Preparation of Nano-TiO2/Diatomite Composites by Non-hydrolytic Sol–Gel Process and its Application in Photocatalytic Degradation of Crystal Violet

Silicon - The dispersion of anatase TiO2 on diatomic material was a prospective route to avoid agglomerates of these particles. In this work, the TiO2/diatomite composites were prepared using a...     

Influence of functionalized reduced graphene oxide and compatibilizer on mechanical,thermal and morphological properties of polypropylene/polybutene-1 (PP/PB-1) blends

Polypropylene/Polybutene-1 (PP/PB-1) blends and nanocomposites containing pristine partially reduced graphene oxide (rGO) and chemically functionalized rGO (FrGO) with silane, and silane grafted with 1,12-dodecanediamine and 1,12-dodecanediol were studied. The effects of the chemical treatments on structure and thermal stability of rGO were first thoroughly investigated. Attenuated total reflectance Fourier infrared (ATR-FTIR) spectroscopy analyses of FrGO evidenced the existence of functional groups on rGO after each chemical treatment, while X-ray diffraction (XRD) results confirmed the effectiveness of the interlayer grafting process through shifting of the basal spacings as witnessed by increased d₀₀₂ values. Furthermore, thermogravimetric analysis (TGA) revealed that the functionalization of rGO resulted in improved thermal stability of rGO demonstrated by its increased thermal degradation temperature. The PP/PB-1 blends and their rGO and FrGO based nanocomposites were prepared by melt blending masterbatch process in the presence of an acrylic acid modified polypropylene compatibilizer (PP-g-AA). Mechanical testing showed that Young’s modulus and tensile strength of the PP/PB-1 blends significantly improved after co-addition of FrGO and PP-g-AA to form the nanocomposites, but it also endowed a drastic decrease in their elongation at break and especially in their impact strength. XRD analyses attested the successful formation of intercalated nanocomposites, and scanning electron microscopy (SEM) examinations disclosed a two-phase morphology consisting of PB-1 dispersed droplets in the PP matrix. SEM also indicated that the incorporation of PP-g-AA into the blends and the nanocomposites contributed to enhanced adhesion and dispersion of PB-1 phase and FrGO nanoparticles within the polymer matrix.     

From use case maps to executable test procedures: a scenario-based approach

Software and Systems Modeling - Testing embedded systems software has become a costly activity as these systems become more complex to fulfill rising needs. Testing processes should be both...     

Single-rate near lossless compression of animated geometry

Representing mesh geometry in local rather than the world coordinate systems is very useful in many 3D animation processing applications. One can investigate the representation of vertex locations relative to a local coordinate frame (LCF) in the compression of dynamic 3D meshes. Unlike the world coordinates, which scatter in a wide range and show non-linear behavior of the vertices, the local coordinates exhibit a large clustering behavior of the vertex over time. This property is very useful for exploiting a large coherence over the vertex trajectory and between neighboring vertices. In this paper, we discuss the use of the LCF in static and animated mesh encoding and we introduce a new connectivity-guided predictive scheme for single-rate compression for animated meshes. The proposed geometry encoding strategy is based on a region growing encoding order, and only the differences between original and predicted locations are encoded in a local coordinate system, which splits into two tangential and one normal components. The approach is simple, efficient, and well-suited for real time applications.     

Bin weather data for five climatic zones of Morocco

ABSTRACT

The Bin method is one of the well-known and accurate steady-state approach to predict heating and cooling energy consumption of buildings. The application of this method requires detailed ambient temperature bin data. In this paper, the dry-bulb temperature bin data for five climatic zones of Morocco was generated. It was calculated from ?12°C to 45°C with 3°C increments in six daily 4?h shifts (1–4, 5–8, 9–12, 13–16, 17–20 and 21–24?h) for Marrakech, Ifrane, Fez, Errachidia and Agadir. The bin data given in this paper may have the positive impact on building energy efficiency in Morocco.     

Polyol Mediated Solvothermal Synthesis and Characterization of CuIn<Subscript>(1−x)</Subscript>Ga<Subscript>x</Subscript>S<Subscript>2</Subscript> Nanocrystals

Gallium-substituted copper indium sulfide (CuIn_(1?x)Ga_xS₂) nanoparticles have been synthesized by a convenient solvothermal method without usage of surfactants or toxic reductants such as hydrazine. Thiourea, sodium hydroxide, CuCl₂·2H₂O, InCl₃ and GaCl₃ were used as starting materials and ethylene glycol as solvent and reducing agent. The reactions were performed at 200 °C for 16 h. Effect of sodium hydroxide on the reaction products is analyzed. The powders are mainly characterized by X-ray diffraction, Raman spectroscopy, transmission electron microscopy, BET surface area measurements and UV–Vis absorption spectroscopy. The results show that the gallium is successfully incorporated into the chalcopyrite crystal structure. The homogeneous powders obtained are constituted of nanoparticles with sizes in the range 20–30 nm and exhibit a specific surface area close to 65 m²/g. Further, the possible mechanism for the formation of CuIn_(1?x)Ga_xS₂ nanocrystals is explained. The optical band gap energies of the nanoparticles were in the range 1.48–1.75 eV.     

Experimental platform for waveform optimization in passive UHF RFID systems

The article presents an experimental platform, so called “RFID Waveformer,” dedicated to the study of waveform optimization in the radio frequency identification (RFID) context. It is a flexible solution that enables waveform design and their energetic performance evaluation in a ultra high frequency (UHF) RFID link following the ISO‐18000 GEN2 standard protocol. It consists of a reader emulated by a LabVIEW interface controlling radiofrequency laboratory instruments, which perform real time tag response detection. Its interconnection with MATLAB routines enables the design and the evaluation of arbitrarily shaped RFID waveforms. In this article, for illustration, three waveforms are tested with RFID Waveformer in a complex propagation environment: pulsed wave (PW) and time reversal (TR) modes compared to the traditional continuous wave (CW) mode. Experimental results show that both PW and TR modes improve the energetic efficiency of the forward link and so the RFID read range compared to CW mode. Furthermore, TR presents the optimal efficiency in complex propagation medium. The RFID Waveformer enables tag response detection in the three modes offering ease of use and repeatability of measurements. The RFID Waveformer being not limited to the scenario considered in this article, it is a versatile solution extendable to other contexts.     

Proteome of the anterior segment structure in relation to glaucoma

Glaucoma is a heterogeneous group of diseases that is characterized by structural changes in the optic nerve head, which can lead to blindness. Although the endpoint pathology in glaucoma is damage to the retinal ganglion cells and optic nerve, glaucoma also involves tissues in the anterior segment. The pathogenesis of glaucoma has been widely studied; however, the mechanisms causing it are not completely understood. Proteomic approaches have provided new insights into the pathogenesis of glaucoma. These technologies have helped to identify changes in the extracellular matrix and alterations in cytoskeletal proteins of the trabecular meshwork, in addition to the role of autoimmunity and oxidative damage. In this review, we describe the proteomic approaches that have been used to study protein alterations in the anterior segment as related to glaucoma in addition to some of the mechanisms that these technologies have helped to elucidate.