1,139 research outputs found
Immunodiagnosis of angiostrongyliasis with monoclonal antibodies recognizing a circulating antigen of mol.wt 91,000 from Angiostrongylus cantonensis
No full textStrained InAsN/InGaAs/InP multiple quantum well structures grown by RF-plasma assisted GSMBE for mid-infrared laser applications
No full textH.H. Beltman: Natuursteencollecties deel 7
No full textDeel 6 over natuursteencollecties ging over de collectie ir. J.H. Beltman bij het Mineralogisch-Geologisch Museum (MGM) van de TU Delft en hoe deze collectie met 222 marmers terug te voeren valt op de steenhouwerij en machinale fabriek van marmerwerken H.H. Beltman uit Deventer. In deel 7 gaat universitair docent Heritage & Technology en natuursteenspecialist Wido Quist van de TU Delft dieper in op dit bedrijf aan de hand van een in 1907 opgemaakte inventaris van het hele bedrijf en ook op het tweede deel van de inventaris van de collectie.Heritage & Technolog
Shubnikov–de Haas oscillations of two-dimensional electron gas in an InAsN/InGaAs single quantum well
No full textWe present the first investigation of Shubnikov–de Haas (SdH) oscillations
of two-dimensional electron gas formed in an InAsN/InGaAs single
quantum well (QW) grown on an InP substrate using gas source molecular
beam epitaxy and a radio-frequency (rf ) plasma nitrogen source. The
photoluminescence (PL) peak energy of the InAsN/InGaAs QW decreases
compared with that of InAs/InGaAs QW. This agrees with the bowing effect
due to the incorporation of nitrogen atoms. The nitrogen content can be
estimated to be 0.4% using the PL peak positions as well as x-ray
diffraction. From the SdH oscillations, the carrier concentration is 2.85 × 1011 cm−2 and the effective mass is 0.1±0.01m0. The enhancement of the
effective mass is mainly due to the incorporation of the nitrogen atoms in the
InAs lattice, which is consistent with a recent study on InAsN bulk alloys.
The large increase of the effective mass cannot be explained by the simple
band anticrossing model. In addition, we observe a temperatureindependent
magnetoresistivity at a critical magnetic field. Our analysis
supports the fact that the value of the critical exponent in the quantum Hall
effect is not universal
Letter from [John Victor Carson], Dominguez Estate Company to MR. John L. Wyatt, June 20, 1938
No full textReferring Mr. Wyatt to Mr. H.H. Jarrett concerning land sales
H. H. Hall
No full textPhotograph - H.H. Hall, school teacher, playing tennis with Revillon Brothers building in the background, Athabasca, Albert
Machine Learning Models Forecasting Optoelectronic Service Lifetimes of Low-Bandgap Perovskite Solar Cells
No full textThesis (Master's)--University of Washington, 2024Accurately predicting the lifetime of perovskite solar cells (PSCs) is essential for their successful commercialization. Mixed Sn-Pb halide perovskites are promising materials because of their relatively low bandgap (~1.2-1.3 eV) making them a strong candidate for use as the absorber layer in single-junction solar cells or as the low-bandgap subcell absorber in all perovskite tandem solar cells. However, this composition suffers from stability issues when exposed to environmental conditions. By collecting experimental data from accelerated degradation, we learn that efficiency losses are driven by short-circuit current and indicate that the loss in perovskite material is a major contributor to degradation. Additionally, we have identified significant correlations between device lifetime and the perovskite degradation rate (derived from previous studies), partial pressure of water, and early time derivative of specific device measurements. To predict the lifetime of PSCs, machine learning models were trained using a menu of features that were split into 3 distinct categories: (1) a priori known features, (2) initial device measurements, and (3) measurements of the initial rates of change of device parameters. With a dataset consisting of 39 degradation experiments, trained models reveal that the derived degradation rate of the FA0.75Cs0.25Pb0.5Sn0.5I3 perovskite material is a valuable feature for forecasting PSC lifetime and was selected as the most dominant feature in the best performing models which demonstrate a median test error of 26%. These findings underscore the importance of quantitative measurements of perovskite degradation in accurately forecasting the lifetime of PSCs and highlight the utility of integrating such metrics into predictive models
Electronic instabilities and structural fluctuations in self-assembled atom wires
No full textOne-dimensional (1D) solid state systems can behave drastically different from their higher dimensional counterparts. Increased interactions can produce electronic and/or structural instabilities. In this respect, the following fundamental questions are important for a proper understanding of the properties of the ultimate 1D systems consisting of atom wires: Are atom wires created by self-assembly on silicon (Si) surfaces actually stable? Do atom wires exist that are metallic (at low temperatures)? What role is played by defects in these atom wires? This Thesis attempts to find an answer to these questions. Atom wires were realized by self-assembly on vicinal Si surfaces. Using Scanning Tunneling Microscopy and Spectroscopy combined with Density Functional Theory calculations, a full analysis of the (thermodynamic) stability of Gallium (Ga) atom wires on Si(112) has been made, including the energetics of fluctuating intrinsic structural defects. It is shown that the stable atom wires fully passivate the surface, and that the spacing between intrinsic quasi-1D meandering vacancy lines can be tuned continuously through experimental adjustment of the Ga chemical potential. Gold atom wires on the Si(553) surface show an incommensurate metallic state at room temperature. Decreasing the temperature, two competing charge density waves (CDW) within single atom wires are observed, accompanied by a third CDW coexisting in between those wires. Defects in the atom wires induce interband charge transfer, resulting in commensurate CDWs at low temperatures. Finally, manipulatable phase slips with fractional charge and spin are observed for the first time in a CDW in real space.Applied Science
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