scholarly journals Stochastic simulation and prediction of turbidity dynamics in karst systems. Case study: Mokra karst spring (SE Serbia)

2021 ◽  
Vol 82 (3) ◽  
pp. 222-224
Author(s):  
Veljko Marinović ◽  
Branislav Petrović
Keyword(s):  
Stochastic Simulation ◽  
Warning System ◽  
Simulation Models ◽  
Karst Spring ◽  
Timely Response ◽  
Karst Systems ◽  
Groundwater Source ◽  
Source Management

Characterization of a karst system includes the analysis of two components – quantitative and qualitative one. Forecasting of future values of groundwater parameters can be very useful in defining the amounts of water needed for a reliable water supply. Stochastic simulation and forecasting were carried out for time series of precipitation and Mokra karst spring turbidity recorded in 2015. Simulation models within groundwater management would have a function in the early warning system which will enable timely response of groundwater source management.

scholarly journals Caracterização espacial de um índice de produtividade nos povoamentos de pinheiro-bravo em Portugal

Finisterra ◽  
2012 ◽  
Vol 38 (75) ◽  
Author(s):  
Cristina Santos ◽  
José Almeida
Keyword(s):  
Spatial Distribution ◽  
Stochastic Simulation ◽  
National Forest Inventory ◽  
Study Data ◽  
Maritime Pine ◽  
Productivity Index ◽  
Spatial Continuity ◽  
Spatial Characterization

SPATIAL CHARACTERIZATION OF A PRODUCTIVITY INDEX OF MARITIME PINE IN PORTUGAL. Forestry plays an important role in the Portuguese regional economy. With this in mind, it is clear that robust and consistent modelling techniques are required so that all decisions can be scientifically based. This work aims to calculate maps illustrating the spatial distribution of the productivity index of maritime pine in Portuguese forests, using geostatistical algorithms of stochastic simulation in association with GIS and spatial analysis functions. These geostatistical algorithms enable this productivity index to be inferred for the locations where this species occurs, but without sampling observations. In this particular case study, data were provided by the third National Forest Inventory of the State Forest Administration. Based on measurements collected in sampling plots, of the height and age of dominant trees, a productivity index was calculated, summarizing the growth gradient level per year. Experimental variograms showed that the productivity index treated as a categorical variable with five classes does not reveal any spatial continuity. On the other hand, the two components of the index – height and age of the trees – present a spatial structure displayed by long-range variograms. Hence, instead of dealing with the productivity index, the decision was made to characterize the spatial distribution of these two factors and to compose the index as the final step. Thus, a methodology is used for the joint spatial characterization of the height and age of maritime pine prior to the calculation of a productivity index. One of the main advantages of stochastic simulation methodologies is the ability to assess the local uncertainty (related to sampling density, location of the nearest samples and local variability), as well as to map the probability of occurrence of extreme scenarios (in this case study, for instance, excellent or unproductive areas). These methodologies are major tools for the sustainable planning and management of natural resources, making it possible to delimit areas of greater and lesser suitability for each type of forest and to understand better the influence of factors that really affect tree development and growth.

Case study: Experimental characterization of noise and vibration sources in a refrigerator

2021 ◽  
Vol 69 (6) ◽  
pp. 477-489
Author(s):  
Roberto Zárate Espinosa ◽  
Jordi Poblet-Puig ◽  
Martín Ortega Breña ◽  
Marcelo López Parra
Keyword(s):  
Energy Analysis ◽  
Simulation Models ◽  
Acoustic Energy ◽  
Experimental Characterization ◽  
Laboratory Measurements ◽  
Acoustic Intensity ◽  
Noise And Vibration ◽  
Acoustic Design

The sources of noise and vibration of a refrigerator are characterized by means of laboratory measurements. Three different elements are considered: compressor, evaporator fan, and condenser fan. Both the radiated acoustic energy and the mechanical power injected to the refrigerator structure are measured. Acoustic intensity maps on the refrigerator faces at different frequencies are also provided They are helpful in visualizing the more problematic zones in terms of noise emis- sion. The devices are tested in vacuo or working inside the refrigerator. The provided information can be used as input data for vibroacoustic simulation models such as statistical energy analysis. It is also of interest in order to improve the refrigerator acoustic design.

scholarly journals The Effects of Explicit versus Parameterized Convection on the MJO in a Large-Domain High-Resolution Tropical Case Study. Part I: Characterization of Large-Scale Organization and Propagation*

2013 ◽  
Vol 70 (5) ◽  
pp. 1342-1369 ◽  
Author(s):  
Christopher E. Holloway ◽  
Steven J. Woolnough ◽  
Grenville M. S. Lister
Keyword(s):  
High Resolution ◽  
Large Scale ◽  
Propagation Speed ◽  
Simulation Models ◽  
Horizontal Resolution ◽  
Convective Heating ◽  
Convection Model ◽  
Boundary Layer Scheme

Abstract High-resolution simulations over a large tropical domain (~20°S–20°N, 42°E–180°) using both explicit and parameterized convection are analyzed and compared to observations during a 10-day case study of an active Madden–Julian oscillation (MJO) event. The parameterized convection model simulations at both 40- and 12-km grid spacing have a very weak MJO signal and little eastward propagation. A 4-km explicit convection simulation using Smagorinsky subgrid mixing in the vertical and horizontal dimensions exhibits the best MJO strength and propagation speed. Explicit convection simulations at 12 km also perform much better than the 12-km parameterized convection run, suggesting that the convection scheme, rather than horizontal resolution, is key for these MJO simulations. Interestingly, a 4-km explicit convection simulation using the conventional boundary layer scheme for vertical subgrid mixing (but still using Smagorinsky horizontal mixing) completely loses the large-scale MJO organization, showing that relatively high resolution with explicit convection does not guarantee a good MJO simulation. Models with a good MJO representation have a more realistic relationship between lower-free-tropospheric moisture and precipitation, supporting the idea that the moisture–convection feedback is a key process for MJO propagation. There is also increased generation of available potential energy and conversion of that energy into kinetic energy in models with a more realistic MJO, which is related to larger zonal variance in convective heating and vertical velocity, larger zonal temperature variance around 200 hPa, and larger correlations between temperature and ascent (and between temperature and diabatic heating) between 500 and 400 hPa.

Construction of plastic contact deformation maps on ceramics: a case study on aluminum nitride

1996 ◽  
Vol 54 ◽  
pp. 636-637
Author(s):  
D. L. Callahan
Keyword(s):  
Plastic Deformation ◽  
Aluminum Nitride ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Bright Field Image ◽  
Perfectly Plastic ◽  
Contrast Analysis ◽  
Deformation Patterns

Modern polishing, precision machining and microindentation techniques allow the processing and mechanical characterization of ceramics at nanometric scales and within entirely plastic deformation regimes. The mechanical response of most ceramics to such highly constrained contact is not predictable from macroscopic properties and the microstructural deformation patterns have proven difficult to characterize by the application of any individual technique. In this study, TEM techniques of contrast analysis and CBED are combined with stereographic analysis to construct a three-dimensional microstructure deformation map of the surface of a perfectly plastic microindentation on macroscopically brittle aluminum nitride.The bright field image in Figure 1 shows a lg Vickers microindentation contained within a single AlN grain far from any boundaries. High densities of dislocations are evident, particularly near facet edges but are not individually resolvable. The prominent bend contours also indicate the severity of plastic deformation. Figure 2 is a selected area diffraction pattern covering the entire indentation area.

Integrating The Geophysical Characterization Of Seismic Thin Beds With Stochastic Reservoir Modeling: A Case Study From The Kutei Basin (Offshore Kalimantan, Indonesia)

2011 ◽  
Author(s):  
Giorgio Rocco Cavanna ◽  
Ernesto Caselgrandi ◽  
Elisa Corti ◽  
Alessandro Amato del Monte ◽  
Massimo Fervari ◽  
...  
Keyword(s):  
Reservoir Modeling ◽  
Geophysical Characterization

Failure Analysis of CDM-ESD Damage in a GaAs RFIC

2000 ◽  
Author(s):  
Amy Poe ◽  
Steve Brockett ◽  
Tony Rubalcava
Keyword(s):  
Radio Frequency ◽  
Failure Analysis ◽  
Integrated Circuit ◽  
Production Test ◽  
Analysis Techniques ◽  
Device Model ◽  
Charged Device ◽  
Subsequent Failure

Abstract The intent of this work is to demonstrate the importance of charged device model (CDM) ESD testing and characterization by presenting a case study of a situation in which CDM testing proved invaluable in establishing the reliability of a GaAs radio frequency integrated circuit (RFIC). The problem originated when a sample of passing devices was retested to the final production test. Nine of the 200 sampled devices failed the retest, thus placing the reliability of all of the devices in question. The subsequent failure analysis indicated that the devices failed due to a short on one of two capacitors, bringing into question the reliability of the dielectric. Previous ESD characterization of the part had shown that a certain resistor was likely to fail at thresholds well below the level at which any capacitors were damaged. This paper will discuss the failure analysis techniques which were used and the testing performed to verify the failures were actually due to ESD, and not caused by weak capacitors.

dC/dV and CV Characterization of Gate Resistance Defects in eDRAM Circuits

2013 ◽  
Author(s):  
Sweta Pendyala ◽  
Dave Albert ◽  
Katherine Hawkins ◽  
Michael Tenney
Keyword(s):  
Deep Submicron ◽  
Work Flow ◽  
Localization Technique ◽  
Characterization Techniques ◽  
Capacitance Voltage ◽  
Gate Resistance

Abstract Resistive gate defects are unusual and difficult to detect with conventional techniques [1] especially on advanced devices manufactured with deep submicron SOI technologies. An advanced localization technique such as Scanning Capacitance Imaging is essential for localizing these defects, which can be followed by DC probing, dC/dV, CV (Capacitance-Voltage) measurements to completely characterize the defect. This paper presents a case study demonstrating this work flow of characterization techniques.

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