Geochemical indicators of a biogenic component in source materials of moldavites

ABSTRACT Formation of the Central European tektites, known as moldavites, has been associated with a large meteorite impact in southern Germany 14.8 m.y. ago. The geochemical link between moldavites and their source materials, and the processes of their possible chemical differentiation still remain uncertain. Some differences in chemical composition between moldavites and sediments of corresponding age from the surroundings of the Ries crater could be explained by a hypothesis according to which biomass covering the pre-impact area contributed to the source materials. In a comparison of the geochemical compositions of a large representative set of moldavites and suitable Ries sediments, enrichment in elements K, Ca, Mg, and Mn and depletion of Na in moldavites, similar to redistribution of these elements during their transfer from soil to plants, could indicate the unconventional biogenic component in moldavite source materials. Simple mixing calculations of the most suitable Ries sediments and a model biogenic component represented by burned biomass residue are presented. The plausibility of the estimated biomass contribution considering reconstructions of the middle Miocene paleoenvironment in the pre-impact Ries area is discussed. No significant vapor fractionation is required to explain the observed variability of moldavite chemical composition.

Environmental Sanitation in Heredia

Costa Rica is recognized for its efforts in sustainable development. This study analyzes the challenges of environmental sanitation to articulate environmental management in the Canton of Heredia. Currently, the country faces significant challenges regarding access to water and environmental sanitation. This research contributes to the analysis of the challenges of the environmental sanitation system in this territory. The testing techniques and photographic registration in the impact area, along with the interviews with employees and professionals on the subject, and extensive bibliographic consultation support this methodology. The study's conclusions regarding the challenges of environmental sanitation are 1) legal and institutional framework faced by the environmental sanitation project of the Publics Services Company of Heredia (ESPH for its initials in Spanish), 2) strategy for the treatment of sanitary waters in the canton, and 3) improvement in the quality of life of the Heredia's citizens.

Modeling of the Dark Phase of Flight and the Impact Area for Meteorites of Real Shapes

Aims. The complex dynamics of bodies, originating from the interplanetary matter and passing through Earth’s atmosphere, defines their further position, velocity, and final location on Earth’s surface in the form of meteorites. One of the important factors that affect the movement of a body in the atmosphere is its shape and orientation. Our goal is to model the interaction of real shape meteoroids with Earth’s atmosphere and compare the results with the standard spherical body approach. Methods. In the simulation, we use 3D models of fragments of the Košice meteorite with different sizes and shapes. Using a 3D model of fragments, we consider the real shape of the body to define its resistance properties during atmospheric transition more specifically. The simulation is performed using virtual wind tunnel in the MicroCFD (Computational Fluid Dynamics) software to obtain more realistic drag coefficients and using the µ(m)-Trajectory software to model the particle trajectory in the atmosphere including the wind profile. The final outputs from these programs are the drag coefficient as a function of the altitude and the particle orientation. Using these parameters we get the more realistic body trajectory and the impact area coordinates. Comparison of the results for real and spherical model meteorite impact location is discussed. Results. Simulation showed significant differences in trajectory and the impact area for the different real body orientations compared to the spherically symmetric body. Also, an important result is a difference in the impact area of the real body with a specific orientation without rotation and the body with considered rotation. The significant difference between the modeled impact of a real shape body and its real place of finding compared to a spherically symmetric body indicates the importance of the method used.

The impacts of cognitive biases and heuristics on Covid-19 preventive behaviors

The covid-19 pandemic disease became part of the study of many scientific disciplines recently since its impact area is large and it threatened millions of lives. One of the important disciplines is public policy since the characteristics may easily influence the spread of covid-19. It is assumed that an individual’s irrational tendencies can increase this spread since they are highly correlated with the most important actions of prevention of the spread such as isolation, wearing a mask, and washing hands. Moreover, public policies can be effective in such a pandemic period if they take into consideration of individual’s irrational tendencies. Hence, in this study the psychological background of why individuals do not follow the regulations that can decrease the spread of covid-19 will be presented: cognitive biases and heuristics.

Flash Flood Characteristics of Ciberang River, Its Impact and Mitigation

Flash flood is a deadly natural disaster that develops at space and time scales caused by high rainfall intensities and frequently occurs. It occurs in mountainous regions with steep slope relief and often causes a loss of economy, society, and environment and threatens human lives. The Ciberang river is located at Lebak district, Banten Province, and has been experiencing a significant flash flood from December 31, 2019 to January 01, 2020, which contributed to various damages, including households nearby the river. In this study, the impact areas were identified with the HEC-RAS model and satellite image data. The impact area was damage on eight sub-districts, including agriculture (77.86 Ha), buildings (0.80 Ha), roads (2.5 km), and nine bridges. In addition, this study tried to build Sabo Dam upstream of Banjar Irigasi sub-districts to respond to the flash flood occurrence. The results have reduced the discharge to around 40 m3/s, and the travel time was delayed about 53 min. The results of this study help the community and decision-makers be ready for further flash flood disasters.

Sand Net Device to Control the Meanders of a Coastal River: The Case of the Authie Estuary (France)

The Authie estuary is characterized by an important southern sand spit and a northern shoreline subject to strong erosion due to the meandering of the coastal river. In order to reduce this erosion, a new soft coastal defence, namely the sand net device (SND), has been implemented inside the Authie estuary. It consists of several nets assembled in an inverted V creating a porous structure and thus trapping sand as shoreline protection. However up to now, little proof has been provided on the explicit influence of this SND on the hydrodynamic pattern and associated morphodynamics. In this paper, field surveys of morphological developments combined with numerical modelling (Telemac-2D/3D) analyze the influence of the SND into flow pattern and morphodynamics. In situ monitoring clearly points out sedimentation around the SND and a deepening of the main channel. Modelling results show that, without SND, erosion is observed around its location. With a SND implemented, the velocity has been reduced and created a deviation in its direction by a circulation around the SND location. The impact area of the structure is around 500 m in both directions, upstream and downstream part.

Effect of Hammer Shape and Impact Area on Hammer Mill Performance under Different Feed Rates

The research aims to compare the performance (PC) and specific energy consumption (Spc.) of the hammer mill when using the T-hammer against the (traditional) rectangular hammer. A homemade mill with four hammers was used in experiment. 36 treatments: 2 hammer shape x 3 impact area (840, 720 and 960 mm2) x 2 feeding rates (1500 and 3000 g min-1) x 3 replicates, with completely random design. The results showed that there was no significant effect of hammer shape on PC at the feed rate of 3000 g min-1, while there was an effect at the rate of 1500 g min-1. An effect was also found for the impact area on the PC at both feeding rates and on Spc., as an inverse relationship appeared between the impact area and mill productivity at the feed rate 1500 g min-1. The area of 720 mm2 surpassed the area 480 and 960 mm2 at the rate of feeding 3000 g min-1, as it recorded 1215.65 g min-1 compared to 950.65 and 882.65 g min-1, respectively. There is effect of feeding rate on PC and Spc. The traditional hammer is recommended for simplicity of design, manufacture and performance at high feed rates compared to the T-shaped hammer.

Multi-cycle of AISI 5135 steel modification by irradiation of the “film (Si (0.2 μm) + Nb (0.2 μm))/(AISI 5135 steel) substrate” system with an intense pulsed electron beam

Steel AISI 5135 surface layer modification carried out by high-cycle high-speed melting of the “film (Si + Nb)/(steel AISI 5135) substrate” system with an intense pulsed electron beam with an impact area of several square centimeters, have been implemented in a single vacuum cycle on the “COMPLEX” setup. The regime of the system “film (Si (0.2 μm) + Nb (0.2 μm))/(steel AISI 5135) substrate” irradiation with an intense pulsed electron beam (20 J/cm2, 200 μs, 3 pulses, 3 cycles) which makes it possible to form a surface layer with high thermal stability have been revealed. This layer is characterized by high hardness, more than 3 times higher than the hardness of AISI 5135 steel in the original (ferrite-pearlite structure) and wear resistance, more than 90 times higher than the wear resistance of the initial AISI 5135 steel. It is shown that the high strength and tribological properties of steel are due to the formation of the hardening phase particles (niobium silicide of Nb5Si3 composition).

Impact Based Forecast analysis uses multi-model ensemble data and National Digital Forecast data in ArcMap 10.8.1

The number of people seeking public weather service information is growing, making it a challenge for all bureaus of meteorology around the world. Although, in the last decade, routine public weather service information has brought excellent weather forecast information for people and services to people with rapid, accurate, widely available, and easy to grasp information, which they may get in a variety of places, such as a website or an application. However, in this decade and in the future, it will not be enough. People want information such as what the impact should be and how people react to that impact, which should be displayed on a static Geographic Information System (GIS) map in a standard format. We will investigate and create an IBF map based on multi-model ensemble data and National Digital Forecast (NDF) data in this work. Then, using the GIS software ArcMap 10.8.1, we rank and score the geographic disaster data to determine the impact area. To create the effect area, we will employ primary and advanced methods of ArcMap 10.8.1. The information on the IBF map will be immediately understood by stakeholders and users.

Properties of debris flow deposits in Masamba, South Sulawesi, Indonesia

On 13 July 2020, a huge landslide-induced debris flow struck Masamba city and its vicinity, providing a massive amount of sedimentation materials. The landslide-induced debris flow was triggered by heavy rainfall, causing damages such as life and property losses, traffic disruption. Landslide-induced debris flow is a sudden natural hazard in mountain regions characterized by fast velocity, huge impact area, large scale, and often causes disastrous accidents. This study aims to investigate the properties of the debris flow materials including the soil size distribution, density, shear strength and bearing capacity. The results showed that the sedimentation material at landslide sites containing a large amount of sand which is classified as a poorly graded sand (SP). The engineering properties such as density, cohesion, internal friction angle and the value California Bearing Ratio (CBR) were also discussed.