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Tytuł:
An Automatic Synthesis of Musical Phrases from Multi-Pitch Samples
Autorzy:
Pluta, M.
Spalek, L. J.
Delekta, R. J.
Powiązania:
https://bibliotekanauki.pl/articles/177577.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sound synthesis
synthesis methods
sampling
Concatenative Sound Synthesis
Opis:
Sound synthesizers are a natural element of a musician’s toolset. In music arrangement, samplers can often produce satisfactory results, but it requires a combination of manual and automatic methods that may be arduous at times. Concatenative Sound Synthesis reproduces many of natural performance- and expression-related nuances but at a cost of high demand for processing power. Here, another method of musical phrase synthesis aimed at music arrangement is presented that addresses these and other related issues. Contrary to common practice, we propose to record and utilize sound samples containing not one, but short sequences of pitches. In effect, natural pitch transitions are preserved and phrases appear to be much smoother, despite using very limited set of performance rules. The proof-of-concept implementation of the proposed method is discussed in detail along with attempts at optimizing the final sound effects, based on auditory tests. The limitations and future applications of the synthesizer are also discussed.
Źródło:
Archives of Acoustics; 2017, 42, 2; 235-247
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A parametric synthesizer of audio signals on FPGA
Autorzy:
Borko, J.
Dulnik, G.
Grzelka, A.
Łuczak, A.
Paszkowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/114575.pdf
Data publikacji:
2015
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
FPGA
sound synthesis
Opis:
The paper presents a sound synthesizer dedicated to parametric sound compression, but also able to generate any signal in the audible band. The synthesizer is realized on an FPGA platform, and it uses additive sound synthesis. The synthesizer is characterized by a high quality, faithful reproduction of sound and low power consumption.
Źródło:
Measurement Automation Monitoring; 2015, 61, 7; 367-369
2450-2855
Pojawia się w:
Measurement Automation Monitoring
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Methylation demand: a key determinant of homocysteine metabolism.
Autorzy:
Brosnan, John
Jacobs, Rene
Stead, Lori
Brosnan, Margaret
Powiązania:
https://bibliotekanauki.pl/articles/1043276.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
total plasma homocysteine
liver
creatine synthesis
phospholipid synthesis
S-adenosylmethionine
Opis:
Elevated plasma homocysteine is a risk factor for cardiovascular disease and Alzheimer's disease. To understand the factors that determine the plasma homocysteine level it is necessary to appreciate the processes that produce homocysteine and those that remove it. Homocysteine is produced as a result of methylation reactions. Of the many methyltransferases, two are, normally, of the greatest quantitative importance. These are guanidinoacetate methyltransferase (that produces creatine) and phosphatidylethanolamine N-methyltransferase (that produces phosphatidylcholine). In addition, methylation of DOPA in patients with Parkinson's disease leads to increased homocysteine production. Homocysteine is removed either by its irreversible conversion to cysteine (transsulfuration) or by remethylation to methionine. There are two separate remethylation reactions, catalyzed by betaine:homocysteine methyltransferase and methionine synthase, respectively. The reactions that remove homocysteine are very sensitive to B vitamin status as both the transsulfuration enzymes contain pyridoxal phosphate, while methionine synthase contains cobalamin and receives its methyl group from the folic acid one-carbon pool. There are also important genetic influences on homocysteine metabolism.
Źródło:
Acta Biochimica Polonica; 2004, 51, 2; 405-413
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Methods of controller synthesis using linear matrix inequalities and model predictive control
Autorzy:
Miller, A.
Rybczak, M.
Powiązania:
https://bibliotekanauki.pl/articles/135474.pdf
Data publikacji:
2015
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
controller synthesis
LMI
MPC
predictive controller
controller synthesis methods
optimization methods
Opis:
Controllers based on linear matrix inequalities (LMI) and model predictive control (MPC) both use optimization methods; there are however significant differences between them. In case of LMI controllers, optimization is carried out during controller synthesis, because LMI’s are an optimization tool that requires a linear programming problem being solved. With MPC controllers, however, optimization methods are not used as much in controller synthesis as in controller algorithm operation, to determine optimal control signal values based on the found minimum of the criteria function. A square function is used with boundaries from above and below, which requires a square programming problem, with boundaries for decision variables, being solved. In this paper controller synthesis methods using LMI and MPC are shown, with a focus on the steps that need to be performed, and a comparison of both methods.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2015, 43 (115); 22-28
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sonochemical synthesis of drug molecules nanoparticles: towards controlled drug release
Autorzy:
Chytrosz, P.
Golda-Cepa, M.
Kotarba, A.
Powiązania:
https://bibliotekanauki.pl/articles/286014.pdf
Data publikacji:
2018
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
nanoparticles
drugs
sonochemical synthesis
Źródło:
Engineering of Biomaterials; 2018, 21, 148; 69
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and Implementation of Reconfigurable PLC on FPGA Platform
Autorzy:
Milik, A.
Hrynkiewicz, E.
Powiązania:
https://bibliotekanauki.pl/articles/226640.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
PLC
LD
IL
FPGA
high level synthesis
logic synthesis
arithmetic circuits
reconfigurable hardware
Opis:
The paper presents a set of algorithms dedicated for synthesis of reconfigurable logic controllers implemented on FPGA platform and programmed according to IEC1131 and EN61131. The program is compiled to hardware structure with a massive parallel processing. The developed method automatically allocates resources and operations. It controls resource usage and operation timing. Using mixed concept of operation allocation that considers operation timing and forms combinatorial chains of operations number of execution cycles can be reduced. An example of logic functions, PID controller and mixed arithmetic and logic programming examples are considered. Introducing the automatic implementation method allows flexible implementing the control algorithms. The maximal possible parallelism (limited only by the algorithm dependencies and available resources) is introduced.
Źródło:
International Journal of Electronics and Telecommunications; 2012, 58, 1; 85-94
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
KIERKEGAARD AND THE CONCEPT OF NEGATIVE DIALECTICS OF THEODOR ADORNO
Autorzy:
Krawerenda-Wajda, Katarzyna
Powiązania:
https://bibliotekanauki.pl/articles/647184.pdf
Data publikacji:
2012
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
Kierkegaard
Adorno
dialectic
synthesis
mind
Opis:
The main subject of this paper is the influence of Kierkegaard's philosophy on the concept of Adorno's dialectics. This article is focused on the analysis of Adorno's work published in 1966 titled Negative Dialec-tics. Adomo 's concept of dialectics, which is based on undefined experience, is broadly similar to the "negative" concept of existential philosophy of Kierkegaard. Although Adomo uses the Hegelian dialectics to expose the ways in which Kierkegaard’s thoughts fali into idealism. Finally, Adomo adopts Kierkegaard’s criticism of Hegelian identity of thinking. Adomo, in Negative Dialectics refers to Kant, Hegel Heidegger, but seldom to Kierkegaard. A careful analysis shows that a number of themes and concepts of its predecessor have been assimilated to his philosophy.
Źródło:
Studia Humanistyczne AGH; 2012, 11, 3
2084-3364
Pojawia się w:
Studia Humanistyczne AGH
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dialektyka i synteza. O Pascalowskiej filozofii człowieka
Autorzy:
Błaszczyk, Marek
Powiązania:
https://bibliotekanauki.pl/articles/631051.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
individual existence
paradox
dialectics
synthesis
Opis:
The study focuses on the characteristically Pascalian attempt at synthesizing of contradictory and intensely remote extremes of existence. Assuming the form of existential dialectics, the paradox of Pascalian vision refers in particular to the human, demonstrating the non-reducible tension between the intuitive (irrational) and the rational (panlogical); between the heart and the mind, between faith and knowledge. The conviction of human misery or the worldly vanity is fused here with the simultaneous sense of human greatness (the power of thought). The tension which therefore spans those dichotomous ontological-ontic dimensions is the determining factor of the constitution of individual existence.
Źródło:
Studia Europaea Gnesnensia; 2015, 11; 83-96
2082-5951
Pojawia się w:
Studia Europaea Gnesnensia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New Synthetic Methods for 4,4’,5,5’-Tetranitro-2,2’-bi- 1H-imidazole (TNBI)
Autorzy:
Szala, M.
Lewczuk, R.
Powiązania:
https://bibliotekanauki.pl/articles/358154.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
tetranitrobiimidazole
nitration
synthesis
explosive properties
Opis:
Four new nitration methods for the synthesis of 4,4’,5,5’-tetranitro-2,2’- bi-1H-imidazole (TNBI) were examined. TNBI was synthesized by nitration of 2,2’-bi-imidazole (BI) with the following mixtures: (CH3CO)2O/HNO3, (CF3CO)2O/ HNO3, P4O10/HNO3 and H3PO4/P4O10/HNO3. Nitration of BI with a mixture of nitric acid and acetic anhydride leads to 4,4’-dinitro-bi-imidazole. The other nitrating conditions investigated gave TNBI in lower yields (6.0-22.4%). Crystallization of crude TNBI from wet ethanol/acetone gave TNBI as its dihydrate. The structures of BI and TNBI were characterized by 1H, 13C and 15N NMR spectroscopy and elemental analysis. Friction and impact sensitivity, detonability and detonation velocity were determined for pure TNBI dihydrate.
Źródło:
Central European Journal of Energetic Materials; 2015, 12, 2; 261-270
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
In silico screening, synthesis, in vitro evaluations antibacterial and DPPH scavenging activity of some 1,3,5-trisubstituted 2-pyrazoline derivatives as dihydrofolate reductase inhibitors
Autorzy:
Suriya, S.
Mala, V.
Powiązania:
https://bibliotekanauki.pl/articles/1112558.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Synthesis
antibacterial
antioxidant
chalcone
pyrazoline
Opis:
In this work, synthesis of three pyrazoline derivatives (6-8) is described. (E)-1,3-(phenylsubstituted)-prop-2-en-1-one (3-5) is prepared by the reaction of substituted benzaldehyde with 4-methylacetophenone, whereas condensation cyclization of the same chalcones (3-5) with phenylhydrazine hydrate in ethanol yielded 6-8. The structures of the title compounds (6-8) were characterized by chemical reactions, elemental analysis, and spectral methods such as IR spectra. The synthesized chalcone and pyrazolines were evaluated for in-vitro antibacterial and antioxidant activities against standard. The zone of inhibition for some of the newly synthesized compounds showed notable antibacterial activity against selected bacterial strains when compared with ampicillin. Significant antioxidant activities were also shown by chalcone and pyrazolines.
Źródło:
World News of Natural Sciences; 2018, 18, 2; 180-186
2543-5426
Pojawia się w:
World News of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of Indexed Partition Calculus in Logic Synthesis of Boolean Functions for FPGAs
Autorzy:
Rawski, M.
Powiązania:
https://bibliotekanauki.pl/articles/226483.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
indexed partition
logic synthesis
FPGA
Opis:
Functional decomposition of Boolean functions specified by cubes proved to be very efficient. Most popular decomposition methods are based on blanket calculus. However computation complexity of blanket manipulations strongly depends on number of function's variables, which prevents them from being used for large functions of many input and output variables. In this paper a new concept of indexed partition is proposed and basic operations on indexed partitions are defined. Application of this concept to logic synthesis based on functional decomposition is also discussed. The experimental results show that algorithms based on new concept are able to deliver good quality solutions even for large functions and does it many times faster than the algorithms based on blanket calculus.
Źródło:
International Journal of Electronics and Telecommunications; 2011, 57, 2; 209-216
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chitosan derivatives - synthesis and characterization
Autorzy:
Szulc, Marta
Lewandowska, Katarzyna
Powiązania:
https://bibliotekanauki.pl/articles/1844946.pdf
Data publikacji:
2020
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
chitosan
synthesis
characterization
synteza
charakterystyka
Źródło:
Engineering of Biomaterials; 2020, 23, 158 spec. iss.; 11
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of PVA Polymer Type and Calcination Temperature on Synthesis of Nanocrystalline Yttria Powder by Polymer Solution Route
Autorzy:
Yang, Y.-K.
Lee, S.-J.
Powiązania:
https://bibliotekanauki.pl/articles/356024.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
yttria
PVA
nanocrystalline
synthesis
nanowire
Opis:
Nano-sized yttria (Y2O3) powders were synthesized by a polymer solution route using polyvinyl alcohol (PVA) as an organic carrier. The PVA polymer affected the dispersion of yttrium ions in precursor sol. In this study, three kinds of PVA polymer (different molecular weight) were applied for synthesis of yttria powder. The PVA type as well as calcination temperature had a strongly influence on the particle morphology. Single crystal nano wire particles were observed at the temperature of polymer burn out range and the size was dependent on the PVA type. The stable, fully crystallized yttria powder was obtained through the calcination at 800°C for 1 h. The yttria powder prepared with the high weight PVA (MW: 153,000) revealed a particle size of 30 nm with a surface area of 18.8 m2/g.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 3; 1473-1476
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Review of Nano-thermites: a Pathway to Enhanced Energetic Materials
Autorzy:
Zaky, Mohamed Gaber
Elbeih, Ahmed
Elshenawy, Tamer
Powiązania:
https://bibliotekanauki.pl/articles/27787860.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
energetic materials
nanothermite
synthesis
applications
Opis:
Nano-thermites or metastable intermolecular composites (MICs) have been implemented into modern research on energetic materials as they offer much higher energy densities, higher rates of energy release, stability, and safety (lower sensitivity). This paper reviews several synthetic methods for MICs that have been well thought-out for energetic applications, advantages and disadvantages, as well as the characteristics of each manufacturing technique. The techniques presented include powder mixing, sol-gel, synthesis of MICs based on nano-porous silicon (Psi), sputtering, multilayer nano-foils and electrolytically plated carbon nano-materials for nano-thermite applications. These techniques offer enormously different characteristics and, through the variation of various chemical techniques and conditions, a wide range of chemical and energetic properties may be attained. This may give the opportunity for the safe use of MICs as replacements for some conventional energetic materials in various applications, and may also enable us to study the effects when incorporating these MICs into energetic matrixes, as a promising and feasible research field.
Źródło:
Central European Journal of Energetic Materials; 2021, 18, 1; 63--85
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biosynthesis of antibacterial silver nano-particles from Aspergillus terreus
Autorzy:
Singh, P. Shivakumar
Vidyasagar, G. M.
Powiązania:
https://bibliotekanauki.pl/articles/1112999.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Bio-synthesis
Silvernanoparticles
TEM
UV
Opis:
This paper deals with the bio-synthesis of silver nano-particles using a soil fungi. In this work, FTIR examinations indicated that the encountered soil particles actually contained Silver particles, while XRD analysis confirmed the silver was in the nano-crystalline phase. Moreover, the hurried decline of silver (Ag+) ions monitored using UV-visible spectrophotometer, demonstrated that these silver nano-particles formed within 19 minutes. In addition, transmission electron microscopy (TEM) revealed that the synthesized silver nano-particles come in a size ranging between 16-57 nm and have a variety of shapes, including round, rod and uneven. The present study thus concludes that silver nano-particles were actually produced and that these have admirable antibacterial activity. The current study also indicates that increasing concentration increases the rate of reduction and decreases the particle size.
Źródło:
World News of Natural Sciences; 2018, 16; 109-116
2543-5426
Pojawia się w:
World News of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chitosan-based nanocomposites modified with reduced graphene oxide prepared via green synthesis
Autorzy:
Kosowska, K.
Domalik-Pyzik, P.
Jagiełło, J.
Lipińska, L.
Chłopek, J.
Powiązania:
https://bibliotekanauki.pl/articles/284680.pdf
Data publikacji:
2017
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
nanocomposites
graphene oxide
green synthesis
Źródło:
Engineering of Biomaterials; 2017, 20, no. 143 spec. iss.; 59
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evolutionary Algorithm that Designs the DNA Synthesis Procedure
Autorzy:
Michalak, M.
Nowak, R.
Powiązania:
https://bibliotekanauki.pl/articles/308431.pdf
Data publikacji:
2011
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
bioinformatics
gene synthesis
optimum searching
Opis:
Chemical synthesis of nucleotide chains is very erroneous for long sequences. Often a gene is constructed from short fragments joined with the use of complementary helper chains. The number of possible potential solutions for a long gene synthesis is very large, therefore a fast automated search is required. In the presented approach a modified method of long DNA construction is proposed. A computer program that searches for an optimal solution in the space of potential synthesis methods has been developed. This software uses an evolutionary algorithm for global optimization and a hillclimbing algorithm for local optimization. The long DNA construction method was tested on random sequences. The results are very promising. The next step is to perform experiments in a biotechnological wet laboratory involving DNA strand synthesis using the method designed by the presented software.
Źródło:
Journal of Telecommunications and Information Technology; 2011, 4; 50-54
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Robot modelling, perception, and motion synthesis
Autorzy:
Tchoń, K.
Zieliński, C.
Powiązania:
https://bibliotekanauki.pl/articles/384804.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
robot modelling
perception
motion synthesis
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2017, 11, 2; 3-4
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Homogenization and Micro/Nano Source of Starting Powders on Format Ion of the Single YAP Phase
Autorzy:
Michalik, D.
Pawlik, T.
Plewa, J.
Sopicka-Lizer, M.
Powiązania:
https://bibliotekanauki.pl/articles/351720.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
YAP
scintillators
synthesis
polycrystalline ceramics
Opis:
Manufacturing high purity polycrystalline YAlO3 (YAP) ceramics could replace monocrystalline YAP thus recently it is an interesting task for low cost producers of scintillators. The paper presents influence of different source of initial oxide powders (micro/nano powders of Y2O3 and Al2O3) and the method of their homogenization on the formation of a YAP phase. The solid state reaction method was used to prepare YAP powder or ceramic pellets. After preheating, all samples in the form of powders and pellets were heat-treated in the temperature range of 1050-1650 °C. DTA method was applied for examination of the phase crystallization in the tested system. X-ray diffraction method (XRD) was used for characterization of the phase composition. X-ray microanalysis (EDS) was used to control homogeneity in the small areas. Morphology of the resultant samples are presented on SEM pictures. The results show a significant influence of the starting powders on the homogeneity, purity and temperature of formation of the main phase.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 4; 1753-1760
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Przykłady otrzymywania nanocząstek z wykorzystaniem mikrofalowej solwotermalnej syntezy MSS
Examples of the Nanoparticles Produced by Microwave Solvothermal Synthesis (MSS) Route
Autorzy:
Wojnarowicz, J.
Chudoba, T.
Smoleń, D.
Łojkowski, W.
Majcher, A.
Mazurkiewicz, A.
Powiązania:
https://bibliotekanauki.pl/articles/167882.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Ceramiki i Materiałów Budowlanych
Tematy:
nanocząstki
synteza hydrotermalna
synteza solwotermalna
reaktor mikrofalowy
nanoparticles
hydrothermal synthesis
solvothermal synthesis
microwave reactor
Opis:
Proces mikrofalowej syntezy solwotermalnej (Microwave Solvothermal Synthesis, MSS) jest przykładem zastosowania wspomagającego reakcje chemiczne promieniowania mikrofalowego. Grzanie mikrofalowe umożliwia precyzyjne programowanie czasu syntezy. Dzięki temu możliwe jest uzyskiwanie cząstek charakteryzujących się wąskim rozkładem wielkości oraz wysokim stopniem krystaliczności (tzn. niskim udziałem faz amorficznych). Dodatkową zaletą procesu jest znacznie niższa temperatura w porównaniu z technologiami: plazmowymi, zol żel, syntezy z fazy gazowej. W artykule przedstawiono nowe reaktory do realizacji procesów MSS. Podano przykłady syntez hydroksyapatytu, tlenku cynku i tlenku cyrkonu. Wykazano możliwość sterowania właściwościami uzyskiwanych materiałów. Reaktory typu MSS-1 i MSS-2 stwarzają możliwość przemysłowej produkcji nanocząstek.
Microwave solvothermal synthesis (MSS) is an example of microwave assisted wet chemical synthesis process. Microwave heating enables a precise control of the reaction time, fast heating and reducing the thermal gradients. This results in a better crystallinity of the nanoparticles comparing to the precipitation process, and a narrow size distribution. An additional advantage is a reduced synthesis temperature, since no calcination is need. In the paper we presented two new reactors used for the MSS process. We have shown their applications in the synthesis of nanohydroksyapatite ZnO and ZrO2, as well as the enhanced control of their properties possible due to the use of microwaves. The MSS-1 and MSS-2 reactors enable industrial scale production of nanoparticles.
Źródło:
Szkło i Ceramika; 2014, R. 65, nr 6, 6; 8-11
0039-8144
Pojawia się w:
Szkło i Ceramika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ostatnie postępy w syntezie alkaloidów tropanowych i pochodnych tropanu
Recent advances in the synthesis of tropane alkaloids and other tropane derivatives
Autorzy:
Sidorowicz, K.
Kropiwnicki, K.
Łaźny, R.
Powiązania:
https://bibliotekanauki.pl/articles/171941.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
synteza
alkaloidy tropanowe
pochodne tropanów
synteza stereoselektywna
synthesis
tropane alkaloids
tropane derivatives
stereoselective synthesis
Opis:
Tropane alkaloids are a long-known class of compounds possessing an 8-azabicyclo[ 3.2.1]octane skeleton. Many tropane alkaloids posses biological activity (anticholinergic, anti-Parkinsonian, hypotensive), and as such had a significant influence on medicine and played a notable role in the development of organic chemistry [1]. The most known representatives of biologically active tropane alkaloids are: cocaine, atropine, scopolamine, ecgonine, and Bao Gong Teng A. A number of natural tropane alkaloids are chiral compounds, whose preparation in optically active forms is still a big challeng [2]. The biological activity of enantiomers often differs depending on their configurations. Alkaloids are a subject of an intensive research: scopus database contains nearly 200 thousand publications with the word „alkaloid”, and almost 4,500 publications with the phrase „tropane alkaloids” (about half of them have appeared in the last ten years). About 55 papers are devoted to stereoselective synthesis of tropane derivatives in 2000-2015. About half of this concernes stereoselective methods. The organic synthesis of alkaloids has a long history and numerous synthetic approaches to the tropane skeleton have been developed, from the classical synthesis of tropinone by Willstätter at the beginning of the XX century, to more recent developments dealing with asymmetric deprotonation of tropinone with chiral lithium amide bases for the enantioselective synthesis of a range of tropanes [3, 4]. Owing to extensiveness of the field, the current review presents the most interesting, from a synthetic point of view, approaches to tropane derivatives and tropane analogues. Most of the methods of synthesis are long (often several steps), time- and recourses-intensive, and often required elaborate and hardly available starting materials. But there are also notable exceptions, based on the asymmetric deprotonation approach; e.g., from the syntheses of cocaine described in this article, the most efficient one was reported by Lee in 2000 [5]. The concise synthesis (6 steps) gave the unnatural enantiomer of cocaine starting from commercially available tropinone in 78% overall yield. This approach allows to obtain both enantiomers and racemate, by changing type of one reactant only. However, most strategies provide only one enantiomer or racemic mixture of an alkaloid. As can be seen, despite of advances in chemicall science, there is no general way to synthesize majority of the representatives of this group of structurally related compounds.
Źródło:
Wiadomości Chemiczne; 2015, 69, 11-12; 1019-1045
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis of multiple-valued logic networks for FPGA implementation using developmental genetic programming
Autorzy:
Deniziak, S.
Wiśniewski, M.
Wieczorek, K.
Powiązania:
https://bibliotekanauki.pl/articles/114577.pdf
Data publikacji:
2016
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
multiple-valued functions
FPGA
symbolic synthesis
Opis:
This paper presents a method of FPGA-oriented synthesis of multiple-valued logical networks. A multiple-valued network consists of modules connected by multivalued signals. During synthesis the modules are decomposed into smaller ones. For this purpose the symbolic decomposition is applied. Since the decomposition of modules strongly depends on the encoding of multiple-valued inputs and outputs, the result of synthesis depends on the order, in which the consecutive modules are implemented. Experimental results showed that our approach significantly reduces the cost of implementation.
Źródło:
Measurement Automation Monitoring; 2016, 62, 8; 278-281
2450-2855
Pojawia się w:
Measurement Automation Monitoring
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
1-fenylo-2,6-bis(etoksykarbonylometylo)imidazo[1,5-c]-chinazolino-3,5-dion : półprodukt w syntezie poliuretanów
1-phenyl-2,6-bis(ethoxycarbonylmethyl)imidazo[1,5-c]-quinazoline-3,5-dione : an intermediate product in synthesis of polyurethanes
Autorzy:
Hęclik, K.
Szyszkowska, A.
Zarzyka, I.
Powiązania:
https://bibliotekanauki.pl/articles/278346.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Inżynierii Materiałów Polimerowych i Barwników
Tematy:
poliuretany
synteza
imidazochinazolin
polyurethanes
synthesis
imidazoqinazolin
Opis:
W niniejszej pracy podjęto badania w celu wyjaśnienia struktury krystalograficznej 2,6-bis(etoksykarbonylometylo)-1-fenyloimidazo[1,5-c]chinazolino-3,5-dionu (BEFIC). Związek ten jest półproduktem w syntezie poliuretanów liniowych z pierścieniem imidazochinazolinowym. Monokryształ BEFIC tworzy tylko jedna para enancjomerów z pośród 32 możliwych konformerów. Obliczenia kwantowo-mechaniczne cząsteczki BEFIC przeprowadzone w oparciu o Teorię Funkcjonału Gęstości (DFT) z użyciem programu Gaussian wykazały możliwość wzajemnej przemiany konformerów tego związku. Transformacja konformerów BEFIC prowadzi ostatecznie do występowania tylko jednej, najbardziej stabilnej pary enancjomerów, pozwalającej na najlepsze upakowanie cząsteczek w komórce elementarnej.
In the present work, we have undertaken research in order to clarify the crystal structure of 2,6-bis(ethoxycarbonylmethyl)-1-phenylimidazo[1,5-c]quinazoline-3,5-dione. This compound is an intermediate in the synthesis of the linear polyurethanes with imidazoquinazoline ring. Single crystal of 2,6-bis(ethoxycarbonylmethyl)-1-phenylimidazo[1,5-c]quinazoline-3,5-dione is formed by only one pair of enantiomers from among 32 possible conformers. Quantummechanical calculations 2,6-bis(ethoxycarbonylmethyl)-1-phenylimidazo[1,5-c]quinazoline-3,5-dione carried out based on the density functional theory (DFT) using the program Gaussian demonstrated the possibility of the mutual transformations of the conformers. Transformation of 2,6-bis(ethoxycarbonylmethyl)-1-phenylimidazo[1,5-c]quinazoline-3,5-dione conformers ultimately leads to the presence of only one pair of enantiomers. This pair is the most stable and allows the best packing of molecules in the unit cell.
Źródło:
Przetwórstwo Tworzyw; 2017, T. 23, Nr 1 (175), 1 (175); 24-32
1429-0472
Pojawia się w:
Przetwórstwo Tworzyw
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis, Characterization and Compatibility Studies of Poly(DFAMO/NIMMO) with Propellant and PBX Ingredients
Autorzy:
Li, H.
Yang, Y.
Pan, J.
Wang, W.
Pan, R.
Zhu, W.
Powiązania:
https://bibliotekanauki.pl/articles/358094.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
energetic binder
synthesis
characterization
compatibility
PDN
Opis:
Oxetane-based polymers substituted with difluoroamino groups can be used as energetic binders in propellants and polymer-bonded explosives (PBXs). As a novel candidate, poly(3-difluoroaminomethyl-3-methyloxetane/3-nitratomethyl-3-methyloxetane) (PDN) was synthesized and its structure was established. Thermogravimetry (TG) and differential scanning calorimetry (DSC) were employed to investigate its thermal decomposition behaviour. The compatibility between PDN and some common ingredients of propellants and PBXs was evaluated by the DSC method. PDN with good thermal stability was synthesized via a cationic solution polymerization process. Additionally, it has improved compatibility with cyclotetramethylenetetranitramine (HMX), carbon black (C.B.) and lead carbonate (PbCO3) compared with homopoly(3-difluoroaminomethyl-3-methyloxetane) (PDFAMO). PDN could be used as a promising difluoroamino energetic binder in the future.
Źródło:
Central European Journal of Energetic Materials; 2018, 15, 1; 85-99
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling of the Synthesis of 1,1-Diamino-2,2-dinitroethene (DADNE)
Autorzy:
Trzciński, W. A.
Chyłek, Z.
Powiązania:
https://bibliotekanauki.pl/articles/358345.pdf
Data publikacji:
2012
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
DADNE
modelling of the synthesis
kinetics
Opis:
In this work the conditions and kinetics of nitration of 2-methylpyrimidine- 4,6-dione (MPD), which leads to the formation of 1,1-diamino-2,2-dinitroethene (DADNE), are presented. An analysis of literature data enabled us to propose a model and a mathematical formulation of the synthesis of DADNE. The model was verified on the basis of literature data and our own experimental data. The influence of the addition time of nitric acid into a model reactor on temperature and composition of the reaction mixture was investigated. The proposed synthesis model could be useful in a study of the MPD nitration process on a large, laboratory scale.
Źródło:
Central European Journal of Energetic Materials; 2012, 9, 2; 101-117
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-25 z 695

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