The Balanced Unicast and Multicast Capacity Regions of Large Wireless Networks

We consider the question of determining the scaling of the $n^2$-dimensional balanced unicast and the $n 2^n$-dimensional balanced multicast capacity regions of a wireless network with $n$ nodes placed uniformly at random in a square region of area $n$ and communicating over Gaussian fading channels. We identify this scaling of both the balanced unicast and multicast capacity regions in terms of $\Theta(n)$, out of $2^n$ total possible, cuts. These cuts only depend on the geometry of the locations of the source nodes and their destination nodes and the traffic demands between them, and thus can be readily evaluated. Our results are constructive and provide optimal (in the scaling sense) communication schemes.Comment: 37 pages, 7 figures, to appear in IEEE Transactions on Information Theor

Comprehensive Study of 3-Level Stabilizer in Hybrid PV and Wind Energy Systems- A Review

When variables are bounded so that almost the whole constraints are satisfied, power system stability is typically characterized as an electric power system's ability to restore a situation of functioning equilibrium after being subjected to a physical disturbance.This paper presents a thorough investigation of three-level stabilizers in a hybrid PV Wind Energy system that is integrated with the power system. From a hybrid renewable energy system that is linked to the grid and studied with a stabilizer that uses a variety of control algorithms based on artificial intelligence algorithms developed by several researchers

Evaluation of Antioxidant Activity of Cedrela toona Roxb. Leaf Extracts

Antioxidant potency of fruits of Cedrela toona Roxb. crude methanol and its fractionated extracts (hexane, acetone and water) have been investigated, employing three different established in vitro testing systems, such as scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, reducing power assay and β-carotene method. The methanol extract of fruits of Cedrela toona Roxb. showed the best DPPH scavenging activity with the lowest EC 50 34 μg/ml, followed by the acetone (EC 50 39 μg/ml), hexane (EC 50 48 μg/ml) and water extract (EC 50 54 μg/ml). The reducing power of Cedrela toona Roxb. fruit extracts increased steadily with increasing concentrations and varied significantly with different concentrations. The methanol and acetone extracts appeared to possess the highest significant reducing activity among the extracts. The stronger reducing power in the methanol and acetone extracts was probably due to the concentration of antioxidant compounds like flavonoids and phenolics in the extract. In the β-carotene bleaching assay, the antioxidant activities of all the fruits extracts gradually increased with increasing concentration of the extracts and varied significantly with different concentrations. The water extract showed the lowest significant antioxidant activity, while the methanol extract showed the highest significant antioxidant activity. The high antioxidant activity of methanol extract tested using β-carotene model may be correlated with the high phenolic content of the methanol extract.  In conclusion, antioxidant study suggested that fruits of Cedrela toona Roxb. are potential source of natural antioxidants. However, further investigations on in vivo antioxidant activities are highly recommended. In the present study, the antioxidant potency of Cedrela toona Roxb. crude methanol and its fractionated extracts (hexane, acetone and water) have been investigated, employing three different established in vitro testing systems, such as scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, reducing power assay and β-carotene method. There is no antioxidant study reported for Cedrela toona Roxb.Thus, antioxidant activity of Cedrela toona Roxb. was evaluated as it had not been determined previously

Dry Gas Compressor Seals

SealsPg. 133-140Dry gas seals can eliminate some of the conventional problems associated with seal oil systems. Increased safety, lowered maintenance and improved reliability are key considerations for retrofitting with gas seals. Understanding the dry gas sealing technology and optimizing the seal selection for a given set of operating parameters is crucial for the successful application on rotating equipment. Control systems incorporating filtration, leakage, and pressure monitoring can provide real time diagnosis of seal performance

On Capacity Scaling in Arbitrary Wireless Networks

In recent work, Ozgur, Leveque, and Tse (2007) obtained a complete scaling characterization of throughput scaling for random extended wireless networks (i.e., $n$ nodes are placed uniformly at random in a square region of area $n$). They showed that for small path-loss exponents $\alpha\in(2,3]$ cooperative communication is order optimal, and for large path-loss exponents $\alpha > 3$ multi-hop communication is order optimal. However, their results (both the communication scheme and the proof technique) are strongly dependent on the regularity induced with high probability by the random node placement. In this paper, we consider the problem of characterizing the throughput scaling in extended wireless networks with arbitrary node placement. As a main result, we propose a more general novel cooperative communication scheme that works for arbitrarily placed nodes. For small path-loss exponents $\alpha \in (2,3]$, we show that our scheme is order optimal for all node placements, and achieves exactly the same throughput scaling as in Ozgur et al. This shows that the regularity of the node placement does not affect the scaling of the achievable rates for $\alpha\in (2,3]$. The situation is, however, markedly different for large path-loss exponents $\alpha >3$. We show that in this regime the scaling of the achievable per-node rates depends crucially on the regularity of the node placement. We then present a family of schemes that smoothly "interpolate" between multi-hop and cooperative communication, depending upon the level of regularity in the node placement. We establish order optimality of these schemes under adversarial node placement for $\alpha > 3$.Comment: 38 pages, 6 figures, to appear in IEEE Transactions on Information Theor

Chemical process analysis and opitimization using an analog computer

Call number: LD2668 .R4 1968 S482

Pharmacokinetic profile of phytoconstituent(s) isolated from medicinal plants—A comprehensive review

AbstractHerbal medicine, the backbone of traditional medicine, has played an important role in human health and welfare for a long period. Traditional therapeutic approaches of regional significance are found in Africa, South and Central America, China, India, Tibet, Indonesia, and the Pacific Islands. The considerable scientific significance and commercial potential of traditional medicines have resulted in increased international attention and global market demands for herbal medicines, especially Chinese herbal medicines. Herbal medicines currently are the primary form of health care for the poor in the developing countries, and also are widely used as a supplement or substitute for conventional drugs in developed countries. These traditional medicines have a pivotal role in the treatment of various ailments and more than 50% of drugs used in Western pharmacopoeia are isolated from herbs or derived from modifications of chemicals found in plants. Herbal medicines usually contain a complex mixture of various bioactive molecules, which make its standardization complicated, and there is little information about all compounds responsible for pharmacological activity. Several research papers have been published that claim pharmacological activity of herbal medicines but few are discussing the role of the exact phytoconstituent. Understanding the pharmacokinetic profile of such phytoconstituents is essential. Although there are research papers that deal with pharmacokinetic properties of phytoconstituents, there are a number of phytoconstituents yet to be explored for their kinetic properties. This article reviews the pharmacokinetic profile of 50 different therapeutically effective traditional medicinal plants from the year 2003 onward

Acting as Expected:Global Leadership Preferences and the Pursuit of an Integrated Supply Chain

While research has extensively explored the potential benefits companies gain with integrated supply chains, the topic of why some companies are better at pursuing supply chain integration (SCI) is relatively under‐examined. We take the perspective that SCI is associated with preferred forms of leadership using leadership preference derived from path–goal logic. By combining global data sources, we examine the relationships among leadership style preferences, internal integration (i.e., between sales and purchasing) programs, and external integration (i.e., supplier side) programs. Our country‐level results challenge the assumption that the choice to pursue internal and external integration has similar origins. Specifically, while collaborative‐style leadership preferences relate to internal integration programs, societies preferring individualistic‐style leaders will be predisposed toward external integration programs. Our study’s contribution is in the novel use of theories on leadership to explain variations in approaches toward supply chain integration