bluuebunny/crossref_metadata_2025_split huggingface dataset:
Future energy pathways for a university campus considering possibilities for energy efficiency improvements
Authors: Nord Natasa , Sandberg Nina Holck , Ngo Huy , Nesgård Eirik , Woszczek Aleksandra , Tereshchenko Tymofii , Næss Jan Sandstad , Brattebø Helge 
Published: October 2019

Abstract
The study aimed to show in a systematic way possible energy efficiency measures that would decrease the total energy use at the university campus in Trondheim, Norway. The entire study was developed in close collaboration with the NTNU Property and Technical Management divisions, meaning that suggested energy efficiency scenarios and other assumptions were highly relevant. Currently, the campus floor area is about 300 000 m2 and consists of buildings combining offices, lecturing halls, study halls, and laboratories. The campus building stock has been built from 1910 to 2002. To perform this study, building performance simulation and the dynamic segmented modeling were combined. A dynamic neighborhood building stock model was utilized to aggregate the outputs from the building simulation and evaluate global effects of energy efficiency measures. Reference building models for each university cohort were developed based on the methodology for defining the reference buildings. The results of the single reference building analyses showed that a decrease of up to 50% in heating energy use might be achieved by increasing efficiency of the ventilation system and by decreasing the temperature of the heating system. The results showed that in spite of building stock growth, the estimated energy use would decrease from 2017 to 2050 by 10% for the standard renovation, and by 26% for the combination of ambitious renovation and technical improvements.
OmrådeLCA, assessment of area development: Case study of the Zero-Emission Neighbourhood Ydalir
Authors: Yttersian V L , Fuglseth M , Lausselet C , Brattebø H 
Published: October 2019

Abstract
The built environment is a major contributor to global greenhouse gas (GHG) emissions. There is a growing need to quantifying GHG emissions, and LCA tools can be used to help address them and find the key contributors. In order to compare different solutions of development of the built environment in the early stage planning process, the OmrådeLCA tool has been developed. OmrådeLCA has the unique advantage, compared to other similar tools, of using the system expansion approach, which allows for comparing different scenarios based on the same functional unit. We applied OmrådeLCA on Ydalir (Norway), a zero emission neighbourhood in an early stage planning process. The results show how significant the share of emissions from transportation are, contributing to more than 60 % to the total GHG emissions. Sensitivity analysis shows that choices made, and data used in modelling transportation significantly impact resulting GHG emissions. Thus, conducting a thorough analysis of factors affecting transportation is important for obtaining representative results when using OmrådeLCA. The results from the assessment of Ydalir with OmrådeLCA have been compared with results from the same case assessed with a tool developed by NTNU. The comparison shows relatively small differences in calculated results. This small degree of variation between the two tools in calculated results, demonstrates that OmrådeLCA can provide good estimates even at an early stage. This gives the tool great utility value because it is in the early stages of a project major actions can be performed and decisions made that will affect the emissions the most.
Review of HVAC strategies for energy renovation of detached houses towards nZEB in cold climates
Authors: Heide V , Georges L , Lien A G , Mathisen H M 
Published: October 2019

Abstract
This paper provides a review of heat and ventilation measures that can be applied to ambitious energy renovation of detached houses in Nordic countries. In this review, requirements for solutions are defined. Key technologies are described and analysed in the context of renovation. The review focuses on strategies that are simple, cost-effective and robust, and can be transposed to the Norwegian context. The review revealed that a wider range of concepts and strategies than commonly used in Norway seem to be relevant. No solution or system appears to be an obvious and universal choice. A number of very different system solutions, with their pros and cons, are relevant, depending on the individual house and situation. Some combined heat and ventilation systems include hydronic space heating. This is however not common in Norwegian houses, and installing this is a major cost and intervention. Wood stoves, on the other hand, are regular, and can be used for peak heating. These factors seem to be crucial for the choice of system. Improved airtightness after renovation makes systematic ventilation measures necessary. Assumptions for occupant preferences and behaviour also seem to be important for choice of system. There are also differences in the commonly used HVAC concepts and strategies for renovation between the Nordic countries. These differences do not seem to be explained by climate only, and differences in building code may be part of the reason. A number of demonstration projects on ambitious energy upgrading are completed, but few of them have been systematically monitored and evaluated.
Assessing cities: Applying GIS-based methods for mapping cross-scale spatial indicators
Authors: Rokseth L S , Manum B , Nordström T 
Published: October 2019

Abstract
In recent years, several systems and tools to assess energy consumption and carbon emissions at scales beyond that of merely buildings, such as LEED, CASBEE and BREEAM communities have been development. However, reviews reveal a lack of robustness in these methods both in terms of an unstructured mix of qualitative and quantitative criteria and lack of focus on urban form parameters found to influence energy consumption and carbon emissions. A promising quantitative assessment system including various urban form indicators is developed by the Urban Morphology Institute (UMI) in Paris. Within the research centre on zero emission neighbourhoods in smart cities (ZEN), a GIS-based method is applied to analyze conditions of urban form known to contribute to carbon emissions. In this paper we demonstrate how a selection of the UMI indicators describing proximity can be further specified applying GIS-based methods. The potential of applicability of urban assessment system in planning as well as design processes will increase when linked to tools that are already implemented, and map visualizations as well as data provided by these methods are highly applicable in planning and urban design. As further research, methods described in recent research within ZEN and specified measures for calculating UMI indicators, will be tested in analyses of urban development areas in Norway.
Energy efficiency of strategies to enable temperature zoning during winter in highly-insulated residential buildings equipped with balanced mechanical ventilation
Authors: Georges L. , Selvnes E. , Heide V. , Mathisen H.M. 
Published: October 2019

Abstract
To reduce the space-heating needs, balanced mechanical ventilation equipped with a heat recovery is frequently implemented in highly-insulated residential buildings. This standard ventilation strategy tends to homogenize temperature inside the building, in other words, to reduce temperature zoning. In some countries, such as Norway, many users would like colder bedrooms. It has been proved that a significant part of the occupants in Norwegian passive houses opens bedroom windows during several hours every night during winter. Dynamic simulations have shown that it strongly increases the space-heating needs and that control only is unable to create temperature zoning in an energy-efficient way. The building concept should be changed. In the present contribution, the physical processes during temperature zoning are further explained. Detailed dynamic simulations of a detached single-family house are performed using the simulation software IDA ICE for different insulation levels, construction modes (which also influence the thermal insulation in partition walls) and control strategies. Alternative mechanical ventilation strategies are compared. They manage to reduce the influence of mechanical ventilation on the increased space-heating needs due to window opening but they cannot improve the large contribution of heat conduction through partition walls between heated areas and unheated bedrooms. Among the investigated ventilation strategies, decentralized ventilation has intrinsically the best performance.
Overheating and daylighting evaluation for free-running classroom designs
Authors: Kiil M , Simson R , de Luca F , Thalfeldt M , Kurnitski J 
Published: October 2019

Abstract
Learning performance is strongly related to thermal comfort and lighting conditions of classrooms. Poor facade design can result in high indoor temperatures or insufficient access to natural light. To maintain the required temperatures and illuminance levels in such rooms may require intensive use of artificial lighting and active cooling systems, which are energy-intensive, costly to install, operate and maintain. The purpose of this study was to determine essential parameters and facade design options that ensure overheating prevention and fulfil daylight requirements in classrooms without mechanical cooling. The present study is based on simulations of a parametric room model with variable dimensions and orientations. Facade glazing solutions with optimal combination of solar factor and visible light transmittance were used to minimize overheating risk and maximize natural lighting impact. For east, south and west oriented facades, the effect of horizontal shading was also analysed. Overheating assessment through indoor temperature simulations was conducted with dynamic simulation software IDA ICE, daylighting was simulated with DIVA4 coupled with Grasshopper software. Results show that classrooms without mechanical cooling require in depth analysis to determine satisfying solutions for both overheating and daylighting criteria. The results of this paper can be used for early stage facade design guide for school buildings or similar use free-running buildings.
Study of Voltage Stability Due to Shading Effects on Photovoltaic Penetration in PKMT Distribution System
Authors: Nabila N , Bangun G M , Budiansyah M A , Alvianingsih G , Utomo A R 
Published: October 2019

Abstract
PV output power is firmly influenced by temperature and solar irradiation that fall on the surface of the PV modules. Shading which cross-wising the surface of PV modules is major factor that prevails the degradation of its performance. The shading in PV arrays is caused by the presence of cloud, dust, fog, trees, the shadow near buildings, and so on. As the result of the shading effect, the voltage and current outputs fluctuate which would in turn reducing the efficiency of the PV output. The voltage and current of PV solar cells will drop from partial shading effect experiment which consists of 20%, 40%, 60%, 80%, and 100% shading area. This paper shows the effect of PV system over the voltage stability by variating the shading conditions using simulation by ETAP software 12.6.0.
Characteristics of disturbance in frequency 9 -150 kHz of Rasuna Said gas station’s solar panel system
Authors: Hood M L , Sudiarto B 
Published: October 2019

Abstract
Dependence on the usage of fossil fuel energy sources as a source of electrical energy to overcome the increase in electrical energy needs. The high demand for electricity encourages the development of the use of non-fossil energy sources. One of the new and renewable energy sources producing electricity is solar energy from the sun. Solar panels produce DC electricity which can be converted into AC electricity using an inverter so that it can be connected to an AC load. The switching process and the use of power electronic components in the inverter can generate electrical wave distortion such as disturbance with 9 – 150 kHz frequency in the solar panel system. In this study, the characteristics of the disturbance frequency 9-150 kHz reviewed and their effects on solar irradiation. Furthermore, it shows that the solar panels system-generated disturbance and increased by 1.5 – 12.6% per 100 W/m2
An Improved P&O Algorithm for Single-Stage Grid-Connected Photovoltaic System under Rapidly Changing Environment Conditions
Authors: Kusuma A A B , Hakim M D E , Alvianingsih G , Aryani D R , Utomo A R 
Published: October 2019

Abstract
In producing its power, Photovoltaic (PV) performance is influenced by environmental factors, such as solar irradiance and temperature. System stability is needed to maintain safe operation of the system. This paper presents a Maximum Power Point Tracking (MPPT) control model of PV array to improve system reliability and the performance of MPPT. The main parameters in Matlab/Simulink simulation that become the highlight influences are the changes in solar irradiance from 500W/m2 to 1000W/m2 and ambient temperatures from 25°C to 50°C. With the control algorithm that has been made in the Perturb and Observe (P&O) method, it obtains the optimal voltage control point in each PV conditions in a power system. System simulation shows that the voltage stability was maintained above 510 Volt in various conditions of solar irradiance and temperature. The results of the control scheme show the stability of the system and the optimal performance of PV.
Purification of silica from tin tailings through solid-state method
Authors: Evi J , Tiandho Y , Rafsanjani R A , Afriani F 
Published: October 2019

Abstract
Indonesia is one of the largest tin producers in the world. The by-products of processing tin ore in the form of tailings are not used properly. Based on several studies, tin tailings have high levels of silica. In this paper, a silica purification study from tin tailings is proposed using a solid-state method at different pH. The purity of silica in this paper is determined by XRF and XRD analysis. This research is expected to increase the economic value of tin tailings, which can be utilized in various applications.
Factors Affecting the Production of Biosurfactants and their Applications in Enhanced Oil Recovery (EOR). A Review
Authors: Sari C N , Hertadi R , Gozan M , Roslan A M 
Published: October 2019

Abstract
Biosurfactants are surface-active compounds synthesized by microbes. They have the ability to reduce the surface tension of a liquid and interfacial tension (IFT) between two different phases. Thus, they can be applied in water-oil emulsification. The development of enhanced oil recovery (EOR) technology has led to increased interest in biosurfactants. The purpose of this review was to compile information on important components of biosurfactant production. Understanding the characteristics of biosurfactants, especially IFT derivation and effects of alterations in the wettability of reservoir rocks can aid the applications in EOR. Both the microbe type and growth substrate influence the yield and type of biosurfactant produced. The type of fermenter also affects the efficiency of surfactant production. The use of batch type fermentors and the use of Pseudomonas and Bacillus bacteria in the previous research was superior whereas the sugar group and plant base oil as substrates. The measurement methods of biosurfactants in microbial culture are of considerable importance to be done prior to characterization of biosurfactant products. Furthermore, some reservoir components discussed in this review are the keys to the success of biosurfactant flooding in the field.
An Efforts to Maintain the Sustainability of Renewable Energy System in Rural Area through Green School Education Model
Authors: Novitasari D , Hidayat S , Puruhito D D , Arruzi R K , Aliyah F , Mahfud A 
Published: October 2019

Abstract
Indonesia has hundreds of renewable energy systems as a source of electrical energy that is spread in rural area. This is done as a government effort to provide electricity access for people who do not have access to electricity from the National Electric Company. The technology built in the village managed by the community. Community preparation in technical and non-technical is needed, thus the renewable energy system can provide electricity for a long time. The Green School is a place for the community to learn from each other and discuss about the renewable energy system in their village. The Green School is designed to have three curricula consisting of Basic Training, Intermediate Training and Advanced Training. The training should consist of participants from various background, education and also notice on gender perspective. Basic training’s main goal is making participants braver to express their opinions in front of the forum. The material is about their daily problem. Intermediate Training’s goal is increasing capacity building of community on managing renewable energy technology, e.g. how to handle the problem. Advanced Training’s goal is networking with outside parties to get more ideas and experiences thus community ready to collaborate in managing technology.
The Study of Morfometric and Meristic of Yellow Tail Fish Landed in Nusantara Fishery Harbour of Sungailiat, Bangka Regency
Authors: Gustomi A , Arizona M O , Akhrianti I 
Published: October 2019

Abstract
Caesionidae is one of the first commodity from a kind of varieties fishes in Nusantara Fishery Harbour (PPN) at Sungailiat, Bangka Regency. Caesionidae is consumption fish and become important food source for human. People call this fish as Yellow tail fish because it has yellow tail and the upper body of this fish is dominate by yellow colour. In scientific name, this fish named as caesiocuning. On local name, yellow tail fish named “delah”.This research aims to analyze the charachter of morphometric and meristic of yellow tail fish in PPN Sungailiat, Bangka Regency on December 2018 to januari 2019. The data was taken using random sampling method. This research takes 23 morfometric and 9 meristicparameters.The character of morphometric showed that the yellow fish tail has Total Length body 12-18,3cm. The characters of meristic of Yellow tail fusilier in PPN Sungailiat Bangka Regency showed has the formula of Dorsal Rays, Anal Rays, Pectoral Rays, Ventral Rays, and Caudal Rays in order are D.IX 15- D.X 15, A.III 9- A.III 11, P.18, V.19-V.20, and C.18-C.22. The final result of classification showsthat the name fish in PPN Sungailiat (Bangka Regency),is Lutjanus vitta (Lutjanidae).
Response statistics of single degree of nonlinear random structure with nonlinear damping characteristic and nonlinear elastic characteristic under white-noise excitations
Authors: Stan P , Stan M 
Published: October 2019

Abstract
The paper investigates the applicability of the path integral solution method for calculating the response statistics of nonlinear dynamic systems whose equations of motion can be modelled by the use linearization differential equations. The present paper consists of discussion on dynamic response of structures under random load. They are random processes and commonly described by spectral density functions. An identification technique is proposed for a nonlinear oscillator excited by response-dependent white noise. Stiffness, damping and excitation are estimated from records of the stationary stochastic response. Assume that a single-degree of freedom structure is excited by a force which is a random process described by the spectral density function.
Automotive rubber part design using machine learning
Authors: Huri D , Mankovits T 
Published: October 2019

Abstract
In rubber products design finite element analysis is a widely used technique. In many cases, the pre-defined operating conditions can be achieved by changing the geometric dimensions of the product which is the well-known iterative design method. Using more than one design parameter the number of possible combinations will increase significantly. The application of Support Vector Machine (SVM) can handle the large number of data in a special way and helps to find the optimal design parameters. In this paper an optimization process of a rubber jounce is presented using nonlinear finite element analysis and SVM.
CAD modeling of the closing HIGH TIBIAL OSTEOTHOMY
Authors: Cofaru N F , Cofaru I I , Marjanović V , Marjanović N , Blagojević M , Petruse R E 
Published: October 2019

Abstract
The article proposes a generalised CAD modeling for a surgical strategy applied to the axial deviations of the human leg. These deviations appear most of the cases from a most common disease nowadays, ghonartrosys characterised by usage of the knee’s articular cartilage. The surgical strategy is HIGH TIBIAL OSTEOTOMY and it is very appropriate in order to correct the axial deviation due several reasons such as: repair with good results the axial deviations, good rate price/quality, strongly recommended method for young patients, not needed a maintenance activity as in case of the prosthesis. In the article it starts with the presentation of the mechanical axis of the lower limb and of the axial deviations that might appear and then using the CAD type modeling tools it is simulated and modelled the surgical procedure: Closing High tibial osteotomy. The approach is very important both from didactically consideration and possible evaluations presurgical, intrasurgical and postsurgical.
Welding method as influential factor of mechanical properties at high-strength low-alloyed steels
Authors: Ilic A , Ivanović L , Lazić V , Josifović D 
Published: October 2019

Abstract
In this paper the analysis of welding technology to mechanical properties of welded joints at high strength low alloyed steel S690QL is presented. Experimental testing was done at models with V-groove butt joints that are done by MMA or MIG for root pass and MAG for other passes of multipass welded joints with related parameters and consumables. Yield and tensile strength, so as answer to load of models are determined experimentally in order to analyses the effect of welding technology to resulted mechanical properties. On the basis of the obtained results it can be concluded that welding parameters have significant influence to mechanical properties of welded joints at high-strength low-alloyed steel. Furthermore, it can be concluded that welded joints with root pass done by MIG and other passes by MAG provide better mechanical properties. Presented research point out that welding parameters at high strength low alloyed steels must be selected and controlled precisely to obtain welding joints with adequate mechanical properties. Welding, as dominant method of joining, is primary factor that provide beneficial application of high-strength low-alloyed steels. The paper highlight the influence of material degradation due to welding. This paper point out the importance of analysing the welded joints at different levels of dimensions, while further, more detailed, research can be continued through development of a numerical model of the welded joints which will complete the experimentally obtained results. As experimentally obtained results correlate to material degradation due to welding it is implicated that future development of high-strength low-alloyed steels must be followed with development and modification of welding processes.
Quality control of closed-cell metal foam produced by direct foaming
Authors: Gábora A , Mankovits T 
Published: October 2019

Abstract
Metal foams have a lightweight cellular structure with excellent mechanical and physical properties. Although metal foams are popular, they are still not sufficiently characterized thanks to their extremely complex structure which is highly stochastic in nature. In this paper the influence of the technological parameters on the structure is analyzed. In laboratorial circumstances the production of closed cell aluminum foams depends on several factor. The purpose of the paper is to analyze the human factor on the quality of the metal foam specimens.