Abstract: This paper presents a compact thermoelectric power generator system based on temperature difference across the element. The system can transfer the burning heat energy to electric energy directly. The proposed system has a thermoelectric generator and a power control box. In the generator, there are 4 thermoelectric modules (TEMs), each of which uses 2 thermoelectric chips (TEs) and 2 cold sinks, 1 thermal absorber, and 1 thermal conduction flat board. In the power control box, there are 1 storing energy device, 1 converter, and 1 inverter. The total net generating power is about 11W. This system uses commercial portable gas stoves or burns timber or the coal as the heat source, which is easily obtained. It adopts solid-state thermoelectric chips as heat inverter parts. The system has the advantages of being light-weight, quite, and mobile, requiring no maintenance, and havng easily-supplied heat source. The system can be used a as long as burning is allowed. This system works well for highly-mobilized outdoors situations by providing a power for illumination, entertainment equipment or the wireless equipment at refuge. Under heavy storms such as typhoon, when the solar panels become ineffective and the wind-powered machines malfunction, the thermoelectric power generator can continue providing the vital power.
Abstract: Electrospinning is a broadly used technology to obtain
polymeric nanofibers ranging from several micrometers down to
several hundred nanometers for a wide range of applications. It offers
unique capabilities to produce nanofibers with controllable porous
structure. With smaller pores and higher surface area than regular
fibers, electrospun fibers have been successfully applied in various
fields, such as, nanocatalysis, tissue engineering scaffolds, protective
clothing, filtration, biomedical, pharmaceutical, optical electronics,
healthcare, biotechnology, defense and security, and environmental
engineering. In this study, polyurethane nanofibers were obtained
under different electrospinning parameters. Fiber morphology and
diameter distribution were investigated in order to understand them
as a function of process parameters.
Abstract: In this paper we compare the response of linear and
nonlinear neural network-based prediction schemes in prediction of
received Signal-to-Interference Power Ratio (SIR) in Direct
Sequence Code Division Multiple Access (DS/CDMA) systems. The
nonlinear predictor is Multilayer Perceptron MLP and the linear
predictor is an Adaptive Linear (Adaline) predictor. We solve the
problem of complexity by using the Minimum Mean Squared Error
(MMSE) principle to select the optimal predictors. The optimized
Adaline predictor is compared to optimized MLP by employing
noisy Rayleigh fading signals with 1.8 GHZ carrier frequency in an
urban environment. The results show that the Adaline predictor can
estimates SIR with the same error as MLP when the user has the
velocity of 5 km/h and 60 km/h but by increasing the velocity up-to
120 km/h the mean squared error of MLP is two times more than
Adaline predictor. This makes the Adaline predictor (with lower
complexity) more suitable than MLP for closed-loop power control
where efficient and accurate identification of the time-varying
inverse dynamics of the multi path fading channel is required.
Abstract: The inherent iterative nature of product design and development poses significant challenge to reduce the product design and development time (PD). In order to shorten the time to market, organizations have adopted concurrent development where multiple specialized tasks and design activities are carried out in parallel. Iterative nature of work coupled with the overlap of activities can result in unpredictable time to completion and significant rework. Many of the products have missed the time to market window due to unanticipated or rather unplanned iteration and rework. The iterative and often overlapped processes introduce greater amounts of ambiguity in design and development, where the traditional methods and tools of project management provide less value. In this context, identifying critical metrics to understand the iteration probability is an open research area where significant contribution can be made given that iteration has been the key driver of cost and schedule risk in PD projects. Two important questions that the proposed study attempts to address are: Can we predict and identify the number of iterations in a product development flow? Can we provide managerial insights for a better control over iteration? The proposal introduces the concept of decision points and using this concept intends to develop metrics that can provide managerial insights into iteration predictability. By characterizing the product development flow as a network of decision points, the proposed research intends to delve further into iteration probability and attempts to provide more clarity.
Abstract: The aim of the present study is to analyze the generation of osteoporotic vertebral bone induced by lack of calcium during growth period and analyze its effects for disc degeneration, based on biomechanical and histomorphometrical study. Mechanical and histomorphological characteristics of lumbar vertebral bones and discs of rats with calcium free diet (CFD) were detected and tracked by using high resolution in-vivo micro-computed tomography (in-vivo micro-CT), finite element (FE) and histological analysis. Twenty female Sprague-Dawley rats (6 weeks old, approximate weight 170g) were randomly divided into two groups (CFD group: 10, NOR group: 10). The CFD group was maintained on a refmed calcium-controlled semisynthetic diet without added calcium, to induce osteoporosis. All lumbar (L 1-L6) were scanned by using in vivo micro-CT with 35i.un resolution at 0, 4, 8 weeks to track the effects of CFD on the generation of osteoporosis. The fmdings of the present study indicated that calcium insufficiency was the main factor in the generation of osteoporosis and it induced lumbar vertebral disc degeneration. This study is a valuable experiment to firstly evaluate osteoporotic vertebral bone and disc degeneration induced by lack of calcium during growth period from a biomechanical and histomorphometrical point of view.
Abstract: Off-grid Photovoltaic (PV) systems are empowering
technology in underdeveloped countries like Ethiopia where many
people live far away from the modern world. Where there is
relatively low energy consumption, providing energy from grid
systems is not commercially cost-effective. As a result, significant
people groups worldwide stay without access to electricity. One
remote village in northern Ethiopia was selected by the United
Nations for a pilot project to improve its living conditions. As part of
this comprehensive project, an intelligent charge controller circuit for
Off-grid PV systems was designed for the clinic in that village. In
this paper, design aspects of an intelligent charge controller unit and
its load driver circuits are discussed for an efficient utilization of PVbased
supply systems.
Abstract: In order to assess optical fiber reliability in different environmental and stress conditions series of testing are performed simulating overlapping of chemical and mechanical controlled varying factors. Each series of testing may be compared using statistical processing: i.e. Weibull plots. Due to the numerous data to treat, a software application has appeared useful to interpret selected series of experiments in function of envisaged factors. The current paper presents a software application used in the storage, modelling and interpretation of experimental data gathered from optical fibre testing. The present paper strictly deals with the software part of the project (regarding the modelling, storage and processing of user supplied data).
Abstract: This paper describes the process used in the
automation of the Maritime UAV commands using the Kinect sensor.
The AR Drone is a Quadrocopter manufactured by Parrot [1] to be
controlled using the Apple operating systems such as iPhones and
Ipads. However, this project uses the Microsoft Kinect SDK and
Microsoft Visual Studio C# (C sharp) software, which are compatible
with Windows Operating System for the automation of the navigation
and control of the AR drone.
The navigation and control software for the Quadrocopter runs on
a windows 7 computer. The project is divided into two sections; the
Quadrocopter control system and the Kinect sensor control system.
The Kinect sensor is connected to the computer using a USB cable
from which commands can be sent to and from the Kinect sensors.
The AR drone has Wi-Fi capabilities from which it can be connected
to the computer to enable transfer of commands to and from the
Quadrocopter.
The project was implemented in C#, a programming language that
is commonly used in the automation systems. The language was
chosen because there are more libraries already established in C# for
both the AR drone and the Kinect sensor.
The study will contribute toward research in automation of
systems using the Quadrocopter and the Kinect sensor for navigation
involving a human operator in the loop. The prototype created has
numerous applications among which include the inspection of vessels
such as ship, airplanes and areas that are not accessible by human
operators.
Abstract: In this paper, an improved ant colony optimization
(ACO) algorithm is proposed to enhance the performance of global
optimum search. The strategy of the proposed algorithm has the
capability of fuzzy pheromone updating, adaptive parameter tuning,
and mechanism resetting. The proposed method is utilized to tune the
parameters of the fuzzy controller for a real beam and ball system.
Simulation and experimental results indicate that better performance
can be achieved compared to the conventional ACO algorithms in the
aspect of convergence speed and accuracy.
Abstract: This paper presents the Function Approximation
Technique (FAT) based adaptive impedance control for a robotic
finger. The force based impedance control is developed so that the
robotic finger tracks the desired force while following the reference
position trajectory, under unknown environment position and
uncertainties in finger parameters. The control strategy is divided into
two phases, which are the free and contact phases. Force error
feedback is utilized in updating the uncertain environment position
during contact phase. Computer simulations results are presented to
demonstrate the effectiveness of the proposed technique.
Abstract: Acid rain occurs when sulphur dioxide (SO2) and
nitrogen oxides (Nox) gases react in the atmosphere with water,
oxygen, and other chemicals to form various acidic compounds. The
result is a mild solution of sulfuric acid and nitric acid. Soil has a
greater buffering capacity than aquatic systems. However excessive
amount of acids introduced by acid rains may disturb the entire soil
chemistry. Acidity and harmful action of toxic elements damage
vegetation while susceptible microbial species are eliminated. In
present study, the effects of simulated sulphuric acid and nitric acid
rains were investigated on crop Glycine max. The effect of acid rain
on change in soil fertility was detected in which pH of control sample
was 6.5 and pH of 1%H2SO4 and 1%HNO3 were 3.5. Nitrogen nitrate
in soil was high in 1% HNO3 treated soil & Control sample.
Ammonium nitrogen in soil was low in 1% HNO3 & H2SO4 treated
soil. Ammonium nitrogen was medium in control and other samples.
The effect of acid rain on seed germination on 3rd day of germination
control sample growth was 7 cm, 0.1% HNO3 was 8cm, and 0.001%
HNO3 & 0.001% H2SO4 was 6cm each. On 10th day fungal growth
was observed in 1% and 0.1%H2SO4 concentrations, when all plants
were dead. The effect of acid rain on crop productivity was
investigated on 3rd day roots were developed in plants. On12th day
Glycine max showed more growth in 0.1% HNO3, 0.001% HNO3 and
0.001% H2SO4 treated plants growth were same as compare to control
plants. On 20th day development of discoloration of plant pigments
were observed on acid treated plants leaves. On 38th day, 0.1, 0.001%
HNO3 and 0.1, 0.001% H2SO4 treated plants and control plants were
showing flower growth. On 42th day, acid treated Glycine max variety
and control plants were showed seeds on plants. In Glycine max
variety 0.1, 0.001% H2SO4, 0.1, 0.001% HNO3 treated plants were
dead on 46th day and fungal growth was observed. The toxicological
study was carried out on Glycine max plants exposed to 1% HNO3
cells were damaged more than 1% H2SO4. Leaf sections exposed to
0.001% HNO3 & H2SO4 showed less damaged of cells and
pigmentation observed in entire slide when compare with control
plant. The soil analysis was done to find microorganisms in HNO3 &
H2SO4 treated Glycine max and control plants. No microorganism
growth was observed in 1% HNO3 & H2SO4 but control plant showed
microbial growth.
Abstract: This paper examines the problem of designing a robust H8 state-feedback controller for a class of nonlinear two-time scale systems with Markovian Jumps described by a Takagi-Sugeno (TS) fuzzy model. Based on a linear matrix inequality (LMI) approach, LMI-based sufficient conditions for the uncertain Markovian jump nonlinear two-time scale systems to have an H8 performance are derived. The proposed approach does not involve the separation of states into slow and fast ones and it can be applied not only to standard, but also to nonstandard nonlinear two-time scale systems. A numerical example is provided to illustrate the design developed in this paper.
Abstract: We present a simulation and realization of a battery
charge regulator (BCR) in microsatellite earth observation. The tests
were performed on battery pack 12volt, capacity 24Ah and the solar array open circuit voltage of 100 volt and optimum power of about
250 watt. The battery charge is made by solar module. The principle is to adapt the output voltage of the solar module to the battery by
using the technique of pulse width modulation (PWM). Among the different techniques of charge battery, we opted for the technique of
the controller ON/OFF is a standard technique and simple, it-s easy to
be board executed validation will be made by simulation "Proteus Isis
Professional software ". The circuit and the program of this prototype
are based on the PIC16F877 microcontroller, a serial interface connecting a PC is also realized, to view and save data and graphics
in real time, for visualization of data and graphs we develop an interface tool “visual basic.net (VB)--.
Abstract: This paper presents a fuzzy logic controlled shunt
active power filter used to compensate for harmonic distortion in three-phase four-wire systems. The shunt active filter employs a
simple method for the calculation of the reference compensation current based of Fast Fourier Transform. This presented filter is able
to operate in both balanced and unbalanced load conditions. A fuzzy
logic based current controller strategy is used to regulate the filter current and hence ensure harmonic free supply current. The validity
of the presented approach in harmonic mitigation is verified via
simulation results of the proposed test system under different loading
conditions.
Abstract: This paper reports the fatigue crack growth behaviour
of gas tungsten arc, electron beam and laser beam welded Ti-6Al-4V
titanium alloy. Centre cracked tensile specimens were prepared to
evaluate the fatigue crack growth behaviour. A 100kN servo
hydraulic controlled fatigue testing machine was used under constant
amplitude uniaxial tensile load (stress ratio of 0.1 and frequency of
10 Hz). Crack growth curves were plotted and crack growth
parameters (exponent and intercept) were evaluated. Critical and
threshold stress intensity factor ranges were also evaluated. Fatigue
crack growth behaviour of welds was correlated with mechanical
properties and microstructural characteristics of welds. Of the three
joints, the joint fabricated by laser beam welding exhibited higher
fatigue crack growth resistance due to the presence of fine lamellar
microstructure in the weld metal.
Abstract: Land degradation is of concern in many countries. People more and more must address the problems associated with the degradation of soil properties due to man. Increasingly, organic soil amendments, such as compost are being examined for their potential use in soil restoration and for preventing soil erosion. In the Czech Republic, compost is the most used to improve soil structure and increase the content of soil organic matter. Land reclamation / restoration is one of the ways to evaluate industrially produced compost because Czech farmers are not willing to use compost as organic fertilizer. The most common use of reclamation substrates in the Czech Republic is for the rehabilitation of landfills and contaminated sites.
This paper deals with the influence of reclamation substrates (RS) with different proportions of compost and sand on selected soil properties–chemical characteristics, nitrogen bioavailability, leaching of mineral nitrogen, respiration activity and plant biomass production. Chemical properties vary proportionally with addition of compost and sand to the control variant (topsoil). The highest differences between the variants were recorded in leaching of mineral nitrogen (varies from 1.36mg dm-3 in C to 9.09mg dm-3). Addition of compost to soil improves conditions for plant growth in comparison with soil alone. However, too high addition of compost may have adverse effects on plant growth. In addition, high proportion of compost increases leaching of mineral N. Therefore, mixture of 70% of soil with 10% of compost and 20% of sand may be recommended as optimal composition of RS.
Abstract: Heat pipes are used to control the thermal problem for
electronic cooling. It is especially difficult to dissipate heat to a heat
sink in an environment in space compared to earth. For solving this
problem, in this study, the Poiseuille (Po) number, which is the main
measure of the performance of a heat pipe, is studied by CFD; then, the
heat pipe performance is verified with experimental results. A heat
pipe is then fabricated for a spatial environment, and an in-house code
is developed. Further, a heat pipe subsystem, which consists of a heat
pipe, MLI (Multi Layer Insulator), SSM (Second Surface Mirror), and
radiator, is tested and correlated with the TMM (Thermal
Mathematical Model) through a commercial code. The correlation
results satisfy the 3K requirement, and the generated thermal model is
verified for application to a spatial environment.
Abstract: This paper describes the design of a real-time audiorange
digital oscilloscope and its implementation in 90nm CMOS
FPGA platform. The design consists of sample and hold circuits,
A/D conversion, audio and video processing, on-chip RAM, clock
generation and control logic. The design of internal blocks and
modules in 90nm devices in an FPGA is elaborated. Also the key
features and their implementation algorithms are presented.
Finally, the timing waveforms and simulation results are put
forward.
Abstract: The Combination of path planning and path following is the main purpose of this paper. This paper describes the developed practical approach to motion control of the MRL small size robots. An intelligent controller is applied to control omni-directional robots motion in simulation and real environment respectively. The Brain Emotional Learning Based Intelligent Controller (BELBIC), based on LQR control is adopted for the omni-directional robots. The contribution of BELBIC in improving the control system performance is shown as application of the emotional learning in a real world problem. Optimizing of the control effort can be achieved in this method too. Next the implicit communication method is used to determine the high level strategies and coordination of the robots. Some simple rules besides using the environment as a memory to improve the coordination between agents make the robots' decision making system. With this simple algorithm our team manifests a desirable cooperation.
Abstract: This paper presents the averaging model of a buck
converter derived from the generalized state-space averaging method.
The sliding mode control is used to regulate the output voltage of the
converter and taken into account in the model. The proposed model
requires the fast computational time compared with those of the full
topology model. The intensive time-domain simulations via the exact
topology model are used as the comparable model. The results show
that a good agreement between the proposed model and the switching
model is achieved in both transient and steady-state responses. The
reported model is suitable for the optimal controller design by using
the artificial intelligence techniques.