| 51. |
- KOPNICZKY, J, et al.
(författare)
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MEV-ION-INDUCED DEFECTS IN ORGANIC-CRYSTALS
- 1995
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Ingår i: RADIATION MEASUREMENTS. - : PERGAMON-ELSEVIER SCIENCE LTD. - 1350-4487. ; 25:1-4, s. 47-50
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- We present scanning force microscope images of crater-like defects induced by MeV atomic ions incident on single-crystal L-valine surfaces. For grazing incidence ions, the craters are elongated along the ion azimuth of incidence and are followed by raised
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| 52. |
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| 53. |
- Kuznetsov, A. Y., et al.
(författare)
-
Self-interstitial migration during ion irradiation of boron delta-doped silicon
- 2000
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Ingår i: Materials Science in Semiconductor Processing. - 1369-8001 .- 1873-4081. ; 3:4, s. 279-283
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Tidskriftsartikel (refereegranskat)abstract
- Boron delta layers in silicon, grown by molecular beam epitaxy and characterized by the secondary ion mass spectrometry, have been employed to investigate the migration of silicon self-interstitials during irradiation with MeV protons in the 500-850 degreesC temperature range. After growth, the samples were thinned from the backside to a thickness that made them transparent for the proton energies used. As a result, the generation rate of point defects can be considered as essentially uniform throughout the samples. However: the evolution of the boron profiles is almost identical to that observed after injection of self-interstitials caused by thermal oxidation of the samples at elevated temperature. This strongly indicates that the surface acts as a reflective boundary for the migrating self-interstitials or/ and an efficient sink for mobile vacancies. Furthermore, higher value of interstitial supersaturation in the near-surface region in proton-irradiated samples is consistent with experimentally detected depth dependence for immobile fraction in boron clusters. Then, activation energy of boron mobilization, (0.9 +/- 0.4) eV, was attributed to the dissociation of boron clusters.
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| 54. |
- Lalita, J, et al.
(författare)
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Defect evolution in MeV ion-implanted silicon
- 1996
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Ingår i: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS. - : ELSEVIER SCIENCE BV. - 0168-583X. ; 120:1-4, s. 27-32
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Lightly doped silicon samples of both n- and p-type, have been implanted with low doses of H, B and Si ions using energies between 1 and 6 MeV. The resulting electrically active point defects were characterized by deep level transient spectroscopy (DLTS)
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| 55. |
- Luo, T., et al.
(författare)
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Combined effect of Pt and Walloying elements on Ni-silicide formation
- 2018
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Ingår i: Journal of Applied Physics. - : AMER INST PHYSICS. - 0021-8979 .- 1089-7550. ; 123:12
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Tidskriftsartikel (refereegranskat)abstract
- A combinatorial study of the combined effect of Pt and W on Ni silicide formation is performed. Ni(Pt, W) films with thickness and composition gradients were prepared by a co-deposition composition spread technique using sputtering deposition from Pt, W, and Ni targets. The deposited Ni(Pt, W) films were characterized by X-ray diffraction, X-ray reflectivity, Rutherford backscattering, and atom probe tomography. The maximum content of alloying elements is close to 27 at. %. Simulations of the thickness and composition were carried out and compared with experimental results. In situ X-ray diffraction and atom probe tomography were used to study the phase formation. Both additive alloying elements (Pt + W) slow down the Ni consumption and the effect of W is more pronounced than the one of Pt. Regarding the effect of alloying elements on Ni silicides formation, three regions could be distinguished in the Ni(Pt, W)/Si wafer. For the region close to the Ni target, the low contents of alloying elements (Pt + W) have little impact on the phase sequence (delta-Ni2Si is the first silicide and NiSi forms when Ni is entirely consumed) but the kinetics of silicide formation slows down. The region close to the Pt target has high contents of (Pt + W) and is rich in Pt and a simultaneous phase formation of delta-Ni(2)Sii and NiSi is observed. For the high (PtthornW) contents and W-rich region, NiSi forms unexpectedly before delta-Ni2Si and the subsequent growth of delta-Ni2Si is accompanied by the NiSi consumption. When Ni is entirely consumed, NiSi regrows at the expense of delta-Ni2Si.
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| 56. |
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| 57. |
- Morvan, E, et al.
(författare)
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Damage reduction in channeled ion implanted 6H-SiC
- 2000
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Ingår i: SILICON CARBIDE AND RELATED MATERIALS - 1999 PTS, 1 & 2. ; , s. 893-896
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Konferensbidrag (refereegranskat)abstract
- We compare damage effects of “random” (off-axis) and [0001] aligned implants of 1.5 MeV Al into 6H-SiC. Both channeled and random equivalent SIMS profiles have been used to adjust model parameters of the simulator. Depth resolved Raman measurements show that at ion doses below similar to 5x10(14) cm(-2), the integral damage is reduced by a factor of similar to2.5 for the channeled implant. This confirms the corresponding reduction of defect concentrations predicted by simulations.
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| 58. |
- Rud, Bjarne, et al.
(författare)
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Metabolic and mechanical involvement of arms and legs in simulated doule pole skiing
- 2014
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Ingår i: Scandinavian Journal of Medicine and Science in Sports. - : Wiley. - 0905-7188 .- 1600-0838. ; 24:6, s. 913-919
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Tidskriftsartikel (refereegranskat)abstract
- We evaluated arm and leg work rate and metabolism during double pole ergometer skiing. Thermodilution arm and leg blood flow was determined together with the arterial to venous difference for oxygen, while the work rate was assessed in eight male recreational skiers [24 (SD 7) years]. When work rate increased from 82 (SE 4) to 117 (7) W, leg power increased by 43% (enhanced vertical force and displacement of the body). The elbow angle tended to increase [from 71 (11.3)° to 75 (10.9)°; P = 0.07] and arm oxygen uptake increased by 20 (5)% [from 0.65 (0.07) to 0.78 (0.08) L/min; P < 0.05] because two-arm blood flow increased [from 5.4 (0.6) to 6.3 (0.7) L/min; P < 0.05] with no significant change in oxygen extraction [from 59 (2.3)% to 60 (1.9)%] accompanied with net arm lactate and potassium release. In contrast, two-leg blood flow [from 5.8 (0.5) to 8.0 (0.5) L/min] and oxygen extraction [from 67 (1.3)% to 75 (1.5)%] increased (P < 0.05), resulting in a 53 (8)% increase in leg oxygen uptake [from 0.82 (0.06) to 1.24 (0.07) L/min; P < 0.05]. In conclusion, during double poling on an ergometer, arm muscle metabolism and work rate increase only marginally and an increase in work intensity is covered mainly by the leg muscles.
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| 59. |
- Thiel, Tomas, et al.
(författare)
-
Secondary stimulation from Bacillus Calmette-Guerin induced macrophages induce nitric oxide independent cell-death in bladder cancer cells
- 2014
-
Ingår i: Cancer Letters. - : Elsevier BV. - 0304-3835 .- 1872-7980. ; 348:1-2, s. 119-125
-
Tidskriftsartikel (refereegranskat)abstract
- The anti-tumour mechanisms following Bacillus Calmette-Guerin (BCG) treatment of bladder-cancer remain largely unknown. Previous studies have shown involvement of nitric-oxide (NO) formation in the BCG-mediated effect. We analyzed the effects of macrophage secreted factors (MSFs) from BCG-stimulated RAW264.7 cells on the bladder-cancer cell line MBT2. Direct treatment with BCG did not induce NO in MBT2-cells whereas supernatant from BCG-stimulated macrophages increased NOS2 mRNA and protein expression, NO concentrations and cell-death. Blocking NO-synthesis with the NOS-inhibitor L-NAME did not affect levels of cell-death suggesting cytotoxic pathways involving other signalling molecules than NO. Several such candidate genes were identified in a microarray.
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| 60. |
- Thiel, Tomas, et al.
(författare)
-
Secondary stimulation from Bacillus Calmette-Guérin induced macrophages upregulatesNOS2 protein in bladder cancer cells
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Treatment with Bacillus Calmette-Guérin (BCG) bladder instillations is an established treatment modality for superficial urinary bladder cancer and carcinoma in situ (CIS), but the anti-tumor mechanisms following BCG-instillations remain largely unknown. Previous data show increased nitric oxide (NO) concentrations in the urinary bladder from patients treated with BCG suggesting that NO-formation may be involved in the BCG-mediated effect. Using immunohistochemistry we have previously shown nitric oxide synthase 2 (NOS2/iNOS) protein expression in both immune cells and in urothelial cells in bladder cancer patient biopsies. In this study we analysed the influence of macrophage- (RAW 264.7) secreted factors on NO production by stimulating urothelial carcinoma cells (MBT2) with supernatant from BCG-treated macrophages as well as supernatant from untreated macrophages. Using real-time PCR, western blot and chemiluminescence, we found no effect of BCG when added straight to the culture medium of urothelial carcinoma cells. However, when 40% of the culture medium of the bladder cancer cells was substituted with supernatant from BCGstimulated macrophages, we found increased NOS2 mRNA and protein expression as well as increased levels of NO. In addition we found increased cell death only in bladder cancer cells stimulated with supernatant from BCG-treated macrophages, as visualized by cell cycle analysis and PARP cleavage. These results suggest that simultaneous targeting of the microenvironment and subsequent stimulation of adaptive responses can improve conventional BCG-therapy.
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| 61. |
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| 62. |
- Violina, G. N., et al.
(författare)
-
Photoelectric properties of p(+)-n junctions based on 4H-SiC ion-implanted with aluminum
- 2002
-
Ingår i: Semiconductors (Woodbury, N.Y.). - : Pleiades Publishing Ltd. - 1063-7826 .- 1090-6479. ; 36:6, s. 706-709
-
Tidskriftsartikel (refereegranskat)abstract
- The photoelectric properties of p(+)-n junctions that were based on 4H-SiC ion-implanted with aluminum and were formed in lightly doped n-type epitaxial layers grown by chemical vapor deposition were studied. It is shown that such photodetectors combine in full measure the advantages of photostructures formed on the basis of Schottky barriers and epitaxial p-n junctions. The results of the theoretical calculation of spectral characteristics of ion-implanted photodetectors are in good agreement with experimental data. The structures feature an efficiency of collection of nonequilibrium charge carriers close to 100% in the spectral range of the photon energies of 3.5-4.25 eV.
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| 63. |
- Violina, G. N., et al.
(författare)
-
Silicon carbide detectors of high-energy particles
- 2002
-
Ingår i: Semiconductors (Woodbury, N.Y.). - : Pleiades Publishing Ltd. - 1063-7826 .- 1090-6479. ; 36:6, s. 710-713
-
Tidskriftsartikel (refereegranskat)abstract
- The results of studying 4H-SiC p(+)-n junctions ion-implanted with aluminum as detectors of high-energy particles are reported. The junctions were formed in SiC epitaxial films grown by chemical vapor deposition. The concentration of uncompensated donors was (3-5) x 10(15) cm(-3), and the charge-carrier diffusion length was L-p = 2.5 mum. The detectors were irradiated with 4.8-5.5-MeV alpha particles at 20degreesC. The efficiency of collection of the induced charge was as high as 0.35. The possibilities of operating SiC detectors at elevated temperatures (similar to500degreesC) are analyzed.
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