bluuebunny/crossref_metadata_2025 huggingface dataset:
COMPARING SIMULATIONS OF AGN FEEDBACK
Authors: Richardson Mark L. A. , Scannapieco Evan , Devriendt Julien , Slyz Adrianne , Thacker Robert J. , Dubois Yohan , Wurster James , Silk Joseph
Published: July 2016

We perform adaptive mesh refinement (AMR) and smoothed particle hydrodynamics (SPH) cosmological zoom simulations of a region around a forming galaxy cluster, comparing the ability of the methods to handle successively more complex baryonic physics. In the simplest, non-radiative case, the two methods are in good agreement with each other, but the SPH simulations generate central cores with slightly lower entropies and virial shocks at slightly larger radii, consistent with what has been seen in previous studies. The inclusion of radiative cooling, star formation, and stellar feedback leads to much larger differences between the two methods. Most dramatically, at

rapid cooling in the AMR case moves the accretion shock to well within the virial radius, while this shock remains near the virial radius in the SPH case, due to excess heating, coupled with poorer capturing of the shock width. On the other hand, the addition of feedback from active galactic nuclei (AGNs) to the simulations results in much better agreement between the methods. For our AGN model, both simulations display halo gas entropies of 100 keV cm2, similar decrements in the star formation rate, and a drop in the halo baryon content of roughly 30%. This is consistent with the AGN growth being self-regulated, regardless of the numerical method. However, the simulations with AGN feedback continue to differ in aspects that are not self-regulated, such that in SPH a larger volume of gas is impacted by feedback, and the cluster still has a lower entropy central core.
Analysis of Marketing Strategy for Food Supplements and Over-The-Counter Medicines
Authors: Dzeparoski Marjan , Trajkovic-Jolevska Suzana
Published: July 2016

Marketing strategy is correlated with the regulations for the corresponding product category. Accordingly, there is a big difference in the marketing strategy of food supplements and over-the-counter medicines. In this paper are presented 2 different marketing strategies of a new small pharmaceutical company in two studies. The findings of studies analysis can be used for developing marketing strategies in the wider sense and other products, for other small to medium sized companies in other countries of interest with similar regulations and help them understand how to position and promote themselves and their products.
Coopération et gouvernance : Normalisation ou reconquête du fait associatif ?
Authors: Marival Céline , Petrella Francesca , Richez-Battesti Nadine
Published: July 2016

Dans une perspective néo-institutionnaliste, nous cherchons à mettre au jour l’impact des restructurations actuelles sur le paysage associatif, en particulier sur les formes de gouvernance, nouvelles ou renouvelées, adoptées par ces coopérations. Nous caractérisons les conséquences du mouvement de concentration des associations sur leur structure de gouvernance et sur leur dimension sociopolitique. Alors que la réduction des marges de manœuvre associatives est souvent mise en avant par les acteurs et travaux universitaires, nous montrons que paradoxalement, le processus de coopération peut contribuer à redynamiser et réaffirmer la dimension socio-politique des associations à travers laquelle les associations contribuent au changement institutionnel. Nous nous appuyons sur des études de cas menées en PACA et en Languedoc-Roussillon.
Critical Association Between Mental Health Disorders and Medical Status: Depression Intervention Use Indicates a Two-Fold Risk for Subsequent Medical Events in Older American Home Health Care Patients
Authors: Wang Jinjiao , Jia Haomiao , Shang Jingjing , Kearney Joan A.
Published: July 2016

The current study examined longitudinal associations between mental disorders and all-cause subsequent medical events in a 5% random sample of records in the 2010 national Outcome and Assessment Information Set. Records of older adults (
N
= 28,475) receiving home health care (HHC) services were examined with respect to mental disorders and medical events, including acute care hospitalization, emergency department admission, and 30-day rehospitalization. Predominant mental disorders were depression and anxiety identified by formal diagnoses, symptom clusters, and/or prescription of related mental health services. Depression intervention use was the strongest risk factor for all three types of medical events. However, 61.6% of patients receiving depression interventions did not screen positive at admission using the Patient Health Questionnaire-2. Moving forward, nurses must closely monitor high-risk older adults throughout the HHC stay using sensitive depression screening tools, as well as receive targeted training in geriatric psychiatry. [
Journal of Gerontological Nursing, 42
(10), 42–55.]
A Preliminary Study for Building an Arabic Corpus of Pair Questions-texts from the Web: AQA-WebCorp
Authors: Bakari Wided , Bellot Patrice , Neji Mahmoud
Published: July 2016

With the development of electronic media and the heterogeneity of Arabic data on the Web, the idea of building a clean corpus for certain applications of natural language processing, including machine translation, information retrieval, question answer, become more and more pressing. In this manuscript, we seek to create and develop our own corpus of pair’s questions-texts. This constitution then will provide a better base for our experimentation step. Thus, we try to model this constitution by a method for Arabic insofar as it recovers texts from the web that could prove to be answers to our factual questions. To do this, we had to develop a java script that can extract from a given query a list of html pages. Then clean these pages to the extent of having a data base of texts and a corpus of pair’s question-texts. In addition, we give preliminary results of our proposal method. Some investigations for the construction of Arabic corpus are also presented in this document.
Design of a Simple UV Double Beam Spectrophotometer Detector Based on a High Gain Trans Impedance Operational Amplifiers for RNA Measurement
Authors: Abdelbary Alakhib Ibrahim , Ahmed Abdelrahim Elobied
Published: July 2016

In this work a simple double beam spectrophotometer detector for the nucleic acid detection has been designed. The developed system contains photodiodes as a sensor, logarithamatic transimpedance amplifier circuit and filter circuit.The developed prototype design accuracy is validated by running a RNA sample and the result shows that our simplified developed setup detects the present of RNA in the sample.
Design Space Exploration Using Cycle Accurate Simulator
Authors: Shahid Arsalan , Khalid Bilal , Qadri Muhammad Yasir , Qadri Nadia N. , Ahmed Jameel
Published: July 2016

Multi-Processor System on Chip (MPSoC) architectures have become a mainstream technology for obtaining performance improvements in computing platforms. With the increase in the number of cores, the role of cache memory has become pivotal. An ideal memory configuration is always desired to be fast and large; but, in fact, striking to balance between the size and access time of the memory hierarchy is considered by processor architect. Design space exploration is used for performance analysis of systems and helps to find the optimal solution for obtaining the desired objectives. In this chapter, we explore two design space parameters, i.e., cache size and number of cores, for obtaining the desired energy consumption. Moreover, previously presented energy models for multilevel cache are evaluated by using cycle accurate full system simulator. Our results show that with the increase in cache sizes, the number of cycles required for application execution decreases, and by increasing number of cores, the throughput improve.
Methodology for FPGA Implementation of a Chaos-Based AWGN Generator
Authors: De Micco Luciana , Larrondo Hilda Angela
Published: July 2016

Additive White Gaussian Noise (AWGN) generators are a basic tool for the test and measurement of digital systems. One drawback for hardware implementation of the classically used algorithms is that they require the hardware implementation of complex operations (such as sinusoidal and logarithmic functions). In this chapter, a method for the design and hardware implementation of an AWGN generator based on chaotic maps is described. The advantage is that deterministic chaotic systems are described by simple nonlinear equations, and therefore, they are straightforward to implement in hardware. To ensure that the generated sequence has the desired Probability Density Function (PDF), the chaotic map, which is the heart of the system, is synthesized using an approach based on the theory of positive matrices method. The hardware implementation was developed using an Altera Cyclone III FPGA with the 3C120 Development Board.
Reconfigurable Virtual Instrumentation Based on FPGA for Science and High-Education
Authors: Crespo Maria Liz , Cicuttin Andres , Gazzano Julio Daniel Dondo , Rincon Calle Fernando
Published: July 2016

In this chapter we will show how modern FPGA offers the possibility of implementing Reconfigurable Virtual Instrumentation, a new kind of electronic instrumentation which generates interesting opportunities for regular users but that also poses several technical challenges for advanced users and instrument developers. We will analyze some of the main problems and we will give some ideas and possible strategies to deal with them. In order to put the subject in the right context we will review some general concepts regarding instrumentation in general and we later proceed with some more specific concepts and definitions. The chapter also describes two hardware/software platforms for science and high-education developed at the International Centre for Theoretical Physics (ICTP) where the concept of RVI proposed in this chapter was applied. Although we mainly adopt a scientist's prospective to define and analyze instrumentation, most of the conclusions drawn along this chapter can be easily generalized for a wide range of applications in commercial or industrial sectors.
Hardware Implementation of a Genetic Algorithm for Motion Path Planning
Authors: Mahmoud Imbaby I. , Salama May , El Hamid Asmaa Abd El Tawab Abd
Published: July 2016

The aim of this chapter is to investigate the hardware (H/W) implementation of Genetic Algorithm (GA) based motion path planning of robot. The potential benefit of using H/W implementation of genetic algorithm is that it allows the use of huge parallelism which is suited to random number generation, crossover, mutation and fitness evaluation. The operation of selection and reproduction are basically problem independent and involve basic string manipulation tasks. The fitness evaluation task, which is problem dependent, however proves a major difficulty in H/W implementation. Another difficulty comes from that designs can only be used for the individual problem their fitness function represents. Therefore, in this work the genetic operators are implemented in H/W, while the fitness evaluation module is implemented in software (S/W). This allows a mixed hardware/software approach to address both generality and acceleration. Moreover, a simple H/W implementation for fitness evaluation of robot motion path planning problem is discussed.
Application of Three Meta-Heuristic Algorithms for Maximizing the Net Present Value of a Resource-Constrained Project Scheduling Problem with Respect to Delay Penalties
Authors: Rabbani Masoud , Arjmand Azadeh , Saffar Mohammad Mahdi , Jalali Moeen Sammak
Published: July 2016

The Resource Constrained Project Scheduling Problem (RCPSP) is been studied under different kinds of constraints and limitations. In this paper, we are going to consider the discounted cash flows for project activities, and delay penalties which occur when the project make span exceeds its deadline as the objective function of the RCPSP. To solve the model, we will take advantage of three different meta-heuristic algorithms - Genetic Algorithm (GA), Imperialist Competitive Algorithm (ICA), and Shuffled Frog Leaping Algorithm (SFLA) - to achieve the optimal solution of the problem. The evaluation of the algorithms performance reveals that, in comparison with ICA and SFLA, GA performs better, especially in large-scale problems.
The Consequence of Customer Verbal Aggression
Authors: Yeh Ching-Wen
Published: July 2016

This study integrated research on stimulus–organism–response and COR theory to examine whether customer verbal aggression lead to employee service sabotage through emotional dissonance and whether person-organization fit moderate the relationship between customer verbal aggression and emotional dissonance. To achieve this goal, this study surveyed flight attendants employed by six airlines in Taiwan. Out of 1000 questionnaires distributed, 504 valid questionnaires were returned, yielding a valid response rate of 50.4 percent. The research results demonstrate that emotional dissonance partially mediates the relationship between the customer verbal aggression and service sabotage. Additionally, person-organization fit negatively moderates the relationship between customer verbal aggression and emotional dissonance. Based on these results, suggestions regarding service management are presented as a reference for airlines.
A Study on Customer Loyalty as a Determinant for Harnessing Power Brands
Authors: Panda Rajshree , Kapoor Deepa
Published: July 2016

Power brand is a new topic in the field of branding that has started to attract researcher's attentions yet; it is still mostly discussed in the non-academic field. Consumer loyalty has always been the central topic in marketing. These two concepts are the focuses of this research. The main subject of this research is to explore the drivers of power brand its effect and influence on customer loyalty. Even though there are few articles related to power brand, so far no quantitative research has been conducted. This study aims at identifying the factors which contribute strong brand positioning which impact customer loyalty and drivers of power brand. This study starts with examining the relevant literatures of branding, consumer behavior. Then, the hypotheses and research model are proposed based on theories. The study suggests respondents consider Power brands setting a differentiating approach to beat the competition and respondents normally have a positive past experience with the brand associated.
The Effects of Risk Preferences on Consumer Purchasing Counterfeit Goods Online
Authors: Chen Yi-Fen , Kung Hing-Yu , Tsai Chia-Wen
Published: July 2016

Nowadays ways of purchase are changing with the maturity and rapid development of e-commerce. There are two studies in this research paper. In study 1, one online experiment was conducted with 263 subjects, it aims to figure out the relationship between consumers' risk preference and risk in online purchase environment. In study 2, the other online experiment was conducted involving 263 subjects. It aims to explore consumer purchase intention in counterfeit goods by experimental design including those three variables. It is found risk preferences on consumers and risks in purchase environment must be considered in the same time, because the interaction between risk preference of consumers and risks in online purchase environment for impact on purchase intention will be significant. The product itself like product with logo or not is the biggest factor to attract consumers to purchase. Risk will not affect consumer purchase intention while there are no other variables; but it would affect consumers purchase intention while consumers consider brand logo at same time.
Timing Structure Mechanism of Wireless Sensor Network MAC layer for Monitoring Applications
Authors: El-Basioni Basma M. Mohammad , Moustafa Abdellatif I. , El-Kader Sherine M. Abd , Konber Hussein A.
Published: July 2016

This paper aims at designing a Timing Structure Mechanism (TSM) for Wireless Sensor Network (WSN) MAC, with specifying its respective logical topology, especially suitable to the monitoring applications, differentiated and characterized from the existing time bounding strategies, paving for a good performance channel access mechanism. The work proposed in this paper is based on classifying the monitoring applications so as to designing efficient setup and benefiting from the node's capabilities in dividing the network into sub-networks. By evaluating TSM against a cluster-tree IEEE802.15.4 in the two cases of one channel and multi-channel clusters, the simulation results showed that with varying the area, the TSM performs better than the two cases of IEEE802.15.4 in terms of lifetime, end-to-end delay, loss percentage by on average 103.44% and 61.84%, 96.59% and 95.37%, and 88.59% and 87.52%, respectively. Also, in case of increasing the node density, TSM is better in terms of the same parameters by on average 446.58% and 356.05%, 98.04% and 95.62%, and 77.62% and 75.2%, respectively.
Towards an Optimal Generation of Zones Graph Relating Timed Bisimulation Relation and Distribution
Authors: Riadh Matmat , Ilham Kitouni , Eddine Saidouni Djamel
Published: July 2016

The timed automata are extensively used in different fields of formal validation in particular the model checking one. In this paper the authors are interested by a class of TA called durational actions timed automata (daTA) and the zones graph which represents an exact finite state abstraction based on what called Zones. The authors present a novel approach to construct a zone graph, based on the maximality semantics called maximality-based zone graph (MZG) by a local construction approach and they define timed maximality bisimulation relation for real-time model based on the maximality semantics. The authors propose a new method for distributed state space generation of maximality-based zone graph based on DHT structure. They also describe an implementation of this construction (DTaMaZG tool). The experiments given at the end of this article has shown good results especially when comparing with other works that have already proceed in the distributed generation of MLTS (Maximality based Labeled Transition Systems).
Knowledge-Based Systems for Data Modelling
Authors: Šuman Sabrina , Jakupović Alen , Kuljanac Francesca Gržinić
Published: July 2016

Data modelling is a complex process that depends on the knowledge and experience of the designers who carry it out. The quality of created models has a significant impact on the quality of successive phases of information systems development. This paper, in short, reviews the data modelling process, the entity-relationship method (ERM) and actors in the data modelling process. Further, in more detail it presents systems, methods, and tools for the data modelling process and identifies problems that occur during the development phase of an information system. These problems also represent the authors' motivation for conducting research that aims to develop a knowledge-based system (KBS) in order to support the data modelling process by applying formal language theory (particularly translation) during the process of conceptual modelling. The paper describes the main identified characteristics of the authors' new KB system that are derived from the analysis of existing systems, methods, and tools for the data modelling process. This represents the focus of the research.
Putting Implementation into Enterprise Architecture Research
Authors: Dale Mark
Published: July 2016

Enterprise architecture (EA) has provided organizations with powerful frameworks with which to plan, manage, model and coordinate the alignment of organizational IS/ IT portfolios with organizational strategy. However, for the benefits of EA to be realized, it needs to also contribute to the process of implementing the specified systems and platforms. Whilst implementation was seen by early authors as an integral aspect of the EA process, it has since generally been ignored by authors, or investigated through an ontological lens of discreet technical architecture activities that does not account for the social context of an EA implementation (EAI). Drawing on an actual case study of an EAI in a large Australian financial services organization, I examine the importance of the EAI process to the delivery of the systems and platforms specified in the EA plans and highlight an alternative perspective that has the potential to sensitize scholars and practitioners appreciate to the social context of an EAI.
An Investigation into using SAP-PS as a Multidimensional Project Control System (MPCS)
Authors: Machen Brett , Hosseini M. Reza , Wood Anthony , Bakhshi Javad
Published: July 2016

This paper investigates the effectiveness of using a corporate enterprise resource planning (ERP) system as a multi-dimensional project control system (MPCS) to monitor and control the work performed on projects, meet the needs and expectations of the project managers and support the requirements of other key stakeholders. A qualitative approach i.e. case study interviews and literature review accompanied by a quantitative computer system validation test approach was deployed. The results from this study suggest that the corporate ERP system is effective at monitoring and controlling the project stakeholder success criteria within a fully integrated environment. The system does however need to be setup and configured for the purpose of MPCS. This study contributes to the field by providing empirical evidence that corporate ERP systems are likely one of the only systems truly capable of solving the age old problem of how to expand the traditional singular dimensional approaches commonly used in project control, thus multiple control dimensions are integrated with each other and other business systems to form a multi-dimensional project control system.
The Optimized Dynamic Behavior of Short Embankment Based on Frequency Performance
Authors: Gordan Behrouz , Adnan Azlan
Published: July 2016

Due to the performance of embankment under the earthquake, relative displacement at both edges of the crest is very important for body cracks. It can be computed by dynamic analysis. In this way, response spectrum analysis and Rayleigh damping coefficient are dependent factors to dominant frequency. Based on the new technology using advanced programs to compute frequency, free vibration analysis as the basic technique and considering of different vibration modes is accessible. This research tried to evaluate the distribution of dominant frequencies for short embankment (H=30 meter) using Finite-Element Method (ANSYS 13). To evaluate of the frequency, elasticity modulus ratio and foundation depth ratio were the main objectives. Both were defined by the ratio between the embankment and foundation. As a result, maximum and minimum vertical displacements were located on both slopes, and maximum horizontal displacement was exposed at the crest. The dominant frequency increased as the modulus ratio decreased. In addition, dominant frequency decreased as the depth ratio increased. The impact of the modulus ratio to enhance frequency was greater than the depth ratio. In terms of contributing engineering, the amplitude of the dominant frequency (Hz) was finally optimized for modulus ratios (0.25-1.00) and depth ratios (0.1-1.00). For critical situation, modulus ratio was more than three, and the depth ratio was half of the unit. More research about medium embankment is recommended.
Pseudo-Dynamic Bearing Capacity of Shallow Strip Footing Resting on c-Φ Soil Considering Composite Failure Surface
Authors: Saha Arijit , Ghosh Sima
Published: July 2016

The evaluation of bearing capacity of shallow strip footing under seismic loading condition is an important phenomenon. This paper presents a pseudo-dynamic approach to evaluate the seismic bearing capacity of shallow strip footing resting on c-F soil using limit equilibrium method considering the composite failure mechanism. A single seismic bearing capacity coefficient (N?e) presents here for the simultaneous resistance of unit weight, surcharge and cohesion, which is more practical to simulate the failure mechanism. The effect of soil friction angle(F), soil cohesion(c), shear wave and primary wave velocity(Vs, Vp) and horizontal and vertical seismic accelerations(kh, kv) are taken into account to evaluate the seismic bearing capacity of foundation. The results obtained from the present analysis are presented in both tabular and graphical non-dimensional form. Results are thoroughly compared with the existing values in the literature and the significance of the present methodology for designing the shallow strip footing is discussed.
Identifying Dissatisfied 4G Customers from Network Indicators
Authors: Huet Alexis , Ouyang Ye , Mantian (Mandy) Hu  , Dai Xinling
Published: July 2016

Feedback data directly collected from users are a great source of information for telecom operators. They are usually retrieved as complaints and survey data. For the mobile telecoms sector, one purpose is to manage those data to identify network problems leading to customer dissatisfaction. In this paper, a quantitative methodology is used to predict dissatisfied users. It focuses on extraction and selection of predictive features, followed by a classification model. Two sets of data are used for experiments: one is related to complaints, the other to survey data. Since the methodology is similar for those two sets, prediction efficiency and influence of features are compared. Specific influence of user loyalty in survey data is highlighted. Thus, the methodology presented in this article provides a reference for the mobile operators to improve procedures for collecting feedback answers.
A Novel Secret Key Generation Method in OFDM System for Physical Layer Security
Authors: Dong Wang , Aiqun Hu , Linning Peng
Published: July 2016

In this paper, a novel physical layer key generation method for extracting secret key from mutual channel information in orthogonal frequency division multiplexing (OFDM) systems has been proposed. Firstly, a well-designed data extraction process has been introduced to reduce the redundancy and inconsistency of channel state information (CSI). After that, a new quantization method using gray code is proposed. Furthermore, an associated method is designed to reduce key error rate (KER). With these improvements, higher key generation rate (KGR) can be obtained compared to existing methods. Finally, available secret keys have been generated after information reconciliation and privacy amplification. The proposed method has been analyzed and verified in long term evolution advanced (LTE-A) systems and the generated secret keys have passed randomness test.
Alignment Evolution under Ontology Change
Authors: Zahaf Ahmed , Malki Mimoun
Published: July 2016

The alignment of ontologies is the backbone of semantic interoperability. It facilitates the import of data from an ontology to another, translating queries between them or merging ontologies in a global one. However, these services cannot be guaranteed throughout the life cycle of the ontology. The problem is that the evolution of mapped ontologies may be affected and make obsolete the relationship of the mapping. Inspired by belief revision theory, the authors identify and formalize the constraints and requirements of the alignment evolution problem. Then they give an orchestration of designed operations to resolve the problem. The satisfaction of these constraints and requirements is discussed for each operation showing its strengths and weaknesses. Finally, the authors conduct an experimental process with the objective to show the limits of alignment evolution methods and ontology matching tools when dealing with alignment evolution problem highlighting the emergency to invest in dedicated methods.
Internationalization of Technology Education in National Research Tomsk Polytechnic University
Authors: Soon Lisa , Kashkan Galina V. , Marukhina Olga V. , Axyonov Sergey V.
Published: July 2016

This research investigates the internationalization of Master of Information Technology (MIT) education in National Research Tomsk Polytechnic University (TPU). Through a conducted case study about a course (also known as a subject or a unit) specially developed and delivered by a foreign researcher-teacher for the internationalized MIT program, it investigated how TPU approached internationalization of MIT education, why the approach was adopted and how TPU overcame the challenges in internationalizing their MIT programs (offered in two languages) and curricula. The research adopted a qualitative case study research method, which involved the data collection techniques such as survey, observation and documentations. Ten MIT program students were involved in the course delivery. The research team observed how the MIT program worked, how the students learnt from the specially provided course by a foreign researcher-teacher in the MIT program, the challenges and difficulties in the delivery of course learning, and how they were overcome. The results indicated that the students were highly satisfied and greatly benefited from the specially developed course in their internationalized MIT program.
Importance of agronomic traits in the individual selection process in sugarcane determined using the logistic regression
Authors: Brasileiro Bruno Portela , Peternelli Luiz Alexandre , Silveira Luís Cláudio Inácio , Barbosa Márcio Henrique Pereira
Published: July 2016

The aim of this study was to evaluate the importance of agronomic traits during the selection of sugarcane (Saccharum spp.), as well as to evaluate the potential for using logistic regression and decision trees to identify the best genotypes. A total of 7,719 seedlings of 128 half-sib families were evaluated during the first test phase (T1), and 659 clones were selected for the second (T2). Logistic regression was applied to both populations. The number of stalks, bud prominence and length of the internode were the most important selection traits in the T1 population. The plant vigor, stalk diameter and stalk height were the most important selection traits in the T2 population. There were 174 individuals selected when using the mass selection method in T1 and 113 individuals in T2, whereas a logistic regression selected 153 individuals in T1 and 79 in T2. The apparent error rates of the logistic models fitted to the selections in T1 and T2 were 0.8 and 5.10%, respectively. By using a decision tree, 67 clones were selected among the most productive ones in phase T2. Therefore, the formulation of decision trees is highly applicable to identifying potential clones during the initial phases of breeding programs.
Phosphorus as a mitigator of the effects of water stress on the growth and photosynthetic capacity of tropical C4 grasses
Authors: Kuwahara Frank Akiyoshi , Souza Gustavo Maia , Guidorizi Kezia Aparecida , Costa Ciniro , Meirelles Paulo Roberto de Lima
Published: July 2016

Water deficiency during the dry seasons influences the relationship between water and gas exchange in tropical grasses, reducing their productive potential. In addition, the phosphorus (P) deficiency Brazilian soils adds to the set of factors limiting crop production. In this context, the objective of this study was to evaluate the responses of different tropical forage species to phosphorus supplementation as mitigating the damage caused by water stress. Seeds of Urochloa brizantha cv. MG-4, Urochloa decumbens cv. Basilisk, Panicum maximum cv. Áries, Panicum maximum cv. Tanzânia and Paspalum atratum cv. Pojuca were germinated in pots containing 10 liters of red-yellow Acrisol type soil. Experiments were conducted by combining levels of phosphorus, 8,0 and 100,0 mg of P dm-3, with two irrigation regimes, 100 and 40% replacement of transpired water. The biometric parameters, photosynthetic capacity, leaf water potential and soil chemical characteristics were evaluated, and the data was submitted to analysis of variance (ANOVA, p < 0.05), and subsequently the means were compared using a Tukey test (p < 0.05). The results showed for tropical grasses grown under water stress, there is a clear mitigating effect of phosphorus supplementation, especially on the maintenance of biomass growth.
Mo-B-C and Ta-B-C Nanostructured Layers with Promising Fracture Toughness
Authors: Buršík Jiří , Kuběna Ivo , Buršíková Vilma , Souček Pavel , Zábranský Lukáš , Vašina Petr
Published: July 2016

X-B-C (X=Mo, Ta) layers prepared by magnetron sputtering were tested. Mechanical properties were characterized by means of nanoindentation experiments in both the static and the dynamic loading regime. The results were correlated with observations of the microstructure under indentation prints by means of scanning and transmission electron microscopy on cross sections prepared using a focussed ion beam. An excellent fracture resistance of prepared nanostructured coatings was found.
Effect of Neighboring Phase Properties on Measured Indentation Data
Authors: Kocmanová Lenka , Haušild Petr , Materna Aleš , Matějíček Jiří
Published: July 2016

The paper focuses on the variation of mechanical properties near the interface of two materials. The aim is to determine the properties of the individual phases and the size of the region influenced by the adjacent material. Nanoindentation measurements were performed in the vicinity of a sharp interface between tungsten and steel, which was a plane located parallel to the loading force direction. The probability of indentation in the affected area as a function of depth of penetration and distance from the interface was fitted by a proper statistical distribution function. The intrinsic properties of the individual phases can subsequently be extracted from the experimental indentation data.
Manufacturing and Evaluation of Porous PLA Nano/Micro Fibres
Authors: Macajová Eva
Published: July 2016

This study is mainly focused on the study of pore size and shape, fibre diameter and also on the optimization of polymer solution composition and electrospinning parameters with respect to the final structure and morphology of PLA nano/microfibrous layers. The nano/microfibres were produced by electrospinning from the needle. Except the spinning process parameters, the morphology of nanofibrous layers can be also affected by the composition of the polymer solution and by the used solvents. Variations in technological process allows us to design the shape and form of nanofibrous structures upon request. The morphology of nano/microfibres was observed by scanning electron microscopy (SEM). Following image analysis and calculation enables the assessment of porosity contribution to the increase in micro/nanofibre surface area.
Parametric Study of Concentrated Contact of Rigid Indenter with Elastic-Plastic Material
Authors: Zíta Dušan , Menčík Jaroslav
Published: July 2016

This paper shows the results of finite element modelling of contact problems between perfectly rigid body with rough surface and an indenter from elastic-plastic material. In the first phase, spherical indenter from elastic – plastic material is considered, which is pressed into a body with a rough surface. Results show the influence of the amplitude and distances of various undulations at the rough surface to response surface.
Micromechanical Characteristics of Hardly Deformable Mg Alloys
Authors: Gupta Saumya , Koudelková Veronika , Hrbek Vladimír , Němeček Jiří
Published: July 2016

Mechanical characterization of individual microstructural phases of hardly deformable magnesium alloys is of crucial importance for the development of multi-scale material models. The magnesium alloys are used for preparation of fine tubes with diameter of a few millimeters and tens of millimeters wall thickness. It is hard to control an ordinary drawing process for the preparation of such tubes. However, the tubes can be prepared with a laser dieless drawing process that is, in contrary to conventional drawing, able to draw low formability materials and it is able to produce variable cross-sections of the tube or a wire with high precision. The magnesium alloy tubes are used in various fields as micro-electro-mechanical systems, medicine, electrical, biological and chemical fields. In this paper, preliminary microstructural studies and local mechanical characterization of pure Mg, MgCa0.8 and AZ31 magnesium alloys used for tube extrusion, is provided. The material microstructure is studied by means of scanning electron, atomic force microscopes and nanoindentation. Elastic properties and volume fractions of mechanically distinct phases that are not accessible by standard testing methods are provided in the paper.
Wear Behavior of Stoichiometric and Nonstoichiometric Zirconia
Authors: Balko Jan , Tatarková Monika , Tatarko Peter
Published: July 2016

Zirconium oxide samples were sintered at two different temperatures (1250°C and 1450°C) using SPS method with maximum holding time 10 min. to obtain nonstoichiometric composition. Some of the samples were subsequently annealed for 6 hours at 1100°C to obtain stoichiometric composition. Wear rate and friction coefficient were obtained from tribological tests carried out on the UMT3 equipment (Bruker) using two different static partners (zirconia and alumina ball). Main aim of this work is to study the influence of composition and sintering temperature on the wear behavior, friction coefficient and basic mechanical properties.
Influence of Coating Process Parameters on the Mechanical and Tribological Properties of Thin Films
Authors: Bakalova Totka , Petkov Nikolay , Blažek Tomáš , Kejzlar Pavel , Louda Petr , Voleský Lukáš
Published: July 2016

Titanium carbonitride (TiCN) thin films with differing C content were deposited by cathodic arc evaporation of pure Ti in a gas composite environment of N2 and C2H2. Scanning electron microscopy (SEM), scratch test, mechanical profilometer and “ball-on-disc” tribometer methods were used to characterize the surface, the coefficient of friction (CoF) of the TiCN thin films and the evaluated wear. An increase of the C2H2 fraction in the gas environment leads to a continuous increase in the deposition rate of the TiCN thin films, as well as an increase in the adhesion of the films to the substrate and the values of the CoF. Tribological test results (when tested against Si3N4 balls) show an increase in the friction coefficient of the TiCN from 0.08 to 0.32, with increasing carbon concentration in the film. The CoF decreases rapidly to 0.06 at a C content of 20.6 at.%, N 38.4 at.% and Ti 41.0 at.%.
The Impact of the Deposition Parameters on the Mechanical Properties of Thin Carbon Layers
Authors: Voleský Lukáš , Bakalova Totka , Borůvková Karolína , Louda Petr
Published: July 2016

The article describes the effect of the pressure in the chamber during the deposition of thin layers on the basic mechanical properties of thin layers based on carbon. Monitoring parameters are mainly nanohardness, coefficient of friction and adhesion between the layer and substrate. This parameters are observed using nanohardness tester and scratch tester. All observed layers had the same thickens of layers. Carbon layers generally have poor adhesion to the substrate. To improve the adhesion, is used the interlayer of titanium which is between the substrate and carbon layer. Carbon layers are mostly used for their very good sliding properties especially in cases where can not be used process fluids or where is necessary to reduce the friction between the two materials. The carbon layer can also be used in medicine (for their biocompatibility), for machine tools (for their hardness and abrasion resistance) or as barriers layers (for their high chemical resistance).
A Novel Method for Preparing Calcium Carbonate Particles: Thermal Decomposition from Calcium Hydrogen Carbonate Solution
Authors: Zeng Hui Yan , Yan Zi Ling , Jiao Meng Ran , Xu Dong Dong , Jiang Jiu Xin
Published: July 2016

An entirely novel preparation method of calcium carbonate (CaCO3) from calcium hydrogen carbonate (Ca (HCO3)2) solution was presented and named as thermal decomposition. The variation of the polymorphs and morphologies of CaCO3 particles with reaction temperature was investigated. XRD result indicates that high temperature favors the formation of calcite. Cubic or rhombohedra calcite crystals, lamellar and spherical vaterite crystals and rod– and needle–like aragonite crystals are found in powder synthesized at different temperatures. The reaction process was also discussed in the present work.
Preparation and Characterization of Ultra-Fine ZrB2 Powders from Inorganic-Organic Hybrid Precursors via Carbothermal Reduction
Authors: Wang Bai Na , Duan Yun Biao , Hu Jin , Zhu Xiao Qin , Wang Kai Jun , Zhang Wei Jun
Published: July 2016

In the present study, we report on the synthesis and carbothermal reduction of ultra-fine zirconium diboride powders by using inorganic-organic hybrid precursors of Zirconium (IV) nitrate pentahydrate, boric acid and citric acid as sources of zirconia, boron oxide and carbon, resoectively. The effect of molar ratio of reactants and reaction temperatures on the as-synthesized precursors were investigated. The thermodynamic change in the ZrO2-B2O3-C system was mainly studied by thermogravimetric and differential scanning calorimetry. The phase compositions and crystalline state of the products after heat treatment was determined by X-ray diffraction and the crystallite size and morphology of the synthesized powders were characterized by scanning electron microscopy. It was found that the as-synthesized precursor with B/Zr molar ratio of 3.5 can transform into zirconium diboride and zirconium carbide by heating in an argon atmosphere with temperatures as low as 1400°C and the synthesized powders exhibited near-spherical morphology with a samll average crystallite size of about 200nm and dispersed relatively uniformly. Moreover, with the reaction temperature increased, the purity of the zirconium diboride powders are higher. The mixture was finally transformed into pure zirconium diboride at 1600°C. However, the grain sizes increased significantly and tended to be aggregated with the reaction temperature increased to 1600°C. The synthesized ZrB2 powders showed a porous structure and the grain sizes on the exterior is larger than the interior because of the higher heat treatment temperature. The finally single ultra-fine ZrB2 grain sizes were distributed from 190nm to 690nm in two-dimensions and have a larger specific surface area of 88.14m2/g.
Preparation and Properties of Lightweight, High-Strength Insulation Materials Using Fly Ash Floating Beads
Authors: Dai Ya Peng , Gu Xing Yong , Dong Wei Xia , Luo Ting
Published: July 2016

In our paper, to save energy conservation and environmental protection, and in view of waste fly ash floating bead with excellent properties such as light and refractory, lightweight insulation materials was prepared using fly ash floating beads as the main materials. Firstly, two different fly ash floating bead contents on the properties of the light and refractory material were investigated. Then, on the basis of the optimum fly ash floating bead content, effects of various different particle sizes and firing temperature on the bulk density, compressive strength and the heat conduction coefficients of the samples were studied. The microstructure of the light-weight refractory materials was characterized by XRD and SEM. The heat conduction coefficient (λ') of the samples were also measured by the self-made test instrument. The experimental results showed that the properties of the as-prepared sample using 80% fly ash floating beads was superior to that of 95 % fly ash floating beads. The optimal volume density of 0.60-1.04 g/cm3, compressive strength of 10.6-39.5 MPa and the heat conduction coefficient of 0.183-0.25 °C·g/ min·cm2 were achieved in the presence of 80% fly ash floating beads with 120-160 particle size at 1200°C-1300°C, which has the potential application in lightweight insulation materials.
Effects of Sintering Temperature and Excess Zr on Mechanical Properties of Reactive Hot-Pressed ZrB2-ZrCx-Zr Cermets
Authors: Guo S.Q.
Published: July 2016

In this study, a series of ZrB2-ZrCx-Zr cermets were prepared by reactive hot-pressing of Zr + B4C powder mixtures at different temperatures between 1400°C and 1900°C. The microstructure of the resulting cermets was characterized by field emission scanning electron microscopy. The strength and fracture toughness of the cermets were measured by four-point bending test at room temperature. The results showed that the strength and fracture toughness dependend on the amount of excess Zr and sintering temperature as well. In addition, the crack propagation behavior of the cermets was examined under indent cracking. The cracks induced by indenter directly propagated in the samples with less than 16 vol% Zr. For comparison, the multiple cracking behavior was observed for the samples with equal to or greater than 16% Zr. Furthermore, the effects of compositions and sintering temperatures on the microstructure and the mechanical properties of the cermets were discussed.
Immobilization of Laccase in Glycidoxypropyl-Functionalized Magnetic Mesoporous SiO2/Fe3O4 Hollow Microspheres
Authors: Wang Peng Yan , Li Qun Yan , Zhou Yun Lu , Wei Qi , Nie Zuo Ren
Published: July 2016

Glycidoxypropyl-functionalized magnetic mesoporous SiO2/Fe3O4 hollow microspheres (FMMS) with various amounts of terminally bonded groups in the pore channels were synthesized by the co-condensation of tetraethoxysilane (TEOS) and 3-glycidoxypropyltrimethoxylsilane (GPTMS) in the presence of cetyltrimethylammonium bromide (CTAB) and 1,3,5-triisoporpylbenzene (TMB), and utilized as supports for laccase immobilization. It is revealed that glycidoxypropyl groups have been successfully covalently attached to the pore wall of magnetic mesoporous SiO2/Fe3O4 hollow microspheres (MMS). The magnetic mesoporous SiO2/Fe3O4 microspheres (sample10%FMMS) have a saturation magnetization of 13.6 emu·g-1 and a low coercivity (50 Oe). The functional materials preserve a mesoscopic ordering at a concentration of GPTMS as high as 15%. The BET surface area and pore volume of the functionalized materials decrease with increasing amount of GPTMS, but a desirable pore structure remains when the GPTMS amount increases to 10%. The 10%FMMS material exhibits higher laccase immobilization and stability than pure MMS because of the covalent interaction between the amino groups of laccase and the epoxy groups of the functional MMS.
Redundant SAR ADC Algorithm Based on Fibonacci Sequence
Authors: Kobayashi Yutaro , Kobayashi Haruo
Published: July 2016

This paper describes a redundant Successive Approximation Register Analog-to-Digital Converter (SAR ADC) design method which enables high-reliability and high-speed AD conversion by using digital error correction. Especially we introduce to apply Fibonacci sequence and its property called Golden ratio to SAR ADC design to improve conventional redundant search algorithms. We also present some derived equations and many beautiful properties for well-balanced redundancy design for SAR ADC
Effect of Embedded TiO2 in Carbon Nanofiber Support on Pd Catalyst Activity for Formic Acid Oxidation
Authors: Aoyama Tomohiro , Nishio Yuki , Ishitobi Hirokazu , Nakagawa Nobuyoshi
Published: July 2016

Pd supported on TiO2-embedded carbon nanofibers (Pd/TECNF) were prepared as the anode catalyst for direct formic acid fuel cells (DFAFCs) using an electrospinning technique. The effect of the TiO2 content on the catalytic activity of Pd was investigated based on the electrochemical measurements of cyclic voltammetry (CV), chronoamperometry (CA), and also characterization by XRD, EDX, FE-SEM and CO stripping. The activity was significantly increased by an increase in the TiO2 content up to Ti/C=0.44 and then decreased. The maximized activity was improved eight fold by the TiO2 addition. The increased activity was attributed to the increased electrochemically active surface area due to the modified surface of the nanofibers.