bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of small non-sphericity of converging shock waves in bubbles during collapse in acetone and tetradecane
Authors: Yu Toporkov D 
Published: October 2019

Abstract
A strong compression of vapor in cavitation bubbles during their collapse in acetone and tetradecane at a temperature of 293 K and 663 K, respectively, is considered. At the beginning of collapse, the bubbles are at rest, their radius is 500 μm, the vapor in the bubbles is in a state of saturation at a temperature of the surrounding liquid. The pressures of tetradecane and acetone are 50 and 15 bar, respectively. At these pressures, the degrees of strong vapor compression in the cavitaion bubbles in tetradecane and acetone are fairly close to one another. An approximate estimate of maximum perturbations of the shock wave sphericity is made. It is shown that at the moment of focusing, the converging shock wave inside the bubble in acetone turns out to be more spherical despite the fact that at the end of collapse, the non-sphericity of the bubble in acetone is much greater.
Dynamics of acoustic waves in a liquid with solid particles and gas bubbles
Authors: Gubaidullin D A , Gubaidullina D D , Fedorov Yu V 
Published: October 2019

Abstract
A mathematical model that determines the propagation of acoustic waves in a mixture of a liquid with gas bubbles and solid particles is presented. The system of differential equations is written, the dispersion equation is obtained. Low-frequency and high-frequency asymptotics of the sound speed in the specified mixture are found and illustrated. The influence of solid particles and gas bubbles on the dispersion and dissipation of acoustic waves is indicated. For a mixture of liquid and solid particles, a comparison of the speed of sound with known experimental data is presented.
Synchronous Boost DC-DC Converter for Nitrogen Plasma
Authors: Hakki A , Kashapov N , Fedorenko M 
Published: October 2019

Abstract
The paper describes a high power synchronous boost inverter for Nitrogen plasma torches. A high frequency was used in order to drive the pulse width modulation circuit. The average output current consumption (AOCC) was modified from (15A) up to (25A). The (AOCC) was reduced from (25A) down to (15A) by increasing the duty ratio from (0.75) up to (0.88). The switching frequency of the sync boost inverter was fixed at (20KHz).
Some characteristics of surface hardening of steel 65g in the electric-spark method
Authors: Sharifullin S N , Fayzrakhmanov I A , Adigamov N R , Akhmetzyanov R R , Shaykhutdinov R R , Lyadov R M , Shustov V A , Bayniyazova A T 
Published: October 2019

Abstract
The paper presents the results of studies of some physical and mechanical properties of metal samples made of 65G steel, hardened by electrospark method. Researches are connected with the solution of problems of increase of a resource of work of details and working bodies of agricultural machines. The elemental composition, phase composition and microstructure of the surface of 65G steel samples processed by the electrospark method were investigated.
Experimental study of the energy characteristics of a longitudinal Glow Discharge
Authors: Yunusov R F , Garipov M M 
Published: October 2019

Abstract
Currently, a glow discharge is widely used not only as a gas-discharge light source or as an active medium for gas lasers, but also as an element of a plasma-chemical reactor, which allows for various chemical transformations in order to obtain new materials, modify and clean surfaces. Despite the fact that the structure and distribution of parameters in a classical glow discharge without gas flow and flat cylindrical electrodes are well known, to solve new technological problems, it is necessary to study glow discharge in discharge chambers with different electrode geometries and gas flow organization methods.The presence of a gas flow causes heterogeneity in the distribution of the parameters of a glow discharge, and can also affect the structure of its individual zones. Experimental study of the parameters of a longitudinal glow discharge will allow not only a better understanding of the physics of gas discharge, but also will make it possible to find ways to control these parameters, which is important for designing discharge chambers of various technological purposes. The article is devoted to a comprehensive experimental study of the distribution of potentials, field strength, current-voltage characteristics in a longitudinal glow discharge. The gas pressure P, its flow rate G, the discharge current strength I and its voltage U vary respectively in the ranges: P = (2–9) kPa, G = (0–0. 05) g / s, I = (30-80) mA, U = (1 - 2) kV.
Data Management System for Photovoltaic Solar Environment
Authors: Tak H , Lee D , Kim H , Cho H G 
Published: October 2019

Abstract
As communication environments and Internet-of-Things technologies evolve, smart grid is being studied for collecting and predicting facility data in real time. In this paper, we propose a management system that collects the data of a photovoltaic system and predicts the amount of power generation. For this purpose, we designed an environment that can collect solar data, adjacent environment data, and facility information in real time. In addition, to expand the limits of previous power generation prediction studies, a power generation prediction experiment was conducted using recurrent neural network-based methods. The experimental results are compared with those of previous studies.
Coordinated Scheduling of District Integrated Energy System for Enhancing Resilience in Extreme Events
Authors: Qi S X , Wang X L , Peng Q , Zhu C Z 
Published: October 2019

Abstract
In this paper, a coordinated scheduling model is proposed, which provides resilience enhancement for the district integrated energy system (DIES) against extreme events. The innovation of this model is to divide scheduling into three stages. In the normal scheduling, the objective is to minimize the operation costs until a disaster alert occurs. In the proactive scheduling, the objective is to maximize the stored energy for supplying post-disaster load demand. In the resilient scheduling, the objective is to minimize the amount of load shedding. Moreover, the time of disaster alert, disaster disruption and system recovery are uncertain. Hence, according to the intensity of disasters, the results of the proposed coordinated scheduling are analysed by three disaster scenarios. The scheduling is established by optimizing the model, which is transformed into a mixed integer linear programming. Finally, it is verified that the coordinated scheduling model proposed can effectively enhance resilience of DIES by case studies.
Users’ satisfaction of indoor environmental quality conditions in ZEB+ at high latitudes
Authors: Zaikina Veronika , Moscoso Claudia , Matusiak Barbara , Chelli Ali , Balasingham Ilangko 
Published: October 2019

AbstractEnergy efficiency policy forces architects to design buildings with increasingly well-sealed building skin. With the minimized outdoor connection, the indoor environment factors depend strongly on technical systems and control. In these scenarios, occupant dissatisfaction indicates a need for improvements of indoor environment and the way it is controlled. The aim of the article is to contribute to the discussion about the user perspective of indoor environmental quality in ZEB in the Nordic region. The focus on daylight as a factor for visual comfort, and on low outside temperature as an aspect of thermal comfort was dictated by this choice. An experimental study was conducted with 75 participants, in which the thermal, acoustic and visual conditions (controlled factors) together with a view out, humidity and CO2 level (monitored factors) were assessed by them and quantified via sensors. In most studied settings, the thermal comfort was the most determinant factor, followed by the acoustic and visual comfort. Other significant factors were mean illuminance in the room, mean temperature at the participants’ desks and a mode value of the noise level. The daylight levels much lower than recommended in regulations were accepted by participants as comfortable if they were sitting by the window. Also, participants preferred a higher indoor temperature than the recommended in Norway.
User engagement with smart home technology for enabling building energy flexibility in a district heating system
Authors: Larsen Simon Peter , Johra Hicham 
Published: October 2019

Abstract
The future low-carbon emission societies rely on energy systems bearing an increasing share of renewable energy sources (RES). Consequently, demand-side management and energy flexibility become a key solution to compensate for the intermittent nature of RES. District heating systems hold a large potential for energy flexibility if households are actively integrated. While previous research and local policies have applied demand-side management such as smart meters, new smart home technology envisions full employment of the flexibility potential of the building stock. Morning energy demand peak is a major concern for district heating systems in Nordic countries. Demand-side management for district heating has thus mainly focused on morning hours peak-shaving. While integrating smart home technology as a demand-side management solution, the household becomes a flexible energy hub for thermal energy storage. While the technical potential of achieving such flexibility has been investigated, less research has been carried out concerning how users engage with smart home technology and how this influences the possibilities for load-shifting of the indoor space-heating demand. By conducting qualitative studies (interviews and ‘show and tell’ home tours) in 16 Danish households, this paper explores how users engage with smart home technology and how this influences the possibilities for load-shifting in a district heating system. The study provides insight into how the occupants interact with different smart technologies providing space-heating control. Results show that engagement with smart home technology must be understood as part of people’s everyday practices. The flexibility in energy demand must be generated by understanding and changing practices to make them more flexible during peak hours. While smart home technology holds the potential for adding flexibility within the district heating system, the technology is rarely used as intended by occupants. Smart home technology is disrupting, and users rapidly create workarounds in order to perform everyday practices. Load-shifting during morning hours is thus a technical possibility, but the dominant techno-economic paradigm embedded in smart home technologies remains a barrier, as the latter must adapt to the everyday practices.
Living labs in a zero emission neighbourhood context
Authors: Woods R , Berker T 
Published: October 2019

Abstract
The Research Centre for Zero Emission Neighbourhoods in Smart cities has established a concept for living labs. Central to the concept is an experimental format that offers some control over the social and physical environment, as well as opportunities to observe and engage during a limited period. According to Bulkeley et al. 2018, an experiment offers a means to make sense of the present whilst also providing a vision of the future [1]. The paper asks, what are the implications for users when engaging with experiments and presents results from a ZEN living lab experiment that took place at Campus Evenstad in Hedmark, Norway.
Technical management at Evenstad proposed the experiment, they wanted to test if it was possible to reduce campus energy consumption and the starting point was the old administration building, which has the highest energy consumption on campus. The energy use reduction was to be achieved by turning off the building’s heating and ventilation systems during a limited four-week period. This took place in July 2018, when the building users were expected to be on holiday or doing fieldwork. A workshop to anchor the experiment among building users took place a month before the experiment started. During the workshop challenges associated with the experiment and with the building, for users, became apparent. However, building users agreed to participation in the experiment because they saw it as an opportunity to highlight what they understood as necessary changes to the building. The experiment achieved the energy saving potential that the building managers envisioned, but the results for the building users are less tangible.
From a pragmatist approach, living labs and their experiments are about providing solutions, but the Evenstad example highlights the challenge of providing tangible solutions and how we engage users with more intangible future solutions. We discuss therefore the limitations and potentials associated with the experimental format. Moving beyond demonstrating what a sustainable future should look like and include [1p.1], and instead noting opportunities for the translation of societal learning into concrete actions that serve the user groups engaged as well as demonstrating, the potential to influence wider sustainable transitions.
Refurbishment of historic buildings at a district scale: Enhancement of cultural value and emissions reduction potential
Authors: Loli A , Bertolin C , Kleiven T 
Published: October 2019

Abstract
The historic buildings have a significant value in providing a sense of identity to the cities and the community. On the other hand, due to their age, they show the highest ratio of living discomfort and energy consumption. Therefore, their refurbishment is a very important process because, if done right, it will not only reduce their energy demand and increase the living comfort but will also strengthen the social and cultural benefits through leisure and tourism.
In the city of Trondheim, as in many other European cities, the historic buildings have been erected in different architectural periods, which manifest diverse historic and technical features. A categorisation of the wall sections of historic buildings has been done for each city’s development period regarding their construction material and technique, building functionality and protection status.
The scope of the article is to estimate the potential for reduction of greenhouse gas emissions at a street/neighbourhood/city level prior to applying large-scale intervention measures. This can be achieved by proposing refurbishment alternatives for wall and window sections that preserve the historic value and at the same time, approach or even meet the actual technical standards. Afterwards, the carbon footprint of the refurbishment action itself and the environmental benefits after the refurbishment (operational phase) is estimated for each category of wall sections. The environmental results, multiplied with the total surface of sections carrying the same attributes, give the overall potential of reduction for the entire group of buildings. Based on this, the on-site renewable energy that would lead to achieving zero-emission targets can be calculated. The framework is also important because it does not treat each building separately, but it suggests refurbishment scenarios for specific categories of buildings built in different historical periods.
A parametric study of the energy performance and carbon footprint of super-insulation in terrace constructions
Authors: Skaar Christofer , Gaarder Jørn Emil , Sletnes Malin 
Published: October 2019

Abstract
Energy requirements for buildings are continually tightened, as seen in the ambitions to introduce near zero-energy building (nZEB) requirements in Norwegian and European building codes from 2020. One consequence of this is an increased use of insulation. However, standard insulation may cause challenges in many circumstances, for example where increased wall dimensions lead to reduced daylight levels or where increased insulation leads to increased floor height. Super-insulation materials are a possible solution to these challenges. Although several super-insulation products exist on the market, there is still a need for proven system solutions that provide the required level of insulation, along with reduced thickness in the constructions. An additional challenge is that these solutions should also be cost-effective and carbon-effective. The economic benefits should outweigh the costs and the carbon footprint should ideally be reduced, but at least not significantly increased.
To analyse the potential of super-insulation, we have performed a parametric case study of terrace constructions based on super-insulation and compared these with a baseline solution. The terrace construction uses vacuum insulation panels (VIP) as the main insulation. The top plate insulation is tapered mineral wool, aerogel is used in the edges and on top of the construction there are wood tiles. The parameters that have been varied are i) terrace dimensions, ii) width of the edge with non-combustible aerogel, iii) the thickness of the VIP layer, iii) the slope of the tapering, and iv) the heat conductivity of the VIP panels.
To evaluate the benefits of the super-insulation an analysis of energy performance in the use phase has been done. As the energy efficiency of the super-insulation solution is improved, this gain can be used either to reduce thickness or to increase energy performance. Both these will have an impact on the costs. To evaluate the environmental performance of the solution a screening LCA has been performed, with focus on the carbon footprint. The results of the case study show under which circumstances the super-insulation solution has better performance than the baseline, and vice versa. Key parameters that drive energy performance and carbon footprint are identified, providing suggestions for further research.
Influence of emerging technologies deployment in residential built stock on electric energy cost and grid load
Authors: Zhuravchak Ruslan , Nord Natasa , Brattebø Helge 
Published: October 2019

Abstract
High penetration rates of novel building energy technologies has prompted a growing concern about their microeconomic effect and grid influence. Deployment of photovoltaic (PV), solar water heating (SWH) systems and energy storage solutions, in addition to the growth of electric vehicles (EV) fleet, are reshaping the structure of built stock and lead to the changes in its electric energy demand profile. Long-term forecasting of such structural changes is necessary to guide the decision-making process that would satisfy the needs of both, energy consumers and the suppliers. Whereas electric energy price model is one of the key influencing factors of technologies acceptance for households, peak loads and grid feed-in determine the needed capacity of power grids. The objective of this study was to assess both, the aggregated cost of energy and the changes in cumulative load profiles that are excepted by 2050 for one of residential building typologies in Norway. Methodologically, it was achieved with descriptive statistics, stochastic forecasting and detailed energy performance simulation. Annual electric energy cost for consumers were evaluated under six pricing models. The results suggested that time-of-use and variable maximum power extraction models represent the lowest and the highest extremes in energy cost. At the aggregated level, peak load will decrease in range 1% to 13% compared to current level. Peak PV feed-in will reach up to 40% of peak load by 2050.
Exploring the tools and methods to evaluate influence of social groups on individual occupant behavior with impact on energy use
Authors: Annaqeeb M K , Dziedzic J W , Yan D , Novakovic V 
Published: October 2019

Abstract
One of the key elements in driving the energy performance of buildings has been recognized as occupant behavior (OB). However, available tools for assessing and simulating occupant behavior are based on fixed schedules and aggregated profiles, which fail to capture the diversity of OB. A significant aspect of OB is its relation to social groups and their influence and interdependence on each other. The data regarding the influence of social groups is important to achieve an effective model of OB as it accentuates the individual OB profile based on the influences it can have from the social groups they belong to. This added module is not present in traditional building simulation tools. This study aims to explore the tools and methods to evaluate the factors that are responsible for the influence of social groups on individuals’ energy-related behavior. The paper investigates the kind of data sets needed for understanding this interdependence, including the occupant’s social group, their standing in the group, and the intent behind different actions and its comparison to the actions the individual would take without any external influence. The results will be used to construct questionnaires, which can prove beneficial in developing social group profiles in OB models.
Energy Flexibility for an Institutional Building with Integrated Solar System: Case Study Analysis
Authors: Amara Fatima , Dermardiros Vasken , Athienitis Andreas K. 
Published: October 2019

Abstract
Buildings with renewable energy systems and sizeable energy storage capacity can provide significant energy flexibility. Defining appropriate load management strategies requires estimating this flexibility accurately. However, this is no easy task, since the energy flexibility depends on the building structure, heating/cooling system, meteorological conditions, occupant activities, demand response strategy, among other factors. This paper focuses on the thermal storage flexibility of a building component: a concrete floor with an embedded radiant hydronic system. An approach based on a combined adaptive Auto Regressive model with exogenous inputs (ARX) is used to quantify the thermal energy available in the concrete slab. The model describes the relationship between: (a) the geothermal pump system and weather variables and (b) the temperatures of the indoor air and the concrete surface slab. These temperatures are then used to assess the state of charge (SOC) of the slab. The SOC indicator is critical to reducing heating energy use during peak periods. Results show that the proposed model can accurately quantify the energy flexibility of the building through performance indicators. Finally, tests using real data confirm the validity of the model as a tool to estimate energy flexibility.