bluuebunny/crossref_metadata_2025 huggingface dataset:
SOHO Users' Perceptions of Reliability and Continuity of Cloud-Based Services
Authors: Levy Cornel L. , Elias Nilsa I.
Published: December 2016

The adaptation of cloud computing services is continually growing because of its popularity, its ubiquitous, ease-of-use, and inexpensive nature. Small office/home office (SOHO) businesses are joining large organizations and purchasing cloud services to help with the continuity of their business services. However, cloud computing and its effect in business continuity and information security by SOHO users is not well understood. A qualitative case study was conducted to examine the perspectives of SOHO users of cloud services during Hurricane Sandy in the states of New York and New Jersey. SOHO cloud users were questioned about their understanding of cloud services for business continuity, the services provided by cloud vendors, and their perceptions about cloud data management and security services. The results of this study demonstrated that SOHO users gravitate to the cloud because it of its ubiquitous nature, however, they lack understanding of the business continuity and disaster recovery features and their impact in data security and, their business endurance.
A Critical Crossroads for Computer Science for All
Authors: Margolis Jane , Goode Joanna , Flapan Julie
Published: December 2016

This chapter builds upon research findings that identified pernicious belief systems and structural inequalities that limit opportunities for students of color and females to have access to computer science learning opportunities (Margolis, Estrella, Goode, Holme, & Nao, 2008). The chapter shows how President Obama's agenda of Computer Science for All presents unusual opportunities for and potential threats to attempts to democratize computer science learning. Two approaches to broadening participation in computing are contrasted: “building” and “identifying” talent. These two approaches are examined within the context of school tracking—one of the most persistent structural forms of inequality in today's schools (Oakes, 2005). The Exploring Computer Science program and three case studies of students within the program are discussed as examples of a “building talent,” detracking educational reform.
Exploring African American Middle-School Girls' Perceptions of Themselves as Game Designers
Authors: Thomas Jakita O. , Minor Rachelle , Odemwingie O. Carlette
Published: December 2016

Computational algorithmic thinking (CAT) is the ability to design, implement, and assess the implementation of algorithms to solve a range of problems. Supporting Computational Algorithmic Thinking (SCAT) is a longitudinal project that explores the development of CAT capabilities by guiding African American middle-school girls through the iterative game design cycle, resulting in a set of complex games around broad themes. This paper explores African American middle-school girls' (called SCAT Scholars) perspectives of their SCAT experience and perceptions of themselves as game designers.
Culturally Situated Design Tools
Authors: Eglash Ron , Babbitt William , Bennett Audrey , Bennett Kathryn , Callahan Brian , Davis James , Drazan John , Hathaway Charles , Hughes David , Krishnamoorthy Mukkai , Lachney Michael , Mascarenhas Michael , Sawyer Shayla , Tully Kathleen
Published: December 2016

The “pipeline” model of STEM education conceives of underrepresentation by race, gender and class in terms of leaks that fail to deliver students to their destination in the science and technology workforce. But that model fails to consider the role of STEM in producing underrepresentation. This can only be solved by moving from the extractive approach of the pipeline model to a generative model in which the value produced by STEM students cycles back to their own communities. We report on our experience creating and evaluating Culturally Situated Design Tools. Using a framework of “generative justice”, we contrast the cyclic social damage, which reproduces underrepresentation with the potential for STEM education as a niche in the technosocial ecosystem that can address underrepresentation and causal factors.
Digital Youth Divas
Authors: Erete Sheena , Martin Caitlin K. , Pinkard Nichole
Published: December 2016

Women use technology to mediate numerous aspects of their lives, yet women of color are grossly underrepresented in the fields of computer science and engineering. Decisions about participation in STEM are frequently made prior to high school, and these decisions are impacted by prior experience, confidence, and sense of fit with community. The Digital Youth Divas (DYD) is an out-of-school program that uses narrative stories to launch the creation of digital artifacts and support non-dominant middle school girls' STEM interests and identities through virtual and real-world community. This chapter describes the framework of the Digital Youth Divas program, which blends narratives with project-based design challenges in an informal learning environment. Results suggest that our narrative-centered, blended learning program increases non-dominant girls' knowledge, confidence, and sense of fit in STEM activities.
The Full Knowledge of Big Data in the Integration of Inter-Organizational Information
Authors: Poleto Thiago , Heuer de Carvalho Victor Diogho , Costa Ana Paula Cabral Seixas
Published: December 2016

Big Data is a radical shift or an incremental change for the existing digital infrastructures, that include the toolset used to aid the decision making process such as information systems, data repositories, formal modeling, and analysis of decisions. This work aims to provide a theoretical approach about the elements necessary to apply the big data concept in the decision making process. It identifying key components of the big data to define an integrated model of decision making using data mining, business intelligence, decision support systems, and organizational learning all working together to provide decision support with a reliable visualization of the decision-related opportunities. The concepts of data integration and semantic also was explored in order to demonstrate that, once mined, data must be integrated, ensuring conceptual connections and bequeathing meaning to use them appropriately for problem solving in decision.
Transforming Healthcare through Entrepreneurial Innovations
Authors: Wallin Arto
Published: December 2016

Although digitalization has profoundly changed the business logic in many industries, the healthcare sector still operates in many areas as in the pre-digital era. During recent years, humans have witnessed the rise of new digital health ventures, many of which have revolutionary ideas of how to transform business logics in the organizational fields of healthcare. However, in many cases the institutional arrangements of the field are so strong that new ventures face major challenges in breaking the institutional elements that prevent the introduction and diffusion of service innovations. This paper studies the cases of five companies that aim to transform specific niche areas in healthcare and how these entrepreneurs perceive the influence of institutional elements on their actions.
Framework Towards a Virtual Tool for the Front-End of Employee-Driven Innovation in Healthcare
Authors: Lahtinen Katriina , Aaltonen Satu , Järvinen Marika , Teittinen Outi , Pirttimäki Mikko
Published: December 2016

This paper combines entrepreneurial behaviour and service innovation in order to investigate the use of the Idea Window; a virtual tool planned for employee-driven service development in a healthcare organisation. The empirical study investigates the tool used as a method for supporting employees' collaborative knowledge sharing in front-end of innovation in two study cases. Particularly, the research findings focus on how the virtual tool can be used for tackling the unknown - tacit knowledge, hidden possibilities, and initiatives in the context. The results are based on Idea Window entries and survey data collected in a Finnish hospital ward.
Association Rule Mining of Personal Hobbies in Social Networks
Authors: Yu Xiaoqing , Miao Shimin , Liu Huanhuan , Hwang Jenq-Neng , Wan Wanggen , Lu Jing
Published: December 2016

In this paper, the authors propose an effective scheme for association rule mining of personal hobbies in social networks. By introducing the connection and clipping techniques, the authors are able to ignore unrelated items in the process of finding frequent itemsets, resulting in more accurate candidate itemsets. More specifically, set operations, which are used in the process of combining frequent itemsets, can dramatically reduce the number of databases visited. Furthermore, to explore more practical rules, interestingness level is also introduced to eliminate rules that few people are interested in. The authors' proposed association rule mapping is shown to be able to provide new insights for supporting personalized services and virtual marketing.
Study on the Mechanical Property of 20Cr13 Stainless Steel Barrel Processed by Cold Radial Forging
Authors: Qi Yu Hui , Zhang Xiao Yun , Fan Li Xia , Xu Cheng
Published: December 2016

The barrel is a key part of automatic weapon. And the cold radial forging progress is a new technology for manufacturing the barrels. It will introduce some changes of the material, such as increased strength, decreased plasticity and introduction of anisotropic mechanical property. It can affect the service performance, so it is necessary to study the difference of tangential and axial mechanical properties of barrel blank and forged barrel. This paper focuses on the research of 20Cr13 stainless steel barrel. The mechanical properties of barrel blank and forged barrel are measured by the tensile, compression and bulging test. And the hardness is measured by Vickers hardness tester. The structural change of 20Cr13 stainless steel also has been observed by metalloscope in the metallographic experiment. It reveals the influence of the cold radial forging progress on the mechanical properties of 20Cr13 stainless steel barrel. And it also provides the reference data of the cold radial forging progress of 20Cr13 stainless steel.
A Mesoscopic Mechanics Research on Deformation of 7B04 High Strength Aluminum Alloy
Authors: Sun Ze Ming , Zhu Qi Fang , Fan Zhi Gang , Xia Wen , Liu Shu Feng , Sharkeev Yurii
Published: December 2016

In this paper, a new method mesoscopic been studied for metal material deformation to fracture process. In the polycrystalline material plastic flow process, mesoscopic structural features was obtained for translation - vortex by digital image correlation principle. A preliminary analytical method of material deformation is established. The behavior of plastic deformation of 7B04 high strength aluminum alloy was analyzed. Grain groups deformation, amount of rotation and the energy dissipation distribution were analyzed. An important deformation features is that micro cracks were bred in severe plastic strain region on mesoscopic scale. Based on the stress concentration, the formation of rotational deformation can be regarded as the beginning of an irreversible damage criterion. The Rotation of grain groups is the reason of the formation of microcracks.
Laser High-Speed Impact Composite Forming of Aluminum/Aluminum
Authors: Zhang Hong Feng , Wang Xiao , Ren Xu Dong , Gao Shuai , Liu Hui Xia
Published: December 2016

Based on the laser-driven flyer micro forming and laser high-speed impact welding, this paper put forward the laser high-speed impact synchronous welding and forming new process, and builds the compound welding experiment platform. The three-dimensional deep field digital microscope of KEYENCE VHX-1000C was used to measure the surface morphology and the maximum deformation depth of the welding and formingsamples. By observing the surface morphology of the sample, it was found that strong plastic deformation occurred on the surface of the materials and well reproduced the shape of the mold. When the laser energy was below 4.5J, the maximum deformation depth of the samples increased with the laser energy. However, the maximum deformation depth decreased due to the spring back phenomenon when the laser energy was larger than 4.5J. The Axio CSM 700 confocal microscope was used to measure the morphology of the welding interface. The cross profile of the welding interface showed that most regions had been welded and the welding interface was nearly flat.
Size Effects on Formability of Copper Foil in Flexible Micro-Bending Process
Authors: Ma You Juan , Wang Xiao , Qian Qing , Shen Zong Bao
Published: December 2016

The occurrence of size effects in the microforming leads to the uncertainties in process determination and quality control. In this research, a series of experiments were conducted in UTM4104 testing machine to investigate the grain size effect and feature size effect in micro-bending. Different grain size (d), thickness to grain size ratio () and micro-mold feature size (W) were prepared to explore size effects on formability of copper foil. The formability characterized by forming depth, deformation uniformity and surface integrity was discussed. It was found that the normalized forming depth presented a gradually rise and then declined markedly when N value further decreased to 0.79. The ductile fracture mode was observed for all grain-sized workpiece and the corresponding limit forming depth decreased with increasing grain size. Besides, the thickness thinning distribution and microhardness distribution showed the similar variation tendency like M. Both the standard deviation of thickness reduction and the roughed degree of surface topography indicated the worsening deformation uniformity of the foils with a larger grain size. The inhomogeneous plastic flow of material may be the reason to explain the depression near fracture location which is only observed in coarse-grained workpiece. Overall, it is concluded that the fine-grained copper exhibited better formability as the coarse-grained workpiece experienced severe strain incompatibility.
Evaluation on the Corrosion and Wear Resistance of Welding Zone Welded with Plasma Transferred Arc Welding Method
Authors: Jeong Jae Hyun , Moon Kyung Man , Lee Sung Yul , Lee Myeong Hoon
Published: December 2016

There are many welding methods which have been currently performed to prolong the life time of exhaust valve of marine engine from an economic point of view. In this study, one of these welding methods, plasma transferred arc (PTA) welding was performed at the base metal of Nimonic 80A which would be used as the material of exhaust valve with three kinds of filler metals such as Stellite 6, Inconel 625 and Inconel 718. The mechanical and corrosion characteristics were investigated with electrochemical and wear loss test methods. The Nimonic 80A as the base metal had a better corrosion resistance than those of the weld metals welded with three types of the filler metals. However, after post weld heat treatment, all these weld metals mentioned above exhibited better corrosion resistance compared to the base metal, shifting the corrosion potential to the noble direction, and pitting corrosion was more or less observed at the surface of Nimonic 80A after post weld heat treatment. In particular, Inconel 625 showed the best corrosion resistance among the filler metals after heat treatment. The wear ratio of Stellite 6 showed the lowest value due to its highest hardness among the filler metals, however, its ratio by cavitation test exhibited the highest value. It is considered that increasing of embrittlement with increasing the hardness was resulted in increasing the wear loss by cavitation test.
Hot Deformation Characterization of Mg-Sm-Zn-Zr Alloy Using Artificial Neural Network and 3D Processing Map
Authors: Chang Ruo Han , Cai Zhong Yi , Che Chao Jie
Published: December 2016

The true stress-strain data from isothermal hot compression tests on Gleeble-1500D thermo mechanical simulator, in a wide range of temperatures (350-450°C) and strain rates (0.001-1s-1), was employed to establish the PSO-BP network prediction model and 3D processing map of Mg-Sm-Zn-Zr alloy. It was found that the PSO-BP model could be efficient and accurate in predicting flow stress, most of relative errors were in the range of -4% to 6%, and the average relative error was found to be 1.52%. Then considering the effect of strain, the 3D processing map was established to characterize the hot workability of the alloy. The 3D processing map exhibited the maximum efficiency domain and the instability domain, which could be used to determine the optimal deformation conditions. The optimum processing parameters of Mg-Sm-Zn-Zr alloy were deformation temperatures of 400-450°C and strain rates of 0.003-0.1s-1.
Fracture Analysis of an Aluminum Alloy Gear Pump Housing
Authors: Li Ping , Zhao Yan Jie , Ma Chun Qing
Published: December 2016

The gear pump housing in bulldozer, which was made of cast Al-Si alloy, was found to break in two halves during running. In order to determine fracture reason of the gear pump housing failure analysis in detail were conducted by visual inspection, optical microscope and scanning electron microscope (SEM), chemical analysis, hardness inspection. Visual inspection showed that the crack source has a white semicircle on the interior side of the section and propagated toward the exterior surface of the housing with obvious radial state. Meanwhile, the inner wall has the wear trace in depth of 0.1 mm due to boring phenomenon. SEM observation indicated brittle cleavage fracture mechanism with many casting defects such as dendritic shrinkage and inclusion as well as initiated crack in gear pump housing. The casting defects probably promoted the initiation and propagation of the crack and decreased the loading capacity of the gear to impacting force from the inside shaft. The analysis results show that the failure of gear pump housing mainly resulted from serious boring phenomenon, dendritic shrinkage and the lower material performance.
Lightweight Research on Aluminum Alloy Material of Rear Axle Differential
Authors: Xu Jin Li , He Qiang , Zhu Ding Jun
Published: December 2016

Aluminum and other materials are used more widely with the improvement of car’s weight reduction requirements and the high speed development of new materials. Differential housing is one of the important parts of automobiles drive axle, it is still heavy despite many optimization and improvement because that it is produced by ductile iron. Aluminum alloy material used in the differential housing are studied with FEA. The analysis results show that the weight is reduced by 60%, and a reference is provided for the lightweight of automobile.
Effects of Metal Material Stent Design Parameters on Longitudinal Stent Strength
Authors: Shen Xiang , Xie Zhong Min , Deng Yong Quan , Ji Song
Published: December 2016

The longitudinal stent deformation (LSD) was usually caused by the external force in the blood vessel. The effects of metal material stent design parameters on the longitudinal stent strength (LSS) were studied using finite element method (FEA). A longitudinal stent compression model was developed and a rigid surface was used to compress the stent after stent deployment in coronary arteries. Results showed that the connector length, the strut amplitude and the curvature radius at the crown junctions influenced the LSS hardly. However, the number of connector played the most significant role in the LSS, and increasing the number of connectors can substantially improve the LSS, and the LSS of stent with four connectors was nearly three times than that of the stent with two connectors. For the shape of connector, the LSS of the S-stent, M-stent and L-stent were successively increased. With regard to the L-stent, increasing the width of connector can improve the LSS. Reasonably changing stent design parameters can effectively strengthen the LSS. Conclusions obtained from this paper can help surgeons to select appropriate stents and designers to optimize the stent design to reduce the LSD.
Principles of Optimal Control in the Synthesis of Composite Materials
Authors: Garkina Irina , Danilov Alexander , Selyaev Vladimir
Published: December 2016

It is proposed to use an algorithm for synthesis of composite products with the help of classical optimal control theory, it includes: technical formulation of the problem; development the criteria for optimization; construction mathematical model of the object as a set of partial models. Optimization method is determined after a complete formalization of the problem of synthesizing. It is provided for the possibility of adjusting and simplifying of mathematical problem and its individual elements. Clarification of the formulated technical problem is realized after solving mathematical problem, and iterative process can be repeated until the specified accuracy. It is shown that the synthesis of the material is to convert the object from an initial to a final state under the assumed admissible controls and accepted quality criteria. The approach is illustrated by development of composite materials for radiation protection as multi-purpose complex systems with adjustable characteristics (confirmed the efficiency of the proposed design principles).
The Relationship between the Deformation of Spherical Indentation and Tensile Deformation
Authors: Ogar P.M. , Gorokhov D.B.
Published: December 2016

The paper is devoted to the definition of the deformation during indentation of the sphere and its relationship with the tensile deformation. Proposed by different authors methods of determining the deformation of the contact are considered. The results of their researches may vary significantly. It is shown that in the last decade to determine the deformation, the finite element analysis taking into account the "sink-in/pile-up", i.e. an elastic sinking in and plastic piling up of the material on the edges of the indent during the indentation process is widely used. The purpose of this research is to determine the relationship between tension deformation and sphere indentation deformation with taking into account the last achievements in the field of finite-element modeling of elastic-plastic sphere indentation. It is considered two methods of determining of deformation. One uses the equation proposed by S.I. Bulychev, in which the Mayer’s index is determined from the results of finite element analysis. The second method use the energy concept of hardness. It is based on the assumption that within the range of uniform deformation during uniaxial tension and during sphere indentation, the same energy is consumed to the plastic displacement of the part of the material volume out of limits of initial volume. They have close results. The corresponding graphic relations are shown.
Shear Bond Strength of Orthodontic Bonding Materials Polymerized by High-Intensity LEDs at Different Intensities and Curing Times
Authors: Udomthanaporn Borisorn , Nisalak Passiri , Sawaengkit Pornrachanee
Published: December 2016

To evaluate and compare shear bond strength (SBS) and Adhesive Remnant Index (ARI) of orthodontic brackets polymerized by high-intensity light-emitting diode (LED) curing units at different intensities and curing times. Sixty extracted human upper premolar teeth were divided into 3 groups of 20 each. The tooth surfaces were prepared and the brackets were bonded on the teeth with light-cured adhesive and cured with 3 different light-curing units and conditions; Group 1 (Bluephase, 1,200 mW/cm2, 20 seconds), Group 2 (VALO, 3,200 mW/cm2, 6 seconds), Group 3 (FlashMax P3, 4,000-6,000 mW/cm2, 3 seconds). Shear bond strength of the specimens were tested after bracket bonding for 5 minutes. The means of shear bond strength among groups were compared by Kruskal-Wallis and Mann-Whitney U tests. ARI were tested by the Fisher's exact test (p < 0.05). The means and standard deviations of SBS in groups 1, 2 and 3 were 21.80 ± 2.85, 21.04 ± 2.87 and 4.75 ± 2.82 MPa, respectively. Group 3 had significantly lowest mean SBS. Significant difference of ARI was found between Bluephase and VALO groups (p = .010). FlashMax P3 curing at 3 seconds generated significantly lowest mean SBS among 3 groups. The SBS generated by VALO curing at 6 seconds was not significantly different from Bluephase curing at 20 seconds. Therefore, VALO can be an option for orthodontic bracket bonding benefited in reducing clinician chairtime and patient discomfort.
Granular Material (of Commeasurable and Multi-Dimensional Granules) Properties
Authors: Sandulyak Darya , Ershova Vera , Sandulyak Anna , Sandulyak Alexander
Published: December 2016

The paper analyses the data on measuring the packaging density γ and porosity ω of the medium-loading of balls with d diameter and the loading tank of D diameter, as well as the compound of balls of diameters d1 and d2 ≤ d1. The stabilization of γ and ω was observed with D/d≥4-5: γ=0.61-0.63, ω=0.37-0.39, which allows evaluating the medium-loading of the commensurable granules as a conditionally orderly structure with cells, on average close to square-rhombic ones. As to the compound of the granule-balls in the range of d2/d1=1-0.5, judging by the data on γ and ω variance with d2/d1<0.4-0.5 (up toγ=0.85-0.87 and ω=0.13-0.15 with d2/d1→0), the media-loadings of multi-dimensional granules with characteristic γ and ω values can be considered as provisionally ordered structures with corresponding cells. We provide the expression for defining averaged values of the coordination number of the granule.
The Fabrication of MgB2 Film and Nano-Bridge by EB and FIB
Authors: Li Yan Li , Xu Zhuang , Kong Xiang Dong , Han Li , Li Xiao Na
Published: December 2016

100nm thin Mg/B precursor films were prepared on SiC substrates in ZZSX-500 vacuum coating machine. They were annealed by electron-beam(EB) which only took fractions of a second. In this paper the best annealing duration to fabricate the superconducting MgB2 thin films was investigated. Under the optimized annealing condition(accelerating voltage 15kV, electron beam current 5mA, annealing duration 0.7s), the superconducting MgB2 thin film with critical temperature Tconset~35.3 K and transition width ∆Tc~1K was fabricated. Besides that, a nano-bridge (about 100×200nm2) was etched on the superconducting MgB2 thin film by Focused Ion Beam (FIB). It’s a relative simple and efficient method. The nano-bridge exhibited the effect of Josephson junction with RSJ characteristics. At the same time a little loss of superconducting property was detected.
Extraction of Cellulose Microfibrils from Cassava Pulp
Authors: Nguyen Thanh Chi , Chaiwat Ruksakulpiwat , Ruksakulpiwat Yupaporn
Published: December 2016

Due to the increasing demand of alternatives to unrenewable petroleum supplies, the use of renewable materials for industrial applications is becoming more important. In this regard, cellulose microfibrils (CM) extracted from cassava pulp (CP) are one of promising materials. The objective of this work is to develop a simple chemical treatment to obtain cellulose microfibrils from CP. The process included alkali treatment and acid hydrolysis treatment. The alkali and acid treatments of CP were carried out by using NaOH and HCl solutions, respectively. In an effort to find the optimal conditions for these chemical treatments, various reactions with different temperatures and times were carried out. Besides that, sequence of two reactions (alkali treatment and acid hydrolysis treatment) was also varied in order to find out a proper reaction order for this chemical treatment. The morphological structure, chemical composition, degree of crystallinity and thermal properties of CM were investigated using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and thermogravimetric analysis (TGA), respectively. The results demonstrate that this alkali – acid treatment can remove partially non-cellulosic materials from the structure of fibers and result in higher thermal stability and degree of crystallinity.
The Effect of Lack-of-Fusion Porosity on Fatigue Behavior of Additive Manufactured Titanium Alloy
Authors: Wan Hua Liang , Wang Qi Zhi , Lin Hui Xing
Published: December 2016

As we know, the fatigue performance of AM materials is highly associated with the microstructure. The fatigue performance of additive manufacture alloy materials of Ti-6Al-4V is investigated in this study. Considering the hysteresis energy, a damage evolution equation has been advanced. The material parameters in damage evolution equation are obtained with fatigue experimental data. A homogenizing model with reflecting microstructures is established. Two types of defects, gas porosity and lack-of-fusion porosity, are discussed. The mean fatigue crack initiation lives of additive manufactured Ti6Al4V with different orientations are predicted by the present method. The computational results are agreement well with the experimental data. The effect of lack-of-fusion porosity density on the fatigue performance of AM materials is studied. The fatigue lives of AM materials with different lack-of-fusion porosity size are evaluated. This present method represents the effect of the microdefect on the fatigue performance, with the effect of anisotropic damage and strain.
Synthesis of Porous Basic Magnesium Carbonate Crystallographic Materials with Flower-Like Structure
Authors: Chen Juan , Huang Zhi Liang , Li Wen Zhao
Published: December 2016

The porous basic magnesium carbonate (Mg5(CO3)4(OH)2.4H2O) crystal crystallographic materials with flower-like structure were prepared successfully by homogeneous precipitation method. Magnesium chloride hexahydrate (MgCl2.6H2O) and urea (CO(NH2)2) wereused as reaction materials. The experimental equipment was held at 100°C for 8 h. Phase and morphology of the product were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The formation mechanism of the product was investigated. It was found that the CO2 bubbles acted as porous templates. The growth and gathering of the CO2 bubbles induced the growth of the MgCO3.3H2O columnar crystals. Then the dissolution of the MgCO3.3H2O and the deposition of Mg5(CO3)4(OH)2.4H2O happened simultaneously. Finally the disappearance of MgCO3.3H2O brought about the formation of the porous structure.
Influence of Doping Element Crystal Structure on the Microstructure of Cr Films by Magnetron Sputtering
Authors: Chen Di Chun , Li Hong Tao , Gong Hui , Wang Xiao Ping , Yao Jing Hua
Published: December 2016

Cr films with different doping elements were deposited onto silicon wafer by magnetron sputtering. The microstructure and preferred orientation of Cr films were analyzed by TEM and XRD. The results show that the doping element W with bcc structure can strongly inhibit preferred orientation growth trend along (110) crystal plane of Cr film. A nano-multilayer structure is easily formed in the film, which is composed of Cr and W single layer. The doping element Al with fcc structure can strongly inhibit preferred orientation growth trend along all crystal planes of Cr film. The average grain size of Al (Ce) doped Cr film decreased significantly and the crystallization degree improved with the rare earth element Ce added. Both the doping element Zn with hcp structure and the doping element C with hexagonal structure can inhibit preferred orientation growth trend along (110) crystal plane of Cr film. The mechanism is to form the replacement solid solution and interstitial solid solution with Cr atoms, respectively. Nano-multilayer structure composed of Cr and Zn (or C) single layer formed in the films.
Microwave Absorbing Characteristics of Plasma Sprayed SiC-CNTs/AT13 Absorbing Coating
Authors: Liu Gu , Wang Liu Ying , Ge Chao Qun , Wang Wei , Wei Zhang Juan
Published: December 2016

Electromagnetic parameters of ultra-fine SiC, SiC whisker and nanometer SiC were tested to evaluate the microwave absorbing properties. Optimized nanometer SiC-CNTs/AT13 composite was fabricated by high energy mechanical commixture. Nanometer SiC-CNTs/AT13 absorbing coating was prepared by multi-functional micro-plasma spray system. Morphology and the structure of the powders were characterized by scanning electron microscope. The microwave absorbing characteristic of the coating was evaluated by measuring the reflection loss using an HP8757E scalar quantity network analyzer in the 2-18 GHz band range. The coatings were density, low porosity and uniform morphology. The reflection loss values of -10 dB are obtained in the 2~18GHz range. The minimum reflection loss of the coating is -13.12 dB at 12.64 GHz, and the bandwidth of the reflectivity below -5dB is 9.36GHz. It is indicated that the plasma spraying process is an effective way of preparing microwave absorbing coating.
Biodiesel Production from Used Vegetable Oil Using Ethanol and Sodium Methoxide Catalyst
Authors: Namwong Sureerat , Punsuvon Vittaya
Published: December 2016

Biodiesel is derived from triglycerides by transesterification with methanol or ethanol. In this study, used vegetable oil was transesterified with ethanol using sodium methoxide as catalyst. Parameter affecting the process transesterification were investigated follow this detail. The effects of catalyst to oil volume ratio (3-7:100 %v/v), ethanol to oil volume ratio (20-40:100 %v/v), reaction temperature (55-70 °C) and reaction time (15-90 min.) on the percentage conversion of fatty acid ethyl ester (FAEE) and fatty acid methyl ester (FAME). The FAEE and FAME conversion were detected by 1H-NMR. The result showed that the maximum percentages at 84 % of FAEE and 16 % of FAME were obtained. These conversions were obtained at the catalyst to oil volume ratio of 4:100 %v/v, ethanol to oil volume ratio of 35:100 %v/v, temperature of 65 °C and reaction time of 75 min. The properties of mixed FAEE and FAME biodiesel were within the limits of EN standard. The confirmation result by 1H-NMR and ATR-FTIR also indicated the conversion of used vegetable oil into biodiesel.
Investigation on the Chemical and Physical Properties of Vegetable Oil-Based Polyols for their Potential Application as Asphalt Rejuvenators
Authors: Nciri Nader , Kim Jeong Hyun , Kim Nam Ho , Cho Nam Jun
Published: December 2016

Up to date, no extravagant attempts have been made to use the vegetable oil-based polyols as rejuvenator agents for aged asphalts. In this context, the nature and composition of these biodegradable products need to be identified and physicochemical properties of different nature of compounds need to be measured. Three different vegetable oil-based polyols designed as castor oil polyol, soybean flexible polyol, and soybean rigid polyol were characterized by FT-IR, TLC-FID, 1H-NMR, and 13C-NMR and by the determination of some usual characteristics such as acid value, hydroxyl value, iodine value, and viscosity. It is speculated that the soybean flexible polyol may serve as a potential rejuvenator for aged asphalts.
Effect of STAC on Structure of Biotite when Biotite Transform to Hydrated Ba-Mica
Authors: Wei Yu , Huang Zhi Liang , Huang Xiao Yu
Published: December 2016

After Ba2+/K+ ion exchange, hydrated Ba2+ replaced K+ from interlayer spacing of biotite. original biotite transformed to vermiculite-type hydrated Ba-mica. in order to study the effect of long-chain alkylammonium on biotite after structure changes, biotite, hydrated Ba-mica and mixing mica (A mixture of biotite and hydrated Ba-mica) were used to be modified by STAC (octadecyl trimethylammonium chloride). Fourier transform infrared spectroscopy and powder X-ray diffraction spectroscopywere were used to characterize the obtained samples to reveal the changes of interlayer spacing and basal spacing. The results showed that STA+ could not enter into the interlayer spacing of biotite but enter into that of hydrated Ba-mica and mixing mica. Almost all basal spacing of Ba-mica and mixing mica were increased to 2.8nm.
Simultaneous Determination of Arsenic, Antimony and Bismuth in Chemical Materials by Inductively Coupled Plasma Optical Emission Spectrometry
Authors: Zhou Cheng Ying , Qu Wei , Li Wen Juan , Cai Liu Lu
Published: December 2016

Arsenic, antimony and bismuth in gold ores were simultaneously determined by inductively coupled plasma optical emission spectrometry (ICP-OES) with spectral lines of 188.980, 206.834 and 223.061nm as analytical line respectively, under preset instrumental parameters. The linear range of the method for arsenic, antimony and bismuth was 0~80ug/mL and the correlation coefficient was greater than 0.99995. The detection limit for arsenic, antimony and bismuth was 2.87, 1.63 and 0.84ug/g respectively. The results of this method are consistent with the national standard method, and the relative error is less than 1.5%. The relative standard deviation (RSD) of this method is better than 5.0% (n=11) with good accuracy and precision. ICP-OES can be used for simultaneous determination of multiple elements and is suitable to the analysis of large quantities of samples.
Photocatalytic Degradation of Humic Acid with Metal-Doped TiO2 under Near-Visible Irradiation
Authors: So Ji Yang , Rhee Dong Seok
Published: December 2016

The improvement of photocatalytic activity of TiO2 has been explored. TiO2 has been doped with some transition metal elements for new photocatalytic materials. They were prepared using nitrates of Fe, Cu and Zn. Their photocatalytic activities were investigated by conducting a semi-batch experiment. The degradation of aqueous humic acid was performed under near-visible irradiation. For examining the photocatalytic characteristics of the new materials, the dissolved organic carbon and the UV254 absorption of humic acid were analyzed. The new metal-doped photocatalysts showed higher photoactivities than the synthesized pure TiO2. And photodegradation result of humic acid by the new metal-doped material was even better than by the commercial Degussa P-25 TiO2 at wavelengths of 315 nm - 400 nm.
Thermodynamic Study on Interfacial Reaction between Blast Furnace Slag and Silicon Carbide
Authors: Okuno Hirohide , Fukami Naotaka , Shinozaki Nobuya
Published: December 2016

Silicon carbide(SiC) is used as a raw material contained in the refractory that is in contact with molten iron or slag during steel-making processes. In present work, the interfacial reactions between the SiC ceramic substrate and the blast furnace slag were investigated and the thermodynamic study on the reaction products was carried out. The results showed that the Ti component contained in the slag became TiC, and gathered at the whole interface between the SiC substrate and the slag after experiments.
Investigation of Electrochemical Properties of Elemental Sulfur Dissolved in Alkaline Solution on Rhodium Electrode
Authors: Toktar Gulmira , Bayeshov A.B. , Mintaeva G.A. , Adaibekova A.A.
Published: December 2016

In this article, the electrochemical properties of elemental sulfur dissolved in alkaline solution has been studied for the first time using the method of removing the anodic and anodic-cathodic potentiodynamic polarization curves on rhodium electrodes. The influences of different parameters for oxidation process of elemental sulfur, namely sulfur component in electrolyte concentration, scan rate and temperature were investigated. The resulting polarogram presented in oxidation reaction of polysulfide ions to elemental sulfur process. This shows that polysulfide-ions in electrolyte at cathodic polarization was restored to monosulfide, and monosulfide –ions oxidized to elemental sulfur. The effective activation energy was calculated which equals 13,67 Kj/mol, indicating the oxidation reaction of sulfur occurred in diffusion mode.
Synthesis of High Performance Polycarboxylate Superplasticizer through Redox Initiation System and its Application in Concrete
Authors: Liu Xiao , Guan Jia Nan , Zheng Yun Sheng , Wang Zi Ming , Ren Xiao Wei
Published: December 2016

A high performance polycarboxylate superplasticizer (PCE) was successfully synthesized by a polymerization reaction among acrylic acid (AA), maleic anhydride (MA) and isopentenyl polyethylene glycol (IPEG) through redox initiation system. The composition and amounts of initiation system, and the ratio of monomers were investigated respectively. The proportion of IPGE: MA: AA: sodium methallyl sulfonate (SMAS): ammonium persulfate (APS): ascorbic acid (ASA) was determined as 1: 3: 1.5: 0.3: 0.015: 0.012. Moreover, the effect of polymerization temperature on PCE’s cement paste fluidity was studied. The results showed that the cement pastes mixed with PCE synthesized at 10°C, 20°C and 30°C respectively exhibited better fluidity performances than that mixed with common PCE. The Fourier Transform Infrared Spectroscopy (FTIR) measurements were used for the structural characterization. The results confirmed the occurrence of polymerization reaction and the ideal structure. Furthermore, the application performances of PCE synthesized through redox initiation system in mortar and concrete were tested. The results showed that the water reducing rate of PCE in mortar and the slump performances of PCE in concrete were better than those of the common commercial PCEs. This synthesis method presents the great research value and application prospect for the PCE preparation in concrete engineering.
Analysis of Building Envelope Materials Retrofitting of Timber Dwellings Based on Energy Efficiency
Authors: Huang Chun Hua , Liu Sheng , Liu Yi Ming
Published: December 2016

To find out the optimum building envelope retrofitting methods for timber dwellings in Western Hunan, China, energy efficiency retrofitting strategies of building envelope materials are optimized by an orthogonal test and energy simulation tool, DeST-h. On the premise of protecting their architectural styles, a comprehensive materials retrofitting strategy, a polyurethane foam insulation layer for the double-fir external wall envelope, reed foil for the clay insulation layer roof, using ordinary insulating glass units window material, is provided for the existing timer-structured dwellings in rural area of Western Hunan. After retrofitting, this passive strategy can achieve an energy-saving rate of 64.97%, short 4 years dynamic payback period of investment, and increase by 847h acceptable temperature hours in one year.
Study on Application of Straw as Landscape Wall Construction Material
Authors: Ning Wei , Li Yi Fei
Published: December 2016

This paper considers the existing status of Jilin province crop straw in China. It expounds the comprehensive utilization situation. It reveals existing problems of straw in Jilin province. In this paper, the crop straw is used as the Landscape Wall construction material. Furthermore, the paper analyzes the compressive performance of the straw wall. It is concluded that the straw is feasible for the Landscape Wall construction. The paper can provide effective reference to speeding up the comprehensive utilization of crop straw in Jilin province. This method can also improve the use of new materials in botanical landscape. Besides, the means promotes the construct of saving landscape effectively.
Research of the Uniaxial Compressive Property of the Concrete Mixed with High-Content Fly Ash in Seawater
Authors: Qin Li Kun , Song Hong Wei , Yang Shu Han
Published: December 2016

This paper studies on the frost resistance of high-content fly ash concrete which content 52 fly ash in seawater. The uniaxial compressive property test was carried out after the fast freeze-thaw test with 0, 100, 200, 300 and 400 cycles. The research analyzed the influence of the uniaxial strength of the concrete mixed with high-content fly ash after freeze-thaw cycles in seawater. Then established a mathematical expression in a simple way. In the real project, the concrete mixed with fly ash can improve the frost resistance. The dosage of fly ash will directly influence the frost resistance and mechanical property. However, there is less study on frost resistance of concrete mixed with fly ash, especially the test under the seawater environment.
Finite Element Analysis on the Concrete Damage of Cross-Formation Perforation upon ANSYS/LS-DYNA
Authors: Ma Tao , Yu Hai , Zhou Zhao , Yang Wei , Zhang Zhao , Min Jie
Published: December 2016

Using classical explicit nonlinear dynamic analysis software of ANSYS/LS-DYNA, this paper analyzes the process of perforating jet penetrating on four types of concrete target with unconfined compressive strength of 30 MPa, 50 MPa, 30 MPa & 50 MPa and 50 MPa & 30 MPa. The result shows that penetration of shaped charge will decrease if cross-formation perforation occurs and in order to guarantee the penetration performance during perforating, perforating should be parallel to the direction of oil formation and be avoided from working on high-strength tight formation and up-and-down cap-rock.
Analysis of Flying Rock for Demolition of Cooling Tower Made by Reinforced Concrete Materials in the Method of FTA
Authors: Wang Yang , Wang Xu Guang , Tao Tie Jun , Yang De Qiang , Zhao Ming Sheng
Published: December 2016

In order to fully prevent flying rocks casting to surrounding constructions in blasting demolition project, fault tree analysis was used for safety evaluation. The analysis and calculation of minimal cut sets and structure importance indicates that the highest probability of flying rock accidents is caused by large quantity of maximum priming charge. And other events come second but cannot be ignored. Thus, several measures were adopted according to the analysis result and the final blasting result showed that no flying accidents happened in the whole process.
Magnetic and Electrical Properties of Iron-Based Soft Magnetic Composites with Silicone Resin Insulation Coating
Authors: Li Fa Chang , Li Yi , Liu Xue Quan , Li Jin Pu , Li Nan , Ding Cun Guang
Published: December 2016

This paper investigates the magnetic and electrical properties of iron silicone resin soft magnetic composites. Scanning electron microscopy, energy dispersive X-ray spectroscopy analysis, distribution maps and density measurements confirm that the particles surface layer contains a thin layer of silicone resin with complete coverage of powders surface. The thickness of silicone resin film is averagely 120nm according to the results of transmission electron microscopy. Magnetic measurements show that the silicone resin insulation has a greater heat resistance than the conventional phosphate insulation, which enables stress reliving during annealing at higher temperature (600°C) without a large increase in magnetic loss. The results of annealing at 600°C show that the electrical resistivity increased from 8μΩ·m for SOMALOYTM samples to 55μΩ·m for the silicone insulated composites produced in this work.
1D Finite Element Model for Tapered Cross-Section Steel-Concrete Composite Material Beam
Authors: Xia Jun , Shen Z. , Liu Kun
Published: December 2016

The flexural and dynamic behavior of tapered cross-section steel-concrete composite material beams frequently used in structural engineering is strongly influenced by the type of shear connection between the steel beam and the concrete slab. The numerical model must account for the partial interaction (interlayer slip) in order to get accurate analytical predictions. The 1D high order finite element model for variable cross-section steel-concrete composite beams with interlayer slip were established in this paper. The displacement field of kinematic model is obtained by introducing the constraint condition on interface between those two components based on classical Newmark model. The high order finite element with 16 degrees of freedom (DOF) is chosen to overcome the slip-locking problem in low order finite element which has been reported in published literatures so much. The established element can be used in flexural and dynamic analysis of tapered cross-section steel-concrete composite material beams directly.