bluuebunny/crossref_metadata_2025 huggingface dataset:
Microstructure and Phase Transition Characteristics of NiTi Shape Memory Alloy
Authors: Shilei Zhao , Kun Zhao , Fuwen Wang
Published: November 2020

Shape memory alloy (SMA) with shape memory effect and superelasticity has had an increasing interest for researchers of mechanics of materials in recent decades. With the deepening of theoretical research, the applications of SMA have also made considerable progress. SMA has a unique solid phase transformation characteristic that is thermoelastic martensitic transformation. The high temperature phase of SMA is austenite, while the low temperature phase of SMA is martensite. Because of the biocompatibility and the corrosion resistance, NiTi shape memory alloy has been widely used in biomedical and aerospace. However, the NiTi binary alloy can only be applied to the ambient temperature, because the phase transformation temperature is lower than 100 centigrade. In order to apply the NiTi based shape memory alloy in the wider field, it is necessary to control the phase transformation temperature, thermal hysteresis latent heat of phase change and other phase transformation behavior and mechanical property effectively and accurately. Thus, it is important to add a third or fourth element to NiTi alloy to form a new type of NiTi based shape memory alloy. The results show that NiTi alloy contains many precipitates such as NiTi2, Ni3Ti2, Ni4Ti3. Adding the third or even the fourth element to the NiTi binary alloy can effectively adjust the phase transition and related mechanical properties of NiTi alloy. In this paper, the research progress of NiTi binary alloys is summarized, the microstructure, types and structures of properties, types and properties of phase transitions of NiTi alloys are introduced respectively, the problems faced by NiTi alloys are analyzed and their prospects are prospected, so as to provide reference for the development of shape memory alloys with better properties.
Building Model of Additive Manufacturing Based on Knowledge Driven
Authors: QianZhou Wei , Xiang Ling , XiaoXu Wang , Yu Zhang
Published: November 2020

This paper combines the current mainstream knowledge graph intelligent recommendation algorithm and the first step in the additive manufacturing process: model design, and proposes a knowledge-driven intelligent recommendation algorithm to be applied to model design. Combining the designer’s historical design habits and the relationship between entities and attributes in the knowledge graph can better improve the accuracy of recommendations. It is verified in the third chapter of this article that the knowledge-driven recommendation algorithm is better than other traditional recommendation algorithms.
Development and Design of Detachable Deep Hole Variable Diameter Boring Tool Device
Authors: Liu Zhanfeng , Wang Kun , Feng Yazhou , Li Zhanhui
Published: November 2020

In order to solve the problem of deep hole processing, the inner reaming of small ends and large middle is difficult to process. Developed and designed a detachable deep hole variable diameter boring tool device with self-centering, replaceable tools, and capable of changing the same diameter of the guide block and the tool and with self-locking function. Introduce in detail the structural features, assembly conditions and design principles of the detachable deep hole variable diameter boring cutter device. It provides an effective solution for the processing of inner reaming in deep holes.
Research on Composition Design of Titanium Microalloyed High-Strength Weathering Steel
Authors: Chen Xuewen , Liao Daobiao , Zhou Feng , Bi Jun , Mo Kangxing
Published: November 2020

Based on the EAF-LF-CSP process and the composition of SPA-H (container board) of JIS G3125, this article analyzes and compares the chemical composition and performance of weathering steel related standards and the proposed high-strength weathering steel. By studying the range of Ti addition, designing the chemical composition of high-strength weathering steel, and developing high-strength steel with a yield strength of 450∼700MPa. The analysis and calculation results show that the optimal Ti content range of weathering steels of various strength grades with yield strength of 450MPa∼700 MPa is 0.05∼0.08%, 0.08∼0.12%, and 0.12∼0.14% respectively, which meets the strength requirements of weathering steels and can be applied in production practice.
Adaptive Control of Additive Manufacturing Equipment Based on Air Bearing Positioning
Authors: Xiang Ling , QianZhou Wei , Yu Zhang
Published: November 2020

The air bearing guide rail is used as the three-dimensional positioning mechanism of additive manufacturing. However, in the high acceleration and high speed high dynamic motion, it is easy to cause the residual vibration of the system, damage the positioning accuracy of the system and increase the stability time of the system. Therefore, under the condition that the expected dynamic and static performance of additive manufacturing equipment is controllable, the robust adaptive control is used to compensate manufacturing error and environmental disturbance. According to Lyapunov stability theory, the established controller is adjusted to ensure the global asymptotic stability of the whole control system, so as to improve the system reliability and robustness to parameter changes.
Analysis of Influencing Factors on Viscosity of Agar Solution for Capsules
Authors: Yu Zhenhua , Zhan Jianbo , Wang Hao , Zheng Han , Xie Jiao , Wang Xu
Published: November 2020

The viscosity of agar solution for capsules depends on the molecular structure and chemical composition of agar. In addition, many external factors also affect its viscosity, such as concentration, temperature, metal ions, electrolyte and non electrolyte, mechanical stirring shear. In this paper, the factors that affect the viscosity of the liquid, which mainly include concentration, temperature and pH, are studied. The results showed that the order of the influence on the viscosity of agar solution was agar concentration > water hardness > solution temperature > pH. Within the range of this experiment, agar concentration, water hardness and solution temperature have significant effects on the viscosity of agar solution, while the pH of solution has no significant effect on the viscosity.
Nonlinear predictive control of horizontal vibration of high speed elevator
Authors: Wang Hong , Zhang Mingqin , Zhang Ruijun , Zhang Luzhong
Published: November 2020

This Aiming at the problem of horizontal vibration of high-speed elevators caused by the guide rail excitation, firstly, considering the nonlinear characteristics of the spring rigidity and damping of the guide shoe system, a four-degree-of-freedom high-speed elevator nonlinear horizontal vibration model is established. Secondly, the state equation of horizontal vibration of high-speed elevator is derived, and the system state is processed by Taylor expansion. The quadratic performance index of predictive control is introduced, and the active control law with analytic form is solved by optimizing the performance index. Finally, the simulation using MATLAB verifies the correctness of the model. By further solving the control law and simulation, the results prove that predictive control can effectively reduce the horizontal vibration of high-speed elevators.
A preconditioned conjugate projected gradient method for computing eigenvector derivatives with repeated eigenvalues
Authors: Xia Xiao , Fan Qinyin , Yang Shitong
Published: November 2020

A preconditioned conjugate projected gradient (PCPG) method is given to solve the repeated eigenvector derivatives with respect to design parameters in finite element models. The factored stiffness matrix is used as a preconditioner, the new method can provide the approximate solutions to repeated eigenvector derivatives. This method can be used as an eigenvector sensitivities solver which can be coupled as an eigensolver/derivative software. Moreover, the new method can be used for industrial-size models. Finally, a numerical example is provided to illustrate the superior efficiency of the present method.
A bibliometric review of the water security concept in Central Asia
Authors: Xenarios Stefanos , Assubayeva Aliya , Xie Lei , Sehring Jenniver , Amirkhanov Daulet , Sultanov Alisher , Fazli Siamac
Published: November 2020

Engineering, economic, social sciences, geophysical, and integrated modeling studies have approached the assessment of water security in Central Asia (CA) in distinct ways. Different indicators and indexes have been introduced to assess the most vulnerable aspects of water use in this region. Until now, though, the suggested approaches are often represented in a fragmented manner, while the relevant indicators cannot fully attribute the vulnerability status of a country or on a regional level. This can result in diverging perceptions of the water security situation in policy dialogues, also affecting bilateral and multilateral relations among the countries in CA. In this study, we conduct a bibliometric review on the approaches and methods that directly or indirectly touch upon the water security perceptions in CA. We employ data mining techniques to explore trends in the conceptualization of water security in the region since the breakup of the Soviet Union by also identifying the water interests and priorities set by each country. The findings reveal that within the last decade, the water security-related studies have given much importance to technical and infrastructural means to protect human livelihoods against global environmental changes but also to foster economic growth. The water governance and management aspects are largely overlooked in favour of more techno-centric approaches. These findings are expected to clarify further the perception of the water security concept within CA by indicating the geophysical, institutional, and historical challenges that need to be met for a mutual understanding among the countries in the region.
Beyond SOx reductions from shipping: assessing the impact of NOx and carbonaceous-particle controls on human health and climate
Authors: Bilsback Kelsey R , Kerry Deanna , Croft Betty , Ford Bonne , Jathar Shantanu H , Carter Ellison , Martin Randall V , Pierce Jeffrey R
Published: November 2020

Historically, cargo ships have been powered by low-grade fossil fuels, which emit particles and particle-precursor vapors that impact human health and climate. We used a global chemical-transport model with online aerosol microphysics (GEOS-Chem-TOMAS) to estimate the aerosol health and climate impacts of four emission-control policies: (1) 85% reduction in sulfur oxide (SOx) emissions (Sulf); (2) 85% reduction in SOx and black carbon (BC) emissions (Sulf-BC); (3) 85% reduction in SOx, BC, and organic aerosol (OA) emissions (Sulf-BC-OA); and (4) 85% reduction in SOx, BC, OA, and nitrogen oxide (NOx) emissions (Sulf-BC-OA-NOx). The SOx reductions reflect the 0.5% fuel-sulfur cap implemented by the International Maritime Organization (IMO) on 1 January 2020. The other reductions represent realistic estimates of future emission-control policies. We estimate that these policies could reduce fine particulate matter (PM2.5)-attributable mortalities by 13 300 (Sulf) to 38 600 (Sulf-BC-OA-NOx) mortalities per year. These changes represent 0.3% and 0.8%, respectively, of annual PM2.5-attributable mortalities from anthropogenic sources. Comparing simulations, we estimate that adding the NOx cap has the greatest health benefit. In contrast to the health benefits, all scenarios lead to a simulated climate warming tendency. The combined aerosol direct radiative effect and cloud-albedo indirect effects (AIE) are between 27 mW m−2 (Sulf) and 41 mW m−2 (Sulf-BC-OA-NOx). These changes are about 2.1% (Sulf) to 3.2% (Sulf-BC-OA-NOx) of the total anthropogenic aerosol radiative forcing. The emission control policies examined here yield larger relative changes in the aerosol radiative forcing (2.1%–3.2%) than in health effects (0.3%–0.8%), because most shipping emissions are distant from populated regions. Valuation of the impacts suggests that these emissions reductions could produce much larger marginal health benefits ($129–$374 billion annually) than the marginal climate costs ($12–$17 billion annually).
A review of chemical stabilisation in road construction
Authors: Tan E H , Zahran E M M , Tan S J
Published: November 2020

This paper presents a literature review of the application of cement, lime and polymer emulsion in road construction. The focus is mainly on the soil candidates, binding mechanism, the reported strengths and weaknesses for each chemical stabiliser used in soil stabilisation. While it is generally agreed that cement is best suited for sand-sized to gravel-sized soil mixtures (well-graded), lime is mainly used for wet heavy-clay soil mixtures. Polymer emulsion is more suitable for silt-sized to fine gravel-sized soil mixtures (well-graded). Organic soils are the most difficult soil type to stabilise, and for any kind of chemical stabiliser used, the strength gain is relatively minimal. Cement undergoes hydration reaction which is rapid, and results in high compressive strength, while lime undergoes a slower pozzolanic reaction is slower, and provide lower compressive strength. Polymer emulsion depends on the rate of evaporation for the film formation to complete, and results in ductile polymer-soil matrix. Like lime, polymer does not provide significant compressive strength but does provide great flexural strength that prevents crack propagations. The outcomes from this paper provide an insight into recent and upcoming research trend using chemical soil stabilisers on local soil mixtures to improve the engineering properties of pavement layers made of these soil mixtures.
Manipulation of Electrolyte Concentration and Cathode Morphology to Control the size of the Carbon Nanoparticles
Authors: Ranjit M S , Yang B L Y , Julaihi M R M
Published: November 2020

The research aims to study the effects of concentration of the electrolyte and morphology of the cathode rod on the synthesis and size control of the carbon nanoparticles. The research was conducted using the submerged glow discharge plasma (SGDP) method. Potassium carbonate a strong electrolyte was used to maintain the accuracy of the results. The glow discharge voltage and any instabilities were recorded and monitored to obtain trends during the synthesis of carbon nanoparticles. Moreover, the shapes and sizes of the carbon nanoparticles formed were also observed and analyzed. The SGDP method is both eco-friendly and cheap to conduct. Carbon nanoparticles range from 1 – 100 nm. The small size of these nanoparticles gives it a high surface area to its volume ratio over sheet and bulk metals. The nanoparticles have different mechanical properties with respect to their sizes. The ability to control the sizes of the nanoparticles will enable manufacturers to obtain the mechanical properties they desire. The research conducted was able to determine the factors which enables the control of the sizes of carbon nanoparticles formed. At higher electrolyte concentration and higher cathode thickness, the size of the carbon nanoparticles decreased.
Characterization and evaluation of copper-doped akermanite ceramic
Authors: Htun M M , Noor A F M , Kawashita M , Ismail Y M B
Published: November 2020

The aim of this study is to investigate the influence of copper (Cu2+) on structural and mechanical properties of akermanite ceramic synthesized via high-energy wet planetary ball-milling route. Based on structural analysis, partial substitution of copper ions did not affect the phase stability of host akermanite. Moreover, Cu2+ suppressed the grain growth, thus considerably improved the sinterability and mechanical properties of akermanite ceramic. Vickers microhardness values of doped samples increased to five- or six-times compared to that of pure akermanite at 1200°C. Our study indicated that the Cu2+-doped akermanite ceramic could potentially be used as an alternative material for bone replacement in biomedical applications.
Study on size control of TiO2 nanoparticles synthesized using solution plasma process
Authors: Yii B W M , Yek P Y N , Ranjit M S , Liew B Y Y , Julaihi M R M
Published: November 2020

Abstract The research was conducted to study the size control of TiO2 nanoparticles synthesised. The TiO2 nanoparticles was formed using the solution plasma process. This method is an electrolysis of water-based experiment. When compared to other methods, the solution plasma method offers both a shorter synthesis time as well as a simple setup. Researches conducted on nanomaterials have proven that these materials tend to have varying properties when compared to bulk metals. With this, being able to vary the sizes of the TiO2 nanoparticles meant being able to study its possible future applications. One being using these nanoparticles for the fabrication of solar cells. Varying the sizes of these nanoparticles could bring a difference in the reactivity which can help enhance the performance of the solar cells. In order to vary the sizes of the nanoparticles, the concentration of the electrolyte was varied. During the research, it was found that the sizes of the TiO2 nanoparticles decreases with the increase in the concentration of the electrolyte.
Temperature on the Mechanical, Thermal and Barrier Property of Polyurethane
Authors: Yeap P I , Yuhana N Y , Fariz S , Otoh M Z
Published: November 2020

Polyurethane is a type of segmented polymer which is synthesized from polyisocyanate, polyol and chain extender. The reaction between isocyanate and hydroxyl bond is known as polymerization. Two-step synthesis is used in synthesizing polyurethane, where polyisocyanate reacts with polyol to form pre-polymer, follows by the reaction between pre-polymer and diol. In this research, different weight percentages of triethylenediamine catalyst (0.0%, 0.2%, 0.4%, 0.6% and 0.8%) are used. Moreover, curing time and temperature that examined in this research is at a temperature of 70ºC for 24 hours (Set A), which is practised in the industry. Curing at shorter time and higher temperature is proposed, which is 70ºC for 2 hours followed by 100ºC for 3 hours (Set B). Mechanical property and absorption property of polyurethane is studied by Shore A hardness test and water absorption test respectively. Morphology of polyurethane is studied by Scanning Electron Microscopy (SEM). Moreover, density test, Thermogravimetric Analysis (TGA) and Fourier Transform Infrared Spectroscopy (FTIR) analysis are carried out.
Extraction of reinforced epoxy nanocomposite using agricultural waste biomass
Authors: Kaur Manpreet , Mubarak N. M. , Lai Fui Chin Bridgid , Khalid Mohammad , Rao Karri Rama , Walvekar Rashmi , Abdullah E.C. , Amri Tanjung Faisal
Published: November 2020

The growing awareness and concern of having greener and biodegradable materials has promoted researchers over the world to focus their attention on studies related to natural fibre reinforced polymer composites. In this study, the mechanical and thermal properties of the coconut shell powder and lignin obtained from different extraction methods such as Alkaline and Organosolv, on the epoxy composites were studied. The composite was fabricated using hand lay-up method, where the coconut shell and lignin fibers of 1, 2, 3 and 4 wt.% were mixed with the matrix consisting of epoxy resin and hardener in the ratio of 10:3. The obtained result showed that the usage of coconut shell powder and lignin as reinforcing fillers enhances the tensile strength and Young’s modulus of composite when compared to neat epoxy composite by 16.4%, 14.6%, 9.70%, and 31.4%, 25.3%, 17.2% respectively at filler content of 3 wt. % but reduced the elongation at break up to 49.9% with respect to higher content of filler. Similarly, the flexural strength and Young’s modulus was enhanced by 13.5%, 10.0%, 6.57% and 49.6%, 39.1%, 19.6% respectively at filler content of 3 wt.% but reduced the elongation at fracture up to 19.0% with respect to higher filler content. Structural characterization was also carried out where fillers were proven to enhance the purity and strength of the lignin.
A Review on Biodiesel Synthesis using Iron Doped Catalyst
Authors: Foo Yu Herng , Hua Tan Yie , Mujawar Mubarak Nabisab , Kansedo Jibrail , Shi Tan Inn , Chee Yew Foo Henry , Lokman Ibrahim Mohd
Published: November 2020

This paper summarized on the history of biodiesel synthesis, biodiesel synthesis using iron doped catalyst. Biodiesel are gaining enormous attention from researches and manufacturers considering its advantages of non-toxic, biodegradable, renewable, and environment-friendly in order to improve the air quality over the atmosphere followed by reducing the global warming problems effectively. Regarding the conventional biodiesel production method, manufacturers generally utilize vegetable oil and alcohols to pass through the transesterification process with the presence of homogeneous base catalyst. The utilization of this types of catalyst lead to another environmental issues that most of the researches are concerning about since the homogeneous catalysts are not reusable and causing separation problems between oil products and the catalyst itself. Therefore, it is highly necessary for the researches and manufacturers to further explore and investigate some catalyst types that are truly feasible for high-scale or industrial usage. Heterogeneous catalysts are known to consists of an identical phase with the reacting medium where the liquid phase contains the feedstock and reaction medium whereas the catalyst retain within the solid phase, hence resolving the separation problems that the homogeneous catalyst would lead to. Recently, researches have introduced the novel method of magnetic properties impregnation of catalytic active component onto the carbonaceous compound. This proposed action tends to provide the advantages of high surface area, separation ease, and preventing the leaching of catalytic active components from the catalyst. Both the potential iron doped carbon catalyst have been extensively researched and studied within this report. Besides, the catalyst properties have discussed further for analyzing the effects of the biodiesel yield that introduced by the chemical and physical properties of various types of catalysts.
The effect of the spacing and angle arrangement of the droplet on the spreading area in simultaneous multiple droplets deposition
Authors: Pau K Y , Sung A N
Published: November 2020

Simultaneous multiple droplet deposition involves dispensing of multiple droplets at the same instant on the substrate. A newly defined parameter, arrangement angle is considered as one of the factor that influencing the coalescence of the multiple droplets. However, the effect of such factor on the coalescence is largely neglected in the past. The paper aims to investigate the effect of droplet centre-to-centre distance and arrangement angle on the spreading area of four droplet deposited simultaneously using simulation method. The project starts with single droplet deposition and following by simultaneous multiple droplet deposition. For single droplet deposition, the spreading area of 80% wt aqueous glycerin droplet on the glass substrate were obtained using simulation and experimental methods. A correlation function was introduced to match the simulation result with the experiment result. For simulations of multiple droplet deposition, three droplet centre-to-centre distances as 2.22 mm, 3 mm and 4 mm and three droplet arrangement angles as 90°, 110° and 120° were studied. The larger the droplet spacing, the larger the spreading area for arrangement angle of 90°. The spreading area are largest for spacing of 4 mm, followed by 2.22 mm and 3 mm for arrangement angle of 110° and 120°. The arrangement angle is proven as a factor that affect the spreading area.
The Effect of Fertilizer on Epipremnum Aureum in Phytoremediating Soil Contaminated with Crude Oil
Authors: Tang K H D , Chai H T J
Published: November 2020

Epipremnum aureum is a common ornamental foliage which is used mainly for indoor decoration. It demonstrates tolerance to low light environment and the ability to remove atmospheric chemicals such as gasoline and formaldehyde. A previous screening study showed the ability of Epipremnum aureum to remove crude oil from soil. Further to the screening study, this study examined the effect of fertilization on phytoremediation of crude oil-contaminated soil by Epipremnum aureum Epipremnum aureum was grown in pots with soil contaminated with 5%, 10% and 15% of crude oil by weight respectively, with and without the addition of fertilizer. In line with previous study, Epipremnum aureum showed the ability to remove crude oil contaminants. The plant demonstrated highest crude oil removal rate in pots with 15% contamination. Application of fertilizer enhanced the removal of crude oil in all experimental pots by Week 6, hence increasing the rate of crude oil decline over the experimental duration. It is deemed that application of fertilizer provides nutrients to promote plant growth and proliferation of roots which enhance rhizodegradation of crude oil in soil. This study extends on the existing knowledge that Epipremnum aureum can phytoremediate crude-oil contaminated soil by characterizing its tolerance to crude oil and its response to fertilization, which is crucial to its practical application in phytoremediation. Phytoremediation presents a promising yet cost-effective measure in treating contaminated land. Further study can examine the optimum fertilizer concentration for phytoremediation and the tolerance level of Epipremnum aureum to crude oil contamination.
A Review on One-Way Concrete Wall Under Axial Loading
Authors: Ting T Z H , Rahman M E , Lau H H
Published: November 2020

As concrete wall panel is gaining popularity in precast construction industry, better insight into its behaviour is of paramount importance. Considerable research has been carried out on concrete wall under axial loading. Most of the published literatures have proposed design equations for wall design purpose. In this aspect, the paper is aimed to review the design equations of one-way concrete wall. The limitations of existing design equations are subsequently identified.
Multi-Compartment Vehicle Routing Problem to Find the Alternative Distribution Route of Petroleum Product Delivery
Authors: Febriandini I F , Yuniaristanto  , Sutopo W
Published: November 2020

Distribution is an activity that the firm has to do to deliver their product to the customers. The product has to deliver to the customers on the right condition, at the right time, and with the minimal cost of delivery. This paper focuses to solve the planning distribution problem on petrol product delivery or Petrol Station Replenishment Problem. One of the ways to solve the planning distribution is VRP (Vehicle Routing Problem). VRP aims to find the minimal total cost delivery with some constraints depend on the factory. In this research, VRP is used by the distribution center to find the optimal route of distribution of petrol products. Using Multi-Compartment Vehicle Routing Problem (MC-VRP) that considers the demand for the petrol product, tank-truck capacity, distribution cost, and the number of the compartment. In this work, a mathematical formulation for MC-VRP is developed in the Mixed Integer Linear Programming (MILP) model. Using Ilog Cplex with branch and bound algorithm to solve this distribution problem with the minimum total distribution cost. There are 10 customers with different distances, different time deliveries and different travel costs in this research. The mathematic formulation produces the best alternative that is Rp 1.898.584 to deliver products from depot to the customers.
Strategy Business of Battery Swap for Electric Vehicle Using Business Model Canvas
Authors: Sholichah AI , Sutopo W
Published: November 2020

Electric vehicles have developed rapidly in this global era. Many countries have replaced conventional vehicles into electric vehicles. Electric vehicles need batteries as electric reservoirs. The way to charge batteries for electric vehicles is only through charging and it takes a long time, so the idea of battery exchange grows to simplify battery changes in electric vehicles. This study aims to design a business for battery exchange with a canvas model business approach consisting of 9 important factors such as customer segments to map the market, channels to facilitate information provided to consumers, value propositions or set prices according to consumers by providing some advantages from battery replacement products, customer relationships or maintaining good relationships with consumers, revenue streams provide or provide other services in addition to battery changes, key resources to establish cooperation with raw material suppliers or banks to facilitate and provide discounts to consumers, key activities describe the activities to be carried out in the company, key partners give discounts to consumers who want to become members or regular customers, and the cost structure makes a breakdown of funds or costs from raw materials to commercial costs such as promotions, water, electricity, and so forth. The business model that has been formed will be the basis for designing a busines plan consisting of a management profile and financial analysis. Researchers conducted qualitative research, namely data collection is done by searching from the previous literatre. This research and analysis is to design a battery exchange business that can be done in the future.
Adoption of Building Information Modelling in Malaysia Road Construction
Authors: Yung A T B , Aminudin E , Liat C N S , Neardey M , Zakaria R , Hamid A R A , Ahmad F , Yong L Y
Published: November 2020

Building Information Modeling (BIM) has changed the road development industry in the most recent decades. In spite of the fact that there are activities by administration of Malaysia to improve the selection of BIM in road development, yet the usage of BIM is still not true to form because of misty guide of BIM reception plan in Malaysia. Along these lines, it is essential to recognize the issues and difficulties in usage of BIM so as to improve the selection of BIM in this industry. This paper plans to analyze the street development industry in Malaysia to build up an unmistakable comprehension about BIM execution and to give the key arrangements and system for street development industry to expand the reception of BIM in Malaysia. This paper has built up broad BIM understanding which makes ready for the investigation by means of subjective and quantitative technique where the information is gathered through study poll among the street development partners in Malaysia and the gathered information is dissected with Average Index utilizing SPSS Software. The outcomes indicated the degree of current BIM usage in Malaysia street development industry is still extremely low and the issues and difficulties of BIM are distinguished in six zones incorporate specialized, process, legitimate, return of venture, government and individuals. Government has been recognized to assume a significant job in offering help to improve appropriation of BIM in Malaysia. The result of this investigation is communicated as a system for the usage of BIM in Malaysia involving issues that require thought for association to advance on BIM development stepping stool. This investigation clears a firm establishment for association to settle on choice in the appropriation of BIM in street development inside the general association structure.
Recycling of concrete construction and demolition waste in alternative binders: Part 1 – Technical study
Authors: Petrov B Y , Zaharieva R A
Published: November 2020

The concrete construction and demolition waste (CDW) is usually recycled as coarse aggregate. The fine fraction remains unused – if recovered at all, it is for downcycling in backfilling. Part 1 of this article is dedicated to a technical study on recycling of the waste concrete powder (WCP) as supplement in blended cements. Part 2 presents assessment of the environmental impacts of those binders. XRD and DTA/TG analyses of WCP are performed. WCP from two types of concrete CDW is used. The behaviour of fresh and hardened pastes with replacement of CEM I 52,5 by WCP (15%, 30% and 45%) is investigated. Standard methods of testing with some modifications are used. The influence of WCP content on the setting, consistency, strength and water absorption is evaluated. Four different curing regimes are applied. The results confirm the initial assumption that WCP can be consider as cementitious supplement. The replacement rate up to 15% practically does not change the behaviour of the binder, while 45% seems to be the maximum, because of binders performances degradation. The replacement up to 30% allows to keep satisfactory technical properties, but offers greater economic and environmental advantages.
Recycling of concrete construction and demolition waste in alternative binders: Part 2 – Environmental footprint
Authors: Kancheva Y D , Zaharieva R A
Published: November 2020

The concrete demolition and construction waste (CDW) is usually recycled as aggregate. The fine fraction (crushed sand and powder) obtained from the recycling process remains less recovered – for downcycling purposes such as backfilling, if recovered at all. The feasibility study on the recycling of concrete waste as a component of a blended binder is presented in Part 1 of the study. Part 2 is dedicated to a preliminary assessment of the environmental impacts of the partial replacement of Portland cement binder by a waste concrete powder (WCP). The assessment is focused on the binder production stage as per BDS EN 15804 and does not consider any further scenarios. The environmental impacts of alternative binders with a different amount of WCP is compared to the impacts of conventional cement types CEM I, CEM II/A and CEM II/B. The results confirm that there is a significant reduction of the environmental impacts when WCP is used for cement replacement, because of the more efficient use of material resources and energy. The effect is more pronounced with the higher replacement rate. Therefore, the use of WCP in cements leads to more eco-friendly binders and can contribute to closing the concrete loop.
Experimental study of flat reinforced concrete slabs created in the method of early striking
Authors: Bakardzhiev S
Published: November 2020

This report examines the behaviour of an experimental two-storey monolithic construction during the construction of its flat slabs with a formwork system suitable for the application of early striking. The experimental results of the deformations in the slabs are compared with those from the numerical model of the construction. The peculiarities in the findings of the strength characteristics of the concrete used for the monolithic structure in the tests are analysed. Conclusions are made regarding the production of reinforced concrete slabs through formwork systems suitable for early striking from these results and comparisons.
Response of a reinforced concrete cantilever beam subject to impulse impact loads
Authors: Stoynova I , Christov T
Published: November 2020

To study the response of a RC cantilever beam subjected to impulse excitations is based computational model. Static and dynamic analysis of the computational model was performed using a software product based on the Finite Element Method. Two numerical models have been builded for static analysis. In the first model, the concrete modelled with a linear - elastic material model and the reinforcement as deformable bars. In the second model, the concrete modelled using a nonlinear model of concrete - the material model of Willam and Warnke, and the reinforcement as deformable bars. For dynamic analysis, concrete modelled as a linearly elastic material and reinforcement as deformed bars. Under impulse loading, the applied force acts for a very short but limited time interval. This article presents five cases of impulse duration. The dynamic time-history analysis used to determine the dynamic response of the RC cantilever beam under the action of time variables. This type of analysis used to determine time-varying displacements, stresses, and internal forces caused by a combination of static and dynamic (pulse and harmonic) loads. A dynamic time-history analysis used to study the dynamic response to time-varying loads. The time-determined displacements, deformations, stresses and internal forces give the behaviour and reaction of the structure at any time in the studied interval.
Seismic behaviour of brickwork chimneys in buildings
Authors: Ivanov R I
Published: November 2020

The construction of chimneys of solid bricks in buildings with sloped roofs was commonplace in Bulgaria for almost a century. The collapse of a chimney during an earthquake could potentially lead to damages greatly exceeding the loss of the chimney itself, e.g. partial damage to the roof tiling and leaks, as well as material damage, injury or loss of life due to debris fall. A FEM model was created, in which the storeys of the building are represented in a generalised way, while the chimney is modelled explicitly as a cantilever supported at roof level. The internal forces in chimneys with heights ranging from 0.5 m to 2.0 m, belonging to buildings with height ranging from two to seven storeys were computed. Acceleration records from real earthquakes acting at the base of the building with varying peak ground acceleration and predominant period were used for input loading. The maximum tensile stresses at the bed joints were computed and were compared to the typical tensile strength of the mortars used for chimney construction, to assess the possibility of collapse. A simple, low-tech method for upgrading of existing chimneys by applying a coat of cement-based plaster with embedded fiberglass mesh is proposed.
Nanostructured polypyrrole layers implementation on magnetically navigable 3D printed microdevices for targeted gastrointestinal drug delivery
Authors: Bernasconi R , Favara N , Fouladvari N , Invernizzi M , Levi M , Pane S , Magagnin L
Published: November 2020

The integration of drug releasing polymeric layers on remotely navigable microcarriers is one of the most promising therapeutic strategies for a wide variety of diseases. Thanks to this approach, administration can be precisely targeted to a specific organ, limiting thus side effects and drug waste. In this context, the present work describes the fabrication of 3D printed and wet metallized microdevices intended for targeted drug delivery. Microtransporters are stereolithography printed and coated with a sequence of materials to impart them specific functionalities, like magnetizability and chemical inertness. Polypyrrole (PPy), in both bulk and nanostructured (NA) form, is electrodeposited as top layer to introduce drug delivery properties. Fabricated microdevices are characterized from the morphological and functional point of view. In particular, remote magnetic control and drug release behavior are investigated. Results obtained show a high magnetic maneuverability and good drug loading capability, which is further improved by nanostructuring the PPy layer applied on the surface of the microdevices. A possible application for the magnetically steered carriers described in the present work is localized drug administration for the therapy of many diseases typical of the gastrointestinal tract (e.g. Chron’s disease).
Ag-Pd core–shell electrocatalysts for ethanol oxidation and oxygen reduction reactions in alkaline medium
Authors: Shi Jianchao , Wang Jie , Chen Yumei , Sun Yulong , Liu Baozhong , Fan Yanping
Published: November 2020

Ag-Pd core–shell nanoparticles with different thickness of Pd shell are successfully prepared applying polyol methods with 1,2-propanediol as a solvent and reducing agent. A strongly electronic interaction between the sublayer Ag and surface Pd atoms are measured for the Ag-Pd core–shell particles with lower Pd/Ag atom ratios (Pd:Ag ⩽ 3:10), which derives from the near-surface alloying effect. Upon increasing the thickness of Pd shell, the effect of Ag core on surface Pd atoms become weaker, correspondingly the surface Pd atoms present the features closed to pure Pd. All Ag10@Pdx/C core–shell catalysts exhibit improved ethanol oxidation reaction (EOR) activities compared to pure Pd/C. Here, the EOR activities of Ag10@Pdx/C catalysts decrease when adding the thickness of the Pd shell, in which the Ag10@Pdx/C with the lowest Pd/Ag ratios (Pd/Ag = 1:10) shows the highest i
p value ten times that of Pd/C. The participation of Ag as a core with low electronegativity and larger lattice constant can increase the electron densities and bring the lattice expansion of surface Pd atoms, due to the electron effect and the geometric effect, which effectively strengthen the bonding energy of reaction species on Pd surface and benefit the OH– adsorption for EOR, especially in lower Pd/Ag ratios than forming a monolayer Pd. For oxygen reduction reaction (ORR), the Ag10@Pdx/C samples also exhibit enhanced activities than pure Pd/C. Differently, there is a volcanic relation between the mass activities and the Pd/Ag atom ratios, where the Ag10@Pd3/C with about a monolayer Pd shell exhibits highest ORR activity. The improved ORR activities may be relay on the appropriate OH– adsorption, the exposed surface Ag atoms and the quick transformation of OH from Pd atoms.
Nuclear magnetic resonance spectroscopy of biofluids for osteoarthritis
Authors: Clarke Emily J , Anderson James R , Peffers Mandy J
Published: November 2020

Background

Osteoarthritis is a common degenerative musculoskeletal disease of synovial joints. It is characterized by a metabolic imbalance resulting in articular cartilage degradation, reduced elastoviscosity of synovial fluid and an altered chondrocyte phenotype. This is often associated with reduced mobility, pain and poor quality of life. Subsequently, with an ageing world population, osteoarthritis is of increasing concern to public health. Nuclear magnetic resonance (NMR) spectroscopy can be applied to characterize the metabolomes of biofluids, determining changes associated with osteoarthritis pathology, identifying potential biomarkers of disease and alterations to metabolic pathways.

Sources of data

A comprehensive search of PubMed and Web of Science databases using combinations of the following keywords: ‘NMR Spectroscopy’, ‘Blood’, ‘Plasma’, ‘Serum’, ‘Urine’, ‘Synovial Fluid’ and ‘Osteoarthritis’ for articles published from 2000 to 2020.

Areas of agreement

The number of urine metabolomics studies using NMR spectroscopy to investigate osteoarthritis is low, whereas the use of synovial fluid is significantly higher. Several differential metabolites have previously been identified and mapped to metabolic pathways involved in osteoarthritis pathophysiology.

Areas of controversy

Conclusions are sometimes conservative or overinflated, which may reflect the variation in reporting standards. NMR metabolic experimental design may require further consideration, as do the animal models used for such studies.

Growing points

There are various aspects which require improvement within the field. These include stricter adherence to the Metabolomics Standards Initiative, inclusive of the standardization of metabolite identifications; increased utilization of integrating NMR metabolomics with other ‘omic’ disciplines; and increased deposition of raw experimental files into open access online repositories, allowing greater transparency and enabling additional future analyses.

Areas timely for developing research

Overall, this research area could be improved by the inclusion of more heterogeneous cohorts, reflecting varying osteoarthritis phenotypes, and larger group sizes ensuring studies are not underpowered. To correlate local and systemic environments, the use of blood for diagnostic purposes, over the collection of synovial fluid, requires increased attention. This will ultimately enable biomarkers of disease to be determined that may provide an earlier diagnosis, or provide potential therapeutic targets for osteoarthritis, ultimately improving patient prognosis.
The Entorhinal Cortical Alvear Pathway Differentially Excites Pyramidal Cells and Interneuron Subtypes in Hippocampal CA1
Authors: Bell Karen A , Delong Rayne , Goswamee Priyodarshan , McQuiston A Rory
Published: November 2020

The entorhinal cortex alvear pathway is a major excitatory input to hippocampal CA1, yet nothing is known about its physiological impact. We investigated the alvear pathway projection and innervation of neurons in CA1 using optogenetics and whole cell patch clamp methods in transgenic mouse brain slices. Using this approach, we show that the medial entorhinal cortical alvear inputs onto CA1 pyramidal cells (PCs) and interneurons with cell bodies located in stratum oriens were monosynaptic, had low release probability, and were mediated by glutamate receptors. Optogenetic theta burst stimulation was unable to elicit suprathreshold activation of CA1 PCs but was capable of activating CA1 interneurons. However, different subtypes of interneurons were not equally affected. Higher burst action potential frequencies were observed in parvalbumin-expressing interneurons relative to vasoactive-intestinal peptide-expressing or a subset of oriens lacunosum-moleculare (O-LM) interneurons. Furthermore, alvear excitatory synaptic responses were observed in greater than 70% of PV and VIP interneurons and less than 20% of O-LM cells. Finally, greater than 50% of theta burst-driven inhibitory postsynaptic current amplitudes in CA1 PCs were inhibited by optogenetic suppression of PV interneurons. Therefore, our data suggest that the alvear pathway primarily affects hippocampal CA1 function through feedforward inhibition of select interneuron subtypes.
A Sensitive and Specific ESI-Positive LC–MS/MS Method for the Quantitation of Estrogens in Human Serum in Under Three Minutes
Authors: Stella Aaron , Dey Subhakar
Published: November 2020

Amplifex Diene reagent was employed to derivatize estradiol (E2) to enhance the analyte signal at low picogram concentrations. This derivatization enabled measurement of E2 (and other estrogens) in ESI+ mode, earlier retention times for analytes than other methods, avoidance of MS harmful ammonium fluoride in mobile phases, and an LLOQ below 1 pg/mL. The sample preparation workflow involved liquid–liquid extraction followed by Amplifex Diene derivatization for 10 min at ambient temperature. Samples were chromatographed using a standard C18 column and analyzed using a SCIEX 6500+ mass spectrometer. The assay calibrators were prepared in-house, traceable to certified reference materials, and ranged from 1.29 to 624 pg/mL. A method comparison to samples from the CDC HoSt program yielded a correlation coefficient of 0.9858 and bias of −1.37%. The LLOQ using certified reference material was 0.66 pg/mL. The intra-run precision was <9.00% for low- and high-level samples, whereas the inter-run precision was 15.2 and 5.43% for low- and high-level samples, respectively. No interference from other clinically relevant steroids was found. Amplifex Diene derivatized E2 and estrone (E1) was found to be stable for over 6 months, both refrigerated and frozen.