bluuebunny/crossref_metadata_2025 huggingface dataset:
Engineering exterior translucent coatings with the use of profile glass and composite materials
Authors: Abramyan S G , Polyakov V G , Oganesyan O V
Published: December 2019

The paper raises certain questions concerning the use of structural glass (glazing) in external vertical enclosures of modern construction systems, pointing to the need for combining composite materials, especially composite foam, in translucent enclosures, which helps dramatically reduce the weight of external panels while improving their heat and sound insulation performance. It also emphasizes the relevance of energy efficiency at the building operation and building construction stages, as energy efficiency is not only the heat saving performance during building operation, but also a high effectiveness of the construction technology.

The novelty of the study lies in engineering a wall panel possibly combining two materials — profiled glass and composite foam. The paper not only details the panel design, but also describes the manufacturing technology and the envelope arranging processes with two wall panel attachment methods and related joint assemblies. Based on a number of scientific publications, the handling mechanisms are discussed suitable for different ways of coupling the structural elements — wall panel and floor slab. Focusing on box-type structural glazing, the authors stress the need for further study involving other types of structural glass (channel shaped, ribbed, trimmed) to create multicomponent wall panels for a variety of regional climate conditions.
Organizational and economic problems of ecological safety in construction
Authors: Azarov V N , Manzhilevskaya S E , Petrenko L K
Published: December 2019

Nowadays it is necessary to make the environmental impact assessment (EIA) in order to identify, analyze and take into account the direct and indirect effects of environmental impact during the planning of design consideration for construction projects. The results of this assessment determine the aftereffects of a certain construction project’s implementation. These results are the objective information about the future state of the environment of the territory for making decisions on the implementation of the planned project.

The economic component of this assessment is the determination of the cost of implementing measures to protect the environment of a given territory. Current design trends have a tendency to change the criteria for planning the construction projects. It is important to make the managerial, technical and commercial decisions during the project development in favor of the environmental safety of the construction industry. During the criteria of the assessment development, it is necessary to take into account the prevention measures. It is important to prevent the pollution but not to monitor and eliminate the negative effects.

This article considers an example of the calculation of the criterion for choosing the environmental pollution control measures which can reduce the construction cost. These calculations make it possible to determine the environmentally and economically suitable area for the construction of an object in the populated area.
The concept of sustainable development of renewable energy in the modern world
Authors: Sheina S G , Pirozhnikova A P , Priss E A
Published: December 2019

The article is devoted to the concept of sustainable development of renewable energy in the modern world. The concept of sustainable development of world energy is considered. The analysis of the current state of the fuel and energy complex is given. The principles of development and goals of the future sustainable world energy are given. The essence of sustainable energy development, environmental problems of the leading countries in the production of electricity is being considered.
Program-target approach as a basis for issuing a backlog in construction
Authors: Zilberova I Yu , Tomashuk E A , Bobkina V A
Published: December 2019

During the last decades, the problem of maintaining the level of the housing stock was solved by the residual principle. The low quality of housing due to the use of short-lived materials and projects not reflecting the real objects’ state has led to accelerated rates of physical and moral deterioration of buildings. Implementation of the overhaul program is one of the priorities, but despite its significance, a number of problems of its implementation have been identified. The planning methods currently used do not properly reflect the changes taking place. The article proposes one of the possible solutions to the difficulties arisen, namely, the formation of a backlog on the program-target approach basis. Construction companies must diversify their backlog taking into account the existing workload and the lot structure determined by the customer.
The study of the secondary dust resuspending in industrial premises
Authors: Stefanenko I , Zhukova N , Boguslavskij N , Azarov A
Published: December 2019

The article is devoted to the sedimentation study and settled dust subsequent resuspending. An assessment of the dust distribution patterns, knocked out of the process equipment by the method of Azarov-Boguslavsky. A mathematical model description of the dust resuspending process is proposed.
A combination machine for industrial wastewater purification
Authors: Moskvichova A V , Ignatkina D O , Moskvichova E V , Lebedev D N
Published: December 2019

The statistic information about the amount of discharge of pollutants into water sources in Russia is studied. Also, the main problems of wastewater purification are discussed. According to the literature survey, the perspective directions in wastewater purification, as a result of the manufacturing activity of the food industry enterprise, are brought out here. It is offered to choose an electrochemical treatment as a basic stage of wastewater purification. And finally they offered to use a sorption final treatment. A machine called an electrolyzer-adsorber which was made by the authors is presented and described. The main technological parameters, which influences on the level and power-intensity of the electrochemical sorption purification happening in the machine are listed. The results of the experimental researches in choosing the optimum parameters in the wastewater purification machine called the electrolyzer- adsorber were studied at the one of the Volgograd food industry enterprise.
Experience non-destructive testing of the metal of bridge structures
Authors: Beskopylny A N , Vernezi N L , Veremeenko A A , Arakelyan R M
Published: December 2019

The paper described the history of the use of materials in the construction of bridges, the examples of the significant disasters associated with the destruction of bridges in various countries. The problems that inevitably arise during the inspection of bridges and assessment of their bearing capacity are considered. The requirements for monitoring of the strength characteristics are given. The list of controlled characteristics is presented. A non-destructive method for determining these mechanical characteristics by impact pressing the conical indenter is considered. The analysis of the characteristics of the railway bridges in the city of Belaya Kalitva and Novocherkassk was made. These characteristics were compared with the properties of the metals used in construction in different years. The statistical analysis of the obtained data was made.
High-tech innovative robotized systems efficiency use in construction
Authors: Ospishchev P I
Published: December 2019

The article discusses the practical features of the promising use of 3D construction printers that print cement-based mixtures, like robotic systems. A construction robotized systems main categories brief description is given, as well as the technological aspects of their application are considered. The technical and economic efficiency of the building 3D-printers and printing mixtures on a cement basis use is analyzed.
Mathematical modeling of deformation of pre-stressed steel trusses taking into consideration the possibility of emergencies
Authors: Serpik I N , Tarasova N V
Published: December 2019

An algorithm of finite-element modeling has been developed in a geometrically non-linear setting of steel plane trusses which are pre-stressed using high strength cables, in the event of emergency in the form of single cable breakage. The application of framework gravity forces, consecutive introduction of tie bars and their pre-stressing, application of running load and emergency impact have all been monitored. Herewith, the condition of static loading using the dynamic relaxation method has been simulated. A factor taken into consideration is non-linearity associated with the inclusion of new cables into the framework, analysing the possibility of their behaviour strictly under tension, and removal of a cable from the loading system in the event of its breakage. The problem has been solved using numerical integration based on the development of the Newmark method via deriving equations of equilibrium of a discretised structure in the deformation state during each step of integration. The operability of the suggested algorithm is illustrated by the example of a steel truss with a span of 60 m, including two cables. The dynamic behaviour of an object is considered at a sudden breakage of the pre-stressed cable.
Mathematical modeling of hydraulic structures gates
Authors: Kozinets G
Published: December 2019

The article deals with the numerical simulation of gates with the optimization of the design. The geometric model of the segment gate is given. The description of structural elements is executed. The normative requirements of strength for the metal structure of the gate are fulfilled. The results are presented in the form of reduced stress and strain fields.
Search for Cold Bridges Based on the Building Information Model Collisions Analysis
Authors: Ignatova E V
Published: December 2019

The energy-efficient buildings construction requires careful consideration of the building external structures heat loss possible causes. One of the reasons for heat loss is the cold bridges presence in the building external circuit. This article discusses the material cold bridges causes, i.e. energy leakage through more conductive materials. Some analysis methods of cold bridges and possible methods of their elimination are considered. The main attention is paid to the automated search for cold bridges at the building design stage using BIM technologies. It is proposed to analyze the building information model data, using the geometric objects finding collisions method. The algorithm includes the building elements determination that crosses the building thermal contour and such elements materials analysis for their ability to heat transfer. The advantages and limitations of the proposed method are discussed.
Requirements for the avalanche protection catching and deflecting dams design in Russia and the European Union
Authors: Adzhiev A , Bekkiev M , Bolgov Yu
Published: December 2019

The requirements for the avalanche structures (catching and deflecting dams) design used in the Russian Federation are considered in the article. The comparative analysis with similar requirements in the European Union is conducted.
Analysis of power characteristics in the elements of the active Dead-End stop based on the double wedge system
Authors: Demianov A A , Demianov A A , Donchenko A V , Pavlitskiy B I
Published: December 2019

The dead-end stops that are installed at the truck ends and differ from each other in their design and principle of repayment of the kinetic energy of a moving object are used to improve the operation security of the rail lift and transport facilities. However, the main task of any dead-end stop is to stop the lift and transport facility at the minimum braking distance. Inadequate braking “smoothness” can cause a derailment or destruction of the lift and transport facility, so it is preferable to use dead-end stops excluding the impact during the braking and ensuring a smooth increase of the braking effect. The dead-end stop construction with the effect of increasing resistance forces is proposed, which meets these conditions, that can be used both for lift and transport facilities and for the rail rolling stock. In addition, the analysis of power characteristics in the spot elements was made and analytical dependencies for engineering calculations were developed.
The steel defects investigation by the Eddy current method
Authors: Dmitriev S , Malikov V , Ishkov A
Published: December 2019

The paper describes the gage system designed for the various properties materials study. Within the study frameworks, the sections of pipes made of a new material — high-strength steel 08G2B of K65 steel grade were studied. These materials are ultra-low-carbon steels, wherefore it is possible to study their properties using the eddy current method. A subminiature eddy current transducer consisting of three windings on a core made of 81NMA alloy was used during the study. The resulting parameter of the gage system, which contains information on the object under study, was the change in the eddy current transducer signal. In this study, the samples with continuity defect models — cracks and holes — were investigated, and a study was conducted to simulate the corrosion presence in the metal.
Simulation Network-Level Relationships of Traffic Flow
Authors: Zyryanov V
Published: December 2019

The paper considers capabilities of the macroscopic fundamental diagram of traffic flow to predict the conditions of operation of the road network in urban areas. This study examines relationships of traffic flow parameters on the network level. Microscopic traffic simulation has provided important data on the estimation of road capacity, velocity, trip time, and detection of congestions reasons. Data of spatial distribution density in network useful for implementing approach based on gating policy on subnetwork using MFD. It presents the results of a simulation using the example of central area of Rostov-on-Don.
Protection of unmanned vehicles from component failures
Authors: Moroz Sergey
Published: December 2019

For the transfer of road transport to unmanned driving, it is necessary to create not only technologies for automatic control of the movement of vehicles, but also technical measures to protect them from failures of components of unmanned vehicles. Such protection will ensure the development of monitoring the performance and operational properties of unmanned vehicles in combination with algorithms for the use of its results. The purpose of this work is to substantiate the methods of automation of control parameters of performance of unmanned vehicles and the construction of protective control algorithms of unmanned vehicles in the interests of technical operation. A new method of automatic control of parameters dependent on the technical condition, modes and operating conditions of vehicles is proposed. It is based on the simultaneous control of the parameters of the technical condition, mode and operating conditions of the tested component, the division of the ranges of possible changes in the parameters of the mode and conditions at narrow intervals, the formation of possible combinations of the intervals obtained and registration of the standards of the estimated parameter for each combination of intervals at the beginning of operation of an unmanned vehicle. The proposed method is intended for the implementation of the onboard local network of an unmanned vehicle.
Integrated information system for improving strategic management of urban system
Authors: Bulychev Lev , Larinina Tatyana , Lukinov Vitaly
Published: December 2019

The paper studies the current problems in the development and implementation of innovative strategies for the development of municipal infrastructure of the city through the creation of mechanisms to support the management intellectualization in the industry. Intelligent monitoring of housing and communal complex will allow improvement of the system of management of territories and ensuring the timely adoption of adequate administrative decisions on coordination of economic actors forming the social and production infrastructure of municipalities. The most promising direction in this field is geographic information systems.
Calibration of the prediction model for fatigue damage accumulation in asphalt courses of flexible pavements for the conditions specific to the Russian Federation
Authors: Uglova E V , Tiraturjan A N , Eganyan G V
Published: December 2019

The article dwells on the asphalt pavements fatigue life matter. The authors suggest a fatigue damage prediction technique based on the NCHRP modified model and the MMOPP model of structural deterioration of asphalt courses. The research resulted in the fatigue cracking main algorithms verification and calibration performance prediction based on the analysis of actual conditions of the M4 Don Highway pavement which makes it possible to significantly improve the prediction results reliability for the conditions specific to the Russian Federation.
Improving the quality of low-rise housing construction projects
Authors: Tsopa N V , Malakhova V V , Kovalskaya L S
Published: December 2019

The main priority of the social and economic policy in Russian Federation is to solve the housing problem. The national project “Affordable and Comfortable Housing for the Citizens of Russia” is an important form of implementation the modern housing policy. The expansion of low-rise buildings is influenced by the housing policy. Existing methods for assessing the quality of low-rise building projects require further development. The issues of improving the quality of low-rise building projects require further system improvement of quality assessment indicators too. Quality assessment takes into account indicators of safety, comfort and resource saving. Mechanism for improving the quality of low-rise building projects is proposed in this paper.

The basis of this mechanism is a system of indicators for assessing the projects quality at the predesign stage. Approbation of the proposed mechanism was made using the example of the construction of Izumrudny cottage complex in Gorny village, Yalta.
Method of cost efficiency analysis for solar batteries installation using intensity of solar radiation
Authors: Kuzovleva I A , Blagoder T P , Kuleshova V I
Published: December 2019

Article systematically considers the main aspects of the cost efficiency field of innovative projects introducing solar radiation as an alternative energy source. The article offers a proprietary methodology of cost efficiency analysis for solar panels installation using the intensity of solar radiation (insolation). The calculations carried out using this method determined the amount of annual economic benefit of installing innovative solar panels.
Methodological aspects of providing balanced innovative development of construction complex of the Russian Federation
Authors: Geraskina I N , Kuligin K N
Published: December 2019

The growth of significance of economy’s innovative development of the Russian Federation determines necessity of deeper investigation of properties and specific features of its subsystems functioning, contents and forms of interaction thereof, seeking ways of increasing efficiency of control system. The construction complex (hereinafter referred to as the CC) as a priority area of the national economy, actively influences it and largely determines the trend of functioning, as well as the quality of life of the population. Construction, acting as the locomotive of the socio-economic development of the country and having a high cumulative potential, is associated with almost all industries and related fields of economic activity. Despite the fact that investment and construction activity makes a significant contribution to the growth of macroeconomic indicators of the Russian Federation, it is studied without a detailed understanding of the immanent properties and patterns of development as a complex self-regulating system. The strategic benchmarks for the development of the CC are structured by the demands of consumers not only in a safe, but also comfortable living environment with high environmental characteristics and aesthetic requirements. Meeting such requirements is possible under the condition of large-scale modernization of the construction sector with the use of breakthrough scientific and technical solutions in all segments of human activity. All this gives grounds for concluding that a fundamental change in the approach to the study of properties, features and factors of the development of the CC is necessary, which provokes the modernization of the management system to ensure a balanced innovation trend and high standards of quality of life of the population. Important factors in the development of the CC are fair competition, freedom of economic activity, the development of market mechanisms, corporate culture and moral values. The study of the functioning and scientific approaches to ensuring a balanced innovative development of the CC of the Russian Federation made it possible to form a conceptual vision and methodological basis taking into account the main provisions of the theories of systems, self-organization and synergetics and to briefly present it in this work.
Methodology for assessment of repair and restoring potential of real estate
Authors: Avilova I P , Naumov A E , Ursu I V , Abakumov R G
Published: December 2019

Buildings and structures, as complex technological objects ensuring the effective functioning of a number the urban development environment social processes, need periodically technical updating, conceptually viewed from the standpoint of expedient reconstruction. The respective budgets rational strategic and operational planning issues directed to the immovable complexes’ reconstruction should be considered from the standpoint of both technical and town-planning expediency of reconstruction determined by a number of the object key indicators of reconstruction forming its urban-planning reconstruction potential. Particularly acute is the reconstruction rationality quantitative assessment question when implementing the investment programs financed by municipal and federal budgets, in which the integrated reconstruction of the territory is most effective. The reconstruction resource intensity is made up of the territory individual objects local resources - interrelated territorial functions carriers. The methodological approaches and algorithms for constructing a quantitative assessment of the property repair and restoration potential can be an effective complement to methods of dynamic analysis and the urban planning potential effectiveness evaluation of the actively developed territories. The paper demonstrated the practical use examples of the proposed methodologies, proposed methodological approaches to their integration into practical software industry.
The organizational-technological decisions acceptance support system in the investment and construction projects management
Authors: Zelentsov L B , Mayilyan L D , Hakobyan N G , Pirko D V
Published: December 2019

The article discusses the problems of making organizational and technological decisions in the investment and construction projects (ICP) management using intelligent construction management systems (“IMS Construction”).

The relevance of the study is due to the fact that in economic instability conditions in the Russian Federation, the construction organizations need to increase the organizational and technological decisions efficiency in order to reduce production costs.

The ISU “Construction” introduction allows the managerial decision-making of two independent areas integration in the implementation of ICP, based on the rules and precedents related to the methods of generating new knowledge, which allows to get a new impetus in the intelligent control systems development.

The greatest interest in using the proposed methodology formalized in the IMS “Construction” development is the possibility of accumulating knowledge about the ICP control system possible behavior, which is more likely to predict the right decision adoption in the event of any situations that have not been previously met or recognized.
Theoretical and experimental studies of dust in jobs in concrete production
Authors: Evtushenko A I
Published: December 2019

The article discusses and analyzes well-known scientific approaches to assessing the dust content of jobs at enterprises in the construction industry in the production of concrete. Boundaries are defined for the description of the log-normal distribution of particles and the probabilistic – stochastic approach to the description. The author presents the results of experimental studies at factories and enterprises for the production of ready-mixed concrete, reinforced concrete structures and products. The research direction is determined, recommendations are given.
Investigation of the dynamic variability in the amount of contaminants in urbanized atmosphere
Authors: Menzelintseva Nadezhda , Karapuzova Natalia , Laktiushin Vadim , Bogomolov Sergey
Published: December 2019

The dynamic variability in the amount of contaminants in urban atmosphere and the mathematical models which allow describing the given variability have been analyzed. The models of the seasonal variation in the amount of solid particles in the atmosphere of Volgograd were developed based on Fourier series. The seasonal index was determined. A dynamic equation characterizing the seasonal variability in the amount of solid particles in the atmosphere of Volgograd was obtained applying the method of analytical seasonal adjustment.
Synthesis and charactherization of TiO2 doped SnO2 thin film prepared by sol-gel method
Authors: Halin Dewi Suriyani Che , Razak Kamrosni Abdul , Azani Azliza , Abdullah Mohd Mustafa Al Bakri , Salleh Mohd Arif Anuar Mohd , Mahmed Norsuria , Shafee Nur Syahirah , Ramli Muhammad Mahyiddin , Azhari Ayu Wazira , Chobpattana Varistha
Published: December 2019

In this work, preparation of titanium dioxide doped with tin oxide, SnO2/TiO2 thin films deposited onto silicon wafer via sol-gel method. Different amount of SnO2 was added (5 ml, 10ml and 15 ml) into parent solution. The obtained films were annealed at different temperature which is 400°C, 500°C and 600°C for 1 hour. Morphological and surface topography of the SnO2 doped TiO2 thin films were studied using Scanning Electron Microscope (SEM) and Atomic Force Microscope (AFM). The annealed films shows non-uniform crack due to the mismatch of coefficient of thermal expansion (CTE) between SnO2/TiO2 thin films and silicon wafer.
Microstructural studies of doped PEG Ag/TiO2 thin film
Authors: Razak Kamrosni Abdul , Halin Dewi Suriyani Che , Azani Azliza , Abdullah Mohd Mustafa Al Bakri , Salleh Mohd Arif Anuar Mohd , Mahmed Norsuria , Chobpattana Varistha , Azhari Ayu Wazira
Published: December 2019

Ag/TiO2 thin film was prepared by the sol-gel method through the hydrolysis of titanium tetraisopropoxide and silver nitrate solution. Various amount of PEG was doped into the solution preparation to study the effect on crystalline state and microstructural of the prepared thin films. Spin coating method was used to get uniform film on ITO glass substrate followed by annealing process for 1 hour. The obtained thin films were analysed using XRD test, SEM and AFM. Results showed that all the prepared thin films are in anatase TiO2 Increasing the PEG amount into the solution could increase the thickness and surface roughness of the obtained thin films.
Influence of cooling conditions on the interfacial Cu6Sn5 intermetallic compound in Sn-37Pb/Cu solder joints during reflow
Authors: Somidin Flora , McDonald Stuart , Akaiwa Tetsuya , Nishimura Tetsuro , Nogita Kazuhiro
Published: December 2019

Despite a shift to Pb-free solders in the majority of electronic assemblies, Pb-containing solders are still used in a variety of applications. Recent research has revealed the complexities of the intermetallic Cu6Sn5 in terms of its crystal structure and stability when present as the reaction product between Pb-free solders and common substrates. In light of these findings, the effect of multiple reflow cycles with different cooling conditions on the microstructure of the interfacial Cu6Sn5 intermetallic compound (IMC) between Sn-Pb solders and Cu substrates was re- examined. For this purpose, the Sn-37Pb (in wt.%) solder was reflowed on a Cu substrate at a temperature of around 240 °C and cooled at a rate of around 30 °C/min under each of two conditions; (i) direct-cooling to room temperature, and (ii) interrupted-cooling with extended isothermal holding periods of 30 and 180 seconds at 140 °C. This second condition was chosen to encourage the polymorphic transformation that occurs in the Cu6Sn5 (at an equilibrium temperature of 186 °C) at a temperature which minimises the stresses involved. Smaller cracks and a thinner interfacial IMC layer were observed in the solder joints that were reflowed repeatedly with the interrupted-cooling conditions. However, despite the higher number of cracks in the samples undergoing conventional reflow, the shear strength was not significantly affected.
Effect of Zn addition on Cu3Sn formation in Sn-10Cu alloys
Authors: Mehreen Syeda U. , Nogita Kazuhiro , McDonald Stuart , StJohn David
Published: December 2019

Sn-Cu alloys have generated interest as potential candidates for high-temperature soldering applications, as they are economically feasible and environmentally safe. Sn-Cu alloys with copper contents beyond 7.6wt.% solidify with a primary Cu3Sn phase, followed by peritectic and eutectic reactions. Typically, phases which form as elongated needles are undesirable, as they tend to be more brittle and in turn reduce the strength and toughness of the alloy. The effect of Zn on the peritectic reaction and phase formation in a Sn-10wt.%Cu alloy is investigated through cooling curves and microstructural analysis using optical and electron microscopy. Zn was alloyed in the range of 0.1-1wt.% to the base Sn-10Cu alloy system. The results indicate that the amount of the primary Cu3Sn phase that forms is inversely proportional to the concentration of Zn. Although complete suppression of Cu3Sn was not observed, there was a clear effect of Zn reducing the amount of the primary Cu3Sn phase, with the greatest reduction of Cu3Sn occurring with a 1wt.% Zn addition. The reduction of the elongated needle-shaped primary Cu3Sn phase may find application in the development of more reliable bulk solder microstructures.
The influence of graphite on conductivity, crystallinity and tensile properties of hydroxyethyl cellulose (hec) / graphite composite films
Authors: Hanif Mohd Pisal Mohd , Jalilah Abd. Jalil , Badrul Farah , Nuraqmar Syed Mahamud Syarifah
Published: December 2019

Conductive films based on natural polymers may find potential in food packaging and biomedical applications owing to their advantages of biodegradability and biocompatibility. This work demonstrated conductive composite films from hydroxyethyl cellulose (HEC) incorporated with graphite prepared by solution casting. Fourier Transform Infrared (FTIR) spectra confirmed the absence of covalent bond between the HEC matrix and graphite. The electrical conductivity of the composite films with various concentrations of graphite was investigated by a four-point probe. We observed that the conductivity of the HEC film increased remarkably from 10−8 S/cm to 10−5 S/cm upon addition of graphite. The highest conductivity of 9.44 x 10−5 S/cm to 10−5 S/cm upon addition of graphite. The highest conductivity of 9.44 x 10−5 S/cm was obtained for the film with 30 wt% of filler and further addition of filler reduced the conductivity. The correlation between conductivity and crystallinity was elucidated by X-ray diffraction (XRD) patterns. The difference in d-spacing values between HEC and HEC/Graphite films and the decrement of crystallinity percentage suggest that the rearrangement of ordered HEC crystalline structure was perturbed by the filler resulting in reduction of crystallinity phase. The tensile properties results clearly show that the incorporation of graphite into HEC films has reduced the tensile strength which is in agreement with the obtained electrical conductivity and crystallinity percentage.
Effect of solution concentration and applied voltage on electrospun polyacrylonitrile fibers
Authors: Bakar Sharifah Shahnaz Syed , Foong Kar Mun , Halif Norzilah Abdul , Yahud Shuhaida
Published: December 2019

Electrospinning is a simple and convenient method for fabrication of polymeric nanofibers from polymeric solution. In this paper, polyacrylonitrile (PAN) fibers are fabricated from different PAN solution concentration and applied voltages by electrospinning process. The fibers were then analyzed with Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and four-point probe to study the effect of PAN solution concentration and applied voltage on electrospun PAN fibers in terms of fiber diameters and morphologies, crystallinity and electrical properties. SEM showed that the electrospun PAN fibers with fiber diameter ranging from 0.5 to 2.7 µm. The diameter of fibers were increased with increasing PAN concentration and voltage applied. The increasing voltage also has increased the bead formation on the fibers. The amorphous structure of electrospun PAN fibers was exhibited by XRD. Electrical conductivity of electrospun PAN fibers were increased with increasing PAN concentration but somehow reduced with increasing voltage of the electrospinning.
Thermal behaviour and microstructural analysis of Sn-0.7Cu alloy and Sn-0.7Cu soldered on electroless nickel/immersion gold
Authors: Teoh Ai Ling , Salleh Mohd Arif Anuar Mohd , Halin Dewi Suriyani Che , Foo Kai Loong , Wahab Juyana A.
Published: December 2019

Lead-free solder has been developing since decades due to the environmental and health harmful of lead solder. To compete with the lead solder, the behaviour and properties of lead-free solder have been continually researched and improved. Sn-0.7Cu is one of the most common solder in application and suitable to be used as a control in research. The thermal behaviour by differential scanning calorimeter (DSC) and microstructure formation with elemental analysis by scanning electron microscope (SEM) of Sn-0.7Cu solder alloy was compared to Sn-0.7Cu soldered on electroless nickel/immersion gold (ENIG) substrate in this study. The result showed that the pasty range of Sn-0.7Cu was lower than Sn-0.7Cu/ENIG while the undercooling was higher. Primary and interfacial (Cu,Ni)6Sn5 were formed in Sn-0.7Cu/ENIG due to the diffusion and dissolution of elements from ENIG substrate. The β-Sn dendrites and eutectic phase of Sn-0.7Cu/ENIG was coarser than Sn-0.7Cu due to the decreasing of undercooling.
Preliminary study of zero charge corrosion protection on steel plate embedded in geopolymer paste
Authors: Razak Siti Aisyah , Zainal Farah Farhana , Shamsudin Shaiful Rizam
Published: December 2019

Steel reinforced concrete usually protected against corrosion by passivation of the steel arising from the high alkalinity of the pore solution within the geopolymer concrete. The ingress of chlorides to the steel or concrete interface or carbonation of the concrete reducing the alkalinity of the pore solution at the steel or concrete interface. This will cause loss of durability in reinforced concrete. The corrosion behavior of steel embedded in geopolymer paste was studied by open circuit potential, Eocp
and potential zero charge method Epzc under 3.5% NaCI solution exposure. The Ecorr
(-660 mV vs SCE) more negative than Epzc
value (-630 mV vs SCE). It shows the steel plate have an excessive negative charges. It is noted that the zero charge corrosion protection (ZCCP) method successfully prevents the steel surface suffering from corrosion. Therefore, it is strongly believed that metal under Epzc is not in contact with H+ and OH− ionic charges due to the absence of electrical charge as well as electrostatic attraction on metal surface.
Physical properties of Sn-3.0Ag-0.5Cu lead-free solder with the additional of SiC particles
Authors: Mahim Zawawi , Salleh Mohd Arif Anuar Mohd , Saud Norainiza , Razak Nurul Razliana Abdul , Yee Khor Chu , Ahmad Romisuhani , Ramli Muhammad Mahyiddin
Published: December 2019

Composite solder has gained researcher’s attention due to its promising improvement in physical and mechanical properties for lead-free solder. To improve the properties of Sn-3.0Ag-0.5Cu (SAC) with the promising lead-free candidate, addition of silicon carbide (SiC) as a reinforcement was used in this study. This study was carried out to identify the effect of SiC particle on microstructure evolution and physical properties of SAC based solder alloys. SAC-SiC composite solder was synthesized by powder metallurgy method (PM), which consists of several processes such as mechanical blending, compaction and sintering. Three different weight percentages of SiC particles; 0.00, 0.50, and 1.00 were mechanically blended with SAC lead-free solder. The results show that the additional of particle SiC was able to refine the microstructure and reduced the size of β-Sn.
A review of geopolymer ceramic as a potential reinforcement material in solder alloys
Authors: Zulkiflii Nur Nadiah ‘Izzati , Abdullah Mohd Mustafa Al-Bakri , Salleh Mohd Arif Anuar Mohd
Published: December 2019

Nowadays, lead-free solder has been currently used in electronic packaging technology as part of soldering material. Since SnPb was detected to produce toxicity and might harm the consumers, the usage of Pb solder has been banned by WEE and RoHS. Therefore, various studies have been developed as alternatives to replace the usage of SnPb. Since lead-free solder might not perform as well as their traditional SnPb, researchers suggested to add some elemental reinforcement particles in matrix alloy. Previously, addition of ceramic reinforcement has been widely known in enhancing the properties of solder-substrate. This paper reviews about the presence studies of ceramic as solder reinforcement, the characteristics of geopolymer ceramic as potential solder reinforcement, and their properties in providing a superior solder joint. In this review, the characterization is divided into two stages; 1) characterization of geopolymers in terms of microstructural and crystallographic; 2) characterization of solder properties in terms of intermetallic layer growth (IMC), wettability, and its mechanical properties
Synthesis of alumina nanoparticles by sol-gel method and their applications in the removal of copper ions (Cu2+) from the solution
Authors: Mohamad Siti Nur Syakirah , Mahmed Norsuria , Halin Dewi Suriyani Che , Razak Kamrosni Abdul , Norizan Mohd Natashah , Mohamad Ili Salwani
Published: December 2019

Two different phases of alumina (Al2O3) nanoparticles (γ-alumina and α-alumina) have successfully been synthesized by using a sol-gel method. During the process a mixture of aluminum nitrate and citric acid (C/N=0.5) was heated at 60°C followed by 80°C until a gel was formed. The amorphous gel structure then was dried and sintered from 600°C to 1200°C. From the X-ray diffraction (XRD) analysis, crystalline structure of γ-alumina started to form at 800°C with average crystallite size of 11.5 nm, followed by the formation of the mixture phase of γ-alumina and α-alumina at 1000°C. The transformation from γ- to α-alumina occured at 1100°C of sintering temperature and above with the average crystallite size of 49 nm. The efficiency of the synthesized alumina nanoparticles as an adsorbents was tested by immersing the powder into the copper ions solution. The percentage of the copper removal was measured by using atomic absorption spectroscopy (AAS). It was found that, the efficiency of the alumina nanoparticles as an adsorbent was not depending on their phases, but might due to the increased of the particle size at higher sintering temperature. The highest percentage of removal 82.1% was obtained when using the alumina sintered at 1200°C.
Effect of Laser Loop on Surface Morphology of Copper Substrate and Wettability of Solder Joint
Authors: Roduan S. Faqihah , Wahab J. A. , Aiman M. H. , Zaifuddin A.Q. , Mohd Salleh M A A , Ishak M.
Published: December 2019

The effect of different laser loop parameter on the geometry of micro-groove pattern on copper substrate and its effect on the wettability was investigated. The micro-grooves pattern was fabricated on the copper surface through laser surface texturing process. 3D measuring laser microscope and contact angle measurement test was conducted to measure the geometry of the micro-grooves pattern and wettability of the solder joint respectively. The results showed that the improvement in laser loop parameter increased the depth of the micro-grooves due to the more exposed time which allows more material ablation. It also showed that the contact angle of textured substrate is smaller than the untextured substrate which results in better wettability.
Effects of ultrasonication process on crystallinity and tear strength of thermoplastic starch/cellulose biocomposites
Authors: Ismail Ibrahim , Osman Azlin Fazlina , Ping Tan Leong
Published: December 2019

The thermoplastic starch (TPS)/cellulose biocomposites were manufactured as green biocomposite films. TPS was produced through plasticization process in which the mixture of starch granule and plasticizers (water and glycerine) went through the stirring and heating process. Cellulose was used as filler and prepared in suspension form through ultrasonication process involving isolation of cellulose in water medium. The ultrasonicated cellulose suspension was added into the TPS matrix to produce TPS/cellulose biocomposites by film casting. The effects of ultrasonication duration (1, 2, 3, 4 and 5 hours) on the crystallinity and tear strength of the TPS/cellulose biocomposite films were investigated. Based on the XRD results, crystallinity of the cellulose and biocomposite were altered by the cellulose ultrasonication process. The tear strength of the TPS biocomposites were greatly enhanced when 5-hours ultrasonicated cellulose was employed as filler. The biocomposites demonstrated 241% higher tear strength than the pure TPS film. This could be related to the transformation of the cellulose into more isolated fiber, with enhanced crystallinity for better reinforcing effect to the TPS matrix.
Coefficient of thermal expansion (CTE) study in metal matrix composite of CuSiC vs AlSiC
Authors: Arif Mohd N , Bukhari Mohabattul Z , Brabazon Dermot , Hashmi M Saleem J
Published: December 2019

Metal matrix composites are widely used as advanced materials for thermal management applications. In view of the demands in higher temperature products application, materials with low coefficient of thermal expansion (CTE) and high thermal conductivity are required. Copper Silicon Carbide (CuSiC) is highly rated as the best materials selected for this application because it has good thermal characteristics especially in CTE, but its density is almost high for high temperature electronic device application. An aluminium silicon carbide (AlSiC) composite, on the other hand, is a new candidate for electronic device application since it has low density and good CTE characteristics. CuSiC and AlSiC composites were fabricated via powder metallurgy method through variety volume fractions such as 5%, 10%, 15% and 20%. In the present study, the comparison of CTE between CuSiC and AlSiC composites with different volume fraction of SiC particles has been carried out. The CTE of CuSiC and AlSiC composites were investigated and their responses between 25°C to 400°C were studied using horizontal dilatometer. Based on the experiment results, the density of CuSiC composites are decrease while the density of AlSiC composites is increase with increasing in SiC particles content. However, the porosity for both composites is increases with increasing in volume fraction of SiC particles. As of CTE, both composites showed decreased with increasing in SiC particles content that dispersed in their matrix. The experimental CTE values for both composites seem to be much lower than theoretical CTE value, which means that there has been excellent bonding between each particle after sintering process. The particles distribution has been observed to understand more on the aspect of SiC particles homogeneity in copper and aluminium matrix.
Characterization of Electrical Current Stress and Indentation Creep of Carbon Nanotubes- reinforced Low Melting Temperature Sn-58Bi Composites
Authors: Sia Kian Lu , Barakbah Syed Alif Ilyasak , How Ho Cheng
Published: December 2019

Sn-58Bi eutectic alloy emerges as one of the potential lead-free solder material candidates due to its low melting temperature that enables low temperature soldering reflow process during the manufacturing of fine-pitch and low z-height advanced microelectronic devices. Its low melting temperature provides feasible solution for a two-step reflow process in the assembly of 3D-stacked advanced packaging technology, and at the same time reduces dynamic warpage-induced quality and reliability issues. However, miniaturization of these microelectronic devices has triggered significant reliability risk to its solder interconnects due to the requirement of high current density that resulted in severe physical failures, such as electromigration (EM), and thermomigration (TM). To mitigate the risk, carbon nanotubes (CNT) are incorporated into elemental Sn and Bi powders using planetary ball milling technique, and subject to liquid phase melting to form low melting temperature CNT- reinforced eutectic Sn-58Bi composites. Electrical resistance and current density of the eutectic alloy and its composites were investigated, and results show that Sn-58Bi-0.03CNT composite has the lowest electrical resistance and was able to survive 26 times longer duration of current stressing, even with the supply of higher stressed current. Creep performance of eutectic Sn-58Bi system was also examined in this study due to its high homologous temperature of 0.72 at room temperature. Marginal improvement in indentation creep performance was seen in the composites.
Territorial aspect of forming united territorial communities
Authors: Hasenko L V , Lytvynenko T P , Hasenko A V , Dariienko V V , Skrynnik I O
Published: December 2019

To ensure the rational use of land resources and manage them in the territory of Ukraine, it was introduced the process of decentralization of power. The article considers the main problems of newly created united territorial communities in the field of land management. In particular, during the study of domestic and foreign experience, as well as the detailed study of Skorokhodivska united territorial community of Chutiv district of Poltava region, the following problems were identified: uncertainty of the boundaries of united territorial communities territories; incomplete use of land outside settlements; lack of revenues to the local budget from the land payments; inability to plan activities due to lack of information on land resources; land pollution; refusal to meet the needs of citizens in land plots; lack of proposals to attract investors and business in united territorial communities; poor state of melioration systems maintenance and illegal use of abandoned forests. The main causes of these problems are analyzed in the article and the ways of their solution are suggested.