Surveyor batteries Final engineering report

Design and performance of Surveyor spacecraft silver-zinc main batter

Near Infrared Imaging of the Hubble Deep Field with The Keck Telescope

Two deep K-band ($2.2 \mu m$) images, with point-source detection limits of $K=25.2$ mag (one sigma), taken with the Keck Telescope in subfields of the Hubble Deep Field, are presented and analyzed. A sample of objects to K=24 mag is constructed and $V_{606}-I_{814}$ and $I_{814}-K$ colors are measured. By stacking visually selected objects, mean $I_{814}-K$ colors can be measured to very faint levels; the mean $I_{814}-K$ color is constant with apparent magnitude down to $V_{606}=28$ mag.Comment: Replaced with slightly revised source positions and corrected V-I magnitudes (which were incorrect in the Tables and Figure 5). 18 pages. The data are publicly available at http://www.cco.caltech.edu/~btsoifer/hdf.html along with a high-resolution version of Fig.

Numerically improved computational scheme for the optical conductivity tensor in layered systems

The contour integration technique applied to calculate the optical conductivity tensor at finite temperatures in the case of layered systems within the framework of the spin-polarized relativistic screened Korringa-Kohn-Rostoker band structure method is improved from the computational point of view by applying the Gauss-Konrod quadrature for the integrals along the different parts of the contour and by designing a cumulative special points scheme for two-dimensional Brillouin zone integrals corresponding to cubic systems.Comment: 17 pages, LaTeX + 4 figures (Encapsulated PostScript), submitted to J. Phys.: Condensed Matter (19 Sept. 2000

Electrical transport properties of bulk Nic_{c}Fe1−c_{1-c} alloys and related spin-valve systems

Within the Kubo-Greenwood formalism we use the fully relativistic, spin-polarized, screened Korringa-Kohn-Rostoker method together with the coherent-potential approximation for layered systems to calculate the resistivity for the permalloy series Ni$_{c}$Fe$_{1-c}$. We are able to reproduce the variation of the resistivity across the entire series; notably the discontinuous behavior in the vicinity of the structural phase transition from bcc to fcc. The absolute values for the resistivity are within a factor of two of the experimental data. Also the giant magnetoresistance of a series of permalloy-based spin-valve structures is estimated; we are able to reproduce the trends and values observed on prototypical spin-valve structures.Comment: 6 pages, ReVTeX + 4 figures (Encapsulated Postscript), submitted to PR

Speckle Imaging Measurements of the Relative Tangential Velocities of the Components of T Tauri Binary Stars

Over a five year period, we have used speckle imaging to monitor 20 T Tauri binary stars with separations ranging from 0".09 to 1" (13-140 AU). This project is aimed at detecting the relative motion of the component stars to ascertain whether or not the observed companions (1) are stellar in nature, as opposed to being HH objects, and (2) are gravitationally bound to the primary stars. These observations demonstrate that speckle imaging measurements of close binary stars' separations can be made with an accuracy of a few milliarcseconds. The majority of the observed systems show significant relative velocities which (1) are not consistent with the motion expected for HH objects, (2) are greater than the velocity dispersion of these star-forming regions and thus are not the result of differential proper motion, and (3) are consistent with orbital motion. This is the first demonstration that these systems are physically bound. Furthermore, these relative velocity measurements provide dynamical evidence that the average total mass of these T Tauri binary star systems is ~l.7M_⊙

Effects of soybean lipid infusion on triglyceride and unbound free fatty acid levels in preterm infants

© 2018 Informa UK Limited, trading as Taylor & Francis Group Objective: To determine the plasma triglyceride (TG) and unbound free fatty acid (FFAu) levels in infants treated with increasing dosages of soybean lipid, intralipid (IL), infusion. Study design: TG and FFAu levels were measured in 78 preterm infants (BW 500–2000 g; GA 23–34 weeks) using the fluorescent probe ADIFAB2 and enzymatic method. Results: The infants’ BW was 1266.2 ± 440.7 g and GA 28.8 ± 3.1 weeks. TG levels were 77.4 ± 50 mg/dL, 140.2 ± 188 mg/dL (p \u3c .04 compared to levels during low dose IL infusion) and 135.6 ± 118 mg/dL (p \u3c .004), respectively during increased IL rates. FFAu levels were 17.7 ± 13 nM, 47.3 ± 102.8 nM (p = .07) and 98 ± 234 nM (p = .03). TG levels correlated with IL dose, the rate of IL administration, and FFAu levels. TG and FFAu levels were higher in infants below 28 weeks’ gestation Conclusions: Increasing dosage of IL is associated with increasing levels of TG and FFAu, especially in infants below 29 weeks of gestation. The increased level of FFAu suggests inefficient cellular utilization

INTEGRAL/SPI γ -ray line spectroscopy : Response and background characteristics

© 2018 ESO. Reproduced with permission from Astronomy & Astrophysics. Content in the UH Research Archive is made available for personal research, educational, and non-commercial purposes only. Unless otherwise stated, all content is protected by copyright, and in the absence of an open license, permissions for further re-use should be sought from the publisher, the author, or other copyright holder.Context. The space based γ-ray observatory INTEGRAL of the European Space Agency (ESA) includes the spectrometer instrument "SPI". This is a coded mask telescope featuring a 19-element Germanium detector array for high-resolution γ-ray spectroscopy, encapsulated in a scintillation detector assembly that provides a veto for background from charged particles. In space, cosmic rays irradiate spacecraft and instruments, which, in spite of the vetoing detectors, results in a large instrumental background from activation of those materials, and leads to deterioration of the charge collection properties of the Ge detectors.Aim. We aim to determine the measurement characteristics of our detectors and their evolution with time, that is, their spectral response and instrumental background. These incur systematic variations in the SPI signal from celestial photons, hence their determination from a broad empirical database enables a reduction of underlying systematics in data analysis. For this, we explore compromises balancing temporal and spectral resolution within statistical limitations. Our goal is to enable modelling of background applicable to spectroscopic studies of the sky, accounting separately for changes of the spectral response and of instrumental background.Methods. We use 13.5 years of INTEGRAL/SPI data, which consist of spectra for each detector and for each pointing of the satellite. Spectral fits to each such spectrum, with independent but coherent treatment of continuum and line backgrounds, provides us with details about separated background components. From the strongest background lines, we first determine how the spectral response changes with time. Applying symmetry and long-term stability tests, we eliminate degeneracies and reduce statistical fluctuations of background parameters, with the aim of providing a self-consistent description of the spectral response for each individual detector. Accounting for this, we then determine how the instrumental background components change in intensities and other characteristics, most-importantly their relative distribution among detectors.Results. Spectral resolution of Ge detectors in space degrades with time, up to 15% within half a year, consistently for all detectors, and across the SPI energy range. Semi-annual annealing operations recover these losses, yet there is a small long-term degradation. The intensity of instrumental background varies anti-correlated to solar activity, in general. There are significant differences among different lines and with respect to continuum. Background lines are found to have a characteristic, well-defined and long-term consistent intensity ratio among detectors. We use this to categorise lines in groups of similar behaviour. The dataset of spectral-response and background parameters as fitted across the INTEGRAL mission allows studies of SPI spectral response and background behaviour in a broad perspective, and efficiently supports precision modelling of instrumental background.Peer reviewedFinal Published versio

Разработка технологии ремонта и восстановления корпуса буксы оси колесной пары грузового вагона

Реферат Выпускная квалификационная работа 105 с., 0 рисунков, 23 таблицы, 24 источник, 2 приложения, 9 л. графического материала. Ключевые слова: наплавка, технология, режимы сварки, сила сварочного тока, сварочное оборудование, производительность, план участка, кантователь, промышленная безопасность, себестоимость. Актуальность работы: в данной выпускной квалификационной работе производится ремонт и восстановление корпуса буксы оси колесной пары грузового вагона. Объектом исследования является процесс восстановления корпус буксы. Цели и задачи исследования (работы). В результате данной работы следует получить производство с наибольшей степенью механизации и автоматизации повышающей производительность труда. Работа представлена введением, пятью разделами (главами) и заключением, приведен список использованных источников. В 1разделе/главе «Обзор литературы» произведен обзор литературы. Во 2 разделе/главе «Объект и методы исследования» Произведена формулировка проектной задачи и теоретический анализ. В 3 разделе/главе «Результаты проведенного исследования» Произведен инженерный расчет, рассмотрены конструкторская, технологическая и организационная части, рассмотрено пространственное расположение производственного процесса. В 4 разделе/главе «Финансовый менеджмент, ресурсоэффективность и ресурсосбережение» рассмотрены сравнительный экономический анализ вариантов, расчет технико-экономической эффективности, основные технико-экономические показатели участка. В 5 разделе/главе «Социальная ответственность» рассмотрена характеристика объекта исследования, вредные и опасные производственные факторы, источники и средства защиты от них, влияние их на организм человека и проектирование системы приточно-вытяжной вентиляции на разрабатываемом участке. В заключении приведено обоснование выбора способов сварки, сварочных материалов и оборудования. Разработаны мероприятия по безопасности жизнедеятельности, охране труда и совершенствованию организации труда. Посчитан экономический эффект от перечисленных нововведений, что позволяет судить о выгодности предлагаемого технологического процесса.Abstract Final qualifying work 105 pp., 0 pictures, 23 tables, 24 source, 2 applications 9 l. graphic material. Tags: welding technology, welding conditions, the welding current, welding equipment, performance, site plan, tilter, safety, costs. Relevance of the work: in the final qualifying work is carried out repair and restoration of the body axis of the wheel pair axle box of freight wagon. The object of research is the process of restoring the body of the journal box. The aims and objectives of the study (work). As a result of this work should be obtained from producing the greatest degree of mechanization and automation increases productivity. The work provides an introduction, five sections (chapters) and conclusion, a list of sources used. In 1razdele / chapter "Literature Review" produced a literature review. In the 2nd section / chapter "Object and Methods" Produced formulation of project objectives and theoretical analysis. In Section 3 / Chapter "The results of the study" Made engineering calculation, considered design, technological and organizational part, examined the spatial arrangement of the production process. a comparative economic analysis of the options discussed in Section 4 / Chapter "Financial management, resource efficiency and resource conservation", the calculation of technical and economic efficiency, the main technical and economic indicators of the site. In section 5 / chapter "Social responsibility" is considered characteristic of the object of study, harmful and dangerous production factors, sources and means of protection against them, their influence on the human body and design the system ventilation on the site to be developed. In conclusion, given rationale for the selection of welding, welding consumables and equipment. Actions on health and safety, labor protection and improvement of the labor organization. Calculate the economic impact of these innovations, which gives an indication of the profitability of the proposed proces

Исследование вариантов объединения на параллельную работу Иркутской и Якутской энергосистем

Объектом исследования является параллельна работа Иркутской и Якутской энергосистем. Цель работы – анализ электрических режимов Иркутской и западного района Якутской энергосистем и выбор возможных вариантов их объединения на параллельную работу. В процессе исследования моделировалась рабочая схема при объединение Иркутской и Якутской энергосистем, а также определение МДП и АДП по контролируемому сечению ВЛ 220 кВ ПС Усть-Кут – ПС Бобровка и проверялась динамическая устойчивость при нормативных возмущениях. Произведена оценка различных вариантов объединения двух энергосистем В результате исследования были выявленные наиболее эффективные способы объединения энергосистем.The object of the research is parallel to the work of the Irkutsk and Yakutsk energy systems. Purpose – analysis of electric modes of Irkutsk and Yakutsk western district energy systems and a choice of options for combining them in parallel. The study simulated the working circuit when the union of Irkutsk and Yakutsk energy systems, as well as determining мaximum allowed power flow and emergency power transfer limit on controlled sections line of 220 kV Ust-Kut – Bobrovka and tested the dynamic stability of the regulatory disturbances. An assessment of the different options for combining the two power systems As a result of the study were to identify the most effective ways of interconnection

Non-collinear magnetic structures: a possible cause for current induced switching

Current induced switching in Co/Cu/Co trilayers is described in terms of ab-initio determined magnetic twisting energies and corresponding sheet resistances. In viewing the twisting energy as an energy flux the characteristic time thereof is evaluated by means of the Landau-Lifshitz-Gilbert equation using ab-initio parameters. The obtained switching times are in very good agreement with available experimental data. In terms of the calculated currents, scalar quantities since a classical Ohm's law is applied, critical currents needed to switch magnetic configurations from parallel to antiparallel and vice versa can unambiguously be defined. It is found that the magnetoresistance viewed as a function of the current is essentially determined by the twisting energy as a function of the relative angle between the orientations of the magnetization in the magnetic slabs, which in turn can also explain in particular cases the fact that after having switched off the current the system remains in the switched magnetic configuration. For all ab-initio type calculations the fully relativistic Screened Korringa-Kohn-Rostoker method and the corresponding Kubo-Greenwood equation in the context of density functional theory are applied.Comment: 20 pages, 4 tables and 15 figures, submitted to PR