Avoiding conducted interference in the system of temperature control of the downhole tool

В данной статье описывается система термостатирования для скважинного прибора.Особенность этой системы состоит в использовании активного нагревателя и охладителя, управляемых с использованием широтно-импульсной модуляции. За основу системы взята схема термостатирования инклинометра ИГН 100-100/60-A. Однако у такой схемы присутствует серь?зный недостаток - кондуктивные помехи, которые оказывают влияние на работу скважинного источника питания, а значит, и всей электронной аппаратуры инклинометра. Во введении кратно описывает принцип работы системы термостатирования. Далее подробно рассмотрены причины кондуктивных помех, рассчитана величина провалов в отборе мощности, приведены графики, наглядно показывающие изменения сигнала. Выявлены проблемные элементы схемы, влияющие на возникновение помех. Проведен анализ возможных решений для устранения помехи, указаны недостатки каждого из решений.This article describes the temperature control system for a downhole tool. The peculiarity of this system isthat it is using a heater and an active cooler which are controlled by pulse width modulation. The basis of such asystem is taken from the thermostatic scheme of the inclinometer IGN 100-100 / 60-A. However, this scheme hasserious drawback - conducted interference. These disturbances affect the operation of a downhole power supply,and therefore the entire electronic inclinometer instrumentation. This article briefly describes the principle of thetemperature control system. Furthermore, reasons for this interference are discussed in detail, calculated the valueof failures in the selection of power, the graphs clearly show the changes in the signal. The problematic elements ofthe scheme, affecting the appearance of interference, are identified. The possible solutions to eliminate thisinterference are analyzed, stating the shortcomings of each of the solutions

Analyzing farmers' preferences for substrate supply contracts for sugar beets

Biogas production using biomass of agricultural origin plays a key role in Germany's energy transition process. Being the main substrate, maize has been increasingly criticized in recent years leading to a down-regulation of this crop for the use in biogas plants by an adjustment of the Renewable Energy Sources (RES) Act in 2012. Thus, it is necessary to widen the range of sustainable and suitable substrate alternatives. This study explores German farmers' willingness to grow sugar beets for biogas production based upon the analysis of a discrete choice experiment with 118 arable farmers conducted from November 2013 to February 2014. Models are estimated in willingness to pay space. Our results reveal that at least two-thirds of the participating farmers assess biogas production from sugar beets as an important and sustainable alternative to maize. However, with respect to their own farms, farmers prefer to maintain their status-quo instead of choosing a contract. Findings also indicate that risk-averse farmers are more likely to contract sugar beets as a biogas substrate than less risk-averse farmers resulting in a lower price demand. However risk-averse farmers prefer short contract periods and a small share of their arable land, otherwise they demand a markup. Regarding the expansion of renewable energies these findings are highly relevant for future political decisions that aim to enable a sustainable energy transition

Influence of the Characteristics of the STM-tip on the Electroluminescence Spectra

We analyze the influence of the characteristics of the STM-tip (applied voltage, tip radius) on the electroluminescence spectra from an STM-tip-induced quantum dot taking into account the many-body effects. We find that positions of electroluminescence peaks, attributed to the electron-hole recombination in the quantum dot, are very sensitive to the shape and size of the confinement potential as determined by the tip radius and the applied voltage. A critical value of the tip radius is found, at which the luminescence peak positions as a function of the tip radius manifest a transition from decreasing behavior for smaller radii to increasing behavior for larger radii. We find that this critical value of the tip radius is related to the confinement in the lateral and normal direction.Comment: 15 pages, 5 figure

Protective Rites in the Netra Tantra

This thesis examines the rites of protection as laid out in the Netra Tantra and its accompanying commentary by Kṣemarāja. This text and commentary help us to understand the ontological role of the court priest, who acts to preserve and improve the health and well-being of the monarch through constant ritual observance. This also leads to a discussion of power as religious, ritual, and social experience. I first examine ritual components, such as mantra, maṇḍala, and iconography to understand how the mantrin builds and maintains the tantric world. Within the iconography of practice, the Netra Tantra, allows for and even encourages the worship of its main deity, Amṛteśa, through the worship of a host of other deities. This brings about an examination of the conflict between public and private practice, especially within the tantric sphere. To further examine this conflict, I then explore initiatory rites, during which the practitioner finds himself reborn in both body and consciousness. Further, his rebirth forces him to reconsider his social place, with his caste now supplanted by his position as an initiated member of the religious group. I engage with both ideas of the body and identity to question how the newly initiated practitioner navigates the world with this new perspective, including his involvement, real or visualized, with the transgressive ritual behaviors so often associated with tantric practice. Finally, I consider specific practices, examining the technicalities of the rights and the meaning assigned to various ritual elements within this and related texts. The rites of nīrājana and those meant to conquer death, directly involve the mantrin who performs them on behalf of the monarch. This allows for an examination of what exactly is intended in such rites and what purpose they have for both the monarch and the mantrin

On the global hydration kinetics of tricalcium silicate cement

We reconsider a number of measurements for the overall hydration kinetics of tricalcium silicate pastes having an initial water to cement weight ratio close to 0.5. We find that the time dependent ratio of hydrated and unhydrated silica mole numbers can be well characterized by two power-laws in time, $x/(1-x)\sim (t/t_x)^\psi$. For early times $t < t_x$ we find an `accelerated' hydration ($\psi = 5/2$) and for later times $t > t_x$ a `deaccelerated' behavior ($\psi = 1/2$). The crossover time is estimated as $t_x \approx 16 hours$. We interpret these results in terms of a global second order rate equation indicating that (a) hydrates catalyse the hydration process for $t<t_x$, (b) they inhibit further hydration for $t > t_x$ and (c) the value of the associated second order rate constant is of magnitude 6x10^{-7} - 7x10^{-6} liter mol^{-1} s^{-1}. We argue, by considering the hydration process actually being furnished as a diffusion limited precipitation that the exponents $\psi = 5/2$ and $\psi = 1/2$ directly indicate a preferentially `plate' like hydrate microstructure. This is essentially in agreement with experimental observations of cellular hydrate microstructures for this class of materials.Comment: RevTeX macros, 6 pages, 4 postscript figure

Компьютерный анализ спирограммы у больных бронхиальной астмой

Main goal of this research is investigating of the breathing process and detection the features of the different groups of diseases. The study is based on using of spectral analysis' methods. The research is conducted on the real data of patients with various forms of asthma

Разработка аппаратного и программного обеспечения автономного контроллера сбора и обработки информации

Выпускная квалификационная работа 108 с., 7 рис., 20 табл., 17 источников, 11 прил. Ключевые слова: автономный контроллер, протокол ModBus, RS-485, RS-232, операционная система реального времени. Цель работы – проверка глубины и степени усвоения полученных навыков и знаний в процессе обучения, для получения степени дипломированный специалист. В процессе исследования проводился комплексный анализ по схемным и программым решениям серийно выпускаемых контроллеров. В результате исследования было разработано схемное решение поставленной задачи и осуществлено программирование разработанного контроллера. Основные конструктивные, технологические и технико-эксплуатационные характеристики: ‒ контроллер должен иметь два модема сотовой связи стандарта GSM с поддержкой 2G/3G; ‒ контроллер должен иметьnon

Reproducibility of Ba/Ca variations recorded by northeast Pacific bamboo corals

Author Posting. © American Geophysical Union, 2017. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 32 (2017): 966–979, doi:10.1002/2017PA003178.Trace elemental ratios preserved in the calcitic skeleton of bamboo corals have been shown to serve as archives of past ocean conditions. The concentration of dissolved barium (BaSW), a bioactive nutrientlike element, is linked to biogeochemical processes such as the cycling and export of nutrients. Recent work has calibrated bamboo coral Ba/Ca, a new BaSW proxy, using corals spanning the oxygen minimum zone beneath the California Current System. However, it was previously unclear whether Ba/Cacoral records were internally reproducible. Here we investigate the accuracy of using laser ablation inductively coupled plasma mass spectrometry for Ba/Cacoral analyses and test the internal reproducibility of Ba/Ca among replicate radial transects in the calcite of nine bamboo corals collected from the Gulf of Alaska (643–720 m) and the California margin (870–2054 m). Data from replicate Ba/Ca transects were aligned using visible growth bands to account for nonconcentric growth; smoothed data were reproducible within ~4% for eight corals (n = 3 radii/coral). This intracoral reproducibility further validates using bamboo coral Ba/Ca for BaSW reconstructions. Sections of the Ba/Ca records that were potentially influenced by noncarbonate bound Ba phases occurred in regions where elevated Mg/Ca or Pb/Ca and coincided with anomalous regions on photomicrographs. After removing these regions of the records, increased Ba/Cacoral variability was evident in corals between ~800 and 1500 m. These findings support additional proxy validation to understand BaSW variability on interannual timescales, which could lead to new insights into deep sea biogeochemistry over the past several centuries.NSF Grant Number: OCE-1420984; NOAA/OE Grant Number: NA16RP2637; MIT-WHOI Joint Program; American Geophysical Union Travel Grant; UC Davis President's Undergraduate Fellowship; Bowdoin College Gibbons Summer Research Fellowship2018-03-1