Community-Based Field Experiences in Teacher Education: Possibilities for a Pedagogical Third Space

ERIC Educational Resources Information Center

Hallman, Heidi L.

2012-01-01

The present article discusses the importance of community-based field experiences as a feature of teacher education programs. Through a qualitative case study, prospective teachers' work with homeless youth in an after-school initiative is presented. Framing community-based field experiences in teacher education through "third space" theory, the…

Concerns of Teacher Candidates in an Early Field Experience

ERIC Educational Resources Information Center

Chang, Sau Hou

2009-01-01

The present study examined the concerns of teacher candidates in an early field experience. Thirty-five teacher candidates completed the Teacher Concerns Checklist (TCC, Fuller & Borich, 2000) at the beginning, middle and end of their early field experiences. Results showed that teacher candidates ranked impact as the highest concern, self as…

The Effects of Hypergravic Fields on Neural Signalling in the Hippocampus

NASA Technical Reports Server (NTRS)

Horowitz, John; Horwitz, Barbara

1991-01-01

The goal of this grant is to study the effect of hypergravic fields on the modulation of hippocampal electrical activity by serotonin (5-HT). The proposed study represents a shift from our previous NASA grants covering three diverse areas in neurobiology (thermoregulation, vestibular and auditory brainstem evoked responses, and the hippocampus) to consideration of only one of these areas, the hippocampus. To place our proposed hippocampal experiments in context with relevant Spacelab-3 experiments and hypergravic experiments, two experiments on receptor changes in animals exposed to altered gravitational fields are first described. Our experiments build on these structural/biochemical observations and extend investigations to related electrical activity at 1 G and in hypergravic fields. The background continues with a review of past studies at 1G related to effects of serotonin on hippocampal electrical activity (i.e., population spikes, intracellular potentials).

Determination of Biology Department Students' Past Field Trip Experiences and Examination of Their Self-Efficacy Beliefs in Planning and Organising Educational Field Trips

ERIC Educational Resources Information Center

Bozdogan, Aykut Emre

2015-01-01

The purpose of this study is to determine the past field trip experiences of pre-service teachers who are graduates of Faculty of Sciences, Department of Biology and who had pedagogical formation training certificate and to examine their self-efficacy beliefs in planning and organizing field trips with regard to different variables. The study was…

The Effects of Primary Sources and Field Trip Experience on the Knowledge Retention of Multicultural Content

ERIC Educational Resources Information Center

Farmer, James; Knapp, Doug; Benton, Gregory M.

2007-01-01

Although small in scope, this study attempted to analyze the impacts of primary sources and field trip experiences on multicultural education through first-hand narrative interviews, one year after the experience. In particular, it assessed the recollections of students who participated in a one-half-day field trip to George Washington Carver…

NASA Cold Land Processes Experiment (CLPX 2002/03): Field measurements of snowpack properties and soil moisture

Treesearch

Kelly Elder; Don Cline; Glen E. Liston; Richard Armstrong

2009-01-01

A field measurement program was undertaken as part NASA's Cold Land Processes Experiment (CLPX). Extensive snowpack and soil measurements were taken at field sites in Colorado over four study periods during the two study years (2002 and 2003). Measurements included snow depth, density, temperature, grain type and size, surface wetness, surface roughness, and...

Maximizing research study effectiveness in malaria elimination settings: a mixed methods study to capture the experiences of field-based staff.

PubMed

Canavati, Sara E; Quintero, Cesia E; Haller, Britt; Lek, Dysoley; Yok, Sovann; Richards, Jack S; Whittaker, Maxine Anne

2017-09-11

In a drug-resistant, malaria elimination setting like Western Cambodia, field research is essential for the development of novel anti-malarial regimens and the public health solutions necessary to monitor the spread of resistance and eliminate infection. Such field studies often face a variety of similar implementation challenges, but these are rarely captured in a systematic way or used to optimize future study designs that might overcome similar challenges. Field-based research staff often have extensive experience and can provide valuable insight regarding these issues, but their perspectives and experiences are rarely documented and seldom integrated into future research protocols. This mixed-methods analysis sought to gain an understanding of the daily challenges encountered by research field staff in the artemisinin-resistant, malaria elimination setting of Western Cambodia. In doing so, this study seeks to understand how the experiences and opinions of field staff can be captured, and used to inform future study designs. Twenty-two reports from six field-based malaria studies conducted in Western Cambodia were reviewed using content analysis to identify challenges to conducting the research. Informal Interviews, Focus Group Discussions and In-depth Interviews were also conducted among field research staff. Thematic analysis of the data was undertaken using Nvivo 9 ® software. Triangulation and critical case analysis was also used. There was a lack of formalized avenues through which field workers could report challenges experienced when conducting the malaria studies. Field research staff faced significant logistical barriers to participant recruitment and data collection, including a lack of available transportation to cover long distances, and the fact that mobile and migrant populations (MMPs) are usually excluded from studies because of challenges in follow-up. Cultural barriers to communication also hindered participant recruitment and created unexpected delays. Field staff often paid a physical, emotional and financial cost, going beyond their duty in order to keep the study running. Formal monthly reports filled out by field study staff could be a key tool for capturing field study staff experiences effectively, but require specific report fields to encourage staff to outline their challenges and to propose potential solutions. Forging strong bonds with communities and their leaders may improve communication, and decrease barriers to participant recruitment. Study designs that make it feasible for MMPs to participate should be pursued; in addition to increasing the potential participant pool, this will ensure that the most malaria-endemic demographic is taken into account in research studies. Overlaps between clinical care and research create ethical dilemmas for study staff, a fact that warrants careful consideration. Lessons learned from study field staff should be used to create a set of locally-relevant recommendations to inform future study designs.

Drift studies--comparison of field and wind tunnel experiments.

PubMed

Stadler, R; Regenauer, W

2005-01-01

Drift at pesticide application leads to a pollution of non-target crops, non-target species and surface water. Spray drift is influenced by many factors like environmental conditions, vegetation, technical conditions, and physical properties of the tank mixes and influenced by Chemicals. Field experiments to characterise spray drift effects with the risk of permanent changing weather conditions can be supported by wind tunnel experiments. Wind tunnel experiments do not lead to the same soil deposition curves like field experiments, but the ratio of drift reduction potential is comparable.

Building Collaborative Research Opportunities into Study Abroad Programs: A Case Study from Panama

ERIC Educational Resources Information Center

Solís, Patricia; Price, Marie; Adames de Newbill, María

2015-01-01

As universities increase their international study opportunities, enormous potential exists to create geography field courses that provide undergraduates and graduate students with primary research experience and intercultural collaboration. This paper draws from our experience leading a two-week collaborative field course in Panama. We outline…

Quantifying differences in responses of aquatic insects to trace metal exposure in field studies and short-term stream mesocosm experiments

USGS Publications Warehouse

Iwasaki, Yuichi; Schmidt, Travis S.; Clements, William H.

2018-01-01

Characterizing macroinvertebrate taxa as either sensitive or tolerant is of critical importance for investigating impacts of anthropogenic stressors in aquatic ecosystems and for inferring causality. However, our understanding of relative sensitivity of aquatic insects to metals in the field and under controlled conditions in the laboratory or mesocosm experiments is limited. In this study, we compared the response of 16 lotic macroinvertebrate families to metals in short-term (10-day) stream mesocosm experiments and in a spatially extensive field study of 154 Colorado streams. Comparisons of field and mesocosm-derived EC20 (effect concentration of 20%) values showed that aquatic insects were generally more sensitive to metals in the field. Although the ranked sensitivity to metals was similar for many families, we observed large differences between field and mesocosm responses for some groups (e.g., Baetidae and Heptageniidae). These differences most likely resulted from the inability of short-term experiments to account for factors such as dietary exposure to metals, rapid recolonization in the field, and effects of metals on sensitive life stages. Understanding mechanisms responsible for differences among field, mesocosm, and laboratory approaches would improve our ability to predict contaminant effects and establish ecologically meaningful water-quality criteria.

Assessment of Habitat Suitability Is Affected by Plant-Soil Feedback: Comparison of Field and Garden Experiment.

PubMed

Hemrová, Lucie; Knappová, Jana; Münzbergová, Zuzana

2016-01-01

Field translocation experiments (i.e., the introduction of seeds or seedlings of different species into different localities) are commonly used to study habitat associations of species, as well as factors limiting species distributions and local abundances. Species planted or sown in sites where they naturally occur are expected to perform better or equally well compared to sites at which they do not occur or are rare. This, however, contrasts with the predictions of the Janzen-Connell hypothesis and commonly reported intraspecific negative plant-soil feedback. The few previous studies indicating poorer performance of plants at sites where they naturally occur did not explore the mechanisms behind this pattern. In this study, we used field translocation experiments established using both seeds and seedlings to study the determinants of local abundance of four dominant species in grasslands. To explore the possible effects of intraspecific negative plant-soil feedback on our results, we tested the effect of local species abundance on the performance of the plants in the field experiment. In addition, we set up a garden experiment to explore the intensity of intraspecific as well as interspecific feedback between the dominants used in the experiment. In some cases, the distribution and local abundances of the species were partly driven by habitat conditions at the sites, and species performed better at their own sites. However, the prevailing pattern was that the local dominants performed worse at sites where they naturally occur than at any other sites. Moreover, the success of plants in the field experiment was lower in the case of higher intraspecific abundance prior to experimental setup. In the garden feedback experiment, two of the species performed significantly worse in soils conditioned by their species than in soils conditioned by the other species. In addition, the performance of the plants was significantly correlated between the two experiments, suggesting that plant-soil feedback is a likely explanation of the patterns observed in the field. All of the results indicate that intraspecific negative plant-soil feedback, either biotic or abiotic, may be a key factor determining the performance of the plants in our field translocation experiment. The possible effects of negative feedback should thus be considered when evaluating results of translocation experiments in future studies.

Assessment of Habitat Suitability Is Affected by Plant-Soil Feedback: Comparison of Field and Garden Experiment

PubMed Central

Hemrová, Lucie; Knappová, Jana; Münzbergová, Zuzana

2016-01-01

Background Field translocation experiments (i.e., the introduction of seeds or seedlings of different species into different localities) are commonly used to study habitat associations of species, as well as factors limiting species distributions and local abundances. Species planted or sown in sites where they naturally occur are expected to perform better or equally well compared to sites at which they do not occur or are rare. This, however, contrasts with the predictions of the Janzen-Connell hypothesis and commonly reported intraspecific negative plant-soil feedback. The few previous studies indicating poorer performance of plants at sites where they naturally occur did not explore the mechanisms behind this pattern. Aims and Methods In this study, we used field translocation experiments established using both seeds and seedlings to study the determinants of local abundance of four dominant species in grasslands. To explore the possible effects of intraspecific negative plant-soil feedback on our results, we tested the effect of local species abundance on the performance of the plants in the field experiment. In addition, we set up a garden experiment to explore the intensity of intraspecific as well as interspecific feedback between the dominants used in the experiment. Key Results In some cases, the distribution and local abundances of the species were partly driven by habitat conditions at the sites, and species performed better at their own sites. However, the prevailing pattern was that the local dominants performed worse at sites where they naturally occur than at any other sites. Moreover, the success of plants in the field experiment was lower in the case of higher intraspecific abundance prior to experimental setup. In the garden feedback experiment, two of the species performed significantly worse in soils conditioned by their species than in soils conditioned by the other species. In addition, the performance of the plants was significantly correlated between the two experiments, suggesting that plant-soil feedback is a likely explanation of the patterns observed in the field. Conclusions All of the results indicate that intraspecific negative plant-soil feedback, either biotic or abiotic, may be a key factor determining the performance of the plants in our field translocation experiment. The possible effects of negative feedback should thus be considered when evaluating results of translocation experiments in future studies. PMID:27336400

Electron-ion hybrid instability experiment upgrades to the Auburn Linear Experiment for Instability Studies.

PubMed

DuBois, A M; Arnold, I; Thomas, E; Tejero, E; Amatucci, W E

2013-04-01

The Auburn Linear EXperiment for Instability Studies (ALEXIS) is a laboratory plasma physics experiment used to study spatially inhomogeneous flows in a magnetized cylindrical plasma column that are driven by crossed electric (E) and magnetic (B) fields. ALEXIS was recently upgraded to include a small, secondary plasma source for a new dual source, interpenetrating plasma experiment. Using two plasma sources allows for highly localized electric fields to be made at the boundary of the two plasmas, inducing strong E × B velocity shear in the plasma, which can give rise to a regime of instabilities that have not previously been studied in ALEXIS. The dual plasma configuration makes it possible to have independent control over the velocity shear and the density gradient. This paper discusses the recent addition of the secondary plasma source to ALEXIS, as well as the plasma diagnostics used to measure electric fields and electron densities.

Women's decision to major in STEM fields

NASA Astrophysics Data System (ADS)

Conklin, Stephanie

This paper explores the lived experiences of high school female students who choose to enter into STEM fields, and describes the influencing factors which steered these women towards majors in computer science, engineering and biology. Utilizing phenomenological methodology, this study seeks to understand the essence of women's decisions to enter into STEM fields and further describe how the decision-making process varies for women in high female enrollment fields, like biology, as compared with low enrollment fields like, computer science and engineering. Using Bloom's 3-Stage Theory, this study analyzes how relationships, experiences and barriers influenced women towards, and possibly away, from STEM fields. An analysis of women's experiences highlight that support of family, sustained experience in a STEM program during high school as well as the presence of an influential teacher were all salient factors in steering women towards STEM fields. Participants explained that influential teacher worked individually with them, modified and extended assignments and also steered participants towards coursework and experiences. This study also identifies factors, like guidance counselors as well as personal challenges, which inhibited participant's path to STEM fields. Further, through analyzing all six participants' experiences, it is clear that a linear model, like Bloom's 3-Stage Model, with limited ability to include potential barriers inhibited the ability to capture the essence of each participant's decision-making process. Therefore, a revised model with no linear progression which allows for emerging factors, like personal challenges, has been proposed; this model focuses on how interest in STEM fields begins to develop and is honed and then mastered. This study also sought to identify key differences in the paths of female students pursuing different majors. The findings of this study suggest that the path to computer science and engineering is limited. Computer science majors faced few, if any, challenges, hoped to use computers as a tool to innovate and also participated in the same computer science program. For female engineering students, the essence of their experience focused on interaction at a young age with an expert in an engineering-related field as well as a strong desire to help solve world problems using engineering. These participants were able to articulate clearly future careers. In contrast, biology majors, faced more challenges and were undecided about their future career goals. These results suggest that a longitudinal study focused on women pursuing engineering and computer science fields is warranted; this will hopefully allow these findings to be substantiated and also for refinement of the revised theoretical model.

First experiments probing the collision of parallel magnetic fields using laser-produced plasmas

DOE PAGES

Rosenberg, M. J.; Li, C. K.; Fox, W.; ...

2015-04-08

Novel experiments to study the strongly-driven collision of parallel magnetic fields in β~10, laser-produced plasmas have been conducted using monoenergetic proton radiography. These experiments were designed to probe the process of magnetic flux pileup, which has been identified in prior laser-plasma experiments as a key physical mechanism in the reconnection of anti-parallel magnetic fields when the reconnection inflow is dominated by strong plasma flows. In the present experiments using colliding plasmas carrying parallel magnetic fields, the magnetic flux is found to be conserved and slightly compressed in the collision region. Two-dimensional (2D) particle-in-cell (PIC) simulations predict a stronger flux compressionmore » and amplification of the magnetic field strength, and this discrepancy is attributed to the three-dimensional (3D) collision geometry. Future experiments may drive a stronger collision and further explore flux pileup in the context of the strongly-driven interaction of magnetic fields.« less

EXPERIMENTAL DESIGN AND INSTRUMENTATION FOR A FIELD EXPERIMENT

EPA Science Inventory

This report concerns the design of a field experiment for a military setting in which the effects of carbon monoxide on neurobehavioral variables are to be studied. ield experiment is distinguished from a survey by the fact that independent variables are manipulated, just as in t...

Beyond Tokenism in the Field? On the Learning of a Mathematics Teacher Educator and Faculty Supervisor

ERIC Educational Resources Information Center

Nolan, Kathleen

2015-01-01

Supervision of student teachers in their field experience is one of the practices that characterizes the work of many teacher educators. This paper takes up the issue of mathematics teacher education field experience, drawing on the conceptual tools of Bourdieu's social field theory to interpret data from a self-study on the role of supervision…

Taking Them into the Field: Mathematics Teacher Candidate Learning about Equity-Oriented Teaching Practices in a Mediated Field Experience

ERIC Educational Resources Information Center

Campbell, Sara Sunshine

2012-01-01

Teacher education programs have been criticized as too theoretical with university courses disconnected from the practical realities of classrooms. This single case study investigates a model of teacher education that worked to bridge the coursework-fieldwork gap in teacher education. The Mediated Field Experience (MFE) is a field experience…

Critical Experiences for Field Geologists: Emergent Themes in Interest Development

ERIC Educational Resources Information Center

LaDue, Nicole D.; Pacheco, Heather A.

2013-01-01

Geoscience education researchers are working to understand how we can most effectively increase our overall geoscience workforce capacity. The present study employed an inductive approach to explore the critical experiences that led to the persistence of successful field geologists in this STEM field. Interviews with 29 professional field…

Magnetic field experiment for Voyagers 1 and 2

NASA Technical Reports Server (NTRS)

Behannon, K. W.; Aluna, M. H.; Burlaga, L. F.; Lepping, R. P.; Ness, N. F.; Neubauer, F. M.

1977-01-01

The magnetic field experiment to be carried on the Voyager 1 and 2 missions consists of dual low field (LFM) and high field magnetometer (HFM) systems. The dual systems provide greater reliability and, in the case of the LFM's, permit the separation of spacecraft magnetic fields from the ambient fields. Additional reliability is achieved through electronics redundancy. The wide dynamic ranges of plus or minus 0.5G for the LFM's and plus or minus 20G for the HFM's, low quantization uncertainty of plus or minus 0.002 gamma in the most sensitive (plus or minus 8 gamma) LFM range, low sensor RMS noise level of 0.006 gamma, and use of data compaction schemes to optimize the experiment information rate all combine to permit the study of a broad spectrum of phenomena during the mission. Planetary fields at Jupiter, Saturn, and possibly Uranus; satellites of these planets; solar wind and satellite interactions with the planetary fields; and the large-scale structure and microscale characteristics of the interplanetary magnetic field are studied. The interstellar field may also be measured.

Developing Standards-Based Geography Curricular Materials from Overseas Field Experiences for K-12 Teachers

ERIC Educational Resources Information Center

Oberle, Alex; Palacios, Fabian Araya

2012-01-01

Overseas experiences provide educators with exceptional opportunities to incorporate field study, firsthand experiences, and tangible artifacts into the classroom. Despite this potential, teachers must consider curricular standards that direct how such international endeavors can be integrated. Furthermore, geography curriculum development is more…

Effect of Biochar on Greenhouse Gas Emissions and Nitrogen Cycling in Laboratory and Field Experiments

NASA Astrophysics Data System (ADS)

Hagemann, Nikolas; Harter, Johannes; Kaldamukova, Radina; Ruser, Reiner; Graeff-Hönninger, Simone; Kappler, Andreas; Behrens, Sebastian

2014-05-01

The extensive use of nitrogen (N) fertilizers in agriculture is a major source of anthropogenic N2O emissions contributing 8% to global greenhouse gas emissions. Soil biochar amendment has been suggested as a means to reduce both CO2 and non-CO2 greenhouse gas emissions. The reduction of N2O emissions by biochar has been demonstrated repeatedly in field and laboratory experiments. However, the mechanisms of the reduction remain unclear. Further it is not known how biochar field-weathering affects GHG emissions and how agro-chemicals, such as the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP), that is often simultaneously applied together with commercial N-fertilizers, impact nitrogen transformation and N2O emissions from biochar amended soils. In order investigate the duration of the biochar effect on soil N2O emissions and its susceptibility to DMPP application we performed a microcosm and field study with a high-temperature (400 ° C) beech wood derived biochar (60 t ha-1 and 5 % (w/w) biochar in the field and microcosms, respectively). While the field site contained the biochar already for three years, soil and biochar were freshly mixed for the laboratory microcosm experiments. In both studies we quantified GHG emissions and soil nitrogen speciation (nitrate, nitrite, ammonium). While the field study was carried out over the whole vegetation period of the sunflower Helianthus annuus L., soil microcosm experiments were performed for up to 9 days at 28° C. In both experiments a N-fertilizer containing DMPP was applied either before planting of the sunflowers or at the beginning of soil microcosms incubation. Laboratory microcosm experiments were performed at 60% water filled pore space reflecting average field conditions. Our results show that biochar effectively reduced soil N2O emissions by up to 60 % in the field and in the soil microcosm experiments. No significant differences in N2O emission mitigation potential between field-aged and fresh biochar were observed for the specific biochar used in this study. N2O emission reduction occurred even in the presence of DMPP in the field and in the laboratory microcosms. Our results suggest that simultaneous measurements of soil samples from the same field site in the laboratory yield similar biochar effects to those quantified in the field and that the mechanisms of N2O mitigation seem to be independent of plant growth and application of the commercial nitrification inhibitor DMPP.

Commentary on "Studying eyewitness investigations in the field": a look forward.

PubMed

Steblay, Nancy Kay

2008-02-01

Schacter et al. (2007, this issue) address the controversy surrounding an Illinois pilot project that attempted to compare sequential versus simultaneous police lineup formats. The statement by these experts will guide the design and execution of future field lineup experiments. This commentary discusses three aspects of field studies that pose challenges as lineup experiments are interpreted: the imprecise meaning of the dependent measure (eyewitness decisions), the limitations of single studies, and the necessity to devise public policy from incomplete knowledge. A combination of laboratory and field information provides the means to determine best practices in eyewitness identification procedures.

Incidental Becomes Visible: A Comparison of School- and Community-Based Field Experience Narratives

ERIC Educational Resources Information Center

Holder, K. C.; Downey, Jayne A.

2008-01-01

The purpose of this study was to describe and compare student learning documented using written field experience summary narratives and occurring in community-based or school-based locations. Utilizing a hybrid portraiture--instrumental case study design, two researchers selected participants from undergraduate educational psychology courses using…

Providing Culturally Responsive Teaching in Field-Based and Student Teaching Experiences: A Case Study

ERIC Educational Resources Information Center

Kea, Cathy D.; Trent, Stanley C.

2013-01-01

This mixed design study chronicles the yearlong outcomes of 27 undergraduate preservice teacher candidates' ability to design and deliver culturally responsive lesson plans during field-based experience lesson observations and student teaching settings after receiving instruction in a special education methods course. While components of…

A Field Study Program in Analytical Chemistry for College Seniors.

ERIC Educational Resources Information Center

Langhus, D. L.; Flinchbaugh, D. A.

1986-01-01

Describes an elective field study program at Moravian College (Pennsylvania) in which seniors in analytical chemistry obtain first-hand experience at Bethlehem Steel Corporation. Discusses the program's planning phase, some method development projects done by students, experiences received in laboratory operations, and the evaluation of student…

Field Experience and Prospective Teachers' Mathematical Knowledge and Beliefs

ERIC Educational Resources Information Center

Jacobson, Erik D.

2017-01-01

This study (n = 1,044) used data from the Teacher Education and Development Study in Mathematics (TEDS-M) to examine the relationship between field experience focus (instruction- or exploration-focused), duration, and timing (early or not) and prospective elementary teachers' intertwined knowledge and beliefs about mathematics and mathematics…

Understanding behavioral responses of fish to pheromones in natural freshwater environments

USGS Publications Warehouse

Johnson, Nicholas S.; Li, Weiming

2010-01-01

There is an abundance of experimental studies and reviews that describe odorant-mediated behaviors of fish in laboratory microcosms, but research in natural field conditions has received considerably less attention. Fish pheromone studies in laboratory settings can be highly productive and allow for controlled experimental designs; however, laboratory tanks and flumes often cannot replicate all the physical, physiological and social contexts associated with natural environments. Field experiments can be a critical step in affirming and enhancing understanding of laboratory discoveries and often implicate the ecological significance of pheromones employed by fishes. When findings from laboratory experiments have been further tested in field environments, often different and sometimes contradictory conclusions are found. Examples include studies of sea lamprey (Petromyzon marinus) mating pheromones and fish alarm substances. Here, we review field research conducted on fish pheromones and alarm substances, highlighting the following topics: (1) contradictory results obtained in laboratory and field experiments, (2) how environmental context and physiological status influences behavior, (3) challenges and constraints of aquatic field research and (4) innovative techniques and experimental designs that advance understanding of fish chemical ecology through field research.

Physical barriers formed from gelling liquids: 1. numerical design of laboratory and field experiments

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

Finsterle, S.; Moridis, G.J.; Pruess, K.

1994-01-01

The emplacement of liquids under controlled viscosity conditions is investigated by means of numerical simulations. Design calculations are performed for a laboratory experiment on a decimeter scale, and a field experiment on a meter scale. The purpose of the laboratory experiment is to study the behavior of multiple gout plumes when injected in a porous medium. The calculations for the field trial aim at designing a grout injection test from a vertical well in order to create a grout plume of a significant extent in the subsurface.

Field Experience Study in a Traditional Setting.

ERIC Educational Resources Information Center

Perenich, Theresa A.

1978-01-01

A field experience in fashion marketing for Kansas State University students is described. The functions and responsibilities of the coordinator, the student, and the departmental supervisor are outlined, along with the evaluation processes used. (Author/LBH)

Visual Field Asymmetry in Attentional Capture

ERIC Educational Resources Information Center

Du, Feng; Abrams, Richard A.

2010-01-01

The present study examined the spatial distribution of involuntary attentional capture over the two visual hemi-fields. A new experiment, and an analysis of three previous experiments showed that distractors in the left visual field that matched a sought-for target in color produced a much larger capture effect than identical distractors in the…

An MHD Dynamo Experiment.

NASA Astrophysics Data System (ADS)

O'Connell, R.; Forest, C. B.; Plard, F.; Kendrick, R.; Lovell, T.; Thomas, M.; Bonazza, R.; Jensen, T.; Politzer, P.; Gerritsen, W.; McDowell, M.

1997-11-01

A MHD experiment is being constructed which will have the possibility of showing dynamo action: the self--generation of currents from fluid motion. The design allows sufficient experimental flexibility and diagnostic access to study a variety of issues central to dynamo theory, including mean--field electrodynamics and saturation (backreaction physics). Initially, helical flows required for dynamo action will be driven by propellers embedded in liquid sodium. The flow fields will first be measured using laser doppler velocimetry in a water experiment with an identical fluid Reynolds number. The magnetic field evolution will then be predicted using a MHD code, replacing the water with sodium; if growing magnetic fields are found, the experiment will be repeated with sodium.

Magnetic Eigenmodes in the Madison Dynamo Experiment

NASA Astrophysics Data System (ADS)

Nornberg, M. D.; Bayliss, R. A.; Forest, C. B.; Kendrick, R. D.; O'Connell, R.; Spence, E. J.

2002-11-01

A spherical dynamo experiment has been constructed at the University of Wisconsin's liquid sodium facility. The goals of the experiment are to observe and understand magnetic instabilities driven by flow shear in MHD systems, investigate MHD turbulence for magnetic Reynolds numbers of 100, and understand the role of fluid turbulence in current generation. Magnetic field generation is only possible for specific flow geometries. We have studied and achieved simple roll flow geometries in a full scale water experiment. Results from the water experiment have guided the design of the sodium experiment. The experiment consists of a 1 m diameter, spherical stainless steel vessel filled with liquid sodium at 110 Celsius. Two 100 Hp motors with impellers drive flows in the liquid sodium with flow velocities of 15 m/s. A gaussian grid of 66 Hall probes on the surface of the sodium vessel measure the generated external magnetic field. Hall probe feed-thru arrays measure the internal field. A pair of magnetic field coils produce a roughly uniform field inside the sphere with a centerline field strength of 100 gauss. Preliminary investigations include measurements of the turbulent electromotive force and excitation of magnetic eigenmodes.

Dewey's Concept of Experience for Inquiry-Based Landscape Drawing during Field Studies

ERIC Educational Resources Information Center

Tillmann, Alexander; Albrecht, Volker; Wunderlich, Jürgen

2017-01-01

The epistemological and educational philosophy of John Dewey is used as a theoretical basis to analyze processes of knowledge construction during geographical field studies. The experience of landscape drawing as a method of inquiry and a starting point for research-based learning is empirically evaluated. The basic drawing skills are acquired…

The Efficacy of Drama in Field Experience: A Qualitative Study Using MAXQDA

ERIC Educational Resources Information Center

Elaldi, Senel; Yerliyurt, Nazli Sila

2017-01-01

This study attempted to evaluate the views of senior preservice preschool teachers on the efficacy of drama activities in their field experience in terms of the effect of students' learning, socialization, individual or group work skills and school connectedness and also disclosed the suggestions of senior preservice preschool teachers for faculty…

Patterns of Generative Discourse in Online Discussions during the Field Experience

ERIC Educational Resources Information Center

Lafferty, Karen Elizabeth; Kopcha, Theodore J.

2016-01-01

This study examined how online discussion of the classroom challenges that preservice teachers face during the field experience can lead to problem solving and knowledge generation. Drawing upon Horn and Little's (2010) descriptions of generative discourse, the study examined how a community of preservice teachers, their university supervisors,…

The Power of Relationship Building in International Short-Term Field Study Experiences at the Graduate Level

ERIC Educational Resources Information Center

Davis, Brittany; Coryell, Joellen E.

2016-01-01

This paper derives from a case study of a 10-day cross-cultural field study experience held in Italy in which graduate students from master and doctoral levels in adult education participated. During group reflections, several students who participated in the course expressed the value of learning through personal connections made with students as…

Influence of the mode of deformation on recrystallisation behaviour of titanium through experiments, mean field theory and phase field model

NASA Astrophysics Data System (ADS)

Athreya, C. N.; Mukilventhan, A.; Suwas, Satyam; Vedantam, Srikanth; Subramanya Sarma, V.

2018-04-01

The influence of the mode of deformation on recrystallisation behaviour of Ti was studied by experiments and modelling. Ti samples were deformed through torsion and rolling to the same equivalent strain of 0.5. The deformed samples were annealed at different temperatures for different time durations and the recrystallisation kinetics were compared. Recrystallisation is found to be faster in the rolled samples compared to the torsion deformed samples. This is attributed to the differences in stored energy and number of nuclei per unit area in the two modes of deformation. Considering decay in stored energy during recrystallisation, the grain boundary mobility was estimated through a mean field model. The activation energy for recrystallisation obtained from experiments matched with the activation energy for grain boundary migration obtained from mobility calculation. A multi-phase field model (with mobility estimated from the mean field model as a constitutive input) was used to simulate the kinetics, microstructure and texture evolution. The recrystallisation kinetics and grain size distributions obtained from experiments matched reasonably well with the phase field simulations. The recrystallisation texture predicted through phase field simulations compares well with experiments though few additional texture components are present in simulations. This is attributed to the anisotropy in grain boundary mobility, which is not accounted for in the present study.

Teacher Training in Urban Settings: Inquiry, Efficacy, and Culturally Diverse Field Placements

ERIC Educational Resources Information Center

McGlamery, Sheryl L.; Franks, Bridget A.; Shillingstad, Saundra L.

2016-01-01

This study describes two years of findings with a unique field experience (teaching science inquiry activities to African-American girls in a summer STEM camp) for preservice elementary education majors. It reports on the effects of the field experience, in conjunction with blocked science and mathematics methods courses, on preservice teachers'…

A Grounded Theory of Preservice Music Educators' Lesson Planning Processes within Field Experience Methods Courses

ERIC Educational Resources Information Center

Parker, Elizabeth Cassidy; Bond, Vanessa L.; Powell, Sean R.

2017-01-01

The purpose of this grounded theory study was to understand the process of field experience lesson planning for preservice music educators enrolled in choral, general, and instrumental music education courses within three university contexts. Data sources included multiple interviews, written responses, and field texts from 42 participants. Four…

Factors That Influence Student's Satisfaction in an Environmental Field Day Experience

ERIC Educational Resources Information Center

Wang, Hui-Hui; Carlson, Stephan P.

2011-01-01

A field trip is a common strategy used by educators to bring out-of-school learning experience into schools. Many research studies suggest a field trip will not only bring an individual close to the real-world, but may also increase an individual's environmental knowledge and responsible behaviors. Program evaluations usually focus on the…

Do lab-derived distribution coefficient values of pesticides match distribution coefficient values determined from column and field-scale experiments? A critical analysis of relevant literature.

PubMed

Vereecken, H; Vanderborght, J; Kasteel, R; Spiteller, M; Schäffer, A; Close, M

2011-01-01

In this study, we analyzed sorption parameters for pesticides that were derived from batch and column or batch and field experiments. The batch experiments analyzed in this study were run with the same pesticide and soil as in the column and field experiments. We analyzed the relationship between the pore water velocity of the column and field experiments, solute residence times, and sorption parameters, such as the organic carbon normalized distribution coefficient ( ) and the mass exchange coefficient in kinetic models, as well as the predictability of sorption parameters from basic soil properties. The batch/column analysis included 38 studies with a total of 139 observations. The batch/field analysis included five studies, resulting in a dataset of 24 observations. For the batch/column data, power law relationships between pore water velocity, residence time, and sorption constants were derived. The unexplained variability in these equations was reduced, taking into account the saturation status and the packing status (disturbed-undisturbed) of the soil sample. A new regression equation was derived that allows estimating the values derived from column experiments using organic matter and bulk density with an value of 0.56. Regression analysis of the batch/column data showed that the relationship between batch- and column-derived values depends on the saturation status and packing of the soil column. Analysis of the batch/field data showed that as the batch-derived value becomes larger, field-derived values tend to be lower than the corresponding batch-derived values, and vice versa. The present dataset also showed that the variability in the ratio of batch- to column-derived value increases with increasing pore water velocity, with a maximum value approaching 3.5. American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.

Augmented Reality in a Simulated Tower Environment: Effect of Field of View on Aircraft Detection

NASA Technical Reports Server (NTRS)

Ellis, Stephen R.; Adelstein, Bernard D.; Reisman, Ronald J.; Schmidt-Ott, Joelle R.; Gips, Jonathan; Krozel, Jimmy; Cohen, Malcolm (Technical Monitor)

2002-01-01

An optical see-through, augmented reality display was used to study subjects' ability to detect aircraft maneuvering and landing at the Dallas Ft. Worth International airport in an ATC Tower simulation. Subjects monitored the traffic patterns as if from the airport's western control tower. Three binocular fields of view (14 deg, 28 deg and 47 deg) were studied in an independent groups' design to measure the degradation in detection performance associated with the visual field restrictions. In a second experiment the 14 deg and 28 deg fields were presented either with 46% binocular overlap or 100% overlap for separate groups. The near asymptotic results of the first experiment suggest that binocular fields of view much greater than 47% are unlikely to dramatically improve performance; and those of the second experiment suggest that partial binocular overlap is feasible for augmented reality displays such as may be used for ATC tower applications.

Use of English Vocabulary Learning Strategies by Thai Tertiary-Level Students in Relation to Fields of Study and Language-Learning Experiences

ERIC Educational Resources Information Center

Boonkongsaen, Nathaya; Intaraprasert, Channarong

2014-01-01

The present study was intended to examine the effects of 1) fields of study (arts, business and science-oriented); and 2) language-learning experiences (whether limited or non-limited to formal classroom instructions) on the use of VLSs among Thai tertiary-level students. The participants were 905 Thai EFL students studying in the Northeast of…

The importance of aerodynamics for prosthetic limb design used by competitive cyclists with an amputation: An introduction.

PubMed

Dyer, Bryce

2015-06-01

This study introduces the importance of the aerodynamics to prosthetic limb design for athletes with either a lower-limb or upper-limb amputation. The study comprises two elements: 1) An initial experiment investigating the stability of outdoor velodrome-based field tests, and 2) An experiment evaluating the application of outdoor velodrome aerodynamic field tests to detect small-scale changes in aerodynamic drag respective of prosthetic limb componentry changes. An outdoor field-testing method is used to detect small and repeatable changes in the aerodynamic drag of an able-bodied cyclist. These changes were made at levels typical of alterations in prosthetic componentry. The field-based test method of assessment is used at a smaller level of resolution than previously reported. With a carefully applied protocol, the field test method proved to be statistically stable. The results of the field test experiments demonstrate a noticeable change in overall athlete performance. Aerodynamic refinement of artificial limbs is worthwhile for athletes looking to maximise their competitive performance. A field-testing method illustrates the importance of the aerodynamic optimisation of prosthetic limb components. The field-testing protocol undertaken in this study gives an accessible and affordable means of doing so by prosthetists and sports engineers. Using simple and accessible field-testing methods, this exploratory experiment demonstrates how small changes to riders' equipment, consummate of the scale of a small change in prosthetics componentry, can affect the performance of an athlete. Prosthetists should consider such opportunities for performance enhancement when possible. © The International Society for Prosthetics and Orthotics 2014.

Inter-hemispheric interaction facilitates face processing.

PubMed

Compton, Rebecca J

2002-01-01

Many recent studies have revealed that interaction between the left and right cerebral hemispheres can aid in task performance, but these studies have tended to examine perception of simple stimuli such as letters, digits or simple shapes, which may have limited naturalistic validity. The present study extends these prior findings to a more naturalistic face perception task. Matching tasks required subjects to indicate when a target face matched one of two probe faces. Matches could be either across-field, requiring inter-hemispheric interaction, or within-field, not requiring inter-hemispheric interaction. Subjects indicated when faces matched in emotional expression (Experiment 1; n=32) or in character identity (Experiment 2; n=32). In both experiments, across-field performance was significantly better than within-field performance, supporting the primary hypothesis. Further, this advantage was greater for the more difficult character identity task. Results offer qualified support for the hypothesis that inter-hemispheric interaction is especially advantageous as task demands increase.

Transforming Pedagogy: Changing Perspectives from Teacher-Centered to Learner-Centered

ERIC Educational Resources Information Center

Dole, Sharon; Bloom, Lisa; Kowalske, Kristy

2016-01-01

This study used an online-structured interview methodology to examine the impact of an intensive field experience in facilitating problem (PBL) and project-based learning (PjBL) on teachers' pedagogy. The purpose of the study was to determine to what extent the field experience had transformed their teaching. Data were collected in the form of…

Reflecting on Field Studies in Teacher Education: Experiences of Student Teachers in Sweden

ERIC Educational Resources Information Center

Niklasson, Laila; Sandberg, Anette

2012-01-01

The aim of this article is to describe how field studies can be useful in teacher education. While participating in a specialty area called "Play, learning and development," student teachers collected data about their own and young children's experience and perception of the outdoor environment. They observed, carried out interviews from…

The Fragility of Ecological Pedagogy: Elementary Social Studies Standards and Possibilities of New Materialism

ERIC Educational Resources Information Center

Sonu, Debbie; Snaza, Nathan

2015-01-01

The greatest challenge facing the field of environmentalism includes ontological questions over the human subject and its desensitization from landscapes of experience. In this article the authors draw from field experiences in New York City elementary schools (such as observations of teachers, NYS Scope and Sequence Standards for Social Studies,…

Teaching Statistical Inference for Causal Effects in Experiments and Observational Studies

ERIC Educational Resources Information Center

Rubin, Donald B.

2004-01-01

Inference for causal effects is a critical activity in many branches of science and public policy. The field of statistics is the one field most suited to address such problems, whether from designed experiments or observational studies. Consequently, it is arguably essential that departments of statistics teach courses in causal inference to both…

Marine Radioactivity Studies in the Suez Canal, Part II: Field Experiments and a Modelling Study of Dispersion

NASA Astrophysics Data System (ADS)

Abril, J. M.; Abdel-Aal, M. M.; Al-Gamal, S. A.; Abdel-Hay, F. A.; Zahar, H. M.

2000-04-01

In this paper we take advantage of the two field tracing experiments carried out under the IAEA project EGY/07/002, to develop a modelling study on the dispersion of radioactive pollution in the Suez Canal. The experiments were accomplished by using rhodamine B as a tracer, and water samples were measured by luminescence spectrometry. The presence of natural luminescent particles in the canal waters limited the use of some field data. During experiments, water levels, velocities, wind and other physical parameters were recorded to supply appropriate information for the modelling work. From this data set, the hydrodynamics of the studied area has been reasonably described. We apply a 1-D-Gaussian and 2-D modelling approaches to predict the position and the spatial shape of the plume. The use of different formulations for dispersion coefficients is studied. These dispersion coefficients are then applied in a 2-D-hydrodynamic and dispersion model for the Bitter Lake to investigate different scenarios of accidental discharges.

Field size, length, and width distributions based on LACIE ground truth data. [large area crop inventory experiment

NASA Technical Reports Server (NTRS)

Pitts, D. E.; Badhwar, G.

1980-01-01

The development of agricultural remote sensing systems requires knowledge of agricultural field size distributions so that the sensors, sampling frames, image interpretation schemes, registration systems, and classification systems can be properly designed. Malila et al. (1976) studied the field size distribution for wheat and all other crops in two Kansas LACIE (Large Area Crop Inventory Experiment) intensive test sites using ground observations of the crops and measurements of their field areas based on current year rectified aerial photomaps. The field area and size distributions reported in the present investigation are derived from a representative subset of a stratified random sample of LACIE sample segments. In contrast to previous work, the obtained results indicate that most field-size distributions are not log-normally distributed. The most common field size observed in this study was 10 acres for most crops studied.

Plot-scale field experiment of surface hydrologic processes with EOS implications

NASA Technical Reports Server (NTRS)

Laymon, Charles A.; Macari, Emir J.; Costes, Nicholas C.

1992-01-01

Plot-scale hydrologic field studies were initiated at NASA Marshall Space Flight Center to a) investigate the spatial and temporal variability of surface and subsurface hydrologic processes, particularly as affected by vegetation, and b) develop experimental techniques and associated instrumentation methodology to study hydrologic processes at increasingly large spatial scales. About 150 instruments, most of which are remotely operated, have been installed at the field site to monitor ground atmospheric conditions, precipitation, interception, soil-water status, and energy flux. This paper describes the nature of the field experiment, instrumentation and sampling rationale, and presents preliminary findings.

Field Research in the Teaching of Undergraduate Soil Science

NASA Astrophysics Data System (ADS)

Brevik, Eric C.; Senturklu, Songul; Landblom, Douglas

2015-04-01

Several studies have demonstrated that undergraduate students benefit from research experiences. Benefits of undergraduate research include 1) personal and intellectual development, 2) more and closer contact with faculty, 3) the use of active learning techniques, 4) creation of high expectations, 5) development of creative and problem-solving skills, 6) greater independence and intrinsic motivation to learn, and 7) exposure to practical skills. The scientific discipline also benefits, as studies have shown that undergraduates who engage in research experiences are more likely to remain science majors and finish their degree program (Lopatto, 2007). Research experiences come as close as possible to allowing undergraduates to experience what it is like to be an academic or research member of their profession working to advance their discipline. Soils form in the field, therefore, field experiences are very important in developing a complete and holistic understanding of soil science. Combining undergraduate research with field experiences can provide extremely beneficial outcomes to the undergraduate student, including increased understanding of and appreciation for detailed descriptions and data analysis as well as an enhanced ability to see how various parts of their undergraduate education come together to understand a complex problem. The experiences of the authors in working with undergraduate students on field-based research projects will be discussed, along with examples of some of the undergraduate research projects that have been undertaken. In addition, student impressions of their research experiences will be presented. Reference Lopatto, D. 2007. Undergraduate research experiences support science career decisions and active learning. CBE -- Life Sciences Education 6:297-306.

Interpretation of the electric fields measured in an ionospheric critical ionization velocity experiment

NASA Technical Reports Server (NTRS)

Brenning, N.; Faelthammar, C.-G.; Marklund, G.; Haerendel, G.; Kelley, M. C.; Pfaff, R.

1991-01-01

The quasi-dc electric fields measured in the CRIT I ionospheric release experiment are studied. In the experiment, two identical barium shaped charges were fired toward a main payload, and three-dimensional measurements of the electric field inside the streams were made. The relevance of proposed mechanisms for electron heating in the critical ionization velocity (CIV) mechanism is addressed. It is concluded that both the 'homogeneous' and the 'ionizing front' models probably are valid, but in different parts of the streams. It is also possible that electrons are directly accelerated by a magnetic field-aligned component of the electric field. The coupling between the ambient ionosphere and the ionized barium stream is more complicated that is usually assumed in CIV theories, with strong magnetic-field-aligned electric fields and probably current limitation as important processes.

Rats avoid exposure to HVdc electric fields: a dose response study.

PubMed

Creim, J A; Lovely, R H; Weigel, R J; Forsythe, W C; Anderson, L E

1993-01-01

Rats, given the choice, avoid exposure to alternating current (ac) 60-Hz electric fields at intensities > or = 75 kV/m. This study investigated the generality of this behavior by studying the response of rats when exposed to high voltage direct current (HVdc) electric fields. Three hundred eighty male Long Evans rats were studied in 9 experiments with 40 rats per experiment and in one experiment with 20 rats to determine 1) if rats avoid exposure to HVdc electric fields of varying field strengths, and 2) if avoidance did occur, what role, if any, the concentration of air ions would have on the avoidance behavior. In all experiments a three-compartment glass shuttlebox was used; either the left or right compartment could be exposed to a combination of HVdc electric fields and air ions while the other compartment remained sham-exposed. The third, center compartment was a transition zone between exposure and sham-exposure. In each experiment, the rats were individually assessed in 1-h sessions where half of the rats (n = 20) had the choice to locomote between the two sides being exposed or sham-exposed, while the other half of the rats (n = 20) were sham-exposed regardless of their location, except in one experiment where there was no sham-exposed group. The exposure levels for the first six experiments were 80, 55, 42.5, 30, -36, and -55 kV/m, respectively. The air ion concentration was constant at 1.4 x 10(6) ions/cc for the four positive exposure levels and -1.4 x 10(6) ions/cc for the two negative exposure levels. Rats having a choice between exposure and non-exposure relative to always sham-exposed control animals significantly reduced the amount of time spent on the exposed side at 80 kV/m (P < .002) as they did at both 55 and -55 kV/m (P < .005). No significant differences between groups were observed at 42.5, 30, or -36 kV/m. To determine what role the air ion concentration might have had on the avoidance behavior at field strengths of 55 kV/m or greater, four additional experiments were conducted. The HVdc exposure level was held constant at either -55 kV/m (for three experiments) or -55 kV/m (for 1 experiment) while the air ion concentration was varied between experiments at 2.5 x 10(5) ions/cc, 1.0 x 10(4) for two of the experiments and was below the measurement limit (< +/- 2 x 10(3) ions/cc) for the other two experiments at 55 and -55 kV/m.(ABSTRACT TRUNCATED AT 400 WORDS)

Factors motivating Cambodian American students to go to college and to study STEM fields

NASA Astrophysics Data System (ADS)

Sann, Visna

Cambodian Americans graduate from college at a lower rate than most Asian American groups. This qualitative study involved interviewing five current Cambodian American college students. This study examined how participants' high school experiences contributed to their decisions to go to college and to study STEM fields, how parental influences guided participants to college, and how college experiences influenced their decisions to stay and succeed in STEM fields. Findings from this study suggest: having supportive teachers in high school may have been important in motivating participants to go to college and to study STEM Fields, Cambodian parents tell stories of their lives in Cambodia to motivate their children to go to college, and Cambodian club on campus was a socially and academically supportive place.

Comparison of collectors of airborne spray drift. Experiments in a wind tunnel and field measurements.

PubMed

Arvidsson, Tommy; Bergström, Lars; Kreuger, Jenny

2011-06-01

In this study, the collecting efficiency of different samplers of airborne drift was compared both in wind tunnel and in field experiments. The aim was to select an appropriate sampler for collecting airborne spray drift under field conditions. The wind tunnel study examined three static samplers and one dynamic sampler. The dynamic sampler had the highest overall collecting efficiency. Among the static samplers, the pipe cleaner collector had the highest efficiency. These two samplers were selected for evaluation in the subsequent field study. Results from 29 individual field experiments showed that the pipe cleaner collector on average had a 10% lower collecting efficiency than the dynamic sampler. However, the deposits on the pipe cleaners generally were highest at the 0.5 m level, and for the dynamic sampler at the 1 m level. It was concluded from the wind tunnel part of the study that the amount of drift collected on the static collectors had a more strongly positive correlation with increasing wind speed compared with the dynamic sampler. In the field study, the difference in efficiency between the two types of collector was fairly small. As the difference in collecting efficiency between the different types of sampler was small, the dynamic sampler was selected for further measurements of airborne drift under field conditions owing to its more well-defined collecting area. This study of collecting efficiency of airborne spray drift of static and dynamic samplers under field conditions contributes to increasing knowledge in this field of research. Copyright © 2011 Society of Chemical Industry.

An illustrated gardener's guide to transgenic Arabidopsis field experiments.

PubMed

Frenkel, Martin; Jänkänpää, Hanna Johansson; Moen, Jon; Jansson, Stefan

2008-01-01

Field studies with transgenic Arabidopsis lines have been performed over 8 yr, to better understand the influence that certain genes have on plant performance. Many (if not most) plant phenotypes cannot be observed under the near constant, low-stress conditions in growth chambers, making field experiments necessary. However, there are challenges in performing such experiments: permission must be obtained and regulations obeyed, the profound influence of uncontrollable biotic and abiotic factors has to be considered, and experimental design has to be strictly controlled. The aim here is to provide inspiration and guidelines for researchers who are not used to setting up such experiments, allowing others to learn from our mistakes. This is believed to be the first example of a 'manual' for field experiments with transgenic Arabidopsis plants. Many of the challenges encountered are common for all field experiments, and many researchers from ecological backgrounds are skilled in such methods. There is huge potential in combining the detailed mechanistic understanding of molecular biologists with ecologists' expertise in examining plant performance under field conditions, and it is suggested that more interdisciplinary collaborations will open up new scientific avenues to aid analyses of the roles of genetic and physiological variation in natural systems.

Sensitivity of fields generated within magnetically shielded volumes to changes in magnetic permeability

NASA Astrophysics Data System (ADS)

Andalib, T.; Martin, J. W.; Bidinosti, C. P.; Mammei, R. R.; Jamieson, B.; Lang, M.; Kikawa, T.

2017-09-01

Future experiments seeking to measure the neutron electric dipole moment (nEDM) require stable and homogeneous magnetic fields. Normally these experiments use a coil internal to a passively magnetically shielded volume to generate the magnetic field. The stability of the magnetic field generated by the coil within the magnetically shielded volume may be influenced by a number of factors. The factor studied here is the dependence of the internally generated field on the magnetic permeability μ of the shield material. We provide measurements of the temperature-dependence of the permeability of the material used in a set of prototype magnetic shields, using experimental parameters nearer to those of nEDM experiments than previously reported in the literature. Our measurements imply a range of 1/μ dμ/dT from 0-2.7%/K. Assuming typical nEDM experiment coil and shield parameters gives μ/B0 dB0/dμ = 0.01, resulting in a temperature dependence of the magnetic field in a typical nEDM experiment of dB0/dT = 0 - 270 pT/K for B0 = 1 μT. The results are useful for estimating the necessary level of temperature control in nEDM experiments.

The Workplace Experiences of Beginning Teachers in Three Countries: A Message for Initial Teacher Education from the Field

ERIC Educational Resources Information Center

du Plessis, Anna Elizabeth; Sunde, Eva

2017-01-01

Previous research indicates that beginning teachers are not fully prepared for what awaits them in the workforce. This study highlights the value of partnerships among higher education providers, schools and employers and links the experiences of beginning teachers to initial teacher education (ITE). Real-life experiences from the field provide…

Teachers' Perceptions of Their Mentoring Role in Three Different Clinical Settings: Student Teaching, Early Field Experiences, and Entry Year Teaching

ERIC Educational Resources Information Center

Gut, Dianne M.; Beam, Pamela C.; Henning, John E.; Cochran, Deborah C.; Knight, Rhonda Talford

2014-01-01

The purpose of this study was to determine the differences in mentoring across three different clinical settings: student teaching, early field experiences, and entry year teachers. Eighteen teachers with mentoring experience in all three clinical settings were selected and interviewed. The teachers' expectations for teacher development,…

Preparing for Democracy and Diversity: The Impact of a Community-based Field Experience on Preservice Teachers' Knowledge, Skills, and Attitudes.

ERIC Educational Resources Information Center

Potthoff, Dennis E.; Dinsmore, Julie; Eifler, Karen; Stirtz, Geraldine; Walsh, Tom; Ziebarth, Jane

2000-01-01

Describes a study in which student teachers worked in community-based human service agencies in order to double their field experience hours. Surveys and interviews with students, agency personnel, and education faculty indicated that the experience fostered knowledge, skills, and attitudes consistent with the university's promotion of democracy…

Toward a Holistic View: Analysis of Pre-Service Teachers' Professional Vision in Field Experiences and Its Implications

ERIC Educational Resources Information Center

Lee, Ji-Eun

2016-01-01

This study investigated the aspects of learning and teaching that pre-service teachers examined at distinct time periods while taking on different roles. Participants reported on what they noticed from their past learning experiences as students, as well as their current field experiences as student teachers. Their reflective critique was created…

Biofilm resilience to desiccation in groundwater aquifers: a laboratory and field study.

PubMed

Weaver, L; Webber, J B; Hickson, A C; Abraham, P M; Close, M E

2015-05-01

Groundwater is used as a precious resource for drinking water worldwide. Increasing anthropogenic activity is putting increasing pressure on groundwater resources. One impact of increased groundwater abstraction coupled with increasing dry weather events is the lowering of groundwater levels within aquifers. Biofilms within groundwater aquifers offer protection to the groundwater by removing contaminants entering the aquifer systems from land use activities. The study presented investigated the impact of desiccation events on the biofilms present in groundwater aquifers using field and laboratory experiments. In both field and laboratory experiments a reduction in enzyme activity (glucosidase, esterase and phosphatase) was seen during desiccation compared to wet controls. However, comparing all the data together no significant differences were seen between either wet or desiccated samples or between the start and end of the experiments. In both field and laboratory experiments enzyme activity recovered to start levels after return to wet conditions. The study shows that biofilms within groundwater systems are resilient and can withstand periods of desiccation (4 months). Copyright © 2014 Elsevier B.V. All rights reserved.

Optimization Design of Bipolar Plate Flow Field in PEM Stack

NASA Astrophysics Data System (ADS)

Wen, Ming; He, Kanghao; Li, Peilong; Yang, Lei; Deng, Li; Jiang, Fei; Yao, Yong

2017-12-01

A new design of bipolar plate flow field in proton exchange membrane (PEM) stack was presented to develop a high-performance transfer efficiency of the two-phase flow. Two different flow fields were studied by using numerical simulations and the performance of the flow fields was presented. the hydrodynamic properties include pressure gap between inlet and outlet, the Reynold’s number of the two types were compared based on the Navier-Stokes equations. Computer aided optimization software was implemented in the design of experiments of the preferable flow field. The design of experiments (DOE) for the favorable concept was carried out to study the hydrodynamic properties when changing the design parameters of the bipolar plate.

Any Light Particle Search (ALPS)

NASA Astrophysics Data System (ADS)

Spector, Aaron; Any Light Particle Search (ALPS) Collaboration

2016-03-01

High power laser fields enabled by technologies developed for ground-based gravitational-wave observatories open up new opportunities for fundamental physics studies. One of these options is the search for axions and axion-like particles in a pure laboratory experiment. The axion is a solution to the strong CP-problem and a potential dark matter candidate. The axion has also been proposed as an additional channel to cool stars as well as a potential explanation for the TeV transparency problem. The German-US ALPS collaboration is setting up a light-shining-through-walls (LSW) experiment at DESY. LSW experiments are based on the simple idea that a high power laser field traversing a static magnetic field will transform partly into a relativistic axion field. This axion field will travel through an opaque wall into a second static magnetic field region where it turns partly back into an electromagnetic wave field with the same frequency as the laser. The ALPS collaboration is working towards a large scale LSW experiment at DESY in Hamburg, Germany. I will report on the status of the ALPS experiment. This work is supported by the Deutsche Forschungsgemeinschaft, PRISMA, the Helmholtz Association, the National Science Foundation and the Heising-Simons Foundation.

On Whether Angular Momentum in Electric and Magnetic Fields Radiates to Infinity

NASA Technical Reports Server (NTRS)

Canning, Francis X.; Knudsen, Steven

2006-01-01

The Feynman Disk experiment and a related thought experiment with a static magnetic field and capacitor are studied. The mechanical torque integrated over time (angular impulse) is related to the angular momentum in the electric/magnetic field. This is not called an electromagnetic field since quasi-static as well as electromagnetic effects are included. The angular momentum in the electric/magnetic field is examined to determine its static and radiative components. This comparison was then examined to see if it clarified the Abraham-Minkowski paradox.

A Case Study of Professional Boundary Issues Experienced by Undergraduate Psychology Students in a Supervised Field Experience Course

ERIC Educational Resources Information Center

Sharp, Gwen; Yao, Richard; Cresiski, Robin; Hahn, Kate

2013-01-01

There has been little research on the types of boundary issues encountered in undergraduate psychology field experience courses, despite the increased popularity of such courses. This case study identifies the frequency and types of boundary issues faced by undergraduate psychology students enrolled in such a course, including the most common…

The Effects of Special Training and Field Experiences upon Preservice Teachers' Level of Comfort with Multicultural Music Teaching Situations.

ERIC Educational Resources Information Center

Barry, Nancy H.

This paper reports on a study examining preservice teachers' level of comfort in working with students and colleagues of a different race, and exploring the effects of special training and field experience on their level of comfort with multicultural situations. The study involved 55 predominantly white preservice teachers enrolled in 2 different…

Simulation of Coast Guard Vessel Traffic Service Operations by Model and Experiment

DOT National Transportation Integrated Search

1980-09-01

A technique for computer simulation of operations of U.S. Coast Guard Vessel Traffic Services is described and verified with data obtained in four field studies. Uses of the Technique are discussed and illustrated. A field experiment is described in ...

A sensor fusion field experiment in forest ecosystem dynamics

NASA Technical Reports Server (NTRS)

Smith, James A.; Ranson, K. Jon; Williams, Darrel L.; Levine, Elissa R.; Goltz, Stewart M.

1990-01-01

The background of the Forest Ecosystem Dynamics field campaign is presented, a progress report on the analysis of the collected data and related modeling activities is provided, and plans for future experiments at different points in the phenological cycle are outlined. The ecological overview of the study site is presented, and attention is focused on forest stands, needles, and atmospheric measurements. Sensor deployment and thermal and microwave observations are discussed, along with two examples of the optical radiation measurements obtained during the experiment in support of radiative transfer modeling. Future activities pertaining to an archival system, synthetic aperture radar, carbon acquisition modeling, and upcoming field experiments are considered.

Utilizing an Artificial Outcrop to Scaffold Learning between Laboratory and Field Experiences in a College-Level Introductory Geology Course

ERIC Educational Resources Information Center

Wilson, Meredith

2012-01-01

Geologic field trips are among the most beneficial learning experiences for students as they engage the topic of geology, but they are also difficult environments to maximize learning. This action research study explored one facet of the problems associated with teaching geology in the field by attempting to improve the transition of undergraduate…

Differential Experiences of Male and Female Aspirants in Public School Administration: A Closer Look at Perceptions Within the Field.

ERIC Educational Resources Information Center

Oller, C. Sakre

This thesis explores the idea that aspirants in the field of educational administration, particularly females, may be remiss in assessing both the capabilities they bring to the field and their individual chances of finding work there. Perceptions of the subjects were studied via survey research in three main areas: graduate school experiences,…

Experiments on Turbulent Modifications to Ohm's Law in the Madison Dynamo Experiment

NASA Astrophysics Data System (ADS)

Goldwin, J.; O'Connell, R.; Kendrick, R.; Bastian, N.; Forest, C. B.

1998-11-01

Theories of MHD turbulence predict the existence of an anomalous resistivity and field-aligned current generation: j = β nabla × B + α B. The dynamo experiment being built at the University of Wisconsin-Madison is well suited for quantifying the turbulent transport coefficients α and β. The experiment is a spherical volume of liquid sodium with helical flows driven by propellers and high Reynolds number (Re ≈ 10^7), making it well suited for these studies. Two experiments are proposed: (1) A Helmholtz coil will produce a magnetic field in the z-direction, and the resulting toroidal field will be measured for the anomalous resistivity-the β-effect and (2) A toroidal magnetic field will be applied to the sphere through currents in a center column, and the induced toroidal current will be measured with a Rogowski coil-the α-effect. Complete measurements of turbulent velocity fields (including the turbulent helicity density) are being made in a dimensionally similar water experiment (water and sodium have the same viscosity and mass density) such that the magnitude of the α and β values can be estimated for the sodium experiment.

Hemispheric specialization in quantification processes.

PubMed

Pasini, M; Tessari, A

2001-01-01

Three experiments were carried out to study hemispheric specialization for subitizing (the rapid enumeration of small patterns) and counting (the serial quantification process based on some formal principles). The experiments consist of numerosity identification of dot patterns presented in one visual field, with a tachistoscopic technique, or eye movements monitored through glasses, and comparison between centrally presented dot patterns and lateralized tachistoscopically presented digits. Our experiments show left visual field advantage in the identification and comparison tasks in the subitizing range, whereas right visual field advantage has been found in the comparison task for the counting range.

Bacterial Transport in Heterogeneous Porous Media: Laboratory and Field Experiments

NASA Astrophysics Data System (ADS)

Fuller, M. E.

2001-12-01

A fully instrumented research site for examining field-scale bacterial transport has been established on the eastern shore of Virginia. Studies employing intact sediment cores from the South Oyster site have been performed to examine the effects of physical and chemical heterogeneity, to derive transport parameters, and to aid in the selection of bacterial strains for use in field experiments. A variety of innovative methods for tracking bacteria were developed and evaluated under both laboratory and field conditions, providing the tools to detect target cell concentrations in groundwater down to <20 cells/ml, and to perform real-time monitoring in the field. Comprehensive modeling efforts have provided a framework for the layout and instrumentation of the field site, and have aided in the design and interpretation of field-scale bacterial transport experiments. Field transport experiments were conducted in both aerobic and an anoxic flow cells to determine the effects of physical and chemical heterogeneity on field-scale bacterial transport. The results of this research not only contribute to the development of more effective bioremediation strategies, but also have implications for a better understanding of bacterial movement in the subsurface as it relates to public health microbiology and general microbial ecology.

A fast field-cycling device for high-resolution NMR: Design and application to spin relaxation and hyperpolarization experiments

NASA Astrophysics Data System (ADS)

Kiryutin, Alexey S.; Pravdivtsev, Andrey N.; Ivanov, Konstantin L.; Grishin, Yuri A.; Vieth, Hans-Martin; Yurkovskaya, Alexandra V.

2016-02-01

A device for performing fast magnetic field-cycling NMR experiments is described. A key feature of this setup is that it combines fast switching of the external magnetic field and high-resolution NMR detection. The field-cycling method is based on precise mechanical positioning of the NMR probe with the mounted sample in the inhomogeneous fringe field of the spectrometer magnet. The device enables field variation over several decades (from 100 μT up to 7 T) within less than 0.3 s; progress in NMR probe design provides NMR linewidths of about 10-3 ppm. The experimental method is very versatile and enables site-specific studies of spin relaxation (NMRD, LLSs) and spin hyperpolarization (DNP, CIDNP, and SABRE) at variable magnetic field and at variable temperature. Experimental examples of such studies are demonstrated; advantages of the experimental method are described and existing challenges in the field are outlined.

Why does carbon increase in highly weathered soil under no-till upon lime and gypsum use?

PubMed

Inagaki, Thiago Massao; de Moraes Sá, João Carlos; Caires, Eduardo Fávero; Gonçalves, Daniel Ruiz Potma

2017-12-01

Field experiments have been used to explain how soil organic carbon (SOC) dynamics is affected by lime and gypsum applications, however, how SOC storage occurs is still debatable. We hypothesized that although many studies conclude that Ca-based soil amendments such as lime and gypsum may lead to SOC depletion due to the enhancement of microbial activity, the same does not occur under conservation agriculture conditions. Thus, the objective of this study was to elucidate the effects of lime and gypsum applications on soil microbial activity and SOC stocks in a no-till field and in a laboratory incubation study simulating no-till conditions. The field experiment was established in 1998 in a clayey Oxisol in southern Brazil following a completely randomized blocks design with a split-plot arrangement and three replications. Lime and gypsum were surface applied in 1998 and reapplied in 2013. Undisturbed soil samples were collected before the treatments reapplications, and one year after. The incubation experiment was carried out during 16months using these samples adding crop residues on the soil surface to simulate no-till field conditions. Lime and gypsum applications significantly increased the labile SOC stocks, microbial activity and soil fertility attributes in both field and laboratory experiments. Although the microbial activity was increased, no depletion of SOC stocks was observed in both experiments. Positive correlations were observed between microbial activity increase and SOC gains. Labile SOC and Ca 2+ content increase leads to forming complex with mineral soil fractions. Gypsum applications performed a higher influence on labile SOC pools in the field than in the laboratory experiment, which may be related to the presence of active root system in the soil profile. We conclude that incubation experiments using lime and gypsum in undisturbed samples confirm that soil microbial activity increase does not deplete SOC stocks under conservation agriculture. Copyright © 2017 Elsevier B.V. All rights reserved.

Role of International Study Experiences in the Personal and Professional Development of University Lecturers in the Humanities and Social Sciences Fields in Thailand

ERIC Educational Resources Information Center

Kaowiwattanakul, Sukanya

2016-01-01

This study investigates the role of international experience on personal and professional development of university academic staff in the Humanities and Social Sciences fields in Thailand. The participants were 23 lecturers from nine universities in Thailand. A semi-structured face-to-face interviewing method was employed. The findings reveal that…

IKONOS imagery for the Large Scale Biosphere–Atmosphere Experiment in Amazonia (LBA).

Treesearch

George Hurtt; Xiangming Xiao; Michael Keller; Michael Palace; Gregory P. Asner; Rob Braswell; Brond& #305; Eduardo S. zio; Manoel Cardoso; Claudio J.R. Carvalho; Matthew G. Fearon; Liane Guild; Steve Hagen; Scott Hetrick; Berrien Moore III; Carlos Nobre; Jane M. Read; S& aacute; Tatiana NO-VALUE; Annette Schloss; George Vourlitis; Albertus J. Wickel

2003-01-01

The LBA-ECO program is one of several international research components under the Brazilian-led Large Scale Biosphere–Atmosphere Experiment in Amazonia (LBA). The field-oriented research activities of this study are organized along transects and include a set of primary field sites, where the major objective is to study land-use change and ecosystem dynamics, and a...

Gravity field information from Gravity Probe-B

NASA Technical Reports Server (NTRS)

Smith, D. E.; Lerch, F. J.; Colombo, O. L.; Everitt, C. W. F.

1989-01-01

The Gravity Probe-B Mission will carry the Stanford Gyroscope relativity experiment into orbit in the mid 1990's, as well as a Global Positioning System (GPS) receiver whose tracking data will be used to study the earth gravity field. Estimates of the likely quality of a gravity field model to be derived from the GPS data are presented, and the significance of this experiment to geodesy and geophysics are discussed.

Studies on Plasmoid Merging using Compact Toroid Injectors

NASA Astrophysics Data System (ADS)

Allfrey, Ian; Matsumoto, Tadafumi; Roche, Thomas; Gota, Hiroshi; Edo, Takahiro; Asai, Tomohiko; Sheftman, Daniel; Osin Team; Dima Team

2017-10-01

C-2 and C-2U experiments have used magnetized coaxial plasma guns (MCPG) to inject compact toroids (CTs) for refueling the long-lived advanced beam-driven field-reversed configuration (FRC) plasma. This refueling method will also be used for the C-2W experiment. To minimize momentum transfer from the CT to the FRC two CTs are injected radially, diametrically opposed and coincident in time. To improve understanding of the CT characteristics TAE has a dedicated test bed for the development of CT injectors (CTI), where plasmoid merging experiments are performed. The test bed has two CTIs on axis with both axial and transverse magnetic fields. The 1 kG magnetic fields, intended to approximate the magnetic field strength and injection angle on C-2W, allow studies of cross-field transport and merging. Both CTIs are capable of injecting multiple CTs at up to 1 kHz. The resulting merged CT lives >100 μs with a radius of 25 cm. More detailed results of CT parameters will be presented.

Creating Dissonance in Pre-Service Teachers' Field Experiences

ERIC Educational Resources Information Center

Eisenhardt, Sara; Besnoy, Kevin; Steele, Emily

2012-01-01

The study is practical in nature and addresses the call for investigating effective aspects of field experiences in teacher preparation. The authors designed a framework of assignments requiring the pre-service teachers to collect data about two diverse elementary students in their assigned elementary classroom during the twelve weeks of their…

Developing the Effective Teaching Skills of Teacher Candidates during Early Field Experiences

ERIC Educational Resources Information Center

Welsh, Kelly A.; Schaffer, Connie

2017-01-01

This study examined the development of effective teaching skills in teacher candidates in the context of early field experiences directly tied to a pedagogical course. Evidence from faculty instructors, mentor teachers, and teacher candidates suggests secondary education candidates were able to develop effective teaching skills related to…

Practices of Cooperating Teachers Contributing to a High Quality Field Experience

ERIC Educational Resources Information Center

Lafferty, Karen Elizabeth

2015-01-01

This mixed methods study framed in cognitive apprenticeship theory involved cooperating and preservice teachers from 10 university-based credentialing programs in California. It examined the connection between cooperating teacher practices and preservice teachers' perceptions of a high quality field experience. Survey responses from 146…

Investigating the Impact of Field Trips on Teachers' Mathematical Problem Posing

ERIC Educational Resources Information Center

Courtney, Scott A.; Caniglia, Joanne; Singh, Rashmi

2014-01-01

This study examines the impact of field trip experiences on teachers' mathematical problem posing. Teachers from a large urban public school system in the Midwest participated in a professional development program that incorporated experiential learning with mathematical problem formulation experiences. During 2 weeks of summer 2011, 68 teachers…

Student Teachers' Team Teaching during Field Experiences: An Evaluation by Their Mentors

ERIC Educational Resources Information Center

Simons, Mathea; Baeten, Marlies

2016-01-01

Since collaboration within schools gains importance, teacher educators are looking for alternative models of field experience inspired by collaborative learning. Team teaching is such a model. This study explores two team teaching models (parallel and sequential teaching) by investigating the mentors' perspective. Semi-structured interviews were…

Optical investigation of effective permeability of dilute magnetic dielectrics with magnetic field

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

Banerjee, Ananya, E-mail: banerjee.ananya2008@gmail.com; Sarkar, A.

The prime objective of this paper is to investigate the magnetic nature of dilute magnetic dielectrics (DMD) under variation of external magnetic field. The said variation is studied over developed nano-sized Gadolinium Oxide as a DMD system. The observed experimental field variation of the effective magnetic permeability is analyzed results of optical experiment. The experiment records the variation of Brewster angle of incident polarized LASER beam from the surface of developed DMD specimen with applied out of plane external magnetic field. The effective refractive index and hence relative magnetic permeability were estimated following electro-magnetic theory. The overall results obtained andmore » agreement between theory and experiment are good.« less

Designing a Field Experience Tracking System in the Area of Special Education

ERIC Educational Resources Information Center

He, Wu; Watson, Silvana

2014-01-01

Purpose: To improve the quality of field experience, support field experience cooperation and streamline field experience management, the purpose of this paper is to describe the experience in using Activity Theory to design and develop a web-based field experience tracking system for a special education program. Design/methodology/approach: The…

Evaluation of Fast-Time Wake Models Using Denver 2006 Field Experiment Data

NASA Technical Reports Server (NTRS)

Ahmad, Nash’at N.; Pruis, Matthew J.

2015-01-01

The National Aeronautics and Space Administration conducted a series of wake vortex field experiments at Denver in 2003, 2005, and 2006. This paper describes the lidar wake vortex measurements and associated meteorological data collected during the 2006 deployment, and includes results of recent reprocessing of the lidar data using a new wake vortex algorithm and estimates of the atmospheric turbulence using a new algorithm to estimate eddy dissipation rate from the lidar data. The configuration and set-up of the 2006 field experiment allowed out-of-ground effect vortices to be tracked in lateral transport further than any previous campaign and thereby provides an opportunity to study long-lived wake vortices in moderate to low crosswinds. An evaluation of NASA's fast-time wake vortex transport and decay models using the dataset shows similar performance as previous studies using other field data.

Experimentally determined rock-fluid interactions applicable to a natural hot dry rock geothermal system

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

Charles, R.W.; Holley, C.E. Jr.; Tester, J.W.

1980-02-01

The Los Alamos Scientific Laboratory is pursuing laboratory and field experiments in the development of the Hot Dry Rock concept of geothermal energy. The field program consists of experiments in a hydraulically fractured region of low permeability in which hot rock is intercepted by two wellbores. These experiments are designed to test reservoir engineering parameters such as: heat extraction rates, water loss rates, flow characteristics including impedance and buoyancy, seismic activity and fluid chemistry. Laboratory experiments have been designed to provide information on the mineral reactivity which may be encountered in the field program. Two experimental circulation systems have beenmore » built to study the rates of dissolution and alteration in dynamic flow. Solubility studies have been done in agitated systems. To date, pure minerals, samples of the granodiorite from the actual reservoir and Tijeras Canyon granite have been reacted with distilled water and various solutions of NaCl, NaOH, and Na/sub 2/CO/sub 3/. The results of these experimental systems are compared to observations made in field experiments done in a hot dry rock reservoir at a depth of approximately 3 km with initial rock temperatures of 150 to 200/sup 0/C.« less

Semi-Numerical Studies of the Three-Meter Spherical Couette Experiment Utilizing Data Assimilation

NASA Astrophysics Data System (ADS)

Burnett, S. C.; Rojas, R.; Perevalov, A.; Lathrop, D. P.

2017-12-01

The model of the Earth's magnetic field has been investigated in recent years through experiments and numerical models. At the University of Maryland, experimental studies are implemented in a three-meter spherical Couette device filled with liquid sodium. The inner and outer spheres of this apparatus mimic the planet's inner core and core-mantle boundary, respectively. These experiments incorporate high velocity flows with Reynolds numbers 108. In spherical Couette geometry, the numerical scheme applied to this work features finite difference methods in the radial direction and pseudospectral spherical harmonic transforms elsewhere [Schaeffer, N. G3 (2013)]. Adding to the numerical model, data assimilation integrates the experimental outer-layer magnetic field measurements. This semi-numerical model can then be compared to the experimental results as well as forecasting magnetic field changes. Data assimilation makes it possible to get estimates of internal motions of the three-meter experiment that would otherwise be intrusive or impossible to obtain in experiments or too computationally expensive with a purely numerical code. If we can provide accurate models of the three-meter device, it is possible to attempt to model the geomagnetic field. We gratefully acknowledge the support of NSF Grant No. EAR1417148 & DGE1322106.

Semi-Numerical Studies of the Three-Meter Spherical Couette Experiment Utilizing Data Assimilation

NASA Astrophysics Data System (ADS)

Burnett, Sarah; Rojas, Ruben; Perevalov, Artur; Lathrop, Daniel; Ide, Kayo; Schaeffer, Nathanael

2017-11-01

The model of the Earth's magnetic field has been investigated in recent years through experiments and numerical models. At the University of Maryland, experimental studies are implemented in a three-meter spherical Couette device filled with liquid sodium. The inner and outer spheres of this apparatus mimic the planet's inner core and core-mantle boundary, respectively. These experiments incorporate high velocity flows with Reynolds numbers 108 . In spherical Couette geometry, the numerical scheme applied to this work features finite difference methods in the radial direction and pseudospectral spherical harmonic transforms elsewhere. Adding to the numerical model, data assimilation integrates the experimental outer-layer magnetic field measurements. This semi-numerical model can then be compared to the experimental results as well as forecasting magnetic field changes. Data assimilation makes it possible to get estimates of internal motions of the three-meter experiment that would otherwise be intrusive or impossible to obtain in experiments or too computationally expensive with a purely numerical code. If we can provide accurate models of the three-meter device, it is possible to attempt to model the geomagnetic field. We gratefully acknowledge the support of NSF Grant No. EAR1417148 & DGE1322106.

Space Magnets Attracting Interest on Earth: Applications of Physical and Biological Techniques In the Study of Gravisensing and Response System of Plants

NASA Technical Reports Server (NTRS)

Hasenstein, Karl H.; Boody, April; Cox, David (Technical Monitor)

2002-01-01

The BioTube/Magnetic Field Apparatus (MFA) research is designed to provide insight into the organization and operation of the gravity sensing systems of plants and other small organisms. This experiment on STS-107 uses magnetic fields to manipulate sensory cells in plant roots, thus using magnetic fields as a tool to study gravity-related phenomena. The experiment will be located in the SPACEHAB module and is about the size of a household microwave oven. The goal of the experiment is to improve our understanding of the basic phenomenon of how plants respond to gravity. The BioTube/MFA experiment specifically examines how gravitational forces serve as a directional signal for growth in the low-gravity environment of space. As with all basic research, this study will contribute to an improved understanding of how plants grow and will have important implications for improving plant growth and productivity on Earth. In BioTube/MFA, magnetic fields will be used to determine whether the distribution of subcellular starch grains, called amyloplasts, within plant cells predicts the direction in which roots will grow and curve in microgravity.

The joys of mapping: qualitative insights into the student experience of a residential geoscience field course

NASA Astrophysics Data System (ADS)

Stokes, Alison

2010-05-01

Using a mixed-format survey instrument, Boyle et al. (2007) identify significant effects in the affective domain resulting from participation in residential fieldwork. These findings are echoed by Stokes & Boyle (2009) in a separate, more detailed, study into the experiences of geoscience students when learning geologic mapping. While providing a quantifiable measure of changes in the students' attitudes and feelings, however, these survey data provide limited information about the experiences that have resulted in these changes, or of the factors likely to have influenced them. In order to gain a deeper insight into the students' affective responses, the quantitative data collected during this study were supplemented with qualitative data from in-situ and group interviews, open (free-text) survey questions, and direct observation of fieldwork activities. This provided a richness and depth of information that could not be achieved from quantitative data alone, and thus afforded a greater understanding of the students' experiences of this particular field activity. The survey findings showed that positive feelings and attitudes present at the start of the mapping field course became reinforced, but closer scrutiny of the data revealed that over half of the student cohort (57%) embarked on the fieldwork with some degree of worry, concern, or anxiety. The qualitative data enabled the source of these negative feelings to be identified, and provided evidence that these were overcome as a result of participating in the fieldwork. Thematic content analysis of the data resulted in the emergence of ten major themes; these provided a clear indication of factors significant to the student experience, and of specific aspects of the field course likely to generate either positive or negative affective responses. Further, these data highlighted the complexity of the learning process, and demonstrated the extent to which experiences varied between individual students. The social aspects of this field course emerged as being highly significant to the students' overall experience. The field is a social environment, and active participation in field activities enabled students to engage in social interactions with both their peers, and with ‘experts', e.g. academic and technical staff, and postgraduate students. Such interactions can be significant in shaping students' identities as geoscientists. In particular, they provide the opportunity to engage in shared experiences, through which students gain competency in subject specific skills and develop a vocabulary which is specific to the geoscience community. The unique socio-cultural setting in which this field course took place facilitated the continuation of these interactions outside of the field environment, and formed a vital component of the students' learning experience. The findings from this study broadly echo those from similar research undertaken at the same institution into residential field courses in geography and environmental science. While the locations, aims, and activities associated with these field courses vary, social and cultural aspects have consistently emerged as important and valued aspects of students' experience of undergraduate fieldwork. This appears to be an area of research that is somewhat overlooked, and one which merits further investigation.

Perspectives of Turkish Intern and Non-Intern Students towards Sport Management Internship within the Context of Field Experience

ERIC Educational Resources Information Center

Coknaz, Dilsad

2014-01-01

The purpose of this study was to examine differences between intern and non-intern students in terms of their perspectives on sport management internship within the context of field experience. The subjects of the study were a total of 189 students. They were 4th year students who completed their internship and 3rd year students who were yet to…

Field Instructors' Perspectives on Foundation Year MSW Students' Preplacement Anxiety

ERIC Educational Resources Information Center

Rosenthal Gelman, Caroline

2011-01-01

This study elicited 39 field instructors' perspectives on the anxiety that students experience as they begin field placements. Field instructors rated students as significantly more anxious than did students themselves, and although field instructors believed anxiety interferes with learning to a greater extent than did students, they did not…

High magnetic field behavior of NbFe2

NASA Astrophysics Data System (ADS)

Rauch, D.; Steinki, N.; Knafo, W.; Pfleiderer, C.; Duncan, W. J.; Grosche, F. M.; Süllow, S.

2018-05-01

We have carried out a high magnetic field study on single crystalline stoichiometric NbFe2, a material discussed in terms quantum criticality in itinerant ferromagnets, by means of high field resistivity experiments. Our experiments have been performed at the Laboratoire National des Champs Magnétiques Intenses in Toulouse, France. The resistivity of single crystalline NbFe2, has been investigated in external fields up to 15.5 T aligned along the c-axis in the temperature range of 1.4-55 K. The main focus of our study lies on the method to extract TN from the magnetoresistivity measurements, because TN could not be easily observed in temperature dependent resistivity for stoichiometric NbFe2.

Experimental Investigation of the Effects of an Axial Magnetic Field on the Magneto-Rayleigh-Taylor Instability in Ablating Planar Foils

NASA Astrophysics Data System (ADS)

Yager-Elorriaga, D. A.; Patel, S. G.; Steiner, A. M.; Jordan, N. M.; Weiss, M. R.; Gilgenbach, R. M.; Lau, Y. Y.

2014-10-01

Experiments are underway to study the effects an axial magnetic field on the magneto-Rayleigh-Taylor instability (MRT) in ablating planar foils on the 1-MA LTD at the Michigan Accelerator for Inductive Z-pinch Experiments (MAIZE) facility at the University of Michigan. For 600 kA drive current, a 15 T axial magnetic field is produced using helical return current posts. During the current pulse, the magnetic field may diffuse into the foil, creating a sheared magnetic field along with the possibility of shear stabilization of the MRT instability. Theoretical investigation at UM has shown that a sheared azimuthal magnetic field coupled with an axial magnetic field reduces the MRT growth rate in general. In order to study this effect, the amount of magnetic shear is controlled by offsetting the initial position of the foil. A 775 nm Ti:sapphire laser will be used to shadowgraph the foil in order to measure the MRT growth rate. By comparing these results to previous experiments at UM, the effects of magnetic shear and an axial magnetic field will be determined. This work was supported by US DoE. S.G. Patel and A.M. Steiner supported by NPSC funded by Sandia. D.A. Yager-Elorriaga supported by NSF fellowship Grant DGE 1256260.

When Pleasure and Pain Take the Field: The Experience of the Body in Female Collegiate Athletes

ERIC Educational Resources Information Center

Ghidinelli, Kate

2013-01-01

This study examined the subjective experiences of training and competition at the collegiate level in a small group of former Division I female collegiate athletes. A review of relevant research indicates there is a dearth of qualitative studies on the experiences of female collegiate athletes. The current study explored the experience of pushing…

Aha Malawi! Envisioning Field Experiences That Nurture Cultural Competencies for Preservice Teachers

ERIC Educational Resources Information Center

Talbot, Patricia A.

2011-01-01

This theoretical study uses the context of the writer's personal encounters in Malawi, Africa, to propose a conceptual model for creating diverse field experiences based on best practices in critical pedagogy, service learning, and the underpinnings of transformational learning theory, for the purpose of increasing the probability of meaningful…

Fostering Preservice Teachers' Development: Engagement in Practice and Learning

ERIC Educational Resources Information Center

McMahan, Sarah K.; Garza, Rubén

2017-01-01

Given the benefits associated with authentic field experiences (Edwards, 1996; McMahan et al., 2015; Siwatu, 2010), it is not uncommon to include early field experiences prior to student teaching as a way to engage university students with teaching diverse students in an authentic school setting. This study explored preservice teachers'…

Preservice Students' Attitudes toward Pupil Control as They Develop throughout the Field Experiences.

ERIC Educational Resources Information Center

Killian, Joyce E.; McIntyre, D. John

This study used repeated measures of the Pupil Control Ideology (PCI) instrument to examine the change in student teacher orientation toward pupil control ideology occurring during a three semester field experience. The instrument was given to elementary and secondary education majors at Southern Illinois University at Carbondale five different…

The Impact of a Social Justice Service-Learning Field Experience in a Social Foundations Course

ERIC Educational Resources Information Center

Tinkler, Barri; hannah, c. lynne; Tinkler, Alan; Miller, Elizabeth

2015-01-01

This interpretive study examines the outcomes of using a social justice service-learning field experience in a social foundations course to help illuminate for teacher candidates the often "invisible" institutionalized inequities of public schools. The findings demonstrate how social justice service-learning can be used as a field…

Building Connections: An Interpretative Phenomenological Analysis of Qualitative Research Students' Learning Experiences

ERIC Educational Resources Information Center

Cooper, Robin; Fleischer, Anne; Cotton, Fatima A.

2012-01-01

This paper describes a phenomenological study in which the authors explored students' experiences learning qualitative research in a variety of academic fields. Semi-structured in-depth interviews were conducted with six participants from various academic fields who had completed at least one post-secondary-school-level qualitative research course…

Rational Ignorance in Education: A Field Experiment in Student Plagiarism

ERIC Educational Resources Information Center

Dee, Thomas S.; Jacob, Brian A.

2012-01-01

Plagiarism appears to be a common problem among college students, yet there is little evidence on the effectiveness of interventions designed to minimize plagiarism. This study presents the results of a field experiment that evaluated the effects of a web-based educational tutorial in reducing plagiarism. We found that assignment to the treatment…

A Study of Guided Urban Field Experiences for Pre-Service Teachers

ERIC Educational Resources Information Center

White, Meg

2017-01-01

This research examined pre-service teachers' perceptions of urban schools and urban students before and after an 80-hour field experience in an urban K-12 district. The fieldwork placements were structured through a school-university partnership, and supported by university coursework. Quantitative data collected from 150 students over three…

Cognitive Learning Strategy as a Partial Effect on Major Field Test in Business Results

ERIC Educational Resources Information Center

Strang, Kenneth David

2014-01-01

An experiment was developed to determine if cognitive learning strategies improved standardized university business exam results. Previous studies revealed that factors such as prior ability, age, gender, and culture predicted a student's Major Field Test in Business (MFTB) score better than course content. The experiment control consisted of…

Nurses' experiences of ethnographic fieldwork.

PubMed

de Melo, Lucas Pereira; Stofel, Natália Sevilha; Gualda, Dulce Maria Rosa; de Campos, Edemilson Antunes

2014-09-01

To reflect on the experiences of nurses performing ethnographic fieldwork in three studies. The application of ethnography to nursing research requires discussion about nurses' experiences of ethnographic fieldwork. This article examines some of the dilemmas that arise during the research process. Three ethnographic studies conducted by the authors in the south and southeast of Brazil. Excerpts from field diaries created during each research are presented at the end of each topic discussed. This is a reflexive paper that explores the nurses' experience in ethnographic fieldwork. This article discusses the main tasks involved in ethnographic research, including defining the study aim, reading and understanding anthropological theoretical bases, and setting a timeframe for the study. The article also discusses the idiosyncrasies of the cultural contexts studied, the bureaucracy that may be confronted when gaining access to the field, the difficulty of transforming the familiar into the strange, why ethnocentric perspectives should be avoided, and the anthropological doubt that places the ethnographer in the position of apprentice. It also discusses the importance of listening to others, reflexivity and strategies to stay in the field. For researchers, ethnographic fieldwork can be a rite of passage, but one that provides invaluable experiences that emphasise the value of relationships based on dialogue, reflexivity and negotiation. The main tasks undertaken in ethnographic research discussed in this article could contribute to the nurse' experience of conducting ethnographic fieldwork.

Gender Differences in the Field of Information Security Technology Management: A Qualitative, Phenomenological Study

ERIC Educational Resources Information Center

Johnson, Marcia L.

2013-01-01

This qualitative study explored why there are so few senior women in the information security technology management field and whether gender played a part in the achievement of women in the field. Extensive interviews were performed to capture the lived experiences of successful women in the field regarding the obstacles and common denominators of…

Field Placement Treatments: A Comparative Study

ERIC Educational Resources Information Center

Parkison, Paul T.

2008-01-01

Field placement within teacher education represents a topic of interest for all preservice teacher programs. Present research addresses a set of important questions regarding field placement: (1) What pedagogical methodologies facilitate deep learning during field experiences? (2) Is there a significant difference in treatment effect for…

Computer aided field editing in the DHS context: the Turkey experiment.

PubMed

Cushing, J; Loaiza, E

1994-01-01

"In this study two types of field editing used during the Turkey Demographic and Health Survey are compared. These two types of editing are computer aided field editing and manual editing. It is known that manual editing by field editors is a tedious job in which errors especially on skip questions can be missed; however, with the aid of computers field editors could quickly find all occasions on which an interviewer incorrectly followed a skip instruction. At the end of the experiment it has been found...that the field editing done with the aid of a notebook computer was consistently better than that done in the standard manual manner." (SUMMARY IN TUR) excerpt

Using Magnetic Field Gradients to Simulate Variable Gravity in Fluids and Materials Experiments

NASA Technical Reports Server (NTRS)

Ramachandran, Narayanan

2006-01-01

Fluid flow due to a gravitational field is caused by sedimentation, thermal buoyancy, or solutal buoyancy induced convection. During crystal growth, for example, these flows are undesirable and can lead to crystal imperfections. While crystallization in microgravity can approach diffusion limited growth conditions (no convection), terrestrially strong magnetic fields can be used to control fluid flow and sedimentation effects. In this work, a theory is presented on the stability of solutal convection of a magnetized fluid(weak1y paramagnetic) in the presence of a magnetic field. The requirements for stability are developed and compared to experiments performed within the bore of a superconducting magnet. The theoretical predictions are in good agreement with the experiments. Extension of the technique can also be applied to study artificial gravity requirements for long duration exploration missions. Discussion of this application with preliminary experiments and application of the technique to crystal growth will be provided.

A Mapping Model for Magnetic Fields with q-profile Variations Typical of Internal Transport Barrier Experiments

NASA Astrophysics Data System (ADS)

Rapoport, B. I.; Pavlenko, I.; Weyssow, B.; Carati, D.

2002-11-01

Recent studies of ion and electron transport indicate that the safety factor profile, q(r), affects internal transport barrier (ITB) formation in magnetic confinement devices [1, 2]. These studies are consistent with experimental observations that low shear suppresses magnetic island interaction and associated stochasticity when the ITB is formed [3]. In this sense the position and quality of the ITB depend on the stochasticity of the magnetic field, and can be controlled by q(r). This study explores effects of the q-profile on magnetic field stochasticity using two-dimensional mapping techniques. Q-profiles typical of ITB experiments are incorporated into Hamiltonian maps to investigate the relation between magnetic field stochasticity and ITB parameters predicted by other models. It is shown that the mapping technique generates results consistent with these predictions, and suggested that Hamiltonian mappings can be useful as simple and computationally inexpensive approximation methods for describing the magnetic field in ITB experiments. 1. I. Voitsekhovitch et al. 29th EPS Conference on Plasma Physics and Controlled Fusion (2002). O-4.04. 2. G.M.D. Hogeweij et al. Nucl. Fusion. 38 (1998): 1881. 3. K.A. Razumova et al. Plasma Phys. Contr. Fusion. 42 (2000): 973.

Field and Experience Influences on Ethical Decision-Making in the Sciences

PubMed Central

Mumford, Michael D.; Connelly, Shane; Murphy, Stephen T.; Devenport, Lynn D.; Antes, Alison L.; Brown, Ryan P.; Hill, Jason H.; Waples, Ethan P.

2009-01-01

Differences across fields and experience levels are frequently considered in discussions of ethical decision-making and ethical behavior. In the present study, doctoral students in the health, biological, and social sciences completed measures of ethical decision-making. The effects of field and level of experience with respect to ethical decision-making, metacognitive reasoning strategies, social-behavioral responses, and exposure to unethical events were examined. Social and biological scientists performed better than health scientists with respect to ethical decision-making. Furthermore, the ethical decision-making of health science students decreased as experience increased. Moreover, these effects appeared to be linked to the specific strategies underlying participants' ethical decision-making. The implications of these findings for ethical decision-making are discussed. PMID:19750129

Field versus laboratory experiments to evaluate the fate of azoxystrobin in an amended vineyard soil.

PubMed

Herrero-Hernández, E; Marín-Benito, J M; Andrades, M S; Sánchez-Martín, M J; Rodríguez-Cruz, M S

2015-11-01

This study reports the effect that adding spent mushroom substrate (SMS) to a representative vineyard soil from La Rioja region (Spain) has on the behaviour of azoxystrobin in two different environmental scenarios. Field dissipation experiments were conducted on experimental plots amended at rates of 50 and 150 t ha(-1), and similar dissipation experiments were simultaneously conducted in the laboratory to identify differences under controlled conditions. Azoxystrobin dissipation followed biphasic kinetics in both scenarios, although the initial dissipation phase was much faster in the field than in the laboratory experiments, and the half-life (DT50) values obtained in the two experiments were 0.34-46.3 days and 89.2-148 days, respectively. Fungicide residues in the soil profile increased in the SMS amended soil and they were much higher in the top two layers (0-20 cm) than in deeper layers. The persistence of fungicide in the soil profile is consistent with changes in azoxystrobin adsorption by unamended and amended soils over time. Changes in the dehydrogenase activity (DHA) of soils under different treatments assayed in the field and in the laboratory indicated that SMS and the fungicide had a stimulatory effect on soil DHA. The results reveal that the laboratory studies usually reported in the literature to explain the fate of pesticides in amended soils are insufficient to explain azoxystrobin behaviour under real conditions. Field studies are necessary to set up efficient applications of SMS and fungicide, with a view to preventing the possible risk of water contamination. Copyright © 2015 Elsevier Ltd. All rights reserved.

Spatial Distribution of Phase Singularities in Optical Random Vector Waves.

PubMed

De Angelis, L; Alpeggiani, F; Di Falco, A; Kuipers, L

2016-08-26

Phase singularities are dislocations widely studied in optical fields as well as in other areas of physics. With experiment and theory we show that the vectorial nature of light affects the spatial distribution of phase singularities in random light fields. While in scalar random waves phase singularities exhibit spatial distributions reminiscent of particles in isotropic liquids, in vector fields their distribution for the different vector components becomes anisotropic due to the direct relation between propagation and field direction. By incorporating this relation in the theory for scalar fields by Berry and Dennis [Proc. R. Soc. A 456, 2059 (2000)], we quantitatively describe our experiments.

Junior physicians' workplace experiences in clinical fields in German-speaking Switzerland.

PubMed

Buddeberg-Fischer, Barbara; Klaghofer, Richard; Abel, Thomas; Buddeberg, Claus

2005-01-08

To date, there have been several prospective cohort studies investigating the workplace experiences of junior physicians, but with limited focus on gender issues. The objective of the present study is to explore the workplace experiences of first-year residents according to gender, type of training hospital, and clinical field. Data reported are from the second assessment of the longitudinal Swiss physicians' career development study, begun in 2001. In 2003, 497 residents (54.7% females, 45.3% males) assessed their workplace conditions, social support at work, and effort-reward imbalance. There are few, but relevant, gender related differences in workplace experiences, with female physicians experiencing less mentoring and higher over-commitment, yet more positive social relationships at work. In a multivariate model, significant differences in some workplace variables with regard to type of training hospital and/or clinical field are found: workplace conditions are rated worse in type "A" hospitals (university and cantonal hospitals) than in type "B"/"C"/"D" hospitals (regional hospitals and highly specialised units), and in surgical fields than in internal medicine. In "A" hospitals mentoring is assessed as better, but positive social relationships as worse. Both scales are rated worse in surgical fields than in internal medicine. The effort-reward imbalance (ERI) is rated significantly higher (unfavourable) in "A" hospitals than in "B"/"C"/"D" hospitals, regardless of gender and clinical field. Significantly more subjects with an ERI quotient above 1 (which is unfavourable) work in "A" hospitals, and in surgical fields regardless of hospital type. Of the total sample, 81 subjects (16.3%), 41 males and 40 females, show an ERI quotient above 1. The greater the workload, the worse the rating of workplace conditions, effort-reward imbalance, and over-commitment. Institutional determinants are crucial factors for the workplace experiences and first career steps of junior physicians. Medical educators, especially those in "A" hospitals, should become more involved in structured residency programs and be aware of potential gender inequalities in the career support of female physicians.

Combining sprinkling experiments and superconducting gravimetry in the field: a qualitative approach to identify dominant infiltration patterns

NASA Astrophysics Data System (ADS)

Reich, Marvin; Mikolaj, Michal; Blume, Theresa; Güntner, Andreas

2017-04-01

Hydrological process research at the plot to catchment scale commonly involves invasive field methods, leading to a large amount of point data. A promising alternative, which gained increasing interest in the hydrological community over the last years, is gravimetry. The combination of its non-invasive and integrative nature opens up new possibilities to approach hydrological process research. In this study we combine a field-scale sprinkling experiment with continuous superconducting gravity (SG) measurements. The experimental design consists of 8 sprinkler units, arranged symmetrically within a radius of about ten meters around an iGrav (SG) in a field enclosure. The gravity signal of the infiltrating sprinkling water is analyzed using a simple 3D water mass distribution model. We first conducted a number of virtual sprinkling experiments resulting in different idealized infiltration patterns and determined the pattern specific gravity response. In a next step we determined which combination of idealized infiltration patterns was able to reproduce the gravity response of our real-world experiment at the Wettzell Observatory (Germany). This process hypothesis is then evaluated with measured point-scale soil moisture responses and the results of the time-lapse electric resistivity survey which was carried out during the sprinkling experiment. This study demonstrates that a controlled sprinkling experiment around a gravimeter in combination with a simple infiltration model is sufficient to identify subsurface flow patterns and thus the dominant infiltration processes. As gravimeters become more portable and can actually be deployed in the field, their combination with sprinkling experiments as shown here constitutes a promising possibility to investigate hydrological processes in a non-invasive way.

Evaluation of the Persistent Issues in History Laboratory for Virtual Field Experience (PIH-LVFE)

ERIC Educational Resources Information Center

Brush, Thomas; Saye, John; Kale, Ugur; Hur, Jung Won; Kohlmeier, Jada; Yerasimou, Theano; Guo, Lijiang; Symonette, Simone

2009-01-01

The Persistent Issues in History Laboratory for Virtual Field Experience (PIH-LVFE) combines a database of video cases of authentic classroom practices with multiple resources and tools to enable pre-service social studies teachers to virtually observe teachers implementing problem-based learning activities. In this paper, we present the results…

Foundational Field Experiences: A Window into Preservice Teachers' Cultural Consciousness and Self-Efficacy for Teaching Diverse Learners

ERIC Educational Resources Information Center

Lastrapes, Wanda; Negishi, Meiko

2012-01-01

This study examined preservice teachers' cultural consciousness and self-efficacy while tutoring diverse students during an initial urban field experience. The 46 participants, enrolled in an introduction to diversity course, completed an 18-hour tutoring requirement in elementary and secondary schools. Paired-sample t-tests yielded statistically…

The Impact of Field Experiences on the Competencies and Attitudes of Prospective Social Studies Teachers.

ERIC Educational Resources Information Center

Lux, John E.

This document reports on a project designed to determine whether the amount and type of field experiences of students prior to student teaching would influence the achievement of competencies and result in different instructional patterns and attitudes of prospective teachers. Important subquestions were whether it was desirable to provide basic…

The Effects of College Major and Job Field Congruence on Job Satisfaction

ERIC Educational Resources Information Center

Wolniak, Gregory C.; Pascarella, Ernest T.

2005-01-01

This study investigated predictors of job satisfaction and builds on previous research on the effects of bachelor's degree majors and job field congruence on job satisfaction. Data on workers' job experiences in 2001 were matched to those workers' college experiences across 30 institutions and background characteristics up to 25 years earlier.…

An Investigation into the Contents and Aspects of College Students' Reflective Thoughts during Field Experience

ERIC Educational Resources Information Center

Su, Yuling

2015-01-01

Field experience makes a strong contribution to the learning of students. However, the procedure for conducting training sessions based on experiential teaching methods is relatively unclear, and the contents and aspects of students' reflections during such training are not well known. This study applied experiential teaching methods in a college…

Innovative Field Experiences in Teacher Education: Student-Teachers and Mentors as Partners in Teaching

ERIC Educational Resources Information Center

Baeten, Marlies; Simons, Mathea

2016-01-01

This study investigates team teaching between student teachers and mentors during student teachers' field experiences. A systematic literature search was conducted, which resulted into a narrative review. Three team teaching models could be distinguished: (1) the co-planning and co-evaluation model, (2) the assistant teaching model, and (3) the…

Hemispheric Specialization for Language According to Grapho-Phonemic Transformation and Gender. A Divided Visual Field Experiment

ERIC Educational Resources Information Center

Cousin, Emilie; Perrone, Marcela; Baciu, Monica

2009-01-01

This behavioral study aimed at assessing the effect of two variables on the degree of hemispheric specialization for language. One of them was the "grapho-phonemic translation (transformation)" (letter-sound mapping) and the other was the participants' "gender". The experiment was conducted with healthy volunteers. A divided visual field procedure…

Seeing What They See--A Photovoice Analysis of Exploratory Early Field Experiences

ERIC Educational Resources Information Center

Baker, Marshall A.; Culbertson, Avery L.; Robinson, J. Shane; Ramsey, Jon W.

2017-01-01

The purpose of this photovoice study was to investigate what and how pre-service teachers conceive and make meaning of exploration observations of early field experiences (EFEs). EFEs are vital components of the teacher preparation program and include all activities that occur in pre-service teacher education prior to student teaching, including…

The Success and Struggles of Filipino Geriatric Nurses in Nursing Homes

ERIC Educational Resources Information Center

de Guzman, Allan B.; Coronel, Rona Denise V.; Chua, Kannerin O.; Constantino, Mariz G.; Cordova, Ericsann James C.

2009-01-01

Geriatric nursing is a physically and emotionally demanding job in healthcare. It is a neglected field despite the growing population of the elderly, and the experiences of geriatric nurses are one of the unrecognized aspects of this field. This qualitative study purports to explore the successes and struggles of the lived experiences of a select…

Do Differing Types of Field Experiences Make a Difference in Teacher Candidates' Perceived Level of Competence?

ERIC Educational Resources Information Center

Caprano, Mary Margaret; Caprano, Robert M.; Helfeldt, Jack

2010-01-01

Little research has been conducted to directly compare the effectiveness of different models of field-based learning experiences and little has been reported on the use of the Interstate New Teacher Assessment and Support Consortium (INTASC) standards in establishing a formative assessment for teacher candidates (TCs). The current study used the…

Cryogen-free superconducting magnet system for multifrequency electron paramagnetic resonance up to 12.1 T

NASA Astrophysics Data System (ADS)

Smirnov, Alex I.; Smirnova, Tatyana I.; MacArthur, Ryan L.; Good, Jeremy A.; Hall, Renny

2006-03-01

Multifrequency and high field/high frequency (HF) electron paramagnetic resonance (EPR) is a powerful spectroscopy for studying paramagnetic spin systems ranging from organic-free radicals to catalytic paramagnetic metal ion centers in metalloproteins. Typically, HF EPR experiments are carried out at resonant frequencies ν =95-300GHz and this requires magnetic fields of 3.4-10.7T for electronic spins with g ≈2.0. Such fields could be easily achieved with superconducting magnets, but, unlike NMR, these magnets cannot operate in a persistent mode in order to satisfy a wide range of resonant fields required by the experiment. Operating and maintaining conventional passively cooled superconducting magnets in EPR laboratories require frequent transfer of cryogens by trained personnel. Here we describe and characterize a versatile cryogen-free magnet system for HF EPR at magnetic fields up to 12.1T that is suitable for ramping the magnetic field over the entire range, precision scans around the target field, and/or holding the field at the target value. We also demonstrate that in a nonpersistent mode of operation the magnetic field can be stabilized to better than 0.3ppm/h over 15h period by employing a transducer-controlled power supply. Such stability is sufficient for many HF EPR experiments. An important feature of the system is that it is virtually maintenance-free because it is based on a cryogen-free technology and therefore does not require any liquid cryogens (liquid helium or nitrogen) for operation. We believe that actively cooled superconducting magnets are ideally suited for a wide range of HF EPR experiments including studies of spin-labeled nucleic acids and proteins, single-molecule magnets, and metalloproteins.

Emerging: An Art Field Placement's Impact on Practice

ERIC Educational Resources Information Center

Averett, Paige; Spence, Christina Hall

2018-01-01

This exploratory study examined the experiences of 9 stakeholders in an art gallery field placement during their social work education. The study sought to understand how the nontraditional field placement prepared students for practice. In addition, personality traits of students that best fit the placement was examined. Findings suggest that…

Summary of the Madison Dynamo Experiment

NASA Astrophysics Data System (ADS)

Kendrick, R. D.; Spence, E. J.; Nornberg, M. D.; Forest, C. B.

2001-10-01

A spherical dynamo experiment has been constructed at the University of Wisconsin's liquid sodium facility. The goals of the experiment are to observe and understand magnetic instabilities driven by flow shear in MHD systems, investigate MHD turbulence for magnetic Reynolds numbers of ~100, and understand the role of fluid turbulence in current generation. Magnetic field generation is possible for only specific flow geometries. We have studied and achieved simple roll flow geometries in a full scale water experiment. Results from this experiment have guided the design of the sodium experiment. The experiment consists of a 1 m diameter, spherical stainless steel vessel filled with liquid sodium at 110 Celsius. Two 100 Hp motors with impellers drive flows in the liquid sodium with flow velocities ~ 15 m/s. A gaussian grid of Hall probes on the surface of the sodium vessel measure the generated external magnetic field. Hall probe feed-thru arrays measure the internal field. Preliminary investigations include measurements of the turbulent electromotive force and excitation of magnetic eigenmodes.

Design of the Madison Dynamo Experiment

NASA Astrophysics Data System (ADS)

Kendrick, R. D.; Bayliss, R. A.; Forest, C. B.; Nornberg, M. D.; O'Connell, R.; Spence, E. J.

2003-10-01

A spherical dynamo experiment has been constructed at the University of Wisconsin's liquid sodium facility. The goals of the experiment are to observe and understand magnetic instabilities driven by flow shear in MHD systems, investigate MHD turbulence for magnetic Reynolds numbers of ˜100, and understand the role of fluid turbulence in current generation. Magnetic field generation is possible for only specific flow geometries. We have studied and achieved simple roll flow geometries in a full scale water experiment. Results from this experiment have guided the design of the sodium experiment. The experiment consists of a 1 m diameter, spherical stainless steel vessel filled with liquid sodium at 110 Celsius. Two 100 Hp motors with impellers drive flows in the liquid sodium with flow velocities ˜ 15 m/s. A grid of Hall probes on the surface of the sodium vessel measure the generated external magnetic field. Hall probe feed-thru arrays measure the internal field. Preliminary investigations include measurements of the turbulent electromotive force and excitation of magnetic eigenmodes.

Experimental realization of dynamo action: present status and prospects

NASA Astrophysics Data System (ADS)

Giesecke, André; Stefani, Frank; Gundrum, Thomas; Gerbeth, Gunter; Nore, Caroline; Léorat, Jacques

2013-07-01

In the last decades, the experimental study of dynamo action has made great progress. However, after the dynamo experiments in Karlsruhe and Riga, the von-Kármán-Sodium (VKS) dynamo is only the third facility that has been able to demonstrate fluid flow driven self-generation of magnetic fields in a laboratory experiment. Further progress in the experimental examination of dynamo action is expected from the planned precession driven dynamo experiment that will be designed in the framework of the liquid sodium facility DRESDYN (DREsden Sodium facility for DYNamo and thermohydraulic studies). In this paper, we briefly present numerical models of the VKS dynamo that demonstrate the close relation between the axisymmetric field observed in that experiment and the soft iron material used for the flow driving impellers. We further show recent results of preparatory water experiments and design studies related to the precession dynamo and delineate the scientific prospects for the final set-up.

Evidence, explanations, and recommendations for teachers' field trip strategies

NASA Astrophysics Data System (ADS)

Rebar, Bryan

Field trips are well recognized by researchers as an educational approach with the potential to complement and enhance classroom science teaching by exposing students to unique activities, resources, and content in informal settings. The following investigation addresses teachers' field trip practices in three related manuscripts: (1) A study examining the details of teachers' pedagogical strategies intended to facilitate connections between students' experiences and the school curricula while visiting an aquarium; (2) A study documenting and describing sources of knowledge that teachers draw from when leading field trips to an aquarium; (3) A position paper that reviews and summarizes research on effective pedagogical strategies for field trips. Together these three pieces address key questions regarding teachers' practices on field trips: (1) What strategies are teachers employing (and not employing) during self-guided field trips to facilitate learning tied to the class curriculum? (2) What sources of knowledge do teachers utilize when leading field trips? (3) How can teachers be better prepared to lead trips that promote learning? The Oregon Coast Aquarium served as the field trip site for teachers included in this study. The setting suited these questions because the aquarium serves tens of thousands of students on field trips each year but provides no targeted programming for these students as they explore the exhibits. In other words, the teachers who lead field trips assume much of the responsibility for facilitating students' experience. In order to describe and characterize teachers' strategies to link students' experiences to the curriculum, a number of teachers (26) were observed as they led their students' visit to the public spaces of the aquarium. Artifacts, such as worksheets, used during the visit were collected for analysis as well. Subsequently, all teachers were surveyed regarding their use of the field trip and their sources of knowledge for their practices. A subset of eight teachers were interviewed using guided conversations in order to shed further light on their use of the aquarium field trip and their pedagogical preparation. Data from all sources were organized by repeating ideas relevant to the questions of interest. The resulting evidence was interpreted to support distinct categories of teacher strategies and experience and related claims about these strategies and experiences. Thus, findings reveal that teachers attempt to link the curriculum to the activities, resources, and content encountered on the trip using a variety of connections. However, these curriculum connections are characterized as products of opportunistic situations and reveal limited depth. Evidence further indicates that teachers treat the aquarium visit as a background experience for their students rather than as an opportunity to introduce new concepts or do an activity that is integrated into the curriculum. Nevertheless, teachers included in this study were leading field trips that created countless learning opportunities for their students. Because training specific to field trips is rarely included in preservice programs, teachers were asked about influences on their field trip practice with specific focus on observed strategies. Findings suggest four categories of training experiences that teachers apply to their practice: (1) informal mentoring; (2) past experience trip leading; (3) outdoor education training; (4) traditional education training. Overall findings along with a review of previous research are suggestive of many ways in which efforts to enhance students' learning opportunities may be developed by means of support for teachers. Foremost among recommendations is the idea that field trip pedagogy be integrated into science methods courses required for preservice teachers (the premise for the final manuscript). Furthermore, the findings of this study may serve as a starting point for museums interested in the development of specific support and teacher professional development activities intended to enhance teachers' use of their resources as learning opportunities for their students. Among the implications is the idea that museums and other institutions developing teacher professional development activities might capitalize on teachers' existing sources of knowledge, for example by providing structured support for peer-mentoring and guided reflections related to field trip preparations and skills.

Hooking the Geographer in Children with Field-Based Studies

ERIC Educational Resources Information Center

Krall, Florence; And Others

1978-01-01

Suggests projects to help elementary students learn about man-land relationships through field experience, inquiry techniques, and a thematic, interdisciplinary approach. Children study a natural community, a human community, solid wastes, and energy conservation. (Author/AV)

Assessing the changes in E. coli levels and nutrient dynamics during vermicomposting of food waste under lab and field scale conditions.

PubMed

Cao, Wenlong; Vaddella, Venkata; Biswas, Sagor; Perkins, Katherine; Clay, Cameron; Wu, Tong; Zheng, Yawen; Ndegwa, Pius; Pandey, Pramod

2016-11-01

Vermicomposting (VC) has proven to be a promising method for treating garden, household, and municipal wastes. Although the VC has been used extensively for converting wastes into fertilizers, pathogens such as Escherichia coli (E. coli) survival during this process is not well documented. In this study, both lab and field scale experiments were conducted assessing the impacts of earthworms in reducing E. coli concentration during VC of food waste. In addition, other pertinent parameters such as temperature, carbon and nitrogen content, moisture content, pH, volatile solids, micronutrients (P, K, Ca, Mg, and S), and heavy metals (Zn, Mn, Fe, and Cu) were monitored during the study. The lab and field scale experiments were conducted for 107 and 103 days, respectively. The carbon to nitrogen ratio (C/N) decreased by 54 % in the lab scale study and by 36 % in the field study. Results showed that VC was not significantly effective in reducing E. coli levels in food waste under both lab and field scale settings. The carbon to nitrogen ratio (C/N) decreased by 54 % in the lab scale study and by 36 % in the field study.

The development of laser speckle velocimetry for the study of vortical flows

NASA Technical Reports Server (NTRS)

Krothapalli, A.

1991-01-01

A research program was undertaken to develop a new experimental technique commonly known as particle image displacement velocity (PIVD) to measure an instantaneous two dimensional velocity field in a selected plane of flow field. This technique was successfully developed and applied to the study of several aerodynamic problems. A detailed description of the technique and a broad review of all the research activity carried out in this field are reported. A list of technical publications is also provided. The application of PIDV to unsteady flows with large scale structures is demonstrated in a study of the temporal evolution of the flow past an impulsively started circular cylinder. The instantaneous two dimensional flow in the transition region of a rectangular air jet was measured using PIDV and the details are presented. This experiment clearly demonstrates the PIDV capability in the measurement of turbulent flows. Preliminary experiments were also conducted to measure the instantaneous flow over a circular bump in a transonic flow. Several other experiments now routinely use PIDV as a non-intrustive measurement technique to obtain instantaneous two dimensional velocity fields.

A Biomes Field Trip.

ERIC Educational Resources Information Center

Leonard, William H.; And Others

1983-01-01

Describes a field trip designed to give students opportunities to experience relevant data leading to concepts in biogeography. Suggests that teachers (including college instructors) adapt the areas studied and procedures used to their own locations. Includes a suggested field trip handout. (JN)

Considering Student Voices: Examining the Experiences of Underrepresented Students in Intervention Programs

ERIC Educational Resources Information Center

Gibau, Gina Sanchez

2015-01-01

Qualitative studies that examine the experiences of underrepresented minority students in science, technology, engineering, and mathematics fields are comparatively few. This study explores the self-reported experiences of underrepresented graduate students in the biomedical sciences of a large, midwestern, urban university. Document analysis of…

Comparison of wind tunnel and field experiments to measure potential deposition of fenpropimorph following volatilisation from treated crops.

PubMed

Hassink, Jan; Platz, Klaus; Stadler, Reinhold; Zangmeister, Werner; Fent, Gunnar; Möndel, Martin; Kubiak, Roland

2007-02-01

The potential for short-range transport via air, i.e. volatilisation from the area of application and subsequent deposition on adjacent non-target areas, was investigated for the fungicide fenpropimorph in a wind tunnel system and under outdoor conditions in a higher-tier field study. Fenpropimorph 750 g L(-1) EC was applied post-emergence to cereal along with a reference standard lindane EC. Stainless steel containers of water were placed at different distances downwind of the application area to trap volatile residues during a study period of 24 h following application. Meteorological conditions in the wind tunnel as well as on the field were constantly monitored during the study period. The wind tunnel system was a partly standardised system on a semi-field scale, i.e. wind direction and wind speed (2 m s(-1)) were constant, but temperature and humidity varied according to the conditions outside. In the field experiment, the average wind speed over the 24 h study period was 3 m s(-1) and no rainfall occurred. Three different measuring lines were installed on the non-target area beside the treated field to cover potential variations in the wind direction. However, no significant differences were observed since the wind direction was generally constant. Fenpropimorph was detected in minor amounts of 0.01-0.05% of the applied material in the wind tunnel experiment. Even at a distance of 1 m beside the treated field, no significant deposition occurred (0.04% of applied material after 24 h). In the field, less than 0.1% of the applied fenpropimorph was detected at 0 m directly beside the treated field. At 5 m distance the deposition values were below 0.04%, and at 20 m distance about 0.01%. In general, the amounts of deposited fenpropimorph detected in the partly standardised wind tunnel system and the higher-tier field study were in good agreement.

Remote Sensor Application Studies Progress Report, July L, 1968 to June 30, 1969. Controlled Field Experiments

USGS Publications Warehouse

Rowan, L.C.; Offield, T.W.; Watson, R.D.; Cannon, P.J.; Grolier, H.J.; Pohn, H.A.; Watson, Kenneth

1970-01-01

Field Sites have been selected for controlled experiments to analyze physical and chemical parameters affecting the response of electromagnetic radiation to geological materials. Considerations in the selection of the sites are the availability of good exposures of nearly monomineralic rocks, level of geologic understanding, and ease of access. Seven sites, where work is underway or planned, contain extensive outcrops of the following rocks: stanstone, limestone, dolomite, and gypsum. Field measurement of quartz have been conducted at four sites.

CRYSTAL: The Cirrus Regional Study of Tropical Anvils and Layers

NASA Technical Reports Server (NTRS)

Delnore, Victor E.; Cox, Stephen K.; Curran, Robert J.

1999-01-01

CRYSTAL the Cirrus Regional Study of Tropical Anvils and Layers is part of the ongoing series of field experiments to study clouds and their impact on world weather and climate, and will attempt to improve the application of cloud effects in global climate models. CRYSTAL is being planned as two parts: a limited CRYSTAL field campaign in 2001 to examine towering clouds and anvil genesis over the Everglades of Florida, and the main CRYSTAL field campaign in the summer of 2003 in the Tropical Western Pacific. The latter is timed to take advantage of several cloud measurement satellites that will be operational at that time. This paper discusses some of the issues to be addressed in CRYSTAL, gives a brief description of the research plan, and describes its relationship to other important field experiments.

A theoretical approach to measuring pilot workload

NASA Technical Reports Server (NTRS)

Kantowitz, B. H.

1984-01-01

Theoretical assumptions used by researchers in the area of attention, with emphasis upon errors and inconsistent assumptions used by some researchers were studied. Two GAT experiments, two laboratory studies and one field experiment were conducted.

Superconducting shielding with Pb and Nb tubes for momentum sensitive measurements of neutral antimatter

NASA Astrophysics Data System (ADS)

Hinterberger, A.; Gerber, S.; Doser, M.

2017-09-01

In this paper we report on measurements and simulations of superconducting tubes in the presence of inhomogeneous externally applied magnetic fields in a cryogenic environment. The shielding effect is studied for two different tube materials, Pb and Nb, employing Hall sensors in a tabletop experiment. The measured internal and external fields of the tubes agree with the theory of the Meissner-Ochsenfeld effect [1], field trapping of type 2 superconductors, phase transitions and tube geometries. The obtained measurements are compared to a finite element simulation. Next, the simulation model is applied to estimate the shielding effect in the vicinity of a cryogenic Penning trap experiment. The controlled suppression of external magnetic fields is important for future precision experiments in atomic and antimatter physics in cryogenic environments.

Preliminary calibration plan for the Advanced Particles and Field Observatory (APAFO) magnetometer experiment

NASA Technical Reports Server (NTRS)

Voorhies, C. V.; Langel, R. A.; Slavin, J.; Lancaster, E. R.; Jones, S.

1991-01-01

Prelaunch and postlaunch calibration plans for the APAFO magnetometer experiment are presented. A study of tradeoffs between boom length and spacecraft field is described; the results are summarized. The prelaunch plan includes: calibration of the Vector Fluxgate Magnetometer (VFM), Star Sensors, and Scalar Helium Magnetometer (SHM); optical bench integration; and acquisition of basic spacecraft field data. Postlaunch calibration has two phases. In phase one, SHM data are used to calibrate the VFM, total vector magnetic field data are used to calibrate a physical model of the spacecraft field, and both calibrations are refined by iteration. In phase two, corrected vector data are transformed into geocentric coordinates, previously undetected spacecraft fields are isolated, and initial geomagnetic field models are computed. Provided the SHM is accurate to the required 1.0 nT and can be used to calibrate the VFM to the required 3.0- nT accuracy, the tradeoff study indicates that a 12 m boom and a spacecraft field model uncertainty of 5 percent together allow the 1.0 nT spacecraft field error requirement to be met.

Large-N solution of the Sp(N) Heisenberg quantum antiferromagnet on the anisotropic triangular lattice in a magnetic field.

NASA Astrophysics Data System (ADS)

Chung, Chung-Hou; Marston, Brad

2002-03-01

We study the Sp(N) generalization of the physical Sp(1) \\cong SU(2) Heisenberg antiferromagnet on the anisotropic triangular lattice( C. H. Chung, J. B. Marston and R. H. McKenzie, Journal of Physics: Condensed Matter 13), 5159 (2001). in a magnetic field. The model is relevant for describing recent experiments on the magnetic phases of the quasi-2D system Cs_2CuCl4 in a magnetic field(R. Coldea, D. A. Tennant, A. M. Tsvelik, and Z. Tylczynski, Phys. Rev. Lett. 86), 1335 (2001).. We solve the model in the large-N limit and study the effect of a magnetic field on the incommensurate magnetic order. Below a critical field the spins form a ``cone'' of polarization, in apparent agreement with neutron scattering experiments when the magnetic field is oriented perpendicular to the lattice. The incommensuration increases with increasing field strength. Above the critical field the spins are fully polarized. We have difficulty treating Dzyaloshinskii-Moriya interactions which are believed to be important for in-plane fields.

Meta-analysis of field experiments shows no change in racial discrimination in hiring over time.

PubMed

Quillian, Lincoln; Pager, Devah; Hexel, Ole; Midtbøen, Arnfinn H

2017-10-10

This study investigates change over time in the level of hiring discrimination in US labor markets. We perform a meta-analysis of every available field experiment of hiring discrimination against African Americans or Latinos ( n = 28). Together, these studies represent 55,842 applications submitted for 26,326 positions. We focus on trends since 1989 ( n = 24 studies), when field experiments became more common and improved methodologically. Since 1989, whites receive on average 36% more callbacks than African Americans, and 24% more callbacks than Latinos. We observe no change in the level of hiring discrimination against African Americans over the past 25 years, although we find modest evidence of a decline in discrimination against Latinos. Accounting for applicant education, applicant gender, study method, occupational groups, and local labor market conditions does little to alter this result. Contrary to claims of declining discrimination in American society, our estimates suggest that levels of discrimination remain largely unchanged, at least at the point of hire.

A Tilted Plane as a Gravitational Field Model.

ERIC Educational Resources Information Center

Hale, D. P.

1980-01-01

Describes an experiment for the use of a tilted plane as a two-dimensional uniform gravitational field to demonstrate the motion of projectiles, to determine the fundamental laws of mechanics, or to study the focusing properties of the uniform field. (SK)

Creating Your Own Case Studies: A Guide for Early Field Experience.

ERIC Educational Resources Information Center

Florio-Ruane, Susan

1990-01-01

A guide for creating case studies is provided for teacher educators to share with students. Suggestions are offered for becoming a participant observer in a classroom. The appendix contains sample appropriate and inappropriate field notes. (SM)

FIRE Arctic Clouds Experiment

NASA Technical Reports Server (NTRS)

Curry, J. A.; Hobbs, P. V.; King, M. D.; Randall, D. A.; Minnis, P.; Issac, G. A.; Pinto, J. O.; Uttal, T.; Bucholtz, A.; Cripe, D. G.;

Lessons from a Dominican Republic Field Study

ERIC Educational Resources Information Center

Gunter, Michael M., Jr.

2010-01-01

Utilizing student-centered pedagogy, this case study explores an increasingly prominent and instructive addition to traditional academic coursework--the field study experience. This is particularly true in the arena of environmental education where students learn best by experiencing environmental problems first-hand and then interacting with…

International Field Experience as an Impetus for Personal and Professional Transformation: Through the Lens of Early Childhood Postsecondary Students

ERIC Educational Resources Information Center

Bonnett, Tina Heather

2015-01-01

Research exploring preservice postsecondary students' experiences participating in an international field placement is a relatively new area of study in the domains of Early Childhood Education (ECE) and Early Childhood Leadership (ECL). While there is a growing body of literature offering merit to the profound transformations that can occur for…

Lessons from Cuba: Using Sense of Place as a Tool to Connect Internationally and at Home

ERIC Educational Resources Information Center

Dear, Samantha; Sayle, Hilary

2011-01-01

In the spring of 2010, 16 Recreation and Leisure Studies students from Brock University in St. Catharines, Ontario, travelled to Cuba to complete a fourth-year field class titled International Field Experiences in Recreation and Leisure. After a week spent in Havana, Brock University students engaged in a unique outdoor education experience. With…

The Effect of Teacher-Family Communication on Student Engagement: Evidence from a Randomized Field Experiment

ERIC Educational Resources Information Center

Kraft, Matthew A.; Dougherty, Shaun M.

2013-01-01

In this study, we evaluate the efficacy of teacher communication with parents and students as a means of increasing student engagement. We estimate the causal effect of teacher communication by conducting a randomized field experiment in which sixth- and ninth-grade students were assigned to receive a daily phone call home and a text/written…

The Influence of Teacher Preparation Programs' Field Experiences on Pre-Service Teacher Candidates' Sense of Teaching Efficacy

ERIC Educational Resources Information Center

Reddy, Alison Marie

2012-01-01

In this descriptive, mixed methods study, the researcher investigated the influence of teacher preparation programs' field experiences on teacher candidates' sense of teaching efficacy. Tschannen-Morgan & Woolfolk-Hoy's (2001) Teacher Sense of Efficacy Scale questionnaire was sent to 221 teacher candidates enrolled in one of…

Using Experiment and Computer Modeling to Determine the Off-Axis Magnetic Field of a Solenoid

ERIC Educational Resources Information Center

Lietor-Santos, Juan Jose

2014-01-01

The study of the ideal solenoid is a common topic among introductory-based physics textbooks and a typical current arrangement in laboratory hands-on experiences where the magnetic field inside a solenoid is determined at different currents and at different distances from its center using a magnetic probe. It additionally provides a very simple…

The Field Trip Book: Study Travel Experiences in Social Studies

ERIC Educational Resources Information Center

Morris, Ronald V.

2010-01-01

Looking for social studies adventures to help students find connections to democratic citizenship? Look no further! This book provides just the answer teachers need for engaging students in field trips as researching learners with emphasis on interdisciplinary social studies plus skills in collecting and reporting data gathered from field…

Turbulent Dynamo Amplification of Magnetic Fields in Laser-Produced Plasmas: Simulations and Experiments

NASA Astrophysics Data System (ADS)

Tzeferacos, P.; Rigby, A.; Bott, A.; Bell, A.; Bingham, R.; Casner, A.; Cattaneo, F.; Churazov, E.; Forest, C.; Katz, J.; Koenig, M.; Li, C.-K.; Meinecke, J.; Petrasso, R.; Park, H.-S.; Remington, B.; Ross, J.; Ryutov, D.; Ryu, D.; Reville, B.; Miniati, F.; Schekochihin, A.; Froula, D.; Lamb, D.; Gregori, G.

2017-10-01

The universe is permeated by magnetic fields, with strengths ranging from a femtogauss in the voids between the filaments of galaxy clusters to several teragauss in black holes and neutron stars. The standard model for cosmological magnetic fields is the nonlinear amplification of seed fields via turbulent dynamo. We have conceived experiments to demonstrate and study the turbulent dynamo mechanism in the laboratory. Here, we describe the design of these experiments through large-scale 3D FLASH simulations on the Mira supercomputer at ANL, and the laser-driven experiments we conducted with the OMEGA laser at LLE. Our results indicate that turbulence is capable of rapidly amplifying seed fields to near equipartition with the turbulent fluid motions. This work was supported in part from the ERC (FP7/2007-2013, No. 256973 and 247039), and the U.S. DOE, Contract No. B591485 to LLNL, FWP 57789 to ANL, Grant No. DE-NA0002724 and DE-SC0016566 to the University of Chicago, and DE-AC02-06CH11357 to ANL.

Biochar: from laboratory mechanisms through the greenhouse to field trials

NASA Astrophysics Data System (ADS)

Masiello, C. A.; Gao, X.; Dugan, B.; Silberg, J. J.; Zygourakis, K.; Alvarez, P. J. J.

2014-12-01

The biochar community is excellent at pointing to individual cases where biochar amendment has changed soil properties, with some studies showing significant improvements in crop yields, reduction in nutrient export, and remediation of pollutants. However, many studies exist which do not show improvements, and in some cases, studies clearly show detrimental outcomes. The next, crucial step in biochar science and engineering research will be to develop a process-based understanding of how biochar acts to improve soil properties. In particular, we need a better mechanistic understanding of how biochar sorbs and desorbs contaminants, how it interacts with soil water, and how it interacts with the soil microbial community. These mechanistic studies need to encompass processes that range from the nanometer to the kilometer scale. At the nanometer scale, we need a predictive model of how biochar will sorb and desorb hydrocarbons, nutrients, and toxic metals. At the micrometer scale we need models that explain biochar's effects on soil water, especially the plant-available fraction of soil water. The micrometer scale is also where mechanistic information is neeed about microbial processes. At the macroscale we need physical models to describe the landscape mobility of biochar, because biochar that washes away from fields can no longer provide crop benefits. To be most informative, biochar research should occur along a lab-greenhouse-field trial trajectory. Laboratory experiments should aim determine what mechanisms may act to control biochar-soil processes, and then greenhouse experiments can be used to test the significance of lab-derived mechanisms in short, highly replicated, controlled experiments. Once evidence of effect is determined from greenhouse experiments, field trials are merited. Field trials are the gold standard needed prior to full deployment, but results from field trials cannot be extrapolated to other field sites without the mechanistic backup provided by greenhouse and lab trials.

Assessing the influence of field- and GIS-based inquiry on student attitude and conceptual knowledge in an undergraduate ecology lab.

PubMed

Simmons, M E; Wu, X B; Knight, S L; Lopez, R R

2008-01-01

Combining field experience with use of information technology has the potential to create a problem-based learning environment that engages learners in authentic scientific inquiry. This study, conducted over a 2-yr period, determined differences in attitudes and conceptual knowledge between students in a field lab and students with combined field and geographic information systems (GIS) experience. All students used radio-telemetry equipment to locate fox squirrels, while one group of students was provided an additional data set in a GIS to visualize and quantify squirrel locations. Pre/postsurveys and tests revealed that attitudes improved in year 1 for both groups of students, but differences were minimal between groups. Attitudes generally declined in year 2 due to a change in the authenticity of the field experience; however, attitudes for students that used GIS declined less than those with field experience only. Conceptual knowledge also increased for both groups in both years. The field-based nature of this lab likely had a greater influence on student attitude and conceptual knowledge than did the use of GIS. Although significant differences were limited, GIS did not negatively impact student attitude or conceptual knowledge but potentially provided other benefits to learners.

Technology, Accuracy and Scientific Thought in Field Camp: An Ethnographic Study

ERIC Educational Resources Information Center

Feig, Anthony D.

2010-01-01

An ethnographic study was conducted on an undergraduate field course to observe and document lived experiences of students. This paper evaluates one of several emergent themes: that of technology dependence, and how it informs students' understanding of scientific reality. In the field, students tried to arm themselves with as high a degree of…

What are undergraduates doing at biological field stations and marine laboratories?

Treesearch

Janet Hodder

2009-01-01

Biological field stations and marine laboratories (FSMLs) serve as places to study the natural environment in a variety of ways, from the level of the molecule to the globe. Undergraduate opportunities at FSMLs reflect the diversity of study options -- formal courses, research and service internships, and field-trip experiences -- and students are responding to those...

Predicting Performance in an Advanced Undergraduate Geological Field Camp Experience

ERIC Educational Resources Information Center

Dykas, Matthew J.; Valentino, David W.

2016-01-01

This study examined the factors that contribute to students' success in conducting geological field work. Undergraduate students (n = 49; 51% female; mean age = 22 y) who were enrolled in the 5-wk State University of New York at Oswego (SUNY Oswego) geology field program volunteered to participate in this study. At the beginning of the field…

A Nimbus G pre-launch field experiment in the Gulf of Mexico, October 1977

NASA Technical Reports Server (NTRS)

Vanderpiepen, H.

1977-01-01

A large scale field experiment, which was arranged in support of the Nimbus G - Coastal Zone Color Scanner (CZCS) project was studied. The experiment was to provide three air and two shipborne platforms simultaneously to members of the Nimbus G Experiment Team (NET) and to other scientists in order to collect data from common test sites. Besides establishing fundamental relations between the light in the sea and the biochemical properties of water, the data will be used mainly for the development of algorithms during the prelaunch phase of Nimbus G.

Calculations of low-frequency radio emission by cosmic-ray-induced particle showers

NASA Astrophysics Data System (ADS)

García-Fernández, Daniel; Revenu, Benoît; Charrier, Didier; Dallier, Richard; Escudie, Antony; Martin, Lilian

2018-05-01

The radio technique for the detection of high-energy cosmic rays consists in measuring the electric field created by the particle showers created inside a medium by the primary cosmic ray. The electric field is then used to infer the properties of the primary particle. Nowadays, the radio technique is a standard, well-established technique. While most current experiments measure the field at frequencies above 20 MHz, several experiments have reported a large emission at low frequencies, below 10 MHz. The EXTASIS experiment aims at measuring again and understanding this low-frequency electric field. Since at low frequencies the standard far-field approximation for the calculation of the electric field does not necessarily hold, in order to comprehend the low-frequency emission we need to go beyond the far-field approximation. We present in this work a formula for the electric field created by a particle track inside a dielectric medium that is valid for all frequencies. We then implement this formula in the SELFAS Monte Carlo code and calculate the low-frequency electric field of the extensive air shower (EAS). We also study the electric field of a special case of the transition radiation mechanism when the EAS particles cross the air-soil boundary. We introduce the sudden death pulse, the direct emission caused by the coherent deceleration of the shower front at the boundary, as a first approximation to the whole electric field for the air-soil transition, and study its properties. We show that at frequencies larger than 20 MHz and distances larger than 100 m, the standard far-field approximation for the horizontal polarizations of the field is always accurate at the 1% level.

a Study of the Interaction of Atoms with Strong Laser Fields.

NASA Astrophysics Data System (ADS)

Edwards, Mark

1984-02-01

In this thesis three aspects of the interactions of atoms with high intensity laser fields were treated. All three were motivated by experiment. The first investigation was prompted by a recent experiment (Kruit et al. 1983) involving multiphoton ionization of Xe. In this experiment it was found that the photoelectron energy spectrum contained peaks which corresponded to the absorption of more than the minimum number of photons required to ionize the atom. The effective orders of nonlinearity, furthermore, showed a striking uniformity. These effects were investigated using a model approximation consisting of a single bound state and m continua. Simple analytic expressions were obtained for the quantities measured in the experiment and the limit m (--->) (INFIN) was obtained. The results showed good qualitative agreement with experiment. An experiment (Grove et al. 1977) designed to test a theoretical calculation of the dynamical Stark effect stimulated the second part of this thesis. When experimental conditions were varied slightly, strong field turn-on effects were observed in the resonance fluorescence spectrum from a two-level atom (TLA). This experimental result led to the present study of how an adiabatically and near-adiabatically changing field intensity affects the resonance fluorescence spectrum of a TLA. It was found that there is an asymmetry in the spectrum for off-resonance excitation produced because the field turn-on repopulates the dressed state that is depopulated by spontaneous emission. The experimental result was not explained by this result, however. The third part of this thesis was based on an experiment (Granneman and Van der Wiel 1976) which attempted to verify a perturbation calculation of the two-photon ionization cross section of Cs. A discrepancy of four orders of magnitude near a minimum in the cross section was found between theory and experiment. To explain this discrepancy it was suggested (Armstrong and Beers 1977) that the effective order of nonlinearity (k) for this process varied significantly around the minimum. The present study involves a perturbation calculation of k. It was found that k varies rapidly around the minimum, and that this variation should be experimentally observable for laser intensities of the order of tens of GW cm('-2).

Effect of magnetic field on the phase transition in a dusty plasma

NASA Astrophysics Data System (ADS)

Jaiswal, S.; Hall, T.; LeBlanc, S.; Mukherjee, R.; Thomas, E.

2017-11-01

The formation of a self-consistent crystalline structure is a well-known phenomenon in complex plasmas. In most experiments, the pressure and rf power are the main controlling parameters in determining the phase of the system. We have studied the effect of the externally applied magnetic field on the configuration of plasma crystals, suspended in the sheath of a radio-frequency discharge using the Magnetized Dusty Plasma Experiment device. Experiments are performed at a fixed pressure and rf power where a crystalline structure is formed within a confining ring. The magnetic field is then increased from 0 to 1.28 T. We report on the breakdown of the crystalline structure with the increasing magnetic field. The magnetic field affects the dynamics of the plasma particles and first leads to a rotation of the crystal. At a higher magnetic field, there is a radial variation (shear) in the angular velocity of the moving particles which we believe to lead to the melting of the crystal. This melting is confirmed by evaluating the variation of the pair correlation function as a function of magnetic field.

Writing Assessment's "Debilitating Inheritance": Behaviorism's Dismissal of Experience

ERIC Educational Resources Information Center

Wilson, Maja Joiwind

2013-01-01

In this project, I examine the legacy of behaviorism's dismissal of experience on contemporary writing assessment theory and practice within the field of composition studies. I use an archival study of John B. Watson's letters to Robert Mearns Yerkes to establish behaviorism's systematic denial of experience and its related constructs: mind,…

Photovoice as an Evaluation Tool for Student Learning on a Field Trip

ERIC Educational Resources Information Center

Behrendt, Marc; Machtmes, Krisanna

2016-01-01

Background: Photovoice is one method that enables an educator to view an experience from a student's perspective. This study examined how teachers might use photovoice during an informal learning experience to understand the students' experiences and experiential gain. Design and methods: Participants in this study consisted of six students, three…

MISR Browse Images: Puerto Rico Dust Experiment (PRiDE)

Atmospheric Science Data Center

2013-04-02

MISR Browse Images: Puerto Rico Dust Experiment (PRiDE) These MISR Browse ... a quick visual overview of the region observed during the Puerto Rico Dust Experiment (PRiDE) field campaign. PRiDE was a study of the ...

Untangling the effects of root age and tissue nitrogen on root respiration in Populus tremuloides at different nitrogen supply

PubMed Central

Ceccon, Christian; Tagliavini, Massimo; Schmitt, Armin Otto; Eissenstat, David M.

2016-01-01

Root respiration is a major contributor to terrestrial carbon flux. Many studies have shown root respiration to increase with an increase in root tissue nitrogen (N) concentration across species and study sites. Studies have also shown that both root respiration and root N concentration typically decrease with root age. The effects of added N may directly increase respiration of existing roots or may affect respiration by shifting the age structure of a root population by stimulating growth. To the best of our knowledge, no study has ever examined the effect of added N as a function of root age on root respiration. In this study, root respiration of 13-year-old Populus tremuloides Michx. trees grown in the field and 1-year-old P. tremuloides seedlings grown in containers was analyzed for the relative influence of root age and root N concentration independent of root age on root respiration. Field roots were first tracked using root windows and then sampled at known age. Nitrogen was either applied or not to small patches beneath the windows. In a pot experiment, each plant was grown with its root system split between two separate pots and N was applied at three different levels, either at the same or at different rates between pots. Root N concentration ranged between 1.4 and 1.7% in the field experiment and 1.8 and 2.6% in the seedling experiment. We found that addition of N increased root N concentration of only older roots in the field but of roots of all ages in the potted seedlings. In both experiments, the age-dependent decline in root respiration was largely consistent, and could be explained by a negative power function. Respiration decreased ∼50% by 3 weeks of age. Although root age was the dominant factor affecting respiration in both experiments, in the field experiment, root N also contributed to root respiration independent of root age. These results add further insight into respiratory responses of roots to N addition and mechanisms underlying the tissue N–respiration relationship. PMID:27095257

Neuroaesthetics: The Cognitive Neuroscience of Aesthetic Experience.

PubMed

Pearce, Marcus T; Zaidel, Dahlia W; Vartanian, Oshin; Skov, Martin; Leder, Helmut; Chatterjee, Anjan; Nadal, Marcos

2016-03-01

The field of neuroaesthetics has gained in popularity in recent years but also attracted criticism from the perspectives both of the humanities and the sciences. In an effort to consolidate research in the field, we characterize neuroaesthetics as the cognitive neuroscience of aesthetic experience, drawing on long traditions of research in empirical aesthetics on the one hand and cognitive neuroscience on the other. We clarify the aims and scope of the field, identifying relations among neuroscientific investigations of aesthetics, beauty, and art. The approach we advocate takes as its object of study a wide spectrum of aesthetic experiences, resulting from interactions of individuals, sensory stimuli, and context. Drawing on its parent fields, a cognitive neuroscience of aesthetics would investigate the complex cognitive processes and functional networks of brain regions involved in those experiences without placing a value on them. Thus, the cognitive neuroscientific approach may develop in a way that is mutually complementary to approaches in the humanities. © The Author(s) 2016.

Segmented-field radiography in scoliosis

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

Daniel, W.W.; Barnes, G.T.; Nasca, R.J.

1985-02-01

A method of scoliosis imaging using segmented fields is presented. The method is advantageous for patients requiring serial radiographic monitoring, as it results in markedly reduced radiation doses to critical organs, particularly the breast. Absorbed dose to the breast was measured to be 8.8 mrad (88 ..mu..Gy) for a full-field examination and 0.051 mrad (5.1 ..mu..Gy) for the segmented-field study. The segmented-field technique also results in improved image quality. Experience with 53 studies in 23 patients is reported.

Passive Microwave Precipitation Retrieval Uncertainty Characterized based on Field Campaign Data over Complex Terrain

NASA Astrophysics Data System (ADS)

Derin, Y.; Anagnostou, E. N.; Anagnostou, M.; Kalogiros, J. A.; Casella, D.; Marra, A. C.; Panegrossi, G.; Sanò, P.

2017-12-01

Difficulties in representation of high rainfall variability over mountainous areas using ground based sensors make satellite remote sensing techniques attractive for hydrologic studies over these regions. Even though satellite-based rainfall measurements are quasi global and available at high spatial resolution, these products have uncertainties that necessitate use of error characterization and correction procedures based upon more accurate in situ rainfall measurements. Such measurements can be obtained from field campaigns facilitated by research quality sensors such as locally deployed weather radar and in situ weather stations. This study uses such high quality and resolution rainfall estimates derived from dual-polarization X-band radar (XPOL) observations from three field experiments in Mid-Atlantic US East Coast (NASA IPHEX experiment), the Olympic Peninsula of Washington State (NASA OLYMPEX experiment), and the Mediterranean to characterize the error characteristics of multiple passive microwave (PMW) sensor retrievals. The study first conducts an independent error analysis of the XPOL radar reference rainfall fields against in situ rain gauges and disdrometer observations available by the field experiments. Then the study evaluates different PMW precipitation products using the XPOL datasets (GR) over the three aforementioned complex terrain study areas. We extracted matchups of PMW/GR rainfall based on a matching methodology that identifies GR volume scans coincident with PMW field-of-view sampling volumes, and scaled GR parameters to the satellite products' nominal spatial resolution. The following PMW precipitation retrieval algorithms are evaluated: the NASA Goddard PROFiling algorithm (GPROF), standard and climatology-based products (V 3, 4 and 5) from four PMW sensors (SSMIS, MHS, GMI, and AMSR2), and the precipitation products based on the algorithms Cloud Dynamics and Radiation Database (CDRD) for SSMIS and Passive microwave Neural network Precipitation Retrieval (PNPR) for AMSU/MHS, developed at ISAC-CNR within the EUMETSAT H-SAF. We will present error analysis results for the different PMW rainfall retrievals and discuss dependences on precipitation type, elevation and precipitation microphysics (derived from XPOL).

Towards a sterile insect technique field release of Anopheles arabiensis mosquitoes in Sudan: Irradiation, transportation, and field cage experimentation

PubMed Central

Helinski, Michelle EH; Hassan, Mo'awia M; El-Motasim, Waleed M; Malcolm, Colin A; Knols, Bart GJ; El-Sayed, Badria

2008-01-01

Background The work described in this article forms part of a study to suppress a population of the malaria vector Anopheles arabiensis in Northern State, Sudan, with the Sterile Insect Technique. No data have previously been collected on the irradiation and transportation of anopheline mosquitoes in Africa, and the first series of attempts to do this in Sudan are reported here. In addition, experiments in a large field cage under near-natural conditions are described. Methods Mosquitoes were irradiated in Khartoum and transported as adults by air to the field site earmarked for future releases (400 km from the laboratory). The field cage was prepared for experiments by creating resting sites with favourable conditions. The mating and survival of (irradiated) laboratory males and field-collected males was studied in the field cage, and two small-scale competition experiments were performed. Results Minor problems were experienced with the irradiation of insects, mostly associated with the absence of a rearing facility in close proximity to the irradiation source. The small-scale transportation of adult mosquitoes to the release site resulted in minimal mortality (< 6%). Experiments in the field cage showed that mating occurred in high frequencies (i.e. an average of 60% insemination of females after one or two nights of mating), and laboratory reared males (i.e. sixty generations) were able to inseminate wild females at rates comparable to wild males. Based on wing length data, there was no size preference of males for mates. Survival of mosquitoes from the cage, based on recapture after mating, was satisfactory and approximately 60% of the insects were recaptured after one night. Only limited information on male competitiveness was obtained due to problems associated with individual egg laying of small numbers of wild females. Conclusion It is concluded that although conditions are challenging, there are no major obstacles associated with the small-scale irradiation and transportation of insects in the current setting. The field cage is suitable for experiments and studies to test the competitiveness of irradiated males can be pursued. The scaling up of procedures to accommodate much larger numbers of insects needed for a release is the next challenge and recommendations to further implementation of this genetic control strategy are presented. PMID:18439238

The Kosmos-1129 biosatellite. [experiments in biological effects of space flight

NASA Technical Reports Server (NTRS)

Nikitin, S. A.

1980-01-01

A number of experiments, designed by participating specialists from several countries, are described. The experiments included studies in biorhythm, stress, body parts, behavior, ontogenesis, and gravitational preference. The biological subjects of the experiments were retrieved immediately after the landing of the satellite and examined in a field laboratory.

The student fieldwork experience: influencing factors and implications for learning

NASA Astrophysics Data System (ADS)

Boyle, Alan; Stokes, Alison

2010-05-01

Fieldwork has always been a crucial component of undergraduate geoscience degrees, yet our understanding of the learning processes that operate in a field environment is limited. Learning is a complex process, and there is increasing interest in the role played in this process by the affective domain, in particular the link between affect (emotion and attitude) and cognition (understanding). This presentation covers two UK-based studies that investigated the impact of residential geoscience fieldwork on students' affective responses (e.g. feelings, attitudes, motivations), and their subsequent learning outcomes; student affective responses are thought to be linked to the adoption of effective approaches to learning. The first study involved ~300 students from 7 UK universities undertaking residential field classes in, geography, earth and environmental sciences (GEES disciplines). Mixed-format surveys applied before and after fieldwork demonstrated significant effects in the affective domain. In general, student responses were very positive prior to fieldwork and became more positive as a result of the field experience. The data were analysed for any subgroup differences (gender, age, previous experience) but the only significant difference concerned levels of anxiety amongst some groups of students prior to fieldwork. However, post fieldwork surveys showed that the field experience mitigated these anxieties; for most it was not as bad as they thought it would be. This study demonstrated that fieldwork generated positive attitudes amongst students to their subject of study as well as development of ‘soft' interpersonal skills. The second study collected qualitative and quantitative data from 62 students at a single UK university before, during and after a nine day geologic mapping-training field course, a style of fieldwork not surveyed in the first study. As with the first study, pre-field class positive affects became strengthened, while negative feelings and attitudes were ameliorated as a result of the fieldwork. However, some aspects of the students' experience generated new negative responses, whilst extra-curricular social and cultural activities generated unexpectedly positive responses. In terms of outcomes the geological mapping training fieldwork enabled students to develop generic as well as subject-specific skills, e.g. teamwork, decision making, and autonomy, whilst engagement in social interactions both within and outside of the field environment enabled the development of valuable interpersonal skills. Both studies demonstrate the positive effect of residential field work on students' attitudes and feelings towards their subject but also towards fellow students and academic staff through the development of interpersonal skills. Such skills are seldom assessed as learning outcomes, but are an important part of students' development from novice to expert geoscientists, and a vital component of the wider competences required by employers and society. They are potentially best developed during residential fieldwork and help to make GEES students employable.

Chaos of energetic positron orbits in a dipole magnetic field and its potential application to a new injection scheme

NASA Astrophysics Data System (ADS)

Saitoh, H.; Yoshida, Z.; Yano, Y.; Nishiura, M.; Kawazura, Y.; Horn-Stanja, J.; Pedersen, T. Sunn

2016-10-01

We study the behavior of high-energy positrons emitted from a radioactive source in a magnetospheric dipole field configuration. Because the conservation of the first and second adiabatic invariants is easily destroyed in a strongly inhomogeneous dipole field for high-energy charged particles, the positron orbits are nonintegrable, resulting in chaotic motions. In the geometry of a typical magnetospheric levitated dipole experiment, it is shown that a considerable ratio of positrons from a 22Na source, located at the edge of the confinement region, has chaotic long orbit lengths before annihilation. These particles make multiple toroidal circulations and form a hollow toroidal positron cloud. Experiments with a small 22Na source in the Ring Trap 1 (RT-1) device demonstrated the existence of such long-lived positrons in a dipole field. Such a chaotic behavior of high-energy particles is potentially applicable to the formation of a dense toroidal positron cloud in the strong-field region of the dipole field in future studies.

FULL SCALE PLUME STUDY: A SUMMARY OF DATA COLLECTED AND PHENOMENA OBSERVED

EPA Science Inventory

The paper briefly describes the field tracer studies that were conducted in support of EPA's Complex Terrain Model Development project. A more detailed description is given of the last field study, conducted from the Tracy Power Plant near Reno, Nevada. During 14 experiment perio...

SMILE (Shared Mentoring in Instructional Learning Environments): Effectiveness of a Lesson-Study Approach to Student-Teaching Supervision on a Teacher-Education Performance Assessment

ERIC Educational Resources Information Center

Chizhik, Estella Williams; Chizhik, Alexander Williams; Close, Catherine; Gallego, Margaret

2017-01-01

Student-teaching field placements play an important role in preparing teacher candidates, many of whom rate the practice as the most authentic and relevant learning experience associated with their teacher-education programs. As a part of these field experiences, teacher candidates have opportunities to learn instructional and class management…

Secondary School Students Learning from Reflections on the Rationale behind Self-Made Errors: A Field Experiment

ERIC Educational Resources Information Center

Heemsoth, Tim; Heinze, Aiso

2016-01-01

Thus far, it is unclear how students can learn most effectively from their own errors. In this study, reflections on the rationale behind self-made errors are assumed to enhance knowledge acquisition. In a field experiment with pre/post/follow-up design, the authors practiced fractions with 174 seventh- and eighth-grade students who were randomly…

Jupiter Environmental Research & Field Studies Academy.

ERIC Educational Resources Information Center

Huttemeyer, Bob

1996-01-01

Describes the development and workings of the Jupiter Environmental Research and Field Studies Academy that focuses on enabling both teachers and students to participate in real-life learning experiences. Discusses qualifications for admittance, curriculum, location, ongoing projects, students, academics, preparation for life, problem solving, and…

Preference effects on friendship choice: Evidence from an online field experiment.

PubMed

Yu, Siyu; Xie, Yu

2017-08-01

Observed friendship choices are constrained by social structures and thus problematic indicators for underlying personal preferences. In this paper, we report on a study demonstrating the causal effects of preference in friendship choice based on an online field experiment. Specifically, we tested two important forces that govern friendship choices: preference for shared group identity (operationalized as the desire to befriend others sharing the same place-of-origin identity) and preference for high status (operationalized as the desire to befriend others from high-status institutions). Using an online field experiment in one of the largest social network service websites in China, we investigated the causal preference effects of these two forces free from structural constraints. The results of our study confirm the preference effects on friendship choice in both of the two dimensions we tested. Copyright © 2017. Published by Elsevier Inc.

Positron Annihilation Ratio Spectroscopy (PsARS) Applied to Positronium Formation Studies

DTIC Science & Technology

2010-03-01

POSITRON ANNIHILATION RATIO SPECTROSCOPY (PsARS) APPLIED TO POSITRONIUM FORMATION STUDIES THESIS...AFIT/GNE/ENP/10-M07 POSITRON ANNIHILATION RATIO SPECTROSCOPY (PsARS) APPLIED TO POSITRONIUM FORMATION STUDIES ...lifetime studies in local electric field experiments. High local electric fields can polarize a positron -electron pair, which may result in an extended

Linking manipulative experiments to field data to test the dilution effect.

PubMed

Venesky, Matthew D; Liu, Xuan; Sauer, Erin L; Rohr, Jason R

2014-05-01

The dilution effect, the hypothesis that biodiversity reduces disease risk, has received support in many systems. However, few dilution effect studies have linked mechanistic experiments to field patterns to establish both causality and ecological relevance. We conducted a series of laboratory experiments and tested the dilution effect hypothesis in an amphibian-Batrachochytrium dendrobatidis (Bd) system and tested for consistency between our laboratory experiments and field patterns of amphibian species richness, host identity and Bd prevalence. In our laboratory experiments, we show that tadpoles can filter feed Bd zoospores and that the degree of suspension feeding was positively associated with their dilution potential. The obligate suspension feeder, Gastrophryne carolinensis, generally diluted the risk of chytridiomycosis for tadpoles of Bufo terrestris and Hyla cinerea, whereas tadpoles of B. terrestris (an obligate benthos feeder) generally amplified infections for the other species. In addition, G. carolinensis reduced Bd abundance on H. cinerea more so in the presence than absence of B. terrestris and B. terrestris amplified Bd abundance on H. cinerea more so in the absence than presence of G. carolinensis. Also, when ignoring species identity, species richness was a significant negative predictor of Bd abundance. In our analysis of field data, the presence of Bufo spp. and Gastrophryne spp. were significant positive and negative predictors of Bd prevalence, respectively, even after controlling for climate, vegetation, anthropogenic factors (human footprint), species richness and sampling effort. These patterns of dilution and amplification supported our laboratory findings, demonstrating that the results are likely ecologically relevant. The results from our laboratory and field data support the dilution effect hypothesis and also suggest that dilution and amplification are predictable based on host traits. Our study is among the first to link manipulative experiments, in which a potential dilution mechanism is supported, with analyses of field data on species richness, host identity, spatial autocorrelation and disease prevalence. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.

Rehabilitation of jointed Portland cement concrete pavements : SPS-6--initial evaluation and analysis

DOT National Transportation Integrated Search

2005-10-01

The Specific Pavement Studies 6 (SPS-6) experiment, "Rehabilitation of Jointed Portland Cement Concrete Pavements," was designed as a controlled field experiment that focuses on the study of specific rehabilitation design features of jointed plain co...

Abiotic stress QTL in lettuce crop–wild hybrids: comparing greenhouse and field experiments

PubMed Central

Hartman, Yorike; Hooftman, Danny A P; Uwimana, Brigitte; Schranz, M Eric; van de Wiel, Clemens C M; Smulders, Marinus J M; Visser, Richard G F; Michelmore, Richard W; van Tienderen, Peter H

2014-01-01

The development of stress-tolerant crops is an increasingly important goal of current crop breeding. A higher abiotic stress tolerance could increase the probability of introgression of genes from crops to wild relatives. This is particularly relevant to the discussion on the risks of new GM crops that may be engineered to increase abiotic stress resistance. We investigated abiotic stress QTL in greenhouse and field experiments in which we subjected recombinant inbred lines from a cross between cultivated Lactuca sativa cv. Salinas and its wild relative L. serriola to drought, low nutrients, salt stress, and aboveground competition. Aboveground biomass at the end of the rosette stage was used as a proxy for the performance of plants under a particular stress. We detected a mosaic of abiotic stress QTL over the entire genome with little overlap between QTL from different stresses. The two QTL clusters that were identified reflected general growth rather than specific stress responses and colocated with clusters found in earlier studies for leaf shape and flowering time. Genetic correlations across treatments were often higher among different stress treatments within the same experiment (greenhouse or field), than among the same type of stress applied in different experiments. Moreover, the effects of the field stress treatments were more correlated with those of the greenhouse competition treatments than to those of the other greenhouse stress experiments, suggesting that competition rather than abiotic stress is a major factor in the field. In conclusion, the introgression risk of stress tolerance (trans-)genes under field conditions cannot easily be predicted based on genomic background selection patterns from controlled QTL experiments in greenhouses, especially field data will be needed to assess potential (negative) ecological effects of introgression of these transgenes into wild relatives. PMID:25360276

Biophysics of magnetic orientation: strengthening the interface between theory and experimental design

PubMed Central

Kirschvink, Joseph L.; Winklhofer, Michael; Walker, Michael M.

2010-01-01

The first demonstrations of magnetic effects on the behaviour of migratory birds and homing pigeons in laboratory and field experiments, respectively, provided evidence for the longstanding hypothesis that animals such as birds that migrate and home over long distances would benefit from possession of a magnetic sense. Subsequent identification of at least two plausible biophysical mechanisms for magnetoreception in animals, one based on biogenic magnetite and another on radical-pair biochemical reactions, led to major efforts over recent decades to test predictions of the two models, as well as efforts to understand the ultrastructure and function of the possible magnetoreceptor cells. Unfortunately, progress in understanding the magnetic sense has been challenged by: (i) the availability of a relatively small number of techniques for analysing behavioural responses to magnetic fields by animals; (ii) difficulty in achieving reproducible results using the techniques; and (iii) difficulty in development and implementation of new techniques that might bring greater experimental power. As a consequence, laboratory and field techniques used to study the magnetic sense today remain substantially unchanged, despite the huge developments in technology and instrumentation since the techniques were developed in the 1950s. New methods developed for behavioural study of the magnetic sense over the last 30 years include the use of laboratory conditioning techniques and tracking devices based on transmission of radio signals to and from satellites. Here we consider methodological developments in the study of the magnetic sense and present suggestions for increasing the reproducibility and ease of interpretation of experimental studies. We recommend that future experiments invest more effort in automating control of experiments and data capture, control of stimulation and full blinding of experiments in the rare cases where automation is impossible. We also propose new experiments to confirm whether or not animals can detect magnetic fields using the radical-pair effect together with an alternate hypothesis that may explain the dependence on light of responses by animals to magnetic field stimuli. PMID:20071390

A Field-Based Curriculum Model for Earth Science Teacher-Preparation Programs.

ERIC Educational Resources Information Center

Dubois, David D.

1979-01-01

This study proposed a model set of cognitive-behavioral objectives for field-based teacher education programs for earth science teachers. It describes field experience integration into teacher education programs. The model is also applicable for evaluation of earth science teacher education programs. (RE)

Laboratory and field investigations of marsh edge erosion

USDA-ARS?s Scientific Manuscript database

This chapter presents the laboratory experiments and field observations of marsh edge erosion. The marsh retreat rate in a field study site in Terrebonne Bay, Louisiana, was measured using GPS systems and aerial photographs. The wave environment was also measured in order to correlate the marsh edge...

Deformation of Water by a Magnetic Field

ERIC Educational Resources Information Center

Chen, Zijun; Dahlberg, E. Dan

2011-01-01

After the discovery that superconducting magnets could levitate diamagnetic objects, researchers became interested in measuring the repulsion of diamagnetic fluids in strong magnetic fields, which was given the name "The Moses Effect." Both for the levitation experiments and the quantitative studies on liquids, the large magnetic fields necessary…

Computational Studies of Magnetic Nozzle Performance

NASA Technical Reports Server (NTRS)

Ebersohn, Frans H.; Longmier, Benjamin W.; Sheehan, John P.; Shebalin, John B.; Raja, Laxminarayan

2013-01-01

An extensive literature review of magnetic nozzle research has been performed, examining previous work, as well as a review of fundamental principles. This has allow us to catalog all basic physical mechanisms which we believe underlie the thrust generation process. Energy conversion mechanisms include the approximate conservation of the magnetic moment adiabatic invariant, generalized hall and thermoelectric acceleration, swirl acceleration, thermal energy transformation into directed kinetic energy, and Joule heating. Momentum transfer results from the interaction of the applied magnetic field with currents induced in the plasma plume., while plasma detachment mechanisms include resistive diffusion, recombination and charge exchange collisions, magnetic reconnection, loss of adiabaticity, inertial forces, current closure, and self-field detachment. We have performed a preliminary study of Hall effects on magnetic nozzle jets with weak guiding magnetic fields and weak expansions (p(sub jet) approx. = P(sub background)). The conclusion from this study is that the Hall effect creates an azimuthal rotation of the plasma jet and, more generally, creates helical structures in the induced current, velocity field, and magnetic fields. We have studied plasma jet expansion to near vacuum without a guiding magnetic field, and are presently including a guiding magnetic field using a resistive MHD solver. This research is progressing toward the implementation of a full generalized Ohm's law solver. In our paper, we will summarize the basic principle, as well as the literature survey and briefly review our previous results. Our most recent results at the time of submittal will also be included. Efforts are currently underway to construct an experiment at the University of Michigan Plasmadynamics and Electric Propulsion Laboratory (PEPL) to study magnetic nozzle physics for a RF-thruster. Our computational study will work directly with this experiment to validate the numerical model, in order to study magnetic nozzle physics and optimize magnetic nozzle design. Preliminary results from the PEPL experiment will also be presented.

Effect of zero magnetic field on cardiovascular system and microcirculation

NASA Astrophysics Data System (ADS)

Gurfinkel, Yu. I.; At'kov, O. Yu.; Vasin, A. L.; Breus, T. K.; Sasonko, M. L.; Pishchalnikov, R. Yu.

2016-02-01

The effects of zero magnetic field conditions on cardiovascular system of healthy adults have been studied. In order to generate zero magnetic field, the facility for magnetic fields modeling ;ARFA; has been used. Parameters of the capillary blood flow, blood pressure, and the electrocardiogram (ECG) monitoring were measured during the study. All subjects were tested twice: in zero magnetic field and, for comparison, in sham condition. The obtained results during 60 minutes of zero magnetic field exposure demonstrate a clear effect on cardiovascular system and microcirculation. The results of our experiments can be used in studies of long-term stay in hypo-magnetic conditions during interplanetary missions.

Electric and magnetic fields and tumor progression. Final report

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

Keng, P.C.; Grota, L.J.; Michaelson, S.

This laboratory study has rigorously investigated two previously reported biological effects of 60-Hz electric and magnetic fields. The first effect involves nighttime suppression of melatonin synthesis in the pineal glands of rats exposed to high electric fields. The second concerns the increase in colony forming ability of human colon cancer cells exposed to 1.4-G magnetic fields. Neither effect was detected in the present study. A series of published laboratory studies on rats reported that 60-Hz electric fields at various field levels up to 130 kV/m suppress the nighttime synthesis of melatonin, a hormone produced by the pineal gland. Since melatoninmore » is known to modulate the immune system and may inhibit cancer cell activity, changes in physiological levels of melatonin may have significant health consequences. In the repeat experiments, field exposure did not alter nighttime levels of melatonin or enzyme activities in the pineal gland. A small but statistically significant reduction of about 20% in serum melatonin was seen in exposed animals. Pineal melatonin was also unaffected by the presence of red light as a cofactor with field exposure or by time-shifting the daily field exposure period. Another study reported that 60-Hz magnetic fields can affect the colony forming ability of human cancer cells after exposure in a culture medium. In the repeat experiments, field exposure did not alter the colony forming ability of human Colo 205 cells in two different cell concentrations at plating or in two different incubation conditions. Field exposure also did not affect cell cycling in any of the four cell lines tested.« less

THE URBAN DISPERSION PROGRAM ( UDP ) NYC MSG05 EXPERIMENT

EPA Science Inventory

The multi-organizational Urban Dispersion Program (UDP) has been conducting tracer release experiments at various locations within the United States. In March 2005 the UDP conducted the first NYC based experiment called Madison Square Garden -05 (MSG05). The field study involved ...

Model Errors in Simulating Precipitation and Radiation fields in the NARCCAP Hindcast Experiment

NASA Astrophysics Data System (ADS)

Kim, J.; Waliser, D. E.; Mearns, L. O.; Mattmann, C. A.; McGinnis, S. A.; Goodale, C. E.; Hart, A. F.; Crichton, D. J.

2012-12-01

The relationship between the model errors in simulating precipitation and radiation fields including the surface insolation and OLR, is examined from the multi-RCM NARCCAP hindcast experiment for the conterminous U.S. region. Findings in this study suggest that the RCM biases in simulating precipitation are related with those in simulating radiation fields. For a majority of RCMs participated in the NARCCAP hindcast experiment as well as their ensemble, the spatial pattern of the insolation bias is negatively correlated with that of the precipitation bias, suggesting that the biases in precipitation and surface insolation are systematically related, most likely via the cloud fields. The relationship varies according to seasons as well with stronger relationship between the simulated precipitation and surface insolation during winter. This suggests that the RCM biases in precipitation and radiation are related via cloud fields. Additional analysis on the RCM errors in OLR is underway to examine more details of this relationship.

Distinct regions of the hippocampus are associated with memory for different spatial locations.

PubMed

Jeye, Brittany M; MacEvoy, Sean P; Karanian, Jessica M; Slotnick, Scott D

2018-05-15

In the present functional magnetic resonance imaging (fMRI) study, we aimed to evaluate whether distinct regions of the hippocampus were associated with spatial memory for items presented in different locations of the visual field. In Experiment 1, during the study phase, participants viewed abstract shapes in the left or right visual field while maintaining central fixation. At test, old shapes were presented at fixation and participants classified each shape as previously in the "left" or "right" visual field followed by an "unsure"-"sure"-"very sure" confidence rating. Accurate spatial memory for shapes in the left visual field was isolated by contrasting accurate versus inaccurate spatial location responses. This contrast produced one hippocampal activation in which the interaction between item type and accuracy was significant. The analogous contrast for right visual field shapes did not produce activity in the hippocampus; however, the contrast of high confidence versus low confidence right-hits produced one hippocampal activation in which the interaction between item type and confidence was significant. In Experiment 2, the same paradigm was used but shapes were presented in each quadrant of the visual field during the study phase. Accurate memory for shapes in each quadrant, exclusively masked by accurate memory for shapes in the other quadrants, produced a distinct activation in the hippocampus. A multi-voxel pattern analysis (MVPA) of hippocampal activity revealed a significant correlation between behavioral spatial location accuracy and hippocampal MVPA accuracy across participants. The findings of both experiments indicate that distinct hippocampal regions are associated with memory for different visual field locations. Copyright © 2018 Elsevier B.V. All rights reserved.

Dynamic Modeling of the Madison Dynamo Experiment

NASA Astrophysics Data System (ADS)

Truitt, J. L.; Forest, C. B.; Wright, J. C.

1999-11-01

This work focuses on a computer simulation of the Magnetohydrodynamic equations applied in the geometry of the Madison Dynamo Experiemnt. An integration code is used to evolve both the magnetic field and the velocity field numerically in spherical coordinates using a pseudo-spectral algorithm. The focus is to realistically model an experiment to be undertaken by the Madison Dynamo Experiment Group. The first flows studied are the well documented ones of Dudley and James. The main goals of the simulation are to observe the dynamo effect with the back-reaction allowed, to observe the equipartition of magnetic and kinetic energy due to theoretically proposed turbulent effects, and to isolate and study the α and β effects.

Nuclear magnetic resonance studies of quadrupolar nuclei and dipolar field effects

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

Urban, Jeffry Todd

Experimental and theoretical research conducted in two areas in the field of nuclear magnetic resonance (NMR) spectroscopy is presented: (1) studies of the coherent quantum-mechanical control of the angular momentum dynamics of quadrupolar (spin I > 1/2) nuclei and its application to the determination of molecular structure; and (2) applications of the long-range nuclear dipolar field to novel NMR detection methodologies.The dissertation is organized into six chapters. The first two chapters and associated appendices are intended to be pedagogical and include an introduction to the quantum mechanical theory of pulsed NMR spectroscopy and the time dependent theory of quantum mechanics.more » The third chapter describes investigations of the solid-state multiple-quantum magic angle spinning (MQMAS) NMR experiment applied to I = 5/2 quadrupolar nuclei. This work reports the use of rotary resonance-matched radiofrequency irradiation for sensitivity enhancement of the I = 5/2 MQMAS experiment. These experiments exhibited certain selective line narrowing effects which were investigated theoretically.The fourth chapter extends the discussion of multiple quantum spectroscopy of quadrupolar nuclei to a mostly theoretical study of the feasibility of enhancing the resolution of nitrogen-14 NMR of large biomolecules in solution via double-quantum spectroscopy. The fifth chapter continues to extend the principles of multiple quantum NMR spectroscopy of quadrupolar nuclei to make analogies between experiments in NMR/nuclear quadrupolar resonance (NQR) and experiments in atomic/molecular optics (AMO). These analogies are made through the Hamiltonian and density operator formalism of angular momentum dynamics in the presence of electric and magnetic fields.The sixth chapter investigates the use of the macroscopic nuclear dipolar field to encode the NMR spectrum of an analyte nucleus indirectly in the magnetization of a sensor nucleus. This technique could potentially serve as an encoding module for the recently developed NMR remote detection experiment. The feasibility of using hyperpolarized xenon-129 gas as a sensor is discussed. This work also reports the use of an optical atomic magnetometer to detect the nuclear magnetization of Xe-129 gas, which has potential applicability as a detection module for NMR remote detection experiments.« less

Mercury monohalides: suitability for electron electric dipole moment searches.

PubMed

Prasannaa, V S; Vutha, A C; Abe, M; Das, B P

2015-05-08

Heavy polar diatomic molecules are the primary tools for searching for the T-violating permanent electric dipole moment of the electron (eEDM). Valence electrons in some molecules experience extremely large effective electric fields due to relativistic interactions. These large effective electric fields are crucial to the success of polar-molecule-based eEDM search experiments. Here we report on the results of relativistic ab initio calculations of the effective electric fields in a series of molecules that are highly sensitive to an eEDM, the mercury monohalides (HgF, HgCl, HgBr, and HgI). We study the influence of the halide anions on E_{eff}, and identify HgBr and HgI as attractive candidates for future electric dipole moment search experiments.

A magnetic field cloak for charged particle beams

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

Capobianco-Hogan, K. G.; Cervantes, R.; Deshpande, A.

Shielding charged particle beams from transverse magnetic fields is a common challenge for particle accelerators and experiments. In this study, we demonstrate that a magnetic field cloak is a viable solution. It allows for the use of dipole magnets in the forward regions of experiments at an Electron Ion Collider (EIC) and other facilities without interfering with the incoming beams. The dipoles can improve the momentum measurements of charged final state particles at angles close to the beam line and therefore increase the physics reach of these experiments. In contrast to other magnetic shielding options (such as active coils), amore » cloak requires no external powering. We discuss the design parameters, fabrication, and limitations of a magnetic field cloak and demonstrate that cylinders made from 45 layers of YBCO high-temperature superconductor, combined with a ferromagnetic shell made from epoxy and stainless steel powder, shield more than 99% of a transverse magnetic field of up to 0.45 T (95% shielding at 0.5 T) at liquid nitrogen temperature. Lastly, the ferromagnetic shell reduces field distortions caused by the superconductor alone by 90% at 0.45 T.« less

A magnetic field cloak for charged particle beams

DOE PAGES

Capobianco-Hogan, K. G.; Cervantes, R.; Deshpande, A.; ...

2017-10-02

Shielding charged particle beams from transverse magnetic fields is a common challenge for particle accelerators and experiments. In this study, we demonstrate that a magnetic field cloak is a viable solution. It allows for the use of dipole magnets in the forward regions of experiments at an Electron Ion Collider (EIC) and other facilities without interfering with the incoming beams. The dipoles can improve the momentum measurements of charged final state particles at angles close to the beam line and therefore increase the physics reach of these experiments. In contrast to other magnetic shielding options (such as active coils), amore » cloak requires no external powering. We discuss the design parameters, fabrication, and limitations of a magnetic field cloak and demonstrate that cylinders made from 45 layers of YBCO high-temperature superconductor, combined with a ferromagnetic shell made from epoxy and stainless steel powder, shield more than 99% of a transverse magnetic field of up to 0.45 T (95% shielding at 0.5 T) at liquid nitrogen temperature. Lastly, the ferromagnetic shell reduces field distortions caused by the superconductor alone by 90% at 0.45 T.« less

Accessible NMR Experiments Studying the Hydrodynamics of [subscript 15]N-Enriched Ubiquitin at Low Fields

ERIC Educational Resources Information Center

Thompson, Laura E.; Rovnyak, David

2007-01-01

We have recently developed and implemented two experiments in biomolecular NMR for an undergraduate-level biophysical chemistry laboratory with commercially available [subscript 15]N-enriched human ubiquitin. These experiments take advantage of [subscript 15]N direct detection of the NMR signal. The first experiment develops skills in acquiring…

Accessible NMR Experiments Studying the Hydrodynamics of [superscript 15]N-Enriched Ubiquitin at Low Fields

ERIC Educational Resources Information Center

Thompson, Laura E.; Rovnyak, David

2007-01-01

We have recently developed and implemented two experiments in biomolecular NMR for an undergraduate-level biophysical chemistry laboratory with commercially available [superscript 15]N-enriched human ubiquitin. These experiments take advantage of [superscript 15]N direct detection of the NMR signal. The first experiment develops skills in…

Physics of Hard Sphere Experiment: Scattering, Rheology and Microscopy Study of Colloidal Particles

NASA Technical Reports Server (NTRS)

Cheng, Z.-D.; Zhu, J.; Phan, S.-E.; Russel, W. B.; Chaikin, P. M.; Meyer, W. V.

2002-01-01

The Physics of Hard Sphere Experiment has two incarnations: the first as a scattering and rheology experiment on STS-83 and STS-94 and the second as a microscopy experiment to be performed in the future on LMM on the space station. Here we describe some of the quantitative and qualitative results from previous flights on the dynamics of crystallization in microgravity and especially the observed interaction of growing crystallites in the coexistance regime. To clarify rheological measurements we also present ground based experiments on the low shear rate viscosity and diffusion coefficient of several hard sphere experiments at high volume fraction. We also show how these experiments will be performed with confocal microscopy and laser tweezers in our lab and as preparation for the phAse II experiments on LMM. One of the main aims of the microscopy study will be the control of colloidal samples using an array of applied fields with an eye toward colloidal architectures. Temperature gradients, electric field gradients, laser tweezers and a variety of switchable imposed surface patterns are used toward this control.

Validation of design procedure and performance modeling of a heat and fluid transport field experiment in the unsaturated zone

NASA Astrophysics Data System (ADS)

Nir, A.; Doughty, C.; Tsang, C. F.

Validation methods which developed in the context of deterministic concepts of past generations often cannot be directly applied to environmental problems, which may be characterized by limited reproducibility of results and highly complex models. Instead, validation is interpreted here as a series of activities, including both theoretical and experimental tests, designed to enhance our confidence in the capability of a proposed model to describe some aspect of reality. We examine the validation process applied to a project concerned with heat and fluid transport in porous media, in which mathematical modeling, simulation, and results of field experiments are evaluated in order to determine the feasibility of a system for seasonal thermal energy storage in shallow unsaturated soils. Technical details of the field experiments are not included, but appear in previous publications. Validation activities are divided into three stages. The first stage, carried out prior to the field experiments, is concerned with modeling the relevant physical processes, optimization of the heat-exchanger configuration and the shape of the storage volume, and multi-year simulation. Subjects requiring further theoretical and experimental study are identified at this stage. The second stage encompasses the planning and evaluation of the initial field experiment. Simulations are made to determine the experimental time scale and optimal sensor locations. Soil thermal parameters and temperature boundary conditions are estimated using an inverse method. Then results of the experiment are compared with model predictions using different parameter values and modeling approximations. In the third stage, results of an experiment performed under different boundary conditions are compared to predictions made by the models developed in the second stage. Various aspects of this theoretical and experimental field study are described as examples of the verification and validation procedure. There is no attempt to validate a specific model, but several models of increasing complexity are compared with experimental results. The outcome is interpreted as a demonstration of the paradigm proposed by van der Heijde, 26 that different constituencies have different objectives for the validation process and therefore their acceptance criteria differ also.

Numerical modeling of laser-driven experiments aiming to demonstrate magnetic field amplification via turbulent dynamo

NASA Astrophysics Data System (ADS)

Tzeferacos, P.; Rigby, A.; Bott, A.; Bell, A. R.; Bingham, R.; Casner, A.; Cattaneo, F.; Churazov, E. M.; Emig, J.; Flocke, N.; Fiuza, F.; Forest, C. B.; Foster, J.; Graziani, C.; Katz, J.; Koenig, M.; Li, C.-K.; Meinecke, J.; Petrasso, R.; Park, H.-S.; Remington, B. A.; Ross, J. S.; Ryu, D.; Ryutov, D.; Weide, K.; White, T. G.; Reville, B.; Miniati, F.; Schekochihin, A. A.; Froula, D. H.; Gregori, G.; Lamb, D. Q.

2017-04-01

The universe is permeated by magnetic fields, with strengths ranging from a femtogauss in the voids between the filaments of galaxy clusters to several teragauss in black holes and neutron stars. The standard model behind cosmological magnetic fields is the nonlinear amplification of seed fields via turbulent dynamo to the values observed. We have conceived experiments that aim to demonstrate and study the turbulent dynamo mechanism in the laboratory. Here, we describe the design of these experiments through simulation campaigns using FLASH, a highly capable radiation magnetohydrodynamics code that we have developed, and large-scale three-dimensional simulations on the Mira supercomputer at the Argonne National Laboratory. The simulation results indicate that the experimental platform may be capable of reaching a turbulent plasma state and determining the dynamo amplification. We validate and compare our numerical results with a small subset of experimental data using synthetic diagnostics.

Gravitational Study of the Central Nervous System

NASA Technical Reports Server (NTRS)

Horowitz, J. M.

1983-01-01

A series of experiments conducted at 1G are discussed with reference to the role of calcium ions in information processing by the central nervous system. A technique is described which allows thin sections of a mammalian hippocampus to be isolated while maintaining neural activity. Two experiments carried out in hypergravic fields are also addressed; one investigating altered stimulation in the auditory system, the other determining temperature regulation responses in hypergravic fields.

Horse Manure and Other Fun Projects. Field Studies and Laboratory Experiences in Environmental Biology - A Book of Experimental Ideas for Secondary School Biology Teachers.

ERIC Educational Resources Information Center

Brown, Robert T., Ed.; Clark, Barbara G., Ed.

This guide contains a collection of laboratory and field inquiries designed to promote ecological awareness, sensitivity, and understanding. The activities compiled by 28 teachers are for use in teaching biology at the secondary level. They are presented in a "recipe" form to make it possible for teachers without prior experience or training to…

Further studies on the problems of geomagnetic field intensity determination from archaeological baked clay materials

NASA Astrophysics Data System (ADS)

Kostadinova-Avramova, M.; Kovacheva, M.

2015-10-01

Archaeological baked clay remains provide valuable information about the geomagnetic field in historical past, but determination of the geomagnetic field characteristics, especially intensity, is often a difficult task. This study was undertaken to elucidate the reasons for unsuccessful intensity determination experiments obtained from two different Bulgarian archaeological sites (Nessebar - Early Byzantine period and Malenovo - Early Iron Age). With this aim, artificial clay samples were formed in the laboratory and investigated. The clay used for the artificial samples preparation differs according to its initial state. Nessebar clay was baked in the antiquity, but Malenovo clay was raw, taken from the clay deposit near the site. The obtained artificial samples were repeatedly heated eight times in known magnetic field to 700 °C. X-ray diffraction analyses and rock-magnetic experiments were performed to obtain information about the mineralogical content and magnetic properties of the initial and laboratory heated clays. Two different protocols were applied for the intensity determination-Coe version of Thellier and Thellier method and multispecimen parallel differential pTRM protocol. Various combinations of laboratory fields and mutual positions of the directions of laboratory field and carried thermoremanence were used in the performed Coe experiment. The obtained results indicate that the failure of this experiment is probably related to unfavourable grain sizes of the prevailing magnetic carriers combined with the chosen experimental conditions. The multispecimen parallel differential pTRM protocol in its original form gives excellent results for the artificial samples, but failed for the real samples (samples coming from previously studied kilns of Nessebar and Malenovo sites). Obviously the strong dependence of this method on the homogeneity of the used subsamples hinders its implementation in its original form for archaeomaterials. The latter are often heterogeneous due to variable heating conditions in the different parts of the archaeological structures. The study draws attention to the importance of multiple heating for the stabilization of grain size distribution in baked clay materials and the need of elucidation of this question.

Supervision Challenges Encountered during Kenyan University Students' Practicum Attachment

ERIC Educational Resources Information Center

Kathuri-Ogola, Lucy; VanLeeuwen, Charlene; Kabaria-Muriithi, Joan; Weeks, Lori E.; Kieru, Jane; Ndayala, Phoebe

2015-01-01

There is little published research that examines the supervision experience of field attachment supervisors in Kenya. In this study, we identify the challenges encountered by field supervisors during student field attachments with community organizations. Fifteen organizations that had hosted third year students from the Department of Community…

Determining Student Competency in Field Placements: An Emerging Theoretical Model

ERIC Educational Resources Information Center

Salm, Twyla L.; Johner, Randy; Luhanga, Florence

2016-01-01

This paper describes a qualitative case study that explores how twenty-three field advisors, representing three human service professions including education, nursing, and social work, experience the process of assessment with students who are struggling to meet minimum competencies in field placements. Five themes emerged from the analysis of…

Walking the Talk: Towards a More Inclusive Field of Disability Studies

ERIC Educational Resources Information Center

Opini, Bathseba

2016-01-01

This paper is a conversation about growing an inclusive field of disability studies. The paper draws on data collected through an analysis of existing disability studies programmes in selected Canadian universities. The paper makes a case for including diverse perspectives, experiences, viewpoints, and voices in these programmes. In this work, I…

A Study of Children's Musical Preference: A Data Mining Approach

ERIC Educational Resources Information Center

Yim, Hoi Yin Bonnie; Boo, Yee Ling; Ebbeck, Marjory

2014-01-01

Musical preference has long been a research interest in the field of music education, and studies consistently confirm the importance of musical preference in one's musical learning experiences. However, only a limited number of studies have been focussed on the field of early childhood education (e.g., Hargreaves, North, & Tarrant, 2006;…

Testing neoclassical competitive market theory in the field.

PubMed

List, John A

2002-11-26

This study presents results from a pilot field experiment that tests predictions of competitive market theory. A major advantage of this particular field experimental design is that my laboratory is the marketplace: subjects are engaged in buying, selling, and trading activities whether I run an exchange experiment or am a passive observer. In this sense, I am gathering data in a natural environment while still maintaining the necessary control to execute a clean comparison between treatments. The main results of the study fall into two categories. First, the competitive model predicts reasonably well in some market treatments: the expected price and quantity levels are approximated in many market rounds. Second, the data suggest that market composition is important: buyer and seller experience levels impact not only the distribution of rents but also the overall level of rents captured. An unexpected result in this regard is that average market efficiency is lowest in markets that match experienced buyers and experienced sellers and highest when experienced buyers engage in bargaining with inexperienced sellers. Together, these results suggest that both market experience and market composition play an important role in the equilibrium discovery process.

Man and Society

ERIC Educational Resources Information Center

Lyons, Thomas T.

1972-01-01

Description of three years' experience with an interdisciplinary, field experience course, Man & Society," instituted at the Phillips Academy in 1970. It involved comparative societal study with a nine-week working and living experience in Boston and Mexico, a combination of student, teacher, and joint leadership, group discussion, and joint…

Convection Effects During Bulk Transparent Alloy Solidification in DECLIC-DSI and Phase-Field Simulations in Diffusive Conditions

NASA Astrophysics Data System (ADS)

Mota, F. L.; Song, Y.; Pereda, J.; Billia, B.; Tourret, D.; Debierre, J.-M.; Trivedi, R.; Karma, A.; Bergeon, N.

2017-08-01

To study the dynamical formation and evolution of cellular and dendritic arrays under diffusive growth conditions, three-dimensional (3D) directional solidification experiments were conducted in microgravity on a model transparent alloy onboard the International Space Station using the Directional Solidification Insert in the DEvice for the study of Critical LIquids and Crystallization. Selected experiments were repeated on Earth under gravity-driven fluid flow to evidence convection effects. Both radial and axial macrosegregation resulting from convection are observed in ground experiments, and primary spacings measured on Earth and microgravity experiments are noticeably different. The microgravity experiments provide unique benchmark data for numerical simulations of spatially extended pattern formation under diffusive growth conditions. The results of 3D phase-field simulations highlight the importance of accurately modeling thermal conditions that strongly influence the front recoil of the interface and the selection of the primary spacing. The modeling predictions are in good quantitative agreements with the microgravity experiments.

Effect of magnetic field on the phase transition in dusty plasma

NASA Astrophysics Data System (ADS)

Jaiswal, Surabhi; Thomas, Edward; Mukherjee, Rupak

2017-10-01

The formation of self-consistent crystalline structure is a well-known phenomenon in complex plasmas. In most experiments the pressure and rf power are the main controlling parameter in determining the phase of the system. We have studied the effect of externally applied magnetic field on the configuration of plasma crystals, suspended in the sheath of a radio-frequency discharge using the Magnetized Dusty Plasma Experiment (MDPX) device. Experiments are performed at a fixed pressure and rf power where a crystalline structure formed within the confining ring, but ramping the magnetic field up to 1.28 T. We report on the breakdown of the crystalline structure with increasing magnetic field. The magnetic field affects the dynamics of the plasma particles and first leads to a rotation of the crystal. At higher magnetic field, there is a radial variation (shear) in the angular velocity of the moving particles which we believe leads to the melting of the crystal. This melting is confirmed by evaluating the variation of the pair correlation function as a function of magnetic field. This work was supported by the US Dept. of Energy, DE - SC0010485.

A field study of wind over a simulated block building

NASA Technical Reports Server (NTRS)

Frost, W.; Shahabi, A. M.

1977-01-01

A full-scale field study of the wind over a simulated two-dimensional building is reported. The study develops an experiment to investigate the structure and magnitude of the wind fields. A description of the experimental arrangement, the type and expected accuracy of the data, and the range of the data are given. The data are expected to provide a fundamental understanding of mean wind and turbulence structure of the wind field around the bluff body. Preliminary analysis of the data demonstrates the reliability and completeness of the data in this regard.

Applying modeling Results in designing a global tropospheric experiment

NASA Technical Reports Server (NTRS)

1982-01-01

A set of field experiments and advanced modeling studies which provide a strategy for a program of global tropospheric experiments was identified. An expanded effort to develop space applications for trospheric air quality monitoring and studies was recommended. The tropospheric ozone, carbon, nitrogen, and sulfur cycles are addressed. Stratospheric-tropospheric exchange is discussed. Fast photochemical processes in the free troposphere are considered.

Behavioral Processes in Long-Lag Intervention Studies.

PubMed

Miller, Dale T; Dannals, Jennifer E; Zlatev, Julian J

2017-05-01

We argue that psychologists who conduct experiments with long lags between the manipulation and the outcome measure should pay more attention to behavioral processes that intervene between the manipulation and the outcome measure. Neglect of such processes, we contend, stems from psychology's long tradition of short-lag lab experiments where there is little scope for intervening behavioral processes. Studying process in the lab invariably involves studying psychological processes, but in long-lag field experiments it is important to study causally relevant behavioral processes as well as psychological ones. To illustrate the roles that behavioral processes can play in long-lag experiments we examine field experiments motivated by three policy-relevant goals: prejudice reduction, health promotion, and educational achievement. In each of the experiments discussed we identify various behavioral pathways through which the manipulated psychological state could have produced the observed outcome. We argue that if psychologists conducting long-lag interventions posited a theory of change that linked manipulated psychological states to outcomes via behavioral pathways, the result would be richer theory and more practically useful research. Movement in this direction would also permit more opportunities for productive collaborations between psychologists and other social scientists interested in similar social problems.

Responses of Study Abroad Students in Australia to Experience-Based Pedagogy in Sport Studies

ERIC Educational Resources Information Center

Light, Richard; Georgakis, Steve

2008-01-01

This paper contributes to research on the scholarship of teaching in the physical education/sport studies fields by examining the responses of study abroad students from overseas studying in Australia to a unit of study in sport studies that placed the interpretation of experience as the centre of the learning process. It draws on research…

The Current Situation of Field Experience in a Five-Year Science Teacher Education Program in Thailand

ERIC Educational Resources Information Center

Faikhamta, Chatree; Jantarakantee, Ekgapoom; Roadrangka, Vantipa

2011-01-01

This research explored the current situation in managing the field experience of a five-year science teacher education program in one university in Thailand. A number of methods were used to assess field experience situation: (1) a questionnaire on the perceptions of pre-service science teachers of field experience management; (2) participant…

Reviewing Special Education Teacher Preparation Field Experience Placements, Activities, and Research: Do We Know the Difference Maker?

ERIC Educational Resources Information Center

Nagro, Sarah A.; deBettencourt, Laurie U.

2017-01-01

There is a paucity of research on what constitutes an ideal special education field experience, and it is not clear which components or activities within a field experience impact a teacher's growth to the greatest extent. Reviewing past research will assist in categorizing the components typically included in field experiences and may assist in…

Interaction between Japanese flowering cherry trees and some wild animals observed during physiological experiment in fields

NASA Technical Reports Server (NTRS)

Nakamura, Teruko

2003-01-01

We have studied the weeping habit of Japanese flowering cherry tree in the field of Tama Forest Science Garden, Forestry and Forest Products Research Institute at the foot of Mt. Takao. Since cherry trees at various age were the materials for our plant physiology experiments, our studies were conducted in the fields where we experienced certain difficulties. Even under such difficult environment that was rather unexpected and uncontrollable, we could obtain fruitful results on the growth of cherry tree, and found them scientifically significant, especially in terms of biological effects of gravity on earth. Moreover, a lot of interesting interactions of cherry trees with various kinds of animals were observed in parallel to the plant physiology.

Momentum-resolved spectroscopy of a Fermi liquid

PubMed Central

Doggen, Elmer V. H.; Kinnunen, Jami J.

2015-01-01

We consider a recent momentum-resolved radio-frequency spectroscopy experiment, in which Fermi liquid properties of a strongly interacting atomic Fermi gas were studied. Here we show that by extending the Brueckner-Goldstone model, we can formulate a theory that goes beyond basic mean-field theories and that can be used for studying spectroscopies of dilute atomic gases in the strongly interacting regime. The model hosts well-defined quasiparticles and works across a wide range of temperatures and interaction strengths. The theory provides excellent qualitative agreement with the experiment. Comparing the predictions of the present theory with the mean-field Bardeen-Cooper-Schrieffer theory yields insights into the role of pair correlations, Tan's contact, and the Hartree mean-field energy shift. PMID:25941948

The Refugee Experience: Defining the Parameters of a Field of Study.

ERIC Educational Resources Information Center

Stein, Barry N.

1981-01-01

Reviews the stages of the refugee experience: perception of a threat; decision to flee; period of extreme danger and flight; reaching safety; camp behavior; repatriation; settlement or resettlement; adjustment and acculturation; and residual states and changes in behavior caused by the experience. (Author/MK)

The "Lived Experience" of Political Engagement.

ERIC Educational Resources Information Center

Hildreth, R. W.

For faculty members who incorporate experiential or service learning pedagogies into their courses, student experiences in the field can be difficult, emotionally charged, and full of unexpected outcomes. This paper presents the findings from a qualitative study of student lived experiences in the political science course "Democracy and…

The Effects of In-Nature and Virtual-Nature Field Trip Experiences On Proenvironmental Attitudes and Behaviors, And Environmental Knowledge Of Middle School Students

NASA Astrophysics Data System (ADS)

Ferderbar, Catherine A.

To develop sustainable solutions to remediate the complex ecological problems of earth's soil, water, and air degradation requires the talents and skills of knowledgeable, motivated people (UNESCO, 1977; UNESCO, 2010). Researchers historically emphasized that time spent in outdoor, nature activities (Wells & Lekies, 2006), particularly with an adult mentor (Chawla & Cushing, 2007), promotes environmental knowledge and nature-relatedness, precursors to environmental literacy. Research has also demonstrated that technology is integral to the lives of youth, who spend 7:38 hours daily (Rideout, et al., 2010), engaged in electronics. Educators would benefit from knowing if in-nature and virtual-nature field trip experiences provide comparable levels of knowledge and connectedness, to nurture student proenvironmentalism. To investigate field trip phenomena, the researcher studied the impact of virtual-nature and in-nature experiences during which students analyzed water quality along Midwestern rivers. The quasi-experimental, mixed method convergent parallel design with a purposeful sample (n=131) of middle school students from two Midwestern K-8 schools, utilized scientist participant observer field records and narrative response, written assessment aligned to field trip content to evaluate knowledge acquisition. To gain insight into student environmental dispositions, participant observers recorded student comments and behaviors throughout field trips. A survey, administered Pre-Treatment, Post-Treatment 1 and Post-Treatment 2, focused on family water-related behaviors and student perceptions of the need for local government water protection. The findings demonstrated both field trips increased content knowledge significantly, with large effect size. Content knowledge gain from one experience transferred to and was augmented by the second experience. Skill gain (technical and observational) varied by type of field trip and did not transfer. Technical skill was often paired with critical thinking/reasoning. Survey results demonstrated that the virtual-nature, in-nature order evinced a greater proenvironmental attitude and behavioral change. The initial experience provided greater proenvironmental impact, regardless of order. Several students exhibited a Connection to Life Experience that reinforced their nature-relatedness during either field trip. These findings inform best practices associated with environmental education. The implications include teacher-practitioner collaboration with IT personnel, naturalists, hydrologists, zoological and botanical experts, to design local, site-based virtual-nature and in-nature (or hybrid) field trips to nurture environmental literacy goals.

Vacuum Magnetic Field Mapping of the Compact Toroidal Hybrid (CTH)

NASA Astrophysics Data System (ADS)

Peterson, J. T.; Hanson, J.; Hartwell, G. J.; Knowlton, S. F.; Montgomery, C.; Munoz, J.

2007-11-01

Vacuum magnetic field mapping experiments are performed on the CTH torsatron with a movable electron gun and phosphor-coated screen or movable wand at two different toroidal locations. These experiments compare the experimentally measured magnetic configuration produced by the as-built coil set, to the magnetic configuration simulated with the IFT Biot-Savart code using the measured coil set parameters. Efforts to minimize differences between the experimentally measured location of the magnetic axis and its predicted value utilizing a Singular Value Decomposition (SVD) process result in small modifications of the helical coil winding law used to model the vacuum magnetic field geometry of CTH. Because these studies are performed at relatively low fields B = 0.01 - 0.05 T, a uniform ambient magnetic field is included in the minimization procedure.

Fast-Turnoff Transient Electromagnetic (TEM) Field Study at the Mars Analog Site of Rio Tinto, Spain

NASA Astrophysics Data System (ADS)

Jernsletten, J. A.

2005-03-01

This report describes a Fast-Turnoff Transient Electromagnetic (TEM) study at the Peña de Hierro ("Berg of Iron") field area of the Mars Analog Research and Technology Experiment (MARTE), near the towns Rio Tinto and Nerva, Andalucia region, Spain.

Personality and Field of Study Choice in University

ERIC Educational Resources Information Center

Humburg, Martin

2017-01-01

This paper demonstrates that the Big five personality traits (openness to experience, conscientiousness, extraversion, agreeableness, and emotional stability) measured at age 14 can be linked to field of study choice in university at around age 19. While personality matters less than cognitive skills, such as math ability and verbal ability, for…

Early Field Experience in Career and Technical Education

ERIC Educational Resources Information Center

Smalley, Scott Walter

2011-01-01

The purpose of the three studies in this dissertation was to enhance career and technical education in the area of agriculture, business, and family and consumer sciences. This dissertation contains three papers: (1) a Delphi study identifying the purpose, expected outcomes, and methods of documenting preservice teacher early field experience…

Measuring and Enhancing Creativity

ERIC Educational Resources Information Center

Mahboub, Kamyar C.; Portillo, Margaret B.; Liu, Yinhui; Chandraratna, Susantha

2004-01-01

The purpose of this study was to assess ways by which creativity may be enhanced in a design-oriented course. In order to demonstrate the validity of the approach, a statistically based study was employed. Additionally, the experiment was replicated in two design-oriented fields at the University of Kentucky. These fields were civil engineering…

Emotional Reactions of Students in Field Education: An Exploratory Study

ERIC Educational Resources Information Center

Litvack, Andrea; Mishna, Faye; Bogo, Marion

2010-01-01

An exploratory study using qualitative methodology was undertaken with recent MSW graduates (N=12) from 2 graduate social work programs to identify and describe the students' emotional reactions to experiences in field education. Significant and interrelated themes emerged including the subjective and unique definitions of emotionally charged…

The context of employment discrimination: interpreting the findings of a field experiment.

PubMed

Midtbøen, Arnfinn H

2015-03-01

Although field experiments have documented the contemporary relevance of discrimination in employment, theories developed to explain the dynamics of differential treatment cannot account for differences across organizational and institutional contexts. In this article, I address this shortcoming by presenting the main empirical findings from a multi-method research project, in which a field experiment of ethnic discrimination in the Norwegian labour market was complemented with forty-two in-depth interviews with employers who were observed in the first stage of the study. While the experimental data support earlier findings in documenting that ethnic discrimination indeed takes place, the qualitative material suggests that theorizing in the field experiment literature have been too concerned with individual and intra-psychic explanations. Discriminatory outcomes in employment processes seems to be more dependent on contextual factors such as the number of applications received, whether requirements are specified, and the degree to which recruitment procedures are formalized. I argue that different contexts of employment provide different opportunity structures for discrimination, a finding with important theoretical and methodological implications. © London School of Economics and Political Science 2014.

Rapid-onset/offset, variably scheduled 60 Hz electric and magnetic field exposure reduces nocturnal serum melatonin concentration in nonhuman primates

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

Rogers, W.R.; Smith, H.D.; Reiter, R.J.

Experiments with rodents indicate that power-frequency electric field (EF) or magnetic field (MF) exposure can suppress the normal nocturnal increase in melatonin concentration in pineal gland and blood. In a separate set of three experiments conducted with nonhuman primates, the authors did not observe melatonin suppression as a result of 6 weeks of day-time exposure to combined 60 Hz electric and magnetic fields (E/MF) with regularly schedule ``slow`` E/MF onsets/offsets. The study described here used a different exposure paradigm in which two baboons were exposed to E/MF with ``rapid`` E/MF onsets/offsets accompanied by EF transients not found with slowly rampedmore » E/MF onset/offset; profound reductions in nocturnal serum melatonin concentration were observed in this experiment. If replicated in a more extensive experiment, the observation of melatonin suppression only in the presence of E/MF transients would suggest that very specific exposure parameters determine the effects of 60 Hz E/MF on melatonin.« less

Einstein's Elevator in Class: A Self-Construction by Students for the Study of the Equivalence Principle

NASA Astrophysics Data System (ADS)

Kapotis, Efstratios; Kalkanis, George

2016-10-01

According to the principle of equivalence, it is impossible to distinguish between gravity and inertial forces that a noninertial observer experiences in his own frame of reference. For example, let's consider an elevator in space that is being accelerated in one direction. An observer inside it would feel as if there was gravity force pulling him toward the opposite direction. The same holds for a person in a stationary elevator located in Earth's gravitational field. No experiment enables us to distinguish between the accelerating elevator in space and the motionless elevator near Earth's surface. Strictly speaking, when the gravitational field is non-uniform (like Earth's), the equivalence principle holds only for experiments in elevators that are small enough and that take place over a short enough period of time (Fig. 1). However, performing an experiment in an elevator in space is impractical. On the other hand, it is easy to combine both forces on the same observer, i.e., gravity and a fictitious inertial force due to acceleration. Imagine an observer in an elevator that falls freely within Earth's gravitational field. The observer experiences gravity pulling him down while it might be said that the inertial force due to gravity acceleration g pulls him up. Gravity and inertial force cancel each other, (mis)leading the observer to believe there is no gravitational field. This study outlines our implementation of a self-construction idea that we have found useful in teaching introductory physics students (undergraduate, non-majors).

How does audit and feedback influence intentions of health professionals to improve practice? A laboratory experiment and field study in cardiac rehabilitation.

PubMed

Gude, Wouter T; van Engen-Verheul, Mariëtte M; van der Veer, Sabine N; de Keizer, Nicolette F; Peek, Niels

2017-04-01

To identify factors that influence the intentions of health professionals to improve their practice when confronted with clinical performance feedback, which is an essential first step in the audit and feedback mechanism. We conducted a theory-driven laboratory experiment with 41 individual professionals, and a field study in 18 centres in the context of a cluster-randomised trial of electronic audit and feedback in cardiac rehabilitation. Feedback reports were provided through a web-based application, and included performance scores and benchmark comparisons (high, intermediate or low performance) for a set of process and outcome indicators. From each report participants selected indicators for improvement into their action plan. Our unit of observation was an indicator presented in a feedback report (selected yes/no); we considered selecting an indicator to reflect an intention to improve. We analysed 767 observations in the laboratory experiment and 614 in the field study, respectively. Each 10% decrease in performance score increased the probability of an indicator being selected by 54% (OR, 1.54; 95% CI 1.29% to 1.83%) in the laboratory experiment, and 25% (OR, 1.25; 95% CI 1.13% to 1.39%) in the field study. Also, performance being benchmarked as low and intermediate increased this probability in laboratory settings. Still, participants ignored the benchmarks in 34% (laboratory experiment) and 48% (field study) of their selections. When confronted with clinical performance feedback, performance scores and benchmark comparisons influenced health professionals' intentions to improve practice. However, there was substantial variation in these intentions, because professionals disagreed with benchmarks, deemed improvement unfeasible or did not consider the indicator an essential aspect of care quality. These phenomena impede intentions to improve practice, and are thus likely to dilute the effects of audit and feedback interventions. NTR3251, pre-results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Engaging students in research learning experiences through hydrology field excursions and projects

NASA Astrophysics Data System (ADS)

Ewen, T.; Seibert, J.

2014-12-01

One of the best ways to engage students and instill enthusiasm for hydrology is to expose them to hands-on learning. A focus on hydrology field research can be used to develop context-rich and active learning, and help solidify idealized learning where students are introduced to individual processes through textbook examples, often neglecting process interactions and an appreciation for the complexity of the system. We introduced a field course where hydrological measurement techniques are used to study processes such as snow hydrology and runoff generation, while also introducing students to field research and design of their own field project. In the field projects, students design a low-budget experiment with the aim of going through the different steps of a 'real' scientific project, from formulating the research question to presenting their results. In one of the field excursions, students make discharge measurements in several alpine streams with a salt tracer to better understand the spatial characteristics of an alpine catchment, where source waters originate and how they contribute to runoff generation. Soil moisture measurements taken by students in this field excursion were used to analyze spatial soil moisture patterns in the alpine catchment and subsequently used in a publication. Another field excursion repeats a published experiment, where preferential soil flow paths are studied using a tracer and compared to previously collected data. For each field excursion, observational data collected by the students is uploaded to an online database we developed, which also allows students to retrieve data from past excursions to further analyze and compare their data. At each of the field sites, weather stations were installed and a webviewer allows access to realtime data from data loggers, allowing students to explore how processes relate to climatic conditions. With in-house film expertise, these field excursions were also filmed and short virtual excursions were produced, which we plan to use in a large introductory course, exposing students to field research at an early stage.

Measuring Instructional Differentiation in a Large-Scale Experiment

ERIC Educational Resources Information Center

Williams, Ryan T.; Swanlund, Andrew; Miller, Shazia; Konstantopoulos, Spyros; Eno, Jared; van der Ploeg, Arie; Meyers, Coby

2014-01-01

This study operationalizes four measures of instructional differentiation: one for Grade 2 English language arts (ELA), one for Grade 2 mathematics, one for Grade 5 ELA, and one for Grade 5 mathematics. Our study evaluates their measurement properties of each measure in a large field experiment: the Indiana Diagnostic Assessment Tools Study, which…

Research-infused K-12 Science at the "Uttermost Part of the Earth:" An NSF GK-12 Fellow's Perspective

NASA Astrophysics Data System (ADS)

Perry, E.; Ellins, K.; Ormiston, C.; Dovzak, N.; Anderson, S.; Tingle, D.; Knettel, P.; Redding, S.; Odle, K.; Dalziel, I.

2005-12-01

In March 2005, four students and three teachers from Boerne High School in Texas accompanied UTIG GK-12 Co-PIs Katherine Ellins and Ian Dalziel, and NSF GK-12 Fellow Ethan Perry to Tierra del Fuego to join an international team of scientists studying the climate-tectonic history recorded in Lago Fagnano, Tierra del Fuego, Argentina. For two weeks, students and teachers engaged in authentic scientific research that included geologic field mapping and reconnaissance, and student/teacher developed water and soils sampling routines. The Lago Fagnano experience enabled: (1) the Boerne High School group to be integrated into an active field research program and to bring tangible experiences, knowledge and high-quality data back to the classroom; (2) participating research scientists to convey the importance of their science to a wider audience; and (3) the NSF GK-12 Fellow to gain valuable experience in communicating the essential scientific knowledge and field skills to high school participants before field deployment. The GK-12 Fellow's bridging role through the course of the project enhanced his scientific understanding of the climate-tectonic setting of Tierra del Fuego, fostered the development of new professional contacts with research scientists and led to a fresh perspective on how research science can be integrated in high school science curriculum. The GK-12 Fellow served as the primary mentor to the K-12 participants and the liaison between UTIG research scientists and the Boerne High School group. The Fellow helped prepare the Boerne group for the field research experience and to design a research project using water and soil analyses to assess chemical and isotopic trends within the lake's watershed. Preparatory activities began three months prior to field deployment and included workshops, classroom visits and teleconferences aimed at teaching field skills (reading and creating geologic maps, compass measurements, GPS, field notebooks) and increasing participants' knowledge of geoscience concepts and regional tectonics. The Fellow blended inquiry- and discussion-based exercises to convey the relevance of the Lago Fagnano research. Interaction between the GK-12 Fellow and Boerne High School participants preceding, during and following the field experience was an important element in the success of this research experience for teachers and their students. This interaction benefited the high school students and teachers because they were able to grasp the fundamental goals of the research experience prior to arriving in the field, thereby ensuring that the time spent in the field was used efficiently to carry out the project. Long-term involvement in the planning, execution and synthesis of the experience provided the high school participants with a sense of ownership of the science conducted on Lago Fagnano. This field initiative represents the first time that both K-12 students and teachers were integrated into a field setting with UTIG research scientists. Such experiences are valuable because they demonstrate the true manner in which science is conducted and advance partnerships between university research institutions and K-12 schools. The level of mentoring that the GK-12 Fellow provided through all stages of the project maximized the potential benefits of such an experience.

Studying Abroad as a Sorting Criterion in the Recruitment Process: A Field Experiment among German Employers

ERIC Educational Resources Information Center

Petzold, Knut

2017-01-01

As the experience of studying abroad can signal general and transnational human capital, it is considered to be increasingly important for professional careers, particularly in the context of economies' internationalization. However, studies using graduate surveys face problems of self-selection and studies on employers' opinions face problems of…

Using Natural Experiments to Study the Impact of Media on the Family

ERIC Educational Resources Information Center

Price, Joseph; Dahl, Gordon B.

2012-01-01

The randomized trial is the gold standard in scientific research and is used by several fields to study the effects of media. Although useful for studying the immediate response to media exposure, the experimental approach is not well suited to studying long-term effects or behavior outside the laboratory. The "natural experiment" approach, a…

Learning on Zoo Field Trips: The Interaction of the Agendas and Practices of Students, Teachers, and Zoo Educators

ERIC Educational Resources Information Center

Davidson, Susan Kay; Passmore, Cynthia; Anderson, David

2010-01-01

This paper reports on the findings of a case study that investigated the interaction of the agendas and practices of students, teachers, and zoo educators during a class field trip to a zoo. The study reports on findings of the analysis of two case classes of students and their perceptions of their learning experiences during the field trip. The…

International Mobility of Australian University Students: 2005

ERIC Educational Resources Information Center

Olsen, Alan

2008-01-01

Australia as a destination for international students is well researched. However, less is known about the numbers of Australian students who undertake international study experiences during their courses, the characteristics of those students, their types of experiences, their fields of education, and their destinations. This study finds that…

Untangling the effects of root age and tissue nitrogen on root respiration in Populus tremuloides at different nitrogen supply.

PubMed

Ceccon, Christian; Tagliavini, Massimo; Schmitt, Armin Otto; Eissenstat, David M

2016-05-01

Root respiration is a major contributor to terrestrial carbon flux. Many studies have shown root respiration to increase with an increase in root tissue nitrogen (N) concentration across species and study sites. Studies have also shown that both root respiration and root N concentration typically decrease with root age. The effects of added N may directly increase respiration of existing roots or may affect respiration by shifting the age structure of a root population by stimulating growth. To the best of our knowledge, no study has ever examined the effect of added N as a function of root age on root respiration. In this study, root respiration of 13-year-old Populus tremuloides Michx. trees grown in the field and 1-year-old P. tremuloides seedlings grown in containers was analyzed for the relative influence of root age and root N concentration independent of root age on root respiration. Field roots were first tracked using root windows and then sampled at known age. Nitrogen was either applied or not to small patches beneath the windows. In a pot experiment, each plant was grown with its root system split between two separate pots and N was applied at three different levels, either at the same or at different rates between pots. Root N concentration ranged between 1.4 and 1.7% in the field experiment and 1.8 and 2.6% in the seedling experiment. We found that addition of N increased root N concentration of only older roots in the field but of roots of all ages in the potted seedlings. In both experiments, the age-dependent decline in root respiration was largely consistent, and could be explained by a negative power function. Respiration decreased ∼50% by 3 weeks of age. Although root age was the dominant factor affecting respiration in both experiments, in the field experiment, root N also contributed to root respiration independent of root age. These results add further insight into respiratory responses of roots to N addition and mechanisms underlying the tissue N-respiration relationship. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Microwave platform as a valuable tool for characterization of nanophotonic devices

PubMed Central

Shishkin, Ivan; Baranov, Dmitry; Slobozhanyuk, Alexey; Filonov, Dmitry; Lukashenko, Stanislav; Samusev, Anton; Belov, Pavel

2016-01-01

The rich potential of the microwave experiments for characterization and optimization of optical devices is discussed. While the control of the light fields together with their spatial mapping at the nanoscale is still laborious and not always clear, the microwave setup allows to measure both amplitude and phase of initially determined magnetic and electric field components without significant perturbation of the near-field. As an example, the electromagnetic properties of an add-drop filter, which became a well-known workhorse of the photonics, is experimentally studied with the aid of transmission spectroscopy measurements in optical and microwave ranges and through direct mapping of the near fields at microwave frequencies. We demonstrate that the microwave experiments provide a unique platform for the comprehensive studies of electromagnetic properties of micro- and nanophotonic devices, and allow to obtain data which are hardly acquirable by conventional optical methods. PMID:27759058

A table top experiment to study plasma confined by a dipole magnet

NASA Astrophysics Data System (ADS)

Bhattacharjee, Sudeep; Baitha, Anuj Ram

2016-10-01

There has been a long quest to understand charged particle generation, confinement and underlying complex processes in a plasma confined by a dipole magnet. Our earth's magnetosphere is an example of such a naturally occurring system. A few laboratory experiments have been designed for such investigations, such as the Levitated Dipole Experiment (LDX) at MIT, the Terella experiment at Columbia university, and the Ring Trap-1 (RT-1) experiment at the University of Tokyo. However, these are large scale experiments, where the dipole magnetic field is created with superconducting coils, thereby, necessitating power supplies and stringent cryogenic requirements. We report a table top experiment to investigate important physical processes in a dipole plasma. A strong cylindrical permanent magnet, is employed to create the dipole field inside a vacuum chamber. The magnet is suspended and cooled by circulating chilled water. The plasma is heated by electromagnetic waves of 2.45 GHz and a second frequency in the range 6 - 11 GHz. Some of the initial results of measurements and numerical simulation of magnetic field, visual observations of the first plasma, and spatial measurements of plasma parameters will be presented.

Hospital graduate social work field work programs: a study in New York City.

PubMed

Showers, N

1990-02-01

Twenty-seven hospital field work programs in New York City were studied. Questionnaires were administered to program coordinators and 238 graduate social work students participating in study programs. High degrees of program structural complexity and variation were found, indicating a state of art well beyond that described in the general field work literature. High rates of student satisfaction with learning, field instructors, programs, and the overall field work experience found suggest that the complexity of study programs may be more effective than traditional field work models. Statistically nonsignificant study findings indicate areas in which hospital social work departments may develop field work programs consistent with shifting organizational needs, without undue risk to educational effectiveness. Statistically significant findings suggest areas in which inflexibility in program design may be more beneficial in the diagnostic related groups era.

LABORATORY AND FIELD STUDIES TO EVALUATE RISKS TO LARVAL FISH FROM PHOTO-ACTIVATED TOXICITY OF PAHS

EPA Science Inventory

Hazard from photo-activation of PAHs has been well documented in aquatic organisms. Far less certain is the degree to which risk actually occurs in the field. This presentation outlines a series of laboratory and field experiments conducted to better understand the dosimetry and ...

The Mu2e Solenoid Cold Mass Position Monitor System

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

Strauss, Thomas; Feher, Sandor; Friedsam, Horst W.

The Mu2e experiment at Fermilab is designed to search for charged-lepton flavor violation by looking for muon to electron conversions in the field of the nucleus. The concept of the experiment is to generate a low momentum muon beam, stopping the muons in a target and measuring the momentum of the outgoing electrons. The implementation of this approach utilizes a complex magnetic field composed of graded solenoidal and toroidal fields. The location of the solenoid cold mass relative to external fiducials is needed for alignment as well as monitoring coil movements during cool down and magnet excitation. This study describesmore » a novel design of a Cold Mass Position Monitor System (CMPS) that will be implemented for the Mu2e experiment.« less

The Mu2e Solenoid Cold Mass Position Monitor System

DOE PAGES

Strauss, Thomas; Feher, Sandor; Friedsam, Horst W.; ...

2018-01-23

The Mu2e experiment at Fermilab is designed to search for charged-lepton flavor violation by looking for muon to electron conversions in the field of the nucleus. The concept of the experiment is to generate a low momentum muon beam, stopping the muons in a target and measuring the momentum of the outgoing electrons. The implementation of this approach utilizes a complex magnetic field composed of graded solenoidal and toroidal fields. The location of the solenoid cold mass relative to external fiducials is needed for alignment as well as monitoring coil movements during cool down and magnet excitation. This study describesmore » a novel design of a Cold Mass Position Monitor System (CMPS) that will be implemented for the Mu2e experiment.« less

Using Mobile Devices to Connect Teachers and Museum Educators

NASA Astrophysics Data System (ADS)

Delen, Ibrahim; Krajcik, Joseph

2017-06-01

The use of mobile devices is increasing rapidly as a potential tool for science teaching. In this study, five educators (three middle school teachers and two museum educators) used a mobile application that supported the development of a driving question. Previous studies have noted that teachers make little effort to connect learning experiences between classrooms and museums, and few studies have focused on creating connections between teachers and museum educators. In this study, teachers and museum educators created an investigation together by designing a driving question in conjunction with the research group before field trips. During field trips, students collected their own data using iPods or iPads to take pictures or record videos of the exhibits. When students returned to the school, they used the museum data with their peers as they tried to answer the driving question. After completing the field trips, five educators were interviewed to investigate their experiences with designing driving questions and using mobile devices. Besides supporting students in data collection during the field trip, using mobile devices helped teachers to get the museum back to the classroom. Designing the driving question supported museum educators and teachers to plan the field trip collaboratively.

Reducing firing of an early pottery making kiln at Batán Grande, Peru: A Mössbauer study

NASA Astrophysics Data System (ADS)

Wagner, U.; Gebhard, R.; Häusler, W.; Hutzelmann, T.; Riederer, J.; Shimada, I.; Sosa, J.; Wagner, F. E.

1999-11-01

Material from field firing experiments using a 2,700-year old Formative kiln at Batán Grande, Peru, was studied by X-ray diffraction and Mössbauer spectroscopy. The experiments explore the technology involved in producing the gray and black reduced ware for which Cupisnique and other Formative ceramics are justly known. During firing, the iron-bearing compounds in clays undergo characteristic changes which depend on kiln temperature and atmosphere. These changes can be observed in the Mössbauer spectra. By comparing spectra of an appropriate clay fired in field experiments and in the laboratory with the spectra of ancient ceramics, a description of Formative firing techniques in a reducing environment is attempted.

Equilibrium features and eruptive instabilities in laboratory magnetic flux rope plasmas

NASA Astrophysics Data System (ADS)

Myers, Clayton E; Yamada, Masaaki; Belova, Elena V; Ji, Hantao; Yoo, Jongsoo; Fox, William

2014-06-01

One avenue for connecting laboratory and solar plasma studies is to carry out laboratory plasma experiments that serve as a well-diagnosed model for specific solar phenomena. In this paper, we present the latest results from one such laboratory experiment that is designed to address ideal instabilities that drive flux rope eruptions in the solar corona. The experiment, which utilizes the existing Magnetic Reconnection Experiment (MRX) at Princeton Plasma Physics Laboratory, generates a quasi-statically driven line-tied magnetic flux rope in a solar-relevant potential field arcade. The parameters of the potential field arcade (e.g., its magnitude, orientation, and vertical profile) are systematically scanned in order to study their influence on the evolution and possible eruption of the line-tied flux rope. Each flux rope discharge is diagnosed using a combination of fast visible light cameras and an in situ 2D magnetic probe array that measures all three components of the magnetic field over a large cross-section of the plasma. In this paper, we present the first results obtained from this new 2D magnetic probe array. With regard to the flux rope equilibrium, non-potential features such as the formation of a characteristic sigmoid shape and the generation of core toroidal field within the flux rope are studied in detail. With regard to instabilities, the onset and evolution of two key eruptive instabilities—the kink and torus instabilities—are quantitatively assessed as a function of the potential field arcade parameters and the amount of magnetic energy stored in the flux rope.This research is supported by DoE Contract Number DE-AC02-09CH11466 and by the NSF/DoE Center for Magnetic Self-Organization (CMSO).

Promising Practices in Small High Schools. A Report of 15 Northwest Projects.

ERIC Educational Resources Information Center

Northwest Regional Educational Lab., Portland, OR.

Promising methods utilized in small rural high schools to provide a wider range of experiences for students are identified and described. Programs reported on include the Arctic Nursing Program, Career Research Program, Contractual Study Program, Eye-opening Experience, Field Experience Program, Guitar and Folk Music Program, Individualized…

Teacher Candidates and Latina/o English Learners at Fenton Elementary School: The Role of Early Clinical Experiences in Urban Teacher Education

ERIC Educational Resources Information Center

Nasir, Ambareen; Heineke, Amy J.

2014-01-01

This study investigates how early clinical experiences impact teacher candidates' learning and experiences with Latina/o English learners in a field-based program housed in a multilingual, urban elementary school. We draw on multiple-case study design and use discourse analysis to explore cases of three candidates. Findings reveal exploration of…

Chameleon fragmentation

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

Brax, Philippe; Upadhye, Amol, E-mail: philippe.brax@cea.fr, E-mail: aupadhye@anl.gov

2014-02-01

A scalar field dark energy candidate could couple to ordinary matter and photons, enabling its detection in laboratory experiments. Here we study the quantum properties of the chameleon field, one such dark energy candidate, in an ''afterglow'' experiment designed to produce, trap, and detect chameleon particles. In particular, we investigate the possible fragmentation of a beam of chameleon particles into multiple particle states due to the highly non-linear interaction terms in the chameleon Lagrangian. Fragmentation could weaken the constraints of an afterglow experiment by reducing the energy of the regenerated photons, but this energy reduction also provides a unique signaturemore » which could be detected by a properly-designed experiment. We show that constraints from the CHASE experiment are essentially unaffected by fragmentation for φ{sup 4} and 1/φ potentials, but are weakened for steeper potentials, and we discuss possible future afterglow experiments.« less

Effect of Field Trip on Students' Academic Performance in Basic Technology in Ilorin Metropolis, Nigeria

ERIC Educational Resources Information Center

Amosa, Abdul Ganiyu Alasela; Ogunlade, Oyeronke Olufunmilola; Atobatele, Adunni Suliat

2015-01-01

The use of field trip in teaching and learning helps to bring about effective and efficient learning in Basic Technology. Field trip is a group excursion away from the normal education environment for firsthand experience of an historic site or place of special interest. This study therefore was geared towards finding out the effect of field trip…

Science objectives of the magnetic field experiment onboard Aditya-L1 spacecraft

NASA Astrophysics Data System (ADS)

Yadav, Vipin K.; Srivastava, Nandita; Ghosh, S. S.; Srikar, P. T.; Subhalakshmi, Krishnamoorthy

2018-01-01

The Aditya-L1 is first Indian solar mission scheduled to be placed in a halo orbit around the first Lagrangian point (L1) of Sun-Earth system in the year 2018-19. The approved scientific payloads onboard Aditya-L1 spacecraft includes a Fluxgate Digital Magnetometer (FGM) to measure the local magnetic field which is necessary to supplement the outcome of other scientific experiments onboard. The in-situ vector magnetic field data at L1 is essential for better understanding of the data provided by the particle and plasma analysis experiments, onboard Aditya-L1 mission. Also, the dynamics of Coronal Mass Ejections (CMEs) can be better understood with the help of in-situ magnetic field data at the L1 point region. This data will also serve as crucial input for the short lead-time space weather forecasting models. The proposed FGM is a dual range magnetic sensor on a 6 m long boom mounted on the Sun viewing panel deck and configured to deploy along the negative roll direction of the spacecraft. Two sets of sensors (tri-axial each) are proposed to be mounted, one at the tip of boom (6 m from the spacecraft) and other, midway (3 m from the spacecraft). The main science objective of this experiment is to measure the magnitude and nature of the interplanetary magnetic field (IMF) locally and to study the disturbed magnetic conditions and extreme solar events by detecting the CME from Sun as a transient event. The proposed secondary science objectives are to study the impact of interplanetary structures and shock solar wind interaction on geo-space environment and to detect low frequency plasma waves emanating from the solar corona at L1 point. This will provide a better understanding on how the Sun affects interplanetary space. In this paper, we shall give the main scientific objectives of the magnetic field experiment and brief technical details of the FGM onboard Aditya-1 spacecraft.

Scalar Measurements and Analysis of Helium Jets in Earth Gravity and Microgravity using Rainbow Schlieren Deflectometry

NASA Technical Reports Server (NTRS)

Yep, Tze Wing

2001-01-01

Recent experiments have shown that low-density gas jets injected into a high-density gas undergo an instability mode leading to highly periodic oscillations in the flow field. The transition from laminar to turbulent flow in these jets is abrupt, without a gradual change in scales. Although this type of instability at high Richardson numbers has been attributed to buoyancy, direct physical evidence was not acquired through experiments. In this study, several experiments were conducted in Earth gravity and microgravity to acquire qualitative data on near field flow structure of helium jets injected into air. Microgravity conditions were simulated in the 2.2-second drop tower at NASA Glenn Research Center. The operating parameters of this study included the tube inside diameter, the jet Reynolds number, and the jet Richardson number. Tubes with inside diameters of 19.05 mm and 31.75 mm were used in the experiments conducted in the drop tower. The jet flow was analyzed using quantitative rainbow schlieren deflectometry, a non-intrusive line of sight measurement technique for the whole field. The flow structure was characterized by distributions of angular deflection and the resulting helium mole fraction obtained from color schlieren images taken at 60 Hz. Three sets of experimental data with respect to three schlieren fields of view were acquired for each tube. Results show that the jet in microgravity was up to 70 percent wider than that in Earth gravity. The global jet flow oscillations observed in Earth gravity were absent in microgravity, providing direct experimental evidence that the flow instability in the low-density jet was buoyancy-induced. This study provides quantitative details of temporal flow evolution as the experiments undergo change in gravity in the drop tower.

AC field exposure study: human exposure to 60-Hz electric fields

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

Silva, J.M.

1985-04-01

The objective of this study was to develop a method of estimating human exposure to the 60 Hz electric fields created by transmission lines. The Activity Systems Model simulates human activities in a variety of situations where exposure to electric fields is possible. The model combines maps of electric fields, activity maps, and experimentally determined activity factors to provide histograms of time spent in electric fields of various strengths in the course of agricultural, recreational, and domestic activities. For corroboration, the study team measured actual human exposure at locations across the United States near transmission lines ranging in voltage frommore » 115 to 1200 kV. The data were collected with a specially designed vest that measures exposure. These data demonstrate the accuracy of the exposure model presented in this report and revealed that most exposure time is spent in fields of magnitudes similar to many household situations. The report provides annual exposure estimates for human activities near transmission lines and in the home and compares them with exposure data from typical laboratory animal experiments. For one exposure index, the cumulative product of time and electric field, exposure during some of the laboratory animal experiments is two to four orders of magnitude greater than cumulative exposure for a human during one year of outdoor work on a farm crossed by a transmission line.« less

Near-infrared spectroscopy (NIRS) as a new tool for neuroeconomic research

PubMed Central

Kopton, Isabella M.; Kenning, Peter

2014-01-01

Over the last decade, the application of neuroscience to economic research has gained in importance and the number of neuroeconomic studies has grown extensively. The most common method for these investigations is fMRI. However, fMRI has limitations (particularly concerning situational factors) that should be countered with other methods. This review elaborates on the use of functional Near-Infrared Spectroscopy (fNIRS) as a new and promising tool for investigating economic decision making both in field experiments and outside the laboratory. We describe results of studies investigating the reliability of prototype NIRS studies, as well as detailing experiments using conventional and stationary fNIRS devices to analyze this potential. This review article shows that further research using mobile fNIRS for studies on economic decision making outside the laboratory could be a fruitful avenue helping to develop the potential of a new method for field experiments outside the laboratory. PMID:25147517

Combustion and structure formation in SHS processes under microgravity conditions: SHS plans for microgravity experiments

NASA Technical Reports Server (NTRS)

Merzhanov, A. G.

1995-01-01

This paper outlines ISMAN suggestions for the joint NASA-RSA project 'Combustion and Structure formation in SHS Processes under Microgravity Conditions'. The basic ideas of this work naturally follow from our almost 30-year experience in the field of SHS. As a matter of fact, we have already obtained some results in the following two directions closely related to the microgravity problem. One is the studies on SHS processes in the field of centrifugal forces. These studies aimed at the intensification of gravity-sensitive SHS processes in multicomponent highly caloric systems forming melts at high overloads (up to 2000 g). In other words, these studies had the objectives that are inverse to those in the microgravity studies. The second group of results directly relates to the microgravity problem and the project under consideration. These experiments played the important role in establishing links between SHS and microgravity.

Facilitating Discussion of Theory and Practice in Education Seminars

ERIC Educational Resources Information Center

Herrmann, Bailey; Gallo, Jessica R.

2018-01-01

Field experience seminars, discussion-based courses paired with school-based practicum experiences, provide a space for teacher candidates to discuss the theories they study in their university classes and the practices they observe and implement in their school placements. This article describes an action research study that examines teaching…

Experiences of selected countries in the use of public-private partnership in hospital services provision.

PubMed

Sadeghi, Ahmad; Barati, Omid; Bastani, Peivand; Jafari, Davood Danesh; Etemadian, Masoud

2016-11-01

To review the experiences of selected countries in the use of public-private partnership in the provision of hospital services. This comparative study was conducted in 2015 in Iran. To collect data, valid databases as well as articles, theses, reports and related books in the field of private-sector partnership in hospital services were employed. Using purposive sampling, countries such as the United Kingdom, Spain, Canada, Turkey, Australia and Lesotho, which had successful experiences in the field of application of the public-private partnership in hospital services, were included. Likewise, the only experience in Iran in this field was also reviewed. Studies done between 1980 and 2015 were examined. The results obtained from each country were compared. Implementing public-private partnership had great and valuable outcomes and achievements for governmental hospitals. Moreover, clinical and nonclinical service delivery, hospital utilisation and management along with building, repairing and supportive operations through public-private partnership contracts can be differently divided among the partners. Furthermore, duration of the projects ranged from 12 to 40 years in different countries, depending on the type of the model used. A successful experience in the use of the public-private partnership in the provision of hospital services was observed.

Pathways and pipelines: Self-reported critical experiences for expert and novice geologists

NASA Astrophysics Data System (ADS)

LaDue, N.; Pacheco, H. A.

2011-12-01

The recruitment and retention of geology students has received attention due to pressure from industry to replenish an aging workforce nearing retirement (Gonzales and Keane, 2010). Thorough, qualitative studies have been conducted using critical incident methodology to understand what experiences cause various groups of people to choose careers in the geosciences or geoscience degree programs (Levine et al., 2007; Houlton, 2010). This study both builds upon earlier studies and provides new insights about capacity building in the geosciences. Individuals who have been successfully pipelined into the geosciences ranging from upper-level undergraduates to decades-long professionals, were selected for an expert-novice study about field mapping. All of the 38 participants have field-mapping experience and were selected to achieve a balance of age, gender and experience in the sample and secondarily based on geographic diversity. Participants were asked how they became interested in geology as the last question of an interview about the other tasks during the study. Participants were surficially probed, in contrast to in-depth interviews conducted using critical incident methods. Remarkably, though the interview question was unstructured and open ended, the three persistent themes that emerged are consistent with previous studies of women geologists (Holmes and O'Connell, 2003), under-represented minorities (Levine et al., 2007), and undergraduate geoscience majors (Houlton, 2010): Role or influence of academic experience, influence of and/or connections with people and connections with Earth. Additionally, individual participant comments are well aligned the proposed framework by Kraft et al. (2011) for engaging geoscience students through the affective domain. We suggest that future studies should examine whether these findings are consistent across geologists from sub-domains that are less field-based and involve primarily modeling, or other computer- and lab-based activities.

High resolution NMR study of T{sub 1} magnetic relaxation dispersion. IV. Proton relaxation in amino acids and Met-enkephalin pentapeptide

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

Pravdivtsev, Andrey N.; Yurkovskaya, Alexandra V.; Ivanov, Konstantin L., E-mail: ivanov@tomo.nsc.ru

2014-10-21

Nuclear Magnetic Relaxation Dispersion (NMRD) of protons was studied in the pentapeptide Met-enkephalin and the amino acids, which constitute it. Experiments were run by using high-resolution Nuclear Magnetic Resonance (NMR) in combination with fast field-cycling, thus enabling measuring NMRD curves for all individual protons. As in earlier works, Papers I–III, pronounced effects of intramolecular scalar spin-spin interactions, J-couplings, on spin relaxation were found. Notably, at low fields J-couplings tend to equalize the apparent relaxation rates within networks of coupled protons. In Met-enkephalin, in contrast to the free amino acids, there is a sharp increase in the proton T{sub 1}-relaxation timesmore » at high fields due to the changes in the regime of molecular motion. The experimental data are in good agreement with theory. From modelling the relaxation experiments we were able to determine motional correlation times of different residues in Met-enkephalin with atomic resolution. This allows us to draw conclusions about preferential conformation of the pentapeptide in solution, which is also in agreement with data from two-dimensional NMR experiments (rotating frame Overhauser effect spectroscopy). Altogether, our study demonstrates that high-resolution NMR studies of magnetic field-dependent relaxation allow one to probe molecular mobility in biomolecules with atomic resolution.« less

Bubble Detachment in Variable Gravity Under the Influence of a Non-Uniform Electric Field

NASA Technical Reports Server (NTRS)

Chang, Shinan; Herman, Cila; Iacona, Estelle

2002-01-01

The objective of the study reported in this paper is to investigate the effects of variable, reduced gravity on the formation and detachment behavior of individual air bubbles under the influence of a non-uniform electric field. For this purpose, variable gravity experiments were carried out in parabolic nights. The non-uniform electric field was generated by a spherical electrode and a plate electrode. The effect of the magnitude of the non-uniform electric field and gravity level on bubble formation, development and detachment at an orifice was investigated. An image processing code was developed that allows the measurement of bubble volume, dimensions and contact angle at detachment. The results of this research can be used to explore the possibility of enhancing boiling heat transfer in the variable and low gravity environments by substituting the buoyancy force with a force induced by the electric field. The results of experiments and measurements indicate that the level of gravity significantly affects bubble shape, size and frequency. The electric field magnitude also influences bubble detachment, however, its impact is not as profound as that of variable gravity for the range of electric field magnitudes investigated in the present study.

Water quality of flow through cured-in-place pipe (CIPP).

DOT National Transportation Integrated Search

2017-02-01

Though this study did not include replication, the preponderance of the data from field and simulated-field experiments indicates that Curedin- : Place Pipe (CIPP), with some care in enforcing the Caltrans specification and delaying the reintroductio...

TETAM Model Verification Study. Volume I. Representation of Intervisibility, Initial Comparisons

DTIC Science & Technology

1976-02-01

simulation models in terms of firings, engagements, and losses between tank and antitank as compared with the field data collected during the free play battles of Field Experiment 11.8 are found in Volume III. (Author)

Turbulent magnetic fluctuations in laboratory reconnection

NASA Astrophysics Data System (ADS)

Von Stechow, Adrian; Grulke, Olaf; Klinger, Thomas

2016-07-01

The role of fluctuations and turbulence is an important question in astrophysics. While direct observations in space are rare and difficult dedicated laboratory experiments provide a versatile environment for the investigation of magnetic reconnection due to their good diagnostic access and wide range of accessible plasma parameters. As such, they also provide an ideal chance for the validation of space plasma reconnection theories and numerical simulation results. In particular, we studied magnetic fluctuations within reconnecting current sheets for various reconnection parameters such as the reconnection rate, guide field, as well as plasma density and temperature. These fluctuations have been previously interpreted as signatures of current sheet plasma instabilities in space and laboratory systems. Especially in low collisionality plasmas these may provide a source of anomalous resistivity and thereby contribute a significant fraction of the reconnection rate. We present fluctuation measurements from two complementary reconnection experiments and compare them to numerical simulation results. VINETA.II (Greifswald, Germany) is a cylindrical, high guide field reconnection experiment with an open field line geometry. The reconnecting current sheet has a three-dimensional structure that is predominantly set by the magnetic pitch angle which results from the superposition of the guide field and the in-plane reconnecting field. Within this current sheet, high frequency magnetic fluctuations are observed that correlate well with the local current density and show a power law spectrum with a spectral break at the lower hybrid frequency. Their correlation lengths are found to be extremely short, but propagation is nonetheless observed with high phase velocities that match the Whistler dispersion. To date, the experiment has been run with an external driving field at frequencies higher than the ion cyclotron frequency f_{ci}, which implies that the EMHD framework applies. Recent machine upgrades allow the inclusion of ion dynamics by reducing the drive frequency below f_{ci}. Two numerical codes (EMHD and hybrid, respectively) have been developed at the Max Planck Institute for solar physics and are used to investigate instability mechanisms and scaling laws for the observed results. MRX (PPPL. Princeton) is a zero to medium guide field, toroidal reconnection experiment. Despite the differing plasma parameters, the qualitative magnetic fluctuation behavior (amplitude profiles, spectra and propagation properties) is comparable to VINETA.II. Results from a new measurement campaign at several different guide fields provides partial overlap with VINETA.II guide field ratios and thereby extends the accessible parameter space of our studies.

Conductivity of molten sodium chloride in an arbitrarily weak dc electric field.

PubMed

Delhommelle, Jerome; Cummings, Peter T; Petravic, Janka

2005-09-15

We use nonequilibrium molecular-dynamics (NEMD) simulations to characterize the response of a fluid subjected to an electric field. We focus on the response for very weak fields. Fields accessible by conventional NEMD methods are typically of the order of 10(9) V m(-1), i.e., several orders of magnitude larger than those typically used in experiments. Using the transient time-correlation function, we show how NEMD simulations can be extended to study systems subjected to a realistic dc electric field. We then apply this approach to study the response of molten sodium chloride for a wide range of dc electric fields.

Electric field effect in superconductor-ferroelectric structures

NASA Technical Reports Server (NTRS)

Lemanov, V. V.

1995-01-01

Electric field effect (the E-effect) in superconductors has been studied since 1960 when Glover and Sherill published their results on a shift of the critical temperature T(sub c) about 0.1 mK in Sn and In thin films under the action Off the field E=300 kV/cm. Stadler was the first to study the effect or spontaneous polarization of ferroelectric substrate on the electric properties of superconductors. He observed that the reversal of polarization of TGS substrate under action of external electric field in Sn-TGS structures induced the T(sub c) shift in Sn about 1.3 mK. Since in this case the effect is determined not by the electric field but by the spontaneous polarization, we may call this effect the P-effect. High-T(sub c) superconductors opened the new possibilities to study the E- and P-effects due to low charge carrier density, as compared to conventional superconductors, and to anomalously small coherence length. Experiments in this field began in many laboratories but a breakthrough was made where a shift in T(sub c) by 50 mK was observed in YBCO thin films. Much higher effects were observed in subsequent studies. The first experiments on the P-effect in high-T(sub c) superconductors were reported elsewhere. In this report we shall give a short description of study on the P-effect in high-T(sub c) superconductors.

Important considerations for designing and reporting epidemiologic and clinical studies in dental traumatology.

PubMed

Andersson, Lars; Andreasen, Jens O

2011-08-01

The purpose of this article is to suggest important considerations for epidemiologic and clinical studies in the field of dental traumatology. The article is based on the authors' experiences from research in this field and editorial board work for the scientific journal Dental Traumatology. Examples are given of issues where development is important. The importance of planning ahead of the study and consulting with experts in other fields is emphasized. © 2011 John Wiley & Sons A/S.

Delivering accessible fieldwork: preliminary findings from a collaborative international study

NASA Astrophysics Data System (ADS)

Stokes, Alison; Atchison, Christopher; Feig, Anthony; Gilley, Brett

2017-04-01

Students with disabilities are commonly excluded from full participation in geoscience programs, and encounter significant barriers when accessing field-learning experiences. In order to increase talent and diversity in the geoscience workforce, more inclusive learning experiences must be developed that will enable all students to complete the requirements of undergraduate degree programs, including fieldwork. We discuss the outcomes of a completely accessible field course developed through the collaborative effort of geoscience education practitioners from the US, Canada and the UK. This unique field workshop has brought together current geoscience academics and students with disabilities to share perspectives on commonly-encountered barriers to learning in the field, and explore methods and techniques for overcoming them. While the student participants had the opportunity to learn about Earth processes while situated in the natural environment, participating geoscience instructors began to identify how to improve the design of field courses, making them fully inclusive of learners with disabilities. The outcomes from this experience will be used to develop guidelines to facilitate future development and delivery of accessible geoscience fieldwork.

Encounters with fierce dogs and itchy bedbugs: why my first field work failed

PubMed Central

2014-01-01

This essay, which is the fifth in the series “Recollections, Reflections, and Revelations: Personal Experiences in Ethnobiology”, is a personal reminiscence by the researcher on his first field experience in Turkey in the late 1970s, which was a failure from an ethnobiological point of view but a success for a social scientist pursuing Turkic studies. The author later returned to ethnobiology during subsequent fieldwork on the Faroes. PMID:24885471

Distorted neutrino oscillations from time varying cosmic fields

NASA Astrophysics Data System (ADS)

Krnjaic, Gordan; Machado, Pedro A. N.; Necib, Lina

2018-04-01

Cold, ultralight (≪eV ) bosonic fields can induce fast temporal variation in neutrino couplings, thereby distorting neutrino oscillations. In this paper, we exploit this effect to introduce a novel probe of neutrino time variation and dark matter at long-baseline experiments. We study several representative observables and find that current and future experiments, including DUNE and JUNO, are sensitive to a wide range of model parameters over many decades in mass reach and time-variation periodicity.

Enhancement of Pool Boiling Heat Transfer and Control of Bubble Motion in Microgravity Using Electric Fields - BCOEL

NASA Technical Reports Server (NTRS)

Herman, Cila; Iacona, Estelle; Acquaviva, Tom; Coho, Bill; Grant, Nechelle; Nahra, Henry; Sankaran, Subramanian; Taylor, Al; Julian, Ed; Robinson, Dale;

Simulating emissions of 1,3-dichloropropene after soil fumigation under field conditions.

PubMed

Yates, S R; Ashworth, D J

2018-04-15

Soil fumigation is an important agricultural practice used to produce many vegetable and fruit crops. However, fumigating soil can lead to atmospheric emissions which can increase risks to human and environmental health. A complete understanding of the transport, fate, and emissions of fumigants as impacted by soil and environmental processes is needed to mitigate atmospheric emissions. Five large-scale field experiments were conducted to measure emission rates for 1,3-dichloropropene (1,3-D), a soil fumigant commonly used in California. Numerical simulations of these experiments were conducted in predictive mode (i.e., no calibration) to determine if simulation could be used as a substitute for field experimentation to obtain information needed by regulators. The results show that the magnitude of the volatilization rate and the total emissions could be adequately predicted for these experiments, with the exception of a scenario where the field was periodically irrigated after fumigation. In addition, the timing of the daily peak 1,3-D emissions was not accurately predicted for these experiments due to the peak emission rates occurring during the night or early-morning hours. This study revealed that more comprehensive mathematical models (or adjustments to existing models) are needed to fully describe emissions of soil fumigants from field soils under typical agronomic conditions. Published by Elsevier B.V.

Enhancement of Pool Boiling Heat Transfer and Control of Bubble Motion in Microgravity Using Electric Fields (BCOEL)

NASA Technical Reports Server (NTRS)

Herman, Cila; Iacona, Estelle; Acquaviva, Tom; Coho, Bill; Grant, Nechelle; Nahra, Henry; Taylor, Al; Julian, Ed; Robinson, Dale; VanZandt, Dave

2001-01-01

The BCOEL project focuses on improving pool boiling heat transfer and bubble control in microgravity by exposing the fluid to electric fields. The electric fields induce a body force that can replace gravity in the low gravity environment, and enhance bubble removal from the heated surface. A better understanding of microgravity effects on boiling with and without electric fields is critical to the proper design of the phase-change-heat-removal equipment for use in spacebased applications. The microgravity experiments will focus on the visualization of bubble formation and shape during boiling. Heat fluxes on the boiling surface will be measured, and, together with the measured driving temperature differences, used to plot boiling curves for different electric field magnitudes. Bubble formation and boiling processes were found to be extremely sensitive to g-jitter. The duration of the experimental run is critical in order to achieve steady state in microgravity experiments. The International Space Station provides conditions suitable for such experiments. The experimental apparatus to be used in the study is described in the paper. The apparatus will be tested in the KC-135 first, and microgravity experiments will be conducted on board of the International Space Station using the Microgravity Science Glovebox as the experimental platform.

Laboratory reconnection experiments

NASA Astrophysics Data System (ADS)

Grulke, Olaf

Laboratory experiments dedicated for the study of magnetic reconnection have been contributed considerably to a more detailed understanding of the involved processes. Their strength is to disentangle parameter dependencies, to diagnose in detail the plasma and field response, and to form an excellent testbed for the validation of numerical simulations. In the present paper recent results obtained from the new cylindrical reconnection experiment VINETA II are presented. The experimental setup allows to independently vary plasma parameters, reconnection drive strength/timescale, and current sheet amplitude. Current research objectives focus on two major scientific issues: Guide field effects on magnetic reconnection and the evolution of electromagnetic fluctuations. The superimposed homogeneous magnetic guide field has a strong influence on the spatiotemporal evolution of the current sheet, predominantly due to magnetic pitch angle effects, which leads to a strong elongation of the sheet along the separatrices and results in axial gradients of the reconnection rates. Within the current sheet, incoherent electromagnetic fluctuations are observed. Their magnetic signature is characterized by a broad spectrum somewhat centered around the lower-hybrid frequency and extremely short spatial correlation lengths being typically smaller than the local ion sound radius. The fluctuation amplitude correlates with the local current density and, thus, for low guide fields, displays also axial gradients. Despite the quantitatively different parameter regime and geometry the basic fluctuation properties are in good agreement with studies conducted at the MRX experiment (PPPL).

Mithras Studies of the Boundary Between Open and Closed Field Lines.

DTIC Science & Technology

1994-01-31

I ¸ . . A- : - Final Report • March 1995 MITHRAS STUDIES OF THE BOUNDARY BETWEEN OPEN AND CLOSED FIELD LINES John D. Kelly, Program Manager Richard A...Kelly, Program Manager Richard A. Doe, Research Physicist Geoscience and Engineering Center SRI Project 3245 Prepared for: Department of the Air...characteristic energy, energy flux, and an estimate for upward field-aligned current. On the basis of coordinated radar/optical experiments, Vallance Jones et al

Clogging of an Alpine streambed by silt-sized particles - Insights from laboratory and field experiments.

PubMed

Fetzer, Jasmin; Holzner, Markus; Plötze, Michael; Furrer, Gerhard

2017-12-01

Clogging of streambeds by suspended particles (SP) can cause environmental problems, as it can negatively influence, e.g., habitats for macrozoobenthos, fish reproduction and groundwater recharge. This especially applies in the case of silt-sized SP. Until now, most research has dealt with coarse SP and was carried out in laboratory systems. The aims of this study are to examine (1) whether physical clogging by silt-sized SP exhibits the same dynamics and patterns as by sand-sized SP, and (2) the comparability of results between laboratory and field experiments. We carried out vertical column experiments with sand-sized bed material and silt-sized SP, which are rich in mica minerals. In laboratory experiments, we investigated the degree of clogging quantified by the reduction of porosity and hydraulic conductivity and the maximum clogging depth as a function of size and shape of bed material, size of SP, pore water flow velocity, and concentration of calcium cations. The SP were collected from an Alpine sedimentation basin, where our field experiments were carried out. To investigate the clogging process in the field, we buried columns filled with sand-sized quartz in the stream bed. We found that the maximal bed-to-grain ratio where clogging still occurs is larger for silt-sized SP than for sand-sized SP. The observed clogging depths and the reduction of flow rate through the column from our laboratory experiments were comparable to those from the field. However, our field results showed that the extent of clogging strongly depends on the naturally-occurring hydrological dynamics. The field location was characterized by a more polydisperse suspension, a strongly fluctuating water regime, and high SP concentrations at times, leading to more heterogeneous and more pronounced clogging when compared to laboratory results. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

The Study on Flow Velocity Measurement of Antarctic Krill Trawl Model Experiment in North Bay of South China Sea

NASA Astrophysics Data System (ADS)

Chen, Shuai; Wang, Lumin; Huang, Hongliang; Zhang, Xun

2017-10-01

From August 25 to 29, 2014, the project team carried out the experiment of Antarctic krill trawl in the Beihai Bay of the South China Sea. In order to understand the flow field of the network model in the course of the experiment, it is necessary to record the speed of the ship and to grasp the flow field of the ocean. Therefore, the ocean velocity is measured during the experiment. The flow rate in this experiment was measured using an acoustic Doppler flow meter (Vectoring Plus, Nortek, Norway). In order to compensate for the flow rate error caused by ship drift, the drift condition of the ship was also measured by the positioning device (Snapdragon MSM8274AB, Qualcomm, USA) used in the flow rate measurement. The results show that the actual velocity of the target sea area is in the range of 0.06-0.49 m / s and the direction is 216.17-351.70. And compared with the previous research, the influencing factors were analysed. This study proves that it is feasible to use point Doppler flow meter for velocity study in trawl model experiment.

Experimental Investigation of Effectiveness of Magnetic Field on Food Freezing Process

NASA Astrophysics Data System (ADS)

Suzuki, Toru; Takeuchi, Yuri; Masuda, Kazunori; Watanabe, Manabu; Shirakashi, Ryo; Fukuda, Yutaka; Tsuruta, Takaharu; Yamamoto, Kazutaka; Koga, Nobumitsu; Hiruma, Naoya; Ichioka, Jun; Takai, Kiyoshi

Recently, several food refrigeration equipments that utilize magnetic field have attracted much attention from food production companies, consumers and mass media. However, the effectiveness of the freezers is not scientifically examined. Therefore, the effectiveness should be clarified by experiments or theoretical considerations. In this study, the effect of weak magnetic field (about 0.0005 T) on freezing process of several kinds of foods was investigated by using a specially designed freezer facilitated with magnetic field generator. The investigation included the comparison of freezing curves, drip amount, physicochemical evaluations on color and texture, observation of microstructure, and sensory evaluation. From the results of the control experiments, it can be concluded that weak magnetic field around 0.0005 T provided no significant difference on temperature history during freezing and on the qualities of frozen foods, within our experimental conditions.

A Study of the Effects of Microteaching Experiences Upon the Classroom Behavior of Social Studies Student Teachers.

ERIC Educational Resources Information Center

Limbacher, Philip C.

The hypotheses of this field study, conducted in connection with the Teaching Techniques Laboratory at the University of Illinois, were that student teachers who had participated in a supervised, laboratory, microteaching experience would: 1) receive more favorable pupil evaluations of an initial and final teaching effort on the Teacher…

Facilitating Middle Level Pre-Service Teachers' Literacy Integration in Early Field Experiences

ERIC Educational Resources Information Center

Leckie, Alisa; Wall, Amanda

2016-01-01

This study explored how pre-service teachers integrated literacy in middle level social studies. This study was conducted in the context of the Common Core State Standards (CCSS) and their focus on disciplinary literacy, the Council for the Accreditation of Educator Preparation (CAEP) Standards and their focus on rich clinical experiences, and…

Gifted Girls and Nonmathematical Aspirations: A Longitudinal Case Study of Two Gifted Korean Girls

ERIC Educational Resources Information Center

Lee, Kyeong Hwa; Sriraman, Bharath

2012-01-01

In this longitudinal study of two gifted Korean girls, experiences with early admittance into a gifted program are charted alongside their family and societal experiences that ultimately influenced their career choices in nonmathematical fields. The 8-year-long qualitative study involved extensive interviews with the two gifted girls and their…

Self-Perceived Gains in Communication and Critical Thinking Skills: Are There Disciplinary Differences? AIR 1998 Annual Forum Paper.

ERIC Educational Resources Information Center

Li, Guihua; Long, Shawna; Simpson, Mary Ellen

This study sought to identify similarities and differences influencing students' self-perceived gains in communication and critical thinking skills. The study examined students' background characteristics and general college experiences, as well as their experiences in their major field of study. Structural equation modeling was used to examine…

Application of reflectometry power flow for magnetic field pitch angle measurements in tokamak plasmas (invited).

PubMed

Gourdain, P-A; Peebles, W A

2008-10-01

Reflectometry has successfully demonstrated measurements of many important parameters in high temperature tokamak fusion plasmas. However, implementing such capabilities in a high-field, large plasma, such as ITER, will be a significant challenge. In ITER, the ratio of plasma size (meters) to the required reflectometry source wavelength (millimeters) is significantly larger than in existing fusion experiments. This suggests that the flow of the launched reflectometer millimeter-wave power can be realistically analyzed using three-dimensional ray tracing techniques. The analytical and numerical studies presented will highlight the fact that the group velocity (or power flow) of the launched microwaves is dependent on the direction of wave propagation relative to the internal magnetic field. It is shown that this dependence strongly modifies power flow near the cutoff layer in a manner that embeds the local magnetic field direction in the "footprint" of the power returned toward the launch antenna. It will be shown that this can potentially be utilized to locally determine the magnetic field pitch angle at the cutoff location. The resultant beam drift and distortion due to magnetic field and relativistic effects also have significant consequences on the design of reflectometry systems for large, high-field fusion experiments. These effects are discussed in the context of the upcoming ITER burning plasma experiment.

Utilisation of the magnetic sensor in a smartphone for facile magnetostatics experiment: magnetic field due to electrical current in straight and loop wires

NASA Astrophysics Data System (ADS)

Septianto, R. D.; Suhendra, D.; Iskandar, F.

2017-01-01

This paper reports on the result of a research into the utilisation of a smartphone for the study of magnetostatics on the basis of experiments. The use of such a device gives great measurement result and thus it can replace magnetic sensor tools that are relatively expensive. For the best experimental result, firstly the position of the magnetic sensor in the smartphone has to be considered by way of value mapping of a magnetic field due to permanent magnet. The magnetostatics experiment investigated in this research was the measurement of magnetic field due to electrical currents in two shapes of wire, straight and looped. The current flow, the distance between the observation point and the wire, and the diameter of the loop were the variable parameters investigated to test the smartphone’s capabilities as a measurement tool. To evaluate the experimental results, the measured data were compared with theoretical values that were calculated by using both an analytical and a numerical approach. According to the experiment results, the measured data had good agreement with the results from the analytical and the numerical approach. This means that the use of the magnetic sensor in a smartphone in physics experiments is viable, especially for magnetic field measurement.

An Analysis of the Relationship between Educational Aspiration, Cross-Cultural Sensitivity, and Field of Study of Chinese Student-Teachers at the University of Macau.

ERIC Educational Resources Information Center

Koo, Ramsey D.

This study examined the relationship among educational aspiration, cross-cultural sensitivity, and field of study of 196 Chinese student teachers enrolled in the Faculty of Education for Fall 1994 and Spring 1995 at the University of Macau (China). The study investigated other patterns of cross-cultural experience and activities, including average…

Virtual navigation performance: the relationship to field of view and prior video gaming experience.

PubMed

Richardson, Anthony E; Collaer, Marcia L

2011-04-01

Two experiments examined whether learning a virtual environment was influenced by field of view and how it related to prior video gaming experience. In the first experiment, participants (42 men, 39 women; M age = 19.5 yr., SD = 1.8) performed worse on a spatial orientation task displayed with a narrow field of view in comparison to medium and wide field-of-view displays. Counter to initial hypotheses, wide field-of-view displays did not improve performance over medium displays, and this was replicated in a second experiment (30 men, 30 women; M age = 20.4 yr., SD = 1.9) presenting a more complex learning environment. Self-reported video gaming experience correlated with several spatial tasks: virtual environment pointing and tests of Judgment of Line Angle and Position, mental rotation, and Useful Field of View (with correlations between .31 and .45). When prior video gaming experience was included as a covariate, sex differences in spatial tasks disappeared.

Guidelines for Setting Up an Extended Field Trip to Florida and the Florida Keys: An Interactive Experiential Training Field Biology Program Consisting of Pretrip Instruction, Search Image Training, Field Exercises, and Observations of Tropical Habitats and Coral Reefs.

ERIC Educational Resources Information Center

Baker, Claude D.; And Others

The importance of experiential aspects of biological study is addressed using multi-dimensional classroom and field classroom approaches to student learning. This document includes a guide to setting up this style of field experience. Several teaching innovations are employed to introduce undergraduate students to the literature, techniques, and…

The Floating Lab Research Project: An Approach to Evaluating Field Programs.

ERIC Educational Resources Information Center

Brody, Michael J.

This report explains an evaluative study of the conceptual and affective development of students associated with the Floating Lab Program, an experiential field project sponsored by the University of New Hampshire and the Maine Sea Grant Program. The field program involved an opportunity for students to have hands-on experiences aboard a 65-foot…

Deformation of Water by a Magnetic Field

NASA Astrophysics Data System (ADS)

Chen, Zijun; Dahlberg, E. Dan

2011-03-01

After the discovery that superconducting magnets could levitate diamagnetic objects,1,2 researchers became interested in measuring the repulsion of diamagnetic fluids in strong magnetic fields,3-5 which was given the name "The Moses Effect."5 Both for the levitation experiments and the quantitative studies on liquids, the large magnetic fields necessary were produced by superconducting magnets.

Design of field experiments: Influence of treatment response relative to standard deviation and blocking factor characteristics on efficient blocking strategy

USDA-ARS?s Scientific Manuscript database

Selection of experimental design can markedly influence efficiency of field research. This study used Monte Carlo simulations to compare the ability of different field experimental designs to distinguish defined treatment differences, and the paper concludes with a section on practical use of the in...

Out of the Classroom--Into the Field. Profiles of Promise 32.

ERIC Educational Resources Information Center

Hawke, Sharryl

A junior high school geography class in La Palma, California, offers extensive field trip experiences to teach students methods of historical-geographical research. Resulting from a course that develops research methods in social studies, a club was formed that provides overnight excursions in various field activities. The club is open to 9th and…

Promoting Field Trip Confidence: Teachers Providing Insights for Pre-Service Education

ERIC Educational Resources Information Center

Ateskan, Armagan; Lane, Jennie F.

2016-01-01

Pre-service teachers need experiences in practical matters as a part of field trip preparations programmes. For 14 years, a private, non-profit university in Turkey has involved pre-service teachers in field trip planning, implementation and evaluation. A programme assessment was conducted through a case study to examine the long-term effects of…

Experiments of multichannel least-square methods for sound field reproduction inside aircraft mock-up: Objective evaluations

NASA Astrophysics Data System (ADS)

Gauthier, P.-A.; Camier, C.; Lebel, F.-A.; Pasco, Y.; Berry, A.; Langlois, J.; Verron, C.; Guastavino, C.

2016-08-01

Sound environment reproduction of various flight conditions in aircraft mock-ups is a valuable tool for the study, prediction, demonstration and jury testing of interior aircraft sound quality and annoyance. To provide a faithful reproduced sound environment, time, frequency and spatial characteristics should be preserved. Physical sound field reproduction methods for spatial sound reproduction are mandatory to immerse the listener's body in the proper sound fields so that localization cues are recreated at the listener's ears. Vehicle mock-ups pose specific problems for sound field reproduction. Confined spaces, needs for invisible sound sources and very specific acoustical environment make the use of open-loop sound field reproduction technologies such as wave field synthesis (based on free-field models of monopole sources) not ideal. In this paper, experiments in an aircraft mock-up with multichannel least-square methods and equalization are reported. The novelty is the actual implementation of sound field reproduction with 3180 transfer paths and trim panel reproduction sources in laboratory conditions with a synthetic target sound field. The paper presents objective evaluations of reproduced sound fields using various metrics as well as sound field extrapolation and sound field characterization.

High Fidelity Simulation Experience in Emergency settings: doctors and nurses satisfaction levels.

PubMed

Calamassi, Diletta; Nannelli, Tiziana; Guazzini, Andrea; Rasero, Laura; Bambi, Stefano

2016-11-22

Lots of studies describe High Fidelity Simulation (HFS) as an experience well-accepted by the learners. This study has explored doctors and nurses satisfaction levels during HFS sessions, searching the associations with the setting of simulation events (simulation center or on the field simulation). Moreover, we studied the correlation between HFS experience satisfaction levels and the socio-demographic features of the participants. Mixed method study, using the Satisfaction of High-Fidelity Simulation Experience (SESAF) questionnaire through an online survey. SESAF was administered to doctors and nurses who previously took part to HFS sessions in a simulation center or in the field. Quantitative data were analyzed through descriptive and inferential statistics methods; qualitative data was performed through the Giorgi method. 143 doctors and 94 nurses filled the questionnaire. The satisfaction level was high: on a 10 points scale, the mean score was 8.17 (SD±1.924). There was no significant difference between doctors and nurses satisfaction levels in almost all the SESAF factors. We didn't find any correlation between gender and HFS experience satisfaction levels. The knowledge of theoretical aspects of the simulated case before the HFS experience is related to a higher general satisfaction (r=0.166 p=0.05), a higher effectiveness of debriefing (r=0,143 p=0,05), and a higher professional impact (r=0.143 p=0.05). The respondents that performed a HFS on the field, were more satisfied than the others, and experienced a higher "professional impact", "clinical reasoning and self efficacy", and "team dynamics" (p< 0,01). Narrative data suggest that HFS facilitators should improve their behaviors during the debriefing. Healthcare managers should extend the HFS to all kind of healthcare workers in real clinical settings. There is the need to improve and implement the communication competences of HFS facilitators.

Contrasting effects of nitrogenous pollution on fitness and swimming performance of Iberian waterfrog, Pelophylax perezi (Seoane, 1885), larvae in mesocosms and field enclosures.

PubMed

Egea-Serrano, A; Tejedo, M

2014-01-01

Amphibians are declining worldwide and pollutants have been implicated as a major contributor to these declines. To understand these declines, many studies have assessed the impact of pollutants on amphibian behaviour. However, information regarding their effect on locomotor abilities, as well as the intra-specific variation of the tolerance to pollutants, is extremely rare. Further, the majority of studies examining the impact of pollutants on amphibians have been conducted in simplified laboratory settings. Given the complexity of natural systems, determining whether amphibian responses in laboratory studies can be generalized to more realistic natural scenarios is critical. Towards this goal, this study assessed the impact of nitrogenous pollution on survival and fitness-related larval traits (growth, mass and swimming performance) for three populations of the frog Pelophylax perezi, exposed to different degrees of eutrophication in two different and complementary experiments: (1) pond mesocosms, with NH4Cl isolated or combined with NaNO2 and NaNO3, and (2) field enclosures placed in natural streams differing in their degree of pollution. For both mesocosm and field enclosure experiments, larval mortality was unaffected by nitrogenous pollution. However, in the mesocosm experiment, exposure to nitrogenous compounds reduced final larvae mass and growth. In contrast, in the enclosure experiment, polluted locations facilitated final mass and growth of surviving tadpoles. Population-level variation in the effect of pollution was observed for final larval mass in the mesocosm but not in the field enclosure experiment. In addition, although nitrogenous compounds in both mesocosm and natural conditions had no direct effect on absolute larval swimming performance, they may impact the viability of larvae by affecting the relationships between growth and the swimming abilities. The differential pattern found in the impacts of nitrogenous compounds on larvae of P. perezi when raised in different experimental venues (mesocosms and field conditions) points to the convenience of considering more realistic natural scenarios in assessing the impact of pollutants on amphibians. Copyright © 2013 Elsevier B.V. All rights reserved.

Testing neoclassical competitive market theory in the field

PubMed Central

List, John A.

2002-01-01

This study presents results from a pilot field experiment that tests predictions of competitive market theory. A major advantage of this particular field experimental design is that my laboratory is the marketplace: subjects are engaged in buying, selling, and trading activities whether I run an exchange experiment or am a passive observer. In this sense, I am gathering data in a natural environment while still maintaining the necessary control to execute a clean comparison between treatments. The main results of the study fall into two categories. First, the competitive model predicts reasonably well in some market treatments: the expected price and quantity levels are approximated in many market rounds. Second, the data suggest that market composition is important: buyer and seller experience levels impact not only the distribution of rents but also the overall level of rents captured. An unexpected result in this regard is that average market efficiency is lowest in markets that match experienced buyers and experienced sellers and highest when experienced buyers engage in bargaining with inexperienced sellers. Together, these results suggest that both market experience and market composition play an important role in the equilibrium discovery process. PMID:12432103

The good field trip: How elementary students from diverse socio-economic backgrounds learn science, art, and technology at a museum

NASA Astrophysics Data System (ADS)

Martell, Sandra Toro

The Good Field Trip is a study that uses an ethnographic approach to answer the question of what learning looks like during a field trip to a museum. The study uses the Contextual Model of Learning (Falk & Dierking, 2000) to investigate elementary students' personal, physical, and sociocultural contexts of learning as well as how time affects students' thoughts and feelings about the experience. The author accompanied a group of eight students on a three and a half day camp-like experience to a museum that promotes environmental stewardship and the integration of art, science, and technology use and learning. The author videotaped the students' conversations and experiences and interviewed students before, during, and after the trip. Analyses of the videotapes were supplemented with student documents, including comic books, journal notes, and reflective essays about the trip. Findings include that not all experiences are marked as science, art, and technology; technology use does not occur; art is presented in a more formalized manner than science, which is composed of observation and the acquisition of knowledge about plants and animals; and conversations and activities resemble traditional modes of learning in school settings.

Water quality of flow through cured-in-place pipe (CIPP) : final report.

DOT National Transportation Integrated Search

2017-02-01

Though this study did not include replication, the preponderance of the data from field and simulated-field experiments indicates that Curedin-Place : Pipe (CIPP), with some care in enforcing the Caltrans specification and delaying the reintroduction...

Fog Bank Detector Field Tests : A Technical Summary

DOT National Transportation Integrated Search

1971-12-01

The report summarizes the results of field experiments performed at Pt. Bonita, California. The system under study, a laser LIDAR and a vertical-scanning infrared radiometer, have been discussed in detail in Report No. DOT-TSC-CG-71-3. Measurements o...

Runaway electron behavior in the Frascati Tokamak Upgrade (FTU)

NASA Astrophysics Data System (ADS)

Popovic, Zana; Martin-Solis, Jose Ramon; Esposito, Basilio; Marocco, Daniele; Causa, Federica; Buratti, Paolo; Boncagni, Luca; Carnevale, Daniele; Gospodarczyk, Mateusz

2016-10-01

Several recent experiments in the FTU tokamak are dedicated to the study of runaway electrons (RE), both in the flattop and disruption phases of the discharge. Experiments have been carried out to evaluate the threshold electric field for RE generation during the flattop of ohmic discharges. The measured threshold electric field during RE electron generation and suppression experiments for a wide range of plasma parameters is found to be 2-5 times larger than predicted by the relativistic collisional theory, ER = nee3ln Λ/4 πɛ02 mec2, and is consistent with an increase of the critical field due to the RE synchrotron radiation. Runaway evolution has been numerically simulated using a test particle model including toroidal electric field acceleration, collisions and synchrotron radiation losses. Estimates of RE energy distribution are consistent with the measurements of two recently installed RE diagnostics: HXR-camera and RE Imaging and Spectroscopy (REIS) system. Supported by MINECO (Spain), Projects ENE2012-31753.

Numerical modeling of laser-driven experiments aiming to demonstrate magnetic field amplification via turbulent dynamo

DOE PAGES

Tzeferacos, Petros; Rigby, A.; Bott, A.; ...

2017-03-22

The universe is permeated by magnetic fields, with strengths ranging from a femtogauss in the voids between the filaments of galaxy clusters to several teragauss in black holes and neutron stars. The standard model behind cosmological magnetic fields is the nonlinear amplification of seed fields via turbulent dynamo to the values observed. We have conceived experiments that aim to demonstrate and study the turbulent dynamo mechanism in the laboratory. Here, we describe the design of these experiments through simulation campaigns using FLASH, a highly capable radiation magnetohydrodynamics code that we have developed, and large-scale three-dimensional simulations on the Mira supercomputermore » at the Argonne National Laboratory. The simulation results indicate that the experimental platform may be capable of reaching a turbulent plasma state and determining the dynamo amplification. As a result, we validate and compare our numerical results with a small subset of experimental data using synthetic diagnostics.« less

Education in the Field Influences Children's Ideas and Interest toward Science

NASA Astrophysics Data System (ADS)

Zoldosova, Kristina; Prokop, Pavol

2006-10-01

This paper explores the idea of informal science education in scientific field laboratory (The Science Field Centre). The experimental group of pupils ( N = 153) was experienced with approximately 5-day lasting field trips and experiments in the Field Centre in Slovakia. After finishing the course, two different research methods were used to discover their interest and ideas toward science. Pupils from the experimental group showed significant differences from those that did not experience education in the Field Centre (control group, N = 365). In comparison to the control group, pupils of the experimental group highly preferred book titles that were related to their program in the Field Centre. There were differences between the drawings of ideal school environment from both pupils groups. In the drawings of the experimental group, we found significantly more items connected with the educational environment of the Field Centre (e.g. laboratory equipment, live animals). We suppose field science education would be one of the most effective ways to increase interest of pupils to study science and to invaluable intrinsic motivation at the expense extrinsic motivation.

Approach to Mars Field Geology

NASA Technical Reports Server (NTRS)

Muehlberger, William; Rice, James W.; Parker, Timothy; Lipps, Jere H.; Hoffman, Paul; Burchfiel, Clark; Brasier, Martin

1998-01-01

The goals of field study on Mars are nothing less than to understand the processes and history of the planet at whatever level of detail is necessary. A manned mission gives us an unprecedented opportunity to use the immense power of the human mind to comprehend Mars in extraordinary detail. To take advantage of this opportunity, it is important to examine how we should approach the field study of Mars. In this effort, we are guided by over 200 years of field exploration experience on Earth as well as six manned missions exploring the Moon.

Recent progress in econophysics: Chaos, leverage, and business cycles as revealed by agent-based modeling and human experiments

NASA Astrophysics Data System (ADS)

Xin, Chen; Huang, Ji-Ping

2017-12-01

Agent-based modeling and controlled human experiments serve as two fundamental research methods in the field of econophysics. Agent-based modeling has been in development for over 20 years, but how to design virtual agents with high levels of human-like "intelligence" remains a challenge. On the other hand, experimental econophysics is an emerging field; however, there is a lack of experience and paradigms related to the field. Here, we review some of the most recent research results obtained through the use of these two methods concerning financial problems such as chaos, leverage, and business cycles. We also review the principles behind assessments of agents' intelligence levels, and some relevant designs for human experiments. The main theme of this review is to show that by combining theory, agent-based modeling, and controlled human experiments, one can garner more reliable and credible results on account of a better verification of theory; accordingly, this way, a wider range of economic and financial problems and phenomena can be studied.

Targets and Witnesses: Middle School Students' Sexual Harassment Experiences

ERIC Educational Resources Information Center

Lichty, Lauren F.; Campbell, Rebecca

2012-01-01

School-based peer-to-peer sexual harassment (SH) emerged as an issue of concern in the early 1990s. As a developing field, this literature has several notable gaps. The current study extends previous research by, (a) exploring the understudied experiences of middle school students, (b) assessing students' experiences witnessing SH, and (c)…

Cross-Disciplinary Thermoregulation and Sweat Analysis Laboratory Experiences for Undergraduate Chemistry and Exercise Science Students

ERIC Educational Resources Information Center

Mulligan, Gregory; Taylor, Nichole; Glen, Mary; Tomlin, Dona; Gaul, Catherine A.

2011-01-01

Cross-disciplinary (CD) learning experiences benefit student understanding of concepts and curriculum by offering opportunities to explore topics from the perspectives of alternate fields of study. This report involves a qualitative evaluation of CD health sciences undergraduate laboratory experiences in which concepts and students from two…

Continued support of long-term research - the old rotation

USDA-ARS?s Scientific Manuscript database

The “Old Rotation” experiment (circa 1896) is the oldest continuous cotton study in the world and the third oldest field crops experiment in the U.S. on the same site. The complete history of this experiment was published in 2008 in the centennial issue of Agronomy Journal (C.C. Mitchell, D.P. Delan...

The Impact of Field Experiences in Yellowstone National Park on Practice in Secondary Classrooms

ERIC Educational Resources Information Center

McGrew, Christopher N.

2012-01-01

The current study focused on how six participants of a 2009 professional development activity at Yellowstone National Park described their experience and classroom instructional impact. The author focused on words and phrases illustrating perspective gathering, reflection and public performance to determine the impact of both the experience at…

Participatory Reality Constitution: A Phenomenological Study of Generative Experiences in Higher Education Classrooms

ERIC Educational Resources Information Center

Saiter, Sean M. Avila

2012-01-01

This phenomenological inquiry into the felt experience of participatory sense-making and collaborative presence in small groups explores where and when a common field of resonance is generated among individuals. The experience is named "participatory reality constitution" (PRC). Nine co-participants who met criteria of having experienced…

The Effect Structured Participation Experiences Have on Pre-Service Teachers' Preparedness to Teach Reading

ERIC Educational Resources Information Center

Brannon, Diana; Fiene, Judy

2013-01-01

Many pre-service teachers express a lack of confidence and preparedness to face the challenges of teaching reading in today's classrooms. The current study looks at whether Structured Participation Experiences (SPE) in reading increase pre-service teachers' preparedness to teach reading compared to more traditional unstructured field experiences.…

Overview of the 1997 Dirac High-Magnetic Series at LOS Alamos

NASA Astrophysics Data System (ADS)

Clark, D. A.; Campbell, L. J.; Forman, K. C.; Fowler, C. M.; Goettee, J. D.; Mielke, C. H.; Rickel, D. G.; Marshall, B. R.

2004-11-01

During the summer of 1997, a series of high magnetic field experiments was conducted at Los Alamos National Laboratory. Four experiments utilizing Russian built MC-1 generators, which can reach fields as high as 10 Megagauss, and four smaller strip generator experiments at fields near 1.5 Megagauss were conducted. Experiments mounted on the devices included magnetoresistance of high temperature superconductors and semiconductors, optical reflectivity (conductivity) of semiconductors, magnetization of a magnetic cluster material and a semiconductor, Faraday rotation in a semiconductor and a magnetic cluster material, and transmission spectroscopy of molecules. Brief descriptions of the experimental setups, magnetic field measurement techniques, field results and various experiments are presented. Magnetic field data and other information on Dirac `97 can be found at .

Across the Arctic Teachers Experience Field Research

NASA Astrophysics Data System (ADS)

Warnick, W. K.; Warburton, J.; Wiggins, H. V.; Marshall, S. A.; Darby, D. A.

2005-12-01

From studying snow geese on the North Slope of Alaska to sediment coring aboard the U.S. Coast Guard Cutter Healy in the Arctic Ocean, K-12 teachers embark on scientific expeditions as part of a program that strives to make science in the Arctic a "virtual" reality. In the past two years, seventeen K-12 teachers have participated in Teachers and Researchers Exploring and Collaborating (TREC), a program that pairs teachers with researchers to improve science education through arctic field experiences. TREC builds on the scientific and cultural opportunities of the Arctic, linking research and education through topics that naturally engage students and the wider public. TREC includes expeditions as diverse as studying plants at Toolik Field Station, a research facility located 150 miles above the Arctic Circle; climate change studies in Norway's Svalbard archipelago; studying rivers in Siberia; or a trans-arctic expedition aboard the USCGC Healy collecting an integrated geophysical data set. Funded by the National Science Foundation Office of Polar Programs, TREC offers educators experiences in scientific inquiry while encouraging the public and students to become active participants in the scientific inquiry by engaging them virtually in arctic research. TREC uses online outreach elements to convey the research experience to a broad audience. While in remote field locations, teachers and researchers interact with students and the public through online seminars and live calls from the field, online journals with accompanying photos, and online bulletin boards. Since the program's inception in 2004, numerous visitors have posted questions or interacted with teachers, researchers, and students through the TREC website (http://www.arcus.org/trec). TREC teachers are required to transfer their experience of research and current science into their classroom through the development of relevant activities and resources. Teachers and researchers are encouraged to participate in the Connecting Arctic/Antarctic Researcher and Educators (CARE) Network. CARE, established to help foster ongoing discussions about science content and educational approaches, uses a combination of conference calls and online interactive software for document sharing and discussion. Teacher and researchers pairs are also encouraged to continue developing their collaborative partnership on an individual basis. This presentation will provide an overview of TREC with co-presentations by a TREC teacher and researcher. The presentation highlights the effectiveness and value of pairing virtual learning with real-time research experiences.

Modeling of coherent ultrafast magneto-optical experiments: Light-induced molecular mean-field model

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

Hinschberger, Y.; Hervieux, P.-A.

2015-12-28

We present calculations which aim to describe coherent ultrafast magneto-optical effects observed in time-resolved pump-probe experiments. Our approach is based on a nonlinear semi-classical Drude-Voigt model and is used to interpret experiments performed on nickel ferromagnetic thin film. Within this framework, a phenomenological light-induced coherent molecular mean-field depending on the polarizations of the pump and probe pulses is proposed whose microscopic origin is related to a spin-orbit coupling involving the electron spins of the material sample and the electric field of the laser pulses. Theoretical predictions are compared to available experimental data. The model successfully reproduces the observed experimental trendsmore » and gives meaningful insight into the understanding of magneto-optical rotation behavior in the ultrafast regime. Theoretical predictions for further experimental studies are also proposed.« less

The effect of the geomagnetic field on negative voltage spheres in the ionospheric plasma: Fluid simulation

NASA Astrophysics Data System (ADS)

Ma, T.-Z.; Schunk, R. W.

1994-07-01

Experiments involving the interaction of spherical conducting objects biases with hight voltages in the Low-Earth-Orbit (LEO) environment have been conducted and designed. In these experiments, both positive and negative voltages have been applied to the spheres. Previously, there have been theoretical and numerical studies of positive voltage spheres in plasmas with and without magnetic fields. There also have been studies of negative voltage objects in unmagnetized plasmas. Here, we used a fluid model to study the plasma response to a negative voltage sphere immersed in a magnetized plasma. Our main purpose was to investigate the role of the magnetic field during the early-time interaction between the negative voltage sphere and the ambient plasma in the LEO environment. In this study, different applied voltages, magnetic field strengths, and rise-times of the applied voltages were considered. It was found that with the strength of the geomagnetic field the ions are basically not affected by the magnetic field on the time scale of hundreds of plasma periods considered in this study. The ion density distribution around the sphere and the collected ion flux by the sphere are basically the same as in the case without the magnetic field. The electron motion is strongly affected by the magnetic field. One effect is to change the nature of the electron over-shoot oscillation from regular to somewhat turbulent. Although the electrons move along the magnetic field much more easily than across the magnetic field, some redirection effect causes the electron density to distribute as if the magnetic field effect is minimal. The sheath struture and the electric field around the sphere tend to be spherical. A finite rise-time of the applied voltage reduces the oscillatory activities and delays the ion acceleration. However, the effect of the rise-time depends on both the duration of the rise-time and the ion plasma period.

Comparison of the effectiveness of real and virtual field trips in biology and ecology classes in lower secondary school based on the example of the Maribor island natural educational trail

NASA Astrophysics Data System (ADS)

Puhek, Miro

The present doctoral thesis presents a case study within the scope of which real and virtual field trips have been compared. The emphasis of the study was on determining the levels of knowledge gain effectiveness in the fields of biology and ecology in the final triad (third) of lower secondary school education. The analysis included students completing various tasks along the Maribor Island natural education trail, which had been digitized and inserted into Geopedia. The study was conducted in autumn of 2011 and included 464 students (enrolled in grades from 6 to 9) from 11 lower secondary schools located in the Maribor area. The results have generally shown minute differences between the levels of knowledge acquisition effectiveness between both field trips. During the real field trip, the majority of the students included in the study achieved better results particularly at tasks where they were able to benefit from first-hand experience. During the virtual field trip, individual students were more successful at tasks where they were allowed to access a computer in order to obtain additional information. Within the scope of the study, we had also surveyed lower secondary and secondary school teachers on the frequency of including field trips in the curriculum, on the obstacles that the teachers faced with regard to including field work in it, and on their views on real and virtual field trips. The survey included a total of 386 teachers, the majority whom were teaching the subjects of biology, geography, and natural science. The results have shown that the surveyed teachers regard field trips as a very important educational method that particularly encourages experience-based learning in nature. The views of the teachers on virtual field trips were generally positive, but only when regarded and applied as a supplemental teaching tool and not as a substitute for real field trips.

Salmon cycles: Influences of a science field study immersion experience with Native American young women

NASA Astrophysics Data System (ADS)

Ault, Phyllis Campbell

Native Americans, and particularly Native women, are not proportionally represented in higher education, or in science, mathematics, technology, and engineering fields. This study examined an out-of-school science education program which combined traditional Native American cultural and ecological knowledge with Western science in conducting authentic field studies. A qualitative, embedded case study approach was used to explore how young Native American women were influenced by an out-of-school program integrating a culturally responsive approach and experiential research projects. Within this context of combined cultures, three significant domains emerged: field study in science, sense of place, and networks of supportive relationships. These domains interacted with the aspirations of the eight Native women in the study. Using interview transcripts, reflective writings, and participant data, the study explored the blending of Indigenous and Western science in "communities of practice" (e.g., fisheries biology, restoration ecology, and forestry). The eight Native women in this study participated as young adolescents and later returned as counselors. Interviews focused on their postsecondary aspirations and choices. Findings validated previous research on the value of infusing Traditional Ecological Knowledge and Western science for Native students. The study found the combination of culturally responsive pedagogy and authentic experiences in "communities-of-practice" held a beneficial influence on postsecondary pathways. The importance of respect and friendships fostered through the program was associated with resilience and perseverance in educational aspirations. Immersion in field study with Native peers as well as Native and non-Native researchers was a catalyst for all the women, in a number of different ways, such as: deeper involvement with the Native community, strengthening cultural and academic identity, inspiration to learn more about their cultural heritage, and interest in pursuing science or science-related careers. Commitments to "giving back" to the community, stewardship, and activism emerged as significant outcomes. The experience created a safe, empowering place to be Native, "crazy, a scientist, and a fish geek"---all at once.

Astrophysical particle acceleration mechanisms in colliding magnetized laser-produced plasmas

DOE PAGES

Fox, W.; Park, J.; Deng, W.; ...

2017-08-11

Significant particle energization is observed to occur in numerous astrophysical environments, and in the standard models, this acceleration occurs alongside energy conversion processes including collisionless shocks or magnetic reconnection. Recent platforms for laboratory experiments using magnetized laser-produced plasmas have opened opportunities to study these particle acceleration processes in the laboratory. Through fully kinetic particle-in-cell simulations, we investigate acceleration mechanisms in experiments with colliding magnetized laser-produced plasmas, with geometry and parameters matched to recent high-Mach number reconnection experiments with externally controlled magnetic fields. 2-D simulations demonstrate significant particle acceleration with three phases of energization: first, a “direct” Fermi acceleration driven bymore » approaching magnetized plumes; second, x-line acceleration during magnetic reconnection of anti-parallel fields; and finally, an additional Fermi energization of particles trapped in contracting and relaxing magnetic islands produced by reconnection. Furthermore, the relative effectiveness of these mechanisms depends on plasma and magnetic field parameters of the experiments.« less

Measuring ignitability for in situ burning of oil spills weathered under Arctic conditions: from laboratory studies to large-scale field experiments.

PubMed

Fritt-Rasmussen, Janne; Brandvik, Per Johan

2011-08-01

This paper compares the ignitability of Troll B crude oil weathered under simulated Arctic conditions (0%, 50% and 90% ice cover). The experiments were performed in different scales at SINTEF's laboratories in Trondheim, field research station on Svalbard and in broken ice (70-90% ice cover) in the Barents Sea. Samples from the weathering experiments were tested for ignitability using the same laboratory burning cell. The measured ignitability from the experiments in these different scales showed a good agreement for samples with similar weathering. The ice conditions clearly affected the weathering process, and 70% ice or more reduces the weathering and allows a longer time window for in situ burning. The results from the Barents Sea revealed that weathering and ignitability can vary within an oil slick. This field use of the burning cell demonstrated that it can be used as an operational tool to monitor the ignitability of oil spills. Copyright © 2011 Elsevier Ltd. All rights reserved.

On The Detection Of Footprints From Strong Electron Acceleration In High-Intensity Laser Fields, Including The Unruh Effect

NASA Astrophysics Data System (ADS)

Thirolf, P. G.; Habs, D.; Homma, K.; Hörlein, R.; Karsch, S.; Krausz, F.; Maia, C.; Osterhoff, J.; Popp, A.; Schmid, K.; Schreiber, J.; Schützhold, R.; Tajima, T.; Veisz, L.; Wulz, J.; Yamazaki, T.

2010-04-01

The ultra-high fields of high-power short-pulse lasers are expected to contribute to understanding fundamental properties of the quantum vacuum and quantum theory in very strong fields. For example, the neutral QED vacuum breaks down at the Schwinger field strength of 1.3 1018V/m, where a virtual e+e- pair gains its rest mass energy over a Compton wavelength and materializes as a real pair. At such an ultra-high field strength, an electron experiences an acceleration of as = 2 1028 g and hence fundamental phenomena such as the long predicted Unruh effect start to play a role. The Unruh effect implies that the accelerated electron experiences the vacuum as a thermal bath with the Unruh temperature. In its accelerated frame the electron scatters photons off the thermal bath, corresponding to the emission of an entangled pair of photons in the laboratory frame. In upcoming experiments with intense accelerating fields, we will encounter a set of opportunities to experimentally study the radiation from electrons under extreme fields. Even before the Unruh radiation detection, we should run into the copious Larmor radiation. The detection of Larmor radiation and its characterization themselves have never been experimentally carried out to the best of our knowledge, and thus this amounts to a first serious study of physics at extreme acceleration. For example, we can study radiation damping effects like the Landau-Lifshitz radiation. Furthermore, the experiment should be able to confirm or disprove whether the Larmor and Landau-Lifshitz radiation components may be enhanced by a collective (N2) radiation, if a tightly clumped cluster of electrons is accelerated. The technique of laser driven dense electron sheet formation by irradiating a thin DLC foil target should provide such a coherent electron cluster with a very high density. If and when such mildly relativistic electron sheets are realized, a counterpropagating second laser can interact with them coherently. Under these conditions enhanced Larmor and Unruh radiation signals may be observed. Detection of the Unruh photons (together with its competing radiation components) is envisaged via Compton polarimetry in a novel highly granular 2D-segmented position-sensitive germanium detector.

Saturn's Magnetic Field Model: Birotor Dipole From Cassini RPWS and MAG Experiments

NASA Astrophysics Data System (ADS)

Galopeau, P. H. M.

2016-12-01

The radio and plasma wave science (RPWS) experiment on board the Cassini spacecraft, orbiting around Saturn since July 2004, revealed the presence of two distinct and variable rotation periods in the Saturnian kilometric radiation (SKR) which were attributed to the northern and southern hemispheres respectively. We believe that the periodic time modulations present in the SKR are mainly due to the rotation of Saturn's inner magnetic field. The existence of a double period implies that the inner field is not only limited to a simple rotation dipole but displays more complex structures having the same time periodicities than the radio emission. In order to build a model of this complex magnetic field, it is absolutely necessary to know the accurate phases of rotation linked with the two periods. The radio observations from the RPWS experiment allow a continuous and accurate follow-up of these rotation phases, since the SKR emission is permanently observable and produced very close to the planetary surface. A wavelet transform analysis of the intensity of the SKR signal received at 290 kHz between July 2004 and June 2012 was performed in order to calculate in the same time the different periodicities and phases. A dipole model was proposed for Saturn's inner magnetic field: this dipole presents the particularity to have North and South poles rotating around Saturn's axis at two different angular velocities; this dipole is tilted and not centered. 57 Cassini's revolutions, the periapsis of which is less than 5 Saturnian radii, have been selected for this study. For each of these chosen orbits, it is possible to fit with high precision the measurements of the MAG data experiment given by the magnetometers embarked on board Cassini. A nonrotating external magnetic field completes the model. This study suggests that Saturn's inner magnetic field is neither stationary nor fully axisymmetric. These results can be used as a boundary condition for modelling and constraining the planetary dynamo and they can be a starting point for the study of Saturn's inner structure and the comparison with the interior of Jupiter.

Scientific field training for human planetary exploration

NASA Astrophysics Data System (ADS)

Lim, D. S. S.; Warman, G. L.; Gernhardt, M. L.; McKay, C. P.; Fong, T.; Marinova, M. M.; Davila, A. F.; Andersen, D.; Brady, A. L.; Cardman, Z.; Cowie, B.; Delaney, M. D.; Fairén, A. G.; Forrest, A. L.; Heaton, J.; Laval, B. E.; Arnold, R.; Nuytten, P.; Osinski, G.; Reay, M.; Reid, D.; Schulze-Makuch, D.; Shepard, R.; Slater, G. F.; Williams, D.

2010-05-01

Forthcoming human planetary exploration will require increased scientific return (both in real time and post-mission), longer surface stays, greater geographical coverage, longer and more frequent EVAs, and more operational complexities than during the Apollo missions. As such, there is a need to shift the nature of astronauts' scientific capabilities to something akin to an experienced terrestrial field scientist. To achieve this aim, the authors present a case that astronaut training should include an Apollo-style curriculum based on traditional field school experiences, as well as full immersion in field science programs. Herein we propose four Learning Design Principles (LDPs) focused on optimizing astronaut learning in field science settings. The LDPs are as follows: LDP#1: Provide multiple experiences: varied field science activities will hone astronauts' abilities to adapt to novel scientific opportunities LDP#2: Focus on the learner: fostering intrinsic motivation will orient astronauts towards continuous informal learning and a quest for mastery LDP#3: Provide a relevant experience - the field site: field sites that share features with future planetary missions will increase the likelihood that astronauts will successfully transfer learning LDP#4: Provide a social learning experience - the field science team and their activities: ensuring the field team includes members of varying levels of experience engaged in opportunities for discourse and joint problem solving will facilitate astronauts' abilities to think and perform like a field scientist. The proposed training program focuses on the intellectual and technical aspects of field science, as well as the cognitive manner in which field scientists experience, observe and synthesize their environment. The goal of the latter is to help astronauts develop the thought patterns and mechanics of an effective field scientist, thereby providing a broader base of experience and expertise than could be achieved from field school alone. This will enhance their ability to execute, explore and adapt as in-field situations require.

University Teachers' Experiences of Academic Leadership and Their Approaches to Teaching

ERIC Educational Resources Information Center

Ramsden, Paul; Prosser, Michael; Trigwell, Keith; Martin, Elaine

2007-01-01

The study examined associations between university teachers' experiences of academic leadership, their perceptions of a specific academic context and their approaches to teaching in a particular subject that was taught in that context. The sample consisted of 439 lecturers in Australian universities in four fields of study. Lecturers completed…

Demonstration for Social Change: An Experiment in Local Control.

ERIC Educational Resources Information Center

Gittell, Marilyn; And Others

This evaluative history of New York City's recent experiments in public education documents three projects: Ocean Hill-Brownsville, IS 201, and Two Bridges. This study employs a process oriented and a qualitative methodology which relies most on field observation and participant-observers. The Institute study observed the new community boards,…

EXPERIMENTS WITH PLASMA RINGS

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

Alfven, H.; Lindberg, L.; Mitlid, P.

1960-03-01

The construction of a coaxial plasma gun is described. At its output end the gun is provided with a radial magnetic field, which is trapped by the plasma. The plasma from the gun is studied by photographic and magnetic methods. It is demonstrated that the gun produces magnetized plasma rings with the same basic structure as the rings obtained in toroidal pinch experiments. When the plasma rings are formed, the magnetic field lines from the gun break, a result which is of interest from a theoretical point of view. (auth)

Distorted neutrino oscillations from time varying cosmic fields

DOE PAGES

Krnjaic, Gordan; Machado, Pedro A. N.; Necib, Lina

2018-04-16

Cold, ultralight (more » $$\\ll$$ eV) bosonic fields can induce fast temporal variation in neutrino couplings, thereby distorting neutrino oscillations. In this paper, we exploit this effect to introduce a novel probe of neutrino time variation and dark matter at long-baseline experiments. We study several representative observables and find that current and future experiments, including DUNE and JUNO, are sensitive to a wide range of model parameters over many decades in mass reach and time-variation periodicity.« less

Distorted neutrino oscillations from time varying cosmic fields

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

Krnjaic, Gordan; Machado, Pedro A. N.; Necib, Lina

Cold, ultralight (more » $$\\ll$$ eV) bosonic fields can induce fast temporal variation in neutrino couplings, thereby distorting neutrino oscillations. In this paper, we exploit this effect to introduce a novel probe of neutrino time variation and dark matter at long-baseline experiments. We study several representative observables and find that current and future experiments, including DUNE and JUNO, are sensitive to a wide range of model parameters over many decades in mass reach and time-variation periodicity.« less

Exploring the Role of Field Experience Context in Preservice Teachers' Development as Mathematics Educators

ERIC Educational Resources Information Center

Cooper, Sandi; Nesmith, Suzanne

2013-01-01

Although the importance of field experience is supported and attended to by teacher education programs across the United States, there have been numerous national reports and research findings stressing the need for major improvements in the preparation of teachers with an emphasis on more authentic experiences. Quality field experiences have the…

Pre-Service English Teachers' Perceptions and Practice of Field Experience and Professional Learning from Expert Teachers' Mentoring

ERIC Educational Resources Information Center

Chien, Chin-Wen

2015-01-01

Though it is well known that pre-service teachers' field experiences are recognized as key to enhancing teaching practice, Taiwanese pre-service teachers who take "Teaching Methods and Materials" in elementary school's seven areas often complain that they lack field experience. They do not have the opportunity to experience teaching…

Development of a Rotating Magnetized Plasma Device

NASA Astrophysics Data System (ADS)

Cooke, David; Patton, James; Reid, Remington; Stiles, Ashley; Morrison, Patrik; Koch, Andrei

2017-10-01

Momentum coupling in plasma is a mechanism that is central to a wide range of interesting and important phenomena, magnetosphere-ionosphere coupling, solar eruptions, the interaction of an electro-dynamic tether system in the Earth's ionosphere, and the Critical Ionization Velocity (CIV) mechanism are a few examples. One result of the Space Shuttle Tethered Satellite experiment, TSS-1R, was that the current-voltage response of the experiment in all orbit conditions fell into a narrow range of curves when parameterized as a plasma probe [Thompson, GRL,1998]. Another striking result was the lack of dependence on the Alfvén velocity or other electro-magnetic parameters. This result has led us to revisit the understanding of the speed with which an electric field propagates along the magnetic field using EM-PIC simulation and experiments in our new magnetized plasma chamber. Our initial experiment is a rotating plasma using a solenoidal magnetic field and a radial electric field, with pulsed differential rotation of the plasma column to study the strength of coupling and propagation speed. Characteristics of our `first light' rotating plasma will be presented. Supported by Air Force Office Scientific Research 16RVCOR264.

Impacts of distinct observations during the 2009 Prince William Sound field experiment: A data assimilation study

NASA Astrophysics Data System (ADS)

Li, Zhijin; Chao, Yi; Farrara, John D.; McWilliams, James C.

2013-07-01

A set of data assimilation experiments, known as Observing System Experiments (OSEs) are performed to assess the relative impacts of different types of observations acquired during the 2009 Prince William Sound Field Experiment. The observations assimilated consist primarily of two types: High Frequency (HF) radar surface velocities and vertical profiles of temperature/salinity (T/S) measured by ships, moorings, an Autonomous Underwater Vehicle and a glider. The impact of all the observations, HF radar surface velocities, and T/S profiles is assessed. Without data assimilation, a frequently occurring cyclonic eddy in the central Sound is overly persistent and intense. The assimilation of the HF radar velocities effectively reduces these biases and improves the representation of the velocities as well as the T/S fields in the Sound. The assimilation of the T/S profiles improves the large scale representation of the temperature/salinity and also the velocity field in the central Sound. The combination of the HF radar surface velocities and sparse T/S profiles results in an observing system capable of representing the circulation in the Sound reliably and thus producing analyses and forecasts with useful skill.

Rat Phantom Depth Dose Studies in Electron, X-ray, Gamma-Ray, and Reactor Radiation Fields

DTIC Science & Technology

1986-12-01

i©™D©/^ ^1[P@^T Rat phantom depth dose studies in electron , Xrayf gamma-ray, and reactor radiation fields M. Dooley D. M. Eagleson G. H. Zeman...energy electrons , bremsstrahlung, and mixed neutron/gamma radiation fields are sometimes used in radiobiological experiments employing rats. This report...have revealed differing sensitivities of experimental animals that have been exposed to cobalt-60 photons, high-energy electrons , high-energy X rays

Sounding rocket research Aries/Firewheel, series 22, issue 15

NASA Technical Reports Server (NTRS)

Mozer, F. S.

1981-01-01

Rocket experiments in ionospheric particle and field research flow in seven programs during the last decade are summarized. Experimental techniques were developed and are discussed including the double-probe field technique. The auroral zone, polar cap, and equatorial spread F were studied.

DETECTING INTERACTIONS BETWEEN ELLIPTIO WACCAMAWENSIS AND LEPTODEA OCHRACEA: THE INFLUENCE OF EXPERIMENTAL SCALE.

EPA Science Inventory

Manipulative field experiments are used in ecology to study biotic interactions in populations and communities. In benthic suspension-feeding organisms, these interactions can occur over multiple spatial scales, but this has rarely received experimental attention. A field experim...

Field investigation of high performance pavements in Virginia.

DOT National Transportation Integrated Search

2005-01-01

This study evaluated 18 pavement sections located in high-traffic highways in Virginia to find a premium pavement design with a life span of 40 years or more using current and past field experience. The selected pavement sections were thought to perf...

Anxiolytic effects of lavender oil inhalation on open-field behaviour in rats.

PubMed

Shaw, D; Annett, J M; Doherty, B; Leslie, J C

2007-09-01

To establish a valid animal model of the effects of olfactory stimuli on anxiety, a series of experiments was conducted using rats in an open-field test. Throughout, effects of lavender oil were compared with the effects of chlordiazepoxide (CDP), as a reference anxiolytic with well-known effects on open-field behaviour. Rats were exposed to lavender oil (0.1-1.0 ml) for 30 min (Experiment 1) or 1h (Experiment 2) prior to open-field test and in the open field or injected with CDP (10 mg/kg i.p.). CDP had predicted effects on behaviour, and the higher doses of lavender oil had some effects on behaviour similar to those of CDP. In Experiment 3, various combinations of pre-exposure times and amounts of lavender oil were used. With sufficient exposure time and quantity of lavender the same effects were obtained as in Experiment 2. Experiment 4 demonstrated that these behavioural effects of lavender could be obtained following pre-exposure, even if no oil was present in the open-field test. In Experiments 2-4, lavender oil increased immobility. Together, these experiments suggest that lavender oil does have anxiolytic effects in the open field, but that a sedative effect can also occur at the highest doses.

Hillslope threshold response to rainfall: (1) a field based forensic approach

Treesearch

Chris B. Graham; Ross A. Woods; Jeffrey J. McDonnell

2010-01-01

Hillslope threshold response to storm rainfall is poorly understood. Basic questions regarding the type, location, and flow dynamics of lateral, subsurface flow remain unanswered, even at our most intensively studied field sites. Here we apply a forensic approach where we combined irrigation and excavation experiments at the well studied Maimai hillslope to determine...

Effectively Integrating an International Field Study into the EMBA Curriculum

ERIC Educational Resources Information Center

Cotner, John; Jones, Raymond; Kashlak, Roger

2003-01-01

An international field study (IFS) is an integral part of the EMBA program because of the various critical roles it plays. This international travel experience is a value-added activity not only as "stand alone" vehicle for understanding macro-level environments and firm-level strategic initiatives, but also as a tool that integrates other pieces…

Reforming Only Half: A Study of Practice-Based Teacher Education in Traditional Field Placements

ERIC Educational Resources Information Center

Francis, Anthony Tuf

2017-01-01

Practice-based teacher education is poised to improve teacher education by focusing on interns' enactment of complex teaching practices and helping them develop these professional skills. However, much of this work has yet to study the trajectory of learning between university training and field experiences. This article explores seven history and…

Irrigation water demand: A meta-analysis of price elasticities

NASA Astrophysics Data System (ADS)

Scheierling, Susanne M.; Loomis, John B.; Young, Robert A.

2006-01-01

Metaregression models are estimated to investigate sources of variation in empirical estimates of the price elasticity of irrigation water demand. Elasticity estimates are drawn from 24 studies reported in the United States since 1963, including mathematical programming, field experiments, and econometric studies. The mean price elasticity is 0.48. Long-run elasticities, those that are most useful for policy purposes, are likely larger than the mean estimate. Empirical results suggest that estimates may be more elastic if they are derived from mathematical programming or econometric studies and calculated at a higher irrigation water price. Less elastic estimates are found to be derived from models based on field experiments and in the presence of high-valued crops.

Global meteorological data facility for real-time field experiments support and guidance

NASA Technical Reports Server (NTRS)

Shipham, Mark C.; Shipley, Scott T.; Trepte, Charles R.

1988-01-01

A Global Meteorological Data Facility (GMDF) has been constructed to provide economical real-time meteorological support to atmospheric field experiments. After collection and analysis of meteorological data sets at a central station, tailored meteorological products are transmitted to experiment field sites using conventional ground link or satellite communication techniques. The GMDF supported the Global Tropospheric Experiment Amazon Boundary Layer Experiment (GTE-ABLE II) based in Manaus, Brazil, during July and August 1985; an arctic airborne lidar survey mission for the Polar Stratospheric Clouds (PSC) experiment during January 1986; and the Genesis of Atlantic Lows Experiment (GALE) during January, February and March 1986. GMDF structure is similar to the UNIDATA concept, including meteorological data from the Zephyr Weather Transmission Service, a mode AAA GOES downlink, and dedicated processors for image manipulation, transmission and display. The GMDF improved field experiment operations in general, with the greatest benefits arising from the ability to communicate with field personnel in real time.

A Case Study on the Experiences of University-Based Muslim Women in Physical Activity during Their Studies at One UK Higher Education Institution

ERIC Educational Resources Information Center

Miles, Claire; Benn, Tansin

2016-01-01

The case study explores the experiences of Muslim women in the area of physical activity participation conducted whilst they were studying at one UK University. Previous research in the field indicated that Muslim women can be denied opportunities to participate in areas of sport-related physical activity through multiple factors such as…

First-Hand Experience with Engineering Design and Career Interest in Engineering: An Informal STEM Education Case Study

ERIC Educational Resources Information Center

Ayar, Mehmet C.

2015-01-01

The purpose of this study is to present students' experiences, interest in engineering, and personal narratives while participating in a robotics summer camp in a metropolitan city in Turkey. In this study, I used qualitative data collection methods such as interviews, field notes, and observations. I used the four principles of Engle and Conant…

Merging the Forces of Asynchronous Tutoring and Synchronous Conferencing: A Qualitative Study of Arab ESL Academic Writers Using E-Tutoring

ERIC Educational Resources Information Center

Alqadoumi, Omar Mohamed

2012-01-01

Previous studies in the field of e-tutoring dealt either with asynchronous tutoring or synchronous conferencing as modes for providing e-tutoring services to English learners. This qualitative research study reports the experiences of Arab ESL tutees with both asynchronous tutoring and synchronous conferencing. It also reports the experiences of…

Genotoxicity in native fish associated with agricultural runoff events

USGS Publications Warehouse

Whitehead, Andrew; Kuivila, Kathryn; Orlando, James L.; Kotelevtsev, S.; Anderson, Susan L.

2004-01-01

The primary objective of the present study was to test whether agricultural chemical runoff was associated with in-stream genotoxicity in native fish. Using Sacramento sucker (Catostomus occidentalis), we combined field-caging experiments in an agriculturally dominated watershed with controlled laboratory exposures to field-collected water samples, and we coupled genotoxicity biomarker measurements in fish with bacterial mutagenicity analysis of water samples. We selected DNA strand breakage as a genotoxicity biomarker and Ames Salmonella mutagenicity tests as a second, supporting indicator of genotoxicity. Data from experiments conducted during rainfall runoff events following winter application of pesticides in 2000 and 2001 indicated that DNA strand breaks were significantly elevated in fish exposed to San Joaquin River (CA, USA) water (38.8, 28.4, and 53.6% DNA strand breakage in year 2000 field, year 2000 lab, and year 2001 field exposures, respectively) compared with a nearby reference site (15.4, 8.7, and 12.6% DNA strand breakage in year 2000 field, year 2000 lab, and year 2001 field exposures, respectively). Time-course measurements in field experiments supported a linkage between induction of DNA strand breakage and the timing of agricultural runoff. San Joaquin River water also caused significant reversion mutation in two Ames Salmonella tester strains. Salmonella mutagenicity corroborated in-stream effects, further strengthening a causal relationship between runoff events and genotoxicity. Potentially responsible agents are discussed in the context of timing of runoff events in the field, concordance between laboratory and field exposures, pesticide application patterns in the drainage, and analytical chemistry data.

Asian Tracer Experiment and Atmospheric Modeling (TEAM) Project: Draft Field Work Plan for the Asian Long-Range Tracer Experiment

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

Allwine, K Jerry; Flaherty, Julia E.

2007-08-01

This report provides an experimental plan for a proposed Asian long-range tracer study as part of the international Tracer Experiment and Atmospheric Modeling (TEAM) Project. The TEAM partners are China, Japan, South Korea and the United States. Optimal times of year to conduct the study, meteorological measurements needed, proposed tracer release locations, proposed tracer sampling locations and the proposed durations of tracer releases and subsequent sampling are given. Also given are the activities necessary to prepare for the study and the schedule for completing the preparation activities leading to conducting the actual field operations. This report is intended to providemore » the TEAM members with the information necessary for planning and conducting the Asian long-range tracer study. The experimental plan is proposed, at this time, to describe the efforts necessary to conduct the Asian long-range tracer study, and the plan will undoubtedly be revised and refined as the planning goes forward over the next year.« less

The ISEE-1 and ISEE-2 plasma wave investigation

NASA Technical Reports Server (NTRS)

Gurnett, D. A.; Scarf, F. L.; Fredricks, R. W.; Smith, E. J.

1978-01-01

The ISEE-1 and ISEE-2 plasma wave experiments are designed to provide basic information on wave-particle interactions in the earth's magnetosphere and in the solar wind. The ISEE-1 plasma wave instrument uses three electric dipole antennas with lengths of 215, 73.5 and 0.61 m for electric field measurements, and a triaxial search coil antenna for magnetic field measurements. The ISEE-2 instrument uses two electric dipole antennas with lengths of 30 and 0.61 m for electric field measurements and a single-axis search coil antenna for magnetic field measurements. The primary scientific objectives of the experiments are described, including the resolution of space-time relationships of plasma wave phenomena and VLBI studies. The instrumentation is described, with emphasis on the antennas and the electronics.

Numerical Investigation of Plasma Detachment in Magnetic Nozzle Experiments

NASA Technical Reports Server (NTRS)

Sankaran, Kamesh; Polzin, Kurt A.

2008-01-01

At present there exists no generally accepted theoretical model that provides a consistent physical explanation of plasma detachment from an externally-imposed magnetic nozzle. To make progress towards that end, simulation of plasma flow in the magnetic nozzle of an arcjet experiment is performed using a multidimensional numerical simulation tool that includes theoretical models of the various dispersive and dissipative processes present in the plasma. This is an extension of the simulation tool employed in previous work by Sankaran et al. The aim is to compare the computational results with various proposed magnetic nozzle detachment theories to develop an understanding of the physical mechanisms that cause detachment. An applied magnetic field topology is obtained using a magnetostatic field solver (see Fig. I), and this field is superimposed on the time-dependent magnetic field induced in the plasma to provide a self-consistent field description. The applied magnetic field and model geometry match those found in experiments by Kuriki and Okada. This geometry is modeled because there is a substantial amount of experimental data that can be compared to the computational results, allowing for validation of the model. In addition, comparison of the simulation results with the experimentally obtained plasma parameters will provide insight into the mechanisms that lead to plasma detachment, revealing how they scale with different input parameters. Further studies will focus on modeling literature experiments both for the purpose of additional code validation and to extract physical insight regarding the mechanisms driving detachment.

Changes in the contents of four active diterpenoids at different growth stages in Andrographis paniculata (Burm.f.) Nees (Chuanxinlian)

PubMed Central

2013-01-01

Background The therapeutic activities of Andrographis paniculata are attributed to four major active diterpenoids: andrographolide (AP1), 14-deoxy-11,12-didehydroandrographolide (AP3), neoandrographolide (AP4), and 14-deoxyandrographolide (AP6). This study aims to quantify the four active diterpenoids in various plant organs of A. paniculata at different growth stages in greenhouse and field experiments, with a developed HPLC-diode array detector (HPLC-DAD) method for simultaneous determination of these diterpenoids. Methods Plants were grown in greenhouse and in field conditions, harvested at different growth stages, and separated into different organs for determination of the four active diterpenoids by an HPLC-DAD method. Results The most abundant diterpenoid was AP6 between seedling and vegetative stages in the greenhouse experiment (13.38 to 23.71 mg/g in 2006 and 10.67 to 24.54 mg/g in 2007). High levels of AP6 were also detected in leaves at the transfer stage in the greenhouse experiment (36.05 ± 0.69 mg/g) and field experiment (30.59 ± 1.39 mg/g). The levels of AP6 then decreased as plants matured. The highest content of AP4 was in cotyledons (16.65 ± 4.48 mg/g) at the transfer stage. The highest contents of AP1 were detected in leaves at seed-forming stage in greenhouse experiment (24.72 ± 1.89 mg/g) and vegetative stage in field experiment (43.16 ± 0.92 mg/g). Flowers of A. paniculata contained high levels of AP1 (21.42 ± 3.74 mg/g). AP3 and AP4 were at low levels in leaves at all growth stages. Conclusion In A. paniculata, AP6 was at the highest level in leaves at transfer stage in both greenhouse and field experiments. AP1 was at the highest level in leaves at vegetative stage and seed-forming stage in field and greenhouse experiments, respectively. The contents of AP3 and AP4 in leaves were low at all growth stages. PMID:23320627

Critical Race Theory and Social Studies: Centering the Native American Experience

ERIC Educational Resources Information Center

Chandler, Prentice T.

2010-01-01

This article looks at the ways in which the topic of race is treated in social studies classrooms and the conceptual application of the field of critical race theory (CRT) to the teaching of American history. The author discusses the field of the social studies in terms of its stated goals and how these goals are not met because of a lack of…

A History of Army Aviation - 1950-1962

DTIC Science & Technology

1991-01-01

liaison airplanes from seven civilian flying instrutors and three civilian maintenance instructors. Thirteen officers and eight enlisted men...training at locations lacking established facilities and personnel qualified by experience. Field manuals on concept of employment were then under study...preparation of field manuals by various Army service schools. The Infantry School would prepare, coordinate, and submit to CONARC the manuscript for a new field

Plant-herbivore interactions along elevational gradient: Comparison of field and common garden data

NASA Astrophysics Data System (ADS)

Rokaya, Maan Bahadur; Dostálek, Tomáš; Münzbergová, Zuzana

2016-11-01

In response to climate change, various organisms tend to migrate to higher elevations and latitudes. Unequal migration rates of plants and animals are expected to result in changes in the type and intensity of their interactions such as plant-herbivore interactions. In the present study, we studied the extent of herbivore damage in Salvia nubicola along an elevational gradient in Manang, central Nepal. A common garden experiment was also carried out by sowing seeds collected from different populations along the elevational gradient. As expected, the extent of herbivore damage in the field was significantly lower at higher elevations, and it increased with the population size and at sites without shrubs. In the common garden experiment, herbivore damage was higher in plants originating from lower elevations and from more open habitats. While higher herbivore pressure in the field at lower elevations may suggest that plants will be better protected against herbivores at lower elevations, the common garden study demonstrated the opposite. A possible explanation could be that plants from higher elevations have to adapt to extreme conditions, and lower palatability is a side effect of these adaptations. Thus, S. nubicola in the Himalayan region is likely to survive the expected higher herbivore pressure caused by an upward shift of herbivores under future climate change. Future studies should attempt to elucidate generality of such a conclusion by studying multiple species along similar gradients. Our results from comparison of the field and common garden study suggest that future experiments need to include comparisons in common environments to understand the expected response of plants to changes in herbivore pressure.

Working and Learning in a Field Excursion.

PubMed

Hole, Torstein Nielsen

2018-06-01

This study aimed to discern sociocultural processes through which students learn in field excursions. To achieve this aim, short-term ethnographic techniques were employed to examine how undergraduate students work and enact knowledge (or knowing) during a specific field excursion in biology. The students participated in a working practice that employed research methods and came to engage with various biological phenomena over the course of their work. A three-level analysis of the students' experiences focused on three processes that emerged: participatory appropriation, guided participation, and apprenticeship. These processes derive from advances in practice-oriented theories of knowing. Through their work in the field, the students were able to enact science autonomously; they engaged with peers and teachers in specific ways and developed new understandings about research and epistemology founded on their experiences in the field. Further discussion about the use of "practice" and "work" as analytical concepts in science education is also included.

Regularly scheduled, day-time, slow-onset 60 Hz electric and magnetic field exposure does not depress serum melatonin concentration in nonhuman primates

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

Rogers, W.R.; Smith, H.D.; Orr, J.L.

Experiments conducted with laboratory rodents indicate that exposure to 60 Hz electric fields or magnetic fields can suppress nocturnal melatonin concentrations in pineal gland and blood. In three experiments employing three field-exposed and three sham-exposed nonhuman primates, each implanted with an indwelling venous cannula to allow repeated blood sampling, the authors studied the effects of either 6 kV/m and 50 {micro}T (0.5 G) or 30 kV/m and 100 {micro}T (1.0 G) on serum melatonin patterns. The fields were ramped on and off slowly, so that no transients occurred. Extensive quality control for the melatonin assay, computerized control and monitoring ofmore » field intensities, and consistent exposure protocols were used. No changes in nocturnal serum melatonin concentration resulted from 6 weeks of day-time exposure with slow field onset/offset and a highly regular exposure protocol. These results indicate that, under the conditions tested, day-time exposure to 60 Hz electric and magnetic fields in combination does not result in melatonin suppression in primates.« less

The Real Time Mission Monitor: A Platform for Real Time Environmental Data Integration and Display during NASA Field Campaigns

NASA Astrophysics Data System (ADS)

He, M.; Hardin, D. M.; Goodman, M.; Blakeslee, R.

2008-05-01

The Real Time Mission Monitor (RTMM) is an interactive visualization application based on Google Earth, that provides situational awareness and field asset management during NASA field campaigns. The RTMM can integrate data and imagery from numerous sources including GOES-12, GOES-10, and TRMM satellites. Simultaneously, it can display data and imagery from surface observations including Nexrad, NPOL and SMART- R radars. In addition to all these it can display output from models and real-time flight tracks of all aircraft involved in the experiment. In some instances the RTMM can also display measurements from scientific instruments as they are being flown. All data are recorded and archived in an on-line system enabling playback and review of all sorties. This is invaluable in preparing for future deployments and in exercising case studies. The RTMM facilitates pre-flight planning, in-flight monitoring, development of adaptive flight strategies and post- flight data analyses and assessments. Since the RTMM is available via the internet - during the actual experiment - project managers, scientists and mission planners can collaborate no matter where they are located as long as they have a viable internet connection. In addition, the system is open so that the general public can also view the experiment, in-progress, with Google Earth. Predecessors of RTMM were originally deployed in 2002 as part of the Altus Cumulus Electrification Study (ACES) to monitor uninhabited aerial vehicles near thunderstorms. In 2005 an interactive Java-based web prototype supported the airborne Lightning Instrument Package (LIP) during the Tropical Cloud Systems and Processes (TCSP) experiment. In 2006 the technology was adapted to the 3D Google Earth virtual globe and in 2007 its capabilities were extended to support multiple NASA aircraft (ER-2, WB-57, DC-8) during Tropical Composition, Clouds and Climate Coupling (TC4) experiment and 2007 Summer Aerosonde field study. In April 2008 the RTMM will be flown in the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) experiment to study the atmospheric composition in the Arctic.

Exploring Women Community College Natural Scientists' Personal Experience Narratives through a Subjectivist Lens

ERIC Educational Resources Information Center

Woods, Nancy Anne

2010-01-01

The thrust in education today is to encourage young women to enter nontraditional fields of study such as chemistry, physics, and biology. In order to better prepare the next generation of women scientists, then, we should examine the experiences of women participants already working within these areas. We can learn from their experiences. What…

Tips and Tricks in Outdoor Education. Approaches to Providing Children with Educational Experiences in the Out-of-Doors.

ERIC Educational Resources Information Center

Swan, Malcolm D., Ed.

A revision of the Lorado Taft Field Campus' 1968 "Instructional Materials Packet" on providing children with educational experiences outside the classroom, this book contains materials, tips, worksheets, and plans for offering students an opportunity for supplementary outdoor experiences in a variety of subject-matter areas: animal studies,…

Key Issues in an International Clinical Experience for Graduate Students in Education: Implications for Policy and Practice

ERIC Educational Resources Information Center

Gaudino, Ann C.; Moss, David M.; Wilson, Eleanor V.

2012-01-01

This study examines international clinical experiences in England with graduate education students from The University of Connecticut (UConn) and The University of Virginia (UVA) in the United States of America. Limited research available about international clinical experiences in the field of Education focuses primarily to only describe programs…

Global electrodynamics from superpressure balloons

NASA Technical Reports Server (NTRS)

Holzworth, R. H.; Hu, H.

1995-01-01

Electric field and conductivity measurements in the stratosphere between November 1992 and March 1993 have been made using superpressure balloons in the southern hemisphere. Over 400 payload-days of data have been made during a record setting experiment called ELBBO (Extended Life Balloon Borne Observatories). This experiment resulted in 4 flights aloft simultaneously for over 2 months including one flight which lasted over 4 months. Electrodynamical coupling between the atmosphere and ionosphere is studied using the measured electric fields, and a simple empirical model of the stratospheric conductivity. Altitude profiles of conductivity have been obtained from several superpressure balloon flights using the large end-of-flight altitude swings on the last few days of each flight (as the balloon begins to loose superpressure). Coupling between the fields and atmospheric inertial waves has been observed. Effects and dynamics of the global circuit suggest that standard models are missing significant phenomena. Large scale ionospheric convection activity has been studied from the polar cap to the middle latitudes. Cusp latitude fields have been continuously measured for many days in a row.

Creating stories for learning about the neonatal care experience through the eyes of student nurses: An interpretive, narrative study.

PubMed

Petty, Julia

2017-01-01

Storytelling is an increasingly well recognised and valued platform to learn about the human experience within healthcare. Little is known however about how stories can enhance understanding in neonatal care, a specialised field offering rich opportunities for learning. This study focuses on the creation of stories based on the experiences of student nurses to inform teaching and learning strategies in the neonatal field. The study aimed to create stories from the narratives of student nurses working within the neonatal field and identify what key themes for learning emerged in order to develop a storytelling resource to share experiences with their peers. An interpretive, constructivist approach was used to collect, analyse and create stories from student nurse's experiences, in line with narrative inquiry. Six pre-registration children's nursing students were selected by purposive sampling. Interviews were undertaken within six weeks following placement completion in an agreed location. Narratives were obtained by semi-structured interviews. Narrative analysis and core story creation was undertaken to construct stories and key learning themes emerged which provided the pedagogical basis for subsequent digital resource development. Key themes emerged relating to the insight and observances of student nurses and the neonatal journey they had experienced, including the nature of neonatal care, experiences of the neonate and parents, the environment and their own learning transition. Preliminary peer evaluation of the storytelling resource revealed storytelling as an interesting and novel approach to teaching & learning, learning from ones' peers, preparation for practice and a valuable insight into a new specialist area. The study has value to teaching and learning by enabling an appreciation of how narrative can be used to portray the experiences of learners. Findings also support an approach to analysing narrative to create stories for learning and inform subsequent digital resource development. Copyright © 2016 Elsevier Ltd. All rights reserved.

Studying Geology of Central Texas through Web-Based Virtual Field Trips

NASA Astrophysics Data System (ADS)

Chan, C.; Khan, S. D.; Wellner, J. S.

2007-12-01

Each year over 2500 students, mainly non-science majors, take introductory geology classes at the University of Houston. Optional field trips to Central Texas for these classes provide a unique learning opportunity for students to experience geologic concepts in a real world context. The field trips visit Enchanted Rock, Inks Lake, Bee Cave Road, Lion Mountain, and Slaughter Gap. Unfortunately, only around 10% of our students participate in these field trips. We are developing a web-based virtual field trip for Central Texas to provide an additional effective learning experience for students in these classes. The module for Enchanted Rock is complete and consists of linked geological maps, satellite imagery, digital elevation models, 3-D photography, digital video, and 3-D virtual reality visualizations. The ten virtual stops focus on different geologic process and are accompanied by questions and answers. To test the efficacy of the virtual field trip, we developed a quiz to measure student learning and a survey to evaluate the website. The quiz consists of 10 questions paralleling each stop and information on student attendance on the Central Texas field trip and/or the virtual field trip. From the survey, the average time spent on the website was 26 minutes, and overall the ratings of the virtual field trip were positive. Most noticeably students responded that the information on the website was relevant to their class and that the pictures, figures, and animations were essential to the website. Although high correlation coefficients between responses were expected for some questions (i.e., 0.89 for "The content or text of the website was clear" and "The information on the website was easy to read"), some correlations were less expected: 0.77 for "The number of test questions was appropriate" and "The information on the website was easy to read," and 0.70 for "The test questions reinforced the material presented on the website" and "The information on the website is relevant to my class." These virtual field trips provide an alternative for students who cannot attend the actual field trips. They also allow transfer students to experience these sites before attending upper level field trips, which often return to study these sites in more detail. These modules provide a valuable supplementary experience for all students, as they emphasize skills for which we are presently unable to provide sufficient practice in lecture, fieldtrips, or laboratory. Public access to the field trips is available at: http://geoinfo.geosc.uh.edu/VR/

International Collaboration Activities on Engineered Barrier Systems

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

Jove-Colon, Carlos F.

The Used Fuel Disposition Campaign (UFDC) within the DOE Fuel Cycle Technologies (FCT) program has been engaging in international collaborations between repository R&D programs for high-level waste (HLW) disposal to leverage on gathered knowledge and laboratory/field data of near- and far-field processes from experiments at underground research laboratories (URL). Heater test experiments at URLs provide a unique opportunity to mimetically study the thermal effects of heat-generating nuclear waste in subsurface repository environments. Various configurations of these experiments have been carried out at various URLs according to the disposal design concepts of the hosting country repository program. The FEBEX (Full-scale Engineeredmore » Barrier Experiment in Crystalline Host Rock) project is a large-scale heater test experiment originated by the Spanish radioactive waste management agency (Empresa Nacional de Residuos Radiactivos S.A. – ENRESA) at the Grimsel Test Site (GTS) URL in Switzerland. The project was subsequently managed by CIEMAT. FEBEX-DP is a concerted effort of various international partners working on the evaluation of sensor data and characterization of samples obtained during the course of this field test and subsequent dismantling. The main purpose of these field-scale experiments is to evaluate feasibility for creation of an engineered barrier system (EBS) with a horizontal configuration according to the Spanish concept of deep geological disposal of high-level radioactive waste in crystalline rock. Another key aspect of this project is to improve the knowledge of coupled processes such as thermal-hydro-mechanical (THM) and thermal-hydro-chemical (THC) operating in the near-field environment. The focus of these is on model development and validation of predictions through model implementation in computational tools to simulate coupled THM and THC processes.« less

Power dissipation in HTS coated conductor coils under the simultaneous action of AC and DC currents and fields

NASA Astrophysics Data System (ADS)

Shen, Boyang; Li, Chao; Geng, Jianzhao; Zhang, Xiuchang; Gawith, James; Ma, Jun; Liu, Yingzhen; Grilli, Francesco; Coombs, T. A.

2018-07-01

This paper presents a comprehensive alternating current (AC) loss study of a circular high temperature superconductor (HTS) coated conductor coil. The AC losses from a circular double pancake coil were measured using the electrical method. A 2D axisymmetric H -formulation model using the FEM package in COMSOL Multiphysics has been established to match the circular geometry of the coil used in the experiment. Three scenarios have been analysed: Scenario 1 with AC transport current and DC magnetic field (experiment and simulation); Scenario 2 with DC transport current and AC magnetic field (simulation); and Scenario 3 with AC transport current and AC magnetic field (simulation and experimental data support). The angular dependence analysis on the coil under a magnetic field with different orientation angle θ has been carried out for all three scenarios. For Scenario 3, the effect of the relative phase difference Δφ between the AC current and the AC field on the total AC loss of the coil has been investigated. In summary, a current/field/angle/phase dependent AC loss ( I , B , θ, Δφ) study of a circular HTS coil has been carried out. The obtained results provide useful indications for the future design and research of HTS AC systems.

Differences in Biases and Compensatory Strategies Across Discipline, Rank, and Gender among University Academics

PubMed Central

Giorgini, Vincent; Gibson, Carter; Mecca, Jensen T.; Medeiros, Kelsey E.; Mumford, Michael D.; Connelly, Shane; Devenport, Lynn D.

2014-01-01

The study of ethical behavior and ethical decision making is of increasing importance in many fields, and there is a growing literature addressing the issue. However, research examining differences in ethical decision making across fields and levels of experience is limited. In the present study, biases that undermine ethical decision making and compensatory strategies that may aid ethical decision making were identified in a series of interviews with 63 faculty members across six academic fields (e.g. biological sciences, health sciences, social sciences) and three levels of rank (assistant professor, associate professor, and full professor) as well as across gender. The degree to which certain biases and compensatory strategies were used in justifications for responses to ethical situations was compared across fields, level of experience, and gender. Major differences were found across fields for several biases and compensatory strategies, including biases and compensatory strategies related to use of professional field principles and field-specific guidelines. Furthermore, full professors tend to differ greatly from assistant and associate professors on a number of constructs, and there were differences in the consistency with which biases and compensatory strategies were displayed within these various groups. Implications of these findings for ethics training and future research are discussed. PMID:25479960

The ARASE (ERG) magnetic field investigation

NASA Astrophysics Data System (ADS)

Matsuoka, Ayako; Teramoto, Mariko; Nomura, Reiko; Nosé, Masahito; Fujimoto, Akiko; Tanaka, Yoshimasa; Shinohara, Manabu; Nagatsuma, Tsutomu; Shiokawa, Kazuo; Obana, Yuki; Miyoshi, Yoshizumi; Mita, Makoto; Takashima, Takeshi; Shinohara, Iku

2018-03-01

The fluxgate magnetometer for the Arase (ERG) spacecraft mission was built to investigate particle acceleration processes in the inner magnetosphere. Precise measurements of the field intensity and direction are essential in studying the motion of particles, the properties of waves interacting with the particles, and magnetic field variations induced by electric currents. By observing temporal field variations, we will more deeply understand magnetohydrodynamic and electromagnetic ion-cyclotron waves in the ultra-low-frequency range, which can cause production and loss of relativistic electrons and ring-current particles. The hardware and software designs of the Magnetic Field Experiment (MGF) were optimized to meet the requirements for studying these phenomena. The MGF makes measurements at a sampling rate of 256 vectors/s, and the data are averaged onboard to fit the telemetry budget. The magnetometer switches the dynamic range between ± 8000 and ± 60,000 nT, depending on the local magnetic field intensity. The experiment is calibrated by preflight tests and through analysis of in-orbit data. MGF data are edited into files with a common data file format, archived on a data server, and made available to the science community. Magnetic field observation by the MGF will significantly improve our knowledge of the growth and decay of radiation belts and ring currents, as well as the dynamics of geospace storms.

The Plate Boundary Observatory Student Field Assistant Program in Southern California

NASA Astrophysics Data System (ADS)

Seider, E. L.

2007-12-01

Each summer, UNAVCO hires students as part of the Plate Boundary Observatory (PBO) Student Field Assistant Program. PBO, the geodetic component of the NSF-funded EarthScope project, involves the reconnaissance, permitting, installation, documentation, and maintenance of 880 permanent GPS stations in five years. During the summer 2007, nine students from around the US and Puerto Rico were hired to assist PBO engineers during the busy summer field season. From June to September, students worked closely with PBO field engineers to install and maintain permanent GPS stations in all regions of PBO, including Alaska. The PBO Student Field Assistant Program provides students with professional hands-on field experience as well as continuing education in the geosciences. It also gives students a glimpse into the increasing technologies available to the science community, the scope of geophysical research utilizing these technologies, and the field techniques necessary to complete this research. Students in the PBO Field Assistant Program are involved in all aspects of GPS support, including in-warehouse preparation and in-field installations and maintenance. Students are taught practical skills such as drilling, wiring, welding, hardware configuration, documentation, and proper field safety procedures needed to construct permanent GPS stations. These real world experiences provide the students with technical and professional skills that are not always available to them in a classroom, and will benefit them greatly in their future studies and careers. The 2007 summer field season in Southern California consisted of over 35 GPS permanent station installations. To date, the Southern California region of PBO has installed over 190 GPS stations. This poster presentation will highlight the experiences gained by the Southern California student field assistants, while supporting PBO- Southern California GPS installations in the Mohave Desert and the Inyo National Forest.

The value of place-based and in-field education for climate literacy in the Great Lakes: What role for climate and ecological researchers?

NASA Astrophysics Data System (ADS)

Desai, A. R.

2012-12-01

Climate change is fundamentally global in scope and consequently, much education has focused on understanding and addressing global trends, impacts, and solutions. However, for education and outreach at the undergraduate and adult-learner level, the globe, seen as a whole, is a very abstract concept. What exactly does global temperature mean? The nature of this field can make it a frustrating experience when researchers and scholars try to educate their audiences about climate. How can climate scientists and ecologists, with limited time and training in pedagogy, make best use of their local research for regional climate education? Over the past several years, I have sought to use place-based and field-based education methods with undergraduate and graduate students at UW-Madison, tribal college students at the College of Menominee Nation, land managers, and the general public, including journalists, to help provide more concrete understanding of climate impacts in the Great Lakes region. Ecological research site fieldtrips, renewable energy installation visits, local climate measurement investigations, and short field experiments potentially have great value in this regard. I will present some case studies from these experiences and discuss what I have learned from them on effective ways that field experiences can help make the abstract global climate into concrete regional climate literacy.

Detecting uniaxial single domain grains with a modified IRM technique

NASA Astrophysics Data System (ADS)

Mitra, R.; Tauxe, L.; Gee, J. S.

2011-12-01

Mid-ocean ridge basalt (MORB) specimens have often been found to have high ratios of saturation remanence to saturation magnetization (Mrs/Ms). This has been attributed either to dominant cubic anisotropy or to insufficient saturating field leading to overestimation of Mrs/Ms of a dominantly uniaxial single domain (USD) assemblage. To resolve this debate, we develop an independent technique to detect USD assemblages. The experimental protocol involves subjecting the specimen to bidirectional impulse fields at each step. The experiment is similar to the conventional isothermal remanent magnetization (IRM) acquisition experiment but the field is applied twice, in antiparallel directions. We define a new parameter, IRAT, as the ratio of the remanences at each field step and show it to have characteristic behaviour for the two assemblages; IRAT ˜1 at all field steps for USD and <1 with a strong field dependence for multi-axial single domain (MSD) grains. We verified the theoretical predictions experimentally with representative USD and MSD specimens. Experiments with MORBs gave low IRATs for specimens having high Mrs/Ms. This argues for a dominant MSD assemblage in the MORBs, possibly cubic in nature. Although undersaturation of the samples can indeed be a contributing factor to the exceptionally high Mrs/Ms, this study shows that the nature of the assemblage cannot be dominantly USD.

Magnetic field generation, Weibel-mediated collisionless shocks, and magnetic reconnection in colliding laser-produced plasmas

NASA Astrophysics Data System (ADS)

Fox, W.; Bhattacharjee, A.; Fiksel, G.

2016-10-01

Colliding plasmas are ubiquitous in astrophysical environments and allow conversion of kinetic energy into heat and, most importantly, the acceleration of particles to extremely high energies to form the cosmic ray spectrum. In collisionless astrophysical plasmas, kinetic plasma processes govern the interaction and particle acceleration processes, including shock formation, self-generation of magnetic fields by kinetic plasma instabilities, and magnetic field compression and reconnection. How each of these contribute to the observed spectra of cosmic rays is not fully understood, in particular both shock acceleration processes and magnetic reconnection have been proposed. We will review recent results of laboratory astrophysics experiments conducted at high-power, inertial-fusion-class laser facilities, which have uncovered significant results relevant to these processes. Recent experiments have now observed the long-sought Weibel instability between two interpenetrating high temperature plasma plumes, which has been proposed to generate the magnetic field necessary for shock formation in unmagnetized regimes. Secondly, magnetic reconnection has been studied in systems of colliding plasmas using either self-generated magnetic fields or externally applied magnetic fields, and show extremely fast reconnection rates, indicating fast destruction of magnetic energy and further possibilities to accelerate particles. Finally, we highlight kinetic plasma simulations, which have proven to be essential tools in the design and interpretation of these experiments.

Carbon loaded Teflon (CLT): a power density meter for biological experiments using millimeter waves.

PubMed

Allen, Stewart J; Ross, James A

2007-01-01

The standard technique for measurement of millimeter wave fields utilizes an open-ended waveguide attached to a HP power meter. The alignment of the waveguide with the propagation (K) vector is critical to making accurate measurements. Using this technique, it is difficult and time consuming to make a detailed map of average incident power density over areas of biological interest and the spatial resolution of this instrument does not allow accurate measurements in non-uniform fields. For biological experiments, it is important to know the center field average incident power density and the distribution over the exposed area. Two 4 ft x 4 ft x 1/32 inch sheets of carbon loaded Teflon (CLT) (one 15% carbon and one 25% carbon) were procured and a series of tests to determine the usefulness of CLT in defining fields in the millimeter wavelength range was initiated. Since the CLT was to be used both in the laboratory, where the environment was well controlled, and in the field, where the environment could not be controlled, tests were made to determine effects of change in environmental conditions on ability to use CLT as a millimeter wave dosimeter. The empirical results of this study indicate CLT to be an effective dosimeter for biological experiments both in the laboratory and in the field.

Biological studies of swine exposed to 60-Hz electric fields. Volume 7. Neurology. Final report

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

Not Available

1985-12-01

Neurophysiological responses in three generations of miniature swine chronically exposed to a 30-kV/m, 60-Hz electric field have been assessed in a series of screening experiments. Results are presented from experiments on peripheral nerve function in parental (F/sub 0/) female swine at 100 days of gestation, and from experiments on synaptic transmission in first- and second-generation (F/sub 1/ and F/sub 2/) progeny at 6 weeks of age, all following chronic exposure to a 60-Hz electric field. In the several measures of peripheral nerve function examined, only two showed consistent differences between exposed and sham-exposed animals: C-fiber (but not B-fiber) conduction velocitymore » was decreased in nerve preparations from exposed swine, and recovery, as measured by the increase in amplitude of the compound action potential, was consistently, although not statistically, less in B- and C-fibers from exposed animals when compared to values for the sham-exposed controls. Although changes (increases or decreases) in various parameters of synaptic transmission were observed between exposed and sham-exposed groups, the differences were not consistent across experiments or generations. Only one measure of synaptic function showed a consistent difference throughout the studies: the conduction velocities of B and C components of the postsynaptic compound action potential were increased following electric-field exposure (statistically significant only in B-fibers of the F/sub 2/ generations). 7 refs., 60 figs., 17 tabs.« less

BACTERIOPHAGE TRANSPORT IN SANDY SOIL AND FRACTURED TUFF

EPA Science Inventory

Bacteriophage transport was investigated in laboratory column experiments using sandy soil, a controlled field study in a sandy wash, and laboratory experiments using fractured rock. In the soil columns, the phage MS-2 exhibited significant dispersion and was excluded from 35 to ...

Experiences with Bilateral Art: A Retrospective Study

ERIC Educational Resources Information Center

McNamee, Carole M.

2006-01-01

Recent advances in neuroscience describe the effect of experience on neural architecture. Paralleling these advances in neuroscience, recent explorations in the field of art therapy speculate on the relationship between specific therapeutic interventions and neuroplasticity, which underlies the changes in neural architecture. One such…

Analysis of the Radiated Field in an Electromagnetic Reverberation Chamber as an Upset-Inducing Stimulus for Digital Systems

NASA Technical Reports Server (NTRS)

Torres-Pomales, Wilfredo

2012-01-01

Preliminary data analysis for a physical fault injection experiment of a digital system exposed to High Intensity Radiated Fields (HIRF) in an electromagnetic reverberation chamber suggests a direct causal relation between the time profile of the field strength amplitude in the chamber and the severity of observed effects at the outputs of the radiated system. This report presents an analysis of the field strength modulation induced by the movement of the field stirrers in the reverberation chamber. The analysis is framed as a characterization of the discrete features of the field strength waveform responsible for the faults experienced by a radiated digital system. The results presented here will serve as a basis to refine the approach for a detailed analysis of HIRF-induced upsets observed during the radiation experiment. This work offers a novel perspective into the use of an electromagnetic reverberation chamber to generate upset-inducing stimuli for the study of fault effects in digital systems.

Using Magnetic Fields to Control Convection during Protein Crystallization: Analysis and Validation Studies

NASA Technical Reports Server (NTRS)

Ramachandran, N.; Leslie, F. W.

2004-01-01

The effect of convection during the crystallization of proteins is not very well understood. In a gravitational field, convection is caused by crystal sedimentation and by solutal buoyancy induced flow and these can lead to crystal imperfections. While crystallization in microgravity can approach diffusion limited growth conditions (no convection), terrestrially strong magnetic fields can be used to control fluid flow and sedimentation effects. In this work, we develop the analysis for magnetic flow control and test the predictions using analog experiments. Specifically, experiments on solutal convection in a paramagnetic fluid were conducted in a strong magnetic field gradient using a dilute solution of Manganese Chloride. The observed flows indicate that the magnetic field can completely counter the settling effects of gravity locally and are consistent with the theoretical predictions presented. This phenomenon suggests that magnetic fields may be useful in mimicking the microgravity environment of space for some crystal growth ana biological applications where fluid convection is undesirable.

The influence of field experiences on stages of concern and attitudes of preservice teachers toward science and science teaching

NASA Astrophysics Data System (ADS)

Strawitz, Barbara M.; Malone, Mark R.

The purpose of the study was to determine whether the field experience component of an undergraduate science methods course influenced teachers' concerns and attitudes toward science and science teaching. Age, grade-point average, openmindedness, and school assignment were examined as factors which might explain some of the variance in the dependent measures. A one-group pretest-posttest design was used. Students were administered the Teacher Concerns Questionnaire, the Science Teaching Attitude Scales, and the Rokeach Dogmatism Scale approximately eight weeks after the pretest. Results indicated that field experiences did not significantly change student concerns about teaching science but significantly improved student attitudes toward science and science teaching. Students differing in age, grade-point average, and openmindedness did not difer significantly in changes in concerns and changes in attitude toward science and science teaching. Students assigned to different schools differed significantly in changes in attitude toward science.

Experimental studies of transonic flow field near a longitudinally slotted wind tunnel wall. Ph.D. Thesis - George Washington Univ., 1988

NASA Technical Reports Server (NTRS)

Everhart, Joel L.; Bobbitt, Percy J.

1994-01-01

The results of detailed parametric experiments are presented for the near-wall flow field of a longitudinally slotted transonic wind tunnel. Existing data are reevaluated and new data obtained in the Langley 6- by 19-inch Transonic Wind Tunnel are presented and analyzed. In the experiments, researchers systematically investigate many pertinent wall-geometry variables such as the wall openness and the number of slots along with the free stream Mach number and model angle of attack. Flow field surveys on the plane passing through the centerline of the slot were conducted and are presented. The effects of viscosity on the slot flow are considered in the analysis. The present experiments, combined with those of previous investigations, give a more complete physical characterization of the flow near and through the slotted wall of a transonic wind tunnel.

Open-Loop HIRF Experiments Performed on a Fault Tolerant Flight Control Computer

NASA Technical Reports Server (NTRS)

Koppen, Daniel M.

1997-01-01

During the third quarter of 1996, the Closed-Loop Systems Laboratory was established at the NASA Langley Research Center (LaRC) to study the effects of High Intensity Radiated Fields on complex avionic systems and control system components. This new facility provided a link and expanded upon the existing capabilities of the High Intensity Radiated Fields Laboratory at LaRC that were constructed and certified during 1995-96. The scope of the Closed-Loop Systems Laboratory is to place highly integrated avionics instrumentation into a high intensity radiated field environment, interface the avionics to a real-time flight simulation that incorporates aircraft dynamics, engines, sensors, actuators and atmospheric turbulence, and collect, analyze, and model aircraft performance. This paper describes the layout and functionality of the Closed-Loop Systems Laboratory, and the open-loop calibration experiments that led up to the commencement of closed-loop real-time flight experiments.

Identity Development of Preservice Elementary Teachers of Mathematics from Teacher Education Program to Student Teaching

ERIC Educational Resources Information Center

Kang, Hyun Jung

2012-01-01

Drawing on Lave and Wenger (1991) this study explores how preservice elementary teachers develop themselves as teachers of mathematics, in particular, from the time of their teacher education courses to their field experiences. This study also researches the critical experiences that contributed to the construction of their identities and their…

Surfactant-enhanced remediation of a trichloroethene-contaminated aquifer. 1. Transport of triton X-100

USGS Publications Warehouse

Smith, J.A.; Sahoo, D.; Mclellan, H.M.; Imbrigiotta, T.E.

1997-01-01

Transport of a nonionic surfactant (Triton X-100) at aqueous concentrations less than 400 mg/L through a trichloroethene-contaminated sand-and-gravel aquifer at Picatinny Arsenal, NJ, has been studied through a series of laboratory and field experiments. In the laboratory, batch and column experiments were conducted to quantify the rate and amount of Triton X-100 sorption to the aquifer sediments. In the field, a 400 mg/L aqueous Triton X-100 solution was injected into the aquifer at a rate of 26.5 L/min for a 35-d period. The transport of Triton X-100 was monitored by sampling and analysis of groundwater at six locations surrounding the injection well. Equilibrium batch sorption experiments showed that Triton X-100 sorbs strongly and nonlinearly to the field soil with the sharpest inflection point of the isotherm occurring at an equilibrium aqueous Triton X-100 concentration close to critical micelle concentration. Batch, soil column, and field experimental data were analyzed with zero-, one-, and two- dimensional (respectively) transient solute transport models with either equilibrium or rate-limited sorption. These analyses reveal that Triton X- 100 sorption to the aquifer solids is slow relative to advective and dispersive transport and that an equilibrium sorption model cannot simulate accurately the observed soil column and field data. Comparison of kinetic sorption parameters from batch, column, and field transport data indicate that both physical heterogeneities and Triton X-100 mass transfer between water and soil contribute to the kinetic transport effects.Transport of a nonionic surfactant (Triton X-100) at aqueous concentrations less than 400 mg/L through a trichloroethene-contaminated sand-and-gravel aquifer was studied. Equilibrium batch sorption experiments showed that Triton X-100 sorbs strongly and nonlinearly to the field soil with the sharpest inflection point of the isotherm occurring at an equilibrium aqueous Triton X-100 concentration close to critical micelle concentration. Batch, soil column, and field experimental data were analyzed with zero-, one-, and two-dimensional transient solute transport models with either equilibrium or rate-limited sorption. These analyses revealed that Triton X-100 sorption to the aquifer solids was slow relative to advective and dispersive transport.

Cross-Field Differences in Creative Problem-Solving Skills: A Comparison of Health, Biological, and Social Sciences

PubMed Central

Mumford, Michael D.; Antes, Alison L.; Caughron, Jared J.; Connelly, Shane; Beeler, Cheryl

2010-01-01

In the present study, 258 doctoral students working in the health, biological, and social sciences were asked to solve a series of field-relevant problems calling for creative thought. Proposed solutions to these problems were scored with respect to critical creative thinking skills such as problem definition, conceptual combination, and idea generation. Results indicated that health, biological, and social scientists differed with respect to their skill in executing various operations, or processes, involved in creative thought. Interestingly, no differences were observed as a function of the students’ level of experience. The implications of these findings for understanding cross-field, and cross-experience level, differences in creative thought are discussed. PMID:20936085

[The need for experiments using primates from a scientific point of view].

PubMed

Kaup, F J

2007-03-01

Concerning the public discussion on animal experiments using primates, various research fields are demonstrated where non-human primates are necessary for certain scientific reasons at this time. Non-human Primates are used in Germany mainly in regulatory toxicology and pharmaceutical safety studies.A small amount is disposed in different fields of biological or biomedical basic research. This includes in particular neurosciences and infection research. 2006 New and Old World monkeys were needed in Germany in 2005. No chimpanzees are used anymore as laboratory animals in Germany since many years. Several examples are presented to demonstrate that certain research fields need non-human primates as laboratory animals in the foreseeable future.

Description and effects of sequential behavior practice in teacher education.

PubMed

Sharpe, T; Lounsbery, M; Bahls, V

1997-09-01

This study examined the effects of a sequential behavior feedback protocol on the practice-teaching experiences of undergraduate teacher trainees. The performance competencies of teacher trainees were analyzed using an alternative opportunities for appropriate action measure. Data support the added utility of sequential (Sharpe, 1997a, 1997b) behavior analysis information in systematic observation approaches to teacher education. One field-based undergraduate practicum using sequential behavior (i.e., field systems analysis) principles was monitored. Summarized are the key elements of the (a) classroom instruction provided as a precursor to the practice teaching experience, (b) practice teaching experience, and (c) field systems observation tool used for evaluation and feedback, including multiple-baseline data (N = 4) to support this approach to teacher education. Results point to (a) the strong relationship between sequential behavior feedback and the positive change in four preservice teachers' day-to-day teaching practices in challenging situational contexts, and (b) the relationship between changes in teacher practices and positive changes in the behavioral practices of gymnasium pupils. Sequential behavior feedback was also socially validated by the undergraduate participants and Professional Development School teacher supervisors in the study.

Considerations of education in the field of biophotonics in engineering: the experience of the subject fundamentals of biophotonics

NASA Astrophysics Data System (ADS)

Fanjul-Vélez, F.; Arce-Diego, J. L.

2017-12-01

Education in the field of photonics is usually somehow complex due to the fact that most of the programs include just a few subjects on the field, apart from specific Master programs in Photonics. There are also specific doctorate programs dealing with photonics. Apart from the problems shared with photonics in education in general, biophotonics specifically needs an interdisciplinary approach between biomedical and technical or scientific fields. In this work, we present our education experience in teaching the subject Fundamentals of Biophotonics, intended preferentially to engineering Bachelor and Master degrees students, but also to science and medicine students. First it was necessary to join a teaching group coming from the scientific technical and medical fields, working together in the subject. This task was easier as our research group, the Applied Optical Techniques group, had previous contacts and experience in working with medicine professors and medical doctors at hospitals. The orientation of the subject, intended for both technical and medical students, has to be carefully selected. All this information could be employed by other education institutions willing to implement studies on biomedical optics.

Using natural Chinese zeolite to remove ammonium from rainfall runoff following urea fertilization of a paddy rice field.

PubMed

Wang, Xiao-Ling; Qiao, Bin; Li, Song-Min; Li, Jian-Sheng

2016-03-01

The potential of natural Chinese zeolite to remove ammonium from rainfall runoff following urea applications to a paddy rice field is assessed in this study. Laboratory batch kinetic and isotherm experiments were carried out first to investigate the ammonium adsorption capacity of the natural zeolite. Field experiments using zeolite adsorption barriers installed at drain outlets in a paddy rice field were also carried out during natural rainfall events to evaluate the barrier's dynamic removal capacity of ammonium. The results demonstrate that the adsorption kinetics are accurately described by the Elovich model, with a coefficient of determination (R (2)) ranging from 0.9705 to 0.9709, whereas the adsorption isotherm results indicate that the Langmuir-Freundlich model provides the best fit (R (2) = 0.992) for the equilibrium data. The field experiments show that both the flow rate and the barrier volume are important controls on ammonium removal from rainfall runoff. A low flow rate leads to a higher ammonium removal efficiency at the beginning of the tests, while a high flow rate leads to a higher quantity of ammonium adsorbed over the entire runoff process.

Effects of an electric field on white sharks: in situ testing of an electric deterrent.

PubMed

Huveneers, Charlie; Rogers, Paul J; Semmens, Jayson M; Beckmann, Crystal; Kock, Alison A; Page, Brad; Goldsworthy, Simon D

2013-01-01

Elasmobranchs can detect minute electromagnetic fields, <1 nV cm(-1), using their ampullae of Lorenzini. Behavioural responses to electric fields have been investigated in various species, sometimes with the aim to develop shark deterrents to improve human safety. The present study tested the effects of the Shark Shield Freedom7™ electric deterrent on (1) the behaviour of 18 white sharks (Carcharodon carcharias) near a static bait, and (2) the rates of attacks on a towed seal decoy. In the first experiment, 116 trials using a static bait were performed at the Neptune Islands, South Australia. The proportion of baits taken during static bait trials was not affected by the electric field. The electric field, however, increased the time it took them to consume the bait, the number of interactions per approach, and decreased the proportion of interactions within two metres of the field source. The effect of the electric field was not uniform across all sharks. In the second experiment, 189 tows using a seal decoy were conducted near Seal Island, South Africa. No breaches and only two surface interactions were observed during the tows when the electric field was activated, compared with 16 breaches and 27 surface interactions without the electric field. The present study suggests that the behavioural response of white sharks and the level of risk reduction resulting from the electric field is contextually specific, and depends on the motivational state of sharks.

Effects of an Electric Field on White Sharks: In Situ Testing of an Electric Deterrent

PubMed Central

Huveneers, Charlie; Rogers, Paul J.; Semmens, Jayson M.; Beckmann, Crystal; Kock, Alison A.; Page, Brad; Goldsworthy, Simon D.

2013-01-01

Elasmobranchs can detect minute electromagnetic fields, <1 nVcm–1, using their ampullae of Lorenzini. Behavioural responses to electric fields have been investigated in various species, sometimes with the aim to develop shark deterrents to improve human safety. The present study tested the effects of the Shark Shield Freedom7™ electric deterrent on (1) the behaviour of 18 white sharks (Carcharodon carcharias) near a static bait, and (2) the rates of attacks on a towed seal decoy. In the first experiment, 116 trials using a static bait were performed at the Neptune Islands, South Australia. The proportion of baits taken during static bait trials was not affected by the electric field. The electric field, however, increased the time it took them to consume the bait, the number of interactions per approach, and decreased the proportion of interactions within two metres of the field source. The effect of the electric field was not uniform across all sharks. In the second experiment, 189 tows using a seal decoy were conducted near Seal Island, South Africa. No breaches and only two surface interactions were observed during the tows when the electric field was activated, compared with 16 breaches and 27 surface interactions without the electric field. The present study suggests that the behavioural response of white sharks and the level of risk reduction resulting from the electric field is contextually specific, and depends on the motivational state of sharks. PMID:23658766

Large-scale experimental technology with remote sensing in land surface hydrology and meteorology

NASA Technical Reports Server (NTRS)

Brutsaert, Wilfried; Schmugge, Thomas J.; Sellers, Piers J.; Hall, Forrest G.

1988-01-01

Two field experiments to study atmospheric and land surface processes and their interactions are summarized. The Hydrologic-Atmospheric Pilot Experiment, which tested techniques for measuring evaporation, soil moisture storage, and runoff at scales of about 100 km, was conducted over a 100 X 100 km area in France from mid-1985 to early 1987. The first International Satellite Land Surface Climatology Program field experiment was conducted in 1987 to develop and use relationships between current satellite measurements and hydrologic, climatic, and biophysical variables at the earth's surface and to validate these relationships with ground truth. This experiment also validated surface parameterization methods for simulation models that describe surface processes from the scale of vegetation leaves up to scales appropriate to satellite remote sensing.

Adolescent Experience of Menstruation in Rural Kenya.

PubMed

Secor-Turner, Molly; Schmitz, Kaitlin; Benson, Kristen

2016-01-01

Although menstruation is a universal experience, girls in resource-poor areas face unique challenges related to menstruation management. In Kenya, girls miss nearly 3.5 million learning days per month because of limited access to sanitary products and lack of adequate sanitation. Global priorities to address gender inequality-especially related to education-often do not consider the impact of poverty on gendered experiences, such as menstruation. The aim of the study was to describe the experiences of menstruation from the perspective of adolescent girls living in rural Kenya. Data for this qualitative study were collected through 29 individual interviews with adolescent girls and separate field observations. Descriptive content analysis was used to identify themes reflective of the data from the individual interviews and field notes. Four themes were developed to summarize the data: (a) receiving information about menstruation, (b) experiences of menstruation, (c) menstrual hygiene practices, and (d) social norms and the meaning of menstruation. Findings from this study describe the impact of menstruation on the lives of adolescent girls in rural Kenya. Menstrual hygiene management and its associated challenges may impact girls' academic continuity. Experiences of menstruation also reinforce gender inequality and further marginalize girls in low-income, rural areas of Kenya. Consideration of menstruation is critical to promote health and academic continuity for girls in rural Kenya.

Validation of single-fluid and two-fluid magnetohydrodynamic models of the helicity injected torus spheromak experiment with the NIMROD code

NASA Astrophysics Data System (ADS)

Akcay, Cihan; Kim, Charlson C.; Victor, Brian S.; Jarboe, Thomas R.

2013-08-01

We present a comparison study of 3-D pressureless resistive MHD (rMHD) and 3-D presureless two-fluid MHD models of the Helicity Injected Torus with Steady Inductive helicity injection (HIT-SI). HIT-SI is a current drive experiment that uses two geometrically asymmetric helicity injectors to generate and sustain toroidal plasmas. The comparable size of the collisionless ion skin depth di to the resistive skin depth predicates the importance of the Hall term for HIT-SI. The simulations are run with NIMROD, an initial-value, 3-D extended MHD code. The modeled plasma density and temperature are assumed uniform and constant. The helicity injectors are modeled as oscillating normal magnetic and parallel electric field boundary conditions. The simulations use parameters that closely match those of the experiment. The simulation output is compared to the formation time, plasma current, and internal and surface magnetic fields. Results of the study indicate 2fl-MHD shows quantitative agreement with the experiment while rMHD only captures the qualitative features. The validity of each model is assessed based on how accurately it reproduces the global quantities as well as the temporal and spatial dependence of the measured magnetic fields. 2fl-MHD produces the current amplification Itor/Iinj and formation time τf demonstrated by HIT-SI with similar internal magnetic fields. rMHD underestimates Itor/Iinj and exhibits much a longer τf. Biorthogonal decomposition (BD), a powerful mathematical tool for reducing large data sets, is employed to quantify how well the simulations reproduce the measured surface magnetic fields without resorting to a probe-by-probe comparison. BD shows that 2fl-MHD captures the dominant surface magnetic structures and the temporal behavior of these features better than rMHD.

Experimental and theoretical studies of active control of resistive wall mode growth in the EXTRAP T2R reversed-field pinch

NASA Astrophysics Data System (ADS)

Drake, J. R.; Brunsell, P. R.; Yadikin, D.; Cecconello, M.; Malmberg, J. A.; Gregoratto, D.; Paccagnella, R.; Bolzonella, T.; Manduchi, G.; Marrelli, L.; Ortolani, S.; Spizzo, G.; Zanca, P.; Bondeson, A.; Liu, Y. Q.

2005-07-01

Active feedback control of resistive wall modes (RWMs) has been demonstrated in the EXTRAP T2R reversed-field pinch experiment. The control system includes a sensor consisting of an array of magnetic coils (measuring mode harmonics) and an actuator consisting of a saddle coil array (producing control harmonics). Closed-loop (feedback) experiments using a digital controller based on a real time Fourier transform of sensor data have been studied for cases where the feedback gain was constant and real for all harmonics (corresponding to an intelligent-shell) and cases where the feedback gain could be set for selected harmonics, with both real and complex values (targeted harmonics). The growth of the dominant RWMs can be reduced by feedback for both the intelligent-shell and targeted-harmonic control systems. Because the number of toroidal positions of the saddle coils in the array is half the number of the sensors, it is predicted and observed experimentally that the control harmonic spectrum has sidebands. Individual unstable harmonics can be controlled with real gains. However if there are two unstable mode harmonics coupled by the sideband effect, control is much less effective with real gains. According to the theory, complex gains give better results for (slowly) rotating RWMs, and experiments support this prediction. In addition, open loop experiments have been used to observe the effects of resonant field errors applied to unstable, marginally stable and robustly stable modes. The observed effects of field errors are consistent with the thin-wall model, where mode growth is proportional to the resonant field error amplitude and the wall penetration time for that mode harmonic.

From hopping to ballistic transport in graphene-based electronic devices

NASA Astrophysics Data System (ADS)

Taychatanapat, Thiti

This thesis describes electronic transport experiments in graphene from the hopping to the ballistic regime. The first experiment studies dual-gated bilayer graphene devices. By applying an electric field with these dual gates, we can open a band gap in bilayer graphene and observe an increase in resistance of over six orders of magnitude as well as a strongly non-linear behavior in the transport characteristics. A temperature-dependence study of resistance at large electric field at the charge neutrality point shows the change in the transport mechanism from a hopping dominated regime at low temperature to a diffusive regime at high temperature. The second experiment examines electronic properties of Bernal-stacked trilayer graphene. Due to the low mobility of trilayer graphene on SiO 2substrates, we employ hexagonal boron nitride as a local substrate to improve its mobility. This led us to observe a quantum Hall effect with multiple Landau level crossings, proving the coexistence of massless and massive Dirac fermions in Bernal-stacked trilayer graphene. From the position of these crossing points in magnetic field and electron density, we can deduce the band parameters used to model its band structure. At high magnetic field, we observe broken symmetry states via Landau level splittings as well as crossings among these broken-symmetry states. In the third experiment, we investigate transverse magnetic focusing (TMF) in mono-, bi-, and tri-layer graphene. The ability to tune density allows us to electronically modify focal points and investigate TMF continuously from hole to electron regimes. This also allows us to observe the change in band structure of trilayer graphene as a function of applied electric field. Finally, we also observe TMF at room temperature in monolayer graphene which unambiguously proves the existence of ballistic transport at room temperature.

Dynamics of Two Interactive Bubbles in An Acoustic Field - Part II: Experiments

NASA Astrophysics Data System (ADS)

Ashgriz, Nasser; Barbat, Tiberiu; Liu, Ching-Shi

1996-11-01

The motion of two air bubbles levitated in water, in the presence of a high-frequency acoustic field is experimentally studied. The interaction force between them is named "secondary Bjerknes force" and may be significant in microgravity environments; in our experiments the buoyancy effect is compensated through the action of the "primary Bjerknes forces" - interaction between each bubble oscillation and external sound field. The stationary sound field is produced by a piezoceramic tranducer, in the range of 22-24 kHz. The experiments succesfully demonstrate the existence of three patterns of interaction between bubbles of various sizes: attraction, repulsion and oscillation. Bubbles attraction is quantitatively studied using a high speed video, for "large" bubbles (in the range 0.5-2 mm radius); bubbles repulsion and oscillations are only observed with a regular video, for "small" bubbles (around the resonance size at these frequencies, 0.12 mm). Velocities and accelerations of each bubble are computed from the time history of the motion. The theoretical equations of motion are completed with a drag force formula for single bubbles and solved numerically. Experimental results, for the case of two attracting bubbles, are in good agreement with the numerical model, especially for values of the mutual distance greater than 3 large bubble radii.

A cross-polarization based rotating-frame separated-local-field NMR experiment under ultrafast MAS conditions

NASA Astrophysics Data System (ADS)

Zhang, Rongchun; Damron, Joshua; Vosegaard, Thomas; Ramamoorthy, Ayyalusamy

2015-01-01

Rotating-frame separated-local-field solid-state NMR experiments measure highly resolved heteronuclear dipolar couplings which, in turn, provide valuable interatomic distances for structural and dynamic studies of molecules in the solid-state. Though many different rotating-frame SLF sequences have been put forth, recent advances in ultrafast MAS technology have considerably simplified pulse sequence requirements due to the suppression of proton-proton dipolar interactions. In this study we revisit a simple two-dimensional 1H-13C dipolar coupling/chemical shift correlation experiment using 13C detected cross-polarization with a variable contact time (CPVC) and systematically study the conditions for its optimal performance at 60 kHz MAS. In addition, we demonstrate the feasibility of a proton-detected version of the CPVC experiment. The theoretical analysis of the CPVC pulse sequence under different Hartmann-Hahn matching conditions confirms that it performs optimally under the ZQ (w1H - w1C = ±wr) condition for polarization transfer. The limits of the cross polarization process are explored and precisely defined as a function of offset and Hartmann-Hahn mismatch via spin dynamics simulation and experiments on a powder sample of uniformly 13C-labeled L-isoleucine. Our results show that the performance of the CPVC sequence and subsequent determination of 1H-13C dipolar couplings are insensitive to 1H/13C frequency offset frequency when high RF fields are used on both RF channels. Conversely, the CPVC sequence is quite sensitive to the Hartmann-Hahn mismatch, particularly for systems with weak heteronuclear dipolar couplings. We demonstrate the use of the CPVC based SLF experiment as a tool to identify different carbon groups, and hope to motivate the exploration of more sophisticated 1H detected avenues for ultrafast MAS.

Experiments in Computing: A Survey

PubMed Central

Moisseinen, Nella

2014-01-01

Experiments play a central role in science. The role of experiments in computing is, however, unclear. Questions about the relevance of experiments in computing attracted little attention until the 1980s. As the discipline then saw a push towards experimental computer science, a variety of technically, theoretically, and empirically oriented views on experiments emerged. As a consequence of those debates, today's computing fields use experiments and experiment terminology in a variety of ways. This paper analyzes experimentation debates in computing. It presents five ways in which debaters have conceptualized experiments in computing: feasibility experiment, trial experiment, field experiment, comparison experiment, and controlled experiment. This paper has three aims: to clarify experiment terminology in computing; to contribute to disciplinary self-understanding of computing; and, due to computing's centrality in other fields, to promote understanding of experiments in modern science in general. PMID:24688404

Experiments in computing: a survey.

PubMed

Tedre, Matti; Moisseinen, Nella

2014-01-01

Experiments play a central role in science. The role of experiments in computing is, however, unclear. Questions about the relevance of experiments in computing attracted little attention until the 1980s. As the discipline then saw a push towards experimental computer science, a variety of technically, theoretically, and empirically oriented views on experiments emerged. As a consequence of those debates, today's computing fields use experiments and experiment terminology in a variety of ways. This paper analyzes experimentation debates in computing. It presents five ways in which debaters have conceptualized experiments in computing: feasibility experiment, trial experiment, field experiment, comparison experiment, and controlled experiment. This paper has three aims: to clarify experiment terminology in computing; to contribute to disciplinary self-understanding of computing; and, due to computing's centrality in other fields, to promote understanding of experiments in modern science in general.

Going To The Field: Immersing Student Researchers in Coupled Human-Natural Systems

NASA Astrophysics Data System (ADS)

Weissmann, G. S.; Ibarra, R.

2014-12-01

Taking students into the field can offer a rich, grounded understanding of a particular environment and of a particular scientific approach to attaining a desired observation. Going into the field immerses students into coupled human-natural systems, which introduces two key elements to teaching: experiential learning and socio-cultural context. While these elements can greatly enrich student learning, instructors have to take extra steps to scaffold this learning. This scaffolding can present physical scientists with a challenge: how to reconcile views that such pedagogical activities are 'extraneous'/not central to the pursuit of physical science. Here we offer perspectives as an anthropologist and as an environmental scientist on the value of a diverse pedagogical approach to conducting field studies involving students. Insights drawn from facilitating a range of field experiences (e.g., short-term study abroad, service-learning and independent/supervised research both home and abroad) will be shared regarding approaches to scaffolding student learning. We will focus on an approach that the scholarship of teaching and learning has long shown to be effective - what can be called a "wrap-around" approach to the field: preparation before, support during, and reflection afterward. Of these steps, the post-trip reflection on the experience is a key, and often under-utilized, strategy, and suggestions as to why this are offered. This approach not only helps students understand better the course content, but it also helps them understand the role that socio-cultural context plays in shaping both the research and in the state of the environment. We illustrate these different dimensions of the field experience with examples from our courses.

Impacts of a gape limited Brook Trout, Salvelinus fontinalis, on larval Northwestern salamander, Ambystoma gracile, growth: A field enclosure experiment

USGS Publications Warehouse

Currens, C.R.; Liss, W.J.; Hoffman, R.L.

2007-01-01

The formation of amphibian population structure is directly affected by predation. Although aquatic predators have been shown to have direct negative effects on larval salamanders in laboratory and field experiments, the potential impacts of gape-limited fish on larval salamander growth has been largely underexplored. We designed an enclosure experiment conducted in situ to quantify the effects of gape-limited Brook Trout (Salvelinus fontinalis) on larval Northwestern Salamander (Ambystoma gracile) growth. We specifically tested whether the presence of fish too small to consume larvae had a negative effect on larval growth. The results of this study indicate that the presence of a gape-limited S. fontinalis can have a negative effect on growth of larval A. gracile salamanders. Copyright 2007 Society for the Study of Amphibians and Reptiles.

Utilizing geogebra in financial mathematics problems: didactic experiment in vocational college

NASA Astrophysics Data System (ADS)

Ghozi, Saiful; Yuniarti, Suci

2017-12-01

GeoGebra application offers users to solve real problems in geometry, statistics, and algebra fields. This studydeterminesthe effect of utilizing Geogebra on students understanding skill in the field of financial mathematics. This didactic experiment study used pre-test-post-test control group design. Population of this study were vocational college students in Banking and Finance Program of Balikpapan State Polytechnic. Two classes in the first semester were chosen using cluster random sampling technique, one class as experiment group and one class as control group. Data were analysed used independent sample t-test. The result of data analysis showed that students understanding skill with learning by utilizing GeoGeobra is better than students understanding skill with conventional learning. This result supported that utilizing GeoGebra in learning can assist the students to enhance their ability and depth understanding on mathematics subject.

Forum Theatre and Parables: A Qualitative Field Experiment in a Seventh-Day Adventist Academy

ERIC Educational Resources Information Center

Freed, Dena Davis

2012-01-01

In this article, the author describes a qualitative field study designed to test the effectiveness of Forum Theatre (FT) as a cross-disciplinary approach to Biblical parabolic literature analysis for students enrolled in a Seventh-day Adventist (SDA) Academy. The author provides a brief overview of the theoretical framework of the study, the study…

Early Urban Field Experiences for Prospective Teachers: A Case Study of Multicultural Field Placements through a University-Based Preservice STEM Teacher Program

ERIC Educational Resources Information Center

Segal, Eden H.

2011-01-01

Educational and political leaders have expressed concern about racial and ethnic disparities in students' readiness for postsecondary study and careers in science, technology, engineering, and mathematics (STEM). A lack of preparedness of STEM teachers in high-need urban districts, which serve predominantly low-income minority students, is often…

Impact of materials used in lab and field experiments on the recovery of organic micropollutants

NASA Astrophysics Data System (ADS)

Hebig, Klaus; Nödler, Karsten; Licha, Tobias; Scheytt, Traugott

2015-04-01

Organic micropollutants are frequently detected in the aquatic environment. There-fore, a large number of field and laboratory studies have been conducted in order to study their fate in the environment. Due to the diversity of chemical properties among these compounds some of them may interact with materials commonly used in field and laboratory studies like tubes, filters, or sample bottles. The aim of our experiment was to study the interaction between those materials and an aqueous solution of 43 widely detected basic, neutral, and acidic organic micropollutants hereby covering a broad range of polarities. Experiments with materials were conducted as a batch study using spiked tap water and for different syringe filters by filtration with subsequent fraction collection. The best recoveries over a wide range of organic compounds were observed for batches in contact with the following materials (in descending order) acryl glass, PTFE, HDPE, and PP. The use of Pharmed©, silicone, NBR70, Tygon©, and LDPE should be avoided. Flexible tubing materials especially influence many of the investigated compounds here. Filtration with most of the tested filter types leads to no significant loss of almost all of the investigated micropollutants. Nonetheless, significant mass losses of some compounds (loratadine, fluoxetine, sertraline, and diuron) were observed during the first mL of the filtration process. No systematic correlation between compound properties, tested materials, and ob-served mass losses could be identified in this study. The behavior of each compound is specific and thus, not predictable. It is therefore suggested to study the interaction of compounds with filters and material prior to the actual experiment or include blank studies.

International Field Experience--What Do Student Teachers Learn?

ERIC Educational Resources Information Center

Lee, Jackie Fung King

2011-01-01

This inquiry aimed to examine the benefits of having international field experience for a group of Hong Kong postgraduate student teachers who joined a six-week immersion programme in New Zealand. Through participants' reflections, interviews and programme evaluations, the present investigation found that the overseas field experience not only…

Life on the Reservation: Cross-Cultural Field Experiences and Student Learning

ERIC Educational Resources Information Center

Richardson, Belinda Conrad; Dinkins, Elizabeth G.

2014-01-01

Twenty-first century classrooms are filled with increasingly diverse student populations. Effective teacher preparation programs must include explicit course work in culturally responsive pedagogies and field experiences that place educators in new sociocultural contexts. Field experiences in cross-cultural, place-based settings have the potential…

Assisting Your Preservice Teacher to Be Successful during Field Experiences

ERIC Educational Resources Information Center

Brett, Christine

2006-01-01

Field experience (junior practicum and student teaching) is considered by many to be the most influential part of a teacher preparation program (Cruickshank & Aramalin, 1986; Tannehill & Zakrajsek, 1988). During field experiences, preservice teachers (hereafter referred to as PSTs) are guided by a cooperating teacher (hereafter referred to as a…

Preparing New Teachers: Operating Successful Field Experience Programs.

ERIC Educational Resources Information Center

Slick, Gloria Appelt, Ed.

This is the second in a series of four books presenting a variety of field experience program models and philosophies that drive the programs provided to preservice teachers during their undergraduate teacher preparation. This publication addresses the operational aspects of a successfully functioning field experience program and office. The…

ROLE OF LEAF SURFACE WATER IN BI-DIRECTIONAL AMMONIA EXCHANGE

EPA Science Inventory

A field experiment was conducted to study the ammonia exchange between plants and the atmosphere in a soybean field in North Carolina during the summer of 2002. In general, ammonia concentrations peak a few hours after sunrise. To investigate the mechanisms that control the exch...

Samplers for evaluation and quantification of ultra-low volume space sprays

USDA-ARS?s Scientific Manuscript database

A field study was conducted to investigate the suitability of sampling devices for quantification of spray deposition from ULV space sprays. Five different samplers were included in an experiment conducted in an open grassy field. Samplers included horizontally stretched stationary cotton ribbon at ...

Bioremediation of weathered petroleum hydrocarbon soil contamination in the Canadian High Arctic: laboratory and field studies.

PubMed

Sanscartier, David; Laing, Tamsin; Reimer, Ken; Zeeb, Barbara

2009-11-01

The bioremediation of weathered medium- to high-molecular weight petroleum hydrocarbons (HCs) in the High Arctic was investigated. The polar desert climate, contaminant characteristics, and logistical constraints can make bioremediation of persistent HCs in the High Arctic challenging. Landfarming (0.3 m(3) plots) was tested in the field for three consecutive years with plots receiving very little maintenance. Application of surfactant and fertilizers, and passive warming using a greenhouse were investigated. The field study was complemented by a laboratory experiment to better understand HC removal mechanisms and limiting factors affecting bioremediation on site. Significant reduction of total petroleum HCs (TPH) was observed in both experiments. Preferential removal of compounds nC16 occurred, whereas in the field, TPH reduction was mainly limited to removal of compounds nC16 was observed in the fertilized field plots only. The greenhouse increased average soil temperatures and extended the treatment season but did not enhance bioremediation. Findings suggest that temperature and low moisture content affected biodegradation of HCs in the field. Little volatilization was measured in the laboratory, but this process may have been predominant in the field. Low-maintenance landfarming may be best suited for remediation of HCs compounds

Potential effect of fiddler crabs on organic matter distribution: A combined laboratory and field experimental approach

NASA Astrophysics Data System (ADS)

Natálio, Luís F.; Pardo, Juan C. F.; Machado, Glauco B. O.; Fortuna, Monique D.; Gallo, Deborah G.; Costa, Tânia M.

2017-01-01

Bioturbators play a key role in estuarine environments by modifying the availability of soil elements, which in turn may affect other organisms. Despite the importance of bioturbators, few studies have combined both field and laboratory experiments to explore the effects of bioturbators on estuarine soils. Herein, we assessed the bioturbation potential of fiddler crabs Leptuca leptodactyla and Leptuca uruguayensis in laboratory and field experiments, respectively. We evaluated whether the presence of fiddler crabs resulted in vertical transport of sediment, thereby altering organic matter (OM) distribution. Under laboratory conditions, the burrowing activity by L. leptodactyla increased the OM content in sediment surface. In the long-term field experiment with areas of inclusion and exclusion of L. uruguayensis, we did not observe influence of this fiddler crab in the vertical distribution of OM. Based on our results, we suggest that small fiddler crabs, such as the species used in these experiments, are potentially capable of alter their environment by transporting sediment and OM but such effects may be masked by environmental drivers and spatial heterogeneity under natural conditions. This phenomenon may be related to the small size of these species, which affects how much sediment is transported, along with the way OM interacts with biogeochemical and physical processes. Therefore, the net effect of these burrowing organisms is likely to be the result of a complex interaction with other environmental factors. In this sense, we highlight the importance of performing simultaneous field and laboratory experiments in order to better understanding the role of burrowing animals as bioturbators.

First Year Teacher of First Year Teachers: A Reflection on Teacher Training in the Field of Piano Pedagogy

ERIC Educational Resources Information Center

Elgersma, Kristin

2012-01-01

While there is a great deal of scholarly inquiry focusing on student teaching experiences in the field of classroom education, there are few resources devoted to student teaching in the context of the applied music lesson. In this article, a teacher educator in the field of piano pedagogy uses self-study to combine reflection on personal…

Re-Examining Format Distortion and Orthographic Neighbourhood Size Effects in the Left, Central and Right Visual Fields

ERIC Educational Resources Information Center

Mano, Quintino R.; Patrick, Cory J.; Andresen, Elizabeth N.; Capizzi, Kyle; Biagioli, Raschel; Osmon, David C.

2010-01-01

Research has shown orthographic neighbourhood size effects (ONS) in the left visual field (LVF) but not in the right visual field (RVF). An earlier study examined the combined effects of ONS and font distortion in the LVF and RVF, but did not find an interaction. The current lexical decision experiment re-examined the interaction between ONS and…

Ten-Minute Field Trips. A Teacher's Guide to Using the Schoolgrounds for Environmental Studies. Second Edition.

ERIC Educational Resources Information Center

Russell, Helen Ross

This book has been written to help teachers learn with their students and discover the advantages of using their own school ground for field trips. Since every school ground is different and since all field trips should be a part of classroom experiences, this book can only suggest possibilities that the teacher can select and adapt as a starting…

The Neural Basis of the Right Visual Field Advantage in Reading: An MEG Analysis Using Virtual Electrodes

ERIC Educational Resources Information Center

Barca, Laura; Cornelissen, Piers; Simpson, Michael; Urooj, Uzma; Woods, Will; Ellis, Andrew W.

2011-01-01

Right-handed participants respond more quickly and more accurately to written words presented in the right visual field (RVF) than in the left visual field (LVF). Previous attempts to identify the neural basis of the RVF advantage have had limited success. Experiment 1 was a behavioral study of lateralized word naming which established that the…

Field experiment evidence of substantive, attributional, and behavioral persuasion by members of Congress in online town halls.

PubMed

Minozzi, William; Neblo, Michael A; Esterling, Kevin M; Lazer, David M J

2015-03-31

Do leaders persuade? Social scientists have long studied the relationship between elite behavior and mass opinion. However, there is surprisingly little evidence regarding direct persuasion by leaders. Here we show that political leaders can persuade their constituents directly on three dimensions: substantive attitudes regarding policy issues, attributions regarding the leaders' qualities, and subsequent voting behavior. We ran two randomized controlled field experiments testing the causal effects of directly interacting with a sitting politician. Our experiments consist of 20 online town hall meetings with members of Congress conducted in 2006 and 2008. Study 1 examined 19 small meetings with members of the House of Representatives (average 20 participants per town hall). Study 2 examined a large (175 participants) town hall with a senator. In both experiments we find that participating has significant and substantively important causal effects on all three dimensions of persuasion but no such effects on issues that were not discussed extensively in the sessions. Further, persuasion was not driven solely by changes in copartisans' attitudes; the effects were consistent across groups.

Field experiment evidence of substantive, attributional, and behavioral persuasion by members of Congress in online town halls

PubMed Central

Minozzi, William; Neblo, Michael A.; Esterling, Kevin M.; Lazer, David M. J.

2015-01-01

Do leaders persuade? Social scientists have long studied the relationship between elite behavior and mass opinion. However, there is surprisingly little evidence regarding direct persuasion by leaders. Here we show that political leaders can persuade their constituents directly on three dimensions: substantive attitudes regarding policy issues, attributions regarding the leaders’ qualities, and subsequent voting behavior. We ran two randomized controlled field experiments testing the causal effects of directly interacting with a sitting politician. Our experiments consist of 20 online town hall meetings with members of Congress conducted in 2006 and 2008. Study 1 examined 19 small meetings with members of the House of Representatives (average 20 participants per town hall). Study 2 examined a large (175 participants) town hall with a senator. In both experiments we find that participating has significant and substantively important causal effects on all three dimensions of persuasion but no such effects on issues that were not discussed extensively in the sessions. Further, persuasion was not driven solely by changes in copartisans’ attitudes; the effects were consistent across groups. PMID:25775516

Convection and dendrite crystallization. [during coasting phase of sounding rocket flight

NASA Technical Reports Server (NTRS)

Grodzka, P. G.; Johnston, M. H.; Griner, C. S.

1977-01-01

The convection and thermal conditions in aqueous and metallic liquid systems under conditions of the Dendrite Remelting Rocket Experiment were assessed to help establish the relevance of the rocket experiment to the metals casting phenomena. The results of the study indicate that aqueous or metallic convection velocities in the cell are of insignificant magnitudes at the 0.0001 to 0.00001 g levels of the experiment. The crystallization phenomena observed in the rocket experiment, therefore, may be indicative of how metals will solidify in low-g. The influence of possibly differing thermal fields, however, remains to be assessed. The rocket experiment may also be relevant to how metals solidify on the ground at temperature differences and in cell configurations such that the flow velocities are not high enough to break or bend delicate dendrite arms. Again, however, the influence of the thermal fields must be assessed.

Pesticide storage and release in unsaturated soil in Illinois, USA

USGS Publications Warehouse

Roy, W.R.; Krapac, I.G.; Chou, S.-F.J.; Simmons, F.W.

2001-01-01

The chemical fate and movement of pesticides may be subject to transient storage in unsaturated soils during periods of light rainfall, and subsequent release into shallow groundwater by increased rainfall. The objective of this study was to conduct field-scale experiments to determine the relative importance of transient storage and subsequent release of agrichemicals from the vadose zone into potential aquifers. Two field-scale experiments were conducted under a rain exclusion shelter. In the 1 x experiment, atrazine and chlorpyrifos were applied at application-rate equivalents (1.6 kg ha-1 and 1.3 kg ha-1, respectively). In the 4x experiment, atrazine was applied in an amount that was four times greater than that usually applied to fields (6.7 kg ha-1). Water was either applied to simulate rain or withheld to simulate dry periods. In the 1 x experiment, atrazine was detected in the water samples whereas chlorpyrifos was not detected in the majority of the samples. The dry period imposed on the treatment plot did not appear to result in storage of the chemicals, whereas the wet period resulted in greater leaching of atrazine, although the concentrations remained less than the Maximum Contaminant Level of 3 ?? L-1. Both chemicals were detected in soil samples collected from a 20- to 30-cm depth, but it appeared that both chemicals dissipated before the field experiment was concluded. It appeared that the one-time application of atrazine and chlorpyrifos at the label rates did not result in a sufficient mass to be stored and flushed in significant concentrations to the saturated zone. When atrazine was applied at 4x and a longer drought period was imposed on the treatment plot, the resulting concentrations of dissolved atrazine were still less than 3 ??g L-1. Atrazine was detected in only the near-surface (0 to 15 cm) soil samples and the herbicide dissipated before the onset of the dry period in the treatment plot. The results of this field study demonstrated that atrazine and chlorpyrifos were not sufficiently persistent to be stored and then released in significantly large concentrations to the saturated zone. The dissipation half-life of atrazine in the 4x application was about 44 days. This study, in addition to others, suggested that atrazine may be less persistent in surface soil than has been generally reported.

The Influence of an Extensive Inquiry-Based Field Experience on Pre-Service Elementary Student Teachers' Science Teaching Beliefs

NASA Astrophysics Data System (ADS)

Bhattacharyya, Sumita; Volk, Trudi; Lumpe, Andrew

2009-06-01

This study examined the effects of an extensive inquiry-based field experience on pre service elementary teachers’ personal agency beliefs, a composite measure of context beliefs and capability beliefs related to teaching science. The research combined quantitative and qualitative approaches and included an experimental group that utilized the inquiry method and a control group that used traditional teaching methods. Pre- and post-test scores for the experimental and control groups were compared. The context beliefs of both groups showed no significant change as a result of the experience. However, the control group’s capability belief scores, lower than those of the experimental group to start with, declined significantly; the experimental group’s scores remained unchanged. Thus, the inquiry-based field experience led to an increase in personal agency beliefs. The qualitative data suggested a new hypothesis that there is a spiral relationship among teachers’ ability to establish communicative relationships with students, desire for personal growth and improvement, ability to implement multiple instructional strategies, and possession of substantive content knowledge. The study concludes that inquiry-based student teaching should be encouraged in the training of elementary school science teachers. However, the meaning and practice of the inquiry method should be clearly delineated to ensure its correct implementation in the classroom.

Electromagnetic containerless undercooling facility and experiments for the Shuttle

NASA Technical Reports Server (NTRS)

Frost, R. T.; Flemings, M. C.; Szekely, J.; El-Kaddah, N.; Shiohara, Y.

1984-01-01

An electromagnetic furnace is being prepared for flights aboard the Space Shuttle. This apparatus is capable of melting metals and alloys up to 1400 C melting point by induction heating with subsequent solidification of the freely levitated melt without contact with any container. The solidification can be carried out with greatly reduced fields resulting in minimal heating and stirring of the free melt. Sequential specimens can be processed during flight. Several experiments are planned for a series of flights, beginning in 1985 with an undercooling experiment of NiSn alloys. These will be interspersed with detailed studies of fluid flow caused by low and high field levels in order to quantify the corresponding effect upon the solidification process.

29 CFR 1960.56 - Training of safety and health specialists.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., laboratory experiences, field study, and other formal learning experiences to prepare them to perform the... program development and implementation, as well as hazard recognition, evaluation and control, equipment... tasks. (b) Each agency shall implement career development programs for their occupational safety and...

Cybersickness and desktop simulations: field of view effects and user experience

NASA Astrophysics Data System (ADS)

Toet, Alexander; de Vries, Sjoerd C.; van Emmerik, Martijn L.; Bos, Jelte E.

2008-04-01

We used a desktop computer game environment to study the effect Field-of-View (FOV) on cybersickness. In particular, we examined the effect of differences between the internal FOV (iFOV, the FOV which the graphics generator is using to render its images) and the external FOV (eFOV, the FOV of the presented images as seen from the physical viewpoint of the observer). Somewhat counter-intuitively, we find that congruent iFOVs and eFOVs lead to a higher incidence of cybersickness. A possible explanation is that the incongruent conditions were too extreme, thereby reducing the experience of vection. We also studied the user experience (appraisal) of this virtual environment as a function of the degree of cybersickness. We find that cybersick participants experience the simulated environment as less pleasant and more arousing, and possibly also as more distressing. Our present findings have serious implications for desktop simulations used both in military and in civilian training, instruction and planning applications.

Study of Fluid Flow Control in Protein Crystallization using Strong Magnetic Fields

NASA Astrophysics Data System (ADS)

Ramachandran, Narayanan; Leslie, Fred; Ciszak, Ewa

2002-11-01

An important component in biotechnology, particularly in the area of protein engineering and rational drug design is the knowledge of the precise three-dimensional molecular structure of proteins. The quality of structural information obtained from X-ray diffraction methods is directly dependent on the degree of perfection of the protein crystals. As a consequence, the growth of high quality macromolecular crystals for diffraction analyses has been the central focus for biochemists, biologists, and bioengineers. Macromolecular crystals are obtained from solutions that contain the crystallizing species in equilibrium with higher aggregates, ions, precipitants, other possible phases of the protein, foreign particles, the walls of the container, and a likely host of other impurities. By changing transport modes in general, i.e., reduction of convection and sedimentation, as is achieved in "microgravity", researchers have been able to dramatically affect the movement and distribution of macromolecules in the fluid, and thus their transport, formation of crystal nuclei, and adsorption to the crystal surface. While a limited number of high quality crystals from space flights have been obtained, as the recent National Research Council (NRC) review of the NASA microgravity crystallization program pointed out, the scientific approach and research in crystallization of proteins has been mainly empirical yielding inconclusive results. We postulate that we can reduce convection in ground-based experiments and we can understand the different aspects of convection control through the use of strong magnetic fields and field gradients. Whether this limited convection in a magnetic field will provide the environment for the growth of high quality crystals is still a matter of conjecture that our research will address. The approach exploits the variation of fluid magnetic susceptibility with concentration for this purpose and the convective damping is realized by appropriately positioning the crystal growth cell so that the magnetic susceptibility force counteracts terrestrial gravity. The general objective is to test the hypothesis of convective control using a strong magnetic field and magnetic field gradient and to understand the nature of the various forces that come into play. Specifically we aim to delineate causative factors and to quantify them through experiments, analysis and numerical modeling. Once the basic understanding is obtained, the study will focus on testing the hypothesis on proteins of pyruvate dehydrogenase complex (PDC), proteins E1 and E3. Obtaining high crystal quality of these proteins is of great importance to structural biologists since their structures need to be determined. Specific goals for the investigation are: 1. To develop an understanding of convection control in diamagnetic fluids with concentration gradients through experimentation and numerical modeling. Specifically solutal buoyancy driven convection due to crystal growth will be considered. 2. To develop predictive measures for successful crystallization in a magnetic field using analyses and numerical modeling for use in future protein crystal growth experiments. This will establish criteria that can be used to estimate the efficacy of magnetic field flow damping on crystallization of candidate proteins. 3. To demonstrate the understanding of convection damping by high magnetic fields to a class of proteins that is of interest and whose structure is as yet not determined. 4. To compare quantitatively, the quality of the grown crystals with and without a magnetic field. X-ray diffraction techniques will be used for the comparative studies. In a preliminary set of experiments, we studied crystal dissolution effects in a 5 Tesla magnet available at NASA Marshall Space Flight Center (MSFC). Using a Schlieren setup, a 1mm crystal of Alum (Aluminum-Potassium Sulfate) was introduced in a 75% saturated solution and the resulting dissolution plume was observed. The experiment was conducted both in the presence and absence of a magnetic field gradient. The magnet produces a gradient field of approx. 1 Tesla2/cm. Image analysis of the recorded images indicated an enhanced plume velocity that was of the order of the measurement limit. For this experiment, both the gradient and gravity fields are in the same direction resulting in an enhanced effective gravity that tends to accelerate the observed plume velocity. While the results are not conclusive, pending further tests, it clearly points out the inadequacy of the MSFC magnet for conducting protein crystallization experiments and the need for a stronger magnet. In spacebased experiments, however, where the gravitational effects are small, only a weak magnetic field will be required to control or mitigate the effects of convective contamination.

Study of Fluid Flow Control in Protein Crystallization using Strong Magnetic Fields

NASA Technical Reports Server (NTRS)

Ramachandran, Narayanan; Leslie, Fred; Ciszak, Ewa

2002-01-01

An important component in biotechnology, particularly in the area of protein engineering and rational drug design is the knowledge of the precise three-dimensional molecular structure of proteins. The quality of structural information obtained from X-ray diffraction methods is directly dependent on the degree of perfection of the protein crystals. As a consequence, the growth of high quality macromolecular crystals for diffraction analyses has been the central focus for biochemists, biologists, and bioengineers. Macromolecular crystals are obtained from solutions that contain the crystallizing species in equilibrium with higher aggregates, ions, precipitants, other possible phases of the protein, foreign particles, the walls of the container, and a likely host of other impurities. By changing transport modes in general, i.e., reduction of convection and sedimentation, as is achieved in "microgravity", researchers have been able to dramatically affect the movement and distribution of macromolecules in the fluid, and thus their transport, formation of crystal nuclei, and adsorption to the crystal surface. While a limited number of high quality crystals from space flights have been obtained, as the recent National Research Council (NRC) review of the NASA microgravity crystallization program pointed out, the scientific approach and research in crystallization of proteins has been mainly empirical yielding inconclusive results. We postulate that we can reduce convection in ground-based experiments and we can understand the different aspects of convection control through the use of strong magnetic fields and field gradients. Whether this limited convection in a magnetic field will provide the environment for the growth of high quality crystals is still a matter of conjecture that our research will address. The approach exploits the variation of fluid magnetic susceptibility with concentration for this purpose and the convective damping is realized by appropriately positioning the crystal growth cell so that the magnetic susceptibility force counteracts terrestrial gravity. The general objective is to test the hypothesis of convective control using a strong magnetic field and magnetic field gradient and to understand the nature of the various forces that come into play. Specifically we aim to delineate causative factors and to quantify them through experiments, analysis and numerical modeling. Once the basic understanding is obtained, the study will focus on testing the hypothesis on proteins of pyruvate dehydrogenase complex (PDC), proteins E1 and E3. Obtaining high crystal quality of these proteins is of great importance to structural biologists since their structures need to be determined. Specific goals for the investigation are: 1. To develop an understanding of convection control in diamagnetic fluids with concentration gradients through experimentation and numerical modeling. Specifically solutal buoyancy driven convection due to crystal growth will be considered. 2. To develop predictive measures for successful crystallization in a magnetic field using analyses and numerical modeling for use in future protein crystal growth experiments. This will establish criteria that can be used to estimate the efficacy of magnetic field flow damping on crystallization of candidate proteins. 3. To demonstrate the understanding of convection damping by high magnetic fields to a class of proteins that is of interest and whose structure is as yet not determined. 4. To compare quantitatively, the quality of the grown crystals with and without a magnetic field. X-ray diffraction techniques will be used for the comparative studies. In a preliminary set of experiments, we studied crystal dissolution effects in a 5 Tesla magnet available at NASA Marshall Space Flight Center (MSFC). Using a Schlieren setup, a 1mm crystal of Alum (Aluminum-Potassium Sulfate) was introduced in a 75% saturated solution and the resulting dissolution plume was observed. The experiment was conducted both in the presence and absence of a magnetic field gradient. The magnet produces a gradient field of approx. 1 Tesla2/cm. Image analysis of the recorded images indicated an enhanced plume velocity that was of the order of the measurement limit. For this experiment, both the gradient and gravity fields are in the same direction resulting in an enhanced effective gravity that tends to accelerate the observed plume velocity. While the results are not conclusive, pending further tests, it clearly points out the inadequacy of the MSFC magnet for conducting protein crystallization experiments and the need for a stronger magnet. In spacebased experiments, however, where the gravitational effects are small, only a weak magnetic field will be required to control or mitigate the effects of convective contamination.

The protection of parsley seedlings (Petroselinum sativum Hoffm. ssp. microcarpum) against damping-off.

PubMed

Nawrocki, J

2006-01-01

The experiment was carried out in the years 2003 and 2004 on parsley cultivar: 'Berlinska', 'Cukrowa', 'Vistula' and 'Kinga'. Mycological analysis of parsley seeds showed, that the most common inhabitans were fungi from genus Alternaria (mainly A. alternata and A. radicina) and Fusarium, especially F. avenaceum and F. oxysporum. The two-year study on the effectiveness of 5 substances--biopreparate Biochikol 020 PC (polymer of chitosol) and Biosept 33 SL (extract of grape-fruit); and fungicides: Amistar 250 SC (BAS azoxystrobin), Dithane M-45 80WP (mancozeb) and Zaprawa Funaben T (carbendazim+thiram) used against parsley damping-off was conducted in glasshouse and field conditions. Seeds of parsley were treated one of tested substances before sowing. The results of glasshouse experiments showed, that the best efficacy exibited Amistar and Zaprawa Funaben T for seedlings cultivar 'Berlińska' and 'Cukrowa' and Biochikol for 'Kinga'. During field experiments Zaprawa Funaben T showed the best efficacy for seedlings 'Berlińska' and 'Vistula'. Preparate Amistar was the best seed dressing for parsley cultivar 'Cukrowa' and 'Kinga'. During glasshouse experiments in control the highest number of decaying seedlings had cultivar 'Berlinska', in field experiments 'Kinga'.

Children's environmental knowing: A case study of children's experiences during an environmental education programme

NASA Astrophysics Data System (ADS)

Scott, Sandra Anne

This study explores children's experiences during WaterWorlds (pseudonym) a field-based environmental education programme at a marine science centre. The study objectives were to investigate how children understand and interpret their experiences, and how these experiences foster their environmental knowing. To address these objectives, I carried out a case study at a marine science centre in British Columbia. I examined children's WaterWorlds experiences and explored their environmental understandings and commitment to environmental action. I analysed the experiences of children in four separate classes and carried out an in-depth examination of four individual children. Data were collected using informal semi-structured interviews, observations, conversations, researcher journal logs, and student documents including their writing and illustrations. My findings indicate that the WaterWorlds programme experience fosters children's environmental knowing. Participation in WaterWorlds activities led to connection, caring, and concern for other species and in some cases, for the marine environment as a whole. During the programme, children chose the ways they interpreted and expressed their environmental knowledge, ethic of care, advocacy, and commitment to action. This development of each child's self-expression resulted in motivational and powerful learning experiences that inspired and nurtured their connections to the earth. This research provides evidence and examples of how educators can foster children's environmental knowing through multi-disciplinary environmental education experiences. It illustrates that activities such as observing and documenting the lives of other animal species, collecting data and conducting research on those species, and working and learning alongside experts in the field of environmental education are powerful experiences that motivate concern and care for the earth among children.

Experimental studies in fluid mechanics and materials science using acoustic levitation

NASA Technical Reports Server (NTRS)

Trinh, E. H.; Robey, J.; Arce, A.; Gaspar, M.

1987-01-01

Ground-based and short-duration low gravity experiments have been carried out with the use of ultrasonic levitators to study the dynamics of freely suspended liquid drops under the influence of predominantly capillary and acoustic radiation forces. Some of the effects of the levitating field on the shape as well as the fluid flow fields within the drop have been determined. The development and refinement of measurement techniques using levitated drops with size on the order of 2 mm in diameter have yielded methods having direct application to experiments in microgravity. In addition, containerless melting, undercooling, and freezing of organic materials as well as low melting metals have provided experimental data and observations on the application of acoustic positioning techniques to materials studies.

Simultaneous Analyses and Applications of Multiple Fluorobenzoate and Halide Tracers in Hydrologic Studies

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

Hu, Q; Moran, J E

2004-01-22

An analytical method that employs ion chromatography has been developed to more fully exploit the use of fluorobenzoic acids (FBAs) and halides as hydrologic tracers. In a single run, this reliable, sensitive, and robust method can simultaneously separate and quantify halides (fluoride, chloride, bromide, and iodide) and up to seven FBAs from other common groundwater constituents (e.g., nitrate and sulfate). The usefulness of this ion chromatographic (IC) analytical method is demonstrated in both field and laboratory tracer experiments. Field experiments in unsaturated tuff featuring fractures or a fault show that this efficient and cost-effective method helps achieve the objectives ofmore » tracer studies that use multiple FBAs and/or diffusivity tracers (simultaneous use of one or more FBA and halide). The field study examines the hydrologic response of fractures and the matrix to different flow rates and the contribution of matrix diffusion in chemical transport. Laboratory tracer experiments with eight geologic media from across the United States--mostly from Department of Energy facilities where groundwater contamination is prevalent and where subsurface characterization employing tracers has been ongoing or is in need--reveal several insights about tracer transport behavior: (1) Bromide and FBAs are not always transported conservatively. (2) The delayed transport of these anionic tracers is likely related to geologic media characteristics, such as organic matter, pH, iron oxide content, and clay mineralogy. (3) Any use of iodine as a hydrologic tracer should take into account the different sorption behaviors of iodide and iodate and the possible conversion of iodine's initial chemical form. (4) The transport behavior of potential FBA and halide tracers under relevant geochemical conditions should be evaluated before beginning ambitious, large-scale field tracer experiments.« less

Soil Conditions That Can Alter Natural Suppression of Escherichia coli O157:H7 in Ohio Specialty Crop Soils

PubMed Central

Williams, Michele L.; LeJeune, Jeffrey T.

2015-01-01

Food-borne pathogen persistence in soil fundamentally affects the production of safe vegetables and small fruits. Interventions that reduce pathogen survival in soil would have positive impacts on food safety by minimizing preharvest contamination entering the food chain. Laboratory-controlled studies determined the effects of soil pH, moisture content, and soil organic matter (SOM) on the survivability of this pathogen through the creation of single-parameter gradients. Longitudinal field-based studies were conducted in Ohio to quantify the extent to which field soils suppressed Escherichia coli O157:H7 survival. In all experiments, heat-sensitive microorganisms were responsible for the suppression of E. coli O157 in soil regardless of the chemical composition of the soil. In laboratory-based studies, soil pH and moisture content were primary drivers of E. coli O157 survival, with increases in pH after 48 h (P = 0.02) and decreases in moisture content after 48 h (P = 0.007) significantly increasing the log reduction of E. coli O157 numbers. In field-based experiments, E. coli O157 counts from both heated and unheated samples were sensitive to both season (P = 0.004 for heated samples and P = 0.001 for unheated samples) and region (P = 0.002 for heated samples and P = 0.001 for unheated samples). SOM was observed to be a more significant driver of pathogen suppression than the other two factors after 48 h at both planting and harvest (P = 0.002 at planting and P = 0.058 at harvest). This research reinforces the need for both laboratory-controlled experiments and longitudinal field-based experiments to unravel the complex relationships controlling the survival of introduced organisms in soil. PMID:25934621

Emissions of PCDD and PCDF from combustion of forest fuels and sugarcane: a comparison between field measurements and simulations in a laboratory burn facility.

PubMed

Black, R R; Meyer, C P; Touati, A; Gullett, B K; Fiedler, H; Mueller, J F

2011-05-01

Release of PCDD and PCDF from biomass combustion such as forest and agricultural crop fires has been nominated as an important source for these chemicals despite minimal characterisation. Available emission factors that have been experimentally determined in laboratory and field experiments vary by several orders of magnitude from <0.5 μg TEQ (t fuel consumed)(-1) to >100 μg TEQ (t fuel consumed)(-1). The aim of this study was to evaluate the effect of experimental methods on the emission factor. A portable field sampler was used to measure PCDD/PCDF emissions from forest fires and the same fuel when burnt over a brick hearth to eliminate potential soil effects. A laboratory burn facility was used to sample emissions from the same fuels. There was very good agreement in emission factors to air (EF(Air)) for forest fuel (Duke Forest, NC) of 0.52 (range: 0.40-0.79), 0.59 (range: 0.18-1.2) and 0.75 (range: 0.27-1.2) μg TEQ(WHO2005) (t fuel consumed)(-1) for the in-field, over a brick hearth, and burn facility experiments, respectively. Similarly, experiments with sugarcane showed very good agreement with EF(Air) of 1.1 (range: 0.40-2.2), 1.5 (range: 0.84-2.2) and 1.7 (range: 0.34-4.4) μg TEQ (t fuel consumed)(-1) for in-field, over a brick hearth, open field and burn facility experiments respectively. Field sampling and laboratory simulations were in good agreement, and no significant changes in emissions of PCDD/PCDF could be attributed to fuel storage and transport to laboratory test facilities. Copyright © 2011 Elsevier Ltd. All rights reserved.

Females and STEM: Determining the K-12 Experiences that Influenced Women to Pursue STEM Fields

NASA Astrophysics Data System (ADS)

Petersen, Anne Marie

In the United States, careers in the fields of Science, Technology, Engineering, and Mathematics (STEM) are increasing yet there are not enough trained personnel to meet this demand. In addition, of those that seek to pursue STEM fields in the United States, only 26% are female. In order to increase the number of women seeking STEM based bachelor's degrees, K-12 education must provide a foundation that prepares students for entry into these fields. The purpose of this phenomenological study was to determine the perceived K-12 experiences that influenced females to pursue a STEM field. Twelve college juniors or seniors seeking a degree in Biology, Mathematics, or Physics were interviewed concerning their K-12 experiences. These interviews were analyzed and six themes emerged. Teacher passion and classroom characteristics such as incorporating challenging activities played a significant role in the females' decisions to enter STEM fields. Extra-curricular activities such as volunteer and mentor opportunities and the females' need to benefit others also influenced females in their career choice. Both the formal (within the school) and informal (outside of the traditional classroom) pipeline opportunities that these students encountered helped develop a sense of self-efficacy in science and mathematics; this self-efficacy enabled them to persist in pursuing these career fields. Several participants cited barriers that they encountered in K-12 education, but these barriers were primarily internal as they struggled with overcoming self-imposed obstacles in learning and being competitive in the mathematics and science classrooms. The experiences from these female students can be used by K-12 educators to prepare and encourage current female students to enter STEM occupations.

Elimination of the Reaction Rate "Scale Effect": Application of the Lagrangian Reactive Particle-Tracking Method to Simulate Mixing-Limited, Field-Scale Biodegradation at the Schoolcraft (MI, USA) Site

NASA Astrophysics Data System (ADS)

Ding, Dong; Benson, David A.; Fernández-Garcia, Daniel; Henri, Christopher V.; Hyndman, David W.; Phanikumar, Mantha S.; Bolster, Diogo

2017-12-01

Measured (or empirically fitted) reaction rates at groundwater remediation sites are typically much lower than those found in the same material at the batch or laboratory scale. The reduced rates are commonly attributed to poorer mixing at the larger scales. A variety of methods have been proposed to account for this scaling effect in reactive transport. In this study, we use the Lagrangian particle-tracking and reaction (PTR) method to simulate a field bioremediation experiment at the Schoolcraft, MI site. A denitrifying bacterium, Pseudomonas Stutzeri strain KC (KC), was injected to the aquifer, along with sufficient substrate, to degrade the contaminant, carbon tetrachloride (CT), under anaerobic conditions. The PTR method simulates chemical reactions through probabilistic rules of particle collisions, interactions, and transformations to address the scale effect (lower apparent reaction rates for each level of upscaling, from batch to column to field scale). In contrast to a prior Eulerian reaction model, the PTR method is able to match the field-scale experiment using the rate coefficients obtained from batch experiments.

Effects of turbulence, resistivity and boundary conditions on helicoidal flow collimation: Consequences for the Von-Kármán-Sodium dynamo experiment

DOE PAGES

Varela, J.; Oak Ridge National Lab.; Brun, S.; ...

2017-05-01

We present hydrodynamic and magneto-hydrodynamic simulations of a liquid sodium flow using the compressible MHD code PLUTO to investigate the magnetic field regeneration in the Von-Karman-Sodium dynamo experiment. The aim of the study is to analyze influence of the fluid resistivity and turbulence level on the collimation by helicoidal motions of a remnant magnetic field. We use a simplified cartesian geometry to represent the flow dynamics in the vicinity of one cavity of a multi-blades impeller inspired by those used in the Von-Karman-Sodium (VKS) experiment. We perform numerical simulations with kinetic Reynolds numbers up to 1000 for magnetic Prandtl numbersmore » between 30 and 0.1. Our study shows that perfect ferromagnetic walls favour enhanced collimation of flow and magnetic fields even if the turbulence degree of the model increases. More specifically the location of the helicoidal coherent vortex in between the blades changes with the impinging velocity. It becomes closer to the upstream blade and impeller base if the flow incident angle is analogous to the TM73 impeller configuration rotating in the unscooping direction. This result is also obtained at higher kinetic Reynolds numbers when the helicoidal vortex undergoes a precessing motion, leading to a reinforced effect in the vortex evolution and in the magnetic field collimation when using again perfect ferromagnetic boundary conditions. Configurations with different materials used for the impeller blades and impeller base confirm a larger enhancement of the magnetic field when perfect ferromagnetic boundary conditions are used compared with the perfect conductor case, although smaller than with a perfect ferromagnetic impeller, as it was observed in the VKS experiment. We further estimate the efficiency of a hypothetical dynamo loop occurring in the vicinity of the impeller and discuss the relevance of our findings in the context of mean field dynamo theory.« less

Effects of turbulence, resistivity and boundary conditions on helicoidal flow collimation: Consequences for the Von-Kármán-Sodium dynamo experiment

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

Varela, J.; Oak Ridge National Lab.; Brun, S.

We present hydrodynamic and magneto-hydrodynamic simulations of a liquid sodium flow using the compressible MHD code PLUTO to investigate the magnetic field regeneration in the Von-Karman-Sodium dynamo experiment. The aim of the study is to analyze influence of the fluid resistivity and turbulence level on the collimation by helicoidal motions of a remnant magnetic field. We use a simplified cartesian geometry to represent the flow dynamics in the vicinity of one cavity of a multi-blades impeller inspired by those used in the Von-Karman-Sodium (VKS) experiment. We perform numerical simulations with kinetic Reynolds numbers up to 1000 for magnetic Prandtl numbersmore » between 30 and 0.1. Our study shows that perfect ferromagnetic walls favour enhanced collimation of flow and magnetic fields even if the turbulence degree of the model increases. More specifically the location of the helicoidal coherent vortex in between the blades changes with the impinging velocity. It becomes closer to the upstream blade and impeller base if the flow incident angle is analogous to the TM73 impeller configuration rotating in the unscooping direction. This result is also obtained at higher kinetic Reynolds numbers when the helicoidal vortex undergoes a precessing motion, leading to a reinforced effect in the vortex evolution and in the magnetic field collimation when using again perfect ferromagnetic boundary conditions. Configurations with different materials used for the impeller blades and impeller base confirm a larger enhancement of the magnetic field when perfect ferromagnetic boundary conditions are used compared with the perfect conductor case, although smaller than with a perfect ferromagnetic impeller, as it was observed in the VKS experiment. We further estimate the efficiency of a hypothetical dynamo loop occurring in the vicinity of the impeller and discuss the relevance of our findings in the context of mean field dynamo theory.« less

Effects of turbulence, resistivity and boundary conditions on helicoidal flow collimation: Consequences for the Von-Kármán-Sodium dynamo experiment

NASA Astrophysics Data System (ADS)

Varela, J.; Brun, S.; Dubrulle, B.; Nore, C.

2017-05-01

We present hydrodynamic and magneto-hydrodynamic simulations of a liquid sodium flow using the compressible MHD code PLUTO to investigate the magnetic field regeneration in the Von-Kármán-Sodium dynamo experiment. The aim of the study is to analyze the influence of the fluid resistivity and turbulence level on the collimation by helicoidal motions of a remnant magnetic field. We use a simplified Cartesian geometry to represent the flow dynamics in the vicinity of one cavity of a multi-blades impeller inspired by those used in the Von-Kármán-Sodium (VKS) experiment. We perform numerical simulations with kinetic Reynolds numbers up to 1000 for magnetic Prandtl numbers between 30 and 0.1. Our study shows that perfect ferromagnetic walls favour enhanced collimation of flow and magnetic fields even if the turbulence degree of the model increases. More specifically, the location of the helicoidal coherent vortex in between the blades changes with the impinging velocity. It becomes closer to the upstream blade and the impeller base if the flow incident angle is analogous to the TM73 impeller configuration rotating in the unscooping direction. This result is also obtained at higher kinetic Reynolds numbers when the helicoidal vortex undergoes a precessing motion, leading to a reinforced effect in the vortex evolution and in the magnetic field collimation when using again perfect ferromagnetic boundary conditions. Configurations with different materials used for the impeller blades and the impeller base confirm a larger enhancement of the magnetic field when perfect ferromagnetic boundary conditions are used compared with the perfect conductor case, although smaller compared to a perfect ferromagnetic impeller, as it was observed in the VKS experiment. We further estimate the efficiency of a hypothetical dynamo loop occurring in the vicinity of the impeller and discuss the relevance of our findings in the context of mean field dynamo theory.

Experiments on H2-O2MHD power generation

NASA Technical Reports Server (NTRS)

Smith, J. M.

1980-01-01

Magnetohydrodynamic power generation experiments utilizing a cesium-seeded H2-O2 working fluid were carried out using a diverging area Hall duct having an entrance Mach number of 2. The experiments were conducted in a high-field strength cryomagnet facility at field strengths up to 5 tesla. The effects of power takeoff location, axial duct location within the magnetic field, generator loading, B-field strength, and electrode breakdown voltage were investigated. For the operating conditions of these experiments, it is found that the power output increases with the square of the B-field and can be limited by choking of the channel or interelectrode voltage breakdown which occurs at Hall fields greater than 50 volts/insulator. Peak power densities of greater than 100 MW/cu M were achieved.

Spatial correlations and probability density function of the phase difference in a developed speckle-field: numerical and natural experiments

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

Mysina, N Yu; Maksimova, L A; Ryabukho, V P

Investigated are statistical properties of the phase difference of oscillations in speckle-fields at two points in the far-field diffraction region, with different shapes of the scatterer aperture. Statistical and spatial nonuniformity of the probability density function of the field phase difference is established. Numerical experiments show that, for the speckle-fields with an oscillating alternating-sign transverse correlation function, a significant nonuniformity of the probability density function of the phase difference in the correlation region of the field complex amplitude, with the most probable values 0 and p, is observed. A natural statistical interference experiment using Young diagrams has confirmed the resultsmore » of numerical experiments. (laser applications and other topics in quantum electronics)« less

Meteorological support to the West German-United States Barium Ion Cloud Project.

NASA Technical Reports Server (NTRS)

Westfall, R. R.; Chamberlain, L. W.

1972-01-01

The objective of the Barium Ion Cloud Project was to study a barium ionized cloud released at an altitude of 5 earth radii. Accurate forecasting of weather conditions to prevail during the experiment period was critical to the project success. Good seeing conditions were required at all optical sites during the experiment. All meteorological support was the responsibility of the National Weather Service at Wallops Station, Virginia. Preliminary results confirm the scientists' theories of the magnetic fields and the existence of electric fields in the magnetosphere.

The Østerild Balconies Experiment

NASA Astrophysics Data System (ADS)

Karagali, I.; Mann, J.; Dellwik, E.; Simon, E.; Vasiljevic, N.; Larsen, G. C.

2017-12-01

The New European Wind Atlas (NEWA) is a joint effort of research agencies from eight European countries, co-funded under the ERANET Plus Program. The project is structured around two areas of work: development of dynamical downscaling methodologies and measurement campaigns to validate these methodologies, leading to the creation and publication of a European wind atlas in electronic form. One of the main objectives of the NEWA project is to carry out large-scale field experiments at a high spatial and temporal resolution, and provide a significant upgrade to the experimental databases currently available. The Østerild balconies experiment obtained high resolution measurements over an extended horizontal plane to quantify the effect of unevenly forested terrain on the mean wind field. The experiment was performed, between April 12 and August 12 2016, at the Østerild test station for large wind turbines, where DTU Wind Energy operates two 250 m tall meteorological towers, located in northern Denmark. During the first stage of the measurement campaign, a simple balcony-type structure was installed at a height of 50 m above local ground level (AGL), in each of the towers. A wind scanning lidar was placed on each of the balconies, thus the two instruments were simultaneously scanning an area thereby making it possible to reconstruct the wind field and quantify the wind speed variability in a horizontal plane. During the second phase of the experiment, the balconies were raised at the height of 200 m AGL, in order to verify and study the weaker imprint of surface heterogeneity on mean winds but also to study the large-scale spatial and temporal statistics of winds. The aim of the present study is to present the analyses of the measurements to obtain the horizontal wind field reconstruction and the preliminary results of the average wind flow patterns in relation to the terrain characteristics, during the period of available measurements.

How to grow transgenic Arabidopsis in the field.

PubMed

Jänkänpää, Hanna Johansson; Jansson, Stefan

2012-01-01

Arabidopsis is naturally adapted to habitats in which both biotic variables (e.g., light, wind, and humidity) and abiotic variables (e.g., competition, herbivory, and pathogen densities) strongly fluctuate. Hence, conditions in controlled growth chambers (in which Arabidopsis is typically grown for scientific experiments) differ substantially from those in natural environments. In order to mimic more closely natural conditions, we grow Arabidopsis outdoors under "semi-natural" field conditions. Performing experiments on transgenic Arabidopsis grown in the field that are sufficiently reliable for publication is challenging. In this chapter, we present some of our experiences based on 10 years of field experimentation, which may be of use to researchers seeking to perform field experiments using transgenic Arabidopsis.

Electrostatic ion instabilities in the presence of parallel currents and transverse electric fields

NASA Technical Reports Server (NTRS)

Ganguli, G.; Palmadesso, P. J.

1988-01-01

The electrostatic ion instabilities are studied for oblique propagation in the presence of magnetic field-aligned currents and transverse localized electric fields in a weakly collisional plasma. The presence of transverse electric fields result in mode excitation for magnetic field aligned current values that are otherwise stable. The electron collisions enhance the growth while ion collisions have a damping effect. These results are discussed in the context of observations of low frequency ion modes in the auroral ionosphere by radar and rocket experiments.

EXPERIMENTAL STUDIES OF INTERACTIONS BETWEEN TWO UNIONIDS, ELLIPTIO WACCAMAWENSIS AND LEPTODEA OCHRACEA: VARIATION IN NEGATIVE AND POSITIVE EFFECTS.

EPA Science Inventory

We conducted a field experiment in Lake Waccamaw, North Carolina, to elucidate the responses of two unionids (Elliptio waccamawensis and Leptodea ochracea) to varying population densities. Field enclosures at two depths maintained each species in low, mixed culture, and high den...

Navigating Community College Transfer in Science, Technical, Engineering, and Mathematics Fields

ERIC Educational Resources Information Center

Packard, Becky Wai-Ling; Gagnon, Janelle L.; Senas, Arleen J.

2012-01-01

Given financial barriers facing community college students today, and workforce projections in science, technical, engineering, and math (STEM) fields, the costs of unnecessary delays while navigating transfer pathways are high. In this phenomenological study, we analyzed the delay experiences of 172 students (65% female) navigating community…

Using Artificial Nests to Study Nest Predation in Birds

ERIC Educational Resources Information Center

Belthoff, James R.

2005-01-01

A simple and effective field exercise that demonstrates factors affecting predation on bird nests is described. With instructor guidance, students in high school biology or college-level biology, ecology, animal behavior, wildlife management or ornithology laboratory courses can collaborate to design field experiments related to nest depredation.

Day Jobs/Nightwork: Academic Staff Studying towards Higher Degrees

ERIC Educational Resources Information Center

Winberg, C.; Adams, A.; Esbach, J.; Groenewald, W.; Lakay, D.; Muzondo, I.; Randall, K.; Seane, G.; Siyepu, S.; Veeran, P.

2010-01-01

Universities of Technology (UTs) offer career-focused education in a wide variety of disciplines and fields. Traditionally, UTs recruited academic staff with relevant workplace experience, rather than academic qualifications. The result of this strategy was, while many lecturers possessed professional qualifications in their field, they did not…

Video Game-Based Methodology for Business Research

ERIC Educational Resources Information Center

Lawson, Larry L.; Lawson, Catherine L.

2010-01-01

Experimental research in business and economics has exploded in recent years in both laboratory and field settings. The generality of findings from field experiments is limited by the specificity of the experimental environment. Laboratory studies, on the other hand, are criticized for being devoid of the contextual cues that may indicate to…

Field Studies: Hands-on, Real-Science Research.

ERIC Educational Resources Information Center

Cunniff, Patricia A.; McMillen, Janet L.

1996-01-01

Describes an intensive three-week experience for 10th and 11th graders in a National Science Foundation Young Scholars Program. Two weeks of biology instruction precede one week of field research. The curriculum includes life histories of birds in the Chesapeake Bay area, reproductive ecology, aquatic ecology, entomology, and statistics. (DDR)

Field Trips as Valuable Learning Experiences in Geography Courses

ERIC Educational Resources Information Center

Krakowka, Amy Richmond

2012-01-01

Field trips have been acknowledged as valuable learning experiences in geography. This article uses Kolb's (1984) experiential learning model to discuss how students learn and how field trips can help enhance learning. Using Kolb's experiential learning theory as a guide in the design of field trips helps ensure that field trips contribute to…

Minimising the Residual Field and Field Gradient in a Magnetically Shielded Room for an nEDM experiment at Los Alamos National Laboratory

NASA Astrophysics Data System (ADS)

Amarasinghe, Chamindu; LANL nEDM Collaboration

2017-09-01

The LANL neutron Electric Dipole Moment (nEDM) experiment is an effort to set a sensitivity limit of 3.2 × 10-27 e cm on the electric dipole moment of the neutron, an order of magnitude smaller than the current upper limit. This measurement uses Ramsey's method of oscillating magnetic fields. The magnetic field and field gradient have to be low enough to avoid the smearing of the Ramsey fringes and to increase the neutron dephasing time respectively. The experiment is enclosed in a two layer Mu-metal magnetically shielded room (MSR) to null any external magnetic fields from the environment. The MSR is degaussed to sufficiently reduce its residual magnetic field and field gradient. The MSR is designed for residual fields as low as 30 nT. The experiment further requires a field gradient of 1 nT/m or smaller. Here we report on the degaussing procedure and the resulting improvement in the shielding prowess of the MSR. Funded by an NSF Grant.

A Communities of Practice Approach to Field Experiences in Teacher Education

ERIC Educational Resources Information Center

Warner, Connor Kirwan; Hallman, Heidi L.

2017-01-01

This article argues that prospective teachers who have the most productive experiences within pre-student teaching field experiences are those whose field sites allow them to become members of communities of practice, the conditions of which, according to Wenger (1998) include joint enterprise, mutual engagement, and shared repertoire. Employing…

Severe Weather Field Experience: An Undergraduate Field Course on Career Enhancement and Severe Convective Storms

ERIC Educational Resources Information Center

Godfrey, Christopher M.; Barrett, Bradford S.; Godfrey, Elaine S.

2011-01-01

Undergraduate students acquire a deeper understanding of scientific principles through first-hand experience. To enhance the learning environment for atmospheric science majors, the University of North Carolina at Asheville has developed the severe weather field experience. Participants travel to Tornado Alley in the Great Plains to forecast and…

Technology's Role in Field Experiences for Preservice Teacher Training

ERIC Educational Resources Information Center

Hixon, Emily; So, Hyo-Jeong

2009-01-01

The purpose of this paper is to provide a comprehensive review of how technology has been used to enhance or replace field experiences in preservice teacher preparation programs, and discuss the benefits and limitations of traditional and technology-enhanced/virtual field experience approaches. In this paper, three types of technology-enhanced…

Which Field Experiences Best Prepare Future School Leaders? An Analysis of Kentucky's Principal Preparation Program

ERIC Educational Resources Information Center

Dodson, Richard L.

2014-01-01

This paper examines the effectiveness of field experiences in preparing school principals for the exigencies of the job. Current school principals throughout Kentucky were surveyed regarding their perceptions of the utility and comparative effectiveness of field experiences in the principal preparation program (PPP) each attended. Surveys were…

Family Oriented Field Experience in Geography.

ERIC Educational Resources Information Center

Williams, Karen A.

A family-oriented geography field course about the southwestern United States was conducted in 1978 by a community college in Michigan (Delta College). Course activities took place in Colorado. The major purpose of the field experience was to offer learning experiences to family groups rather than to individual students. For purposes of the field…

Emerging Trends in Teacher Preparation: The Future of Field Experiences.

ERIC Educational Resources Information Center

Slick, Gloria Appelt, Ed.

This is the fourth in a series of four books presenting a variety of field experience program models and philosophies that drive the programs provided to preservice teachers during their undergraduate teacher preparation. This book focuses on critical issues facing teaching education in the future, in particular field experiences. Major themes…

The Integration of Multimedia and Field Experience.

ERIC Educational Resources Information Center

Dawson, George

A professor of science education at Florida State University shares his experiences with the growth of the field of environmental education and the problems inherent in trying to teach formal environmental education outdoors. Although field experience is best, it must be limited in most situations since logistics get in the way. Technology can…

STEMujeres: A case study of the life stories of first-generation Latina engineers and scientists

NASA Astrophysics Data System (ADS)

Vielma, Karina I.

Research points to the many obstacles that first-generation, Latina students face when attempting to enter fields in science, technology, engineering, and mathematics, STEM. This qualitative, case study examined the personal and educational experiences of first-generation Latina women who successfully navigated the STEM educational pipeline earning bachelor's, master's, and doctoral degrees in various fields of engineering. Three research questions guided the study: (1) How does a first-generation Latina engineer and scientist describe her life experiences as she became interested in STEM? (2) How does she describe her educational experiences as she navigated the educational pipeline in the physics, mathematics, and/or engineering field(s)? (3) How did she respond to challenges, obstacles and microaggressions, if any, while navigating the STEM educational pipeline? The study was designed using a combination of Critical Race Theory frameworks---Chicana feminist theory and racial microaggressions. Through a life history case study approach, the women shared their stories of success. With the participants' help, influential persons in their educational paths were identified and interviewed. Data were analyzed using crystallization and thematic results indicated that all women in this study identified their parents as planting the seed of interest through the introduction of mathematics. The women unknowingly prepared to enter the STEM fields by taking math and science coursework. They were guided to apply to STEM universities and academic programs by others who knew about their interest in math and science including teachers, counselors, and level-up peers---students close in age who were just a step more advanced in the educational pipeline. The women also drew from previous familial struggles to guide their perseverance and motivation toward educational degree completion. The lives of the women where complex and intersected with various forms of racism including gender, race, class, legality and power. In many instances, the women used their knowledge to help other STEMujeres advance.

Perspectives for the high field approach in fusion research and advances within the Ignitor Program

NASA Astrophysics Data System (ADS)

Coppi, B.; Airoldi, A.; Albanese, R.; Ambrosino, G.; Belforte, G.; Boggio-Sella, E.; Cardinali, A.; Cenacchi, G.; Conti, F.; Costa, E.; D'Amico, A.; Detragiache, P.; De Tommasi, G.; DeVellis, A.; Faelli, G.; Ferraris, P.; Frattolillo, A.; Giammanco, F.; Grasso, G.; Lazzaretti, M.; Mantovani, S.; Merriman, L.; Migliori, S.; Napoli, R.; Perona, A.; Pierattini, S.; Pironti, A.; Ramogida, G.; Rubinacci, G.; Sassi, M.; Sestero, A.; Spillantini, S.; Tavani, M.; Tumino, A.; Villone, F.; Zucchi, L.

2015-05-01

The Ignitor Program maintains the objective of approaching D-T ignition conditions by incorporating systematical advances made with relevant high field magnet technology and with experiments on high density well confined plasmas in the present machine design. An additional objective is that of charting the development of the high field line of experiments that goes from the Alcator machine to the ignitor device. The rationale for this class of experiments, aimed at producing poloidal fields with the highest possible values (compatible with proven safety factors of known plasma instabilities) is given. On the basis of the favourable properties of high density plasmas produced systematically by this line of machines, the envisioned future for the line, based on novel high field superconducting magnets, includes the possibility of investigating more advanced fusion burn conditions than those of the D-T plasmas for which Ignitor is designed. Considering that a detailed machine design has been carried out (Coppi et al 2013 Nucl. Fusion 53 104013), the advances made in different areas of the physics and technology that are relevant to the Ignitor project are reported. These are included within the following sections of the present paper: main components issues, assembly and welding procedures; robotics criteria; non-linear feedback control; simulations with three-dimensional structures and disruption studies; ICRH and dedicated diagnostics systems; anomalous transport processes including self-organization for fusion burning regimes and the zero-dimensional model; tridimensional structures of the thermonuclear instability and control provisions; superconducting components of the present machine; envisioned experiments with high field superconducting magnets.

How Does an Environmental Educator Address Student Engagement in a Meaningful Watershed Educational Experience (MWEE)?

NASA Astrophysics Data System (ADS)

Char, Chelia

Children represent the future and thus by providing them with effective environmental educational experiences, educators may be taking a critical step in preventing "the probable serious environmental problems in the future" (Gokhan, 2010, p. 56). The Meaningful Watershed Educational Experience (MWEE) is an excellent example of one such education program. MWEEs aim to educate and enhance the students' relationship with the Chesapeake Bay Watershed through an integration of classroom activities and fieldwork. As environmental educators and role models, field interpreters are a major component and significant influence on the local MWEE programs, however their perspective as to how they have impacted the programs has yet to be examined. Through a qualitative analysis and specific focus on the behavioral, emotional, and cognitive dimensions of student engagement, the researcher intended to address this void. The focus of the study was to examine how the local MWEE field interpreters understood and addressed student engagement in a field setting. This was measured via data collected from observations of and semi-structured, one-on-one interviews with each field interpreter involved with the local MWEE programs. Data analysis uncovered that field interpreters demonstrated a strong awareness of student engagement. Furthermore, they defined, recognized, and addressed student engagement within the constructs of the emotional, behavioral, and cognitive dimensions. Ultimately, the individual experiences of each MWEE field interpreter provides insight into the phenomenon, however further research is required to strengthen the awareness of how, if at all, their perspectives of student engagement directly impact student outcomes.

Shining light on modifications of gravity

NASA Astrophysics Data System (ADS)

Brax, Philippe; Burrage, Clare; Davis, Anne-Christine

2012-10-01

Many modifications of gravity introduce new scalar degrees of freedom, and in such theories matter fields typically couple to an effective metric that depends on both the true metric of spacetime and on the scalar field and its derivatives. Scalar field contributions to the effective metric can be classified as conformal and disformal. Disformal terms introduce gradient couplings between scalar fields and the energy momentum tensor of other matter fields, and cannot be constrained by fifth force experiments because the effects of these terms are trivial around static non-relativistic sources. The use of high-precision, low-energy photon experiments to search for conformally coupled scalar fields, called axion-like particles, is well known. In this article we show that these experiments are also constraining for disformal scalar field theories, and are particularly important because of the difficulty of constraining these couplings with other laboratory experiments.

Undoped GaAs bilayers for exciton condensation experiments

NASA Astrophysics Data System (ADS)

Lilly, M. P.

2005-03-01

Experimental progress in transport studies of exciton condensation of in electron and hole bilayers at high magnetic fields [1,2] has shown this novel physics can be observed. Fabrication of the bipolar electron-hole bilayers for zero field studies of exciton condensation still remains elusive. We describe a series of experiments on undoped GaAs/AlGaAs heterostructures with the motivation of making electron-hole bilayers. In these undoped devices, external electric fields induce carriers rather than the traditional doping techniques. Single layer electron (or hole) devices demonstrate a high mobility over a wide range of density. More recently, fully undoped bilayers have been made where the density in each layer is independently controlled with gates on the top and bottom of the bilayer. In this talk we present high field transport of undoped electron-electron bilayers, and describe recent progress towards extending the fabrication techniques to creating electron-hole bilayers for exciton condensation studies at zero magnetic field. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under contract DE-AC04-94AL85000. 1. M. Kellogg, J. P. Eisenstein, L. N. Pfeiffer, and K. W. West, Phys. Rev. Lett. 93 036801 (2004). 2. E. Tutoc, M. Shayegan, and D. A. Huse, Phys. Rev. Lett. 93, 036802 (2004).

Student-guided field based investigations of microplastic contamination in urban waterways as a tool to introduce environmental science students to scientific inquiry

NASA Astrophysics Data System (ADS)

Pondell, C.

2016-12-01

Microplastic pollution is becoming an increasing concern in oceanographic and environmental studies, and offers an opportunity to engage undergraduate students in environmental research using a highly relevant field of investigation. For instance, a majority of environmental science majors not only know about the Great Pacific Garbage Patch, but can also list off several statistics about its size and impact on marine life. Building on this enthusiasm for understanding the impact of microplastics on the environment, a laboratory class was designed to introduce environmental science majors to the rigors of scientific investigation using microplastic pollution in urban waterways as the focus of their laboratory experience. Over a seven-week period, students worked in small groups to design an experiment, collect samples in the field, analyze the samples in the lab, and present their findings in a university-wide forum. Their research questions focused on developing a better understanding of the transportation and fate of microplastics in the urban waterways of Washington, D.C. This presentation will explore the benefits and challenges associated with a student guided field study for environmental science undergraduates, and will describe results and student feedback from their urban microplastic field study.

The Rise of the Super Experiment

ERIC Educational Resources Information Center

Stamper, John C.; Lomas, Derek; Ching, Dixie; Ritter, Steve; Koedinger, Kenneth R.; Steinhart, Jonathan

2012-01-01

Traditional experimental paradigms have focused on executing experiments in a lab setting and eventually moving successful findings to larger experiments in the field. However, data from field experiments can also be used to inform new lab experiments. Now, with the advent of large student populations using internet-based learning software, online…

Crystallization of Calcium Carbonate in a Large Scale Field Study

NASA Astrophysics Data System (ADS)

Ueckert, Martina; Wismeth, Carina; Baumann, Thomas

2017-04-01

The long term efficiency of geothermal facilities and aquifer thermal energy storage in the carbonaceous Malm aquifer in the Bavarian Molasse Basin is seriously affected by precipitations of carbonates. This is mainly caused by pressure and temperature changes leading to oversaturation during production. Crystallization starts with polymorphic nuclei of calcium carbonate and is often described as diffusion-reaction controlled. Here, calcite crystallization is favoured by high concentration gradients while aragonite crystallization is occurring at high reaction rates. The factors affecting the crystallization processes have been described for simplified, well controlled laboratory experiments, the knowledge about the behaviour in more complex natural systems is still limited. The crystallization process of the polymorphic forms of calcium carbonate were investigated during a heat storage test at our test site in the eastern part of the Bavarian Molasse Basin. Complementary laboratory experiments in an autoclave were run. Both, field and laboratory experiments were conducted with carbonaceous tap water. Within the laboratory experiments additionally ultra pure water was used. To avoid precipitations of the tap water, a calculated amount of {CO_2} was added prior to heating the water from 45 - 110°C (laboratory) resp. 65 - 110°C (field). A total water volume of 0.5 L (laboratory) resp. 1 L (field) was immediately sampled and filtrated through 10 - 0.1

Matching time and spatial scales of rapid solidification: dynamic TEM experiments coupled to CALPHAD-informed phase-field simulations

NASA Astrophysics Data System (ADS)

Perron, Aurelien; Roehling, John D.; Turchi, Patrice E. A.; Fattebert, Jean-Luc; McKeown, Joseph T.

2018-01-01

A combination of dynamic transmission electron microscopy (DTEM) experiments and CALPHAD-informed phase-field simulations was used to study rapid solidification in Cu-Ni thin-film alloys. Experiments—conducted in the DTEM—consisted of in situ laser melting and determination of the solidification kinetics by monitoring the solid-liquid interface and the overall microstructure evolution (time-resolved measurements) during the solidification process. Modelling of the Cu-Ni alloy microstructure evolution was based on a phase-field model that included realistic Gibbs energies and diffusion coefficients from the CALPHAD framework (thermodynamic and mobility databases). DTEM and post mortem experiments highlighted the formation of microsegregation-free columnar grains with interface velocities varying from ˜0.1 to ˜0.6 m s-1. After an ‘incubation’ time, the velocity of the planar solid-liquid interface accelerated until solidification was complete. In addition, a decrease of the temperature gradient induced a decrease in the interface velocity. The modelling strategy permitted the simulation (in 1D and 2D) of the solidification process from the initially diffusion-controlled to the nearly partitionless regimes. Finally, results of DTEM experiments and phase-field simulations (grain morphology, solute distribution, and solid-liquid interface velocity) were consistent at similar time (μs) and spatial scales (μm).

Matching time and spatial scales of rapid solidification: Dynamic TEM experiments coupled to CALPHAD-informed phase-field simulations

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

Perron, Aurelien; Roehling, John D.; Turchi, Patrice E. A.

A combination of dynamic transmission electron microscopy (DTEM) experiments and CALPHAD-informed phase-field simulations was used to study rapid solidification in Cu–Ni thin-film alloys. Experiments—conducted in the DTEM—consisted of in situ laser melting and determination of the solidification kinetics by monitoring the solid–liquid interface and the overall microstructure evolution (time-resolved measurements) during the solidification process. Modelling of the Cu–Ni alloy microstructure evolution was based on a phase-field model that included realistic Gibbs energies and diffusion coefficients from the CALPHAD framework (thermodynamic and mobility databases). DTEM and post mortem experiments highlighted the formation of microsegregation-free columnar grains with interface velocities varying frommore » ~0.1 to ~0.6 m s –1. After an 'incubation' time, the velocity of the planar solid–liquid interface accelerated until solidification was complete. In addition, a decrease of the temperature gradient induced a decrease in the interface velocity. The modelling strategy permitted the simulation (in 1D and 2D) of the solidification process from the initially diffusion-controlled to the nearly partitionless regimes. Lastly, results of DTEM experiments and phase-field simulations (grain morphology, solute distribution, and solid–liquid interface velocity) were consistent at similar time (μs) and spatial scales (μm).« less

Matching time and spatial scales of rapid solidification: Dynamic TEM experiments coupled to CALPHAD-informed phase-field simulations

DOE PAGES

Perron, Aurelien; Roehling, John D.; Turchi, Patrice E. A.; ...

2017-12-05

A combination of dynamic transmission electron microscopy (DTEM) experiments and CALPHAD-informed phase-field simulations was used to study rapid solidification in Cu–Ni thin-film alloys. Experiments—conducted in the DTEM—consisted of in situ laser melting and determination of the solidification kinetics by monitoring the solid–liquid interface and the overall microstructure evolution (time-resolved measurements) during the solidification process. Modelling of the Cu–Ni alloy microstructure evolution was based on a phase-field model that included realistic Gibbs energies and diffusion coefficients from the CALPHAD framework (thermodynamic and mobility databases). DTEM and post mortem experiments highlighted the formation of microsegregation-free columnar grains with interface velocities varying frommore » ~0.1 to ~0.6 m s –1. After an 'incubation' time, the velocity of the planar solid–liquid interface accelerated until solidification was complete. In addition, a decrease of the temperature gradient induced a decrease in the interface velocity. The modelling strategy permitted the simulation (in 1D and 2D) of the solidification process from the initially diffusion-controlled to the nearly partitionless regimes. Lastly, results of DTEM experiments and phase-field simulations (grain morphology, solute distribution, and solid–liquid interface velocity) were consistent at similar time (μs) and spatial scales (μm).« less

Measurement of magnetostatic mode excitation and relaxation in permalloy films using scanning Kerr imaging

NASA Astrophysics Data System (ADS)

Tamaru, S.; Bain, J. A.; van de Veerdonk, R. J. M.; Crawford, T. M.; Covington, M.; Kryder, M. H.

2004-09-01

This work presents experimental results of magnetostatic mode excitation using scanning Kerr microscopy under continuous sinusoidal excitation in the microwave frequency range. This technique was applied to 100nm thick permalloy coupons excited in two different ways. In the first experiment, the uniform (Kittel) mode was excited at frequencies in 2.24-8.00GHz . The resonant condition was effectively described with the conventional Kittel mode equation. The LLG damping parameter α increased significantly with decreasing bias field. It was confirmed that this increase was caused by multidomain structure and ripple domains formed under weak bias fields, as suggested by other studies. In the second experiment, propagating magnetostatic mode surface waves were excited. They showed an exponential amplitude decay and a linear phase variation with distance from the drive field source, consistent with a decaying plane wave. The Damon-Eshbach (DE) model was extended to include a finite energy damping and used to analyze the results. It was found that the wave number and the decay constant were reasonably well described by the extended DE model. In contrast to the first experiment, no significant variation of α with frequency or bias field was seen in this second experiment, where spatial inhomogeneities in the magnetization are less significant.

End-on soft x ray imaging of Field-Reversed Configurations (FRCs) on the Field-Reversal-C (FRX-C)/Large Scale Modification (LSM) experiment

NASA Astrophysics Data System (ADS)

Taggart, D. P.; Gribble, R. J.; Bailey, A. D., III; Sugimoto, S.

Recently, a prototype soft x ray pinhole camera was fielded on FRX-C/LSM at Los Alamos and TRX at Spectra Technology. The soft x ray FRC images obtained using this camera stand out in high contrast to their surroundings. It was particularly useful for studying the FRC during and shortly after formation when, at certain operating conditions, flute-like structures at the edge and internal structures of the FRC were observed which other diagnostics could not resolve. Building on this early experience, a new soft x ray pinhole camera was installed on FRX-C/LSM, which permits more rapid data acquisition and briefer exposures. It will be used to continue studying FRC formation and to look for internal structure later in time which could be a signature of instability. The initial operation of this camera is summarized.

Astrophysically Relevant Dipole Studies at WiPAL

NASA Astrophysics Data System (ADS)

Endrizzi, Douglass; Forest, Cary; Wallace, John; WiPAL Team

2015-11-01

A novel terrella experiment is being developed to immerse a dipole magnetic field in the large, unmagnetized, and fully ionized background plasma of WiPAL (Wisconsin Plasma Astrophysics Lab). This allows for a series of related experiments motivated by astrophysical processes, including (1) inward transport of plasma into a magnetosphere with focus on development of Kelvin-Helmholtz instabilities from boundary shear flow; (2) helicity injection and simulation of solar eruptive events via electrical breakdown along dipole field lines; (3) interaction of Coronal Mass Ejection-like flows with a target magnetosphere and dependence on background plasma pressure; (4) production of a centrifugally driven wind to study how dipolar magnetic topology changes as closed field lines open. A prototype has been developed and preliminary results will be presented. An overview of the final design and construction progress will be given. This material is based upon work supported by the NSF Graduate Research Fellowship Program.