Shale gas - How does it affect the Gas market?

Imperial Users onl

Porous ceramics for multistage Knudsen micropumps—modeling approach and experimental evaluation

This paper describes the evaluation of four types of porous ceramics for use as thermal transpiration materials in Knudsen pumps that operate at atmospheric pressure. Knudsen pumps are motionless gas pumps that utilize thermal transpiration along a channel or a set of channels; the channels must have a temperature gradient and must constrain the flow to remain within the free molecular or transitional flow regimes. Of the ceramics evaluated, a clay-based, 15 bar synthetic ceramic (15PC) presents the most favorable properties for Knudsen pumps. For an input power of 3.4 W, a 25 _ 25 mm 2 nine-stage Knudsen pump that uses this material provides a maximum pressure head of 12 kPa and a maximum gas flow rate of ≈3.7 µL min _1 . Reliability tests demonstrate more than 11 750 h of continuous operation without any deterioration in their gas pumping capabilities. A fitted model suggests that the temporal evolution of pressure at the sealed outlet of a Knudsen pump can be captured adequately using four parameters. These parameters correspond to various nonidealities that play dominant roles in the transient response of these pumps.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90805/1/0960-1317_21_9_095029.pd

Stem Cell Antigen CD34 In Native And Engineered Form Alter Its Binding Ability To Stromal Cells And Ligands: A Classical Example Of Clinical Benefits Of Therapeutic Genetic Engineering Of Stem Cells In Transplantation

CD34 is a highly glycosylated surface-expressed sialomucin and, because it is present on hematopoietic stem cells (HSCs), has demonstrated immense clinical utility in their enumeration in aphaeresis products, immunoaffinity purification for transplantation, and disease monitoring. The success of CD34 based reagents in identifying hematopoietic progenitors led to the assumption that CD34 is expressed on cells with regenerative potential and is sufficient for hematopoietic reconstitution in marrow-ablated recipients. However, its role has not been identified in substantial detail. 

With the advent of the fact that CD34 binds adapter protein like CRK-L in cytosol and CD34 knock out studies identified a a signaling role, CD34 antigen has been proposed to play a signaling function. Since it is a sialomucin, a member of the group adhesion molecules, we attempted to identify a role by over-expreesing its gene in cell lines. We report here that CD34 and engineered forms (Ser306 & Tyr318) significantly regulates adhesion to stromal cells, like mesenchymal stem cells and bone marrow ligands. These enhance binding of cells overexpressing CD34 by upregulating integrins and we therefore propose that such cells may effectively potentiate the success of transplantation through greater homing if they are used for transfusion

An Assessment of Water Quality of River Yamuna at Waterworks Station, Agra

The present study is an effort to know the water quality of river Yamuna. The water of river Yamuna is collected and treated before supplying to the city. As the Yamuna river comes to Agra passing through several cities, some of them are industrial which dump their waste into the river. Besides this city waste or sewage is also dumped. As the river Yamuna passes through Ghats due to which various organic, as well as inorganic waste, are also added to the Yamuna river which increases the pollution load. “During our study at Waterworks, Agra, It was observed that the pH, Hardness, Chloride, and Alkalinity are always higher than the IS Standards. In river Yamuna's water due to dumping problem many problems arise which increases the colour, pH as well as other physiochemical parameters. Due to which the colour becomes higher than the normal standard as by IS standards (Which is maximum 20 Hazon)”. Due to such an increased pollution in Yamuna river water, the water treatment at Waterworks, Agra become difficult and the chlorine dosing (Which is used for disinfection) and Alum dosing (For sedimentation) becomes higher and dosing quantity changes according to the seasonal variation in Yamuna river water