Construction of mammographic findings simulators to study the interference of silicone implants in the diagnosis of breast cancer

Introduction: Breast cancer is the most prevalent malignant neoplasm among women, presenting itself, in 99% of cases, in females. Augmentation mammoplasty is the most performed aesthetic surgical intervention in the world. Objective: This study aims to improve the search for biomaterials compatible with mammographic findings suggestive of malignancy, to further study the interference of silicone implants in mammography exams. Methods: To make the simulators of mammographic findings, a bibliographic study of possible biomaterials that presented compatibility with the breast tissue and with possible neoplastic findings was carried out. The validation process of the simulators made in this work was carried out in two stages. Results: The result found was a density variation between 2.54 and 2.57 (dimensionless unit). For the second plate, the individual optical density of each material was analyzed. The results found for fiberglass ranged between 1.95 and 2.63. For chicken eggshells between 0.59 and 0.80. For the glycerin suppository, values between 1.43 and 2.29 were found. And for plastic PVC film 1.78 to 2.53. Conclusion: Given the above, it is observed that the first plate as a whole is compatible with mammographic studies. However, on the second plate, when the materials were analyzed separately, it was observed that fiberglass and plastic PVC film were the closest to compatibility with the commercial phantom, being compatible materials to simulate breast neoplasms in possible further studies.

Theoretical Investigation of Equilibrium Dynamics in Braided Gravel Beds for the Preservation of a Sustainable Fluvial Environment

Gravel bars have an important role in the exchange between surface and subsurface waters, in preventing and mitigating riverbank erosion, in allowing the recreational use of rivers, and in preserving fluvial or riparian habitats for species of fishes, invertebrates, plants, and birds. In many cases, gravel bars constitute an important substrate for the establishment and development of ground flora and woody vegetation and guarantee higher plant diversity. A sustainable management of braided rivers should, therefore, ensure their ecological potential and biodiversity by preserving a suitable braiding structure over time. In the present study, we propose an analytical–numerical model for predicting the evolution of gravel bars in conditions of dynamical equilibrium. The model is based on the combination of sediment balance equation and a regression formula relating dimensionless unit bedload rate and stream power. The results highlight the dependence of the evolving sediment particles’ pattern on the ratio of initial macro-bedforms longitudinal dimension to river width, which determines the gradual transition from advective and highly braiding to diffusive transport regime. Specifically, the tendency to maintain braiding and flow bifurcation is associated with equilibrium average bed profiles and, therefore, equilibrium average stream power characterized by the maximum period that does not exceed transverse channel dimension.

Analysis of morphometric data for drainage basins in Hafr Al Batin city, northeast of Saudi Arabia using GIS: تحليل المعطيات المورفومترية لأحواض التصريف بمدينة حفر الباطن - شمال شرق المملكة العربية السعودية باستخدام نظم المعلومات الجغرافية (GIS)

This study provides a geomorphological analysis of the properties of the valleys of the city of Hafr al-Batin using Geographic information systems (GIS) techniques that helped extract the parametric properties and the matrix properties used in the application of the SCS dimensionless Unit hydrograph to calculate the flow Peak of each valley. The results of the application of this model have shown that Seoul's studied valleys flow during periods varying from one water basin to another between 4.38 hours in the basin (1) F 26.44 hour in the tub (9) and at a size between 30.00 M 3/sec (1) F 257.58 M 3/sec in pelvis (10), and at speeds of between 1.50 m/sec (2) F (5 (f 2.37 m/sec in Basin (9)). The spatial analysis outputs of ARC GIS also assisted in the extraction of 12 morphological variables and 11 variable scales, which helped to classify studied streams by every variable.

Use of terraces to reduce overland flow and soil erosion, comparison of the HEC-HMS model and the KINFIL model application

In our study, a system of seven natural terraces interspersed with six field belts situated at the Knínice locality (the Ore Mts., North-West Bohemia) was selected as the experimental catchment area. Overland flow was computed using two different methods: the kinematic wave method and the SCS dimensionless Unit hydrograph (UH). For the kinematic wave method calculations the KINFIL software was used; for SCS dimensionless hydrograph the HEC-HMS software was applied. The results compare hydrographs with N-year recurrence of rainfall-runoff time, where N = 10, 20, 50, and 100 years. The comparison provides hydraulic results with terraces and without terraces computed using both mentioned software products. Although two different methods of overland flow computation were performed, the input data obtained from geodetic and hydrological measurements were identical. Results of the comparison are presented and discussed.

Research on SCS-CN in Lanhe Basin Distributed Rainfall Runoff Event

Based on the data from Basin hydrology, weather, runoff, land use, soil, DEM and with ARCGIS9.0 and WMS7.0 applications, SCS small basin hydrological model can be applied in Lanhe basin Distributed Hydrological Model. Within each sub-unit, net rainfall can be calculated with SCS-CN, and conflux using SCS dimensionless unit hydrograph, while river network flow concentration using subsection Muskingum method. By conducting the simulation of distributed rainfall runoff where measured runoff value are selected from 20 historical flood, the results indicate there are 14 values that are effective and the ratio comes to 70 percent. And there are 11 effective values after conflux test to the 14 floods where the ratio comes to 80 percent. The process of calculating runoff matches well with actual measure which indicates that the Distributed Hydrological Model is a scientific and precise model and can be applied to basin water flood forecast and water resource management.