2,197 research outputs found
Pursuit on a Graph Using Partial Information
The optimal control of a "blind" pursuer searching for an evader moving on a
road network and heading at a known speed toward a set of goal vertices is
considered. To aid the "blind" pursuer, certain roads in the network have been
instrumented with Unattended Ground Sensors (UGSs) that detect the evader's
passage. When the pursuer arrives at an instrumented node, the UGS therein
informs the pursuer if and when the evader visited the node. The pursuer's
motion is not restricted to the road network. In addition, the pursuer can
choose to wait/loiter for an arbitrary time at any UGS location/node. At time
0, the evader passes by an entry node on his way towards one of the exit nodes.
The pursuer also arrives at this entry node after some delay and is thus
informed about the presence of the intruder/evader in the network, whereupon
the chase is on - the pursuer is tasked with capturing the evader. Because the
pursuer is "blind", capture entails the pursuer and evader being collocated at
an UGS location. If this happens, the UGS is triggered and this information is
instantaneously relayed to the pursuer, thereby enabling capture. On the other
hand, if the evader reaches one of the exit nodes without being captured, he is
deemed to have escaped. We provide an algorithm that computes the maximum
initial delay at the entry node for which capture is guaranteed. The algorithm
also returns the corresponding optimal pursuit policy
Studies on the electron transfer pathway, topography of iron-sulfur centers, and site of coupling in NADH-Q oxidoreductase.
Electron transfer activities and steady state reduction levels of Fe-S centers of NADH-Q oxidoreductase were measured in mitochondria, submitochondrial particles (ETPH), and complex I after treatment with various reagents. p-Chloromercuribenzenesulfonate destroyed the signal from center N-4 (gx = 1.88) in ETPH but not in mitochondria, showing that N-4 is accessible only from the matrix side of the inner membrane. N-Bromosuccinimide also destroyed the signal from N-4 but without inhibiting rotenone-sensitive electron transfer to quinone, suggesting a branched pathway for electron transfer. Diethylpyrocarbonate caused oxidation of N-3 and N-4 in the steady state without changing N-1, suggesting N-1 is before N-3 and N-4. Difluorodinitrobenzene and dicyclohexylcarbodiimide inhibited oxidation of all Fe-S centers and tetranitromethane inhibited reduction of all Fe-S centers. Titrations of the rate of superoxide (O2-) generation in rotenone-treated submitochondrial particles were similar with the ratio [NADH]/[NAD] and that of 3-acetyl pyridine adenine nucleotide in spite of different midpoint potentials of the two couples. On reaction with inhibitors the inhibition of O2- formation was similar to that of ferricyanide reductase rather than quinone reductase. The rate of O2- formation during ATP-driven reverse electron transfer was 16% of the rate observed with NADH. The presence of NAD increased the rate to 83%. The results suggest that bound, reduced nucleotide, probably E-NAD., is the main source of O2- in NADH dehydrogenase. The effect of ATP on the reduction levels of Fe-S centers in well-coupled ETPH was measured by equilibrating with either NADH/NAD or succinate/fumarate redox couples. With NADH/NAD none of the Fe-S centers showed ATP induced changes, but with succinate/fumarate all centers showed ATP-driven reduction with or without NAD present. The effect on N-2 was smaller than that on N-1, N-3, and N-4. These observations indicate that the major coupling interaction is between N-2 and the low potential centers, N-1, N-3, and N-4. Possible schemes of coupling in this segment are discussed
An Experimental Study and Correlation for Differential Settling of Bidisperse Suspensions
Sedimentation processes have wide practical applications in mineral processing, metallurgical industries, chemical engineering, environmental technologies, water treatment, and bio-process engineering. The sedimentation process is complex in nature since
it involves the physical properties of both the solids and the fluids forming the suspensions as well as the hydrodynamic and physico/chemical phenomena that govern particle-fluid and particle-particle behaviour. The aim of this study is to measure experimentally the lower and upper interface velocities in bidisperse suspensions of solids in liquids using liquids and solids with a wide range in physical properties, and more specifically in solids concentration (glass ballotini and sand) covering concentrated and diluted suspensions. The study covers the experimental investigations on the settling rate of bidisperse suspensions in liquids using particles of equal density and at very low particle Reynolds number (Stoke’s law region) and the voidage ranges from = 0.62 to 0.95. A
correlation is developed for the representation of the experimental data for the particles of two different dimension. The experimental data have been compared with the predictions of the present proposed model as well as the models reported in the literature. An
empirical correlation for 2S1 is also proposed and its dependency on the particle diameter and the concentrations is discussed
Record of Thrips on Mango
During a trial in 2009 at Moorapoor Village, Dharmapuri district, Tamil Nadu, for control of mango hoppers and thrips using entomo-pathogens, inflorescences were seen to harbour different species of thrips. Close microscopic observation revealed presence of Frankliniella schultzei (Tryb.), Thrips palmi Karny, T. hawaiiensis (Morgan) and T. subnudula. However, Thrips palmi was the predominant species whereas, for the first time Frankliniella schultzai and Thrips subnudula (Karny, 1927) are reported here on inflorescence of mango in India
Variation in the Biomolecular Interactions of Nickel(Ii) Hydrazone Complexes Upon Tuning the Hydrazide Fragment
Three new bivalent nickel hydrazone complexes have been synthesised from the reactions of [NiCl2(PPh3)(2)] with H2L {L = dianion of the hydrazones derived from the condensation of o-hydroxynaphthaldehyde with furoic acid hydrazide (H2L1) (1)/thiophene-2-acid hydrazide (H2L2) (2)/isonicotinic acid hydrazide (H2L3) (3)} and formulated as [Ni(L-1)(PPh3)] (4), [Ni(L-2)(PPh3)] (5) and [Ni(L-3)(PPh3)] (6). Structural characterization of these compounds 4-6 were accomplished by using various physico-chemical techniques. Single crystal X-ray diffraction data of complexes 4 and 5 proved their distorted square planar geometry. In order to ascertain the potential of the above synthesised compounds towards biomolecular interactions, additional experiments involving interaction with calf thymus DNA (CT DNA) and bovine serum albumin (BSA) were carried out. All the ligands and corresponding nickel(II) chelates have been screened for their scavenging effect towards O-2(-), OH and NO radicals. The efficiency of complexes 4-6 to arrest the growth of HeLa, HepG-2 and A431 tumour cell lines has been studied along with the cell viability test against the non-cancerous NIH 3T3 cells under in vitro conditions.University Grants Commission, New Delhi under the UGC-SAP-DRSRobert A. Welch Foundation F-0003Chemistr
Influence of some Pesticides on Entomopathogenic Fungus Lecanicillium (=Verticillium) lecanii (Zimm.) ZARE & GAMS
An in vitro study was conducted to determine the interaction effect of ten pesticides tested at field recommended dose on conidial germination, vegetative growth and sporulation of Lecanicillium lecanii(ZIMM.) ZARE&GAMS. Compatibility of L. lecanii to different pesticides was found to be varied. Conidial germination was 99.3 and 85.7% in Pongamia oil and acephate, whereas, it was totally inhibited by the presence of chlorothalonil, iprodion + carbendazim, carbendazim and thiophanate methyl indicating that these pesticides were highly toxic. Dinocap recorded as moderately toxic while endosulfan, abamectin and ethion were least toxic based to the germination of conidia. So also Iprodion + carbendazim did not and carbendazim allow L. lecanii to put forth mycelium growth in their presence. Thiophanate methyl, Pongamia oil, acephate, endosulfan, ethion and chlorothalonil were observed to be innocuous pesticides registering growth of mycelium upto 2.33, 2.23, 2.23, 2.03, 2.03 and 2.00 cm dia., respectively, from 0.6 cm dia. held in the center of Petri plate on 14th day after treatment. As far as sporulation is concerned, Pongamia oil alone recorded the maximum yield of 47.2x106 conidia/ml followed by 18x106 conidia/ml, in chlorothalonil as against 20x106 conidia/ml in control, which means that the pongamia oil exhibited synergistic effect on L. lecanii, yielding more conidial spores. Thus, based on in vitro interaction study, pongamia oil alone was found to be safe to the entamopathogenic fungus L. lecanii in nature and iprodion + carbendazim and carbendazim were found to be highly toxic
A k-out-of-n reliability system with an unreliable server and phase type repairs and services: the (N, T) policy
In this paper we study a k-out-of-n reliability system in which a single unreliable server maintains n identical components. The reliability system is studied under the (N,T) policy. An idle server takes a vacation for a random amount of time T and then attends to any failed component waiting in line upon completion of the vacation. The vacationing server is recalled instantaneously upon the failure of the Nth component. The failure times of the components are assumed to follow an exponential distribution. The server is subject to failure with failure times exponentially distributed. Repair times of the component, fixing times of the server, and vacationing times of the server are assumed to be of phase type. Using matrix-analytic methods we perform steady state analysis of this model. Time spent by a failed component in service, total time in the repair facility, vacation time of the server, non-vacation time of the server, and time until failure of the system are all shown to be of phase type. Several performance measures are evaluated. Illustrative numerical examples are presented
Comparative Study of Pesticide Residue Pattern in Vegetables Grown Using IPM and Non-IPM Practices
Pesticide residue persistence pattern in three vegetable crops, viz., tomato, cabbage and cauliflower, cultivated following previously developed pesticide residue-free IPM packages, was compared with a crop cultivated under conventional or non - IPM conditions. It was observed that vegetables grown as per IPM practices were safer to consume at harvest compared to those grown as per conventional cultivation practices, with chemical control as the sole means of plant protection. Pesticide residues, if present, were mostly in trace amounts (< 0.01 ppm) in vegetables grown as per IPM practices, except the residues of methomyl and monocrotophos in cabbage, where slightly higher levels of pesticides were observed
Effect of Terminalia chebula fruit extract on lipid peroxidation and antioxidative system of testis of albino rats
The effect of aqueous extract of the Terminalia chebula was studied in male albino rats to explore its activities on testis. 1.0 ml of aqueous extract of T. chebula (500 mg/kg body weight) was given orally for 45 days. The activity of lipid peroxidation and superoxide dismutase were significantly increased but the concentration of antioxidant enzyme glutathione, and catalase were decreased in the aqueous extract administered rats rather than in control rats. Significant decrease in the activities of antioxidant enzymes, spermatogenesis and increase in the level of lipid peroxidation, indicate the severity of oxidative stress induced as a result of administration of extract of T. chebula. The aqueous extract also lead to changes in the parameters such as sperm count, motility and morphology, protein and cholesterol content of the rat testis. The long term (45 days) administration of the extract causes significant changes in the rat testis
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