scholarly journals Estimation of Water Loss Due to Evaporation in the El Cazadero Dam, Mexico, during a Drought

2021 ◽  
Vol 31 (1) ◽  
pp. 73-91
Author(s):  
Pedro Antonio Guido Aldana ◽  
Yves Alexis Pardavell Juárez ◽  
Pino Durán Escamilla
Keyword(s):  
Economic Value ◽  
Field Measurements ◽  
Theoretical Models ◽  
Water Evaporation ◽  
Severe Drought ◽  
Weather Station ◽  
Using Data ◽  
Daily Evaporation ◽  
Semi Empirical

In Mexico, large dams have been a critical component of the water supply. However, the places where they can be built are scarcer every day, a situation that adds to the high costs and social conflicts that they cause. Much of the water stored in dams is lost due to evaporation, so technological alternatives are currently being investigated to reduce it. Regarding the determination of evaporated volumes, data obtained with evaporimeters do not represent actual evaporation, being necessary to apply theoretical models in combination with field measurements to reach better approximations. The main objective of this research is to calculate the water evaporation in the El Cazadero dam located in the State of Zacatecas, Mexico, through Penman’s semi-empirical equation using data from the El Cazadero or 32006 weather station. The study area was selected due to its aridity and recurring drought problems that affect water availability. Evaporation results obtained from applying the theoretical model are compared with those reported by the weather station, showing a good correlation. In addition, results of the average daily evaporation are used to determine the approximate volume of water evaporated in the hydrological year between November 2010 and October 2011, when a severe drought occurred, whose magnitude and economic value indicates the necessity to carry out more research on this subject and propose public policies to develop and implement technological alternatives that mitigate this phenomenon.

scholarly journals Pulsation in pre-main sequence stars

2015 ◽  
Vol 11 (A29B) ◽  
pp. 552-559
Author(s):  
Konstanze Zwintz
Keyword(s):  
Stellar Evolution ◽  
Main Sequence ◽  
Theoretical Models ◽  
Oscillatory Behavior ◽  
Fundamental Parameters ◽  
Open Questions ◽  
Different Types ◽  
Model Independent ◽  
Using Data

AbstractAsteroseismology has been proven to be a successful tool to unravel details of the internal structure for different types of stars in various stages of evolution well after birth. We can now show that it has similar power for pre-main sequence (pre-MS) objects. Pre-MS stars with masses between ~1 and 6 solar masses that have recently been formed and gain their energy mainly from gravitational contraction can become vibrationally unstable during their evolution to the main sequence. Within the past ~15 years, several dozens of pulsating pre-MS stars were discovered using data obtained from ground and from space. Depending on their masses, pre-MS stars can show three different types of pulsations: (i) δ Scuti type p-mode pulsations, (ii) γ Doradus like g-mode oscillations and (iii) g-mode Slowly Pulsating B star pulsations.Our asteroseismic investigations yielded new insights into the connection between the pulsations and early stellar evolution: We revealed a relation between the stars' oscillatory behavior and their relative evolutionary stages that might lead us to a model-independent determination of the stars' fundamental parameters. With this we will be able to put constraints on theoretical models and help to answer some of the yet open questions in early stellar evolution.

KOMPARASI KINERJA KEUANGAN MELALUI PENDEKATAN ECONOMIC VALUE ADDED (EVA) PADA PERUSAHAAN TRANSPORTASI DI JAKARTA

2018 ◽  
Vol 3 ◽  
pp. 223-232
Author(s):  
Dwi Urip Wardoyo
Keyword(s):  
Financial Performance ◽  
Service Industry ◽  
Economic Value ◽  
Value Added ◽  
Added Value ◽  
Economic Value Added ◽  
Test Analysis ◽  
Transportation Service ◽  
Income Statement

This study aims to compare financial performance through profitability generated by two market participants in the witness transportation service industry in Jakarta, namely PT. BB compared to PT. ETU, this assessment is measured not limited to the profit generated but more than that by measuring financial added value through the concept of Eonomic Value Added produced by the two companies. The population in this study were all taxi transportation service companies in Jakarta. The sampling method selected two taxi companies that have the largest market share in DKI Jakarta, namely BB Taxi and ETU Taxi. The test analysis used in this study is ratio analysis through profit calculation and economic added value from the annual income statement. This study shows that there are (a) determination of the ratio of profit levels, (b) Determination of the comparison of economic value added of the two companies. Keywords :  Financial performance, Economic Value Added (EVA)

scholarly journals The Concept of Accuracy Analysis of the Vertical Displacements Gained from the Hydrostatic Levelling Systems’ Measurements

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4842
Author(s):  
Waldemar Kamiński
Keyword(s):  
Accuracy Assessment ◽  
Theoretical Models ◽  
Vertical Displacement ◽  
Serial Connection ◽  
Vertical Displacements ◽  
Comprehensive Determination ◽  
The One ◽  
The Individual ◽  
Reference Sensor

Nowadays, hydrostatic levelling is a widely used method for the vertical displacements’ determinations of objects such as bridges, viaducts, wharfs, tunnels, high buildings, historical buildings, special engineering objects (e.g., synchrotron), sports and entertainment halls. The measurements’ sensors implemented in the hydrostatic levelling systems (HLSs) consist of the reference sensor (RS) and sensors located on the controlled points (CPs). The reference sensor is the one that is placed at the point that (in theoretical assumptions) is not a subject to vertical displacements and the displacements of controlled points are determined according to its height. The hydrostatic levelling rule comes from the Bernoulli’s law. While using the Bernoulli’s principle in hydrostatic levelling, the following components have to be taken into account: atmospheric pressure, force of gravity, density of liquid used in sensors places at CPs. The parameters mentioned above are determined with some mean errors that influence on the accuracy assessment of vertical displacements. In the subject’s literature, there are some works describing the individual accuracy analyses of the components mentioned above. In this paper, the author proposes the concept of comprehensive determination of mean error of vertical displacement (of each CPs), calculated from the mean errors’ values of components dedicated for specific HLS. The formulas of covariances’ matrix were derived and they enable to make the accuracy assessment of the calculations’ results. The author also presented the subject of modelling of vertical displacements’ gained values. The dependences, enabling to conduct the statistic tests of received model’s parameters, were implemented. The conducted tests make it possible to verify the correctness of used theoretical models of the examined object treated as the rigid body. The practical analyses were conducted for two simulated variants of sensors’ connections in HLS. Variant no. I is the sensors’ serial connection. Variant no. II relies on the connection of each CPs with the reference sensor. The calculations’ results show that more detailed value estimations of the vertical displacements can be obtained using variant no. II.

scholarly journals Drone-Based Remote Sensing for Research on Wind Erosion in Drylands: Possible Applications

2021 ◽  
Vol 13 (2) ◽  
pp. 283
Author(s):  
Junzhe Zhang ◽  
Wei Guo ◽  
Bo Zhou ◽  
Gregory S. Okin
Keyword(s):  
Remote Sensing ◽  
Wind Erosion ◽  
Field Measurements ◽  
Spatially Explicit ◽  
Surface Model ◽  
High Resolution Imagery ◽  
Soil Elevation ◽  
3D Photogrammetry ◽  
Using Data ◽  
Sample Set

With rapid innovations in drone, camera, and 3D photogrammetry, drone-based remote sensing can accurately and efficiently provide ultra-high resolution imagery and digital surface model (DSM) at a landscape scale. Several studies have been conducted using drone-based remote sensing to quantitatively assess the impacts of wind erosion on the vegetation communities and landforms in drylands. In this study, first, five difficulties in conducting wind erosion research through data collection from fieldwork are summarized: insufficient samples, spatial displacement with auxiliary datasets, missing volumetric information, a unidirectional view, and spatially inexplicit input. Then, five possible applications—to provide a reliable and valid sample set, to mitigate the spatial offset, to monitor soil elevation change, to evaluate the directional property of land cover, and to make spatially explicit input for ecological models—of drone-based remote sensing products are suggested. To sum up, drone-based remote sensing has become a useful method to research wind erosion in drylands, and can solve the issues caused by using data collected from fieldwork. For wind erosion research in drylands, we suggest that a drone-based remote sensing product should be used as a complement to field measurements.

scholarly journals Laboratory and In Situ Determination of Hydraulic Conductivity and Their Validity in Transient Seepage Analysis

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1131
Author(s):  
Soonkie Nam ◽  
Marte Gutierrez ◽  
Panayiotis Diplas ◽  
John Petrie
Keyword(s):  
Hydraulic Conductivity ◽  
Field Measurements ◽  
Natural Soil ◽  
In Situ Tests ◽  
Seepage Analysis ◽  
Soil Deposits ◽  
Seepage Modeling ◽  
Sample Disturbance

This paper critically compares the use of laboratory tests against in situ tests combined with numerical seepage modeling to determine the hydraulic conductivity of natural soil deposits. Laboratory determination of hydraulic conductivity used the constant head permeability and oedometer tests on undisturbed Shelby tube and block soil samples. The auger hole method and Guelph permeameter tests were performed in the field. Groundwater table elevations in natural soil deposits with different hydraulic conductivity values were predicted using finite element seepage modeling and compared with field measurements to assess the various test results. Hydraulic conductivity values obtained by the auger hole method provide predictions that best match the groundwater table’s observed location at the field site. This observation indicates that hydraulic conductivity determined by the in situ test represents the actual conditions in the field better than that determined in a laboratory setting. The differences between the laboratory and in situ hydraulic conductivity values can be attributed to factors such as sample disturbance, soil anisotropy, fissures and cracks, and soil structure in addition to the conceptual and procedural differences in testing methods and effects of sample size.

scholarly journals Solubilization of Trans-Resveratrol in Some Mono-Solvents and Various Propylene Glycol + Water Mixtures

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3091
Author(s):  
Mohammed Ghazwani ◽  
Prawez Alam ◽  
Mohammed H. Alqarni ◽  
Hasan S. Yusufoglu ◽  
Faiyaz Shakeel
Keyword(s):  
Propylene Glycol ◽  
Mole Fraction ◽  
Bioactive Compound ◽  
Theoretical Models ◽  
Solubility Parameters ◽  
Hansen Solubility Parameters ◽  
Neat Water ◽  
Dissolution Properties ◽  
Hansen Solubility

This research deals with the determination of solubility, Hansen solubility parameters, dissolution properties, enthalpy–entropy compensation, and computational modeling of a naturally-derived bioactive compound trans-resveratrol (TRV) in water, methanol, ethanol, n-propanol, n-butanol, propylene glycol (PG), and various PG + water mixtures. The solubility of TRV in six different mono-solvents and various PG + water mixtures was determined at 298.2–318.2 K and 0.1 MPa. The measured experimental solubility values of TRV were regressed using six different computational/theoretical models, including van’t Hoff, Apelblat, Buchowski–Ksiazczak λh, Yalkowsly–Roseman, Jouyban–Acree, and van’t Hoff–Jouyban–Acree models, with average uncertainties of less than 3.0%. The maxima of TRV solubility in mole fraction was obtained in neat PG (2.62 × 10−2) at 318.2 K. However, the minima of TRV solubility in the mole fraction was recorded in neat water (3.12 × 10−6) at 298.2 K. Thermodynamic calculation of TRV dissolution properties suggested an endothermic and entropy-driven dissolution of TRV in all studied mono-solvents and various PG + water mixtures. Solvation behavior evaluation indicated an enthalpy-driven mechanism as the main mechanism for TRV solvation. Based on these data and observations, PG has been chosen as the best mono-solvent for TRV solubilization.

Combined Experimentaland Theoretical Determination of the Atomic Structure of the (310) Twin in NB

1991 ◽  
Vol 238 ◽  
Author(s):  
Geoffrey H. Campbells ◽  
Wayne E. King ◽  
Stephen M. Foiles ◽  
Peter Gumbsch ◽  
Manfred Rühle
Keyword(s):  
High Resolution ◽  
Theoretical Models ◽  
High Resolution Electron Microscopy ◽  
Interatomic Potentials ◽  
Image Simulation ◽  
Theoretical Determination ◽  
Atomic Structures ◽  
Resolution Electron ◽  
High Resolution Images

ABSTRACTA (310) twin boundary in Nb has been fabricated by diffusion bonding oriented single crystals and characterized using high resolution electron microscopy. Atomic structures for the boundary have been predicted using different interatomic potentials. Comparison of the theoretical models to the high resolution images has been performed through image simulation. On the basis of this comparison, one of the low energy structures predicted by theory can be ruled out.

Micro Roughness Determination Of Periodic Microelectronics Structures Using Optical Far Field Measurements

2011 ◽  
Author(s):  
Alexandre Vauselle ◽  
Philippe Maillot ◽  
Gaëlle Georges ◽  
Carole Deumié ◽  
David G. Seiler ◽  
...  
Keyword(s):  
Field Measurements ◽  
Far Field
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