The principle of integral metal–organic framework (MOF) reconstruction is demonstrated for differently degraded HKUST‐1 via a facile, one‐step, solvent‐assisted treatment. Controlled MOF degradation ...by exposure to 77% humidity, liquid water, and diluted hydrochloric acid produces a mixture of non‐porous crystalline hybrid materials containing protonated linker and copper‐oxo species, which are then reconstructed back into high‐quality HKUST‐1 by contacting them with ethanol. X‐ray diffraction and sorption kinetics reveal a true memory effect of the system from completely degraded materials. The reconstruction approach is consequently extrapolated to gas‐ and liquid‐phase treatments in a fixed‐bed reactor with ethanol and ethanol/water mixtures for use in CO2 capture from a simulated pre‐combustion gas stream. Up to a maximum of 94% porosity and 85% CO2 sorption capacity can be recovered from a steamed material. A degradation‐reconstruction model is put forward based on X‐ray diffraction observations and structural analyses, microscopy, N2 sorption, thermogravitry–mass spectrometry and IR spectroscopy observations, particularly elucidating the influence of various degradation pathways on the reconstruction.
Reconstruction of water‐degraded HKUST‐1 back into the original material is demonstrated through solvent‐assisted liquid‐ and gas‐phase treatments. Up to 94% porosity and 85% CO2 sorption capacity could be recovered from a completely collapsed metal–organic framework. The degradation routes affect the physicochemical features and the kinetics of reconstruction. This method opens promising directions for the large‐scale application of these materials.
The principle of integral metal-organic framework (MOF) reconstruction is demonstrated for differently degraded HKUST-1 via a facile, one-step, solvent-assisted treatment. Controlled MOF degradation ...by exposure to 77% humidity, liquid water, and diluted hydrochloric acid produces a mixture of non-porous crystalline hybrid materials containing protonated linker and copper-oxo species, which are then reconstructed back into high-quality HKUST-1 by contacting them with ethanol. X-ray diffraction and sorption kinetics reveal a true memory effect of the system from completely degraded materials. The reconstruction approach is consequently extrapolated to gas- and liquid-phase treatments in a fixed-bed reactor with ethanol and ethanol/water mixtures for use in CO sub(2) capture from a simulated pre-combustion gas stream. Up to a maximum of 94% porosity and 85% CO sub(2) sorption capacity can be recovered from a steamed material. A degradation-reconstruction model is put forward based on X-ray diffraction observations and structural analyses, microscopy, N sub(2) sorption, thermogravitry-mass spectrometry and IR spectroscopy observations, particularly elucidating the influence of various degradation pathways on the reconstruction. Reconstruction of water-degraded HKUST-1 back into the original material is demonstrated through solvent-assisted liquid- and gas-phase treatments. Up to 94% poro-sity and 85% CO sub(2) sorption capacity could be recovered from a completely collapsed metal-organic framework. The degradation routes affect the physicochemical features and the kinetics of reconstruction. This method opens promising directions for the large-scale application of these materials.
GSM baseband-radios system-on-chip (SoC) fabricated in CMOS technology are well established on the market. The next evolutionary step on the proceeding integration path is the extension of the ...baseband-radio functionality by further integration of power-management-unit (PMU) functionality. This PMU of a mobile phone is normally realized as a separate chip. The integration of the PMU promises lowest phone cost, eases PCB design, reduces phone development time, and enables overall system optimization. However, several integration challenges have to be tackled. An SoC is presented for which the aforementioned challenges were successfully managed. The achieved performance will be demonstrated with corresponding measurement results.
Radar sensors are increasingly utilized in a wide range of automotive, industrial, consumer, and other applications. The most usual tasks are to measure distances or to detect the presence of ...objects, and this requires often to distinguish between 'wanted' and 'disturbing' radar targets. In this contribution, a concept for multi-spectral analysis of radar echoes over range is presented. Scattering and reflection properties of radar targets are assessed by analyzing the variance of the signal energy obtained from different spectral sub-bands. An amplitude-invariant signal-to-noise ratio (SNR) parameter is suggested to be used as a quantitative feature. Prior to the analysis, an inverse filtering is performed in order to eliminate the transfer characteristic of the utilized radar system. The proposed concept has been evaluated by means of measurements with a broadband 68 to 92 GHz frequency-modulated continuous-wave (FMCW) radar system. It will be shown that the proposed method allows for a good differentiation between single, point-like radar targets and spatially distributed radar targets, and for an according classification of objects.
A highly active Cu‐based Deacon catalyst with an enhanced lifetime was developed by combining two corrosion‐resistant high‐throughput reactor setups in this combinatorial study. Catalyst activities ...were studied in a sequential 10‐fold reactor equipped with online MS. For accelerated catalyst ageing studies, a parallel 10‐fold reactor was used. The starting point was a CuTi mixed‐metal oxide found in former discovery investigations. As development criteria, catalyst stability and HCl conversion were selected. The amount of Cu in the CuTi catalysts were analyzed before and after the ageing process by X‐ray fluorescence spectroscopy. Dopant elements were selected that are reported to form oxides with a high corrosion resistance against gaseous HCl. Our study revealed that doping with 1 mol % Nb reduced the Cu leaching during the reaction. Furthermore, the activation energy was decreased by Nb, which enhanced the chlorine production.
A beacon for Deacon: A highly active copper‐based Deacon catalyst with an enhanced lifetime is developed by combining two corrosion‐resistant high‐throughput reactor setups in this combinatorial study. MFC=mass flow controller.
Two ten‐channel fixed‐bed reactor systems were developed for high‐throughput screening of new Deacon catalysts. The sequential ten‐channel reactor allows the determination of the activity of up to ...ten catalysts per day. With a ten‐channel ageing reactor the long‐time stability of catalytic activity can be tested in parallel. Both systems are robust, quite resistant against corrosion, and use the identical reaction tubes which enable the direct transfer of a catalyst from one to the other system. A mass‐spectrometric pulse method has been developed and applied successfully for the analysis of the corrosive product gas mixture of the Deacon reaction.
The application of high‐throughput methods and reactors for the Deacon reaction poses a special challenge for researchers because of the corrosive reaction gas mixture. The development of two new multi‐reactor systems for reaction screening and catalyst ageing of highly corrosive reactions is described. Potential error sources and problems are discussed.
A digital receiver architecture for short-range communications systems like Bluetooth is presented. The architecture is tailored to a highly integrated Bluetooth single-chip integrated circuit (IC) ...and can easily be adapted to other communications systems using a Gaussian frequency-shift keying (GFSK ) modulation scheme. The single-chip IC integrates the complete digital baseband and radio frequency (RF) functionality on a single die and is realized in a 0.25-mum complementary metal-oxide-semiconductor (CMOS) technology targeted for cost efficiency. The superior performance of this digital receiver architecture compared to the state-of-the-art short-range communications receivers is shown. Simulation and measurement results are presented showing a receiver sensitivity of 87 dBm and excellent co-channel and adjacent channel interference performance.
In the diverse field of process industry, a plethora of technical processes are leveraged. Among these, liquids are often involved, being stored, transported and processed in tanks and reactors. ...Tailored to such applications, this contribution seeks to introduce and evaluate a novel technique for condition monitoring (CM). Within this technique, radar systems are employed and their functionality is augmented, enabling not only precise and accurate level measurements of liquids, but also distinction between different process conditions (PCs). For this purpose, distinguishing quantitative features are extracted from range-Doppler radar measurements. Thereafter, a classification is performed applying methods from machine learning. The potential of our proposed technique has been experimentally evaluated with respect to commonly encountered PCs. A frequency-modulated continuous wave (FMCW) Doppler radar system, operating in the V-/W-band, has been utilized for the measurements. It is demonstrated that the selected PCs can be distinguished with almost 98% accuracy, by extreme gradient boosting (XGB) along with quantitative features such as the peak-to-averaae power ratio.
GSM baseband-radios system-on-chip (SoC) fabricated in CMOS technology are well established on the market. The next evolutionary step on the proceeding integration path is the extension of the ...baseband-radio functionality by further integration of power-management-unit (PMU) functionality. This PMU of a mobile phone is normally realized as a separate chip. The integration of the PMU promises lowest phone cost, eases PCB design, reduces phone development time, and enables overall system optimization. However, several integration challenges have to be tackled. An SoC is presented for which the aforementioned challenges were successfully managed. The achieved performance will be demonstrated with corresponding measurement results.
In this contribution, the performance of different algorithms for range Doppler processing are compared and discussed for application in tank level probing radar. Algorithms using the fast Fourier ...transform and the keystone transform have been evaluated by simulations and measurements regarding the accuracy and the reliability of measuring the filling level of a liquid inside a tank. In addition the impact of waves on the surface of the liquid has been investigated. It is shown, that the keystone transform is capable to improve the performance of measurements in tank level scenarios.
