Application of a new photocatalytic nanomaterial obtained by Pulse Laser Ablation for Polychrome Paintings Conservation: a feasibility study

This works aims to present a preliminary study about the application on painting of TiO2 nanoparticles for self-cleaning and protective purposes. We firstly assessed the photocatalytic activity of the TiO2 nanoparticles, obtained by Pulsed Laser Ablation, by the discoloration of dye. After, the colloidal dispersion is applied to painting samples prepared in laboratory, according to old recipes and using the most-used historical binders and pigments, in order to verify the cleaning efficiency by discoloration of the chromatic markers. The spectrophotometric analysis is performed studying the Spectral Reflectance Factor trend and the color coordinates

PENERAPAN MODEL EXPLICIT INSTRUCTION PADA PEMBELAJARAN SENI TARI UNTUK MENINGKATKAN MINAT BELAJAR SISWA.

Judul penelitian ini adalah Penerapan Model Explicit Instruction Pada Pembelajaran Seni Tari Untuk Meningkatkan Minat Belajar Siswa (Studi Eksperimen Pada Siswa Kelas VIII-F SMP Negeri 3 Lembang). Permasalahan yang diangkat ialah bagaimana menumbuhkan minat belajar siswa melalui pembelajaran tari dengan tiga pertanyaan penelitian diantaranya, (1) Bagaimana minat belajar siswa terhadap pembelajaran seni tari sebelum diterapkannya model Explicit Instruction di kelas VIII-F SMP Negeri 3 Lembang?, (2) Bagaimana proses pembelajaran untuk meningkatkan minat belajar siswa terhadap pembelajaran seni tari melalui model Explicit Instruction di kelas VIII-F SMP Negeri 3 Lembang?, (3) Bagaimana hasil pembelajaran Seni Tari untuk meningkatkan minat belajar siswa setelah diterapkannya model Explicit Instruction dikelas VIII-F SMP Negeri 3 Lembang?. Metode penelitian yang digunakan adalah metode eksperimen pendekatan kuantitatif dan teknik pengumpulan data diantaranya studi pustaka, observasi, wawancara, tes, dan dokumentasi. Hasil analisis data dan temuan mengenai minat belajar siswa sebelum menggunakan model explicit instruction sangat rendah karena model pembelajaran yang digunakan belum tepat, peningkatan minat terlihat pada saat proses pembelajaran, kemudian uji t tabel yang menyatakan bahwa t_tes 4 > t_tab1,729. Hal ini membuktikan bahwa model explicit instruction sangat signifikan untuk meningkatkan minat belajar siswa dan dapat di jadikan sebagai salah satu rekomendasi untuk pembelajaran tari terutama dalam meningkatkan minat belajar siswa

Nanoporous Ge electrode as a template for nano-sized (<5 nm) Au aggregates

none8In this paper we present the extremely peculiar electrical properties of nanoporous Ge. A full and accurate electrical characterization showed an unexpected and extremely high concentration of positive carriers. Electrochemical analyses showed that nanoporous Ge has improved charge transfer properties with respect to bulk Ge. The electrode behavior, together with the large surface-to-volume ratio, make nanoporous Ge an efficient nanostructured template for the realization of other porous materials by electrodeposition. The pores were efficiently decorated by Au nanoparticles of diameter as low as 1–5 nm, prepared by electrochemical deposition. These new results demonstrate the potential and efficient use of nanoporous Ge as a nanostructured template for nano-sized Au aggregates, opening the way for the realization of innovative sensor devices.openG.Impellizzeri; L.Romano; B.Fraboni; E. Scavetta; F.Ruffino; C.Bongiorno; V. Privitera; M.G.GrimaldiG.Impellizzeri; L.Romano; B.Fraboni; E. Scavetta; F.Ruffino; C.Bongiorno; V. Privitera; M.G.Grimald

Correction: Enhancing carrier generation in TiO2 by a synergistic effect between plasmon resonance in Ag nanoparticles and optical interference

Silver nanoparticles have been embedded at a few nanometer distance from the free surface of titania/silica multilayers using low energy ion beam synthesis. Transmission electron microscopy shows the presence of 3 nm-sized crystalline particles. Reflectance spectroscopy on these composite substrates shows an increase of the light capture efficiency in the visible range. This behaviour is interpreted as a synergistic effect between plasmon polariton resonance and Fabry–Perot interferences. Plasmon-resonant Raman spectroscopy is deeply used to analyze, on one hand confinement of vibrations and electronic excitations in Ag NPs, and on the other hand coupling of polar TiO2 phonons with injected photo-generated carriers. It is shown how these new Ag/TiO2 nanocomposite films appear as very promising to enhance the efficiency and enlarge the spectral sensitivity of plasmo-electronics devices

Synthesis of ZnO/PMMA nanocomposite by low-temperature atomic layer deposition for possible photocatalysis applications

Zinc oxide is one of the most widely used semiconductors, thanks to its shallow band-gap of 3.3 eV, low cost, inertness, and abundance in nature. On the other hand, poly (methyl methacrylate) (PMMA) is a common thermoplastic material used in many applications namely because of its transparency, environmental stability, and low cost. The realization of novel inorganic/polymeric hybrid nanomaterials is appealing, being beneficial in a variety of applications including photocatalysis, sensing, energy harvesting and storage, and optoelectronics, but also challenging. In this work, ZnO and PMMA were combined using the atomic layer deposition (ALD) technique. The morphology of the samples was evaluated by scanning electron microscopy (SEM), while the crystallinity has been investigated using X-ray diffraction (XRD) analyses. In order to give a proof of concept of a possible application of the materials synthetized, the photocatalytic activity of the nanocomposites has been tested by the degradation of two organic pollutants in water: methylene blue (MB) dye and sodium lauryl sulfate (SDS), an anionic surfactant. The results have shown that all samples are active in the removal of both pollutants (i.e., MB and SDS), opening the route for the application of the proposed nanocomposites in water treatment.peer-reviewe

Suitability of different titanium dioxide nanotube morphologies for photocatalytic water treatment

Photocatalysis has long been touted as one of the most promising technologies for environmental remediation. The ability of photocatalysts to degrade a host of different pollutants, especially recalcitrant molecules, is certainly appealing. Titanium dioxide (TiO2) has been used extensively for this purpose. Anodic oxidation allows for the synthesis of a highly ordered nanotubular structure with a high degree of tunability. In this study, a series of TiO2 arrays were synthesised using different electrolytes and different potentials. Mixed anatase-rutile photocatalysts with excellent wettability were achieved with all the experimental iterations. Under UVA light, all the materials showed significant photoactivity towards different organic pollutants. The nanotubes synthesised in the ethylene glycol-based electrolyte exhibited the best performance, with near complete degradation of all the pollutants. The antibacterial activity of this same material was similarly high, with extremely low bacterial survival rates. Increasing the voltage resulted in wider and longer nanotubes, characteristics which increase the level of photocatalytic activity. The ease of synthesis coupled with the excellent activity makes this a viable material that can be used in flat-plate reactors and that is suitable for photocatalytic water treatment.peer-reviewe

The incidence of hip, forearm, humeral, ankle, and vertebral fragility fractures in Italy: results from a 3-year multicenter study

INTRODUCTION: We aimed to assess the incidence and hospitalization rate of hip and "minor" fragility fractures in the Italian population. METHODS: We carried out a 3-year survey at 10 major Italian emergency departments to evaluate the hospitalization rate of hip, forearm, humeral, ankle, and vertebral fragility fractures in people 45 years or older between 2004 and 2006, both men and women. These data were compared with those recorded in the national hospitalizations database (SDO) to assess the overall incidence of fragility fractures occurring at hip and other sites, including also those events not resulting in hospital admissions. RESULTS: We observed 29,017 fractures across 3 years, with hospitalization rates of 93.0% for hip fractures, 36.3% for humeral fractures, 31.3% for ankle fractures, 22.6% for forearm/wrist fractures, and 27.6% for clinical vertebral fractures. According to the analyses performed with the Italian hospitalization database in year 2006, we estimated an annual incidence of 87,000 hip, 48,000 humeral, 36,000 ankle, 85,000 wrist, and 155,000 vertebral fragility fractures in people aged 45 years or older (thus resulting in almost 410,000 new fractures per year). Clinical vertebral fractures were recorded in 47,000 events per year. CONCLUSIONS: The burden of fragility fractures in the Italian population is very high and calls for effective preventive strategies

Ag/ZnO/PMMA nanocomposites for efficient water reuse

This work attempts to produce photocatalytic surfaces for large-scale applications by depositing nanostructured coatings on polymeric substrates. ZnO/poly(methyl methacrylate) (PMMA) composites were prepared by low-temperature atomic layer deposition (ALD) of ZnO on PMMA substrates. In addition, to increase the photocatalytic and antibacterial activities of ZnO films, Ag nanoparticles were added on ZnO surfaces using plasma-enhanced ALD. The morphology, crystallinity, and chemical composition of the specimens were meticulously examined by scanning and transmission electron microscopies, energy-dispersive X-ray spectroscopy, and X-ray diffraction analyses. The noteworthy photocatalytic activity of the nanocomposites was proved by the degradation of the following organic pollutants in aqueous solution: methylene blue, paracetamol, and sodium lauryl sulfate. The antibacterial properties of the samples were tested using Escherichia coli as a model organism. Moreover, the possible toxic effects of the specimens were checked by biological tests. The present results unambiguously indicate the Ag/ZnO/PMMA nanocomposite as a powerful tool for an advanced wastewater treatment technology.peer-reviewe

Defects in semiconductors

This volume, number 91 in the Semiconductor and Semimetals series, focuses on defects in semiconductors. Defects in semiconductors help to explain several phenomena, from diffusion to getter, and to draw theories on materials' behavior in response to electrical or mechanical fields. The volume includes chapters focusing specifically on electron and proton irradiation of silicon, point defects in zinc oxide and gallium nitride, ion implantation defects and shallow junctions in silicon and germanium, and much more. It will help support students and scientists in their experimental and theore

TiO2-coated nanostructures for dye photo-degradation in water

The photocatalytic efficiency of a thin-film TiO2-coated nanostructured template is studied by dye degradation in water. The nanostructured template was synthesized by metal-assisted wet etching of Si and used as substrate for the deposition of a thin film of TiO2 (10 nm thick) by atomic layer deposition. A complete structural characterization was made by scanning and transmission electron microscopies. The significant photocatalytic performance was evaluated by the degradation of two dyes in water: methylene blue and methyl orange. The relevance of the reported results is discussed, opening the route toward the application of the synthesized nanostructured TiO2 for water purification