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Uno de los materiales más importante en la historia de la humanidad es el hormigón, mezcla de cemento con áridos y agua. Trabajos recientes sugieren que los agregados tienen influencia en las propiedades de resistencia a compresión del hormigón y que las reacciones químicas que tienen lugar en la zona superficial, la mezcla, el desarrollo, y la morfología, son aspectos clave en su resistencia. Estudios modernos en caracterización de materiales dan relevancia a los conceptos estructurares y texturales, los cuales son de difícil captura debido a lo voluminoso del trabajo y a la imprecisión de los datos. De esta manera se constituye el comienzo de desarrollo de metodologías basadas en un enfoque sistémico para la caracterización del hormigón, que integran elementos tanto de técnicas como de tecnologías modernas, para la captura, procesamiento y extracción de información, tales como el análisis digital de imágenes, la morfología matemática y la geometría fractal. En este trabajo se explora la posibilidad de establecer, si a través del análisis digital de imágenes, elementos como: el área, la composición, la distribución espacial, el tamaño, el contorno, la superficie de los agregados, entre otros, tienen influencia en las propiedades de resistencia del hormigón, de manera que se pueda categorizar el hormigón a partir de dichas características obtenidas a través del procesamiento digital de imágenes.

This Special Issue of the InternationalJournal of Industrial Engineering and Management (IJIEM)features papers selected from the XVIII International Conference on Industrial Engineering and Operations Management (ICIEOM) This editorial paper introduces the special issue and summarizes 10 selected contributions that embrace researchers from Brazil, China, Colombia, Germany, and Portugal., Ovo posebno izdanje Međunarodnog časopisa za industrijsko inženjerstvo i mendžment (IJIEM) sadrži radove izabrane sa XVIII Međunarodne konferencije o industrijskom inženjerstvu i operacionom menadžmentu (ICIEOM). Rad urednika predstavlja ovo specijalno izdanje i daje sažetak 10 selektovanih priloga koji uključuju istraživače iz Brazila, Kine, Kolumbije, Nemačke i Portugala., (undefined)

The development and growth of the territory has for centuries been conditioned by the availability of resources on site. The minor architecture which is presented as a vast and varied repertoire of unique architectural forms, perfected over time to meet the needs of living places, is the repository of the formal and cultural testimonies that represent the integration between man and environment, which took place in a constant process of adaptation and enhancement of limits and resources in terms of climate, materials, soil morphology and geology. The “not only formal” result of this growth process is a consolidated iconography that summarizes the profound reasons for building through techniques developed according to the characteristics of the available materials and the needs of life and daily work, an absolute synthesis between form and function that gives rise to the repertoire of the lexicon of the architecture of a place and of the landscape. Starting from these reflections, the proposed study seeks to investigate the reasons for the constructive lexicon of some examples of vernacular architecture related to different contexts, identifying the reasons for the constructive choices in terms of relationships between the function of technical elements and construction characteristics; the purpose of this approach is to regulate constructive interventions in consolidated settlements of vernacular architecture by proposing a study methodology that highlights the rules and reasons for those constructive choices so that purely formal distortions and misunderstandings do not occur in current practices. The selected case studies are the rural settlements of Terzigno, a municipality in the province of Naples (Italy) on the slopes of Vesuvius and some of the rural settlements in the Danube Delta, in Romania.

The visual design elements and principles (VDEPs) can trigger behavioural changes and emotions in the viewer, but their effects on brain activity are not clearly understood. In this paper, we explore the relationships between brain activity and colour (cold/warm), light (dark/bright), movement (fast/slow), and balance (symmetrical/asymmetrical) VDEPs. We used the public DEAP dataset with the electroencephalogram signals of 32 participants recorded while watching music videos. The characteristic VDEPs for each second of the videos were manually tagged for by a team of two visual communication experts. Results show that variations in the light/value, rhythm/movement, and balance in the music video sequences produce a statistically significant effect over the mean absolute power of the Delta, Theta, Alpha, Beta, and Gamma EEG bands (p &lt, 0.05). Furthermore, we trained a Convolutional Neural Network that successfully predicts the VDEP of a video fragment solely by the EEG signal of the viewer with an accuracy ranging from 0.7447 for Colour VDEP to 0.9685 for Movement VDEP. Our work shows evidence that VDEPs affect brain activity in a variety of distinguishable ways and that a deep learning classifier can infer visual VDEP properties of the videos from EEG activity.

The effect of exposure of quartz samples to blue (470 ± 30 nm) and UV (365 ± 10 nm) light has been studied. Thermoluminescence, TL, Electron Paramagnetic Resonance, EPR, and Optically Stimulated Luminescence, OSL, have been considered. Looking at the OSL signal, while a reduction of the slow component is indeed induced by the UV exposure, a similar effect is observed, although with lower efficiency, under blue light exposure. Therefore, no conclusions can then be drawn as regards the effects induced on the OSL signal upon a change in the excitation wavelength. The effect of the UV and blue light exposure on the so called Slowly Bleachable Peak, SBP [1] , observed by TL at 340 °C, heating rate 5 °C/s, is presented. It is noticed a decrease of the SBP induced by UV exposure while no effect is caused by blue light exposure. A similar behaviour is detected when looking at the EPR signal of the [GeO4/Li+]0 center, that is reduced by the UV light, while no effect is seen after exposure to blue light. These results suggest that one of the electron sources originating the SBP can be identified as the [GeO4/Li+]0 center.

We report an experimental investigation by electron paramagnetic resonance of the doublet of lines split by ∼1.3 mT and centered on the E′γ; center resonance line in the spectrum of irradiated amorphous SiO2 . Commercial and sol-gel materials, some of which subjected to hydrogen-deuterium exchange, were investigated. Exposure to γ or Β rays at room temperature of the samples and subsequent thermal treatments were carried out to induce the defects and to study their thermal stability. In all the materials used the ratio between the signal of the E′γ centers and that of the 1.3 mT doublet is constant and independent of the OH and OD contents. Furthermore, the 1.3 mT doublet and the E′γ center feature similar thermal stability. These results support the attribution of the 1.3 mT doublet to the hyperfine interaction between the unpaired electron magnetic moment of the E′γ center and the nuclear magnetic moment of a second near neighboring 29Si atom. Our results also suggest that the E′γ site needs an appropriate surrounding of 29Si in back-bond configuration to experience this hyperfine interaction. © 2009 American Institute of Physics.

Combination regimens have shown superiority over single agents in the adjuvant treatment of resected pancreatic cancer (PC), but there are no data supporting definition of the best regimen. This work aimed to compare the efficacy and safety of mFOLFIRINOX, gemcitabine+capecitabine, and gemcitabine+nab/paclitaxel in PC patients. A meta-analysis was performed for direct comparison between trials comparing combination regimens and gemcitabine monotherapy. Subsequently, an indirect comparison was made between trials investigating the efficacy and safety of mFOLFIRINOX, gemcitabine+capecitabine, and gemcitabine+nab/paclitaxel because of the same control arm (gemcitabine). A total of three studies met the selection criteria and were included in our indirect comparison. Indirect comparisons for efficacy outcomes showed a benefit in terms of DFS (disease-free survival)/EFS (event-free survival)/RFS (relapse-free survival) for both mFOLFIRINOX versus gemcitabine+capecitabine (HR 0.69, 95% CI 0.52−0.91) and versus gemcitabine+nab/paclitaxel (HR 0.67, 95% CI 0.50−0.90). No significant advantage was registered for OS (overall survival). Indirect comparisons for safety showed an increase in terms of G3-5 AEs (with the exception of neutropenia) for mFOLFIRINOX versus gemcitabine+capecitabine (RR 1.24, 95% CI 1.03−1.50), while no significant differences were observed versus gemcitabine+nab/paclitaxel. According to our results, mFOLFIRINOX is feasible and manageable and could represent a first option for fit PC resected patients.

The extension of the pyrene ring from dimethyl 2,2′-(pyrene-1,6-diyl)dibenzoate derivatives by an intramolecular Friedel–Crafts acylation can be realized in an efficient and regioselective manner using triflic acid as proton source. Naphtho-tetracenone derivatives are obtained in high yields at room temperature while Bis-tetracene-diones are prepared upon heating. Both products display interesting fluorescence properties in the visible range with quantum yields varying from 50 to 60 %.

Perylenediimides (PDIs) are among the best performing organic luminescent materials, both in terms of emission efficiency and chemical and photochemical stability because of their rigid, symmetric and planar structure; however, they exhibit very small Stokes shifts. The sizeable reabsorption of the emitted light limits the performances of perylenediimides in imaging applications and luminescent solar concentrators. Perylenemonoimides (PMIs) having an electron donating substituent in one of the free peri positions feature larger Stokes shift values while retaining high chemical stability. The selection of the most appropriate donor, both in terms of electron donating capability and steric demand, boosts emission efficiency and limits reabsorption losses. The synthesis, optical spectroscopy, molecular orbital computations, UPS, electrochemical, spectroelectrochemical, and multinuclear NMR investigation of a series of PMI derivatives functionalized with donors having different electronic characteristics and steric demands are discussed. Results are relevant for the fabrication of single layer plastic luminescent solar concentrators (LSC).

This paper focuses on modelling on-street parking search time by using FCD data coming from probe vehicles. It is based on data detected by probe vehicles, which allow to identify the typical spiral around the destination that vehicles perform in the final part of the trip to find a parking place. The proposed model is suitable to be used either in real-time to support user information and dynamic routing, or off-line for a better assessment of transport plans. A real-size application to the city of Rome is presented to show the promising results obtained for the estimation of parking search time in urban areas.

The identification of the center acting as electron source for the well-known 110 °C thermoluminescence (TL) peak of quartz is of fundamental importance for practical applications in dating and dosimetry. This TL peak was studied in parallel with the electron paramagnetic resonance (EPR) signal of the [GeO 4 ] − center on natural colourless quartz irradiated at room temperature. Immediately after irradiation, the signals of the 110 °C TL peak and of [GeO 4 ] − center decay exponentially in the same way, yielding a lifetime of 50.4 ± 0.9 min at room temperature. Besides, we acquired the isothermal decay curves for the 110 °C TL peak and [GeO 4 ] − center at different temperatures (the samples were held at the selected temperature in the range of 260–308 K). The lifetimes extracted by the isothermal decays were plotted as a function of reciprocal temperature, revealing again the same behavior of the 110 °C TL peak and [GeO 4 ] − center, both characterized by activation energies very close of 0.76 ± 0.07 eV and 0.77 ± 0.07 eV, respectively. All results of the present work clearly show the role of electron source of [GeO 4 ] − center in the emission mechanism of the 110 °C TL peak in quartz.

The technological application of sensitized upconversion based on triplet-triplet annihilation (TTA) requires the transition from systems operating in liquid solutions to solid-state materials. Here, we demonstrate that the high upconversion efficiency reported in hyper-cross-linked nanoparticles does not originate from residual mobility of the embedded dyes as it happens in soft hosts. The hyper-reticulation from one side blocks the dyes in fixed positions, but on the other one, it suppresses the nonradiative spontaneous decay of the triplet excitons, reducing intramolecular relaxations. TTA is thus enabled by an unprecedented extension of the triplet lifetime, which grants long excitons diffusion lengths by hopping among the dye framework and gives rise to high upconversion yield without any molecular displacement. This finding paves the way for the design of a new class of upconverting materials, which in principle can operate at excitation intensities even lower than those requested in liquid or in rubber hosts.

We present a study on the effects of an isothermal annealing treatment on a-SiO 2 having a significant content of silanol hydride groups (Si-H). We examined the properties of the IR absorption bands of silanol (Si-OH) and silicon hydride groups as a function of the duration of the thermal treatment. We showed that the Si-OH and Si-H groups contents decrease in a linearly correlated way. The annealing dynamics suggest that the two species are close to each other in the amorphous network. We showed that the profile of the silanol groups absorption band is the same as that observed in other commercial a-SiO 2 materials, irrespectively of the concomitant presence of nearby Si-H groups, and, moreover, it does not change during the annealing treatment. This set of evidences supports the conclusion that silanol groups are organized in clusters in the a-SiO 2 network. Finally, present data provide an unprecedented characterization of the Si-H IR absorption band. It results that the profiles of the IR and Raman activities of silicon hydride groups closely coincide. © 2011 EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg.