John Patrick Abraham

John Patrick Abraham
University of St. Thomas - Minnesota | st thomas · Department of Engineering

PhD, Mechanical Engineering

About

357
Publications
231,556
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9,164
Citations
Additional affiliations
September 2001 - present
University of St. Thomas - Minnesota
Position
  • Professor (Full)

Publications

Publications (357)
Article
Seepage flow beneath the hydraulic structures creates uplift pressure on its floor that affects the performance of these structures. Prior studies have assumed that the cutoff wall is solid, however, perfect impermeability does not occur in the real world. This investigation yields an acceptable model for computing the relative uplift pressure at k...
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Heating in the ocean has continued in 2024 in response to increased greenhouse gas concentrations in the atmosphere, despite the transition from an El Niño to neutral conditions. In 2024, both global sea surface temperature (SST) and upper 2000 m ocean heat content (OHC) reached unprecedented highs in the historical record. The 0–2000 m OHC in 2024...
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A solar-power-based electrical system was designed to provide power to a small, remote village in Western Uganda. The purpose of the project was to electrify the village by providing lighting and electrical outlets for use with small electronic devices. The size of the village (fifty homes, one school, and one pharmacy) allowed a centrally position...
Article
Determining the uplift pressure at key points including the junctions of the floor and the cutoff wall beneath hydraulic structures and estimating the uplift force in these structures are vital issues in water engineering projects. The purpose of this study is to present a series of explicit and highly accurate formulas for determining these quanti...
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Scouring damage to piers is a major risk factor for hydraulic structures. In this research, a new eco-friendly method has been proposed to reduce both the length and depth of scouring near bridges and the volume of pits created by the removal of river-bed materials. Since clay and cationic polyacrylamide (PAM) have good compatibility with river sys...
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Evaluation of pore water pressure in conditions of a rapid draw-down of a reservoir water level is one of the most vital issues in the stability embankment dams. The purpose of this study is to investigate seepage flow and slope stability during the rapid draw-down of the reservoir water level for the Doiraj embankment dam. This dam is located in I...
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Flow hysteresis in a channel with a supercritical flow in the vicinity of a spindle-shaped bridge foundation (SSBF) with a change in flow rate has been investigated in a laboratory for the first time. Two spindle-shaped bridge foundations with diameters of 9 and 6.5 cm, which are placed at distances of 1.5 and 1 meter from the gate, have been used....
Article
Determining the factor of safety against sliding of slopes in engineering projects is a major challenges for civil engineers. A method that can provide an accurate estimation of sliding likelihood can be a significant aid to designers. In the first part of this study, formulae based on classical regression methods such as multiple linear regression...
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Ocean observational gridded products are vital for climate monitoring, ocean and climate research, model evaluation, and supporting climate mitigation and adaptation measures. This paper describes the 4th version of the Institute of Atmospheric Physics (IAPv4) ocean temperature and ocean heat content (OHC) objective analysis product. It accounts fo...
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The present research investigates K-Nearest Neighbor (K-NN) and Support Vector Machine (SVM) algorithms for evaluating hydraulic parameters of inclined drops equipped with fishway elements. 395 measurements were analyzed using these two algorithms with a focus on ΔE/E and y d /H. To evaluate algorithm effectiveness, three accuracy measures: R 2 , R...
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Ruptures of pipelines can result in dangerous fluids spreading toward populated areas. It is critical for designers to have tools that can accurately predict whether populated areas might be within a plume rupture zone. Numerical simulations using computational fluid dynamics (CFD) are compared here with experimental and real-world carbon dioxide r...
Preprint
Full-text available
Ocean observational gridded products are vital for climate monitoring, ocean and climate research, model evaluation, and supporting climate mitigation and adaptation measures. This paper describes the 4th version of the Institute of Atmospheric Physics (IAPv4) ocean temperature and ocean heat content (OHC) objective analysis product. It accounts fo...
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Viable renewable energy sources must be low-cost, easy to install, clean, and reliable if they are to meet the energy demand of urban or rural areas. Water is able to provide efficient sources of electrical energy among alternative renewable energy sources. Using modern hydraulic techniques, drinking water can be transported to the areas where it i...
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The global physical and biogeochemical environment has been substantially altered in response to increased atmospheric greenhouse gases from human activities. In 2023, the sea surface temperature (SST) and upper 2000 m ocean heat content (OHC) reached record highs. The 0–2000 m OHC in 2023 exceeded that of 2022 by 15 ± 10 ZJ (1 Zetta Joules = 1021...
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This study investigates the effects of gate openings and different sill widths on the sluice gate’s energy dissipation and discharge coefficient (Cd). The physical model of the sills includes rectangular sills of different dimensions. The results show that the gate opening size is inversely related to the Cd for a gate without a sill. In addition,...
Preprint
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Viable renewable energy sources are low-cost, easy to install, clean, and reliable energy sources that are able to meet the energy demand of urban or rural areas. Water resources are efficient sources of electrical energy among alternative renewable energy sources. Using modern hydraulic techniques, drinking water can be transported to the areas wh...
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In this research, the performance of the combination of a cable and a collar and their effect on scouring in single and pier groups in clear water conditions has been investigated. The piers have been tested in 3 groups: a single pier, a double pier group, and a triple pier group. In addition, studies were carried out with and without cables and co...
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Hypoxia-Inducible Factor-1α (HIF-1α) has presented a new direction for ischemic preconditioning of surgical aps to promote their survival. In a previous study, we demonstrated the effectiveness of HIF-1a DNA plasmids in this application. In this study, to avoid complications associated with plasmid use, we sought to express HIF-1α through mRNA tran...
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In this study, a nonstructural and eco-friendly solution has been used to reduce scouring downstream of screens. Upstream of the screen are stilling basins protected against scouring, but downstream locations are subjected to flow scouring. One of the challenges that the current research brings with it is the process of dispersing nanomaterials. In...
Preprint
Full-text available
Hypoxia-Inducible Factor-1α (HIF-1α) has presented a new direction for ischemic preconditioning of surgical flaps to promote their survival. In a previous study, we demonstrated the effectiveness of HIF-1a DNA plasmids in this application. In this study, to avoid complications associated with plasmid use, we sought to express HIF-1α through mRNA tr...
Article
Weirs are often used to measure discharge and control upstream water levels. The accurate estimation of flow discharge from circular-crested oblique weirs depends on the accurate estimation of the discharge coefficient (Cd). Therefore, presenting a method that can provide an accurate output of this important parameter would be a significant aid to...
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In the present study, the estimation of vertical settlement of earthen dams caused by earthquakes has been investigated using an artificial neural network model and wavelet-artificial neural network combination. The accuracy of the methods used based on the crest settlement data obtained from 13 types of dams and a total of 151 earth dams with eigh...
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As a major component of Earth’s energy budget, ocean heat content (OHC) plays a vital role in buffering climate change. The annual cycle is the most prominent change in OHC but has always been removed to study variations and changes in the Earth’s energy budget. Here we investigate the annual cycle of the upper 2000 m OHC at regional to global scal...
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The seepage reduction in embankment dams is essential to their stability and safety. This research aims to evaluate the effects of penetration depth (16, 18, 20, 22, 24 m), distance from the beginning of the crest width (0, 2, 4, 6, 8 m), and inclination angle (45°, 90°, 135°) of the internal cutoff wall on some of the design parameters in an emban...
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The purpose of this study is to investigate the trajectories of pressurized and free-falling jets and to determine their location downstream of the dam. The results show that the measured jet trajectory and the values extracted from the jet projectile equations are not the same. This discrepancy may be due to the effect of air resistance on flow; t...
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Timewise temperature variations in objects that are undergoing unsteady heating or cooling is a commonly encountered problem in the thermal sciences. One particular area of application is the cooling of a body post-death and the use of body temperatures to estimate the time of death. Here, a new approach based on the theory of transient heat transf...
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The near ubiquitous presence of numerical simulation has made case‐specific calculations of body temperatures following death possible so that accurate calculations of body temperatures can provide valuable information for estimating the time of death and can aid in forensic investigations. Here, a computational approach is described that has been...
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The water flow over a dam spillway has a lot of energy, and if this energy is not dissipated, the flowing water can cause damage to the dam and downstream structures. One way to dissipate this extra energy is to expel water jets into a plunging pool. In the present study, the trajectories of free-falling jets are investigated both numerically and e...
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Stepped spillways are suitable and economical options for high-storage dams that require significant energy dissipation, structural adaptation to roller-compacted concrete dams, and spontaneous flow aeration. In this study, a numerical analysis of the hydraulic characteristics for the skimming flow regime of the stepped spillway of Zirdan Dam is ca...
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Changes in ocean heat content (OHC), salinity, and stratification provide critical indicators for changes in Earth's energy and water cycles. These cycles have been profoundly altered due to the emission of greenhouse gasses and other anthropogenic substances by human activities, driving pervasive changes in Earth's climate system. In 2022, the wor...
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The present research was conducted to investigate the effect of sill geometry and sill width on the discharge coefficient and hydraulic jump characteristics. For this purpose, sills with semi-cylindrical, cylindrical, pyramidal, and rectangular cube geometries with widths of 0.075, 0.10, 0.15, and 0.2 m were installed under a sluice gate. Results s...
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Piles are walls that are installed underneath hydraulic structures to control seepage flow, uplift pressure, and exit hydraulic gradient. In this study, the effect of the ratio of width of the apron to the foundation depth (B/D), the ratio of the width of the apron to the downstream pile depth (B/d2), and the ratio of the upstream and downstream pi...
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In the present study, intelligent methods including artificial neural network (ANN) support vector machine (SVM) optimization and their combinations artificial neural network-particle swarm optimization (ANN-PSO), wavelet-artificial neural network (W-ANN), and W-ANN-PSO were investigated to predict the performance of rockfill dam crest settlements....
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A gridded ocean subsurface salinity dataset with global coverage is useful for research on climate change and its variability. Here, we explore the feed-forward neural network (FFNN) approach to reconstruct a high-resolution (0.25∘ × 0.25∘) ocean subsurface (1–2000 m) salinity dataset for the period 1993–2018 by merging in situ salinity profile obs...
Article
The current study deals with the depth of scour at the location of impact between a free fall jet and a riverbed. The current study is based on extensive laboratory experiments that were designed to mimic full-scale behavior. The literature review shows that relations among hydraulic parameters for predicting the depth of scour are complex, therefo...
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Changes in ocean heat content (OHC) provide a measure of ocean warming, with impacts on the Earth system. This Review synthesizes estimates of past and future OHC changes using observations and models. The top 2,000 m of the global ocean has significantly warmed since the 1950s, gaining 351 ± 59.8 ZJ (1 ZJ = 1021 J) from 1958 to 2019. The rate of w...
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New charts for temperature and heat loss in one-dimensional transient conduction situations have been created. In the new charts, time is scaled by a weighted sum of the lumped capacitance time scale tLC and the diffusion time scale tdiff: tref = atLC + btdiff, where a and b are constants. The new time scale becomes the lumped capacitance time scal...
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The present study aimed to investigate the effect of gabion structures with different lengths and heights in the downstream vertical drop on the energy dissipation values, relative depth, and downstream Froude number. Experiments were performed, for a simple vertical drop and a Gabion with two heights of 15 and 20 cm, Gabion structures with three r...
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Climate change is a complex process that exists at the intersection of many human endeavors [...]
Article
In this study, a series of laboratory tests were performed to investigate the effects of side ramp slope, crest length, and porous media properties on the flow regimes, water-surface profiles, discharge coefficients, and energy dissipation in embankment gabion weirs with upstream and downstream slopes. 24 physical models of solid and gabion weirs w...
Article
Sluice gates are commonly used to measure water discharge and to adjust the water level in open canals. Estimation of head loss (ΔE) and discharge coefficients (Cd) for a sluice gate is essential for the design of open canals. Depending on the downstream water level, free or submerged flow conditions may occur. Although there have been some investi...
Preprint
Full-text available
A gridded ocean subsurface salinity dataset with global coverage is useful for research on climate change and its variability. Here, we explore a machine learning approach to reconstruct a high-resolution (0.25° × 0.25°) ocean subsurface (0–2000 m) salinity dataset for the period 1993–2018 by merging in situ salinity profile observations with high-...
Article
The heat and mass transfer characteristics of a simple shear flow over a surface covered with staggered herringbone structures are numerically investigated using the lattice Boltzmann method. Two flow motions are identified. The first is a spiral flow oscillation above the herringbone structures that advects heat and mass from the top plane to herr...
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The aim of this study is to optimize the geometric dimensions of the Koyna concrete weight dam with and without seismic forces using the grasshopper optimizer algorithm (GOA). In the methodology section of this paper, the geometric parameters of the dam are provided as input data to an objective function minimizing the geometric dimensions and conc...
Article
Introduction Esophageal cancer is an aggressive malignancy with high mortality. Optimal treatment of esophageal cancer remains an elusive goal. Ribonucleic acid (RNA) interference is a novel potential targeted approach to treat esophageal cancer. Targeting oncogenes that can alter critical cellular functions with silencing RNA molecules is a promis...
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In a stepped spillway, the spillway face is provided with a series of steps from near the crest to the toe. This type of spillway is attractive for water resource management because it dissipates energy that is within the flow. When energy is dissipated by the steps, it reduces the energy reduction that otherwise must occur at the toe of the spillw...
Article
Full-text available
Weirs are structures that are important for measuring flow and controlling water levels. Research has shown that the discharge coefficient is not constant and depends on the crest length, the height of the weir, the upstream head, and the upstream and downstream slopes. In this study, the effect of these parameters on the discharge coefficient ( C...
Article
The ocean's thermal inertia is a major contributor to irreversible ocean changes exceeding time scales that matter to human society. This fact is a challenge to societies as they prepare for the consequences of climate change, especially with respect to the ocean. Here the authors review the requirements for human actions from the ocean's perspecti...
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This paper includes a comprehensive assessment of 40 models from the Coupled Model Intercomparison Project phase 5 (CMIP5) and 33 models from the CMIP phase 6 (CMIP6) to determine the climatological and seasonal variation of ocean salinity from the surface to 2000 m. The general pattern of the ocean salinity climatology can be simulated by both the...
Article
The increased concentrations of greenhouse gases in the atmosphere create an increase in Earth’s thermal energy, which is mainly stored in the ocean. Quantification of the rate of increase in ocean heat content (OHC) is vital for understanding the current and future climate of Earth. Linear trend lines have been frequently used to quantify long-ter...
Chapter
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Slope stability refers to the ability of inclined soil or rock slopes to withstand or undergo movement. The stability of slopes is a subject of study in soil mechanics, geotechnical engineering, and engineering geology. Analyses are generally aimed at understanding the causes of slope failure, or the factors that can potentially trigger a slope mov...
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Slide gates are generally used to adjust the flow in open canals. The discharge coefficient (Cd) for a slide gate is a function of the geometric and hydraulic characteristics of the gate. For free flow conditions, Cd depends on the upstream water level and opening of the gate, while for submerged flow, it also depends on the downstream water level....
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Discharge over an ogee weir is related to the length of the weir, upstream total head above the weir crest and the discharge coefficient. The discharge coefficient is influenced by several factors; in this study, some parameters that influence discharge coefficients of ogee weirs are investigated. These factors include: the weir upstream slope, apr...
Preprint
The heat and mass transfer characteristics in a simple shear flow over staggered herringbone structures are numerically investigated with the lattice Boltzmann method. Two flow motions are identified. The first is a spiral flow oscillation above the herringbone structures that advects heat and mass from the top plane to herringbone structures. The...
Article
Full-text available
In pressurized water distribution systems, a constant speed pump is often used because of its simplicity. However, constant speed pumps are not easily able to deal with changing demands in water flows. When the demand for the discharge differs from the design discharge, the required demand (discharge and head) could be met by changing the pump spee...
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Considering the importance of the effect of concrete arch dam body strength on their seismic performance, this research evaluated the effect of Young Modulus of both the body concrete and foundation as strength parameters and examines the responses to achieve the optimal body stiffness using probabilistic and uncertainty method. The ANSYS software...
Chapter
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Impermeable linings are frequently used to protect canal beds from erosion and to prevent seepage from the bottom or side of a canal. These linings are susceptible to a variety of issues, including damage caused by uplift pressure when the groundwater table is high. As a result, a drainage system beneath the canal's hard lining is required to reduc...
Chapter
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The advent of nanotechnology is an advancement that represents a fundamental change that will lead to the development of materials and tools in the future. The possibility of using nano-building blocks in size and composition is revolutionizing material science. Currently there are many ongoing studies of nanotechnology, its applications, benefits,...
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Microwave thermal ablation was developed as an alternative to other forms of thermal ablation procedures. The objective of this study is to numerically model a microwave ablation probe operating at the 2.45 GHz level using the finite element and finite volume methods to provide a comprehensive and repeatable study within a human male approximately...