| 1. |
-
Advanced Materials for Agriculture, Food and Environmental Safety
- 2014
-
Samlingsverk (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
- The levels of toxic and microbial contamination in the food and environment are influenced by harvesting or slaughtering technologies and by the processes applied during food manufacture. With current cultivation methods, it is impossible to guarantee the absence of pesticides and pathogenic microorganisms in raw foods, both of plant and animal origin. Widespread and increasing incidence of foodborne diseases and the resulting social and economic impact on the world population have brought food and environmental safety to the forefront of ecological safety and public health concerns. The emerging field of advanced materials based on functional architectures offers potential solutions to some of the key performance challenges along with the improved sensitivity, longevity, stability, miniaturization and ruggedness, while reducing complexity and production cost. The overall purpose of this book is to generate new solutions to the technical challenges in easy and rapid detections of food toxicants, microorganisms and environmental pollutants. The book focuses on the role of advanced materials in the food, water and environmental applications. The monitoring of harmful organisms and toxicants in water, food and beverages is mainly discussed in the respective chapters. The senior contributors write on the following topics:Layered double hydroxides and environmentCorrosion resistance of aluminium alloys of silanesNew generation material for the removal of arsenic from waterPrediction and optimization of heavy clay products qualityEnhancement of physical and mechanical properties of fiberEnvironment friendly acrylates laticesNanoparticles for trace analysis of toxinsRecent development on gold nanomaterial as catalyst Nanosized metal oxide based adsorbents for heavy metal removalPhytosynthesized transition metal nanoparticles- novel functional agents for textilesKinetics and equilibrium modelingMagnetic nanoparticles for heavy metal removalPotential applications of nanoparticles as antipathogensGas barrier properties of biopolymer based nanocomposites: Application in food packingApplication of zero-valent iron nanoparticles for environmental clean upEnvironmental application of novel TiO2 nanoparticles
|
|
| 2. |
|
|
| 3. |
- Asghar, M., et al.
(författare)
-
Characterization of deep level defects in sublimation grown p-type 6H-SiC epilayers by deep level transient spectroscopy
- 2012
-
Ingår i: Physica B: Condensed Matter. - : Elsevier. - 0921-4526.
-
Konferensbidrag (refereegranskat)abstract
- In this study deep level transient spectroscopy has been performed on boron-nitrogen co-doped 6H-SiC epilayers exhibiting p-type conductivity with free carrier concentration (N-A-N-D)similar to 3 x 10(17) cm(-3). We observed a hole H-1 majority carrier and an electron E-1 minority carrier traps in the device having activation energies E-nu + 0.24 eV, E-c -0.41 eV, respectively. The capture cross-section and trap concentration of H-1 and E-1 levels were found to be (5 x 10(-19) cm(2), 2 x 10(15) cm(-3)) and (1.6 x 10(-16) cm(2), 3 x 10(15) cm(-3)), respectively. Owing to the background involvement of aluminum in growth reactor and comparison of the obtained data with the literature, the H-1 defect was identified as aluminum acceptor. A reasonable justification has been given to correlate the E-1 defect to a nitrogen donor.
|
|
| 4. |
- Asghar, M., et al.
(författare)
-
Study of deep level defects in doped and semi-insulating n-6H-SiC epilayers grown by sublimation method
- 2012
-
Ingår i: Physica B: Condensed Matter. - : Elsevier. - 0921-4526.
-
Konferensbidrag (refereegranskat)abstract
- Deep level transient spectroscopy (DLTS) is employed to study deep level defects in n-6H-SiC (silicon carbide) epilayers grown by the sublimation method. To study the deep level defects in n-6H-SiC, we used as-grown, nitrogen doped and nitrogen-boron co-doped samples represented as ELS-1, ELS-11 and ELS-131 having net (N-D-N-A) similar to 2.0 x 10(12) cm(-3), 2 x 10(16) cm(-3) and 9 x 10(15) cm(3), respectively. The DLTS measurements performed on ELS-1 and ELS-11 samples revealed three electron trap defects (A, B and C) having activation energies E-c - 0.39 eV, E-c - 0.67 eV and E-c - 0.91 eV, respectively. While DLTS spectra due to sample ELS-131 displayed only A level. This observation indicates that levels B and C in ELS-131 are compensated by boron and/or nitrogen-boron complex. A comparison with the published data revealed A, B and C to be E-1/E-2, Z(1)/Z(2) and R levels, respectively.
|
|
| 5. |
- Beshkova, Milena, et al.
(författare)
-
Properties of 3C-SiC Grown by Sublimation Epitaxy on Different Type of Substrates
- 2010
-
Ingår i: Materials Science Forum, Vols. 645-648. - : Transtec Publications; 1999. ; , s. 183-186
-
Konferensbidrag (refereegranskat)abstract
- 3C-SiC layers have been grown by using sublimation epitaxy at a temperature of 2000 degrees C, on different types of on-axis 6H-SiC(0001) substrates. The influence of the type of substrate on the morphology of the layers investigated by Atomic Force Microscopy (AFM) is discussed. Stacking faults are studied by reciprocal space map (RSM) which shows that double positions domains exists.
|
|
| 6. |
- Beshkova, Milena, et al.
(författare)
-
Sublimation epitaxy of 3C-SiC grown at Si- and C-rich conditions
- 2012
-
Ingår i: Vacuum. - : Elsevier. - 0042-207X .- 1879-2715. ; 86:10, s. 1595-1599
-
Tidskriftsartikel (refereegranskat)abstract
- 3C-SiC layers have been grown by using sublimation epitaxy at a source temperature of 2000 degrees C, under vacuum conditions (andlt;10(-5) mbar) on well oriented (on-axis) 6H-SiC (0001) substrates. Close space sublimation growth geometry has been used in a RF-heated furnace employing high-purity graphite crucible with a possibility to change the growth environment from Si vapor-rich to C vapor-rich. The optical microscopy in transmission mode reveals continuous 3C-domains for 3C-SiC with less than 0.4% 6H-inclusions for the layer grown at Si-rich conditions, and separate 3C-SiC domains for the layer grown at C-rich conditions. The type of 6H-inclusions for layers with continuous domain structure investigated by Atomic Force Microscopy (AFM) is discussed. 2Theta-omega scan shows 0006 and 111 peaks coming from the substrate and the layer, respectively with a higher intensity of the 111 peak for 3C-SiC grown at Si-rich conditions which is related with the continuous character of the 3C-SiC domains.
|
|
| 7. |
- Eriksson, Jens, et al.
(författare)
-
The influence of substrate morphology on thickness uniformity and unintentional doping of epitaxial graphene on SiC
- 2012
-
Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 100:24, s. 241607-
-
Tidskriftsartikel (refereegranskat)abstract
- A pivotal issue for the fabrication of electronic devices on epitaxial graphene on SiC is controlling the number of layers and reducing localized thickness inhomogeneities. Of equal importance is to understand what governs the unintentional doping of the graphene from the substrate. The influence of substrate surface topography on these two issues was studied by work function measurements and local surface potential mapping. The carrier concentration and the uniformity of epitaxial graphene samples grown under identical conditions and on substrates of nominally identical orientation were both found to depend strongly on the terrace width of the SiC substrate after growth.
|
|
| 8. |
- Gavryushin, V., et al.
(författare)
-
Examination of Photoluminescence Temperature Dependencies in N-B Co-doped 6H-SiC
- 2014
-
Ingår i: IOP Conference Series. - : Institute of Physics Publishing (IOPP). - 1757-8981 .- 1757-899X. ; 56:1, s. 012003-
-
Tidskriftsartikel (refereegranskat)abstract
- Two overlapping photoluminescent (PL) bands with a peaks (half-width) at 1.95 eV (0.45 eV) and 2.15 eV (0.25 eV), correspondingly at 300 K, are observed in heavily B-N co-doped 6H-SiC epilayers under high-level excitation condition. The low energy band dominates at low temperatures and decreases towards 300 K which is assigned to DAP emission from the nitrogen trap to the deep boron (dB) with phonon-assistance. The 2.15 eV band slightly increases with temperature and becomes comparable with the former one at 300 K. We present a modelling comprising electron de-trapping from the N-trap, i.e. calculating trapping and de-trapping probabilities. The T-dependence of the 2.15 eV band can be explained by free electron emission from the conduction band into the dB center provided by similar phonon-assistance
|
|
| 9. |
- Grivickas, V., et al.
(författare)
-
Carrier lifetimes and influence of in-grown defects in N-B Co-doped 6H-SiC
- 2014
-
Ingår i: IOP Conference Series. - : Institute of Physics Publishing (IOPP). ; 56:1, s. 012004-
-
Konferensbidrag (refereegranskat)abstract
- The thick N-B co-doped epilayers were grown by the fast sublimation growth method and the depth-resolved carrier lifetimes have been investigated by means of the free-carrier absorption (FCA) decay under perpendicular probe-pump measurement geometry. In some samples, we optically reveal in-grown carbon inclusions and polycrystalline defects of substantial concentration and show that these defects slow down excess carrier lifetime and prevent donor-acceptor pair photo luminescence (DAP PL). A pronounced electron lifetime reduction when injection level approaches the doping level was observed. It is caused by diffusion driven non-radiative recombination. However, the influence of surface recombination is small and insignificant at 300 K.
|
|
| 10. |
- Gulbinas, Karolis, et al.
(författare)
-
Raman Scattering and Carrier Diffusion Study in Heavily Co-doped 6H-SiC Layers
- 2014
-
Ingår i: IOP Conference Series. - : Institute of Physics Publishing (IOPP). - 1757-8981 .- 1757-899X. ; 56:1, s. 012005-
-
Tidskriftsartikel (refereegranskat)abstract
- Thick 6H-SiC epilayers were grown using the fast sublimation method on low-off-axis substrates. They were co-doped with N and B impurities of ≈1019 cm−3 and (41016–51018) cm−3 concentration, respectively. The epilayers exhibited donor-acceptor pair (DAP) photoluminescence. The micro-Raman spectroscopic study exposed a compensated n-6H-SiC epilayer of common quality with some 3C-SiC inclusions. The compensation ratio of B through 200 μm thick epilayer varied in 20-30% range. The free carrier diffusivity was studied by transient grating technique at high injection level. The determined ambipolar diffusion coefficient at RT was found to decrease from 1.15 cm2/s to virtually 0 cm2/s with boron concentration increasing by two orders.
|
|
