Results Of Field Measurements Research Articles

Evaluation of Natural Lighting System of Lecture Building

Visual comfort is one of the most important things that building need. A building with a proper passive design obtains fulfill the users visual comfort through natural lighting  on the other hand, a passive design that is less precise always requires energy to achieve the users visual comfort. Lecture building is one of the buildings that is effectively used 8 hours a day and 5 days on a week. The high operating hours cause visual comfort in the building becomes very important. The purpose of this study is to determine the performance of the building passive design in terms of lighting to comprehend various visual problems in the building. The method used in this research is quantitative comparative by comparing the value of  building lighting. Through the results of field measurements, building modeling simulations with Ecotect software, and SNI 03-6197-2000 parameter  several problems were found in the building's natural lighting system such as inadequacy of lighting on the facade with a southwest orientation, enormous lighting on the facade with a northeast orientation, uneven lighting causing various visual discomforts.

Simulation Validation for Thermal Performance of Building Envelope Material in Humid Tropical Higland Climate

Modeling and simulation using computer software are very important in supporting various types of research based on data calculations. In the research process, accuracy is needed between the simulation results and the results of field measurements. Thus, there is no significant difference between the two results. This study aims to verify and validate the result of field measurements and simulation using the ARCHIPAK 5.1 software. The variables studied focus on indoor air temperature and humidity. This research takes a case study in the village of Ranupane which is located within the Bromo Tengger Semeru National Park. There are 4 housing buildings measured which consist of two types of houses using fireplaces and two types of houses without fireplaces. All of the four houses are afterward modeled using the ARCHIPAK 5.1 software to validate the data results. From the measurement results, the field measurement data show a higher hourly temperature profile compared to the results of the simulation of the base case model. Two striking differences are the type of house without a fireplace which is showing the difference in the average temperature of 1-2 K. While the type of house using fireplace shows the difference average temperature of 5,2-5,3 K. This occurs due to the internal heat gain input which the value is a slight difference between the result of field measurements and simulation of the base case model. This data verification and validation will be used as modeling optimal building configuration for housing in a humid tropical highland climate.

Simulation and experimental study of short-period strong magnetic field undulator

Further reducing the period length will be a very attractive direction for the future development of undulators, and it is one of the effective ways to realize the miniaturization of free-electron laser facilities and obtain short wavelengths. In this paper, a novel planar hybrid permanent magnet undulator is proposed which can obtain a higher peak field with a short period length. The dimensions of the magnet blocks and the poles are numerically optimized for a sample undulator with a period length of 16 mm and a gap of 5 mm. Compared to the conventional hybrid undulator, the effective peak field can be enhanced by about 48%. An eight-period model is built and the result of the magnetic field measurement by a pulsed wire system shows a good consistent with the simulation result.

Influence of cap beam restraint condition on the lateral deformation behavior of large-scale bored piles

The restrained force at the pile cap plays an important role in assessing the stability of bored piles. The constraining force of the cap beam is difficult to calculate due to spatial variability in soil properties, nonlinear soil behavior, and measurement errors. Based on theoretical analysis and field measurements this study proposes an analytical model combining Bayesian theorem and Markov Chain Monte Carlo Simulations (MCMCS) to quantify the restrained force of a pile cap beam. A simplified mechanical model of the constrained effect of the cap beam is established and verified by the results of field measurements. Based on a field excavated slope project, a Bayesian updating modeling approach is established by combing prior information, empirical knowledge, field instrumentation results, and site investigations to calculate the constrained effects of the cap beam. To verify its effectiveness, the model is combined with a finite element model, taking into account the uncertainties of soil moduli and measurement errors. The modeling takes into account the spatial variability and strain dependence of Young’s modulus. By comparisons, it can be found that the predicted displacements of the support pile are in good agreement with the field measurements. The results show that a Bayesian back updating approach can reduce the impact of uncertainty that can guide geotechnical engineering design and construction of similar projects.

R wave identification of blasting seismic waves in propagation process and its engineering application

The identification of R wave is helpful to analyze damage characteristics and damage analysis of nearby building caused by blasting seismic waves. According to the characteristics of low frequency, low speed and strong amplitude of R wave, a time-frequency filter for R-wave recognition is constructed and a R-wave recognition method based on S-transform is proposed. Firstly, the measured blasting vibration signal is transformed from time-space to time-frequency domain by S-transform. Secondly, according to the characteristics of R-wave, the R-wave filter is constructed and processed in time-frequency domain. Finally, the obtained R-wave signal in time-frequency domain is transformed into time-space signal by inverse transform. The results of numerical simulation and field measurement show that the R-wave identification method based on S-transform can effectively suppress and extract R-wave without destroying low-frequency body wave signal.

Goaf and Slope Stability: A Case Study on the Yangla Copper Mine

Considering the wide distribution range of deposits, the complicated geological conditions, and the potential detriment to slope stability during the caving period, underground goaf and slope stability is a critical concern in the Yangla copper mine. In this paper, goaf and slope stability is studied by implementing empirical analysis and numerical simulations with an equivalent continuum model. An overall understanding of underground goaf stability is obtained by the Laubscher graph method, and an approach composed of the geological modeling technology GoCAD and the specialized meshing tool Griddle is proposed to manage the geological database and prepare the numerical model for stability analysis with FLAC 3D . The Hoek–Brown constitutive model is introduced to simulate the complicated mechanical behavior of rock mass in the process of mining, i.e., the brittleness and confinement effect of rock mass. The key orebodies KT2 and KT5 develop in reverse inclination from slope surface to the inner slope with a maximum depth of 900 m, which means the rock mass bears a high stress induced by mining. The mechanical parameters are calibrated carefully by performing mining simulations that are consistent with the field instability phenomenon and measurement results. In particular, rock-mass behavior is predicted by sensitivity modeling in consideration of the goaf span, mining sequence, and material filling, the aim of which is to optimize the mining design to maintain slope stability during the third mining phase. The calculation results indicate that large deformations at the roof of the goaf and pillar are a critical problem in the Yangla copper mine as they are detrimental to slope stability. Moreover, many goafs collapse during the second and third phases of underground mining, which is also detrimental to slope stability, and the span of the goaf with a deep buried depth needs to be adjusted from 36 to 24 m in the third mining phase. The slope is stable in the second mining phase, but, in the third phase, it enters the large-scale instability state due to the destruction of the rock-mass structure near the slope surface by underground caving. Accordingly, goafs with the potential for collapse should be filled with high-strength materials to maintain slope stability.

Application of Empirical Bathymetry Method on Sentinel 2A for Measuring Water Depth of Maninjau Lake

Lake Maninjau is a lake formed by volcanic activity. Many human activities occur on the catchment area, but also in exploited waters. This study aims to mapping the depth of the waters in the Lake Maninjau and assess the effect of field sample distribution on the quality results of the image transformation. The data used are satellite imagery Sentinel 2A, results of point survey. The analysis technique uses the normalized difference water index algorithm, sun glint, empirical bathymetry method and linear regression. The result of the research which is has found that variations of distribution into the dispersion of the recording process of the depth of the object represented by cell. The depth of the water from the results of this transformation refers to the measurement sample in the field survey. The maximum depth of the waters is in the range of 107m. Shallow waters are predominantly distributed in the northern region which is the out late of Lake Maninjau. The southern area forms a deep basin. The distribution of this sample is in the form of an empirical bathymetry map and the relationship between the results of field measurements and the transformation with a regression value of 0.769, this indicates the consideration of total and distribution of survey sample is influence on quality of the results of the transformation.

2D MHD simulation of spontaneous magnetic fields generated during interaction of 1315.2-nm laser radiation with copper slabs at 1016 W/cm2

Multidimensional modeling of phenomena and processes occurring during the expansion of the laser-produced plasma for different irradiation conditions related to both the laser beam parameters and the target constructions is a very complex issue, especially when modeling requires consideration of kinetic processes associated with the development of various types of microscopic instability. Multidimensional PIC codes create such a possibility, but their use is limited to modeling phenomena even in a very narrow timescale due to the limited computational capabilities of current supercomputers. For this reason, the paper attempts to interpret the results of the spontaneous magnetic field (SMF) measurements obtained during the PALS (Prague Asterix Laser System) experiment [Pisarczyk et al., AIP Adv. 10, 115201 (2020); Pisarczyk et al., Phys. Plasmas 22, 102706 (2015)] based on the 2D magneto-hydrodynamic (MHD) model [Jach et al., Computer Modeling of Dynamic Interaction of Bodies by Free Point Method (PWN, Warsaw, 2011)]. The MHD equations were used with included arbitrary (i) current of hot electrons treating it as an additional external current and (ii) ion-sound instability responsible for the increase in anomalous resistance in areas with high temperature and low-density plasma. The spatial distribution of magnetic fields and current density obtained from 2D modeling are in acceptable agreement with the experimental results [Pisarczyk et al., Plasma Phys. Controlled Fusion 62, 115020 (2020); Zaraś-Szydłowska et al., AIP Adv. 10, 115201 (2020); Pisarczyk et al., Phys. Plasmas 22, 102706 (2015)]. The inclusion of temporal changes in anomalous resistance in modeling allowed us to explain the persistence of high SMF amplitude at the level of several megagauss after the laser pulse ended due to the effect of magnetic field freezing.

Incipient flow velocity of non-uniform sediment particles by considering the additional mass force

The sediments on the natural seabed are generally non-uniform particles. The incipient motion of non-uniform sediment particles has always been a key problem in the ocean engineering. In this paper, the incipient flow velocity of non-uniform sediment particles by considering the additional mass force is studied by means of mechanical analysis and comparative verification. Firstly, the mechanical model of non-uniform sediment particles is established in consideration of the seepage force, cohesion and the additional mass force caused by non-uniformity. Combined with the randomness of the position of non-uniform particles on the bed surface and the relative exposure degree of non-uniform particles, a systematic and comprehensive formula of the additional mass force is proposed. The mechanical equilibrium equations of critical incipient motion of the non-uniform sediment particles are established, and the critical incipient flow velocity of sediment particles under sliding instability and rolling instability are derived. Then, the accuracy and validity of the proposed formulas are verified by comparison with the results of flume test, field measurement and other formulas. Finally, the influence factors of the incipient flow velocity of non-uniform sediment particles are analyzed, and the change laws of influence factors are obtained. The results show that: 1) The incipient motion form of sediments on the natural seabed is generally the rolling instability. 2) The incipient flow velocity of sediment particles decreases first and then increases with particle diameter. 3) The incipient flow velocity of sediment particles increases with the dry bulk density. 4) The incipient flow velocity of sediment particles decreases with the increase of hydraulic gradient and relative exposure degree.

Novel Bilayer Micropyramid Structure Photonic Nanojet for Enhancing a Focused Optical Field.

In this paper, synthetically using refraction, diffraction, and interference effects to achieve free manipulation of the focused optical field, we firstly present a photonic nanojet (PNJ) generated by a micropyramid, which is combined with multilayer thin films. The theory of total internal reflection (TIR) was creatively used to design the base angle of the micropyramid, and the size parameters and material properties of the microstructure were deduced via the expected optical field distribution. The as-designed bilayer micropyramid array was fabricated by using the single-point diamond turning (SPDT) technique, nanoimprint lithography (NIL), and proportional inductively coupled plasma (ICP) etching. After the investigation, the results of optical field measurement were highly consistent with those of the numerical simulation, and they were both within the theoretical calculation range. The bilayer micropyramid array PNJ enhanced the interference effect of incident and scattered fields; thus, the intensity of the focused light field reached 33.8-times that of the initial light, and the range of the focused light field was extended to 10.08. Moreover, the full width at half maximum (FWHM) of the focal spot achieved was 0.6, which was close to the diffraction limit.

Modulation of Wind-Wave Breaking by Long Surface Waves

This paper reports the results of field measurements of wave breaking modulations by dominant surface waves, taken from the Black Sea research platform at wind speeds ranging from 10 to 20 m/s. Wave breaking events were detected by video recordings of the sea surface synchronized and collocated with the wave gauge measurements. As observed, the main contribution to the fraction of the sea surface covered by whitecaps comes from the breaking of short gravity waves, with phase velocities exceeding 1.25 m/s. Averaging of the wave breaking over the same phases of the dominant long surface waves (LWs, with wavelengths in the range from 32 to 69 m) revealed strong modulation of whitecaps. Wave breaking occurs mainly on the crests of LWs and disappears in their troughs. Data analysis in terms of the modulation transfer function (MTF) shows that the magnitude of the MTF is about 20, it is weakly wind-dependent, and the maximum of whitecapping is windward-shifted from the LW-crest by 15 deg. A simple model of whitecaps modulations by the long waves is suggested. This model is in quantitative agreement with the measurements and correctly reproduces the modulations’ magnitude, phase, and non-sinusoidal shape.

Underwater Holographic Sensor for Plankton Studies In Situ including Accompanying Measurements.

The paper presents an underwater holographic sensor to study marine particles—a miniDHC digital holographic camera, which may be used as part of a hydrobiological probe for accompanying (background) measurements. The results of field measurements of plankton are given and interpreted, their verification is performed. Errors of measurements and classification of plankton particles are estimated. MiniDHC allows measurement of the following set of background data, which is confirmed by field tests: plankton concentration, average size and size dispersion of individuals, particle size distribution, including on major taxa, as well as water turbidity and suspension statistics. Version of constructing measuring systems based on modern carriers of operational oceanography for the purpose of ecological diagnostics of the world ocean using autochthonous plankton are discussed. The results of field measurements of plankton using miniDHC as part of a hydrobiological probe are presented and interpreted, and their verification is carried out. The results of comparing the data on the concentration of individual taxa obtained using miniDHC with the data obtained by the traditional method using plankton catching with a net showed a difference of no more than 23%. The article also contains recommendations for expanding the potential of miniDHC, its purpose indicators, and improving metrological characteristics.

Development of a high precision small aperture quadrupole magnet with copper plate coils

Using the conventional coil manufacturing method, the iron core of a small aperture quadrupole magnet needs to be divided into four or more segments to install the excitation coils, which brings assembly errors and generates high-order magnetic field harmonics. In this paper, the development of a high-precision small-aperture quadrupole magnet named HQ22 using copper plate coils is described. The magnet has a bore aperture of 22 mm, a gradient of 90 T/m, and an effective length of 0.36 m. Its coil is mainly composed of a number of U-shaped copper plates, electrical connection sheets, and insulating sheets, which are directly assembled and connected on the pole. Outside the coil, water box with cooling water channel inside is installed to provide indirect cooling to the coil. Using copper plate coil, one-piece or two-piece structure can be adopted for the iron core, so the assembly error is reduced and magnetic field quality can be improved. The research provides an attractive technical scheme for small aperture quadrupole magnets in future light sources. The detailed magnet design, magnetic field calculation and measurement results of HQ22 are presented, and the application prospect of copper plate coil is discussed.

Site Measurements and Calculations of Electrostatic and Electromagnetic Fields of a 220-KV Overhead Transmission Line.(Dept.E)

Field measurements, whenever possible, still constitute the most direct method of obtaining quantitative as well as qualitative results concerning the values of both electrostatic and electromagnetic fields, provided adequate arrangements are used. It is also the usual practice to compare the results obtained by measurements with those obtained by calculations, The paper presents the results of electrostatic and electromagnetic field measurements produced under a 220-kV overhead transmission line. Two different sites along the line are selected for field tests, Simp lified measuring technique is used and the measurements are p erformed at different heights ranging from 1 m to 3 m above ground surface, with transverse distances up to 25 m around the centre of the transmission line. Using image theory and the quasi-static app roximation, corresponding results are calculated and compared with the test results. The comparison shows that the results obtained by field tests are in good agreement with those obtained by calculations. This concludes the adequacy of the simp lified measuring technique used in this investigation.

STUDY ON AXIAL FORCE TRANSFER FROM CFT COLUMN TO PILE OF HIGH-RISE BUILDING BY FIELD MEASUREMENT AND FEM ANALYSIS

Axial force of CFT column and steel column embedded into cast-in-place concrete pile were measured in top-down construction method. In addition, measurement results were accurately simulated by FEM analysis. Axial force transfer mechanism from CFT column to pile is analyzed according to field measurement and FEM analysis results. At the pile head, axial force of concrete transferred from steel column is increasing and becomes stable due to slipping between steel column and concrete. Besides, it was found that shear strength of stud connectors at the pile head are 60% of design shear strength.

Scanning laser wave recorder with registration of “instantaneous” sea surface profiles

AbstractA direct optical method for measuring the “instantaneous” profile of the sea surface with an accuracy of 1 mm and a spatial resolution of 3 mm is described. Surface profile measurements can be carried out on spatial scales from units of millimeters to units of meters with an averaging time of 10−4 s. The method is based on the synchronization of the beginning of scanning a laser beam over the sea surface and the beginning of recording the radiation scattered on the surface onto the video camera matrix. The heights of all points of the profile are brought to a single point in time, which makes it possible to obtain “instantaneous” profiles of the sea surface with the frequency of video recording. The measurement technique and data processing algorithm are described. The errors of the method are substantiated. The results of field measurements of the parameters of sea waves are presented: amplitude spectra, distribution of slopes at various spatial averaging scales. The applied version of the wave recorder did not allow recording capillary oscillations, but with some modernization it will be possible. The method is completely remote, does not distort the properties of the surface, is not affected by wind, waves and sea currents, it allows you to measure the proportion of foam on the surface. The possibility of applying the proposed method at any time of the day and in a wide range of weather conditions has been experimentally proved.

Energy efficiency assessment of electric shovel operating in opencast mine

Electric shovels are used for loading in opencast mines. Energy efficiency assessment of electric shovel is important to minimise its electrical energy usage. Specific power consumption (SPC) has been used as performance indicator to assess energy efficiency of shovel. A modelling framework is developed for estimating SPC of electric shovel from operating time and power measured for each process. The model is illustrated with a case study of 42 cu. m. P & H shovel operating in a large opencast mine of India. The SPC of shovel is optimized for actual operating cycle time components (idle time and digging time). Results of field measurements show that digging operation consumes maximum power in comparison to other operations of electric shovel in a cycle. The model has been used to assess the energy saving potential of electric shovel by using the real time operational data. The minimum SPC of electric shovel is 0.12 kWh/cum for zero idle time and the energy saving potential is 13.45%. The optimization of SPC has also been done for different digging conditions. The model developed can help to set a target for energy consumption of electric shovel operating in a mine.

Mechanism of steel pipe reinforcement grouting based on tunnel field measurement results

Mechanism of steel pipe reinforcement grouting based on tunnel field measurement results

ЧИСЛЕННОЕ ИМИТАЦИОННОЕ МОДЕЛИРОВАНИЕ РАСПРОСТРАНЕНИЯ ТЕМПЕРАТУРЫ ПРИ САМОНАГРЕВАНИИ УГЛЯ В ВЫРАБОТАННОМ ПРОСТРАНСТВЕ

Researches of thermodynamic processes of oxidation, self-heating and self-ignition of coal are necessary for studying of dependence of terminal parameters on a set of the influencing factors. In practice of coal mining by the underground method cases of coal self-ignition in the mined-out spaces of production units (lavas) are frequent. In this case one of the tasks consists in determination of temperature in arbitrary point of the nubbly-porous medium of the mined-out space. Need of the solution of this difficult task is caused by the probability of emergency situations in places with the explosive concentration of methane. It is possible that for each seam and grade of coal it is necessary to develop, substantiate and accept an individual indicator for assessing the state of fire hazard. It is proposed to systematize and methodically process the results of field measurements and observations on the analyzed and investigated cases of endogenous fires in problem areas of mines in order to create basin databases for subse- quent operational decisions in emergency situations.

Empirical numerical model of tornadic flow fields and load effects

Tornadoes are the most devastating meteorological natural hazards. Many empirical and theoretical numerical models of tornado vortex have been proposed, because it is difficult to carry out direct measurements of tornado velocity components. However, most of existing numerical models fail to explain the physical structure of tornado vortices. The present paper proposes a new empirical numerical model for a tornado vortex, and its load effects on a low-rise and a tall building are calculated and compared with those for existing numerical models. The velocity components of the proposed model show clear variations with radius and height, showing good agreement with the results of field measurements, wind tunnel experiments and computational fluid dynamics. Normal stresses in the columns of a low-rise building obtained from the proposed model show intermediate values when compared with those obtained from existing numerical models. Local forces on a tall building show clear variation with height and the largest local forces show similar values to most existing numerical models. Local forces increase with increasing turbulence intensity and are found to depend mainly on reference velocity Uref and moving velocity Umov. However, they collapse to one curve for the same normalized velocity Uref / Umov. The effects of reference radius and reference height are found to be small. Resultant fluctuating force of generalized forces obtained from the modified Rankine model is considered to be larger than those obtained from the proposed model. Fluctuating force increases as the integral length scale increases for the modified Rankine model, while they remain almost constant regardless of the integral length scale for the proposed model.