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Fenton's Reagent is a strong oxidant for 2,4,6 Trichlorophenol (TCP) in aqueous phase. This reaction can be effectively utilized to treat an industrial wastewater containing TCP, and reduce the toxicity of the discharge. This paper reports the effects of the amounts of the oxidant (hydrogen peroxide) and the catalyst (ferrous ions), relative to TCP, on the rates and extents of reaction. The progress of each reaction has been monitored in terms of TCP removal, chloride ions release from the organic structure, change in pH, and the reductions in COD and TOC. This information is important in order to maximize the level of treatment with minimum application of chemicals. A set of optimum molar ratios of oxidant to substrate, and catalyst to oxidant were determined. 相似文献
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We consider stochastic systems defined over irregular, multidimensional, integer spaces that have a product form steady state distribution. Examples of such systems include closed and BCMP type of queuing networks, polymerization and genetic models. In these models the system state is a vector of integers, n=[n
1,...,n
M
] and the steady state solution has product form of the type (n)=
i=1
M
f
i
(n
i
). To obtain useful statistics from such product form solutions, (n) has to be summed over some subset of the space over which it is defined. We consider situations when these subsets are defined by a set of equalities and inequalities with integer coefficients, as is most often the case and provide integral expressions to obtain these sums. Typically, a brute force technique to obtain the sum is computationally very expensive. Algorithmic solutions are available for only specific forms of f
i
(n
i
) and shapes of the state space. In this paper we derive general integral expressions for arbitrary state spaces and arbitrary f
i
(n
i
). The expressions that we derive here become especially useful if the generating functions f
i
(n
i
) can be expressed as a ratio of polynomials in which case, exact closed form expressions can be obtained for the sums. We demonstrate the wide applicability of the integral expressions that we derive here through three examples in which we model finite highway cellular systems, copy networks in multicast packet switches and a BCMP queuing network modeling a multiuser computer system. 相似文献
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A Wireless MAC Protocol with Collision Detection 总被引:1,自引:0,他引:1
Jun Peng Liang Cheng Biplab Sikdar 《Mobile Computing, IEEE Transactions on》2007,6(12):1357-1369
The most popular strategies for dealing with packet collisions at the medium access control (MAC) layer in distributed wireless networks use a combination of carrier sensing and collision avoidance. When the collision avoidance strategy fails, such schemes cannot detect collisions and corrupted data frames are still transmitted in their entirety, thereby wasting the channel bandwidth and significantly reducing the network throughput. To address this problem, this paper proposes a new wireless MAC protocol capable of collision detection. The basic idea of the proposed protocol is the use of pulses in an out-of-band control channel for exploring channel condition and medium reservation and achieving both collision avoidance and collision detection. The performance of the proposed MAC protocol has been investigated using extensive analysis and simulations. Our results show that, as compared with existing MAC protocols, the proposed protocol has significant performance gains in terms of node throughput. Additionally, the proposed protocol is fully distributed and requires no time synchronization among nodes. 相似文献
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Effect of Alumina Reactivity on the Densification and Properties of Al2O3–Cr2O3 Refractories
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Mithun Nath Vakiti Pradeep Reddy Somnath Sinhamahapatra Kausik Dana Arup Ghosh Himansu Sekhar Tripathi 《International Journal of Applied Ceramic Technology》2015,12(3):608-613
Alumina‐chrome (Al2O3–Cr2O3) refractories with Al2O3:Cr2O3 molar ratio 1:1 were synthesized in the temperature range of 1400–1700°C by conventional solid–oxide reaction route. The effect of different aluminas (viz., hydrated and calcined) on the densification, microstructure, and properties of Al2O3–Cr2O3 refractories was investigated without changing the Cr2O3 source. The starting materials were analyzed to determine the chemical composition, mineralogy, density, surface area, and particle size. Sintered materials were characterized in terms of densification, phase assemblage, and mechanical strength at room temperature and at higher temperatures. Microstructural evolution at different sintering temperature was correlated with sintering characteristics. It can be concluded that the Al2O3–Cr2O3 refractories prepared with hydrated alumina as Al2O3 source show better densification and hot mechanical strength than corresponding calcined variety. 相似文献
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Silicon - The ability of carbon- and silicon-based nanotubes, including pure carbon, silicon carbide, and Ge-doped silicon carbide nanotubes (CNT, SiCNT, SiCGeNT, respectively), for sensing highly... 相似文献