Mathematical and experimental investigation of water migration in plant xylem

Plant can take water from soil up to several metres high. However, the mechanism of how water rises against gravity is still controversially discussed despite a few mechanisms have been proposed. Also, there still lacks of a critical transportation model because of the diversity and complex xylem structure of plants. This paper mainly focuses on the water transport process within xylem and a mathematical model is presented. With a simplified micro channel from xylem structure and the calculation using the model of water migration in xylem, this paper identified the relationship between various forces and water migration velocity. The velocity of water migration within the plant stem is considered as detail as possible using all major forces involved, and a full mathematical model is proposed to calculate and predict the velocity of water migration in plants. Using details of a specific plant, the velocity of water migration in the plant can be calculated, and then compared to the experimental result from Magnetic Resonance Imaging (MRI). The two results match perfectly to each other, indicating the accuracy of the mathematical model, thus the mathematical model should have brighter future in further applications

A Novel Process for Making Radiopaque Materials Using Bauxite-Red Mud

Red mud, which is an aluminum industry waste, has been utilized1 for making X-ray radiation-shielding materials. A novel method for making radiation shielding materials utilizing red mud and barium compound has been developed by ceramic processing route using phosphate bonding. The red mud based shielding materials (RMSM) are characterized for their X-ray attenuation characteristics. The shielding, i.e. half value thickness (HVT) for different energies of X-ray photons for RMSM have been computed and compared with conventionally used shielding materials namely concrete and lead, it is found that the (HVT) of the red mud based shielding materials, in comparison to concrete, is significantly very less for the various energies of X-ray photons. The X-ray powder diffraction studies confirmed the presence of celsian, bafertiste and iron titanium oxide as the major shielding phases in the RMSM. Scanning electron microphotographs have revealed the compacted and continued integrated morphological characteristics of the various shielding phases in the matrix of shielding materials. The mechanical properties namely compressive strength and impact strength evaluation test showed that RMSM meets the standard specifications laid down for radiation shielding concrete and ceramic tiles. Based on the above studies, it is found that RMSM, can preferably be used for the construction of X-ray diagnostic and CT scanner room to provide adequate shielding against X-ray photons

Development of Celsian Ceramics from Fly Ash Useful for X-Ray Radiation Shielding Applications

For the first time the capability of fly ash to produce barium containing radiopaque materials has been demonstrated. Fly ash which is a waste generated in power plants due to combustion of pulverized coal, has been utilizeda for making X-ray radiation-shielding materials. A novel method for making radiation-shielding materials utilizing fly ash and barium compound has been developed by ceramic processing route using phosphate bonding. The fly ash based radiopaque materials (FARM), i.e. shielding materials are characterized for their X-ray attenuation characteristics. The shielding, i.e. half value thickness (HVT) for different energies of X-ray photons for FARM have been computed and compared with conventionally used shielding materials, namely concrete and lead, it is found that the HVT of the fly ash based shielding materials, in comparison to concrete, is significantly very less for the various energies of X-ray photons. The X-ray powder diffraction studies confirmed the presence of monoclinic and hexagonal celsian and sanbornite as the major shielding phases and potassium aluminosilicate, sodium aluminosilicate and silicophosphate as the binder phases in the FARM and are responsible for providing bonding to the ceramic matrix leading to the effective shielding and mechanical properties. Scanning electron microphotographs have revealed the compacted plate like particles with hexagonal morphological characteristics of the various barium silicate and barium aluminosilicate (BAS) shielding phases in the matrix of radiopaque materials. The mechanical properties, namely compressive strength and impact strength evaluation test showed that FARM meets the standard specifications laid down for radiation-shielding concrete and ceramic tiles. Based on the above studies, it is found that FARM, can preferably be used for the construction of X-ray diagnostic and CT-scanner room to provide adequate shielding against X-ray photons

Chemically formulated ceramic gamma ray irradiation shielding materials utilising red mud

Novel shielding materials for electromagnetic radiations have been formulated using two different approaches using red mud and processed red mud based systems. The crystallographic aspect of multicomponent and multishielding phases, in the formulated shielding materials, on the shielding efficiency has been studied. The formulated shielding materials have been evaluated for radiation attenuation using Co-60 gamma ray irradiation source and were found to reduce the shielding thickness, i.e. half value thickness, to about 40–60% of concrete. The X-ray diffraction studies confirmed the presence of bafertisite, sanbornite, celsian and troilite as the major shielding phases and phosphates of aluminium and iron as the binder phases. The SEM revealed the highly compacted and continued integrated morphological features of various shielding phases. The unique combination of these different phases is responsible for providing bonding to the ceramic matrix leading to the effective shielding and mechanical properties

Removal of Heavy Metals Using Hybrid Precursor Prepared from Agro Residue (Rice Husk)

Rice husk is an abundantly available waste material in all rice producing countries. In certain regions this low value agricultural by product is used as a fuel for parboiling paddy in rice mills, it produced 13-15MJ/kg of energy. The partially burned rice husk in turn contributes to more environmental pollution. This rice husk contains nearly 20 percent silica, can be made into adsorbent material, which is used, in environmental remediation. Developed countries have accepted and followed the concept of “no waste” and all such materials are termed as “new resources” for new material development through value addition. In the present study hybrid precursor, which contains both carbon and silicon, used for the removal of heavy toxic metals, such as lead, copper and zinc present in wastewater .The efficiency of the hybrid precursor in the removal of heavy metals is approximately 90%

Synthesis and characterization of Poly (N- Isopropylacrylamide) ZnO nanocomposites for textile applications

High performance polymers exhibiting multifunctional characteristics can be achieved by the introduction of inorganic nanoparticles like ZnO(Zinc oxide) into the functional polymers. In the present work a copolymer epoxy poly (dimethylacrylamide) was synthesized to disperse the ZnO nanoparticles. The aim of the work is to develop a new method/process/material for the dispersion of nanoparticles and evaluation of the performance of these composites. FT-IR studies of the polymer adsorbed ZnO nanoparticles confirmed that the polymer molecules chain were anchored on the surface of the ZnO nanoparticles. The improved interfacial interaction between the particles and polymer enhanced the thermal properties of the composites. The results also show that the newly prepared polymer composite matrix uniformly has the ability to disperse the ZnO nanoparticles well as evidenced by SEM analysis, and the particles almost remain in their original shape and size even after incorporation into the polymer matrix. Nevertheless, it was also found by dynamic light scattering analysis that the mean particle size of the dispersion was increased with increasing ZnO content. The results were consistent with SEM observations. The value of zeta potential results, show how the Poly (N–isopropylacryl amide (PNIPAM) can adsorb onto the ZnO nanoparticles and impart – ve charge to the surface of the nanoparticles.Department of Science and Technology (DST), India and Fundação para a Ciência e a Tecnologia (FCT), Portugal