Band Gap Modeling of Different Ternary and Quaternary Alumina Garnet Phases Y3(AlXGa1-X)5O12 (YAGG) and Lu3(AlXGa1-X)5O12 (LuAGG). A Semiempirical Approach

A further generalization to quaternary oxide systems of the modeling equation of optical band gap values, based on the semiempirical correlation between the differences in the electronegativity of oxygen and the average cationic electronegativity, proposed some years ago, has been carried out by expanding the approach recently employed for ternary mixed oxides. The choice of oxide polymorphs and their influence on the fitting procedure of an experimental data set is evidenced by a detailed discussion of the fitting process of the literature's experimental band gap data pertaining two quaternary oxide systems of the garnet family, namely, Y3(AlxGa1-x)5O12 (YAGG) and Lu3(AlxGa1-x)5O12 (LuAGG), playing an important role in several engineering applications. The two investigated systems, moreover, span a quite large range of band gap energy values (from similar to 5.5 to similar to 7.5 eV), as a function of the Al/Ga ratio, allowing a rigorous test of the proposed modeling equation. Based on the wide existing literature on the presence of excitonic effects in the investigated systems some empirical correlations between an optical gap and a band gap in the presence of excitonic effects are suggested, too, which could provide some rationale to overcome the discrepancies frequently encountered in comparing band gap values reported in the literature for the same materials. The results of this work confirm the ability of this semiempirical approach in providing good agreement between experimental and theoretical band gap values also for very complex systems, where more sophisticated density functional theory-based methods face some difficulties in predicting the correct values

A Generalized Semiempirical Approach to the Modeling of the Optical Band Gap of Ternary Al-(Ga, Nb, Ta, W) Oxides Containing Different Alumina Polymorphs

A generalization of the modeling equation of optical band gap values for ternary oxides, as a function of cationic ratio composition, is carried out based on the semiempirical correlation between the differences in the electronegativity of oxygen and the average cationic electronegativity proposed some years ago. In this work, a novel approach is suggested to account for the differences in the band gap values of the different polymorphs of binary oxides as well as for ternary oxides existing in different crystalline structures. A preliminary test on the validity of the proposed modeling equations has been carried out by using the numerous experimental data pertaining to alumina and gallia polymorphs as well as the crystalline ternary Ga(1-x)AlxO3 polymorphs (α-Ga(1-x)AlxO3 and β-Ga(1-x)AlxO3) covering a large range of optical band gap values (4.50-8.50 eV). To make a more rigorous test of the modeling equation, we extended our investigation to amorphous ternary oxides anodically formed on Al-d-metal alloys (Al-Nb, Al-Ta, and Al-W) covering a large range of d-metal composition (xd-metal ≥ 0.2). In the last case, the novel approach allows one to overcome some difficulties experienced in fitting the optical band gap dependence from the Al-d-metal mixed anodic oxide composition as well as to provide a rationale for the departure, at the lowest d-metal content (xd-metal < 0.2), from the behavior observed for anodic films containing higher d-metal content

Comparing 2D pictures with 3D replicas for the digital preservation and analysis of tangible heritage

In this paper, we present two experiments designed to compare 2D digital pictures and 3D digital replicas of artefacts, to understand how differently these media facilitate the perception and understanding of our past. Archaeologists and museum experts have commonly used 2D digital pictures to preserve and study artefacts. Recently these scholars have also started to use 3D digital archives for their studies. Yet we still need to determine how these two formats (2D vs 3D) affect the perception of our past. Results to our experiments point to 3D digital replicas of artifacts as more effective means to digitally preserve tangible cultural heritage, since 3D multi-visualization augments the perception of physical characteristics of the artifacts allowing a more embodied experience with these objects. Our experiments also suggest that multi-visualization (i.e., point-cloud, mesh, and color information) helps the viewers to overcome their personal conceptualization of specific objects.This is the author accepted manuscript. The final version is available from Taylor & Francis via http://dx.doi.org/10.1080/09647775.2015.104251

3D printing and immersive visualization for improved perception of ancient artifacts

This article investigates the use of 3D immersive virtual environments and 3D prints for interaction with past material culture over traditional observation without manipulation. Our work is motivated by studies in heritage, museum, and cognitive sciences indicating the importance of object manipulation for understanding present and ancient artifacts. While virtual immersive environments and 3D prints have started to be incorporated in heritage research and museum displays as a way to provide improved manipulation experiences, little is known about how these new technologies affect the perception of our past. This article provides first results obtained with three experiments designed to investigate the benefits and tradeoffs in using these technologies. Our results indicate that traditional museum displays limit the experience with past material culture, and reveal how our sample of participants favor tactile and immersive 3D virtual experiences with artifacts over visual non-manipulative experiences with authentic objects. This paper is part of a larger study on how people perceive ancient artifacts, which was partially funded by the University of California Humanities Network and the Center for the Humanities at the University of California, Merced.This is the author accepted manuscript. The final version is available from MIT Press via http://dx.doi.org/10.1162/PRES_a_0022

One-step electrodeposition of superhydrophobic coating on 316L stainless steel

Superhydrophobic coatings were fabricated through a one-step electrochemical process onto the surface of 316L stainless steel samples. The presence of hierarchical structures at micro/ nanoscale and manganese stearate into the coatings gave superhydrophobicity to the coating, with contact angle of ~160◦, and self-cleaning ability. Corrosion resistance of 316L samples was also assessed also after the electrodeposition process through Electrochemical Impedance Spectra recorded in an aqueous solution mimicking seawater condition

Enhancing corrosion resistance of anodized AA7075 alloys by electrodeposition of superhydrophobic coatings

Electrodeposition of superhydrophobic coatings was carried out on anodized AA7075 alloy to further enhance its corrosion resistance. Several compositions of electrodeposition bath were studied to find the most suitable one to obtain superhydrophobic coating. Scanning Electron Microscopy and Fourier Transform Infrared Spectroscopy proved the deposition of coatings with different characteristics depending on electrodeposition bath composition. Highest contact angle value (∼ 160°) and highest corrosion resistance were obtained for the Mn-containing coating, proving also high stability after 21 days of immersion in an aqueous solution mimicking seawater. Experiments on flat pellet samples were carried out to split the effect due to the material composition with respect to that due to the coating morphological features, estimating the vacuum fraction of the superhydrophobic coatings according to the Cassie Baxter model

Can the intraprostatic concentration of epidermal growth factor influence the variance of serum prostate specific antigen levels in patients with benign prostatic hyperplasia?

Purpose: Except for prostate volume, little is known about the factors influencing serum prostate specific antigen (PSA) levels. Considering that dihydrotestosterone and epidermal growth factor are regulators of the proliferation and differentiation in the epithelial component of human prostate tissue and that PSA is produced only by the epithelial cells of the gland, studies were performed on patients with a histological diagnosis of benign prostatic hyperplasia (BPH) to establish whether a significant association exists between the intraprostatic concentration of dihydrotestosterone or epidermal growth factor and serum PSA levels. Materials and Methods: A total of 20 patients with BPH who had not been previously treated were part of a larger study on the correlation among PSA, prostate volume and age, and were evaluated according to the algorithm in the guidelines of the international consultation on BPH. All men underwent open suprapubic prostatectomy to enucleate the entire adenoma and in each case sections were made in the periurethral, subcapsular and intermediate zones of the BPH tissue. Dihydrotestosterone and epidermal growth factor concentrations were evaluated by radioimmunoassay in the periurethral zone and in total BPH tissue. Results: In these 20 patients with BPH serum PSA levels were significantly associated with epidermal growth factor but not with dihydrotestosterone concentrations in total BPH tissue (r = 0.7762, p = 0.00002836 and r = 0.3923, p = 0.0956307, respectively). A stronger association was found between PSA levels and the periurethral concentration of epidermal growth factor and dihydrotestosterone (r = 0.8117, p = 0.000005 and r = 0.5656, p = 0.0098326, respectively). On the contrary, epidermal growth factor and dihydrotestosterone were not significantly associated with prostate volume (p = 0.957415 and p = 0.531439, respectively). Conclusions: To our knowledge this study is the first report in the literature to demonstrate an association between serum PSA, and dihydrotestosterone and epidermal growth factor levels, particularly in the periurethral zone of human BPH tissue. These data suggest the importance of epidermal growth factor and dihydrotestosterone in influencing serum PSA levels

Project "Biodiversity MARE Tricase": a biodiversity inventory of the coastal area of Tricase (Ionian Sea, Italy) – Mollusca: Heterobranchia

The marine biodiversity of the Tricase coastal area (Ionian Sea, Italy) was investigated at the MARE Outpost (Avamposto MARE) between 2016 and 2017, with the help of citizen scientists and trained taxonomists. Among the most interesting groups encountered, heterobranch molluscs deserve a special mention. Altogether, 268 specimens were ascribed to this group and referred to 49 taxa. Notwithstanding the extensive literature on Mediterranean heterobranchs, two species proved to be new to the Italian coasts, the records of eight species represented their easternmost sightings in the Mediterranean Sea, and 13 taxa represented new records for the Ionian Sea. In addition, several feeding habits and phenological events were new to science. Although the European Union's Marine Strategy Framework Directive lists "Biodiversity is maintained" as the first descriptor in achieving "Good Environmental Status", our results highlighted the presence of conspicuous gaps in the knowledge of species distribution, taxonomy and ecology of heterobranch molluscs, indicating the necessity of even small-scale species checklists to understand biodiversity changes in worldwide biota

The impact of temporal synchronisation imprecision on TRF analyses

Human sensory perception requires our brains to extract, encode, and process multiple properties of the sensory input. In the context of continuous sensory signals, such as speech and music, the measured electrical neural activity synchronises to properties such as the acoustic envelope, a phenomenon referred to as neural tracking. The ability of measuring neural tracking with non-invasive neurophysiology constitutes an exciting new opportunity for applied research. For example, it enables the objective assessment of cognitive functions in challenging cohorts and environments by using pleasant, everyday tasks, such as watching videos. However, neural tracking has been mostly studied in controlled, laboratory environments guaranteeing precise synchronisation between the neural signal and the corresponding labels (e.g., speech envelope). There exist various challenges that could impact such a temporal precision in, for instance, out-of-lab scenarios, such as technology (e.g., wireless data acquisition), mobility requirements (e.g., clinical scenarios), and the task (e.g., imagery). Aiming to address this type of challenge, we focus on the predominant scenario of continuous sensory experiments involving listening to speech and music. First a temporal response function analysis is presented on two different datasets to assess the impact of trigger imprecision. Second, a proof-of-concept re-alignment methodology is proposed to determine potential issues with the temporal synchronisation. Finally, a use-case study is presented that demonstrates neural tracking measurements in a challenging scenario involving older individuals with neurocognitive decline in care homes. Significance Statement Human cognitive functions can be studied by measuring neural tracking with non-invasive neurophysiology as participants perform pleasant, everyday tasks, such as listening to music. However, while recent work has encouraged the use of this approach in applied research, it remains unclear how robust neural tracking measurements can be when considering the methodological constraints of applied scenarios. This study determines the impact of a key factor for the measurement of neural tracking: the temporal precision of the neural recording. The results provide clear guidelines for future research, indicating what level of imprecision can be tolerated for measuring neural tracking with speech and music listening tasks in both laboratory and applied settings. Furthermore, the study provides a strategy to assess the impact of imprecision in the synchronisation of the neural recording, thus developing new tools for applied neuroscience