Dripping Water Research Articles

Forty years of epikarst: what biology have we learned?

Epikarst is not only an important component of the hydrogeology of karst and an active site of speleogenesis, it is habitat for a number of species adapted to subterranean life. Water in epikarst, with a residence time of days to months, is a highly heterogeneous habitat, and the animals are primarily sampled from continuously sampling dripping water or collecting from residual drip pools. While the subterranean fauna of cracks and crevices has been known for over 100 years, it is only in the past several decades that epikarst has been recognized as a distinct habitat, with reproducing populations of stygobionts. Dissolved organic carbon in epikarst drip water is a primary and sometimes the only source of organic matter for underlying caves, especially if there are not sinking streams that enter the cave. Typical concentrations of organic carbon are 1 mg L -1 . The fauna of epikarst is dominated by copepods, but other groups, including some terrestrial taxa, are important in some areas. Most of the diversity is β-diversity (between drips and between caves). In Slovenia, an average of nearly 9 stygobiotic copepod species were found per cave. In studies in Romania and Slovenia, a number of factors have been found to be important in determining species distribution, including ceiling thickness, habitat connectivity and habitat size. In addition to eye and pigment loss, epikarst copepod species may show a number of specialization for life in epikarst, including adaptations to avoid displacement by water flow. Several geoscientists and biologists have challenged the uniqueness and importance of epikarst, but on balance the concept is valid and useful. Fruitful future research directions include development of better sampling techniques, studies to explain differences among nearby epikarst communities, phylogeographic studies, and assessing the possible role of copepods as tracers of vadose water. adaptation; cave ecology; Copepoda; stygobionts; subterranean biodiversity

Zinc phosphate dissolution by bacteria isolated from an oligotrophic karst cave in central China

Biogeochemical processes are fundamental to sustain the ecosystem in subsurface caves, but to date they are still far from well understood. To investigate microbially mediated phosphorus and zinc cycles, we isolated three bacterial strains from the dripping water in Heshang cave, central China, identified as Exiguobacterium aurantiacum E11, Pseudomonas fluorescens P35, and Pseudomonas poae P41, respectively. Microbial capabilities in the dissolution of phosphorus-containing minerals were tested with zinc phosphate (Zn3(PO4)2) in batch culture at 30°C. A spectrophotometer, atomic absorption spectrum, and scanning electronic microscopy were used to measure the microbial growth, soluble Zn(II) concentration, and to observe the morphology of Zn3(PO4)2 before and after microbial dissolution. P. fluorescens and P. poae, the well-known phosphorus solubilizing bacteria (PSB), are observed to solubilize Zn3(PO4)2 with an efficiency of 16.7% and 17.6%, respectively. To our knowledge, E. aurantiacum is firstly reported in this study to dissolve phosphorous-containing minerals with a higher efficiency of 39.7%, expanding our understanding about the ubiquitous occurrence of PSB in natural environments. Aqueous Zn(II) concentration positively correlates with H+ activity, confirming the presence of acidification mechanisms widely exploited by PSB. Few itching pits were observed on the surface of Zn3(PO4)2 after microbial dissolution, inferring that microbial dissolution is not always associated with the direct contact with minerals. Even though the soluble Zn(II) concentration reached up to 370 mg/L in the system inoculated with E. aurantiacum E11, inhibition of microbial growth was not detected by spectrophotometer. Our laboratory data revealed the importance of microbially-mediated P and Zn cycles in the subsurface ecosystem.

Blood drop size in passive dripping from weapons

Passive dripping, the slow dripping of blood under gravity, is responsible for some bloodstains found at crime scenes, particularly drip trails left by a person moving through the scene. Previous work by other authors has established relationships, under ideal conditions, between the size of the stain, the number of spines and satellite stains, the roughness of the surface, the size of the blood droplet and the height from which it falls. To apply these relationships to infer the height of fall requires independent knowledge of the size of the droplet. This work aims to measure the size of droplets falling from objects representative of hand-held weapons. Pig blood was used, with density, surface tension and viscosity controlled to fall within the normal range for human blood. Distilled water was also tested as a reference. Drips were formed from stainless steel objects with different roughnesses including cylinders of diameter between 10 and 100mm, and flat plates. Small radius objects including a knife and a wrench were also tested. High speed images of the falling drops were captured. The primary blood drop size ranged from 4.15±0.11mm up to 6.15±0.15mm (depending on the object), with the smaller values from sharper objects. The primary drop size correlated only weakly with surface roughness, over the roughness range studied. The number of accompanying droplets increased with the object size, but no significant correlation with surface texture was observed. Dripping of blood produced slightly smaller drops, with more accompanying droplets, than dripping water.

Manifold learning approach for chaos in the dripping faucet

Dripping water from a faucet is a typical example exhibiting rich nonlinear phenomena. For such a system, the time stamps at which water drops separate from the faucet can be directly observed in real experiments, and the time series of intervals τn between drop separations becomes a subject of analysis. Even if the mass mn of a drop at the onset of the nth separation, which is difficult to observe experimentally, exhibits perfectly deterministic dynamics, it may be difficult to obtain the same information about the underlying dynamics from the time series τn. This is because the return plot τn-1 vs. τn may become a multivalued relation (i.e., it doesn't represent a function describing deterministic dynamics). In this paper, we propose a method to construct a nonlinear coordinate which provides a "surrogate" of the internal state mn from the time series of τn. Here, a key of the proposed approach is to use isomap, which is a well-known method of manifold learning. We first apply it to the time series of τn generated from the numerical simulation of a phenomenological mass-spring model for the dripping faucet system. It is shown that a clear one-dimensional map is obtained by the proposed approach, whose characteristic quantities such as the Lyapunov exponent, the topological entropy, and the time correlation function coincide with the original dripping faucet system. Furthermore, we also analyze data obtained from real dripping faucet experiments, which also provide promising results.

Condensation Dripping Water Detection and Its Control Method from Exhaust Pipe of Gasohol Vehicle under Low Environmental Temperature Conditions: A Case Study in Harbin, China

Gasohol is one of renewable clean alternative energies, which is widely used around the world. Gasohol had been raised to be used in 9 provinces of China since 2001. However, its closed use was merely promoted in Heilongjiang province since November 1, 2004. Moreover, this issue aroused extensive discussions and controversies. One of them is the condensation dripping water issue from exhaust pipe in cold winter. Does the ethanol cause the road freezing in cold winter? To deal with this issue, taking the Harbin city as a case study, this work designs detection experiments of the condensation dripping water from exhaust pipe. Moreover, the amount of the condensation dripping water from exhaust pipe for gasohol and gasoline vehicles with the same working condition is obtained and measured, and their results are compared and analyzed. Simultaneously, the method of reducing the condensation dripping water is proposed. The results illustrate the effectiveness of the proposed method.

Diversity patterns of fauna in dripping water of caves from Transylvania

Recent studies substantiate the importance of the unsaturated zone in ground-water biodiversity of karst areas. Few investigations, however, have addressed the temporal changes in community composition in relation to water physico-chemical features. We provide information on the distribution pattern of the fauna in dripping water at spatial and temporal scales. This is related to variation in water chemistry and other environmental features in five caves within two hydrographic basins of the Pa˘ durea Craiului Mountains (northwestern Romania). The analysis revealed no major pollution in the dripping water. The physico- chemical parameters varied within and between caves over one year. The dripping water fauna is hetero- geneously distributed within and between the caves, containing a mixture of epigean and hypogean species. This emphasizes high microhabitat partition and also underlines the influence of physico-chemical parameters. The species composition among the two hydrographic basins was different. Crustaceans are the best represented in terms of both abundance and species richness. Six out of 15 crustacean species are endemic to the Pa˘ durea Craiului Mountains and four are new to science. All these point to the importance of unsaturated karstic habitats as biodiversity hot spots in ground-water ecosystems.

Bacteria isolated from dripping water in the oligotrophic Heshang cave in Central China

INTRODUCTION Microorganisms might show the potential to change the chemical property of the dripping water in caves (Huang et al., 2007; Zavarzin, 2002). They are also sensitive to the climate change, which might be preserved in stalagmites. It is of great significance to identify the microorganisms in the dripping water, and figure out the functions they could carry on during the stalagmite formation, favoring to decipher the microbial lipid records recovered from stalagmites. To date, only few studies were conducted concerning the biological records in dripping water (Huang et al., 2007; Zhao et al., 2007; Laiz et al., 1999). Here we show the bacteria isolated in the dripping waters of Heshang Cave in Central China by using the specifically designed oligotrophic medium, and 16S rDNA gene was sequenced to identify the isolates to investigate the possible microbial functions in the karst cave ecosystem.

Chemical characteristics of breeding sites of Culicoides species (Diptera: Ceratopogonidae)

We determined chemical characteristics of the breeding sites of Culicoides species in Turkey. Soil samples containing pupae and larvae of Culicoides species were collected between January and December 2004 and fly emergence was recorded in the laboratory. Percent organic matter, pH, electrical conductivity and mineral constituents of habitat samples were quantified to determine habitat preferences of the emerging species. A total of 1623 mature Culicoides flies comprising 10 species emerged from soil samples collected from 8 different habitat types. A total of 856 (53%) flies were recovered from habitats containing mud rich in dung near water reservoirs, 288 (18%) from mud in reed sites, 279 (17%) from mud in swamps, 78 (5%) from mud along side the streams, 39 (2.4%) from mud around dams, 38 (2.3%) from mud near dripping water, 30 (2%) from mud in rain puddles and 15 (1.0%) from moist soil. While C. nubeculosus (Meigen) and C. puncticollis (Becker) were encountered more in mud rich in dung near water reservoirs and mud in swamps; C. gejgelensis Dzhafarov and C. festivipennis Kieffer were more common in mud alongside streams. C. circumscriptus Kieffer was encountered in most habitats and no Culicoides flies emerged from livestock dung samples and tree holes. The number of C. festivipennis Kieffer was significantly correlated with organic matter, P, K and Zn while the number of C. nubeculosus (Meigen) was significantly correlated with pH, P and K.

Novel Dating Method for Speleothems with Microscopic Fluorescent Annual Layers

Terrestrial carbonate deposits with a banded layer structure can be good tools for the extraction of past environmental information on global and local scales using trace element concentrations and stable isotope ratios. The absolute age dating is most important for the reconstruction of an environmental chronicle. The measurements of fluorescent annual bandings in stalagmites using a microscopic spectrofluorometer with an XY-stage can be a convenient dating method and are especially effective for young samples whose absolute age is very difficult to be determined by other methods. The number of annual bandings was objectively counted using a personal computer. The optimal conditions for the measurements are discussed. The annual banding in stalagmites is caused by the seasonal differences in the fulvic acid concentrations in the dripping water which forms speleothems.

Copepod distribution as an indicator of epikarst system connectivity

The distribution of 27 copepod species was determined in 35 drips in four Slovenian caves (Dimnice, Postojna Planina Cave System, Skocjanske Jame, Županova Jama), and of ten species from 13 drips in one US cave (Organ Cave, West Virginia). The dripping water comes from epikarst, the skin of karst. A significant fraction of the copepod species found (nine species in Slovenia and three in West Virginia) occurred over a maximum linear extent of 100 m. These and other localized distributions probably resulted from colonization of epikarst by an ancestral surface population in a single location, with subsequent lateral spread in the direction of epikarst flow. This suggests that the distribution of copepods could potentially be used to trace major flow paths in epikarst without the need for the injection of dyes or other tracers.

Imbolc Poems

1. Imbolc easier if once having given birth the new fawn straggled off to eden so much harder to carry her with her stick legs over snowfi elds if there were a brook a fig left lying in the snow a trickle of sap from a tree to make the journey easier o lady of the well of life have pity on one who bears herself through cold winter show yourself though you dwell beneath frozen water tap the ice until it breaks 2. Festival of Trees When we went to the clearing to visit the trees, the great trees of the clearing, [End Page 75] mother, grandmother, and daughter, sister, and faithful gatekeeper, we blessed them to grow upward, to spread the wealth of earth into the air as a fan scatters a breeze across the face. But when we came to the wise crone, the old dead tree wrapped in vines, escorted by milkweed and tall grass, her we blessed to grow downward to pour her radiance back into the soil so that all would grow from her body. That day in the snow she had the face of an owl, beak and hooded eyes. Her call could not be heard. It was beneath us, under the ground. 3. Snow Queen soft and deep the magician said to me while he ate at my table in winter soft and deep is your wisdom you are snow one can walk through you your voice is dripping water one cannot hear it except in the silence between winds you are the white roof of a stone you round the world's edges you are a wall dividing earth from sky but you are earth and sky together [End Page 76] you are an avalanche you snap the boughs of birches you are a skin on earth you cover each needle of the pines you are a snowdrift no one can move you except a little at a time 4. The Feast of Brigid The red-haired girl draws milk in a pail from the earth. The earth is a spotted cow with teats that are geysers and anthills and rotten logs. The red-haired girl strokes and strokes the dark soil. When the milk rises in spurts she catches its arc of white froth to give out to visitors. At the gate of the farm the world holds out its hand, while in a field rimed with frost the first snowdrop toddles from the ground. 5. Sunna and the Wolf My pretty, I will eat you, and when I eat you you will shine so brightly within me I will tear myself open for the joy of seeing you again. [End Page 77] Then it will be dawn. The blood of my desire will paint the sky. Only you and I will know how in the night you lay in my belly and at daybreak I let you go. 6. Baubo My beloved calls you Vagina Girl. You are her hero, the goddess who speaks with the lips of her vulva, who tells jokes about misery. You are the one who backs her father's words against the wall so her body may speak. In the mists of myth you danced with a grieving mother and made her laugh. You brought the first warm breeze to earth. You are as old as the hills and as young as the need to keep living. You are the patron saint of survivors. Everyone likes you at parties and fears you for telling the truth. When I meet you and your furry ways you tickle me. I would try to become you if I could tell one punch line without crying. 7. Demeter Pauses If I do not find her there will still be mountains and melt coming off the hills in spring and the grain will feel cool and heavy in my hand as I cast it to the hungry earth and the fir boughs will touch my face [End Page...

Adsorbed silica in stalagmite carbonate and its relationship to past rainfall

Despite considerable work on other trace elements, the incorporation of dissolved silicon from cave waters into speleothems has not been previously investigated. In this study, the controls on dissolved Si in cave waters and on adsorbed Si in resulting speleothems are therefore investigated. Bedrock (dolomite), soil water, dripping water, and cave carbonates were retrieved from Heshang Cave situated in the central Yangtze valley of China and were subjected to analysis of dissolved Si content (plus accompanying Ca and Fe analyses). Soil waters have Si/Ca of 45.5 mmol/mol, compared to only 3.2 mmol/mol in the dolomite bedrock, demonstrating that >80% of the dissolved Si must come from dissolution of silicate minerals in the soil. Drip waters have a dissolved Si concentration of ≈4.2 μg/mL, similar to that in the overlying soil water. Actively growing cave carbonates have a Si/Ca of 0.075 mmol/mol suggesting a partition coefficient for incorporation of dissolved silicon of 0.0014, in good agreement with previous laboratory studies. Extrapolating the results of these laboratory studies to the cave environment suggests that changes in Si/Ca in cave carbonates are likely to be primarily controlled by changes in drip-water Si/Ca. The drip-water Si/Ca will, in turn, be controlled by the rate of wind-blown silicate supply; by soil weathering rates; by rainfall dilution; and by precipitation of calcite. The general expectation is that these effects combine to produce high Si/Ca in speleothems during times of low rainfall. A δ 18O record from a Heshang Cave stalagmite which grew between 20 and 11 thousand years ago allows these controls to be tested. Correlation of high Si/Ca with high δ 18O demonstrates that regional rainfall exerts significant (but not complete) control on speleothem Si/Ca. With further understanding, speleothem Si/Ca may provide a proxy for past rainfall to complement existing proxies such as δ 18O and Mg/Ca.

Effect of soil-rock system on speleothems weathering in Bailong Cave, Yunnan Province, China

Bailong Cave with its well-developed Middle Triassic calcareous dolomite's system was opened as a show cave for visitors in 1988. The speleothem scenery has been strongly weathered as white powder on the outer layers. Study of the cave winds, permeability of soil-rock system and the chemical compositions of the dripping water indicated: (1) The cave dimension structure distinctively affects the cave winds, which were stronger at narrow places. (2) Based on the different soil grain size distribution, clay was the highest in composition in the soil. The response sense of dripping water to the rainwater percolation was slow. The density of joints and other openings in dolomite make the dolomite as mesh seepage body forming piles of thin and high columns and stalactites. (3) Study of 9 dripping water samples by HYDROWIN computer program showed that the major mineral in the water was dolomite.

SPECIES DIVERSITY GRADIENT TO DARKNESS STRESS IN BLUE-GREEN ALGAE/CYANOBACTERIA: A MICROSCALE TEST IN A PREHISTORIC CAVE, MOUNT CARMEL, ISRAEL

Species diversity of epilithic cyanobacteria was studied in a 90 m deep prehistoric el-Wad cave eroded in Cenomanian limestones of Mount Carmel, Israel. The degree of illumination is the most variable index throughout the cave, whereas humidity and temperature vary moderately. In a number of sites inside the cave dripping water occurs due to filtration of rain water. In el-Wad cave 42 species from 20 genera of blue-green algae were found. The share of coccoid forms decreased and filamentous (especially oscillatorial) ones increased from the entrance to the end of the cave. Intensity of light was the governing factor for distribution of cyanobacteria in el-Wad cave; the availability of dripping affected it to a lesser extent due to the constantly high humidity of the air. Diversity of species composition and taxonomic spectrum of cyanophytes was reduced from the entrance to the end of the cave, covarying positively with darkness stress.

A Mathematical Model for Advective Release from Perforated Waste Package Container Under Dripping Water

ABSTRACTA defense-in-depth engineered barrier system (EBS) is employed in the current design concept for the potential high-level nuclear waste repository at Yucca Mountain, Nevada, USA. Simplifying the geometry of the cylindrical waste container into the equivalent spherical configuration, and incorporating detailed analysis of the mechanics of water flow around the waste container surface, a mathematical model is developed for advective release from a “failed” (or perforated) waste container under dripping water. It is shown that the advective release rates are controlled by diffusion through the perforations in the waste container, and affected insignificantly by the dripping flow rate for the flow rate range considered. The release rates depend strongly on the number of perforations (or pit penetrations) in the waste container. The insensitivity of the release rate to the dripping flow rate is explained by the fact that radionuclide is released from the container surface to the boundary layer of the water film which contacts the container surface and is relatively stagnant. Also, since a laminar flow around the waste container surface is assumed in the model development, radionuclides transport across the water layers in the film by diffusion only. Additionally, the insignificant effect of the flow rate is contributed by the “short” penetration depth of radionuclide into the water film assumed in the model development. The analyses show that the number of perforations, the size of perforation, the container wall thickness, and the geometry (i.e., radius) of the waste container are important parameters that control the advective release rate. It is emphasized that the “failed” (or perforated) waste package container can still perform as a potentially important barrier to radionuclide release.

Strange attractors in a relaxation oscillator model for the dripping water faucet

Numerical evidence for the existence of strange chaotic attractors is found in a variable-mass relaxation oscillator model for the dripping faucet. We exhibit bifurcation maps which illustrate the richness of the model dynamics; we also have found simple periodic attractors up to period-12. More complex attractors exist which, after computing their fractal dimension and maximal Lyapunov exponent, can be regarded as both strange and chaotic. We have found evidence of boundary crisis and intermittence, as recent experimental results have shown to occur in the actual dripping system.

The route to chaos in a dripping water faucet

The dripping water faucet is a simple system which is shown in this article to be rich in examples of chaotic behavior. Data were taken for a wide range of drip rates for two different faucet nozzles and plotted as discrete time maps. Different routes to chaos, bifurcation and intermittency, are demonstrated for the different nozzles. Examples of period-1, -2, -3, and -4 attractors, as well as strange attractors, are presented and correlated to the formation of drops leaving the faucet.

Effect of water and nutrient supply on root distribution in anEucalyptus globulus plantation

Water and nutrients were supplied to anEucalyptus globulus plantation in a controlled experiment in west central Portugal. The trees were planted in a sandy soil at a spacing of 3 × 3 m. The experiment consisted of four treatments: irrigation, irrigation plus fertilization, fertilization without irrigation, and a rain fed and unfertilized control. The quantification of root biomass was carried out 13 mo after planting. When the plantation was 31 mo old, a trench was dug in the soil to uncover the distribution of the roots of individual trees. In the irrigated treatments root biomass was higher than in the control and in the fertilized plots. Differences in fine and coarse root distribution along the soil profile were also observed. In both irrigated treatments roots were concentrated along tree rows, where the irrigation tubes were dripping water or water plus nutrients.

Effect of water and nutrient supply on root distribution in an eucalyptus globulus plantation

Water and nutrients were supplied to an Eucalyptus globulus plantation in a controlled experiment in west central Portugal. The trees were planted in a sandy soil at a spacing of 3 × 3 m. The experiment consisted of four treatments: irrigation, irrigation plus fertilization, fertilization without irrigation, and a rain fed and unfertilized control. The quantification of root biomass was carried out 13 mo after planting.When the plantation was 31 mo old, a trench was dug in the soil to uncover the distribution of the roots of individual trees. In the irrigated treatments root biomass was higher than in the control and in the fertilized plots. Differences in fine and coarse root distribution along the soil profile were also observed. In both irrigated treatments roots were concentrated along tree rows, where the irrigation tubes were dripping water or water plus nutrients.

Observations on the Behavior of Color-Banded California Thrashers

The following observations on California Thrashers (Toxostoma redivivum) were made from November 8, 1935, to June 2, 1936, and from September 16, 1936, to June 1, 1937, at 241 South Holliston Avenue, Pasadena, California. My banding station was located on the open balcony of our rear second-story apartment. From this balcony and the windows of the apartment, I was able to identify with field glasses color-banded birds over an area of approximately 32,000 square feet, or about three-quarters of an acre, comprising seven back yards of neighboring residences. These casually gardened yards were situated in a pleasant old residential district. Bounded on the east and west by houses, they contained the usual human paraphernalia of cement driveways, garages and sheds. In addition was a varied and favorable bird environment: a dense cypress hedge 15 to 20 feet high and 5 feet thick, which supported many nests, a 50-foot cypress tree, three large untrimmed Washington palms, several large oaks, seven walnut trees, and numerous citrus and deciduous fruit trees. An abandoned dirt tennis court and several fence corners grew abundantly to weeds; morning-glory and honeysuckle vines flourished on two garages and on an old barn. Flower plots, low hedges and dense shrubs completed the picture. Each of the yards had an available water supply, either dripping water faucets, bird baths, or small fish ponds. The winter of 1935-1936 was mild, even for southern California, with moderate rains and few frosts. The winter of 1936-1937 was one of record cold. From Christmas to March, night frosts were almost continuous. Plant damage was heavy. In spite of the fact that children and adults, cats and dogs, and automobiles, frequently occupied the area, a large and healthy bird population maintained itself. Common resident species, beside the thrashers, were Western Mockingbirds, Song Sparrows, Brown and Spotted towhees, and California Jays. A flock of California Quail used the yards as part of their feeding ground and at least two pairs nested in it. House Finches and Gambel Sparrows were periodically numerous; Brewer Blackbirds became numerous the second spring. A Sharp-shinned Hawk was seen in the area only once, when it attacked a trapped sparrow on the balcony. Human residents were indifferent or mildly friendly to the birds. Pet cats were the chief enemies of birds.