Field Test Results Research Articles

A Multi-Segment Expanded Anchor for Landslide Emergency Management

Conventional mortar cemented anchors cannot meet the needs for landslide emergency management, as they can withstand loads only after mortar curing for 14–28 days. This study developed a multi-segment expanded anchor (MSEA) that expands using a sliding mechanism and rapidly bears loads using multiple load-bearing bodies by the frictional drag along the perforated wall, and the reaction force of the underreams’ platforms. Field tensile tests without grouting and the secondary tensile tests of six MSEAs, each with a length of 23 m, were carried out. The field tests show that the installed load-bearing bodies expanded steadily when the MSEAs were tensioned without grouting. In hard sandstones, the initial tensile force of each load-bearing body exceeded its design value of 150 kN, and the initial bearing capacity of each MSEA was greater than 300 kN, which exceeded the bearing capacity of the existing anchors regardless of grouting. The secondary tensile tests of the MSEAs were conducted after they were grouted for three days, and their lock-off load was greater than their design value of 600 kN. Based on the elastic mechanics and the stress process of the MSEAs, this study derived the theoretical equations of the ultimate bearing capacity of the MSEAs without grouting. The results calculated using the theoretical equations were roughly consistent with the field test results of the ultimate bearing capacity.

Recent Development and Field Test of CO-OPS' Real-Time, Shallow Water CURrents BuoY (CURBY)

Abstract The National Oceanic and Atmospheric Administration (NOAA) National Ocean Service Center for Operational Oceanographic Products and Services (CO-OPS) manages the National Current Observation Program (NCOP) and Physical Oceanographic Real-Time Systems (PORTS®). These programs provide tide and current predictions, as well as real-time current and meteorological information. Outdated current predictions, navigational support requirements, and incident response scenarios (e.g., oil spills, vessel accidents) have highlighted CO-OPS' need for a rapidly deployable system that provides near-surface current and meteorological observations. To address this, CO-OPS designed, developed, and tested a real-time system based on a surface buoy platform, hereinafter referred as CURrents BuoY (CURBY). This paper provides an overview of the system design, field test results, operational applications, and future plans.In 2018, CO-OPS completed the build, integration, and testing of the first prototype CURBY. A successful field test was completed during 2018 in the Chesapeake Bay, and the first operational deployment followed shortly on the Delaware River in 2019. Resulting measurements were used to improve tidal current predictions and to plan for a 2021 regional survey. Initial success with tidal current survey operations led to design enhancement and wider use. During 2020‐2021, CO-OPS partnered with the NOAA Office of Response and Restoration to build two new CURBYs to support emergency response applications in the Gulf of Mexico region. During 2022, two CURBY systems were deployed in the Columbia River, Oregon, to support additional NCOP operations. Future plans include establishing a long-term CURBY system for Kings Bay, Georgia, PORTS®.

One-Dimension Finite Element Modeling of Grouted Ground Anchor

In the present research work, a one-dimension finite element model has been developed to simulate both compression and tension types of grouted ground anchors. The steel tendon-grout interface has been modeled by using the local bond-slip model, while the soil-grout interface has been modeled with a series of perfectly elastic plastic springs. The verification of the proposed one-dimension finite element model has been made by comparison of the model results with a three-dimension finite element model developed by commercial finite element software PLAXIS, and with the results of field tests of tension-type grouted ground anchor. A parametric study has been made to study the load-transfer mechanism for both types of anchors, compression, and tension. The compression-type anchor exhibits less displacement than the tension one under the same applied load. The developed strain in the grouted body of the compression-type anchor is much smaller than the tension-type one, regardless of the type of strain.

Numerical Analysis of Thermal Impact between the Cooling Facility and the Ground

The article presents the results of research on the range of the impact of a cooling facility on the surrounding ground. An analysis of the heat exchange with the ground and through the building partitions was carried out. The analysis was carried out on the basis of the results of actual field tests carried out throughout the measurement year. The object of the research was an agricultural cold store located in southern Poland. The computational analysis of the interaction between the cooling facility and the ground was based on the numerical elementary balances method. The validation of the calculation model was performed based on the adopted boundary conditions. Calculations for the analyzed variants were carried out on the basis of a geometric model of the cooling facility built in the WUFI®plus program, corresponding to the actual dimensions. The analysis of the energy balance of the studied facility showed that the share of energy flow through the floor to the ground constitutes 8.2% of all energy flows through other partitions and the ventilation system. In order to maintain the set air temperature inside the studied building, intensive cooling was required with an energy demand of 5184.5 kWh/year. The results of the research showed that the range of the thermal impact of the building changes depending on the location of the studied ground area in terms of cardinal direction. The external and internal microclimate characteristics also affect the extent of the impact of the cooling facility on the surrounding ground. Under the assumption of stable values of Θi within a range of 0.0–4.0 °C, the largest range of influence (4.0 m) occurs in the summer.

Design and development of agricultural spraying system

The majority of the sprayer pumps available in the current market are back-mounted, hand pumps that are used to spray pesticides. Although tractor-mounted sprayers are presently available on market are seen to use 10 sets of nozzles to spray the pesticide is very demanding on pesticide consumption leading to pesticide wastage, and subsequent soil and water pollution. This paper focused on the development of an agriculture sprayer with an appropriate pesticide application mechanism that would apply the pesticide directly to the plant foliage, and fruits with minimal wastage thereby making effective pest control and so also reducing pesticide consumption which will aid to reduce spraying cost per acre and more importantly reduce the probability of soil and water pollution. Oscillating Nozzle Agriculture Sprayer is an innovative solution to the above-mentioned problem where four nozzles with oscillating action cover maximum plant foliage area, with effect reach, application of Italian nozzles adds to proper atomization of spray and effective application is attained through the combination of the nozzle and oscillating arm action. The system has been designed, manufactured, and tested in actual conditions. Field test results showed that the cost of spray saved annually is around 25–30% of the pesticide cost for existing tractor-mount spraying mechanisms.

An Improved Parameter-Free Fault Locator for Untransposed Line With Unsynchronized Terminals

This letter presents a novel parameter-free fault location algorithm for a two-terminal single circuit untransposed line with flat and delta conductor configurations while considering unsynchronized measurements. It improves the existing works by introducing unequal angles of synchronism mismatch in pre-fault and fault conditions. EMTP-RV based simulation results corroborate the validity and accuracy of the developed fault location algorithm. Simulation results are also compared with existing methods to demonstrate improved features of the proposed algorithm. Field test results are also presented to further validate the performance of the proposed algorithm.

Fitability of the high-clearance tractor with the 4K4 wheel arrangement at the row spacing

The results of laboratory, field and household tests of a tractor model implemented on sowing and row-spacing processing of cotton-plant during the growing season are specified in the article. Agrotechnical evaluation of damage to plants and knockability of cotton fruit elements by machine-tractor unit, consisting of compared tractors and cultivator, showed that knocking down cotton fruit elements in one pass at tractor with 4K4 wheel arrangement is less by 10% compared to tractor with 3K2 wheel arrangement. The fitability of cultivator on basis of a high-clearance mock tractor with 4K4 wheel arrangement on cotton-plant processing in the fruiting stage according to main indicators complies with the standards established in the Initial requirements.

Methods for efficiency evaluation of MX-1.8 GV cotton pickers in horizontal-spindle design

The article is devoted to determining the economic profitability of MX-1.8 GV cotton pickers in comparison with handpicking. The article presents the results of field tests of a horizontal-spindle design of MX-1.8 GV cotton harvester performance, compared with the results of numerical studies obtained using a computer program. The results obtained were used to further determine the economic efficiency of machine harvesting. The costs of machine and handpicking are determined. On the basis of numerical studies, it was proved that machine harvesting using MX-1.8 GV cotton picker is economically profitable at an open crop yield of more than 2.75 t/ha.

Sourceless LWD Borehole Acoustics: Field Testing the Concept

Seismic compressional and shear velocities are uniquely sensitive to the elasticity of the Earth and are used to estimate many properties of interest in oil exploration, reservoir development, and production efforts. Such properties include formation lithology, porosity, saturation, mechanical properties, presence of fractures, principal stresses, pore pressure, and formation damage. Logging-while-drilling (LWD) acoustic tools can be used when wireline acoustic logging is prohibitive and/or real-time decisions based on acoustics are needed. It has been shown that modern LWD acoustic tools with powerful, specialized acoustic transmitters can deliver most acoustic data and products with the same quality as their wireline counterparts. However, there is a lot of variation in the quality of traditional LWD acoustic data depending on the tool design. The operator’s decision to run an LWD acoustic tool is not an easy one, though, as the tool is often the most complicated and the longest part of the drillstring. In this paper, we present the field test results of a “sourceless” LWD acoustic tool that uses seismic energy generated by the drill bit to extract formation elastic properties instead of a powerful, specialized transmitter. Such a tool may consist of a receiver section of hydrophones only, which compared with traditional LWD tools, significantly simplifies the mechanical design, shortens the length of the tool, and reduces the tool cost. In the absence of an active transmitter, continuously recording the drill-bit energy as the drill bit rotates enables maximizing the signal-to-noise ratio (SNR) of the formation arrivals. In addition, the presence of azimuthally distributed receiver elements at each receiver axial position permits decomposition of the received wavefield into monopole, dipole, and quadrupole components. Processing results of the sourceless tool using time and frequency semblance are compared to those from a traditional LWD acoustic tool in the same well to demonstrate the viability of the concept. We also demonstrate that, in the case of “traditional” LWD acoustic tools, it is beneficial to place the tool transmitter below the receiver array. In this case, the drill-bit energy propagating in the formation along the borehole is “added” to the energy generated by the source and effectively increases the frequency bandwidth of the source signal and improves the SNR of the resulting formation arrivals.

ANALYSIS OF NEEDS FOR THE DEVELOPMENT OF NUMERICAL LITERATURE ASSESSMENT FROM MATHEMATICS LEARNING OUTCOMES REVIEWED FROM PEDAGOGIC PERSPECTIVE

The results of the Program for International Student Assessment (PISA) on a regular basis which have implications for the Computer-Based National Assessment Program (ANBK) which will be implemented by the Ministry of Education, Culture, Research and Technology of the Republic of Indonesia in 2021, make improvements to the mathematics learning assessment instrument through findings. The results obtained from the field test results are considered important to be carried out. This study aims to describe the need for a Numerical Literacy Assessment of Mathematics Learning Outcomes that trains five competencies in learning mathematics, namely problem solving (problem solving), communication (communication), reasoning (reasoning), connection (connection), and representation (representation) by considering pedagogical study. This study involved 10 teacher respondents from several regions in Indonesia. The instrument of this research was a questionnaire and an observation guide to the evaluation of mathematics learning outcomes made by teachers which had been validated by two pedagogic experts and a mathematician. The questionnaire was distributed openly through the google form application. The questionnaire data was processed qualitatively, followed by data reduction, data presentation, discussion and discussion and conclusions. The results of this study include the evaluation instruments made by the teacher are still dominated by multiple choice questions and objective descriptions, respectively 80 and 85% and the finding of the need for improvement in connection competence and mathematical representation which is at the 45% level. . In relation to pedagogy, this needs analysis is considered necessary because the four aspects of evaluation are considered necessary to be applied.

Soil Characteristics of Padma Multipurpose Bridge

Padma Multipurpose Bridge is situated on a section of the Padma river where the soil condition is highly heterogeneous and intermixed with different soil layers, for which pile design was the critical part. This paper describes the soil properties and ground profiling of the Padma Multipurpose Bridge. Different types of field and laboratory tests were carried out to obtain accurate soil parameters and ground profiles along the whole alignment of the bridge. Standard Penetration Tests, Cone Penetration Tests, and grain size analyses were conducted for the soil classifications and ground profiling. Flat Plate Dilatometer Tests, High Pressure Dilatometer Tests, and Self-Boring Internal Friction Tests were performed to obtain the stiffness of the different soil layers and shear strength parameters in field conditions. Cross-hole and Seismic Tomography Geophysical tests were executed to obtain seismic waves and dynamic shear modulus of each soil layer. Gel Push Soil Sampling technique was used to collect undisturbed samples of sandy soils to get accurate stress–strength-dilatancy characteristics of sandy soils through different laboratory tests. The soil was classified into three Units and some sub-units based on grain size and SPT-N value. Soil parameters were finalized based on both laboratory and field test results. The pile design was possible for accurate measurement of soil parameters and ground profiling along the alignment of the bridge.

Effects of Uplift Resistance on Continuous-Pipe-Foundation of Single-Span Plastic Greenhouse by Steel Plate Pipe Connector

The single-span plastic greenhouses are affected by strong winds which generate uplift resistance causing the bending of members, damage to protective films, and damage to crops. This study performed a field test using the static axial tensile load method to present basic data to prevent damage to a single-span plastic greenhouse. Three representative areas were selected, and the effects of pipe connectors, rafter spacing, and embedding depth were tested. In the field test results, it was found to be greatly affected by the pipe connector. The pull-out resistance at the site fixed by welding instead of the pipe connector was measured as 4.5 times the sliding resistance standard value of the Rural Development Administration. In other sites, the measurement was below the standard value of the sliding resistance of the pipe connector. It was confirmed that the uplift resistance is determined by the sliding resistance of the pipe connector, the rafters, and the crossbar pipe. Therefore, it seems possible to increase the uplift resistance of a single-span plastic greenhouses continuous foundation through the reinforcement of the pipe connector. The field test results can be utilized as basic data for the reinforcement of the commercialization of single-span plastic greenhouses and new standards.

Tire normal force estimation using artificial neural networks and fuzzy classifiers: Experimental validation

Tire normal forces play a crucial role in vehicle dynamic control systems (VDCs), and an accurate estimation of them could substantially improve vehicle handling and safety. Total normal forces on tires are the combination of the static and dynamic values. These values change by varying the vehicle static parameters (vehicle mass and CG position), the road grade, and vehicle dynamic states. All of the mentioned forces and parameters are used in the design of vehicle dynamics controllers. Therefore, to have an efficient estimation solution to access all different target controllers, the proposed estimation algorithm is divided into two parts. The first part is an ANN-based vehicle mass and CG position estimation algorithm and the second one is a deep-learning-based algorithm and an integrated hardware–software method to estimate dynamic normal forces. The first part includes two neural network (NN) blocks related to vehicle roll and pitch dynamics. The outputs of the NN blocks are load distributions for the axes associated with each dynamics. Based on the measurement unit data, the vehicle’s maneuvers are classified into one of many categories used for downstream tasks. The rules of the fuzzy classification logic determine which of the mentioned blocks to be activated. At the same time, an experimentally validated 9-DOF vehicle model instantaneously observes the estimated values. In the second part, long short-term memory (LSTM), gated recurrent unit (GRU), and an integrated hardware–software method were developed to assess the tire’s dynamic normal forces during maneuvers. The performed simulations and the results of field tests show that the proposed algorithm can accurately estimate the considered parameters in the presence of noise and disturbances. It is shown that the proposed algorithm is more accurate and faster than the extended Kalman filter and recursive least square estimation methods to estimate static values.

Optic Chiasmal Enhancement Revealed by Magnetic Resonance Imaging in a Patient with Ethambutol-induced Toxic Optic Neuropathy

Purpose: We report a bitemporal visual field defect accompanied by optic chiasmal enhancement in a patient with ethambutol (EMB)-induced toxic optic neuropathy.Case summary: A 53-year-old woman presented with bilateral visual disturbance that had gradually worsened over the prior 2 months. She had been prescribed 800 mg EMB daily to treat pulmonary tuberculosis for the past 10 months but had stopped EMB 1 month prior because of visual disturbance. She had been prescribed 600 mg rifampicin and 1,000 mg clarithromycin daily for 11 months. Her visual acuity was 0.2 in the right eye and 0.1 in the left. Color vision was reduced. Automated perimetry demonstrated a bitemporal visual field defect, which was more severe in the left eye. Magnetic resonance imaging (MRI) of the optic chiasm revealed contrast enhancement in the body of the chiasm. The optic nerve of the left eye evidenced a higher signal intensity than did that of the right, consistent with the visual field test results. One month after her initial visit, the visual symptoms deteriorated further. We delivered high-dose, intravenous steroid pulse therapy (methylprednisolone 1,000 mg daily for 3 days). At the 1-year follow-up, the visual acuity was 0.4 in the right eye and 0.1 in the left.Conclusions: Bitemporal hemianopia may develop in patients with EMB-induced toxic optic neuropathy. Enhancement of the optic chiasm, consistent with the visual field defect, could be observed in MRI.

Effects of SCR catalyst breakage on mercury emission properties in coal-fired power plant: field testing and laboratory evaluation

Field testing toward mercury emission properties was conducted at a 300 MW coal-fired power station. Selective catalytic reduction (SCR) was found to reduce Hg content in flue gas significantly through catalyst breakage during the commercial testing in a 300 MW coal-fired power station. Field testing results indicate that the total mercury concentration in flue gas at electrostatic precipitator (ESP) inlet and ESP outlet increase due to SCR catalyst breakage. Correspondingly, mercury content in fly ash decrease and mercury content in gypsum increase. The evolution in laboratory confirmed the Hg0 oxidation capability of commercial SCR catalyst. Catalyst breakage leads to space velocity increasing, so that the lower Hg0 oxidation rates caused the mercury transformation change in flue gas and solid byproducts.

Study on recyclable precast-slab-fabricated road based on arching effect theory

Precast slab parameters are important factors affecting the mechanical performance and service life of precast-slab-fabricated recyclable roads. To clarify the force mechanism of recyclable precast-slab-fabricated roads and provide a basis for selecting slab parameters, a field test of a recyclable road fabricated using a large-scale precast slab was conducted in this study. The horizontal and vertical stresses on the top and bottom surfaces of the precast slab are determined. The stress-time history curves show that the horizontal and vertical stresses have peak values corresponding to the time at which the axle acts directly on the precast slab. Based on the arching effect theory, the mechanical mechanism of a precast-slab-fabricated recyclable road was analyzed. Owing to the arching effect between the precast slabs, they were cooperatively stressed. Compared with precast slab bearing vehicle load independently, When the arch effect works, both the maximum horizontal stress and the vertical stress decrease. According to the field test results, the influence laws of the material, size, thickness, and shape of the precast slab on precast slab stress were obtained. In order to achieve maximum service life and road performance of recyclable Precast-Slab-Fabricated road, the characteristic parameters of the precast slab are suggested as follows. The grade of concrete used for the precast slab should be more than C30, the size of precast slab can be 2 m, large thickness of precast slab should be used(e.g.0.2 m), and square precast slab with width-length ratio of 1 should be adopted as far as possible.

Design and Verification of Crab Steering System for High Clearance Self-Propelled Sprayer

A crab steering system aiming at improving the steering flexibility and operation efficiency of the high clearance sprayer was designed. First, a steering transmission mechanism of the high clearance sprayer was designed according to the operational and structural characteristics of the sprayer. Meanwhile, a crab steering hydraulic system based on load sensing was designed, and a mathematical model of the steering transmission mechanism and hydraulic system was established to describe the working characteristics of the crab steering system. On the basis of analyzing the operating environment of the sprayer and the operating characteristics of crab steering mode, a control strategy and algorithm of the crab steering system were proposed. The simulation model of the crab steering control system was built according to the established mathematical model, and the simulation analysis of the crab steering system was carried out. The simulation results showed that under the excitation of step signal, the average deviation of the two front wheels is 0.063°, and the absolute value of the maximum deviation is 2.75°, which is within the allowable range of deviation and meets the crab steering demand of the sprayer. Additionally, in order to verify the effectiveness of the designed system, an actual vehicle test platform of the crab steering system was built based on the 3WPG-3000 high clearance self-propelled sprayer independently developed by the research group, and the field test results revealed that the average deviation of the four wheels was 0.285°, the maximum absolute deviation was 2.587°, the rotation deviation was small, within the allowable and reasonable range. Altogether, the results of the simulation and field test verify the accuracy, stability and practicability of the crab steering system, which effectively improved the maneuverability of the sprayer.

Long-Term Antimicrobial Performance of Textiles Coated with ZnO and TiO2 Nanoparticles in a Tropical Climate.

This paper reports the results of the large-scale field testing of composite materials with antibacterial properties in a tropical climate. The composite materials, based on a cotton fabric with a coating of metal oxide nanoparticles (TiO2 and/or ZnO), were produced using high-power ultrasonic treatment. The antibacterial properties of the materials were studied in laboratory tests on solid and liquid nutrient media using bacteria of different taxonomic groups (Escherichia coli, Chromobacterium violaceum, Pseudomonas chlororaphis). On solid media, the coatings were able to achieve a >50% decrease in the number of bacteria. The field tests were carried out in a tropical climate, at the Climate test station "Hoa Lac" (Hanoi city, Vietnam). The composite materials demonstrated long-term antibacterial activity in the tropical climate: the number of microorganisms remained within the range of 1-3% in comparison with the control sample for the duration of the experiment (3 months). Ten of the microorganisms that most frequently occurred on the surface of the coated textiles were identified. The bacteria were harmless, while the fungi were pathogenic and contributed to fabric deterioration. Tensile strength deterioration was also studied, with the fabrics coated with metal oxides demonstrating a better preservation of their mechanical characteristics over time, (there was a 42% tensile strength decrease for the reference non-coated sample and a 21% decrease for the sample with a ZnO + CTAB coating).

Operational modal analysis under harmonic excitation using Ramanujan subspace projection and stochastic subspace identification

The presence of deterministic harmonic excitation, such as that induced by rotating machinery, violates the classical operational modal analysis (OMA) assumption that the system output is strictly ergodic. This paper proves that the presence of harmonic excitation has no effect on the identification of structural modes except in the case where some of the harmonic excitation frequencies are close to the structural frequencies. Therefore, the harmonic component must be removed from the mixed random and harmonic system output before further processing. This paper proposes a Ramanujan subspace projection (RSP) method for harmonic removal, which is realized by projecting the raw system output onto the complex conjugate division (CCD) of the Ramanujan subspace. The novelty of this study is that it reveals the relationship between the frequencies defined in the period and frequency domains, allowing the RSP method to directly extract the harmonic component from the specific CCD without any frequency domain analysis. In addition, an energy indicator is proposed to select the underlying CCDs with the most robust harmonic feature. Using the indicator, one only needs to project the raw system output onto a subset of the CCDs rather than all of them, thereby significantly reducing the computational effort. After removing the harmonic components from the raw output, the remainder can be fed into the covariance-driven stochastic subspace identification (Cov-SSI) method for OMA. The numerical, experimental and field test results show that the proposed RSP method is not only resistant to random noise but also capable of precisely extracting the weak harmonic component from the raw output with less computation. Furthermore, the modal parameters of the structures subjected to mixed random and harmonic excitation can be accurately identified by combining the Cov-SSI and RSP methods.

Ultrasonic thickness measuring in-pipe robot for real-time non-destructive evaluation of polymeric spray linings in drinking water pipe infrastructure

Drinking water pipelines are mainly underground and exposed to corrosion. Polymeric spray liners are used as an economical renewal method to mitigate the consequences of internal corrosion of pipelines and prolong their useful service life by many water utilities around the globe. The quality assurance of such applications is currently limited to closed-circuit television (CCTV), which only provides visual information. As part of the Australian government-funded, thirty-four partner multi-million dollar project (CRC-P: Smart Linings for Pipes and Infrastructure project), this work focuses on measuring the post-application thickness of spray liners in pipes. In this article, we report the innovative development of in-pipe robotic sensing suite that leverages ultrasonic sensing to continuously inspect the thickness of the spray linings through non-destructive measurements. The ultrasonic sensor was calibrated by fabricating laboratory test sample made from polymeric spray linings. Continuous uninterrupted coupling was achieved through a custom designed mechanism which was proven to be reliable through field deployments. Extensive lab tests were conducted to validate the sensor measurements with the benchmark measurements producing results with sub-millimeter accuracy. Following lab validations, field trials in buried pipe assets of Sydney Water were conducted for pipe lengths over 35 m, and the field test results show the robotic system is capable of reliably providing accurate spray liner thickness along the pipeline in real-time through non-destructive evaluation.