ALBERT

Description / Table of Contents: CONTENTS: Preface. - Introduction. - Principle of the IR scanner. - Advantages of mobile infrared thermography. - Discussion of field measurements. - Recommendations for future work on thermography of buildings. - Other potential applications of infrared thermography of buildings. - Appendix A: Thermograms of northern exposure of USA CRREL building. - Appendix B: Sample thermograms of heat loss survey at Pease Air Force Base. -Appendix C: Sample thermograms of heat loss survey at Dartmouth College. - Abstract.

Description / Table of Contents: A method to assess quickly the insulation effectiveness of buildings using mobile infrared thermography has been developed at USA CRREL. In contrast to the infrared thermography done in Sweden, this method concentrates on obtaining useful data by measuring the outside surface temperature of structures. This report outlines the basic principles involved in these measurements, and discusses field measurements and the inherent advantages of infrared thermography. Typical thermograms are presented in the appendixes.

Description / Table of Contents: A 4-summer hydrologic record from a 1.6 km^2 drainage basin at Barrow, Alaska is analyzed. The watershed, a drained lake basin, is underlain by continuous permafrost within 0.3m of the tundra surface and is covered by ice-wedge polygons and numerous small shallow ponds. Considerable variations from the 20-yr means of summer climate (thaw period 88 days, precipitation 67 mm) are represented in the data: 1963 - cold, extremely wet; 1964 - cold, extremely dry; 1965 - cool, dry; 1966 - cool, wet. Runoff varied greatly from storm to storm, occurring primarily through and over the tundra mat and through an intricate system of polygonal troughs and ponds. As a result of the subdued coastal topography, varying areas (0.3 km^2 to 1.6 km^2) contribute to runoff from different storms. Analyses of hydrographs revealed: 1) lag times generally from 3 to 10 hr; 2) recession constants of about 50 hr, but occasionally as much as 160 hr; and 3) runoff from individual storms between 1 and 70%. About 5% of the thaw season precipitation normally runs off. Comparison of total thaw season precipitation between the U.S. Weather Bureau and a shielded gage located on the watershed indicated no major differences. If "trace" precipitation is considered, only 90% of the actual precipitation may be recorded. Pan evaporation for an average thaw season is about 160 mm and evapotranspiration which is essentially in balance with precipitation is about 60 mm. Conductivity of runoff water varied from 250 [My]mhos during sustained discharge to more than 500 [My]mhos during low flows in dry years. Precipitation chemistry showed no correlation with storm direction. Assuming all winter precipitation runs off, and the data are spatially and temporally representative, about 50% of the measured annual precipitation in this region runs off into the Arctic Ocean.

Description / Table of Contents: CONTENTS: Preface. - Abstract. - Introduction. - Theory. - Discussion. - Conclusion. - Literature cited.

Description / Table of Contents: A diffusion equation is obtained that describes the mechanical dispersion of a dilute mixture of solid particles within an ice matrix that is undergoing deformation. It is shown that within the limits of time intervals and strain rates appropriate to the movement of glaciers and ice sheets the dispersal distance usually is no larger than a distance about one order of magnitude greater than the size of the particles themselves.

Description / Table of Contents: CONTENTS: Preface. - Abstract. - Introduction. - Theoretical considerations. - Method of canopy evaluation. - Application to forest problems. - Forest blowdown. - Radioactivity gradient. - Phenology. - Forest types and structure. - Distribution of leaves and canopy gaps. - Light quality. - Discussion and summary. - Literature cited.

Description / Table of Contents: A technique for evaluating forest canopies was developed based on the use of a divergent lens system to obtain hemispherical photographs of tree crowns. The photography was processed from 35 mm film and enlarged as a silhouette, and the light transmission was measured with a specially fabricated macrodensitometer. It is concluded that the amount of forest canopy can be expressed as canopy closure index (CCI) at a precision of approximately 5%. It is shown by application to a variety of problems in diverse geographical areas that this technique can be used for measuring both temporal and spatial changes in the canopy, for estimating the shade light climate, and for specifying the probability of target detection through a canopy. Data are presented to analyze changes caused by explosions, radioactivity, growing season, and vegetation types. The geometry of gaps in tree crowns is discussed and the nature of shade light quality under forests is illustrated.

Description / Table of Contents: CONTENTS: Preface. - Abstract. - Introduction. - Theory. - Application to ice sheets and ice shelves. - Summary. - Literature cited.

Description / Table of Contents: An analysis is made of the rate of bubble coalescence in a deforming ice mass. A total strain of at least 8 is required before appreciable coalescence occurs, The analysis has.been applied to deforming ice shelves and ice sheets. No appreciable coalescence is expected in ice shelves but coalescence should occur in ice sheets (or glaciers) if the shear strain rate at the bottom surface is of the order of 0.075/yr or larger. Measurements of bubble concentration are capable of setting limits on paleo-strain rates of the present ice sheets. Bubble migration down temperature gradients presents complications to the study of bubble coalescence.

Description / Table of Contents: CONTENTS: Preface. - Abstract. - Introduction. - Analytical procedures. - Results and discussion. - Bubbles in ice. - Conclusions. - Literature cited.

Description / Table of Contents: Application of the gas law to fourth-place density measurements of ice samples from two deep drill holes at Byrd Station and Little America V, Antarctica, shows that virtually all density increase beyond the pore close-off density (0.830 g/cm^3) can be attributed to compression of the entrapped bubbles of air. Data from Byrd Station also indicate that the lag between overburden pressure and bubble pressure, initially 4-5 kg/cm^2 at pore close-off, diminishes to less than 1.0 kg/cm^2 at about 200-m depth. By substituting the overburden pressure for the bubble pressure in the pressure-density relationship based on the gas law, ice densities below 200 m can be calculated more accurately than they can be measured per se on cores because of the relaxation that occurs in samples recovered from high confining pressures. This relaxation, resulting in a progressive increase in the bulk volume of the ice with time, is generally attributed to decompression of the entrapped air bubbles following removal of the ice from high confining pressures. However, calculations of the stress in ice due to bubble pressure, together with measurements of bubble sizes in cores from various depths at Byrd Station, both tend to indicate that there has'been negligible decompression of the inclosed bubbles. It is suggested that most of this relaxation may be due to the formation of microcracks in the ice. Anomalous bubble pressure-density relations at Little America V tend to confirm abundant stratigraphic evidence of the existence of considerable deformation in the upper part of the Ross Ice Shelf. Studies of crystal-bubble relations at Byrd Station revealed that the concentration of bubbles in ice remains remarkably constant at approximately 220 bubbles per cm^3. Bubbles and crystals were found to be present in approximately equal numbers at pore close-off at 64-m depth, at which level the average bubble diameter was 0.95 mm, decreasing to 0.49 mm at 116 m and to 0.33 mm at 279 m. Despite a tenfold increase in the size of crystals between 64 and 279 m, the bubbles showed no tendency to migrate to grain boundaries during recrystallization of the ice. The observation that most of the bubbles had assumed substantially spherical shapes by 120-m depth points to essentially hydrostatic conditions in the upper layers of the ice sheet at Byrd Station.

Description / Table of Contents: The attenuation of visible light by falling snow was studied by making simultaneous attenuation measurements and snow concentration measurements. The attenuation coefficient was calculated from photometric measurements and from visual observations. Snow concentration in the air was evaluated by two methods: from Formvar replicas collected during the snowfall, and by mass accumulation of snow in collecting pans. The snowflakes were arbitrarily classified by crystal types according to their estimated fall velocity. It was found that the correlation between extinction coefficient (attenuation) and snow concentration was generally much higher by types than when all snowflakes were considered together regardless of crystal components and degree of riming. Two types, apparently improperly classified, displayed lower correlations than the overall group. When no fog is present during the snowfall, the experimental results coincide well with attenuation theory if a reasonable correction is applied to the values obtained in the measurement of snowflake diameters. Measurements of mass flux indicate that for a given intensity the attenuation caused by snow is an order of magnitude greater than that caused by the same mass flux of rain.

Description / Table of Contents: CONTENTS: Preface. - Abstract. - Introduction. - Previous work on unsteady rectilinear motion of a sphere. - Experiments with a circular path. - Conclusion. - Literature cited. - Appendix A: Comparisons of the measured and calculated forces.

Description / Table of Contents: Forces on a sphere moving unsteadily along a circular path in a viscous fluid are measured, and it is found that within the experimental range the formula valid for rectilinear motion has to be modified to account for the curvature of the path.

Description / Table of Contents: Table des matières: Introduction. - Observation météorologique. - Pression atmosphérique. - Température de l'air. - Température sur le sol. - Température du sol: 1° à 0,4 m., 2° à 0,8 m. et 3° à 1,6 m. de profondeur. - Humidité de l'air. - Direction et vitesse du vent. - Nébulosité, forme et direction des nuages, hydrométéores. Eau tombée. - Evaporation de l'eau douce. - Température sur le sol et à 6 cm. de profondeur. - Température de l'eau de la rivière. - Remarque diverses; couches des nuages à hauteur différente. - Observations météorologiques de l'année 1883-84 faites à Sodankylä. - Remarques diverses 1883-84. - Observations météorologiques faites à Kultala. - Remarques diverses. - Aperçu général de moyennes mensuelles et de variations diurnes: variation de la pression atmosphérique, de la température de l'air, de la température sur le sol, de l'humidité de l'air, de la vitesse du vent, de la nébulosité et de l'eau tombée. - Fréquence des vents. - Les années 1882 - 83 et 1883 - 84 au point de vue météorologique.

Description / Table of Contents: Content: Aurores boreales / par Carlheim-Gyllenskiöld. - Électricité atmosphérique / par S. A. Andrée. - Phénomènes optiques de l'atmosphère, avec quelques remarques sur les Étoiles filantes, le spectre des Copépodes, l'accroissement des brins d'orge / par Carlheim-Gyllenskiöld. - Recherches sur le prétendu changement de la couleur de la peau après un hivernage dans les régions polaires / exécutées par R. Gyllencreutz, communiquées par Frithiof Holmgren.

Description / Table of Contents: The compressibility of wet snow is described in terms of pressure melting and nonlinear viscous deformation at grain contacts. The results of experiments with different salinities and liquid water contents are compared with computed densities. The decreasing compressibility of wet snow with increasing salinity and decreasing liquid content is quantified and explained. Simultaneous particle growth and the doubly charged layer at phase boundaries are included in the model. The results show that the density of wet snow increases approximately as a power of time but is highly dependent on the stress, initial particle size, liquid water content, and ionic impurity content of the snow.

Description / Table of Contents: The objectives of this investigation were to describe channel characteristics and geographic settings of ice jam sites from aerial photographic interpretation, to indicate which characteristics may be important in causing ice jams, and to suggest additional uses of aerial photographs. Aerial photographs were taken of 19 sites with a Zeiss RMK 15/23 aerial camera on 17, 19, and 21 April 1976. Uncontrolled photomosaics of each site were assembled and major river characteristics were delineated on the photomosaics. Characteristics described include: manmade structures, falls, rapids, changes in channel depths, channel islands, mid-channel shoals or bars, river bed material, river sinuosity, meanders, floodplain width, riparian vegetation, and types of development on the floodplain. River channel widths were measured from the photographs along rivers where ground truth data were available for comparison. Lengths of channel riffles and pools were measured along the rivers where variations in river depths were evident on the photographs. Seventy-nine percent of the sites have some form of flow control structure which causes a pool with a backwater condition of low velocity. The low flow condition in the pool allows a solid ice cover to form which impedes ice movement and initiates ice jams. Aerial photographs provide a regional perspective for evaluating channel characteristics at an ice jam site and for analyzing the geographic setting at each site during ice-free conditions. Photographs taken after ice jams have formed are useful in monitoring ice jam formation, in analyzing ice characteristics, and in documenting ice jam breakup and movement.

Description / Table of Contents: This study investigates the possibility of providing estimates of the time of occurrence and length of the freezing season for any location in East and West Germany by using the average Januavy air temperature (AJ AT) as an index. The results indicate that reliable values of the mean freezing index can be obtained from the AJAT relationships which are developed for Germany. This association is further verified using data from the northeastern part of the U.S., and the AJ AT is then used to determine the average starting and ending dates (and hence the probable length) of the freezing season for stations in Germany. The AJ AT and the average dates of snowfall occurrence for numerous locations in the U.S. and Germany are also correlated. Interrelationships between these parameters and the average number of days with snow on the ground for stations up to 3000 m in elevation in Germany are examined. A detailed AJ AT map for East and West Germany, in which data from 134 stations, latitude, altitude and regional influences are considered, is developed in order to make the relationships usable. A historical review of the literature on snow studies in Germany and a brief discussion of snow-cover interpretation by satellite photography are included

Description / Table of Contents: The primary objective of this project was to demonstrate the utility of remote sensing techniques as an operational tool in the acquisition of data required by the U.S. Army Corps of Engineers, Seattle District, in the Grays Harbor dredging effects project, and related projects. Aerial imagery was used to map surface circulation and suspended sediment patterns near the hopper dredge pump site at the harbor entrance and near pulpmill outfalls in Aberdeen, and to map the areal distribution and extent of intertidal habitats. The surface circulation maps prepared from the aerial photographs and thermal imagery compared favorably with the large-scale circulation patterns observed in the Grays Harbor hydraulic model at the U.S. Army Engineer Waterways Experiment Station. Of the imagery provided by NASA, the thermal imagery was more useful than the color or color infrared (CIR) photographs for mapping circula­tion, while the CIR photographs were more useful than the thermal imagery or the color photographs for mapping intertidal habitats. Current velocities estimated from dye dispersion patterns and drifting dye drogues were comparable at some locations to velocities measured by in situ current meters and in the hydraulic model. Based on a cursory evaluation of LANDSAT-1 imagery acquired in January, February, and October 1973, it had limited utility in providing data on surface circulation patterns in Grays Harbor. The areal distribution and extent of nine wetland vegetation types, dune vegetation, and three types of eelgrass were mapped using primarily aerial C IR photographs and ground sur­veys. Color photographs were also used for areas not covered by the C IR photographs. Wetland vegetation types mapped were: low silty marsh, low sandy marsh, sedge marsh, high immature marsh, high mature marsh, salt marsh, diked pasture, freshwater marsh, and wooded swamp. Undiked salt marsh (first five types) covered 5540 acres (22.3 km2) in Grays Harbor.

Description / Table of Contents: Road test sections of membrane-enveloped silt and clay soils overlain with asphalt cement concrete were subjected to repetitive dynamic plate-bearing loadings to determine their strength variations during freeze-thaw cycles. The recoverable surface deformations in the load deflection bowl were continuously measured during the loading cycles and analyzed using the Chevron layered elastic computer program to obtain the in situ resilient deformation modulus of the various section layers at different stages of the freeze-thaw cycles. The resilient stiffness of the pavement system (the total load per unit of resilient load plate deflection) was also calculated for the various freeze-thaw conditions. The modulus values of the asphalt cement concrete varied inversely with its temperature by an order of magnetide (90,000 psi to 1,300,000 psi). The resilient stiffness of the pavement system varied in the same manner by nearly a factor of eight (228.4 kips/in. to 1740.2 kips/in.). Despite the wide strength variations of the sections during freeze-thaw cycles, membrane-enveloped fine-grained soils can be utilized instead of granular materials as base and subbase layers in flexible pavements in cold regions where moisture migration is a major concern. Moisture migration did not occur at saturation levels up to 75%, thus there was no strength loss during thawing.

Description / Table of Contents: Field observations of the growth fabrics of the fast and near-fast ice along the coasts of the Beaufort and Chukchi Seas show that, at depths of more than 60 cm below the upper ice surface, the sea ice crystals show striking alignments within the horizontal plane. At one site this alignment was well developed at a depth of 15 cm and in all cases the degree of preferred orientation increased with depth, with the strongest orientations occurring at the bottom of the ice sheet. In general the c-axes of the crystals were aligned roughly E-W parallel to the coast. In the vicinity of islands the alignment roughly paralleled the outlines of the islands and in narrow passes between islands the alignment paralleled the channel. Our observations, as well as similar observations made in the Kara Sea by Cherepanov, can be explained if it is assumed that the c-axes of the crystals are aligned parallel to the 'long-term' current direction at the sea ice/sea water interface. The alignments are believed to be the result of geometric selection among the growing crystals, with the most favored orientation being that in which the current flows normal to the (0001) plates of ice that make up the dendritic ice/water interface characteristics of sea ice. It is hypothesized that current flow in this direction reduces the thickness of the solute boundary layer as well as the salinity in the liquid at the interface. This lowered salinity allows crystals in the favored orientation to extend farther into the melt than neighboring crystals with less favored orientations. In addition the current tends to induce a continuous flux of supercooled seawater against the sides of the crystals that extend ahead of the interface.

Description / Table of Contents: The viscoelastic deflection of an infinite floating ice plate subjected to a circular load was solved, assuming the Maxwell-Voigt type four-element model. An effective method of numerical integration of the solution integrals was developed, of which each integrand contains a product of Bessel functions extending to infinity. The theoretical curve was fitted to the field data, but the material constants thus found varied with time and location.

Description / Table of Contents: An experimental study of forced convective heat transfer over a vertical melting plate has been conducted. This study covers water velocities ranging from 1.7 to 9.8 mm/s and bulk water temperatures from 1.11 to 7.50 C. The experimental results are correlated in terms of Nusselt, Prandtl and Reynolds numbers with a moderate correlation coefficient of 0.843. The results are expected to be useful in predicting the heat transfer characteristics of a much larger prototype ice-water heat sink.

Description / Table of Contents: Results of measurements of salinity, grain size, substructure dimensions and crystal fabrics of the undeformed 2.15-m-thick annual sea ice sheet near Narwhal Island, Alaska, are presented. A notable observation was the formation of a dominant c-axis horizontal structure in all ice below 14 cm, including transformation to a pronounced east-west alignment of the c-axes by a depth of 66 cm. This study confirms earlier reports of the occurrence of very strong horizontal c-axis alignments in arctic fast ice.

Description / Table of Contents: The spectral reflectance of natural snow in the range of 0.20- to about 0.40-micrometers wavelengths was studied in the laboratory using both continuous spectral scanning and fixed bandpass measurements. White barium sulfate pressed powder was used as a standard for comparison. The reflectance of fresh snow was found to be very high (usually nearly 100%) and only weakly wavelength dependent from 0.24 micrometers to the visible range. In the 0.20- to 0.24-micrometers portion of the spectrum, the reflectance was found to be quite erratic. Possible reasons for the irregularities in reflectance measurements are discussed.

Description / Table of Contents: A brief discussion is given of the ways an icebreaker breaks ice. Since the icebreaking process is so complex, the solution of a mathematical model does not appear to be feasible. As an alternative, it is suggested that physical models be used to design icebreakers. The appropriate scaling laws for physical models are developed and their practical limitation discussed.

Description / Table of Contents: A laboratory experimental study was conducted on a scale model of an annular flow ice-water heat sink to be used to store the waste heat produced in a hardened defense installation operating in an isolated mode. The study ex­amined: 1) scaling relationships for predicting the performance of prototype units using data from scale models, 2) the accuracy of a computer prediction technique developed during an earlier study, 3) the heat transfer phenom­enon at the ice-water interface, and 4) some practical aspects related to the operation of a prototype installation. The scaling relationships and the computer program were found to be sufficiently accurate for use in developing a proto­type sink design. During operation the scale model sink provided an almost constant low temperature source of coolant water for approximately one-half its useful life and thereafter behaved like an ordinary stored water reservoir type heat sink. No significant operational problems were discovered.

Description / Table of Contents: This report summarizes the advances in understanding of the Arctic which have come about since the inception of the ARPA Arctic Surface Effect Vehicle Program in 1970, primarily as the result of CRREL’s participation. Major efforts to increase knowledge of sea ice, terrestrial, and coastal topographic features are described. Special empha­sis is placed upon the quantitative understanding of pressure ridging. Other areas of major interest are atmospheric characteristics and ecological effects. A list of publications generated is included.

Description / Table of Contents: The repair and maintenance costs of low slope roofs are high and their life expectancy is less than desired. The increasing use of insulation is accompanied by a greater incidence of problems. The experience in cold regions amplifies these experiences. Protected membrane roofs have the prerequisites for better performance and the experience to date is encouraging. The results of performance measurements of three roofs built by the Corps of Engineers verify that the membrane remains at nearly constant temperature, independent of the weather, and that the insulation retains its integrity despite periodic wetting. Moisture absorption is slow and appears to stabilize in time due to the self-drying nature of the roof. Heat losses are increased due to rain, and extra insulation should be added to compensate for these losses. The resistance of protected membrane roofs to fire, traffic, impact, and other adverse forces is superior. So far, the initial cost of protected membrane roofs is at a premium, primarily due to the cost of concrete pavers. The initial cost premium can be justified, however, by the reduced repair and maintenance costs as indicated to date, and by the longer life expectancy of the protected membrane. The high probability of superior performance and cost effectiveness is a compelling reason to incorporate protected membrane roofs increasingly in Government construction.

Description / Table of Contents: A world-wide review of the literature applicable to the design of harbors and channels in cold regions was conducted. Forces due to ice movement present the dominant factor in the design of marine structures in cold regions. Expressions for calculating the ice force are presented. Other factors relating to design criteria such as construction materials, structure geometry, and methods of ice suppression are discussed.

Description / Table of Contents: Large areas of grounded sea ice have been reported by early arctic explorers and more recently by the U.S. Coast Guard. The ESSA, ERTS, NOAA and DMSP satellites now provide multispectral imagery with sufficiently high resolution to allow detailed sequential observations to be made of the movement and spatial extent of arctic sea ice. This report discusses the location, formation and decay of five large (greater than 30 sq km) islands of grounded sea ice in the southern Chukchi Sea as observed for an extended period of time using satellite imagery. Measurements of the bathymetry around one grounded sea ice feature are presented along with observations made and photos taken from the ice surface. The potential use of these sea ice islands as research stations is also discussed.

Description / Table of Contents: At the height of warm weather in Alaska in 1975, temperature measurements were made to determine the extent of the thermal impact on French Creek due to a condenser cooling water impact from the Eielson AFB Power plant. Water temperature measurements during a two-day period failed to show any significant thermal impact on the water in French Creek. It was concluded that no thermal pollution exists due to this warm water input at the volumes and conditions that presently exist.

Description / Table of Contents: The thermal structure and ice conditions of Lake Champlain, a mid-latitude large lake, near Shelburne Point, Vermont, were studied during the winter of 1974-75. The lake was instrumented to a depth of 8.5 m with a string of highly calibrated thermistors, connected to a data logger on shore which recorded water temperatures every four hours. An ice mooring system was developed to anchor the thermistor string so that ice and water temperatures could be obtained at known levels. This temperature recording system measured vertical and horizontal variations in ice and water temperature regimes during ice formation, growth and decay. Meteorological data were measured during the winter period November 1974 through March 1975 at the site. Ice stratigraphy was determined for the ice at the site at its maximum seasonal growth for comparison with ice from St. Albans Bay (at the northern end of Lake Champlain) which had formed earlier. Correlations were determined between ice growth and accumulated degree days of freezing. The operation of a bubbler system installed near the measurement site around a service dock was observed.

Description / Table of Contents: This report, which is one of a series on the mechanics of cutting and boring in rock, deals with the kinematics of machines such as rotary drills, augers, tunnel boring machines, corers, and raise borers, in which the rotary cutting unit revolves about an axis that is parallel to the machine's direction of advance. The discussion and analysis cover the geometry and motion of various components of the cutting systems, including such topics as tool trajectories, tool speeds, motions of the more complicated mechanisms, chipping depth, penetration rates, production and clearance of cuttings, tool angles, and spatial distribution of cutters. Worked examples are given to illustrate the application of various equations to practical problems.

Description / Table of Contents: This report, which is one of a series on the mechanics of cutting and boring in rock, deals with the kinematics of machines which utilize a continuous belt as the cutting unit (e.g. coal saws, shale saws, digger-chain trenchers). The discussion and analysis cover the geometry and motion of various components of the cutting system, including such topics as chipping depth, production and conveyance of cuttings, tool trajectories, tool speeds, tool angles, and arrangement of cutting tools on the belt. Worked examples are included to illustrate the application of various equations to practical problems

Description / Table of Contents: Nondestructive repetitive plate bearing (RPB) tests were conducted on various test sections in state highways in Maine during 13-15 April 1976. The RPB test consists of making resilient surface deflection measurements during repetitive loadings at various radii from the load plate. The pavement system stiffness was calculated and the resilient modulus values for the various pavement layers were determined with the Chevron computer program for a layered elastic system. A thawed analysis using nondimensional deflection curves for the various sections provided a guide to the susceptibility of the pavement systems to surface failure and pothole development. Some comparisons between stabilized and nonstabilized aggregate and soil were made with calculated stiffness values. The moduli of the various materials were also compared. The residual surface deflections during testing for several pavement systems indicated a linear logarithmic relationship with number of load applications. A relationship between the modulus of the asphalt cement concrete pavement and pavement temperature was developed for the limited temperature range during the testing.

Description / Table of Contents: Sediments beneath the Beaufort Sea near Prudhoe Bay, Alaska, were probed at 27 sites using a static cone penetrometer to determine engineering properties and distribution of material types, including ice-bonded sediments. The probe provided both point and casing resistance data and thermal profiles. At five sites these data were correlated with information from adjacent drilled and sampled holes. These control data and the quality of the probe information permitted profiles of sediment type and occurrence of ice-bonded material to be developed along three lines that included various geological features and depositional environments. Material properties were quite variable in the upper 14 m of sediments probed. In general, softer, finer-grained sediments occurred in the upper layers, while penetration refusal was met in stiff gravels to 10 to 12 m below the seabed. Seabed temperatures during the study were all below 0 C. However, because of uncertainties in freezing point values caused by brines, evaluation of the penetration resistance data was required to identify the occurrence of ice-bonded sediments. The coupling of thermal and penetration resistance data revealed that seasonally ice-bonded sediments occurred where the sea ice froze back to or near the seabed. Deeper, perennially frozen sediments also appeared to be present at several probe sites. The penetration data obtained can be used to aid in the design of shallow and deep foundations in both ice-bonded and unfrozen subsea sediments.

Description / Table of Contents: The stress-density relaionships of snow-water mixtures were investigated and are shown as functions of water content, initial snow density, initial snow-water mixture density and rate of deformation. An increase in water content in snow at a particular density or a decrease in the rate of deformation (or strain rate) decreases the stress, but apparently not the specific energy required to reach a specific mixture density.

Description / Table of Contents: Uniaxial compression and tension tests were conducted on polycrystalline snow-ice to determine the effect of temperature on its strength. Test temperatures ranged from -O.1C to -54C. Two machine speeds, 0.847 mm/s and84.7 mm/s were used for the constant displacement rate tests. The compressive strength at -54C was about oneorder of magnitude higher than at -0.1C. The tensile strength at -18C was about 20% higher than at 0.1C. The initial tangent and 50% strength moduli are given for the compression tests, while the secant modulus to failure is given for the tension tests.The mode of fracture is discussed and the test results are compared with data from other investigations.

Description / Table of Contents: Ice fog suppression experiments on the Fort Wainwright Power Plant cooling pond were conducted during the winters of 1974-76. Baseline information studies occupied a sizable portion of the available ice fog weather in 1974-75. Then hexadecanol was added to the pond and dramatically improved visibility by reducing fog generated from water vapor released by the pond at -14 C. Although this temperature was not low enough to create ice fog, the cold vapor fog created was equally as devastating to visibility in the vicinity of the pond. During the winter of 1975-76, suppression tests were continued using films of hexadecanol, mixes of hexadecanol and octadecanol, and ethylene glycol monobutyl ether (EGME). Suppression effectiveness at colder temperatures was stuided and limits to the techniques were probed. A reinforcing grid was constructed that prevented breakup of the film by wind and water currents. Lifetime tests indicated that EGME degrades much more slowly than either hexadecanol or the hexadecanol-octadecanol mix. The films were found to be very effective fog reducers at warmer temperatures but still allowed 20% to 40% of normal evaporation to occur. The vapor thus produced was sufficient to create some ice fog at lower temperatures, but this ice fog occurred less frequently and was more quickly dispersed than the thick fog that was present before application of the films.

Description / Table of Contents: Special environmental factors that influence the design, laying and maintenance of undersea pipelines and cables in polar waters are described. Various approaches to the protection of submarine pipes and cables are considered, and prime emphasis is given to burial techniques for shallow water. A wide range of methods for trenching and burying are discussed, and technical data are given.

Description / Table of Contents: Abstract: Measurements of the concentrations of Aitken nuclei in maritime air were made near Barrow, Alaska, in June 1975 with a modified Nolan-Pollack small-particle detector. The concentrations varied from 50 to 300 particles cm^-3 depending upon meteorological conditions. The mean Aitken nuclei count was 100 particles cm^-3 for diameters greater than 2 x 10^-3 μm. Transmission electron micrographs of aerosols in maritime air near Barrow were taken. The size range was measured to be 0.01 to 2.5 μm in diameter with the most frequently observed diameter being 0.04 μm. The volume of the maritime air and the collection efficiency of aerosol particles on filmed grids for electron microscopy were measured. The aerosol concentrations were found to be 76 to 101 particles cm^-3 ; the mean concentration was calculated to be 87 particles cm^-3. The aerosol particles in the maritime air were identified by electron microscopy and selected area electron diffraction analysis. About 20% of the aerosol particles were identified, and 80% of the particles were too small for electron diffraction analysis. Sea salt particles constituted 2% of the total, and clay minerals 3%; these particles were considered to be of natural origin. Solid combustion by-products such as coagulated carbon particles and fly ash particles constituted 16%. Despite the comparative remoteness of the sampling site, the measurements indicate that many anthropogenic aerosols were found using an electron microscope.

Description / Table of Contents: The theory of non-coaxial in-plane plastic deformation of soils that obey the Coulomb yield criterion is presented. The constitutive equations are derived by use of the geometry of the Mohr circle and the theory of characteristic lines. It is found that, for solving a boundary value problem, the non-coaxial angle must be given such values that enable us to accommodate the presupposed type of flow in the given domain satisfying the given boundary conditions. The non-coaxial angle is contained in the constitutive equations as a parameter. Therefore, the plastic material obeying the Coulomb yield criterion is a singular material whose constitutive equations are not constant with material but are variable with flow conditions.

Description / Table of Contents: Tests were conducted to assess the extent of surface degradation resulting from the application of non-chloride deicing chemicals on three types of airfield pavements. The chemicals tested were proprietary mixtures of urea, formamide, and ethylene glycol; sodium chloride, distilled water, and dry specimens were used as controls and for comparison. Pavements included new and old specimens of open-graded asphaltic concrete and old specimens of dense-graded asphaltic concrete. Portland cement concrete specimens used were new and old, with and without air-entrainment. New and old tar rubber concrete specimens were also tested. Samples were subjected to up to 60 freeze-thaw cycles with deicing chemicals flooding their upper surface. Each specimen was rated on a scale of 0-5 after every five freeze-thaw cycles. All PCC specimens showed some surface degradation, whereas the dense- and open-graded asphaltic concretes were largely unaffected.

Description / Table of Contents: Abstract: The amount of force that an ice sheet can apply to a vertical pile was tested by lowering a hydraulic ram device into a hole cut in an existing ice sheet. The device had a large base and shoved a relatively narrow vertical pile in a horizontal direction. Test variables were: pile widths - 1.5 in. to 36.7 in.; pile shapes - flat, round, 45 ° and 90° wedges; ice thickness - 2.6 in. to 8.8 in.; and ram speed - 0.07 in./sec to 18.75 in./sec; but not all shapes and sizes were tested at all speeds. Air temperature was 20 ° F (-6.7 ° C). Forces and displacements were measured electronically. The findings are presented as a table of test results and as bar graphs of the resultant ice pressures versus the pile width-to-ice-thickness ratio, pile width and shape combination and pile velocity. The types of failures in the ice sheet were classified as crushing, splitting, buckling, bending, and creeping. The ice sheet generally withstood a high initial load followed by several lower peak load levels. The maximum ice pressure measured was 610 psi for a 12.6-in.-diam round pile in 8.4-in.-thick ice.

Description / Table of Contents: Two performance indicators, effectiveness and thermal efficiency, are defined and used to evaluate the year-round performance of three protected membrane roofs in Alaska and New Hampshire. Effectiveness is a measure of the deviations of ceiling temperatures from a yearly average, with large diviations indicating erratic performance in the roofing-insulation system and small departures indicating a thermally stable system. Thermal efficiency, the ratio of calculated heat loss to measured heat loss, is affected by climatic conditions such as rain, snow, solar radiation and wind. Thermal efficiency values of 100% or greater are possible since the calculated heat loss is based only on the inside and outside air temperature differences and the thermal properties of the roof components. Results of the year-round evaluation indicate that the three protected membrane roofs generally have high values of both effectiveness and thermal efficiency.

Description / Table of Contents: This report presents experimental results on the conditions of initiation of an ice jam by a simple surface obstruction, on the equilibrium thickness of an ice jam formed by accumulation and submergence of ice floes, and on the compression strength of floating, fragmented ice cover. In the study on ice jam initiation, it was found that the minimum concentration of floes in the opening of the obstruction at which a jam occurs is nearly independent of the ratio of width of constricted passage to channel width, and is proportional to a negative power of the ratio of floe length to width of constricted passage. From energy analysis of floe submergence, a relationship relating the thickness of a jam formed by accumulation and submergence of floes to the approach flow characteristics was derived and found to fit satisfactorily the experimental data. In experiments on compression strength of floating, fragmented ice cover it was found that the compressive strength is inversely proportional to compression velocity and independent of cover length.

Description / Table of Contents: The report deals with the cutting of rock and similar materials by parallel motion tools. It examines cutting forces and energy requirements, taking into consideration tool geometry, wear, operating conditions, and material properties. After an introductory discussion of terminology, some general principles are outlined, and relevant theoretical ideas on metal cutting and rock cutting are reviewed. The next section, which is the heart of the report, reviews experimental data on the magnitudes and directions of cutting forces. There is a graphical compilation of data, including some from obscure or unpublished sources. The variables covered include chipping depth, rake angle, relief angle, side rake, base angle, tool width, tool compliance, tool speed, tool wear, tool interactions, and material properties. The second major part of the report treats the energetics of cutting. It begins with a short discussion of relevant principles, and continues with a compilation and review of experimental data, covering the same independent variables as the force section. The report ends with a concise summary of general behavior for parallel motion tools.

Description / Table of Contents: Access to study areas may be an important factor in long-term field-oriented research, particularly in-regions without well-developed road and communications systems. In a wildland hydrometeorology research project in subarctic Alaska, access to and within a 40-square-mile research watershed has been developed both in accordance with a general plan prepared at project inception and in response to developing research requirements. Foot trails, trails for 'off-road' low-ground-pressure tracked vehicles, helicopter transport, long-term data recorders, and radio telemetry of data have all been incorporated in an access and communications system. Cost estimates indicate that incorporation of gravel roads into the system would be economically advantageous, given adequate funding for initial road construction.

Description / Table of Contents: A commercial deep-freeze unit was modified to serve as a laboratory for growing single crystals, cutting specimens of a given orientation, testing these specimens in compressive creep, and studying thin-sections of the results on a universal stage. A method of growing single crystals of adequate size was developed by adapting the Bridgman method. Fortyone creep tests were made at temperatures ranging from -1° to -18°C. These gave an unexpected form of creep-curve in which the rate of strain continuously increases with time. The mechanism of deformation is dominantly basal translation—consistent with earlier work. The dependence on temperature and stress is expressed empirically.

Description / Table of Contents: Work carried out at the SIPRE Test Site, Site 2, on the Greenland Ice Cap,during the summer 1954, included: (1) Excavation of trenches, a circular tunnel and a deep pit; (2) Instrumentation of excavations for pressure and deformation measurements; (3) Tests on the properties of snow from the deep pit; (4) Construction of a snow house as an experimental structure and to provide a heated shelter for an observer stationed at the site for the winter. Observations and measurements over a period of five years are expected to provide sufficient information for the establishment of satisfactory design criteria for all kinds of surface and subsurface military installations on high polar ice caps.

Description / Table of Contents: Water flow through the vein structure of temperate ice is described as Darbian flow in which the pressure gradient is determined from vein size and overburden pressure. A solution method for the resulting equation is given and two special cases are considered. For steady flow the equilibrium vein size is a function of depth and, by neglecting the effects of diffusion, it is shown that flow perturbations introduced at the surface propagate downward at a constant speed.These perturbations propagate so slowly that even annual surface fluctuations of flow may be eliminated by diffusion before reaching the bottom of the glacie

Description / Table of Contents: The heat transfer processes associated with melting and refreezing a drill hole 500 m in depth and 0.150 m in initial radius through an ice shelf were approximately analyzed. The results were expressed in graphical form showing the time available for experimentation under the hole as a function of heating duration and heating strength. It was found that the refreezing of the drill hole had a much slower rate than the melting of the hole.

Description / Table of Contents: Under ordinary conditions the freezing of water begins with supercooling and ice nucleation, and proceeds at 0°C at the ice/water interface until ice formation stops. The presence of solutes, high pressure, or dispersal in fine pores causes the water to freeze at temperatures below 0°C (the so-called freezing point depression). Whenever freezing begins, it pro­ceeds at a constant temperature, or at a temperature which becomes progressively lower. A temperature rise during ice formation is considered here to be an anomaly. Under all equal circumstances, the conditions under which an anomal­ous freezing temperature is observable appear to be very special. This report describes two different experiments dis­playing the anomalous rise of temperature after nucleation and during ice formation. In one case the water was dispersed in the fine pores of fine powders; in the other case pure water was frozen in a transparent insulated cell. Photographic observations were made; relations of ice surface to water volume were measured.

Description / Table of Contents: Three surface elevation and ice thickness profiles obtained during the 1972 Arctic Ice Dynamics Joint Experiment on a multiyear ice floe were analyzed to obtain relationships between surface elevation, thickness and physical properties of the ice. It was found that for ice freeboards from 0.10 m to 1.05 m above sea level a linear relationship between ice density and freeboard could be postulated. The equation for the regression line is: Ice density = -194f' + 974 kg/cu m where f' is the ice freeboard plus snow depth in ice equivalent at the point in question. This statistical relationship is consistent with observed physical properties, which indicate that as the ice freeboard increases, ice salinity decreases and the higher freeboard or thicker ice therefore decreases in density. Using this variable density with freeboard relationship, a model was constructed to predict ice thickness, given ice freeboard and snow depth alone. This prediction is desirable, since snow depth and freeboard are relatively easy to obtain, whereas ice thickness can usually be obtained only by drilling through the ice. The model was compared with two other models. It was found that the variable density prediction model gave the best approximation to observed ice thickness, with a standard error between the measured and predicted value of about 0.4 m, compared with errors from 50 to 100% higher for the other two models.

Description / Table of Contents: The effects of snow temperature and initial density on the stress vs density and stress vs deformation relationships were investigated for shallow compacted snow in the density range of 0.28 to 0.76 g/cu m, for stress range of 0.5 to 72 bars and a temperature range of -1 to -34 C at a deformation rate of 40 cm/s. A decrease in temperature increases the resistance to stress, the effect increasing with applied stress. For any stress, an increase in the initial density results in an increase in the resulting density, the effect decreasing with an increase in stress. The approximate yield envelopes, which define the stress required to initiate any deformation of snow of a particular density and temperature, were determined. Rapid compaction of snow results in extensive recrystallization, significantly different from that of naturally compacted snow. At a stress of 72 bars, transformation to ice occurs only at temperature above -10C.

Description / Table of Contents: Sea ice ridging statistics obtained from a series of laser surface roughnessprofiles are examined. Each set of profiles consists of six 200-km-long flight tracks oriented approximately perpendicular to the coastline of the Chukchi and Beaufort Seas. The landward ends of the profiles were located at Point Lay, Wainwright, Barrow, Lonely, Cross Island and Barter Island. The flights were made in February, April, August, and December 1976, and one additional profile was obtained north of Cross Island during March 1978. It was found that although there is a systematic variation in mean ridge height (h) with season (with the highest values occurring in late winter), there is no systematic spatial variation in h at a given time. The number of ridges/km (micron) is also high during the late winter, with the highest values occurring in the Barter and Cross Island profiles . In most profiles, the ice 20 to 60 km from the coast is more highly deformed (higher micron values) than the ice either nearer the coast or farther seaward. The Wadhams model for the distribution of ridge heights gives better agreement with observed values in the higher ridge categories than does the Hibler model. Estimates of the spatial recurrence frequency of large pressure ridges are made by using the Wadhams model and also by using an extreme value approach. In the latter, the distribution of the lagest ridges per 20 km of laser track was found to be essentially normal

Description / Table of Contents: Abstract: This investigation utilized historical and recent aerial photographs and satellite imagery in 1) estimating changes in positions of the high-water line and sea cliff break and base, in rates of accretion and/or erosion, and in volumes of transported sediment, and 2) providing a preliminary evaluation of the direction of littoral transport along the outer Cape Cod coast. Using aerial photographs acquired in 1938, 1952, 1971 and 1974 with manual photointerpretation techniques, changes in the distances from selected reference points to the cliff break, cliff base and the high-water line were measured. LANDSAT-1 and -2 imagery acquired from 1 September 1972 to 28 May 1975 was evaluated for use in determining the directions of littoral transport that are active the predominant amount of time. Although the imagery has been very useful for this purpose at other locations, it proved to be useless along the outer shore of Cape Cod. Largest net migrations of the high water line from 1938 to 1974 occurred in the northern and southern portions of this coast. The northern maximum high water line was 321.4 ft, the southern was 1794.6 ft. The central portion of the coast was generally more stable with changes varying from 6.8 to 157.6 ft. Cliff-base recession rates varied from 0.4 to 7.3 ft/yr. Maximum estimated net volume of sediment deposited per linear foot of beach from 1938 to 1974 was 334 yd^3 (based on 2 yd^3/ft of recession or accretion); maximum eroded was 914 yd^3. Changes in the configuration of spits were used to evaluate directions of littoral transport since suspended sediment concentrations were generally not sufficient to act as natural tracers of surface currents. Based on the literature and a determination of the portion of the coast perpendicular to the direction of dominant wave approach, the location of the nodal zone for predominant littoral directions of drift probably shifts between the area near Spectacle Pond and North Truro Air Force Station. This investigation has illustrated a photo interpretation technique that is useful in performing a reconnaissance of coastal change. The data obtained from this method can be used to supplement those acquired by ground surveys and are valid as first approximations for planning subsequent, more detailed surveys.

Description / Table of Contents: Experiments were conducted to study the flow of water through columns of homogeneous, repacked snow. The gravity flow theory of water flow through snow was verified, although possibly there is some dependence of the relative permeability on the state of metamorphism of the snow. Also, at very large values of saturation there may be some additional flow in saturated channels.

Description / Table of Contents: The interaction of a 5.1-GHz transverse electric surface wave with a dielectric slab is experimentally investigated. The wave is initially supported by a dielectric substrate resting upon a metallic ground-plane. A slab, made of the same dielectric material as the substrate and variable in height, is then placed upon the waveguide. The results for a small slab sitting on the substrate showed that the discontinuity was a very inefficient launcher of reflected surface waves. Investigations of these reflections with a trough waveguide showed that, for values of slab height comparable to the exponential decay height of the surface wave, the reflections remain very small. However, as the slab height is increased beyond the decay height, the reflected amplitude approaches the theoretical value for a plane wave reflected from the interface between air and the same dielectric. The results are applicable to surface wave methods of microwave deicing of wings and helicopter rotors.

Description / Table of Contents: A theory for ice forces acting on inclined wedges has been developed, thus making it possible to predict the magnitude of the intermittent ice forces from knowledge of the physical parameters of the system. The theory has been verified by model tests with artificial and natural ice.

Description / Table of Contents: A broadbanded impulse radar system was used for aerial detection of accumulated frazil and brash ice in a 9.5-km reach of the St. Lawrence River near Ogden Island. The remote sensing and data reduction system developed for the project provided data sufficient for production of a contour map having 1-ft intervals. With this contour map, the accumulation pattern of frazil and brash ice could be analyzed. Recommendations are given for improving the performance of the aerial profiling system.

Description / Table of Contents: A computer program to calculate the increased live load on a snow-covered roof due to rain-on-snow is given. For the 25-year rainstorm falling on a heavy snow load on a flat roof in Hanover, New Hamsphire, and additional 98 kg/m2 (20 lb/ft2) of liquid water is added to the live load. The additional load due to rain-on-snow is very sensitive to the snow properties and characteristics of the roof. A wide range of live loads is possible, depending on the particular circumstances.

Description / Table of Contents: The breakup of the Chena River was observed and documented during the spring of 1975 and 1976. This study attempted to determine the potential for damage to the proposed Chena River flood control dam from ice and debris during breakup. Results of this study were compared to those of a 1974 companion study. In 1975, ice thickness were determined to be 15% thinner than in 1974 and ice volume was 33% smaller. No major ice floes were observed in 1975 and no significant flooding occurred, although the approaches to a bridge at the damsite were eroded by debris and high water immediately after breakup. The 1976 breakup was milder than that of 1975. Minor flooding in the lower river was caused by jamming of a few large ice pieces, but no property damage resulted.

Description / Table of Contents: The mathematical theory for the bearing capacity of river ice for vehicles is presented. The floating ice sheet is assumed to have simple supports at the shore line. Solutions are presented for loads uniformly distributed over circular and rectangular areas. Numerical evaluations are made for a number of vehicles and the results presented in graphical form

Description / Table of Contents: The use of radio-echo sounding records to indicate the presence of internal layers within large ice sheets is of interest to glaciologists because it offers a means of tracking the internal properties of the ice sheets over large distances. The interpretation of the reflections obtained in this manner is more valuable, however, if a physical property change relating to the glaciological regime can be related to the dielectric property change producing the radio-echo reflections. In this report, we use the measured physical properties of core to bedrock taken at Cape Folger, East Antarctica (66 deg 22 min s, 111 deg (E), 324-m depth), to compute a profile of dielectric properties and from this, a depth-reflection coefficient profile for comparison with observed radio-echo reflections. The measurements available on physical properties are: density variations, bubble size and shape changes, and crystal fabric variations. The depths of the strong reflections shown on the available radio-echo records are in reasonable agreement with the depths corresponding to the highest reflection coefficients computed from the combined physical property measurements. In calculations to differentiate the separate effects of different physical properties, it appears that density variations account for the primary contributions to the calculated dielectric property changes corresponding to the highest reflection coefficients. However, bubble changes alone can also account for reasonable, though lower, reflection coefficients at the appropriate depths. Crystal fabric variations correspond poorly with the reflection locations. Density variations are normally associated with depositional events in the history of the ice sheet.

Description / Table of Contents: Ten roofs in Concord, New Hampshire, were surveyed for wet insulation using a hand-held infrared camera. Suspected wet areas were marked on the roof with spray paint and roof samples were obtained to verify wet and dry conditions. Recommendations for maintenance and repair were made based on infrared findings, water contents, and visual examinations. An incremental economic study is presented to serve as a guide in determining the most cost-effective approach.

Description / Table of Contents: A literature search was made for information on the accretion of ice on ocean structures and on methods for control. The bulk of the reports were in Russian, with some additional Japanese, British, American, Canadian, and Icelandic sources. Analysis of icing reports indicated that sea spray is the most important cause of ship icing, with lesser amounts due to freezing rain, snow, and fog. Icing is a potential danger whenever air temperatures are below the freezing point of water and the sea temperature is 6 C or lower. Theoretical work on the ice accretion process is discussed, and a method is suggested, based on Russian experiments, for calculating the sea spray accumulation rate for cylindrical and flat surfaces as a function of water source temperature, air temperature, and wind speed. Other factors that influence icing severity are ship size and configuration, angle between ship course and water heading, and ship speed. Icing in the north temperate latitudes generally occurs in the rear of barometric depressions. Maps showing limits of various degrees of icing severity are included. Atmospheric icing measurements on tall land-based structures are presented, and potential maximum accumulations estimated. Control measures are discussed, though no completely effective method is available. Mechanical (impaction) methods are the most common, but experiments have been conducted on heated, icephobic, and deformable surfaces, and with freezing point depressants. No device for the unequivocal measurement of ice accumulation is available, though some experimental methods are suitable for controlled testing; it is recommended that a device be developed.

Description / Table of Contents: Griffith, and later Babel, have previously developed a tensile fracture criterion for a two-dimensional state of stress. This theory is extended to the compression-compression region. From this theory the angle of fracture is developed. The theory is extended conceptually to three dimensions. Triaxial test data by Haynes for snow-ice are shown in this three-dimensional fracture theory. The test data are slightly less than those predicted when the void in the snow-ice is spherical.

Description / Table of Contents: During the past decade a number of methods for measuring the amount of unfrozen water in partially frozen ground have emerged. Means of quickly and simply predicting unfrozen water contents in clay have become increasingly important with the growth of interest in encapsulating clay soils compacted at low water contents to serve as base courses for roads. Unfortunately the measurements require sophisticated equipment and, in most instances, specially trained operators. In an effort to simplify the task of obtaining water-ice phase composition data, methods of calculating phase composition curves from other, simpler measurements on soils have been sought. The paper presents a method of deriving the measurement of unfrozen water contents at various temperatures from liquid limit determinations.

Description / Table of Contents: This report covers a series of cantilever beam tests designed to determined the efficacy of adding reinforcement to an ice cover. Tests were run using 1-in.-diam tree branches, 3/16-in.-diam wire rope and 9/16-in. half-round wood dowels as reinforcement for both seawater and freshwater ice. The results show a definite advantage derived from using reinforcement, even when poorly placed. The results also show that reinforced ice carries a load even after it cracks. Thus, after the initial cracks there is time to remove people and equipment before final breakthrough. One must bear in mind, however, that reinforcement has disadvantages. The darker reinforcement absorbs solar radiation and thereby causes earlier weakening of the ice cover. Also, in many cases the time and effort required to place reinforcement may exceed those required to achieve equal strength by additional thickening of the ice sheet. This study has shown that understanding of the failure mechanism of ice under repetitive loading is poor and that future studies should be performed on this problem. Also, this study covered only cantilever beams. The actual field problem is strengthening a three-dimensional sheet. Hence, distribution and orientation of the reinforcement should be addressed in future studies.

Description / Table of Contents: Several membrane materials used or considered for MESL (membrane-enveloped soil layer) utilization of poor soils in road construction have been tested for cold effect on puncture and stiffness. PE (polyethylene) film was also tested for solvent soak effects. A simple blunt needle apparatus was devised for puncture testing. For plastic films (mainly PE), both puncture resistance and stiffness increase at low temperature (0 F, -18 C). For non-woven, spunbonded fabrics these properties are little affected by cold. For both non-wovens and PE film, puncture and bending strengths increase linearly with weight or thickness. The slope is steeper for the non-wovens, which generally are stronger on a per unit weight basis. PE film soaked in a hydrocarbon solvent swelled approximately 17% and lost about 30-40% its puncture strength. These effects are apparently reversible upon drying. Consideration has been given to sealing and patching requirements and to the drying of sealant liquids when adhering film to film. Also considered have been pos­sible slippage related to the reported low angle of friction of plastic films in soil and the possibility of lamination for improved membrane properties.

Description / Table of Contents: CONTENTS: Abstract. - Preface. - Introduction. - Experimental. - Results and discussion. - Applications. - Literature cited.

Description / Table of Contents: Chemical analysis of century-old ice from continuous 5 to 7 year intervals of three ice cores from south and central Greenland (Dye 3, Milcent and Crete) show maximum concentrations of Na, Mg,Ca, K, and Al during early spring and minimum concentrations during late summer and early fall. Peak spring values are as much as 10 times greater than fall values. Because of the large seasonal chemical variations, samples used for depth-age or annual deposition rate studies must represent accumulation from exactly one year or whole multiples of a year. The seasonal chemical variations seem promising as a new method of defining annual layers and thus dating old ice cores.

Description / Table of Contents: CONTENTS: Abstract. - Preface. - USA CRREL project and personnel involvement. - Part I. Introduction. - Background. - Literature review. - Part II. CRREL investigations from 1970 - 1974. - Initial literature survey (1970). - Oil detection kit development. - Survey of Cape Simpson, Alaska, natural crude oil seepages (1970). - Haines-Fairbanks military pipeline investigations (1971-1973). - Barrow investigations (1970-1974). - Fairbanks and Fox investigations. - Germination studies. - Physiological studies. - Dispersant studies. - Microbiological investigations. - Field investigations of accidental petroleum losses. - Part III. Recent related literature. - Part IV. Conclusions and recommendations. - USA CRREL reports, publications and presentations on Alaska oil spill research. - Literature cited.

Description / Table of Contents: Knowledge concerning the biological effects of oil pollution on arctic and subarctic terrestrial ecosystems is limited. USA CRREL research personnel conducted investigations from 1970 through 1974 to expand information in this field. Objectives were to: 1) define the ecosystems most sensitive to the presence of crude oil or its refined products, 2) quantify and understand the injury response, and 3) establish time frames for manifestation of damage and natural restorative processes in arctic and subarctic regions. This was accomplished through: 1) surveys of natural oil seepages and past accidential spills in the Arctic and Subarctic, 2) initiation of controlled oil spills and 3) detailed laboratory investigations. Results demonstrated that terrestrial oil spills will to some degree be detrimental to both arctic and subarctic plant communities. Degree and longevity of damage will be influenced primarily by the magnitude of the spill, season of occurrence and existing soil moisture content. Rapid recovery of plant communities subjected to spills will occur only if root systems remain relatively unaffected. Damage will be more extensive and long-term when root systems are saturated with oil. Effects of damage will be manifested gradually over several seasons being influenced by winter stresses. Variation does exist in plant species susceptibility. Carex aquatilis, a predominant sedge of the arctic, is markedly resistant to crude oil damage. In the taiga Picea mariana is very susceptible. Plant recovery can be enhanced through the application of fertilizer. Fertilization, in addition to its direct effect on plant nutrition, will stimulate microbial decomposition of crude oil.

Description / Table of Contents: CONTENTS: Abstract. - Preface. - Introduction. - Discussion of heat loss survey of six housing units. - Survey of base facilities. - Conclusions. - Literature cited.

Description / Table of Contents: During the winter of 1973-74 a mobile infrared thermography system was used to survey housing units and base facilities at Pease Air Force Base, Portsmouth, New Hampshire. This report provides both qualitative and quantitative evidence regarding heat flow out of the eave vents of these housing units. Calculations indicate that a significant amount of heat is being lost in this manner due to inadequate attic (cap) insulation. Possible evidence of incomplete ventilation could explain the presence of condensation in the housing units. Analyses of thermograms are presented to show the possible existence of low and high pressure areas around a structure and how they relate to heat loss.

Description / Table of Contents: The internal friction of single-crystal ice has been attributed to reorientation of the water molecule under periodic stress. However, the theory for damped dislocations, which offers another mechanism for the internal friction of ice, has not been investigated. The effects of scratching the surface of 41 ice samples and X-irradiating and plastically deforming them were evaluated. The effects observed on the internal friction of pure, single-crystal ice, in the flexure mode of oscillation between 400 and 1400 Hz, supported the existence of a dislocation-controlled mechanism, with the drag produced by the interaction of the dislocation with the protons in the crystal. In addition, analysis of the detailed shape of the data curve showed two peaks of tan delta as a function of temperature. The second peak, which had not been previously reported, had an activation energy of 0.16 eV and a relaxation time of 1.7 x 10^8 sec at infinite temperature. These experiments indicated that both peaks vrere controlled by the dislocation mechanism described above.

Description / Table of Contents: Table des Matières: Aurores boréales observées a Godthaab (1882-83) / Adam Paulsen. - Observations magnétiques faites a Godthaab (1882-83) / Adam Paulsen. - Les températures moyennes de l'eau de mer a la surface, pour les mois d'avril a septembre, sur les routes de la cote nord de l'Écosse a l'ile d'Islande et au Groenland / Adam Paulsen. - Observations météorologiques de Godthaab (1er Aout 1882 - 31 Aout 1883) comparées avec celles qui ont été faites pendant une série d'années sur la cote occidentale du Groenland / Adam F. W. Paulsen. - Flux et reflux de la mer a Godthaab calculés d'après une série d'observations horaires (16 Juillet - 31 Aout 1883) / C. Crone. - La longitude de Godthaab déterminée d'après les observations de MM. Falbe, Bluhme et Ryder / V. Hjort. - Observations de Godthaab / Adam F. W. Paulsen. - Observations météorologiques de Godthaab (1er Aout 1882 - 31 Aout 1883) et de la cote ouest du Groenland / Adam F. W. Paulsen. - Observations météorologiques faites pendant la dérive de la Dijmphna dans la Mer de Kara (1882-1883) / A. P. Hovgaard. - Observations météorologiques et nautiques faites a Nennortalik et a Angmagsalik par les membres de l'expédition de M. Le Capitaine G. Holm pour explorer la cote est du Groenland.

Description / Table of Contents: Contents: Report of the commanding officer. - Appendices. - 1. War Department order assigning Lieutenant Greely to command. - 2. War Department order organizing the expedition. - 3. Instructions from the Signal Office regarding the expedition. - 4. List of commissary subsistence stores, with remarks thereon. - 5. Records left at and taken from Southeast Cary Island, August, 1881. - 6. Lieutenant Kislingbury's report of trip to Life Boat Cove. - 7. Records taken from and left at Washington Irving Island, August, 1881. - 8. Records obtained at Discovery Harbor, August 1, 1881. - 9. Lieutenant Lockwood's report on Water-course Bay, August, 1881. - 10. Lieutenant Kislingsbury's request to be relieved, with Lieutenant Greely's indorsement. - 11. Orders No. 5, relieving Lieutenant Kislingsbury and ordering him to report to the Chief Signal Officer. - 12. Orders No. 6 amending Orders No. 5. - 13. Lieutenant Kislingsbury's request for modification of Orders No. 6. - 14. Orders No. 8 modifying Orders No. 6. - 15. Lieutenant Lockwood's report on exploration of St. Patrick Valley. - 16. Sergeant Brainard's report establishing Depot B near Cape Beechy. - 17. Sergeant Jewell's meteorological report in connection with trip establishing Depot B. - 18. Sergeant Gardiner's report of trip to Cape Murchison. - 19. Sergeant Linn's report on moving Depot A to Cape Murchison. - 20. Orders to Dr. Pavy for overland journey to Lincoln Bay. - 21. Report of Dr. Pavy on trip to Lincoln Bay. - 22. Report of Lieutenant Lockwood on journey to the Bellows. - 23. Orders to Dr. Pavy on exploring Archer Fiord. - 24. Report of Dr. Pavy on attempted trip down Archer Fiord. - 25. Report of Lieutenant Lockwood on sledge journey to Depot B near Cape Beechy. - 27. Orders to Dr. Pavy to proceed to Cape Joseph Henry. - 28. Report of Dr. Pavy on trip towards Cape Joseph Henry. - 29. Lieutenant Lockwood's report on St. Patrick Valley. - 30. Sergeant Rice's report on camp equipage. - 31. Lieutenant Lockwood's orders to attempt crossing of Robeson Channel. - 32. Lieutenant Lockwood's report on attempted crossing of Robeson Channel. - 33. Dr. Pavy's orders for journey to Wrangel Bay. - 34. Dr. Pavy's report on journey to Wrangel Bay. - 35. Dr. Pavy's supplementary report under Appendices 27 and 33. - 36. Lieutenant Lockwood's orders for preliminary journey to Cape Beechy. - 37. Lieutenant Lockwood's report on journey ordered in Appendix No. 36. - 38. Lieutenant Lockwood's orders for journey to Thank God Harbor. - 39. Lieutenant Lockwood's report on journey ordered in Appendix No. 38. - 40. English records obtained at Thank God Rarbor. - 41. Dr. Pavy's orders to carry provisions to Greenland coast. - 42. Dr. Pavy's report on journey ordered in Appendix No. 41. - 43. Sergeant Brainard's orders to move boat to Greenland coast. - 44. Sergeant Brainard's report on trip ordered in Appendix No. 43. - 45. Sergeant Jewell's report on trip to Lincoln Bay while supporting Dr. Pavy. - 46. Dr. Pavy's orders for journey northward over Polar Ocean. - 47. Dr. Pavy's report on journey ordered in Appendix No. 46. - 48. Sergeant Rice's report on detached trip from Lincoln Bay to Fort Conger and return. - 49. Private Long's report on trip into Archer Fiord. - 50. Sergeant Israel's report on trip into the Bellews. - 51. Lieutenant Lockwood's orders lo explore north coast of Greenland. - 52. Supplementary instructions for exploration of north coast of Greenland. - 53. Lieutenant Lockwood's report on exploration of north coast of Greenland. - 54. Report of Private Biederbick's trip into Black Rock Vale. - 55. Sergeant Linn's report of trip into Black Rock Vale. - 56. Lieutenant Lockwood's report of launch trip up Archer Fiord. - 57. Lieutenant Lockwood's report of launch trip up Chandler Fiord. - 58. Dr. Pavy's orders to proceed to Carl Ritter Bay. - 59. Sergeant Elison's report of trip to Carl Ritter Bay. - 6o. Sergeant Brainard's report of trip to Carl Ritter Bay. - 61. Orders establishing day of "Thanksgiving". - 62. Dr. Pavy's Ietter of March 8, 1883. - 63. Lieutenant Greely's answer to Dr. Pavy's Ietter of March 8, 1883. - 64. Lieutenant Lockwood's orders for preliminary journey northward, 1883. - 65. Lieutenant Lockwood's report on journey ordered in Appendix No. 64. - 66. Sergeant Jewell's report to Lieutenant Lockwood relative to journey ordered in Appendix No. 64. - 67. Orders to Lieutenant Lockwood for exploration of Greenland, 1883. - 68. Sergeant Rice's orders for journey to Thank God Harbor. - 69. Dr. Pavy's orders for journey, as surgeon, to Thank God Harbor. - 70. Lieutenant Lockwood's report on trip to North Greenland. - 71. Sergeant Jewell's report on tidal and meteorological observations made on trip to North Greenland. - 72. Sergeant Rice's report on trip to Thank God Harbor. - 73. Dr. Pavy's medical report on trip to Thank God Harbor. - 74. Orders for Sergeant Jewell for tidal observations at Cape Beechey. - 75. Report of Sergeant Jewell on tidal observations at Cape Beechey. - 76. Orders for Sergeant Gardiner for tidal Observations at Cape Baird. - 77. Orders for Sergeant Israel for astronomical Observations at Cape Baird. - 78. Report of Sergeant Israel on observations ordered in Appendix No. 77. - 79. Report of Sergeant Gardiner on tidal and ice observations at Cape Baird. - 80. Report of Sergeant Jewell on paleocrystic ice. - 81. Orders to Sergeant Jewell for tidal Observations at Cape Beechey. - 82. Report of Sergeant Jewell on tidal Observations at Cape Beechey. - 83. Sergeant Brainard's report on journey to Cape Cracroft. - 84. Sergeant Gardiner's report on journey to Cape Cracroft. - 85. Lieutenant Lockwood's orders to cross Grinnell Land. - 86. Lieutenant Lockwood's report on the crossing of Grinnell Land. - 87. Orders to Dr. Pavy relative to natural history data. - 88. Orders to Dr. Pavy relative to botanical specimens. - 89. Orders to Lieutenant Lockwood to relieve Dr. Pavy as naturalist. - 90. Lieutenant Lockwood's report on natural history specimens received from Dr. Pavy. - 91. Lieutenant Lockwood's Ietter and report on natural history specimens, June 30, 1883. - 92. Sergeant Brainard's report on Lieutenant Lockwood's trip towards the United States Mountain range. - 93. Orders to Lieutenant Lockwood to receive medical stores from Dr. Pavy. - 94 Letter of Dr. Pavy asking the detail of Steward Biederbick. - 95. Reply of Lieutenant Greely to Dr. Pavy's request for detail of Steward Biederbick. - 96. Letter of Dr. Pavy's, dated July 18, 1883. - 97.Answer to Ietter referred to in Appendix No. 96. - 98. Dr. Pavy's refusal to turn over his diary. - 99. Letter transmitting charges to Dr. Pavy. - 100. Letter limiting Dr. Pavy's bounds while in arrest. - 101 Order for the abandonment of station at Fort Conger. - 102. List of subsistence stores abandoned. - 103. Medical reports. - 104. Record left at Cape Baird. - 105. Records left in abandoned boats. - 106. Records found on Brevoort Island ( deposited by Lieutenant Garlington and Private Beebe). - 107. Plan of winter quarters, Camp Clay. - 108. Sergeant Frederick's report of November journey to Cape Isabella. - 109. Lieutenant Kislingsbury's letter, February 19, 1884. - 110. Private Long's journey into Hayes Sound. - 111. Sergeant Frederick's report of journey to Baird Inlet, April, 1884. - 112. Lieutenant Kislingsbury's letter, April 22, 1884. - 113. Letter of Dr. Pavy's, April 25, 1884. - 114. Letter of Dr. Pavy, April 27, 1884. - 115. Lieutenant Greely's certificate to Dr. Pavy. - 116. - General certificate to Dr. Pavy. - 117. Letter of Lieutenant Greely on Dr. Pavy. - 118. - Oder for Private Henry's execution. - 119. Report of Private Henry's execution. - 120. Letter of Secretary of War approving Lieutenant Greely's course regarding execution of Private Henry. - 121. List of deaths. - 122. Order relative to Private Henry, dated June 5, 1884. - 123. Lieutenant Lockwood's journal from August 3, 1883. - 124. Sergeant Brainard's journal from besetment. - 125. Portion of diary of Private Roderick R. Schneider, found on bank of Mississippi River, in Missouri, and correspondence relating thereto with Mr. J. A. Ockerson. - 126. Description of drift-wood. - 127. List of photographs and description of Eskimo relics in photographic plates. - 128 List of maps and charts. - Index to Vol. 1.