Physical Sciences and Mathematics Commons^™

Hydrogeophysical Assessment Of Groundwater And Saltwater–Freshwater Interface In A Quaternary– Neogene Coastal Aquifer, Kilwa Kisiwani Island, Southeast Tanzania, Simon R. Melchioly

Tanzania Journal of Science

This study aims to identify and explore new potential sites of groundwater resources using geophysical methods, and to demarcate the depth to the saltwater-freshwater interface. Kilwa Kisiwani Island is geologically covered mostly by Neogene and Quaternary alluvial sediments, sand and gravel. The geophysical techniques employed during the research include Vertical Electrical Sounding (VES), Electrical Resistivity Tomography (ERT), and Transient Electromagnetics (TEM). The Island has the potential for groundwater occurrences, but the layer with fresh water is shallow and thin. Out of the 18 VES sites, 2 (11%) points have shown non-potential, but the remaining 16 (89%) of the VES sites …

Aeroradio-Spectrometric Geothermal Analysis Of Abeokuta, Southwestern Nigeria, Fidelis O. Ogunsanwo

Tanzania Journal of Science

Weathered basement terrains of Precambrian origin are increasingly recognized as important targets for geothermal assessment and renewable energy exploration; yet systematic assessments integrating airborne radiometric data remain limited in south-western Nigeria. This study applies an aeroradio-spectrometric approach to evaluate and quantify the radiogenic heat production, geothermal gradient, and lithospheric heat flow associated with the diverse lithological assemblages of the Abeokuta area, southwestern Nigeria. The study area comprises of six lithological units, namely; biotite–garnet gneiss and schist, porphyroblastic gneiss, migmatite, pegmatite intrusions, and sedimentary successions of sand-clay-shale and sandstone–limestone. The concentrations of uranium (238U), thorium (232Th), and potassium (40K) were extracted …

Assessment Of The Radionuclide Concentration Levels Of Water And Sediments Along The Mara River, Gasper Kachenge, Abubakary Salama, Abdalah Kileo, Furaha Chuma

Tanzania Journal of Science

For many years, several factors have impacted the water quality of the Mara River, including population growth, agricultural expansion, livestock keeping, mining, and industrial activities. These factors have intensified water pollution and climate change effects around the river. While previous studies have mainly focused on assessing heavy metal pollution risks on the Mara River, this study evaluates the concentration levels of radionuclides in boreholes, water, and sediments along the river and its tributaries. Naturally occurring radioactive materials, including 226Ra, ²³²Th, and ⁴⁰K, were evaluated. A high-purity germanium radiation detector (HPGe) with a coaxial detector system coupled with Gamma Vision software …

Earthquake-Resistant Design And Base Isolation Techniques, Christian George, Jacob Sweeten, Gabriela Cotto, Savion Stewart

Discovery Day - Daytona Beach

Earthquake-resistant design has become a critical feature in construction near active fault lines, where seismic activity is most frequent and potentially destructive. In recent years, technological advancements have significantly improved methods for protecting buildings from earthquake damage. Among these innovations, base isolation systems have appeared as one of the most effective solutions. By decoupling a building from ground motion, base isolators reduce the transmission of seismic forces, helping to prevent structural damage and support building stability during earthquakes. In addition to improving safety, base isolation systems can also reduce long-term costs associated with earthquake-related repairs and maintenance. Base-isolated structures are …

System And Method For Detecting Subsurface Voids Using Controlled Heat Addition, Chase Nilsson

Discovery Day - Daytona Beach

This study evaluates controlled heat addition in a confined space to estimate enclosed volumes for irregularly shaped spaces. The intent is to detect hidden voids in cave environments. Conventional methods for identifying such voids are often costly, logistically difficult, and limited in accuracy. Preliminary experiments were conducted with a controlled heat source, a temporary thermal barrier to isolate the test chamber, and simple temperature sensors. Temperatures were recorded for the pre-test baseline, the heating interval, followed by a cooling period. The thermal response showed clear engineering trends that warrant further exploration and modeling. Preliminary results indicate that transient temperature changes …

Temperature And Hydrologic Context Influence Methane Variability In A Low-Salinity Marsh, Zoie Brauser

Dissertations and Theses

Coastal wetlands are biogeochemical hotspots that capture and transform carbon and nutrients. Wetland restoration is increasingly used as a climate mitigation strategy because of wetlands' capacity to sequester large amounts of carbon. However, low-salinity tidal marshes exhibit high variability in methane (CH₄) emissions, which could partially offset carbon sequestration under certain conditions. Understanding the drivers of CH₄ variability is crucial for restoration and conservation work. This project uses an observational research approach to assess the relationships between environmental factors and carbon dioxide (CO₂) and CH₄ soil gas fluxes in a restored low-salinity tidal marsh …

Understanding The Long-Term Patterns Of Change Of A Tidal Marsh In Mission Bay, San Diego, California, Carrie A. Shuster, Theresa Sinicrope Talley Ph.D., Drew Talley Ph.D., Zhi-Yong Yin Ph.D., Kellie Uyeda Ph.D.

Theses

Coastal marshes are among California’s most productive ecosystems and the most impacted, having been extensively modified by dredging, filling, and urban development. This thesis investigates over a century of change for a marsh in Northern Mission Bay, San Diego, California using ecological and spatial analyses.

Chapter 1 provides an overview of the environmental history and current land use of the Northern Mission Bay marsh, tracing changes from pre-contact Indigenous stewardship through colonial and modern urban development. It also introduces a restoration plant palette derived from historical and contemporary species occurrences, ecological functions, and documented cultural uses. By integrating ethnobotanical knowledge …

Data Repository For "The Influence Of Hydrologic And Salinity Conditions On Drought-Tolerant Great Salt Lake Wetland Plant Species" By Samantha Kurkowski And Karin Kettenring, Samantha Kurkowski

Browse all Datasets

This greenhouse experiment investigated the effects of salinity (3 levels) and hydrologic condition (5 levels),  on the cover and biomass of a single mix of 11 native drought- and salt-tolerant species.

Wavelet-Based Multiscale Analysis Of Cave Co₂ Concentration In Response To Short-Term High-Intensity Tourism Activities: Spatiotemporal Heterogeneity And Lag Characteristics, Mingda Cao, Wenwen Song, Yan Zhang, Jie Zhang, Zhiqiang Yao

International Journal of Speleology

High-intensity tourism activities can cause a significant increase in cave air CO₂ concentration, thereby affecting the cave micro-environment and secondary carbonate deposition. During the 2023 National Day Golden Week, high-frequency continuous monitoring of cave air CO₂ partial pressure (PCO_2(A)) and visitor numbers was conducted in Dawang Cave, Anhui Province. Wavelet transform and cross-correlation analyses were used to reveal the multi-scale response characteristics of CO₂ concentration to tourism activities. The results show that: (1) PCO_2(A) exhibited clear diurnal variations (higher during the day, lower at night) and decreased spatially with enhanced ventilation, controlled jointly by …

Mono Gold: An Informal Account Of The Geology, Production, And History Of Mono County Gold And Silver Mining Districts, D. D. Trent

Eastern Sierra History Journal

Mono Gold explores the mining production, technology, and history of the Eastern Sierra, with a special focus on Mono County. Author Dee Trent, a geologist, spent decades visiting, researching, and photographing each of the mining operations discussed in this book-length monograph.

Why Technical Readiness Is Not Enough: Institutional Barriers To Full Harvest Strategy Adoption In The International Pacific Halibut Commission, Evelyn Roozee, Owen Temby, Gordon M. Hickey

School of Earth, Environmental, & Marine Sciences Faculty Publications

Harvest strategies are increasingly promoted as a mechanism to reduce political discretion and align fisheries management with pre-agreed scientific objectives. While substantial progress has been made in tuna regional fisheries management organizations (RFMOs), non-tuna RFMOs have lagged behind. Existing research has focused primarily on technical modeling challenges, with comparatively limited attention to the governance dynamics shaping adoption. Using the International Pacific Halibut Commission (IPHC) as an instrumental case study, we examine the progress and delays in the development of a harvest strategy policy (HSP) through semi-structured interviews and participant observation. We find that the IPHC successfully addressed commonly cited barriers, …

Alaska Earthquake Center Quarterly Review October-December 2025, Heather Mcfarland, Beth Grassi, Austin Holland, Nate Murphy, Elisabeth Nadin, Carolyn Parcheta, Michael West

Alaska Earthquake Center Reports

This series of technical quarterly reports from the Alaska Earthquake Center (AEC) includes detailed summaries and updates on Alaska seismicity, the AEC seismic network and stations, fieldwork, our online presence, public outreach, and lists publications and presentations by AEC staff. Multiple AEC staff members contributed to this report.

The Role Of Heterogeneity In Earthquake Rupture Dynamics: Insights From Friction Experiments On A 1-Meter Laboratory Fault, Alejandro Aguilar

All Graduate Theses and Dissertations, Fall 2023 to Present

Tectonic faults are made of many kinds of rocks and minerals, creating natural weak and strong zones along faults where earthquakes occur. These differences can affect how faults move, including whether slip occurs slowly and quietly or suddenly and destructively during an earthquake. However, it is not fully understood how these variations influence when earthquakes start, how fast they spread, and whether they stop or grow into large ruptures. This research studies how different fault materials interact during earthquake slip. Using a large laboratory machine that simulates fault movement under realistic conditions, we recreate earthquake processes and closely measure how …

A Large And Robust Legless Lizard (Squamata, Anguinae) From The Gray Fossil Site Of Eastern Tennessee, Justice D. Lamer

Electronic Theses and Dissertations

The early Pliocene Gray Fossil Site in Tennessee preserved an abundance of microfossils, including numerous anguid lizard specimens. This includes the following elements: dentaries, a pterygoid fragment, a jugal, frontals, parietal fragments, dorsal and caudal vertebrae, and many osteoderms. Because these specimens had not been placed taxonomically beyond the subfamily level, comparative anatomy of similar elements from extant anguids and some quantitative data were used to provide more refined identifications. Using these methods, it was determined that a new, robust type of Ophisaurus is represented at the Gray Fossil Site. Important novel features include relatively robust dentaries, fewer but broader …

Evolution Of Propagator Wakes On The Kolbeinsey Ridge From An Integrated Geophysical Perspective, Ethan Stowell

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Oceanic lithosphere is formed following the extension and rifting of a continent, with new material generated at mid-ocean ridges. While ridges generally spread in the direction of extension, individual spreading centers are offset by perpendicular transform faults that break the ridges into individual segments. Ridge propagation, in which one ridge segment grows at the expense of another’s shortening, has been identified in global investigations as a poorly understood component of axial reorganization. This process leaves propagator wake structures composed of faults and pseudofaults visible as lows in Earth’s gravitational field, and transferred lithosphere with a distorted magnetic signature. This study …

Greenhouse Gas Flux Response In Biochar- And Compost-Amended Lawn Soils Under Simulated Water Saturation Conditions, Angel Salinas, Chu-Lin Cheng, Engil Pereira, Rafael M. Almeida, James Jihoon Kang

School of Earth, Environmental, & Marine Sciences Faculty Publications

Understanding greenhouse gas emission dynamics in lawn soils is important for improving climate change mitigation strategies in urban and suburban landscapes. In this greenhouse mesocosm study, carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) fluxes were measured from 12 turfgrass soil columns arranged in an unreplicated, completely randomized 4 × 3 factorial design. Four amendment treatments (biochar, compost, bio-com [1:1 volume ratio of biochar and compost], and unamended control) were combined with three water-table conditions (full saturation, half saturation, and unsaturated), with a single column representing each treatment combination. Columns were irrigated at 1 cm day−1 for 24 days, …

Technological Behaviour Of Pellets Containing Dried Green Crop, Christian Furll

IGC Proceedings (1977-2023)

Pelleted dried green crop presents essential advantages compared to chaff and meal as processing forms. Normally, the solidity of the pellets does not exceed the values required by animal feeding. Abrasion resulting from turnover processes is at present too high, particularly for the discharge of bins. Belt conveyors, vibrating conveyors, and bucket elevators are suitable to convey pellets. Storage of pellets over long periods has to be done by respecting prescribed climate conditions. Zones with excessive portion of abraded par­ticles in the storing pile are a preferred cause for self-heating. Slit-type dosing units as well as dosing units equipped with …

Results Of Comparative Investigations Into The Chevving And Ruminating Activities Of The Dairy Cow Fed Dried Forage From Grass And Leguminous Crops, B Piatkowski, S Nagel

IGC Proceedings (1977-2023)

The chewing and ruminating activities were studied of dairy cows fed grass, alfalfa, and straw of different physical forms. An electronic­ally controlled measuring device was applied. When feeding 8 kg of grass hay (32 % crude fibre in dry matter), the ruminating time was 5: 24 and 1 :49 hours (20,712 and 6,982 ruminat­ing movements) for chopped and ground + pelleted forages, respectively. It declined from 1 : 49 to 0: 0 l hours (from 6,929 to 70 move­ments) when hot-air dried alfalfa (23 % crude fibre) was fed in chopped and ground + pelleted forms, respectively. The ruminating time …

Feed Efficiency In Dairy Cows Of Roughages Preserved And Treated In Different Ways, M Zausch, E Boldt

IGC Proceedings (1977-2023)

Trials were conducted with dairy cows to investigate the feed efficiency of grass-clover mixture (wilted silage, silage made of fresh material with addition of foDTiic acid, artifi­cially dried forage, pellets with varying portions of straw). The results obtained allow to draw the following conclusions:

As regards dry matter intake, digestibility, and feed efficiency, grass-dover for wilted silage should be wilted to give a OM content not exceeding 40 %.

Pelleting artificially dried grass-clover mix­ture and its use in mixed rations together with other separately pelleted components should be avoided.

The best feed efficiency is reached when dried grass-clover is converted …

The Influence Of Dried And Ensiled Grass On Rumen Fermen­Tation, J Voigt, B Piatkowski

IGC Proceedings (1977-2023)

Rumen-fistulated cows were used to study the influence of the forage preservation technique on rumen fermentation and holdup time of the feed in the rumen. Cocksfoot (Dactylis glomerata) preserved as wilted silage or dried green crop was fed in the following variants: wilted silage alone; wilted silage + sugar beet + protein supplement; dried green crop alone; dried green crop + sugar beet + protein supplement. As compared with dried green crop, the shares of true protein and sugar in wilted silage were reduced from 9.8 • to 6.4 '.'I􀉧 and from 7.7 to 1.8 %in DM, respectively. In comparison …

Changes In Feeding Value Of Preserved Grass And Legumes By The Action Of High Temperatures, R Prym, F Weissbach

IGC Proceedings (1977-2023)

High temperatures acting on grass and legumes during preservation and storage, cause nutrient digestibility to deteriorate. Protein digestibility is likely to be most strongly affected. Digest­ibility measurements were performed on sheep to estimate the extent of heat damage suffered by dried green forage and silages. Various laboratory methods were applied for record­ing. such damage. The detennination of the acid-detergent insoluble crude protein portion proved a very suitable approach.

Growth And Nitrogen Retention Of Lambs Fed Alfalfa Dehy­Drated At Different Temperatures, H K. Goering

IGC Proceedings (1977-2023)

Alfalfa was dried at four temperatures ranging from 60 to 180 °C in two experiments to evaluate the effect on composition, diet di­gestibility, and growth by lambs. In Experi­ment I, the alfalfa was supplemented with 0.6 % salt and pelleted. In Experiment 2, alfalfa was supplemented with 24.4 % starch, 18.5% straw, 6% cane molasses, 0.5% sodium phosphate, and 0.6 % salt so that total nitrogen intake was not in excess of the protein require­ment for growth of the lambs. Cell wall, acid­detergent fiber, lignin, acid-detergent insoluble nitrogen, and pepsin insoluble nitrogen in­creased in the alfalfa dried at 180 °C. …

Non-Mechanical Field Losses In Wilting Grasses As Influenced By Different Factors, G Rucker, O Knabe

IGC Proceedings (1977-2023)

When wilting grasses, non-mechanical field losses of different extent may occur. The main factors influencing the extent of losses were: water content at cutting time, drying rate, temperature, amount of rain, swath den­sity, and content of water-soluble carbohy­drates in the crop.

The Effect Of Mechanical, Thermal And Chemical Treatment On The Loss Of Water From Cut Leaves Of Grasses, Colin Edward Harris

IGC Proceedings (1977-2023)

Laboratory experiments have demonstrated that cut grass -leaves have a high resistance to water loss, probably largely due to the imper­meability of the surface cuticle to water vapour. This resistance can be reduced and drying rate increased by thermal and mechanical treatment, and by exposure to the vapour of boiling petroleum ether. The effectiveness of formic acid and tri-n-butyl phosphate suggests the possibility of using chemicals to increase the drying rate of grass crops cut for hay and dried in the field.

Measures For Increasing The Efficiency Of Hot-Air Drying Of Forage, Siegfried Prufer, Gerd Neubert

IGC Proceedings (1977-2023)

In the GDR, the drying of wilted green forage as well as of whole plants of cereals and grain maize considerably improves the effi­ciency of hot-air drying as a whole. The proc­essing of wilted crop and the inclusion of whole-plant drying in the drying pattern cause the throughput to increase by 30 to 50% and fuel consurnption per ton of dried crop to de­crease by up to 50 %, in comparison with drying of fresh green forage containing 15 to 18 % dry matter. Hot-air drying is particularly suitable for feed production along industrial lines. -Being but little dependent on …

Gdr Standard Plant For Producing Feed Pellets On Straw Basis, Gerheard Schmidt

IGC Proceedings (1977-2023)

Following the international trend, livestock production units are growing in size. Straw, a major feed reserve, must be effectively utilized to meet the growing roughage requirements, especially of ruminants. Therefore, in the GDR a standard feed pelleting plant (type GF A) was developed and put to commercial production. The various machines and equipment em­ployed in the different stages of the GFA pellet­ing technology are explained in detail. The use of that standard feed pelleting plant shows the advantages of processing straw for semi-finished and finished feeds.

The Efficiency Of Producing And Feeding Complete-Ration Feed Briquets Containing Forage Chop, G V. Blagoveshcheski, V M. Sokolov

IGC Proceedings (1977-2023)

Production of forage chop from a clover­timothy mixture is efficient when harvesting the forage between the shooting of clover (35 to 40 cm stand height) and mid-flowering. For high-temperature drying, each vegetative stage of the plants requires a clearly defined regime. When establishing formulas for com­plete-ration feed briquets containing clover­timoihy chop harvested before clover budding, the protein/carbohydrate ratio must be bal­anced by supplementing the ration with 30 p.c. barley meal and 29 p.c. straw; when the mix­ture was harvested during budding, phos­phorus supplementation (one p.c. monocal­cium phosphate) is necessary, whilst the mix­ture harvested during flowering has to be supplemented with …

The Production Of Dry Feeds From Straw And Green Forage In The Gdr, Fritz Berg

IGC Proceedings (1977-2023)

In the GDR, at present about 9% of the feed energy requirement of cattle is covered by dry feeds, above all mechanically processed and chemically treated straw as well as dried green forages. This share is expected to rise to 15 % in forthcoming years. On the basis of technological fundamentals devised by animal nutritionists, corresponding production processes are being developed and perfected. They allow to convert the feedstuffs into a physical and chemical form favourable to high intake; in addition, the feeding value of high-fibre feedstuffs is improved. In this way, the feedstuffs are fed in favourable com­bination as …

Evaluation And Determination Off Actors Defining The Length Of Thin-Stalked Green Forage Chop, Peter Szendro

IGC Proceedings (1977-2023)

A more exact analysis of the length distribution of chopped material from thin-stalked green forage crops provides more information for the further processing of this material and for comparing the quality of work of the different technologies. Material cut into longer and less homoge­neous chop with heavier destruction of the green plant particles shows properties more suitable for further processing than chop harvested with a self-propelled precision-chop forage harvester. In consideration of the special importance of the questions discussed it seems advisable to continue the experiments and to perform them under production conditions as well; the results thus obtained will …

Organization Of Wilted Silage Production Along Industrial Lines In The Selbelang Inter-Farm Cooperative Crop Produc­Tion Division, Hunter Watzke, Karl Bachmann

IGC Proceedings (1977-2023)

The production of high-quality wilted silages on the basis of highly efficient machines and facilities for harvesting and preservation in the Selbelang inter-farm cooperative crop pro­duction division (KAP) is determined by the use of industrial methods of production. Ob­servance of optimum spans for harvesting forage to be used for the production of wilted silage, and the full utilization of machinery and facilities at rising levels of labour pro­ductivity and declining cost are achieved by way of complex and shift employment of machines, facilities, and workers. The size of machine complexes and their performance are dependent on the shape, equipment and …