bluuebunny/crossref_metadata_2025 huggingface dataset:
Clonal Propagation of Flacourtia indica for Ensuring Quality Planting Materials and Sustainable Supply of Edible Fruits
Authors: Kabir Md. Alamgir , Khan Md. Hasan Mehedi , Rahman Md. Masudur , Alam A.T.M. Rabiul , Jahan S.M. Hemayet , Zaman A.K.M. Mostafa , Mamun Muhammad Zahid Al
Published: July 2017

The present study was carried out at the Agriculture research field, Patuakhali Science And Technology University(PSTU), Patuakhali, from March, 2015 to April, 2016 to explore the domestication potential and to evaluate the rooting performance of Flacourtia indica (katabohori), a wild fruit species in Bangladesh, through clonal propagation by stem cutting under 3 different doses of rooting hormone IBA (Indole Buetaric Acid) and planted in the perforated plastic tray filled with coarse sand and gravel placed in the non-mist propagator. The experiment was laid out following a Randomized Complete Block Design (RCBD) with 4 treatments and 4 replications (blocks). The treatments were T0= control, T1 = 0.2% IBA, T2 = 0.4% IBA, T3 = 0.8% IBA. The rooting ability of cuttings was significantly influenced by the application of IBA. The results showed that the highest rooting percentage (100) and maximum root number (8) of Flacourtia indica stem cuttings were obtained from the cuttings treated with 0.4% IBA followed by 0.2% IBA where as the longest root length (8.998 cm) was recorded with 0.2% IBA followed by 0.4% IBA. Survival percentage of the cutlings (the rooted cuttings) after 3 months of transferring them into poly bags was also significantly enhanced by exogenous rooting hormone (IBA) application. The highest survival percentage (84.5 %) was for the cuttings treated with 0.4% IBA followed by 0.2% IBA (71%). The similar trend was also observed for average cutling height and number of leaf. Findings of the present study reveal that the plant species is highly amenable for clonal propagation by stem cuttings using low-cost non-mist propagator. Considering both rooting percentage and root number, 0.4% IBA treatment of stem cuttings may be recommended for mass production of quality planting stocks for the domestication of the species in homestead agroforestry or in fruit orchards to provide edible fruit to rural poor people of natural disaster vulnerable Bangladesh.
Nutritional Value of Putak: Apparent Metabolisable Energy, and Growth Performance
Authors: Nalle Catootjie L. , Yowi Marlin R.K. , Tulle Defrys R.
Published: July 2017

Two experiments were conducted to evaluate nutritional value of putak for broilers. Experiment 1. The apparent metabolisable energy of raw and fermented putak were determined. The experimental design used was completely randomized design with three treatments and four replicates. Total of 64 broilers were randomly distributed to 16 pens. A maize-soybean meal basal diet was formulated and three assay diets were then developed by substituting putak (raw, and fermented, 250 g kg-1, w/w), and maize (500 g kg-1, w/w) of the basal diet. Even though the AME and AMEn values of fermented putak were comparable to that of raw putak and maize, but it was slightly higher than that of raw putak. Experiment 2. Using the AME value of raw putak obtained in Experiment 1, five treatment diets containing 0 to 200 g kg-1 putak were formulated. The body weight gain of broilers fed 150 - 200 g kg-1-1 putak was higher to that of control diet, but it was similar to those fed 50-100 g kg-1 putak. No differences were found in FCR and mortality rate. Feed intake of broilers fed diets containing putak was higher than that of control diet. In conclusion, the AME and AMEn values of putak, fermented putak, and maize were comparable. Putak can be included in broiler diets up to 200 g kg-1 without detrimental effects.
Tumbre: análisis del material lítico
Authors: Pereyea Frank
Published: July 2017

Novecientos cuarenta y cinco artefactos de piedra han sido recolectados en Tumbre 2 en las dos expediciones de octubre y noviembre 1976. Estos artefactos pueden dividirse en cuatro categorías:1. Desechos (D): Fragmentos de lascas o láminas con menos de 2 cm.2. Lascas sin retoque: Lascas, láminas o fragmentos de éstos sin retoque.3. Lascas con retoque: Lascas, láminas o fragmentos de éstos que tienen retoque en los bordes.4. Núcleos: Pedazos de materia prima de los cuales se sacaron lascas o láminas con retoque o sin retoque.
Los chichas, los lipes y un posible enclave de la cultura de San Pedro de Atacama en la Puna limítrofe argentino-boliviana
Authors: Fernández Jorge
Published: July 2017

El magnífico adelanto verificado en el conocimiento arqueológico de la región norte de Chile durante el último decenio, contrasta con la parvedad de información referida a las regiones vecinas, especialmente el sur boliviano y al extremo noroeste argentino. Por este motivo, muchos de los beneficios emergentes de aquellos progresos no pueden ser extendidos a la zona considerada, la que tradicionalmente ha sido asignada al dominio de los aborígenes chichas, lipes y atacamas en momentos coincidentes con la conquista hispánica, de lo que existen comprobaciones escritas. No obstante, las dificultades han sido enormes cada vez que los estudiosos han intentado establecer la modalidad, los momentos y el grado de interpenetración que cada una de esas etnias históricas ha efectuado sobre sus vecinas del territorio actualmente argentino, en particular casabindos, cochinocas, humahuacas, apatamas, churumatas, tomatas, etc. Coadyuva al mantenimiento de esta oscura situación la circunstancia de no existir clase alguna de estudios etnohistóricos referentes a chichas y a lipes –poco más que nombres vacuos, al igual que los antes enunciados–, y al casi absoluto desconocimiento en que permanece la arqueología del sur boliviano en algunos sectores parejamente compartido por la del extremo norte argentino. Los avances de la arqueología boliviana no han sobrepasado el departamento de Cochabamba y, en cuanto a la argentina, hasta ahora no ha procurado interpenetrarla de alguna forma.
Investigation of external and internal shock in the stability of Indonesia’s financial system
Authors: Vinus Maulina , Kusairi Suhal
Published: July 2017

The objective of this research is to develop a financial system stability index and analyze the internal and external factors that we expect to affect the stability of the Indonesian financial system. We measured the single model of financial system stability index (FSSI) from year 2004M03 to2014M09 in Indonesia, and compiled a single quantitative measure based on aggregate internal factors and external factors to capture and predict the shocks of the financial system stability. Stability parameters were composed of composite indicators on different bases. In addition, we developed a comprehensive index component associated with the relevant market conditions, including banking soundness index, financial vulnerability index, and regional economic climate index. Results stated that US economic growth and economic growth of ASEAN countries positively affected financial stability. In addition, current account, exchange rate, inflation, interest rate were shown to negatively affect financial stability. The results of this study imply that internal factors have a strong influence on the financial stability. Therefore, the central bank should give a fast and correct response to the changes of external and internal financial environment, especially for internal factors through monetary policy.
Risk management and internal audit: Evidence from Greece
Authors: Drogalas George , Siopi Stiliani
Published: July 2017

Risk management is ranked by financial executives as one of their most important objectives. For this reason, a wide range of literature on risk management has been developed. Within this fluid business environment, internal audit plays a key role in monitoring a company’s risk profile and identifying areas for improving risk management processes. The purpose of this study is to provide a comprehensive overview of the factors that impact on risk management regarding internal audit function. Empirical evidence was collected by means of a mailed survey. Regression analysis is used in order to illustrate the information gathered. Consistent with theory and our expectations, the results indicate that internal audit, internal auditor and added value of internal audit are statistically significantly associated with risk management.
Fuzzy Logic Application of Steady-state Harmonic Distortion Limits for the Time-varying Harmonics
Authors: J.H. Han  , G. Jang
Published: July 2017

Harmonic distortion limits recommended by most
international standards are designed for the steady-state
harmonics, which are typically calculated for planning purpose.
A problem can occur, however, when the limits are applied to
actual time-varying harmonics. This paper proposes a new
fuzzy logic application to apply modified steady-state harmonic
limits using total demand distortion, which is recommended in
the IEEE standard 519-1992, to the actual measured harmonic
distortions which varies with time. Fuzzy logic application can
provide simple and easy implementation and reflect experts’
knowledge. The result of fuzzy logic application indicates how
close the current waveform is to a pure sinusoidal wave shape
and also reveals whether this current harmonic distortion is
within or outside the allowable limits. It is expected that this
application can contribute for future developments of
harmonics monitoring, evaluation, and mitigation strategies in
the actual operating status of power system.
The effect of inrush transients on PV inverter’s grid impedance measurement based on inter-harmonic injection
Authors: V. Ćuk  , S. Bhattacharyya  , J.F.G. Cobben  , W.L. Kling  , R.B. Timens  , F.B.J. Leferink
Published: July 2017

This paper addresses a cause for false tripping of
photovoltaic inverters with anti-islanding protection based on
impedance measurement with inter-harmonic injection. Earlier
discussions about tripping problems happening when several
devices are doing the measurement at the same time are
supplemented with a problem caused by inrush transients of
nearby devices.
A series of experiments was conducted in the Power Quality
laboratory of the TU/e, on a PV inverter which complies with
the DIN VDE 0126 standard. Impedance measurement was
done in parallel with the inverter and measurement results are
presented. A criterion for false tripping caused by transients is
explored. Also, influences of network impedance and grid
harmonic pollution on false tripping were analyzed. In the end,
some signal processing techniques are proposed to avoid this
problem.
Powering for Long Term Monitoring in the Enclosed Areas
Authors: A. Boura  , M. Husak
Published: July 2017

Paper presents possible solution and practical
examples for wireless powering and signal transfer using the
inductive coupling. It can be suitable for long term monitoring
in enclosed areas and systems that are isolated form the
surroundings. This solution allows avoiding the batteries. It can
be used for probes bricked in to the wall, extreme temperature
environment measurement, the barrels internal shells health
monitoring etc. Main advantage of this kind of powering is
nearly unlimited lifetime, no toxic pollutions (such as Cd, Li,
H2SO4,… contained in the batteries) and universal applicability.
The powering is provided by the near magnetic field. The
resonance is considered in the design for increasing the voltage
transfer. Also the passive signal transfer can be performed using
this principle while it is similar to the RFID systems (Radio
Frequency Identification). The main contribution of this paper
is prediction of the powering potentialities and distance limits
of this strategy. Voltage levels, power transfer efficiency and
signal modulation effects are studied up to distance of 30 cm.
The simple coils are considered. Also special converter
principle is presented for this purpose.
Improvement of a MPPT Algorithm for PV Systems and Its Experimental Validation
Authors: A.J. Mahdi  , W.H. Tang  , Q.H. Wu
Published: July 2017

The amount of power generated from a
photovoltaic (PV) system mainly depends on the following
factors, such as temperatures and solar irradiances. According
to the high cost and low efficiency of a PV system, it should
be operated at the maximum power point (MPP) which changes
with solar irradiances or load variations. This paper presents an
improved maximum power point tracking (MPPT) algorithm of
a PV system under real climatic conditions. The proposed MPPT
is based on the perturbation and observation (P&O) strategy
and the variable step method that control the load voltage to
ensure optimal operating points of a PV system. The proposed
MPPT algorithm has been implemented by a dSPACE DSP
controller. The experimental results show that the PV power
system, using the proposed MPPT algorithm, is able to accurately
track maximum power points (with minimum steady-state power
oscillations) under rapid irradiance variations.
Maximum power injection acceptance in a residential area
Authors: C. Debruyne  , J. Desmet  , J. Vanalme  , B. Verhelst  , G. Vanalme  , L. Vandevelde
Published: July 2017

The number of installed distributed generation
(DG) in residential areas rapidly increases, specifically in the
form of photovoltaics (PV), causing some undesired side effects
such as voltage rise. Overvoltage can damage critical loads, but
is also disadvantageous for the owner because inverters switch
off in case of overvoltage, resulting in output loss. Voltage
limits are investigated through calculation and simulation of the
voltage profile in a typical low voltage (LV) grid by using load
data. Insolation data is used for the particular case of PV. This
paper presents practical guidelines for the maximum power
acceptance in a residential distribution network and the
estimation of PV production loss due to overvoltage.
A Dynamic Model of an Absorption Chiller for Air Conditioning
Authors: S. Bittanti  , A. De Marco  , M. Giannatempo  , V. Prandoni
Published: July 2017

In this paper we study the absorption chiller with
a water/lithium bromide solution. Its dynamic behaviour is
described by means of constitutive correlationships and
conservation equations. We will work out a detailed model
linking the plant dynamic behaviour to the various phenomena
and their interactions.
The model is implemented using Simulink libraries that interact
with several S-functions written in the C programming
language.
Operational properties of a photovoltaic system with three single phase inverters
Authors: S. Seme  , G. Štumberger  , J. Voršič
Published: July 2017

In the recent years the number of photovoltaic
systems which are connected to the distribution networks is
increasing all over the world. It is to expect further increase in
the future. This work focuses on analysis of a photovoltaic
system with three single-phase inverters connected to the
electric grid. Photovoltaic systems often use single-phase
inverters. The disadvantage of such systems is asymmetrical
unbalanced delivery of electricity to the distribution network.
This means that the currents in individual lines are unbalanced
which leads to the unbalanced three-phase power generation.
Fully Automated MV Cable Monitoring and Measurement System for Multi-Sample Acquisition of Artificial Aging Parameters
Authors: C. Freitag  , M. Mladenovic  , C. Weindl
Published: July 2017

The Power quality of our networks is influenced
by transients, short- and long-duration variations, voltage
unbalance, waveform distortions, voltage fluctuations and
power frequency variations. These impacts affect the aging
rapidity of the electrical equipment and finally the entire
electrical network. By partial discharge (PD) and tan(δ)
analyses, it is possible to determine the electrical equipment’s
condition. The significance of the results depends on the quality
of the measurement system and of the data interpretation. Based
on these results, a reliable maintenance and investment strategy
could be made, and the reliability of the network could be
improved. A specially designed aging system for the
accelerated aging of MV cables has been developed to point out
the most relevant aging parameters and their limits, and, in this
way, to upgrade the accuracy of the MV cable diagnostics. In
this paper, the system’s “intelligence”, which controls the aging
process and acquires, evaluates and stores all necessary data is
presented.
A control system for low-head diversion run-of-river small hydro plants with pressure conduits considering the tailwater level variation
Authors: J.I. Pérez-Díaz  , J. I. Sarasúa  , J. Fraile-Ardanuy  , J.R. Wilhelmi  , J. A. Sánchez
Published: July 2017

This paper presents a control system for low-head
diversion run-of-river small hydro plants with pressure
conduits. Since these hydropower plants usually have low or
null water storage capacity, the water discharged through the
turbines should be adapted to the possible extent to the natural
river inflow. For this purpose, a control scheme aimed at
maintaining a constant water level in the head pond is normally
used in these cases. As an alternative, the option of maintaining
a constant water level in the surge tank is studied in this paper.
Furthermore, since in low-head hydro plants the tailwater level
variation may represent a relatively important contribution to
total head losses, it has been explicitly considered in the
proposed control system. A small-perturbation stability analysis
has been carried out in order to analyze the influence of the
plant design and controller parameters in the plant dynamic
response. Finally, in order to illustrate the applicability of the
proposed control system, several simulations have been carried
out using data gathered from a real hydro plant.
Performance Analysis of a PEM Fuel Cell
Authors: J.I. San Martín  , I. Zamora  , J.J. San Martín  , V. Aperribay  , P. Eguía
Published: July 2017

In this paper, both a theoretical and an
experimental study of the dynamic performance of a
commercial fuel cell are described. The analysis has been
focused in the start up and shutdown processes because they
allow analysing the influence of different parameters. In this
sense, the evolution of the stack and the environment
temperatures can be observed, which allows measuring the heat
released by the fuel cell. Moreover, the analysis of the flow of
hydrogen and air allow obtaining various models for simulating
the fuel cell system. Finally, the graphics associated with the
variation of the stack voltage and current make possible to
obtain the characteristic equations of these fuel cell systems, in
order to provide power for auxiliary devices when the battery is
not operating.
QUALITY OF PELLETS FROM OLIVE GROVE RESIDUAL BIOMASS
Authors: A. García-Marave  , A. F. Ramos-Ridao  , D.P. Ruiz  , M. Zamorano
Published: July 2017

Two of the main environmental problems that man currently
faces are the high rate of waste generation and energy
consumption, both bearing directly upon climate change. The
situation requires a change in waste management models, with a
greater focus on waste reduction, recycling and appraisal, as
well as a change in energy models. This signifies the use of
renewable energy sources to supply part of the future demands
of fossil fuel. Such sources include biomass sources from
agricultural waste. Southern Spain has a large supply of
biomass of a residual nature from agricultural activities, such as
olive pruning. However, the use of pellets made from olive tree
leaves or a mixture of different parts of olive trees is not as yet
widespread. This research shows that the use of different types
of raw materials from olive grove residues results in pellets
with different physical and chemical properties, which define
their possible application. More research is needed to design the
production of pellets, which will have properties suitable for
specific applications and which will possess the quality that
satisfies accepted standards and norms.
Improved Energy Management of Capacitive Energy Storage in Metro Railcar by Simulation
Authors: Istvan Szenasy
Published: July 2017

This paper focuses on the use of modeling
and simulation of a renewable energy. The capacitive
energy storages contribute to the rapid energy recovery
associated with regenerative braking in electric vehicles.
This power system allows the acceleration and
deceleration of the vehicle with a lower loss of energy.
Short-distance passenger traffic on electrified lines is a
domain where brake energy recuperation might reduce
the total energy consumption significantly. In this paper
the results of simulation models by Matlab-Simulink for
an urban-metro railcar and some methods for reducing
the needed value of capacitance by an improved energy
management are presented. The aim of the new
management of the energy storage system for decreasing
the needed value of capacitance and improving the
system performance is presented.
Distributed Energy Resources (DER) Systems Integration into MV and LV Networks - Impact on Power Quality of the System
Authors: J. Stenzel  , E. Vilchez
Published: July 2017

The fast growing of Distributed Generation (DG)
in European electricity networks, lead to challenges of different
nature. Due the fast growth of market split of Distributed
Energy Resources (DER), today’s electric power system of
centrally located generation, transmission networks and
distribution networks is expected to evolve into a new
configuration. The achievement of such drastic transformation
will heavily rely on studies that evaluate the behaviour of
networks with integrated DER systems. In particular, Power
Quality (PQ) has been given significative attention due to the
fact that new power system applications are more and more
sensitive to power quality disturbances.
The aim of this study is to examine the power quality behaviour
of the network in case of integration of DER units at different
locations of the MV and LV system. In order to analyse the
impact of DG on the network's power quality, a 380 kV
transmission system with MV, and LV subsystems, 10 kV and
0.4 kV respectively is used, DER units are integrated and power
quality analyses are performed.
Renewable Energy Integration in Buildings A Case Study in Portugal
Authors: N. Tomás  , A. Carvalho  , D. Coelho
Published: July 2017

This paper aims at the presentation of a proposal
for the integration of solar thermal technology in buildings,
particularised for the Portuguese context through a case study, a
new sport public building in Coimbra, which consists of two
swimming pools, gym, jacuzzi and sanitary facilities. This
proposal has been developed in the framework of a Master
dissertation currently under development, which the main
objective is the selection of the most appropriate technological
solution for the integration of renewable energy in buildings. In
this paper we propose the selection of the most appropriate
technological solution for the integration of three thermal solar
systems in the new building. Two systems are used for heating
the swimming pools and the third one is dedicated to domestic
hot water. The selection of the best solution will take into
account the constructive aspects of the building, the building's
energy needs and the local availability of renewable resources
and market technologies. For each solar thermal system, the
general scheme of the proposed technical solution is presented.
Investment costs and economic viability of the selected
solutions are also presented.
Energy Efficiency in a Municipal Building Case Study: “Casa da Cultura de Coimbra”
Authors: L. Costa  , U. Correia  , D. Coelho  , C. Machado Ferreira
Published: July 2017

The aim of this paper is to present the main
results of an energy audit that has been conducted in a
Portuguese municipal building during 2009. The adopted
methodology for analysis the energy flow in the building for
energy saving and rational use of energy in municipal buildings
can be applied to all municipal buildings. Besides the main
results of energy analysis, the paper presents the identified
energy efficient measures to reduce energy consumption (with
positive impact on the energy bill and greenhouse gas
emissions), while maintaining or improving human comfort,
health and security. The evaluation of measure’s impact is also
presented.
Selected Problems of Optimization of a Switched Reluctance Motor for an Electric Vehicle using Analytical Calculations
Authors: M. Majchrowicz  , W. Jazdzynski
Published: July 2017

A model and an example of optimization of a 6/4
type SRM, designed for an electric vehicle, is described in the
paper. The modelling procedure, based on simplified analytical
calculations, allows for estimation of the torque, efficiency and
acoustic noise of the motor, taking into account the magnetic
non-linearity. Some problems arising from the existence of
mutual inductances are described as well. Calculations have
been performed in MATLAB environment, and verified by
means of FEM analysis.
Optimal location of a biomass power plant in the province of Granada analyzed by multi-criteria evaluation using appropriate Geographic Information System according to the Analytic Hierarchy Process
Authors: M. A. Herrera-Seara  , F. Aznar Dols  , M. Zamorano  , E. Alameda-Hernández
Published: July 2017

Nowadays renewable energies are in a period of
growth, which favours the birth of numerous researches like, for
example, this study about the analysis of the optimal location of
a biomass power plant in the province of Granada (Spain).
So, the study will be developed using Geographic Information
System (GIS) and Multi-Criteria Evaluation (MCE) according
to the Analytic Hierarchy Process (AHP). And the main target
will be to determine the welcome capacity of the territory to this
type of plants.
Power Quality Improvements for an Electrical System with an Automobile Shredder
Authors: James R. Johnson  , Remi Bolduc  , Jean-Marc Lupin  , Laurent Chenevard
Published: July 2017

The quality of the power supplied by utilities today is
effectively defined in the harmonic standards adopted
by many countries or by local utility codes. This is
primarily due to user demands for quality power so
that user power interruptions are minimized.
Presented are numerous possible solutions to
address flicker and a case study for an automobile
shredder from the planning stages through
measurements after installation. The solution chosen
for this application will be discussed and presented.
Index terms: Active harmonic filter, hybrid VAR
compensator, hybrid VAR compensation, flicker,
power quality, total harmonic voltage distortion [THDv],
VAR compensation
Contribution for a better understanding of the technological sustainability in electrical energy production through photovoltaic cells
Authors: Rui Pedro Mendes  , Luís Carrilho Gonçalves  , Pedro Dinis Gaspar
Published: July 2017

The conversion of solar energy into electricity
reveals a huge importance in the production of “clean” energy ,
mainly when applied to decentralized production systems
(micro-generation). However, there is the need to develop and
optimize these processes in order to turn it more sustainable in
economic and technological scoops. The main purpose of this
work is to study the solar energy conversion into electricity
through photovoltaic cells, characterizing the process
efficiencies. This study intends to evaluate the energetic and
exergetic efficiencies defining them as indicators in the
formulation of a sustainability index. All the procedures are in a
theoretical scope with an illustrative example in the end of this
work.
Electric Vehicle. A cyclical story of death and resurrection.
Authors: Portela Núñez J. M  , Pastor Fernandez A  , Huerta Gomez de Merodio M. M  , Otero Mateo Manuel  , Viguera  Cebrian  , Diaz Vázquez J.E
Published: July 2017

An electric car is powered by an electric motor
instead of a gasoline engine. The electric motor gets energy
from a controller, which regulates the amount of power. The
electric car (EV) uses energy stored in its rechargeable
batteries, which are recharged by common household
electricity.
Historically, EVs have not been widely adopted because of
limited driving range before needing to be recharged, long
recharging times, and a lack of commitment by automakers to
produce and market electric cars that have all the creature
comforts of gas-powered cars. That’s changing. As battery
technology improves (increasing energy storage and reducing
cost).
Electric cars no produce CO2 emissions, reduce our dependency
on oil, and are cheaper to operate. Of course, the process of
producing the electricity produce emissions, but even dirty
electricity used in electric cars usually reduces our collective
carbon footprint.
It showed briefly the evolution of electric vehicles associated
with the technological advances and costs.
Wind energy and landscape in Molise – Legislation, Incentives and Problems
Authors: D. Cialdea  , A. Maccarone  , A. Sollazzo
Published: July 2017

The research has the objective to investigate the
wind power energy phenomenon into Molise region and to
relate it with other national and European cases. Looking to the
most recent legislation about renewable energy and landscape,
the research want to give a project’s approach to introduce new
wind towers into regional landscape.
Voltage and Current Sensor for State Estimation in Distribution Network with Generation
Authors: C. Gouveia  , H. Leite  , I. Ferreira
Published: July 2017

The penetration of Distributed Generation into the
distribution networks has been increasing during the last
decades. However, the increase of generation brings additional
technical challenges for the Distribution Network Operators.
Thus, the integration of Distributed Generation along with the
improvement of the quality of service is driving Distribution
Network Operators to actively control their networks. In order
to achieve an effective control of the distribution network it is
necessary to estimate the voltage on the network. This paper
presents a method to accurately estimate voltage on the MV
Network from limited measures of voltage and current. A
method to determine the best location to place those voltage and
current sensors is also explained
Statistical study of the influence of the data sampling interval on the estimation of wind turbine energy
Authors: Dhaker Abbes  , André Martinez  , Gérard Champenois  , Jean Paul Gaubert
Published: July 2017

Main deficiency for wind power is variability. It
is really difficult to predetermine the wind’s potential since
wind velocity cannot be controlled or predicted with
pinpoint accuracy.
In this paper, two different methods are applied in order
to estimate the monthly wind energy for different sites;
those estimations are done using Weibull distribution and
calculating energy with direct integration methodology.
In additional, the influence of the data sampling interval is
studied. Results show that the computational method
based on the integration of the power is more accurate.
Also, it is shown that the hourly time resolution provides
satisfactory accuracy in wind resource estimation, in
comparison with one minute’s resolution.
Results allow better design of wind or hybrid systems.
Moreover, wind speed acquisitions are minimized. A
shorter time of treatment and less expensive measurement
equipments are required.
Simulation of Integration of Distributed Generation into Power System Control
Authors: D. Divényi  , A. Dán
Published: July 2017

The paper deals with modeling of theintegration of  distributed  generation  into  the  central  dispatching  system with  regard  to  the  electricity  market  environment.  Due  to  the large  number  of  the  relative  small  unit  power  of  distributed generation the resulting reserve power can achieve a remarkable quantity.   However   the   utilization   of   these   reserves   is   not obvious    because    of    several    technical    issues    like    the cogeneration of heat power, lack of proper informatics, bounds of law about electric energy (LEE) in Hungary etc. An agent based simulation model was developed to discuss the problem. The model consists of the distributed generation units (DG-s)  and  the  DG-concentrator  (DGC)  which  is  an  interface between   DG-s   and   the   independent   transmission   system operator  (TSO).  All  of  them  are  simulated  as  autonomous software units suitable for decision making, learning and multi-direction  communication.  This  is  a  multi-agent  system,  where the   service,   control   and   simulation   of   stochastic   demand variation are easy to study. Several   scenarios   were   discussed   regarding   the   contracts between DG-s and TSO. The financial paragraph of the contract should ensure the willingness of private owned DG-s to provide their   reserves   for   the   central   control.   The   results   of   the simulation  help  to  find  the  minimum  loss  operation  of  the system.
DEVELOPMENT OF AN INSTALLATION TO REDUCE THE TEMPERATURE OF PHOTOVOLTAIC MODULES AND IMPROVE THEIR EFFICIENCY
Authors: R. Mazón-Hernández  , JR García-Cascales  , F Vera-García  , A Sánchez-Kaiser  , B Zamora-Parra
Published: July 2017

. The main priority in photovoltaic panels is
electricity production. The transformation of solar
energy into electricity depends on the operating
temperature in such a way that the lower the
temperature is, the better the performance of the
panels is. In the existing literature, different cooling
techniques may be found. Most of them propose the
use of air or water as thermal energy carriers. This
paper is focused on the use of these cooling
techniques in photovoltaic panels placed onto the
roof of a greenhouse. So, the objective of this study is
to ensure a low operating temperature which corrects
and reverses the effects produced by high
temperature on efficiency.
Results of an experimental study of a solar cooling system in Jaén using single effect lithium bromide absorption chiller
Authors: A. Gómez Moreno  , P.J. Casanova Peláez  , F.A. Díaz Garrido  , J.M. Palomar Carnicero  , R. López García  , F. Cruz Peragón
Published: July 2017

The potential of absorption machines to cool, in particular, in
house air-conditioning systems is well-known. Using solar
thermal energy helps decreasing air-conditioning systems CO2
emissions. The purpose of this work is to prove the
effectiveness of this kind of systems to cool an average house
during summertime. The setting uses an unit heater for heat
dissipation. The cooling coil decreases the COP setting because
the dissipation depends on external temperature. Using another
renewable source of energy, like geothermal energy (Ground
Source Heat Pump, GSHP), would improve the performance of
the setting because, from a certain depth, ground temperature is
practically constant and it is lower. The goal of this article is to
present the design of the system as well as some first results for
several representative days in August 2009.
Polymer Based Piezoelectric Energy Microgenerator
Authors: V. Janicek  , M. Husak
Published: July 2017

The interest in application of all kinds of
electronic devices and everyday’s demand on implementation
of microelectromechanical systems in the last decade has
produced rapid progress in the efforts of miniaturizing sensors
and actuators. This paper describes microsystem with integrated
power source on piezoelectric principle with pressure sensor.
It's meant to be implemented without any physical contact to
the outside world. It is energy sufficient and easy to produce
with printing technology. It uses the PVDF polymer material.
Simulation of Photovoltaic Generators and Comparison of two common Maximum Power Point trackers.
Authors: Abdallah Zegaoui  , Pierre Petit  , Jean Paul Sawicki  , Jean Pierre Charles  , Michel Aillerie  , M.  DellaKrachai  , A.O.Belarbi
Published: July 2017

Maximum power point tracker algorithms play an
important role in the optimization of the power and the
efficiency of a photovoltaic generator ‘PVG’. We made the
comparison between two algorithms currently implemented for
the power optimization of PVG. These algorithms are based on
the Perturb & Observe and the Conductance-Increment methods
allowing the Maximum Power Point Tracking, ‘MPPT’,
principle. The study leads us to conclude that these algorithms
are not well adapted for PVG exposures in very unfavorable but
realistic external conditions.
Off-Grid PV System to Supply a Rural School on DC Network
Authors: Freitas A. A.  , Daher, S  , Antunes, F  , Ximenes, S  , Viana, F  , Sá Jr E  , Silva, F. S  , Soares, E. A.
Published: July 2017

This paper presents the development of a photovoltaic (PV)
system to supply electric energy to a typical rural school in the
countryside of the sunny Northern East of Brazil. The system is
designed to supply a rural school for up to two days, even under
minimum solar radiation conditions. The solar energy is
captured by PV panels and stored in lead acid batteries. The
solar battery charger (A boost converter) extracts the maximum
power from the PV panels for any radiation. The load is
supplied through a high gain boost converter (24 Vcc to 311
Vcc) and the entire system is controlled by a microcontroller,
which runs the MPP algorithm, monitors the charge state of the
batteries and controls the operation of the DC/DC boost
converter according to the load demand.
Comparison of different solutions for blocking diode applications in a photovoltaic panel under varying ambient conditions
Authors: H.C. Neitzert  , A. Astone
Published: July 2017

We characterized a crystalline silicon based
minimodule under varying ambient conditions, developed a
PSPICE model for this panel, including temperature and
irradiation dependence and applied this model to the simulation
of the impact of a blocking diode under different ambient
conditions. Different blocking diodes were examined, like
germanium and silicon homojunction diodes and silicon
Schottky diodes and compared to “intelligent” diodes,
consisting of operational amplifiers with MOSFET switches.
We calculated a strongly reduced power loss in a panel
integrating the “intelligent” blocking diodes even when
compared to silicon Schottky diodes with a rather low voltage
drop.
Integration of PV systems into low voltage networks using standard load profiles
Authors: M. Eisenreich  , G. Balzer  , J. Backes  , B. Maurer
Published: July 2017

The impact of a higher share of distributed
generation units is shown using the example of PV systems. A
LV network with partly meshed and partly radial topology has
been examined. Standard load profiles have been applied to
obtain results with a resolution of 15 minutes. Feed-in profiles
are compared with a data set based on measured values to
model PV generation. Two extreme cases for transformer
loading and compliance with voltage limits are high load
(winter) without PV and low load (summer) with PV feed-in. In
the latter case, power flow via the transformer was reversed
during certain periods of the day. At the same time, voltage was
increased especially at a long electrical distance from the
transformer.
Investigation of Power Quality In Health Care Facility
Authors: Rusdy Hartungi  , Liben Jiang
Published: July 2017

Modern healthcare facility has unique power
system requirements as the power quality and reliability is a
crucial feature to maintain the critical services such as surgical
operations, intensive care units and other critical services.
Healthcare facility has become dependent on the quality of
electrical supply. This paper aims at assessing the level of
harmonic pollution to a health care facility. The investigation
focus on assessing the level of THD on this healthcare
facilitates. Further discussion includes various ways of
reducing harmonics in health care facilities from the study it
was found that although there are numerous amount of
harmonics producing equipments exist, the total harmonics
distortion is still within the recommended level as advise by
IEEE 519. There is also clear evidence that active filter using
active harmonics conditioner play an important role to this
instance.
Renewable energy plants: environmental compatibility and external costs assessment at global, regional and local scale
Authors: E. Brizio  , G. Genon  , F. Becchis  , D. Russolillo
Published: July 2017

In Italy and many European countries energy
production from biomass is encouraged by strong economic
subsidies (in Italy up to 280 €/MWh granted through a feed-in
tariff linked to the electrical production) so that biomass energy
plants are getting large diffusion. Nevertheless, this kind of
energy plant can involve heavy PM10, NOx, ammonia, methane
and N2O emissions, as well as indirect emissions relating to
cultivation, transport, fertilizers’ production. Within the
described outline, the definition of the environmental
compatibility as well as technological and economic issues
dealing with the emerging renewable energy scenario is of
primary importance. This evaluation should take into account
global parameters as well as environmental impacts at regional
and local scale coming from new polluting emissions. The
environmental balances regarding new energy plants are of
primary importance within very polluted areas such as Northern
Italy where air quality limits are systematically exceeded. The
paper analyses the energy and environmental performances of
anaerobic co-digestion of manure and energy crops, wood and
poultry manure combustion, involving the emissive balances,
analysing different possible energy scenarios, using
environmental economics tools like the ExternE methodology,
an approach devoted to the assessment of the externalities
associated to airborne pollution. The most important conclusion
that can be drawn is that the production of renewable energy
from anaerobic digestion, can strongly increase ammonia and
NOx emissions and, in some cases, also GHG emissions could
be worrying, whereas the application of best available
techniques to waste gas cleaning and energy recovery allows
positive environmental balances.
COMPARATIVE STUDY OF TWO COGENERATION SYSTEMS BASED ON ENERGY RECOVERY OF FUMES FROM A CASTING PROCESS
Authors: M. Fernández  , C J Renedo  , J. García  , S. Pérez  , I. Fernández  , M. Mañana
Published: July 2017

This paper develops the comparison of two
cogeneration systems that are suitable to
perform heat energy recovery of the smoke
produced by a casting process.
ENERGY EFFICIENCY IN DATA PROCESSING CENTERS
Authors: Redondo Gil Carlos
Published: July 2017

On a global scale, IT equipment is responsible for 2% of CO2
emissions, the same quantity as that emitted by the totality of airline
companies world-wide.
Furthermore, and as a point of reference, electricity consumption by
data processing centers in the USA constitutes approximately 2% of
total national electricity consumption. This high rate of consumption
implies that IT is currently the second most contaminating industry on
the planet, surpassed only, once again, by the aeronautical industry.
However, given its present rate of growth, IT will shortly head the list.
This article assesses the present and future situation of IT center energy
consumption and associated environmental effects, and also looks at
how state-of-the-art technology, correctly implemented, could ensure
significant rationalization of data processing center energy
consumption. The article will examine optimization techniques,
specific problems and case studies.
Biomass for energy production characteristics, amount and distribution in Latvia
Authors: Janis Kalnacs  , Andis Lazdinsh
Published: July 2017

Biomass is one of the largest renewable energy sources in
Latvia. Since 54,7 % of the state area is covered by forests, the
firewood, wood chips and pellets play a significant role in the
heat production, especially at households and municipal heating
facilities. Wood chips and pellets are also important export
products. Changes in the energy-producing wood export since
1997 are explained. Other kinds of biomass that can be used for
heat and electricity production are various agricultural and food
production residues, livestock breeding buy-products, sewage
sludge, combustible (organic) part of household and industrial
wastes, etc.
In the present paper, a variety of biomass forms used as the
energy sources are analysed. The characteristics of different
types of wood biomass and the variations in their parameters
are considered. The following determined parameters of
biomass are presented: the calorific value, ash content, bulk
density, melting point of ashes, sulphur and chlorine content,
and others. The biomass energy potential calculated for
different regions of Latvia (the data of 2007) is discussed. On
the map of Latvia the amount and energy potential of
agricultural straw and other biomass for different regions are
shown.
Some recommendations elaborated how to improve biomass
utilization for heat and electricity production.
Optimization of Direct Power Control of Three-Phase Active Rectifiers by using Multiple Switching Tables
Authors: J.G. Norniella  , J.M. Cano  , G.A. Orcajo  , C.H. Rojas  , J.F. Pedrayes  , M.F. Cabanas  , M.G. Melero
Published: July 2017

One of the best known control methods for three-phase  active  rectifiers  is  the  so-called  Direct  Power  Control (DPC).  Control algorithm in DPC is based on the regulation of instantaneous  active  and  reactive  powers  and  incorporates  a switching  table  where  the  successive  optimal  configurations  of the  rectifier  are  stored.  Traditional  DPC  models  use  only  one switching  table  within  their  control  systems.  In  this  study,  a new DPC method is presented, based on the combination of two different  switching  tables.  By  using  Simulink  simulations,  it  is demonstrated  that  better  dynamics  and  lower  switching  stress are  achieved  in  the  rectifier  thanks  to  the  use  of  the  proposed method, in comparison to the simple switching table models.
Probabilistic energy storage sizing for reducing wind power forecast uncertainty
Authors: H. Bludszuweit  , J.A. Domínguez
Published: July 2017

A novel method is proposed for designing an
energy storage system (ESS) which is dedicated to reducing the
uncertainty of the short term wind power forecast. The
investigation focuses on the statistical behaviour of the forecast
error and the state of charge (SOC) of the ESS. This approach
gives an insight into the influence of the forecast conditions on
the distribution of SOC. With this knowledge, an optimised
sizing of the ESS can be done with a well defined uncertainty
limit.
One-year power output data measurements and two types for
forecast were used for this study. In addition, different forecast
quality degrees are simulated based on the persistence
approach. With the forecast data, empirical probability density
functions (pdf's) of the SOC are generated which is the base of
the proposed method.
This approach can lead to a considerable reduction of the ESS
and provides important information about the unserved energy.
This unserved energy is the remaining forecast error or
uncertainty. As a consequence, the proposed probabilistic
method permits the sizing of the energy storage system as a
function of the desired remaining forecast uncertainty.