The Experts below are selected from a list of 210 Experts worldwide ranked by ideXlab platform

C. Petalas - One of the best experts on this subject based on the ideXlab platform.

  • Use of GIS in siting stabilization pond facilities for domestic wastewater treatment.
    Journal of environmental management, 2006
    Co-Authors: Alexandra Gemitzi, Vassilios A. Tsihrintzis, Odysseas Christou, C. Petalas
    Abstract:

    Geographic information systems (GIS) use is presented in the problem of siting Areas for construction of natural systems such as stabilization ponds (SPs) for domestic wastewater treatment. For this purpose, several variables, such as topography, land use, type of geological formation, distance to major rivers or lakes, distance to existing cities and villages, existence of environmentally protected Areas, mean minimum monthly temperatures and Required wastewater effluent characteristics were analyzed with the GIS, in order to accept or reject a particular Area within a region. The method is applied in the region of Thrace (Northeast Greece) at the municipal level. The Required Area for SP systems was calculated in each of the 36 municipalities of Thrace (including two islands, Thassos and Samothraki) as a function of the population of each municipality, temperature and local wastewater effluent discharge criteria. Based on the GIS analysis, suitable locations were identified in each municipality first, and then the total Required Surface Area of these systems was compared to the available Surface Area of each municipality, in order to decide whether SP systems could be a viable solution to the wastewater management problem in the particular region. In that way the present methodology offers a fast and simple method to check the suitability of new Areas for construction of such systems.

Alexandra Gemitzi - One of the best experts on this subject based on the ideXlab platform.

  • Use of GIS in siting stabilization pond facilities for domestic wastewater treatment.
    Journal of environmental management, 2006
    Co-Authors: Alexandra Gemitzi, Vassilios A. Tsihrintzis, Odysseas Christou, C. Petalas
    Abstract:

    Geographic information systems (GIS) use is presented in the problem of siting Areas for construction of natural systems such as stabilization ponds (SPs) for domestic wastewater treatment. For this purpose, several variables, such as topography, land use, type of geological formation, distance to major rivers or lakes, distance to existing cities and villages, existence of environmentally protected Areas, mean minimum monthly temperatures and Required wastewater effluent characteristics were analyzed with the GIS, in order to accept or reject a particular Area within a region. The method is applied in the region of Thrace (Northeast Greece) at the municipal level. The Required Area for SP systems was calculated in each of the 36 municipalities of Thrace (including two islands, Thassos and Samothraki) as a function of the population of each municipality, temperature and local wastewater effluent discharge criteria. Based on the GIS analysis, suitable locations were identified in each municipality first, and then the total Required Surface Area of these systems was compared to the available Surface Area of each municipality, in order to decide whether SP systems could be a viable solution to the wastewater management problem in the particular region. In that way the present methodology offers a fast and simple method to check the suitability of new Areas for construction of such systems.

Fred Possmayer - One of the best experts on this subject based on the ideXlab platform.

  • Interactions of pulmonary surfactant protein SP-A with monolayers of dipalmitoylphosphatidylcholine and cholesterol: roles of SP-A domains.
    Journal of lipid research, 1999
    Co-Authors: Francis X. Mccormack, Dennis R. Voelker, Fred Possmayer
    Abstract:

    Pulmonary surfactant protein A (SP-A) is an oligo- meric glycoprotein that binds dipalmitoylphosphatidylcho- line (DPPC). Interactions of rat SP-A and recombinant SP- As with pure and binary monolayers of DPPC and choles- terol were studied using a rhomboid Surface balance at 37 8 C. A marked inflection at equilibrium Surface tension (23 mN/m) in Surface tension-Area isotherm of a pure DPPC film was abolished by rat SP-A. The inflection was decreased and shifted to 18 mN/m with wild-type recom- binant SP-A (SP-A hyp ). Both rat SP-A and SP-A hyp de- creased Surface Area reduction Required for pure DPPC films to reach near zero Surface tension from 30 to 25%. SP-A hyp,E195Q,R197D , mutated in carbohydrate recognition do- main (CRD) known to be essential for SP-A-vesicle interac- tions, conveyed a detrimental effect on DPPC Surface activ- ity. SP-A D G8-P80 , with deletion of collagen-like domain, had little effect. Both SP-A hyp,C6S (Ser substitution for Cys 6 ) and SP-A hyp, D N1-A7 (N-terminal segment deletion) which appear mainly as monomers on non-reducing SDS-PAGE analysis, increased Required Surface Area reduction for minimal sur- face tension. All SP-As reduced collapse Surface tension of a pure cholesterol film from 27 to 23 mN/m in the presence of Ca 2 1 . When mixed films were formed by successive spreading of DPPC/SP-A/cholesterol, rat SP-A, SP-A hyp , or SP-A D G8-P80 blocked the interaction of cholesterol with DPPC; SP-A hyp,E195Q,R197D could not impede the interaction; SP-A hyp,C6S or SP-A hyp, D N1-A7 only partially blocked the inter- action, and cholesterol appeared to stabilize SP-A hyp,C6S - DPPC association. These results demonstrate the impor- tance of CRD and N-terminal dependent oligomerization in SP-A-phospholipid associations. The findings further indi- cate that SP-A-cholesterol interactions differ from SP-A- DPPC interactions and may be nonspecific. —Yu, S-H., F. X. McCormack, D. R. Voelker, and F. Possmayer. Interactions of pulmonary surfactant protein SP-A with monolayers of dipalmitoylphosphatidylcholine and cholesterol: roles of SP-A domains. J. Lipid Res. 1999. 40: 920-929.

Carla Maria Vasconcellos Fróes - One of the best experts on this subject based on the ideXlab platform.

  • Determination of the Required Surface Area for activated sludge final clarifiers based on a unified database
    Water Research, 1999
    Co-Authors: Marcos Von Sperling, Carla Maria Vasconcellos Fróes
    Abstract:

    Abstract The paper presents a methodology for the calculation of the Surface Area of activated sludge secondary sedimentation tanks, based on a simplification of the solids flux theory. The proposed methodology has the advantage of being based on the integration of settling data from tens of full-scale plants presented by several authors in different countries. The equations derived are separated by settleability ranges (very good, good, fair, poor, very poor), which allow the easy decision by the designer or operator with respect to the equation to be adopted. The values of the hydraulic and solids loading rates compare well with those presented in frequently used design manuals, but have the advantage of allowing continuous solutions for any MLSS concentration and of taking into account the influence of the sludge return ratio, usually not incorporated in the usual methods. The paper develops two general equations of simple use for the calculation of the maximum allowable value of Q/A, therefore allowing simultaneous compliance with the clarification and thickening requirements of the clarifier. The work includes formulae, charts and tables for the determination of the hydraulic and solids loading rates according to the proposed methodology.

Odysseas Christou - One of the best experts on this subject based on the ideXlab platform.

  • Use of GIS in siting stabilization pond facilities for domestic wastewater treatment.
    Journal of environmental management, 2006
    Co-Authors: Alexandra Gemitzi, Vassilios A. Tsihrintzis, Odysseas Christou, C. Petalas
    Abstract:

    Geographic information systems (GIS) use is presented in the problem of siting Areas for construction of natural systems such as stabilization ponds (SPs) for domestic wastewater treatment. For this purpose, several variables, such as topography, land use, type of geological formation, distance to major rivers or lakes, distance to existing cities and villages, existence of environmentally protected Areas, mean minimum monthly temperatures and Required wastewater effluent characteristics were analyzed with the GIS, in order to accept or reject a particular Area within a region. The method is applied in the region of Thrace (Northeast Greece) at the municipal level. The Required Area for SP systems was calculated in each of the 36 municipalities of Thrace (including two islands, Thassos and Samothraki) as a function of the population of each municipality, temperature and local wastewater effluent discharge criteria. Based on the GIS analysis, suitable locations were identified in each municipality first, and then the total Required Surface Area of these systems was compared to the available Surface Area of each municipality, in order to decide whether SP systems could be a viable solution to the wastewater management problem in the particular region. In that way the present methodology offers a fast and simple method to check the suitability of new Areas for construction of such systems.