bluuebunny/crossref_metadata_2025 huggingface dataset:
Highly insulated crawl spaces with controlled minimal ventilation – proof of concept by field measurements
Authors: Airaksinen Miimu , Olsson Lars , Kurnitski Jarek , Hvidberg Staffan
Published: June 2020

In current practices crawl spaces are typically ventilated with outdoor air. This leads very often to high relative humidity especially in the beginning of the summer, which can be problematic if the excess humidity cannot be ventilated efficiently enough. This paper introduces a crawl space concept where the crawl space is highly insulated and traditional ventilation openings are replaced by minimal mechanical exhaust ventilation set by pressure difference with the aim to prevent potential pollutants to penetrate indoors through the base floor. The concept that has been developed based on the simulation study is tested in this study with field measurements in four single family houses. Continuous measurements of relative humidity and temperature in crawl spaces and outdoor air were running more than one year in each building. The results revealed that all the crawl spaces had very low relative humidity, mostly below 75% and for very short periods close to 80% even though some of the buildings were new and construction phase moisture was drying out. The results revealed that the crawl space concept studied provided an ultimate moisture safety and can be recommended for all buildings with wooden floor.
Treatment of condensation in sandwich panels without known vapour resistance of sealant
Authors: Vidmar Gregor
Published: June 2020

In order to calculate amount of interstitial condensation in a building envelope, water vapour resistance of each layer is of importance. Once having it, 1D calculation according to ISO 13788 with monthly average vapour pressures can be applied. In EN 14509 sandwich panels are considered to be impermeable for water vapour, thus (according to the standard) water vapour cannot enter from outside and condensate in the panels. But it is not always true for real sandwich panels, because joints between neighbouring panels can cause non-neglecting water vapour bridges. Although in measurements of linear water vapour transmittance of the joints (Ψv) stationary boundary vapour pressures can be applied, the measurements can be long lasting. We shortened time needed to get Ψv performing simulations in Delphin 6.0. We simulated panels and steel sheets with joints using constant boundary vapour pressures and compared the results with the results of measurements on the equivalent systems.

In systems under consideration a sealant in built-in-state, located at a joint of a sandwich panel, is a compressed EPDM tube. It is impossible to directly measure its effective μ according to ISO 12572. In the paper we study to which precision it is possible to determine it using measurements and simulations. Once having effective μ of the sealant (if all other necessary material parameters available) one can simulate condensation in envelopes including sandwich panels in 2D according to EN 15026 using hourly climatic data. Another goal of the study was determination of differences in resulting Ψv values when varying narrowest part of the gap dGAP at the joint in the panels without any sealant. Results confirm significant sensibility of Ψv to variations of dGAP.
Stochastic generation of multiscale 3D pore network models of building materials
Authors: Claes Steven , Janssen Hans
Published: June 2020

The current experimental determination of hygric properties of porous building materials are demanding in time and effort, merge ad- and desorption techniques, fuses static and dynamic methods, and finally do not yield complete nor robust results. Therefore, numerical pore-scale-based prediction of the hygric properties of building materials is on the rise as an alternative. For building materials, this is mostly based on pore network modelling (PNM), given that these are more efficient compared to lattice Boltzmann or particle hydrodynamic methods. Pore network modelling however requires data of the complete pore network for the building material. With the currently available characterization and visualization techniques, this cannot be readily obtained, as the pore sizes in building materials often span several spatial scales. The aim of this paper is to present a scale invariant stochastic generation. To realize this objective, distributions of direct parameters (pores’ sizes, shapes, positions, connections, ...) as well as indirect parameters (overall pore size distribution and open porosity value) are derived from the input data obtained by micro-CT and FIB-SEM and subsequently applied to generate a complete pore network of the porous building material. The quality of the generated PNMs is assessed by comparing them to the original PNMs.
Two-dimensional hygrothermal modelling of masonry walls accounting for imperfections at the masonry joint
Authors: Gutland Michael , Bucking Scott , Santana Quintero Mario
Published: June 2020

Hygrothermal models are important tool for assessing the risk of moisture-related decay mechanisms such as freeze-thaw in historic masonry structures. There are several sources of uncertainty when modelling masonry, related to material properties, boundary conditions, quality of construction and twodimensional interactions between mortar and unit. This paper examines one potential source of uncertainty; the imperfect nature of mortar joints. This interface may feature hairline cracks or imperfect bonds which can be modelled as a fracture. This will alter the rate of liquid transport into and out of the wall and impede the liquid transport between mortar and masonry unit. This means that the “effective” liquid transport of the wall system will be different then if measured properties of the bulk material were modelled. A detailed methodology for modelling the interface as a fracture is presented including material property definition. Two-dimensional DELPHIN models of masonry walls were created to simulate this interaction with varying levels of fracture widths (apertures). A series of hygrothermal simulations were performed to demonstrate change in moisture profile from the baseline condition. A significant increase in moisture absorption was found. This was dependent on aperture size, material and the relative size of the masonry modelled.
Design criteria for outdoor air intakes and exhaust air outlets located on an external wall
Authors: Palmiste Ülar , Kurnitski Jarek , Voll Hendrik
Published: June 2020

Optimal placement of outdoor air intakes and exhaust outlets is a source control measure to avoid the degradation of air quality at the air intakes. Re-entrainment is an occasional air pollution instance that happens if pollutants in the exhaust air stream, after being discharged to outdoors, are transferred back to outdoor air intake location due to unfavorable meteorological conditions and inadequate positioning of the air intakes and exhaust outlets. In engineering practice, it is impractical to always conduct detailed dispersion modeling due to the complexity of airflow phenomena in the urban environments, and therefore, engineers rely on prescriptive design guidelines or simplified empirical models published in technical literature and regulation documents. Commonly, the design guidelines to avoid the re-entrainment phenomenon are for buildings with rooftop exhaust stacks, but the exhaust outlets might also be situated on the building façade. The objective of this paper is to overview the existing design guidelines for the placement of horizontal air intakes and exhaust outlets. Technical engineering literature, including international standards, codes, and guidebooks is reviewed to extract both qualitative and quantitative design guidelines relevant to the placement of air intakes and exhausts on an external wall.
Analysis of Natural Ventilation Performance Gap between Design Stage and Actual Operation of Office Buildings
Authors: FU Xiuzhang , HAN Mingzhu
Published: June 2020

Suitable natural ventilation in office buildings can not only reduce energy consumption of air conditioning, but also improve indoor air quality. In the architectural design stage, the effect of natural ventilation design is mainly simulated by CFD simulation software for indoor air speed, pressure, and age of air, etc.. However, during the actual building operation, the indoor natural ventilation effect will be affected by many factors, such as surrounding buildings, indoor layout, window position and open-close status, human behavior, etc., and the natural ventilation performance between design stage and actual operation is often different. In this paper, a typical office building was selected and FloVENT software was used to quantitatively analyse the influence of surrounding buildings, indoor layout, door/window opening conditions on indoor natural ventilation. Field measurement of indoor air flow rates in typical positions in office were carried out under different circumstances. In order to reduce the instantiate influence of outdoor wind speeds, a new index named Wind Speed Ratio(WSR) is put forward.Through comparative analysis of simulated data and measured data. the gap degree in natural ventilation performance between design stage and operation operation is discussed, and results show that the relative errors of the WSR, which could be considered to reflect the performance gap, are about 78.0%, 28.7% and 150% respectively, under corresponding condition settings of surrounding buildings, indoor layout, and door/window opening.
Investigating the presence of mold in wood treated with chlorophenol
Authors: Ekberg Olle , Lorentzen Johnny C. , Harderup Lars-Erik
Published: June 2020

A common moisture-related problem in Sweden and other countries, is mold odor indoors. The general perception is that mold odor indicates hazardous hidden mold. However, some grey literature studies indicate that the source of mold odor might not be substantial amounts of mold, but rather chloroanisoles (CAs) which are biomethylated from chlorophenols (CPs) in moist conditions. Products containing CPs were commonly used world-wide as wood preservatives in the 1960-70s and problems with indoor mold odor have been reported in buildings where such products have been used. In Sweden, one of the main uses of CPs in buildings was in wooden constructions exposed to big moisture loads, such as sill plates and crawl space ceilings. Here we aimed to determine the potential presence and level of mold growth on wood treated with CPs in one school building with reported odor problems built in the stated time period. Odorous wooden samples were taken and analyzed for mold growth. No mold was detected by the naked eye, but some growth was seen using a microscope. We presently investigate more schools and samples, but so far our results question that mold odor depends on substantial amounts of mold.
Climate data analysis to assess resilience of wall assemblies to moisture loads arising from the effects of wind-driven rain
Authors: Xiao Zhe , Lacasse Michael A. , Gaur A. , Dragomirescu Elena
Published: June 2020

In North America, and abroad, there currently exist standard test protocols for assessing the watertightness of wall assemblies and fenestration components although most of these methods are not directly related to expectations of in-field conditions as might be experienced by a wall assembly over its intended service life. How useful might such test protocols be to help determine the longevity of wall assemblies to future climate loads? Existing walls may, depending on their geographic location, be vulnerable to future climate loads and thus risk premature deterioration. For the design of new wall assemblies consideration ought to given to the non-stationarity of the climate and implications on the moisture loads on walls and the expected performance over the long-term. To permit assessing the resilience of wall assemblies to the effects of a changing climate as may occur in the future, and indeed, perhaps heightened moisture loads, one requires sufficient information on the watertightness of the assembly in relation to specified wind-driven rain loads and wall air-leakage conditions from which wall moisture retention functions could readily be developed. Such moisture functions are the basis of input of moisture loads to hygrothermal models and from which the expected long-term wall moisture performance can subsequently be derived. In this paper, a description is provided of the strategies used to analyze the WDR load for generating experimental input for a watertightness test protocol under development to assess resilience of wall assemblies to moisture loads arising from the effects of wind-driven rain in consideration of both historical climate loads and those as may arise from a changing climate.
Utilization plasters with superabsorbent admixture to moderate moisture level in constructions
Authors: Fořt Jan , Hotěk Petr , Kočí Jan , Černý Robert
Published: June 2020

The level of indoor humidity has to meet several criteria according to the preservation of a healthy indoor climate for building inhabitants. On top of that, the undesired moisture content is associated with a proliferation of various organisms which results in an adverse effect on the durability of building materials. Facing the impact of climate change and excessive energy consumption associated with building maintenance, the employment of passive moderation techniques takes place to avoid the usage of energy-demanding HVAC devices. The application of advanced materials such as superabsorbent polymers (SAPs), commonly used in diapers or other hygiene products, can bring a very effective solution for this issue overcoming. In this paper, the effect of 0.5; 0.1 and 1.5 wt.% dosages of SAPs incorporated into a cement-lime plaster are studied to evaluate the material performance in the sense of moisture moderation. First, the basic material properties, moisture transport and storage properties, thermal conductivity and specific heat capacity are determined to access the influence of SAP admixtures on the functional performance of studied plasters. Consequently, the experimentally accessed results are further employed for the computational modeling analysis which evaluates the capability of studied plasters for the moderation of moisture content in constructions.
Evaluating the Practicability of the new Urban Climate Model PALM-4U using a Living-Lab Approach
Authors: Winkler Matthias , Steuri Bettina , Stalder Sebastian , Antretter Florian
Published: June 2020

Numerical urban climate models have the potential to be commonly used tools in urban development processes in practice. With integrated modules for building and envelope simulation these complex models allow the assessment of measures in the building sector on the urban climate, e.g. for mitigation of urban heat island effects or preparing for the effects of climate change. However, the currently existing models do not fulfil the requirements that arise in the field of urban planning, as they lack for example functionality, user-friendliness, are hard to integrate in the municipalities’ technical equipment or are not freely available. The German research and development project Urban Climate under Change (2016-2019) developed and validated a new innovative urban climate model called PALM-4U. Aim of the research was to create a model that meets the requirements of users in science as well as practitioners in engineering offices and urban administrations. Therefore, technical features and operational functionalities which the model has to meet to support users in their daily work have been assessed in a first project phase. In total more than 200 requirements were collected which are summed up in the so called “User and Requirements Catalogue”. They served as the basis for testing and evaluating the model’s real-world applicability. To ensure that these complex requirements are met, the whole project follows a transdisciplinary approach integrating science (model development and data assimilation) and practice (user requirements, testing and evaluation) applying a living lab approach: Stakeholders from participating cities and companies took part in on-site workshops, introducing the model with practical use-cases. Afterwards, participants were given tasks covering different features of the model’s applications, which they tested in personal use. The model fulfils the majority of the tested requirements and the users appreciated the model’s concept and functionality. But further development is necessary to provide the practitioners a tool that is applicable in their daily work: Preparation of input data, a user-friendly graphical user-interface, enhanced interfaces to other software and planning tools, use cases that were prepared from experts as well as guidelines and tools for result assessment and interpretation were main suggestions for improvement..
Modelling Multi-layer Hydronic Radiators
Authors: Chen Liguo , Sørensen Bjørn Reidar
Published: June 2020

This report simulates Purmo type C22 and C33 radiators with both standard calculation and heat transfer method with help of Matlab/Simulink. Simulation results are presented to describe the radiators’ thermal performances with different simulation strategies. The deviations between two different calculation methods are identified and the heat transfer radiator model can be improved with more investigations regarding thermal dynamics and controlling strategy. Under simulation scenarios of simple room model with a PID controller, type C33 has shorter response time and faster stabilization of room temperature; and it has lower outflow temperature, which implies higher energy efficiency.
Integration Of Pipe Models In Delphin And NANDRAD
Authors: Weiß Dirk , Tribulowski Katja , Hirth Stephan , Fechner Heiko
Published: June 2020

The component simulation program DELPHIN, which is usually used for component simulation including coupled heat and moisture transport, has also implemented a pipe model that is currently not documented. This model can be used for various purposes, including the modelling of heat input/output by surface heating/cooling systems in building structures. Furthermore, it allows an estimation of energy gains and storage potentials by ground collectors by considering the ground including the collector pipe, etc. The same pipe model is implemented isotropically in NANDRAD in order to model and to consider underfloor heating systems in the thermal building simulation. The implementation of this pipe model for DELPHIN (component simulation program) and NANDRAD (building simulation program) is described, investigated and documented in this paper for underfloor heating and cooling systems. Especially the heat transfer between pipe wall and fluid is discussed in more detail. Therefore, the parameterization and the flaw between the anisotropic tube model (two-dimensional heat radiation inside the component) in Delphin and the isotropic model (heat input to a component layer) in NANDRAD are being examined.
The tin can method for determining moisture transport properties of concrete
Authors: Nilsson Lars-Olof , Bergström Kent
Published: June 2020

Traditional methods for measuring moisture transport properties of concrete are time-consuming, especially since thick specimens are required, and steady-state methods are preferred. Non-steady state methods may be an alternative but the conditioning to uniform initial conditions is extremely difficult. The tin can method is, however, a good alternative under certain conditions and for certain concretes. Concrete is poured into a tin can and sealed cured in this way for at least a month. The can is opened, and the concrete is dried in a constant climate. Weight changes are recorded for several weeks. From these weight changes, the initial RH at start of drying, the drying climate and the desorption isotherm, the moisture transport coefficient or the moisture diffusion resistance factor are derived. The paper describes the theory behind the method and the unique conditions available for certain concretes that makes the method applicable. Examples of measurements are shown for a number of concretes and verification is done with the cup method on the very same concretes, with excellent results.
Measurements of thermal Transmittance of an External massive timber wall in-situ and in the Laboratory
Authors: Geyer Christoph , Müller Andreas , Wehle Barbara
Published: June 2020

The thermal transmittance of an exterior massive timber wall was measured in situ in Appenzell, Switzerland according to the standard ISO 9869-1. The measurements were performed with two different measurement sets in parallel. The measurements started in February and stopped at end of April. The measuring data were analyzed using mean values of the thermal transmittance coefficient and of the thermal resistance following the procedure of ISO 9869-1. In order to clarify if the in-situ measurement results show significant deviations from the measurement results of the thermal transmittance obtained in the laboratory, the thermal transmittance of the identical wall construction was measured in the laboratory of Bern University of Applied Sciences in Biel according to the standard EN ISO 8990 for steady state boundary conditions in a guarded and calibrated hot box. The test results will be presented and the measurement setup will be described. The calculation value of the thermal transmittance coefficient of the massive timber wall according to EN ISO 6946 is U = 0.53 W/(m2K). The test results of the thermal transmittance coefficient, U-value of the wall, measured in the hot box, agreed well within a confidence level of 95 % with the calculated value. The in-situ measurement results of the thermal transmittance coefficient of the two measurement sets differ significantly in the order of 8 % referred to the calculated U-value of the wall as the basic amount. Furthermore, both in situ test results of the U-value of the wall show significant deviations from the calculated U-value up to 27 %.
Influence of Occupant Behaviour on the State of Charge of a Storage Battery in a nearly-Zero Energy Building
Authors: Pereira Pedro F. , Ramos Nuno M. M.
Published: June 2020

The development of nearly zero energy buildings (nZEB) is a goal being set for many countries for the next years. In order to achieve that goal, on-site energy generation is needed, and the use of photovoltaic and storage systems is a possible strategy. Hence, the objective of this work is to evaluate the impact that occupant behaviour has on the batteries energy storage systems (BESS) of an nZEB. This study considers as a case study an nZEB with lightweight construction, located in the university campus, and used by different occupants. The case study has 12 PVs located on the root and a second-life BESS from an electrical vehicle (EV). The monitoring system consists of interior T, RH, CO2 and energy sensors and an exterior on-site meteorological station. The research started with a state of the art review of the support policies for the on-site photovoltaic generation and energy storage. Different storage charge profiles were obtained as different occupant behaviours were applied to the test building. In total, it were considered three occupant profiles and a base scenario was the unoccupied. The occupant behaviour showed to be determinant in the state of charge of the BESS independently from the impacts in the indoor temperature. The need to know the profile of the occupants before the design of the buildings was enhanced.
Achieving energy and resource optimisation within urban mixed use developments utilising passivhaus premium design strategies
Authors: Murray Martin
Published: June 2020

Cities in 2020 consume 75% of the world’s resources in the form of energy, water and materials; 55% of the world’s population live in these urban environments and by 2050 this figure is expected to rise to 65%. These facts combined with the reality that residential energy use alone, accounts for almost 40% of global energy emissions indicates that the challenge of reducing our profligate use of residential energy, and thus reducing our greenhouse gas emissions, is first and foremost an urban challenge and opportunity. The theme of this paper is prioritisation. By prioritising the development of low rise, integrated-mixed-use developments we are facilitating energy use in the most efficient and beneficial way, toward achieving these reductions. Furthermore the paper argues that such developments are also societally enriching by the creation of another layer of understanding of the urban environment, achieved through reflecting key energy engagements between buildings, uses and sites. The energy logic of such mixed use developments is further justified and enabled, if combined with the reuse of serviced ‘brownfield’ urban sites, a variety of user profiles, long life facilitation of habitation use, and resource efficiencies; all achieved whilst facilitating low carbon living at an urban microscale.
Laboratory tests and modelling of mineral wool insulated steel sandwich panels
Authors: Laukkarinen Anssi , Vinha Juha , Kalbe Kristo , Kesti Jyrki , Kalamees Targo , Honkakoski Erkki
Published: June 2020

This study presents results from laboratory measurements of mineral wool insulated steel sandwich panels. The purpose of the work was to have a better understanding on the heat and moisture conditions inside sandwich panels and to study how the structure behaves in water leakage situation. The tests were done by sealing the structure from all sides and regulating the temperature on one side of the test structure while measuring the temperature and relative humidity conditions inside the structure. Water leakages were created by injecting liquid water onto the insulation layer. According to the results, water vapour pressure differences stayed relatively small both in stationary and dynamic conditions. This implies that the limiting factor for moisture source was the evaporation rate from the water leakage and that the vapour pressure throughout the insulation layer is determined strongly by the vapour pressure at the possible condensation layer. The paper discusses also the determination of sensor accuracy and impacts of a thermal bridge from the probe itself. Also, measurement results from a new radio wave monitoring method are presented.
Establishing material hygrothermal characteristics via long-term monitoring and best-fit numerical models
Authors: Birjukovs Mihails , Apine Inga , Jakovics Andris
Published: June 2020

Numerical models of heat and moisture transfer for performance forecast of lightweight insulating assemblies require many inputs. These include exterior climate data (i.e. temperature, relative humidity, solar radiation), interior climate data or standard models, transfer coefficients, correct initial conditions, etc. Most importantly, one needs reliable material models. A material model includes porosity, density, heat capacity, but also non-constant properties, such as thermal conductivity, vapor/liquid water diffusivity, sorption curves. These are, in general, difficult to determine, and material database entries often are incomplete, or simply non-existent. However, if one performs long-term monitoring of temperature and relative humidity dynamics within building envelopes, there is a way to determine hygrothermal curves and properties of the underlying materials. This can be done by performing simulations and finding the set of optimal hygrothermal curves and coefficients such that the experimental data is matched sufficiently well. Despite the appeal, this best-fit model approach is fraught with perils due to many unknowns and must be used carefully. In this article, we demonstrate the application of this method to insulating assemblies for which 6+ years' worth of experimental data is available, and showcase our results obtained using WUFI Pro 6.3 and the derived and verified material models.
Preliminary assessment of preconditions to deliver carbon neutrality in apartment buildings by 2050
Authors: Lihtmaa Lauri , Kalamees Targo
Published: June 2020

Member states of European Union have large stock of residential buildings that require urgent renovation in order to reach carbon neutrality by 2050. In our paper we provide a preliminary evaluation of preconditions of such goal within the context of shrinking regions. Our data originates form renovation subsidy database of large renovation programme managed by state fund and form Nation Statistical Bureau. First we estimate the potential of apartment buildings occupation within the next 30 years. We exclude buildings that are going to be abandoned due to the demographical and migration reasons. Next we calculate the potential of construction sector to deliver required amount of renovations. We observe that the in our case current renovation rate must at least be increased by factor of three in order to comply with the carbon neutrality goal. This, however, is very challenging because supply of renovations’ construction is limited and overstimulated demand could increase construction prices significantly while rendering the effect of state incentives inefficient. Therefore an urgent technological change in renovation delivery is required to reach carbon neutrality goals.
Nearly zero energy renovation concepts for apartment buildings
Authors: Kuusk Kalle , Naumann Jens , Gritzki Annina , Felsmann Clemens , De Carli Michele , Tonon Massimo , Kurnitski Jarek
Published: June 2020

Revised EPBD directive has set ambitious targets for renovation. It is stated that Member States shall establish a long-term strategy facilitating the cost-effective transformation of existing buildings into nearly-zero energy buildings. The long-term strategy should set out a roadmap with a view to the long-term 2050 goal of reducing greenhouse gas emissions in the European Union. This creates the need for cost-efficient renovation solutions which can be implemented in large scale. The impact assessment shows that roughly a doubled renovation rate of 3 % would be needed to accomplish the energy efficiency ambitions in a cost-effective manner. The objective of this study is to specify renovation concepts with adequate heating and ventilation, based on Estonian and German apartment buildings and corresponding local solutions. Energy performance and sizing analyses were conducted for selected multifamily apartment buildings typical for 1960-70es with three different renovation concepts. Energy calculations were conducted with national energy calculation methods and national energy requirements for major renovation. In the renovation, the building envelope insulation, air tightness, and heating and ventilation systems were improved so that the renovated building complies with national nearly zero-energy requirement for major renovation.
The Use of Solar Shading in a Nearly Zero-Energy Neighbourhood
Authors: Verbruggen Silke , Hertoge Jolien , Delghust Marc , Laverge Jelle , Janssens Arnold
Published: June 2020

The use of solar shading can have an important influence on the internal heat gains, especially in zero-energy buildings. However, the research in literature is almost uniquely focused on offices, while information on the use of solar shading in residential dwellings is lacking. Therefore, the solar shading behaviour of occupants of a nearly zero-energy social housing neighbourhood in Belgium is analysed. Data are gathered by solar shading logging with a building monitoring system, logbooks and cross-sectional surveys. In general, the solar shades were not often adjusted, with many of the solar shades either always opened or always closed. Clear seasonal influences were observed; however, the temperature and solar irradiance did not reveal a significant relationship with the use of the solar shading. This relationship could be biased by the fact that some of the occupants use the solar shades not to prevent solar heat gains but to darken the room in the evening (blinds). Since the shades are not often adjusted and are thus in the same position for a long time, the use is independent of the prevailing weather conditions. The position of the solar shades seems to be more influenced by the personal preference of the occupant than by external factors. Additional simulations, carried out with Modelica, showed that when the full capacity of the solar shades is used, the overheating can be decreased up to 29% in south oriented rooms. The possible negative impact on the heating demands can be neglected. This shows the necessity to correctly model the solar shading behaviour in residential buildings, especially in nearly zero-energy buildings, for which the cooling demands are increasingly important.
The Ventilated Building System
Authors: Wasenius Birger E.
Published: June 2020

The accelerating climate change greatly streches the demands of sustainable methods of building safe and sound low energy buildings. Because of the increasingly moist climate wooden constructions are risky, thus moisture safe stone constructions are the right solution. The Palikka engineers have foreseen this development already 50 years ago, thus developing the Palikka® Original Building System with built-in ventilation properties.
Performance analysis of solar assisted ground coupled heat pump system in Latvia
Authors: Migla Lana , Snegirjovs Andrejs , Shutenkova Olga
Published: June 2020

Today, with the increased popularity and availability of renewable energy sources the question of ensuring a proper household heating, that is energy, is not as complicated as it used to be. Users are embracing the environmental sustainability stand and are turning to heat pumps and solar panels as means of providing heat for their homes. The geothermal heat pump and solar thermal panels energy efficiency rates coupled make these the perfect choice for those, who are concerned about the impact they make on the environment-aspiring to zero emission buildings. The combined system of solar thermal panels and ground source heat pump for heating capacity 13 kW will be developed. The main novelty is the investigation of a new type of a solar thermal accumulation tank. Hypothetically this solar assisted ground coupled heat pump system should reach COP rate 4 and reduce electricity demand consumption by 40%. To find out the truth of proposed thesis, the research will be carried out. Both simulation and real-life object data analysis will be performed. As a result, the potential of such a system in northern latitudes will be determined.
Design and monitoring of energy-active facade module
Authors: Pokorny Nikola , Matuska Tomas , Jirka Vladimir , Sourek Borivoj
Published: June 2020

Testing of two facade modules under outdoor climatic conditions of Central Europe has been performed for more than two years. The paper analyses the results of long-term monitoring and shows potential benefits of prismatic glazing and photovoltaic-thermal (PVT) collectors integrated into one component. The prismatic glazing reflects beam radiation during summer period and transmits it during the winter period. During summer month solar irradiation transmitted through the prismatic glazing can be about 44 % lower compared to conventional triple glazing. Glazed PVT collector generates heat and electricity simultaneously. PVT collector integrated in the façade module can achieve solar yield during summer 58 kWh/m2.month in heat and 6,3 kWh/m2.month in electricity.
Studies on internal surface heat transfer in the window area
Authors: Tywoniak Jan , Stanek Kamil , Kny Martin , Adamovský Daniel
Published: June 2020

In this paper reporting preliminary results from the ongoing research, heat transfer phenomena at window surfaces and adjacent areas of the building envelopes are studied. In the first step, in-situ observation of balcony door based on indirect estimation of temperature distribution close to window surface was carried out by means of infrared imaging (IR). In the second step, more advanced full-scale experiments were performed in a well-insulated laboratory testing room with floor heating, equipped with one window, under well controlled steady-state conditions. A combination of IR with particle imaging velocimetry (PIV) was used here with extra focus on situation close to the window frame at window sill. In such areas the reduced heat transfer by convection can be observed. As a consequence, the condensation risk free situation there seems not to be always guaranteed even by high performing building components despite the results of standard heat transfer calculations used in design practice.
Computer Vision-based Reader for analogue Energy/Water Meters in low-cost embedded System: a Case Study in an Office Building in Scotland
Authors: Adalberto Guerra-Cabrera , Giulia Barbano , Giovanni Tardioli , Girish Mallya Udupi
Published: June 2020

Implementation of cost-effective energy conservation measures (ECMs) is expected to generate up to 18% of carbon emissions reductions in office buildings. In order to determine adequate ECMs for a specific building, operational data is required. However, buildings generally lack operational data in the form of time series that can limit a breath of analysis required for determining adequate ECMs. Energy time-series data is commonly lacking in the UK due to uneven availability of smart meters (heat, gas, water), security restrictions in Energy Information Systems (EIS) and building management systems (BMS), restrictions and costs associated for automated reporting from utility companies, etc. This work presents a non-intrusive computer vision-based reader to generate energy readings at 10-minute resolution using a Raspberry-Pi, a traditional webcam and an LED light. OpenCV, an open source computer vision library, is used to detect and interpret numeric values from a heat meter, which are in turn uploaded to a cloud-based energy platform to create a complete operational data set enabling detailed analytics, fault detection and diagnostics (FDD) and model calibration. A case study of an office building in Scotland is presented. The building has a heat meter with no remote access capabilities. The accuracy of the method, i.e. the ability of the script to accurately derive the rate of change between readings, resulted on a 92% percent during a test done for 100 samples. Recommendations for accuracy improvements are included in the conclusions.
Application of artificial neuronal networks in extracting parameters of solar cells
Authors: Khalis Mohammed , Masrour Rachid
Published: June 2020

This paper presents a new neural network-based approach that aims to use the back propagation multilayer perceptual (MLP) propagation algorithm to improve the extraction of parameters from a solar cell based on the single-diode model from the experimentally measured characteristic I(V). The I(V) current function as a model function for the neural network, is used the Lambert function W and I can be expressed as an explicit function. The main five parameters of interest of the function I(V) are the photocurrent, Iph, the saturation current in inverse diode, I0, the ideality factor of the diode, n, the resistance in series, RS and shunt resistance, RSh. We have used the Matlab to find the five parameters of the cell. To verify the proposed approach, we chose two different solar cells made of mono- and polycrystalline silicon. The comparison between the measured values and the results of the proposed model shows great precision. Finally, the values found of the five parameters by our approach are compared with those found by the method of least squares (MLS).
From Astronomy to the clinic: Adaptive Optics based visual simulators
Authors: Viñas Maria
Published: June 2020

Adaptive optics based visual simulators with deformable mirrors, spatial light modulators or optotunable lenses are increasingly used to simulate vision through different complex multifocal lens designs. Their final utility in the clinic relies on their capability to predict visual performance after an ocular surgery.
The ERIC Consortium a new type of EU research institution
Authors: Rizzuto Carlo
Published: June 2020

The European Research Infrastructure Consortia (ERICs) are changing the landscape of the European Research Area. ERICs are set-up by EU Community law to establish and operate open access Research Infrastructures in all fields of science, based on national and international funding. The 20 + ERICs have now a major impact in extensive fields of research.
Cost-sharing contract in a closed-loop supply chain considering carbon abatement, quality improvement effort, and pricing strategy
Authors: Taleizadeh Ata Allah , Niaki Seyed Taghi Akhavan , Alizadeh-Basban Nima
Published: June 2020

The high competition in today’s market persuaded companies to provide some attractive options for products to obtain more market shares. Therefore, in this research, three motivating elements are devised in the framework of a two-level supply chain consisting of a manufacturer and a distributor under stochastic demand, where green production via carbon abatement, quality enhancement efforts, and returning and remanufacturing policies are used. In line with reducing carbon emission two possibilities are applied in this paper involving the green technologies investment and the trade and cap policy. As simultaneous consideration of all motivating factors raises conflicts between the members in terms of undertaking the costs, a cooperative supply chain, as well as a cost-sharing (CS) contract in non-cooperative form, is devised to alleviate the conflicts and boost the performance of the supply chain. In order to find the optimal decision variables and profits in the CS contract, two game-theoretical approaches, namely Nash and Stackelberg, are applied. The results present the sufficiently of both the cooperative chain and the CS contact. In addition, the analysis of parameters in the CS contract in Stackelberg game indicates that when the distributor undertakes a part of the costs, positive impacts on the other motivating factors are observed. However, there is no interaction among the motivating factors in the Nash game.
The edge geodetic self decomposition number of a graph
Authors: John J. , Stalin D.
Published: June 2020

Let G = (V, E) be a simple connected graph of order p and size q. A decomposition of a graph G is a collection π of edge-disjoint subgraphs G1, G2, … , Gn of G such that every edge of G belongs to exactly one Gi(1 ≤ i ≤ n). The decomposition π = {G1, G2, … , Gn} of a connected graph G is said to be an edge geodetic self decomposition, if ge(Gi) = ge(G) for all i(1 ≤ i ≤ n). The maximum cardinality of π is called the edge geodetic self decomposition number of G and is denoted by πsge(G), where ge(G) is the edge geodetic number of G. Some general properties satisfied by this concept are studied.
Bernoulli vacation model for MX/G/1 unreliable server retrial queue with bernoulli feedback, balking and optional service
Authors: Jain Madhu , Kaur Sandeep
Published: June 2020

The study of unreliable server retrial bulk queue with multiphase optional service is analyzed by incorporating the features of balking, Bernoulli vacation and Bernoulli feedback. On the occasion when the server is occupied with the service of the customers, an arriving customer finding the long queue, can join the retrial orbit and receives its service later on by making re-attempt. The system is reinforced with multi phase optional service along with essential service and joining customer can opt any one of optional services after getting essential service. Furthermore, the essential/optional service can be aborted due to abrupt failure of the server. There is an immediate support of multi phase repair facility to take care of the failed server, but sometimes repair may be put on hold by virtue of any unexpected cause. If the service is unsatisfactory, the customer can rejoin the queue as feedback customer. Bernoulli vacation is permitted to the server following the respective busy period. For evaluating the queue size distribution and other system performance metrics, supplementary variable technique (SVT) is used. The approximate solutions for the steady state probabilities and waiting time are suggested using maximum entropy principle (MEP). We perform a comparative study of the exact waiting time obtained by the supplementary variable technique and the approximate waiting time derived by using maximum entropy principle by taking the numerical illustration. Quasi Newton method is used to find optimal cost. To verify the outcomes of the model, numerical illustrations and senstivity analysis have been accomplished.
Geburtshilfliche Fisteln – Relevanz für Hebammen in Deutschland
Authors: Siebenkotten-Branca Veronika
Published: June 2020

Dank moderner Geburtshilfe und Medizin können Fisteln als geburtshilfliche Komplikation heute vermieden bzw. chirurgisch saniert werden. Tausenden Frauen bleibt
diese Versorgung jedoch versagt: Weltweit leiden mehr als eine Million unbehandelter Frauen und Mädchen unter den als traumatisch erlebten Folgen geburtsbedingter Fisteln wie Inkontinenz, Stigmatisierung und sozialer Ausgrenzung. Die Autorin vermittelt, warum geburtshilfliche Fisteln auch hierzulande ein relevantes Thema sind und was Hebammen für die Prävention wissen müssen.
Abgrenzungstatbestand der Fachleistungen des SGB IX und den Pflegeleistungen
im SGB XI – eine vergleichende Analyse
Authors: Mehmet Ali Takis
Published: June 2020

Das im Jahr 2016 verabschiedete Bundesteilhabegesetz (BTHG) tritt in
unterschiedlichen Reformstufen in Kraft. Im Jahr 2020 ist die 3. Reformstufe mit
den größten Änderungen in der Eingliederungshilfe
erreicht. Dabei geht die Eingliederungshilfe von der Sozialhilfe in ein eigenes
Leistungsrecht über und wird im 2. Teil des SGB IX implementiert. Eine
grundsätzliche Änderung ist der Wegfall der Differenzierung
zwischen ambulanten und stationären Wohnformen. Dementsprechend sollen
auch die dann zu erbringenden Assistenzleistungen nicht mehr in
Abhängigkeit von der Wohnform betrachtet werden, sondern individuell
(bzw. auch personenzentriert), bedarfsgerecht und ortsunabhängig. Die
heutigen Leistungen werden institutionsgestützt erbracht,
künftig sollen die Personenzentrierung und die individuellen Bedarfe im
Vordergrund stehen. Dabei steht das sog. Wunsch- und Wahlrecht des Menschen mit
Assistenzbedarf nach Vorgaben des §104 Abs. 1 und 2 SGB IX im
Vordergrund, sofern sie angemessen sind.
Die Rolle der perkutanen Koronarintervention in der Therapie des chronischen Koronarsyndroms
Authors: Widmann Laila , Blachutzik Florian , Dörr Oliver , Nef Holger M.
Published: June 2020

Die Angina pectoris steht bei Patienten mit einem chronischen Koronarsyndrom im Mittelpunkt der Beschwerden und kann mithilfe der perkutanen Koronarintervention bei Vorliegen einer hämodynamisch relevanten Stenose behandelt werden. Eine Verbesserung der Prognose konnte bislang in vielen Studien nicht nachgewiesen werden, was unter anderem durch prozedurassoziierte Ereignisse verursacht ist, die bei einer alleinigen medikamentösen Therapie nicht auftreten. Dementsprechend muss es das Ziel der koronaren Interventionstherapie sein, sich stetig an die immer herausfordernderen klinischen Situationen anzupassen und entsprechende Strategien zu verbessern. Hierzu dient vor allem die intravaskuläre Bildgebung, durch die bei komplexen Läsionen ein individueller Therapieansatz entwickelt werden kann und die den differenzierten Einsatz läsionsvorbereitender Maßnahmen zulässt. Neben verbesserten Stentdevices können auch spezifische Stentstrategien, z. B. in Bifurkationen, klinische Ereignisse nach einer Intervention weiter reduzieren. Begleitend ist die nachfolgende medikamentöse Therapie, insbesondere die duale Plättchenhemmung, zu beachten, die je nach ischämischem bzw. Blutungsrisiko individuell festgelegt werden muss.
Harnblasenkarzinom
Authors: Schmale Ine
Published: June 2020

Auf dem Genitourinary Cancers Symposium (ASCO GU) in San Francisco wurden für Patienten mit Harnblasenkarzinom mehrere Studien zur Optimierung der neoadjuvanten Therapie und der intravesikalen Instillation präsentiert.