Experimental Field Tests Research Articles

Automated Method for Controlling Oil Filling of Polymer and Composite Materials

For the modernization of polymer and composite materials in order to increase their operational properties, namely strength and wear resistance, there are created oil-filled polymer and composite materials. Filling the manufactured part with oil is problematic in the automating the control of the filled state. The filling process is applicable for polymer or composite bearing separators of agricultural machines (forage harvesters, cotton harvesters, grape harvesters and others) in order to increase their service life in conditions of a large amount of dust and dirt, as well as in cases of dry start. (Research purpose) The research purpose is in developing a methodology for automated filling control of structural polymers and composites used in agricultural machinery with antifriction materials. (Materials and methods) The article presents designed and produced experimental installation and field tests. The developed sensor placement scheme allows performing experimental studies on measuring the volumetric body temperature of a polymer or composite sample during the impregnation process online. The differentiation of the obtained results, presented in graphical form, makes it possible to quickly analyze the dynamics of temperature changes in the thickness of the material. (Results and discussion) The article presents the optimal proportion of a mixture of hexane and M-8B engine oil and the most favorable temperature conditions. It was confirmed the possibility of using this technique in the technology of oil filling of antifriction products made of polymer and composite materials. (Conclusions) The technique makes it possible to identify the filled state of manufactured polymer or composite parts used in friction units of agricultural machines without the introduction of thermal sensors. The control is carried out according to the previously obtained values of the speed and time of impregnation to a given depth of penetration of the oil filler, depending on the type of material.

Assessment of Corrosion in Offshore R.C. Piers and Use of Microsilica to Reduce Corrosion Induced oxidation (A Case Study of Wharves 11 and 12 in Imam Khomeini Port-IRAN)

reinforced concrete structures in these are as exposed to chloride aggressive marine environments. Therefore, it is important to provide protection and offer appropriate repair methods of buildings vulnerable to the degrading effects of corrosion. The present study sets out to identify and evaluate the causes and extent of corrosion observed in piers Imam Khomeini port. The microsilica is used to reduce corrosion. In order to achieve the above-mentioned goals, a number of experimental field tests were performed to determine the level of concrete condition in terms of reinforcement corrosion. Some tests were conducted to determine the conditions concrete piers in terms of reinforcement corrosion. Then a reinforcement corrosion density test is performed by using Potentiostat test involving a placement process; with different water-to-cement ratios and superplasticizers, the microsilica content was 5%, 10%, and 15%. And microsilica can serve as an alternative to cement and was measured according to ASTM standards. Microsilica was exposed to aggressive conditions at different periods and a concrete compressive strength test was performed. The results show that the compressive strength and corrosion resistance of the concrete increased for concrete mixture containing 10% microsilica with a water-to-cement ratio of 34% and a superplasticizer ratio of 6

Evidence of soil-structure interaction from modular full-scale field experimental tests

Evidence of soil-structure interaction from modular full-scale field experimental tests

Danzhi Xiaoyao Powder Promotes Neuronal Regeneration by Downregulating Notch Signaling Pathway in the Treatment of Generalized Anxiety Disorder

Background: Generalized anxiety disorder (GAD) is one of the most common types of anxiety disorders with unclear pathogenesis. Our team’s previous research found that extensive neuronal apoptosis and neuronal regeneration disorders occur in the hippocampus of GAD rats. Danzhi Xiaoyao (DZXYS) Powder can improve the anxiety behavior of rats, but its molecular mechanism is not well understood. Objective: This paper discusses whether the pathogenesis of GAD is related to the abnormal expression of Notch signal pathway, and whether the anti-anxiety effect of DZXYS promotes nerve regeneration in the hippocampus by regulating the Notch signaling pathway. Methods: The animal model of GAD was developed by the chronic restraint stress and uncertain empty bottle stimulation method. After the model was successfully established, the rats in the model preparation group were divided into the buspirone, DZXYS, DZXYS + DAPT, and model groups, and were administered the corresponding drug intervention. The changes in body weight and food intake of rats were continuously monitored throughout the process. The changes in anxiety behavior of rats were measured by open field experiment and elevated plus-maze test, and morphological changes and regeneration of neurons in the rat hippocampus were observed by HE staining and double immunofluorescence staining. Changes in the expression of key targets of the Notch signaling pathway in the hippocampus were monitored by real-time fluorescence quantitative PCR and western blotting. Results: In this study, we verified that the GAD model was stable and reliable, and found that the key targets of the Notch signaling pathway (Notch1, Hes1, Hes5, etc.) in the hippocampus of GAD rats were significantly upregulated, leading to the increased proliferation of neural stem cells in the hippocampus and increased differentiation into astrocytes, resulting in neuronal regeneration. DZXYS intervention in GAD rats can improve appetite, promote weight growth, and significantly reverse the anxiety behavior of GAD rats, which can inhibit the upregulation of key targets of the Notch signaling pathway, promote the differentiation of neural stem cells in the hippocampus into neurons, and inhibit their differentiation into astrocytes, thus alleviating anxiety behavior. Conclusion: The occurrence of GAD is closely related to the upregulation of the Notch signaling pathway, which hinders the regeneration of normal neurons in the hippocampus, while DZXYS can downregulate the Notch signaling pathway and promote neuronal regeneration in the hippocampus, thereby relieving anxiety behavior.

Desiccation-induced curling of mud layers: Field observations and experimental insights

Desiccation-induced curling of mud layers on the earth surface is a ubiquitous natural phenomenon, as a result of mud-atmosphere interaction. Field observations reveal that the curling behaviors of muds were closely related to the overlying layer thickness and the basal layer condition. In order to interpret field observations, laboratory experiments were conducted on ten remolded mud samples with varying overlying layer thicknesses and basal conditions. Experimental results are consistent with field observations and provide insights into the dynamic mud curling process. During drying, the mud curling is driven by the shrinkage strain gradient along the mud profile. For a thin overlying mud layer, the mud curling is unidirectional, either upward (∪) or downward (∩), depending on the basal condition. For a thick overlying layer, the mud begins with upward curling and then recovers. Increasing the layer thickness not only weakens the mud curling but also improves the curling recovery capacity. Furthermore, under a stratified structure, the overlying mud curling is significantly influenced by the interplay of the capillary and friction forces developed at the mud undersurface. Both factors are strongly associated with the basal particle size. The decreasing basal layer particle size smoothens the interface, probably causing the unidirectional downward curling of the overlying layer. However, a rougher basal layer may induce that the overlying mud curls initially at a higher water content and undergoes a more noticeable upward curling. Through field observations and experimental tests, this study is expected to advance the current understanding of various mud curling processes.

Experimental research on vibration and noise of rail conveyor

Rail Conveyor is a highly energy-efficient and cost-effective bulk material transportation system, which merges the benefits of both belt conveyor technology and railway. Reducing vibration and noise is a key problem in the design of rail conveyor system, which has great social and economic significance for the realization of green environmental protection and sustainable development of bulk materials transportation. This article describes the field experimental test of vibration and noise. The vibration acceleration of rail conveyor was tested under different belt speed and different carriage spacing and different wheel materials of support carriage, and the noise of rail conveyor was tested under different belt speed and different test distance. Experimental results and analysis show that: With the increase of belt speed, the vibration and noise of wheel and rail of rail conveyor increase greatly, and the wheel rail vibration and noise decrease with the increase of the distance between the support carriages, and the wheel material has a great influence on the vibration.

Prototyping, Testing, and Redesign of a Three-Wheel Trekking Wheelchair for Accessible Tourism Applications

This work is part of the project called “Gölem project”, started in 2017, about special devices developed to enable the so-called Accessible Tourism. This project aims to design and develop a trekking wheelchair for people with impaired mobility. After an initial phase of design and prototyping, the testing phase has now begun. The objective is to validate several aspects of the design, concerning basic kinematics and dynamics, passenger comfort and physical effort of the carriers. This paper describes the development of qualitative tests for drivability and balance validation of this first prototype. At this stage, a list of features to be investigated was made, suitable trekking paths were chosen, and qualitative experimental field tests were performed. Then, the design of the prototype was modified according to these first experimental results, to improve the wheelchair characteristics. The prototype is now undergoing the modification phase, then further testing will be performed with the use of specific instrumental devices to evaluate the wheelchair itself and to perform the kinematic, dynamical, and comfort characterization.

On-Site Calibration Method for Line-Structured Light Sensor-Based Railway Wheel Size Measurement System.

Line-structured light has been widely used in the field of railway measurement, owing to its high capability of anti-interference, fast scanning speed and high accuracy. Traditional calibration methods of line-structured light sensors have the disadvantages of long calibration time and complicated calibration process, which is not suitable for railway field application. In this paper, a fast calibration method based on a self-developed calibration device was proposed. Compared with traditional methods, the calibration process is simplified and the calibration time is greatly shortened. This method does not need to extract light strips; thus, the influence of ambient light on the measurement is reduced. In addition, the calibration error resulting from the misalignment was corrected by epipolar constraint, and the calibration accuracy was improved. Calibration experiments in laboratory and field tests were conducted to verify the effectiveness of this method, and the results showed that the proposed method can achieve a better calibration accuracy compared to a traditional calibration method based on Zhang’s method.

Dual Quaternion Cluster-Space Formation Control

We present a tracking controller for mobile multi-robot systems based on dual quaternion pose representations applied to formations of robots in a leader-follower configuration, by using a cluster-space state approach. The proposed controller improves system performance with respect to previous works by reducing steady-state tracking errors. The performance is evaluated through experimental field tests with a formation of an unmanned ground vehicle (UGV) and an unmanned aerial vehicle (UAV), as well as a formation of two UAVs.

Development of an airborne gamma-ray spectrometer based on a CZT detector

An airborne survey system named the MARK-A1 was developed to be mounted on a commercial drone for the purpose of application in contaminated areas with high dose rate levels. The MARK-A1 system consists of a CZT detector, signal processing unit, and positioning and interface units to a PC on the ground. The weight of the system is below 1 kg for loading on a commercial drone. For experimental verification, irradiation testing and field testing were conducted. From the irradiation test, we derived the G-factor and dose rate calibration factor to calculate ambient dose rates from measured energy spectra with an applicable energy range. An airborne survey was then conducted to check the system performance at a height of about 1 m and 10 m. The ambient dose rate was successfully estimated from the calculation of the measured energy spectra and dose conversion factor. Finally, the results were compared with those from in situ gamma-ray spectrometry using a tripod at the same survey site. The difference between the two systems was below 20%, indicating a good performance of the MARK-A1. It is anticipated that the MARK-A1 can be used to quickly scan wide, highly contaminated areas that are difficult for humans to access in the event of a radiological accident.

Numerical Simulation Study on Heat Transfer Mechanism of Excavation Based Enhanced Geothermal System

The innovative excavation based EGS (EGS-E) scheme uses mining techniques to form deep underground access for creating artificial heat reservoir with multi-level fracture networks using excavation, blasting, and caving. The two-level heat transfer mechanism of distributed artificial heat reservoir has a dominant influence on the performance of excavation based Enhanced Geothermal System(EGS-E). However, due to the large-scale field testing and laboratory physical experiment are not yet realistic, the process of natural convection heat transfer within the surrounding rock enhanced permeability and water filled zones hasn’t been effectively studied. The simulation software COMSOL Multiphysics was used to numerically simulate the natural convection heat transfer within the enhanced stimulated surrounding rock around a single straight roadway with its circular opening, which should be an elemental unit for mining heat in deep underground engineering structure. The simulation results demonstrated that the temperature difference inside the surrounding rock of a roadway causes the density of working fluid to vary. Driven by buoyancy, the natural convection of working fluid occurs in the surrounding rock. It enhances the heat transfer inside hot dry rock, and its efficiency is significantly more remarkable than that of the conduction through hot dry rock itself, which can improve the efficiency of heat recovery with regards to EGS-E. Due to the low solid heat conduction efficiency of the surrounding dry hot rock, adjusting the speed of the water flow inside the pipe can effectively control the temperature of the water outlet to improve the heat collection life of the system.

Persisting effects of social norm feedback letters in reducing household electricity usage in Post-Soviet Eastern Europe: A randomized controlled trial

In a large-scale randomized field experiment in Chisinau, Moldova, with over 120,000 households, we tested the influence of a simple, one-time letter presenting electricity-usage social comparison feedback. The letter was framed in either kilowatt-hour units or monetary values. We find that both letter versions significantly reduce recipient households’ electricity consumption by 1.7–2.1 percent in the following month, and the effect persists for at least three months. The effect's magnitude and duration resemble those seen in similar trials in the U.S., even though Moldova's average household electricity consumption level is much lower. As the first large-scale field experiment testing social comparison energy reports in a post-Soviet environment, this study provides empirical evidence that non-price nudges can be an inexpensive yet useful energy conservation policy tool even in non-Western and less industrialized settings. We explore the relationship between Moldova's socioecological contexts and environmental attitudes as a former Soviet Union country and the relatively strong social norm effect that we observed.

A novel solution with rapid Voronoi-based coverage path planning in irregular environment for robotic mowing systems

This paper presents a novel solution of coverage path planning for robotic mowing applications. The planning algorithm is based on the Boustrophedon motions and the rapid Voronoi diagram. The coordinate conversion and the sweeping vector is defined by minimum bounding box and the Voronoi travel paths are designed to reduce the computational cost and execution time compared to conventional heuristic methods. The tracked path is controlled via dynamic feedback in standard lawn mowing robots under robot operating system (ROS). Within ROS, the information exchanging among different tasks of both extensive simulation cases and experimental field tests can be conducted easily. When meeting unknown obstacles, the proposed algorithm can re-plan its paths dynamically. The performance of the proposed algorithm is compared to several conventional coverage algorithms in terms of time efficiency, coverage, repetition, and robustness with respect to both concave and convex shapes. The field tests are conducted to demonstrate that the applicability of the sensor fusion and robustness of the proposed algorithm for the complete coverage tasks by robotic mowers.

Metabolism drives demography in an experimental field test

Metabolism should drive demography by determining the rates of both biological work and resource demand. Long-standing "rules" for how metabolism should covary with demography permeate biology, from predicting the impacts of climate change to managing fisheries. Evidence for these rules is almost exclusively indirect and in the form of among-species comparisons, while direct evidence is exceptionally rare. In a manipulative field experiment on a sessile marine invertebrate, we created experimental populations that varied in population size (density) and metabolic rate, but not body size. We then tested key theoretical predictions regarding relationships between metabolism and demography by parameterizing population models with lifetime performance data from our field experiment. We found that populations with higher metabolisms had greater intrinsic rates of increase and lower carrying capacities, in qualitative accordance with classic theory. We also found important departures from theory-in particular, carrying capacity declined less steeply than predicted, such that energy use at equilibrium increased with metabolic rate, violating the long-standing axiom of energy equivalence. Theory holds that energy equivalence emerges because resource supply is assumed to be independent of metabolic rate. We find this assumption to be violated under real-world conditions, with potentially far-reaching consequences for the management of biological systems.

Seismic vulnerability assessment indices for buildings: Proposals, comparisons and methodologies at collapse limit states

Seismic vulnerability assessment of existing buildings is an essential process for earthquake disaster management. It can support decision-makers to estimate critical response parameters and improve them. While several seismic vulnerability assessment techniques have been introduced over the past years, a detailed formulation to measure the vulnerability index of existing buildings along with the operative procedure is still lacking. Current standards and literature worldwide mostly propose simplified approaches (e.g. based on limited engineering analyses, visual inspection) to perform a rapid vulnerability assessment that can be useful when a large number of buildings should be analyzed. This paper presents a methodology to perform the seismic vulnerability assessment of existing buildings at collapse, analyzing a standard vulnerability index, and proposing alternative formulas. The methodology combines field investigations and experimental tests with nonlinear structural analyses. It has been applied to a case study that consists of an existing reinforced concrete school building to analyze and compare the proposed indices with respect to different ground motion selection procedures. Furthermore, a detailed comparison with alternative vulnerability indices from literature has been also performed.

Can nudging overcome procrastinating on preventive health investments?

A fundamental puzzle about human behavior is low investment in preventive health inputs. Present-biased preferences have frequently been put forth as a theoretical explanation for this, but with limited empirical evidence supporting it, especially in developing countries. We extend our previous analysis of a field experiment testing advertising strategies to increase demand for a potentially life-saving preventive health technology, voluntary medical male circumcision. Offering compensation of US$10 conditional on a complement to the procedure, a short counseling session at a providing clinic, tripled uptake of the procedure. This is consistent with the idea that subsidizing a complement encouraged procrastinating men with latent demand to invest in preventive health. In addition, framing the basic advertisement using the statement “Are you tough enough?” doubled uptake.

Distributed Fiber Optic Strain Sensing for Geomechanical Monitoring: Insights from Field Measurements of Ground Surface Deformation

In recent years, distributed fiber optic strain sensing (DFOSS) technology has demonstrated a solution for continuous deformation monitoring from subsurface to surface along the wellbore. In this study, we installed a single-mode optical fiber cable in a shallow trench to establish an effective technique for ground surface deformation mapping. We conducted three experimental field tests (iron plate load, water tank filling up load, and airbag inflation) in order to confirm the strain sensitivity of DFOSS for static loads, dynamic overload, excavation, subsidence, and uplift. This paper also presents two installation methods to couple the fiber cable with the ground under various environmental conditions; here, the fiber cable was installed in a shallow trench with one part buried in the soil and another part covered with cement. Our results suggest that covering the cable with cement is a practical approach for installing a fiber cable for ground surface deformation monitoring. By combining this approach with wellbore DFOSS, accurate surface–subsurface deformation measurements can be obtained for three-dimensional geomechanical monitoring of CO2 storage and oil and gas fields in the future.

Rotation with oilseed rape as the winter crop enhances rice yield and improves soil indigenous nutrient supply

Crop yield and soil fertility are significantly influenced by crop rotation practices and plant nutrition management. A 3-year field experiment testing different fertilizer inputs under oilseed rape–rice (OR), wheat–rice (WR), and fallow–rice (FR) rotations was performed to investigate the effects of different rotations on rice yield and soil indigenous nutrient supply. Rice yield under the OR rotation was significantly higher than yields under the other two rotations, especially when no fertilizer was applied (control treatment) or when the applied fertilizer lacked N (no-N treatment). The rice grain yields of the control and no-N treatments under OR rotation exceeded those under the WR and FR rotations by 20.5 % and 14.5 % (control), and by 16.2 % and 14.9 % (no-N), respectively. The increase in rice yield was significantly related to the soil indigenous nutrient supply. Linear regression analysis showed that for every 1.0 kg increase in soil N supply, the rice yield increased by 86.2–136.8 kg ha–1. The indigenous N supply in the rice season under OR rotation was 22.0 % and 19.5 % higher than supplies under WR and FR rotations, respectively. The indigenous P and K supplies under OR were 21.9 % and 12.8 % higher, respectively, than those under WR. The highest N and P surpluses and lowest K deficits occurred under OR rotation. These effects were significantly correlated with the soil indigenous nutrient supply. Thus, a surplus of 1.0 kg N ha–1 increased the soil indigenous N supply by 0.04–0.29 kg N ha–1. Consequently, the use of oilseed rape as a previous crop in a rotation protocol could significantly increase rice yield and soil indigenous nutrient supply capacity. Inclusion of this rotation practice into agronomic systems that currently use wheat-rice and fallow-rice rotations should bring significant benefits.

Effects of long-term sand mixing ameliorating measures on soil salinity characteristics of saline-alkali land in northern Shaanxi

To explore different mix sand measures of saline-alkali land improvement effect for a long time, this study in northern shaanxi dingbian county saline-alkali soil as the research object, combined with field experiment and indoor test methods in the wild, analysis and improvement of saline-alkali soil salt and 1 ~ 6 years change characteristics of organic matter, reveal different mix sand thickness of heavy saline-alkali soil salt content and organic matter distribution. The results showed that the overall soil salt content in saline-alkali land did not change regularly with the change of sediment mixing amount or improvement years. There is no significant difference between different thickness (proportion) sand mixing measures on saline-alkali land improvement benefits. As time goes by, the soil salt content in the whole soil layer of saline-alkali land is not significantly changed by sand mixing treatment, but the soil salt content in arable layer is decreasing year by year, and the improvement benefit is significant in the short term. In conclusion, the long-term sand mixing improvement measures are beneficial to the improvement of the cultivated layer of saline-alkali land, thus reducing the salt damage suffered by crops in the process of growth and development, etc., the effects of sand mixing treatment on soil microorganisms and enzyme activities remain to be further explored.

Natural durability and improved resistance of 20 Amazonian wood species after 30 years in ground contact

Abstract This study aimed to assess the natural durability of 20 Amazonian wood species preserved with chromated copper arsenate (CCA) after 30 years in ground contact in an experimental field test at National Forest of Tapajós, Pará state - Brazil. Heartwood samples with a cross-section of 5 × 5 cm and 50 cm of length were half-buried in soil and inspected every year for decay. The species were classified according to natural durability following the classification method proposed by Findlay (Findlay, W.P.K. (1985). The nature and durability of wood. In: Findlay, W.P.K. (Ed.), Preservation of timber in the tropics. Springer Science, Whitchurch, pp. 1–13). After 30 years in ground test, six species were classified as Perishable, seven as Non-durable, three as Durable and four as Very durable, namely: Trichilia lecointei, Lecythis pisonis, Pseudopiptadenia suaveolens, and Dipteryx odorata (Very durable), Protium tenuifolium, Dinizia excelsa, and Ormosia paraensis (Durable), Endopleura uchi, Goupia glabra, Pouteria egregia, Tachigali chrysophylla, Tachigali paraensis, Vatairea sericea, and Vochysia maxima (Non-durable) and Chrysophyllum lucentifolium, Couratari oblongifolia, Didymopanax morototoni, Lueheopsis duckeana, Sterculia excelsa, and Xylopia nitida (Perishable). CCA preservative treatment was effective to promote timber protection, even under harsh climatic conditions of the Amazon forest environment.