M(3000)F2 and IRI-2012 model at an equatorial latitude in the African sector

We have used ionosonde data from Ouagadougou (Geo. Lat.12.40 N, Long. 358.50, Magnetic declination -5.1320) to study the morphology of M(3000)F2 and to investigate the performance of IRI-12 during 1991 and 1995, years of high and low solar activities respectively. Results show that M(3000)F2 exhibits diurnal and solar cycle characteristics with no distinctive monthly/seasonal features. The two peaks which characterize the diurnal M(3000)F2 during high solar activity (HSA) are reduced to just one (the sunrise peak) during low solar activity (LSA). The study also shows that IRI-12 gives good representations of the observed values of M(3000)F2 with high correlation coefficient, R ranging between 0.9 and 0.95 during LSA and 0.94 and 0.99 during HSA. The model gives its best performance in the months of April irrespective of the solar activity. It either under-estimates or over-estimates the observed values of M(3000)F2 during other months.

Autofocus Entropy Repositioning Method Bioinspired in the Magnetic Field Memory of the Bees Applied to Pollination

In this paper, a bioinspired method in the magnetic field memory of the bees, applied in a rover of precision pollination, is presented. The method calculates sharpness features by entropy and variance of the Laplacian of images segmented by color in the HSV system in real-time. A complementary positioning method based on area feature extraction between active markers was developed, analyzing color characteristics, noise, and vibrations of the probe in time and frequency, through the lateral image of the probe. From the observed results, it can be seen that the unsupervised method does not require previous calibration of target dimensions, histogram, and distances involved in positioning. The algorithm showed less sensitivity in the extraction of sharpness characteristics regarding the number of edges and greater sensitivity to the gradient, allowing unforeseen operation scenarios, even in small sharpness variations, and robust response to variance local, temporal, and geophysical of the magnetic declination, not needing luminosity after scanning, with the two freedom of degrees of the rotation.

The True North Urgency of the Earth in Determining the Direction of the Qibla According to Fiqh and Falak Science

True North true north is any point on the earth to the North pole, this is because the North and South poles point precisely to the earth's axis of rotation. Therefore true north is North based on the earth's axis not North based on the earth's magnetism. So the difference is true North shows the true north direction of the earth while magnetic North is the North direction of the magnetic compass needle. Magnetic north does not coincide with Earth's true north. To find out the true North of the earth using a compass, you need to know the magnetic declination first. To know the magnetic declination can be done through a magnetic declination calculator such as WMM (world magnetic model) which can be downloaded through the crowdmag application playstore. In determining the direction of the Qibla it is required to determine the True North point of the earth.

Tadeusz Konrad Przypkowski (1905–1977) – gnomonik z Jędrzejowa

Niniejszy artykuł przedstawia biografię naukową Tadeusza Konrada Przypkowskiego (1905–1977), wybitnego eksperta w dziedzinie gnomoniki – jest to pierwsze w literaturze tak obszerne opracowanie tego tematu. Był on z wykształcenia historykiem sztuki i nauki, doktoryzował się w 1929 roku na podstawie pracy o XVII-wiecznym rzeźbiarzu małopolskim Janie Pfisterze, a habilitował w 1965 roku na podstawie pracy Naukowe pojęcie deklinacji magnetycznej w Polsce. Od najmłodszych lat interesował się gnomoniką, rekonstruował i tworzył nowe zegary słoneczne, restaurował zabytkowe. Prowadził badania, publikując na ten temat artykuły w czasopismach naukowych i popularnonaukowych. Jego pasja, którą była gnomonika, sprawiła, że stał się wybitnym specjalistą znanym i cenionym w kraju i na świecie. Wielokrotnie pełnił rolę konsultanta i wykonawcy zegarów słonecznych. Brał udział w sympozjach i konferencjach naukowych, na których wygłaszał odczyty, entuzjastycznie przyjmowane przez uczestników. Do dnia dzisiejszego jego prace można oglądać i podziwiać w wielu miastach w Polsce i za granicą. Tadeusz Konrad Przypkowski (1905–1977) – a gnomonist from Jędrzejów (Poland) This article presents the scientific biography of Tadeusz Konrad Przypkowski (1905–1977), an outstanding expert in the field of gnomonics. This is the first such comprehensive study of this subject in literature. T.K. Przypkowski was a historian of art and science, and obtained his doctorate in 1929 based on the work of Jan Pfister, a 17th century sculptor, and he received a tenure in 1965 based on the work Scientific concept of magnetic declination in Poland. From an early age, he was interested in gnomonics, and would reconstruct and create new sundials, as well as restore antique ones. He conducted research, published articles in scientific and popular scientific journals. His passion for gnomonics made him an outstanding specialist known and appreciated at home and in the world. He was a consultant and a sundial maker many times. He participated in symposia and scientific conferences at which he delivered papers enthusiastically received by participants. To this day his works can be sees and admired in many cities in Poland and abroad.

Analysis of Magnetic Anomaly Characteristics of Underground Non-Coplanar Cross-buried Iron Pipelines

The non-coplanar cross-buried pipelines are a common way of pipeline wiring. In order to investigate the magnetic anomaly characteristics of the non-coplanar cross-buried pipelines and guide the site operation, the influences of a series of factors on the magnetic anomaly of the non-coplanar cross-buried pipelines are analyzed. Based on the principle of magnetic dipole construction, a forward model is established for the magnetic anomaly characteristics of the subsurface non-coplanar cross-buried pipelines. The basic characteristics of magnetic anomaly for the non-coplanar cross-buried pipelines are defined. The influences of geomagnetic parameters (geomagnetic intensity, geomagnetic inclination, and geomagnetic declination), pipeline parameters (thickness, magnetic susceptibility), and cross angle of pipelines on the characteristics of magnetic anomalies are analyzed. The results show that the shape of the total magnetic anomaly is mainly affected by the magnetic inclination, and the curve of magnetic anomaly at ± I site shows some symmetry. The amplitude is approximately linearly affected by the total geomagnetic field, magnetic declination, pipeline thickness, material magnetic susceptibility, and pipeline cross angle. There is a periodic change of the amplitude with the increase of geomagnetic inclination (−90°–>90°). The crest-trough distance is mainly affected by geomagnetic inclination, magnetic declination, thickness, magnetic susceptibility, and pipeline cross angle. A more accurate measurement can be achieved if the direction of the pipelines is roughly measured and then the number of measurement points is augmented near the intersection of pipelines and the measurement lines. Present work obtains the equivalent magnetic dipole units by segmenting pipelines. The magnetic anomaly characteristics of non-coplanar crossed iron pipelines are successfully simulated. The numerical results are in accordance with the experimental analysis.

Athanasius Kircher and Terrestrial Magnetism: The Magnetic Map

Athanasius Kircher paid special attention to magnetism, more specifically terrestrial one, in his work Magnes sive de arte magnetica. Other Jesuits of his time, such as Garzoni and Cabeo, also wrote on this subject. Kircher studied in particular magnetic declination and its possible use to determine geographical longitudes. At his time, this was an important subject for long sea journeys. First, he collected a large number of observations of magnetic declination from different sources in three tables and two lists with a total of 518 values, among them forty-three made by Jesuits. Kircher proposed that a magnetic map could be made based on these observations, but he did not do it. From Kircher’s observations a map of magnetic declination has been drawn and it is presented here. Kircher discussed the causes of declination and presented a model for the origin of the magnetic field of the Earth, which differed from that proposed by Gilbert. Kircher finally considered magnetism as a cosmic force with its origin in God.

Introduction

Jesuit scholars have pursued studies in mathematics and science since the founding of the order. Authors in this issue discuss the work on magnetic declination by the Jesuit polymath Athanasius Kircher, the reform of Spanish naval education using the treatise on naval warfare by the Jesuit Paul Hoste, the Jesuit contributions to the Japanese clock-making industry, the dissemination of scientific knowledge through the Jesuit journal Brotéria, the Jesuit Erich Wasmann’s attempts to grapple with Darwinian evolution, Jesuit contributions to understanding the natural environment of India, and the many accomplishments of the Jesuit-run Vatican Observatory.