Higher Water Yield Research Articles

Photocatalysts split water in high yield

Photocatalysts split water in high yield

Production and Loss of Methylmercury and Loss of Total Mercury from Boreal Forest Catchments Containing Different Types of Wetlands

Four terrestrial boreal forest catchments containing different types of wetlands were studied to determine their strength as sources or sinks of methylmercury (MeHg) and total mercury (THg) to downstream ecosystems and to determine if patterns seen in one year were consistent over several years. All catchments were sinks for THg. The wetland type, percentage wetland area (0−25%), or annual water yield did not appear to have a consistent effect on the magnitude of this retention. Wetland areas of the catchments were always net sources of MeHg. Unlike for THg, there were large and consistent differences in the source strength among wetland types for MeHg. These differences appeared to be related to differences in the internal hydrology of the wetlands. All types of wetlands were greater sources of MeHg during years of high water yield, but even during years of low flow all wetland types were sources of MeHg. Thus, we conclude that wetlands are important sites of MeHg production in boreal ecosystems on the l...

Reactivity and structure of two coals containing significant methoxy group concentrations

Two coals (Beulah, PSOC-1483, and a Thai coal, TH23) of unusually high reactivity with hydrogen and tetralin were shown to contain significant methoxy group contents. The fate of the methoxy groups when these coals were reacted under N 2 at 320°C (with and without added decalin) and with H 2—tetralin and H 2SnO 2 at 405°C was studied. The reactions of TH23 coal gave unexpectedly high water yields. Reactions of model compounds containing methoxy groups under similar conditions also gave high water yields. Proton magnetic resonance thermal analysis (PMRTA) confirmed that TH23 host and guest coal components are structurally distinct from those of Loy Yang (Victoria) run-of-mine coal.

Chemoselective Oxidations in Water of Functional Groups

Abstract The organic functional groups, formyl, cyano, hydroxymethyl and methylsulfenyl, are oxidized with high yields in water only by using TBHP and controlling the pH of the reaction medium. In the presence of (CTA)2SO4, the oxidation of the easily oxidizable sulfide group is prevented and a highly chemoselective process is obtained. The role of the surfactant is discussed.

Upgrading of flash pyrolysis oil and utilization in refineries

Abstract Flash pyrolysis oil from an ENSYN RTP pilot plant was upgraded in a continuous bench scale unit with commercial CoMo and NiMo catalysts in anticipation of scaling up the process. Large amounts of product were produced in a pilot plant for use in an extended analytical characterisation programme. In bench-scale experiments, high deoxygenation rates of 88–99.9% were achieved. Low liquid and high water yields were obtained. The fractionated products of the production run did not fulfil the requirements for direct use as gasoline and diesel. The process is restricted by several operational problems such as rapid catalyst deactivation, coking and plugging. Due to high feedstock and hydrogen addition costs, pyrolysis upgraded oil by the process tested is significantly more expensive than petroleum-derived oil at present oil prices.

Noncatalytic Conversion of Cellulose in Supercritical and Subcritical Water.

This paper describes the noncatalytic conversion of cellulose in supercritical and subcritical water. First, it was demonstrated that even without any acid catalyst, cellulose was rapidly converted to water soluble species with a relatively high glucose yield in near critical water and glucose yield increased with elevating temperature. Then the rate constants for cellulose decomposition and glucose decomposition were evaluated at a pressure of 25 MPa over a temperature ranging from 473 K to 673 K by using semi-batch reactor and a flow reactor, respectively. From the reported cellulose pyrolysis rate constant and the evaluated cellulose decomposition rate constant, cellulose hydrolysis rate constant was evaluated. By using the cellulose hydrolysis rate, cellulose pyrolysis rate and the glucose decomposition rate, glucose yield obtained in the semi-batch experiment was reasonably explained.

Ion exchange reaction of [ 18F]fluoride with an oxidized carbon surface

[ 18F]Fluoride was trapped from [ 18O]water in high yield by ion exchange on a microporous carbon prepared by controlled oxidation to produce a cationic surface with an exchange capacity of about 350 μ equiv/g. The [ 18F]fluoride could be recovered by displacement with aqueous K 2CO 3. The cationic carbon offered a dimensionally rigid matrix of high thermal stability. It was characterized with respect to chemical reactivity and selectivity for anion exchange.

Aqueous carbonic acid: A readily removable electrolyte for the recovery of [ 18F]fluoride from anion exchange resins

[ 18F]Fluoride was recovered from [ 18O]target water in high yield by trapping it on a microcolumn of an anion exchange resin (20 mg Dowex 1 × 8, 400 mesh) and subsequent elution of the column (in the reverse direction) by aqueous carbonic acid at 52 atm. The carbonic acid was removed from the [ 18F]fluoride solution by brief heating at 85°C, 1 atm. Thus no extraneous electrolyte was introduced by the extraction process. The resulting bicarbonate form of the resin was immediately capable of trapping further [ 18F]fluoride, permitting a repetitive remote system for recovery of [ 18O]water. Chloride was substantially retained on the column permitting separation of [ 18F]fluoride from the former.

Simulation of the primary stage of liquid water radiolysis

The computer simulation of the primary stage of liquid water radiolysis have been made for irradiation by fast electrons with E 0= 1, 5 and 10 keV. The specific features of the liquid phase in comparison with gas phase are taken into account, such as the essential lowering of ionization potential and plasmon-type collective excitations. These factors result in high ionization yield in liquid water g i=6.57, that is more than 4 times greater than the total excitation yield g ex=1.43. The evolutions of excited and ionized states have been considered from which it follows that the electron-ion recombination must be taken into account. The water molecules resulting after recombination are created in highly excited vibrational states with yield g vib=1.75. The results of our computer simulation have been used for estimation of the yields of the intermediate radiolysis products on the basis of the radiolysis scheme with allowance made for the decay of super-excited states and for the “cage effect”.

Water Regulatory Efficiency in Heteromyid Rodents: A Model and Its Application

We have developed and tested a model of water regulatory efficiency for the rodent family Heteromyidae. The model is based on the premise that granivory coupled with increasing aridity and seasonality of rainfall has been the major theme throughout the evolutionary history of the family; it states further that water regulatory efficiency is negatively correlated with body mass in the family, and that member species are largely dependent upon a common resource packet (seeds) to meet both energy and water needs. A test of the model with five genera and 13 species revealed positive results across the entire family, but the two most speciose genera, Perognathus and Dipodomys, showed seemingly conflicting patterns; the smaller (in mass) genus, Perognathus, conformed strongly to the model, while in Dipodomys water regulatory efficiency was fixed at a level equivalent to that of the largest Perognathus spp. (°35—40 g). At this mass in these genera, in addition, occurs the demarcation between strict quadrupedality (Perognathus) and bipedality (Dipodomys), a strict scaling of cheek pouch volume with mass in Perognathus but independence of mass in Dipodomys, and the common use of torpor in Perognathus, with its near absence in Dipodomys. We interpret our findings to indicate that initially selection favored a decrease in mass with a concomitant increase in water regulatory efficiency and reduction in absolute energy need in heteromyids, tracking progressive aridity during the Tertiary. In Dipodomys, the option of bipedality was adopted, apparently freeing them from energetic constraints imposed strictly by mass, coupled with an intermediate and fixed level of water regulatory efficiency that dictates use of seeds with high metabolic water yields. The quadrupedal Perognathus have retained a mass—specific water regulatory efficiency, ensuring maintenance of both water and energy balance on a broad array (with respect to protein: lipid: carbohydrate and metabolic water yield) of seeds, when their more—limited locomotor powers are consistent with seed availability; torpor is the tradeoff, enhancing survival during energetically demanding periods.

Features of thermal degradation of polyarylate amides

A study was made in the temperature range of 300–500° of thermal degradation of polyarylate amides. Formation kinetics of gaseous and liquid products of decompositions (including water) were examined. It was established that polyarylate amides break down by radical-chain and ionic mechanisms. The proportion of the latter increases with higher water yield.

RESIDUAL EFFECTS OF PHOSPHORUS FERTILIZER. II. FOR WHEAT AND FLAX GROWN ON CHERNOZEMIC SOILS IN MANITOBA

Broadcast applications of 0, 100, 200 and 400 kg P/ha were made on two Chernozemic soils in 1965. The soils were cropped for 8 yr in a continuous wheat-flax rotation. In each year, crops grown on the phosphorus treatments yielded more and had higher phosphorus content than crops grown without added phosphorus. Over 8 yr of cropping, 100 kg P/ha was the most efficient treatment in increasing yield. Yield increases beyond 100 kg P/ha were either not significant or only marginally significant. Wheat used twice as much phosphorus as did flax. Together the two crops used approximately 30, 22 and 14% of the 100, 200 and 400 kg P/ha applied. The NaHCO3-extractable phosphorus level of the 100 kg P/ha treatment after 8 yr of cropping was reduced to about 8 kg P/ha which is considered to be inadequate for crop production. Soils treated with 200 and 400 kg P/ha contained high levels of NaHCO3-extractable P (20–54 kg P/ha) and little response in yield to additional P would be expected in the near future. Annual variation in yield and phosphorus uptake by the crops were affected by water supply. In years of high water supply, yield and phosphorus uptake were generally higher than in years of low water supply.

Preparation of Some New Ethylene Glycol Monoesters and Mixed Diesters of Fatty Acids

AbstractTri‐(2‐hydroxyethyl)‐orthoborate, obtained by reaction of ethylene glycol with boric acid, was esterified with palmitic, stearic, arachidic, oleic, hydnocarpic, elaidic and stearolic acids. Pure monoesters were obtained on hydrolysis with water in high yields. Monoelaidate and monostearolate are reported for the first time. The monoesters were reacted with acyl chlorides to yield the mixed diesters, viz., oleostearate, oleopalmitate, oleoarachidate, oleoelaidate, oleostearolate, elaidohydnocarpate, stearocaproate and stearolaurate. Except oleostearate the other compounds are reported for the first time.

Molecular Product and Free Radical Yields of Ionizing Radiations in Aqueous Solutions

Ionizing radiations of different energies and masses cause a perplexing variety of chemical and biological effects. Generally speaking, the chemical yield per unit expenditure of energy in aqueous solutions is higher for light-particle than for heavy-particle radiations. This is due in part to a pronounced effect for systems irradiated with X-rays, y-rays, and electrons. Normally, heavy-particle radiation is as effective in promoting chemical changes in the presence of oxygen as in its absence. However, there is a marked selectivity of action in the systems studied, and generalizations, unless carefully stated, may be misleading. The decomposition of water affords an excellent example of a striking difference between the actions of the a-rays and X-rays. Pure water, if irradiated in vessels containing no gas phase, was found by Fricke and Brownscombe (1) to be stable to X-rays, whereas water containing certain types of impurities of the order of 10-5 M is decomposed. Consequently, it is not surprising that Lea (2), as late as 1947, found the evidence for the decomposition of water by X-rays most contradictory. Alpha rays, on the other hand, decompose pure water in high yield in either the presence or absence of oxygen. These characteristics of ionizing radiations may be explained by the differences existing in the ion density along the track of the particle and by the interaction of free radicals with molecular products. The energy necessary for ion-pair formation in air is only slightly lower for X-rays than for a-rays (32.5 and 35 ev/ip, respectively). Within the limits of experimental error, the energy required per measurable water molecule decomposed in dilute aqueous solutions is 29 ? 3 ev, regardless of the type of radiation. The appreciable differences found in the chemical effects produced by different types of radiation depend solely on the relative numbers of the water molecules yielding molecular products (hydrogen and hydrogen peroxide) and hydrogen and hydroxylfree radicals.

Significance of Pleistocene deposits in the groundwater resources of Illinois

Among the developed and potential sources of large public and industrial groundwater supplies in Illinois, the sand and gravel beds of the Pleistocene rank first. These deposits yield most of the groundwater, yield the greatest quantities of water to specific wells, and contain the largest part of the State's undeveloped resources of low-cost groundwater.Groundwater is one of the vital geologic resources of Illinois. Studies by the Illinois State Geological Survey show that about 55 per cent of the State is underlain by one or more aquifers of industrial importance. Twenty-five of Illinois' twenty-six great industrial cities lie in or near those areas of the State where geology is favorable for groundwater development. Seven of the major industrial cities and at least one hundred other communities depend entirely upon Pleistocene sand and gravel beds for groundwater supplies. Wells of highest water yield (2500-3000 G.P.M.) are constructed in valley-train type sand and gravel deposits which are in many places buried by till. The detection and mapping of these deposits involve integration of geologic and geophysical methods of exploration. These sources of groundwater will be of increasing economic significance where industry can move to the undeveloped areas in which low-cost groundwater can be found in abundance.