13,394 research outputs found

    Study of Pakistan pilot project farmer-leaders to Nepal

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    Farmer participation / Irrigation management / Farmer managed irrigation systems / Irrigated farming / Sustainable agriculture / Institution building / Pakistan

    Slave spin cluster mean field theory away from half-filling: Application to the Hubbard and the extended Hubbard Model

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    A new slave-spin representation of fermion operators has recently been proposed for the half-filled Hubbard model. We show that with the addition of a gauge variable, the formalism can be extended to finite doping. The resulting spin problem can be solved using the cluster mean-field approximation. This approximation takes short-range correlations into account by exact diagonalization on the cluster, whereas long-range correlations beyond the size of clusters are treated at the mean-field level. In the limit where the cluster has only one site and the interaction strength UU is infinite, this approach reduces to the Gutzwiller approximation. There are some qualitative differences when the size of the cluster is finite. We first compute the critical UU for the Mott transition as a function of a frustrating second-neighbor interaction on lattices relevant for various correlated systems, namely the cobaltites, the layered organic superconductors and the high-temperature superconductors. For the triangular lattice, we also study the extended Hubbard model with nearest-neighbor repulsion. In additionto a uniform metallic state, we find a (3)×(3)\sqrt(3) \times \sqrt(3) charge density wave in a broad doping regime, including commensurate ones. We find that in the large UU limit, intersite Coulomb repulsion VV strongly suppresses the single-particle weight of the metallic state.Comment: 10 pages, 11 figures, submitted to PR

    Scale-free network topology and multifractality in weighted planar stochastic lattice

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    We propose a weighted planar stochastic lattice (WPSL) formed by the random sequential partition of a plane into contiguous and non-overlapping blocks and find that it evolves following several non-trivial conservation laws, namely iNxin1yi4/n1\sum_i^N x_i^{n-1} y_i^{4/n-1} is independent of time  n\forall \ n, where xix_i and yiy_i are the length and width of the iith block. Its dual on the other hand, obtained by replacing each block with a node at its center and common border between blocks with an edge joining the two vertices, emerges as a network with a power-law degree distribution P(k)kγP(k)\sim k^{-\gamma} where γ=5.66\gamma=5.66 revealing scale-free coordination number disorder since P(k)P(k) also describes the fraction of blocks having kk neighbours. To quantify the size disorder, we show that if the iith block is populated with pixi3p_i\sim x_i^3 then its distribution in the WPSL exhibits multifractality.Comment: 7 pages, 8 figures, To appear in New Journal of Physics (NJP

    Proposed business plan for pilot farmer organizations: Extended project on Farmer Managed Irrigated Agriculture in LBOD Project Area of Sindh Province

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    Farmers' associations / Farmer managed irrigation systems / Irrigation programs / Irrigation management / Drainage / Economic aspects / Income / Operating costs / Maintenance costs / Conflict

    Coordinated Generation and Transmission Maintenance Scheduling Considering Network Constraints via GGDF and ODF

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    This paper proposes a coordinated generation and transmission maintenance scheduling by incorporating network constraints. The main advantage of the proposed approach is that maintenance is scheduled at the optimal period of the lowest possible operating cost while satisfying all the specified constraints. In this approach, sensitivity factors (GGDFs and ODFs) which are based on DC approximation are applied to calculate the line flows in normal and maintenance conditions. They are applied due to their simplicity, linearity, physical comprehension and rapidity of computation. To simulate the effect of network constraint on maintenance schedule and operating cost, several cases are studied with and without transmission limit constraints. To ensure the accuracy of these sensitivity factors, power flows on each line are compared with the one obtained from a PSSE simulator. The result shows that generators and transmission lines are scheduled at periods that satisfy the transmission capacity limit

    An Assessment of Air Quality in and around Gwagwalada Abattoir, Gwagwalada, Abuja, Fct.

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    This work attempted an assessment of air quality in and around Gwagwalada abattoir. Air samples were collected from six points around the abattoir and recorded insitu for analysis.  The following parameters were investigated; Particulate Matter (PM), Carbon monoxide (CO), Sulphur dioxide (SO2), Nitrogen dioxide (NO2), Ammonia (NH3), Chlorine (CL2) and Hydrogen cyanide. The statistical test employed was the Student t-test in verifying the hypothesis. Based on the data collected and the analysis made, it was observed that the mean values of the parameters varied from points to points and at different time of the day. Also, the mean values of the parameters were compared with the FEPA recommended limits, and it was observed that Sulphur dioxide (SO2), Nitrogen dioxide (NO2) and Particulate matter were above the FEPA recommended limit. While Carbon monoxide (CO), Hydrogen cyanide (HCN) and Ammonia (NH3) are still below the standard limit. Air Quality Index shows that Sulphur dioxide (SO2), and  Nitrogen dioxide (NO2 have very poor quality index Recommendations include; relocation of abattoir to an area far from residences, inspection of abattoir process by professionals in related fields, proper waste management systems should be made. Keywords: Air, Quality, AQI, Abattoir, pollution, and Gwagwalad

    Application of PROMETHEE method for demand side management (DSM) options ranking

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    Demand Side Management (DSM) is a method used to modify the electrical load profile of a consumer to reduce its electricity bill. There are various types of DSM options available but mostly involve costs to be incurred by consumers. Moreover, the effectiveness of a DSM option depends on various factors including investment cost, saved energy, payback period and more. Multi Criteria Decision Analysis (MCDA) is a tool that can be applied to make decision when a lot of factors to be taken into account. In DSM, Analytical Hierarchy Process (AHP) is one MCDA technique that is widely used in ranking the DSM options. However, AHP requires additive aggregation that may cause lost in detailed information. This paper presents another MDCA method; Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE) to perform the ranking of DSM options. PROMETHEE (I and II) were used in a case study and the results shows that PROMETHEE give the same result as AHP. PROMETHEE has an advantage over AHP as it does not require additive aggregation even the problem is multi-dimensional and could provide visual analysis
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