Meters In Depth Research Articles

Numerical Modeling for Flexural Behavior of UHPC Beams Reinforced with Steel and Sand-Coated CFRP Bars

Many properties of advanced materials need to be studied, including ultra high performance concrete (UHPC) as well as the Carbon Polymer Reinforcing Fiber (CFRP) rods of sand coated surfaces. The combined action of (UHPC) with (CFRP) is of constructive importance for researchers to know the behavior of the structural members in different loading stages. Eight samples were prepared with dimensions of 2.4 meters in length, 0.25 meters in depth, and 150 mm in width. The compressive strength of 110 MPa was selected after preparing many trail mixes. A computer model by ANSYS 11 program was made for the representation of all inputs, including steel fibers. All Parts of beams, testing accessories, and loads were simulated with adequate elements. The study examined the effect of the orientation of steel fibers on the flexural capacity in terms of load-deflection response. It was concluded that the distribution of the steel fibers plays a fundamental role in the behavior of the models, and thus the optimal distribution was found to be orthogonal distribution to the longitudinal direction of UHPC beam in equal ratios.

Post-Seismic Deformation Related to the 2016 Central Italy Seismic Sequence From GPS Displacement Time-Series.

The 2016–2017 Central Italy earthquake sequence struck the central Apennines between August 2016 and October 2016 with Mw ∈ [5.9; 6.5], plus four earthquakes occurring in January 2017 with Mw ∈ [5.0; 5.5]. We study Global Positioning System time series including near‐ and far‐field domains. We use a variational Bayesian independent component analysis technique to separate the post‐seismic deformation from signals caused by variation of the water content in aquifers at hundreds of meters of depth and of the soil moisture. For each independent component, realistic uncertainties and a plausible physical explanation are provided. We focus on the study of afterslip on the main structures surrounding the mainshock, highlighting the role played by faults that were not activated during the co‐seismic phase in accommodating the post‐seismic deformation. We report aseismic deformation occurring on the Paganica fault, which hosted the Mw 6.1 2009 L'Aquila earthquake, suggesting that static stress transfer and aseismic slip influence the recurrence time of nearby (∼50 km further south of the mainshocks) segments. A ∼2–3 km thick subhorizontal shear‐zone, clearly illuminated by seismicity, which bounds at depth the west‐dipping normal faults where the mainshocks nucleated, also shows aseismic slip. Since afterslip alone underestimates the displacement in the far‐field domain, we consider the possibility that the shear zone marks the brittle‐ductile transition, assuming the viscoelastic relaxation of the lower crust as a mechanism contributing to the post‐seismic displacement. Our results suggest that multiple deformation processes are active in the first 2 years after the mainshocks.

Petroleum rock mechanics: An area worthy of focus in geo-energy research

Petroleum rock mechanics: An area worthy of focus in geo-energy research

Multi-source information fusion based on factor graph in autonomous underwater vehicles navigation systems

PurposeThis paper aims to present a multi-source information fusion algorithm based on factor graph for autonomous underwater vehicles (AUVs) navigation and positioning to address the asynchronous and heterogeneous problem of multiple sensors.Design/methodology/approachThe factor graph is formulated by joint probability distribution function (pdf) random variables. All available measurements are processed into an optimal navigation solution by the message passing algorithm in the factor graph model. To further aid high-rate navigation solutions, the equivalent inertial measurement unit (IMU) factor is introduced to replace several consecutive IMU measurements in the factor graph model.FindingsThe proposed factor graph was demonstrated both in a simulated and vehicle environment using IMU, Doppler Velocity Log, terrain-aided navigation, magnetic compass pilot and depth meter sensors. Simulation results showed that the proposed factor graph processes all available measurements into the considerably improved navigation performance, computational efficiency and complexity compared with the un-simplified factor graph and the federal Kalman filtering methods. Semi-physical experiment results also verified the robustness and effectiveness.Originality/valueThe proposed factor graph scheme supported a plug and play capability to easily fuse asynchronous heterogeneous measurements information in AUV navigation systems.

New Radiometric Approaches to Compute Underwater Irradiances: Potential Applications for High-Resolution and Citizen Science-Based Water Quality Monitoring Programs.

Measuring the diffuse attenuation coefficient () allows for monitoring the water body’s environmental status. This parameter is of particular interest in water quality monitoring programs because it quantifies the presence of light and the euphotic zone’s depth. Citizen scientists can meaningfully contribute by monitoring water quality, complementing traditional methods by reducing monitoring costs and significantly improving data coverage, empowering and supporting decision-making. However, the quality of the acquisition of in situ underwater irradiance measurements has some limitations, especially in areas where stratification phenomena occur in the first meters of depth. This vertical layering introduces a gradient of properties in the vertical direction, affecting the associated . To detect and characterize these variations of in the water column, it needs a system of optical sensors, ideally placed in a range of a few cm, improving the low vertical accuracy. Despite that, the problem of self-shading on the instrumentation becomes critical. Here, we introduce a new concept that aims to improve the vertical accuracy of the irradiance measurements: the underwater annular irradiance (). This new concept consists of measuring the irradiance in an annular-shaped distribution. We first compute the optimal annular angle that avoids self-shading and maximizes the light captured by the sensors. Second, we use different scenarios of water types, solar zenith angle, and cloud coverage to assess the robustness of the corresponding diffuse attenuation coefficient, . Finally, we derive empirical functions for computing from . This new concept opens the possibility to a new generation of optical sensors in an annular-shaped distribution which is expected to (a) increase the vertical resolution of the irradiance measurements and (b) be easy to deploy and maintain and thus to be more suitable for citizen scientists.

Basking shark sub-surface behaviour revealed by animal-towed cameras.

While biologging tags have answered a wealth of ecological questions, the drivers and consequences of movement and activity often remain difficult to ascertain, particularly marine vertebrates which are difficult to observe directly. Basking sharks, the second largest shark species in the world, aggregate in the summer in key foraging sites but despite advances in biologging technologies, little is known about their breeding ecology and sub-surface behaviour. Advances in camera technologies holds potential for filling in these knowledge gaps by providing environmental context and validating behaviours recorded with conventional telemetry. Six basking sharks were tagged at their feeding site in the Sea of Hebrides, Scotland, with towed cameras combined with time-depth recorders and satellite telemetry. Cameras recorded a cumulative 123 hours of video data over an average 64-hour deployment and confirmed the position of the sharks within the water column. Feeding events only occurred within a metre depth and made up ¾ of the time spent swimming near the surface. Sharks maintained similar tail beat frequencies regardless of whether feeding, swimming near the surface or the seabed, where they spent surprisingly up to 88% of daylight hours. This study reported the first complete breaching event and the first sub-surface putative courtship display, with nose-to-tail chasing, parallel swimming as well as the first observation of grouping behaviour near the seabed. Social groups of sharks are thought to be very short term and sporadic, and may play a role in finding breeding partners, particularly in solitary sharks which may use aggregations as an opportunity to breed. In situ observation of basking sharks at their seasonal aggregation site through animal borne cameras revealed unprecedented insight into the social and environmental context of basking shark behaviour which were previously limited to surface observations.

Pendekatan Hidrogeomorfologi Dan Pendugaan Geolistrik Untuk Identifikasi Potensi Airtanah Di Jedong Malang

This study aims to identify the potential groundwater in Jedong, Malang, East Java. The hydrogeomorphological approach is a suitable approach to describe the relationship between hydrological and geomorphological processes on and below the earth's surface. The survey of geoelectricity complements the hydrogeomorphological approach. It will give a better description of the groundwater conditions below the earth's surface. Based on the research, there are 2 hydrogeomorphological units in the study area, which are: Volcanic Foot Valley Unit and Volcanic Foot Ridge Unit. The best groundwater potential is in Volcanic Foot Valley Hydrogeomorphological unit, namely Awar-awar Valley and Cokro Valley. The valleys are dominated by gully erosion and landslides. They have surface deposits up to a depth of 7 meters, and lots of outcrops of breccia, pumice, and andesite boulders. The valley’s springs discharge between 56 - 198 m3/day. The average infiltration rate in the valley is 1776 mm / hour, with sandy soil material. The best aquifer consisting of sandy material is more than 10 meters in depth, based on the geoelectrical survey. Water in the aquiclude layer, cannot be exploited because it is breccia and tuff material. The Sawah valley cannot be exploited further because the groundwater potential is very low. This can be identified by the thick water outflow seepage. In the Volcanic Foot Ridge Hydrogeomorphological unit, the groundwater potential is also very small. Hydrogeomorphically, water will flow down the slope to the valley. It will reduce the infiltration rate. In general, the ridge area is only used for settlement, while the slopes are used for dryland agriculture. The geoelectric analysis results show that the groundwater potential is at a depth of more than 45 meters. This research’s results show that the combination of the hydrogeomorphological approach and the geoelectric use will provide a better description of the potential groundwater.

Geophysical Investigation of Babylon archeological City, Iraq

A geophysical survey was carried out at old archeological Babylon City, which is located 90.0 km to the south of Baghdad. Three geophysical methods were applied in this survey. The VES resistivity method, for soil conductivity and layering testing. GPR and magnetic methods, for detecting subsurface archeological bodies. The resistivity results showed values lower than 5.0 ohm. m, and subsurface distortion, which are probably related to buried archeological ruins. Due to the low electrical resistivity of the top soil, the GPR method did not reach a good penetrating depth. Wide range of frequencies, 30 MHz, 250 MHz, 500 MHz, and 100MHz were applied. The high signal attenuation of the top soil resulted in distorted radar-grams with faint shallow anomalies. The GPR survey was conducted at different seasons hoping that the dry conditions of the hot summer could change the top soil electrical resistivity. Nevertheless, few GPR radar- grams show point reflections that related to small dense bodies at depths of 0.8 – 2.0, which could be archeological bricks walls. The magnetic survey was carried out in two stages using Cesium magnetometer of high sensitivity. An area of 140.0 m x 240.0 m was surveyed at the first stage, which is covered by twenty-eight N-S traverses. The preliminary results show the effects of the N-S profiling, which can be removed by directional first derivative filter. It showed indications of subsurface archeological features. In the second stage, an area of 40.0 x 40.0 meters was chosen for detailed survey. The survey is done a long 40 traverses in N-S direction and another 40.0 Traverses along W-E directions. The preliminary results of the both surveys show some differences. These differences were removed by using first derivative filter. They both showed subsurface geometric shapes that are probably related to buried archeological walls. The mathematical modeling results showed walls of widths 0.3-0.4 meters at depths around 0.8 meters. These walls continue down to 2.3-2.5 meters in depth. The magnetic survey also showed many circular high magnetic anomalies within an area of 1.0 – 2.0 meters only. The mathematical modeling suggested that these anomalies could be corresponding to building poles made of andesite or basaltic rocks or they are buried metals objects.

TECHNIQUE FOR CONSTRUCTING A 3D MODEL OF THE GEOTHERMAL POTENTIAL BY THE RESULTS OF GEOPHYSICAL DATA ON THE EXAMPLE OF THE SAMUKH OIL AND GAS-BEARING AREA OF THE LOWER KURINSKY DEPRESSION

It is known that in the center of the Earth the temperature is about 5000 0C and in the direction of the earth's crust it decreases. It is also known that the temperature gradient of the Earth is 3 0C every 100 meters in depth and it is constant throughout the planet. Consequently, the temperature of the Earth's crust is the most beneficial source of heat and energy. It accumulates the energy of the sun and is heated by the focal temperature. In Azerbaijan, at a depth of one meter to 50 meters, the temperature is stable and equal to 5-8 ° C. Keywords: geothermal energy, Earth's crust temperature, temperature gradient, thermal waters, steam turbines and heat pumps, 3D model of the field.

Variations in Short Wave Radiation and Ocean Temperature in the Tropical Indian Ocean

The purpose of this study was to know the results of the relation between short wave radiation (SWR) and sea temperature. This study used data of SWR and sea temperature from RAMA buoy which part of the data was obtained by the INA-PRIMA 2019. Besides, the SWR and Sea Temperature model data from ERA-5 and Copernicus were required to see these spatial and temporal variations. Diurnal analysis to determine the sea temperature responds to SWR parameters. While monthly analysis to see the variations of SWR and the sea temperature during Indian Ocean Dipole (IOD). The results show that there is a different response at sea temperature for each layer to the SWR parameter in diurnal. SWR can affect sea temperatures until 20 meters of depth. There is a time lag between 2 and 3 hours when the sun heats the sea until the sea surface temperature increases. The 20 meters of depth has a lag time until 4 hours. As for 40 to 80 meters of depth, the sea temperature was not longer responded by SWR, and the temperature is changed by the strength of these mixing.Warm pools are generally located in East Indian Ocean and the high SWR were very strong in West Indian Ocean along an anual.

WORKER SAFETY DURING EXCAVATION AND TRENCHING CONSTRUCTION WORK

Earthworks are the integral part of any construction work in civil engineering and building construction. The construction activities performed during earthworks include the following: excavation, earthmoving, earth transport, and earth compaction. During earthworks, the excavation site is subject to harmful, flammable, or hazardous materials, damage to underground installations, the collapse of the earth, and many more risks. Therefore, construction work for trenching and excavation requires the implementation of adequate safety measures. This paper discusses the safety measures for workers during earthworks that involve excavations up to and exceeding one meter in depth.

Local geomorphological gradients affect sedimentary organic carbon storage: A Blue Carbon case study from sub-tropical Australia

Coastal blue carbon systems (mangrove forests, seagrass meadows and tidal saltmarshes) are renowned for their efficacy at sequestering large amounts of carbon (C) in sedimentary sinks and effective management action to preserve these C stocks requires an understanding of spatial variability within an estuary. This study analysed 33 coastal blue carbon sediment cores across three subtropical estuaries of Eastern Australia. We measured depth, C content and dry bulk density down the soil profile. Mean C stocks for mangroves, seagrass and saltmarsh, up to a 3 metre depth, were estimated to be 738 ±119,439± 72, and 823 ± 138 Mg C ha −1, respectively. Linear regression models showed the relationship between distance from ocean and C stocks was significant in mangroves and saltmarsh (p≤ 0.001 and p < 0.01, respectively), with the exception of mangroves in an urbanised estuary which displayed the inverse. The differences we observed in C stocks in mangroves and saltmarsh, not seagrass, in relation to location within the estuary may have important implications for management actions and ecological processes.

Induced polarization effects in airborne transient electromagnetic data collected in the McMurdo Dry Valleys, Antarctica

SUMMARYAirborne electromagnetics (EM) is a geophysical tool well suited to mapping glacial and hydrogeological structures in polar environments. This non-invasive method offers significant spatial coverage without requiring access to the ground surface, enabling the mapping of geological units to hundreds of metres depth over highly varied terrain. This method shows great potential for large-scale surveys in polar environments, as common targets such as permafrost, ice and brine-rich groundwater systems in these settings can be easily differentiated because of their significant contrasts in electrical properties. This potential was highlighted in a 2011 airborne EM survey in the McMurdo Dry Valleys that mapped the existence of a large-scale regional groundwater system in Taylor Valley. A more comprehensive airborne EM survey was flown in November 2018 to broadly map potential groundwater systems throughout the region. Data collected in this survey displayed significant perturbations from a process called induced polarization (IP), an effect that can greatly limit or prevent traditional EM workflows from producing reliable geological interpretations. Here, we present several examples of observed IP signatures over a range of conditions and detail how workflows explicitly designed to handle IP effects can produce reliable geological interpretations and data fits in these situations. Future polar EM surveys can be expected to encounter strong IP effects given the likely presence of geological materials (e.g. ice and permafrost) that can accentuate the influence of IP.

Measurements of Bicarbonate in Water Containing Ocean-Level Sulfate Using a Simple Multi-Pass Optical Raman System

The concentration of dissolved inorganic carbon in the oceans at depths of a few meters to thousands of meters is a critical parameter for understanding global warming. The concentration is both pH dependent and depth dependent. Current analysis that employs pH meters must account for several other parameters, such as salinity, temperature, pressure, and the dissolved carbon’s form, carbon dioxide, bicarbonate, or carbonate. Recently, Raman spectroscopy has been used to measure these forms directly in water at ~1000 ppm, which is unfortunately insufficient for typical ocean concentrations, such as ~115 ppm bicarbonate near the surface. Here, we employed a simple multi-pass optical system, a flat mirror to reflect the laser back through the sample, and a concave mirror opposite the entrance slit that effectively doubled the laser power and the collected Raman photons, respectively. This multi-pass optical Raman system with a 1.5 W, 532 nm laser was used to measure 30 ppm bicarbonate in water that contained 2650 ppm sulfate to simulate ocean water, a bicarbonate concentration well below that near the ocean surface. Furthermore, spectral analysis employed the bicarbonate C=O symmetric stretch at 1360 cm−1 instead of the C–OH stretch at 1015 cm−1 to avoid the intense, overlapping sulfate SO4 symmetric stretch at 985 cm−1. The calculated standard deviation of ~5 ppm for the described approach suggests that accurate measurement of bicarbonate in situ is possible, which has been, heretofore, either calculated based on pH or measured in a lab.

Lithological control on scour hole formation in the Rhine-Meuse Estuary

River deltas commonly have a heterogeneous substratum of alternating peat, clay and sand deposits. This has important consequences for the river bed development and in particular for scour hole formation. When the substratum consists of an erosion resistant top layer, erosion is retarded. Upon breaking through a resistant top layer and reaching an underlying layer with higher erodibilty, deep scour holes may form within a short amount of time. The unpredictability and fast development of these scour holes makes them difficult to manage, particularly where the stability of dikes and infrastructure is at stake.In this paper we determine how subsurface lithology controls the bed elevation in net incising river branches, particularly focusing on scour hole initiation, growth rate, and direction. For this, the Rhine-Meuse Estuary forms an ideal study site, as over 100 scour holes have been identified in this area, and over 40 years of bed level data and thousands of core descriptions are available. It is shown that the subsurface lithology plays a crucial role in the emergence, shape, and evolution of scour holes. Although most scour holes follow the characteristic exponential development of fast initial growth and slower final growth, strong temporal variations are observed, with sudden growth rates of several meters per year in depth and tens of meters in extent. In addition, we relate the characteristic build-up of the subsurface lithology to specific geometric characteristics of scour holes, like large elongated expanding scour holes or confined scour holes with steep slopes. As river deltas commonly have a heterogeneous substratum and often face channel bed erosion, the observations likely apply to many delta rivers. These findings call for thorough knowledge of the subsurface lithology, as without it, scour hole development is hard to predict and can lead to sudden failures of nearby infrastructure and flood defence works.

Relief and calcium from gypsum as key factors for net inorganic carbon accumulation in soils of a semiarid Mediterranean environment

In semiarid environments, the total inorganic carbon (TIC) in soil may contribute to the total carbon (C) pool more than the total organic C pool (TOC), thus playing a key role in storing atmospheric CO2. However, due to the different origin pathways of soil carbonates, not all of the TIC pool can be accounted for CO2 sequestration. Indeed, the inorganic C can be accounted for a net sink of CO2 only when calcium (Ca2+) forming carbonates originate from non-carbonate minerals (atmogenic inorganic C, AIC). The aim of this study carried out in a gypsiferous area is to investigate the dissolution of Ca2+ that comes from gypsum (CaSO4·2H2O) in the formation of soil atmogenic carbonates and to quantify the different forms of inorganic C pools to understand their role in storing CO2 in comparison to the TOC pool. To this end, five soil profiles were studied along a hillslope in a gypsiferous afforested area. Soil samples were analysed to determine their main chemical properties, as well as Ca2+, Sr2+, and the 87/86Sr isotopes ratios in different soil fractions. Ca2+ that comes from gypsum, which contributes to the formation of atmogenic carbonates, ranged from 0% to 63%; the remaining percentage resulted from the parent material or other sources (e.g., aeolian dust). The distribution of Ca2+ in soils depended on the relief and the distance of the soils from gypsum outcrops. The accumulation of AIC in soil developed on Holocene deposits reached a maximum accumulation of 16 kg m−3 in the first meter of depth. The average Sr2+/Ca2+ ratio in primary carbonates was 0.333, whereas it was 0.192 in secondary carbonates, thus suggesting that different sources contribute to Ca2+ in both carbonate types. Consequently, the Sr2+/Ca2+ ratio of soil carbonates could be a useful indicator of the presence of secondary carbonates. Overall, results suggest that gypsum plays a key role in the net accumulation of inorganic C in the soil, contributing to store atmospheric CO2. Finally, considering that the AIC pool was lower than the organic C pool, the latter was by far the most important element in fixing atmospheric CO2 in the soils of the semiarid Mediterranean environment that were surveyed.

Near-surface real-time seismic imaging using parsimonious interferometry

Results are presented for real-time seismic imaging of subsurface fluid flow by parsimonious refraction and surface-wave interferometry. Each subsurface velocity image inverted from time-lapse seismic data only requires several minutes of recording time, which is less than the time-scale of the fluid-induced changes in the rock properties. In this sense this is real-time imaging. The images are P-velocity tomograms inverted from the first-arrival times and the S-velocity tomograms inverted from dispersion curves. Compared to conventional seismic imaging, parsimonious interferometry reduces the recording time and increases the temporal resolution of time-lapse seismic images by more than an order-of-magnitude. In our seismic experiment, we recorded 90 sparse data sets over 4.5 h while injecting 12-tons of water into a sand dune. Results show that the percolation of water is mostly along layered boundaries down to a depth of a few meters, which is consistent with our 3D computational fluid flow simulations and laboratory experiments. The significance of parsimonious interferometry is that it provides more than an order-of-magnitude increase of temporal resolution in time-lapse seismic imaging. We believe that real-time seismic imaging will have important applications for non-destructive characterization in environmental, biomedical, and subsurface imaging.

Real-Time Outlier Detection Applied to a Doppler Velocity Log Sensor Based on Hybrid Autoencoder and Recurrent Neural Network

This article presents a real-time outlier detection deep-learning (OD-DL)-based method using a hybridized artificial neural network (ANN) approach. We propose an unsupervised ANN scheme that runs in parallel, a denoising autoencoder (DAE) and a recurrent neural network (RNN). The DAE aims to reconstruct relevant/normal input data, whereas it seeks to ignore outliers; the RNN, with a recursive structure, is used to predict time-series data. As measurements arrive, two tasks are performed: 1) the outlier decision, which is based on a reconstruction error and an energy score criteria from the output difference between the DAE and the RNN; and 2) the training procedure for both DAE and RNN. The proposed OD-DL scheme is specifically targeted to address the outlier problem of the data generated by a Doppler velocity log (DVL) sensor installed on board of an autonomous underwater vehicle (AUV) to enhance the AUV navigation system performance. In particular, the DVL data enter into the OD-DL scheme whose output is fed into an AUV navigation system that runs an error-state Kalman filter that integrates the corrected DVL data with the measurements of an inertial measurement unit and a depth meter. The experimental results show that the AUV navigation system with the OD-DL method outperforms in terms of a more accurate estimated position when compared with the case that there is no outlier detection and with the case of a navigation system using a conventional outlier detection method, or other simpler deep-learning methods.

Study on System Design and Integration of Variable Buoyancy Systems for Underwater Operation

This paper presents the design and analysis of the ‘Variable Buoyancy System (VBS)’ for depth control which is an essential operation for all underwater vehicles. We use the ‘Water Hydraulic Variable Buoyancy System (WHVBS)’ method to control the buoyancy and discuss details of the system design architecture of various components of VBS. The buoyancy capacity of the developed VBS is five kilograms and the performance of the VBS in standalone mode is analysed using numerical simulation. Presented VBS is operable to control the buoyancy up to sixty meters of depth and it can be directly installed to medium size UVs. Simulation results show that the developed VBS can reduce the energy consumption significantly and higher in each cycle (i.e. descending and ascending) of the same VBS in standalone mode being operated with either propeller or thruster for sixty meters depth of operation. Our results conclude and demonstrate that the designed VBS is effective in changing the buoyancy and controlling the heave velocity efficiently and this serves the purpose of higher endurance and better performances desired in rescue/attack operations related to the UVs both in civilian and defense domains.

Numerical modelling for a simplified bridge pier model under high-speed train passage over the bridge

In this work, we simplify a moving high-speed train as combination of a series of the axe loads from the front and rear bogies of cars. We build a simplified bridge pier model, as a result, train source expressions with cars moving on land and bridges are given respectively. Considering that the piers are inserted into the ground at a depth of a few tens meters and reach the bedrock. When the high-speed train passes the piers, the piers will appear oscillating motion which is subjugated by the ground, and this oscillating motion is relative to the microstructure interactions of subsoil and bedrock in the frame of the generalized continuum mechanics theory. Hence, we derive the elastic wave equations based on the modified couple stress theory to perform numerical modelling for a simplified bridge pier model under high-speed train passage over the bridge. Based on the wave equation and the train source expressions, a theoretical seismogram of a moving high-speed train with 16 cars on the bridge are obtained. Compared with the real data recorded when a high-speed train passed the piers in Dingxing County, some conclusions are drawn.