Radiação global e difusa diária na região de transição Cerrado-Amazônia brasileira

This study aimed to analyze the seasonal variations in atmospheric transmissivity and solar radiation (global and diffuse) on the horizontal surface in Sinop, Mato Grosso (MT) (11.865°S, 55.485°W, and altitude of 371 m) from 06/02/2011 to 12/31/2014. The values of diffuse radiation were measured using the Melo-Escobedo-Oliveira (MEO) shadow ring, with application of astronomical, geometric, and anisotropic correction factors. The analysis of atmospheric transmissivity was based on the classification of sky cover as cloudy, partly cloudy, partially clear, or clear. The diffuse radiation showed similar behavior to the radiation at the top of the atmosphere, reaching a maximum between October and April (rainy season), while the global radiation displayed higher levels during the dry season (May to September). The average daily global radiation ranged from 22.75±0.61 MJ m−2 d−1 in August to 16.44±1.45 MJ m−2 d−1 in January. In Sinop, cloudy and partly cloudy skies occurred on 45.6% of days and atmospheric transmissivity of global radiation was greater than 55% on 54.6% of days. The variations in diffuse radiation in the region were influenced by cloudiness and the concentration of biomass burning aerosol particles. The diffuse radiation can represent 8.02%–99.12% of the global radiation and 5.33%–29.01% of solar energy incident at the top of the atmosphere.

Comparison of Fracture Delineation Methods in Anteroposterior Pelvic Radiographs

Pelvic fractures are very difficult to detect due to the visual complexity of the pelvic bone. Pelvic fracture occurs less frequently, only when there is a high energy event such as fall from a height or vehicle collision. In elder people and in osteoporosis patients even a low energy incident may cause fracture. The paper includes the comparison of three different fracture detection methods – GLCM and ANN based, Statistical curve fitting and classifier based and finally statistical curve fitting and ANN based method.

RF-Induced Unintended Stimulation for Implantable Medical Devices in MRI

Historically, patients with implantable medical devices have been denied access to magnetic resonance imaging (MRI) due to several potentially hazardous interactions. There has been significant interest in recent years to provide access to MRI to patients with implantable medical devices, as it is the preferred imaging modality for soft tissue imaging. Among the potential hazards of MRI for patients with an active implantable medical device is radio frequency (RF)-induced unintended stimulation. RF energy incident on the device may be rectified by internal active components. Any rectified waveform present at the lead electrodes may stimulate nearby tissue. In order to assess the risk to the patient, device manufacturers use computational human models (CHMs) to quantify the incident RF on the device and perform in vitro testing to determine the likelihood of unintended stimulation. The use of CHMs enables the investigation of millions of scenarios of scan parameters, patient sizes and anatomies, and MR system technologies.

Inferring energy incident on sensors in low-intensity surface fires from remotely sensed radiation and using it to predict tree stem injury

Remotely sensed radiation, attractive for its spatial and temporal coverage, offers a means of inferring energy deposition in fires (e.g. on soils, fuels and tree stems) but coordinated remote and in situ (in-flame) measurements are lacking. We relate remotely sensed measurements of fire radiative energy density (FRED) from nadir (overhead) radiometers on towers and the Wildfire Airborne Sensor Program (WASP) infrared camera on a piloted, fixed-wing aircraft to energy incident on in situ, horizontally oriented, wide-angle total flux sensors positioned ~0.5m above ground level. Measurements were obtained in non-forested herbaceous and shrub-dominated sites and in (forested) longleaf pine (Pinus palustris Miller) savanna. Using log–log scaling to reveal downward bias, incident energy was positively related to FRED from nadir radiometers (R2=0.47) and WASP (R2=0.50). As a demonstration of how this result could be used to describe ecological effects, we predict stem injury for turkey oak (Quercus laevis Walter), a common tree species at our study site, using incident energy inferred from remotely sensed FRED. On average, larger-diameter stems were expected to be killed in the forested than in the non-forested sites. Though the approach appears promising, challenges remain for remote and in situ measurement.

ANALISIS ARC FLASH 6,3 KV PT HOLCIM INDONESIA TBK. BOGOR, JAWA BARAT

<p><em>Protection system is a safety system on electrical equipment in case of interference. One of the electrical hazards is the arc flash. According to IEEE 1584-2002 arc flash is a blast of heat, hot gas, and liquid metal caused by short circuit interference on the equipment. There are 3 cases of arc flash that occurred in PT Holcim Indonesia Tbk. Bogor, West Java. Th</em><em>e aim of this </em><em>research is to find out the amount of arc flash energy in accordance with IEEE 1584-2002 standard, to know </em><em>how much </em><em>the energy, and also</em><em> to</em><em> classify Personal Protective Equipment (PPE) category for the workers according to NFPA 70E-2009 standard. This study was applied to the 5th mill finishing area at PT Holcim Indonesia Tbk. Bogor, West Java. The results showed on the area of the Finish Mill 5 the value of the energy incident is 16.92 cal/cm² on BUS MD-1, 1.39 cal/cm² on BUS RM-1, 1.35 cal/cm² on BUS FN-2, 2.17 cal/cm² on BUS TR-71, 1.41 cal/cm² on BUS TR-72, and 1.34 cal/cm² on BUS TR-73.</em><strong><em> </em></strong></p><p><em>Sistem proteksi merupakan suatu sistem pengaman pada peralatan listrik jika terjadi gangguan. Salah satu bahaya listrik adalah arc flash. Menurut IEEE 1584-2002 arc flash merupakan ledakan panas, gas panas, dan logam cair yang diakibatkan oleh gangguan hubung singkat (short circuit) pada peralatan. Terdapat 3 kasus arc flash yang terjadi di PT Holcim Indonesia Tbk. Bogor, Jawa Barat. Penelitian ini bertujuan untuk mengetahui besar energi arc flash yang sesuai dengan standar IEEE 1584-2002, untuk mengetahui besar energi serta mengklasifikasi kategori Personal Protective Equipment (PPE) bagi pekerja sesuai dengan standar NFPA 70E-2009. Studi ini diterapkan pada area Finish Mill 5 pada PT Holcim Indonesia Tbk. Bogor, Jawa Barat. Hasil penelitian menunjukkan pada area Finish Mill 5 nilai insiden energinya yaitu 16,92 kal/cm² pada BUS MD-1, 1,39 kal/cm² pada BUS RM-1, 1,35 kal/cm² pada BUS FN-2, 2,17 kal/</em><em>cm²</em><em> pada BUS TR-71, 1,41 kal/cm² pada BUS TR-72, dan 1,34 kal/cm² pada BUS TR-73.</em></p>

RESOLUTION IN PHOTOVOLTAIC POTENTIAL COMPUTATION

In this paper, an analysis of the effect of the various types of resolution involved in photovoltaic potential computation is presented. To calculate solar energy incident on a surface, shadow from surrounding buildings has been considered. The incident energy on a surface has been calculated taking the orientation, tilt and position into consideration. Different sky visibility map has been created for direct and diffuse radiation and only the effect of resolution of the factors has been explored here. The following four resolutions are considered: 1. temporal resolution (1, 10, 60 minutes time interval for calculating visibility of sun), 2. object surface resolution (0.01, 0.1, 0.375, 0.75, 1.25, 2.5 and 5 m² as maximum triangle size of a surface to be considered), 3. blocking obstacle resolution (number of triangles from LoD1, LoD2, or LoD3 CityGML building models), and 4. sky resolution (ranging from 150 to 600 sky-patches used to divide the sky-dome). Higher resolutions result in general in more precise estimation of the photovoltaic potential, but also the computation time is increasing, especially as realizes that this computation has to be done for every building with its object surface (both roofs and façades). This paper is the first in depth analysis ever of the effect of resolution and will help to configure the proper settings for effective photovoltaic potential computations.

RESOLUTION IN PHOTOVOLTAIC POTENTIAL COMPUTATION

In this paper, an analysis of the effect of the various types of resolution involved in photovoltaic potential computation is presented. To calculate solar energy incident on a surface, shadow from surrounding buildings has been considered. The incident energy on a surface has been calculated taking the orientation, tilt and position into consideration. Different sky visibility map has been created for direct and diffuse radiation and only the effect of resolution of the factors has been explored here. The following four resolutions are considered: 1. temporal resolution (1, 10, 60 minutes time interval for calculating visibility of sun), 2. object surface resolution (0.01, 0.1, 0.375, 0.75, 1.25, 2.5 and 5 m² as maximum triangle size of a surface to be considered), 3. blocking obstacle resolution (number of triangles from LoD1, LoD2, or LoD3 CityGML building models), and 4. sky resolution (ranging from 150 to 600 sky-patches used to divide the sky-dome). Higher resolutions result in general in more precise estimation of the photovoltaic potential, but also the computation time is increasing, especially as realizes that this computation has to be done for every building with its object surface (both roofs and façades). This paper is the first in depth analysis ever of the effect of resolution and will help to configure the proper settings for effective photovoltaic potential computations