11 research outputs found

    Automatic Soil Detection Using Sensors

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    Soil fertility is an important factor to measure the quality of the soil as it indicates the extent to which it can support plant life. The fertility of soil is measured by the amount of macro and micronutrients, water, pH etc. The concept of Smart Agriculture is becoming a reality as it evolves from conceptual models for the development of crop at different stages. Previously the agriculture is the cultivation of the plants which is used to sustain and enhance human life. Now the Smart Agriculture has come into the picture globally. Smart Agriculture is nothing but the usage of the resources in a smarter way. Resources include sustainable land usage, fresh water usage, and usage of pesticides and insecticides which increases the crop production and supports the farmers� income. Firstly the developed Sensor kit will be checking the Soil type and Soil Quality. Later the different tests are performed on soil such as bulk density test, respiration test, moisture test and it also needs to check the water quality. By considering the results obtained by the above tests the device suggests the crop for the farmer and it also helps him for the maintenance of the crop. To keep the services of Smart Agriculture the IOT plays a key role

    Post-blast explosive residue : a review of formation and dispersion theories and experimental research

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    The presence of undetonated explosive residues following high order detonations is not uncommon, however the mechanism of their formation, or survival, is unknown. The existence of these residues impacts on various scenarios, for example their detection at a bomb scene allows for the identification of the explosive charge used, whilst their persistence during industrial explosions can affect the safety and environmental remediation efforts at these sites. This review article outlines the theoretical constructs regarding the formation of explosive residues during detonation and their subsequent dispersal and deposition in the surrounding media. This includes the chemical and physical aspects of detonation and how they could allow for undetonated particles to remain. The experimental and computational research conducted to date is discussed and compared to the theory in order to provide a holistic review of the phenomeno

    A study of dispersion and combustion of particle clouds in post-detonation flows

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    Augmentation of the impact of an explosive is routinely achieved by packing metal particles in the explosive charge. When detonated, the particles in the charge are ejected and dispersed. The ejecta influences the post-detonation combustion processes that bolster the blast wave and determines the total impact of the explosive. Thus, it is vital to understand the dispersal and the combustion of the particles in the post-detonation flow, and numerical simulations have been indispensable in developing important insights. Because of the accuracy of Eulerian-Lagrangian (EL) methods in capturing the particle interaction with the post-detonation mixing zone, EL methods have been preferred over Eulerian-Eulerian (EE) methods. However, in most cases, the number of particles in the flow renders simulations using an EL method unfeasible. To overcome this problem, a combined EE-EL approach is developed by coupling a massively parallel EL approach with an EE approach for granular flows. The overall simulation strategy is employed to simulate the interaction of ambient particle clouds with homogenous explosions and the dispersal of particles after detonation of heterogeneous explosives. Explosives packed with aluminum particles are also considered and the aluminum particle combustion in the post-detonation flow is simulated. The effect of particles, both reactive and inert, on the combustion processes is analyzed. The challenging task of solving for clouds of micron and sub-micron particles in complex post-detonation flows is successfully addressed in this thesis.Ph.D

    The transfer of unsterilized material from Mars to Phobos: laboratory tests, modelling and statistical evaluation

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    Sample return missions to Phobos are the subject of future exploration plans. Given the proximity of Phobos to Mars, Mars’ potential to have supported life, and the possibility of material transfer from Mars to Phobos, careful consideration of planetary protection is required. If life exists, or ever existed, on Mars, there is a possibility that material carrying organisms could be present on Phobos and be collected by a sample return mission such as the Japanese Martian Moons eXplorer (MMX). Here we describe laboratory experiments, theoretical modelling and statistical analysis undertaken to quantify whether the likelihood of of a sample from Phobos material containing unsterilized material transferred from Mars is less than 10-6, the threshold to transition between restricted and unrestricted sample return classification for planetary protection. We have created heat, impact and radiation sterilisation models based on the Phobos environment, and through statistical analyses investigated the level of sterilisation expected for martian material transferred to Phobos. These analyses indicate that radiation is the major sterilisation factor, sterilising the Phobos surface over timescales of millions of years. The specific events of most relevance in the Phobos sample return context are the ‘young’ cratering events on Mars that result in Zunil-sized craters, which can emplace a large mass of martian material on Phobos, in a short period of time, thus inhibiting the effects of radiation sterilisation. Major unknowns that cannot yet be constrained accurately enough are found to drive the results – the most critical being the determination of exact crater ages to statistical certainty, and the initial biological loading on Mars prior to transfer. We find that, when taking a conservative perspective and assuming the best-case scenario for organism survival, for a 100 g sample of the Phobos regolith to be below the planetary protection requirement for unrestricted sample return, the initial biological loading on Mars must be 3cfu kg-1. For the planned MMX mission, a ∼10 g sample to be obtained from a 25-30 mm diameter core as planned would require an initial martian biological loading to be 4cfu kg-1, in order to remain compliant with the planetary protection threshold

    Pre-exascale accelerated application development:The ORNL Summit experience

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    High-performance computing (HPC) increasingly relies on heterogeneous architectures to achieve higher performance. In the Oak Ridge Leadership Facility (OLCF), Oak Ridge, TN, USA, this trend continues as its latest supercomputer, Summit, entered production in early 2019. The combination of IBM POWER9 CPU and NVIDIA V100 GPU, along with a fast NVLink2 interconnect and other latest technologies, pushes system performance to a new height and breaks the exascale barrier by certain measures. Due to Summit's powerful GPUs and much higher GPU-CPU ratio, offloading to accelerators becomes a requirement for any application, which intends to effectively use the system. To facilitate navigating a complex landscape of competing heterogeneous architectures, a collection of applications from a wide spectrum of scientific domains is selected for early adoption on Summit. In this article, the experience and lessons learned are summarized, in the hope of providing useful guidance to address new programming challenges, such as scalability, performance portability, and software maintainability, for future application development efforts on heterogeneous HPC systems
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