Analysis of the Antenna＇s Setup Errors at the Global Navigation Satellite System Measurements

Today, the GNSS （global navigation satellite system） is used for more complicate and accurate applications such as monitoring or stake out works. The truth lies in the fact that in the most of the times not enough attention is paid to the antenna＇s setup. Usually, gross errors are found in the antenna＇s centering, leveling and in the measurement of its height, which are significant. In this paper, a thoroughly analysis of the above mentioned errors is carried out. The influence of these errors in the calculation of the X, Y, Z Cartesian geocentric coordinates and the ~, 2, h ellipsoid geodetic coordinates of a point P on the earth＇s surface, is analyzed and is presented in several diagrams. Also a new convenient method for the accurate measurement of the antenna＇s height is presented and it is strongly proposed. The conclusions outline the magnitude of these errors and prove the significance of the antenna＇s proper setup at the accurate GNSS applications.     

Chimeric Stimuli-Responsive Liposomes as Nanocarriers for the Delivery of the Anti-Glioma Agent TRAM-34

Nanocarriers are delivery platforms of drugs, peptides, nucleic acids and other therapeutic molecules that are indicated for severe human diseases. Gliomas are the most frequent type of brain tumor, with glioblastoma being the most common and malignant type. The current state of glioma treatment requires innovative approaches that will lead to efficient and safe therapies. Advanced nanosystems and stimuli-responsive materials are available and well-studied technologies that may contribute to this effort. The present study deals with the development of functional chimeric nanocarriers composed of a phospholipid and a diblock copolymer, for the incorporation, delivery and pH-responsive release of the antiglioma agent TRAM-34 inside glioblastoma cells. Nanocarrier analysis included light scattering, protein incubation and electron microscopy, and fluorescence anisotropy and thermal analysis techniques were also applied. Biological assays were carried out in order to evaluate the nanocarrier nanotoxicity in vitro and in vivo, as well as to evaluate antiglioma activity. The nanosystems were able to successfully manifest functional properties under pH conditions, and their biocompatibility and cellular internalization were also evident. The chimeric nanoplatforms presented herein have shown promise for biomedical applications so far and should be further studied in terms of their ability to deliver TRAM-34 and other therapeutic molecules to glioblastoma cells.     

Goal-Oriented Requirements Engineering: A Unifying Framework

The study of contemporary requirements engineering (RE) methodologies indicates that modelling of organisational goals constitutes a central activity of the RE process. In particular, goals provide the rationale and drive the elaboration of the requirements that operationalise them. They also provide the criteria against which the completeness and correctness of the requirements specification is validated. In other words, requirements implement goals in the same way that programs implement design specifications. Despite the significance of goals in RE, research in the field is fragmented. No research has so far taken place in order to define the overall role that goals play in RE. This paper puts forward a unifying view of goal analysis in the context of RE. This allows the identification of similarities and differences between the different conceptions of goal used by different approaches and promotes the understanding of the overall role of goal analysis in RE. Based on this understanding the various approaches can be put together, thus leading to a stronger goal-driven RE framework that takes advantage of the contributions from the many streams of goal-oriented research.     

China’s emerging centrality in the contemporary international scientific collaboration network

In this paper we analyze the evolution of China’s growing importance in international scientific collaboration over the past 15 years. Using co-authored publications indexed in Clarivate Analytics’s Web of Science Core Collection we develop novel weighted and unweighted centrality measures to quantify China’s emerging role in the global scientific research network. We analyze the networks formed by international co-authorship in three 5-year periods: 2001–2005, 2006–2010, and 2011–2015. This analysis highlights China’s sharp increase in prominence in international scientific collaborations. The analysis of China’s co-authored, highly cited papers also illustrates China’s rising importance in scientific research and collaboration from a different perspective. The impact of multilaterally co-authored papers to the centrality measure is also analyzed both theoretically and empirically. The results show that multilateral collaboration is also a key factor that influences the centrality of a country beyond simply the scale of international co-authorship. We further contextualize our work in a discussion of international scientific collaboration as both a key driver of China’s economy and its emerging perception as a first-world innovator and intellectual power. Finally, we suggest directions for further research including more granular analysis by academic discipline and an alternative investigation based on the fractional counting method.     

Job Resources Buffer the Impact of Job Demands on Burnout.

This study tested and refined the job demands-resources model, demonstrating that several job resources play a role in buffering the impact of several job demands on burnout. A total of 1,012 employees of a large institute for higher education participated in the study. Four demanding aspects of the job (e.g., work overload, emotional demands) and 4 job resources (e.g., autonomy, performance feedback) were used to test the central hypothesis that the interaction between (high) demands and (low) resources produces the highest levels of burnout (exhaustion, cynicism, reduced professional efficacy). The hypothesis was rejected for (reduced) professional efficacy but confirmed for exhaustion and cynicism regarding 18 out of 32 possible 2-way interactions (i.e., combinations of specific job demands and resources). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cycle bases of graphs and sampled manifolds

Point samples of a surface in are the dominant output of a multitude of 3D scanning devices. The usefulness of these devices rests on being able to extract properties of the surface from the sample. We show that, under certain sampling conditions, the minimum cycle basis of a nearest neighbor graph of the sample encodes topological information about the surface and yields bases for the trivial and non-trivial loops of the surface. We validate our results by experiments.     

Dental Polymer Nanocomposites Light-Cured under Polyester Strip: Effect of Water or Ethanol/Water Solution on Surface Characteristics Studied by SEM and AFM

The purpose of this work is the study of surface characteristics of four dental light-cured dimethacrylate-based resin nanocomposites after immersion in water or an ethanol/water solution, using scanning electron microscopy and atomic force microscopy. Water and ethanol treatment affected the morphology and component distribution on the surface of samples. Scanning electron microscopy revealed changes on a large scale in the surface morphology of treated samples caused by immersion in water while the ethanol/water solution treatment influenced sample integrity too. It was proven that the use of atomic force microscopy in the phase-imaging mode is crucial in revealing subtle changes in component distribution on the polymer composite surface which are not accompanied by significant morphological changes.     

Phenols in Leaves and Bark of Fagus sylvatica as Determinants of Insect Occurrences

Beech forests play an important role in temperate and north Mediterranean ecosystems in Greece since they occupy infertile montane soils. In the last glacial maximum, Fagus sylvatica (beech) was confined to Southern Europe where it was dominant and in the last thousand years has expanded its range to dominate central Europe. We sampled four different beech forest types. We found 298 insect species associated with beech trees and dead beech wood. While F. sylvatica and Quercus (oak) are confamilial, there are great differences in richness of the associated entomofauna. Insect species that inhabit beech forests are less than one fifth of those species living in oak dominated forests despite the fact that beech is the most abundant central and north European tree. There is a distinct paucity of monophagous species on beech trees and most insect species are shared between co-occurring deciduous tree species and beech. This lack of species is attributed to the vegetation history and secondary plant chemistry. Bark and leaf biophenols from beech indicate that differences in plant secondary metabolites may be responsible for the differences in the richness of entomofauna in communities dominated by beech and other deciduous trees.     

Nickel and nickel-phosphorous matrix composite electrocoatings

Nickel and nickel-phosphorous matrix composite coatings reinforced by TiO₂, SiC and WC particles were produced under direct and pulse current conditions from an additive-free Watts' type bath. The influence of the variable electrolysis parameters (type of current, frequency of current pulses and current density) and the reinforcing particles properties (type, size and concentration in the bath) on the surface morphology and the structure of the deposits was examined. It is demonstrated that the embedding of ceramic particles modifies in various ways the nickel electrocrystallisation process. On the other hand, Ni-P amorphous matrix is not affected by the occlusion of the particles. Overall, the imposition of pulse current conditions leads to composite coatings with increased embedded percentage and more homogenous distribution of particles in the matrix than coatings produced under direct current regime.