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The theory of geothermal heat extraction is discussed on the basis of three simple idealized models, that is, (1) single fracture flow, (2) intergranular flow and (3) intergranular vaporization models. Theoretical expressions for the total available specific resource energy per unit area or unit volume are given. These results are illustrated by a number of numerical data which are useful in the assessment of the potential of individual geothermal resources.

A survey covers the amounts of heat recoverable from trash; the merits of burning as opposed to recycling trash; the potential supply of trash as a fuel; methods for using trash directly as a fuel and of producing fuels from refuse (e.g., by pyrolysis); processes for separating the components of trash; and an evaluation of processes already in use.

A brief summary of solar driers is given. A simple shelf type drier is described and test results are outlined. The mathematical model of the multi-shelf type drier is developed and its solution using a digital computer is compared with test results to verify the mathematical formulation. Theoretical values of temperatures and drying rates are presented. Extension of the analysis for the refinement of the shelf type driers is discussed.

Details of heat flow measurements made at Rakha and Narwapahar along the Singhbhum thrust belt (a Precambrian metamorphic belt in the peninsular shield of India) are reported. Temperatures were measured in a number of boreholes and conductivity data were obtained from about 80 core samples. Heat flow was evaluated taking anisotropy in conductivity into account. Heat flow values of 59 mW/m2 and 63 mW/m2 obtained at the above two places agree well with the value of 61 mW/m2 previously reported for Mosabani. From the present observations, the whole Singhbhum thrust belt appears to be characterized by a uniform heat flow of about 61 mW/m2 which is almost the same as the global average but much higher than the mean value quoted for shields. However, the surface heat flow is consistent with the surface radioactivity of the area. A plot of surface heat flow against surface heat generation (from the data on U, Th and K contents of the few samples now available) is well on the heat flow — heat generation line for the eastern United States reported by Roy, Blackwell and Birch (1968), which is considered characteristic of a normal continental heat flow province.

Between 1933 and 1937 Dr. Abbot and his co-workers from the Smithsonian Institution made normal incidence measurements atop Mt. St. Katherine in the Sinai. The observations made at that time indicated a very clean atmosphere prevailed on clear days. Measurements made forty years later with newer instruments and one of the original silver disks used by Dr. Abbot indicates a loss of some 10 per cent of the solar energy contained in the direct beam.

Geothermal waters from the high-temperature areas in Iceland cannot, as a rule, be used directly for space heating or domestic purposes. It is their chemical composition which makes them unsuitable for direct use and the components that are relevant include silica, hydrogen sulphide, carbon dioxide, calcium, and, for three high-temperature areas, too high salinity. In order to exploit the thermal energy from the high-temperature waters for space heating, this energy has to be transferred into fresh ground water by means of heat exchangers. Pilot plant tests and chemical thermodynamic calculations indicate that suitable thermal water for space heating can be produced by mixing steam flashed from high-temperature waters directly with fresh ground water. The fresh water must be heated to 110–130°C so it can be degassed by subsequent flashing to 100°C. The quality of the heated water formed by this method depends on the hydrogen sulphide and carbon dioxide content of the steam and the overall composition of the fresh water. The components in the fresh water that are particularly significant include total carbonate and pH. Fresh water heated directly with steam from the typical non-saline high-temperature hydrogen sulphide bearing waters would be too high in hydrogen sulphide to be suitable for domestic use as suggested by the thermodynamic calculations. Possibly the fresh water could be treated after heating to lower its hydrogen sulphide content to an acceptable level.

A new empirical method has been developed for computing sunshine S from total cloud amount. The equation used is of the form S = 1 − f1 + f2, where f1 and f2 are, respectively, functions of total cloud amount and latitude correction. The results obtained with this equation are compared with observed values and are found to be in good agreement. Tables 1 and 2 present these results. Assuming extreme conditions, the maximum possible deviations of total solar radiation, net radiation and evaporation (or potential evapotranspiration), using the formulae of Reddy[1–4] are discussed for the case where calculated values of S deviate 0·10 from observed values of S. The formula can be usefully employed with considerable accuracy in water and energy budget studies.

Ellipsometric results presented in this paper show that it is possible to grow a uniform Nb oxide film by plasma oxidation, and the index of refraction of this Nb oxide is 2.30. Similarly, in a previous paper we showed that plasma oxidation of Ta produced a uniform Ta oxide film with a refractive index of 2.21. These results are in contrast to the earlier work of Lee et al., who fitted their ellipsometric measurements on the plasma oxidation of Nb and Ta with two‐layer models. It is shown that the Nb and Ta oxides in the work of Lee et al. were not grown to a sufficient thickness to prove definitively that the oxides were composed of two layers, and that their data can be fitted equally well with one‐layer models.

A critical analysis was performed on galvanic cell techniques which employ calcia‐stabilized zirconia electrolytes. The presence of low‐level electron or hole conduction in the ionic conducting range of the electrolyte was found to be responsible for oxygen permeation through the electrolyte which can either oxidize or reduce a single‐phase oxide and, hence, lead to drift in the open‐circuit emf with time. Taking oxygen permeation into account quantitatively, a series of isothermal titration experiments in wüstite was performed in which the cell emf was found to be linear with composition (i.e., oxygen‐iron molal ratio). These results are in excellent agreement with a recent composite analysis of all thermodynamic data in the Fe ‐ O system. Previous cell studies in which deviant behavior has been reported are probably due to improper galvanic cell techniques. No evidence was found to support the existence of more than one‐phase or second‐order transitions within the wüstite phase.

A brief assessment is given of the current position on the relative merits of CdS and silicon solar cells for both space and terrestrial applications. After drawing attention to the absence of any known major stability problem with CdS cells, two other criteria are adopted for comparing the two cells. The first of these is the expected cost of medium-scale production of solar modules for remote and portable terrestrial applications. Details are given of an integrated approach to the CdS module construction which uses current technology but results in significant cost savings. The second criterion is the power-to-weight ratio for space arrays. In both of these cases, CdS cells are shown to possess significant potential advantages.

Thermal oxidation of silicon, in the presence of chlorine or bromine compounds, effectively improved the dielectric breakdown characteristics (as measured with a voltage ramp) of the resulting SiO 2 films. At high halogen concentrations the oxidation rate was erratic; the optimal initial breakdown properties were attained by oxidizing with about one‐half of the halogen‐containing additive that would cause etching of the Si. Oxidation in the presence of halides increased the resistance of SiO 2 films to dielectric breakdown under accelerated bias‐temperature stressing. The maximum time to failure varied semilogarithmically with HCl concentration and increased by 0.3 to 0.65 decade per per cent of HCl (0–3% HCl range) for applied fields from 2 to 7 MV/cm, respectively. Higher oxidation temperatures further improved the resistance of HCl oxides to dielectric wear‐out. The longer wear‐out times were attributed to hydrogen rather than the halogen and could be achieved by oxidation in small concentrations of H 2 O , annealing in H2, or.implantation of H2 or H 2 O .

As a result of the energy conversion and storage research underway at Oklahoma State University since 1961, several components needed to engineer a continuous-duty energy system operating on replenishable solar energy have been developed to the prototype stage and are being tested. This paper presents and discusses these components and how they fit together in the solar energy systems envisioned for the long-term and immediate future. A simplified economic analysis of solar energy systems is presented, and the calculated generation costs are compared with those of conventional fuel burning systems for different fuel costs, load factors and interest rates. One result of this study is that wind energy systems, costing $125 to $150 per installed kW and pumping power directly into a.c. mains for 20 per cent of the time using the field-modulated generating systems developed at OSU, are competitive with conventional systems costing $250 to $350 per installed kW operating at a load factor of 80 per cent and fuel cost of $0·50 per MBtu. More such comparisons are included in the text of the paper.

A new computational method is presented which calculates geothermal heat flow values and geothermal gradients with more precision than permitted by previously published techniques. The data required are: geothermal temperature at a known depth, mean surface temperature, the rock types in the stratigraphic column and the thermal resistivity values for the different types of rocks. This method is valuable in areas that have no measured gradient values. Basic equation used was the Fourier heat transfer equation Q/A = −1/ρi (∂T/∂x) where Q/A is heat flux in μcal/(cm2 s), ρi is thermal resistivity (°C s cm/μcal) and ∂T/∂x is the x component of the temperature gradient (°C/cm). The thermal resistivity was allowed to vary linearly with temperature ρi = ρio [1 + Ki (T − 30)] where ρi is thermal resistivity of the lithographic segment «ia at a temperature T, ρio is thermal resistivity at 30°C and Ki is the temperature coefficient of thermal resistivity. The procedure consisted of integrating the combined equation for heat flux in terms of temperature dependent resistivity. Two iterative solutions were used to simplify the calculations: exact and approximate. The heat flux for each well was assumed to be 1.0 HFU and segmental temperatures were calculated from the bottom (arbitrarily) up, until a surface temperature was obtained. The calculated surface temperature could then be compared with the mean surface temperature (MST). Correction in the heat flux value was made until the calculated surface temperature and MST agreed. An analysis of three deep Appalachian test wells was made and the results showed the critical importance of lithographic ordering and the temperature dependence of thermal resistivity upon calculated geothermal quantities.

A serious obstacle to the large-scale terrestrial application of solar energy lies in the scarcity of reliable data on the amount of solar energy at candidate converter sites. This paper describes a system designed to monitor and record, automatically, the values of the direct and total (sun and sky) solar radiation which would be seen by either tracking or fixed-type solar converters. A further pressing need addressed by the system is the means for efficiency testing and evaluation of solar cells, solar collectors and solar concentrator systems, under outdoor exposure to natural sunlight and weather conditions for extended periods. The design was accomplished in support of the Marshall Space Flight Center, NASA, where design concepts and materials for large-scale terrestrial solar energy converters are currently being evaluated.

The paper was motivated by the need to extend the utility of a solar water heating system by adjusting a heat exchanger in the hot water tank. An approximate dynamic model, composed of two linear differential equations, is used in an attempt to describe the transient performance of the system. This model is digitized in time, the result being in the form of a set of finite difference equations. Using experimental data the parameters of the model are identified by linear regression. These parameters are computed for various flow rates of the feed water through the heat exchanger in order to obtain a global representation of the system. The theoretical results were tested by simulation and were proved to be sufficiently close to the experimental ones.

Deployable solar arrays are required to meet the rising demands of electrical energy for space missions. The existing schemes for deployable solar arrays are briefly presented. One of the critical components of a deployable solar array system is the actuator boom. It provides extension and retraction capabilities to the system and acts as the prime structural member of the system. The characteristics of actuator booms have been identified in order to enable designers to make a judicious choice for their systems. Initial steps for preliminary design are outlined.

The sodium (Na), potassium (K), calcium (Ca) geothermometer is discussed as a tool for locating and evaluating areas prospectively valuable for geothermal development. Presented is a regional analysis of the major thermal springs of Utah to demonstrate the use of the Na-K-Ca geothermometer as a rapid and meaningful method of geothermal reconnaissance. Of the thermal areas of Utah, Roosevelt Hot Springs show the greatest geothermal potential where estimated temperatures are nearly 300 °C. This compares favorably with estimated and measured temperatures from proven geothermal fields such as Cerro Prieto in Mexico and the Salton Sea field of California. Also presented are more detailed studies of LaVerkin Ho1 Springs and Wilson Hot Springs, Utah, and the Mesa anomaly, Imperial Valley, California. These studies examine the accuracy and precision of the Na-K-Ca geothermometer and the physical conditions under which it can be reliably used to predict subsurface temperatures. It is shown that in the saline environment of the Imperial Valley, it should be possible to obtain useful information even though the results might normally be considered suspect due to concentration or dilution of the analyzed samples.

One of the methods of generating geothermal power is to use a suitable working fluid which extracts heat from geothermal fluids and generates power in a closed cycle. This paper presents a discussion of an improvement of the basic closed cycle with isobutane as a working fluid. A regenerative heat exchanger is added for heating the cold condensate of isobutane with the highly superheated exhaust. The addition of this heat exchanger can result in a significant reduction in the size of heat rejection equipment. Furthermore, the waste brine of the improved system is at such a high temperature that the waste heat can be economically utilized for desalting water for industrial uses.

In this work some results are given referring to laboratory experiments carried out on clay samples in the ranges 1 · 10−2 − 5 · 103 Hz and 20° − 100°C. The diagrams of conductivity, permittivity and loss-tangent have been obtained, and certain anomalies can be recognized in them.

Oxygen, silicon, and hydrogen ions are implanted with doses of 10 10 − 10 15 / cm 2 through the oxide of a MOS structure. The development of induced levels in Si can be observed. Annealing experiments from room temperature to 800°C show the transition from the nonequilibrium incorporation to the initial (nonimplanted) state. Hydrogen implantation hinders the restoration of a Si ‐ SiO 2 interface under H2 annealing.

In this paper a brief review is given of the dependence of the oxygen isotopic fractionation of the sulfate ions-water system on temperature and the pH. From the available experimental data some relationships have been elaborated, which show that the isotopic exchange time is strongly temperature and pH dependent. The times for 97 per cent of isotopic exchange (near equilibrium conditions) at pH 7.0 are about 9 years at 200°C and 0.6 years at 330°C, while at pH 3.8 and at the same temperatures the times of exchange are 1.5 years and 0.08 years respectively. Thus, at the temperatures and pH of geothermal reservoirs the sulfate could be in isotopic equilibrium with environmental water, and the oxygen isotopic fractionation factors of sulfate-water geothermal pairs, being temperature dependent, can be used as geothermometers. Also reported here are some results on the O18 content of sulfate-water pairs from some wells on the edge of and outside the Larderello geothermal basin. The estimated isotopic temperatures are not very significant for the deep reservoir temperatures due to the geological features of the Larderello area which show important outcropping and deep anhydrite layers. Furthermore, as regards the wells outside the Larderello basin (Travale wells) some mixing of the geothermal water with colder underground water has been proved. However, the isotopic temperatures are generally higher than those measured at the well-head, and the highest ones are close to those estimated for the geothermal reservoir. In other geothermal areas more convenient from a geological point of view, the O18 content of the sulfate-water pair can be a useful and accurate thermometer. The O18/O16 ratios of several other sulfates (surface and deep anhydrite samples, sulfate ions in thermal springs) from the same area were also determined and differ substantially from borehole sulfate values.

The effect of pH and added anions such as phosphate, acetate, chloride, or sulfate in perchlorate solutions on the anodic deposition of ferric oxy‐hydroxide films on platinum was studied. In all cases deposition took place by the oxidation of a ferrous species to a ferric film with 100% current efficiency. The growth rate of the film was dependent on the concentration of FeOH + ion which was the depositing species in a ferrous perchlorate solution and in the solutions containing acetate, chloride, or sulfate. In the solution contain‐ing phosphate, the anodic deposition proceeded by the simultaneous oxidation of FeOH + and FeH 2 PO 4 + ions to γ ‐ FeOOH and FePO 4 · 2 H 2 O .

Fifteen new heat-flow measurements are reported, fourteen of which are located in or near a fracture zone near 43°N on the mid-Atlantic Ridge. These data, combined with earlier nearby measurements, show the fracture zone to have an observable, positive effect on the regional heat-flow field. A good correlation is observed between large near-bottom water potential temperature gradients and the occurrence of significant variations with depth in the measured rate of heat-flow. One measurement was taken in the Horseshoe abyssal plain west of Gibraltar and gave a value of 1.38 μcal/cm2s.

The theoretical high-energy dosimetry program, developed over the past decade in the Health Physics Division of the Oak Ridge National Laboratory, is described briefly. Some selected results are presented to illustrate the calculational capabilities that exist. These examples include depth-dose curves for broad, parallel beams of 2 GeV protons and 1 GeV neutrons incident laterally on a tissue slab and $sup 11$C activation calculated as a function of depth in a water phantom exposed to a beam of 400 MeV neutrons. Because of their planned use in cancer radiotherapy research, pions are under extensive study. The Monte Carlo computer code, PION-I was developed to calculate the penetration of pions in materials (containing H, C, N, and O) exposed to pion beams. Good agreement is found between calculated and measured curves in water. Calculated L.E.T. distributions at various depths are shown. The pattern of energy deposition around pion capture sites is analyzed. T-I kidney cell survival levels are predicted for pion beams based on data of Todd and on the survival model of Katz. (FR)

Pour mesurer une charge pulmonaire en 239 Pu, emetteur de raies X de tres basses energies, il a ete propose une methode consistant en l’administration au sujet contamine d’un aerosol de 233 Pa. En effet, le 233 Pa, de courte periode, emet, outre les memes raies X que le 238 Pu, un photon y ayant une energie de 310 keV, qui permet de mesurer la charge administree.Pour la mesure des basses energies, les possibilites des detecteurs a scintillation et d’un compteur proportionnel ont ete comparees a partir de mesures effectuees sur un fantome anthropomorphe equivalent-tissu. Le compteur proportionnel permet la mesure des raies X et l’utilisation du 233 Pa comme simulateur du 239 Pu.

L’article traite des effets biologiques des rayonnements chez les individus irradies et chez les descendants de ces individus.Chez les individus irradies, la relation dose-effet est lineaire seulement si le debit de dose presente une valeur tres elevee correspondant a la saturation du processus de restauration. Dans les autres cas, cette relation est representee par une sigmoide, qui s’ecarte d’autant plus de la droite precedente que la duree de l’irradiation est grande. Les expressions mathematiques traduisant le passage de la droite a la sigmoide sont donnees. Leur application montre que l’irradiation continue des populations au rythme du debit de dose maximal admissible de 500 millirems par an delivre a l’ensemble du corps (gonades exceptees) provoquerait moins d’une leucemie par an dans le monde entier.L’etude des effets chez les descendants des individus irradies est basee sur l’extrapolation des resultats experimentaux obtenus sur des animaux appartenant a des especes classees a des niveaux differents dans l’echelle de l’evolution. Les insectes sont pris comme exemple parmi les especes les moins evoluees : ils sont tres resistants a une irradiation instantanee de plusieurs centaines de milliers de rems, mais l’irradiation de generations successives conduit a un cumul progressif de genes mutes ou d’aberrations chromosomiques, qui se manifeste par l’apparition d’une proportion de plus en plus grande de dommages chez les descendants. La souris, plus evoluee que les insectes, presente des caracteristiques inverses : elle est moins resistante a une irradiation instantanee, mais le cumul ci-dessus mentionne est chez elle beaucoup moins apparent. L’explication serait donnee par le nombre minimal de genes mutes dont l’action combinee est necessaire pour faire apparaitre le dommage. Le calcul montre que ce nombre serait de deux chez la souris, alors qu’un seul gene suffit chez les insectes. Si l’on adopte pour l’homme un degre de polygenie superieur, soit un nombre d’au moins quatre genes comme les recentes decouvertes sur les maladies hereditaires l’ont mis en evidence, l’irradiation des generations successives de Francais au rythme du debit de dose maximal admissible pour les gonades de 170 millirems par an n’engendrerait l’apparition d’aucun dommage avant 600 ans.Sans admettre de seuils d’action des rayonnements, l’etude demontre donc une absence pratique de dommages si les normes actuelles de radioprotection sont respectees.

A comparison was made of the theoretical and experimental profiles of heavy ions tracks in nuclear emulsions. The experiments were conducted with ions (charge interval [math] and velocity interval [math],8) whose track profiles were measured by means of two photometers with rectangular slits. The theoretical calculations used Katz’s theory on energy distribution around the track and transmittance of direct and diffused light by Ag-Br grains. There was a very good agreement between theoretical and experimental data, and a single quantity could be used to characterize an emulsion stack response. An examination of the experimental data obtained by other investigators showed that the theory also applied to ions with Z > 26.

(1974). Cars, Fuel, and Pollution. Environment: Science and Policy for Sustainable Development: Vol. 16, Special Issue on Handling the Oil Surplus, pp. 15-27.

In order to assess the geothermal resources of the hot springs located in different tectonic regions of India, preliminary geophysical, geochemical and tritium studies were undertaken in Puga valley (Ladakh), Ratnagiri and Kolaba Districts (West Coast) and Bhimbandh (Bihar) areas. The studies indicate that out of the three areas investigated, the Puga valley is the most promising because of its higher geothermal gradient, association of spring waters with magmatic components, its higher estimated reservoir temperature ( ≥ 200° C ) and probable larger available supply of groundwater.

A seismic noise survey at Solfatara Crater, Phlegraean Fields, was carried out during March 1973 using a portable tape seismograph. The shape of the spectra and the maximum amplitude values of the ground velocity point out that the seismic noise is strongly influenced by the surface thermal activity and mechanical properties of outcropping rocks.

An extensive analysis of solar heating and dwellings in eight cities in the U.S.A. has been completed by the authors and recently published. The design of the solar heating system was optimized in each location, and the cost of solar heat was determined. The mathematical model of these systems has now been modified to include heat-operated absorption cooling units of the aqueous lithium bromide type. Approximately one hundred analyses of hourly cooling (and heating) performance for a full year in these locations have been made. Designs have been reoptimized to minimize total annual energy costs for house cooling and heating and for hot water supply. The combined system has been found more economical than heating alone in most locations, and some locations unattractive for solar heating have become candidates for the combination. The paper contains a description of the method of computation and the results of the design and cost analyses.