43 research outputs found

    Variability of snow cover and frost depth at the Potsdam station, Germany

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    The presented paper examines variability of characteristics of snow cover (snow cover depth, number of days with snow cover and dates of beginning and end of snow cover) and frost depth in Potsdam. The study makes use of a unique long time series of data from the secular meteorological station in Potsdam (Germany), covering the time interval from 1893 to date. The observed behaviour of time series of snow is complex, and not easy to interpret. Even if shrinking snow cover is typically expected in the warming climate of the moderate zone, the change in Potsdam is largely dominated by inter-winter and intra-winter variability, rendering trend detection difficult. Nevertheless, an increasing, statistically significant trend for winter precipitation was detected with almost no changes in the snow fall. A statistical link between the NAO index and the snow cover depth as well as the number of snow cover days was found

    DESIGN OF SMART VERTICAL HYDROPONIC SYSTEM

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    ABSTRACT All horticultural regions of the world have fundamentally developed in the programmatic era through farmer impact and imaginative development practices. The methods described are used to monitor satisfaction and crop yields. Because of the quality of the soil and the nourishment of the land, their cultivation has improved and created more money. The disadvantage is that it took them a long speculation to acquire the crops, and the level of nutrition was not usually put at its obvious level. In addition, many areas were devoted to production, which required a lot of work to treat the whole area. In order to control the time and methods well, the majority of the regions switched to careful development principles with IoT structures. Growing on water is the most progressive strategy to grow natural plants, vegetables and fruits without using land. The use of Rockwool in agricultural strategies where water contamination is possible for a certain period will result in huge yields and the requirement of longer growing times will be waived. Most of the countries that have practiced smart and economic development with little external intervention. IoT sensors are used in the water cultivation development system to test the situation and quality of yields continuously. They will effectively provide information to the whole system when the water or nutrient level has dropped. In the beginning, the development of hydroponics was done horizontally in small spaces in order to maintain the water flow. Today, it is applied on a vertical structure to save space and water flows when needed. With this method, yields are likely to be achieved even more space-efficiently and with little external intervention. Vertical hydroponics performs better than previous conventional approaches; perhaps the farmers in the extension unit have considered the cost of the total layout. This evaluation paper describes the use of procedures and development of automated methods using IoT platforms. Many reference materials can be used big data

    An overview of burst, buckling, durability and corrosion analysis of lightweight FRP composite pipes and their applicability

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    © 2019 Elsevier Ltd. All rights reserved.The main aim of this review article was to address the performance of filament wound fibre reinforced polymer (FRP) composite pipes and their critical properties, such as burst, buckling, durability and corrosion. The importance of process parameters concerning merits and demerits of the manufacturing methods was discussed for the better-quality performance. Burst analysis revealed that the winding angle of ±55° was observed to be optimum with minimum failure mechanisms, such as matrix cracking, whitening, leakage and fracture. The reduction of buckling effect was reported in case of lower hoop stress value in the hoop to axial stress ratio against axial, compression and torsion. A significant improvement in energy absorption was observed in the hybrid composite pipes with the effect of thermal treatment. However, the varying winding angle in FRP pipe fabrication was reported as an influencing factor affecting all the aforementioned properties. Almost 90% of the reviewed studies was done using E-glass/epoxy materials for the composite pipe production. By overcoming associated limitations, such as replacing synthetic materials, designing new material combinations and cost-benefit analysis, the production cost of the lightweight FRP composite pipes can be decreased for the real-time applications.Peer reviewe

    Utilisation des ré-analyses NCEP pour la génération de scénarios météorologiques. Application pour la génération de scénarios de crues pour le RhÎne à l'amont du Léman

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    Generation of meteorological scenarios from NCEP reanalyses. Application for the generation of flood scenarios for the Rhone upstream to Lake Leman. Optimal water resources management requires hydrological scenarios for the climate situation under consideration. These scenarios may be produced from meteorological scenarios thanks to an appropriate hydrological model. The Laboratory «Hydrology and Land Improvement » (HYDRAM) developed a combined downscaling model for the multisite stochastic generation of the meteorological variables required for the generation of such scenarios. The model combines a statistical downscaling model and a k-nearest neighbour resampling approach to generate hourly precipitation and temperature series from NCEP reanalyses. It was applied for the upper Rhone catchment. Observed statistics are well reproduced for both meteorological variables. Then it was used for the generation of a suite of flood scenarios at different hydrological stations of the studied catchment. It can also be applied to downscale climate experiments from global and / or regional climate models for future climate conditions.La gestion optimale de la ressource en eau et des risques hydrologiques associĂ©s nĂ©cessite souvent l’estimation des diffĂ©rents scĂ©narios hydrologiques possibles pour le contexte climatique considĂ©rĂ©. La modĂ©lisation hydrologique permet de produire par simulation de tels scĂ©narios sur la base de scĂ©narios mĂ©tĂ©orologiques obtenus Ă  l’aide d’un gĂ©nĂ©rateur stochastique appropriĂ©. Cette approche a Ă©tĂ© adoptĂ©e par le laboratoire Hydrologie et AmĂ©nagements de l’EPFL (HYDRAM) pour produire, pour la situation climatique actuelle, un catalogue de scĂ©narios de crue en diffĂ©rentes stations hydromĂ©triques du bassin versant du RhĂŽne Ă  l’amont du Leman. Le gĂ©nĂ©rateur stochastique des variables mĂ©tĂ©orologiques utilise comme donnĂ©es d’entrĂ©e les sĂ©ries temporelles de diffĂ©rents indices de circulation gĂ©nĂ©rale extraits des rĂ©analyses NCEP pour la pĂ©riode 1960-2001. Il s’inspire des mĂ©thodes statistique (Antolik, 2000) et analogique (Obled et al., 2002) souvent utilisĂ©es en prĂ©vision mĂ©tĂ©orologique opĂ©rationnelle pour l’adaptation des sorties des modĂšles mĂ©tĂ©orologiques. Il a Ă©tĂ© utilisĂ© pour la gĂ©nĂ©ration multisite de 50 scĂ©narios de 41 ans de tempĂ©ratures et de prĂ©cipitations horaires sur le RhĂŽne. Il permet de reproduire les statistiques moyennes et maximales de ces variables mĂ©tĂ©orologiques Ă  diffĂ©rentes Ă©chelles de temps et d’espace. Le gĂ©nĂ©rateur peut aussi ĂȘtre utilisĂ© pour adapter les sorties des «expĂ©riences climatiques » fournies par les modĂšles climatiques globaux ou rĂ©gionaux.Hingray BenoĂźt, Mezghani Abdelkader. Utilisation des rĂ©-analyses NCEP pour la gĂ©nĂ©ration de scĂ©narios mĂ©tĂ©orologiques. Application pour la gĂ©nĂ©ration de scĂ©narios de crues pour le RhĂŽne Ă  l'amont du LĂ©man. In: Variations climatiques et hydrologie. Le climat, ses variations sĂ©culaires et ses changements pronostiquĂ©s : quel impact sur l'hydrologie (ressources en eau et Ă©vĂšnements rares, Ă©tiages - crues). 29Ăšmes JournĂ©es de l'Hydraulique. CongrĂšs de la SociĂ©tĂ© Hydrotechnique de France. Lyon, 27-28 mars 2007. 2007

    Generation of meteorological scenarios from NCEP reanalyses. Application for the generation of flood scenarios for the Rhone upstream to Lake Leman

    No full text
    Optimal water resources management requires hydrological scenarios for the climate situation under consideration. These scenarios may be produced from meteorological scenarios thanks to an appropriate hydrological model. The Laboratory "Hydrology and Land Improvement" (HYDRAM) developed a combined downscaling model for the multisite stochastic generation of the meteorological variables required for the generation of such scenarios. The model combines a statistical downscaling model and a k-nearest neighbour resampling approach to generate hourly precipitation and temperature series from NCEP reanalyses. It was applied for the upper Rhone catchment. Observed statistics are well reproduced for both meteorological variables. Then it was used for the generation of a suite of flood scenarios at different hydrological stations of the studied catchment. The stochastic generator can also be applied to downscale climate experiments from global and/or regional climate models for future climate conditions
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