La importancia de los relatos en los contextos educativos: reflexiones desde los aportes de Bruner

En este trabajo se retoman los aportes de Jerome Bruner acerca del papel de los relatos dentro de la cultura, y por lo tanto, dentro de la educación. El escrito se estructura en cuatro partes. En el primer apartado, se argumenta en torno a la importancia de los relatos en la construcción de la identidad. En segundo lugar, se hace referencia a cómo los relatos intervienen en la formación de los vínculos sociales. En el tercer apartado se considera la relación entre los relatos o narrativa y la educación. Finalmente, se reflexiona acerca de la relevancia de atender a los relatos en las instituciones educativas y se abren nuevos interrogantes acerca de cómo y por qué los relatos pueden ser una herramienta interesante para trabajar en las aulas.Fil: Vaja, Arabela Beatriz. Universidad Nacional de Río Cuarto. Facultad de Ciencias Humanas. Departamento de Ciencias de la Educación; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Dissimilar metal joining of stainless steel and titanium using copper as transition metal

Joining of stainless steel and titanium dissimilar metal combination has a specific interest in the nuclear industry. Due to the metallurgical incompatibility, it has been very difficult to produce reliable joints between these metals due to the formation of FeTi and Fe2Ti types of intermetallic compounds. The metallurgical incompatibility between both materials is enhanced by the time–temperature profile of the welding process used. Brittle intermetallics (IMCs) are formed during Fe–Ti welding (FeTi and Fe2Ti). The present study uses the low thermal heat input process cold metal transfer (CMT), when compared with conventional GMAW, to deposit a copper (Cu) bead between Ti and stainless steel. Cu is compatible with Fe, and it has a lower melting point than the two base materials. The welds were produced between AMS 4911L (Ti-6Al-4V) and AISI 316L stainless steel using a CuSi-3 welding wire. The joints produced revealed two IM layers located near the parent metals/weld interfaces. The hardness of these layers is higher than the remainder of the weld bead. Tensile tests were carried out with a maximum strength of 200 MPa, but the interfacial failure could not be avoided. Ti atomic migration was observed during experimental trials; however, the IMC formed are less brittle than FeTi, inducing higher mechanical properties.EPSR

On local quasi-convexity as a three-space property in topological abelian groups

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract:] Let X be a topological abelian group and H a subgroup of X. We find conditions under which local quasi-convexity of both H and results in the same property for X. This is true for instance if H is precompact, or if X is metrizable and H is a dually embedded subgroup which is also either discrete or bounded torsion. We also give some general principles and point out some errors we have found in the existing literature on this problem.Agencia Estatal de Investigación; MTM2013-42486-PAgencia Estatal de Investigación; MTM2016-79422-PShota Rustaveli National Science Foundation of Georgia (SRNSFG); DI-18-142

Effect of pregnancy induced hypertension on maternal and perinatal outcome at tertiary care center in Ahmedabad, Gujarat, India

Background: Pregnancy is a physiological event for utmost women. Almost 20% - 30% of the adult population and more than 5% - 8% of all pregnancies in the world suffered from hypertension (HTN) and 5% - 22% of all pregnancies have develop some kind of medical problem due to hypertensive. To study the prevalence of PIH and to find out the association of PIH with perinatal and maternal outcome.Methods: Prospective study was done among 110 cases of PIH admitted at department of obstetrics and Gynecology in B.J. Medical college, Ahmedabad during July 2005 to July 2007. Hypertension was identified based on the definition by the Australian Society of the Study of Hypertension in Pregnancy and that of the Working Group Report on High Blood Pressure in Pregnancy, which establish blood pressure levels > 140/90 mmHg or hypertension diagnosis marked on the record.Results: Almost 44% participants had mild PIH and 56% had severe PIH. Almost 32% participants had grade I changes and 29% had grade II changes. Low birth weight was found in 53% baby. Maternal complication observed in 16% participants. Out of 16 patients, highest incidence of eclampsia was observed followed by APH, DIC respectively. One incidence of maternal death also occurred. Perinatal complications were observed in 46% cases which include IUGR (60.9%), birth asphyxia (8.7%), RDS (4.3%) and perinatal death (15.2%) respectively.Conclusions: Pregnancy-induced hypertension is associated with multiple complications in the mother and baby, and particularly preterm delivery. Timely intervention of regular ANC check-up, nutrition, health education etc. can reduce the severity of PIH which lead to decrease in maternal and perinatal complications

A study of thrombocytopenia in pregnancy

Background: Thrombocytopenia is defined as low platelet count and if it is present during pregnancy can jeopardize the maternal and fetal outcome. Thrombocytopenia occurs in 6-15% of pregnancies. Causes of thrombocytopenia include gestational, idiopathic thrombocytopenia, preeclampsia, HELLP, DIC, malignancy and marrow failure. Aim of this study was to find out the common causes of thrombocytopenia in this hospital and management being used.Methods: Data was collected form those women who came to the antenatal clinic (booked) and labour room (unbooked) in the department of obstetrics and gynecology, GMERS Medical College and Hospital, Sola, Ahmedabad. Data of a total of 75 pregnant women were collected during the period of July 2018 to June 2019.Results: There were 66.67% cases of gestational thrombocytopenia, 13.33% related to preeclampsia, 8% in Eclamptic patients, 2.67% in HELLP and DIC, 6.67 in ITP, and lastly 2.67% in dengue cases. There were number of associated complication whether directly related (PPH) or part of the disorder. PPH was observed in 22.67% which is maximum among all complications. Other complications were part of major associated illness i.e. liver failure (6.67%), renal failure (5.3%), DIC (5.3%) and HELLP (8%).Conclusions: Mode of delivery was not influenced by platelet count, but for obstetric indications. Management of patients was as per the diagnosis. Single donor plasma is preferable to random donor plasma. PPH was the commonest complication and we should be wary of that

Incidence of maternal near-miss events in a tertiary care hospital of Gujarat, India

Background: Maternal near miss is said to have occurred when women presented with life threatening complication during pregnancy, child birth and within 42 days after delivery, but survive by chance or good institutional care. For identifying near-miss cases five-factor scoring system was used. In 2009 WHO working group has standardized the criteria for selecting these cases. Because maternal mortality is a rare event, it is important to study maternal near-miss as a complement to evaluate and improve the quality of obstetric care. Thus, the study was conducted with the aim of assessing the incidence and causes of maternal near-miss.Methods: A facility-based cross-sectional study was conducted in the department of obstetrics and gynecology in GMERS medical college and hospital, Sola, Ahmedabad from January 1, 2019 to August 31, 2019. All maternal near-miss cases admitted to the hospital during the study period were recruited. World Health Organization criteria were used to identify maternal near-miss cases. The number of maternal near-miss cases over one year per 1000 live births occurring during the same year was calculated to determine the incidence of maternal near-miss. Underlying and contributing causes of maternal near-miss were documented from each participant’s record.Results: During the period of study, 3235 deliveries were done at the institution while 16 cases of near-miss were identified. The prevalence of near-miss case in this study was 0.5%. Near-miss per 1000 delivery was 5%. Maternal death to near miss ratio was 1:2.67. The leading causes of maternal near miss were hypertensive disorders (62%) and haemorrhage (32%) The morbidity was high in un-booked cases.Conclusions: Maternal near miss is good alternative indicator of health care system. Efforts made toward improvement in the management of life-threatening obstetric complications could reduce the occurrence of maternal near-miss problems that occur during hospitalization

Emotions of achievement in the context of assessment: an exploratory study with university students

En este trabajo nos propusimos abordar las emociones que experimentan los estudiantes universitarios en una situación genuina de examen, en el contexto de las clases a las que habitualmente asisten. El estudio adopta una perspectiva socio-cognitiva y situada de los aprendizajes. Trabajamos con una muestra incidental (N=36) compuesta por todos los alumnos que durante el 2011 cursaron Psicología Educacional en la Universidad Nacional de Río Cuarto (Argentina). Los datos fueron recabados mediante observaciones no participantes, análisis del protocolo de evaluación, el Achievement Emotions Questionnaire y entrevistas grupales semiestructuradas. El análisis integró enfoques cualitativos y cuantitativos. Los resultados muestran características de un contexto de evaluación en toda su complejidad y las emociones experimentadas por los estudiantes en diversos momentos. Las conclusiones se agrupan en tres ejes: a) rasgos de contextos de evaluación promotores de emociones positivas, b) importancia de apelar a métodos mixtos en el estudio de las emociones, c) consideraciones para investigaciones futuras.In this paper we aim to address the emotions that university students experience in a real testing situation, in the context of the classes they regularly attend. The study adopts a socio-cognitive and situated perspective of learning. We worked with a random sample (N=36) comprised of all the students who studied Educational Psychology in 2011 in the National University of Río Cuarto (Argentina). The data was collected through non-participant observation, analysis of evaluation protocol, the Achievement Emotions Questionnaire, and semi-structured group interviews. The analysis integrated qualitative and quantitative focuses. The results revealed characteristics of a context of evaluation in all its complexity and the emotions experienced by the students in various moments. The conclusions are grouped into three categories: a) features of evaluation contexts that promote positive emotions, b) importance of appealing to mixed methods in the study of emotions, and c) considerations for future research.Fil: Paoloni, Paola Veronica Rita. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vaja, Arabela Beatriz. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Definition of an object oriented library for the dynamic simulation of advanced energy systems: methodologies, tools and application to combined ICE-ORC power plants

The present Thesis covers part of the work that has been carried out during the three year Ph.D. course in Industrial Engineering at the University of Parma. Scope of the work is developing theoretical methodologies and a full library of dynamic models that can represent the components that usually appear in energy conversion systems. The proposed library should endorse the possibility to create any desire arrangement of the studied systems, to overcome the lack of testing facilities in order to create full virtual machines capable of representing the main phenomena that occur in the real systems to get a full and deep understanding on the way they operate and respond to transients and off design operating condition. In Chapter Two an overview and classification of modeling techniques, suitable for energy systems analysis, is presented. Among the different classification criteria introduced, it is crucial to define whether state variables can be used for the considered component. This option leads to very different ways of developing the model: if the component modeled displays some “storage” capabilities (i.e. it is assumed to be able to store mass, energy, momentum, or moment of momentum) it is intended as a “state determined” system and state variables are defined through the introduction of cardinal physical laws in differential form. From a mathematical viewpoint this implies integrating in time (time is the only domain considered within this work) ordinary differential equations (ODE) expressed in term of the state variables, whose evolution hence will not depend only on the system inputs but on its complete “history”, that starts with the initialization at simulation time t=0. If the storage capabilities of the model are neglected it will be defined as “not state determined” and only algebraic equations (AE) will be introduced. Often the equations used in this case are derived from steady state performance data, gathered either from experimental investigations or by more complex model tools, thus simplifying the description of their transient behaviour as a continuous progression of steady state operating conditions. This modelling approach is known as “quasi-steady”. The models that will be created should be proper (i.e. models that achieve the accuracy required by the application with minimal complexity) scalable and flexible. The approach is followed is typical of object-oriented modeling and each realized component refers to a physical part (or a physical phenomena) of the system. Particular attention is also paid to causality, i.e. every model should be created in such a way to properly represent the cause-effect correlation between inputs and outputs. Another issue faced is the modeling environment to be chosen. After assessing some of the most widely known softwares that looked suitable for the scope, the choice has fallen on the Matlab®/Simulink® package. Simulink® is appreciated for modelling, simulation and analysis of dynamic systems by use of standard or customized blocks that allow great flexibility in model designing and are suitable for control purposes. Matlab® is exploited for its graphical and result analysis capabilities and the possibility to write specific functions which can be called during simulation. The potentialities in matrix calculation of the Matlab® language are also often exploited. In Chapter Three the complete library of components is presented. According to what seen previously the components created have been split in the two main sub-libraries depending if dealing with “state determined” or “not state determined” components. A full complete system model should comprise a proper alternation of components coming from the two libraries to guarantee a better numerical solvability of the system of equations generated and to avoid algebraic loops. The two realized libraries have been enclosed in the Simulink® library root from where the realized custom blocks can be choosen, analogously to the way the standard blocks are employed. This option not only allows easy access to the developed block in creating any new lay-out, but turns useful since the models picked up from the library, if improved or modified, extend the changes to any Simulink® lay-out where they are employed. For each component a detailed description of the inputs, outputs and state variables (if present) is provided. The realized Simulink® models are also shown along with the specific dialog windows realized to introduce model parameters. Nearly all the models are based on s-functions, which allows executing the compiled Matlab® code while Simulink® is performing the simulation of a system. The sub-library ‘state determined components’ will contain the following components:  thermal solar collectors;  single phase heat exchangers;  heat exchangers with phase change;  drums;  constant pressure combustion chambers;  rotating shafts dynamics;  General fluid Receivers;  ICE intercoolers. Among these particular emphasis is given on the models of heat exchangers. This component has been characterized through the adoption of finite volume approach where a set of differential equations, expressing the energy balances in the axial nodes, is introduced and solved numerically adopting a forward finite difference method. Peculiarity of the proposed procedure is the degree of accuracy that may be tuned by the user defining the precision of the component discretization. The approach has also been applied to model an heat exchanger with phase change (evaporator or condenser) where also mass balances are considered in the component control volumes. The ‘not state determined’ library contains the following models:  compressors;  turbines;  pumps;  valves;  heat exchangers with no thermal dynamics;  in cylinder combustion processes (in ICE). As seen the library features all the “flow control devices’ that may appear in a fluid system, such as turbines, compressors, pumps and valves. Among the elements introduced, a special one in the “ICE in-cylinder processes”. The component is based on characteristic maps that allow to know the state of gases trapped inside an ICE cylinder at the end of expansion stroke. This model will turn useful in realizing a full dynamic model of an ICE. The maps are not based on experimental data, as common practice, but are obtained by means of a specifically developed computer code that resolves the chemical equations that refer to species dissociation at chemical equilibrium. Even though it is just an approximation of the real combustion process, the procedure has been believed to be a useful way to gather information of the engine combustion processes when no (or limited) experimental data are available. In Chapter Four examples of applications of the realized models for fluid components are provided, with reference to power systems widely diffused and of known and proven design. The scope is to display the ease of creating new full models from the base component blocks, and the way to properly couple and link them together. Besides a simple example of a cogenerative micro gas turbine system, deeper insight is provided to the models of an organic Rankine power cycle and an alternative stationary internal combustion engine used for cogeneration purposes. These models will be employed for further analysis in Chapter Five. Results of simulations are presented for all the full models described under transient operating conditions inducted by some changes in the main model inputs. All the presented models have been introduced in a further Simulink® sub-library (‘complete power systems’). To be noted that the example presented are not exhaustive of the capabilities of the presented set of computer models discussed in Chapter Three, but new systems can be easily created depending on the research needs. Chapter Five show the way the developed models are intended for system design purposes. It is author’s belief that a full validated computer model for the dynamic simulation of energy systems can constitute a proper tool aimed at developing, assessing and optimizing new system design configurations, developed to increase energy conversion efficiency and reducing primary energy consumption. In this case a combined ICE-ORC system (intended for stationary applications) is proposed as solution to improve the second principle efficiency of the engine generating unit. Many configurations are proposed and discussed through a comprehensive energy and exergy analysis of the system, in order to highlight the theoretical benefits in terms of energy conversion efficiency that can be achieved in some cases. To prove the feasibility of the design and to deeply assess the mutual interactions that exist between the two prime engines, a complete dynamic model of the system has been proposed and some results, under transient operational conditions are reported. The dynamic model of the full system therefore constitute a virtual test bench for development and enhancement of the new proposed energy conversion unit, relieving the energy system researcher from the costly and demanding real testing that, at least in the first stages of development, can thus be substituted by the simulation model

Group valued null sequences and metrizable non-Mackey groups

For a topological abelian group X we topologize the group c0(X) of all X-valued null sequences in a way such that when X= the topology of c0() coincides with the usual Banach space topology of the classical Banach space c0. If X is a non-trivial compact connected metrizable group, we prove that c0(X) is a non-compact Polish locally quasi-convex group with countable dual group c0(X). Surprisingly, for a compact metrizable X, countability of c0(X) leads to connectedness of X. Our principal application of the above results is to the class of locally quasi-convex Mackey groups (LQC-Mackey groups). A topological group (G,) from a class of topological abelian groups will be called a Mackey group in or a -Mackey group if it has the following property: if is a group topology in G such that (G,) and (G,) has the same character group as (G,), then . Based upon the results obtained for c0(X), we provide a large family of metrizable precompact (hence, locally quasi-convex) connected groups which are not LQC-Mackey. Namely, we show that for a connected compact metrizable group X0, the group c0(X), endowed with the topology induced from the product topology on X, is a metrizable precompact connected group which is not a Mackey group in LQC. Since metrizable locally convex spaces always carry the Mackey topology – a well-known fact from Functional Analysis –, our results prove that a Mackey theory for abelian groups is not a simple traslation of items known to hold for locally convex spaces. This paper is a contribution to the Mackey theory for groups, where properties of a topological nature like compactness or connectedness have an important role