ESTIMATION OF THE MASS OF CARGO DUMP TRUCK

The article discusses an on-board weighing system for the load of a mining dump truck, which simplifies measurements and, unlike existing systems, does not require the integration of sensors into the structure and electrical circuits of the truck and represents a compact, autonomous device that can be located at any convenient place in the cab. In order to create such a device, it is proposed to use the magnitude of the magnetic field strength generated by DC traction motors as a signal carrying information about the mass of the transported cargo. To measure the magnetic field strength, a flux gate is used, which converts the magnitude of the magnetic field strength into the magnitude of the current. An original circuit for powering the fluxgate excitation winding using a modulated signal generator based on logic elements is proposed. The used power supply scheme allows to exclude the influence of the fluxgate excitation winding on the generator frequency, as well as to increase the fluxgate sensitivity, which makes it possible to install the sensor in any convenient place in the dump truck cabin, and not in the immediate vicinity of the traction motors.

Dynamic Mass Loss from Greenland's Peripheral Glaciers

While global glacier mass balance has decreased rapidly over the last two decades, mass loss has been greatest in regions with marine-terminating glaciers. In Greenland, peripheral glaciers and ice caps (GICs) cover only ~5% of Greenland’s area but contributed ~14-20% of the island’s ice mass loss between 2003-2008. Although Greenland GIC’s mass loss due to surface meltwater runoff have been estimated using atmospheric models, mass loss due to changes in ice discharge into surrounding ocean basins (i.e., dynamic mass loss) remains unquantified. Here, we use the flux gate method to estimate discharge from Greenland’s 594 marine-terminating peripheral glaciers between 1985 – 2018, and compute dynamic mass loss as the discharge anomaly relative to the 1985-1998 period. Greenland GIC discharge averages 2.14 Gt/yr from 1985-1998 and abruptly increases to an average of 3.87 Gt/yr from 1999-2018, indicating a -1.72 Gt/yr mass anomaly. This mass loss is driven by synchronous widespread acceleration around Greenland and, like the ice sheet, is primarily caused by changes in discharge from a small number of glaciers with larger discharge. These estimates indicate that although Greenland GICs are small, they are sensitive to changes in climate and should not be overlooked in future analyses of glacier dynamics and mass loss.

Increase of ice discharge from Greenland's peripheral tidewater glaciers over recent decades

<p>The Greenland Ice Sheet is losing mass at increasing rates. Substantial amounts of this mass loss occur by ice discharge. The ice sheet is surrounded by thousands of peripheral glaciers, which are dynamically decoupled from the ice sheet, and which account for ~10 % of the global glacier ice volume outside the two main ice sheets. Rather low-lying along the coasts, these peripheral glaciers are also losing mass at increasing, but disputed, rates. The total absence of knowledge about the role and share of solid ice discharge in this mass loss adds to the controversy. Since the quantification of ice discharge is still pending, a full understanding of ice mass loss processes in this globally important glacier region is substantially hampered.</p><p>Here, we present the first estimation of ice discharge from Greenland's peripheral tidewater glaciers. For each of these 760 glaciers, we combine an idealized rectangular flux gate cross sections derived from modelling with the Open Global Glacier Model with surface ice flow velocities derived from the ITS_LIVE and MEaSUREs remote sensing datasets to calculate glacier specific ice discharge on both annual and multi-annual time scales over the period 1985 to 2018. For the few glaciers not covered by either of the employed original datasets or modelling methods we use a regression tree-based extrapolation scheme to estimate the necessary input data for our calculation.</p><p>Our findings indicate a significant overall increase of ice discharge over the study period although several individual glaciers show contrasting developments. This increase became especially apparent across the southern parts of Greenland. Our results also show that the total of the ice discharge from Greenland's peripheral tidewater glaciers is dominated by few major contributors and that this dominance is completely time-independent.</p>

FLUXGATE MAGNETOMETERS WITH A NEW EXCITATION METHOD BASED ON MAGNETOELECTRIC INTERACTION

The analysis of the functional peculiarities of the known flux gates has shown that the constructive and technological methods used to increase their operational characteristics within the framework of traditional so-lutions have basically exhausted themselves. The paper proposes a method for exciting flux gates based on a new physical principle relying on the effect of magnetoelectric interaction. The possibility of obtaining a magnetoelectric effect in local inhomogeneities of solid-state structures of ferrite elements of flux-gates when exposed to an alternating electric field is analyzed and substantiated. In this case, in the entire volume of the fer-romagnetic core at the same frequencies of electromechanical and magnetic resonances, a modulating physical process is excited in the form of a standing magnetoelectric wave. This creates a corresponding magnetic modu-lation structure in the entire volume of the ferromagnetic system of the flux gate. The considered design of a fluxgate modulator implements a new method of exciting flux gates, containing a ferromagnetic rod system in the form of two ferrite rod half-elements, located coaxially and joined together by a ferrite permanent magnet with magnetization along the axis of the rods. The authors have experimentally studies a new method for exci¬ting flux gates. The proposed method for exciting flux gates opens up wide opportunities for research in a new direction in science – spintronics, in particular, the applied use of magnetoelectric interaction, which can be effectively used to create various options for flux gates based on new physical principles of operation.

The Influence of Pulsating Tensile Stress on Residual Magnetic Field of P91 Steel Samples

ABSTRACTMeasurements of Residual Magnetic Field RMF (the tangential component parallel to the load direction) were taken on the surface of P91 steel plate samples (X10CrMoVNb9-1) subjected to periodic pulsating tensile cyclic loads with the use of flux-gate and magneto impedance sensors, and preliminary measurement results are compiled and analyzed. The study investigates how the microstructure and load cycle parameters affect the RMF changes due to stress variations. Each combination of parameters: microstructure and load cycle corresponds to the characteristic variability pattern of magnetization and its maximum and minimum values.

Symmetric Magnetic Anomaly Objects’ Orientation Recognition Based on Local Binary Pattern and Support Vector Machine

In order to identify the orientation or recognize the attitude of small symmetric magnetic anomaly objects at shallow depth, we propose a method of extracting local binary pattern (LBP) features from denoised magnetic anomaly signals and classifying symmetric magnetic objects that have different orientations based on support vector machine (SVM). First, nine component signals, such as magnetic gradient tensor matrix, total magnetic intensity (TMI), and so forth, are calculated from the original signal detected by the flux gate sensors. The nine component signals are processed by discrete wavelet transform (DWT), which aims to reduce noise and make the signal’s features clear. Then we extract LBP texture features from the denoised nine component signals. From the simulation analysis, we can conclude that the LBP texture features of the nine component signals have good interclass discrimination and intraclass aggregation, which can be used for pattern recognition. Finally, the LBP texture features are constructed into feature vectors. The orientations of symmetric ferromagnetic objects underground are identified by SVM based on the feature vectors. Through experiments, we can conclude that the orientation recognition accuracy rate reaches 90%. This suggests that we can obtain the details of magnetic anomalies through our method.

A low-cost device for measuring local magnetic anomalies in volcanic terrain

Reconstructions of the past behavior of the geomagnetic field critically depend on the magnetic signal stored in extrusive igneous rocks. These rocks record the Earth's magnetic field when they cool and retain this magnetization on geological time scales. In rugged volcanic terrain, however, the magnetic signal arising from the underlying flows may influence the ambient magnetic field as recorded by newly formed flows on top. To measure these local anomalies in the Earth's magnetic field directly we developed a low-cost field magnetometer based on a flux gate sensor. To improve the accuracy of the obtained paleomagnetic vector and user friendliness of the device we combined this flux gate sensor with tilt and GPS sensors to rotate the measured magnetic vector to true North, East and down. The data acquisition is done using a ruggedized laptop and data are immediately available for first order interpretation. The first measurements done on Mt. Etna show local variations in the ambient magnetic field larger than expected, and illustrate both the accuracy (certainly