42 research outputs found
Monitoring Structural Transformations in Crystals. Part 15. Structural Changes in Crystals Caused by UV Radiation Despite the Lack of a Photochemical Reaction
Experimental and Theoretical Charge Density Analysis of Polymorphic Structures: The Case of Coumarin 314 Dye
Interesting reaction of 2,2 '-binaphthol with 1,2-dibromoethane: Synthesis of a novel spirodienone
2,2'-Binaphthol 1 reacts with 1,2 dibromoethane in the presence of potassium carbonate to give rise to a novel spirodienone system 3 and its structure has been confirmed by X-ray analysis
Design and Simulation of a Vapour Compression Refrigeration System Using Phase Change Material
The paper details the design and simulation of a solar powered vapour compression refrigeration system. The effect of a phase change material, in this case ice, on a vapour compression refrigeration system powered by solar panels is discussed. The battery and solar panels were sized to allow the system to function as an autonomous unit for a minimum of 12 hours. It was concluded that the presence of a phase change material in the refrigeration system caused a considerable increase in both the on and off time of the compressor. The ratio by which the on time increased was greater than the ratio by which the off time was increased. There was a 219% increase in the on time, a 139% increase in the compressor off time and a 3.5% increase in compressor work accompanied by a 5.5% reduction in COP. Thus, under conditions where there is enough load in the system to cause the initial on and off times of the compressor to be comparable, the presence of a phase change material may result in a greater on period than an off period for the compressor
A Novel ASIC Implementation of Two-Dimensional Image Compression Using Improved B.G. Lee Algorithm
A 2D Discrete Cosine Transform and Inverse Discrete Cosine Transform using the B.G. Lee algorithm, incorporating a signed error-tolerant adder for additions, and a signed low-power fixed-point multiplier to perform multiplications are proposed and designed in this research. A novel Application Specific Integrated Circuit hardware implementation is used for the 2D DCT/IDCT computation of each 8 × 8 image block by optimizing the input data using the concepts of pipelining. An enhanced speed in processing and optimized arithmetic computations was observed due to the eight-stage pipeline architecture. The 2D DCT/IDCT of each 8 × 8 image segment can be quickly processed in 34 clock cycles with a substantially reduced level of circuit complexity. The B.G. Lee algorithm has been implemented using signed error-tolerant adders, signed fixed-point multipliers, and shifters, reducing computational complexity, power, and area. The Cadence Genus tool synthesized the proposed architecture with gpdk-90 nm and gpdk-45 nm technology libraries. The proposed method showed a significant reduction of 31.01%, 12.17%, and 21.11% in power, area, and PDP in comparison to the existing image compression architectures. An improved PSNR of the reconstructed image was also achieved compared to existing designs
Design and Simulation of a Vapour Compression Refrigeration System Using Phase Change Material
The paper details the design and simulation of a solar powered vapour compression refrigeration system. The effect of a phase change material, in this case ice, on a vapour compression refrigeration system powered by solar panels is discussed. The battery and solar panels were sized to allow the system to function as an autonomous unit for a minimum of 12 hours. It was concluded that the presence of a phase change material in the refrigeration system caused a considerable increase in both the on and off time of the compressor. The ratio by which the on time increased was greater than the ratio by which the off time was increased. There was a 219% increase in the on time, a 139% increase in the compressor off time and a 3.5% increase in compressor work accompanied by a 5.5% reduction in COP. Thus, under conditions where there is enough load in the system to cause the initial on and off times of the compressor to be comparable, the presence of a phase change material may result in a greater on period than an off period for the compressor
2-methylperimidinium acetate monohydrate
The title compound, C12H11N2+.C2H3O2-.H2O, is a hydrated salt of 2-methylperimidinium acetate. The 2-methylperimidinium cations are protonated al the N atoms. In the acetate anions, the C-O bond distances are 1.238(3) and 1.265(3) Angstrom. A hydrogen-bonding network allows the self assembly of the ionic counterparts, together with the water of hydration, along the c axis
First example of functionalization of activated quinolines by indoles using CeCl<SUB>3</SUB>·7H<SUB>2</SUB>O
Indoles undergo smooth addition to activated quinolines and isoquinolines in the presence of
CeCl3·7H2O under extremely mild conditions to provide
2-(1H-3indolyl)-1,2-dihydroquinolines and isoquinolines in excellent yields with high selectivity. It is entirely a new
protocol to functionalize both indoles and quinolines in a single-step operation
Recent Developments in Photoalignment Technology:Alignment Properties of a Thiophene Based Bis-hydrazone Derivative
Liquid crystal photoalignment using commercially
available azo dye CD-1 is reviewed. Proposed dye shows
excellent alignment properties which is highly promisable for future applications. This photoalignment is based on rotational diffusion in a potential created by the light field as well as intermolecular forces. It will be shown that this photo-aligning dye shows strong anchoring energy of the LC cell and also having high thermal and ultraviolet (UV) stability. The application of liquid crystal displays using this dye is also discussed