Introduction The use of electrical well logs for the quantitative determination of suchreservoir parameters as connate water saturation, formation permeability andconnate water salinity has recently been attracting the attention of a numberof workers. While the theory of the determination of connate water salinity from theself potential S.P. log has received rather detailed treatment, relativelylittle attention has been paid to the theoretical aspects involved in thequantitative interpretation of resistivity data. It is clear that if electricalwell logs can be used for the quantitative evaluation of physicalcharacteristics of reservoir rock, they will provide a valuable tool tosupplement cheaply information obtained by more laborious core analysis. Incertain cases it is conceivable that the coring program could be considerablycurtailed if the electric log could be relied upon to give reasonably accuratequantitative information. It is our object in this paper to examine the theoretical basis ofquantitative log interpretation as expressed in such well-established loggingconcepts as formation factor and cementation factor. It is also our object toinvestigate the physical aspects of the relationship which is presumed to existbetween resistivity index and brine saturation in reservoir rock. Inparticular, we will endeavor to draw attention to the fact that it is possibleto express these logging concepts in terms of capillary pressure-saturationrelationships, permeability and tortuosity parameters which we will consider inthis paper to be fundamentally indicative of rock texture. The probability ofbeing able to obtain from log recordings alone the data theoretically essentialto permit quantitative log interpretation will be examined, and considerationwill also be given to the problem of formulating simple semiempiricalrelationships for use in the field. Theoretical Considerations The concept of formation resistivity factor, or as it is now commonlycalled, formation factor, appears to have been introduced by G. E. Archie.Formation resistivity factor as defined by Archie is the resistivity of a rock100 per cent brine-saturated divided by the resistivity of the brine. Thisrelationship had previously been used by physical chemists and the concept is, for example, implicit in an early treatment by Fricke of the conductivity of aqueous slurries. T.P. 2852

Ventilation standards, health, and indoor air quality have not been adequately examined for residential weatherization. This randomized trial showed how ASHRAE 62-1989 (n=39 houses) and ASHRAE 62.2-2010 (n=42 houses) influenced ventilation rates, moisture balance, indoor air quality, and self-reported physical and mental health outcomes. Average total airflow was nearly twice as high for ASHRAE 62.2-2010 (79 vs. 39 cfm). Volatile organic compounds, formaldehyde and carbon dioxide were all significantly reduced for the newer standard and first-floor radon was marginally lower, but for the older standard, only formaldehyde significantly decreased. Humidity in the ASHRAE 62.2-2010 group was only about half that of the ASHRAE 62-1989 group using the moisture balance metric. Radon was higher in the basement but lower on the first floor for ASHRAE 62.2-2010. Children in each group had fewer headaches, eczema, and skin allergies after weatherization and adults had improvements in psychological distress. Indoor air quality and health improve when weatherization is accompanied by an ASHRAE residential ventilation standard, and the 2010 ASHRAE standard has greater improvements in certain outcomes compared to the 1989 standard. Weatherization, home repair, and energy conservation projects should use the newer ASHRAE standard to improve indoor air quality and health.

We present a new method for high-resolution nanoscale magnetic resonance imaging (nano-MRI) that combines the high spin sensitivity of nanowire-based magnetic resonance detection with high-spectralresolution nuclear magnetic resonance (NMR) spectroscopy. Using a new method that incorporates average Hamiltonian theory into optimal control pulse engineering, we demonstrate NMR pulses that achieve high-fidelity quantum control of nuclear spins in nanometer-scale ensembles. We apply this capability to perform dynamical decoupling experiments that achieve a factor of 500 reduction of the proton-spin resonance linewidth in a ð50-nmÞ 3 volume of polystyrene. We make use of the enhanced spin coherence times to perform Fourier-transform imaging of proton spins with a one-dimensional slice thickness below 2 nm.

Improved apparatus, methods, and experimental techniques for dete,mining the capillary pressure-saturation relation are described in detaiL In this connection a new multi-core procedure has been developed which simplifies the experimental work in the study of relatively homogeneous reservoirs_ The basic theory concerning the Leverett capillary pressure function has been extended and has been given some practical application_ Some discussion is presented to indicate the relationship of relative permeability to capillary pressure, and to provide a new description of capillary pressure phenomena by introducing the concept of the psi function.

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