Abstract: Parabolic solar trough systems have seen limited
deployments in cold northern climates as they are more suitable for
electricity production in southern latitudes. A numerical dynamic
model is developed to simulate troughs installed in cold climates and
validated using a parabolic solar trough facility in Winnipeg. The
model is developed in Simulink and will be utilized to simulate a trigeneration
system for heating, cooling and electricity generation in
remote northern communities. The main objective of this simulation
is to obtain operational data of solar troughs in cold climates and use
the model to determine ways to improve the economics and address
cold weather issues.
In this paper the validated Simulink model is applied to simulate a
solar assisted absorption cooling system along with electricity
generation using Organic Rankine Cycle (ORC) and thermal storage.
A control strategy is employed to distribute the heated oil from solar
collectors among the above three systems considering the
temperature requirements. This modelling provides dynamic
performance results using measured meteorological data recorded
every minute at the solar facility location. The purpose of this
modeling approach is to accurately predict system performance at
each time step considering the solar radiation fluctuations due to
passing clouds. Optimization of the controller in cold temperatures is
another goal of the simulation to for example minimize heat losses in
winter when energy demand is high and solar resources are low.
The solar absorption cooling is modeled to use the generated heat
from the solar trough system and provide cooling in summer for a
greenhouse which is located next to the solar field.
The results of the simulation are presented for a summer day in
Winnipeg which includes comparison of performance parameters of
the absorption cooling and ORC systems at different heat transfer
fluid (HTF) temperatures.
Abstract: In this paper we propose a discrete tracking control of
nonholonomic mobile robots with two degrees of freedom. The
electromechanical model of a mobile robot moving on a horizontal
surface without slipping, with two rear wheels controlled by two
independent DC electric, and one front roal wheel is considered. We
present backstepping design based on the Euler approximate discretetime
model of a continuous-time plant. Theoretical considerations are
verified by numerical simulation.
Abstract: An innovative concept called “Flexy-Energy” is developing at 2iE. This concept aims to produce electricity at lower cost by smartly mix different available energy sources in accordance to the load profile of the region. With a higher solar irradiation and due to the fact that Diesel generator are massively used in sub-Saharan rural areas, PV/Diesel hybrid systems could be a good application of this concept and a good solution to electrify this region, provided they are reliable, cost effective and economically attractive to investors. Presentation of the developed approach is the aims of this paper. The PV/Diesel hybrid system designed consists to produce electricity and/or heat from a coupling between Diesel Diesel generators and PV panels without batteries storage, while ensuring the substitution of gasoil by bio-fuels available in the area where the system will be installed. The optimal design of this system is based on his technical performances; the Life Cycle Cost (LCC) and Levelized Cost of Energy are developed and use as economic criteria. The Net Present Value (NPV), the internal rate of return (IRR) and the discounted payback (DPB) are also evaluated according to dual electricity pricing (in sunny and unsunny hours). The PV/Diesel hybrid system obtained is compared to the standalone Diesel Diesel generators. The approach carried out in this paper has been applied to Siby village in Mali (Latitude 12 ° 23'N 8 ° 20'W) with 295 kWh as daily demand.This approach provides optimal physical characteristics (size of the components, number of component) and dynamical characteristics in real time (number of Diesel generator on, their load rate, fuel specific consumptions, and PV penetration rate) of the system. The system obtained is slightly cost effective; but could be improved with optimized tariffing strategies.
Abstract: This paper attempts to define the validity domain of
LSDP (Loop Shaping Design Procedure) controller system, by
determining the suitable uncertainty region, so that linear system be
stable. Indeed the LSDP controller cannot provide stability for any
perturbed system. For this, we will use the gap metric tool that is
introduced into the control literature for studying robustness
properties of feedback systems with uncertainty. A 2nd order electric
linear system example is given to define the validity domain of LSDP
controller and effectiveness gap metric.
Abstract: In the present work, the dielectric properties of
Epoxy/MWCNT-muscovite HYBRID and MIXED composites based
on a ratio 30:70 were studied. The multi-wall carbon nanotubes
(MWCNT) were prepared using two methods: (a) MWCNTmuscovite
hybrids were synthesised by chemical vapour deposition
(CVD) and (b) physically mixing muscovite with MWCNT. The
effects of different preparation of the composites and filler loading
were evaluated. It was revealed that the dielectric constants of
HYBRID epoxy composites are slightly higher than MIXED epoxy
composites. It was also indicated that the dielectric constant increased
by increasing the MWCNT filler loading.
Abstract: The FOSDT (the First Order Shear Deformation
Theory) is taking into consideration to study the static behavior of a
bimorph beam, with a delamination zone between the upper and the
lower layer. The effect of limit conditions and lengths of the
delamination zone are presented in this paper, with a PVDF
piezoelectric material application. A FEM “Finite Element Method”
is used to discretize the beam. In the axial displacement, a
displacement field appears in the debonded zone with inverse effect
between the upper and the lower layer was observed.
Abstract: This study aimed to examine the management and
development of forest tourism Kamchanoad. Ban Dung, Udon Thani
sustainability. Data were collected by means of qualitative research
including in-depth interviews, semi- structured, and then the data
were summarized and discussed in accordance with the objectives.
And make a presentation in the form of lectures. The target
population for the study consisted of 16 people, including
representatives from government agencies, community leaders and
the community. The results showed that Guidelines for the
Management and Development of Forest Tourism Kamchanoad
include management of buildings and infrastructure such as roads,
water, electricity, toilets. Other developments are the establishment
of a service center that provides information and resources to
facilitate tourists.; nature trails and informative signage to educate
visitors on the path to the jungle Kamchanoad; forest activities for
tourists who are interested only in occasional educational activities
such as vegetation, etc.; disseminating information on various aspects
of tourism through various channels in both Thailand and English, as
well as a web site to encourage community involvement in the
planning and management of tourism together with the care and
preservation of natural resources and preserving the local cultural
tourist area of Kamchanoad.
Abstract: Theory of interpretation of electromagnetic fields studied in the electrical prospecting with direct current is mainly developed for the case of a horizontal surface observation. However in practice we often have to work in difficult terrain surface. Conducting interpretation without the influence of topography can cause non-existent anomalies on sections. This raises the problem of studying the impact of different shapes of ground surface relief on the results of electrical prospecting's research. This research examines the numerical solutions of the direct problem of electrical prospecting for two-dimensional and three-dimensional media, taking into account the terrain. The problem is solved using the method of integral equations. The density of secondary currents on the relief surface is obtained.
Abstract: This paper discusses the design and analysis of a
hybrid PV-Fuel cell energy system destined to power a DC load. The
system is composed of a photovoltaic array, a fuel cell, an
electrolyzer and a hydrogen tank. HOMER software is used in this
study to calculate the optimum capacities of the power system
components that their combination allows an efficient use of solar
resource to cover the hourly load needs. The optimal system sizing
allows establishing the right balance between the daily electrical
energy produced by the power system and the daily electrical energy
consumed by the DC load using a 28 KW PV array, a 7.5 KW fuel
cell, a 40KW electrolyzer and a 270 Kg hydrogen tank. The variation
of powers involved into the DC bus of the hybrid PV-fuel cell system
has been computed and analyzed for each hour over one year: the
output powers of the PV array and the fuel cell, the input power of
the elctrolyzer system and the DC primary load. Equally, the annual
variation of stored hydrogen produced by the electrolyzer has been
assessed. The PV array contributes in the power system with 82%
whereas the fuel cell produces 18%. 38% of the total energy
consumption belongs to the DC primary load while the rest goes to
the electrolyzer.
Abstract: This paper shows an experimental testing of a small
unit for combustion of solid fuels, such as charcoal and wood logs,
that can provide electricity. One of the concepts is that the unit does
not require qualified personnel for its operation. The unit itself is
composed of two main parts. The design requires a heat producing
stove and electricity producing thermoelectric generator. After the
construction the unit was tested and the results show that the
emission release is within the legislative requirements for emission
production and environmental protection. That qualifies such unit for
indoor application.
Abstract: Thin-walled elements with a matrix set on a base of
high-valuable Portland cement with dispersed reinforcement from
alkali-resistant glass fibres are used in a range of applications as
claddings of buildings and infrastructure constructions as well as
various architectural elements of residential buildings.
Even though their elementary thickness and therefore total weight
is quite low, architects and building companies demand on even
further decreasing of the bulk density of these fibre-cement elements
for the reason of loading elimination of connected superstructures
and easier assembling in demand conditions.
By the means of various kinds of light-weight aggregates it is
possible to achieve light-weighing of these composite elements.
From the range of possible fillers with different material properties
granulated expanded glass worked the best.
By the means of laboratory testing an effect of two fillers based on
expanded glass on the fibre reinforced cement composite was
verified.
Practical applicability was tested in the production of commonly
manufactured glass fibre reinforced concrete elements, such as
channels for electrical cable deposition, products for urban equipment
and especially various cladding elements.
Even though these are not structural elements, it is necessary to
evaluate also strength characteristics and resistance to environment
for their durability in certain applications.
Abstract: Meeting the growth in demand for digital services
such as social media, telecommunications, and business and cloud
services requires large scale data centres, which has led to an increase
in their end use energy demand. Generally, over 30% of data centre
power is consumed by the necessary cooling overhead. Thus energy
can be reduced by improving the cooling efficiency. Air and liquid
can both be used as cooling media for the data centre. Traditional
data centre cooling systems use air, however liquid is recognised as a
promising method that can handle the more densely packed data
centres. Liquid cooling can be classified into three methods; rack heat
exchanger, on-chip heat exchanger and full immersion of the
microelectronics. This study quantifies the improvements of heat
transfer specifically for the case of immersed microelectronics by
varying the CPU and heat sink location. Immersion of the server is
achieved by filling the gap between the microelectronics and a water
jacket with a dielectric liquid which convects the heat from the CPU
to the water jacket on the opposite side. Heat transfer is governed by
two physical mechanisms, which is natural convection for the fixed
enclosure filled with dielectric liquid and forced convection for the
water that is pumped through the water jacket. The model in this
study is validated with published numerical and experimental work
and shows good agreement with previous work. The results show that
the heat transfer performance and Nusselt number (Nu) is improved
by 89% by placing the CPU and heat sink on the bottom of the
microelectronics enclosure.
Abstract: The characteristics of temperature distribution and
electric field in a natural rubber glove (NRG) using microwave
energy during microwave heating process are investigated
numerically and experimentally. A three-dimensional model of NRG
and microwave oven are considered in this work. The influences of
position, heating time and rotation angle of NRG on temperature
distribution and electric field are presented in details. The coupled
equations of electromagnetic wave propagation and heat transfer are
solved using the finite element method (FEM). The numerical model
is validated with an experimental study at a frequency of 2.45 GHz.
The results show that the numerical results closely match the
experimental results. Furthermore, it is found that the temperature
distribution and electric field increases with increasing heating time.
The hot spot zone appears in NRG at the tip of middle finger while
the maximum temperature occurs in case of rotation angle of NRG =
60 degree. This investigation provides the essential aspects for a
fundamental understanding of heat transport of NRG using
microwave energy in industry.
Abstract: Ti6Al4V alloy is highly used in the automotive and
aerospace industry due to its good machining characteristics. Micro
EDM drilling is commonly used to drill micro hole on extremely hard
material with very high depth to diameter ratio. In this study, the
parameters of micro-electrical discharge machining (EDM) in drilling
of Ti6Al4V alloy is optimized for higher machining accuracy with
less hole-dilation and hole taper ratio. The micro-EDM machining
parameters includes, peak current and pulse on time. Fuzzy analysis
was developed to evaluate the machining accuracy. The analysis
shows that hole-dilation and hole-taper ratio are increased with the
increasing of peak current and pulse on time. However, the surface
quality deteriorates as the peak current and pulse on time increase.
The combination that gives the optimum result for hole dilation is
medium peak current and short pulse on time. Meanwhile, the
optimum result for hole taper ratio is low peak current and short pulse
on time.
Abstract: China is currently the world's largest producer and distributor of electric bicycle (e-bike). The increasing number of e-bikes on the road is accompanied by rising injuries and even deaths of e-bike drivers. Therefore, there is a growing need to improve the safety structure of e-bikes. This 3D frictionless contact analysis is a preliminary, but necessary work for further structural design improvement of an e-bike. The contact analysis between e-bike and the ground was carried out as follows: firstly, the Penalty method was illustrated and derived from the simplest spring-mass system. This is one of the most common methods to satisfy the frictionless contact case; secondly, ANSYS static analysis was carried out to verify finite element (FE) models with contact pair (without friction) between e-bike and the ground; finally, ANSYS transient analysis was used to obtain the data of the penetration p(u) of e-bike with respect to the ground. Results obtained from the simulation are as estimated by comparing with that from theoretical method. In the future, protective shell will be designed following the stability criteria and added to the frame of e-bike. Simulation of side falling of the improvedsafety structure of e-bike will be confirmed with experimental data.
Abstract: In this paper, we consider the vehicle routing problem
with mixed fleet of conventional and heterogenous electric vehicles
and time dependent charging costs, denoted VRP-HFCC, in which
a set of geographically scattered customers have to be served by a
mixed fleet of vehicles composed of a heterogenous fleet of Electric
Vehicles (EVs), having different battery capacities and operating
costs, and Conventional Vehicles (CVs). We include the possibility
of charging EVs in the available charging stations during the routes
in order to serve all customers. Each charging station offers charging
service with a known technology of chargers and time dependent
charging costs. Charging stations are also subject to operating time
windows constraints. EVs are not necessarily compatible with all
available charging technologies and a partial charging is allowed.
Intermittent charging at the depot is also allowed provided that
constraints related to the electricity grid are satisfied.
The objective is to minimize the number of employed vehicles and
then minimize the total travel and charging costs.
In this study, we present a Mixed Integer Programming Model and
develop a Charging Routing Heuristic and a Local Search Heuristic
based on the Inject-Eject routine with different insertion methods. All
heuristics are tested on real data instances.
Abstract: This paper presents two types of microstrip bandpass
filter (BPF) at microwave frequencies. The first one is a tunable BPF
using planar patch resonators based on a varactor diode. The filter is
formed by a triple mode circular patch resonator with two pairs of
slots, in which the varactor diodes are connected. Indeed, this filter is
initially centered at 2.4 GHz; the center frequency of the tunable
patch filter could be tuned up to 1.8 GHz simultaneously with the
bandwidth, reaching high tuning ranges. Lossless simulations were
compared to those considering the substrate dielectric, conductor
losses and the equivalent electrical circuit model of the tuning
element in order to assess their effects. Within these variations,
simulation results showed insertion loss better than 2 dB and return
loss better than 10 dB over the passband. The second structure is a
BPF for ultra-wideband (UWB) applications based on multiple-mode
resonator (MMR) and rectangular-shaped defected ground structure
(DGS). This filter, which is compact size of 25.2 x 3.8 mm2, provides
in the pass band an insertion loss of 0.57 dB and a return loss greater
than 12 dB. The proposed filters presents good performances and the
simulation results are in satisfactory agreement with the
experimentation ones reported elsewhere.
Abstract: This study investigates the cleaning performance of
high intensity 360 kHz frequency on removal of nano-dimensional
and sub-micron particles from various surfaces, uniformity of the
cleaning tank and run to run variation of cleaning process. The
uniformity of the cleaning tank was measured by two different
methods i.e. 1. ppbTM meter and 2. Liquid Particle Counting (LPC)
technique. The result indicates that the energy was distributed more
uniformly throughout the entire cleaning vessel even at the corners
and edges of the tank when megasonic sweeping technology is
applied. The result also shows that rinsing the parts with 360 kHz
frequency at final rinse gives lower particle counts, hence higher
cleaning efficiency as compared to other frequencies. When
megasonic sweeping technology is applied each piezoelectric
transducers will operate at their optimum resonant frequency and
generates stronger acoustic cavitational force and higher acoustic
streaming velocity. These combined forces are helping to enhance the
particle removal and at the same time improve the overall cleaning
performance. The multiple extractions study was also carried out for
various frequencies to measure the cleaning potential and asymptote
value.
Abstract: In recent years, the hair building fiber has become
popular, in other words, it is an effective method which helps people
who suffer hair loss or sparse hair since the hair building fiber is
capable to create a natural look of simulated hair rapidly. In the
markets, there are a lot of hair fiber brands that have been designed to
formulate an intense bond with hair strands and make the hair appear
more voluminous instantly. However, those products have their own
set of properties. Thus, in this report, some measurement techniques
are proposed to identify those products. Up to five different brands of
hair fiber are tested. The electrostatic and dielectric properties of the
hair fibers are macroscopically tested using design DC and high
frequency microwave techniques. Besides, the hair fibers are
microscopically analysis by magnifying the structures of the fiber
using scanning electron microscope (SEM). From the SEM photos,
the comparison of the uniformly shaped and broken rate of the hair
fibers in the different bulk samples can be observed respectively.
Abstract: Composite material based on Fe3Si micro-particles
and Mn-Zn nano-ferrite was prepared using powder metallurgy
technology. The sol-gel followed by autocombustion process was
used for synthesis of Mn0.8Zn0.2Fe2O4 ferrite. 3 wt.% of mechanically
milled ferrite was mixed with Fe3Si powder alloy. Mixed micro-nano
powder system was homogenized by the Resonant Acoustic Mixing
using ResodynLabRAM Mixer. This non-invasive homogenization
technique was used to preserve spherical morphology of Fe3Si
powder particles. Uniaxial cold pressing in the closed die at pressure
600 MPa was applied to obtain a compact sample. Microwave
sintering of green compact was realized at 800°C, 20 minutes, in air.
Density of the powders and composite was measured by
Hepycnometry. Impulse excitation method was used to measure
elastic properties of sintered composite. Mechanical properties were
evaluated by measurement of transverse rupture strength (TRS) and
Vickers hardness (HV). Resistivity was measured by 4 point probe
method. Ferrite phase distribution in volume of the composite was
documented by metallographic analysis.
It has been found that nano-ferrite particle distributed among
micro- particles of Fe3Si powder alloy led to high relative density
(~93%) and suitable mechanical properties (TRS >100 MPa, HV
~1GPa, E-modulus ~140 GPa) of the composite. High electric
resistivity (R~6.7 ohm.cm) of prepared composite indicate their
potential application as soft magnetic material at medium and high
frequencies.