bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies pertaining to the monitoring of volatile halogenated anaesthetics in breath by proton transfer reaction mass spectrometry
Authors: Malásková Michaela , Olivenza-León David , Chellayah Prema D , Martini Judith , Lederer Wolfgang , Ruzsanyi Veronika , Unterkofler Karl , Mochalski Paweł , Märk Tilmann D , Watts Peter , Mayhew Chris A 
Published: December 2019

Abstract
Post-operative isoflurane has been observed to be present in the end-tidal breath of patients who have undergone major surgery, for several weeks after the surgical procedures. A major new non-controlled, non-randomized, and open-label approved study will recruit patients undergoing various surgeries under different inhalation anaesthetics, with two key objectives, namely (1) to record the washout characteristics following surgery, and (2) to investigate the influence of a patient’s health and the duration and type of surgery on elimination. In preparation for this breath study using proton transfer reaction time-of-flight mass spectrometry (PTR-TOF-MS), it is important to identify first the analytical product ions that need to be monitored and under what operating conditions. In this first paper of this new research programme, we present extensive PTR-TOF-MS studies of three major anaesthetics used worldwide, desflurane (CF3CHFOCHF2), sevoflurane ((CF3)2CHOCH2F), and isoflurane (CF3CHClOCHF2) and a fourth one, which is used less extensively, enflurane (CHF2OCF2CHFCl), but is of interest because it is an isomer of isoflurane. Product ions are identified as a function of reduced electric field (E/N) over the range of approximately 80 Td to 210 Td, and the effects of operating the drift tube under ‘normal’ or ‘humid’ conditions on the intensities of the product ions are presented. To aid in the analyses, density functional theory (DFT) calculations of the proton affinities and the gas-phase basicities of the anaesthetics have been determined. Calculated energies for the ion-molecule reaction pathways leading to key product ions, identified as ideal for monitoring the inhalation anaesthetics in breath with a high sensitivity and selectivity, are also presented.
Influence of curing conditions on mechanical and fracture properties of alkali activated slag concrete
Authors: Šimonová H , Kucharczyková B , Bílek V , Topolář L , Kocáb D 
Published: December 2019

Abstract
The aim of this work is to determine the physical, mechanical and fracture characteristics of concrete specimens with alkali activated binder cured at different conditions. The concrete mixture with alkali activated ground granulated blast furnace slag was selected for the purpose of the experiment. The binder was activated by the liquid sodium silicate with the silicate modulus of 2.0. Natural sand and gravel were used as a fine and coarse aggregate, respectively. The maximum aggregate size was 16 mm. The binder : aggregate : water ratio was 1 : 3 : 0.46. During the specimens ageing, the dynamic modulus of elasticity was determined using a resonance method. The fracture characteristics were determined based on the results of the three-point bending test of specimens provided with an initial central edge notch. The fracture experiments were conducted at the age of 3 and 38 days. The loading force (F), the displacement measured in the middle of the span length (d), and the crack mouth opening displacement (CMOD) were continuously recorded during the test. The records of fracture tests were subsequently evaluated using the effective crack model, work-of-fracture method and double-K fracture model. The fracture tests were also accompanied by the monitoring of acoustic responses using the acoustic emission method.
Mechanical Properties of Geopolymer Concretes Reinforced with Waste Steel Fibers
Authors: Gailitis R , Korniejenko K , Łach M , Sliseris J , Morán J , Rodriguez E , Mikuła J 
Published: December 2019

Abstract
The article presents the research that try to determinate the possibilities of utilization the waste came from used tires to create the composites based on geopolymer matrix. The tire is multicomponent construction. It mainly consists of elastomer (rubber), metal and textile fibres such called textile cord. A lot of components causes difficulties in the tire recycling process. The main aim of the research was determinate the possibilities of recycling the waste steel from used tires in geopolymer composites and develop the eco-friendly material for construction industry. The matrix based on fly ash from power station located in city named Skawina (Poland) and fine sand at a ratio of 1:1. The process of activation was made by 10M sodium hydroxide solution combined with the sodium silicate solution. In order to manufacture these composites the addition of 2% and 3.5% of waste steel fibres by mass was applied. Also specimen without steel fiber reinforcement were made to get reference specimens. The waste steel fibres came from recycling company from Argentina – ‘Regomax’. The specimens were prepared according to the methodology described in the standard EN 12390-1. The research methods used were: microstructure research, tensile strength and compressive strength tests as well as analysis of breakthroughs.
Synthesis of a Geopolymer Binders Using Spent Fluid Catalytic Cracking (FCC) Catalyst
Authors: Ruiz G , Aguilar R , Nakamatsu J , Kim S 
Published: December 2019

Abstract
A synthesis of a geopolymer binder using spent fluid catalytic cracking (FCC) catalyst is evaluated in this research. Spent FCC catalyst is a solid waste product from the oil refining industry worldwide. It is composed mainly by aluminium and silicon oxides. The silica modulus (Ms), NaOH molar concentration, and liquid/solid (AS/FCC) weight ratio were studied as key factors of the mixture composition for the evaluation of the compressive strength and bulk density of geopolymers. Additional total ratios of SiO2/Al2O3, Na2O/SiO2, and H2O/total solids, which consider chemical composition of the final mixture, were studied. Results indicate that there is an optimum value for each Ms, NaOH molar concentration and AS/FCC that produces the maximum compressive strength. These values also match with the optimized total ratios of SiO2/Al2O3, N2O/SiO2 and H2O/total solids in the mixture, which can be considered as alternative control parameters for the formulation process. The bulk density is more related to AS/FCC value. A geopolymer binder with a compressive strength of 24.7 MPa after curing for one day at 65°C and six days at room temperature was produced using this spent FCC waste.
3D computer drawing competition CADrina
Authors: Nõmm A , Mägi R , Meister K 
Published: December 2019

Abstract
CADrina is IT-festival, where takes place 3D computer drawing competition, which has been organized for 9 years by Kadrina Secondary School. In this competition AutoCAD program is used. Participants will create 3D objects in AutoCAD during a given period according to the specifications that will be provided. They will be judged on accuracy and speed. The competition took place in several rounds - the preliminary round and the final round. The event provides opportunities to showcase students’ knowledge and skills as well as to be a role model and inspiration for the future choice of young people. 3D computer drawing competition is a good chance to develop team-working skills under pressure among students.
Numerical investigation of influence of the temperature and relative humidity of air on the drying process of porous building
Authors: Wasik M , Łapka P , Cieślikiewicz Ł , Seredyński M , Furmański P , Pietrak K , Kubiś M , Wiśniewski T , Jaworski M 
Published: December 2019

AbstractThe impact of the relative humidity and temperature of air on drying rates of the porous building material was investigated by the non-equilibrium heat and moisture transfer model implemented in the ANSYS Fluent software. Simulations of 24 hours drying process of a brick initially saturated in 97% by water were conducted for two drying air temperature, i.e., 23.8°C and 40°C and relative humidity in the range from 10% to 50%. The relative moisture content at the end of simulations and times needed to reach the relative moisture content bellow 0.3 were determined. Not only the temperature but also the relative humidity of drying air had impact on the drying rate during the first drying period when water evaporated from the sample surface. The temperature of drying medium was more important than the relative humidity during the second drying period when water evaporated inside the brick. The drying process was faster in the higher temperature than in the lower one, even for the high relative humidity.
Experimental investigation of the influence of the relative humidity of air on the drying process of porous building materials
Authors: Cieślikiewicz Ł , Łapka P , Kubiś M , Wasik M , Pietrak K , Furmański P , Seredyński M , Wiśniewski T 
Published: December 2019

Abstract
The paper presents the experimental analysis of influence of the relative humidity of drying air on the drying process of porous building materials. Investigations were conducted by applying the stand which worked in a closed-loop flow and equipped with the following elements: the cooler (condenser), fan with variable rotation speed, throttle, humidifier, heater and control and acquisition systems. During experiments the temperature and velocity of air were equal to 40°C and 3 m/s, respectively, while its relative humidity was varied in the range from 16 to 40%. Two different materials were investigated, i.e., the red brick and mortar. Specimens were placed in the duct and had the top surface exposed to flowing air. Variations of the moisture content and temperature in considered building materials were measured by system of two force meters and thermocouples, respectively. The relative humidity of drying air significantly influenced on the drying process of building materials. The increase of the relative humidity of drying air resulted in the rise of the drying duration, the decrease of the drying rate and the increase of the level of temperature plateau (i.e., equilibrium temperature) which resulted from evaporation in the medium. Moreover, for the mortar drying rates were found much slower than for the red brick.
Impact flow and bed layering on equilibrium depth of scour at elliptical guide banks
Authors: Gjunsburgs B , Vilnitis M , Parilkova J , Bizane M 
Published: December 2019

Abstract
In the paper is present study the equilibrium scour at elliptical guide banks at different Fr number of the open flow, contraction, uniform or stratified bed model. A new approach for calculation equilibrium depth of scour at elliptical guide banks is elaborated and method for calculation equilibrium depth of scour bed at elliptical guide banks is presented. Analysis of the test, calculation and computer modelling results is made to estimate impact on relative equilibrium depth of scour: Fr number of the flow, local Froude number- FrVl
, FrVequil
, flow contraction, relative time, thickness and sequence of the bed layers. Relative equilibrium depth of scour is increasing with increase of Fr number of the open flow, local FrVl
number, FrV equil
at equilibrium depth of scour, relative time of scour, flow contraction and with different thickness and sequence of the bed layers. Calculation equilibrium depth of scour with the approach flow velocity and using the grain size only on the top of the bed or for the next layer calculate depth of scour with the same velocity, as it accepted nowadays, and neglecting changes of the flow parameters during the scour, bed layering can lead to wrong results and damages and losses.
Waste glass as a replacement for fine fraction in high-performance concrete
Authors: Mariaková D , Jirkalová Z , Laiblová L 
Published: December 2019

Abstract
Research project is focused on the experimental verification of high-performance concrete (HPC) with full replacement of fine fraction. This paper deals with HPC mixtures containing recycled glass materials (waste glass powder from municipal waste, waste glass powder from photovoltaic panels, grinding waste glass from jewellery). The research is based on the results of previous student grant. A recipe that was made during 2017 is used and optimized according to the waste glass powder properties. The influence of different local sources is monitored. The HPC mixtures are tested for mechanical properties (flexural strength, compressive strength) and compared with the results from the previous research. Flowability is tested and all the mixtures are workable. The mixture with grinding glass (GG) showed the highest results in flexural and compressive strength compared to the reference sample, the use as a substitute for fine fraction in HPC is conceivably attitude. The municipal waste glass mixture and the mixture with the waste glass from photovoltaic panels is not usable as HPC.
Properties of thin wall cement composites reinforced with AR glass, carbon and PVA fibres
Authors: Moceikis R , Kičaitė A , Sahmenko G , Korjakins A 
Published: December 2019

Abstract
Thin wall cement composites find a wide range of special applications for making light weight façade exterior wall and urban decorative elements, as well as a part of load bearing constructions. AR glass fibre is the most popular reinforcing material for producing glass fibre reinforced concrete (GRC). Possibilities for use alternative Carbon and PVA fibres are analysed in this work. The study is focused on investigation of technological and mechanical properties of thin wall (15 mm) cement composite plates reinforced by tree types of fibres.
Investigations on the foam concrete production techniques suitable for 3D-printing with foam concrete
Authors: Markin V , Sahmenko G , Nerella V N , Näther M , Mechtcherine V 
Published: December 2019

Abstract
With high thermal insulating property and low density, foam concrete has high potential in 3D-printing applications such as residential buildings. The synergy of the foam concrete and 3D-printing process pre-requisites research and optimization of foam concrete production. This paper presents investigations on the appropriateness of two different methods for production of foam concrete: 1) mixed foaming method in turbulence (colloidal) mixer and 2) mixed foaming method in cavitation disintegrator. Performance of synthetic and protein based foaming agents were examined. The dosage of the foaming agent was varied from 0.7% to 1.2% by weight of cement to produce foam concretes with densities ranging between 800 kg/m3 and 1500 kg/m3. The study shows that foaming ability of the designed concrete compositions depends primarily on their w-b ratio. Moreover, foaming with lesser dosage of foaming agent is possible when turbulence mixer is used. Furthermore, mechanical and physical properties of foam concrete, including compressive strength, bending strength, and water absorption were reported.
Behaviour of Timber-Concrete Joints in Hybrid Members Subjected to Flexure
Authors: Vasiljevs R , Serdjuks D , Gerasimova J , Buka-Vaivade K , Orhun Erüz A 
Published: December 2019

Abstract
Possibility to develop rigid timber-concrete joint for hybrid timber-concrete specimens was stated. Behaviour of timber-concrete rigid and compliant joints were evaluated numerically and by experiment for the members subjected to flexure. Small scale hybrid timber-concrete specimens with the length, width and thickness equal to 400, 95 and 43 mm were investigated for case of three points bending. The small-scale hybrid timber-concrete specimens consists from the layers of cement base finishing mass Sacret BAM and timber boards of strength class C24 with thicknesses equal to 25 and 18 mm, correspondingly. The rigid timber-concrete joint was provided by the pieces of crushed granite, which were strengthened on the surface of the timber boards by epoxy glue Sica Dur 330. Dimensions of the crushed granite pieces changes within the limits from 2 to 25 mm. The compliant timber-concrete joint was provided by the screws with diameter and length equal to 4 and 40 mm, correspondingly. The screws were placed under the angles equal to 45 and 90 degrees relatively to the direction of fibres of the timber layers. Load-carrying capacity and maximum vertical displacements were gotten for groups of small-scale hybrid timber-concrete specimens with rigid and compliant timber-concrete joints. It was shown that providing of rigid timber-concrete joint enables to decrease 1.86 - 3.50 times the maximum vertical displacements of hybrid timber-concrete specimens. Load-carrying capacity of the specimens grows by 16.5 – 50.0% at the same moment.
Efficient heat-insulating material based on technogenic anhydrite
Authors: Yakovlev G I , Kalabina D A , Pervushin G N , Drochytka R , Bazhenov K A , Gordina A F , Ginchitskaya J N 
Published: December 2019

Abstract
Physical and mechanical properties of the heat-insulating composition based on high-strength anhydrite binder with expanded perlite sand as a lightweight aggregate have been studied. The study has evaluated the influence of two poring components, air-entraining additives and aluminum powder suspension, on the main characteristics of the composition: the compressive strength of the sample, its average density, thermal conductivity, and water absorption. The studies have shown that adding an air-entraining agent in an amount of 1.2% by the weight of dry fluoroanhydrite significantly influenced the decrease in the average density (up to 37%) of the material. The developed composition with a lightweight aggregate based on expanded perlite sand and an air-entraining additive can be used in construction as an efficient heat-insulating material, including for filling cavity walls during frame construction.
Spectrophotometric evaluation of pigmented urethane acrylate coating colour stability
Authors: Grigale-Soročina Z , Birks I , Pilipavica R 
Published: December 2019

Abstract
The research was carried out testing two red pigment dispersion colour stability in UV light-curing urethane acrylate composition. The given urethane acrylate composition was pigmented with a pigment content of 0.1% to 5%. Coating colour change was evaluated at room temperature and at 50°C over a 28-day period. For all prepared pigment samples, spectrometric colour difference measurements were performed using CIEL*a*b* and CIEL*C*h* colour systems and FTIR-ATR to evaluate their stability over time. The colour stability was improved with increasing pigment concentration. There was found the difference between tested red pigments and can be concluded that one of them are more stable for use in pigmented coatings.
Variation of bending strength of fiber reinforced concrete beams due to fiber distribution and orientation and analysis of microstructure
Authors: Herrmann H , Boris R , Goidyk O , Braunbrück A 
Published: December 2019

Abstract
Fiber reinforced concrete is becoming increasingly popular as a construction material, as it can potentially form a ductile concrete. The properties of the fiber reinforced concrete depend on the concrete recipe, the flow of the fresh concrete into the formwork, possible vibrating of the concrete and the fiber orientations.
This contribution presents the results of bending tests performed on fiber reinforced concrete beam specimens, which have been cut out of a larger plate. These beams have different fiber orientation distributions, due to being taken from different parts of the plate and with different orientation with respect to the flow of the fresh concrete. Further, the microstructure of the concrete was investigated using scanning electron microscopy (SEM). The SEM shows no obvious differences in the microstructure between beams of different strength and shows good adhesion of fiber and concrete matrix in all investigated samples.
Recycling Municipal Solid Waste Incineration (MSWI) Fly Ash As Addition for Clay Brick
Authors: Voišnienė V , Kizinievič O , Kizinievič V 
Published: December 2019

Abstract
The authors analyses the possibilities of recycling municipal solid waste incineration (MSWI) fly ash in clay brick manufacture. The paper analyses the effect of MWSI fly ash (FA) on physical-mechanical characteristics, environmental toxicity of clay bricks. The clay bricks were prepared by adding 2.5-7.5 % of FA and firing them at 1000 °C temperature. Physical and mechanical characteristics of clay brick change depending on the content of FA added: shrinkage, density and compressive strength reduce, water absorption and total porosity increase. Clay bricks containing 2.5-5 % FA do not exceed the limit values of inert substances according to the Waste Directive 2003/33/EC. According to the test results and taking into consideration clay brick physical - mechanical characteristics and environmental toxicity, the recommended content of the addition to the moulding compound is 2.5-5 % FA.
The impact of expanded polystyrene waste of different fineness on the properties of lightweight composite
Authors: Leonavičius D , Pundienė I , Pranckevičienė J , Kligys M 
Published: December 2019

Abstract
Expanded polystyrene (EP) is widely used as a packaging material for many types of goods. However, once the material is used, it is disposed of in landfills, where it can remain intact for the lifetime of several generations. Recycling of disposed EP packaging is of high relevance worldwide. The main objective of this study is to make a more detailed research into the effect of EP aggregate waste of different fineness and shape on physical and mechanical properties of porous lightweight aggregates concrete (PLWAC) with EP waste aggregates. Tests were done with Portland cement, EP waste of different fractions, resulted from crushing (EPR) and cutting (EPU), metakaolin, superplasticizer and air entraining admixture. Six batches of PLWAC specimens were formed with different EPR/EPU ratios, ranging from 0.5 to 3.The change in EPR/EPU ratio in PLWAC leads to structural changes and density reduction from 550 to 410 kg/m3 after drying. When EPR/EPU ratio in the PLWAC is increased to 2, the compressive strength of the specimens drops from 2.3 to 1.75 MPa and down to 0.55 MPa, when EPR/EPU ratio is increased to 3.
Use of carrier materials to immobilise and supply cementation medium for microbially mediated self-healing of biocement
Authors: Spencer C A , Sass H 
Published: December 2019

Abstract
Microbially induced calcium carbonate precipitation (MICP) has been attracting growing interest in respect of its use for biocementation, as a means of improving the engineering properties of granular soil. Recent studies have demonstrated the potential of MICP to enable self-healing of biocement, through the injection of nutrients and precursor chemicals required for MICP into degraded biocement. This paper documents the early stages of research into the development of an autonomous self-healing system for biocement, whereby the nutrients and precursor chemicals are provided from within the biocement matrix. This system has the potential to improve the durability and sustainability of geotechnical structures. The effectiveness of a variety of carrier materials for the immobilisation and release of the nutrients and precursor chemicals, also referred to as the cementation medium, has been explored. Materials tested include expanded perlite, diatomaceous earth and natural fibres such as jute and coir. Studies have subsequently been undertaken to investigate the effect of these carrier materials on the MICP process, in aqueous solutions and within the biocement matrix, and thus the potential to enable self-healing. Ureolytic, spore forming Sporosarcina ureae has been utilised to induce the precipitation of calcium carbonate.