Informatics Publishing Limited

Satyabir Singh ¹, Man Singh ²

Affiliations
1 Assoc. Prof. R.K.S.D (P.G )College, Kaithal-136027(Haryana)
2 Prof. of Mathematics (Retd.), Deptt. of Mathematics & Statistics, CCS, Haryana Agricultural University, Hisar – 125004 (Haryana), IN

Abstract

O'Brien (1954), Jackson (1954) and Hunt (1955) studied the problems of serial queues in the steady state with Poisson assumptions. In these studies, it is assumed that the unit must go through each service channel without leaving the system. Barrer (1955) obtained the steady-state solution of a single channel queuing model having Poisson input, exponential holding time, random selection where impatient customers leave the service facility after a wait of certain time. Finch (1959) studied simple queues with customers at random for service at a number of service stations in series where the arrival from outside was considered at the initial stage. Feedback is permitted either from the terminal server or from each server of the series to the queue waiting for service at that stage by imposing an upper limit on the number of customers in the system at any time. Singh (1984) studied the problem of serial queues introducing the concept of reneging. Singh and Umed (1994) worked on the network of queuing processes with impatient customers. Punam, Singh and Ashok (2011) found the steady-state solution of serial queuing processes where feedback is not permitted.

Keywords

Steady-state, Difference-differential, Waiting Space, Serial, Nonserial, Random Selection, Poisson Arrivals, Exponential Service, Feedback, Balking, Reneging, Marginal Probabilities And Mean Queue Length

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Man Singh ¹

Affiliations
1 Chemistry Research Laboratory, Deshbandhu College, University of Delhi, New Delhi, IN

Abstract

Viscosities (η, ± 0.06 × 10^-5 N s m^-2), surface tension (γ ± 0.05 × 10^-3 N m^-1) and densities (ρ ± 1 × 10^-2 kg m^-3) for 0.005 to 0.25 mol kg^-1 1-methylurea (MU), 1, 3-dimethylurea (DMU) and 1, 1, 3, 3-tetramethylurea (TMU) as N, N' methylureas at interval of 0.005 mol kg^-1 were measured at pH 7.99 to 7.01 and 293.15, 298.15 and 303.15 K temperatures. Intrinsic viscosities [η] and limiting surface tension γ⁰ are obtained from regression with molality, m. Contributions of -CH₃ (methyl) groups are derived from differences in [η] and γ⁰ values individually between their subsequent ureas. The [η] and γ⁰ values infer weakening of hydrophilic interactions with -CH₃ and strengthening of hydrophobic, and TMU shows structure making effect. As compared to measurements of viscosities and surface tension individually with viscometer and stalagmometer, the Survismeter minimizes 2/3rd of materials, human efforts and infrastructure with better accuracies. It prevents evaporation of liquids during surface tension measurements.

Keywords

Survismeter, Surface Tension, Viscosity, Intrinsic Viscosities, Tetramethylurea, Structure Breaking/Making Interactions.

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N. S. Abeysingha ¹, Man Singh ¹, V. K. Sehgal ², Manoj Khanna ¹, Himanshu Pathak ³, Priyantha Jayakody ⁴, Raghavan Srinivasan ⁵

Affiliations
1 Water Technology Center, Indian Agricultural Research Institute, New Delhi 110 012, IN
2 Division of Agricultural Physics, Indian Agricultural Research Institute, New Delhi 110 012, IN
3 Division of Environmental Science, Indian Agricultural Research Institute, New Delhi 110 012, IN
4 Allegro Recruitment Consulting, Melbourne, Victoria, AU
5 Spatial Sciences Lab, Department of Ecosystem Science and Management, Texas A&M University, College Station, Texas, US

Abstract

Soil and Water Assessment Tool (SWAT) was used to assess the water yield and evapotranspiration for the Gomti River basin, India for over a period of 25 years (1985-2010). Streamflow calibration and validation of results showed satisfactory performance (NSE: 0.68-0.51; RSR: 0.56-0.68; |PBIAS|: 2.5-24.3) of the model. The water yield was higher in the midstream sub-basins compared to upstream and downstream sub-basins whereas evapotranspiration per unit area decreased from upstream to the downstream. Both evapotranspiration and water yield at upstream and midstream sub-basins increased from 1985 to 2010, whereas water yield at downstream decreased from 1985 to 2010. We found that the spatial and temporal patterns of evapotranspiration and water yield were closely linked to climatic conditions and irrigation in the basin. The long-term trends in water yield point to a drying tendency of downstream sub-basin covering the districts of Jaunpur and Varanasi.

Keywords

Irrigation, Rainfall, Modelling, Streamflow, Water Use.

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