Abstract: These Monolayer and multilayer coatings of CrN and
AlCrN deposited on 100Cr6 (AISI 52100) substrate by PVD
magnetron sputtering system. The microstructures of the coatings
were characterized using atomic force microscopy (AFM). The AFM
analysis revealed the presence of domes and craters that are
uniformly distributed over all surfaces of the various layers.
Nanoindentation measurement of CrN coating showed maximum
hardness (H) and modulus (E) of 14 GPa and 190 GPa, respectively.
The measured H and E values of AlCrN coatings were found to be 30
GPa and 382 GPa, respectively. The improved hardness in both the
coatings was attributed mainly to a reduction in crystallite size and
decrease in surface roughness. The incorporation of Al into the CrN
coatings has improved both hardness and Young’s modulus.
Abstract: In this paper, influence of harmonics on medium
voltage distribution system of Bogazici Electricity Distribution Inc.
(BEDAS) which takes place at Istanbul/Turkey is investigated. A ring
network consisting of residential loads is taken into account for this
study. Real system parameters and measurement results are used for
simulations. Also, probable working conditions of the system are
analyzed for 50%, 75%, and 100% loading of transformers with
similar harmonic contents. Results of the study are exhibited the
influence of nonlinear loads on %THDV, P.F. and technical losses of
the medium voltage distribution system.
Abstract: In this paper, we present a four-step ortho-rectification
procedure for real-time geo-referencing of video data from a low-cost
UAV equipped with a multi-sensor system. The basic procedures for
the real-time ortho-rectification are: (1) decompilation of the video
stream into individual frames; (2) establishing the interior camera
orientation parameters; (3) determining the relative orientation
parameters for each video frame with respect to each other; (4)
finding the absolute orientation parameters, using a self-calibration
bundle and adjustment with the aid of a mathematical model. Each
ortho-rectified video frame is then mosaicked together to produce a
mosaic image of the test area, which is then merged with a well
referenced existing digital map for the purpose of geo-referencing
and aerial surveillance. A test field located in Abuja, Nigeria was
used to evaluate our method. Video and telemetry data were collected
for about fifteen minutes, and they were processed using the four-step
ortho-rectification procedure. The results demonstrated that the
geometric measurement of the control field from ortho-images is
more accurate when compared with those from original perspective
images when used to pin point the exact location of targets on the
video imagery acquired by the UAV. The 2-D planimetric accuracy
when compared with the 6 control points measured by a GPS receiver
is between 3 to 5 metres.
Abstract: In recent research copper and manganese systems
were found to be the most active in CO and organic compounds
oxidation among the base catalysts. The mixed copper manganese
oxide has been widely studied in oxidation reactions because of their
higher activity at low temperatures in comparison with single oxide
catalysts. The results showed that the formation of spinel
CuxMn3−xO4 in the oxidized catalyst is responsible for the activity
even at room temperature. That is why the most of the investigations
are focused on the hopcalite catalyst (CuMn2O4) as the best coppermanganese
catalyst. Now it’s known that this is true only for CO
oxidation, but not for mixture of CO and VOCs. The purpose of this
study is to investigate the alumina supported copper-manganese
catalysts with different Cu/Mn molar ratio in terms of oxidation of
CO, methanol and dimethyl ether. The catalysts were prepared by impregnation of γ-Al2O3 with
copper and manganese nitrates and the catalytic activity
measurements were carried out in two stage continuous flow
equipment with an adiabatic reactor for simultaneous oxidation of all
compounds under the conditions closest possible to the industrial. Gas
mixtures on the input and output of the reactor were analyzed with a
gas chromatograph, equipped with FID and TCD detectors. The
texture characteristics were determined by low-temperature (- 196oС)
nitrogen adsorption in a Quantachrome Instruments NOVA 1200e
(USA) specific surface area & pore analyzer. Thermal, XRD and
TPR analyses were performed. It was established that the active component of the mixed Cu-
Mn/γ–alumina catalysts strongly depends on the Cu/Mn molar ratio.
Highly active alumina supported Cu-Mn catalysts for CO, methanol
and DME oxidation were synthesized. While the hopcalite is the best
catalyst for CO oxidation, the best compromise for simultaneous
oxidation of all components is the catalyst with Cu/Mn molar ratio
1:5.
Abstract: Neural activity in the human brain starts from the
early stages of prenatal development. This activity or signals
generated by the brain are electrical in nature and represent not only
the brain function but also the status of the whole body. At the
present moment, three methods can record functional and
physiological changes within the brain with high temporal resolution
of neuronal interactions at the network level: the
electroencephalogram (EEG), the magnet oencephalogram (MEG),
and functional magnetic resonance imaging (fMRI); each of these has
advantages and shortcomings. EEG recording with a large number of
electrodes is now feasible in clinical practice. Multichannel EEG
recorded from the scalp surface provides very valuable but indirect
information about the source distribution. However, deep electrode
measurements yield more reliable information about the source
locations intracranial recordings and scalp EEG are used with the
source imaging techniques to determine the locations and strengths of
the epileptic activity. As a source localization method, Low
Resolution Electro-Magnetic Tomography (LORETA) is solved for
the realistic geometry based on both forward methods, the Boundary
Element Method (BEM) and the Finite Difference Method (FDM). In
this paper, we review the findings EEG- LORETA about epilepsy.
Abstract: A comparison of activity and stability of the as-formed
Pt/C, Pt-Co and Pt-Pd/C electrocatalysts, prepared by a combined
approach of impregnation and seeding, was performed. According to
the activity test in a single Proton Exchange Membrane (PEM) fuel
cell, the Oxygen Reduction Reaction (ORR) activity of the Pt-M/C
electrocatalyst was slightly lower than that of Pt/C. The j0.9 V and
E10 mA/cm2 of the as-prepared electrocatalysts increased in the order of
Pt/C > Pt-Co/C > Pt-Pd/C. However, in the medium-to-high current
density region, Pt-Pd/C exhibited the best performance. With regard to
their stability in a 0.5 M H2SO4 electrolyte solution, the
electrochemical surface area decreased as the number of rounds of
repetitive potential cycling increased due to the dissolution of the
metals within the catalyst structure. For long-term measurement, Pt-
Pd/C was the most stable than the other three electrocatalysts.
Abstract: This work studies the effect of chemical composition
on the activity and selectivity of γ–alumina supported CuO/
MnO2/Cr2O3 catalysts toward deep oxidation of CO, dimethyl ether
(DME) and methanol. The catalysts were prepared by impregnation
of the support with an aqueous solution of copper nitrate, manganese
nitrate and CrO3 under different conditions. Thermal, XRD and TPR
analysis were performed. The catalytic measurements of single
compounds oxidation were carried out on continuous flow equipment
with a four-channel isothermal stainless steel reactor. Flow-line
equipment with an adiabatic reactor for simultaneous oxidation of all
compounds under the conditions that mimic closely the industrial
ones was used. The reactant and product gases were analyzed by
means of on-line gas chromatographs.
On the basis of XRD analysis it can be concluded that the active
component of the mixed Cu-Mn-Cr/γ–alumina catalysts consists of at
least six compounds – CuO, Cr2O3, MnO2, Cu1.5Mn1.5O4,
Cu1.5Cr1.5O4 and CuCr2O4, depending on the Cu/Mn/Cr molar ratio.
Chemical composition strongly influences catalytic properties, this
influence being quite variable with regards to the different processes.
The rate of CO oxidation rapidly decrease with increasing of
chromium content in the active component while for the DME was
observed the reverse trend. It was concluded that the best
compromise are the catalysts with Cu/(Mn + Cr) molar ratio 1:5 and
Mn/Cr molar ratio from 1:3 to 1:4.
Abstract: This paper aims to study the effect of cold work
condition on the microstructure of Cu-1.5wt%Ti, and Cu-3.5wt%Ti
and hence mechanical properties. The samples under investigation
were machined, and solution heat treated. X-ray diffraction technique
is used to identify the different phases present after cold deformation
by compression and also different heat treatment and also measuring
the relative quantities of phases present. The metallographic
examination is used to study the microstructure of the samples. The
hardness measurements were used to indicate the change in
mechanical properties. The results are compared with the mechanical
properties obtained by previous workers. Experiments on cold
compression followed by aging of Cu-Ti alloys have indicated that
the most efficient hardening of the material results from continuous
precipitation of very fine particles within the matrix. These particles
were reported to be β`-type, Cu4Ti phase. The β`-β transformation
and particles coarsening within the matrix as well as long grain
boundaries were responsible for the overaging of Cu-1.5wt%Ti and
Cu-3.5wt%Ti alloys. It is well known that plate-like particles are β –
type, Cu3Ti phase. Discontinuous precipitation was found to start at
the grain boundaries and expand into grain interior. At the higher
aging temperature, a classic Widmanstätten morphology forms giving
rise to a coarse microstructure comprised of α and the equilibrium
phase β. Those results were confirmed by X-ray analysis, which
found that a few percent of Cu3Ti, β precipitates are formed during
aging at high temperature for long time for both Cu- Ti alloys (i.e.
Cu-1.5wt%Ti and Cu-3.5wt%Ti).
Abstract: Interstitial free steels possess better formability and
have many applications in automotive industries. Forming limit
diagrams (FLDs) indicate the formability of materials which can be
determined by experimental and finite element (FE) simulations.
FLDs were determined experimentally by LDH test, utilizing optical
strain measurement system for measuring the strains in different
width specimens and by FE simulations in Interstitial Free (IF) and
Interstitial Free High Strength (IFHS) steels. In this study, the
experimental and FE simulated FLDs are compared and also the
stress based FLDs were investigated.
Abstract: The Chair of Thermal Engineering at Poznan
University of Technology has been conducted research works on the
possibilities of using carbon nanostructures in energy and mechanics
applications for a couple of years. Those studies have provided results in a form of co-operation with foreign research centres, numerous publications and patent
applications.
Authors of this paper have studied the influence of multi-walled
carbon nanostructures on changes in static friction arising when steel
surfaces were moved. Tests were made using the original test stand
consisting of automatically controlled inclined plane driven by
precise stepper motors. Computer program created in the LabView
environment was responsible for monitoring of the stand operation,
accuracy of measurements and archiving the obtained results. Such a
solution enabled to obtain high accuracy and repeatability of all
conducted experiments.
Tests and analysis of the obtained results allowed us to determine
how additional layers of carbon nanostructures influenced on changes
of static friction coefficients. At the same time, we analyzed the
potential possibilities of applying nanostructures under consideration
in mechanics.
Abstract: Implementation of advanced technologies requires
sophisticated instruments that deal with the operation, control,
restoration and protection of rapidly growing power system network
under normal and abnormal conditions. Presently, the applications of
Phasor Measurement Unit (PMU) are widely found in real time
operation, monitoring, controlling and analysis of power system
network as it eliminates the various limitations of supervisory control
and data acquisition system (SCADA) conventionally used in power
system. The use of PMU data is very rapidly increasing its
importance for online and offline analysis. Wide area measurement
system (WAMS) is developed as new technology by use of multiple
PMUs in power system. The present paper proposes a model of
Matlab based PMU using Discrete Fourier Transform (DFT)
algorithm and evaluation of its operation under different
contingencies. In this paper, PMU based two bus system having
WAMS network is presented as a case study.
Abstract: Fibre cement plates, often used in construction,
generally are made using quartz as an inert material, cement as a
binder and cellulose as a fibre. This paper, first of all, investigates the
mechanical properties and durability of fibre cement plates when
quartz is both partly and fully replaced with diatomite. Diatomite
does not only have lower density compared to quartz but also has
high pozzolanic activity. The main objective of this paper is the
investigation of the effects of supplementary cementing materials
(SCMs) on the short and long term mechanical properties and
durability characteristics of fibre cement plates prepared using
diatomite. Supplementary cementing materials such as ground
granulated blast furnace slug (GGBS) and fly ash (FA) are used in
this study. Volume proportions of 10, 20, 30 and 40% of GGBS and
FA are used as partial replacement materials to cement. Short and
long term mechanical properties such as compressive and flexural
strengths as well as sorptivity characteristics and mass were
investigated. Consistency and setting time at each replacement levels
of SCMs were also recorded. The effects of using supplementary
cementing materials on the carbonation and sulphate resistance of
fibre cement plates were then experimented. The results, first of all,
show that the use of diatomite as a full or partial replacement to
quartz resulted in a systematic decrease in total mass of the fibre
cement plates. The reduction of mass was largely due to the lower
density and finer particle size of diatomite compared to quartz. The
use of diatomite did not only reduce the mass of these plates but also
increased the compressive strength significantly as a result of its high
pozzolanic activity. The replacement levels of both GGBS and FA
resulted in a systematic decrease in short term compressive strength
with increasing replacement levels. This was essentially expected as
the total rate of hydration is much lower in GGBS and FA than that
of cement. Long term results however, indicated that the compressive
strength of fibre cement plates prepared using both GGBS and FA
increases with time and hence the compressive strength of plates
prepared using SCMs is either equivalent or more than the
compressive strength of plates prepared using cement alone.
Durability characteristics of fibre cement plates prepared using SCMs
were enhanced significantly. Measurements of sopritivty
characteristics were also indicated that the plates prepared using
SCMs has much lower water absorption capacities compared to
plates prepared cement alone. Much higher resistance to carbonation
and sulphate attach were observed with plates prepared using SCMs.
The results presented in this paper show that the use of SCMs does
not only support the production of more sustainable construction
materials but also enhances the mechanical properties and durability
characteristics of fibre cement plates.
Abstract: This paper presents a new automatic vehicle detection
method from very high resolution aerial images to measure traffic
density. The proposed method starts by extracting road regions from
image using road vector data. Then, the road image is divided into
equal sections considering resolution of the images. Gradient vectors
of the road image are computed from edge map of the corresponding
image. Gradient vectors on the each boundary of the sections are
divided where the gradient vectors significantly change their
directions. Finally, number of vehicles in each section is carried out
by calculating the standard deviation of the gradient vectors in each
group and accepting the group as vehicle that has standard deviation
above predefined threshold value. The proposed method was tested in
four very high resolution aerial images acquired from Istanbul,
Turkey which illustrate roads and vehicles with diverse
characteristics. The results show the reliability of the proposed
method in detecting vehicles by producing 86% overall F1 accuracy
value.
Abstract: In the field of fashion design, 3D Mannequin is a kind
of assisting tool which could rapidly realize the design concepts.
While the concept of 3D Mannequin is applied to the computer added
fashion design, it will connect with the development and the
application of design platform and system. Thus, the situation
mentioned above revealed a truth that it is very critical to develop a
module of 3D Mannequin which would correspond with the necessity
of fashion design. This research proposes a concrete plan that
developing and constructing a system of 3D Mannequin with Kinect.
In the content, ergonomic measurements of objective human features
could be attained real-time through the implement with depth camera
of Kinect, and then the mesh morphing can be implemented through
transformed the locations of the control-points on the model by
inputting those ergonomic data to get an exclusive 3D mannequin
model. In the proposed methodology, after the scanned points from the
Kinect are revised for accuracy and smoothening, a complete human
feature would be reconstructed by the ICP algorithm with the method
of image processing. Also, the objective human feature could be
recognized to analyze and get real measurements. Furthermore, the
data of ergonomic measurements could be applied to shape morphing
for the division of 3D Mannequin reconstructed by feature curves. Due
to a standardized and customer-oriented 3D Mannequin would be
generated by the implement of subdivision, the research could be
applied to the fashion design or the presentation and display of 3D
virtual clothes. In order to examine the practicality of research
structure, a system of 3D Mannequin would be constructed with JAVA
program in this study. Through the revision of experiments the
practicability-contained research result would come out.
Abstract: In the present study, response surface methodology has been used to optimize turn-assisted deep cold rolling process of AISI 4140 steel. A regression model is developed to predict surface hardness and surface roughness using response surface methodology and central composite design. In the development of predictive model, deep cold rolling force, ball diameter, initial roughness of the workpiece, and number of tool passes are considered as model variables. The rolling force and the ball diameter are the significant factors on the surface hardness and ball diameter and numbers of tool passes are found to be significant for surface roughness. The predicted surface hardness and surface roughness values and the subsequent verification experiments under the optimal operating conditions confirmed the validity of the predicted model. The absolute average error between the experimental and predicted values at the optimal combination of parameter settings for surface hardness and surface roughness is calculated as 0.16% and 1.58% respectively. Using the optimal processing parameters, the surface hardness is improved from 225 to 306 HV, which resulted in an increase in the near surface hardness by about 36% and the surface roughness is improved from 4.84µm to 0.252 µm, which resulted in decrease in the surface roughness by about 95%. The depth of compression is found to be more than 300µm from the microstructure analysis and this is in correlation with the results obtained from the microhardness measurements. Taylor hobson talysurf tester, micro vickers hardness tester, optical microscopy and X-ray diffractometer are used to characterize the modified surface layer.
Abstract: We investigate experimentally and theoretically the
dynamics of a capacitive resonator under mixed frequency excitation
of two AC harmonic signals. The resonator is composed of a proof
mass suspended by two cantilever beams. Experimental
measurements are conducted using a laser Doppler Vibrometer to
reveal the interesting dynamics of the system when subjected to twosource
excitation. A nonlinear single-degree-of-freedom model is
used for the theoretical investigation. The results reveal combination
resonances of additive and subtractive type, which are shown to be
promising to increase the bandwidth of the resonator near primary
resonance frequency. Our results also demonstrate the ability to shift
the combination resonances to much lower or much higher frequency
ranges. We also demonstrate the dynamic pull-in instability under
mixed frequency excitation.
Abstract: Model transformation, as a pivotal aspect of Modeldriven
engineering, attracts more and more attentions both from
researchers and practitioners. Many domains (enterprise engineering,
software engineering, knowledge engineering, etc.) use model
transformation principles and practices to serve to their domain
specific problems; furthermore, model transformation could also be
used to fulfill the gap between different domains: by sharing and
exchanging knowledge. Since model transformation has been widely
used, there comes new requirement on it: effectively and efficiently
define the transformation process and reduce manual effort that
involved in. This paper presents an automatic model transformation
methodology based on semantic and syntactic comparisons, and
focuses particularly on granularity issue that existed in transformation
process. Comparing to the traditional model transformation
methodologies, this methodology serves to a general purpose: crossdomain
methodology. Semantic and syntactic checking
measurements are combined into a refined transformation process,
which solves the granularity issue. Moreover, semantic and syntactic
comparisons are supported by software tool; manual effort is replaced
in this way.
Abstract: The aim of this investigation is to elaborate nearinfrared
methods for testing and recognition of chemical components
and quality in “Pannon wheat” allied (i.e. true to variety or variety
identified) milling fractions as well as to develop spectroscopic
methods following the milling processes and evaluate the stability of
the milling technology by different types of milling products and
according to sampling times, respectively. These wheat categories
produced under industrial conditions where samples were collected
versus sampling time and maximum or minimum yields. The changes
of the main chemical components (such as starch, protein, lipid) and
physical properties of fractions (particle size) were analysed by
dispersive spectrophotometers using visible (VIS) and near-infrared
(NIR) regions of the electromagnetic radiation. Close correlation
were obtained between the data of spectroscopic measurement
techniques processed by various chemometric methods (e.g. principal
component analysis [PCA], cluster analysis [CA]) and operation
condition of milling technology. It is obvious that NIR methods are
able to detect the deviation of the yield parameters and differences of
the sampling times by a wide variety of fractions, respectively. NIR
technology can be used in the sensitive monitoring of milling
technology.
Abstract: This study addresses a concept of the Sustainable Building Environmental Model (SBEM) developed to optimize energy consumption in air conditioning and ventilation (ACV) systems without any deterioration of indoor environmental quality (IEQ). The SBEM incorporates two main components: an adaptive comfort temperature control module (ACT) and a new carbon dioxide demand control module (nDCV). These two modules take an innovative approach to maintain satisfaction of the Indoor Environmental Quality (IEQ) with optimum energy consumption; they provide a rational basis of effective control. A total of 2133 sets of measurement data of indoor air temperature (Ta), relative humidity (Rh) and carbon dioxide concentration (CO2) were conducted in some Hong Kong offices to investigate the potential of integrating the SBEM. A simulation was used to evaluate the dynamic performance of the energy and air conditioning system with the integration of the SBEM in an air-conditioned building. It allows us make a clear picture of the control strategies and performed any pre-tuned of controllers before utilized in real systems. With the integration of SBEM, it was able to save up to 12.3% in simulation of overall electricity consumption, and maintain the average carbon dioxide concentration within 1000ppm and occupant dissatisfaction in 20%.
Abstract: Surf is an increasingly popular sport and its performance evaluation is often qualitative. This work aims at using a smartphone to collect and analyze the GPS and inertial sensors data in order to obtain quantitative metrics of the surfing performance. Two approaches are compared for detection of wave rides, computing the number of waves rode in a surfing session, the starting time of each wave and its duration. The first approach is based on computing the velocity from the Global Positioning System (GPS) signal and finding the velocity thresholds that allow identifying the start and end of each wave ride. The second approach adds information from the Inertial Measurement Unit (IMU) of the smartphone, to the velocity thresholds obtained from the GPS unit, to determine the start and end of each wave ride. The two methods were evaluated using GPS and IMU data from two surfing sessions and validated with similar metrics extracted from video data collected from the beach. The second method, combining GPS and IMU data, was found to be more accurate in determining the number of waves, start time and duration. This paper shows that it is feasible to use smartphones for quantification of performance metrics during surfing. In particular, detection of the waves rode and their duration can be accurately determined using the smartphone GPS and IMU.