Distributed pressure matching strategy using diffusion adaptation

Personal sound zone (PSZ) systems, which aim to create listening (bright) and silent (dark) zones in neighboring regions of space, are often based on time-varying acoustics. Conventional adaptive-based methods for handling PSZ tasks suffer from the collection and processing of acoustic transfer functions~(ATFs) between all the matching microphones and all the loudspeakers in a centralized manner, resulting in high calculation complexity and costly accuracy requirements. This paper presents a distributed pressure-matching (PM) method relying on diffusion adaptation (DPM-D) to spread the computational load amongst nodes in order to overcome these issues. The global PM problem is defined as a sum of local costs, and the diffusion adaption approach is then used to create a distributed solution that just needs local information exchanges. Simulations over multi-frequency bins and a computational complexity analysis are conducted to evaluate the properties of the algorithm and to compare it with centralized counterparts

Chandra X-ray Measurement of Gas-phase Heavy Element Abundances in the Central Parsec of the Galaxy

Elemental abundances are key to our understanding of star formation and evolution in the Galactic center. Previous work on this topic has been based on infrared (IR) observations, but X-ray observations have the potential of constraining the abundance of heavy elements, mainly through their K-shell emission lines. Using 5.7 Ms Chandra observations, we provide the first abundance measurement of Si, S, Ar, Ca and Fe, in four prominent diffuse X-ray features located in the central parsec of the Galaxy, which are the manifestation of shock-heated hot gas. A two-temperature, non-equilibrium ionization spectral model is employed to derive the abundances of these five elements. In this procedure, a degeneracy is introduced due to uncertainties in the composition of light elements, in particular, H, C and N. Assuming that the hot gas is H-depleted but C- and N-enriched, as would be expected for a standard scenario in which the hot gas is dominated by Wolf-Rayet star winds, the spectral fit finds a generally subsolar abundance for the heavy elements. If, instead, the light elements had a solar-like abundance, the heavy elements have a fitted abundance of $\sim$1--2 solar. The $\alpha$/Fe abundance ratio, on the other hand, is mostly supersolar and insensitive to the exact composition of the light elements. These results are robust against potential biases due to either a moderate spectral S/N or the presence of non-thermal components. Implications of the measured abundances for the Galactic center environment are addressed.Comment: 13 pages, 6 figures, Accepted for publication in MNRA

The Production and Characteristics Test of Synthetic Rice Made of Maize Flour

Synthetic rice made of maize flour has a great opportunity to be developed as a staple food. Peopleused to consume synthetic rice, but only limited studies reported about the preferred characteristic of synthetic rice. The purpose of this study is 1) to produce and examine the characteristic of synthetic rice including moisture content, particle size, storage time and steam duration, and 2) toobtaine the preferred sensory level of synthetic rice based on aroma, texture, flavor and color.The procedure was startedbymakingthe maize flourto produce synthetic rice using a granulator machine. The granules was then steamed and dried under the sun light. Seventype of synthetic rice was used in this research, namely pure maize rice (100% maize flour), three mixed synthetic rice of maize flour and wheat flour, and three mixed synthetic riceofmaize flour and tapioca flour withthree different ratio 95:5, 85:75, and 75:25.). The results showed that the water content of synthetic rice was measured between 10.37 to 13.79%. While the steaming timewas reached around 46 to 68 minutes. The rice wasable to be stored about 24-26 hour. The organoleptic testsshowed that the most favorite synthetic rice was a mixture maize rice of 95% maize flour and 5% of tapioca flour for all level preference of the sensory test

Historical development and novel concepts on electrolytes for aqueous rechargeable batteries

In battery systems, aqueous electrolytes are superior in ionic conductivity, interfacial wettability, safety and environmentally benign compared to organic liquids, polymers, inorganic solid-state and ionic liquid electrolytes

Electrooxidation of ammonia on A-site deficient perovskite oxide La0.9Ni0.6Cu0.35Fe0.05O3-δ for wastewater treatment

Wastewater can contain high amounts of ammonia which can pose as a great safety threat if released into natural waters. The electrochemical oxidation of ammonia offers a viable strategy to remove high concentrations and provides an attractive method for wastewater treatment. However, finding a highly efficient and low-cost catalyst is imperative for overcoming the sluggish nature of ammonia oxidation reaction. Herein, a modified A- and B-site perovskite is proposed as a catalyst for the oxidation of ammonia, making it suitable as an anode in an ammonia electrolyser. A series of La1-yNi0.6Cu0.4-xFexO3-δ (x = 0, 0.05 and 0.10; y = 0, 0.05 and 0.10) perovskite materials were synthesised by a conventional sol–gel method. Amongst those tested oxides, La0.9Ni0.6Cu0.35Fe0.05O3-δ was found to have superior activity towards the electrooxidation of ammonia due to an optimised amount of Fe doping and the presence of oxygen vacancies introduced by an A-site deficiency. Subsequently, La0.9Ni0.6Cu0.35Fe0.05O3-δ was employed as an anode in an ammonia electrolyser where the ammonia removal efficiency reached 95.4 % in simulated wastewater after 80 hr and a substantial reduction in real wastewater was also observed. These results demonstrate that the A-site deficient perovskite materials are a viable electrode for the removal of ammonia in a practical energy setting and paves way for future applications

Assessing the value of commercial building low-carbon retrofit in Edinburgh City in Scotland

The purpose of current work is to assess the economics in the retrofit of non-domestic buildings in the UK, and recommend policy mechanisms to bridge the gap. This paper gives an overview of evaluation methodologies, incl. the technology assessment mechanism, financial cash flow valuation method, and the novel real option approach for assessing the value of new buildings designed in a low carbon retrofit readiness status. Detailed analysis of potential benefits from retrofitting existing commercial buildings in Edinburgh City is carried out. Resultshows substantial financial value in retrofitting a buildingover a lifetime through assessing the option value.The economic viability of retrofitting a commercialbuilding to low carbon design in Edinburgh is proven to be very high. Thus, new buildings are proposed to design in a ‘Low Carbon Building Retrofit Readiness’ status (‘LCB Readiness’) and it would be beneficial to develop a standard orbest practice for low carbon design for commercialbuildings.link_to_OA_fulltex