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Journal articles on the topic 'Magnetické sondy'

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1

Bajracharya, Uday, and Prabhat Rawal. "In vitro study of Magnetic Resonance Imaging artifacts of anesthetic devices." Journal of Society of Anesthesiologists of Nepal 2, no. 1 (October 1, 2015): 13–16. http://dx.doi.org/10.3126/jsan.v2i1.13551.

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Background: Deep sedation or general anesthesia is usually required for Magnetic Resonance Imaging when patients cannot remain motionless in the suite. Various anesthetic devices have been used to maintain the airway and ventilate the lungs during this period. Some of them produce artifacts that pose difficulties in the interpretation of images. The aim of this study was to identify the devices that produced artifacts during Magnetic Resonance Imaging.Methods: Twelve anesthetic devices were considered: oro-pharyngeal airway, nasopharygeal airway, face mask with reservoir bag, nasal cannula, endotracheal tube, disposable Ambu Laryngeal Mask Airway, Laryngeal Mask Airway Unique, Disposable Laryngeal Tube Sonda, i-gel, Ambu bag, Bain Circuit, Jackson Rees Circuit. Magnetic Resonance Imaging was performed with each device placed on the top of a phantom simulator respectively to resemble the position in vivo.Results: The artifacts with Disposable Laryngeal Tube Sonda, Laryngeal Mask Airway Unique and endotracheal tube were related to ferromagnetic material in the pilot valve and were similar. No artifacts were found with oro-pharyngeal airway, nasopharygeal airway, nasal cannula, endo-tracheal tube with pilot valve detached, face masks with reservoir bag (metal removed), Ambu bag (without Adjustable Pressure Limiting valve), i-gel , disposable Ambu Laryngeal Mask Airway, Bain Circuit and Jackson Rees Circuit.Conclusion: Anesthetic devices that produce Magnetic Resonance Imaging artifacts are disposable Laryngeal Tube Sonda, Laryngeal Mask Airway Unique and Endotracheal Tube.Journal of Society of Anesthesiologists of Nepal 2015; 2(1): 13-16
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2

Hardman, R. H., and L. C. Shen. "Theory of induction sonde in dipping beds." GEOPHYSICS 51, no. 3 (March 1986): 800–809. http://dx.doi.org/10.1190/1.1442132.

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The analysis necessary for the computation of the response of an induction sonde in dipping beds is developed. The boundary‐value problem solved is for a bed of uniform thickness surrounded by two infinitely thick shoulder beds. The source is a magnetic dipole oriented in an arbitrary direction and located in any of the three media. The resulting electromagnetic fields in all three media are obtained. From these fields, induction logs are calculated for a focused induction sonde (6FF40) passing through a dipping bed. Under the assumptions of negligible borehole effect and no invasion, the analysis is also used to obtain correction charts for dipping beds.
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3

Santos, Fabricio Simão dos, Simoni Maria Gheno, and Sebastião Elias Kuri. "Microscopia de varredura por sonda (SPM) aplicada a aços inoxidáveis dúplex." Rem: Revista Escola de Minas 60, no. 1 (March 2007): 183–87. http://dx.doi.org/10.1590/s0370-44672007000100028.

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Nesse trabalho, a microscopia de varredura por sonda (Scanning Probe Microscopy - SPM), nos modos contato (Atomic Force Microscopy - AFM) e de força magnética (Magnetic Force Microscopy - MFM), foi utilizada para analisar a microestrutura de um aço inoxidável dúplex 2205 solubilizado e envelhecido. Foi feita uma análise por AFM da superfície do aço solubilizado após crescimento de filme passivo. Por AFM, obteve-se indicação de crescimento de filme sobre a microestrutura do aço solubilizado, enquanto por MFM a distribuição de fases pôde ser observada sem a necessidade de ataque da superfície.
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4

Bajracharya, Uday, and Prabhat Rawal. "In Vitro Study of Magnetic Resonance Imaging Artifacts of Anesthetic Devices." Medical Journal of Shree Birendra Hospital 14, no. 1 (May 9, 2016): 20–24. http://dx.doi.org/10.3126/mjsbh.v14i1.14837.

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Introduction: Deep sedation or general anesthesia is usually required for Magnetic Resonance Imaging when patients cannot remain motionless in the suite. Various anesthetic devices have been used to maintain the airway and ventilate the lungs during this period but some of them produce artifacts that pose difficulties in the interpretation of images. The aim of this study was to identify the devices that produced artifacts during Magnetic Resonance Imaging.Methods: Twelve anesthetic devices were considered: oro-pharyngeal airway, naso-pharygeal airway, face mask with reservoir bag, nasal cannula, endotracheal tube, disposable Ambu Laryngeal Mask Airway, Laryngeal Mask Airway Unique, Disposable Laryngeal Tube Sonda, i-gel, Ambubag, Bain Circuit, Jackson Rees Circuit.Magnetic Resonance Imaging was performed with each device placed on the top of a phantom simulator respectively to resemble the position in vivo.Results: The artifacts with Disposable Laryngeal Tube Sonda, Laryngeal Mask Airway Unique and endotracheal tube were related to ferromagnetic material in the pilot valve were similar. No artifacts were found with oro-pharyngeal airway, naso-pharygeal airway, nasal cannula, endo-tracheal tube with pilot valve detached, face masks with reservoir bag (metal removed), Ambu bag (without Adjustable Pressure Limiting valve), i-gel , disposable Ambu Laryngeal Mask Airway, Bain Circuit and Jackson Rees Circuit.Conclusions: Anesthetic devices not containing any ferromagnetic material are recommended for use during MRI scanning to reduce artifacts.
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5

Wiedemeier, Todd H., Barbara H. Wilson, Mark L. Ferrey, and John T. Wilson. "Efficacy of an In-Well Sonde to Determine Magnetic Susceptibility of Aquifer Sediment." Groundwater Monitoring & Remediation 37, no. 2 (January 12, 2017): 25–34. http://dx.doi.org/10.1111/gwmr.12197.

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6

Fattakhova, L. A., V. P. Shcherbakov, D. M. Kuzina, A. N. Dautov, and N. K. Sycheva. "Changes in the Magnetic Properties of Soddy-Podzolic Soils Depending on the Conditions of Soil Formation." Izvestiya, Atmospheric and Oceanic Physics 56, no. 10 (December 2020): 1235–46. http://dx.doi.org/10.1134/s0001433820100023.

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7

Pauwels, Herman, and Hua Zhang. "The Uniform φ-Theory for the Sony Mode in FLCD." Ferroelectrics 278, no. 1 (January 2002): 101–11. http://dx.doi.org/10.1080/00150190214477.

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8

Tao, Xu, Luo Wusheng, Lu Haibao, and Lu Qin. "Design of underground sonde of a directional drilling locator system." Sensors and Actuators A: Physical 119, no. 2 (April 2005): 427–32. http://dx.doi.org/10.1016/j.sna.2004.10.030.

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9

Babanin, V. F., V. I. Nikolaev, D. E. Pukhov, A. M. Shipilin, and O. A. Shirmina. "Diagnostics of manganese-iron nodules in soddy-podzolic soils at different degrees of gleyzation from their magnetic properties." Eurasian Soil Science 40, no. 3 (March 2007): 247–55. http://dx.doi.org/10.1134/s1064229307030027.

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10

Ashraf, Imran, Soojung Hur, Sangjoon Park, and Yongwan Park. "DeepLocate: Smartphone Based Indoor Localization with a Deep Neural Network Ensemble Classifier." Sensors 20, no. 1 (December 24, 2019): 133. http://dx.doi.org/10.3390/s20010133.

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A quickly growing location-based services area has led to increased demand for indoor positioning and localization. Undoubtedly, Wi-Fi fingerprint-based localization is one of the promising indoor localization techniques, yet the variation of received signal strength is a major problem for accurate localization. Magnetic field-based localization has emerged as a new player and proved a potential indoor localization technology. However, one of its major limitations is degradation in localization accuracy when various smartphones are used. The localization performance is different from various smartphones even with the same localization technique. This research leverages the use of a deep neural network-based ensemble classifier to perform indoor localization with heterogeneous devices. The chief aim is to devise an approach that can achieve a similar localization accuracy using various smartphones. Features extracted from magnetic data of Galaxy S8 are fed into neural networks (NNs) for training. The experiments are performed with Galaxy S8, LG G6, LG G7, and Galaxy A8 smartphones to investigate the impact of device dependence on localization accuracy. Results demonstrate that NNs can play a significant role in mitigating the impact of device heterogeneity and increasing indoor localization accuracy. The proposed approach is able to achieve a localization accuracy of 2.64 m at 50% on four different devices. The mean error is 2.23 m, 2.52 m, 2.59 m, and 2.78 m for Galaxy S8, LG G6, LG G7, and Galaxy A8, respectively. Experiments on a publicly available magnetic dataset of Sony Xperia M2 using the proposed approach show a mean error of 2.84 m with a standard deviation of 2.24 m, while the error at 50% is 2.33 m. Furthermore, the impact of devices on various attitudes on the localization accuracy is investigated.
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Scott, James F. "Physics of Oxides for Future Devices." MRS Bulletin 35, no. 3 (March 2010): 227–30. http://dx.doi.org/10.1557/mrs2010.656.

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AbstractFerroelectric oxides underwent a renaissance in the 1980s and 1990s, driven by the success in commercializing thin-film ferroelectric random-access memory devices (FRAMs) for applications such as the SONY PlayStation 2 memory board. Materials scientists gravitated into this new field from magnetic oxides and from high-Tcsuperconductivity. But as the FRAM prospects wane and neither dynamic random-access memory devices nor FLASH memory has been replaced, we now require new directions for materials research on oxides. In this article, I outline briefly four new directions for ferroelectric oxide research: something old—ferroelectrically induced ferromagnetism and multiferroic switching; something new—THz emission from oxide ferroelectrics; something borrowed—Heisenberg-like switching of domains in nanoferroelectrics; and something blue—ZnO light-emitting devices. Magnetoelectricity—the linear coupling of polarization and magnetization—was theoretically predicted by Igor Dzyaloshinskii in 1957 and measured experimentally by Astrov two years later. It did not produce commercial devices. Although a flurry of new work occurred in the 1970s, emphasizing boracites—mostly by Hans Schmid in Geneva, no materials were found that exhibited large effects at room temperature. In the past decade, the search has been renewed, emphasizing rare earth systems such as Tb manganites.
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12

E. Thomas, Jewel, Nyakno J. George, Aniekan M. Ekanem, and Nsikak E. Ekpenyong. "Ionospheric induced plasma disturbances afore the m7.9 eastern Sichuan china earthquake of 12th may, 2008." International Journal of Advanced Geosciences 7, no. 2 (December 15, 2019): 194. http://dx.doi.org/10.14419/ijag.v7i2.29980.

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A great number of earthquakes occur yearly in different areas and almost 100 -120 of them have a magnitude above 5. These seismic activities are very harmful for the inhabitants. Findings reveal that this seismo-electro-magnetic abnormality is a mirror image of some processes, which originated a few weeks before the main event and stay until few days after it. Plasma ion analyser (IAP) and Instrument Sonde de Langmuir (ISL) sensors) experiments available on Detection of Electromagnetic Emissions Transmitted from Earthquake Regions (DEMETER) and Total Electron Content (TEC) from Global Positioning System (GPS) satellites, were employed to study the variations of electron and ion density for ionospheric disturbances before the M7.9 Eastern Sichuan China earthquake of 12th May, 2008. The study revealed seismo-ionospheric induced perturbations exactly three weeks afore the earthquake in all four investigated parameters. Electron density recorded 16.94 cm-3, electron temperature revealed - 2.25 o C while total ion density displayed 6.57 cm-1. The total electron content ranged from 4.28 to 3.6. The disturbance storm time (Dst) and planetary 3-hourly range (Kp) indices were used to classify pre-earthquake anomalies from the other anomalies associated with geomagnetic activities and was seen that this day (-21days relative to the earthquake) was devoid of geomagnetic storm, thus the observed perturbations were seismo-induced but not geomagnetic induced.
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Kück, Jochem, Marco Groh, Martin Töpfer, Andreas Jurczyk, and Ulrich Harms. "New geophysical memory-logging system for highly unstable and inclined scientific exploration drilling." Scientific Drilling 29 (April 26, 2021): 39–48. http://dx.doi.org/10.5194/sd-29-39-2021.

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Abstract. We established a cable-free memory-logging system for drill-string-deployed geophysical borehole measurements. For more than 20 years, various so-called “logging while tripping” (LWT) techniques have been available in the logging service industry. However, this method has rarely been used in scientific drilling, although it enables logging in deviated and unstable boreholes, such as in lacustrine sediment drilling projects. LWT operations have a far lower risk of damage or loss of downhole logging equipment compared with the common wireline logging. For this purpose, we developed, tested, and commissioned a modular memory-logging system that does not require drill string modifications, such as special collars, and can be deployed in standard wireline core drilling diameters (HQ, bit size of 96 mm, and PQ, bit size of 123 mm). The battery-powered, autonomous sondes register the profiles of the natural GR (gamma radiation) spectrum, sonic velocity, magnetic susceptibility, electric resistivity, temperature, and borehole inclination in high quality while they are pulled out along with the drill string. As a precise depth measurement carried out in the drill rig is just as important as the actual petrophysical downhole measurements, we developed depth-measuring devices providing a high accuracy of less than 0.1 m deviation from the wireline-determined depth. Moreover, the modular structure of the system facilitates sonde deployment in online mode for wireline measurements.
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Yamafuji, Kazuo, and Takashi Kawamura. "Factory Tour to INA Facility, Nidec Sankyo." International Journal of Automation Technology 2, no. 2 (March 5, 2008): 141–43. http://dx.doi.org/10.20965/ijat.2008.p0141.

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1. Introduction of Nidec Sankyo and INA Facility Sankyo was established by three engineers in 1946 immediately after the Second World War as in the cases of Sony and Honda which were founded as venture enterprise and have developed to world leading companies. To begin with orgel, the company has produced high tech products such as machine tool, magnetic application machinery, optical instrument, card reader, and robot, appreciated by users. In 2003 the company became a member of Nidec group. The recent world market share of the company's product accounts for 80% in card reader for financial terminal, 70% in large LCD panel handling robot, 70% in COMBO type light pickup, and 40% in stepping motor for video camera. The company has sales of 112.6 billion yen and about 1,300 employees in 2007. The production and R&D facilities of Sankyo in Japan are located in Shimosuwa, Ina and Komagane. INA Facility we toured this time produces mainly industrial robot with the sales of 21 billion yen. The employees number about 180, 80 of them are engaged in design and development of machinery and electricity, 50 in manufacturing, and the rest, 50 in support business like purchase, production control and quality control.
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Seepe, Hlabana Alfred, Tselane Geneva Ramakadi, Charity Mekgwa Lebepe, Stephen O. Amoo, and Winston Nxumalo. "Antifungal Activity of Isolated Compounds from the Leaves of Combretum erythrophyllum (Burch.) Sond. and Withania somnifera (L.) Dunal against Fusarium Pathogens." Molecules 26, no. 16 (August 5, 2021): 4732. http://dx.doi.org/10.3390/molecules26164732.

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Crop diseases caused by Fusarium pathogens, among other microorganisms, threaten crop production in both commercial and smallholder farming. There are increasing concerns about the use of conventional synthetic fungicides due to fungal resistance and the associated negative effects of these chemicals on human health, livestock and the environment. This leads to the search for alternative fungicides from nature, especially from plants. The objectives of this study were to characterize isolated compounds from Combretum erythrophyllum (Burch.) Sond. and Withania somnifera (L.) Dunal leaf extracts, evaluate their antifungal activity against Fusarium pathogens, their phytotoxicity on maize seed germination and their cytotoxicity effect on Raw 264.7 macrophage cells. The investigation led to the isolation of antifungal compounds characterized as 5-hydroxy-7,4′-dimethoxyflavone, maslinic acid (21-hydroxy-3-oxo-olean-12-en-28-oic acid) and withaferin A (4β,27-dihydroxy-1-oxo-5β,6β-epoxywitha-2-24-dienolide). The structural elucidation of the isolated compounds was established using nuclear magnetic resonance (NMR) spectroscopy, mass spectroscopy (MS) and, in comparison, with the available published data. These compounds showed good antifungal activity with minimum inhibitory concentrations (MIC) less than 1.0 mg/mL against one or more of the tested Fusarium pathogens (F. oxysporum, F. verticilloides, F. subglutinans, F. proliferatum, F. solani, F. graminearum, F. chlamydosporum and F. semitectum). The findings from this study indicate that medicinal plants are a good source of natural antifungals. Furthermore, the isolated antifungal compounds did not show any phytotoxic effects on maize seed germination. The toxicity of the compounds A (5-hydroxy-7,4′-dimethoxyflavone) and AI (4β,27-dihydroxy-1-oxo-5β,6β-epoxywitha-2-24-dienolide) was dose-dependent, while compound B (21-hydroxy-3-oxo-olean-12-en-28-oic acid) showed no toxicity effect against Raw 264.7 macrophage cells.
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Kryzhanovskyi, V. G., S. P. Serhiienko, D. V. Chernov, and V. V. Kryzhanovsky. "Listening to NFC at higher harmonic frequencies." Radiotekhnika, no. 204 (April 9, 2021): 99–104. http://dx.doi.org/10.30837/rt.2021.1.204.11.

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The widespread use of the NFC technology (Near Field Communication) arouses interest to various security aspects. There are known examples of information exchange with card at a distance greater than standard 5-10 cm. It is also interesting to use signals of higher harmonics, which potentially may be radiated in the form of electromagnetic waves, rather than exists as a magnetic field of scattering. In this work, the radiation of third harmonic by card of standard ISO 14443-3А with the fundamental frequency 13.56 MHZ for various excitation modes using the RFID-RC522 reader, smartphone Sony Xperia Z5 Premium, and continuous 10% amplitude modulated 13.56 MHz signal from generator with the subcarrier of imitated smart card response 847.5 kHz was investigated. The card response at third harmonic was simulated in circuit analysis software. Both simulation and experiment proved, that the third harmonic with its side frequencies 40,68 ± 0,8475 MHz have the highest level after the fundamental. To receive the third harmonic signal, the resonant loop antenna in the form of ring vibrator loaded on capacitor was used. This allows the sizes of the received system to be reduced, but the problem of complex field structure in the near-field zone remains. Due to narrow bandwidth of the receiver antenna, the registration of card response signal was complicated. The experiments with three methods of signal generation proved, that third-harmonic signal is registered at the distance more than 1.5m, which may pose a threat for contactless smart-cards transactions security. At the same time, the influence of high level of noise at such a distance may cause difficulties to decode the short-duration signals, which requires further study.
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Howard, A. Q., and W. C. Chew. "Electromagnetic borehole fields in a layered, dipping‐bed environment with invasion." GEOPHYSICS 57, no. 3 (March 1992): 451–65. http://dx.doi.org/10.1190/1.1443259.

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Electromagnetic modeling of an induction sonde (1–100 kHz) in a dipping‐bed environment is a 3-D problem. The capability for such an analysis is necessary for interpretation of oil‐well logs in offshore environments where most holes are deviated. 3-D geometrical effects require vector field analysis. The method accounts for transverse magnetic mode (TM) coupling arising from surface charges deposited by eddy currents passing through bed boundaries. If borehole and invasion effects are included, the only available rigorous analytical methods are finite elements or finite‐difference techniques. These approaches require large‐scale computing. In contrast, our method is approximate and is an extension of the geometrical‐factor theory and Born approximation. The variational method does not require matrices and is numerically simpler than the more rigorous finite element method. The method uses a new electric field vector integral equation developed by Chew. The formulation accounts for low‐frequency behavior at bed boundaries where current channeling and surface charge phenomena dominate the interactions. The receiver voltage has two parts, a volumetric term [Formula: see text] and a surface term [Formula: see text]. The term [Formula: see text] reduces to the Born result when the dip angle goes to zero; [Formula: see text] accounts for the surface charge effect and is only significant when the receivers are in close proximity to a bed boundary. The local nature of the charge interaction results from double scattering events, which are necessary to produce this effect. The charge term is second order as explained intuitively in terms of polarization. The bed boundary interaction is proportional to the factor [Formula: see text], where [Formula: see text] is the dip angle, and [Formula: see text] and [Formula: see text] are the conductivities of the adjacent beds. Since the charge interaction is strongly nonlinear in conductivity, common induction log interpretation, which assumes linearity, is expected to fail near bed boundaries. Results for dip angles up to 60 degrees for variational results and eigenfunction solutions for the case of no borehole or invasion show good agreement. A few 3-D results are computed with simultaneous layering, dip, and invasion.
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Mandic, Milan, and Natasa Rancic. "Low power laser in the treatment of the acute low back pain." Vojnosanitetski pregled 68, no. 1 (2011): 57–61. http://dx.doi.org/10.2298/vsp1101057m.

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Beckground/Aim. Acute low back pain (ALBP) is one of the most frequent painful conditions in the human population. The objective of the paper was to compare the efficacy of the low power laser (LPL) in the pain and the muscular spasm reduction with conservative methods of physical medicine. Method. The prospective cohort study was done. The study involved 70 patients, both men and women, from 25 to 64 years of age with the diagnosis of ALBP. Two groups were formed. There were 40 patients in the first group and they were treated with the LPL with frequency of 73 Hz. The second group was the control one and it consisted of 30 patients who were treated with conservative methods of physical medicine (electrotherapy: diadynamic currents CP ? 3 and CP ? 3, interferent currents - 90 Hz for 15 min; electrophoresis with novocaine). The ALBP were diagnosed by clinical examination and by the nuclear magnetic resonance imaging (NMRI). The low power laser - Gallium Arsenide (GaAs) was used. The laser sonde consisted of 4 laser diodes, each powered of 15 mW, wavelength 904 nm and with frequency 73Hz. The total period of time for each treatment was 10 minutes and the total dose per treatment was 15 J. The intensity of acute low back pain was assessed by Roland?s scale. The degree of the spasm was assessed in the relaxed position and during movements. Results. The average score in the first group before the onset of rehabilitation was 3.3 ? 1.1 (Me = 3.0), and in the control group was 3.43 ? 0.89 (Me = 3.0). After five treatments in patients who were treated with LPL the average score in Roland?s scale was decreased (1.12 ? 1.3, Me = 2.0) and in the control group there were no changes. After 10 treatments with the LPL the analgesic effect was obtained in 82.5% of patients from the first group and in 20% of patients in the control group. The analgesic effect in patients of the first group was obtained after 7.5 ? 2.1 treatments and in the second group after 17.9 ? 3.2 treatments. The difference was statistically significant (t = 15.652173, p < 0.001). The spasm disappeared in 92.5% of patients in the first group and in 20% of patients in the control group after 7.02 ?2.2 and 17.9 ? 3.2 treatments respectively. The difference was statistically significant (t = 15.652173, p < 0.001). Conclusion. The pain and spasm reduction were obtained in the greater number of patients by usage of the LPL than by usage of conservative methods of physical medicine.
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Prammer, M. G., J. Bouton, E. D. Drack, M. N. Miller, and R. N. Chandler. "A New Multiband Generation of NMR Logging Tools." SPE Reservoir Evaluation & Engineering 4, no. 01 (February 1, 2001): 59–63. http://dx.doi.org/10.2118/69670-pa.

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Summary This paper describes the hardware and operation of a new generation of nuclear magnetic resonance (NMR) logging tools. In the past, NMR required the logging engineer to consider the T1 relaxation times of the reservoir fluids likely to be encountered. Actual, or simply assumed, long T1's translated into slow logging speeds. The new tool generation overcomes this limitation. The key feature is that nine sensitive volumes are polarized in parallel and are read out in rapid sequence. A new sonde design speeds up the polarization process by a factor of 2. Each volume contributes equally to the result and can support identical measurements for rapid stacking and fast logging, and each can be used for individual, simultaneous measurements. Laboratory data and field-test results are presented to demonstrate both the relative simplicity of operation and the improvement in data quality. Logging speeds typically can be upgraded by a factor of 4, while data for total porosity determination and fluid typing are acquired in a single logging pass. Background Over the past few years, log analysts have become familiar with the potential and the limitations of NMR logging. Basically, an NMR tool reports the total number of hydrogen atoms that are in the liquid or gaseous state. As such, NMR is a lithology-independent porosity tool as long as the hydrogen index of the fluids can be estimated. The commercial use of modern pulsed-NMR tools (NUMAR's MRIL1,***, and Schlumberger's CMR,2,**** brought two surprises:The near-borehole zone, which was assumed to be flushed, can contain substantial amounts of native hydrocarbons, both oil and gas.The T1 relaxation times of hydrocarbons (connate fluids and filtrate from oil-based muds) under reservoir conditions are substantially longer than previously assumed. The consequence of these findings was that NMR began to be used as a hydrocarbon-detection and reservoir-quantification tool, at the expense of logging speed and wellsite efficiency.3,4 From the theory of nuclear spin relaxation in liquids by Bloembergen, Purcell, and Pound5 follows the proportionality of bulk relaxation time and self-diffusion coefficient: T1~D. The Stokes relationship between viscosity and correlation time stipulates that D~T/µ; therefore, we can expect that T1~T/µ over a certain range of temperatures. We conducted measurements of T1 and T2 in the 30 to 150°C range on oils used for oil-based mud synthesis.***** Some of our results are listed in Table 1. These oils are typically type C16/C18, with hydrogen indices close to that of water. The absence of longer chains or aromatics suggests short correlation times and long T1 relaxation times for Larmor frequencies in the low-MHz range. For all samples investigated, T1=T2. In general, our data confirm the expected temperature dependency of T1. Certain oils, however, including Oil B and Oil C in Table 1, show a sharp discontinuity at some point between 110 and 150°C. We have confirmed that no chemical change takes place in the oil because the original T1 can be restored by cooling the sample to room temperature and exposing it to the atmosphere. The most likely explanation is dissolved oxygen that becomes volatile above 110°C. Paramagnetic oxygen is a potent relaxation agent even at low concentrations, and its disappearance at high temperatures causes an additional increase in T1. The surface interaction, which is responsible for rapid relaxation/polarization in the water phase, is inefficient for oil, even in cases where rock analysis would classify the rock as oil-wet. Gas is another example of high T1's (4-5 sec and more) caused by weak internal relaxation and nonexistent interaction with the rock surface. T 1 affects data acquisition and logging speed in a direct fashion:The hydrogen atoms must be exposed to the polarizing magnetic field for a multiple of T1. A factor of 3 is considered minimum. Fig. 1 illustrates exponential polarization curves for T1's of 1 sec, 2 sec, and 4 sec. Note that 95% polarization is reached only after 12 sec for fluids with T1=4 sec.The measurement itself is contaminated by thermal noise and must be repeated a few times to bring the influence of this noise down to acceptable levels. After each measurement, a full wait time (tw) of at least 3× T1 is required. Assuming 8 repeats and T1=4 sec, we find that the wait times required for a single measurement add up to 8×4×3=96 sec. If a vertical resolution of 3 ft is acceptable, the NMR tool cannot move faster than 3×60/96˜2 ft/min. A speed limit of 120 ft/hr makes it impractical to deploy NMR on a routine basis over large openhole intervals. An undesirable option is to forego full polarization. This mode is faster but results in data that are substantially harder to interpret in a quantitative fashion. Furthermore, this mode defeats the unique capability of NMR to detect hydrocarbons independent of resistivity contrast. It is highly desirable to use an NMR tool that is virtually free of T1 effects. Current NMR applications such as total and effective porosities, pore-size distribution, permeability modeling, hydrocarbon typing, and gas detection require that all hydrogen components are equally visible; i.e., even the slowest T1 component should be fully polarized. Furthermore, these applications should run at logging speeds of 1,000-1,500 ft/hr. Lastly, a higher level of automation should reduce the amount of job planning and setup procedures required today. These requirements are met by the newest generation of MRIL tools, MRIL-Prime. The T1 problem is solved by using a large number of measurement volumes in parallel and by employing a new prepolarization scheme. New Tool Features The key feature of the new MRIL tool is the ability to rapidly polarize and to read out many identical measurement volumes. The scheme is illustrated in Fig. 2. There are nine tightly packed cylindrical shells, each 24 in. tall and each containing on average 750 mL. The tool electronics can rapidly switch back and forth between volumes by changing the operating frequency over a wide range. The magnetic field gradient translates lower operating frequencies into resonance conditions that occur farther away from the tool. The gradient is circularly symmetric, resulting in resonance shells around the tool. These shells are labeled A (innermost, diameter 14 in.) to J (outermost, diameter 16.5 in.). In an 8-in. borehole, these diameters correspond to a depth of investigation between 3 and 4 in. The individual volumes are completely separated such that concurrent measurements do not influence each other. The approximate field strength, resonance frequency, and magnetic field gradient for each measurement volume is listed in Table 2.
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Sanna, Samuele. "SPETTROSCOPIA MUONICA: UNA SONDA MICROSCOPICA PER IL MAGNETISMO." Istituto Lombardo - Accademia di Scienze e Lettere - Rendiconti di Scienze, July 30, 2014. http://dx.doi.org/10.4081/scie.2011.85.

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The muon spectroscopy is an experimental technique which employs muon beams to study the properties of condensed matter. In particular, it allows us to study static and dynamic processes in magnetic materials (e.g. iron magnets/antiferromagnets, spin glasses, frustrated, etc) and superconductors, as well as chemical reactions and diffusion phenomena of charged and neutral particles. Here we will describe at the elementary level the physical principles of this technique, highlighting especially the use in the microscopic study of the magnetic properties of materials.
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21

Siswanto, Siswanto, Gunawan Pria Utama, and Windu Gata. "Pengamanan Ruangan Dengan Dfrduino Uno R3, Sensor Mc-38, Pir, Notifikasi Sms, Twitter." Jurnal RESTI (Rekayasa Sistem dan Teknologi Informasi) 2, no. 3 (October 26, 2018). http://dx.doi.org/10.29207/resti.v2i3.592.

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Security officers can not monitor the security of the financial space at all times especially outside working hours or evenings because the financial room is on the 3rd floor. Security guards are not warned quickly if there are people who do not have the right to enter the financial room at the time of blank or after hours. The purpose of this research is to design an application that can monitor the security of financial space by giving information or giving warning in the form of alarm and sending SMS and Twitter notification to security officer if there are people who do not have access rights of financial space, using DFRduino Uno R3 microcontroller, MC-38 magnets, PIR sensors, Alarms, Sony Ericsson Z530i phone, wifi modem, and Bluetooth. If a door or movement is detected the computer will send a command to DFRduino which is then forwarded to the alarm to give a sound alert. And with the Hanphone Sony Ericsson Z530i with a connection via Bluetooth Mobile can connect with the application so that the computer can send notification SMS alert to the number that has been registered as the recipient of SMS and notification via Twitter to the username that has been registered. With the magnet sensor it is possible to detect if the door or window is forced and PIR sensor is used as a support if the magnetic sensor is not working or if the thief enter the room not through the door or window. PIR Sensor installed in the room allows all activities that occur will be able to monitor well. If there is a security breach or infiltration it will be quickly known because there are warnings via SMS and Twitter that can provide information to security personnel to perform actions quickly so that cases can be resolved thoroughly.
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"Andrzej Michałowski, Jakub Niebieszczański, Milena Teska, Patrycja Kaczmarska, Non-invasive magnetometric prospection in forested area: the case study of Mirosław site 37 in Northwestern Poland." PLURAL. History, Culture, Society 7, no. 2 (December 30, 2019): 156–67. http://dx.doi.org/10.37710/plural.v7i2_9.

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The following article concerns the results of a combined non-invasive and invasive fieldworks in Mirosław, site 37 (Piła county, Wielkopolska voivodeship, Northern Poland). The site is a Wielbark culture barrow cemetery located in a forested area, thus limiting it access to a variety of methods. With the usage of a single-sonde gradientometer it was possible to survey the site by the means of magnetometry. The magnetic map of the site indicated presence of eroded mound (possibly due to ploughing) with associated grave-pit as well as numerous other anomalies, including the position of a burnt structure in between the barrows. Consecutive excavations were aimed to verify the interpretation of the magnetometry survey and confirmed the presence of an denudated barrow with a grave-pit within. In the light of results, the visible anomalies seen as a specific forest type of ploughing should be treated as the main factor of the barrow destruction. Also the earthworks revealed that the anomaly interpreted as a burnt structure appeared to be a hearth. All of the excavated objects were associated with the Wielbark culture, thus indicating the potential of investigating areas between the preserved barrows, which might bear other features of funeral rites and similar activities.
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