Adaptive opto-electromechanical silicon-on-insulator increased bandwidth accelerometer

This paper studies the construction of a compact one-dimension-sensing iscreased bandwidth photonic accelerometer using cascaded groups of continued sections of a 50 ng seismic mass each attached to the silicon beams of two under etched slot waveguide electrostatic phase shift elements acting as voltage-controlled adaptive-precision springs. The accelerometer sensitivity is shown to be significantly increased by applying equal electrode voltages. Simulation results indicate that the sensitivity dynamic range is about 76 dB combining both open-loop and closed-loop voltage control of the sensor. The operation bandwidth of the accelerometer may be increased up to 250 kHz due to the cascaded multi-section architecture of the sensor. This advantage gives significant relief to the limitation in bandwidth response of single section counterparts. The sensor may be designed to detect impact accelerations up to 104 ms−2 and yet can still be electrostatically driven to detect sub-gravitational accelerations. The application of negative feedback voltage control to hold the seismic mass at close distances from a standstill is shown to significantly increase the acceleration detection range. The construction uses all in-plane components based on a silicon-on-insulator template with 300 nm of silicon core thickness. The proposed electromechanical suspension system and the electric feeding arrangements are the most simple. The accelerometer performance is theoretically deterministic. The study is based on performing numerical analysis for the electromechanical suspension system. The waveguides are simulated utilizing the VPIphotonics industry standard. Applications may include the automobile and aerospace industries, underwater sonar, industrial ultrasonic detection, seismology predictions, and medical ultrasonography. Article Highlights The cascading of compact high-speed accelerometer sections allows increasing the bandwidth response of the proposed sensor by many folds compared to its single-mass single-section counterparts. The suspension structure is electrostatically controlled by two voltages enabling widely controlling the sensitivity and detection range of the accelerometer. The proposed accelerometer may fit wide applications achieving high detection speeds and super sensitivities utilizing a small footprint and power-efficient structure.

A Long Texts Summarization Approach to Scientific Articles

Automatic text summarization aims at condensing the contents of a text into a simple and descriptive summary. Summarization techniques drastically benefited from the recent advances in Deep Learning. Nevertheless, these techniques are still unable to properly deal with long texts. In this work, we investigate whether the combination of summaries extracted from multiple sections of long scientific texts may enhance the quality of the summary for the whole document. We conduct experiments on a real world corpus to assess the effectiveness of our proposal. The results show that our multi-section proposal is as good as summaries generated using the entire text as input and twice as good as single section.

Development of a 1,000-hp High-Power Density PMM for Deepwater Wireline Retrievable ESP Systems

Electric submersible pumps (ESP) are frequently used in offshore high-volume oil-producing wells that do not flow to the surface or in offshore wells with production rates that must be boosted to enhance financial returns. An operator in the deepwater Gulf of Mexico decided to install rigless ESP completions in its wells to mitigate the rig workover cost of interventions and ESP replacements by using slickline rather than more costly workover rigs. However, the solution required the development of a new single-section motor that could deliver 1,000 to 1,200 hp. This paper discusses the development and qualification of a new ultrahigh-power-density permanent magnet motor (UHPD PMM) for wireline-retrievable ESP systems installed through tubing as small as 5.5 in. The UHPD PMM design can produce significantly greater output than any other ESP technology in a single-section motor short enough to fit in a wireline lubricator. The high-power motor in a short length was achieved by integrating advanced motor technologies and materials. The challenges associated with this development are discussed along with the evaluation of tradeoffs between cost and performance. This paper also discusses the testing and qualification programs, as well as the results obtained during the various development phases.

Hidden Ground: Exploring an Approach to Educational Music for Strings

This article presents the findings of a study that explored the composition of Canadian educational music. Particularly, the authors focus on the analyses of composers’ scores on creating new string compositions for young musicians within the New Sounds of Learning Project. On a macro level, the composers predominantly composed multiple movements (three to four), using single section (A), binary (AB), ternary, or variation forms (A, A’, A”, A”’, etc.), and they adopted simple meters throughout. At the micro-level, the majority of the compositions also included a technical element that was used to further skill development, that is, lack of meter to focus attention, syncopation to develop rhythmic fluency, interactive rhythms between parts to promote player coordination, modular structure to address varied skill levels, or free rhythm to promote imaginative thinking. The findings will be of interest to those members of the music profession who promote or would like to promote the dissemination of new music for strings within educational settings in Canadian music classrooms.

Estimativa da produção de sedimentos utilizando a curva-chave de sedimentos

Quantification of sediment yield is important in determining the impacts of erosion processes on the watersheds. One way to determine their values is through the construction of the sediment-transport curve. The objective of this work is to calculate the sediment yield and to analyze the time variation in a hydrosedimentological monitoring station by designing and adjusting the sediment-transport curve, testing the deviations for curve fitting with a single section and divided into two sections. The 87380000 station is located in the municipality of Campo Bom (RS), operated by CPRM. The sediment-transport curve was built in a single section and divided into two sections. In addition, the Excel solver was used to set the curve to the data. Comparison of the relative standard deviation calculated for each curve allowed a comparison of the results. The sediment-transport curve. that best represented the data set was the one constructed with the split in two sections adjusted by the solver.

A Computational Study on Buckling Behavior of Cold-Formed Steel Built-Up Columns Using Compound Spline Finite Strip Method

This paper presents a computational methodology to compute the critical buckling stress of built-up cold-formed steel columns joined with discrete fasteners. The fasteners are modeled as three-dimensional beam elements, and their effect is integrated into the spline finite strip framework, evolving the compound strip methodology. Although this technique has been presented in the literature, this paper presents yet another robust framework for the buckling load evaluation of compound cold-formed steel columns with arbitrarily located fasteners. The proposed framework is applied to study the effect of fasteners on the formation of local, distortional, and global buckling modes of built-up section and a comparison is drawn with the buckling behavior of a single section. In this study, the proposed formulations are also used to get insights into the stability behavior of single-span and multi-span compound cold-formed steel columns in the presence of (i) fasteners with varied spacings with respect to span and (ii) the presence of the additional restraining system such as wall panels. For different buckling modes, a significant increment in buckling stress for a built-up section from a single section is observed when the fastener spacing is kept less than the critical buckling half-wavelength of the respective buckling modes. The study on the effect of wall panels shows that in comparison to unsheathed wall studs, the sheathed wall studs that produce additional constraints lead to the elimination of the global buckling deformations. The proposed formulations are simple, yet rigorous and have been validated using finite element-based numerical results.

The Light Field And The Scope Of Light Science

For centuries, light has been produced to enable the human visual system to operate but, today, light is being used for an increasing number of non-visual, technical purposes. Examples include plant growth, remote sensing, electricity generation, and communication. This paper discusses the theoretical foundation of such technical applications of light and shows that it is completely identical to the fundamentals of lighting. The foundation is the theory of the light field, which is generated by the interaction of the radiation field with a quadratic (energy) receiver. Within its range of applicability, the theory of the light field is complete and closed. As a result, the light field provides a unified theoretical base for lighting systems and the technical application of light. This creates the basis for combining them into a single section of science and technology, which will ensure their effective development and application.

Sr, S, and O Isotope Compositions of Evaporites in the Lanping–Simao Basin, China

Evaporites are widely distributed within continental “red beds” in the Lanping–Simao Basin, west Yunnan, China. Sr (Strontium), S (Sulfur), and O (Oxygen) isotope compositions have been measured on 54 sulfate or/and sulfate-bearing samples collected from Lanping, Nuodeng, Jinggu, Mengyejing, Baozang throughout the Lanping–Simao Basin. The 87Sr/86Sr ratios of all samples (0.708081 to 0.710049) are higher than those of contemporaneous seawater, indicating a significant continental contribution to the drainage basin. Sulfates in the Lanping Basin have higher 87Sr/86Sr ratios (0.709406 to 0.710049) than those (0.708081 to 0.709548) in the Simao Basin. Nevertheless, the δ34S values of gypsums (13.4‰ to 17.6‰) in Lanping and Baozang fall within the range of Cretaceous seawater. Gypsums from a single section in Baozang have trends of decreasing δ34S values and increasing 87Sr/86Sr ratios from base to top, indicating continental input played an increasingly significant role with the evaporation of brines. High δ34S values (20.5‰ to 20.7‰) of celestites in Lanping are probably caused by bacterial sulfate reduction (BSR) process in which 34S were enriched in residual sulfates and/or recycling of Triassic evaporites. The reduced δ34S values of gypsums (9.5‰ to 10.4‰) in Nuodeng could have been caused by oxidation of sulfides weathered from Jinding Pb-Zn deposit. The complex O isotope compositions indicate that sulfates in the Lanping–Simao Basin had undergone sulfate reduction, re-oxidation, reservoir effects, etc. In conclusion, the formation of continental evaporites was likely derived from seawater due to marine transgression during the Cretaceous period. Meanwhile, non-marine inflows have contributed to the basin significantly.