Although nest reuse is most commonly associated with costs such as nest instability and increased ectoparasite loads,contrary evidence supports the possibility that nest reuse might provide an adaptive function in the form of time and energy savings. The Cave Swallow (Petrochelidon fulva), which nests under bridges and culverts in east-central Texas, chooses predominately to reuse nests when old nests are available. I conducted a field experiment involving bridge pairs and single bridges, in which I applied a treatment of nest removal to one bridge of each pair and one half of each single bridge in order to test whether control bridges and nests exhibited increased productivity from the availability of old nests. I found that a higher percentage of young fledged from control bridges and more fledged per clutch from control bridges. Small sample sizes diminished the ability to detect differences within the single bridge experiment. Results from this research support the time-energy savings concept and may be reconciled with conflicting research through fundamental differences between studies in immunity to ectoparasites, infestation type, and nest microclimate.

Ever since it was identified as a speleogenetic process in the Guadalupe Mountains of New Mexico, USA, hypogene speleogenesis has become the focus of numerous research projects aimed at discerning between classical epigene caves and sulfuric acid or thermal caves. The first distinguishing characteristics that were recognized for hypogene caves were passage and cave morphology. The following step was the identification of rare minerals, specific for processes associated to hypogene speleogenesis. One other important step was the recognition of the importance of stable isotopes - mainly of S - in tracing the source of S and the chemical processes affecting it. Many of the caves now labeled as hypogene are fossil caves, in which presently the hypogene activity has long died off. Studies comparing stable isotopes from coexisting cave minerals and the waters that generate the cave are rarer. This extensive study encompasses a description of cave and passage morphologies, cave mineral assemblages, as well as hydrogeochemistry of thermomineral waters in a peculiar region of Romania. Băile Herculane (Cerna River Valley, SW Romania) is a spa town known since Roman times for its numerous thermal springs that were considered to have healing powers. These springs, along with wells drilled in the past century, are still being used for curative purposes in several treatment centers in Băile Herculane. The present study is important not only for the scientific data it produced, but also for economic purposes, as mixing of the thermomineral waters with meteoric sources is a major concern, due to the dilution it causes. The data presented here is based on multiple investigation methods, each specific to the analyzed material: powder X-ray diffractions, scanning electron microscope, electron microprobe (for mineral samples), sedimentological investigations (for cave sediments), stable isotope mass spectrometry (for water and mineral samples), field measurements (for water samples). The results presented here help to clarify the source of dissolved S species in the thermomineral water, the source of the water itself, as well as establish a connection between caves along the Cerna Valley and the thermomineral aquifers.

There is a strong concern about how water resources will be affected by future climate change. Investigation of how a hydrologic system might respond to climate change, however, requires a detailed understanding of the controls on and factors that might affect that system. The research presented in this dissertation focuses on improving the understanding of the Barton Springs segment of the Edwards aquifer in central Texas. The first three chapters of this dissertation present research investigating spatial and temporal controls on groundwater geochemistry. The fourth chapter focuses on characterizing and understanding the controls on long-term hydrologic variability by reconstructing past climate from a speleothem (cave mineral deposit) collected from a central Texas cave. On spatial scales, Edwards aquifer groundwater geochemistry is influenced by water-rock interaction (calcite and dolomite recrystallization, gypsum dissolution, and calcite precipitation) and mixing between fresh groundwater and saline groundwater. On temporal scales, variation in groundwater geochemistry is dictated by the extent to which fresh groundwater mixes with recharging stream water. The degree of mixing is sensitive to changes in climate conditions (i.e., more mixing under wetter conditions) and type of flow path (i.e., conduit or diffuse) that dominantly supplies a given site. The geochemistry of stream water, which provides the majority of recharge to the aquifer, is degrading over time and indirectly controlled by anthropogenic sources under both wet and dry conditions. Climate reconstructed from a speleothem suggests that central Texas moisture conditions were relatively constant from the mid to late Holocene (0 to 7 ka), except for an extended dry interval from 0.5 to 1.5 ka. Speleothem δ18O values spike during this dry interval, suggesting that decreases in Pacific-derived moisture or decreased tropical storm activity might have been coincident with the prolonged dry interval. This research has improved understanding of the natural variability of and controls on physical and geochemical components of hydrologic system in central Texas. / text

Στην παρούσα εργασία πραγματοποιήθηκε πετρογραφική μελέτη των σπηλαιοθεμάτων του σπηλαίου του Περάματος Ιωαννίνων, με σκοπό την άντληση πληροφοριών από τα σπηλαιοθέματα για τις παλαιοκλιματολογικές συνθήκες. / In the present paper we study Ioannina's cave speleothems petrographicly , with the purpose of obtaining information from speleothems for paleoclimatic conditions.

No description available.

Architectural, Engineering, and Construction (AEC) industry has been using 4D construction models (graphical illustration of the construction of a 3D building design with time as the 4th dimension) for many years to improve an existing construction schedule by identifying inconsistencies and out of sequence activities; reducing missing activities; and improving the ability to communicate construction plan information. In practice, majority of the AEC industry has been using a personal computer based monitor to view and analyze these models. A study on investigating the potential benefits and challenges of using an immersive 3D virtual environment to view 4D models proved that by interactively generating construction schedule in the immersive virtual environment, the construction professionals were able to identify design, constructability, sequencing, and interdisciplinary interfacing issues which resulted in the construction professionals being able to develop a plan that resulted in a 28% savings to their original schedule. The major shortcoming of these immersive virtual reality systems was the Building Information Models (BIM) had to be converted to a specific format before they can be visualized in the immersive virtual environments. This study is an attempt to address the shortcomings of the previous version of the BIM CAVE which had the control over the camera views for achieving an almost seamless immersive virtual environment by developing a new BIM CAVE application which synchronizes timelining of 4D construction sequence in BIM CAVE. The new BIM CAVE setup is run by a custom built application that makes use of the .Net API (Application Programming Interface) of the commercially available BIM application, Autodesk Navisworks 2012. The objective of this research is to investigate the effectiveness, potential benefits and challenges of timelining the 4D construction sequence in BIM CAVE developed at Texas A&M University by using a qualitative research methodology called phenomenological study. The findings of this research specify that timelining the 4D construction sequence in BIM CAVE has many potential benefits like better spatial perception which increases confidence of construction professionals over the schedule, better sequencing of construction activities, better communication of schedule, evaluating constructability issues, and training the work force. Thus, this research concludes that timelining the construction in BIM CAVE is effective over visualizing 4D construction on a single screen with some limitations mentioned in this research.

The Tamana Cave system in Trinidad is relatively unaffected by the environment outside of the cave walls, like most cave ecosystems. Since a very limited amount of light can enter the cave, bat movement controls the temperature cycle rather than the solar radiation that controls it in the surrounding forest. Similarly, the ecosystem cannot be sustained by energy from photosynthesis and so the main source of energy comes from the guano produced by the insectivorous bat species, N. tumidirostris. The frugivorous bat species, P. hastatus, also roosts inside of the cave, but the wetness of the top level of its guano prevents the guano from being suitable for cockroach consumption and therefore ends the flow of energy through the system. STELLA software was used to create a model consisting of three stacked logistic growth equations that demonstrate the ecosystem of Tamana cave. The model focuses on the population of insectivorous bats, on the guano that this species produces, and on the cockroach species, E. distanti. The model provides insight into the population dynamics and environmental processes at play in the cave, and is useful in predicting the behavior of the ecosystem. After running the model under a number of different scenarios, the graphs were used to visually display the effects of altering inputs in the system. These altered inputs represent hypothetical changes that could occur in a natural system such as a lowered intrinsic rate of increase bat population, an increase in initial bat population, or a decrease in the amount of guano that each cockroach needs to survive.

Building Information Modeling (BIM) model contains information about structural, architectural, MEP (Mechanical Electrical and Plumbing) and other numerous components of a building. Among these components, MEP constitutes about 50% of the project cost, and its design is relatively more complex because of the limited headroom available to locate these components. The coordination of these systems involves locating and routing several subcomponents in a manner that satisfies different types of constraints. The earlier version of BIM Computer Aided Virtual Environment (CAVE) did not have provisions to show the overhead components of a BIM model. Conventionally, models had to be tilted to visualize the overhead components. The process of tilting the models to look up is considered counterintuitive. Some of the popular CAVEs developed by leading Universities have a screen on top to show the overhead components but they have a major shortcoming with them. The BIM models had to be converted to a specific format before they can be visualized in the CAVE environments. This study is an attempt to address the shortcomings of the previous version of the BIM CAVE by suggesting a prototype setup with a 55" LCD screen on top of the existing three vertically placed LCD screens. The addition of one more screen on top increases the vertical field of view, that is, the extent to which the user can see vertically in a BIM model. The new BIM CAVE setup is run by a custom built application that makes use of the .Net API (Application Programming Interface) of the commercially available BIM application, Autodesk Navisworks 2012, to control the camera views for achieving an almost seamless semi-immersive virtual environment. The main objective of this research is to validate the effectiveness of the new setup suggested by using a qualitative research methodology called phenomenological study. Semi-structured informal interviews were conducted with the subject matter experts (SMEs) who are experienced in the field of BIM to know about the differences in the user experience after adding a screen on top of the earlier BIM CAVE setup. The main idea behind this qualitative research technique is to develop an understanding of how the SMEs perceived the idea of looking up to see the overhead components of the BIM model. This thesis explains the steps followed to develop the modified BIM CAVE setup in detail and findings of the qualitative study to know about the effectiveness of the suggested new setup.

The abundance and size classes of ground weta, cave weta, carabid beetles and prowling spiders were monitored in the La Trobe Forest Ecosystem Restoration Project, Karekare, West Auckland, where rodent populations had been reduced. These were compared with those in control sites, where the rodent populations had not been manipulated. The arthropods were sampled using pitfall traps set in young podocarp-broadleaf, mature kanuka and mature taraire forested sites, and each treatment site was matched with two control sites. Data was collected monthly from all nine sites from December to May, 2005-06. In kanuka forest, data collected during December to May, 2004-05 has also been used.Rodent populations and possum populations were monitored during the course of the study. Tracking tunnel indices indicated that rat numbers were lower in the treatment sites than the control sites during 2005-06, and that rats were low in abundance at the treatment sites, apart from the occasional spike in numbers, in the three years prior to the start of this research. Mice tracking indices were relatively high at some specific sites, mainly in spring and autumn. Evidence indicated that possum abundance was low in both the treatment and the control sites.Ground weta were more abundant at the kanuka treatment site than the control sites in 2005-06, but were rarely found in the podocarp-broadleaf and taraire forest types. Carabid beetles were trapped in greater numbers in podocarp-broadleaf and kanuka forest treatment sites in 2005-06, than in their respective control sites, and an increase in carabid beetle abundance was recorded between the 2004-05 and 2005-06 sampling seasons at the kanuka treatment site. Prowling spiders were more abundant at the podocarp-broadleaf treatment than at the control sites. Cave weta abundance at the podocarp-broadleaf and kanuka treatment sites was similar to their respective control sites. The arthropod abundance data from the taraire forest sites was confounded by many differences between the treatment and the control sites, which may have masked any effects caused by the suppression of rodent numbers at the treatment site.Ground weta and cave weta in the larger size classes appeared to be selectively preyed upon by predators, however, it was unclear whether rodents were entirely responsible because stoats and cats are also known to target larger arthropod prey, and their presence was not monitored.Ground weta in kanuka forest, carabid beetles in kanuka and podocarp-broadleaf forest and prowling spiders in podocarp-broadleaf forest are identified as potential indicators for monitoring the effects of rodent control in the Waitakere Ranges.This study was limited by a lack of knowledge of life histories and basic ecology of the arthropods. Further research at these sites is required to establish the long term population patterns of the arthropods.

Abstract Aragonite is a minor secondary mineral in many limestone caves throughout the world. It has been claimed that it is the second-most common cave mineral after calcite (Hill & Forti 1997). Aragonite occurs as a secondary mineral in the vadose zone of some caves in New South Wales. Aragonite is unstable in fresh water and usually reverts to calcite, but it is actively depositing in some NSW caves. A review of current literature on the cave aragonite problem showed that chemical inhibitors to calcite deposition assist in the precipitation of calcium carbonate as aragonite instead of calcite. Chemical inhibitors work by physically blocking the positions on the calcite crystal lattice which would have otherwise allowed calcite to develop into a larger crystal. Often an inhibitor for calcite has no effect on the aragonite crystal lattice, thus aragonite may deposit where calcite deposition is inhibited. Another association with aragonite in some NSW caves appears to be high evaporation rates allowing calcite, aragonite and vaterite to deposit. Vaterite is another unstable polymorph of calcium carbonate, which reverts to aragonite and calcite over time. Vaterite, aragonite and calcite were found together in cave sediments in areas with low humidity in Wollondilly Cave, Wombeyan. Several factors were found to be associated with the deposition of aragonite instead of calcite speleothems in NSW caves. They included the presence of ferroan dolomite, calcite-inhibitors (in particular ions of magnesium, manganese, phosphate, sulfate and heavy metals), and both air movement and humidity. Aragonite deposits in several NSW caves were examined to determine whether the material is or is not aragonite. Substrates to the aragonite were examined, as was the nature of the bedrock. The work concentrated on Contact Cave and Wiburds Lake Cave at Jenolan, Sigma Cave, Wollondilly Cave and Cow Pit at Wombeyan and Piano Cave and Deep Hole (Cave) at Walli. Comparisons are made with other caves. The study sites are all located in Palaeozoic rocks within the Lachlan Fold Belt tectonic region. Two of the sites, Jenolan and Wombeyan, are close to the western edge of the Sydney Basin. The third site, Walli, is close to a warm spring. The physical, climatic, chemical and mineralogical influences on calcium carbonate deposition in the caves were investigated. Where cave maps were unavailable, they were prepared on site as part of the study. %At Jenolan Caves, Contact Cave and Wiburds Lake Cave were examined in detail, %and other sites were compared with these. Contact Cave is located near the eastern boundary of the Late Silurian Jenolan Caves Limestone, in an area of steeply bedded and partially dolomitised limestone very close to its eastern boundary with the Jenolan volcanics. Aragonite in Contact Cave is precipitated on the ceiling as anthodites, helictites and coatings. The substrate for the aragonite is porous, altered, dolomitised limestone which is wedged apart by aragonite crystals. Aragonite deposition in Contact Cave is associated with a concentration of calcite-inhibiting ions, mainly minerals containing ions of magnesium, manganese and to a lesser extent, phosphates. Aragonite, dolomite and rhodochrosite are being actively deposited where these minerals are present. Calcite is being deposited where minerals containing magnesium ions are not present. The inhibitors appear to be mobilised by fresh water entering the cave as seepage along the steep bedding and jointing. During winter, cold dry air pooling in the lower part of the cave may concentrate minerals by evaporation and is most likely associated with the ``popcorn line'' seen in the cave. Wiburds Lake Cave is located near the western boundary of the Jenolan Caves Limestone, very close to its faulted western boundary with Ordovician cherts. Aragonite at Wiburds Lake Cave is associated with weathered pyritic dolomitised limestone, an altered, dolomitised mafic dyke in a fault shear zone, and also with bat guano minerals. Aragonite speleothems include a spathite, cavity fills, vughs, surface coatings and anthodites. Calcite occurs in small quantities at the aragonite sites. Calcite-inhibitors associated with aragonite include ions of magnesium, manganese and sulfate. Phosphate is significant in some areas. Low humidity is significant in two areas. Other sites briefly examined at Jenolan include Glass Cave, Mammoth Cave, Spider Cave and the show caves. Aragonite in Glass Cave may be associated with both weathering of dolomitised limestone (resulting in anthodites) and with bat guano (resulting in small cryptic forms). Aragonite in the show caves, and possibly in Mammoth and Spider Cave is associated with weathering of pyritic dolomitised limestone. Wombeyan Caves are developed in saccharoidal marble, metamorphosed Silurian Wombeyan Caves Limestone. Three sites were examined in detail at Wombeyan Caves: Sigma Cave, Wollondilly Cave and Cow Pit (a steep sided doline with a dark zone). Sigma Cave is close to the south east boundary of the Wombeyan marble, close to its unconformable boundary with effusive hypersthene porphyry and intrusive gabbro, and contains some unmarmorised limestone. Aragonite occurs mainly in a canyon at the southern extremity of the cave and in some other sites. In Sigma Cave, aragonite deposition is mainly associated with minerals containing calcite-inhibitors, as well as some air movement in the cave. Calcite-inhibitors at Sigma Cave include ions of magnesium, manganese, sulfate and phosphate (possibly bat origin), partly from bedrock veins and partly from breakdown of minerals in sediments sourced from mafic igneous rocks. Substrates to aragonite speleothems include corroded speleothem, bedrock, ochres, mud and clastics. There is air movement at times in the canyon, it has higher levels of CO2 than other parts of the cave and humidity is high. Air movement may assist in the rapid exchange of CO2 at speleothem surfaces. Wollondilly Cave is located in the eastern part of the Wombeyan marble. At Wollondilly Cave, anthodites and helictites were seen in an inaccessible area of the cave. Paramorphs of calcite after aragonite were found at Jacobs Ladder and the Pantheon. Aragonite at Star Chamber is associated with huntite and hydromagnesite. In The Loft, speleothem corrosion is characteristic of bat guano deposits. Aragonite, vaterite and calcite were detected in surface coatings in this area. Air movement between the two entrances of this cave has a drying effect which may serve to concentrate minerals by evaporation in some parts of the cave. The presence of vaterite and aragonite in fluffy coatings infers that vaterite may be inverting to aragonite. Calcite-inhibitors in the sediments include ions of phosphate, sulphate, magnesium and manganese. Cave sediment includes material sourced from detrital mafic rocks. Cow Pit is located near Wollondilly Cave, and cave W43 is located near the northern boundary of the Wombeyan marble. At Cow Pit, paramorphs of calcite after aragonite occur in the walls as spheroids with minor huntite. Aragonite is a minor mineral in white wall coatings and red phosphatic sediments with minor hydromagnesite and huntite. At cave W43, aragonite was detected in the base of a coralloid speleothem. Paramorphs of calcite after aragonite were observed in the same speleothem. Dolomite in the bedrock may be a source of magnesium-rich minerals at cave W43. Walli Caves are developed in the massive Belubula Limestone of the Ordovician Cliefden Caves Limestone Subgroup (Barrajin Group). At the caves, the limestone is steeply bedded and contains chert nodules with dolomite inclusions. Gypsum and barite occur in veins in the limestone. At Walli Caves, Piano Cave and Deep Hole (Deep Cave) were examined for aragonite. Gypsum occurs both as a surface coating and as fine selenite needles on chert nodules in areas with low humidity in the caves. Aragonite at Walli caves was associated with vein minerals and coatings containing calcite-inhibitors and, in some areas, low humidity. Calcite-inhibitors include sulfate (mostly as gypsum), magnesium, manganese and barium. Other caves which contain aragonite are mentioned. Although these were not major study sites, sufficient information is available on them to make a preliminary assessment as to why they may contain aragonite. These other caves include Flying Fortress Cave and the B4-5 Extension at Bungonia near Goulburn, and Wyanbene Cave south of Braidwood. Aragonite deposition at Bungonia has some similarities with that at Jenolan in that dolomitisation of the bedrock has occurred, and the bedding or jointing is steep allowing seepage of water into the cave, with possible oxidation of pyrite. Aragonite is also associated with a mafic dyke. Wyanbene cave features some bedrock dolomitisation, and also features low grade ore bodies which include several known calcite-inhibitors. Aragonite appears to be associated with both features. Finally, brief notes are made of aragonite-like speleothems at Colong Caves (between Jenolan and Wombeyan), a cave at Jaunter (west of Jenolan) and Wellington (240\,km NW of Sydney).