Up

Volume 2, Year 2011, Issue 2, April-June

Volume 2, Year 2011, Issue 2, April-June

Computational Methods for Stochastic Differential Equations and Stochastic Partial Differential Equations Involving Standard Brownian and Fractional Brownian Motion
Author:
Jason Shea, Ioannis Zachariou, Bozenna Pasik-Duncan
Downloads:
9 x
 

 

Abstract: As more applied science researchers are attempting to use Stochastic Diff erential Equations (SDEs) as well as Stochastic Partial Diff erential Equations (SPDEs) in their modeling, especially when involving Fractional Brownian Motion (fBM), one common issue appears: an exact solution cannot always be found. For cases involving SPDEs, exact solutions commonly do not exist and approximation schemes for their solution are typically still in development. Th erefore, in this paper, we test various Numerical methods in solving SDEs and SPDEs with standard BM that have non-linear coeffi cients. In addition we extend our results to problems with fBM.

Keywords: Brownian Motion (BM), fractional Brownian Motion (fBM), SDEs, SPDEs, Numerical Approximations

Area: Applied Mathematics

BibTeX:

@article{Shea2011,
  author = {Jason Shea and Ioannis Zachariou and Bozenna Pasik-Duncan},
  title = {Computational Methods for Stochastic Differential Equations and Stochastic Partial Differential Equations Involving Standard Brownian and Fractional Brownian Motion},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {2},
  pages = {3--12},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/22-computational-methods-for-stochastic-differential-equations-and-stochastic-partial-differential-equations-involving-standard-brownian-and-fractional-brownian-motion}
}
Application of modern semiconductor devices from silicon carbide for the construction of the synchronous rectifiers
Author:
Adam Krupa
Downloads:
6 x
 

 

Abstract: In low-voltage isolated DC-DC converters, power losses due to the conduction of rectifying devices are signifi cant. Using synchronous rectifi ers instead of the conventional fast recovery diodes is an eff ective solution to this problem in most topologies. Th is paper provides results of computer simulation in PSpice of implementation SiC (silicon-carbide) diode in synchronous rectifi er topology and shows advantages of this solution

Keywords: SiC-device, synchronous rectifi er, transformer

Area: Electronics and Informational Technologies

BibTeX:

@article{Krup2011,
  author = {Adam. Krupa},
  title = {Application of modern semiconductor devices from silicon carbide for the construction of the synchronous rectifiers},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {2},
  pages = {13--15},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/23-application-of-modern-semiconductor-devices-from-silicon-carbide-for-the-construction-of-the-synchronous-rectifiers}
}
Computer vision based navigation systems —requirements and proposed system idea
Author:
Marcin Morański
Downloads:
8 x
 

 

Abstract: This article highlights the main challenges and constrains concerning computer vision based navigation systems. A few special conditions in which the systems have to work are pointed out. Diff erent approaches to sense the surrounding environment are reviewed. Finally, the navigation system which incorporates two computer vision techniques: time of fl ight and stereovision is proposed.

Keywords: computer vision, navigation, depth estimation, distance measurements, obstacle detection, collision avoidance

Area: Electronics and Informational Technologies

BibTeX:

@article{Moranski2011,
  author = {Marcin Morański},
  title = {Computer vision based navigation systems —requirements and proposed system idea},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {2},
  pages = {16--18},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/24-computer-vision-based-navigation-systems-requirements-and-proposed-system-idea}
}
Segmentation with image thresholding algorithms
Author:
Sylwia Sikorska
Downloads:
5 x
 

 

Abstract: The first step in image analysis and pattern recognition is image segmentation and it is one of the most diffi cult tasks in image processing. It determines the quality of the fi nal result of analysis because it is very important and critical component. Th ere are hundreds of segmentation techniques in literature. Th ere is no single method which can be considered good for all sorts of images and conditions. In many applications of image processing, the gray levels of pixels belonging to the object are substantially diff erent from the gray levels of the pixels belonging to the background. Th resholding then becomes a simple but eff ective tool to separate objects from the background. To improve the segmentation results, a strategy consists in combining algorithms in order to obtain a robust segmentation by exploiting the advantages of one method to reduce the drawbacks of the second one. This paper provides a summary of approaches to image segmentation by thresholding available at the present and describes the properties of diff erent kinds of methods and problems encountered. Th ere will be also presented some advanced algorithms with their practical application.

Keywords: image analysis, segmentation, thresholding algorithm

Area: Electronics and Informational Technologies

BibTeX:

@article{Sikorsk2011,
  author = {Sylwia Sikorska},
  title = {Segmentation with image thresholding algorithms},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {2},
  pages = {19--22},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/25-segmentation-with-image-thresholding-algorithms}
}
Resonant Controller for Higher Harmonics Compensation in PWM rectifiers
Author:
Małgorzata Bobrowska-Rafał, Krzysztof Rafał, Szymon Piasecki, Marek Jasiński
Downloads:
8 x
 

 

Abstract: In this article algorithm for minimizing negative impact of higher harmonics on proper operation of PWM rectifi er is presented. Short overview of harmonics compensation methods is also given. Furthermore, Resonance Harmonic Compensator is widely described. Simulation results of compensation of harmonics are presented.

Keywords: higher harmonics, harmonic compensation, THD, PWM rectifier

Area: Mechanics, Automation and Robotics

BibTeX:

@article{Bobrowska2011,
  author = {Małgorzata Bobrowska-Rafał and Krzysztof Rafał and Szymon Piasecki and Marek Jasiński},
  title = {Resonant Controller for Higher Harmonics Compensation in PWM rectifiers},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {2},
  pages = {23--26},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/26-resonant-controller-for-higher-harmonics-compensation-in-pwm-rectifiers}
}
Problems regarding stress between offset printing rollers
Author:
Agnieszka Jurkiewicz, Yuriy Pyryev
Downloads:
5 x
 

 

Abstract: At present, companies show particular care about quality and profit which are inherent with costs. An in adequately set stress between the printing rollers may significantly worsen the quality and increase costs of printing. Until now, a contact between rollers used to be set by a printer, where it was based on his experience. A width of the surface contact was measured or a distance between the form plate or the rubber to the bearer rings (rings made of hardened metal) was calculated. Th is paper includes a presentation regarding an attempt to solve the contact-related problems by way of mathematical methods

Keywords: contact problem, stress, offset, blanket cylinder

Area: Mechanics, Automation and Robotics

BibTeX:

@article{Jurkiewicz2011,
  author = {Agnieszka Jurkiewicz and Yuriy Pyryev},
  title = {Problems regarding stress between offset printing rollers},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {2},
  pages = {27--30},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/27-problems-regarding-stress-between-offset-printing-rollers}
}
Analysis of vibration of printing unit of offset printing press
Author:
Juliusz Krzyżkowski, Yuriy Pyryev
Downloads:
16 x
 

 

Abstract: There are several causes of vibration of off set printing presses. Major are cyclic work of feeders and deliveries, gaps with mechanisms for fi xing plate and blanket in cylinders of printing pair and inappropriate stress between those cylinders. All mentioned above causes increased exploitation of bearings, gears driving cylinders and other parts of the printing press. The consequences of vibration are also breaking of paper web and such artefacts as doubling and streaking on the prints. In this paper printing pair cylinders of lithographic printing press are described as a two-degree of freedom model. Solution of a system of diff erential equations, which describes this model shows infl uence of vibration of printing unit cylinders on the fl uctuation of the ink fi lm thickness on the prints (magnitude of streaking phenomenon).

Keywords: lithographic printing, off set printing, off set presses, printing unit, plate cylinder, blanket cylinder

Area: Mechanics, Automation and Robotics

BibTeX:

@article{Krzyzkowski2011,
  author = {Juliusz Krzyżkowski and Yuriy Pyryev},
  title = {Analysis of vibration of printing unit of offset printing press},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {2},
  pages = {31--34},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/28-analysis-of-vibration-of-printing-unit-of-offset-printing-press}
}
Resistance to ageing of selected books of children’s literature
Author:
Marta Gajadhur, Halina Podsiadło, Sylwia Abramczyk
Downloads:
4 x
 

 

Abstract: Resistance to ageing was studied for a number of selected items of children’s literature. Print rub-off tests were performed for 3 bases used in printing of children’s books, namely plastic sheets, white uncoated (off set) paper, and varnished prints. Three children’s books used in the experimental works were: a “bathing book” printed by fl exographic technique on plastic sheets, a book printed on uncoated white paper, and a book printed on double-sided varnish-coated cardboard. Rub-off resistance tests were performed on Ink Rub Tester under identical rub rate (85 cycles/min). Th e resistance was evaluated by spectrophotometric and densitometric method and by visual observations. About 6000 rub-off cycles were performed for each of the books tested

Keywords: rub-off resistance, resistance to destruction processes, colour coordinates, partial main optical density, production of children’s books

Area: Nanotechnologies and Materials

BibTeX:

@article{Gajadhur2011,
  author = {Marta Gajadhur and Halina Podsiadło and Sylwia Abramczyk},
  title = {Resistance to ageing of selected books of children’s literature},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {2},
  pages = {35--37},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/29-resistance-to-ageing-of-selected-books-of-children-s-literature}
}
Preparation and characterization of ultra-fi ne silver bromide suspension
Author:
Agnieszka Król-Gracz, E. Michalak, P. Nowak, A. Dyonizy
Downloads:
4 x
 

 

Abstract: This paper present the results of studies on ultra fi ne-crystalline silver bromide suspensions, which were stabilized by gelatin and excess of bromide ions. Relation between dosing rate of reactants to size of obtained silver bromide crystals was investigated. Granulometric properties obtained nanocrystals were studied by turbidity method and by technique of Dynamic Light Scattering (DLS). Additionally, a photomicrograph of suspension using Scanning Electron Microscopy (SEM) was performed.

Keywords: nanoparticles, silver bromide, synthesis method, gelatine

Area: Nanotechnologies and Materials

BibTeX:

@article{Krol2011,
  author = {Agnieszka Król-Gracz and E. Michalak and P. Nowak and A. Dyonizy},
  title = {Preparation and characterization of ultra-fine silver bromide suspension},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {2},
  pages = {38--42},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/30-preparation-and-characterization-of-ultra-fi-ne-silver-bromide-suspension}
}
Mechanisms of the potassium stabilization in K2Fe22O34
Author:
Michał Trębala
Downloads:
6 x
 

 

Abstract: Effect of potassium stabilization in K2Fe22O34, the principal phase of styrene catalyst is caused by doping Cr and Ce. The effect was investigated by means of potassium ion and neutral atom thermal desorption. Th e kinetics for K+ and K emission from undoped and Ce-, Cr-doped b-K2Fe22O34 is studied with the fi eld reversal technique and steady-state mode in high vacuum conditions. Two main mechanisms of the stabilization were developed depending on the dopant location. Chromium is located in the structure of -ferrite and slows down the diff usion potassium ion. Cerium segregated at the basal planes favoring the cationic state of potassium inhibits the probability of potassium atoms to leave the K2Fe22O34 surface via work function increase

Keywords: Potassium ferrite, Styrene catalyst, potassium lost, work function, potassium desorption

Area: Nanotechnologies and Materials

BibTeX:

@article{Trebal2011,
  author = {Michał Trębala},
  title = {Mechanisms of the potassium stabilization in K2Fe22O34},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {2},
  pages = {43--45},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/31-mechanisms-of-the-potassium-stabilization-in-k2fe22o34}
}
New methods for inactivation of Alicyclobacillus acidoterrestris spores in apple juice concentrate
Author:
Małgorzata Djas, Magdalena Bober, Marek Henczka
Downloads:
9 x
 

 

Abstract: This paper is focused on new methods for inhibiting Alicyclobacillus acidoterrestris spores germination in apple juice concentrate. Four methods such as pulsed electric fi eld (PEF), ultrasound (US), integrated method of PEF and US and microwaves (MW) have been investigated. The highest effi ciency of spores inactivation was obtained after microwave treatment

Keywords: Alicyclobacillus acidoterrestris, spores, inactivation, pulsed electric fi eld (PEF), ultrasound (US), microwaves (MW)

Area: Natural Science

BibTeX:

@article{Djas2011,
  author = {Małgorzata Djas and Magdalena Bober and Marek Henczka},
  title = {New methods for inactivation of Alicyclobacillus acidoterrestris spores in apple juice concentrate},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {2},
  pages = {46--49},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/32-new-methods-for-inactivation-of-alicyclobacillus-acidoterrestris-spores-in-apple-juice-concentrate}
}
Miniaturized device for a cell lysis process
Author:
Radosław Kwapiszewski, Michał Chudy, Artur Dybko, Zbigniew Brzózka
Downloads:
3 x
 

 

Abstract: Single-cell studies are crucial for gaining knowledge on complexity of intracellular processes. In many cases, carrying researches into cell ingredients must be proceeded by a lysis process. Cell lysis leads to disintegration of the plasma membrane which is the barrier separating cell contents from the environment. However, investigations at the cellular level would not be possible without proper miniaturized tools, which off er many advantages as low reagents consumption, short reaction time, integration, automation or versatility. The goal of this work was to design and develop a microfl uidic chip for a chemical cell lysis process. The geometry of a microsystem presented is based on the hydrodynamic focusing of a cell suspension stream. Applying non-denaturing cell lysis buff er enables to analyze released cell ingredients during next steps of investigations.

Keywords: microdevice, microfl udic chip, chemical cell lysis, sheath fl ow, hydrodynamic focusing

Area: Natural Science

BibTeX:

@article{Kwapiszewski2011,
  author = {Radosław Kwapiszewski and Michał Chudy and Artur Dybko and Zbigniew Brzózka},
  title = {Miniaturized device for a cell lysis process},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {2},
  pages = {50--52},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/33-miniaturized-device-for-a-cell-lysis-process}
}
Consumer Perceptions of the Nutrition Labeling of Food Products
Author:
Monika Mieczkowska, Helena Panfil-Kuncewicz
Downloads:
4 x
 

 

Abstract: The objective of this study was to evaluate consumer perceptions and preferences regarding food labeling and the information displayed on the packaging of food products, with particular emphasis on nutrition facts. Th e survey covered 283 respondents who were asked to fi ll out a questionnaire.

Keywords: nutritional value, labeling, packaging, consumer research

Area: Natural Science

BibTeX:

@article{Mieczkowska2011,
  author = {Monika Mieczkowska and Helena Panfil-Kuncewicz},
  title = {Consumer Perceptions of the Nutrition Labeling of Food Products},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {2},
  pages = {53--55},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/34-consumer-perceptions-of-the-nutrition-labeling-of-food-products}
}
Application of computer image analysis and scanning electron microscopy in environmental engineering and waste management
Author:
Dominika Katarzyna Szponder, Kazimierz Trybalski
Downloads:
6 x
 

 

Abstract: Creation and refi nement of modern research methods in the last century had a signifi cant impact on the dynamic development of various fi elds of science. Special attention deserves computer image analysis and scanning electron microscopy. Th ese methods can be used in virtually any fi eld of science dealing with solids. Modern methods have many applications in environmental engineering. Studies, using the above advanced testing methods are also widely used in waste management. The article presents progressive research methodology of using image analysis and scanning electron microscopy in environmental engineering and waste management. It especially presents the application of these methods to determine physical, chemical and mineralogical properties of solid waste.

Keywords: scanning electron microscopy, computer image analysis, solid waste, and environmental engineering

Area: Natural Science

BibTeX:

@article{Szponder2011,
  author = {Dominika Katarzyna Szponder and Kazimierz Trybalski},
  title = {Application of computer image analysis and scanning electron microscopy in environmental engineering and waste management},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {2},
  pages = {56--62},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/35-application-of-computer-image-analysis-and-scanning-electron-microscopy-in-environmental-engineering-and-waste-management}
}
Pathways of tRNA turnover in eukaryotic cells
Author:
Tomasz Wojciech Turowski
Downloads:
2 x
 

 

Abstract: Cell ability to control amount of a transfer RNA is one of the ways to regulate rate of protein synthesis. Because 80–90% dry mass of cells are proteins, the level of translation is determinant to the cell growth. Growth of cells is a key question in tumors therapy and biotechnology. tRNA turnover consist of a three pathways described in a last few years: exosome and TRAMP complex dependent pathway in nucleus, directed to hypomodifi ed or aff ected tRNA; rapid tRNA decay pathway involving two 5’–3’ exonucleases Rat1 and Xrn1, proposed to occur in nucleus and cytoplasm; stress-activated endonucleolytic cleavage to tRNA halves pathway, founded in cytoplasm with a clear role to direct regulation of translation by tRNA half-molecules inhibition

Keywords: tRNA turnover, rapid tRNA decay, polymerase III

Area: Natural Science

BibTeX:

@article{Turowski2011,
  author = {Tomasz Wojciech Turowski},
  title = {Pathways of tRNA turnover in eukaryotic cells},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {2},
  pages = {63--65},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/36-pathways-of-trna-turnover-in-eukaryotic-cells}
}
Sunset Yellow sorption on weak base anion exchanger — kinetic and equilibrium studies
Author:
Monika Wawrzkiewicz, Anna Wołowicz, Magdalena Greluk, Zbigniew Hubicki
Downloads:
2 x
 

 

Abstract: The sorption equilibrium and kinetics of Sunset Yellow dye in aqueous solutions on the weak base anion exchange resin — Amberlite FPA51 were examined in this paper. Th e infl uences of phase contact time, solution pH, initial dye concentration and temperature were studied by the batch method. Th e amounts of dye sorbed at equilibrium changed from 9.9 to 48.7 mg/g with the increasing initial concentrations in the range 100–500 mg/L. Th e experimental data were analyzed by the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich models of adsorption. Th e maximum monolayer capacity was 130.6 mg/g. The sorption free energy was equal to 14.6 kJ/mol and revealed the nature of the ion exchange mechanism in this system. The kinetic data were modelled using the pseudo-fi rst order, pseudo-second order and intraparticle diff usion equations.

Keywords: dye, anion exchanger, adsorption, kinetics

Area: Natural Science

BibTeX:

@article{Wawrzkiewicz2011,
  author = {Monika Wawrzkiewicz and Anna Wołowicz and Magdalena Greluk and Zbigniew Hubicki},
  title = {Sunset Yellow sorption on weak base anion exchanger — kinetic and equilibrium studies},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {2},
  pages = {66--70},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/37-sunset-yellow-sorption-on-weak-base-anion-exchanger-kinetic-and-equilibrium-studies}
}
Equilibrium and kinetic studies of palladium(II) ions sorption onto Dowex resins
Author:
Anna Wołowicz, Zbigniew Hubicki, Magdalena Greluk
Downloads:
3 x
 

 

Abstract: Palladium(II) sorption was studied in hydrochloric acid solutions with sodium chloride addition onto Dowex MSA-1 and Dowex MSA-2 resins by means of the static method. Th e dependence between the amount of palladium(II) ions sorbed at time tin a disequilibrium state (qt) as well as the sorption capacities (qe) and phases contact time were obtained. Th e results were applied in kinetic studies using the pseudo-fi rst (Lagergren equation) and pseudo-second order kinetic equations (linear form of Blanchard equation proposed by Ho, PSO). Moreover, the equilibrium studies were caried out at ambient temperature and fi tted to the Langmuir and Freundlich isotherms. Th e AFM pictures of the surface of anion exchange resins before and after the loading process were also recorded. Both resins exhibit high selectivity towards palladium(II) ions. Th e sorption capacities are in the range 7–10 mg/g for both resins under discussion in all examined solutions. Th e pseudo-second order kinetic equation and the Langmuir isotherm show the best fi t with the experimental data.

Keywords: palladium, sorption, pseudo-fi rst order kinetic equation, pseudo-second order kinetic equation, isotherms

Area: Natural Science

BibTeX:

@article{Wolowicz2011,
  author = {Anna Wołowicz and Zbigniew Hubicki and Magdalena Greluk},
  title = {Equilibrium and kinetic studies of palladium(II) ions sorption onto Dowex resins},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {2},
  pages = {71--75},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/38-equilibrium-and-kinetic-studies-of-palladium-ii-ions-sorption-onto-dowex-resins}
}
Interaction of the City Integrant (on the Example of Northern Kazakhstan Cities)
Author:
Yevgeniya M. Khorovetska
Downloads:
5 x
 

BibTeX:

@article{Khorovetsk2011,
  author = {Yevgeniya M. Khorovetska},
  title = {Interaction of the City Integrant (on the Example of Northern Kazakhstan Cities)},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {2},
  pages = {76--78},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/39-interaction-of-the-city-integrant-on-the-example-of-northern-kazakhstan-cities}
}
Socially-functional Researches in Town-Planning (on the Example of Northern Kazakhstan Cities)
Author:
Yevgeniya M. Khorovetska
Downloads:
4 x
 

BibTeX:

@article{Khorovetsk2011a,
  author = {Yevgeniya M. Khorovetska},
  title = {Socially-functional Researches in Town-Planning (on the Example of Northern Kazakhstan Cities)},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {2},
  pages = {79--80},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/40-socially-functional-researches-in-town-planning-on-the-example-of-northern-kazakhstan-cities}
}
Symbol as a versatile language of communication in Polish contemporary sacred architecture
Author:
Anna Maria Wierzbicka
Downloads:
5 x
 

BibTeX:

@article{Wierzbick2011,
  author = {Anna Maria Wierzbicka},
  title = {Symbol as a versatile language of communication in Polish contemporary sacred architecture},
  journal = {Challenges of Modern Technology},
  year = {2011},
  volume = {2},
  number = {2},
  pages = {81--85},
  url = {http://www.journal.young-scientists.eu/index.php/isuues/file/41-symbol-as-a-versatile-language-of-communication-in-polish-contemporary-sacred-architecture}
}
 
 
Powered by Phoca Download