bluuebunny/crossref_metadata_2025 huggingface dataset:
Leveraging Service Management to Achieve Sustainability Goals
Authors: Blanke Mark S. , Abraham Thomas
Published: November 2014

Information Technology can play a significant role in supporting and even driving sustainability strategies in an organization. However, many small and mid-size enterprises (SMEs) often separate their “Green IT” initiatives from existing business and IT strategy. The authors describe how one SME used IT service management (ITSM) to clarify and improve their IT services and to integrate sustainability into the IT function. Their case provides a detailed description of ITSM and also shows that ITSM offers a framework for SMEs to integrate sustainability into the IT operations.
Using an AHP Rating Model to Select a Suitable Approach to Intellectual Capital Management
Authors: Carlucci Daniela , Kujansivu Paula
Published: November 2014

Although a large number of models and tools for managing Intellectual Capital (IC) have been introduced in the literature, the practical operationalisation of IC management still remains challenging. In particular, how managers can better evaluate and select a proper IC management approach represents a critical issue. Selecting a suitable IC management approach is a complex decision-making problem which involves a set of factors affecting the choice. As many factors should be taken into account in that decision, the problem can be tackled using multi-criteria methods. Through a synthesis of management literature regarding the approaches to IC management and the factors affecting their choice, the paper develops an AHP rating model, which keeps in focus the most meaningful elements to be considered in making decision on IC management. The paper presents the results of the application of the model within a not-for-profit organization.
Towards Evaluating the Quality of Experience of Remote Patient Monitoring Services
Authors: Skorin-Kapov Lea , Dobrijevic Ognjen , Piplica Domagoj
Published: November 2014

The applicability of advanced mobile technologies in the m-Health domain has led to a number of studies and (limited) commercial products supporting delivery of health services to remote users. A key issue regarding successful delivery and acceptance of such services is meeting their Quality of Service (QoS) and Quality of Experience (QoE) requirements, focusing on technical aspects and end user perceived quality, respectively. In this paper, the authors address the topic of evaluating QoE for non-emergency remote patient monitoring services. They identify relevant QoE influence factors and metrics, and present the results of a QoE evaluation study, whereby they focus on usability aspects. The study involves 26 users testing a prototype version of the Ericsson Mobile Health service, which is based on a smartphone application and measurement of vital signs via medical sensors. The results show a strong correlation between QoE and: perceived effectiveness of the mobile interface (regarding both adequacy of smartphone screen size and smartphone application navigational support), perceived ease of conducting a blood pressure measurement task, and user motivation for service usage.
Habit
Authors: Yin Guopeng , Zhu Ling
Published: November 2014

Most IS studies considered post-adoption behavior as a cognitive process but rarely took a habitual perspective. The present study developed a research model to investigate the antecedents and effects of users' habit in the context of social networking websites (SNW). It used a two-stage survey and partial least squares (PLS) analysis to test the model. It found that a user's habit of using an SNW is developed through his prior usage, enjoyment, social interaction ties, and satisfaction, and that his habit consequently affects his online self-presentation desire and actual continued usage of SNW. The model accounts for 46.5% of the variance in SNW habit, and 33.5% of the variance in SNW continuance usage, respectively. This is one of the first studies that integrate the essential construct of habit with traditional cognitive, affective, and intentional factors into an SNW continuance model. The findings not only contribute to the theoretical development of IS continuance, but also provide insights for SNW practitioners to understand users' habit and develop sustainable strategies accordingly.
A Cognitive Heterogeneous Network Spectrum Resource Allocation Algorithm Based on User Needs Feedback
Authors: Liu Bai Hong , Hu Shian , Xu Zhe
Published: November 2014

Allocation of spectrum resource is the key for heterogeneous wireless networks. Taking the differences between different types of access networks available channel bandwidth and the communication requirements of users into consideration on the basis of cognitive heterogeneous network spectrum resource allocation algorithm based on graph coloring theory, this paper introduces bandwidth control parameter and proposes a spectrum resource allocation algorithm based on user needs feedback, which improves the utilization and fairness of system spectrum resources.
An Efficient Joint Subcarrier Pairing and Resource Allocation for Multi-Relay OFDM Systems
Authors: Liu Kai Ming , Ruan Chun Qing , Liu Yuan An , Cheng Xiao Yu , Liu Fang
Published: November 2014

For multi-relay orthogonal frequency division multiplexing (OFDM) systems, efficient subcarrier pairing and resource allocation are significant to boost the system performance. We study the joint optimization problem of subcarrier assignment, subcarrier pairing and power allocation, to maximize the system transmission rate under a total power constraint. Many previous works formulate such a problem as a mixed integer programming problem, then transform it into a convex optimization problem by continuous relaxation and pair all the subcarriers using Hungarian method, which requires high computation complexity. In this paper, we assign each subcarrier in both hops to the relay that has the highest channel gain on that subcarrier. Since the numbers of subcarriers assigned to each relay in both hops, denoted as n1(k) and n2(k), are probably different, we first sort the subcarriers in descending order and pair the front min {n1(k),n2(k)} subcarriers assigned to each relay in sorted way, then we assign and pair the remaining subcarriers using Hungarian method. Due to the decrease of matrix dimensions when using Hungarian method, the computation complexity of the suboptimal algorithm is reduced. Simulation results show that the suboptimal algorithm provides the similar performance to that of the optimal algorithm with much lower computation complexity.
Key Technology Research on Wireless Mesh Network MAC Protocol
Authors: Fan Wen Qi , Huang Sheng Chun , Wei Ji Bo
Published: November 2014

Wireless Mesh Networks (WMN) is distributed broadband wireless network architecture with characteristic of high throughput and high data rate. The quantity of research being conducted in this area has dramatically increased recently. Medium Access Control (MAC) is the key technology to exploit the multi-hop advantage of WMN. This paper introduces two major research topic of MAC design in WMN, the topology control and link scheduling. A survey of recent research on these topics is given in detail.
Behavior Measure Method Based on Clustering Algorithm
Authors: Wang Zhi Hao , Wang Xiao Ping
Published: November 2014

We introduce the clustering algorithm to the behavior measure, which can effectively detect the malicious behavior, and the simulation verifies the efficiency of the scheme. This method can be well applied to the user behavior measure under open network.
Technological Research on Information Extraction of Part Process Model Based on Machining Feature
Authors: Qu Li Gang , Zhou Hai Jun , Dong Zhi Liang
Published: November 2014

The information extraction mode based on machining feature was presented for studying information extraction of part process model in the 3D CAPP system. The classification and its data structure of machining feature were investigated for defining the matching rule about the features. The feature authentication were availably fulfilled by converting the correlations of geometric topological into surface-edge adjacency graph for the part model, and the corresponding parameters extraction of feature were derived from traversing the feature tree of application development CATIA. The whole feature recognition process and parameter extraction process can become more directly and effectively by adopting the method of comparing machining feature with the predefined feature matching rules of the feature database.
Research on the Anti-Rust Mechanism of T704
Authors: Yang Ben Ben , Fu Hong Rui , Wang Ben Li , Liu Shu Zhen , Yue Zhi Ge
Published: November 2014

The anti-rust mechanism of T704 is mainly studied in this paper.T704 was resolute in kinds of base oils to make anti-rust oils, and the effect of which were tested through some experiments, which indicated the humid heat test was good and the salt water immersion was bad. So it is concluded the protective film of T704 on the metal is main Chemisorption film.
Microstructure Characteristics and Surface Residual Stress of Iron-Based Alloy Coating by Laser Cladding
Authors: Wang Ying Zi , Zhao Yan Hua , Sun Jie
Published: November 2014

Laser cladding is an effective mean to repair the damaged components in remanufacture industry. The iron-based alloy coating was obtainment by laser cladding on grey cast iron (HT250). The microstructure and morphology of laser cladding were observed by using scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). The micro hardness of laser cladding coating was tested. The wear properties of grey cast iron and laser cladding coating at room temperature without lubrication were evaluated by sliding wear tests. The distribution regularity of surface residual stress of substrate and cladding coating was obtained. It was shown that the laser cladding coating on grey cast iron has a homogeneous and dense microstructure. It was observed that the laser cladding coating presents a great hardness and excellent wear resistance. Tensile stress was generated in the surface of laser cladding coating.
The Application of Riegl Laser Scanner in Topographic Survey
Authors: Song Yi Rong , Chen Guang Feng , Cheng Qian Yuan
Published: November 2014

Based on the Guobu topographic survey project in Laxiwa hydropower station at Yellow River, different models of Riegl laser scanning equipment were used to measure each testing area’s topography. Laser scanning measuring technique plays a great role in the process of the hydroelectric topographic survey, and its efficiency works several times higher than that of using traditional measuring means. Moreover, it also can shorten measurement period and reduce the field cost of production, which can achieve good economic benefits and social benefits consequently.
Research on the Influence of Deep Foundation Pit Excavation on Neighboring Buildings
Authors: Chai Wen Jing
Published: November 2014

With the development of society and economy, China's investment in construction projects is increasing, which requires the construction and management staff to improve their professional level, to develop a more scientific construction plan to ensure construction quality, and ultimately to the construction goal. Especially in deep foundation excavation process, it not only needs to upgrade the technological level of the excavation, but also needs to enhance the impact of researches on the approaching buildings to make the appropriate preparations to reduce adverse effects on the surrounding buildings, which meets the actual needs of construction, to ensure building construction safety. By exploring the impact of deep excavation on adjacent buildings, the paper makes the construction workers deeply understand the importance of deep foundation construction work.
Analysis of Technology and Quality Control Measures of Road Bridge Construction
Authors: Yang Ming , Wang Hui , He Feng , Liu Qing Min
Published: November 2014

This paper describes the importance of increasing control of technology and quality of road bridge construction and puts forwards effective measures to control the proposed road bridge construction technology and quality. Road bridge engineering is a basic livelihood projects while also ensuring economic and social development, but in recent years the reports about the quality of bridge construction repeatedly appeared in press which highlighting the poor construction quality control.
Finite Element Analysis and Stress Test of Quayside Container Crane
Authors: Ling Jun , Zhou Shao Ping , Wu Feng Qi
Published: November 2014

In present society, port container transportation is a basic need for the costal country. The quayside container crane plays a vital role in port transportation field. Taking 80t quayside container crane as the subject, the three-dimensional model of crane steel structure with plates was established;the element analysis by means of Workbench and multi-measuring points stress test of quayside container crane steel structure was carried out. The simulationresults werecompared with test results to prove the correctness of the model. On the basis, the strength, rigidity and fatigue property of the crane was analyzed. Finally, some design and manufacture suggestions about craneswere given.
Nature Gas Station Control System Design Based on Automatic Monitoring and Control Theory
Authors: Bai Shu Sen , Liu Feng Yun , Feng Zhi Cheng
Published: November 2014

Nature gas is an important fuel. How to measure the gas amount precisely and how to utilize the gas properly, how to distribute the gas and how to calculate the fees of the gas are very significant to enhance economical benefits in the gas distributing station. In the designed control system, Computers are used in the measurement of the gas to compensate auto-online computation and calculate the flux of the gas automatically in the standard state .The system is provided with the function of the gas pressure adjustment, the charging and discharging the gas in the gas-globe-jar, the starting and stopping of the compressor, diagnosing the system failure, technical parameter over threshold alarming and the chain-protection of the system. The combination control software are used in the design to collect the data, monitor and control the objects in the system, so it is provided with convenience in operation and maintenance, and dynamical man-computer interface..
Study on Virtual Scene Technology and Motion Simulation
Authors: Li Shan Feng
Published: November 2014

The study on virtual scene technology began in the 1950 s, and virtual scene technology is widely applied in game, GIS and virtual experiment. Motion simulation technology is widely applied in industrial control and machinofacture. The combination of virtual scene and motion simulation not only has accuracy and real-time, but also has interaction and immersion. The paper uses visual simulation platform of vehicles ESP experiment as the application background, and discusses the problems including communication and data conversion appearing in the cohesion of virtual scene and motion simulation technology.
Finite Element Simulation Analysis of Micro Thermoelectric Switch Structure
Authors: Ping Chuan , Zhang Rui , Xue Yan , Fu Dong Xiao , Li Hui , Du Zhen Hua
Published: November 2014

Considering of the thermal resistant of metal Ni-Cr, as well as the insulating characteristic of SiO2 membrane, aluminium electric line, energetic material, solder and other materials, we designed three MEMS thermo-electric switches, which can realize On-Off (or Off-On) transition to control the initiation of weapon system. We also simulated and analyzed the static and the transient thermal processes and the stress analysis of switches using finite element simulation analysis (FEA) tool ANSYS. The results of temperature distributing, transient response and stress distributing have been obtained.
Research on the Two-Direction Optimization of Shafting Alignment Using Invasive Weed Optimization
Authors: Cai Yao Quan , Zeng Fan Ming , Liu Jin Lin
Published: November 2014

In view of the present shaft alignment to optimize focused on one-way location optimization, and less the method for shaft alignment optimization. By MATLAB invoking ANSYS, the finite element method is combined with intelligent algorithm, which is used to optimization calculation for shaft test platform. In the calculation, the minimum stern shaft bearing load as the goal, the vertical shaft bearing and axial location is optimized based on a new intelligent optimization algorithm-invasive weed algorithm. Compared with the linear programming and genetic algorithm, the results showed that the invasive weeds algorithm has better global optimization ability. ANSYS simulation combined with MATLAB can provide a new approach for shafting design, shafting alignment and vibration calculation.
Research on the Control Strategy of Eye-to-Hand Target Track Real-Time Tracking System
Authors: Zhang Jia Xin , Yao Xiao La , Miao Jiang Tao
Published: November 2014

This paper presents an Eye-to-hand system, designed for hand-eye system presents a automatically real-time tracking of moving targets control strategy. The first strategy uses a color mark on the target, the use of binocular stereo vision system for color measurement and then in the visual system of the target three-dimensional reconstruction to give the three-dimensional coordinates in the visual coordinate system when the target position and orientation when changes according to the amount of change in the three-dimensional coordinates of the direct control of the robot arm motion of each joint, enabling the tracking of moving targets.
Research on the Computer Graphic Design and Visual Communication Design
Authors: Huang Jian Wen
Published: November 2014

With the development of computer processing software and related technology, modern television, advertising, games, software and commercial activities have made extensive use of computer image processing software for graphic design and visual communication design. The works designed by these means have a strong infection, clear characteristics and it is easy to impress viewers. And the works designed by these means have a high degree of art innovation and also have a positive and profound significance on the creators. This paper analyzed and discussed the computer-based graphic design and visual communication design and their related applications.
Expert System of Fault Diagnosis for Flight Simulator Based on Fault Tree Analysis
Authors: Li Gang , Ba Zhen Guo , Zhang Hong Zhi
Published: November 2014

Aiming at the problems existing in maintenance of flight simulator, considering characteristics of expert system, the architecture and fault diagnosis methods of flight simulator, the structure and key realization technology for flight simulator fault diagnosis expert system are studied; the flight simulator fault diagnosis expert system design proposal is completed. Research on transforming from fault tree pattern to rule and diagnosis knowledge representing are emphasized, expert system knowledge base is constructed by means of frame plus production knowledge representing method, then certainty and rule based backward chaining inference engine with depth-first and heuristic search mechanism is designed, the system diagnosis flow and inferring flow are also developed in this paper. Finally the expert system is tested by a fault solving demonstration.
Alumina High Pressure Dissolving Temperature Object Model Identification
Authors: Zhang Quan Jun , Chen Yan , Huang Hao Yue , Liu Lei , Zhang Kuang Wei
Published: November 2014

In the process of high pressure dissolving by Bayer process, High Pressure Digestion Slurry with temperature is the main factor which influencing the percentage of dissolved Al203. Research on temperature model of digesting rarely published; parameter setting and control difficult to achieve desirable effect. In the matlab platform, system identification method, according the output error model to identify model, finally determine the model of alumina High-pressure dissolving temperature model. The recognition results showed that: Step response curve of the second-order model is fitted basically with the online temperature trace which collected by alumina High-pressure digestion in ZHONG ZHOU BRANCH CHALCO, degree of fitting is 86.27%; Algebraic stability criterion verifies that: the root of the system equations are negative, it’s stable. The identification model is reasonable and effectual, provide models for parameter setting and control; improve the control accuracy and percentage of dissolved Al203, reduce energy consumption.
Influence of Electrochemical Etching Parameters on Morphology of Porous Silicon
Authors: Liu Lan , Xue Yan , Ren Xiao Ming , Xie Rui Zhen
Published: November 2014

In order to protect porous silicon from break and enhance it’s porosity and specific surface area, porous silicon is prepared with electrochemical etching method. The charateristic of porous silicon is investigated with SEM and high-speed adsorption surface area and porosity analyzer. The results show that the porous silicon prepared with the method of gradient etching and control of etching time is mechanically stable. The porosity and specfic surface area are improved.
Investigation on Properties of MEMS Based Micropyrotechnic Igniter
Authors: Xue Yan , Ping Chuan , Zhang Rui , Ren Xiao Ming , Liu Lan , Xie Rui Zhen
Published: November 2014

Micro-electro-mechanical system (MEMS) have recently seen their field of application extended to military. This is mainly due to the fact that MEMS technologies present a great to reduce the mass, cost, power consumption, while improving the reliability, performance and smartness. Application of MEMS technology, the micropyrotechnic igniter are produced.The principle is based on the integration of the potassium salt of 7-hydroxy-4,6-dinitro-5,7-dihydrobenzofuroxanide (KDNBF) material within a micropyrotechnic igniter, which is produced by MEMS with 3 by 3 micro-igniter. Each igniter contains three parts (the igniter chip, silicon chamber, KDNBF). One import point is the optimization of the igniter process obtaining Ni-Cr bridges with about 13Ω and Al bridges with about 350Ω, which are triggered by electrical power delivered to KDNBF. The resistance of Ni-Cr and Al bridges is used to sense the temperature on the KDNBF which are in contact. The other one point is firing testing of micropyrotechnic igniter. The ignition performance of micropyrotechnic igniter array are tested that including Ni-Cr bridges of the 50% sensitivity on voltage, current ignition is 10.83V,0.26A; including Al bridges of the 50% sensitivity on current ignition is 0.176A; the ignition of voltage is unstable. The experimental results will deeply contribute to the micropyrotechnic system. This paper will discuss all these point.
Effect of Particle Size on Carbonate Apatite Cement Properties Consisting of Calcite (or Vaterite) and Dicalcium Phosphate Anhydrous
Authors: Cahyanto Arief , Toita Riki , Tsuru Kanji , Ishikawa Kunio
Published: November 2014

Calcium carbonate (CaCO3) has been known as one of the components of carbonate apatite (CO3Ap) cement. Calcite is one of the polymorph of CaCO3 with big particle size and excellent stability. In contrast, vaterite has small particle size and a metastable phase. To discover the effect of particle size on the properties of CO3Ap cement, this study investigated the different particle size of vaterite; calcite from vaterite, which has almost similar particle size and shape with vaterite; grounded calcite and ungrounded calcite. The powder phase of calcite or vaterite combined with dicalcium phosphate anhydrous (DCPA) was mixed with 0.8 mol/L of Na2HPO4 solution in 0.45 liquid to powder ratio. The paste was packed into a split stainless steel mold, covered with glass slide and kept at 37°C and 100% relative humidity for a period of time. XRD and FT-IR analysis revealed that CO3Ap cement consisted of vaterite and DCPA transformed to pure B-type CO3Ap in 72 hours while CO3Ap cement that consisted of calcite with different particle size was not completely transformed to CO3Ap even until 240 hours. We concluded that CO3Ap cement consisted of vaterite with small particle size and metastable phase properties is more effective as starting material due to its fast transformation to CO3Ap.
Fabrication of Bioactive Polylactic Acid Composite Formed by 3D Printer
Authors: Karashima Ryoki , Yabutsuka Takeshi , Yao Takeshi
Published: November 2014

We precipitated Apatite Nucleus (AN) by raising pH of SBF. We mixed various concentration of AN in polylactic acid (PLA) and pressed by uniaxial press and cold isostatic press. We investigated the effect of AN concentration on bioactivity. We fabricated composite of PLA and AN configurating the shape by using 3D printer. The composite showed high bioactivity.
Magnetic Properties of Mg0.4Ca0.6Fe2O4 Nanoparticles Synthesized by Sol-Gel Method for Hyperthermia Treatment
Authors: Escamilla-Pérez A.M. , Cortés-Hernández D.A. , Almanza-Robles J.M. , Mantovani D. , Chevallier P.
Published: November 2014

Powders of Mg0.4Ca0.6Fe2O4were prepared by sol-gel using ethylene glycol and Mg, Ca and Fe nitrates as starting materials. Those powders were heat treated at different temperatures (300, 400, 500 and 600 °C) for 30 min. The materials obtained were characterized by X-ray diffraction (XRD) and vibrating sample magnetometry (VSM). The Ca-Mg ferrite with the most appropriate magnetic properties was further analyzed by transmission electron microscopy (TEM). The heating capability of the nanoferrites was also tested via magnetic induction. The XRD patterns of these Ca-Mg ferrites showed a cubic inverse spinel structure. Furthermore, neither traces of hematite nor orthorhombic Ca ferrite phases were detected. Moreover, all the Ca-Mg ferrites are superparamagnetic and the particle size distribution of these Ca-Mg magnetic nanoparticles exhibits an average diameter within the range of 10-14 nm. The needed temperature for hyperthermia treatment was achieved at around 12 min.
Bone Substitutes as a Drug Delivery of Antibiotics
Authors: Ganz Cornelia , Gerber Thomas
Published: November 2014

The aim of the present study was the in vitro investigation of a synthetic bone graft substitute loaded with individual antibiotics for the treatment of osteomyelitis and infectious bone disease. The elution of gentamicin, an aminoglycoside antibiotic, from the NanoBone® products NanoBone® S granules (NBG) and lyophilized NanoBone® (NBP) putty was tested over a period of one week. An indirect photometrically-based detection system was used to measure the released antibiotic concentration. Both materials showed very different release behaviour. After one day lyophilized NanoBone® putty delivered 100% of the gentamicin value, whereas NanoBone® S granules released one-fifth of the used gentamicin level.
Fabrication of Hydroxyapatite Microcapsule Containing Vitamin B12 for Sustained-Release
Authors: Yabutsuka Takeshi , Iwahashi Kazuma , Nakamura Hiroki , Yao Takeshi
Published: November 2014

When either the pH or temperature of simulated body fluid (SBF) are raised, fine particles of calcium phosphate are precipitated. We found that these fine particles actively induce hydroxyapatite formation from body fluid or SBF and named the particles Apatite Nuclei. In this study, we fabricated hollow hydroxyapatite microcapsules by using Apatite Nuclei. We inserted vitamin B12 in the hollow microcapsule and examined thesustained-release properties.
Effects of Albumin Adsorption on Cell Adhesion in Hydroxyapatite Modified Surfaces
Authors: Côrtes Juliana , Mavropoulos Elena , Hausen Moema , Rossi Alexandre , Alves Gutemberg
Published: November 2014

Synthetic hydroxyapatite (HA) is a widely used ceramic biomaterial due to its well described biocompatibility. Some modifications in HA surface can be made to increase surface porosity. Likewise, HA can be modified by the coating with proteins, which may impact on biocompatibility. In this work, we aimed to evaluate the impact of two surface modifications – coating with albumin, a major serum protein, and augmented porosity - over osteoblast adhesion on stoichiometric HA discs. Dense HA discs were obtained by pressing HA powder at 30 KN and sinterization at 1000°C, while porous HA was molded after the addition of alginate (15:1), followed by thermal treatment. Protein adsorption was attained by incubation on 0.5mg/mL bovine serum albumin (BSA) for 24 h at 37°C. MC3T3 mouse preosteoblasts were seeded over both protein-coated and uncoated dense or porous tablets, and cell viability after 24 h was estimated by XTT and Neutral Red assays. Cell density was quantified by fluorescence microscopy. While both dense and porous discs presented altered surfaces after protein treatment, as observed by scanning electron microscopy, porous HA tablets presented significantly higher levels of adsorbed protein. There was a decrease in the concentration of calcium ions in all samples analyzed. Porous HA treated with protein presented significant higher mitochondrial dehydrogenase activity (XTT) than non treated tablets (p<0.001). Although the BSA adsorption didn`t affect cell adhesion, the results obtained in fluorescence quantification suggests that de dense surface was best for cellular adhesion and spread than the porous one. We conclude that differences in the topography of a biomaterial can directly influence their ability to adsorb proteins, while the dense surface was more favorable for both the adhesion and the spreading of pre-osteoblasts.
Real-Time Evaluation of the Effects of Dexamethasone on Osteoblasts Using Dual Labeling with Fluorescent Probes
Authors: Ohsugi Hitomi , Hatsukawa Junichi , Takahara Masahiro , Aizawa Mamoru , Kanzawa Nobuyuki
Published: November 2014

Similar to other glucocorticoids, dexamethasone (DEX) induces osteoblast differentiation. At high concentrations, glucocorticoids may induce osteoporosis as a side effect. However, the exact mechanism of these two opposing effects has not been elucidated. To understand the mechanism of DEX-induced osteoblast differentiation, we developed a real-time osteoblast differentiation detection system using dual labeling of cells with fluorescent proteins. The promoter sequences of type I collagen and osteocalcin were ligated with mCherry and green fluorescent protein (GFP), respectively. Type I collagen is an early marker of osteoblast differentiation, and osteocalcin is a terminal differentiation marker. We investigated the effects of DEX on cell proliferation and differentiation using cells transformed with both constructs. Low DEX concentrations (<10 μM) induced calcification, as determined by alizarin-red staining, whereas calcification was inhibited at higher concentrations (>100 μM). Consistent with these results, mCherry-associated red fluorescence as an early marker was evident under both conditions, whereas green fluorescence associated with terminal differentiation was evident only at lower DEX concentrations. The level of green fluorescence diminished in a DEX-concentration-dependent manner. Thus, DEX does not inhibit the early stages of osteoblast differentiation but instead inhibits terminal differentiation.
Ex Vivo Model for Percutaneous Vertebroplasty
Authors: Oliveira M.T. , Lucena S. , Potes J. , Queiroga M.C. , Rehman S. , Dalgarno K. , Ramos A. , Reis J.C.
Published: November 2014

The testing of novel biomaterials for percutaneous vertebroplasty depends on suitable animal models. The aim of this study was to develop ex vivo a reproducible and feasible model of percutaneous vertebroplasty, for ulterior application in vivo. A large animal model was used (Merino sheep), due to its translational properties. Vertebroplasty was performed under tactile and fluoroscopic control, through a bilateral modified parapedicular access in lumbar vertebrae (n=12). Care was taken in order to avoid disruption of the vertebral foramen. The average defect volume was 1234±240 mm3. This mean volume ensures practical defects to test novel injectable biomaterials. 6 vertebrae were injected with a commercial cement (Cerament®, Bone Support, Sweden). Adequate defect filling was observed in all vertebrae. All vertebrae were assessed by microCT, prior to and post defect creation and after biomaterial injection. All vertebrae were mechanical tested. No mechanical failure was observed under loads higher than the physiological. Ultimately, this model is considered suitable for pre-clinical in vivo studies, mimicking clinical application.
Elastic Blocks: Hydrogel-Embedded Granules as Bone Grafting Substitutes
Authors: Zaage Franziska , Dau Michael , Ganz Cornelia , Frerich Bernhard , Gerber Thomas
Published: November 2014

NanoBone®Block is the alternative to autogenous bone blocks and offers doctors a rapid, simple operating procedure in combination with a low risk of complications. Aim of this work was to develop a bone grafting block with elastic properties for dental and orthopedic surgery which is ready to use. An easy handling has to be connected with quick regeneration. Therefore, NB granules have been combined with an elastic hydrogel carrier based on Polyvinylpyrrolidone (PVP) and silica sol. Mechanical properties were optimized for an enhanced handling by cross linking and simultaneous sterilization of the PVP with gamma radiation. Cross linked PVP has the capability of swelling in water without being solved. To approve biocompatibility of adjusted material anin vivostudy was analyzed using a standardized bone defect model in rat tibiae. Defect was filled with elastic bone grafting material. After 21 and 63 days rats were sacrificed and tibias analyzed. Histomorphological analysis showed an increased bone formation but even a decelerated resorption of elastic biomaterial. Quantitative compositional analysis showed a decrease in silicon content of granules as a process of matrix change.
Bone Induction in Porous HAp Block Modified by Partial Dissolution-Precipitation Technique with Supersonic Treatment in Rat Scalp
Authors: Murata Masaru , Akazawa Toshiyuki , Minamida Y. , Kabir Md. Arafat , Hino J. , Nagayasu H. , Ito M. , Sakamoto M. , Nakajima T.
Published: November 2014

Microcracks and trabecular fractures can be observed in physiological bone. Biomimetic hydroxyapatite (HAp) scaffolds have been strongly needed in bone regenerative medicine. We have been developing the combination method of the partial dissolution-precipitation techniques involving the stirring-supersonic treatment in 1.7×10-2 N HNO3 solution containing Ca2＋and PO43- ions to improve the surface and the bulk of commercially available synthetic HAp block (82.5% in porosity, 50-300µm in macropore). The modified HAp was named as a partially dissolved and precipitated HAp (PDP-HAp). The aims of this study are to characterize the PDP-HAp and to observe cell response for the ceramics in rat scalp tissue. The PDP-HAp exhibited the macropore sizes of 50-200µm, the porosities of 85-90%, and the specific surface areas of 1.0-2.0 m2･g-1, with many micro-cracks. Twenty rats were divided into 2 groups. At 9 months, bone induction occurred inside the many pores in the PDP-HAp group, while bone and cartilage were not found in the HAp group. We believe that osteoinduction by the PDP-HAp is different from the process of BMP-loaded HAp-induced bone formation. The PDP-HAp might be applied as potential ceramics with osteoinductive properity and excellent biocompatibility in difficult bone regenerative cases.
Evaluation of Sr- and/or Mg-Containing Hydroxyapatite Behavior in Simulated Body Fluid
Authors: Stipniece Liga , Salma-Ancane Kristine , Putnins Andris , Berzina-Cimdina Liga
Published: November 2014

The main goal of this study was to evaluate the behavior of Sr- and/or Mg-containing hydroxyapatite (HAp) bioceramics in simulated body fluid (SBF). Sr-and/or Mg-containing HAp powders were synthesized by modified wet chemical precipitation method. Sr-and/or Mg-containing HAp bioceramics were prepared by uniaxial pressing of the precipitated powders and subsequent sintering at 1100 °C for 1 h. The synthesis products were characterized in terms of chemical, phase and molecular composition. Influence of the substitutions on thermal stability, morphology and microstructure of the HAp products were evaluated. Results suggest that incorporation of Sr (up to 1.45 wt.%) in HAp structure induced an increasing of particle sizes, but incorporation of Mg (up to 1.05 wt.%) led to a reduction of particle sizes of the HAp powders. The ability to simultaneously release bioactive ions and the apatite-formation ability of the Sr-and/or Mg-containing HAp bioceramics were evaluated through immersing the samples in SBF for different time periods. Ca ions release and apatite-formation ability on the surfaces of the Sr-and/or Mg-containing HAp bioceramics in SBF depends on Sr and/or Mg concentration in the samples.
Apatite-Forming Ability of ZrO2 Ceramics Enhanced by Sandblasting and Chemical Treatment and the Influence on Mechanical Properties
Authors: Kolafová M. , Nežiková A. , Kamprle J. , Strnad J. , Strnad Z.
Published: November 2014

The apatite-forming ability of zirconia ceramics subjected to various surface treatments was investigated. Zirconia samples (Y-TZP) in the form of disks and rods were sandblasted and chemically etched in strong acids (HF, H3PO4, H2SO4) and/or in NaOH solution at an elevated temperature. The surface properties were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), wettability and roughness measurement. The ability to form bone-like apatite on the surface was evaluated by immersion of the sample in simulated body fluid, which has ion concentrations nearly equal to the inorganic part of human blood plasma. The effect of applied surface treatment on mechanical properties was investigated. Sandblasting resulted in significant increase of roughness. Chemical etching in H3PO4and H2SO4caused reduction of contact angle but this effect was lost when subsequent alkali treatment was applied. Etching in NaOH, H2SO4and two-step treatment combining H2SO4or H3PO4with NaOH resulted in the formation of bone-like apatite after immersion in simulated body fluid. These results indicate that sandblasted and chemically etched zirconia may be capable of direct bonding with living bone through an apatite layer created on its surface in a human environment. To avoid possible mechanical failure sandblasting conditions need further optimization.
The Innovative Design of Suspension Cast Components of Vehicles Made from High-Strength AlZnMgCu Alloy Resistant to an IED Type Threat
Authors: Żuczek Robert , Pysz Stanisław , Sprawka Piotr , Muszyński Tomasz
Published: November 2014

The new research trends are moving away from research works that are not directly connected with industrial applications. The Integrated Computational Materials Engineering (ICME) is an excellent example of the relationship between scientific research and the industrial sector.As an example of the design development of construction of a suspension component, an overview of the changes of a welded part replaced with cast component is presented. The identification of boundary conditions and forces operating on the nodes of the suspension element allowed determining the critical areas in the existing welded construction. Then the new design of casting for high performance applications was developed. Analysis of the kinematics of the suspension components also revealed the need for changes in the design of the mounting points of the suspension components to reduce the maximum values ​​of forces and enforced moments. As a result of successive stages of the topology optimization of analysed cast, control arms with significantly lower values ​​of maximum stresses were obtained. The material conversion of welded part with high strength AlZnMgCu aluminium alloy allowed the reduction of the weight by 25% for the lower control arm and 30% for upper control arm.
Problems of Producing Thin-Walled and Elastic Elements by Selective Laser Sintering
Authors: Kozior Tomasz
Published: November 2014

The article describes the technology of making thin-walled components and elastic by additive technology SLS using a polyamide powder PA 2200. The characteristics of the selected elements and the results of their strength tests are presented. The research focuses on the anisotropy of the materials in the various models. Printing processes were investigated on surfaces perpendicular and parallel to the axis of the model. Based on measurements of deformation, coefficients of elasticity, and the influence of selected parameters of the printing process, the accuracy of tested elements were determined. Comparing results of the research indicated that there is a significant influence of direction and printing process parameters on elastic properties. Research can be helpful in the future in the design process of elastic and thin-walled components such as springs and bellows.
Monitoring the FSW Processes Using a Multispectral Vision Method
Authors: Mężyk Jordan , Garbacz Piotr
Published: November 2014

The FSW method is a modern and still not very common method for joining materials by mixing them after plasticising with a special tool. The rotary motion of the tool and its pressure against the welded surface causes friction and, as an effect, local heating of the material that then causes plasticisation. Then the tool moves linearly along the trajectory of welding, while the stem causes the mixing of materials and tool’s shoulder concentrates and presses the material in the produced weld. An important feature of the process is that the material does not pass to the liquid phase and remain in the solid phase. This method allows the combination of non-welding and difficult to weld materials, including combining different materials (dissimilar). The FSW method is a new method and there are no tools to assess the quality of the process, especially on-line, that is in the making of the weld. Currently, the research methods used include point temperature measurement and measurement of forces on the tool performed during welding, and metallographic methods that are destructive can be used after the weld. This article presents the authors’ method for monitoring the Friction Stir Welding (FSW) processes with use of a multi-spectral vision method. The monitoring method uses the system built of two visual channels that work in different light bands; hence, the name of the method ismulti-spectral.The main component of the system is an infrared camera that is used for the observation of the temperature distribution on the surface of the welded materials. The second visual channel uses the line-scan visual band camera for recording the image of the surface of the weld. Such observation allows the detection of weld defects and non-compliances, which include excessive burrs, discontinuities, uneven edge of the weld, as well as the subsurface faults such as cavities and sub-surface discontinuities. In addition, the temperature of the process is monitored to prevent under-and over-heating, which may result in a weak joint or cracks in the material. The presented method is applied for monitoring the FSW process and presents a worldwide novelty.
Differential Ion Mobility Spectrometry in Application to the Analysis of Gases and Vapours
Authors: Maziejuk Mirosław , Lisowski Wiesław , Szyposzyńska Monika , Sikora Tomasz , Zalewska Anna
Published: November 2014

Ion mobility spectrometry (IMS) is a technique used for the detection of chemical warfare agents (CWA), drugs, toxic industrial compounds (TIC), and explosives, when rapid detection should be performed (from a few to several seconds) for trace amounts of these substances. An important development of IMS technology is differential ion mobility spectrometry (DMS). DMS is also known as Field Asymmetric Waveform Ion Mobility Spectrometry (FAIMS). Detection possibilities of apparatus using the DMS method are based on the occurrence of the different mobilities of ions (K) in the alternating electric field. This dependence is characterized by the alpha function (α).This presentation shows methods and examples of the identification of chosen substances. The results for the dependence of coefficient α are specific for different types of substances. This specificity is used to identify vapours and gases.
Innovative Optical System for the Inspection of Manufacturing Processes Using the Wavelet Approach
Authors: Marciniak Beata , Maszewski Mirosław , Zabłudowski Łukasz , Ledziński Damian
Published: November 2014

The paper presents a method of optical inspection of manufacturing processes in the visible band. The presented model of a test bench was based on a monochrome CCD camera that allows you to conduct research in the field of digital image analysis. The wavelet transform was proposed for the detection of objects and was compared with a Fast Fourier Transform (FFT). The article presents an analysis of the results of experiments for selected objects using the proposed method, allowing the evaluation of the correctness of classification. The paper also presents an analysis of the efficiency of the compared methods. In the article, the advantages of using the proposed method in the sample manufacturing process have been discussed.
The Concept of the System for Parameterization of Functionalized Membranes
Authors: Skowroński Jarosław , Bojarska Marta , Neska Mirosław
Published: November 2014

Microbial biofilm formation on membrane surface layer (biofouling) impedes filtration processes through increased material-and energy consumption and causes the risk of contamination by microorganisms and their metabolites. Due to the constantly growing resistance of microorganisms to the commonly used methods of prevention, it is necessary to develop functionalised materials and coatings of stable, non-specific, and effective antimicrobial properties. The integral step in the process of the development of such materials and coatings is universal and reliable testing under process conditions. The intensity of biological fouling is proportional to the microbial cell concentration in the system. Potentially present organisms are systematically varied and may include bacteria, fungi, and microscopic plants. The most convenient and universal method for microbial cell concentration assessment features the measurement of optical density of the liquid. Moreover, biofilm formation is dependent on the physiochemical factors, such as temperature, the chemical composition of feed liquid, membrane material, process flows, and pressures, etc. Additionally, process conditions may affect the activity of the functionalised material used for membrane formation. For this purpose, an integrated approach for multiparameteric assessment is needed, taking into account the measurements of the above listed parameters and allowing for comparisons. The proposed modular test stand includes a number of actuators and measurement sensors, which enable the following control functions: the control over the process fluid flow, the control over the emission on the test object of electromagnetic radiation in the required spectrum, and implementation of the optical density measurements of the fluid. The whole installation test is placed in one closed cubature of controlled thermal conditions. The control system allows the recording and archiving of process data, which are collected (on-line) by a PLC and transferred to a PC via Ethernet interface. Dedicated software application on the PC provides a preliminary analysis and allows remote monitoring via a web browser. Remote access to measurement data can also be used for the creation of a network of series of such test stands, in which different aspects of the studied phenomenon are simultaneously analysed and controlled as the modules of a network control system (NCS). The described system will allow the multiparameteric, universal and reliable assessment of antimicrobial properties of functionalised membranes under process conditions. The modular character of the proposed approach will be fully reconfigurable and adaptive for a wide range of membrane types. The results to be obtained will support the process of sustainable membrane development.