; Wang, Ting

2012-04-15

Because Shannon's entropy can be obtained by Stirling's approximation of thermodynamics entropy, the statistical physics energy minimization methods are directly applicable to the signal constellation design. We demonstrate that statistical physics inspired energy-efficient (EE) signal constellation designs, in combination with large-girth low-density parity-check (LDPC) codes, significantly outperform conventional LDPC-coded polarization-division multiplexed quadrature amplitude modulation schemes. We also describe an EE signal constellation design algorithm. Finally, we propose the discrete-time implementation of D-dimensional transceiver and corresponding EE polarization-division multiplexed system. © 2012 Optical Society of America

Theory of atomic spectral emission intensity

NASA Astrophysics Data System (ADS)

Yngström, Sten

1994-07-01

The theoretical derivation of a new spectral line intensity formula for atomic radiative emission is presented. The theory is based on first principles of quantum physics, electrodynamics, and statistical physics. Quantum rules lead to revision of the conventional principle of local thermal equilibrium of matter and radiation. Study of electrodynamics suggests absence of spectral emission from fractions of the numbers of atoms and ions in a plasma due to radiative inhibition caused by electromagnetic force fields. Statistical probability methods are extended by the statement: A macroscopic physical system develops in the most probable of all conceivable ways consistent with the constraining conditions for the system. The crucial role of statistical physics in transforming quantum logic into common sense logic is stressed. The theory is strongly supported by experimental evidence.

A macro-physics model of depreciation rate in economic exchange

NASA Astrophysics Data System (ADS)

Marmont Lobo, Rui F.; de Sousa, Miguel Rocha

2014-02-01

This article aims at a new approach for a known fundamental result: barter or trade increases economic value. It successfully bridges the gap between the theory of value and the exchange process attached to the transition from endowments to the equilibrium in the core and contract curve. First, we summarise the theory of value; in Section 2, we present the Edgeworth (1881) box and an axiomatic approach and in Section 3, we apply our pure exchange model. Finally (in Section 4), using our open econo-physics pure barter (EPB) model, we derive an improvement in value, which means that pure barter leads to a decline in depreciation rate.

Basic ideas and concepts in hot wire anemometry: an experimental approach for introductory physics students

NASA Astrophysics Data System (ADS)

El Abed, Mohamed

2016-01-01

The purpose of hot wire anemometry is to measure the speed of an air stream. The classical method is based on the measure of the value of a temperature dependant resistor inserted in a Wheatstone bridge (Lomas 1986 Fundamentals of Hot Wire Anemometry (Cambridge: Cambridge University Press)). In this paper we exhibit the physics behind this method and show that by using a wire whose resistance does not vary on the field of temperature explored (from 20 °C to 200 °C), it is however possible to make accurate measurements. Finally, limitations of the method are discussed.

Autotrophs' challenge to Dynamic Energy Budget theory: Comment on ;Physics of metabolic organization; by Marko Jusup et al.

NASA Astrophysics Data System (ADS)

Geček, Sunčana

2017-03-01

Jusup and colleagues in the recent review on physics of metabolic organization [1] discuss in detail motivational considerations and common assumptions of Dynamic Energy Budget (DEB) theory, supply readers with a practical guide to DEB-based modeling, demonstrate the construction and dynamics of the standard DEB model, and illustrate several applications. The authors make a step forward from the existing literature by seamlessly bridging over the dichotomy between (i) thermodynamic foundations of the theory (which are often more accessible and understandable to physicists and mathematicians), and (ii) the resulting bioenergetic models (mostly used by biologists in real-world applications).

Making Inferences: Comprehension of Physical Causality, Intentionality, and Emotions in Discourse by High-Functioning Older Children, Adolescents, and Adults with Autism.

PubMed

Bodner, Kimberly E; Engelhardt, Christopher R; Minshew, Nancy J; Williams, Diane L

2015-09-01

Studies investigating inferential reasoning in autism spectrum disorder (ASD) have focused on the ability to make socially-related inferences or inferences more generally. Important variables for intervention planning such as whether inferences depend on physical experiences or the nature of social information have received less consideration. A measure of bridging inferences of physical causation, mental states, and emotional states was administered to older children, adolescents, and adults with and without ASD. The ASD group had more difficulty making inferences, particularly related to emotional understanding. Results suggest that individuals with ASD may not have the stored experiential knowledge that specific inferences depend upon or have difficulties accessing relevant experiences due to linguistic limitations. Further research is needed to tease these elements apart.

On the Onset of Thermocapillary Convection in a Liquid bridge

NASA Astrophysics Data System (ADS)

Shukla, Kedar

Thermo capillary convection refers to motion driven by the application of a temperature gradient along the interface. The temperature gradient may be large enough to cause oscillations in the basic state of the fluid. The vast majority of the liquid bridge investigations performed aboard on the sounding rockets or the space shuttles [1, 2] focused on the float zone processes because the process has been regarded as a candidate for the space based manufacturing of semiconductor materials. Although the buoyancy effect is avoided in the floating zone techniques during space operation, it experiences surface tension driven convection initiated by the temperature gradient along the free surface of the zone [3]. The appearance of the oscillatory thermo capillary convection couples with the solidification processes leads to the striations and results into the degradation of the crystals [4, 5]. The half zone consists of the liquid bridge held between two solid, planar end walls across which a temperature gradient is applied. Thus the basic state of thermo capillary convection consists of a single toroidal roll with the surface motion directed downwards from the hot upper disc to the cold lower one. Bennacer et al [6] studied how different axial profiles of the heat flux affect the flow patterns and transition from ax symmetric steady to ax symmetric oscillatory flow. The three dimensional instability of liquid bridges located between isothermal differentially heated disks were studied by several authors [7-14]. The interface deformation caused by the gravity jitters depends on the volume of the liquid bridge and cause changes in the physical properties of the liquid, which ultimately influence the basic state of the fluid [15-16]. The paper discusses Marangoni convection in a liquid bridge subject to g-jitters in a micro gravity environment. The parametric excitement of the liquid bridge with surface tension variation along with the free surface is considered. We will follow the method of Shukla [17] for Boussinesq flow to model the convective instability in an axisymmetric flow in the liquid bridge. The surface deformation caused by g-jitters and its effects on the onset of oscillatory flow will be examined. References: [1] Grodzka, P.G. and Bannister, T.C., Heat flow and convection demonstration experiments abord Appolo 14, Science (Washington, D.C.), Vol.176, May 1972, pp. 506-508. [2] Bannister, T C., etal, NASA, TMX-64772, 1973. [3] Shukla, K.N. Hydrodynamics of Diffusive Processes, Applied Mechanics Review, Vol.54, No.5, 2001, pp. 391-404. [4] Chen, G., Lizee, A., Roux, B.,, Bifurcation analysis of the thermo capillary convection in cylindrical liquid bridge, J Crystal growth, Vol. 180, 1997, pp.638-647. [5] Imaishi, N., Yasuhiro, S., Akiyama, Y and Yoda, S., Numerical simulation of oscillatory Marangoni flow in half zone liquid bridge of low Prandtl number fluid, J., Crystal Growth, Vol. 230, 2001, pp. 164-171. [6] Bennacer, R., Mohamad, A.A., Leonardi, E., The effect o heat flux distribution on thermo capillary convection in a sideheated liquid bridge, Numer. Heat transfer, Part A, vol. 41, 2002, pp. 657-671. [7] Kuhlmann, H C., Rath, H J., Hydrodynamic instabilities in Cylindrical thermocapillary liquid bridges, J Fluid Mech., Vol. 247,1993, pp. 247-274. [8] Wanshura, M., Shevtsova, V M, Kuhlmann, H C and Rath, H J., Convective instability in thermocapillary liquid bridges, Phys. Fluids, Vol. 7, 1995, pp. 912-925. [9] Kasperski, G., Batoul, A., Labrosse, G., Up to the unsteadiness of axisymmetric thermocapillary low in a laterally heated liquid bridge, Phys. Fluids, Vol. 12, 2000, pp. 103-119. [10] Lappa, M., Savino, R., Monti, R., Three dimensional numerical simulation of Marangoni instabilities in non cylindrical liquid bridges in microgravity, Int. J Heat Mass Transfer, Vol. 44, 2001, pp. 1983-2003 [11] Zeng, Z, Mizuseki, H., Simamura, K., Fukud, T. Higashino, K, Kawaazoe, Y., Three dimensional oscillatory thermocapillary convection in liquid bridgeunder microgravity, Int. J heat Mass Transf., Vol. 44, 2001, pp. 3765-3774. [12] Kamotani, Y., Wang, L, Hatta, S., Wang, A., Yoda, S., Free surface heat loss effect on Oscillatory thermocapillary flow in a liquid bridges of high Prandtl number fluids, Int. J heat Mass Transfer, Vol. 46, 2003, pp. 3211-3220.

Improved VAS regression soundings of mesoscale temperature structure observed during the 1982 atmospheric variability experiment

NASA Technical Reports Server (NTRS)

Chesters, Dennis; Keyser, Dennis A.; Larko, David E.; Uccellini, Louis W.

1987-01-01

An Atmospheric Variability Experiment (AVE) was conducted over the central U.S. in the spring of 1982, collecting radiosonde date to verify mesoscale soundings from the VISSR Atmospheric Sounder (VAS) on the GOES satellite. Previously published VAS/AVE comparisons for the 6 March 1982 case found that the satellite retrievals scarcely detected a low level temperature inversion or a mid-tropospheric cold pool over a special mesoscale radiosonde verification network in north central Texas. The previously published regression and physical retrieval algorithms did not fully utilize VAS' sensitivity to important subsynoptic thermal features. Therefore, the 6 March 1982 case was reprocessed adding two enhancements to the VAS regression retrieval algorithm: (1) the regression matrix was determined using AVE profile data obtained in the region at asynoptic times, and (2) more optimistic signal-to-noise statistical conditioning factors were applied to the VAS temperature sounding channels. The new VAS soundings resolve more of the low level temperature inversion and mid-level cold pool. Most of the improvements stems from the utilization of asynoptic radiosonde observations at NWS sites. This case suggests that VAS regression soundings may require a ground-based asynoptic profiler network to bridge the gap between the synoptic radiosonde network and the high resolution geosynchronous satellite observations during the day.

Role-separating ordering in social dilemmas controlled by topological frustration

NASA Astrophysics Data System (ADS)

Amaral, Marco A.; Perc, Matjaž; Wardil, Lucas; Szolnoki, Attila; da Silva Júnior, Elton J.; da Silva, Jafferson K. L.

2017-03-01

``Three is a crowd" is an old proverb that applies as much to social interactions as it does to frustrated configurations in statistical physics models. Accordingly, social relations within a triangle deserve special attention. With this motivation, we explore the impact of topological frustration on the evolutionary dynamics of the snowdrift game on a triangular lattice. This topology provides an irreconcilable frustration, which prevents anticoordination of competing strategies that would be needed for an optimal outcome of the game. By using different strategy updating protocols, we observe complex spatial patterns in dependence on payoff values that are reminiscent to a honeycomb-like organization, which helps to minimize the negative consequence of the topological frustration. We relate the emergence of these patterns to the microscopic dynamics of the evolutionary process, both by means of mean-field approximations and Monte Carlo simulations. For comparison, we also consider the same evolutionary dynamics on the square lattice, where of course the topological frustration is absent. However, with the deletion of diagonal links of the triangular lattice, we can gradually bridge the gap to the square lattice. Interestingly, in this case the level of cooperation in the system is a direct indicator of the level of topological frustration, thus providing a method to determine frustration levels in an arbitrary interaction network.

Astronomy4Kids: Extending STEM learning to the youngest student through an online educational outreach program

NASA Astrophysics Data System (ADS)

Pearson, Richard L.; Pearson, Sarah R.

2017-06-01

Astronomy4Kids is an online video series aimed at filling the void of effective and engaging education tools within early childhood learning. Much discussion and research has been conducted on the significance of early learning, with general trends showing significant benefits to early introductions to language, mathematics, and general science concepts. Ultimately, when ideas are introduced to a child at a young age, that child is better prepared for when the concept is re-introduced in its entirety later. National agencies—such as the AAS and NSF—have implemented Science, Technology, Engineering, and Math (STEM) initiatives to expand learning in these areas. However, despite these many resources, the education outreach available to the youngest learners (under the age of 8 or those from pre-school to about 2nd-grade) is seriously lacking. Astronomy4Kids was created to bridge this gap and provide succinct, creative-learning videos following the principles of Fred Rogers, the founder of preschool education video. We present ways to incorporate the freely accessible YouTube videos within various classroom ages and discuss how to use simple activities to promote physics, astronomy, and math learning. Current development, video statistics, and future work will be discussed. The freely accessible videos can be found at www.astronomy4kids.net.