Experimental Study of Explosion Mitigation by Deployed Metal Combined with Water Curtain

In this paper, protective barriers made of perforated plates with or without a water cover were investigated. In urban areas, such barriers could be envisaged for the protection of facades. An explosive-driven shock tube, combined with a retroreflective shadowgraph technique, was used to visualize the interaction of a blast wave profile with one or two plates made of expanded metal. Free-field air blast experiments were performed in order to evaluate the solution under real conditions. Configurations with either one or two grids were investigated. The transmitted pressure was measured on a wall placed behind the plate(s). It was observed that the overpressure and the impulse downstream of the plate(s) were reduced and that the mitigation performance increased with the number of plates. Adding a water layer on one grid contributed to enhance its mitigation capacity. In the setup with two plates, the addition of a water cover on the first grid induced only a modest improvement. This blast mitigation solution seems interesting for protection purposes.

Pengabdian Terhadap Masyarakat Pada Balita Menderita ISPA Menggunakan Terapi Komplementer Fisiotrapi Dada

ABSTRAK Infeksi pernafasan merupakan penyakit akut yang paling banyak terjadi pada anak-anak. Tujuan Deskripsi hasil Asuhan Keperawatan Komprehenshif Pada Balita Dengan Masalah Keperawatan Gangguan Bersih Jalan Nafas (Ispa) MenggunakanTerapi Komplementer menggunakan fisiotrapydadadidesabanjitkecamatanbanjitkabupatenwaykananTahun 2020 Metode yang di lakukan dengan Intervensi Fisioterapi dada yang di lakukan adalah Mengatur posisi pasien (tengkurap di pangkuan) dengan wajah menghadap ke baskom yang berisi air panas. Menutup kepala pasien dengan handuk kecil agar aroma minya kayu putih dapat terhidup dengan benar. Lakukan clapping dengan cara tangan perawat menepuk punggung secarabergantian.Lakukanperkusiselama1-2menit.Lakukanvibrasipada punggung pasien saat dahak keluar, Pada anak -anak, cukup 3 sampai 5 menit.Lakukansekitar4-5kali.kemudianbersihkanareamulutdanhidung pasien dengan tissue. Berikan minyak kayu putih pada punggung dan telapakkakipasien.HasilFisioterapidadayangdilakukanpadakeduaanak di dapatkan hasil yang dapat mengurangi lendir dijalan nafas. Sehingga keduaanakmerasakanlebihlegasertadapattidurlebihtenang.Dari3hari pelaksanaankeduaanakdalamintervensididapatkanhasilyangsamayakni pengeluaran dan perubahan membaik pada hari pertama, hal ini di karenakan usia anak tidak jauh berbeda, kemudian pelaksanaan diikuti anak denganbaik. Kata Kunci: Balita, ISPA, Terapi ABSTRACT Respiratory infections are the most common acute illness in children. Objective Description of the results of comprehensive nursing care in toddlers with nursing problems Clean Airway Disorders (Ispa) Using Complementary Therapy using chest physiotherapy in the banjit village banjit sub-district of Waykanan in 2020 Methods to be performed with the Intervention of Chest Physiotherapy that is done is to regulate the position of the patient (prone in the chest) in the banjit village lap) with face facing the basin filled with hot water. Cover the patient's head with a small towel so that the scent of eucalyptus can be alive properly. Clapping the nurse's hands alternately patting her back. Perform percussion for 1-2 minutes. Perform vibrations on the patient's back when sputum is out, in children, just 3 to 5 minutes. Do it about 4- 5 times. then clean the patient's mouth and nose area with tissue. Apply eucalyptus oil to the patient's back and feet. Results Chest physiotherapy done on the two children get results that can reduce mucus on the way of breath. So that both children feel more relievedandcansleepmorequietly.From3daystheimplementationofthe two children in the intervention obtained the same results namely expenditure and changes improved on the first day, this is because the age of the child was not much different, then the implementation was followed by the child well. Keywords: Toddlers, ISPA, Therapy

Clustering analysis for the hydro-geomorphometric characterization of the George River watershed (Nunavik, Canada)

<p>For remote and vast northern watersheds, hydrological data are often sparse and incomplete. Fortunately, remote sensing approaches can provide considerable information about the structural properties of watersheds, which is useful for the indirect assessment of their hydrological characteristics and behavior. Our main objective is to produce a high-resolution territorial clustering based on key hydrologic landscape metrics for the entire 42 000 km<sup>2</sup> George River watershed (GRW), located in Nunavik, northern Québec (Canada). This project is being conducted in partnership with the local Inuit communities of the GRW for the purpose of generating and sharing knowledge to anticipate the impact of climate and socio-environmental change in the GRW.</p><p>Our clustering approach employs Unsupervised Geographic Object-Based Image Analysis (GeOBIA) applied to the entire GRW with the subwatersheds as our objects of analysis. The landscape metric datasets used to generate the input variables of our GeOBIA classification are raster layers with a 30m x 30m pixel resolution. Topographic metrics are derived from a Digital Elevation Model (DEM) and include elevation, slopes, aspect, drainage density and watershed elongation. Land cover spectral metrics comprised in our analysis are the Normalized Difference Vegetation Index (NDVI), the Normalized Difference Moisture Index (NDMI) (Gao, 1996) and the Normalized Difference Water Index (NDWI) (McFeeters, 1996), which are all computed from a Landsat-8 cloud-free surface reflectance mosaic dating from 2015. Rasterized maps of surface deposit distribution and permafrost distribution, both produced by the Ministère des Forêts, de la Faune et des Parcs of Québec (MFFP), respectively constitute the surface and subsurface metrics of our GeOBIA.</p><p>The clustering algorithm used in this Unsupervised GeOBIA is the Fuzzy C-Means (FCM) algorithm. The FCM algorithm provides the objects a set of membership coefficients corresponding to each cluster. The greatest membership coefficient is then used to attribute the distinct subwatersheds to a cluster of watersheds with similar hydro-geomorphometric characteristics. The classification returns a Fuzzy Partition Coefficient (FPC), which describes how well-partitioned our dataset is. The FPC can vary greatly depending on the number of clusters we want to produce. Thus, we find the optimal number of clusters by maximizing the FPC.</p><p>Preliminary clustering results, computed only with topographic and land cover metrics, have identified two distinct watershed classes/clusters. In general, “Type 1” subwatersheds are clustered over the southern and northwestern portion of the GRW and are characterized by low to moderate elevation, high vegetation cover, high moisture and high surface water cover. Whereas “Type 2” subwatersheds located over the northeastern portion of the GRW are characterized by high elevation, low vegetation cover, low moisture and low surface water cover. These results will be refined with the use of additional metrics and will provide the detailed understanding necessary to assess how the hydrological regime of the river and its tributaries will respond to climate change, and how landscape change and human activities (e.g., planned mining development) may impact the water quality of the George River and its tributaries.</p>

Sentinel-1-Imagery-Based High-Resolution Water Cover Detection on Wetlands, Aided by Google Earth Engine

Saline wetlands experience large temporal fluctuations in water supply during the year and are recharged only or mainly through precipitation, meaning they are vulnerable to climate-change-induced aridification. Most passive satellite sensors are unsuitable for continuous wetland monitoring due to cloud cover and their relatively low temporal resolution. However, active satellite sensors such as the C-band synthetic aperture radar of Sentinel-1 satellites offer free, cloud-independent data. We examined surface water cover changes from October 2014 to November 2018 in the strictly protected area (13,000 ha) of the Upper-Kiskunság Alkaline Lakes region in the Danube–Tisza Interfluve in Hungary, with the aim of helping with nature protection planning. Changes and sensitivity can be defined based on the knowledge of variability. We developed a method for water cover detection based on automatic classification, applying the so-called WEKA K-Means clustering algorithm. For satellite data processing and analysis, we used the Google Earth Engine cloud processing platform. In terms of validation, we compared our results with the multispectral Modified Normalized Difference Water Index (MNDWI) derived from Landsat 8 and Sentinel-2 top-of-atmosphere reflectance images using a threshold-based binary classifier (receiver operator characteristics) for the MNDWI data. Using two completely distinct methods operating in distinct wavelength ranges, we obtained adequately matching results, with Spearman’s correlation coefficients (ρ) ranging from 0.54 to 0.80.

Effect of persistent water cover on soil structure, investigated on representative Hungarian soil samples

<p>Today, due to climate change, soil degradation processes related to extreme water supply situations (flood, inland water or drought) are occurring more and more frequently. Soil structure is one of the most important soil characteristics influencing many transport of materials (transport, storage of heat, gas, water and nutrients).Furthermore, it defines and ultimately determines the significant physical, chemical and biological processes involved and also the most important factor in agricultural crop production. Permanent water cover has a significant effect on soil structure, but the dynamics of disaggregation and the role of the soil factors influencing it is not yet fully understood. Our basic research aim is to investigate the effect of permanent water cover on soil structure on representative Hungarian soil samples. In our experiment, we sought to find the answer to the question of how long-term water coverage causes changes and damage to the soil structure under laboratory conditions by artificial water cover. We measured aggregate stability with Mastersizer 3000 Hydro LV laser diffractometry device and some soil chemistry parameters with Agilent 4210 MP-AES at different water cover times (selected in the literature). Based on experiences the effect of persistent water cover from the soil structure side can be most noticeable in the changes of macro- and microaggregate stability, as well as in the change of certain chemical parameters (e.g. calcium and iron content), thus, the aim of our research was to investigate these characteristics also. After compiling our results in a database, we evaluated and deduced statistical data on the long-term degradation effects of water cover. We also made an attempt to describe its disaggregation dynamics for different Hungarian soil types. Based on the results, we have selected the most sensitive soils for permanent water cover, which are also expected to be sensitive to extreme water management related to climate change.</p>

Long-Term Water Surface Area Monitoring and Derived Water Level Using Synthetic Aperture Radar (SAR) at Altevatn, a Medium-Sized Arctic Lake

Monitoring water storage in lakes and reservoirs is critical to water resource management, especially in a changing climate. Satellite microwave remote sensing offers a weather and light-independent solution for mapping water cover over large scales. We have used 13 years of synthetic aperture radar (SAR) data from three different sensors (Sentinel-1, RADARSAT-2, and Envisat advanced synthetic aperture radar (ASAR)) to develop a method for mapping surface water cover and thereby estimating the lake water extent (LWE). The method uses the unsupervised K-means clustering algorithm together with specific post-processing techniques to create binary maps of the water area. We have specifically tested and validated the method at Altevatn, a medium-sized arctic lake in Northern Norway, by using in-situ measurements of the water level. The multi-sensor SAR LWE time series were used in conjunction with the water level measurements to derive the lake hypsometry while at the same time quantifying the accuracy of our method. For Altevatn lake we estimated LWE with a root mean squared error (RMSE) of 0.89 km2 or 1.4% of the mean LWE, while the inferred lake water level (LWL) was associated with an RMSE of 0.40 m, or 2.5% of the maximum annual variation. We foresee that there is potential to further develop the algorithm by generalizing its use to other lakes worldwide and automating the process such that near real-time monitoring of LWE may be possible.

Landsat-Based Estimation of Seasonal Water Cover and Change in Arid and Semi-Arid Central Asia (2000–2015)

Surface water is of great importance to ecosystems and economies. Crucial to understanding hydrological variability and its relationships to human activities at large scales, open-access satellite datasets and big-data computational methods are now enabling the global mapping of the distribution and changes of inland water over time. A machine-learning algorithm, previously used only to map water at single points in time, was applied over 16 years of the USGS Landsat archive to detect and map surface water over central Asia from 2000 to 2015 at a 30-m, monthly resolution. The resulting dataset had an overall classification accuracy of 99.59% (±0.32% standard error), 98.24% (±1.02%) user’s accuracy, and 87.12% (±3.21%) producer’s accuracy for water class. This study describes the temporal extension of the algorithm and the application of the dataset to present patterns of regional surface water cover and change. The findings indicate that smaller water bodies are dramatically changing in two specific ecological zones: the Kazakh Steppe and the Tian Shan Montane Steppe and Meadows. Both the maximum and minimum extent of water bodies have decreased over the 16-year period, but the rate of decrease of the maxima was double that of the minima. Coverage decreased in each month from April to October, and a significant decrease in water area was found in April and May. These results indicate that the dataset can provide insights into the behavior of surface water across central Asia through time, and that the method can be further developed for regional and global applications.