Hydrostatic Level Research Articles

Power Transmission Tower Monitoring with Hydrostatic Leveling System: Measurement Refinement and Performance Evaluation

A hydrostatic leveling system (HLS) is an automated high-accuracy measurement technology widely used for vertical displacement monitoring. This paper focuses on evaluating the performance of HLS for monitoring the deformation of a power transmission tower base together with a slope sensor and displacement meter. The monitoring results show that HLS measurements are strongly affected by the environmental temperature. Therefore, to obtain the actual deformation of a monitoring target, the measurements should be further processed to reduce the effect of temperature on the result. To this end, four data processing schemes are proposed, which are based on the frequency of processing (i.e., day by day, monthly, quarterly, or annually). The results demonstrate that the quarterly processing scheme effectively reduces the impact of temperature on deformation measurements and therefore provides the most accurate results among the four schemes considered. Since after correction, the HLS measurements are consistent with the independent monitoring results obtained from the slope sensor and displacement meter, the proposed correction strategy is workable and might be considered for similar monitoring scenarios in future.

On the Inelastic Mechanical Behavior of Granite: Study Based on Quasi-oedometric and Indentation Tests

The inelastic behavior of Bohus granite is investigated based on experimental and numerical results. The yield surface and related dilation angle are determined based on quasi-oedometric tests performed in an earlier work. It is shown how to obtain the yield surface and dilation angle from this test for hydrostatic pressure levels up to 750 MPa. In the constitutive modeling, a Drucker-Prager law is employed together with a variable dilation angle. The constitutive model is first applied to simulate the quasi-oedometric test and the stress and strain fields are obtained. Furthermore, the validation of the model is investigated by simulation of the spherical indentation test. The results are compared with corresponding experimental data and a good agreement is found.

Abnormally high formation pressures in jurassic-cretaceous reservoirs of Arctic regions of Western Siberia

Results of the study of the structure of hydrodynamic fields in Arctic part of the West Siberian sedimentary basin have designated the main region-specific hydrodynamic feature consisting in the phenomenon of abnormally high formation pressures widely spread at depths of 2.8-6.0 km within Jurassic-Cretaceous reservoirs. The two types of natural pressurized water systems which have developed in the region are: 1) elision (geostatic and geodynamic) system most common in the interior regions, and 2) infiltration aquifer system inherent in the external, near edge zones. As the depth increases, two hydrodynamic zones are distinctly distinguished (from top downwards): hydrostatic and enhanced evolving into AHFD (abnormally high formation pressure). Most of the Aptian-Albian-Cenomanian aquifers belong to the first type. Hydrodynamic field stresses tend to increase in the lower lying Neocomian complex where the already elevated formation pressures gradually build up, to the extent of AHFP in the lower horizons. The Jurassic aquifer complexes in the central parts of the Yamal-Kara depression exhibit either enhanced or abnormally high formation pressures, which decline to hydrostatic levels towards the basin periphery. The anomaly coefficients of formation pressure reach the value of 2.2. The established piezo-minima zones extending along major petroleum charge zones, extending along the major hydrocarbon generation zones (Bolshaya Kheta and Kara megasyneclises) associated with the largest areas of petroleum accumulation (Vankor-Suzun, Bovanenkovo, Urengoy, etc.).

2D WPS System for Measuring the Location Changes in Real Time of PAL-XFEL Devices

Several parts that comprise the large scientific equipment should be installed and operated at precise three-dimensional location coordinates X, Y, and Z through survey and alignment to ensure their optimal performance. As time goes by, however, the ground uplifts and subsides, which changes the coordinates of the installed components and leads to alignment errors ΔX, ΔY, and ΔZ. As a result, the system parameters change, and the performance of the large scientific equipment deteriorates accordingly. Measuring the change in the locations of the systems comprising the large scientific equipment in real time would make it possible to predict alignment errors, locate any region with greater changes, realign components in the fast changing region and shorten the time of survey and alignment. For this purpose, a hydrostatic leveling sensor (HLS) with 0.2 μm resolution was installed and is operated in the PAL-XFEL building. In addition, a 2D wire position sensor (WPS) with a 0.1 μm resolution was installed and is operated in the undulator sections where measurements of the two-dimensional changes of the systems (vertical & horizontal) are necessary. This paper is designed to introduce the operating principle of the 2D WPS, the installation and operation of the WPS system, and the way in which the WPS system is utilized in order to ensure beam stability.

Design and development of an electronic level transmitter based on hydrostatic principle

Diaphragm is a pressure transducer which is used as a primary sensing element for hydrostatic liquid level measurement. In industry, it can be used as a local display unit. Diaphragm reading can be transmit to a remote location with the help of secondary transducer which converts the diaphragm displacement into an electrical signal. In this paper, a simple low cost hydrostatic liquid level transmitter has been developed with diaphragm as a primary transducer and Hall sensor as a secondary transducer. The theoretical analysis of the work has been presented in this article. The theoretical equation describes the working principle of the proposed transmitter. The experimental setup has been developed in the laboratory and tested over a range of 0–100 cm. The static characteristic of the hydrostatic level transmitter shows that the transmitter follows the theoretical equation. The experimental results reported in this paper show that the transmitter characteristics are linear and repeatable under permissible uncertainty range.

Proof Load Test on Bridges and Viaducts: A Bibliography Analysis

This article aims at the study of proof load tests on bridges and viaducts, presenting the definitions and methods related to this test, in addition to describing the first load tests ever performed in Brazil. It evaluates the procedures of the Brazilian standards (NBR 9607:2013), comparing with the international regulations. The following topics present the importance and the way in which the load test is carried out, showing the risks of this test. Finally, this article explains the relevance of instrumentation and describes the most commonly used equipment: extensometer, inductive displacement transducer, deflectometer, clinometer, topography instruments, single-cell cell for measuring stationary forces and hydrostatic leveling system with pressure cell.

Basic Principles of Hydrostatic Levelling

Abstract The paper aims to introduce the distribution, history and the basic physical principles hydrostatic levelling. The principle of this method is based on known law of connected vessels filled with fluid. Well known equipment is surface water level, the height of the surface is deducted on millimetre scale. There are currently used devices that allow deducting with accuracy of 0.01 mm.

Lethality Prediction for Escherichia Coli O157:H7 and Uropathogenic E. coli in Ground Chicken Treated with High Pressure Processing and Trans-Cinnamaldehyde.

The study provided an effective means to reduce the high hydrostatic pressure level with incorporation of antimicrobial compound to achieve a 5-log reduction of pathogenic E. coli without damaging the raw meat quality. The developed models may be used to predict the high pressure processing lethality (and process optimization), product development (ingredient selection), and to assist the microbial risk assessment.

Evaluation of the possibility of equalizing the fluid temperature in a hydrolevelling system by mixing

Measurement systems that are based on the hydrostatic leveling method in ideal conditions allow one to control vertical displacements with accuracy of the order of one micrometer. Heterogeneous and time-varying environmental conditions have a significant effect on the measurement error. One way to reduce it is to equalize the temperature of the fluid in a hydrostatic level by mixing liquid inside it before taking measurements. In this paper, it is estimated that this operation can be performed by modeling the fluid circulation process in a simplified analog of the hydrostatic level taking into account a heat transfer through the hose wall. The fluid dynamics is described by the Reynolds averaged Navier-Stokes equations, which are closed by the SST turbulence model. The given analytical estimates of heat transfer coefficients on the side surface of the hose are refined on the basis of experiments at two values of the flow rate of water flowing through the pipe. The evolution of the temperature field is found from the numerical solution of the conjugate heat transfer problem by the finite volume method. In the test example, in which two parts of the hydrostatic level are located in the areas with markedly different temperature, the heterogeneity of the temperature field at different times has been estimated. The mixing time sufficient to achieve a temperature close to the homogeneous distribution of the flowing fluid in the hydrostatic level is determined at different volumes of the mixer. The proposed approach can be used under real external conditions for the selection of optimal parameters of the pump: flow rate, mixing time and mixing tank volume. The temperature field obtained in the calculation can serve as a basis for estimating the achievable accuracy of the measurement system.

Assessment of Fiber Reinforced Concrete Slab and Subsoil Interaction - Experiment

The paper is focused on the interaction of the fibre reinforced concrete slab and the subsoil using both the results of experimental measurements on the experimental stand. Performed experimental measurements include monitoring of the concentrically loaded concrete slab with the dimensions of 2 m x 2 m and thickness of 0.15 m. This slab is in the interaction with subsoil of sandy clay character. The experimental load is applied in sequential steps by using a hydraulic press. During the tests the strain gauges and hydrostatic levelling method were used for the monitoring of the settlements of the slab. The contact stresses and the stresses corresponding to a certain depth below the slab were monitored by using a flat pressure cells. In the conclusion of this paper there are formulated the basic aspects of concrete slab-subsoil interaction, the results of various performed experimental measurements and the comparison of stress below the surface resulted from interaction of soil and slab of different degree of reinforcement.

Wire position system to consistently measure and record the location change of girders following ground changes

Several parts that comprise the large scientific device should be installed and operated at the accurate three-dimensional location coordinates (X, Y, and Z) where they should be subjected to survey and alignment. The location of the aligned parts should not be changed in order to ensure that the electron beam parameters (Energy 10 GeV, Charge 200 pC, and Bunch Length 60 fs, Emittance X/Y 0.481 μm/0.256 μm) of PAL-XFEL (X-ray Free Electron Laser of the Pohang Accelerator Laboratory) remain stable and can be operated without any problems. As time goes by, however, the ground goes through uplift and subsidence, which consequently deforms building floors. The deformation of the ground and buildings changes the location of several devices including magnets and RF accelerator tubes, which eventually leads to alignment errors (∆X, ∆Y, and ∆Z). Once alignment errors occur with regard to these parts, the electron beam deviates from its course and beam parameters change accordingly.PAL-XFEL has installed the Hydrostatic Leveling System (HLS) to measure and record the vertical change of buildings and ground consistently and systematically and the Wire Position System (WPS) to measure the two dimensional changes of girders. This paper is designed to introduce the operating principle and design concept of WPS and discuss the current situation regarding installation and operation.

Development and Experiment of Lifting Platform for Orchards in Hilly Area

At present, pruning of fruit trees on hills is mainly completed by climbing on trees or ladder, which could cause injury due to poor landform. In order to avoid such kind of risks, it is important to develop a lifting platform for orchards in hilly area. In this paper its structure and working mechanism were introduced. This lifting platform, as a machine, is comprised of power device, elevating mechanism, leveling mechanism, slewing mechanism, supporting mechanism and hydraulic control system, and is driven by a small four-wheel tractor. Its hydraulic system can control hydraulic cylinders to extend and retract so as to lift, lower, rotate or keep platform at horizontal position. By analyzing the machine’s kinematic model, the mode of hydrostatic triangle leveling was determined. In order to simplify the machine’s structure, a cantilever beam was used as a supporting mechanism. After carried out the performance test for the machine, the results show that the machine has the following features: stable working performance, the maximum load up to 150 kg, the lifting height 1.5 m, the rotating speed 1 r/min, the lifting velocity 0.1 m/s, and leveling error in lifting process no more than 2° (no matter on horizontal plane or on slopes). So the machine can be suitable for sloped terrain, and the design requirements are well satisfied.

Numerical estimation of various influence factors on a multipoint hydrostatic leveling system

Among various methods that allow controlling quasi-static vertical displacements of structures, the hydrostatic leveling method remains relevant. A multi-point hydrostatic leveling systems allows controlling the vertical displacement field with the required spatial resolution. It is assumed that the liquid level in the each measuring vessel has the same absolute elevation. However, it is influenced by various external factors, which are difficult to eliminate when implementing the method in real constructions. Consequently, it is necessary to assess the influence of these factors and develop methods aimed at their reduction or compensation. A mathematical model, describing the viscous incompressible fluid motion located in a multipoint level with absolutely rigid walls, is presented in the paper. The experiments performed with two point levels of different lengths, as well as analytical estimates of other authors, made it possible to estimate the degree of confidence of the model and the boundaries of applicability. The influence of non-uniform density of a liquid on the liquid level in a 4-point hydrostatic level of different topologies is numerically estimated using the model. An estimation of transient processes in the level, caused by an air pressure surge over one of the measuring vessels is carried out.

Extreme hydrothermal conditions at an active plate-bounding fault.

Temperature and fluid pressure conditions control rock deformation and mineralization on geological faults, and hence the distribution of earthquakes. Typical intraplate continental crust has hydrostatic fluid pressure and a near-surface thermal gradient of 31 ± 15 degrees Celsius per kilometre. At temperatures above 300-450 degrees Celsius, usually found at depths greater than 10-15 kilometres, the intra-crystalline plasticity of quartz and feldspar relieves stress by aseismic creep and earthquakes are infrequent. Hydrothermal conditions control the stability of mineral phases and hence frictional-mechanical processes associated with earthquake rupture cycles, but there are few temperature and fluid pressure data from active plate-bounding faults. Here we report results from a borehole drilled into the upper part of the Alpine Fault, which is late in its cycle of stress accumulation and expected to rupture in a magnitude 8 earthquake in the coming decades. The borehole (depth 893 metres) revealed a pore fluid pressure gradient exceeding 9 ± 1 per cent above hydrostatic levels and an average geothermal gradient of 125 ± 55 degrees Celsius per kilometre within the hanging wall of the fault. These extreme hydrothermal conditions result from rapid fault movement, which transports rock and heat from depth, and topographically driven fluid movement that concentrates heat into valleys. Shear heating may occur within the fault but is not required to explain our observations. Our data and models show that highly anomalous fluid pressure and temperature gradients in the upper part of the seismogenic zone can be created by positive feedbacks between processes of fault slip, rock fracturing and alteration, and landscape development at plate-bounding faults.

Comparative analysis of earthquakes data recorded by the innovative Precision Laser Inclinometer instruments and the classic Hydrostatic Level System

The Hydrostatic Level System (HLS) data and the Precision Laser Inclinometer (PLI) instruments data have been comparatively analyzed in the event of surface angular oscillations induced by earthquakes. The comparative data analysis has shown an agreement on the arrival and stop time of earthquakes. The data have been analyzed within the instruments sensitivity ranges having an overlap in frequency intervals.

The Research of the Suitability of Hydrostatic Water Level Sensor to Measure Storm Water Runoff Flow Rate with the Focus on the Influence of Sediments

Since most of the contaminants in surface waters fall with storm water runoff, it is very important to correctly describe the content of pollutants discharging with them (kilograms or tons) for a given unit of time (hour, shift, day, month or year). Measurements are complicated by the fact that the flow rate and pollutant concentration is very variable over time. The aim of the research was to determine the grain size of sweepings accumulated on the surfaces of the researched territory and to investigate the impact of storm water runoff sediments on the accuracy of measurements of water level height using the hydrostatic water level sensor. For the experiment four typical Vilnius city streets, two storm water runoff treatment plants and also the streets sweeping machine was chosen. Storm water runoff in urban areas has an abundance of sediment, therefore, studying the hydrostatic water level sensor DI 240 Diver suitability to determine storm water runoff flow rate, for the experimental studies the impact of sludge and sand for measuring accuracy was chosen. Particles with diameters ranging from 0.315 to 0.630 mm consisting the maximum weight (the average value of 24 g per 100 g of the sample) of street sweepings. Storm water runoff treatment plants sediments are approximately 60% of the smallest particles with a size of less than 0.05 mm. Particles of less than 0.25 mm consisting about 80% of sediment. During laboratory and full scale tests it was determined, that there is no significant affect of sediments on the accuracy of the hydrostatic water level sensor measurements. The average square error (standard deviation) was 0.567 cm when the measurement uncertainty was 0.0021 cm.

Deformation of multi-storey flat slabs, a site investigation

Traditional reinforced concrete slabs and beams are widely used for building. The use of flat slab structures gives advantages over traditional reinforced concrete building in terms of design flexibility, easier formwork and use of space and shorter building time. Deflection of the slab plays a critical role on the design and service life of building components; however, there is no recent research to explore actual deformation of concrete slab despite various advancements within the design codes and construction technology. This experimental study adopts the Hydrostatic Levelling Cells method for monitoring the deformation of a multi-storey building with flat slabs. In addition, this research presents and discusses the experimental results for the vertical deformation.

Abstract A42: Systematic modulation of the physical microenvironment for characterization of cancer cell lines and primary tissue

Abstract Introduction: The tumor microenvironment includes a range of physical, chemical, and cellular components such as pressure, hypoxia, acidosis, the extracellular matrix (ECM), stromal, and immune cells. These factors can influence the gene and protein expression of the various types of cells that make up the tumor as well as influence the selection of cells that can thrive in that environment; however, typical cancer cell culture rarely uses hypoxia and pressure nor utilizes substrates similar to the native ECM. We designed a system study the influence of hypoxia, pressure, and native ECM conditions on cancer cell lines and primary cells, with the goal of creating a more relevant culture environment for translational studies. Methods: Here, we comprehensively studied how hypoxia, pressure, and ECM composition and organization influences cell biology and gene expression, using transcriptome profiling across a range of physiologically-relevant culturing conditions to mimic various tumor microenvironments found within the body. To do this, we utilized Xcell's primary cell culture platform which includes a custom bioreactor that allows us to control both oxygen concentration (0.1%-20% O2) and hydrostatic pressure levels (26 to 260 mmHg / 0.5 psig to 5 psig). Additionally, we studied the influence of biomimetic substrates by controlling ECM composition and organization (aligned or unaligned collagen at concentrations from 1-2.5 mg/ml +/- fibronectin 0.1-10 microgram/ml) as both 2D ECM coatings and 3D hydrogels. Cell lines studied included models for brain cancer (U-87, A172), pancreatic cancer (PANC10.05), and prostate cancer (DU-145, PC-3, 22Rv1, LNCaP). We performed high-resolution immunofluorescence imaging and western blot protein expression analysis of key targets, including immunotherapy targets CTLA-4, PD-1, and PD-L1. Additionally, we applied our ability to tune culturing conditions to represent physiological conditions in the body for the successful culture of fresh primary tissues from normal volunteers as well as cancer patients for downstream analysis studies focused on biomarker discovery and as a clinical tool for disease monitoring and treatment decision-making. Conclusions: We identified both common and unique gene signatures across these different cells lines, with the hypoxic conditions activating HIF1 pathway activation having common across the cells studied whereas pressure results in more restricted signatures. Some cancer cell lines and PBMCs differentially express immunotherapeutic targets, at low oxygen and high pressure culturing conditions, resulting in reduced expression of key targets. Moreover, biomimetic ECM studies revealed modulation of ECM to represent a “tumor”-like ECM dramatically altered cell growth, morphology, and focal adhesion organization. In a 3D hydrogel context, a “tumor”-like ECM and a hypoxic environment dramatically enhanced tumor cell invasion. Consistently, analysis of mRNA-seq data revealed alterations in gene expression profiles of immunotherapeutic and drug-target pathways involving CTLA-4 and AR signaling as well as EMT targets. In contrast, we observed increased CD47 and CD44 expression at low oxygen and high pressure culturing conditions in cancer cell lines and PBMCs. Thus, supporting the notion that these are possible drug targets for tumors that are characterized by low oxygen levels and high interstitial fluid pressure. Citation Format: Luke Cassereau, Bruce Adams, Tianna Chow, Ajuni Sohota, Charles Ryan, James Lim. Systematic modulation of the physical microenvironment for characterization of cancer cell lines and primary tissue. [abstract]. In: Proceedings of the AACR Special Conference on Engineering and Physical Sciences in Oncology; 2016 Jun 25-28; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2017;77(2 Suppl):Abstract nr A42.

GROUNDWATER RESPONSE TO CHANGES IN PRECIPITATIONS IN NORTH-EASTERN ROMANIA

Changes in the climatic and hydrological variables in North-Eastern Romania indicate that the region has mostly a common evolution in terms of precipitation and hydrostatic level of groundwater. This can influence human communities in the region, given that sources of public water supply are predominantly from underground. In the analysed region with more than 8.000 sqm, 50% of the population lives in the rural area, where the main water supply source is provided by the underground water, mainly from individual wells with depths between 1 and 10 meters (only 10% from the rural population is connected to a centralized water supply system). That means the underground water resources are subject to overexploitation, especially given the prevailing economic activities associated with agriculture and construction involving high water consumption, predominantly from underground. Seasonal and annual data series of precipitation and hydrostatic level over a period of 31 years (1983-2014) and collected in 36 hydrogeological stations (73 wells) and three weather stations have been used. The trends were detected by employing Mann-Kendall test and Sen's slope, and the correlation between the two variables was performed based on Bravais-Pearson correlation. The main results of the paper are: increasing trends are dominant both for annual and seasonal data sets of precipitation, but the great majority of the slopes detected are not statistically significant. In winter, precipitations have a decreasing trend and the slopes are statistically significant. In terms of hydrostatic level, most of the trends detected for near-surface wells are decreasing, while in depth, increasing trends are dominant; the most important change was seen in the deep gap between 200 and 300 cm; correlation between precipitation and hydrostatic level is stronger and more frequent for summer (more than 86% of pairs were found statistically significant) and autumn (more than 80%), and is fable and less frequent for spring and winter due to trans-seasonal distribution of precipitation.

On some problems of measuring systems based on hydrostatic leveling for long-term measurements

On some problems of measuring systems based on hydrostatic leveling for long-term measurements