bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Preconceived Notions and the Lack of Fundamental Skills while Taking General Chemistry
Authors: Gilmore Malinda Wilson , Wilkerson Dwaynia , Hassan Razi
Published: June 2019

Science, Technology, Engineering and Mathematics (STEM) are vital areas of national interest. However, there has been a gradual decline in the number of Bachelor of Science (BS) degrees issued in STEM based disciplines from United States’ colleges and universities. Research indicates too few stu- dents are equipped with the mathematical and analytical skills necessary to be successful in college level mathematics and science courses. Data indicates that millions of people are discouraged from studying mathematics and science because of false assumptions about who has the ability to master these subjects.   It has been shown that in General Chemistry courses some students perform exceptionally well, but a large number of students avoid and/or have a fear of General Chemistry, which results in a high drop/failure/ withdrawal (DFW) rate.   This is coupled with the fact that they enter college ill-prepared in mathematics and lacking analytical and verbal reasoning/critical thinking skills.  This initial negative attitude and deficiency results in a frustrating experience in General Chemistry.  It is for these reasons that a study was performed to address the overall goal of deter- mining the attitudes and identifying the foundational levels of the students from Alabama Agricultural and Mechanical University (AAMU), a Historically Black College and Univer- sity (HBCU), currently enrolled in General Chemistry and at- tempt to determine the effect on their overall success in Gen- eral Chemistry. Subsequently, it was determined that a large percentage of students believe that attitude determines their overall success, but most lack self-confidence.  In addition, some appeared college ready with respect to their mathemat- ical skills, but, they were lacking in verbal reasoning/critical thinking skills. As a result of a negative attitude and a lack of foundational skills, their grades reflected such negativity and over 50% of the students earned a grade of “C” or below. These studies revealed supportive evidence as to why there might be a decline in the number of BS graduates in STEM.
Weighted Pseudo Almost Automorphic Solutions to Nonautonomous Semilinear Differential Equations
Authors: Alsulami Saud M.
Published: June 2019

We consider the existence and uniqueness of Weighted Pseudo almost automorphic solutionsto the non-autonomous semilinear differential equation in a Banach space X :( ) = ( ) ( ) ( , ( )), ' u t A t u t f t u t t Rwhere A(t), t R, generates an exponentially stable evolution family {U(t, s)} andf :R X X satisfies a Lipschitz condition with respect to the second argument.MSC 2010: 43A60; 34G20, 47Dxx
r -homeomorphisms and * r -homeomorphisms
Authors: Jeyanthi M. J. , Missier S. Pious , Thangavelu P.
Published: June 2019

In this paper, the concepts of Λr-homeomorphisms and Λr *-homeomorphisms are introduced and their basic properties are investigated. In particular, it has been shown that Λr *-homeomorphisms form a group under composition.
Genetic Analysis of Root and Shoot Traits in the ‘Essex’ By ‘Forrest’ Recombinant Inbred Line (RIL) Population of Soybean [Glycine max (L.) Merr.]
Authors: Brensha Williams , Kantartzi Stella K. , Meksem Khalid , Grier IV Robert L. , Barakat Abdelali , Lightfoot David A. , Kassem My Abdelmajid
Published: June 2019

Crop productivity is severely reduced by water deficit and drought in many plant species including soybean. Improved root and shoot traits can contribute to drought tolerance ability of the plant. This research was conducted to identify QTL that underlie several root and shoot traits in the ‘Essex’ by ‘Forrest’ (ExF RILs, n=94) recombinant inbred line (RIL) soybean population. Field collected samples were used for gathering phenotypic data of basal root thickness (BRT), lateral root number (LRN), maximum root length (MRL), root fresh weight (RFW), root dry weight (RDW), shoot fresh weight (SFW), shoot dry weight (SDW), and calculating RFW/SFW, and RDW/SDW ratios. All traits and ratios were compared against DNA markers using the composite interval mapping (CIM). A total of 12 QTL: 3 for MRL, 1 QTL for LRN, 1 QTL for BRT, 2 QTL for RFW, 2 QTL for RDW, 4 QTL for SFW, 3 QTL for SDW, and 3 QTL for SFW/SDW were identified and mapped on different linkage groups (LGs) A2, B2, C2, D1a, F, G, and N. The LOD scores of these QTL ranged from 2.5 to 6.0. No QTL were associated with RFW/RDW. The root and shoot trait QTL of this study may benefit breeding programs for producing cultivars tolerant to water deficit and high yield. Preliminary analyses of genes the QTL regions using GO annotation gave insight into genes that may underlie some of these QTLs.
Genetic Analysis of Relative Water Content (RWC) in Two Recombinant Inbred Line Populations of Soybean [Glycine max (L.) Merr.]
Authors: Virginia Salvador , Pagan Megan , Cooper Melissa , Kantartzi Stella K. , Lightfoot David A. , Meksem Khalid , Kassem My Abdelmajid
Published: June 2019

Drought affects soybean [Glycine max (L.) Merr.] and other crops productivity in the US and other parts of the world. Relative water content (RWC) is an important indicator for plant water deficit tolerance (WDT). The objective of this study is to map quantitative trait loci (QTL) for RWC and several other leaf traits such as leaf dry weight (LDW), leaf fresh weight (LFW), and leaf turgid weight (LTW) in two soybean recombinant inbred line (RIL) populations, one derived from a cross of ‘Essex’ and ‘Forrest’ (ExF, n=94) and the other is derived from a cross of ‘PI 438489B’ and ‘Hamilton’ (PIxH, n=50). In the PIxH RIL population, eight QTL were identified and mapped on 6 different linkage groups (LGs) of the soybean genome. No QTL for LFW were identified in this population. In the ExF RIL population, 10 QTL were identified and mapped on 5 different LGs of soybean. Chromosome 18 (LG G) contains clusters of QTL for LFW, LTW, and RWC in the ExF RIL population. This same chromosome contains a QTL for RWC in the PIxH RIL population. The QTL found here are important to be included in breeding programs for soybean water deficit tolerance (WDT).
Ocean acidification reduces growth and grazing of Antarctic heterotrophic nanoflagellates
Authors: Deppeler Stacy , Schulz Kai G. , Hancock Alyce , Pascoe Penelope , McKinlay John , Davidson Andrew
Published: June 2019

Abstract. High-latitude oceans have been identified as particularly vulnerable to ocean acidification if anthropogenic CO2 emissions continue. Marine microbes are an essential part of the marine food web and are a critical link in biogeochemical processes in the ocean, such as the cycling of nutrients and carbon. Despite this, the response of Antarctic marine microbial communities to ocean acidification is poorly understood. We investigated the effect of increasing fCO2 on the growth of heterotrophic nanoflagellates (HNF), nano- and picophytoplankton, and prokaryotes in a natural coastal Antarctic marine microbial community from Prydz Bay, East Antarctica. At CO2 levels ≥ 634 μatm, HNF abundance was reduced, coinciding with significantly increased abundance of picophytoplankton and prokaryotes. This increase in picophytoplankton and prokaryote abundance was likely due to a reduction in top-down control of grazing HNF. Nanophytoplankton abundance was significantly elevated in the 634 and 953 μatm treatments, suggesting that moderate increases in CO2 may stimulate growth. Changes in predator-prey interactions with ocean acidification could have a significant effect on the food web and biogeochemistry in the Southern Ocean. Based on these results, it is likely that the phytoplankton community composition in these waters will shift to communities dominated by prokaryotes, nano- and picophytoplankton. This may intensify organic matter recycling in surface waters, leading to a decline in carbon flux, as well as a reducing the quality and quantity of food available to higher trophic organisms.
Mapping landscape connectivity under tectonic and climatic forcing
Authors: Salles Tristan , Rey Patrice , Bertuzzo Enrico
Published: June 2019

Abstract. Species distribution and richness ultimately result from complex interactions between biological, physical and environmental factors. It has been recently shown for a static natural landscape that the elevational connectivity, which measures the proximity of a site to others with similar habitats, is a key physical driver of local species richness. Here we examine changes in elevational connectivity during mountain building using a landscape evolution model. We find that under uniform tectonic and variable climatic forcing, connectivity peaks at mid-elevations when the landscape reaches its geomorphic steady-state and that orographic effect on geomorphic evolution tends to favour low connectivity on leeward facing catchments. Statistical comparisons between connectivity distribution and results from a metacommunity model confirm that landscape elevation connectivity explains to the first order species richness in simulated mountainous regions. Our results also predict that low connectivity areas which favour isolation, a driver for in-situ speciation, are distributed across the entire elevational range for simulated orogenic cycles. Rapid adjustments of catchment morphology after cessation of tectonic activity should reduce speciation by decreasing the number of isolated regions.
Validation of the sea ice surface albedo scheme of the regional climate model HIRHAM–NAOSIM using aircraft measurements during the ACLOUD/PASCAL campaigns
Authors: Jäkel Evelyn , Stapf Johannes , Wendisch Manfred , Nicolaus Marcel , Dorn Wolfgang , Rinke Annette
Published: June 2019

Abstract. For large-scale and long-term Arctic climate simulations appropriate parameterization of the surface albedo is required.
Therefore, the sea ice surface (SIS) albedo parameterization of the coupled regional climate model HIRHAM–NAOSIM was examined against broadband surface albedo measurements performed during the joint ACLOUD (Arctic CLoud Observations Using airborne measurements during polar Day) and PASCAL (Physical feedbacks of Arctic boundary layer, Sea ice, Cloud and AerosoL) campaigns, which were performed in May–June 2017 north of Svalbard. The SIS albedo parameterization was tested using measured quantities of the prognostic variables surface temperature and snow depth to calculate the surface albedo and the individual fractions of the ice surface subtypes (snow-covered ice, bare ice, and melt ponds) derived from digital camera images taken on board the Polar 5 and 6 aircraft.
The selected low-altitude (less than 100 m) flight sections of overall 12 flights were performed over surfaces dominated by snow-covered ice. It was found that the range of parameterized SIS albedo for individual days is smaller than that of the measurements. This was attributed to the biased functional dependence of the SIS albedo parameterization on temperature. Furthermore, a time-variable bias was observed with higher values compared to the modeled SIS albedo (0.88 compared to 0.84 for 29 May 2017) in the beginning of the campaign, and an opposite trend towards the end of the campaign (0.67 versus 0.83 for 25 June 2017). Furthermore, the surface type fraction parameterization was tested against the camera image product, which revealed an agreement within 1 %.
An adjustment of the variables, defining the parameterized SIS albedo, and additionally accounting for the cloud cover could reduce the root-mean-squared error from 0.14 to 0.04 for cloud free/broken cloud situations and from 0.06 to 0.05 for overcast conditions.
Adaawk: Thinking and being in our hearts--Sharing the reflections of Otsin, Gitxsan rural indigenous nursing practice
Authors: Blackstock Sheila
Published: June 2019

Adaawk is oral history shared through the reflections of the first offering of a Gitxsan rural nursing practice course in follow up to the publication Otsin: Sharing the spirit of an indigenous nursing practice course development. In the spirit of adaawk, the Gitxsan’s reflections of the Gitxsan nursing practice course are themed using the metaphor of a totem pole. Each concept, and partnerships are integral to the development of a totem that reflects the adaawk. The purpose of this article is to demonstrate how the co-creation of relational concepts with the community strengthens preceptor, student and community partnerships for improved preceptor support and student learning outcomes. The author’s reflections demonstrate how the rural Gitxsan nursing practice experience informs the co-creation of cultural safety knowledge. Further, the experience provides a safe forum for students to practice cultural safety and relational practice. It allows students to co-create innovative patient outcomes within rural and community nursing practice context reflecting a two-eyed seeing approach. Students give back to communities through facilitated student placements in leadership/community health nursing for a fourth year nursing practice project with Gitxsan and rural communities in follow up to their third year practice. Authentic community partnerships and co-creation are foundational to enacting relational practice to nursing practice course development, consultation, and cultural safety practice. Learning outcomes of the course are revised to strengthen the parts of the totem and ultimately the essence of adaawk.
Remittances, Governance and Economic Growth: Empirical Evidence from MENA Region
Authors: Saad Wadad , Ayoub Hassan
Published: June 2019

In this study we examine the effects of remittances and governance on economic growth in ten MENA countries. We choose these countries because they have relatively stable political situations. Using annual data from the World Bank over the period 2002-2017, we estimate panel autoregressive distributed lag (ARDL) models due to the existence of mixed levels of integration among series involved in this study. Control variables such as gross capital formation, consumption per capita and openness among others are integrated in these models. A governance composite is computed using the 6 governance indicators from the world bank. These indicators are used individually in different ARDL models with their interactions with the remittances to explore their impact on economic growth. The findings indicate a negative impact of the remittance on economic growth in the quasi-totality of the models. However, while governance composite shows a positive impact on economic growth, taking into consideration the dimensions of governance leads to conflicting results.
The Effect of the Reliability of Accounting Information Systems on Electronic Disclosures on the Stock Prices: Applied Study on Industrial Companies Listed on Amman Stock Exchange
Authors: Syaeid Thaker A.
Published: June 2019

The study aims at identifying the impact of the reliability of the accounting information systems (security, confidentiality, privacy, the integrity of processes and readiness) on the stock prices of Jordanian industrial companies in Amman Stock Exchange and determining the effect of electronic disclosures (the appropriate timing, predictability and ability to reorganizing) in improving that impact; depending on the descriptive analytical approach, the questionnaire was designed and distributed to the sample of the study composed of directors of financial departments and divisions related to financial issues, monitoring and internal audit and information technology at industrial companies listed on Amman Stock Exchange, with the average of two questionnaires in each company. The number of questionnaires retrieved and statistically analyzed (118), (90.8%) of distributed questionnaires. The results of the multiple regression analysis showed a statistically significant effect on the reliability of accounting information systems in their dimensions (security, confidentiality, privacy, integrity of processes, and readiness) on the stock prices of Jordanian industrial companies in Amman Stock Exchange, where the moral effect appeared in all dimensions, except (security, integrity of processes). The results of the regression analysis showed that electronic disclosures were represented by (the appropriate timing, predictability and ability to reorganizing) which lead to improve the effect of accounting information systems on the stock prices of Jordanian industrial companies in Amman Stock Exchange. The study recommended to increase the level of interest in the reliability of accounting information systems, and to increase the level of its application and activation in the Jordanian industrial companies, because of its role in improving the performance of the company, and maximize their market value through its accounting information to shareholders of accurate, convenience, timely, reliable, consequently ensuring their survival and continuity, and to increase the awareness of the management of Jordanian industrial companies and financial statements preparers about the importance of electronic disclosure and the benefits it achieves in addition to the resulting risks, and adopt effective procedures to verify the security and reliability of accounting information that electronically disclosed and to transmit the information securely by users.
Management van stedelijke ontwikkeling
Authors: van Bueren Ellen
Published: June 2019

Urban Development Management: Governing institutional change in support of sustainable cities

With her chair in urban development management, Ellen van Bueren investigates policy, governance and management issues. Cities, as economic and cultural centres in our society, are major consumers of resources. They not only contribute to problems such as climate change, but also experience the risks and consequences thereof. Technological solutions to these problems are difficult to implement. They require larger-scale system changes, or encounter resistance. Making cities sustainable not only requires technical solutions, but also institutional innovation. A socio-technical-ecological system approach to cities shows the coherence and complexity of issues. Issues play on multiple scales, are cross-sectoral, and require an interaction of citizens, companies, and governments. Moreover, the playing field between these groups of actors is changing rapidly, technological empowerment in particular has made the citizen a much more equal player alongside the government and business. Existing instruments and approaches are not sufficient to approach sustainability issues. To identify and address these issues, cooperation between science and society is necessary. Multi- and transdisciplinary learning environments enable researchers and students to identify issues, to answer questions and to try out solutions together with stakeholders. Such environments are indispensable for the development of sustainable cities.
Van wie is de verzorgingsstaat?
Authors: Fenger Menno
Published: June 2019

Whose welfare state? Public administration as self-administration

The work of Elinor Ostrom suggests that under certain conditions local communities are better able to sustainably manage so-called common pool resources than an external party such as government. In this article I explore whether and to what extent those conditions also apply to the governance of the Dutch welfare state. I show that in the current participation society there are numerous examples in which self-governance seems to be successful and in which Ostrom’s conditions seem to play an important role. On that basis, I come to the conclusion that citizens – under certain institutional conditions – may be better able to resolve social problems among themselves than through external interventions. This requires a shift from public administration to self-administration.
Concordantie en maatschappelijke opvattingen – deel twee
Authors: Lewin G.C.C.
Published: June 2019

Concordantie en maatschappelijke opvattingen – deel twee

In dit opvolgende artikel bespreekt de auteur in het licht van het concordantiebeginsel waarom het problematisch is de maatschappelijke opvattingen als rechtsbron te aanvaarden.
Estruturas latentes de coesão comunitária: estudo multiplexo em duas comunidades populares de Belo Horizonte (Brasil)
Authors: Salej Higgins Silvio
Published: June 2019

A condição multiplexo das relações sociais constitui o objeto central da chamada sociologia neoestrutural. A multiplexidade abarca o conjunto de mecanismos que explicam a emergência de formações sociais. Eis a ideia força de Harrison White: as identidades em busca de controle pulam entre diferentes domínios de redes dando origem a novos papeis sociais ou tipos organizacionais dentro do espaço social. Modelar a condição múltipla dos laços sociais tem sido um desafio da comunidade de cientistas sociais que apelam para a análise de redes. Após o pioneiro método CONCOR introduzido por White et al (1976), novas soluções têm sido procuradas visando critérios de ajuste ótimos e interpretáveis entre os blocos ou clusters de atores do sistema multiplexo. Fizemos um estudo comparativo entre a elite de lideranças de duas comunidades populares da cidade de Belo Horizonte (Brasil), uma com um histórico de violência e criminalidade e outra relativamente pacífica. Visamos entender estruturas latentes de coesão em cada sistema comunitário, a partir de dados multiplexo que incluem relações para a troca de informação, reconhecimento ou status e colaboração. Foi feita uma análise de blocos utilizando o pacote computacional Integrated Classification Likelihood (ICL) disponível em R. Os resultados permitiram descobrir duas estruturas latentes bem diferenciadas em termos da coesão da elite de lideranças, uma de tipo markoviano ou triádico e outra de circuito social para além da tríade.
GA Based Selective Harmonic Elimination for Multilevel Inverter with Reduced Number of Switches: An Experimental Study
Authors: Bektas Enes , Karaca Hulusi
Published: June 2019

In power electronic applications, especially high power and medium voltage, multilevel inverters (MLIs) have been commonly used. MLIs ensure high quality load voltage and lower Total Harmonic Distortion (THD) than traditional inverter. In this paper, a multilevel inverter structure with reduced number of power switches is proposed. The proposed multilevel inverter is lower costed than conventional MLI. Also, a Genetic Algorithm (GA) based Selective Harmonic Elimination (SHE) technique has been used for the first time in the proposed MLI structure with reduced number of switches. The proposed GA based SHE technique computes the optimum switching angles by solving nonlinear harmonic equations of multilevel inverter. Both Isochronous switching (IS) and SHE techniques have been applied to proposed MLI to demonstrate the effectiveness of the GA based SHE technique. Simulation and experimental results for 7, 11 and 13-level have been obtained. Results of 11-level inverter is analysed and given in detail. Results have clearly proved that desired order harmonics in proposed MLI topology can be eliminated by using GA based SHE technique and lower THD on the load voltage has been provided.
Design an Identification Function to Reduce the Computational Resources on the Testing Process of an Analog Electronic Circuit
Authors: Temich Sebastian , Golonek Tomasz , Grzechca Damian
Published: June 2019

In modern electronic circuits, imperfectness in the technological process can cause errors in reaching the correct values of the functional parameters. In order to solve this problem, a novel approach of analog and mixed-signal circuit testing methodology is used. The presented approach allows the testing complexity to be reduced and the testing time to be decreased. For this paper, selected signal features were designated from the transient output signal response. Using regression models with the extracted signal features, the functional parameters of a circuit were determined. An evolutionary determination of the regression models enabled the efficiency of the identification process to be maximized. The proposed methodology is presented for an exemplary CMOS Dickson charge pump circuit.
Novel Reconnection-Less Reconfigurable Filter Design Based on Unknown Nodal Voltages Method and Its Fractional-Order Counterpart
Authors: Langhammer Lukas , Sotner Roman , Dvorak Jan , Jerabek Jan , Ushakov Peter A.
Published: June 2019

A novel solution of reconnection-less electronically reconfigurable filter is introduced in the paper. The filter is designed based on unknown nodal voltages method (MUNV) using operational transconductance amplifiers (OTAs) and variable gain amplifier (VGA). The structure can provide all-pass, band-stop, high-pass 2nd order functions, high-pass function of the 1st order and direct transfer from the same topology without requirement of manual reconnection. The proposed structure also offers the electronic control of the pole frequency. Moreover, fractional-order design of the proposed filter is also provided. The behaviour is verified by simulations using Cadence IC6 (spectre) software.
Current Trends and Advances in Image Quality Assessment
Authors: Okarma Krzysztof
Published: June 2019

Image quality assessment (IQA) is one of the constantly active areas of research in computer vision. Starting from the idea of Universal Image Quality Index (UIQI), followed by well-known Structural Similarity (SSIM) and its numerous extensions and modifications, through Feature Similarity (FSIM) towards combined metrics using the multi-metric fusion approach, the development of image quality assessment is still in progress. Nevertheless, regardless of new databases and the potential use of deep learning methods, some challenges remain still up to date. Some of the IQA metrics can also be used efficiently for alternative purposes, such as texture similarity estimation, quality evaluation of 3D images and 3D printed surfaces as well as video quality assessment.
Effect of Aerobic Training and C. vulgaris Intake on Lipid Profile and Leptin in Obese Women
Authors: Karbalamahdi Afsaneh , Abedi Bahram , Fatolahi Hoseyn , Pazoki Alireza
Published: June 2019

Background: Regular physical activity can reduce the complications of obesity. Chlorella vulgaris (C. vulgaris) is recognized as a rich source of health promotion. Objectives: The aim of this study was to evaluate the effect of aerobic training and C. vulgaris intake on lipid profile and leptin in obese women. Methods: We randomly divided 32 obese women into control (C), aerobic training (AT), C. vulgaris (CV), and aerobic training plus C. vulgaris (AT+CV) groups. Interventions were performed for eight weeks. C. vulgaris was used at the dose of 1200 mg/day. The aerobic training included activities on a treadmill with 65% - 80% of maximum heart rate (MHR) (three sessions/week). Blood samples were taken before and after the interventions. Results: The body weight, body mass index (BMI), leptin, triglyceride, cholesterol, HDL-C, and LDL-C significantly improved in the AT and AT+CV groups compared to the control group (P < 0.05). There was no significant difference between the AT and AT+CV groups (P > 0.05). Conclusions: Aerobic training can improve the lipid profile and leptin in obese women by reducing weight, increasing oxygen uptake, and improving lipid oxidation. Nevertheless, the effect of C. vulgaris was not detected individually. However, the effect of training may be due to the modification of exercise-induced responses by C. vulgaris properties. Therefore, there is a need for further investigation of C. vulgaris physiological function in the field of sports medicine.
O MANIFESTO DA TRANSCONSTITUCIONALIDADE PARA PRESERVAÇÃO DO MEIO AMBIENTE
Authors: Rocha Leonel Severo , Scherbaum Julia Francieli Neves de
Published: June 2019

O artigo inscreve-se no campo dos estudos da sociologia constitucional para efetivação do direito ambiental ecologicamente equilibrado à luz do transconstitucionalismo, tem como objetivo problematizar o fenômeno do transconstitucionalismo e seus reflexos na proteção ambiental. Para tanto, apresenta uma síntese dos crimes ambientais e a cooperação entre os estados. Por fim analisa-se a implantação da proteção ambiental a cerca da atuação do transconstitucionalismo, especialmente, as posições de C. Thornhill, G. Teubner e L. S. Rocha. Quanto à Metodologia, é a matriz pragmático-sistêmica, evidenciando sua influência nos estudos atuais acerca da sociologia do constitucionalismo. Tal percurso possibilita constatar ao direito ambiental a necessária transição entre perspectivas teóricas no atual cenário, propõem que seja a partir da elaboração de um transconstitucionalismo, visando o aproveitamento das experiências de ordens jurídicas externas e a cooperação entre os estados, bem como a informação e participação da coletividade de cunho ambiental, que são essenciais ao aperfeiçoamento de uma cultura global de preservação ambiental.
Choosing and Justifying Robust Methods for Educational Research
Authors: Cai Jinfa , Morris Anne , Hohensee Charles , Hwang Stephen , Robison Victoria , Cirillo Michelle , Kramer Steven L. , Hiebert James
Published: June 2019

In our recent editorials (Cai et al., 2019a, 2019b), we discussed the important roles that research questions and theoretical frameworks play in conceptualizing, carrying out, and reporting mathematics education research. In this editorial, we discuss the methodological choices that arise when one has articulated research questions and constructed at least a rudimentary theoretical framework. Just as the researcher must justify the significance of research questions and the appropriateness of the theoretical framework, we argue that the researcher must thoroughly describe and justify the selection of methods. Indeed, the research questions and the theoretical framework should drive the choice of methods (and not the reverse). In other words, a sufficiently well-specified set of research questions and theoretical framework establish the parameters within which the most productive methods will be selected and developed.
DESIGN OF FLUID CONCRETE WITH SYNTHETIC ADDITIVES 4TH GENERATION (OR ESTERIC REPULSION)
Authors: SAEZ PEREZ MARI PAZ , VERDU VAZQUEZ AMPARO , AGUILAR  ALARCON MERCEDES
Published: June 2019

By definition, the self compacting concrete is recognized as a main characteristic is the capacity to flow and filling volume of poring concrete by the action of its own weight. The natural composition of the materials is the same for a conventional concrete (cement, aggregates, additions, additives and water). Its ability to be self compacting is due mainly to the high content in fines, to the low content in fine in thick granulometry and the high doses of additives. The present work tackles the research carried out on self-compacting concrete and the chemical additives used in its manufacture, specifically the so-called last generation or superplasticizers known as fourth generation additives or polycarboxylates. Differentiating theme, not depending on the brand or the manufacturer if not depending of their molecular structure, which it results to the creation of long chain additives or short chain additives. The key to obtaining a good HAC characterized by a high cohesion and with self-compacting properties lies in the correct optimization of the superplasticizer-additive combination (viscosity modifier). Therefore, the materials used have been the main part of the study to achieve the proposed objectives, guaranteeing the compatibility between them, the water/cement ratio and the achievement of established resistances stand out. The results obtained show the goodness of the 4th generation additives and show that the use of a correct granulometric curve together with the use of short chain or long chain additives gives us a significant variation in the strength of the concrete. Giving, sometimes, the option of dispensing with the use of different additions to obtain the improvement of results with the use of the additives tested.

Keywords: concrete, self compacting, additives-4ª-generation.
THERMAL PERFORMANCE UNDER WINTER CONDITIONS OF A REFLECTIVE INSULATION BASED WALL PANEL FOR EMERGENCY HOUSES IN CHILE
Authors: GALVEZ HUERTA MIGUEL ANGEL , HORMAZABAL POBLETE NINA , SILLS GARRIDO PABLO , GIL LOPEZ TOMAS , FELICES PUERTOLAS RUBEN
Published: June 2019

Casa FÉNIX solution for the emergency is a modular and progressive construction system based on a prefabricated timber structure that provides a great variety of growing possibilities. This initiative, originally conceived to take part in the 2014 Solar Decathlon Europe Competition, is central to many research activities carried out by the Department of Architecture of the Santa María Technical University of Valparaíso, Chile, the most recent of which is the FONDEF IDeA project “Systematization of non-structural components for an emergency house”
Within the framework of this research, a lightweight, easy-to-assemble, low-cost wall solution has been developed. It consists on a sandwich panel composed of an expanded polystyrene (EPS) core and a cardboard honeycomb reinforcement on both sides, which constitutes air chambers. The inclusion of reflective layers on each of the sides of the air chambers significantly increases the thermal resistance of the element with no significant weight increase.
The work addresses the winter performance of the aforementioned wall element variations, characterized by their thermal transmittances, U. The study has been carried out with analytical (UNE-EN-ISO 6946) and computational (THERM) models, which have been compared and validated by means of experimental tests.
Transmittance tests carried out for different variations of the solution show compliance with the regulatory requirements for the three climatic zones of central Chile that gather 60% of the country's population. From these data a complete set of alternatives have been developed in order to respond to the different thermal demands of nine climatic zones of the country, that range from the aridity of the Atacama Desert to the cold Patagonian regions.

Keywords: Vivienda de emergencia, Panel de fachada, Aislamiento reflectivo, Simulación térmica. Transmisión de calor.
COMPARISON OF INFLUENCE OF THERMAL CYCLES ON THERMO-ACTIVATED STRUCTURES WITH RESPECT TO PREDICTED MODELS ESTABLISHED IN THE MODEL CODE 2010
Authors: PRIETO BARRIO MARIA ISABEL , HOSOKAWA MENENDEZ KENZO , GARCIA LOPEZ DE LA OSA GREGORIO , GONZALEZ RODRIGO SONSOLES
Published: June 2019

Global warming and increasing CO2 emissions make it necessary to reduce energy consumption while maintaining thermal comfort. The current trend advocates the combination of energy conservation strategies and energy efficiency technologies and therefore thermoactive structures play an important role.
The Model Code 2010 establishes a model of the effect of temperature on the compressive, flexural and tensile strength for normal concretes, but this model only takes into account the effect of temperature, thus neglecting the age of the concrete, as well as the effect produced by thermal cycles over time.
This article examines the behaviour of concrete subjected to thermal cycles, thus imitating the process of thermal loading and unloading in thermoactivated structures throughout its period of use. Cylindrical specimens have been made to study compression behaviour and tensile strength, and prismatic specimens have been made to determine flexural strength. The results obtained have been compared with the models established in the 2010 model code, and large differences can be observed between them. It can be concluded that the models established in the model code do not describe the behaviour of the concrete subjected to thermal cycles.
Keywords: Plain concrete, temperature-related & thermal effects, testing, thermoactive
INFLUENCE OF THE CONSTRUCTION PROCESSIN THE MULTILAYER LIGHTWEIGHT CONCRETE BEAM BEHAVIOUR
Authors: OLMEDO ZAZO FERNANDO ISRAEL , CARRILLO  ALONSO LUIS , VALIVONIS JOUZAS , MARTINEZ PEREZ INMACULADA
Published: June 2019

When a multilayer concrete beam is built, several concrete mixtures could be poured sequentially. Usually concrete used in external layers are higher resistance than those placed in internal layers. Time between the pouring of the different layers could have influence on the beam behaviour. The goal of this paper is to study how temporary offset on manufacturing the multilayer concrete beams has influence on their mechanical behaviour. Some has test have been run out to some beams which let us know the different behavior between each other. Finally it has been determinate if the construction process is the cause or other factors lead to produce the founded differences.
BEHAVIOUR OF MASONRY MORTARS FABRICATED WITH RECYCLED AGGREGATE TOWARDS MOISTURE
Authors: MORON FERNANDEZ CARLOS , FERRANDEZ VEGA DANIEL , SAIZ MARTINEZ PABLO , FERNANDEZ MARTINEZ FRANCISCO
Published: June 2019

One of the most frequent defect in building is appearance of moisture. Due to the growing social awareness and environmental policy, it becomes necessary to evaluate the behaviour of a new construction materials regarding this kind of defects. This paper studies the behaviour of masonry mortars incorporating three types of recycled aggregates: concrete, ceramic and mixed, with dosages 1:3 and 1:4 to be compared to the behaviour of traditional mortars in terms of absorption by capillarity, rainwater penetration and water vapour permeability. The results show that under condition of water absorption by capillarity or heavy rains, ceramic recycled aggregate has the poorest behaviour due to its high mix water absorption. Moreover, water vapour permeability is higher in mortars performed with recycled aggregates, minimizing in this way the condensation that can be produced in interior spaces.

Key words: masonry mortar, recycled aggregate, moisture, defect.
MECHANICAL PERFORMANCES OF CEMENT-GYPSUM COMPOSITE MATERIAL CONTAINING A WEAK INTERLAYER WITH DIFFERENT ANGLES
Authors: LUO PINGPING , WANG SHUREN , HAGAN PAUL , HUANG QINGXIANG , CAO CHEN , GAMAGE KANCHANA
Published: June 2019

The stability of engineering rock mass mainly depends on the mechanical properties of the structural plane. It is difficult to study the mechanical properties of the rock mass without considering the concealment of the structural plane. To study the influence of weak interlayer on mechanical performances of rock-like material with different angles, thicknesses and mechanical parameters, the compression tests were carried out on cement material with gypsum weak interlayer, combined with Mohr-Coulomb criterion analysis and FLAC3D modelling test. Results show that the confining pressure and the weak interlayer play the control role on the strength, deformation and failure modes of the rock-like material. The confining pressure can effectively restrain the stiffness and strength weakening due to weak interlayer of the rock-like material. The strength, elastic modulus and failure characteristics of the rock-like material show strong structural effects. The inclination angle of the structural plane is close to 60°, the strength and stiffness weakening are more obvious. When the inclination angle of the structural plane is close to 0° and 90°, the composite material is mainly characterized by splitting failure; when the inclination angle is close to 15°, the material mainly exhibits shear failure. In other cases, the material mainly exhibits tensile and shear failure modes. The results can provide the theoretical and technical basis for similar engineering practice.

Keywords: Rock-like material, Weak interlayer, Compression test, Numerical simulation
INNOVATION AND DIGITAL TRANSFORMATION IN BUILDING SECTOR
Authors: GUTIERREZ GARCIA FRANCISCO JAVIER
Published: June 2019

After the end of the crisis in the sector, the gap between the requirements of the real estate product and the reality of the sector was distant and mainly of a regulatory nature. The new requirements of the Technical Building Code (CTE) of multiple character and of recent approval then, contrasting with the standstill of the sector, had a delay in the application of the same ones in all the levels. The progressive response of the building sector has focused on the search for proposals and solutions that provide maximum reliability and performance to building investors and users, as well as the efficiency and safety of the building product. Housing is a relevant product in society, mainly private initiative, which affects economic growth and creates interference in many sectors.
Evaluation of energy balances and greenhouse gas emissions from different agricultural production systems in Minqin Oasis, China
Authors: Yan Zhengang , Li Wei , Yan Tianhai , Chang Shenghua , Hou Fujiang
Published: June 2019

Agricultural production in Minqin Oasis, China, is commonly categorized as intensive crop production (ICP), integrated crop–livestock production (ICLP), intensive livestock production (confined feeding) (IFLP), and extensive livestock production (grazing) (EGLP). The objectives of the present study were to use a life cycle assessment technique to evaluate on-farm energy balances and greenhouse gas (GHG) emissions of agricultural production, and to compare the differences among the four systems. Data used in the present study were collected from published literature and face-to face questionnaires from 529 farms in eight towns (two towns per production system) within Minqin county. The ANOVA of averaged data from 2014 to 2015 indicated that the net energy ratio (Output/Input) for the EGLP system was significantly higher than that for any other system (P< 0.01), whereas the difference among other three systems were not significant. The EGLP system generated lower CO2-eq emissions per hectare of farmland than other systems (P< 0.01). Relating carbon economic efficiency to market values (US$) of agricultural products, indicated that the carbon economic efficiency (US$/kg CO2-eq) of the IFLP system was significantly greater than that of other systems (P< 0.01). The major GHG emission sources varied across the systems, that is, soil respiration is the dominant source in EGLP, while the main sources in IFLP are enteric methane and manure management; in ICLP major sources are enteric methane, soil respiration and fertilizer; and in ICP are soil respiration and fertilizer. The structural equation modelling analysis showed that livestock category was strongly linked to net income. The direct effects and total effects of water use efficiency, via its positive influence on energy balances and GHG emissions were much stronger than those of other dependent variables. The study provides important benchmark information to help develop sustainable agricultural production systems on energy balances and GHG emissions in northwestern China.
Recruitment of cyanobacteria by reverse transcription quantitative real-time PCR based on expression of Microcystis gene
Authors: Yu Long , Wu Xiaofei , Yu Yang , Shi Limei , Zhang Min
Published: June 2019

In this study, a SYBR Green quantitative real-time PCR method was established and applied. Relative expression of the synthetic genes from Microcystis gas vesicles (gvpC), algal toxin genes (mcyA), and polysaccharides (espL) from water and sediments of Meiliang Bay and from the center of Lake Taihu were tested from January to June, 2017. Indoor Microcystis aeruginosa was used as the control group. The kit for total RNA extraction in Microcystis was optimized. Results showed that the optimized kit extracted high-concentrations and high-quality total RNA from Microcystis. The extraction purity and concentration were significantly higher than those extracted by the original kit. The transcription level of gvpC increased gradually until a peak was reached in March. However, expression of gvpC decreased continuously at the proliferating and floating stages of Cyanobacterial biomass. The maximum level of expression of gvpC in April in comparison to expression of mcyA in March occurred first. We found that the SYBR Green qRT-PCR method, which is characterized by high specificity, repeatability, is rapid, and can be used for quantitative detection of expression of gvpC, mcyA, and espL. The recruitment of cyanobacteria is the process in which cyanobacteria in the sediment began to regain their activity, started to grow and migrated to the water column.
Análisis de vídeos sobre cáncer de mama en YouTube
Authors:   Universidade de Vigo (España), Míguez-González María Isabel , García Crespo Oswaldo ,   Universidade de Vigo (España), Ramahí-García Diana ,   Universidade de Vigo (España)
Published: June 2019

El artículo estudia las características y fiabilidad de 76 vídeos de YouTube sobre cáncer de mama, relacionándolas con su repercusión y valor para los usuarios. El análisis se basa en una plantilla que incluye elementos cuantitativos y cualitativos. Los resultados muestran una gran diversidad de formatos y promotores, frente a una mayor uniformidad en cuanto al tipo de contenido y el tono. Aunque predominan los vídeos informativos de tono neutral, los datos reflejan la preferencia de los usuarios por vídeos más subjetivos y menos fiables.
Study of α*-Homeomorphisms by α*-closed Sets
Authors: Vithyasangaran K. , Elango P.
Published: June 2019

In this paper, we introduce a new kind of closed sets called α* -closed sets in a topological space and investigate their properties. These closed sets are compared with the closed sets and the generalized closed sets. We also introduce the α* -homeomorphisms and develop their properties by using the α* -closed maps and α* -continuous maps.
Effect of Triple Super Phosphate on the Growth and Yield of Boro Rice in Haor Areas of Sunamganj District in Bangladesh
Authors: Goswami B. K. , Kashem M. A. , Aziz M. A. , Saha T. K.
Published: June 2019

A field experiment was conducted at Bilpar village of Sunamganj district in Bangladesh during November 2016 to May 2017 to find out the effects of Triple Super Phosphate (TSP) fertilizer on the growth and yield of boro rice in haor areas. Two factors viz. varieties (BRRI dhan29 and BRRI dhan58) and six TSP fertilizer levels [F1- 85 kg TSP ha-1 (Farmers’ practice), F2- 142 kg TSP ha-1, F3- 127 kg TSP ha-1, F4- 112 kg TSP ha-1 (BARC recommended dose), F5- 97 kg TSP ha-1, F6- 82 kg TSP ha-1] were included in the experiment. The experiment was conducted in the farmers’ field and laid out in a RCBD with three replications. Data were taken on plant height and tillers hill-1 at 15 days intervals. The yield and yield contributing parameters were also taken at harvest. Plant height, number of total tillers, effective tillers hill-1, panicle length, sterile spikelets, 1000 grain weight, grain and straw yield varied significantly due to variety. BRRI dhan58 produced higher number of effective tillers (10.60) and grains panicle-1 (136.9) over BRRI dhan29. BRRI dhan58 produced higher grain yield (8.92 t ha-1) compared to BRRI dhan29 (7.27 t ha-1). All the studied parameters differed significantly with the application of TSP fertilizer except non-effective tillers hill-1. Application of 112 kg TSP ha-1 produced the highest number of effective tillers hill-1 (12.00) and the lowest in farmers practice (7.20). Fertilizer Recommendation Guide based TSP fertilizer (112 kg ha-1) produced the highest grain yield (8.80 t ha-1) of boro rice and the lowest grain yield (7.40 t ha-1) in farmers’ practice. Results of the study elucidated that TSP application at 112 kg ha-1 was effective to improve the rice productivity.