Search

Unidirectional growth, a novel and promising approach, is a key method for synthesizing large-scale single crystals of ultra-thin materials. In this study, we present a unique and convenient method for the growth of molybdenum dioxide (MoO 2) nanoflakes on a c-sapphire substrate, achieving uniform orientation. Specifically, the MoO 2 (100) and MoO 2 < 02 1 ¯ > are aligned parallel to sapphire(0001) and sapphire<1 2 ¯ 10>, respectively. A crucial observation in our study is the presence of a buffer layer between the as-grown MoO 2 and c-sapphire. This buffer layer is essential in overcoming the limitation of lattice mismatch, thereby facilitating the unidirectional growth of MoO 2. The introduction of reductants, such as H 2 and sulfur vapor, is critical for the formation of this buffer layer. Electrical measurements indicate that the electrical conductivity of the as-grown MoO 2 nanoflake is approximately 3.91 × 106 S/m at 300 K, which is comparable to other metallic nanomaterials. In addition, magnetotransport measurements reveal that the as-grown MoO 2 nanoflakes exhibit a temperature-dependent linear magnetoresistance (MR) under magnetic fields. These findings not only demonstrate a method for the unidirectional growth of MoO 2 on the c-sapphire substrate but also have significant implications for the application of MoO 2 in transparent electrodes and the fabrication of integrated devices based on MoO 2. • MoO 2 nanoflakes with uniform orientation are synthesized on c-sapphire substrate through a convenient CVD method. • A buffer layer is observed between MoO 2 nanoflakes and substrate, resulting the unidirectional growth of MoO 2 nanoflakes. • The MoO 2 nanoflakes exhibit high conductivity and temperature-dependent linear magnetoresistance under magnetic fields. [ABSTRACT FROM AUTHOR]

Clathrate hydrates are ice-like, crystalline solids, composed of a three-dimensional network of hydrogen bonded water molecules that confines gas molecules in well-defined cavities that can store gases as a solid solution. Ideally, hydrogen hydrates can store hydrogen with a maximum theoretical capacity of about 5.4 wt%. However, the pressures necessary for the formation of such a hydrogen hydrate are 180–220 MPa and therefore too high for large-scale plants and industrial use. Thus, since the early 1990s, there have been numerous studies to optimize pressure and temperature conditions for hydrogen formation and storage and to develop a proper reactor type via optimisation of the heat and mass transfer to maximise hydrate storage capacity in the resulting hydrate phase. So far, the construction of the reactor has been developed for small, sub-litre scale; and indeed, many attempts were reported for pilot-scale reactor design, on the multiple-litre scale and larger. The purpose of this review article is to compile and summarise this knowledge in a single article and to highlight hydrogen-storage prospects and future challenges. [ABSTRACT FROM AUTHOR]

Javier de Mesones-Cabello was an influential and active planner of the 1960s and 1970s in Spain, who passed away in December, 2016. His professional career as a self-taught urban planner was extensively linked to his academic and institutional activities. These connections supported the establishment of relationships with prestigious professionals working in urban planning practice. In planning the 1969 masterplan for the city of Valladolid, in Spain, de Mesones-Cabello made several intellectual references to the Greek urban planner Doxiadis. This masterplan covers a relatively unknown example of directional city growth in a European context. My findings elucidate the extent to which de Mesones-Cabello was influenced by Doxiadis, and the circumstances in which these ideas have continued to dominate thinking about Valladolid's urban development. [ABSTRACT FROM AUTHOR]

• Europium-doped Copper Sulphate Pentahydrate crystal was successfully grown using the Unidirectional growth method, achieving a length of 108 mm. • X-ray Diffraction analysis confirmed that the crystal belonged to the P1 space group, and lattice parameters were calculated. • Scanning electron microscope images and EDAX analysis confirmed the presence of Europium in the crystal. • Photoluminescence studies demonstrated an emission peak at 640 nm, corresponding to 5D 0 to 7F J (J = 2,3) transition levels of Europium ions in the orange-red region. • Antimicrobial studies revealed significant inhibition zones for various bacterial and fungal cultures, indicating the crystal's potential antimicrobial activity. A Europium-doped Copper Sulphate Pentahydrate crystal was grown using Unidirectional growth method, resulting in a crystal that was 108 mm long. Various characterization methods were employed to investigate its growth, optical, structural, and antimicrobial properties. X-ray Diffraction analysis showed that the crystal belonged to the P1 space group and calculated its corresponding lattice parameters. The band gap of the grown crystal was determined by analysing its response to UV excitation. Fourier transform infrared spectroscopy identified the presence of OH and sulfoxide bond. Surface images of the crystal were taken using the Scanning electron microscope, and EDAX reports confirmed the presence of Europium in the grown crystal. Photoluminescence studies showed the emission peak at 640 nm, and 5D 0 to 7F J (J = 2,3) transition levels were observed in the emission spectrum corresponding to europium ions in the orange-red region using 320 nm of excitation wavelength. Antimicrobial studies were conducted on Eu doped CuSO 4 ·5H 2 O crystals using two gram-positive, two gram-negative bacteria, and two fungal cultures. The zone of inhibition was measured and found to be 12,12,13.5,14 mm and 16,17 mm for Staphylococcus aureus, Enterococcus Faecalis, Escherichia coli, Klebsiella pneumoniae, and Candida, Aspergillus, respectively. These findings indicate that Eu doped CuSO 4 ·5H 2 O is a fast-growing crystal that exhibits good quality optical and antimicrobial activity. [ABSTRACT FROM AUTHOR]