Plasmodium falciparum takes advantage of two broadly defined alternate invasion pathways when infecting human erythrocytes: one that depends on and the other that is independent of host sialic acid residues on the erythrocyte surface. Within the sialic acid-dependent (SAD) and sialic acid-independent (SAID) invasion pathways, several alternate host receptors are used by Plasmodium falciparum based on its particular invasion phenotype. Earlier, we reported that two putative extracellular regions of human erythrocyte band 3 termed 5C and 6A function as host invasion receptor segments binding parasite proteins MSP1 and MSP9 via a SAID mechanism. In this study, we developed two mono-specific anti-peptide chicken IgY antibodies to demonstrate that the 5C and 6A regions of band 3 are exposed on the surface of human erythrocytes. These antibodies inhibited erythrocyte invasion by the Plasmodium falciparum 3D7 and 7G8 strains (SAID invasion phenotype), and the blocking effect was enhanced in sialic acid-depleted erythrocytes. In contrast, the IgY antibodies had only a marginal inhibitory effect on FCR3 and Dd2 strains (SAD invasion phenotype). A direct biochemical interaction between erythrocyte band 3 epitopes and parasite RhopH3, identified by the yeast two-hybrid screen, was established. RhopH3 formed a complex with MSP119 and 5ABC region of band 3, and a recombinant segment of RhopH3 inhibited parasite invasion in human erythrocytes. Together, these findings provide evidence that erythrocyte band 3 functions as a major host invasion receptor in the SAID invasion pathway by assembling a multi-protein complex composed of parasite ligands RhopH3 and MSP1.

This report documents the results of an extensive sensitivity study conducted by the Idaho National Engineering and Environmental Laboratory. This study investigated the effects of various operating and design parameters on wellbore heat exchanger performance to determine conditions for optimal thermal energy extraction and evaluate the potential for using a wellbore heat exchanger model for power generation. Variables studied included operational parameters such as circulation rates, wellbore geometries and working fluid properties, and regional properties including basal heat flux and formation rock type. Energy extraction is strongly affected by fluid residence time, heat transfer contact area, and formation thermal properties. Water appears to be the most appropriate working fluid. Aside from minimal tubing insulation, tubing properties are second order effects. On the basis of the sensitivity study, a best case model was simulated and the results compared against existing low-temperature power generation plants. Even assuming ideal work conversion to electric power, a wellbore heat exchange model cannot generate 200 kW (682.4e+3 BTU/h) at the onset of pseudosteady state. Using realistic conversion efficiency, the method is unlikely to generate 50 kW (1 70.6e+3 BTUh).

Concentration dependent SPS FO water treatment processes energy model. • SPS FO process modeled with and without geothermal energy contributions. • SPS FO found to be economically viable over a wide range of concentrations.A model was developed to estimate the process energy requirements of a switchable polarity solvent forward osmosis (SPS FO) system for water purification from aqueous NaCl feed solution concentrations ranging from 0.5 to 4.0 molal at an operational scale of 480 m 3 /day (feed stream). The model indicates recovering approximately 90% of the water from a feed solution with NaCl concentration similar to seawater using SPS FO would have total equivalent energy requirements between 2.4 and 4.3 kWh per m 3 of purified water product. The process is predicted to be competitive with current costs for disposal/treatment of produced water from oil and gas drilling operations. Once scaled up the SPS FO process may be a thermally driven desalination process that can compete with the cost of seawater reverse osmosis.

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DISCLAIMERPortions of this document may be illegible in electronic image products. Images are produced from the best available original document. ACKNOWLEDGEMENTSThe work i n t h i s report was undertaken t o answer a question put t o one o f the authors by Raymond LaSala o f the Department o f Energy's Geothermal Division. Ray asked how closely an actual binary geothermal system could approach the thermodynamic maximum conversion o f the thermal energy i n the geofluid t o work, f e e l i n g t h a t 75% might leave s i g n i f i c a n t room f o r improvement. One o f the authors (CJB) could not answer the question related t o the magnitude o f the i r r e v e r s i b i l i t i e s associated with the necessary transfer o f heat (pinch points o r l o g mean temperature differences) and conversion t o work i n r o t a t i n g machinery (isentropic efficiencies). This report i s the r e s u l t o f our thinking on t h i s subject. Thanks, Ray.The report has been reviewed by several people i n the i n d u s t r i a l sector f o r t h e i r perspective. We acknowledge the e f f o r t o f Richard Campbell o f the Ben H o l t Company, Michael Forsha o f Barber Nichols Engineering, and Joel Rosenbl a t t and Stanley Saulson o f Polythermal Technologies Corporation f o r t h e i r review o f the i n i t i a l report. I n addition, we thank the people a t Exergy Inc. who generated the numbers f o r comparable cases f o r t h e i r System 12 t o the performance o f the other systems. who gave us the "Rule-of-Thumb" t h a t economic optimization occurred a t second law e f f i c i e n c i e s i n the neighborhood o f 70 t o 75% f o r systems o f the type being considered here.