Showing papers on "Energy source published in 1974"

Culture Medium for Enterobacteria

Abstract: A new minimal medium for enterobacteria has been developed. It supports growth of Escherichia coli and Salmonella typhimurium at rates comparable to those of any of the traditional media that have high phosphate concentrations, but each of the macronutrients (phosphate, sulfate, and nitrogen) is present at a sufficiently low level to permit isotopic labeling. Buffering capacity is provided by an organic dipolar ion, morpholinopropane sulfonate, which has a desirable pK (7.2) and no apparent inhibitory effect on growth. The medium has been developed with the objectives of (i) providing reproducibility of chemical composition, (ii) meeting the experimentally determined nutritional needs of the cell, (iii) avoiding an unnecessary excess of the major ionic species, (iv) facilitating the adjustment of the levels of individual ionic species, both for isotopic labeling and for nutritional studies, (v) supplying a complete array of micronutrients, (vi) setting a particular ion as the crop-limiting factor when the carbon and energy source is in excess, and (vii) providing maximal convenience in the manufacture and storage of the medium.

Growth with Exhaustible Natural Resources: Efficient and Optimal Growth Paths

Abstract: The proposition that limited natural resources provide a limit to growth and to the sustainable size of population is an old one. The natural resource that was the centre of the discussion in Malthus' day was land; more recently, some concern has been expressed over the limitations imposed by the supplies of oil, or more generally, energy sources, of phosphorus, and of other materials required for production. Those who predicted imminent doom in the nineteenth century were obviously wrong. Were they simply wrong about the immediacy of catastrophe, or did they leave out something fundamental from their calculations? There are at least three economic forces offsetting the limitations imposed by natural resources: technical change, the substitution of man-made factors of production (capital) for natural resources, and returns to scale. This study is an attempt to determine more precisely under what conditions a sustainable level of per capita consumption is feasible, to characterize steady state paths in economies with natural resources, and to describe the optimal growth path of the economy, in particular to derive the optimal rate of extraction and the optimal savings rate in the presence of exhaustible natural resouces. One of the interesting problems posed by the presence of exhaustible natural resources is that some of the basic concepts of growth theory, such as " steady state " and " natural rate of growth ", need to be re-examined. If, for instance, there are two unproduced factors, labour and natural resources, one of which is growing exponentially, the other of which is not growing at all, what is the " natural rate of growth "? In conventional economic discussions, the long-run growth rate of the economy is determined simply by the natural rate of growth and is independent of the savings rate. We shall show that in economies with natural resources, efficient growth paths which differ with respect to savings rate also differ, even asymptotically, with respect to the rate of growth. The analysis of optimal growth paths presents certain technical difficulties, because there are two state variables (the stock of capital per man and the stock of natural resources per man) and two control variables (the rate of extraction of natural resources and the savings rate). Fortunately, by the appropriate choice of variables, the qualitative properties of the path can be completely described. Optimal growth paths for economies with only capital or with just natural resources have been examined elsewhere. Typically, a country begins with little capital and hence, in the former models, optimal growth is characterized by increasing consumption per capita. On the other hand, natural resources act much like a capital good; since the stock

Electric power converter

Abstract: A programmed switching system for converting direct current into alternating current or some other variable current, or for converting alternating current of one frequency into alternating current of another frequency. The system employs a number of stages connected in cascade. Each stage includes an electrical energy source or an electrical energy storage unit and switch means adapted to bypass the energy source or storage unit, to interconnect the source or storage unit with other electrical energy source or storage units across a load in a programmed fashion, and to reverse the direction of current flow in the load to apply, for example, a quasi-sinusoidal voltage across the load.

Applied Aerodynamics of Wind Power Machines

Abstract: This chapter reviews the aerodynamics of various types of wind power machines and indicates advantages and disadvantages of various schemes for obtaining power from the wind. Propeller-type wind turbine theory is reviewed to the level of strip theory including both induced axial and tangential velocities. It is intended that this publication be of use in rapid evaluation and comparative analysis of the aerodynamic performance of wind power machines. The success of wind power as an alternative energy source is obviously a direct function of the economics of production of wind power machines. One of the key areas associated with development of wind power is rotor dynamics. A Savonius rotor requires 30 times more surface for the same power as a conventional rotor blade wind turbine. The Madaras rotor works on the principle of the Magnus effect. The Darrieus rotor has performance near that of a propeller-type rotor and requires power input for starting.

Combination of epithermal and inelastic neutron scattering methods to locate coal and oil shale zones

Abstract: A pulsed source of high energy neutrons is used to irradiate the earth formations in the vicinity of a well borehole. Gamma rays produced by the inelastic scattering of the fast neutrons are observed in four energy regions of the gamma ray energy spectrum corresponding to the inelastic scattering of neutrons by carbon, oxygen, silicon and calcium. Signals representative of the carbon/oxygen, calcium/silicon and carbon plus oxygen gamma rays observed are developed. By appropriately combining these signals with a separately derived hydrogen index log the quality of coal bearing formations or oil shale regions penetrated by the borehole may be determined.

Water Salination: A Source of Energy

Abstract: The thermodynamically reversible mixing of freshwater and seawater at constant temperature releases free energy. Salination power as a resource is comparable with hydroelectric power in magnitude; U.S. freshwater runoff could yield over 10(10) watts. The energy flux available for natural salination is equivalent to each river in the world ending at its mouth in a waterfall 225 meters high. An osmotic salination converter could possibly operate at 25 percent efficiency. This energy source is renewable and nonpolluting. Although its full utilization would destroy estuarine environments, it might be practical for specialized purposes.

Wax in coral mucus: Energy transfer from corals to reef fishes1

Abstract: Mucus from a variety of reef corals has been found to contain wax ester (cetyl palmitate) and triglycerides. Observation revealed extensive mucus feeding by many species of reef fishes. When coral mucus is artificially dispersed fish assemble and avidly ingest it. Coral mucus could be an energy source linking the coral producer and small fish consumers in reef communities.

The formation of solar quiescent prominences by condensation

Abstract: We model the formation of solar quiescent prominences by solving numerically the non-linear, time-dependent, magnetohydrodynamic equations governing the condensation of the corona. A two-dimensional geometry is used. Gravitational and magnetic fields are included, but thermal conduction is neglected. The coronal fluid is assumed to cool by radiation and to be heated by the dissipation of mechanical energy carried by shock waves. A small, isobaric perturbation of the initial thermal and mechanical equilibrium is introduced and the fluid is allowed to relax. Because the corona with the given energy sources is thermally unstable, cooling and condensation result. When magnetic and gravitational fields are absent, condensation occurs isotropically with a strongly time-dependent growth rate, and achieves a density 18 times the initial density in 3.5 × 104 s. The rapidity of condensation is limited by hydrodynamical considerations, in contrast to the treatment of Raju (1968). When both magnetic and gravitational fields are included, the rate of condensation is inhibited and denser material falls. We conclude that: (1) condensation of coronal material due to thermal instability is possible if thermal conduction is inhibited; (2) hydrodynamical processes determine, in large part, the rate of condensation; (3) condensation can occur on a time scale compatible with the observed times of formation of quiescent prominences.

Metabolism in plant storage tissue slices

Abstract: The tissue of resting plant storage organs such as carrots, red beets, sugar beets or potato tubers can be activated by slicing into thin disks and incubation of these fragments in a moist atmosphere for different periods of time (“aging”). Activation comprises the turning-on of various genes with subsequent synthesis of transfer-, ribosomal and messenger RNAs and their transport into the cytoplasm. The immediate consequence of all these primary reactions is a vigorous synthesis of various enzymes and structural proteins which enable the cell to greatly enhanced metabolic activities. Thus, degradation of storage polymers and the procession of the resulting products through glycolysis, the pentose phosphate shunt and the shikimateprephenate-pathway and cellulose biosynthesis occur. Deinhibition of the tricarboxylic acid cycle opens the flow of metabolites into fatty acid, phospholipid and steroid biosynthesis, simultaneously providing the respiratory chain with electrons. In spite of functional modifications within the electron transport chain, the enhanced respiration of tissue slices serves as an energy source for the various energy-dependent reactions of the cell such as syntheses and the uptake of solutes. All of these activities accompany a concomitant dedifferentiation process and ultimately lead to renewed redifferentiation of the tissue slice cell.

Factors affecting autolysis of Neisseria gonorrhoeae.

Abstract: SummaryGlucose-limited cultures of N. gonorrhoeae were susceptible to autolysis. The onset of autolysis was not due to a decrease in pH but rather from depletion of the energy source. Cultures limited by nitrogen or by the addition of chloramphenicol or rifampicin were not susceptible to autolysis. The prevalence of autolytic strains appears to be wide spread.

Three-Dimensional Simulation of Steamflooding

Abstract: This paper describes a 3-dimensional model for numerical simulation of steam injection processes. The model describes 3-phase flow of water, oil, and steam and heat flow in the reservoir and overburden. The method of solution effects simultaneous solution of the mass and energy balances and eliminates the need for iterating on the mass transfer (condensation) term. Laboratory data are reported for steamfloods of 5,780 cp oil in a 1/4 five-spot sand pack exhibiting 3-dimensional flow effects. These experiments provide additional data for the purpose of checking accuracy and assumptions in numerical models. Comparisons of model results with several sets of experimental data indicate a need to account for effects of temperature on relative permeability. Calculated areal conformance of a steamflood in a confined 5-spot is strongly dependent upon the alignment of the x-y grid axes relative to the diagonal joining injection and production wells. It has not been determined which, if either, of the 2 grid types yields the correct areal conformance. (30 refs.)

Low-Temperature-Oxidation Reaction Kinetics and Effects on the In-Situ Combustion Process

Abstract: The kinetics of low-temperature oxidation (LTO) of crude oils in porous media was studied. The order of the reaction was dependent upon the crude but independent of the properties of the porous medium. The activation energy of the reaction was insensitive to the type of crude or porous medium and is in the neighborhood of 31,000 btu/lb mol. LTO reactions also were found to be in the kinetics- influenced region. The measured reaction rates for a 19.9$ API and a 27.1$ API crude indicated higher oxidation rates under similar reaction conditions for the higher API gravity crude. Thus, light crudes are more susceptible to partial oxidation at low temperatures because of their relatively high hydrogen content. Effect of partial oxidation of the crude on the in situ combustion process was studied by experimentally simulating the zones preceding the combustion front where temperatures and injection rates of a linear reservoir model were programed with time according to a predesigned schedule. Oxidation of the crude at temperatures below 400/sup 0/F had significant effects on the behavior of the crude oil-water system in the porous medium at elevated temperatures and on the fuel available for combustion. (22 refs.)

Active Transport of Calcium in Inverted Membrane Vesicles of Escherichia coli

Abstract: Accumulation of (45)Ca(++) was found to occur in membrane vesicles of E. coli prepared by lysis with a French pressure cell. The uptake occurs by active transport, requiring an energy source. Substrates of the electron transport chain, including D-lactate, reduced phenazine methosulfate, and NADH, stimulated accumulation, but this effect was blocked by the addition of cyanide. ATP could also stimulate accumulation, and this effect was blocked by dicyclohexylcarbodiimide. Uncouplers of oxidative phosphorylation inhibited the accumulation driven by either type of energy source. Accumulation of calcium is rapid, reaching the steady-state plateau within 1 min. Addition of phosphate to the assay buffer results in a prolongation of the reaction, allowing for the time-dependent accumulation of calcium for as long as 30 min. Vesicles prepared by lysis with a French pressure cell exhibit almost no ability to accumulate proline, while vesicles prepared by the method of Kaback transport proline but exhibit little energy-dependent transport of calcium. It is suggested that the accumulation of calcium in these vesicles, which are believed to be inverted, reflects a system that in vivo is responsible for the active extrusion of calcium from the cells.

Dark Repair of DNA Containing "Spore Photoproduct" in Bacillus subtilis*

Abstract: The major thymine-containing photoproduct—5-thyminyl-5, 6-dihydrothymine, or TDHT—in DNA of UV-irradiated bacterial spores is known to be removed during spore germination. In normal Bacillus subtilis this removal is now shown to occur both by excision and by a second, distinct, “spore repair” process, which changes the photoproduct to a harmless form in situ. An energy source for the cells, suppliable by glucose, is required for excision to function at all, and for the “spore repair” process to proceed beyond a limited photoproduct removal. Both repairs can function fully in spores germinated in the presence of 150 μg-ml chloramphenicol or 5 μg-ml rifampincin. The “spore repair” mechanism does not function in vegetative cells when these are transformed by TDHT-containing DNA extracted from irradiated baceterial spores.

Computer controlled defibrillator

Abstract: A computer controlled defibrillator comprising a set of electrodes which are engageable with a patient and which are connected to a source of electrical energy by a circuit means. The circuit means comprises storage capacitors, energy selector, computer, manual and reset switches, voltage monitor, current monitor, and output meter. The computer responds to certain external inputs, automatic and manual, and controls the output delivered to the patient. The energy selector permits the selection of the energy which is desired to be delivered to the patient. The sequence is started by closing the manual reset switch which zeroes the output meter and activates the power supply (electrical energy) at a voltage which is dependent on the energy selector. The energy derived from the power supply is stored in the storage capacitors. The energy selector, which is manually set to the energy desired, also feeds an input to the computer. When the manual switch is activated, the computer causes the stored energy source to be connected to the patient through the electrodes. The current monitor and voltage monitor feed instantaneous signals to the computer which computes the energy as a continuous integration process. When the computed energy equals the selected energy, the computer causes the energy source to be disconnected from the patient. The total energy delivered to the patient is indicated as a steady reading on the output meter. A modified form of the defibrillator is also disclosed wherein the magnitude of current in the electrical circuit means may be manually or automatically selected to enable the defibrillator to compensate for the patient''s body weight or body resistance.

Energy source for comet outbursts

Abstract: Development of a mechanism explaining the internal source of energy of comet outbursts. A mechanism is proposed which automatically provides a source of particulate matter which creates a huge surface area which contains a substantial percentage of amorphous ice, so that the phase transition of the amorphous ice to a cubic structure provides a release of energy which may be responsible for the outbursts observed in many comets. In addition, the volume into which the transition can propagate is estimated for a spherical comet with a radius of 5 km.

Studies on the cecal microflora of commercial broiler chickens.

Abstract: A study was made of the cecal microflora isolated from broilers (5-week-old) reared under typical commercial husbandry conditions. Three hundred and twenty-five bacterial strains (randomly isolated from colonies representing 49 to 81% of the microscopic count) were isolated from cecal digesta of six animals on a rumen fluid roll tube medium (M98-5). Seventy-seven percent of these strains consisted of strict anaerobes: gram-negative, pleomorphic cocci (5.2%), Peptostreptococcus (1.5%), gram-positive rods (36.1% as Propionibacterium acnes and Eubacterium sp.), gram-negative rods (18.6% as Bacteroides clostridiiformis, B. hypermegas and B. fragilis) and sporeforming rods (15.7% as Clostridium sp.). Two types of facultatively anaerobic bacteria (gram-positive cocci and Escherichia coli) were also isolated and constituted 17.5% of the remaining flora. The distribution of the bacterial groups isolated from six cecal samples varied considerably. Data on the growth requirements of anaerobic strains indicated that many could be cultured in a simple medium consisting of an energy source, minerals, reducing agent, Trypticase, and yeast extract (or a vitamin mixture in place of yeast extract). The growth of some of these bacteria was also enhanced by CO2 and rumen fluid. These preliminary data suggest that some of the more numerous anaerobes isolated from the chicken cecum may not require complex nutrients for growth and, in fact, may be nutritionally similar to rumen anaerobes.

Lipids of the Spirochaetales: comparison of the lipids of several members of the genera Spirochaeta, Treponema, and Leptospira.

Abstract: The lipid compositions of 17 spirochetes belonging to the genera Spirochaeta and Treponema were investigated and compared with data previously derived from 11 strains of Leptospira. The lipid compositions and lipid metabolism of any of these genera is sufficiently different to be characteristic of that genus and to differentiate it from the other two genera. Members of the genus Leptospira are characterized by their ability to beta-oxidize long chain fatty acids as their major carbon and energy source. With few exceptions, they are incapable of synthesizing fatty acids de novo. The major phospholipid found was phosphatidyl ethanolamine. No glycolipid or phosphatidyl choline was found in these organisms. Members of the genus Treponema studied were incapable of beta-oxidation as well as de novo synthesis of fatty acids. Phosphatidyl choline is the major phospholipid of this genus. The glycolipid, monogalactosyl diglyceride, is a major component of the Treponema. Members of the Spirochaeta did synthesize fatty acids de novo. Although these spirochetes contain a monoglycosyl diglyceride, the hexose content of the glycolipid varied from species to species. Neither phosphatidyl ethanolamine nor phosphatidyl choline was found in the Spirochaeta.

The metabolism of macromolecules during the differentiation of Myxamoebae of the cellular slime mould Dictyostelium discoideum containing different amounts of glycogen.

Abstract: 1. Methods of obtaining myxamoebae of Dictyostelium discoideum strain Ax-2 (ATCC 24397) with glycogen contents in the range 0.05-5mg of glycogen/10(8) cells are described. The changes in cellular glycogen, protein and RNA content during the differentiation of such myxamoebae were determined. 2. Myxamoebal glycogen is not conserved during differentiation and gluconeogenesis may occur even in cells that contain a large amount of glycogen initially. 3. There is a marked net loss of cellular protein and RNA during differentiation and associated with this there are also marked decreases in the sizes of the intracellular pools of amino acids, acid-soluble proteins and pentose-containing materials. 4. During the early stages of development some protein and pentose(s) are excreted, but this cannot account for the decreased cellular content of protein and RNA. 5. There is a linear rate of production of NH(3) during development, and oxidation appears to be the fate of the major portion of the degraded protein and RNA. 6. However, provision of an alternative metabolizable energy source (glycogen) has little effect on the rate or extent of protein or RNA breakdown or on the changes in the sizes of the intracellular pools of amino acids, acid-soluble proteins and pentose-containing materials. 7. It is concluded that during development there is a requirement for the destruction of specific RNA and protein molecules for reasons other than the provision of oxidizable substrates. 8. The kinetic model of Wright et al. (1968) is discussed in relation to these changes in macromolecular content.

Diauxic Growth of Propionibacterium shermanii

Abstract: Propionibacterium shermanii has been anaerobically propagated in batch and continuous culture with glucose and/or lactate as energy source. Specific growth rate on lactate was observed to be the same as that on glucose. In terms of cell density, the yield on glucose is higher than the yield on lactate. But the molar ratio of yield on glucose to that on lactate, 8.35, is in good agreement with the theoretical value of 8. In a mixture of glucose and lactate, P. shermanii showed diauxic growth. It used lactate before glucose utilization began. Neither temporary growth cessation nor two distinct growth phases were observed. A mathematical model is proposed to describe the diauxic growth.

The regulation of naphthalene oxygenase in pseudomonads.

Abstract: SUMMARY: Naphthalene oxygenase was induced in several pseudomonads when these were grown on salicylate as a carbon and energy source, or when salicylate was added to cultures growing on succinate. The enzyme was not induced in Pseudomonas strain NCIB9816 when this was grown in the presence of catechol, although after the addition of this compound to cultures growing on succinate the levels of catechol 1,2-oxygenase and catechol 2,3-oxygenase were similar to those observed after the addition of salicylate. Furthermore, two structural analogues of salicylate, 2-aminobenzoic acid and 2-hydroxybenzyl alcohol, induced naphthalene oxygenase gratuitously. Therefore salicylate is probably the inducer of naphthalene oxygenase.

Microbial degradation of hydrocarbons. Catabolism of 1-phenylalkanes by Nocardia salmonicolor.

Abstract: 1. Nocardia salmonicolor grew on a variety of alkanes, 1-phenylalkanes and 1-cyclo-hexylalkanes as sole carbon and energy sources. 2. Growth on 1-phenyldodecane in batch culture was diauxic. Isocitrate lyase activity was induced during lag phase, reaching a maximum activity in the first growth phase, during which both the aromatic ring and the side chain were degraded. However, 4-phenylbutyrate, 4-phenylbut-3-enoate, 4-phenylbut-2-enoate, 3-phenylpropionate, cinnamate and phenylacetate accumulated in the growth medium. These compounds disappeared at the onset of diauxic lag and four hydroxylated compounds accumulated; one was 4-(o-hydroxyphenyl)but-3-enoate and another was identified as 4-(o-hydroxyphenyl)butyrate. These compounds were utilized during the second growth phase. 3. Washed 1-phenyldodecane-grown cells oxidized acetate, cinnamate, 3,4-dihydroxyphenylacetate, homogentisate, o-, m- and p-hydroxyphenylacetate, phenylacetate, and 4-phenylbutyrate rapidly without lag. 4. Extracts of such cells rapidly oxidized homogentisate,3,4-dihydroxyphenylacetate, catechol and protocatechuate. 5. The organism grew readily on 4-phenylbutyrate, phenylacetate, o-hydroxyphenylacetate, homogentisate and 3,4-dihydroxyphenylacetate as sole carbon energy sources, but growth was slow on cinnamate and 4-phenylbut-3-enoate. 6. When cinnamate and phenylacetate were sole carbon sources for growth, phenylacetate and o-hydroxyphenylacetate respectively were detected in culture supernatants. 4-Phenylbut-3-enoate and 4-phenylbutyrate both yielded a mixture of cinnamate and phenylacetate. 7. It is proposed that 1-phenyldodecane is catabolized by ω-oxidation of the terminal methyl group, side-chain β-oxidation to 4-phenylbutyrate, both β- and α-oxidation to phenylacetic acid, hydroxylation to homogentisate via o-hydroxyphenylacetate and ring cleavage to maleylacetoacetate. Catabolism via 3,4-dihydroxyphenylacetate may also occur. 8. Growth on 1-phenylnonane was also diauxic and cinnamic acid, phenylpropionic acid, benzoic acid and hydroxyphenylpentanoic acid accumulated in the medium. Respirometric data and ring-cleavage enzyme activities showed similar patterns to those obtained after growth on 1-phenyldodecane. The results suggest that the main catabolic routes for 1-phenyldodecane and 1-phenylnonane may converge at cinnamate. 9. Possible reasons for diauxie are discussed.