Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "carbon ions" wg kryterium: Wszystkie pola


Tytuł:
Simulation of Carbon Ions Interactions with Monocrystalline Silicon Targets
Autorzy:
Bouguerra, A.
Labbani, R.
Powiązania:
https://bibliotekanauki.pl/articles/1402536.pdf
Data publikacji:
2015-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.20.Bh
85.40.Ry
Opis:
In this work, several phenomena related to carbon ion implantation into Si(100) targets were simulated. The investigation was performed using Crystal-TRIM code (crystal-transport and range of ions in matter) under different conditions. In particular, we simulated the carbon profiles with respect to: (i) ions beam (energy, dose, orientation); (ii) substrate (temperature, crystallographic orientation). Two particular cases were taken into account: (i) implantation of 80 keV C⁺ to a fluence of 2.7× 10¹⁷ ion/cm² at room temperature; (ii) implantation of 40 keV C⁺ to a fluence of 6.5× 10¹⁷ ion/cm² at substrate temperature of 400°C. For both cases, we used a tilt angle of 7°. Several results were obtained and compared with the Rutherford backscattering spectroscopy and elastic recoil detection analysis results provided by literature.
Źródło:
Acta Physica Polonica A; 2015, 128, 2B; B-67-B-70
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation and characterization of 4H-SiC JBS diodes irradiated by hydrogen and carbon ions
Autorzy:
Sharma, R. K.
Hazdra, P
Popelka, S.
Powiązania:
https://bibliotekanauki.pl/articles/397767.pdf
Data publikacji:
2015
Wydawca:
Politechnika Łódzka. Wydział Mikroelektroniki i Informatyki
Tematy:
4H-SiC
characterization
JBS diode
PIN diode
simulation
dioda JBS
dioda PIN
symulacje
Opis:
This paper presents the development and application of simulation models for proton and carbon irradiated 4H-SiC junction barrier Schottky (JBS) diodes. Commercial JBS diode chips were irradiated to the identical depth with different doses of hydrogen and carbon ions. The resulting defects were then identified by deep level transient spectroscopy (DLTS). Comprehensive I-V and C-V measurement performed prior to and after ion irradiation was used for calibration of simulation models. Results show that compared to protons, heavier carbon ions introduce more defects with deeper levels in the SiC bandgap and more stable damage. For the first time, the free carrier concentration profile extracted from CV simulations for irradiated JBS diode has been compared with experimental data. The simulation of irradiated JBS diodes exhibit excellent matching with experimental data and can be very useful for the optimization of SiC power devices. Furthermore, it is shown that the developed model can be used for prediction of the effect of ion irradiation on both the static and dynamic characteristic of PiN diode.
Źródło:
International Journal of Microelectronics and Computer Science; 2015, 6, 2; 59-63
2080-8755
2353-9607
Pojawia się w:
International Journal of Microelectronics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of instruments of nuclear physics to the calculation of theoretical dose distributions in various organs of the human body for beams used in hadrontherapy
Autorzy:
Maliszewska, W.
Sękowski, P.
Skwira-Chalot, I.
Powiązania:
https://bibliotekanauki.pl/articles/146972.pdf
Data publikacji:
2016
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
carbon ions
hadrontherapy
hydrogen ions
SRIM
Xeloss
Opis:
The area of interests of nuclear physics are studies of reactions, wherein atomic nuclei of projectile collide with target nuclei. An amount of energy lost by projectile nucleus during its passing through the target is a major issue – it is important to know how charged particles interact with matter. It is possible to afford this knowledge by using theoretical programs that calculate energy loss applying the Bethe-Bloch equation. Hadrontherapy, which is a field of still growing interest, is based on the interactions of charged particles with matter. Therefore, there exists a need of creating a simple model that could be used to the calculation of dose distributions in biological matter. Two programs (SRIM, Xeloss), used to the calculation of energy loss by nuclear physicist, have been adapted to determine the dose distributions in analogues of human tissues. Results of the calculations with those programs for beams used in hadrontherapy (e.g. 1H, 12C) will be compared with experimental data available in references.
Źródło:
Nukleonika; 2016, 61, 1; 19-22
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electronic Energy Loss of the Partially Stripped Boron-Like and Carbon-Like Fast Ions
Autorzy:
Gümüş, H.
Özalp, C.
Köroğlu, A.
Powiązania:
https://bibliotekanauki.pl/articles/2035735.pdf
Data publikacji:
2003-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
34.50.Bw
61.85.+p
Opis:
An analytical formula of the electronic stopping power expression in this study was derived for swift boron-like and carbon-like ions by using first-order perturbation theory and frozen-charge-state model. The Hartree- Fock-Slater determinant was used for the description of the bound electrons attached to ions in the ground state and orbital-screening parameter was determined by variational method. The calculated ground state energies in this study were compared with the results of Clementi-Roetti and they are in good agreement with 5%. It has been observed that the difference of energy loss for boron-like and carbon-like projectiles in a frozen-charge state increases as an atomic number increases. Furthermore, the analytical expression of the effective charge of boron-like and carbon-like projectiles was derived.zapisz i p
Źródło:
Acta Physica Polonica A; 2003, 103, 4; 349-363
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spectrophotometric Analysis of the Kinetic of Pd(II) Chloride Complex Ions Sorption Process from Diluted Aqua Solutions Using Commercially Available Activated Carbon
Autorzy:
Wojnicki, M.
Powiązania:
https://bibliotekanauki.pl/articles/354034.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
palladium
recovery
recycling
adsorption
sorption
chloride ions
spectrophotometry
Opis:
In this paper, results of adsorption kinetic studies of Pd(II) chloride complex ions on activated carbon Organosrob 10 CO are presented. Spectorphotometrical method was applied to investigate the process. Kinetic model was proposed, and fundamental thermodynamic parameters were determined. Proposed kinetic model describes well observed phenomenon in the studied range of concentration of Pd(II) chloride complex ions as well, as concentration of activated carbon.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 4; 2405-2411
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Studies on the production of glucose isomerase by Bacillus licheniformis
Autorzy:
Nwokoro, O.
Powiązania:
https://bibliotekanauki.pl/articles/778827.pdf
Data publikacji:
2015
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
glucose isomerase
carbon sources
nitrogen sources
metal ions
Opis:
This work reports the effects of some culture conditions on the production of glucose isomerase by Bacillus licheniformis. The bacterium was selected based on the release of 3.62 mg/mL fructose from the fermentation of glucose. Enzyme was produced using a variety of carbon substrates but the highest enzyme activity was detected in a medium containing 0.5% xylose and 1% glycerol (specific activity = 6.88 U/mg protein). Media containing only xylose or glucose gave lower enzyme productivies (specific activities= 4.60 and 2.35 U/mg protein respectively). The effects of nitrogen substrates on glucose isomerase production showed that yeast extract supported maximum enzyme activity (specific activity = 5.24 U/mg protein). Lowest enzyme activity was observed with sodium trioxonitrate (specific activity = 2.44 U/mg protein). In general, organic nitrogen substrates supported higher enzyme productivity than inorganic nitrogen substrates. Best enzyme activity was observed in the presence of Mg2+ (specific activity = 6.85 U/mg protein) while Hg2+ was inhibitory (specific activity = 1.02 U/mg protein). The optimum pH for best enzyme activity was 6.0 while optimum temperature for enzyme production was 50oC.
Źródło:
Polish Journal of Chemical Technology; 2015, 17, 3; 84-88
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Usuwanie metali ciężkich z roztworów wodnych z wykorzystaniem aerożeli i kserożeli węglowych
Heavy metal ions removal from aqueous solutions using carbon aerogels and xerogels
Autorzy:
Łużny, R.
Ignasiak, M.
Walendziewski, J.
Stolarski, M.
Powiązania:
https://bibliotekanauki.pl/articles/142876.pdf
Data publikacji:
2014
Wydawca:
Stowarzyszenie Inżynierów i Techników Przemysłu Chemicznego. Zakład Wydawniczy CHEMPRESS-SITPChem
Tematy:
adsorpcja
aerożele węglowe
kserożele węglowe
metale ciężkie
adsorption
carbon aerogels
carbon xerogels
heavy metals
Opis:
Aerożele i kserożele węglowe otrzymano w procesie polikondensacji rezorcyny z formaldehydem w środowisku wodnym z wykorzystaniem wodorotlenku potasu oraz bromku cetylotrimetylowego jako katalizatorów. Zsyntezowane materiały poddano aktywacji, a następnie zbadano ich skuteczność w procesie adsorpcyjnego usuwania jonów metali ciężkich (niklu, miedzi i cynku) z roztworów wodnych. Otrzymane wyniki wskazują na istotny wpływ warunków syntezy, metody aktywacji oraz rodzaju usuwanego jonu na zdolność sorpcyjną badanych materiałów. Skuteczność usuwania niklu, miedzi i cynku z roztworów wodnych z wykorzystaniem kserożelowych i aerożelowych materiałów węglowych jest zbliżona, a w niektórych przypadkach większa, niż skuteczność komercyjnych węgli aktywnych.
Carbon aerogels and xerogels were obtained by polycondensation of resorcinol and formaldehyde in the aqueous solution using potassium hydroxide and cetyltrimethylammonium bromide (CTAB) as the catalyst. Synthesised materials were activated and their effectiveness in adsorption of heavy metals ions (nickel, copper and zinc) from aqueous solutions was tested. Obtained results show essential influence of synthesis conditions, activation method and metal ion kind on adsorption capacity of tested materials. Carbon aerogel and xerogels were characterized by similar or better (in some cases) effectiveness of nickel, copper and zinc ions removal than commercial activated carbons.
Źródło:
Chemik; 2014, 68, 6; 544-553
0009-2886
Pojawia się w:
Chemik
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ pola ultradźwiękowego na adsorpcję kationów kadmu
The Effect of Ultrasonic Field on the Adsorption of Cadmium Ions
Autorzy:
Lach, J.
Okoniewska, E.
Stępniak, L.
Ociepa, E.
Powiązania:
https://bibliotekanauki.pl/articles/1819171.pdf
Data publikacji:
2013
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
pola ultradźwiękowe
adsorpcja kationów
aqueous solution
activated carbon
sewage sludge
metal ions
removal
surface
Opis:
Adsorption on activated carbon is one of the methods applied for removal of heavy metals from water and wastewater contaminated with these elements. Ion exchange is a predominating mechanism in the process of sorption of ions. In case of sorption of heavy metals cations various surface aggregates are formed. Other processes, such as reduction and oxidation, and precipitation in the pores of insoluble compounds (e.g. hydroxides, carbonates) also occur. The processes behind the formation of aggregates with various degrees of resistance have a particular effect on the selectivity of ion exchange on activated carbons. The chemical composition of activated carbon surface – in particular, the presence of oxygen groups capable of ion exchange – shows the most significant effect during adsorption of heavy metals ions. Typically, the surface of the activated carbons produced with the steam-gaseous method has functional groups both of acidic and alkaline character that are capable of exchanging cations as well as anions. Carbon materials with no functional groups can also sorb protons. This is possible due to the fact that dislocated electrons π in the solutions act as Lewis base. There are a number of methods currently being investigated that would allow for improving the efficiency of adsorption of heavy metals. In the presented work the effect of ultrasonic field on the adsorption of cadmium from the model solutions was analyzed. Various configurations of ultrasonic field applied in the process of adsorption were investigated. Ultrasounds were generated in the UP 400S disintegrator. In the first phase the activated carbon in the form of granules was modified with the ultrasonic field of acoustic power density of 42,5 W/cm2or 85,0 W/cm2, at the amplitude of 30 and 60 µm, and at the exposure time of 5, 10, 15 and 20 min. Modified activated carbons were used for sorption of cadmium ions from the solutions at the initial concentrations ranging from 2,24 do 11,2 mg/dm3. The adsorption of cadmium on the activated carbon modified with ultrasounds (at the amplitude of 30 µm and 60 µm) and at the shortest exposure time (i.e. 5 min.) was higher than on the initial activated carbon. The most favorable results were obtained for the activated carbon modified with ultrasonic field with the acoustic power density of 42,5 W/cm3 and the exposure time of 10 min. The efficiency of cadmium adsorption for the highest concentration increased from 50% (the initial activated carbon) to 63%. Also, the work included the analysis of the effect of ultrasonic field on the cadmium solution with the activated carbon in the form of granules in the first phase of static adsorption. In this case, no significant differences in the adsorption capacities were observed. Also, the effect of ultrasounds on the solution used for the adsorption of cadmium did not have an impact on the efficiency of adsorption. In the final phase of the investigations the effect of sonification on the adsorption of cadmium on the powdery activated carbon was analyzed. The control sample was mechanically mixed for 5 min, and the remaining samples were subjected to the ultrasonic field at various amplitudes but with the same exposure time. The efficiency of adsorption combined with ultrasounds was significantly higher. The final concentrations during the adsorption without ultrasounds were in the range of 0,291 to 1,778 mg/dm3 whereas for the adsorption combined with ultrasounds these concentrations ranged from 0,13 to 0,748 mg/dm3.
Źródło:
Rocznik Ochrona Środowiska; 2013, Tom 15, cz. 3; 2142-2157
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Removal of fluoride ions from aqueous medium by adsorption on activated carbon
Usuwanie jonów fluorkowych ze środowiska wodnego w procesie adsorpcji na węglach aktywnych
Autorzy:
Gąsior, D.
Powiązania:
https://bibliotekanauki.pl/articles/297225.pdf
Data publikacji:
2017
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
adsorption
fluoride ions
water purification
activated carbons
adsorpcja
jony fluorkowe
oczyszczanie wody
węgle aktywne
Opis:
Environmental pollution with fluoride ions has been observed to increase with the growth of industrial activity of man and with the expansion of fluorine compounds in agriculture and dental prophylaxis. Hazards involved in the excess of fluorine, especially in the aquatic environment, is generated also in the processes of leaching and erosion of fluorine compounds from minerals which occur naturally in the soil. In a growing number of areas of Poland, especially in groundwater, the highest permissible concentrations of fluoride ions are exceeded; this is especially hazardous because of their high toxicity. The use of activated carbons in the adsorption of fluorides from aqueous solutions was described in many reports of studies on the elimination of such pollutants. Some of the physical and chemical properties of activated carbons are especially desirable in adsorption processes; they include: a well-developed specific surface, high mechanical strength and chemical resistance, ion exchange properties, susceptibility to surface modification enabling improvement of the materials in terms of selectivity to the specific pollutant. The objective of this paper was to investigate the statics and kinetics of fluoride adsorption on the commercially available activated carbons F-100 and WG-12. The study included the surface characterization of the activated carbons tested. The impact of the parameters of the activated carbons tested as well as process parameters (such as the porous structure of carbon, chemical structure of the surface, pH of the adsorption process, initial concentration of the pollutant) on the efficiency of the fluoride removal from aqueous solutions was also investigated. The fluoride content in samples of model solutions was analyzed by the potentiometric method using a fluoride ion selective electrode. The adsorption kinetics was conformable with the pseudo-second order model. The process equilibrium was reached after 1 h and 2 h for F-100 and WG-12, respectively. It was found that adsorption efficiencies for both activated carbons are strongly related to the pH of the model solution, as well as to the initial concentration of the fluorides in the model solution. Ion exchange, which strongly depends on the pH of the model solution, was one of the mechanisms controlling the course of the adsorption process. Fluoride adsorption on activated carbons was described using Freundlich isotherms. High correlation coefficients (> 0.96) were obtained for the isotherms, which seems to indicate that the course of the process was conformable with the Freundlich model assumptions.
Zanieczyszczenie środowiska jonami fluorkowymi wzrasta wraz z rozwojem przemysłowej działalności człowieka i coraz powszechniejszym stosowaniem związków fluoru w rolnictwie oraz profilaktyce stomatologicznej. Zagrożenie wynikające ze zbyt dużych zawartości fluoru, zwłaszcza w środowisku wodnym, ma swoje źródło również w procesach wypłukiwania i wymywania związków fluoru z naturalnie występujących w glebie minerałów. W Polsce odnotowuje się coraz więcej obszarów, gdzie, głównie w wodach podziemnych, występują lokalne przekroczenia najwyższych dopuszczalnych stężeń jonów fluorkowych, co jest szczególnie niebezpieczne z uwagi na ich wysoką toksyczność. Zastosowanie węgli aktywnych w procesach adsorpcji fluorków z roztworów wodnych jest obiektem wielu prac badawczych dotyczących sposobów usuwania tych zanieczyszczeń. Węgle aktywne przejawiają korzystne właściwości fizykochemiczne istotne w procesach adsorpcyjnych, takie jak rozwinięta powierzchnia właściwa, wysoka wytrzymałość mechaniczna i chemiczna, właściwości jonowymienne, podatność na modyfikację powierzchni umożliwiającą uzyskanie większej selektywności tych materiałów względem określonego rodzaju usuwanego zanieczyszczenia. Celem pracy jest zbadanie statyki i kinetyki procesu adsorpcji fluorków na komercyjnie dostępnych węglach aktywnych F-100 i WG-12. W toku przeprowadzonych badań dokonano również charakterystyki powierzchni analizowanych węgli aktywnych. Oceniono wpływ parametrów badanych węgli aktywnych i parametrów procesowych (takich jak struktura porowata węgla, chemiczna budowa powierzchni, pH procesu adsorpcji, stężenie początkowe substancji zanieczyszczającej) na skuteczność usuwania fluorków z roztworów wodnych. Zawartość fluorków w próbkach roztworów modelowych analizowano metodą potencjometryczną z użyciem jonoselektywnej elektrody fluorkowej. Kinetyka adsorpcji przebiegała zgodnie z modelem pseudodrugiego rzędu, a równowaga procesu ustaliła się po czasie 1 h w przypadku węgla F-100 oraz 2 h dla węgla WG-12. Stwierdzono, iż skuteczności adsorpcji obu węgli są silnie związane z wartością pH roztworu, z którego zachodził proces, jak również ze stężeniem początkowym fluorków w roztworze modelowym. Jednym z mechanizmów regulujących przebieg procesu adsorpcji był mechanizm wymiany jonowej, silnie uzależniony od odczynu roztworu modelowego. Adsorpcja fluorków na węglach aktywnych została opisana za pomocą izoterm Freundlicha. Opierając się na uzyskanych wysokich współczynnikach korelacji wykreślonych izoterm (> 0,96), można przypuszczać, iż proces przebiegał zgodnie z założeniami modelu Freundlicha.
Źródło:
Inżynieria i Ochrona Środowiska; 2017, 20, 2; 185-197
1505-3695
2391-7253
Pojawia się w:
Inżynieria i Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nano sized carbonized waste biomass for heavy metal ion remediation
Autorzy:
Mahajan, Garima
Sud, Dhiraj
Powiązania:
https://bibliotekanauki.pl/articles/779542.pdf
Data publikacji:
2014
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
nitrogenous waste materials
carbon
heavy metal ions
kinetic studies
Delbergia sisso pods
Opis:
Utilization of agricultural waste material with approach to enhance the heavy metal remediation properties by carbonizing the biomass at nano size particles has been explored in present investigation from aqueous solutions. In this study the lignocellulosic, nitrogenous agricultural waste biomass Delbergia sissoo pods (DSP) has been tried for sequestering of Cd (II), Pb (II) and Ni (II) metal ions from aqueous solutions. Batch experiments were performer for removal of targeted metal ions keeping in consideration the preliminary affecting parameters such as effect of adsorption dose, pH, initial metal ion concentration, stirring speed and contact time. The sorption studies were analyzed by using, Freundlic isotherm and Langmuir isotherm models. The kinetics of the process was evaluated by pseudo pseudo-fi rst order and pseudo second order kinetic models. Studies reveal that the equilibrium was achieved with in 30 min of the contact time at optimized parameters. Analytical studies of biosorbent were done by means of FT-IR, SEM and XRD. Desorption experiments were carried out using HCl solution with a view to regenerate the spent adsorbent and to recover the adsorbed metal ions.
Źródło:
Polish Journal of Chemical Technology; 2014, 16, 4; 6-13
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies