Purification of eutrophic water by ryegrass

The present study was carried out to investigate the growth characteristics of different ryegrass (Lolium perenne L.) cultivars and their ability to remediate eutrophic water using floating plant-bed technology. Greenhouse and lake experiments were conducted to evaluate the grass genotypes for water remediation. Twelve cultivars of ryegrass including Grazer, Secale Cerale, Energa, Rustmaster, AngusI, Abundant, AngusII, Jivet, Gulf, Surrey, Major and Barwoltra were grown in the floating plant-bed system. The plant biomass, plant NP (nitrogen and phosphorus) accumulations and the water purification capacity of selected grasses were significantly different (P < 0.05). Abundant, AngusII and Major showed most efficient purification capacity of eutrophic water. In a greenhouse, after 26 days of growth, the eutrophic water was purified to various extents by the different ryegrass cultivars. Nitrogen removal efficiency varied from 52.20% to 73.82% and phosphorus removal efficiency ranged from 75.12% to 84.77%. In a lake experiment at Huajiachi pond, after 162 days of growth, the plant shoot biomass increased from 321.5 to 922.8 g/m(2) dry weight basis, shoot NP accumulation ranged from 61.5 to 168.2 mg m(-2) d(-1) and 11.9 to 47.2 mg m(-2) d(-1) respectively. NP accumulation rate by the various cultivars of ryegrass was highly positively correlated to their biomass production and water purification capacity. Thus, plant biomass could be used as an indicator for assessing purification capacity of a ryegrass cultivar.     

Reconstruction of scene using corneal reflection

Multimedia Tools and Applications - Corneal reflection extracted from an eye image identifies the relationship between the subject of the image and the scene in front of the subject. The...     

Lipids of berseem (Trifolium alexandrinum) seed

Berseem seed oil was fractionated into non-polar and polar components. Tentative identification was made of hydrocarbons, sterol esters, triglycerides, free fatty acids and partial glycerides in the non-polar fraction and of lysophosphatidyl choline, phosphatidyl inositol, lysophosphatidyl ethanolamine, phosphatidyl choline, phosphatidyl glycerol, phosphatidyl ethanolamine, digalactosyl diglycerides, sterol glycosides, phosphatidic acid, monogalactosyl diglycerides, cerebrosides and esterified sterol glycosides in the polar fraction. The fatty acid constituents of the major polar and of all the non-polar lipid components are also reported.     

GEANT4 simulation of photo-peak efficiency of small high purity germanium detectors for nuclear power plant applications

GEANT4 – based Monte Carlo simulations have been carried out for the determination of photo-peak efficiency of heavily shielded small high purity germanium detector (HPGe) used for monitoring radiation levels in nuclear power plants. The GEANT4 simulated values of HPGe detector efficiency for point as well as for disk sources, for two different values of collimator diameter, have been found in good agreement with the corresponding published results obtained by using the MCNP code. The work has been extended to study the effect of radial displacement of a source relative to a detector on photo-peak efficiency for both point and disk source, and at various values of γ-ray energies. Also the effect of disk source radius on photo-peak efficiency has been studied. Besides the results of different available physics models in GEANT4 have also been compared. The computed values of efficiency for point as well as for disk sources using the Penelope and Livermore physics models have been found correspondingly consistent for various values of γ-ray energies while some differences (e.g., Penelope model yields 6.3% higher values of photo-peak efficiency for Eγ = 1.332 MeV, 10 mm collimator diameter) have been observed in the corresponding valued obtained by using the Standard physics model.     

Analysis of rail potential and stray current in MVDC railway electrification system

In contrast to the conventional direct current railway electrification system (DC-RES), the medium voltage direct current (MVDC)-RES is considered promising for long-distance high-speed corridors. In the MVDC-RES, traction substations (TSSs) are placed much farther and train loads are much heavier than in the conventional DC-RES. Hence, the MVDC-RES brings a drastic change in catenary voltage, TSS spacing, and train loading, which affects rail potential and stray current. In this connection, this work performs some significant quantitative analysis of rail potential and stray current in the MVDC-RES environment. An MVDC simulation model is proposed and different grounding schemes are analyzed for a single-train and two TSSs scenario as well as for a multi-train multi-TSS scenario. According to the simulation and analysis, the maximum values of rail potential and stray current at MVDC-RES distances and the maximum safe distance between adjacent TSSs are determined.

     

Maleated High Density Polyethylene Compatibilized High Density Polyethylene/Hydroxyapatite Composites for Biomedical Applications: Properties and Characterization

The study investigated the use of maleated high density polyethylene (mHDPE) as a compatibilizer in high density polyethylene/hydroxyapatite (HDPE/HA) composites for biomedical applications. The addition of HA increased the strength and stiffness of HDPE/HA composites while the use of mHDPE in HDPE/HA composites improved its elongation at break values. The SEM images revealed that the addition of mHDPE has induced the formation of HDPE fibrils in mHDPE/HA composites. The size of apatite layer increased with simulated body fluid (SBF) immersion time and the formation of apatite layers on the surface of composites indicates excellent biocompatibility properties.