623 resultados para GPA
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Mechanical and tribological properties of AISI 304 and AISI 316 stainless steels submitted to glow discharge ion nitriding are reported. The atmosphere was 20:80 - N2:H2 with substrate temperatures ranging from 300 to 500 °C. Treatment at 300 °C produced expanded austenite (γN) in both steels. Increasing the temperature, the phases γ′-Fe4N and ε- Fe2+xN were present and the latter is the major phase for AISI 304. At 500 °C, the CrN phase was also identified in both steels. Hardnesses of about 13-14 GPa at near surface regions were obtained in both steels. Moreover, AISI 316 nitrided at 500 °C has the deepest hard layer. Tribological tests showed that wear can be reduced by up to a factor of six after the nitriding processes, even for a working temperature of 300 °C. The profiles during and after nanoscratch tests did not reveal significant differences after nitriding processes in both steels.
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La persuasión coercitiva es un subtipo de persuasión, una modalidad de influencia caracterizada por la aplicación de estrategias abusivas. Su aplicación implica una agresión, en ocasiones sumamente sutil, que combina técnicas ambientales, emocionales, cognitivas y disociativas, alterando la capacidad crítica de quien la recibe y generando, habitualmente, importantes daños psicológicos y desajustes sociales. Los grupos coercitivos, entre ellos las sectas destructivas, se caracterizan por aplicar estas técnicas con una elevada reiteración, persistencia e intensidad. Estas técnicas suelen aplicarse de forma planificada y engañosa; su graduación dificulta que las personas que la reciben detecten la agresividad y el perjuicio que conllevan. Resulta necesario definir clara y objetivamente qué acciones, actitudes y estrategias resultan manipulativas y a partir de qué grado o intensidad podría considerarse que un determinado grupo aplica, sistemáticamente, persuasión coercitiva. Si es patente la escasez de instrumentos de medición del abuso psicológico en diferentes ámbitos (violencia en pareja, acoso laboral, acoso escolar, etc.), aún menor ha sido el desarrollo de herramientas que valoren la presencia de estrategias coercitivas o abusivas en contextos grupales. En tanto que la aplicación de estas estrategias puede derivar en graves consecuencias psicosociales, resulta necesario el desarrollo de instrumentos que puedan resultar de utilidad en contextos clínicos y forenses. El objetivo principal de esta tesis es desarrollar y validar nuevas herramientas de evaluación de persuasión coercitiva en contextos grupales, para lo que se llevaron a cabo dos estudios empíricos: 1) Validación de la Entrevista de Evaluación de Persuasión Coercitiva (EPC). Recoge una amplia gama de coerciones y abusos desarrollados en contextos grupales manipulativos, consta de 66 preguntas con dos secciones de evaluación. La principal, con 61 preguntas, recoge 17 técnicas de persuasión coercitiva, dentro de cuatro subtipos de persuasión coercitiva: ambiental, emocional, cognitiva y disociativa (Cuevas y Canto, 2006). Se emplearon dos procedimientos para examinar su validez de contenido, los cuales aportaron resultados positivos. En primer lugar, la proporción de acuerdo (pa = 0,87), que mostró una concordancia muy relevante entre los 191 evaluadores que participaron. El análisis ítem a ítem mostró la conveniencia de no eliminar ninguna de las preguntas. En segundo lugar, la kappa de Fleiss, que suprime el efecto atribuible al azar (k = 0,57; k = 0,61 si se obvia uno de los diez casos clínicos valorados), sugiere un acuerdo entre moderado y bueno. 2) Diseño y validación de la Escala de Detección de Persuasión Coercitiva (EDPC). A partir de la validación de la entrevista anterior se diseñó esta escala, en una versión inicial de 50 ítems. Se analizaron sus propiedades psicométricas, que fueron también satisfactorias. Su fiabilidad, como consistencia interna, fue examinada con el Alfa de Cronbach estandarizado, resultando ser muy alta para su versión de 50 ítems (α =0,93), y aún mejor para la versión final propuesta de 40 ítems (α =0,97). Se analizó la distribución de las puntuaciones, concluyendo la no normalidad de su distribución, así como su estructura interna factorial, concluyendo la presencia de un factor: persuasión coercitiva. En cuanto a su validez, se examinó la validez convergente con la escala de Abuso Psicológico Grupal (GPA, Chambers, Langone, Dole y Grice, 1994), que mide abuso psicológico; las correlaciones fueron muy elevadas y significativas (p<0,01), especialmente con respecto a su escala global (r = 0,77**). También se examinó su validez de criterio o predictiva con distintas herramientas de ajuste psicológico, correlacionando positivamente de forma elevada, o moderadamente, con algunas escalas o subescalas relacionadas con ideación paranoide, eventos vitales estresantes, cogniciones postraumáticas, etc. En definitiva, se valida la entrevista EPC y se diseña y valida una nueva escala, la EDPC. Dos herramientas que se validan en población española, con unas adecuadas propiedades psicométricas, que pueden resultar de gran utilidad en el ámbito clínico y forense, con objeto de valorar el control y la manipulación ejercidas en contextos grupales. Utilizar este tipo de herramienta resulta relevante para poder constatar la responsabilidad de los grupos coercitivos, facilitando relacionar los daños valorados en las víctimas, con las acciones concretas desarrolladas por grupos, o personas, que llevan a cabo comportamientos abusivos. Referencias Bibliográficas: Chambers, W.V., Langone, M.D., Dole, A.A.y Grice, J.W. (1994). The Group Psychological Abuse Scale: A Measure of the Varieties of Cultic Abuse. Cultic Studies Journal, 11, 88-117. Cuevas, J.M. y Canto, J.M. (2006). Sectas: cómo funcionan, cómo son sus líderes, efectos destructivos y cómo combatirlas. Málaga: Aljibe.
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Wydział Chemii
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The purpose of this study is to explore the relationship between various collegiate experiences including substance use, religiosity, campus climate, academic life, social life, self-concept, satisfaction with college, and perceived feelings of depression among Asian American college students compared to other racial groups. Employing Astin’s (1993) I-E-O model, the study utilized the 2008 Cooperative Institutional Research Program (CIRP) the Freshman Survey (TFS) and the follow up College Senior Survey (CSS) in 2012 with the final sample of 10,710 students including 951 Asian American students. Descriptive analysis, cross-tabulations, blocked hierarchical multiple regression analysis, the equality of the unstandardized beta coefficients from the regression analyses, and a one-way ANOVA were conducted for the data analysis. Asian American students who are female, from low SES backgrounds, academically less achieved, frequent substance users, less religiously involved, and less satisfied with overall college experiences showed higher levels of feeling depressed. For the rate of feeling depressed across racial groups, Asian American college students showed the highest rate of feeling depressed while White students reported the lowest rate of feeling depressed. For Asian American college students, feeling depressed in high school, hours spent per week on studying and homework, and self-confidence in intellectual ability were the most significant predictors of feelings of depression while drinking beer, drinking liquor, spirituality, failing to complete homework on time, hours spent per week on socializing, self rated self-confidence in social ability, and satisfaction with overall college experiences were significant predictors of feelings of depression. Asian American college students spent the longest hours on studying and homework, reported the highest GPA, but showed the lowest self-confidence on intellectual ability. For all four racial groups, feeling depressed in high school and self-confidence in intellectual ability were significant predictors of feelings of depression in common. Implications for practice and directions for future research emphasize the need for better understanding the unique cultural background and impact of academic life associated with feelings of depression among Asian American college students and developing customized psycho-educational and outreach programs to meet unique needs for psychological well-being for each racial group on campus.
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The academic achievement of African American adolescents is a national concern for educators and researchers especially since current reports depict the underachievement of African American students as continuing to lag behind their European American peers. Determining what factors within the school environment that contributes to the achievement gap and how it can be reduced remains an important issue in alleviating disparities seen in educational achievement and attainment. This study examined the relation between characteristics of the close friendships of high-achieving African American adolescents and students’ identity development and motivation in school. Data were collected from 217 high-achieving African American students within 10th to 12th grade from 5 public and private high schools. Each student self-reported on their ethnicity, gender, parents’ education level, grade, FARMs, GPA, perceived teacher support (emotional, academic, and instrumental support), their perception of their ethnic identity, and their perception of their achievement values. Through the use of nomination procedures, students also identified their close friends and responded to questions concerning how supportive (emotional, academic, and instrumental support) they each were. Results from multiple regression analyses showed that the provision of instrumental support from close friends related to the exploration process of the high-achieving students’ ethnic identity. In addition, there was a strong relation between the ethnic identity of close friends and that of the individual. Furthermore, although friend support was not a significant predictor of achievement values, demographic (mother’s education level, grade, and FARMS) and control (teacher support) variables predicted students’ importance and utility of school respectively. These findings add to the literature on age and socioeconomic status as they relate to student’s motivation to achieve. Overall, this study provides some evidence highlighting ways in which close friendships might relate to the self-development of high-achieving African American adolescents. This study provides a starting point for additional ways in which to explore how peer processes relate to the academic behaviors of high-achieving African American adolescents.
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In this study, relations among students’ perceptions of instrumental help/support from their teachers and their reading and math ability beliefs, subjective task values, and academic grades, were explored from elementary through high school. These relations were examined in an overall sample of 1,062 students from the Childhood and Beyond (CAB) study dataset, a cohort-sequential study that followed students from elementary to high school and beyond. Multi-group structural equation model (SEM) analyses were used to explore these relations in adjacent grade pairs (e.g., second grade to third grade) in elementary school and from middle school through high school separately for males and females. In addition, multi-group latent growth curve (LGC) analyses were used to explore the associations among change in the variables of interest from middle school through high school separately for males and females. The results showed that students’ perceptions of instrumental help from teachers significantly positively predicted: (a) students’ math ability beliefs and reading and math task values in elementary school within the same grade for both girls and boys, and (b) students’ reading and math ability beliefs, reading and math task values, and GPA in middle and high school within the same grade for both girls and boys. Overall, students’ perceptions of instrumental help from teachers more consistently predicted ability beliefs and task values in the academic domain of math than in the academic domain of reading. Although there were some statistically significant differences in the models for girls and boys, the direction and strength of the relations in the models were generally similar for both girls and boys. The implications for these findings and suggestions for future research are discussed.
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Black boys are confronted with unique educational circumstances. They are often misdiagnosed and misplaced into special education programs (Bush-Daniels, 2008; Patton, 1998; Terman et al., 1996). Additionally, they are less likely to be enrolled in gifted and talented programs, even if their former achievements reflect their aptitude to succeed (Black Alliance for Educational Options, n.d.; Moore & Flowers, 2012). Given these statistics, a considerable emphasis has been placed on the causes and the consequences of low/under achievement for this population. As a result, the experiences of Black males who are achieving have been greatly neglected. Moreover, little is known about the factors that facilitate academic achievement among high-achieving Black boys. In an effort to bring the heterogenic nature of schooling experiences for Black boys to light, the present study examined the influence risk and protective factors had on the academic experiences of high-achieving Black boys. Grounded in the risk and resilience framework and the Integrative Model for the Study of Minority Youth Development, this study explored whether the high-achieving Black high school boys in this sample (n =88) reported experiencing discrimination (i.e. academic-based) and how this academic-based discrimination related to their 1) academic performance (i.e. GPA), 2) perceptions of math ability, and 3) race-based academic self-concept. In addition to exploring how academic-based discrimination was linked to academic achievement, this study examined how cultural resources such as racial socialization messages and racial identity related to academic achievement. Specifically, cultural socialization, preparation for bias, egalitarianism, private regard and public regard were evaluated alongside the three academic outcomes under study. Finally, the study explored whether aspects of racial socialization or racial identity buffered the effects of discrimination on any of the outcomes. Interestingly, the race/ethnicity of the student mattered for how students perceived their math ability. The risk factor academic-based discrimination was linked to academic performance. Cultural resources cultural socialization, preparation for bias, and private regard were linked to various academic outcomes of interest. There was only one significant moderating effect: a high private regard buffered the relationship between academic-based discrimination and race-based academic self-concept. Limitations and implications of this study are discussed.
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Research on the transition to adulthood dates back nearly four decades, but a growing body of research has taken a new approach by investigating multiple demographic markers in the transition to adulthood simultaneously. Using the life course perspective, this dissertation is built on the literature by first examining contemporary young adults’ pathways to adulthood from ages 18 to 30 and their differences by gender. Data for this study were drawn from the National Longitudinal Survey of Youth 1997; the final sample included 2,185 men and 2,086 women. The college-educated single workers pathway, the college-educated married working parents pathway, and the high-school-educated single parents pathway were identified in both genders. For men, the study also identified the high-school-educated single workers pathway and the high-school-educated married working parents pathway. For women, the study also identified the high-school-educated workers pathway and the high-school-educated married parents pathway. Not only did the definitions of some pathways differ by gender, but even in the pathways with the same definition, gender differences were found in the probabilities of being married, of being a parent, or of being employed full-time. Based on the pathways to adulthood identified, this research examined the family and adolescent precursors and whether race moderates the associations between family structure experiences and young adults’ pathways to adulthood. Parental education, family structure, GPA, delinquency, early sexual activity, and race/ethnicity were the family and adolescent precursors that distinguished among pathways taken by the youth. Two interactions between race and family structure/instability were identified. The positive association between growing up in a single-parent family and the odds of taking the high-school-educated single workers pathway compared to the college-educated married working parents pathway was weaker for Black males than for White males. The positive association between family instability and the odds of taking the college-educated single workers pathway compared to the college-educated married working parents pathway was weaker for Black females than for White females. This dissertation accounted for changes in the multiple statuses related to becoming an adult by following contemporary young adults for 12 years. More research on contemporary young adults’ pathways to adulthood and subgroup differences in the effects of precursors are recommended. Limitations and implications of this study are discussed.
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Oil wells subjected to cyclic steam injection present important challenges for the development of well cementing systems, mainly due to tensile stresses caused by thermal gradients during its useful life. Cement sheath failures in wells using conventional high compressive strength systems lead to the use of cement systems that are more flexible and/or ductile, with emphasis on Portland cement systems with latex addition. Recent research efforts have presented geopolymeric systems as alternatives. These cementing systems are based on alkaline activation of amorphous aluminosilicates such as metakaolin or fly ash and display advantageous properties such as high compressive strength, fast setting and thermal stability. Basic geopolymeric formulations can be found in the literature, which meet basic oil industry specifications such as rheology, compressive strength and thickening time. In this work, new geopolymeric formulations were developed, based on metakaolin, potassium silicate, potassium hydroxide, silica fume and mineral fiber, using the state of the art in chemical composition, mixture modeling and additivation to optimize the most relevant properties for oil well cementing. Starting from molar ratios considered ideal in the literature (SiO2/Al2O3 = 3.8 e K2O/Al2O3 = 1.0), a study of dry mixtures was performed,based on the compressive packing model, resulting in an optimal volume of 6% for the added solid material. This material (silica fume and mineral fiber) works both as an additional silica source (in the case of silica fume) and as mechanical reinforcement, especially in the case of mineral fiber, which incremented the tensile strength. The first triaxial mechanical study of this class of materials was performed. For comparison, a mechanical study of conventional latex-based cementing systems was also carried out. Regardless of differences in the failure mode (brittle for geopolymers, ductile for latex-based systems), the superior uniaxial compressive strength (37 MPa for the geopolymeric slurry P5 versus 18 MPa for the conventional slurry P2), similar triaxial behavior (friction angle 21° for P5 and P2) and lower stifness (in the elastic region 5.1 GPa for P5 versus 6.8 GPa for P2) of the geopolymeric systems allowed them to withstand a similar amount of mechanical energy (155 kJ/m3 for P5 versus 208 kJ/m3 for P2), noting that geopolymers work in the elastic regime, without the microcracking present in the case of latex-based systems. Therefore, the geopolymers studied on this work must be designed for application in the elastic region to avoid brittle failure. Finally, the tensile strength of geopolymers is originally poor (1.3 MPa for the geopolymeric slurry P3) due to its brittle structure. However, after additivation with mineral fiber, the tensile strength became equivalent to that of latex-based systems (2.3 MPa for P5 and 2.1 MPa for P2). The technical viability of conventional and proposed formulations was evaluated for the whole well life, including stresses due to cyclic steam injection. This analysis was performed using finite element-based simulation software. It was verified that conventional slurries are viable up to 204ºF (400ºC) and geopolymeric slurries are viable above 500ºF (260ºC)
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This Document is Protected by copyright and was first published by Frontiers. All rights reserved. It is reproduced with permission.
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El Salvador, se encuentra bajo un contexto en donde el Libre Comercio y la Integración Económica despuntan como las principales estrategias de un modelo capitalista aplicado por los diferentes países de la región, se vuelve oportuno facilitar espacios y condiciones que propicien un camino con la dirección correcta hacia la competitividad empresarial, especialmente para la Pequeña Empresa, debido a que este sector juega un papel importante en la economía nacional. En este sentido, es necesario estimular el fortalecimiento de cada una de estas unidades empresariales a través de la aplicación de mecanismos de cooperación inter empresas, es decir, Asociatividad, término empleado recientemente en nuestro país; mas sin embargo, de mucha utilidad para contrarrestar los efectos negativos de la apertura de nuevos mercados y aprovechar las oportunidades que ofrece esta modalidad. Es así, como el Gobierno de El Salvador ha designado a la Comisión Nacional para la Micro y Pequeña Empresa (CONAMYPE), el fomento de la Asociatividad como estrategia para incrementar la competitividad dentro de la Pequeña Empresa. Para ello, luego de la convocatoria y selección de diversas entidades gubernamentales y no gubernamentales claves en desarrollo del sector, se constituye el Grupo Promotor (GPA), organización destinada a promover y unificar la transferencia de modelos asociativos y crear las condiciones de acceso al mercado a nivel nacional. No obstante, a pesar de la existencia de este organismo, no se han observado resultados óptimos en la consecución de su principal objetivo y el protagonismo del GPA ha caído debido a sus precarios logros y a que no cuenta con un Plan Estratégico que oriente sus acciones y determine el nivel de efectividad de los esfuerzos empleados por estas entidades. Debido a la situación actual que enfrenta nuestra economía nacional, se reitera con esta investigación la disposición de aunar esfuerzos en beneficio de los sectores más vulnerables, con la propuesta de un Plan Estratégico que fortalezca el accionar del GPA como ente líder nacional y regional en el proceso de asociatividad de la Pequeña Empresa. Siguiendo el método de investigación científico de carácter deductivo, se estructuro el documento a continuación en tres apartados o capítulos, el primero que conduce al marco teórico en donde se fundamentan los conocimientos y terminología utilizada; seguidamente el Capítulo II presenta mediante el Diagnóstico, la situación actual de la Pequeña Empresa, del Proceso de Asociatividad y del Grupo Promotor (GPA); finalmente en el Capítulo III se presenta la Propuesta del Plan Estratégico para un período de cinco años en los cuales se le determina al GPA elementos como: Misión y Visión, que replantea el actuar del Grupo Promotor, al enfocarse en si mismo sobre lo que espera alcanzar, además se incorporan Objetivos, para brindarle de una mayor claridad a cada uno de los miembros sobre los Retos Esperados, de igual forma se establecen Estrategias las cuales se implementarán para superar esos retos en el menor tiempo posible, así mismo se identifican Líneas de Acción, Presupuestos entre otros, todos ellos orientados bajo la modalidad de cinco fuerzas competitivas, con los cuales deberá el Grupo transformarse en un ente Eficaz habiendo logrado incrementar la Asociatividad en la Pequeña Empresa Salvadoreña.
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Using unexplored Japanese and Swiss public procurement data over 1990-2003, we examine the effect of macroeconomic, political economy, procurement-specific and domestic policy factors on governments’ sourcing decisions. We also provide for an empirical test of Baldwin's (1970, 1984) "neutrality proposition" and for the effectiveness of the WTO's Uruguay Round Agreement on Government Procurement (URGPA) in increasing foreign market access. Our results suggest the importance of the magnitude of procurement demand, domestic firm attributes and unobserved sector-specific heterogeneity in these governments' purchases from abroad. However, the expected impact of traditional macroeconomic variables and political budget cycles does not come through in our results. Public and private sector imports do not offset each other in our analyses for Japan and only selectively for Switzerland. Finally, membership of the GPA is only found to increase the value of foreign procurement in Switzerland, though it seems to increase the import demand for contracts in both countries.
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This paper studies the government procurement of services from foreign suppliers by conducting a statistical analysis of data submitted by Japan and Switzerland to the WTO's Committee on Government Procurement. Using several metrics, the paper examines if the WTO’s Agreement on Government Procurement (GPA) has led to greater market access for foreign suppliers in services procurement. Our results indicate that despite the GPA, the proportions of services contracts awarded to foreigners have declined over time for both countries and in the absence of this decline, the value of services contracts awarded to foreign firms would have been more than 15 times higher in the case of Japan and nearly 68 times more in the case of Switzerland. We also find that for the same services categories, at least the Japanese government is not purchasing as much from abroad as it's private sector is importing from the rest of the world, a finding that further points to the home-bias in that government's public purchase decisions.
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Paper presented by Charlotte Sieber-Gasser at the African IEL Network Conference, 5th-6th of May 2011, The Mandela Institute, Johannesburg (South Africa) Sino-African trade has seen a fifty-fold increase in the years 1999 to 2008. China became the second most important trading partner for the African economy and already overtook the US as the most important trading partner in some African regions. However, all of this trade is taking place independent from legal regulation by a preferential or other trade agreement. Interestingly, Sino-African trade has seen particular increase in countries that have agreed to tied aid arrangements with China. Taking a closer look at these tied aid arrangements (the so-called Angola-Model) reveals, that some aspects might indeed have a positive effect on Sino-African trade in general. Several grey areas might potentially conflict with WTO-law. However, tied aid is excluded from the GATS, the GATT, and the GPA – in other words, it is outside the sphere of WTO-law. The paper analyses three critical aspects of the Angola-Model version of tied aid with reference to WTO-law, and elaborates the importance of regulating trade-distorting aspects of modern tied aid.
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Doped lanthanum chromite ( LaCrO3 ) has been the most common material used as interconnect in solid oxide fuel cells for high temperature ( SOFC-HT ) that enabling the stack of SOFCs. The reduction of the operating temperature, to around 800 º C, of solid oxide fuel cells enabled the use of metallic interconnects as an alternative to ceramic LaCrO3, From the practical point of view, to be a strong candidate for interconnect the material must have good physical and mechanical properties such as resistance to oxidizing and reducing environments, easy manufacture and appropriate thermo-mechanical properties. Thus, a study on the physic-mechanical interconnects La0,8Sr0,2Cr0,92Co0,08O3 ceramics for SOFC -AT obtained by the method of combustion , as well as thermo-mechanical properties of metallic interconnects (AISI 444) covered with La0,8Ca0,2CrO3 by deposition technique by spray-pyrolysis fuel cells for intermediate temperature (IT-SOFCs). The La0,8Sr0,2Cr0,92Co0,08O3 was characterized by X -ray diffraction(XRD) , density and porosity , Vickers hardness (HV) , the flexural strength at room temperature and 900 °C and scanning electron microscopy (SEM). The X -ray diffraction confirmed the phase formation and LaCrO3 and CoCr2O4, in order 6 GPa hardness and mechanical strength at room temperature was 62 MPa ceramic Interconnector. The coated metal interconnects La0,8Ca0,2CrO3 passed the identification by XRD after deposition of the film after the oxidation test. The oxidative behavior showed increased resistance to oxidation of the metal substrate covered by La0,8Ca0,2CrO3 In flexural strength of the coated metal substrate, it was noticed only in the increased room temperature. The a SEM analysis proved the formation of Cr2O3 and (Cr,Mn)3O4 layers on metal substrate and confirmed the stability of the ceramic La0,8 Ca0,2CrO3 film after oxidative test