Student conceptions of the nature of science

NASA Astrophysics Data System (ADS)

Talbot, Amanda L.

Research has shown that students from elementary school to college have major misconceptions about the nature of science. While an appropriate understanding of the nature of science has been an objective of science education for a century, researchers using a variety of instruments, continue to document students' inadequate conceptions of what science is and how it operates as an enterprise. Current research involves methods to improve student understanding of the nature of science. Students often misunderstand the creative, subjective, empirical, and tentative nature of science. They do not realize the relationship between laws and theories, nor do they understand that science does not follow a prescribed method. Many do not appreciate the influence culture, society, and politics; nor do they have an accurate understanding of the types of questions addressed by science. This study looks at student understanding of key nature of science (NOS) concepts in order to examine the impact of implementing activities intended to help students better understand the process of science and to see if discussion of key NOS concepts following those activities will result in greater gains in NOS understanding. One class received an "activities only" treatment, while the other participated in the same activities followed by explicit discussion of key NOS themes relating to the activity. The interventions were implemented for one school year in two high school anatomy and physiology courses composed of juniors and seniors. Student views of the nature of science were measured using the Views of the Nature of Science-Form C (VNOS-C). Students in both classes demonstrated significant gains in NOS understanding. However, contrary to current research, the addition of explicit discussion did not result in significantly greater gains in NOS understanding. This suggests that perhaps students in higher-level science classes can draw the correlations between NOS related activities and

Developing an instrument for assessing students' concepts of the nature of technology

NASA Astrophysics Data System (ADS)

Liou, Pey-Yan

2015-05-01

Background:The nature of technology has been rarely discussed despite the fact that technology plays an essential role in modern society. It is important to discuss students' concepts of the nature of technology, and further to advance their technological literacy and adaptation to modern society. There is a need to assess high school students' concepts of the nature of technology. Purpose:This study aims to engage in discourse on students' concepts of the nature of technology based on a proposed theoretical framework. Moreover, another goal is to develop an instrument for measuring students' concepts of the nature of technology. Sample:Four hundred and fifty-five high school students' perceptions of technology were qualitatively analyzed. Furthermore, 530 students' responses to a newly developed questionnaire were quantitatively analyzed in the final test. Design and method:First, content analysis was utilized to discuss and categorize students' statements regarding technology and its related issues. The Student Concepts of the Nature of Technology Questionnaire was developed based on the proposed theoretical framework and was supported by the students' qualitative data. Finally, exploratory factor analysis and reliability analysis were applied to determine the structure of the items and the internal consistency of each scale. Results:Through a process of instrument development, the Student Concepts of the Nature of Technology Questionnaire was shown to be a valid and reliable tool for measuring students' concepts of the nature of technology. This newly developed questionnaire is composed of 29 items in six scales, namely 'technology as artifacts,' 'technology as an innovation change,' 'the current role of technology in society,' 'technology as a double-edged sword,' 'technology as a science-based form,' and 'history of technology.' Conclusions:The Student Concepts of the Nature of Technology Questionnaire has been confirmed as a reasonably valid and reliable

Looking to nature for solutions

NASA Astrophysics Data System (ADS)

Turner, Will R.

2018-01-01

Completely stopping fossil fuel use may not be enough to avoid dangerous climate change. Recent research on the mitigation potential of conservation, restoration, and improved land management demonstrates that natural solutions can reduce emissions and remove atmospheric CO2 while safeguarding food security and biodiversity.

"The City Snuffs out Nature": Young People's Conceptions of and Relationship with Nature

ERIC Educational Resources Information Center

Pointon, Pam

2014-01-01

This paper reports a study of 384 13-14-year olds' written responses to open-ended questions about their understanding of and relationship with "nature." Using constant comparative method the responses were coded, categorised and themed. Most students held scientific conceptions of nature (excluding humans) and a utilitarian relationship…

Possible Solutions as a Concept in Behavior Change Interventions.

PubMed

Mahoney, Diane E

2018-04-24

Nurses are uniquely positioned to implement behavior change interventions. Yet, nursing interventions have traditionally resulted from nurses problem-solving rather than allowing the patient to self-generate possible solutions for attaining specific health outcomes. The purpose of this review is to clarify the meaning of possible solutions in behavior change interventions. Walker and Avant's method on concept analysis serves as the framework for examination of the possible solutions. Possible solutions can be defined as continuous strategies initiated by patients and families to overcome existing health problems. As nurses engage in behavior change interventions, supporting patients and families in problem-solving will optimize health outcomes and transform clinical practice. © 2018 NANDA International, Inc.

Natural climate solutions

NASA Astrophysics Data System (ADS)

Griscom, Bronson W.; Adams, Justin; Ellis, Peter W.; Houghton, Richard A.; Lomax, Guy; Miteva, Daniela A.; Schlesinger, William H.; Shoch, David; Siikamäki, Juha V.; Smith, Pete; Woodbury, Peter; Zganjar, Chris; Blackman, Allen; Campari, João; Conant, Richard T.; Delgado, Christopher; Elias, Patricia; Gopalakrishna, Trisha; Hamsik, Marisa R.; Herrero, Mario; Kiesecker, Joseph; Landis, Emily; Laestadius, Lars; Leavitt, Sara M.; Minnemeyer, Susan; Polasky, Stephen; Potapov, Peter; Putz, Francis E.; Sanderman, Jonathan; Silvius, Marcel; Wollenberg, Eva; Fargione, Joseph

2017-10-01

Better stewardship of land is needed to achieve the Paris Climate Agreement goal of holding warming to below 2 °C; however, confusion persists about the specific set of land stewardship options available and their mitigation potential. To address this, we identify and quantify “natural climate solutions” (NCS): 20 conservation, restoration, and improved land management actions that increase carbon storage and/or avoid greenhouse gas emissions across global forests, wetlands, grasslands, and agricultural lands. We find that the maximum potential of NCS—when constrained by food security, fiber security, and biodiversity conservation—is 23.8 petagrams of CO2 equivalent (PgCO2e) y‑1 (95% CI 20.3–37.4). This is ≥30% higher than prior estimates, which did not include the full range of options and safeguards considered here. About half of this maximum (11.3 PgCO2e y‑1) represents cost-effective climate mitigation, assuming the social cost of CO2 pollution is ≥100 USD MgCO2e‑1 by 2030. Natural climate solutions can provide 37% of cost-effective CO2 mitigation needed through 2030 for a >66% chance of holding warming to below 2 °C. One-third of this cost-effective NCS mitigation can be delivered at or below 10 USD MgCO2‑1. Most NCS actions—if effectively implemented—also offer water filtration, flood buffering, soil health, biodiversity habitat, and enhanced climate resilience. Work remains to better constrain uncertainty of NCS mitigation estimates. Nevertheless, existing knowledge reported here provides a robust basis for immediate global action to improve ecosystem stewardship as a major solution to climate change.

Natural climate solutions

PubMed Central

Adams, Justin; Ellis, Peter W.; Houghton, Richard A.; Lomax, Guy; Miteva, Daniela A.; Schlesinger, William H.; Shoch, David; Siikamäki, Juha V.; Smith, Pete; Woodbury, Peter; Zganjar, Chris; Blackman, Allen; Campari, João; Conant, Richard T.; Delgado, Christopher; Elias, Patricia; Gopalakrishna, Trisha; Hamsik, Marisa R.; Herrero, Mario; Kiesecker, Joseph; Landis, Emily; Laestadius, Lars; Leavitt, Sara M.; Minnemeyer, Susan; Polasky, Stephen; Potapov, Peter; Putz, Francis E.; Sanderman, Jonathan; Silvius, Marcel; Wollenberg, Eva; Fargione, Joseph

2017-01-01

Better stewardship of land is needed to achieve the Paris Climate Agreement goal of holding warming to below 2 °C; however, confusion persists about the specific set of land stewardship options available and their mitigation potential. To address this, we identify and quantify “natural climate solutions” (NCS): 20 conservation, restoration, and improved land management actions that increase carbon storage and/or avoid greenhouse gas emissions across global forests, wetlands, grasslands, and agricultural lands. We find that the maximum potential of NCS—when constrained by food security, fiber security, and biodiversity conservation—is 23.8 petagrams of CO2 equivalent (PgCO2e) y−1 (95% CI 20.3–37.4). This is ≥30% higher than prior estimates, which did not include the full range of options and safeguards considered here. About half of this maximum (11.3 PgCO2e y−1) represents cost-effective climate mitigation, assuming the social cost of CO2 pollution is ≥100 USD MgCO2e−1 by 2030. Natural climate solutions can provide 37% of cost-effective CO2 mitigation needed through 2030 for a >66% chance of holding warming to below 2 °C. One-third of this cost-effective NCS mitigation can be delivered at or below 10 USD MgCO2−1. Most NCS actions—if effectively implemented—also offer water filtration, flood buffering, soil health, biodiversity habitat, and enhanced climate resilience. Work remains to better constrain uncertainty of NCS mitigation estimates. Nevertheless, existing knowledge reported here provides a robust basis for immediate global action to improve ecosystem stewardship as a major solution to climate change. PMID:29078344

Student concepts of Natural Selection from a resource-based perspective

NASA Astrophysics Data System (ADS)

Benjamin, Scott Shawn

The past two decades have produced a substantial amount of research about the teaching and learning of evolution; however, recent research often lacks a theoretical foundation. Application of a new theoretical framework could help fill the void and improve research about student concepts of evolution. This study seeks to show that a resource-based framework (Hammer et al., 2005) can improve research into student concepts of natural selection. Concepts of natural selection from urban community college students were assessed via qualitative (interviews, written open-response questions, and write/think aloud procedures) and quantitative methods (coded open response analysis, Concept Inventory for Natural Selection (CINS)(Anderson, Fisher, & Norman, 2002). Results showed that students demonstrate four important aspects of resource-based framework: the multi-faceted construction of concepts, context sensitivity/ concept flexibility, at-the-moment activation of resources, and perceptual frames. In open response assessment, evolutionary-gain responses produced significantly different responses than evolutionary-loss questions with: 1) significantly more correct answers for the gain than loss question (Wilcoxon signed rank test, z = -3.68, p=0.0002); 2) more Lamarckian responses to loss than the gain question (Fisher exact, p=0.0039); and significantly different distributions in expanded need vs basic need answers (Fishers exact, p = 0.02). Results from CINS scores showed significant differences in post activity scores between students that held different naive concepts associated with origin of variation, origin of species, differential reproduction, and limited survival suggesting that some naive ideas facilitate learning. Outcomes also suggest that an everyday or self-experience typological perceptual frame is an underlying source of many incorrect ideas about evolution. Interview and write/think aloud assessments propose four process resources applied by students as

Eulerian-Lagrangian solution of the convection-dispersion equation in natural coordinates

USGS Publications Warehouse

Cheng, Ralph T.; Casulli, Vincenzo; Milford, S. Nevil

1984-01-01

The vast majority of numerical investigations of transport phenomena use an Eulerian formulation for the convenience that the computational grids are fixed in space. An Eulerian-Lagrangian method (ELM) of solution for the convection-dispersion equation is discussed and analyzed. The ELM uses the Lagrangian concept in an Eulerian computational grid system. The values of the dependent variable off the grid are calculated by interpolation. When a linear interpolation is used, the method is a slight improvement over the upwind difference method. At this level of approximation both the ELM and the upwind difference method suffer from large numerical dispersion. However, if second-order Lagrangian polynomials are used in the interpolation, the ELM is proven to be free of artificial numerical dispersion for the convection-dispersion equation. The concept of the ELM is extended for treatment of anisotropic dispersion in natural coordinates. In this approach the anisotropic properties of dispersion can be conveniently related to the properties of the flow field. Several numerical examples are given to further substantiate the results of the present analysis.

What's Natural about Nature? Deceptive Concepts in Socio-Scientific Decision-Making

ERIC Educational Resources Information Center

Lindahl, Mats Gunnar; Linder, Cedric

2015-01-01

The conflicts between nature and nurture are brought to the fore and challenges socio-scientific decision-making in science education. The multitude of meanings of these concepts and their roles in societal discourses can impede students' development of understanding for different perspectives, e.g. on gene technology. This study problematizes…

Exploring Prospective Teachers' Worldviews and Conceptions of Nature of Science

ERIC Educational Resources Information Center

Liu, Shiang-Yao; Lederman, Norman G.

2007-01-01

This study explores the relationship, if any, between an individual's culturally based worldviews and conceptions of nature of science. In addition, the implications of this relationship (or lack of relationship) for science teaching and learning are discussed. Participants were 54 Taiwanese prospective science teachers. Their conceptions of…

Concepts and implementations of natural language query systems

NASA Technical Reports Server (NTRS)

Dominick, Wayne D. (Editor); Liu, I-Hsiung

1984-01-01

The currently developed user language interfaces of information systems are generally intended for serious users. These interfaces commonly ignore potentially the largest user group, i.e., casual users. This project discusses the concepts and implementations of a natural query language system which satisfy the nature and information needs of casual users by allowing them to communicate with the system in the form of their native (natural) language. In addition, a framework for the development of such an interface is also introduced for the MADAM (Multics Approach to Data Access and Management) system at the University of Southwestern Louisiana.

Novel Natural Convection Heat Sink Design Concepts From First Principles

DTIC Science & Technology

2016-06-01

NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited NOVEL NATURAL ...COVERED Master’s Thesis 4. TITLE AND SUBTITLE NOVEL NATURAL CONVECTION HEAT SINK DESIGN CONCEPTS FROM FIRST PRINCIPLES 5. FUNDING NUMBERS 6...geometric structures that incorporate the principles of the stack effect to improve the heat transfer capability of a heat sink under natural convection

An Investigation of Effectiveness of Conceptual Change Text-oriented Instruction on Students' Understanding of Solution Concepts

NASA Astrophysics Data System (ADS)

Pinarbaşi; , Tacettin; Canpolat, Nurtaç; Bayrakçeken, Samih; Geban, Ömer

2006-12-01

This study investigated the effect of conceptual change text-oriented instruction over traditional instruction on students' understanding of solution concepts (e.g., dissolving, solubility, factors affecting solubility, concentrations of solutions, types of solutions, physical properties of solutions) and their attitudes towards chemistry. The sample of this study consisted of 87 undergraduate students from two classes enrolled in an introductory chemistry course. One of the classes was assigned randomly to the control group, and the other class were assigned randomly to the experimental group. During teaching the topic of solution concepts in the chemistry curriculum, a conceptual change text-oriented instruction was applied in the experimental group whereas traditional instruction was followed in the control group. The results showed that the students in the experimental group performed better with respect to solution concepts. In addition, it has been found that there was no significant difference between the attitudes of students in the experimental and control groups towards chemistry.

Elucidating concepts in drug design through taste with natural and artificial sweeteners.

PubMed

Lipchock, James M; Lipchock, Sarah V

2016-11-12

Fundamental concepts in biochemistry important for drug design often lack connection to the macroscopic world and can be difficult for students to grasp, particularly those in introductory science courses at the high school and college level. Educational research has shown that multisensory teaching facilitates learning, but teaching at the high school and college level is almost exclusively limited to the visual and auditory senses. This approach neglects the lifetime of experience our students bring to the classroom in the form of taste perception and makes our teaching less supportive of those with sensory impairment. In this article, we outline a novel guided-inquiry activity that utilizes taste perception for a series of natural and artificial sweetener solutions to introduce the concepts of substrate affinity and selectivity in the context of drug design. The findings from this study demonstrate clear gains in student knowledge, as well as an increase in enthusiasm for the fields of biochemistry and drug design. © 2016 by The International Union of Biochemistry and Molecular Biology, 44(6):550-554, 2016. © 2016 The International Union of Biochemistry and Molecular Biology.

Teaching Concepts of Natural Sciences to Foreigners through Content-Based Instruction: The Adjunct Model

ERIC Educational Resources Information Center

Satilmis, Yilmaz; Yakup, Doganay; Selim, Guvercin; Aybarsha, Islam

2015-01-01

This study investigates three models of content-based instruction in teaching concepts and terms of natural sciences in order to increase the efficiency of teaching these kinds of concepts in realization and to prove that the content-based instruction is a teaching strategy that helps students understand concepts of natural sciences. Content-based…

Natural tuning: towards a proof of concept

NASA Astrophysics Data System (ADS)

Dubovsky, Sergei; Gorbenko, Victor; Mirbabayi, Mehrdad

2013-09-01

The cosmological constant problem and the absence of new natural physics at the electroweak scale, if confirmed by the LHC, may either indicate that the nature is fine-tuned or that a refined notion of naturalness is required. We construct a family of toy UV complete quantum theories providing a proof of concept for the second possibility. Low energy physics is described by a tuned effective field theory, which exhibits relevant interactions not protected by any symmetries and separated by an arbitrary large mass gap from the new "gravitational" physics, represented by a set of irrelevant operators. Nevertheless, the only available language to describe dynamics at all energy scales does not require any fine-tuning. The interesting novel feature of this construction is that UV physics is not described by a fixed point, but rather exhibits asymptotic fragility. Observation of additional unprotected scalars at the LHC would be a smoking gun for this scenario. Natural tuning also favors TeV scale unification.

The concept of nature in Islamic science teaching

NASA Astrophysics Data System (ADS)

Zarman, Wendi

2016-02-01

Science teaching is basically value laden activities. One of the values tells that science is not related to any religion. This secular value is reflected to science teaching in many places, including religious country like Indonesia. However, we argue that in Indonesia science teaching should not be secular as in the Western country since one of the basic aim of National Education according to the Indonesian constitution Undang-Undang Dasar 1945, is to inculcate faith and god-fearing to One God Almighty. As we know, Indonesia is a Moslem country and has many Islamic schools in it too. Thus, it is important to design a science teaching framework base on Islamic teaching to fulfill the basic aim of National Education This paper discusses concept of nature, the key term in science, based on Islamic view that may used as a framework to develop Islamic science teaching. In Islam, science has a strong relation to religion since nature reflects the existence of the Creator. This concept is derived from the analysis of several verses from Qur'an as the main source of Islamic teaching. There are several principle can be derived from this analysis. Firstly, visible world is not the only world, but there is also the unseen world. Secondly, the nature is not merely matter that doesn't have any sacred value, but it is the indication or symbol of God existence and His Nature. Thirdly, The Qur'an and the nature are both Books of Allah that contain messages of Him, so they are complementary to each other

Green extraction of natural products: concept and principles.

PubMed

Chemat, Farid; Vian, Maryline Abert; Cravotto, Giancarlo

2012-01-01

The design of green and sustainable extraction methods of natural products is currently a hot research topic in the multidisciplinary area of applied chemistry, biology and technology. Herein we aimed to introduce the six principles of green-extraction, describing a multifaceted strategy to apply this concept at research and industrial level. The mainstay of this working protocol are new and innovative technologies, process intensification, agro-solvents and energy saving. The concept, principles and examples of green extraction here discussed, offer an updated glimpse of the huge technological effort that is being made and the diverse applications that are being developed.

Modeling Child–Nature Interaction in a Nature Preschool: A Proof of Concept

PubMed Central

Kahn, Peter H.; Weiss, Thea; Harrington, Kit

2018-01-01

This article provides a proof of concept for an approach to modeling child–nature interaction based on the idea of interaction patterns: characterizations of essential features of interaction between humans and nature, specified abstractly enough such that countless different instantiations of each one can occur – in more domestic or wild forms – given different types of nature, people, and purposes. The model draws from constructivist psychology, ecological psychology, and evolutionary psychology, and is grounded in observational data collected through a time-sampling methodology at a nature preschool. Through using a nature language that emphasizes ontogenetic and phylogenetic significance, seven keystone interaction patterns are described for this nature preschool: using one’s body vigorously in nature, striking wood on wood, constructing shelter, being in solitude in nature, lying on earth, cohabiting with a wild animal, and being outside in weather. These 7 interactions patterns are then brought together with 13 other patterns published elsewhere to provide a total of 20 keystone interaction patterns that begin to fill out the model, and to show its promise. Discussion focuses on what the model aims to be in terms of both product and process, on what work the model can currently do, and how to further develop the model. PMID:29896143

Modeling Child-Nature Interaction in a Nature Preschool: A Proof of Concept.

PubMed

Kahn, Peter H; Weiss, Thea; Harrington, Kit

2018-01-01

This article provides a proof of concept for an approach to modeling child-nature interaction based on the idea of interaction patterns : characterizations of essential features of interaction between humans and nature, specified abstractly enough such that countless different instantiations of each one can occur - in more domestic or wild forms - given different types of nature, people, and purposes. The model draws from constructivist psychology, ecological psychology, and evolutionary psychology, and is grounded in observational data collected through a time-sampling methodology at a nature preschool. Through using a nature language that emphasizes ontogenetic and phylogenetic significance, seven keystone interaction patterns are described for this nature preschool: using one's body vigorously in nature, striking wood on wood, constructing shelter, being in solitude in nature, lying on earth, cohabiting with a wild animal , and being outside in weather . These 7 interactions patterns are then brought together with 13 other patterns published elsewhere to provide a total of 20 keystone interaction patterns that begin to fill out the model, and to show its promise. Discussion focuses on what the model aims to be in terms of both product and process, on what work the model can currently do, and how to further develop the model.

The Concept of Ecologically Oriented Progress and Natural Resource Preservation

NASA Astrophysics Data System (ADS)

Gasanov, M. A.; Kolotov, K. A.; Demidenko, K. A.; Podgornaya, E. A.; Kadnikova, O. V.

2017-01-01

The most important issue of scientific and technological progress is considering the environment challenges of industrial development. It means that the progress must be ecologically oriented and environmentally friendly. The most adequate concept for the approach to the issue of “man - society - nature” relations is the ontology of the noosphere - the idea of a common space for human beings and nature. It presents an ideal example of an optimistic attitude towards the coordination between accelerating the scientific and technological development and natural resource saving. However, to maintain the balance between human needs and environmental processes determined by this concept, it is essential to include the lean production training into technological development of society.

Natural Conception May Be an Acceptable Option in HIV-Serodiscordant Couples in Resource Limited Settings.

PubMed

Sun, Lijun; Wang, Fang; Liu, An; Xin, Ruolei; Zhu, Yunxia; Li, Jianwei; Shao, Ying; Ye, Jiangzhu; Chen, Danqing; Li, Zaicun

2015-01-01

Many HIV serodiscordant couples have a strong desire to have their own biological children. Natural conception may be the only choice in some resource limited settings but data about natural conception is limited. Here, we reported our findings of natural conception in HIV serodiscordant couples. Between January 2008 and June 2014, we retrospectively collected data on 91 HIV serodiscordant couples presenting to Beijing Youan Hospital with childbearing desires. HIV counseling, effective ART on HIV infected partners, pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP) in negative female partners and timed intercourse were used to maximally reduce the risk of HIV transmission. Of the 91 HIV serodiscordant couples, 43 were positive in male partners and 48 were positive in female partners. There were 196 unprotected vaginal intercourses, 100 natural conception and 97 newborns. There were no cases of HIV seroconversion in uninfected sexual partners. Natural conception may be an acceptable option in HIV-serodiscordant couples in resource limited settings if HIV-positive individuals have undetectable viremia on HAART, combined with HIV counseling, PrEP, PEP and timed intercourse.

Electrodynamics; Problems and solutions

NASA Astrophysics Data System (ADS)

Ilie, Carolina C.; Schrecengost, Zachariah S.

2018-05-01

This book of problems and solutions is a natural continuation of Ilie and Schrecengost's first book Electromagnetism: Problems and Solutions. Aimed towards students who would like to work independently on more electrodynamics problems in order to deepen their understanding and problem-solving skills, this book discusses main concepts and techniques related to Maxwell's equations, conservation laws, electromagnetic waves, potentials and fields, and radiation.

Streamwise-Localized Solutions with natural 1-fold symmetry

NASA Astrophysics Data System (ADS)

Altmeyer, Sebastian; Willis, Ashley; Hof, Björn

2014-11-01

It has been proposed in recent years that turbulence is organized around unstable invariant solutions, which provide the building blocks of the chaotic dynamics. In direct numerical simulations of pipe flow we show that when imposing a minimal symmetry constraint (reflection in an axial plane only) the formation of turbulence can indeed be explained by dynamical systems concepts. The hypersurface separating laminar from turbulent motion, the edge of turbulence, is spanned by the stable manifolds of an exact invariant solution, a periodic orbit of a spatially localized structure. The turbulent states themselves (turbulent puffs in this case) are shown to arise in a bifurcation sequence from a related localized solution (the upper branch orbit). The rather complex bifurcation sequence involves secondary Hopf bifurcations, frequency locking and a period doubling cascade until eventually turbulent puffs arise. In addition we report preliminary results of the transition sequence for pipe flow without symmetry constraints.

An Advection-Diffusion Concept for Solute Transport in Heterogeneous Unconsolidated Geological Deposits

NASA Astrophysics Data System (ADS)

Gillham, R. W.; Sudicky, E. A.; Cherry, J. A.; Frind, E. O.

1984-03-01

In layered permeable deposits with flow predominately parallel to the bedding, advection causes rapid solute transport in the more permeable layers. As the solute advances more rapidly in these layers, solute mass is continually transferred to the less permeable layers as a result of molecular diffusion due to the concentration gradient between the layers. The interlayer solute transfer causes the concentration to decline along the permeable layers at the expense of increasing the concentration in the less permeable layers, which produces strongly dispersed concentration profiles in the direction of flow. The key parameters affecting the dispersive capability of the layered system are the diffusion coefficients for the less permeable layers, the thicknesses of the layers, and the hydraulic conductivity contrasts between the layers. Because interlayer solute transfer by transverse molecular diffusion is a time-dependent process, the advection-diffusion concept predicts a rate of longitudinal spreading during the development of the dispersion process that is inconsistent with the classical Fickian dispersion model. A second consequence of the solute-storage effect offered by transverse diffusion into low-permeability layers is a rate of migration of the frontal portion of a contaminant in the permeable layers that is less than the groundwater velocity. Although various lines of evidence are presented in support of the advection-diffusion concept, more work is required to determine the range of geological materials for which it is applicable and to develop mathematical expressions that will make it useful as a predictive tool for application to field cases of contaminant migration.

Science Teachers' Conceptions of Nature of Science: The Case of Bangladesh

ERIC Educational Resources Information Center

Sarkar, Md. Mahbub Alam; Gomes, Jui Judith

2010-01-01

This study explored Bangladeshi science teachers' conceptions of nature of science (NOS) with a particular focus on the nature of (a) scientific knowledge, (b) scientific inquiry and (c) scientific enterprise. The tentative, inferential, subjective and creative NOS, in addition to the myths of the scientific method and experimentation, the nature…

The Nature of Science in Science Curricula: Methods and Concepts of Analysis

ERIC Educational Resources Information Center

Ferreira, Sílvia; Morais, Ana M.

2013-01-01

The article shows methods and concepts of analysis of the nature of science in science curricula through an exemplary study made in Portugal. The study analyses the extent to which the message transmitted by the Natural Science curriculum for Portuguese middle school considers the nature of science. It is epistemologically and sociologically…

Pre-Service Physics Teachers' Conceptions of Nature of Science

ERIC Educational Resources Information Center

Buaraphan, Khajornsak

2011-01-01

Understanding of NOS (nature of science) appears as a prerequisite of a scientifically literate person. Promoting adequate understanding of NOS in pre-service physics teachers is, therefore, an important task of science educators. Before doing that, science educators must have information concerning their pre-service teachers' conceptions of NOS.…

What Is Technology? Investigating Student Conceptions about the Nature of Technology

ERIC Educational Resources Information Center

DiGironimo, Nicole

2011-01-01

The science education literature clearly shows that knowledge of the nature of technology is an educational goal; however there is a lack of research on student conceptions about the nature of technology. To address this gap in the literature, this research began with a thorough review of the literature on scientific and technological literacy,…

The risk concept and its application in natural hazard risk management in Switzerland

NASA Astrophysics Data System (ADS)

Bründl, M.; Romang, H. E.; Bischof, N.; Rheinberger, C. M.

2009-05-01

Over the last ten years, a risk-based approach to manage natural hazards - termed the risk concept - has been introduced to the management of natural hazards in Switzerland. Large natural hazard events, new political initiatives and limited financial resources have led to the development and introduction of new planning instruments and software tools that should support natural hazard engineers and planners to effectively and efficiently deal with natural hazards. Our experience with these new instruments suggests an improved integration of the risk concept into the community of natural hazard engineers and planners. Important factors for the acceptance of these new instruments are the integration of end-users during the development process, the knowledge exchange between science, developers and end-users as well as training and education courses for users. Further improvements require the maintenance of this knowledge exchange and a mindful adaptation of the instruments to case-specific circumstances.

Nature-based agricultural solutions: Scaling perennial grains across Africa.

PubMed

Peter, Brad G; Mungai, Leah M; Messina, Joseph P; Snapp, Sieglinde S

2017-11-01

Modern plant breeding tends to focus on maximizing yield, with one of the most ubiquitous implementations being shorter-duration crop varieties. It is indisputable that these breeding efforts have resulted in greater yields in ideal circumstances; however, many farmed locations across Africa suffer from one or more conditions that limit the efficacy of modern short-duration hybrids. In view of global change and increased necessity for intensification, perennial grains and long-duration varieties offer a nature-based solution for improving farm productivity and smallholder livelihoods in suboptimal agricultural areas. Specific conditions where perennial grains should be considered include locations where biophysical and social constraints reduce agricultural system efficiency, and where conditions are optimal for crop growth. Using a time-series of remotely-sensed data, we locate the marginal agricultural lands of Africa, identifying suboptimal temperature and precipitation conditions for the dominant crop, i.e., maize, as well as optimal climate conditions for two perennial grains, pigeonpea and sorghum. We propose that perennial grains offer a lower impact, sustainable nature-based solution to this subset of climatic drivers of marginality. Using spatial analytic methods and satellite-derived climate information, we demonstrate the scalability of perennial pigeonpea and sorghum across Africa. As a nature-based solution, we argue that perennial grains offer smallholder farmers of marginal lands a sustainable solution for enhancing resilience and minimizing risk in confronting global change, while mitigating social and edaphic drivers of low and variable production. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

IT Solution concept development for tracking and analyzing the labor effectiveness of employees

NASA Astrophysics Data System (ADS)

Ilin, Igor; Shirokova, Svetlana; Lepekhin, Aleksandr

2018-03-01

Labor efficiency and productivity of employees is an important aspect for the environment within any type of organization. This is particularly crucial factor for the companies, if which operations are associated with physical labor, such as construction companies. Productivity and efficiency are both very complicated concepts and a huge variety of methods and approaches to its analysis can be implemented within the organization. Despite that, it is important to choose the methods, which not only analyze the key performance indicators of employee, but take into account personal indicators, which might affect performance even more than professional skills. For this complicated analysis task it is important to build IT solution for tracking and analyzing of the labor effectiveness. The concept for designing this IT solution is proposed in the current research.

Nature and consequences of protein-protein interactions in high protein concentration solutions.

PubMed

Saluja, Atul; Kalonia, Devendra S

2008-06-24

High protein concentration solutions are becoming increasingly important in the pharmaceutical industry. The solution behavior of proteins at high concentrations can markedly differ from that predicted based on dilute solution analysis due to thermodynamic non-ideality in these solutions. The non-ideality observed in these systems is related to the protein-protein interactions (PPI). Different types of forces play a key role in determining the overall nature and extent of these PPI and their relative contributions are affected by solute and solvent properties. However, individual contributions of these forces to the solution properties of concentrated protein solutions are not fully understood. The role of PPI, driven by these intermolecular forces, in governing solution rheology and physical stability of high protein concentration solutions is discussed from the point of view of pharmaceutical product development. Investigation of protein self-association and aggregation in concentrated protein solutions is crucial for ensuring the safety and efficacy of the final product for the duration of the desired product shelf life. Understanding rheology of high concentration protein solutions is critical for addressing issues during product manufacture and administration of final formulation to the patient. To this end, analysis of solution viscoelastic character can also provide an insight into the nature of PPI affecting solution rheology.

Anthropology from a Kantian point of view: toward a cosmopolitan conception of human nature.

PubMed

Louden, Robert B

2008-12-01

Anthropology was a new field of study when Kant first began lecturing on it in 1772, and Kant himself was the first academic to teach regular courses in this area. As is well known, his own approach to anthropology is self-described as 'pragmatic', and Kant's pragmatic anthropology differs markedly from the anthropologies that other early contributors to the new discipline were advocating. In this essay I focus on a fundamental feature of Kant's anthropology that has been under-appreciated in previous discussions; namely, the particular conception of human nature that he believes anthropology, when pursued properly, leads to. I call this conception a cosmopolitan conception of human nature. In addition to establishing the central importance of this idea for Kant's project in anthropology, I also try in this essay to unravel some of its ambiguities and tensions as well as to highlight its underlying moral motives. The cosmopolitan conception of human nature that is central to Kant's anthropology is a further indication of the significance of his anthropology for ethics.

CONCEPT LEARNING AND CONCEPT TEACHING.

ERIC Educational Resources Information Center

GLASER, ROBERT

REVIEWED ARE THE PSYCHOLOGICAL STUDIES OF CONCEPT LEARNING AS THEY RELATE TO CONCEPT TEACHING. AN ANALYSIS IS MADE OF THE NATURE OF CONCEPT LEARNING AS IT IS STUDIED IN THE PSYCHOLOGIST'S LABORATORY, INCLUDING THE NATURE OF CONCEPT TASKS AS THEY APPEAR IN SUBJECT MATTER LEARNING. THE PRIMARY KINDS OF CONCEPT LEARNING SITUATIONS, INCLUDING THE…

Implementation of geotourism concept in developing natural tourist attraction at parbaba village, Toba’s caldera

NASA Astrophysics Data System (ADS)

Ginting, Nurlisa; Febriandy

2018-03-01

Toba’s Caldera is considered as a unique tourist destination as it was formed by the vulcanic eruption of Toba’s volcano, with Parbaba Village as its attraction. Geotourism, which consist of the administrator, education, uniqueness, accessibility, supporting facilities, and the increase of local people’s economy as it’s elements, is one of the concepts which can be implemented in this case. The objective of this research is to find a solution to increase natural tourist attraction in Parbaba village by making a tourist area development recommendation based on geotourism elements above. This research uses mix method, as the qualitative data will be collected by observation and interview with stakeholders, and the quantitative data will be collected by giving out 100 questionnaires to tourists and local people.The data then will be analyzed by using triangulation method. The result of this research is a concept of tourist attraction development recommendation. This research is expected to give benefits in the form of education and travel experience for tourist and also increases the economy of local people as a developer. The uniqueness element of this village is quite strong, whereas the supporting facilities are still lacking.

Technology Knowledge: High School Science Teachers' Conceptions of the Nature of Technology

ERIC Educational Resources Information Center

Waight, Noemi

2014-01-01

In-depth interviews guided by video elicitations examined 30 high school science teachers' conceptions of technology and by extension how these conceptions reflected dimensions of nature of technology. Altogether, 64% of the teachers characterized their schools and departments as aggressive-moderate adopters with generous access and support…

Developing an Instrument for Assessing Students' Concepts of the Nature of Technology

ERIC Educational Resources Information Center

Liou, Pey-Yan

2015-01-01

Background: The nature of technology has been rarely discussed despite the fact that technology plays an essential role in modern society. It is important to discuss students' concepts of the nature of technology, and further to advance their technological literacy and adaptation to modern society. There is a need to assess high school students'…

Effect of solute nature on the polyamorphic transition in glassy polyol aqueous solutions.

PubMed

Suzuki, Yoshiharu

2017-08-14

I examined the polyamorphic behavior of glassy dilute aqueous solutions of polyols (ethylene glycol, glycerol, meso-erythritol, xylitol, and D-sorbitol) under pressure at low temperatures. Although the volume change of the glassy aqueous solution varied continuously against pressure, the rate of the volume change appeared to vary discontinuously at the onset pressure of the gradual polyamorphic transition. It is thought that low-density liquid-like solvent water and high-density liquid-like solvent water coexist during the transition. Moreover, the existence of a solute induces the shift of polyamorphic transition to the lower-pressure side. The effect of a solute on the polyamorphic transition becomes larger in the order ethylene glycol, glycerol, meso-erythritol, xylitol, and D-sorbitol. Therefore, the solute can become a variable controlling the polyamorphic state of liquid water. This experimental result suggests that the metastable-equilibrium phase boundary between the low-density and the high-density amorphs for pure water is likely to be located at 0.22-0.23 GPa at about 150 K, which is slightly larger than the previously estimated pressure. Moreover, the solute-nature dependence on the polyamorphic transition seems to connect to that on the homogeneous nucleation temperature of polyol aqueous solution at ambient pressure. The region in which a low-density liquid appears coincides with the region in which the nucleus of ice Ih appears, suggesting that the formation of a low-density liquid is a precursory phenomenon of the nucleation of ice Ih.

Effect of solute nature on the polyamorphic transition in glassy polyol aqueous solutions

NASA Astrophysics Data System (ADS)

Suzuki, Yoshiharu

2017-08-01

I examined the polyamorphic behavior of glassy dilute aqueous solutions of polyols (ethylene glycol, glycerol, meso-erythritol, xylitol, and D-sorbitol) under pressure at low temperatures. Although the volume change of the glassy aqueous solution varied continuously against pressure, the rate of the volume change appeared to vary discontinuously at the onset pressure of the gradual polyamorphic transition. It is thought that low-density liquid-like solvent water and high-density liquid-like solvent water coexist during the transition. Moreover, the existence of a solute induces the shift of polyamorphic transition to the lower-pressure side. The effect of a solute on the polyamorphic transition becomes larger in the order ethylene glycol, glycerol, meso-erythritol, xylitol, and D-sorbitol. Therefore, the solute can become a variable controlling the polyamorphic state of liquid water. This experimental result suggests that the metastable-equilibrium phase boundary between the low-density and the high-density amorphs for pure water is likely to be located at 0.22-0.23 GPa at about 150 K, which is slightly larger than the previously estimated pressure. Moreover, the solute-nature dependence on the polyamorphic transition seems to connect to that on the homogeneous nucleation temperature of polyol aqueous solution at ambient pressure. The region in which a low-density liquid appears coincides with the region in which the nucleus of ice Ih appears, suggesting that the formation of a low-density liquid is a precursory phenomenon of the nucleation of ice Ih.

Undergraduate Students' Conceptions of Natural and Anthropogenic Climate Change

NASA Astrophysics Data System (ADS)

Trenbath, K. L.

2011-12-01

constructed definition removes human-causes from association with the word "climate change", which may influence their climate change understanding. Of the two higher achieving students, one emphasized anthropogenic climate change at the beginning of the semester, but later focused on natural climate change during his interviews. The other high achieving student included tangential environmental topics in her descriptions of climate change throughout the entire semester, thus conflating climate change's definition. These alternative definitions of climate change indicate that the learners constructed hybrid conceptions in order to incorporate class content with their prior ideas. These hybrid conceptions indicate that the students' understandings lie somewhere between misconceptions and conceptual change. Since the students demonstrated these hybrid conceptions at the end of class, perhaps more time is needed for the students to process the information. These case studies identify the gaps the professor should address for conceptual change to fully occur.

Multiple Solutions Approach (MSA): Conceptions and Practices of Primary School Teachers in Ghana

ERIC Educational Resources Information Center

Nabie, Michael Johnson; Raheem, Kolawole; Agbemaka, John Bijou; Sabtiwu, Rufai

2016-01-01

The study explored the curriculum guidelines and primary school teachers' conceptions and practices of the Multiple Solutions Approach (MSA) in teaching mathematics using basic qualitative research design. Informal conversation interviews (ICIs), observations, video and document analyses were used to collect data. Participants included a purposive…

Registered nurses' constructed meaning of concepts of solution and their use in clinical practice

NASA Astrophysics Data System (ADS)

Wilkes, Lesley M.; Batts, Judith E.

1991-12-01

Since the introduction of nursing into tertiary institutions in Australia in 1975, there has been increasing interest in the teaching of physical science to nurses. Various courses in physical science for nurse students have been developed. They vary in length and content but there is agreement that concepts taught should be closely related to nursing applications. The choice of relevant concepts tends to be made by individual curriculum developers. This paper reports an examination of the use of physical science concepts and their relevance from the perspective of registered nurses practising in general ward areas. Inherent in this study is the premise that for registered nurses to have ideas of the physical science underlying their practice they must have constructed meaning first for these concepts. Specific chemical concepts related to solutions are discussed in these terms.

Portable long trace profiler: Concept and solution

NASA Astrophysics Data System (ADS)

Qian, Shinan; Takacs, Peter; Sostero, Giovanni; Cocco, Daniele

2001-08-01

Since the early development of the penta-prism long trace profiler (LTP) and the in situ LTP, and following the completion of the first in situ distortion profile measurements at Sincrotrone Trieste (ELETTRA) in Italy in 1995, a concept was developed for a compact, portable LTP with the following characteristics: easily installed on synchrotron radiation beam lines, easily carried to different laboratories around the world for measurements and calibration, convenient for use in evaluating the LTP as an in-process tool in the optical workshop, and convenient for use in temporarily installation as required by other special applications. The initial design of a compact LTP optical head was made at ELETTRA in 1995. Since 1997 further efforts to reduce the optical head size and weight, and to improve measurement stability have been made at Brookhaven National Laboratory. This article introduces the following solutions and accomplishments for the portable LTP: (1) a new design for a compact and very stable optical head, (2) the use of a small detector connected to a laptop computer directly via an enhanced parallel port, and there is no extra frame grabber interface and control box, (3) a customized small mechanical slide that uses a compact motor with a connector-sized motor controller, and (4) the use of a laptop computer system. These solutions make the portable LTP able to be packed into two laptop-size cases: one for the computer and one for the rest of the system.

Advanced onboard storage concepts for natural gas-fueled automotive vehicles

NASA Technical Reports Server (NTRS)

Remick, R. J.; Elkins, R. H.; Camara, E. H.; Bulicz, T.

1984-01-01

The evaluation of several advanced concepts for storing natural gas at reduced pressure is presented. The advanced concepts include adsorption on high surface area carbon, adsorption in high porosity zeolite, storage in clathration compounds, and storage by dissolution in liquid solvents. High surface area carbons with high packing density are the best low pressure storage mediums. A simple mathematical model is used to compare adsorption storage on a state of the art carbon with compression storage. The model indicates that a vehicle using adsorption storage of natural gas at 3.6 MPa will have 36 percent of the range, on the EPA city cycle, of a vehicle operating on a compression storage system having the same physical size and a peak storage pressure of 21 MPa. Preliminary experiments and current literature suggest that the storage capacity of state of the art carbons could be improved by as much as 50 percent, and that adsorption systems having a capacity equal to compression storage at 14 MPa are possible without exceeding a maximum pressure of 3.6 MPa.

Advanced onboard storage concepts for natural gas-fueled automotive vehicles

NASA Astrophysics Data System (ADS)

Remick, R. J.; Elkins, R. H.; Camara, E. H.; Bulicz, T.

1984-06-01

The evaluation of several advanced concepts for storing natural gas at reduced pressure is presented. The advanced concepts include adsorption on high surface area carbon, adsorption in high porosity zeolite, storage in clathration compounds, and storage by dissolution in liquid solvents. High surface area carbons with high packing density are the best low pressure storage mediums. A simple mathematical model is used to compare adsorption storage on a state of the art carbon with compression storage. The model indicates that a vehicle using adsorption storage of natural gas at 3.6 MPa will have 36 percent of the range, on the EPA city cycle, of a vehicle operating on a compression storage system having the same physical size and a peak storage pressure of 21 MPa. Preliminary experiments and current literature suggest that the storage capacity of state of the art carbons could be improved by as much as 50 percent, and that adsorption systems having a capacity equal to compression storage at 14 MPa are possible without exceeding a maximum pressure of 3.6 MPa.

High School Biology Students' Transfer of the Concept of Natural Selection: A Mixed-Methods Approach

ERIC Educational Resources Information Center

Pugh, Kevin J.; Koskey, Kristin L. K.; Linnenbrink-Garcia, Lisa

2014-01-01

The concept of natural selection serves as a foundation for understanding diverse biological concepts and has broad applicability to other domains. However, we know little about students' abilities to transfer (i.e. apply to a new context or use generatively) this concept and the relation between students' conceptual understanding and transfer…

Exploring the folkbiological conception of human nature

PubMed Central

Linquist, Stefan; Machery, Edouard; Griffiths, Paul E.; Stotz, Karola

2011-01-01

Integrating the study of human diversity into the human evolutionary sciences requires substantial revision of traditional conceptions of a shared human nature. This process may be made more difficult by entrenched, ‘folkbiological’ modes of thought. Earlier work by the authors suggests that biologically naive subjects hold an implicit theory according to which some traits are expressions of an animal's inner nature while others are imposed by its environment. In this paper, we report further studies that extend and refine our account of this aspect of folkbiology. We examine biologically naive subjects' judgments about whether traits of an animal are ‘innate’, ‘in its DNA’ or ‘part of its nature’. Subjects do not understand these three descriptions to be equivalent. Both innate and in its DNA have the connotation that the trait is species-typical. This poses an obstacle to the assimilation of the biology of polymorphic and plastic traits by biologically naive audiences. Researchers themselves may not be immune to the continuing pull of folkbiological modes of thought. PMID:21199848

Turkish Primary Students' Conceptions about the Particulate Nature of Matter

ERIC Educational Resources Information Center

Ozmen, Haluk

2011-01-01

This study was conducted to determine 4th, 5th, and 6th grade primary students' conceptions about the particulate nature of matter in daily-life events. Five questions were asked of students and interviews were used to collect data. The interviews were conducted with 12 students, four students from each grade, after they finished the formal…

Docking of Natural Products against Neurodegenerative Diseases: General Concepts.

PubMed

Ribeiro, Frederico F; Mendonca Junior, Francisco J B; Ghasemi, Jahan B; Ishiki, Hamilton M; Scotti, Marcus T; Scotti, Luciana

2018-01-01

Since antiquity, humanity has used medicinal plant preparations to cure its ills, and, as research has progressed, new technologies have enabled more investigations on natural compounds which originate from plants, fungi, and marine species. The health benefits that these natural products provide have become a motive for treatment studies of various diseases. Among them, the neurodegenerative diseases like Alzheimer's and Parkinson's, a major age-related neurodegenerative disorder. Studies with natural products for neurodegenerative diseases (particularly through molecular docking) search for, and then focus on those ligands which offer effective inhibition of the enzymes monoamine oxidase and acetylcholinesterase. This review introduces the main concepts involved in docking studies with natural products: and also in our group, which has conducted a docking study of natural products isolated from Tetrapterys mucronata for inhibition of acetylcholinesterase. We observed that compounds 4 and 5 formed more interactions than the theoretical ligand, but that ligands with greater activity also interacted with residues HIS 381 and GLN 527. We have reported on our docking study performed with AChE and alkaloids isolated from the plant Tetrapterys mucronata. Our docking results corroborate the experiments conducted, and emphasize the positive contribution that these theoretical studies involving natural products bring to the fight against neurodegenerative diseases. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Experimental and CFD evidence of multiple solutions in a naturally ventilated building.

PubMed

Heiselberg, P; Li, Y; Andersen, A; Bjerre, M; Chen, Z

2004-02-01

This paper considers the existence of multiple solutions to natural ventilation of a simple one-zone building, driven by combined thermal and opposing wind forces. The present analysis is an extension of an earlier analytical study of natural ventilation in a fully mixed building, and includes the effect of thermal stratification. Both computational and experimental investigations were carried out in parallel with an analytical investigation. When flow is dominated by thermal buoyancy, it was found experimentally that there is thermal stratification. When the flow is wind-dominated, the room is fully mixed. Results from all three methods have shown that the hysteresis phenomena exist. Under certain conditions, two different stable steady-state solutions are found to exist by all three methods for the same set of parameters. As shown by both the computational fluid dynamics (CFD) and experimental results, one of the solutions can shift to another when there is a sufficient perturbation. These results have probably provided the strongest evidence so far for the conclusion that multiple states exist in natural ventilation of simple buildings. Different initial conditions in the CFD simulations led to different solutions, suggesting that caution must be taken when adopting the commonly used 'zero initialization'.

Different Conceptions of the Nature of Science among Preservice Elementary Teachers of Two Countries

ERIC Educational Resources Information Center

Park, Do-Yong; Lee, Yong Bok

2009-01-01

This study examined the differences of the nature of science (NOS) conceptions portrayed by preservice teachers in Korea (N = 42) and the United States (N = 50). We conducted a survey of preservice elementary science teachers' NOS conceptions followed by interviews in both countries to further investigate their viewpoints. The NOS domains of this…

Conceptions of the Nature of Science Held by Undergraduate Pre-Service Biology Teachers in South-West Nigeria

ERIC Educational Resources Information Center

Adedoyin, A. O.; Bello, G.

2017-01-01

This study investigated the conceptions of the nature of science held by pre-service undergraduate biology teachers in South-West, Nigeria. Specifically, the study examined the influence of their gender on their conceptions of the nature of science. The study was a descriptive research of the survey method. The population for the study comprised…

An exploration of worldview and conceptions of nature of science among science teachers at a private Christian high school

NASA Astrophysics Data System (ADS)

Kits, Kara M.

Both worldview and conceptions of nature of science (NOS) are important components in teaching and learning science. However, few empirical studies have examined the interplay between both of these components for teachers or students. Therefore, this study examines the possible relationship between worldview and conceptions of nature of science for secondary science teachers who currently teach at a Christian school. Qualitative methodologies developed a rich description of the worldview beliefs and conceptions of NOS for teachers in this study. Eight secondary science teachers employed at a private Christian school participated in the study. A Views of Nature of Science (VNOS) questionnaire and follow-up interviews elicited participants' conceptions of NOS. A semi-structured interview and Test of Preferred Explanations (TOPE) questionnaire elicited participants' worldview beliefs regarding nature and the natural world and causality. Participants communicated understandings of NOS that ranged from uninformed to informed in various aspects. In addition, while their worldview beliefs and conceptions of NOS reflected their faith beliefs, participants did not have a less informed view of NOS than other science teachers in previous studies. In fact, for several aspects of NOS, these participants articulated more informed conceptions of NOS than participants in previous studies. For these participants, faith did not appear to interfere with their ability to think scientifically in regards to their worldview beliefs regarding nature and causality. Rather, faith was incorporated into a scientifically compatible worldview regarding nature and causality that is not much different from other teachers. Other than the fact that these science teachers integrated their faith beliefs into some of their responses regarding worldview and NOS, these teachers did not appear to be much different from other science teachers. That is, there was no predictable pattern between worldview

Thai Pre-Service Science Teachers' Conceptions of the Nature of Science

ERIC Educational Resources Information Center

Buaraphan, Khajornsak; Sung-ong, Sunun

2009-01-01

The conceptions of the nature of science (NOS), particularly scientific knowledge, scientific method, scientists' work, and scientific enterprise, of 113 Thai pre-service science teachers were was captured by the Myths of Science Questionnaire (MOSQ) in the first semester of the 2008 academic year. The data was quantitatively and qualitatively…

Thai In-Service Science Teachers' Conceptions of the Nature of Science

ERIC Educational Resources Information Center

Buaraphan, Khajornsak

2009-01-01

Understanding of the Nature of Science (NOS) serves as one of the desirable characteristics of science teachers. The current study attempted to explore 101 Thai in-service science teachers' conceptions of the NOS, particularly scientific knowledge, the scientific method, scientists' work, and scientific enterprise, by using the Myths of Science…

ARPA-E: Creating Practical, Affordable Natural Gas Storage Solutions

ScienceCinema

Boysen, Dane; Loukus, Josh; Hansen, Rita

2018-05-11

Allowing people to refuel natural gas vehicles at home could revolutionize the way we power our cars and trucks. Currently, our nation faces two challenges in enabling natural gas for transportation. The first is improving the way gas tanks are built for natural gas vehicles; they need to be conformable, allowing them to fit tightly into the vehicle. The second challenge is improving the way those tanks are refueled while maintaining cost-effectiveness, safety, and reliability. This video highlights two ARPA-E project teams with innovative solutions to these challenges. REL is addressing the first challenge by developing a low-cost, conformable natural gas tank with an interconnected core structure. Oregon State University and OnBoard Dynamics are addressing the second challenge by developing a self-refueling natural gas vehicle that integrates a compressor into its engine-using one of the engine's cylinders to compress gas eliminates the need for an expensive at-home refueling system. These two distinct technologies from ARPA-E's MOVE program illustrate how the Agency takes a multi-pronged approach to problem solving and innovation.

Education in the imbalance of Nature

NASA Astrophysics Data System (ADS)

Shlafman, L. M.; Kontar, V. A.

2013-12-01

There are two concepts understanding of the real Nature: balanced and imbalanced. The traditional balanced concept understanding of Nature was originated in prehistoric times to calm the frightened souls of prehistoric man and manage groups of people. The balanced concept presupposes that Nature is isotropic, balanced, etc. The balanced concept of understanding of Nature gradually has moved to science and technology. The balanced concept of understanding of Nature is dominating from the prehistoric time up to today. But always parallel and opposite was exists the concept imbalanced understanding of Nature, which presupposes that Nature is anisotropy, imbalanced, etc. The balanced concept is much simpler than Imbalanced. The balanced concept has given mankind a lot of rough description of Nature which helped to solve a lot of practical problems but with sufficient accuracy, i.e. approximately, but not with an absolute precision. While people were few, and a lot of resources, person could take from Nature only what Nature gave willingly. During this period, people feared and respected Nature and Nature was able easily compensate the activity of people. The high accuracy of the description of Nature was not needed when resources were plentiful and people were few. But now the situation is completely different. The population has become a very large and growing. Traditional resources are almost run out and the lack of resources escalates. People are not afraid of Nature and bravely try to take by force what Nature does not give voluntarily. People invaded into imbalance Nature, and Nature can no longer compensate activity of people. The era of global change is started, including those that man provokes. In the conditions of global changes is insufficiently of the approximate solutions of the traditional balanced concept. The balanced concept is exhausted, and increasingly misleads people. The balanced concept cannot solve the problems that arise in the global change

Turkish Grade 10 Students' and Science Teachers' Conceptions of Nature of Science: A National Study

ERIC Educational Resources Information Center

Dogan, Nihal; Abd-El-Khalick, Fouad

2008-01-01

This study aimed to assess grade 10 Turkish students' and science teachers' conceptions of nature of science (NOS) and whether these conceptions were related to selected variables. These variables included participants' gender, geographical region, and the socioeconomic status (SES) of their city and region; teacher disciplinary background, years…

Timing of conception and the risk of spontaneous abortion among pregnancies occurring during the use of natural family planning.

PubMed

Gray, R H; Simpson, J L; Kambic, R T; Queenan, J T; Mena, P; Perez, A; Barbato, M

1995-05-01

Our purpose was to ascertain the effects of timing of conception on the risk of spontaneous abortion. To assess these effects, women who conceived while using natural family planning were identified in five centers worldwide between 1987 and 1993. Timing of conception was determined from 868 natural family planning charts that recorded day of intercourse and indices of ovulation (cervical mucus peak obtained according to the ovulation method and/or basal body temperature). Conceptions on days - 1 or 0 with respect to the natural family planning estimated day of ovulation were considered to be "optimally timed," and all other conceptions were considered as "non-optimally timed." The rate of spontaneous abortions per 100 pregnancies was examined in relation to timing of conception, ages, reproductive history, and other covariates with bivariate and multivariate statistical methods. There were 88 spontaneous abortions among 868 pregnancies (10.1%). The spontaneous abortion rate was similar for 361 optimally timed conceptions (9.1%) and 507 non-optimally timed conceptions (10.9%). However, among 171 women who had experienced a spontaneous abortion in a prior pregnancy, the rate of spontaneous abortion in the index pregnancy was significantly higher with non-optimally timed conceptions (22.6%) as compared with optimally timed conceptions (7.3%). This association was not observed among 697 women with no history of pregnancy loss. The adjusted relative risk of spontaneous abortion among women with non-optimally timed conceptions and a history of pregnancy loss was 2.35 (95% confidence intervals 1.42 to 3.89). The excess risk of spontaneous abortion was observed with both preovulatory and postovulatory conceptions. Overall, there is no excess risk of spontaneous abortion among the pregnancies conceived during natural family planning use. However, among women with a history of pregnancy loss, there is an increased risk of spontaneous abortion associated with preovulatory or

Biological Principles and Threshold Concepts for Understanding Natural Selection. Implications for Developing Visualizations as a Pedagogic Tool

NASA Astrophysics Data System (ADS)

Tibell, Lena A. E.; Harms, Ute

2017-11-01

Modern evolutionary theory is both a central theory and an integrative framework of the life sciences. This is reflected in the common references to evolution in modern science education curricula and contexts. In fact, evolution is a core idea that is supposed to support biology learning by facilitating the organization of relevant knowledge. In addition, evolution can function as a pivotal link between concepts and highlight similarities in the complexity of biological concepts. However, empirical studies in many countries have for decades identified deficiencies in students' scientific understanding of evolution mainly focusing on natural selection. Clearly, there are major obstacles to learning natural selection, and we argue that to overcome them, it is essential to address explicitly the general abstract concepts that underlie the biological processes, e.g., randomness or probability. Hence, we propose a two-dimensional framework for analyzing and structuring teaching of natural selection. The first—purely biological—dimension embraces the three main principles variation, heredity, and selection structured in nine key concepts that form the core idea of natural selection. The second dimension encompasses four so-called thresholds, i.e., general abstract and/or non-perceptual concepts: randomness, probability, spatial scales, and temporal scales. We claim that both of these dimensions must be continuously considered, in tandem, when teaching evolution in order to allow development of a meaningful understanding of the process. Further, we suggest that making the thresholds tangible with the aid of appropriate kinds of visualizations will facilitate grasping of the threshold concepts, and thus, help learners to overcome the difficulties in understanding the central theory of life.

Investigating the Relationship between Teachers' Nature of Science Conceptions and Their Practice of Inquiry Science

ERIC Educational Resources Information Center

Atar, Hakan Yavuz; Gallard, Alejandro

2011-01-01

In addition to recommending inquiry as the primary approach to teaching science, developers of recent reform efforts in science education have also strongly suggested that teachers develop a sound understanding of the nature of science. Most studies on teachers' NOS conceptions and inquiry beliefs investigated these concepts of teachers' NOS…

The Electromagnetic Conception of Nature at the Root of the Special and General Relativity Theories and its Revolutionary Meaning

NASA Astrophysics Data System (ADS)

Giannetto, Enrico R. A.

2009-06-01

The revolution in XX century physics, induced by relativity theories, had its roots within the electromagnetic conception of Nature. It was developed through a tradition related to Brunian and Leibnizian physics, to the German Naturphilosophie and English XIXth physics. The electromagnetic conception of Nature was in some way realized by the relativistic dynamics of Poincaré of 1905. Einstein, on the contrary, after some years, linked relativistic dynamics to a semi-mechanist conception of Nature. He developed general relativity theory on the same ground, but Hilbert formulated it starting from the electromagnetic conception of Nature. Here, a comparison between these two conceptions is proposed in order to understand the conceptual foundations of special relativity within the context of the changing world views. The whole history of physics as well as history of science can be considered as a conflict among different worldviews. Every theory, as well as every different formulation of a theory implies a different worldview: a particular image of Nature implies a particular image of God (atheism too has a particular image of God) as well as of mankind and of their relationship. Thus, it is very relevant for scientific education to point out which image of Nature belongs to a particular formulation of a theory, which image comes to dominate and for which ideological reason.

Solutions for characterising natural landscapes in New Zealand using geographical information systems.

PubMed

Brabyn, Lars

2005-07-01

This paper explores solutions for characterising naturalness in relation to visual landscapes using Geographical Information System (GIS). It is argued that planners need to identify natural landscapes and monitor changes in their extent. Just like the indices that have been developed to describe the state of the economy, indices need to be developed that monitor the state of natural landscapes. The complications in characterising natural landscapes are outlined but it is argued that there is a need to develop definitions of natural landscapes that can be operationalised with a GIS. This will have the advantages of the efficiency of the technology and that the definition will be explicit and the implementation will be independent of the operator. Several GIS solutions are provided and these are an analysis of landcover, a density analysis of roads and utilities, and an analysis of property sizes. The analysis of property sizes is sensitive to many human modifications of the landscape because many developments begin with the subdivision of properties. However, it is argued in this paper that no one definition will suffice and that all three methods provide different, yet important, insights into natural landscape character. An aggregate classification of naturalness based on the majority value of the indices is demonstrated as well as a range of techniques for expressing the uncertainty of the aggregate classification.

Integrating adaptive management and ecosystem services concepts to improve natural resource management: Challenges and opportunities

USGS Publications Warehouse

Epanchin-Niell, Rebecca S.; Boyd, James W.; Macauley, Molly K.; Scarlett, Lynn; Shapiro, Carl D.; Williams, Byron K.

2018-05-07

Executive Summary—OverviewNatural resource managers must make decisions that affect broad-scale ecosystem processes involving large spatial areas, complex biophysical interactions, numerous competing stakeholder interests, and highly uncertain outcomes. Natural and social science information and analyses are widely recognized as important for informing effective management. Chief among the systematic approaches for improving the integration of science into natural resource management are two emergent science concepts, adaptive management and ecosystem services. Adaptive management (also referred to as “adaptive decision making”) is a deliberate process of learning by doing that focuses on reducing uncertainties about management outcomes and system responses to improve management over time. Ecosystem services is a conceptual framework that refers to the attributes and outputs of ecosystems (and their components and functions) that have value for humans.This report explores how ecosystem services can be moved from concept into practice through connection to a decision framework—adaptive management—that accounts for inherent uncertainties. Simultaneously, the report examines the value of incorporating ecosystem services framing and concepts into adaptive management efforts.Adaptive management and ecosystem services analyses have not typically been used jointly in decision making. However, as frameworks, they have a natural—but to date underexplored—affinity. Both are policy and decision oriented in that they attempt to represent the consequences of resource management choices on outcomes of interest to stakeholders. Both adaptive management and ecosystem services analysis take an empirical approach to the analysis of ecological systems. This systems orientation is a byproduct of the fact that natural resource actions affect ecosystems—and corresponding societal outcomes—often across large geographic scales. Moreover, because both frameworks focus on

Evaluation of strategies for nature-based solutions to drought: a decision support model at the national scale

NASA Astrophysics Data System (ADS)

Simpson, Mike; Ives, Matthew; Hall, Jim

2016-04-01

There is an increasing body of evidence in support of the use of nature based solutions as a strategy to mitigate drought. Restored or constructed wetlands, grasslands and in some cases forests have been used with success in numerous case studies. Such solutions remain underused in the UK, where they are not considered as part of long-term plans for supply by water companies. An important step is the translation of knowledge on the benefits of nature based solutions at the upland/catchment scale into a model of the impact of these solutions on national water resource planning in terms of financial costs, carbon benefits and robustness to drought. Our project, 'A National Scale Model of Green Infrastructure for Water Resources', addresses this issue through development of a model that can show the costs and benefits associated with a broad roll-out of nature based solutions for water supply. We have developed generalised models of both the hydrological effects of various classes and implementations of nature-based approaches and their economic impacts in terms of construction costs, running costs, time to maturity, land use and carbon benefits. Our next step will be to compare this work with our recent evaluation of conventional water infrastructure, allowing a case to be made in financial terms and in terms of security of water supply. By demonstrating the benefits of nature based solutions under multiple possible climate and population scenarios we aim to demonstrate the potential value of using nature based solutions as a component of future long-term water resource plans. Strategies for decision making regarding the selection of nature based and conventional approaches, developed through discussion with government and industry, will be applied to the final model. Our focus is on keeping our work relevant to the requirements of decision-makers involved in conventional water planning. We propose to present the outcomes of our model for the evaluation of nature

[Plinius and Greek physicians in Rome: the concept of nature and medical critique in Naturalis Historia].

PubMed

Hahn, J

1991-01-01

Pliny's historical outline of the development of medicine, in Natural History 29.1-27, is our primary source concerning the reception of scientific medicine at Rome during the later Republic and early Empire. Here, as elsewhere, Pliny handles Greek doctors and their medical practices with vehement disapproval. But this attitude, at first glance anti-Hellene, traditionalistic, and critical of his coevals, arises from more deeply rooted notions: a specific conception of nature which can be shown to be the basis of Pliny's critique of medicine and his own times. Reconstruction of this "Plinean" conception reveals a view of nature marked by Stoic terminology and categories, though in fact derivate from various sources, idiosyncratic and characterized by a genuine love of and respect for nature and her creations. True comprehension of the lessons offered by nature, resulting in concrete mores of behaviour and moral categories, as opposed to theory and speculation, is the proper modus operandi for Pliny. And thus, with regard to the human process of self-discovery in the natural world, medicine plays a decisive role--for providential nature displays herself most clearly in the production of healing substances. Pliny notes among the proponents of scientific medicine, a general disregard for nature and her rules, while he finds just the opposite in traditional medicine. His own accomplishment resides not only in the safeguarding of numberless recipies from the world of folk medicine, but also in the facts that he under-pins these traditional methods of healing, and their basic principles, with a specific conception of nature, and that he marks out an exceptionally important place for traditional methods of healing in the canon of general knowledge.

The Electromagnetic Conception of Nature at the Root of the Special and General Relativity Theories and Its Revolutionary Meaning

ERIC Educational Resources Information Center

Giannetto, Enrico R. A.

2009-01-01

The revolution in XX century physics, induced by relativity theories, had its roots within the electromagnetic conception of Nature. It was developed through a tradition related to Brunian and Leibnizian physics, to the German "Naturphilosophie" and English XIXth physics. The electromagnetic conception of Nature was in some way realized by the…

Making Learning Last: Teachers' Long-Term Retention of Improved Nature of Science Conceptions and Instructional Rationales

ERIC Educational Resources Information Center

Mulvey, Bridget K.; Bell, Randy L.

2017-01-01

Despite successful attempts to improve learners' nature of science (NOS) conceptions through explicit, reflective approaches, retention of improved conceptions is rarely addressed in research. The issue of context for NOS instruction has implications for this retention. Whether to contextualise has been the question occupying science educators'…

A Study of Taiwanese Children's Conceptions of and Relation to Nature: Curricular and Policy Implications

ERIC Educational Resources Information Center

Dai, Amy Hsin-I

2011-01-01

The present study investigated children's conceptions of and relations to nature. Understanding the factors that influence them was the goal. The study used the Contextual Model of Learning as the theoretical framework to structure the research questions and data analysis to understand children's nature learning in the personal, sociocultural, and…

Conceptions of the nature of science and worldviews of preservice elementary science teachers in Taiwan

NASA Astrophysics Data System (ADS)

Liu, Shiang-Yao

This exploratory investigation aimed to identify preservice science teachers' conceptions of the nature of science (NOS), and worldviews that represent their culturally dependent beliefs about the world, in the context of Taiwan. The interrelationships between the responses elicited from both the assessments of NOS understandings and worldviews were examined. Participants included 54 third-year students enrolled in the departments of science education and mathematics education at a teachers college. Their worldviews and NOS conceptions were tabulated by two questionnaires and 14 of them were purposefully selected to participate follow-up interviews. The worldview questionnaire contained five open-ended items, of which each examines one of the worldview domains in Kearney's model (1984). The NOS questionnaire consisting of nine open-ended questions was developed, specifically addressing cultural characteristics, to assess participants' views on the development of scientific knowledge. An anthropocentric-moderate continuum emerged to describe participants' views of the humanity's relationship with Nature. It was found that participants with informed NOS conceptions were more likely to emphasize harmony with Nature, recognize the limitations of scientific knowledge, and accept the idea that science involves subjective and cultural components. On the other hand, participants who provided a pragmatic perspective of Nature seemed to possess narrow views about the scientific enterprises by describing science as close to technology and as a materialistic benefit. Authoritarianism was also a noticeable cultural trait hindering some participants from reflecting on the values inherent to the development of scientific knowledge, and also prohibiting them from searching empirical evidence to solve problems. It was found that there were differences between science education and mathematics education majors in their worldviews and NOS understandings. The results in this study not

Exploring South African High School Teachers' Conceptions of the Nature of Scientific Inquiry: A Case Study

ERIC Educational Resources Information Center

Dudu, Washington T.

2014-01-01

The paper explores conceptions of the nature of scientific inquiry (NOSI) held by five teachers who were purposively and conveniently sampled. Teachers' conceptions of the NOSI were determined using a Probes questionnaire. To confirm teachers' responses, a semi-structured interview was conducted with each teacher. The Probes questionnaire was…

Natural conception rates in couples with unexplained or mild male subfertility scheduled for fertility treatment: a secondary analysis of a randomized controlled trial.

PubMed

van Eekelen, R; Tjon-Kon-Fat, R I; Bossuyt, P M M; van Geloven, N; Eijkemans, M J C; Bensdorp, A J; van der Veen, F; Mol, B W; van Wely, M

2018-05-01

What is the natural conception rate over the course of 12 months in couples with unexplained or mild male subfertility who are scheduled for fertility treatment and have a predicted unfavourable prognosis for natural conception? The natural conception rate over the course of 12 months in couples who were allocated to treatment was estimated to be 24.5% (95% CI: 20-29%). After starting treatment, couples often perceive unsuccessful cycles as evidence of definitive failure even though they are still able to conceive naturally in between and after treatment. The magnitude of the natural conception rate for couples who chose to commence treatment is unknown, as is whether the calculated prognosis before commencing treatment is still applicable. We performed a secondary analysis of a randomized controlled trial including couples with unexplained or mild male subfertility and an unfavourable prognosis for natural conception. Couples were allocated to either three cycles IVF with single embryo transfer (SET), six cycles of IVF in a modified natural cycle (MNC) or six cycles of IUI with controlled ovarian hyperstimulation (IUI-COH). The detailed data collection in this trial allowed us to study the conception rates in periods that couples were not receiving treatment. We split the dataset into periods during which couples were treated and periods during which they were not treated. Couples could conceive naturally in the periods before, in between and after treatment cycles. The outcome was ongoing pregnancy, thus natural conception rate refers to natural conception leading to ongoing pregnancy. We performed a Cox proportional hazards analysis with female age, duration of subfertility and a time-varying covariate with four categories: IVF-SET, IVF-MNC, IUI-COH and no treatment. We used this Cox model to estimate the natural conception rate over 12 months of no treatment. Out of 602 included couples, there were 342 ongoing pregnancies, of which 77 (23%) resulted from

NOBLE - Flexible concept recognition for large-scale biomedical natural language processing.

PubMed

Tseytlin, Eugene; Mitchell, Kevin; Legowski, Elizabeth; Corrigan, Julia; Chavan, Girish; Jacobson, Rebecca S

2016-01-14

Natural language processing (NLP) applications are increasingly important in biomedical data analysis, knowledge engineering, and decision support. Concept recognition is an important component task for NLP pipelines, and can be either general-purpose or domain-specific. We describe a novel, flexible, and general-purpose concept recognition component for NLP pipelines, and compare its speed and accuracy against five commonly used alternatives on both a biological and clinical corpus. NOBLE Coder implements a general algorithm for matching terms to concepts from an arbitrary vocabulary set. The system's matching options can be configured individually or in combination to yield specific system behavior for a variety of NLP tasks. The software is open source, freely available, and easily integrated into UIMA or GATE. We benchmarked speed and accuracy of the system against the CRAFT and ShARe corpora as reference standards and compared it to MMTx, MGrep, Concept Mapper, cTAKES Dictionary Lookup Annotator, and cTAKES Fast Dictionary Lookup Annotator. We describe key advantages of the NOBLE Coder system and associated tools, including its greedy algorithm, configurable matching strategies, and multiple terminology input formats. These features provide unique functionality when compared with existing alternatives, including state-of-the-art systems. On two benchmarking tasks, NOBLE's performance exceeded commonly used alternatives, performing almost as well as the most advanced systems. Error analysis revealed differences in error profiles among systems. NOBLE Coder is comparable to other widely used concept recognition systems in terms of accuracy and speed. Advantages of NOBLE Coder include its interactive terminology builder tool, ease of configuration, and adaptability to various domains and tasks. NOBLE provides a term-to-concept matching system suitable for general concept recognition in biomedical NLP pipelines.

Solution dynamics of synthetic and natural polyelectrolytes

NASA Astrophysics Data System (ADS)

Krause, Wendy E.

Polyelectrolytes are abundant in nature and essential to life, and used extensively in industry. This work discussed two polyelectrolytes: sodium poly(2-acrylamido-2-methylpropanesulfonate) (NaPAMS), synthetic polyelectrolyte, and sodium hyaluronate (NaHA), a glycosaminoglycan. Rheological data of NaPAMS solutions of variable chain length and concentration were reported. A strong dependence of viscosity eta on chain length: eta ˜ M2.4 was found. The comparison of the rheological data with two proposed scaling theories (Dobrynin 1995, Witten 1987) forces the conclusion that neither theory is correct. A possible interpretation of the viscosity data falling between the predictions of the two scaling theories is that some chain rigidity may persist beyond the correlation length. A sample model for the conductivity of semidilute polyelectrolytes with no added salt was presented. The model correctly describes the logarithmic decrease of specific conductance observed for many polyelectrolytes at low concentration (below ca. 10-2M), and is in good agreement with data from NaPAMS solutions. NaHA in phosphate buffered saline behaves as a typical polyelectrolyte in the high-salt limit, as Newtonian viscosities are observed over a wide range of shear rates. There is no evidence of intermolecular hydrogen bonding causing gel formation in NaHA solutions without protein present. The viscosity of 3 mg/mL NaHA was measured in the presence of the selected anti-inflammatory agents. Of the seven additives investigated only (D)-penicillamine significantly altered the rheology of HA. (D)-Penicillamine dramatically reduced the viscosity of HA, probably by disrupting intramolecular hydrogen bonding. The plasma proteins albumin and gamma-globulins bind to HA in solution to form a weak reversible gel. The rheology and osmotic pressure of the simple model for synovial fluid, consisting of 3mg/mL NaHA, 11 mg/mL albumin, and 7 mg/mL gamma-globulins in phosphate buffered saline, were studied

Reflections on the nature of the concepts of field in physics

NASA Astrophysics Data System (ADS)

Pombo, C.

2012-12-01

This paper is a short introduction on the analysis of the concepts of field in physics, showing their different natures. It comprises a study on the development of observers based on observational realism, a physical epistemology in development, on the basis of analytical psychology. This epistemology incorporates and justify the proposition of R. Carnap, of separating observational and theoretical domains of a theory, and gives a criterion for this separation. The basis of three theories are discussed, where concepts of field emerge. We discuss the different origins and meanings of these fields, from an epistemological point of view, in their respective theories. The aim of this paper is to form a basis of discussion to be applied in the analysis of other theories where concepts of field are present, to reach a better understanding of the contemporary programs of unification. We would like to clarify if these programs are intended for unification of fields as elements of the physical reality, fields as explanations for the observations, unification of their theories, or other possible cases.

Pluralities of place: A user's guide to place concepts, theories, and philosophies in natural resource management

Treesearch

Daniel R. Williams

2008-01-01

Place ideas are capturing increasing attention in recreation and natural resource management. But there are important and sometimes incompatible differences among the various concepts. In this paper I describe some of the reasons for the growing interest in place concepts and distinguish between four basic approaches: attitude, meaning, ethical, and political. My aim...

For Want of a Better Word: Unlocking Threshold Concepts in Natural Sciences with a Key from the Humanities?

ERIC Educational Resources Information Center

Green, David A.; Loertscher, Jennifer; Minderhout, Vicky; Lewis, Jennifer E.

2017-01-01

The process of identifying threshold concepts invites experts to reflect on their discipline in a new way with the ultimate goal of improving learning and teaching. During a workshop to identify threshold concepts in biochemistry, we asked a group of natural scientists to explore "signification," a threshold concept from the humanities,…

Solution of heat removal from nuclear reactors by natural convection

NASA Astrophysics Data System (ADS)

Zitek, Pavel; Valenta, Vaclav

2014-03-01

This paper summarizes the basis for the solution of heat removal by natural convection from both conventional nuclear reactors and reactors with fuel flowing coolant (such as reactors with molten fluoride salts MSR).The possibility of intensification of heat removal through gas lift is focused on. It might be used in an MSR (Molten Salt Reactor) for cleaning the salt mixture of degassed fission products and therefore eliminating problems with iodine pitting. Heat removal by natural convection and its intensification increases significantly the safety of nuclear reactors. Simultaneously the heat removal also solves problems with lifetime of pumps in the primary circuit of high-temperature reactors.

Beyond Exemplars and Prototypes as Memory Representations of Natural Concepts: A Clustering Approach

ERIC Educational Resources Information Center

Verbeemen, Timothy; Vanpaemel, Wolf; Pattyn, Sven; Storms, Gert; Verguts, Tom

2007-01-01

Categorization in well-known natural concepts is studied using a special version of the Varying Abstraction Framework (Vanpaemel, W., & Storms, G. (2006). A varying abstraction framework for categorization. Manuscript submitted for publication; Vanpaemel, W., Storms, G., & Ons, B. (2005). A varying abstraction model for categorization. In B. Bara,…

Representations of Fundamental Chemistry Concepts in Relation to the Particulate Nature of Matter

ERIC Educational Resources Information Center

Kirbulut, Zubeyde Demet; Beeth, Michael Edward

2013-01-01

This study investigated high school students' understanding of fundamental chemistry concepts - states of matter, melting, evaporation, condensation, boiling, and vapor pressure, in relation to their understanding of the particulate nature of matter. A sample of six students (four females and two males) enrolled in a second year chemistry course…

Test-Enhanced Learning of Natural Concepts: Effects on Recognition Memory, Classification, and Metacognition

ERIC Educational Resources Information Center

Jacoby, Larry L.; Wahlheim, Christopher N.; Coane, Jennifer H.

2010-01-01

Three experiments examined testing effects on learning of natural concepts and metacognitive assessments of such learning. Results revealed that testing enhanced recognition memory and classification accuracy for studied and novel exemplars of bird families on immediate and delayed tests. These effects depended on the balance of study and test…

Investigation of anti-Müllerian hormone concentrations in relation to natural conception rate and time to pregnancy.

PubMed

Korsholm, Anne-Sofie; Petersen, Kathrine Birch; Bentzen, Janne Gasseholm; Hilsted, Linda Maria; Andersen, Anders Nyboe; Hvidman, Helene Westring

2018-05-01

The objectives of this study were to investigate whether anti-Müllerian hormone (AMH) concentrations can predict pregnancy rates and time to pregnancy (TTP) in women attempting to conceive naturally/having an unplanned conception, and whether there is a lower AMH threshold compatible with natural conception. This prospective cohort study included 260 women aged 25-42 years in two subcohorts: (A) healthcare workers at Rigshospitalet (2008-2010), and (B) women consulting the Fertility Assessment and Counselling Clinic (2011-2014), Rigshospitalet, Denmark. Pregnancy rates and TTP at 2-year follow-up were stratified into AMH groups: low: < 9.5 pmol/l, intermediate: 9.5-33 pmol/l, high: > 33 pmol/l. Pregnancy rates increased with increasing AMH: 60.1% (low) versus 70.0% (intermediate) versus 78.3% (high) (P = 0.03). The highest pregnancy rate (84.1%) was seen in regular cycling women with high AMH. TTP was reduced in women with high AMH compared with intermediate or low AMH (stepwise trend test P = 0.01). Natural conceptions were observed with AMH concentrations down to 1.2 pmol/l. In conclusion, high AMH, especially in ovulatory women, was associated with higher pregnancy rates. Nonetheless, TTP reflected a large variation in fecundity within similar AMH concentrations and natural conceptions occurred with AMH down to 1.2 pmol/l. Copyright © 2018 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Confronting, Representing, and Believing Counterintuitive Concepts: Navigating the Natural and the Supernatural.

PubMed

Lane, Jonathan D; Harris, Paul L

2014-03-01

Recent research shows that even preschoolers are skeptical; they frequently reject claims from other people when the claims conflict with their own perceptions and concepts. Yet, despite their skepticism, both children and adults come to believe in a variety of phenomena that defy their first-hand perceptions and intuitive conceptions of the world. In this review, we explore how children and adults acquire such concepts. We describe how a similar developmental process underlies mental representation of both the natural and the supernatural world, and we detail this process for two prominent supernatural counterintuitive ideas-God and the afterlife. In doing so, we highlight the fact that conceptual development does not always move in the direction of greater empirical truth, as described within naturalistic domains. We consider factors that likely help overcome skepticism and, in doing so, promote belief in counterintuitive phenomena. These factors include qualities of the learners, aspects of the context, qualities of the informants, and qualities of the information. © The Author(s) 2014.

Confronting, Representing, and Believing Counterintuitive Concepts: Navigating the Natural and the Supernatural

PubMed Central

Lane, Jonathan D.; Harris, Paul. L.

2014-01-01

Recent research shows that even preschoolers are skeptical; they frequently reject claims from other people when the claims conflict with their own perceptions and concepts. Yet, despite their skepticism, both children and adults come to believe in a variety of phenomena that defy their first-hand perceptions and intuitive conceptions of the world. In this review, we explore how children and adults acquire such concepts. We describe how a similar developmental process underlies mental representation of both the natural and the supernatural world, and we detail this process for two prominent supernatural counterintuitive ideas—God and the afterlife. In doing so, we highlight the fact that conceptual development does not always move in the direction of greater empirical truth, as described within naturalistic domains. We consider factors that likely help overcome skepticism, and in doing so promote belief in counterintuitive phenomena. These factors include qualities of the learners, aspects of the context, qualities of the informants, and qualities of the information. PMID:24683418

Health-Related Quality of Life and Primi-Gravid: A Comparative Study of Natural Conception and Conception by Assisted Reproduction Technologies (ARTs)

PubMed Central

Ahmadi, Seyed Ebrahim; Montazeri, Ali; Mozafari, Ramin; Azari, Afsaneh; Nateghi, Mohammad Reza; Ashrafi, Mahnaz

2014-01-01

Background Childbearing for the first time is a unique experience. Quality of life is an important indicator in health studies. This study aimed to assess the quality of life of women who were conceived by ARTs and had successful childbirth for the first time and to compare it with quality of life in women who become pregnant naturally and similarly had successful childbirth for the first time. Materials and Methods This was a cross sectional comparative study. The accessible sam- ple was recruited from patients attending an infertility clinic and two obstetric and gynecology clinics in Tehran, Iran, during March 2010 to March 2011. In all 276 patients were approached. Of these, 162 women (76 women in natural conception group and 86 women in assisted reproduction technologies group) who met the inclusion criteria were entered into the study. Quality of life was assessed using the 36-item Short Form Health Survey (SF-36). Women completed the questionnaire at two time points: i. last trimester and ii. first month after delivery. Comparison was made between two groups using Mann-Whitney U test and paired samples t test. Results Comparing the SF-36 scores between women in natural conception group and ARTs group before childbirth, it was found that natural group had better condition on physical functioning, role limitation due to physical problems, bodily pain and social functioning, while the ARTs group reported better status on general health, vitality, role limitation due to emotional problems, and mental health. However, after childbirth, the ARTs group reported a better condition almost on all measures, except for physical functioning. Comparing differences in obtained scores between two groups before and after childbirth, the results showed that improvements in health related quality of life measures for the ARTs group were greater in all measures, expect for general health. Conclusion The findings from this study suggest that health-related quality of life was

Representations of Fundamental Chemistry Concepts in Relation to the Particulate Nature of Matter

ERIC Educational Resources Information Center

Kirbulut, Zübeyde Demet; Beeth, Michael Edward

2013-01-01

This study investigated high school students' understanding of fundamental chemistry concepts--states of matter, melting, evaporation, condensation, boiling, and vapor pressure, in relation to their understanding of the particulate nature of matter. A sample of six students (four females and two males) enrolled in a second year chemistry course at…

Professional Development of Elementary and Science Teachers in a Summer Science Camp: Changing Nature of Science Conceptions

ERIC Educational Resources Information Center

Karaman, Ayhan

2016-01-01

Many countries all over the world have recently integrated nature of science (NOS) concepts into their science education standards. Providing professional support to teachers about NOS concepts is crucially important for successful implementation of the standards. For this purpose, a summer science camp was offered to elementary and science…

The Online Dissemination of Nature-Health Concepts: Lessons from Sentiment Analysis of Social Media Relating to "Nature-Deficit Disorder".

PubMed

Palomino, Marco; Taylor, Tim; Göker, Ayse; Isaacs, John; Warber, Sara

2016-01-19

Evidence continues to grow supporting the idea that restorative environments, green exercise, and nature-based activities positively impact human health. Nature-deficit disorder, a journalistic term proposed to describe the ill effects of people's alienation from nature, is not yet formally recognized as a medical diagnosis. However, over the past decade, the phrase has been enthusiastically taken up by some segments of the lay public. Social media, such as Twitter, with its opportunities to gather "big data" related to public opinions, offers a medium for exploring the discourse and dissemination around nature-deficit disorder and other nature-health concepts. In this paper, we report our experience of collecting more than 175,000 tweets, applying sentiment analysis to measure positive, neutral or negative feelings, and preliminarily mapping the impact on dissemination. Sentiment analysis is currently used to investigate the repercussions of events in social networks, scrutinize opinions about products and services, and understand various aspects of the communication in Web-based communities. Based on a comparison of nature-deficit-disorder "hashtags" and more generic nature hashtags, we make recommendations for the better dissemination of public health messages through changes to the framing of messages. We show the potential of Twitter to aid in better understanding the impact of the natural environment on human health and wellbeing.

Solution of naturally-ocurring glasses in the geological environment

NASA Technical Reports Server (NTRS)

Glass, B. P.

1982-01-01

As part of a study to investigate the feasibility of putting nuclear wastes in glass containers and burying them on land or dumping them in the ocean, the amount of solution experience by naturally occurring glasses from two land sites and thirty-four deep sea sites was studied. The glasses are microtektites from three strewn fields and from the Zhamanshin impact crater. The microtektites range in age from 0.7 to 35 m.y. and have a wide range in composition. The weight percent SiO2, for example, ranges from 44.8 to 81.7. Although several criteria for determining the amount of solution were considered, most of the conclusions are based on two criteria: (1) width of cracks, and (2) elevation of silica rich inclusions above the adjacent microtektite surface. All the measurements were made on scanning electron microscope photomicrographs of the microtektites.

Constructing Concept Schemes From Astronomical Telegrams Via Natural Language Clustering

NASA Astrophysics Data System (ADS)

Graham, Matthew; Zhang, M.; Djorgovski, S. G.; Donalek, C.; Drake, A. J.; Mahabal, A.

2012-01-01

The rapidly emerging field of time domain astronomy is one of the most exciting and vibrant new research frontiers, ranging in scientific scope from studies of the Solar System to extreme relativistic astrophysics and cosmology. It is being enabled by a new generation of large synoptic digital sky surveys - LSST, PanStarrs, CRTS - that cover large areas of sky repeatedly, looking for transient objects and phenomena. One of the biggest challenges facing these is the automated classification of transient events, a process that needs machine-processible astronomical knowledge. Semantic technologies enable the formal representation of concepts and relations within a particular domain. ATELs (http://www.astronomerstelegram.org) are a commonly-used means for reporting and commenting upon new astronomical observations of transient sources (supernovae, stellar outbursts, blazar flares, etc). However, they are loose and unstructured and employ scientific natural language for description: this makes automated processing of them - a necessity within the next decade with petascale data rates - a challenge. Nevertheless they represent a potentially rich corpus of information that could lead to new and valuable insights into transient phenomena. This project lies in the cutting-edge field of astrosemantics, a branch of astroinformatics, which applies semantic technologies to astronomy. The ATELs have been used to develop an appropriate concept scheme - a representation of the information they contain - for transient astronomy using hierarchical clustering of processed natural language. This allows us to automatically organize ATELs based on the vocabulary used. We conclude that we can use simple algorithms to process and extract meaning from astronomical textual data.

Employment of Gibbs-Donnan-based concepts for interpretation of the properties of linear polyelectrolyte solutions

USGS Publications Warehouse

Marinsky, J.A.; Reddy, M.M.

1991-01-01

Earlier research has shown that the acid dissociation and metal ion complexation equilibria of linear, weak-acid polyelectrolytes and their cross-linked gel analogues are similarly sensitive to the counterion concentration levels of their solutions. Gibbs-Donnan-based concepts, applicable to the gel, are equally applicable to the linear polyelectrolyte for the accommodation of this sensitivity to ionic strength. This result is presumed to indicate that the linear polyelectrolyte in solution develops counterion-concentrating regions that closely resemble the gel phase of their analogues. Advantage has been taken of this description of linear polyelectrolytes to estimate the solvent uptake by these regions. ?? 1991 American Chemical Society.

Comprehending the multiple 'values' of green infrastructure - Valuing nature-based solutions for urban water management from multiple perspectives.

PubMed

Wild, T C; Henneberry, J; Gill, L

2017-10-01

The valuation of urban water management practices and associated nature-based solutions (NBS) is highly contested, and is becoming increasingly important to cities seeking to increase their resilience to climate change whilst at the same time facing budgetary pressures. Different conceptions of 'values' exist, each being accompanied by a set of potential measures ranging from calculative practices (closely linked to established market valuation techniques) - through to holistic assessments that seek to address wider concerns of sustainability. Each has the potential to offer important insights that often go well beyond questions of balancing the costs and benefits of the schemes concerned. However, the need to address - and go beyond - economic considerations presents policy-makers, practitioners and researchers with difficult methodological, ethical and practical challenges, especially when considered without the benefit of a broader theoretical framework or in the absence of well-established tools (as might apply within more traditional infrastructural planning contexts, such as the analysis of transport interventions). Drawing on empirical studies undertaken in Sheffield over a period of 10 years, and delivered in partnership with several other European cities and regions, we compare and examine different attempts to evaluate the benefits of urban greening options and future development scenarios. Comparing these different approaches to the valuation of nature-based solutions alongside other, more conventional forms of infrastructure - and indeed integrating both 'green and grey' interventions within a broader framework of infrastructures - throws up some surprising results and conclusions, as well as providing important sign-posts for future research in this rapidly emerging field. Copyright © 2017 Elsevier Inc. All rights reserved.

The separation of uranium ions by natural and modified diatomite from aqueous solution.

PubMed

Sprynskyy, Myroslav; Kovalchuk, Iryna; Buszewski, Bogusław

2010-09-15

In this work the natural and the surfactant modified diatomite has been tested for ability to remove uranium ions from aqueous solutions. Such controlling factors of the adsorption process as initial uranium concentration, pH, contact time and ionic strength have been investigated. Effect of ionic strength of solution has been examined using the solutions of NaCl, Na(2)CO(3) and K(2)SO(4). The pseudo-first order and the pseudo-second order models have been used to analyze the adsorption kinetic results, whereas the Langmuir and the Freundlich isotherms have been used to the equilibrium adsorption data. The effects of the adsorbent modification as well as uranium adsorption on the diatomite surface have been studied using X-ray powder diffraction, scanning electron microscopy and FTIR spectroscopy. The maximum adsorption capacities of the natural and the modified diatomite towards uranium were 25.63 micromol/g and 667.40 micromol/g, respectively. The desorptive solutions of HCl, NaOH, Na(2)CO(3), K(2)SO(4), CaCO(3), humic acid, cool and hot water have been tested to recover uranium from the adsorbent. The highest values of uranium desorption (86%) have been reached using 0.1M HCl. Copyright 2010 Elsevier B.V. All rights reserved.

The Problematic Nature of the Artist Teacher Concept and Implications for Pedagogical Practice

ERIC Educational Resources Information Center

Hoekstra, Marike

2015-01-01

The main argument of this article is that the problematic nature of the artist teacher concept might not be the duality between art and education, but might refer to a limited understanding of education, in such a way that art would appear to be contrasting to education. A different definition of education is required to understand the qualities…

A study of Taiwanese children's conceptions of and relation to nature: Curricular and policy implications

NASA Astrophysics Data System (ADS)

Dai, Amy Hsin-I.

The present study investigated children's conceptions of and relations to nature. Understanding the factors that influence them was the goal. The study used the Contextual Model of Learning as the theoretical framework to structure the research questions and data analysis to understand children's nature learning in the personal, sociocultural, and physical contexts that change over time. Twelve children aged 5 and 6 were prompted to draw a picture of themselves in nature. They were interviewed about the sources of those ideas and living experiences, and if they thought photographs of scenery were nature. These twelve children's parents also participated in a survey to study the family influence. I used interpretational analysis to seek for common patterns and themes. Scoring rubrics, coaxial comparison, constant comparison, and the theoretical framework were used to triangulate and investigate influential factors of children's ideas of nature. The study showed that children at this age already had developed a basic conception of what is nature, but also need to learn about the role of human beings in nature and the interrelations of nature in order to develop environmental education ideas. Most children also had a positive feeling toward nature. Children's definitions of nature were developed mainly from what parents and grandparents had told them and their firsthand exposure to nature. Only during the weekend did the children's families have time to visit nature. It was found that most parents in this study stated that they were inspired by nature and were very willing to take their children to nature settings. The most visited natural places that were reported visited were parks in the city and the mountains surrounding the city. However, very often parents missed teachable opportunities to make the experiences with nature meaningful to children. Implications of the study apply to curriculum designers, educators, urban planners, and parents. It is recommended

Evolvability Is an Evolved Ability: The Coding Concept as the Arch-Unit of Natural Selection.

PubMed

Janković, Srdja; Ćirković, Milan M

2016-03-01

Physical processes that characterize living matter are qualitatively distinct in that they involve encoding and transfer of specific types of information. Such information plays an active part in the control of events that are ultimately linked to the capacity of the system to persist and multiply. This algorithmicity of life is a key prerequisite for its Darwinian evolution, driven by natural selection acting upon stochastically arising variations of the encoded information. The concept of evolvability attempts to define the total capacity of a system to evolve new encoded traits under appropriate conditions, i.e., the accessible section of total morphological space. Since this is dependent on previously evolved regulatory networks that govern information flow in the system, evolvability itself may be regarded as an evolved ability. The way information is physically written, read and modified in living cells (the "coding concept") has not changed substantially during the whole history of the Earth's biosphere. This biosphere, be it alone or one of many, is, accordingly, itself a product of natural selection, since the overall evolvability conferred by its coding concept (nucleic acids as information carriers with the "rulebook of meanings" provided by codons, as well as all the subsystems that regulate various conditional information-reading modes) certainly played a key role in enabling this biosphere to survive up to the present, through alterations of planetary conditions, including at least five catastrophic events linked to major mass extinctions. We submit that, whatever the actual prebiotic physical and chemical processes may have been on our home planet, or may, in principle, occur at some time and place in the Universe, a particular coding concept, with its respective potential to give rise to a biosphere, or class of biospheres, of a certain evolvability, may itself be regarded as a unit (indeed the arch-unit) of natural selection.

A Resource for Eliciting Student Alternative Conceptions: Examining the Adaptability of a Concept Inventory for Natural Selection at the Secondary School Level

ERIC Educational Resources Information Center

Lucero, Margaret M.; Petrosino, Anthony J.

2017-01-01

The Conceptual Inventory of Natural Selection (CINS) is an example of a research-based instrument that assesses conceptual understanding in an area that contains well-documented alternative conceptions. Much of the CINS's use and original validation has been relegated to undergraduate settings, but the information learned from student responses on…

Framework for city planning including nature-based solutions (NBS)

NASA Astrophysics Data System (ADS)

Alkan Olsson, Johanna; Sörensen, Johanna; Persson, Anna

2017-04-01

A common strategy to lower the demand for intense land use and energy consumption is the densification of urban areas. While this might be a fruitful strategy for its main objectives, one concern is that space for green areas and surface water will be decreased. Therefore, densification increases the need of strategies to develop and increase the quality of nature-based solutions (NBS) in urban areas. Smarter city planning strategies are needed, both for maintenance of existing NBS and for implementation of NBS in new developments. City planning must be based on well-evaluated solutions, which in turn must be based on a decent data material for each city. Today there is however several type of difficulties related to adequate provision of data to ensure a better implementation of NBS. The challenges arise from issues such as lack of information about for example costs of maintenance of existing NBS, citizens' perceptions and preferred use of NBS to difficulties of a more technical character such as the format of available GIS information. This study focuses on this information gap regarding NBS that persists in most cities today. The project aims to develop a framework that can help city planners to overcome the gaps and facilitate the inclusion of high quality nature-based solutions where developed or maintained. The framework, which is detailed by identifying information gaps through a literature review and selected interviews with urban planners and experts in the area of NBS, is based on the idea that well-structured and user-friendly data supporting city-planning strategies are essential to facilitate the implementation of NBS. What can be understood as well structured and user-friendly data depends on the goals and needs expressed in the strategic plans, which mean that there is a need for a close interaction between the development data and the strategic political goals expressed in the plans.

Prevalences and pregnancy outcome of vanishing twin pregnancies achieved by in vitro fertilization versus natural conception.

PubMed

Márton, Virág; Zádori, János; Kozinszky, Zoltan; Keresztúri, Attila

2016-11-01

To evaluate whether vanishing twin (VT) pregnancies achieved by in vitro fertilization and intracytoplasmic sperm injection (IVF-ICSI) had a more adverse perinatal outcome than those after natural conception. Longitudinal, retrospective cohort study. Tertiary university hospital. Three hundred and six (78 after IVF-ICSI and 228 after natural conception) VT pregnancies over a 22-year period, with VT cases matched to primarily singleton controls. None. Obstetric and neonatal outcome data. The incidence of VT was statistically significantly higher after natural conception (18.2% of twins) than after IVF-ICSI (12.6% of twins). The odds of VT in pregnancies complicated with pregestational or gestational diabetes were disproportionally higher in IVF-ICSI cases than in spontaneously conceived VT pregnancies (adjusted odds ratio [AOR]: 0.80 vs. 3.10 and 1.00 vs. 1.07, respectively). Previous induced abortion (AOR 1.34) or second-trimester fetal loss (AOR 3.3) increased the risk of VT pregnancies after spontaneous conception. Gestational diabetes mellitus in both the previous (AOR 5.41) and the present (AOR 2.3) pregnancy as well as chronic maternal diseases (AOR 3.5) and placentation anomalies all represented independent risk factors for VT after IVF-ICSI. Vanishing twin pregnancies had a lower prevalence and a worse perinatal outcome after IVF-ICSI as compared with those of their spontaneously conceived counterparts. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

A modular framework for biomedical concept recognition

PubMed Central

2013-01-01

Background Concept recognition is an essential task in biomedical information extraction, presenting several complex and unsolved challenges. The development of such solutions is typically performed in an ad-hoc manner or using general information extraction frameworks, which are not optimized for the biomedical domain and normally require the integration of complex external libraries and/or the development of custom tools. Results This article presents Neji, an open source framework optimized for biomedical concept recognition built around four key characteristics: modularity, scalability, speed, and usability. It integrates modules for biomedical natural language processing, such as sentence splitting, tokenization, lemmatization, part-of-speech tagging, chunking and dependency parsing. Concept recognition is provided through dictionary matching and machine learning with normalization methods. Neji also integrates an innovative concept tree implementation, supporting overlapped concept names and respective disambiguation techniques. The most popular input and output formats, namely Pubmed XML, IeXML, CoNLL and A1, are also supported. On top of the built-in functionalities, developers and researchers can implement new processing modules or pipelines, or use the provided command-line interface tool to build their own solutions, applying the most appropriate techniques to identify heterogeneous biomedical concepts. Neji was evaluated against three gold standard corpora with heterogeneous biomedical concepts (CRAFT, AnEM and NCBI disease corpus), achieving high performance results on named entity recognition (F1-measure for overlap matching: species 95%, cell 92%, cellular components 83%, gene and proteins 76%, chemicals 65%, biological processes and molecular functions 63%, disorders 85%, and anatomical entities 82%) and on entity normalization (F1-measure for overlap name matching and correct identifier included in the returned list of identifiers: species 88

Nature of Science and Science Content Learning. The Relation Between Students' Nature of Science Understanding and Their Learning About the Concept of Energy

NASA Astrophysics Data System (ADS)

Michel, Hanno; Neumann, Irene

2016-12-01

Besides viewing knowledge about the nature of science (NOS) as important for its own value with respect to scientific literacy, an adequate understanding of NOS is expected to improve science content learning by fostering the ability to interrelate scientific concepts and, thus, coherently acquire scientific content knowledge. However, there is a lack of systematic investigations, which clarify the relations between NOS and science content learning. In this paper, we present the results of a study, conducted to investigate how NOS understanding relates to students' acquisition of a proper understanding of the concept of energy. A total of 82 sixth and seventh grade students received an instructional unit on energy, with 41 of them receiving generic NOS instruction beforehand. This NOS instruction, however, did not result in students having higher scores on the NOS instrument. Thus, correlational analyses were performed to investigate how students' NOS understanding prior to the energy unit related to their learning about science content. Results show that a more adequate understanding of NOS might relate to students' perspective on the concept of energy and might support them in understanding the nature of energy as a theoretical concept. Students with higher NOS understanding, for example, seemed to be more capable of learning how to relate the different energy forms to each other and to justify why they can be subsumed under the term of energy. Further, we found that NOS understanding may also be related to students' approach toward energy degradation—a concept that can be difficult for students to master—while it does not seem to have a substantive impact on students' learning gain regarding energy forms, transformation, or conservation.

Exploring the Relationship between Secondary Science Teachers' Subject Matter Knowledge and Knowledge of Student Conceptions While Teaching Evolution by Natural Selection

ERIC Educational Resources Information Center

Lucero, Margaret M.; Petrosino, Anthony J.; Delgado, Cesar

2017-01-01

The fundamental scientific concept of evolution occurring by natural selection is home to many deeply held alternative conceptions and considered difficult to teach. Science teachers' subject matter knowledge (SMK) and the pedagogical content knowledge (PCK) component of knowledge of students' conceptions (KOSC) can be valuable resources for…

How to Learn the Natural Numbers: Inductive Inference and the Acquisition of Number Concepts

ERIC Educational Resources Information Center

Margolis, Eric; Laurence, Stephen

2008-01-01

Theories of number concepts often suppose that the natural numbers are acquired as children learn to count and as they draw an induction based on their interpretation of the first few count words. In a bold critique of this general approach, Rips, Asmuth, Bloomfield [Rips, L., Asmuth, J. & Bloomfield, A. (2006). Giving the boot to the bootstrap:…

Nature: a new paradigm for well-being and ergonomics.

PubMed

Richardson, Miles; Maspero, Marta; Golightly, David; Sheffield, David; Staples, Vicki; Lumber, Ryan

2017-02-01

Nature is presented as a new paradigm for ergonomics. As a discipline concerned with well-being, the importance of natural environments for wellness should be part of ergonomics knowledge and practice. This position is supported by providing a concise summary of the evidence of the value of the natural environment to well-being. Further, an emerging body of research has found relationships between well-being and a connection to nature, a concept that reveals the integrative character of human experience which can inform wider practice and epistemology in ergonomics. Practitioners are encouraged to bring nature into the workplace, so that ergonomics keeps pace with the move to nature-based solutions, but also as a necessity in the current ecological and social context. Practitioner Summary: Nature-based solutions are coming to the fore to address societal challenges such as well-being. As ergonomics is concerned with well-being, there is a need for a paradigm shift in the discipline. This position is supported by providing a concise summary of the evidence of the value of the natural environment to well-being.

Teaching optics concepts through an approach that emphasizes the colors of nature

NASA Astrophysics Data System (ADS)

Pompea, Stephen M.; Carsten-Conner, Laura D.

2015-10-01

A wide variety of optics concepts can be taught using the overall perspective of "colors of nature" as a guiding and unifying theme. This approach is attractive and interesting with a wide appeal to children, nature enthusiasts, photographers, and artists. This approach also encourages a deep understanding of the natural world and the role of coloration in biology, remote sensing, the aurora, mineralogy, meteorology, in human-made objects, and astronomy, to name a few. Third, using this theme promotes a close look at optical phenomena at all size scales-from the microscopic (e.g. silica spheres in opals) to the mid-scale (the aurora), to the largest scale (astronomical phenomena such as gaseous emission nebula). Fourth, the natural and human-constructed world provides accessible and beautiful examples of complex phenomena such as interference, diffraction, atomic and molecular emissions, Rayleigh and Mie scattering, illumination engineering, and fluorescence. These areas can be explored successfully in the context of "colors of nature". Finally, using the "colors of nature" also promotes an understanding of technology, from flashlights to streetlights, from telescopes and binoculars, to spectrometers and digital cameras. For examples something as simple as how to set the white balance on a digital camera to get a realistic looking photograph can lead to a lengthy exploration of spectrally selective surfaces and their reflectance, the nature of different illumination sources, the meaning of color temperature, and role of calibration in a digital image. We have used this approach of teaching using the colors of nature as an organizing theme in our NSF-funded project "Project STEAM: Integrating Art with Science to Build Science Identities Among Girls" (colorsofnature.org).

Fuels Containing Methane of Natural Gas in Solution

NASA Technical Reports Server (NTRS)

Sullivan, Thomas A.

2004-01-01

While exploring ways of producing better fuels for propulsion of a spacecraft on the Mars sample return mission, a researcher at Johnson Space Center (JSC) devised a way of blending fuel by combining methane or natural gas with a second fuel to produce a fuel that can be maintained in liquid form at ambient temperature and under moderate pressure. The use of such a blended fuel would be a departure for both spacecraft engines and terrestrial internal combustion engines. For spacecraft, it would enable reduction of weights on long flights. For the automotive industry on Earth, such a fuel could be easily distributed and could be a less expensive, more efficient, and cleaner-burning alternative to conventional fossil fuels. The concept of blending fuels is not new: for example, the production of gasoline includes the addition of liquid octane enhancers. For the future, it has been commonly suggested to substitute methane or compressed natural gas for octane-enhanced gasoline as a fuel for internal-combustion engines. Unfortunately, methane or natural gas must be stored either as a compressed gas (if kept at ambient temperature) or as a cryogenic liquid. The ranges of automobiles would be reduced from their present values because of limitations on the capacities for storage of these fuels. Moreover, technical challenges are posed by the need to develop equipment to handle these fuels and, especially, to fill tanks acceptably rapidly. The JSC alternative to provide a blended fuel that can be maintained in liquid form at moderate pressure at ambient temperature has not been previously tried. A blended automotive fuel according to this approach would be made by dissolving natural gas in gasoline. The autogenous pressure of this fuel would eliminate the need for a vehicle fuel pump, but a pressure and/or flow regulator would be needed to moderate the effects of temperature and to respond to changing engine power demands. Because the fuel would flash as it entered engine

A conceptual change analysis of nature of science conceptions: The deep roots and entangled vines of a conceptual ecology

NASA Astrophysics Data System (ADS)

Johnston, Adam Thomas

This research used theories of conceptual change to analyze learners' understandings of the nature of science (NOS). Ideas regarding the NOS have been advocated as vital aspects of science literacy, yet learners at many levels (students and teachers) have difficulty in understanding these aspects in the way that science literacy reforms advocate. Although previous research has shown the inadequacies in learners' NOS understandings and have documented ways by which to improve some of these understandings, little has been done to show how these ideas develop and why learners' preexisting conceptions of NOS are so resistant to conceptual change. The premise of this study, then, was to describe the nature of NOS conceptions and of the conceptual change process itself by deeply analyzing the conceptions of individual learners. Toward this end, 4 individuals enrolled in a physical science course designed for preservice elementary teachers were selected to participate in a qualitative research study. These individuals answered questionnaires, surveys, direct interview questions, and a variety of interview probes (e.g., critical incidents, responses to readings/videos, reflections on coursework, card sorting tasks, etc.) which were administered throughout the duration of a semester. By utilizing these in-depth, qualitative probes, learners' conceptions were not only assessed but also described in great detail, revealing the source of their conceptions as well as identifying many instances in which a learner's directly stated conception was contradictory to that which was reflected by more indirect probes. As a result of this research, implications regarding NOS conceptions and their development have been described. In addition, various descriptions of conceptual change have been further refined and informed. Especially notable, the influence of a learner's conceptual ecology and its extrarational influences on conceptual change have been highlighted. It is argued that

Thai and Bangladeshi In-Service Science Teachers' Conceptions of Nature of Science: A Comparative Study

ERIC Educational Resources Information Center

Buaraphan, Khajornsak; Abedin Forhad, Ziaul

2014-01-01

Understanding of nature of science (NOS) serves as one of the desirable characteristics of science teachers. The current study explored 55 Thai and 110 Bangladeshi in-service secondary science teachers' conceptions of NOS regarding scientific knowledge, scientific method, scientists' work, and scientific enterprise, by using the Myths of Science…

Some new exact solitary wave solutions of the van der Waals model arising in nature

NASA Astrophysics Data System (ADS)

Bibi, Sadaf; Ahmed, Naveed; Khan, Umar; Mohyud-Din, Syed Tauseef

2018-06-01

This work proposes two well-known methods, namely, Exponential rational function method (ERFM) and Generalized Kudryashov method (GKM) to seek new exact solutions of the van der Waals normal form for the fluidized granular matter, linked with natural phenomena and industrial applications. New soliton solutions such as kink, periodic and solitary wave solutions are established coupled with 2D and 3D graphical patterns for clarity of physical features. Our comparison reveals that the said methods excel several existing methods. The worked-out solutions show that the suggested methods are simple and reliable as compared to many other approaches which tackle nonlinear equations stemming from applied sciences.

The concept of sustainable prefab modular housing made of natural fiber reinforced polymer (NFRP)

NASA Astrophysics Data System (ADS)

Setyowati, E.; Pandelaki, E. E.

2018-03-01

This research aims to formulate the concept of public housing based on research results on natural fiber reinforced polymer (FRP) material which has been done in the road map of research. Research output is the public housing design and specifications of FRP made of water hyacinths and coconut fiber. Method used is descriptive review of the concept based on references and material test which consists of density, water absorption, modulus of rupture (MOR), tensile strength, absorption coefficient and Sound Transmission Loss (STL). The entire tests of material were carried out in the laboratory of materials and construction, while the acoustic tests carried out using the impedance tubes method. The test results concluded that the FRP material may have a density between 0.2481 – 0.2777 g/cm3, the absorption coefficient is average of 0.450 – 0.900, the Modulus of Elasticity is between 4061 – 15193 kg/cm2, while the average of sound transmission loss is 52 – 59 dB. Furthermore, that the concept of public housing must be able to be the embryo of the concept of environment-friendly and low emissions housing.

The nature of multiple solutions for surface wind speed over the oceans from scatterometer measurements

NASA Technical Reports Server (NTRS)

Price, J. C.

1975-01-01

The satellite SEASAT-A will carry a radar scatterometer in order to measure microwave backscatter from the sea surface. From pairs of radar measurements at angles separated by 90 deg in azimuth the surface wind speed and direction may be inferred, though not uniquely. The character of the solutions for wind speed and direction is displayed, as well as the nature of the ambiguities of these solutions. An economical procedure for handling such data is described, plus a criterion for the need for conventional (surface) data in order to resolve the ambiguities of solutions.

Nature of Science and Science Content Learning: The Relation between Students' Nature of Science Understanding and Their Learning about the Concept of Energy

ERIC Educational Resources Information Center

Michel, Hanno; Neumann, Irene

2016-01-01

Besides viewing knowledge about the nature of science (NOS) as important for its own value with respect to scientific literacy, an adequate understanding of NOS is expected to improve science content learning by fostering the ability to interrelate scientific concepts and, thus, coherently acquire scientific content knowledge. However, there is a…

Capturing the multiple benefits associated with nature-based solutions: lessons from natural flood management project in the Cotswolds, UK

NASA Astrophysics Data System (ADS)

Short, Chrisopher; Clarke, Lucy; Uttley, Chris; Smith, Brian

2017-04-01

Following severe flooding in 2007, and subsequent smaller flood events, a decision was taken in 2012 to explore nature-based solutions in 250km2 river catchment in the southern Cotswolds in the UK. A major tributary within the catchment has been designated as rapid response; with a primarily limestone geology limestone and a mixture of spring and surface drained sources along a number of tributaries feeding in the river, with one main population centre where the water bodies converge. The project involves landscape and land management interventions aimed at attenuating high flows to reduce flood risk through changes in land management practices in both agriculture and forestry and slowing peak flows in surface flows through increased infiltration and attenuation areas. After three years of the project it is clear that the threshold for effectiveness requires the majority of the upstream catchment area to be implementing these measures. However, the cost effectiveness of the approach seems to be substantial compared to traditional hard-engineering approaches. The level of community involvement, including local flood forums, is high and the social, and natural, capital has been enhanced through the project. Early results suggest that there have been localized improvements in water quality and biodiversity as well as a reduction in peak flow but such changes are difficult to directly associate to the project. What is clear is the role of communities, landowners and partners to implement natural flood management on a catchment wide scale. In this sense the project has adopted a co-management or adaptive management approach which brings together the knowledges of hydrologists, ecologists, farmers, woodland owners and the local community to implement locally be-spoke solutions within a broader project framework. This paper will outline the initial findings and the governance structure that has assisted in the early success of the project within a theoretical framework of

Students' Conceptions of the Nature of Science: Perspectives from Canadian and Korean Middle School Students

ERIC Educational Resources Information Center

Park, Hyeran; Nielsen, Wendy; Woodruff, Earl

2014-01-01

This study examined and compared students' understanding of nature of science (NOS) with 521 Grade 8 Canadian and Korean students using a mixed methods approach. The concepts of NOS were measured using a survey that had both quantitative and qualitative elements. Descriptive statistics and one-way multivariate analysis of variances examined the…

Monitoring the Impact of Solution Concepts within a Given Problematic

NASA Astrophysics Data System (ADS)

Cavallucci, Denis; Rousselot, François; Zanni, Cecilia

It is acknowledged that one of the most critical issues facing today’s organizations concerns the substantial leaps required to methodologically structure innovation. Among other published work, some suggest that a complete rethinking of current practices is required. In this article, we propose a methodology aiming at providing controlled R&D choices based on a monitoring of the impact Solution Concepts provoke on a problematic situation. Initially this problematic situation is modeled in a graph form, namely a Problem Graph. It has the objective to assists R&D managers when choosing which activities to support and bring them concrete arguments to defend their choices. We postulate that by improving the robustness of such approaches we help deciders to switch from intuitive decisions (mostly built upon their past experiences, fear regarding risks, and awareness of the company’s level of acceptance of novelties) to thoroughly constructed inventive problem solving strategies. Our approach will be discussed using a computer application that illustrates our hypothesis after being tested in several industrial applications.

Nature, Human Nature, and Solutions to Problems.

ERIC Educational Resources Information Center

Pedrini, D. T.; Pedrini, B. C.

This paper promotes an undergraduate course that would discuss the great ideas of Plato, St. Paul, Karl Marx, Sigmund Freud, Jean Paul Sartre, B. F. Skinner, and Konrad Lorenz. This course would help students understand human values and behaviors while focusing on historical, world, and national problems. Tentative solutions would then be…

Investigating inquiry beliefs and nature of science (NOS) conceptions of science teachers as revealed through online learning

NASA Astrophysics Data System (ADS)

Atar, Hakan Yavuz

teachers NOS conceptions. Developing desired understanding of nature of science conceptions and having an adequate experience with inquiry learning is especially important for science teachers because science education literature suggests that the development of teachers' nature of science conceptions is influenced by their experiences with inquiry science (Akerson et. al. 2000) and implementation of science lessons reflect teachers' NOS conceptions (Abd-EL-Khalick & Boujaoude, 1997; Matson & Parsons, 1998; Rosenthal, 1993; Trowbridge, Bybee & Powell, 2000; Turner & Sullenger, 1999). Furthermore, the impediments to successful integration of inquiry based science instruction from teachers' perspective are particularly important, as they are the implementers of inquiry based science education reform. The purpose of this study is to understand the relationship between the teachers' NOS conceptions and their inquiry beliefs and practices in their classrooms and how this relationship impedes or contributes to the implementation of inquiry based science education reform efforts. The participants of this study were in-service teachers who were accepted into the online Masters Program in science education program at a southern university. Three online courses offered in the summer semester of 2005 constituted the research setting of this study: (1) Special Problems in the Teaching of Secondary School Science: Nature of Science & Science Teaching, (2) Curriculum in Science Education, and (3) Colloquium. Multiple data sources were used for data triangulation (Miles & Huberman, 1984; Yin, 1994) in order to understand the relationship between participants' NOS views and their conceptions and beliefs about inquiry-based science teaching. The study revealed that the relationship between the teachers' NOS conceptions and their inquiry beliefs and practices is far from being simple and linear. Data suggests that the teachers' sophistication of NOS conceptions influence their perception of

Hegel's Concept of Education from the Point of View of His Idea of 'Second Nature'

ERIC Educational Resources Information Center

Zovko, Jure

2018-01-01

This article explores Hegels concept of education within the context of his idea of 'second nature'. Hegel believes that institutional life forms, which have been formed through education, culture, technical and social progress, constitute the 'second nature' of human beings. The immediacy of institutional forms which act as humans' 'second…

Multi-period natural gas market modeling Applications, stochastic extensions and solution approaches

NASA Astrophysics Data System (ADS)

Egging, Rudolf Gerardus

This dissertation develops deterministic and stochastic multi-period mixed complementarity problems (MCP) for the global natural gas market, as well as solution approaches for large-scale stochastic MCP. The deterministic model is unique in the combination of the level of detail of the actors in the natural gas markets and the transport options, the detailed regional and global coverage, the multi-period approach with endogenous capacity expansions for transportation and storage infrastructure, the seasonal variation in demand and the representation of market power according to Nash-Cournot theory. The model is applied to several scenarios for the natural gas market that cover the formation of a cartel by the members of the Gas Exporting Countries Forum, a low availability of unconventional gas in the United States, and cost reductions in long-distance gas transportation. 1 The results provide insights in how different regions are affected by various developments, in terms of production, consumption, traded volumes, prices and profits of market participants. The stochastic MCP is developed and applied to a global natural gas market problem with four scenarios for a time horizon until 2050 with nineteen regions and containing 78,768 variables. The scenarios vary in the possibility of a gas market cartel formation and varying depletion rates of gas reserves in the major gas importing regions. Outcomes for hedging decisions of market participants show some significant shifts in the timing and location of infrastructure investments, thereby affecting local market situations. A first application of Benders decomposition (BD) is presented to solve a large-scale stochastic MCP for the global gas market with many hundreds of first-stage capacity expansion variables and market players exerting various levels of market power. The largest problem solved successfully using BD contained 47,373 variables of which 763 first-stage variables, however using BD did not result in

Using concepts from biology to improve problem-solving methods

NASA Astrophysics Data System (ADS)

Goodman, Erik D.; Rothwell, Edward J.; Averill, Ronald C.

2011-06-01

Observing nature has been a cornerstone of engineering design. Today, engineers look not only at finished products, but imitate the evolutionary process by which highly optimized artifacts have appeared in nature. Evolutionary computation began by capturing only the simplest ideas of evolution, but today, researchers study natural evolution and incorporate an increasing number of concepts in order to evolve solutions to complex engineering problems. At the new BEACON Center for the Study of Evolution in Action, studies in the lab and field and in silico are laying the groundwork for new tools for evolutionary engineering design. This paper, which accompanies a keynote address, describes various steps in development and application of evolutionary computation, particularly as regards sensor design, and sets the stage for future advances.

A Logico-Structural, Worldview Analysis of the Interrelationship between Science Interest, Gender, and Concept of Nature.

ERIC Educational Resources Information Center

Cobern, William W.; And Others

The purpose of this research was to provide information about gender-related worldview structures, among college students, that can inform the instructional decision making process. Information was generated in a logico-structural investigation of the interrelationship of gender, interest in science, and concept of nature. The strength of the…

Weak solution concept and Galerkin's matrix for the exterior of an oblate ellipsoid of revolution in the representation of the Earth's gravity potential by buried masses

NASA Astrophysics Data System (ADS)

Holota, Petr; Nesvadba, Otakar

2017-04-01

The paper is motivated by the role of boundary value problems in Earth's gravity field studies. The discussion focuses on Neumann's problem formulated for the exterior of an oblate ellipsoid of revolution as this is considered a basis for an iteration solution of the linear gravimetric boundary value problem in the determination of the disturbing potential. The approach follows the concept of the weak solution and Galerkin's approximations are applied. This means that the solution of the problem is approximated by linear combinations of basis functions with scalar coefficients. The construction of Galerkin's matrix for basis functions generated by elementary potentials (point masses) is discussed. Ellipsoidal harmonics are used as a natural tool and the elementary potentials are expressed by means of series of ellipsoidal harmonics. The problem, however, is the summation of the series that represent the entries of Galerkin's matrix. It is difficult to reduce the number of summation indices since in the ellipsoidal case there is no analogue to the addition theorem known for spherical harmonics. Therefore, the straightforward application of series of ellipsoidal harmonics is complemented by deeper relations contained in the theory of ordinary differential equations of second order and in the theory of Legendre's functions. Subsequently, also hypergeometric functions and series are used. Moreover, within some approximations the entries are split into parts. Some of the resulting series may be summed relatively easily, apart from technical tricks. For the remaining series the summation was converted to elliptic integrals. The approach made it possible to deduce a closed (though approximate) form representation of the entries in Galerkin's matrix. The result rests on concepts and methods of mathematical analysis. In the paper it is confronted with a direct numerical approach applied for the implementation of Legendre's functions. The computation of the entries is more

Nature as an engineer: one simple concept of a bio-inspired functional artificial muscle.

PubMed

Schmitt, S; Haeufle, D F B; Blickhan, R; Günther, M

2012-09-01

The biological muscle is a powerful, flexible and versatile actuator. Its intrinsic characteristics determine the way how movements are generated and controlled. Robotic and prosthetic applications expect to profit from relying on bio-inspired actuators which exhibit natural (muscle-like) characteristics. As of today, when constructing a technical actuator, it is not possible to copy the exact molecular structure of a biological muscle. Alternatively, the question may be put how its characteristics can be realized with known mechanical components. Recently, a mechanical construct for an artificial muscle was proposed, which exhibits hyperbolic force-velocity characteristics. In this paper, we promote the constructing concept which is made by substantiating the mechanical design of biological muscle by a simple model, proving the feasibility of its real-world implementation, and checking their output both for mutual consistency and agreement with biological measurements. In particular, the relations of force, enthalpy rate and mechanical efficiency versus contraction velocity of both the construct's technical implementation and its numerical model were determined in quick-release experiments. All model predictions for these relations and the hardware results are now in good agreement with the biological literature. We conclude that the construct represents a mechanical concept of natural actuation, which is suitable for laying down some useful suggestions when designing bio-inspired actuators.

A novel LCD (coal tar) solution for psoriasis does not discolor naturally light or color-processed hair in an exaggerated exposure test model.

PubMed

Johnson, Colleen; Edison, Brenda; Brouda, Irina; Green, Barbara

2009-09-01

Scalp psoriasis is reported to occur in 50-80% of psoriasis sufferers. Treatment of scalp psoriasis requires special consideration of product esthetics and staining potential due to the presence of hair. To evaluate the potential of a new, marketed liquor carbonis distillate (LCD; coal tar) solution to discolor naturally light or color-processed hair under exaggerated exposure conditions. Samples of naturally light and color-processed hair from a single donor were exposed to LCD solution repeatedly over 14 days and via submergence for 24 h. Color of LCD-treated hair samples was compared with untreated control hair samples. LCD solution did not discolor naturally light or color-processed hair following repeated exposures and 24 h submergence. The marketed LCD solution does not appear to discolor naturally light or color-processed hair.

Natural Hazard Problem and Solution Definition in the News Media: the Case of Tropical Storm Allison

NASA Astrophysics Data System (ADS)

Lindquist, Eric; Mosher-Howe, Katrina

2010-05-01

Focusing events such as natural or technological disasters can have significant impacts on public policy and planning in both the near and long term. These impacts can manifest at different temporal scales ranging from the period of immediate attention and disaster relief through the period of recovery and reconstruction and beyond. These impacts and associated decisions can be studied in retrospect and understood as not only short-term reactions, but as long-term components of subsequent natural hazard planning and public policy. By studying in detail how an event was defined, and the policy and planning alternatives that were raised or recommended in response to a disaster event, we can better understand the role that disaster-related focusing events play in the long-term evolution of a community's public policy, infrastructural planning efforts, and responses to natural disasters. This paper will use a focusing event framework to explore the local and regional policy impacts over time of a major urban flood in Houston, Texas, Tropical Storm Allison. Tropical Storm Allison (TSA), dropped 36 inches of rain on Houston over a period of four days in early June 2001, and was responsible for 22 deaths, 70,000 flood damaged homes, and 5 billion in damage to the region. The primary data source for this effort is a database of 500 articles from the major regional newspaper, the Houston Chronicle, over the period of 2001 through 2008. These articles were coded for multiple variables, including, cause, effect and impact (financial and social), blame, problem and solution definition and solution acceptance). This paper focuses primarily on the measures of problem definition (how was TSA, as an event, defined in the media, for example, as an act of God, or as a result of poor planning or decision making, etc), and on solution definition (what solutions were proposed to mitigate or adapt to future storms of this magnitude, how were they linked to the definition of the problem

Evaluating the potential of multi-purpose nature based solutions in peri-urban landscapes - a preliminary assessment

NASA Astrophysics Data System (ADS)

Geris, Josie; Wilkinson, Mark; Stutter, Marc; Guenther, Daniel; Soulsby, Chris

2016-04-01

Many communities across the world face the increasing challenge of balancing water quantity and quality protection and improvement with accommodating new growth and urban development. Urbanisation is typically associated with detrimental changes in water quality, sediment delivery, and effects on water storage and flow pathways (e.g. increases in flooding). Current mitigation solutions are typically based on isolated design strategies used at specific small scale sites and for storm water only. More holistic catchment scale approaches are urgently required to effectively manage the amount of water flows and protect the raw water quality in peri-urban landscapes. This project aims to provide a better understanding of the connectivity between natural and managed flow pathways, storage, and biogeochemical processes in the peri-urban landscape to eventually aid a more integrated water quantity and quality control design. For an actively urbanising catchment in NE Scotland we seek to understand the spatio-temporal character of the natural flow pathways and associated water quality, and how these may be used to support the design of nature based solutions during urbanisation. We present preliminary findings from a dense and multiscale monitoring network that includes hydrometric, tracer (stable water isotopes) and water quality (turbidity (sediment), nitrate, phosphate) data during a range of contrasting hydroclimatological conditions and at different stages of the development of urban infrastructure. These demonstrate a highly variable nature, both temporally and spatially, with water quality dynamics out of sync with storm responses and depending on management practices. This highlights potential difficulties for managing water quantity and quality simultaneously at the catchment scale, and suggests that a treatment train approach may be required. Well-designed nature based solutions that tackle both water quantity and quality issues will require adaptability and a

An Analysis of 16-17-Year-Old Students' Understanding of Solution Chemistry Concepts Using a Two-Tier Diagnostic Instrument

ERIC Educational Resources Information Center

Adadan, Emine; Savasci, Funda

2012-01-01

This study focused on the development of a two-tier multiple-choice diagnostic instrument, which was designed and then progressively modified, and implemented to assess students' understanding of solution chemistry concepts. The results of the study are derived from the responses of 756 Grade 11 students (age 16-17) from 14 different high schools…

Dynamics of a Definition: A Framework to Analyse Student Construction of the Concept of Solution to a Differential Equation

ERIC Educational Resources Information Center

Raychaudhuri, Debasree

2008-01-01

In this note we develop a framework that makes explicit the inherent dynamic structure of certain mathematical definitions by means of the four facets of context-entity-process-object. These facets and their interrelations are then used to capture and interpret specific aspects of student constructions of the concept of solution to first order…

Studies on desorption and regeneration of natural pumice for iron removal from aqueous solution.

PubMed

Indah, S; Helard, D; Binuwara, A

2018-05-01

To make the adsorption process more economic and environmental friendly, it is necessary to study desorption and reutilization of the adsorbents. In the present study, the effectiveness of natural pumice in removal of iron from aqueous solution was investigated in several sorption-desorption cycles. The desorption characteristics of previously adsorbed iron ions on natural pumice were tested by various desorbing agents such as HCl, NaOH and aquadest. Among them, HCl showed the highest desorption efficiency (37.89%) with 0.1 M of concentration and 60 min of contact time. The removal efficiency of iron ions in reused natural pumice could be maintained up to 90% in the third cycle of adsorption. The results indicate that although complete desorption was not achieved, natural pumice from Sungai Pasak, West Sumatra, Indonesia, can be sufficiently reused up to three cycles of adsorption-desorption.

Linking social, ecological, and physical science to advance natural and nature-based protection for coastal communities.

PubMed

Arkema, Katie K; Griffin, Robert; Maldonado, Sergio; Silver, Jessica; Suckale, Jenny; Guerry, Anne D

2017-07-01

Interest in the role that ecosystems play in reducing the impacts of coastal hazards has grown dramatically. Yet the magnitude and nature of their effects are highly context dependent, making it difficult to know under what conditions coastal habitats, such as saltmarshes, reefs, and forests, are likely to be effective for saving lives and protecting property. We operationalize the concept of natural and nature-based solutions for coastal protection by adopting an ecosystem services framework that propagates the outcome of a management action through ecosystems to societal benefits. We review the literature on the basis of the steps in this framework, considering not only the supply of coastal protection provided by ecosystems but also the demand for protective services from beneficiaries. We recommend further attention to (1) biophysical processes beyond wave attenuation, (2) the combined effects of multiple habitat types (e.g., reefs, vegetation), (3) marginal values and expected damage functions, and, in particular, (4) community dependence on ecosystems for coastal protection and co-benefits. We apply our approach to two case studies to illustrate how estimates of multiple benefits and losses can inform restoration and development decisions. Finally, we discuss frontiers for linking social, ecological, and physical science to advance natural and nature-based solutions to coastal protection. © 2017 New York Academy of Sciences.

The World Atlas of Desertification assessment concept for conscious land use solutions

NASA Astrophysics Data System (ADS)

Cherlet, Michael; Ivits, Eva; Kutnjak, Hrvoje; Smid, Marek; Sommer, Stefan; Zucca, Claudio

2015-04-01

Land degradation and desertification are complex phenomena that result in environmental damage, economic inefficiency and social inequity and are reflected by a reducing productive capacity of the land and soil. Research indicated that they are driven by a multiple but a limited number of causal aspects that unbalance the capacity of the environment system to sustainably produce ecosystem services and economic value. Competition for land, driven by societal needs or economic opportunities, adds further stress on the land resources. To address these complex global challenges, a monitoring and assessment system offering up-to-date information on the status and trends of land degradation and their causes and effects is needed to provide science-based routes for possible land use solutions. The assessment concept that has been outlined for the compilation of the new World Atlas of Desertification (WAD) confronts this complexity by converging evidence of stress on the land system caused by various issues. These issues relate to sets of dynamics of the human-environment system and include changing agricultural or pastoral land use and management practices, changing population and societal aspects, changing aridity and drought. The WAD describes the issues, spatially documents their change, whenever data is available, highlights the importance of the issues in relation to land degradation processes and illustrates the integrated assessment concepts. The first step is the preparation of solid global data layers that are related to, or express aspects that can be related to, land-system productivity dynamics and status. These can be used for identifying and evaluating the interaction of spatial variables with the land-system productivity dynamics. Initial analysis of the land productivity dynamics within stratified land cover/use areas, such as the global croplands, show substantial differences in the extension, geographic location and possible related causes of potentially

On the normativity of human nature: some epistemological remarks.

PubMed

Corradini, Antonella

2003-04-01

This paper examines the role played by the concept of human nature in ethical theory. The focus is on the epistemological problems that arise from application of this notion to the foundation of ethics. From this viewpoint, two theories, the neoscholastic and the neoclassical ones, are expounded, analyzed and compared. The aim is to highlight their opposite ways of relating the "ought-to-be" (of norms) to the "is" (of human nature). The conclusion is drawn that an adequate solution of the dispute depends on a correct interpretation of Hume's law. Reflection is conducted in the last section on the implications of metaethical discourse on human nature for applied ethics.

An Investigation into the Relationship between Students' Conceptions of the Particulate Nature of Matter and Their Understanding of Chemical Bonding

ERIC Educational Resources Information Center

Othman, Jazilah; Treagust, David F.; Chandrasegaran, A. L.

2008-01-01

A thorough understanding of chemical bonding requires familiarity with the particulate nature of matter. In this study, a two-tier multiple-choice diagnostic instrument consisting of ten items (five items involving each of the two concepts) was developed to assess students' understanding of the particulate nature of matter and chemical bonding so…

Complete factorisation and analytic solutions of generalized Lotka-Volterra equations

NASA Astrophysics Data System (ADS)

Brenig, L.

1988-11-01

It is shown that many systems of nonlinear differential equations of interest in various fields are naturally imbedded in a new family of differential equations. This family is invariant under nonlinear transformations based on the concept of matrix power of a vector. Each equation belonging to that family can be brought into a factorized canonical form for which integrable cases can be easily identified and solutions can be found by quadratures.

Urban e-Mobility - Challenges and potential solutions using the example of the "E3W" concept vehicle

NASA Astrophysics Data System (ADS)

Perterer, M.; Martin, P.; Lochner, H.

2014-05-01

Due to the increasing number of people in urban areas, there is a need for affordable individual transportation. Limited space in cities together with the need for a significant reduction of pollution will lead to new mobility concepts in the near future. The aim of these concepts is not replacing the car itself, but to supply an additional personal transportation solution with local zero emission. Therefore, electrical powered vehicle concepts may be used. Due to the limited energy density and high cost of current Li-ion batteries, a significant weight reduction of the vehicle could lead to acceptable range and cost. In order to develop an affordable urban concept, the requirements for this kind of vehicle also have to be adjusted in comparison to conventional cars. This concept, the so called "E3W", combines the advantages of a two-wheeler with those of a four-wheeler, resulting in a lightweight and compact vehicle. This concept accommodates space for two persons with luggage and guarantees a high level of safety including wind and weather protection. The overall measures of this vehicle are smaller than current compact cars and allow therefore better use in cities. In order to fulfill technical and commercial requirements, a load carrying, short fiber reinforced thermoplastic body structure is chosen, combining good weight specific mechanical properties and low production costs. This highly integrated body structure also provides the body cover all in one. Pultruded glass fiber reinforced plastic (GFRP) beams are used as the backbone for the vehicle by carrying the main loads, the front crash structure and the rear swingarm. Finally, two prototypes are built to investigate the driving behavior, proof the concept and the suitability for daily use.

Suppressing Synonymy with a Homonym: The Emergence of the Nomenclatural Type Concept in Nineteenth Century Natural History.

PubMed

Witteveen, Joeri

2016-02-01

'Type' in biology is a polysemous term. In a landmark article, Paul Farber (Journal of the History of Biology 9(1): 93-119, 1976) argued that this deceptively plain term had acquired three different meanings in early nineteenth century natural history alone. 'Type' was used in relation to three distinct type concepts, each of them associated with a different set of practices. Important as Farber's analysis has been for the historiography of natural history, his account conceals an important dimension of early nineteenth century 'type talk.' Farber's taxonomy of type concepts passes over the fact that certain uses of 'type' began to take on a new meaning in this period. At the closing of the eighteenth century, terms like 'type specimen,' 'type species,' and 'type genus' were universally recognized as referring to typical, model members of their encompassing taxa. But in the course of the nineteenth century, the same terms were co-opted for a different purpose. As part of an effort to drive out nomenclatural synonymy - the confusing state of a taxon being known to different people by different names - these terms started to signify the fixed and potentially atypical name-bearing elements of taxa. A new type concept was born: the nomenclatural type. In this article, I retrace this perplexing nineteenth century shift in meaning of 'type.' I uncover the nomenclatural disorder that the new nomenclatural type concept dissolved, and expose the conceptual confusion it left in its tracks. What emerges is an account of how synonymy was suppressed through the coinage of a homonym.

Wetlands as large-scale nature-based solutions: status and future challenges for research and management

NASA Astrophysics Data System (ADS)

Thorslund, Josefin; Jarsjö, Jerker; Destouni, Georgia

2017-04-01

Wetlands are often considered as nature-based solutions that can provide a multitude of services of great social, economic and environmental value to humankind. The services may include recreation, greenhouse gas sequestration, contaminant retention, coastal protection, groundwater level and soil moisture regulation, flood regulation and biodiversity support. Changes in land-use, water use and climate can all impact wetland functions and occur at scales extending well beyond the local scale of an individual wetland. However, in practical applications, management decisions usually regard and focus on individual wetland sites and local conditions. To understand the potential usefulness and services of wetlands as larger-scale nature-based solutions, e.g. for mitigating negative impacts from large-scale change pressures, one needs to understand the combined function multiple wetlands at the relevant large scales. We here systematically investigate if and to what extent research so far has addressed the large-scale dynamics of landscape systems with multiple wetlands, which are likely to be relevant for understanding impacts of regional to global change. Our investigation regards key changes and impacts of relevance for nature-based solutions, such as large-scale nutrient and pollution retention, flow regulation and coastal protection. Although such large-scale knowledge is still limited, evidence suggests that the aggregated functions and effects of multiple wetlands in the landscape can differ considerably from those observed at individual wetlands. Such scale differences may have important implications for wetland function-effect predictability and management under large-scale change pressures and impacts, such as those of climate change.

From grey to green: Efficacy of eco-engineering solutions for nature-based coastal defence.

PubMed

Morris, Rebecca L; Konlechner, Teresa M; Ghisalberti, Marco; Swearer, Stephen E

2018-05-01

Climate change is increasing the threat of erosion and flooding along coastlines globally. Engineering solutions (e.g. seawalls and breakwaters) in response to protecting coastal communities and associated infrastructure are increasingly becoming economically and ecologically unsustainable. This has led to recommendations to create or restore natural habitats, such as sand dunes, saltmarsh, mangroves, seagrass and kelp beds, and coral and shellfish reefs, to provide coastal protection in place of (or to complement) artificial structures. Coastal managers are frequently faced with the problem of an eroding coastline, which requires a decision on what mitigation options are most appropriate to implement. A barrier to uptake of nature-based coastal defence is stringent evaluation of the effectiveness in comparison to artificial protection structures. Here, we assess the current evidence for the efficacy of nature-based vs. artificial coastal protection and discuss future research needs. Future projects should evaluate habitats created or restored for coastal defence for cost-effectiveness in comparison to an artificial structure under the same environmental conditions. Cost-benefit analyses should take into consideration all ecosystem services provided by nature-based or artificial structures in addition to coastal protection. Interdisciplinary research among scientists, coastal managers and engineers is required to facilitate the experimental trials needed to test the value of these shoreline protection schemes, in order to support their use as alternatives to artificial structures. This research needs to happen now as our rapidly changing climate requires new and innovative solutions to reduce the vulnerability of coastal communities to an increasingly uncertain future. © 2018 John Wiley & Sons Ltd.

Students' Conceptions of the Nature of Science: Perspectives from Canadian and Korean Middle School Students

NASA Astrophysics Data System (ADS)

Park, Hyeran; Nielsen, Wendy; Woodruff, Earl

2014-05-01

This study examined and compared students' understanding of nature of science (NOS) with 521 Grade 8 Canadian and Korean students using a mixed methods approach. The concepts of NOS were measured using a survey that had both quantitative and qualitative elements. Descriptive statistics and one-way multivariate analysis of variances examined the quantitative data while a conceptually clustered matrix classified the open-ended responses. The country effect could explain 3-12 % of the variances of subjectivity, empirical testability and diverse methods, but it was not significant for the concepts of tentativeness and socio-cultural embeddedness of science. The open-ended responses showed that students believed scientific theories change due to errors or discoveries. Students regarded empirical evidence as undeniable and objective although they acknowledged experiments depend on theories or scientists' knowledge. The open responses revealed that national situations and curriculum content affected their views. For our future democratic citizens to gain scientific literacy, science curricula should include currently acknowledged NOS concepts and should be situated within societal and cultural perspectives.

A Resource for Eliciting Student Alternative Conceptions: Examining the Adaptability of a Concept Inventory for Natural Selection at the Secondary School Level

NASA Astrophysics Data System (ADS)

Lucero, Margaret M.; Petrosino, Anthony J.

2017-08-01

The Conceptual Inventory of Natural Selection (CINS) is an example of a research-based instrument that assesses conceptual understanding in an area that contains well-documented alternative conceptions. Much of the CINS's use and original validation has been relegated to undergraduate settings, but the information learned from student responses on the CINS can also potentially be a useful resource for teachers at the secondary level. Because of its structure, the CINS can have a role in eliciting alternative conceptions and induce deeper conceptual understanding by having student ideas leveraged during instruction. In a first step toward this goal, the present study further investigated the CINS's internal properties by having it administered to a group ( n = 339) of students among four different biology teachers at a predominantly Latino, economically disadvantaged high school. In addition, incidences of the concept inventory's use among the teachers' practices were collected for support of its adaptability at the secondary level. Despite the teachers' initial enthusiasm for the CINS's use as an assessment tool in the present study, results from a principal components analysis demonstrate inconsistencies between the original and present validations. Results also reveal how the teachers think CINS items may be revised for future use among secondary student populations.

Growing three-dimensional biomorphic graphene powders using naturally abundant diatomite templates towards high solution processability

NASA Astrophysics Data System (ADS)

Chen, Ke; Li, Cong; Shi, Liurong; Gao, Teng; Song, Xiuju; Bachmatiuk, Alicja; Zou, Zhiyu; Deng, Bing; Ji, Qingqing; Ma, Donglin; Peng, Hailin; Du, Zuliang; Rümmeli, Mark Hermann; Zhang, Yanfeng; Liu, Zhongfan

2016-11-01

Mass production of high-quality graphene with low cost is the footstone for its widespread practical applications. We present herein a self-limited growth approach for producing graphene powders by a small-methane-flow chemical vapour deposition process on naturally abundant and industrially widely used diatomite (biosilica) substrates. Distinct from the chemically exfoliated graphene, thus-produced biomorphic graphene is highly crystallized with atomic layer-thickness controllability, structural designability and less noncarbon impurities. In particular, the individual graphene microarchitectures preserve a three-dimensional naturally curved surface morphology of original diatom frustules, effectively overcoming the interlayer stacking and hence giving excellent dispersion performance in fabricating solution-processible electrodes. The graphene films derived from as-made graphene powders, compatible with either rod-coating, or inkjet and roll-to-roll printing techniques, exhibit much higher electrical conductivity (~110,700 S m-1 at 80% transmittance) than previously reported solution-based counterparts. This work thus puts forward a practical route for low-cost mass production of various powdery two-dimensional materials.

Nature of fluid flows in differentially heated cylindrical container filled with a stratified solution

NASA Technical Reports Server (NTRS)

Wang, Jai-Ching

1992-01-01

Semiconductor crystals such as Hg(1-x)Cd(x)Te grown by unidirectional solidification Bridgmann method have shown compositional segregations in both the axial and radial directions. Due to the wide separation between the liquidus and the solidus of its pseudobinary phase diagram, there is a diffusion layer of higher HgTe content built up in the melt near the melt-solid interface which gives a solute concentration gradient in the axial direction. Because of the higher thermal conductivity in the melt than that in the crystal there is a thermal leakage through the fused silica crucible wall near the melt-solid interface. This gives a thermal gradient in the radial direction. Hart (1971), Thorpe, Hutt and Soulsby (1969) have shown that under such condition a fluid will become convectively unstable as a result of different diffusivities of temperature and solute. It is quite important to understand the effects of this thermosolute convection on the compositional segregation in the unidirectionally solidified crystals. To reach this goal, we start with a simplified problem. We study the nature of fluid flows of a stratified solution in a cylindrical container with a radial temperature gradient. The cylindrical container wall is considered to be maintained at a higher temperature than that at the center of the solution and the solution in the lower gravitational direction has higher solute concentration which decrease linearly to a lower concentration and then remain constant to the top of the solution. The sample solution is taken to be salt water.

Outcomes of Nature of Science Instruction along a Context Continuum: Preservice Secondary Science Teachers' Conceptions and Instructional Intentions

ERIC Educational Resources Information Center

Bell, Randy L.; Mulvey, Bridget K.; Maeng, Jennifer L.

2016-01-01

This investigation examined outcomes associated with nature of science (NOS) instruction along a science-content context continuum on the development of secondary preservice science teachers' conceptions of and plans to teach NOS, moving beyond the common dichotomy of contextualized versus noncontextualized instruction. Participants comprised six…

Suitability of the first-order mass transfer concept for describing cyclic diffusive mass transfer in stagnant zones

NASA Astrophysics Data System (ADS)

Griffioen, Jasper

1998-10-01

The concept of first-order mass transfer between mobile and immobile regions, which mathematically simplifies the concept of Fickian diffusion in stagnant areas, has often been used to describe physical nonequilibrium transport of solutes into natural porous media. This study compares the two concepts, using analytical expressions describing cyclic mass transfer into and out of stagnant layers. The results show that the first-order mass transfer concept cannot describe continuous diffusion into the immobile zone during period of net outward diffusion if the immobile zone has not filled completely during the period of net inward diffusion. This sets phenomenological limitations to the first-order mass transfer concept when short periods of relative time are involved; these limitations have to be compared with the practical limitations to the Fickian diffusion concept.

An Investigation into How Grade 5 Teachers Teach Natural Science Concepts in Three Western Cape Primary Schools

ERIC Educational Resources Information Center

Set, Beata; Hadman, Joanne; Ashipala, Daniel Opotamutale

2017-01-01

Purpose: The rationale behind this study was to investigate how three Grade 5 Natural Sciences teachers in three Western Cape primary schools teach science concepts so as to enable the researcher to gain a deeper understanding and more insightful perception of the ways in which the pedagogical practices of South African primary school teachers…

Improving Students' Understanding of the Connections between the Concepts of Real-Gas Mixtures, Gas Ideal-Solutions, and Perfect-Gas Mixtures

ERIC Educational Resources Information Center

Privat, Romain; Jaubert, Jean-Noël; Moine, Edouard

2016-01-01

In many textbooks of chemical-engineering thermodynamics, a gas mixture obeying the fundamental law pV[subscript m] = RT is most often called ideal-gas mixture (in some rare cases, the term perfect-gas mixture can be found). These textbooks also define the fundamental concept of ideal solution which in theory, can be applied indifferently to…

A new approach to evaluate natural zeolite ability to sorb lead (Pb) from aqueous solutions

NASA Astrophysics Data System (ADS)

Drosos, Evangelos I. P.; Karapanagioti, Hrissi K.

2013-04-01

Lead (Pb) is a hazardous pollutant commonly found in aquatic ecosystems. Among several methods available, the addition of sorbent amendments to soils or sediments is attractive, since its application is relatively simple, while it can also be cost effective when a low cost and re-usable sorbent is used; e.g. natural zeolites. Zeolites are crystalline aluminosilicates with a three-dimensional structure composed of a set of cavities occupied by large ions and water molecules. Zeolites can accommodate a wide variety of cations, such as Na+, K+, Ca2+, Mg2+, which are rather loosely held and can readily be exchanged for others in an aqueous solution. Natural zeolites are capable of removing cations, such as lead, from aqueous solutions by ion exchange. There is a wide variation in the cation exchange capacity (CEC) of natural zeolites because of the different nature of various zeolites cage structures, natural structural defects, adsorbed ions, and their associated gangue minerals. Naturally occurring zeolites are rarely pure and are contaminated to varying degrees by other minerals, such as clays and feldspars, metals, quartz, or other zeolites as well. These impurities affect the CEC even for samples originated from the same region but from a different source. CEC of the material increases with decreasing impurity content. Potentially exchangeable ions in such impurities do not necessarily participate in ion exchange mechanism, while, in some cases, impurities may additionally block the access to active sites. For zeoliferous rocks having the same percentage of a zeolitic phase, the CEC increases with decreasing Si/Al ratio, as the more Si ions are substituted by Al ions, the more negative the valence of the matrix becomes. Sodium seems to be the most effective exchangeable ion for lead. On the contrary, it is unlikely that the potassium content of the zeolite would be substituted. A pretreatment with high concentration solutions of Na, such as 2 M NaCl, can

Non-uniform solute segregation at semi-coherent metal/oxide interfaces

DOE PAGES

Choudhury, Samrat; Aguiar, Jeffery A.; Fluss, Michael J.; ...

2015-08-26

The properties and performance of metal/oxide nanocomposites are governed by the structure and chemistry of the metal/oxide interfaces. Here we report an integrated theoretical and experimental study examining the role of interfacial structure, particularly misfit dislocations, on solute segregation at a metal/oxide interface. We find that the local oxygen environment, which varies significantly between the misfit dislocations and the coherent terraces, dictates the segregation tendency of solutes to the interface. Depending on the nature of the solute and local oxygen content, segregation to misfit dislocations can change from attraction to repulsion, revealing the complex interplay between chemistry and structure atmore » metal/oxide interfaces. These findings indicate that the solute chemistry at misfit dislocations is controlled by the dislocation density and oxygen content. As a result, fundamental thermodynamic concepts – the Hume-Rothery rules and the Ellingham diagram – qualitatively predict the segregation behavior of solutes to such interfaces, providing design rules for novel interfacial chemistries.« less

Innovative urban forestry governance in Melbourne?: Investigating "green placemaking" as a nature-based solution.

PubMed

Gulsrud, Natalie Marie; Hertzog, Kelly; Shears, Ian

2018-02-01

A nature-based approach to climate resilience aims to challenge and re-frame conventional environmental management methods by refocusing solutions from technological strategies to socio-ecological principles such as human well-being and community-based governance models, thereby improving and legitimizing the delivery of ecosystem services (ES). There are, however, many challenges to applying a socio-ecological agenda to urban climate resilience and thereby re-framing ES delivery as community and people focused, a knowledge gap extensively outlined in the environmental governance literature. In this paper, we aim to contribute to this re-assesment of urban environmental governance by examining the City of Melbourne's approach to urban re-naturing governance from a place-based perspective. Here we focus on the city's internationally-acclaimed urban forest strategy (UFS), investigating how and to which extent the governance arrangements embedded within the UFS draw strength from diverse perspectives and allow for institutional arrangements that support "situated" reflexive decision making and co-creation. We find that Melbourne's UFS governance process fosters green placemaking by re-focusing climate adaptation solutions from technological strategies to situated socio-ecological principles such as human well-being and community-based decision making. In this sense, this case provides valuable insight for the broader UGI governance field regarding the opportunities and challenges associated with a socio-cultural approach to urban re-naturing and ES delivery. Copyright © 2017 Elsevier Inc. All rights reserved.

Challenging the Concept of Natural Distributions: Global Change Turns Trees Into Weeds

NASA Astrophysics Data System (ADS)

Gleadow, R.; O'Leary, B.; Burd, M.

2015-12-01

National parks and nature reserves are set aside to preserve certain ecosystems, reflecting species distributions at a moment in time. Changing climate and fire dynamics can mean that the species most suited to that area are different, leading new tree species to 'invade' the conservation areas. Pittosporum undulatum is an invasive tree native tree species with a natural range from southeast Queensland to Eastern Victoria, Australia. Soon after European settlement this species became a popular ornamental tree in gardens and was planted outside of its natural range across the continent and introduced to the USA (where it is known as Victorian Box), the Hawaiian Islands, Jamaica, southern Africa and the Azores. The reason this is important is because high density of P. undulatum lead to reduced biodiversity and often the complete suppression of regeneration of exiting forest trees. In Australia, changes in fire dynamics have played a major part in its in dominance. New strategies for forest management were proposed by Gleadow an Ashton in the 1980s, but lack of action has led us to predict that the entire Dandenong Ranges, near Melbourne, will be invaded within 25 years resulting in the loss of a major recreational and conservation area. This is a model of the type of problems that can be expected as the climate envelope for species changes in the coming century, challenging the very concept of a "native ".

Growing three-dimensional biomorphic graphene powders using naturally abundant diatomite templates towards high solution processability.

PubMed

Chen, Ke; Li, Cong; Shi, Liurong; Gao, Teng; Song, Xiuju; Bachmatiuk, Alicja; Zou, Zhiyu; Deng, Bing; Ji, Qingqing; Ma, Donglin; Peng, Hailin; Du, Zuliang; Rümmeli, Mark Hermann; Zhang, Yanfeng; Liu, Zhongfan

2016-11-07

Mass production of high-quality graphene with low cost is the footstone for its widespread practical applications. We present herein a self-limited growth approach for producing graphene powders by a small-methane-flow chemical vapour deposition process on naturally abundant and industrially widely used diatomite (biosilica) substrates. Distinct from the chemically exfoliated graphene, thus-produced biomorphic graphene is highly crystallized with atomic layer-thickness controllability, structural designability and less noncarbon impurities. In particular, the individual graphene microarchitectures preserve a three-dimensional naturally curved surface morphology of original diatom frustules, effectively overcoming the interlayer stacking and hence giving excellent dispersion performance in fabricating solution-processible electrodes. The graphene films derived from as-made graphene powders, compatible with either rod-coating, or inkjet and roll-to-roll printing techniques, exhibit much higher electrical conductivity (∼110,700 S m -1 at 80% transmittance) than previously reported solution-based counterparts. This work thus puts forward a practical route for low-cost mass production of various powdery two-dimensional materials.

Growing three-dimensional biomorphic graphene powders using naturally abundant diatomite templates towards high solution processability

PubMed Central

Chen, Ke; Li, Cong; Shi, Liurong; Gao, Teng; Song, Xiuju; Bachmatiuk, Alicja; Zou, Zhiyu; Deng, Bing; Ji, Qingqing; Ma, Donglin; Peng, Hailin; Du, Zuliang; Rümmeli, Mark Hermann; Zhang, Yanfeng; Liu, Zhongfan

2016-01-01

Mass production of high-quality graphene with low cost is the footstone for its widespread practical applications. We present herein a self-limited growth approach for producing graphene powders by a small-methane-flow chemical vapour deposition process on naturally abundant and industrially widely used diatomite (biosilica) substrates. Distinct from the chemically exfoliated graphene, thus-produced biomorphic graphene is highly crystallized with atomic layer-thickness controllability, structural designability and less noncarbon impurities. In particular, the individual graphene microarchitectures preserve a three-dimensional naturally curved surface morphology of original diatom frustules, effectively overcoming the interlayer stacking and hence giving excellent dispersion performance in fabricating solution-processible electrodes. The graphene films derived from as-made graphene powders, compatible with either rod-coating, or inkjet and roll-to-roll printing techniques, exhibit much higher electrical conductivity (∼110,700 S m−1 at 80% transmittance) than previously reported solution-based counterparts. This work thus puts forward a practical route for low-cost mass production of various powdery two-dimensional materials. PMID:27819652

Kinetic concepts to quantify the role of oxidants and photooxidants in natural waters and water treatment

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

Hoigne, J.

1995-12-31

Research performed during the last two decades has led to a significant evolution of reaction kinetic concepts to estimate the role of reactive oxidants and photooxidants in natural waters and for water treatment. Although many reaction-rate data for oxidants such as OH and HO{sub 2}/O{sub 2}{sup -} radicals, O{sub 2} and O{sub 3} or ClO{sub 2} had been compiled before, these were rather selected to elucidate other areas of research and applications. Their critical applications for describing reactions of interest for aqueous chemistry has then required to extend the compilations of rate data: (1) to include more reactions of relevancemore » in aqueous media, (2) to critically account for the aqueous speciations, (3) to experimentally characterise the environmental factors controlling the steady-state concentration of different oxidants, (4) to formulate models useful for computing predictions and allowing for critical experimental tests, and (5) to allow for a unified concept for teaching environmental chemistry that better approaches the concepts of classical chemistry.« less

Translating concepts of complexity to the field of ergonomics.

PubMed

Walker, Guy H; Stanton, Neville A; Salmon, Paul M; Jenkins, Daniel P; Rafferty, Laura

2010-10-01

Since 1958 more than 80 journal papers from the mainstream ergonomics literature have used either the words 'complex' or 'complexity' in their titles. Of those, more than 90% have been published in only the past 20 years. This observation communicates something interesting about the way in which contemporary ergonomics problems are being understood. The study of complexity itself derives from non-linear mathematics but many of its core concepts have found analogies in numerous non-mathematical domains. Set against this cross-disciplinary background, the current paper aims to provide a similar initial mapping to the field of ergonomics. In it, the ergonomics problem space, complexity metrics and powerful concepts such as emergence raise complexity to the status of an important contingency factor in achieving a match between ergonomics problems and ergonomics methods. The concept of relative predictive efficiency is used to illustrate how this match could be achieved in practice. What is clear overall is that a major source of, and solution to, complexity are the humans in systems. Understanding complexity on its own terms offers the potential to leverage disproportionate effects from ergonomics interventions and to tighten up the often loose usage of the term in the titles of ergonomics papers. STATEMENT OF RELEVANCE: This paper reviews and discusses concepts from the study of complexity and maps them to ergonomics problems and methods. It concludes that humans are a major source of and solution to complexity in systems and that complexity is a powerful contingency factor, which should be considered to ensure that ergonomics approaches match the true nature of ergonomics problems.

Advanced control concepts. [trim solution for space shuttle

NASA Technical Reports Server (NTRS)

Hutton, M. F.; Friedland, B.

1973-01-01

The selection of a trim solution that provides the space shuttle with the highest level of performance and dynamic control in the presense of wind disturbances and bias torques due to misalignment of rocket engines is described. It was determined that engine gimballing is insufficient to provide control to trim the vehicle for headwind and sidewind disturbances, and that it is necessary to use aerodynamic surfaces in conjunction with engine gimballing to achieve trim. The algebraic equations for computing the trim solution were derived from the differential equations describing the motion of the vehicle by substituting the desired trim conditions. The general problem of showing how the trim equations are derived from the equations of motion and the mathematical forms of the performance criterion is discussed in detail, along with the general equations for studying the dynamic response of the trim solution.

Assessment of future natural gas vehicle concepts

NASA Astrophysics Data System (ADS)

Groten, B.; Arrigotti, S.

1992-10-01

The development of Natural Gas Vehicles is progressing rapidly under the stimulus of recent vehicle emission regulations. The development is following what can be viewed as a three step progression. In the first step, contemporary gasoline or diesel fueled automobiles are retrofitted with equipment enabling the vehicle to operate on either natural gas or standard liquid fuels. The second step is the development of vehicles which utilize traditional internal combustion engines that have been modified to operate exclusively on natural gas. These dedicated natural gas vehicles operate more efficiently and have lower emissions than the dual fueled vehicles. The third step is the redesigning, from the ground up, of a vehicle aimed at exploiting the advantages of natural gas as an automotive fuel while minimizing its disadvantages. The current report is aimed at identifying the R&D needs in various fuel storage and engine combinations which have potential for providing increased efficiency, reduced emissions, and reductions in vehicle weight and size. Fuel suppliers, automobile and engine manufacturers, many segments of the natural gas and other industries, and regulatory authorities will influence or be affected by the development of such a third generation vehicle, and it is recommended that GRI act to bring these groups together in the near future to begin, developing the focus on a 'designed-for-natural-gas' vehicle.

Use of Natural-Fiber Bio-Composites in Construction versus Traditional Solutions: Operational and Embodied Energy Assessment.

PubMed

Galan-Marin, Carmen; Rivera-Gomez, Carlos; Garcia-Martinez, Antonio

2016-06-13

During the last decades natural polymers have become more and more frequent to replace traditional inorganic stabilizers in building materials. The purpose of this research is to establish a comparison between the most conventional building material solutions for load-bearing walls and a type of biomaterial. This comparison will focus on load-bearing walls as used in a widespread type of twentieth century dwelling construction in Europe and still used in developing countries nowadays. To carry out this analysis, the structural and thermal insulation characteristics of different construction solutions are balanced. The tool used for this evaluation is the life cycle assessment throughout the whole lifespan of these buildings. This research aims to examine the environmental performance of each material assessed: fired clay brick masonry walls (BW), concrete block masonry walls (CW), and stabilized soil block masonry walls (SW) stabilized with natural fibers and alginates. These conventional and new materials are evaluated from the point of view of both operational and embodied energy.

Use of Natural-Fiber Bio-Composites in Construction versus Traditional Solutions: Operational and Embodied Energy Assessment

PubMed Central

Galan-Marin, Carmen; Rivera-Gomez, Carlos; Garcia-Martinez, Antonio

2016-01-01

During the last decades natural polymers have become more and more frequent to replace traditional inorganic stabilizers in building materials. The purpose of this research is to establish a comparison between the most conventional building material solutions for load-bearing walls and a type of biomaterial. This comparison will focus on load-bearing walls as used in a widespread type of twentieth century dwelling construction in Europe and still used in developing countries nowadays. To carry out this analysis, the structural and thermal insulation characteristics of different construction solutions are balanced. The tool used for this evaluation is the life cycle assessment throughout the whole lifespan of these buildings. This research aims to examine the environmental performance of each material assessed: fired clay brick masonry walls (BW), concrete block masonry walls (CW), and stabilized soil block masonry walls (SW) stabilized with natural fibers and alginates. These conventional and new materials are evaluated from the point of view of both operational and embodied energy. PMID:28773586

Sperm selection in natural conception: what can we learn from Mother Nature to improve assisted reproduction outcomes?

PubMed Central

Sakkas, Denny; Ramalingam, Mythili; Garrido, Nicolas; Barratt, Christopher L.R.

2015-01-01

BACKGROUND In natural conception only a few sperm cells reach the ampulla or the site of fertilization. This population is a selected group of cells since only motile cells can pass through cervical mucus and gain initial entry into the female reproductive tract. In animals, some studies indicate that the sperm selected by the reproductive tract and recovered from the uterus and the oviducts have higher fertilization rates but this is not a universal finding. Some species show less discrimination in sperm selection and abnormal sperm do arrive at the oviduct. In contrast, assisted reproductive technologies (ART) utilize a more random sperm population. In this review we contrast the journey of the spermatozoon in vivo and in vitro and discuss this in the context of developing new sperm preparation and selection techniques for ART. METHODS A review of the literature examining characteristics of the spermatozoa selected in vivo is compared with recent developments in in vitro selection and preparation methods. Contrasts and similarities are presented. RESULTS AND CONCLUSIONS New technologies are being developed to aid in the diagnosis, preparation and selection of spermatozoa in ART. To date progress has been frustrating and these methods have provided variable benefits in improving outcomes after ART. It is more likely that examining the mechanisms enforced by nature will provide valuable information in regard to sperm selection and preparation techniques in vitro. Identifying the properties of those spermatozoa which do reach the oviduct will also be important for the development of more effective tests of semen quality. In this review we examine the value of sperm selection to see how much guidance for ART can be gleaned from the natural selection processes in vivo. PMID:26386468

An alkalinizing oral rehydration solution containing lecithin-coated citrus fiber is superior to a nonalkalinizing solution in treating 360 calves with naturally acquired diarrhea.

PubMed

Goodell, G M; Campbell, J; Hoejvang-Nielsen, L; Stansen, W; Constable, P D

2012-11-01

The aim of this field study was to compare the efficacy and cost of 2 commercially available oral rehydration therapy (ORT) solutions in treating dairy calves with naturally acquired diarrhea. A total of 1,349 newborn Holstein-Friesian calves were prospectively enrolled in the study. Calves were housed in individual hutches and fed a mixture of pasteurized hospital milk and an all-milk protein milk replacer twice per day. Calves were monitored twice each day from d 2 of life until 30 d of age for the presence or absence of diarrhea, and were assigned a fecal score and a hydration score at each examination. Calves that developed mild to severe diarrhea that did not need intravenous fluids and did not have clinical evidence of concurrent disease (n = 360) were assigned randomly to receive 1 of 2 commercial ORT solutions: a hypertonic alkalinizing ORT containing lecithin-coated citrus fibers (Diaque, group D, n = 180; Boehringer Ingelheim, Ingelheim, Germany), and an isotonic nonalkalinizing ORT (RE-SORB, group R, n = 180; Pfizer Animal Health, New York, NY) for 2 to 8d; the duration of treatment depended on whether diarrhea was still present. No significant differences were observed in mortality rates or treatment failure rates between the 2 treatment groups. Fecal consistency returned to normal more quickly in group D calves than in group R calves; consequently, group D calves were treated for 1d less than were group R calves. The increase in body weight after 4d of treatment was larger in group D than in group R. The average daily gain from birth to weaning in calves that did not develop concurrent disease (such as pneumonia) during the study period tended to be higher in group D calves (0.53±0.11 kg/d) than in group R calves (0.51±0.09 kg/d). The smaller number of treatments at a lower cost per treatment produced a cost advantage of $4.82 per treated calf in group D calves compared with group R calves. Our findings support the concept that milk should continue

BOOK REVIEW: Critical Phenomena in Natural Sciences: Chaos, Fractals, Selforganization and Disorder: Concepts and Tools

NASA Astrophysics Data System (ADS)

Franz, S.

2004-10-01

Since the discovery of the renormalization group theory in statistical physics, the realm of applications of the concepts of scale invariance and criticality has pervaded several fields of natural and social sciences. This is the leitmotiv of Didier Sornette's book, who in Critical Phenomena in Natural Sciences reviews three decades of developments and applications of the concepts of criticality, scale invariance and power law behaviour from statistical physics, to earthquake prediction, ruptures, plate tectonics, modelling biological and economic systems and so on. This strongly interdisciplinary book addresses students and researchers in disciplines where concepts of criticality and scale invariance are appropriate: mainly geology from which most of the examples are taken, but also engineering, biology, medicine, economics, etc. A good preparation in quantitative science is assumed but the presentation of statistical physics principles, tools and models is self-contained, so that little background in this field is needed. The book is written in a simple informal style encouraging intuitive comprehension rather than stressing formal derivations. Together with the discussion of the main conceptual results of the discipline, great effort is devoted to providing applied scientists with the tools of data analysis and modelling necessary to analyse, understand, make predictions and simulate systems undergoing complex collective behaviour. The book starts from a purely descriptive approach, explaining basic probabilistic and geometrical tools to characterize power law behaviour and scale invariant sets. Probability theory is introduced by a detailed discussion of interpretative issues warning the reader on the use and misuse of probabilistic concepts when the emphasis is on prediction of low probability rare---and often catastrophic---events. Then, concepts that have proved useful in risk evaluation, extreme value statistics, large limit theorems for sums of independent

Biosorption of cadmium (II) from aqueous solutions by natural and modified non-living leaves of Posidonia oceanica.

PubMed

Meseguer, Víctor F; Ortuño, Juan F; Aguilar, M Isabel; Pinzón-Bedoya, Martha L; Lloréns, Mercedes; Sáez, José; Pérez-Marín, Ana B

2016-12-01

Natural, HCl-treated, and formaldehyde-treated non-living leaves of Posidonia oceanica, a marine plant, were investigated as potential biosorbents to remove Cd 2+ from aqueous solutions. The studied biosorbents were characterized by elemental analysis and Fourier transform infrared spectroscopy (FTIR) and it was observed that the adsorption capacity of the biosorbents strongly depended on the pH, increasing as the pH rises. The adsorption process was fast. The adsorption kinetic was analyzed using five kinetic models: pseudo-first order, pseudo-second order, Elovich, intraparticle diffusion, and Bangham models. The adsorption isotherms were analyzed by the Langmuir, Freundlich, Dubinin-Radushkevich, Sips, Redlich-Peterson, and Toth models. The maximum biosorption capacity was attained by the biosorbent treated with HCl (1.11 mmol g -1 ). The distribution equilibrium constant and the Gibbs free energy change were calculated. The effects of the presence of Na + , K + , Mg 2+ , and Ca 2+ ions in the solution on Cd 2+ uptake were studied. Results indicate that non-living leaves of P. oceanica, natural or treated, can be considered as effective and low-cost biosorbents for the removal of cadmium from aqueous solutions.

Isolation of nonvolatile, organic solutes from natural waters by zeotrophic distillation of water from N,N-dimethylformamide

USGS Publications Warehouse

Leenheer, J.A.; Brown, P.A.; Stiles, E.A.

1987-01-01

Nonvolatile, organic solutes that comprise the dissolved organic carbon (DOC) in saline waters were isolated by removal of the water by distillation from a N,N-dimethylformamideformic acid-acetonitrile mixture. Salts isolated with the DOC were removed by crystallization of sodium chloride and sodium sulfate from the solvent mixture, removal of silicic acid by acidification and precipitation, removal of boric acid by methylation and volatilization, and removal of phosphate by zinc acetate precipitation. Chemical alteration of the organic solutes was minimized during evaporative concentration steps by careful control of acid concentrations in the solvent mixture and was minimized during drying by conversion of the samples to pyridinium and sodium salts. Recoveries of various hydrophilic organic standards from aqueous salt solutions and recoveries of natural organic solutes from various water samples varied from 60 to 100%. Losses of organic solutes during the isolation procedure were nonselective and related to the number of salt- and precipitate-washing cycles in the procedure.

Development of a model to predict the adsorption of lead from solution on a natural streambed sediment

USGS Publications Warehouse

Brown, David Wayne; Hem, John David

1984-01-01

Adsorption of solutes by solid mineral surfaces commonly influences the dissolved ionic composition of natural waters. A model based on electrical double-layer theory has been developed which appears to be capable of characterizing the surface chemical behavior of a natural fine-grained sediment containing mostly quartz and feldspar. This variable surface charge-variable surface potential (VSC-VSP) model differs from others in being capable of evaluating more closely the effect of total metal ion activity on the pH-dependent change in electrical potential at the solid surface. The model was tested using 10-4 molar solutions of lead and a silt-size fraction of sediment from the bed of Colma Creek, a small stream in urban northern San Mateo County, California. The average deviation of measured percent adsorption and values calculated from the model was 6.6 adsorption percent from pH 2.0 to pH 7.0.

Preservice Biology Teachers' Conceptions About the Tentative Nature of Theories and Models in Biology

NASA Astrophysics Data System (ADS)

Reinisch, Bianca; Krüger, Dirk

2018-02-01

In research on the nature of science, there is a need to investigate the role and status of different scientific knowledge forms. Theories and models are two of the most important knowledge forms within biology and are the focus of this study. During interviews, preservice biology teachers ( N = 10) were asked about their understanding of theories and models. They were requested to give reasons why they see theories and models as either tentative or certain constructs. Their conceptions were then compared to philosophers' positions (e.g., Popper, Giere). A category system was developed from the qualitative content analysis of the interviews. These categories include 16 conceptions for theories ( n tentative = 11; n certai n = 5) and 18 conceptions for models ( n tentative = 10; n certain = 8). The analysis of the interviews showed that the preservice teachers gave reasons for the tentativeness or certainty of theories and models either due to their understanding of the terms or due to their understanding of the generation or evaluation of theories and models. Therefore, a variety of different terminology, from different sources, should be used in learning-teaching situations. Additionally, an understanding of which processes lead to the generation, evaluation, and refinement or rejection of theories and models should be discussed with preservice teachers. Within philosophy of science, there has been a shift from theories to models. This should be transferred to educational contexts by firstly highlighting the role of models and also their connections to theories.

Conception of the Natural World.

PubMed

Bruno, Andy

2016-09-01

Thoroughly a product of imperial Russia’s aristocratic culture, the mineralogist and geochemist Aleksandr Fersman rose to the top of the country’s scientific establishment after the Bolsheviks took control. He then remained a staunch supporter of various industrial projects through much of the Stalinist period. This essay puts Fersman’s thinking about the natural world in conversation with a quite distinctive mode of intellectual inquiry that developed contemporaneously. Eurasianism was a philosophical doctrine of a group of Russian émigrés who emphasized Russia’s unique status straddling Europe and Asia. While Fersman did not belong to this group of thinkers, a number of his ideas drew on specific experiences in the environments of the Eurasian landmass. Indeed, the article argues that Fersman’s dualistic understanding of nature, his advocacy for the field of geochemistry, his definition of deserts, and a scheme he proposed for industrial operations owed much to the Eurasian settings of the science he practiced. Furthermore, this case of a Eurasian mineralogist illuminates novel aspects of the interplay between national and global sciences.

Changing High School Students' Conceptions of the Nature of Science: The Partnership for Research and Education in Plants (PREP)

ERIC Educational Resources Information Center

Brooks, Eric Dwayne

2011-01-01

This study investigated whether participation in the Partnership for Research and Education in Plants (PREP), a long-term authentic plant research project, in conjunction with explicit verses implicit instruction can change high school students' conceptions of the nature of science (NOS). The participants included a total of 134 students comprised…

Analytic solution of magnetic induction distribution of ideal hollow spherical field sources

NASA Astrophysics Data System (ADS)

Xu, Xiaonong; Lu, Dingwei; Xu, Xibin; Yu, Yang; Gu, Min

2017-12-01

The Halbach type hollow spherical permanent magnet arrays (HSPMA) are volume compacted, energy efficient field sources, and capable of producing multi-Tesla field in the cavity of the array, which have attracted intense interests in many practical applications. Here, we present analytical solutions of magnetic induction to the ideal HSPMA in entire space, outside of array, within the cavity of array, and in the interior of the magnet. We obtain solutions using concept of magnetic charge to solve the Poisson's and Laplace's equations for the HSPMA. Using these analytical field expressions inside the material, a scalar demagnetization function is defined to approximately indicate the regions of magnetization reversal, partial demagnetization, and inverse magnetic saturation. The analytical field solution provides deeper insight into the nature of HSPMA and offer guidance in designing optimized one.

Investigating the Nature of and Methods for Managing Metroplex Operations

NASA Technical Reports Server (NTRS)

Atkins, Stephen; Capozzi, Brian; Hinkey, Jim; Idris, Husni; Kaiser, Kent

2011-01-01

A combination of traffic demand growth, Next Generation Air Transportation System (NextGen) technologies and operational concepts, and increased utilization of regional airports is expected to increase the occurrence and severity of coupling between operations at proximate airports. These metroplex phenomena constrain the efficiency and/or capacity of airport operations and, in NextGen, have the potential to reduce safety and prevent environmental benefits. Without understanding the nature of metroplexes and developing solutions that provide efficient coordination of operations between closely-spaced airports, the use of NextGen technologies and distribution of demand to regional airports may provide little increase in the overall metroplex capacity. However, the characteristics and control of metroplex operations have not received significant study. This project advanced the state of knowledge about metroplexes by completing three objectives: 1. developed a foundational understand of the nature of metroplexes; 2. provided a framework for discussing metroplexes; 3. suggested and studied an approach for optimally managing metroplexes that is consistent with other NextGen concepts

AORN Ergonomic Tool 4: Solutions for Prolonged Standing in Perioperative Settings.

PubMed

Hughes, Nancy L; Nelson, Audrey; Matz, Mary W; Lloyd, John

2011-06-01

Prolonged standing during surgical procedures poses a high risk of causing musculoskeletal disorders, including back, leg, and foot pain, which can be chronic or acute in nature. Ergonomic Tool 4: Solutions for Prolonged Standing in Perioperative Settings provides recommendations for relieving the strain of prolonged standing, including the use of antifatigue mats, supportive footwear, and sit/stand stools, that are based on well-accepted ergonomic safety concepts, current research, and access to new and emerging technology. Published by Elsevier Inc.

Machine learning-based coreference resolution of concepts in clinical documents

PubMed Central

Ware, Henry; Mullett, Charles J; El-Rawas, Oussama

2012-01-01

Objective Coreference resolution of concepts, although a very active area in the natural language processing community, has not yet been widely applied to clinical documents. Accordingly, the 2011 i2b2 competition focusing on this area is a timely and useful challenge. The objective of this research was to collate coreferent chains of concepts from a corpus of clinical documents. These concepts are in the categories of person, problems, treatments, and tests. Design A machine learning approach based on graphical models was employed to cluster coreferent concepts. Features selected were divided into domain independent and domain specific sets. Training was done with the i2b2 provided training set of 489 documents with 6949 chains. Testing was done on 322 documents. Results The learning engine, using the un-weighted average of three different measurement schemes, resulted in an F measure of 0.8423 where no domain specific features were included and 0.8483 where the feature set included both domain independent and domain specific features. Conclusion Our machine learning approach is a promising solution for recognizing coreferent concepts, which in turn is useful for practical applications such as the assembly of problem and medication lists from clinical documents. PMID:22582205

A variational numerical method based on finite elements for the nonlinear solution characteristics of the periodically forced Chen system

NASA Astrophysics Data System (ADS)

Khan, Sabeel M.; Sunny, D. A.; Aqeel, M.

2017-09-01

Nonlinear dynamical systems and their solutions are very sensitive to initial conditions and therefore need to be approximated carefully. In this article, we present and analyze nonlinear solution characteristics of the periodically forced Chen system with the application of a variational method based on the concept of finite time-elements. Our approach is based on the discretization of physical time space into finite elements where each time-element is mapped to a natural time space. The solution of the system is then determined in natural time space using a set of suitable basis functions. The numerical algorithm is presented and implemented to compute and analyze nonlinear behavior at different time-step sizes. The obtained results show an excellent agreement with the classical RK-4 and RK-5 methods. The accuracy and convergence of the method is shown by comparing numerically computed results with the exact solution for a test problem. The presented method has shown a great potential in dealing with the solutions of nonlinear dynamical systems and thus can be utilized in delineating different features and characteristics of their solutions.

Photoproduction of hydrated electrons from natural organic solutes in aquatic environments

USGS Publications Warehouse

Zepp, R.G.; Braun, A.M.; Hoigne, J.; Leenheer, J.A.

1987-01-01

Laser flash photolysis was used to investigate the transients formed on absorption of 355-nm light by dissolved organic matter (DOM) from natural water bodies and from soil. Absorption spectra and quenching studies of the transients provided confirming evidence that hydrated electrons were formed by all of the DOM that were studied. The DOM from the Suwannee River in Georgia and from the Greifensee, a Swiss lake, exhibited great variability in light-absorbing properties. Despite this high variability in absorption coefficients, the primary quantum yields for electron ejection from the Greifensee and Suwannee DOM fell in a narrow range (0.005-0.008). Steady-state irradiations (355 nm) of the DOM with 2-chloroethanol (0.02 M) present as an electron scavenger produced chloride ions with quantum yields that were about 2 orders of magnitude lower than the primary quantum yields. This result indicates that most of the photoejected electrons recombine with cations before escaping into bulk solution. Irradiations of DOM solutions under sunlight (April, latitude 34?? N) photoproduced electrons at rates falling in the range of 0.2-0.4 ??mol/[(mg of DOC) h]. These results indicate that hydrated electrons can play a significant role in the environmental photoreduction of persistent, electronegative pollutants but may be relatively unimportant in the environmental production of hydrogen peroxide. ?? 1987 American Chemical Society.

Using the History of Research on Sickle Cell Anemia to Affect Preservice Teachers' Conceptions of the Nature of Science.

ERIC Educational Resources Information Center

Howe, Eric M.

This paper examines how using a series of lessons developed from the history of research on sickle cell anemia affects preservice teacher conceptions of the nature of science (NOS). The importance of a pedagogy that has students do science through an integral use of the history of science is effective at enriching students' NOS views is presented.…

Changing Preservice Science Teachers' Views of Nature of Science: Why Some Conceptions May Be More Easily Altered than Others

ERIC Educational Resources Information Center

Mesci, Gunkut; Schwartz, Renee' S.

2017-01-01

The purpose of this study was to assess preservice teachers' views of Nature of Science (NOS), identify aspects that were challenging for conceptual change, and explore reasons why. This study particularly focused on why and how some concepts of NOS may be more easily altered than others. Fourteen preservice science teachers enrolled in a NOS and…

Realist Ontology and Natural Processes: A Semantic Tool to Analyze the Presentation of the Osmosis Concept in Science Texts

ERIC Educational Resources Information Center

Spinelli Barria, Michele; Morales, Cecilia; Merino, Cristian; Quiroz, Waldo

2016-01-01

In this work, we developed an ontological tool, based on the scientific realism of Mario Bunge, for the analysis of the presentation of natural processes in science textbooks. This tool was applied to analyze the presentation of the concept of osmosis in 16 chemistry and biology books at different educational levels. The results showed that more…

Removal of phosphate from aqueous solutions and sewage using natural and surface modified coir pith.

PubMed

Krishnan, K Anoop; Haridas, Ajit

2008-04-01

Iron impregnated coir pith (CP-Fe-I) can be effectively used for the removal of phosphate from aqueous streams and sewage. Iron impregnation on natural coir pith was carried out by drop by drop addition method. The effect of various factors such as pH, initial concentration of phosphate, contact time and adsorbent dose on phosphate adsorption was studied by batch technique. The pH at 3.0 favored the maximum adsorption of phosphate from aqueous solutions. The effect of pH on phosphate adsorption was explained by pH(zpc), phosphate speciation in solution and affinity of anions towards the adsorbent sites. A comparative study of the adsorption of phosphate using CP-Fe-I and CP (coir pith) was made and results show that the former one is five to six times more effective than the latter. Kinetic studies revealed that the adsorption process followed a pseudo-second order kinetic model. Adsorption followed Langmuir isotherm model. Column studies were conducted to examine the utility of the investigated adsorbent for the removal of phosphate from continuously flowing aqueous solutions.

Is the calorie concept a real solution to the obesity epidemic?

PubMed Central

Camacho, Salvador; Ruppel, Andreas

2017-01-01

ABSTRACT Background: The obesity epidemic has been growing steadily across the whole world, and so far not a single country has been able to reverse it. The cause of obesity is stated by the World Health Organization as an energy imbalance between calories consumed and calories expended. However, growing evidence suggests that the calorie imbalance concept may not be sufficient to manage and reverse the obesity epidemic. Objective: To discuss the use of the calorie imbalance concept and its elements as a tool for weight management as well as its possible negative consequences and implications for public health, with the aim to point toward the need of an updated concept for causes of obesity. This update should guide public health interventions more efficiently to limit obesity by preventing weight gain or promoting weight loss. Methods: This is a literature reviews based on a semi-structured approach to determine the material to be examined. Results: After revisiting general facts about fat generation and accumulation, we propose an updated concept for the causes of obesity including diet composition and hormonal regulation of fat metabolism. Conclusions: We discuss how this updated concept could benefit the overall efficiency of strategies against obesity, and hypothesize how potential resistance to adopting this new view could be lowered. PMID:28485680

Science teacher’s idea about environmental concepts in science learning as the first step of science teacher training

NASA Astrophysics Data System (ADS)

Tapilouw, M. C.; Firman, H.; Redjeki, S.; Chandra, D. T.

2018-05-01

To refresh natural environmental concepts in science, science teacher have to attend a teacher training. In teacher training, all participant can have a good sharing and discussion with other science teacher. This study is the first step of science teacher training program held by education foundation in Bandung and attended by 20 science teacher from 18 Junior High School. The major aim of this study is gathering science teacher’s idea of environmental concepts. The core of questions used in this study are basic competencies linked with environmental concepts, environmental concepts that difficult to explain, the action to overcome difficulties and references in teaching environmental concepts. There are four major findings in this study. First finding, most environmental concepts are taught in 7th grade. Second finding, most difficult environmental concepts are found in 7th grade. Third finding, there are five actions to overcome difficulties. Fourth finding, science teacher use at least four references in mastering environmental concepts. After all, teacher training can be a solution to reduce difficulties in teaching environmental concepts.

On the meanings of "nature"

Treesearch

Calvin W. Stillman

1977-01-01

All peoples known to science have a concept of "nature" which forms part of the world-view of the culture. The relative importance of "nature" differs among cultures. In our own Western culture, ideas of "nature" are mentioned from the earliest written records, and are related to concepts of the autonomous individual and of hierarachy and...

Naturalness as an Educational Value

ERIC Educational Resources Information Center

Frolund, Sune

2016-01-01

Existentialism and postmodernism have both abandoned the idea of a human nature. Also, the idea of naturalness as a value for education has been targeted as a blind for conservative ideology. There are, however, good reasons to re-establish a sound concept of human naturalness. First of all, the concept does not seem to have disappeared from…

A natural compromise: a moderate solution to the GMO & "natural" labeling disputes.

PubMed

Amaru, Stephanie

2014-01-01

In the United States, genetically modified (GM) foods are labeled no differently from their natural counterparts, leaving consumers with no mechanism for deciphering genetically modified food content. The Food and Drug Administration (FDA) has not formally defined the term "natural," which is frequently used on food labels despite consumer confusion as to what it means. The FDA should initiate a notice and comment rulemaking addressing the narrow issue of whether use of the word "natural" should be permitted oil GM food labels. Prohibition of the use of"natural" on genetically modified foods would mitigate consumer deception regarding genetically modified food content without significantly disadvantaging genetically modified food producers.

Curious Play: Children's Exploration of Nature

ERIC Educational Resources Information Center

Gurholt, Kirsti Pedersen; Sanderud, Jostein Rønning

2016-01-01

This article explores the concept of "curious play" as a theoretical framework to understand and communicate children's experiences of free play in nature. The concept emerged interactively from three sources of inspiration: an ethnographically inspired study of children playing in nature; as a critique of the concept of "risky…

Munazza's story: Understanding science teaching and conceptions of the nature of science in Pakistan through a life history study

NASA Astrophysics Data System (ADS)

Halai, Nelofer

In this study I have described and tried to comprehend how a female science teacher understands her practice. Additionally, I have developed some understanding of her understanding of the nature of science. While teaching science, a teacher projects messages about the nature of science that can be captured by observations and interviews. Furthermore, the manner is which a teacher conceptualizes science for teaching, at least in part, depends on personal life experiences. Hence, I have used the life history method to understand Munazza's practice. Munazza is a young female science teacher working in a private, co-educational school for children from middle income families in Karachi, Pakistan. Her stories are central to the study, and I have represented them using a number of narrative devices. I have woven in my own stories too, to illustrate my perspective as a researcher. The data includes 13 life history interviews and many informal conversations with Munazza, observations of science teaching in classes seven and eight, and interviews with other science teachers and administrative staff of the school. Munazza's personal biography and experiences of school and undergraduate courses has influenced the way she teaches. It has also influenced the way she does not teach. She was not inspired by her science teachers, so she has tried not to teach the way she was taught science. Contextual factors, her conception of preparation for teaching as preparation for subject content and the tension that she faces in balancing care and control in her classroom are some factors that influence her teaching. Munazza believes that science is a stable, superior and value-free way of knowing. In trying to understand the natural world, observations come first, which give reliable information about the world leading inductively to a "theory". Hence, she relies a great deal on demonstrations in the class where students "see" for themselves and abstract the scientific concept from the

Pre-Service Teachers' Developing Conceptions about the Nature and Pedagogy of Mathematical Modeling in the Context of a Mathematical Modeling Course

ERIC Educational Resources Information Center

Cetinkaya, Bulent; Kertil, Mahmut; Erbas, Ayhan Kursat; Korkmaz, Himmet; Alacaci, Cengiz; Cakiroglu, Erdinc

2016-01-01

Adopting a multitiered design-based research perspective, this study examines pre-service secondary mathematics teachers' developing conceptions about (a) the nature of mathematical modeling in simulations of "real life" problem solving, and (b) pedagogical principles and strategies needed to teach mathematics through modeling. Unlike…

Bases of the Mantle-Carbonatite Conception of Diamond Genesis

NASA Astrophysics Data System (ADS)

Litvin, Yuriy; Spivak, Anna; Kuzyura, Anastasia

2016-04-01

In the mantle-carbonatite conception of diamond genesis, the results of physic-chemical experiments are coordinated with the data of analytic mineralogy of primary inclusions in natural diamonds. Generalization of the solutions of principal genetic problems constitutes the bases of the conception. The solutions are following: (1) it is grounded that diamond-parental melts of the upper mantle have peridotite/eclogite - carbonatite - carbon compositions, of the transition zone - (wadsleite↔ringwoodite) - majorite - stishovite - carbonatite - carbon compositions, and of the lower mantle - periclase/wustite - bridgmanite - Ca-perovskite -stishovite - carbonatite - carbon compositions; (2) a construction of generalized diagrams for the diamond-parental media, which reveal changeable compositions of the growth melts of diamonds and associated phases, their genetic relations to the mantle substance, and classification connections of the primary inclusions in natural diamonds; (3) experimental equilibrium phase diagrams of syngenesis of diamonds and primary inclusions, which characterize the nucleation and growth conditions of diamonds and a capture of paragenetic and xenogenetic minerals by the growing diamonds; (4) a determination of the phase diagrams of diamonds and inclusions syngenesis under the regime of fractional crystallization, which discover the regularities of ultrabasic-basic evolution and paragenesis transitions in the diamond-forming systems of the upper and lower mantle. The evidence of the physic-chemically united mode of diamond genesis at the mantle depths with different mineralogy is obtained. References. Litvin Yu.A. (2007). High-pressure mineralogy of diamond genesis. In: Advances in High-Pressure Mineralogy (edited by Eiji Ohtani), Geological Society of America Special paper 421, 83-103. Litvin Yu.A. (2012). Experimental study of physic-chemical conditions of natural diamond formation on an example of the eclogite

Sorption of vanadium (V) onto natural soil colloids under various solution pH and ionic strength conditions.

PubMed

Luo, Xiuhua; Yu, Lin; Wang, Changzhao; Yin, Xianqiang; Mosa, Ahmed; Lv, Jialong; Sun, Huimin

2017-02-01

Batch sorption kinetics and isothermal characteristics of V(V) were investigated on three natural soil colloids (manual loessial soil colloid (MSC), aeolian sandy soil colloid (ASC), and cultivated loessial soil colloid (CSC)) under various solution pH and ionic strength (IS) conditions. Colloids were characterized by atomic force microscopy (AFM), X-ray diffraction (XRD), and fourier transform infrared spectroscopy (FTIR). AFM micrographs showed CSC with an aggregated shape with larger particle diameter as compared with ASC and MSC. XRD spectra revealed the presence of different minerals in natural soil colloids including biotite, kaolinite, calcite and quartz, which might contribute to sorption process. The sorption ability decreased with increase of colloidal particle size. The sorption was mainly attributed to complexation by active carboxylate and alcohol groups of colloidal components. Sorption kinetics and isotherms of V(V) onto natural soil colloids were best fitted with Pseudo-second-order and Freundlich models. Langmuir model indicated that sorption capacity of MSC and ASC was comparable (285.7 and 238.1 mg g -1 ); however, CSC exhibited the lowest sorption capacity (41.5 mg g -1 ) due to its larger particle diameter and aggregated shape. The maximum V(V) sorption capacity reached plateau values at a solution pH ranged between 5.0 and 9.0 for MSC and ASC, and 6.0-8.0 for CSC. Sorption capacity of V(V) onto natural soil colloids decreased with increasing IS. Based on result of this study we can conclude that sorption of V(V) onto natural soil colloids is pH- and IS-dependent. These findings provide insights on the remediation of vanadium-contaminated soils. Copyright © 2016 Elsevier Ltd. All rights reserved.

An Examination of the Documentary Film "Einstein and Eddington" in Terms of Nature of Science Themes, Philosophical Movements, and Concepts

ERIC Educational Resources Information Center

Kapucu, Munise Seçkin

2016-01-01

This study aims to examine nature of science themes, philosophical movements, and overall concepts covered in the documentary film, "Einstein and Eddington". A qualitative research method was used. In this study, the documentary film "Einstein and Eddington," the viewing time of which is 1 hour and 28 minutes, was used as the…

Transport of reacting solutes in porous media: Relation between mathematical nature of problem formulation and chemical nature of reactions

USGS Publications Warehouse

Rubin, Jacob

1983-01-01

Examples involving six broad reaction classes show that the nature of transport-affecting chemistry may have a profound effect on the mathematical character of solute transport problem formulation. Substantive mathematical diversity among such formulations is brought about principally by reaction properties that determine whether (1) the reaction can be regarded as being controlled by local chemical equilibria or whether it must be considered as being controlled by kinetics, (2) the reaction is homogeneous or heterogeneous, (3) the reaction is a surface reaction (adsorption, ion exchange) or one of the reactions of classical chemistry (e.g., precipitation, dissolution, oxidation, reduction, complex formation). These properties, as well as the choice of means to describe them, stipulate, for instance, (1) the type of chemical entities for which a formulation's basic, mass-balance equations should be written; (2) the nature of mathematical transformations needed to change the problem's basic equations into operational ones. These and other influences determine such mathematical features of problem formulations as the nature of the operational transport-equation system (e.g., whether it involves algebraic, partial-differential, or integro-partial-differential simultaneous equations), the type of nonlinearities of such a system, and the character of the boundaries (e.g., whether they are stationary or moving). Exploration of the reasons for the dependence of transport mathematics on transport chemistry suggests that many results of this dependence stem from the basic properties of the reactions' chemical-relation (i.e., equilibrium or rate) equations.

Analytical solutions for combined close-contact and natural convection melting in horizontal cylindrical heat storage capsule

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

Saitoh, T.S.; Hoshi, A.

1998-07-01

Melting and solidification of a phase change material (PCM) in a capsule is of practical importance in latent heat thermal energy storage (LHTES) systems which are considered to be very promising to reduce a peak demand of electricity in the summer season and carbon dioxide (CO{sub 2}) emissions. Two melting modes are involved in melting of capsules. One is close-contact melting between the solid bulk and the capsule wall, and another is natural convection melting in the liquid region. Close-contact melting processes for a single enclosure have been solved using several numerical methods (e.g., Saitoh and Kato (1994)). In additionmore » close-contact melting heat transfer characteristics including melt flow in the liquid film under inner wall temperature distribution were analyzed and simple approximate equations were already presented by Saitoh and Hoshi (1997). The effects of Stefan number and variable temperature profile etc. were clarified in detail. And the melting velocity of the solid bulk under various conditions was also studied theoretically. In addition the effects of variable inner wall temperature on molten mass fraction were investigated. The present paper reports analytical solutions for combined close-contact and natural convection melting in horizontal cylindrical capsule. Moreover, natural convection melting in the liquid region were analyzed in this report. The upper interface shape of the solid bulk is approximated by a circular arc throughout the melting process. For the sake of verification, close-contact melting heat-transfer characteristics including natural convection in the liquid region were studied experimentally. Apparent shift of upper solid-liquid interface is good agreement with the experiment. The present simple approximate solutions will be useful to facilitate designing of the practical capsule bed LHTES systems.« less

Adaptive management of natural resources: theory, concepts, and management institutions.

Treesearch

George H. Stankey; Roger N. Clark; Bernard T. Bormann

2005-01-01

This report reviews the extensive and growing literature on the concept and application of adaptive management. Adaptive management is a central element of the Northwest Forest Plan and there is a need for an informed understanding of the key theories, concepts, and frameworks upon which it is founded. Literature from a diverse range of fields including social learning...

The role of food-security solutions in the protection of natural resources and environment of developing countries.

PubMed

Lashgarara, Farhad; Mirdamadi, Seyyed Mehdi; Hosseini, Seyyed Jamal Farajollah; Chizari, Mohammad

2008-10-01

The majority of the countries of the world, especially developing countries, face environmental problems. Limitations of basic resources (water and soil) and population growth have been the cause of these environmental problems that countries are confronted with. Developing countries have numerous problems, including destruction of forests, vegetable and animal species, and pollution of the environment. Damage to natural resources and the environment can influence the food-security situation. One of the main millennium development goals (MDGs) is protection of the environment and people's health. This cannot obtained unless there is ensured food security. Food security has been defined as a situation when all people, at all times, have physical and economic access to sufficient, safe, and nutritious food needed to maintain a healthy and active life. At the same time, with ensured food security, we can hope to protect the natural resources and environment. The methodology used is descriptive-analytical, and its main purpose is determining the importance and role of food-security solutions in the reduction of environmental hazards and improvement of natural resources and the environmental situation in developing countries. Therefore, some of the most important food-security solutions that can play an important role in this relation were discussed, including conventional research-based technology, biotechnology, information and communication technologies (ICTs), alternative energy sources, and food irradiation.

Nature-based solutions for hydro-meteorological risk reduction and nutrient removal in the Nordic and Arctic regions

NASA Astrophysics Data System (ADS)

Bring, Arvid; Kalantari, Zahra

2017-04-01

Natural ecological functions provide essential and fundamental benefits to mankind, but can also be actively employed in nature-based solutions to specific challenges in society. For example, water-related ecosystem services have a role in such societal benefits as flood protection, erosion control, and excess nutrient removal. Ecosystem services may be produced and consumed in different locations, and research has recently attempted to formalize this discrepancy in identifying service providing areas (SPAs), service benefitting areas (SBAs), and service connecting areas (SCAs). However, in terms of water-related services, there is a lack of formal evaluation of how SPAs, SBAs, and SCAs are related to hydrological measures such as discharge, flood recurrence, excess nutrient removal, etc. We seek to map SPAs, SBAs and SCAs for a number of key ecosystem services in the Nordic and Arctic region though established ecological definitions (typically, based on land use) and evaluate the findings alongside metrics of hydrological connectivity (river networks), provisioning areas (runoff generating areas), and benefitting areas (river stretches where water flow is moderated). We make use of extensive GIS analysis using both high-resolution land cover data and river network maps. In the end, the results are expected to contribute to identifying how water-related ecosystem services can be employed as nature-based solutions for hydro-meteorological risk reduction and nutrient removal in a changing climate in the Nordic and Arctic regions.

Comparative study of As (III) and Zn (II) removal from aqueous solutions using Philippine natural zeolite and alumina

NASA Astrophysics Data System (ADS)

Olegario-Sanchez, Eleanor; Pelicano, Christian Mark

2017-12-01

Herein, the heavy metal removal efficiency of Philippine natural zeolite is investigated through a comparative study with commercial alumina (Al2O3). XRD results revealed a high purity crystalline γ-Al2O3 and a natural zeolite having clinoptilolite (Na,K,Ca)2-3Al3(Al,Si)2Si13O36.12H2O and mordenite (Ca, Na2, K2)Al2Si10O24.7H2O as primary component minerals. Micro-pores and plate-like structures were observed on the surface of the natural zeolite. The natural zeolite has shown three times higher removal efficiency for Zn2+ ion than alumina. On the other hand, alumina exhibited comparable but smaller removal efficiency for As3+ as with that of natural zeolite. Alumina showed a higher capability of increasing the pH of both solutions compared with the natural zeolite. Based on removal efficiency and adsorbent costs, Philippine natural zeolite could be used as a low-cost alternative for wastewater treatment.

An integrated wastewater reuse concept combining natural reclamation techniques, membrane filtration and metal oxide adsorption.

PubMed

Sperlich, A; Zheng, X; Ernst, M; Jekel, M

2008-01-01

In a Sino-German research project, a sustainable water reclamation concept was developed for different applications of municipal water reuse at the Olympic Green 2008 in Beijing, China. Results from pilot-scale experiments in Beijing and Berlin show that selective nutrient removal by adsorption onto granular ferric hydroxide (GFH) after a membrane bioreactor (MBR) can maintain a total phosphorus concentration of <0.03 microg L(-1) P, thus preventing eutrophication of artificial lakes. Operation time of GFH adsorption columns can be extended by regeneration using sodium hydroxide solution. A subsequent ultrafiltration (UF) membrane after bank filtration creates an additional barrier for pathogens and allows for further urban reuse applications such as toilet flushing. Short term bank / bio-filtration prior to UF is shown to effectively remove biopolymers and reduce membrane fouling. Copyright IWA Publishing 2008.

The Feasibility of Teaching Selected Concepts Related to the Particle Nature of Matter to Students in Grades Two Through Six.

ERIC Educational Resources Information Center

Green, Richard Arthur

Reported is a study to determine the feasibility of teaching selected concepts related to the particle nature of matter to students in grades 2-6. The lessons developed for this study did not require a high student reading ability, did not require more than one-half hour of time, included the use of analogous mechanical models whenever possible,…

Children's Conceptions of Air Pressure: Exploring the Nature of Conceptual Change.

ERIC Educational Resources Information Center

Tytler, Russell

1998-01-01

Constructs case studies of individuals to explore the way conceptions change over time, and the difficulties presented by the concept of atmospheric pressure. Evaluates different structural theories of conceptual change. Contains 62 references. (DDR)

Cultivating nature-based solutions: The governance of communal urban gardens in the European Union.

PubMed

van der Jagt, Alexander P N; Szaraz, Luca R; Delshammar, Tim; Cvejić, Rozalija; Santos, Artur; Goodness, Julie; Buijs, Arjen

2017-11-01

In many countries in the European Union (EU), the popularity of communal urban gardening (CUG) on allotments and community gardens is on the rise. Given the role of this practice in increasing urban resilience, most notably social resilience, municipalities in the Global North are promoting CUG as a nature-based solution (NbS). However, the mechanisms by which institutional actors can best support and facilitate CUG are understudied, which could create a gap between aspiration and reality. The aim of this study is therefore to identify what governance arrangements contribute to CUG delivering social resilience. Through the EU GREEN SURGE project, we studied six CUG initiatives from five EU-countries, representing different planning regimes and traditions. We selected cases taking a locally unique or innovative approach to dealing with urban challenges. A variety of actors associated with each of the cases were interviewed to achieve as complete a picture as possible regarding important governance arrangements. A cross-case comparison revealed a range of success factors, varying from clearly formulated objectives and regulations, municipal support, financial resources and social capital through to the availability of local food champions and facilitators engaging in community building. Municipalities can support CUG initiatives by moving beyond a rigid focus on top-down control, while involved citizens can increase the impact of CUG by pursuing political, in addition to hands-on, activities. We conclude that CUG has clear potential to act as a nature-based solution if managed with sensitivity to local dynamics and context. Copyright © 2017 Elsevier Inc. All rights reserved.

A natural macroalgae consortium for biosorption of copper from aqueous solution: Optimization, modeling and design studies.

PubMed

Deniz, Fatih; Ersanli, Elif Tezel

2018-03-21

In this study, the capacity of a natural macroalgae consortium consisting of Chaetomorpha sp., Polysiphonia sp., Ulva sp. and Cystoseira sp. species for the removal of copper ions from aqueous environment was investigated at different operating conditions, such as solution pH, copper ion concentration and contact time. These environmental parameters affecting the biosorption process were optimized on the basis of batch experiments. The experimentally obtained data for the biosorption of copper ions onto the macroalgae-based biosorbent were modeled using the isotherm models of Freundlich, Langmuir, Sips and Dubinin-Radushkevich and the kinetic models of pseudo-first-order, pseudo-second-order, Elovich and Weber and Morris. The pseudo-first-order and Sips equations were the most suitable models to describe the copper biosorption from aqueous solution. The thermodynamic data revealed the feasibility, spontaneity and physical nature of biosorption process. Based on the data of Sips isotherm model, the biosorption capacity of biosorbent for copper ions was calculated as 105.370 mg g -1 under the optimum operating conditions. A single-stage batch biosorption system was developed to predict the real-scale-based copper removal performance of biosorbent. The results of this investigation showed the potential utility of macroalgae consortium for the biosorption of copper ions from aqueous medium.

Protective effect of mannitol, glucose-fructose-sucrose-maltose mixture, and natural honey hyperosmolar solutions against ethanol-induced gastric mucosal damage in rats.

PubMed

Gharzouli, K; Gharzouli, A; Amira, S; Khennouf, S

2001-06-01

We have previously shown that natural honey is able to protect the rat stomach against acute ethanol- and indomethacin-induced lesions. The present investigations were undertaken to examine the role of intraluminal osmolality in this protective effect. Mannitol, glucose-fructose-sucrose-maltose mixture (GFSM) and natural honey (300, 600, 1800 mOsmol/kg water) were given orally to rats 30 min before administration of 70% ethanol for a further 15-min period. Lesions area of the excised stomachs were evaluated. Pylorus-ligated stomachs were filled with mannitol, GFSM mixture and honey (1800 mOsmol/kg water) to test the effect of the hyperosmolar solutions on gastric fluid content and acid secretion. The rate of gastric emptying of the three test solutions (1800 mOsmol/kg) was measured by the phenol red method. Intragastric administration of mannitol, GFSM mixture or honey prevented the formation of mucosal lesions in an osmolality-dependent manner. Using the pylorus-ligated stomach model, the test solutions led to a net increase of luminal fluid volume without affecting acid content. Hyperosmolar solutions presented a delayed gastric emptying if compared to a nonnutrient solution made of carboxymethyl cellulose. The observed results suggest that hyperosmolar solutions can prevent the formation of hemorrhagic lesions by luminal dilution of the necrotising agent and acid, an effect which may be potentiated by a lowered gastric emptying rate.

Natural biosorbents (garlic stem and horse chesnut shell) for removal of chromium(VI) from aqueous solutions.

PubMed

Parlayıcı, Şerife; Pehlivan, Erol

2015-12-01

The biosorption of Cr(VI) by the garlic stem (GS)-Allium sativum L. and horse chesnut shell (HCS)-Aesculus hippocastanum plant residues in a batch type reactor was studied in detail for the purpose of wastewater treatment. The influence of initial Cr(VI) concentration, time, and pH was investigated to optimize Cr(VI) removal from aqueous solutions and equilibrium isotherms and kinetic data. This influence was evaluated. The adsorption capacity of the GS and the HCS for Cr(VI) was determined with the Langmuir and Freundlich isotherm models, and the data was fitted to the Langmuir. The adsorption capacity of the GS and the HCS was found to be 103.09 and 142.85 mg/g of adsorbent from a solution containing 3000 ppm of Cr(VI), respectively. The GS's capacity was considerably lower than that of the HCS in its natural form. Gibbs free energy was spontaneous for all interactions, and the adsorption process exhibited exothermic enthalpy values. The HCS was shown to be a promising biosorbent for Cr(VI) removal from aqueous solutions.

Removal of Copper(II) Ions in Aqueous Solutions Using Tannin-Rich Plants as Natural Bio-Adsorbents

NASA Astrophysics Data System (ADS)

Paksamut, J.; Boonsong, P.

2018-03-01

In this study, the purpose of our interest is to investigatethe adsorption behavior of copper (II) ions in aqueous solution using some tannin-rich plants as natural bio-adsorbents such as mangosteen peels (Garciniamangostana L.), cassava leaves (Manihotesculenta Crantz) and Thai copper pod leaves (Sennasiamea (Lam.)) as powder form in different dosage of adsorbent plant materials.The adsorption capacities at different pH of solution and contact time were performed.All the experiments in this studywere chosen at room temperature by batch technique. From the experimental results showed that cassava leaves gave better adsorbent properties than mangosteen peels and Thai copper pod leaves. The increasing dosage of all adsorbents and contact time have been found to increase adsorption capacities. In this respect, the adsorption capacities depend crucially on the adsorbents and contact time. The optimum pH of copper (II) ions adsorption was pH4. According to this work, it was observed that bioadsorbent materials from tannin-rich plants could be used to remove copper (II) ions from aqueous solutions.

Conceptions of the Nature of Science and Technology: a Study with Children and Youths in a Non-Formal Science and Technology Education Setting

NASA Astrophysics Data System (ADS)

Rocha Fernandes, Geraldo W.; Rodrigues, António M.; Ferreira, Carlos Alberto

2017-05-01

This study investigated some of the aspects that characterise the understanding of the Nature of Science (NOS) and Nature of Technology (NOT) of 20 children and youths from different countries who perform scientific and technological activities in a non-formal teaching and learning setting. Data were collected using a questionnaire and semistructured interviews. A categorical instrument was developed to analyse the participants' conceptions of the following subjects: (1) the role of the scientist, (2) NOS and (3) NOT. The results suggest that the participants had naïve conceptions of NOS that are marked by empirical and technical-instrumental views. They characterised NOT primarily as an instrumental apparatus, an application of knowledge and something important that is part of their lives. They exhibited a stereotypical understanding of the role of the scientist (development of methods, demonstration of facts, relationship with technological devices, etc.).

The protein folds as platonic forms: new support for the pre-Darwinian conception of evolution by natural law.

PubMed

Denton, Michael J; Marshall, Craig J; Legge, Michael

2002-12-07

Before the Darwinian revolution many biologists considered organic forms to be determined by natural law like atoms or crystals and therefore necessary, intrinsic and immutable features of the world order, which will occur throughout the cosmos wherever there is life. The search for the natural determinants of organic form-the celebrated "Laws of Form"-was seen as one of the major tasks of biology. After Darwin, this Platonic conception of form was abandoned and natural selection, not natural law, was increasingly seen to be the main, if not the exclusive, determinant of organic form. However, in the case of one class of very important organic forms-the basic protein folds-advances in protein chemistry since the early 1970s have revealed that they represent a finite set of natural forms, determined by a number of generative constructional rules, like those which govern the formation of atoms or crystals, in which functional adaptations are clearly secondary modifications of primary "givens of physics." The folds are evidently determined by natural law, not natural selection, and are "lawful forms" in the Platonic and pre-Darwinian sense of the word, which are bound to occur everywhere in the universe where the same 20 amino acids are used for their construction. We argue that this is a major discovery which has many important implications regarding the origin of proteins, the origin of life and the fundamental nature of organic form. We speculate that it is unlikely that the folds will prove to be the only case in nature where a set of complex organic forms is determined by natural law, and suggest that natural law may have played a far greater role in the origin and evolution of life than is currently assumed.

RMS Titanic and the emergence of new concepts on consortial nature of microbial events.

PubMed

Cullimore, D Roy; Pellegrino, Charles; Johnston, Lori

2002-01-01

The RMS Titanic sank in 1912 and created a historical event that still ripples through time. Stories were told and lessons learned but the science has only just begun. Today the fading remains of the ship resemble the hanging gardens of Babylon except that it is not plants that drape the walls but complex microbial growths called rusticles. These organisms have been found to be not a species, like plants and animals, but to be structures created by complex communities of bacterial species. Like the discovery of tube worms in the mid-oceanic vents, the nature of these rusticles presents another biological discovery of a fundamental nature. Essentially these microbial consortia on the RMS Titanic have generated structures of a mass that would rival whales and elephants while gradually extracting the iron from the steel. Rusticle-like consortia appear to play many roles within the environment, and it is perhaps the RMS Titanic that is showing that there is a new way to understand the form, function, and nature of microorganisms. This understanding would develop by considering the bacteria not as individual species functioning independently but as consortia of species functioning in community structures within a common habitat. This concept, if adopted, would change dramatically the manner in which a microbial ecologist and any scientist or engineer would view the occurrence of a slime, encrustation, biocolloid, rust flake, iron pan, salt deposit, and perhaps even some of the diseases that remain unexplained as a disease of unknown cause.

The Power of Concept Fields

ERIC Educational Resources Information Center

Stoyanova, Elena

2008-01-01

The ability to discover, explore, describe and mathematise relationships between different concepts is at the heart of scientific work of professional mathematicians and scientists. At school level, however, helping students to link, differentiate or investigate the nature of relationships between mathematics concepts remains in the shadow of…

Interactions Between Mathematics and Physics: The History of the Concept of Function—Teaching with and About Nature of Mathematics

NASA Astrophysics Data System (ADS)

Kjeldsen, Tinne Hoff; Lützen, Jesper

2015-07-01

In this paper, we discuss the history of the concept of function and emphasize in particular how problems in physics have led to essential changes in its definition and application in mathematical practices. Euler defined a function as an analytic expression, whereas Dirichlet defined it as a variable that depends in an arbitrary manner on another variable. The change was required when mathematicians discovered that analytic expressions were not sufficient to represent physical phenomena such as the vibration of a string (Euler) and heat conduction (Fourier and Dirichlet). The introduction of generalized functions or distributions is shown to stem partly from the development of new theories of physics such as electrical engineering and quantum mechanics that led to the use of improper functions such as the delta function that demanded a proper foundation. We argue that the development of student understanding of mathematics and its nature is enhanced by embedding mathematical concepts and theories, within an explicit-reflective framework, into a rich historical context emphasizing its interaction with other disciplines such as physics. Students recognize and become engaged with meta-discursive rules governing mathematics. Mathematics teachers can thereby teach inquiry in mathematics as it occurs in the sciences, as mathematical practice aimed at obtaining new mathematical knowledge. We illustrate such a historical teaching and learning of mathematics within an explicit and reflective framework by two examples of student-directed, problem-oriented project work following the Roskilde Model, in which the connection to physics is explicit and provides a learning space where the nature of mathematics and mathematical practices are linked to natural science.

Solution-mass transfer and grain boundary sliding in mafic shear zones - comparison between experiments and nature

NASA Astrophysics Data System (ADS)

Marti, Sina; Heilbronner, Renée; Stünitz, Holger; Plümper, Oliver; Drury, Martyn

2017-04-01

Grain size sensitive creep (GSSC) mechanisms are widely recognized to be the most efficient deformation mechanisms in shear zones. With or without initial fracturing and fluid infiltration, the onset of heterogeneous nucleation leading to strong grain size reduction is a frequently described process for the initiation of GSSC. Phase mixing due to reaction and heterogeneous nucleation during GSSC impedes grain growth, sustaining small grain sizes as a prerequisite for GSSC. Here we present rock deformation experiments on 'wet' plagioclase - pyroxene mixtures at T=800°C, P=1.0 and 1.5GPa and strain rates of 2e-5 - 2e-6 1/s, performed with a Griggs-type solid medium deformation apparatus. Microstructural criteria are used to show that both, grain boundary sliding (GBS) and solution-mass transfer processes are active and are interpreted to be the dominant strain accommodating processes. Displacement is localized within shear bands formed by fine-grained ( 300 - 500nm) plagioclase (Pl) and the syn-kinematic reaction products amphibole (Amph), quartz (Qz) and zoisite (Zo). We compare our experiments with a natural case - a sheared mafic pegmatite (P-T during deformation 0.7 - 0.9 GPa, 610 - 710 °C; Getsinger et al., 2013) from Northern Norway. Except for the difference in grain size of the experimental and natural samples, microstructures are strikingly alike. The experimental and natural P- and especially T-conditions are very similar. Consequently, extrapolation from experiments to nature must be made without a significant 'temperature-time' trade-off, which is normally taken advantage of when relating experimental to natural strain rates. We will discuss under which assumptions extrapolation to nature in our case is likely feasible. Syn-kinematic reactions during GBS and solution-mass transport are commonly interpreted to result in an ordered (anticlustered) phase mixture. However, phase mixing in our case is restricted: Mixing is extensive between Pl + Zo + Qz and

Thirteen days: Joseph Delboeuf versus Pierre Janet on the nature of hypnotic suggestion.

PubMed

LeBlanc, André

2004-01-01

The problem of post-hypnotic suggestion was introduced in 1884. Give a hypnotic subject the post-hypnotic command to return in 13 days. Awake, the subject remembers nothing yet nonetheless fulfills the command to return. How then does the subject count 13 days without knowing it? In 1886, Pierre Janet proposed the concept of dissociation as a solution, arguing that a second consciousness kept track of time outside of the subject's main consciousness. Joseph Delboeuf, in 1885, and Hippolyte Bernheim, in 1886, proposed an alternative solution, arguing that subjects occasionally drifted into a hypnotic state in which they were reminded of the suggestion. This article traces the development of these competing solutions and describes some of Delboeuf's final reflections on the problem of simulation and the nature of hypnosis. Copyright 2004 Wiley Periodicals, Inc.

An Assessment of Student Knowledge in Fourth, Eighth and Eleventh Grades of Science and Natural Resource Concepts Related to Acidic Deposition.

ERIC Educational Resources Information Center

Brody, Michael; And Others

This study assessed the level of scientific and natural resource knowledge that 4th, 8th, and 11th grade students in Maine possessed concerning acidic deposition. A representative sample of public school students (n=175) was interviewed on 12 concept principles considered critical to a full understanding of the acidic deposition problem. These…

Sustainable Solution for Crude Oil and Natural Gas Separation using Concentrated Solar Power Technology

NASA Astrophysics Data System (ADS)

Choudhary, Piyush; Srivastava, Rakesh K.; Nath Mahendra, Som; Motahhir, Saad

2017-08-01

In today’s scenario to combat with climate change effects, there are a lot of reasons why we all should use renewable energy sources instead of fossil fuels. Solar energy is one of the best options based on features like good for the environment, independent of electricity prices, underutilized land, grid security, sustainable growth, etc. This concept paper is oriented primarily focused on the use of Solar Energy for the crude oil heating purpose besides other many prospective industrial applications to reduce cost, carbon footprint and moving towards a sustainable and ecologically friendly Oil & Gas Industry. Concentrated Solar Power technology based prototype system is proposed to substitute the presently used system based on natural gas burning method. The hybrid system which utilizes the solar energy in the oil and gas industry would strengthen the overall field working conditions, safety measures and environmental ecology. 40% reduction on natural gas with this hybrid system is estimated. A positive implication for an environment, working conditions and safety precautions is the additive advantage. There could also decrease air venting of CO2, CH4 and N2O by an average of 30-35%.

Self-assembly concepts for multicompartment nanostructures

NASA Astrophysics Data System (ADS)

Gröschel, André H.; Müller, Axel H. E.

2015-07-01

Compartmentalization is ubiquitous to many biological and artificial systems, be it for the separate storage of incompatible matter or to isolate transport processes. Advancements in the synthesis of sequential block copolymers offer a variety of tools to replicate natural design principles with tailor-made soft matter for the precise spatial separation of functionalities on multiple length scales. Here, we review recent trends in the self-assembly of amphiphilic block copolymers to multicompartment nanostructures (MCNs) under (semi-)dilute conditions, with special emphasis on ABC triblock terpolymers. The intrinsic immiscibility of connected blocks induces short-range repulsion into discrete nano-domains stabilized by a third, soluble block or molecular additive. Polymer blocks can be synthesized from an arsenal of functional monomers directing self-assembly through packing frustration or response to various fields. The mobility in solution further allows the manipulation of self-assembly processes into specific directions by clever choice of environmental conditions. This review focuses on practical concepts that direct self-assembly into predictable nanostructures, while narrowing particle dispersity with respect to size, shape and internal morphology. The growing understanding of underlying self-assembly mechanisms expands the number of experimental concepts providing the means to target and manipulate progressively complex superstructures.

Solute transport along a single fracture in a porous rock: a simple analytical solution and its extension for modeling velocity dispersion

NASA Astrophysics Data System (ADS)

Liu, Longcheng; Neretnieks, Ivars; Shahkarami, Pirouz; Meng, Shuo; Moreno, Luis

2018-02-01

A simple and robust solution is developed for the problem of solute transport along a single fracture in a porous rock. The solution is referred to as the solution to the single-flow-path model and takes the form of a convolution of two functions. The first function is the probability density function of residence-time distribution of a conservative solute in the fracture-only system as if the rock matrix is impermeable. The second function is the response of the fracture-matrix system to the input source when Fickian-type dispersion is completely neglected; thus, the effects of Fickian-type dispersion and matrix diffusion have been decoupled. It is also found that the solution can be understood in a way in line with the concept of velocity dispersion in fractured rocks. The solution is therefore extended into more general cases to also account for velocity variation between the channels. This leads to a development of the multi-channel model followed by detailed statistical descriptions of channel properties and sensitivity analysis of the model upon changes in the model key parameters. The simulation results obtained by the multi-channel model in this study fairly well agree with what is often observed in field experiments—i.e. the unchanged Peclet number with distance, which cannot be predicted by the classical advection-dispersion equation. In light of the findings from the aforementioned analysis, it is suggested that forced-gradient experiments can result in considerably different estimates of dispersivity compared to what can be found in natural-gradient systems for typical channel widths.

Informational temperature concept and the nature of self-organization

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

Lin, Shu-Kun

1996-12-31

Self-organization phenomena are spontaneous processes. Their behavior should be governed by the second law of thermodynamics. The dissipative structure theory of the Prigogine school of thermodynamics claims that {open_quotes}order out of chaos{close_quotes} through {open_quotes}self-organization{close_quotes} and challenges the validity of the second law of thermodynamics. Unfortunately this theory is questionable. Therefore we have to reconsider the related fundamental theoretical problems. Informational entropy (S) and information (I) are related by S = S{sub max} - I, where S{sub max} is the maximum informational entropy. This conforms with the broadly accepted definition that entropy is the information loss. As informational entropy concept hasmore » been proved to be useful, it will be convenient to define an informational temperature, T{sub I}. This can be related to energy E and the informational entropy S. Information registration is a process of {Delta}I > 0, or {Delta}S < 0, and involves the energetically excited states ({Delta}E > 0). Therefore, T{sub I} is negative, and has the opposite sign of the conventional thermodynamic temperature, T. This concept is useful for clarifying the concepts of {open_quotes}order{close_quotes} and {open_quotes}disorder{close_quotes} of static structures and characterizing many typical information loss processes of self-organization.« less

Multi-pack Disposal Concepts for Spent Fuel (Rev. 0)

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

Hadgu, Teklu; Hardin, Ernest; Matteo, Edward N.

2015-12-01

At the initiation of the Used Fuel Disposition (UFD) R&D campaign, international geologic disposal programs and past work in the U.S. were surveyed to identify viable disposal concepts for crystalline, clay/shale, and salt host media (Hardin et al., 2012). Concepts for disposal of commercial spent nuclear fuel (SNF) and high-level waste (HLW) from reprocessing are relatively advanced in countries such as Finland, France, and Sweden. The UFD work quickly showed that these international concepts are all “enclosed,” whereby waste packages are emplaced in direct or close contact with natural or engineered materials . Alternative “open” modes (emplacement tunnels are keptmore » open after emplacement for extended ventilation) have been limited to the Yucca Mountain License Application Design (CRWMS M&O, 1999). Thermal analysis showed that, if “enclosed” concepts are constrained by peak package/buffer temperature, waste package capacity is limited to 4 PWR assemblies (or 9-BWR) in all media except salt. This information motivated separate studies: 1) extend the peak temperature tolerance of backfill materials, which is ongoing; and 2) develop small canisters (up to 4-PWR size) that can be grouped in larger multi-pack units for convenience of storage, transportation, and possibly disposal (should the disposal concept permit larger packages). A recent result from the second line of investigation is the Task Order 18 report: Generic Design for Small Standardized Transportation, Aging and Disposal Canister Systems (EnergySolution, 2015). This report identifies disposal concepts for the small canisters (4-PWR size) drawing heavily on previous work, and for the multi-pack (16-PWR or 36-BWR).« less

Feasibility of Topical Applications of Natural High-Concentration Capsaicinoid Solutions in Patients with Peripheral Neuropathic Pain: A Retrospective Analysis.

PubMed

Bauchy, Fanny; Mouraux, Andre; Deumens, Ronald; Leerink, Marjolein; Ulpiano Trillig, Antonio; le Polain de Waroux, Bernard; Steyaert, Arnaud; Joëlle, Quetin-Leclercq; Forget, Patrice

2016-01-01

Background. Capsaicin, one of several capsaicinoid compounds, is a potent TRPV1 agonist. Topical application at high concentration (high concentration, >1%) induces a reversible disappearance of epidermal free nerve endings and is used to treat peripheral neuropathic pain (PNP). While the benefit of low-concentration capsaicin remains controversial, the 8%-capsaicin patch (Qutenza®, 2010, Astellas, Netherlands) has shown its effectiveness. This patch is, however, costly and natural high-concentration capsaicinoid solutions may represent a cheaper alternative to pure capsaicin. Methods. In this retrospective study, 149 patients were screened, 132 were included with a diagnosis of neuropathic pain, and eighty-four were retained in the final analyses (median age: 57.5 years [IQR25-75: 44.7-67.1], male/female: 30/54) with PNP who were treated with topical applications of natural high-concentration capsaicinoid solutions (total number of applications: 137). Indications were postsurgical PNP (85.7%) and nonsurgical PNP (14.3%) (posttraumatic, HIV-related, postherpetic, and radicular PNP). Objectives. To assess the feasibility of topical applications of natural high-concentration capsaicinoid solutions for the treatment of PNP. Results. The median treated area was 250 cm 2 [IQR25-75: 144-531]. The median amount of capsaicinoids was 55.1 mg [IQR25-75: 28.7-76.5] per plaster and the median concentration was 172.3  μ g/cm 2 [IQR25-75: 127.6-255.2]. Most patients had local adverse effects on the day of treatment, such as mild to moderate burning pain and erythema. 13.6-19.4% of the patients experienced severe pain or erythema. Following treatment, 62.5% of patients reported a lower pain intensity or a smaller pain surface, and 35% reported a sustained pain relief lasting for at least 4 weeks. Conclusion. Analgesic topical treatment with natural high-concentration capsaicinoid is feasible and may represent a low cost alternative to alleviate PNP in clinical practice.

Feasibility of Topical Applications of Natural High-Concentration Capsaicinoid Solutions in Patients with Peripheral Neuropathic Pain: A Retrospective Analysis

PubMed Central

Mouraux, Andre; Deumens, Ronald; Leerink, Marjolein; le Polain de Waroux, Bernard; Joëlle, Quetin-Leclercq

2016-01-01

Background. Capsaicin, one of several capsaicinoid compounds, is a potent TRPV1 agonist. Topical application at high concentration (high concentration, >1%) induces a reversible disappearance of epidermal free nerve endings and is used to treat peripheral neuropathic pain (PNP). While the benefit of low-concentration capsaicin remains controversial, the 8%-capsaicin patch (Qutenza®, 2010, Astellas, Netherlands) has shown its effectiveness. This patch is, however, costly and natural high-concentration capsaicinoid solutions may represent a cheaper alternative to pure capsaicin. Methods. In this retrospective study, 149 patients were screened, 132 were included with a diagnosis of neuropathic pain, and eighty-four were retained in the final analyses (median age: 57.5 years [IQR25–75: 44.7–67.1], male/female: 30/54) with PNP who were treated with topical applications of natural high-concentration capsaicinoid solutions (total number of applications: 137). Indications were postsurgical PNP (85.7%) and nonsurgical PNP (14.3%) (posttraumatic, HIV-related, postherpetic, and radicular PNP). Objectives. To assess the feasibility of topical applications of natural high-concentration capsaicinoid solutions for the treatment of PNP. Results. The median treated area was 250 cm2 [IQR25–75: 144–531]. The median amount of capsaicinoids was 55.1 mg [IQR25–75: 28.7–76.5] per plaster and the median concentration was 172.3 μg/cm2 [IQR25–75: 127.6–255.2]. Most patients had local adverse effects on the day of treatment, such as mild to moderate burning pain and erythema. 13.6–19.4% of the patients experienced severe pain or erythema. Following treatment, 62.5% of patients reported a lower pain intensity or a smaller pain surface, and 35% reported a sustained pain relief lasting for at least 4 weeks. Conclusion. Analgesic topical treatment with natural high-concentration capsaicinoid is feasible and may represent a low cost alternative to alleviate PNP in

Teaching Health in a Natural History Museum.

ERIC Educational Resources Information Center

Newman, Ian M.

The opportunities offered by a natural history museum to enhance and expand classroom instruction in health are discussed. A basic constellation of typical natural history museum exhibit concepts and an array of health-related opportunities that are easily developed around these displays is outlined. The natural history concept provides an…

Possible Concepts for Waterproofing of Norwegian TBM Railway Tunnels

NASA Astrophysics Data System (ADS)

Dammyr, Øyvind; Nilsen, Bjørn; Thuro, Kurosch; Grøndal, Jørn

2014-05-01

The aim of this paper is to evaluate and compare the durability, life expectancy and maintenance needs of traditional Norwegian waterproofing concepts to the generally more rigid waterproofing concepts seen in other European countries. The focus will be on solutions for future Norwegian tunnel boring machine railway tunnels. Experiences from operation of newer and older tunnels with different waterproofing concepts have been gathered and analyzed. In the light of functional requirements for Norwegian rail tunnels, some preliminary conclusions about suitable concepts are drawn. Norwegian concepts such as polyethylene panels and lightweight concrete segments with membrane are ruled out. European concepts involving double shell draining systems (inner shell of cast concrete with membrane) and single shell undrained systems (waterproof concrete segments) are generally evaluated as favorable. Sprayable membranes and waterproof/insulating shotcrete are welcomed innovations, but more research is needed to verify their reliability and cost effectiveness compared to the typical European concepts. Increasing traffic and reliance on public transport systems in Norway result in high demand for durable and cost effective solutions.

Ammonium removal from aqueous solutions by using natural Chinese (Chende) zeolite as adsorbent.

PubMed

Huang, Haiming; Xiao, Xianming; Yan, Bo; Yang, Liping

2010-03-15

This paper presents a study of the removal of ammonium ion from aqueous solutions using natural Chinese (Chende) zeolite. A series of experiments was conducted to examine the effects of solution pH, particle size, contact time, adsorbent dosage, and the presence of other cation- and anion species on ammonium removal. The findings indicated that these parameters named had a significant effect on the removal of ammonium by the zeolite. The effect of other cations on the removal of ammonium followed the order of preference Na(+)>K(+)>Ca(2+)>Mg(2+) at identical mass concentrations, and the effect of the presence of individual anions followed the order of preference carbonate>chloride>sulfate>phosphate at identical mass concentrations of ammonium ions. Kinetic analysis showed that the adsorption of ammonium on zeolite at different ranges of particle size well followed the pseudo-second-order model and followed the intra-particle diffusion model only during the initial 60 min of the adsorption process. Equilibrium isotherm data was fitted to the linear Langmuir- and Freundlich models with the latter model providing the better description of the process (R(2)=0.991-0.997) compared to the former (R(2)=0.902-0.989). (c) 2009 Elsevier B.V. All rights reserved.

Solving Solutions: Exploring Unknowns through Chemistry.

ERIC Educational Resources Information Center

Burns, John; Yoshina, Granville; Goodding, Debbie; Streitberger, Eric

2000-01-01

Presents a chemistry activity that introduces students to one type of chemical bond by developing the integer operation concept of zero pairs. Leads to an activity of combining drops of 0.3 molar solutions to form six different colored precipitates from five solutions. (ASK)

RELATIONSHIP BETWEEN LEVELS OF MATURITY AND LEVELS OF UNDERSTANDING OF SELECTED CONCEPTS OF THE PARTICLE NATURE OF MATTER. TECHNICAL REPORT NO. 36.

ERIC Educational Resources Information Center

CAREY, RUSSELL L.

INVESTIGATED WERE THE LEVELS OF UNDERSTANDING OF SELECTED CONCEPTS CONCERNING THE PARTICLE NATURE OF MATTER AND THE RELATIONSHIP OF THE STUDENTS' MATURITY AND CONCEPTUAL UNDERSTANDING. THE STUDENTS SAMPLED WERE OF HIGH AND AVERAGE IQ, AND IN GRADES 2-5. ALL GROUPS RECEIVED COMPARABLE INSTRUCTION. USED WERE ALTERNATE RESPONSE TAXONOMY-TYPE…

Sensory motor systems of artificial and natural hands.

PubMed

Chappell, Paul H; Cranny, Andy; Cotton, Darryl P J; White, Neil M; Beeby, Steve P

2007-12-01

The surgeon Ambroise Paré designed an anthropomorphic hand for wounded soldiers in the 16th century. Since that time, there have been advances in technology through the use of computer-aided design, modern materials, electronic controllers and sensors to realise artificial hands which have good functionality and reliability. Data from touch, object slip, finger position and temperature sensors, mounted in the fingers and on the palm, can be used in feedback loops to automatically hold objects. A study of the natural neuromuscular systems reveals a complexity which can only in part be realised today with technology. Highlights of the parallels and differences between natural and artificial hands are discussed with reference to the Southampton Hand. The anatomical structure of parts of the natural systems can be made artificially such as the antagonist muscles using tendons. Theses solutions look promising as they are based on the natural form but in practice lack the desired physical specification. However, concepts of the lower spinal loops can be mimicked in principle. Some future devices will require greater skills from the surgeon to create the interface between the natural system and an artificial device. Such developments may offer a more natural control with ease of use for the limb deficient person.

Natural knowledge as a propaedeutic to self-betterment: Francis Bacon and the transformation of natural history.

PubMed

Lancaster, James A T

2012-01-01

This paper establishes the 'emblematic' use of natural history as a propaedeutic to self-betterment in the Renaissance; in particular, in the natural histories of Gessner and Topsell, but also in the works of Erasmus and Rabelais. Subsequently, it investigates how Francis Bacon's conception of natural history is envisaged in relation to them. The paper contends that, where humanist natural historians understood the use of natural knowledge as a preliminary to individual improvement, Bacon conceived self-betterment foremost as a means to Christian charity, or social-betterment. It thus examines the transformation of the moralizing aspect of Renaissance natural history in Bacon's conception of his Great Instauration.

The Mole Concept

ERIC Educational Resources Information Center

Duncan, I. M.; Johnstone, A. H.

1973-01-01

Reports a study of difficulties encountered by 14.5- to 15.0- year-old children in learning the mole concept with a programed instruction. Concludes that three respective disturbing factors were embedded in manipulation of molarity of solutions, balancing equations, and misapprehension that one mole of a compound always reacts with one mole of…

An organismal concept for Sengelia radicans gen. et sp. nov. – morphology and natural history of an Early Devonian lycophyte

PubMed Central

Tomescu, Alexandru M. F.

2017-01-01

Abstract Background and Aims Fossil plants are found as fragmentary remains and understanding them as natural species requires assembly of whole-organism concepts that integrate different plant parts. Such concepts are essential for incorporating fossils in hypotheses of plant evolution and phylogeny. Plants of the Early Devonian are crucial to reconstructing the initial radiation of tracheophytes, yet few are understood as whole organisms. Methods This study assembles a whole-plant concept for the Early Devonian lycophyte Sengelia radicans gen. et sp. nov., based on morphometric data and taphonomic observations from >1000 specimens collected in the Beartooth Butte Formation (Wyoming, USA). Key Results Sengelia radicans occupies a key position between stem-group and derived lycophyte lineages. Sengelia had a rooting system of downward-growing root-bearing stems, formed dense monotypic mats of prostrate shoots in areas that experienced periodic flooding, and was characterized by a life-history strategy adapted for survival after floods, dominated by clonality, and featuring infrequent sexual reproduction. Conclusions Sengelia radicans is the oldest among the very few early tracheophytes for which a detailed, rigorous whole-plant concept integrates morphology, growth habit, life history and growth environment. This plant adds to the diversity of body plans documented among lycophytes and may help elucidate patterns of morphological evolution in the clade. PMID:28334100

Radiation effects on bifurcation and dual solutions in transient natural convection in a horizontal annulus

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

Luo, Kang; Yi, Hong-Liang, E-mail: yihongliang@hit.edu.cn; Tan, He-Ping, E-mail: tanheping@hit.edu.cn

2014-05-15

Transitions and bifurcations of transient natural convection in a horizontal annulus with radiatively participating medium are numerically investigated using the coupled lattice Boltzmann and direct collocation meshless (LB-DCM) method. As a hybrid approach based on a common multi-scale Boltzmann-type model, the LB-DCM scheme is easy to implement and has an excellent flexibility in dealing with the irregular geometries. Separate particle distribution functions in the LBM are used to calculate the density field, the velocity field and the thermal field. In the radiatively participating medium, the contribution of thermal radiation to natural convection must be taken into account, and it ismore » considered as a radiative term in the energy equation that is solved by the meshless method with moving least-squares (MLS) approximation. The occurrence of various instabilities and bifurcative phenomena is analyzed for different Rayleigh number Ra and Prandtl number Pr with and without radiation. Then, bifurcation diagrams and dual solutions are presented for relevant radiative parameters, such as convection-radiation parameter Rc and optical thickness τ. Numerical results show that the presence of volumetric radiation changes the static temperature gradient of the fluid, and generally results in an increase in the flow critical value. Besides, the existence and development of dual solutions of transient convection in the presence of radiation are greatly affected by radiative parameters. Finally, the advantage of LB-DCM combination is discussed, and the potential benefits of applying the LB-DCM method to multi-field coupling problems are demonstrated.« less

Concentration Dependence of Solution Shear Viscosity and Solute Mass Diffusivity in Crystal Growth from Solutions

NASA Technical Reports Server (NTRS)

Izmailov, Alexander F.; Myerson, Allan S.

1995-01-01

The physical properties of a supersaturated binary solution such as its density rho, shear viscosity eta, and solute mass diffusivity D are dependent on the solute concentration c: rho = rho(c), eta = eta(c), and D = D(c). The diffusion boundary layer equations related to crystal growth from solution are derived for the case of natural convection with a solution density, a shear viscosity, and a solute diffusivity that are all depen- dent on solute concentration. The solution of these equations has demonstrated the following. (1) At the vicinity of the saturation concentration c(sub s) the solution shear viscosity eta depends on rho as eta(sub s) = eta(rho(sub s))varies as square root of rho(c(sub s)). This theoretically derived result has been verified in experiments with several aqueous solutions of inorganic and organic salts. (2) The maximum solute mass transfer towards the growing crystal surface can be achieved for values of c where the ratio of d ln(D(c)/dc) to d ln(eta(c)/dc) is a maximum.

Lack of latex allergen contamination of solutions withdrawn from vials with natural rubber stoppers.

PubMed

Thomsen, D J; Burke, T G

2000-01-01

The effect on latex allergen contamination and microbial growth of a latex-allergy precaution technique for preparing injectable products was studied. The study consisted of three parts: (1) preparation of 20 samples from vials with latex-containing stoppers in accordance with conventional guidelines, (2) preparation of 20 samples in accordance with latex-allergy precaution guidelines, and (3) preparation of 5 latex-free samples and 1 latex-contaminated sample as negative and positive controls, respectively. The conventional method involved swabbing a vial top with an alcohol prep pad, puncturing the dry natural rubber stopper with an 18-gauge needle attached to a latex-free syringe, and withdrawing the contents of the vial into the syringe. The latex-allergy precaution preparation technique was similar, except that the stopper was removed before the vial contents were withdrawn. There was essentially no difference in latex allergen concentrations between the two drug preparation methods. None of the samples prepared with the standard method supported any microbial growth. One sample prepared with the latex-allergy precaution method grew bacteria. Removal of the dry rubber stopper from vials did not yield solutions with less latex allergen than solutions prepared according to conventional guidelines.

Temporal naturalism

NASA Astrophysics Data System (ADS)

Smolin, Lee

2015-11-01

Two people may claim both to be naturalists, but have divergent conceptions of basic elements of the natural world which lead them to mean different things when they talk about laws of nature, or states, or the role of mathematics in physics. These disagreements do not much affect the ordinary practice of science which is about small subsystems of the universe, described or explained against a background, idealized to be fixed. But these issues become crucial when we consider including the whole universe within our system, for then there is no fixed background to reference observables to. I argue here that the key issue responsible for divergent versions of naturalism and divergent approaches to cosmology is the conception of time. One version, which I call temporal naturalism, holds that time, in the sense of the succession of present moments, is real, and that laws of nature evolve in that time. This is contrasted with timeless naturalism, which holds that laws are immutable and the present moment and its passage are illusions. I argue that temporal naturalism is empirically more adequate than the alternatives, because it offers testable explanations for puzzles its rivals cannot address, and is likely a better basis for solving major puzzles that presently face cosmology and physics. This essay also addresses the problem of qualia and experience within naturalism and argues that only temporal naturalism can make a place for qualia as intrinsic qualities of matter.

[Concepts of rational taxonomy].

PubMed

Pavlinov, I Ia

2011-01-01

The problems are discussed related to development of concepts of rational taxonomy and rational classifications (taxonomic systems) in biology. Rational taxonomy is based on the assumption that the key characteristic of rationality is deductive inference of certain partial judgments about reality under study from other judgments taken as more general and a priory true. Respectively, two forms of rationality are discriminated--ontological and epistemological ones. The former implies inference of classifications properties from general (essential) properties of the reality being investigated. The latter implies inference of the partial rules of judgments about classifications from more general (formal) rules. The following principal concepts of ontologically rational biological taxonomy are considered: "crystallographic" approach, inference of the orderliness of organismal diversity from general laws of Nature, inference of the above orderliness from the orderliness of ontogenetic development programs, based on the concept of natural kind and Cassirer's series theory, based on the systemic concept, based on the idea of periodic systems. Various concepts of ontologically rational taxonomy can be generalized by an idea of the causal taxonomy, according to which any biologically sound classification is founded on a contentwise model of biological diversity that includes explicit indication of general causes responsible for that diversity. It is asserted that each category of general causation and respective background model may serve as a basis for a particular ontologically rational taxonomy as a distinctive research program. Concepts of epistemologically rational taxonomy and classifications (taxonomic systems) can be interpreted in terms of application of certain epistemological criteria of substantiation of scientific status of taxonomy in general and of taxonomic systems in particular. These concepts include: consideration of taxonomy consistency from the

Study of colloidal properties of natural and Al-pillared smectite and removal of copper ions from an aqueous solution.

PubMed

Sartor, Lucas Resmini; de Azevedo, Antonio Carlos; Andrade, Gabriel Ramatis Pugliese

2015-01-01

In this study, an Al-pillared smectite was synthesized and changes in its colloidal properties were investigated. The pillaring solution was prepared by mixing 0.4 mol L(-1) NaOH and 0.2 mol L(-1) AlCl3.6H2O solutions. Intercalated clays were heated to obtain the pillared clay, and X-ray diffractometry (XRD), X-ray fluorescence (XRF), Fourier transform infrared (FTIR) spectroscopy and N2 sorption/desorption isotherms analysis were done to characterize the changes in clay properties. Moreover, adsorption experiments were carried out in order to evaluate the capacity of the pillared clays to remove Cu2+ from an aqueous solution and to characterize the interaction between adsorbent and adsorbate. The results indicate that the natural clay has a basal spacing of 1.26 nm, whereas the pillared clays reached 1.78 nm (500°C) and 1.80 nm (350°C) after calcination. XRF analysis revealed an increase in the Al3+ in the pillared clay as compared to the natural clay. The surface area and pore volume (micro and mesoporous) were higher for the pillared clays. Experimental data from the adsorption experiment were fit to Langmuir and Freundlich and Temkin adsorption models, and the former one was the best fit (highest r2 value) for all the clays and lower standard deviation (Δg%) for the natural clay. On the other hand, the Temkin model exhibited Δg% value lower for the pillared clays. Thermodynamics parameters demonstrate that the Cu2+ adsorption process is spontaneous for all the clays, but with higher values for the pillared materials. In addition, application of the Dubinin-Radushkevich model revealed that the bond between the metal and the clay are weak, characterizing a physisorption.

Elucidating elementary science teachers' conceptions of the nature of science: A view to beliefs about both science and teaching

NASA Astrophysics Data System (ADS)

Keske, Kristina Palmer

The purpose of this interpretive case study was to elucidate the conceptions of the nature of science held by seven elementary science teachers. The constructivist paradigm provided the philosophical and methodological foundation for the study. Interviews were employed to collect data from the participants about their formal and informal experiences with science. In addition, the participants contributed their perspectives on four aspects of the nature of science: what is science; who is a scientist; what are the methods of science; and how is scientific knowledge constructed. Data analysis not only revealed these teachers' views of science, but also provided insights into how they viewed science teaching. Four themes emerged from the data. The first theme developed around the participants' portrayals of the content of science, with participant views falling on a continuum of limited to universal application of science as procedure. The second theme dealt with the participants' views of the absolute nature of scientific knowledge. Participants' perceptions of the tentative nature of science teaching provided the basis for the third theme concerning the need for absolutes in practice. The fourth theme drew parallels between participants' views of science and science teaching, with two participants demonstrating a consistency in beliefs about knowledge construction across contexts. This study revealed both personal and contextual factors which impacted how the participants saw science and science teaching. Many of the participants' memories of formal science revolved around the memorization of content and were viewed negatively. All the participants had limited formal training in science. Of the seven participants, only two had chosen to be science teachers at the beginning of their careers. The participants' limited formal experiences with science provided little time for exploration into historical, philosophical, and sociological studies of science, a necessary

A qualitative study of high school students' pre- and post-instructional conceptions in acid-base chemistry

NASA Astrophysics Data System (ADS)

Sheppard, Keith

This study investigated high school students' understanding of acid-base chemistry, prior to and after formal chemistry instruction. Sixteen students enrolled in a regular chemistry course were interviewed three times during the school year; before and after studying the topic of acids and bases and then while conducting a titration using a microcomputer-based laboratory (MBL). Oral, pictorial and graphical data were collected in a variety of acid-base practical tasks. The data were analyzed in two parts; first, common themes, ideas and alternative conceptions that students held were identified; second, profiles of each students were made to determine changes in their conceptions due to instruction. The findings showed that students had considerable difficulty with several areas of acid-base chemistry and did not develop an integrated conceptual understanding of the topic. Students were unable to describe acid-base concepts accurately and revealed a number of alternative conceptions, which remained unchanged by instruction. Specific areas of difficulty included the concepts of pH, neutralization, strength and the theoretical descriptions of acids and bases. Further, most students could not relate the concepts to actual solutions and were unable to describe acid-base phenomena at a sub-microscopic level. Student difficulties stemmed from a lack of understanding of some underlying and fundamental chemistry, such as the nature of chemical change and the particulate nature of matter. A number of factors were identified as contributing to these difficulties, and included the overstuffed nature of introductory chemistry itself, the emphasis in instruction on solving numerical problems and the dominant role played by the textbook. Further, the conceptual density of acid-base chemistry, the confusing nature of acid-base terminology and the lack of agreement about what material should be included in the chemistry curriculum were viewed as problematic. The study calls for a

Asymptotic proportionality (weak ergodicity) and conditional asymptotic equality of solutions to time-heterogeneous sublinear difference and differential equations

NASA Astrophysics Data System (ADS)

Thieme, Horst R.

The concept of asymptotic proportionality and conditional asymptotic equality which is presented here aims at making global asymptotic stability statements for time-heterogeneous difference and differential equations. For such non-autonomous problems (apart from special cases) no prominent special solutions (equilibra, periodic solutions) exist which are natural candidates for the asymptotic behaviour of arbitrary solutions. One way out of this dilemma consists in looking for conditions under which any two solutions to the problem (with different initial conditions) behave in a similar or even the same way as time tends to infinity. We study a general sublinear difference equation in an ordered Banach space and, for illustration, time-heterogeneous versions of several well-known differential equations modelling the spread of gonorrhea in a heterogeneous population, the spread of a vector-borne infectious disease, and the dynamics of a logistically growing spatially diffusing population.

Applying the dark diversity concept to nature conservation.

PubMed

Lewis, Rob J; de Bello, Francesco; Bennett, Jonathan A; Fibich, Pavel; Finerty, Genevieve E; Götzenberger, Lars; Hiiesalu, Inga; Kasari, Liis; Lepš, Jan; Májeková, Maria; Mudrák, Ondřej; Riibak, Kersti; Ronk, Argo; Rychtecká, Terezie; Vitová, Alena; Pärtel, Meelis

2017-02-01

Linking diversity to biological processes is central for developing informed and effective conservation decisions. Unfortunately, observable patterns provide only a proportion of the information necessary for fully understanding the mechanisms and processes acting on a particular population or community. We suggest conservation managers use the often overlooked information relative to species absences and pay particular attention to dark diversity (i.e., a set of species that are absent from a site but that could disperse to and establish there, in other words, the absent portion of a habitat-specific species pool). Together with existing ecological metrics, concepts, and conservation tools, dark diversity can be used to complement and further develop conservation prioritization and management decisions through an understanding of biodiversity relativized by its potential (i.e., its species pool). Furthermore, through a detailed understanding of the population, community, and functional dark diversity, the restoration potential of degraded habitats can be more rigorously assessed and so to the likelihood of successful species invasions. We suggest the application of the dark diversity concept is currently an underappreciated source of information that is valuable for conservation applications ranging from macroscale conservation prioritization to more locally scaled restoration ecology and the management of invasive species. © 2016 Society for Conservation Biology.

The Online Dissemination of Nature–Health Concepts: Lessons from Sentiment Analysis of Social Media Relating to “Nature-Deficit Disorder”

PubMed Central

Palomino, Marco; Taylor, Tim; Göker, Ayse; Isaacs, John; Warber, Sara

2016-01-01

Evidence continues to grow supporting the idea that restorative environments, green exercise, and nature-based activities positively impact human health. Nature-deficit disorder, a journalistic term proposed to describe the ill effects of people’s alienation from nature, is not yet formally recognized as a medical diagnosis. However, over the past decade, the phrase has been enthusiastically taken up by some segments of the lay public. Social media, such as Twitter, with its opportunities to gather “big data” related to public opinions, offers a medium for exploring the discourse and dissemination around nature-deficit disorder and other nature–health concepts. In this paper, we report our experience of collecting more than 175,000 tweets, applying sentiment analysis to measure positive, neutral or negative feelings, and preliminarily mapping the impact on dissemination. Sentiment analysis is currently used to investigate the repercussions of events in social networks, scrutinize opinions about products and services, and understand various aspects of the communication in Web-based communities. Based on a comparison of nature-deficit-disorder “hashtags” and more generic nature hashtags, we make recommendations for the better dissemination of public health messages through changes to the framing of messages. We show the potential of Twitter to aid in better understanding the impact of the natural environment on human health and wellbeing. PMID:26797628

Female and Male Teachers' Pro-Environmental Behaviour, Conceptions and Attitudes Towards Nature and the Environment Do Not Differ: Ecofeminism Put to the Test

ERIC Educational Resources Information Center

Mc Ewen, B.; Clément, P.; Gericke, N. M.; Nyberg, E.; Hagman, M.; Landström, J.

2015-01-01

Teachers' pro-environmental behaviour, conceptions and attitudes towards nature and the environment were investigated using 47 questions from the BIOHEAD-Citizen questionnaire. The sample included 1,109 pre- and in-service teachers from Sweden and France. Analyses showed only few significant differences between female and male teachers. Forty-one…

A study of elementary teachers' conceptions of nature of science and their beliefs about the developmental appropriateness and importance of nature of science throughout a professional development program

NASA Astrophysics Data System (ADS)

Adibelli, Elif

This qualitative study aimed to explore the changes in elementary science teachers' conceptions of nature of science (NOS) and their beliefs about the developmental appropriateness and importance of NOS after participating in an academic, year-long professional development program (PDP) as well as the factors facilitating these changes. The PDP consisted of two phases. In the first phase, the participants received NOS training designed with an explicit-reflective instructional approach. In the second phase, the participants implemented several NOS training activities in their classrooms. Four elementary science teachers who volunteered and completed all components of the PDP (i.e., the NOS training and the NOS teaching) comprised the participants of the present study. A multiple-embedded case study design was employed to explore the changes in the elementary science teachers' conceptions of NOS and their beliefs about the developmental appropriateness and importance of NOS. The study data were collected from multiple sources. The primary data sources included (a) Views of Nature of Science Elementary School Version 2 (VNOS-D2) questionnaire (Lederman & Khishfe, 2002), (b) Ideas about Science for Early Elementary (K-4) Students questionnaire (Sweeney, 2010), and (c) follow-up semi-structured interviews. The secondary data sources included videotaping of meetings with teachers, reflective field notes, and artifacts produced by teachers and their students. Data were analyzed using Yin's (1994, 2003) analytic tactics of pattern matching, explanation building, and cross-case synthesis. The findings of the study revealed that the elementary science teachers showed gradual, but substantial changes in their conceptions, and beliefs about the developmental appropriateness and importance of the NOS aspects over the course of participation in the PDP. Moreover, the participants identified nine components in the PDP that facilitated these changes in their conceptions, and

Adsorptive removal of Cu(II) from aqueous solution and industrial effluent using natural/agricultural wastes.

PubMed

Singha, Biswajit; Das, Sudip Kumar

2013-07-01

The potentiality of low cost natural/agricultural waste biomasses for the removal of Cu(II) ion from aqueous solution has been investigated in batch experiments. The effect of various physico-chemical parameters such as initial pH, initial Cu(II) concentration, adsorbent dosage, contact time and temperature has been studied. The optimum pH for adsorption was found to be 6 for all adsorbents used. Kinetics data were best described by the pseudo-2nd-order model. The experimental data were fitted well with Freundlich and Halsey isotherm models. The diffusion coefficient and sorption energy indicated that the adsorption process was chemical in nature. Thermodynamic parameters such as ΔG°, ΔH° and ΔS° were calculated, and it was observed that the adsorption process was spontaneous and endothermic. The mean sorption energy was calculated using Dubinin-Radushkevich isotherm model and it confirmed that the sorption process was chemical in nature. Different active functional groups were identified by FTIR studies which were responsible for Cu(II) ion adsorption process. Application study using electroplating industrial waste water and regeneration experiment of the adsorbent were also investigated. Design procedure for the batch process was also reported. Copyright © 2013 Elsevier B.V. All rights reserved.

Student Teachers' Conceptions of Teaching Biology

ERIC Educational Resources Information Center

Subramaniam, Karthigeyan

2014-01-01

The purpose of this qualitative study was to investigate prospective biology teachers' conceptions of teaching biology and identify how these conceptions revealed their strategies for helping their future students' learning of biology. The study utilized drawings, narratives and interviews to investigate the nature of the prospective biology…

Euro-NOTES Status Paper: from the concept to clinical practice.

PubMed

Fuchs, K H; Meining, A; von Renteln, D; Fernandez-Esparrach, G; Breithaupt, W; Zornig, C; Lacy, A

2013-05-01

The concept of natural orifice transluminal endoscopic surgery (NOTES) consists of the reduction of access trauma by using a natural orifice access to the intra-abdominal cavity. This could possibly lead to less postoperative pain, quicker recovery from surgery, fewer postoperative complications, fewer wound infections, and fewer long-term problems such as hernias. The Euro-NOTES Foundation has organized yearly meetings to work on this concept to bring it safely into clinical practice. The aim of this Euro-NOTES status update is to assess the yearly scientific working group reports and provide an overview on the current clinical practice of NOTES procedures. After the Euro-NOTES meeting 2011 in Frankfurt, Germany, an analysis was started regarding the most important topics of the European working groups. All prospectively documented information was gathered from Euro-NOTES and D-NOTES working groups from 2007 to 2011. The top five topics were analyzed. The statements of the working group activities demonstrate the growing information and changing insights. The most important selected topics were infection issue, peritoneal access, education and training, platforms and new technology, closure, suture, and anastomosis. The focus on research topics changed over time. The principle of hybrid access has overcome the technical and safety limitations of pure NOTES. Currently the following NOTES access routes are established for several indications: transvaginal access for cholecystectomy, appendectomy and colon resections; transesophageal access for myotomy; transgastric access for full-thickness small-tumor resections; and transanal/transcolonic access for rectal and colon resections. NOTES and hybrid NOTES techniques have emerged for all natural orifices and were introduced into clinical practice with a good safety record. There are different indications for different natural orifices. Each technique has been optimized for the purpose of finding a safe and realistic

Enzymatic production and in situ separation of natural β-ionone from β-carotene.

PubMed

Nacke, Christoph; Hüttmann, Sonja; Etschmann, Maria M W; Schrader, Jens

2012-12-01

A biotechnological process concept for generation and in situ separation of natural β-ionone from β-carotene is presented. The process employs carotenoid cleavage dioxygenases (CCDs), a plant-derived iron-containing nonheme enzyme family requiring only dissolved oxygen as cosubstrate and no additional cofactors. Organophilic pervaporation was found to be very well suited for continuous in situ separation of β-ionone. Its application led to a highly pure product despite the complexity of the reaction solution containing cell homogenates. Among three different pervaporation membrane types tested, a polyoctylmethylsiloxane active layer on a porous polyetherimide support led to the best results. A laboratory-scale demonstration plant was set up, and a highly pure aqueous-ethanolic solution of β-ionone was produced from β-carotene. The described process permits generation of high-value flavor and fragrance compounds bearing the desired label "natural" according to US and European food and safety regulations and demonstrates the potential of CCD enzymes for selective oxidative cleavage of carotenoids.

Prototype Flight Management Capabilities to Explore Temporal RNP Concepts

NASA Technical Reports Server (NTRS)

Ballin, Mark G.; Williams, David H.; Allen, Bonnie Danette; Palmer, Michael T.

2008-01-01

Next Generation Air Transportation System (NextGen) concepts of operation may require aircraft to fly planned trajectories in four dimensions three spatial dimensions and time. A prototype 4D flight management capability is being developed by NASA to facilitate the development of these concepts. New trajectory generation functions extend today's flight management system (FMS) capabilities that meet a single Required Time of Arrival (RTA) to trajectory solutions that comply with multiple RTA constraints. When a solution is not possible, a constraint management capability relaxes constraints to achieve a trajectory solution that meets the most important constraints as specified by candidate NextGen concepts. New flight guidance functions provide continuous guidance to the aircraft s flight control system to enable it to fly specified 4D trajectories. Guidance options developed for research investigations include a moving time window with varying tolerances that are a function of proximity to imposed constraints, and guidance that recalculates the aircraft s planned trajectory as a function of the estimation of current compliance. Compliance tolerances are related to required navigation performance (RNP) through the extension of existing RNP concepts for lateral containment. A conceptual temporal RNP implementation and prototype display symbology are proposed.

An organismal concept for Sengelia radicans gen. et sp. nov. - morphology and natural history of an Early Devonian lycophyte.

PubMed

Matsunaga, Kelly K S; Tomescu, Alexandru M F

2017-05-01

Fossil plants are found as fragmentary remains and understanding them as natural species requires assembly of whole-organism concepts that integrate different plant parts. Such concepts are essential for incorporating fossils in hypotheses of plant evolution and phylogeny. Plants of the Early Devonian are crucial to reconstructing the initial radiation of tracheophytes, yet few are understood as whole organisms. This study assembles a whole-plant concept for the Early Devonian lycophyte Sengelia radicans gen. et sp. nov., based on morphometric data and taphonomic observations from >1000 specimens collected in the Beartooth Butte Formation (Wyoming, USA). Sengelia radicans occupies a key position between stem-group and derived lycophyte lineages. Sengelia had a rooting system of downward-growing root-bearing stems, formed dense monotypic mats of prostrate shoots in areas that experienced periodic flooding, and was characterized by a life-history strategy adapted for survival after floods, dominated by clonality, and featuring infrequent sexual reproduction. Sengelia radicans is the oldest among the very few early tracheophytes for which a detailed, rigorous whole-plant concept integrates morphology, growth habit, life history and growth environment. This plant adds to the diversity of body plans documented among lycophytes and may help elucidate patterns of morphological evolution in the clade. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

NATURAL GRADIENT EXPERIMENT ON SOLUTE TRANSPORT IN A SAND AQUIFER. 2. SPATIAL MOMENTS AND THE ADVECTION AND DISPERSION OF NONREACTIVE TRACERS

EPA Science Inventory

The three-dimensional movement of a tracer plume containing bromide and chloride is investigated using the data base from a large-scale natural gradient field experiment on groundwater solute transport. The analysis focuses on the zeroth-, first-, and second-order spatial moments...

Analysis of sound propagation in ducts using the wave envelope concept

NASA Technical Reports Server (NTRS)

Baumeister, K. J.

1974-01-01

A finite difference formulation is presented for sound propagation in a rectangular two-dimensional duct without steady flow for plane wave input. Before the difference equations are formulated, the governing Helmholtz equation is first transformed to a form whose solution does not oscillate along the length of the duct. This transformation reduces the required number of grid points by an order of magnitude, and the number of grid points becomes independent of the sound frequency. Physically, the transformed pressure represents the amplitude of the conventional sound wave. Example solutions are presented for sound propagation in a one-dimensional straight hard-wall duct and in a two-dimensional straight soft-wall duct without steady flow. The numerical solutions show evidence of the existence along the duct wall of a developing acoustic pressure diffusion boundary layer which is similar in nature to the conventional viscous flow boundary layer. In order to better illustrate this concept, the wave equation and boundary conditions are written such that the frequency no longer appears explicitly in them. The frequency effects in duct propagation can be visualized solely as an expansion and stretching of the suppressor duct.

Deep Borehole Disposal Concept: Development of Universal Canister Concept of Operations

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

Rigali, Mark J.; Price, Laura L.

This report documents key elements of the conceptual design for deep borehole disposal of radioactive waste to support the development of a universal canister concept of operations. A universal canister is a canister that is designed to be able to store, transport, and dispose of radioactive waste without the canister having to be reopened to treat or repackage the waste. This report focuses on the conceptual design for disposal of radioactive waste contained in a universal canister in a deep borehole. The general deep borehole disposal concept consists of drilling a borehole into crystalline basement rock to a depth ofmore » about 5 km, emplacing WPs in the lower 2 km of the borehole, and sealing and plugging the upper 3 km. Research and development programs for deep borehole disposal have been ongoing for several years in the United States and the United Kingdom; these studies have shown that deep borehole disposal of radioactive waste could be safe, cost effective, and technically feasible. The design concepts described in this report are workable solutions based on expert judgment, and are intended to guide follow-on design activities. Both preclosure and postclosure safety were considered in the development of the reference design concept. The requirements and assumptions that form the basis for the deep borehole disposal concept include WP performance requirements, radiological protection requirements, surface handling and transport requirements, and emplacement requirements. The key features of the reference disposal concept include borehole drilling and construction concepts, WP designs, and waste handling and emplacement concepts. These features are supported by engineering analyses.« less

Spatial Modernist Architectural Artistic Concepts

NASA Astrophysics Data System (ADS)

Gudkova, T. V.; Gudkov, A. A.

2017-11-01

The development of a single spatial modernist conception had continued until the middle of the twentieth century. The first authors who proposed the new conceptual solutions of an architectural space that had the greatest impact on the further development of architecture were Le Corbusier, Frank Lloyd Wright, Mies van der Rohein. They embodied different approaches within the common modernist spatial concept using the language of morphological, symbolic and phenomenological descriptions of space. The concept was based on the simplification of functional links, integration of internal architectural space with the environment due to the vanishing of boundaries between them and expansion of their interrelation. Le Corbusier proposed a spatio-temporal concept based on the movement and tempo-rhythmics of the space “from inside to outside.” Frank Lloyd Wright proposed the concept of integral space where inner and outer spaces were the parts of a whole. Mies van der Rohein was the author of the universal space concept in which the idea of the “dissolution” of the inner space in the outer space was embodied.

ASP archiving solution of regional HUSpacs.

PubMed

Pohjonen, Hanna; Kauppinen, Tomi; Ahovuo, Juhani

2004-09-01

The application service provider (ASP) model is not novel, but widely used in several non-health care-related business areas. In this article, ASP is described as a potential solution for long-term and back-up archiving of the picture archiving and communication system (PACS) of the Hospital District of Helsinki and Uusimaa (HUS). HUSpacs is a regional PACS for 21 HUS hospitals serving altogether 1.4 million citizens. The ultimate goal of this study was to define the specifications for the ASP archiving service and to compare different commercial options for archiving solutions (costs derived by unofficial requests for proposal): in-house PACS components, the regional ASP concept and the hospital-based ASP concept. In conclusion, the large scale of the HUS installation enables a cost-effective regional ASP archiving, resulting in a four to five times more economical solution than hospital-based ASP.

Soil engineering in vivo: harnessing natural biogeochemical systems for sustainable, multi-functional engineering solutions

PubMed Central

DeJong, Jason T.; Soga, Kenichi; Banwart, Steven A.; Whalley, W. Richard; Ginn, Timothy R.; Nelson, Douglas C.; Mortensen, Brina M.; Martinez, Brian C.; Barkouki, Tammer

2011-01-01

Carbon sequestration, infrastructure rehabilitation, brownfields clean-up, hazardous waste disposal, water resources protection and global warming—these twenty-first century challenges can neither be solved by the high-energy consumptive practices that hallmark industry today, nor by minor tweaking or optimization of these processes. A more radical, holistic approach is required to develop the sustainable solutions society needs. Most of the above challenges occur within, are supported on, are enabled by or grown from soil. Soil, contrary to conventional civil engineering thought, is a living system host to multiple simultaneous processes. It is proposed herein that ‘soil engineering in vivo’, wherein the natural capacity of soil as a living ecosystem is used to provide multiple solutions simultaneously, may provide new, innovative, sustainable solutions to some of these great challenges of the twenty-first century. This requires a multi-disciplinary perspective that embraces the science of biology, chemistry and physics and applies this knowledge to provide multi-functional civil and environmental engineering designs for the soil environment. For example, can native soil bacterial species moderate the carbonate cycle in soils to simultaneously solidify liquefiable soil, immobilize reactive heavy metals and sequester carbon—effectively providing civil engineering functionality while clarifying the ground water and removing carbon from the atmosphere? Exploration of these ideas has begun in earnest in recent years. This paper explores the potential, challenges and opportunities of this new field, and highlights one biogeochemical function of soil that has shown promise and is developing rapidly as a new technology. The example is used to propose a generalized approach in which the potential of this new field can be fully realized. PMID:20829246

Soil engineering in vivo: harnessing natural biogeochemical systems for sustainable, multi-functional engineering solutions.

PubMed

DeJong, Jason T; Soga, Kenichi; Banwart, Steven A; Whalley, W Richard; Ginn, Timothy R; Nelson, Douglas C; Mortensen, Brina M; Martinez, Brian C; Barkouki, Tammer

2011-01-06

Carbon sequestration, infrastructure rehabilitation, brownfields clean-up, hazardous waste disposal, water resources protection and global warming-these twenty-first century challenges can neither be solved by the high-energy consumptive practices that hallmark industry today, nor by minor tweaking or optimization of these processes. A more radical, holistic approach is required to develop the sustainable solutions society needs. Most of the above challenges occur within, are supported on, are enabled by or grown from soil. Soil, contrary to conventional civil engineering thought, is a living system host to multiple simultaneous processes. It is proposed herein that 'soil engineering in vivo', wherein the natural capacity of soil as a living ecosystem is used to provide multiple solutions simultaneously, may provide new, innovative, sustainable solutions to some of these great challenges of the twenty-first century. This requires a multi-disciplinary perspective that embraces the science of biology, chemistry and physics and applies this knowledge to provide multi-functional civil and environmental engineering designs for the soil environment. For example, can native soil bacterial species moderate the carbonate cycle in soils to simultaneously solidify liquefiable soil, immobilize reactive heavy metals and sequester carbon-effectively providing civil engineering functionality while clarifying the ground water and removing carbon from the atmosphere? Exploration of these ideas has begun in earnest in recent years. This paper explores the potential, challenges and opportunities of this new field, and highlights one biogeochemical function of soil that has shown promise and is developing rapidly as a new technology. The example is used to propose a generalized approach in which the potential of this new field can be fully realized.

Public-private provision of protection measures against natural hazards

NASA Astrophysics Data System (ADS)

Gruber, M.

2009-04-01

Natural hazards threaten human lives as well as economic values of a society. Due to an increasing population density, augmenting property holdings in congested areas as well as higher frequencies of catastrophic events, the damage potential associated with natural hazards is growing. In order to safeguard societal assets against this threat, active and passive protection measures can be established. While passive protection measures provide for this type of risk by means of thorough land use planning, active protection measures aim at improving safety through technical or biological protective systems and structures. However, these provisions are costly and need to be handled prudentially. In most European countries protection measures against natural hazards are provided by the public. Specific governmental funds have been set up for the establishment of preventive systems as well as for damage compensation payments after the occurrence of catastrophic events. Though, additional capital is urgently needed in order to facilitate the realisation of all necessary projects in this field and to provide for maximal safety. One potential solution for such financial deficiencies can be found in Public Private Partnerships (PPP). PPPs have been implemented as attractive concepts for the funding of diverse projects in the fields of e.g. road construction, municipal, health and social services. In principle, they could also provide alternative funding solutions for the establishment of crucial protective infrastructure in respect of natural hazards, adding private financial means to the currently available public funds. Thereby, the entire capacities for catastrophe funding could be enhanced. Beside PPPs, also alternative funding mechanisms such as the emission of catastrophe bonds, contingent credit lines or leasing arrangements may enhance available capacities for the financing of protection measures. This contribution discusses innovative solutions for the funding of

Focusing on the Classical or Contemporary? Chinese Science Teacher Educators' Conceptions of Nature of Science Content to Be Taught to Pre-Service Science Teachers

ERIC Educational Resources Information Center

Wan, Zhi Hong; Wong, Siu Ling; Wei, Bing; Zhan, Ying

2013-01-01

Drawing from the phenomenographic perspective, an exploratory study investigated Chinese teacher educators' conceptions of teaching Nature of Science (NOS) to pre-service science teachers through semi-structured interviews. Five key dimensions emerged from the data. This paper focuses on the dimension, "NOS content to be taught to pre-service…

Integrated Force Method Solution to Indeterminate Structural Mechanics Problems

NASA Technical Reports Server (NTRS)

Patnaik, Surya N.; Hopkins, Dale A.; Halford, Gary R.

2004-01-01

Strength of materials problems have been classified into determinate and indeterminate problems. Determinate analysis primarily based on the equilibrium concept is well understood. Solutions of indeterminate problems required additional compatibility conditions, and its comprehension was not exclusive. A solution to indeterminate problem is generated by manipulating the equilibrium concept, either by rewriting in the displacement variables or through the cutting and closing gap technique of the redundant force method. Compatibility improvisation has made analysis cumbersome. The authors have researched and understood the compatibility theory. Solutions can be generated with equal emphasis on the equilibrium and compatibility concepts. This technique is called the Integrated Force Method (IFM). Forces are the primary unknowns of IFM. Displacements are back-calculated from forces. IFM equations are manipulated to obtain the Dual Integrated Force Method (IFMD). Displacement is the primary variable of IFMD and force is back-calculated. The subject is introduced through response variables: force, deformation, displacement; and underlying concepts: equilibrium equation, force deformation relation, deformation displacement relation, and compatibility condition. Mechanical load, temperature variation, and support settling are equally emphasized. The basic theory is discussed. A set of examples illustrate the new concepts. IFM and IFMD based finite element methods are introduced for simple problems.

FIRST GRADE CHILDREN'S CONCEPT OF ADDITION OF NATURAL NUMBERS.

ERIC Educational Resources Information Center

STEFFE, LESLIE; VAN ENGEN, HENRY

MIDDLE-CLASS, FIRST-GRADE STUDENTS (100) WERE TESTED INDIVIDUALLY ON 4 ITEMS OF CONCEPT OF ADDITION AND CONSERVATION OF NUMBER. THE TEST ITEMS WERE IDENTICAL EXCEPT FOR THE NUMBER OF OBJECTS INVOLVED. FOR EACH ITEM, TWO PILES OF CANDY WERE PLACED BEFORE EACH CHILD AND THEN MOVED TOGETHER. THE STUDY SHOWED NO MAJOR DIFFERENCE IN THE MEAN…

The Unnatural Nature of Nature and Nurture: Questioning the Romantic Heritage

ERIC Educational Resources Information Center

Stables, Andrew

2009-01-01

From a cultural-historical perspective, nature and nurture (and thus education) are contested concepts. The paper focuses on the nature/nurture debate in the work of William Shakespeare (influenced by Montaigne) and in the Romantic tradition (evidenced by Rousseau and Wordsworth), and argues that while our Romantic inheritance (still highly…

Archival storage solutions for PACS

NASA Astrophysics Data System (ADS)

Chunn, Timothy

1997-05-01

While they are many, one of the inhibitors to the wide spread diffusion of PACS systems has been robust, cost effective digital archive storage solutions. Moreover, an automated Nearline solution is key to a central, sharable data repository, enabling many applications such as PACS, telemedicine and teleradiology, and information warehousing and data mining for research such as patient outcome analysis. Selecting the right solution depends on a number of factors: capacity requirements, write and retrieval performance requirements, scaleability in capacity and performance, configuration architecture and flexibility, subsystem availability and reliability, security requirements, system cost, achievable benefits and cost savings, investment protection, strategic fit and more.This paper addresses many of these issues. It compares and positions optical disk and magnetic tape technologies, which are the predominant archive mediums today. Price and performance comparisons will be made at different archive capacities, plus the effect of file size on storage system throughput will be analyzed. The concept of automated migration of images from high performance, high cost storage devices to high capacity, low cost storage devices will be introduced as a viable way to minimize overall storage costs for an archive. The concept of access density will also be introduced and applied to the selection of the most cost effective archive solution.

Data-Intensive Science Meets Inquiry-Driven Pedagogy: Interactive Big Data Exploration, Threshold Concepts, and Liminality

NASA Astrophysics Data System (ADS)

Ramachandran, R.; Nair, U. S.; Word, A.

2014-12-01

Threshold concepts in any discipline are the core concepts an individual must understand in order to master a discipline. By their very nature, these concepts are troublesome, irreversible, integrative, bounded, discursive, and reconstitutive. Although grasping threshold concepts can be extremely challenging for each learner as s/he moves through stages of cognitive development relative to a given discipline, the learner's grasp of these concepts determines the extent to which s/he is prepared to work competently and creatively within the field itself. The movement of individuals from a state of ignorance of these core concepts to one of mastery occurs not along a linear path but in iterative cycles of knowledge creation and adjustment in liminal spaces - conceptual spaces through which learners move from the vaguest awareness of concepts to mastery, accompanied by understanding of their relevance, connectivity, and usefulness relative to questions and constructs in a given discipline. With the explosive growth of data available in atmospheric science, driven largely by satellite Earth observations and high-resolution numerical simulations, paradigms such as that of data-intensive science have emerged. These paradigm shifts are based on the growing realization that current infrastructure, tools and processes will not allow us to analyze and fully utilize the complex and voluminous data that is being gathered. In this emerging paradigm, the scientific discovery process is driven by knowledge extracted from large volumes of data. In this presentation, we contend that this paradigm naturally lends to inquiry-driven pedagogy where knowledge is discovered through inductive engagement with large volumes of data rather than reached through traditional, deductive, hypothesis-driven analyses. In particular, data-intensive techniques married with an inductive methodology allow for exploration on a scale that is not possible in the traditional classroom with its typical

Nature and Nationhood: Danish Perspectives

ERIC Educational Resources Information Center

Schnack, Karsten

2009-01-01

In this paper, I shall discuss Danish perspectives on nature, showing the interdependence of conceptions of "nature" and "nationhood" in the formations of a particular cultural community. Nature, thus construed, is never innocent of culture and cannot therefore simply be "restored" to some pristine, pre-lapsarian…

Bridging the Gap Between Preservice Early Childhood Teachers' Cultural Values, Perceptions of Values Held by Scientists, and the Relationships of These Values to Conceptions of Nature of Science

NASA Astrophysics Data System (ADS)

Akerson, Valarie L.; Buzzelli, Cary A.; Eastwood, Jennifer L.

2012-02-01

This study explored preservice teachers' views of their own cultural values, the cultural values they believed scientists hold, and the relationships of these views to their conceptions of nature of science (NOS). Parallel assignments in a foundations of early childhood education and a science methods course required preservice teachers to explore their own cultural backgrounds and their perceptions of the cultural backgrounds of scientists. The Schwartz Values Inventory was used to measure preservice teachers' personal cultural values and those they perceived of scientists. The Views of Nature of Science version B questionnaire and interviews assessed teachers' conceptions of NOS. Copies of student work were collected and sought for themes indicating how preservice teachers perceived scientists' cultural values and how those perceptions changed over time. We found that from the beginning to the end of the semester, preservice teachers perceived fewer differences between their own cultural values and those they perceived scientists held, though they did not change their own cultural values. We found that preservice teachers' NOS conceptions improved, and that they were related to both their cultural values and those they perceived scientists held. Preservice teachers who indicated the fewest differences between their own cultural values and those they perceived scientists held the most informed conceptions of NOS.

"Disease entity" as the key theoretical concept of medicine.

PubMed

Hucklenbroich, Peter

2014-12-01

Philosophical debates about the concept of disease, particularly of mental disease, might benefit from reconsideration and a closer look at the established terminology and conceptual structure of contemporary medical pathology and clinical nosology. The concepts and principles of medicine differ, to a considerable extent, from the ideas and notions of philosophical theories of disease. In medical theory, the concepts of disease entity and pathologicity are, besides the concept of disease itself, of fundamental importance, and they are essentially connected to the concepts cause of disease or etiological factor, natural course or natural history of disease, and pathological disposition. It is the concept of disease entity that is of key importance for understanding medical pathology and theory of disease. Its central role is shown by a short reconstruction of its main features and its intrinsic connection to the concept of pathologicity. The meaning of pathologicity is elucidated by explicating the underlying criteria. © The Author 2014. Published by Oxford University Press, on behalf of the Journal of Medicine and Philosophy Inc. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Practical solution concepts for planning and designing roadways in Kentucky.

DOT National Transportation Integrated Search

2008-10-01

Kentucky's highway agency has embarked upon an initiative tagged "Practical Solutions" which sets its goal toward reducing costs throughout the project development process extended into operations and maintenance of all highway facilities. This study...

Competition: A Model for Conception.

ERIC Educational Resources Information Center

Kildea, Alice E.

1983-01-01

The Model for the Conception of Competition is offered as a means of discovering problems and solutions surrounding competition. Distinctions are made between existing definitions, and insight into how competition relates to human life and cosmic interaction is given. Survival, mastery, and transcendence, modes of psychological thought, are…

Cloud manufacturing: from concept to practice

NASA Astrophysics Data System (ADS)

Ren, Lei; Zhang, Lin; Tao, Fei; Zhao, Chun; Chai, Xudong; Zhao, Xinpei

2015-02-01

The concept of cloud manufacturing is emerging as a new promising manufacturing paradigm, as well as a business model, which is reshaping the service-oriented, highly collaborative, knowledge-intensive and eco-efficient manufacturing industry. However, the basic concepts about cloud manufacturing are still in discussion. Both academia and industry will need to have a commonly accepted definition of cloud manufacturing, as well as further guidance and recommendations on how to develop and implement cloud manufacturing. In this paper, we review some of the research work and clarify some fundamental terminologies in this field. Further, we developed a cloud manufacturing systems which may serve as an application example. From a systematic and practical perspective, the key requirements of cloud manufacturing platforms are investigated, and then we propose a cloud manufacturing platform prototype, MfgCloud. Finally, a public cloud manufacturing system for small- and medium-sized enterprises (SME) is presented. This paper presents a new perspective for cloud manufacturing, as well as a cloud-to-ground solution. The integrated solution proposed in this paper, including the terminology, MfgCloud, and applications, can push forward this new paradigm from concept to practice.

A system model to integrate the “Green Manufacturing” concept in Romanian manufacturing organisation

NASA Astrophysics Data System (ADS)

Tilină, D. I.; Zapciu, M.; Mohora, C.

2015-11-01

In Romania, the large majorities of the manufacturing companies consume natural resources and energy in an unsustainable manner. Over the years, the emissions of greenhouse gases have led not only to many environmental problems but also to important social and economic problems. A real solution to help the Romanian manufacturing companies to adapt to the new legislative requirements is the green manufacturing implementation. Considering the current situation, the purpose of this paper is to present a model that will integrate the green manufacturing concept at the organizational level based on the practices identified in the Romanian manufacturing companies at the operational level in the context of sustainable development.

The "History" of Victorian Scientific Naturalism: Huxley, Spencer and the "End" of natural history.

PubMed

Lightman, Bernard

2016-08-01

As part of their defence of evolutionary theory, T. H. Huxley and Herbert Spencer argued that natural history was no longer a legitimate scientific discipline. They outlined a secularized concept of life from biology to argue for the validity of naturalism. Despite their support for naturalism, they offered two different responses to the decline of natural history. Whereas Huxley emphasized the creation of a biological discipline, and all that that entailed, Spencer was more concerned with constructing an entire intellectual system based on the idea of evolution. In effect, Spencer wanted to create a new scientific worldview based on evolutionary theory. This had consequences for their understanding of human history, especially of how science had evolved through the ages. It affected their conceptions of human agency, contingency, and directionality in history. Examining Huxley's and Spencer's responses to the "end" of natural history reveals some of the deep divisions within scientific naturalism and the inherent problems of naturalism in general. Whereas Huxley chose to separate the natural and the historical, Spencer opted to fuse them into a single system. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Clastic dikes of the Hatrurim basin (western flank of the Dead Sea) as natural analogues of alkaline concretes: Mineralogy, solution chemistry, and durability

NASA Astrophysics Data System (ADS)

Sokol, E. V.; Gaskova, O. L.; Kozmenko, O. A.; Kokh, S. N.; Vapnik, E. A.; Novikova, S. A.; Nigmatulina, E. N.

2014-11-01

This study shows that the mineral assemblages from clastic dikes in areas adjacent to the Dead Sea graben may be considered as natural analogues of alkaline concretes. The main infilling material of the clastic dikes is composed of well-sorted and well-rounded quartz sand. The cement of these hard rocks contains hydroxylapophyllite, tacharanite, calcium silicate hydrates, opal, calcite, and zeolite-like phases, which is indicative of a similarity of the natural cementation processes and industrial alkaline concrete production from quartz sands and industrial alkaline cements. The quartz grains exhibit a variety of reaction textures reflecting the interaction with alkaline solutions (opal and calcium hydrosilicate overgrowths; full replacement with apophyllite or thomsonite + apophyllite). The physicochemical analysis and reconstruction of the chemical composition of peralkaline Ca, Na, and K solutions that formed these assemblages reveal that the solutions evolved toward a more stable composition of zeolite-like phases, which are more resistant to long-term chemical weathering and atmospheric corrosion. The 40Ar/39Ar age of 6.2 ± 0.7 Ma obtained for apophyllite provides conclusive evidence for the high corrosion resistance of the assemblages consisting of apophyllite and zeolite-like phases.

[Development of the Feelings toward Nature Scale and relationship between feelings toward nature and proximity to nature].

PubMed

Shibata, Seiji

2016-04-01

In the field of environmental psychology, there is rapidly growing interest in the concept of connectivity with nature, describing an individual's sense of being connected with nature. The author developed a new scale for assessing feelings toward nature, including connectedness. Confirmatory factor analysis indicated a five-factor model consisting of restorativeness, oneness, mystery, care, and aversion. Then, the relationships among availability of nature in respondents' neighborhood, age, and each subscale score of the Feelings toward Nature Scale, were analyzed using structural equation modeling. The availability of nature in neighborhoods was assessed using a geographic information system and respondents' subjective evaluations. Results indicate that overall connectedness to nature is weaker as availability of nature decreases, as assessed by subjective evaluation. Results also suggest that aversion toward nature in younger people is relatively stronger than in older generations.

Natural Resource Damages: A Primer

EPA Pesticide Factsheets

define concepts, terms and discuss topics related to NRD activities such as the authority under which NRD are assessed; definition; role of EPA; designation of Natural Resource Trustees; and conduct of natural resource assessments and restorations.

Space Radiation and the Challenges Towards Effective Shielding Solutions

NASA Technical Reports Server (NTRS)

Barghouty, Abdulnasser

2014-01-01

The hazards of space radiation and their effective mitigation strategies continue to pose special science and technology challenges to NASA. It is widely accepted now that shielding space vehicles and structures will have to rely on new and innovative materials since aluminum, like all high Z materials, are poor shields against the particulate and highly ionizing nature of space radiation. Shielding solutions, motivated and constrained by power and mass limitations, couple this realization with "multifunctionality," both in design concept as well as in material function and composition. Materials endowed with effective shielding properties as well as with some degree of multi-functionality may be the kernel of the so-called "radiation-smart" structures and designs. This talk will present some of the challenges and potential mitigation ideas towards the realization of such structures and designs.

Photosensitized degradation of acetaminophen in natural organic matter solutions: The role of triplet states and oxygen.

PubMed

Li, Yanyun; Pan, Yanheng; Lian, Lushi; Yan, Shuwen; Song, Weihua; Yang, Xin

2017-02-01

The photolysis of acetaminophen, a widely used pharmaceutical, in simulated natural organic matter solutions was investigated. The triplet states of natural organic matter ( 3 NOM*) were found to play the dominant role in its photodegradation, while the contributions from hydroxyl radicals and singlet oxygen were negligible. Dissolved oxygen (DO) plays a dual role. From anaerobic to microaerobic (0.5 mg/L DO) conditions, the degradation rate of acetaminophen increased by 4-fold. That suggests the involvement of DO in reactions with the degradation intermediates. With increasing oxygen levels to saturated conditions (26 mg/L DO), the degradation rate became slower, mainly due to DO's quenching effect on 3 NOM*. Superoxide radical (O 2 - ) did not react with acetaminophen directly, but possibly quenched the intermediates to reverse the degradation process. The main photochemical pathways were shown to involve phenoxyl radical and N-radical cations, finally yielding hydroxylated derivatives, dimers and nitrosophenol. A reaction mechanism involving 3 NOM*, oxygen and O 2 - is proposed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Student Conceptions about Energy in Biological Contexts

ERIC Educational Resources Information Center

Opitz, Sebastian T.; Blankenstein, Andreas; Harms, Ute

2017-01-01

The concept of energy serves biologists as a powerful analytical model to describe phenomena that occurs in the natural world. Due to the concept's relevance, educational standards of different countries identify energy as a core idea for the teaching and learning of biology and other science subjects. However, previous research on students'…

Low self-concept in poor readers: prevalence, heterogeneity, and risk.

PubMed

McArthur, Genevieve; Castles, Anne; Kohnen, Saskia; Banales, Erin

2016-01-01

There is evidence that poor readers are at increased risk for various types of low self-concept-particularly academic self-concept. However, this evidence ignores the heterogeneous nature of poor readers, and hence the likelihood that not all poor readers have low self-concept. The aim of this study was to better understand which types of poor readers have low self-concept. We tested 77 children with poor reading for their age for four types of self-concept, four types of reading, three types of spoken language, and two types of attention. We found that poor readers with poor attention had low academic self-concept, while poor readers with poor spoken language had low general self-concept in addition to low academic self-concept. In contrast, poor readers with typical spoken language and attention did not have low self-concept of any type. We also discovered that academic self-concept was reliably associated with reading and receptive spoken vocabulary, and that general self-concept was reliably associated with spoken vocabulary. These outcomes suggest that poor readers with multiple impairments in reading, language, and attention are at higher risk for low academic and general self-concept, and hence need to be assessed for self-concept in clinical practice. Our results also highlight the need for further investigation into the heterogeneous nature of self-concept in poor readers.

Academic Self-Concept: Modeling and Measuring for Science

NASA Astrophysics Data System (ADS)

Hardy, Graham

2014-08-01

In this study, the author developed a model to describe academic self-concept (ASC) in science and validated an instrument for its measurement. Unlike previous models of science ASC, which envisage science as a homogenous single global construct, this model took a multidimensional view by conceiving science self-concept as possessing distinctive facets including conceptual and procedural elements. In the first part of the study, data were collected from 1,483 students attending eight secondary schools in England, through the use of a newly devised Secondary Self-Concept Science Instrument, and structural equation modeling was employed to test and validate a model. In the second part of the study, the data were analysed within the new self-concept framework to examine learners' ASC profiles across the domains of science, with particular attention paid to age- and gender-related differences. The study found that the proposed science self-concept model exhibited robust measures of fit and construct validity, which were shown to be invariant across gender and age subgroups. The self-concept profiles were heterogeneous in nature with the component relating to self-concept in physics, being surprisingly positive in comparison to other aspects of science. This outcome is in stark contrast to data reported elsewhere and raises important issues about the nature of young learners' self-conceptions about science. The paper concludes with an analysis of the potential utility of the self-concept measurement instrument as a pedagogical device for science educators and learners of science.

Application and Validation of Concept Maturity Assessment Framework

DTIC Science & Technology

2011-03-01

process. The following chapter will discuss a proposed methodology for validation of the concept maturity framwork and its Concept Evaluation and...of each contractor‟s conceptual solution and any gaps in information that may have been overlooked. The organization also commented that the... conceptual and does not have a specific system tied to it is often vulnerable to losing interest and potentially funding from decision makers. However

Low self-concept in poor readers: prevalence, heterogeneity, and risk

PubMed Central

Castles, Anne; Kohnen, Saskia; Banales, Erin

2016-01-01

There is evidence that poor readers are at increased risk for various types of low self-concept—particularly academic self-concept. However, this evidence ignores the heterogeneous nature of poor readers, and hence the likelihood that not all poor readers have low self-concept. The aim of this study was to better understand which types of poor readers have low self-concept. We tested 77 children with poor reading for their age for four types of self-concept, four types of reading, three types of spoken language, and two types of attention. We found that poor readers with poor attention had low academic self-concept, while poor readers with poor spoken language had low general self-concept in addition to low academic self-concept. In contrast, poor readers with typical spoken language and attention did not have low self-concept of any type. We also discovered that academic self-concept was reliably associated with reading and receptive spoken vocabulary, and that general self-concept was reliably associated with spoken vocabulary. These outcomes suggest that poor readers with multiple impairments in reading, language, and attention are at higher risk for low academic and general self-concept, and hence need to be assessed for self-concept in clinical practice. Our results also highlight the need for further investigation into the heterogeneous nature of self-concept in poor readers. PMID:27867764

Arguing from Nature: The Role of "Nature" in Students' Argumentations on a Socio-Scientific Issue

ERIC Educational Resources Information Center

Nielsen, Jan Alexis

2012-01-01

This paper explores how students invoked different conceptions of "nature" in eight socio-scientific group discussions about human gene therapy. The paper illustrates and discusses how the students articulated nature and to what extent they elicited science factual content in the process. While the students in this study invoked nature at key…

Concept Formation and Abstraction.

ERIC Educational Resources Information Center

Lunzer, Eric A.

1979-01-01

This paper examines the nature of concepts and conceptual processes and the manner of their formation. It argues that a process of successive abstraction and systematization is central to the evolution of conceptual structures. Classificatory processes are discussed and three levels of abstraction outlined. (Author/SJL)

Transactive System: Part I: Theoretical Underpinnings of Payoff Functions, Control Decisions, Information Privacy, and Solution Concepts

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

Lian, Jianming; Zhang, Wei; Sun, Y.

facilitate new transactive energy system design with demonstrable guarantees on stability and performance. Specifically, the goals are to (1) establish a theoretical basis for evaluating the performance of different transactive systems, (2) devise tools to address canonical problems that exemplify challenges and scenarios of transactive systems, and (3) provide guidelines for design of future transactive systems. This report, Part 1 of a two part series, advances the above-listed research objectives by reviewing existing transactive systems and identifying a theoretical foundation that integrates payoff functions, control decisions, information privacy, and mathematical solution concepts.« less

Lesson "Balance in Nature

NASA Astrophysics Data System (ADS)

Chapanova, V.

2012-04-01

Lesson "Balance in Nature" This simulation game-lesson (Balance in Nature) gives an opportunity for the students to show creativity, work independently, and to create models and ideas. It creates future-oriented thought connected to their experience, allowing them to propose solutions for global problems and personal responsibility for their activities. The class is divided in two teams. Each team chooses questions. 1. Question: Pollution in the environment. 2. Question: Care for nature and climate. The teams work on the chosen tasks. They make drafts, notes and formulate their solutions on small pieces of paper, explaining the impact on nature and society. They express their points of view using many different opinions. This generates alternative thoughts and results in creative solutions. With the new knowledge and positive behaviour defined, everybody realizes that they can do something positive towards nature and climate problems and the importance of individuals for solving global problems is evident. Our main goal is to recover the ecological balance, and everybody explains his or her own well-grounded opinions. In this work process the students obtain knowledge, skills and more responsible behaviour. This process, based on his or her own experience, dialogue and teamwork, helps the participant's self-development. Making the model "human↔ nature" expresses how human activities impact the natural Earth and how these impacts in turn affect society. Taking personal responsibility, we can reduce global warming and help the Earth. By helping nature we help ourselves. Teacher: Veselina Boycheva-Chapanova " Saint Patriarch Evtimii" Scholl Str. "Ivan Vazov"-19 Plovdiv Bulgaria

School Students' Conceptions about Biodiversity Loss: Definitions, Reasons, Results and Solutions

ERIC Educational Resources Information Center

Kilinc, Ahmet; Yesiltas, Namik Kemal; Kartal, Tezcan; Demiral, Ümit; Eroglu, Baris

2013-01-01

Environmental degradation stemming from anthropocentric causes threatens the biodiversity more than ever before, leading scholars to warn governments about the impending consequences of biodiversity loss (BL). At this point, it is of great importance to study the public's conceptions of BL in order to identify significant educational implications.…

New fundamental evidence of non-classical structure in the combination of natural concepts.

PubMed

Aerts, D; Sozzo, S; Veloz, T

2016-01-13

We recently performed cognitive experiments on conjunctions and negations of two concepts with the aim of investigating the combination problem of concepts. Our experiments confirmed the deviations (conceptual vagueness, underextension, overextension etc.) from the rules of classical (fuzzy) logic and probability theory observed by several scholars in concept theory, while our data were successfully modelled in a quantum-theoretic framework developed by ourselves. In this paper, we isolate a new, very stable and systematic pattern of violation of classicality that occurs in concept combinations. In addition, the strength and regularity of this non-classical effect leads us to believe that it occurs at a more fundamental level than the deviations observed up to now. It is our opinion that we have identified a deep non-classical mechanism determining not only how concepts are combined but, rather, how they are formed. We show that this effect can be faithfully modelled in a two-sector Fock space structure, and that it can be exactly explained by assuming that human thought is the superposition of two processes, a 'logical reasoning', guided by 'logic', and a 'conceptual reasoning', guided by 'emergence', and that the latter generally prevails over the former. All these findings provide new fundamental support to our quantum-theoretic approach to human cognition. © 2015 The Author(s).

The use of solution adaptive grids in solving partial differential equations

NASA Technical Reports Server (NTRS)

Anderson, D. A.; Rai, M. M.

1982-01-01

The grid point distribution used in solving a partial differential equation using a numerical method has a substantial influence on the quality of the solution. An adaptive grid which adjusts as the solution changes provides the best results when the number of grid points available for use during the calculation is fixed. Basic concepts used in generating and applying adaptive grids are reviewed in this paper, and examples illustrating applications of these concepts are presented.

Hydrophobic Solvation: Aqueous Methane Solutions

ERIC Educational Resources Information Center

Konrod, Oliver; Lankau, Timm

2007-01-01

A basic introduction to concept of a solvation shell around an apolar solute as well as its detection is presented. The hydrophobic solvation of toluene is found to be a good teaching example which connects macroscopic, phenomenological thermodynamic results with an atomistic point of view.

The concept of human dignity in the ethics of genetic research.

PubMed

Chan, David K

2015-05-01

Despite criticism that dignity is a vague and slippery concept, a number of international guidelines on bioethics have cautioned against research that is contrary to human dignity, with reference specifically to genetic technology. What is the connection between genetic research and human dignity? In this article, I investigate the concept of human dignity in its various historical forms, and examine its status as a moral concept. Unlike Kant's ideal concept of human dignity, the empirical or relational concept takes human dignity as something that is affected by one's circumstances and what others do. I argue that the dignity objection to some forms of genetic research rests on a view of human nature that gives humans a special status in nature - one that is threatened by the potential of genetic research to reduce individuals to their genetic endowment. I distinguish two main philosophical accounts of human nature. One of these, the Aristotelian view, is compatible with the use of genetic technology to help humans realize their inherent potential to a fuller extent. © 2014 John Wiley & Sons Ltd.

Exact Solution to Finite Temperature SFDM: Natural Cores without Feedback

NASA Astrophysics Data System (ADS)

Robles, Victor H.; Matos, T.

2013-01-01

Recent high-quality observations of low surface brightness (LSB) galaxies have shown that their dark matter (DM) halos prefer flat central density profiles. However, the standard cold dark matter model simulations predict a more cuspy behavior. One mechanism used to reconcile the simulations with the observed data is the feedback from star formation. While this mechanism may be successful in isolated dwarf galaxies, its success in LSB galaxies remains unclear. Additionally, the inclusion of too much feedback in the simulations is a double-edged sword—in order to obtain a cored DM distribution from an initially cuspy one, the feedback recipes usually require one to remove a large quantity of baryons from the center of the galaxies; however, some feedback recipes produce twice the number of satellite galaxies of a given luminosity and with much smaller mass-to-light ratios from those that are observed. Therefore, one DM profile that produces cores naturally and that does not require large amounts of feedback would be preferable. We find both requirements to be satisfied in the scalar field dark matter model. Here, we consider that DM is an auto-interacting real scalar field in a thermal bath at temperature T with an initial Z 2 symmetric potential. As the universe expands, the temperature drops so that the Z 2 symmetry is spontaneously broken and the field rolls down to a new minimum. We give an exact analytic solution to the Newtonian limit of this system, showing that it can satisfy the two desired requirements and that the rotation curve profile is no longer universal.

A paleo-aerodynamic exploration of the evolution of nature's flyers, man's aircraft, and the needs and options for future technology innovations

NASA Astrophysics Data System (ADS)

Kulfan, Brenda M.

2009-03-01

Insights and observations of fascinating aspects of birds, bugs and flying seeds, of inspired aerodynamic concepts, and visions of past, present and future aircraft developments are presented. The evolution of nature's flyers, will be compared with the corresponding evolution of commercial aircraft. We will explore similarities between nature's creations and man's inventions. Many critical areas requiring future significant technology based solutions remain. With the advent of UAVs and MAVs, the gap between "possible" and "actual" is again very large. Allometric scaling procedures will be used to explore size implications on limitations and performance capabilities of nature's creations. Biologically related technology development concepts including: bionics, biomimicry, neo-bionic, pseudo-mimicry, cybernetic and non-bionic approaches will be discussed and illustrated with numerous examples. Technology development strategies will be discussed along with the pros and cons for each. Future technology developments should include a synergistic coupling of "discovery driven", "product led" and "technology acceleration" strategies. The objective of this presentation is to inspire the creative nature existing within all of us. This is a summary all text version of the complete report with the same title that report includes approximately 80 figures, photos and charts and much more information.

NXE pellicle: offering a EUV pellicle solution to the industry

NASA Astrophysics Data System (ADS)

Brouns, Derk; Bendiksen, Aage; Broman, Par; Casimiri, Eric; Colsters, Paul; Delmastro, Peter; de Graaf, Dennis; Janssen, Paul; van de Kerkhof, Mark; Kramer, Ronald; Kruizinga, Matthias; Kuntzel, Henk; van der Meulen, Frits; Ockwell, David; Peter, Maria; Smith, Daniel; Verbrugge, Beatrijs; van de Weg, David; Wiley, Jim; Wojewoda, Noelie; Zoldesi, Carmen; van Zwol, Pieter

2016-03-01

Towards the end of 2014, ASML committed to provide a EUV pellicle solution to the industry. Last year, during SPIE Microlithography 2015, we introduced the NXE pellicle concept, a removable pellicle solution that is compatible with current and future patterned mask inspection methods. This paper shows results of how we took this concept to a complete EUV pellicle solution for the industry. We will highlight some technical design challenges we faced developing the NXE pellicle and how we solved them. We will also present imaging results of pellicle exposures on a 0.33 NA NXE scanner system. In conjunction with the NXE pellicle, we will also present the supporting tooling we have developed to enable pellicle use.

A new medium for Caenorhabditis elegans toxicology and nanotoxicology studies designed to better reflect natural soil solution conditions.

PubMed

Tyne, William; Lofts, Stephen; Spurgeon, David J; Jurkschat, Kerstin; Svendsen, Claus

2013-08-01

A new toxicity test medium for Caenorhabditis elegans is presented. The test solution is designed to provide a better representation of natural soil pore water conditions than currently available test media. The medium has a composition that can readily be modified to allow for studies of the influences of a range of environmentally relevant parameters on nematode biology and toxicology. Tests conducted in the new medium confirmed that nematodes' reproduction was possible at a range of solution pH levels, offering the potential to conduct toxicity studies under a variety of conditions. A test to establish silver nanoparticle and dissolved silver nitrate toxicity, a study type not feasible in M9 or agar media due to precipitation and nanoparticle agglomeration, indicated lower silver nanoparticle (median effective concentration [EC50] of 6.5 mg Ag/L) than silver nitrate (EC50 0.28 mg Ag/L) toxicity. Characterization identified stable nanoparticle behavior in the new test medium. Copyright © 2013 SETAC.

On the nature of bladder sensation: the concept of sensory modulation.

PubMed

De Wachter, S G; Heeringa, R; van Koeveringe, G A; Gillespie, J I

2011-09-01

Going to the toilet is an essential everyday event. Normally, we do not give much thought to the sensations and factors that trigger voiding behavior: we just go. For many people, this apparently simple task is complicated and dominates their life. They have strong sensations and sudden desires to void, often resulting in incontinence. It is therefore important that we understand the origins for this functional change and identify means to alleviate it. Literature survey. A considerable body of work has focused on this problem and ideas and concepts on the nature of bladder sensations are embedded in the literature. In this paper we argue the necessity to return to first principles and a re-examination of the problem. We explore the use of focus groups to identify relevant bladder sensation and what triggers 'bladder' behavior. We argue that there are differences in what can be described as 'introspective bladder sensations' and the sensations reported immediately before a void, 'void sensations'. Finally, we propose an alternative model describing how peripheral information generating 'introspective sensations' and 'void sensations' might be different but interrelated sensations. By exploring such ideas and identifying such complexity it is our intention to stimulate debate and generate further research in the field in order to understand better the physiology of bladder sensation and the pathology of increased urge, frequency and incontinence. Review of the literature on bladder sensation and the established ideas suggests that we might be missing something and the problem of normal and increased sensation and of urgency may be much more complex. Copyright © 2011 Wiley-Liss, Inc.

Darwin's "Imaginary Illustrations": Creatively Teaching Evolutionary Concepts & the Nature of Science

ERIC Educational Resources Information Center

Love, Alan C.

2010-01-01

An overlooked feature of Darwin's work is his use of "imaginary illustrations" to show that natural selection is competent to produce adaptive, evolutionary change. When set in the context of Darwin's methodology, these thought experiments provide a novel way to teach natural selection and the nature of science.

Concepts of Life in the Contexts of Mars

NASA Technical Reports Server (NTRS)

Des Marais, D. J.

2014-01-01

The search for habitable environments and life requires a working concept of life's fundamental attributes. This concept helps to identify the "services" that an environment must provide to sustain life. We must consider the possibility that extraterrestrial life might differ fundamentally from our own, but it is still worthwhile to begin by hypothesizing attributes of life that might be universal versus ones that reflect local solutions to survival on Earth.

Upwind schemes and bifurcating solutions in real gas computations

NASA Technical Reports Server (NTRS)

Suresh, Ambady; Liou, Meng-Sing

1992-01-01

The area of high speed flow is seeing a renewed interest due to advanced propulsion concepts such as the National Aerospace Plane (NASP), Space Shuttle, and future civil transport concepts. Upwind schemes to solve such flows have become increasingly popular in the last decade due to their excellent shock capturing properties. In the first part of this paper the authors present the extension of the Osher scheme to equilibrium and non-equilibrium gases. For simplicity, the source terms are treated explicitly. Computations based on the above scheme are presented to demonstrate the feasibility, accuracy and efficiency of the proposed scheme. One of the test problems is a Chapman-Jouguet detonation problem for which numerical solutions have been known to bifurcate into spurious weak detonation solutions on coarse grids. Results indicate that the numerical solution obtained depends both on the upwinding scheme used and the limiter employed to obtain second order accuracy. For example, the Osher scheme gives the correct CJ solution when the super-bee limiter is used, but gives the spurious solution when the Van Leer limiter is used. With the Roe scheme the spurious solution is obtained for all limiters.

Free space-planning solutions in the architecture of multi-storey buildings

NASA Astrophysics Data System (ADS)

Ibragimov, Alexander; Danilov, Alexander

2018-03-01

Here some aspects of the development of steel frame structure design from the standpoint of geometry and morphogenesis of bearing steel structures of civil engineering objects. An alternative approach to forming constructive schemes may be application of curved steel elements in the main load-bearing system. As an example, it may be circular and parabolic arches or segments of varying outline and orientation. The considered approach implies creating large internal volumes without loss in the load-bearing capacity of the frame. The basic concept makes possible a wide variety of layout and design solutions. The presence of free internal spaces of large volume in buildings of a "skyscraper" type contributes to resolving a great number of problems, including those of communicative nature.

Using the history of research on sickle-cell anemia to affect preservice teachers' conceptions of the nature of science

NASA Astrophysics Data System (ADS)

Howe, Eric M.

Preservice elementary teachers enrolled in an elective biology course participated in an eight-class unit of instruction based on the history of research in understanding the disease sickle-cell anemia. Students were introduced to the disease as a "mystery" for them to solve, and subsequently developed an understanding of the disease from several disciplines in biology (e.g., genetics, ecology, evolution, molecular biology). The unit involved open-ended problems in which students examined evidence and developed explanations in a manner analogous to the reasoning used by Anthony C. Allison and his colleagues during the early to middle part of the twentieth century. Throughout the unit, students were challenged to explicitly and reflectively connect their work with the historical material to more general conclusions about aspects of the nature of science. These aspects included (a) the nature of scientific theories, (b) the tentative nature of science, (c) the difference between scientific theories and laws, (d) the validity of observational methods in science, and (e) the subjective (theory-laden) nature of science. The research measured students' pre- and post-instruction views by using both an open-ended survey (VNOS) and follow-up, semi-structured interviews. The results indicated that an appreciable number of students underwent a change or enrichment in their views for some of the nature of science aspects. Moreover, change or enrichment in students' views was directly attributable to their work in the sickle-cell unit as evidenced from the specific examples students articulated in their post-instruction responses in support of their more informed views. In general, the findings of this research lend empirical support to the value of having students actively recapitulate the history of science to improve their nature of science conceptions. This is facilitated when the lessons challenge students to explicitly and reflectively develop views of the nature of

Natural adsorbents of dyes from aqueous solution

NASA Astrophysics Data System (ADS)

Rahmani, Meryem; El Hajjaji, souad; Dahchour, Abdelmalek; El M'Rabet, Mohammadine

2017-04-01

Contamination of natural waters is a current environmental problem and lot of work has been done to find methods for its, prevention and remediation such as ionic exchange, adsorption on active carbon, filtration, electrolysis, biodegradation …etc. Adsorption is one of the most applied methods according to its effectiveness and easy management. Some adsorbents with good properties such as active alumina, zeolites, crop residues … etc, are suitable to substitute usual active carbon. This study aimed at the removal of dyes using oil shale as natural support, and its optimization by factorial experiment. Three factors were considered namly:pollutant concentration, pH and weight of the adsorbent. Tests have been performed with cationic and anionic dyes. Experimental results show that pseudo-first-order kinetic model provided the best fit to the experimental data for the adsorption by the oil shale. Langmuir, Freundlich and Temkin isotherm models were tested to fit experimental data, the adsorption equilibrium was well described by Freundlich isotherm for methylorange and Temkin for methyl blue. Analysis were completed by oil shale characterization educing XRD, IR, XRF techniques, and cationic exchange capacity.

Adhesion of bacterial pathogens to soil colloidal particles: influences of cell type, natural organic matter, and solution chemistry.

PubMed

Zhao, Wenqiang; Walker, Sharon L; Huang, Qiaoyun; Cai, Peng

2014-04-15

Bacterial adhesion to granular soil particles is well studied; however, pathogen interactions with naturally occurring colloidal particles (<2 μm) in soil has not been investigated. This study was developed to identify the interaction mechanisms between model bacterial pathogens and soil colloids as a function of cell type, natural organic matter (NOM), and solution chemistry. Specifically, batch adhesion experiments were conducted using NOM-present, NOM-stripped soil colloids, Streptococcus suis SC05 and Escherichia coli WH09 over a wide range of solution pH (4.0-9.0) and ionic strength (IS, 1-100 mM KCl). Cell characterization techniques, Freundlich isotherm, and Derjaguin-Landau-Verwey-Overbeek (DLVO) theory (sphere-sphere model) were utilized to quantitatively determine the interactions between cells and colloids. The adhesion coefficients (Kf) of S. suis SC05 to NOM-present and NOM-stripped soil colloids were significantly higher than E. coli WH09, respectively. Similarly, Kf values of S. suis SC05 and E. coli WH09 adhesion to NOM-stripped soil colloids were greater than those colloids with NOM-present, respectively, suggesting NOM inhibits bacterial adhesion. Cell adhesion to soil colloids declined with increasing pH and enhanced with rising IS (1-50 mM). Interaction energy calculations indicate these adhesion trends can be explained by DLVO-type forces, with S. suis SC05 and E. coli WH09 being weakly adhered in shallow secondary energy minima via polymer bridging and charge heterogeneity. S. suis SC05 adhesion decreased at higher IS 100 mM, which is attributed to the change of hydrophobic effect and steric repulsion resulted from the greater presence of extracellular polymeric substances (EPS) on S. suis SC05 surface as compared to E. coli WH09. Hence, pathogen adhesion to the colloidal material is determined by a combination of DLVO, charge heterogeneity, hydrophobic and polymer interactions as a function of solution chemistry. Copyright © 2014 Elsevier

Nature-based supportive care opportunities: a conceptual framework.

PubMed

Blaschke, Sarah; O'Callaghan, Clare C; Schofield, Penelope

2018-03-22

Given preliminary evidence for positive health outcomes related to contact with nature for cancer populations, research is warranted to ascertain possible strategies for incorporating nature-based care opportunities into oncology contexts as additional strategies for addressing multidimensional aspects of cancer patients' health and recovery needs. The objective of this study was to consolidate existing research related to nature-based supportive care opportunities and generate a conceptual framework for discerning relevant applications in the supportive care setting. Drawing on research investigating nature-based engagement in oncology contexts, a two-step analytic process was used to construct a conceptual framework for guiding nature-based supportive care design and future research. Concept analysis methodology generated new representations of understanding by extracting and synthesising salient concepts. Newly formulated concepts were transposed to findings from related research about patient-reported and healthcare expert-developed recommendations for nature-based supportive care in oncology. Five theoretical concepts (themes) were formulated describing patients' reasons for engaging with nature and the underlying needs these interactions address. These included: connecting with what is genuinely valued, distancing from the cancer experience, meaning-making and reframing the cancer experience, finding comfort and safety, and vital nurturance. Eight shared patient and expert recommendations were compiled, which address the identified needs through nature-based initiatives. Eleven additional patient-reported recommendations attend to beneficial and adverse experiential qualities of patients' nature-based engagement and complete the framework. The framework outlines salient findings about helpful nature-based supportive care opportunities for ready access by healthcare practitioners, designers, researchers and patients themselves. © Article author(s) (or their

Extraction of UMLS® Concepts Using Apache cTAKES™ for German Language.

PubMed

Becker, Matthias; Böckmann, Britta

2016-01-01

Automatic information extraction of medical concepts and classification with semantic standards from medical reports is useful for standardization and for clinical research. This paper presents an approach for an UMLS concept extraction with a customized natural language processing pipeline for German clinical notes using Apache cTAKES. The objectives are, to test the natural language processing tool for German language if it is suitable to identify UMLS concepts and map these with SNOMED-CT. The German UMLS database and German OpenNLP models extended the natural language processing pipeline, so the pipeline can normalize to domain ontologies such as SNOMED-CT using the German concepts. For testing, the ShARe/CLEF eHealth 2013 training dataset translated into German was used. The implemented algorithms are tested with a set of 199 German reports, obtaining a result of average 0.36 F1 measure without German stemming, pre- and post-processing of the reports.

Can Nature Protection be Unsustainable? Models Behind Nature Protection in New Zealands National Parks

NASA Astrophysics Data System (ADS)

Hauhs, Michael; Bogner, Christina

2013-04-01

Nature protection can be justified by intrinsic values of life. Western culture sees nature as an autonomous system. Thus, nature protection is often synonymous with refraining from human interference as much as possible. This, however, can pose at least technical problems. Indeed, historical human impacts such as introduced species are often irreversible. In such cases refraining from human interference to protect threatened species is not an adequate management response. Nature protection in New Zealand is a prominent example. Many introduced species make a non-interventionist attitude infeasible to protect endemic species such as kiwis. Actually, active human interference is necessary to attain this goal. Therefore, one may consider nature protection as another form of land use. As any other form of land use, it needs standards of proper management (i.e. explicit goals, assessment, intervention etc.). In other words, it has to be shown to be sustainable. However, sustainability may rigorously be defined as an attribute of past land use only. Instantaneous positive indicators of sustainability may be elusive. At best it can be decided by observation whether or not a land use has been (not) sustainable until now. Stakeholders of nature protection have often different (implicit) concepts or models of nature in mind. This can lead to conflicts when it comes to management decisions. For example, the methods by which conservationists in New Zealand seek to re-establish historical species assemblages (e.g. aerial drop of poison into national parks) have come under criticism of animal rights groups as non-humane. We propose to use abstract modelling language to classify these concepts of nature protection and related issues. We show that from modelling perspective these conflicts pose a basic science problem rather than an applied science problem. This makes the delegation into existing disciplines so hard. We discuss possible implications for nature protection

The restoration experience: volunteers' motives, values, and concepts of nature

Treesearch

Herbert W. Schroeder

2000-01-01

The last several years have brought significant changes in the management of public lands and natural resources in the United States. As a result of debates over management practices, shifts in the goods and services demanded by the public, and evelopment in scientific knowledge, there has emerged a general philosophical shift toward managing natural environmnets as...

Structure and nature of manganese(II) imidazole complexes in frozen aqueous solutions.

PubMed

Un, Sun

2013-04-01

A common feature of a large majority of the manganese metalloenzymes, as well as many synthetic biomimetic complexes, is the bonding between the manganese ion and imidazoles. This interaction was studied by examining the nature and structure of manganese(II) imidazole complexes in frozen aqueous solutions using 285 GHz high magnet-field continuous-wave electron paramagnetic resonance (cw-HFEPR) and 95 GHz pulsed electron-nuclear double resonance (ENDOR) and pulsed electron-double resonance detected nuclear magnetic resonance (PELDOR-NMR). The (55)Mn hyperfine coupling and isotropic g values of Mn(II) in frozen imidazole solutions continuously decreased with increasing imidazole concentration. ENDOR and PELDOR-NMR measurements demonstrated that the structural basis for this behavior arose from the imidazole concentration-dependent distribution of three six-coordinate and two four-coordinate species: [Mn(H2O)6](2+), [Mn(imidazole)(H2O)5](2+), [Mn(imidazole)2(H2O)4](2+), [Mn(imidazole)3(H2O)](2+), and [Mn(imidazole)4](2+). The hyperfine and g values of manganese proteins were also fully consistent with this imidazole effect. Density functional theory methods were used to calculate the structures, spin and charge densities, and hyperfine couplings of a number of different manganese imidazole complexes. The use of density functional theory with large exact-exchange admixture calculations gave isotropic (55)Mn hyperfine couplings that were semiquantitative and of predictive value. The results show that the covalency of the Mn-N bonds play an important role in determining not only magnetic spin parameters but also the structure of the metal binding site. The relationship between the isotropic (55)Mn hyperfine value and the number of imidazole ligands provides a quick and easy test for determining whether a protein binds an Mn(II) ion using histidine residues and, if so, how many are involved. Application of this method shows that as much as 40% of the Mn(II) ions in

Evaluating Battery-like Reactions to Harvest Energy from Salinity Differences using Ammonium Bicarbonate Salt Solutions.

PubMed

Kim, Taeyoung; Rahimi, Mohammad; Logan, Bruce E; Gorski, Christopher A

2016-05-10

Mixing entropy batteries (MEBs) are a new approach to generate electricity from salinity differences between two aqueous solutions. To date, MEBs have only been prepared from solutions containing chloride salts, owing to their relevance in natural salinity gradients created from seawater and freshwater. We hypothesized that MEBs could capture energy using ammonium bicarbonate (AmB), a thermolytic salt that can be used to convert waste heat into salinity gradients. We examined six battery electrode materials. Several of the electrodes were unstable in AmB solutions or failed to produce expected voltages. Of the electrode materials tested, a cell containing a manganese oxide electrode and a metallic lead electrode produced the highest power density (6.3 mW m(-2) ). However, this power density is still low relative to previously reported NaCl-based MEBs and heat recovery systems. This proof-of-concept study demonstrated that MEBs could indeed be used to generate electricity from AmB salinity gradients. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Natural convection in binary gases driven by combined horizontal thermal and vertical solutal gradients

NASA Technical Reports Server (NTRS)

Weaver, J. A.; Viskanta, Raymond

1992-01-01

An investigation of natural convection is presented to examine the influence of a horizontal temperature gradient and a concentration gradient occurring from the bottom to the cold wall in a cavity. As the solutal buoyancy force changes from augmenting to opposing the thermal buoyancy force, the fluid motion switches from unicellular to multicellular flow (fluid motion is up the cold wall and down the hot wall for the bottom counterrotating flow cell). Qualitatively, the agreement between predicted streamlines and smoke flow patterns is generally good. In contrast, agreement between measured and predicted temperature and concentration distributions ranges from fair to poor. Part of the discrepancy can be attributed to experimental error. However, there remains considerable discrepancy between data and predictions due to the idealizations of the mathematical model, which examines only first-order physical effects. An unsteady flow, variable thermophysical properties, conjugate effects, species interdiffusion, and radiation were not accounted for in the model.

Ground to Grits. Scientific Concepts in Nutrition/Agriculture.

ERIC Educational Resources Information Center

Cain, Peggy W.; And Others

This curriculum guide presents an activity-oriented program designed to give students experiences that will help them understand concepts concerning the relationship between science, agriculture, and nutritional needs. Covered in the six units of the guide are reasons for eating certain foods (taste and smell); the nature of food (the concept of…

Analytical Solutions to Coupled HM Problems to Highlight the Nonlocal Nature of Aquifer Storage

NASA Astrophysics Data System (ADS)

De Simone, Silvia; Carrera, Jesús

2017-11-01

Specific storage reflects the volumetric deformation capacity of permeable media. Classical groundwater hydrology equates elastic storage to medium compressibility (plus fluid compressibility times porosity). However, it is unclear if storage behavior can be represented by a single parameter. Hydraulic gradients act as body forces that push the medium in the direction of flow causing it to deform instantaneously everywhere, i.e., even in regions where pressure would not have changed according to conventional fluid flow. Therefore, actual deformation depends not only on the mechanical properties of the medium but also on aquifer geometry and on surrounding strata, which act like constraints to displacements. Here we discuss the question and highlight the nonlocal nature of storage (i.e., the volume of water released at a point depends on the poroelastic response over the whole aquifer). Proper evaluation of transient pressure and water release from storage requires acknowledging the hydromechanical coupling, which generally involves the use of numerical methods. We propose analytical solutions to the HM problem of fluid injection (extraction) into finite aquifers with one-dimensional or cylindrical geometries. We find that pressure response is much faster (virtually instantaneous) and larger than expected from traditional purely hydraulic solutions when aquifer deformation is restrained, whereas the pressure response is reversed (i.e., pressure drop in response to injection) when the permeable medium is free to deform. These findings suggest that accounting for hydromechanical coupling may be required when hydraulic testing is performed in low permeability media, which is becoming increasingly demanded for energy-related applications.

The Effect of Activities in Robotic Applications on Students' Perception on the Nature of Science and Students' Metaphors Related to the Concept of Robot

ERIC Educational Resources Information Center

Korkmaz, Özgen; Altun, Halis; Usta, Ertugrul; Özkaya, Armagan

2014-01-01

The purpose of this study is to examine students' perceptions of the nature of science and metaphors related to the concept of robot, to determine the differentiation in these perceptions and metaphors resulting from LEGO NXT robot applications, and to share some good examples of education-oriented activities with robots. In this study, a hybrid…

Alternative Conceptions about Micro-Organisms Are Influenced by Experiences with Disease in Children

ERIC Educational Resources Information Center

Prokop, Pavol; Fancovicová, Jana; Krajcovicová, Adriána

2016-01-01

Children's ideas concerning natural phenomena often differ from those of scientists, and these ideas are termed as alternative conceptions. The prevalence of alternative conceptions is highest among young children who possess less experience with the natural world as compared with adults. Children's ideas about micro-organisms are of special…

Electromagnetism; Problems and solutions

NASA Astrophysics Data System (ADS)

Ilie, Carolina C.; Schrecengost, Zachariah S.

2016-11-01

Electromagnetism: Problems and solutions is an ideal companion book for the undergraduate student-sophomore, junior, or senior-who may want to work on more problems and receive immediate feedback while studying. Each chapter contains brief theoretical notes followed by the problem text with the solution and ends with a brief bibliography. Also presented are problems more general in nature, which may be a bit more challenging.

As an Infused or a Separated Theme? Chinese Science Teacher Educators' Conceptions of Incorporating Nature of Science Instruction in the Courses of Training Pre-Service Science Teachers

ERIC Educational Resources Information Center

Wan, Zhi Hong; Wong, Siu Ling

2013-01-01

Teaching nature of science (NOS) is beginning to find its place in science education in China. This exploratory study interviewed twenty-four Chinese science teacher educators about their conceptions of teaching NOS to pre-service science teachers. Although five dimensions emerged, this paper mainly focuses on reporting the findings relevant to…

A novel physical eco-hydrological model concept for preferential flow based on experimental applications.

NASA Astrophysics Data System (ADS)

Jackisch, Conrad; van Schaik, Loes; Graeff, Thomas; Zehe, Erwin

2014-05-01

Preferential flow through macropores often determines hydrological characteristics - especially regarding runoff generation and fast transport of solutes. Macropore settings may yet be very different in nature and dynamics, depending on their origin. While biogenic structures follow activity cycles (e.g. earth worms) and population conditions (e.g. roots), pedogenic and geogenic structures may depend on water stress (e.g. cracks) or large events (e.g. flushed voids between skeleton and soil pipes) or simply persist (e.g. bedrock interface). On the one hand, such dynamic site characteristics can be observed in seasonal changes in its reaction to precipitation. On the other hand, sprinkling experiments accompanied by tracers or time-lapse 3D Ground-Penetrating-Radar are suitable tools to determine infiltration patterns and macropore configuration. However, model representation of the macropore-matrix system is still problematic, because models either rely on effective parameters (assuming well-mixed state) or on explicit advection strongly simplifying or neglecting interaction with the diffusive flow domain. Motivated by the dynamic nature of macropores, we present a novel model approach for interacting diffusive and advective water, solutes and energy transport in structured soils. It solely relies on scale- and process-aware observables. A representative set of macropores (data from sprinkling experiments) determines the process model scale through 1D advective domains. These are connected to a 2D matrix domain which is defined by pedo-physical retention properties. Water is represented as particles. Diffusive flow is governed by a 2D random walk of these particles while advection may take place in the macropore domain. Macropore-matrix interaction is computed as dissipation of the advective momentum of a particle by its experienced drag from the matrix domain. Through a representation of matrix and macropores as connected diffusive and advective domains for water

Organizational Systems Theory and Command and Control Concepts

DTIC Science & Technology

2013-03-01

Decentralized C2 • Problem is determinable • Many solutions • Predictable results • Low Risk • Slow feedback loop • Plans: Engineered or designed • C2...of these concepts in the Art of Command and the Science of Control, but lacks a proper model to assist commanders in determining how to correctly...commanders in determining how to correctly apply the concepts based on the operational environment. The paper concludes with a recommendation that the

Biodiversity and the Species Concept-Lineages are not Enough.

PubMed

Freudenstein, John V; Broe, Michael B; Folk, Ryan A; Sinn, Brandon T

2017-07-01

The nature and definition of species continue to be matters of debate. Current views of species often focus on their nature as lineages-maximal reproductive communities through time. Whereas many authors point to the Evolutionary Species Concept as optimal, in its original form it stressed the ecological role of species as well as their history as lineages, but most recent authors have ignored the role aspect of the concept, making it difficult to apply unambiguously in a time-extended way. This trend has been exacerbated by the application of methods and concepts emphasizing the notion of monophyly, originally applied only at higher levels, to the level of individuals, as well as by the current emphasis on molecular data. Hence, some current authors recognize units that are no more than probable exclusive lineages as species. We argue that biodiversity is inherently a phenotypic concept and that role, as manifested in the organismal extended phenotype, is a necessary component of the species concept. Viewing species as historically connected populations with unique role brings together the temporal and phenotypic natures of species, providing a clear way to view species both in a time-limited and time-extended way. Doing so alleviates perceived issues with "paraphyletic species" and returns the focus of species to units that are most relevant for biodiversity. © The Author(s) 2016. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Regulating urban surface runoff through nature-based solutions - An assessment at the micro-scale.

PubMed

Zölch, Teresa; Henze, Lisa; Keilholz, Patrick; Pauleit, Stephan

2017-08-01

Urban development leads to changes of surface cover that disrupt the hydrological cycle in cities. In particular, impermeable surfaces and the removal of vegetation reduce the ability to intercept, store and infiltrate rainwater. Consequently, the volume of stormwater runoff and the risk of local flooding rises. This is further amplified by the anticipated effects of climate change leading to an increased frequency and intensity of heavy rain events. Hence, urban adaptation strategies are required to mitigate those impacts. A nature-based solution, more and more promoted in politics and academia, is urban green infrastructure as it contributes to the resilience of urban ecosystems by providing services to maintain or restore hydrological functions. However, this poses a challenge to urban planners in deciding upon effective adaptation measures as they often lack information on the performance of green infrastructure to moderate surface runoff. It remains unclear what type of green infrastructure (e.g. trees, green roofs), offers the highest potential to reduce discharge volumes and to what extent. Against this background, this study provides an approach to gather quantitative evidence on green infrastructure's regulation potential. We use a micro-scale scenario modelling approach of different variations of green cover under current and future climatic conditions. The scenarios are modelled with MIKE SHE, an integrated hydrological simulation tool, and applied to a high density residential area of perimeter blocks in Munich, Germany. The results reveal that both trees and green roofs increase water storage capacities and hence reduce surface runoff, although the main contribution of trees lies in increasing interception and evapotranspiration, whereas green roofs allow for more retention through water storage in their substrate. With increasing precipitation intensities as projected under climate change their regulating potential decreases due to limited water

Early Developmental Trajectories toward Concepts of Rational Numbers

ERIC Educational Resources Information Center

Kainulainen, Mikko; McMullen, Jake; Lehtinen, Erno

2017-01-01

Difficulties with rational numbers have been explained by a natural number bias, where concepts of natural numbers are inappropriately applied to rational numbers. Overcoming this difficulty may require a radical restructuring of previous knowledge. In order to capture this development, we examined third- to fifth-grade students' understanding of…

Concept maps: A tool for knowledge management and synthesis in web-based conversational learning.

PubMed

Joshi, Ankur; Singh, Satendra; Jaswal, Shivani; Badyal, Dinesh Kumar; Singh, Tejinder

2016-01-01

Web-based conversational learning provides an opportunity for shared knowledge base creation through collaboration and collective wisdom extraction. Usually, the amount of generated information in such forums is very huge, multidimensional (in alignment with the desirable preconditions for constructivist knowledge creation), and sometimes, the nature of expected new information may not be anticipated in advance. Thus, concept maps (crafted from constructed data) as "process summary" tools may be a solution to improve critical thinking and learning by making connections between the facts or knowledge shared by the participants during online discussion This exploratory paper begins with the description of this innovation tried on a web-based interacting platform (email list management software), FAIMER-Listserv, and generated qualitative evidence through peer-feedback. This process description is further supported by a theoretical construct which shows how social constructivism (inclusive of autonomy and complexity) affects the conversational learning. The paper rationalizes the use of concept map as mid-summary tool for extracting information and further sense making out of this apparent intricacy.

Natural Resources for Optogenetic Tools.

PubMed

Mathes, Tilo

2016-01-01

Photoreceptors are found in all kingdoms of life and mediate crucial responses to environmental challenges. Nature has evolved various types of photoresponsive protein structures with different chromophores and signaling concepts for their given purpose. The abundance of these signaling proteins as found nowadays by (meta-)genomic screens enriched the palette of optogenetic tools significantly. In addition, molecular insights into signal transduction mechanisms and design principles from biophysical studies and from structural and mechanistic comparison of homologous proteins opened seemingly unlimited possibilities for customizing the naturally occurring proteins for a given optogenetic task. Here, a brief overview on the photoreceptor concepts already established as optogenetic tools in natural or engineered form, their photochemistry and their signaling/design principles is given. Finally, so far not regarded photosensitive modules and protein architectures with potential for optogenetic application are described.

In vivo microrobots for natural orifice transluminal surgery. Current status and future perspectives.

PubMed

Forgione, A

2009-06-01

The possibility to operate inside the peritoneal cavity through small holes performed in hollow organs that is presented by Natural Orifice Transluminal Endoscopic Surgery (NOTES) represents a major paradigm shift in general surgery. While this new approach seems very appealing from patients' perspectives because it eliminates completely abdominal wall aggression and promises to reduce postoperative pain, it is very challenging for surgeons because of the major constraints imposed by both the mode of access and the limited technology currently available. For this reason NOTES applications at the present time are performed by only a few surgeons and mainly to perform non-complex procedures. While new devices are under development, many of them are trying mainly to simply improve current endoscopic platforms and seem not to offer breakthrough solutions. The numerous challenges introduced by natural orifice approaches require a radical shift in the conception of new technologies in order to make this emerging operative access safe and reproducible. The convergence of several enabling technologies in the field of miniaturization, communication and micro-mechatronics brings the possibility to realize on a large scale the revolutionary concept of miniature in vivo co-operative robots. These robots provide vision and task assistance without the constraints of the entry incision and have been shown in experimental settings to possess many qualities that could be ideal to partner with Natural Orifice Surgery. This article explores the current status of microrobotics as well as presents potential future scenarios of their applications in NOTES.

Formalization of an environmental model using formal concept analysis - FCA

NASA Astrophysics Data System (ADS)

Bourdon-García, Rubén D.; Burgos-Salcedo, Javier D.

2016-08-01

Nowadays, there is a huge necessity to generate novel strategies for social-ecological systems analyses for resolving global sustainability problems. This paper has as main purpose the application of the formal concept analysis to formalize the theory of Augusto Ángel Maya, who without a doubt, was one of the most important environmental philosophers in South America; Ángel Maya proposed and established that Ecosystem-Culture relations, instead Human-Nature ones, are determinants in our understanding and management of natural resources. Based on this, a concept lattice, formal concepts, subconcept-superconcept relations, partially ordered sets, supremum and infimum of the lattice and implications between attributes (Duquenne-Guigues base), were determined for the ecosystem-culture relations.

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

NASA Astrophysics Data System (ADS)

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.

Leveraging natural dynamical structures to explore multi-body systems

NASA Astrophysics Data System (ADS)

Bosanac, Natasha

Multi-body systems have become the target of an increasing number of mission concepts and observations, supplying further information about the composition, origin and dynamical environment of bodies within the solar system and beyond. In many of these scenarios, identification and characterization of the particular solutions that exist in a circular restricted three-body model is valuable. This insight into the underlying natural dynamical structures is achieved via the application of dynamical systems techniques. One application of such analysis is trajectory design for CubeSats, which are intended to explore cislunar space and other planetary systems. These increasingly complex mission objectives necessitate innovative trajectory design strategies for spacecraft within our solar system, as well as the capability for rapid and well-informed redesign. Accordingly, a trajectory design framework is constructed using dynamical systems techniques and demonstrated for the Lunar IceCube mission. An additional application explored in this investigation involves the motion of an exoplanet near a binary star system. Due to the strong gravitational field near a binary star, physicists have previously leveraged these systems as testbeds for examining the validity of gravitational and relativistic theories. In this investigation, a preliminary analysis into the effect of an additional three-body interaction on the dynamical environment near a large mass ratio binary system is conducted. As demonstrated through both of these sample applications, identification and characterization of the natural particular solutions that exist within a multi-body system supports a well-informed and guided analysis.

Solution plasma applications for the synthesis/modification of inorganic nanostructured materials and the treatment of natural polymers

NASA Astrophysics Data System (ADS)

Watthanaphanit, Anyarat; Saito, Nagahiro

2018-01-01

Reducing the use of toxic chemicals, production steps, and time consumption are important concerns for researchers and process engineers to contribute in the quest for an efficient process in any production. If an equipment setup is simple, the process additionally becomes more profitable. Combination of the mentioned requirements has opened up various applications of the solution plasma process (SPP) — a physical means of generating plasma through an electrical discharge in a liquid medium at atmospheric pressure and room temperature. This review shows the progress of scientific research on the applications of the SPP for the synthesis/modification of inorganic nanostructured materials and the treatment of natural polymers. Development achieved in each application is demonstrated.

Representing general theoretical concepts in structural equation models: The role of composite variables

USGS Publications Warehouse

Grace, J.B.; Bollen, K.A.

2008-01-01

Structural equation modeling (SEM) holds the promise of providing natural scientists the capacity to evaluate complex multivariate hypotheses about ecological systems. Building on its predecessors, path analysis and factor analysis, SEM allows for the incorporation of both observed and unobserved (latent) variables into theoretically-based probabilistic models. In this paper we discuss the interface between theory and data in SEM and the use of an additional variable type, the composite. In simple terms, composite variables specify the influences of collections of other variables and can be helpful in modeling heterogeneous concepts of the sort commonly of interest to ecologists. While long recognized as a potentially important element of SEM, composite variables have received very limited use, in part because of a lack of theoretical consideration, but also because of difficulties that arise in parameter estimation when using conventional solution procedures. In this paper we present a framework for discussing composites and demonstrate how the use of partially-reduced-form models can help to overcome some of the parameter estimation and evaluation problems associated with models containing composites. Diagnostic procedures for evaluating the most appropriate and effective use of composites are illustrated with an example from the ecological literature. It is argued that an ability to incorporate composite variables into structural equation models may be particularly valuable in the study of natural systems, where concepts are frequently multifaceted and the influence of suites of variables are often of interest. ?? Springer Science+Business Media, LLC 2007.

Towards eco-friendly crop protection: natural deep eutectic solvents and defensive secondary metabolites.

PubMed

Mouden, Sanae; Klinkhamer, Peter G L; Choi, Young Hae; Leiss, Kirsten A

2017-01-01

With mounting concerns over health and environmental effects of pesticides, the search for environmentally acceptable substitutes has amplified. Plant secondary metabolites appear in the horizon as an attractive solution for green crop protection. This paper reviews the need for changes in the techniques and compounds that, until recently, have been the mainstay for dealing with pest insects. Here we describe and discuss main strategies for selecting plant-derived metabolites as candidates for sustainable agriculture. The second part surveys ten important insecticidal compounds, with special emphasis on those involved in human health. Many of these insecticidal metabolites, however, are crystalline solids with limited solubility which might potentially hamper commercial formulation. As such, we introduce the concept of natural deep eutectic solvents for enhancing solubility and stability of such compounds. The concept, principles and examples of green pest control discussed here offer a new suite of environmental-friendly tools designed to promote and adopt sustainable agriculture.

Submersible Aircraft Concept Design Study

DTIC Science & Technology

2010-08-01

capable of submerging at the expense of in-air efficiency; 2. creating a low density submersible requiring dynamic lift to stay submerged at the...density solution would require some additional submergence force. Whilst dynamic lift underwater could be easily achieved by the already present...turbo-prop characteristics for the submersible aircraft concept. Turbo-props are typically specified in terms of shaft horse power ( shp ) rather than

Concept of waste and its impact on human health.

PubMed

Pashkov, Vitalii M; Batyhina, Olena M; Trotska, Maryna V

Impact of the environment on human health is increasingly being paid attention both at the international level and at the level of individual countries. Among the factors that anyhow can affect it negatively, various objects are distinguished and waste is not of the last consequence. It has different nature of origin, ways of further utilization and a degree of impact on human health and the environment. Its generation, utilization and neutralization are determined by the relevant processes; their research allows continuous improvement and reduction of their negative impact on human health and the environment. To analyze provisions of the international legislation concerning the concept of waste and its classification, as well as its potential impacts on human health and the environment. The study analyzes and uses international legal documents, data of international organizations and scientists' deductions. Furthermore, the study integrates information from scientific journals with scientific methods from the medical and legal point of view. Within the framework of the system approach, as well as analysis and synthesis, the concept of waste, its classification and impact on human health and the environment have been researched. In consequence of the conducted study, it has been found that at the European level, considerable attention is paid to waste in the context of its possible negative impact on human health and the environment. Solution of this problem is carried out with the integrated approach, which is expressed both in enacting statutory acts and amending existing ones, as well as elucidating various aspects at the scientific, methodological, statistical and other levels. Waste in itself has different nature of origin, negative impact, ways of its further utilization. Some kinds of it can be used further in order to achieve other goals and needs that are not related to their generation, others can no longer be used for human benefits taking into account

Special solutions to Chazy equation

NASA Astrophysics Data System (ADS)

Varin, V. P.

2017-02-01

We consider the classical Chazy equation, which is known to be integrable in hypergeometric functions. But this solution has remained purely existential and was never used numerically. We give explicit formulas for hypergeometric solutions in terms of initial data. A special solution was found in the upper half plane H with the same tessellation of H as that of the modular group. This allowed us to derive some new identities for the Eisenstein series. We constructed a special solution in the unit disk and gave an explicit description of singularities on its natural boundary. A global solution to Chazy equation in elliptic and theta functions was found that allows parametrization of an arbitrary solution to Chazy equation. The results have applications to analytic number theory.

Joined up Thinking? Evaluating the Use of Concept-Mapping to Develop Complex System Learning

ERIC Educational Resources Information Center

Stewart, Martyn

2012-01-01

In the physical and natural sciences, the complexity of natural systems and their interactions is becoming better understood. With increased emphasis on learning about complex systems, students will be encountering concepts that are dynamic, ill-structured and interconnected. Concept-mapping is a method considered particularly valuable for…

Microflyers: inspiration from nature

NASA Astrophysics Data System (ADS)

Sirohi, Jayant

2013-04-01

Over the past decade, there has been considerable interest in miniaturizing aircraft to create a class of extremely small, robotic vehicles with a gross mass on the order of tens of grams and a dimension on the order of tens of centimeters. These are collectively refered to as micro aerial vehicles (MAVs) or microflyers. Because the size of microflyers is on the same order as that of small birds and large insects, engineers are turning to nature for inspiration. Bioinspired concepts make use of structural or aerodynamic mechanisms that are observed in insects and birds, such as elastic energy storage and unsteady aerodynamics. Biomimetic concepts attempt to replicate the form and function of natural flyers, such as flapping-wing propulsion and external appearance. This paper reviews recent developments in the area of man-made microflyers. The design space for microflyers will be described, along with fundamental physical limits to miniaturization. Key aerodynamic phenomena at the scale of microflyers will be highlighted. Because the focus is on bioinspiration and biomimetics, scaled-down versions of conventional aircraft, such as fixed wing micro air vehicles and microhelicopters will not be addressed. A few representative bioinspired and biomimetic microflyer concepts developed by researchers will be described in detail. Finally, some of the sensing mechanisms used by natural flyers that are being implemented in man-made microflyers will be discussed.

A method for aircraft concept exploration using multicriteria interactive genetic algorithms

NASA Astrophysics Data System (ADS)

Buonanno, Michael Alexander

2005-08-01

The problem of aircraft concept selection has become increasingly difficult in recent years due to changes in the primary evaluation criteria of concepts. In the past, performance was often the primary discriminator, whereas modern programs have placed increased emphasis on factors such as environmental impact, economics, supportability, aesthetics, and other metrics. The revolutionary nature of the vehicles required to simultaneously meet these conflicting requirements has prompted a shift from design using historical data regression techniques for metric prediction to the use of sophisticated physics-based analysis tools that are capable of analyzing designs outside of the historical database. The use of optimization methods with these physics-based tools, however, has proven difficult because of the tendency of optimizers to exploit assumptions present in the models and drive the design towards a solution which, while promising to the computer, may be infeasible due to factors not considered by the computer codes. In addition to this difficulty, the number of discrete options available at this stage may be unmanageable due to the combinatorial nature of the concept selection problem, leading the analyst to select a sub-optimum baseline vehicle. Some extremely important concept decisions, such as the type of control surface arrangement to use, are frequently made without sufficient understanding of their impact on the important system metrics due to a lack of historical guidance, computational resources, or analysis tools. This thesis discusses the difficulties associated with revolutionary system design, and introduces several new techniques designed to remedy them. First, an interactive design method has been developed that allows the designer to provide feedback to a numerical optimization algorithm during runtime, thereby preventing the optimizer from exploiting weaknesses in the analytical model. This method can be used to account for subjective criteria, or

Inferences of body energy reserves on conception rate of suckled Zebu beef cows subjected to timed artificial insemination followed by natural mating.

PubMed

Ayres, H; Ferreira, R M; Torres-Júnior, J R S; Demétrio, C G B; Sá Filho, M F; Gimenes, L U; Penteado, L; D'Occhio, M J; Baruselli, P S

2014-09-01

The influence of body condition score (BCS), rump fat thickness (RFAT), and live weight (LW), and the changes in these parameters during the interval from 165 of prepartum (i.e., 125 days of prior gestation) to 112 postpartum on first service conception and pregnancy rates were investigated in suckled Zebu (Bos indicus) beef cows (n = 266) subjected to timed artificial insemination (TAI) followed by natural mating. The aforementioned parameters were recorded at 165 ± 14 days (mean ± standard error) prepartum (concurrent with the weaning of previous calf), at parturition, and at 42 ± 7 days (at the onset of the synchronization of ovulation protocol), 82 ± 7 days (30 days after TAI), and 112 ± 7 days (60 days after TAI) postpartum. At the start of the breeding season (BS), cows were subjected to a synchronization of ovulation program for TAI. Bulls were placed with cows 10 days after TAI and remained until the end of the study (112 days postpartum). Cows with the highest BCS at parturition had an increased probability of first service conception rate at 60 days after TAI (P = 0.02) and a reduced probability of occurrence of pregnancy loss (P = 0.05). Also, cows had a greater likelihood of conceiving postpartum if they had greater RFAT and BCS at 165 ± 14 days prepartum (P = 0.01 and P = 0.03, respectively) and at parturition (P = 0.0007 and P = 0.003, respectively). Cows that had an increase in RFAT and BCS during the dry period (i.e., interval from weaning of the previous calf to parturition) also had a greater likelihood of conceiving (P = 0.03 and P = 0.06, respectively) during the BS. Among the different time points, RFAT and BCS at parturition had the largest impact on risk of conception during the BS. The LW was a poor predictor of conception during the BS (P = 0.11-0.68) except for LW at 165 ± 14 days prepartum (P = 0.01). Collectively, the findings indicated that the likelihood of conception during the BS

The health benefits of nature-based solutions to urbanization challenges for children and the elderly - A systematic review.

PubMed

Kabisch, Nadja; van den Bosch, Matilda; Lafortezza, Raffaele

2017-11-01

Urban green and blue spaces promote health by offering areas for physical activity, stress relief, and social interaction, which may be considered as cultural ecosystem services. They also provide a number of regulating ecosystem services that can be regarded as nature-based solutions to mitigate impacts from urbanization-induced challenges. Urban trees and other vegetation provide cooling through shade and evapotranspiration, which reduce the impact of the urban heat island on hot summer days. Urban vegetation may improve air quality by removing air pollutants. Open areas in cities, such as parks, gardens, playgrounds and cemeteries, are unsealed spaces that also improve infiltration during extreme precipitation events providing water regulating functions. All these services have the potential to improve the health of urban residents, particularly of specific vulnerable groups such as children and the elderly. The aim of this paper is to provide an overview of the current state of evidence on the relationship between the health of children and the elderly and urban green and blue spaces that can account as nature-based solutions to urbanization-induced challenges. We discuss potential confounding factors and refer to the different green space metrics used to identify associations to health. From the results, we cannot conclude on a universal protective health effect of urban green and blue spaces for children and the elderly. While the association trend is positive, the results remain inconclusive, context dependent and are partly overridden by socioeconomic confounders. However, the research area is consistently increasing, and we advance important prospects for future research on urban green and blue spaces in the face of global challenges such as urbanization. Copyright © 2017 Elsevier Inc. All rights reserved.

Illustrating Chemical Concepts through Food Systems: Introductory Chemistry Experiments.

ERIC Educational Resources Information Center

Chambers, E., IV; Setser, C. S.

1980-01-01

Demonstrations involving foods that illustrate chemical concepts are described, including vaporization of liquids and Graham's law of diffusion, chemical reaction rates, adsorption, properties of solutions, colloidal dispersions, suspensions, and hydrogen ion concentration. (CS)

Investigating the Nature of Third Grade Students' Experiences with Concept Maps to Support Learning of Science Concepts

ERIC Educational Resources Information Center

Merrill, Margaret L.

2012-01-01

To support and improve effective science teaching, educators need methods to reveal student understandings and misconceptions of science concepts and to offer all students an opportunity to reflect on their own knowledge construction and organization. Students can benefit by engaging in scientific activities in which they build personal…

Developing Pre-Service Teachers' Noticing of Students' Understanding of the Derivative Concept

ERIC Educational Resources Information Center

Sánchez-Matamoros, Gloria; Fernández, Ceneida; Llinares, Salvador

2015-01-01

This research study examines the development of the ability of pre-service teachers to notice signs of students' understanding of the derivative concept. It analyses preservice teachers' interpretations of written solutions to problems involving the derivative concept before and after participating in a teacher training module. The results…

Astronomy in Early Childhood Education: A Concept-Based Approach

ERIC Educational Resources Information Center

Ampartzaki, Maria; Kalogiannakis, Michail

2016-01-01

In an attempt to understand the natural world's phenomena, young children form their perceptions of different aspects of the macrocosm, which they contrast with new scientific concepts. This process calls for an early intervention that will provide the stimuli and the tools for the development of new concepts, ideas, and cognitive structures. The…

Weight, Mass, and Gravity: Threshold Concepts in Learning Science

ERIC Educational Resources Information Center

Bar, Varda; Brosh, Yaffa; Sneider, Cary

2016-01-01

Threshold concepts are essential ideas about the natural world that present either a barrier or a gateway to a deep understanding of science. Weight, mass, and gravity are threshold concepts that underpin students' abilities to understand important ideas in all fields of science, embodied in the performance expectations in the Next Generation…

Enhancing Elementary Pre-service Teachers' Plant Processes Conceptions

NASA Astrophysics Data System (ADS)

Thompson, Stephen L.; Lotter, Christine; Fann, Xumei; Taylor, Laurie

2016-06-01

Researchers examined how an inquiry-based instructional treatment emphasizing interrelated plant processes influenced 210 elementary pre-service teachers' (PTs) conceptions of three plant processes, photosynthesis, cellular respiration, and transpiration, and the interrelated nature of these processes. The instructional treatment required PTs to predict the fate of a healthy plant in a sealed terrarium (Plant-in-a-Jar), justify their predictions, observe the plant over a 5-week period, and complete guided inquiry activities centered on one of the targeted plant processes each week. Data sources included PTs' pre- and post-predictions with accompanying justifications, course artifacts such as weekly terrarium observations and science journal entries, and group models of the interrelated plant processes occurring within the sealed terraria. A subset of 33 volunteer PTs also completed interviews the week the Plant-in-a-Jar scenario was introduced and approximately 4 months after the instructional intervention ended. Pre- and post-predictions from all PTs as well as interview responses from the subgroup of PTs, were coded into categories based on key plant processes emphasized in the Next Generation Science Standards. Study findings revealed that PTs developed more accurate conceptions of plant processes and their interrelated nature as a result of the instructional intervention. Primary patterns of change in PTs' plant process conceptions included development of more accurate conceptions of how water is used by plants, more accurate conceptions of photosynthesis features, and more accurate conceptions of photosynthesis and cellular respiration as transformative processes.

Naturalness and wilderness: the dilemma and irony of managing wilderness

Treesearch

Peter B. Landres; Mark W. Brunson; Linda Merigliano; Charisse Sydoriak; Steve Morton

2000-01-01

This paper summarizes a dialogue session that focused on two concepts that strongly influence nearly all wilderness management: wildness and naturalness. The origin and value of these concepts are discussed, as well as the dilemma and irony that arises when wilderness managers contemplate manipulating the environment to restore naturalness at the risk of reducing...

Using David Lack's Observations of Finch Beak Size to Teach Natural Selection & the Nature of Science

ERIC Educational Resources Information Center

Bierema, Andrea M.-K.; Rudge, David W.

2014-01-01

One of the key aspects of natural selection is competition, yet the concept of competition is not necessarily emphasized in explanations of natural selection. Because of this, we developed an activity for our class that focuses on competition and provides an example of the effects of competition on natural selection. This hands-on activity models…

Bridging the Gap between Preservice Early Childhood Teachers' Cultural Values, Perceptions of Values Held by Scientists, and the Relationships of These Values to Conceptions of Nature of Science

ERIC Educational Resources Information Center

Akerson, Valarie L.; Buzzelli, Cary A.; Eastwood, Jennifer L.

2012-01-01

This study explored preservice teachers' views of their own cultural values, the cultural values they believed scientists hold, and the relationships of these views to their conceptions of nature of science (NOS). Parallel assignments in a foundations of early childhood education and a science methods course required preservice teachers to explore…

Fe hydroxyphosphate precipitation and Fe(II) oxidation kinetics upon aeration of Fe(II) and phosphate-containing synthetic and natural solutions

NASA Astrophysics Data System (ADS)

van der Grift, B.; Behrends, T.; Osté, L. A.; Schot, P. P.; Wassen, M. J.; Griffioen, J.

2016-08-01

Exfiltration of anoxic Fe-rich groundwater into surface water and the concomitant oxidative precipitation of Fe are important processes controlling the transport of phosphate (PO4) from agricultural areas to aquatic systems. Here, we explored the relationship between solution composition, reaction kinetics, and the characteristics of the produced Fe hydroxyphosphate precipitates in a series of aeration experiments with anoxic synthetic water and natural groundwater. A pH stat device was used to maintain constant pH and to record the H+ production during Fe(II) oxidation in the aeration experiments in which the initial aqueous P/Fe ratios ((P/Fe)ini), oxygen concentration and pH were varied. In general, Fe(II) oxidation proceeded slower in the presence of PO4 but the decrease of the PO4 concentration during Fe(II) oxidation due to the formation of Fe hydroxyphosphates caused additional deceleration of the reaction rate. The progress of the reaction could be described using a pseudo-second-order rate law with first-order dependencies on PO4 and Fe(II) concentrations. After PO4 depletion, the Fe(II) oxidation rates increased again and the kinetics followed a pseudo-first-order rate law. The first-order rate constants after PO4 depletion, however, were lower compared to the Fe(II) oxidation in a PO4-free solution. Hence, the initially formed Fe hydroxyphosphates also affect the kinetics of continuing Fe(II) oxidation after PO4 depletion. Presence of aqueous PO4 during oxidation of Fe(II) led to the formation of Fe hydroxyphosphates. The P/Fe ratios of the precipitates ((P/Fe)ppt) and the recorded ratio of H+ production over decrease in dissolved Fe(II) did not change detectably throughout the reaction despite a changing P/Fe ratio in the solution. When (P/Fe)ini was 0.9, precipitates with a (P/Fe)ppt ratio of about 0.6 were formed. In experiments with (P/Fe)ini ratios below 0.6, the (P/Fe)ppt decreased with decreasing (P/Fe)ini and pH value. Aeration experiments with

Constructive Development of the Solutions of Linear Equations in Introductory Ordinary Differential Equations

ERIC Educational Resources Information Center

Mallet, D. G.; McCue, S. W.

2009-01-01

The solution of linear ordinary differential equations (ODEs) is commonly taught in first-year undergraduate mathematics classrooms, but the understanding of the concept of a solution is not always grasped by students until much later. Recognizing what it is to be a solution of a linear ODE and how to postulate such solutions, without resorting to…

Natural Products and HIV/AIDS.

PubMed

Cary, Daniele C; Peterlin, B Matija

2018-01-01

The study of natural products in biomedical research is not a modern concept. Many of the most successful medical therapeutics are derived from natural products, including those studied in the field of HIV/AIDS. Biomedical research has a rich history of discovery based on screens of medicinal herbs and traditional medicine practices. Compounds derived from natural products, which repress HIV and those that activate latent HIV, have been reported. It is important to remember the tradition in medical research to derive therapies based on these natural products and to overcome the negative perception of natural products as an "alternative medicine."

MODELLING OF AGRICHEMICALS IN ENVIRONMENTAL COMPARTMENTS - CONCEPTS, PROBLEMS, AND SOLUTIONS

EPA Science Inventory

The potential of plant protection chemicals to migrate away from application sites and expose non-target biota is of continuing interest and concern to regulatory specialists, ecotoxicologists, agriculturalists, and natural resource managers. Regulatory decisions can wait upon ne...

Systems evaluation of thermal bus concepts

NASA Technical Reports Server (NTRS)

Stalmach, D. D.

1982-01-01

Thermal bus concepts, to provide a centralized thermal utility for large, multihundred kilowatt space platforms, were studied and the results are summarized. Concepts were generated, defined, and screened for inclusion in system level thermal bus trades. Parametric trade studies were conducted in order to define the operational envelope, performance, and physical characteristics of each. Two concepts were selected as offering the most promise for thermal bus development. All of four concepts involved two phase flow in order to meet the required isothermal nature of the thermal bus. Two of the concepts employ a mechanical means to circulate the working fluid, a liquid pump in one case and a vapor compressor in another. Another concept utilizes direct osmosis as the driving force of the thermal bus. The fourth concept was a high capacity monogroove heat pipe. After preliminary sizing and screening, three of these concepts were selected to carry into the trade studies. The monogroove heat pipe concept was deemed unsuitable for further consideration because of its heat transport limitations. One additional concept utilizing capillary forces to drive the working fluid was added. Parametric system level trade studies were performed. Sizing and weight calculations were performed for thermal bus sizes ranging from 5 to 350 kW and operating temperatures in the range of 4 to 120 C. System level considerations such as heat rejection and electrical power penalties and interface temperature losses were included in the weight calculations.

Niels Bohr as philosopher of experiment: Does decoherence theory challenge Bohr's doctrine of classical concepts?

NASA Astrophysics Data System (ADS)

Camilleri, Kristian; Schlosshauer, Maximilian

2015-02-01

Niels Bohr's doctrine of the primacy of "classical concepts" is arguably his most criticized and misunderstood view. We present a new, careful historical analysis that makes clear that Bohr's doctrine was primarily an epistemological thesis, derived from his understanding of the functional role of experiment. A hitherto largely overlooked disagreement between Bohr and Heisenberg about the movability of the "cut" between measuring apparatus and observed quantum system supports the view that, for Bohr, such a cut did not originate in dynamical (ontological) considerations, but rather in functional (epistemological) considerations. As such, both the motivation and the target of Bohr's doctrine of classical concepts are of a fundamentally different nature than what is understood as the dynamical problem of the quantum-to-classical transition. Our analysis suggests that, contrary to claims often found in the literature, Bohr's doctrine is not, and cannot be, at odds with proposed solutions to the dynamical problem of the quantum-classical transition that were pursued by several of Bohr's followers and culminated in the development of decoherence theory.

EFFECTIVE POROSITY IMPLIES EFFECTIVE BULK DENSITY IN SORBING SOLUTE TRANSPORT

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

Flach, G.

2012-02-27

The concept of an effective porosity is widely used in solute transport modeling to account for the presence of a fraction of the medium that effectively does not influence solute migration, apart from taking up space. This non-participating volume or ineffective porosity plays the same role as the gas phase in single-phase liquid unsaturated transport: it increases pore velocity, which is useful towards reproducing observed solute travel times. The prevalent use of the effective porosity concept is reflected by its prominent inclusion in popular texts, e.g., de Marsily (1986), Fetter (1988, 1993) and Zheng and Bennett (2002). The purpose ofmore » this commentary is to point out that proper application of the concept for sorbing solutes requires more than simply reducing porosity while leaving other material properties unchanged. More specifically, effective porosity implies the corresponding need for an effective bulk density in a conventional single-porosity model. The reason is that the designated non-participating volume is composed of both solid and fluid phases, both of which must be neglected for consistency. Said another way, if solute does not enter the ineffective porosity then it also cannot contact the adjoining solid. Conceptually neglecting the fluid portion of the non-participating volume leads to a lower (effective) porosity. Likewise, discarding the solid portion of the non-participating volume inherently leads to a lower or effective bulk density. In the author's experience, practitioners virtually never adjust bulk density when adopting the effective porosity approach.« less

Reaction paths and equilibrium end-points in solid-solution aqueous-solution systems

USGS Publications Warehouse

Glynn, P.D.; Reardon, E.J.; Plummer, Niel; Busenberg, E.

1990-01-01

Equations are presented describing equilibrium in binary solid-solution aqueous-solution (SSAS) systems after a dissolution, precipitation, or recrystallization process, as a function of the composition and relative proportion of the initial phases. Equilibrium phase diagrams incorporating the concept of stoichiometric saturation are used to interpret possible reaction paths and to demonstrate relations between stoichiometric saturation, primary saturation, and thermodynamic equilibrium states. The concept of stoichiometric saturation is found useful in interpreting and putting limits on dissolution pathways, but there currently is no basis for possible application of this concept to the prediction and/ or understanding of precipitation processes. Previously published dissolution experiments for (Ba, Sr)SO4 and (Sr, Ca)C??O3orth. solids are interpreted using equilibrium phase diagrams. These studies show that stoichiometric saturation can control, or at least influence, initial congruent dissolution pathways. The results for (Sr, Ca)CO3orth. solids reveal that stoichiometric saturation can also control the initial stages of incongruent dissolution, despite the intrinsic instability of some of the initial solids. In contrast, recrystallisation experiments in the highly soluble KCl-KBr-H2O system demonstrate equilibrium. The excess free energy of mixing calculated for K(Cl, Br) solids is closely modeled by the relation GE = ??KBr??KClRT[a0 + a1(2??KBr-1)], where a0 is 1.40 ?? 0.02, a1, is -0.08 ?? 0.03 at 25??C, and ??KBr and ??KCl are the mole fractions of KBr and KCl in the solids. The phase diagram constructed using this fit reveals an alyotropic maximum located at ??KBr = 0.676 and at a total solubility product, ???? = [K+]([Cl-] + [Br-]) = 15.35. ?? 1990.

Data-Intensive Science meets Inquiry-Driven Pedagogy: Interactive Big Data Exploration, Threshold Concepts, and Liminality

NASA Technical Reports Server (NTRS)

Ramachandran, Rahul; Word, Andrea; Nair, Udasysankar

2014-01-01

Threshold concepts in any discipline are the core concepts an individual must understand in order to master a discipline. By their very nature, these concepts are troublesome, irreversible, integrative, bounded, discursive, and reconstitutive. Although grasping threshold concepts can be extremely challenging for each learner as s/he moves through stages of cognitive development relative to a given discipline, the learner's grasp of these concepts determines the extent to which s/he is prepared to work competently and creatively within the field itself. The movement of individuals from a state of ignorance of these core concepts to one of mastery occurs not along a linear path but in iterative cycles of knowledge creation and adjustment in liminal spaces - conceptual spaces through which learners move from the vaguest awareness of concepts to mastery, accompanied by understanding of their relevance, connectivity, and usefulness relative to questions and constructs in a given discipline. For example, challenges in the teaching and learning of atmospheric science can be traced to threshold concepts in fluid dynamics. In particular, Dynamic Meteorology is one of the most challenging courses for graduate students and undergraduates majoring in Atmospheric Science. Dynamic Meteorology introduces threshold concepts - those that prove troublesome for the majority of students but that are essential, associated with fundamental relationships between forces and motion in the atmosphere and requiring the application of basic classical statics, dynamics, and thermodynamic principles to the three dimensionally varying atmospheric structure. With the explosive growth of data available in atmospheric science, driven largely by satellite Earth observations and high-resolution numerical simulations, paradigms such as that of dataintensive science have emerged. These paradigm shifts are based on the growing realization that current infrastructure, tools and processes will not allow

Concepts of Nature and Power: Environmental Ethics of the Northern Ute.

ERIC Educational Resources Information Center

Romeo, Stephanie

1985-01-01

Describes the approach to resource development of the Northern Ute tribe of Utah. This model preserves the traditional way of life, increases revenues, and minimizes environmental damage. The Ute's historical background and ideology of nature are discussed as well as their fundamental beliefs and moral imperatives associated with natural elements.…

Generic mission planning concepts for space astronomy missions

NASA Technical Reports Server (NTRS)

Guffin, O. T.; Onken, J. F.

1993-01-01

The past two decades have seen the rapid development of space astronomy, both manned and unmanned, and the concurrent proliferation of the operational concepts and software that have been produced to support each individual project. Having been involved in four of these missions since the '70's and three yet to fly in the present decade, the authors believe it is time to step back and evaluate this body of experience from a macro-systems point of view to determine the potential for generic mission planning concepts that could be applied to future missions. This paper presents an organized evaluation of astronomy mission planning functions, functional flows, iteration cycles, replanning activities, and the requirements that drive individual concepts to specific solutions. The conclusions drawn from this exercise are then used to propose a generic concept that could support multiple missions.

Benefits from a geographers' perspective on human-water systems - the waterscape concept

NASA Astrophysics Data System (ADS)

Evers, Mariele; Höllermann, Britta; Almoradie, Adrian; Taft, Linda

2016-04-01

the knowledge of natural and social sciences by acknowledging their different epistemologies, concepts and methods at the same time, hereby, fostering a true integration of the disciplines. Space and time and feedback loops are the three key factors to understand human-water interactions. Especially, by recognizing the degree of feedback sensitive system parameters can be detected and allow for emerging a set of multiple framings and possible development paths. Therefore, the geographical perspective on the waterscape concept proposes a search apart from one solution or best practice as, in our assumption, there are no single best answers because the human dimension and their action and reaction are guided also beyond perceptions, preferences, benefits and costs. Our waterscape concept allows a multi-spatial and multi-disciplinary perspective on water and its projection into space by acknowledging multiple meanings, alternative framings and possible development paths, hence fostering an integrative perspective on human-water systems. It further provides a fruitful framework for transdisciplinary research approaches since it is open and supports societal co-production and reframing of knowledge and policies. Troy, T. J., Pavao-Zuckerman, M., and Evans, T. P.: Debates Perspectives on socio-hydrology: Socio-hydrologic modeling: Tradeoffs, hypothesis testing, and validation, Water Resour Res, 51, 4806-4814, 10.1002/2015WR017046, 2015

A Method for Aircraft Concept Selection Using Multicriteria Interactive Genetic Algorithms

NASA Technical Reports Server (NTRS)

Buonanno, Michael; Mavris, Dimitri

2005-01-01

The problem of aircraft concept selection has become increasingly difficult in recent years as a result of a change from performance as the primary evaluation criteria of aircraft concepts to the current situation in which environmental effects, economics, and aesthetics must also be evaluated and considered in the earliest stages of the decision-making process. This has prompted a shift from design using historical data regression techniques for metric prediction to the use of physics-based analysis tools that are capable of analyzing designs outside of the historical database. The use of optimization methods with these physics-based tools, however, has proven difficult because of the tendency of optimizers to exploit assumptions present in the models and drive the design towards a solution which, while promising to the computer, may be infeasible due to factors not considered by the computer codes. In addition to this difficulty, the number of discrete options available at this stage may be unmanageable due to the combinatorial nature of the concept selection problem, leading the analyst to arbitrarily choose a sub-optimum baseline vehicle. These concept decisions such as the type of control surface scheme to use, though extremely important, are frequently made without sufficient understanding of their impact on the important system metrics because of a lack of computational resources or analysis tools. This paper describes a hybrid subjective/quantitative optimization method and its application to the concept selection of a Small Supersonic Transport. The method uses Genetic Algorithms to operate on a population of designs and promote improvement by varying more than sixty parameters governing the vehicle geometry, mission, and requirements. In addition to using computer codes for evaluation of quantitative criteria such as gross weight, expert input is also considered to account for criteria such as aeroelasticity or manufacturability which may be impossible or

Challenging the concept of electrochemical discharge using salt solutions for lithium-ion batteries recycling.

PubMed

Ojanen, Severi; Lundström, Mari; Santasalo-Aarnio, Annukka; Serna-Guerrero, Rodrigo

2018-06-01

The use of lithium-ion batteries (LIB) has grown significantly in recent years, making them a promising source of secondary raw materials due to their rich composition of valuable materials such as Co, Ni and Al. However, the high voltage and reactive components of LIBs pose safety hazards during crushing stages in recycling processes, and during storage and transportation. Electrochemical discharge by immersion of spent batteries in salt solutions has been generally accepted as a robust and straightforward discharging step to address these potential hazards. Nonetheless, there is no clear evidence in the literature to support the use of electrochemical discharge in real systems, neither are there clear indications of the real-world limitations of this practice. To that aim, this work presents a series of experiments systematically conducted to study the behavior of LIBs during electrochemical discharge in salt solutions. In the first part of this study, a LIB sample was discharged ex-situ using Pt wires connected to the battery poles and submerged into the electrolyte solution on the opposite end. The evolution of voltage in the battery was measured for solutions of NaCl, NaSO 4 , FeSO 4 , and ZnSO 4 . The results indicate that, among the electrolytes used in the present study, NaCl solution is the most effective for LIBs discharge. The discharge of LIB using sulfate salts is however only possible with the aid of stirring, as deposition of solid precipitated on the electrodes hinder the electrochemical discharge. Furthermore, it was found that the addition of particulates of Fe or Zn as sacrificial metal further enhances the discharging rate, likely due to an increased contact area with the electrolyte solution. While these findings support the idea of using electrochemical discharge as a pre-treatment of LIBs, severe corrosion of the battery poles was observed upon direct immersion of batteries into electrolyte solutions. Prevention of such corrosion requires

Kinetic concepts of thermally stimulated reactions in solids

NASA Astrophysics Data System (ADS)

Vyazovkin, Sergey

Historical analysis suggests that the basic kinetic concepts of reactions in solids were inherited from homogeneous kinetics. These concepts rest upon the assumption of a single-step reaction that disagrees with the multiple-step nature of solid-state processes. The inadequate concepts inspire such unjustified anticipations of kinetic analysis as evaluating constant activation energy and/or deriving a single-step reaction mechanism for the overall process. A more adequate concept is that of the effective activation energy, which may vary with temperature and extent of conversion. The adequacy of this concept is illustrated by literature data as well as by experimental data on the thermal dehydration of calcium oxalate monohydrate and thermal decomposition of calcium carbonate, ammonium nitrate and 1,3,5,7- tetranitro-1,3,5,7-tetrazocine.

Directly Observing Micelle Fusion and Growth in Solution by Liquid-Cell Transmission Electron Microscopy

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

Parent, Lucas R.; Bakalis, Evangelos; Ramírez-Hernández, Abelardo

Amphiphilic small molecules and polymers form commonplace nanoscale macromolecular compartments and bilayers, and as such are truly essential components in all cells and in many cellular processes. The nature of these architectures, including their formation, phase changes, and stimuli-response behaviors, is necessary for the most basic functions of life, and over the past half-century, these natural micellar structures have inspired a vast diversity of industrial products, from biomedicines to detergents, lubricants, and coatings. The importance of these materials and their ubiquity have made them the subject of intense investigation regarding their nanoscale dynamics with increasing interest in obtaining sufficient temporalmore » and spatial resolution to directly observe nanoscale processes. However, the vast majority of experimental methods involve either bulk-averaging techniques including light, neutron, and X-ray scattering, or are static in nature including even the most advanced cryogenic transmission electron microscopy techniques. Here, we employ in situ liquid-cell transmission electron microscopy (LCTEM) to directly observe the evolution of individual amphiphilic block copolymer micellar nanoparticles in solution, in real time with nanometer spatial resolution. These observations, made on a proof-of-concept bioconjugate polymer amphiphile, revealed growth and evolution occurring by unimer addition processes and by particle-particle collision-and-fusion events. The experimental approach, combining direct LCTEM observation, quantitative analysis of LCTEM data, and correlated in silico simulations, provides a unique view of solvated soft matter nanoassemblies as they morph and evolve in time and space, enabling us to capture these phenomena in solution.« less

[Nature as magician: on the Paracelsus heritage of modern medicine].

PubMed

Heinz, Schott

2010-01-01

The concept of "natural magic" (magia naturalis) was very important for medicine and natural science of the early modem period. It stressed a new scientific world view (Weltanschauung) moving away from "supernatural" (superstitious) perceptions and trying to explain all spectacular marvels as results of natural processes. So, Nature (natura), often personified as a female figure, was considered as a (female) magician. Physicians and naturalists should learn from her art to become able to imitate and accomplish her work. In particular this concept was relevant for the al-chemical and magical medicine as the writings of PARACELSUS show. He perceived like many of his contemporaries Nature as a servant of God producing all things according to his will supplying them with "signatures" indicating the scholar (philosophus) their hidden ("natural") powers. The iconography and emblematics of the early modem period--partly directly influenced by the paracelsian thinking--illustrate in different ways the concept of natural magic. Especially the hierarchy God--Nature--Human and the phenomena of light representing divine wisdom and power were imagined. It is remarkable, that also during the enlightenment in regard to artificial electricity and animal magnetism analogous ideas appeared in connection with the light imagery (ether, fluidum). Finally, the romantic natural philosophy dealt with them intensively, and they stimulated not only natural scientific respectively (neuro) physiological, but also psychological (experimental) research.

ASSOCIATIVE CONCEPT LEARNING IN ANIMALS

PubMed Central

Zentall, Thomas R.; Wasserman, Edward A.; Urcuioli, Peter J.

2014-01-01

Nonhuman animals show evidence for three types of concept learning: perceptual or similarity-based in which objects/stimuli are categorized based on physical similarity; relational in which one object/stimulus is categorized relative to another (e.g., same/different); and associative in which arbitrary stimuli become interchangeable with one another by virtue of a common association with another stimulus, outcome, or response. In this article, we focus on various methods for establishing associative concepts in nonhuman animals and evaluate data documenting the development of associative classes of stimuli. We also examine the nature of the common within-class representation of samples that have been associated with the same reinforced comparison response (i.e., many-to-one matching) by describing manipulations for distinguishing possible representations. Associative concepts provide one foundation for human language such that spoken and written words and the objects they represent become members of a class of interchangeable stimuli. The mechanisms of associative concept learning and the behavioral flexibility it allows, however, are also evident in the adaptive behaviors of animals lacking language. PMID:24170540

Promoting Conceptual Understanding via Adaptive Concept Maps

ERIC Educational Resources Information Center

Moore, Jacob P.

2013-01-01

The purpose of this study is to explore the feasibility and effectiveness of a scalable concept map based navigation system for a digital textbook. A literature review has been conducted to identify possible methods to promote conceptual understanding in the context of a digital textbook, and these hypothesized solutions will be evaluated through…

Nursing professionalism: An evolutionary concept analysis

PubMed Central

Ghadirian, Fataneh; Salsali, Mahvash; Cheraghi, Mohammad Ali

2014-01-01

Background: Professionalism is an important feature of the professional jobs. Dynamic nature and the various interpretations of this term lead to multiple definitions of this concept. The aim of this paper is to identify the core attributes of the nursing professionalism. Materials and Methods: We followed Rodgers’ evolutionary method of concept analysis. Texts published in scientific databases about nursing professionalism between 1980 and 2011 were assessed. After applying the selection criteria, the final sample consisting of 4 books and 213 articles was selected, examined, and analyzed in depth. Two experts checked the process of analysis and monitored and reviewed them. Results: The analysis showed that nursing professionalism is determined by three attributes of cognitive, attitudinal, and psychomotor. In addition, the most important antecedents concepts were demographic, experiential, educational, environmental, and attitudinal factors. Conclusion: Nursing professionalism is an inevitable, complex, varied, and dynamic process. In this study, the importance, scope, and concept of professionalism in nursing, the concept of a beginning for further research and development, and expanding the nursing knowledge are explained and clarified. PMID:24554953

The effectiveness of conceptual change texts and concept clipboards in learning the nature of science

NASA Astrophysics Data System (ADS)

Çil, Emine; Çepni, Salih

2016-01-01

Background: One of the most important goals of science education is to enable students to understand the nature of science (NOS). However, generally regular science teaching in classrooms does not help students improve informed NOS views. Purpose: This study investigated the influence of an explicit reflective conceptual change approach compared with an explicit reflective inquiry-oriented approach on seventh graders' understanding of NOS. Sample: The research was conducted with seventh grade students. A total of 44 students participated in the study. Design and method: The study was an interpretive study because this study focused on the meanings that students attach to target aspects of NOS. Participants were divided into two groups, each consisting of 22 students. One of the groups learned NOS with an explicit reflective conceptual change approach. The requirements of conceptual change were provided through the use of conceptual change texts and concept cartoons. The other group learned NOS with an explicit reflective inquiry-oriented approach. The data were collected through open-ended questionnaires and semi-structured interviews. These instruments were employed in a pre-test, a post-test and a delayed test. Students' views of the aspects of NOS were categorized as naive, transitional and informed. Results: The result of this study indicated that before receiving instruction, most of the participants had transitional views of the tentative, empirical and imaginative and creative aspects of the NOS, and they had naive understandings of the distinction between observation and inference. The instruction in the experimental group led to a 60% - a 25% increase in the number of students who possessed an informed understanding of the tentative, empirical, creative and observation and inference aspect of the NOS. The instruction in the control group led to a 30% - a 15% increase in the informed NOS views. Conclusion: The explicit reflective conceptual change approach

Does Disease Matter? Incorporating Solution-Focused Brief Therapy in Alcoholism Treatment.

ERIC Educational Resources Information Center

Osborn, Cynthia J.

1997-01-01

Surveyed alcoholism counselors (N=284) to determine whether the disease concept of alcoholism precludes acceptance and use of Solution-Focused Brief Therapy (SFBT) in alcoholism treatment. Results suggest that SFBT may be feasible for alcoholism treatment and that endorsement of the disease concept is compatible with the principles of SFBT. (EMK)

Use of multiple cluster analysis methods to explore the validity of a community outcomes concept map.

PubMed

Orsi, Rebecca

2017-02-01

Concept mapping is now a commonly-used technique for articulating and evaluating programmatic outcomes. However, research regarding validity of knowledge and outcomes produced with concept mapping is sparse. The current study describes quantitative validity analyses using a concept mapping dataset. We sought to increase the validity of concept mapping evaluation results by running multiple cluster analysis methods and then using several metrics to choose from among solutions. We present four different clustering methods based on analyses using the R statistical software package: partitioning around medoids (PAM), fuzzy analysis (FANNY), agglomerative nesting (AGNES) and divisive analysis (DIANA). We then used the Dunn and Davies-Bouldin indices to assist in choosing a valid cluster solution for a concept mapping outcomes evaluation. We conclude that the validity of the outcomes map is high, based on the analyses described. Finally, we discuss areas for further concept mapping methods research. Copyright © 2016 Elsevier Ltd. All rights reserved.

Concepts of formal concept analysis

NASA Astrophysics Data System (ADS)

Žáček, Martin; Homola, Dan; Miarka, Rostislav

2017-07-01

The aim of this article is apply of Formal Concept Analysis on concept of world. Formal concept analysis (FCA) as a methodology of data analysis, information management and knowledge representation has potential to be applied to a verity of linguistic problems. FCA is mathematical theory for concepts and concept hierarchies that reflects an understanding of concept. Formal concept analysis explicitly formalizes extension and intension of a concept, their mutual relationships. A distinguishing feature of FCA is an inherent integration of three components of conceptual processing of data and knowledge, namely, the discovery and reasoning with concepts in data, discovery and reasoning with dependencies in data, and visualization of data, concepts, and dependencies with folding/unfolding capabilities.

Ash'arite's atomistic conception of the physical world: A restatement

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

Pozi, Firdaus; Othman, Mohd Yusof; Mohamed, Faizal

2013-11-27

Atomism plays an important role in the history of human thought. It can be traced back from Democritus atomos in the 500 BC to particle physics and quantum theory in the 21{sup st} century. However, as it being rejected and developed in the course of history of science, it still brings the fundamental question that perplexes physicists. It gives the views that the world is eternal; that the laws of nature is immutable and eternal therefore all phenomena can be determined through the laws and that there is no reality behind the quantum world. In this paper, we shall brieflymore » describe all these three views on the nature of the physical world or universe and this include on the nature of matter. Then, we shall explain our stand on those conceptions based on the Ash'arites atomistic conception of the physical world. We hope this paper can shed a light on several fundamental issues in the conception of the universe and gives the proper response to them.« less

Viewing experience and naturalness of 3D images

NASA Astrophysics Data System (ADS)

Seuntiëns, Pieter J.; Heynderickx, Ingrid E.; IJsselsteijn, Wijnand A.; van den Avoort, Paul M. J.; Berentsen, Jelle; Dalm, Iwan J.; Lambooij, Marc T.; Oosting, Willem

2005-11-01

The term 'image quality' is often used to measure the performance of an imaging system. Recent research showed however that image quality may not be the most appropriate term to capture the evaluative processes associated with experiencing 3D images. The added value of depth in 3D images is clearly recognized when viewers judge image quality of unimpaired 3D images against their 2D counterparts. However, when viewers are asked to rate image quality of impaired 2D and 3D images, the image quality results for both 2D and 3D images are mainly determined by the introduced artefacts, and the addition of depth in the 3D images is hardly accounted for. In this experiment we applied and tested the more general evaluative concepts of 'naturalness' and 'viewing experience'. It was hypothesized that these concepts would better reflect the added value of depth in 3D images. Four scenes were used varying in dimension (2D and 3D) and noise level (6 levels of white gaussian noise). Results showed that both viewing experience and naturalness were rated higher in 3D than in 2D when the same noise level was applied. Thus, the added value of depth is clearly demonstrated when the concepts of viewing experience and naturalness are being evaluated. The added value of 3D over 2D, expressed in noise level, was 2 dB for viewing experience and 4 dB for naturalness, indicating that naturalness appears the more sensitive evaluative concept for demonstrating the psychological impact of 3D displays.

Allium To Zircon: Mathematics and Nature.

ERIC Educational Resources Information Center

Harrell, Marvin E.; Fosnaugh, Linda S.

1997-01-01

Discusses how nature can illustrate mathematical structures and concepts in the classroom. For example, the upper surface of a typical leaf structure illustrates the notion of tessellating with polygons. Also lists classroom applications and hands-on activities such as growing crystals to investigate the natural forms of polyhedra and measuring…

Communities of Practice and Social Learning Systems: the Career of a Concept

NASA Astrophysics Data System (ADS)

Wenger, Etienne

The concept of community of practice was not born in the systems theory tradition. It has its roots in attempts to develop accounts of the social nature of human learning inspired by anthropology and social theory (Lave, 1988; Bourdieu, 1977; Giddens, 1984; Foucault, 1980; Vygotsky, 1978). But the concept of community of practice is well aligned with the perspective of systems traditions. A community of practice itself can be viewed as a simple social system. And a complex social system can be viewed as constituted by interrelated communities of practice. In this essay I first explore the systemic nature of the concept at these two levels. Then I use this foundation to look at the applications of the concept, some of its main critiques, and its potential for developing a social discipline of learning.

The influence of the history of science course on pre-service science teachers' understanding of the nature of science concepts

NASA Astrophysics Data System (ADS)

Akcay, Behiye

The purpose of this study was to investigate the influence of a history of science course on pre-service science teachers' understanding of the nature of science concepts. Subjects in the study were divided in two groups: (1) students who enrolled in only in the history of science course, (2) students who enrolled both the meaning of science and the history of science courses. An interpretative-descriptive approach and constant comparative analysis were used to identify similarities and differences among pre-service teachers' views about nature of scientific knowledge prior to and after the history of science course. The results of this study indicate that explicitly addressing certain aspects of the nature of science is effective in promoting adequate understanding of the nature of science for pre-service science teachers. Moreover, the results indicate that a student's prior experience with the history of science helps to improve their understanding of the history and nature of science. The history of science course helped pre-service teachers to develop the following views which are parallel with these advocated in both the Benchmarks (AAAS, 1993) and the National Science Education Standards (NRC, 1996) concerning the nature of scientific knowledge: (1) Scientific knowledge is empirically based and an ongoing process of experimentation, investigation, and observation. (2) Science is a human endeavor. (3) People from different cultures, races, genders, and nationality contribute to science. (4) Scientific knowledge is not based on myths, personal beliefs, and religious values. (5) Science background and prior knowledge have important roles for scientific investigations. (6) Scientific theories and laws represent different kinds of knowledge. (7) Science is affected by political, social, and cultural values. (8) Creativity and imagination are used during all stages of scientific investigations. (9) Theories change because of new evidence and new views of existing

Spanish semantic feature production norms for 400 concrete concepts.

PubMed

Vivas, Jorge; Vivas, Leticia; Comesaña, Ana; Coni, Ana García; Vorano, Agostina

2017-06-01

Semantic feature production norms provide many quantitative measures of different feature and concept variables that are necessary to solve some debates surrounding the nature of the organization, both normal and pathological, of semantic memory. Despite the current existence of norms for different languages, there are still no published norms in Spanish. This article presents a new set of norms collected from 810 participants for 400 living and nonliving concepts among Spanish speakers. These norms consist of empirical collections of features that participants used to describe the concepts. Four files were elaborated: a concept-feature file, a concept-concept matrix, a feature-feature matrix, and a significantly correlated features file. We expect that these norms will be useful for researchers in the fields of experimental psychology, neuropsychology, and psycholinguistics.

Food applications of natural antimicrobial compounds.

PubMed

Lucera, Annalisa; Costa, Cristina; Conte, Amalia; Del Nobile, Matteo A

2012-01-01

In agreement with the current trend of giving value to natural and renewable resources, the use of natural antimicrobial compounds, particularly in food and biomedical applications, becomes very frequent. The direct addition of natural compounds to food is the most common method of application, even if numerous efforts have been made to find alternative solutions to the aim of avoiding undesirable inactivation. Dipping, spraying, and coating treatment of food with active solutions are currently applied to product prior to packaging as valid options. The aim of the current work is to give an overview on the use of natural compounds in food sector. In particular, the review will gather numerous case-studies of meat, fish, dairy products, minimally processed fruit and vegetables, and cereal-based products where these compounds found application.

Food applications of natural antimicrobial compounds

PubMed Central

Lucera, Annalisa; Costa, Cristina; Conte, Amalia; Del Nobile, Matteo A.

2012-01-01

In agreement with the current trend of giving value to natural and renewable resources, the use of natural antimicrobial compounds, particularly in food and biomedical applications, becomes very frequent. The direct addition of natural compounds to food is the most common method of application, even if numerous efforts have been made to find alternative solutions to the aim of avoiding undesirable inactivation. Dipping, spraying, and coating treatment of food with active solutions are currently applied to product prior to packaging as valid options. The aim of the current work is to give an overview on the use of natural compounds in food sector. In particular, the review will gather numerous case-studies of meat, fish, dairy products, minimally processed fruit and vegetables, and cereal-based products where these compounds found application. PMID:23060862

Liquid absorbent solutions for separating nitrogen from natural gas

DOEpatents

Friesen, Dwayne T.; Babcock, Walter C.; Edlund, David J.; Lyon, David K.; Miller, Warren K.

2000-01-01

Nitrogen-absorbing and -desorbing compositions, novel ligands and transition metal complexes, and methods of using the same, which are useful for the selective separation of nitrogen from other gases, especially natural gas.

Passive damping concepts for tubular beams with partial rotational and translational end restraints

NASA Technical Reports Server (NTRS)

Razzaq, Zia; Muyundo, David K.

1991-01-01

The main objectives of the study are: (1) identification of potential passive damping concepts for slender tubular structural members with rotational and translational end springs under natural and forced-free vibrations; (2) evaluation of damping efficiencies of the various damping concepts; and (3) evaluation of the suitability of a theoretical finite difference analysis by comparison to the experimental results for the case of natural vibrations. Only member flexural an translation motion is considered. The natural vibration study is conducted on the seven damping concepts and for only one specific initial deflection. The most suitable of the seven dampers is further investigated under forced-free vibrations. In addition only one set of end springs is used for all of the experiments. The results show that passive damping provides a possible approach to structural vibration reduction.

Concepts about forests and water

Treesearch

Gordon W. Stuart; Pamela J. Edwards

2006-01-01

Six concepts concerning forests, forestry, and water resources are discussed: (1) the role of the forest canopy in erosion control; (2) the impact of disturbance on soils; (3) the variability of natural water quality; (4) the impact of harvesting on water quality;( 5) the role of extreme experiments; and (6) the effectiveness of forestry best management practices (BMP...

Apparent Ionic Charge in Electrolyte and Polyelectrolyte Solutions

ERIC Educational Resources Information Center

Magdelenat, H.; And Others

1978-01-01

Compares average displacements of charged particles under thermal motion alone with those obtained by the action of an external electric field to develop a concept of "apparent charge" to approximate actual structural charge in an electrolyte solution. (SL)

Energy as a Natural Resource

ERIC Educational Resources Information Center

Seeger, Raymond J.

1971-01-01

Briefly discusses energy consumption per capita as an index of technical progress, a historical review of concepts related to energy conservation, energy conversion, natural sources, man-made sources, and social implications. (PR)

Exploring the Concept of Healing Spaces.

PubMed

DuBose, Jennifer; MacAllister, Lorissa; Hadi, Khatereh; Sakallaris, Bonnie

2018-01-01

Evidence-based design (EBD) research has demonstrated the power of environmental design to support improved patient, family, and staff outcomes and to minimize or avoid harm in healthcare settings. While healthcare has primarily focused on fixing the body, there is a growing recognition that our healthcare system could do more by promoting overall wellness, and this requires expanding the focus to healing. This article explores how we can extend what we know from EBD about health impacts of spatial design to the more elusive goal of healing. By breaking the concept of healing into antecedent components (emotional, psychological, social, behavioral, and functional), this review of the literature presents the existing evidence to identify how healthcare spaces can foster healing. The environmental variables found to directly affect or facilitate one or more dimension of healing were organized into six groups of variables-homelike environment, access to views and nature, light, noise control, barrier-free environment, and room layout. While there is limited scientific research confirming design solutions for creating healing spaces, the literature search revealed relationships that provide a basis for a draft definition. Healing spaces evoke a sense of cohesion of the mind, body, and spirit. They support healing intention and foster healing relationships.

Emerging concepts for management of river ecosystems and challenges to applied integration of physical and biological sciences in the Pacific Northwest, USA

USGS Publications Warehouse

Rieman, Bruce; Dunham, Jason B.; Clayton, James

2006-01-01

Integration of biological and physical concepts is necessary to understand and conserve the ecological integrity of river systems. Past attempts at integration have often focused at relatively small scales and on mechanistic models that may not capture the complexity of natural systems leaving substantial uncertainty about ecological responses to management actions. Two solutions have been proposed to guide management in the face of that uncertainty: the use of “natural variability” in key environmental patterns, processes, or disturbance as a reference; and the retention of some areas as essentially unmanaged reserves to conserve and represent as much biological diversity as possible. Both concepts are scale dependent because dominant processes or patterns that might be referenced will change with scale. Context and linkages across scales may be as important in structuring biological systems as conditions within habitats used by individual organisms. Both ideas view the physical environment as a template for expression, maintenance, and evolution of ecological diversity. To conserve or restore a diverse physical template it will be important to recognize the ecologically important differences in physical characteristics and processes among streams or watersheds that we might attempt to mimic in management or represent in conservation or restoration reserves.

Titan exploration with advanced systems. A study of future mission concepts

NASA Technical Reports Server (NTRS)

1983-01-01

The requirements, capabilities, and programmatic issues associated with science-intensive mission concepts for the advanced exploration of Saturn's largest satellite are assessed. The key questions to be answered by a Titan exploratory mission are: (1) the atmospheric composition; (2) the atmospheric structure; (3) the nature of the surface; and (4) the nature of the interior of Titan. Five selected mission concepts are described in terms of their design requirements. Mission hardware concepts include balloons and/or blimps which will allow both atmospheric and surface observations for a long period of time. Key aspects of performance analysis are presented. Mission profiles and cost summaries are given. Candidate payloads are identified for imaging and nonimaging orbiters, a buoyant station, a haze probe, and a penetrator.

Information Behavior and Information Practice: Reviewing the "Umbrella Concepts" of Information-Seeking Studies

ERIC Educational Resources Information Center

Savolainen, Reijo

2007-01-01

Information behavior and information practice, two major concepts denoting the general ways in which people deal with information, are analyzed. Because of their general nature, they may be conceived of as umbrella concepts drawing on "umbrella discourses" with similar names. Information behavior is currently the dominating umbrella concept, while…

Fluid balance concepts in medicine: Principles and practice

PubMed Central

Roumelioti, Maria-Eleni; Glew, Robert H; Khitan, Zeid J; Rondon-Berrios, Helbert; Argyropoulos, Christos P; Malhotra, Deepak; Raj, Dominic S; Agaba, Emmanuel I; Rohrscheib, Mark; Murata, Glen H; Shapiro, Joseph I; Tzamaloukas, Antonios H

2018-01-01

The regulation of body fluid balance is a key concern in health and disease and comprises three concepts. The first concept pertains to the relationship between total body water (TBW) and total effective solute and is expressed in terms of the tonicity of the body fluids. Disturbances in tonicity are the main factor responsible for changes in cell volume, which can critically affect brain cell function and survival. Solutes distributed almost exclusively in the extracellular compartment (mainly sodium salts) and in the intracellular compartment (mainly potassium salts) contribute to tonicity, while solutes distributed in TBW have no effect on tonicity. The second body fluid balance concept relates to the regulation and measurement of abnormalities of sodium salt balance and extracellular volume. Estimation of extracellular volume is more complex and error prone than measurement of TBW. A key function of extracellular volume, which is defined as the effective arterial blood volume (EABV), is to ensure adequate perfusion of cells and organs. Other factors, including cardiac output, total and regional capacity of both arteries and veins, Starling forces in the capillaries, and gravity also affect the EABV. Collectively, these factors interact closely with extracellular volume and some of them undergo substantial changes in certain acute and chronic severe illnesses. Their changes result not only in extracellular volume expansion, but in the need for a larger extracellular volume compared with that of healthy individuals. Assessing extracellular volume in severe illness is challenging because the estimates of this volume by commonly used methods are prone to large errors in many illnesses. In addition, the optimal extracellular volume may vary from illness to illness, is only partially based on volume measurements by traditional methods, and has not been determined for each illness. Further research is needed to determine optimal extracellular volume levels in several

Ideas for a Teaching Sequence for the Concept of Energy

ERIC Educational Resources Information Center

Duit, Reinders; Neumann, Knut

2014-01-01

The energy concept is one of the most important ideas for students to understand. Looking at phenomena through the lens of energy provides powerful tools to model, analyse and predict phenomena in the scientific disciplines. The cross-disciplinary nature of the energy concept enables students to look at phenomena from different angles, helping…

Students' and Teachers' Understanding of the Nature of Science: A Reassessment.

ERIC Educational Resources Information Center

Lederman, Norman G.

1986-01-01

High school biology teachers (N=18), and one 10th-grade class of each teacher, were given the Nature of Scientific Knowledge Scale at the beginning and end of a school year to determine their conceptions of the nature of science. Results (such as students not possessing "adequate" conceptions of science) are reported and discussed. (JN)

Finite element concepts in computational aerodynamics

NASA Technical Reports Server (NTRS)

Baker, A. J.

1978-01-01

Finite element theory was employed to establish an implicit numerical solution algorithm for the time averaged unsteady Navier-Stokes equations. Both the multidimensional and a time-split form of the algorithm were considered, the latter of particular interest for problem specification on a regular mesh. A Newton matrix iteration procedure is outlined for solving the resultant nonlinear algebraic equation systems. Multidimensional discretization procedures are discussed with emphasis on automated generation of specific nonuniform solution grids and accounting of curved surfaces. The time-split algorithm was evaluated with regards to accuracy and convergence properties for hyperbolic equations on rectangular coordinates. An overall assessment of the viability of the finite element concept for computational aerodynamics is made.

Photocatalytic degradation of humic substances in aqueous solution using Cu-doped ZnO nanoparticles under natural sunlight irradiation.

PubMed

Maleki, Afshin; Safari, Mahdi; Shahmoradi, Behzad; Zandsalimi, Yahya; Daraei, Hiua; Gharibi, Fardin

2015-11-01

In this study, Cu-doped ZnO nanoparticles were investigated as an efficient synthesized catalyst for photodegradation of humic substances in aqueous solution under natural sunlight irradiation. Cu-doped ZnO nanocatalyst was prepared through mild hydrothermal method and was characterized using FT-IR, powder XRD and SEM techniques. The effect of operating parameters such as doping ratio, initial pH, catalyst dosage, initial concentrations of humic substances and sunlight illuminance were studied on humic substances degradation efficiency. The results of characterization analyses of samples confirmed the proper synthesis of Cu-doped ZnO nanocatalyst. The experimental results indicated the highest degradation efficiency of HS (99.2%) observed using 1.5% Cu-doped ZnO nanoparticles at reaction time of 120 min. Photocatalytic degradation efficiency of HS in a neutral and acidic pH was much higher than that at alkaline pH. Photocatalytic degradation of HS was enhanced with increasing the catalyst dosage and sunlight illuminance, while increasing the initial HS concentration led to decrease in the degradation efficiency of HS. Conclusively, Cu-doped ZnO nanoparticles can be used as a promising and efficient catalyst for degradation of HS under natural sunlight irradiation.

DESIGN CONCEPT FOR AN ELEVATED SOUTH POLE STATION.

DTIC Science & Technology

Because of the failing condition of the present South Pole Station and the need for a station with a minimum life of 15 years, in 1960 the Laboratory...was requested to study design concepts for the South Pole Station. All concepts were to be com patible with the logistical and natural problems...composite design was selected as the most promising for the South Pole Station. Following this selection, a conceptual design was developed. The

Pharmaceutical Perspective on Opalescence and Liquid-Liquid Phase Separation in Protein Solutions.

PubMed

Raut, Ashlesha S; Kalonia, Devendra S

2016-05-02

Opalescence in protein solutions reduces aesthetic appeal of a formulation and can be an indicator of the presence of aggregates or precursor to phase separation in solution signifying reduced product stability. Liquid-liquid phase separation of a protein solution into a protein-rich and a protein-poor phase has been well-documented for globular proteins and recently observed for monoclonal antibody solutions, resulting in physical instability of the formulation. The present review discusses opalescence and liquid-liquid phase separation (LLPS) for therapeutic protein formulations. A brief discussion on theoretical concepts based on thermodynamics, kinetics, and light scattering is presented. This review also discusses theoretical concepts behind intense light scattering in the vicinity of the critical point termed as "critical opalescence". Both opalescence and LLPS are affected by the formulation factors including pH, ionic strength, protein concentration, temperature, and excipients. Literature reports for the effect of these formulation factors on attractive protein-protein interactions in solution as assessed by the second virial coefficient (B2) and the cloud-point temperature (Tcloud) measurements are also presented. The review also highlights pharmaceutical implications of LLPS in protein solutions.

Fostering clinical reasoning in physiotherapy: comparing the effects of concept map study and concept map completion after example study in novice and advanced learners.

PubMed

Montpetit-Tourangeau, Katherine; Dyer, Joseph-Omer; Hudon, Anne; Windsor, Monica; Charlin, Bernard; Mamede, Sílvia; van Gog, Tamara

2017-12-01

Health profession learners can foster clinical reasoning by studying worked examples presenting fully worked out solutions to a clinical problem. It is possible to improve the learning effect of these worked examples by combining them with other learning activities based on concept maps. This study investigated which combinaison of activities, worked examples study with concept map completion or worked examples study with concept map study, fosters more meaningful learning of intervention knowledge in physiotherapy students. Moreover, this study compared the learning effects of these learning activity combinations between novice and advanced learners. Sixty-one second-year physiotherapy students participated in the study which included a pre-test phase, a 130-min guided-learning phase and a four-week self-study phase. During the guided and self-study learning sessions, participants had to study three written worked examples presenting the clinical reasoning for selecting electrotherapeutic currents to treat patients with motor deficits. After each example, participants engaged in either concept map completion or concept map study depending on which learning condition they were randomly allocated to. Students participated in an immediate post-test at the end of the guided-learning phase and a delayed post-test at the end of the self-study phase. Post-tests assessed the understanding of principles governing the domain of knowledge to be learned (conceptual knowledge) and the ability to solve new problems that have similar (i.e., near transfer) or different (i.e., far transfer) solution rationales as problems previously studied in the examples. Learners engaged in concept map completion outperformed those engaged in concept map study on near transfer (p = .010) and far transfer (p < .001) performance. There was a significant interaction effect of learners' prior ability and learning condition on conceptual knowledge but not on near and far transfer performance

Populations, Natural Selection, and Applied Organizational Science.

ERIC Educational Resources Information Center

McKelvey, Bill; Aldrich, Howard

1983-01-01

Deficiencies in existing models in organizational science may be remedied by applying the population approach, with its concepts of taxonomy, classification, evolution, and population ecology; and natural selection theory, with its principles of variation, natural selection, heredity, and struggle for existence, to the idea of organizational forms…

Positive deviance: an elegant solution to a complex problem.

PubMed

Lindberg, Curt; Clancy, Thomas R

2010-04-01

As systems evolve over time, their natural tendency is to become increasingly more complex. Studies in the field of complex systems have generated new perspectives on management in social organizations such as hospitals. Much of this research appears as a natural extension of the cross-disciplinary field of systems theory. This is the 13th in a series of articles applying complex systems science to the traditional management concepts of planning, organizing, directing, coordinating, and controlling. This article provides one example of how concepts taken from complex systems theory can be applied to real-world problems facing nurses today.

Turkish Pupils' Conceptions of the Particulate Nature of Matter

ERIC Educational Resources Information Center

Boz, Yezdan

2006-01-01

The purpose of this research study is to explore year 6, 8 & 11 (13, 15 and 17 years old respectively) Turkish pupils' views about the particulate nature of matter within the context of phase changes. About 300 pupils participated in the study. Questionnaires distributed to year 6, 8 and 11 pupils included 6-item open-ended questions about (a)…

Two-color holography concept (T-CHI)

NASA Technical Reports Server (NTRS)

Vikram, C. S.; Caulfield, H. J.; Workman, G. L.; Trolinger, J. D.; Wood, C. P.; Clark, R. L.; Kathman, A. D.; Ruggiero, R. M.

1990-01-01

The Material Processing in the Space Program of NASA-MSFC was active in developing numerous optical techniques for the characterization of fluids in the vicinity of various materials during crystallization and/or solidification. Two-color holographic interferometry demonstrates that temperature and concentration separation in transparent (T-CHI) model systems is possible. The experiments were performed for particular (succinonitrile) systems. Several solutions are possible in Microgravity Sciences and Applications (MSA) experiments on future Shuttle missions. The theory of the T-CHI concept is evaluated. Although particular cases are used for explanations, the concepts developed will be universal. A breadboard system design is also presented for ultimate fabrication and testing of theoretical findings. New developments in holography involving optical fibers and diode lasers are also incorporated.

Algebraic Concepts: What's Really New in New Curricula?

ERIC Educational Resources Information Center

Star, Jon R.; Herbel-Eisenmann, Beth A.; Smith, John P., III

2000-01-01

Examines 8th grade units from the Connected Mathematics Project (CMP). Identifies differences in older and newer conceptions, fundamental objects of study, typical problems, and typical solution methods in algebra. Also discusses where the issue of what is new in algebra is relevant to many other innovative middle school curricula. (KHR)

THE CHILD'S CONCEPTION OF PHYSICAL CAUSALITY.

ERIC Educational Resources Information Center

PIAGET, JEAN

THE CHILD'S CONCEPTION OF PHYSICAL CAUSALITY WAS INVESTIGATED. THREE METHODS OF INVESTIGATION WERE USED. THE FIRST METHOD WAS PURELY VERBAL, AND CONSISTED OF A SERIES OF QUESTIONS DIRECTED TO CHILDREN, REGARDING SOME NATURAL PHENOMENON. THE SECOND METHOD INVOLVED A HALF-VERBAL, HALF-PRACTICAL APPROACH, WHEREIN A SPECIFIC REFERENCE TO NATURAL…

NASA's Bio-Inspired Acoustic Absorber Concept

NASA Technical Reports Server (NTRS)

Koch, L. Danielle

2017-01-01

Transportation noise pollutes our worlds cities, suburbs, parks, and wilderness areas. NASAs fundamental research in aviation acoustics is helping to find innovative solutions to this multifaceted problem. NASA is learning from nature to develop the next generation of quiet aircraft.The number of road vehicles and airplanes has roughly tripled since the 1960s. Transportation noise is audible in nearly all the counties across the US. Noise can damage your hearing, raise your heart rate and blood pressure, disrupt your sleep, and make communication difficult. Noise pollution threatens wildlife when it prevents animals from hearing prey, predators, and mates. Noise regulations help drive industry to develop quieter aircraft. Noise standards for aircraft have been developed by the International Civil Aviation Organization and adopted by the US Federal Aviation Administration. The US National Park Service is working with the Federal Aviation Administration to try to balance the demand for access to the parks and wilderness areas with preservation of the natural soundscape. NASA is helping by conceptualizing quieter, more efficient aircraft of the future and performing the fundamental research to make these concepts a reality someday. Recently, NASA has developed synthetic structures that can absorb sound well over a wide frequency range, and particularly below 1000 Hz, and which mimic the acoustic performance of bundles of natural reeds. We are adapting these structures to control noise on aircraft, and spacecraft. This technology might be used in many other industrial or architectural applications where acoustic absorbers have tight constraints on weight and thickness, and may be exposed to high temperatures or liquids. Information about this technology is being made available through reports and presentations available through the NASA Technical Report Server, http:ntrs.nasa.gov. Organizations who would like to collaborate with NASA or commercialize NASAs technology

Polarization dependent two-photon absorption spectroscopy on a naturally occurring biomarker (curcumin) in solution: A theoretical-experimental study

NASA Astrophysics Data System (ADS)

Tiburcio-Moreno, Jose A.; Alvarado-Gil, J. J.; Diaz, Carlos; Echevarria, Lorenzo; Hernández, Florencio E.

2013-09-01

We report on the theoretical-experimental analysis of the two-photon absorption (TPA) and two-photon circular-linear dichroism (TPCLD) spectra of (1E,6E)-1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione (curcumin) in Tetrahydrofuran (THF) solution. The measurement of the full TPA spectrum of this molecule reveals a maximum TPA cross-section at 740 nm, i.e. more than 10 times larger than the maximum reported in the literature at 800 nm for the application of curcumin in bioimaging. The TPCLD spectrum exposes the symmetry of the main excited-states involved in the two-photon excitation process. TD-DFT calculations support the experimental results. These outcomes are expected to expand the application of natural-occurring dyes in bioimaging.

An interpretative study of elementary school teachers' conceptions of the nature of inquiry and of their roles while participating in an inquiry based science curriculum

NASA Astrophysics Data System (ADS)

Stucke, Ann Hancock

The problem. Recent reform efforts in science education have culminated in National Science Education Standards (NSES), which include the theme of inquiry across all grade levels. Consideration must be given to teachers' conceptions of inquiry, and their perceived roles, as they implement the processes of inquiry in the science classroom. Because of the change in pedagogy required by the standards, research efforts must address these areas. Research questions. The following research questions guided this study. (1) What are teachers' conceptions of inquiry? (2) What do the teachers consider important aspects of their roles when providing inquiry experiences for their students? (3) What do the teachers consider important aspects of the students' roles as inquirers? Research paradigm and methodology. The research paradigm that grounded this investigation is the constructivist paradigm proposed by Guba and Lincoln (1989). Participants were three elementary school teachers participating in the Elementary School Education Partners project. Qualitative methodology techniques used in the study included focus group discussion, semi-structured interviews, classroom observation with videotaping, teacher reflections, and fieldnotes. Data were analyzed using the constant comparative method as provided by Glaser and Strauss (1967). A case study format was used to discuss the results of themes that emerged. Results. Themes that emerged from the data were (a) inquiry is viewed as a teaching strategy; (b) the teachers' perceptions of the nature of inquiry are different from one another's; (c) there are differences in the degree of fit with the NSES description of inquiry; (d) the manner in which they see themselves as facilitators originates in their own educational experiences and varies from that of a guide, to a monitor, to one who models; and (e) teachers see the role of students as active participants in their learning but the teachers' perceptions of students' roles, as

[Out of natural order: nature in discourses about cloning and stem cell research in Brazilian newspapers].

PubMed

Medeiros, Flavia Natércia da Silva

2013-11-30

Different conceptions of nature influence media coverage and public opinion about biotechnology. This study reports on a discourse analysis of the ideas about nature and what is natural expressed in Brazilian media coverage of cloning and stem cell research. In the discourse against this research, the biotechnologies in question are placed outside the natural order of things and deemed immoral. In the discourse of those who defend it, nature is portrayed as indifferent to the fate of humans or even cruel, or else a barrier to be overcome, while cloning and embryonic stem cells are naturalized and Dolly the sheep is anthropomorphized. The mythifying or transcendental representations of nature do not just influence public opinion, but also have ethical and political implications.

Elucidating Concepts in Drug Design through Taste with Natural and Artificial Sweeteners

ERIC Educational Resources Information Center

Lipchock, James M.; Lipchock, Sarah V.

2016-01-01

Fundamental concepts in biochemistry important for drug design often lack connection to the macroscopic world and can be difficult for students to grasp, particularly those in introductory science courses at the high school and college level. Educational research has shown that multisensory teaching facilitates learning, but teaching at the high…

Web life: Ask Nature

NASA Astrophysics Data System (ADS)

2012-11-01

Ask Nature is a site devoted to biomimicry, an interdisciplinary field in which practitioners study how animals and plants solve problems, and then use those solutions to develop better human technologies.

Synthesis of Diopside by Solution Combustion Process Using Glycine Fuel

NASA Astrophysics Data System (ADS)

Sherikar, Baburao N.; Umarji, A. M.

Nano ceramic Diopside (CaMgSi2O6) powders are synthesized by Solution Combustion Process(SCS) using Calcium nitrate, Magnesium nitrate as oxidizer and glycine as fuel, fumed silica as silica source. Ammonium nitrate (AN) is used as extra oxidizer. Effect of AN on Diopside phase formation is investigated. The adiabatic flame temperatures are calculated theoretically for varying amount of AN according to thermodynamic concept and correlated with the observed flame temperatures. A “Multi channel thermocouple setup connected to computer interfaced Keithley multi voltmeter 2700” is used to monitor the thermal events during the process. An interpretation based on maximum combustion temperature and the amount of gases produced during reaction for various AN compositions has been proposed for the nature of combustion and its correlation with the characteristics of as synthesized powder. These powders are characterized by XRD, SEM showing that the powders are composed of polycrystalline oxides with crystallite size of 58nm to 74nm.

Postive seedling-shrub relationships in natural regeneration of ponderosa pine

Treesearch

Christopher R. Keyes; Douglas A. Maguire

2005-01-01

An understanding of natural regeneration processes, and the stand structural features that influence those processes, is vital to attaining goals associated with natural regeneration. This paper discusses natural regeneration concepts and the interactions that occur between shrubs and natural regeneration of ponderosa pine. The interactions observed recently in a...

Modelling of the acid-base properties of natural and synthetic adsorbent materials used for heavy metal removal from aqueous solutions.

PubMed

Pagnanelli, Francesca; Vegliò, Francesco; Toro, Luigi

2004-02-01

In this paper a comparison about kinetic behaviour, acid-base properties and copper removal capacities was carried out between two different adsorbent materials used for heavy metal removal from aqueous solutions: an aminodiacetic chelating resin as commercial product (Lewatit TP207) and a lyophilised bacterial biomass of Sphaerotilus natans. The acid-base properties of a S. natans cell suspension were well described by simplified mechanistic models without electrostatic corrections considering two kinds of weakly acidic active sites. In particular the introduction of two-peak distribution function for the proton affinity constants allows a better representation of the experimental data reproducing the site heterogeneity. A priori knowledge about resin functional groups (aminodiacetic groups) is the base for preliminary simulations of titration curve assuming a Donnan gel structure for the resin phase considered as a concentrated aqueous solution of aminodiacetic acid (ADA). Departures from experimental and simulated data can be interpreted by considering the heterogeneity of the functional groups and the effect of ionic concentration in the resin phase. Two-site continuous model describes adequately the experimental data. Moreover the values of apparent protonation constants (as adjustable parameters found by non-linear regression) are very near to the apparent constants evaluated by a Donnan model assuming the intrinsic constants in resin phase equal to the equilibrium constants in aqueous solution of ADA and considering the amphoteric nature of active sites for the evaluation of counter-ion concentration in the resin phase. Copper removal outlined the strong affinity of the active groups of the resin for this ion in solution compared to the S. natans biomass according to the complexation constants between aminodiacetic and mono-carboxylic groups and copper ions.

Inorganic and Protein Crystal Assembly in Solutions

NASA Technical Reports Server (NTRS)

Chernov, A. A.

2005-01-01

The basic kinetic and thermodynamic concepts of crystal growth will be revisited in view of recent AFM and interferometric findings. These concepts are as follows: 1) The Kossel crystal model that allows only one kink type on the crystal surface. The modern theory is developed overwhelmingly for the Kessel model; 2) Presumption that intensive step fluctuations maintain kink density sufficiently high to allow applicability of Gibbs-Thomson law; 3) Common experience that unlimited step bunching (morphological instability) during layer growth from solutions and supercooled melts always takes place if the step flow direction coincides with that of the fluid.

A Conceptual Characterization of Online Videos Explaining Natural Selection

NASA Astrophysics Data System (ADS)

Bohlin, Gustav; Göransson, Andreas; Höst, Gunnar E.; Tibell, Lena A. E.

2017-11-01

Educational videos on the Internet comprise a vast and highly diverse source of information. Online search engines facilitate access to numerous videos claiming to explain natural selection, but little is known about the degree to which the video content match key evolutionary content identified as important in evolution education research. In this study, we therefore analyzed the content of 60 videos accessed through the Internet, using a criteria catalog with 38 operationalized variables derived from research literature. The variables were sorted into four categories: (a) key concepts (e.g. limited resources and inherited variation), (b) threshold concepts (abstract concepts with a transforming and integrative function), (c) misconceptions (e.g. that evolution is driven by need), and (d) organismal context (e.g. animal or plant). The results indicate that some concepts are frequently communicated, and certain taxa are commonly used to illustrate concepts, while others are seldom included. In addition, evolutionary phenomena at small temporal and spatial scales, such as subcellular processes, are rarely covered. Rather, the focus is on population-level events over time scales spanning years or longer. This is consistent with an observed lack of explanations regarding how randomly occurring mutations provide the basis for variation (and thus natural selection). The findings imply, among other things, that some components of natural selection warrant far more attention in biology teaching and science education research.

Security and Dependability Solutions for Web Services and Workflows

NASA Astrophysics Data System (ADS)

Kokolakis, Spyros; Rizomiliotis, Panagiotis; Benameur, Azzedine; Sinha, Smriti Kumar

In this chapter we present an innovative approach towards the design and application of Security and Dependability (S&D) solutions for Web services and service-based workflows. Recently, several standards have been published that prescribe S&D solutions for Web services, e.g. OASIS WS-Security. However,the application of these solutions in specific contexts has been proven problematic. We propose a new framework for the application of such solutions based on the SERENITY S&D Pattern concept. An S&D Pattern comprises all the necessary information for the implementation, verification, deployment, and active monitoring of an S&D Solution. Thus, system developers may rely on proven solutions that are dynamically deployed and monitored by the Serenity Runtime Framework. Finally, we further extend this approach to cover the case of executable workflows which are realised through the orchestration of Web services.

The influence of authentic scientific research experiences on teachers' conceptions of the nature of science (NOS) and their NOS teaching practices

NASA Astrophysics Data System (ADS)

Moriarty, Meghan A.

This study explored the influence of teachers' authentic scientific research experiences (ASREs) on teachers' conceptions of the nature of science (NOS) and teachers' NOS instruction. Twelve high school biology teachers participated in this study. Six of the participants had authentic scientific research experience (ASRE) and six had not participated in authentic scientific research. Data included background surveys, modified Views of the Nature of Science (VNOS) questionnaires, interviews, and teaching observations. Data was coded based on the eight NOS understandings outlined in 2013 in the Next Generation Science Standards (NGSS). Evidence from this study indicates participating in authentic scientific research as a member of a scientific community has dual benefits of enabling high school science teachers with informed understandings of the NOS and positioning them to teach with the NOS. However, these benefits do not always result from an ASRE. If the nature of the ASRE is limited, then it may limit teachers' NOS understandings and their NOS teaching practices. The results of this study suggest that participation in ASREs may be one way to improve teachers' NOS understandings and teaching practices if the experiences themselves offer a comprehensive view of the NOS. Because ASREs and other science learning experiences do not always offer such experiences, pre-service teacher education and professional development opportunities may engage science teachers in two ways: (1) becoming part of a scientific community may enable them to teach with NOS and (2) being reflective about what being a scientist means may improve teachers' NOS understandings and better position them to teach about NOS.. Keywords: nature of science, authentic scientific research experiences, Next Generation Science Standards, teaching about NOS, teaching with NOS.

Microbiological quality of natural waters.

PubMed

Borrego, J J; Figueras, M J

1997-12-01

Several aspects of the microbiological quality of natural waters, especially recreational waters, have been reviewed. The importance of the water as a vehicle and/or a reservoir of human pathogenic microorganisms is also discussed. In addition, the concepts, types and techniques of microbial indicator and index microorganisms are established. The most important differences between faecal streptococci and enterococci have been discussed, defining the concept and species included. In addition, we have revised the main alternative indicators used to measure the water quality.

Students' conceptions of evidence during a university introductory forensic science course

NASA Astrophysics Data System (ADS)

Yeshion, Theodore Elliot

Students' Conceptions of Science, Scientific Evidence, and Forensic Evidence during a University Introductory Forensic Science Course This study was designed to examine and understand what conceptions undergraduate students taking an introductory forensic science course had about scientific evidence. Because the relationships between the nature of science, the nature of evidence, and the nature of forensic evidence are not well understood in the science education literature, this study sought to understand how these concepts interact and affect students' understanding of scientific evidence. Four participants were purposefully selected for this study from among 89 students enrolled in two sections of an introductory forensic science course taught during the fall 2005 semester. Of the 89 students, 84 were criminal justice majors with minimal science background and five were chemistry majors with academic backgrounds in the natural and physical sciences. All 89 students completed a biographical data sheet and a pre-instruction Likert scale survey consisting of twenty questions relating to the nature of scientific evidence. An evaluation of these two documents resulted in a purposeful selection of four varied student participants, each of whom was interviewed three times throughout the semester about the nature of science, the nature of evidence, and the nature of forensic evidence. The same survey was administered to the participants again at the end of the semester-long course. This study examined students' assumptions, prior knowledge, their understanding of scientific inference, scientific theory, and methodology. Examination of the data found few differences with regard to how the criminal justice majors and the chemistry majors responded to interview questions about forensic evidence. There were qualitative differences, however, when the same participants answered interview questions relating to traditional scientific evidence. Furthermore, suggestions are

Changing Preservice Science Teachers' Views of Nature of Science: Why Some Conceptions May be More Easily Altered than Others

NASA Astrophysics Data System (ADS)

Mesci, Gunkut; Schwartz, Renee'S.

2017-04-01

The purpose of this study was to assess preservice teachers' views of Nature of Science (NOS), identify aspects that were challenging for conceptual change, and explore reasons why. This study particularly focused on why and how some concepts of NOS may be more easily altered than others. Fourteen preservice science teachers enrolled in a NOS and Science Inquiry course participated in this study. Data were collected by using a pre/post format with the Views of Nature of Science questionnaire (VNOS-270), the Views of Scientific Inquiry questionnaire (VOSI-270), follow-up interviews, and classroom artifacts. The results indicated that most students initially held naïve views about certain aspects of NOS like tentativeness and subjectivity. By the end of the semester, almost all students dramatically improved their understanding about almost all aspects of NOS. However, several students still struggled with certain aspects like the differences between scientific theory and law, tentativeness, and socio-cultural embeddedness. Results suggested that instructional, motivational, and socio-cultural factors may influence if and how students changed their views about targeted NOS aspects. Students thought that classroom activities, discussions, and readings were most helpful to improve their views about NOS. The findings from the research have the potential to translate as practical advice for teachers, science educators, and future researchers.

A Qualitative Study Examining the Exclusive Use of Primary Literature in a Special Topics Biology Course: Improving Conceptions about the Nature of Science and Boosting Confidence in Approaching Original Scientific Research

ERIC Educational Resources Information Center

Carter, B. Elijah; Wiles, Jason R.

2017-01-01

This qualitative study explores the experiences of six students enrolled in a special topics biology class that exclusively used primary literature as course material. Nature of science (NOS) conceptions have been linked to students' attitudes toward scientific subjects, but there has been little research specifically exploring the effects of…

The cultural politics of mining and natural disaster in Indonesia: by fire and sword.

PubMed

Lewis, Jeff; Lewis, Belinda

2017-01-01

Natural disasters are inevitably the outcome of cultural agonisms. The cultural politics of natural disasters are shaped by competing claims and conceptions of 'nature'. Recent disasters in Indonesia are directly linked to these contending conceptions and the ways in which different social groups imagine risk and reward. The Sidoarjo volcanic mudflow of 2006 represents a volatile and violent exemplar of contending cultural and economic claims. Like other disasters in Indonesia and elsewhere in the developing world, this 'natural' disaster is characterised by differing conceptions of 'nature' as cultural tradition, divine force, and natural resource. A new extractive project in East Java is exhibiting similar economic and cultural agonisms, particularly around the notion of development, environment, self-determination, and tradition. This paper examines the 'disputes over meaning' associated with natural disasters in contemporary societies, and the ways in which they are related to human culture, social organisation, and hierarchical systems of violence. © 2017 The Author(s). Disasters © Overseas Development Institute, 2017.

Assessing Young Children's Social Concept Development.

ERIC Educational Resources Information Center

Stanley, William B.; And Others

This study investigated a number of questions regarding the nature of social concept development in young children. Subjects were 64 kindergarten children and 65 first grade public school students from lower to upper middle class socioeconomic levels, of whom 66 were male, 63 were female, 78 were Caucasian, and 51 were black. Two assessment…

The Formation of Initial Components of Number Concepts in Mexican Children

ERIC Educational Resources Information Center

Solovieva, Yulia; Quintanar, Luis; Ortiz, Gerardo

2012-01-01

The initial formation of number concept represents one of the essential aspects of learning mathematics at the primary school. Children commonly show strong difficulties and absence of comprehension of symbolic and abstract nature of concept of number. The objective of the present study was to show the effectiveness of original method for…

Solving Cordelia's Dilemma: Threshold Concepts within a Punctuated Model of Learning

ERIC Educational Resources Information Center

Kinchin, Ian M.

2010-01-01

The consideration of threshold concepts is offered in the context of biological education as a theoretical framework that may have utility in the teaching and learning of biology at all levels. Threshold concepts may provide a mechanism to explain the observed punctuated nature of conceptual change. This perspective raises the profile of periods…

Multilingual natural language generation as part of a medical terminology server.

PubMed

Wagner, J C; Solomon, W D; Michel, P A; Juge, C; Baud, R H; Rector, A L; Scherrer, J R

1995-01-01

Re-usable and sharable, and therefore language-independent concept models are of increasing importance in the medical domain. The GALEN project (Generalized Architecture for Languages Encyclopedias and Nomenclatures in Medicine) aims at developing language-independent concept representation systems as the foundations for the next generation of multilingual coding systems. For use within clinical applications, the content of the model has to be mapped to natural language. A so-called Multilingual Information Module (MM) establishes the link between the language-independent concept model and different natural languages. This text generation software must be versatile enough to cope at the same time with different languages and with different parts of a compositional model. It has to meet, on the one hand, the properties of the language as used in the medical domain and, on the other hand, the specific characteristics of the underlying model and its representation formalism. We propose a semantic-oriented approach to natural language generation that is based on linguistic annotations to a concept model. This approach is realized as an integral part of a Terminology Server, built around the concept model and offering different terminological services for clinical applications.

The Natural Neighbour Radial Point Interpolation Meshless Method Applied to the Non-Linear Analysis

NASA Astrophysics Data System (ADS)

Dinis, L. M. J. S.; Jorge, R. M. Natal; Belinha, J.

2011-05-01

In this work the Natural Neighbour Radial Point Interpolation Method (NNRPIM), is extended to large deformation analysis of elastic and elasto-plastic structures. The NNPRIM uses the Natural Neighbour concept in order to enforce the nodal connectivity and to create a node-depending background mesh, used in the numerical integration of the NNRPIM interpolation functions. Unlike the FEM, where geometrical restrictions on elements are imposed for the convergence of the method, in the NNRPIM there are no such restrictions, which permits a random node distribution for the discretized problem. The NNRPIM interpolation functions, used in the Galerkin weak form, are constructed using the Radial Point Interpolators, with some differences that modify the method performance. In the construction of the NNRPIM interpolation functions no polynomial base is required and the used Radial Basis Function (RBF) is the Multiquadric RBF. The NNRPIM interpolation functions posses the delta Kronecker property, which simplify the imposition of the natural and essential boundary conditions. One of the scopes of this work is to present the validation the NNRPIM in the large-deformation elasto-plastic analysis, thus the used non-linear solution algorithm is the Newton-Rapson initial stiffness method and the efficient "forward-Euler" procedure is used in order to return the stress state to the yield surface. Several non-linear examples, exhibiting elastic and elasto-plastic material properties, are studied to demonstrate the effectiveness of the method. The numerical results indicated that NNRPIM handles large material distortion effectively and provides an accurate solution under large deformation.

Bosonized Supersymmetric Sawada-Kotera Equations: Symmetries and Exact Solutions

NASA Astrophysics Data System (ADS)

Liu, Ping; Zeng, Bao-Qing; Liu, Li-Ming

2015-04-01

The Bosonized Supersymmetric Sawada-Kotera (BSSK) system is constructed by applying bosonization method to a Supersymmetric Sawada-Kotera system in this paper. The symmetries on the BSSK equations are researched and the calculation shows that the BSSK equations are invariant under the scaling transformations, the space-time translations and Galilean boosts. The one-parameter invariant subgroups and the corresponding invariant solutions are researched for the BSSK equations. Four types of reduction equations and similarity solutions are proposed. Period Cnoidal wave solutions, dark solitary wave solutions and bright solitary wave solutions of the BSSK equations are demonstrated and some evolution curves of the exact solutions are figured out. Supported by the National Natural Science Foundation of China under Grant No. 11305031, the Natural Science Foundation of Guangdong Province under Grant No. S2013010011546, the Science and Technology Project Foundation of Zhongshan under Grant Nos. 2013A3FC0264 and 2013A3FC0334, and Training Programme Foundation for Outstanding Young Teachers in Higher Education Institutions of Guangdong Province under Grant No. Yq2013205

Concept of adaptability in space modules.

PubMed

Cooper, M

1990-10-01

The space program is aiming towards the permanent use of space; to build and establish an orbital space station, a Moon base and depart to Mars and beyond. We must look after the total independency from the Earth's natural resources and work in the design of a modular space base in which each module is capable of duplicating one natural process, and that all these modules in combination take us to conceive a space base capable of sustaining life. Every area of human knowledge must be involved. This modular concept will let us see other space goals as extensions of the primary project. The basic technology has to be defined, then relatively minor adjustments will let us reach new objectives such as a first approach for a lunar base and for a Mars manned mission. This concept aims towards an open technology in which standards and recommendations will be created to assemble huge space bases and spaceships from specific modules that perform certain functions, that in combination will let us reach the status of permanent use and exploration of space.

Basic taxation of natural resources

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

Not Available

1986-01-01

This book contains 19 selections. Some of the titles are: Introduction to taxation and natural resources; The economic interest concept; Oil and gas exploration and development expenditures; Percentage depletion for oil and gas; and Mine reclamation and closing expenses.

The nature of dissection: Exploring student conceptions

NASA Astrophysics Data System (ADS)

York, Katharine

The model of conceptual change in science describes the process of learning as a complete restructuring of knowledge, when learners discover or are shown more plausible, intelligent alternatives to existing conceptions. Emotions have been acknowledged as part of a learner's conceptual ecology, but the effects of emotions on learning have yet to be described. This research was conducted to examine the role that emotions have on learning for thirteen high school students, as they dissected cats in a Human Anatomy and Physiology class. The project also investigated whether a student's emotional reactions may be used to develop a sense of connectedness with the nonhuman world, which is defined as ecological literacy. This study utilized a grounded theory approach, in which student responses to interviews were the primary source of data. Interviews were transcribed, and responses were coded according to a constant comparative method of analysis. Responses were compared with the four conditions necessary for conceptual change to occur, and also to five principles of ecological literacy. Students who had negative reactions to dissection participated less in the activity, and demonstrated less conceptual change. Two female students showed the strongest emotional reactions to dissection, and also the lowest amount of conceptual change. One male student also had strong negative reactions to death, and showed no conceptual change. The dissection experiences of the students in this study did not generally reflect ecological principles. The two students whose emotional reactions to dissection were the most negative demonstrated the highest degree of ecological literacy. These results provide empirical evidence of the effects that emotions have on learning, and also supports the opinions of educators who do not favor dissection, because it does not teach students to respect all forms of life.

Perception and understanding of invasive alien species issues by nature conservation and horticulture professionals in Belgium.

PubMed

Vanderhoeven, Sonia; Piqueray, Julien; Halford, Mathieu; Nulens, Greet; Vincke, Jan; Mahy, Grégory

2011-03-01

We conducted a survey to determine how two professional sectors in Belgium, horticulture professionals and nature reserve managers (those directly involved in conservation), view the issues associated with invasive plant species. We developed and utilized a questionnaire that addressed the themes of awareness, concept and use of language, availability of information, impacts and, finally, control and available solutions. Using co-inertia analyses, we tested to what extent the perception of invasive alien species (IAS) was dependent upon the perception of Nature in general. Only forty-two percent of respondent horticulture professionals and eighty-two percent of nature reserve managers had a general knowledge of IAS. Many individuals in both target groups nonetheless had an accurate understanding of the scientific issues. Our results therefore suggest that the manner in which individuals within the two groups view, or perceive, the IAS issue was more the result of lack of information than simply biased perceptions of target groups. Though IAS perceptions by the two groups diverged, they were on par with how they viewed Nature in general. The descriptions of IAS by participants converged with the ideas and concepts frequently found in the scientific literature. Both managers and horticulture professionals expressed a strong willingness to participate in programs designed to prevent the spread of, and damage caused by, IAS. Despite this, the continued commercial availability of many invasive species highlighted the necessity to use both mandatory and voluntary approaches to reduce their re-introduction and spread. The results of this study provide stakeholders and conservation managers with practical information on which communication and management strategies can be based.