Wet Clay Research Articles

Development and performance evaluation of a wet-resistant strip-till seeder for sowing wheat following rice

Seedling establishment is critical for grain yield and net benefits of wheat in wet clay soil after puddled rice harvest in the Yangtze River basin (YRB) of China. A wet-resistant rotary strip-till seeder (WR seeder) was developed to drill seeds in zero tillage (ZT) conditions with complete rice residue mulching. The rotary blades adopted were medium radius C type blades creating a 50–60 mm wide and 30–50 mm deep furrow for seed placement. The pressing roller, usually used in the traditional wheat seeders, has been replaced by two ground wheels covered in rubber to reduce the mud adhesion. Moreover, a stainless-steel chain was installed behind the machine for better seed covering with soil. Based on three-year long field comparisons with the traditional deep tillage seeder (DT seeder) and a rototiller disc-type seeder with shallow tillage (SHT seeder), the six-row WR seeder significantly enhanced seedling establishment, and reduced energy consumption by 51.3% and 24.5%, respectively. The WR seeder also conserved the topsoil moisture. Over three years, the WR seeder produced similar grain yield to the SHT seeder, but 3.1% more than the DT seeder. Moreover, the net profit with WR seeder increased by 39.4% and 0.9% compared to the DT and SHT seeders, respectively. Furthermore, comparisons across the YRB also confirmed the positive effects of the WR seeder on grain yield and economic benefits over the conventional seeding practices. Thus, it was demonstrated that the improved seeder is an optimal option to enhance the RW system productivity in the YRB. • A strip-till seeder was developed for wheat sowing in wet clay fields. • Yield superiority and energy efficiency with the improved seeder were demonstrated. • The wheat yield increase resulted from the large increase in fertile spikes. • Effective residue management enhances the seeder performance.

Digital Assyriology—Advances in Visual Cuneiform Analysis

Cuneiform tablets appertain to the oldest textual artifacts used for more than three millennia and are comparable in amount and relevance to texts written in Latin or ancient Greek. These tablets are typically found in the Middle East and were written by imprinting wedge-shaped impressions into wet clay. There is an increasing demand in the Digital Humanities domain for handwriting recognition, i.e., machine reading of handwritten script, focusing on historic documents. Current practice in text analysis of cuneiform script relies heavily on transliteration and translation, which are incomplete and influenced by the knowledge and experience of the expert that created them. The development of computational tools for cuneiform analysis presents many opportunities. An efficient and accurate sign spotting enables cross-referencing and statistical analyzes that are infeasible to perform manually. Furthermore, a wedge constellation spotting tool, provides experts with a significantly broader base of references to create more accurate and less time consuming transliterations and translations. Yet, cuneiform script has since resisted efforts to computational processing on basis of its basic constituents, its 3D wedge-shaped impressions and their free-form arrangements into signs. In this work, we review the literature on computational processing and recognition in the domain of cuneiform script. We introduce the different heterogeneous sources of cuneiform script, namely, manual ink-on-paper drawings, digital vector graphics drawings, photographs, and 3D scans of tablets. We describe the development of methods, beginning with the first computational classification using a hybrid manual encoding and computational comparison, to the latest methods making use of Generative Adversarial Neural Networks to recognize characters automatically. Finally, we give an overview of applications of these methods that enable quantitative mining in the small, e.g., patterns of wedge constellations, and in the large, e.g., networks of economic activity.

Void filling and water sealing in a decline in the Kalahari Manganese Field

Investigations were conducted to determine the condition and stability of the existing decline at a mine in the Kalahari Manganese Field, Northern Cape Province, South Africa. During the inspection of the decline, voids were identified behind the concrete lining on the hangingwall and sidewalls over a total linear distance of 230 m. The voids did not provide confinement and, as a result, self-mining was occurring behind the lining. Water was flowing into the decline, over a total linear distance of 100 m, at areas where the decline intersected incompetent rock units, causing softening of the concrete lining and deterioration of the surrounding rock mass. Further damage to the concrete lining was caused by expansion and contraction of the wet red clay unit. Remedial work comprised void filling and water sealing to prevent further deterioration of the decline and ensure that it remained operable for the remainder of the life of mine. Void filling was accomplished by drilling rows of holes along the decline to access the voids and filling the voids with foam. This was followed by the sealing with polymer fluids. Telescopic pipes were also installed to allow water to drain off. A visual inspection was conducted and check-holes were drilled to assess the quality of the remedial work. The void filling material had penetrated cracks in the concrete lining, and areas where voids were intersected by check-holes were re-filled. Additional holes were drilled to re-seal areas that were still wet. The remedial work was completed successfully, as all voids were filled and stability achieved without compromising the concrete lining. The ingress of groundwater was also reduced to some residual dampness.

Calculation of the permittivity of inhomogeneous media based on the TEDAWT method

In the field of nondestructive inspection, ground-penetrating radar (GPR) is a widely used investigation tool, usually to evaluate quality and safety in structural engineering. However, its development has been limited due to differences in the dielectric constant in inhomogeneous media. In this study, a time-energy density analysis of wavelet transform (TEDAWT) method for GPR signal singularity recognition was proposed. In addition, a biorthogonal wavelet basis with high similarity to GPR signal waveform was innovatively constructed and added into the wavelet toolbox. A model experiment was conducted to validate the feasibility of inverse calculation of the permittivity of wet clay by the TEDAWT method. Results showed that this method offered the advantages of signal denoising, resolution improvement, singularity recognition in GPR signal processing. Subsequently, a basic flow chart was established, which could be used to inversely calculate the permittivity of inhomogeneous media, and be applied to the quantitative identification of the thickness of the reinforcement protective layer in an expressway tunnel. The calculation results showed that the inverse calculation value of reinforcement protection layer thickness was 3.74% lower than the average relative theoretical error value. That improved detection accuracy provided a new method to quantitatively identify inhomogeneous media by GPR.

Statistical optimization of the elaboration of ceramic membrane support using Plackett-Burman and response surface methodology

The effect of Sintering temperature (ST), Particle size (PS), Starch content (SC) and Heating rate (HR) of the Ceramic Support Membrane Elaboration based on wet clay were evaluated using Plackett-Burman Design (PBD) and investigated by porosity and mechanical strength measures. Response Surface Methodology based on Central Composite design (CCD) was used for further optimization. The supports have been prepared from a clay with a two fraction 2 and 30 µm and a starch to enhance the performance of the support. The supports sintered between 900 °C and 1200 °C with a different heating rate (1 °C/min and 10 °C/min). By using PBD, it was found that the sintering temperature (ST) and starch content (SC) are the main controlling factors of the physical properties of ceramic support membrane. The increase of ST had a positive effect on Mechanical strength and negative effect on porosity, on other hand the increase of SC had a positive effect on porosity and negative effect on Mechanical Strength. The optimal factors to elaborate the membrane support by using CCD include a sintering temperature of 1014.36 °C and starch content of 4% predicting the porosity of 38.79% and Mechanical strength of 12 MPa.

How big can a walking fish be? A theoretical inference based on observations on four land-dwelling fish genera of South Vietnam.

Comparative study of terrestrial locomotion of 4 fish genera including Anabas, Channa, Clarias, and Monopterus, was performed in experimental setting with the substrate surface of wet clay. No special adaptations for terrestrial locomotion were found. Every fish uses for propulsion on land what it already has. Eel-shaped Monopterus crawls by body undulations in a serpentine or sidewinding technique, the latter of which was not previously observed beyond snakes. The other 3 fish genera walk by body oscillations using stiff appendages as propulsors. When they are located anteriorly, as the serrate operculum in Anabas and the preaxial spine of the pectoral fin in Clarias, the propulsion is termed prolocomotor, when posteriorly, as the spiny anal fin in Channa-metalocomotor. Channa is the heaviest fish walking out of water in our days, quite comparable in size with first Devonian tetrapods Acanthostega and Tulerpeton. A theoretical calculation is suggested for the upper size limit of a fish capable of terrestrial walking without special locomotor adaptations. It should be roughly 20 cm in the vertical dimension of the trunk, which is just a little above the known size of Devonian tetrapodomorph fishes Panderichthys and Elpistostege. The metalocomotor walking technique of Channa is suggested as the closest extant model for terrestrial locomotion at the fish-tetrapod transition. The major difference is that the metalocomotor propulsor in Channa is represented by the anal fin, while in tetrapodomorphs by the pelvic fins. The sprawled pelvic fins were advantageous in respect of reduced requirement for side-to-side tail swinging.

Ultrasonic S-wave responses of single rock joints filled with wet bentonite clay

Clay minerals are prevalent in rock discontinuities and have significant effects on mechanical, hydraulic and seismic properties of rock masses. Understanding seismic behaviours across individual clay-rich rock joints is of great importance in the fields of geology and earth sciences. However, the wave responses of individual clay-rich rock joints have not been well understood until now. This paper reports a laboratory investigation of ultrasonic S-wave propagation and attenuation across single rock joints filled with bentonite clays with varying degree of water saturation. In this study, a series of acoustic measurements were conducted on specimens of the bentonite clay-filled rock joint using a self-developed ultrasonic pulse-transmission test system that equipped with a S-wave transducer pair with a dominant frequency of 250 kHz. Based on the obtained laboratory data, the wave velocity, transmission ratio and the time-frequency-energy distribution of the S-waves transmitted through the bentonite clay-filled joint were calculated and evaluated. The experimental results show that the degree of water saturation of the bentonite clay greatly affects S-wave responses of the filled rock joint. In particular, an increase in the degree of saturation causes a nonlinear decrease in S-wave velocity. In addition, as the water saturation of the bentonite clay increases, the wave attenuation decreases; the minimum wave attenuation is reached at a saturation degree of 71.4% and then the attenuation increases slightly. Additionally, with the increase of the water saturation, the magnitudes of the S-wave energy transmitted across the bentonite clay-filled joint firstly increases and then decreases. The S-wave energy is mostly stored in the frequency range of 150 - 300 kHz regardless of the degree of water saturation of the bentonite clay. This finding indicates that the frequency partition of the transmitted S-waves rarely changes with the changing water saturation. The present work could not only compensate for the lack of laboratory-based research on wave behaviours across clay-rich rock joints but also provides insights into the interpretation of acoustic data from field tests for detecting, characterizing and monitoring rock discontinuities.

Finite Element Method Analysis Applied to Different Foundations Structures Systems

In the conventional static analysis of building frames, the base is idealised on rigid supports and the building is subdivided into three parts namely, the superstructure, the foundation and the ground soil, before design. In real life situations, the soil underneath the building undergoes deformations which may alter the performance of the structure. In this paper, it is studied the effect of soil type and foundation type on the response of a building frame system with both fixed base and flexible base. The Winkler model of soil-structure interaction is adopted to study the influence of soil flexibility and foundation rigidity on a 4 storey RC building with a regular plan resting on three types of soils namely, the light peat marshy ground, wet clay and medium gravel with fine sand. Three types of foundations are considered in the study: isolated footings, tied foundation and the raft (with and without overhangs) foundations. Winkler model is developed using springs by Finite Element Method in SAP2000. The settlement, the bending moment, the shear force and the axial force are the parameters placed forth for the comparative study. Results obtained reveal an increase in the response of the structure with respect to the soil flexibility and foundation rigidity.

Performance assessment of a newly developed and highly stable grouting material for a completely weathered granite dam foundation

Grouting is one of the most important techniques in anti-seepage and reinforcements of sandy soil dam foundations. However, there is a lack of stable grouting materials as the existing materials show many limitations. This paper proposed a new grouting material to improve the anti-seepage and mechanical performance of completely weathered granite. This grout of desirable groutability, stability, and strength was produced by wet grinding clay cement slurry. The effects of different clay contents and water–solid ratios on the engineering properties of the grouting material and the formation mechanism of the slurry were studied through a series of laboratory experiments. The optimal formulations of the grout were determined by comparing the engineering performance of the new grout with of the superfine cement slurry and the wet-ground fine cement slurry. The recommended parameters for the new grout included a specific gravity of 1.15 for the clay slurry and a water–solid ratio of 1.0 (the mass proportions of clay and cement to the total solids are 25% and 75%, respectively). Finally, a grouting simulation experiment and a field grouting test were conducted to verify the groutability and effectiveness of the proposed grouting material. The results indicate that the grout is an economical and environmentally friendly grouting material with good groutability.

Analysis of Adhesion between Wet Clay Soil and Rotary Tillage Part in Paddy Field Based on Discrete Element Method

To analyze the process of wet clay soil adhering to the rotary tillage part during rotary tillage in paddy field, simulation tests were carried out based on the discrete element method (DEM) in this study. The Plackett-Burman (PB) test was applied to obtain simulation parameters that significantly affected the soil adhesion mass. The Box-Behnken design (BBD) based on the principle of response surface method (RSM) was used to establish a regression model between significant parameters and soil adhesion mass. The soil adhesion mass obtained from the actual soil bin test as the response value was brought into the regression model. The optimal simulation parameters were obtained: the particle-particle coefficient of rolling friction, the particle-geometry coefficient of static friction, and the particle-particle JKR (Johnson-Kendall-Roberts) surface energy were 0.09, 0.81, and 61.55 J·m−2, respectively. The reliability of the parameters was verified by comparing the soil adhesion mass obtained under the optimal simulation parameters with the actual test value, and the relative error was 1.84%. Analysis of the rotary tillage showed that soil adhesion was mainly concentrated in the sidelong section of the rotary blade. The maximum number of upper soil particles adhering to the rotary tillage part was 2605 compared to the middle soil and lower soil layers. The longer the distance the rotary tillage part was operated in the soil for, the more soil particles would adhere to it. This study can provide a reference for the rational selection of simulation parameters for rotary tillage and the analysis of soil adhesion process in rotary tillage.

MORPHOLOGICAL VARIABILITY OFCICONIA BOYCIANA(AVES: CICONIIDAE) TRACKS IN HOMOGENEOUS SEDIMENT

ABSTRACTThe morphological variability of Ciconia boyciana (oriental white stork) tracks is documented in an actualistic ichnological experiment using wet potter's clay. Measurements were obtained from 54 tracks left by two individuals comprising area, length, width, depth, volume, and rotation for each track. The trackmakers were also filmed while walking. An anatomical feature unique to C. boyciana is that, unlike other wading birds, it does not leave metatarsophalangeal pad impressions. This feature can be used to distinguish C. boyciana tracks from those left by other birds of similar body weight and habitat. Track width varied by up to 30%, with wider tracks showing more splayed digits occurring in trackways with shorter stride length and larger trackway width. Conversely, narrow trackways with a large stride length were composed of tracks with a smaller digit divarication. Coefficient analysis of track geometry revealed that the widths and depths of tracks vary inversely to maintain a consistent volume. Sorting the C. boyciana tracks into morphological types (14 types for avians with four digits) demonstrates the result that most tracks are deeper between digits III and IV than between digits II and III. Combining track data with video footage shows that C. boyciana moves its hips from side to side while walking. Noting that the tracks within any given trackway are outwardly rotated, we interpret this track morphology as resulting from laterally directed pressure exerted primarily through digit IV.

Gene expression of microbial gelatinase activity for porcine gelatine identification

In order to invent a porcine gelatine detection device using microbial resources, bacterial enzymes with a preference towards porcine gelatine and their candidate genes were evaluated. Five (n = 5) bacterial strains isolated from hot spring water and wet clay, Malaysia were screened for their gelatinase activity. The gelatinase enzyme was extracted and purified using ammonium sulphate precipitation prior to performing gelatinase assay on porcine, bovine and fish gelatine medium substrates. The G2 strain or Enterobacter aerogenes (Strain EA1) was selected for whole genome sequenced after showing a consistent trend of preference towards porcine gelatine. The gelatinase candidate gene gelEA1_9 was cloned and expressed. Based on one-way analysis of variance (ANOVA) with POST-HOC Duncan test (α = 0.05), the final product of gelEA1_9 was identified as a novel gelatinase. This gelatinase presented no significant difference in activity towards porcine gelatine. Hence, the present study demonstrated an enzyme-substrate interaction for porcine gelatine identification.

Investigation of attapulgite clay crushing by bionic tooth plates inspired from convex structures on body surface of dung beetles

A bioinspired tooth plate structures imitating convex structures on the head and body surfaces of dung beetles was presented and analysed using the discrete element method. Simulation results showed that compared with the regular tooth plates without bionic structures, the bionic crushing tooth plate offers a better performance and higher efficiency in crushing wet attapulgite clay. Based on the simulation results, a two-stage crushing machine was designed, produced, and validated through experiments. Experimental results confirmed that the developed crushing equipment with the bioinspired convex structures can effectively crush the attapulgite clay with high moisture content, which cannot be crushed by existing crushers due to the adhesion of the wet clay particles to the tooth plate surfaces. The produced crushing equipment has been applied for processing the attapulgite clay in China, and the design idea can be applied to develop other equipment for crushing rare earth minerals with high moisture content.

Hydrate formation from clay bound water for CO2 storage

Geological storage of CO2 in form of hydrate in marine sediments is an alternative option to mitigate global warming. Clay is one of the most dominant lithology in marine sediments, which has higher water adsorption capacity than sand. In this work, the formation of CO2 hydrate from clay bound water was experimentally investigated by using low-field NMR. The effects of mineral, water content and pressure on the capacity of CO2 storage were analyzed. With the increase of water content, there was a transition of CO2 storage from adsorption on the montmorillonite surface to hydrate formation. The strongly bound water competed with CO2 gas for the adsorption sites on the surface of montmorillonite when the water content was below 15%. Afterwards, CO2 hydrate formation started due to the availability of weakly bound water. The storage of CO2 in hydrate in illite increased continuously with the increase of water content in the range of 5% to 20% due to the low level of strongly bound water. During hydrate formation, the peak position of T2 distribution spectra of the wet clay shifted to the left, indicating an ordered conversion of weakly bound water to hydrate from the outer layer to the inner layer of diffuse double layer. The final amount of CO2 hydrate formed from weakly bound water increased with the elevated pressure due to the variation of activity of the bound water in diffuse double layer. These results will not only broaden the understanding of gas hydrate in clay bound water systems but also promote a new evaluation of the safety and potential of CO2 hydrate storage in clayey sediments.

OBSTETRIC GYNECOLOGICAL SOCIETY IN BERLIN
 Meeting December 11, 1891

Brse demonstrated a new vaginal electrode that he made for such electrical applications where one wishes to take advantage of the pole-to-pole current. The electrode consists of a clay cylinder with a circumference of 9 cm, which is inserted into the vagina in exactly the same way as a tubular mirror. In this clay cylinder is placed a metal cylinder, equipped with numerous holes, which has a screw at its outer end to strengthen the conductor. After the introduction of the clay cylinder, a metal cylinder is inserted into the vagina, and the clay tube is filled with warm water. The wet clay cylinder is an excellent conductor of current and replaces the skin electrode made from a sponge. If this cylinder is inserted into the vagina for a length of 8-10 cm, then with a circumference of 9 cm, it will correspond to a flat electrode of 72-90 sq. Cm. This electrode is intended for use where one wants to concentrate the current density in more than one place of the vagina. but evenly distribute the current over the pelvic organs. It is used more where, when using strong galvanic currents, they want to avoid the cauterizing effect on the vaginal mucosa, which easily occurs when spherical electrodes are used, despite being wrapped in cotton wool. Finally, it is used where one wants to obtain an interpolar (so-called catalytic) effect. The patient, when using this electrode, tolerates perfectly well currents of 80-100 MA, while cauterization of the vaginal mucosa is not obtained.

Thermal infrared imaging based breast cancer diagnosis using machine learning techniques

The human’s temperature is little known and important to the diagnosis of diseases, according to most researchers and health workers.In ancient medicine, doctors may treat patients with wet mud or slurry clay. The part that would dry up first was considered the diseased part when either of these spread over the body. This can be done today with thermal cameras generating pictures with electromagnetic frequencies. Inflammation and blockage areas that predict cancer without radiation or touch may be detected by thermography. It can be used before any visible symptoms occur as a great advantage in medical testing. Machine learning (ML) is used in this paper as statistical techniques to give software programs the capacity to learn from information without being directly coded. ML can help to do so by learning these thermal scans and identifying suspected areas where a doctor needs to research more. Thermal photography is a comparatively better alternative to other methods that need sophisticated equipment, enabling machines to provide an easier and more effective approach to clinics and hospitals.

Modelling of Natural Convective Heating of a Standard Wet Brick for Oven Energy Consumption Tests

The environmental impact of buildings is directly influenced by low-efficiency appliances like electric ovens. Their energy class is estimated through a test prescribed by the EN 60350 European standard, where a wet clay brick is heated under set conditions and the energy consumption is measured; throughout the test, particular attention is devoted to the control of air temperature. In this work, a transient model of the oven suitable for control design was realized including the heat and mass transfer within the brick. A lumped-parameter approach was used to ensure good predictive properties and low computational cost. The dynamics of the cavity air and the Pt500, which is used in normal operation to maintain the desired set point, was also included in the model. Model parameters were determined through an optimization procedure based on the experimental data collected during energy consumption tests with the oven in natural convective heating mode. The model was then validated. Good results were obtained in the prediction of both temperature and heating time.

Study on the C0–Cw relationship of clay-bearing sandstones based on digital cores

Based on the three-dimensional digital core of Berea sandstone, three-phase (matrix, wet clay and free water) digital cores of clay-bearing sandstone are constructed. We divide clay into structural clay and dispersed clay according to the location where clay growth occurs. The finite-element method is used to simulate the electrical characteristics of digital cores in order to study the relationship between the conductivity of core saturated with brine (C0) and the brine conductivity (Cw). The influence of clay mineral type, content and porosity on core electrical characteristics is taken into account. The results show that the additional conductivity is related to the clay minerals, and montmorillonite has the highest cation exchange capacity, resulting in the largest additional conductivity. The increase in clay content in cores increases the conductivity of core C0. At the same time, clay that fills pores decreases the porosity and causes the decrease in C0. These are two opposing factors of conductivity that coexist in clay-bearing sandstone.

Applying Phenomenological Lumped Models in Drying Process of Hollow Ceramic Materials

Drying is a complex process of coupledheat and mass transfer of wet porous material. Wet clay products when exposed to drying without control can suffer cracks and deformations, reducing its quality post-drying. Thus, this work aims to study the hollow ceramic materials drying with arbitrary shape using lumped models. Here, the exact solution of the governing equations were obtained using the method of separation of variables. Results of the average moisture constant and temperature of the material along the process are presented and analyzed. It was observed that the moisture loss process occurs at a lower speed than the heating of the ceramic material because its thermal diffusivity is greater than the mass diffusivity and that the area/volume relationship strongly affects the heat and mass transfer of the material.

Optimization of adobe clay bricks based on the raw material properties (mathematical analysis)

This research studies the effects of composition and granulometry analysis of 139 heavy clays on the important characteristics of wet and adobe clay bricks. ANN models were obtained with high prediction accuracy in training cycles (r2): 0.580–0.907. Standard score analysis (SS) is performed to evaluate the optimal content of raw materials to gain adobe bricks. Optimal macro-oxides content was 53–66% SiO2, 4.6–7.5% Fe2O3, 12.5–18.2% Al2O3, 0.9–8.8% CaO, 1.2–3.6% MgO. The optimal quantity of alevrolite-sized particles varied between 46 and 65%, and clay-sized particles contents ranged from 20.4 to 40.6%.