scholarly journals A procedure for designing natural water retention measures in new development areas under hydraulic-hydrologic invariance constraints

2019 ◽  
Vol 50 (5) ◽  
pp. 1293-1308 ◽  
Author(s):  
Daniele Masseroni ◽  
Giulia Ercolani ◽  
Enrico Antonio Chiaradia ◽  
Claudio Gandolfi
Keyword(s):  
Natural Water ◽  
Water Retention ◽  
Curve Number ◽  
Design Storm ◽  
New Development ◽  
Storm Duration ◽  
Harvesting Systems ◽  
Correct Determination ◽  
Peak Runoff

Abstract In recent years, in Italy and elsewhere, regional regulations based on hydraulic-hydrologic invariance (HHI) principles have taken hold, especially for new development areas. Natural water retention measures (NWRMs) are among the most interesting options to provide the storage and infiltration capacities that are needed to achieve the HHI objectives. A procedure for the design of NWRMs in new development areas under HHI constraints is presented and is based on a simple combination of Soil Conservation Service Curve Number (SCS-CN) method for determining rainfall excess and lag-time method for simulating runoff propagation. Three types of NWRMs can be considered: rain barrels, drainage wells and drainage trenches; five types of synthetic hyetographs can be selected and three different approaches for the determination of critical storm duration applied. The results obtained by applying the procedure in a new development area located in northern Italy are illustrated and some general conclusions are drawn. It clearly emerges that practitioners should pay particular attention to the correct determination of design storm duration in order to avoid large underestimations of NWRMs size. Moreover, different combinations of the three NWRMs can provide the required reduction of peak of runoff after the transformation, but it appears that drainage trenches are more effective with respect to harvesting systems in reducing the peak runoff value.

scholarly journals Determination of potential retention of the Fryšávka River basin

2010 ◽  
Vol 58 (5) ◽  
pp. 263-270 ◽  
Author(s):  
Tomáš Mašíček ◽  
František Toman
Keyword(s):  
River Basin ◽  
Flood Control ◽  
Water Retention ◽  
Curve Number ◽  
Control Measures ◽  
Design Parameters ◽  
Software Products ◽  
Software Applications ◽  
Integrated Software

Hydrological models provide design parameters for the design of flood control measures. Runoff from the river basin is primarily determined by the amount of rainfall and water retention of the river basin. The Fryšávka River basin was chosen to determine the potential water retention of the river basin. Before the determination of potential retention preparatory work was carried out: description of the current state of land cover based on a detailed field survey, the representation of hydrological soil groups in the basin found in BPEJ (Bonitované půdně ekologické jednotky – Valuated land–ecological units) maps, delimitation of basin parts by the digital vector layer ZABAGED altimetry (Základní báze geografických dat – Fundamental base of geographic data) – 3D contour and evaluation of basin parts by the runoff curve numbers (CN). The processing of background data was performed by the program ArcGIS 9.2 of ArcView software products using a set of integrated software applications ArcMap, ArcCatalog and ArcToolbox. To assess the potential retention, as part of the hydrologic cha­ra­cte­ri­stics of the Fryšávka River basin, the curve number method, a modification of the deterministic episode model DesQ–MAXQ, was used. The average numbers of runoff curves and the data about potential retention of river basin parts are presented in the form of map outputs.

scholarly journals Manufacturing PLA/PCL Blends by Ultrasonic Molding Technology

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2412
Author(s):  
Inés Ferrer ◽  
Ariadna Manresa ◽  
José Alberto Méndez ◽  
Marc Delgado-Aguilar ◽  
Maria Luisa Garcia-Romeu
Keyword(s):  
Molecular Weight ◽  
Crystallization Rate ◽  
Raw Material ◽  
Small Particle Size ◽  
Polymer Mixtures ◽  
Crystallinity Degree ◽  
Correct Determination ◽  
Production Stages ◽  
Process Speed

Ultrasonic molding (USM) is a good candidate for studying the plasticization of polymer mixtures or other composite materials due to either the little amount of material needed for processing, low waste or the needed low pressure and residence time of the mold. Thus, the novelty of this research is the capability of USM technology to process PLA/PCL blends and their corresponding neat materials, encompassing all the production stages, from raw material to the final specimen. The major findings of the work revealed that the thermal properties of the blends were not affected by the USM process, although the crystallinity degree experienced variations, decreasing for PLA and increasing for PCL, which was attributed to the crystallization rate of each polymer, the high process speed, the short cooling time and the small particle size. The employed ultrasonic energy increased the molecular weight with low variations through the specimen. However, the degradation results aligned with the expected trend of these material blends. Moreover, this study also showed the effect pellet shape and dimensions have over the process parameters, as well as the effect of the blend composition. It can be concluded that USM is a technology suitable to successfully process PLA/PCL blends with the correct determination of process parameter windows.

Evaluation of methods for detection of β-lactamase production in MSSA

2021 ◽  
Author(s):  
Robert Skov ◽  
David R Lonsway ◽  
Jesper Larsen ◽  
Anders Rhod Larsen ◽  
Jurgita Samulioniené ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Confirmatory Test ◽  
Disc Diffusion ◽  
Broth Microdilution ◽  
Confirmatory Tests ◽  
Correct Determination ◽  
Primary Test ◽  
Zone Edge ◽  
Evaluation Of Methods

Abstract Objectives Correct determination of penicillin susceptibility is pivotal for using penicillin in the treatment of Staphylococcus aureus infections. This study examines the performance of MIC determination, disc diffusion and a range of confirmatory tests for detection of penicillin susceptibility in S. aureus. Methods A total of 286 consecutive penicillin-susceptible S. aureus blood culture isolates as well as a challenge set of 62 MSSA isolates were investigated for the presence of the blaZ gene by PCR and subjected to penicillin-susceptibility testing using broth microdilution MIC determination, disc diffusion including reading of the zone edge, two nitrocefin tests and the cloverleaf test. Results Using PCR-based detection of blaZ as the gold standard, both broth microdilution MIC testing and disc diffusion testing resulted in a relatively low accuracy (82%–93%) with a sensitivity ranging from 49%–93%. Among the confirmatory tests, the cloverleaf test performed with 100% accuracy, while zone edge interpretation and nitrocefin-based tests increased the sensitivity of β-lactamase detection to 96%–98% and 82%–96% when using MIC determination or disc diffusion as primary test, respectively. Conclusions This investigation showed that reliable and accurate detection of β-lactamase production in S. aureus can be obtained by MIC determination or penicillin disc diffusion followed by interpretation of the zone edge as a confirmatory test for apparently penicillin-susceptible isolates. The more cumbersome cloverleaf test can also be used. Nitrocefin-based tests should not be used as the only test for confirmation of a presumptive β-lactamase-negative isolate.

Sign in / Sign up

Export Citation Format

Share Document