Hydrothermal synthesis of mesoporous VO2·½(H2O) nanosheets and study of their electrical properties

Layered sheet-like nanocrystalline VO₂·½(H₂O) has been synthesized by hydrothermal process using V₂O₅ as vanadium source and 2-phenylethylamine as a reducing agent and a structure-directing template. Techniques X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and nitrogen adsorption/desorption isotherms have been used to characterize the structure, morphology and composition of the materials. Electrical conductivity measurements showed that the as synthesized VO₂·½(H₂O) nanosheets has a conductivity value which goes from 75 × 10^?6 Ω^?1 cm^?1 at 298 K, to 68 10^?5 Ω^?1 cm^?1 at 386 K with activation energy of 0.24 eV.     

A local-spectral fuzzy segmentation for MSG multispectral images

In this article, a segmentation approach for cloud detection in Meteosat Second Generation (MSG) multispectral images is proposed. The proposed algorithm uses recursive segmentation that dynamically reduces the number of classes. This algorithm consists of two steps. First, an initial segmentation of the image is obtained using local fuzzy clustering. The clustering algorithm is formulated by modifying the similarity measure of the standard fuzzy c-means (FCM) algorithm. The new similarity function includes the spectral information as well as the homogeneity and spatial clustering information of each considered pixel. In the second step, a hierarchical region-merging process is used to reduce the number of image clusters. At each iteration, the segmentation algorithm proceeds with a new partition until the final result of the segmentation is obtained. The proposed method has been tested using synthetic and MSG images. It yields a compact and coherent segmentation map, with a satisfactory reproduction of the image contours. Moreover, the different types of clouds are well detected and separated with appropriate accuracy.     

Hydrothermal synthesis,characterization and electrical investigation of poly(para-phenylenediamine)/vanadium oxide nanocomposite nanosheets

Sheet-like mesoporous poly(paraphenylenediamine)/vanadium oxide nanocomposite has been synthesized by the hydrothermal process using the vanadium oxide V₂O₅ as inorganic precursor and paraphenylendiamine as reducing and a structure-directing agent. Such techniques as X-ray diffraction (XRD), scanning electron microscopy (SEM), thermal analysis (TG-DTA), Fourier transform infrared spectroscopy (FTIR), Raman Spectroscopy, X-ray photoelectron spectroscopy (XPS) and nitrogen adsorption/desorption isotherms (BET) have been used to characterize the structure, morphology and the texture of the material. The conductivity of the material was measured by complex impedance spectroscopy which increases from 72 × 10^?5 Ω^?1 cm^?1 at 298 K to 95 × 10^?4 Ω^?1 cm^?1 at 493 K. The Arrhenius diagram is not linear, it presents a rupture situated at 407 K and the activation energies’ average values are 0.044 eV and 0.13 eV.     

Classification and Diagnosis of Lymphoma’s Histopathological Images Using Transfer Learning

Current cancer diagnosis procedure requires expert knowledge and is time-consuming, which raises the need to build an accurate diagnosis support system for lymphoma identification and classification. Many studies have shown promising results using Machine Learning and, recently, Deep Learning to detect malignancy in cancer cells. However, the diversity and complexity of the morphological structure of lymphoma make it a challenging classification problem. In literature, many attempts were made to classify up to four simple types of lymphoma. This paper presents an approach using a reliable model capable of diagnosing seven different categories of rare and aggressive lymphoma. These Lymphoma types are Classical Hodgkin Lymphoma, Nodular Lymphoma Predominant, Burkitt Lymphoma, Follicular Lymphoma, Mantle Lymphoma, Large B-Cell Lymphoma, and T-Cell Lymphoma. Our proposed approach uses Residual Neural Networks, ResNet50, with a Transfer Learning for lymphoma’s detection and classification. The model used results are validated according to the performance evaluation metrics: Accuracy, precision, recall, F-score, and kappa score for the seven multi-classes. Our algorithms are tested, and the results are validated on 323 images of 224 × 224 pixels resolution. The results are promising and show that our used model can classify and predict the correct lymphoma subtype with an accuracy of 91.6%.     

Metakaolin in the formulation of UHPC

Silica fumes have characteristics that make them exceptional in cement matrices and, in particular, in UHPC. Nevertheless, they have important disadvantages: lack of availability, cost and color. The search for substitute products thus appears important if the use of UHPC is to become more widespread in the concrete industry, e.g. in the fields of mechanical engineering (machine parts, tools, molds, etc.) and civil engineering (pipes for water or waste water conveyance for example).The substitute product used in this study was metakaolin obtained by fixed-bed calcination. It proved to be almost equivalent to silica fume in terms of mechanical properties and durability. Kaolinite, the clay from which metakaolin is produced, readily available in most countries, so the price of this ultra fine is acceptable. Moreover, its white color gives it an esthetic advantage.     

Impacts of Public Transport Policy on City Size and Welfare

Networks and Spatial Economics - This paper introduces a clear distinction between interregional and intraregional transportation cost in a mixed New Economic Geography and Urban Economics model...     

Hydrothermal synthesis and crystal structure of a new open-framework 3-D AlPO-DACH: [NH3-(C6H10)-NH3]3 [H6Al12P16 O64]

In this paper we describe the preparation of a new aluminophosphate (AlPO-DACH) [C₆ H₁₈ N₂Al₄ P_5.32O_21.32] by hydrothermal method. The structure was characterized by the single-crystal X ray diffraction. This material crystallizes in the trigonal system, space group P-3c1, a = 12.948 Å, b = 12.948 Å, c = 18.466 Å; α = 90° ; β = 90° ; γ = 120°.V = 26811(16)ų, Z = 12, R:0.086 with 808 reflections.