Development of a heavy demining machine

In the frame of the Belgian interuniversity project HUDEM (HUmanitarian DEMining), the Royal Military Academy (RMA) has started a research on the detection of plastic AP mines by means of ultrawideband ground penetrating radar (UWB GPR) i.e. GPR using ultra-short electromagnetic pulses (<200ps). Because AP mines are not buried at great depth and are very small objects, conventional GPR is not very well suited to detect all the mines without failure and to discriminate between a mine and a mine-like target. In the first part of the present paper we give a brief overview of the HUDEM project, its technical organization and test facilities. We also present results of outdoor trials with different GPR systems. We will highlight the advantage of UWB radar systems. Finally we motivate and discuss the development of some very small (10/spl times/5 cm), ultra-wideband directive TEM horn antennas. These antennas can be used in UWB applications, and they are, thanks to the reduced dimensions, suited for hand-held applications.

The paper proposes a method for determining specific soil resistance and presents the results of the conducted research. One of the main limiting factors in determining the working width of the tillage implement is specific soil resistance. This indicator is a quantitative characteristic of the labor intensity of soil tillage. Therefore, when designing new machinery, it is necessary to have reliable data on its value. The data presented in the scientific literature on the value of specific soil resistance are average and do not take into account the parameters of tillage working tools. Therefore, the determination of specific soil resistance for working tools with known parameters is the current topic of scientific research. The purpose of the research is to determine the value of specific soil resistance for working tools with known parameters. The research method consists of the experimental determination of the total draft resistance of the tillage implement and further mathematical processing of the experimental data obtained on the basis of the rational formula of V.P. Goryachkin. To conduct experimental research, a laboratory unit was developed, the design of which eliminates the impact of its weight on the draft resistance, arising from the friction between the parts of the working tool and soil. It was found that for the soils under consideration, which are typical for Northern Kazakhstan, the specific soil resistance is k = 45908 N/m2. The obtained coefficient of variation υ &lt; 10 % indicates a slight change in the considered variation. Therefore, the obtained value of the specific soil resistance is reliable. The results obtained will be used to substantiate the working width of the tillage implement with the working tools under consideration.

The assessment of the performances of ground-penetrating radar (GPR) in humanitarian demining is an important problem. These performances are related to the relative strength of the target radar response with respect to that of the soil. Many parameters influence both responses. The physical and geometrical parameters that influence the target signature include the soil electromagnetic (EM) constitutive parameters, the target depth and orientation with respect to the soil surface, the antenna height and the target EM and geometrical properties. This work presents a numerical parametric study of the soil and target radar signatures. The advantages of the numerical approach are: it allows for a separate study of the influence of each parameters on the radar responses, it is fast, cheap, generic with regards to hardware, and finally it is not prone to experimental errors and hardware failures or misuse. Moreover it is always possible to link the numerical experiments with a particular hardware by characterizing this latter. However, a number of simplifications, such as modeling the soil as a planar multilayered medium, are introduced to keep the problem tractable. This study yields surprising results, such as for example the possibility of considering the target in homogeneous space for computing its signature, as soon as it is a few centimeters deep. The target considered in the numerical experiments is a dielectric cylinder representing an AP mine, with diameter 6 cm and height 5 cm, and ɛrt=3. These values are chosen to approach as much as possible the physical properties of the M35BG AP mine, which is small and therefore difficult to detect.

This paper presents a field programmable gate array (FPGA) prototype of an 8-digit Fibonacci sequence generator. The design is based on the Verilog hardware description language, synthesized by the Xilinx Synthesis Technology (XST) synthesizer, and implemented with the ISE design flow. The circuit was tested to run on the Spartan-3E Starter Kit Board. The resource utilization and the test results are reported. The design itself can be an independent tool or a small device in a bigger system.

Selected tools for tile-setters (a transportable work station including a work table and platform with adjustable height, a device for transportation and tipping out mortar, and a tool box) were developed and designed in order to reduce the tile-setters' strain. Two prototypes of transportable work station were tested in 8 tile-setting companies and a learning centre. A questionnaire was worked out for the testing. Considering the test results and in co-operation with industrial manufacturers, the development will be finished so that the work station can go into production.

The digital world with all its gadgets, sites and useful services has become too comprehensive and comprehensive to fundamentally ignore it. The digital world offers significant opportunities for both individual users and institutions. Reforming the health care sector in Ukraine involves a significant emphasis on not using an increasing number of digital tools in the daily work of both medical institutions and doctors. Every day patients try to communicate with doctors through messengers, sending the latter their questions, test results, and other medical data. And although such online consultations are mostly not institutionalized, patients are primarily guided by the logic of convenience, accessibility and time saving, pressing the «send» button in the messenger to send a message to the doctor. At the same time, the use of digital technologies in health care is gaining more and more expressive forms due to the introduction of telemedicine, electronic prescriptions, or the availability of publicly available dashboards from the National Health Service. The dashboards contain arrays of data on the provision of medical services at the level of hospitals and the corresponding payments under contracts with the National Health Service. Access to all these benefits of the digital space requires at least a basic understanding of digital technologies to use them effectively. The article explains principals of digital literacy with emphasize on health care providers and explains how to understand modern digital technologies and not to fall into the traps of cybercriminals and misinformation online.

Operators continue to look for ways to improve hard rock drilling performance through emerging technologies. A consortium of Department of Energy, operator and industry participants put together an effort to test and optimize mud driven fluid hammers as one emerging technology that has shown promise to increase penetration rates in hard rock. The thrust of this program has been to test and record the performance of fluid hammers in full scale test conditions including, hard formations at simulated depth, high density / high solids drilling muds, and realistic fluid power levels. This paper details the testing and results of testing two 7 ¾" diameter mud hammers with 8 ½" hammer bits. A Novatek MHN5 and an SDS Digger FH185 mud hammer were tested with several bit types, with performance being compared to a conventional (IADC Code 537) tricone bit. These tools functionally operated in all of the simulated downhole environments. The performance was in the range of the baseline ticone or better at lower borehole pressures, but at higher borehole pressures the performance was in the lower range or below that of the baseline tricone bit. A new drilling mode was observed, while operating the MHN5 mud hammer. This mode was noticed as the weight on bit (WOB) was in transition from low to high applied load. During this new "transition drilling mode", performance was substantially improved and in some cases outperformed the tricone bit. Improvements were noted for the SDS tool while drilling with a more aggressive bit design. Future work includes the optimization of these or the next generation tools for operating in higher density and higher borehole pressure conditions and improving bit design and technology based on the knowledge gained from this test program.

Hydrogen fuel cell multiple unit vehicles are acquiring a central role in the transition process towards carbon neutral trains operation in non-electrified regional railway networks. In addition to their primary role as a transport mean, these vehicles offer significant potential for applications in innovative concepts such as smart grids. Compared to the pure electric propulsion systems, fuel cell technology allows for cogeneration processes by recovering generated heat in addition to the provision of the electrical power. This paper presents the analysis of fuel cell hybrid-electric multiple unit vehicle employed in regional railway transport during regular service, and in vehicle-to-grid application during the off-service hours, providing the electrical and thermal energy for stationary consumers in terminal stations. The system dynamics are modelled using a backward-looking quasi-static simulation approach, with implemented real-time optimization-based control strategy for managing the power flows between different components. In a case study of selected vehicle and railway services in the Netherlands, the fuel cell system showed average hydrogen consumption of 0.4 kg/km, with the overall electrical efficiency of 38.89%. In vehicle-to-grid scenario, the system satisfied complete stationary power demand, and provided about 327 kWh of thermal energy during 2-h operation, reaching the overall cogeneration efficiency of 66.81%.

Loads resulting from activities such as rock fall, heavy drop weights (for e.g. equipment's, heavy machines during installation), missile and aircraft interaction with slabs may results in loading intensity which have higher magnitude as compared to static loading. Based on the velocity of the impacting object at the time of contact, these activities may result in impact loading. Therefore, slabs designed should provide resistance to these accidental loading during their entire operational life. In this study, a dynamic non-linear finite element analyses were conducted to investigate the behavior of the reinforced concrete slabs subjected to high-mass low-velocity impacts. For this purpose, initially an already published impact test results were used to validate the numerical predictions. Following validation, a study was conducted to investigate the influence of the impact velocity on the behavior of the reinforced concrete slab. Based on the numerical investigation, it was found that the velocity of the impacting object has a significant influence on the behavior exhibited by slab under impact loading. Furthermore, it was also found that the behavior of slab under impact is both local and global. Local behavior is associated with the damage caused at the contact area of the slab and the impactor, whereas global behavior refers to the overall deformation of the slab when stress waves move away from the impact zone and travel towards the supports.

This study examines the academic tension between language precision and verbal proficiency within synchronous virtual language instruction. The digital sphere initiates unique restrictions, such as audio delay and limited non-verbal signals, which confuse the slight balance between immediate error feedback and continuous verbal output. This research highlights the particular obstacles learners face in developing fluency without paying attention to grammatical precision, a struggle frequently aggravated by the technological constraints of online engagement through virtual sessions. It further examines adaptive methods, such as employing text dialogue, for instance, gentle feedback, and influencing independent tools for comprehensive precision work. The results show that efficient digital learning necessitates an adjusted technique to the correction process, supporting multimodal assessment methods that enhance learners’ confidence and communicative implementation while efficiently tackling linguistic proficiency.

Economic dispatch based on optimal lambda using radial basis function network

N-methylol dimethyl phosphonopropionamide (MDPA) is one of the most utilized fire resistant (FR) finishes for cotton fabrics, utilized as part of a formulation with trimethylol melamine (TMM) to acquire better crosslinking and enhanced FR properties. The system parameters of the finishing treatment were upgraded for better FR properties and low mechanical loss to the fabric by the response surface methodology utilizing Box-Behnken statistical designed experimental strategy. The impacts of concentration on the cotton fabric's properties (fire resistance and mechanical properties) were assessed with the regression equations. The optimum conditions by predicting the FR reagents focusing intact mechanical properties of the fabric were additionally studied. It was found that the parameters of crosslinking agents in the FR formulation have a prime role in the general FR properties of the cotton fabrics. The R-squared estimations of the considerable number of responses were above 92%, demonstrating the level of relationship between the predicted values by the Box-Behnken frameworks and the real test results.

Physical modeling of cone penetration testing (CPT) can be carried out under known stress, deformation, and density conditions using laboratory calibration chambers. This study presents the results of reduced-scale model CPTs (MCPT) on Fraser River sand using a calibration chamber that allows anisotropic consolidation of soil specimens, as well as the measurement of shear wave velocity (VS), using bender elements. In addition to VS, MCPT can also measure cone tip resistance (qc), sleeve friction (fs), and pore water pressure developed behind the cone tip (Δu2). The CPT model tests are performed on Fraser River sand at different effective stresses and relative densities. The CPT calibration chamber test results are comparable with those of in situ seismic cone penetration tests (SCPT) in the Fraser River delta, existing correlations between VSand qc, and calibration chamber tests on other sands. This confirms the overall feasibility of the MCPT calibration chamber design for the measurements of qc, fs, and VSin sandy soils.

A 10bit, 20MS/s pipeline ADC is proposed for ZigBee transceiver in this paper. Due to demand of low power, a multiple sharing technique involved operational operational amplifier (opamp) and comparator is proposed, traditional S/H circuit is cancelled, a new gain boosting switch which could achieve sample and hold in first stage is also proposed. Implemented in a 0.18μm CMOS process, only 19.6mW power consumption from 1.8V power supply is achieved. SNR and SFDR are 61.5dB and 66.24dB, respectively, when a 1MS/s sinusoid signal inputs to the ADC at 20MS/s sampling rate. Particularly the test results show this pipeline ADC is suitable for a low power consumption ZigBee system.

Analysis for laterally loaded pile behavior on offshore sand slope crest considering friction effect and variational base angle in FW