Multi-electrode microbial fuel cell (MEMFC): A close analysis towards large scale system architecture

Microbial fuel cells are capable of producing electricity through the treatment of wastewater, however, the low power density poses main hurdles towards their wide application. In present work, microbial fuel cell based on multiple anodes, acting as baffle is constructed for achieving higher performance which can be scaled up for real life application. It is investigated for continuous sixty two days using distillery wastewater (WW) in three batches under ambient condition. During first batch, the WW is maintained under stagnant condition inside the anode chamber where as in the rest of the two batches WW is recirculated in the chamber. A maximum power density 427 mW m⁻², is achieved under stagnant condition which is further enhanced to 597 mW m⁻² under recirculation mode. Recirculation of WW reduces the internal resistance arising from the mass transfer by 50%. Maximum COD removal and Coulombic efficiency obtained is 43% and 23%. Biofouling on the surface of the membrane facing anode chamber is observed.     

双孔径定位开孔波纹塔板性能的研究

针对均匀开孔波纹塔板的缺陷,开发了一以孔定位开孔波纹塔板,在常温常压下,地不同开孔率的这种波纹塔板,进行了水力及传质性能试验。实验结果表明,与均匀开孔的波纹塔板相比,这种新型波纹塔板的板效率有较明显的提高。     

A Linear Discriminant for Gaussian Time Series

A simple linear discriminant is introduced for Gaussian time series with fixed deterministic component. It is demonstrated that the discriminant is 'efficient' under some general conditions. The proposed procedure is tested using some seismological data.     

磷酸一铵链条炉改换热器效果分析

对云南天安化工220kt/a磷酸一铵产品烘干工艺进行了描述,对链条炉存在的问题及改进效果进行了分析评价,得出链条炉改翅片换热器工艺可行、设备可靠、效果明显的观点。     

On uniform integrability and asymptotically risk-efficient sequential estimation

In the theory of asymptotically risk-efficient sequential estimation, one encounters uniform integrability of both positive and negative powers of stopping rules and moment convergence of randomly stopped statistics. We describe a simple approach to obtain these uniform integrability and moment convergence results, not only in the classical setting of i.i.d. observations but also for much more general stochastic sequences. We also use this approach to establish asymptotic risk efficiency of sequential estimators of means of stochastic sequences and to derive asymptotic approximations for the mean squared errors of ratio estimators.     

喷漆室空调盘管的防护与改造

根据北方天气特殊环境的特点,设计一种适合安装并且方便改造的喷漆室空调盘管加热保温及空气过滤装置,并可随时检查维护,根据外部环境温度可以适当可调整相关的设备开启状态。由原来设备进行改良,用料节约,设备易维护,可以有效地节约热能的浪费,以及提高生产效率,降低生产成本,提高产品质量。     

STEAM DRYLNG OF WOOD FUELS

ABSTRACT

The objective of this work is to investigate some of the important aspects in the design of a steam band dryer for wood fuels. For this purpose the drying of the material in a bench-scale fixed bed dryer has been studied.

Drying times and thermal efficiencies for experiments conducted under different conditions are compared. The investigated materials are soft-and hardwood chips and softwood bark.

The thermal efficiency, the part of the sensible heat which is used during one passage of the steam through the bed, increases with increasing mass load (mass of dry matter per unit area) and with decreasing steam mass flux. At a mass load of 30 kg/m the thermal efficiency is about 0.85 even at steam mass fluxes as high as 0.6 kg/m² s (1.2 m/s). The thermal efficiency proves to be almost independent of pressure and temperature of the steam.

Due to the very inhomogeneous materials the steam mass flow distribution was uneven. This causes a decreased thermal efficiency. When bark     

EFFECT OF GEOMETRIC PARAMETERS ON VENTILATION PERFORMANCE IN A DRY ROOM

ABSTRACT

The characteristics of moisture ventilation in a dry room are studied numerically. The effects of three important parameters: the positions of outlets, the aspect ratio (β) of horizontal section and the air exchange rate (N), are analyzed in terms of the scales of ventilation efficiency. Ventilation performance is evaluated by varying the aspect ratio and the air exchange rate for the four different outlet arrangements. It is found that the ventilation performance is improved when the aspect ratio in the transverse arrangement of outlets is decreased. Ventilation efficiency reaches its highest value when β is set to be 4 in the longitudinal arrangement of outlets. Regardless of the aspect ratio, the upper arrangement of the outlets shows a better ventilation performance than the lower arrangement. For all geometrical models and aspect ratios investigated in this study, the increase of the air exchange rate for improving the ventilation performance is only valid up to 60 h^?1.     

Design,optimization and controllability of an alternative process based on extractive distillation for an ethane–carbon dioxide mixture

Alternative configurations based on cryogenic extractive distillation were proposed and simulated by using Aspen Plus 7.0^® coupled to a multi-objective stochastic optimization procedure (differential evolution, DE). The evaluation of the performances of the proposed configurations was focused on the ethane–carbon dioxide azeotrope separation considering different liquefied hydrocarbon fractions as entrainers. The design alternatives were compared to the conventional chemical absorption system.The proposed sequences were simultaneously Pareto optimized by minimizing the total annual cost (TAC) and maximizing the acid gas removal. Complementary studies regarding the theoretical control properties, the thermodynamic efficiency and the greenhouse gases generation were conducted for several representative operating conditions obtained from the Pareto optimized fronts. The proposed cryogenic extractive distillation sequences realized the higher carbon dioxide removal together with the lower TAC compared to the conventional chemical absorption system.     

提高半自磨系统运转效率的分析及措施

介绍了目前国内自主设计并在使用的日处理能力最大的半自磨系统在德兴铜矿安装、调试、试运行和运行的全过程质量控制的关键点,通过系统地分析目前该矿在运行中影响半自磨系统的台效及运转率的因素,提出了应对措施,对采用类似工艺的矿山具有明显的借鉴作用。