bluuebunny/crossref_metadata_2025_split huggingface dataset:
Question Answering Systems for Covid-19
Authors: Gupta Poonam , Garg Ruchi , Kaur Amandeep 
Published: December 2021

AbstractIn the present scenario COVID-19 pandemic has ruined the entire world. This situation motivates the researchers to resolve the query raised by the people around the world in an efficient manner. However, less number of resources available in order to gain the information and knowledge about COVID-19 arises a need to evaluate the existing Question Answering (QA) systems on COVID-19. In this paper, we compare the various QA systems available in order to answer the questions raised by the people like doctors, medical researchers etc. related to corona virus. QA systems process the queries submitted in natural language to find the best relevant answer among all the candidate answers for the COVID-19 related questions. These systems utilize the text mining and information retrieval on COVID-19 literature. This paper describes the survey of QA systems-CovidQA, CAiRE (Center for Artificial Intelligence Research)-COVID system, CO-search semantic search engine, COVIDASK, RECORD (Research Engine for COVID Open Research Dataset) available for COVID-19. All these QA systems are also compared in terms of their significant parameters-like Precision at rank 1 (P@1), Recall at rank 3(R@3), Mean Reciprocal Rank(MRR), F1-Score, Exact Match(EM), Mean Average Precision, Score metric etc.; on which efficiency of these systems relies.
Design and Simulation of Hybrid Solar PV-Fuel-Cell-Battery System to supply in the Nit Kurukshetra Campus and its effect on the Environment using Homer Software
Authors: kumar Alok , Vadhera Shelly 
Published: December 2021

Abstract
The main objective of this paper is to design a hybrid power system for continuous power supply in the institute campus nit Kurukshetra in an economical way to replace the external grid power system. In this paper solar photovoltaic Fuel cell battery hybrid system has been studied. Costing, sizing, optimization, and simulation were done using the software homer pro. The Levelized Cost of electricity (COE) is Rs. 11.12 per KW is obtained and the system is based on renewable energy sources so it sustainably generates electricity.
A simplified SVPWM method for cascaded multilevel inverters
Authors: Matale Nishant , Thakre Mohan , Shriwastava Rakesh 
Published: December 2021

Abstract
A highly popular alternative in medium voltage and high-power applications is multilevel converters because of their superior performance over conventional two-level converters. The most commonly used control methods in the case of multilevel inverters are sine pulse width modulation (SPWM) and space vector pulse width modulation (SVPWM) methods. Among these two control strategies, SVPWM has superior performance over SPWM in terms of DC bus voltage utilization along with a reduction in total harmonic distortion (THD) of line voltages. The classical SVPWM method has various drawbacks such as computational complexity for identifying the location of reference voltage vector, sector identification, region identification, memory requirement to store lookup tables for switching vectors. The novel simplified SVPWM technique is presented for cascaded H-Bridge multilevel inverter (CHBMLI) in this paper. This simplified SVPWM method has overcome the drawbacks of the classical SVPWM method. This new technique has been implemented into a five-level CHBMLI to evaluate performance and also to compare with the SPWM method. The simulation has been performed in MATLAB software.
Hygrothermal performance of hemp lime concrete embedded with phase change materials for buildings
Authors: Omeme Ada A.M. , Tran Le A. D. , Toifane H. , Tittelein P. , Zalewski L. , Antczak E. , Douzane O. , Langlet T. 
Published: December 2021

Abstract
The use of biobased materials in building construction allows the reduction of fossil resource use and energy consumption. Among biobased materials, hemp lime concrete has been investigated in many studies highlighting its capacity to regulate interior relative humidity and its high insulation capacity. In order to design high-performance biobased concretes, a new hemp lime concrete combining the hygric regulation capacity of hemp lime concrete with the thermal regulation performance of phase change material was developed. This article focuses on the thermal and hygric performance of the new hemp lime concretes incorporating micro-capsulated phase change material (PCM) (named HL-PCM). Three hemp lime concretes that differ from formulation were developed and investigated. The thermal properties, moisture buffer values and its impact on interior relative humidity variation have been presented. Thanks to experimental works and numerical simulations, the results obtained showed that the thermal conductivity remain low, the heat capacity and thermal inertia increase considerably for hemp concrete with PCM, while the moisture buffering capacity remains excellent. Finally, numerical results showed that the used of hemp lime concrete (with and without PCM) reduce indoor relative humidity variation and improve indoor hygrothermal comfort.
Identifying the critical orientation of wood-frame walls in assessing moisture risks using hygrothermal simulation
Authors: Aggarwal Chetan , Defo Maurice , Ge Hua , Lacasse Michael A 
Published: December 2021

Abstract
Hygrothermal simulations can be used as a reliable tool in analysing moisture performance. For an efficient analysis, it is important to appropriately select the wall orientation in the simulations. ASHRAE 160 recommends to using orientation with highest amount of annual wind-driven rain (WDR) and the orientation with the least annual solar radiation. The objective of this work was to identify the orientation which leads to the worst moisture performance of different wall assemblies under historical climate in different Canadian cities. Four cardinal orientations (North, East, South, and West) and orientation receiving the highest amount of annual WDR (Default) were tested in this study. The simulations were carried out assuming three scenarios of moisture loads for four different wood-frame (2×6 wood stud) wall systems that differ by their claddings: brick, fibreboard, stucco, and vinyl. With an assumption of no WDR, north facing wall always leads to the worst moisture performance. In the presence of WDR, with and without water source, default orientation leads to the worst moisture performance with few exceptions. As default orientation was based on total sum of WDR, it sometimes may not lead to worst performance and hence hourly distribution of WDR should be taken into consideration.
Development of moisture reference years for assessing long-term mould growth risk of wood-frame building envelopes
Authors: Wang Lin , Defo Maurice , Gaur Abhishek , Lacasse Michael A 
Published: December 2021

Abstract
A moisture reference year (MRY) is generally used to assess the durability, or long-term performance of building envelopes within a long climatological time period, e.g. a 31 year timeframe. The intent of this paper is to develop a set of moisture reference years that can be used to assess risk to the formation of mould growth in wood-frame buildings over the long-term. The set of moisture reference years have been developed based on 15 realizations of 31-year climate data. Replicated Latin Hypercube Sampling is applied to select 15 sub-realizations with 7 representative years having different levels of moisture index (MI) from each realization. Thereafter, hygrothermal simulations are performed for a brick veneer clad wood-frame wall assembly using the 15 sub-realizations; that sub-realization which produces the highest value of maximum mould growth index over 7-year period is selected as the MRY. The selection process is then implemented for all 15 realizations of the 31-years of data sets, from which 15 sets of 7-year long MRYs are selected to represent the original 15 realizations. It is shown that the 15 sets of 7-year long MRYs can produce the same value of maximum mould growth index as well as the uncertainty as compared to the original 15 realizations having a 31-year climate data set.
Hygrothermal performance of internally insulated masonry walls with embedded wooden beam heads: a field study on the impact of hydrophobisation
Authors: Vereecken E , Roels S 
Published: December 2021

Abstract
Internal insulation remains often the only option to thermally upgrade massive masonry. Unfortunately, internal insulation can significantly change the wall’s hygrothermal performance, resulting in a higher risk on frost damage, wood rot of embedded beam heads, etc. The application of hydrophobisation is often put forward as a potential measure to avoid moisture problems, though more research on the impact of hydrophobisation is still required. Thereto, the current paper presents the results of a field study on the hygrothermal performance of internally insulated masonry with embedded wooden beam heads, exposed to wind-driven rain. Both a vapour open capillary active and a vapour tight insulation system are studied. Mainly the moisture conditions near the back of the wooden beam head are found to be influenced by hydrophobisation, which lowers the relative humidity. Closer to the masonry’s interior surface, the choice of the insulation system also influences the results. In case of a well-applied hydrophobisation, overall, the vapour tight system shows a better performance than the capillary active vapour open system. An exception to this is found for the first months after applying the hydrophobisation and the insulation system, where a longer drying period is needed in case of the vapour tight system.
Investigation of phase change materials (PCMs) on the heat transfer performance of building systems
Authors: Zhou Hongxia , Fransson Åke , Olofsson Thomas 
Published: December 2021

Abstract
The energy use of building systems contributes to a large percentage of total energy consumption, which requires consideration. Solutions of improvement to save energy are crucial. Phase change materials have been proved to be good candidates to be used in building envelopes for energy save. In this paper, an extended Explicit Finite Element Method (ex-FEM), which has been previously introduced and improved, is taken for simulation of temperatures and heat transfer in simplified multilayer wall constructions, consisting of PCM and insulation. The method has been validated against experimental data measured in a so-called Hot-Box. Temperature data are measured at different positions in a number of simplified multilayer walls. Our results show a reasonable good agreement between the simulations and the experiments, at both heating and cooling considering the temperature hysteresis effect in the PCM. The temperature stabilization ability of the PCM is clear, in both the simulations and the experiments, and particularly in the data when the transition range of the PCM is fully activated and matching the temperature variation in the wall at that particular PCM position. Our ex-FEM tool has here been proved to be able to predict the thermal performance of simplified wall constructions of multiple layers with PCMs incorporated.
Status assessment of buildings using existing data and identifying gaps in data from performance indicators
Authors: Mandinec Jan , Johansson Pär 
Published: December 2021

Abstract
In past decades, several performance indicators have been developed allowing to objectively assess current status or predict failures of material, components and other factors like moisture safety. However, each performance indicator requires its unique sets of data, which are often difficult to obtain. It is therefore of interest whether a combination of several indicators is applicable in older buildings which often lack readily available documentation. The aim of this study is to identify data gaps preventing the use of indicators and to ascertain whether missing data can be filled by combining visual inspections and non-destructive testing. The first part of the paper summarizes known building envelope related indicators and arrange them into three groups: general, hygrothermal and service life performance indicators. The second part is a case study where the applicability of selected performance indicators is tested against an in-house database consisting information about 610 buildings in Gothenburg. It was found that the use of performance indicators is limited as the gaps in the available data are present for all types of performance indicators. The material composition of buildings envelope was identified as the most substantial gap. This limited the use of hygrothermal performance indicators in 58.5% of the buildings.
Determining the impact of sensor orientation on moisture content measurements in eastern white pine
Authors: Daouk B , Baldwin C , Cruickshank C A 
Published: December 2021

Abstract
As buildings become more airtight and insulated, the movement and accumulation of moisture within building envelopes become paramount in determining its resiliency. Current methods for quantifying the moisture content (MC) of wood species involve the measurement of electrical resistance between two installed electrodes and the use of existing empirical correlations to evaluate the MC. However, these correlations do not adequately consider the impact of sensor orientation within wall assemblies. The objective of this paper is to determine the impact of MC readings within a wood sample due to sensor orientation. A total of 126 eastern white pine samples were tested with electrodes placed along the grain of the wood (longitudinal), across the grain of the wood (tangential), and in a diamond pattern, using six different fasteners as electrodes. The samples were placed in a controlled environmental chamber until steady state was achieved at approximately 18% MC. Electrical resistances of the samples were measured in both directions at temperatures ranging from -10°C to 40°C. It was found that the tangential-to-longitudinal resistance ratio is 1.1-1.35 depending on the electrode type.
Stochastic simulation of rain intrusion through small defects due to water rivulet overpressure. Introducing a driving rain leakage potential
Authors: Hagentoft C.-E. , Olsson L. 
Published: December 2021

Abstract
There is a need of upgrading the old building stock with respect to the thermal insulation of the building envelope and specifically the façades. There are several systems on the market, and some are quite new and innovative. To bring down the cost some of the systems many are based on prefabricated moisture tight insulated units. This means that in case there is moisture tight barrier on the interior side, two moisture tight barriers surround the wall structure. The leakage of driving rain into the structure then represents a major threat to the durability of these systems. This paper investigates the pressure build up in water rivulets running down a façade acting together with the wind pressure. A driving rain leakage potential is introduced. Using real weather data years and Monte Carlo Simulations, the mean and standard deviation of the annual leakage through small hole is estimated. The examples show that the leakage can reach a level 0-0.5 liter/year for a hole with a diameter of 1-2 mm, and 0.5-3 liter/year for a diameter of 3-4 mm.
Moisture related challenges in the Greenlandic building sector – results from a survey
Authors: de Place Hansen E J 
Published: December 2021

Abstract
The building industry is booming in the larger cities of Greenland; there is a need for housing, and the building stock is in urgent need of renovation, mainly due to the combination of extreme weather conditions and the lack of tradition to maintain buildings. The harsh climate with short summers and long periods of cold weather combined with occasionally high wind speed and precipitation makes it difficult to prevent moisture during the construction phase, causing high drying costs. These challenges highlight the need for guidelines on how to handle moisture especially in the construction phase, both at renovation or when erecting new buildings. To prepare the guidelines, a survey was carried out aimed at building professionals in Greenland. Focus was on identifying construction work challenged by the conditions in Greenland including geography and seasons. The feedback gave an overview on the main challenges and what kind of solutions that do or do not work, showing that handling of moisture in the construction phase is not the only problem. Further, the survey gave feedback on challenges related to specific technical solutions, e.g. crawl spaces, and what kind of information is missing in relation to moisture-safe construction in Greenland. As key-points, focus should be on project design, improved competences, handling of building materials and components at the building site, and explainable guidelines for specific solutions and building types.
Hygrothermal simulations of timber-framed walls with air leakages
Authors: Laukkarinen A , Jokela T , Moisio T , Vinha J 
Published: December 2021

Abstract
Air leakages can create substantial excess moisture loads into envelope structures and degrade their hygrothermal performance. Multiple previous research projects have studied the behaviour and modelling of air leakages in building physics applications, but it is still quite rare to see air leakages being considered in practical building design simulations. The purpose of this paper is to present the selection of input parameters for air leakage simulations, utilisation of a factorial design to manage simulation cases and the results for a timber-frame wall with and without air leakages. According to the results, the air permeability of mineral wool and the air pressure difference over the envelope were the two most important factors for the dry air mass flow through the structure, as opposed to gap width and leakage route. An ideally airtight structure had a better hygrothermal performance compared to leaky structure. However, when leakages were present, the exact yearly average air flow rate in the range 70…420 dm3/(m2h) did not have a strong correlation to the performance indicators. For the other studied variables, the existence of a 50 mm thick mineral wool insulation on the exterior side of the gypsum board wind barrier and the impacts from climate change had the biggest effect on the moisture performance of the structure.
Numerical And Experimental Study Of A Supply Air Wall Based On Integrated Insulation Clay Hollow Blocks
Authors: Bouvenot JB , Egg M 
Published: December 2021

Abstract
Integrated insulation clay hollow blocks is an interesting constructive system in the context of Near Zero Energy Buildings and building energy efficiency. Their simple modification into supply air wall can increase their thermal performance without great effort. This paper deals with the creation of an original supply air wall or window test bench and with the numerical and experimental study of a supply air wall (or ventilated wall) based on modified modern integrated insulation clay hollow blocks where large cavities (about 4 cm) are filled by mineral wool. In some cavities, mineral wool is removed to create a flow pattern, which aims to recover heat losses from inside and solar energy from outside. At first, a 3D CFD numerical model is presented to assess the energy performance of a 1 m2 sample of ventilated wall. Then, an experimental test bench, based on a modified guarded hot box simulating solar effects and airflows between the two chambers, is carried out to assess the real performances. A comparison between these two studies allows validating the results which show a good correlation in terms of temperature difference gains between outdoor temperature and pre-heated temperature going up to a maximum of 14 K for only 1 m2 of wall and for a volume flow rate of 4 m3/h (4,5 K for 32 m3/h).
A novel concept for energy-efficient floor heating systems with minimal hot water return temperatures
Authors: Smith Kevin Michael , Hu Nan , Østergaard Dorte Skaarup , Svendsen Svend 
Published: December 2021

Abstract
The study proposed and investigated a new concept for hydronic floor heating in dwellings with the aim of reducing hot water temperatures toward a more robust and energy efficient operation. Modern heating systems often rely on low return temperatures to improve operation efficiencies through reduced heat losses from return pipes, greater utilisation of condensation heat from boiler flue gases or from the increased COP of heat pumps. Our study investigated the potential of using an apartment heating substation (or ‘flat station’) to supply space heating through two mixing loops using hot water supply temperatures of 30°C to bathrooms and 24°C to all non-bathrooms. The concept sought to minimise hot water supply temperatures to utilise a self-regulating effect while ensuring low return temperatures. In the first iteration of the concept, the high-temperature return water from the bathrooms was cascaded to the non-bathrooms to heat these rooms and provide further cooling of the hot water. The calculated energy-weighted return temperature under this original concept was 25.6 °C for the example case of a new energy-efficient apartment building. However, there was limited potential to utilise the cascaded coupling, so considering the complexity of its configuration and controls, the authors simplified the proposed concept to two mixing loops without a cascaded coupling. The calculated return temperature with the updated concept was 25.7 °C. The control of the floor heating included some aspect of self-regulation because the heat transfer strongly depended on the indoor temperature. Based on the results of this preliminary investigation, the concept may provide a robust and energy-efficient option for configuring floor-heating systems in situations that rely on low hot-water return temperatures.
A simple method for validating a simulation model of a radiant ceiling panel with thermal energy storage
Authors: Gallardo Andres , Berardi Umberto 
Published: December 2021

Abstract
This paper focuses on validating a simulation model of a radiant ceiling panel (RCP) incorporating phase change materials (PCM) for heating and cooling applications in buildings. The development of an RCP with thermal energy storage capacity aims to encourage high thermal mass radiant systems in existing buildings to replace the traditional all-air HVAC system. First, a heat flow meter (HFM) is used to perform enthalpy measurements at a product scale (macro-encapsulated PCM). Then, a small test chamber is constructed to measure the dynamic thermal performance of an RCP with PCM under well-known and realistic boundary conditions. A known thermal resistance is used to establish a realistic heat transfer coefficient between room air (represented by the temperature of a temperature-controlled metal plate) and ceiling. The results show that HFM enthalpy measurements of products incorporating PCM are within ± 2% of manufacturers’ data. Additionally, results indicate that a test chamber can be used for validating a dynamic simulation model of the RCP with PCM installed in a room. The proposed method can be helpful during the system optimization phase, as many conditions and sample configurations can be tested without spending too much time or money on test rooms or real building monitoring.