Fixed points for multi-class queues

Burke's theorem can be seen as a fixed-point result for an exponential single-server queue; when the arrival process is Poisson, the departure process has the same distribution as the arrival process. We consider extensions of this result to multi-type queues, in which different types of customer have different levels of priority. We work with a model of a queueing server which includes discrete-time and continuous-time M/M/1 queues as well as queues with exponential or geometric service batches occurring in discrete time or at points of a Poisson process. The fixed-point results are proved using interchangeability properties for queues in tandem, which have previously been established for one-type M/M/1 systems. Some of the fixed-point results have previously been derived as a consequence of the construction of stationary distributions for multi-type interacting particle systems, and we explain the links between the two frameworks. The fixed points have interesting "clustering" properties for lower-priority customers. An extreme case is an example of a Brownian queue, in which lower-priority work only occurs at a set of times of measure 0 (and corresponds to a local time process for the queue-length process of higher priority work).Comment: 25 page

Patching task-level robot controllers based on a local µ-calculus formula

We present a method for mending strategies for GR(1) specifications. Given the addition or removal of edges from the game graph describing a problem (essentially transition rules in a GR(1) specification), we apply a µ-calculus formula to a neighborhood of states to obtain a “local strategy” that navigates around the invalidated parts of an original synthesized strategy. Our method may thus avoid global resynthesis while recovering correctness with respect to the new specification. We illustrate the results both in simulation and on physical hardware for a planar robot surveillance task

Gaussian approximation for finitely extensible bead-spring chains with hydrodynamic interaction

The Gaussian Approximation, proposed originally by Ottinger [J. Chem. Phys., 90 (1) : 463-473, 1989] to account for the influence of fluctuations in hydrodynamic interactions in Rouse chains, is adapted here to derive a new mean-field approximation for the FENE spring force. This "FENE-PG" force law approximately accounts for spring-force fluctuations, which are neglected in the widely used FENE-P approximation. The Gaussian Approximation for hydrodynamic interactions is combined with the FENE-P and FENE-PG spring force approximations to obtain approximate models for finitely-extensible bead-spring chains with hydrodynamic interactions. The closed set of ODE's governing the evolution of the second-moments of the configurational probability distribution in the approximate models are used to generate predictions of rheological properties in steady and unsteady shear and uniaxial extensional flows, which are found to be in good agreement with the exact results obtained with Brownian dynamics simulations. In particular, predictions of coil-stretch hysteresis are in quantitative agreement with simulations' results. Additional simplifying diagonalization-of-normal-modes assumptions are found to lead to considerable savings in computation time, without significant loss in accuracy.Comment: 26 pages, 17 figures, 2 tables, 75 numbered equations, 1 appendix with 10 numbered equations Submitted to J. Chem. Phys. on 6 February 200

Bioadhesive polymeric platforms for transmucosal drug delivery systems – a review

Of the various routes of drug delivery, the oral route is often preferred by the patient. However, peroral administration of drugs has disadvantages such as hepatic first-pass metabolism and enzymatic degradation within the gastrointestinal tract which constitutes a hindrance to oral administration of certain classes of drugs, especially peptides and proteins. Consequently, other absorptive mucosae are often considered as potential sites for drug administration. Transmucosal routes of drug delivery (i.e., the mucosal linings of the nasal, rectal, vaginal, ocular, and oral cavity) offer distinct advantages over peroral administration for systemic drug delivery. These advantages include possible bypass of firstpass effect, avoidance of presystemic elimination within the GI tract, and, depending on the particular drug, better enzymatic flora for drug absorption. However, the mucosa surface as a site for drug delivery has limitations as well. Other than the low flux associated with mucosal delivery, a major limitation of the transmucosal route of administration is the lack of dosage form retention at the site of absorption. Consequently, bioadhesive polymers have extensively been employed in transmucosal drug delivery systems. If these materials are then incorporated into pharmaceutical formulations, drug absorption by mucosal cells may be enhanced or the drug may be released at the site for an extended period of time. This review describes various bio/mucoadhesive polymers used in transmucosal drug delivery. Starting with introduction of bioadhesion with theories and mechanism, history, different bioadhesive polymers, characteristics of desired bioadhesive polymers, this article then proceeds to cover the various sites suitable for mucoadhesive drug delivery system followed by the factors affecting bio/ mucoadhesion.Keywords: Mucosa; Tansmucosal delivery; Bioadhesion; Lectin; Polymers; Thiomer; Fimbrin

A Case History of Tehri Tunnels

Tehri Dam Project, a multipurpose river valley project, is being constructed in Garhwal, Himalaya. The project consists of a 260 m high earth and rock fill dam with a clay core, four diversion tunnels each of 11 m finish diameter, four head race tunnels each of 8.5 m finish diameter and two underground powerhouses cavities each measuring 180 m long, 49.5 m high and 21.5 m wide. The project is located near the district headquarters of Tehri in the state of Uttar Pradesh. The rock masses in the project area are fragile, tectonically active and geologically disturbed. The terrain is rugged and inaccessible and therefore precludes thorough geotechnical investigations for the design of the cavern. The diversion and the head race tunnels were therefore used to conduct geotechnical investigations with the purpose of collecting geotechnical data for the design of two caverns. Goodman Jack tests were used to estimate the modulus of deformation of the rock masses. Load cells and tape extensometers were used to monitor the support pressure and the tunnel closures. The modulus of deformation varied from 0.18 to 0.32 kg/cm.sq. X 105. Tunnel closures were about 0.3% of the tunnel size. The support pressure stabilized within three months of excavation and the measured support pressures varied between 0.16 and 1.14 kg/cm.sq. This geotechnical data indicate that the rock masses behaviour was elastic in nature and the cavern could be designed without much difficulties

Invitro Antimicrobial Activity and Phytochemical Analysis of Ficus religiosa L. and Ficus bengalensis L. against Diarrhoeal Enterotoxigenic E. coli

The barks of Ficus religiosa L. and Ficus bengalensis L., which belongs to family Moraceae, were investigated for invitro antibacterial activity and phytochemical analysis. The various solvents extract like aqueous, methanol, chloroform, petroleum ether and hexane were screened for antibacterial activity against Enterotoxigenic E. coli isolated from diarrhoeal patients. The preliminary phytochemical analysis of the methanol extracts of both the plants showed the presence of carbohydrates, flavonoids, aminoacids, steroids, saponins and tannins. The extracts were subjected for antibacterial activity against Enterotoxignic E.coli (ETEC) at 200mg/ml concentration by disc diffusion method. The results of antibacterial activity revealed that methanol extracts of both the plants barks exhibits good activity compared to chloroform and aqueous extracts. Petroleum ether and hexane extracts did not show any activity. The antibacterial activities of extracts were compared with standard antibiotics

Economic Feasibility of Vegetable Production under Polyhouse:A Case Study of Capsicum and Tomato

Polyhouse cultivation of vegetables is emerging as a specialized production technology to overcome biotic and abiotic stresses and to break the seasonal barrier to production. It also ensures round the year production of highvalue vegetables, like capsicum, especially, during off-season. Cost is the major issue in sustaining this technology. The present study examined the economic viability of production of capsicum and tomato in a naturally ventilated polyhouse of medium cost category with drip irrigation system. Data were generated by cost accounting method for estimating the feasibility of production and was analyzed by using project evaluation methods, like Pay Back Period (PBP), Benefit Cost Ratio (BCR), Net Present Value (NPV) and Internal Rate of Return (IRR). Cultivation of capsicum in a polyhouse was found to be highly feasible as reflected in higher values of NPV (Rs.3,23,145/500 m2), BCR (1.80) and IRR (53.7%) with payback period of less than two years. Breakeven price for capsicum production in a polyhouse (Rs.11.80/kg) was lesser than average wholesale price. Production of tomato in a polyhouse was found not feasible, as the breakeven price was more than the average market price and all the project appraisal parameters indicated that it was not feasible. Only at about 48% premium price over the prevailing market price or reduction of cost of polyhouse structure by 60% from Rs.400 to Rs.160 /m2, could make the tomato production viable in a poly house

Fertigation for efficient water and nutrient management in high density cashew plantation

An experiment was conducted to study the efficacy of fertigation for increasing the productivity of cashew under high density planting system (625 plants/ha). The optimal rate of fertilizer application was found as 125 g N, 31.25 g P2O5 and 31.25 g K2O/tree/ year through fertigation and 2 kg castor cake/tree through soil application (M3). The highest mean cashew nut yield of 2 t/ha/year and 1.96 t/ha/year was in treatments with 50% of recommended doses of fertilizers (RDF) through fertigation and 4 kg castor cake/ tree through soil application (M6) and the treatment with half the aforesaid dose (M3). The protein content was high in fertigation treatment with 50 % RDF and 4 kg neem cake/tree( M5) (42.6 %), followed by M6 and M3 (40.7 and 40.2 %,respectively). In soil application with drip irrigation separately, the nut yield ranged from 1.45 to 1.73 t/ha/year and protein content from 35.9 to 38.9 %, respectively. The lowest nut yield of 1.12 t/ha/year was in absolute control and the lowest protein content of 35.9 and 36.2 % were in M9 and absolute control, respectively. Fertigation increased the nut weight to 7.0 g, apple weight to 76.9 g and the shelling percentage to 30.06 compared to soil application with a nut weight of 6.8 g, apple weight of 70.8 g and a shelling percentage of 29.5 and absolute control with a nut weight of 6.7 g, apple weight of 69.4 g and a shelling percentage of 28.8, respectively. The highest net profits of Rs. 49,367/ha/year and Rs. 47,393/ha/year were also from fertigation plots M4 (RDF through fertigation) and M3. The net profit from absolute control (M13) was Rs.32,425/ha/year. In soil application treatments with drip irrigation separately (M7 to M12), the net profit ranged from Rs.32,235 to Rs.40,417/ha/year. Soil and water conservation measures with mulching conserved soil moisture and reduced the optimal irrigation requirement to 20% Cumulative Pan Evaporation (CPE). Hence, increased irrigation rates (40 and 60 % CPE) did not have any significant effect on growth of cashew plants, nut weight, shelling percentage, yield etc. The levels of minor and micronutrients of the soil and defatted cashew kernel flour in fertigation treatments were on par with soil application with separate drip irrigation and were high compared to absolute control (except Zn). Different irrigation rates did not have significant effect on kernel N, P, K, Ca and Mg content but increased irrigation (20 to 40% CPE) increased the concentration of most of the major and micro nutrients present in leaf

Acoustical-Mode-Driven Electron-Phonon Coupling in Transition-Metal Diborides

We show that the electron-phonon coupling in the transition-metal diborides NbB2 and TaB2 is dominated by the longitudinal acoustical (LA) mode, in contrast to the optical E_{2g} mode dominated coupling in MgB2. Our ab initio results, described in terms of phonon dispersion, linewidth, and partial electron-phonon coupling along Gamma to A, also show that (i) NbB2 and TaB2 have a relatively weak electron-phonon coupling, (ii) the E_{2g} linewidth is an order of magnitude larger in MgB2 than in NbB2 or TaB2, (iii) the E_{2g} frequency in NbB2 and TaB2 is considerably higher than in MgB2, and (iv) the LA frequency at A for TaB2 is almost half of that of MgB2 or NbB2.Comment: 4 pages, 4 figures, and 1 tabl

Synthesis and characterization of Ru(II) complexes with polyfunctional quinazo line-(3H)-4-ones

1066-1069A few Ru(II) complexes of the type Ru (O – N - O)2 with tridentate O – N - O donors and of the type RuCl2(O-N)2 with bidentate O - O and O – N donors have been synthesized and characterized on the basis of analytical, conductivity, thermal, magnetic, IR, electronic and PMR spectral data. The IR and PMR spectral data of the metalcomplexes indicate that the ligands like 2-methyl/phenyl-3- (2'-hydroxybenzalamino) quinazoline-(3H)-4-one (MHBQ/ PHBQ) act as uninegative tridentate, 2-methyl/phenyl- 3-(carboxymethyl) quinazoline-(3H)-4-one (MCMQ/PCMQ) as uninegative bidentate and 2-methyl/phenyl-3-(furfuralamino) quinazoline-(3H)-4-one (MFQ/PFQ), 2-methyl/phenyl-3-(acetamino) quinazoline-(3H)-4-one (MAQ/PAQ), 2-methyl/phenyl 3-(uramino) quinazoline- (3H)-4-one (MUQ/PUQ) and 2-methyl/phenyl-3- thiouramino)quinazoline-(3H)-4-one-(MTUQ/PTUQ) as neutral bidentate ligands.The electronic spectral data of the complexes indicate that the arrangement around Ru(II) is octahedral