Cm Of Surface Research Articles

#43 Fungal colonization by Pneumocystis is highly frequent in the human placenta at birth.

Abstract Background Pneumocystis is well-known as a pathogen of the severily immunocompromised host. However, this fungus is also, a frequent colonizer of immunocompetent hosts inducing subclinical characteristic histologic features of Th2-type lung inflammation, and is associated to asthma. The pathology that Pneumocystis induces in the lung of non-severily immunocompromised hosts warrants exploring whether it colonizes and induces pathology in other organs. Physiologically immunosupressed pregnant women display increased nasal carriage of Pneumocystis and, of interest, Pneumocystis pneumonia were reported in neonates or still-born infants before the AIDS epidemic, and Pneumocystis-DNA has recently been identified in formalin fixed fetal organs. In addition, transplacental transmission has been documented in rabbit does that have an hemo-monochorial placenta similar to humans. Moreover, fungal species are a frequent cause of chorioamnionitis and fetal death in farm cattle. Motivated by these observations, we undertook a search for Pneumocystis in the placenta of full term pregnancies in Santiago, Chile. Method 106 prospective volunteer mothers were approached during early labor at the San Jose Maternity Hospital in Santiago. After signed informed consent, the placenta of 91 full-term deliveries (37-42 weeks) was collected in a sterile bag and transported at 4°C to the research laboratory for immediate surgical removal of 0.5 cm of surface of each cotyledon at the maternal side in a laminar flow hood before sampling. The exposed cotyledons were then dissected to obtain approx 2 g (1.02-2.2 g) tissue from each cotyledon and samples from 3-4 cotyledons were pooled in two samples of approx. 7 (5.34-8.06) grams per each placenta. A 2 gram aliquot from each sample was homogeneized and DNA was extracted using QIAmp DNA extraction kit (QIAGEN) with an additional bead beating step. Pneumocystis was diagnosed by nested-PCR amplifying the mtLSUrRNA and the beta-tubulin loci of P. jirovecii. Pneumocystis was additionally examined by microscopy immunofluorescence in a subset of DNA-positive samples using immunofluorescence kit (Meridian). Results Pneumocystis jirovecii-DNA was detected by amplification of the two loci in 35 (38.5%) of 91 placentas; In 25 after analysis of the first sample tissue pool, and the other 10 after analysis of the second pooled sample. Characteristic Pneumocystis cyst forms were documented by IF microscopy in 4 P. jirovecii DNA positive samples. Conclusion Pneumocystis colonization of the placenta at full term is highly frequent and can be detected by DNA amplification and, more laboriously, by immunofluorescence microscopy. Placental colonization is focal, similar to what occurs in the lung during primary infection. Data suggests transplacental as a route of transmission of Pneumocystis in addition to the aerial route in humans. It also warrants exploring placental inflammation associated to Pneumocystis as documented in the colonized lung. Further studies are needed to determine the significance of placental colonization by Pneumocystis in the placental unit.

Habitat Use, Activity Patterns, and Survival of Louisiana Pinesnakes (Pituophis ruthveni) in West-central Louisiana

Pituophis ruthveni (Louisiana Pinesnake) is considered to be one of the rarest snake species in North America and, accordingly, was federally listed as threatened under the Endangered Species Act in 2018. Although much previous work has demonstrated the species' tight association with its primary prey, Geomys breviceps (Baird's Pocket Gopher), relatively little work has been done on habitat selection, hampering management and conservation efforts. Here we use a variety of technologies, including traditional radio-telemetry, automated radio-telemetry, and subsurface temperature loggers, to monitor Louisiana Pinesnake behavior and habitat use for one of the few remaining populations of the species. We find support for previous studies indicating that Louisiana Pinesnakes exhibit bimodal seasonal activity patterns and preferences for areas with Baird's Pocket Gophers. However, we also document extensive individual variation in behavior and habitat use with some individuals exhibiting small home ranges (8.36 ha) in relatively open habitats and others with much larger home ranges (166.83 ha) in relatively closed habitats. These results suggest that Louisiana Pinesnake habitat selection, although largely restricted to areas with pocket gophers, can be extremely variable in other habitat features. Based on subsurface temperatures, our results suggest that snakes are most often found relatively close to the surface (88% of observations within 15 cm of surface) when utilizing burrows. Although we document relatively high annual survival (56%) compared to previous studies, we also detected Ophidiomyces ophiodiicola, the fungal causative agent for snake fungal disease, in 3 of our 7 individuals included in the study, highlighting the continued threats facing the species.

Phisycal And Chemical Properties And Nutrient Content (N, P, K, Mg, B, Cu And Zn ) In Oil Palm Leaf In Various Of Age After Compacting

Planting of oil palm in peatland has been limited by soil physical, chemical properties, and hydrology, that`s way needed improvement on those matters to increase the productivity of peat and oil palm in peat soil by compacting. The purpose of this compacting is to improve the soil's physical, chemical properties, and soil moisture. A sampling of soil, water, and leaf were done in consecutive block 5,4,3,2,1,0 year after compacting and of planting done 4 years 10 months, 3 years 9 months, 2 years 9 months, 1 year 10 months, 11 months and 2 months, control used in this trial are origin condition (forest). Increasing bulk density was found at compacting block with 30 cm depth from the surface with the lower in 2 years after compacting at 0.09 g/cm3 and highest 4 years after compacting 0.4 g/cm3. In-depth of 60 cm from surface was found no increasing the bulk density 3 years after compacting 0.0 g/cm3 and the highest on 5 years after compacting 0.3 g/cm3 compared to forest. Decreasing on permeability in-depth 30 cm at 4 years after compacting 7.47 cm/jam and close to forest permeability 51.11 cm/hour is 2 years 43.6 cm/hour. As represent rise capillary consistently water content ≥ 80% achieved at depth 20 cm of surfaces on all block. Compaction doesn't regard pH, C organic, basa's saturation, capacity exchange cation. On depth 30 cm P-total lower on s without compaction at 599.6 ppm and above 871.6 ppm on 5 yr than forest 585 ppm. P available most low 58.1 ppm happens on 4 yr afters is compacted and p available forest 53.9 ppm. Nutrient content B, Cu and Zn at soil not influenced by compaction. Fosfor (P) in water increases with added years after compaction lower at 39.1 mg/L in the block without compaction compare of forest that 40.8 mg/L. Leaf nutrient rate on compacted block on optimum until excess where N (2. 69 – 3.15 %) , P (0. 170 – 0.209 %) , K( 0. 952 – 1.11%) , Mg ( 0. 377 – 0.497%) , except on block without compacting K (0. 830 %) and Mg (0. 190%) at deficiency and 0 years afters compaction Mg leaf on level deficiency 0. 230%. Nutrient content of B, Cu and Zn at various level and not influenced by compacting.

Oxygen Consumption and Sulfate Reduction in Vegetated Coastal Habitats: Effects of Physical Disturbance

Vegetated coastal habitats (VCHs), such as mangrove forests, salt marshes and seagrass meadows, have the ability to capture and store carbon in the sediment for millennia, and thus have high potential for mitigating global carbon emissions. Carbon sequestration and storage is inherently linked to the geochemical conditions created by a variety of microbial metabolisms, where physical disturbance of sediments may expose previously anoxic sediment layers to oxygen (O2), which could turn them into carbon sources instead of carbon sinks. Here, we used O2, hydrogen sulfide (H2S) and pH microsensors to determine how biogeochemical conditions, and thus aerobic and anaerobic metabolic pathways, vary across mangrove, salt marsh and seagrass sediments (case study from the Sydney area, Australia). We measured the biogeochemical conditions in the top 2.5 cm of surface (0–10 cm depth) and experimentally exposed deep sediments (>50 cm depth) to simulate undisturbed and physically exposed sediments, respectively, and how these conditions may affect carbon cycling processes. Mangrove surface sediment exhibited the highest rates of O2 consumption and sulfate (SO42-) reduction based on detailed microsensor measurements, with a diffusive O2 uptake rate of 102 mmol O2 m-2 d-1 and estimated sulfate reduction rate of 57 mmol Stot2- m-2 d-1. Surface sediments (0–10 cm) across all the VCHs generally had higher O2 consumption and estimated sulfate reduction rates than deeper layers (>50 cm depth). O2 penetration was <4 mm for most sediments and only down to ∼1 mm depth in mangrove surface sediments, which correlated with a significantly higher percent organic carbon content (%Corg) within sediments originating from mangrove forests as compared to those from seagrass and salt marsh ecosystems. Additionally, pH dropped from 8.2 at the sediment/water interface to <7–7.5 within the first 20 mm of sediment within all ecosystems. Prevailing anoxic conditions, especially in mangrove and seagrass sediments, as well as sediment acidification with depth, likely decreased microbial remineralisation rates of sedimentary carbon. However, physical disturbance of sediments and thereby exposure of deeper sediments to O2 seemed to stimulate aerobic metabolism in the exposed surface layers, likely reducing carbon stocks in VCHs.

Issues related to wetland delineation of a Texas, USA bottomland hardwood forest

Methods of wetland delineation require presence of three parameters: hydric soils, wetland hydrology, and hydrophytic vegetation. Currently accepted methods to assess these parameters often have inconsistent agreement among the parameters in bottomland hardwood forested wetlands. This study characterized soil morphology, hydrology, and vegetative composition in a bottomland hardwood forest in east Texas, USA. Alternate methods for assessment of the three parameters were examined with the aim of determining if there is an approach that provides better agreement among parameters than methods in current use. We compared four methods for determining dominance ratios and a prevalence index to assess the status of vegetation. The most stringent method of assessment and the method that provided best agreement with soil and hydrology parameters at this site was a prevalence index. We compared three criteria to assess the hydrology parameter: (1) length of growing season as defined by air temperature greater than −2°C (28°F) vs. 0°C (32°F), (2) saturation or inundation for 5% vs. 12.5% of the growing season, and (3) saturation to within 30 cm vs. 15 cm of the soil surface. Length of growing season had little or no effect on the outcome at this site; duration of required hydrology had the greatest influence over agreement with vegetation and soil parameters. We also compared the field method used to determine presence of hydric soil when sampling was conducted in 1995 with currently used field indicators. The combination that, in general, provided better agreement among the three parameters at this site was saturation to within 15 cm of the surface for 12.5% of the growing season, using current field indicators for hydric soil. Despite having been mapped as a wetland by the National Wetlands Inventory, under current federal guidelines, most of this bottomland hardwood forest would not be a jurisdictional wetland as defined by Clean Water Act regulations.

Tales of the Venerable Honolulu Tide Gauge*

AbstractSurface expressions of internal tides constitute a significant component of the total recorded tide. The internal component is strongly modulated by the time-variable density structure, and the resulting perturbation of the recorded tide gives a welcome look at twentieth-century interannual and secular variability. Time series of mean sea level hSL(t) and total recorded M2 vector aTT(t) are extracted from the Honolulu 1905–2000 and Hilo 1947–2000 (Hawaii) tide records. Internal tide parameters are derived from the intertidal continuum surrounding the M2 frequency line and from a Cartesian display of aTT(t), yielding aST = 16.6 and 22.1 cm, aIT = 1.8 and 1.0 cm for surface and internal tides at Honolulu and Hilo, respectively. The proposed model aTT(t) = aST + aIT cosθIT(t) is of a phase-modulated internal tide generated by the surface tide at some remote point and traveling to the tide gauge with velocity modulated by the underlying variable density structure. Mean sea level hSL(t) [a surrogate for the density structure and hence for θIT(t)] is coherent with aIT(t) within the decadal band 0.2–0.5 cycles per year. For both the decadal band and the century drift the recorded M2 amplitude is high when sea level is high, according to δaTT = O(0.1δhSL). The authors attribute the recorded secular increase in the Honolulu M2 amplitude from aTT = 16.1 to 16.9 cm between 1915 and 2000 to a 28° rotation of the internal tide vector in response to ocean warming.

A straight-line motion tracking control of hydraulic excavator system

The Cartesian control of automated excavators has been noted for its difficulty, especially due to severe nonlinearities in hydraulic actuators, which are hardly observed in electric motors. The nonlinearities tend to become even more severe as the size of an excavator increases and the speed of end-effector becomes faster, and conventional controls have been unable to adequately handle nonlinearities to this degree. In a conviction that modern robust controls can resolve this problem, we approached this problem by adopting Time-delay control (TDC) as the baseline control, and by enhancing it with compensators on the basis of insights obtained from the plant dynamics. The resulting control law has been applied to straight-line motions of a 13 ton hydraulic excavator with a bucket (end-effector) speed of 0.5 m/s, a speed level at which skilful operators work. The accuracy achieved was mostly within 3 cm for surfaces with various inclinations and over broad ranges of joint motions, which is far better than that of an expert operator. These promising results not only justify our approach to this problem, but also convince us that we now have an effective means for the control of automated excavator systems.

THE CONCEPT OF GELIC MATERIALS IN THE NEW GELISOL ORDER FOR PERMAFROST-AFFECTED SOILS

By taxonomic definition, soils in the recently adopted Gelisol order in Soil Taxonomy must contain permafrost within 100 cm of the soil surface or gelic materials within 100 cm of the surface and permafrost within 200 cm of the surface. Five pedons representative of Gelisols are used to illustrate the nature and properties of gelic materials. Gelic materials may be either mineral or organic and are affected by cryoturbation(frost churning), ice segregation, and/or thermal contraction cracking. Gelic materials may occur in any horizons of the active (seasonally frozen) layer and/or the upper permafrost. Cryoturbation is manifested by irregular and broken horizons, involutions, organic matter accumulation on top of and within the permafrost, oriented coarse fragments, and silt-enriched layers. Ice segregation is manifested by ice crystals, ice lenses, vein ice, and ice wedges. Thermal cracks may be filled with ice or soil material. In surface mineral horizons, gelic materials contain granular, platy, and vesicular structures; subsurface horizons have blocky and prismatic structures or structureless, massive conditions. There are distinct soil fabrics in gelic materials that are visible in thin sections, e.g., orbiculic, suscitic, conglomeric, banded, and granulitic, that reflect the cryopedogenic processes of cryodesiccation, displacement, and pore formation. Cryopedogenic processes that lead to gelic materials are driven by the physical volume change of water to ice, moisture migration along a thermal gradient in the frozen system, or thermal contraction of the frozen material by continued rapid cooling.

Soil quality standards for reclaimed coal-mine disturbed lands: A discussion paper

ABSTRACT Soil compaction and soil contamination are two common causes of land degradation on sites reclaimed after surface coalmining. Since land degradation is more easily prevented than cured, soil quality standards designed to focus land reclamation agencies on potential problems, supported by a system of sustained post-project land quality inspection and enforcement, may be the best route to underwriting the long term productivity of reclaimed lands. This paper opens discussion on the determination of appropriate measures of soil quality. It has three foci: soil physical structure, soil acidity, and soil contamination by heavy metals. It is suggested that successfully reclaimed land should have soil bulk densities that do not exceed 1.6 g/cm3 within 50 cm of the surface and 1.8 g/cm3 within 100 cm. Further, successfully reclaimed lands should have a soil pH which does not exceed the bounds pH (3.0) 3.5 - 8.5 (9.0) within 150 cm of the soil surface. Trigger concentrations for the recognition of heavy metal contamination are suggested. Particular attention should be given to the metals most frequently associated with human health problems: cadmium, lead, and to a lesser extent arsenic, mercury, and radionuclides such as uranium. Since many problems associated with soil decline build up over time, it is proposed that these conditions should obtain through inspection tests conducted at reclamation, then 10 and 20 years subsequently. It is emphasised that all of the guideline levels proposed are arbitrary. The inter-relationships between bulk density, soil acidity, heavy metal contamination, and other aspects of the soil system are complicated and, in most cases, not entirely determined by the research community.

Water Table Characteristics and Water Chemistry of Seasonally Wet Soils of Southwestern Ohio

AbstractThe seasonally high water table in Clermont (Typic Glossaqualfs) and Avonburg (Aeric Fragiaqualfs) soils of southwestern Ohio was investigated by monitoring variations in water table depth and in water chemistry of the vadose and upper saturated zones. Piezometers were installed for two pedons at three depths ranging from 70 to 180 cm, and soil‐water samples were collected using 0.1‐MPa porous ceramic cups installed in triplicate at four depths ranging from 32 to 170 cm. During the period of this study (April 1982–June 1983), the water table occurred within 30 cm of the surface during winter and early spring, fell rapidly to a depth of about 150 to 180 cm during late summer and early fall, and then returned to within 30 cm of the soil surface during late fall and early winter. Soil‐water exhibited ranges in pH (5.2–8.6), Eh (153–543 mV), electrical conductivity (7.0–91.5 mS m−1), dissolved O2 (0.6–6.1 mg L−1), Ca (2.5–64.1 mg L−1), Fe(II) (0–3.87 mg L−1), and Fe(III) (0–11.48 mg L−1). Soil‐water chemistry was a function of season and depth below the soil surface. While the dissolved O2 content decreased with depth, Eh and pH increased. Alternating periods of reduction and oxidation were suggested by significant seasonal variation in the variables monitored. Reducing conditions were indicated by the presence of Fe(II) in solution and an Eh of &lt;400 mV, both of which occurred in the Clermont soil at the uppermost sampling depth during the April through June period. This period was characterized by saturated conditions and a soil temperature higher than 8°C. The highly variable Fe(II) and Fe(III) contents indicated that oxidation‐reduction reactions occurred primarily in microenvironments. The soil‐water system was not at internal equilibrium as evidenced by (i) the simultaneous occurrence of dissolved O2 with reduced C (organic matter) and Fe (II), and (ii) a mixed potential for Eh that did not correlate with dissolved O2 content.

Analysis of Long‐Term Water Table Depth Records from a Hydrosequence of Soils in Central Ohio

AbstractWater table depths and precipitation were measured over a 10‐yr period on four adjacent forested soils in central Ohio. The soils included a hydrosequence of well, moderately well, poorly, and very poorly drained fine‐textured soils. Graphs describing the probability of observing water tables during consecutive 2‐week (semi‐monthly) intervals, by soil depth class, were compared with estimates reported on USDA‐Soil Conservation Service forms SOIL‐SOI‐5 and a method proposed in the Soil Survey Manual. All soils had a probability of an observed water table within 50 cm of the soil surface. Water tables were observed in all soils, with the exception of the well drained soil, within 25 cm of the surface, 10% of the time or more, over a 12‐ or 14‐week period in the late winter and spring.

Prolonged Triboluminescence in Clays and Other Minerals

Samples of various clays and minerals were ground or fractured and monitored with a liquid scintillation spectrometer in order to obtain triboluminescent decay curves. Kaolinite samples displayed several million counts/min after grinding, with a surface area emission estimated at tens of billions of photons/sq cm of surface. The photon production rates varied with the origin of the sample, and kaolinite continually yielded higher production rates than bentonite. The addition of water to the samples slightly increased the count rate of emitted light, while the addition of the fluorescent molecule substance tryptofan significantly enhanced the count rate. Freezing smears of kaolinite and montmorillonite in liquid nitrogen and in a salt ice mixture also induced triboluminescence in the montmorillonite. A possible connection between powdery triboluminescent materials formed in mining industries and respiratory disorders among miners is suggested.

Effects of Topsoil and Subsoil Thickness on Soil Water Content and Crop Production on a Disturbed Soil1

Data by which we can quantify effects of soil depth upon productivity from controlled experiments are essentially lacking for semiarid regions. In connection with mined land-reclamation research in North Dakota, an experiment was established in which soil was reconstructed by building a wedge with productive subsoil (B and upper C horizon) on top of leveled sodic mine spoils derived from shale. Thickness of the subsoil wedge ranged from 0 to 210 cm. Topsoil (A horizon) was then spread over the subsoil wedge to provide a topsoil either 0, 20, or 60 cm thick. A fourth treatment consisted of mixing subsoil and topsoil within the wedge in a 3:1 ratio (no topsoil on the surface). Four crops—alfalfa (Medicago sativa L.), crested wheatgrass (Agropyron desertorum), native warm-season grasses (Bouteloua gracilis and Bouteloua curtipendula), and spring wheat (Triticum aestivum L.)—were grown each year on these plots from 1975 through 1979. Yields of all crops increased as total soil thickness (topsoil plus subsoil) increased to the 90- to 150-cm range. Highest yields equaled or exceeded yields that would be expected in these years on similar undisturbed soil types under good management in the same county. In most instances, over 90% of the maximum yields observed was obtained when 70 cm of subsoil plus 20 cm of topsoil covered the sodic spoils (SAR = 25, clay = 38%). Yields from 60 cm of topsoil were similar to those from 20 cm of topsoil. With no topsoil, only native grama grasses produced over 75% of maximum, but all crops except wheat produced at least 90% of maximum with at least 90 cm of the mixed subsoil-topsoil spread over spoils (wheat yields were only about 80% of maximum). Water was extracted from the upper 30 to 90 cm of spoils when the soil-spoil interface was within 90 cm of the soil surface. Thickness of topsoil had no influence on depth of water extraction. Alfalfa extracted water to about 135 cm if sodic spoils were within 90 cm of the surface and to about 175 cm where spoils were covered with at least 150 cm of soil materials. Depth of water extraction by crested wheatgrass under these two situations was about 120 and 150 cm; by native grasses about 80 and 120 cm; and by spring wheat about 75 and 90 cm, respectively. There was no evidence of any accumulation of soil water just above the soil-spoil interface under any situation.

Depth distribution of photosynthetic activity in a Myriophyllum, spicatum community in Lake Wingra1

Photosynthetic rates and productivity of Myriophyllum spicatum L. were examined in the littoral by incubating shoot sections at three rooting depths using a 14C technique. At a rooting depth of 240 cm, the interrelation of biomass and photosynthetic rates resulted in the production of 56% of the total photosynthetic productivity within 100 cm of the water surface in May. In August, 57% of the total productivity occurred within only 20 cm of the surface. Variations in the depth distribution of biomass, due to differing growth and sloughing patterns, resulted in different depth relations of photosynthesis at the other rooting depths. Light extinction and light adaptation of photosynthetic tissues were other factors determining the depth relations of photosynthesis.

A Statistical Theory of Liquids. II

In continuation of Part I, vapor pressure, surface tension, and the neighborhood of the critical point are discussed. Section IX deals with the vapor pressure law. A comparison with experimental data shows that the experimental values of the heat of vaporization are, on the average, 55 percent higher than the calculated values for the ten liquids studied. This suggests association in the liquid phase. However, even for the noble gases and mono-atomic metal vapors there remains a discrepancy, though of less degree. In Section X the previously established expression for the surface tension is developed. The "number of molecules per sq. cm of surface" can be defined by the aid of integrals involving the potential of molecular interaction. If, then, a "molar surface ${S}^{*}$," is defined as a surface containing one mole of the liquid, the equation of state for the surface phase assumes the form $\ensuremath{\gamma}{S}^{*}=RT$. The value for mercury can be calculated quantitatively from the potential as established in Part I. In the case of the other nine liquids the potential has to be "cut off" at a distance of the order ${\ensuremath{\sigma}}_{1}$. E\"otv\"os' law follows as a limiting law for sufficiently high temperatures.---In Section XI the potential in the surface layer is supplemented for the case that the density in the vapor phase becomes comparable with that in the liquid phase. Then the proof of the coexistence of the two phases (Section IV) is extended to the neighborhood of the critical point. For that neighborhood the rule of Cailletet and Mathias is deduced. Finally the Kamerlingh Onnes constant is deduced from the special form of potential introduced in Section VII. It comes out 25 to 33 percent too low.

The Spectrum Analysis of the Hot Carbon Star, R Coronae Borealis

view Abstract Citations (37) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Spectrum Analysis of the Hot Carbon Star, R Coronae Borealis Berman, Louis Abstract A detailed investigation of the spectrum of the irregular variable R Coronae Borealis, in the region XX 4300-4900 was undertaken for the purpose of studying the physical conditions of its atmosphere. The wave-lengths of approximately 6~o lines were measured on the Lick three-prism spectrograms and the corresponding elements identified. Only 2 per cent of the lines belong to the non-metals. The average radial velocity of the system is + 25.1 km/sec. and is slightly variable at the time of maximum light (6.o mag.). A calibration-curve, based upon the theoretical intensity ratios of supermultiplets, connects the observed line intensities and the absolute numbers of atoms engaged in their production. The chemical composition of the atmosphere is found to be 69 per cent carbon, 27 per cent hydrogen, less than 0.3 per cent nitrogen, and 4 per cent metals. (chiefly magnesium and iron). (The theoretical abundance of the carbon molecule, C2, whose appearance is feebly indicated by the Swan spectrum, is 0.00003 per cent.) With these compositions and the value of the general atomic absorption coefficient derived from wave-mechanics, the computed optical depth of the photospheric level is o.oo6. This improbably small value may result from the incomplete state of the theory at the present time and from the neglect of molecular opacity arising from dissociation. The Russell-Adams analysis, used to determine the absolute temperature, does not reveal any marked deviation from thermodynamic equilibrium up to an excitation po- tential of io volts. The energy distribution of the continuous spectrum leads to a higher color temperature in the red than in the blue, but the difference may arise from the diffi- culty of drawing the true continuous background, owing to the peculiarity of the spec- trum. The color temperature in the blue is found to be over 10000 higher than the effective temperature. Finally, the physical parameters that define the state of the atmosphere are pre- sented: spectral class, cF7p; effective temperature, 53000 K; color temperature, 6700° K (XX 3500-4500), 77000 K (XX 4500-6500); electron pressure at base of reversing layer, 8.3XIo7 atm., mean total pressure, 9.3X io~ atm.; level of ionization, 9.6 volts; surface gravity, 2.7X 102 cm/sec.2; mean molecular weight, io chemical units; velocity of turbulence, io km/sec.; number of neutral atoms above i sq. cm of surface, 4.4X 1Q21, corresponding number of ionized atoms, 2.3 X 1020, corresponding total number of all particles, 4.9X 1021. 36 Publication: The Astrophysical Journal Pub Date: June 1935 DOI: 10.1086/143644 Bibcode: 1935ApJ....81..369B full text sources ADS |