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On evidence-Based Practice in Disaster Risk Reduction

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International Journal of Disaster Risk Science 2021年第6期12卷 919-927页

作者： David e.alexander Institute for Risk and Disaster Reduction University College LondonLondon WCIE 6BTUK

Disaster science and scholarship are forever expanding and there are increasing calls to base disaster risk reduction policies on the evidence produced by such *** examples and argument,this opinion piece examines the nature of *** defines evidence-based practice and considers how it has developed and become important to disaster risk reduction.A definition of what constitutes evidence is difficult to achieve but it must be made in relation to whether the data and information collected can usefully be interpreted and employed to change things for the *** histories from past and present centuries show that evidence can sometimes be argued over *** other cases it is roundly *** yet other instances,false conclusions derived from evidence can become evidence in their own ***,there are situations in disaster risk reduction in which evidence is sorely needed but is clearly *** effectiveness of counter-terrorism measures is one such *** conclusion,evidence is valuable,above all if there is willingness to use it to support policy formulation,especially in a simple,transparent *** interpretation can never be entirely removed from the use of evidence,and evidence alone will not stimulate the policy formulators to improve their decision making.

关键词： Case histories Disaster risk reduction evidence-based practice Policy formulation

On the Meaning of Impact in Disaster Risk Reduction

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International Journal of Disaster Risk Science 2022年第5期13卷 822-827页

作者： David e.alexander Institute for Risk and Disaster Reduction University College LondonLondon WC1E 6BTUK

This article offers a discussion of the meaning,assessment,and measurement of impact in disaster risk *** begins with a historical perspective on the impact of learned work in times when orthodoxy posed severe limits on the impact of new *** the modern age,the article explains why impact is considered important and how it might be recognized when it occurs,including a tentative classification of types of *** question of whether impact can truly be measured remains pending,as the answer is diffuse and dependent on many different *** sections consider the relationship between impact and mainstreaming and the question of whether a piece of work should be regarded as having impact if its effects are negative rather than ***,impact is considered in terms of whom it *** the large number of possible reservations about the concept,the question is raised as to whether too much emphasis is given to the impact of research and ***,some suggestions are offered regarding how to obtain a better indication of what the impact of an academic study actually is.

关键词： Assessing impact Disaster risk reduction Disruptive thinking Impact of research Mainstreaming disaster risk reduction Measuring impact

Cloud-Based Optimal Control of Individual Borehole Heat exchangers in a Geothermal Field

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Journal of Thermal Science 2022年第5期31卷 1253-1265页

作者： STOFFeL Phillip kÜMPeL alexander MÜLLeR Dirk RWTH Aachen University E.ON Energy Research CenterInstitute for Energy Efficient Buildings and Indoor Climate52074 AachenGermany

Integrating renewable energy sources is a crucial component in reducing CO_(2) emissions in the building sector. In particular, shallow geothermal energy is expected to play a significant role in the regenerative energy supply of buildings. An effective control strategy for the geothermal field is crucial to reduce the overall energy consumption. This paper analyzes the benefits of controlling an existing field’s individual borehole heat exchangers(BHe) using nonlinear model predictive control(NMPC) and moving horizon estimation. The considered geothermal field consists of 41 BHes and is used for heating and cooling. each BHe is equipped with temperature sensors for in-and outflow and has individually controllable valves, while a central hydraulic pump feeds all BHes. The sensor measurements are accessed through a cloud platform, enabling also set point writing for the pump speed and the valve positions. To control the BHes individually, we propose a two-stage process. In the calibration stage, a moving horizon estimator estimates the actual borehole and ground temperatures for each BHe. In the second stage, first, a nonlinear model predictive controller optimizes the number of active BHes necessary to meet the buildings’ energy demand. With the estimated ground temperatures as a basis, it is determined which BHes shall be(de)-activated. The active BHes are fed with a fixed volume flow of 24 L/min to ensure turbulent heat transfer. To reduce the power usage of the pumps, an optimal control problem based on a simple hydraulic model of the geothermal field is used. The methodology is analyzed through simulations first and then validated experimentally. The results show that half or more of the BHes could be deactivated most of the time, leading to 67% savings in electricity consumption by the hydraulic pump. The experimental validation confirms the high energy saving potential of the proposed methodology, reducing the consumption of electrical energy by 71%. Additiona

关键词： geothermal energy moving horizon estimation model predictive control operation optimization optimal control

Improved thromboresistance and analytical performance of intravascular amperometric glucose sensors using optimized nitric oxide release coatings

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Chinese Chemical Letters 2015年第4期26卷 464-468页

作者： alexander k.Wolf Yu Qin Terry C.Major Mark e.Meyerhoff Department of Chemistry University of Michigan Department of Chemistry Nanjing University Department of Surgery University of Michigan

In this work, nitric oxide （NO） release coatings designed for intravenous amperometric glucose sensors are optimized through the use ofa polylactic acid （PLA） layer doped with a lipophilic diazeniumdiolated species that releases NO through a proton-driven mechanism. An elast-eon e2As polyurethane coating is used to both moderate NO release from the sensor surface and increase the sensor＇s linear detection range toward glucose. These sensors were evaluated for thromboresistance and in vivo glucose performance through implantation in rabbit veins. By maintaining NO flux on a similar scale to endogenous endothelial cells, implanted glucose sensors exhibited reduced surface clot formation which enables more accurate quantitative glucose measurements continuously. An in vivo time trace of implanted venous sensors demonstrated glucose values that correlated well with the discrete measurements of blood samples on a benchtop point-of-care sensor-based instrument. The raw measured currents from the implanted glucose sensors over 7 h time periods were converted to glucose concentration through use of both a one-point in vivo calibration and a calibration curve obtained in vitro within a bovine serum solution. Control sensors, assembled without NO release functionality, exhibit distinctive surface clotting over the 7 h in vivo implantation period.

关键词： Nitric oxide release coatingsGlucose sensorsPolylactic acid layerQuantitative glucose measurements

Transient thermal analysis as measurement method for IC package structural integrity

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Chinese Physics B 2015年第6期24卷 47-64页

作者： alexander Han Maximilian Schmid e Liu Gordon elger Technische Hochschule Ingolstadt

Practices of IC package reliability testing are reviewed briefly, and the application of transient thermal analysis is examined in great depth. For the design of light sources based on light emitting diode （LeD） efficient and accurate reliability testing is required to realize the potential lifetimes of 105 h. Transient thermal analysis is a standard method to determine the transient thermal impedance of semiconductor devices, e.g. power electronics and LeDs. The temperature of the semiconductor junctions is assessed by time-resolved measurement of their forward voltage （Vf）. The thermal path in the IC package is resolved by the transient technique in the time domain. This enables analyzing the structural integrity of the semiconductor package. However, to evaluate thermal resistance, one must also measure the dissipated energy of the device （i.e., the thermal load） and the.k.factor. This is time consuming, and measurement errors reduce the accuracy. To overcome these limitations, an innovative approach, the relative thermal resistance method, was developed to reduce the measurement effort, increase accuracy and enable automatic data evaluation. This new way of evaluating data simplifies the thermal transient analysis by eliminating measurement of the.k.factor and thermal load, i.e. measurement of the lumen flux for LeDs, by normalizing the transient Vf data. This is especially advantageous for reliability testing where changes in the thermal path, like cracks and delaminations, can be determined without measuring the.k.factor and thermal load. Different failure modes can be separated in the time domain. The sensitivity of the method is demonstrated by its application to high- power white InGaN LeDs. For detailed analysis and identification of the failure mode of the LeD packages, the transient signals are simulated by time-resolved finite element （Fe） simulations. Using the new approach, the transient thermal analysis is enhanced to a powerful tool for reliability

关键词： transient thermal analysis thermal resistance reliability light emitting diode

Development of a Long-Term Operational Optimization Model for a Building energy System Supplied by a Geothermal Field

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Journal of Thermal Science 2022年第5期31卷 1293-1301页

作者： kÜMPeL alexander STOFFeL Phillip MÜLLeR Dirk RWTH Aachen University E.ON Energy Research CenterInstitute for Energy Efficient Buildings and Indoor ClimateAachen 52074Germany

In order to reduce energy consumption and CO_(2) emissions in the building sector, more and more renewable energy sources are integrated into energy systems. especially geothermal fields combined with heat pumps are able to supply buildings with heat and cold at low carbon emissions. However, using geothermal fields as heat and cold source influences the ground temperature. Consequently, the ground temperature can change dramatically over a building’s lifetime, leading to less efficient operation of the energy system. Therefore, a sustainable operation is required to ensure the long-term efficiency of geothermal fields. In this paper, we develop an optimization model to derive operating strategies for an efficient long-term operation of a building energy system coupled to a geothermal field. The investigated energy system is the main building of the *** energy Research Center in Aachen, Germany, which includes a heat pump, two boilers, a combined heat, and power unit, a glycol cooler, and a geothermal field with 41 probes. For each component, we develop energy-based sub-models, which are connected to form the overall system. The geothermal field is modeled by using a g-functions approach as well as a simplified resistance-capacitance approach. To achieve short computing times and realize an optimization horizon of several years, the optimization problem is formulated as mixed-integer linear programming(MILP). The developed model is optimized regarding two different objectives: the minimization of energy costs and the minimization of long-term temperature changes in the ground. Conclusions for an efficient and sustainable operation of the field, especially for the cooling supply, can be derived from the optimization results. It is shown that a state of equilibrium should be aimed to achieve an energy-efficient operation, in which the temperature of the field is close to the initial ground temperature.

关键词： geothermal energy building energy systems operational optimization long-term operation

Magnetic Moment Tensor Potentials for collinear spin-polarized materials reproduce different magnetic states of bcc Fe

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npj Computational Materials 2022年第1期8卷 107-112页

作者： Ivan Novikov Blazej Grabowski Fritz körmann alexander Shapeev Skolkovo Institute of Science and Technology Skolkovo Innovation CenterNobel St.3Moscow143026Russia Institute for Materials Science University of StuttgartPfaffenwaldring 5570569StuttgartGermany Computational Materials Design Max-Planck-Institut für Eisenforschung GmbHD-40237DüsseldorfGermany Materials Science and engineering Delft University of Technology2628 CDDelftThe Netherlands

We present the magnetic Moment Tensor Potentials(mMTPs),a class of machine-learning interatomic potentials,accurately reproducing both vibrational and magnetic degrees of freedom as provided,e.g.,from first-principles *** accuracy is achieved by a two-step minimization scheme that coarse-grains the atomic and the spin *** performance of the mMTPs is demonstrated for the prototype magnetic system bcc iron,with applications to phonon calculations for different magnetic states,and molecular-dynamics simulations with fluctuating magnetic moments.

关键词： magnetic fluctuating states

A new method for precise optical measurements of the sub-micron height of levitation of droplet clusters

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Particuology 2024年第4期87卷 173-178页

作者： alexander A.Fedorets eduard e.k.lmakov Leonid A.Dombrovsky University of Tyumen 6 Volodarskogo StTyumen625003Russia engineering Faculty Ariel UniversityP0.B.3407000ArielIsrael Joint Institute for High Temperatures 17A Krasnokazarmennaya StMoscow111116Russia

Droplet clusters levitating over the locally heated water surface are considered a very promising phe-nomenon of microfluidics for the potential use of the droplets as unique microreactors for microbio-logical experiments.A new optical method is suggested for precise measurements of the sub-micron levitation height of single *** method is based on the analysis of variable colors of the inter-ference halo around the *** the first time,it is possible to measure the extremely low downward velocity of droplets,which grow due to steam *** velocity was found to be 5-8 nm/*** height of the levitation of various droplets just before their coalescence with a layer of water was also *** measurements might be used for the verification of sophisticated models for the droplet levitation to be developed for a very thin layer of humid air under the droplet when the.k.udsen effect should be taken into account.

关键词： Precise measurements Interferometric method Droplet cluster Levitation height

On a Measure of Non-compactness for Some Classical Operators

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Acta Mathematica Sinica,english Series 2006年第6期22卷 1847-1862页

作者： David e.eDMUNDS Alberto FIOReNZA alexander Me.k.I School of Mathematics Cardiff University Dipartimentodi Costruzioni e Metodi Matematici in Architettura Scuola Normale Superiore

The measure of non-compactness is estimated from below for various operators, including the Hardy-Littlewood maximal operator, the fractional maximal operator and the Hilbert transform, all acting between weighted Lebesgue spaces. The identity operator acting between weighted Lebesgue spaces and also between the counterparts of these spaces with variable exponents is similarly analysed. These results enable the lack of compactness of such operators to be quantified.

关键词： measure of non-compactness maximal functions singular integrals embeddings weight