Floor Cover Research Articles

A palynological investigation across the Jurassic-Cretaceous boundary on the south-east flanks of Mount Hermon, Israel

The disconformable contact across the Jurassic-Cretaceous boundary on the south-east flanks of Mount Hermon, Israel was studied palynologically. The youngest Jurassic sediments (Beer-Sheva and Haluza Formation J6-J7) are of late Oxfordian age. Miospores, probably of (?late) Berriasian age, were discovered within sediments in a volcanic sequence, the E’Shatr sequence, above the contact, and are considered to be the oldest Cretaceous fossils in northern Israel. Overlying clastic sediments (basal Hatira Formation, ‘Nubian Sandstone’ equivalent) previously thought to be devoid of fossils yielded miospores and dinoflagellate cysts deposited during a transgressive pulse of probable late Barremian age. The new combination of the spore species Biretisporites aegyptiacanov. comb. is proposed. The palynomorphs studied are used to correlate the lithostratigraphic units above and below the Jurassic-Cretaceous boundary in northern Isreal with other parts of the Middle East (northern Gondwana, Tethyan realm) and western Europe (Laurasia, Boreal realm). The oldest known Cretaceous miospores in Israel were discovered in a terrestrial sequence barren of other fossils. They indicate a continental environment of deposition which supported a forest cover of conifers, tree-ferns and lycopsid epiphytes, and a pteridophytic floor cover that indicates moist climatic conditions.

House dust mite allergen levels in dust from schools with smooth and carpeted classroom floors.

A study was conducted to investigate the levels of house dust mite allergen Der p I in classroom floor dust from 49 schools with smooth (n = 18) or carpeted (n = 31) floors. Schools were located in the city of Rotterdam (n = 29) and in a number of small communities in the Province of Gelderland (n = 20). Data on building characteristics of the schools were obtained. Dust samples were analysed for Der p I content, the major allergen of the house dust mite Dermatophagoides pteronyssinus. The results showed that in schools with carpeted classroom floors, larger amounts of settled dust and higher Der p I levels either expressed as concentrations (in ng/g) or loadings (in ng/m2) were found than in schools with smooth classroom floors. However, the levels of Der p I were considerably lower than in dust collected from floors in homes. Although the Der p I levels were low, effects of several building characteristics on the levels were found. Age of the floor cover, the number of classrooms in the school and the presence of damp spots in the building were related to Der p I concentrations and loadings mainly on carpeted floors. Remarkably, schools in the rural area contained significantly more dust and Der p I than schools in the urban area. We conclude that dust from carpeted classroom floors contains more house dust mite allergen than dust from smooth classroom floors, but much less than dust from floors in homes.

Radon 222 tracing of soil and forest canopy trace gas exchange in an open canopy boreal forest

A set of continuous, high‐resolution atmospheric radon (222Rn) concentration time series and radon soil flux measurements were acquired during the summer of 1990 at a micrometeorological tower site 13 km northwest of Schefferville, Quebec, Canada. The tower was located in a dry upland, open‐canopy lichen‐spruce woodland. For the period July 23 to August 1, 1990, the mean radon soil flux was 41.1±4.8 Bq m−2 h−1. Radon surface flux from the two end‐member forest floor cover types (lichen mat and bare soil) were 38.8±5.1 and 61.8±15.6 Bq m−2 h−1, respectively. Average total forest canopy resistances computed using a simple “flux box” model for radon exchange between the forest canopy and the overlying atmosphere range from 0.47±0.24 s cm−1 to 2.65±1.61 s cm−1 for daytime hours (0900–1700 LT) and from 3.44±0.91 s cm−1 to 10.55±7.16 s cm−1 for nighttime hours (2000–0600) for the period July 23 to August 6, 1990. Continuous radon profiling of canopy atmospheres is a suitable approach for determining rates of biosphere/atmosphere trace gas exchange for remote field sites where daily equipment maintenance is not possible.

A212 ムービングベルト付風洞を用いた自動車模型回りの5孔ピトー管サーベイ

The cross flow vector, total pressure loss and microdrag maps around 1/5 scale passenger car models are visualized by flow surveys with 5-hole pitot tubes in a scale wind tunnel with a moving belt. Five passenger car shapes, that is, a notch-back, a sedan, a sedan with under floor cover, a first-back, and a wagon are examined and survey data are obtained in the cross sections in the wake, under the floor, and beside the car. These data are calculated and presented as color contour maps with the car shapes from CAD data. The survey around the car clarifies the effect of the belt movement, and that the microdrag map in the near wake can indicate the part of the body shape which produces the large portion of the drag.

Heat Balance Characteristics in a Fan-ventilated Plastichouse

Continual measurement of energy fluxes in a fan-ventilated plastichouse had been carried out during the growing season of melon crops. The equations to estimate the ventilation rate were derived from the experimental results.The experimental plastichouse had a floor area of 200m2. A fan with a capacity of 320m3 min-1 at the gauge pressure of 1.5mmAq was used to ventilate the plastichouse. Two different mulch conditions were examined; one without mulch and the other with 80% of the floor area covered. The experiment was conducted from April to June, 1977.Inside net radiation and soil heat flux were measured with a net radiometer and heat flux plates, respectively. Both sensible and latent heat flux due to ventilation were calculated from the ventilation rate and the dry and the wet bulb temperatures measured inside and outside the plastichouse. Heat transmission through glazing was estimated from the inside-outside temperature difference and the heat transmission coefficient.1. The ratio of latent heat flux to inside net radiation increased with the increase in LAI. The mean value of the ratio for LAI more than 1 was 55.1% when the floor was not covered with mulch, while 52.6% when 80% covered.2. Sensible heat flux due to ventilation gradually decreased with the increase in LAI. The mean ratio to net radiation for LAI more than 1 was 32% when not covered, while 36% when 80% covered To maintain the same inside air temperature, therefore, it is estimated that more ventilation rate is required when the floor is covered than the case when not covered.3. When LAI was small, sensible heat flux due to ventilation exceeded latent heat flux, while it was reverse when LAI was large. This change occurred at LAI equale to 0.4 when the floor was not covered, but at LAI of 0.7 when 80% covered.4. Heat transmission through glazing was also affected by the floor cover. Its ratio to the inside net radiation was averagely 7% when not covered, while 8.9% when 80% covered.5. Soil heat flux was less dependent on the floor cover, but more on LAI. Namely, the flux decreased as LAI increased. The average ratio during the growing season was 6%.6. Bowen ratio in the ventilation heat fluxes at LAI of 0.08 was 1.44 without floor cover and 2.77 with mulch. These ratios decreased with the increase in LAI.7. The following equations to estimate the ventilation rate was derived experimentally from the energy balance measurement.In case without mulch, q=1/cpρ(0.437aSi/ti-to-wk)In case 80% of the floor covered, q=1/cpρ(0.481aSi/ti-to-wk)where, q; ventilation rate, cp; specific heat of air, ρ; air density, a; ratio of sunlit area to total floor area, Si; inside net radiation, ti; inside air temperature, to; outside air temperature, w; floor to glazing area ratio, k; heat transmission coefficient of glazing.

Metallogenesis in Southeast Pacific Ocean: Nazca Plate Project: ABSTRACT

The Nazca Plate Project is a detailed and systematic geological, geochemical, and geophysical investigation of a distinct and tectonically active lithospheric plate of the southeast Pacific Ocean basin. Major tectonic boundaries of the Nazca plate are defined by the East Pacific Rise on the west, along which new oceanic crust of basalt is being generated; the Peru-Chile Trench on the east, where older oceanic crust is being consumed by subduction beneath the overriding South American plate; and the Galapagos spreading center and the Chile Rise on the north and south, respectively. The motion of this plate relative to the Pacific plate is estimated to be eastward at more than 16 cm/yr, as documented by stratigraphic, structural, paleontologic, magnetic, and seismic evidenc . Normal sediments of the deep-sea floor cover basaltic basement rocks over much of the plate, but are locally dominated by a metal-rich component on and near the East Pacific Rise and within the Bauer Deep. These metalliferous sediments, which are composed of crystalline ferromanganese hydroxyoxides (goethite, psilomelane, etc) and Fe-montmorillonite, contain anomalously high concentrations of Fe, Mn, Cu, Ni, Zn, and other transition metals. Elemental abundances and ratios, extraordinary high rates of sedimentation, lead-isotope ratios, and statistical analysis of the data suggest that Fe, Mn, Cu, and possibly other metals were deposited by hydrothermal fluids emanating from sources of basaltic magmatism along the East Pacific Rise. However, isotopic abundances of O, Sr, S, and C and di tribution patterns of the rare-earth elements imply that deposition of the metalliferous sediments occurred at normally low temperatures of the ocean floor and that the nonmetallic components were derived from and/or equilibrated with seawater.