In principle a very large quantity of electric power could be produced by the worldwide application of pressure-retarded osmosis (PRO) to the osmotic pair, river water/sea water. The utility of the process depends on the economics, i.e., whether the produced energy cost, dollars per kilowatt hour, and the plant capital cost, dollars per kilowatt, can be adequately low. The study was limited to spiral modules, i.e., originally flat sheet membranes. A very important cost item was the “Yuma” specific plant capital cost of 1000 dollars per daily cubic meter of permeate. This value was derived from consideration of the world's largest RO plant, that in Yuma, Arizona, and was used in PRO calculations with modification as required for differences in flux and for economy-of-scale effects. Within these limitations, the key parameters were found to be twofold: First was the K term in PRO. This is the resistance to salt diffusion in the porous substructure and support fabric region of the membrane and must be as low as possible because an increase in K decreases permeate flux virtually exponentially. Second was the size of the PRO plant, characterized by the flow rate of the river utilized. The larger the PRO plant, the more important the economy-of-scale factor becomes in minimizing the energy and power costs mentioned above. A key assumption in the comparative plant cost calculations was that half of such costs would be independent of changes in plant flux and the other half proportional to it. Based on previous PRO tests and some optimism, K terms of 10 and zero were considered. A “moderate” river flow rate of 3 million m3/d flow rate was considered as well as a “large” river size, that of the Mississippi, 1,500 million m3/d flow rate. The following was found: A “moderate” flow rate PRO plant with an optimistically low K term of 10 d/m (permeate flux 0.29 m3/m2d) would give unacceptably high energy and power costs as would a moderate plant with K = 0 (flux 0.725 m3/m2d). A Mississippi river plant with K = 10 would produce marginal energy and power costs, i.e., higher than expected from conventional existing power plants and perhaps acceptable under certain circumstances but with a K value of zero would produce adequately low energy and power costs. If the specific plant capital cost estimate could be reduced from 1000 to 500 dollars per daily cubic meter of permeate, as reported by some RO investigators, all PRO costs would be reduced by about half, thus rendering the moderate flow rate PRO plant with K = 0 marginally acceptable and both Mississippi PRO plants acceptable in terms of low energy and power cost. In view of these possibilities and the tremendous amount of benign and renewable energy and power potentially available, it is believed that river water/sea water PRO should be seriously investigated.

In recent years two types of very large-scale plants have been proposed for handling seawater brought to the Dead Sea, both processes taking advantage of the 400 m drop to Dead Sea level and both sized to replenish the 3,000,000 m3/d evaporation rate of the Dead Sea. Pressure-retarded osmosis (PRO), the process discussed herein, would use the replenishment stream to produce an appreciable amount of benign and renewable electric power. If the seawater plant prior to PRO would be reverse osmosis (RO), handling 5,000,000 m3/d to produce 2,000,000 m3/d of fresh water, PRO could produce 48,000 kW from the RO-concentrated seawater feed at a capital cost for power of about $4,000 per kilowatt and a PRO plant cost of $190,000,000. The electrical energy would be produced at a cost of about $0.07/kWh. The PRO plant would use a DuPont B-9 type or similar hollow fiber modified to have 110 and 320 micron internal and outer diameters (instead of 40 and 90). Osmotic permeation of half of the 3,000,000 m3/d RO reject brine into Dead Sea brine would produce 35 atmospheres of hydrostatic pressure relieved by passage of an equivalent volumetric rate of diluted Dead Sea brine through a hydroturbine/generator set. The second type of plant prior to PRO would use 3,000,000 m3/d of seawater to produce hydropower, estimated at about 130,000 kW. The permeation rate in PRO could then be 2,000,000 m3/d enabling power production in PRO of 70,000 kW at a capital cost for power of $3,300 per kilowatt and a PRO plant cost of $230,000,000. The cost of produced energy in PRO would be $0.058/kWh. It is believed that the Great Salt Lake should also be examined as a site for PRO.

Commercially available asymmetric membranes of the Loeb-Sourirajan (L-S) type comprise a support fabric, bonded to the porous substructure. The influence of this fabric on osmotic permeation flux was examined, mostly with a Toray CA-3000 membrane from which, with care, it was possible to remove the support fabric. In osmosis experiments with 12% MgCl2 solution on one side (either side) and 6% solution on the other, the permeation flux (J(1)) was of the order of 0.01 and 0.06 m(3)/m(2) d with and without fabric, respectively. These results could be generalized by considering the resistivity to solute diffusion in the non-skin part of the membrane. This resistivity term averaged 104 and 17 d/m for membranes with and without fabric, respectively, and in further tests without fabric, it was between 15 and 25 d/m over a wide range of MgCl2 concentrations. Four other L-S membranes, all with support fabric, were tested in osmosis experiments. Their resistivity values were similar to or higher than those of the Toray membrane with fabric, but, with one of the four, the results were affected by switching the location of the high and low concentration solutions. It was concluded that existing commercially available L-S membranes are not appropriate for large-scale osmosis applications because their support fabric decreases permeation flux excessively.

A new heat transporter is described, the tiltpipe liquid thermosiphon (TLT). In service, a straight, sealed pipe, filled with liquid, is maintained in a tilted orientation. By means of the contained liquid, heat is received from a heat source at the lower end of the pipe, transported to the elevated end, and delivered to a heat sink. The heat transport rate and the temperature distribution in the TLT were studied over a wide range of tilts, with water as the liquid, contained in a steel pipe. At its optimum tilt the TLT combined a high heat transport rate with virtually no temperature degradation in the water from end-to-end of the pipe. In both of these criteria the TLT far exceeded the performance of the unit in vertical orientation, the only one examined by previous investigators. Another characteristic difference between the tilted and the vertical unit was that at any given pipe cross section in the heat transport region (i.e., between the heat source and the heat sink), the water in the tilted pipe had a higher temperature near the top of the cross-section than near the bottom. With vertical orientation there was no such temperature difference. The experimental results with the TLT, particularly in the region of the optimum tilt, were explainable in terms of a liquid thermosiphon mechanism, but a unique one. It was inferred that there was cyclical countercurrent flow of contiguous streams in a single pipe with a warmer, less dense water stream flowing axially upward through a top segment of the pipe cross-section and, separated by a quiescent interfacial plane, a cooler, more dense water stream flowing axially downward, through a bottom segment. It followed that at the pipe terminals each stream reversed itself, becoming its opposite by virtue of heat receipt/delivery at the heat source/sink. The contiguous, countercurrent flow pattern described above was confirmed visually at the optimum tilt of eleven degrees by observation of water flow inside a clear plastic tube added to the midsection of the steel pipe. The streams were rendered visible by injections of soluble coloring material in the water at the elevated and lowered ends of the pipe.

Mechanical efficiencies have been compared for several plant configurations utilizing a pressure-retarded osmosis (PRO) energy converter. In this comparison reliance has been placed on previously obtained experimental data of Honda in a reasonably sized PRO module with hollow fibers sized for PRO use. These data were obtained with a 3.5 percent NaCl solution, i.e. one fairly close to sea water.

The presence of atrazine, a triazine herbicide, and its residues in agriculture soil poses a serious threat to human health and environment through accumulation in edible plant parts. Hence, the present study focused on atrazine induced stress amelioration of Andrographis paniculata, an important medicinal plant, by a plant growth promoting and atrazine degrading endophytic bacterium CIMAP-A7 inoculation. Atrazine has a non-significant effect at a lower dose while at a higher dose (lower: 25 and higher: 50 mg kg−1) 22 and 36% decrease in secondary metabolite content and plant dry weight of A. paniculata was recorded, respectively. Endophyte CIMAP-A7 inoculation significantly reduced atrazine soil content, by 78 and 51% at lower and a higher doses respectively, than their respective control treatments. Inoculation of CIMAP-A7 exhibited better plant growth in terms of increased total chlorophyll, carotenoid, protein, and metabolite content with reduced atrazine content under both atrazine contaminated and un-contaminated treatments. Atrazine induced oxidative stress in A. paniculata was also ameliorated by CIMAP-A7 by reducing stress enzymes, proline, and malondialdehyde accumulation under contaminated soil conditions than un-inoculated treatments. Furthermore, the presence of atrazine metabolites deisopropylatrazine (DIA) and desethylatrazine (DEA) strongly suggests a role of CIMAP-A7 in mineralization however, the absence of these metabolites in uninoculated soil and all plant samples were recorded. These findings advocate that the amelioration of atrazine induced stress with no/least pesticide content in plant tissues by plant-endophyte co-interactions would be efficient in the remediation of atrazine contaminated soils and ensure safe crop produce.

In June of 1965, a tubular reverse osmosis desalination plant was installed at Coalinga, California . The plant was intended to obtain data characteristic of operation in the field and simultaneously to provide 5000 GPD (gallons per day) (19 m 3 /d) of fresh water to the residents of Coalinga . Thus the unit was both a pilot plant and the first municipal RO desalination plant. How did this plant come about? The story begins with a visit by Dr . Glenn Havens to the University of California, Los Angeles, (UCLA) Laboratory in 1963. Havens was a successful manufacturer of fiberglass-reinforced tubular fishing poles. Using the Loeb-Sourirajan casting techniques, applied by us hitherto only to produce flat sheet membranes, he had cast cellulose acetate membranes on the inside of one half inch (13 mm) fiberglass-reinforced tubes, starved of resin sufficiently to make them porous but not enough to lose their capability to withstand the internal brine pressure [1] . From discussions with Havens and a visit to his facilities in San Diego it was clear to us that the performance of his coated tubes was not nearly as good as that of our flat sheets . Nevertheless, we were enthusiastic about the concept and Havens' vigorous prosecution of it . We obtained $15,000 from State-supported University funds to buy and test a 5000 GPD unit from Havens . This capacity required several hundred tubes and considerable manufacturing time. Therefore we agreed to pay $5000 for a working unit with enough tubes to start evaluation, with the succeeding $5000 payments upon delivery of tubes sufficient for substantial and for full capacity . In the spring of 1964, it was our opinion that we could accept the working unit and a check for $5000 was sent to Havens . A few days later I telephoned him to say we were coming to San Diego to pick up the unit . He said that there was a problem . He had allied himself with Richfield Petroleum Corporation and they wanted a meeting before delivery .