bluuebunny/crossref_metadata_2025 huggingface dataset:
AUTOMATED SYSTEM FOR CONTINUOUS MICROALGAE CULTIVATION IN PHOTOBIOREACTORS
Authors: D’Agostin D. A. L. , Domene G. M. , Oliveira A. S. , Bonfim M. J. C. , Mariano A. B.
Published: November 2018

The objective of this work was to design a automate system for microalgae cultivation on a continuous modes in laboratory scale and allow its remote monitoring and control. For this, a sensor were developed is able to measure biomass concentration. The concentration sensor used the principle of light scattering, that is, by measuring the turbidity of the culture medium by the use of a set of phototransistor and green led. It presented an mean absolute percentage error of 8.46% during the experiment. A pH, temperature and light sensor were also installed. The control of all the sensors was accomplished by means of an microcontroller. For remote control and monitoring of the controller, a database was designed and implemented on a Raspberry Pi connected to the network. The graphics and data collected are available on an HTML page that allows changes in the control mode of the photobioreactor, for example by changing the dilution rates. The controller was able to operate the photobioreactor in batch mode, as well as to maintain the culture operating in continuous regime. The continuous production of microalgae biomass in a continuous regime showed productivity 74.5% higher than the traditional batch process and 28.2% higher than semicontinuous cultivation.
EDITORIAL
Authors: Vargas J. V. C.
Published: November 2018

The editorial of Engenharia Térmica of this issue continues the discussion on scientific research needs in vital areas in which thermal engineering has important participation. The main goal is to motivate the readers, within their specialties, to identify possible subjects for their future research.In the beginning of the 21st century the international scientific community pointed out that there was a need for increased push towards alternative energy technologies to replace fossil and nuclear sources in the near future, in order to determine what is scientifically possible, environmentally acceptable and technologically promising. Also, the scientists recalled that policy, science and technology need to work together harmoniously, which are responsible for acceptability, possibility and practicability, respectively. A great amount of diversity with the exploration of innovative nanomaterials and their hybrid assemblies for energy conversion and storage have been seen in energy research. Advances in time-resolved spectroscopy, surface science, imaging techniques, and various in situ and operando characterization techniques are providing new insights into energy conversion and storage processes. The same challenges continue to be up-to-date as discussed by the scientific community recently, showing that technically and economically viable renewable energy generation and storage are major hurdles to be overcome. For that, some research areas that need to be pursued in the energy field were listed: energy materials; electrochemical energy conversion and energy storage; solar cells; solar fuels; LED and display devices, and last but not least theory and computational modeling. Such areas represent a few potential opportunities, which in the opinion of Engenharia Térmica have the potential for important scientific advances.The mission of Engenharia Térmica is to document the scientific progress in areas related to thermal engineering (e.g., energy, oil and renewable fuels). We are confident that we will continue to receive articles’ submissions that contribute to the progress of science.
ANALYSIS OF WEIBULL PARAMETERS FOR WIND POWER GENERATION
Authors: Oliveira Filho O. D. Q. de , Araújo A. M. , Borges W. F. A. , Silva A. A. C. , Bezerra C. C. A. , Fernandes E. C. R. , Rocha E. J. F. , Rocha G. J. A. M. , Andrade L. I. , Ribeiro D. G.
Published: November 2018

The aim of the present work is to perform an analysis of both Weibull parameters k and c for wind power generation so that one can have an idea of how the mechanisms of wind energy estimation work and build a better understanding of these parameters. This paper covers aspects from the definition of continuous random variable to the analysis of the scale (c) and shape (k) parameters themselves. Mathematical and physical analysis will be performed and finally, a comparison between the parameters and their influence on wind analysis will be presented.
WAKE CHARACTERIZATION IN ROW ARRAY OF HYDROKINETICS TURBINES
Authors: Britto V. S. , Mendes R. C. F. , Brasil A. C. P. , Oliveira T. F.
Published: November 2018

This study aims to obtain wake information, which passes through a linear array of turbines. Is presented a numerical approach to observe what effect can be obtained from a 2.2 meters turbines set. The linear array parameters were based on the Hydro-k project, in which two unconfined in-line rotors were used. The studies were performed by analyzing three variables: mean normalized velocity, turbulence kinetic energy and turbulence intensity. It was noted that the iteration between the rotors alters the flow on the array of turbines increasing the center speed.
A BRIEF REVIEW ON THE ADVANTAGES, HINDRANCES AND ECONOMIC FEASIBILITY OF STIRLING ENGINES AS A DISTRIBUTED GENERATION SOURCE AND COGENERATION TECHNOLOGY
Authors: Delgado Filho M. A. , F. T. S. Araújo N. M. , Maia F. P. , Medina Tapia G. I.
Published: November 2018

The present paper aims to provide a brief review of the potentiality and economic feasibility of the Stirling engine as a distributed generation source and cogeneration technology. Another objective was the determination of hindrances which may be preventing the feasibility of the Stirling technology. With these intentions, a research based on a combination of preselected keywords was performed at the Metasearch of CAPES (Brazil's Higher Education Coordination of Personnel Perfecting). No filters in relation to the research period or to particular geographical regions were employed, thus publications until 2017’s middle were included and the research was conducted on a global level. Next, the selection of papers which contained some of the keywords was made, consisting initially of the read of the publications’ abstracts. The remaining ones were then further explored and had their relevant information incorporated, according to the scope of this work. It is worth mentioning that other accredited sources which dealt with important aspects of the topic were also included. Furthermore, a table containing some examples of products concerning the application of the Stirling engine as a distributed generation and cogeneration technology is presented. Ultimately, it is concluded that the Stirling technology, despite its advantages and suitability regarding the proposed applications, is not yet commercially feasible, having currently only a minor presence in the market. This scenario can be attributed to the need for further research and technical development as well as cost reduction.
NUMERICAL STUDY OF HEAT TRANSFER IN EXTENDED SURFACESWITH MUTUAL RADIATION BETWEEN PARALLEL FINS
Authors: Sobral R. L. , Quirino J. M. , Correa E. D. , Gama R. M. S.
Published: November 2018

The present work shows the influence of the mutual heat transfer on the effectiveness of finned surfaces. Numerical simulations are carried out through a sequence of linear problems, possessing an equivalent minimum principle, that has as its limit the solution of the original problem. The original nonlinear problem is regarded as the limit (which always exists) of a sequence of linear problems like the classical conduction-convection ones. In this work the nonlinear conduction-radiation heat transfer process is considered and simulated by means of a finite difference linear scheme. Such a limit is reached in an easy way by means of standard procedures, allowing the employment of more realistic hypotheses, like some nonlinear boundary conditions, since the mathematical complexities are not a constraint for simulating the elliptic partial differential equation. This work accounts for the the steady state heat transfer process in rigid fins which experiences convective and radiative heat exchange. Some typical results are shown in order to illustrate the methodology. Results have shown both the relevance of the radiation and the importance of the thermal interaction between the fins, so that there is an effective and realistic thermal mapping. Neglecting the thermal interaction can lead to errors of up to 20 percent.
MODIFIED SERIES RESISTANCE MODEL - DETERMINATION OF MEAN CONCENTRATION BY INTEGRAL TRANSFORMATION
Authors: Venezuela A. L. , Cantão R. F. , Ongaratto R. S. , Haneda R. N.
Published: November 2018

There are several mathematical models that describe permeate flow in membrane separation processes. Among these, the series resistance model plays a prominent role. It takes into account membrane strength, concentration polarization, polarized layer and fouling to describe the permeate flow over time. In this work, an analysis of the modified series resistance model was performed, in which the resistance by polarization of the concentration is defined as being directly proportional to the transmembrane pressure. The proportionality constant is given by the product of a specific coefficient of resistance – which is determined by means of experimental data – the thickness of the boundary layer of concentration and the mean concentration. Due to the inability to obtain experimentally the value of the average concentration within the boundary layer of concentration, its simulation is carried out from the conservation equation of the chemical species. Thus, the objective of the present work was to solve the equation of the conservation of chemical species using GITT (Generalized Integral Transform Technique) and apply the modified series resistance model to describe the permeate flow of a solution of dextran through a permeable tube under laminar flow. GITT provided satisfactory results for the mean concentration, verified by comparison with the permeate flow obtained by the series resistance model with experimental results reported in the literature.
ELETRIC FIELD ENHANCEMENT AND DETERIORATION OF BOILING HEAT TRANSFER AND CRITICAL HEAT FLUX IN DIELECTRIC FLUIDS
Authors: Carrica P. M. , Masson V.
Published: November 2018

We present the results of an experimental study of the effects of externally imposed electric fields on boiling heat transfer and critical heat flux (CHF) in dielectric fluids. The study comprises the analysis of geometries that, under the effects of electric fields, cause the bubbles either to be pushed toward the heater or away from it. A local phase detection probe was used to measure the void fraction and the interfacial impact rate near the heater. It was found that the critical heat flux can be either augmented or reduced with the application of an electric field, depending on the direction of . In addition, the heat transfer can be slightly enhanced or degraded depending on the heat flux. The study of the two-phase flow in nucleate boiling, only for the case of favorable dielectrophoretic forces, reveals that the application of an electric field reduces the bubble detection time and increases the detachment frequency. It also shows that the two-phase flow characteristics of the second film boiling regime resemble more a nucleate boiling regime than a film boiling regime.
SIMULACION NUMERICA DE LA COMBUSTION EN UNA CALDERA A GAS NATURAL UTILIZANDO UN MECANISMO DE REACCION REDUCIDO
Authors: Echaniz Victoria , Brizuela Eduardo
Published: November 2018

En este trabajo se resuelve por el método de los volúmenes finitos, y aplicando un Esquema de Reacción Reducido y conceptos de Eddy Break Up, la combustión de gas natural en aire en una caldera de vapor. Se presentan resultados de la simulación de una llama de difusión turbulenta, en escala natural y condiciones operacionales, con transmisión de calor por conducción/convección y radiación. Por tratarse de una tarea en progreso y de largo alcance que involucra una caldera en servicio los resultados son preliminares y la comparación con resultados experimentales es limitada. No obstante, los resultados obtenidos son considerados satisfactorios, aunque indican que es necesario continuar refinando los modelos de mezclado y radiación para reproducir mejor las condiciones reales.

ABSTRACT
Combustion of natural gas in air in a utility boiler is simulated by means of a finite volume approach, using a Reduced Reaction Scheme and Eddy Break Up concepts. Results are presented for a turbulent diffusion flame, under operational conditions and in full size, including heat transfer by conduction/convection and radiation. Preliminary results only are presented and a limited comparison with experimental results is made due to the scope of the task which involves a facility in service. Nevertheless, results are considered satisfactory, although there are indications that it is necessary to continue refining the mixing and radiation models for better matching with operational conditions.
CONVERSION AND GLOBAL REACTION RATE COEFFICIENT IN THE ABSORPTION OF SO2 BY DIFFERENT TYPES OF LIMESTONE IN A FLUIDIZED BED REACTOR
Authors: Camargo F. L. , Pagliuso J. D. , Milioli F. E.
Published: November 2018

This work concerns the study of the effect of limestone type on SO2 absorption in a bench fluidized bed reactor plant. Conversion and global reaction rate coefficients were established for conditions typical to fluidized bed combustion of coal. The bench plant is a bubbling bed reactor 160 mm internal diameter using silica sand as bed material, fluidized by pre-heated air. In order to simulate conditions close to the fluidized bed coal combustion ambience, the fluidizing air is pre-heated at high temperature (850 oC) and SO2 is added to the fluidizing air in a concentration typical of the process (1000 ppm). All the particulate, i.e. silica sand and limestone particles, was fed to the bed in a narrow size distribution between two subsequent ASTM sieves (with 545 μm mean diameter). In transient batch experiments charges of limestone are quickly injected into the bed, while the consequent variations of the exit concentrations of SO2, CO2 and O2 are continuously recorded. Analysis were performed on the effects of the type of limestone in the process, taking into account possible reaction controlling resistances, and considering possible effects of the calcination on the sulfation process.
FORCED CONVECTION IN DUCTS WITH PERMEABLE WALLS
Authors: Alexandrino C. H. , Martins-Costa M. L.
Published: November 2018

A mixture theory model is employed in a local description of the energy transfer in a duct with permeable wall which is simulated by considering two distinct flow regions, one consisting of a Newtonian incompressible fluid and the other represented by a binary (solid-fluid) mixture. Compatibility conditions at the interface (pure fluid-mixture) for momentum and energy transfer are considered. The simulations are carried out by using a finite difference approach with an upwind strategy for the convective term discretization.
EXPERIMENTAL MEASURES OF THE EFFECTIVE HEAT TRANSFER COEFFICIENTS IN AIR BLAST FREEZERS FOR THE PROCESSING OF FRUIT PULPS
Authors: Resende J. V. , Silveira Junior V. , Neves Filho L.
Published: November 2018

The effective surface heat transfer coefficients during air blast freezing of plastic polyethylene packages containing fruit pulp models conditioned inside multi layer boxes were evaluated under conditions encountered in commercial practice. The results were presented as dimensionless correlations based on hydraulic diameter of the rectangular ducts. The effects on the surface heat transfer coefficient of the air temperature, air velocity, transducer position inside the boxes and box position in the pillage on the surface were analyzed. The results show: the effect of air-cooling temperature on the surface heat transfer is negligible in the range encountered in blast freezing practice. The effective surface heat transfer coefficients predicted by the non-dimensional correlations based on hydraulic diameter was successfully used to represent the bed irregularities, mainly in arrays of 5 and 3 layers. The effective surface heat transfer coefficients varied according to the position between the top and the bottom of the boxes and was influenced by the number of layers in the arrays.
A PRELIMINARY INVESTIGATION INTO THERMAL SPRAY AND OTHER METAL/POLYMER DEPOSITION PROCESSES AND THEIR POTENTIAL USE IN THE OIL INDUSTRY
Authors: Anjos G. V. M. , Sydenstricker T. H. D. , Paredes R. S. C. , Amico S. C.
Published: November 2018

Polymeric coatings are being used in a raising number of applications,
contributing to protection against weather conditions and localized corrosion,
also reducing erosion wear. The coatings may be deposited by various processes
and thermal spray is being recently investigated as a new alternative. This paper
reports an exploratory study into various polymer deposition processes and
evaluates their influence on the quality of the produced coating, concerning
dispersion, cohesiveness and adhesion onto steel substrates. Different content
aluminum/MDPE (medium density polyethylene) mixtures and processing
parameters were studied as an attempt to identify the most promising parameters
regarding their future application to produce coatings for the oil industry. The
material characterization was carried out via mechanical testing (ASTM D638).
The coating adhesion was evaluated by bend and ASTM C633-79 tensile tests. A
microscopy evaluation of the coatings was also carried out. The produced films
showed low friction surfaces and adequate adhesion to steel substrates. The
presence of MAN (maleic anhydride) in the composite was responsible for the
MDPE to recover its ductility, with a small increase of strength and rigidity, as
well as a significant enhancement of coating adhesion to substrate.
CFD STUDIO: AN EDUCATIONAL SOFTWARE FOR CFD ANALYSIS
Authors: Pieritz R. A. , Mendes R. , Ferraz R. , Maliska C. R.
Published: November 2018

The main goal of this paper is to demonstrate the general characteristics of the educational
user-friendly CFD Studio package for CFD teaching. The package was designed for
teaching 2D fluid mechanics and heat transfer process, including conduction, coupled
conduction/convection, natural and forced convection, external and internal flows, among
other phenomena. The finite volume methodology and its related topics can also be taught
using the software. Therefore, general aspects of the three main modules, pre-processor,
solver and post-processor are discussed aiming to show the generality of the tool. These
modules are integrated in the application by a so-called numerical problem project
which guide the student through the steps to obtain the solution. To approximate the
partial differential equations the finite volume approach is employed using a fully-implicit
formulation with the interpolation schemes CDS, UDS and WUDS. Mesh editing and nonorthogonal
boundary-fitted mesh generation, using algebraic interpolation and elliptic
equations, are important features of the package. Coupled heat transfer problems are
handled using the solid-block formulation and the pressure-velocity coupling uses the
SIMPLE and SIMPLEC methods with non-staggered grids. To demonstrate the
capabilities two fluid flow and heat transfer problem projects are presented.
MACROSCOPIC TURBULENCE MODEL ADJUSTMENT FOR A POROUS MEDIUM MODELED AS AN INFINITE ARRAY OF TRANSVERSALLY-DISPLACED ELLIPTIC RODS
Authors: Pedras M. H. J. , De Lemos M. J. S.
Published: November 2018

Through the volumetric averaging of the microscopic transport equations for the turbulent
kinetic energy, k, and its dissipation rate, , a macroscopic model was proposed for flow in
porous media (Pedras and de Lemos, IJHMT 44 (6) 2001). As an outcome of the volume
averaging process, additional terms appeared in the equations for k and . These terms
were here adjusted assuming the porous structure to be modeled as an infinity array of
transversal elliptic rods. Such an adjustment was obtained by numerically solving the
microscopic flow governing equations, using a low and high Reynolds formulation, in the
periodic cell composing the infinite medium. Different porosity and aspect ratios were
investigated. The adjusted model was compared against others types of rods found in the
literature, showing similar results.
INCORPORATION OF A TWO-FLUX MODEL FOR RADIATIVE HEAT TRANSFER IN A COMPREHENSIVE FLUIDIZED BED SIMULATOR PART II: NUMERICAL RESULTS AND ASSESSMENT
Authors: Rabi J. A. , De Souza-Santos M. L.
Published: November 2018

As shown in the first part of this paper, equations and considerations for a preliminary
attempt to improve the treatment for radiative heat transfer of a previous comprehensive
simulation program were presented. For that, the two-flux radiative heat transfer model
was applied. In this second part, the new version of that program was tested against
steady-state operations of real equipment. Numerical simulations were carried for two
different fluidized-bed reactors: a coal-fed boiler and a wood-fed gasifier.
Computational results obtained with that new version were compared with those
obtained with the previous simulator version. Then, both sets of results were also
compared with real operational data. Special attention was paid to the temperature
profiles of each particle species present in the bed section  carbonaceous, limestone and
inert  as well as to the radiative heat transfer rates between these solids. Effects on the
temperature profiles of the gas phases  emulsion and bubbles  and on the equipment
performance parameters were also investigated. Improvements related to the
incorporation of two-flux model are assessed and discussed. New developments and
extensions of this approach are indicated.
SURGERY BY INFRARED VISION
Authors: Brioschi M. L. , Malafaia O. , Costa A. F. C. B. , Vargas J. V.
Published: November 2018

This paper is about the development, uses and advantages of infrared
thermography. Its principles had already been used by old civilizations as a
manner of diseases diagnosis. The discovery of the infrared waves and its
heating power happened on 1800, but its use in modern Medicine as a
diagnosis method was only possible because of the scientific and
technological development demanded by the Great Wars, in the 20th
century. Here the authors present some news and promising surgery
applications.
FLOW AROUND MODIFIED CIRCULAR CILYNDERS
Authors: Ferreira R. L. , Vieira E. D. R.
Published: November 2018

The flow around a circular cylinder has awaken the attention of different
researchers since the historic Strouhal's work of 1878. Ever since, many
experimental and numeric works have been carried out in order to
determine the relationship between the vortex shedding frequency and the
flow regime. Recently, a number of studies have been developed using
several small modifications in circular cylinder. In this work a circular
cylinder modified with a longitudinal concave notch, has been tested in
order to determine the relationship between the non-dimensional vortex
shedding frequency (Strouhal number) and the Reynolds number has been
determined to Reynolds up to 600. Additionally a modified circular
cylinder with a longitudinal slit also has been tested in order to determine
the Strouhal-Reynolds relationship in several attack angle configurations.
The experiments have been carried out in a vertical low turbulence
hydrodynamic tunnel with 146x146x500 mm of test section operating in
continuous mode. Flow visualization by direct liquid dye injection has been
utilized in order to produce vortex images. These images have been
captured in still chemical photography for different Reynolds numbers. A
hot-film probe has been adequately positioned in the vortex wake to
determine the vortex shedding frequency and consequently the Strouhal
number.
COMPARATIVE ANALYSIS OF THE IAPWS-IF97 FORMULATION PERFORMANCE FOR THERMODYNAMIC PROPERTIES OF WATER ON A RANKINE CYCLE
Authors: Fonseca Jr. J. G. , Schneider P. S.
Published: November 2018

The present paper presents the computational implementation of the industrial
formulation of the thermodynamic properties of water at liquid and
steam phases, proposed by the International Association for the Properties
of Water and Steam, known as IAPWS-IF97. The validity field extends over
to temperatures T between 0ºC and 800°C, for pressures p up to 100 MPa.
Temperature T, specific volume v, specific enthalpy h, specific entropy s,
specific heat at constant pressure cp and constant volume cv, besides saturation
pressure ps, are calculated having a pair of known input values (p,T),
(p,h) or (p,s). A comparative analysis between the IAPWS-IF97 routines
and others, based on foregoing propositions, from an application on Rankine
cycle, is made. IAPWS-IF97 has proved to be more precise, mainly because
it accounts for the region of compressed liquid, besides requiring less processing
time. The development is carried out as FORTRAN90 subroutines
and functions and is available for public use according to a General Public
License.
NUMERICAL MODELING OF THE PLANETARY BOUNDARY LAYER
Authors: Oliveira P. , Soares J. , Karam H. A. , Pereira M. M. R. , Marques Filho E. P.
Published: November 2018

This work describes the major available techniques to simulate the time and
space evolution of the planetary boundary layer. For homogeneous and
equilibrium conditions the structure of the planetary boundary layer can be
diagnosed from the Monin-Obukhov, Free Convection, Local and Mixed
Layer Similarity theories. For the other atmospheric conditions the
planetary boundary layer can be numerically simulated using first and
second order closure models and large eddy models. The closure models
take into consideration the traditional statistical approach. Large eddy
simulation models are based on the filtered equations of motion and require
the statistical approach to estimate subgrid turbulence.
THE APPLICATION OF THE BOUNDARY ELEMENT METHOD TO SOLVE VISCOUS FLOW PROBLEMS BASED ON PRIMITIVE VARIABLES FORMULATION
Authors: Santos M. F. C. L. , Barbosa J. R. , Carneiro H. F. F. M.
Published: November 2018

The boundary element method is applied to the solution of incompressible
fluid flow problems governed by the continuity and Navier-Stokes
equations. The differential equations are transformed into integral equations.
Indication of the transformation is given in detail. Application to simple flow
cases such as the driven cavity and forward facing step is presented.
Convergence difficulties are indicated, which have limited the applications
to flows of low Reynolds numbers..
EDITORIAL
Authors: Vargas J. V. C.
Published: November 2018

The global economy lives a period of great apprehension regarding energy issues for the near future. The developed countries continue to have a steady growth and the emerging countries increase their rates of economic growth, which causes a continuing increase in global energy demand. In that context, RETERM calls the attention of the readers to the growing need for the search of alternative energy sources to the current oil based global economy. This effort certainly involves focus and work of the energy related scientific community, field in which Thermal Engineering is part of. There are several alternatives currently under consideration. The Department of Energy of the United States of America is currently seriously focused on research and development of alternative energy sources, mainly aiming the independence of external suppliers, such as nuclear energy and the hydrogen economy. Therefore, it is vital to any nation the allocation of financial resources to the development and technological control of new processes that lead to self-sufficiency in energy generation for internal consumption and economic growth. The fuel cell systems will be of critical importance in the possible hydrogen economy scenery for the near future, and they are at the forefront of the emerging technologies for electric power generation for stationary, mobile and portable applications. The high energy conversion efficiencies, extremely low onsite environmental pollution and noise are among their major advantages in comparison to other systems. However, there are major technological and economic hurdles to be overcome prior to their large scale practical implementation. Similarly to nuclear technology, in fuel cell technology it is observed that each research group develops its own know-how independently and with little exchange of information.In this fifth number, we continue to publish the best articles written in English language, presented at the 9th Brazilian Congress of Thermal Engineering and Sciences, ENCIT 2002, held in Caxambu, MG, from October 15th to 18th, 2002, that were selected by the Associate Technical Editors of RETERM, according to the scientific criteria of the journal. The idea is to increase the industrial and scientific impact of the research results presented in the Congress. Additional articles that have been submitted and reviewed in the regular RETERM publication process are also included in the current issue.
Effect of tillage system on the structure of weed infestation of winter wheat
Authors: Woźniak Andrzej
Published: November 2018

The study aimed to evaluate the structure of weed infestation of winter wheat grown in different weeding systems: conventional tillage (CT), reduced tillage (RT), and herbicide treatment (HT). In CT system, shallow ploughing and pre-sow ploughing were conducted after the harvest of the previous crop. In RT system, shallow ploughing was replaced by cultivator tillage, whereas pre-sow ploughing by a tillage set. In HT system, shallow ploughing was replaced by spraying with glyphosate and pre-sow ploughing by cultivator tillage. At the tillering stage (22-23 in BBCH scale), species composition and number of weeds/m2 were determined with the botanical-gravimetric method, whereas at the stage of waxy maturity of wheat (82-83 BBCH) analyses were conducted for species composition as well as density, air-dry weight, and weed distribution in crop levels. The Shannon-Wiener’s diversity index (H’) and degrees of phytosociological constancy (S) of weeds were determined as well. The study showed that more weeds occurred in RT and HT systems than in the CT system and they produced higher biomass in RT than in CT and HT systems. The tillage system affected weed distribution in crop levels. In CT system, the highest weed density was identified in the ground and lower levels, whereas in RT and HT systems in the ground and middle levels. Values of the species diversity index (H’) indicate a similar diversity of weed species composition between weeding systems and more diverse between study years.
The Role of Social Media in Intercultural Adaptation: A Review of the Literature
Authors: Alamri Basim
Published: November 2018

As international students, sojourners, and immigrants arrive at host cultures, they usually employ certain means and strategies to adjust to the traditions and norms in these cultures. The present article provides a review of the literature about the impact that social networking sites (SNSs), as one of these strategies, have on the process of intercultural adaptation. The article also points out the definitions and several types of SNSs and a number of common models of intercultural adaptation. The literature shows that SNSs have been used for several purposes during the intercultural adaptation process such as: (1) to remain in contact with their family members and friends in their home countries, (2) to obtain social capital, and (3) to socially adjust in educational settings. The pedagogical implications derived from the literature are manifested in threefold: connections and relationships, community, and acculturation.
Factors Influencing Coffee Farmers’ Decisions to Join Cooperatives
Authors: Balgah Roland Azibo
Published: November 2018

The role of cooperatives in buffering the effects of imperfect markets on smallholder agriculture especially in developing countries has been widely atoned. However, and in spite of eminent advantages, not all smallholder farmers join cooperatives. We use empirical data from coffee farmers in Northwestern Cameroon to identify key factors driving coffee farmers’ decisions to join or not to join a cooperative. Using a standardized questionnaire, data was collected from 140 randomly selected farmers (members and non-members) in contact with North West Cooperative Association Limited (NWCA). Data collection took place in January 2018, with 2017 as the reference period. We use the data to characterize the coffee sector in the region, and to identify key drivers for cooperative membership. 41.4% and 58.6% were NWCA members and nonmembers respectively. The area of land under coffee cultivation, dominant income source, household size, experience in coffee farming, and timely payment of farmers’ dues by the cooperative were the key factors influencing coffee farmers’ decision to join the cooperative or not (P=0.05). Identifying such drivers from farmers’ perspectives and informing policy decisions can increase competitive advantage of smallholder farmers and reduce the effects of market imperfection, as embedded in cooperative concept. This should render the concept once more attractive and portray it as a rational option to many smallholder farmers.
DZIAŁANIA NA RZECZ REDUKCJI EMISJI GAZÓW CIEPLARNIANYCH W WOJEWÓDZTWIE LUBUSKIM W LATACH 2010-2015
Authors: SŁOBODZIAN-KSENICZ ORYNA , Jasiewicz Marzena , Polus Dominik
Published: November 2018

W artykule przedstawiono wyniki analizy przeprowadzonej metodą desk research źródeł finansowania przedsięwzięć w obszarze ochrony powie-trza I redukcji emisji GHG w latach 2010-2015 w województwie lubuskim. WFOŚiGW oraz LRPO są wiodącymi instytucjami finansującymi główne inwestycje oraz realizującymi zadania w obszarze ochrony powietrza i redukcji emisji GHG. Efektem realizacji inwestycji jest coraz większy udział energii z OZE oraz obniżanie emisji zanieczyszczeń po-wstających w procesach, które generują największe ilości GHG i ich prekursorów.
WPŁYW SKŁADU GATUNKOWEGO DRZEWOSTANÓW NA CECHY JAKOŚCIOWE PRÓCHNICY GLEBOWEJ TWORZĄCEJ SIĘ NA ZREKULTYWOWANYM WYROBISKU POPIASKOWYM
Authors: Woś Bartłomiej , Pietrzykowski Marcin , Pająk Marek
Published: November 2018

W pracy omówiono wpływ składu gatunkowego drzewostanów na cechy jakościowe próchnicy glebowej tworzącej się na zrekultywowanym i zalesionym wyrobisku popiaskowym KP Szczakowa. Skład frakcyjny i właściwości optyczne badano na próbkach pobranych z wierzchnich poziomów inicjalnych gleb (0-5 cm) w litych drzewostanach: sosny zwyczajnej, modrzewia europejskiego, brzozy brodawkowatej i olszy czarnej. Badane próchnice charakteryzowały się przewagą węgla kwasów fulwowych (CKf) w stosunku do węgla kwasów huminowych (CKh) w składzie frakcyjnym puli węgla związanego (Cog) oraz stosunkowo niskim stosunkiem ekstynkcji kwasów huminowych (E465/E665). Czynnik gatunku zadziałał na właściwości próchnicy glebowej najsilniej w przypadku olszy czarnej. Gleby pod olszą charakteryzowały się większą zawartością węgla organicznego ogółem (Corg) i węgla związanego z kwasami huminowymi i fulwowymi (CKh+CKf) w porównaniu do pozostałych gatunków drzew. Potwierdza to duże zdolności fitomelioracyjne i przydatność do rekultywacji olszy czarnej.
Komitet Białoruski w Generalnym Gubernatorstwie (1940–1945)
Authors: Grzybowski Jerzy
Published: November 2018

The subject of this study is the activity of the Belarusians in the General
Government in 1940–1945. Belarusians were the fifth largest ethnic group in the
GG. The German occupation authorities, applying the principle of “divide and conquer”, were ready to give Belarusians some freedom in the sphere of culture,
religion and economy. In 1940, the Belarusian Committee was established in
Warsaw, with branches in Biała Podlaska and Kraków. The majority of committee
members were Belarusians and Poles – prisoners of war and refugees from the
Soviet occupation zone of Poland. As a priority of this organization, cultural,
educational and religious activities among the Belarusians in the General
Government were recognized. The activists of the committee managed to create
a school in Warsaw and two parishes (Orthodox and Catholic). Belarusian
activities faced some difficulties. Serious problems for the Belarusians Committee
caused the activities of Ukrainian organizations in the GG. One of the episodes
in the history of the Belarusian Committee is the cooperation of its activists with
German military intelligence.
Hacia una definición latinoamericana de Responsabilidad Social Universitaria. Aproximación a las preferencias conceptuales de los universitarios
Authors: Vallaeys François , Álvarez Rodríguez Juliana
Published: November 2018

La Responsabilidad Social Universitaria (RSU) es una nueva política de gestión universitaria que redefine la tradicional extensión y proyección social solidaria, introduciendo un enfoque global de cuidado de los impactos administrativos y académicos en todos los procesos de la universidad. Exige ser asumida por todos los miembros de la universidad transversalmente en sus actividades, siendo imprescindible que ellos entiendan de qué se trata y estén dispuestos a la corresponsabilidad en sus funciones laborales rutinarias. Este estudio busca responder a la pregunta: ¿Cuánto han avanzado los universitarios latinoamericanos en la comprensión de este nuevo paradigma? La investigación es de corte cuantitativo, exploratorio y muestreo por conveniencia a través de una encuesta aplicada a 740 actores universitarios (alumnos, profesores, administrativos y directivos) de 17 universidades en siete países latinoamericanos, donde se analiza cómo los actores universitarios conciben la RSU, seleccionando una de cinco definiciones propuestas. Los resultados marcan varias tendencias: primero, el enfoque estrictamente asistencial ha disminuido de la mente de los universitarios; segundo, las preferencias apuntan a la perspectiva de participación en el desarrollo local, regional y nacional junto con otros actores del entorno y al enfoque de la guía ISO 26000, que define la responsabilidad social como gestión de los impactos organizacionales. Se concluye que este concepto de gestión de impactos ha empezado a penetrar en la mente de la comunidad universitaria, y que se está superando la visión reductora del compromiso social universitario asumido solamente desde la extensión voluntaria, fuera de la formación curricular y la investigación. Se Propone construir una definición latinoamericana de RSU basada en la participación en el desarrollo territorial y la gestión de impactos administrativos y académicos.
La formación inicial del profesorado de Educación Secundaria en España: perfil y motivaciones del futuro docente
Authors: Muñoz-Fernández Guzmán Antonio , Rodríguez-Gutiérrez Pablo , Luque-Vílchez Mercedes
Published: November 2018

La formación inicial del profesorado es un elemento clave para la mejora de la calidad educativa. En este contexto, la necesidad de mejorar las competencias y destrezas del nuevo profesorado, y en concreto, las motivaciones que llevan al futuro docente a la elección del Máster de Formación en Profesorado de Secundaria gozan de una especial relevancia.La importancia de conocer dichas motivaciones reside en su potencial como predictor del desempeño futuro en la docencia. De manera incipiente, la literatura señala la necesidad de estudiar el perfil motivacional en el desarrollo profesional de los docentes. Sin embargo, consideramos que hasta el momento ha sido escasa la atención prestada. En este sentido, el presente trabajo tiene como objetivo profundizar en el análisis del perfil motivacional del alumnado del máster de formación del profesorado. Para ello, se ha realizado una encuesta a 512 alumnas y alumnos de diferentes especialidades, en tres universidades españolas (Burgos, Córdoba y Jaén), que respondieron a un cuestionario sobre motivaciones y vocación hacia la docencia. Se ha aplicado un análisis factorial para simplificar y conocer sus principales motivaciones y un análisis clúster para clasificar al alumnado según sus factores motivacionales principales. Los datos revelan que existe relación negativa entre la motivación intrínseca hacia la docencia y la edad del encuestado. También se ha encontrado que el alumnado de áreas de conocimiento relacionadas con las Artes y las Humanidades presenta un mayor nivel de motivación docente intrínseca; y, por otra parte, el hecho de tener un posgrado anterior se relaciona con una menor vocación.Comprender las motivaciones para ser docente, puede tener interés tanto para las autoridades educativas encargadas de la selección del alumnado como para aquellas que tengan la potestad en la planificación de la formación del profesorado, desde el punto de vista del diseño curricular.
Claves de acción socioeducativa para promover la participación de las familias en procesos de acogimiento
Authors: Balsells Bailon M. Ángels , Urrea Monclús Aida , Ponce Alifonso Carmen , Vaquero Tió Eduard , Navajas Hurtado Alicia
Published: November 2018

El enfoque de la parentalidad positiva está contribuyendo a cambiar el modelo de intervención en el Sistema de Protección a la Infancia y a la Adolescencia. Desde este enfoque, la participación de la familia biológica se contempla como un elemento esencial que facilita la vuelta a casa de los hijos, promueve la implicación de los padres y ayuda a incrementar su conciencia sobre los motivos reales de la separación. El artículo muestra los resultados de un estudio llevado a cabo en España cuyo objetivo fue analizar la participación de la familia en el momento en el que comienza la medida de acogimiento, ya que esta conforma una fase fundamental en la intervención. Para ello, se ha realizado una investigación cualitativa utilizando grupos de discusión y entrevistas semi-estructuradas con 135 participantes: 63 profesionales del Sistema de Protección, 30 niños y adolescentes involucrados en procesos de acogimiento y reunificación y 42 padres de estos jóvenes. Los resultados profundizan en ciertos ámbitos relacionados con la información que las familias reciben, así como en su implicación y participación en el proceso. Entre los hallazgos, se resalta la sensación de vacío informacional de los padres en cuanto a los aspectos legales y las características del recurso de acogida, así como las escasas oportunidades que se les ofrecen para implicarse en la toma de decisiones. Al respecto, se proponen acciones socioeducativas encaminadas a optimizar la práctica profesional e involucrar a las familias en la mejora del ejercicio de su parentalidad.
Le comportement électoral des Québécoises
Authors: Warren Jean-Philippe , Mongeon Philippe
Published: November 2018

Si quelques analyses ont porté sur le vote féminin dans la période plus récente, la période qui va de 1950 à 1976 reste encore en grande partie inexplorée et, par conséquent, on ne connaît pas grand-chose sur le vote des femmes francophones au provincial dans le Québec de l’après-guerre et de la Révolution tranquille. La présente note de recherche offre des pistes d’analyse du vote féminin québécois dans les années 1950 et 1960. En premier lieu, nous cherchons à saisir dans quelle mesure les femmes étaient alors prêtes à assumer le rôle attendu de citoyennes qu’elles avaient déjà commencé à apprivoiser au fédéral depuis 1918. En deuxième lieu, nous tentons d’établir les préférences partisanes des électrices par rapport aux électeurs.
Du « savoir » à la « compétence »
Authors: Gulian Thomas
Published: November 2018

Cet article a pour objectif de proposer quelques pistes de réflexion aux jeunes docteur·e·s en science politique pour faciliter leur transition professionnelle entre le monde universitaire et le marché du travail extra-universitaire. Identifiant certains acquis essentiels de la formation doctorale, l’auteur montre en quoi ils constituent des atouts pour des organisations extra-universitaires. Si les jeunes docteur·e·s peuvent éprouver des difficultés à réaliser leur transition professionnelle vers le marché du travail non universitaire, cela s’explique par le fait que ce dernier est fondé sur le paradigme de la « compétence », tandis que l’université reconnaît plutôt celui de « savoir ». L’article se termine sur quelques conseils pour faciliter ce passage d’un paradigme à un autre.
Control in Subsidiary Networks in Asia: Toward an Extension of the Centralisation-Formalisation-Socialisation (CFS) Model
Authors: Amann Bruno , Jaussaud Jacques , Schaaper Johannes
Published: November 2018

Prior research establishes that international control by multinational corporations is based on three dimensions: centralisation, formalisation and socialisation. New control mechanisms appeared in the last decade, such as enterprise resource planning, short-term assignments and regional centres. Do these new mechanisms fit the three control dimensions? How do MNCs articulate their control mechanisms, including new ones? Using interviews with 77 managers of 47 French MNCs in 11 Asian countries, this study presents an exploratory factor analysis and clustering. The findings show that French MNCs control their Asian subsidiaries through four dimensions: centralisation of decision making, formalisation of subsidiaries, socialisation and expatriation.
El discurso galleguista del centro y la derecha entre la Transición a la democracia y la consolidación autonómica (1975–1985)
Authors: Prada Rodríguez Julio
Published: November 2018

Este artículo aborda el proceso de elaboración y la praxis del discurso galleguista de las formaciones de centro y derecha estatales y de sus herederas desde la muerte de Franco hasta las segundas elecciones autonómicas de Galicia. Se analiza en qué medida la dimensión regionalista de este discurso contribuyó al reforzamiento de una identidad propia compatible o tensionada con el Estado-nación. Se estudia, asimismo, la influencia que su implementación y las políticas a él asociadas pudieron tener a la hora de bloquear la consolidación de una fuerza de signo nacionalista de centro-derecha.
Temperature as a Causative Factor in Diabetic Foot Ulcers: A Call to Revisit Ulceration Pathomechanics
Authors: Yavuz Metin , Ersen Ali , Hartos Jessica , Lavery Lawrence A. , Wukich Dane K. , Hirschman Gordon B. , Armstrong David G. , Quiben Myla U. , Adams Linda S.
Published: November 2018

Background:

Diabetic foot ulcers (DFUs) are a major burden to patients and to the health-care systems of many countries. To prevent or treat ulcers more effectively, predictive biomarkers are needed. We examined temperature as a biomarker and as a causative factor in ulcer development.

Methods:

Thirty-seven individuals with diabetes were enrolled in this observational case-control study: nine with diabetic neuropathy and ulcer history (DFU), 14 with diabetic neuropathy (DN), and 14 nonneuropathic control participants (DC). Resting barefoot plantar temperatures were recorded using an infrared thermal camera. Mean temperatures were determined in four anatomical regions—hallux and medial, central, and lateral forefoot—and separate linear models with specified contrasts among the DFU, DN, and DC groups were set to reveal mean differences for each foot region while controlling for group characteristics.

Results:

The mean temperature reading in each foot region was higher than 30.0°C in the DFU and DN groups and lower than 30.0°C in the DC group. Mean differences were greatest between the DFU and DC groups, ranging from 3.2°C in the medial forefoot to 4.9°C in the hallux.

Conclusions:

Increased plantar temperatures in individuals with a history of ulcers may include acute temperature increases from plantar stresses, chronic inflammation from prolonged stresses, and impairment in temperature regulation from autonomic neuropathy. Diabetic foot temperatures, particularly in patients with previous ulcers, may easily reach hazard thresholds indicated by previous pressure ulcer studies. The results necessitate further exploration of temperature in the diabetic foot and how it may contribute to ulceration.