Capillary End Effects in Reservoirs with Heterogeneous Wettability

Doklady Earth Sciences - A new type of capillary end effect in oil and gas reservoirs due to heterogeneous wettability has been justified. This type of capillary end effect is not related to the...     

Efficacy of Selected Compounds on Thermocyclops oblongatus,one of the Main Intermediate Hosts of Guinea Worm in Africa

Ten selected compounds were tested on Thermocyclops oblongatus to determine their ability to be used for treatment of drinking water sources. None were shown to be interesting for individual application in household water tanks. Tested compounds, such as potassium permanganate or chlorine-releasing products, were ineffective or affected dramatically the taste or colour of the water. For collective application in water sources, temephos appeared to be the most valuable pesticide because it was effective against cyclops and harmless for environment. Other pesticides should be proposed as substitutes in case of cyclops resistance to temephos.     

An ephemeral turbidity maximum generated by resuspension of organic-rich matter in a macrotidal estuary, S.W. Wales

An ephemeral estuarine turbidity maximum (ETM) occurs at high water in the macrotidal Taf estuary (SW Wales, United Kingdom). A new mechanism of ETM formation, due to resuspension and advection of material by flood tidal currents, is observed that differs from classical mechanisms of gravitational circulation and tidal pumping. The flood tide advances across intertidal sand flats in the main body of the estuary, progressively entraining material from the rippled sands. Resuspension creates, a turbid front that has suspended sediment concentrations (SSC) of about 4,000 mg I⁻¹ by the time it reaches its landward limit which is also the landward limit of salt penetration. This turbid body constitutes the ETM. Deposition occurs at high slack water but the ETM retains SSC values up to 800 mg I⁻¹, 1–2 orders of magnitude greater than ambient SSC values in the river and estuarine waters on either side. The ETM retreats down the estuary during the ebb; some material is deposited thinly across emergent intertidal flats and some is flushed out of the estuary. A new ETM is generated by the next flood tide. Both location and SSC of the ETM scale on Q/R³ where Q is tidal range and R is river discharge. The greatest expression of the ETM occurs when a spring tide coincides with low river discharge. It does not form during high river discharge conditions and is poorly developed on neap tides. Particles in the ETM have effective densities (120–160 kg m⁻³) that are 3–4 times less than those in the main part of the estuary at high water. High chlorophyll concentrations in the ETM suggest that flocs probably originate from biological production in the estuary, including production on the intertidal sand flats.     

Thermal features at Volcanoes in the cascade range,as observed by aerial infrared surveys

There have been no substantial changes in the thermal patterns at the summit of Mount Rainier in the period September 1964–September 1966, within the detection limits of the infrared instrumentation. Some differences in radiance are attributed to differences in snow cover. The highest apparent temperature is at a snow-free area on the west flank of the summit cone, several hundred feet below the west crater rim. An anomaly at this site was recorded on both infrared surveys, but no prior reports of thermal activity here have been made by ground parties. Other anomalous thermal zones at the summit are on the northern quadrants of both crater rims. A very small, low-temperature fumarole reported on Mount Adams was not detected, nor were any other thermal manifestations recorded. One anomaly consisting of a close-spaced cluster of thermal spots was detected at The Boot on Mount St. Helens and corresponds to a known fumarole area. The only thermal feature seen on Mount Shasta is near the summit at a thermal spring that has been observed by many climbers. Two anomalies were found on the north flank of Lassen Peak. Thermal activity had not been previously reported at either site, though one is in a known solfatarized area. No ground investigation has been made at the other location. Much of the other thermal activity in the Lassen Peak area is in the northeast quadrant of Brokeoff Caldera. Most of these features are well documented in the literature; others not previously described are in fairly accessible areas and doubtless result from springs and fumaroles related to Brokeoff Caldera.