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Volume 2, Year 2011, Issue 4, October-December

Volume 2, Year 2011, Issue 4, October-December

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The compact decoupling for system of thermoelasticity in viscoporous media and exponential decay
Author:
Przemysław Głowiński, Andrzej Łada
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Abstract: The problem of exponential decay for solutions of porous-thermoelasticity system, when time t ∞ is studied. For sufficiently small values of parame ter of intensity of elasticity-porosity interactions the exponential decaying is established. Th e idea of compact decoupling is applied for the system of equations. Exponential decay is proved first for the simpler decoupled system, then the prop erty is derived for the original system.

Keywords: stabilization of solutions, compact decoupling, strongly coupled hyperbolic-pa rabolic systems, uniform decaying

Area: Applied Mathematics

BibTeX:

@article{Glowinski2011,
  author = {Przemysław Głowiński and Andrzej Łada},
  title = {The compact decoupling for system of thermoelasticity in viscoporous media and exponential decay},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {4},
  pages = {3--6},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/59-the-compact-decoupling-for-system-of-thermoelasticity-in-viscoporous-media-and-exponential-decay}
}
Cell outer membrane mimetic surface as a material with improved hemocompatibility
Author:
Maciej Trzaskowski, Beata Butruk, Tomasz Ciach
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2 x
 

 

Abstract: The phenomenon of blood coagulation on the surfaces of implantable devices such as artifi cial blood vessels, valves or hearts is the major problem that has to be taken into consideration during the construction of such devices. Since the main factor that has an infl uence on clotting of blood is the surface of the material the device is made of, numerous attempts has already been undertaken to modify surfaces of existing materials in order to provide necessary protection against clot formation, very often by coating the materials with bio-active substances. Th e aim of presented study was to create a coating of phosphatidylcholine that would mimic natural cell outer membrane on the surface of polyurethane — a material already in use in construction of cardiovascular implants. Th e obtained coated materials have been evaluated with the use of FT-IR/ATR spectroscopy. Th e change in contact angle of modifi ed material was also investigated. Finally in vitro cytotoxicity tests were performed in order to examine biocompatibility of obtained material.

Keywords: phosphatidylcholine, polyurethane, cell outer membrane mimetic surface, artifi cial heart

Area: Biomedical Engineering

BibTeX:

@article{Trzaskowski2011a,
  author = {Maciej Trzaskowski and Beata Butruk and Tomasz Ciach},
  title = {Cell outer membrane mimetic surface as a material with improved hemocompatibility},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {4},
  pages = {7--10},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/60-cell-outer-membrane-mimetic-surface-as-a-material-with-improved-hemocompatibility}
}
A self-tuning fuzzy PD controller for a wheeled mobile robot operating in the presence of faults
Author:
Adam Srebro
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Abstract: This paper presents a self-tuning fuzzy PD controller designed to improve a control strategy for a wheeled mobile robot. The dynamic model of a two-wheeled mobile robot was  implemented in Matlab/Simulink environment. In this paper the trajectory tracking problem for a mobile robot in the presence of positioning system faults is considered in detail. Mamdani fuzzy reasoning is used to tune the value of proportional gain Kp and derivative gain Kd of a PD controller. A few simulations comparing the classical PD controller with self-tuning fuzzy PD are reported to show advantage of the designed self-tuning controller.

Keywords: fuzzy controller, mobile robot, nonholonomic system, trajectory tracking, fault-tolerant

Area: Mechanics, Automatics and Robotics

BibTeX:

@article{Srebro2011,
  author = {Adam Srebro},
  title = {A self-tuning fuzzy PD controller for a wheeled mobile robot operating in the presence of faults},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {4},
  pages = {11--20},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/61-a-self-tuning-fuzzy-pd-controller-for-a-wheeled-mobile-robot-operating-in-the-presence-of-faults}
}
Preparation of chitosan/calcium phosphate based injectable system for guided bone regeneration and its properties investigation
Author:
Grzegorz Bubak, Magdalena Kowalczyk, Tomasz Brynk, Witold Bojar, Martyna Kucharska, Tomasz Ciach
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3 x
 

 

Abstract: The main objective of the work was to design and fabricate an injectable biomaterial with osteoconductive properties that can be used in dental applications in peri-implant therapy concerning guided bone regeneration. For that purpose, a self-setting biomaterial consisting of chitosan/tricalcium phosphate microparticles and sodium alginate was formulated. The obtained material was characterized regarding microsphere and formed agglomerates morphology and microstructure. Physical properties, relating to setting time and mechanical properties, were also investigated. Finally, in vivo response to implanted biomaterial was studied on a rat model and compared with commercially available alloplastic material. Th e results showed that designed injectable biomaterial fulfi lled main requirements for guided bone regeneration application.

Keywords: chitosan, alginate, -tricalcium phosphate, injectable systems, guided bone regeneration, in vivo studies, biomaterial

Area: Mechanics, Automatics and Robotics

BibTeX:

@article{Bubak2011,
  author = {Grzegorz Bubak and Magdalena Kowalczyk and Tomasz Brynk and Witold Bojar and Martyna Kucharska and Tomasz Ciach},
  title = {Preparation of chitosan/calcium phosphate based injectable system for guided bone regeneration and its properties investigation},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {4},
  pages = {21--26},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/62-preparation-of-chitosan-calcium-phosphate-based-injectable-system-for-guided-bone-regeneration-and-its-properties-investigation}
}
Physico-mechanical properties of Ti-containing chromium-free conversion coatings on zinc coated steel
Author:
Juliusz Winiarski, Bogdan Szczygieł
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4 x
 

 

Abstract: This work aims at physico-mechanical properties of the Ti-containing chromium-free conversion coatings on zinc coated steel. Th e wear resistance of the whole conversion coating/zinc coating system depends on the deposition time of these coatings. As the duration of the deposition of conversion coatings containing titanium increases, the wear resistance of the samples decreases. Th e reason for this deterioration in wear resistance is likely worse adhesion of these coatings obtained at longer deposition times. Th e best adhesion to the zinc substrate posses coatings deposited for 20 s.

Keywords: zinc coating, corrosion resistance, conversion coating, adhesion, wear resistance

Area: Nanotechnologies and Materials

BibTeX:

@article{Winiarski2011,
  author = {Juliusz Winiarski and Bogdan Szczygieł},
  title = {Physico-mechanical properties of Ti-containing chromium-free conversion coatings on zinc coated steel},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {4},
  pages = {27--30},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/63-physico-mechanical-properties-of-ti-containing-chromium-free-conversion-coatings-on-zinc-coated-steel}
}
Comparison of six approaches in DTM reduction for fl ood risk determination
Author:
Krzysztof Bakuła
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6 x
 

 

Abstract: Software for creating fl ood risk maps and simulation of fl ood water is based on Digital Terrain Model (DTM). LIDAR is the most eff ective data source for DTM creation. Th e essential problem for such data is high redundancy for complex calculations in algorithms used in programs for fl ood model description. However, it is possible to provide suitable DTM for fl ood modeling by its generalization, which could still ensure suffi cient accuracy for hydrodynamic — numerical calculations. In this paper six generalization algorithms were tested to obtain DTM with small number of points and with accuracy comparable to the original model created from LIDAR data. Th e main criteria for this comparison was the relation between accuracy and reduction coeffi cient of fi nal result. Methods used in this research based on diff erent DTM structures. GRID, hybrid and hierarchical structure were compared in various creating approaches to obtain the most reduced and the most accurate terrain model of two case areas. As the result of experiment the best methods for data reduction were chosen. Over 90% reduction rate and less than 20 cm root mean standard error were achieved for diff erent types of terrain with respect to input DTM. It was noted that hybrid models can be more effi cient than a typical uniform GRID. Such reduced models were used in practice to determinate fl ood risk by creating maps of fl ooded area for selected water levels. Diff erence between results from unreduced and reduced DTMs was very slight what proves that well-generalized models of terrain can be eff ectively used in that application.

Area: Natural Science

BibTeX:

@article{Bakul2011,
  author = {Krzzztof Bakuła},
  title = {Comparison of six approaches in DTM reduction for fl ood risk determination},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {4},
  pages = {31--36},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/64-comparison-of-six-approaches-in-dtm-reduction-for-fl-ood-risk-determination}
}
Cascade reactor system for methanogenic fermentation
Author:
Sławomir Jabłoński, Anna Krasowska, Jerzy Januszewicz, Andrzej Vogt, Marcin Łukaszewicz
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4 x
 

 

Abstract: Methanogenic fermentation is promising method of obtaining environment-friendly energy. Moreover it can be used for disposal of sewage and other organic waste. However process complexity and susceptibility makes it diffi cult for application on a large scale. A new laboratory stand for studding of anaerobic digestion was developed. Th ree fermentation vessels and automated control system provides fl exibility essential in investigation of digestion of diff erent substrates and testing of diff erent reactors confi gurations. Cheese whey is a troublesome dairy waste, potentially suitable for biogas production. Stable fermentation conditions for whey fermentation were obtained with the organic loading rate of 5 kg COD/m3 and methane production effi ciency of 0,3 m3/kg COD. On the basis of obtained data the size of small biogas plant for average dairy was calculated.

Keywords: biogas, anaerobic digestion, whey, UASB, methane, sewage, fermentation, multi-step digestion

Area: Natural Science

BibTeX:

@article{Winiarski2011,
  author = {Juliusz Winiarski and Bogdan Szczygieł},
  title = {Physico-mechanical properties of Ti-containing chromium-free conversion coatings on zinc coated steel},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {4},
  pages = {27--30},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/63-physico-mechanical-properties-of-ti-containing-chromium-free-conversion-coatings-on-zinc-coated-steel}
}
Chemical pretreatment of formaldehyde wastewater by selected Advanced Oxidation Processes (AOPs)
Author:
Paweł Kowalik
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11 x
 

 

Abstract: Chemical oxidation processes: Fenton process and catalytic ozonation with Mn2+ ions were investigated for eff ectiveness of formaldehyde (FA) oxidation. Th e infl uence of operational variables — O3, H2O2, Mn2+ and Fe2+ concentrations and reaction time were investigated. Researches were carried out on aqueous solution of FA, which concentration was 500 mg/l. Fenton  process was investigated at pH 3 and catalytic ozonation at pH 7, 10 and 12. Results revealed that Fenton process was much more eff ective in FA degradation than catalytic ozonation with Mn2+ as a catalyst. Th e optimal H2O2/Fe2+ dosage for a Fenton process was 2000/1000 mg/l. COD and FA concentrations were reduced 59,6% and 79,5%. In case of catalytic ozonation with Mn2+ the eff ectiveness was much less and it was the biggest at pH 12 and Mn2+ dosage 25 mg/l where COD and FA concentration were reduced 14% and 38%. Th erefore, Fenton process can be promising technology for FA wastewater pretreatment.

Area: Natural Science

BibTeX:

@article{Kowalik2011,
  author = {Paweł Kowalik},
  title = {Chemical pretreatment of formaldehyde wastewater by selected Advanced Oxidation Processes (AOPs)},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {4},
  pages = {42--48},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/66-chemical-pretreatment-of-formaldehyde-wastewater-by-selected-advanced-oxidation-processes-aops}
}
Clathrate hydrates — effi cient and clean energy resource
Author:
Paweł Siuda, Joanna Sadlej
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4 x
 

 

Abstract: Clathrate hydrates are icelike structures in which water molecules form cavities enclathrating many possible types of guest molecules. Among most important representatives of this group of solid structures are methane and carbon dioxide clathrate hydrates. Th e fi rst one is widely present in Nature and in the future will serve as an energy resource. Carbon dioxide clathrate hydrate may on the other hand serve as a storage reservoir for this green house gas providing cheap way to lower its emission to atmosphere. Th ose are just two of many more important issues that catalyse growing interest of scientifi c world in clathrate hydrates. Characterisation of their properties is crucial to develop technologies, that will enable us to utilize their manifold possible applications. During this presentation I will discuss some of my investigations concerning NMR properties of clathrate hydrates.

Keywords: clathrate hydrates, energy, NMR

Area: Natural Science

Novel designs and technologies for cell engineering
Author:
Karina Ziółkowska, Michał Chudy, Artur Dybko, Zbigniew Brzózka
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4 x
 

 

Abstract: Microfl uidic devices, such as lab-on-a-chip systems, are highly advantageous for cell engineering and cell based assays. It is a particularly useful approach for development of the in vitro cellular systems mimicking the in vivo environment. In this paper, a novel lab-on-a-chip device for three-dimensional human cell culture and anticancer drug testing is presented. Cells were cultured as Multicellular Tumor Spheroids (MCTS) — the best cancer tumor model developed so far. Diff erent designs were tested and novel technique of microfabrication in poly(dimethylsiloxane) was developed. MCTS were cultured in a system of polymeric microwells, with the network of microfl uidic channels for culture medium fl ow. Design included optimal shear stress and proper nutrients supply for cultured cells. Final design provided MCTS culture for four weeks with the homeostasis-like state achievement, which is characteristic for the in vivo situation.

Keywords: lab-on-a-chip, multicellular tumor spheroid, cancer, in vitro cell culture, cell engineering

Area: Natural Science

BibTeX:

@article{Ziolkowska2011a,
  author = {Karina Ziółkowska and Michał Chudy and Artur Dybko and Zbigniew Brzózka},
  title = {Novel designs and technologies for cell engineering},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {4},
  pages = {54--60},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/68-novel-designs-and-technologies-for-cell-engineering}
}
Methods for Scenario Development
Author:
Kateryna Pereverza
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4 x
 

 

Abstract: This paper is devoted to scenario development process and methods which are used at diff erent stages of it. Stages of identifi cation of system’s key variables, driving forces and their possible states, assessment of infl uence, generation of scenario confi gurations, and analysis of these confi gurations are described; some methods for these stages are proposed.

Keywords: scenario, scenario analysis, strategy, morphological analysis, SWOT analysis, key variables, driving forces, consistency

Area: Social Sciences in Technology

BibTeX:

@article{Pereverz2011,
  author = {Kateryna Pereverza},
  title = {Methods for Scenario Development},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {4},
  pages = {61--63},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/69-methods-for-scenario-development}
}
 
 
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