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131.
This report examines the dilemma that a patient, who was a doctor, faced on discovering that he was developing a second primary testicular tumour (seminoma) in a solitary testis. The usual treatment for this is radical orchidectomy. He rejected this on the grounds that he wanted to have children, and eventually decided on the use of single-agent carboplatin chemotherapy. Seventeen months after treatment, there was no evidence of tumour on MRI or ultrasound scanning and there is some recovery of spermatogenesis. So far, 13 of 14 patients treated with chemotherapy for metastatic disease (with the primary tumour being left in situ), which has normalized following treatment, have survived for more than 5 years without evidence of tumour recurrence. This approach could be a viable option for men with tumours in a solitary testis who have not completed their families. However, a larger prospective study is essential to determine whether this approach is safe, so that these patients will not have to bear the psychological burden of choosing between their chances of survival and the possibility of fathering children. 相似文献
132.
Andrea Burdzik Markus Stähler Irene Friedrich Marcelo Carmo Detlef Stolten 《Journal of Coatings Technology and Research》2018,15(6):1423-1432
Electrodes for polymer electrolyte membrane electrolyzers and fuel cells are manufactured by coating a catalyst dispersion, consisting of precious metal, ionomer and solvents, onto a substrate that is subsequently dried. One target of current research is to produce square meter-sized electrodes, but so far the homogeneity that can be achieved in this scaling is unclear. To quantify the achievable homogeneity of an electrode, manufactured by means of slot die coating in a roll-to-roll pilot plant, this study focuses first on the selection of an appropriate substrate by investigating thickness, basis weight and surface free energy distribution at the square meter scale. Afterward, a dispersion is coated on the selected substrate, dried and investigated with respect to thickness and basis weight distribution. Among the investigated substrates, Kapton has the smallest scatter in terms of thickness and basis weight. The subsequent coating results in a precious metal loading of 1.10 mg cm\(^{-2}\), with a scattering of 5.5% that can be further reduced to 4.5% when edge effects can be prevented. These results are now available for further research in which it is necessary to investigate whether or not these fluctuations affect the achievable electrochemical efficiencies of electrodes. 相似文献
133.
Methods and principles of Lean Production have become the major concepts to create highly efficient processes since the early 1990s. Due to its high effectiveness by reducing complexity and focusing on value-adding tasks, the Lean concept is still successful. Nevertheless, its changeability to produce highly customised products is limited. Industry 4.0 describes the vision of a smart production which can meet these future market requirements. Enablers are innovative information and communication technologies and the integration of all production entities into a common digital network. Lean Automation is the application of Industry 4.0 technologies to Lean Production methods in order to combine benefits from both domains. First proprietary Lean Automation solutions exist, but to enhance changeability in production, a common, unified communication interface is required. This paper presents the ongoing work towards an interface for digitising Lean Production methods using Cyber Physical Systems. 相似文献
134.
Markus Stiller Pablo D. Esquinazi José Barzola Quiquia Christian E. Precker 《Journal of Low Temperature Physics》2018,191(1-2):105-121
Temperature- and field-dependent measurements of the electrical resistance of different natural graphite samples suggest the existence of superconductivity at room temperature in some regions of the samples. To verify whether dissipationless electrical currents are responsible for the trapped magnetic flux inferred from electrical resistance measurements, we localized them using magnetic force microscopy on a natural graphite sample in remanent state after applying a magnetic field. The obtained evidence indicates that at room temperature a permanent current flows at the border of the trapped flux region. The current path vanishes at the same transition temperature \(T_c\approx 370\) K as the one obtained from electrical resistance measurements on the same sample. This sudden decrease in the phase is different from what is expected for a ferromagnetic material. Time-dependent measurements of the signal show the typical behavior of flux creep of a permanent current flowing in a superconductor. The overall results support the existence of room-temperature superconductivity at certain regions in the graphite structure and indicate that magnetic force microscopy is suitable to localize them. Magnetic coupling is excluded as origin of the observed phase signal. 相似文献
135.
RILEM Recommendations57-TSB RILEM/CIB Joint Technical Committee
Testing of timber structures and building boards 相似文献136.
Thermal Conductivity and Thermal Expansion Coefficients of the Lanthanum Rare-Earth-Element Zirconate System 总被引:4,自引:0,他引:4
Henry Lehmann Dieter Pitzer Gerhard Pracht Robert Vassen Detlef Stöver 《Journal of the American Ceramic Society》2003,86(8):1338-1344
To enhance the insulating properties of a thermal barrier coating, one has to focus on new materials with lower intrinsic thermal conductivity than established yttria-stabilized zirconia. Substances with pyrochlore structure were investigated. Starting from lanthanum zirconate, substitutions of the lanthanum by other trivalent rare-earth elements were made, and the thermal conductivity and the thermal expansion coefficient of the manufactured materials were measured. A complete substitution of the lanthanum led to increased thermal expansion coefficients, whereas the partial substitution did not show an appreciable effect. The thermal conductivities of the modified materials were lower than that of the pure lanthanum zirconate for temperatures <1000°C for all amounts and elements of substitution. A comparison of the observed values with calculated values of the thermal conductivities showed a relatively good agreement. 相似文献
137.
138.
139.
Quantitative atom probe analysis of carbides 总被引:1,自引:0,他引:1
Thuvander M Weidow J Angseryd J Falk LK Liu F Sonestedt M Stiller K Andrén HO 《Ultramicroscopy》2011,111(6):604-608
Compared to atom probe analysis of metallic materials, the analysis of carbide phases results in an enhanced formation of molecular ions and multiple events. In addition, many multiple events appear to consist of two or more ions originating from adjacent sites in the material. Due to limitations of the ion detectors measurements generally underestimate the carbon concentration. Analyses using laser-pulsed atom probe tomography have been performed on SiC, WC, Ti(C,N) and Ti2AlC grains in different materials as well as on large M23C6 precipitates in steel. Using standard evaluation methods, the obtained carbon concentration was 6-24% lower than expected from the known stoichiometry. The results improved remarkably by using only the 13C isotope, and calculating the concentration of 12C from the natural isotope abundance. This confirms that the main reason for obtaining a too low carbon concentration is the dead time of the detector, mainly affecting carbon since it is more frequently evaporated as multiple ions. In the case of Ti(C,N) and Ti2AlC an additional difficulty arises from the overlap between C2+, C42+ and Ti2+ at the mass-to-charge 24 Da. 相似文献
140.
Solubility Studies of Sodium Azide in Liquid Ammonia by In Situ Ultrasonic Velocity Measurement
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Hasan Baser Wilhelm Schwieger Detlef Freitag Thomas G. Steigerwald Eberhard Schluecker 《化学工程与技术》2017,40(6):1101-1106
Ultrasonic velocity measurement data has been established as a simple and convenient tool to determine different thermodynamic properties of liquids and solutions. Such measurements were carried out in situ to determine the solubility of NaN3 in liquid ammonia within a defined temperature range. Different mixtures of NaN3 in ammonia were prepared and the ultrasonic velocities of these mixtures were measured within this temperature range in order to compile calibration curves. Further, these calibration curves were used to calculate the solubility in a saturated solution. 相似文献