bluuebunny/crossref_metadata_2025 huggingface dataset:
Nitro compounds as the core structures of promising energetic materials and versatile reagents for organic synthesis
Authors: Zlotin Sergei G. , Dalinger Igor L. , Makhova Nina N. , Tartakovsky Vladimir A.
Published: October 2019

This review addresses some promising areas of chemistry of nitro compounds extensively developed in recent years in Russia (particularly at the N.D.Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences) and worldwide. The most important results in the synthesis of novel energetic N-, C- and O-nitro compounds are summarized. New environmentally friendly approaches to the preparation of known compounds of this series, used as components of energetic compositions, are considered. Methods for selective transformations of various nitro compounds to valuable products of organic synthesis, primarily biologically active products and their precursors, are systematically analyzed.

The bibliography includes 446 references.
Synthesis and Structures of Bis- and Tris-(triphenylarsine)gold(I) Iodides
Authors: Bowmaker Graham A. , Healy Peter C. , Sobolev Alexandre N. , White Allan H.
Published: October 2019

The title compounds [(Ph3As)2AuI] and [(Ph3As)3AuI] have been crystallized from equimolar solutions of Bu4NAuI2 and AsPh3 in dimethylformamide and structurally characterized by single crystal X-ray diffraction studies. [(Ph3As)2AuI] crystallizes in space group C2/c, Z 4, and is isomorphous with other [(Ph3E)2MX] (MX=coinage metal(i) salt) arrays, with the Au–I bond being disposed on a crystallographic 2-axis: Au–I, As 2.7008(2), 2.4337(2) Å, As–Au–As, I 125.736(8)°, 117.132(4)° (153K). [(Ph3As)3AuI] crystallizes as a triclinic phase in space group , Z 4, and is isomorphous with [(Ph3Sb)3CuI] and [(Ph3P)3AgI]: Au–As 2.4847–2.5049(10), Au–I 2.8518(8), 2.8597(7) Å with As–Au–As, I 109.67(3)–115.97(3)°, 101.33(2)–106.85(3)°. A second ‘[(Ph3As)3AuI]’ product was obtained as a co-crystalline phase in space group P21/n containing [(Ph3As)3AuI], and [(Ph3As)2AuI] accompanied by an additional unbound Ph3As molecule, i.e. [(Ph3As)3AuI]·[(Ph3As)2AuI·Ph3As], with structural parameters closely similar to those for the corresponding separate [(Ph3As)3AuI] and [(Ph3As)2AuI] complexes described above. Comparison of the bond lengths for these and related complexes show that they are generally consistent with the ‘gold is smaller than silver’ phenomenon caused by relativistic orbital contraction effects in gold, but the results also show that the magnitude of this effect is dependent on the nature of the metal–ligand bonds involved, and on changes in the metal coordination environment, which can in some circumstances yield trends in which the effect on particular bonds is partially masked or even reversed.
Coupling of pinned magnetic moments in an antiferromagnet to a ferromagnet and its role for exchange bias
Authors: Yaqoob Khan M , Shokr Yasser A , Kuch Wolfgang
Published: October 2019

The interaction between uncompensated pinned magnetic moments within an antiferromagnetic (AFM) layer and an adjacent ferromagnetic (FM) layer responsible for the existence of exchange bias is explored in epitaxially grown trilayers of the form FM2/AFM/FM1 on Cu3Au(0 0 1) where FM1 is ~12 atomic monolayers (ML) Ni, FM2 is 21–25 ML Ni, and AFM is 27 ML or 50 ML Ni~25Mn~75. Field cooling for parallel or antiparallel alignment of the out-of-plane magnetizations of the two FM layers does not make a difference for the temperature-dependent coercivity (H
C), magnitude of exchange bias field (H
eb), AFM ordering temperature (T
AFM), and blocking temperature for exchange bias (T
b). We explain this by a model in which the uncompensated pinned magnetic moments distributed within the volume of the AFM layer interact with both of the FM layers, albeit with different strength. Parallel and antiparallel coupling between the magnetization of the pinned moments and the FM layers equally exists. This leads to the experimentally observed independence of H
C, H
eb, as well as of T
AFM and T
b on the magnetization direction of the FM layers during field cooling. These results provide new and detailed insight into revealing the subtle and complex nature of the exchange bias effect.
Neutron MIEZE spectroscopy with focal length tuning
Authors: Jochum J K , Wendl A , Keller T , Franz C
Published: October 2019

We report on a method to tune the focal length of high resolution neutron MIEZE spectrometers. The MIEZE technique relies on a fast sinusoidal neutron intensity modulation up to the MHz range, generated by the rotation of the neutron spin in radio-frequency spin flippers, and subsequent conversion to an intensity modulation by a spin analyzer. This intensity modulation is washed out due to the neutron velocity dispersion, but by proper choice of the spin rotation frequencies as well as the distances between sample, detector and spin flippers, a focal point in space appears (echo point), where the neutron detector is placed. In this work, we describe how to extend the dynamic range of the MIEZE technique by several orders of magnitude by introducing a field subtraction coil (NSE coil), such that at low energy resolution a good overlap with conventional spectroscopy techniques is achieved. All formulas for calculating the tuning parameters and an experimental example from the RESEDA spectrometer at the Heinz Maier–Leibnitz Zentrum (MLZ) are discussed.
Ultra-giant magnetoresistance in graphene-based spin valves with gate-controlled potential barriers
Authors: Tseng Peng , Hsueh Wen-Jeng
Published: October 2019

Pursuing larger tunnel magnetoresistance is a significant work to develop attractive spin-valve devices for high-performance read heads of hard disk drives, magnetic random access memories, and transistors. Here, we propose an ultra-giant magnetoresistance reaching higher than 40 000% at room temperature by using a spin valve of an armchair graphene nanoribbon with double gate-controlled potential barriers. The ultra-giant magnetoresistance approximately 60 times larger than that of traditional MgO-barrier spin valves is caused by an extraordinary current suppression in the antiparallel mode. Moreover, owing to the concept of the gate-voltage barrier, the proposed system provided not only lower complexity of the fabricating standard but also longer endurance of the operation than traditional spin-valve devices.
Digital native levels of Indonesia pre-service teachers
Authors: Sejati A P , Suryana D , Handayani S R , Yuliana D
Published: October 2019

The generation classification based on technology proficiency skill consists of digital native and digital immigrant. Digital native assumed as superior in technology usage. Viewed from demographic aspects related to age, elementary school-age children of the current era tend to adopt the digital native characteristic. These characteristics may require teachers to integrate the learning methods and technology. This study aims to assess pre-service teachers’ digital native characters. They are projected to be teachers of digital native students. The assessment was made by using the Digital Native Assessment Scale developed by Teo in 2013. The use of the instrument was intended to pilot the DNAS in Indonesia education context. This study used a qualitative research design, since it involves qualitative data and analysis stages. The sample involved were 130 students (112 females and 18 males) of the Elementary School Preservice Teacher in Indonesia. Their age ranged from 18 to 24. Based on the study results, the digital native level of preservice teachers in Indonesia was high. If seen from a gender variable, the digital natives do not have any significant differences. Although this result cannot be fully generalized, it can be used as a reference both for curriculum development in teacher education.
Energy and indoor climate measurements in Denmark’s first energy neutral block of flats
Authors: Wittchen Kim B. , Jensen Søren Østergaard
Published: October 2019

Denmark’s first energy neutral multi-family house, BOLIG+, is constructed at Søborg near Copenhagen and consists of 10 flats divided on 4 floors. BOLIG+ was the first attempt to construct a multi-family block of flats that complies with a set of criteria and dogmas that defines the BOLIG+ concept. Energy production on the building needed e.g. to meet not only the buildings energy demand, but also the residents’ electricity energy use for light and appliances. Additionally when exchanging energy with the grid, energy “sold” should have at least the same exergy level as energy “bought”. Building multi-family houses that are energy neutral on annual basis, is, therefore, much more difficult than for a single-family house. One of the reasons for this is the small amount of roof area available (per. dwelling) for local electricity production compared to the roof area of a single-family house. Last, but not least, the buildings was constructed under normal economical market conditions, i.e. without any subsidies for the construction.

When designing the building, the normal standard conditions for calculating the buildings energy performance was offset in order to ensure better coherence between the design energy demand and the following energy measurements. The indoor temperature was set higher, and so was the domestic hot water demand. Additionally, free loads (gains) from persons, light and appliances was set lower than the standard.

To meet the goal of being energy neutral, several low-energy solutions are used e.g. compact thermal envelope; highly insulated constructions; highly insulating windows; hybrid decentral ventilation; heat recovery on grey wastewater; PV on facades and roof; buffer zones. Additionally, an electric battery was installed to improve the economy of the PV installation by optimizing the amount of electricity used inside the meter (tackling the feed-in tariff issue).

This paper presents results from 1½ year of measurements of energy performance and indoor climate carried out in the building during the period 2017-2018.

Measurements of energy consumption showed that if the PV installation has produced as expected and the residents had used electricity as expected, the building would have been only 11% from being energy neutral.

Indoor climate measurements show high temperatures in a large share of the period.
A tool for the parametric assessment of operational energy use and embodied GHG emissions in a single-family house concept study
Authors: Wiik Marianne Kjendseth , Lolli Nicola , Fufa Selamawit Mamo
Published: October 2019

Present day European legislation focuses upon the reduction of greenhouse gas (GHG) emissions in buildings through better design and technological solutions, with a view to reduce operational energy use and embodied GHG emissions. Currently, environmental performance assessment tools for buildings lack in assessing these parameters over the entire lifecycle of a building. Life cycle assessment (LCA) is a well-established methodology that gives a clear insight into the potential environmental impacts during the service life of a building. However, architect, engineer and constructor (AEC) professionals consider LCA as complex and time consuming. This paper builds upon a methodology for the development of a parametric analysis tool (PAT), which comprehensively assesses operational energy use and embodied GHG emissions during the lifecycle of a building. In this phase of the PAT’s development, the complexity of the tool has been increased by expanding the number of parameters from four (i.e. insulation thickness, window types, North façade glazing area and South façade glazing area) to seven (i.e. climatic zones, solar shading and electricity emission factors). This has increased the amount of parametric permutations from 1,372 to 12,348. The PAT has been applied to a conceptual two-storey single-family house, developed by the Norwegian ZEB Research Centre, which is assumed to be in either Oslo (Norway) or Lecce (Italy). The results show that the choice of insulation thickness influences total energy use less than the selection of shading types or glazing areas. The results also show the parametric selection with the least amount of operational energy use (34kWh/m2/yr) in the Lecce climate consists of triple-glazed windows (0.5W/m2k), 10m2of glazing on the north façade, 20m2of glazing on the south facade. The results show the parametric selection with the lowest total GHG emissions in the Oslo climate (7.8kgCO2eq/m2/yr) consists of triple glazing (0.5W/m2k), 10m2of glazing on the north facade and 20m2glazing on the south facade. This is because a lower electricity emission factor (132gCO2eq/kWh for Norway and 290gCO2eq/kWh for Italy) was used for converting operational energy use to GHG emissions, even though the Oslo climate has a higher heating demand compared to Lecce. In conclusion, this paper shows how complex design options can be evaluated in a holistic way through PAT to ascertain the best selection of design criteria for low GHG emissions and low operational energy use.
Perimeter Blocks in Nordic Towns - How latitude affect daylighting
Authors: Sundborg Bengt , Matusiak Barbara Szybinska , Arbab Shabnam
Published: October 2019

One of the design principles for future sustainable towns is compactness. The densification of cities is very much needed, but it usually compromises the access of daylight. Densification is especially challenging in the Nordic region characterized by low angled sunlight, something that also limits daylight distribution and restricts its intensity. The higher the latitude, the greater is the difficulty in the distribution. Perimeter blocks give shelter from wind and often create semi-public courtyards which have been seen to be attractive in many Nordic settlements during history. In the present study, alternative design to the conventional perimeter blocks are explored and geometric options such as chamfered corners, strategically varied building heights and differently positioned openings in a broken perimeter block are analyzed. The yearly simulations as well as simulations for May 1st have been carried out for the same perimeter blocks located at four different latitudes (decimal coordinates):

1. 65.0 Oulu (similar to Mo i Rana 66.3, Jokkmokk 66.6 and Rovaniemi 66.5)

2. 63.4 Trondheim (similar to Reykjavik 64.1, Östersund 63.2 and Vaasa 63.1)

3. 59.3 Stockholm (similar to Oslo 59.9, Helsinki 60,2, Tallinn 59.4, Saint Petersburg 59.9 and Anchorage 61.2)

4. 55.7 Copenhagen (similar to Malmö 55.6, Glasgow 55.9 and Moscow 55.8)

The choice of evaluation criteria is based on scientific discourse in the field of daylighting. According to the new European standard, solar radiation is included. Computer-based daylighting simulations are performed for different designs of the perimeter blocks with equal density, FAR = 1.33. The further north a city is located, the lower the houses in a perimeter block must be to maintain a certain level of daylight. The study confirms that latitude affects daylighting and that geometrical change can improve the conditions for daylight in the perimeter blocks.
Lessons learnt from the design and construction strategies of two Norwegian low emission construction sites
Authors: Fufa Selamawit Mamo , Wiik Marianne Kjendseth , Mellegård Sofie , Andresen Inger
Published: October 2019

Over the last couple of years, research related to fossil free and emission free construction sites has developed rapidly in Norway, with an ambition to contribute towards global, national and regional emission reduction targets. Major public players are already demanding fossil free construction sites through public procurement, whilst requirements for emission free construction sites are on the way. Even though the Norwegian construction industry is a forerunner, there is a lack of knowledge or common understanding among different stakeholders on the definition, scope and strategies needed for fossil free and emission free construction sites. The aim of this paper is to present the main challenges and opportunities from the construction phase of two Norwegian zero emission construction sites, namely Campus Evenstad in Hedmark and Lia nursery school in Oslo. Construction activities considered include transportation and installation of building materials, construction machinery, temporary works, energy use, waste management and person transport. This paper presents and discusses the lessons learnt from the design, ambition levels, inputs from stakeholders, emission reduction solutions of these two construction sites, and evaluates methods considered to address conceptual and practical issues. In conclusion, this paper suggests lessons learnt for reducing GHG emissions from Norwegian zero emission construction sites.
Defining a niche for Facilities Management in Smart Cities
Authors: Lindkvist Carmel , Temeljotov-Salaj Alenka , Collins Dave , Bjørberg Svein
Published: October 2019

A wide variety of disciplines engage in Smart Cities as the scope and breadth of it is broad. Within the built environment, there is much discussion on how planning and construction phases influence Smart Cities. There is little discussion on the role of Facilities Management (FM). However, there has been much work on the influence FM has on design phases to ensure functional and usable buildings. Neglecting to scale up the influence of FM from individual buildings to city scale may have long term consequences on sustainability of cities. Taking a mindset of including an FM perspective early in the development of a Smart City is considered here in terms of social aspects of required services. The work draws on ideas of Urban FM to operationalize local needs which also responds to the need to link to broader city sustainable strategies. The starting point is from the development of two districts in Trondheim, Norway. In a three-day workshop, students interpret the needs of the area based on their own knowledge-based perspective, guidance from tutors of Urban FM and through engagement with local users of the area. The work highlights the potential of including an FM perspective in the development of cities.
Reanalysis of occupant experiment in ZEB Living Lab
Authors: Skeie K S , Korsnes M S , Woods R
Published: October 2019

In 2015-2016, a six-month long experiment was carried out in the ZEB Living Lab, one of the first houses in Norway planned to reach net zero emission throughout its lifetime. By means of qualitative experiments, social scientists evaluated how six groups of occupants impacted the zero emission building, and how the zero emission building impacted its occupants in different ways. Data were collected through direct observation, diaries and interviews before, during and after the stay. In this paper, we take a closer look at the sensor data from the detailed monitoring system, generated during each group’s 25-day long residing’s. We find that despite the experiment being a controlled environment with many shared household characteristics, occupancy is determined by diverse factors, and the users’ preferences and attitudes influence energy consumption. All major household appliances were the same, but the time of use, frequency, duration and type of use differed. The study contributes to increasing understanding of user behaviour and energy use in low energy houses. Providing occupancy profiles is valuable, in light of the increasing amount of local renewable energy production. These datasets can be used as input in energy simulation and planning of zero-emission neighbourhoods.
Powerhouse Telemark: A plus energy building with a low exergy heating and cooling system
Authors: Tapper C S F , Dokka T H
Published: October 2019

Powerhouse Telemark (PHT) is an eleven stories high office building in Telemark in Norway, built to plus energy standard. A plus energy building that is built according to the Powerhouse definition prior to 2019 must produce more renewable, locally produced energy during the lifetime of the building, and must produce enough renewable energy to cover the total embodied energy used for the production and transportation of the building materials used in the building. The local renewable energy production must also cover the yearly net energy needs for operations, renovations and demolition of the building. The local production of renewable energy on the building is not required to cover the energy needed for plug loads in the building.

The building will have a unique diamond shape, and the roof of the building is oriented towards the south, and slopes at an angle of 24 degrees from the horizontal. The building will be a net supplier of electricity when seen over a whole year.

In addition to other “normal” measures to achieve a plus energy building, like a high performance building envelope, and an extremely efficient ventilation system, energy efficient lighting and equipment and a solar PV system, a new low exergy heating and cooling system has been implemented in the building. This low exergy system (called Lowex) is based on low temperature heating and high temperature cooling, which together with an optimized energy well design will give extremely low demand for delivered energy (electricity). To design this Lowex system, a lot of different calculations and simulations had to be done, both with commercial software packages, but also with new develop dynamic simulation models. These design procedures and models are described in this paper. This paper also describes how these results will be used for the operation of the building.

The building is currently under construction and will be commissioned in late 2019/early 2020. The main experience from the design phase and early construction phase is that the Lowex system sets strict demands on both façade design and the interior design. Transparent vs. opaque area ratios, solar shading and glazing solutions set boundaries for the architectural concept, and must be taken into account early in the design process. Flooring materials, ratio of landscape vs. office cells, and thermal zoning of the building affects the interior design. The acoustic concept and the carbon footprint of the building as well as the design of the supplementary HVAC-system are also important factors that need to be taken into account at an early stage in the design phase. To solve these interdisciplinary problems it requires a design team that can work together closely. The architect, and the engineer that is responsible for the energy performance of the building, have a central role to play at the very beginning of the design phase when the geometry and the general parameters of the building is still in flux.
Lia Kindergarten – A plus energy building: First year experience with regard to energy use
Authors: Dokka Tor Helge , Myrup Maria , Solsem Morten
Published: October 2019

Lia kindergarten is designed to be a plus energy building. The kindergarten was opened in January 2018, and the first year has been a tune-in phase for the technical systems. The plus energy concept consist of a well insulated building envelope, a highly efficient ventilation system, a lighting system with LED-fixtures and advanced control system and a low exergy thermal energy supply based on geothermal wells and a small inverter heat pump. The energy demand is balanced with a solar PV-system on the roof to achieve the plus energy definition. A lithium-ion battery package of approximately 40 kWh has been installed for peak shaving and to utilize more of the solar energy produced on the building (reducing mismatch).

A lot of research, calculations and simulations has been done in the design phase for the low exergy system. The floor concrete slab with embedded heating (pex pipes) is designed for very low temperature heating (22-28 °C). The floor system is reversed in the summer providing high temperature cooling (18-19 °C) which also charge the geothermal wells for the heating season. The calculations and simulations has also been used to make control strategies based on model predictive control (MPC) methodology, also taking in on-line weather forecast.
Facade Integrated Photovoltaic, state of the art of Experimental Methodology
Authors: Xiang Changying , Matusiak Barbara Szybinska
Published: October 2019

The concept of Building-integrated Photovoltaics (BIPV) is one of the most promising strategies to employ clean energy in the built environment. Up to now, the PVs have been applied mostly on roofs, but since the total roof area is insufficient, there is a need to integrate photovoltaics on building façades as well. This challenges not only the architectural design of a single building but also the visual image of urban environment, as photovoltaics have to harmonize with conventional building materials used on building facades as brick, concrete, wood, etc. Aiming to provide a foundation for research exploring facade-integration methods that will ensure successful architectural result, the paper presents a state of the art on façade integrated photovoltaics (FIPV) with focus on the experimental research methodology. It embraces both, theoretical research and PVs applications in building projects. As pure computer simulations are not recognized as an experimental methodology, papers conveying such generated results have not been included. In addition, the research that deals exclusively with energy aspects is omitted. The study is based on a comprehensive literature review. Advanced experimental methodologies from selected literature are described and categorized according to the scale (building or urban) and the transparency of the PVs (opaque or translucent). Then detailed features of PV experimental methods are demonstrated in structured tables for analysis and discussion. The study shows that even though solid scientific methods are used to evaluate single features of PVs, e.g. colour or reflectance, there is an obvious lack of methodology providing holistic assessment of Façade-integrated Photovoltaics, especially at the urban scale. The further research will lead toward developing of evaluation criteria framework (in interdisciplinary cooperation) and then provide a holistic methodology combining qualitative and quantitative methods for a successful FIPVs in urban context.
Design and build with straw, earth and reeds for a minus carbon and plus energy building practice
Authors: Dabaieh Marwa
Published: October 2019

The 6Zs target refers to the concept of a minus carbon and plus energy eco-cycle refugee house. A 37 m2 house was designed and constructed in a participatory manner in the City of Lund, Sweden. The 6Zs include: zero emissions, zero energy, zero waste, zero cost, zero indoor air pollutants and zero impact on the environment after the shelter is demolished. The key idea of this eco-cycle house is to reach net 6Zs during all stages—material extraction, building construction, operation and maintenance—until the shelter’s end of life. The main construction material is plant-based raw fibers (mainly straw and reed), which are available around the building site. This house is designed to accommodate the needs of two adults and one child. It was built with the help of 7 refugees in 11 working days through an experimental participatory urban living lab methodology. The paper discusses the 6Z design concepts and draws conclusions on the preliminary assessment of the house prototype that was built as a proof of concept. The beneficiaries of this project are not restricted to refugees but also include the majority of individuals and families seeking affordable ways of living with a low impact on the environment. The house is designed for the cold Swedish climate, but the design concept and methodological approach can be adjusted to other climates or geographical contexts.
Disturbance Frequency 9 – 150 kHz Characteristics towards Total Demand Distortion on On-Grid Solar Panel System in the Electrical System of Kuningan Gas Station
Authors: Purnamaputra R P , Sudiarto B
Published: October 2019

To use solar energy into electricity, a solar panel system is needed which of course uses solar panels. As we know, a solar panel system has quite a lot of non-linear equipment, for example is an inverter. The use of this inverter will affect the power quality of the output of solar panels, one of which is disturbance. At a frequency range of 9 – 150 kHz, electrical equipment with an inverter will produce a disturbance in the system. So, in this paper, the study was conducted to observe the characteristics of the disturbance frequency of 9 – 150 kHz towards total demand distortion on on-grid solar system in the electrical system at the gas station so that it can be used as a guide for future disturbance and solar energy research.
Tristaniopsis merguensis Griff. Extract as Inhibitor for Corrosion of Stainless Steel
Authors: Roanisca O , Mahardika R G , Setiawan Y
Published: October 2019

Green inhibitors are inhibitors that utilize secondary metabolites of plant to reduce the rate of corrosion. Secondary metabolites with heteroatom content phosphate, nitrogen, oxygen and sulfur function as ligands and adsorption centers to bind metals. These metabolites compounds include alkaloids, flavonoids, and tannins. Tristaniopsis merguensis Griff. is a local plant of Bangka Belitung which contains alkaloid, flavonoids and tannins. The focus of this research is to analyze the effect of T. merguensis leaf extract on corrosion rate of stainless steel. T. merguensis extract was obtained by maceration for 3 x 24 hours using ethanol solvent. Determination of corrosion rate using the mass reduction method. Then, functional group analysis contained in extract uses the Fourier Transform Infrared (FT-IR) at wavenumber region 4000–400 cm−1. The results obtained that at the highest concentration of 1000 mg/L the extract of T. merguensis was able to inhibit the corrosion rate of stainless steel until the corrosion rate was 0.3826 mmpy equal to inhibition efficiency 85.27%. This inhibiting ability is more likely because T. merguensis leaf extract containing phenolic compounds. Therefor T. merguensis extract can be used as a green inhibitor.
Utilization of FABA Waste from coal combustion at the PLTU Air Anyir as an alternative to local construction materials
Authors: Yofianti D , Yukho H A
Published: October 2019

FABA (fly ash and bottom ash) is a by-product of coal combustion at the Air Anyir steam power plant (PLTU), in the Province of the Bangka-Belitung Islands. The waste generated from this PLTU always increases every year, but its utilization is not getting the attention of the related parties. In connection with these reasons, the aim of this study was to analyse the advantages and disadvantages of FABA utilization and to identify barriers in applying the use of FABA as an alternative to local construction materials. The in-depth interview method was selected in this study to obtain detailed information regarding FABA issues. The interviewees were derived from the internal and external parties of the PLTU Air Anyir. The interview results were analysed using the narrative method. The results of this study are expected to encourage relevant parties to use FABA as an alternative substitute for construction materials.
Characterization of aluminum oxide nanoparticles using egg white as a trap-matrix
Authors: Noor A , Afriani F , Rafsanjani R A , Tiandho Y
Published: October 2019

In this article, we add egg white (albumen) to the synthesis of aluminum oxide nanoparticles (Al2O3). Egg white can be used as a trap for the aluminum oxide particle matrix to prevent agglomeration of aluminum oxide particles during the synthesis process. To determine the effect of pH on the characteristics of aluminum oxide crystals formed, variations in pH were carried out starting from 7, 9 to pH 11. The calcination temperature used was 1000°C. We used the results of XRD analysis to determine the crystalline size and crystallinity of aluminum oxide nanoparticles. pH 7 shows the size of the smallest nanoparticles of crystals and the relatively large levels of crystallinity.
The Effect of Temperature and Twist Ratio from Twisted Tape Insert to Pumping Power in Concentric Exchange Tools using Nanofluida TiO2 and Oli Termo XT-32
Authors: Wibowo B S , Setiawan Y , Radiyan F
Published: October 2019

The heat exchanger is a device used to heat between two or more fluids. Heat exchangers can use fluid flow or construction. Heat exchangers are widely used in engineering applications. The heat exchanger has long been recognized by industries that relate to heat transmission phenomena. Improve the speed of all types of heat exchangers widely in the industry, in the process of retrieval (heat recovery process), air conditioning, and chemical reactors. Increasing the amount of light flow can be done in several ways, namely: flowing inequality, damaging the boundary layer, changing the fluid flow, and rotating fluid flow (vortex flow). One of the techniques used to increase the heat coefficient of convection is to provide insert material or often called Insert. The research methodology was to determine the effect of the rotational ratio of the insertion bent band on the pumping power of the pipe heat exchanger by using TiO2 nanofluid with a heat transfer oil base fluid (thermo XT32). This research was carried out with experimental methods, as for the tools and research materials in this case: primary fluid of thermo XT32, TiO2 nanoparticles, and an annular channel concentric pipe heat exchanger by inserting a bent band. In and out data (Th, i and Th, o), the temperature of the fluid in and out of the annulus (Tc, i and Tc, o), the outer wall temperature of the inner tube (Tw1, Tw2, Tw3, Tw4), and the water height difference on the manometer. Data collection was carried out with TiO2 particle nano samples with a volume fraction of 0.3% Vol, without a bent band. Insert (plain tube) and rotate the tape with a touch ratio of 3, 6, and 9. The results of the research carried out on the conclusion of the rotational ratio in the band bending the insertion of the pumping power of the heat exchanger. This proved the pumping power increases with decreasing rotational ratio from a bent band, the addition of a twisted tape insert can increase the pumping power when compared to a pipe heat exchanger without concentrically turning the inserted tape (plain tube), this is proven by using a twisted tape insert with a twist ratio of 3. It requires a pumping power of 87.71 W / m2 to be able to drain TiO2 nanofluid, with a volume fraction of 0.3% Vol at a fluid temperature of 60 °C whereas when compared to a heat exchanger without turning the inserted tape (plain tube), it only requires pumping power of 17.73 W / m2. to be able to drain nanofluid in a heat exchanger.
Contact pressure analysis of slewing rings
Authors: Skyba R , Hrček S , Smetánka L , Majchrák M
Published: October 2019

The paper deals with creation of functional parametric 3D model of slewing bearing. The slewing bearing is loaded by the radial force that acts from the centre of the bearing and it is also perpendicular to the axis of bearing. 3D fully parametric model of slewing ring was designed in Creo Parametric 3 and it is controlled by the ball diameter. To calculate several geometric bearing modifications, the 3D model from Creo was imported to the Ansys Workbench computational program. Based on many analysis in Ansys, it is possible to evaluate the size of contact pressures, determine the most loaded place and compare values between individual bearing modifications. By transferring the measured values of the contact pressures to the Microsoft office, it was possible to construct a graphical dependence between the values of measured stresses and the magnitude of the radial force acting on the slewing bearing.
Kinematic method of envelope points calculation when the wraparound points are known
Authors: Babichev D A , Babichev D T , Yu Lebedev S
Published: October 2019

There are two kinds of surfaces that are formed by the movable bodies: wraparound and envelope surfaces. In this work the authors develop velocity (kinematic) envelope points’ calculation method, when the envelope is known. The method is approximate; and based upon the usage of terms “speed and acceleration”; and lets reduce the amount of calculation using undifferentiated methods of envelope estimation
Case study on topology optimized design for additive manufacturing
Authors: Aliyi A M , Lemu H G
Published: October 2019

Additive Manufacturing (AM), also known as rapid prototyping, rapid manufacturing, layer manufacturing and three-dimensional printing, represents one of the most promising aspects of manufacturing for highly complex geometries. In particular, AM is nowadays seen as provider of possibilities to realize true design optimized manufacturing through topology optimization. Topology optimization is an approach that is considered powerful in design because it contributes to a design that can save energy, materials and time that are not economically achievable using other manufacturing processes. This paper is intended to explore the potentials of topology optimized design approach for AM in developing products that are lightweight and at the same time efficient and have load bearing capacity. A case study has been conducted to demonstrate the steps involved in topology optimization and its benefits in terms of weight reduction.
Possibilities of intelligent flexible manufacturing systems
Authors: Kostal P , Mudrikova A , Michal D
Published: October 2019

The basic requirement of production is to produce as many products as possible, at the lowest cost, with the highest possible quality. These requirements can be met with the new "Intelligent Production" paradigm. In particular, this paradigm involves the use of intelligent manufacturing systems and the introduction of intelligent production management. In this article, we'll look at intelligent manufacturing systems. The intelligent manufacturing system itself is a flexible manufacturing system that can flexibly respond to changes in production requirements as well as changes in its surroundings and interact with its surroundings. As a result of these flexible responses, there is less space, reduced production and investment costs, and increased productivity.
Designing and optimizing extractors for automated dispensers
Authors: Hajducik A , Smetanka L , Medvecký Š , Škrabala J
Published: October 2019

Currently, the process of manufacturing the goods and then distributing them to the customer is constantly optimized, accelerated and automated. For these aspects, goods handling and automated storage play a key role. This article focuses on designing and optimizing the mechanisms that are parts of vending machines. Both static and dynamic models of mechanisms are presented, also the thesis describes the configuration and operating principle of given mechanisms. The mechanisms have been designed to handle for instance boxes, reliably and precisely, they were subjected to dynamic analysis. Several principles of the various mechanism are presented. After this, the functionality of some mechanisms was verified by analysis. These models of extractors can be used in food dispensers, vending machines in libraries, pharmacies, and stores of specific goods. The presented mechanisms are particularly suitable for medicine dispensers and pharmacy environments.
Effect of reinforcement on mechanical characteristics of A356 alloy nanocomposites
Authors: Velickovic S , Stojanović B , Djordjević Z , Miladinović S , Blagojević J
Published: October 2019

Nanocomposites with aluminum base reinforced with nanoparticles, have wide application in many industries, for example, aerospace, marine, automobile, due to its lightweight, high tensile strength and high wear resistance, etc. The study of the microstructure, mechanical and tribological properties of the nanocomposite is very important in order to reliably and optimally carry out the design of new materials. In this study for the mechanical characterization of the A356 composites with a ceramic particle reinforcements nanoindentation was performed. Nanoindentaion is largely used for the analysis of mechanical properties. The samples of the nanocomposites were developed using 0, 0.2, 0.3 and 0.5 wt.% SiC, with an average size of particles of about 50 nm, produced by a compocasting process with pre-processing mechanical alloying. Nanoindentation was carried out based on Berkovich's test method with the indenter in shape of three sided diamond pyramid. The nanocomposite testing showed that the nanocomposites containing 0.5 wt.% of the reinforcement have slightly higher tensile strength and a lower value of the elastic modulus compared to the aluminum alloy base.
The influence of different lamina positions on buckling properties of composites plates under biaxial compression
Authors: Jeremic D , Radić N
Published: October 2019

The present work focused on the buckling of composite plates subjected to biaxial compression using classical laminated plate theory (CLPT). The two composite plates are bonded by an elastic medium. Classical laminated plate theory (CLPT) is utilized for deriving the governing equations. Difference between 4-ply symmetric lamination scheme with different material properties and fiber orientation angle (0° and 30°) is shown. The study show that the mechanical properties of the composite materials depending on the fiber orientation angle and lamina positions.
Estimation of laser cutting process efficiency
Authors: Girdu C C , Mihail L A , Dragoi M V
Published: October 2019

The efficiency of laser cutting processes is generally treated in technical literature in qualitative terms, referring to ways to increase it. The present paper is focussed on metal cutting by laser and proposes some quantitative means to estimate the process efficiency. For certain working conditions – machine-tool, material to be processed, specific costs and other – the effectiveness and the specific power consumption are computed based on the main cutting parameters: laser power and cutting speed. The proposed mathematical relationship can be successfully used when the criterion of process optimization is the environment friendliness. A relevant case study is presented, as well. When significant different samples are to be compared, the criterion used to evaluate laser cutting efficiency becomes very important.
Determination of operating parameters of turbines for micro hydroelectric power plants for optimal use of hydropower
Authors: Prodanovic M , Miltenović A , Nikodijević M
Published: October 2019

Energy trends have been mostly focused on renewable energy sources in recent years. In the world, about 20% of electricity is produced using energy of water flows, ie. hydropower with a total installed power of 720 GW. The production of hydroelectric power has a number of advantages from fossil fuels or nuclear energy and the greatest is that it does not pollute the environment. In mountainous areas, small and micro hydro power plants are often used, which can be installed on small rivers or streams with little or negligible impact on the environment. The choice of the type of turbine is influenced by a number of parameters, which should be determined before the complete project of the micro hydroelectric power plant. For turbines that are most commonly used in micro hydroelectric power plants, the process of determining operating parameters for optimal utilization of available hydro power is presented in the paper.
Determining of the drive power of a transport machine for disabled persons using a computational model
Authors: Blatnický M , Dižo J
Published: October 2019

The article deals with calculation of a stair lift drive and its design. The aim is the determining the necessary power of the used electric motor depending on the variable input values such as a passenger weight, a gradient of the seat lift etc. Calculating the required power for operation of the equipment is essential for selecting the optimal drive motor. In practice, the mathematical-physical principle of solving a problem such as drive calculation is often neglected. This results in the use of excessively powerful propulsion equipment, and thus in excessive financial cost in mass production. Consequently, by designing a drive-train, it will be possible to design the entire drive mechanism, i.e. motor, gearbox, gear module, etc. A significant part of the overall solution will be the design of the shaft for the drive pinion and its analytical dimensional calculation in comparison with the numerical solution. This will fulfil the prerequisites for optimizing the current shaft design by reducing its mass from the current value of 1.185 kg while the safety and reliability conditions of the construction are still met.
Technical solution of the under locomotives visual inspection system
Authors: Miltenovic A , Stamenković D , Banić M , Simonović M
Published: October 2019

In recent years, liberalisation of rail cargo operators market brought to the position of a number of small rail operators that are operating on rail infrastructure. Most of them are relatively small with specific cargo transport products, limited number of locomotives and wagons and with limited service resources. Independently of the cargo operator size, they are also obligated to have regular inspections according to the railway regulations. Inspections are frequent and in normal cases they need special depot with inspection pit that small operators do not possess. In the paper are given technical solutions that can be found in the market as well as developed and proposed equipment solution with different concepts for the under locomotives visual inspection without using inspection pit. In the paper is also carried out evaluation and choice of proposed solutions as part of regular product development process.
Estimation of the influence of the interaction of factors pairs on the coefficient of route execution possibility
Authors: Puzyr V G , Krasheninin O S , Zhalkin D S , Datsun Y M , Obozny O M
Published: October 2019

Successful execution of a route by a locomotive can depend on the combination of various operational factors. As an indicator that characterizes the reliable operation of locomotives in exploitation, the coefficient of route execution possibility is proposed to use. The task is to get a formula by which it would be possible to obtain the value of the coefficient of route execution possibility with different combinations of factors. As a tool for obtaining an interpolation formula for determining the coefficient of route execution possibility, a full factor experiment was chosen. The calculations of the model coefficients were carried out with a pairwise combination of four factors: the profile of the area, experience of the driver, the length of the shoulder, the weight of the train. The obtained models were checked for adequacy by F-test. On the received models in three-dimensional coordinates surfaces, reflecting the value of the coefficient of route execution possibility in the intervals of factorization, were constructed. An analysis of the obtained surfaces and the distribution of the selected factors by the degree of impact on the coefficient of route execution possibility were carried out.
Railway carriage mass impact on retarder noise
Authors: Zvolensky P , Kollar M , Lestinsky L , Dungel J
Published: October 2019

The paper is aimed on railway brake noise on set up track in a Teplicka nad Vahom arranging station. On the basis of noise measurements, it is possible to determine the presumption of impact of rail brake operation on municipalities in the vicinity of the set up rail area and to adjust its technology in the time frame so that the statutory noise limits are not exceeded. Also is possible to determine, if it is possible to use the technology in praxis to pass requirements for statutory noise limits. For operators of the arranging station and railway brakes is very important to set time schedule properly for every freight train set. It is precisely for this reason that technology can be designed according to the catchment density and the duration of the individual wagon alignment so that the freight trains concerned are not delayed. It is also possible to take into account that a shifted group of wagons with lower weight per axle will cause less braking noise.