3,077 research outputs found
Relationships Between Number of Verbal Associations to Value Words and Subjective Ratings of Values
This study attempts to demonstrate whether or not there is a relationship between Ss\u27 rankings of statements descriptive of Spranger\u27s values and the number of verbal associations made by the same Ss to nouns referring to these values. Noble (2) has demonstrated that one may define the meaningfulness of a stimulus word in terms of the number of associations to this word written by Ss within a prescribed time. Bousfield and Samborski (1) using the written association method of Noble attempted to test the hypothesis that for individuals the relative strength of personal values should correlate positively with the extent of meaningfulness of words related to these values. To test this hypothesis they correlated two measures of the same values derived from the same group of Ss. These were (a) strengths of Spranger\u27s values based on the Study of Values Scale of Allport, Vernon and Lindzey and (b) meaningfulness of words related to the Spranger values obtained by Noble\u27s (2) method. Two of the six values investigated, religious and theoretical, showed significant correlations
Thermodynamic modeling and validation of the temperature influence in ternary phase polymer systems
The effect of the temperature, as a process variable in the fabrication of polymeric membranes by the non-solvent induced phase separation (NIPS) technique, has been scarcely studied. In the present work, we studied the influence of temperature, working at 293, 313 and 333 K, on the experimental binodal curves of four ternary systems composed of PVDF and PES as the polymers, DMAc and NMP as the solvents and water as the non-solvent. The increase of the temperature caused an increase on the solubility gap of the ternary system, as expected. The shift of the binodal curve with the temperature was more evident in PVDF systems than in PES systems indicating the influence of the rubbery or glassy state of the polymer on the thermodynamics of phase separation. As a novelty, the present work has introduced the temperature influence on the Flory–Huggins model to fit the experimental cloud points. Binary interaction parameters were calculated as a function of the temperature: (i) non-solvent/solvent (g12) expressions with UNIFAC-Dortmund methodology and (ii) non-solvent/polymer (c13) and solvent/polymer (c23) using Hansen solubility parameters. Additionally, the effect of the ternary interaction term was not negligible in the model. Estimated ternary interaction parameters (c123) presented a linear relation with temperature and negative values, indicating that the solubility of the polymers in mixtures of solvent/non-solvent was higher than expected for single binary interaction. Finally, PES ternary systems exhibited higher influence of the ternary interaction parameter than PVDF systems.This research was funded by the Spanish Ministry of Economy, Industry and Competitiveness (MINECO-FEDER) through project CTM2016-75509-R and by the Spanish Research Agency through the projects X-MEM (PCI2018-092929, project call APCIN 2018) and PID2019-105827RBI00/AEI/10.13039/501100011033
Dynamic vehicle routing with time windows in theory and practice
The vehicle routing problem is a classical combinatorial optimization
problem. This work is about a variant of the vehicle routing problem
with dynamically changing orders and time windows. In real-world
applications often the demands change during operation time. New orders
occur and others are canceled. In this case new schedules need to be
generated on-the-fly. Online optimization algorithms for dynamical
vehicle routing address this problem but so far they do not consider
time windows. Moreover, to match the scenarios found in real-world
problems adaptations of benchmarks are required. In this paper, a
practical problem is modeled based on the procedure of daily routing of a
delivery company. New orders by customers are introduced dynamically
during the working day and need to be integrated into the schedule. A
multiple ant colony algorithm combined with powerful local search
procedures is proposed to solve the dynamic vehicle routing problem with
time windows. The performance is tested on a new benchmark based on
simulations of a working day. The problems are taken from Solomon’s
benchmarks but a certain percentage of the orders are only revealed to
the algorithm during operation time. Different versions of the MACS
algorithm are tested and a high performing variant is identified.
Finally, the algorithm is tested in situ: In a field study, the
algorithm schedules a fleet of cars for a surveillance company. We
compare the performance of the algorithm to that of the procedure used
by the company and we summarize insights gained from the implementation
of the real-world study. The results show that the multiple ant colony
algorithm can get a much better solution on the academic benchmark
problem and also can be integrated in a real-world environment
Fragility and compressibility at the glass transition
Isothermal compressibilities and Brillouin sound velocities from the
literature allow to separate the compressibility at the glass transition into a
high-frequency vibrational and a low-frequency relaxational part. Their ratio
shows the linear fragility relation discovered by x-ray Brillouin scattering
[1], though the data bend away from the line at higher fragilities. Using the
concept of constrained degrees of freedom, one can show that the vibrational
part follows the fragility-independent Lindemann criterion; the fragility
dependence seems to stem from the relaxational part. The physical meaning of
this finding is discussed. [1] T. Scopigno, G. Ruocco, F. Sette and G. Monaco,
Science 302, 849 (2003)Comment: 4 pages, 2 figures, 2 tables, 33 references. Slightly changed after
refereein
Gasification reactor engineering approach to understanding the formation of biochar properties
Operational reactor temperatures (spanning the reduction zone), pressure, and product gas composition measurements from a downdraft gasifier were compared against subsequent biochar elemental composition, surface morphology and PAH content. Pine feedstock moisture (FM), with values of 7% and 17% was the experimental variable. Moderately high steady-state temperatures were observed inside the reactor, with a ca. 50°C difference in how the gasifier operated between the two feedstock types. Both chars exhibited surface properties comparable to activated carbon, but the relatively small differences in temperature caused significant variations in biochar surface area and morphology: micropore area 584 m2.g-1 (FM7%) against 360 m2.g-1 (FM17%), and micropore volume 0.287 cm3.g-1 (FM7%) against 0.172 cm3.g-1 (FM17%). Differences in char extractable PAH content were also observed, with higher concentrations (187 μg.g-1 15 ± 18) when the gasifier was operated with FM7%, compared to 89 ± 19 μg.g-1 Σ16EPA PAH with FM17%. It is recommended that greater detail on operational conditions during biochar production should be incorporated as standard to future biochar characterisation research as a consequence of these results
Thermomechanical properties and shape-memory behavior of bisphenol a diacrylate-based shape-memory polymers
A series of acrylate-based shape-memory materials are synthesized from bisphenol A diacrylate monomers as crosslinking agents. Networks are synthesized by keeping constant the content of bisphenol A-based crosslinking agent and systematically varying the content ratio of different monofunctional chain builder monomers. The implications of the structure of bisphenol A-based monomers and the chemical structure and content of monofunctional monomers on thermomechanical properties are discussed. Thermomechanical properties are analyzed using dynamic mechanical analyses and mechanical properties are studied at room temperature and at the onset of the glass transition temperature. Shape-memory performances under isothermal and transient temperature conditions are also carried out. Tensile tests show excellent values of stress at break up to 45 and 15 MPa at room and high temperature, respectively. The measurements show excellent shape recovery and shape fixity ratios, Ëś95% and 97%, respectively. These materials also show very high recovery velocities under transient temperature conditions, up to 24% min-1, and very short recovery times, up to 1.5 s, under isothermal conditions in a water bath. The results confirm that networks synthesized from bisphenol A crosslinkers are promising shape-memory materials.Postprint (author's final draft
Heteroaromatic polyamides with Improved thermal and mechanical properties
We prepared high-performance aromatic copolyamides, containing bithiazole and thiazolo-thiazole groups in their main chain, from aromatic diamines and isophthaloyl chloride, to further improve the prominent thermal behavior and exceptional mechanical properties of commercial aramid fibers. The introduction of these groups leads to aramids with improved strength and moduli compared to commercial meta-oriented aromatic polyamides, together with an increase of their thermal performance. Moreover, their solubility, water uptake, and optical properties were evaluated in this work.Fondo Europeo de Desarrollo Regional and both the Spanish Ministerio de EconomĂa, Industria y Competitividad (MAT2017-84501-R) and the ConsejerĂa de EducaciĂłn, Junta de Castilla y LeĂłn (BU306P18) is gratefully acknowledged. M.T.L. also thankfully acknowledges the Spanish Ministerio de Ciencia e InnovaciĂłn (PID2019-108583RJ-I00/AEI/10.13039/501100011033
AR-Enhanced Human-Robot-Interaction - Methodologies, Algorithms, Tools
By using Augmented Reality in Human-Robot-Interaction scenariospropose it is possible to improve
training, programming, maintenance and process monitoring. AR Enhanced Human Robot Interaction
means it is possible to conduct activities not only in a training facility with physical robot(s) but also in a
complete virtual environment. By using virtual environments only a computer and possibly Head
Mounting Display is required. This will reduce the bottlenecks for with overbooked physical training
facilities. Physical environment for the activities with robot(s) will still be required, however using also
virtual environments will increase flexibility and human operator can focus on training more complicated
tasks. (C) 2016 The Authors. Published by Elsevier B.V.Partially funded by FP7 EU project LIAA (http://www.project-
leanautomation.eu/
Trajectories of internationalization: knowledge and national business styles in the making of two Dutch publishing multinationals, 1950-1990
The internationalization of business is the subject of an extensive
theoretical literature as well as a growing number of historical
studies. Historians have paid relatively little attention to the
development of multinationals in the service sector, and studies
about international publishing are especially scarce. This article
discusses the early internationalization of two Dutch publishing
firms, Kluwer (nowWolters Kluwer) and Elsevier (now Reed Elsevier)
and confronts these case histories with the evolutionary theory of
internationalization. The Dutch cases underline the important role
of experience, knowledge and learning as well as of the national
context in which companies develop. They also show that these
factors allow for very different trajectories of internationalization
within the same branch of business and the same country
Augmented Reality in Astrophysics
Augmented Reality consists of merging live images with virtual layers of
information. The rapid growth in the popularity of smartphones and tablets over
recent years has provided a large base of potential users of Augmented Reality
technology, and virtual layers of information can now be attached to a wide
variety of physical objects. In this article, we explore the potential of
Augmented Reality for astrophysical research with two distinct experiments: (1)
Augmented Posters and (2) Augmented Articles. We demonstrate that the emerging
technology of Augmented Reality can already be used and implemented without
expert knowledge using currently available apps. Our experiments highlight the
potential of Augmented Reality to improve the communication of scientific
results in the field of astrophysics. We also present feedback gathered from
the Australian astrophysics community that reveals evidence of some interest in
this technology by astronomers who experimented with Augmented Posters. In
addition, we discuss possible future trends for Augmented Reality applications
in astrophysics, and explore the current limitations associated with the
technology. This Augmented Article, the first of its kind, is designed to allow
the reader to directly experiment with this technology.Comment: 15 pages, 11 figures. Accepted for publication in Ap&SS. The final
publication will be available at link.springer.co
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