bluuebunny/crossref_metadata_2025 huggingface dataset:
Analog and Logic High Temperature Integrated Circuits Based on Enhancement Mode Planar SiC JFETs
Authors: Alexandrov Peter , O'Grady Matt , Merrett Neil , Walter Laura
Published: May 2018

This paper presents initial results on developing high temperature capable SiC JFET based IC technology. All JFET devices are fully planar, formed by ion implantation, and the device design allows the use of semi-insulating or conductive substrates. Basic analog and logic ICs were built in order to demonstrate the technology high temperature capability. All circuits used enhancement mode n-channel JFETs as active transistors, and depletion mode transistors as active loads. The logic circuits built included NOT, NAND, and NOR gates. The analog circuits built included a simple one-stage operational amplifier. JFETs and ICs were packaged in ceramic DIP packages and tested at temperatures up to 350°C, which was the IC design target maximum operating temperature.
High heat-density SiC heater chip for thermal characterization of high temperature packaging
Authors: Wakasugi Naoki , Nagao Shijo , Dongjin Kim , Suganuma Katsuaki
Published: May 2018

In the present study, we introduce a heater dummy chip equipped with temperature sensor, with extremely high capability of high heat-density using SiC wafer. As often used in high voltage/temperature SiC devices exhibit their advantage of high thermal stability and heat conductivity. Our testing heater chip (thermal test engineering group, TEG) consist of insulated SiC and Pt thin-film heater and temperature sensor realizes extreme heat density of 250 W/mm2 with reliability above 300°C of high temperature. The TEG chip was the n-doped 4H SiC chip, which is used generally for SiC devices, coated with an alumina insulation film and molded the Pt heater and sensor by lithography technique. Using the TEG chip, we demonstrate simple but accurate heat resistant measurements of several types of metal bonded ceramic substrates. The combination of SiC TEG chip and heat resistance measurement system is also applied to power cycle testing, avoiding numerous problems arising from using actual working device chips. Therefore, this study systematically was carried out the thermal measurement technology of SiC with repetitive power cycle by TEG chip as new concept heat system. Through this progress, the technologies developed in the study may have further applications in evaluation and testing of various packaging materials targeted for high temperature/wattage power modules.
A 300°C High Reliability HALT/HAST Screening/Sorting Procedure for Ceramic Capacitors
Authors: Snyder Harold L.
Published: May 2018

A highly accelerated life test (HALT) and highly accelerated stress test (HAST) procedure for ceramic capacitors developed by the author in the mid 1980's to early 1990's, and published in 1994, consists of a 400 Volt biased six (6) hour stress sort at 150°C (423K), a methanol current leakage test that located mechanical and structural cracks, a visual inspection at ten times (10×) magnification, and a capacitance and dissipation measurement before and after the test. In over thirty (30) years of use, there has never been a user reported in-circuit failure in industrial, military, and aerospace application at temperatures as high as 500°C (773K). However, reviewing user feedback, two concerns with the original sorting procedure are the stress is performed at 150°C (423K), and the lack of a more detailed ceramic capacitor electrical model. To address the first, the low aging temperature, the stress temperature was increased from 150°C to 300°C, in order to age ceramic solid state crystal mineral phases that may change with temperature. The test results for X7R and NP0/COG multilayer ceramic capacitors (MLCC) at 300°C, are compared to the test results using the original HALT/HAST procedure at 150°C. Differences between X7R/NP0/COG and porcelain capacitors are discussed when applicable. Further, a more detailed ceramic capacitor electrical model that represents the physical and electrical characteristics of the ceramic capacitors is presented, including the electrical current leakage effects with temperature, and the carbonized residue effects from the manufacturing process.
The socio-economic effects of mechanising and/or modernising hard rock mines in South Africa
Authors: Gumede Hlangabeza
Published: May 2018

Background and aim: This article aims to explore stakeholders’ views on the potential effects of modernising hard rock mines in South Africa. Methods: This objective was achieved through eliciting and bringing together the views of different stakeholders. Different stakeholders were interviewed using qualitative research methodologies. The sample demographics were fairly representative and ranged from operators to executives and from employee to employer representatives. The main form of data collection was one-on-one face-to-face interviews. Results: One of the major findings of this research is that stakeholders have different levels of understanding of mechanisation and modernisation. The levels of understanding were found to be proportional to the levels of education. Conclusion: There seems to be general support for mechanisation and modernisation among the participants. The identified socio-economic challenges and benefits were relatively similar and aligned among participants. The main difference, however, pertained to the depth and scope of the problem or opportunity as perceived by different participants. Interviewees were also unanimous in identifying the social-economic benefits of mechanisation; these were in line with those identified in the literature, namely benefits in occupational health and safety issues, efficiency, costs and improved life of mines. Furthermore, participants viewed mechanisation and modernisation as an opportunity to reskill themselves and to improve operations and quality of life. More importantly, stakeholders seemed to share a common vision and interest of the future; as such, they were able to see beyond their constituencies and interests.
Editorial
Authors: Merino Cristian
Published: May 2018

Editorial de presentación del primer número
La Historia de la Ciencia como elemento catalizador de la enseñanza de la Biología y la Naturaleza de la Ciencia
Authors: Nuñez Paola , Pavez José , Santibañez David , Becerra Beatriz , Cofré Hernán
Published: May 2018

Pese a que educadores en ciencia reconocen a la historia de la ciencia (HOS) como un elemento importante para la enseñanza de la ciencia y de la naturaleza de la ciencia (NOS), los profesores no parecen reconocer el valor que posee la HOS, ni disponen de materiales para incorporarla en sus aulas.  En este trabajo se revisa el papel que juega la HOS en la enseñanza de la ciencia, como un elemento motivador para la enseñanza de contenidos conceptuales, para fomentar el espíritu crítico, para invitar a los estudiantes a hacerse preguntas, para identificar sus obstáculos conceptuales y para la enseñanza de NOS. Se analizarán los distintos elementos históricos que se han propuesto para incluir en las estrategias didácticas, donde destacan los errores científicos, experimentos clásicos, disputas, desarrollo de teorías, entre otros. En cuanto a los enfoques de enseñanza para incorporar la HOS en la clase de ciencia, se revisan tanto modelos implícitos (Monk y Osborne, 1997), como explícitos (Paraskevopoulou & Koliopoulos, 2010, Rudge y Howe (2009). Para ejemplificar tanto elementos históricos usados como modelos de enseñanza de la HOS, se expone una propuesta para la enseñanza de la genética, considerando el desarrollo histórico de la teoría de la herencia para enseñar algunos conceptos científicos y algunos aspectos de NOS. Luego de realizar una revisión de los programas de estudio vigentes en Chile se evidencia la mención recurrente de elementos de la HOS, pero sin mayores propuestas didácticas para su incorporación en las clases. Finalmente se discuten las implicancias y desafíos del uso de HOS para la enseñanza de las ciencias y la formación inicial y continua.
Decrease in tropospheric O3 levels in the Northern Hemisphere observed by IASI
Authors: Wespes Catherine , Hurtmans Daniel , Clerbaux Cathy , Boynard Anne , Coheur Pierre-François
Published: May 2018

Abstract. In this study, we describe the recent changes in
the tropospheric ozone (O3) columns measured by the Infrared Atmospheric
Sounding Interferometer (IASI), onboard the Metop satellite, during the first 9
years of operation (January 2008 to May 2017). Using appropriate
multivariate regression methods, we differentiate significant linear trends
from other sources of O3 variations captured by IASI. The geographical
patterns of the adjusted O3 trends are provided and discussed on the
global scale. Given the large contribution of the natural variability in
comparison with that of the trend (25–85 % vs. 15–50 %,
respectively) to the total O3 variations, we estimate that additional
years of IASI measurements are generally required to detect the estimated
O3 trends with high precision. Globally, additional 6 months to
6 years of measurements, depending on the regions and the seasons, are needed
to detect a trend of |5| DU decade−1. An exception is interestingly
found during summer at mid- and high latitudes of the Northern Hemisphere (NH;
∼ 40 to ∼ 75∘ N), where the large absolute fitted trend values
(∼ |0.5| DU yr−1 on average) combined with the small model
residuals (∼ 10 %) allow for detection of a band-like pattern of
significant negative trends. Despite no consensus in terms of
tropospheric O3 trends having been reached from the available
independent datasets (UV or IR satellites, O3 sondes, aircrafts,
ground-based measurements, etc.) for the reasons that are discussed in the
text, this finding is consistent with the reported decrease in O3
precursor emissions in recent years, especially in Europe and USA. The
influence of continental pollution on that latitudinal band is further
investigated and supported by the analysis of the O3–CO relationship
(in terms of correlation coefficient, regression slope and covariance) that
we found to be the strongest at northern midlatitudes in summer.
Characterisation of the melting layer variability in an Alpine valley based on polarimetric X-band radar scans
Authors: van den Heuvel Floor , Gabella Marco , Germann Urs , Berne Alexis
Published: May 2018

Abstract. The melting layer designates the transition region from solid to liquid precipitation, and is a typical feature of the vertical structure of stratiform precipitation. As it is characterised by a well-known signature in polarimetric radar variables, it can be identified by automatic detection algorithms. Though often assumed to be uniform in space and time for applications such as vertical profile correction, the spatial variability of the melting layer remains poorly documented. This work undertakes to characterise and quantify the spatial and temporal variability of the melting layer using a method based on the Fourier transform, which is applied to high resolution X-band polarimetric radar data from two measurement campaigns in Switzerland. It is first demonstrated that the proposed method can accurately and concisely describe the spatial variability of the melting layer and may therefore be used as a tool for comparison. The method is then used to characterise the melting layer variability in summer precipitation on the relatively flat Swiss plateau and in winter precipitation in a large inner Alpine valley (the Rhone valley in the Swiss Alps). Results indicate a higher contribution of smaller spatial scales to the total melting layer variability in the case of the Alpine environment. The same method is also applied on data from vertical scans in order to study the temporal variability of the melting layer. The variability in space and time is then compared to investigate the spatio-temporal coherence of the melting layer variability in the two study areas, which was found to be more consistent with the assumption of pure advection for the case of the plateau.
Random and externally controlled occurrences of Dansgaard–Oeschger events
Authors: Lohmann Johannes , Ditlevsen Peter D.
Published: May 2018

Abstract. Dansgaard–Oeschger (DO) events constitute the most pronounced mode of centennial to millennial climate variability of the last glacial period. Since their discovery, many decades of research have been devoted to understand the origin and nature of these rapid climate shifts. In recent years, a number of studies have appeared that report emergence of DO-type variability in fully coupled general circulation models via different mechanisms. These mechanisms result in the occurrence of DO events at varying degrees of regularity, ranging from periodic to random. When examining the full sequence of DO events as captured in the North Greenland Ice Core Project (NGRIP) ice core record, one can observe high irregularity in the timing of individual events at any stage within the last glacial period. In addition to the prevailing irregularity, certain properties of the DO event sequence, such as the average event frequency or the relative distribution of cold versus warm periods, appear to be changing throughout the glacial. By using statistical hypothesis tests on simple event models, we investigate whether the observed event sequence may have been generated by stationary random processes or rather was strongly modulated by external factors. We find that the sequence of DO warming events is consistent with a stationary random process, whereas dividing the event sequence into warming and cooling events leads to inconsistency with two independent event processes. As we include external forcing, we find a particularly good fit to the observed DO sequence in a model where the average residence time in warm periods are controlled by global ice volume and cold periods by boreal summer insolation.
Influence of atmospheric internal variability on the long-term Siberian water cycle during the past 2 centuries
Authors: Oshima Kazuhiro , Ogata Koto , Park Hotaek , Tachibana Yoshihiro
Published: May 2018

Abstract. River discharges from Siberia are a large source of freshwater into the
Arctic Ocean, whereas the cause of the long-term variation in Siberian
discharges is still unclear. The observed river discharges of the Lena in the
east and the Ob in the west indicated different relationships in each of the
epochs during the past 7 decades. The correlations between the two river
discharges were negative during the 1980s to mid-1990s, positive during the
mid-1950s to 1960s, and became weak after the mid-1990s. More long-term
records of tree-ring-reconstructed discharges have also shown differences in
the correlations in each of the epochs. It is noteworthy that the
correlations obtained from the reconstructions tend to be negative during the
past 2 centuries. Such tendency has also been obtained from precipitations
in observations, and in simulations with an atmospheric general circulation
model (AGCM) and fully coupled atmosphere–ocean GCMs conducted for the
Fourth Assessment Report of the IPCC. The AGCM control simulation further
demonstrated that an east–west seesaw pattern of summertime large-scale
atmospheric circulation frequently emerges over Siberia as an atmospheric
internal variability. This results in an opposite anomaly of precipitation
over the Lena and Ob and the negative correlation. Consequently, the
summertime atmospheric internal variability in the east–west seesaw pattern over
Siberia is a key factor influencing the long-term variation in precipitation
and river discharge, i.e., the water cycle in this region.
Hydro-stochastic interpolation coupling with the Budyko approach for prediction of mean annual runoff
Authors: Qiu Ning , Chen Xi , Hu Qi , Liu Jintao , Huang Richao , Gao Man
Published: May 2018

Abstract. The hydro-stochastic interpolation method based on traditional block Kriging
has often been used to predict mean annual runoff in river basins. A caveat
in such a method is that the statistic technique provides little physical
insight into relationships between the runoff and its external forcing, such
as the climate and land cover. In this study, the spatial runoff is
decomposed into a deterministic trend and deviations from it caused by
stochastic fluctuations. The former is described by the Budyko method (Fu's
equation) and the latter by stochastic interpolation. This coupled method is
applied to spatially interpolate runoff in the Huaihe River basin of China.
Results show that the coupled method significantly improves the prediction
accuracy of the mean annual runoff. The error of the predicted runoff by the
coupled method is much smaller than that from the Budyko method and the
hydro-stochastic interpolation method alone. The determination coefficient
for cross-validation, Rcv2, from the coupled method is 0.87,
larger than 0.81 from the Budyko method and 0.71 from the hydro-stochastic
interpolation. Further comparisons indicate that the coupled method has also
reduced the error in overestimating low runoff and underestimating high
runoff suffered by the other two methods. These results confirm that the
coupled method offers an effective and more accurate way to predict the mean
annual runoff in river basins.
Mapping of the dilemma of mining against forest and conservation in the Lom and Djérem Division, Cameroon
Authors: Tchindjang Mesmin , Voundi Eric , Mbevo Fendoung Philippes , Haman Unusa , Saha Frédéric , Njombissie Petcheu Igor Casimir
Published: May 2018

Abstract. Mining practices in Cameroon began since the colonial period. The artisanal mining sector before independence contributed to 11–20 % of GDP. From 2000, the rich potential of the Cameroonian subsoil attract many foreign investors with over 600 research and mining permits already granted during the last decade. But, Cameroonian forests also have a long history from the colonial period to the pre-sent. However, mining activities in forest environments are governed by two different legal frameworks, including mining code i.e. Law No. 001 of 16 April 2001 organizing the mining industry and Law No. 94-01 of 20 January 1994 governing forests, wildlife and fisheries. Therefore, in the absence of detailed studies of these laws, there are conflicts of interests, rights and obligations that overlap, requiring research needs and taking appropriate decisions. The objective of this research in the Lom and Djérem division is to study, apart from the proliferation of mining li-censes and actors, the dilemma as well as the impact of the extension of mining activities on the degradation of forest cover. Using geospatial tools through multi-temporal and multisensor satellite images (Landsat from 1976 to 2015, IKONOS, GEOEYE, Google Earth) coupled with field investigations; we mapped the dynamic of different forms of land use (mining permits, FMU and protected areas of permanent forest estate) and highlighted paradoxically the conflict of land use. We came to the conclusion that the rhythm of issuing mining permits and authorizations in this forestall zone is so fast that one can wonder whether we still find a patch of forest within 50 years.
Cartography teaching and the development of spatial thinking in Brazilian geography textbooks
Authors: Duarte Ronaldo G.
Published: May 2018

Abstract. Spatial thinking has been recognized as closely related to tools of representation (NRC, 2006) and the maps have been widely pointed out as crucial for the development of that kind of reasoning. Furthermore, the scientific com-munity dedicated to the field of the spatial thinking has been asserting that the abilities encompassed in such a complex cognition can and must be fostered in school. Considering these groundwork, our research focused on the decision to assess the effectiveness of the contribution for the development of student’s spatial thinking, provided by the questions found in Brazilian middle school geography textbooks. The main concern was the proficiency regarding cartographic language. To assure the possibility of comparing our results with some other investigations we decided to use a methodology that was strongly based on the Taxonomy of Spatial Thinking, designed by Injeong Jo and Sarah Bednarz (2009). Counting on those powerful tools we analyzed 6.884 questions in the three most adopted geography textbooks sets in Brazilian middle schools (6th, 7th, 8th and 9th grades). For the purpose of enlarging the number of books and countries to be compared, we have also evaluated 2.073 questions that are present in a French geography textbook set edited for the same grades. Using the taxonomy enabled us not only to evaluate if the questions demanded or not the use of the spatial thinking by the students. It also showed us the three general levels of reasoning involved, allowing to discern between low, intermediate and high levels of spatial thinking.
Using Cesium for 3D Thematic Visualisations on the Web
Authors: Gede Mátyás
Published: May 2018

Abstract. Cesium (http://cesiumjs.org) is an open source, WebGL-based JavaScript library for virtual globes and 3D maps. It is an excellent tool for 3D thematic visualisations, but to use its full functionality it has to be feed with its own file format, CZML. Unfortunately, this format is not yet supported by any major GIS software. This paper intro- duces a plugin for QGIS, developed by the author, which facilitates the creation of CZML file for various types of visualisations. The usability of Cesium is also examined in various hardware/software environments.
New Map Symbol System for Disaster Management
Authors: Marinova Silvia T.
Published: May 2018

Abstract. In the last 10 years Bulgaria was frequently affected by natural and man-made disasters that caused considerable losses. According to the Bulgarian Disaster Management Act (2006) disaster management should be planned at local, regional and national level. Disaster protection is based on plans that include maps such as hazard maps, maps for protection, maps for evacuation planning, etc. Decision-making and cooperation between two or more neighboring municipalities or regions in crisis situation are still rendered difficult because the maps included in the plans differ in scale, colors, map symbols and cartographic design. To improve decision-making process in case of emergency and to reduce the number of human loss and property damages disaster management plans at local and regional level should be supported by detailed thematic maps created in accordance with uniform contents, map symbol system and design. The paper proposes a new symbol system for disaster management that includes a four level hierarchical classification of objects and phenomena according to their type and origin. All objects and phenomena of this classification are divided into five categories: disasters; infrastructure; protection services and infrastructure for protection; affected people and affected infrastructure; operational sites and activities. The symbols of these categories are shown with different background colors and shapes so that they are identifiable. All the symbols have simple but associative design. The new symbol system is used in the design of a series of maps for disaster management at local and regional level.
Synergy between Sentinel-1 radar time series and Sentinel-2 optical for the mapping of restored areas in Danube delta
Authors: Niculescu Simona , Lardeux Cédric , Hanganu Jenica
Published: May 2018

Abstract. Wetlands are important and valuable ecosystems, yet, since 1900, more than 50 % of wetlands have been lost worldwide. An example of altered and partially restored coastal wetlands is the Danube Delta in Romania. Over time, human intervention has manifested itself in more than a quarter of the entire Danube surface. This intervention was brutal and has rendered ecosystem restoration very difficult. Studies for the rehabilitation / re-vegetation were started immediately after the Danube Delta was declared as a Biosphere Reservation in 1990. Remote sensing offers accurate methods for detecting and mapping change in restored wetlands. Vegetation change detection is a powerful indicator of restoration success. The restoration projects use vegetative cover as an important indicator of restoration success. To follow the evolution of the vegetation cover of the restored areas, satellite images radar and optical of last generation have been used, such as Sentinel-1 and Sentinel-2. Indeed the sensor sensitivity to the landscape depends on the wavelength what- ever radar or optical data and their polarization for radar data. Combining this kind of data is particularly relevant for the classification of wetland vegetation, which are associated with the density and size of the vegetation. In addition, the high temporal acquisition frequency of Sentinel-1 which are not sensitive to cloud cover al- low to use temporal signature of the different land cover. Thus we analyse the polarimetric and temporal signature of Sentinel-1 data in order to better understand the signature of the different study classes. In a second phase, we performed classifications based on the Random Forest supervised classification algorithm involving the entire Sentinel-1 time series, then starting from a Sentinel-2 collection and finally involving combinations of Sentinel-1 and -2 data.
Sensor information as a service – component of networked production
Authors: Schmitt Robert H. , Voigtmann Christoph
Published: May 2018

Abstract. Metrology has a key position in networked, adaptive production, with the task of a holistic and valid assessment of the state of various production scenarios. With the diminishing focus on a device-specific development towards an adaptive production network, which is less hierarchical in the sense of the “Internet of production”, and with the focus on the properties of cyber-physical systems (CPSs), new opportunities for the strengthening of metrology arise. Characteristic of these CPSs are sensors for multi-modal data acquisition, actuators for interaction with the environment, distributed computing power and the ability to spontaneously or permanently network itself. They form the basis for the creation of a “digital shadow” and thus are essential components of a model for process control. Current trends and challenges for metrology in networked production, such as multi-sensor systems, model-based measurements, virtual measurement processes or the integration into adaptable production systems, broaden the boundaries of future requirements of metrology, in particular with regard to its flexibility, speed and compatibility. A prerequisite is a scalable, specifiable information fusion. A solution to this is the service-based provision of sensor information, measurement data and decisions, which can be flexibly adapted to task-specific requirements. For this concept of “sensor information as a service”, development stages and prerequisites for its implementation as well as affected areas are discussed.
Microbial community responses determine how soil-atmosphere exchange of carbonyl sulfide, carbon monoxide and nitric oxide respond to soil moisture
Authors: Behrendt Thomas , Catão Elisa C. P. , Bunk Rüdiger , Yi Zhigang , Schwer Elena , Kesselmeier Jürgen , Trumbore Susan
Published: May 2018

Abstract. Carbonyl sulfide (OCS) plays an important role in the global sulfur cycle and is relevant for climate change due to its role as a greenhouse gas, in aerosol formation and atmospheric chemistry. The similarities of the carbon dioxide (CO2) and OCS molecules within chemical and plant metabolic pathways have led to the use of OCS as a proxy for global gross CO2 fixation by plants (GPP). However, unknowns such as the OCS exchange from soils, where simultaneous OCS production (POCS) and consumption (UOCS) occur, currently limits the use of OCS as a GPP proxy. We estimated POCS and UOCS by measuring net fluxes of OCS, carbon monoxide (CO) and nitric oxide (NO) in a dynamic chamber system fumigated with air containing different [OCS]. Several different soils were rewetted and soil-air exchange monitored as soils dried out to investigate responses to changing moisture levels. A major control of OCS exchange is the total amount of available S in the soil. POCS production rates were highest for soils at WFPS > 60 % and rates were negatively related to thiosulfate concentrations. These soils flipped from being net sources to net sinks of OCS at moderate moisture levels (WFPS 15 to 37 %). By measuring CO and NO while fumigating soils at different levels of OCS, we could show that CO consumption and NO exchange are linked to UOCS under moderate soil moisture. Based on the OCS : CO flux ratio two different UOCS processes could be separated. For one of the investigated soils, we demonstrated changes in microbial activity and red-like cbbL and amoA genes that suggested shifts in the UOCS processes with moisture and OCS concentration. This supports the view that Ribulose-1,5-Bisphosphate-Carboxylase (RubisCO) plays an important role for UOCS and demonstrates a link to the nitrogen cycle.
Prevalencia de agrandamiento y retracción gingival en pacientes con tratamiento de ortodoncia
Authors: Rodríguez Vásquez Ana Gabriela , Fernández García Lourdes Karina , Valladares Trochez Edita Hortensia
Published: May 2018

La clave para el éxito en los tratamientos de ortodoncia van enfocados a un buen diagnóstico, y una excelente comunicación multi e interdisciplinaria con las demás especialidades odontológicas, siempre considerando la prevención como área primordial. El objetivo de este estudio es determinar la prevalencia del agrandamiento y retracción gingival en pacientes con tratamiento de ortodoncia, con el fin de conocer el tipo de alteraciones periodontales prevalentes en pacientes con aparatología ortodóntica.La muestra utilizada es de 200 pacientes que asisten a atención ortodóntica en el Hospital Odontológico Monseñor Agustín Hombach de la Universidad Católica de Honduras; dicha muestra se calculó en base a un universo de 450 personas con un 5% de error muestra constituyéndose esta como muestra aleatoria simple. El instrumento de recolección de datos comprendió: una anamnesis (interrogatorios llenados por el paciente) y la parte de historia clínica (llenada por el investigador) en la cual se observó y midió clínicamente el agrandamiento, retracción gingival y placa bacteriana. Los resultados establecidos en el estudio demostraron que la prevalencia del agrandamiento fue de 110 (55%) pacientes y retracción gingival 21(10%) pacientes, la deficiencia de higiene bucal es prevalente en pacientes con tratamiento de ortodoncia a causa de la aparatología fija que utilizan, los factores de riesgo (dieta, enfermedades sistémicas medicamentos) no agravan el agrandamiento y retracción gingival en dichos pacientes. En el análisis estadístico de correlación utilizado, se comprobaron las hipótesis de investigación que establecen: existe correlación entre el tiempo del tratamiento de ortodoncia y el agrandamiento gingival en pacientes con trata miento de ortodoncia, en la cual hubo una correlación positiva con un índice de significancia de 0.021, y existe correlación entre la edad del paciente y la retracción gingival con un índice de significancia de 0.011, que indica una correlación positiva.
Enfermedad renal oculta en pacientes con rasgo drepanocítico
Authors: Erazo Brian M. , Ramirez Gilberto A. , Yanes Nestor J. , Cerrato Linda E. , Buezo Isis A. , Martel Fabiola C. , Fontecha Gustavo Adolfo
Published: May 2018

El rasgo drepanocítico es casi siempre visto como una condición benigna pero se ha demostrado que puede causar diferentes consecuencias patológicas. Dentro de esta asociación, una de las más importantes, es el riesgo aumentado de enfermedad renal crónica en estos individuos. El presente estudio tiene como objetivo determinar la prevalencia de enfermedad renal oculta en personas identificados con rasgo drepanocítico. Se realizó un estudio descriptivo y transversal en una muestra de la población de la comunidad de Ciriboya, del departamento de Colón, Honduras en enero del año 2015. Participaron 20 personas, mayores de 18 años, las cuales fueron identificadas con rasgo drepanocítico en una investigación previa. Para calcular el riesgo se utilizó la herramienta validada de tamizaje para Enfermedad Renal Oculta (SCORED), se determinaron los niveles de hemoglobina, glucosa en ayunas, tensión arterial y proteinuria, así mismo se registraron antecedentes patológicos y factores de riesgo de cada persona. Los datos fueron ingresados y procesados en el programa Epi info 7 y el nivel de riesgo para enfermedad renal fue calculado mediante los puntajes que este instrumento establece. La muestra estudiada fue de 13 mujeres (65%) y 7 hombres (35%) en un rango de edad entre 19 y 83 años con una SD de 18.4, se encontró una prevalencia de riesgo aumentado de enfermedad renal en el 45% de los sujetos de estudio. Las personas con rasgo drepanocítico deben de recibir un seguimiento clínico especial considerando el riesgo aumentado de padecimiento de enfermedad renal en la población estudiada.
Maladaptive Perfectionism and Psychological Distress: The Mediating Role of Trait Emotional Intelligence
Authors: Fares Aljaser Loulwah Motlaq
Published: May 2018

The study aimed to reveal levels of psychological distress and maladaptive perfectionism at the students of secondary stages in Kuwait schools, and to determine the relationship between those two factors under the effect of trait emotional intelligence. The study sample was composed of (255) students from six schools located in different areas in Kuwait city. A self- administered questionnaire was used as the study instrument for collecting data. It was found that both psychological distress and maladaptive perfectionism were found at medium level, whereas trait emotional intelligence was found at the high level, Moreover it was found that trait emotional intelligence as a mediator affects the psychological distress- maladaptive perfectionism relationship.
An Investigation of Reliability Coefficients Estimated for Decision Studies in Generalizability Theory
Authors: Kamis Omer , Dogan C. Deha
Published: May 2018

This research aimed to compare the G and Phi coefficients estimated in Decision studies in Generalizability theory and obtained in actual cases for the same conditions of similar facets by using crossed design. The research was conducted as pure research on 120 individuals (students), six items and 12 raters. An achievement test composed of six open ended questions and a holistic rubric developed by the researcher were used in data collection. Data analysis included obtaining the G and Phi coefficients by creating actual cases for two, four and six raters followed by D studies conducted for other actual cases with different measurement conditions to make estimates. Finally, G and Phi coefficients obtained and estimated for two, four and six raters were compared separately. Findings show that G and Phi coefficients estimated in D studies by increasing the number of raters were sometimes greater than those obtained in actual cases although they were sometimes smaller. However, it was concluded that a pattern may not always exist between the G and Phi coefficients obtained in actual cases for same number of raters and those estimated in D studies.
The Effect of Group Work on English Vocabulary Learning
Authors: Lin Su-Fei
Published: May 2018

This study investigated the effectiveness of group work (GW) in EFL vocabulary learning by second year, non-English major, university students in Taiwan, in comparison with working individually (IW). The students (N=44) worked in mixed ability groups of 3-4 or in IW to complete vocabulary exercises following reading activities. The classroom intervention followed a repeated measures design with alternating sessions (one week IW, one week GW) for 12 weeks. In order to measure students’ word knowledge gains, the modified vocabulary knowledge scale was used in pre-, post- and delayed-post tests, and the scores from the tests were analyzed with paired t tests. Qualitative information about vocabulary discovery and retention was further obtained from interviews with 24 students conducted after the classroom intervention. Results showed that students’ overall improvement in vocabulary knowledge with group work was significantly higher than that with individual work on immediate post-tests, though both treatments had a beneficial effect. Later retention of word knowledge after GW was only 2% higher than that with IW. Interpretations and implications of these findings are discussed.
Examination of Critical Thinking Skills of Preservice Science Teachers: A Perspective of Social Constructivist Theory
Authors: Demiral Umit
Published: May 2018

The purpose of this study is to examine the critical thinking skills of preservice science teachers in terms of various variables (gender, grade level, academic grade point average, participation in activities) and their opinions. In the research, sequential explanatory design, which is one of the mixed method research designs, was used. The study was carried out with 200 preservice teachers studying at Science Education Department of a state university chosen at Cappadocia region of Turkey. Interviews were conducted with low-level (f=7) and high-level (f=7) preservice teachers selected by means of purposive sampling method from these pre-service teachers participating in the study. Regarding the quantitative and qualitative data obtained; it has been determined that the critical thinking skills of the preservice teachers did not show any significant difference according to gender, grade level and academic grade point average, but there was a significant difference in terms of the activities performed. Preservice teachers expressed that their family structures, social environments in which they interact, and characteristic features were said to be effective in the development of critical thinking skills. Regarding the findings, it has been concluded that trainings that will evoke higher level skills such as critical thinking skills in universities can be effective, but the social and cultural background of the preservice teachers are also effective on these skills. It is recommended to prepare contents that enhance higher level skills such as critical thinking skills as well as education for pedagogy or content knowledge given at universities.
Analyse of the Relation between the Coloured Progressive Matrices Test and the Cognitive Abilities Test Form-6 in the Preschool Period of Gifted Children
Authors: Bildiren Ahmet , Inal Kiziltepe Gozde
Published: May 2018

The diagnosis of preschool gifted children in Turkey has just come up in recent years. Therefore, there is a need for measurement tools that can be applied during the diagnosis phase of preschool gifted children. The aim of this study was to diagnose the relation between the non-verbal and culture-independent Colour Progressive Matrices Test that's frequently used in the international field during the preschool period and the Cognitive Ability Test Form-6, which is a group of tests that assess the cognitive abilities of children in different age groups including verbal, quantitative and nonverbal dimensions, and which is also used in the diagnosis of gifted children in the international arena, to contribute to the diagnosis of preschool gifted children. The sample of the study consisted of 125 children who attended nine preschool education institutions determined by the socio-economic level (low-middle-high) in the central district Efeler of the province Aydin. The mean age of the children is 4.9 and the standard deviation is .8. 49 of the children were girls (39.2%) and 76 were boys (60.8%). Colour Progressive Matrices Test and Cognitive Abilities Test Form-6 were implemented individually to the children. The study revealed that the tests had correlation, the verbal and quantitative dimensions of the Cognitive Abilities Test Form-6 were found to predict the nonverbal cognitive ability of the Coloured Progressive Matrices Test.
The Relationship Between EFL Students’ Word-Knowledge in a Text and Their Reading Comprehension as Demonstrated by Saudi University Students
Authors: AlTameemy Farooq , Daradkeh Amer , Alhamod Abdulhameed
Published: May 2018

This study reports the outcomes of research investigating the relationship between two variables; percentage of word knowledge in an academic English text and reading comprehension scores the participants got for the same text. The study was conducted at Prince Sattam Bin Abdulaziz University, Preparatory Year Deanship, during the first semester of 2017-2018. Seventy-one Saudi male students participated in the study. They came from four groups of students selected from the Preparatory Year population to represent four various levels of English (Groups one, seven, fourteen and seventeen) based on their achievement in the placement test. Data was collected using two instruments: two word—meaning association test-lists and a reading comprehension test. The results showed that there is a statistically significant correlation (r=.702) between percentage of known words and reading comprehension in general i.e., for all the participants. The effect of word knowledge on reading comprehension was very high R square =.49. However, results for the groups separately showed that correlation was positive but not statistically significant for the higher levels i.e., groups one and seven. Also, there was a low effect of word knowledge on comprehension. For the lower levels i.e., groups 14 and 17, the correlation was positive and statistically significant. Results also showed a very high effect of vocabulary knowledge on reading comprehension.Based on the results and analysis of the study, the researchers provided recommendations that will help improve reading curriculum selection and English teaching practices, and suggestions for deeper research into the topic that will include female students and other related concepts.
Educational Values of an External School Project
Authors: Nygren-Landgärds Christina , Elo Janne , Landgärds Ida , Engelholm Margita
Published: May 2018

External organizations offer schools projects with different content, so-called external school projects. This type of external projects is mainly implemented by people or an organization outside of the school. The projects may be within the framework of a nation's political aspirations. The educational goals of the projects are often far-reaching, focusing on personality or attitudes. This article questions whether external school projects can achieve such far-reaching goals. The aim of the research is to explore the views of young adults regarding how participating in an external project influenced them. In-depth interviewing were used when eleven young adults, at the time 25 years old, were asked about their opinions of an external project in entrepreneurship , implemented as an optional course, ten years after taking part. They were asked how they considered the course have influenced them, their choices and their attitudes. The statements of the informants show that the project had some long-term impact. The results of the research provide insight into whether an external temporary school project may have long-term educational values.
Gasorba: ‘stating the obvious’ over parallelle handhaving
Authors: Nijhof B.
Published: May 2018

Gasorba: ‘stating the obvious’ over parallelle handhaving

Het Hof van Justitie oordeelt dat een toezeggingsbesluit ex artikel 9 lid 1 van Verordening (EG) nr. 1/2003 van de Europese Commissie in beginsel niet in de weg staat aan handhaving van Europees mededingingsrecht door nationale rechters en mededingingsautoriteiten ten aanzien van dezelfde feiten waar een toezegginsbesluit op ziet.

HvJ 23 november 2017, zaak C-547/16, Gasorba SL e.a./Repsol Comercial de Productos Petrolíferos SA, ECLI:EU:C:2017:891
Single and multi-frequency impedance characterization of symmetric activated carbon single capacitor cells
Authors: Sopčić Suzana , Antonić Davor , Mandić Zoran , Kvastek Krešimir , Horvat-Radošević Višnja
Published: May 2018

Electrochemical impedance spectroscopy (EIS) technique is used for characterization of single cell symmetric capacitors having different mass loadings of activated carbon (AC). Relevant values of charge storage capacitance (CT) and internal resistance (ESR) were evaluated by the single frequency and multi-frequency analyses of measured impedance spectra. Curve fittings were based on the non-ideal R-C model that takes into account the parasitic inductance, contributions from electrode materials/contacts and the effects of AC porosity. Higher CT and lower ESR values were obtained not only for the cell with higher mass of AC, but also using the single vs. multi-frequency approach. Lower CT and higher values of ESR that are generally obtained using the multi-frequency method and curve fittings should be related to the not ideal capacitive response of porous AC material and too high frequency chosen in applying the single frequency analysis.
Editor’s Note
Authors: Lang Gyözö G.
Published: May 2018

This special issue is the second part of the proceedings of the 6th Regional Symposium on Electrochemistry – South East Europe (RSE–SEE 6), held in Balatonkenese, Hungary, from 11-15 June 2017 (part 1 has been published in J. Electrochem. Sci. Eng. 8(1) (2018)). These are some of the best papers presented at the RSE-SEE6 meeting and reflect the broad interests of the electrochemical community, including both new techniques and application areas. Since its start in 2008, the series of RSE-SEE symposia provides a stimulating international forum for electrochemistry researchers to share their current research results. Following this tradition, more than 110 participants from 24 countries presented papers in Balatonkenese and discussed recent progress in electrochemistry and electrochemical engineering.
Distribution of lip and/or palate clefts types among children form Lodz during years 1981-2015
Authors: Antoszewski Bogusław , Fijałkowska Marta
Published: May 2018

Introduction. Cleft lip and/or palate are the most common face malformations. Clinical picture of these anomalies is very variable. Cleft can include only lip and/or alveolus, palate or all of these structures can be clefted.
Aim. The aim of this paper is to present all particular types of clefts, their relationship to sex and body side in the group of children from Lodz during the years 1981-2015.
Material and method. The study group included 434 patients with facial clefts (218 males and 216 females) in the age between 4 weeks to 18 years.
Results. In the analyzed group there were 181 palate clefts (41.7%), 156 lip and palate clefts (36%) and 97 lip clefts (22.3%). Detailed analysis of clefts types showed that isolated palate clefts are definitely more frequent in females than males (112 vs 69), while lip and palate clefts in boys than girls (96 vs. 60).
Conclusions. During 35 years in children form Lodz the most common type of anomaly were palate clefts, followed by lip and palate clefts and the less frequent were lip clefts. Palate clefts are more common in girls, while lip and palate clefts in boys. Left-sided clefts are two times more common than right clefts.