Setting up crowd science projects.

Science.gov (United States)

Scheliga, Kaja; Friesike, Sascha; Puschmann, Cornelius; Fecher, Benedikt

2016-11-29

Crowd science is scientific research that is conducted with the participation of volunteers who are not professional scientists. Thanks to the Internet and online platforms, project initiators can draw on a potentially large number of volunteers. This crowd can be involved to support data-rich or labour-intensive projects that would otherwise be unfeasible. So far, research on crowd science has mainly focused on analysing individual crowd science projects. In our research, we focus on the perspective of project initiators and explore how crowd science projects are set up. Based on multiple case study research, we discuss the objectives of crowd science projects and the strategies of their initiators for accessing volunteers. We also categorise the tasks allocated to volunteers and reflect on the issue of quality assurance as well as feedback mechanisms. With this article, we contribute to a better understanding of how crowd science projects are set up and how volunteers can contribute to science. We suggest that our findings are of practical relevance for initiators of crowd science projects, for science communication as well as for informed science policy making. © The Author(s) 2016.

NASA's NPOESS Preparatory Project Science Data Segment: A Framework for Measurement-based Earth Science Data Systems

Science.gov (United States)

Schwaller, Mathew R.; Schweiss, Robert J.

2007-01-01

The NPOESS Preparatory Project (NPP) Science Data Segment (SDS) provides a framework for the future of NASA s distributed Earth science data systems. The NPP SDS performs research and data product assessment while using a fully distributed architecture. The components of this architecture are organized around key environmental data disciplines: land, ocean, ozone, atmospheric sounding, and atmospheric composition. The SDS thus establishes a set of concepts and a working prototypes. This paper describes the framework used by the NPP Project as it enabled Measurement-Based Earth Science Data Systems for the assessment of NPP products.

Evaluation of genetic diversity in open pollinated guava by iPBS primers

International Nuclear Information System (INIS)

Mehmood, A.; Jaskani, M.J.; Ahmad, S.; Ahmad, R.

2013-01-01

DNA markers are important tools for assessing genetic diversity and relationships among species, cultivars and breeding materials. Many horticultural species are lacking genomic information. DNA markers that do not require prior knowledge of DNA sequences are therefore appealing for horticultural research. A retrotransposon-based DNA marker system, iPBS (inter primer binding sites) developed from conserved primer binding sites within retrotransposons, was used to study the genetic variation and relationships in ornamental guava. PCR from 6 iPBS primers (dominant markers) produced a total of 113 bands (52.38-100% polymorphic) ranging from 150 bp to 3000 bp, and the mean PIC value for each primer ranging from 0.1245 to 0.3698. Molecular information generated from both iPBS was separately scored in a matrix for phylogenetic dendrogram construction. The phylogenetic dendrogram based on iPBS markers reflected morphologic classifications of the accessions that were studied. The iPBS PCR-based genome fingerprinting technology in this study is low-cost and provides another effective alternative in differentiation of accessions in guava (Psidium guajava Linn.) and related species or genera. (author)

Review on PCL, PBS, and PCL/PBS blends containing carbon nanotubes

Directory of Open Access Journals (Sweden)

T. P. Gumede

2018-06-01

Full Text Available Biodegradable polymers received considerable attention due to their contribution in the reduction of environmental concerns and the realization that global petroleum resources are finite. The development of double crystalline biobased blends such as poly(ε-caprolactone (PCL and poly(butylene succinate (PBS are particularly interesting because each component has an influence on the crystallization behaviour of the other component, and thus influences the strength and mechanical properties of a polymer blend. The lack of miscibility between PCL and PBS constitutes a bottleneck, and efforts have been made to improve the miscibility through the inclusion of copolymers. Having realized that incorporating conductive nanofillers such as carbon nanotubes (CNTs, (especially when the CNTs are functionalized or used as a masterbatch i.e., polycarbonate/MWCNTs masterbatch, into biopolymer matrices, can enhance the thermal and mechanical properties, as well as electrical and thermal conductivity, a lot of research was aimed at the production of bionanocomposites. This review paper discusses the properties of PCL, PBS, their blends, and their CNTs containing nanocomposites.

Molecular characterization of Fagaceae species using inter-primer binding site (iPBS) markers.

Science.gov (United States)

Coutinho, João Paulo; Carvalho, Ana; Martín, Antonio; Lima-Brito, José

2018-04-01

Retrotransposons (RTNs) contribute for genome evolution, influencing its size and structure. We investigated the utility of the RTN-based markers inter-primer binding site (iPBS) for the molecular characterization of 25 Fagaceae species from genera Castanea, Fagus and Quercus. The assessment of genetic diversity, relationships and structure, as well as taxonomic classification of Fagaceae based on molecular data is important for definition of conservation, forestry management strategies and discrimination among natural hybrids and their parents since natural hybridization may increase with the climate changes. Here, iPBS primers designed by other authors were tested alone and combined. Some of them were discriminative, revealed polymorphism within and among taxa allowing the production of a total of 150 iPBS markers. In addition, several monomorphic iPBS markers were also amplified in each taxon. The UPGMA dendrogram based on the pooled iPBS data revealed 27% of genetic similarity among species. The individuals were clustered per genus and most of the oaks per infrageneric group corroborating the adopted taxonomy. Globally, the iPBS markers demonstrated suitability for DNA fingerprinting, determination of phylogenies and taxonomic discrimination in Fagaceae, and could constitute a useful and alternative tool for germplasm characterization, and for definition of conservation strategies and forestry management. Moreover, these markers would be useful for fingerprinting natural hybrids that share morphological similarities with their parents. Since iPBS markers could also enable insights about RTNs evolution, an eventual correlation among iPBS polymorphism, variability of RTN insertions and/or genome size in Fagaceae is discussed.

The perceptions of pre-service and in-service teachers regarding a project-based STEM approach to teaching science.

Science.gov (United States)

Siew, Nyet Moi; Amir, Nazir; Chong, Chin Lu

2015-01-01

Whilst much attention has focused on project-based approaches to teaching Science, Technology, Engineering and Mathematics (STEM) subjects, little has been reported on the views of South-East Asian science teachers on project-based STEM approaches. Such knowledge could provide relevant information for education training institutions on how to influence innovative teaching of STEM subjects in schools. This article reports on a study that investigated the perceptions of 25 pre-service and 21 in-service Malaysian science teachers in adopting an interdisciplinary project-based STEM approach to teaching science. The teachers undertook an eight hour workshop which exposed them to different science-based STEM projects suitable for presenting science content in the Malaysian high school science syllabus. Data on teachers' perceptions were captured through surveys, interviews, open-ended questions and classroom discussion before and at the end of the workshop. Study findings showed that STEM professional development workshops can provide insights into the support required for teachers to adopt innovative, effective, project-based STEM approaches to teaching science in their schools.

Novel Random PBS-Based Copolymers Containing Aliphatic Side Chains for Sustainable Flexible Food Packaging

Directory of Open Access Journals (Sweden)

Giulia Guidotti

2017-12-01

Full Text Available In the last decade, there has been an increased interest from the food packaging industry toward the development and application of biodegradable and biobased plastics, to contribute to the sustainable economy and to reduce the huge environmental problem afflicting the planet. In this framework, the present paper describes the synthesis of novel PBS (poly(butylene succinate-based random copolymers with different composition containing glycol sub-units characterized by alkyl pendant groups of different length. The prepared samples were subjected to molecular, thermal, diffractometric and mechanical characterization. The barrier performances to O2, CO2 and N2 gases were also evaluated, envisioning for these new materials an application in food packaging. The presence of the side alkyl groups did not alter the thermal stability, whereas it significantly reduced the sample crystallinity degree, making these materials more flexible. The barrier properties were found to be worse than PBS; however, some of them were comparable to, or even better than, those of Low Density Polyethylene (LDPE, widely employed for flexible food packaging. The entity of variations in the final properties due to copolymerization were more modest in the case of the co-unit with short side methyl groups, which, when included in the PBS crystal lattice, causes a more modest decrement of crystallinity degree.

DEVELOPMENT OF SCIENCE PROCESS SKILLS STUDENTS WITH PROJECT BASED LEARNING MODEL- BASED TRAINING IN LEARNING PHYSICS

Directory of Open Access Journals (Sweden)

Ratna Malawati

2016-06-01

Full Text Available This study aims to improve the physics Science Process Skills Students on cognitive and psychomotor aspects by using model based Project Based Learning training.The object of this study is the Project Based Learning model used in the learning process of Computationa Physics.The method used is classroom action research through two learning cycles, each cycle consisting of the stages of planning, implementation, observation and reflection. In the first cycle of treatment with their emphasis given training in the first phase up to third in the model Project Based Learning, while the second cycle is given additional treatment with emphasis discussion is collaboration in achieving the best results for each group of products. The results of data analysis showed increased ability to think Students on cognitive and Science Process Skills in the psychomotor.

Investigating Science Interest in a Game-Based Learning Project

Science.gov (United States)

Annetta, Leonard; Vallett, David; Fusarelli, Bonnie; Lamb, Richard; Cheng, Meng-Tzu; Holmes, Shawn; Folta, Elizabeth; Thurmond, Brandi

2014-01-01

The purpose of this study was to examine the effect Serious Educational Games (SEGs) had on student interest in science in a federally funded game-based learning project. It can be argued that today's students are more likely to engage in video games than they are to interact in live, face-to-face learning environments. With a keen eye on…

Effects of 3D Printing Project-based Learning on Preservice Elementary Teachers' Science Attitudes, Science Content Knowledge, and Anxiety About Teaching Science

Science.gov (United States)

Novak, Elena; Wisdom, Sonya

2018-05-01

3D printing technology is a powerful educational tool that can promote integrative STEM education by connecting engineering, technology, and applications of science concepts. Yet, research on the integration of 3D printing technology in formal educational contexts is extremely limited. This study engaged preservice elementary teachers (N = 42) in a 3D Printing Science Project that modeled a science experiment in the elementary classroom on why things float or sink using 3D printed boats. The goal was to explore how collaborative 3D printing inquiry-based learning experiences affected preservice teachers' science teaching self-efficacy beliefs, anxiety toward teaching science, interest in science, perceived competence in K-3 technology and engineering science standards, and science content knowledge. The 3D printing project intervention significantly decreased participants' science teaching anxiety and improved their science teaching efficacy, science interest, and perceived competence in K-3 technological and engineering design science standards. Moreover, an analysis of students' project reflections and boat designs provided an insight into their collaborative 3D modeling design experiences. The study makes a contribution to the scarce body of knowledge on how teacher preparation programs can utilize 3D printing technology as a means of preparing prospective teachers to implement the recently adopted engineering and technology standards in K-12 science education.

Monitoring system for OpenPBS environment

Energy Technology Data Exchange (ETDEWEB)

Kolosov, V. [ITEP, Moscow (Russian Federation)]. E-mail: victor.kolosov@itep.ru; Lublev, Y. [ITEP, Moscow (Russian Federation); Makarychev, S. [ITEP, Moscow (Russian Federation)

2004-11-21

The OpenPBS batch system is widely used in the HEP community. The Open PBS package has a set of tools to check the current status of the system. This information is useful, but it is not sufficient enough for resource accounting and planning. As a solution for this problem, we developed a monitoring system which parses the logfiles from OpenPBS and stores the information into a SQL database (PostgreSQL). This allows us to analyze the data in many different ways using SQL queries. The system was used in ITEP during the last two years for batch farm monitoring.

Modeling the PbS quantum dots complex dielectric function by adjusting the E-k diagram critical points of bulk PbS

Science.gov (United States)

Hechster, Elad; Sarusi, Gabby

2017-07-01

The complex dielectric function ɛ(E )=ɛR(E )+i ɛI(E ) of a semiconductor is a key parameter that dictates the material's optical and electrical properties. Surprisingly, the ɛ(E ) of Lead Sulfide (PbS) quantum dots (QDs) has not been widely studied. In the present work, we develop a new model that aims to simulate the ɛ(E ) of QDs. Our model is based on the fact that the quantum confinement in the nano regime affects all the electronic transitions throughout the entire Brillouin zone. Hence, as a first approximation, we attribute an equal contribution of energy, equivalent to the bandgap broadening, to each critical point (CP) in the E-k diagram. This is mathematically realized by adding these energy contributions to the central energy parameters of the Lorentz oscillator model. In order to validate our model, we used the CP parameters of bulk PbS to simulate the ɛ(E ) of PbS QDs. Next, we use Maxwell Relations to calculate the refractive index and the extinction coefficient of PbS QDs from ɛ(" separators="|E ). Our results were compared with those published in the previous literature and showed good agreement. Our findings open a new avenue that may enable the calculation of the ɛ(" separators="|E ) for nanoparticle systems.

Variables that impact the implementation of project-based learning in high school science

Science.gov (United States)

Cunningham, Kellie

Wagner and colleagues (2006) state the mediocrity of teaching and instructional leadership is the central problem that must be addressed if we are to improve student achievement. Educational reform efforts have been initiated to improve student performance and to hold teachers and school leaders accountable for student achievement (Wagner et al., 2006). Specifically, in the area of science, goals for improving student learning have led reformers to establish standards for what students should know and be able to do, as well as what instructional methods should be used. Key concepts and principles have been identified for student learning. Additionally, reformers recommend student-centered, inquiry-based practices that promote a deep understanding of how science is embedded in the everyday world. These new approaches to science education emphasize inquiry as an essential element for student learning (Schneider, Krajcik, Marx, & Soloway, 2002). Project-based learning (PBL) is an inquiry-based instructional approach that addresses these recommendations for science education reform. The objective of this research was to study the implementation of project-based learning (PBL) in an urban school undergoing reform efforts and identify the variables that positively or negatively impacted the PBL implementation process and its outcomes. This study responded to the need to change how science is taught by focusing on the implementation of project-based learning as an instructional approach to improve student achievement in science and identify the role of both school leaders and teachers in the creation of a school environment that supports project-based learning. A case study design using a mixed-method approach was used in this study. Data were collected through individual interviews with the school principal, science instructional coach, and PBL facilitator. A survey, classroom observations and interviews involving three high school science teachers teaching grades 9

Enhancement of Electron Transfer Efficiency in Solar Cells Based on PbS QD/N719 Dye Cosensitizers

Directory of Open Access Journals (Sweden)

Yanyan Gao

2012-01-01

Full Text Available Cosensitized solar cells (CSSCs have recently become an active subject in the field of sensitized solar cells (SSCs due to their increasing electronic utilization. However, because of the dye molecules, layer must be single, dye-SSCs cannot be co-sensitized with two different dyes to form two different molecules layer. But it is possible to be cosensitized with quantum dots (QDs and dyes. Here we designed novel photoanode architecture, namely, PbS QDs and N719 dyes are used as co-sensitizers of the TiO2 mesoporous film. The experimental result shows that PbS QDs/N719 dyes co-sensitized structure can make PbS QDs and N719 dyes mutual improvement. Taking the advantage of PbS not only achieved higher transfer efficiency of photo-excited electron, but also achieved obviously wider range and higher intensity of absorption. The PbS QDs which have been deposited on the TiO2 film was coated by N719 dyes, which can effectively prevent PbS QDs from corroding by I-/I3-electrolyte and light. As we expected, the solar energy-conversion efficiency which is showed by CSSCs fabricated following these photoanodes is relatively higher than the PbS QDs or N719 dyes, single-sensitized solar cells under the illumination of one sun.

Graphene and PbS quantum dot hybrid vertical phototransistor

Science.gov (United States)

Song, Xiaoxian; Zhang, Yating; Zhang, Haiting; Yu, Yu; Cao, Mingxuan; Che, Yongli; Dai, Haitao; Yang, Junbo; Ding, Xin; Yao, Jianquan

2017-04-01

A field-effect phototransistor based on a graphene and lead sulfide quantum dot (PbS QD) hybrid in which PbS QDs are embedded in a graphene matrix has been fabricated with a vertical architecture through a solution process. The n-type Si/SiO2 substrate (gate), Au/Ag nanowire transparent source electrode, active layer and Au drain electrode are vertically stacked in the device, which has a downscaled channel length of 250 nm. Photoinduced electrons in the PbS QDs leap into the conduction band and fill in the trap states, while the photoinduced holes left in the valence band transfer to the graphene and form the photocurrent under biases from which the photoconductive gain is evaluated. The graphene/QD-based vertical phototransistor shows a photoresponsivity of 2 × 103 A W-1, and specific detectivity up to 7 × 1012 Jones under 808 nm laser illumination with a light irradiance of 12 mW cm-2. The solution-processed vertical phototransistor provides a new facile method for optoelectronic device applications.

Examining student conceptions of the nature of science from two project-based classrooms

Science.gov (United States)

Moss, David M.

The purpose of this research was to develop descriptive accounts of precollege students' conceptions of the nature of science from two project-based classrooms, and track those conceptions over the course of an academic year. A model of the nature of science was developed and served as the criterion by which students' beliefs were evaluated. The model distinguishes between two major categories of science, the nature of the scientific enterprise and the nature of scientific knowledge. Five students were selected from each class and interviewed individually for 30-45 minutes each, six times over the year. Data from semi-structured, formal interviewing consisted of audio-recorded interviews which were transcribed verbatim. All passages were coded using codes which corresponded to the premises of the model of the nature of science. Passages in the transcripts were interpreted to develop a summary of the students' conceptions over the year. Qualitative methodologies, especially formal interviewing in conjunction with participant observation, were effective for uncovering students' conceptions of the nature of science, adding to the knowledge base in this field. The research design of the current study was a significant factor in explaining the inconsistencies seen between findings from this study and the literature. This study finds that participants at both classroom sites held fully formed conceptions of the nature of science for approximately 40 percent of the premises across the model. For two-thirds of the elements which comprise the premises, participants held full understandings. Participants held more complete understandings of the nature of scientific knowledge than the nature of the scientific enterprise. Most participants had difficulty distinguishing between science and non-science and held poor understandings of the role of questions in science. Students' beliefs generally remained unchanged over the year. When their conceptions did evolve, project-based

Environmental Science: 49 Science Fair Projects. Science Fair Projects Series.

Science.gov (United States)

Bonnet, Robert L.; Keen, G. Daniel

This book contains 49 science fair projects designed for 6th to 9th grade students. Projects are organized by the topics of soil, ecology (projects in habitat and life cycles), pests and controls (projects in weeds and insects), recycling (projects in resources and conservation), waste products (projects in decomposition), microscopic organisms,…

Digital Media for STEM Learning: Developing scientific practice skills in the K-12 STEM classroom with resources from WGBH and PBS LearningMedia

Science.gov (United States)

Foster, J.; Connolly, R.

2017-12-01

WGBH's "Bringing the Universe to America's Classrooms" project is a 5-year effort to design, produce and evaluate digital media tools and resources that support scientific practice skills in diverse K-12 learners. Resources leverage data and content from NASA and WGBH signature programs, like NOVA, into sound instructional experiences that provide K-12 STEM teachers with free, quality resources for teaching topics in the Earth and Space Sciences. Resources address the content and practices in the new K-12 Framework for Science Education and are aligned with the NGSS. Participants will learn about design strategies, findings from our evaluation efforts, and how to access free resources on PBS LearningMedia.

Tunable and switchable all-fiber comb filter using a PBS-based two-stage cascaded Mach-Zehnder interferometer

Science.gov (United States)

Luo, Zhi-Chao; Luo, Ai-Ping; Xu, Wen-Cheng

2011-08-01

We propose and demonstrate a novel tunable and switchable all-fiber comb filter by employing a polarization beam splitter (PBS)-based two-stage cascaded Mach-Zehnder (M-Z) interferometer. The proposed comb filter consists of a rotatable polarizer, a fiber PBS, a non-3-dB coupler and a 3-dB coupler. By simply adjusting the polarization state of the input light, the dual-function of channel spacing tunable and wavelength switchable (interleaving) operations can be efficiently obtained. The theoretical analysis is verified by the experimental results. A comb filter with both the channel spacing tunable from 0.18 nm to 0.36 nm and the wavelength switchable functions is experimentally demonstrated.

Facile synthesis of organically capped PbS nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Nejo, Ayorinde O.; Nejo, Adeola A.; Pullabhotla, Rajasekhar V.S.R. [Department of Chemistry, University of Zululand, Private Bag X1001, Kwadlangezwa (South Africa); Revaprasadu, Neerish, E-mail: nrevapra@pan.uzulu.ac.za [Department of Chemistry, University of Zululand, Private Bag X1001, Kwadlangezwa (South Africa)

2012-10-05

Highlights: Black-Right-Pointing-Pointer Hexadecylamine and tri-n-octylphosphine oxide capped PbS nanoparticles have been synthesized. Black-Right-Pointing-Pointer By varying the reaction conditions various morphologies were formed. Black-Right-Pointing-Pointer The formation of the anisotropic particles is due to different growth mechanisms. - Abstract: PbS nanocubes and nanorods were successfully synthesized through a facile route using hexadecylamine (HDA) and tri-n-octylphosphine oxide (TOPO) as surfactants. The structure and morphology of the as-prepared PbS nanocrystals were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution TEM. The morphology of the PbS was influenced by the variation in lead source and organic surfactant. Particles in the shape of spheres, perfect cubes and rods were obtained by variation in reaction conditions. A possible growth mechanism to explain the formation of these PbS nanocubes and nanorods is also discussed.

Enhancement of the photovoltaic performance in P3HT: PbS hybrid solar cells using small size PbS quantum dots

Energy Technology Data Exchange (ETDEWEB)

Firdaus, Yuliar; Van der Auweraer, Mark, E-mail: mark.vanderauweraer@chem.kuleuven.be [Laboratory of Photochemistry and Spectroscopy, Division of Molecular Imaging and Photonics, Chemistry Department, KULeuven, Celestijnenlaan 200F, 2404, B-3001 Leuven (Belgium); Vandenplas, Erwin; Gehlhaar, Robert; Cheyns, David [Imec vzw, Kapeldreef 75, B-3001 Leuven (Belgium); Justo, Yolanda; Hens, Zeger [Physical Chemistry Laboratory, Ghent University, Krijgslaan 281-S3, 9000 Gent (Belgium)

2014-09-07

Different approaches of surface modification of the quantum dots (QDs), namely, solution-phase (octylamine, octanethiol) and post-deposition (acetic acid, 1,4-benzenedithiol) ligand exchange were used in the fabrication of hybrid bulk heterojunction solar cell containing poly (3-hexylthiophene) (P3HT) and small (2.4 nm) PbS QDs. We show that replacing oleic acid by shorter chain ligands improves the figures of merit of the solar cells. This can possibly be attributed to a combination of a reduced thickness of the barrier for electron transfer and an optimized phase separation. The best results were obtained for post-deposition ligand exchange by 1,4-benzenedithiol, which improves the power conversion efficiency of solar cells based on a bulk heterojunction of lead sulfide (PbS) QDs and P3HT up to two orders of magnitude over previously reported hybrid cells based on a bulk heterojunction of P3HT:PbS QDs, where the QDs are capped by acetic acid ligands. The optimal performance was obtained for solar cells with 69 wt. % PbS QDs. Besides the ligand effects, the improvement was attributed to the formation of an energetically favorable bulk heterojunction with P3HT, when small size (2.4 nm) PbS QDs were used. Dark current density-voltage (J-V) measurements carried out on the device provided insight into the working mechanism: the comparison between the dark J-V characteristics of the bench mark system P3HT:PCBM and the P3HT:PbS blends allows us to conclude that a larger leakage current and a more efficient recombination are the major factors responsible for the larger losses in the hybrid system.

Enhancement of the photovoltaic performance in P3HT: PbS hybrid solar cells using small size PbS quantum dots

International Nuclear Information System (INIS)

Firdaus, Yuliar; Van der Auweraer, Mark; Vandenplas, Erwin; Gehlhaar, Robert; Cheyns, David; Justo, Yolanda; Hens, Zeger

2014-01-01

Different approaches of surface modification of the quantum dots (QDs), namely, solution-phase (octylamine, octanethiol) and post-deposition (acetic acid, 1,4-benzenedithiol) ligand exchange were used in the fabrication of hybrid bulk heterojunction solar cell containing poly (3-hexylthiophene) (P3HT) and small (2.4 nm) PbS QDs. We show that replacing oleic acid by shorter chain ligands improves the figures of merit of the solar cells. This can possibly be attributed to a combination of a reduced thickness of the barrier for electron transfer and an optimized phase separation. The best results were obtained for post-deposition ligand exchange by 1,4-benzenedithiol, which improves the power conversion efficiency of solar cells based on a bulk heterojunction of lead sulfide (PbS) QDs and P3HT up to two orders of magnitude over previously reported hybrid cells based on a bulk heterojunction of P3HT:PbS QDs, where the QDs are capped by acetic acid ligands. The optimal performance was obtained for solar cells with 69 wt. % PbS QDs. Besides the ligand effects, the improvement was attributed to the formation of an energetically favorable bulk heterojunction with P3HT, when small size (2.4 nm) PbS QDs were used. Dark current density-voltage (J-V) measurements carried out on the device provided insight into the working mechanism: the comparison between the dark J-V characteristics of the bench mark system P3HT:PCBM and the P3HT:PbS blends allows us to conclude that a larger leakage current and a more efficient recombination are the major factors responsible for the larger losses in the hybrid system

Portsmouth Atmospheric Science School (PASS) Project

Science.gov (United States)

Coleman, Clarence D.; Hathaway, Roger (Technical Monitor)

2002-01-01

The Portsmouth Atmospheric Science School Project (PASS) Project was granted a one-year no cost extension for 2001-2002. In year three of the project, objectives and strategies were modified based on the previous year-end evaluation. The recommendations were incorporated and the program was replicated within most of the remaining elementary schools in Portsmouth, Virginia and continued in the four middle schools. The Portsmouth Atmospheric Science School Project is a partnership, which includes Norfolk State University, Cooperating Hampton Roads Organizations for Minorities in Engineering (CHROME), NASA Langley Research Center, and the City of Portsmouth, Virginia Public Schools. The project seeks to strengthen the knowledge of Portsmouth Public Schools students in the field of atmospheric sciences and enhance teacher awareness of hands on activities in the atmospheric sciences. The project specifically seeks to: 1) increase the interest and participation of elementary and middle school students in science and mathematics; 2) strengthen existing science programs; and 3) facilitate greater achievement in core subjects, which are necessary for math, science, and technical careers. Emphasis was placed on providing training activities, materials and resources for elementary students (grades 3 - 5) and middle school students (grades 6 - 8), and teachers through a CHROME club structure. The first year of the project focused on introducing elementary students to concepts and activities in atmospheric science. Year two of the project built on the first year's activities and utilizes advanced topics and activities appropriate for middle school students. During the third year of the project, in addition to the approaches used in years one and two, emphasis was placed on activities that enhanced the Virginia Standards of Learning (SOL).

PBS in the service of ecology

International Nuclear Information System (INIS)

Stiegel, J.

1999-01-01

In this paper the activities of PBS Banska Bystrica, Ltd., in the service ecology are presented. PBS is fundamentally oriented toward repairs to and maintenance of original products of Prvni brnenska strojirna, including spare parts, as well as modernization and ecologization of heat-energy operations using low-emission combustion equipment, cogeneration units for steam-gas processes and high efficient technological process control systems. In connection with company's profile the prospectus expressed with a sum of 80 million Slovak crowns in orders accepted for 1998 was exceed by 15 million Slovak crowns and despite a bad situation on the Slovak financial market the company is functioning in the first year of its activity without credits. In the perspective by 2000 PBS plans to obtain 200 million Slovak crowns worth orders

The effects of topic choice in project-based instruction on undergraduate physical science students' interest, ownership, and motivation

Science.gov (United States)

Milner-Bolotin, Marina

2001-07-01

Motivating nonscience majors in science and mathematics studies became one of the most interesting and important challenges in contemporary science and mathematics education. Therefore, designing and studying a learning environment, which enhances students' motivation, is an important task. This experimental study sought to explore the implications of student autonomy in topic choice in a project-based Physical Science Course for nonscience majors' on students' motivational orientation. It also suggested and tested a model explaining motivational outcomes of project-based learning environment through increased student ownership of science projects. A project, How Things Work, was designed and implemented in this study. The focus of the project was application of physical science concepts learned in the classroom to everyday life situations. Participants of the study (N = 59) were students enrolled in three selected sections of a Physical Science Course, designed to fulfill science requirements for nonscience majors. These sections were taught by the same instructor over a period of an entire 16-week semester at a large public research university. The study focused on four main variables: student autonomy in choosing a project topic, their motivational orientation, student ownership of the project, and the interest in the project topic. Achievement Goal Orientation theory became the theoretical framework for the study. Student motivational orientation, defined as mastery or performance goal orientation, was measured by an Achievement Goal Orientation Questionnaire. Student ownership was measured using an original instrument, Ownership Measurement Questionnaire, designed and tested by the researchers. Repeated measures yoked design, ANOVA, ANCOVA, and multivariate regression analysis were implemented in the study. Qualitative analysis was used to complement and verify quantitative results. It has been found that student autonomy in the project choice did not make a

Science teachers' meaning-making when involved in a school-based professional development project

DEFF Research Database (Denmark)

Nielsen, Birgitte Lund

2012-01-01

A group of teachers’ meaning-making when they are collaboratively analyzing artifacts from practice in local science classrooms in a school-based professional development (PD) project is examined through repeated interviews and represented as meaning-making maps. The interpretation of the teachers......’ meaningmaking includes both their reference to outcomes from the project and their expressed ideas about teaching and learning of science. All four teachers refer to experiences from experimenting in their classrooms and interpret the collected artifacts in relation to students’ learning. Furthermore, they all...... felt encouraged to continue collaboration around science. During the interviews, the teachers emphasize various elements apparently connected to concrete challenges they each experience in their professional work. Implications in relation to the design of PD are discussed....

Science teachers' meaning-making when involved in a school-based professional development project

DEFF Research Database (Denmark)

Nielsen, Birgitte Lund

2012-01-01

A group of teachers' meaning-making when they are collaboratively analyzing artifacts from practice in local science classrooms in a school-based professional development (PD) project is examined through repeated interviews and represented as meaning-makig maps. The interpretation of the teachers......' meaning-making includes both their reference to outcomes from the project and their expressed ideas about teaching and learning of science. All four teachers refer to experiences from experimenting in their classrooms and interpret the collected artifacts in relation to students' learning. Furthermore......, they all felt encouraged to continue collaboration around science. During the interviews, the teachers emphasize various elements apparently connected to concrete challenges they each experience in their professional work. Implications in relation to the design of PD are discussed....

Earth System Science Project

Science.gov (United States)

Rutherford, Sandra; Coffman, Margaret

2004-01-01

For several decades, science teachers have used bottles for classroom projects designed to teach students about biology. Bottle projects do not have to just focus on biology, however. These projects can also be used to engage students in Earth science topics. This article describes the Earth System Science Project, which was adapted and developed…

Structural characterization of chemically deposited PbS thin films

International Nuclear Information System (INIS)

Fernandez-Lima, F.A.; Gonzalez-Alfaro, Y.; Larramendi, E.M.; Fonseca Filho, H.D.; Maia da Costa, M.E.H.; Freire, F.L.; Prioli, R.; Avillez, R.R. de; Silveira, E.F. da; Calzadilla, O.; Melo, O. de; Pedrero, E.; Hernandez, E.

2007-01-01

Polycrystalline thin films of lead sulfide (PbS) grown using substrate colloidal coating chemical bath depositions were characterized by RBS, XPS, AFM and GIXRD techniques. The films were grown on glass substrates previously coated with PbS colloidal particles in a polyvinyl alcohol solution. The PbS films obtained with the inclusion of the polymer showed non-oxygen-containing organic contamination. All samples maintained the Pb:S 1:1 stoichiometry throughout the film. The amount of effective nucleation centers and the mean grain size have being controlled by the substrate colloidal coating. The analysis of the polycrystalline PbS films showed that a preferable (1 0 0) lattice plane orientation parallel to the substrate surface can be obtained using a substrate colloidal coating chemical bath deposition, and the orientation increases when a layer of colloid is initially dried on the substrate

Science Song Project: Integration of Science, Technology and Music to Learn Science and Process Skills

Directory of Open Access Journals (Sweden)

Jiyoon Yoon

2017-07-01

Full Text Available It has been critical to find a way for teachers to motivate their young children to learn science and improve science achievement. Since music has been used as a tool for educating young students, this study introduces the science song project to teacher candidates that contains science facts, concepts, laws and theories, and combines them with music for motivating their young children to learn science and improve science achievement. The purpose of the study is to determine the effect of the science song project on teacher candidates’ understanding of science processing skills and their attitudes toward science. The participants were 45 science teacher candidates who were enrolled in an EC-6 (Early Childhood through Grade 6 program in the teacher certification program at a racially diverse Texas public research university. To collect data, this study used two instruments: pre-and post-self efficacy tests before and after the science teacher candidates experienced the science song project and final reflective essay at the end of the semester. The results show that while developing their songs, the participating teacher candidates experienced a process for science practice, understood science concepts and facts, and positively improved attitudes toward science. This study suggests that the science song project is a science instruction offering rich experiences of process-based learning and positive attitudes toward science.

Post secondary project-based learning in science, technology, engineering and mathematics

OpenAIRE

Ralph, Rachel A.

2016-01-01

Project-based learning (PjBL - to distinguish from problem-based learning - PBL) has become a recurrent practice in K-12 classroom environments. As PjBL has become prominent in K-12 classrooms, it has also surfaced in post-secondary institutions.  The purpose of this paper is to examine the research that has studied a variety of science, technology, engineering and mathematic subjects using PjBL in post-secondary classrooms. Eleven articles (including qualitative, quantitative and mixed metho...

Field effect transistors and phototransistors based upon p-type solution-processed PbS nanowires

Science.gov (United States)

Giraud, Paul; Hou, Bo; Pak, Sangyeon; Inn Sohn, Jung; Morris, Stephen; Cha, SeungNam; Kim, Jong Min

2018-02-01

We demonstrate the fabrication of solution processed highly crystalline p-type PbS nanowires via the oriented attachment of nanoparticles. The analysis of single nanowire field effect transistor (FET) devices revealed a hole conduction behaviour with average mobilities greater than 30 cm2 V-1 s-1, which is an order of magnitude higher than that reported to date for p-type PbS colloidal nanowires. We have investigated the response of the FETs to near-infrared light excitation and show herein that the nanowires exhibited gate-dependent photo-conductivities, enabling us to tune the device performances. The responsivity was found to be greater than 104 A W-1 together with a detectivity of 1013 Jones, which benefits from a photogating effect occurring at negative gate voltages. These encouraging detection parameters are accompanied by relatively short switching times of 15 ms at positive gate voltages, resulting from a combination of the standard photoconduction and the high crystallinity of the nanowires. Collectively, these results indicate that solution-processed PbS nanowires are promising nanomaterials for infrared photodetectors as well as p-type nanowire FETs.

Na-A4 zeolites as host of PbS nanoparticles

International Nuclear Information System (INIS)

Flores A, M.; Perez S, R.; Aceves T, R.; Arizpe C, H.; Sotelo L, M.; Ramirez B, R.

2006-01-01

In this work we report the optical and structural properties of composite materials based on the semiconductor PbS enclosed in type A zeolite. The composite materials were obtained by chemical reaction in several steps of the zeolite in alkaline aqueous solutions containing Pb 2+ and S 2- ions successively. Three samples were prepared at temperatures of 40, 50 and 60 C during the chemical reaction with S 2- ions. The obtained materials were studied by x-ray diffraction, scanning and transmission electron microscopy, diffuse reflectance spectroscopy and photoluminescence. The experimental results show the formation of spherical-shaped PbS particles with nano metric size and cubic crystalline structure embedded in the zeolite matrix. The absorption spectra of the samples display a well defined absorption band at about 300 nm due to the PbS nanoparticles in the zeolite matrix. In addition, an absorption peak appears in the absorption spectra at about 400 nm assigned to exciton transitions. (Author)

Science in Schools Project

Science.gov (United States)

Waugh, Mike

As part of a program to increase learning and engagement in science classes 124 Victorian schools are trialing a best practice teaching model. The Science in Schools Research Project is a DEET funded project under the Science in Schools Strategy, developed in response to recent research and policy decisions at national and state levels through which literacy, numeracy and science have been identified as key priorities for learning. This major science research project aims to identify, develop and trial best practice in Science teaching and learning. The Department will then be able to provide clear advice to Victoria's schools that can be adopted and sustained to: * enhance teaching and learning of Science * enhance student learning outcomes in Science at all year levels * increase student access to, and participation in Science learning from Prep through to Year 10, and hence in the VCE as well. The nature of the SiS program will be detailed with specific reference to the innovative programs in solar model cars, robotics and environmental science developed at Forest Hill College in response to this project.

Enhancing Teacher and Student Engagement and Understanding of Marine Science Through Classroom Citizen Science Projects

Science.gov (United States)

Goodale, T. A.

2016-02-01

Overview This paper presentation shares findings from a granted funded project that sought to expand teacher content knowledge and pedagogy within the fields of marine science and coastal resource management through the implementation of classroom citizen science projects. A secondary goal was to increase middle and high school student interest and participation in marine science and natural resources research. Background A local science & engineering fair has seen a rapid decline in secondary student participants in the past four years. Research has demonstrated that when students are a part of a system of knowledge production (citizen science) they become much more aware, involved and conscious of scientific concepts compared to traditional school laboratory and nature of science activities. This project's primary objectives were to: (a) enhance teacher content expertise in marine science, (b) enrich teacher professional learning, (c) support citizen science classroom projects and inspire student activism and marine science engagement. Methods Project goals were addressed through classroom and meaningful outdoor educational experiences that put content knowledge into field based practices. Teachers learned to apply thier expanded content knowlege through classroom citizen science projects that focus on marine resource conservation issues such as fisheries management, water quality, turtle nesting and biodiversity of coastal ecosystems. These projects would eventually become potential topics of citizen science research topics for their students to pursue. Upon completion of their professional development, participants were urged to establish student Marine Science clubs with the goal of mentoring student submissions into the local science fair. Supplemental awards were possible for the students of project participants. Findings Based on project measures participants significantly increased their knowledge and awareness of presented material marine science and

Initiative to introduce a performance-based standards (PBS) approach for heavy vehicle design and operations in South Africa

CSIR Research Space (South Africa)

Nordengen, Paul A

2008-05-01

Full Text Available The introduction of PBS for heavy vehicles in South Africa was first identified in the National Overload Control Strategy as a potential concession of a proposed Self-regulation initiative. In August 2004 a PBS committee was established...

Fabrication of PbS quantum dots and their applications in solar cells based on ZnO nanorod arrays

Science.gov (United States)

Kumar, Dinesh; Chaudhary, Sujeet; Pandya, Dinesh K.

2018-05-01

An efficient, inexpensive and large area scalable approach based on sol-gel technique is presented to fabricate quantum dots (QDs) of PbS. Size of the QDs is tuned by the varying the bath concentrations in the range of 50-200 mM. Transmission electron microscopy (TEM) studies confirm the growth of spherically shaped ˜5.6 nm QDs at 50 mM bath concentration. The optical bandgap of the QDs is found to be ˜0.9 eV and corresponds to the size obtained from TEM studies. ZnO/PbS solar cells are fabricated by sensitizing the ZnO nanorods with PbS QDs. The fabricated solar cells demonstrate the highest open circuit voltage ˜200 mV and short circuit current density ˜0.81 µA/cm2.

A novel electrochemical preparation of PbS nanoparticles

International Nuclear Information System (INIS)

Yang Yujun

2006-01-01

A simple one-step anodic sonoelectrochemical method to synthesize PbS nanoparticles has been developed. With the lead foil as the sacrificing anode, Pb(II) was anodically dissolved from the lead electrode into the aqueous solution of sodium sulfide, supporting electrolyte (potassium nitrate) and capping agent (PVA) at a constant potential, and then the produced Pb(II) reacted with the sulfide anion to form PbS nanoparticles under ultrasonic irradiation. The effects of the applied potential, capping agent and ultrasound in the formation of PbS nanoparticles are discussed, and the results suggest that the anodic sonoelectrochemical method may be a general and convenient way to prepare metal sulfide nanoparticles

WFIRST Project Science Activities

Science.gov (United States)

Gehrels, Neil

2012-01-01

The WFIRST Project is a joint effort between GSFC and JPL. The project scientists and engineers are working with the community Science Definition Team to define the requirements and initial design of the mission. The objective is to design an observatory that meets the WFIRST science goals of the Astr02010 Decadal Survey for minimum cost. This talk will be a report of recent project activities including requirements flowdown, detector array development, science simulations, mission costing and science outreach. Details of the interim mission design relevant to scientific capabilities will be presented.

The Use of Mobile Technologies in Project-Based Science: A Case Study

Science.gov (United States)

Avraamidou, Lucy

2013-01-01

The main aim of this study was to examine how a group of elementary students perceived their engagement in a project-based science intervention investigating the water quality of a local lake. The students collaborated with a scientist to conduct various experiments and used handheld computers to collect and analyze data in order to examine the…

Self-assembled colloidal PbS quantum dots on GaAs substrates

International Nuclear Information System (INIS)

Lue, Wei; Yamada, Fumihiko; Kamiya, Itaru

2010-01-01

We report the fabrication and analysis of self-assembled monolayer and bilayer films of colloidal PbS quantum dots (QDs) on GaAs (001) substrates. 1,6-hexanedithiol is used as link molecule between QDs and GaAs substrates. Atomic force microscopy (AFM) and photoluminescence (PL) measurements confirm the formation of PbS QD film on GaAs. For the monolayer PbS QD film, the temperature-dependent PL shows a feature typical of close-packed film. For the bilayer PbS QD film fabricated from two different mean-sized PbS QDs, we find that the stacking sequence of QDs with different size affects the quantum yield and emission wavelength of the film.

Solvent Engineering for High-Performance PbS Quantum Dots Solar Cells

Directory of Open Access Journals (Sweden)

Rongfang Wu

2017-07-01

Full Text Available PbS colloidal quantum dots (CQDs solar cells have already demonstrated very impressive advances in recent years due to the development of many different techniques to tailor the interface morphology and compactness in PbS CQDs thin film. Here, n-hexane, n-octane, n-heptane, isooctane and toluene or their hybrids are for the first time introduced as solvent for comparison of the dispersion of PbS CQDs. PbS CQDs solar cells with the configuration of PbS/TiO2 heterojunction are then fabricated by using different CQDs solution under ambient conditions. The performances of the PbS CQDs solar cells are found to be tuned by changing solvent and its content in the PbS CQDs solution. The best device could show a power conversion efficiency (PCE of 7.64% under AM 1.5 G illumination at 100 mW cm−2 in a n-octane/isooctane (95%/5% v/v hybrid solvent scheme, which shows a ~15% improvement compared to the control devices. These results offer important insight into the solvent engineering of high-performance PbS CQDs solar cells.

Project management of life-science research projects: project characteristics, challenges and training needs.

Science.gov (United States)

Beukers, Margot W

2011-02-01

Thirty-four project managers of life-science research projects were interviewed to investigate the characteristics of their projects, the challenges they faced and their training requirements. A set of ten discriminating parameters were identified based on four project categories: contract research, development, discovery and call-based projects--projects set up to address research questions defined in a call for proposals. The major challenges these project managers are faced with relate to project members, leadership without authority and a lack of commitment from the respective organization. Two-thirds of the project managers indicated that they would be interested in receiving additional training, mostly on people-oriented, soft skills. The training programs that are currently on offer, however, do not meet their needs. Copyright © 2010 Elsevier Ltd. All rights reserved.

A simple route for making surfactant free lead sulfide (PbS) quantum dots

Energy Technology Data Exchange (ETDEWEB)

Alam, Firoz; Kumar, Neetesh; Dutta, Viresh, E-mail: vdutta@ces.iitd.ac.in

2015-05-15

Highlights: • Surfactant free PbS NCs were successfully synthesised using CoSP technique. • The technique eliminates the requirements of washing to remove the ligands. • Grinding using mortar and pestle creates well separated PbS QDs. • Surfactant free PbS NCs are stable and do not show any degradation with time. - Abstract: An efficient, cost effective and less time consuming method suitable for mass production of surfactant free quantum dots (QDs) of lead sulfide (PbS) is reported. PbS nanocrystals (NCs) are first synthesised by continuous spray pyrolysis (CoSP) technique and de-agglomeration into PbS quantum dots (QDs) is achieved by vigorous mechanical grinding using mortar and pestle. Lead acetate and thiourea were used as the precursor materials for preparation of surfactant free PbS NCs. The broadening in XRD peaks of ground NCs as compared to as synthesized PbS NCs clearly indicated the reduction in particle size to be QDs of PbS. The TEM images also showed that ground PbS NCs were nearly spherical in shape having an average diameter in the range of 4–6 nm. The shift in optical gap from 0.41 eV to 1.47 eV supported the QD formation.

Global Warning: Project-Based Science Inspired by the Intergovernmental Panel on Climate Change

Science.gov (United States)

Colaianne, Blake

2015-01-01

Misconceptions about climate change are common, which suggests a need to effectively address the subject in the classroom. This article describes a project-based science activity in which students report on the physical basis, adaptations, and mitigation of this global problem, adapting the framework of the United Nations' Intergovernmental Panel…

The Use of Wikis in a Science Inquiry-Based Project in a Primary School

Science.gov (United States)

Lau, Wilfred W. F.; Lui, Vicky; Chu, Samuel K. W.

2017-01-01

This study explored the use of wikis in a science inquiry-based project conducted with Primary 6 students (aged 11-12). It used an online wiki-based platform called PBworks and addressed the following research questions: (1) What are students' attitudes toward learning with wikis? (2) What are students' interactions in online group collaboration…

Project-Based Learning as a Vehicle for Teaching Science at the University Level

Science.gov (United States)

Courtney, A. R.; Wade, P.

2012-12-01

In a typical science course learning is teacher directed. Students are presented with knowledge and concepts via textbooks and lecture and then given the opportunity to apply them. Project-based learning (PBL) creates a context and reason to learn information and concepts. In PBL, learning is student directed and teacher facilitated. Students take ownership of their learning by finding, evaluating and synthesizing information from a variety of resources and via interaction between each other. In PBL, the project is central rather than peripheral to the curriculum. It is not just an activity that provides examples, additional practice or applications of the course content, but rather, the vehicle through which major concepts are discovered. The PBL process requires students to do revision and reflection encouraging them to think about what and how they are learning. PBL projects also allow students to develop important life-work skills such as collaboration, communication and critical thinking within the discipline. We have employed PBL in both Liberal Arts courses for non-science majors and upper division courses for science students. Three examples will be discussed. The first will be the production of video documentaries in a non-science major course; the second, a student generated electronic textbook in a 300-level energy course for science students; and lastly, a student designed analysis project in a chemistry major capstone laboratory course. The product in each of these examples was used to deliver knowledge to others in the class as well as members of the public providing motivation for students to do high-quality work. In our examples, student documentaries are publicly screened as part of a university-wide Academic Excellence Showcase; the student generated electronic textbook is available for public use on the internet; and the results of the student designed analysis were communicated to the real-world clients via letters and reports. We will discuss

Monitoring results of PBS vehicles in South Africa in terms of productivity, safety and road wear performance

CSIR Research Space (South Africa)

Nordengen, Paul A

2013-07-01

Full Text Available As part of a Performance-Based Standards (PBS) research programme for heavy vehicles in South Africa, a need was identified to design, manufacture and operate a number of PBS or Smart Truck demonstration vehicles in order to gain practical...

Band-structure tailoring and surface passivation for highly efficient near-infrared responsive PbS quantum dot photovoltaics

Science.gov (United States)

Zhou, Ru; Niu, Haihong; Ji, Fengwei; Wan, Lei; Mao, Xiaoli; Guo, Huier; Xu, Jinzhang; Cao, Guozhong

2016-11-01

PbS is a promising light harvester for near-infrared (NIR) responsive quantum dot (QD) photovoltaics due to its narrow bulk band gap (0.41 eV) and large exciton Bohr radius (18 nm). However, the relatively low conduction band (CB) and high-density surface defects of PbS as two major drawbacks for its use in solar cells severely hamper the photovoltaic performance enhancement. In this work, a modified solution-based successive ionic layer adsorption and reaction (SILAR) utilizing mixed cationic precursors of Pb2+ and Cd2+ is explored, and such a scheme offers two benefits, band-structure tailoring and surface passivation. In-situ deposited CdS suppresses the excessive growth of PbS in the mesopores, thereby facilitating the favorable electron injection from PbS to TiO2 in view of the up-shifted CB level of QDs; the intimate interpenetration of two sulfides with each other leads to superior passivation of trap state defects on PbS, which suppresses the interfacial charge recombination. With the construction of photovoltaics based on such a hybrid (Pb,Cd)S/CdS configuration, impressive power conversion efficiency up to 4.08% has been reached, outperforming that of the conventional PbS/CdS pattern (2.95%). This work highlights the great importance of band-structure tailoring and surface passivation for constructing highly efficient PbS QD photovoltaics.

The meaning-making of science teachers participating in a school-based PD project

DEFF Research Database (Denmark)

Nielsen, Birgitte Lund

The meaning-making of four science teachers involved in collaboratively analyzing video and other artifacts from practice in local science classrooms in a school-based professional development project is examined through repeated interviews and represented as meaning-making maps. The research aim...... is to examine how these collaborative inquiries make sense to the teachers: what they identify as outcomes, how they make use of inputs and support in their classrooms and in collegial interactions and how their ideas about teaching and learning of science might play a role. An adapted version...... learning of science in concrete situations. They refer to outcomes from sharing experiments with new tools and materials and refer to being encouraged to continue collaboration around science at the school. Beside this the teachers emphasize various outcomes apparently for each of them in areas where...

The meaning-making of science teachers participating in as school based PD project

DEFF Research Database (Denmark)

Nielsen, Birgitte Lund

The meaning-making of four science teachers involved in collaboratively analyzing video and other artifacts from practice in local science classrooms in a school-based professional development project is examined through repeated interviews and represented as meaning-making maps. The research aim...... is to examine how these collaborative inquiries make sense to the teachers: what they identify as outcomes, how they make use of inputs and support in their classrooms and in collegial interactions and how their ideas about teaching and learning of science might play a role. An adapted version...... learning of science in concrete situations. They refer to outcomes from sharing experiments with new tools and materials and refer to being encouraged to continue collaboration around science at the school. Beside this the teachers emphasize various outcomes apparently for each of them in areas where...

Application of Model Project Based Learning on Integrated Science in Water Pollution

Science.gov (United States)

Yamin, Y.; Permanasari, A.; Redjeki, S.; Sopandi, W.

2017-09-01

The function of this research was to analyze the influence model Project Based Learning (PjBl) on integrated science about the concept mastery for junior high school students. Method used for this research constitutes the quasi of experiment method. Population and sample for this research are the students junior high school in Bandung as many as two classes to be experiment and control class. The instrument that used for this research is the test concept mastery, assessment questionnaire of product and the questionnaire responses of the student about learning integrated science. Based on the result of this research get some data that with accomplishment the model of PjBl. Learning authority of integrated science can increase the concept mastery for junior high school students. The highest increase in the theme of pollution water is in the concept of mixtures and the separation method. The students give a positive response in learning of integrated science for the theme of pollution of the water used model PjBL with questionnaire of the opinion aspect in amount of 83.5%, the anxiety of the students in amount of 95.5%, the profit learning model of PjBL in amount of 96.25% and profit learning of integrated science in amount of 95.75%.

Colloidal PbS nanocrystals integrated to Si-based photonics for applications at telecom wavelengths

Science.gov (United States)

Humer, M.; Guider, R.; Jantsch, W.; Fromherz, T.

2013-05-01

In the last decade, Si based photonics has made major advances in terms of design, fabrication, and device implementation. But due to Silicon's indirect bandgap, it still remains a challenge to create efficient Si-based light emitting devices. In order to overcome this problem, an approach is to develop hybrid systems integrating light-emitting materials into Si. A promising class of materials for this purpose is the class of semiconducting nanocrystal quantum dots (NCs) that are synthesized by colloidal chemistry. As their absorption and emission wavelength depends on the dot size, which can easily be controlled during synthesis, they are extremely attractive as building blocks for nanophotonic applications. For applications in telecom wavelength, Lead chalcogenide colloidal NCs are optimum materials due to their unique optical, electronic and nonlinear properties. In this work, we experimentally demonstrate the integration of PbS nanocrystals into Si-based photonic structures like slot waveguides and ring resonators as optically pumped emitters for room temperature applications. In order to create such hybrid structures, the NCs were dissolved into polymer resists and drop cast on top of the device. Upon optical pumping, intense photoluminescence emission from the resonating modes is recorded at the output of the waveguide with transmission quality factors up to 14000. The polymer host material was investigated with respect to its ability to stabilize the NC's photoluminescence emission against degradation under ambient conditions. The waveguide-ring coupling efficiency was also investigated as function of the NCs concentrations blended into the polymer matrix. The integration of colloidal quantum dots into Silicon photonic structures as demonstrated in this work is a very versatile technique and thus opens a large range of applications utilizing the linear and nonlinear optical properties of PbS NCs at telecom wavelengths.

An Analysis of the Supports and Constraints for Scientific Discussion in High School Project-Based Science

Science.gov (United States)

Alozie, Nonye M.; Moje, Elizabeth Birr; Krajcik, Joseph S.

2010-01-01

One goal of project-based science is to promote the development of scientific discourse communities in classrooms. Holding rich high school scientific discussions is challenging, especially when the demands of content and norms of high school science pose challenges to their enactment. There is little research on how high school teachers enact…

Overcoming the Cut-Off Charge Transfer Bandgaps at the PbS Quantum Dot Interface

KAUST Repository

El-Ballouli, Ala'a O.

2015-11-17

Light harvesting from large size of semiconductor PbS quantum dots (QDs) with a bandgap of less than 1 eV is one of the greatest challenges precluding the development of PbS QD-based solar cells because the interfacial charge transfer (CT) from such QDs to the most commonly used electron acceptor materials is very inefficient, if it occurs at all. Thus, an alternative electron-accepting unit with a new driving force for CT is urgently needed to harvest the light from large-sized PbS QDs. Here, a cationic porphyrin is utilized as a new electron acceptor unit with unique features that bring the donor–acceptor components into close molecular proximity, allowing ultrafast and efficient electron transfer for QDs of all sizes, as inferred from the drastic photoluminescence quenching and the ultrafast formation of the porphyrin anionic species. The time-resolved results clearly demonstrate the possibility of modulating the electron transfer process between PbS QDs and porphyrin moieties not only by the size quantization effect but also by the interfacial electrostatic interaction between the positively charged porphyrin and the negatively charged QDs. This approach provides a new pathway for engineering QD-based solar cells that make the best use of the diverse photons making up the Sun\\'s broad irradiance spectrum.

Overcoming the Cut-Off Charge Transfer Bandgaps at the PbS Quantum Dot Interface

KAUST Repository

El-Ballouli, Ala'a O.; Alarousu, Erkki; Kirmani, Ahmad R.; Amassian, Aram; Bakr, Osman; Mohammed, Omar F.

2015-01-01

Light harvesting from large size of semiconductor PbS quantum dots (QDs) with a bandgap of less than 1 eV is one of the greatest challenges precluding the development of PbS QD-based solar cells because the interfacial charge transfer (CT) from such QDs to the most commonly used electron acceptor materials is very inefficient, if it occurs at all. Thus, an alternative electron-accepting unit with a new driving force for CT is urgently needed to harvest the light from large-sized PbS QDs. Here, a cationic porphyrin is utilized as a new electron acceptor unit with unique features that bring the donor–acceptor components into close molecular proximity, allowing ultrafast and efficient electron transfer for QDs of all sizes, as inferred from the drastic photoluminescence quenching and the ultrafast formation of the porphyrin anionic species. The time-resolved results clearly demonstrate the possibility of modulating the electron transfer process between PbS QDs and porphyrin moieties not only by the size quantization effect but also by the interfacial electrostatic interaction between the positively charged porphyrin and the negatively charged QDs. This approach provides a new pathway for engineering QD-based solar cells that make the best use of the diverse photons making up the Sun's broad irradiance spectrum.

Science Projects | Akron-Summit County Public Library

Science.gov (United States)

Hours & Locations Main Library Science & Technology Division Science Projects Science Projects Have fun with science experiments. Whether you need to do a project for a school science fair or you want to be a mad scientist, our Science Project Index and other resources can get you started. Find how

Co-sensitization of quantum dot sensitized solar cells composed of TiO2 nanocrystalline photoanode with CdS and PbS nanoparticles and effect of PbS on the performance of solar cell

Directory of Open Access Journals (Sweden)

Maziar Marandi

2017-09-01

Full Text Available In this research, CdS and PbS quantum dots were applied as the light sensitizers in TiO2 based nanostructured solar cells. The PbS quantum dots could absorb a wide range of the sunlight spectrum on earth due to their low bandgap energy. As a result, the cell sensitization is more effective by application of both CdS and PbS quantum dots sensitizers. The TiO2 nanocrystals were synthesized through a hydrothermal process and deposited on FTO glass substrates as the photoanode scaffold. Then PbS quantum dots were grown on the surface of this nanocrystalline layer by a successive ionic layer adsorption and reaction (SILAR method. The CdS quantum dots were over-grown in the next step through a similar deposition method. Finally this sensitized layer was applied as the photoelectrode of the corresponding quantum dot sensitized solar cells. The results demonstrated that the maximum efficiency was achieved for the cell with a photoanode made of co-sensitization through 2 and 6 cycles of PbS and CdS deposition, respectively. The photovoltaic parameters of this cell were measured as Jsc of 10.81 mA/cm2, Voc of 590 mv and energy conversion efficiency of 2.7+0.2%.

Analysis of an Interactive Technology Supported Problem-Based Learning STEM Project Using Selected Learning Sciences Interest Areas (SLSIA)

Science.gov (United States)

Kumar, David Devraj

2017-01-01

This paper reports an analysis of an interactive technology-supported, problem-based learning (PBL) project in science, technology, engineering and mathematics (STEM) from a Learning Sciences perspective using the Selected Learning Sciences Interest Areas (SLSIA). The SLSIA was adapted from the "What kinds of topics do ISLS [International…

Preparation of nanostructured PbS thin films as sensing element for NO{sub 2} gas

Energy Technology Data Exchange (ETDEWEB)

Kaci, S., E-mail: k_samira05@yahoo.fr [Centre de Recherche en Technologie des Semi-conducteurs pour l’Energétique (CRTSE) Division Couches Minces et Interfaces, 02 Bd Frantz Fanon, B.P. 140, 7 Merveilles, 16038 Algiers (Algeria); Keffous, A.; Hakoum, S. [Centre de Recherche en Technologie des Semi-conducteurs pour l’Energétique (CRTSE) Division Couches Minces et Interfaces, 02 Bd Frantz Fanon, B.P. 140, 7 Merveilles, 16038 Algiers (Algeria); Trari, M. [Université des Sciences et Technologies Houari Boumediene (USTHB), Laboratoire de Stockage et de Valorisation des Eneriges Renouvelables, Faculté de Chimie, BP 32, EL Alia, 16111 Bab Ezzouar, Algiers (Algeria); Mansri, O.; Menari, H. [Centre de Recherche en Technologie des Semi-conducteurs pour l’Energétique (CRTSE) Division Couches Minces et Interfaces, 02 Bd Frantz Fanon, B.P. 140, 7 Merveilles, 16038 Algiers (Algeria)

2014-06-01

In this work, we demonstrate that semiconducting films of A{sub IV}B{sub VI} compounds, in particular, of nanostructured lead sulfide (PbS) which prepared by chemical bath deposition (CBD), can be used as a sensing element for nitrogen dioxide (NO{sub 2}) gas. The CBD method is versatile, simple in implementation and gives homogeneous semiconductor structures. We have prepared PbS nanocrystalline thin film at different reaction baths and temperatures. In the course of deposition, variable amounts of additives, such as organic substances among them, were introduced into the baths. The energy dispersive analysis (EDX) confirms the chemical composition of PbS films. A current–voltage (I–V) characterization of Pd/nc-PbS/a-SiC:H pSi(100)/Al Schottky diode structures were studied in the presence of NO{sub 2} gas. The gas sensing behavior showed that the synthesized PbS nanocrystalline thin films were influenced by NO{sub 2} gas at room temperature. The results can be used for developing an experimental sensing element based on chemically deposited nanostructured PbS films which can be applicable in gas sensors.

Deposition and characteristics of PbS thin films by an in-situ solution chemical reaction process

Energy Technology Data Exchange (ETDEWEB)

Ji, Junna; Ji, Huiming; Wang, Jian; Zheng, Xuerong; Lai, Junyun; Liu, Weiyan; Li, Tongfei [School of Materials Science and Engineering, Key Laboratory for Advanced Ceramics and Machining Technology of Ministry of Education, Tianjin University, Tianjin 300072 (China); Ma, Yuanliang; Li, Haiqin; Zhao, Suqin [College of Physics and Electronic Information Engineering, Qinghai University for Nationalities, Xining 810007 (China); Jin, Zhengguo, E-mail: zhgjin@tju.edu.cn [School of Materials Science and Engineering, Key Laboratory for Advanced Ceramics and Machining Technology of Ministry of Education, Tianjin University, Tianjin 300072 (China)

2015-09-01

Preferential oriented and uniform PbS thin films were deposited by a room temperature in-situ solution chemical reaction process, in which the lead nitrate as precursor in a form of thin solid films from lead precursor solution was used to react with ammonium sulfide ethanol solution. Influence of 1-butanol addition in the lead precursor solution, Pb:S molar ratios in the separate cationic and anionic solutions, deposition cycle numbers and annealing treatment in Ar atmosphere on structure, morphology, chemical composition and optical absorption properties of the deposited PbS films were investigated based on X-ray diffraction, field emission scanning electron microscopy, energy dispersive spectrometer, atomic force microscopy, selected area electron diffraction, UV–vis, near infrared ray and fourier transform infrared spectroscopy measurements. The results showed that the deposited PbS thin films had a cubic structure and highly preferred orientation along with the plane (100). The deposition rate of single-layer was stable, about 30 nm in thickness per deposition cycle. - Highlights: • Time-efficiency synthetic method for the preparation of lead sulfide (PbS) films • Effect of 1-butanol addition into cationic precursor solution is discussed. • Growth rate of the PbS films is stable at about 30 nm per cycle.

Science communication in European projects

International Nuclear Information System (INIS)

Vachev, Boyko; Stamenov, Jordan

2009-01-01

Science communication in several resent successful projects of Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences (INRNE, BAS) from the 5th and 6th Framework Programmes of EC is presented: the joint INRNE, BAS project with JRC of EC (FP5 NUSES) and two subsequent Centre of Excellence projects (FP5 HIMONTONET and FP6 BEOBAL) are considered. Innovations and traditional forms development and application are discussed. An overview of presentation and communication of INRNE, BAS contribution to Bulgarian European Project is made. Good practices have been derived. Keywords: Science communication, European projects, Innovations

High School Students' Reasons for Their Science Dispositions: Community-Based Innovative Technology-Embedded Environmental Research Projects

Science.gov (United States)

Ebenezer, Jazlin; Kaya, Osman Nafiz; Kasab, Dimma

2018-05-01

The purpose of this investigation was to qualitatively describe high school students' reasons for their science dispositions (attitude, perception, and self-confidence) based on their long-term experience with innovative technology-embedded environmental research projects. Students in small groups conducted research projects in and out of school with the help of their teachers and community experts (scientists and engineers). During the 3-year period of this nationally funded project, a total of 135 students from five schools in a mid-west State participated in research activities. Of the 135 students, 53 students were individually interviewed to explore reasons for their science dispositions. Students' reasons for each disposition were grouped into categories, and corresponding frequency was converted to a percentage. The categories of reasons were not only attributed to the use of innovative technologies in environmental research but also the contexts and events that surrounded it. The reasons that influenced students' science dispositions positively were because engaging in environmental research projects with technology contributed to easing fear and difficulty, building a research team, disseminating findings, communicating with the community, researching with scientists, training by teachers, and acknowledging teachers' knowledge. These results advanced how and why students develop science dispositions in the positive direction, which are as follows: building science teacher capacity, developing a community of inquirers, and committing to improve pedagogical practices.

Facilitating Elementary Science Teachers' Implementation of Inquiry-Based Science Teaching

Science.gov (United States)

Qablan, Ahmad M.; DeBaz, Theodora

2015-01-01

Preservice science teachers generally feel that the implementation of inquiry-based science teaching is very difficult to manage. This research project aimed at facilitating the implementation of inquiry-based science teaching through the use of several classroom strategies. The evaluation of 15 classroom strategies from 80 preservice elementary…

Molecular diversity analysis of Tetradium ruticarpum (WuZhuYu) in China based on inter-primer binding site (iPBS) markers and inter-simple sequence repeat (ISSR) markers.

Science.gov (United States)

Xu, Jing-Yuan; Zhu, Yan; Yi, Ze; Wu, Gang; Xie, Guo-Yong; Qin, Min-Jian

2018-01-01

"Wu zhu yu", which is obtained from the dried unripe fruits of Tetradium ruticarpum (A. Jussieu) T. G. Hartley, has been used as a traditional Chinese medicine for treatment of headaches, abdominal colic, and hypertension for thousands of years. The present study was designed to assess the molecular genetic diversity among 25 collected accessions of T. ruticarpum (Wu zhu yu in Chinese) from different areas of China, based on inter-primer binding site (iPBS) markers and inter-simple sequence repeat (ISSR) markers. Thirteen ISSR primers generated 151 amplification bands, of which 130 were polymorphic. Out of 165 bands that were amplified using 10 iPBS primers, 152 were polymorphic. The iPBS markers displayed a higher proportion of polymorphic loci (PPL = 92.5%) than the ISSR markers (PPL = 84.9%). The results showed that T. ruticarpum possessed high loci polymorphism and genetic differentiation occurred in this plant. The combined data of iPBS and ISSR markers scored on 25 accessions produced five clusters that approximately matched the geographic distribution of the species. The results indicated that both iPBS and ISSR markers were reliable and effective tools for analyzing the genetic diversity in T. ruticarpum. Copyright © 2018 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

Nongeminate radiative recombination of free charges in cation-exchanged PbS quantum dot films

Energy Technology Data Exchange (ETDEWEB)

Marshall, Ashley R. [National Renewable Energy Laboratory, 15013 Denver West Pkwy., Golden, CO 80401 (United States); Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309 (United States); Beard, Matthew C.; Johnson, Justin C. [National Renewable Energy Laboratory, 15013 Denver West Pkwy., Golden, CO 80401 (United States)

2016-06-01

Highlights: • Photoluminescence and transient absorption are used to probe PbS QD films. • Cation-exchanged PbS QDs show room-temperature PL emission. • Bimolecular recombination is shown for the first time in coupled, PbS QD films. - Abstract: Using photoluminescence (PL) spectroscopy we explore the radiative recombination pathways in PbS quantum dots (QDs) synthesized by two methods. We compare conventionally synthesized PbS from a PbO precursor to PbS synthesized using cation-exchange from CdS QDs. We show that strongly coupled films of PbS QDs from the cation-exchange luminesce with significant efficiency at room temperature. This is in stark contrast to conventional PbS QDs, which have exceedingly weak room temperature emission. Moreover, the power dependence of the emission is quadratic, indicating bimolecular radiative recombination that is reasonably competitive with trap-assisted recombination, a feature previously unreported in coupled PbS QD films. We interpret these results in terms of a greatly reduced defect concentration for cation-exchanged QDs that mitigates the influence of trap-assisted recombination. Cation-exchanged QDs have recently been employed in highly efficient and air-stable lead chalcogenide QD devices, and the reduced number of trap states inferred here may lead to improved current collection and higher open circuit voltage.

Scientist-teacher collaboration: Integration of real data from a coastal wetland into a high school life science ecology-based research project

Science.gov (United States)

Hagan, Wendy L.

Project G.R.O.W. is an ecology-based research project developed for high school biology students. The curriculum was designed based on how students learn and awareness of the nature of science and scientific practices so that students would design and carry out scientific investigations using real data from a local coastal wetland. This was a scientist-teacher collaboration between a CSULB biologist and high school biology teacher. Prior to implementing the three-week research project, students had multiple opportunities to practice building requisite skills via 55 lessons focusing on the nature of science, scientific practices, technology, Common Core State Standards of reading, writing, listening and speaking, and Next Generation Science Standards. Project G.R.O.W. culminated with student generated research papers and oral presentations. Outcomes reveal students struggle with constructing explanations and the use of Excel to create meaningful graphs. They showed gains in data organization, analysis, teamwork and aspects of the nature of science.

iPBS: a universal method for DNA fingerprinting and retrotransposon isolation.

Science.gov (United States)

Kalendar, Ruslan; Antonius, Kristiina; Smýkal, Petr; Schulman, Alan H

2010-11-01

Molecular markers are essential in plant and animal breeding and biodiversity applications, in human forensics, and for map-based cloning of genes. The long terminal repeat (LTR) retrotransposons are well suited as molecular markers. As dispersed and ubiquitous transposable elements, their "copy and paste" life cycle of replicative transposition leads to new genome insertions without excision of the original element. Both the overall structure of retrotransposons and the domains responsible for the various phases of their replication are highly conserved in all eukaryotes. Nevertheless, up to a year has been required to develop a retrotransposon marker system in a new species, involving cloning and sequencing steps as well as the development of custom primers. Here, we describe a novel PCR-based method useful both as a marker system in its own right and for the rapid isolation of retrotransposon termini and full-length elements, making it ideal for "orphan crops" and other species with underdeveloped marker systems. The method, iPBS amplification, is based on the virtually universal presence of a tRNA complement as a reverse transcriptase primer binding site (PBS) in LTR retrotransposons. The method differs from earlier retrotransposon isolation methods because it is applicable not only to endogenous retroviruses and retroviruses, but also to both Gypsy and Copia LTR retrotransposons, as well as to non-autonomous LARD and TRIM elements, throughout the plant kingdom and to animals. Furthermore, the inter-PBS amplification technique as such has proved to be a powerful DNA fingerprinting technology without the need for prior sequence knowledge.

South African performance based standards (PBS) vehicle to transport steel pipes

CSIR Research Space (South Africa)

Dessein, T

2010-03-01

Full Text Available measures the vehicle?s rollover stability. Rearward Amplification (RA) ? Measures the degree to which the lateral accelerations experienced by trailing units are amplified in comparison to that of the towing unit in a high speed evasive single lane...-speed 90? turn high-speed travel along a 1.0km long straight road with uneven road surface a pulse-steer test HVTT11: A South African PBS Vehicle to Transport Pipes 10 a constant radius turn at slowly increasing speed an evasive lane change...

Study of the back recombination processes of PbS quantum dots sensitized solar cells

Science.gov (United States)

Badawi, Ali; Al-Hosiny, N.; Merazga, Amar; Albaradi, Ateyyah M.; Abdallah, S.; Talaat, H.

2016-12-01

In this study, the back recombination processes of PbS quantum dots sensitized solar cells (QDSSCs) has been investigated. PbS QDs were adsorbed onto titania electrodes to act the role of sensitizers using successive ionic layer adsorption and reaction (SILAR) technique. The energy band gaps of the synthesized PbS QDs/titania are ranged from 1.64 eV (corresponding to 756 nm) to 3.12 eV (397 nm) matching the whole visible solar spectrum. The hyperbolic band model (HBM) was used to calculate PbS QDs size and it ranges from 1.76 to 3.44 nm. The photovoltaic parameters (open circuit voltage Voc, short circuit current density Jsc, fill factor FF and efficiency η) of the assembled PbS QDs sensitized solar cells (QDSSCs) were determined under a solar illumination of 100 mW/cm2 (AM 1.5 conditions). The open circuit voltage-decay (OCVD) rates of the assembled PbS QDSSCs were measured. The time constant (τ) for PbS QDSSCs (4 SILAR cycles) shows one order of magnitude larger than that of PbS QDSSCs (8 SILAR cycles) as a result of a decreased electron-hole back recombination.

A Coastal Citizen Science Project - How to run an international Citizen Science Project?

Science.gov (United States)

Kruse, K.; Knickmeier, K.; Thiel, M.; Gatta, M.

2016-02-01

"Searching for plastic garbage" is an international Citizen Science project that aims to participate school students in the public discussion on the topic "plastic pollution in the ocean". For this, young people apply various research methods, evaluate their data, communicate and publish their results and investigate solutions solving this problem. The project will be carried out in Chile and Germany at the same time, which allows the participating students to share and compare their results and discuss their ideas with an international partner. This takes place on the website www.save-ocean.org. The project promotes intercultural and scientific skills of the students. They get insights into scientific research, get into another culture and experiences plastic pollution as an important global problem. Since May 2015, 450 pupils aged 10 to 15 years and 20 teachers in Germany and Chile have explored the plastic garbage on beaches. Where are the largest plastic garbage deposits? Which items of plastic are mostly found in Germany and Chile? Or where does this garbage comes from? These and other research questions are being answered by an international network between students, teachers and scientists. After completing the first Citizen Science pilot study successfully in summer 2015, the entire German and Chilean coast will be explored in spring 2016 by around 2500 participating school students. The project "Searching for plastic garbage" is the first international Citizen Science project that is a cooperation between the ocean:lab of Kiel Science Factory and the "Cientificos de la Basura", a project of the department of marine biology at University Catolica del Norte in Coquimbo, Chile. The project is supported by the Cluster of Excellence "The Future Ocean", the Leibniz Institute for Science Education and Mathematics (IPN), the Ministry of School and Professional Education of Land Schleswig-Holstein and the University Catolica del Norte in Coquimbo, Chile

Holistic Approach to Secondary Earth Science Teacher Professional Development: the Triad of Project-based Instruction, Earth Science Content, and GIS Technology

Science.gov (United States)

Rubino-Hare, L.; Sample, J. C.; Fredrickson, K.; Claesgens, J.; Bloom, N.; Henderson-Dahms, C.; Manone, M.

2011-12-01

We have provided two years of professional development for secondary and middle school teachers with a focus on project-based instruction (PBI) using GIS. The EYE-POD project (funded by NSF-ITEST) involved pairs of teachers from Arizona and the surrounding region in two-week institutes during Summer, 2010, and an advanced institute in Summer, 2011. The NAz-POD project (funded by Arizona Department of Education and administered by Science Foundation Arizona) provided similar PD experiences, but the institutes occurred during weekends in the academic year. The institutes were led by a team with expertise in Earth science content, professional development and pedagogy, and GIS. The teachers developed learning modules using the project based learning instructional model. Pedagogy, content, and GIS skills were combined throughout the professional development activities. Academic year follow up by NAU personnel included classroom observations and technical support. For assessing student work we provided a rubric, but learned that teachers were not prepared to assess GIS products in order to determine the level of student understanding. In year two of the project we incorporated strategies for assessment of student products into the professional development. Teacher-participants and their students completed several pre- and post- assessments. Teacher assessments included a geospatial performance assessment, classroom observations, and content tests. Student data collection included attitude and efficacy questionnaires, content tests, and authentic assessments including products using GIS. Content tests were the same for teachers and students and included spatial reasoning, data analysis, and Earth science content. Data was also collected on teacher perception of professional development delivery and self-reported confidence in teaching with PBI and geospatial technology. Student assessments show that improvement occurred in all areas on the content test. Possible factors

Reflexivity in performative science shop projects

OpenAIRE

Beunen, R.; Duineveld, M.; During, R.; Straver, G.H.M.B.; Aalvanger, A.

2012-01-01

Science shop research projects offer possibilities for universities to engage with communities. Many science shop projects directly or indirectly intend to empower certain marginalised groups or interests within a decision-making process. In this article we argue that it is important to reflect on the role and position the researchers have in these projects. We present three science shop projects to illustrate some of the dilemmas that may arise in relation to citizen empowerment, democracy, ...

SU-F-T-185: Study of the Robustness of a Proton Arc Technique Based On PBS Beams

Energy Technology Data Exchange (ETDEWEB)

Wang, Z [Reading Hospital, West Reading, PA (United States); Zheng, Y [Procure Proton Therapy Center, Oklahoma City, OK (United States)

2016-06-15

Purpose: One potential technique to realize proton arc is through using PBS beams from many directions to form overlaid Bragg peak (OBP) spots and placing these OBP spots throughout the target volume to achieve desired dose distribution. In this study, we analyzed the robustness of this proton arc technique. Methods: We used a cylindrical water phantom of 20 cm in radius in our robustness analysis. To study the range uncertainty effect, we changed the density of the phantom by ±3%. To study the setup uncertainty effect, we shifted the phantom by 3 & 5 mm. We also combined the range and setup uncertainties (3mm/±3%). For each test plan, we performed dose calculation for the nominal and 6 disturbed scenarios. Two test plans were used, one with single OBP spot and the other consisting of 121 OBP spots covering a 10×10cm{sup 2} area. We compared the dose profiles between the nominal and disturbed scenarios to estimate the impact of the uncertainties. Dose calculation was performed with Gate/GEANT based Monte Carlo software in cloud computing environment. Results: For each of the 7 scenarios, we simulated 100k & 10M events for plans consisting of single OBP spot and 121 OBP spots respectively. For single OBP spot, the setup uncertainty had minimum impact on the spot’s dose profile while range uncertainty had significant impact on the dose profile. For plan consisting of 121 OBP spots, similar effect was observed but the extent of disturbance was much less compared to single OBP spot. Conclusion: For PBS arc technique, range uncertainty has significantly more impact than setup uncertainty. Although single OBP spot can be severely disturbed by the range uncertainty, the overall effect is much less when a large number of OBP spots are used. Robustness optimization for PBS arc technique should consider range uncertainty with priority.

SU-F-T-185: Study of the Robustness of a Proton Arc Technique Based On PBS Beams

International Nuclear Information System (INIS)

Wang, Z; Zheng, Y

2016-01-01

Purpose: One potential technique to realize proton arc is through using PBS beams from many directions to form overlaid Bragg peak (OBP) spots and placing these OBP spots throughout the target volume to achieve desired dose distribution. In this study, we analyzed the robustness of this proton arc technique. Methods: We used a cylindrical water phantom of 20 cm in radius in our robustness analysis. To study the range uncertainty effect, we changed the density of the phantom by ±3%. To study the setup uncertainty effect, we shifted the phantom by 3 & 5 mm. We also combined the range and setup uncertainties (3mm/±3%). For each test plan, we performed dose calculation for the nominal and 6 disturbed scenarios. Two test plans were used, one with single OBP spot and the other consisting of 121 OBP spots covering a 10×10cm"2 area. We compared the dose profiles between the nominal and disturbed scenarios to estimate the impact of the uncertainties. Dose calculation was performed with Gate/GEANT based Monte Carlo software in cloud computing environment. Results: For each of the 7 scenarios, we simulated 100k & 10M events for plans consisting of single OBP spot and 121 OBP spots respectively. For single OBP spot, the setup uncertainty had minimum impact on the spot’s dose profile while range uncertainty had significant impact on the dose profile. For plan consisting of 121 OBP spots, similar effect was observed but the extent of disturbance was much less compared to single OBP spot. Conclusion: For PBS arc technique, range uncertainty has significantly more impact than setup uncertainty. Although single OBP spot can be severely disturbed by the range uncertainty, the overall effect is much less when a large number of OBP spots are used. Robustness optimization for PBS arc technique should consider range uncertainty with priority.

Oleic acid capped PbS nanoparticles: Synthesis, characterization and tribological properties

International Nuclear Information System (INIS)

Chen Shuang; Liu Weimin

2006-01-01

Oleic acid (OA) capped PbS nanoparticles were chemically synthesized and characterized by means of Fourier transform-infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray electron diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The triboligical properties of the capped PbS nanoparticles as additive in liquid paraffin was investigated using a four-ball machine. The lubricating mechanisms were discussed along with the analyses results of XPS and scanning electron microscope (SEM). Results show that OA-capped PbS nanoparticles, with an average diameter of about 8 nm, are able to prevent water adsorption, oxidation and are capable of being dispersed stably in organic solvents or mineral oil. OA-capped PbS nanoparticles as an additive in liquid paraffin perform good antiwear and friction-reduction properties owing to the formation of a boundary film

Inorganic-ligand exchanging time effect in PbS quantum dot solar cell

International Nuclear Information System (INIS)

Kim, Byung-Sung; Hong, John; Hou, Bo; Cho, Yuljae; Sohn, Jung Inn; Cha, SeungNam; Kim, Jong Min

2016-01-01

We investigate time-dependent inorganic ligand exchanging effect and photovoltaic performance of lead sulfide (PbS) nanocrystal films. With optimal processing time, volume shrinkage induced by residual oleic acid of the PbS colloidal quantum dot (CQD) was minimized and a crack-free film was obtained with improved flatness. Furthermore, sufficient surface passivation significantly increased the packing density by replacing from long oleic acid to a short iodide molecule. It thus facilities exciton dissociation via enhanced charge carrier transport in PbS CQD films, resulting in the improved power conversion efficiency from 3.39% to 6.62%. We also found that excess iodine ions on the PbS surface rather hinder high photovoltaic performance of the CQD solar cell.

Inorganic-ligand exchanging time effect in PbS quantum dot solar cell

Energy Technology Data Exchange (ETDEWEB)

Kim, Byung-Sung; Hong, John; Hou, Bo; Cho, Yuljae; Sohn, Jung Inn, E-mail: junginn.sohn@eng.ox.ac.uk, E-mail: seungnam.cha@eng.ox.ac.uk; Cha, SeungNam, E-mail: junginn.sohn@eng.ox.ac.uk, E-mail: seungnam.cha@eng.ox.ac.uk [Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ (United Kingdom); Kim, Jong Min [Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA (United Kingdom)

2016-08-08

We investigate time-dependent inorganic ligand exchanging effect and photovoltaic performance of lead sulfide (PbS) nanocrystal films. With optimal processing time, volume shrinkage induced by residual oleic acid of the PbS colloidal quantum dot (CQD) was minimized and a crack-free film was obtained with improved flatness. Furthermore, sufficient surface passivation significantly increased the packing density by replacing from long oleic acid to a short iodide molecule. It thus facilities exciton dissociation via enhanced charge carrier transport in PbS CQD films, resulting in the improved power conversion efficiency from 3.39% to 6.62%. We also found that excess iodine ions on the PbS surface rather hinder high photovoltaic performance of the CQD solar cell.

Unknown Aspects of Self-Assembly of PbS Microscale Superstructures

Science.gov (United States)

Querejeta-Fernández, Ana; Hernández-Garrido, Juan C.; Yang, Hengxi; Zhou, Yunlong; Varela, Aurea; Parras, Marina; Calvino-Gámez, José J.; González-Calbet, Jose M.; Green, Peter F.; Kotov, Nicholas A.

2012-01-01

A lot of interesting and sophisticated examples of nanoparticle (NP) self-assembly (SA) are known. From both fundamental and technological standpoints this field requires advancements in three principle directions: a) understanding the mechanism and driving forces of three-dimensional (3D) SA with both nano- and micro-levels of organization; b) understanding of disassembly/deconstruction processes; and c) finding synthetic methods of assembly into continuous superstructures without insulating barriers. From this perspective, we investigated the formation of well-known star-like PbS superstructures and found a number of previously unknown or overlooked aspects that can advance the knowledge of NP self-assembly in these three directions. The primary one is that the formation of large seemingly monocrystalline PbS superstructures with multiple levels of octahedral symmetry can be explained only by SA of small octahedral NPs. We found five distinct periods in the formation PbS hyperbranched stars: 1) nucleation of early PbS NPs with an average diameter of 31 nm; 2) assembly into 100–500 nm octahedral mesocrystals; 3) assembly into 1000–2500 nm hyperbranched stars; 4) assembly and ionic recrystallization into six-arm rods accompanied by disappearance of fine nanoscale structure; 5) deconstruction into rods and cubooctahedral NPs. The switches in assembly patterns between the periods occur due to variable dominance of pattern–determining forces that include vander Waals and electrostatic (charge-charge, dipole-dipole, and polarization) interactions. The superstructure deconstruction is triggered by chemical changes in the deep eutectic solvent (DES) used as the media. PbS superstructures can be excellent models for fundamental studies of nanoscale organization and SA manufacturing of (opto)electronics and energy harvesting devices which require organization of PbS components at multiple scales. PMID:22515512

Designing heavy vehicles to be safer and more productive using PBS

CSIR Research Space (South Africa)

Kienhöfer, FW

2013-07-01

Full Text Available condition that the proposed vehicle’s safety is demonstrated either through physical testing or simulations. Such a PBS approach is currently being evaluated in South Africa. This paper summarises the productivity and safety increases of three PBS...

Synthesis of star-shaped lead sulfide (PbS) nanomaterials and theirs gas-sensing properties

Energy Technology Data Exchange (ETDEWEB)

Song, Chengwen; Sun, Menghan; Yin, Yanyan; Xiao, Jingkun; Dong, Wei; Li, Chen; Zhang, Li, E-mail: chengwensong@dlmu.edu.cn [College of Environmental Science and Engineering, Dalian Maritime University, Dalian(China)

2016-11-15

Star-shaped PbS nanomaterials are synthesized by a hydrothermal method. Morphology and structure of the PbS nanomaterials are analyzed by SEM, HRTEM and XRD. Gas-sensing properties of the as-prepared PbS sensor are also systematically investigated. The results show star-shaped PbS nanostructure consists of four symmetric arms in the same plane and demonstrate good crystallinity. With the increase of ethanol concentration, the sensitivity of the PbS sensor significantly increases and demonstrates an almost linear relationship at the optimal operating temperature of 400 deg C. Moreover, the fast response-recovery towards ethanol is also observed, which indicates its great potential on ethanol detection. (author)

Synthesis of star-shaped lead sulfide (PbS) nanomaterials and theirs gas-sensing properties

International Nuclear Information System (INIS)

Song, Chengwen; Sun, Menghan; Yin, Yanyan; Xiao, Jingkun; Dong, Wei; Li, Chen; Zhang, Li

2016-01-01

Star-shaped PbS nanomaterials are synthesized by a hydrothermal method. Morphology and structure of the PbS nanomaterials are analyzed by SEM, HRTEM and XRD. Gas-sensing properties of the as-prepared PbS sensor are also systematically investigated. The results show star-shaped PbS nanostructure consists of four symmetric arms in the same plane and demonstrate good crystallinity. With the increase of ethanol concentration, the sensitivity of the PbS sensor significantly increases and demonstrates an almost linear relationship at the optimal operating temperature of 400 deg C. Moreover, the fast response-recovery towards ethanol is also observed, which indicates its great potential on ethanol detection. (author)

Optical properties of PbS thin films

Energy Technology Data Exchange (ETDEWEB)

Akhmedov, O. R., E-mail: orucahmedov@mail.ru; Guseinaliyev, M. G. [National Academy of Azerbaijan, Nakhichevan Branch (Azerbaijan); Abdullaev, N. A.; Abdullaev, N. M.; Babaev, S. S.; Kasumov, N. A. [National Academy of Sciences of Azerbaijan, Abdullaev Institute of Physics (Azerbaijan)

2016-01-15

The complex dielectric function of PbS thin films is studied by spectroscopic ellipsometry in the spectral range from 0.74 to 6.45 eV at a temperature of 293 K. The critical energies are determined to be E{sub 1} = 3.53 eV and E{sub 2} = 4.57 eV. For both energy regions, the best fit is attained at the critical point 2D (m = 0). In addition, the Raman spectra and the optical-absorption spectra of PbS thin films are studied. From the dependence of the quantity (αhν){sup 2} on the photon energy hν, the band gap is established at E{sub g} = 0.37 eV.

Staying True to Our PBS Roots in a Changing World

Science.gov (United States)

Kincaid, Don

2018-01-01

The field of Positive Behavior Support (PBS) has grown and changed significantly in the past 25 years and should be expected to continue that trend for the next 25 years. These changes cannot always be predicted, but they can be managed by considering some current changes to the definition of PBS (Kincaid et al., 2016). This paper discussed how…

γ-ray radiation effect on properties of straw powder/PBS composite

International Nuclear Information System (INIS)

Yang Mingcheng; Luo Yongquan; Liu Wentao; Zhu Jun; Guo Dongquan; Li Zhaopeng; Gen Feng; Qu Lingbo

2013-01-01

Background: In recent years, with decreasing global fossil resources and increasing 'white pollution', renewable and biodegradable materials attract more and more attentions. Poly (butylene succinate) (PBS) has good mechanical property, biodegradability and processing performance, which is the focus of hot topics in the study of biodegradable plastic materials, however, being soft and of high cost, it is still limited in application range. Purpose: In order to improve the mechanical and thermal properties, a series of wheat straw powder/PBS composites were prepared by melt extrusion, and then the 60 Co-y ray was directly utilized to irradiate the straw powder/PBS composite. Methods: The influence of TAIC (triallyl isocyanurate) radiation absorbed dose and radiation sensitizer on the mechanical property and thermal performance of straw powder/PBS composite was investigated, and the impact fracture surface morphology of the composite was observed by SEM (scanning electron microscope). Results: The tensile strength and flexural strength were enhanced with increasing radiation dosage, and then tend to be stable, the heat distortion temperature also increased but not significantly with increasing radiation dosage. The results show that when TAIC content is 2%, with straw powder/PBS composite irradiated by 30-kGy dose, the tensile strength and flexural strength are increased by 26% and 39.8%, respectively. Conclusion: The radiation modification of composite material has no effect on thermal stability, but do improve the tensile strength and flexural strength when up to 2% of TAIC is integrated and irradiated by certain dose. The interface cohesiveness between straw powder and PBS is strengthened after radiation. (authors)

Weekend Science Project

Science.gov (United States)

Santos, Karey

2012-01-01

Weekend plans...every family has them. Whether it's fishing, swimming, or simply picnicking by the river, water plays a significant role in many recreational endeavors. Encouraging students and their families to use their "scientific eyes" to explore these wonderful wet places is what Weekend Science Project is all about. Weekend Science Project…

Multiscale science for science-based stockpile stewardship

Energy Technology Data Exchange (ETDEWEB)

Margolin, L.; Sharp, D.

2000-12-01

This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goal of this project has been to develop and apply the methods of multi scale science to the problems of fluid and material mixing due to instability and turbulence, and of materials characterization. Our specific focus has been on the SBSS (science-based stockpile stewardship) issue of assessing the performance of a weapons with off-design, aged, or remanufactured components in the absence of full-scale testing. Our products are physics models, based on microphysical principles and parameters, and suitable for implementation in the large scale design and assessment codes used in the nuclear weapons program.

The LOFAR Transients Key Science Project

NARCIS (Netherlands)

Stappers, B.; Fender, R.; Wijers, R.

2009-01-01

The Transients Key Science Project (TKP) is one of six Key Science Projects of the next generation radio telescope LOFAR. Its aim is the study of transient and variable low-frequency radio sources with an extremely broad science case ranging from relativistic jet sources to pulsars, exoplanets,

Projecting the Future for Design Science Research: An Action‐Case Based Analysis

DEFF Research Database (Denmark)

Baskerville, Richard; Pries-Heje, Jan

2015-01-01

and theories appears to be a key challenge. In this paper we commence with a DESRIST paper from 2012 that instantiated design principles in an artifact for a bank. That paper included plans and techniques for future use of its principles (propagation), including prescriptions for a five-phase adoption process...... or theories have stimulated many actual projections. We demonstrate these concepts in a case study of propagation: a chemical manufacturer and service provider that adopted the design principles arising from that 2012 DESRIST banking-based design science research. We conclude that generalizability is too well...

20% Research & Design Science Project

Science.gov (United States)

Spear, Beth A.

2015-04-01

A project allowing employees to use 15 % of their time on independent projects was established at 3M in the 1950's. The result of this project included products like post it notes and masking tape. Google allows its employees to use 20% of their time on independently pursued projects. The company values creativity and innovation. Employees are allowed to explore projects of interest to them one day out of the week, 20 % of their work week. Products like AdSense, Gmail, Google Transit, Google News, and Google Talk are the result of this 20 % program. My school is implementing the Next Generation Science Standards (NGSS) as part of our regularly scheduled curriculum review. These new standards focus on the process of learning by doing and designing. The NGSS are very hands on and active. The new standards emphasize learning how to define, understand and solve problems in science and technology. In today's society everyone needs to be familiar with science and technology. This project allows students to develop and practice skills to help them be more comfortable and confident with science and technology while exploring something of interest to them. This project includes three major parts: research, design, and presentation. Students will spend approximately 2-4 weeks defining a project proposal and educating themselves by researching a science and technology topic that is of interest to them. In the next phase, 2-4 weeks, students design a product or plan to collect data for something related to their topic. The time spent on research and design will be dependant on the topic students select. Projects should be ambitious enough to encompass about six weeks. Lastly a presentation or demonstration incorporating the research and design of the project is created, peer reviewed and presented to the class. There are some problems anticipated or already experienced with this project. It is difficult for all students to choose a unique topic when you have large class sizes

Controlled self-assembly of PbS nanoparticles into macrostar-like hierarchical structures

International Nuclear Information System (INIS)

Li, Guowei; Li, Changsheng; Tang, Hua; Cao, Kesheng; Chen, Juan

2011-01-01

Graphical abstract: The aggregation and rotation of nanoparticles to adopt parallel orientations in three dimensions was indirectly illustrated by TEM and HRTEM images. Highlights: → Macrostar-like PbS hierarchical structures was successfully synthesized by a simple hydrothermal method and mesostars were assembled from the PbS nanocube building blocks with edge lengths of about 100 nm. → Ostwald-ripening-assisted oriented attachment is believed to play a key role in the growth behavior of novel 3D structures. → Optical properties indicating few defects on the surface of the PbS structure and exhibit large blue-shifts compared to bulk PbS. -- Abstract: The synthesis of macrostar-like PbS hierarchical structures by a simple hydrothermal method at 180 o C for 24 h is proven successful with the assistance of a new surfactant called tetrabutylammonium bromide (TBAB). The as-obtained product is characterized by means of X-ray powder diffraction, field emission scanning electron microscopy, energy dispersive spectrometry, high resolution transmission electron microscopy, and selected area electron diffraction. The presence of TBAB and NaF plays an important role in the formation of PbS macrostructures. Ostwald-ripening-assisted oriented attachment is believed to play a key role in the growth behavior of novel 3D structures. As such, a possible self-assembly mechanism is proposed to explain the formation of the said structures. The present study aims to introduce new insights into understanding the formation process of such unique hierarchical superstructures.

Computer Assisted Project-Based Instruction: The Effects on Science Achievement, Computer Achievement and Portfolio Assessment

Science.gov (United States)

Erdogan, Yavuz; Dede, Dinçer

2015-01-01

The purpose of this study is to compare the effects of computer assisted project-based instruction on learners' achievement in a science and technology course, in a computer course and in portfolio development. With this aim in mind, a quasi-experimental design was used and a sample of 70 seventh grade secondary school students from Org. Esref…

Improving 4D plan quality for PBS-based liver tumour treatments by combining online image guided beam gating with rescanning

Science.gov (United States)

Zhang, Ye; Knopf, Antje-Christin; Weber, Damien Charles; Lomax, Antony John

2015-10-01

Pencil beam scanned (PBS) proton therapy has many advantages over conventional radiotherapy, but its effectiveness for treating mobile tumours remains questionable. Gating dose delivery to the breathing pattern is a well-developed method in conventional radiotherapy for mitigating tumour-motion, but its clinical efficiency for PBS proton therapy is not yet well documented. In this study, the dosimetric benefits and the treatment efficiency of beam gating for PBS proton therapy has been comprehensively evaluated. A series of dedicated 4D dose calculations (4DDC) have been performed on 9 different 4DCT(MRI) liver data sets, which give realistic 4DCT extracting motion information from 4DMRI. The value of 4DCT(MRI) is its capability of providing not only patient geometries and deformable breathing characteristics, but also includes variations in the breathing patterns between breathing cycles. In order to monitor target motion and derive a gating signal, we simulate time-resolved beams’ eye view (BEV) x-ray images as an online motion surrogate. 4DDCs have been performed using three amplitude-based gating window sizes (10/5/3 mm) with motion surrogates derived from either pre-implanted fiducial markers or the diaphragm. In addition, gating has also been simulated in combination with up to 19 times rescanning using either volumetric or layered approaches. The quality of the resulting 4DDC plans has been quantified in terms of the plan homogeneity index (HI), total treatment time and duty cycle. Results show that neither beam gating nor rescanning alone can fully retrieve the plan homogeneity of the static reference plan. Especially for variable breathing patterns, reductions of the effective duty cycle to as low as 10% have been observed with the smallest gating rescanning window (3 mm), implying that gating on its own for such cases would result in much longer treatment times. In addition, when rescanning is applied on its own, large differences between volumetric

All-solution-processed PbS quantum dot solar modules

Science.gov (United States)

Jang, Jihoon; Shim, Hyung Cheoul; Ju, Yeonkyeong; Song, Jung Hoon; An, Hyejin; Yu, Jong-Su; Kwak, Sun-Woo; Lee, Taik-Min; Kim, Inyoung; Jeong, Sohee

2015-05-01

A rapid increase in power conversion efficiencies in colloidal quantum dot (QD) solar cells has been achieved recently with lead sulphide (PbS) QDs by adapting a heterojunction architecture, which consists of small-area devices associated with a vacuum-deposited buffer layer with metal electrodes. The preparation of QD solar modules by low-cost solution processes is required to further increase the power-to-cost ratio. Herein we demonstrate all-solution-processed flexible PbS QD solar modules with a layer-by-layer architecture comprising polyethylene terephthalate (PET) substrate/indium tin oxide (ITO)/titanium oxide (TiO2)/PbS QD/poly(3-hexylthiophene) (P3HT)/poly(3,4-ethylenedioxythiophene) : poly(styrene sulfonate) (PEDOT : PSS)/Ag, with an active area of up to 30 cm2, exhibiting a power conversion efficiency (PCE) of 1.3% under AM 1.5 conditions (PCE of 2.2% for a 1 cm2 unit cell). Our approach affords trade-offs between power and the active area of the photovoltaic devices, which results in a low-cost power source, and which is scalable to larger areas.A rapid increase in power conversion efficiencies in colloidal quantum dot (QD) solar cells has been achieved recently with lead sulphide (PbS) QDs by adapting a heterojunction architecture, which consists of small-area devices associated with a vacuum-deposited buffer layer with metal electrodes. The preparation of QD solar modules by low-cost solution processes is required to further increase the power-to-cost ratio. Herein we demonstrate all-solution-processed flexible PbS QD solar modules with a layer-by-layer architecture comprising polyethylene terephthalate (PET) substrate/indium tin oxide (ITO)/titanium oxide (TiO2)/PbS QD/poly(3-hexylthiophene) (P3HT)/poly(3,4-ethylenedioxythiophene) : poly(styrene sulfonate) (PEDOT : PSS)/Ag, with an active area of up to 30 cm2, exhibiting a power conversion efficiency (PCE) of 1.3% under AM 1.5 conditions (PCE of 2.2% for a 1 cm2 unit cell). Our approach affords trade

The novice and the expert: How gender and experience influence student participation, interest and learning in an Internet-based science project

Science.gov (United States)

Mistler-Jackson, Megan Elizabeth

The purpose of this study is to examine how gender issues influence middle school students' participation, interest and learning in an Internet-based science curriculum project. One central question is whether using the Internet for communication and collaboration might serve as an entree into science and computer technology for those who are otherwise disinterested. Five students and their teacher were observed for five weeks and interviewed at the end of their participation in the Journey North Internet-based science project. Other methods of data collection included field notes, journal writing, and document review. Data were analyzed using ethnographic and case study methodology. Results revealed that boys were viewed as science and computer experts by themselves and by their peers more often than girls, both when they were and were not more knowledgeable. Data also showed that the teacher's inexperience with computers and the Journey North project was a more significant factor in student learning than gender. Findings with two students support the notion that using the Internet for communication and collaboration may encourage participation in computer technology by students like them. These results add to literatures that document the gender gap in science and computing and complement research on the incorporation of the Internet in the classroom. This study examines participation and interest from students' points of view, confirms the central role teachers play in enacting network science projects effectively and identifies several challenges this teacher faced in learning to utilize new technologies.

Solution-processed nanocrystalline PbS on paper substrate with pencil traced electrodes as visible photodetector

Science.gov (United States)

Vankhade, Dhaval; Chaudhuri, Tapas K.

2018-04-01

Paper-based PbS photodetector sensitive in the visible spectrum is reported. Nanocrystalline PbS-on-paper devices are fabricated by a spin coating method on white paper (300 GSM) from a methanolic precursor solution. Photodetector cells of gap 0.2 cm and length 0.5 cm are prepared by drawing contacts by monolithic cretacolor 8B pencil. X-ray diffractometer confirmed the deposition of nanocrystalline PbS films with 14 nm crystallites. The SEM illustrated the uniform coating of nanocrystalline PbS thin films on cellulose fibres of papers having an average thickness of fibres are 10 µm. The linear J-V characteristics in dark and under illumination of light using graphite trace on nanocrystalline PbS-on-paper shows good ohmic contact. The resistivity of pencil trace is 30 Ω.cm. Spectral response measurements of photodetector reveal the excellent sensitivity from 400 to 700 nm with a peak at 550 nm. The best responsivity anddetectivity are 0.7 A/W and 1.4 × 1012 Jones respectively. These paper-based low-cost photodetectors devices have fast photoresponse and recovery without baseline deviation.

The Effect of Project-Based History and Nature of Science Practices on the Change of Nature of Scientific Knowledge

Science.gov (United States)

Çibik, Ayse Sert

2016-01-01

The aim of this study is to compare the change of pre-service science teachers' views about the nature of scientific knowledge through Project-Based History and Nature of Science training and Conventional Method. The sample of the study consists of two groups of 3rd grade undergraduate students attending teacher preparation program of science…

A Study on the Evaluation of Science Projects of Primary School Students Based on Scientific Criteria

Science.gov (United States)

Gungor, Sema Nur; Ozer, Dilek Zeren; Ozkan, Muhlis

2013-01-01

This study re-evaluated 454 science projects that were prepared by primary school students between 2007 and 2011 within the scope of Science Projects Event for Primary School Students. Also, submitted to TUBITAK BIDEB Bursa regional science board by MNE regional work groups in accordance with scientific research methods and techniques, including…

Overview of Neutron Science Project

Energy Technology Data Exchange (ETDEWEB)

Mukaiyama, Takehiko [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1997-11-01

JAERI has launched the Neutron Science Project which aims at bringing scientific and technological innovation for the 21st century in the fields of basic science and nuclear technology using a high power spallation neutron source. The Project is preparing the design for a high intensity pulsed and cw spallation neutron sources for such basic science as neutron structural biology, material science, and for accelerator-driven transmutation of long-lived radio-nuclides which are associated with nuclear power generation. The major facilities to be constructed under the Project are, (1) a super-conducting proton linac with the proton energy of 1.5 GeV and the maximum beam power of 8 MW, (2) a spallation target station with input beam power of 5 MW allowing high intensity pulsed neutron beams for neutron scattering, and (3) research facility complex for accelerator-driven transmutation experiments, neutron physics, material irradiation, isotopes production, spallation produced RI beam experiments for exotic nuclei investigation. (author)

Overview of Neutron Science Project

International Nuclear Information System (INIS)

Mukaiyama, Takehiko

1997-01-01

JAERI has launched the Neutron Science Project which aims at bringing scientific and technological innovation for the 21st century in the fields of basic science and nuclear technology using a high power spallation neutron source. The Project is preparing the design for a high intensity pulsed and cw spallation neutron sources for such basic science as neutron structural biology, material science, and for accelerator-driven transmutation of long-lived radio-nuclides which are associated with nuclear power generation. The major facilities to be constructed under the Project are, 1) a super-conducting proton linac with the proton energy of 1.5 GeV and the maximum beam power of 8 MW, 2) a spallation target station with input beam power of 5 MW allowing high intensity pulsed neutron beams for neutron scattering, and 3) research facility complex for accelerator-driven transmutation experiments, neutron physics, material irradiation, isotopes production, spallation produced RI beam experiments for exotic nuclei investigation. (author)

Teachers' tendencies to promote student-led science projects: Associations with their views about science

Science.gov (United States)

Bencze, J. Lawrence; Bowen, G. Michael; Alsop, Steve

2006-05-01

School science students can benefit greatly from participation in student-directed, open-ended scientific inquiry projects. For various possible reasons, however, students tend not to be engaged in such inquiries. Among factors that may limit their opportunities to engage in open-ended inquiries of their design are teachers' conceptions about science. To explore possible relationships between teachers' conceptions about science and the types of inquiry activities in which they engage students, instrumental case studies of five secondary science teachers were developed, using field notes, repertory grids, samples of lesson plans and student activities, and semistructured interviews. Based on constructivist grounded theory analysis, participating teachers' tendencies to promote student-directed, open-ended scientific inquiry projects seemed to correspond with positions about the nature of science to which they indicated adherence. A tendency to encourage and enable students to carry out student-directed, open-ended scientific inquiry projects appeared to be associated with adherence to social constructivist views about science. Teachers who opposed social constructivist views tended to prefer tight control of student knowledge building procedures and conclusions. We suggest that these results can be explained with reference to human psychological factors, including those associated with teachers' self-esteem and their relationships with knowledge-building processes in the discipline of their teaching.

Investigating Changes in Student Attitudes and Understanding of Science through Participation in Citizen Science Projects in College Coursework

Science.gov (United States)

Cardamone, Carolin; Cobb, Bethany E.

2018-01-01

Over the last decade, web-based “citizen science” projects such as the Zooniverse have allowed volunteers and professional scientists to work together for the advancement of science. While much attention has been paid to the benefits to science from these new projects, less attention has been paid to their impact on the participants and, in particular, to the projects’ potential to impact students who might engage in these projects through coursework. We report on a study engaging students in introductory astronomy classes at the George Washington University and Wheelock College in an assignment in which each student individually contributed to a “physics” or “space” citizen science project of their choice, and groups of students worked together to understand and articulate the scientific purpose of a citizen science project to which they all contributed. Over the course of approximately four weeks, the students kept logs of their individual contributions to the project, and recorded a brief reflection on each of their visits (noting, for example, interesting or confusing things they might encounter along the way). The project culminated with each group delivering a creative presentation that demonstrated their understanding of both the science goals of the project and the value of their own contributions to the project. In this talk, we report on the experience of the students with the project and on an assessment of the students’ attitudes toward science and knowledge of the process of science completed before the introduction of the assignment and again at its conclusion.

Citizen science projects for non-science astronomy students

OpenAIRE

Barmby, Pauline; Gallagher, S. C.; Cami, J.

2014-01-01

A poster from the 2011 Western Conference on Science Education, describing the use of citizen science project Galaxy Zoo in a non-majors astronomy course. Lots more on this topic at https://www.zooniverse.org/education  

Project LAUNCH: Bringing Space into Math and Science Classrooms

Science.gov (United States)

Fauerbach, M.; Henry, D. P.; Schmidt, D. L.

2005-01-01

Project LAUNCH is a K-12 teacher professional development program, which has been created in collaboration between the Whitaker Center for Science, Mathematics and Technology Education at Florida Gulf Coast University (FGCU), and the Florida Space Research Institute (FSRI). Utilizing Space as the overarching theme it is designed to improve mathematics and science teaching, using inquiry based, hands-on teaching practices, which are aligned with Florida s Sunshine State Standards. Many students are excited about space exploration and it provides a great venue to get them involved in science and mathematics. The scope of Project LAUNCH however goes beyond just providing competency in the subject area, as pedagogy is also an intricate part of the project. Participants were introduced to the Conceptual Change Model (CCM) [1] as a framework to model good teaching practices. As the CCM closely follows what scientists call the scientific process, this teaching method is also useful to actively engage institute participants ,as well as their students, in real science. Project LAUNCH specifically targets teachers in low performing, high socioeconomic schools, where the need for skilled teachers is most critical.

Citizens Science for Sustainability (SuScit) Project Briefing

DEFF Research Database (Denmark)

Eames, Malcolm; Mortensen, Jonas Egmose; Adebowale, Maria

This project briefing gives a short overview of the Citizens Science for Sustainability (SuScit) Project.......This project briefing gives a short overview of the Citizens Science for Sustainability (SuScit) Project....

SU-E-T-266: Proton PBS Plan Design and Robustness Evaluation for Head and Neck Cancers

International Nuclear Information System (INIS)

Liang, X; Tang, S; Zhai, H; Kirk, M; Kalbasi, A; Lin, A; Ahn, P; Tochner, Z; McDonough, J; Both, S

2014-01-01

Purpose: To describe a newly designed proton pencil beam scanning (PBS) planning technique for radiotherapy of patients with bilateral oropharyngeal cancer, and to assess plan robustness. Methods: We treated 10 patients with proton PBS plans using 2 posterior oblique field (2F PBS) comprised of 80% single-field uniform dose (SFUD) and 20% intensity-modulated proton therapy (IMPT). All patients underwent weekly CT scans for verification. Using dosimetric indicators for both targets and organs at risk (OARs), we quantitatively compared initial plans and verification plans using student t-tests. We created a second proton PBS plan for each patient using 2 posterior oblique plus 1 anterior field comprised of 100% SFUD (3F PBS). We assessed plan robustness for both proton plan groups, as well as a photon volumetric modulated arc therapy (VMAT) plan group by comparing initial and verification plans. Results: The 2F PBS plans were not robust in target coverage. D98% for clinical target volume (CTV) degraded from 100% to 96% on average, with maximum change Δ D98% of −24%. Two patients were moved to photon VMAT treatment due to insufficient CTV coverage on verification plans. Plan robustness was especially weak in the low-anterior neck. The 3F PBS plans, however, demonstrated robust target coverage, which was comparable to the VMAT photon plan group. Doses to oral cavity were lower in the Proton PBS plans compared to photon VMAT plans due to no lower exit dose to the oral cavity. Conclusion: Proton PBS plans using 2 posterior oblique fields were not robust for CTV coverage, due to variable positioning of redundant soft tissue in the posterior neck. We designed 3-field proton PBS plans using an anterior field to avoid long heterogeneous paths in the low neck. These 3-field proton PBS plans had significantly improved plan robustness, and the robustness is comparable to VMAT photon plans

Study of structural and optical properties of PbS thin films

Science.gov (United States)

Homraruen, T.; Sudswasd, Y.; Sorod, R.; Kayunkid, N.; Yindeesuk, W.

2018-03-01

This research aimed to synthesize lead sulfide (PbS) thin films on glass slides using the successive ion layer absorption and reaction (SILAR) method. We studied the optical properties and structure of PbS thin films by changing the number of dipping cycles and the concentration of precursor solution. The results of this experiment show that different conditions have a considerable influence on the thickness and absorbance of the films. When the number of dipping cycles and the concentration of the solution are increased, film thickness and absorbance tend to become higher. The xrays diffraction pattern showed all the diffraction peaks which confirmed the face center cubic and the structure of PbS had identified. Grain size computation was used to confirm how much these conditions could be affected.

Conservation Science Fair Projects.

Science.gov (United States)

Soil Conservation Society of America, Ankeny, IA.

Included are ideas, suggestions, and examples for selecting and designing conservation science projects. Over 70 possible conservation subject areas are presented with suggested projects. References are cited with each of these subject areas, and a separate list of annotated references is included. The references pertain to general subject…

Multi-Role Project (MRP): A New Project-Based Learning Method for STEM

Science.gov (United States)

Warin, Bruno; Talbi, Omar; Kolski, Christophe; Hoogstoel, Frédéric

2016-01-01

This paper presents the "Multi-Role Project" method (MRP), a broadly applicable project-based learning method, and describes its implementation and evaluation in the context of a Science, Technology, Engineering, and Mathematics (STEM) course. The MRP method is designed around a meta-principle that considers the project learning activity…

Neutron Science Project at JAERI

International Nuclear Information System (INIS)

Oyama, Yukio

1998-01-01

Japan Atomic Energy Research Institute, JAERI, is proposing the Neutron Science Project which aims at bringing about scientific and technological innovation in the fields of basic science and nuclear technology for the 21st century, using high intense spallation neutron source. The research areas to be promoted by the project are neutron structural biology, material science, nuclear physics and various technology developments for accelerator-driven transmutation of long-lived radionuclides which are associated with nuclear power generation. JAERI has been carrying out a R and D program for the partitioning and transmutation with the intention to solve the problem of nuclear fuel cycle backend. The accelerator-driven transmutation study is also covered with this program. In the present stage of the project, a conceptual design is being prepared for a research complex utilizing spallation neutrons, including a high intensity pulsed and steady spallation neutron source with 1.5 GeV and 8 MW superconducting proton linac. The idea and facility plan of the project is described, including the status of technological development of the accelerator, target and facilities. (author)

Neutron Science Project at JAERI

Energy Technology Data Exchange (ETDEWEB)

Oyama, Yukio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1998-03-01

Japan Atomic Energy Research Institute, JAERI, is proposing the Neutron Science Project which aims at bringing about scientific and technological innovation in the fields of basic science and nuclear technology for the 21st century, using high intense spallation neutron source. The research areas to be promoted by the project are neutron structural biology, material science, nuclear physics and various technology developments for accelerator-driven transmutation of long-lived radionuclides which are associated with nuclear power generation. JAERI has been carrying out a R and D program for the partitioning and transmutation with the intention to solve the problem of nuclear fuel cycle backend. The accelerator-driven transmutation study is also covered with this program. In the present stage of the project, a conceptual design is being prepared for a research complex utilizing spallation neutrons, including a high intensity pulsed and steady spallation neutron source with 1.5 GeV and 8 MW superconducting proton linac. The idea and facility plan of the project is described, including the status of technological development of the accelerator, target and facilities. (author)

Animal Science Project

International Nuclear Information System (INIS)

Anon.

Researches carried out in the 'Animal Science Project' of the Agricultural Nuclear Energy Center, Piracicaba, Sao Paulo state, Brazil, are described. Such researches comprise : immunology and animal nutrition. Tracer techniques are employed in this study. (M.A.) [pt

Plant Biology Science Projects.

Science.gov (United States)

Hershey, David R.

This book contains science projects about seed plants that deal with plant physiology, plant ecology, and plant agriculture. Each of the projects includes a step-by-step experiment followed by suggestions for further investigations. Chapters include: (1) "Bean Seed Imbibition"; (2) "Germination Percentages of Different Types of Seeds"; (3)…

Chemical bath deposited PbS thin films on ZnO nanowires for photovoltaic applications

Energy Technology Data Exchange (ETDEWEB)

Gertman, Ronen [Dept of Chemistry, Ben Gurion University of the Negev, Be' er Sheva 84105 (Israel); Ilse Katz Institute for Nanoscale Science and Technology, Ben Gurion University of the Negev, Be' er Sheva 84105 (Israel); Osherov, Anna; Golan, Yuval [Dept of Materials Engineering, Ben Gurion University of the Negev, Be' er Sheva 84105 (Israel); Ilse Katz Institute for Nanoscale Science and Technology, Ben Gurion University of the Negev, Be' er Sheva 84105 (Israel); Visoly-Fisher, Iris, E-mail: irisvf@bgu.ac.il [Ilse Katz Institute for Nanoscale Science and Technology, Ben Gurion University of the Negev, Be' er Sheva 84105 (Israel); Department of Solar Energy and Environmental Physics, Swiss Institute for Dryland Environmental and Energy Research, Jacob Blaustein Institutes for Desert Research, Ben Gurion University of the Negev, Sede Boqer Campus 84990 (Israel)

2014-01-01

Photovoltaic devices usually exploit mid-range band-gap semiconductors which absorb in the visible range of the solar spectrum. However, much energy is lost in the IR and near-IR range. We combined the advantages of small band-gap, bulk-like PbS deposited by facile, cheap and direct chemical bath deposition (CBD), with the good electronic properties of ZnO and the large surface area of nanowires, towards low cost photovoltaic devices utilizing IR and near-IR light. Surprisingly, CBD of PbS on ZnO, and particularly on ZnO nanowires, was not studied hitherto. Therefore, the mechanism of PbS growth by chemical bath deposition on ZnO nanowires was studied in details. A visible proof is shown for a growth mechanism starting from amorphous Pb(OH){sub 2} layer, that evolved into the ‘ion-by-ion’ growth mechanism. The growth mechanism and the resulting morphology at low temperatures were controlled by the thiourea concentration. The grain size affected the magnitude of the band-gap and was controlled by the deposition temperatures. Deposition above 40 °C resulted in bulk-like PbS with an optical band-gap of 0.4 eV. Methods were demonstrated for achieving complete PbS coverage of the complex ZnO NW architecture, a crucial requirement in optoelectronic devices to prevent shorts. Measurements of photocurrents under white and near-IR (784 nm) illumination showed that despite a 200 meV barrier for electron transfer at the PbS/ZnO interface, extraction of photo-electrons from PbS to the ZnO was feasible. The ability to harvest electrons from a narrow band-gap semiconductor deposited on a large surface-area electrode can advance the field towards high efficiency, low cost IR and near-IR sensors and third generation solar cells. - Highlights: • PbS was deposited on ZnO nanowires using chemical bath deposition. • At 50 °C the growth mechanism starts from an amorphous Pb(OH){sub 2} layer. • At 5 °C the growth mechanism of PbS can be controlled by thiourea concentrations

ASSESSMENT OF THE INQUIRY-BASED PROJECT IMPLEMENTATION PROCESS IN SCIENCE EDUCATION UPON STUDENTS’ POINTS OF VIEWS

Directory of Open Access Journals (Sweden)

Orhan AKINOGLU

2008-01-01

Full Text Available Aim of the study is to assess how students in 6th, 7th and 8th grades of primary education see the project works made in science education and their implementation processes. The study was fulfilled upon the descriptive survey model to collect data. Participants of the research were 100 students who had project implementation experiences in science education, and they were from 24 primary schools in 7 districts randomly chosen in the city of Istanbul in Turkey. Data of the study were collected by using a semi-constructed interview form offered to students during the 2005-2006 teaching year. In the research, following items were examined: The extent to which students are inspired from the previously made projects during their own project selection process, the level of scientific document survey and the effects of contemporary events, science and technology class topics and students’ interest areas. It was seen that internet is the mostly used source to obtain information. For students, one of the most problematic issues faced during the project implementation is the time limits set out by teacher. It was found that the most obvious benefit obtained by students from the project works is their increasing interest towards science and technology class. The most significant change seen by students regarding project preparation is their increasing grades in exams during and following the project works.

Project Lifescape | Initiatives | Indian Academy of Sciences

Indian Academy of Sciences (India)

Project Lifescape. This project is part of the Academy initiative to enhance the quality of science education. It is pursued in collaboration with the Centre for Ecological Sciences at the Indian Institute of Science to spread biodiversity literacy, expecially within the high school and college student community, and to involve them ...

Chemically synthesized PbS Nano particulate thin films for a rapid NO2 gas sensor

Directory of Open Access Journals (Sweden)

Burungale Vishal V.

2016-03-01

Full Text Available Rapid NO2 gas sensor has been developed based on PbS nanoparticulate thin films synthesized by Successive Ionic Layer Adsorption and Reaction (SILAR method at different precursor concentrations. The structural and morphological properties were investigated by means of X-ray diffraction and field emission scanning electron microscope. NO2 gas sensing properties of PbS thin films deposited at different concentrations were tested. PbS film with 0.25 M precursor concentration showed the highest sensitivity. In order to optimize the operating temperature, the sensitivity of the sensor to 50 ppm NO2 gas was measured at different operating temperatures, from 50 to 200 °C. The gas sensitivity increased with an increase in operating temperature and achieved the maximum value at 150 °C, followed by a decrease in sensitivity with further increase of the operating temperature. The sensitivity was about 35 % for 50 ppm NO2 at 150 °C with rapid response time of 6 s. T90 and T10 recovery time was 97 s at this gas concentration.

ScienceDesk Project Overview

Science.gov (United States)

Keller, Richard M.; Norvig, Peter (Technical Monitor)

2000-01-01

NASA's ScienceDesk Project at the Ames Research Center is responsible for scientific knowledge management which includes ensuring the capture, preservation, and traceability of scientific knowledge. Other responsibilities include: 1) Maintaining uniform information access which is achieved through intelligent indexing and visualization, 2) Collaborating both asynchronous and synchronous science teamwork, 3) Monitoring and controlling semi-autonomous remote experimentation.

Project Mapping to Build Capacity and Demonstrate Impact in the Earth Sciences

Science.gov (United States)

Hemmings, S. N.; Searby, N. D.; Murphy, K. J.; Mataya, C. J.; Crepps, G.; Clayton, A.; Stevens, C. L.

2017-12-01

Diverse organizations are increasingly using project mapping to communicate location-based information about their activities. NASA's Earth Science Division (ESD), through the Earth Science Data Systems and Applied Sciences' Capacity Building Program (CBP), has created a geographic information system of all ESD projects to support internal program management for the agency. The CBP's NASA DEVELOP program has built an interactive mapping tool to support capacity building for the program's varied constituents. This presentation will explore the types of programmatic opportunities provided by a geographic approach to management, communication, and strategic planning. We will also discuss the various external benefits that mapping supports and that build capacity in the Earth sciences. These include activities such as project matching (location-focused synergies), portfolio planning, inter- and intra-organizational collaboration, science diplomacy, and basic impact analysis.

Science and the city: A visual journey towards a critical place based science education

Science.gov (United States)

Ibrahim, Sheliza

The inclusion of societal and environmental considerations during the teaching and learning of science and technology has been a central focus among science educators for many decades. Major initiatives in science and technology curriculum advocate for science, technology, society and environment (STSE). Yet, it is surprising that despite these longstanding discussions, it is only recently that a handful of researchers have turned to students' 'places' (and the literature of place based education) to serve as a source of teaching and learning in science education. In my study, I explore three issues evident in place based science education. First, it seems that past scholarship focused on place-based projects which explore issues usually proposed by government initiatives, university affiliation, or community organizations. Second, some of the studies fail to pay extended attention to the collaborative and intergenerational agency that occurs between researcher, teacher, student, and community member dynamics, nor does it share the participatory action research process in order to understand how teacher practice, student learning, and researcher/local collaborations might help pedagogy emerge. The third issue is that past place-based projects, rarely if ever, return to the projects to remember the collaborative efforts and question what aspects sustained after they were complete. To address these issues, I propose a critical place based science education (CPBSE) model. I describe a participatory action research project that develops and explores the CPBSE model. The data were gathered collaboratively among teachers, researchers, and students over 3 years (2006-2008), via digital video ethnography, photographs, and written reflections. The data were analysed using a case study approach and the constant comparative method. I discuss the implications for its practice in the field of STSE and place based education. I conclude that an effective pedagogical model of

Collaborative Project-Based Learning: An Integrative Science and Technological Education Project

Science.gov (United States)

Baser, Derya; Ozden, M. Yasar; Karaarslan, Hasan

2017-01-01

Background: Blending collaborative learning and project-based learning (PBL) based on Wolff (2003) design categories, students interacted in a learning environment where they developed their technology integration practices as well as their technological and collaborative skills. Purpose: The study aims to understand how seventh grade students…

Homogenisation in project management for large German research projects in the Earth system sciences: overcoming the institutional coordination bias

Science.gov (United States)

Rauser, Florian; Vamborg, Freja

2016-04-01

The interdisciplinary project on High Definition Clouds and Precipitation for advancing climate prediction HD(CP)2 (hdcp2.eu) is an example for the trend in fundamental research in Europe to increasingly focus on large national and international research programs that require strong scientific coordination. The current system has traditionally been host-based: project coordination activities and funding is placed at the host institute of the central lead PI of the project. This approach is simple and has the advantage of strong collaboration between project coordinator and lead PI, while exhibiting a list of strong, inherent disadvantages that are also mentioned in this session's description: no community best practice development, lack of integration between similar projects, inefficient methodology development and usage, and finally poor career development opportunities for the coordinators. Project coordinators often leave the project before it is finalized, leaving some of the fundamentally important closing processes to the PIs. This systematically prevents the creation of professional science management expertise within academia, which leads to an automatic imbalance that hinders the outcome of large research programs to help future funding decisions. Project coordinators in academia often do not work in a professional project office environment that could distribute activities and use professional tools and methods between different projects. Instead, every new project manager has to focus on methodological work anew (communication infrastructure, meetings, reporting), even though the technological needs of large research projects are similar. This decreases the efficiency of the coordination and leads to funding that is effectively misallocated. We propose to challenge this system by creating a permanent, virtual "Centre for Earth System Science Management CESSMA" (cessma.com), and changing the approach from host- based to centre-based. This should

The Effects of Project Based Learning on Undergraduate Students' Achievement and Self-Efficacy Beliefs towards Science Teaching

Science.gov (United States)

Bilgin, Ibrahim; Karakuyu, Yunus; Ay, Yusuf

2015-01-01

The purpose of this study is to investigate the effects of the Project-Based Learning (PBL) method on undergraduate students' achievement and its association with these students' self-efficacy beliefs about science teaching and pinions about PBL. The sample of the study consisted of two randomly chosen classes from a set of seven classes enrolled…

In Situ Passivation for Efficient PbS Quantum Dot Solar Cells by Precursor Engineering.

Science.gov (United States)

Wang, Yongjie; Lu, Kunyuan; Han, Lu; Liu, Zeke; Shi, Guozheng; Fang, Honghua; Chen, Si; Wu, Tian; Yang, Fan; Gu, Mengfan; Zhou, Sijie; Ling, Xufeng; Tang, Xun; Zheng, Jiawei; Loi, Maria Antonietta; Ma, Wanli

2018-04-01

Current efforts on lead sulfide quantum dot (PbS QD) solar cells are mostly paid to the device architecture engineering and postsynthetic surface modification, while very rare work regarding the optimization of PbS synthesis is reported. Here, PbS QDs are successfully synthesized using PbO and PbAc 2  · 3H 2 O as the lead sources. QD solar cells based on PbAc-PbS have demonstrated a high power conversion efficiency (PCE) of 10.82% (and independently certificated values of 10.62%), which is significantly higher than the PCE of 9.39% for PbO-PbS QD based ones. For the first time, systematic investigations are carried out on the effect of lead precursor engineering on the device performance. It is revealed that acetate can act as an efficient capping ligands together with oleic acid, providing better surface coverage and replace some of the harmful hydroxyl (OH) ligands during the synthesis. Then the acetate on the surface can be exchanged by iodide and lead to desired passivation. This work demonstrates that the precursor engineering has great potential in performance improvement. It is also pointed out that the initial synthesis is an often neglected but critical stage and has abundant room for optimization to further improve the quality of the resultant QDs, leading to breakthrough efficiency. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Analyzing the Watershed Dynamics project as an example of successful science and education partnerships

Science.gov (United States)

Buzby, C. K.; Jona, K.

2009-12-01

The Watershed Dynamics project is a partnership between Northwestern University, the Consortium of Universities for the Advancement of Hydrologic Science (CUAHSI), and the GLOBE Program (Global Learning and Observations to Benefit the Environment). The goal of the project is to develop inquiry-based educational materials that use authentic scientific data and analysis techniques to teach students about the watershed. The relationship between Northwestern, CUAHSI, and GLOBE allows each partner to contribute to the development of the project in the area of their expertise. Science researchers from CUAHSI share science content knowledge and data access through the development of their Hydrologic Information System (HIS). Curriculum developers at Northwestern write inquiry-based curriculum using GIS technology to access and analyze live data. The GLOBE Program is a worldwide hands-on, primary and secondary school-based science education program that provides teacher training opportunities to a network of teachers around the world. This partnership allows each partner to bring their area of expertise to the project and make the best use of one another's resources. The Watershed Dynamics project can serve as a model for future partnerships between the science and education communities. The Office of Science, Technology, Engineering, and Math Education Partnerships (OSEP) at Northwestern is a service organization that supports Northwestern researchers in developing proposals and implementing research projects that incorporate K-12 educational components, particularly in the fields of science, technology, engineering and mathematics (STEM). OSEP assists faculty with the development of sound plans for education and outreach that reflect current research on learning and educational reform and provides expertise in STEM education materials development, learning technologies, and professional development for K-12 teachers and facilitators in informal education institutions

Spectroscopic evidence of resonance energy transfer mechanism from PbS QDs to bulk silicon

Directory of Open Access Journals (Sweden)

Bernechea M.

2013-06-01

Full Text Available In this work, we study the efficiency of the resonance energy transfer from PbS quantum dots to bulk silicon. We present spectroscopic evidence that resonance energy transfer from PbS quantum dots to bulk silicon can be an efficient process for separation distances below 12 nm. Temperature measurements are also presented for PbS quantum dots deposited on glass and silicon with 5 nm and 20nm spacer thicknesses substrates. Our findings show that the resonance energy transfer efficiency remains constant over the 50K to 300K temperature range.

Open-science projects get kickstarted at CERN

CERN Multimedia

Achintya Rao

2015-01-01

CERN is one of the host sites for the Mozilla Science Lab Global Sprint to be held on 4 and 5 June, which will see participants around the world work on projects to further open science and educational tools.   IdeaSquare will be hosting the event at CERN. The Mozilla Science Lab Global Sprint was first held in 2014 to bring together open-science practitioners and enthusiasts to collaborate on projects designed to advance science on the open web. The sprint is a loosely federated event, and CERN is participating in the 2015 edition, hosting sprinters in the hacker-friendly IdeaSquare. Five projects have been formally proposed and CERN users and staff are invited to participate in a variety of ways. A special training session will also be held to introduce the CERN community to existing open-science and collaborative tools, including ones that have been deployed at CERN. 1. GitHub Science Badges: Sprinters will work on developing a badge-style visual representation of how open a software pro...

Approaches to Teaching Plant Nutrition. Children's Learning in Science Project.

Science.gov (United States)

Leeds Univ. (England). Centre for Studies in Science and Mathematics Education.

During the period 1984-1986, over 30 teachers from the Yorkshire (England) region have worked in collaboration with the Children's Learning in Science Project (CLIS) developing and testing teaching schemes in the areas of energy, particle theory, and plant nutrition. The project is based upon the constructivist approach to teaching. This document…

Lessons Learned from Real-Time, Event-Based Internet Science Communications

Science.gov (United States)

Phillips, T.; Myszka, E.; Gallagher, D. L.; Adams, M. L.; Koczor, R. J.; Whitaker, Ann F. (Technical Monitor)

2001-01-01

For the last several years the Science Directorate at Marshall Space Flight Center has carried out a diverse program of Internet-based science communication. The Directorate's Science Roundtable includes active researchers, NASA public relations, educators, and administrators. The Science@NASA award-winning family of Web sites features science, mathematics, and space news. The program includes extended stories about NASA science, a curriculum resource for teachers tied to national education standards, on-line activities for students, and webcasts of real-time events. The focus of sharing science activities in real-time has been to involve and excite students and the public about science. Events have involved meteor showers, solar eclipses, natural very low frequency radio emissions, and amateur balloon flights. In some cases, broadcasts accommodate active feedback and questions from Internet participants. Through these projects a pattern has emerged in the level of interest or popularity with the public. The pattern differentiates projects that include science from those that do not, All real-time, event-based Internet activities have captured public interest at a level not achieved through science stories or educator resource material exclusively. The worst event-based activity attracted more interest than the best written science story. One truly rewarding lesson learned through these projects is that the public recognizes the importance and excitement of being part of scientific discovery. Flying a camera to 100,000 feet altitude isn't as interesting to the public as searching for viable life-forms at these oxygen-poor altitudes. The details of these real-time, event-based projects and lessons learned will be discussed.

A Comparison of Creativity in Project Groups in Science and Engineering Education in Denmark and China

DEFF Research Database (Denmark)

Zhou, Chunfang; Valero, Paola

2015-01-01

Different pedagogical strategies influence the development of creativity in project groups in science and engineering education. This study is a comparison between two cases: Problem-Based Learning (PBL) in Denmark and Project-Organized Learning (POL) in China.......Different pedagogical strategies influence the development of creativity in project groups in science and engineering education. This study is a comparison between two cases: Problem-Based Learning (PBL) in Denmark and Project-Organized Learning (POL) in China....

The Effectiveness of Project-based E-learning to Improve Ict Literacy

OpenAIRE

Eliana, E. D. S; Senam, Senam; Wilujeng, I; Jumadi, Jumadi

2016-01-01

This study aims to reveal the effectiveness of science teaching based on project-based learning to improve ICT literacy learners in the junior high school with the category of high, medium and low. This research uses descriptive method to describe the students’ equipness of ICT literacy in the science learning based on the project-based learning that is integrated with e-learning. All of the population in this study are junior high school of curriculum pilot project in 2013 in Singkawang. The...

Charge Carrier Conduction Mechanism in PbS Quantum Dot Solar Cells: Electrochemical Impedance Spectroscopy Study.

Science.gov (United States)

Wang, Haowei; Wang, Yishan; He, Bo; Li, Weile; Sulaman, Muhammad; Xu, Junfeng; Yang, Shengyi; Tang, Yi; Zou, Bingsuo

2016-07-20

With its properties of bandgap tunability, low cost, and substrate compatibility, colloidal quantum dots (CQDs) are becoming promising materials for optoelectronic applications. Additionally, solution-processed organic, inorganic, and hybrid ligand-exchange technologies have been widely used in PbS CQDs solar cells, and currently the maximum certified power conversion efficiency of 9.9% has been reported by passivation treatment of molecular iodine. Presently, there are still some challenges, and the basic physical mechanism of charge carriers in CQDs-based solar cells is not clear. Electrochemical impedance spectroscopy is a monitoring technology for current by changing the frequency of applied alternating current voltage, and it provides an insight into its electrical properties that cannot be measured by direct current testing facilities. In this work, we used EIS to analyze the recombination resistance, carrier lifetime, capacitance, and conductivity of two typical PbS CQD solar cells Au/PbS-TBAl/ZnO/ITO and Au/PbS-EDT/PbS-TBAl/ZnO/ITO, in this way, to better understand the charge carriers conduction mechanism behind in PbS CQD solar cells, and it provides a guide to design high-performance quantum-dots solar cells.

A New Project-Based Lab for Undergraduate Environmental and Analytical Chemistry

Science.gov (United States)

Adami, Gianpiero

2006-01-01

A new project-based lab was developed for third year undergraduate chemistry students based on real world applications. The experience suggests that the total analytical procedure (TAP) project offers a stimulating alternative for delivering science skills and developing a greater interest for analytical chemistry and environmental sciences and…

Influence of PbS nanoparticle polymer coating on their aggregation behavior and toxicity to the green algae Dunaliella salina

Energy Technology Data Exchange (ETDEWEB)

Zamani, Hajar [Department of Biology, Faculty of Sciences, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of); Moradshahi, Ali, E-mail: moradshahi@susc.ac.ir [Department of Biology, Faculty of Sciences, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of); Jahromi, Hamed Dehdashti; Sheikhi, Mohammad Hosein [Nanotechnology Research Institute, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of)

2014-09-15

Highlights: • Lead sulfide nanoparticles (PbS NPs) are toxic to D. salina. • Gum-Arabic coating alters the toxicity of PbS NPs. • Cell-NPs agglomerates and lipid peroxidation could explain the toxicity of PbS NPs. • Shading effect and dissolution do not seem to contribute to the toxicity of PbS NPs. • Particle–particle interaction was reduced by coating; therefore, PbS NPs were stabilized in the culture media. - Abstract: The potential hazards of nanoparticles (NPs) to the environment and to living organisms need to be considered for a safe development of nanotechnology. In the present study, the potential toxic effects of uncoated and gum Arabic-coated lead sulfide nanoparticles (GA-coated PbS NPs) on the growth, lipid peroxidation, reducing capacity and total carotenoid content of the hypersaline unicellular green algae Dunaliella salina were investigated. Coatings of PbS NPs with GA, as confirmed by Fourier transform infrared spectroscopy, reduced the toxicity of PbS NPs. Uncoated PbS NP toxicity to D. salina was attributed to higher algal cell-NP agglomerate formation, higher lipid peroxidation, lower content of total reducing substances and lower total carotenoid content. Low levels of Pb{sup 2+} in the growth culture media indicate that PbS NP dissolution does not occur in the culture. Also, the addition of 100 μM Pb{sup 2+} to the culture media had no significant (P > 0.05) effect on algal growth. The shading of light (shading effect) by PbS NPs, when simulated using activated charcoal, did not contribute to the overall toxic effect of PbS NPs which was evident by insignificant (P > 0.05) reduction in the growth and antioxidant capacity of the algae. When PbS NP aggregation in culture media (without algal cells) was followed for 60 min, uncoated form aggregated rapidly reaching aggregate sizes with hydrodynamic diameter of over 2500 nm within 60 min. Effective particle–particle interaction was reduced in the GA-coated NPs. Aggregates of about

Influence of PbS nanoparticle polymer coating on their aggregation behavior and toxicity to the green algae Dunaliella salina

International Nuclear Information System (INIS)

Zamani, Hajar; Moradshahi, Ali; Jahromi, Hamed Dehdashti; Sheikhi, Mohammad Hosein

2014-01-01

Highlights: • Lead sulfide nanoparticles (PbS NPs) are toxic to D. salina. • Gum-Arabic coating alters the toxicity of PbS NPs. • Cell-NPs agglomerates and lipid peroxidation could explain the toxicity of PbS NPs. • Shading effect and dissolution do not seem to contribute to the toxicity of PbS NPs. • Particle–particle interaction was reduced by coating; therefore, PbS NPs were stabilized in the culture media. - Abstract: The potential hazards of nanoparticles (NPs) to the environment and to living organisms need to be considered for a safe development of nanotechnology. In the present study, the potential toxic effects of uncoated and gum Arabic-coated lead sulfide nanoparticles (GA-coated PbS NPs) on the growth, lipid peroxidation, reducing capacity and total carotenoid content of the hypersaline unicellular green algae Dunaliella salina were investigated. Coatings of PbS NPs with GA, as confirmed by Fourier transform infrared spectroscopy, reduced the toxicity of PbS NPs. Uncoated PbS NP toxicity to D. salina was attributed to higher algal cell-NP agglomerate formation, higher lipid peroxidation, lower content of total reducing substances and lower total carotenoid content. Low levels of Pb 2+ in the growth culture media indicate that PbS NP dissolution does not occur in the culture. Also, the addition of 100 μM Pb 2+ to the culture media had no significant (P > 0.05) effect on algal growth. The shading of light (shading effect) by PbS NPs, when simulated using activated charcoal, did not contribute to the overall toxic effect of PbS NPs which was evident by insignificant (P > 0.05) reduction in the growth and antioxidant capacity of the algae. When PbS NP aggregation in culture media (without algal cells) was followed for 60 min, uncoated form aggregated rapidly reaching aggregate sizes with hydrodynamic diameter of over 2500 nm within 60 min. Effective particle–particle interaction was reduced in the GA-coated NPs. Aggregates of about 440 nm

Student cognition and motivation during the Classroom BirdWatch citizen science project

Science.gov (United States)

Tomasek, Terry Morton

The purpose of this study was to examine and describe the ways various stakeholders (CBW project developer/coordinator, elementary and middle school teachers, and 5th through 8th grade students) envisioned, implemented and engaged in the citizen science project, eBird/Classroom BirdWatch. A multiple case study mixed-methods research design was used to examine student engagement in the cognitive processes associated with scientific inquiry as part of citizen science participation. Student engagement was described based on a sense of autonomy, competence, relatedness and intrinsic motivation. A goal of this study was to expand the taxonomy of differences between authentic scientific inquiry and simple inquiry to include those inquiry tasks associated with participation in citizen science by describing how students engaged in this type of science. This research study built upon the existing framework of cognitive processes associated with scientific inquiry described by Chinn and Malhotra (2002). This research provides a systematic analysis of the scientific processes and related reasoning tasks associated with the citizen science project eBird and the corresponding curriculum Classroom BirdWatch . Data consisted of responses to surveys, focus group interviews, document analysis and individual interviews. I suggest that citizen science could be an additional form of classroom-based science inquiry that can promote more authentic features of scientific inquiry and engage students in meaningful ways.

Monitoring results of two PBS demonstration vehicles in the forestry industry in South Africa

CSIR Research Space (South Africa)

Nordengen, Paul A

2010-03-01

Full Text Available and manufactured to comply with the Level 2 safety standards of the Australian PBS system. This paper presents a summary of the monitoring data compiled during the first nine months of operation of the two PBS demonstration vehicles, which were commissioned...

A Reversible Photoacid Functioning in PBS Buffer under Visible Light.

Science.gov (United States)

Abeyrathna, Nawodi; Liao, Yi

2015-09-09

A metastable-state photoacid that can reversibly release a proton in PBS buffer (pH = 7.4) under visible light is reported. The design is based on the dual acid-base property and tautomerization of indazole. The quantum yield was as high as 0.73, and moderate light intensity (10(2) μmol·m(2)·s(-1)) is sufficient for the photoreaction. Reversible pH change of 1.7 units was demonstrated using a 0.1 mM aqueous solution. This type of photoacid is promising for control of proton-transfer processes in physiological conditions and may find applications in biomedical areas.

Virtual Mockup test based on computational science and engineering. Near future technology projected by JSPS-RFTFADVENTURE project

International Nuclear Information System (INIS)

Yoshimura, Shinobu

2001-01-01

The ADVENTURE project began on August, 1997, as a project in the computational science' field of JSPS-RFTFADVENTURE project, and is progressed as five year project. In this project, by using versatile parallel computer environment such as PC cluster, super parallel computer, and so on , to solve an arbitrary shape of actual dynamical equation by using 10 to 100 million freedom class mode under maintaining a general use analytical capacity agreeable with present general use computational mechanics system, further development of a large-scale parallel computational mechanics system (ADVENTURE system) capable of carrying out an optimization design on shapes, physical properties, loading conditions, and so on is performed. Here was scoped, after outlining on background of R and D on ADVENTURE system and its features, on near future virtual mockup test forecast from it. (G.K.)

Inquiry-Based Integrated Science Education: Implementation of Local Content “Soil Washing” Project To Improve Junior High School Students’ Environmental Literacy

Science.gov (United States)

Syifahayu

2017-02-01

The study was conducted based on teaching and learning problems led by conventional method that had been done in the process of learning science. It gave students lack opportunities to develop their competence and thinking skills. Consequently, the process of learning science was neglected. Students did not have opportunity to improve their critical attitude and creative thinking skills. To cope this problem, the study was conducted using Project-Based Learning model through inquiry-based science education about environment. The study also used an approach called Sains Lingkungan and Teknologi masyarakat - “Saling Temas” (Environmental science and Technology in Society) which promoted the local content in Lampung as a theme in integrated science teaching and learning. The study was a quasi-experimental with pretest-posttest control group design. Initially, the subjects were given a pre-test. The experimental group was given inquiry learning method while the control group was given conventional learning. After the learning process, the subjects of both groups were given post-test. Quantitative analysis was performed using the Mann-Whitney U-test and also a qualitative descriptive. Based on the result, environmental literacy skills of students who get inquiry learning strategy, with project-based learning model on the theme soil washing, showed significant differences. The experimental group is better than the control group. Data analysis showed the p-value or sig. (2-tailed) is 0.000 <α = 0.05 with the average N-gain of experimental group is 34.72 and control group is 16.40. Besides, the learning process becomes more meaningful.

Tohoku Women's Hurdling Project: Science Angels (abstract)

Science.gov (United States)

Mizuki, Kotoe; Watanabe, Mayuko

2009-04-01

Tohoku University was the first National University to admit three women students in Japan in 1913. To support the university's traditional ``open-door'' policy, various projects have been promoted throughout the university since its foundation. A government plan, the Third-Stage Basic Plan for Science and Technology, aims to increase the women scientist ratio up to 25% nationwide. In order to achieve this goal, the Tohoku Women's Hurdling Project, funded by the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT), was adopted in 2006. This project is threefold: support for child/family, improvement of facilities, and support for the next generation, which includes our Science Angels program. ``Science Angels'' are women PhD students appointed by the university president, with the mission to form a strong support system among each other and to become role-models to inspire younger students who want to become researchers. Currently, 50 women graduate students of the natural sciences are Science Angels and are encouraged to design and deliver lectures in their areas of specialty at their alma maters. Up to now, 12 lectures have been delivered and science events for children in our community have been held-all with great success.

Photoluminescence under high-electric field of PbS quantum dots

Directory of Open Access Journals (Sweden)

B. Ullrich

2012-12-01

Full Text Available The effect of a laterally applied electric field (≤10 kV/cm on the photoluminescence of colloidal PbS quantum dots (diameter of 2.7 nm on glass was studied. The field provoked a blueshift of the emission peak, a reduction of the luminescent intensity, and caused an increase in the full width at half maximum of the emission spectrum. Upon comparison with the photoluminescence of p-type GaAs exhibits the uniqueness of quantum dot based electric emission control with respect to bulk materials.

The Ripple Effect: Exploring How a Joint Science Specialist/TOSA Can Change Classroom Teachers' Instructional Practices through Project-Based Learning

Science.gov (United States)

Gradias, Jean

In 2013, California became one of the first states to adopt the rigorous Next Generation Science Standards (NGSS). However, the current state of science instruction does not support the conceptual shifts of the NGSS, which call for consistent science instruction K-12, increased inquiry, subject integration, as well as science instruction that connects students to their communities and their world. Therefore, teachers are in need of instructional support for science teaching that can enable them to achieve these higher expectations. This dissertation explored whether implementing a Project-Based Learning (PBL)-centered science specialist changed classroom teachers' frequency of science instruction and use of instructional strategies that support NGSS science delivery. In addition, this study examined how providing a PBL science specialist supported teachers in their comfort with using these more rigorous instructional strategies. Five elementary teachers participated in an action research project conducted over the course of a school year. The frequency with which teachers used the following instructional strategies was analyzed: connecting science to real world phenomena, accessing community resources, integrating science into other subject areas, and using inquiry in science instruction. Quantitative and qualitative data revealed that a PBL science specialist does support classroom teachers in implementing teaching practices aligned to the conceptual shifts implicated by the NGSS; however, individual growth rates varied by instructional strategy. The results of this study provide a foundation for the legitimacy of utilizing a PBL-focused science specialist to support teachers in shifting their instructional practices in order to achieve the Next Generation Science Standards.

Patterns in professional growth of science teachers involved in a team-based PD project

DEFF Research Database (Denmark)

Nielsen, Birgitte Lund

and learning and subsequent discussion of this material. Repeated interviews were analyzed using an adapted version of the interconnected model of teachers’ professional growth. The results show various ways of experimenting with new approaches to be important for three of the teachers while a novice teacher...... the participants refer to. Conclusion is that there are professional growth patterns, especially a pattern involving experimenting, which have a forward-pointing potential to be used to inform school based PD. The results implicate that the same PD project can frame experimenting into practice in various tempi...... and with differentiated facilitation aligned to the individual teacher’s current needs and that external support of science resource teachers can be an integrated part of school based PD....

77 FR 40358 - Federal Management Regulation; FMR Bulletin PBS-2012-03; Redesignations of Federal Buildings...

Science.gov (United States)

2012-07-09

... Management Regulation; FMR Bulletin PBS-2012-03; Redesignations of Federal Buildings: Correction AGENCY: Public Buildings Service (PBS), General Services Administration (GSA). ACTION: Notice of a bulletin..., 2012, a bulletin announcing the designation and redesignation of three Federal buildings. Inadvertently...

Spanish adaptation of the Participatory Behaviors Scale (PBS

Directory of Open Access Journals (Sweden)

Alejandro Magallares

2016-04-01

Full Text Available The aim of this study was to adapt the Participatory Behaviors Scale (PBS and validate the results for use among the Spanish population. Using snowball sampling methodology, 501 individuals from all areas of Spain were selected to participate in the study. The Participatory Behaviors Scale (PBS and questionnaires that measure a sense of community, belief in a just world and Machiavellianism were used to analyze the criterion validity of the adapted scale. A confirmatory factor analysis indicated that the items on the questionnaire fit a second-order model with four factors, which corresponded to the four dimensions proposed by the original authors, namely, disengagement, civil participation, formal political participation and activism. Additionally, it has been found that the scale is related to a sense of community, belief in a just world and Machiavellianism. In light of these results, we concluded that the questionnaire is methodologically valid and can be used by the scientific community to measure participatory behavior.

Science projects in renewable energy and energy efficiency

Energy Technology Data Exchange (ETDEWEB)

1991-07-01

First, the book is written for teachers and other adults who educate children in grades K-12. This allows us to include projects with a variety of levels of difficulty, leaving it to the teacher to adapt them to the appropriate skill level. Second, the book generally focuses on experimental projects that demonstrate the scientific method. We believe that learning the experimental process is most beneficial for students and prepares them for further endeavors in science and for life itself by developing skills in making decisions and solving problems. Although this may appear to limit the book's application to more advanced students and more experienced science teachers, we hope that some of the ideas can be applied to beginning science classes. In addition, we recognize that there are numerous sources of nonexperimental science activities in the field and we hope this book will fill a gap in the available material. Third, we've tried to address the difficulties many teachers face in helping their students get started on science projects. By explaining the process and including extensive suggestions of resources -- both nationally and locally -- we hope to make the science projects more approachable and enjoyable. We hope the book will provide direction for teachers who are new to experimental projects. And finally, in each section of ideas, we've tried to include a broad sampling of projects that cover most of the important concepts related to each technology. Additional topics are listed as one-liners'' following each group of projects.

Preschool Pathways to Science (PrePS[TM]): Facilitating Scientific Ways of Thinking, Talking, Doing, and Understanding

Science.gov (United States)

Gelman, Rochel; Brenneman, Kimberly; Macdonald, Gay; Roman, Moises

2009-01-01

To ensure they're meeting state early learning guidelines for science, preschool educators need fun, age-appropriate, and research-based ways to teach young children about scientific concepts. The basis for the PBS KIDS show "Sid the Science Kid," this teaching resource helps children ages 3-5 investigate their everyday world and develop the…

Ultrafast exciton decay in PbS quantum dots through simultaneous electron and hole recombination with a surface-localized ion pair

Energy Technology Data Exchange (ETDEWEB)

Edme, Kedy; Bettis Homan, Stephanie; Nepomnyashchii, Alexander B.; Weiss, Emily A., E-mail: e-weiss@northwestern.edu

2016-06-01

Highlights: • We synthesize complexes of PbS quantum dots (QDs) and tetracyanoquinodimethane (TCNQ). Each PbS QD spontaneously reduces up to 17 TCNQ molecules. • The photoluminescence of the PbS QDs is quenched in the presence of the reduced TCNQ species through ultrafast non-radiative, simultaneous decay of the electron and hole. • We assign this decay to a four-carrier, concerted charge recombination mechanism with the surface localized sulfur–TCNQ{sup x−} ion pair. - Abstract: This paper describes the ultrafast decay of the band-edge exciton in PbS quantum dots (QDs) through simultaneous recombination of the excitonic hole and electron with the surface localized ion pair formed upon adsorption of tetracyanoquinodimethane (TCNQ). Each PbS QD (R = 1.8 nm) spontaneously reduces up to 17 TCNQ molecules upon adsorption of the TCNQ molecule to a sulfur on the QD surface. The photoluminescence of the PbS QDs is quenched in the presence of the reduced TCNQ species through ultrafast (⩽15-ps) non-radiative decay of the exciton; the rate constant for the decay process increases approximately linearly with the number of adsorbed, reduced TCNQ molecules. Near-infrared and mid-infrared transient absorption show that this decay occurs through simultaneous transfer of the excitonic electron and hole, and is assigned to a four-carrier, concerted charge recombination mechanism based on the observations that (i) the PL of the QDs recovers when spontaneously reduced TCNQ{sup 1−} desorbs from the QD surface upon addition of salt, and (ii) the PL of the QDs is preserved when another spontaneous oxidant, ferrocinium, which cannot participate in charge transfer in its reduced state, is substituted for TCNQ.

The PISCES Project: How Teacher-Scientist Partners can Enhance Elementary Science Instruction

Science.gov (United States)

Reif, C.; Oechel, W.

2003-12-01

The PISCES Project (Partnerships Involving the Scientific Community in Elementary Schools www.sdsa.org/pisces) is an innovative program that brings high quality standards-based elementary science curriculum and hands-on laboratory materials into San Diego County's classrooms. The project is funded by the NSF Graduate Teaching Fellows in K-12 Education (GK-12) program. The project was designed and is administered through cooperation among faculty at San Diego State University and the Science Department of the San Diego County Office of Education. Undergraduate and graduate students enrolled in science programs in San Diego area universities including San Diego State University, California State University San Marcos, and University of California San Diego partner with elementary school teachers. Through this partnership, the scientist brings scientific expertise to the classroom while the teacher delivers the lesson using current pedagogic methods. This is accomplished during a 3 month partnership in which the scientist joins the teacher in the classroom a few days each week to complete professional kit-based curriculum such as that available from FOSS (Full Option Science System) and STC (Science and Technology for Children). The teachers remain in the program for two years during which they have continuous access to the kit-based curriculum as well as two to three partnership cycles. Teachers receive assistance outside of the classroom as well attending professional development institutes three times a year to establish and maintain effective science teaching methods. The San Diego Science Alliance and other community and industry supporters provide the additionalfunding necessary to provide this teacher professional development Currenty, PISCES is present in over 40 schools and is able to provide partnerships to over 100 classrooms each year. In addition to the work done in San Diego, the project has expanded to Barrow, Alaska with plans to expand to La Paz

Genetic analysis of the genus Diospyros ssp. using RAPD and i-PBS methods

Directory of Open Access Journals (Sweden)

Jana Raddová

2012-01-01

Full Text Available Molecular techniques (RAPD and i-PBS were used to study genetic diversity within persimmon collection at Horticulture Faculty of Mendel University in Lednice. The aim of the work was to distinguish 14 known and 6 of unknown origin persimmon cultivars. The basic screening of 20 OPT primers was applied to 4 cultivars differring in the place of origin. Within the group of screened primers there were chosen those, which gave polymorphic repeatable strong and middle strong bands. Selected primers were used for the RAPD reactions within the whole persimmon collection. Three OPA primers previously described in the literature were also used for the RAPD reactions within the whole persimmon collection. Additional 16 i-PBS primers previously described in the literature were also used for i-PBS analysis of the whole group of cultivars. Amplification was successful with 12 i-PBS primers. The FreeTree software package was used to gen­erate a similarity matrix and then to produce a dendrogram using UPGMA analyses. The similarity dendrograms of all persimmon cultivars were created based on both approaches and also on combination of both analyses by program Tree View. All the dendrograms clearly separated the assessed cultivars into 4 clusters. There are cluster of American persimmons – Meader’ (1, ’Garretson’ (2 and ’Early Golden’ (3. They are representatives of D. virginiana. Further part of dendrogram includes single D. lotus (5, which is also clearly separated from other cultivars of the genus Diospyros. The third cluster includes interspecific hybrids ’Rossiyanka’ (10 and ’Nikitskaiya Bordovaiya’ (13, which arised from crosses of D. virginiana and D. kaki. The last cluster is formed by cultivars of Japanese persimmon – ’Mikatani Gosho’, ’Zenjimaru’, ’Tone Wase’, ’Hiratanenashi’, ’Fuyu’, Chinese cultivar – ’Sansi’ and two Italian cultivars ’Vaniglia’ and ’Tipo’. They are clustered without significant

Life sciences space biology project planning

Science.gov (United States)

Primeaux, G.; Newkirk, K.; Miller, L.; Lewis, G.; Michaud, R.

1988-01-01

The Life Sciences Space Biology (LSSB) research will explore the effect of microgravity on humans, including the physiological, clinical, and sociological implications of space flight and the readaptations upon return to earth. Physiological anomalies from past U.S. space flights will be used in planning the LSSB project.The planning effort integrates science and engineering. Other goals of the LSSB project include the provision of macroscopic view of the earth's biosphere, and the development of spinoff technology for application on earth.

Science operations management. [with Infrared Astronomy Satellite project

Science.gov (United States)

Squibb, G. F.

1984-01-01

The operation teams engaged in the IR Astronomical Satellite (IRAS) project included scientists from the IRAS International Science Team. The detailed involvement of these scientists in the design, testing, validation, and operations phases of the IRAS mission contributed to the success of this project. The Project Management Group spent a substantial amount of time discussing science-related issues, because science team coleaders were members from the outset. A single scientific point-of-contact for the Management Group enhanced the depth and continuity of agreement reached in decision-making.

Optical and electrical characterizations of a single step ion beam milling mesa devices of chloride passivated PbS colloidal quantum dots based film

International Nuclear Information System (INIS)

Hechster, Elad; Sarusi, Gabby; Shapiro, Arthur; Lifshitz, Efrat

2016-01-01

Colloidal Quantum Dots (CQDs) are of increasing interest, thanks to their quantum size effect that gives rise to their usage in various applications, such as biological tagging, solar cells and as the sensitizing layer of night vision devices. Here, we analyze the optical absorbance of chloride passivated PbS CQDs as well as revealing a correlation between their photoluminescence and sizes distribution, using theoretical models and experimental results from the literature. Next, we calculate the CQDs resistivity as a film. Although resistivity can be calculated from sheet resistance measurement using four point probes, such measurement is usually carried-out on the layer’s surface that in most cases has dangling bonds and surface states, which might affect the charges flow and modify the resistivity. Therefore; our approach, which was applied in this work, is to extract the actual resistivity from measurements that are performed along the film’s thickness (z-direction). For this intent, we fabricated gold capped PbS mesas devices using a single step Ion Beam Milling (IBM) process where we milled the gold and the PbS film continually, and then measured the vertical resistance. Knowing the mesas’ dimensions, we calculate the resistivity. To the best of our knowledge, no previous work has extracted, vertically, the resistivity of chloride passivated PbS CQDs using the above method.

Optical and electrical characterizations of a single step ion beam milling mesa devices of chloride passivated PbS colloidal quantum dots based film

Energy Technology Data Exchange (ETDEWEB)

Hechster, Elad, E-mail: elad.hechster@gmail.com; Sarusi, Gabby [Electro-Optics Engineering Unit and Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva, 84100 Israel (Israel); Shapiro, Arthur; Lifshitz, Efrat [Schulich Faculty of Chemistry, Solid State Institute, Russel Berrie Nanotechnology Institute, Technion – Israel Institute of technology, 32000 Haifa (Israel)

2016-07-15

Colloidal Quantum Dots (CQDs) are of increasing interest, thanks to their quantum size effect that gives rise to their usage in various applications, such as biological tagging, solar cells and as the sensitizing layer of night vision devices. Here, we analyze the optical absorbance of chloride passivated PbS CQDs as well as revealing a correlation between their photoluminescence and sizes distribution, using theoretical models and experimental results from the literature. Next, we calculate the CQDs resistivity as a film. Although resistivity can be calculated from sheet resistance measurement using four point probes, such measurement is usually carried-out on the layer’s surface that in most cases has dangling bonds and surface states, which might affect the charges flow and modify the resistivity. Therefore; our approach, which was applied in this work, is to extract the actual resistivity from measurements that are performed along the film’s thickness (z-direction). For this intent, we fabricated gold capped PbS mesas devices using a single step Ion Beam Milling (IBM) process where we milled the gold and the PbS film continually, and then measured the vertical resistance. Knowing the mesas’ dimensions, we calculate the resistivity. To the best of our knowledge, no previous work has extracted, vertically, the resistivity of chloride passivated PbS CQDs using the above method.

[The role of science in policy making--EuSANH-ISA project, framework for science advice for health].

Science.gov (United States)

Cianciara, Dorota; Piotrowicz, Maria; Bielska-Lasota, Magdalena; Wysocki, Mirosław J

2012-01-01

Governments and other authorities (including MPs) should be well informed on issues of science and technology. This is particularly important in the era of evidence-based practice. This implies the need to get expert advice. The process by which scientific knowledge is transmitted, along with proposals how to solve the problem, is called science advice. The main aim of the article is to discuss the issue of science advice--definitions, interaction between science and policymaking, and its position in contemporary policies. The second aim is to present European Science Advisory Network for Health (EuSANH), EuSANH-ISA project, and framework for science advice for health which was developed by participants. Furthermore, the role of civil society in decision-making process and science advice is also discussed. Interaction between scientists and policy-makers are described in terms of science-push approach (technocratic model), policy-pull (decisionistic) and simultaneous push-pull approach (pragmatic). The position of science advice is described in historical perspective from the 50s, especially in the last two decades. Description relies to USA, Canada and UK. Principles of scientific advice to government (Government Office for Science, UK) are quoted. Some important documents related to science advice in EU and UN are mentioned. EuSANH network is described as well as EuSANH-ISA project, with its objectives and outcomes. According to findings of this project, the process of science advice for health should follow some steps: framing the issue to be covered; planning entire process leading to the conclusion; drafting the report; reviewing the report and revision; publishing report and assessing the impact on policy.

Assessing Motivations and Use of Online Citizen Science Astronomy Projects

Science.gov (United States)

Nona Bakerman, Maya; Buxner, Sanlyn; Bracey, Georgia; Gugliucci, Nicole

2018-01-01

The exponential proliferation of astronomy data has resulted in the need to develop new ways to analyze data. Recent efforts to engage the public in the discussion of the importance of science has led to projects that are aimed at letting them have hands-on experiences. Citizen science in astronomy, which has followed the model of citizen science in other scientific fields, has increased in the number and type of projects in the last few years and poses captivating ways to engage the public in science.The primary feature of this study was citizen science users’ motivations and activities related to engaging in astronomy citizen science projects. We report on participants’ interview responses related to their motivations, length and frequency of engagement, and reasons for leaving the project. From May to October 2014, 32 adults were interviewed to assess their motivations and experiences with citizen science. In particular, we looked at if and how motivations have changed for those who have engaged in the projects in order to develop support for and understandparticipants of citizen science. The predominant reasons participants took part in citizen science were: interest, helping, learning or teaching, and being part of science. Everyone interviewed demonstrated an intrinsic motivation to do citizen science projects.Participants’ reasons for ending their engagement on any given day were: having to do other things, physical effects of the computer, scheduled event that ended, attention span or tired, computer or program issues. A small fraction of the participants also indicated experiencing negative feedback. Out of the participants who no longer took part in citizen science projects, some indicated that receiving negative feedback was their primary reason and others reported the program to be frustrating.Our work is helping us to understand participants who engage in online citizen science projects so that researchers can better design projects to meet their

4-H Textile Science Beginner Projects.

Science.gov (United States)

Scholl, Jan

This packet contains three 4-H projects for students beginning the sewing sequence of the textile sciences area. The projects cover basics of sewing using sewing machines, more difficult sewing machine techniques, and hand sewing. Each project provides an overview of what the student will learn, what materials are needed, and suggested projects…

Overview of NASA Finesse (Field Investigations to Enable Solar System Science and Exploration) Science and Exploration Project

Science.gov (United States)

Heldmann, J. L.; Lim, D.S.S.; Hughes, S.; Nawotniak, S. Kobs; Garry, B.; Sears, D.; Neish, C.; Osinski, G. R.; Hodges, K.; Downs, M.;

Managing a big ground-based astronomy project: the Thirty Meter Telescope (TMT) project

Science.gov (United States)

Sanders, Gary H.

2008-07-01

TMT is a big science project and its scale is greater than previous ground-based optical/infrared telescope projects. This paper will describe the ideal "linear" project and how the TMT project departs from that ideal. The paper will describe the needed adaptations to successfully manage real world complexities. The progression from science requirements to a reference design, the development of a product-oriented Work Breakdown Structure (WBS) and an organization that parallels the WBS, the implementation of system engineering, requirements definition and the progression through Conceptual Design to Preliminary Design will be summarized. The development of a detailed cost estimate structured by the WBS, and the methodology of risk analysis to estimate contingency fund requirements will be summarized. Designing the project schedule defines the construction plan and, together with the cost model, provides the basis for executing the project guided by an earned value performance measurement system.

Joint Science Education Project: Learning about polar science in Greenland

Science.gov (United States)

Foshee Reed, Lynn

2014-05-01

The Joint Science Education Project (JSEP) is a successful summer science and culture opportunity in which students and teachers from the United States, Denmark, and Greenland come together to learn about the research conducted in Greenland and the logistics involved in supporting the research. They conduct experiments first-hand and participate in inquiry-based educational activities alongside scientists and graduate students at a variety of locations in and around Kangerlussuaq, Greenland, and on the top of the ice sheet at Summit Station. The Joint Committee, a high-level forum involving the Greenlandic, Danish and U.S. governments, established the Joint Science Education Project in 2007, as a collaborative diplomatic effort during the International Polar Year to: • Educate and inspire the next generation of polar scientists; • Build strong networks of students and teachers among the three countries; and • Provide an opportunity to practice language and communication skills Since its inception, JSEP has had 82 student and 22 teacher participants and has involved numerous scientists and field researchers. The JSEP format has evolved over the years into its current state, which consists of two field-based subprograms on site in Greenland: the Greenland-led Kangerlussuaq Science Field School and the U.S.-led Arctic Science Education Week. All travel, transportation, accommodations, and meals are provided to the participants at no cost. During the 2013 Kangerlussuaq Science Field School, students and teachers gathered data in a biodiversity study, created and set geo- and EarthCaches, calculated glacial discharge at a melt-water stream and river, examined microbes and tested for chemical differences in a variety of lakes, measured ablation at the edge of the Greenland Ice Sheet, and learned about fossils, plants, animals, minerals and rocks of Greenland. In addition, the students planned and led cultural nights, sharing food, games, stories, and traditions of

A Community-University Exchange Project Modeled after Europe's Science Shops

Science.gov (United States)

Tryon, Elizabeth; Ross, J. Ashleigh

2012-01-01

This article describes a pilot project of the Morgridge Center for Public Service at the University of Wisconsin-Madison for a new structure for community-based learning and research. It is based on the European-derived science shop model for democratizing campus-community partnerships using shared values of mutual respect and validation of…

Investigating the Quality of Project-Based Science and Technology Learning Environments in Elementary School: A Critical Review of Instruments

Science.gov (United States)

Thys, Miranda; Verschaffel, Lieven; Van Dooren, Wim; Laevers, Ferre

2016-01-01

This paper provides a systematic review of instruments that have the potential to measure the quality of project-based science and technology (S&T) learning environments in elementary school. To this end, a comprehensive literature search was undertaken for the large field of S&T learning environments. We conducted a horizontal bottom-up…

PbS Thin Films for Photovoltaic Applications Obtained by Non-Traditional Chemical Bath Deposition

Directory of Open Access Journals (Sweden)

Pérez-García Claudia Elena

2015-01-01

Full Text Available To optimize cost-efficiency relation for thin film solar cells, we explore the recently developed versions of chemical deposition of semiconductor films, together with classic CBD (Chemical Bath Deposition: SILAR (Successive Ionic Layer Adsorption and Reaction and PCBD (Photo Chemical Bath Deposition, all of them ammonia-free and ecologically friendly. The films of CdS and PbS were made, and experimental solar cells with CdS window layer and PbS absorber elaborated. We found that band gap of PbS films can be monitored by deposition process due to porosity-induced quantum confinement which depends on the parameters of the process. We expect that the techniques employed can be successfully used for production of optoelectronic devices.

Succesful Experience of the Project "ASTROTOP" in Israel: Space-astonomy Science education in form of independent reserch projects of pupils

Science.gov (United States)

Pustil'Nik, Lev

We present more then 10 year experience of educational project in Space/Astrophysics/Environment field, realized on the base of National Science- Educational Center "Blossoms of Science" of the Jordan Valley College. Our approach is based on the natural curiosity of children as driver of their self-development from the first minutes of their life and even in adult state. This approach shift center of the weight in educational process from direct lectures, sermons, explanation from teacher to children on own attempts of children to investigate problem, what is interesting for them, by themselves (individually or in group). Our approach includes four levels of the projects: "nano-projects" for children garden and basic school (up to 10-12 years), "micro-projects" for intermediate school (12-16 years), "mini-projects" for high school (16-18 years), and "macro-projects" for the best graduates high schools and students of colleges (17-22 years). These levels and projects are interconnected one with another and sometimes participants, started on the micro-projects level in intermediate school, continue their activity up to macro-projects of the graduate's diploma level. For each level we organize courses for preparation of the teachers and instructors, interested in the using of our receipts, and published books and brochures for them. The content of our activity for different levels: a) Level of kinder gardens/basic schools- special software with interactive movie -nano-projects; b) Level of intermediate school: "Days of Science" in tens schools of Israel- first contact with astronomy; c) Summer astronomy camps (4-5 of one week camps on 200-300 pupils from all country) with introduce to astronomy and with preparation of micro-projects on themes - first successful experience of research in real science fields (hundreds projects); d) ASTROTOP - one year program of preparation of short projects, with solution on the quality level of chosen astrophysical problem - mini-projects

2 W high efficiency PbS mid-infrared surface emitting laser

Science.gov (United States)

Ishida, A.; Sugiyama, Y.; Isaji, Y.; Kodama, K.; Takano, Y.; Sakata, H.; Rahim, M.; Khiar, A.; Fill, M.; Felder, F.; Zogg, H.

2011-09-01

High efficiency laser operation with output power exceeding 2 W was obtained for vertical external-cavity PbS based IV-VI compound surface emitting quantum-well structures. The laser showed external quantum efficiency as high as 16%. Generally, mid-infrared III-V or II-VI semiconductor laser operation utilizing interband electron transitions are restricted by Auger recombination and free carrier absorption. Auger recombination is much lower in the IV-VI semiconductors, and the free-carrier absorption is significantly reduced by an optically pumped laser structure including multi-step optical excitation layers.

The LOFAR Magnetism Key Science Project

NARCIS (Netherlands)

Anderson, James; Beck, Rainer; Bell, Michael; de Bruyn, Ger; Chyzy, Krzysztof; Eislöffel, Jochen; Enßlin, Torsten; Fletcher, Andrew; Haverkorn, Marijke; Heald, George; Horneffer, Andreas; Noutsos, Aris; Reich, Wolfgang; Scaife, Anna; the LOFAR collaboration, [No Value

2012-01-01

Measuring radio waves at low frequencies offers a new window to study cosmic magnetism, and LOFAR is the ideal radio telescope to open this window widely. The LOFAR Magnetism Key Science Project (MKSP) draws together expertise from multiple fields of magnetism science and intends to use LOFAR to

Earth Science Capability Demonstration Project

Science.gov (United States)

Cobleigh, Brent

2006-01-01

A viewgraph presentation reviewing the Earth Science Capability Demonstration Project is shown. The contents include: 1) ESCD Project; 2) Available Flight Assets; 3) Ikhana Procurement; 4) GCS Layout; 5) Baseline Predator B Architecture; 6) Ikhana Architecture; 7) UAV Capability Assessment; 8) The Big Picture; 9) NASA/NOAA UAV Demo (5/05 to 9/05); 10) NASA/USFS Western States Fire Mission (8/06); and 11) Suborbital Telepresence.

Special Project Examination in Integrated Science - Ordinary Level.

Science.gov (United States)

Wimpenny, David

A science achievement test for the General Certificate of Education (GCE, England) was developed for students enrolled in the curriculum of the Schools Council Integrated Science Project. This document contains discussions of the testing program and a copy of the 1973 test. After an overview of the curriculum project and issues related to…

Water Integration Project Science Strategies White Paper

International Nuclear Information System (INIS)

Alan K. Yonk

2003-01-01

This white paper has been prepared to document the approach to develop strategies to address Idaho National Engineering and Environmental Laboratory (INEEL) science and technology needs/uncertainties to support completion of INEEL Idaho Completion Project (Environmental Management [EM]) projects against the 2012 plan. Important Idaho Completion Project remediation and clean-up projects include the 2008 OU 10-08 Record of Decision, completion of EM by 2012, Idaho Nuclear Technology and Engineering Center Tanks, INEEL CERCLA Disposal Facility, and the Radioactive Waste Management Complex. The objective of this effort was to develop prioritized operational needs and uncertainties that would assist Operations in remediation and clean-up efforts at the INEEL and develop a proposed path forward for the development of science strategies to address these prioritized needs. Fifteen needs/uncertainties were selected to develop an initial approach to science strategies. For each of the 15 needs/uncertainties, a detailed definition was developed. This included extracting information from the past interviews with Operations personnel to provide a detailed description of the need/uncertainty. For each of the 15 prioritized research and development needs, a search was performed to identify the state of the associated knowledge. The knowledge search was performed primarily evaluating ongoing research. The ongoing research reviewed included Environmental Systems Research Analysis, Environmental Management Science Program, Laboratory Directed Research and Development, Inland Northwest Research Alliance, United States Geological Survey, and ongoing Operations supported projects. Results of the knowledge search are documented as part of this document

Water Integration Project Science Strategies White Paper

Energy Technology Data Exchange (ETDEWEB)

Alan K. Yonk

2003-09-01

This white paper has been prepared to document the approach to develop strategies to address Idaho National Engineering and Environmental Laboratory (INEEL) science and technology needs/uncertainties to support completion of INEEL Idaho Completion Project (Environmental Management [EM]) projects against the 2012 plan. Important Idaho Completion Project remediation and clean-up projects include the 2008 OU 10-08 Record of Decision, completion of EM by 2012, Idaho Nuclear Technology and Engineering Center Tanks, INEEL CERCLA Disposal Facility, and the Radioactive Waste Management Complex. The objective of this effort was to develop prioritized operational needs and uncertainties that would assist Operations in remediation and clean-up efforts at the INEEL and develop a proposed path forward for the development of science strategies to address these prioritized needs. Fifteen needs/uncertainties were selected to develop an initial approach to science strategies. For each of the 15 needs/uncertainties, a detailed definition was developed. This included extracting information from the past interviews with Operations personnel to provide a detailed description of the need/uncertainty. For each of the 15 prioritized research and development needs, a search was performed to identify the state of the associated knowledge. The knowledge search was performed primarily evaluating ongoing research. The ongoing research reviewed included Environmental Systems Research Analysis, Environmental Management Science Program, Laboratory Directed Research and Development, Inland Northwest Research Alliance, United States Geological Survey, and ongoing Operations supported projects. Results of the knowledge search are documented as part of this document.

Effects of Hydroxylation on PbS Quantum Dot Sensitized TiO2 Nanotube Array Photoelectrodes

International Nuclear Information System (INIS)

Liu, Zhongqing; Wang, Bin; Wu, Jianchun; Dong, Qiang; Zhang, Xiaoming; Xu, He

2016-01-01

ABSTRACT: The contact state at the heterojunction interfaces greatly influences the interfacial kinetics of the photoinduced charge carriers. In this study, we used a facile NaOH pretreatment to replenish the hydroxyl groups lost during the heat treatment for crystallization of TiO 2 nanotube arrays (TNAs) prepared via anodic oxidization. By reacting the carboxylic acid groups of thioglycolic acid (TGA) with the TiO 2 surface hydroxyl groups, TGA molecules were covalently linked to the TiO 2 surface and then PbS quantum dots (QDs) were anchored onto the TNAs via the successive ionic layer adsorption and reaction (SILAR) method. The sample microstructure and photoelectrochemical properties were analyzed with X-ray diffraction (XRD), transmission electron microscopy (TEM), field-emission scanning electron microscopy (FE-SEM),current–voltage characteristics (J–V), electrochemical impedance spectroscopy (EIS), transient photovoltage plots and Mott-Schottky curves. The contact state and electrostatic potential distribution between TiO 2 {1 0 1} and PbS {1 1 1} planes were estimated by using first principle simulation. It was found that the NaOH pretreatment could enhance the crystallization degree of PbS QDs, decrease the crystal face mismatch, dangling bond density and the interfacial resistance between PbS QDs and TiO 2 , and accelerate the interfacial separation and transfer of photoinduced charge carriers. The first principle calculations demonstrated that the PbS QDs and TiO 2 interfacial contact was strengthened, and the built-in electric field was induced from TiO 2 {1 0 1} towards PbS {1 1 1}. These combined effects apparently improved the device photoelectrochemical performance. Compared to the sample without pretreatment, the specimen pretreated with NaOH demonstrated 19.96% and 29.93% increases in peak photoconversion efficiency after five and ten cycles of SILAR deposition, respectively.

Facile preparation of PbS nanostructures and PbS/f-CNT nanocomposites using xanthate as sulfur source: Thermal and optical characterization

Energy Technology Data Exchange (ETDEWEB)

Golabi, Parisa; Akbarzadeh, Raziyeh; Dehghani, Hossein, E-mail: dehghani@kashanu.ac.ir

2015-10-25

PbS nanostructures with different morphologies were fabricated using a new sulfur source through a facile and low cost hydro(solvo)thermal method. The influence of different reaction factors such as sulfur source, temperature, reactant, solvent and surfactant on the size and morphology of the obtained PbS particles were investigated. Beside, a simple hydrothermal process at low temperature (60 °C) for little time (4 h), has been used for preparation of PbS nanoparticles (NPs)/functionalized multi wall carbon nanotubes (f-MWCNTs) nanocomposite. The as-prepared nanocomposite possesses excellent thermal and optical properties. Thermal stability increases by depositing PbS nanoparticles on the surface of CNT. The structure, morphology, thermal and optical properties of the as-prepared nanocompounds were studied by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, Scanning electron microscope (SEM), Energy-dispersive X-ray spectroscopy, Thermogravimetric analysis (TGA), Pl spectra and UV–Vis absorption spectra. Photoluminescence spectra of PbS NPs and nanocomposite are consist of two emission peaks which centered at around 402 and 423 nm, when excited at 350 nm. It was noteworthy that the blue luminescence intensity over PbS/f-CNT nanocomposite is very lower than that of pure PbS NPs. Remarkable blue-shift from bulk material was observed on the PbS nanoparticles using UV–Vis spectrum. Furthermore, possible growth mechanism of PbS nanostructures is presented. - Graphical abstract: PbS nanostructures with different morphologies were fabricated using xanthate as sulfide source. Also, PbS/f-CNT nanocomposites were synthesized by simple hydrothermal process at low temperature (60 °C) for little time (4 h). - Highlights: • Sodium tert-butyl xanthate was used as sulfur source for synthesis of PbS. • Pb(CH{sub 3}COO){sub 2}·3H{sub 2}O salt was used for synthesis of PbS. • PbS/CNT nanocomposite was synthesized in deionized water for 4 h at 60

Elementary and middle school science improvement project

Science.gov (United States)

Mcguire, Saundra Y.

1989-01-01

The Alabama A and M University Elementary and Middle School Science Improvement Project (Project SIP) was instituted to improve the science knowledge of elementary and middle school teachers using the experimental or hands-on approach. Summer workshops were conducted during the summers of 1986, 1987, and 1988 in the areas of biology, chemistry, physics, and electricity, and magnetism. Additionally, a manual containing 43 lessons which included background information, experiments and activities for classroom and home use was provided to each teacher. During the course of the project activities, the teachers interacted with various university faculty members, scientists, and NASA staff. The administrative aspects of the program, the delivery of the services to participating teachers, and the project outcome are addressed.

The Aeolus project: Science outreach through art.

Science.gov (United States)

Drumm, Ian A; Belantara, Amanda; Dorney, Steve; Waters, Timothy P; Peris, Eulalia

2015-04-01

With a general decline in people's choosing to pursue science and engineering degrees there has never been a greater need to raise the awareness of lesser known fields such as acoustics. Given this context, a large-scale public engagement project, the 'Aeolus project', was created to raise awareness of acoustics science through a major collaboration between an acclaimed artist and acoustics researchers. It centred on touring the large singing sculpture Aeolus during 2011/12, though the project also included an extensive outreach programme of talks, exhibitions, community workshops and resources for schools. Described here are the motivations behind the project and the artwork itself, the ways in which scientists and an artist collaborated, and the public engagement activities designed as part of the project. Evaluation results suggest that the project achieved its goal of inspiring interest in the discipline of acoustics through the exploration of an other-worldly work of art. © The Author(s) 2013.

Progress of JAERI neutron science project

International Nuclear Information System (INIS)

Oyama, Yukio

1999-01-01

Neutron Science Project was started at Japan Atomic Energy Research Institute since 1996 for promoting futuristic basic science and nuclear technology utilizing neutrons. For this purpose, research and developments of intense proton accelerator and spallation neutron target were initiated. The present paper describes the current status of such research and developments. (author)

Vanderbilt University Institute of Imaging Science Center for Computational Imaging XNAT: A multimodal data archive and processing environment.

Science.gov (United States)

Harrigan, Robert L; Yvernault, Benjamin C; Boyd, Brian D; Damon, Stephen M; Gibney, Kyla David; Conrad, Benjamin N; Phillips, Nicholas S; Rogers, Baxter P; Gao, Yurui; Landman, Bennett A

2016-01-01

The Vanderbilt University Institute for Imaging Science (VUIIS) Center for Computational Imaging (CCI) has developed a database built on XNAT housing over a quarter of a million scans. The database provides framework for (1) rapid prototyping, (2) large scale batch processing of images and (3) scalable project management. The system uses the web-based interfaces of XNAT and REDCap to allow for graphical interaction. A python middleware layer, the Distributed Automation for XNAT (DAX) package, distributes computation across the Vanderbilt Advanced Computing Center for Research and Education high performance computing center. All software are made available in open source for use in combining portable batch scripting (PBS) grids and XNAT servers. Copyright © 2015 Elsevier Inc. All rights reserved.

Tunneling effect on double potential barriers GaAs and PbS

Science.gov (United States)

Prastowo, S. H. B.; Supriadi, B.; Ridlo, Z. R.; Prihandono, T.

2018-04-01

A simple model of transport phenomenon tunnelling effect through double barrier structure was developed. In this research we concentrate on the variation of electron energy which entering double potential barriers to transmission coefficient. The barriers using semiconductor materials GaAs (Galium Arsenide) with band-gap energy 1.424 eV, distance of lattice 0.565 nm, and PbS (Lead Sulphide) with band gap energy 0.41 eV distance of lattice is 18 nm. The Analysisof tunnelling effect on double potentials GaAs and PbS using Schrodinger’s equation, continuity, and matrix propagation to get transmission coefficient. The maximum energy of electron that we use is 1.0 eV, and observable from 0.0025 eV- 1.0 eV. The shows the highest transmission coefficient is0.9982 from electron energy 0.5123eV means electron can pass the barriers with probability 99.82%. Semiconductor from materials GaAs and PbS is one of selected material to design semiconductor device because of transmission coefficient directly proportional to bias the voltage of semiconductor device. Application of the theoretical analysis of resonant tunnelling effect on double barriers was used to design and develop new structure and combination of materials for semiconductor device (diode, transistor, and integrated circuit).

Museums for Science Education: can we make the difference? The case of the EST project

Directory of Open Access Journals (Sweden)

Maria Xanthoudaki

2007-06-01

Full Text Available This paper addresses the role of museums in education in science and technology through the discussion of a specific project entitled EST “Educate in Science and Technology”. The Project puts together methodologies and activities through which museums can be used as resources for long-term project work. In-service training for teachers, work in class with learning kits or with materials brought in by a Science Van, and visits to the museum are planned and developed jointly by museum experts and teachers. The Project proposes a teaching and learning model which sees the museum experience as central and integral part of a teaching and learning process with more effective outcomes. The analysis of the Project activities and methodologies is based on the work carried out at the National Museum of Science and Technology Leonardo da Vinci, which perceives the learner (the visitor at the heart of its educational methodologies and provision.

B1-B2 phase transition mechanism and pathway of PbS under pressure

Science.gov (United States)

Adeleke, Adebayo A.; Yao, Yansun

2018-03-01

Experimental studies at finite Pressure-Temperature (P-T) conditions and a theoretical study at 0 K of the phase transition in lead sulphide (PbS) have been inconclusive. Many studies that have been done to understand structural transformation in PbS can broadly be classified into two main ideological streams—one with Pnma and another with Cmcm orthorhombic intermediate phase. To foster better understanding of this phenomenon, we present the result of the first-principles study of phase transition in PbS at finite temperature. We employed the particle swarm-intelligence optimization algorithm for the 0 K structure search and first-principles metadynamics simulations to study the phase transition pathway of PbS from the ambient pressure, 0 K Fm-3m structure to the high-pressure Pm-3m phase under experimentally achievable P-T conditions. Significantly, our calculation shows that both streams are achievable under specific P-T conditions. We further uncover new tetragonal and monoclinic structures of PbS with space group P21/c and I41/amd, respectively. We propose the P21/c and I41/amd as a precursor phase to the Pnma and Cmcm phases, respectively. We investigated the stability of the new structures and found them to be dynamically stable at their stability pressure range. Electronic structure calculations reveal that both P21/c and I41/amd phases are semiconducting with direct and indirect bandgap energies of 0.69(5) eV and 0.97(3) eV, respectively. In general, both P21/c and I41/amd phases were found to be energetically competitive with their respective orthorhombic successors.

Deposition of Cu-doped PbS thin films with low resistivity using DC sputtering

Science.gov (United States)

Soetedjo, Hariyadi; Siswanto, Bambang; Aziz, Ihwanul; Sudjatmoko

2018-03-01

Investigation of the electrical resistivity of Cu-doped PbS thin films has been carried out. The films were prepared using a DC sputtering technique. The doping was achieved by introducing the Cu dopant plate material directly on the surface of the PbS sputtering target plate. SEM-EDX data shows the Cu concentration in the PbS film to be proportional to the Cu plate diameter. The XRD pattern indicates the film is in crystalline cubic form. The Hall effect measurement shows that Cu doping yields an increase in the carrier concentration to 3.55 × 1019 cm-3 and a significant decrease in electrical resistivity. The lowest resistivity obtained was 0.13 Ωcm for a Cu concentration of 18.5%. Preferential orientation of (1 1 1) and (2 0 0) occurs during deposition.

Modification of Morphological, Structural and Optical Properties of CBD-Based Growth of PbS Films on Glass Substrates by Addition of Saccharin

Directory of Open Access Journals (Sweden)

Yasin YÜCEL

2018-03-01

Full Text Available Saccharin which so-called as benzoic sulfimide is an artificial sweetener. In this paper, nanostructured lead sulfide (PbS thin films were produced in the presence of additive known as saccharin via chemical bath deposition (CBD. Effect of the saccharin content on the morphological, optical and structural properties of the films has been investigated. Lead sulfide (PbS films that included additive were prepared at five different concentrations of saccharin (from 0 to 5%. The fabricated samples were characterized by surface roughness, scanning electron microscopy (SEM, X-Ray diffraction and UV-vis spectroscopy. It was found that the presence of saccharin highly affected the optical and structural properties of PbS thin films. According to the X-Ray diffraction results, crystallite size values of the films decreased from 12.88 to 5.25 nm with increasing of saccharin content. UV-vis measurements showed that both the band gap and transmission properties of the films increased as a result of increasing saccharin concentration. Further, Surface roughness measurements exhibited that average surface roughness was diminished with increasing saccharin content. As a result, it has been found that the presence of saccharin in growth solution played a significant mission in adjusting the main physical properties of the samples.

Development of a science project based on the use of several intelligences

Directory of Open Access Journals (Sweden)

Gallegos Reséndiz, Cut

2013-01-01

Full Text Available Solve and create problems are characteristic of an intelligent and creative mind. From a practical sense, intelligence procedures and leads to correct results but creativity allow us to innovate on procedures, interpretation of results and generated products. This project combines science and art, aiming to promote intelligence and creativity in students in the second grade of primary school. The work is part of the study of general aspects of the biology of insects in various learning environments. The results indicate a process of understanding the basic structures of insects, the biological sense of communication sounds and movements of the basic elements of music making, of how an orchestra is organized and a dance and especially the resolution of problems related to science and art.

Learning Styles of Science and Engineering Students in Problem and Project Based Education

DEFF Research Database (Denmark)

Kolmos, Anette; Holgaard, Jette Egelund

2008-01-01

At the Faculty of Engineering and Science at Aalborg University, Denmark, process skills are an integrated part of the curriculum objectives. During the first year programme, a special course in Collaboration, Learning and Project Management (CLP) is given to develop those skills. In order...... to develop students’ learning and the CLP-course, the Felder-Soloman Index of Learning Styles (ILS®) has been used in that course and data has been collected to investigate whether some learning style preferences are more conspicuous that others in a problem based learning environment. The results show, more...... pronounced than similar studies, that the first year engineering students at Aalborg University are considerable more active than reflective. This results leads to a discussion of whether reflection and conceptualization should be facilitated further in the curriculum to balance the students learning style...

Effective Teaching Methods--Project-based Learning in Physics

Science.gov (United States)

Holubova, Renata

2008-01-01

The paper presents results of the research of new effective teaching methods in physics and science. It is found out that it is necessary to educate pre-service teachers in approaches stressing the importance of the own activity of students, in competences how to create an interdisciplinary project. Project-based physics teaching and learning…

Photoluminescence properties of powder and pulsed laser-deposited PbS nanoparticles in SiO2

International Nuclear Information System (INIS)

Dhlamini, M.S.; Terblans, J.J.; Ntwaeaborwa, O.M.; Ngaruiya, J.M.; Hillie, K.T.; Botha, J.R.; Swart, H.C.

2008-01-01

Thin films of lead sulfide (PbS) nanoparticles embedded in an amorphous silica (SiO 2 ) host were grown on Si(1 0 0) substrates at different temperatures by the pulsed laser deposition (PLD) technique. Surface morphology and photoluminescence (PL) properties of samples were analyzed with scanning electron microscopy (SEM) and a 458 nm Ar + laser, respectively. The PL data show a blue-shift from the normal emission at ∼3200 nm in PbS bulk to ∼560-700 nm in nanoparticulate PbS powders and thin films. Furthermore, the PL emission of the films was red-shifted from that of the powders at ∼560 to ∼660 nm. The blue-shifting of the emission wavelengths from 3200 to ∼560-700 nm is attributed to quantum confinement of charge carriers in the restricted volume of nanoparticles, while the red-shift between powders and thin-film PbS nanoparticles is speculated to be due to an increase in the defect concentration. The red-shift increased slightly with an increase in deposition temperature, which suggests that there has been a relative growth in particle sizes during the PLD of the films at higher temperatures. Generally, the PL emission of the powders was more intense than that of the films, although the intensity of some of the films was improved marginally by post-deposition annealing at 400 deg. C. This paper compares the PL properties of powder and pulsed laser-deposited thin films of PbS nanoparticles and the effects of deposition temperatures

Neutron nuclear physics under the neutron science project

Energy Technology Data Exchange (ETDEWEB)

Chiba, Satoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1997-11-01

The concept of fast neutron physics facility in the Neutron Science Research project is described. This facility makes use of an ultra-short proton pulse (width < 1 ns) for fast neutron time-of-flight works. The current design is based on an assumption of the maximum proton current of 100 {mu}A. Available neutron fluence and energy resolution are explained. Some of the research subjects to be performed at this facility are discussed. (author)

Project Lifescape | Initiatives | Indian Academy of Sciences

Indian Academy of Sciences (India)

This project is part of the Academy initiative to enhance the quality of science education. It is pursued in ... database through a website. Project Lifescape has also initiated work using some Indian languages. ... and Outreach. Math and Finance ...

WE-E-BRB-03: Implementation of PBS Proton Therapy Treatment for Free Breathing Lung Cancer Patients

Energy Technology Data Exchange (ETDEWEB)

Li, H. [UT MD Anderson Cancer Center (United States)

2016-06-15

Strategies for treating thoracic and liver tumors using pencil beam scanning proton therapy Thoracic and liver tumors have not been treated with pencil beam scanning (PBS) proton therapy until recently. This is because of concerns about the significant interplay effects between proton spot scanning and patient’s respiratory motion. However, not all tumors have unacceptable magnitude of motion for PBS proton therapy. Therefore it is important to analyze the motion and understand the significance of the interplay effect for each patient. The factors that affect interplay effect and its washout include magnitude of motion, spot size, spot scanning sequence and speed. Selection of beam angle, scanning direction, repainting and fractionation can all reduce the interplay effect. An overview of respiratory motion management in PBS proton therapy including assessment of tumor motion and WET evaluation will be first presented. As thoracic tumors have very different motion patterns from liver tumors, examples would be provided for both anatomic sites. As thoracic tumors are typically located within highly heterogeneous environments, dose calculation accuracy is a concern for both treatment target and surrounding organs such as spinal cord or esophagus. Strategies for mitigating the interplay effect in PBS will be presented and the pros and cons of various motion mitigation strategies will be discussed. Learning Objectives: Motion analysis for individual patients with respect to interplay effect Interplay effect and mitigation strategies for treating thoracic/liver tumors with PBS Treatment planning margins for PBS The impact of proton dose calculation engines over heterogeneous treatment target and surrounding organs I have a current research funding from Varian Medical System under the master agreement between University of Pennsylvania and Varian; L. Lin, I have a current funding from Varian Medical System under the master agreement between University of Pennsylvania and

WE-E-BRB-02: Implementation of Pencil Beam Scanning (PBS) Proton Therapy Treatment for Liver Patient

Energy Technology Data Exchange (ETDEWEB)

Lin, L. [University of Pennsylvania (United States)

2016-06-15

Strategies for treating thoracic and liver tumors using pencil beam scanning proton therapy Thoracic and liver tumors have not been treated with pencil beam scanning (PBS) proton therapy until recently. This is because of concerns about the significant interplay effects between proton spot scanning and patient’s respiratory motion. However, not all tumors have unacceptable magnitude of motion for PBS proton therapy. Therefore it is important to analyze the motion and understand the significance of the interplay effect for each patient. The factors that affect interplay effect and its washout include magnitude of motion, spot size, spot scanning sequence and speed. Selection of beam angle, scanning direction, repainting and fractionation can all reduce the interplay effect. An overview of respiratory motion management in PBS proton therapy including assessment of tumor motion and WET evaluation will be first presented. As thoracic tumors have very different motion patterns from liver tumors, examples would be provided for both anatomic sites. As thoracic tumors are typically located within highly heterogeneous environments, dose calculation accuracy is a concern for both treatment target and surrounding organs such as spinal cord or esophagus. Strategies for mitigating the interplay effect in PBS will be presented and the pros and cons of various motion mitigation strategies will be discussed. Learning Objectives: Motion analysis for individual patients with respect to interplay effect Interplay effect and mitigation strategies for treating thoracic/liver tumors with PBS Treatment planning margins for PBS The impact of proton dose calculation engines over heterogeneous treatment target and surrounding organs I have a current research funding from Varian Medical System under the master agreement between University of Pennsylvania and Varian; L. Lin, I have a current funding from Varian Medical System under the master agreement between University of Pennsylvania and

WE-E-BRB-03: Implementation of PBS Proton Therapy Treatment for Free Breathing Lung Cancer Patients

International Nuclear Information System (INIS)

Li, H.

2016-01-01

Strategies for treating thoracic and liver tumors using pencil beam scanning proton therapy Thoracic and liver tumors have not been treated with pencil beam scanning (PBS) proton therapy until recently. This is because of concerns about the significant interplay effects between proton spot scanning and patient’s respiratory motion. However, not all tumors have unacceptable magnitude of motion for PBS proton therapy. Therefore it is important to analyze the motion and understand the significance of the interplay effect for each patient. The factors that affect interplay effect and its washout include magnitude of motion, spot size, spot scanning sequence and speed. Selection of beam angle, scanning direction, repainting and fractionation can all reduce the interplay effect. An overview of respiratory motion management in PBS proton therapy including assessment of tumor motion and WET evaluation will be first presented. As thoracic tumors have very different motion patterns from liver tumors, examples would be provided for both anatomic sites. As thoracic tumors are typically located within highly heterogeneous environments, dose calculation accuracy is a concern for both treatment target and surrounding organs such as spinal cord or esophagus. Strategies for mitigating the interplay effect in PBS will be presented and the pros and cons of various motion mitigation strategies will be discussed. Learning Objectives: Motion analysis for individual patients with respect to interplay effect Interplay effect and mitigation strategies for treating thoracic/liver tumors with PBS Treatment planning margins for PBS The impact of proton dose calculation engines over heterogeneous treatment target and surrounding organs I have a current research funding from Varian Medical System under the master agreement between University of Pennsylvania and Varian; L. Lin, I have a current funding from Varian Medical System under the master agreement between University of Pennsylvania and

WE-E-BRB-02: Implementation of Pencil Beam Scanning (PBS) Proton Therapy Treatment for Liver Patient

International Nuclear Information System (INIS)

Lin, L.

2016-01-01

Strategies for treating thoracic and liver tumors using pencil beam scanning proton therapy Thoracic and liver tumors have not been treated with pencil beam scanning (PBS) proton therapy until recently. This is because of concerns about the significant interplay effects between proton spot scanning and patient’s respiratory motion. However, not all tumors have unacceptable magnitude of motion for PBS proton therapy. Therefore it is important to analyze the motion and understand the significance of the interplay effect for each patient. The factors that affect interplay effect and its washout include magnitude of motion, spot size, spot scanning sequence and speed. Selection of beam angle, scanning direction, repainting and fractionation can all reduce the interplay effect. An overview of respiratory motion management in PBS proton therapy including assessment of tumor motion and WET evaluation will be first presented. As thoracic tumors have very different motion patterns from liver tumors, examples would be provided for both anatomic sites. As thoracic tumors are typically located within highly heterogeneous environments, dose calculation accuracy is a concern for both treatment target and surrounding organs such as spinal cord or esophagus. Strategies for mitigating the interplay effect in PBS will be presented and the pros and cons of various motion mitigation strategies will be discussed. Learning Objectives: Motion analysis for individual patients with respect to interplay effect Interplay effect and mitigation strategies for treating thoracic/liver tumors with PBS Treatment planning margins for PBS The impact of proton dose calculation engines over heterogeneous treatment target and surrounding organs I have a current research funding from Varian Medical System under the master agreement between University of Pennsylvania and Varian; L. Lin, I have a current funding from Varian Medical System under the master agreement between University of Pennsylvania and

Against all odds: Tales of survival and growth of the Foundational Approaches in Science Teaching (FAST) project

Science.gov (United States)

Yamamoto, Karen Kina

This study examines the dynamics of survival and growth of curricular and instructional innovations. It focuses on the Foundational Approaches in Science Teaching (FAST) project, a long-term survivor of reform in science education. Key questions guiding this study include: (1) How did the FAST project survive over the past 30 years? (2) What elements are essential for long-term survival and growth of an innovative science program? (3) Why did the project continue to survive amidst several waves of educational reform? The core of my conceptual framework is that the odds of survival and growth of curricular and instructional innovations are increased by the extent to which resources, theory-based curriculum development processes, and professional development strategies are not only incorporated into but also interdependent within a project. With this framework as a guide, the main methods of data collection were document analysis, interviews, and observations. FAST, developed by the University of Hawaii's Curriculum Research and Development Group (CRDG), consists of a sequential and interdisciplinary middle and high school science program for students in grades 6-10. According to the results of this study, the project was able to survive by receiving constant organizational support from CRDG and a steady source of State funding through the university since 1966; it also retained a relatively small but stable staff of highly qualified project personnel. Formulated on a discipline-based theory that values development of students' intellectual capacities as the platform for curriculum research, design, and development, the FAST project translated this vision of science education into key elements of an innovative program that survived and thrived: (1) an interdisciplinary program consisting of physical, biological, and earth sciences; inquiry as content and process; history and philosophy of science; and links between and among sciences, technology, and society; and (2

The Role of Project Science in the Chandra X-Ray Observatory

Science.gov (United States)

O'Dell, Stephen L.; Weisskopf, Martin C.

2006-01-01

The Chandra X-Ray Observatory, one of NASA's Great Observatories, has an outstanding record of scientific and technical success. This success results from the efforts of a team comprising NASA, its contractors, the Smithsonian Astrophysical Observatory, the instrument groups, and other elements of the scientific community, including thousands of scientists who utilize this powerful facility for astrophysical research. We discuss the role of NASA Project Science in the formulation, development, calibration, and operation of the Chandra X-ray Observatory. In addition to representing the scientific community within the Project, Project Science performed what we term "science systems engineering". This activity encompasses translation of science requirements into technical requirements and assessment of the scientific impact of programmatic and technical trades. We briefly describe several examples of science systems engineering conducted by Chandra Project Science.

Innovative Project Activities in Science [From the NSTA Study of Innovative Project Activities

Science.gov (United States)

Science Teacher, 1975

1975-01-01

Describes four projects chosen as innovative project activities in science which exhibited identification of unique or novel problems and creative approaches to their solutions. Projects included a study of fish in Lake Erie, a goat raising project, an analysis of terrestrial plant ecology and soil composition, and a study of marine and wetlands…

Continued multidisciplinary project-based learning - implementation in health informatics.

Science.gov (United States)

Wessel, C; Spreckelsen, C

2009-01-01

Problem- and project-based learning are approved methods to train students, graduates and post-graduates in scientific and other professional skills. The students are trained on realistic scenarios in a broader context. For students specializing in health informatics we introduced continued multidisciplinary project-based learning (CM-PBL) at a department of medical informatics. The training approach addresses both students of medicine and students of computer science. The students are full members of an ongoing research project and develop a project-related application or module, or explore or evaluate a sub-project. Two teachers guide and review the students' work. The training on scientific work follows a workflow with defined milestones. The team acts as peer group. By participating in the research team's work the students are trained on professional skills. A research project on a web-based information system on hospitals built the scenario for the realistic context. The research team consisted of up to 14 active members at a time, who were scientists and students of computer science and medicine. The well communicated educational approach and team policy fostered the participation of the students. Formative assessment and evaluation showed a considerable improvement of the students' skills and a high participant satisfaction. Alternative education approaches such as project-based learning empower students to acquire scientific knowledge and professional skills, especially the ability of life-long learning, multidisciplinary team work and social responsibility.

Integrating Inquiry-Based Science and Education Methods Courses in a "Science Semester" for Future Elementary Teachers

Science.gov (United States)

Madsen, J.; Fifield, S.; Allen, D.; Brickhouse, N.; Dagher, Z.; Ford, D.; Shipman, H.

2001-05-01

In this NSF-funded project we will adapt problem-based learning (PBL) and other inquiry-based approaches to create an integrated science and education methods curriculum ("science semester") for elementary teacher education majors. Our goal is to foster integrated understandings of science and pedagogy that future elementary teachers need to effectively use inquiry-based approaches in their classrooms. This project responds to calls to improve science education for all students by making preservice teachers' experiences in undergraduate science courses more consistent with reforms at the K-12 level. The involved faculty teach three science courses (biology, earth science, physical science) and an elementary science education methods course that are degree requirements for elementary teacher education majors. Presently, students take the courses in variable sequences and at widely scattered times. Too many students fail to appreciate the value of science courses to their future careers as teachers, and when they reach the methods course in the junior year they often retain little of the science content studied earlier. These episodic encounters with science make it difficult for students to learn the content, and to translate their understandings of science into effective, inquiry-based teaching strategies. To encourage integrated understandings of science concepts and pedagogy we will coordinate the science and methods courses in a junior-year science semester. Traditional subject matter boundaries will be crossed to stress shared themes that teachers must understand to teach standards-based elementary science. We will adapt exemplary approaches that support both learning science and learning how to teach science. Students will work collaboratively on multidisciplinary PBL activities that place science concepts in authentic contexts and build learning skills. "Lecture" meetings will be large group active learning sessions that help students understand difficult

The I-Cleen Project (Inquiring on CLimate & ENergy). Research Meets Education in AN Inquiry-Based Approach to Earth System Science in Italian Classrooms

Science.gov (United States)

Cattadori, M.; Editorial Staff of the I-CLEN Project

2011-12-01

Italian citizens' perception of the seriousness of the issue of climate change is one of the lowest in Europe (Eurobarometer survey, 2008), running next to last among the 28 EU Nations. This has recently driven many national science institutions to take action in order to connect society with the complexities and consequences of climate change. These connection initiatives have encountered a certain deal of opposition in Italian schools. A fact most likely due both to a further weakening of the use of inquiry-based educational practices adopted by teachers and to their reluctance to cooperate on a professional level, which hinders the diffusion of educational practices. I-CLEEN (Inquiring on CLimate and Energy, www.icleen.museum) is a service that offers a new type of link between schools and the complexity of climate change. The project took off in 2008 thanks to the Trento Science Museum (former Tridentine Museum of Natural Science), one of the major Italian science museums that includes both research and science education and dissemination departments. The main aim is to create, using the tools of professional cooperation, a free repository of educational resources that can support teachers in preparing inquiry-based lessons on climate change and earth system science topics, making the task less of a burden. I-CLEEN is inspired by many models, which include: the ARISE (Andrill Research Immersion for Science Educators), the OER (Open Educational Resources) models and those of other projects that have developed similar information gateways such as LRE (Learning Resource Exchange) and DLESE (Digital Library on Earth Science Education). One of the strategies devised by I-CLEEN is to rely upon an editorial team made up of a highly selected group of teachers that interacts with the researchers of the museum and of other Earth system science research centres like the National Institute of Geophysics and Volcanology (INGV). Resource selection, production, revision and

Hydrostatic Pressure Project: Linked-Class Problem-Based Learning in Engineering

Science.gov (United States)

Davis, Freddie J.; Lockwood-Cooke, Pamela; Hunt, Emily M.

2011-01-01

Over the last few years, WTAMU Mathematics, Engineering and Science faculty has used interdisciplinary projects as the basis for implementation of a linked-class approach to Problem-Based Learning (PBL). A project that has significant relevance to engineering statics, fluid mechanics, and calculus is the Hydrostatic Pressure Project. This project…

Strengthening Science-based Environmental Policy Development in ...

International Development Research Centre (IDRC) Digital Library (Canada)

Strengthening Science-based Environmental Policy Development in Burma's Democratic ... IDRC is providing funding to Simon Fraser University to support a network of ... The project will also encourage and assist in the creation of a business ...

Project Earth Science

CERN Document Server

Holt, Geoff

2011-01-01

Project Earth Science: Astronomy, Revised 2nd Edition, involves students in activities that focus on Earth's position in our solar system. How do we measure astronomical distances? How can we look back in time as we gaze across vast distances in space? How would our planet be different without its particular atmosphere and distance to our star? What are the geometries among Earth, the Moon, and the Sun that yield lunar phases and seasons? Students explore these concepts and others in 11 teacher-tested activities.

Application of Technology in Project-Based Distance Learning

Directory of Open Access Journals (Sweden)

Ali Mehrabian

2008-06-01

Full Text Available Present technology and the accessibility of internet have made distance learning easier, more efficient, and more convenient for students. This technology allows instructors and students to communicate asynchronously, at times and locations of their own choosing, by exchanging printed or electronic information. The use of project-based approach is being recognized in the literature as a potential component of courses in the faculties of engineering, science, and technology. Instructors may have to restructure their course differently to accommodate and facilitate the effectiveness of distance learning. A project-based engineering course, traditionally taught in a classroom settings using live mode at the College of Engineering and Computer Sciences at the University of Central Florida (UCF has been transformed to a distance course taught using distance modes. In this case, pedagogical transitions and adjustments are required, in particular for obtaining an optimal balance between the course material and the project work. Project collaboration in groups requires communication, which is possible with extensive utilization of new information and communication technology, such as virtual meetings. This paper discusses the course transition from live to distance modes and touches on some issues as they relate to the effectiveness of this methodology and the lessons learned from its application within different context. More specifically, this discussion includes the benefit of implementing project-based work in the domain of the distance learning courses.

Deposition of Cu-doped PbS thin films with low resistivity using DC sputtering

Directory of Open Access Journals (Sweden)

Hariyadi Soetedjo

2018-03-01

Full Text Available Investigation of the electrical resistivity of Cu-doped PbS thin films has been carried out. The films were prepared using a DC sputtering technique. The doping was achieved by introducing the Cu dopant plate material directly on the surface of the PbS sputtering target plate. SEM-EDX data shows the Cu concentration in the PbS film to be proportional to the Cu plate diameter. The XRD pattern indicates the film is in crystalline cubic form. The Hall effect measurement shows that Cu doping yields an increase in the carrier concentration to 3.55 × 1019 cm−3 and a significant decrease in electrical resistivity. The lowest resistivity obtained was 0.13 Ωcm for a Cu concentration of 18.5%. Preferential orientation of (1 1 1 and (2 0 0 occurs during deposition. Keywords: Thin films, Lead sulfide, Sputtering, Resistivity, Semiconductor, Infrared

Citizen Science in the Digital Age: examples of Innovative Projects that are Saving Lives across the United States and Internationally.

Science.gov (United States)

Haines-Stiles, G.; Abdalati, W.; Akuginow, E.

2017-12-01

Citizen science and crowdsourcing can literally save lives, whether responding to natural or human-caused disasters, and their effectiveness is all the more enhanced when volunteer observers collaborate with professional researchers. The NSF-funded THE CROWD & THE CLOUD public television series premiered on PBS stations in April 2017, and is hosted by former NASA Chief Scientist Waleed Abdalati: it continues streaming at CrowdAndCloud.org. Its four episodes feature examples directly relevant to this session, vividly demonstrating the power and potential of "Citizen Science in the Digital Age." In "Citizens + Scientists" a peer-reviewed journal article, authored by a respected MD but based on Bucket Brigade citizen science data on air quality surrounding oil and gas developments, features prominently in New York State's ban on fracking. In the wake of the Flint disaster, Virginia Tech scientists support community monitoring of lead in Philadelphia's drinking water. Citizens begin to appreciate the arcane scientific and technical details of EPA's Lead and Copper Rule, and STEM is seen to be of vital, daily significance. In "Even Big Data Starts Small" OpenStreetMap volunteers digitize satellite data to help first responders following the devastating 2015 Nepal earthquake, and Public Lab members—enthusiastic Makers and Millennials—fly modified off-the-shelf cameras beneath balloons and kites to track the BP oil spill, continuing their environmental watchdog work up through the present. CoCoRaHS observers (the Community Collaborative Rain, Hail and Snow Network) submit high quality data that has come to be trusted by NOAA's NWS and other federal agencies, enhancing flash flood warnings while project volunteers begin to appreciate the extreme variabity of local weather. Today's citizen science is much more than birds, bees and butterflies, although all those are also being protected by volunteered citizen data that helps shape state and federal conservation policies

Advertising Citizen Science: A Trailer for the Citizen Sky Project

Science.gov (United States)

Wyatt, Ryan; Price, A.

2012-01-01

Citizen Sky is a multi-year, NSF funded citizen science project involving the bright and mysterious variable star epsilon Aurigae. The project was conceived by the IYA 2009 working group on Research Experiences for Students, Teachers, and Citizen-Scientists. Citizen Sky goes beyond simple observing to include a major data analysis component, introducing participants to the full scientific process from background research to paper writing for a peer-reviewed journal. As a means of generating interest in the project, the California Academy of Sciences produced a six-minute "trailer” formatted for both traditional and fulldome planetariums as well as HD and web applications. This talk will review the production process for the trailer as well as the methods of distribution via planetariums, social media, and other venues_along with an update on the Citizen Sky Project as a whole. We will show how to use a small, professionally-produced planetarium trailer to help spread word on a citizen science project. We will also show preliminary results on a study about how participation level/type in the project affects science learning.

Making the Invisible Visible: The Oklahoma Science Project.

Science.gov (United States)

McCarty, Robbie; Pedersen, Jon E.

2002-01-01

Reports that teachers in preservice education programs still view the teaching of science much in the same traditional ways as our predecessors. "The Oklahoma Science Project (OSP) Model for Professional Development: Practicing Science Across Contexts" will build discourses and relationships that can be extended across contexts to establish…

Scientific literacy of adult participants in an online citizen science project

Science.gov (United States)

Price, Charles Aaron

Citizen Science projects offer opportunities for non-scientists to take part in scientific research. Scientific results from these projects have been well documented. However, there is limited research about how these projects affect their volunteer participants. In this study, I investigate how participation in an online, collaborative astronomical citizen science project can be associated with the scientific literacy of its participants. Scientific literacy is measured through three elements: attitude towards science, belief in the nature of science and competencies associated with learning science. The first two elements are measured through a pre-test given to 1,385 participants when they join the project and a post-test given six months later to 125 participants. Attitude towards science was measured using nine Likert-items custom designed for this project and beliefs in the nature of science were measured using a modified version of the Nature of Science Knowledge scale. Responses were analyzed using the Rasch Rating Scale Model. Competencies are measured through analysis of discourse occurring in online asynchronous discussion forums using the Community of Inquiry framework, which describes three types of presence in the online forums: cognitive, social and teaching. Results show that overall attitudes did not change, p = .225. However, there was significant change towards attitudes about science in the news (positive) and scientific self efficacy (negative), p impact on some aspects of scientific literacy. Using the Rasch Model allowed us to uncover effects that may have otherwise been hidden. Future projects may want to include social interactivity between participants and also make participants specifically aware of how they are contributing to the entire scientific process.

Spin-coating deposition of PbS and CdS thin films for solar cell application

Energy Technology Data Exchange (ETDEWEB)

Patel, Jayesh; Mighri, Frej [Laval University, CREPEC, Department of Chemical Engineering, Quebec, QC (Canada); Ajji, Abdellah [Ecole Polytechnique, CREPEC, Chemical Engineering Department, Montreal, QC (Canada); Tiwari, Devendra; Chaudhuri, Tapas K. [Charotar University of Science and Technology (CHARUSAT), Dr. K.C. Patel Research and Development Centre, Anand District, Gujarat (India)

2014-12-15

In this work, we describe a simple spin-coating deposition technique for lead sulphide (PbS) and cadmium sulphide (CdS) films from a methanolic metal-thiourea complex. The characterization of the films by X-ray diffraction and X-ray photoelectron spectroscopy techniques revealed that pure cubic phase PbS and CdS layers were formed via this method. As shown by atomic force microscopy and scanning electron microscopy results, both films were homogeneous and presented a smooth surface. Optical properties showed that the energy band gap of PbS and CdS films were around 1.65 and 2.5 eV, respectively. The PbS film is p-type in nature with an electrical conductivity of around 0.8 S/cm. The hole concentration and mobility were 2.35 x 10{sup 18} cm{sup -3} and 2.16 x 10{sup -3} cm{sup 2}/V/s, respectively, as determined from Hall measurement. Both films were used to develop a thin film solar cell device of graphite/PbS/CdS/ITO/glass. Device characterization showed the power conversion efficiency of around 0.24 %. The corresponding open circuit voltage, short circuit current and fill factor were 0.570 V, 1.32 mA/cm{sup 2} and 0.32, respectively. (orig.)

Technology Foresight For Youth: A Project For Science and Technology Education in Sweden

Science.gov (United States)

Kendal, Anne Louise

"Technology Foresight for Youth" is a project run by two science museums, two science centres and "Technology Foresight (Sweden)" an organization in which both business and scientists are represented. The project is designed to strengthen young people's interest in ongoing technological work, research and education. It should give them confidence in their own ability both to understand today's techniques including its influence on people's daily lives, and to influence future developments. One part of the project is aimed at school teachers, teacher cooperation groups and students in the age group 12 to 18 years. A second part encourages dialog and meetings by arranging debates, seminars, theatre, science demonstrations in cooperation with business representatives and scientists. A third important part of the project is a special exhibition to be shown at the four cooperating institutions: "To be where I am not - young people's dreams about the future". The exhibition is meant to be sensual, interactive and partly virtual. It will change and grow with time as young people contribute with their thoughts, visions and challenges. Young people in different parts of the country will be able to interact electronically with each other and with the virtual part of the exhibition. The main aim of the project is to develop new interactive pedagogic methods for science and technology based on young people's own visions about the future.

Science Literacy Project, August 2006 - August 2008

Energy Technology Data Exchange (ETDEWEB)

Nasseh, Bizhan [Ball State Univ., Muncie, IN (United States)

2008-08-01

Ball State University (BSU) was the recipient of a U.S. Department of Energy award to develop educational games teaching science and math. The Science Media Program will merge Ball State University’s nationally recognized capabilities in education, technology, and communication to develop new, interactive, game-based media for the teaching and learning of science and scientific principles for K-12 students. BSU established a team of educators, researchers, scientists, animators, designers, technology specialists, and hired a professional media developer company (Outside Source Design) from Indianapolis. After six months discussions and assessments the project team selected the following 8 games in Math, Physics, Chemistry, and Biology, 2 from each discipline. The assembled teams were innovative and unique. This new model of development and production included a process that integrated all needed knowledge and expertise for the development of high quality science and math games for K-12 students. This new model has potential to be used by others for the development of the educational games. The uniqueness of the model is to integrate domain experts’ knowledge with researchers/quality control group, and combine a professional development team from the game development company with the academic game development team from Computer Science and Art departments at Ball State University. The developed games went through feasibility tests with selected students for improvement before use in the research activities.

Setting up crowd science projects

NARCIS (Netherlands)

Scheliga, Kaja; Friesike, Sascha; Puschmann, Cornelius; Fecher, Benedikt

2016-01-01

Crowd science is scientific research that is conducted with the participation of volunteers who are not professional scientists. Thanks to the Internet and online platforms, project initiators can draw on a potentially large number of volunteers. This crowd can be involved to support data-rich or

Participatory science and innovation for improved sanitation and hygiene: process and outcome evaluation of project SHINE, a school-based intervention in Rural Tanzania

Directory of Open Access Journals (Sweden)

Erin Hetherington

2017-02-01

Full Text Available Abstract Background Diarrheal disease is a major cause of mortality and morbidity in low and middle income countries with children being disproportionately affected. Project SHINE (Sanitation & Hygiene INnovation in Education is a grassroots participatory science education and social entrepreneurship model to engage youth and the wider community in the development of sustainable strategies to improve sanitation and hygiene. Methods Based in rural and remote Tanzania, this pilot study engaged pastoralist high-school students and communities in the development and evaluation of culturally and contextually relevant strategies to improve sanitation and hygiene. Using a train-the-trainer approach, key activities included teacher workshops, school-based lessons, extra-curricular activities, community events and a One Health sanitation science fair which showcased projects related to water, sanitation and hygiene in relation to human and animal health. The process and outcome of the study were evaluated through qualitative interviews and focus group discussions with diverse project participants, as well as pre- and post- questionnaires completed by students on knowledge, attitudes and practices concerning sanitation and hygiene. Results The questionnaire results at baseline and follow-up showed statistically significant improvements on key measures including a decrease in unhygienic behaviors, an increase in the perceived importance of handwashing and intention to use the toilet, and increased communication in the social network about the importance of clean water and improved sanitation and hygiene practices, however there were no significant changes in sanitation related knowledge. Qualitative data highlighted strong leadership emerging from youth and enthusiasm from teachers and students concerning the overall approach in the project, including the use of participatory methods. There was a high degree of community engagement with hundreds of

Participatory science and innovation for improved sanitation and hygiene: process and outcome evaluation of project SHINE, a school-based intervention in Rural Tanzania.

Science.gov (United States)

Hetherington, Erin; Eggers, Matthijs; Wamoyi, Joyce; Hatfield, Jennifer; Manyama, Mange; Kutz, Susan; Bastien, Sheri

2017-02-07

Diarrheal disease is a major cause of mortality and morbidity in low and middle income countries with children being disproportionately affected. Project SHINE (Sanitation & Hygiene INnovation in Education) is a grassroots participatory science education and social entrepreneurship model to engage youth and the wider community in the development of sustainable strategies to improve sanitation and hygiene. Based in rural and remote Tanzania, this pilot study engaged pastoralist high-school students and communities in the development and evaluation of culturally and contextually relevant strategies to improve sanitation and hygiene. Using a train-the-trainer approach, key activities included teacher workshops, school-based lessons, extra-curricular activities, community events and a One Health sanitation science fair which showcased projects related to water, sanitation and hygiene in relation to human and animal health. The process and outcome of the study were evaluated through qualitative interviews and focus group discussions with diverse project participants, as well as pre- and post- questionnaires completed by students on knowledge, attitudes and practices concerning sanitation and hygiene. The questionnaire results at baseline and follow-up showed statistically significant improvements on key measures including a decrease in unhygienic behaviors, an increase in the perceived importance of handwashing and intention to use the toilet, and increased communication in the social network about the importance of clean water and improved sanitation and hygiene practices, however there were no significant changes in sanitation related knowledge. Qualitative data highlighted strong leadership emerging from youth and enthusiasm from teachers and students concerning the overall approach in the project, including the use of participatory methods. There was a high degree of community engagement with hundreds of community members participating in school-based events

Pacific CRYSTAL Project: Explicit Literacy Instruction Embedded in Middle School Science Classrooms

Science.gov (United States)

Anthony, Robert J.; Tippett, Christine D.; Yore, Larry D.

2010-01-01

Science literacy leading to fuller and informed participation in the public debate about science, technology, society, and environmental (STSE) issues that produce justified decisions and sustainable actions is the shared and central goal of the Pacific CRYSTAL Project. There is broad agreement by science education researchers that learners need to be able to construct and interpret specific scientific discourses and texts to be literate in science. We view these capabilities as components in the fundamental sense of science literacy and as interactive and synergetic to the derived sense of science literacy, which refers to having general knowledge about concepts, principles, and methods of science. This article reports on preliminary findings from Years 1, 2, and 3 of the 5-year Pacific CRYSTAL project that aims to identify, develop, and embed explicit literacy instruction in science programs to achieve both senses of science literacy. A community-based, opportunistic, engineering research and development approach has been utilized to identify problems and concerns and to design instructional solutions for teaching middle school (Grades 6, 7, and 8) science. Initial data indicate (a) opportunities in programs for embedding literacy instruction and tasks; (b) difficulties generalist teachers have with new science curricula; (c) difficulties specialist science teachers have with literacy activities, strategies, genre, and writing-to-learn science tasks; and (d) potential literacy activities (vocabulary, reading comprehension, visual literacy, genre, and writing tasks) for middle school science. Preinstruction student assessments indicate a range of challenges in achieving effective learning in science and the need for extensive teacher support to achieve the project’s goals. Postinstructional assessments indicate positive changes in students’ ability to perform target reading and writing tasks. Qualitative data indicate teachers’ desire for external direction

Live Storybook Outcomes of Pilot Multidisciplinary Elementary Earth Science Collaborative Project

Science.gov (United States)

Soeffing, C.; Pierson, R.

2017-12-01

Live Storybook Outcomes of pilot multidisciplinary elementary earth science collaborative project Anchoring phenomena leading to student led investigations are key to applying the NGSS standards in the classroom. This project employs the GLOBE elementary storybook, Discoveries at Willow Creek, as an inspiration and operational framework for a collaborative pilot project engaging 4th grade students in asking questions, collecting relevant data, and using analytical tools to document and understand natural phenomena. The Institute of Global Environmental Strategies (IGES), a GLOBE Partner, the Outdoor Campus, an informal educational outdoor learning facility managed by South Dakota Game, Fish and Parks, University of Sioux Falls, and All City Elementary, Sioux Falls are collaborating partners in this project. The Discoveries at Willow Creek storyline introduces young students to the scientific process, and models how they can apply science and engineering practices (SEPs) to discover and understand the Earth system in which they live. One innovation associated with this project is the formal engagement of elementary students in a global citizen science program (for all ages), GLOBE Observer, and engaging them in data collection using GLOBE Observer's Cloud and Mosquito Habitat Mapper apps. As modeled by the fictional students from Willow Creek, the 4th grade students will identify their 3 study sites at the Outdoor Campus, keep a journal, and record observations. The students will repeat their investigations at the Outdoor Campus to document and track change over time. Students will be introduced to "big data" in a manageable way, as they see their observations populate GLOBE's map-based data visualization and . Our research design recognizes the comfort and familiarity factor of literacy activities in the elementary classroom for students and teachers alike, and postulates that connecting a science education project to an engaging storybook text will contribute to a

The book of science mysteries classroom science activities to support student enquiry-based learning

CERN Document Server

McOwan, Peter; Olivotto, Cristina

2015-01-01

In this booklet, you will be introduced to an exciting new way to teach science in your classroom. The TEMI project (Teaching Enquiry with Mysteries Incorporated) is an EU-funded project that brings together experts in teacher training from across Europe to help you introduce enquiry-based learning successfully in the classroom and improve student engagement and skills.

Mega-science accelerator projects in China and their impact on economy

International Nuclear Information System (INIS)

Zhang Chuang

2012-01-01

Along with the rapid development of national economy in China, a number of mega-science projects have been or being constructed. In respect to the large accelerator-based projects, the Beijing Electron-Positron Colliders (BEPC) and its upgrading project BEPCⅡ, the Hefei Light Source (HLS), the Heavy Ion Research Facility in Lanzhou (HIRFL) and its Cooling Storage Rings (HIRFL-CSR) and the Shanghai Synchrotron Radiation Facility (SSRF) were successfully constructed and put into operation. The Beijing Radioactive Ion Facility (BRIF) and the China Spallation Neutron Source (CSNS) are under construction. A particle accelerator is an integration of many HI-tech components. In order to reach the scientific goal of an accelerator project, a great deal new technologies need to be developed during its construction and operation and thus speed up technology development and this will positively impact on the economy. In this paper, the mega-science accelerator projects are briefly described and applications of accelerators in the economy are reviewed. The paper emphasizes spin-off of the accelerator technology developed during R and D and construction of the projects. Approaches of collaboration between academia and industry are discussed. With some examples, the benefits experienced in the laboratory-industry collaboration and approach of its economic compact are illustrated. (author)

Group Projects and the Computer Science Curriculum

Science.gov (United States)

Joy, Mike

2005-01-01

Group projects in computer science are normally delivered with reference to good software engineering practice. The discipline of software engineering is rapidly evolving, and the application of the latest 'agile techniques' to group projects causes a potential conflict with constraints imposed by regulating bodies on the computer science…

Post secondary project-based learning in science, technology, engineering and mathematics

Directory of Open Access Journals (Sweden)

Rachel A Ralph

2016-03-01

Full Text Available Project-based learning (PjBL - to distinguish from problem-based learning - PBL has become a recurrent practice in K-12 classroom environments. As PjBL has become prominent in K-12 classrooms, it has also surfaced in post-secondary institutions.  The purpose of this paper is to examine the research that has studied a variety of science, technology, engineering and mathematic subjects using PjBL in post-secondary classrooms. Eleven articles (including qualitative, quantitative and mixed methods were included.  The format includes: an introduction and background (which defines PjBL and STEM, research methods, quality appraisal used, results, and a discussion, future research and a conclusion.  Two tables and two figures are included. In this paper, theoretical backgrounds and key terms were identified, followed by a literature review discussing four themes: content knowledge, interdisciplinary skills, collaboration and skill development for future education and careers.  Results suggested that there is a positive connection between content knowledge learning and PjBL in collaborative settings.  Additionally, some negative perceptions arose regarding teamwork situations.  Interdisciplinary skills were achieved, but quite limited in post-secondary classrooms.  PjBL and STEM were perceived to be important for future education and careers.  Future research needs to be completed and institutional curriculum changes informed by the results of this research need to occur to further explore interdisciplinary courses and the use of PjBL.

An Analysison Provincial Medical Science Basic Research Competitiveness Based on the National Natural Science Foundation of China

Directory of Open Access Journals (Sweden)

Xing Xia

2017-06-01

Full Text Available [Purpose/significance] The National Natural Science Foundation of China (NSFC is one of the most important channels to support basic research in China. Competition for funding by the NSFC has been a very important indicator to measure the basic research level of various province and scientific research institutions. [Method/process] By combing and analyzing the status quo of NSFC in medical science, it is helpful to narrow the provincial gap and improve the basic research of medical science in China. Based on the project information of NSFC and previous scholars’ research, the paper update the index of basic research competitiveness, and analyzes project number and project funding of medical science during 2006-2016. At the same time, the competitiveness of medical science basic research and its changing trend in 31 provinces of China are analyzed. [Result/conclusion] The result shows that, in recent years, China’s basic scientific research has greatly improved, but there is a large gap between the provinces.

Luminescence and transient lifetime studies for energy transfer of PbS QD films

Science.gov (United States)

Wang, Joanna S.; Ullrich, Bruno; Dass, Chandriker K.; Das, Anirban; Wai, Chien M.; Brown, Gail J.; Hendrickson, Joshua R.

2017-08-01

Quantum confined semiconductor materials in colloidal form have drawn great attention in scientific communities due to the size-tunability, which controls their optical properties. PbS quantum dots (QDs) are exciting candidates for quantum optics, particularly due to the control of the QD sizes during the synthetic process enabling the realization of precisely tunable emission properties in the near-infrared region. Differently sized pairs of PbS QDs were deposited onto glass substrates to form thin films using supercritical CO2 (sc-CO2) deposition and solvent deposition methods (SDM). The fluorescence and photoluminescence (PL) spectra obtained from these closely packed films prepared by the sc-CO2 method reveal effective Förster resonance energy transfer (FRET) between two different sized dots, while the films composed of three different QD sizes show an even more effective FRET from the smallest to the largest ones. Energy transfer can be observed more directly by temporally resolved PL decay of mixed dots. By means of transient lifetime measurements, a mixed PbS film with 3.1 and 4.7 nm QDs was studied for FRET by time correlated single photon counting. The PL peak of the 3.1 nm QDs is quenched with respect to the emission of the 4.7 nm QDs and decays faster, and the best fit for the lifetime (decay constant)-1 is a biexponential decay mode. The long wavelength decay (4.7 nm QDs) is best fit by a mono-exponential equation. More theoretical and experimental work is required for a thorough understanding of the radiative lifetimes of PbS QDs in mixed QD systems.

The muon science facility at the JAERI/KEK joint project

International Nuclear Information System (INIS)

Miyake, Y.; Nishiyama, K.; Makimura, S.; Kawamura, N.; Shimomura, K.; Kadono, R.; Higemoto, W.; Fukuchi, K.; Beveridge, J.L.; Ishida, K.; Matsuzaki, T.; Watanabe, I.; Matsuda, Y.; Sakamoto, S.; Nakamura, S.N.; Nagamine, K.

2003-01-01

The Muon Science Facility is one of the experimental arenas of the JAERI/KEK Joint Project, which also includes neutron science, particle and nuclear physics, neutrino physics and nuclear transmutation science. Following the recommendations by the review committees, the Joint Project was finally approved for construction at the end of December, 2000. The approval is for Phase 1 of 1335 Oku Yen out of the total project cost of 1890 Oku Yen. It is planned to locate the muon science experimental area together with the neutron facility in an integrated building, as a facility for materials and life science studies. Because its construction will be started in April 2003, we are now working to complete the detailed design of the building structure, shielding, electrical services, cooling water, primary proton beam line, one muon target and secondary beam lines

Inquiry Based Science Education og den sociokulturelt forankrede dialog i naturfagsundervisningen

DEFF Research Database (Denmark)

Østergaard, Lars Domino

2012-01-01

Through study, investigation and discussion of the concept Best Practice in science education (Ellebæk & Østergaard, 2009) it was shown, that the dialogue in the teaching sequences was an important factor for the children’s understanding, engagement and interest for the science subjects......). The method is central in the action research project NatSats, where focus is on chidren’s hypothesizing and the way teacher’s use dialogue in their teaching or guiding of children in kindergarten and primary school. Results from the project indicate that an open and interrogative dialogue based...... and phenomena. In this article we will discuss dialogue in the light of sociocultural learning theories, and relate it to Inquiry Based Science Education (IBSE), as the pedagogical and didactical method, which are promoted most strongly these years (e.g. in the inter-European Pollen and Fibonacci projects...

Assessment of Project-Based Learning in a MECHATRONICS Context

Science.gov (United States)

Doppelt, Yaron

2005-01-01

Project-based learning (PBL) that has authenticity in the pupils' world enables the teaching of science and technology to pupils from a variety of backgrounds. PBL has the potential to enable pupils to research, plan, design, and reflect on the creation of technological projects (Doppelt, 2000). Engineering education, which is common in Israel,…

Supercritical synthesis and in situ deposition of PbS nanocrystals with oleic acid passivation for quantum dot solar cells

Energy Technology Data Exchange (ETDEWEB)

Tavakoli, M.M. [Department of Materials Science and Engineering, Sharif University of Technology, 14588 Tehran (Iran, Islamic Republic of); Simchi, A., E-mail: simchi@sharif.edu [Department of Materials Science and Engineering, Sharif University of Technology, 14588 Tehran (Iran, Islamic Republic of); Institute for Nanoscience and Nanotechnology, Sharif University of Technology, 14588 Tehran (Iran, Islamic Republic of); Aashuri, H. [Department of Materials Science and Engineering, Sharif University of Technology, 14588 Tehran (Iran, Islamic Republic of)

2015-04-15

Colloidal quantum dot solar cells have recently attracted significant attention due to their low-processing cost and surging photovoltaic performance. In this paper, a novel, reproducible, and simple solution-based process based on supercritical fluid toluene is presented for in situ growth and deposition PbS nanocrystals with oleic-acid passivation. A lead precursor containing sulfur was mixed with oleic acid in toluene and processed in a supercritical fluid condition at different temperatures of 140, 270 and 330 °C for 20 min. The quantum dots were deposited on a fluorine-doped tin oxide glass substrate inside the supercritical reactor. Transmission electron microscopy, X-ray diffraction, absorption and dynamic light scattering showed that the nanocrystals processed at the supercritical condition (330 °C) are fully crystalline with a narrow size distribution of ∼3 nm with an absorption wavelength of 915 nm (bandgap of 1.3 eV). Fourier transform infrared spectroscopy indicated that the PbS quantum dots are passivated by oleic acid molecules during the growth. Photovoltaic characteristics of Schottky junction solar cells showed an improvement over devices prepared by spin-coating. - Highlights: • Supercritical fluid processing and in situ deposition of PbS QDs are presented. • The prepared nanocrystals are mono-dispersed with an optical bandgap of 1.3 eV. • Photovoltaic performance of the in situ deposited nanocrystals is reported. • An improved PV performance compared to spin coated Schottky solar cells is shown.

An Evaluation of the Science Education Component of the Cross River State Science and Technical Education Project

Science.gov (United States)

Ekuri, Emmanuel Etta

2012-01-01

The Cross River State Science and Technical Education Project was introduced in 1992 by edict number 9 of 20 December 1991, "Cross River State Science and Technical Education Board Edit, 20 December, 1991", with the aim of improving the quality of science teaching and learning in the state. As the success of the project depends…

Photoelectron emission as a tool to assess dose of electron radiation received by ZrO2:PbS films

International Nuclear Information System (INIS)

Krumpane, Diana; Dekhtyar, Yury; Surkova, Indra; Romanova, Marina

2013-01-01

PbS nano dots embedded in ZrO 2 thin film matrix (ZrO 2 :PbS films) were studied for application in nanodosimetry of electron radiation used in radiation therapy. ZrO 2 :PbS films were irradiated with 9 MeV electron radiation with doses 3, 7 and 10 Gy using medical linear accelerator. Detection of the dosimetric signal was made by measuring and comparing photoelectron emission current from ZrO 2 :PbS films before and after irradiation. It was found that electron radiation decreased intensity of photoemission current from the films. Derivatives of the photoemission spectra were calculated and maximums at photon energies 5.65 and 5.75 eV were observed. Amplitude of these maximums decreased after irradiation with electrons. Good linear correlation was found between the relative decrease of the intensity of these maximums and dose of electron radiation. Observed changes in photoemission spectra from ZrO 2 :PbS films under influence of electron radiation suggested that the films may be considered to be effective material for electron radiation dosimetry. Photoelectron emission is a tool that allows to read the signal from such dosimeter. (authors)

Improving Science Attitude and Creative Thinking through Science Education Project: A Design, Implementation and Assessment

Science.gov (United States)

Sener, Nilay; Türk, Cumhur; Tas, Erol

2015-01-01

The purpose of this study is to examine the effects of a science education project implemented in different learning environments on secondary school students' creative thinking skills and their attitudes to science lesson. Within this scope, a total of 50 students who participated in the nature education project in Samsun City in 2014 make up the…

The history and science of the Manhatten project

International Nuclear Information System (INIS)

Reed, Bruce Cameron

2014-01-01

This is the only popular-level history of the Project prepared by a writer who is a physicist and who has broad knowledge of the relevant scientific details. Ideal for readers who have no specialized scientific background but who want to learn more about how atomic bombs came to be. Relevant scientific concepts are explained in the text as they are needed. For readers who do possess some scientific background (high-school physics), this book will provide a deeper understanding of some of the technical issues involved in developing atomic bombs. An ideal text for a college-level ''general education'' history or science class. Based on years of research by the author into the physics of nuclear weapons, augmented by familiarity with relevant official archival documentation. The development of atomic bombs under the auspices of the U. S. Army's Manhattan Project during World War II is considered to be the outstanding news story of the twentieth century. In this book, a physicist and expert on the history of the Project presents a comprehensive overview of this momentous achievement. The first three chapters cover the history of nuclear physics from the discovery of radioactivity to the discovery of fission, and would be ideal for instructors of a sophomore-level ''Modern Physics'' course. Student-level exercises at the ends of the chapters are accompanied by answers. Chapter 7 covers the physics of first-generation fission weapons at a similar level, again accompanied by exercises and answers. For the interested layman and for non-science students and instructors, the book includes extensive qualitative material on the history, organization, implementation, and results of the Manhattan Project and the Hiroshima and Nagasaki bombing missions. The reader also learns about the legacy of the Project as reflected in the current world stockpiles of nuclear weapons.

The history and science of the Manhatten project

Energy Technology Data Exchange (ETDEWEB)

Reed, Bruce Cameron [Alma College, Alma, MI (United States). Dept. of Physics

2014-03-01

This is the only popular-level history of the Project prepared by a writer who is a physicist and who has broad knowledge of the relevant scientific details. Ideal for readers who have no specialized scientific background but who want to learn more about how atomic bombs came to be. Relevant scientific concepts are explained in the text as they are needed. For readers who do possess some scientific background (high-school physics), this book will provide a deeper understanding of some of the technical issues involved in developing atomic bombs. An ideal text for a college-level ''general education'' history or science class. Based on years of research by the author into the physics of nuclear weapons, augmented by familiarity with relevant official archival documentation. The development of atomic bombs under the auspices of the U. S. Army's Manhattan Project during World War II is considered to be the outstanding news story of the twentieth century. In this book, a physicist and expert on the history of the Project presents a comprehensive overview of this momentous achievement. The first three chapters cover the history of nuclear physics from the discovery of radioactivity to the discovery of fission, and would be ideal for instructors of a sophomore-level ''Modern Physics'' course. Student-level exercises at the ends of the chapters are accompanied by answers. Chapter 7 covers the physics of first-generation fission weapons at a similar level, again accompanied by exercises and answers. For the interested layman and for non-science students and instructors, the book includes extensive qualitative material on the history, organization, implementation, and results of the Manhattan Project and the Hiroshima and Nagasaki bombing missions. The reader also learns about the legacy of the Project as reflected in the current world stockpiles of nuclear weapons.

2011 Joint Science Education Project: Research Experience in Polar Science

Science.gov (United States)

Wilkening, J.; Ader, V.

2011-12-01

The Joint Science Education Project (JSEP), sponsored by the National Science Foundation, is a two-part program that brings together students and teachers from the United States, Greenland, and Denmark, for a unique cross-cultural, first-hand experience of the realities of polar science field research in Greenland. During JSEP, students experienced research being conducted on and near the Greenland ice sheet by attending researcher presentations, visiting NSF-funded field sites (including Summit and NEEM field stations, both located on the Greenland ice sheet), and designing and conducting research projects in international teams. The results of two of these projects will be highlighted. The atmospheric project investigated the differences in CO2, UVA, UVB, temperature, and albedo in different Arctic microenvironments, while also examining the interaction between the atmosphere and water present in the given environments. It was found that the carbon dioxide levels varied: glacial environments having the lowest levels, with an average concentration of 272.500 ppm, and non-vegetated, terrestrial environments having the highest, with an average concentration of 395.143 ppm. Following up on these results, it is planned to further investigate the interaction of the water and atmosphere, including water's role in the uptake of carbon dioxide. The ecology project investigated the occurrence of unusual large blooms of Nostoc cyanobacteria in Kangerlussuaq area lakes. The water chemistry of the lakes which contained the cyanobacteria and the lakes that did not were compared. The only noticeable difference was of the lakes' acidity, lakes containing the blooms had an average pH value of 8.58, whereas lakes without the blooms had an average pH value of 6.60. Further investigation of these results is needed to determine whether or not this was a cause or effect of the cyanobacteria blooms. As a next step, it is planned to attempt to grow the blooms to monitor their effects on

Project- Based Learning and Problem-Based Learning: Are They Effective to Improve Student's Thinking Skills?

OpenAIRE

Anazifa, R. D; Djukri, D

2017-01-01

The study aims at finding (1) the effect of project-based learning and problem-based learning on student's creativity and critical thinking and (2) the difference effect of project-based learning and problem-based learning on student's creativity and critical thinking. This study is quasi experiment using non-equivalent control-group design. Research population of this study was all classes in eleventh grade of mathematics and natural science program of SMA N 1 Temanggung. The participants we...

Collaborative online projects for English language learners in science

Science.gov (United States)

Terrazas-Arellanes, Fatima E.; Knox, Carolyn; Rivas, Carmen

2013-12-01

This paper summarizes how collaborative online projects (COPs) are used to facilitate science content-area learning for English Learners of Hispanic origin. This is a Mexico-USA partnership project funded by the National Science Foundation. A COP is a 10-week thematic science unit, completely online, and bilingual (Spanish and English) designed to provide collaborative learning experiences with culturally and linguistically relevant science instruction in an interactive and multimodal learning environment. Units are integrated with explicit instructional lessons that include: (a) hands-on and laboratory activities, (b) interactive materials and interactive games with immediate feedback, (c) animated video tutorials, (d) discussion forums where students exchange scientific learning across classrooms in the USA and in Mexico, and (e) summative and formative assessments. Thematic units have been aligned to U.S. National Science Education Standards and are under current revisions for alignment to the Common Core State Standards. Training materials for the teachers have been integrated into the project website to facilitate self-paced and independent learning. Preliminary findings of our pre-experimental study with a sample of 53 students (81 % ELs), distributed across three different groups, resulted in a 21 % statistically significant points increase from pretest to posttest assessments of science content learning, t( 52) = 11.07, p = .000.

Citizen science participation in research in the environmental sciences: key factors related to projects' success and longevity.

Science.gov (United States)

Cunha, Davi G F; Marques, Jonatas F; Resende, Juliana C DE; Falco, Patrícia B DE; Souza, Chrislaine M DE; Loiselle, Steven A

2017-01-01

The potential impacts of citizen science initiatives are increasing across the globe, albeit in an imbalanced manner. In general, there is a strong element of trial and error in most projects, and the comparison of best practices and project structure between different initiatives remains difficult. In Brazil, the participation of volunteers in environmental research is limited. Identifying the factors related to citizen science projects' success and longevity within a global perspective can contribute for consolidating such practices in the country. In this study, we explore past and present projects, including a case study in Brazil, to identify the spatial and temporal trends of citizen science programs as well as their best practices and challenges. We performed a bibliographic search using Google Scholar and considered results from 2005-2014. Although these results are subjective due to the Google Scholar's algorithm and ranking criteria, we highlighted factors to compare projects across geographical and disciplinary areas and identified key matches between project proponents and participants, project goals and local priorities, participant profiles and engagement, scientific methods and funding. This approach is a useful starting point for future citizen science projects, allowing for a systematic analysis of potential inconsistencies and shortcomings in this emerging field.

Aeronautics and Aviation Science: Careers and Opportunities Project

Science.gov (United States)

Texter, P. Cardie

1998-01-01

The National Aeronautics and Space Administration funded project, Aeronautics and Aviation Science: Careers and Opportunities has been in operation since July, 1995. This project operated as a collaboration with Massachusetts Corporation for Educational Telecommunications, the Federal Aviation Administration, Bridgewater State College and four targeted "core sites" in the greater Boston area. In its first and second years, a video series on aeronautics and aviation science was developed and broadcast via "live, interactive" satellite feed. Accompanying teacher and student supplementary instructional materials for grades 6-9 were produced and disseminated by the Massachusetts Corporation for Educational Telecommunications (MCET). In the MCET grant application it states that project Take Off! in its initial phase would recruit and train teachers at "core" sites in the greater Boston area, as well as opening participation to other on-line users of MCET's satellite feeds. "Core site" classrooms would become equipped so that teachers and students might become engaged in an interactive format which aimed at not only involving the students during the "live" broadcast of the instructional video series, but which would encourage participation in electronic information gathering and sharing among participants. As a Take Off! project goal, four schools with a higher than average proportion of minority and underrepresented youth were invited to become involved with the project to give these students the opportunity to consider career exploration and development in the field of science aviation and aeronautics. The four sites chosen to participate in this project were: East Boston High School, Dorchester High School, Randolph Junior-Senior High School and Malden High School. In year 3 Dorchester was unable to continue to fully participate and exited out. Danvers was added to the "core site" list in year 3. In consideration of Goals 2000, the National Science Foundation

Corrosion of experimental magnesium alloys in blood and PBS: A gravimetric and microscopic evaluation

International Nuclear Information System (INIS)

Schille, Ch.; Braun, M.; Wendel, H.P.; Scheideler, L.; Hort, N.; Reichel, H.-P.; Schweizer, E.; Geis-Gerstorfer, J.

2011-01-01

Highlights: ► Corrosion of eight Mg–based Biomaterials was tested in saline and human blood. ► Corrosion behaviour in physiological saline and in blood was entirely different. ► Al and Zn had the highest influence on corrosion behaviour in both electrolytes. ► MgAl9 and MgAl9Zn1 showed least corrosion in human whole blood. ► Tests in buffered corrosion media are not sufficient to predict corrosion in vivo. - Abstract: Corrosion tests for medical materials are often performed in simulated body fluids (SBF). When SBF are used for corrosion measurement, the open question is, how well they match the conditions in the human body. The aim of the study was to compare the corrosion behaviour of different experimental magnesium alloys in human whole blood and PBS minus (phosphate buffered saline w/o Ca and Mg) as a simulated body fluid by gravimetric weight measurements and microscopic evaluation. Eight different experimental magnesium alloys, containing neither Mn nor other additives, were manufactured. With these alloys, a static immersion test in PBS minus and a dynamic test using the Chandler-loop model with human whole blood over 6 h were performed. During the static immersion test, the samples were weighed every hour. During the dynamic test, the specimens were weighed before and after the 6 h incubation period in the Chandler-loop. From both tests, the total mass change was calculated for each alloy and the values were compared. Additionally, microscopic pictures from the samples were taken at the end of the test period. All alloys showed different corrosion behaviour in both tests, especially the alloys with high aluminium content, MgAl9 and MgAl9Zn1. Generally, alloys in PBS showed a weight gain due to generation of a microscopically visible corrosion layer, while in the blood test system a more or less distinct weight loss was observed. When alloys are ranked according to corrosion susceptibility, the results differ also between the test systems. The

The Elwha Science Education Project (ESEP): Engaging an Entire Community in Geoscience Education

Science.gov (United States)

Young, R. S.; Kinner, F.

2008-12-01

Native Americans are poorly represented in all science, technology and engineering fields. This under- representation results from numerous cultural, economic, and historical factors. The Elwha Science Education Project (ESEP), initiated in 2007, strives to construct a culturally-integrated, geoscience education program for Native American young people through engagement of the entire tribal community. The ESEP has developed a unique approach to informal geoscience education, using environmental restoration as a centerpiece. Environmental restoration is an increasingly important goal for tribes. By integrating geoscience activities with community tradition and history, project stakeholders hope to show students the relevance of science to their day-to-day lives. The ESEP's strength lies in its participatory structure and unique network of partners, which include Olympic National Park; the non-profit, educational center Olympic Park Institute (OPI); a geologist providing oversight and technical expertise; and the Lower Elwha Tribe. Lower Elwha tribal elders and educators share in all phases of the project, from planning and implementation to recruitment of students and discipline. The project works collaboratively with tribal scientists and cultural educators, along with science educators to develop curriculum and best practices for this group of students. Use of hands-on, place-based outdoor activities engage students and connect them with the science outside their back doors. Preliminary results from this summer's middle school program indicate that most (75% or more) students were highly engaged approximately 90% of the time during science instruction. Recruitment of students has been particularly successful, due to a high degree of community involvement. Preliminary evaluations of the ESEP's outcomes indicate success in improving the outlook of the tribe's youth towards the geosciences and science, in general. Future evaluation will be likewise participatory

Swiss Life Sciences - a science communication project for both schools and the wider public led by the foundation Science et Cité.

Science.gov (United States)

Röthlisberger, Michael

2012-01-01

The foundation Science et Cité was founded 1998 with the aim to inform the wider Swiss public about current scientific topics and to generate a dialogue between science and society. Initiated as an independent foundation by the former State Secretary for Science and Research, Dr. Charles Kleiber, Science et Cité is now attached to the Swiss Academies of Arts and Sciences as a competence center for dialogue with the public. Due to its branches in all language regions of the country, the foundation is ideally suited to initiate and implement communication projects on a nationwide scale. These projects are subdivided into three categories: i) science communication for children/adolescents, ii) establishing a dialogue between science and the wider public, and iii) conducting the role of a national center of competence and networking in science communication. Swiss Life Sciences is a project that fits into all of these categories: a year-round program for schools is complemented with an annual event for the wider public. With the involvement of most of the major Swiss universities, the Swiss National Science Foundation, the foundation Gen Suisse and many other partners, Swiss Life Sciences also sets an example of national networking within the science communication community.

Cartographic science: a compendium of map projections, with derivations

National Research Council Canada - National Science Library

Fenna, Donald

2007-01-01

"From basic projecting to advanced transformations, Cartographic Science: A Compendium of Map Projections, with Derivations comprehensively explores the depiction of a curved world on a flat surface...

The effect of water molecules on the thiol collector interaction on the galena (PbS) and sphalerite (ZnS) surfaces: A DFT study

Energy Technology Data Exchange (ETDEWEB)

Long, Xianhao [School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004 (China); Chen, Ye, E-mail: fby18@126.com [College of Resources and Metallurgy, Guangxi University, Nanning 530004 (China); Chen, Jianhua, E-mail: jhchen@gxu.edu.cn [School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004 (China); College of Resources and Metallurgy, Guangxi University, Nanning 530004 (China); Xu, Zhenghe; Liu, Qingxia [Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 2V4 (Canada); Du, Zheng [National Supercomputing Center in Shenzhen, Shenzhen 518055 (China)

2016-12-15

Highlights: • Water adsorption has a greater effect on the electron distribution of ZnS surface than PbS surface. • Water adsorption decreases the reactivity of ZnS surface atoms but improves that of PbS. • Thiol collectors cannot interact with the hydrated ZnS surface. • The hydration has little influence on the interaction of thiol collectors with PbS surface. - Abstracts: In froth flotation the molecular interaction between reagents and mineral surfaces take place at the solid liquid interface. In this paper, the effect of water molecule on the three typical thiol collectors (xanthate, dithiocarbomate and dithiophosphate) interactions at the galena (PbS) and sphalerite (ZnS) surfaces has been studied adopting density functional theory (DFT). The results suggests that the presence of water molecule shows a greater influence on the electron distribution of ZnS surface than PbS surface, and reduce the reactivity of ZnS surface atoms but improves the reactivity of PbS surface atoms during the reaction with xanthate. Water adsorption could also reduce the covalent binding between Zn and S atoms but have little influence on Pb-S bond. In the presence of water, xanthate, dithiocarbomate (DTC) and dithiophosphate (DTP) could not adsorb on the sphalerite surface. And for galena (PbS) surface, the interaction of DTP is the strongest, then the DTC and the interaction of xanthate is the weakest. These results agree well with the flotation practice.

Testing the robustness of Citizen Science projects: Evaluating the results of pilot project COMBER.

Science.gov (United States)

Chatzigeorgiou, Giorgos; Faulwetter, Sarah; Dailianis, Thanos; Smith, Vincent Stuart; Koulouri, Panagiota; Dounas, Costas; Arvanitidis, Christos

2016-01-01

Citizen Science (CS) as a term implies a great deal of approaches and scopes involving many different fields of science. The number of the relevant projects globally has been increased significantly in the recent years. Large scale ecological questions can be answered only through extended observation networks and CS projects can support this effort. Although the need of such projects is apparent, an important part of scientific community cast doubt on the reliability of CS data sets. The pilot CS project COMBER has been created in order to provide evidence to answer the aforementioned question in the coastal marine biodiversity monitoring. The results of the current analysis show that a carefully designed CS project with clear hypotheses, wide participation and data sets validation, can be a valuable tool for the large scale and long term changes in marine biodiversity pattern change and therefore for relevant management and conservation issues.

A Project-Based Biologically-Inspired Robotics Module

Science.gov (United States)

Crowder, R. M.; Zauner, K.-P.

2013-01-01

The design of any robotic system requires input from engineers from a variety of technical fields. This paper describes a project-based module, "Biologically-Inspired Robotics," that is offered to Electronics and Computer Science students at the University of Southampton, U.K. The overall objective of the module is for student groups to…

Combining Project-based Instruction, Earth Science Content, and GIS Technology in Teacher Professional Development: Is this Holistic Approach Sustainable?

Science.gov (United States)

Rubino-Hare, L.; Bloom, N.; Claesgens, J.; Fredrickson, K.; Henderson-Dahms, C.; Sample, J. C.

2012-12-01

From 2009-2011, with support from the National Science Foundation (ITEST, DRL-0929846) and Science Foundation Arizona (MSAG-0412-09), educators, geologists and geographers at Northern Arizona University (NAU) partnered to offer professional development for interdisciplinary teams of secondary and middle school teachers with a focus on project-based instruction (PBI) using geospatial technologies (GST). While participating in professional development teachers received support and were held accountable to NAU staff. They implemented activities and pedagogical strategies presented, increased knowledge, skills, and confidence teaching with project-based instruction integrating GST, and their students demonstrated learning gains. Changes in student understanding are only observed when teachers continue to implement change, so the question remained: did these changes in practice sustain after official project support ended? In order to determine what, if anything, teachers sustained from the professional development and the factors that promoted or hindered sustained use of teaching with GST and PBI, data were collected one to two years following the professional development. Research questions included a) what pedagogical practices did teachers sustain following the professional learning experiences? and b) what contexts were present in schools that supported or limited the use of geospatial technologies as a teaching and learning tool? Findings from this study indicate that teachers fall into three categories of sustaining implementation - reformed implementers, mechanical implementers and non-implementers. School context was less of a factor in level of implementation than teachers' beliefs and philosophy of teaching and teachers' understanding of technology integration (teaching with technology vs. teaching technology). Case studies of teacher experiences will be presented along with implications for future professional development.

National Academy of Sciences Recommends Continued Support of ALMA Project

Science.gov (United States)

2000-05-01

A distinguished panel of scientists today announced their support for the continued funding of the Atacama Large Millimeter Array (ALMA) Project at a press conference given by the National Academy of Sciences. The ALMA Project is an international partnership between U.S. and European astronomy organizations to build a complete imaging telescope that will produce astronomical images at millimeter and submillimeter wavelengths. The U.S. partner is the National Science Foundation, through Associated Universities, Inc., (AUI), led by Dr. Riccardo Giacconi, and the National Radio Astronomy Observatory (NRAO). "We are delighted at this show of continued support from our peers in the scientific community," said Dr. Robert Brown, ALMA U.S. Project Director and Deputy Director of NRAO. "The endorsement adds momentum to the recent strides we've made toward the building of this important telescope." In 1998, the National Research Council, the working arm of the National Academy of Sciences, charged the Astronomy and Astrophysics Survey Committee to "survey the field of space- and ground-based astronomy and astrophysics" and to "recommend priorities for the most important new initiatives of the decade 2000-2010." In a report released today, the committee wrote that it "re-affirms the recommendations of the 1991 Astronomy and Astrophysics Survey Committee by endorsing the completion of . . . the Millimeter Array (MMA, now part of the Atacama Large Millimeter Array)." In the 1991 report "The Decade of Discovery," a previous committee chose the Millimeter Array as one of the most important projects of the decade 1990-2000. Early last year, the National Science Foundation signed a Memorandum of Understanding with a consortium of European organizations that effectively merged the MMA Project with the European Large Southern Array project. The combined project was christened the Atacama Large Millimeter Array. ALMA, expected to consist of 64 antennas with 12-meter diameter dishes

Collaborative CPD and inquiry-based science in the classroom

DEFF Research Database (Denmark)

Nielsen, Birgitte Lund

on the teaching of science and on collaboration. Qualitative data obtained by following the same teacher teaching Science & Technology from 4th to 6th grade are used to discuss changes in her classroom practice; in particular concerning inquiry-based methods shown in earlier QUEST-research to be understood......Continuous Professional Development (CPD) is crucial for reforming science teaching, but more knowledge is needed about how to embed CPD in teachers’ daily work. The Danish QUEST-project is a long-term collaborative CPD-project designed informed by research and with activities changing rhythmically...... between seminars, individual trials in own classroom, and collaborative activities in the science-team at local schools. The QUEST research is aimed at understanding the relation between individual and social changes. In this study, quantitative data are used to compare the perceived effect from QUEST...

The Human Genome Project: big science transforms biology and medicine.

Science.gov (United States)

Hood, Leroy; Rowen, Lee

2013-01-01

The Human Genome Project has transformed biology through its integrated big science approach to deciphering a reference human genome sequence along with the complete sequences of key model organisms. The project exemplifies the power, necessity and success of large, integrated, cross-disciplinary efforts - so-called 'big science' - directed towards complex major objectives. In this article, we discuss the ways in which this ambitious endeavor led to the development of novel technologies and analytical tools, and how it brought the expertise of engineers, computer scientists and mathematicians together with biologists. It established an open approach to data sharing and open-source software, thereby making the data resulting from the project accessible to all. The genome sequences of microbes, plants and animals have revolutionized many fields of science, including microbiology, virology, infectious disease and plant biology. Moreover, deeper knowledge of human sequence variation has begun to alter the practice of medicine. The Human Genome Project has inspired subsequent large-scale data acquisition initiatives such as the International HapMap Project, 1000 Genomes, and The Cancer Genome Atlas, as well as the recently announced Human Brain Project and the emerging Human Proteome Project.

Mapping epistemic cultures and learning potential of participants in citizen science projects.

Science.gov (United States)

Vallabh, Priya; Lotz-Sisitka, Heila; O'Donoghue, Rob; Schudel, Ingrid

2016-06-01

The ever-widening scope and range of global change and interconnected systemic risks arising from people-environment relationships (social-ecological risks) appears to be increasing concern among, and involvement of, citizens in an increasingly diversified number of citizen science projects responding to these risks. We examined the relationship between epistemic cultures in citizen science projects and learning potential related to matters of concern. We then developed a typology of purposes and a citizen science epistemic-cultures heuristic and mapped 56 projects in southern Africa using this framework. The purpose typology represents the range of knowledge-production purposes, ranging from laboratory science to social learning, whereas the epistemic-cultures typology is a relational representation of scientist and citizen participation and their approach to knowledge production. Results showed an iterative relationship between matters of fact and matters of concern across the projects; the nexus of citizens' engagement in knowledge-production activities varied. The knowledge-production purposes informed and shaped the epistemic cultures of all the sampled citizen science projects, which in turn influenced the potential for learning within each project. Through a historical review of 3 phases in a long-term river health-monitoring project, we found that it is possible to evolve the learning curve of citizen science projects. This evolution involved the development of scientific water monitoring tools, the parallel development of pedagogic practices supporting monitoring activities, and situated engagement around matters of concern within social activism leading to learning-led change. We conclude that such evolutionary processes serve to increase potential for learning and are necessary if citizen science is to contribute to wider restructuring of the epistemic culture of science under conditions of expanding social-ecological risk. © 2016 Society for

Grant Project Information via a Shared Data Base

Directory of Open Access Journals (Sweden)

Justine Roberts

1973-09-01

Full Text Available A quarterly keyword index to campus grant projects is provided by the Health Science Library at the University of California, San Francisco, using a data base created and maintained by the campus' Contracts & Grants Office. The index is printed in KWOC format, using the chief investigator's name as the key to a section of project summaries. A third section is also included, listing the summaries under the name of the sponsoring department.

Collect, analyze and data base for building up the investment reports of Center for Nuclear Science and Technology construction project

International Nuclear Information System (INIS)

Pham Quang Minh; Tran Chi Thanh; Cao Dinh Thanh; Mai Dinh Trung; Hoang Sy Than; Nguyen Nhi Dien; Trinh Van Giap; Le Ba Thuan; Vu Tien Ha

2014-01-01

Following the Contract No.19/HD/NVCB dated July 10, 2013 signed by the President of Vietnam Atomic Energy Institute (VINATOM), an additional ministerial Project was approval by the Decision No. 526/QD-VNLNT dated July 8, 2013 by the VINATOM President in order to implement an important task for VINATOM. This project was implemented by the Institute for Nuclear Science and Technology (INST) in Hanoi as management organization and VINATOM as the owner of project results. Main objectives of this Project are to support national budget for implementing to collected the general report from previous projects which are relevant to CNEST and new research reactor, IAEA guidance documents, documents provided by ROSATOM in seminars in 2010, 2012 and 2013, report from expert visits of Ministry of Science and Technology and completed the general report about the construction project of CNEST. (author)

Science and students: Yucca Mountain project's education outreach program

International Nuclear Information System (INIS)

Gil, A.V.; Larkin, E.L.; Reilly, B.; Austin, P.

1992-01-01

The U.S. Department of Energy (DOE) is very concerned about the lack of understanding of basic science. Increasingly, critical decisions regarding the use of energy, technology, and the environment are being made. A well-educated and science-literate public is vital to the success of these decisions. Science education and school instruction are integral parts of the DOE's public outreach program on the Yucca Mountain Site Characterization Project (YMP). Project staff and scientists speak to elementary, junior high, high school, and university students, accepting all speaking invitations. The objectives of this outreach program include the following: (1) educating Nevada students about the concept of a high-level nuclear waste repository; (2) increasing awareness of energy and environmental issues; (3) helping students understand basic concepts of earth science and geology in relation to siting a potential repository; and (4) giving students information about careers in science and engineering

The Communication in Science Inquiry Project (CISIP): A Project to Enhance Scientific Literacy through the Creation of Science Classroom Discourse Communities

Science.gov (United States)

Baker, Dale R.; Lewis, Elizabeth B.; Purzer, Senay; Watts, Nievita Bueno; Perkins, Gita; Uysal, Sibel; Wong, Sissy; Beard, Rachelle; Lang, Michael

2009-01-01

This study reports on the context and impact of the Communication in Science Inquiry Project (CISIP) professional development to promote teachers' and students' scientific literacy through the creation of science classroom discourse communities. The theoretical underpinnings of the professional development model are presented and key professional…

"In the Footsteps of Alexander the Great" PBS Series. Teacher's Guide.

Science.gov (United States)

Corporation for Public Broadcasting, Washington, DC.

This teacher's guide correlates with the Public Broadcasting Service (PBS) television series "In the Footsteps of Alexander the Great" hosted by historian Michael Wood. The four episodes of the series are entitled: "Son of God"; "Lord of Asia"; "Across the Hindu Kush"; and "To the Ends of the…

Translational Science Project Team Managers: Qualitative Insights and Implications from Current and Previous Postdoctoral Experiences.

Science.gov (United States)

Wooten, Kevin C; Dann, Sara M; Finnerty, Celeste C; Kotarba, Joseph A

2014-07-01

The development of leadership and project management skills is increasingly important to the evolution of translational science and team-based endeavors. Team science is dependent upon individuals at various stages in their careers, inclusive of postdocs. Data from case histories, as well as from interviews with current and former postdocs, and those supervising postdocs, indicate six essential tasks required of project managers in multidisciplinary translational teams, along with eight skill-related themes critical to their success. To optimize the opportunities available and to ensure sequential development of team project management skills, a life cycle model for the development of translational team skills is proposed, ranging from graduate trainees, postdocs, assistant professors, and finally to mature scientists. Specific goals, challenges and project management roles and tasks are recommended for each stage for the life cycle.

Shell’s use of science in de-risking projects

CSIR Research Space (South Africa)

Rossouw, N

2017-10-01

Full Text Available This presentation discusses Shell’s use of science in de-risking projects. The presentation includes examples of applying science in the De-Risking process, supporting scientific research and De-Risking the Karoo Basin....

Enhanced charge collection and photocatalysis performance of CdS and PbS nanoclusters co-sensitized TiO{sub 2} porous film

Energy Technology Data Exchange (ETDEWEB)

Zhang, Miao; Xu, Yanyan; Gong, Zezhou; Tao, Jiajia [School of Physics & Material Science, Anhui University, Hefei 230601 (China); Sun, Zhaoqi, E-mail: szq@ahu.edu.cn [School of Physics & Material Science, Anhui University, Hefei 230601 (China); Lv, Jianguo [School of Electronic & Information Engineering, Hefei Normal University, Hefei, 230601 (China); National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 (China); Chen, Xiaoshuang [National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 (China); Jiang, Xishun [School of Physics & Material Science, Anhui University, Hefei 230601 (China); School of Mechanical & Electronic Engineering, Chuzhou University, Chuzhou, 239000 (China); He, Gang; Wang, Peihong; Meng, Fanming [School of Physics & Material Science, Anhui University, Hefei 230601 (China)

2015-11-15

A novel translucent TiO{sub 2} porous film was prepared through etched method. The CdS, PbS and CdS/PbS nanoclusters were imbedded on TiO{sub 2} porous film by successive ionic layer adsorption and reaction method. Microstructure, morphology, optical and photoelectron-chemical properties of the as-synthesized thin films were investigated systematically. XRD and morphology analysis showed that PbS or CdS nanoclusters have been attached to the TiO{sub 2} porous films. It was found that the energy band gap of TiO{sub 2} porous film decreased from 3.46 to 3.2 eV after sensitized with nanoclusters. The photocurrent density of ITO/TiO{sub 2} photoelectrode increased from 0.017 to 0.28 mA/cm{sup 2} after co-sensitized with CdS and PbS nanoclusters. Besides, the photoelectrode sensitized with two sorts of nanoclusters showed evident higher photocurrent density than which sensitized just one sort of nanoclusters. The photocurrent density of ITO/TiO{sub 2}/PbS and TO/TiO{sub 2}/CdS photoelectrode was 0.11 mA/cm{sup 2} and 0.22 mA/cm{sup 2} respectively. 0.28 mA/cm{sup 2} can be obtained by ITO/TiO{sub 2}/CdS/PbS photoelectrode. The results showed that the optical and photoelectrochemistry properties and phtotcatalysis performance of TiO{sub 2} porous film were greatly improved by co-sensitized with CdS and PbS nanoclusters. - Graphical abstract: When CdS and PbS were brought in the cascade structure, such a Fermi level alignment causes upward and downward shifts of the band edges for PbS and CdS, respectively. Therefore the resulting band edges for the ITO/TiO{sub 2}/CdS/PbS devices are inferred to have a stepwise structure. The elevated conduction band edge of PbS provides a higher driving force for the injection of photogenerated electrons from PbS to CdS as well as the injection of excited holes from CdS to PbS. Such a structure offers efficient separation and transport of the excited electrons and holes. - Highlights: • Ti films were obtained from direct current

Social Science Methods Used in the RESTORE Project

Science.gov (United States)

Lynne M. Westphal; Cristy Watkins; Paul H. Gobster; Liam Heneghan; Kristen Ross; Laurel Ross; Madeleine Tudor; Alaka Wali; David H. Wise; Joanne Vining; Moira. Zellner

2014-01-01

The RESTORE (Rethinking Ecological and Social Theories of Restoration Ecology) project is an interdisciplinary, multi-institutional research endeavor funded by the National Science Foundation's Dynamics of Coupled Natural Human Systems program. The goal of the project is to understand the links between organizational type, decision making processes, and...

Environmental Management Integration Project/Mixed Waste Focus Area Partnership

International Nuclear Information System (INIS)

Gombert, D.; Kristofferson, K.; Cole, L.

1999-01-01

On January 16, 1998, the Assistant Secretary for the Environmental Management (EM) Program at the Department of Energy, issued DOE-Idaho the Program Integration and Systems Engineering Guidance for Fiscal Year 1998, herein called Guidance, which directed that program integration tasks be performed for all EM program areas. This guidance directed the EM Integration team, as part of the Task 1, to develop baseline waste and material disposition maps which are owned by the site Project Baseline Summary (PBS) manager. With these baselines in place Task 2 gave direction to link Science and Technology activities to the waste and material stream supported by that technology. This linkage of EM Program needs with the OST activities supports the DOE goal of maximizing cleanup at DOE sites by 2006 and provides a defensible science and technology program. Additionally, this linkage is a valuable tool in the integration of the waste and material disposition efforts for the DOE complex

Sulfide precursor concentration and lead source effect on PbS thin films properties

Energy Technology Data Exchange (ETDEWEB)

Beddek, L.; Messaoudi, M.; Attaf, N. [Laboratoire Couche Minces et Interfaces, Université frères Mentouri Constantine, 25000, Constantine (Algeria); Aida, M.S., E-mail: aida_salah2@yahoo.fr [Laboratoire Couche Minces et Interfaces, Université frères Mentouri Constantine, 25000, Constantine (Algeria); Bougdira, J. [Université de Lorraine, Institut Jean Lamour UMR 7198, Vandoeuvre 54506 (France)

2016-05-05

Lead sulfide (PbS) thin films were synthesized using chemical bath deposition (CBD). Bath solutions are formed of various concentrations of thiourea, sulfide source, ranged from 0.6 to 1.2 M and two different salts as Pb source (lead acetate and lead nitrate). From the growth mechanism, we inferred that PbS is formed through the ion by ion process when using acetate lead source, while, using nitrate source yields to films growth through the complex-decomposition process. Due to the difference in the involved growth process, lead acetate produces films with larger crystallite size (from 4 to 16 nm), smooth and dense films. However, lead nitrate produces rough films with smaller crystallite size (from 1 to 4 nm). Increasing the thiourea concentration results in crystallinity improvement when using lead acetate and, oppositely, in crystallinity degradation when using lead nitrate. Due to the quantum effect caused by the small crystallite sizes, the films optical gap is varied from 0.5 to 0.9 eV. - Highlights: • PbS thin films were synthesized by chemical bath deposition. • Ion by ion is the growth process when using the acetate lead source. • Deposition process is by complex-decomposition when using nitrate source. • Lead acetate yields to dense films with larger crystallite size. • Lead nitrate produces rough films with smaller crystallite size.

Sulfide precursor concentration and lead source effect on PbS thin films properties

International Nuclear Information System (INIS)

Beddek, L.; Messaoudi, M.; Attaf, N.; Aida, M.S.; Bougdira, J.

2016-01-01

Lead sulfide (PbS) thin films were synthesized using chemical bath deposition (CBD). Bath solutions are formed of various concentrations of thiourea, sulfide source, ranged from 0.6 to 1.2 M and two different salts as Pb source (lead acetate and lead nitrate). From the growth mechanism, we inferred that PbS is formed through the ion by ion process when using acetate lead source, while, using nitrate source yields to films growth through the complex-decomposition process. Due to the difference in the involved growth process, lead acetate produces films with larger crystallite size (from 4 to 16 nm), smooth and dense films. However, lead nitrate produces rough films with smaller crystallite size (from 1 to 4 nm). Increasing the thiourea concentration results in crystallinity improvement when using lead acetate and, oppositely, in crystallinity degradation when using lead nitrate. Due to the quantum effect caused by the small crystallite sizes, the films optical gap is varied from 0.5 to 0.9 eV. - Highlights: • PbS thin films were synthesized by chemical bath deposition. • Ion by ion is the growth process when using the acetate lead source. • Deposition process is by complex-decomposition when using nitrate source. • Lead acetate yields to dense films with larger crystallite size. • Lead nitrate produces rough films with smaller crystallite size.

Student and Faculty Outcomes of Undergraduate Science Research Projects by Geographically Dispersed Students

Science.gov (United States)

Shaw, Lawton; Kennepohl, Dietmar

2013-01-01

Senior undergraduate research projects are important components of most undergraduate science degrees. The delivery of such projects in a distance education format is challenging. Athabasca University (AU) science project courses allow distance education students to complete research project courses by working with research supervisors in their…

The Effect of Environmental Science Projects on Students' Environmental Knowledge and Science Attitudes

Science.gov (United States)

Al-Balushi, Sulaiman M.; Al-Aamri, Shamsa S.

2014-01-01

The current study explores the effectiveness of involving students in environmental science projects for their environmental knowledge and attitudes towards science. The study design is a quasi-experimental pre-post control group design. The sample was 62 11th-grade female students studying at a public school in Oman. The sample was divided into…

Using design science in educational technology research projects

Directory of Open Access Journals (Sweden)

Susan M. Chard

2017-12-01

Full Text Available Design science is a research paradigm where the development and evaluation of a technology artefact is a key contribution. Design science is used in many domains and this paper draws on those domains to formulate a generic structure for design science research suitable for educational technology research projects. The paper includes guidelines for writing proposals using the design science research methodology for educational technology research and presents a generic research report structure. The paper presents ethical issues to consider in design science research being conducted in educational settings and contributes guidelines for assessment when the research contribution involves the creation of a technology artefact.

Selling science 2.0: What scientific projects receive crowdfunding online?

Science.gov (United States)

Schäfer, Mike S; Metag, Julia; Feustle, Jessica; Herzog, Livia

2016-09-19

Crowdfunding has emerged as an additional source for financing research in recent years. The study at hand identifies and tests explanatory factors influencing the success of scientific crowdfunding projects by drawing on news value theory, the "reputation signaling" approach, and economic theories of online payment. A standardized content analysis of 371 projects on English- and German-language platforms reveals that each theory provides factors influencing crowdfunding success. It shows that projects presented on science-only crowdfunding platforms have a higher success rate. At the same time, projects are more likely to be successful if their presentation includes visualizations and humor, the lower their targeted funding is, the less personal data potential donors have to relinquish and the more interaction between researchers and donors is possible. This suggests that after donors decide to visit a scientific crowdfunding platform, factors unrelated to science matter more for subsequent funding decisions, raising questions about the potential and implications of crowdfunding science. © The Author(s) 2016.

37 CFR 253.4 - Performance of musical compositions by PBS, NPR and other public broadcasting entities engaged in...

Science.gov (United States)

2010-07-01

... background or theme music in a PBS program: 2003-2007 $56.81 (3) For performance of such a work in a feature... music in a program of a station of PBS: 2003-2007 $4.04 (5) For the performance of such a work in a... theme music in an NPR program: 2003-2007 $5.51 (7) For the performance of such a work in a feature...

37 CFR 381.4 - Performance of musical compositions by PBS, NPR and other public broadcasting entities engaged in...

Science.gov (United States)

2010-07-01

... background or theme music in a PBS program: 2008-2012 $57.66 (3) For performance of such a work in a feature... music in a program of a station of PBS: 2008-2012 $4.10 (5) For the performance of such a work in a... theme music in an NPR program: 2008-2012 $5.59 (7) For the performance of such a work in a feature...

Corrosion of experimental magnesium alloys in blood and PBS: A gravimetric and microscopic evaluation

Energy Technology Data Exchange (ETDEWEB)

Schille, Ch., E-mail: Christine.Schille@med.uni-tuebingen.de [University Hospital Tuebingen, Center for Dentistry, Oral Medicine and Maxillofacial Surgery, Section Medical Materials and Technology, Osianderstr. 2-8, D-72076 Tuebingen (Germany); Braun, M.; Wendel, H.P. [University Hospital Tuebingen, Div. Congenital and Paediatric Cardiac Surgery, University Children' s Hospital, Tuebingen, Germany, Calwerstr. 7/1, D-72076 Tuebingen (Germany); Scheideler, L. [University Hospital Tuebingen, Center for Dentistry, Oral Medicine and Maxillofacial Surgery, Section Medical Materials and Technology, Osianderstr. 2-8, D-72076 Tuebingen (Germany); Hort, N. [GKSS Research Centre, Institute of Materials Research, Max-Planck-Str. 1, D-21502 Geesthacht (Germany); Reichel, H.-P. [Weissensee Company, Buergermeister-Ebert-Str. 30-32, D-36124 Eichenzell (Germany); Schweizer, E.; Geis-Gerstorfer, J. [University Hospital Tuebingen, Center for Dentistry, Oral Medicine and Maxillofacial Surgery, Section Medical Materials and Technology, Osianderstr. 2-8, D-72076 Tuebingen (Germany)

2011-12-15

Highlights: Black-Right-Pointing-Pointer Corrosion of eight Mg-based Biomaterials was tested in saline and human blood. Black-Right-Pointing-Pointer Corrosion behaviour in physiological saline and in blood was entirely different. Black-Right-Pointing-Pointer Al and Zn had the highest influence on corrosion behaviour in both electrolytes. Black-Right-Pointing-Pointer MgAl9 and MgAl9Zn1 showed least corrosion in human whole blood. Black-Right-Pointing-Pointer Tests in buffered corrosion media are not sufficient to predict corrosion in vivo. - Abstract: Corrosion tests for medical materials are often performed in simulated body fluids (SBF). When SBF are used for corrosion measurement, the open question is, how well they match the conditions in the human body. The aim of the study was to compare the corrosion behaviour of different experimental magnesium alloys in human whole blood and PBS{sup minus} (phosphate buffered saline w/o Ca and Mg) as a simulated body fluid by gravimetric weight measurements and microscopic evaluation. Eight different experimental magnesium alloys, containing neither Mn nor other additives, were manufactured. With these alloys, a static immersion test in PBS{sup minus} and a dynamic test using the Chandler-loop model with human whole blood over 6 h were performed. During the static immersion test, the samples were weighed every hour. During the dynamic test, the specimens were weighed before and after the 6 h incubation period in the Chandler-loop. From both tests, the total mass change was calculated for each alloy and the values were compared. Additionally, microscopic pictures from the samples were taken at the end of the test period. All alloys showed different corrosion behaviour in both tests, especially the alloys with high aluminium content, MgAl9 and MgAl9Zn1. Generally, alloys in PBS showed a weight gain due to generation of a microscopically visible corrosion layer, while in the blood test system a more or less distinct weight

78 FR 32637 - Science and Technology Reinvention Laboratory Personnel Management Demonstration Project...

Science.gov (United States)

2013-05-31

..., Science and Technology Reinvention Laboratory Personnel Management Demonstration Project, Department of... DEPARTMENT OF DEFENSE Office of the Secretary Science and Technology Reinvention Laboratory Personnel Management Demonstration Project, Department of the Army, Army Research, Development and...

Interfacial dynamic surface traps of lead sulfide (PbS) nanocrystals: test-platform for interfacial charge carrier traps at the organic/inorganic functional interface

Science.gov (United States)

Kim, Youngjun; Ko, Hyungduk; Park, Byoungnam

2018-04-01

Nanocrystal (NC) size and ligand dependent dynamic trap formation of lead sulfide (PbS) NCs in contact with an organic semiconductor were investigated using a pentacene/PbS field effect transistor (FET). We used a bilayer pentacene/PbS FET to extract information of the surface traps of PbS NCs at the pentacene/PbS interface through the field effect-induced charge carrier density measurement in the threshold and subthreshold regions. PbS size and ligand dependent trap properties were elucidated by the time domain and threshold voltage measurements in which threshold voltage shift occurs by carrier charging and discharging in the trap states of PbS NCs. The observed threshold voltage shift is interpreted in context of electron trapping through dynamic trap formation associated with PbS NCs. To the best of our knowledge, this is the first demonstration of the presence of interfacial dynamic trap density of PbS NC in contact with an organic semiconductor (pentacene). We found that the dynamic trap density of the PbS NC is size dependent and the carrier residence time in the specific trap sites is more sensitive to NC size variation than to NC ligand exchange. The probing method presented in the study offers a means to investigate the interfacial surface traps at the organic-inorganic hetero-junction, otherwise understanding of the buried surface traps at the functional interface would be elusive.

Development and Validation of a Project Package for Junior Secondary School Basic Science

Science.gov (United States)

Udofia, Nsikak-Abasi

2014-01-01

This was a Research and Developmental study designed to develop and validate projects for Junior Secondary School Basic Science instruction and evaluation. The projects were developed using the project blueprint and sent for validation by experts in science education and measurement and evaluation; using a project validation scale. They were to…

Building Bridges between Science Courses Using Honors Organic Chemistry Projects

Science.gov (United States)

Hickey, Timothy; Pontrello, Jason

2016-01-01

Introductory undergraduate science courses are traditionally offered as distinct units without formalized student interaction between classes. To bridge science courses, the authors used three Honors Organic Chemistry projects paired with other science courses. The honors students delivered presentations to mainstream organic course students and…

The NPOESS Preparatory Project Science Data Segment: Brief Overview

Science.gov (United States)

Schweiss, Robert J.; Ho, Evelyn; Ullman, Richard; Samadi, Shahin

2006-01-01

The NPOESS Preparatory Project (NPP) provides remotely-sensed land, ocean, atmospheric, ozone, and sounder data that will serve the meteorological and global climate change scientific communities while also providing risk reduction for the National Polar-orbiting Operational Environmental Satellite System (NPOESS), the U.S. Government s future low-Earth orbiting satellite system monitoring global weather and environmental conditions. NPOESS and NPP are a new era, not only because the sensors will provide unprecedented quality and volume of data but also because it is a joint mission of three federal agencies, NASA, NOAA, and DoD. NASA's primary science role in NPP is to independently assess the quality of the NPP science and environmental data records. Such assessment is critical for making NPOESS products the best that they can be for operational use and ultimately for climate studies. The Science Data Segment (SDS) supports science assessment by assuring the timely provision of NPP data to NASA s science teams organized by climate measurement themes. The SDS breaks down into nine major elements, an input element that receives data from the operational agencies and acts as a buffer, a calibration analysis element, five elements devoted to measurement based quality assessment, an element used to test algorithmic improvements, and an element that provides overall science direction. This paper will describe how the NPP SDS will leverage on NASA experience to provide a mission-reliable research capability for science assessment of NPP derived measurements.

COSEE-AK Ocean Science Fairs: A Science Fair Model That Grounds Student Projects in Both Western Science and Traditional Native Knowledge

Science.gov (United States)

Dublin, Robin; Sigman, Marilyn; Anderson, Andrea; Barnhardt, Ray; Topkok, Sean Asiqluq

2014-01-01

We have developed the traditional science fair format into an ocean science fair model that promoted the integration of Western science and Alaska Native traditional knowledge in student projects focused on the ocean, aquatic environments, and climate change. The typical science fair judging criteria for the validity and presentation of the…

Visualization and characterization of users in a citizen science project

Science.gov (United States)

Morais, Alessandra M. M.; Raddick, Jordan; Coelho dos Santos, Rafael D.

2013-05-01

Recent technological advances allowed the creation and use of internet-based systems where many users can collaborate gathering and sharing information for specific or general purposes: social networks, e-commerce review systems, collaborative knowledge systems, etc. Since most of the data collected in these systems is user-generated, understanding of the motivations and general behavior of users is a very important issue. Of particular interest are citizen science projects, where users without scientific training are asked for collaboration labeling and classifying information (either automatically by giving away idle computer time or manually by actually seeing data and providing information about it). Understanding behavior of users of those types of data collection systems may help increase the involvement of the users, categorize users accordingly to different parameters, facilitate their collaboration with the systems, design better user interfaces, and allow better planning and deployment of similar projects and systems. Behavior of those users could be estimated through analysis of their collaboration track: registers of which user did what and when can be easily and unobtrusively collected in several different ways, the simplest being a log of activities. In this paper we present some results on the visualization and characterization of almost 150.000 users with more than 80.000.000 collaborations with a citizen science project - Galaxy Zoo I, which asked users to classify galaxies' images. Basic visualization techniques are not applicable due to the number of users, so techniques to characterize users' behavior based on feature extraction and clustering are used.

Project ALERT: Forging New Partnerships to Improve Earth System Science Education for Pre-Service and In-Service Teachers

Science.gov (United States)

Metzger, E. P.; Ambos, E. L.; Ng, E. W.; Skiles, J.; Simila, G.; Garfield, N.

2002-05-01

workshops have been enriched by the incorporation of earth and space science information and curricular materials from NASA. In addition, visits to Ames Research Center have given BAESI participants an opportunity to explore the Educator Resource Center, learn about NASA's programs for teachers and students, and experience presentations by NASA scientists engaged in cutting edge research about the earth system. Project ALERT demonstrates the power of a state-based partnership that unites scientists and educators with diverse perspectives and strengths in a synergistic effort to improve science education.

Real Life Science with Dandelions and Project BudBurst

Directory of Open Access Journals (Sweden)

Katherine A. Johnson

2015-12-01

Full Text Available Project BudBurst is a national citizen-science project that tracks bloom times and other phenological data for plants across the country. Data from Project BudBurst are being used to measure the effects of climate change. Students can participate in this project by watching any of the plants on the list, including the common dandelion, which makes the program easy and accessible to everyone.

Real Life Science with Dandelions and Project BudBurst.

Science.gov (United States)

Johnson, Katherine A

2016-03-01

Project BudBurst is a national citizen-science project that tracks bloom times and other phenological data for plants across the country. Data from Project BudBurst are being used to measure the effects of climate change. Students can participate in this project by watching any of the plants on the list, including the common dandelion, which makes the program easy and accessible to everyone. Journal of Microbiology & Biology Education.

Results of Needs Assessments Related to Citizen Science Projects

Science.gov (United States)

Buxner, Sanlyn; Bracey, Georgia; Glushko, Anna; Bakerman, Maya; Gay, Pamela L.; CosmoQuest Team

2017-01-01

The CosmoQuest Virtual Research Facility invites the public and classrooms to participate in NASA Science Mission Directorate related research that leads to publishable results and data catalogues. One of the main goals of the project is to support professional scientists in doing science and the general public--including parents, children, teachers, and students--in learning and doing science. Through the effort, the CosmoQuest team is developing a variety of supports and opportunities to support the doing and teaching of science. To inform our efforts, we have implemented a set of needs surveys to assess the needs of our different audiences. These surveys are being used to understand the interests, motivations, resources, challenges and demographics of our growing CosmoQuest community and others interested in engaging in citizen science projects. The surveys include those for teachers, parents, adult learners, planetarium professionals, subject matter experts (SMEs), and the general public. We will share the results of these surveys and discuss the implications of the results for broader education and outreach programs.

Effect of Maleated Compatibiliser (PBS-g-MA) Addition on the Flexural Properties and Water Absorption of Poly(butylene succinate)/ kenaf Bast Fibre Composites

International Nuclear Information System (INIS)

Ahmad, M.Z.T.; Mohd, Z.A.M.; Mat, R.T.; Ahmad, M.Z.T.; Mohd, Z.A.I.; Mat, R.T.; Rahim, S.

2013-01-01

Poly(butylene succinate) (PBS) composites with 30 wt.% loading of kenaf bast fibre (KBF) were compatibilised with 5 wt. % maleated PBS (PBS-g-MA). The maleic anhydride (MA) concentration in the compatibiliser was either 3, 5, 7 or 10 phr. In general, the compatibilised composites showed better flexural properties than the un-compatibilised composite. The highest increment in the flexural strength and modulus of 12.7 and 8.9 %, respectively, were obtained with the addition of PBS-g-MA with MA concentration of 5 phr. Compatibilised and un-compatibilised PBS/ KBF composites were immersed in distilled water for 90 days. The absorption of water by all the composites was observed to follow Ficks law. The equilibrium moisture content, M m , of the composites with PBS-g-MA at 3, 5 and 7 phr of MA concentrations was lower than that of the un-compatibilised composite due to improved fiber-matrix interfacial adhesion and reduction of voids content. Both un-compatibilised and compatibilised composites showed dimensional instability after the water absorption. This was probably due to the degradation of the fibre-matrix interfacial adhesion and fibre integrity. The flexural properties of these composites decreased after the water absorption. After re-drying only some of the flexural properties were recovered from plasticizing effect of water. (author)

Comb-e-Chem: an e-science research project

OpenAIRE

Frey, Jeremy G.

2003-01-01

The background to the Comb-e-Chem e-Science pilot project funded under the UK -Science Programme is presented and the areas being addresses within chemistry and more specifically combinatorial chemistry are disucssed. The ways in which the ideas underlying the application of computer technology can improve the production, analysis and dissemination of chemical information and knowledge in a collaborative environment are discussed.

Project TIMS (Teaching Integrated Math/Science)

Science.gov (United States)

Edwards, Leo, Jr.

1993-01-01

The goal of this project is to increase the scientific knowledge and appreciation bases and skills of pre-service and in-service middle school teachers, so as to impact positively on teaching, learning, and student retention. This report lists the objectives and summarizes the progress thus far. Included is the working draft of the TIMS (Teaching Integrated Math/Science) curriculum outline. Seven of the eight instructional subject-oriented modules are also included. The modules include informative materials and corresponding questions and educational activities in a textbook format. The subjects included here are the universe and stars; the sun and its place in the universe; our solar system; astronomical instruments and scientific measurements; the moon and eclipses; the earth's atmosphere: its nature and composition; and the earth: directions, time, and seasons. The module not included regards winds and circulation.

WISE Science: Web-based Inquiry in the Classroom. Technology, Education--Connections

Science.gov (United States)

Slotta, James D.; Linn, Marcia C.

2009-01-01

This book shares the lessons learned by a large community of educational researchers and science teachers as they designed, developed, and investigated a new technology-enhanced learning environment known as WISE: The Web-Based Inquiry Science Environment. WISE offers a collection of free, customizable curriculum projects on topics central to the…

Project BudBurst: Continental-scale citizen science for all seasons

Science.gov (United States)

Henderson, S.; Newman, S. J.; Ward, D.; Havens-Young, K.; Alaback, P.; Meymaris, K.

2011-12-01

Project BudBurst's (budburst.org) recent move to the National Ecological Observatory Network (NEON) has benefitted both programs. NEON has been able to use Project BudBurst as a testbed to learn best practices, network with experts in the field, and prototype potential tools for engaging people in continental-scale ecology as NEON develops its citizen science program. Participation in Project BudBurst has grown significantly since the move to NEON. Project BudBurst is a national citizen science initiative designed to engage the public in observations of phenological (plant life cycle) events that raise awareness of climate change, and create a cadre of informed citizen scientists. Citizen science programs such as Project BudBurst provide the opportunity for students and interested laypersons to actively participate in scientific research. Such programs are important not only from an educational perspective, but because they also enable scientists to broaden the geographic and temporal scale of their observations. The goals of Project BudBurst are to 1) increase awareness of phenology as an area of scientific study; 2) Increase awareness of the impacts of changing climates on plants at a continental-scale; and 3) increase science literacy by engaging participants in the scientific process. From its 2008 launch in February, this on-line educational and data-entry program, engaged participants of all ages and walks of life in recording the timing of the leafing and flowering of wild and cultivated species found across the continent. Thus far, thousands of participants from all 50 states have submitted data. This presentation will provide an overview of Project BudBurst and will report on the results of the 2010 field campaign and discuss plans to expand Project BudBurst in 2012 including the use of mobile phones applications for data collection and reporting from the field. Project BudBurst is co-managed by the National Ecological Observatory Network and the Chicago

Project Stakeholder Management: A Case Study of a Brazilian Science Park

Directory of Open Access Journals (Sweden)

Antônio Carlos Pacagnella Júnior

2015-07-01

Full Text Available The stakeholder management has been a topic increasingly discussed in the literature about project management, though still existing, large gaps to be filled, especially in complex projects such as the implementation of science parks. Thus, in this paper is presented a case of a Brazilian Science Park which shows how the management team of the project identified key stakeholders and established strategies for engagement and collaboration that sought to increase their engagement, get resources and make use of specific capabilities that were required during the lifecycle of the project to the reaching of its goals.

The Effect of Substrate Temperature on the Structural Properties of Spray Pyrolysed Lead Sulphide (PbS Thin Films

Directory of Open Access Journals (Sweden)

Mohammad G. Faraj

2014-09-01

Full Text Available Lead sulphide (PbS films were prepared by the chemical spray pyrolysis technique using a solution of Lead nitrate and thiourea. PbS films were deposited (prepared on glass substrate at varied temperature (250-350 oC. Effects of substrate temperature on the structural characteristics of the films were studied. The X-ray diffraction patterns’ results reveal that the all of PbS films have a face centered cubic structure. The X-ray diffraction study showed that irrespective of substrate temperature all the films exhibits a preferred orientation along the (200 plane. The degree of preferred orientation increased with the substrate temperature. It was observed that the increase of the substrate temperature increase the diffraction peak intensity of (200 plane which resulted in increase in grain size and good crystallinity of the films.

THEMES, DREAMS AND REAUTY: THE SCIENCE PROJECT ...

African Journals Online (AJOL)

Science Education Project (SEP) is a non-profit making educational trust ... us that many of them fail to survive the rigours of the school and ... environment) emphasis will be placed on in-service training and ... The 'status quo' is safe, everyone.

Probing surface states in PbS nanocrystal films using pentacene field effect transistors: controlling carrier concentration and charge transport in pentacene.

Science.gov (United States)

Park, Byoungnam; Whitham, Kevin; Bian, Kaifu; Lim, Yee-Fun; Hanrath, Tobias

2014-12-21

We used a bilayer field effect transistor (FET) consisting of a thin PbS nanocrystals (NCs) film interfaced with vacuum-deposited pentacene to probe trap states in NCs. We interpret the observed threshold voltage shift in context of charge carrier trapping by PbS NCs and relate the magnitude of the threshold voltage shift to the number of trapped carriers. We explored a series of NC surface ligands to modify the interface between PbS NCs and pentacene and demonstrate the impact of interface chemistry on charge carrier density and the FET mobility in a pentacene FET.

Learning about the Earth through Societally-relevant Interdisciplinary Research Projects: the Honours Integrated Science Program at McMaster

Science.gov (United States)

Eyles, C.; Symons, S. L.; Harvey, C. T.

2016-12-01

Students in the Honours Integrated Science (iSci) program at McMaster University (Hamilton, Ontario, Canada) learn about the Earth through interdisciplinary research projects that focus on important societal issues. The iSci program is a new and innovative undergraduate program that emphasizes the links between scientific disciplines and focuses on learning through research and the development of scientific communication skills. The program accepts up to 60 students each year and is taught by a team of 18 instructors comprising senior and junior faculty, post-doctoral fellows, a lab coordinator, instructional assistant, a librarian and library staff, and an administrator. The program is designed around a pedagogical model that emphasizes hands-on learning through interdisciplinary research (Research-based Integrated Education: RIE) and is mostly project-based and experiential. In their freshman year students learn fundamental Earth science concepts (in conjunction with chemistry, physics, mathematics and biology) through research projects focused on environmental contamination, interplanetary exploration, the effect of drugs on the human body and environment, sustainable energy, and cancer. In subsequent years they conduct research on topics such as the History of the Earth, Thermodynamics, Plant-Animal Interactions, Wine Science, Forensics, and Climate Change. The iSci program attracts students with a broad interest in science and has been particularly effective in directing high quality students into the Earth sciences as they are introduced to the discipline in their first year of study through research projects that are interesting and stimulating. The structure of the iSci program encourages consideration of geoscientific applications in a broad range of societally relevant research projects; these projects are reviewed and modified each year to ensure their currency and ability to meet program learning objectives.

A novel polarization demodulation method using polarization beam splitter (PBS) for dynamic pressure sensor

Science.gov (United States)

Su, Yang; Zhou, Hua; Wang, Yiming; Shen, Huiping

2018-03-01

In this paper we propose a new design to demodulate polarization properties induced by pressure using a PBS (polarization beam splitter), which is different with traditional polarimeter based on the 4-detector polarization measurement approach. The theoretical model is established by Muller matrix method. Experimental results confirm the validity of our analysis. Proportional relationships and linear fit are found between output signal and applied pressure. A maximum sensitivity of 0.092182 mv/mv is experimentally achieved and the frequency response exhibits a <0.14 dB variation across the measurement bandwidth. The sensitivity dependence on incident SOP (state of polarization) is investigated. The simple and all-fiber configuration, low-cost and high speed potential make it promising for fiber-based dynamic pressure sensing.

Phase transformation and conductivity in nanocrystal PbS under pressure

DEFF Research Database (Denmark)

Jiang, Jianzhong; Gerward, Leif; Secco, R.

2000-01-01

The grain-size effect on the phase transition induced by pressure in PbS was studied by in situ high-pressure electrical resistance and synchrotron radiation x-ray powder diffraction measurements. The mean transition pressure of the B1-to-B16 phase transformation was found to be 6.3±1.3 GPa in 8...... in terms of a decrease of energy band gap with increasing pressure. ©2000 American Institute of Physics....

Ebola Crisis: Improving Science-Based Communication and Local ...

International Development Research Centre (IDRC) Digital Library (Canada)

As a long-term goal, the project aims to strengthen journalism associations in Africa through country and regional exchanges using a Web-based platform devoted to science and health journalism. This will help increase access to health knowledge and evidence, improve monitoring and reporting of priority health issues in ...

Collaborative Visualization Project: shared-technology learning environments for science learning

Science.gov (United States)

Pea, Roy D.; Gomez, Louis M.

1993-01-01

Project-enhanced science learning (PESL) provides students with opportunities for `cognitive apprenticeships' in authentic scientific inquiry using computers for data-collection and analysis. Student teams work on projects with teacher guidance to develop and apply their understanding of science concepts and skills. We are applying advanced computing and communications technologies to augment and transform PESL at-a-distance (beyond the boundaries of the individual school), which is limited today to asynchronous, text-only networking and unsuitable for collaborative science learning involving shared access to multimedia resources such as data, graphs, tables, pictures, and audio-video communication. Our work creates user technology (a Collaborative Science Workbench providing PESL design support and shared synchronous document views, program, and data access; a Science Learning Resource Directory for easy access to resources including two-way video links to collaborators, mentors, museum exhibits, media-rich resources such as scientific visualization graphics), and refine enabling technologies (audiovisual and shared-data telephony, networking) for this PESL niche. We characterize participation scenarios for using these resources and we discuss national networked access to science education expertise.

Electrochemical surface-enhanced Raman scattering measurement on ligand capped PbS quantum dots at gap of Au nanodimer

Science.gov (United States)

Li, Xiaowei; Minamimoto, Hiro; Murakoshi, Kei

2018-05-01

The vibrational characteristics of ligand-capped lead sulfide (PbS) quantum dots (QDs) were clarified via electrochemical surface-enhanced Raman spectroscopy (EC-SERS) using a hybridized system of gold (Au) nanodimers and PbS QDs under electrochemical potential control. Enhanced electromagnetic field caused by the coupling of QDs with plasmonic Au nanodimers allowed the characteristic behavior of the ligand oleic acid (OA) on the PbS QD surface to be detected under electrochemical potential control. Binding modes between the QDs and OA molecules were characterized using synchronous two-dimensional correlation spectra at distinct electrochemical potentials, confirming that the bidentate bridging mode was probably the most stable mode even under relatively negative potential polarization. Changes in binding modes and molecular orientations resulted in fluctuations in EC-SERS spectra. The present observations strongly recommend the validity of the QD-plasmonic nanostructure coupled system for sensitive molecular detection via EC-SERS.

The Use of Online Citizen-Science Projects to Provide Experiential Learning Opportunities for Nonmajor Science Students

Directory of Open Access Journals (Sweden)

Donna M. Kridelbaugh

2015-11-01

Full Text Available Citizen science is becoming even more accessible to the general public through technological advances in the development of mobile applications, facilitating information dissemination and data collection. With the advent of “big data,” many citizen-science projects designed to help researchers sift through piles of research data now exist entirely online, either in the form of playing a game or via other digital avenues. Recent trends in citizen science have also focused on “crowdsourcing” solutions from the general public to help solve societal issues, often requiring nothing more than brainstorming and a computer to submit ideas. Online citizen science thus provides an excellent platform to expand the accessibility of experiential learning opportunities for a broad range of nonmajor science students at institutions with limited resources (e.g., community colleges. I created an activity for a general microbiology lecture to engage students in hands-on experiences via participation in online citizen-science projects. The objectives of the assignment were for students to: 1 understand that everyone can be a scientist; 2 learn to be creative and innovative in designing solutions to health and science challenges; and 3 further practice science communication skills with a written report. This activity is designed for introductory science courses with nonmajor science students who have limited opportunities to participate in undergraduate research experiences.

A Project-Based Course on Newton's Laws for Talented Junior High-School Students

Science.gov (United States)

Langbeheim, Elon

2015-01-01

Research has shown that project-based learning promotes student interest in science and improves understanding of scientific content. Fostering student motivation is particularly important in accelerated science and technology programmes for talented students, which are often demanding and time-consuming. Current texts provide little guidance on…

A biotic game design project for integrated life science and engineering education.

Science.gov (United States)

Cira, Nate J; Chung, Alice M; Denisin, Aleksandra K; Rensi, Stefano; Sanchez, Gabriel N; Quake, Stephen R; Riedel-Kruse, Ingmar H

2015-03-01

Engaging, hands-on design experiences are key for formal and informal Science, Technology, Engineering, and Mathematics (STEM) education. Robotic and video game design challenges have been particularly effective in stimulating student interest, but equivalent experiences for the life sciences are not as developed. Here we present the concept of a "biotic game design project" to motivate student learning at the interface of life sciences and device engineering (as part of a cornerstone bioengineering devices course). We provide all course material and also present efforts in adapting the project's complexity to serve other time frames, age groups, learning focuses, and budgets. Students self-reported that they found the biotic game project fun and motivating, resulting in increased effort. Hence this type of design project could generate excitement and educational impact similar to robotics and video games.

Search for Spin Filtering By Electron Tunneling Through Ferromagnetic EuS Barriers in Pbs

Science.gov (United States)

Figielski, T.; Morawski, A.; Wosinski, T.; Wrotek, S.; Makosa, A.; Lusakowska, E.; Story, T.; Sipatov, A. Yu.; Szczerbakow, A.; Grasza, K.;

Opto-electronics of PbS quantum dot and narrow bandgap polymer blends

NARCIS (Netherlands)

Kahmann, Simon; Mura, Andrea; Protesescu, Loredana; Kovalenko, Maksym V.; Brabec, Christoph J.; Loi, Maria A.

2015-01-01

Here we report on the interaction between the narrow bandgap polymer [2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta-[2,1-b;3,4-b]dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT) and lead sulphide (PbS) colloidal quantum dots (CQDs) upon photoexcitation. We show that the presence of both materials

[Earth Science Technology Office's Computational Technologies Project

Science.gov (United States)

Fischer, James (Technical Monitor); Merkey, Phillip

2005-01-01

This grant supported the effort to characterize the problem domain of the Earth Science Technology Office's Computational Technologies Project, to engage the Beowulf Cluster Computing Community as well as the High Performance Computing Research Community so that we can predict the applicability of said technologies to the scientific community represented by the CT project and formulate long term strategies to provide the computational resources necessary to attain the anticipated scientific objectives of the CT project. Specifically, the goal of the evaluation effort is to use the information gathered over the course of the Round-3 investigations to quantify the trends in scientific expectations, the algorithmic requirements and capabilities of high-performance computers to satisfy this anticipated need.

From neutron science project to J-PARC. From the viewpoint of JAERI

International Nuclear Information System (INIS)

Oyama, Yukio

2006-01-01

Japan Atomic Energy Research Institute (JAERI), at present Japan Atomic Energy Agency (JAEA), has been developing particle accelerators since its establishment in 1956 for obtaining basic data on the neutron. Also reactor-based neutron sciences have been developed at JAERI/JAEA. Under the so-called omega project which was started in 1988, JAERI/JAEA has been conducting researches on Engineering Test Accelerator for the nuclear transmutation and has built a Basic Test Accelerator. In 1996, a special team for neutron science promotion was organized and pushed R and D works on proton accelerators, targets, neutron engineering, radiation safety and so on. Integration of proton accelerator projects at JAERI and KEK (Institute for High Energy Physics) was proposed in 1998, and both institutes agreed to establish a unified proton accelerator facility, J-PARC. JAEA is promoting the industrial application of neutrons. Also the research on nuclear transmutation at J-PARC, which is not endorsed yet, is an essential objective for JAEA. (K.Y.)

Participatory science and innovation for improved sanitation and hygiene: process and outcome evaluation of project SHINE, a school-based intervention in Rural Tanzania

OpenAIRE

Hetherington, Erin; Eggers, Matthijs; Wamoyi, Joyce; Hatfield, Jennifer; Manyama, Mange; Kutz, Susan; Bastien, Sheri

2017-01-01

Abstract Background Diarrheal disease is a major cause of mortality and morbidity in low and middle income countries with children being disproportionately affected. Project SHINE (Sanitation & Hygiene INnovation in Education) is a grassroots participatory science education and social entrepreneurship model to engage youth and the wider community in the development of sustainable strategies to improve sanitation and hygiene. Methods Based in rural and remote Tanzania, this pilot study engaged...

[Analysis of projects of schistosomiasis sponsored by National Science Foundation of China].

Science.gov (United States)

Wen-di, Zhou; Liang, Shi; Xue-Dan, Ke; Jie, Wang

2017-07-27

To summarize the present development by analysis of projects in schistosomiasis funded by National Science Foundation of China (NSFC). Based on the ISIS database of NFSC, the projects in the studies of schistosomiasis from 2005 to 2016 were analyzed. The distributions of sponsored numbers, amounts, types, agencies, disciplines and changes in research topics by means of network profiles were described. During the study period, 198 projects were funded by NSFC totally with 76.05 million yuan in which the general and youth projects were main types. The main sponsored agencies were research institutes and medical colleges. The top three fields sponsored were medical pathogenic microbes and infection, veterinary and medical immunology. The funding on schistosomiasis researches has a downward trend, but studies are continuing in depth. In this situation, innovative and interdisciplinary researches need to be encouraged to promote the development of schistosomiasis.

The 5E Instructional Model: A Learning Cycle Approach for Inquiry-Based Science Teaching

Science.gov (United States)

Duran, Lena Ballone; Duran, Emilio

2004-01-01

The implementation of inquiry-based teaching is a major theme in national science education reform documents such as "Project 2061: Science for All Americans" (Rutherford & Alhgren, 1990) and the "National Science Education Standards" (NRC, 1996). These reports argue that inquiry needs to be a central strategy of all…

U-Science (Invited)

Science.gov (United States)

Borne, K. D.

2009-12-01

The emergence of e-Science over the past decade as a paradigm for Internet-based science was an inevitable evolution of science that built upon the web protocols and access patterns that were prevalent at that time, including Web Services, XML-based information exchange, machine-to-machine communication, service registries, the Grid, and distributed data. We now see a major shift in web behavior patterns to social networks, user-provided content (e.g., tags and annotations), ubiquitous devices, user-centric experiences, and user-led activities. The inevitable accrual of these social networking patterns and protocols by scientists and science projects leads to U-Science as a new paradigm for online scientific research (i.e., ubiquitous, user-led, untethered, You-centered science). U-Science applications include components from semantic e-science (ontologies, taxonomies, folksonomies, tagging, annotations, and classification systems), which is much more than Web 2.0-based science (Wikis, blogs, and online environments like Second Life). Among the best examples of U-Science are Citizen Science projects, including Galaxy Zoo, Stardust@Home, Project Budburst, Volksdata, CoCoRaHS (the Community Collaborative Rain, Hail and Snow network), and projects utilizing Volunteer Geographic Information (VGI). There are also scientist-led projects for scientists that engage a wider community in building knowledge through user-provided content. Among the semantic-based U-Science projects for scientists are those that specifically enable user-based annotation of scientific results in databases. These include the Heliophysics Knowledgebase, BioDAS, WikiProteins, The Entity Describer, and eventually AstroDAS. Such collaborative tagging of scientific data addresses several petascale data challenges for scientists: how to find the most relevant data, how to reuse those data, how to integrate data from multiple sources, how to mine and discover new knowledge in large databases, how to

Project for the Space Science in Moscow State University of Geodesy and Cartography (MIIGAiK)

Science.gov (United States)

Semenov, M.; Oberst, J.; Malinnikov, V.; Shingareva, K.; Grechishchev, A.; Karachevtseva, I.; Konopikhin, A.

2012-04-01

Introduction: Based on the proposal call of the Government of Russian Federation 40 of international scientists came to Russia for developing and support-ing research capabilities of national educational institutions. Moscow State University of Geodesy and Cartography (MIIGAiK) and invited scientist Prof. Dr. Jurgen Oberst were awarded a grant to establish a capable research facility concerned with Planetary Geodesy, Cartography and Space Exploration. Objectives: The goals of the project are to build laboratory infrastructure, and suitable capability for MIIGAiK to participate in the planning, execution and analyses of data from future Russian planetary mis-sions and also to integrate into the international science community. Other important tasks are to develop an attractive work place and job opportunities for planetary geodesy and cartography students. For this purposes new MIIGAiK Extraterrestrial Laboratory (MExLab) was organized. We involved professors, researchers, PhD students in to the projects of Moon and planets exploration at the new level of Russian Space Science development. Main results: MExLab team prepare data for upcom-ing Russian space missions, such as LUNA-GLOB and LUNA-RESOURSE. We established cooperation with Russian and international partners (IKI, ESA, DLR, and foreign Universities) and actively participated in international conferences and workshops. Future works: For the future science development we investigated the old Soviet Archives and received the access to the telemetry data of the Moon rovers Lunokhod-1 and Lunokhod-2. That data will be used in education purposes and could be the perfect base for the analysis, development and support in new Russian and international missions and especially Moon exploration projects. MExLab is open to cooperate and make the consortiums for science projects for the Moon and planets exploration. Acknowledgement: Works are funded by the Rus-sian Government (Project name: "Geodesy, cartography and the

International Science Education: A Study of UNESCO Science Education Improvement Projects in Selected Anglophone Countries of Africa: Project Problems.

Science.gov (United States)

Nichter, Richard

1984-01-01

Discusses some of the problems faced by technical advisors implementing projects for the improvement of science education in Africa and reasons for these problems. Problem areas considered include underdevelopment, underestimating the process, finances, personality conflict and motivation, and opposition from key groups. (A list of major UNESCO…

Study of band gap and determination of size of PbS quantum dots synthesized by colloidal solution

Directory of Open Access Journals (Sweden)

M. S. Ghamsari

2005-03-01

Full Text Available   PbS semiconductor non-crystals have been synthesized in order to study the modification of their electronic structures and optical properties in relation to their size. The synthesis has been carried out by using the techniques of colloidal chemistry. Strong quantum confinement behavior has been observed based on the analysis of optical spectra of these particles. The average particle size approximated by x-ray line width and hyperbolic band model calculation. Heterogeneous broadening of optical spectrum is studied finally.

Size-dependent optical properties of colloidal PbS quantum dots.

Science.gov (United States)

Moreels, Iwan; Lambert, Karel; Smeets, Dries; De Muynck, David; Nollet, Tom; Martins, José C; Vanhaecke, Frank; Vantomme, André; Delerue, Christophe; Allan, Guy; Hens, Zeger

2009-10-27

We quantitatively investigate the size-dependent optical properties of colloidal PbS nanocrystals or quantum dots (Qdots), by combining the Qdot absorbance spectra with detailed elemental analysis of the Qdot suspensions. At high energies, the molar extinction coefficient epsilon increases with the Qdot volume d(3) and agrees with theoretical calculations using the Maxwell-Garnett effective medium theory and bulk values for the Qdot dielectric function. This demonstrates that quantum confinement has no influence on epsilon in this spectral range, and it provides an accurate method to calculate the Qdot concentration. Around the band gap, epsilon only increases with d(1.3), and values are comparable to the epsilon of PbSe Qdots. The data are related to the oscillator strength f(if) of the band gap transition and results agree well with theoretical tight-binding calculations, predicting a linear dependence of f(if) on d. For both PbS and PbSe Qdots, the exciton lifetime tau is calculated from f(if). We find values ranging between 1 and 3 mus, in agreement with experimental literature data from time-resolved luminescence spectroscopy. Our results provide a thorough general framework to calculate and understand the optical properties of suspended colloidal quantum dots. Most importantly, it highlights the significance of the local field factor in these systems.

Can citizen science enhance public understanding of science?

Science.gov (United States)

Bonney, Rick; Phillips, Tina B; Ballard, Heidi L; Enck, Jody W

2016-01-01

Over the past 20 years, thousands of citizen science projects engaging millions of participants in collecting and/or processing data have sprung up around the world. Here we review documented outcomes from four categories of citizen science projects which are defined by the nature of the activities in which their participants engage - Data Collection, Data Processing, Curriculum-based, and Community Science. We find strong evidence that scientific outcomes of citizen science are well documented, particularly for Data Collection and Data Processing projects. We find limited but growing evidence that citizen science projects achieve participant gains in knowledge about science knowledge and process, increase public awareness of the diversity of scientific research, and provide deeper meaning to participants' hobbies. We also find some evidence that citizen science can contribute positively to social well-being by influencing the questions that are being addressed and by giving people a voice in local environmental decision making. While not all citizen science projects are intended to achieve a greater degree of public understanding of science, social change, or improved science -society relationships, those projects that do require effort and resources in four main categories: (1) project design, (2) outcomes measurement, (3) engagement of new audiences, and (4) new directions for research. © The Author(s) 2015.

"Adotta scienza e arte nella tua classe": The results of a successfully teaching project which combines science with art⋆

Science.gov (United States)

Giansanti, S.

2015-03-01

The project called Adotta scienza e arte nella tua classe ("Adopt Science and Art in your class"), on the interconnection between science and art, has been addressed to the Italian secondary middle and high school involving more than 200 teachers and about 2200 students. The main purpose of this project is to make the young students aware of the strong link between science and art is a unique cultural and interdisciplinary occasion. To reach this goal, the Adotta project asked students to produce an artwork inspired by the interpretation of a quotation among a hundred commented quotes by physicists, mathematicians, scientist, writers, artists, accompanied by an original short sentence written by students themselves. More than 1000 artworks have been produced and collected in two galleries on Facebook. From their analysis emerges the students' feeling about science, which is usually associated to human brain, based on mathematical laws and related to technological progress, but it is also a powerful tool that should be responsibly used. This project also valorizes teachers' role in scientific education through activities that encourage students to recognize science in every aspect of their lives.

A biotic game design project for integrated life science and engineering education.

Directory of Open Access Journals (Sweden)

Nate J Cira

2015-03-01

Full Text Available Engaging, hands-on design experiences are key for formal and informal Science, Technology, Engineering, and Mathematics (STEM education. Robotic and video game design challenges have been particularly effective in stimulating student interest, but equivalent experiences for the life sciences are not as developed. Here we present the concept of a "biotic game design project" to motivate student learning at the interface of life sciences and device engineering (as part of a cornerstone bioengineering devices course. We provide all course material and also present efforts in adapting the project's complexity to serve other time frames, age groups, learning focuses, and budgets. Students self-reported that they found the biotic game project fun and motivating, resulting in increased effort. Hence this type of design project could generate excitement and educational impact similar to robotics and video games.

Disaster Relief and Emergency Medical Services Project (DREAMS TM): Clinical and Basic Science Projects

National Research Council Canada - National Science Library

Casscells, Ward

1999-01-01

DREAMS clinical and basic science projects complement the digital EMS effort by investigating the mechanisms of tissue injury in order to minimize the mortality and mortality of trauma and "natural...

Effective teaching in the contexts of Internet science projects: American and Russian teachers' perspectives of best practices

Science.gov (United States)

Mumma, Brian

Statement of the problem. Science education literature had agreed that an important goal in students' learning is the development of scientific and technological literacy. One effort that teachers have integrated into their practices for addressing this goal has been teaching within the contexts of Internet Science Projects. Greater awareness of teachers' perspectives of their best practices and their beliefs and reasons for these practices in the contexts of Internet Science Projects can improve the quality of science education programs. Methods. A series of pilot interviews was conducted during the 2000--2001 school year to develop the guiding questions for inquiring into teachers' perspectives of their best practices within the contexts of Internet Science Projects. This series of interviews resulted in the understanding of the need to select teachers with experiences with Internet Science Projects and to conduct in-depth phenomenological interviews for learning from their voices. Two teachers were purposefully selected as the participant-informants for this study, one an American elementary teacher from Walker County, Georgia, and one a Russian teacher from St. Petersburg, Russia. The study was conducted from October through December 2001. The data collected for this qualitative study consisted of a series of in-depth phenomenological interviews, classroom observations, and the collection and analysis of various artifacts including teacher journals, student products, and e-mail/bulletin board transcripts. The interview structure was based upon a modification of expanding Seidman's (1998) three interview series into multiple interviews concluded upon the determination of saturation of the topic. The series of interviews were composed of (1) life history focus; (2) the details of the experience of teaching within the contexts of Internet Science Projects; and (3) reflection on the meanings. The data analysis consisted of applying Strauss & Corbin's (1990) open

Bringing nursing science to the classroom: a collaborative project.

Science.gov (United States)

Reams, Susan; Bashford, Carol

2009-01-01

This project resulted as a collaborative effort on the part of a public school system and nursing faculty. The fifth grade student population utilized in this study focused on the skeletal, muscular, digestive, circulatory, respiratory, and nervous systems as part of their school system's existing science and health curriculum. The intent of the study was to evaluate the impact on student learning outcomes as a result of nursing-focused, science-based, hands-on experiential activities provided by nursing faculty in the public school setting. An assessment tool was created for pretesting and posttesting to evaluate learning outcomes resulting from the intervention. Over a two day period, six classes consisting of 25 to 30 students each were divided into three equal small groups and rotated among three interactive stations. Students explored the normal function of the digestive system, heart, lungs, and skin. Improvement in learning using the pretest and posttest assessment tools were documented.

The creation of science projects in the physics teachers preparation

Science.gov (United States)

Horváthová, Daniela; Rakovská, Mária; Zelenický, Ľubomír

2017-01-01

Terms - project, projecting and the method of projecting - are nowadays frequently used in different relations. Those terms, especially as methods (of a cognitive process), are also transferred to the educational process. Before a new educational method comes to practice, the teacher should be familiar with it and preferably when it is done so during his university studies. An optional subject called Physics in a system of science subjects has been included into physics curricula for students of the fourth year of their studies at the Faculty of Science of Constantine the Philosopher University in Nitra. Its task is to make students aware of ways how to coordinate knowledge and instructions presented in these subjects through analysis of curricula and textbooks. As a part of their seminars students are asked to create integrated tasks and experiments which can be assessed from the point of view of either physics or chemistry or biology and which can motivate pupils and form their complex view on various phenomena in the nature. Therefore the article discusses theoretical and also practical questions related to experience that originates from placing the mentioned method and the subject Physics in a system of science subjects into the preparation of a natural sciences teacher in our workplace.

Citizen Sky, An Update on the AAVSO's New Citizen Science Project

Science.gov (United States)

Turner, Rebecca; Price, A.; Henden, A.; Stencel, R.; Kloppenborg, B.

2011-01-01

Citizen Sky is a multi-year, NSF-funded, citizen science project focusing on the bright variable star, epsilon Aurigae. Citizen Sky goes beyond simple observing to include a major data analysis component. The goal is to introduce the participant to the full scientific process from background research to paper writing for a peer-reviewed journal. The first year of the project, 2009-10, was dedicated to developing project infrastructure, educating participants about epsilon Aurigae, and training these participants to observe the star and report their data. Looking forward, years two and three of the project will focus on assembling teams of participants to work on their own analysis and research. Results will be published in a special issue of the peer-reviewed Journal of the AAVSO. This project has been made possible by the National Science Foundation.

Tuning light emission of PbS nanocrystals from infrared to visible range by cation exchange

KAUST Repository

Binetti, Enrico

2015-10-27

Colloidal semiconductor nanocrystals, with intense and sharp-line emission between red and near-infrared spectral regions, are of great interest for optoelectronic and bio-imaging applications. The growth of an inorganic passivation layer on nanocrystal surfaces is a common strategy to improve their chemical and optical stability and their photoluminescence quantum yield. In particular, cation exchange is a suitable approach for shell growth at the expense of the nanocrystal core size. Here, the cation exchange process is used to promote the formation of a CdS passivation layer on the surface of very small PbS nanocrystals (2.3 nm in diameter), blue shifting their optical spectra and yielding luminescent and stable nanostructures emitting in the range of 700–850 nm. Structural, morphological and compositional investigation confirms the nanocrystal size contraction after the cation-exchange process, while the PbS rock-salt crystalline phase is retained. Absorption and photoluminescence spectroscopy demonstrate the growth of a passivation layer with a decrease of the PbS core size, as inferred by the blue-shift of the excitonic peaks. The surface passivation strongly increases the photoluminescence intensity and the excited state lifetime. In addition, the nanocrystals reveal increased stability against oxidation over time. Thanks to their absorption and emission spectral range and the slow recombination dynamics, such highly luminescent nano-objects can find interesting applications in sensitized photovoltaic cells and light-emitting devices.

Tuning light emission of PbS nanocrystals from infrared to visible range by cation exchange

KAUST Repository

Binetti, Enrico; Striccoli, Marinella; Sibillano, Teresa; Giannini, Cinzia; Brescia, Rosaria; Falqui, Andrea; Comparelli, Roberto; Corricelli, Michela; Tommasi, Raffaele; Agostiano, Angela; Curri, M Lucia

2015-01-01

Colloidal semiconductor nanocrystals, with intense and sharp-line emission between red and near-infrared spectral regions, are of great interest for optoelectronic and bio-imaging applications. The growth of an inorganic passivation layer on nanocrystal surfaces is a common strategy to improve their chemical and optical stability and their photoluminescence quantum yield. In particular, cation exchange is a suitable approach for shell growth at the expense of the nanocrystal core size. Here, the cation exchange process is used to promote the formation of a CdS passivation layer on the surface of very small PbS nanocrystals (2.3 nm in diameter), blue shifting their optical spectra and yielding luminescent and stable nanostructures emitting in the range of 700–850 nm. Structural, morphological and compositional investigation confirms the nanocrystal size contraction after the cation-exchange process, while the PbS rock-salt crystalline phase is retained. Absorption and photoluminescence spectroscopy demonstrate the growth of a passivation layer with a decrease of the PbS core size, as inferred by the blue-shift of the excitonic peaks. The surface passivation strongly increases the photoluminescence intensity and the excited state lifetime. In addition, the nanocrystals reveal increased stability against oxidation over time. Thanks to their absorption and emission spectral range and the slow recombination dynamics, such highly luminescent nano-objects can find interesting applications in sensitized photovoltaic cells and light-emitting devices.

Integrated learning of mathematics, science and technology concepts through LEGO/Logo projects

Science.gov (United States)

Wu, Lina

This dissertation examined integrated learning in the domains of mathematics, science and technology based on Piaget's constructivism, Papert's constructionism, and project-based approach to education. Ten fifth grade students were involved in a two-month long after school program where they designed and built their own computer-controlled LEGO/Logo projects that required the use of gears, ratios and motion concepts. The design of this study centered on three notions of integrated learning: (1) integration in terms of what educational materials/settings provide, (2) integration in terms of students' use of those materials, and (3) integration in the psychological sense. In terms of the first notion, the results generally showed that the LEGO/Logo environment supported the integrated learning of math, science and technology concepts. Regarding the second notion, the students all completed impressive projects of their own design. They successfully combined gears, motors, and LEGO parts together to create motion and writing control commands to manipulate the motion. But contrary to my initial expectations, their successful designs did not require numerical reasoning about ratios in designing effective gear systems. When they did reason about gear relationships, they worked with "qualitative" ratios, e.g., "a larger driver gear with a smaller driven gear increases the speed." In terms of the third notion of integrated learning, there was evidence in all four case study students of the psychological processes involved in linking mathematical, scientific, and/or technological concepts together to achieve new conceptual units. The students not only made connections between ideas and experiences, but also recognized decisive patterns and relationships in their project work. The students with stronger overall project performances showed more evidence of synthesis than the students with relatively weaker performances did. The findings support the conclusion that all three

Projects for the implementation of science technology society approach in basic concept of natural science course as application of optical and electrical instruments’ material

Science.gov (United States)

Satria, E.

2018-03-01

Preservice teachers in primary education should be well equipped to meet the challenges of teaching primary science effectively in 21century. The purpose of this research was to describe the projects for the implementation of Science-Technology-Society (STS) approach in Basic Concept of Natural Science course as application of optical and electrical instruments’ material by the preservice teachers in Elementary Schools Teacher Education Program. One of the reasons is the lack of preservice teachers’ ability in making projects for application of STS approach and optical and electrical instruments’ material in Basic Concept of Natural Science course. This research applied descriptive method. The instrument of the research was the researcher himself. The data were gathered through observation and documentation. Based on the results of the research, it was figured out that preservice teachers, in groups, were creatively and successful to make the projects of optical and electrical instruments assigned such as projector and doorbell. It was suggested that the construction of the instruments should be better (fixed and strong structure) and more attractive for both instruments, and used strong light source, high quality images, and it could use speaker box for projector, power battery, and heat sink for electrical instruments.

Linking project-based production and project management temporary systems in multiple contexts: An introduction to the special edition

Directory of Open Access Journals (Sweden)

Leon AG Oerlemans

2014-02-01

Full Text Available As organisations in more and more industries look for flexible ways of production in the wake of rapidly changing market environments, project-based organising is becoming an increasingly important mode of organisation (Eisenhardt & Tabrizi, 1995. Whereas project-based organisation was traditionally mainly the domain of industries such as film making (Sorenson & Waguespack, 2006, theatre (Goodman & Goodman, 1976, and construction (Gann & Salter, 2000, a project-based mode of operation has recently pervaded many other sectors in the economy, including software development, advertising, biotechnology, consulting, emergency response, fashion, television and complex products and systems (Grabher, 2004; Hobday, 2000. This increasing prevalence is reflected in an exponentially growing body of research (Bakker, 2010, which has made marked progress in areas such as project-based learning (Prencipe & Tell, 2001, project-based innovation (Eisenhardt & Tabrizi, 1995 and project-based careers (Jones, 1996. As a consequence, research on project organisation has moved from being a narrow specialty domain toward being a broad research paradigm, attending to a broad audience in organisation science and beyond (Sydow et al., 2004. In a fairly recent review paper, Bakker (2010 shows that in the period 1988–2008 scholarly attention, as indicated by publications in books and ISI-indexed journals, grew exponentially (see Figure 1. Comparing the number of publications in the period 1988-1998 with the period 1998–2008, he observed an increase of almost 340%.

History, Philosophy, and Science in a Social Perspective: A Pedagogical Project

Science.gov (United States)

Guerra, Andreia; Braga, Marco; Reis, Jose Claudio

2013-01-01

Various studies have promoted instruction in the history and philosophy of science (HPS) in science classes, but the best way of putting this perspective into practice remains undetermined. To contribute to this issue, we developed a pedagogical project in some high schools in Brazil that aimed to present science content using an…

Dissemination and Exploitation: Project Goals beyond Science

Science.gov (United States)

Hamann, Kristin; Reitz, Anja

2017-04-01

Dissemination and Exploitation are essential parts of public funded projects. In Horizon 2020 a plan for the exploitation and dissemination of results (PEDR) is a requirement. The plan should contain a clear vision on the objectives of the project in relation to actions for dissemination and potential exploitation of the project results. The actions follow the basic idea to spread the knowledge and results gathered within the project and face the challenge of how to bring the results into potentially relevant policy circle and how they impact the market. The plan follows the purpose to assess the impact of the project and to address various target groups who are interested in the project results. Simply put, dissemination concentrates on the transfer of knowledge and exploitation on the commercialization of the project. Beyond the question of the measurability of project`s impact, strategies within science marketing can serve purposes beyond internal and external communication. Accordingly, project managers are facing the challenge to implement a dissemination and exploitation strategy that ideally supports the identification of all partners with the project and matches the current discourse of the project`s content within the society, politics and economy. A consolidated plan might unite all projects partners under a central idea and supports the identification with the project beyond the individual research questions. Which applications, strategies and methods can be used to bring forward a PEDR that accompanies a project successfully and allows a comprehensive assessment of the project afterwards? Which hurdles might project managers experience in the dissemination process and which tasks should be fulfilled by the project manager?

Project HEAT: Temperature as an Organizing Theme for Inquiry-Based Learning in the Environmental Sciences

Science.gov (United States)

Albright, T. P.; Howard, K. L.; Ewing-Taylor, J.

2014-12-01

Professionals in science, technology, engineering, and mathematics (STEM) fields do not reflect the diversity of the US population. Among the most effective ways to attract and retain underrepresented students in STEM disciplines is to provide opportunities for participation in the scientific process and interaction with practicing scientists. Project HEAT (Hot Environments, Animals, & Temperature) is "boot-camp"-style workshop aimed at increasing interest in STEM topics among underrepresented, first-generation, college-bound middle school students. Linking to our NASA-funded research project "Desert Birds in a Warming World", we focused on how surprisingly variable temperature is in space and time, why temperature is important to plants, animals, and people, and how we measure temperature in the field and from space. Perhaps more importantly, this theme was a vehicle for students to experience science as a process: field observations, brainstorming questions and hypotheses, designing experiments to test them, and analyzing and reporting their data. The centerpiece was a set of experiments with small temperature sensors and radiation shields that teams of students designed, executed at a local park, analyzed, and reported. Two years of pre and post assessments revealed that Project HEAT participants increased understanding in content areas and showed slight increases in STEM interest. Year two results were markedly stronger than year one in both assessments as well as our perception. We attribute this to earlier summer timing of the workshop, a change from two half-day weeks to one full-day week, and a more age-homogeneous selection of students. In comments, participants expressed their special enjoyment of the hands-on nature of the program and the outdoor learning. Though providing such opportunities can be challenging, our experience here suggests that it can be worth while. Project HEAT also benefited our cadre of graduate student mentors by providing exposure

"Saturday Night Live" Goes to High School: Conducting and Advising a Political Science Fair Project

Science.gov (United States)

Allen, Meg; Brewer, Paul R.

2010-01-01

This article uses a case study to illustrate how science fair projects--which traditionally focus on "hard science" topics--can contribute to political science education. One of the authors, a high school student, conducted an experimental study of politics for her science fair project. The other author, a faculty member, was asked to advise the…

Improved performance of CdS/CdSe quantum dot-sensitized solar cells using Mn-doped PbS quantum dots as a catalyst in the counter electrode

International Nuclear Information System (INIS)

Kim, Byung-Man; Son, Min-Kyu; Kim, Soo-Kyoung; Hong, Na-Yeong; Park, Songyi; Jeong, Myeong-Soo; Seo, Hyunwoong; Prabakar, Kandasamy; Kim, Hee-Je

2014-01-01

Highlights: • PbS QDs synthesized using the SILAR method act not only as the electrochemical catalysts but as donors providing additional electrons under illumination. • The electrochemical and optical properties of the PbS QDs were enhanced considerably after Mn 2+ doping. • The electron supply from the counter electrode was significantly activated by Mn 2+ doping, improving the performance of QDSSC. - Abstract: This study reports the enhanced catalytic ability of Mn-doped PbS QDs synthesized using a successive ionic layer adsorption and reaction (SILAR) method for quantum dot-sensitized solar cells (QDSSCs). Electrochemical and optical analysis of each material showed that the catalytic ability of the PbS electrode was improved significantly by Mn 2+ doping. Two factors can explain this behavior. The first is that intentional impurities have an impact on the structure of the host material, such as increases in surface roughness. The other is that dopants create new energy states that delay the exciton recombination time and allow charge separation to be activated. As a result, the photoelectron supply from the counter electrode is accelerated, resulting in vigorous redox reactions at the polysulfide electrolyte. The performance of the CdS/CdSe QDSSC using a Mn-doped PbS counter electrode was compared with those using the Pt and PbS counter electrodes. Finally, a power conversion efficiency of 3.61% was achieved with the Mn-doped PbS counter electrode (V OC = 0.61 V, J SC = 11.67 mA cm −2 , FF = 0.51) under one sun illumination (100 mW cm −2 ), which is ∼40% higher than that of CdS/CdSe QDSSCs with the bare PbS counter electrode

Student projects in medicine: a lesson in science and ethics.

Science.gov (United States)

Edwards, Sarah J L

2009-11-01

Regulation of biomedical research is the subject of considerable debate in the bioethics and health policy worlds. The ethics and governance of medical student projects is becoming an increasingly important topic in its own right, especially in the U.K., where there are periodic calls to change it. My main claim is that there seems to be no good reason for treating student projects differently from projects led by qualified and more experienced scientists and hence no good grounds for changing the current system of ethics review. I first suggest that the educational objectives cannot be met without laying down standards of good science, whatever they may be. Weak science is unnecessary for educational purposes, and it is, in any case, unlikely to produce good researchers in the future. Furthermore, it is curious to want to change the system of ethics review specifically for students when it is the science that is at stake, and when the science now falls largely outside the ethics remit. I further show that ethics review is nevertheless important since students carry a new potential conflict of interests that warrants independent oversight which supervisory support does not offer. This potential conflict may become more morally troublesome the greater the risks to the subjects of the research, and students may impose greater risks on their subjects (relative to professional researchers) by virtue of being inexperienced, whatever the nature of the project. Pragmatic concerns may finally be allayed by organizing the current system more efficiently at critical times of the university calendar.

OPEN INNOVATION PROJECT: THE SYSTEM OF ONLINE INDICATORS IN SCIENCE, TECHNOLOGY AND INNOVATION OF AMAZONAS (SiON

Directory of Open Access Journals (Sweden)

Moises Andrade Coelho

2016-05-01

Full Text Available This study aims to evaluate the implementation of an open innovation project in a public institution in the state of Amazonas. The theoretical and empirical background deals with science, technology and innovation indicators and open innovation. The study is characterized as a qualitative and descriptive research, with the case study as a methodological procedure. The delimitation of the universe was composed by a public institution in the area of science, technology and innovation (ST&I. In the case study, it was used an approach as tool to assess the implementation of open innovation projects. The results are shown several stages of open innovation project analyzed.  The study demonstrates the implications of open innovation project adoption to the strengthening of external networks and the maturing of the internal environment. The relevance of the study is based on the evaluation of an open innovation project in a public institution in order to foster the transition from traditional innovation processes to open innovation processes.

Using p-type PbS Quantum Dots to Quench Photocurrent of Fullerene-Au NP@MoS2 Composite Structure for Ultrasensitive Photoelectrochemical Detection of ATP.

Science.gov (United States)

Li, Meng-Jie; Zheng, Ying-Ning; Liang, Wen-Bin; Yuan, Ruo; Chai, Ya-Qin

2017-12-06

Ultrasensitive and rapid quantification of the universal energy currency adenosine triphosphate (ATP) is an extremely critical mission in clinical applications. In this work, a "signal-off" photoelectrochemical (PEC) biosensor was designed for ultrasensitive ATP detection based on a fullerene (C 60 )-decorated Au nanoparticle@MoS 2 (C 60 -Au NP@MoS 2 ) composite material as a signal indicator and a p-type PbS quantum dot (QD) as an efficient signal quencher. Modification of wide band gap C 60 with narrow band gap MoS 2 to form an ideal PEC signal indicator was proposed, which could significantly improve photocurrent conversion efficiency, leading to a desirable PEC signal. In the presence of p-type PbS QDs, the PEC signal of n-type C 60 -Au NP@MoS 2 was effectively quenched because p-type PbS QDs could compete with C 60 -Au NP@MoS 2 to consume light energy and electron donor. Besides, the conversion of a limited amount of target ATP into an amplified output PbS QD-labeled short DNA sequence (output S 1 ) was achieved via target-mediated aptazyme cycling amplification strategy, facilitating ultrasensitive ATP detection. The proposed signal-off PEC strategy exhibited a wide linear range from 1.00 × 10 -2 pM to 100 nM with a low detection limit of 3.30 fM. Importantly, this proposed strategy provides a promising platform to detect ATP at ultralow levels and has potential applications, including diagnosis of ATP-related diseases, monitoring of diseases progression and evaluation of prognosis.

Support of an Active Science Project by a Large Information System: Lessons for the EOS Era

Science.gov (United States)

Angelici, Gary L.; Skiles, J. W.; Popovici, Lidia Z.

1993-01-01

The ability of large information systems to support the changing data requirements of active science projects is being tested in a NASA collaborative study. This paper briefly profiles both the active science project and the large information system involved in this effort and offers some observations about the effectiveness of the project support. This is followed by lessons that are important for those participating in large information systems that need to support active science projects or that make available the valuable data produced by these projects. We learned in this work that it is difficult for a large information system focused on long term data management to satisfy the requirements of an on-going science project. For example, in order to provide the best service, it is important for all information system staff to keep focused on the needs and constraints of the scientists in the development of appropriate services. If the lessons learned in this and other science support experiences are not applied by those involved with large information systems of the EOS (Earth Observing System) era, then the final data products produced by future science projects may not be robust or of high quality, thereby making the conduct of the project science less efficacious and reducing the value of these unique suites of data for future research.

Combination of short-length TiO_2 nanorod arrays and compact PbS quantum-dot thin films for efficient solid-state quantum-dot-sensitized solar cells

International Nuclear Information System (INIS)

Zhang, Zhengguo; Shi, Chengwu; Chen, Junjun; Xiao, Guannan; Li, Long

2017-01-01

Graphical abstract: The TiO_2 nanorod array with the length of 600 nm, the diameter of 20 nm, the areal density of 500 μm"−"2 was successfully prepared. The compact PbS quantum-dot thin film was firstly obtained on the TiO_2 nanorod array by spin-coating-assisted successive ionic layer absorption and reaction with using 1,2-ethanedithiol. The photoelectric conversion efficiency (PCE) of the compact PbS quantum-dot thin film sensitized solar cells achieved 4.10% using spiro-OMeTAD as a hole transporting layer, while the PCE of the PbS quantum-dot sensitized solar cells was only 0.54%. - Highlights: • Preparation of TiO_2 nanorod arrays with the length of 600 nm, diameter of 20 nm. • The compact PbS QD thin film and short-length TiO_2 nanorod array were combined. • EDT addition improved PbS nanoparticle coverage and photovoltaic performance. • The compact PbS QD thin film sensitized solar cell achieved the PCE of 4.10%. - Abstract: Considering the balance of the hole diffusion length and the loading quantity of quantum-dots, the rutile TiO_2 nanorod array with the length of 600 nm, the diameter of 20 nm, and the areal density of 500 μm"−"2 is successfully prepared by the hydrothermal method using the aqueous grown solution of 38 mM titanium isopropoxide and 6 M hydrochloric acid at 170 °C for 105 min. The compact PbS quantum-dot thin film on the TiO_2 nanorod array is firstly obtained by the spin-coating-assisted successive ionic layer absorption and reaction with using 1,2-ethanedithiol (EDT). The result reveals that the strong interaction between lead and EDT is very important to control the crystallite size of PbS quantum-dots and obtain the compact PbS quantum-dot thin film on the TiO_2 nanorod array. The all solid-state sensitized solar cell with the combination of the short-length, high-density TiO_2 nanorod array and the compact PbS quantum-dot thin film achieves the photoelectric conversion efficiency of 4.10%, along with an open

A Cross-Cultural Study of the Effect of a Graph-Oriented Computer-Assisted Project-Based Learning Environment on Middle School Students' Science Knowledge and Argumentation Skills

Science.gov (United States)

Hsu, P.-S.; Van Dyke, M.; Chen, Y.; Smith, T. J.

2016-01-01

The purpose of this mixed-methods study was to explore how seventh graders in a suburban school in the United States and sixth graders in an urban school in Taiwan developed argumentation skills and science knowledge in a project-based learning environment that incorporated a graph-oriented, computer-assisted application (GOCAA). A total of 42…

Chemical Database Projects Delivered by RSC eScience

OpenAIRE

Williams, Antony

2013-01-01

This presentation is an overview of some of the projects we are involved with at RSC eScience. The presentation was given at the FDA Meeting regarding the “Development of a Freely Distributable Data System for the Registration of Substances"  

Project Citizen: Promoting Action-Oriented Citizen Science in the Classroom

Science.gov (United States)

Green, Carie; Medina-Jerez, William

2012-01-01

In recent years, citizen science projects have emerged as a means to involve students in scientific inquiry, particularly in the fields of ecology and environmental science. A citizen scientist is "a volunteer who collects and/or processes data as part of a scientific inquiry" (Silverton 2009, p. 467). Participation in citizen science…

Soil Science self-learning based on the design and conduction of experiments

Science.gov (United States)

Jordán, A.; Bárcenas-Moreno, G.; Zavala, L. M.

2012-04-01

This paper presents an experience for introducing the methodology of project-based learning (PBL) in the area of Soil Science in the University of Sevilla (Spain). Currently, teachers try to enhance practical experience of university students in a complementary manner to theoretical knowledge. However, many times this is a difficult process. Practice is an important part of personal work in the vast majority of subjects that degree students receive, since the implementation of the EHEA. In most cases, these experiences are presented as partial small experiments or projects, assigned to the area-specific knowledge agenda. Certain sciences, such as Soil Science, however, require synthesis and integration capabilities of previous knowledge. It is therefore necessary to develop practical programs that address the student not only to the performance of laboratory determinations, but to the formulation of hypotheses, experimental design and problem solving, whether in groups or individually, situated in a wide context and allowing students to make connections with other areas of knowledge. This project involves the development of teamwork experiments, for the study real cases and problems and making decisions in the field of Soil Science. The results of the experimental work were publicly exposed as posters and oral presentations and were discussed during a mini-congress open to students and a general audience. The open and dynamic nature of the project substantially improves student motivation, which adds value to our project. Due to the multidisciplinary character of Soil Science it is relatively easy to propose projects of some complexity, and therefore, provides good conditions for introducing the PBL methodology. The teacher's role is also important and is not limited to observe or qualify the students, but it is a catalyst for learning. It is important that teacher give the leadership of the process and make the students themselves feel the protagonists of the

Teacher Perceptions of Project Based Learning in the Secondary Classroom

Science.gov (United States)

MacMath, Sheryl; Sivia, Awneet; Britton, Vandy

2017-01-01

This study examines teacher perceptions of their experiences with Project Based Learning (PBL) at a secondary school in Western Canada. This PBL initiative included English language arts, mathematics, science, and digital literacy courses and all the grade nines at this large secondary school. This article reports on two teacher focus group…

Space Sciences Education and Outreach Project of Moscow State University

Science.gov (United States)

Krasotkin, S.

2006-11-01

sergekras@mail.ru The space sciences education and outreach project was initiated at Moscow State University in order to incorporate modern space research into the curriculum popularize the basics of space physics, and enhance public interest in space exploration. On 20 January 2005 the first Russian University Satellite “Universitetskiy-Tatyana” was launched into circular polar orbit (inclination 83 deg., altitude 940-980 km). The onboard scientific complex “Tatyana“, as well as the mission control and information receiving centre, was designed and developed at Moscow State University. The scientific programme of the mission includes measurements of space radiation in different energy channels and Earth UV luminosity and lightning. The current education programme consists of basic multimedia lectures “Life of the Earth in the Solar Atmosphere” and computerized practice exercises “Space Practice” (based on the quasi-real-time data obtained from “Universitetskiy-Tatyana” satellite and other Internet resources). A multimedia lectures LIFE OF EARTH IN THE SOLAR ATMOSPHERE containing the basic information and demonstrations of heliophysics (including Sun structure and solar activity, heliosphere and geophysics, solar-terrestrial connections and solar influence on the Earth’s life) was created for upper high-school and junior university students. For the upper-university students there a dozen special computerized hands-on exercises were created based on the experimental quasi-real-time data obtained from our satellites. Students specializing in space physics from a few Russian universities are involved in scientific work. Educational materials focus on upper high school, middle university and special level for space physics students. Moscow State University is now extending its space science education programme by creating multimedia lectures on remote sensing, space factors and materials study, satellite design and development, etc. The space

Optimization of synthesis conditions of PbS thin films grown by chemical bath deposition using response surface methodology

Energy Technology Data Exchange (ETDEWEB)

Yücel, Ersin, E-mail: dr.ersinyucel@gmail.com [Department of Physics, Faculty of Arts and Sciences, Mustafa Kemal University, 31034 Hatay (Turkey); Yücel, Yasin; Beleli, Buse [Department of Chemistry, Faculty of Arts and Sciences, Mustafa Kemal University, 31034 Hatay (Turkey)

2015-09-05

Highlights: • For the first time, RSM and CCD used for optimization of PbS thin film. • Tri-sodium citrate, deposition time and temperature were independent variables. • PbS thin film band gap value was 2.20 eV under the optimum conditions. • Quality of the film was improved after chemometrics optimization. - Abstract: In this study, PbS thin films were synthesized by chemical bath deposition (CBD) under different deposition parameters. Response surface methodology (RSM) was used to optimize synthesis parameters including amount of tri-sodium citrate (0.2–0.8 mL), deposition time (14–34 h) and deposition temperature (26.6–43.4 °C) for deposition of the films. 5-level-3-factor central composite design (CCD) was employed to evaluate effects of the deposition parameters on the response (optical band gap of the films). The significant level of both the main effects and the interaction are investigated by analysis of variance (ANOVA). The film structures were characterized by X-ray diffractometer (XRD). Morphological properties of the films were studied with a scanning electron microscopy (SEM). The optical properties of the films were investigated using a UV–visible spectrophotometer. The optimum amount of tri-sodium citrate, deposition time and deposition temperature were found to be 0.7 mL, 18.07 h and 30 °C respectively. Under these conditions, the experimental band gap of PbS was 2.20 eV, which is quite good correlation with value (1.98 eV) predicted by the model.

Optimization of synthesis conditions of PbS thin films grown by chemical bath deposition using response surface methodology

International Nuclear Information System (INIS)

Yücel, Ersin; Yücel, Yasin; Beleli, Buse

2015-01-01

Highlights: • For the first time, RSM and CCD used for optimization of PbS thin film. • Tri-sodium citrate, deposition time and temperature were independent variables. • PbS thin film band gap value was 2.20 eV under the optimum conditions. • Quality of the film was improved after chemometrics optimization. - Abstract: In this study, PbS thin films were synthesized by chemical bath deposition (CBD) under different deposition parameters. Response surface methodology (RSM) was used to optimize synthesis parameters including amount of tri-sodium citrate (0.2–0.8 mL), deposition time (14–34 h) and deposition temperature (26.6–43.4 °C) for deposition of the films. 5-level-3-factor central composite design (CCD) was employed to evaluate effects of the deposition parameters on the response (optical band gap of the films). The significant level of both the main effects and the interaction are investigated by analysis of variance (ANOVA). The film structures were characterized by X-ray diffractometer (XRD). Morphological properties of the films were studied with a scanning electron microscopy (SEM). The optical properties of the films were investigated using a UV–visible spectrophotometer. The optimum amount of tri-sodium citrate, deposition time and deposition temperature were found to be 0.7 mL, 18.07 h and 30 °C respectively. Under these conditions, the experimental band gap of PbS was 2.20 eV, which is quite good correlation with value (1.98 eV) predicted by the model

Project-based production and project management: Findings and trends in research on temporary systems in multiple contexts

Directory of Open Access Journals (Sweden)

Tinus Pretorius

2014-02-01

Full Text Available Globalisation is challenging almost every aspect of the political, economic, social and technological environment. Organisations, whether public or private, have to adapt their strategies and operations to stay competitive and efficient. Historically, organisations adopted project-based operations as a mode to stay competitive, although the applications tended to be the oneoff type of operations such as construction and system development projects (Edum-Fotwe & McCaffer, 2000. As the world changed from an industrially driven to a more knowledge driven economy and the pace of continuous change became more intense, organisations adopted a project-based mode of operations on a broader scale. The knowledge economy lead to the creation of many service orientated industries. Organisations started facing portfolios of projects where the nature of these projects differed in technological complexity, urgency, customer value and social impact (Gutjahr & Froeschl, 2013. Based on their experience with more technically orientated projects, organisations focused their attention more intensely on new project management methods, tools and processes and not necessarily on the human and organisational interfaces. This paradigm changed however, especially since the 1980s and more and more organisations adopted temporary organisational forms (Bakker, 2010 in order to improve their competitiveness. The contributions in this special edition of the South African Journal of Economic and Management Sciences have a common focus on the importance of the human and organisational interface of project-based operations on project success. The purpose of this concluding article is to analyse the findings and recommendations in these papers and to detect trends and future research opportunities in the field of project-based operations.

SCIENCE TEACHERS’ INDIVIDUAL AND SOCIAL LEARNING RELATED TO IBSE IN A LARGE-SCALE, LONG- TERM, COLLABORATIVE TPD PROJECT

DEFF Research Database (Denmark)

Nielsen, Birgitte Lund; Sillasen, Martin Krabbe

2014-01-01

It is acknowledged internationally that teachers’ Professional Development (TPD) is crucial for reforming science teaching. The Danish QUEST project is designed using widely agreed criteria for effective TPD: content focus, active learning, coherence, duration, collaborative activities and collec......It is acknowledged internationally that teachers’ Professional Development (TPD) is crucial for reforming science teaching. The Danish QUEST project is designed using widely agreed criteria for effective TPD: content focus, active learning, coherence, duration, collaborative activities...... and collective participation, and is organised on principles of situated learning in Professional Learning Communities (PLCs). QUEST-activities follow a rhythm of full day seminars followed by a period of collaborative inquiries locally. A major theme in the first year has been Inquiry Based Science Education......-on experiences and fewer including students’ minds-on. Teachers’ reflections indicate that many are positive towards QUEST seminars based on trying out activities directly applicable in the classroom. Case studies indicate a potentially more sustainable development, where the teachers collaboratively re...

Technology Base Research Project for electrochemical energy storage

Science.gov (United States)

Kinoshita, K.

1985-06-01

The DOE Electrochemical Energy Storage Program is divided into two projects: (1) the exploratory technology development and testing (ETD) project and (2) the technology base research (TBR) project. The role of the TBR Project is to perform supporting research for the advanced battery systems under development by the ETD Project, and to evaluate new systems with potentially superior performance, durability and/or cost characteristics. The specific goal of the TBR Project is to identify the most promising electrochemical technologies and transfer them to industry and/or the ETD Project for further development and scale-up. This report summarizes the research, financial, and management activities relevant to the TBR Project in CY 1984. General problem areas addressed by the project include identification of new electrochemical couples for advanced batteries, determination of technical feasibility of the new couples, improvements in battery components and materials, establishment of engineering principles applicable to electrochemical energy storage and conversion, and the assessment of fuel-cell technology for transportation applications. Major emphasis is given to applied research which will lead to superior performance and lower life-cycle costs. The TBR Project is divided into three major project elements: exploratory research, applied science research, and air systems research.

Engaging High School Science Teachers in Field-Based Seismology Research: Opportunities and Challenges

Science.gov (United States)

Long, M. D.

2015-12-01

Research experiences for secondary school science teachers have been shown to improve their students' test scores, and there is a substantial body of literature about the effectiveness of RET (Research Experience for Teachers) or SWEPT (Scientific Work Experience Programs for Teachers) programs. RET programs enjoy substantial support, and several opportunities for science teachers to engage in research currently exist. However, there are barriers to teacher participation in research projects; for example, laboratory-based projects can be time consuming and require extensive training before a participant can meaningfully engage in scientific inquiry. Field-based projects can be an effective avenue for involving teachers in research; at its best, earth science field work is a fun, highly immersive experience that meaningfully contributes to scientific research projects, and can provide a payoff that is out of proportion to a relatively small time commitment. In particular, broadband seismology deployments provide an excellent opportunity to provide teachers with field-based research experience. Such deployments are labor-intensive and require large teams, with field tasks that vary from digging holes and pouring concrete to constructing and configuring electronics systems and leveling and orienting seismometers. A recently established pilot program, known as FEST (Field Experiences for Science Teachers) is experimenting with providing one week of summer field experience for high school earth science teachers in Connecticut. Here I report on results and challenges from the first year of the program, which is funded by the NSF-CAREER program and is being run in conjunction with a temporary deployment of 15 seismometers in Connecticut, known as SEISConn (Seismic Experiment for Imaging Structure beneath Connecticut). A small group of teachers participated in a week of field work in August 2015 to deploy seismometers in northern CT; this experience followed a visit of the

The I-Cleen Project (inquiring on Climate & Energy). Enhancing AN Enquiry-Based Approach to Earth System Sciences in Italian Classrooms

Science.gov (United States)

Cattadori, M.

2010-12-01

In the last years, the world of Italian school underwent some slow but deep transformation processes. One of the negative consequences - documented by specific studies - was the further weakening of the use of inquiring educational practices (or kinds of lessons) by science teachers. This occurred in a scholastic framework already traditionally little inclined to those. The I-CLEEN project (Inquiring on CLimate & Energy, www.icleen.museum ) was born in 2008 with the intent to react to (and contrast) this process (trend) by initiative of a staff of science teachers from different regions, all with many years’ experience, coordinated and supported by the local museum, the Natural Science Museum of Trento - Trento, Italy. I-CLEEN is a free instrument of cooperation for Italian teachers, aimed to support and enhance the practice of the inquiring education in explaining themes in range of Climate and Energy and generally about Earth System Sciences. This project is a consequence of what has been experienced and done in Italy by its creators within the Educational and Outreach program of ANDRILL (ANtarctic geological DRILLing). The core of the project is a database of resources potentially useful to a teacher preparing an inquiring lesson. These are selected by a staff following a specific selection policy. There are also lessons ready to be used in the classrooms, prepared according to a specific editorial standard. These are composed by a paper for the teacher and a paper for the student. The database is technically an information gateway and it is constantly enriched thanks to a job of critical research in the teachers’ practices or the worthiest international educational web projects. These are published in Italian or in bilingual format (Italian-English), always through explicit authorization by the authors and under a Creative Commons license when possible. This contribution illustrates details about this service which is on-line since December 2009 and is

Tn5-induced pBS286 plasmid mutations blocking early stages of napthalene oxidation

International Nuclear Information System (INIS)

Kosheleva, I.A.; Tsoi, T.V.; Ivashina, T.V.; Selifonov, S.A.; Starovoitov, I.I.; Boronin, A.M.

1988-01-01

The authors present data on the further analysis of the structural and functional organization of the nah region of plasmid pBS286 controlling the constitutive oxidation of naphthalene by Pseudomonas putida cells. They have studied Tn5-induced mutations blocking early stages of naphthalene oxidation. They present and discuss data providing evidence that, in contrast to plasmid NAH7, the mechanism of regulation of the nahl operon of plasmid NPL-1, the parent plasmid of plasmid pBS286, with inducible synthesis of naphthalene dioxygenase can include elements of a negative control with participation of the regulatory locus R, located proximal to the structural nah genes and closely linked to or overlapped by the inverted control DNA segment (4.2 kb). They also present data on the possibility of regulation of the activity of the catechol-splitting meta-pathway genes with the participation of products of early stages of naphthalene oxidation

The Use of Online Citizen-Science Projects to Provide Experiential Learning Opportunities for Nonmajor Science Students?

OpenAIRE

Kridelbaugh, Donna M.

2016-01-01

Citizen science is becoming even more accessible to the general public through technological advances in the development of mobile applications, facilitating information dissemination and data collection. With the advent of “big data,” many citizen-science projects designed to help researchers sift through piles of research data now exist entirely online, either in the form of playing a game or via other digital avenues. Recent trends in citizen science have also focused on “crowdsourcing” so...

Why 'Science + Solutions' Is An Effective & Essential Climate Communications Strategy (Invited)

Science.gov (United States)

Haines-Stiles, G.; Alley, R. B.; Akuginow, E.

2013-12-01

Success in the Second World War was enabled in large part through advances in science and technology such as radar and the Manhattan Project, and the subsequent growth of the US economy endowed scientists with unrivaled influence in society and policy-making. But climate science has not been immune to criticism, and attacks on what 97% of expert climate scientists regard as well-established have continued. However, as shown in Leiserowitz et al's series of SIX AMERICAS studies, the vast majority of citizens are neither firmly committed against accepting the reality of human-caused climate change, nor 100% certain of the cause. The question, then, is how to reach 'the movable middle.' Richard Alley's 'Earth: The Operators' Manual'-a 3-part series aired nationally on PBS, and supported by the National Science Foundation-was an attempt to improve the understanding of consensus climate science, and showcase examples of clean energy innovations in the United States and worldwide. A fundamental design principle for the series, derived from close reading of social science studies, was to include solutions along with solid science. In addition, the producers enlisted a diverse cast of on-camera personalities alongside Alley: Texas ranchers, Republican senators and Kansan bankers, CEOs and academics, a Navy rear admiral in dress whites, and 'energy captains' in inner city Baltimore. An NSF-mandated Summative Evaluation documented the success of these approaches, and the first two programs reached some 3.6 million viewers on PBS. However, the rapidly-evolving media landscape has meant that national primetime exposure is only part of how climate information is 'sent' and 'received' today. ETOM structured its Facebook page to embody the same solutions-oriented philosophy, and has secured an 'Engagement Index' higher than Buzzfeed, and more than most other environment- and climate-oriented pages. ETOM programs can be downloaded in HD for watch parties, and many schools

Reform-based science teaching: A mixed-methods approach to explaining variation in secondary science teacher practice

Science.gov (United States)

Jetty, Lauren E.

The purpose of this two-phase, sequential explanatory mixed-methods study was to understand and explain the variation seen in secondary science teachers' enactment of reform-based instructional practices. Utilizing teacher socialization theory, this mixed-methods analysis was conducted to determine the relative influence of secondary science teachers' characteristics, backgrounds and experiences across their teacher development to explain the range of teaching practices exhibited by graduates from three reform-oriented teacher preparation programs. Data for this study were obtained from the Investigating the Meaningfulness of Preservice Programs Across the Continuum of Teaching (IMPPACT) Project, a multi-university, longitudinal study funded by NSF. In the first quantitative phase of the study, data for the sample (N=120) were collected from three surveys from the IMPPACT Project database. Hierarchical multiple regression analysis was used to examine the separate as well as the combined influence of factors such as teachers' personal and professional background characteristics, beliefs about reform-based science teaching, feelings of preparedness to teach science, school context, school culture and climate of professional learning, and influences of the policy environment on the teachers' use of reform-based instructional practices. Findings indicate three blocks of variables, professional background, beliefs/efficacy, and local school context added significant contribution to explaining nearly 38% of the variation in secondary science teachers' use of reform-based instructional practices. The five variables that significantly contributed to explaining variation in teachers' use of reform-based instructional practices in the full model were, university of teacher preparation, sense of preparation for teaching science, the quality of professional development, science content focused professional, and the perceived level of professional autonomy. Using the results

Enhanced Mobility-Lifetime Products in PbS Colloidal Quantum Dot Photovoltaics

KAUST Repository

Jeong, Kwang S.

2012-01-24

Figure Persented: Colloidal quantum dot (CQD) photovoltaics offer a promising approach to harvest the near-IR region of the solar spectrum, where half of the sun\\'s power reaching the earth resides. High external quantum efficiencies have been obtained in the visible region in lead chalcogenide CQD photovoltaics. However, the corresponding efficiencies for band gap radiation in the near-infrared lag behind because the thickness of CQD photovoltaic layers from which charge carriers can be extracted is limited by short carrier diffusion lengths. Here, we investigate, using a combination of electrical and optical characterization techniques, ligand passivation strategies aimed at tuning the density and energetic distribution of charge trap states at PbS nanocrystal surfaces. Electrical and optical measurements reveal a more than 7-fold enhancement of the mobility-lifetime product of PbS CQD films treated with 3-mercaptopropionic acid (MPA) in comparison to traditional organic passivation strategies that have been examined in the literature. We show by direct head-to-head comparison that the greater mobility-lifetime products of MPA-treated devices enable markedly greater short-circuit current and higher power conversion efficiency under AM1.5 illumination. Our findings highlight the importance of selecting ligand treatment strategies capable of passivating a diversity of surface states to enable shallower and lower density trap distributions for better transport and more efficient CQD solar cells. © 2011 American Chemical Society.

[Analysis of projects of infectious disease epidemiology sponsored by National Natural Science Foundation of China].

Science.gov (United States)

Jian-Ming, Wang; Yan-Kai, Xia; Hui-Juan, Zhu; Feng, Chen; Hong-Bing, Shen

2016-05-10

To analyze the projects on the infectious disease epidemiology sponsored by the National Natural Science Foundation of China (NSFC), explore the hotspot and development trend, and offer a reference for researchers in this field. Based on the NSFC database, the projects on the infectious disease epidemiology (H2609) sponsored from 1987 to 2014 were analyzed. The changes of fund numbers, amounts and research fields were described. During the study period, NSFC sponsored 373 projects, including 228 general projects (61.1%), 78 youth projects (20.9%) and 67 other projects (18.0%). The average amount of the grant was 358.2 thousand Yuan (20 thousand-8 million). The main sponsored research fields were mechanisms of pathogen and immunity (36.2%) and population-based epidemiological studies (33.0%). The top three diseases were hepatitis, HIV/AIDS and tuberculosis. The amount of funding on researches of infectious disease epidemiology has increased continuously, which has played an important role in training scientific talents in the field of prevention and control of infectious diseases.

High-performance PbS quantum dot vertical field-effect phototransistor using graphene as a transparent electrode

Science.gov (United States)

Che, Yongli; Zhang, Yating; Cao, Xiaolong; Song, Xiaoxian; Zhang, Haiting; Cao, Mingxuan; Dai, Haitao; Yang, Junbo; Zhang, Guizhong; Yao, Jianquan

2016-12-01

Solution processed photoactive PbS quantum dots (QDs) were used as channel in high-performance near-infrared vertical field-effect phototransistor (VFEpT) where monolayer graphene embedded as transparent electrode. In this vertical architecture, the PbS QD channel was sandwiched and naturally protected between the drain and source electrodes, which made the device ultrashort channel length (110 nm) simply the thickness of the channel layer. The VFEpT exhibited ambipolar operation with high mobilities of μe = 3.5 cm2/V s in n-channel operation and μh = 3.3 cm2/V s in p-channel operation at low operation voltages. By using the photoactive PbS QDs as channel material, the VFEpT exhibited good photoresponse properties with a responsivity of 4.2 × 102 A/W, an external quantum efficiency of 6.4 × 104% and a photodetectivity of 2.1 × 109 Jones at the light irradiance of 36 mW/cm2. Additionally, the VFEpT showed excellent on/off switching with good stability and reproducibility and fast response speed with a short rise time of 12 ms in n-channel operation and 10.6 ms in p-channel operation. These high mobilities, good photoresponse properties and simplistic fabrication of our VFEpTs provided a facile route to the high-performance inorganic photodetectors.

Combination of short-length TiO{sub 2} nanorod arrays and compact PbS quantum-dot thin films for efficient solid-state quantum-dot-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Zhang, Zhengguo [School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009 (China); School of Chemistry and Chemical Engineering, Beifang University of Nationalities, Yinchuan 750021 (China); Shi, Chengwu, E-mail: shicw506@foxmail.com [School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009 (China); Chen, Junjun; Xiao, Guannan; Li, Long [School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009 (China)

2017-07-15

Graphical abstract: The TiO{sub 2} nanorod array with the length of 600 nm, the diameter of 20 nm, the areal density of 500 μm{sup −2} was successfully prepared. The compact PbS quantum-dot thin film was firstly obtained on the TiO{sub 2} nanorod array by spin-coating-assisted successive ionic layer absorption and reaction with using 1,2-ethanedithiol. The photoelectric conversion efficiency (PCE) of the compact PbS quantum-dot thin film sensitized solar cells achieved 4.10% using spiro-OMeTAD as a hole transporting layer, while the PCE of the PbS quantum-dot sensitized solar cells was only 0.54%. - Highlights: • Preparation of TiO{sub 2} nanorod arrays with the length of 600 nm, diameter of 20 nm. • The compact PbS QD thin film and short-length TiO{sub 2} nanorod array were combined. • EDT addition improved PbS nanoparticle coverage and photovoltaic performance. • The compact PbS QD thin film sensitized solar cell achieved the PCE of 4.10%. - Abstract: Considering the balance of the hole diffusion length and the loading quantity of quantum-dots, the rutile TiO{sub 2} nanorod array with the length of 600 nm, the diameter of 20 nm, and the areal density of 500 μm{sup −2} is successfully prepared by the hydrothermal method using the aqueous grown solution of 38 mM titanium isopropoxide and 6 M hydrochloric acid at 170 °C for 105 min. The compact PbS quantum-dot thin film on the TiO{sub 2} nanorod array is firstly obtained by the spin-coating-assisted successive ionic layer absorption and reaction with using 1,2-ethanedithiol (EDT). The result reveals that the strong interaction between lead and EDT is very important to control the crystallite size of PbS quantum-dots and obtain the compact PbS quantum-dot thin film on the TiO{sub 2} nanorod array. The all solid-state sensitized solar cell with the combination of the short-length, high-density TiO{sub 2} nanorod array and the compact PbS quantum-dot thin film achieves the photoelectric conversion

A school and inquiry based project with Nordic student teachers

DEFF Research Database (Denmark)

Stougaard, Birgitte

Álka is a framework involving teacher education institutions in the Nordic counties. This study describes the design of a module aiming at the establishment of a stronger nexus between research (theory) and teaching of science (practice) and to explore an issue relevant for the student teachers...... future professional life. The theme that was used for the research based project was: Nordic Children’s ideas about living things in the sea. Oral presentation at The 10th Nordic Research Symposium on Science Education (NFSUN), Linköbing, Sweden, June 2011....

Managing open innovation projects with science-based and market-based partners

NARCIS (Netherlands)

Du, J.; Leten, B.; Vanhaverbeke, W.

2014-01-01

This paper examines the relationship between (outside-in) open innovation and the financial performance of R&D projects, drawing on a unique dataset that contains information on the open innovation practices, management and performance of 489 R&D projects of a large European multinational firm. We

77 FR 35393 - Federal Management Regulation; FMR Bulletin PBS-2012-03; Redesignations of Federal Buildings

Science.gov (United States)

2012-06-13

... Management Regulation; FMR Bulletin PBS-2012-03; Redesignations of Federal Buildings AGENCY: Public Buildings... bulletin announces the designation and redesignation of three Federal buildings. Expiration Date: This bulletin announcement expires October 31, 2012. The building designation and redesignations remains in...

Science Teacher Efficacy and Extrinsic Factors Toward Professional Development Using Video Games in a Design-Based Research Model: The Next Generation of STEM Learning

Science.gov (United States)

Annetta, Leonard A.; Frazier, Wendy M.; Folta, Elizabeth; Holmes, Shawn; Lamb, Richard; Cheng, Meng-Tzu

2013-02-01

Designed-based research principles guided the study of 51 secondary-science teachers in the second year of a 3-year professional development project. The project entailed the creation of student-centered, inquiry-based, science, video games. A professional development model appropriate for infusing innovative technologies into standards-based curricula was employed to determine how science teacher's attitudes and efficacy where impacted while designing science-based video games. The study's mixed-method design ascertained teacher efficacy on five factors (General computer use, Science Learning, Inquiry Teaching and Learning, Synchronous chat/text, and Playing Video Games) related to technology and gaming using a web-based survey). Qualitative data in the form of online blog posts was gathered during the project to assist in the triangulation and assessment of teacher efficacy. Data analyses consisted of an Analysis of Variance and serial coding of teacher reflective responses. Results indicated participants who used computers daily have higher efficacy while using inquiry-based teaching methods and science teaching and learning. Additional emergent findings revealed possible motivating factors for efficacy. This professional development project was focused on inquiry as a pedagogical strategy, standard-based science learning as means to develop content knowledge, and creating video games as technological knowledge. The project was consistent with the Technological Pedagogical Content Knowledge (TPCK) framework where overlapping circles of the three components indicates development of an integrated understanding of the suggested relationships. Findings provide suggestions for development of standards-based science education software, its integration into the curriculum and, strategies for implementing technology into teaching practices.

The impact of natural science contextual teaching through project method to students’ achievement in MTsN Miri Sragen

Directory of Open Access Journals (Sweden)

Anik Sunarsih

2017-12-01

Full Text Available This study aims to describe the science learning skills among students’ who follow contextual learning through project method with experiment method. The population of this research is the students’ of class VII MTS Negeri Miri Kab. Sragen on the teaching period of 2016/2017. Cluster random sampling technique is used as sample. This research was designed using contextual teaching through project method as an independent variable. The results of this Improvement show that there is a difference in the achievement of students' learning skill that follows contextual learning through the project method with the experimental method with Fobs = 8,83 and significant number 4,04 (p <0,05. Based on these findings contextual learning through the project is one of the learning methods that provide a positive influence on improving the achievement of science learning skills. This ain increase, because CTL is can help students’ understand the material by relating the problems that exist. Project methods are used by students’ in solving problems.

Changes in Participants’ Scientific Attitudes and Epistemological Beliefs During an Astronomical Citizen Science Project

Science.gov (United States)

Price, Aaron

2012-01-01

Citizen science projects offer opportunities for non-scientists to take part in scientific research. While their contribution to scientific data collection has been well documented, there is limited research on changes that may occur to their volunteer participants. In this study, we investigated (1) how volunteers’ attitudes towards science and beliefs in the nature of science changed over six months of participation in an astronomy-themed citizen science project and (2) how the level of project participation accounted for these changes. To measure attitudes towards science and beliefs about the nature of science, identical pre- and post-tests were used. We used pre-test data from 1,375 participants and post-test data collected from 175 participants. Responses were analyzed using the Rasch Rating Scale Model. The pre-test sample was used to create the Rasch scales for the two scientific literacy measures. For the pre/post-test comparisons, data from those who completed both tests were used. Fourteen participants who took the pre/post-tests were interviewed. Results show that overall scientific attitudes did not change, p = .812. However, we did find significant changes related towards two scientific attitude items about science in the news (positive change; p self-efficacy (negative change, p scale did not change much and this change was not related to any of our recorded project activity variables. The interviews suggest that the social aspect of the project is important to participants and the change in self-efficacy is not due to a lowering of esteem but rather a greater appreciation for what they have yet to learn.

'Adotta scienza e arte nella tua classe': The results of a successfully teaching project which combines science with art

International Nuclear Information System (INIS)

Giansanti, S.

2015-01-01

The project called 'Adotta scienza e arte nella tua classe' ('Adopt Science and Art in your class'), on the interconnection between science and art, has been addressed to the Italian secondary middle and high school involving more than 200 teachers and about 2200 students. The main purpose of this project is to make the young students aware of the strong link between science and art is a unique cultural and interdisciplinary occasion. To reach this goal, the Adotta project asked students to produce an artwork inspired by the interpretation of a quotation among a hundred commented quotes by physicists, mathematicians, scientist, writers, artists, accompanied by an original short sentence written by students themselves. More than 1000 artworks have been produced and collected in two galleries on Facebook. From their analysis emerges the students’ feeling about science, which is usually associated to human brain, based on mathematical laws and related to technological progress, but it is also a powerful tool that should be responsibly used. This project also valorizes teachers’ role in scientific education through activities that encourage students to recognize science in every aspect of their lives.

[Analysis of ophthalmic projects granted by National Natural Science Foundation].

Science.gov (United States)

Shao, Jing-Jing; Mo, Xiao-Fen; Pan, Zhi-Qiang; Gan, De-Kang; Xu, Yan-Ying

2008-09-01

To understand the status of basic research work in the field of ophthalmology by analyzing the projects funded by the National Natural Science Foundation of China (NSFC) from the year of 1986 to 2007, and offer as a reference to the ophthalmologists and researchers. NSFC supported ophthalmology projects in the 22 year's period were collected from the database of NSFC. The field of funded projects, the research team and their achievements were analyzed. There were 228 applicants from 47 home institutions were funded in the field of ophthalmology during the past 22 years, 323 projects funded with 66.74 million Yuan in total, in which 165 projects were fulfilled before the end of 2006. The applied and funded projects mainly focus on six different kinds of research area related to retinal diseases, corneal diseases, glaucoma, optic nerve diseases, myopia and cataract, and 70% of them were basic research in nature. As a brief achievement of 165 fulfilled projects, more than 610 papers were published in domestic journals, over 140 papers were published in Science Citation Index journals, more than 600 people were trained, and over 20 scientific awards were obtained. The number of funded projects and achievement of fulfilled projects in the discipline of ophthalmology gradually increased over the past two decades, the research fields were concentrated in certain diseases. NSFC has played an important role in promoting the development of ophthalmology research and bringing up specialists in China. However, clinical research, continuously research, transforming from basic research to clinic applications and multidisciplinary cross studies should be strengthened.

Conceptualizing the role of multidisciplinarity and student perceptions of university-industry collaboration in project-based learning

OpenAIRE

Heikkinen, Juho

2017-01-01

Project-based learning has a long history, especially in the disciplines of computer science and engineering. This approach is used to offer students a realistic view of their discipline, and this experience can be enhanced with industrial involvement as companies bring their real world problems to projects. One recent trend in project-based learning is utilizing multidisciplinary teams, enabling students to contrast their skills and experience with students from other discipli...

Ka Hana `Imi Na`auao: A Science Curriculum Project

Science.gov (United States)

Napeahi, K.; Roberts, K. D.; Galloway, L. M.; Stodden, R. A.; Akuna, J.; Bruno, B.

2005-12-01

In antiquity, the first people to step foot on what are now known as the Hawaiian islands skillfully traversed the Pacific Ocean using celestial navigation and learned observations of scientific phenomena. Long before the Western world ventured beyond the horizon, Hawaiians had invented the chronometer, built aqueduct systems (awai) that continue to amaze modern engineers, and had preventive health systems as well as a comprehensive knowledge of medicinal plants (including antivirals) which only now are working their way through trials for use in modern pharmacopia. Yet, today, Native Hawaiians are severely underrepresented in science-related fields, reflecting (in part) a failure of the Western educational system to nurture the potential of these resourceful students, particularly the many "at-risk" students who are presently over-represented in special education. A curriculum which draws from and incorporates traditional Hawaiian values and knowledge is needed to reinforce links to the inquiry process which nurtured creative thinking during the renaissance of Polynesian history. The primary goal of the Ka Hana `Imi Na`auao Project (translation: `science` or `work in which you seek enlightenment, knowledge or wisdom`) is to increase the number of Native Hawaiian adults in science-related postsecondary education and employment fields. Working closely with Native Hawaiian cultural experts and our high school partners, we will develop and implement a culturally responsive 11th and 12th grade high school science curriculum, infused with math, literacy and technology readiness skills. Software and assistive technology will be used to adapt instruction to individual learners` reading levels, specific disabilities and learning styles. To ease the transition from secondary to post-secondary education, selected grade 12 students will participate in planned project activities that link high school experiences with college science-related programs of study. Ka Hana `Imi Na

Teacher Perceptions of Their Curricular and Pedagogical Shifts: Outcomes of a Project-Based Model of Teacher Professional Development in the Next Generation Science Standards

OpenAIRE

David J. Shernoff; David J. Shernoff; Suparna Sinha; Denise M. Bressler; Dawna Schultz

2017-01-01

In this study, we conducted a model of teacher professional development (PD) on the alignment of middle and high school curricula and instruction to the Next Generation Science Standards (NGSSs), and evaluated the impact of the PD on teacher participants’ development. The PD model included a 4-day summer academy emphasizing project-based learning (PBL) in the designing of NGSS-aligned curricula and instruction, as well as monthly follow-up Professional Learning Community meetings throughout t...

Development and implementation of a science training course for breast cancer activists: Project LEAD (leadership, education and advocacy development).

Science.gov (United States)

Dickersin, K; Braun, L; Mead, M; Millikan, R; Wu, A M; Pietenpol, J; Troyan, S; Anderson, B; Visco, F

2001-12-01

To develop and implement Project LEAD (leadership, education, and advocacy development), a science course for breast cancer activists. Students were breast cancer activists and other consumers, mainly affiliated with advocacy organizations in the United States of America. Project LEAD is offered by the National Breast Cancer Coalition; the course takes place over 5 days and is offered 4 times a year, in various cities in the United States of America. The Project LEAD curriculum has developed over 5 years to include lectures, problem-based study groups, case studies, interactive critical appraisal sessions, a seminar by an 'expert' scientist, role play, and homework components. A core faculty has been valuable for evaluating and revising the course and has proved necessary to provide consistent high quality teaching. Course evaluations indicated that students gained critical appraisal skills, enhanced their knowledge and developed confidence in selected areas of basic science and epidemiology. Project LEAD comprises a unique curriculum for training breast cancer activists in science and critical appraisal. Course evaluations indicate that students gain confidence and skills from the course.

Research as Praxis: Perspectives on Interpreting Data from a Science and Indigenous Knowledge Systems Project

Science.gov (United States)

Nhalevilo, Emilia Afonso; Ogunniyi, Meshach

2014-01-01

This article presents a reflection on an aspect of research methodology, particularly on the interpretation strategy of data from a Science and Indigenous Knowledge Systems Project (SIKSP) in a South African university. The data interpretation problem arose while we were analysing the effects of a series of SIKSP-based workshops on the views of a…

Science Opens Doors

Science.gov (United States)

Smyth, Steve; Smyth, Jen

2016-01-01

Science Opens Doors is the creation of Clive Thompson of the Horners' Livery Company. The Science Opens Doors project philosophy is strongly based upon the King's College London ASPIRES project, which established that children like doing science in junior school (ages 7-11), but that by the age of 12-14 they are firmly against becoming scientists.…

The epistemic culture in an online citizen science project: Programs, antiprograms and epistemic subjects.

Science.gov (United States)

Kasperowski, Dick; Hillman, Thomas

2018-05-01

In the past decade, some areas of science have begun turning to masses of online volunteers through open calls for generating and classifying very large sets of data. The purpose of this study is to investigate the epistemic culture of a large-scale online citizen science project, the Galaxy Zoo, that turns to volunteers for the classification of images of galaxies. For this task, we chose to apply the concepts of programs and antiprograms to examine the 'essential tensions' that arise in relation to the mobilizing values of a citizen science project and the epistemic subjects and cultures that are enacted by its volunteers. Our premise is that these tensions reveal central features of the epistemic subjects and distributed cognition of epistemic cultures in these large-scale citizen science projects.

Field Studies in Science Teacher Preparation Programs: Examples of Research-Oriented Earth and Environmental Science Field Projects for Pre-service and In-service Teachers

Science.gov (United States)

O'Neal, M. L.

2005-12-01

Science teaching reforms of the past 10 to 20 years have focused on a pedagogical shift from verification-style laboratory exercises, toward hands-on and inquiry-based constructivist teaching methods. Such methods, however, require teachers to be proficient in more than just basic content and teaching strategies. To be effective teachers, these professionals must also be skilled in the design and implementation of research-style investigations. At Loyola College in Maryland, topics in the earth and environmental sciences are used as the basis for field research projects that teach our students science content, along with how to design age-appropriate investigative activities and how to implement them in a stimulating, inquiry-based learning environment. Presented here are examples of three projects, demonstrating how these themes are woven throughout our pre- and in-service teacher preparation programs, at both undergraduate and graduate levels. 1. Watershed Studies - In our undergraduate, pre-service, elementary education teacher preparation program, students design and implement a water quality study in a local watershed. In the classroom, students use topographic maps and aerial photographs to delineate the watersheds' boundaries, to identify current land use patterns, and to select appropriate locations on the trunk stream for testing. Water testing at these sites is conducted during field trips, with data analysis and interpretation performed on-site. On-site work allows students to make connections between stream water quality and adjacent land use practices. Students then relate the content and research results to science teaching standards, in order to develop a unit-plan for use in their future classrooms. 2. Land Use Assessment - In our graduate, in-service, elementary and middle school science program, a local stream valley is used as the basis for an analysis of potential land use changes. Students first construct a topographic base map of the area, and

"Crystals within Crystals: The Story of Sea Ice". A Classroom-Based Outreach Project Communicating Cutting-Edge Ocean Science to School Pupils

Science.gov (United States)

Butler, B.

2016-02-01

'Crystals within Crystals: The story of sea ice' is a UK based outreach project based that uses a range practical tools to engage school students with cutting edge scientific research that relates to the use of some of the world's most powerful X-rays in sea ice research. The project is delivered in the form of a classroom workshop that first introduces school pupils (aged 11-14) to seawater and the salts that give it a salinity. The pupils are then shown how the presence of salts within seawater results in very important physical changes when the liquid freezes, which includes different structural and optical properties of the ice. The properties of the ice are then linked to the presence of countless microscopic salt crystals that are trapped within the microstructure of the frozen seawater, which is explained with use of a novel crystal growth demonstration. Given that there is currently no way of successfully removing these salt crystals from the ice, the workshop culminates in explaining how some of the worlds most powerful X-rays can be used to investigate processes that otherwise remain elusive. The workshop introduces students to the fundamental principles of scientific enquiry, the sea ice environment, and the power of X-rays in investigating the properties of crystals. Here we present information that outlines a host of practical and project management tools that are applicacble to outreach projects in the the field of ocean sciences, with the aim of seeding ideas and interest for other graduate student to enage with the public during their studies.

Game-based Research Collaboration adapted to Science Education

DEFF Research Database (Denmark)

Magnussen, Rikke; Damgaard Hansen, Sidse; Grønbæk, Kaj

2012-01-01

This paper presents prospects for adapting scientific discovery games to science education. In the paper a prototype of The Quantum Computing Game is presented as a working example of adapting game-based research collaboration to physics education. The game concept is the initial result of a three......-year, inter-disciplinary project “Pilot Center for Community-driven Research” at Aarhus and Aalborg University in Denmark. The paper discusses how scientific discovery games can contribute to educating students in how to work with unsolved scientific problems and creation of new scientific knowledge. Based...

Changes in Participants' Scientific Attitudes and Epistemological Beliefs during an Astronomical Citizen Science Project

Science.gov (United States)

Price, C. Aaron; Lee, Hee-Sun

2013-01-01

Citizen science projects provide non-scientists with opportunities to take part in scientific research. While their contribution to scientific data collection has been well documented, there is limited research on how participation in citizen science projects may affect their scientific literacy. In this study, we investigated (1) how volunteers'…

Frames for Learning Science: Analyzing Learner Positioning in a Technology-Enhanced Science Project

Science.gov (United States)

Silseth, K.; Arnseth, H. C.

2016-01-01

In this article, we examine the relationship between how students are positioned in social encounters and how this influences learning in a technology-supported science project. We pursue this topic by focusing on the participation trajectory of one particular learner. The analysis shows that the student cannot be interpreted as one type of…

ENSAR, a Nuclear Science Project for European Research Area

NARCIS (Netherlands)

Turzó, Ketel; Lewitowicz, Marek; Harakeh, Muhsin N.

2015-01-01

During the period from September 2010 to December 2014, the European project European Nuclear Science and Applications Research (ENSAR) coordinated research activities of the Nuclear Physics community performing research in three major subfields: Nuclear Structure, Nuclear Astrophysics, and Nuclear

Science in Hawaii/Haawina Hoopapau: A Culturally Responsive Curriculum Project

Science.gov (United States)

Galloway, L. M.; Roberts, K.; Leake, D. W.; Stodden, R. S.; Crabbe, V.

2005-12-01

The marvels of modern science often fail to engage indigenous students, as the content and instructional style are usually rooted in the Western experience. This 3 year project, funded by the US Dept. of Education for the Education of Native Hawaiians, offers a curriculum that teaches science through (rather than just about) Native Hawaiian culture. The curriculum focuses on the interdependence of natural resources in our ahupuaa, or watersheds, and helps students strengthen their sense of place and self to malama i ka aina, to care for the land. Further, the curriculum is designed to: engage students in scientific study with relevant, interesting content and activities; improve student achievement of state department of education standards; increase student knowledge and skills in science, math and language arts; respond to the learning needs of Native Hawaiian and/or at-risk students. The project will be presented by a curriculum writer who created and adapted more than a year's worth of materials by teaming with kupuna (respected elders), local cultural experts and role models, educators (new, veteran, Hawaiian, non-Hawaiian, mainland, general and special education teachers), and professionals at the Center on Disability Studies at the University of Hawaii and ALU LIKE, Inc, a non-profit organization to assist Native Hawaiians. The materials created thus far are available for viewing at: www.scihi.hawaii.edu The curriculum, designed for grades 8-11 science classes, can be used to teach a year-long course, a unit, or single lesson related to astronomy, biology, botany, chemistry, geology, oceanography, physical and environmental sciences. This project is in its final year of field testing, polishing and dissemination, and therefore this session will encourage idea sharing, as does our copyright free Web site.

Mechanical Properties in a Bamboo Fiber/PBS Biodegradable Composite

Science.gov (United States)

Ogihara, Shinji; Okada, Akihisa; Kobayashi, Satoshi

In recent years, biodegradable plastics which have low effect on environment have been developed. However, many of them have lower mechanical properties than conventional engineering plastics. Reinforcing them with a natural fiber is one of reinforcing methods without a loss of their biodegradability. In the present study, we use a bamboo fiber as the reinforcement and polybutylenesuccinate (PBS) as the matrix. We fabricate long fiber unidirectional composites and cross-ply laminate with different fiber weight fractions (10, 20, 30, 40 and 50wt%). We conduct tensile tests to evaluate the mechanical properties of these composites. In addition, we measure bamboo fiber strength distribution. We discuss the experimentally-obtained properties based on the mechanical properties of the constituent materials. Young's modulus and tensile strength in unidirectional composite and cross-ply laminate increase with increasing fiber weight fraction. However, the strain at fracture showed decreasing tendency. Young's modulus in fiber and fiber transverse directions are predictable by the rules of mixture. Tensile strength in fiber direction is lower than Curtin's prediction of strength which considers distribution of fiber strength. Young's modulus in cross-ply laminate is predictable by the laminate theory. However, analytical prediction of Poisson's ratio in cross-ply laminate by the laminate theory is lower than the experimental results.

Science in Action: How Middle School Students Are Changing Their World through STEM Service-Learning Projects

Science.gov (United States)

Newman, Jane L.; Dantzler, John; Coleman, April N.

2015-01-01

The purpose of Science in Action (SIA) was to examine the relationship between implementing quality science, technology, engineering, and math (STEM) service-learning (SL) projects and the effect on students' academic engagement in middle school science, civic responsibility, and resilience to at-risk behaviors. The innovative project funded by…

A National contribution to the GEO Science and Technology roadmap: GIIDA Project

Science.gov (United States)

Nativi, Stefano; Mazzetti, Paolo; Guzzetti, Fausto; Oggioni, Alessandro; Pirrone, Nicola; Santolieri, Rosalia; Viola, Angelo; Tartari, Gianni; Santoro, Mattia

2010-05-01

The GIIDA (Gestione Integrata e Interoperativa dei Dati Ambientali) project is an initiative of the Italian National Research Council (CNR) launched in 2008 as an inter-departmental project, aiming to design and develop a multidisciplinary e-infrastructure (cyber-infrastructure) for the management, processing, and evaluation of Earth and Environmental resources -i.e. data, services, models, sensors, best practices. GIIDA has been contributing to the implementation of the GEO (Group of Earth Observation) Science and Technology (S&T) roadmap by: (a) linking relevant S&T communities to GEOSS (GEO System of Systems); (b) ensuring that GEOSS is built based on state-of-the-art science and technology. GIIDA co-ordinates the CNR's digital infrastructure development for Earth Observation resources sharing and cooperates with other national agencies and existing projects pursuing the same objective. For the CNR, GIIDA provides an interface to European and international interoperability programmes (e.g. INSPIRE, and GMES). It builds a national network for dialogue and resolution of issues at varying scientific and technical levels. To achieve such goals, GIIDA introduced a set of guidance principles: • To shift from a "traditional" data centric approach to a more advanced service-based solution for Earth System Science and Environmental information. • To shift the focus from Data to Information Spatial Infrastructures in order to support decision-making. • To be interoperable with analogous National (e.g. SINAnet, and the INSPIRE National Infrastructure) and international initiatives (e.g. INSPIRE, GMES, SEIS, and GEOSS). • To reinforce the Italian presence in the European and international programmes concerning digital infrastructures, geospatial information, and the Mega-Science approach. • To apply the National and International Information Technology (IT) standards for achieving multi-disciplinary interoperability in the Earth and Space Sciences (e.g. ISO, OGC

Decoration of PbS nanoparticles on Al-doped ZnO nanorod array thin film with hydrogen treatment as a photoelectrode for solar water splitting

Energy Technology Data Exchange (ETDEWEB)

Hsu, Chih-Hsiung; Chen, Chao-Hong [Department of Chemical Engineering and Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan 701, Taiwan, ROC (China); Chen, Dong-Hwang, E-mail: chendh@mail.ncku.edu.tw [Department of Chemical Engineering and Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan 701, Taiwan, ROC (China)

2013-03-25

Highlights: ► AZO nanorod array thin film is used as a photoanode for solar water splitting. ► Hydrogen treatment and sensitization by PbS nanoparticles enhance photocurrent. ► A novel ITO/FTO-free composite photoelectrode is developed. ► The pre-fabrication and use of an extra TCO thin film substrate is unnecessary. -- Abstract: Al-doped ZnO (AZO) nanorod arrays thin film with hydrogen treatment is directly used as a photoelectrode for solar water splitting without an extra transparent conducting oxide (TCO) thin film because it possesses the functions of TCO thin film and photoactive 1-dimensional nanostructured semiconductor simultaneously. To enhance the absorption in the visible region, PbS nanoparticles decorated the AZO nanorods via successive ionic layer adsorption and reaction route. The PbS nanoparticles have a face-centered cubic structure and their decoration does not destroy the 1-dimensional morphology of AZO nanorod arrays. With increasing the cycle number of PbS nanoparticles decoration, the grain size and loading of PbS nanoparticles become larger gradually which leads to lower energy bandgap and stronger absorption. A maximum photocurrent density of 1.65 mW cm{sup −2} is obtained when the cycle number is 20, which is much higher than those without PbS nanoparticles sensitization or hydrogen treatment. This demonstrates that the AZO nanorod array thin film with hydrogen treatment can be directly used as a photoelectrode without an extra TCO thin film. Because the use of expensive metals can be avoided and the pre-fabrication of TCO thin film substrate is necessary no more, the fabrication of such a composite photoelectrode becomes simple and low-cost. So, it has great potentials in solar water splitting after sensitization by quantum dots capable of visible light absorption.

The Ins & Outs of Developing a Field-Based Science Project: Learning by Lassoing Lizards

Science.gov (United States)

Matthews, Catherine E.; Huffling, Lacey D.; Benavides, Aerin

2014-01-01

We describe a field-based lizard project we did with high school students as a part of our summer Herpetological Research Experiences. We describe data collection on lizards captured, identified, and marked as a part of our mark-recapture study. We also describe other lizard projects that are ongoing in the United States and provide resources for…

Planetary Balloon-Based Science Platform Evaluation and Program Implementation

Science.gov (United States)

Dankanich, John W.; Kremic, Tibor; Hibbitts, Karl; Young, Eliot F.; Landis, Rob

2016-01-01

This report describes a study evaluating the potential for a balloon-based optical telescope as a planetary science asset to achieve decadal class science. The study considered potential science achievable and science traceability relative to the most recent planetary science decadal survey, potential platform features, and demonstration flights in the evaluation process. Science Potential and Benefits: This study confirms the cost the-benefit value for planetary science purposes. Forty-four (44) important questions of the decadal survey are at least partially addressable through balloon based capabilities. Planetary science through balloon observations can provide significant science through observations in the 300 nm to 5 m range and at longer wavelengths as well. Additionally, balloon missions have demonstrated the ability to progress from concept to observation to publication much faster than a space mission increasing the speed of science return. Planetary science from a balloon-borne platform is a relatively low-cost approach to new science measurements. This is particularly relevant within a cost-constrained planetary science budget. Repeated flights further reduce the cost of the per unit science data. Such flights offer observing time at a very competitive cost. Another advantage for planetary scientists is that a dedicated asset could provide significant new viewing opportunities not possible from the ground and allow unprecedented access to observations that cannot be realized with the time allocation pressures faced by current observing assets. In addition, flight systems that have a relatively short life cycle and where hardware is generally recovered, are excellent opportunities to train early career scientists, engineers, and project managers. The fact that balloon-borne payloads, unlike space missions, are generally recovered offers an excellent tool to test and mature instruments and other space craft systems. Desired Gondola Features: Potential

A rural virtual health sciences library project: research findings with implications for next generation library services.

Science.gov (United States)

Richwine, M P; McGowan, J J

2001-01-01

The Shared Hospital Electronic Library of Southern Indiana (SHELSI) research project was designed to determine whether access to a virtual health sciences library and training in its use would support medical decision making in rural southern Indiana and achieve the same level of impact seen by targeted information services provided by health sciences librarians in urban hospitals. Based on the results of a needs assessment, a virtual medical library was created; various levels of training were provided. Virtual library users were asked to complete a Likert-type survey, which included questions on intent of use and impact of use. At the conclusion of the project period, structured interviews were conducted. Impact of the virtual health sciences library showed a strong correlation with the impact of information provided by health sciences librarians. Both interventions resulted in avoidance of adverse health events. Data collected from the structured interviews confirmed the perceived value of the virtual library. While librarians continue to hold a strong position in supporting information access for health care providers, their roles in the information age must begin to move away from providing information toward selecting and organizing knowledge resources and instruction in their use.

Charge transfer between acenes and PbS nanocrystals

Energy Technology Data Exchange (ETDEWEB)

Dissanayake, D M N M [Solid State Electronics Laboratory, University of Michigan, Ann Arbor, MI 48109-2122 (United States); Hatton, R A [Department of Chemistry, University of Warwick, Coventry CV4 7AL (United Kingdom); Lutz, T [Departments of Chemistry and Physics, Imperial College, London SW7 2AY (United Kingdom); Curry, R J; Silva, S R P [Advanced Technology Institute, University of Surrey, Guildford GU2 7XH (United Kingdom)], E-mail: ndissa@umich.edu

2009-05-13

Organic-inorganic hybrid heterojunctions have potential as the basis for future photovoltaic devices. Herein, we report the results of investigations exploring the possibility of using pentacene and tetracene as photoelectron donors in conjunction with PbS nanocrystals (PbS-NCs). Photoinduced charge transfer was probed using external quantum efficiency measurements on acene:PbS-NC hybrid photovoltaic devices in conjunction with photoluminescence studies of the corresponding bilayer films. It is shown that photoelectron transfer from pentacene to the PbS-NCs is inefficient as compared to that between tetracene and PbS-NCs. The latter case can be rationalized in terms of the energy level alignment at the heterojunction assuming a common vacuum level. However, in the case of pentacene:PbS-NC junctions an interfacial energy level shift must be considered in order to explain the observations.

A Project-Based Engineering and Leadership Workshop for High School Students

Science.gov (United States)

Ryder, Linda Sue; Pegg, Jerine; Wood, Nathan

2012-01-01

Summer outreach programs provide pre-college participants an introduction to college life and exposure to engineering in an effort to raise the level of interest and bring more students into engineering fields. The Junior Engineering, Mathematics, and Science (JEMS) program is a project-based summer workshop in which teams of high school students…

Math Path: Encouraging Female Students in Mathematics through Project-Based Learning

Science.gov (United States)

Evans, Riley; Friedman, Jane; McGrath, Lynn; Myers, Perla; Ruiz, Amanda

2018-01-01

Although the number of bachelor's degrees in the U.S. awarded to women has gone up, engagement of women in science, technology, engineering, and mathematics (STEM) continues to be low. This paper presents a project-based learning program, informed by education research best practices, designed to provide research experiences to female students…

Implementation of inquiry-based science education in different countries: some reflections

Science.gov (United States)

Rundgren, Carl-Johan

2017-03-01

In this forum article, I reflect on issues related to the implementation of inquiry-based science education (IBSE) in different countries. Regarding education within the European Union (EU), the Bologna system has in later years provided extended coordination and comparability at an organizational level. However, the possibility of the EU to influence the member countries regarding the actual teaching and learning in the classrooms is more limited. In later years, several EU-projects focusing on IBSE have been funded in order to make science education in Europe better, and more motivating for students. Highlighting what Heinz and her colleagues call the policy of `soft governance' of the EU regarding how to improve science education in Europe, I discuss the focus on IBSE in the seventh framework projects, and how it is possible to maintain more long-lasting results in schools through well-designed teacher professional development programs. Another aspect highlighted by Heinz and her colleagues is how global pressures on convergence in education interact with educational structures and traditions in the individual countries. The rise of science and science education as a global culture, encompassing contributions from all around the world, is a phenomenon of great potential and value to humankind. However, it is important to bear in mind that if science and science education is going to become a truly global culture, local variation and differences regarding foci and applications of science in different cultures must be acknowledged.

A Multi-mission Event-Driven Component-Based System for Support of Flight Software Development, ATLO, and Operations first used by the Mars Science Laboratory (MSL) Project

Science.gov (United States)

Dehghani, Navid; Tankenson, Michael

2006-01-01

This viewgraph presentation reviews the architectural description of the Mission Data Processing and Control System (MPCS). MPCS is an event-driven, multi-mission ground data processing components providing uplink, downlink, and data management capabilities which will support the Mars Science Laboratory (MSL) project as its first target mission. MPCS is designed with these factors (1) Enabling plug and play architecture (2) MPCS has strong inheritance from GDS components that have been developed for other Flight Projects (MER, MRO, DAWN, MSAP), and are currently being used in operations and ATLO, and (3) MPCS components are Java-based, platform independent, and are designed to consume and produce XML-formatted data

Entwicklung eines Summenparameters für potenziell bioakkumulierbare Stoffe (PBS) im Abwasser

OpenAIRE

Stenz, Georg

2001-01-01

Es wurde ein Summenparameter für potenziell bioakkumulierbare Stoffe (PBS) im Abwasser entwickelt. Der Summenparameter soll als Instrumentarium zur Überwachung von Einleitungen, Emissionen und Verlusten an anreicherungsfähigen Stoffen eingesetzt werden, da die Bioakkumulation besonders für marine Ökosysteme ein Gefährdungskriterium darstellt. Stoffe werden nach dem „Technical Guidance Document (TGD)“ als potenziell bioakkumulierbar bertrachtet, wenn deren log POW-Wert größer als drei ist. Der...

Heterojunction PbS nanocrystal solar cells with oxide charge-transport layers.

Science.gov (United States)

Hyun, Byung-Ryool; Choi, Joshua J; Seyler, Kyle L; Hanrath, Tobias; Wise, Frank W

2013-12-23

Oxides are commonly employed as electron-transport layers in optoelectronic devices based on semiconductor nanocrystals, but are relatively rare as hole-transport layers. We report studies of NiO hole-transport layers in PbS nanocrystal photovoltaic structures. Transient fluorescence experiments are used to verify the relevant energy levels for hole transfer. On the basis of these results, planar heterojunction devices with ZnO as the photoanode and NiO as the photocathode were fabricated and characterized. Solution-processed devices were used to systematically study the dependence on nanocrystal size and achieve conversion efficiency as high as 2.5%. Optical modeling indicates that optimum performance should be obtained with thinner oxide layers than can be produced reliably by solution casting. Room-temperature sputtering allows deposition of oxide layers as thin as 10 nm, which enables optimization of device performance with respect to the thickness of the charge-transport layers. The best devices achieve an open-circuit voltage of 0.72 V and efficiency of 5.3% while eliminating most organic material from the structure and being compatible with tandem structures.

The Navajo Learning Network and the NASA Life Sciences/AFOSR Infrastructure Development Project

Science.gov (United States)

1999-01-01

The NSF-funded Navajo Learning Network project, with help from NASA Life Sciences and AFOSR, enabled Dine College to take a giant leap forward technologically - in a way that could never had been possible had these projects been managed separately. The combination of these and other efforts created a network of over 500 computers located at ten sites across the Navajo reservation. Additionally, the college was able to install a modern telephone system which shares network data, and purchase a new higher education management system. The NASA Life Sciences funds further allowed the college library system to go online and become available to the entire campus community. NSF, NASA and AFOSR are committed to improving minority access to higher education opportunities and promoting faculty development and undergraduate research through infrastructure support and development. This project has begun to address critical inequalities in access to science, mathematics, engineering and technology for Navajo students and educators. As a result, Navajo K-12 education has been bolstered and Dine College will therefore better prepare students to transfer successfully to four-year institutions. Due to the integration of the NSF and NASA/AFOSR components of the project, a unified project report is appropriate.

System engineering and science projects: lessons from MeerKAT

Science.gov (United States)

Kapp, Francois