Development of a building energy model and a mean radiant temperature scheme for mesoscale climate models, and applications in Berlin (Germany)

In dieser Arbeit wird die Entwicklung eines Gebäudeenergiemodells (BEM) und eines Schemas für die mittlere Strahlungstemperatur ($T_mrt$) vorgestellt, das in das Doppel-Canyon basierte städtische Bestandsschichtsschema (DCEP) integriert ist. Das erweiterte DCEP-BEM Modell zielt darauf ab, eine Verbindung zwischen anthropogener Wärme und dem Stadtklima herzustellen, indem Gebäude in Straßenschluchten einbezogen werden, um die Energieflüsse auf städtischen Oberflächen, die Auswirkungen der anthropogenen Wärme auf die Atmosphäre, die Innenraumlufttemperatur und die Abwärme von Klimaanlagen zu untersuchen. Das DCEP-BEM wird mit dem mesoskaligen Klimamodell COSMO-CLM (COnsortium for Small-scale MOdelling in CLimate Mode, im Folgenden CCLM) gekoppelt und zur Simulation des Winters und Sommers 2018 in Berlin. Die Auswertung der Wintersimulationen zeigt, dass CCLM/DCEP-BEM den mittleren Tagesverlauf der gemessenen turbulenten Wärmeströme gut reproduziert und die simulierte 2-m-Lufttemperatur und den städtischen Wärmeinseleffekt (UHI) verbessert. Im Sommer bildet das CCLM/DCEP-BEM die Innenraumlufttemperatur richtig ab und verbessert die Ergebnisse für die 2-m-Lufttemperatur und die UHI leicht. Außerdem wird das CCLM/DCEP-BEM angewendet, um die Abwärmeemissionen von Klimaanlagen im Sommer zu untersuchen. Die Abwärmeemissionen der Klimaanlagen erhöhen die Lufttemperatur in Oberflächennähe erheblich. Der Anstieg ist in der Nacht und in hochurbanisierten Gebieten stärker ausgeprägt. Es werden zwei Standorte für die AC-Außengeräte betrachtet: entweder an der Wand eines Gebäudes (VerAC) oder auf dem Dach eines Gebäudes (HorAC). Die Auswirkung von HorAC ist im Vergleich zu VerAC insgesamt geringer, was darauf hindeutet, dass HorAC einen kleineren Einfluss auf die oberflächennahe Lufttemperatur und den UHI hat. Ein Schema für $T_mrt$ wird für das CCLM/DCEP-BEM entwickelt und umfassend validiert. Es wird gezeigt, dass dieses Schema eine zuverlässige Darstellung von $T_mrt$ bietet.This work presents the development of a building energy model (BEM) and a mean radiant temperature ($T_mrt$) scheme integrated in the urban canopy scheme Double Canyon Effect Parametrization (DCEP). The extended DCEP-BEM model aims to establish a link between anthropogenic heat emissions and urban climate by including the interior of buildings in urban street canyons to investigate the energy fluxes on urban surfaces, the effects of anthropogenic heat on the atmosphere, the evolution of indoor air temperature, and waste heat from air conditioning (AC) systems. DCEP-BEM is coupled with the mesoscale climate model COSMO-CLM (COnsortium for Small-scale MOdelling in CLimate Mode, hereafter CCLM) and applied to simulate the winter and summer 2018 of Berlin. The evaluation for winter simulations indicates that CCLM/DCEP-BEM reproduces well the average diurnal characteristics of the measured turbulent heat fluxes and considerably improves the simulated 2-m air temperature and urban heat island (UHI). In summer, CCLM/DCEP-BEM accurately reproduces the indoor air temperature, and slightly improves the performance of the 2-m air temperature and the UHI effect. Furthermore, CCLM/DCEP-BEM is applied to explore the waste heat emissions from AC systems in summer. AC waste heat emissions considerably increase the near-surface sensible heat flux and air temperature. The increase is more pronounced during the night and in highly urbanised areas. Two locations for the AC outdoor units are considered: either on the wall of a building (VerAC) or on the rooftop of a building (HorAC). The effect of HorAC is overall smaller compared to VerAC, indicating that HorAC has a smaller impact on the near-surface air temperature and the UHI effect. A $T_mrt$ scheme is developed for CCLM/DCEP-BEM and extensively evaluated. It is shown that this scheme provides a reliable representation of $T_mrt$

Estimation of mean radiant temperature in cities using an urban parameterization and building energy model within a mesoscale atmospheric model

During daylight hours, the mean radiant temperature Tmrt is one of the most important meteorological parameters to analyse heat stress for humans. This study conducts a spatio-temporal analysis of Tmrt for a summer period in 2018 for the city of Berlin, Germany. To this end, the mesoscale climate model COSMOCLM (CCLM) is coupled with the urban Double Canyon Effect Parameterization scheme with a building energy model (DCEP–BEM) to derive Tmrt. This coupled model system CCLM/DCEP–BEM enables a dynamic calculation of Tmrt for the microscale urban street canyons using a mesoscale model. To bring a more accurate comparison, a two-step approach is applied to assess the radiative fluxes and Tmrt from CCLM/DCEP–BEM. The radiation model SOLWEIG is first validated against measurement and then used to evaluate the DCEP–BEM model. Overall good agreement in Tmrt is found between CCLM/DCEP–BEM and SOLWEIG (R2 = 0.96). Nighttime Tmrt simulated with CCLM/DCEP–BEM is higher than that with SOLWEIG (MBE = 2.9K), yet closer to measurements. Tmrt during the afternoon hours modeled with CCLM/DCEP–BEM is underestimated compared to SOLWEIG (MBE = −3.1K). Further, excluding vegetation, higher values for nighttime Tmrt are found in the densely built-up city center than in the suburbs with more open structures, while the city center has lower values for Tmrt during midday. This study provides a reliable representation of Tmrt in a mesoscale model and would be beneficial for future implementation of human-biometeorological variables such as the Universal Thermal Climate Index or Physiological Equivalent Temperature. These quantities are calculated using Tmrt.Peer Reviewe

Do Electric Vehicles Mitigate Urban Heat? The Case of a Tropical City

On top of their well known positive impact on air quality and CO2 emissions, electric vehicles generate less exhaust heat compared to traditional vehicles thanks to their high engine efficiency. As such, electric vehicles have the potential to mitigate the excessive heat in urban areas—a problem which has been exacerbated due to urbanisation and climate change. Still, the heat mitigation potential of electric vehicles has not been fully understood. Here, we combine high-resolution traffic heat emission inventories with an urban climate model to simulate the impact of the fleet electrification to the near-surface air temperature in the tropical city of Singapore. We show that a full replacement of traditional internal combustion engine vehicles with electric vehicles reduces the near-surface air temperature by up to 0.6°C. The heat mitigation potential is highest during the morning traffic peak and over areas with the largest traffic density. Interestingly, the reduction in exhaust heat emissions due to the fleet electrification during the evening traffic peak hardly leads to a reduction of near-surface air-temperatures, which is attributed to the different atmospheric conditions during morning and evening. This study presents a new quantification of the city-wide impact of electric vehicles on the air temperature in a tropical urban area. The results may support policy-makers toward designing holistic solutions to address the challenge of climate change adaptation and mitigation in cities.Peer Reviewe

Syntheses, neural protective activities, and inhibition of glycogen synthase kinase-3beta of substituted quinolines.

A new series of fifteen 5-, 6-, and 8-appended 4-methylquinolines were synthesized and evaluated for their neural protective activities. Selected compounds were further examined for their inhibition of glycogen synthase kinase-3β (GSK-3β) and protein kinase C (PKC). Two most potent analogs, compounds 3 and 10, show nanomolar protective activities in amyloid β-induced MC65 cells and enzymatic inhibitory activities against GSK-3β, but poor PKC inhibitory activities. Using normal mouse model, the distribution of the most potent analog 3 in various tissues and possible toxic effects in the locomotors and inhibition of liver transaminases activities were carried out. No apparent decline of locomotor activity and no inhibition of liver transaminases were found. The compound appears to be safe for long-term use in Alzheimer’s disease mouse model

Characterization and source identification of fine particulate matter in urban Beijing during the 2015 Spring Festival

The Spring Festival (SF) is the most important holiday in China for family reunion and tourism. During the 2015 SF an intensive observation campaign of air quality was conducted to study the impact of the anthropogenic activities and the dynamic characteristics of the sources. During the study period, pollution episodes frequently occurred with 12 days exceeding the Chinese Ambient Air Quality Standards for 24-h average PM2.5 (75 μg/m3), even 8 days with exceeding 150 μg/m3. The daily maximum PM2.5 concentration reached 350 μg/m3 while the hourly minimum visibility was <0.8 km. Three pollution episodes were selected for detailed analysis including chemical characterization and diurnal variation of the PM2.5 and its chemical composition, and sources were identified using the Positive Matrix Factorization model. The first episode occurring before the SF was characterized by more formation of SO42− and NO3− and high crustal enrichment factors for Ag, As, Cd, Cu, Hg, Pb, Se and Zn and seven categories of pollution sources were identified, whereby vehicle emission contributed 38% to the PM2.5. The second episode occurring during the SF was affected heavily by large-scale firework emissions, which led to a significant increase in SO42−, Cl−, OC, K and Ba; these emissions were the largest contributor to the PM2.5 accounting for 36%. During the third episode occurring after the SF, SO42−, NO3−, NH4+ and OC were the major constituents of the PM2.5 and the secondary source was the dominant source with a contribution of 46%. The results provide a detailed understanding on the variation in occurrence, chemical composition and sources of the PM2.5 as well as of the gaseous pollutants affected by the change in anthropogenic activities in Beijing throughout the SF. They highlight the need for limiting the firework emissions during China's most important traditional festival

Identificació dels errors gramaticals en anglès dels nivells B2 i C1 del MCERL i les seves causes

[ES] Con la globalización de la economía, la política y la cultura, el inglés es cada vez más importante como herramienta para la comunicación en el ámbito internacional. La escritura en inglés puede considerarse un reflejo de la capacidad de comunicarse en un idioma, que consta de dos componentes principales: el vocabulario y la gramática. En este trabajo utilizamos el corpus para analizar los errores gramaticales en la escritura de los estudiantes y usamos la teoría del análisis de errores como base teórica principal. Para el estudio hemos recopilado un corpus de escritos de alumnos de inglés de los niveles B2 y C1 de una escuela de idiomas española. Para llevar a cabo el análisis utilizamos cinco pasos del análisis de errores, con el objetivo de responder a las siguientes preguntas: 1. ¿Cuáles son los errores gramaticales más comunes en la escritura en inglés de los alumnos de los niveles de lengua B2 y C1? 2. ¿Cuáles son las posibles causas de estos errores? 3. ¿cuáles son las recomendaciones para la escritura en los niveles B2 y C1? Recogimos un total de 163 redacciones de estudiantes de estos dos niveles, luego construimos nuestro propio corpus y utilizamos Sketch Engine para buscar en el corpus cada uno de los 11 tipos de errores para producir los resultados de la búsqueda. Además, analizamos los datos en relación con la bibliografía de los resultados de la búsqueda y proporcionamos un análisis de los ejemplos de los seis errores más frecuentes. Por último, analizamos las posibles razones de los errores a partir del análisis de los errores. La finalidad de este estudio es ayudar a los estudiantes de ambos niveles a encontrar los errores gramaticales más frecuentes, proponerles sugerencias de redacción y mejorar su escritura.[EN] With the globalization of economics, politics and culture, English is becoming increasingly important as a tool for communication in the international arena. English writing can be considered a reflection of overall language ability, which consists of two main components: vocabulary and grammar. We used the corpus to analyze grammatical errors in students' writing and used error analysis theory as the main theoretical basis. For the study we collected a corpus of writings of English learners at B2 and C1 levels from a Spanish language school. To carry out the study we used the five steps of error analysis, with the aim of answering the following questions: 1. what are the most common grammatical errors in the English writing of B2 and C1 level students? 2. what are the possible causes of these errors? 3. what are the recommendations to improve the grammatical accuracy of English writing? 3. what are the recommendations for writing at B2 and C1 levels? We collected a total of 163 student essays from these two levels, then constructed our own minicorpus and used Sketch Engine to search the corpus for each of the 11 error types in turn to produce the search results. In addition, we analyzed the data against the literature of the search results and provided an example analysis of the six errors with the highest error rates. Finally, we analyze the possible reasons for the errors based on the analysis of the errors in the typical examples. study is to help students at both levels to find the most frequent grammatical errors and to propose suggestions for writing and for improving their writing.Jin, L. (2022). Identificación de los errores gramaticales en inglés en los niveles B2 y C1 del MCERL y sus causas. Universitat Politècnica de València. http://hdl.handle.net/10251/18913

NDN-Based Coded Caching Strategy for Satellite Networks

To solve the transmission correlation issue arising from traditional named data networking (NDN) caching during segmenting contents, where users must obtain data blocks related to the requested file blocks to recover the source data, in this paper, we propose an NDN-based coded caching strategy for low Earth orbit (LEO) satellite networks, using coding operations to remove the transmission correlation of data. To achieve efficient content distribution, the satellite node’s coded package is strategically placed with the objectives of minimizing the backhaul link load and content acquisition latency. The optimization problem is solved by using a multi-colony ant colony algorithm, enabling fast content retrieval. We designed a cluster cooperative distribution mechanism to simplify the satellite network’s management and reduce the load of satellite links for content distribution when covered by multiple satellite nodes. Finally, we compare the multi-objective coded caching (CCMO) introduced in this paper with the most popular (MP) strategy and the random-based coded caching (CCR) strategy; the average cache hit ratio, backhaul link load, and content acquisition delay are compared and analyzed. The results show that CCMO performs better

Impact of Air Conditioning Systems on the Outdoor Thermal Environment during Summer in Berlin, Germany

This study investigates the effect of anthropogenic heat emissions from air conditioning systems (AC) on air temperature and AC energy consumption in Berlin, Germany. We conduct simulations applying the model system CCLM/DCEP-BEM, a coupled system of the mesoscale climate model COSMO-CLM (CCLM) and the urban Double Canyon Effect Parameterization scheme with a building energy model (DCEP-BEM), for a summer period of 2018. The DCEP-BEM model is designed to explicitly compute the anthropogenic heat emissions from urban buildings and the heat flux transfer between buildings and the atmosphere. We investigate two locations where the AC outdoor units are installed: either on the wall of a building (VerAC) or on the rooftop of a building (HorAC). AC waste heat emissions considerably increase the near-surface air temperature. Compared to a reference scenario without AC systems, the VerAC scenario with a target indoor temperature of 22 °C results in a temperature increase of up to 0.6 K . The increase is more pronounced during the night and for urban areas. The effect of HorAC on air temperature is overall smaller than in VerAC. With the target indoor temperature of 22 °C , an urban site’s daily average AC energy consumption per floor area of a room is 9.1 W m2 , which is 35% more than that of a suburban site. This energy-saving results from the urban heat island effect and different building parameters between both sits. The maximum AC energy consumption occurs in the afternoon. When the target indoor temperature rises, the AC energy consumption decreases at a rate of about 16% per 2 K change in indoor temperature. The nighttime near-surface temperature in VerAC scenarios shows a declining trend ( 0.06 K per 2 K change) with increasing target indoor temperature. This feature is not obvious in HorAC scenarios which further confirms that HorAC has a smaller impact on near-surface air temperature.Peer Reviewe

Integration of a Building Energy Model in an Urban Climate Model and its Application

We report the ability of an urban canopy model, coupled with a regional climate model, to simulate energy fluxes, the intra-urban variability of air temperature, urban-heat-island characteristics, indoor temperature variation, as well as anthropogenic heat emissions, in Berlin, Germany. A building energy model is implemented into the Double Canyon Effect Parametrization, which is coupled with the mesoscale climate model COSMO-CLM (COnsortium for Small-scale MOdelling in CLimate Mode) and takes into account heat generation within buildings and calculates the heat transfer between buildings and the urban atmosphere. The enhanced coupled urban model is applied in two simulations of 24-day duration for a winter and a summer period in 2018 in Berlin, using downscaled reanalysis data to a final grid spacing of 1 km. Model results are evaluated with observations of radiative and turbulent energy fluxes, 2-m air temperature, and indoor air temperature. The evaluation indicates that the improved model reproduces the diurnal characteristics of the observed turbulent heat fluxes, and considerably improves the simulated 2-m air temperature and urban heat island in winter, compared with the simulation without the building energy model. Our set-up also estimates the spatio–temporal variation of wintertime energy consumption due to heating with canyon geometry. The potential to save energy due to the urban heat island only becomes evident when comparing a suburban site with an urban site after applying the same grid-cell values for building and street widths. In summer, the model realistically reproduces the indoor air temperature and its temporal variation.Peer Reviewe