884 resultados para Concept inventories
Resumo:
Misconceptions exist in all fields of learning and develop through a person’s preconception of how the world works. Students with misconceptions in chemical engineering are not capable of correctly transferring knowledge to a new situation and will likely arrive at an incorrect solution. The purpose of this thesis was to repair misconceptions in thermodynamics by using inquiry-based activities. Inquiry-based learning is a method of teaching that involves hands-on learning and self-discovery. Previous work has shown inquiry-based methods result in better conceptual understanding by students relative to traditional lectures. The thermodynamics activities were designed to guide students towards the correct conceptual understanding through observing a preconception fail to hold up through an experiment or simulation. The developed activities focus on the following topics in thermodynamics: “internal energy versus enthalpy”, “equilibrium versus steady state”, and “entropy”. For each topic, two activities were designed to clarify the concept and assure it was properly grasped. Each activity was coupled with an instructions packet containing experimental procedure as well as pre- and post-analysis questions, which were used to analyze the effect of the activities on the students’ responses. Concept inventories were used to monitor students’ conceptual understanding at the beginning and end of the semester. The results did not show a statistically significant increase in the overall concept inventory scores for students who performed the activities compared to traditional learning. There was a statistically significant increase in concept area scores for “internal energy versus enthalpy” and “equilibrium versus steady state”. Although there was not a significant increase in concept inventory scores for “entropy”, written analyses showed most students’ misconceptions were repaired. Students transferred knowledge effectively and retained most of the information in the concept areas of “internal energy versus enthalpy” and “equilibrium versus steady state”.
Resumo:
Engineering students continue to develop and show misconceptions due to prior knowledge and experiences (Miller, Streveler, Olds, Chi, Nelson, & Geist, 2007). Misconceptions have been documented in students’ understanding of heat transfer(Krause, Decker, Niska, Alford, & Griffin, 2003) by concept inventories (e.g., Jacobi,Martin, Mitchell, & Newell, 2003; Nottis, Prince, Vigeant, Nelson, & Hartsock, 2009). Students’ conceptual understanding has also been shown to vary by grade point average (Nottis et al., 2009). Inquiry-based activities (Nottis, Prince, & Vigeant, 2010) haveshown some success over traditional instructional methods (Tasoglu & Bakac, 2010) in altering misconceptions. The purpose of the current study was to determine whether undergraduate engineering students’ understanding of heat transfer concepts significantly changed after instruction with eight inquiry-based activities (Prince & Felder, 2007) supplementing instruction and whether students’ self reported GPA and prior knowledge, as measured by completion of specific engineering courses, affected these changes. The Heat and Energy Concept Inventory (Prince, Vigeant, & Nottis, 2010) was used to assess conceptual understanding. It was found that conceptual understanding significantly increased from pre- to post-test. It was also found that GPA had an effect on conceptual understanding of heat transfer; significant differences were found in post-test scores onthe concept inventory between GPA groups. However, there were mixed results when courses previously taken were analyzed. Future research should strive to analyze how prior knowledge effects conceptual understanding and aim to reduce the limitations of the current study such as, sampling method and methods of measuring GPA and priorknowledge.
Resumo:
Kaupintavaraston käyttäminen yrityksen hankintalogistiikassa vapauttaa varastoihin sitoutuneita pääomia, parantaa palveluastetta ja syventää asiakkaan ja toimittajan välistä yhteistyötä. Tulevaisuudessa menetelmää tullaan käyttämään laajenevassa määrin keinona logistisen kilpailukyvyn ja kustannustehokkuuden parantamisessa.Tämän työn tavoitteena oli selvittää yrityksen hankintalogistiikkaan soveltuvan kaupintavarastontoiminnan vaatimukset ja kehittää konsernin eri toimialoille yhtenäinen konsepti. Selvitys aloitettiin tutkimalla kirjallisuutta ja yrityksen asiakkaalla käytössä olevaa kaupintavarastoratkaisua, jonka jälkeen käytännön ongelmia kartoitettiin pilottiprojektin avulla.Tuloksena saatiin konsepti, jossa on käsitelty kaupintavaraston käyttöönottoa varten tarvittavat erityispiirteet kansainvälisessä kaupankäynnissä. Toimittajien ja toimitusketjujen erilaisista rakenteista johtuen yksityiskohdat on mietittävä jokaisen toimittajan kanssa erikseen.
Resumo:
The following research paper was a study into change in student academic and general self-concept with increase in grade level and age# The majority of literature found by this researcher dealt with self-concept and its relationship to achievement and interactions with others, Review, then, was in these two areas-particularily within the academic setting, but outside of it as well. It wrs hypothesized that there would be a decrease in both academic and general student self-concept with increase in grade level and age. Self-Appraisal inventories, measuring general and academic selfconcept, and Inferential Self-Reports, measuring only academic selfconcept, were the instruments used* Subjects were students, Trade 1 to 13, and ranging in age from 5 to 21„ Although al] Self-Appraisal inventories and all Self-1?eports were very similar, they differed according to three Grade levels: Primary (Grades 1 to 3)> Intermediate (Grades L to 8), and Secondary (Grades 9 to 13) • Students in the Primary division received only their respective Self-Appraisal inventory, while others v/ere administered both inventories designed for their grade level. Scores on the inventories were computed to percents and then mean percents were arrived at for epch grade, each of the three grade levels, each age, and each of three age intervals. In all of these instances Spearman1 s rank order coefficients (!lpff) were calculated and significance, at the *05 level, was determined by referring to a table of critical values for one-tailed tests* Similarily fftff scores were computed, but only for individual grades and ages, and significance was determined at the *0b level* In only one instance, the General Dimension for individual grades, was significance of overall decrease found* Consequently the hypotheses put forth did not gain support* The fltff scores, however, revealed some isolated significant changes for the Academic Dimension, which were generally decreases in mean percents from the last grade of one level to the first grade of the next* For age mean percents, significant changes generally took place at early (5 or 6) and late (20 or 21) ages* A number of reasons for the results were presented and were generally based upon the studentfs encounters, or lack of encounters, with achievement or success* No definite conclusions, relevant to the hypotheses stated^ could be made, although a number of isolated ones were drawn on the basis of significant fltff scores* As well, mention was made of the possible trends or tendencies that were revealed by the results, but that could not, or were not, proven significant by "t's11 or "p's"* Teaching methods stressing improvement in academic, as well as socially related, situations, were recommended and a model teaching approach was presented in Appendix B#
Resumo:
Resource specialisation, although a fundamental component of ecological theory, is employed in disparate ways. Most definitions derive from simple counts of resource species. We build on recent advances in ecophylogenetics and null model analysis to propose a concept of specialisation that comprises affinities among resources as well as their co-occurrence with consumers. In the distance-based specialisation index (DSI), specialisation is measured as relatedness (phylogenetic or otherwise) of resources, scaled by the null expectation of random use of locally available resources. Thus, specialists use significantly clustered sets of resources, whereas generalists use over-dispersed resources. Intermediate species are classed as indiscriminate consumers. The effectiveness of this approach was assessed with differentially restricted null models, applied to a data set of 168 herbivorous insect species and their hosts. Incorporation of plant relatedness and relative abundance greatly improved specialisation measures compared to taxon counts or simpler null models, which overestimate the fraction of specialists, a problem compounded by insufficient sampling effort. This framework disambiguates the concept of specialisation with an explicit measure applicable to any mode of affinity among resource classes, and is also linked to ecological and evolutionary processes. This will enable a more rigorous deployment of ecological specialisation in empirical and theoretical studies.
Resumo:
Conventional tilted implants are used in oral rehabilitation for heavily absorbed maxilla to avoid bone grafts; however, few research studies evaluate the biomechanical behavior when different angulations of the implants are used. The aim of this study was evaluate, trough photoelastic method, two different angulations and length of the cantilever in fixed implant-supported maxillary complete dentures. Two groups were evaluated: G15 (distal tilted implants 15°) and G35 (distal tilted implants 35°) n = 6. For each model, 2 distal tilted implants (3.5 x 15 mm long cylindrical cone) and 2 parallel tilted implants in the anterior region (3.5 x 10 mm) were installed. Photoelastic models were submitted to three vertical load tests: in the end of cantilever, in the last pillar and in the all pillars at the same time. We obtained the shear stress by Fringes software and found values for total, cervical and apical stress. The quantitative analysis was performed using the Student tests and Mann-Whitney test; p ≥ 0.05. There is no difference between G15 and G35 for total stress regardless of load type. Analyzing the apical region, G35 reduced strain values considering the distal loads (in the cantilever p = 0.03 and in the last pillar p = 0.02), without increasing the stress level in the cervical region. Considering the load in all pillars, G35 showed higher stress concentration in the cervical region (p = 0.04). For distal loads, G15 showed increase of tension in the apical region, while for load in all pillars, G35 inclination increases stress values in the cervical region.
Resumo:
The concept of recovery has been described in papers as a state of psychic, physical and social recuperation of day-to-day functions. The scope of this article is to analyze the concepts of the term in different research methodologies and the paradigmatic evolution of the recovery concept. Systematic bibliographical research was conducted in the Pubmed database using the words recovery + schizophrenia limited to freely available full papers published in the previous two years. Nineteen papers were analyzed. The majority of the papers sought associations between characteristic data and recovery; few papers discussed the concept in a way to distinguish it from other words like cure or rehabilitation. Recovery as a state in which people with severe mental illness can feel like the creators of their own itinerary tend to be found in qualitative studies and in bibliographic reviews in which the meaning of recovery is not related to the lack of symptoms and tends to prioritize how participative the life of an individual can be despite the disease. Some quantitative studies detect this conceptual difference. In qualitative research there is an increase in the concept of recovery and in ways of promoting it.
Resumo:
In this work, we employed the effective coordination concept to study the local environments of the Ge, Sb, and Te atoms in the Ge(m)Sb(2n)Te(m+3n) compounds. From our calculations and analysis, we found an average effective coordination number (ECN) reduction of 1.59, 1.42, and 1.37, for the Ge, Sb, Te atoms in the phase transition from crystalline, ECN=5.55 (Ge), 5.73 (Sb), 4.37 (Te), to the amorphous phase, ECN=3.96 (Ge), 4.31 (Sb), 3.09 (Te), for the Ge(2)Sb(2)Te(5) composition. Similar changes are observed for other compositions. Thus, our results indicate that the coordination changes from the crystalline to amorphous phase are not large as previously assumed in the literature, i.e., from sixfold to fourfold for Ge, which can contribute to obtain a better understanding of the crystalline to amorphous phase transition. (C) 2011 American Institute of Physics. [doi:10.1063/1.3533422]
Resumo:
The aim of this study was to develop the concept of the dignified death of children in Brazilian pediatric intensive care units (PICUs). The Hybrid Model for Concept Development was used to develop a conceptual structure of dignified death in PICUs in an attempt to define the concept. The fieldwork study was carried out by means of in-depth interviews with nine nurses and seven physicians working in PICUs. Not unexpectedly, the concept of dignified death was found to be a complex phenomenon involving aspects related to decisions made by the multidisciplinary team as well as those related to care of the child and the family. Knowledge of the concept`s dimensions can promote reflection on the part of healthcare professionals regarding the values and beliefs underlying their conduct in end-of-life situations. Our hope is that this study may contribute to theoretic and methodological development in the area of end-of-life care.
Resumo:
Objective The study analyzes the possibility of incorporating health promotion measures into the work processes of Family Health Program teams at a primary health care clinic in Brazil. Design and Sample We used the participatory research concept developed in 1968 by Freire. The study sample comprised the end-users of the health care system, together with 3 multidisciplinary teams. A total of 77 health care users and 55 health professionals participated in the study. Measures Culture circles composed of health care professionals, and users from different areas investigated generative topics, encoded/decoded topics, and engaged in critical probing for clarification. Topics affecting quality of life and health were heuristically evaluated. Results Although most topics were related to changing the focus of health care facilities, some were related to subsidizing community-based interventions, improving environmental strategies, individual skills, and public policies. Incorporating the novel health promotion measures and creating an expanded full-treatment clinic are important steps toward that goal. Conclusions Topics that can stimulate dialogue among the members of the culture circles include creating an environment of closer cultural contact, with repercussions for work processes, family health models, and general health models, as well as the inclusion of social aspects in the decision-making processes related to health issues that affect the living conditions of the population.
Resumo:
In this study, the innovation approach is used to estimate the measurement total error associated with power system state estimation. This is required because the power system equations are very much correlated with each other and as a consequence part of the measurements errors is masked. For that purpose an index, innovation index (II), which provides the quantity of new information a measurement contains is proposed. A critical measurement is the limit case of a measurement with low II, it has a zero II index and its error is totally masked. In other words, that measurement does not bring any innovation for the gross error test. Using the II of a measurement, the masked gross error by the state estimation is recovered; then the total gross error of that measurement is composed. Instead of the classical normalised measurement residual amplitude, the corresponding normalised composed measurement residual amplitude is used in the gross error detection and identification test, but with m degrees of freedom. The gross error processing turns out to be very simple to implement, requiring only few adaptations to the existing state estimation software. The IEEE-14 bus system is used to validate the proposed gross error detection and identification test.
Exploring the potential of functionally graded materials concept for the development of fiber cement
Resumo:
In this study we establish the concept of functionally graded fiber cement. We discuss the use of statistical mixture designs to choose formulations and present ideas for the production of functionally graded fiber cement components for Hatschek machines. The feasibility of producing functionally graded fiber cement by grading PVA fiber content has been experimentally evaluated. Thermogravimetric analysis (TG) was employed to assess fiber distribution profiles and four-point bending tests were applied to evaluate the mechanical performance of both conventional and graded composites. The results show that grading PVA fiber content is an effective way to produce functionally graded fiber cement, which allows for a reduction of the total fiber volume without a significant reduction on modulus of rupture of composite. TG tests were found adequate to assess the fiber content at different points in functionally graded fiber cements. (C) 2009 Elsevier Ltd. All rights reserved.
Resumo:
This paper presents the development of a prototype of a tubular linear induction motor applied to onshore oil exploitation, named MAT AE OS (which is the Portuguese acronym for Tubular Asynchronous Motor for Onshore Oil Exploitation). The function of this motor is to directly drive the sucker-rod pump installed in the down hole of the oil well. Considering the drawbacks and operational costs of the conventional oil extraction method, which is based on the walking beam and rod, string system, the developed prototype is intended to become a feasible alternative from both technical and economic points of view. At the present time, the MAT AE OS prototype is installed in a test bench at the Applied Electromagnetism Laboratory at the Escola Politecnica da Universidade de Sao Paulo. The complete testing system is controlled and supervised by special software, enabling good flexibility in operation, data acquisition, and performance analysis. The test results indicate that the motor develops a constant lift force along the pumping cycle, as shown by the measured dynamometric charts. Also, the evaluated electromechanical performance seems to be superior to that obtained by the traditional method. The system utilizing the MAT AE OS prototype allows the complete elimination of the rod string sets required by the conventional equipment, indicating that the new system may advantageously replace the surface mechanical components presently utilized.
Resumo:
Application of the thermal sum concept was developed to determine the optimal harvesting stage of new banana hybrids to be grown for export. It was tested on two triploid hybrid bananas, FlhorBan 916 (F916) and FlhorBan 918 (F918), created by CIRAD`s banana breeding programme, using two different approaches. The first approach was used with F916 and involved calculating the base temperature of bunches sampled at two sites at the ripening stage, and then determining the thermal sum at which the stage of maturity would be identical to that of the control Cavendish export banana. The second approach was used to assess the harvest stage of F918 and involved calculating the two thermal parameters directly, but using more plants and a longer period. Using the linear regression model, the estimated thermal parameters were a thermal sum of 680 degree-days (dd) at a base temperature of 17.0 degrees C for cv. F916, and 970 dd at 13.9 degrees C for cv. F918. This easy-to-use method provides quick and reliable calculations of the two thermal parameters required at a specific harvesting stage for a given banana variety in tropical climate conditions. Determining these two values is an essential step for gaining insight into the agronomic features of a new variety and its potential for export. (C) 2011 Elsevier B.V. All rights reserved.