Deformation behavior of Cu-composites processed by HPT Krämer, L; Wurster, S; Pippan, R
IOP conference series. Materials Science and Engineering,
08/2014, Letnik:
63, Številka:
1
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
Deformation behavior of two phase materials with High-Pressure Torsion (HPT) was investigated on the basis of Cu-composites. As second phases Fe, W and yttria were used. The deformation behavior in ...the HPT-process differs due to their different mechanical properties and the ratio of Cu and the second phase. A large benefit of deforming two-phase materials is the homogenous nanocrystalline microstructure with smaller achievable grain sizes than in single phase materials subjected to HPT. Attention is given to development of hardness as a function of the applied strain, the chemical composition at different radii and the obtained microstructure. Tensile tests provide additional information about strength.
Display omitted
•Wide variety of PV system configurations analyzed (strings with 10–20 modules, up to 40 strings in parallel).•Effect of real IV characteristics of monocrystalline and amorphous ...modules vs. one-diode model evaluated.•The modeling reveals that the relative mismatch loss is limited to L<1% for most common PV installations.•Thin film technologies with lower efficiency benefit from their lower fill factor; show lower mismatch losses.•The found robustness by design of PV systems questions the requirement of expensive power optimizers.
The effects of current mismatch and shading on the power output of single photovoltaic (PV) modules are well analyzed, but only few investigations address mismatch losses at a PV system level that also limit the annual energy yield. The simple question, what happens if PV strings with different numbers of modules are connected in parallel, has not yet been discussed in detail. In case of strings with unequal module count, the system builder must decide whether to use inverters with multiple maximum power point (MPP) trackers, module-power optimizers, or to shorten all strings for balancing the system. Our findings from this study open a new option. The numerical modeling of PV systems with strings of different length in parallel to several others which have an equal module count renders mismatch losses below 1% for most system configurations. For configurations where one string is one module shorter than the others, the mismatch losses fall below 0.5%. Therefore strings with unequal length may favorably connect to a cost-effective single-MPP inverter without causing significant energy yield losses. Moreover, typical thin film PV modules are less sensitive to mismatch than crystalline silicon based ones.
The fracture resistance of technically pure W with pre-deformed and recrystallized microstructures was tested in a temperature range of ambient to 700 °C. To account for the impact of microstructure ...anisotropy, samples with different specimen orientations were investigated. Room temperature tests were carried out in a scanning electron microscope and at elevated temperatures in a vacuum furnace. Both, microstructure and testing temperature significantly influence the fracture resistance of W and a strong dependence of the crack propagation resistance on the crack plane orientation was found. Pre-deformation of the testing material increases the fracture resistance in terms of the crack initiation toughness but shortens the measurable crack resistance curve (R-curve). Testing at elevated temperatures results in higher initiation toughness for both states, pre-deformed and recrystallized; however, only the recrystallized structure shows an R-curve behavior for the used sample geometry.
Background and purpose:
Substance P (SP) and calcitonin gene‐related peptide (CGRP) released from capsaicin‐sensitive sensory nerves induce local neurogenic inflammation; somatostatin exerts systemic ...anti‐inflammatory actions presumably via sst4/sst1 receptors. This study investigates the effects of a high affinity, sst4‐selective, synthetic agonist, J‐2156, on sensory neuropeptide release in vitro and inflammatory processes in vivo.
Experimental approach:
Electrically‐induced SP, CGRP and somatostatin release from isolated rat tracheae was measured with radioimmunoassay. Mustard oil‐induced neurogenic inflammation in rat hindpaw skin was determined by Evans blue leakage and in the mouse ear with micrometry. Dextran‐, carrageenan‐ or bradykinin‐induced non‐neurogenic inflammation was examined with plethysmometry or Evans blue, respectively. Adjuvant‐induced chronic arthritis was assessed by plethysmometry and histological scoring. Granulocyte accumulation was determined with myeloperoxidase assay and IL‐1β with ELISA.
Key results:
J‐2156 (10–2000 nM) diminished electrically‐evoked neuropeptide release in a concentration‐dependent manner. EC50 for the inhibition of substance P, CGRP and somatostatin release were 11.6 nM, 14.3 nM and 110.7 nM, respectively. J‐2156 (1–100 μg kg−1 i.p.) significantly, but not dose‐dependently, inhibited neurogenic and non‐neurogenic acute inflammatory processes and adjuvant‐induced chronic oedema and arthritic changes. Endotoxin‐evoked myeloperoxidase activity and IL‐1β production in the lung, but not IL‐1β‐ or zymosan‐induced leukocyte accumulation in the skin were significantly diminished by J‐2156.
Conclusions and implications:
J‐2156 acting on sst4 receptors inhibits neuropeptide release, vascular components of acute inflammatory processes, endotoxin‐induced granulocyte accumulation and IL‐1β synthesis in the lung and synovial and inflammatory cells in chronic arthritis. Therefore it might be a promising lead for the development of novel anti‐inflammatory drugs.
British Journal of Pharmacology (2006) 149, 405–415. doi:10.1038/sj.bjp.0706876
Purpose: The CyberKnife™ compensates translational target motion by moving the beams synchronously. While the system was found to operate with sub‐millimeter accuracy in phantoms, determining the ...clinical accuracy is challenging. Measuring the delivered dose distribution inside a patient is impractical. Hence an analysis of treatment data is typically used to estimate residual errors. Methods: We implant 3‐5 fiducials for target tracking and treat liver tumors in 3‐5 fractions with 45Gy at 80% to the PTV (CTV+3mm). Patients are aligned based on X‐ray images in expiration breath hold. During delivery, X‐ray images are acquired every 60‐90s, and the translational and rotational misalignment is computed. We grouped this data into 10 respiratory phases. The mean misalignment for each phase was used to simulate the translation and rotation of the target with respect to the alignment center. The resulting dose distribution was computed and compared to the planned dose. Additionally, the quality of motion prediction was evaluated. Results: We analyzed 5 cases with a total of 17 fractions. The maximal target motion per fraction ranged from 9.2mm to 25.7mm (3D trajectory). The mean error for each patient ranged from ‐0.76/‐0.01/‐ 0.32mm to 0.35/0.17/0.10mm (Translation IS/LR/AP) and ‐0.94/‐0.82/‐2.07 degrees to 0.24/1.95/2.36 degrees (Rotation roll/pitch/yaw). The dose simulation showed point dose difference for each patient ranging from ‐ 0.10Gy to ‐0.76Gy (Mean) and ‐1.13Gy to ‐5.05Gy (Max). The resulting reduction in coverage ranged from 0.37% to 4.19% (PTV) and ‐0.43% to +0.94% (CTV). Finally, the mean prediction error over all fractions was 0.33mm. Conclusions: We demonstrated that while maximum point dose differences can be considerable, the coverage of the CTV is maintained even in the presence of substantial respiratory motion. The results indicate that the standard 3mm system uncertainty margin can account for errors due to rotation and deformation during robotic radiosurgery for tumors in the liver.
Metal matrix composites reinforced by nanocarbon materials, such as carbon nanotubes or nanodiamonds, are very promising materials for a large number of functional and structural applications. Carbon ...nanotubes and nanodiamonds-reinforced metal matrix nanocomposites with different concentrations of the carbon phase were processed by high-pressure torsion deformation and the evolving nanostructures were thoroughly analyzed by electron microscopy. Particular emphasis is placed on the thermal stability of the nanocarbon reinforced metal matrix composites, which is less influenced by the amount of added nanocarbon reinforcements than by the nanocarbon reinforcement type and its distribution in the metal matrix.
Display omitted
Tungsten materials are candidates for plasma-facing components for the International Thermonuclear Experimental Reactor and the DEMOnstration power plant because of their superior thermophysical ...properties. Because these materials are not common structural materials like steels, knowledge and strategies to improve the properties are still under development. These strategies discussed here, include new alloying approaches and microstructural stabilization by oxide dispersion strengthened as well as TiC stabilized tungsten based materials. The fracture behavior is improved by using tungsten laminated and tungsten wire reinforced materials. Material development is accompanied by neutron irradiation campaigns. Self-passivation, which is essential in case of loss-of-coolant accidents for plasma facing materials, can be achieved by certain amounts of chromium and titanium. Furthermore, modeling and computer simulation on the influence of alloying elements and heat loading and helium bombardment will be presented.
Invasive aspergillosis (IA) is a common and deadly mold infection in immunocompromised patients. As morbidity and mortality of IA are primarily driven by poor immune defense, adjunct immunotherapies, ...such as CAR T cells, are direly needed. Here, we propose a novel approach to generate Aspergillus fumigatus (AF)-CAR T cells using the scFv domain of AF-269-5 mAb and a lentiviral vector system.
Targeting domain of the AF-CAR construct was designed from the CDR sequence of AF-269-5 monoclonal antibody. The targeting domain was fused to the hinge and transmembrane domains of human CD8α and the cytoplasmic signaling domains of CD137/4-1BB and CD3ζ and subcloned in LV vector dCAS9-VP64-GFP (Addgene, Water Town, USA).
These cells successfully targeted mature hyphal filaments of representative clinical and reference AF isolates and elicited potent release of cytotoxic effectors and type 1 T-cell cytokines. Furthermore, AF-CAR T cells generated from peripheral blood mononuclear cells of four healthy human donors and expanded with cytokine stimulation (IL-2, IL-7+IL-15) regimens significantly suppressed mycelial growth of AF-293 after 18 h of co-culture and synergized with the immunomodulatory antifungal agent caspofungin to control hyphal growth for 36 hours. Moreover, cyclophosphamide-immunosuppressed NSG mice with invasive pulmonary aspergillosis that received two doses of 5 million AF-CAR T cells on days 0 and 2 after AF infection showed significantly reduced morbidity on day 4 post-infection (p<0.001) and significantly improved 7-day survival (p=0.049) compared to mice receiving non-targeting control T cells. This newly developed construct has several major advantages in its design and mode of action compared to published AF-reactive CAR T-cell products: (i) Unlike Dectin-1 CAR T cells that have weak affinity to mature mycelium, our present product was designed to efficiently target mature AF hyphae. (ii) Our AF-CAR T cells could enable generation of clinical-grade AF-CAR T cells for large scale production in a time frame of 3-7 days.
In conclusion, we developed a novel lentiviral strategy to obtain AF-CAR T cells with high targeting efficacy, yielding significant anti-AF activity in vitro and short-term protection in vivo. These results underscore the promise of anti-Aspergillus immunotherapy and provide a novel approach for efficient production of AF-CAR T cells for future clinical translation after further in-depth evaluation.
Standardization is helpful to consolidate application-oriented aspects of research and it achieves an intensive and interdisciplinary scientific exchange within plasma medicine worldwide. In the near ...future, it is absolutely necessary to develop international standards to enhance the acceptance and reputation of plasma medicine for physicians, patients and health insurance. As a result, it is possible to construct medical plasma devices on the global market which are effective, safe and conforming to standards.
PDF
