bluuebunny/crossref_metadata_2025_split huggingface dataset:
Designing Concrete with Self-healing Properties Using Engineered Cementitious Composites as a Model
Authors: Mircea A C , Toader T P 
Published: July 2020

Abstract
Engineered Cementitious Composites (ECC), also known as Strain Hardening Cement-based Composites, are an easily molded mortar-based composites reinforced with polymer fibers. ECCs are designed based on micromechanics and fracture mechanics theory, to feature large tensile ductility and a variety of unique properties, including tensile properties, superior to other fiber-reinforced composites. The properties of ECCs can be custom-tailored through micromechanics design due to the interaction between the fibers and cement matrix. A structural deterioration of ECC is avoided because the fibers do not allow cracks with large widths to form, unlike conventional concrete. ECCs have the capacity to bend, generating a flexible material. Ductile properties rather than brittle had increased, unlike ordinary concrete, leading to a wide variety of applications. Obtaining superior characteristics for ECC, both in fresh and hardened state, a transition from ECC paste to concrete with self-healing properties was made. To obtain self-healing concrete, with same ECC paste behavior and characteristics, the mix-design of the paste was optimized. The aim of this article is to present the experimental results regarding the transition from ECC paste to self-healing concrete and to analyze the results in order to establish a mix-design pattern for concrete with self-healing properties.
Influence of Primary Power Source on Heat-insulating Material Choice for Autonomous Telecom Unit Container
Authors: Kiseleva S , Tarasenko A , Fedotov A 
Published: July 2020

Abstract
The paper is devoted to the energy balance estimation for autonomous telecom unit, powering from photovoltaic panels and diesel-fuelled genset. Unit container has its own heat balance, basing on climate control system and parasite heating from telecom equipment inside it. Climate control system is also considered as power consumer from PV or genset. Obviously this power consumption depends on unit load graph, heat exchange with environment, environmental temperature. Energy and economical analysis has been conducted for several possible unit geographical locations, three types on heat-insulating materials and different share of solar energy in energy balance. It has been shown that in case of diesel fuel domination in energy balance and not very low environmental temperature heat-insulating material with lowest heat conductivity is not an optimal choice from operational expanses point of view (through high fuel consumption in summer for the container cooling).
Expanded Foam Glass - an Application for Fire Resistant Multilayer Materials
Authors: Mocanita O , Chicet D L , Rusu O , Istrate B , Munteanu C 
Published: July 2020

Abstract
This study is focused on obtaining a fire-resistant multilayer material, which includes in the structure a layer with properties of high temperature resistance and low heat transfer. One of the research directions is focused on obtaining such a layer using expanded glass granules with two different dimensional ranges noted with A (1 - 2 mm) and B (0.25 - 0.5 mm). The target layer was realized with the shape of square plates of 50 × 50 mm, with a thickness of 5 and 10 mm respectively, from a mixture of quartz sand with a polymeric resin as bonding agent in which the expanded glass granules were inserted. The following samples were obtained: P5A and P5B (5 mm thick plates), respectively P10A and P10B (10 mm thickness plates). The samples were analyzed both from the morphological point of view (the emphasis being placed on the structure distribution of the expanded glass granules) and from the point of view of the resistance to high temperatures (by indirect exposure at temperatures between 400 - 600 ° C for 3 hours). The satisfactory behavior of the samples during the tests recommends the extension of the researches in this direction, in order to establish the optimal percentage of component elements.
The Effect of H2O2 and Lactic Acid Addition in Biological Saliva on the Corrosion Behaviour of 304L Stainless Steel
Authors: Simionescu N , Benea L , Chiriac A 
Published: July 2020

Abstract
The aim of this study is to assess the corrosion resistance of SS304L in biological solution (named Ringer) at body temperature 370 C. The addition of H2O2 and C3H6O3 simulate the presence of microorganism metabolic product and inflammatory conditions. 304L stainless steel, in the oral cavity, can interact with other product capable of initiating corrosion of metals. H2O2 was used because is delivered by leukocytes and microscopic organism (bacteria) occurs in conditions in which the human body suffers a process of inflammation and lactic acid can be produced by a bacterial strain called Streptococcus mitis meeting in the dental plaque. For corrosion investigations was used in situ measurement (electrochemical) such as: OCP (open circuit potential) and EIS (electrochemical impedance spectroscopy). The electrochemical results conclude that the additions of hydrogen peroxide and lactic acid as well as these two compounds in combination have influence on the corrosion behaviour of SS304L in Ringer saliva.
Contributions to the Development of a Low-Speed Gadolinium Actuator System
Authors: Toader V E , Ungureanu C , Milici L D 
Published: July 2020

Abstract
Within the EMAD Research Centre of the USV, a low-speed actuator system has been developed which is based on the properties of the intelligent material gadolinium, i.e. the modification of the magnetic properties of the material according to temperature, magnetic at a temperature of less than 22.5 degrees and paramagnetic at a temperature greater than 22.5 degrees. The speed adjustment is made by the temperature variation (cold - warm). The paper presents the constructive solution, experimental data from which the characteristics of the equipment designed, carried out and tested and the general conclusions on its implementation in industrial actuator systems.
Influence of Microparticles on Setting Time and Micromorphology of Coal Ash Geopolymers
Authors: Burduhos Nergis D D , Vizureanu P , Țopa D , Minciuna M G , Abdullah M M A B 
Published: July 2020

Abstract
Geopolymers are inorganic materials with zeolites-like microstructure and mechanical properties similar to those of Ordinary Portland cement materials [1]. However, their properties are highly depending on the constituents (raw material and activator) characteristics, as well as, on the activation particularities (mixing parameters, curing time and temperature etc.). In order to explore the influence of partial replacement of coal ash with two types of fine aggregates (glass and sand microparticles) on micromorphology and setting time, four types of geopolymers were developed. The evaluations were performed by means of electronic microscopy and Vicat method. According to this study, the coal ash replacement with glass microparticles results in an increase in the initial and the final setting time, while the replacement of coal ash with sand particles show a significant decrease. Moreover, the microstructural analysis shows different behaviour, during activation, of the studied microparticles. The surface of the glass microparticles reacts in the alkaline environment, while the sand particles did not. Therefore, the increase of initial and final setting time can be correlated with the dissolution of Si-O from the glass particles, during geopolymerisation.
Temperature Deformation Influence on the Locking Equipment Destruction in Water Supply Systems at High-Rise Buildings Upper Floors
Authors: Antimonov A , Pushkareva N 
Published: July 2020

Abstract
The locking equipment in water supply systems destruction problem on the upper floors of high-rise buildings is being solved. After destruction products quality study did not reveal defects of a metallographic nature or rejects in manufacture. Therefore, the hypothesis that the destruction cause is low-cycle material fatigue under the dynamic loads influence, arising due to temperature deformations in the pipeline, was proposed. In this paper, we consider a pipeline scheme in which a temperature gradient arises in the fluid flow direction. At different temperature strains of the pipeline parts bending stresses emerge. These stresses cyclic nature is determined by the hot- and cold-water consumption frequency. The pipeline model where the locking equipment was installed is a beam with pinched ends. The bending stresses calculation for this beam was performed using the initial parameter method. Plots of moments and transverse forces in the beam section are plotted. The permissible stress calculation under the dynamic loads action was made. The pipeline section size, within which shut-off equipment can be installed without destruction, was determined.
Studies on Two Icons Oklads with the Representation of St. Great Martyr George
Authors: Bivol L R , Ghica V G , Petrescu M I , Iacob G , Vasile E , Buzatu M , Gheorghe D , Kovács T A 
Published: July 2020

Abstract
The work represents a comparative study of two icon oklads representing St. George killing the dragon: the first of Romanian origin according to the stamp with the silver title “12” - examples of Romanian oklads with this silver title can be found in the works of S.S. Duicu, and the second oklad with stamps that seem to be specific to Russian silverware workshops. The Romanian icon oklad depicting St. George killing the dragon has in the central-lower part two stamps - the first stamp represent the monogram of master controller or craftsman or silver master “KΠ”, and the second represents the silver title “12”. The initials of the master are written in Cyrillic letters, as well as the inscription from the upper part of the oklad “C.ΓEOPΓIE”. The investigations on the two icons oklads were achieved through XRF analysis performed with a portable X-MET 5000 Oxford analyzer (Oxford X-MET 5000 Handheld XRF Analyzer) and SEM-EDX analyzes performed on a Phillips XL-30-ESEM electron microscope using a Quanta Inspect F50, with a field emission gun (FEG) with 1.2 nm resolution and an Energy Dispersive X-ray Spectrometer (EDXS) having 133 eV resolution at MnKa. Following the analyses it was observed that the silver title 84 stamped on the Russian icon oklad does not correspond to reality.
Instrumental Analytical Techniques Applied to Old Gate Tower from Corvins’ Castle
Authors: Ion R M , Tincu S , Minca I , Dulama I D , Bucurica I A , Ion M L , Gheboianu A I 
Published: July 2020

Abstract
Nowadays, a better understanding of the factors (including environmental) that influence the degradation of materials from different buildings and monuments, is absolutely necessary. In this paper some analytical techniques, as Fourier Transformed IR Spectroscopy (FTIR), X-ray diffraction (XRD), X-ray fluorescence (XRF), optical microscopy (OM) and SEM-EDS, have been used for evaluation the structure and chemical composition and the characterization of the degradation products, causes and mechanisms of disintegration / degradation of materials and aging processes. Few samples from the Old Gate Tower of the Corvins’Castle, Hunedoara, have been collected and subjected to be analysed and fruitful conclusions have been obtained referring to the raw materials provenance and weathering / deterioration processes which they supported. Similar minerals with those identified at the other towers from Corvins’Castle have been evidenced: quartz, calcite and dolomite, being majority, and additional apatite minerals. Also, ion chromatography could be used to identify the presence of different ions, responsible for the accelerated process of the monument’s walls.
On the Security of a Smart City SDN-Based Network
Authors: Scripcariu L , Mӑtӑsaru P D , Mocanu F 
Published: July 2020

Abstract
Our research work focuses on the security techniques applied on a software-defined network (SDN), designed for a smart city. Information security is essential for the good functionality of the applications used in a smart city. Information should be correct and complete otherwise the ‘life’ of the city can be compromised by various cyberattacks targeting, for example, the public transportation system, the traffic information on highways or location services for emergency crews and many others. Securing all devices connected to the SDN, including end-user devices, wireless sensors, smart home equipment is essential because various cyberattacks may be launched and the smart city may be disturbed. This paper presents a risk analysis, the ways to choose the security solutions according to the smart city security policy and our proposal for the SDN security system. We compare different security techniques and present some recommended solutions.
Considerations Regarding the Recalibration of the Manufacture of Castings from the Perspective of the Development of the Circular Economy
Authors: Soporan V F , Vescan M M , Lehene T R , Pӑduretu S , Gabor T 
Published: July 2020

Abstract
The paper presents the issue of recalibration of cast parts from the perspective of the circular economy, by presenting the specific issue, by setting the main objective of the study, that of identifying areas that require interventions in the technological process and ensuring socio-economic functionality. The analysis, in general, includes the presentation of the specifics of the analyzed process, the construction of assessment indicators of the circular economy and the quantification and hierarchy of the influencing factors. Particular attention is paid to the quantitative indicators and value appreciation of the manufacture of castings to the rigors of the circular economy. At the level of interpretive analysis, are presented the critical areas that require a multidisciplinary intervention to ensure the specific conditionalities of the circular economy.
Innovation for Trap Particle and Eliminate Germs in Air By Corona Electrostatic System
Authors: Ketkaew S 
Published: July 2020

Abstract
This article presents an innovation for trap particle and eliminate germs in air by corona electrostatic system. The air circulation rate is 165 cubic meters per hour by designing the power supply with IC#TL494. The IC#TLP250 uses separate ground and drive Power MOSFET#IRFP460 by bringing DC high voltage from the transformer#TLF14511 to the dust collector unit and the electron separation unit. By designing and building a machine capable of trapping dust particles smaller in size from 0.3 microns up to the results of the tests showed that the dust collecting efficiency of 95.37% from the experiment by measuring the amount of dust using Personal pump and the dust collection efficiency of 95.86% from measuring dust using Handy laser partical counter and part of electron separation can produce corona for producing ozone gas up to 3 ppm to eliminate bacteria in the air. The UV lamps for ozone emissions are reduced to 0.1 ppm for disaster prevention to users.
Cellulosic and Tannins Containing Wastewater Treatment Using MBBR Technology and Fungal Strain
Authors: Moga I C , Iordache O G , Petrescu G , Mitran E C , Tanasa A G , Sandulache I , Pantazi G A , Secareanu L O , Anghelache G , Lite C 
Published: July 2020

Abstract
Since the beginning, Mobile Bed Biofilm Reactor (MBBR) technology has been extensively used, both at the level of small on-site treatment units and at industrial scale. Moreover, this technology represents a starting point for many researches aimed at improving performance, such as the use of microorganisms, enrichment with anammox bacteria to accelerate nitrogen removal and more. Within the present paper, a new generation of carriers (consisting of a mix of high-density polyethylene + talcum + cellulose) was bio-augmented with a WRF (White Rot Fungi) strain, namely Cerioporus squamosus, in static conditions (data not shown in this paper). The wastewater, targeted for treatment, originated from National R&D Institute for Textile and Leather, INCDTP Bucharest, leather subsidiary, Leather and Footwear Research Institute, technological flux, characterized by high tannins concentration, and cellulosic content. Wastewater treatment aimed the reduction of COD value, as a water quality parameter, with satisfactory results, obtaining a percentage reduction rate of 48.53%. Also, GC-MS chromatography analysis was carried out on five vegetal tannins, used in leather treatment, highlighting main compounds for Mimosa, Chestnut, Gambier, Myrobalan and Quebracho natural tannins.
Comparison of Total Phenolic Content, Antioxidant Activity and Extraction Yield from Apium Graveolens Waste Using Unconventional Extraction Methods
Authors: Spînu S , Orţan A , Ionescu D , Moraru I , Drugulescu M 
Published: July 2020

Abstract
Apium graveolens is a medicinal and aromatic plant used in pharmaceutical industry, cosmetic industry, gastronomy and traditional medicine. Aerial parts of Apium graveolens (stems and leaves) are rich in bioactive compounds (flavonoids, phenols, furanocoumarins, volatile oils, sesquiterpene alcohols, fatty acids, etc.). It is known for its hepatoprotective, antioxidant, anticancer, antidiabetic, anti-inflammatory, antimicrobial, analgesic, anti-spasmolytic, anti-infertility, cardiotonic activities. This is why studies in this direction have not yet ceased and are increasingly pursuing the discovery of new, unconventional methods for identifying, quantifying and isolating bioactive compounds from Apium graveolens waste. The aim of this study was to determine and correlate the total phenolics, total flavonoids, antioxidant activity and extraction yield from ethanolic extracts (70%) of stems and leaves waste with different unconventional extraction methods. Apium graveolens aerial parts waste were obtained after aqueous extraction of the leaves and stems. The extraction yield was expressed as function of freeze-dried extracts, and the extraction methods were ultrasound assisted extraction, microwave assisted extraction and accelerated solvent extraction. Regarding the chosen extraction methods, numerous studies have shown, especially in the case of microwave assisted extraction, the presence of bioactive compounds in plant waste, in a reasonable percentage, therefore this study aimed to identify an optimal extraction method also in the case of Apium graveolens aerial parts waste. Total phenols content was determined by Folin-Ciocalteu spectrophotometric method, the flavonoids content waste determined by aluminium chloride spectrophotometric method and the antioxidant activity was studied using DPPH (2,2-Diphenyl-1-picrylhydrazyl) spectrophotometric method. The findings of this work indicated a positive dependence between the extraction yield of the waste material and the considerable content of bioactive compounds still present (phenols and flavonoids) for all considered extraction methods.
Reducing Power Consumption in Smart Monitoring Systems with BLE Wireless Technology
Authors: Ştoica C , Mӑtӑsaru P D , Scripcariu L 
Published: July 2020

Abstract
This research focuses on alternative low power consumption in smart monitoring systems and on various techniques to facilitate access to different monitoring sensors connected via Bluetooth Low Energy (BLE). Due to high complexity and power demands that new smart monitoring equipment have, the need for reduced power consumption in the context of new regulations/architectures for the Internet of Things has occurred. Sensors can have dimensions of a few centimeters, are not required to have cabling or power supply and can transmit data for a long period of time. A network of sensors connected through BLE wireless technology with a corresponding architecture can provide a simple and versatile solution to multiple environments that need to be monitored. Data provided by the smart monitoring systems must be carried and analyzed either in upper layers of the network or close to the edge. Dedicated applications allow users to access data via smart-devices and data can be downloaded on any device, such as mobile phones. All these require communication technologies with optimized and reduced power consumption, also increasing battery lifetime and becoming more eco-friendly.
Simulation of Pedestrian Walking Through Angled-Corridors for Evacuation Behaviour Study
Authors: Rahman N A , Alias N A , Sukor N S A , Halim H , Gotoh H , Hassan F H 
Published: July 2020

Abstract
The effect of acute- and obtuse-angled-corridors on the evacuation behaviour is rarely studied. In the previous work, we have confirmed that corridor with less than 90° turning angle has negative impact to the pedestrians walking behaviour due to the tendency of the pedestrians to slow down their motion when approaching the turning of the corridor. This restrict the flow of walkers during high-density situation and cause congestion near that turning of the corridor. In this contribution, empirical data collected from previous experimental work is utilised to further study the effect of turning angle on the evacuation behaviour. The simulations of walking through angled-corridor were reproduced which reflects evacuation scenarios. Three different types of angled-corridor are taken into consideration (a 60°-, a 90°-, and a 135°-angled-corridors) with different sets of number of pedestrians (NOP: 60, 70, 80, 90 and 100). Three metrics of evacuation behaviour measurement are reported: (1) inflexion points, (2) escape time, and (3) interaction force. Inflexion point is used to evaluate the restriction flow occurred during the evacuation. From the results, the 60° angled-corridor contained the highest number of inflexion points. With the highest number of inflexion points, the escape time for the 60° angled-corridor is 14.8% to 24% longer compared to the other two types of angled-corridors. This shows that this kind of angled-corridor need to be avoided in the future design of walkways. On top of that, the 60° angled-corridor also gives the maximum interaction force with 213.75 N. This reconfirmed that the corridor with less than 90° turning angle is not suitable to be built as a walkway. This work is relevant to be studied due to its immediate applications in assessment of crowd safety for building egress.
Polyester Dyeing and its Environmental Impact
Authors: Manea L R , Bertea A-P , Bertea A 
Published: July 2020

Abstract
Dyeing and printing of textiles are responsible for 30% of the pollutants contained in the effluents. The impact of textile dyeing processes on environment is highly variable, most important issues being the colour, the organic charge, and the solids in suspension. The present study investigates the characteristics of the polyester dyeing process in what concerns the environmental issues. Disperse dyes are non ionic, have very limited solubility in water at room temperature and have substantivity for polyester fibre. Two disperse dyes were used, and dyeing were performed at different concentrations. The exhaustion degree, the volume of wastewater used in the process, the specific flow, pH, temperature and chemical oxygen demand of the wastewater, the total residuum, volatile substances and the biological oxygen demand were determined in all the cases. The data obtained showed that the global pollutant content of the wastewater from disperse dyes dyeing is high (more than two times higher than those obtained in the case of dyeing with acid dyes). Absorption spectra of the initial and exhausted dyebath were determined, in order to evaluate the dilution degree needed to make wastewater colour acceptable.