ELEKTRONIKA, ENERGETYKA, ELEKTROTECHNIKA ›
ELEKTRONIKA - KONSTRUKCJE, TECHNOLOGIE, ZASTOSOWANIA ›
2012-1 |
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Publikacja: LTCC microfluidic chip with fluorescence based detection
Autor: Mateusz Czok  Karol Malecha Leszek Golonka
Nowadays miniaturization is present in many fields of science (electronics,
medicine, biology and chemistry). Over the last few years
many research into miniaturization and microfabrication were carried
out. As a result the concepts of the micro-total analysis system (μTAS)
and Lab-on-Chip (LoC) were proposed. These devices integrate several
laboratory functionalities in a single miniature structure [1, 2].
There are few technologies that can be applied in the realization of
the LoC devices. For many years the most common used materials
were silicon and glass wafers [3, 4]. As an alternative solution few
other materials like PDMS (poly(dimethylsiloxane)) or PCB (Printed
Circuit Boards) were used for microsystems fabrication [5, 6].
The Low Temperature Co-fired Ceramics (LTCC) seems to be
a suitable material to realize LoC devices. Channels, chambers,
valves, electronic and optoelectronic components can be easily
integrated in one LTCC module [7, 8]. It also has outstanding physical
and chemical properties [9].
The main motivation is to use the LTCC technology in the fabrication
of the microfluidic chip, in which fluorescence detection of
biological sample can be performed. The manufactured detection
module consists of inexpensive and commonly available electronic
components and PMMA (poly(methyl methacrylate)) optic
fibres integrated with the LTCC microfluidic chip. It is made up of
the microfluidic channel, cavities for fiber optics, miniature light
emitting diode and photodetector.
The LTCC microfluidic chip performance is investigated with
several different concentrations of fluorescein solutions which
are excited with 465 n[...]
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Prenumerata
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A compact thermoelectric harvester for waste heat conversion
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Piotr Dziurdzia Karol Lichota
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Ambient energy harvesters have been playing more and more important
role in the electronic industry in recent years. Not so long ago,
energy scavenging was treated in R & D laboratories with some timidity
and used only in some niche applications. Nowadays, development
of autonomous power sources for supplying microelectronic systems
is strongly driven by market demands following recent advances in
smart mobile equipment, wireless sensor networks (WSN), monitoring
of industrial processes, etc. Since transmission lines have been
replaced with wireless channels a long time ago, now the energy harvesters
are removing the last obstacle on the way to developing quite
autonomous electronic systems. By providing electrical voltage to the
sensor nodes from harvested pieces of ambient energy (for instance:
heat, light and vibrations) they do not need external sources of energy,
for instance power mains or batteries, any more [1-3].
For the last few years our team has been focused on developing
of thermoelectric energy harvesters for supplying wireless sensor
nodes. At the beginning, basing on the phenomena of Seebeck,
Peltier, Joule and Thomson, an original model of thermoelectric
generator was elaborated [4]. It was next subjected to simulations
in order to investigate the maximum ratings of TEG against available
heat power sources and different ambient conditions. In the
next steps first prototypes of TEGs were designed and fabricated.
Thermoelectric harvester
As a rule, thermoelectric generators suffer from relatively low conversion
efficiency (not exceeding 10%), so they are practically not
applicable to large-scale systems, not to mention power stations.
On the other hand they seem to be promising solu[...]
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Aktywne anteny radarów wielofunkcyjnych - analiza stanu i perspektywy rozwoju - część 1
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Edward Sędek
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W ostatnich latach obserwuje się rozwój radarów wielofunkcyjnych
z aktywnymi antenami ścianowymi, który stał się możliwy
dzięki dynamicznemu postępowi zarówno w zakresie nowych
materiałów mikrofalowych, jak i monolitycznych układów scalonych
(MIMIC) [1-7]. Ogólnie można stwierdzić, że postęp w zakresie
nowych materiałów, w szczególności półprzewodnikowych,
umożliwił opracowanie anten aktywnych, co w przeszłości było
praktycznie niemożliwe pomimo istniejących wtedy koncepcji rozwiązań
tego typu urządzeń. Próbowano wówczas wykorzystywać
technologie lampowe (LFB), ale ich nadmiernie wysoki koszt i gabaryty
odstraszały przyszłych użytkowników wojskowych. Współczesna
aktywna antena radiolokacyjna stanowi macierzowy szyk
elementów promieniujących zasilanych energią elektromagnetyczną
za pomocą modułów nadawczo-odbiorczych (T/R) sterowanych
poprzez mikrofalowe, cyfrowe przesuwniki fazy. Technika
ta pozwala na elektroniczne skanowanie przestrzeni wiązką antenową,
w ogólności zarówno w płaszczyźnie elewacji jak i azymutu.
Pełną możliwość oddziaływania na kształt wiązki uzyskuje
się wtedy, gdy w każdym elemencie promieniującym zastosuje
się przesuwnik fazy i układ regulujący amplitudę. Wówczas można
dynamicznie, w razie potrzeby, regulować jej kształt w czasie
rzeczywistym, tzn. jej szerokość zarówno w azymucie, jak i w elewacji
[8-10]. Możliwość ta jest niezmiernie przydatna w przypadku
śledzenia obiektów powietrznych, takich jak samoloty bojowe,
wystrzeliwane rakiety oraz rakiety balistyczne. Rozwój radiolokacji
wymusza coraz większe wymagania stawiane antenom i systemom
antenowym stosowanym w nowoczesnych radarach.
Coraz większy nacisk kładzie sie na ich integrację i wielofunkcyjność.
Wymaga się jednocześnie zachowania parametrów elektrycznych
na poziomie porównywalnym do parametrów anten stosowanych
w systemach jednofunkcyjnych. Szybki postęp technologiczny
pozwala współczesnym radarom realizować jednocześnie wiele
funkcji, takich[...]
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An investigation of the quality of the conductive lines deposited by inkjet printing on different substrates
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Janusz Sitek Konrad Futera Darko Belavič Marina Santo Zarnik Marek Kościelski Krystyna Bukat Kamil Janeczek Danjela Kuščer Hrovatin Małgorzata Jakubowska
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A lot of telecommunications, medical, industrial automation
and measurement equipment, as well as sensor applications,
are currently in the process of miniaturizing their dimensions.
The reliability requirements of electronic equipment and devices
is also constantly on the rise. One of the miniaturization
solutions is thick-film technology and 3D structures [1].
Such devices require conductive lines to connect the different
layers of simply manufactured devices. The fabrication of reliable,
very narrow, conductive lines for thick-film and other
structures is a crucial issue in the production of electronic
components. Inkjet printing is a technology that could be ap-
An investigation of the quality of the conductive lines
deposited by inkjet printing on different substrates
(Badanie jakości ścieżek przewodzących wytworzonych metodą druku
strumieniowego na różnych podłożach)
Ph.D Janusz Sitek 1), M.Sc.Eng. Konrad Futera 1,5), Darko Belavič 2,3,4), Ph.D Marina Santo Zarnik 2,3,4), M.Sc.Eng. Marek Kościelski 1), Ph.D Krystyna Bukat 1), M.Sc. Kamil Janeczek 1), Ph.D Danjela Kuščer Hrovatin 2,4), D.Sc.Eng. Małgorzata Jakubowska 5,6)
1) Tele- and Radio Research Institute, Centre of Advance Technology, Warsaw, 2) Jozef Stefan Institute, Ljubljana, Slovenia
3) HIPOT-RR, Otočec, Slovenia, 4) Centre of Excellence NAMASTE, Ljubljana, Slovenia
5) Warsaw University of Technology, Faculty of Mechatronics, 6) Institute of Electronic Materials Technology, Warsaw
plied for t[...]
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Analysis of electromagnetic couplingsin hybrid circuit made on austenitic metal substrate
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Wiesław SABAT Dariusz KLEPACKI Kazimierz KAMUDA
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The fast progress in material technology, new compositions of
dielectric inks allowed to realizations of hybrid structures on
metal substrates. The technological materials from DuPont,
ESL or Heraeus make possible to print different pastes on substrates
from rustless steel (austenitic, ferritic), aluminium or platinum.
The elaborated technological applications (in the most
cases) allow to realization of heating elements (HOS - Heaters
on Steel), electronic structures (COS - Circuits on Steel, TFOS
- Thick Film on Steel) as well as sensors structures for special
applications.
There are a lot of dielectric inks especially dedicated for those
applications. For example - 3500N for ferritic steels S430 and
S444 from DuPont, 4916 for austenitic steel S304 and 4924 for
ferritic steel S430 from ESL or SD1000 SD2000 for ferritic steel
S430 and IP211 dedicated to sensor applications and steels S430
or S446 from Heraeus.
This growing interest of the above-mentioned applications leads
to necessity of research in EMC area. The good knowledge
about mechanisms of disturbance propagation processes is the
basis of good designed final product.
Parasitic elements of paths’ system
The application of rustless steel, aluminium or platinum as substrate
material in microelectronic hybrid circuits leads to creation
of typical microstrip structure for path-substrate system
(Fig. 1) [1, 2].
62 Elektronika 1/2012
In the above-mentioned configuration the nearness of each
path in relation to ground (determined by thickness of the dielectric
paste) is cause of shorting effect of electric field lines to the
conducted structure of substrate. This effect leads to decrease of
electrical flux value in neighboring paths - then the small values
of parasitic capacitances are observed [2].
The three types of test circuits with different geometrical configuration
were made for realization of experimental investigations
(determination of per-unit-length para[...]
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Analysis of long-term stability of thin-film and polymer thick-film resistors embedded in Printed Circuit Boards
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Paweł Winiarski Andrzej Dziedzic Adam Kłossowicz Wojciech Stęplewski Grażyna Kozioł
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Embedded passives play a major role in miniaturisation of electronic
circuits, where e.g. MCM or HDI technologies [1] can be
used. In most cases resistors represent the majority of passive
components used on a circuit board. Besides size aspects, there
are other very important issues like tolerance, reliability and
long-term stability of components, especially in specialized applications.
Technology and production processes are extensively
studied and improved. However, to determine real reliability of
fabricated components proper measuring methods are needed.
To analyze stability of the resistors an accelerated ageing process
can be used. Treating resistors with elevated temperature
(or/and humidity) allows (in quite short time) obtain long-term behaviour
of tested samples referred to a few years of service [2].
Test structures
The thin-film resistors were fabricated on FR-4 laminate in accordance
with Ohmega-Ply® techno-logy [3, 4]. In this technique firstly
thin layer of Nickel-Phosphorous alloy is electroplated on copper
foil, afterwards this composite foil called RCM (resistor-conductor
material) is laminated to FR-4 substrate. Finally copper circuitry and
planar resistors are realized by subtractive processes. Two types
of resistive foil were used for fabrication of structures with sheet
resistance 25 Ω/sq and 100 Ω/sq (with thickness 0.4 μm and 0.1 μm
respectively). The rectangular resistors, with width from 0.25 mm to
1.5 mm and aspect ratio n=l/w between 1 and 4, were designed and
fabricated. Moreover, to investigate embedded resistors, part of the
samples was covered with two types of cladding - Resin Coated
Copper (RCC) or Laser Drillable Prepreg (LDP) 2 × 106. The cladding
gives additional protection from environ-mental conditions.
The PTF resistors were made using a standard thick-film
method [5]. To fabricate resistors three types of resistive inks were
used, with sheet resistance 20 ][...]
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Analysis of pulse durability of thin-film and polymer thick-film resistors embedded in printed circuit boards
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Adam Kłossowicz Andrzej Dziedzic Paweł Winiarski Wojciech Stęplewski Grażyna Kozioł
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Traditional passives are three-dimensional discrete components,
soldered through or onto surface. They occupy significant part of
top/bottom surface (up to 50% of the surface area) and increase
thickness and weight of electronic circuits/systems. The embedded
passives (resistors, capacitors and/or inductors - Fig. 1) are
more and more used in multichip module (MCM) technologies.
They are fabricated among others in Low Temperature Co-fired
Ceramics (LTCC) substrates or PCBs. The embedded passives in
comparison to traditional ones are essentially two-dimensional elements
that become part of the internal layers of a PCB or LTCC
substrate increasing its thickness only of around several μm.
Shifting of passives into substrate can increase a free space of
PCB for active components and improve packaging density. The
embedded passive technology (EPT) is incited by many factors
such as the need for higher packaging density, lower production
costs and better electrical properties.
EPT permits for distance reduction between components
(which leads to reduction of parasitics, less crosstalk and enhance
transmission quality) and improving of electrical performance
especially in higher frequencies (because of lower loss and lower
noise yield). One should note, that EPT can also simplify the assembly
process and reduce assembly cost (for example embedded
passives has not problem with positioning). By using embedded
passives we can lower material cost by reducing the number
of discrete passives, flux, and solder paste. Nowadays technology
allows to embedding both thick-film and thin-film resistors.
Pulse durability is an important parameter of passive components
and active devices. In general, the susceptibility to high
voltage pulses and electrostatic discharges has been investigated
for thin- and thick-film resistors for more than 30 years [1, 2].
Such investigations can be performed with the aid of single or
series of "long" pulses ([...]
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Design and realization of a microfluidic capillary sensor based on a silicon structure and disposable optrodes
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Zbigniew Szczepański Michał Borecki Dariusz Szmigiel Michael L. Korwin Pawlowski
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During the last years microfluidic sensors that use optical capillaries
have gained an increasing importance due to their new
applications as diagnostic tool in biotechnology, medicine and in
environmental sciences. This was possible because the capillary
enables multiparametric sensing [1-7] contrary to the classical
optical fiber sensors [8], which find applications in physical measurements
such as pressure and also magnetic field [9].
In this paper the improvements in the design of microfluidic
sensors that use local heating in optical capillaries as a base
of multiparametric diagnostics is presented [4]. The application
of local heating opened interesting new possibilities for the
sensors, that do not use any chemical sensitive layers or reagents,
while raising specific issues relating to their construction,
materials and technology [5]. The mentioned sensors can be
used for in situ diagnostic in medicine and veterinary and as
biofuel usability testers [10-12].The proposed microfluidic capillary
sensor consists of a stabilized-intensity light source unit,
a testing head with replaceable optical capillary, a heater and
a detection unit. The optical capillary performs the functions of
a liquid sample holder and at the same time of a multiparametric
sensing element. The sensor operates in a multiparametric sensing
mode, monitoring, registering and processing the indirect
information such as the index of refraction, the boiling point,
the vapour pressure, the heat capacity, the heat of fusion, the
viscosity, the surface tension of the liquid and turbidity changes
in a thermally forced measuring cycle. The measuring cycle is
initiated by applying local heating to the sample [5]. The measuring
cycle is controlled indirectly by changes in optical signals
and temperatures [10]. The raw optical data are processed
by an optoelectronic ci[...]
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Device for road holes and obstacles detection
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Wojciech Gelmuda Andrzej Kos
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Today’s life as we know it is based on visual signs. Practically all
the important information needed to go independently through an
average person’s day is provided by their sight. Let us focus on
some urban environment. A person is able to see objects, determine
their approximate distance, distinguish between a hole and
a bump on a road, detect and recognize an important element
from its background or simply read some text information from
books, posters, etc. Most of these actions, if not all, allow people
to gather information and give them time to react before they approach
some objects. Furthermore, there are many devices that
help people gain more important for them information than they
would be able to learn from a closest environment in their field of
view, such as navigation systems. There are also many devices
that help people keep safe and avoid some accidents, like for
instance, street lights and road signs. But neither of them is well
suited for visually impaired people. Of course, there are special
audio signals for blind people near some pedestrian crossings
and there are devices which help visual impaired people avoid
obstacles [1], but they are still not sufficient to keep them safe
and well informed about their surrounding environment [2]. This
is mostly due to a change of sensors positions while a blind
person is moving. That is why we develop a MOBIAN© project
- Mobile Safety System for the Blind [3]. This project is supported
by The National Centre for Research and Development
under: NR13-0065-10. A part of the MOBIAN© project is to create
a highly reliable device for detecting obstacles and holes
of various length and depth, as it is presented in Fig. 1. There
is no doubt that special algorithms have to be designed, tested
and implemented for this purpose.
Fig. 1. Holes and other obstacle detection
Rys. 1. Wykrywanie dziur, usk[...]
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Dynamic research of foot pressure distribution - the four-points shoe insert with PVDF sensors
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Ewa Klimiec Wiesław Zaraska Szymon Kuczyński
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The human foot structure majorly decides about his/her movement
possibilities. Correctly constructed foot is arched on internal
side. The weight is distributed in a way, that medial arch acts like
a shock absorber, by softening shocks caused by walking. Correctness
of the foot structure can be estimate, by examining foot
pressure distribution on the ground. Faulty posture manifest itself
by different than correct, foot pressure distribution on the ground.
Currently there are two measuring systems on the market, allowing
diagnosis. It is EMed-SF [1, 2] and PEDAR - System [3,
4]. In the first one, examined person crosses through the track,
placing third step on the measuring platform. Contact with the
platform surface should be measured in a natural way so, that
there was no measuring distortion by aware step shortening or
lengthening. For this purpose, several trials heve to be done and
starter has to be suitably set up. Obtained results are in the form
of map which shows the pressure distribution on foot contact surface
with measuring platform in N/cm2. The example of recorded
pressure distribution for healthy foot structure is shown on Fig.1.
ted: under the heel, medial arch, mid-foot and hallux. Films were
glued together. The view of the four-points measuring shoe insert
is shown on Fig. 2.
Fig. 1. Pressure distribution of healthy foot to the ground recorded
by EMed-SF system
Rys. 1. Rozkład nacisku prawidłowo zbudowanej stopy na podłoże,
zarejestrowany przez EMed-SF system
Data presented on Fig. 1 shows that for healthy foot, the biggest
values of the pressure are observe under heel, midfoot and
on hallux. Measuring system PEDAR is characterized by the fact
that we examine the foot pressure between foot and shoe sole.
The pressure is recorded by pressure sensors which are installed
into shoe insole. The system is expensive and shoe insole very
thick. It will be profitable to develop competitive system which will
be able t[...]
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Electrocatalytic sensor based on Nasicon with auxiliary layer
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Anna Strzelczyk Grzegorz Jasiński Piotr Jasiński Bogdan Chachulski
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In recent years electrochemical gas sensors based on solid state
electrolytes have been intensively investigated. They are relatively
easy to fabricate, simple in use and quite durable. Nasicon
(Na Super Ionic Conductor) is one of the most promising
materials, which have been used in construction of gas sensors.
Sensors based on Nasicon are used for detecting of different
gases including carbon oxides [1, 2], nitrogen oxides [3-6] and
sulfur dioxide [7]. Most of these devices operate in potentiometric
or amperometric mode.
In case of some sensor constructions, besides electrolyte and
metal electrodes, additional layers are applied. In some cases such
phase is required to obtain sensitivity to specific gas or to shift operating
temperature to more preferred one [7]. In other cases sensor
properties such as selectivity or stability are improved. Auxiliary
phase usually forms extra interface between measured gaseous
compound and electrolyte or electrodes. For example, in case of
amperometric sensors, it was noticed, that presence of auxiliary
layer on surface of sensing electrode can increase the number of reaction
sites thus improving sensor sensitivity [5]. Auxiliary layer may
also be used to create a diffusion barrier. In case of the potentiometric
or amperometric nitrogen oxides sensors based[...]
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Electronic measurement system for monitoring of geometrical parameters of rolling shaped metal profiles
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Snezhinka Zaharieva Valentin Mutkov Ivan Georgiev
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The measurement of the complex and the differential geometric
parameters in the production process of cylindrical, square and
rectangular rolling shaped metal profiles will undoubtedly lead to
a rise in the production quality.
The dynamics of the technological process and the influence
of great number of outside factors on geometrical parameters of
revolving, enforce development of an electronic measurement
system, which may reliably reads and preserves measured data
immediately in the production process of rolling shaped metal [1,
5].
Adopting a microprocessor technique in measuring systems
gives an opportunity for а program processing of information and
retroaction towards the technological process. Thus measuring
systems will come up оn a new high quality level, their measurement
capacities will be expanded, the measurement regime
will be chosen automatically, the immediate measurement results
will be stored and the necessary calculations will be made. This
will allow the removal of subjective and objective factors affecting
measurement accuracy.
The accomplished electronic measurement system for monitoring
of geometric parameters of rolling shaped metal performs
an active firsthand control in the production process, for the purpose
of management of the quality of the finished production.
The paper is organized as follows. First, the block diagram
of electronic measurement system for monitoring of geometrical
parameters of rolling shaped metal is presented. Second, the principle
electrical scheme of the system is described. Finally, the results
of the work of the experimental setting are presented as well
as the main results obtained by the authors are summarized.
Block diagram of electronic measurement
system for monitoring of geometrical
parameters of rolling shaped metal
A block diagram, shown in Figure 1, contains nine information
channels, eight of which are identical and carry the information
from eigh[...]
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EMC Aspects in microelectronics structures made in LTCC technology
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Wiesław SABAT Dariusz KLEPACKI Włodzimierz KALITA
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The fast development of LTCC technology (Low Temeperature
Cofired Ceramic) is observed in relation to realization of multilayered
hybrid structures. It is applied for manufacturing of wide
range of microelectronic circuits, especially MCM-C structures
(Multi Chip Module on Ceramics) which are used in different
areas of industry. The multilayered structures, sensors, microsystems,
passive elements, microwave elements can be found in
telecommunication, informatics, radioengineering, mechatronics,
transport, etc. The possibility of creation of channels and cavities
inside of LTCC module allows to realization of chemical microreactors,
hydraulic systems in microscale (together with pumps and
valves), fuel cells, flat plasma displays, sensors of physical quantities
and systems applied in biotechnology and medicine [1, 2].
Parasitic elements of paths’ system
The calculations of mutual capacitance CM and effective inductance
Lz (for two parallel paths system with parametrically changed
the mutual distance "s" and paths width "w") were made using
elaborated PACAPIND program. They allowed to determine range
of parameters changes of parasitic elements in typical LTCC
structure for three basic configurations.
For experimental investigations (determination of per-unitlength
parameters) the test circuits were made in configuration
of mutual parallel path systems (Fig. 1) on the basis of silver
conductive paste HF612Ag and LTCC substrate 943PX from
DuPont.
The test circuits were made in three configurations: onelayered,
two-layered with ground plane (microstrip configurations)
and layered with the same thickness of subs[...]
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GENESI: Wireless Sensor Networks for structural monitoring
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Brendan O’Flynn David Boyle E. Popovici Michele Magno C. Petrioli
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The GENESI project has the ambitious goal of bringing WSN technology
to the level where it can provide the core of the next generation
of systems for structural health monitoring that are long
lasting, pervasive and totally distributed and autonomous. Sensor
nodes are being redesigned to overcome their current limitations,
especially concerning energy storage and provisioning (we need
devices with virtually infinite lifetime) and resilience to faults and interferences
(for reliability and robustness). New software and protocols
will be defined to fully take advantage of the new hardware,
providing new paradigms for cross-layer interaction at all layers of
the protocol stack and satisfying the requirements of a new concept
of Quality of Service (QoS) that is application-driven, truly reflecting
the end user perspective and expectations. The GENESI system
will be deployed in two pilot deployments; namely the monitoring of
a bridge (Pont de la Poya, Switzerland) and a metro tunnel (Metropolitana
Linea B, Rome), both during and after construction.
System requirement analysis
GENESI (Green sEnsor NEtworks for Structural monItoring) [1]
exhibits a range of system requirements from a variety of established
and emerging technical scientific disciplines.
The systems are required to be “Green" and Sustainable - The
use of energy scavanging techniques (i.e. harnessing available
environmental energy) to extend the lifetime of GENESI nodes
will be employed. Realistic potential sources include solar and
wind energy. A fuel cell or series of fuel cells, capable of providing
significant amounts of energy, will also be integrated in the design
of a novel power unit. This unit may also make use of integrated
suitable battery cell(s) and/or other storage techniques (such as
capacitors). It should provide sufficient energy to power the GENESI
wireless sensor nodes for extended periods of time.
In addition to developing novel hardware to add[...]
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High temperature properties of thick-film and LTCC components
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Damian Nowak Mateusz Janiak Andrzej Dziedzic Tomasz Piasecki
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There is an increased demand for electronics that can work in
harsh environment involving high temperature. Applications include
sensors and actuators for control in petroleum and geothermal
industry, process monitoring and distributed control systems in
automotive and aerospace [1-3]. Complete extreme high-temperature
electronic systems require active devices as well as proper
passive components (eg. resistors, capacitors, inductors).
There comes also the requirement for further miniaturization and
integration of electronic components. Thick-film and LTCC (low
temperature co-fired ceramics) technologies are well-established
and relatively low-cost fabrication method of passives. Thus, they
represent promising fabrication techniques to meet the demands
for devices that are miniaturized and operate at high temperature
[4-7]. This paper presents manufacturing process of thick-film
and LTCC resistors, planar inductors and interdigital capacitors
as well as their chosen electrical and stability properties in a wide
frequency and temperature range.
Test structures fabrication
Square planar inductors and interdigital capacitors were made on
alumina (96% Al2O3, 635 μm thick) or fired LTCC (DP951, 300
μm thick) substrates. The size of the fabricated components was
3×3 mm2 and 50 μm track width/50 μm spacing were designed.
The inductors consist of 2 or 3 tu[...]
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Impact of non-optimal grounding of the CC2420 RFIC on a 802.15.4 Tyndall sensor wireless mote
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Peter Haigh John Buckley Brendan O'Flynn Cían Ó'Mathúna
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Range, throughput and power consumption are important issues
in 802.15.4 [1] Wireless Sensor Networks. While the focus is
often on increased power output (at the expense of dc power)
and sensitivity to address these issues, little attention is given
to waveform quality. Poor waveform quality often measured in
terms of EVM can lead to increased packet errors, transmission
retries and therefore reduced range and throughput leading to
increased power consumption. One important factor in relation to
this is proper grounding of the RF devices. This paper describes
an investigation into these effects that was triggered when poor
throughput was reported from the system integrators.
Measurement Technique
As the modulated signal passes through a non-linear function it
becomes distorted. This distortion leads to a degradation in the
signal quality and ultimately affects the throughput of the system
due to an increase in Bit Error Rate (BER) leads to re-transmissions.
The relationship between linearity, Adjacent Channel Power
Ratio (ACPR) and EVM is well established [2, 3]. Of particular
interest in this study was the effect of non-optimal grounding of
the radio transceiver on output spectrum and EVM. Test methods
were devised to measure these parameters based on the existing
802.15.4 standard.
Adjacent Channel Power Ratio
The incumbent radio standard defines some parameters for signal
quality and ACPR. These are defined to ensure that the wireless
system will perform to specification taking into account regulatory
as well as inter and intra system issues. For ACPR it was found
that the definition in 802.15.4 was not sensitive enough for this
investigation. Therefore, a new measurement was defined to enable
the analysis of more detailed linearity effects.
A typical 802.15.4 spectra such as in Fig. 1, exhibits well defined
troughs that are defined by the channel filter characteristic.
From experimentation, it was shown that the spectral[...]
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Impedance spectroscopy as a diagnostic tool of degradation of Solid Oxide Fuel Cells
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Konrad Dunst Sebastian Molin Piotr Jasiński
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Solid oxide fuel cell (SOFC) is an electrochemical device that converts
chemical potential energy directly into electrical power. In
comparison with a traditional combustion process, the SOFCs offer
greater efficiency, reliability and environmental friendliness [1].
The SOFCs have a great potential to generate power from a wide
range of fuels: hydrogen, carbon monoxide, hydrocarbons and
alcohols. However, when operated, the fuel cells usually degrade.
The nature of this process depends on the type of the applied
fuel and materials used to fabricate the SOFC. In particular, when
hydrocarbons are used as a fuel, a carbon can deposit inside the
anode structure [2]. The deposited carbon may cause a complete
degradation of the fuel cell.
Further development of the SOFCs requires investigation of
degradation process during fuel cells operation. Among the fuel
cell diagnostic tools, AC impedance spectroscopy is a powerful
technique [3]. This method allows obtaining information about different
electrode processes, namely, oxygen reduction reaction
kinetics, mass transfer and electrolyte resistance losses [4]. Selection
of the appropriate experimental conditions (temperature,
pressure and flow rate) may provide information extracted from
the impedance spectra about the performance losses from the
each fuel cell element separately [3,5].
Different electrode processes reveal unique characteristic
frequencies, which depend on cell structure, materials used for
SOFC fabrication and testing conditions. For example, in case of
the anode supported cells with LSM ((La0.75Sr0.25)0.95 MnO3) cathode
operated at 750°C it was found [6], that the characteristic freque[...]
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Inteligentny handel
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Jedna z firm wysyłkowych w Polsce, należąca również do grupy
największych sklepów internetowych, rozpoczęła korzystanie
z rozwiązań "Inteligentnego handlu" opracowanych przez IBM.
Wdrożenie to umożliwiło firmir zwiększenie efektywności i wzrost
sprzedaży.
Okres świąteczny to dla firmy wysyłkowej czas wzmożonej
aktywności. Firma specjalizuje się w sprzedaży książek, filmów
i muzyki, dekoracji, upominków a także zabawek, dlatego zwykle
w grudniu przyjmuje najwięcej zamówień. Z myślą o pozyskaniu
jeszcze większej liczby klientów, firma zdecydowała się
na wdrożenie w swoim sklepie internetowym rozwiązań IBM
Cor[...]
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Investigation of multiple degradation and rejuvenation cycles of electroluminescent thick film structures
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MATEUSZ MROCZKOWSKI MICHAŁ CIEŻ JERZY KALENIK
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Copper doped zinc sulfide displays electroluminescent prosperities
and it is used as a phosphor in thick film light emitting structures.
Such electroluminescent structures, or alternating current
electroluminescent devices (ACEL), are used as backlight for
liquid crystal displays in portable electronic devices (cell phones,
notebooks, PDAs, etc.) and as a source of light in the advertising
industry. Unfortunately such structures are prone to degradation
and have a limited life time [1, 2].
Degraded electroluminescent thick film structures can be
rejuvenated by annealing [1]. An attempt to investigate the possibility
of repeated rejuvenation of degraded EL lamps was undertaken.
The goal of this investigation is to better understand
the mechanism of degradation and rejuvenation of thick film EL
lamps and prolong their life time.
Alternating Current Electroluminescent
Devices (ACEL)
Typical EL lamps are fabricated as a multi-layer thick film structures.
A layer of phosphor, for examp[...]
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Investigations of passive components embedded in printed circuit boards
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Wojciech Stęplewski Tomasz Serzysko Grażyna Kozioł Kamil Janeczek Andrzej Dziedzic
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The concept of passive components embedded between inner
layers of printed circuit board (PCB) was introduced many
years ago. The first trials of embedded capacitors started at
the end of sixties of the last century [1]. In the beginning of seventies
started the applying of NiP layers for manufacturing of
thin layer resistors [2]. Up to present day many materials which
can be used for embedded passives were elaborated. But this
technology is used in small range, especially in military and air
electronics as well as in space electronics. Due to the increasing
number of components which are now required to support
a single active device, the passives are quickly becoming the
major bottleneck in the general miniaturization trend which has
become so important in today’s electronics world. The miniaturization
of conventional passives reaches its limits and the
next obvious choice is to embed the passive components into
the PCB. This allows further miniaturization, has the potential
to reduce cost and moreover exhibits superior electrical behavior
with respect to the minimization of parasitic effects [3, 4].
Despite unquestionable advantages which characterize the embedded
elements, they are not generally used in the production
of PCBs. As well the designing of electronic devices such as
filters, generators, RFID systems and many others, which are
composed of passive components, was not to this time used
on larger scale and knowledge in this matter is still very poor.
Embedding passives will permit to integrate these elements
and whole structures into the PCB. The idea of packing more
and more elements in PCBs by application and development
of embedding passives technologies becomes a necessity for
electronic equipment producers.
Materials and structures
Thin-film resistors
In the investigations two types of materials with sheet resistance
of 25 Ω/□ (thickness 0.4 μm) and 100 Ω/□ (thickness 0.1 	[...]
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Mechanical and thermal properties of SiC - ceramics substrate interface
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Ryszard Kisiel ZBIGNIEW Szczepański Piotr Firek MAREK Guziewicz ARKADIUSZ Krajewski
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Silicon carbide created new possibilities for high power and high
temperature electronics due to its unusual physical properties,
which are not attainable in conventional silicon semiconductor
material. It has been demonstrated that SiC based power devices
are able to operate at temperatures as high as 450°C [1, 2]. To realize
the high temperature functions of SiC power devices, the development
of high temperature packaging technologies becomes
more and more important. Packaging technologies play main role
in high power and high temperature electronics since they have
an essential effect for the reliability of SiC power devices [8, 9].
One of the main problems of high power package is die bonding
technology, which ought to assure not only mechanically reliable
connection between SiC die and substrate, but also good electrical
conductivity and high thermal conductivity. The latter feature is
especially critical for power devices because it allows for effective
heat transfer from power chip to the package.
State-of-the-art technologies for interconnecting Si power devices
involve attaching one terminal of the semiconductor die to
a heat-sinking substrate with solder alloy or with an electrically
conductive adhesive, while the other terminals are bonded by
aluminum or gold wires as well as flip chip technology. Such interconnection
technologies have several limitations in high-temperature
operation because solder alloys/conductive adhesives
usually have low melting/degradation temperatures. By changing
substrate material is possible to increase heat dissipation. So, the
package with DBC substrate is very good solution for high power
application, since such package significantly improves heat dissipation
and therefore is widely used in high power SiC modules.
Investigations of new techniques are necessary for high temperature
and high power SiC devices.
Taking into account mentioned above requirements, only a few
of the known die[...]
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Mechanoakustyczny czujnik aktywności układu sercowo-naczyniowego
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Jarosław Lewandowski Łukasz Dziuda Krzysztof Celiński-Spodar
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Pomimo rozwoju wielu metod diagnostyki stanu zdrowia wciąż
niezmiernie ważne i powszechnie stosowane jest osłuchiwanie
ciała w celu zbadania aktywności serca za pomocą stetoskopu.
Stetoskop jest nieodzownym, używanym w diagnostyce
kardiologicznej narzędziem wykorzystywanym podczas
badania fizykalnego. Pomimo postępu technicznego jaki dokonał
się w diagnostyce, konstrukcja stetoskopu praktycznie
nie uległa zmianom. Stetoskop był również użyty przez autorów
jako element pomiarowy, określający sygnał referencyjny
dla stanowisk pomiarowych, wyposażonych w czujniki służące
do bezkontaktowego monitorowania parametrów psychofizjologicznych,
opracowywanych w ramach projektu "Bezkontaktowe
metody pomiaru sygnałów psychofizjologicznych z funkcją automatycznego
wykrywania zagrożeń" [1] - Program Operacyjny
Innowacyjna Gospodarka - realizowanego przez autorów
z Wojskowego Instytutu Medycyny Lotniczej. Czujniki te służą
do monitorowania aktywności serca i aktywności oddechowej.
W przykładowym rozwiązaniu rolę czujnika pełni poduszka
pneumatyczna z wbudowaną w nią siatką Bragga, która służy
do pomiaru drgań ciała wywołanych pracą serca i aktywnością
oddechową. Podczas badań pomiary porównywano z sygnałem
referencyjnym pochodzącym z elektrod EKG. Sygnał ten
był jednak przesunięty względem sygnału z "poduszki" i nie był
sygnałem optycznym. W związku z tym było konieczne stosowanie
dodatkowej karty przetwornikowej. Potrzeba posiadania
sygnału optycznego jako sygnału odniesienia w jednym
torze interrogacji spowodowała, że opracowano dwa
światłowodowe czujniki referencyjne służące do odbioru
sygnału pulsu jako sygnału mechanicznego generowanego
przez fale przepływającej w naczyniach krwi. Jednym z czujników
referencyjnych jest wykonany na zasadzie mankietu
do pomiaru ciśnienia krwi. Drugim czujnikiem jest opisany
w niniejszej pracy mechnoakustyczny czujnik aktywności
układu sercowo-naczyniowego o konstrukcji wykorzystującej
działanie stetosk[...]
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Metal - oxide sensor array for gas detection
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Patryk Gwiżdż Andrzej Brudnik Katarzyna Zakrzewska
|
Resistive-type semiconducting gas sensors based on metal oxides
are convenient and relatively cheap devices used for detection
of reducing and oxidizing gases. It is well-known that except
for their high sensitivity, their largest drawback is the lack of selectivity.
Such sensors cannot distinguish between different gases of
the same type, e.g. hydrogen and methane because their dynamic
responses look similar. However, this cross-sensitivity, manifesting
itself as a non-zero sensor response to interfering gases,
is used to advantage in arrays of gas sensors or electronic noses
[1-2]. Application of pattern recognition schemes (PARC) allows
for classification and recognition of particular components of the
analyzed gas mixture and volatile organic compounds (VOCs)
[3-6]. Vast research field of classification based on this idea has
been established in the 80 ties of 20 th century and a new type of
device called: electronic nose has been proposed [1]. The electronic
noses are mainly designed to detect and recognize VOCs
responsible for smell [7]. Although commercial devices are now
available, there is still a need to create miniaturized portable systems.
The aim of this work was to design and construct an array of
resistive-type semiconducting sensors dedicated to detection and
recognition of components of a gas mixture especially hydrogen
and ammonia. Detection of these gases becomes increasingly
important for their use in automotive industry (ammonia) [8] and
fuel cells (hydrogen) [9].
One of the most important requirements for the supporting
electronic system is its flexibility understood as a simplicity of
reconfiguration in the case of changing number of sensors. The
analog part of the system had to be constructed in suc[...]
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Method of processing of thermal images recorded in the beam displacement modulation technique
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Mateusz Kosikowski Zbigniew Suszyński
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The need to detect thermal inhomogeneities in the materials and
devices used among the others in electronics facilitates development
of new methods to be applied for their detection, visualisation
and parametrisation. Those problems are especially important
from the point of view of the thermal parameter measurement
possibilities in layered structures, and also in adhesion quality
tests. The most popular thermal properties’ analysis methods are
the photothermal ones, including among others the photoacoustic
method [1-3]. This method consists in exciting a thermal flux
using optical radiation energy and recording temperature in the
photoacoustic chamber or using a piezoelectric converter. This
method is characterized with high sensitivity but is rather problematic
due to the necessity of placing the object in an airtight
chamber or of ensuring acoustic contact between the object and
the converter. Despite those difficulties and linear distortions related
to the indirect temperature measurement, this is a highly
sensitive method of detecting thermal inhomogeneities thanks to
the temperature measurement method. A serious disadvantage
of this method, besides the above-mentioned ones, is its low efficiency
as the measurement takes place on a spot-by-spot basis.
The photothermal methods include also active thermography.
One of the most popular types is the pulsed thermography [4].
A significant problem of this technique is the difficulty in uniform
excitation of the object on its entire surface with a high-density
optical power. Another disadvantage of the pulse thermography
is the reduced possibility of influencing the frequency spectrum of
the excitation, as well as a highly limited speed of recording particular
frames. On the other hand, however, its significant value lies
in a rapid data acquisition and the possibility of their immediate
processing.
Also the beam displacement modulation method (BDM) [5-6]
has been used fo[...]
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Modulacja amplitudy sygnałem pseudolosowym
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Rafał Stępień Janusz Walczak
|
Sygnały pseudolosowe wykorzystywane są w wielu dziedzinach
techniki. Są one stosowane między innymi w metodzie analizy
Monte Carlo [13], symulatorach procesów ekonomicznych czy
technologicznych oraz kryptografii [1]. W telekomunikacji są one
stosowane w systemach transmisji z widmem rozproszonym
DSSS [10]. Istnieje wiele metod generacji sygnałów pseudolosowych
[1, 8, 13]. Niektóre metody generacji sygnałów pseudolosowych
i własności sekwencji pseudolosowych opisano w dalszej
części artykułu.
Modulacja amplitudy należy do najprostszych rodzajów modulacji
wykorzystywanych w technice. Znanych jest kilka rodzajów
tej modulacji [12]. Najczęściej rozpatruje się przypadek modulacji
monoharmonicznej fali nośnej sinusoidalnym sygnałem modulującym
[12]. Efektem tej modulacji jest przesunięcie widma sygnału
modulującego w otoczenie częstotliwości fali nośnej. W artykule
rozpatrzono problem modulacji amplitudy monoharmonicznej fali
nośnej sygnałem pseudolosowym, w efekcie widmo sygnału pseudolosowego
zostaje przesunięte w zakres częstotliwości fali nośnej
[19]. Jednym z możliwych zastosowań rozpatrywanego procesu
modulacji jest możliwość zagłuszania transmisji w wybranym
zakresie częstotliwości kanału transmisyjnego [16]. W porównaniu
z innymi metodami zagłuszania transmisji [17] zaproponowana
metoda jest relatywnie prosta. W artykule zaproponowano układ
realizujący proces modulacji i zbadano doświadczalnie możliwość
zagłuszania transmisji w zakresie radiofonii FM-CCIR.
Sygnały pseudolosowe i wybrane metody ich
generacji
W technice cyfrowej generacja liczb pełni losowych nie jest możliwa.
Urządzenia cyfrowe są z założenia układami w pełni deterministycznymi
(o skończonej liczbie stanów) i nie mają właściwości
losowych. W kryptografii wykorzystuje się jednak algorytmy
generujące ciągi pseudolosowe [1]. Dla obserwatora sekwencji
wyjściowej generatora ciągi takie mogą mieć cechy losowe i odróżnienie
sekwencji pseudolosowej od sekwencji w [...]
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Numerical study of the interface heat transfer characteristics of micro-cooler with CNT structures
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Yan Zhang Shun Wang Shiwei Ma Zhili Hu Johan Liu Janusz Sitek Kamil Janeczek
|
With the continuously increasing packaging density in electronic
products, the system ability to dissipate heat loads has become
a concern in the overall performance. Some novel cooling techniques
have emerged to meet the thermal management requirements
of high power microelectronics components and devices.
Micro cooling, including micro-pin-fin, micro-channel and so on,
provides a promising solution for high-powered electronics.
Meanwhile, carbon nanotubes (CNTs) have shown advantages
in material properties such as the electrical conductivity [1],
[2], the thermal conductivity [3], [4] and the mechanical properties
[5], [6]. CNTs can be used as the micro-cooler construction due to
the excellent thermal conductivity [7]. A micro-channel cooler with
vertically aligned CNT arrays had been developed [8], [9], where
the CNT structures were employed as channels inside to enhance
the heat transfer. And experimental measurement had also been
carried out to evaluate the overall heat removal capability of the
CNT-based micro-cooler. Beside experimental works, the macroscopic
heat transfer characteristics of the micro-channel heat
sinks with carbon nanotubes were also studied numerically [10],
[11], in which parameters such as the inlet velocity, the heating
power, the CNT structure size as well as the flow field and the
temperature distribution were analyzed.
The most widely used fabrication method to obtain aligned
CNTs is the thermal or plasma-enhanced chemical vapour deposition
(CVD). During the process, the carrier substrate typically
needs to be heated up to approximately 700°C or even higher.
Such a high temperature is not compatible with most of the temperature-
sensitive components or devices. A transfer method was
proposed as a solution to this problem, in which the pre-prepared
CNT forest could be transferred onto the target surface at a low
temperature so that the integration of the CNTs into various device
and material pro[...]
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Oxide layers fabricated by spray pyrolysis on metallic surfaces
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Katarzyna Kobierowska Magdalena Karpińska Sebastian Molin Piotr Jasiński
|
A rapid degradation of the implants is the main problem of the
contemporary implantology. Due to the structural role of the bone,
the titanium alloys and austenitic steel, type 316L are frequently
used for the manufacturing of implants. This steel is not deformed,
does not change color, and has hypoallergic properties.
However susceptibility to pitting and crevice corrosion in chloride
ions environment are objectionable features [1].
This is a significant issue to prepare a suitable implant’s outer
layer to improve adhesion of osteogenic cells and anti-corrosion
properties.
The most commonly used methods of thin films layering are:
CVD (Chemical Vapor Deposition), PVD (Physical Vapor Deposition)
or PLD (Pulsed Laser Deposition). Unfortunately, most of
them are relatively expensive and the process is complex. It would
be useful to find the cheaper method with the less complexity.
Spray pyrolysis deposition of thin ceramic films depends on
the atomization of liquid precursor, droplet transport towards the
heated substrate, droplet impact, spreading the liquid on the substrate
and the evaporation of the solvent, then the distribution of
deposited material [2]. Such layers can be obtained when the
operating temperature is above the boiling point of the precursor.
It is important to remember about the limit of the surface temperature
above which it is not possible to obtain a continuous layers.
In this paper it has been determined the optimal conditions
preparation for the yttrium stabilized zirconium layers on the steel
substrate. The spray pyrolysis method to produce corrosion protective
[...]
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Problematyka modelowania w programie SPICE charakterystyk stałoprądowych elektroizolowanych diodowych modułów mocy zawierających diody typu PiN oraz diody typu FRED
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Jacek Dąbrowski Janusz Zarębski
|
W półprzewodnikowych elementach elektronicznych, znajdujących
zastosowanie w energoelektronice, coraz częściej stosowane
są podłoża elektroizolowane. Charakterystyczną właściwością
tych elementów jest izolacja wszystkich wyprowadzeń, a zatem
także wewnętrznej struktury półprzewodnikowej, od podstawy odprowadzającej
ciepło z obudowy. Wśród rozwiązań technicznych
pozwalających uzyskać podłoża elektroizolowane należy wymienić
technologię DCB (Direct Copper Bonding) oraz technologię
DAB (Direct Aluminum Bonding) [1, 2]. Podłoża tego typu bazują
przede wszystkim na ceramice Al2O3 lub AlN. Ceramiczne płytki
podłożowe typu DCB metalizowane są miedzią, natomiast w przypadku
podłoży typu DAB jako metal wykorzystywane jest aluminium.
Materiały na podłoża elektroizolowane dobierane są między
innymi pod kątem współczynnika rozszerzalności cieplnej tak, aby
jego wartość była zbliżona do wartości współczynnika rozszerzalności
cieplnej struktury półprzewodnikowej osadzanej na takim
podłożu. Elementy elektroizolowane często są określane mianem
modułów lub bloków. Obecnie tego typu elementy mogą zawierać
w obudowie pojedyncze przyrządy mocy (np. diody, tranzystory
MOSFET, tranzystory IGBT, tyrystory) lub kilka przyrządów (tego
samego typu lub różnych) połączonych wewnętrznie w różnych
konfiguracjach. Wytwarzane są również specjalizowane cyfrowe
moduły elektroizolowane, zawierające w jednej obudowie także
przyrządy mocy, określane mianem IPM (Intelligent Power Modules)
lub SPM (Smart Power Modules) dedykowane w szczególności
do przekształtników energii elektrycznej [3].
Podczas projektowania układów elektronicznych lub energoelektronicznych
przy wykorzystaniu komputerowych programów
symulacyjnych, np. programu SPICE, istotne jest, aby dysponować
wiarygodnymi modelami użytych elementów. Szczególnie
w przypadku programu SPICE wystarczające jest dysponowanie
wartościami parametrów modeli elementów wbudowanych w ten
program. Niestety producenci m[...]
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Study of IDE as a sensor head for interfacing with handheld electrochemical analyzer system
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Vijayalakshmi Velusamy Khalil Arshak Olga Korostynska Catherine Adley
|
Electrochemical biosensors have been receiving more attention
in recent years since they are simple to use, cost-effective, offer
high sensitivity and suitable for in situ analysis [7-10]. Applications
are mainly focused on food quality monitoring for the detection of
foodborne pathogens [11], environmental quality monitoring for
the detection of contamination of potable water resources due to
pathogenic micro organisms and industrial by-products [12, 13]
and in biosecurity for the detection of biowarfare agents [14].
An electrochemical sensor is an electrical device in which the
biological and/or the chemical information are converted to an
electrical signal, which is then processed and recorded for further
analysis.
Towards the development of an electrochemical analyzer system,
a sensor was initially designed that may be interfaced with the
handheld system comprising both the potentiostat and the impedance
analyzer. In biosensors the lower limit of detection is a big
challenge and numerous electrode geometries have been developed
during the past decade to address this problem. Among various
electrode geometries IDE have advantage in bioanalytical applications.
A thick-film gold IDE was employed in this research and
it was prepared by screen printing technique. Thick-film sensors
are advantageous since it is compact, robust and relatively cost-effective.
It is possible to mass produce from macro- to microscale,
with greater reproducibility. However, the applicability of the technology
is limited to a possible minimum line width (100 μm) [15].
The planar IDE sensors based on thick films are very wellsuited
to integrate with electronic circuits. The IDE sensors can
be combined with other planar technologies like plasma/chemical
vapor deposition for surface modification. The device produced
by the thick-film technique has the ability to facilitate as a supporting
structure upon which other sensing materials can be deposited[...]
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Technologie informacyjne w predykcji pogodowych zagrożeń w ruchu drogowym
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Andrzej W. Mitas Marcin Bernaś Marcin Bugdol Artur Ryguła
|
Systemy ochrony pogodowej stają się nierozłącznym elementem
infrastruktury drogowej. Ten stan rzeczy wymuszony jest przez
wielomilionowe straty oraz ofiary śmiertelne będące skutkiem
wpływu pogody na ruch drogowy. Dla przykładu wystarczy wymienić
tu wielo-pojazdowe kolizje na oblodzonej nawierzchni
oraz pogodowe uszkodzenia infrastruktury drogowej. Obecnie
realizowanych jest wiele projektów dla prognozy i predykcji zagrożeń
na drogach o zasięgu punktowym, a także regionalnym
lub globalnym - w skali całego kraju. Artykuł prezentuje wspólne
elementy tych systemów, propozycję integracji systemu ochrony
pogodowej oraz wyniki prac wstępnych.
Metody prognozowania pogody
Tradycyjne prognozowanie pogody realizowane jest poprzez długotrwałe
nanoszenie na mapy synoptyczne pomiarów, które odpowiadają
za ilość opadów, siłę i kierunek wiatru oraz wartości temperatur.
Opracowana w ten sposób mapa jest podstawą do prognozowania
warunków atmosferycznych przez synoptyków. Ich doświadczenie
wpływa na poprawność prognozy oraz jej powtarzalność.
Matematyczny model różniczkowy
Przy tworzeniu numerycznej prognozy pogody wykorzystuje
się komputery dużej mocy. Obliczenia pogodowe opierają się
na skomplikowanych równaniach opisujących sposób zachowania
się atmosfery. Stan atmosfery opisany jest równaniami
różniczkowymi - układem równań nieliniowych [1]. Podstawowy
układ równań zawierający zasadę zachowania pędu, zasadę
zachowania energii oraz równanie ciągłości, uzupełniony
równaniem konstytutywnym (np. równaniem gazu doskonałego
dla powietrza) nosi nazwę "równań pierwotnych" lub równań
Naviera-Stokesa (1)):
(1)
Pierwszą pracę z algorytmem predykcyjnym dla systemów opartych
o równania nieliniowe (różniczkowe) opublikowali Mayne
i Michalska: Receding Horizon Control of Non-linear Systems
w roku 1990. Obszerne omówienie algorytmów predykcyjnych
dla liniowych i nieliniowych systemów dyskretnych w czasie
zaproponowali kolejno Kwon i Han (w 2005 roku)[...]
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