bluuebunny/crossref_metadata_2025 huggingface dataset:
Millennial Teamwork and Technical Proficiency's Impact on Virtual Team Effectiveness
Authors: Graham C. Matt , Daniel Harold , Doore Brian
Published: August 2016

The successful completion of information systems projects is already a difficult process that many times ends with projects failing to meet the information systems requirements. These requirements typically center on completing projects that perform the way initially envisioned, and delivering completed projects on time and within budget. Pressures around communication and leadership style are now compounded by the use of virtual teams. The goal of this study was to determine whether or not technical proficiency in the project-based skills, facility with database management systems development, and greater technical proficiency in coping within the virtual environment contributed to the development of greater virtual team effectiveness. This study targeted millennial students at the Maine Business School who were assigned to virtual teams tasked with developing a database management system within a virtual environment. Findings suggest that increased proficiencies in project skills will contribute to greater team effectiveness and more importantly, increased proficiencies within the virtual environment will contribute to greater virtual team effectiveness. These findings have implications for business educators and by natural extension, business practitioners as they suggest that training students and workers how to communicate, collaborate, exchange ideas, and share information better within virtual environments will improve virtual team effectiveness which should translate into greater virtual teams project outcomes.
Young Connected Migrants and Non-Normative European Family Life
Authors: Leurs Koen
Published: August 2016

In the face of the contemporary so-called “European refugee crisis,”' the dichotomies of bodies that are naturalized into technology usage and the bodies that remain alienated from it betray the geographic, racial, and gendered discriminations that digital technologies, despite their claims at neutrality and flatness, continue to espouse. This article argues that “young electronic diasporas” (ye-diasporas) (Donà, 2014) present us with an unique view on how Europe is reimagined from below, as people stake out a living across geographies. The main premise is that young connected migrants' cross-border practices shows they ‘do family' in a way that does not align with the universal European, normative expectations of European family life. The author draws on three symptomatic accounts of young connected migrants that are variably situated geo-politically: 1) Moroccan-Dutch youth in the Netherlands; 2) stranded Somalis awaiting family reunification in Addis Ababa, Ethiopia; and, 3) working, middle, and upper-class young people of various ethnic and class backgrounds living in London. Narratives shared by members of all three groups indicate meta-categories of the ‘migrant,' ‘user,' and ‘e-diaspora' urgently need to be de-flattened. To do this de-flattening work, new links between migrant studies, feminist and postcolonial theory and digital cultures are forged. In an era of increasing digital connectivity and mobility, transnational families are far from deterritorialized – boundaries and insurmountable distances are often forcibly and painfully felt.
Feeling (Dis)Connected
Authors: Dhoest Alexander
Published: August 2016

While most research on the e-diaspora focuses on connections within heterosexual families and communities, this paper explores the transnational connections and digital media uses of LGBTQ migrants. Based on semi-structured interviews with 23 LGBTQs living in Belgium, two groups are distinguished: voluntary migrants, who chose to move, and forced migrants, who (felt they) had to leave their country because of their sexual orientation. Comparing their familial and ethno-cultural connections, it becomes clear that both groups – for varying reasons and to varying degrees – feel disconnected from their countries of origin, families, and ethno-cultural communities in Belgium. For all participants, digital media are a key tool to maintain some connections, but particularly for the forced migrants ‘context collapse' on social media leads to a sense of insecurity. Overall, this research illustrates the importance of intersecting variables in research on the e-diaspora, as well as the impact of ‘offline' legal and material conditions on online media uses.
Nollywood Afrogeeks
Authors: Arthur Tori
Published: August 2016

Viewing Nigerian film, known as Nollywood, in online platforms provides African immigrants living in the United States with digital spaces to engage with the African continent through films with relatable Pan-African themes. Nollywood on social media sites (YouTube and subscription services IrokoTV, Amazon, and Netflix) marks the Nigerian film industry as a transnational participatory movement that enables immigrants to use the technology at their disposal to watch and comment on films, connect with their cultural values, and become a part of a global digital community of dispersed Africans and African descended populations. Thus, immigrants become a part of a Nollywood focused digital diaspora, a cultural space that illuminated the plurality immigrants negotiate on and off the continent.
Diasporizing the Digital Humanities
Authors: Risam Roopika
Published: August 2016

The field of digital humanities has expanded in recent years to encompass a range of practices and practitioners around the world and has changed the nature of scholarly communication. So too have emerged centers and peripheries of the field that privilege scholarly production of the United States, the United Kingdom, and Canada. This article examines efforts to challenge the hierarchical dimensions of power, making the case for viewing transnational scholarly networks through a logic of diaspora.
Collaborative Business Service Modelling in Knowledge-Intensive Enterprises
Authors: Le Dinh Thang , Thi Thanh Thoa Pham
Published: August 2016

Nowadays, knowledge-intensive enterprises, which offer knowledge-based products and services to the market, play a vital role in the knowledge-based economy. In the global networked age, collaborative business services have raised as one of the most important knowledge-intensive services that help enterprises to gain the competitive advantage. These services greatly depend on the ability to use network architectures to collaborate efficiently with business partners. This paper introduces the KB-CBSM (Knowledge-Based Collaborative Business Service Modelling) approach, which aims at providing a conceptual foundation for modelling effectively and improving incrementally collaborative business services in knowledge-intensives enterprises. The paper begins by presenting the necessity and principles of the KB-CBSM approach. Next, it presents the conceptual foundation that consists of three levels: Service value creation network, Service system and Service levels. The paper continues with a discussion and review of the relevant literature and ends with the conclusion and suggestions for further research.
Information Processing Approach in Organisational Cognitive Structures
Authors: Bergman Jukka-Pekka , Platonov Vladimir , Dukeov Igor , Röyttä Pekka , Luukka Pasi
Published: August 2016

Despite of increasing interest in social cognitive research in strategic management during recent years, few studies have examined the relationship between cognitive structures of top management and middle management. This study represents the information processing approach in managerial cognition research assuming that top management communicate their shared cognitions into the organization reducing ambiguity of operative environment faced by the other levels of organization shaping the operations of the organizations. The authors' empirical study examines managerial cognitive maps collected with a cognitive mapping method in a transportation company. In the study, top managers and middle managers separately evaluated sustainability management issues and their relevance for the company providing 75 individual cognitive maps. Based on this, the authors' study aims to fill the gap in research of relationship between top management and middle management cognitive structures and increase understanding on role of managerial cognition in strategic management research.
Applying Enterprise Social Software for Knowledge Management
Authors: Antonius Nicky , Gao Xiangzhu , Xu Jun
Published: August 2016

This paper investigates the application of Enterprise Social Software for knowledge management in Australia. The Enterprise Social Software researched here assisted in collaborative knowledge sharing to support data-driven decision making. Enterprise Social Software was beneficial for complex tasks, especially those that involved a wide range of collaborators such as multi-disciplinary teams or geographically distant users. Australian knowledge workers found Enterprise Social Software to be extremely helpful in enhancing their externalisation and combination, but less proficient in socialisation and internalisation. In overall, there was agreement among respondents that Enterprise Social Software was facilitating them to meet work requirements which would be very hard or impossible to deliver without. The findings highlight Enterprise Social Software as a technological platform that diffuses the task complexity facing knowledge workers in Australia as a representation of the next generation Knowledge Management Systems.
Classification of Polarity of Opinions Using Unsupervised Approach in Tourism Domain
Authors: Goyal Mahima , Bhatnagar Vishal
Published: August 2016

The recent growth of e-commerce websites has paved a way for the users to express their opinions on these web portals which, in turn, makes the customers review these comments before buying any product or service. The comprehensive reading of these large number of reviews is cumbersome and tiring. The purpose of this paper is to perform the analysis on the tourism domain reviews to decide whether the document is positive or negative. The traditional methods use a machine learning approach, but the authors are using an unsupervised dictionary based approach to classify the opinions. The scores of the opinions are extracted using Sentiwordnet, a popular dictionary for calculating the sentiment.
Preparation and Coefficient of Friction of YBa2Cu3O7-δ/Graphene Oxide Composites
Authors: Chu Yanqiu , Xu Jing , Li Changsheng
Published: August 2016

YBa2Cu3O7-d/graphene oxide (YBCO/GO) composite materials were fabricated by using powder metallurgy process combined with cold isostatic pressing (CIP) technique. The coefficient of friction (COF) of YBCO matrix composites with addition of 0, 0.5, 1.0 and 2.0 wt% GO were reported for the first time. The friction behavior was observed by means of the ball-on-disk technique with a steel ball used as the counterpart in ambient atmospheric and dry sliding condition. The measured properties were then assessed with respect to sliding speed and the mass fraction of the GO additives. GO is able to reduce COF and brittleness for YBCO ceramic. The excellent performance offers materials with 0.5 wt% GO, which has the lowest COF and lightest wear track.
Benefits from Using Bitcoin
Authors: Schmidt Rainer , Möhring Michael , Glück Daniel , Haerting Ralf , Keller Barbara , Reichstein Christopher
Published: August 2016

Bitcoin is the most successful approach for establishing a currency outside of state supervision and government institutions. Besides, Bitcoin is very controversial discussed. Therefore, a further investigation of different aspects of the benefit of using Bitcoin should be realized in order to identify some core aspects of the digital currency Bitcoin. In this context, the study described in the following achievements is done. It shows that there exist key aspects, like dissemination as well as safety, which are important impact factors on users' benefit of using a digital currency like Bitcoin. In addition, it also gives implications for a further development of the topic and aspects for future research.
On Understanding Preference for Agile Methods among Software Developers
Authors: Bishop David , Deokar Amit V. , Sarnikar Surendra
Published: August 2016

Agile methods are gaining widespread use in industry. Although management is keen on adopting agile, not all developers exhibit preference for agile methods. The literature is sparse in regard to why developers may show preference for agile. Understanding the factors informing the preference for agile can lead to more effective formation of teams, better training approaches, and optimizing software development efforts by focusing on key desirable components of agile. This study, using a grounded theory methodology, finds a variety of categories of factors that influence software developer preference for agile methods including self-efficacy, affective response, interpersonal response, external contingencies, and personality contingencies. Each of these categories contains multiple dimensions. Preference rationalization for agile methods is the core category that emerges from the data. It informs that while the very essence of agile methods overwhelmingly and positively resonates with software developers, the preference is contingent on external and personality factors as well.
Selective Attention to Commercial Information Displays in Globally Available Mobile Application
Authors: Liu Yi , Tan Chuan-Hoo , Sutanto Juliana
Published: August 2016

The prevalence of mobile applications has revived research interest in examining the issue of how commercial information (e.g., adverts) can be displayed to yield click-throughs. Mixed perspectives are proposed over whether or not adverts should be integrated into the primary media content. By anchoring on the load theory of selective attention, this research proposes that user response (attention) to consistent adverts (i.e., adverts that are contextually consistent with the media content) is contingent on how they are displayed (intra- and inter-pages). This study subjected the worldwide users of a location-based mobile social networking application to random manipulations of intra-page and inter-page advert displays. The findings reveal that controlling for the geographical locations of the users, high click-through counts are obtained when consistent adverts are displayed at the early stage of application interaction (top position of the front page), but the effect diminishes as users scroll down to the bottom of front page and navigate to subsequent pages.
Experimental Research on Bearing Strength and Effect Laws for Woven GFRP Composite Laminates
Authors: Liu Ling , Li Hua Dong , Mei Zhi Yuan
Published: August 2016

Based on ASTM D 5961 standard, the double-shear bearing strength and effect laws for woven glass fiber/vinyl resin composite laminates are studied. By testing of various specimen, bearing chord stiffness line is properly determined according bearing stress range, and effect laws on bearing strength are analyzed when (±45)°/(0/90)°plies proportion and fastener torque get changed. The results show, with 40%~60% (±45)°plies proportion, the bearing strength and the offset bearing strength simultaneously reach to the high value region with small fluctuation. As fastener torque increases, bearing strength increasing trend gets slow while offset bearing strength first increases and then decreases.
Repair of Flexuously Impact Damaged CFRTP Applying an Inserting Method with Tiny Melted Sheet of PP Resin Modified with Fine Glass Fibers
Authors: Ootani Ryohei , Okubo Kazuya , Fujii Toru
Published: August 2016

The purpose of this study is to reveal the effects of the modification of the sheet of Polypropylene (PP) with fine glass fibers for repair of the Carbon Fiber Reinforced Thermo Plastics (CFRTP) on the recover ratio of degraded mechanical properties of damaged CFRTP after impact bending. Impact damaged specimen was repaired by inserting tiny melted sheet of PP modified with fine glass fibers to be assimilated with PP matrix around the surface of damaged area. Model specimens having cut reinforcements were prepared for compressive buckling tests to investigate the effect of the modification on mechanical behaviors under compressive stress due to the impact bending. The recovering ratio defined as the ratio of compressive buckling strength of damaged model specimen to that of un-damaged specimen was investigated. The recovering ratio of model specimen after the repair was about 49% when the unmodified PP sheet was used to repair. On the other hand, when the weight content rate of fine glass fibers was 2.0wt%, about 73% of recovering ratio was successfully obtained. The appropriate condition of the weight content rate was shown for repairing the damaged part of the CFRTP used in this study.
Development and Application of Bamboo Activated Carbons and their Potency as Adsorbent Material for Adsorbed Natural Gas (ANG); An Overview
Authors: Negara Dewa Ngakan Ketut Putra , Nindhia Tjokorda Gde Tirta , Surata I Wayan , Sucipta Made
Published: August 2016

Currently, the use of activated carbon (AC) increased significantly for the industrial sector, health, environment and agriculture. However, the commercial price of activated carbon is relatively expensive, especially for micro industries mainly due to high production costs. Additionally, it comes from non-renewable sources with limited availability. This prompted the researchers to study the production of AC from inexpensive precursors and renewable; one of which is made from bamboo. AC production can be done through a pyrolysis process followed by physical or chemical activation. Differences in raw materials and activation methods used can affect the characteristics and quality of activated carbon produced. This paper reviews the development and application of bamboo activated carbons in the life sectors and their potency for use as an adsorbent material for the absorbed natural gas (ANG).
In Situ Electrochemical Study of Copper Nanoparticles Stabilized with Food Grade Gelatin
Authors: Datu Ellaine , Balela Mary Donnabelle L.
Published: August 2016

Commercially available conductive inks are typically made up of precious metal nanoparticles, such as gold (Au) and silver (Ag). Thus, cheaper metals like copper (Cu) are currently being explored as alternative material. Though Cu has a comparable conductivity to that of Ag, they tend to oxidize easily when exposed to air and water, which could limit their application. In this work, oxidation-stable Cu nanoparticles with mean diameter as small as 57 nm were prepared by simple electroless deposition in water. Food-grade gelatin was used as stabilizer, which makes the process more economical and environment-friendly. In situ monitoring of mixed potential was carried out during synthesis to understand the kinetics of the reaction. The mixed potential of the solution shifted negatively as the amount of gelatin was increased. This suggests faster reduction rate.
Electrical Characteristics of Different Gate Geometry of FinFET
Authors: Patcharasardtra Nuttapong , Pengchan Weera
Published: August 2016

This paper proposed to the electrical characteristics of difference gate geometry of FinFET. Four of difference gate structure have been designed and simulated by GTS Framework TCAD software which is simulation the characteristics of FinFET device include drain current-voltage, threshold voltage and subthreshold swing. Then, the electrical characteristics was compared. From the result found that the drain current depend on gate geometry of FinFET. The largest gate geometry of FinFET device was the rectangle shape with gate width at 66 nm, IDS about 19.8 mA and VTH = 0.5 V and the smallest gate geometry, the triangle shape with gate width at 52 nm and give IDS about 8.5 mA and Vth = 0.5 V.
Strong Down-Conversion Emission of Sm3+ Doped Borotellurite Glass under 480 nm Excitation Wavelength
Authors: Rafien Siti Nasuha , Kasim Azman , Hashim Azhan , Syamsyir S. Akmal , Abdullah Mardhiah , Naveed M.A.
Published: August 2016

Tellurite glasses were generally applied in rare earth optical materials due to their excellent in physical and chemical properties. In this study, tellurite glasses composed of (70-x)TeO2-20B2O3-10ZnO-xSm2O3 (x = 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 mol %) were prepared by conventional melt-quenching technique. Some basic physical parameters such as density, molar volume and oxygen packing density as well as the optical analysis by mean of their absorption and emission spectra have been carried out at room temperature using UV/Vis and photoluminescence spectrophotometer. The result of physical properties are found to vary with respect to concentration of Sm3+ ions content. Meanwhile, three strong absorption peaks are observed and are well resolved in the ultra violet and visible regions due to transitions between the ground state and various excited state of Sm3+ ions. Under 480nm laser excitation, luminescence spectra exhibit four emission bands at 562 nm, 599 nm, 645 nm and 706 nm which corresponding to the transition 4G5/2 → 6H5/2, 4G5/2 → 6H7/2, 4G5/2 → 6H9/2 and 4G5/2 → 6H11/2 were observed. Some other results were also been analysed and presented.
Viscosity and Density of Co-B Liquid Fusions
Authors: Konashkov Viktor V. , Vyukhin Vladimir V. , Tsepelev Vladimir S.
Published: August 2016

Kinematic viscosity and density of cobalt liquid alloys with boron is studied. Range of boron concentration was from 1 to 8 mass percent. The chemical composition of real industrial alloys is in limits of this range of concentration. Viscosity and density measurements of all samples are taken in a wide temperature interval. Measurements of viscosity are taken by method of torsional fluctuations of a crucible with fusion. Measurements of density are taken by method of a sessile drop. Existence of density data significantly increased the accuracy of processing of experimental data of viscosity. It is revealed that kinematic viscosity can be different at one and same chemical composition of an alloy. It is established that upon transition through the eutectic concentration of boron, nature of viscosity dependences from temperature of a liquid alloy changes. The explanation option of the found regularities is offered.
Thermodynamic Study on Interfacial Reaction between Molten Iron and Spinel
Authors: Okuno Hirohide , Fukami Naotaka , Shinozaki Nobuya
Published: August 2016

The effect of the oxygen concentration in the molten iron on the formation of the FeO-MgO phase at the interface between the MgAl2O4 spinel substrate and the molten iron was investigated at 1833 K on the basis of thermodynamics. The results showed that the FeO-MgO phase was formed at the interface between the molten iron and the substrate, if the oxygen concentration in the molten iron was larger than 0.04 mass% for the 50mol%Al2O3-50mol%MgO substrate and 0.08 mass% for the 61mol%Al2O3-39mol%MgO substrate, respectively. For both the substrates, with increasing the oxygen concentration in the molten iron, the activity coefficient of FeO in the spinel substrate increased, and when this value reached above 1.5, a part of MgO was discharged from the spinel and reacted with Fe and oxygen in the molten iron to form the FeO-MgO phase.
Effect of Grit Type, Aging Temperature, and Aging Time on Particle Size of Ground Natural Rubber/Zeolite Composite Powder
Authors: Ondoy Karl , Pajarito Bryan B.
Published: August 2016

This study reports the results of investigation on the main and interaction effects of grit type, aging temperature, and aging time on particle size of ground natural rubber/zeolite (GNR/Z) composite powder using general factorial design of experiment. GNR/Z composite powder produced by mechanical grinding is porous, like an aggregated chain structure. These aggregates exist in clusters of irregular shape. Analysis of variance (ANOVA) shows that the effects of aging temperature and aging time depend on the particle size range. GNR/Z composite powder with large particle size is produced when aging is done at low temperature and short time due to high resistance of rubber to oxidation. On the other hand, GNR/Z composite powder with small particle size is produced when aging is done at low or high temperature and longer aging time. Low temperature condition offers high O2 concentration available to oxidize rubber while high temperature condition leads to more chain scissions due to higher oxidation rate.
Time Dependent High Dimension Model of Functional Gradient Thermal Barrier Coating Material
Authors: Zhao Chen , Li Yu Guang , Zhang She Sheng
Published: August 2016

A high dimension time dependent model of designing functional gradient thermal barrier coating material is built by using optimization theory. The difference algorithms is used to solve inverse heat transfer problems. The heat conduction coefficient is founded by using volume fraction function of ceramic or metal. An example of calculation shows that the gradient thermal barrier coating can improve material function.
Butane/Propane Gas Sensing Using Zinc Oxide Film Grown by Successive Ionic Layer Adhesion and Reaction
Authors: Florido Emmanuel A. , Solidum Sarah Allyssa
Published: August 2016

This study was aimed to test the ability of zinc oxide (ZnO) film fabricated by successive ionic layer adsorption and reaction (SILAR) to detect liquid petroleum gas consisting of a mixture of butane/propane gas. The film was fabricated by alternate dipping of pre-cleaned glass substrates in a sodium zincate bath and in a 95°C hot water bath using an automated dipping machine to control the sequence and dipping time. Scanning electron microscopy (SEM) revealed a uniform film consisting of wurtzite ZnO nanorods for the sample grown using 0.1M concentration of sodium zincate and 200 dippings. Current-voltage characterization of the samples showed an average resistivity of 1.343 Ω-m. EDS analysis of the film confirmed the existence of zinc oxide with 65.9% zinc and 34.1% oxygen. The ZnO film exhibited an ability to detect the gas with an average gas response of 0.44, average response time of 14 seconds and average recovery time of 25 seconds using a gas concentration in air of 1.5 % by volume. Response time is the time for the sensor to reach the peak voltage output from the start of gas exposure while recovery time is the time for the voltage output to return to the initial value without gas when the gas is removed from the chamber. The zinc oxide film also showed a voltage output of 100, 109.31, 118.92, 123.61, 133.5, and 149.52 mV when exposed to percent volume gas concentrations of 0, 0.5, 0.75, 1.0, 1.25, and 1.5, respectively with a correlation coefficient of 0.97. The sensor sensitivity is 32 Δ(mV)/Δ(%conc).
Fabrication and Characterization of Ultra Water Repellent Surfaces on Aluminum Alloy Substrate
Authors: Chi Ri Han , Yu Zhijia , Yu Zhi Jia , Kuang Guo Zhu
Published: August 2016

The fabrication of metallic ultra water repellent surfaces is of great significance to many industrial and scientific areas. Ultra water repellent surfaces on aluminum alloy substrates were fabricated with acidic etching and fluoroalkyl silane coating method. The prepared surfaces exhibit good water repellent behaviors with water contact angles (WCA) larger than 150° and contact angle hysteresis (CAH) about 5°. The resultant surfaces were examined using scanning electron microscope (SEM). The results show that a kind of hierarchical roughness in micro-nanoscale is formed, which plays a key role for the fabrication of ultra water repellent surfaces. Fancy phenomena such as "chair-shaped flow", "flow orientation" and "sinusoidal flow" were observed when water flowed in a rectangular conduit constructed with one ultra water repellent wall and one super hydrophilic wall on the opposite side. The observations reveal some characteristics of water flow in ultra water repellent conduits.
Morphological Studies on Spray Deposited Lanthanum Sulphide (La2S3) Thin Films
Authors: Bagde Govind , Londhe C.T. , Bagde A.G.
Published: August 2016

The spray pyrolysis was employed to prepare Lanthanum Sulphide (La2S3) thin films on silicon non conducting glass substrate using lanthanum chloride and thioacetamide from aqueous medium. The effect of preparative parameters on film properties was studied. Further thin films characterization was carried out by electrical resistivity, thermoemf, optical, XRD and SEM measurement techniques. The electrical resistivity was the order of 104 – 105 Ω cm and it shows semiconducting behavior. The Thermoemf studies reveal that Lanthanum Sulphide material is P-type. The direct band gap of Lanthanum Sulphide (La2S3) thin films was estimated to be 2.5 eV. The XRD studies indicate that Lanthanum Sulphide (La2S3) thin films are polycrystalline. A morphological study shows that the Lanthanum Sulphide (La2S3) thin films have fibrous network.
Formation of Carbonated Apatite Layer in 1.5× Simulated Body Fluid at Different Refreshing Time
Authors: Mohd Tajudin Muhammad Hanis , Tapsir Zafirah , Ismail Lukman Hakim , Saidin Syafiqah
Published: August 2016

Bioactivity analysis in simulated body fluid (SBF) is an experiment or protocol conducted to evaluate the bioactive properties of a sample without involving cells. The bioactive property is claimed based on the formation of apatite layer after immersion in SBF. This analysis consumes expensive chemical reagents and requires complex procedure in preparing and refreshing the solution. Therefore, the aim of this study was to identify significant alteration of refreshing time in the 1.5× SBF to form an apatite layer on a polydopamine (PDA) grafted stainless steel (SS316L) disk. The SS316L disks were pre-treated and grafted with a PDA layer to equip the bioinert metal surface with a bioactive film. The PDA grafted disks were subjected to bioactivity analysis in SBF for 7 days at different refreshing time (24 h, 48 h, 72 h and not refreshed up to 7 d). The surfaces were then characterised by FTIR, SEM-EDX, and contact angle analyses to determine its chemical composition, morphology and wettability properties. The PDA grafted disks that been subjected to 48 h refreshing time in SBF produced homogenous apatite formation with less agglomeration, closest theoretical Ca/P ratio and high hydrophilicity, suggesting the formation of preferable apatite layer with a reduction in the number of refreshing time.Bioactivity analysis in simulated body fluid (SBF) is an experiment or protocol conducted to evaluate the bioactive properties of a sample without involving cells. The bioactive property is claimed based on the formation of apatite layer after immersion in SBF. This analysis consumes expensive chemical reagents and requires complex procedure in preparing and refreshing the solution. Therefore, the aim of this study was to identify significant alteration of refreshing time in the 1.5× SBF to form an apatite layer on a polydopamine (PDA) grafted stainless steel (SS316L) disk. The SS316L disks were pre-treated and grafted with a PDA layer to equip the bioinert metal surface with a bioactive film. The PDA grafted disks were subjected to bioactivity analysis in SBF for 7 days at different refreshing time (24 h, 48 h, 72 h and not refreshed up to 7 d). The surfaces were then characterised by FTIR, SEM-EDX, and contact angle analyses to determine its chemical composition, morphology and wettability properties. The PDA grafted disks that been subjected to 48 h refreshing time in SBF produced homogenous apatite formation with less agglomeration, closest theoretical Ca/P ratio and high hydrophilicity, suggesting the formation of preferable apatite layer with a reduction in the number of refreshing time.
Effect of Hydroxyapatite: Fibroin Ratio on Hydroxyapatite/Fibroin/Chitosan Porous Scaffold Characteristics
Authors: Wattanutchariya Wassanai , Chaijaruwanich Anirut , Sukhachiradet Tarin
Published: August 2016

Autografting is a bone replacement technique used in orthopedic surgery. Bone tissue engineering is a new technique that offers promise, and could help alleviate this risk. Bioceramics, biopolymers or composite can be fabricated for artificial bone scaffold and used for bone regeneration. This study used three types of biomaterials – hydroxyapatite (HA), fibroin, and chitosan – to form porous scaffold. HA and fibroin were prepared from natural materials. HA was synthesized from mollusk shell by wet chemical precipitation method, while silk fibroin was extracted from silk worm’s cocoons. The HA and fibroin were mixed in a variety of ratios along with a fixed amount of chitosan before fabricating composite porous scaffolds by freeze-drying. The resulting scaffolds were evaluated for biodegradability, biocompatibility, porosity pore morphology and mechanical property. The fabricated scaffolds had an interconnected porous structure with a pore size of 200-400 μm and porosity in a range of 93-95%. The average degradation rate of the scaffold in lysozyme was between 7-17% at 7 days. A biocompatibility test showed that the scaffold was non-cytotoxic, making it a good candidate for future bone tissue engineering applications.
Modeling the Heat of Hydration of Concrete Incorporating Fly Ash
Authors: Lu Zheng Gang , Wang Xiu Xin
Published: August 2016

The hydration evolution of concrete with different water-binder ratios and fly ash replacement percentages are studied by experimental investigation. Based on equivalent age concept, the effect of water-binder ratio as well as fly ash dosage on the ultimate temperature rise and heat release coefficient are analyzed with the hyperbolic-type calculating model of adiabatic temperature rise adopted. It is indicated that the adiabatic temperature rise will be reduced with the increase of water-binder ratio and the incorporation of fly ash. The hydration evolution process will be accelerated with the decrease of water-binder ratio, but slowed down when the amount of fly ash is enhanced.
How to Increase Plastic Waste Acceptance for Mechanical Recycling: An Introduction to Material Value Conservation and its Phenomenon
Authors: Gabriel Djoko Sihono
Published: August 2016

Inappropriate packaging design and implementation of quality improvement of plastic waste paradigm affected low acceptance of waste for mechanical recycling. This research proposed material value conservation paradigm with design for recycling principles as key solution in avoiding its value degradation. Phenomenology and plastic quality measurement implemented as methodologies of research. Some evident in Indonesia verified the presence of the new paradigm in practice and followed with estimation of its prospective benefit. The new paradigm will generate broader impact and more benefit if adopted for other type of materials, especially for region with high density of people and high consumption rate of conserved products.
Remediation of Raw Wastewater of Palm Oil Mill Using Activated Cow Bone Powder through Batch Adsorption
Authors: Adeleke Abdul Rahman Oyekanmi , Abdul Latiff Ab Aziz , Daud Zawawi , Ridzuan Baharudin , Mat Daud Nur Falilah
Published: August 2016

The most critical parameter of palm oil mill effluent (POME) is chemical oxygen demand (COD mg/L). The adsorption of COD mg/L from raw POME using activated cow bone powder has been investigated. The raw POME contains 4.786 g/L of COD, which has to be treated effectively before discharge. Batch experiments were conducted at fixed condition of pH, contact time and speed at different weight dosages for different particle sizes of 75, 150 and 300μm. The result obtained showed a similar adsorption pattern for the particle sizes, the optimum removal was obtained at 150 μm at 0.025g/L with 71% removal efficiency, there was no further significant diference after the adsorption at this stage. The BET adsorption model was adopted to describe the experimental isotherm and isotherm constants for the optimum particle size. The equilibrium data fitted well to the BET model. The hydrophobic behaviour of the CBP proved by the WDPT analysis influenced the removal of COD mg/L on CBP.
Cure and Mechanical Properties of Natural Rubber Filled Bacterial Cellulose
Authors: Vudjung Chaiwute
Published: August 2016

Natural rubber (NR) containing the nata de coco fiber or Bacterial cellulose (BC) was prepared by co-coagulation of BC and concentrated NR latex with CaCl2 and compounded by two roll mill. The effect of BC content was the important factor in this study. It was that found tensile strength and elongation at break of NR filled BC (NR/BC) decreased with increasing BC content. The addition of BC into NR affect Mooney viscosity of NR/BC masterbatch, with increasing BC content, scorch time and cure time of their compound decreased.
Compatibilization Efficiency of Polybutadiene-Grafted Maleic Anhydride in Ethylene-Propylene Diene Rubber/Epoxidized Natural Rubber Blends
Authors: Prasertsri Sarawut , Nuinu Pranee , Srichan Sansanee , Radabutra Siriwat , Vudjung Chaiwute , Boonyod Saowaluk
Published: August 2016

This research aims to investigate the efficiency of polybutadiene-grafted maleic anhydride (PB-g-MAH) as the compatibilizer for ethylene-propylene diene rubber and epoxidized natural rubber (EPDM/ENR) blends. PB-g-MAH was varied from 0-10 parts per hundred parts of rubber (phr), and the cure characteristics, mechanical and dynamic properties of 70/30 EPDM/ENR blends with and without compatibilizer were evaluated. It was found that the minimum torque, maximum torque, scorch and cure times of the blends increased after adding PB-g-MAH, whereas cure rate decreased. The morphology of the blend is improved by the addition of PB-g-MAH in small amounts, owing to an improved compatibility of these rubbers confirmed by dynamic mechanical property. The hardness and oil resistance increased with increasing PB-g-MAH content. Of all blends investigated, the blend compatibilized with 2-4 phr of PB-g-MAH shows the optimum mechanical properties and thermal resistance.
Modification of Used Palm Oil: Preliminary Study of its Potentiality as Polyurethane Foam Precursors
Authors: Riyapan Duangporn , Saetung Nitinart , Saetung Anuwat
Published: August 2016

Polyol was successfully synthesized from used palm oil (UPO) via epoxidation and ring opening reaction. The mole ratio of UPO: formic acid: hydrogen peroxide was 0.3: 8: 1.5. The reaction had been continuously stirred at 400 rpm at 65°C with varied reaction time for 0.5, 1.0, 1.5, 2.0, and 4.0 h. The chemical structure of modified used palm oil (MUPO) or polyol was confirmed by 1H-NMR. OH number of polyols increased with an increase reaction time. Moreover, the preliminary study for the preparation of MUPO-based polyurethane (PU) foam was performed. A new MUPO-based PU foam was successfully prepared and theirs foam behaviors were investigated.
Poly(Vinyl Alcohol) (Core)-Polyurethane (Shell) Nanofibers Produced by Coaxial Electrospinning
Authors: Park Ga Young , Lee So Young , Kim Woo Jin , Choi Jin Hyun
Published: August 2016

Nanoweb fabricated by electrospinning has a large specific area and a small pore size which can be controlled through a spinning process to enable a strong adsorption and selective permeability. It is required to produce nanofiber of different polymer mixture with a limited miscibility for improvement of physical, chemical, or biological properties. In this study, poly (vinyl alcohol) (PVA)/polyurethane (PU) nanofibers were produced by coaxial electrospinning. PVA (core)/PU (shell) nanofibers were defect-free and had a uniform thickness. The pseudo core/shell structure of PVA/PU nanofibers was confirmed by transmission electron microscopy. The presence of PVA and PU in the nanofibers was identified by 13C solid state nuclear magnetic resonance spectroscopy, fourier transform infrared spectroscopy, and X-ray diffraction analysis. Water contact angle was reduced by incorporation of PVA in a core of PU nanofiber. For variety of biomedical applications, bioactive substances such as antibiotics and proteins can be incorporated in a core of hydrophobic PU nanofiber by coaxial electrospinning of water-soluble polymer/bioactive substance mixture.
Effect of Carbon Black Substitution with Raw and Modified Bentonite on the Thermal Aging Resistance of Natural Rubber Composites
Authors: Garing Clare , Pajarito Bryan B.
Published: August 2016

The effect of carbon black (CB) substitution with raw (BNT) and modified (M-BNT) bentonite on the thermal aging resistance of natural rubber (NR) composites was investigated in this study. NR composites were prepared at varied proportions of CB, M-BNT, and BNT using a three-component, third degree simplex lattice mixture design of experiment (DOE). M-BNT was produced by modifying sodium-activated bentonite with tetradecyldimethylamine (TDA) salt and cocamide diethanolamine (CDEA). Thermal aging was performed at 70 and 100°C for 168 and 336 h. Substitution of CB with 5 phr M-BNT gave the highest values of tensile properties (modulus and strength) for both unaged and aged samples. This is attributed to the synergistic effect of CB and M-BNT fillers on the tensile properties of NR composites. In terms of property retention (%), composites filled with M-BNT and BNT clay fillers attained the highest values which signified their excellent thermal aging resistance. This observation proves the barrier effect of clay platelet structure which hinders oxygen diffusion in the rubber. Reduced hierarchical models as function of CB, M-BNT, and BNT proportions were used to generate contour plots for tensile properties of NR composites after 168 h of aging at 70 and 100°C.
Effects of Gamma Radiation on Thermal and Mechanical Properties of Wood-Flour Filled Polybenzoxazines
Authors: Tiptipakorn Sunan , Puengbankoh Ketsarin , Rimdusit Sarawut , Suwanmala Phiriyatorn , Hemvichian Kasinee , Matchariyakul Nuanjan
Published: August 2016

In this study, the composites for wood substitution made of benzoxazine filled with rubber wood-flour were fabricated. The wood flour contents was varied from 0 to 30 wt%. The effects of gamma radiation on the thermal and mechanical properties of wood-flour filled polybenzoxazine were determined. The different radiation dose (i.e. 0, 10, 20, and 30 kGy) was applied to the fabricated samples. The differential scanning calorimeter (DSC) and thermogravimetric analyzer (TGA) were used to evaluate glass transition temperature (Tg) and degradation temperature (Td), respectively. While the flexural strength was determined using Universal Testing Machine (UTM). It could be noted that the increase of radiation dose provided the decrease of Td. Moreover, the values of Tg, flexural strength, and water absorption reveals the similar trend with the maximum point at 20 kGy of radiation dose.
Improvement on Surface Tracking and Tensile Stress of Insulator via the Used of Aluminium Oxide Filler
Authors: Nilbunpot Nutsopin , Suksri Amnart
Published: August 2016

Mechanical effect is one of many causes that influence surface tracking activity of electrical insulation. Mechanical stress is also a main cause that deteriorates the property of cable spacer used in delivered electrical power through transmission line. This paper investigates on surface tracking and tensile stress performance of composite insulator material in order to improve insulator property. Specimen were made from epoxy resin and additive fillers tested under the condition of contamination. The filler ratio were used from 0 to 50% with incremental of 10%.The result showed that fillers have significance improvement on inhibition of the degradation on insulators when the concentration of filler is increased, the tracking time has increased until 40% of filler. Moreover, the improvement on the tensile stress is also increased. It is clearly showed that addition of filler not only improve on the time for surface tracking on insulator surface but also helps improve on mechanical stress property of insulators as well.
The AOTF-based NO2 camera
Authors: Dekemper Emmanuel , Vanhamel Jurgen , Van Opstal Bert , Fussen Didier
Published: August 2016

Abstract. The abundance of NO2 in the boundary layer relates to air quality and pollution sources monitoring. Observing the spatio-temporal distribution of NO2 above well-delimited (flue gas stacks, volcanoes, ships) or more extended sources (cities) allows for several applications: monitoring emission fluxes or studying the plume dynamic chemistry and its transport. So far, most attempts to map the NO2 field from the ground have been made with visible-light scanning spectrometers. Benefiting from a high retrieval accuracy, they only achieve a relatively low temporal resolution that hampers the detection of dynamic features. We present a new type of passive remote sensing instrument aiming at the measurement of the 2-D distributions of NO2 slant column densities (SCD) with a high spatio-temporal resolution. The measurement principle has strong similarities with the popular filter-based SO2 camera as it relies on spectral images taken at wavelengths where the molecule absorption cross-section is different. Contrary to the SO2 camera, the spectral selection is performed by an acousto-optical tunable filter (AOTF) capable of resolving the target molecule's spectral features. The NO2 camera capabilities are demonstrated by imaging the NO2 abundance in the plume of a coal-fired power plant. During this experiment, the 2-D distribution of the NO2 SCD was retrieved with a temporal resolution of 3 minutes and a spatial sampling of 50 cm (over a 250 x 250 m2 area). The detection limit was close to 5 x 1016 molecules cm−2, with a maximum detected SCD of 4 x 1017 molecules cm−2. Illustrating the added-value of the NO2 camera measurements, the data reveal the dynamics of the NO to NO2 conversion in the early plume with an unprecedent resolution: from its release in the air, and for 100 m upwards, the observed NO2 plume concentration increased at a rate of 0.75–1.25 g s−1. In joint campaigns with SO2 cameras, the NO2 camera could also help in removing the bias introduced by the NO2 interference in the SO2 measurements.