Penetrating Time Research Articles

Design and Verification of a Penetration System Used for Constructing the Sampling Channel

Based on the analysis of the water ice sampling system design at the lunar permanent shadow region(PSR), a rapid sampling channel construction method based on kinetic energy penetration was proposed, and an engineering prototype of the penetrator system based on the conversion of chemical energy and kinetic energy was developed, which can solve the problem that the subsurface lunar water ice is too difficult to sample quickly due to its significantly enhanced mechanical properties. Based on the mechanical properties boundary of lunar soil water ice, the performance of the engineering prototype was tested and verified. The test results show that the penetrating system developed in this paper can achieve rapid penetration into the lunar soil with uniaxial compressive strength of about 30MPa without consuming power consumption; the penetrating depth can reach 234mm, and the penetrating time is less than 1s. The penetrating system can rapidly construct sampling channels, which can effectively solve the problem of the high-hardness water ice samples located at the subsurface layer of the lunar soil that can be efficiently exposed faced by in-situ water ice sampling in the permanent shadow region.

Key Factors for Deep Cement Mixing Construction for Undredged Offshore Land Reclamation

Deep cement mixing (DCM) is an environmentally friendly technique for offshore ground improvement without dredging or much disturbance to the marine ecological system. Several field construction factors can influence the unconfined compressive strength (UCS) of cement-stabilized soil. In this study, key construction factors are evaluated referring to site investigation records, construction records, and quality test results of a large offshore DCM construction project. The key factors were attributed to geological conditions, construction procedures, and curing conditions. Specific field construction factors include fluctuations of tidal level, original soil type, volume fraction of injected water, volume fraction of injected cement slurry, injection rate of cement slurry, penetrating and mixing time per meter, curing age, and moisture content. The importance of these construction factors on the DCM strength has been quantified using a statistical method based on construction records. The injected water volume and original soil type are noted to be the two most dominant factors on the UCS of the treated soils. Longer mixing time improved the strength of the treated soils.

Modified Camellia oleifera Shell Carbon with Enhanced Performance for the Adsorption of Cooking Fumes.

Using Camellia oleifera shell (COS) as a raw material and phosphoric acid as the activator, activated Camellia oleifera shell carbon (COSC-0) was prepared and then modified by Fenton’s reagent (named as COSC-1). SEM, GC-MS, FTIR, and specific surface area and pore analyzers were used to study the adsorption performance of COS, COSC-0, and COSC-1 on cooking fumes. Results showed that COSC-1 was the best adsorbent compared with COS and COSC-0. The adsorption quantity and penetrating time of COSC-1 were 44.04 mg/g and 4.1 h, respectively. Most aldehydes could be adsorbed by COSC-1, which was due to the large number of carbonyl and carboxyl groups generated on the surface of COSC-1 from the action of Fenton’s reagent. The adsorption effect of COSC-1 on different types of pollutants in cooking fumes was analyzed based on the similar compatibility principle. COSC-1 showed a much higher adsorption effect on the strong polarity functional groups than on weak polar groups. The results provide a theoretical basis for the application of Camellia oleifera shell carbon adsorption technology in the treatment of cooking fumes.

Concus Finn Capillary driven fast viscous oil-spills removal by superhydrophobic cruciate polyester fibers

Developing functional materials integrating multi-tasking oil/water separation performances is significant but challenging for the remediation of large-scale oil spills causing pernicious environmental damages. Herein, a novel Concus Finn Capillary driven oil sorbent (OSCPF) fabricated by aligning superhydrophobic cruciate polyester fibers based on yarn spinning mechanism is designed to realize the clean-up of oil spills and various oil/water mixtures at high speeds. Instantaneous oil diffusion is achieved by abrupt Concus Finn Capillary driven oil-flows along aligned channels. This advance reduces the penetrating time for viscous crude oils by 95.00% comparing with that of non-oriented circular polyester fibers. The OSCPF possess great oil sorption capacity of 54.36–124.71 g/g and can separate oils from immiscible oil/water mixtures, including seawater, soap-water, CuCl2-water, and KMnO4-water, and surfactant-stabilized O/W emulsions by the way of adsorption with satisfactory separation efficiency (99.41–99.83%). Especially, the OSCPF is effectively used to enclose oil spills to prevent rapid oil diffusion and in-situ continuously collect the spillages from water surface and underwater by pumping device with recovery rates of 15,727–104,227 L·m−2·h−1. Considering the unique structural design, fast oil sorption speed, and low operating cost, this work provides a prospective oil remover addressing the remediation of catastrophic multi-tasking oil/water pollutions.

A Survey Method on Groundwater Sources and Preferential Flow Paths In Urban Limestone-Based Residential Districts

Residential districts dominated by limestone are likely to be impacted by undesirable groundwater seepage accidents. Such groundwater seepage can generally give rise to loss of life and property. To control groundwater seepage, increasingly accurate and reliable methods for surveying are becoming indispensable. We proposed a survey method to confirm groundwater sources and preferential flow paths in urban limestone-based residential districts via ground penetrating radar (GPR) and time domain electromagnetic method (TDEM). Firstly, we established the geophysical exploration plan after careful analysis of available hydrogeological survey data including terrain, stratum distribution and water table. Survey lines were designed parallel to existing urban roads and perpendicular to the ground. Next, we used GPR and TDEM to detect gravels in the permeable layer and water-rich regions in the aquifer. Drilling method was adopted for comparisons to resulting images. Finally, integrated interpretation indicated accurate measures of groundwater sources, main preferential flow paths and the preliminary classification of groundwater leakage risk in a study region. The feasibility and effectiveness of the GPR and TDEM survey method were verified in the hydrogeological survey at the Lingxiucheng Residential District in China, where a thick limestone layer existed and groundwater leakage accidents had occurred in basements of houses. The method had high reliability for limestone topographies and was improved to be an effective and low-cost solution to overcome physical limitations of existent buildings and traffic jams in urban areas. Therefore, our research can be extended to similar projects and related problems to help better map urban limestone-based residential districts and reduce groundwater seepage.

Comparison of soil water content estimation equations using ground penetrating radar

Soil water content has an important impact on many fundamental biophysical processes. The quantification of soil water content is necessary for different applications, ranging from large-scale calibration of global-scale climate models to field and catchment scale monitoring in hydrology and agriculture. Many techniques are available today for measuring soil water content, ranging from point scale soil water content sensors to global scale, active and passive, microwave satellites. Geophysical methods are important methods, used for several decades, to measure soil water content at different scales. Among these methods, ground penetrating radar has been shown to be one of the most reliable and promising ones. Soil water content measurement using ground penetrating radar requires the application of parametric equations that will convert the measured dielectric permittivity to water content. While several studies have been performed to test equations for soil water content sensors such as time domain reflectometry, a few studies have been performed to test different formulae for application to ground penetrating radar. In this study, we compare available formulae for converting dielectric permittivity obtained from detailed laboratory scale measurement of reflected waves using ground penetrating radar. Four soils covering a wide range of textures were used and the measured soil water contents were compared with values obtained from gravimetric measurements. Results showed that the dielectric mixing model of Roth et al. (1990) provided the best fit for individual soil textural classes, except for sandy soils. However, for all data combined the dielectric mixing model performed much better with significant difference in coefficient and determination and root mean square error. Empirical equations developed from calibration of time domain reflectometry performed poorly when applied to estimation of soil water content obtained from ground penetrating radar. Differences in sample volume, frequency of operation and data analysis between ground penetrating radar and time domain reflectometry, suggest to use more flexible and robust electromagnetic mixing formulae, allowing for incorporating the dielectric properties of constituents materials and geometrical features of the media. Sensitivity analysis was then performed to provide detailed information for the most accurate application of the selected dielectric model. Sensitivity analysis showed that the geometric parameter α and the dielectric permittivity of the solid phase ∊s are the two most sensitive parameters, determining important variations in the estimation of soil water content. Based on these results, these two parameters are suggested as fitting parameters, to be selected if the model is fitted to data. Otherwise, the model can be successfully used without calibration, as presented in this study, by using α = 0.5 (as also suggested by the authors) and ∊s = 4, which is an average value for soil minerals.

Investigation on the Continuous Wave Mode and the ms Pulse Mode Fiber Laser Drilling Mechanisms of the Carbon Fiber Reinforced Composite.

The near infrared (NIR) laser drilling of a carbon fiber reinforced polymer (CFRP) composite in the continuous wave (CW) mode and the ms pulse mode was investigated by an experiment and a numerical simulation. The relationships between the laser penetrating time, entrance hole diameter, surface heat affected zone (HAZ) width, and material ablation rate and the laser irradiation time and laser peak power densities were obtained from the experiment. For the same average power density of the laser output, 3.5 kW/cm2, it was found that the ms pulse laser mode, which had a higher peak power density, had a higher drilling efficiency. When drilling the same holes, the pulse laser mode, which had the highest peak power density of 49.8 kW/cm2, had the lowest drilling time of 0.23 s and had the smallest surface HAZ width of 0.54 mm. In addition, it was found that the laser penetrating time decreased sharply when the peak power density was higher than 23.4 kW/cm2. After analyzing the internal gas pressure by the numerical simulation, it was considered that a large internal gas pressure appeared, which resulted from polymer pyrolysis, causing a large amount of the mechanical erosion of the composite material to improve the drilling efficiency. Therefore, the ms pulse laser showed its potential and advantage in laser drilling the CFRP composite.

Estimation of ground cavity configurations using ground penetrating radar and time domain reflectometry

Ground cavity configurations, including depth, roof shape, and length, are the main factors affecting the risk of ground sinkholes. In this study, ground penetrating radar and time domain reflectometry are applied to estimate the ground cavity configurations. To accurately estimate ground relative permittivity with depth, a penetrometer incorporated with a time domain reflectometry (PTDR) system is developed. In addition, a new method is established to calculate the coordinates of the reflection points. Experimental studies are conducted on ground models prepared in different soil types with buried objects of various shapes to simulate ground cavities by using circular rubber tubes and rectangular and trapezoidal polystyrene objects. The experimental studies show that the estimated depths of the buried objects are identical to the experimental setup. The estimated roof shapes clearly represent the roof shapes of the buried objects. In addition, the estimated diameters of the rubber tubes and the estimated lengths of the polystyrene objects show good agreement with those of the buried objects. This study shows that the ground penetrating radar survey, PTDR test, and the new method for estimating ground cavity configurations may be effectively used to assess the risk of ground sinkholes.

Blasting type penetrating characteristic in variable polarity plasma arc welding of aluminum alloy of type 5A06

Experiments were carried out in this paper first to clarify the characteristics of a digging process during aluminum alloy of type 5A06 variable polarity plasma arc welding (VPPAW). A special “Blasting type” penetrating phenomenon was observed through measuring the penetrating time by electrical and optical signals. A 3D model was established to numerically investigate heat transfer, fluid flow and surface shape during the digging process. An adaptive heat source was adopted to describe heat transfer process involving deformation of the keyhole tracked by volume-of-fluid (VOF) method. The plasma arc pressure attenuated in a parabolic form as the depth of the keyhole increases. It is found that the weld pool surface becomes concave after sufficient melting of metal. The keyhole depth exhibits responsive changes, which corresponds with the different stages of welding parameters. In the late stage, the depth increase rapidly to fully penetrating state, which shows a “blasting type” penetrating process. The keyhole formation was interpreted by considering energy accumulation and mass conservation of fluid flow. The maximum velocity during digging process always occurs on the keyhole surface, where a vortex in the opposite direction appears inside the weld pool. The calculated penetrating time, keyhole size and fusion line were basically in agreement with the experimental results.

Big Data in Health Care using Frequent Set Extraction

To construct a student healthcare website which is termed as education world and reducing the answer time while bountiful any query towards the database wherever the data are stored. By using this website the consumer can acquire educational related material by queries. In this mission, the website is working to find the available frequent stuff using the procedure called APRIORI. This mission will be valuable in applications wherever the users consuming a set of stuff repeatedly. In order to separate these things from the databank, this process uses APRIORI algorithm. These are the areas where spending the time period to decrease the time using search. The disadvantage of existing scheme is it aimed at each and every demand given through the consumer. It will examine for all records which are not at altogether used and wanted by the consumer. So the total amount of the stuff escalates, the determined time period also escalates which will dynamically escalate the response time which will shrink the concert of the scheme. So the knowledge in which the system is working to the instrument will reduce the reply time in such a condition where the common data are used through the consumers. The system is also refining performance through parallelizing the actions in finding common data items. To shrink the response time period the system is spending the time period to catch the records in the databank. If the penetrating time reduces, mechanically the response period of the consumer query will also reduces. It clues to perform development of the scheme.

Application of Moldflow in Gas-Assisted Injection Molding

Gas-assisted injection molding(GAIM)is a new kind of plastic processing technique. It is one of the most important developments in the injection molding industry. GAIM has many advantages such as lower injection pressure, lower warpage, better surface quality, lower material consumption, and shorten molding cycle time, etc. MPI/Gas module of Moldflow software can be used to simulate the GAIM process to optimize the whole molding process. In this study, the FM new truck interior ceiling handle was analyzed in GAIM process based on the MPI/Gas module. The simulation results showed the gas penetrating time, the contours of plastic layers thickness fraction of the parts and the gas volume fraction changing with time. The results can help technicians to determine the optimum process of the melt injection and the gas injection to ensure the final quality of the parts.

Using ground penetrating radar and time–frequency analysis to characterize construction materials

For decades, applications of nondestructive evaluation-civil engineering (NDE-CE) focus on object identifications (such as steel bars, tendon ducts and backwall reflections) in infrastructures. Because of the advantage of efficient visualization of internal structure, utilization of these methods can probably be extended to material characterization (MC) of aging and adversely exposed infrastructures. However, two factors yield a big gap between NDE and MC. First, for the ease of visualization, the primary focus of NDE-signal processing is object identification, which usually alters the originality of the signal. Second, there is lack of relationship and inverse models bridging the NDE-derived and conventional material properties compared to other disciplines of science, such as geophysics. These disadvantages make laboratory and field-scale NDE-MC still a far-reaching holy grail and is possibly the greatest hurdle to be regularly adopted in CE structures. This paper attempts to address this gap from object identification to MC using ground penetrating radar (GPR) as one of the most frequently used NDE-CE methods, and signal processing with joint time–frequency domain (JTFA) analysis. Three examples of material property characterization regarding the individual effects of steel bar corrosion in concrete, hydration and moisture content distribution of construction materials are given.

Wetting agent investigation for controlling dust of lead-zinc ores

The purpose of this project is to control the pollution of dust, which occurred in a typical lead-zinc mine. Two kinds of surfactants and water glass were chosen as the wetting agents to study the behaviours of suppressing the dust. The performances of the wetting agents of various sizes and water content of dust and their compositions among different weting agents were investigated. Firstly, the chemical compounds, dispersity, water content, bulk density and other relevant physico-chemical properties of the choiced dust of lead-zinc ore were mensurated. A great number of down-ward penetrating tests were conducted to different partical sizes of dust and to analyze the dust wetting behaviour respectively. The optimal compositions of wetting agents were obtained in accordance with different water contents and partical sizes of the dust after analyzing and statisting the achieved experimental data. The data show that the efficiency of chemical dust suppression of weting agents is much better than that of water. The results of the research work prove that the partical size and the water content of the dust are very important factors to the dust suppression. The results are also proved validly by the dropping experiment, which takes the penetrating diameter and penetrating time as the major factors. The superfine dust is much more difficult to be wetted. Since increasing the water content of dust is the best approach to control it, the choice of wetting agents for improving dispensation is significant.

ＬＤ励起ＱスイッチＹＡＧレーザによる超微粒超硬合金の微細穴加工

Machining characteristics and the quality of microboring for fine powder cemented carbide by diode-pumped Q-switched YAG laser irradiation were experimentally investigated in order to obtain microaccurate holes with a high aspect ratio. In general, it is difficult to cut and polish the microhole of a hard material accurately for observing the inside of the machined hole. Therefore, micro-EDM was used as a cutting and polishing method in this study. Evaluation of the sectional surface of the microhole clarified the following facts. The low pulse frequency of laser oscillation led to the reduction of cracks and of the resolidification layer inside the machined hole. The bulge along the inside of the machined hole hardly appeared in thin-workpiece and high-peak-power conditions, in which the penetraction hole could be obtained in a short time. Therefore, it is considered that laser penetrating time was the important factor affecting the formation of the bulge. Laser irradiation consisting of two stages was proposed in order to reduce the laser beam irradiation time per process. In the first pocess, laser irradiation for 1 second was perfomed. Then, in the second process, the laser beam was irradiated after moving the focus point inside the workpiece is two-stage irradiation made it possible to improve the quality of the machined hole.

Monitoring Temporal Development of Spatial Soil Water Content Variation: Comparison of Ground Penetrating Radar and Time Domain Reflectometry

We compare the capability of ground penetrating radar (GPR) and time domain reflectometry (TDR) to assess the temporal development of spatial variation of surface volumetric water content. In the case of GPR, we measured surface water content with the ground wave, which is a direct wave between the sender and receiver through the upper centimeters of the soil. Spatial water content variation was measured on 18 d with GPR and TDR during a 30‐d monitoring period. To ensure large fluctuations in the spatial water content variation, we created a heterogeneous pattern of water content by irrigation on 2 d. The temporal development of the spatial variation was studied by means of the variogram and interpolated water content maps. To compare GPR and TDR variograms, we estimated confidence intervals of the experimental variograms and the variogram model parameters with a jackknife approach and a first‐order approximation of model parameter uncertainty. The results showed that the 95% confidence intervals of the GPR experimental variogram were one to two orders of magnitude smaller than the 95% confidence intervals of the TDR experimental variogram because of the larger number of GPR measurements. Consequently, the uncertainty in the variogram model parameters was also much lower for GPR, which meant that the temporal development of the fitted GPR variogram model parameters was easier to interpret. Furthermore, the larger GPR measurement volume resulted in a low spatial nugget variance of 1 × 10−6to 1 × 10−9(m3m−3)2because short distance variation was averaged. This meant that GPR accurately measured spatial correlation lengths, even in the case of low water content variation. Interpolated maps showing the increase of water content due to irrigation and the subsequent gradual drying of the soil were more accurate and reproducible for GPR. It was concluded that the noninvasive GPR measurements provide the means to accurately and consistently monitor the development of spatial water content variation in time.

Monitoring Temporal Development of Spatial Soil Water Content Variation: Comparison of Ground Penetrating Radar and Time Domain Reflectometry

We compare the capability of ground penetrating radar (GPR) and time domain reflectometry (TDR) to assess the temporal development of spatial variation of surface volumetric water content. In the case of GPR, we measured surface water content with the ground wave, which is a direct wave between the sender and receiver through the upper centimeters of the soil. Spatial water content variation was measured on 18 d with GPR and TDR during a 30-d monitoring period. To ensure large fluctuations in the spatial water content variation, we created a heterogeneous pattern of water content by irrigation on 2 d. The temporal development of the spatial variation was studied by means of the variogram and interpolated water content maps. To compare GPR and TDR variograms, we estimated confidence intervals of the experimental variograms and the variogram model parameters with a jackknife approach and a first-order approximation of model parameter uncertainty. The results showed that the 95% confidence intervals of the GPR experimental variogram were one to two orders of magnitude smaller than the 95% confidence intervals of the TDR experimental variogram because of the larger number of GPR measurements. Consequently, the uncertainty in the variogram model parameters was also much lower for GPR, which meant that the temporal development of the fitted GPR variogram model parameters was easier to interpret. Furthermore, the larger GPR measurement volume resulted in a low spatial nugget variance of 1 × 10−6 to 1 × 10−9 (m3 m−3)2 because short distance variation was averaged. This meant that GPR accurately measured spatial correlation lengths, even in the case of low water content variation. Interpolated maps showing the increase of water content due to irrigation and the subsequent gradual drying of the soil were more accurate and reproducible for GPR. It was concluded that the noninvasive GPR measurements provide the means to accurately and consistently monitor the development of spatial water content variation in time.

Complex Dielectric Permittivity of Soil–Organic Mixtures (20 MHz–1.3 GHz)

The dielectric permittivity of soils can be significantly modified by the presence of organic contaminant in the pore fluid. Thus, nondestructive techniques based on the propagation of electromagnetic waves may be used to detect contaminant plumes and to evaluate decontamination processes. Ground penetrating radar (GPR) and time domain reflectometry are two of the most relevant geophysical tools working in the frequency range of interest here. In this work, the complex dielectric permittivity of some soil–organic mixtures are measured in the frequency range of 20 MHz to 1.3 GHz. Tests are conducted in samples of silica sand, loess, and kaolinite mixed with varied amount of paraffin oil and lubricant oil. Additional tests are performed in soil–water samples for comparison. Mixtures formulas reported in the literature are extended from two to three and four phases in order to model the measured dielectric response of the contaminated soil samples. The results allow us to study the effect of the volumetric l...

Monitoring Temporal Development of Spatial Soil Water Content Variation

We compare the capability of ground penetrating radar (GPR) and time domain reflectometry (TDR) to assess the temporal development of spatial variation of surface volumetric water content. In the case of GPR, we measured surface water content with the ground wave, which is a direct wave between the sender and receiver through the upper centimeters of the soil. Spatial water content variation was measured on 18 d with GPR and TDR during a 30-d monitoring period. To ensure large fluctuations in the spatial water content variation, we created a heterogeneous pattern of water content by irrigation on 2 d. The temporal development of the spatial variation was studied by means of the variogram and interpolated water content maps. To compare GPR and TDR variograms, we estimated confidence intervals of the experimental variograms and the variogram model parameters with a jackknife approach and a first-order approximation of model parameter uncertainty. The results showed that the 95% confidence intervals of the GPR experimental variogram were one to two orders of magnitude smaller than the 95% confidence intervals of the TDR experimental variogram because of the larger number of GPR measurements. Consequently, the uncertainty in the variogram model parameters was also much lower for GPR, which meant that the temporal development of the fitted GPR variogram model parameters was easier to interpret. Furthermore, the larger GPR measurement volume resulted in a low spatial nugget variance of 1 × 10−6 to 1 × 10−9 (m3 m−3)2 because short distance variation was averaged. This meant that GPR accurately measured spatial correlation lengths, even in the case of low water content variation. Interpolated maps showing the increase of water content due to irrigation and the subsequent gradual drying of the soil were more accurate and reproducible for GPR. It was concluded that the noninvasive GPR measurements provide the means to accurately and consistently monitor the development of spatial water content variation in time.

Dielectric Permittivity of Soils Mixed with Organic and Inorganic Fluids (0.02 GHz to 1.30 GHz)

Changes in the characteristics of the pore fluid in soils, such as concentration, valence, and permittivity, affect the electrical properties of the bulk fluid and the formation of double layers, causes volumetric changes and alters the fabric of the soil. The complex permittivity spectrum of a clay-fluid system reflects the polarizability of the phases and their interaction. This paper presents a review of polarization mechanisms, followed by high-frequency (MHz-GHz) experimental results involving two clays of very different specific surface, aqueous electrolytes with varied concentration and valence, and non-aqueous phase liquids NAPLs. Complex permittivity measurements reveal the effect of mixing order, both in the case of electrolytes and when the clay-fluid mixture includes organic liquids. The develop­ ment of double layers is hindered when NAPLs reach clay surfaces before water. Various processes that influence the complex permittivity of geomaterials are identified. Results are relevant to the interpretation of field measurements with ground penetrating radar and time domain reflectometry.

A Study on Relationship of Penetration Values to Absolute Viscosity of Petroleum Asphalt

According to JIS the values obtained in the penetration test of petroleum asphalt are related to its absolute viscosity values by an equation that has been derived theoretically on the assumption that a needle for the test is a cylinder with the same radius throughout. The equation is η={W•g•t•ln(a/b)/π•P2}×104 (poise) where η is the absolute viscosity value in poise, P is penetration degree, W is the load in gram, g is the acceleration of gravity in cm/sec2, a is the inner radius in cm of a vessel for specimens, and b is the radius in cm of the needle. The adaptability of this equation was examined in this study.It has been proved that this equation is valid in the case of penetration values higher than 50. Therefore, in other cases, the load should be increased or the penetrating time should be elongated so as to arrive at penetration values higher than 50, and then the absolute viscosity values could be calculated from the penetration values by this equation.