TiO2 Nanostructures and Nanocomposites for Sustainable Photocatalytic Water Purification

Water, together with energy and food, has been addressed as one of the main urgent problems of humanity. The conventional wastewater treatments suffer some limitations related to the effectiveness in decontamination (mechanical filtration), in the heavy use of chemicals (chlorination), or in elevation of operational costs and energy requirements (desalination and reverse osmosis). In this sense, new materials such as nanocomposites may overcome these issues taking advantage of the peculiar properties of materials at nanoscale. Research on novel nanotechnologies must bring advances in order to contrast and prevent water scarcity and pollution. In order to be effective, these nanotechnologies should run at low operational cost, even in places unequipped by strong infrastructures and in concert with conventional cheap methodologies

Atomic force microscopy investigation of the kinetic growth mechanisms of sputtered nanostructured Au film on mica: towards a nanoscale morphology control

The study of surface morphology of Au deposited on mica is crucial for the fabrication of flat Au films for applications in biological, electronic, and optical devices. The understanding of the growth mechanisms of Au on mica allows to tune the process parameters to obtain ultra-flat film as suitable platform for anchoring self-assembling monolayers, molecules, nanotubes, and nanoparticles. Furthermore, atomically flat Au substrates are ideal for imaging adsorbate layers using scanning probe microscopy techniques. The control of these mechanisms is a prerequisite for control of the film nano- and micro-structure to obtain materials with desired morphological properties. We report on an atomic force microscopy (AFM) study of the morphology evolution of Au film deposited on mica by room-temperature sputtering as a function of subsequent annealing processes. Starting from an Au continuous film on the mica substrate, the AFM technique allowed us to observe nucleation and growth of Au clusters when annealing process is performed in the 573-773 K temperature range and 900-3600 s time range. The evolution of the clusters size was quantified allowing us to evaluate the growth exponent 〈z〉 = 1.88 ± 0.06. Furthermore, we observed that the late stage of cluster growth is accompanied by the formation of circular depletion zones around the largest clusters. From the quantification of the evolution of the size of these zones, the Au surface diffusion coefficient was evaluated in D(T) = [(7.42 × 10−13) ± (5.94 × 10−14) m2/s]exp(−(0.33±0.04) eVkT). These quantitative data and their correlation with existing theoretical models elucidate the kinetic growth mechanisms of the sputtered Au on mica. As a consequence we acquired a methodology to control the morphological characteristics of the Au film simply controlling the annealing temperature and time

Solid-State Fabrication of Cu2O/CuO Hydroxide Nanoelectrode Array onto Graphene Paper by Thermal Dewetting for High-Sensitive Detection of Glucose

Nanostructures of Cu2O/CuO hydroxide suitable for the electrochemical determination of glucose are obtained by solid‐state dewetting of CuO layers 6, 8, and 31 nm thin deposited by sputtering onto 240 μm‐thick graphene paper. Solid‐state dewetting in nitrogen produces a partial decomposition of CuO into Cu2O and Cu. X‐ray diffraction patterns reveal the presence of high‐index crystallographic facets, which are reactive and useful toward glucose oxidation to gluconolactone. Typically, morphology studied by scanning electron microscopy reveals faceted nanoparticles with an average size below 200 nm. X‐ray photoelectron spectroscopy shows that the nanostructure surfaces of Cu2O and metallic copper exposed to natural ambient are promptly reoxidized and hydroxidized to a mixture of CuO and Cu(OH)2. Electrochemical characterization in amperometric mode reveals linear response to glucose concentration in the range from 50 to 10 × 10−3 m, sensitivity up to 83 μA cm−2 mm −1, and limit of detection up to 3.6 × 10−6 m. Good combination of low cost and simplicity of preparation with low limit of detection, high sensitivity, and wide linear range makes the proposed electrodes suitable for a variety of applications ranging from health to food and beverage industries

Acute idiopathic pericarditis with transient constriction [4]

The etiology and the clinical pattern of acute pericarditis change frequently and some classic assumption and descriptions are outdated. We report on a case of transient constrictive pericarditis in a healthy young man

Quantificazione del calcio coronarico (calcium score) attraverso l'utilizzo di nuove tecniche di imaging e suo ruolo prognostico in vari sottogruppi di pazienti

Coronary artery disease is the first cause of mortality in industrialized countries notwithstanding the diagnostic and therapeutic progresses. Electron beam computed tomography and multislice computed tomography with calcium score software seem to have an important role in the early diagnosis of coronary artery disease. Coronary calcium is associated with a high probability of subclinical atherosclerosis. In particular the area of calcification has a positive correlation with the histologically analyzed area of the atheromatous burden plaque. The pathophysiological mechanism may be that the calcium adherent to the plaque makes unstable the plaque with possible rupture. Several studies have analyzed the predictive value of calcium score in various subgroups of patients (asymptomatic, with chest pain, with diabetes) and they have confirmed the presence of large calcific deposits in subjects with a high cardiovascular risk. The correlation of the other risk factors with calcium score is unclear and whether this is due to genetic predisposition requires further investigation. © 2003 CEPI Srl

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

incidence and factors influencing retinal displacement in eyes treated for rhegmatogenous retinal detachment with vitrectomy and gas or silicone oil

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