Soda Straws Research Articles

Growth of chemical gardens in gaseous acidic atmospheres.

The generation of chemobrionic architectures through slow injection of aqueous silicate solution in gaseous TiCl4 is demonstrated. The tubes were characterized by XRD, SEM and wet chemistry control experiments, and their mechanism of formation was unraveled. These structures serve as laboratory models for calthemites or soda straws.

Secondary Minerals from Minothem Environments in Fragnè Mine (Turin, Italy): Preliminary Results

The Fragnè mine, located in the Lanzo valley in the municipality of Chialamberto (Turin, Piedmont Region), represented the most important regional site for Fe–Cu sulfide exploitation over a period of more than eighty years (1884–1965). The entire mining area is part of a structural complex in the Lower Piedmont Unit of the Western Alps, characterized by the presence of amphibolite, metabasite (“prasinite”), and metagabbroic rocks. In particular, the pyrite ore deposit occurs as massive mineralizations within interlayered metabasites and amphibolites. In this work, we describe secondary minerals and morphologies of minothems from the Fragnè mine that are found only in abandoned underground works, such as soda straws, normal and jelly stalactites and stalagmites, jellystones, columns, crusts, blisters, war-clubs, and hair, characterized by different mineralogical associations. All minothems were characterized by minerals formed during acid mine drainage (AMD) processes. Blisters are composed only of schwertmannite, war-clubs by schwertmannite, and goethite with low crystallinity and hair by epsomite and hexahydrite minerals. Jelly stalactites and stalagmites are characterized by schwertmannite often in association with bacteria, while solid stalactites and stalagmites are characterized by jarosite and goethite. The results indicate that the mineralogical transformation from schwertmannite to goethite observed in some minothems is probably due to aging processes of schwertmannite or local pH variations due to bacterial activity. On the basis of these results, we hypothesize that all the jelly samples, in association with strong bacterial activity, are slowly transformed into more solid goethite, and are thus precursors of goethite stalactites.

Nest preference and ecology of cavity-nesting bees (Hymenoptera: Apoidea) in Punjab, Pakistan

• Artificial nest boxes, an effective tool for nesting and conservation of bees. • Colonization of bees helpful in studying ecology and nesting biology. • The efficacy of nest boxes depends on nesting materials and dimensions of cavities. • Bamboo and drilled wooden log is the most preferred nesting material. • Six bee species along with one parasitic bee did nesting in our nesting materials. Among bees, 85 % are solitary species, most of them are ground-nester and some are cavity-nesting and construct their nests in pre-existing cavities. This work was conducted to evaluate the substrate preference and nest architecture (acceptance, occupation percentage, seasonality and parasitism) of cavity-nesting bees in different substrates. Trap nests offered comprised five different materials (drilled cavities in wood, bamboo, cardboard tubes, plastic soda straws, and mud blocks). These were installed in four districts for two years. The nesting cavities of five different diameters (6, 8, 10, 12 and 14 mm) were provided in each nesting material with an average length of 180 ± 9.92 mm. In all the materials, 5400 nesting cavities were offered, out of which 628 were colonized by bees from two families (Megachilidae and Apidae) and six species ( Megachile cephalotes, M. lanata, M. bicolor, Xylocopa basalis, X. fenestrata and Ceratina smaragdula ), including one parasitic bee ( Euaspis carbonaria ). The bee species differed significantly in occupying five nesting materials. The most preferred diameters were 8 mm and 10 mm, with 52.20% and 29.45% of colonization, respectively. Nesting was done throughout the year except in winter. This study will serve as a baseline for future studies and conservation programs of cavity-nesting bees in Pakistan.

Calcium Carbonate Precipitating Cultivable Bacteria from Different Speleothems of Karst Caves

The aim of the study was to reveal and compare the microbiota of different carbonate speleothems from two different epigenic karst regions (Baradla and Csodabogyós caves) in Hungary. Stalagmites, stalactites, soda straws, moonmilks, cave wall surfaces and dripping waters were sampled and plated on subsurface-environment imitating culture media containing low amount of nutrients, minerals and extract of cave sediments. Diverse oligo-heterotrophic bacterial community composition (192 different species in the phyla Actinobacteria, Proteobacteria, Firmicutes and Bacteroidetes) – with hitherto unknown cave bacteria – varied in the samples. The CaCO3 precipitating capacity of 126 bacterial strains from different taxonomical positions was tested on solid B4 medium. 75% of the strains precipitated crystals with various morphology in the colonies and metabolic tests showed that higher alkalizing activity led to higher rate of precipitation in the mucoid colonies. Scanning electron microscopy, high-resolution transmission electron microscopy and X-ray diffraction analysis indicated that the precipitates were dominated by calcite, and nanosize vaterite was identified for Paeniglutamicibacter kerguelensis (strain BaSD-225). Our study suggests that CaCO3 precipitated by proteolytic bacteria are widespread in the biofilms in karst caves and these bacteria can actively contribute to CaCO3 formation through alkalizing their microenvironment.

Genesis and evolution of the square soda straws of Dry Cave, West Virginia, USA

Genesis and evolution of the square soda straws of Dry Cave, West Virginia, USA

Seismic study of soda straws exposed to nearby blasting vibrations

This research study has been developed to preserve a remarkable soda straw population from vibrations emitted by nearby rock blasting. The Choranche stalactite cave (Vercors, France) contains thousands of exceptionally long soda straws reaching a few meters in length for ~ 0.5 cm in diameter. These slender speleothems are very vulnerable to vibrations not only because of their structural fragility but also because of their dynamic amplification. We found that soda straws’ first natural frequencies lie within the frequency range emitted by nearby rock blasting works (ten to hundreds of Hz). We used in situ blast records, laboratory characterization, and a dynamic 2D finite element code to simulate the load experienced by the soda straw population. We show that induced loads may be increased by a factor 5 due to resonance. Consequently, short soda straws (0.1–1 m) were found more vulnerable to nearby blasting vibrations than longer speleothems (> 1 m), despite greater own weight and inertial forces for the latter. Simulations made on several blast tests yielded an admissible 2.4 mm/s peak particle velocity along the cave. Subsequent blasting works were carried out in compliance with this threshold with no harm done to the soda straw population. We also computed the dynamic response of soda straws exposed to a regional earthquake. In this case, longer speleothems (> 1 m) are primarily affected by resonance because of ground motion lower frequency content. We show that the omission of dynamic resonance or its simplification as made in previous studies may significantly underestimate the induced load in speleothems.

Morphogenesis and microstructure of concrete-derived calthemites

Distributions of calcareous calthemite deposits have been widely documented, but depositional processes and the architecture of their internal fabrics are not well understood. These concrete degradation products from a case study area in western Canada have external morphologies comparable to calcite speleothems formed in natural limestone caves, but the internal microstructural architecture and mineralogy are markedly different. The mineralogy consists of mostly calcite with secondary halite and minor percentages of trona and portlandite. A novel morphogenetic model explains depositional processes resulting in calcareous crusts that follow fractures of an overlying concrete surface, and how sufficient structural integrity provided by the internal architecture supports attachment areas of tubular soda straws. Interiors of these multi-cm crusts consist of curvilinear calcite laminae arrayed as sub-parallel walls, compartmentalizing water–gas interfaces along variously interconnected conduits and basin-form chambers. Overall porosities of 40–60% or more are prevalent, in contrast to < 1% associated with externally similar drapery-form crusts deposited within natural limestone caves. Several calcite fabrics new to calthemite deposits are described, including dendritic shrubs that coalesce into concentric growth rings along central canals of soda straws.

Earthquake-related speleothem damages: observations from the 2008 Mw 7.9 Wenchuan, China

A speleoseismological study has been conducted at over a dozen cave sites along the Longmen Shan fault zone of the eastern Qinghai-Tibet Plateau. The aim was to assess the damage inflicted on speleothems by the Mw 7.9 Wenchuan earthquake. Results show that the earthquake led to either partial or complete collapse of the caves. ‘Soda straws’ are shown to be particularly vulnerable to earthquake damage, but statistical analyses indicate that the spindle and slender shapes are also very likely to break. Cave depth is also shown to play an important role in the fracture development during the earthquake. The measured orientations of fallen stalactites are preferentially aligned to the coseismic surface offset peaks and therefore to the direction of earthquake wave propagation. Several such damaged speleothems resulting from sudden co-seismic movements were observed. The direction of ceiling (hanging wall) movement caused by the Wenchuan earthquake is NW-NNW, consistent with block motion on the footwall of the Yingxiu-Beichuan fault. We inferred that the faults in the caves were not co-seismic structures of the Wenchuan earthquake; but instead they are likely normal faults as the result of gravity creeping induced by the earthquake.

Geological Heritage Values of the Yongcheon Cave (Lava Tube Cave), Jeju Island, Korea

Yongcheon Cave is a typical lava tube cave, which formed by multiple flows of lava during the Late Quaternary. However, it is also a lime-decorated cave with numerous splendid carbonate speleothems along two parts of the passage. This paper deals with these special unique features of the cave together with their formation processes and the geoheritage significance based on detailed investigation of overlying carbonate sand dunes and speleothems. The cave is about 3360 m long, composed of 2590-m-long main passage and about 370-m-long branch passages. Because the cave contains unexplored passages at the downstream end, it is estimated that the total length can be at least about 400 m longer. The cave contains various microtopographic characteristics such as multiple and various forms of lava coatings on the surface as well as dented features by thermal erosion. They include pahoehoe and aa lavas, rockfalls, lava falls, lava benches, gutters with overflowed lava levees, tube-in-tubes, and lava benches on the floor. Lava flowlines are prominent on the wall, and also, anastomosing branches, lava bridges, and multiple leveled floors are other distinctive morphological features. Carbonate sand dunes were formed by transportation of beach sands nearby and partially overlie two parts of the cave passage. Carbonate sediments are medium sand-sized and are mostly composed of mollusk and coralline red algae fragments up to 60~70% with a minor contribution of benthic foraminifers, echinoderms, bryozoans, and volcanic rock fragments, which may well represent typical temperate carbonate constituents elsewhere. Beach sediments, the source of carbonate dune sands, also show the similar texture and composition. This suggests that the dune sands were transported onto the area by wind along the valleys. Previous age dating results of four carbonate sand dunes including several paleosol layers imply the formation ages of the dunes at each site since the deposition of carbonate sands in shallow seas between 4700 and 6000 years BP due to full deglaciation after Last Glacial Maximum. Carbonate speleothems began to grow in the cave after the deposition of dunes. Detailed mapping of the cave and dune fields strongly suggest that the dune distributions are directly related to the formation of carbonate speleothems. A variety of carbonate speleothems are found in Yongcheon Cave such as soda straws, stalactites, stalagmites, columns, rimstones, flowstones, cave corals, draperies (curtains and bacon sheets), cave pearls, shelfstones, and moonmilks. However, many carbonate speleothems show erratic morphologies that cannot be seen in any limestone caves elsewhere. It is because the formation of erratic speleothems is directly influenced by distribution of plant roots which helped to transport rainwater into the cave and to precipitate calcite mineral. Their unique abundance of carbonate speleothems providing splendid scenic values as well as Jeju’s special geological conditions for their formation is considered to be the outstanding universal value for the World Heritage site.

Stick-weaving: Innovative behavior in tamarins (Saguinus oedipus).

Some captive cotton-top tamarins spontaneously weave sticks in the mesh of their enclosures so that the stick is lodged between two mesh openings. Sticks are broken from natural branches placed in the enclosures and often modified by biting them in the center before weaving through the mesh. To investigate this further, we systematically surveyed all animals in our colony and found that all successful stick-weaving tamarins were descendants from only 2 of the 16 breeding groups contributing to the colony membership at the time of surveying or were the mates of these descendants, suggesting stick-weaving is a socially learned behavior. Successful stick-weavers were presented with pipe cleaners, soda straws, and wooden dowels to see if they would generalize stick-weaving to novel objects. Seven of 10 animals successfully wove with straws or pipe cleaners, showing that they could generalize the behavior to objects that were physically different but had the same affordances as the sticks. Data from a father-daughter pair suggest a form of coaching. Innovative behavior is needed for the emergence of culture with subsequent social transmission. Although innovative behavior in primates is mainly associated with foraging and is more likely to occur among males, stick-weaving has no obvious reward and appeared equally in both sexes. Stick-weaving behavior and its probable social transmission across generations suggest the possibility of cultural traditions emerging in this species. (PsycINFO Database Record

The Petrographic Investigation of Soda Straws in Baeg-nyong Cave, Pyeongchang-gun, Gangwon-do, South Korea

The Petrographic Investigation of Soda Straws in Baeg-nyong Cave, Pyeongchang-gun, Gangwon-do, South Korea

Multi‐method (14C, 36Cl, 234U/230Th) age bracketing of the Tschirgant rock avalanche (Eastern Alps): implications for absolute dating of catastrophic mass‐wasting

AbstractCorrect and precise age determination of prehistorical catastrophic rock‐slope failures prerequisites any hypotheses relating this type of mass wasting to past climatic regimes or palaeo‐seismic records. Despite good exposure, easy accessibility and a long tradition of absolute dating, the age of the 230 million m3 carbonate‐lithic Tschirgant rock avalanche event of the Eastern Alps (Austria) still is relatively poorly constrained. We herein review the age of mass‐wasting based on a total of 17 absolute ages produced with three different methods (14C, 36Cl, 234U/230Th). Chlorine‐36 (36Cl) cosmogenic surface exposure dating of five boulders of the rock avalanche deposit indicates a mean event age of 3.06 ± 0.62 ka. Uranium‐234/thorium‐230 (234U/230Th) dating of soda‐straw stalactites formed in microcaves beneath boulders indicate mean precipitation ages of three individual soda straws at 3.20 ± 0.26 ka, 3.04 ± 0.10 ka and 2.81 ± 0.15 ka; notwithstanding potential internal errors, these ages provide an ‘older‐than’ (ante quam) proxy for mass‐wasting.Based on radiocarbon ages (nine sites) only, it was previously suggested that the present rock avalanche deposit represents two successive failures (3.75 ± 0.19 ka bp, 3.15 ± 0.19 ka bp). There is, however, no evidence for two events neither in surface outcrops nor in LiDAR derived imagery and drill logs. The temporal distribution of all absolute ages (14C, 36Cl, 234U/230Th) also does not necessarily indicate two successive events but suggest that a single catastrophic mass‐wasting took place between 3.4 and 2.4 ka bp. Taking into account the maximum age boundary given by reinterpreted radiocarbon datings and the minimum U/Th‐ages of calcite precipitations within the rock avalanche deposits, a most probable event age of 3.01 ± 0.10 ka bp can be proposed. Our results underscore the difficulty to accurately date catastrophic rock slope failures, but also the potential to increase the accuracy of age determination by combining methods. Copyright © 2016 John Wiley &amp; Sons, Ltd.

French Terminology of Speleological Forms

The aim of terminology of speleological forms is to describe these forms, and a cave is an assembly of forms. In France, terms of common language were first used, such as entree (« entrance »), draperie (« drapery », « curtain »), etc. and a few terms of scientific origin such as stalagmite. Then speleologists realized that it was possible to describe forms by their geometry. Thus such terms as cone d’eboulis (« talus cone ») or « tube » were used. When the geometry is detailed, the description is more precise: the information is better when we know that there is a « ceiling channel » above the tube or that a stalagmite is presented as a « hollow stalagmite ». Often a « group » of identical forms can be identified in a limited zone, whereas there are no such forms in other parts of the cave. This is often the case with potholes or soda straws for instance. This type of observation improves the quality of description. There is also what can be presented as « associated forms »: Certain speleological forms are associated with one another: a sinkhole corresponds to a resurgence; a stalactite corresponds to a stalagmite. A group and the zone of the cave where it can be observed are also associated forms. Other speleological forms are associated with a geological form: a contact sinkhole between two rocks of different solubility, dip tube, stalactites aligned along a crack. Other forms are associated with a geographical form: a flowing cave opening at the level of a surface stream, deposit of rounded pebbles in a surface stream sinkhole. There are also genetic terms; the most used being « phreatic » and « vadose ». These terms are useful for the interpretation of forms, but they are quite dangerous for the description of forms: if a passage is presented as «vadose », one does not know what are the forms justifying the word for the author. And if a tube is almost always presented as «phreatic », most of them have never been permanently filled with water, and some of them have never been filled with water. Genetic terms are deceptive. They must be avoided when forms are described.

지구물리 탐사에 의해 발견된 제주도 용암동굴의 특징과 의미

제주도에서 기존에 알려진 동굴 이외에 새로운 지하동굴의 존재를 확인하기 위해 제주시 구좌읍 일대에서 지구물리탐사(전기비저항탐사, GPR탐사, ZHF탐사)를 실시하였다. 탐사결과 여러 지점에서 동굴로 추정되는 이상대가 발견되었고, 이상대의 위치와 규모가 일치하는 27개 지점을 선별하여 시추조사를 실시하였다. 그러나 예상과 달리 이상대의 대부분은 용암의 상하부에 형성된 클링커층이거나 용암 사이에 협재된 고토양층이었으며, 5곳에서만 동굴이 발견되었다. 클링커층과 고토양층은 용암과 다른 암석의 물리적 특징으로 인해 이상체로 반응한 것으로 해석된다. 한편 동굴이 확인된 5개 지점 중 2공은 기존에 알려진 용천동굴을 관통하였고, 3공에서 새로운 동굴이 확인되었다. 용천동굴을 관통한 시추공은 시추당시 동굴의 존재가 확인되지 않았던 구간이었으나 용천동굴이 관통됨에 따라 기존 측량도의 오류를 수정하였다. 한편 시추조사로 새롭게 발견된 석회장식 용암동굴은 길이가 약 180 m이며, 상류방향으로 당처물동굴(약 110 m)과 연결되어 있다. 또한 동굴내부에는 용암곡석, 용암제방, 밧줄구조 등이 발달해 있으며, 탄산염 동굴생성물로는 종유관, 종유석, 석순, 석주, 동굴산호 등이 잘 보존되어 있다. 특히 동굴에서 발견되는 탄산염 동굴생성물은 식물 뿌리를 따라 유입된 지표수에 의해 성장하여 독특한 형태를 띠게 된 것으로 추정된다. Geophysical exploration using electric resistivity, ground penetrating radar (GPR), and impedance high-frequency (ZHF) surveys was conducted in Gujwa-eup, Jeju City, Jeju Island, an island in the Korea Strait, to confirm the existence of new caves near known caves. The exploration revealed a number of anomaly zones, presumed to be caves; 27 sites at suitable locations and depth ranges were selected for drilling and further surveys. However, contrary to predictions, most of the anomaly zones were clinker layers or paleosols intercalated with lavas. Only five boreholes intersected caves. The clinker layers and paleosols were possibly detected as anomalies owing to their different physical properties from the other rocks. Two of the five cave-finding boreholes penetrated Yongcheon Cave; a new cave was found at the other. The two boreholes that penetrated Yongcheon Cave were drilled in areas where the cave has not been previously reported, and thus helped correct an error in the cave distribution map. The cave newly discovered in this boring exploration is 180 m long, and it is connected to the upstream part of Dangcheomul Cave (110 m). The cave contains well-developed lava helictites, lava levees, and ropy structures; carbonate speleothems such as soda straws, stalagmites, columns, and curtain shawls are also well preserved. Notably, the unique shape of the carbonate speleothems is attributed to their growth in relation to the cavern water that flowed into the cave along plant roots.

Utilization of Waste Materials for Management of Alfalfa Pollinating Megachilid Bees

AbstractHollow waste stems of sarkandas (Arundo sp. and Saccharum sp.) and castor (Ricinus communis L.) cut into small lengths were tried as nesting tunnels for culturing/keeping the wild bee pollinators. Of the four megachild bees, three of them easily accepted these tunnels for provisioning and nesting activities. The provisioning bees were the specialist pollinators of important crops like alfalfa (Medicago sativa L.), pigeon pea (Cajanus cajan Millsp.) and cucurbits. During the study period, three species of megachilid bee were found to nest, reproduce and build their populations in these tunnels. This paper discusses the possibility of harnessing Megachile harayanesis, Chalicodoma rubripes and M. femorata for which various artificial devices were tried. The castor stems and soda straws fixed in the drilled wooden boards/blocks were ultimately found as the most convenient means acceptable to the bees for nest construction, especially in 6 mm internal diameter (I.M). Although tunnels of lower significantly the number of cells constructed per tunnel. Decrease in cell number seemed independent of the tunnel length and the cell length also remained unaffected. If length of the tunnel was taken as the parameter against acceptability by M. haryanaensis, 10 cm tunnels were found to be the most suitable. The nesting behavior of C. rubripes and C. cephalotes as affected by the tunnel characteristics has also been discussed. A comparision for the tripping efficiency has also been drawn among the indigenous megachilid bees and Nomia malanderi and Megachile rotundata. Among them M. haryanaensis has been found to be the most efficient.

Saru-ana Cave (limestone cave) in the Kanetsuri area along Kurobe Gorge, eastern Toyama Prefecture of central Japan.

This paper describes Saru-ana Cave, located along Kurobe Gorge in the Kanetsuri area, eastern Toyama Prefecture, central Japan. Saru-ana Cave (total passage length, ca. 120 m; relative height, ca. 40 m) opens onto a steeply inclined cliff face, 75 m above the bed of the Kurobe River. The cave consists of horizontal to inclined rooms and vertical shafts. Speleothems in the cave, although not abundant, include cave corals, flowstones, soda straws, stalactites, and a stalagmite. Fossil specimens of six Japanese Macaque individuals (Macaca fuscata) were collected from the cave for paleontological investigation.

Spatially dense drip hydrological monitoring and infiltration behaviour at the Wellington Caves, South East Australia

Despite the fact that karst regions are recognised as significant groundwater resources, the nature of groundwater flow paths in the unsaturated zone of such fractured rock is at present poorly understood. Many traditional methods for constraining groundwater flow regimes in karst aquifers are focussed on the faster drainage components and are unable to inform on the smaller fracture or matrix-flow components of the system. Caves however, offer a natural inception point to observe both the long term storage and the preferential movement of water through the unsaturated zone of such fractured carbonate rock by monitoring of drip rates of stalactites, soda straws and seepage from fractures/micro fissures that emerge in the cave ceiling. Here we present the largest spatial survey of automated cave drip rate monitoring published to date with the aim of better understanding both karst drip water hydrogeology and the relationship between drip hydrology and surface climate. By the application of cross correlation functions and multi-dimensional scaling, clustered by k-means technique, we demonstrate the nature of the relationships between drip behaviour and initial surface infiltration and similarity amongst the drip rate time series themselves that may be interpreted in terms of flow regimes and cave chamber morphology and lithology.

Factors Influencing Observed Variations in the Structure of Bacterial Communities On Calcite Formations in Kartchner Caverns, AZ, USA

Kartchner Caverns is an oligotrophic subterranean environment that hosts a wide diversity of actively growing calcite speleothems (secondary mineral deposits). In a previous study, we demonstrated that bacterial communities extracted from these surfaces are quite complex and vary between formations. In the current study, we evaluated the influence of several environmental variables on the superficial bacterial community structure of 10 active formations located in close proximity to one another in a small room of Kartchner Caverns State Park, Arizona, USA. Physical (color, dimensions) and chemical (elemental profile and organic carbon concentration) properties, as well as the DGGE-based bacterial community structure of the formations were analyzed. While elemental concentration was found to vary among the formations, the differences in the community structure could not be correlated with concentrations of either organic carbon or any of the elements evaluated. In contrast, the locations of formations within a distinct region of the cave as well as the relative location of specific formations within a single room were found to have a significant influence on the bacterial community structure of the formations evaluated. Interestingly, Canonical Correspondence Analysis suggests an association between the observed drip pathways (drip lines) feeding the formations (as determined by the patterns of soda straws and small stalactites that reveal water flow patterns) and the bacterial community structure of the respective formations. The results presented here indicate that a broad range of formations fed by a diversity of drip sources must be sampled to fully characterize the community composition of bacteria present on the surfaces of calcite formations in carbonate caves.

Spatial distribution of soda straws growth rates of the Coufin Cave (Vercors, France)

The Choranche Cave system (Vercors, France) is an excellent locality for measuring the growth rates of large numbers soda straws. This is especially the case for the Coufin Cave, as enlargement of the cave entrance in 1875 led to a change in stalactite color from brown to white, thus providing a reliable chronomarker. The date of this brown-to-white calcite transition has been confirmed by lamina counting. We measured and georeferenced the growth-lengths of 306 soda straws in a 1m2 area of the roof of the Coufin Cave entrance chamber. Because of the very slow and sometimes inexistent water feeding of those stalactites, hydrochemistry analysis were not achieved and drop rate effect on growth were neglected; this study is based on a geomorphological and geostatistical work. By measuring a large number of soda straws in a very small area for which most of the parameters affecting stalactite growth could be considered uniform, and because flow rates are very slow (frequencies are always superior to 1 drop per half hour), we could ascribe differences in growth rates to variations in the global increase of water flow through the unsaturated matrix. Statistical and geostatistical analyses of the measurements showed that this set of similarly shaped stalactites actually consisted of three Gaussian populations with different mean growth rates: fast growth rate (FGR- mean of 0.92 mm.y-1), medium growth rate (MGR- mean of 0.47 mm.y-1) and low growth rate (LGR- 0.09 mm.y-1). Plotting the lengths and spatial distribution of the 20 longest FGR soda straws revealed that there is a rough pattern to the water flow through the cave roof. Even if no direction is statisticaly different from others, the observed directional pattern is consistent with local and regional tectonic observations. Plots of the spatial distribution of the soda straws show that FGR soda straws follow lines of regional geological stress, whereas MGR and LGR soda straws are more dispersed.

Collection Efficiencies of Various Airborne Spray Flux Samplers Used in Aerial Application Research

Abstract A low air speed, spray dispersion tunnel was constructed and used to evaluate the collection efficiency of passive spray flux collectors. The dispersion tunnel utilizes an air-assisted nozzle to generate a spray cloud with a DV0.5 of 18.5 (±0.4) μm at air speeds ranging from 0.4–4.0 m/s. A sampling protocol was developed to minimize spray flux and air speed variation effects while providing a check on theoretical collection efficiency calculations. A soda straw and monofilament line was placed on either side of a nylon screen cylinder collector, and all three were positioned in the center of the tunnel’s cross-sectional area. Twelve replicated trials were conducted at air speeds of 0.4, 1.3, 2, and 3.8 m/s. Droplet size was measured every replication using a Sympatec HELOS laser diffraction system. Using theoretical collection efficiencies for cylinders and the measured fractional droplet size, the actual flux was estimated from the volume of spray collected on the soda straw and monofilament samplers and used to determine the collection efficiency of the nylon screen cylinder. Collection efficiency increased with air speed for all collectors and results ranged from 5 to 40 % for the soda straws, 46 to 83 % for the monofilament line, and 9 to 98 % for the nylon screen cylinders. Collection efficiency data are crucial to the evaluation of field collected data from aerial application research studies with respect to mass accountability and comparisons to other studies and drift model results.