1,340 research outputs found

    Validation of the Martilli's Urban Boundary Layer Scheme with measurements from two mid-latitude European cities

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    International audienceThe Martilli's urban parameterization scheme is improved and implemented in a mesoscale model in order to take into account the typical effects of a real city on the air temperature near the ground and on the surface exchange fluxes. The mesoscale model is run on a single column using atmospheric data and radiation recorded above roof level as forcing. Here, the authors validate the Martilli's urban boundary layer scheme using measurements from two mid-latitude European cities: Basel, Switzerland and Marseilles, France. For Basel, the model performance is evaluated with observations of canyon temperature, surface radiation, and energy balance fluxes obtained during the Basel urban boundary layer experiment (BUBBLE). The results show that the urban parameterization scheme is able to reproduce the generation of the Urban Heat Island (UHI) effect over urban area and represents correctly most of the behavior of the fluxes typical of the city center of Basel, including the large heat uptake by the urban fabric and the positive sensible heat flux at night. For Marseilles, the model performance is evaluated with observations of surface temperature, canyon temperature, surface radiation, and energy balance fluxes collected during the field experiments to constrain models of atmospheric pollution and transport of emissions (ESCOMPTE) and its urban boundary layer (UBL) campaign. At both urban sites, vegetation cover is less than 20%, therefore, particular attention was directed to the ability of the Martilli's urban boundary layer scheme to reproduce the observations for the Marseilles city center, where the urban parameters and the synoptic forcing are totally different from Basel. Evaluation of the model with wall, road, and roof surface temperatures gave good results. The model correctly simulates the net radiation, canyon temperature, and the partitioning between the turbulent and storage heat fluxes

    Validation of Martilli's urban boundary layer scheme with measurements from two mid-latitude European cities

    No full text
    International audienceMartilli's urban parameterization scheme is improved and implemented in a mesoscale model in order to take into account the typical effects of a real city on the air temperature near the ground and on the surface exchange fluxes. The mesoscale model is run on a single column using atmospheric data and radiation recorded above roof level as forcing. Here, the authors validate Martilli's urban boundary layer scheme using measurements from two mid-latitude European cities: Basel, Switzerland and Marseilles, France. For Basel, the model performance is evaluated with observations of canyon temperature, surface radiation, and energy balance fluxes obtained during the Basel urban boundary layer experiment (BUBBLE). The results show that the urban parameterization scheme represents correctly most of the behavior of the fluxes typical of the city center of Basel, including the large heat uptake by the urban fabric and the positive sensible heat flux at night. For Marseilles, the model performance is evaluated with observations of surface temperature, canyon temperature, surface radiation, and energy balance fluxes collected during the field experiments to constrain models of atmospheric pollution and transport of emissions (ESCOMPTE) and its urban boundary layer (UBL) campaign. At both urban sites, vegetation cover is less than 20%, therefore, particular attention was directed to the ability of Martilli's urban boundary layer scheme to reproduce the observations for the Marseilles city center, where the urban parameters and the synoptic forcing are totally different from Basel. Evaluation of the model with wall, road, and roof surface temperatures gave good results. The model correctly simulates the net radiation, canyon temperature, and the partitioning between the turbulent and storage heat fluxes

    Membangun Aplikasi Berbasis Android “Pembelajaran Psikotes” Menggunakan App Inventor

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    Now it is very difficult to get a job, especially in big cities such as Jakarta, Surabaya, Bandung and others. Where in the major cities are very tight competition in getting a job. Besides the difficulty of finding a job is also affected by a series of tests that must be passed to obtain a job. One of the tests is quite difficult to deal with is the psychological test.Psychological test is a test to measure the psychological aspects of the individual. The purpose is to measure the psychological test on a wide range of possible mental ability of people and supporting factors such as achievement, ability, personality, learning style, intelligence, interests and talents. Therefore, psychological company needs to know how the character and ability of emplooye candidates.Through this study, the authors wanted to build an Android-based application that can be used to practice psychological test is "Learning Psychotest". Application Learning Psychotest will have several features including psychological training issues, guide how to do the psycho test, and tips about psychological test. This application is expected later can help users of mobile devices based on android who wants to learn and practice the psychological test. This Psychotest Learning Applications will be made using the App Inventor beta. With App Inventor beta, we can create an android application without using coding

    Investigation of symmetry attribute analysis on the phase measurements of marine controlled-sourceelectromagnetic surveys

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    In this paper we study the potential of symmetry attribute analysis applied to the phase component of electric field observations of marine controlled-source electromagnetic data. The effectiveness of symmetry attribute analysis on the phase component of marine controlled-source electromagnetic data in detecting the boundaries of resistive layer(s), such as hydrocarbon accumulation, is investigated. A comparison between symmetry attribute analysis on the phase and magnitude component of 2.5D synthetic data and a real data set is also discussed. The results presented a clear response indicative of the locations of the subsurface resistors. The phase symmetry attribute analysis proved to be effective for qualitative detection of the lateral extent of embedded resistors

    Exploring the van der Waals Atom-Surface attraction in the nanometric range

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    The van der Waals atom-surface attraction, scaling as C3 z-3 for z the atom-surface distance, is expected to be valid in the distance range 1-1000 nm, covering 8-10 orders of magnitudes in the interaction energy. A Cs vapour nanocell allows us to analyze the spectroscopic modifications induced by the atom-surface attraction on the 6P3/2->6D5/2 transition. The measured C3 value is found to be independent of the thickness in the explored range 40-130 nm, and is in agreement with an elementary theoretical prediction. We also discuss the specific interest of exploring short distances and large interaction energy.Comment: to appear in Europhysics Letter

    Impact of the Business Establishment of PT. Suri Tani Pemuka to the Social Economic of Fishermen Communities in Dolok Pardamean Subdistrict Simalungun Regency North Sumatera Province.

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    This research was conducted on January, 2 to 7, 2015 in the Village Tigaras Dolok Pardamean Subdistrict Simalungun Regency North Sumatera Province. The research objective was to determined the social and economic conditions of fishermen communities before and after the company PT. SURI TANI PEMUKA and the impact on the community and the area around the company establishment. Fisheries sector development PT. SURI TANI PEMUKA as part of process of local development in promoting economic growth has brought changes to the lives of the people. The changes include the impact of the company\u27s development of fisheries towards socio economic and environment in the area of companies especially on the fishermen.The impact of development of company PT. SURI TANI PEMUKA to the social and economic aspects, include livelihoods in fisheries and agriculture sector change to industry and trade. Other impacts to opening job opportunity for local people and migrant communities. Impact on communities in the area can lead to new businesses and increasing population to the area of the company

    Controlled laboratory test for the investigation of LNAPL contamination using a 2.0 GHz ground penetrating radar

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    Groundwater is an important source of fresh water and, consequently, its quality should be properly monitored. Different contaminants can be identified with different types of equipment and/or measurement procedures. Fuel oil contamination forms a "floating" layer over the water table, which has different electrical properties, therefore electromagnetic techniques can be used to image such contaminants. This paper presents a scale-laboratory test where a 2.0 GHz ground penetrating radar (GPR) is used to assess a controlled-fuel oil injection in a shallow sand tank setup. The test examined several scenarios involving different levels of water saturation and fuel oil contamination. The increase of water content produces a reduction of EM wave propagation velocity, moving some fixed/reference targets to higher reflection times. We use simplified relations to obtain approximated dielectric permittivity values, where the inverted results are consistent with those available in the literature for similar scenarios. Rather than suggesting a true quantitative procedure, these observations could be exploited in a qualitative long-term monitoring strategy in common field situations where a contaminant enters a soil matrix and moves through its pore spaces. Finally, the integration of GPR measurements with other monitoring techniques could increase the reliability of the interpretation and the sensitivity to the contaminant concentration

    Selective Reflection Spectroscopy on the UV Third Resonance Line of Cs : Simultaneous Probing of a van der Waals Atom-Surface Interaction Sensitive to Far IR Couplings and of Interatomic Collisions

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    We report on the analysis of FM selective reflection experiments on the 6S1/2->8P3/2 transition of Cs at 388 nm, and on the measurement of the surface van der Waals interaction exerted by a sapphire interface on Cs(8P3/2). Various improvements in the systematic fitting of the experiments have permitted to supersede the major difficulty of a severe overlap of the hyperfine components, originating on the one hand in a relatively small natural structure, and on the other hand on a large pressure broadening imposed by the high atomic density needed for the observation of selective reflection on a weak transition. The strength of the van der Waals surface interaction is evaluated to be 73±\pm10 kHz.μ\mum3. An evaluation of the pressure shift of the transition is also provided as a by-product of the measurement. We finally discuss the significance of an apparent disagreement between the experimental measurement of the surface interaction, and the theoretical value calculated for an electromagnetic vacuum at a null temperature. The possible influence of the thermal excitation of the surface is evoked, because, the dominant contributions to the vW interaction for Cs(8P3/2) lie in the far infrared range.Comment: submitted to Laser Physics - issue in the memory of Herbert Walther
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