Science.gov

Sample records for 40-bit floating point

  1. The application of the ADSP-21020 40-bit floating point DSP microprocessor in a digital Doppler radar

    SciTech Connect

    Robinson, S.H.; Morrison, R.E.

    1991-08-26

    A continuous wave doppler radar system has been designed which is portable, easily deployable and can be remotely controlled. The system is immune to ground clutter and is used for wind speed detection and direction determination. Nearly real time digital signal processing is performed by an Analog Devices ADSP-21020, a 40-bit floating point Digital Signal Processing (DSP) microprocessor. This paper provides an overview of the design of the system including the radio frequency (RF) to digital interface. The various DSP detection algorithms are discussed and compared to system performance and sensitivity. Finally, DSP performance is compared to the performance of an earlier system using Analog Device's ADSP-2100. 6 refs.

  2. Hardware description ADSP-21020 40-bit floating point DSP as designed in a remotely controlled digital CW Doppler radar

    SciTech Connect

    Morrison, R.E.; Robinson, S.H.

    1991-01-01

    A continuous wave Doppler radar system has been designed which is portable, easily deployed, and remotely controlled. The heart of this system is a DSP/control board using Analog Devices ADSP-21020 40-bit floating point digital signal processor (DSP) microprocessor. Two 18-bit audio A/D converters provide digital input to the DSP/controller board for near real time target detection. Program memory for the DSP is dual ported with an Intel 87C51 microcontroller allowing DSP code to be up-loaded or down-loaded from a central controlling computer. The 87C51 provides overall system control for the remote radar and includes a time-of-day/day-of-year real time clock, system identification (ID) switches, and input/output (I/O) expansion by an Intel 82C55 I/O expander. 5 refs., 8 figs., 2 tabs.

  3. Floating Point Control Library

    Energy Science and Technology Software Center (ESTSC)

    2007-08-02

    Floating Point Control is a Library that allows for the manipulation of floating point unit exception masking funtions control exceptions in both the Streaming "Single Instruction, Multiple Data" Extension 2 (SSE2) unit and the floating point unit simultaneously. FPC also provides macros to set floating point rounding and precision control.

  4. NULL convention floating point multiplier.

    PubMed

    Albert, Anitha Juliette; Ramachandran, Seshasayanan

    2015-01-01

    Floating point multiplication is a critical part in high dynamic range and computational intensive digital signal processing applications which require high precision and low power. This paper presents the design of an IEEE 754 single precision floating point multiplier using asynchronous NULL convention logic paradigm. Rounding has not been implemented to suit high precision applications. The novelty of the research is that it is the first ever NULL convention logic multiplier, designed to perform floating point multiplication. The proposed multiplier offers substantial decrease in power consumption when compared with its synchronous version. Performance attributes of the NULL convention logic floating point multiplier, obtained from Xilinx simulation and Cadence, are compared with its equivalent synchronous implementation. PMID:25879069

  5. NULL Convention Floating Point Multiplier

    PubMed Central

    Ramachandran, Seshasayanan

    2015-01-01

    Floating point multiplication is a critical part in high dynamic range and computational intensive digital signal processing applications which require high precision and low power. This paper presents the design of an IEEE 754 single precision floating point multiplier using asynchronous NULL convention logic paradigm. Rounding has not been implemented to suit high precision applications. The novelty of the research is that it is the first ever NULL convention logic multiplier, designed to perform floating point multiplication. The proposed multiplier offers substantial decrease in power consumption when compared with its synchronous version. Performance attributes of the NULL convention logic floating point multiplier, obtained from Xilinx simulation and Cadence, are compared with its equivalent synchronous implementation. PMID:25879069

  6. Program Converts VAX Floating-Point Data To UNIX

    NASA Technical Reports Server (NTRS)

    Alves, Marcos; Chapman, Bruce; Chu, Eugene

    1996-01-01

    VAX Floating Point to Host Floating Point Conversion (VAXFC) software converts non-ASCII files to unformatted floating-point representation of UNIX machine. This is done by reading bytes bit by bit, converting them to floating-point numbers, then writing results to another file. Useful when data files created by VAX computer must be used on other machines. Written in C language.

  7. Improvements in floating point addition/subtraction operations

    DOEpatents

    Farmwald, P.M.

    1984-02-24

    Apparatus is described for decreasing the latency time associated with floating point addition and subtraction in a computer, using a novel bifurcated, pre-normalization/post-normalization approach that distinguishes between differences of floating point exponents.

  8. An integrated circuit floating point accumulator

    NASA Technical Reports Server (NTRS)

    Goldsmith, T. C.

    1977-01-01

    Goddard Space Flight Center has developed a large scale integrated circuit (type 623) which can perform pulse counting, storage, floating point compression, and serial transmission, using a single monolithic device. Counts of 27 or 19 bits can be converted to transmitted values of 12 or 8 bits respectively. Use of the 623 has resulted in substantial savaings in weight, volume, and dollar resources on at least 11 scientific instruments to be flown on 4 NASA spacecraft. The design, construction, and application of the 623 are described.

  9. Open source high performance floating-point modules.

    SciTech Connect

    Underwood, Keith Douglas

    2006-02-01

    Given the logic density of modern FPGAs, it is feasible to use FPGAs for floating-point applications. However, it is important that any floating-point units that are used be highly optimized. This paper introduces an open source library of highly optimized floating-point units for Xilinx FPGAs. The units are fully IEEE compliant and achieve approximately 230 MHz operation frequency for double-precision add and multiply in a Xilinx Virtex-2-Pro FPGA (-7 speed grade). This speed is achieved with a 10 stage adder pipeline and a 12 stage multiplier pipeline. The area requirement is 571 slices for the adder and 905 slices for the multiplier.

  10. Defining the IEEE-854 floating-point standard in PVS

    NASA Technical Reports Server (NTRS)

    Miner, Paul S.

    1995-01-01

    A significant portion of the ANSI/IEEE-854 Standard for Radix-Independent Floating-Point Arithmetic is defined in PVS (Prototype Verification System). Since IEEE-854 is a generalization of the ANSI/IEEE-754 Standard for Binary Floating-Point Arithmetic, the definition of IEEE-854 in PVS also formally defines much of IEEE-754. This collection of PVS theories provides a basis for machine checked verification of floating-point systems. This formal definition illustrates that formal specification techniques are sufficiently advanced that is is reasonable to consider their use in the development of future standards.

  11. Design of a reversible single precision floating point subtractor.

    PubMed

    Anantha Lakshmi, Av; Sudha, Gf

    2014-01-01

    In recent years, Reversible logic has emerged as a major area of research due to its ability to reduce the power dissipation which is the main requirement in the low power digital circuit design. It has wide applications like low power CMOS design, Nano-technology, Digital signal processing, Communication, DNA computing and Optical computing. Floating-point operations are needed very frequently in nearly all computing disciplines, and studies have shown floating-point addition/subtraction to be the most used floating-point operation. However, few designs exist on efficient reversible BCD subtractors but no work on reversible floating point subtractor. In this paper, it is proposed to present an efficient reversible single precision floating-point subtractor. The proposed design requires reversible designs of an 8-bit and a 24-bit comparator unit, an 8-bit and a 24-bit subtractor, and a normalization unit. For normalization, a 24-bit Reversible Leading Zero Detector and a 24-bit reversible shift register is implemented to shift the mantissas. To realize a reversible 1-bit comparator, in this paper, two new 3x3 reversible gates are proposed The proposed reversible 1-bit comparator is better and optimized in terms of the number of reversible gates used, the number of transistor count and the number of garbage outputs. The proposed work is analysed in terms of number of reversible gates, garbage outputs, constant inputs and quantum costs. Using these modules, an efficient design of a reversible single precision floating point subtractor is proposed. Proposed circuits have been simulated using Modelsim and synthesized using Xilinx Virtex5vlx30tff665-3. The total on-chip power consumed by the proposed 32-bit reversible floating point subtractor is 0.410 W. PMID:24455466

  12. The Unified Floating Point Vector Coprocessor for Reconfigurable Hardware

    NASA Astrophysics Data System (ADS)

    Kathiara, Jainik

    There has been an increased interest recently in using embedded cores on FPGAs. Many of the applications that make use of these cores have floating point operations. Due to the complexity and expense of floating point hardware, these algorithms are usually converted to fixed point operations or implemented using floating-point emulation in software. As the technology advances, more and more homogeneous computational resources and fixed function embedded blocks are added to FPGAs and hence implementation of floating point hardware becomes a feasible option. In this research we have implemented a high performance, autonomous floating point vector Coprocessor (FPVC) that works independently within an embedded processor system. We have presented a unified approach to vector and scalar computation, using a single register file for both scalar operands and vector elements. The Hybrid vector/SIMD computational model of FPVC results in greater overall performance for most applications along with improved peak performance compared to other approaches. By parameterizing vector length and the number of vector lanes, we can design an application specific FPVC and take optimal advantage of the FPGA fabric. For this research we have also initiated designing a software library for various computational kernels, each of which adapts FPVC's configuration and provide maximal performance. The kernels implemented are from the area of linear algebra and include matrix multiplication and QR and Cholesky decomposition. We have demonstrated the operation of FPVC on a Xilinx Virtex 5 using the embedded PowerPC.

  13. Floating-to-Fixed-Point Conversion for Digital Signal Processors

    NASA Astrophysics Data System (ADS)

    Menard, Daniel; Chillet, Daniel; Sentieys, Olivier

    2006-12-01

    Digital signal processing applications are specified with floating-point data types but they are usually implemented in embedded systems with fixed-point arithmetic to minimise cost and power consumption. Thus, methodologies which establish automatically the fixed-point specification are required to reduce the application time-to-market. In this paper, a new methodology for the floating-to-fixed point conversion is proposed for software implementations. The aim of our approach is to determine the fixed-point specification which minimises the code execution time for a given accuracy constraint. Compared to previous methodologies, our approach takes into account the DSP architecture to optimise the fixed-point formats and the floating-to-fixed-point conversion process is coupled with the code generation process. The fixed-point data types and the position of the scaling operations are optimised to reduce the code execution time. To evaluate the fixed-point computation accuracy, an analytical approach is used to reduce the optimisation time compared to the existing methods based on simulation. The methodology stages are described and several experiment results are presented to underline the efficiency of this approach.

  14. Fast and efficient compression of floating-point data.

    PubMed

    Lindstrom, Peter; Isenburg, Martin

    2006-01-01

    Large scale scientific simulation codes typically run on a cluster of CPUs that write/read time steps to/from a single file system. As data sets are constantly growing in size, this increasingly leads to I/O bottlenecks. When the rate at which data is produced exceeds the available I/O bandwidth, the simulation stalls and the CPUs are idle. Data compression can alleviate this problem by using some CPU cycles to reduce the amount of data needed to be transfered. Most compression schemes, however, are designed to operate offline and seek to maximize compression, not throughput. Furthermore, they often require quantizing floating-point values onto a uniform integer grid, which disqualifies their use in applications where exact values must be retained. We propose a simple scheme for lossless, online compression of floating-point data that transparently integrates into the I/O of many applications. A plug-in scheme for data-dependent prediction makes our scheme applicable to a wide variety of data used in visualization, such as unstructured meshes, point sets, images, and voxel grids. We achieve state-of-the-art compression rates and speeds, the latter in part due to an improved entropy coder. We demonstrate that this significantly accelerates I/O throughput in real simulation runs. Unlike previous schemes, our method also adapts well to variable-precision floating-point and integer data. PMID:17080858

  15. Bifurcated method and apparatus for floating point addition with decreased latency time

    DOEpatents

    Farmwald, Paul M.

    1987-01-01

    Apparatus for decreasing the latency time associated with floating point addition and subtraction in a computer, using a novel bifurcated, pre-normalization/post-normalization approach that distinguishes between differences of floating point exponents.

  16. CMOS floating-point vector-arithmetic unit

    NASA Astrophysics Data System (ADS)

    Timmermann, D.; Rix, B.; Hahn, H.; Hosticka, B. J.

    1994-05-01

    This work describes a floating-point arithmetic unit based on the CORDIC algorithm. The unit computes a full set of high level arithmetic and elementary functions: multiplication, division, (co)sine, hyperbolic (co)sine, square root, natural logarithm, inverse (hyperbolic) tangent, vector norm, and phase. The chip has been integrated in 1.6 micron double-metal n-well CMOS technology and achieves a normalized peak performance of 220 MFLOPS.

  17. Multi-input and binary reproducible, high bandwidth floating point adder in a collective network

    DOEpatents

    Chen, Dong; Eisley, Noel A; Heidelberger, Philip; Steinmacher-Burow, Burkhard

    2015-03-10

    To add floating point numbers in a parallel computing system, a collective logic device receives the floating point numbers from computing nodes. The collective logic devices converts the floating point numbers to integer numbers. The collective logic device adds the integer numbers and generating a summation of the integer numbers. The collective logic device converts the summation to a floating point number. The collective logic device performs the receiving, the converting the floating point numbers, the adding, the generating and the converting the summation in one pass. One pass indicates that the computing nodes send inputs only once to the collective logic device and receive outputs only once from the collective logic device.

  18. Fixed-Rate Compressed Floating-Point Arrays.

    PubMed

    Lindstrom, Peter

    2014-12-01

    Current compression schemes for floating-point data commonly take fixed-precision values and compress them to a variable-length bit stream, complicating memory management and random access. We present a fixed-rate, near-lossless compression scheme that maps small blocks of 4(d) values in d dimensions to a fixed, user-specified number of bits per block, thereby allowing read and write random access to compressed floating-point data at block granularity. Our approach is inspired by fixed-rate texture compression methods widely adopted in graphics hardware, but has been tailored to the high dynamic range and precision demands of scientific applications. Our compressor is based on a new, lifted, orthogonal block transform and embedded coding, allowing each per-block bit stream to be truncated at any point if desired, thus facilitating bit rate selection using a single compression scheme. To avoid compression or decompression upon every data access, we employ a software write-back cache of uncompressed blocks. Our compressor has been designed with computational simplicity and speed in mind to allow for the possibility of a hardware implementation, and uses only a small number of fixed-point arithmetic operations per compressed value. We demonstrate the viability and benefits of lossy compression in several applications, including visualization, quantitative data analysis, and numerical simulation. PMID:26356981

  19. Floating-point function generation routines for 16-bit microcomputers

    NASA Technical Reports Server (NTRS)

    Mackin, M. A.; Soeder, J. F.

    1984-01-01

    Several computer subroutines have been developed that interpolate three types of nonanalytic functions: univariate, bivariate, and map. The routines use data in floating-point form. However, because they are written for use on a 16-bit Intel 8086 system with an 8087 mathematical coprocessor, they execute as fast as routines using data in scaled integer form. Although all of the routines are written in assembly language, they have been implemented in a modular fashion so as to facilitate their use with high-level languages.

  20. Double-Precision Floating-Point Cores V1.9

    SciTech Connect

    Govindu, Gokul; Scrofano, Ronald

    2005-10-15

    In studying the acceleration of scientific computing applications with reconfigurable hardware, such as field programmable gate arrays, one finds that many scientific applications require high-precision, floating-point arithmetic that is not innately supported in reconfigurable hardware. Consequently, we have written VDL code that describes hardware for performing double-precision (64-bit) floating-point arithmetic. From this code, it is possible for users to implement double-precision floating-point operations on FPGAs or any other hardware device to which VHDL code can be synthesized. Specifically, we have written code for four floating-point cores. Each core performs one operation: one performs addition/subtraction, one performs multiplication, one performs division, and one performs square root. The code includes parameters that determine the features of the floating-point cores, such as what types of floating-point numbers are supported and what roudning modes are supported. These parameters influence the frequency achievable by the designs as well as the chip area required for the designs. The parameters are chosen so that the floating-point cores have varyinig amounts of compliance with the industry standard for floating-point cores have varying amounts of compliance with the industry standard for floating-point arithmetic, IEEE standard 754. There is an additional parameter that determines the number of pipelining stages in the floating-point cores.

  1. Double-Precision Floating-Point Cores V1.9

    Energy Science and Technology Software Center (ESTSC)

    2005-10-15

    In studying the acceleration of scientific computing applications with reconfigurable hardware, such as field programmable gate arrays, one finds that many scientific applications require high-precision, floating-point arithmetic that is not innately supported in reconfigurable hardware. Consequently, we have written VDL code that describes hardware for performing double-precision (64-bit) floating-point arithmetic. From this code, it is possible for users to implement double-precision floating-point operations on FPGAs or any other hardware device to which VHDL code canmore » be synthesized. Specifically, we have written code for four floating-point cores. Each core performs one operation: one performs addition/subtraction, one performs multiplication, one performs division, and one performs square root. The code includes parameters that determine the features of the floating-point cores, such as what types of floating-point numbers are supported and what roudning modes are supported. These parameters influence the frequency achievable by the designs as well as the chip area required for the designs. The parameters are chosen so that the floating-point cores have varyinig amounts of compliance with the industry standard for floating-point cores have varying amounts of compliance with the industry standard for floating-point arithmetic, IEEE standard 754. There is an additional parameter that determines the number of pipelining stages in the floating-point cores.« less

  2. Floating point only SIMD instruction set architecture including compare, select, Boolean, and alignment operations

    DOEpatents

    Gschwind, Michael K.

    2011-03-01

    Mechanisms for implementing a floating point only single instruction multiple data instruction set architecture are provided. A processor is provided that comprises an issue unit, an execution unit coupled to the issue unit, and a vector register file coupled to the execution unit. The execution unit has logic that implements a floating point (FP) only single instruction multiple data (SIMD) instruction set architecture (ISA). The floating point vector registers of the vector register file store both scalar and floating point values as vectors having a plurality of vector elements. The processor may be part of a data processing system.

  3. Error bounds on complex floating-point multiplication

    NASA Astrophysics Data System (ADS)

    Brent, Richard; Percival, Colin; Zimmermann, Paul

    2007-09-01

    Given floating-point arithmetic with t -digit base- beta significands in which all arithmetic operations are performed as if calculated to infinite precision and rounded to a nearest representable value, we prove that the product of complex values z_0 and z_1 can be computed with maximum absolute error \\vert z_0Vert z_1\\vert frac{1}{2} beta^{1 - t} sqrt{5} . In particular, this provides relative error bounds of 2^{-24} sqrt{5} and 2^{-53} sqrt{5} for IEEE 754 single and double precision arithmetic respectively, provided that overflow, underflow, and denormals do not occur. We also provide the numerical worst cases for IEEE 754 single and double precision arithmetic.

  4. Floating point fault tolerance with backward error assertions

    SciTech Connect

    Boley, D.; Golub, G.H.; Makar, S.; Saxena, N.; Mccluskey, E.J.

    1995-02-01

    This paper introduces an assertion scheme based on the backward error analysis for error detection in algorithms that solve dense systems of linear equations, Ax = b. Unlike previous methods, this Backward Error Assertion Model is specifically designed to operate in an environment of floating point arithmetic subject to round-off errors, and it can be easily instrumented in a Watchdog processor environment. The complexity of verifying assertions is Omicron (n(sup 2)), compared to the Omicron (n(sup 3)) complexity of algorithms solving Ax = b. Unlike other proposed error detection methods, this assertion model does not require any encoding of the matrix A. Experimental results under various error models are presented to validate the effectiveness of this assertion scheme. 22 refs.

  5. Fixed-rate compressed floating-point arrays

    Energy Science and Technology Software Center (ESTSC)

    2014-03-30

    ZFP is a library for lossy compression of single- and double-precision floating-point data. One of the unique features of ZFP is its support for fixed-rate compression, which enables random read and write access at the granularity of small blocks of values. Using a C++ interface, this allows declaring compressed arrays (1D, 2D, and 3D arrays are supported) that through operator overloading can be treated just like conventional, uncompressed arrays, but which allow the user tomore » specify the exact number of bits to allocate to the array. ZFP also has variable-rate fixed-precision and fixed-accuracy modes, which allow the user to specify a tolerance on the relative or absolute error.« less

  6. The complexity of class polynomial computation via floating point approximations

    NASA Astrophysics Data System (ADS)

    Enge, Andreas

    2009-06-01

    We analyse the complexity of computing class polynomials, that are an important ingredient for CM constructions of elliptic curves, via complex floating point approximations of their roots. The heart of the algorithm is the evaluation of modular functions in several arguments. The fastest one of the presented approaches uses a technique devised by Dupont to evaluate modular functions by Newton iterations on an expression involving the arithmetic-geometric mean. Under the heuristic assumption, justified by experiments, that the correctness of the result is not perturbed by rounding errors, the algorithm runs in time O left( sqrt {\\vert D\\vert} log^3 \\vert D\\vert M left( sq... ...arepsilon} \\vert D\\vert right) subseteq O left( h^{2 + \\varepsilon} right) for any \\varepsilon > 0 , where D is the CM discriminant, h is the degree of the class polynomial and M (n) is the time needed to multiply two n -bit numbers. Up to logarithmic factors, this running time matches the size of the constructed polynomials. The estimate also relies on a new result concerning the complexity of enumerating the class group of an imaginary quadratic order and on a rigorously proven upper bound for the height of class polynomials.

  7. Floating-point performance of ARM cores and their efficiency in classical molecular dynamics

    NASA Astrophysics Data System (ADS)

    Nikolskiy, V.; Stegailov, V.

    2016-02-01

    Supercomputing of the exascale era is going to be inevitably limited by power efficiency. Nowadays different possible variants of CPU architectures are considered. Recently the development of ARM processors has come to the point when their floating point performance can be seriously considered for a range of scientific applications. In this work we present the analysis of the floating point performance of the latest ARM cores and their efficiency for the algorithms of classical molecular dynamics.

  8. Floating point software package for use on LSI-11 computers at SLAC

    SciTech Connect

    Hendra, R.G.

    1981-06-01

    A floating point software package has been devised to allow full use of the floating point hardware of the LSI-11 and MODEL40 computers. The procedures are written for the most part in the PL-11 language. The package may be run under the RT-11 operating system, or in RAM or EPROM as part of the KERNEL package. The current set of procedures has been run successfully in all three modes.

  9. Generating and executing programs for a floating point single instruction multiple data instruction set architecture

    DOEpatents

    Gschwind, Michael K

    2013-04-16

    Mechanisms for generating and executing programs for a floating point (FP) only single instruction multiple data (SIMD) instruction set architecture (ISA) are provided. A computer program product comprising a computer recordable medium having a computer readable program recorded thereon is provided. The computer readable program, when executed on a computing device, causes the computing device to receive one or more instructions and execute the one or more instructions using logic in an execution unit of the computing device. The logic implements a floating point (FP) only single instruction multiple data (SIMD) instruction set architecture (ISA), based on data stored in a vector register file of the computing device. The vector register file is configured to store both scalar and floating point values as vectors having a plurality of vector elements.

  10. Floating-Point Units and Algorithms for field-programmable gate arrays

    SciTech Connect

    Underwood, Keith D.; Hemmert, K. Scott

    2005-11-01

    The software that we are attempting to copyright is a package of floating-point unit descriptions and example algorithm implementations using those units for use in FPGAs. The floating point units are best-in-class implementations of add, multiply, divide, and square root floating-point operations. The algorithm implementations are sample (not highly flexible) implementations of FFT, matrix multiply, matrix vector multiply, and dot product. Together, one could think of the collection as an implementation of parts of the BLAS library or something similar to the FFTW packages (without the flexibility) for FPGAs. Results from this work has been published multiple times and we are working on a publication to discuss the techniques we use to implement the floating-point units, For some more background, FPGAS are programmable hardware. "Programs" for this hardware are typically created using a hardware description language (examples include Verilog, VHDL, and JHDL). Our floating-point unit descriptions are written in JHDL, which allows them to include placement constraints that make them highly optimized relative to some other implementations of floating-point units. Many vendors (Nallatech from the UK, SRC Computers in the US) have similar implementations, but our implementations seem to be somewhat higher performance. Our algorithm implementations are written in VHDL and models of the floating-point units are provided in VHDL as well. FPGA "programs" make multiple "calls" (hardware instantiations) to libraries of intellectual property (IP), such as the floating-point unit library described here. These programs are then compiled using a tool called a synthesizer (such as a tool from Synplicity, Inc.). The compiled file is a netlist of gates and flip-flops. This netlist is then mapped to a particular type of FPGA by a mapper and then a place- and-route tool. These tools assign the gates in the netlist to specific locations on the specific type of FPGA chip used and

  11. A High-Level Formalization of Floating-Point Number in PVS

    NASA Technical Reports Server (NTRS)

    Boldo, Sylvie; Munoz, Cesar

    2006-01-01

    We develop a formalization of floating-point numbers in PVS based on a well-known formalization in Coq. We first describe the definitions of all the needed notions, e.g., floating-point number, format, rounding modes, etc.; then, we present an application to polynomial evaluation for elementary function evaluation. The application already existed in Coq, but our formalization shows a clear improvement in the quality of the result due to the automation provided by PVS. We finally integrate our formalization into a PVS hardware-level formalization of the IEEE-854 standard previously developed at NASA.

  12. Floating-Point Units and Algorithms for field-programmable gate arrays

    Energy Science and Technology Software Center (ESTSC)

    2005-11-01

    The software that we are attempting to copyright is a package of floating-point unit descriptions and example algorithm implementations using those units for use in FPGAs. The floating point units are best-in-class implementations of add, multiply, divide, and square root floating-point operations. The algorithm implementations are sample (not highly flexible) implementations of FFT, matrix multiply, matrix vector multiply, and dot product. Together, one could think of the collection as an implementation of parts of themore » BLAS library or something similar to the FFTW packages (without the flexibility) for FPGAs. Results from this work has been published multiple times and we are working on a publication to discuss the techniques we use to implement the floating-point units, For some more background, FPGAS are programmable hardware. "Programs" for this hardware are typically created using a hardware description language (examples include Verilog, VHDL, and JHDL). Our floating-point unit descriptions are written in JHDL, which allows them to include placement constraints that make them highly optimized relative to some other implementations of floating-point units. Many vendors (Nallatech from the UK, SRC Computers in the US) have similar implementations, but our implementations seem to be somewhat higher performance. Our algorithm implementations are written in VHDL and models of the floating-point units are provided in VHDL as well. FPGA "programs" make multiple "calls" (hardware instantiations) to libraries of intellectual property (IP), such as the floating-point unit library described here. These programs are then compiled using a tool called a synthesizer (such as a tool from Synplicity, Inc.). The compiled file is a netlist of gates and flip-flops. This netlist is then mapped to a particular type of FPGA by a mapper and then a place- and-route tool. These tools assign the gates in the netlist to specific locations on the specific type of FPGA chip used

  13. Performance of FORTRAN floating-point operations on the Flex/32 multicomputer

    NASA Technical Reports Server (NTRS)

    Crockett, Thomas W.

    1987-01-01

    A series of experiments has been run to examine the floating-point performance of FORTRAN programs on the Flex/32 (Trademark) computer. The experiments are described, and the timing results are presented. The time required to execute a floating-point operation is found to vary considerbaly depending on a number of factors. One factor of particular interest from an algorithm design standpoint is the difference in speed between common memory accesses and local memory accesses. Common memory accesses were found to be slower, and guidelines are given for determinig when it may be cost effective to copy data from common to local memory.

  14. Software Aspects of IEEE Floating-Point Computations for Numerical Applications in High Energy Physics

    SciTech Connect

    2010-05-11

    Floating-point computations are at the heart of much of the computing done in high energy physics. The correctness, speed and accuracy of these computations are of paramount importance. The lack of any of these characteristics can mean the difference between new, exciting physics and an embarrassing correction. This talk will examine practical aspects of IEEE 754-2008 floating-point arithmetic as encountered in HEP applications. After describing the basic features of IEEE floating-point arithmetic, the presentation will cover: common hardware implementations (SSE, x87) techniques for improving the accuracy of summation, multiplication and data interchange compiler options for gcc and icc affecting floating-point operations hazards to be avoided About the speaker Jeffrey M Arnold is a Senior Software Engineer in the Intel Compiler and Languages group at Intel Corporation. He has been part of the Digital->Compaq->Intel compiler organization for nearly 20 years; part of that time, he worked on both low- and high-level math libraries. Prior to that, he was in the VMS Engineering organization at Digital Equipment Corporation. In the late 1980s, Jeff spent 2½ years at CERN as part of the CERN/Digital Joint Project. In 2008, he returned to CERN to spent 10 weeks working with CERN/openlab. Since that time, he has returned to CERN multiple times to teach at openlab workshops and consult with various LHC experiments. Jeff received his Ph.D. in physics from Case Western Reserve University.

  15. Software Aspects of IEEE Floating-Point Computations for Numerical Applications in High Energy Physics

    ScienceCinema

    None

    2011-10-06

    Floating-point computations are at the heart of much of the computing done in high energy physics. The correctness, speed and accuracy of these computations are of paramount importance. The lack of any of these characteristics can mean the difference between new, exciting physics and an embarrassing correction. This talk will examine practical aspects of IEEE 754-2008 floating-point arithmetic as encountered in HEP applications. After describing the basic features of IEEE floating-point arithmetic, the presentation will cover: common hardware implementations (SSE, x87) techniques for improving the accuracy of summation, multiplication and data interchange compiler options for gcc and icc affecting floating-point operations hazards to be avoided About the speaker Jeffrey M Arnold is a Senior Software Engineer in the Intel Compiler and Languages group at Intel Corporation. He has been part of the Digital->Compaq->Intel compiler organization for nearly 20 years; part of that time, he worked on both low- and high-level math libraries. Prior to that, he was in the VMS Engineering organization at Digital Equipment Corporation. In the late 1980s, Jeff spent 2½ years at CERN as part of the CERN/Digital Joint Project. In 2008, he returned to CERN to spent 10 weeks working with CERN/openlab. Since that time, he has returned to CERN multiple times to teach at openlab workshops and consult with various LHC experiments. Jeff received his Ph.D. in physics from Case Western Reserve University.

  16. RANS Simulation of the Heave Response of a Two-Body Floating Point Wave Absorber: Preprint

    SciTech Connect

    Yu, Y.; Li, Y.

    2011-03-01

    A preliminary study on a two-body floating wave absorbers is presented in this paper. A Reynolds-Averaged Navier-Stokes computational method is applied for analyzing the hydrodynamic heave response of the absorber in operational wave conditions. The two-body floating wave absorber contains a float section and a submerged reaction section. For validation purposes, our model is first assumed to be locked. The two sections are forced to move together with each other. The locked single body model is used in a heave decay test, where the RANS result is validated with the experimental measurement. For the two-body floating point absorber simulation, the two sections are connected through a mass-spring-damper system, which is applied to simulate the power take-off mechanism under design wave conditions. Overall, the details of the flow around the absorber and its nonlinear interaction with waves are investigated, and the power absorption efficiency of the two-body floating wave absorber in waves with a constant value spring-damper system is examined.

  17. A device to improve the SNR of the measurement of the positional floating reference point

    NASA Astrophysics Data System (ADS)

    Jiang, Jingying; Rong, Xuzheng; Zhang, Hao; Xu, Kexin

    2013-02-01

    Previous studies have preliminarily validated the floating reference method and shown that it has the potential to improve the accuracy of non-invasive blood glucose sensing by Near-Infrared Spectroscopy. In order to make this method practical, it is necessary to precisely verify and measure the existence and variation features of the positional floating reference point. In this talk, a device which can precisely verify and measure the positional floating reference point is built. Since the light intensity of diffuse reflectance from the tested sample is very weak, a multipath detecting fibers system was built to improve signal-to-noise ratio. In this system, the fibers encircle the light source fiber which is regarded as the reference center of detecting fibers while they are moving. In addition, the position of each fiber is accurately controlled by manual translation stage to keep all detecting fibers always in the same radius around light source fiber. This ensures that received signal is coming from the same radial distance of light source. The variation of signal-to-noise ratio along with the different radial distance was investigated based on experiments. Results show that the application of this device could improve signal-to-noise ratio, and provide a new experimental method for the further study of positional floating reference point.

  18. An analysis of the double-precision floating-point FFT on FPGAs.

    SciTech Connect

    Hemmert, K. Scott; Underwood, Keith Douglas

    2005-01-01

    Advances in FPGA technology have led to dramatic improvements in double precision floating-point performance. Modern FPGAs boast several GigaFLOPs of raw computing power. Unfortunately, this computing power is distributed across 30 floating-point units with over 10 cycles of latency each. The user must find two orders of magnitude more parallelism than is typically exploited in a single microprocessor; thus, it is not clear that the computational power of FPGAs can be exploited across a wide range of algorithms. This paper explores three implementation alternatives for the fast Fourier transform (FFT) on FPGAs. The algorithms are compared in terms of sustained performance and memory requirements for various FFT sizes and FPGA sizes. The results indicate that FPGAs are competitive with microprocessors in terms of performance and that the 'correct' FFT implementation varies based on the size of the transform and the size of the FPGA.

  19. Constrained Chebyshev approximations to some elementary functions suitable for evaluation with floating point arithmetic

    NASA Technical Reports Server (NTRS)

    Manos, P.; Turner, L. R.

    1972-01-01

    Approximations which can be evaluated with precision using floating-point arithmetic are presented. The particular set of approximations thus far developed are for the function TAN and the functions of USASI FORTRAN excepting SQRT and EXPONENTIATION. These approximations are, furthermore, specialized to particular forms which are especially suited to a computer with a small memory, in that all of the approximations can share one general purpose subroutine for the evaluation of a polynomial in the square of the working argument.

  20. Interpretation of IEEE-854 floating-point standard and definition in the HOL system

    NASA Technical Reports Server (NTRS)

    Carreno, Victor A.

    1995-01-01

    The ANSI/IEEE Standard 854-1987 for floating-point arithmetic is interpreted by converting the lexical descriptions in the standard into mathematical conditional descriptions organized in tables. The standard is represented in higher-order logic within the framework of the HOL (Higher Order Logic) system. The paper is divided in two parts with the first part the interpretation and the second part the description in HOL.

  1. Real-time 2D floating-point fast Fourier transforms for seeker simulation

    NASA Astrophysics Data System (ADS)

    Chamberlain, Richard; Lord, Eric; Shand, David J.

    2002-07-01

    The floating point Fast Fourier Transform (FFT) is one of the most useful basic functions available to the image and signal processing engineer allowing many complex and detailed special functions to be implemented more simply in the frequency domain. In the Hardware-in-the-Loop field an image transformed using FFT would allow the designer to think about accurate frequency based simulation of seeker lens effects, motion blur, detector transfer functions and much more. Unfortunately, the transform requires many hundreds of thousands or millions of floating point operations on a single modest sized image making it impractical for realtime Hardware-in-the-Loop systems. .until now. This paper outlines the development, by Nallatech, of an FPGA based IEEE floating point core. It traces the subsequent use of this core to develop a full 256 X 256 FFT and filter process implemented on COTS hardware at frame rates up to 150Hz. This transform can be demonstrated to model optical transfer functions at a far greater accuracy than the current spatial models. Other applications and extensions of this technique will be discussed such as filtering for image tracking algorithms and in the simulation of radar processing in the frequency domain.

  2. Experimental Investigation of the Power Generation Performance of Floating-Point Absorber Wave Energy Systems: Preprint

    SciTech Connect

    Li, Y.; Yu, Y.; Epler, J.; Previsic, M.

    2012-04-01

    The extraction of energy from ocean waves has gained interest in recent years. The floating-point absorber (FPA) is one of the most promising devices among a wide variety of wave energy conversion technologies. Early theoretical studies mainly focused on understanding the hydrodynamics of the system and on predicting the maximum power that could be extracted by a heaving body. These studies evolve from the investigation of floating-body interactions in offshore engineering and naval architecture disciplines. To our best knowledge, no systematic study has been reported about the investigation of the power generation performance of an FPA with a close-to-commercial design. A series of experimental tests was conducted to investigate the power extraction performance of an FPA system.

  3. Application of a floating point systems AP190L array processor to finite element analysis

    SciTech Connect

    Young, R.C.

    1982-04-01

    This report discusses the implementation of a finite element program on a Floating Point Systems AP190L array processor attached to a Univac 1182 host computer. The array processor was used to perform all calculations on the global system of linear equations including matrix assembly, matrix factoring and vector solution. A large scratch disk was attached directly to the array processor for storing the factored matrix. The remaining calculations, including data preparation, element matrix formation, stress integration and output display were performed by the host computer.

  4. Evaluation of floating-point sum or difference of products in carry-save domain

    NASA Technical Reports Server (NTRS)

    Wahab, A.; Erdogan, S.; Premkumar, A. B.

    1992-01-01

    An architecture to evaluate a 24-bit floating-point sum or difference of products using modified sequential carry-save multipliers with extensive pipelining is described. The basic building block of the architecture is a carry-save multiplier with built-in mantissa alignment for the summation during the multiplication cycles. A carry-save adder, capable of mantissa alignment, correctly positions products with the current carry-save sum. Carry propagation in individual multipliers is avoided and is only required once to produce the final result.

  5. Lithium-ion drifting: Application to the study of point defects in floating-zone silicon

    NASA Technical Reports Server (NTRS)

    Walton, J. T.; Wong, Y. K.; Zulehner, W.

    1997-01-01

    The use of lithium-ion (Li(+)) drifting to study the properties of point defects in p-type Floating-Zone (FZ) silicon crystals is reported. The Li(+) drift technique is used to detect the presence of vacancy-related defects (D defects) in certain p-type FZ silicon crystals. SUPREM-IV modeling suggests that the silicon point defect diffusivities are considerably higher than those commonly accepted, but are in reasonable agreement with values recently proposed. These results demonstrate the utility of Li(+) drifting in the study of silicon point defect properties in p-type FZ crystals. Finally, a straightforward measurement of the Li(+) compensation depth is shown to yield estimates of the vacancy-related defect concentration in p-type FZ crystals.

  6. Numerical simulation of point defect transport in floating-zone silicon single crystal growth

    NASA Astrophysics Data System (ADS)

    Larsen, T. L.; Jensen, L.; Lüdge, A.; Riemann, H.; Lemke, H.

    2001-08-01

    This work compares simulations of intrinsic point defect transport for a 0.8″ crystal for two different values of the point defect recombination factor, thereafter utilizing the model for two more commercially relevant 4″ crystals, grown with the needle-eye technique. Using this approach to study defect transport in floating-zone configurations is the novelty of this work. The simulation of the thin 0.8″ crystal is compared to the qualitative Voronkov model and DLTS experiments, to give some insights on the applied recombination factors. The work concludes that for large crystals, grown in the vacancy region, the influence of an uncertain recombination factor is not as significant as for smaller crystals grown with a near critical growth parameter.

  7. Parametric study of two-body floating-point wave absorber

    NASA Astrophysics Data System (ADS)

    Amiri, Atena; Panahi, Roozbeh; Radfar, Soheil

    2016-03-01

    In this paper, we present a comprehensive numerical simulation of a point wave absorber in deep water. Analyses are performed in both the frequency and time domains. The converter is a two-body floating-point absorber (FPA) with one degree of freedom in the heave direction. Its two parts are connected by a linear mass-spring-damper system. The commercial ANSYS-AQWA software used in this study performs well in considering validations. The velocity potential is obtained by assuming incompressible and irrotational flow. As such, we investigated the effects of wave characteristics on energy conversion and device efficiency, including wave height and wave period, as well as the device diameter, draft, geometry, and damping coefficient. To validate the model, we compared our numerical results with those from similar experiments. Our study results can clearly help to maximize the converter's efficiency when considering specific conditions.

  8. Quantifying the Impact of Single Bit Flips on Floating Point Arithmetic

    SciTech Connect

    Elliott, James J; Mueller, Frank; Stoyanov, Miroslav K; Webster, Clayton G

    2013-08-01

    In high-end computing, the collective surface area, smaller fabrication sizes, and increasing density of components have led to an increase in the number of observed bit flips. If mechanisms are not in place to detect them, such flips produce silent errors, i.e. the code returns a result that deviates from the desired solution by more than the allowed tolerance and the discrepancy cannot be distinguished from the standard numerical error associated with the algorithm. These phenomena are believed to occur more frequently in DRAM, but logic gates, arithmetic units, and other circuits are also susceptible to bit flips. Previous work has focused on algorithmic techniques for detecting and correcting bit flips in specific data structures, however, they suffer from lack of generality and often times cannot be implemented in heterogeneous computing environment. Our work takes a novel approach to this problem. We focus on quantifying the impact of a single bit flip on specific floating-point operations. We analyze the error induced by flipping specific bits in the most widely used IEEE floating-point representation in an architecture-agnostic manner, i.e., without requiring proprietary information such as bit flip rates and the vendor-specific circuit designs. We initially study dot products of vectors and demonstrate that not all bit flips create a large error and, more importantly, expected value of the relative magnitude of the error is very sensitive on the bit pattern of the binary representation of the exponent, which strongly depends on scaling. Our results are derived analytically and then verified experimentally with Monte Carlo sampling of random vectors. Furthermore, we consider the natural resilience properties of solvers based on the fixed point iteration and we demonstrate how the resilience of the Jacobi method for linear equations can be significantly improved by rescaling the associated matrix.

  9. FloPSy - Search-Based Floating Point Constraint Solving for Symbolic Execution

    NASA Astrophysics Data System (ADS)

    Lakhotia, Kiran; Tillmann, Nikolai; Harman, Mark; de Halleux, Jonathan

    Recently there has been an upsurge of interest in both, Search-Based Software Testing (SBST), and Dynamic Symbolic Execution (DSE). Each of these two approaches has complementary strengths and weaknesses, making it a natural choice to explore the degree to which the strengths of one can be exploited to offset the weakness of the other. This paper introduces an augmented version of DSE that uses a SBST-based approach to handling floating point computations, which are known to be problematic for vanilla DSE. The approach has been implemented as a plug in for the Microsoft Pex DSE testing tool. The paper presents results from both, standard evaluation benchmarks, and two open source programs.

  10. High-Precision Floating-Point Arithmetic in ScientificComputation

    SciTech Connect

    Bailey, David H.

    2004-12-31

    At the present time, IEEE 64-bit floating-point arithmetic is sufficiently accurate for most scientific applications. However, for a rapidly growing body of important scientific computing applications, a higher level of numeric precision is required: some of these applications require roughly twice this level; others require four times; while still others require hundreds or more digits to obtain numerically meaningful results. Such calculations have been facilitated by new high-precision software packages that include high-level language translation modules to minimize the conversion effort. These activities have yielded a number of interesting new scientific results in fields as diverse as quantum theory, climate modeling and experimental mathematics, a few of which are described in this article. Such developments suggest that in the future, the numeric precision used for a scientific computation may be as important to the program design as are the algorithms and data structures.

  11. Real-time IP-hologram conversion hardware based on floating point DSPs

    NASA Astrophysics Data System (ADS)

    Oi, Ryutaro; Mishina, Tomoyuki; Yamamoto, Kenji; Okui, Makoto

    2009-02-01

    Holography is a 3-D display method that fully satisfies the visual characteristics of the human eye. However, the hologram must be developed in a darkroom under laser illumination. We attempted hologram generation under white light by adopting an integral photography (IP) technique as the input. In this research, we developed a hardware converter to convert IP input (with 120×66 elemental images) to a hologram with high definition television (HDTV) resolution (approximately 2 million pixels). This conversion could be carried out in real time. In this conversion method, each elemental image can be independently extracted and processed. Our hardware contains twenty 300-MHz floating-point digital signal processors (DSPs) operating in parallel. We verified real-time conversion operations by the implemented hardware.

  12. Interferometric synthetic aperture microscopy implementation on a floating point multi-core digital signal processer

    NASA Astrophysics Data System (ADS)

    Ahmad, Adeel; Ali, Murtaza; South, Fredrick; Monroy, Guillermo L.; Adie, Steven G.; Shemonski, Nathan; Carney, P. Scott; Boppart, Stephen A.

    2013-03-01

    The transition of optical coherence tomography (OCT) technology from the lab environment towards the more challenging clinical and point-of-care settings is continuing at a rapid pace. On one hand this translation opens new opportunities and avenues for growth, while on the other hand it also presents a new set of challenges and constraints under which OCT systems have to operate. OCT systems in the clinical environment are not only required to be user friendly and easy to operate, but should also be portable, have a smaller form factor coupled with low cost and reduced power consumption. Digital signal processors (DSP) are in a unique position to satisfy the computational requirements for OCT at a much lower cost and power consumption compared to the existing platforms such as CPU and graphics processing units (GPUs). In this work, we describe the implementation of optical coherence tomography (OCT) and interferometric synthetic aperture microscopy (ISAM) processing on a floating point multi-core DSP (C6678, Texas Instruments). ISAM is a computationally intensive data processing technique that is based on the re-sampling of the Fourier space of the data to yield spatially invariant transverse resolution in OCT. Preliminary results indicate that 2DISAM processing at 70,000 A-lines/sec and OCT at 180,000 A-lines/sec can be achieved with the current implementation using available DSP hardware.

  13. Optimal Compression of Floating-Point Astronomical Images Without Significant Loss of Information

    NASA Technical Reports Server (NTRS)

    Pence, William D.; White, R. L.; Seaman, R.

    2010-01-01

    We describe a compression method for floating-point astronomical images that gives compression ratios of 6 - 10 while still preserving the scientifically important information in the image. The pixel values are first preprocessed by quantizing them into scaled integer intensity levels, which removes some of the uncompressible noise in the image. The integers are then losslessly compressed using the fast and efficient Rice algorithm and stored in a portable FITS format file. Quantizing an image more coarsely gives greater image compression, but it also increases the noise and degrades the precision of the photometric and astrometric measurements in the quantized image. Dithering the pixel values during the quantization process greatly improves the precision of measurements in the more coarsely quantized images. We perform a series of experiments on both synthetic and real astronomical CCD images to quantitatively demonstrate that the magnitudes and positions of stars in the quantized images can be measured with the predicted amount of precision. In order to encourage wider use of these image compression methods, we have made available a pair of general-purpose image compression programs, called fpack and funpack, which can be used to compress any FITS format image.

  14. Verification of Numerical Programs: From Real Numbers to Floating Point Numbers

    NASA Technical Reports Server (NTRS)

    Goodloe, Alwyn E.; Munoz, Cesar; Kirchner, Florent; Correnson, Loiec

    2013-01-01

    Numerical algorithms lie at the heart of many safety-critical aerospace systems. The complexity and hybrid nature of these systems often requires the use of interactive theorem provers to verify that these algorithms are logically correct. Usually, proofs involving numerical computations are conducted in the infinitely precise realm of the field of real numbers. However, numerical computations in these algorithms are often implemented using floating point numbers. The use of a finite representation of real numbers introduces uncertainties as to whether the properties veri ed in the theoretical setting hold in practice. This short paper describes work in progress aimed at addressing these concerns. Given a formally proven algorithm, written in the Program Verification System (PVS), the Frama-C suite of tools is used to identify sufficient conditions and verify that under such conditions the rounding errors arising in a C implementation of the algorithm do not affect its correctness. The technique is illustrated using an algorithm for detecting loss of separation among aircraft.

  15. Floating-Point Modules Targeted for Use with RC Compilation Tools

    NASA Technical Reports Server (NTRS)

    Sahin, Ibrahin; Gloster, Clay S.

    2000-01-01

    Reconfigurable Computing (RC) has emerged as a viable computing solution for computationally intensive applications. Several applications have been mapped to RC system and in most cases, they provided the smallest published execution time. Although RC systems offer significant performance advantages over general-purpose processors, they require more application development time than general-purpose processors. This increased development time of RC systems provides the motivation to develop an optimized module library with an assembly language instruction format interface for use with future RC system that will reduce development time significantly. In this paper, we present area/performance metrics for several different types of floating point (FP) modules that can be utilized to develop complex FP applications. These modules are highly pipelined and optimized for both speed and area. Using these modules, and example application, FP matrix multiplication, is also presented. Our results and experiences show, that with these modules, 8-10X speedup over general-purpose processors can be achieved.

  16. Toward a formal verification of a floating-point coprocessor and its composition with a central processing unit

    NASA Technical Reports Server (NTRS)

    Pan, Jing; Levitt, Karl N.; Cohen, Gerald C.

    1991-01-01

    Discussed here is work to formally specify and verify a floating point coprocessor based on the MC68881. The HOL verification system developed at Cambridge University was used. The coprocessor consists of two independent units: the bus interface unit used to communicate with the cpu and the arithmetic processing unit used to perform the actual calculation. Reasoning about the interaction and synchronization among processes using higher order logic is demonstrated.

  17. Desirable floating-point arithmetic and elementary functions for numerical computation

    NASA Technical Reports Server (NTRS)

    Hull, T. E.

    1978-01-01

    The topics considered are: (1) the base of the number system, (2) precision control, (3) number representation, (4) arithmetic operations, (5) other basic operations, (6) elementary functions, and (7) exception handling. The possibility of doing without fixed-point arithmetic is also mentioned. The specifications are intended to be entirely at the level of a programming language such as FORTRAN. The emphasis is on convenience and simplicity from the user's point of view. Conforming to such specifications would have obvious beneficial implications for the portability of numerical software, and for proving programs correct, as well as attempting to provide facilities which are most suitable for the user. The specifications are not complete in every detail, but it is intended that they be complete in spirit - some further details, especially syntatic details, would have to be provided, but the proposals are otherwise relatively complete.

  18. Development of the Kalman filter application and a VHDL model for the AFIT (Air Force Institute of Technology) Floating Point Application Specific Processor (FPASP)

    NASA Astrophysics Data System (ADS)

    Koch, William E.

    1989-12-01

    The Air Force Institute of Technology (AFIT) is conducting research that will lead to the development of a Floating Point application Specific Processor (FPASP). The FPASP architecture is designed around two independent 32 bit data paths that work in tandem to support full IEEE double precision floating point operations, or that can work independently for 32 bit integer processing. Designed to operate at 25 MHz, the FPASP will be capable of performing 25 million floating point operations per second. A rapid prototyping methodology has been developed for the FPASP. A user identifies an application that could benefit from a VLSI solution. An algorithm of the application is translated into FPASP microcode which can then be programmed into the Laser Programmable Read Only Memory (LPROM) of a blank FPASP. The programmed FPASP can then be mounted on a circuit card and installed in a host system where it would function as a hardware accelerator supporting the user application. In the first part of this thesis, a user application, the Kalman Filter algorithm, is translated into FPASP microcode for programming into the FPASP. In part two, the feasibility of using the VHSIC (Very High Speed Integrated Circuitry) Hardware Design Language (VHDL) to model a complete system is demonstrated by developing a register transfer level model of the FPASP.

  19. Implementation of the DAST ARW II control laws using an 8086 microprocessor and an 8087 floating-point coprocessor. [drones for aeroelasticity research

    NASA Technical Reports Server (NTRS)

    Kelly, G. L.; Berthold, G.; Abbott, L.

    1982-01-01

    A 5 MHZ single-board microprocessor system which incorporates an 8086 CPU and an 8087 Numeric Data Processor is used to implement the control laws for the NASA Drones for Aerodynamic and Structural Testing, Aeroelastic Research Wing II. The control laws program was executed in 7.02 msec, with initialization consuming 2.65 msec and the control law loop 4.38 msec. The software emulator execution times for these two tasks were 36.67 and 61.18, respectively, for a total of 97.68 msec. The space, weight and cost reductions achieved in the present, aircraft control application of this combination of a 16-bit microprocessor with an 80-bit floating point coprocessor may be obtainable in other real time control applications.

  20. Stools - floating

    MedlinePlus

    ... absorption of nutrients ( malabsorption ) or too much gas (flatulence). Considerations Most causes of floating stools are harmless. ... Bailey J. FPIN's Clinical Inquiries: Effective management of flatulence. Am Fam Physician Ohge H, Levitt MD. Intestinal ...

  1. 40 CFR 426.50 - Applicability; description of the float glass manufacturing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... float glass manufacturing subcategory. 426.50 Section 426.50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Float Glass Manufacturing Subcategory § 426.50 Applicability; description of the float...

  2. 40 CFR 426.50 - Applicability; description of the float glass manufacturing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... float glass manufacturing subcategory. 426.50 Section 426.50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Float Glass Manufacturing Subcategory § 426.50 Applicability; description of the float...

  3. Tank Tests of Twin Seaplane Floats

    NASA Technical Reports Server (NTRS)

    Herrman, H; Kempf, G; Kloess, H

    1928-01-01

    The following report contains the most essential data for the hydrodynamic portion of the twin-float problem. The following points were successfully investigated: 1) difference between stationary and nonstationary flow; 2) effect of the shape of the step; 3) effect of distance between floats; 4) effect of nose-heavy and tail-heavy moments; 5) effect of the shape of floats; 6) maneuverability.

  4. WindWaveFloat

    SciTech Connect

    Weinstein, Alla

    2011-11-01

    Presentation from the 2011 Water Peer Review includes in which principal investigator Alla Weinstein discusses project progress in development of a floating offshore wind structure - the WindFloat - and incorporation therin of a Spherical Wave Energy Device.

  5. Floating: sink or swim.

    PubMed

    Pronger, L

    1995-12-01

    Budget restrictions, fewer human resources and fluctuating patient populations have combined to increase the practice of floating general duty nurses. Floating occurs when a nurse from an overstaffed unit, based on patient load, is required to work in another unit that is understaffed. Floating is not a new practice, but it has always been an emotionally charged issue. Today, with more float pool nurses seeking the security of a permanent position in a home unit, the issue has increased in intensity. PMID:8713148

  6. The Design of Floats

    NASA Technical Reports Server (NTRS)

    Sottorf, W

    1938-01-01

    Following a summary of the multiplicity of domestic and foreign floats and a brief enumeration of the requirements of floats, the essential form parameters and their effect on the qualities of floats are detailed. On this basis a standard float design is developed which in model families with varying length/beam ratio and angle of dead rise is analyzed by an experimental method which permits its best utilization on any airplane.

  7. "Floating shoulder" injuries.

    PubMed

    Heng, Kenneth

    2016-12-01

    "Floating shoulder" is a rare injury complex resulting from high-energy blunt force trauma to the shoulder, resulting in scapulothoracic dissociation. It is commonly associated with catastrophic neurovascular injury. Two cases of motorcyclists with floating shoulder injuries are described. PMID:26961729

  8. Float Zone Workshop

    NASA Technical Reports Server (NTRS)

    Naumann, R. J.

    1980-01-01

    A summary of the Analytical Float Zone Experiment System (AFZES) concept is presented. The types of experiments considered for such a facility are discussed. Reports from various industrial producers and users of float zone material are presented. Special emphasis is placed on state-of-the-art developments in low gravity manufacturing and their applications to space processing.

  9. Impact on floating membranes

    NASA Astrophysics Data System (ADS)

    Vandenberghe, Nicolas; Duchemin, Laurent

    2016-05-01

    When impacted by a rigid body, a thin elastic membrane with negligible bending rigidity floating on a liquid pool deforms. Two axisymmetric waves radiating from the impact point propagate. First, a longitudinal wave front, associated with in-plane deformation of the membrane and traveling at constant speed, separates an outward stress-free domain from a stretched domain. Then, in the stretched domain a dispersive transverse wave travels at a speed that depends on the local stretching rate. The dynamics is found to be self-similar in time. Using this property, we show that the wave dynamics is similar to the capillary waves that propagate at a liquid-gas interface but with a surface tension coefficient that depends on impact speed. During wave propagation, we observe the development of a buckling instability that gives rise to radial wrinkles. We address the dynamics of this fluid-body system, including the rapid deceleration of an impactor of finite mass, an issue that may have applications in the domain of absorption of impact energy.

  10. Floating emitter solar cell

    NASA Technical Reports Server (NTRS)

    Chih, Sah (Inventor); Cheng, Li-Jen (Inventor)

    1987-01-01

    A front surface contact floating emitter solar cell transistor is provided in a semiconductor body (n-type), in which floating emitter sections (p-type) are diffused or implanted in the front surface. Between the emitter sections, a further section is diffused or implanted in the front surface, but isolated from the floating emitter sections, for use either as a base contact to the n-type semiconductor body, in which case the section is doped n+, or as a collector for the adjacent emitter sections.

  11. Floating Magnet Demonstration.

    ERIC Educational Resources Information Center

    Wake, Masayoshi

    1990-01-01

    A room-temperature demonstration of a floating magnet using a high-temperature superconductor is described. The setup and operation of the apparatus are described. The technical details of the effect are discussed. (CW)

  12. Concrete production floating platforms

    SciTech Connect

    Letourneur, O.; Falcimaigne, J.

    1981-01-01

    The floating production platforms operating in the North Sea are adapted from drilling semisubmersibles which allow only a limited payload capacity. Experience of concrete production platforms constructed for the North Sea has led Sea Tank Co. to propose a floating platform which offers large payload and oil storage capacities similar to those of existing fixed platforms. Sea Tank Co. and Institut Francais du Petrole joined forces in early 1976 to study the feasibility of a concrete floating production platform incorporating the structure and the production riser together. The results of this 3-yr program show that the concrete floating structure is economically attractive for permanent utilization on a production site. Furthermore, concrete has definite advantages over other materials, in its long term behavior.

  13. Float-in powerhouses

    SciTech Connect

    Makela, G.A.

    1983-06-01

    The nation's inland waterway system affords a means of transporting large objects limited only by channel depth, size of locks and bridge clearances. The concept of prefabricating standardized, hydroelectric powerhouses at shipyards, transporting them along the inland waterways and installing them at navigation dams without powerhouses was examined for the McClellan-Kerr Arkansas River Navigation system. It was found that construction costs for the float-in design was very close to those of conventional sitebuilt design. Experience at Greenup Dam on the Ohio River where a float-in powerhouse has been installed indicated that construction time could be reduced if the float-in design was used. This time saving, use of standardized designs and construction of the float-in module at a shipyard may offer advantages that should be examined in more detailed when the power potential of the nation's low navigation dams is assessed.

  14. Micromechanisms with floating pivot

    DOEpatents

    Garcia, Ernest J.

    2001-03-06

    A new class of tilting micromechanical mechanisms have been developed. These new mechanisms use floating pivot structures to relieve some of the problems encountered in the use of solid flexible pivots.

  15. Stabilized floating platforms

    DOEpatents

    Thomas, David G.

    1976-01-01

    The subject invention is directed to a floating platform for supporting nuclear reactors and the like at selected offshore sites. The platform is provided with a stabilizer mechanism which significantly reduces the effects of wave action upon the platform and which comprises a pair of relatively small floats attached by rigid booms to the platform at locations spaced therefrom for reducing wave pitch, acceleration, and the resonance period of the wave.

  16. 40 CFR 426.50 - Applicability; description of the float glass manufacturing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... float glass manufacturing subcategory. 426.50 Section 426.50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) GLASS MANUFACTURING POINT SOURCE CATEGORY Float Glass Manufacturing Subcategory § 426.50 Applicability; description of the float...

  17. 40 CFR 426.50 - Applicability; description of the float glass manufacturing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... float glass manufacturing subcategory. 426.50 Section 426.50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) GLASS MANUFACTURING POINT SOURCE CATEGORY Float Glass Manufacturing Subcategory § 426.50 Applicability; description of the float...

  18. 40 CFR 426.50 - Applicability; description of the float glass manufacturing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... float glass manufacturing subcategory. 426.50 Section 426.50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) GLASS MANUFACTURING POINT SOURCE CATEGORY Float Glass Manufacturing Subcategory § 426.50 Applicability; description of the float...

  19. Floating nut retention system

    NASA Technical Reports Server (NTRS)

    Charles, J. F.; Theakston, H. A. (Inventor)

    1980-01-01

    A floating nut retention system includes a nut with a central aperture. An inner retainer plate has an opening which is fixedly aligned with the nut aperture. An outer retainer member is formed of a base plate having an opening and a surface adjacent to a surface of the inner retainer plate. The outer retainer member includes a securing mechanism for retaining the inner retainer plate adjacent to the outer retainer member. The securing mechanism enables the inner retainer plate to float with respect to the outer retainer number, while simultaneously forming a bearing surface for inner retainer plate.

  20. Tethered float liquid level sensor

    DOEpatents

    Daily, III, William Dean

    2016-09-06

    An apparatus for sensing the level of a liquid includes a float, a tether attached to the float, a pulley attached to the tether, a rotation sensor connected to the pulley that senses vertical movement of said float and senses the level of the liquid.

  1. Compound floating pivot micromechanisms

    DOEpatents

    Garcia, Ernest J.

    2001-04-24

    A new class of tilting micromechanical mechanisms have been developed. These new mechanisms use compound floating pivot structures to attain far greater tilt angles than are practical using other micromechanical techniques. The new mechanisms are also capable of bi-directional tilt about multiple axes.

  2. Floating platform with monolithically formed float members and platform

    SciTech Connect

    Finsterwalder, U.

    1981-06-30

    Floating platforms for various offshore facilities are formed of float members monolithically connected to a superposed platform. The float members are spherically shaped and are formed of reinforced or prestressed concrete. The platform can be a hollow planar member or it can be curved in one or two directions, and the platforms are formed of prestressed concrete. Cylindrical shafts can be used to connect the spherically shaped floats and the platform. Individual floating platforms can be connected by expansion joints and used as a runway. The float members can be constructed at the shoreline, launched into the water and held in a regular pattern while decked over with the platform. After completion of the construction procedure, the floating platform can be moved to an offshore location for use.

  3. Freely floating smectic films.

    PubMed

    May, Kathrin; Harth, Kirsten; Trittel, Torsten; Stannarius, Ralf

    2014-05-19

    We have investigated the dynamics of freely floating smectic bubbles using high-speed optical imaging. Bubbles in the size range from a few hundred micrometers to several centimeters were prepared from collapsing catenoids. They represent ideal model systems for the study of thin-film fluid dynamics under well-controlled conditions. Owing to the internal smectic layer structure, the bubbles combine features of both soap films and vesicles in their unique shape dynamics. From a strongly elongated initial shape after pinch-off, they relax towards the spherical equilibrium, first by a slow redistribution of the smectic layers, and finally by weak, damped shape oscillations. In addition, we describe the rupture of freely floating smectic bubbles, and the formation and stability of smectic filaments. PMID:24692347

  4. Float processing of high-temperature complex silicate glasses and float baths used for same

    NASA Technical Reports Server (NTRS)

    Cooper, Reid Franklin (Inventor); Cook, Glen Bennett (Inventor)

    2000-01-01

    A float glass process for production of high melting temperature glasses utilizes a binary metal alloy bath having the combined properties of a low melting point, low reactivity with oxygen, low vapor pressure, and minimal reactivity with the silicate glasses being formed. The metal alloy of the float medium is exothermic with a solvent metal that does not readily form an oxide. The vapor pressure of both components in the alloy is low enough to prevent deleterious vapor deposition, and there is minimal chemical and interdiffusive interaction of either component with silicate glasses under the float processing conditions. Alloys having the desired combination of properties include compositions in which gold, silver or copper is the solvent metal and silicon, germanium or tin is the solute, preferably in eutectic or near-eutectic compositions.

  5. The Floating Ball Paradox

    NASA Astrophysics Data System (ADS)

    Wente, Henry C.

    2008-11-01

    In capillary theory there are two kinds of surface tension. There is the surface tension at the interface between two immiscible fluids. Thomas Young [9] also allowed for there to be a surface tension associated with a liquid-solid interface. He proceeded to use a balance of forces argument to derive the well-known contact angle condition along a liquid-liquid-solid intersection. The validity of this argument has recently been called into question by R. Finn [6]. A floating ball experiment discussed in that paper leads to an apparent paradox. We address this issue.

  6. Does It Sink or Float?

    ERIC Educational Resources Information Center

    McDonald, Judith Richards

    2012-01-01

    This activity is designed to teach prekindergarten to second grade students about the concept of sink or float through an inquiry activity. Students will use familiar objects to predict and test the properties of sink and float. Background information is offered to teachers to assist them with this activity. This lesson begins with an engaging…

  7. Floating mirror mount

    SciTech Connect

    Koop, D.E.

    1989-01-03

    This patent describes a floating mirror mount for a mirror of a laser is described consisting of: a mirror having a front surface and a back surface, a keeper encircling the mirror and having a peripheral flange engaging the front surface of the mirror when the mirror is not installed in a laser, a retainer positioned rearwardly of the back surface of the mirror and connected to the keeper and having a spring seating surface, spring means engageable with the spring seating surface of the retainer for exerting a resilient biasing force on the mirror, and fastening means for connecting the retainer to the mirror positioning structure of the laser on installation of the mirror mount in the laser.

  8. Floating Silicon Method

    SciTech Connect

    Kellerman, Peter

    2013-12-21

    The Floating Silicon Method (FSM) project at Applied Materials (formerly Varian Semiconductor Equipment Associates), has been funded, in part, by the DOE under a “Photovoltaic Supply Chain and Cross Cutting Technologies” grant (number DE-EE0000595) for the past four years. The original intent of the project was to develop the FSM process from concept to a commercially viable tool. This new manufacturing equipment would support the photovoltaic industry in following ways: eliminate kerf losses and the consumable costs associated with wafer sawing, allow optimal photovoltaic efficiency by producing high-quality silicon sheets, reduce the cost of assembling photovoltaic modules by creating large-area silicon cells which are free of micro-cracks, and would be a drop-in replacement in existing high efficiency cell production process thereby allowing rapid fan-out into the industry.

  9. Floating into Deep Space

    NASA Astrophysics Data System (ADS)

    La Frenais, R.; Saraceno, T.; Powell, J.

    2014-04-01

    Is it possible for spaceflight to become more sustainable? Artist and architect Tomas Saraceno proposes a long-term artscience research project based on his initial work with solar balloons to join with the efforts of engineers such as John Powell, working on the Airship to Orbit experiments, which describe a three stage process of using airships to fly to a large suborbital "Dark Sky Station' then literally floating into orbit with additional electrical and chemical propulsion. (See: http://www.jpaerospace.com) In his artworks Tomás Saraceno proposes cell-like flying cities as possible architectonic living spaces in direct reference to Buckminster Fuller's Cloud Nine (circa 1960). The fantastic architectural utopia Cloud Nine consists of a freely floating sphere measuring one mile in diameter that offers living space to several autonomous communities encompassing thousands of inhabitants each. The notion of the cloud is essential to the artist's work. The cloud as metaphor stands for artistic intention, for the meaning of territory and border in today's (urban) society, and for exploring possibilities for the sustainable development of the human living environment. In Saraceno's work this environment is not limited to the earth, but is explicitly conceived to reach into outer space. (Biomimetic Constructions- On the works of Tomás Saraceno By Katharina Schlüter) Saraceno is also interested in human factors experiments using his existing constructions as analogue environments for living on Mars and is proposing carry out a series of workshops, experiments and solar balloon launces in White Sands desert in early 2016 in collaboration with the curator Dr Rob La Frenais, the Rubin Center at The University of Texas at El Paso and various scientific partners.

  10. Liquid encapsulated float zone process and apparatus

    NASA Technical Reports Server (NTRS)

    Naumann, Robert J. (Inventor); Frazier, Donald O. (Inventor); Lehoczky, Sandor L. (Inventor); Vlasse, Marcus (Inventor); Facemire, Barbara R. (Inventor)

    1988-01-01

    The process and apparatus for growing crystals using float zone techniques are described. A rod of crystalline materials is disposed in a cylindrical container, leaving a space between the rod and container walls. This space is filled with an encapsulant, selected to have a slightly lower melting point than the crystalline material. The rod is secured to a container end cap at one end and to a shaft at its other end. A piston slides over the rod and provides pressure to prevent loss of volatile components upon melting of the rod. Prior to melting the rod the container is first heated to melt the encapsulant, with any off-gas from this step being vented to a cavity behind the piston. The piston moves slightly forward owing to volume change upon melting of the encapsulant, and the vent passageway is closed. The container is then moved longitudinally through a heated zone to progressively melt sections of the rod as in conventional float zone processes. The float zone technique may be used in the microgravity environment of space.

  11. Ipsilateral Floating Hip and Floating Knee - A Rare Entity

    PubMed Central

    Yashavantha Kumar, C; Nalini, K B; Nagaraj, Prashanth; Jawali, Abhijith

    2013-01-01

    Introduction: Ipsilateral floating hip and floating knee are very rare injuries. These injuries so uncommon that only three cases of similar kind have been reported. These injuries are due to high velocity injuries following motor vehicle accidents. Management of such complex injuries is a challenging task even in experienced hands as there are no standard treatment guidelines for such fractures. Case Report: We hereby report a 20 yr old male who sustained ipsilateral floating hip and ipsilateral floating knee injuries following motor vehicle accident. Patient was stabilized initially and later taken up for surgery. Patient was treated with interlocking nail for femur and tibia in the same sitting whereas acetabulam fracture was managed conservatively. At five months all the fractures united well with restoration of good range of motion in both hip and knee Conclusion: Ipsilateral floating knee and floating hip are very rare injuries seen following high velocity motor vehicle accidents. There are no standard guidelines for treatment of those fractures as only a few cases of similar kind have been reported in literature. Early fixation and aggressive mobilization ensures fracture union and fewer complications. PMID:27298908

  12. Floating orbital molecular dynamics simulations.

    PubMed

    Perlt, Eva; Brüssel, Marc; Kirchner, Barbara

    2014-04-21

    We introduce an alternative ab initio molecular dynamics simulation as a unification of Hartree-Fock molecular dynamics and the floating orbital approach. The general scheme of the floating orbital molecular dynamics method is presented. Moreover, a simple but sophisticated guess for the orbital centers is provided to reduce the number of electronic structure optimization steps at each molecular dynamics step. The conservation of total energy and angular momentum is investigated in order to validate the floating orbital molecular dynamics approach with and without application of the initial guess. Finally, a water monomer and a water dimer are simulated, and the influence of the orbital floating on certain properties like the dipole moment is investigated. PMID:24600690

  13. Electrically floating, near vertical incidence, skywave antenna

    SciTech Connect

    Anderson, Allen A.; Kaser, Timothy G.; Tremblay, Paul A.; Mays, Belva L.

    2014-07-08

    An Electrically Floating, Near Vertical Incidence, Skywave (NVIS) Antenna comprising an antenna element, a floating ground element, and a grounding element. At least part of said floating ground element is positioned between said antenna element and said grounding element. The antenna is separated from the floating ground element and the grounding element by one or more electrical insulators. The floating ground element is separated from said antenna and said grounding element by one or more electrical insulators.

  14. Skylab floating ice experiment

    NASA Technical Reports Server (NTRS)

    Campbell, W. J. (Principal Investigator); Ramseier, R. O.; Weaver, R. J.; Weeks, W. F.

    1975-01-01

    The author has identified the following significant results. Coupling of the aircraft data with the ground truth observations proved to be highly successful with interesting results being obtained with IR and SLAR passive microwave techniques, and standard photography. Of particular interest were the results of the PMIS system which operated at 10.69 GHz with both vertical and horizontal polarizations. This was the first time that dual polarized images were obtained from floating ice. In both sea and lake ice, it was possible to distinguish a wide variety of thin ice types because of their large differences in brightness temperatures. It was found that the higher brightness temperature was invariably obtained in the vertically polarized mode, and as the age of the ice increases the brightness temperature increases in both polarizations. Associated with this change in age, the difference in temperature was observed as the different polarizations decreased. It appears that the horizontally polarized data is the most sensitive to variations in ice type for both fresh water and sea ice. The study also showed the great amount of information on ice surface roughness and deformation patterns that can be obtained from X-band SLAR observations.

  15. Floating into Thin Air

    SciTech Connect

    Hazi, A U

    2007-02-06

    On May 18, 2005, a giant helium balloon carrying the High Energy Focusing Telescope (HEFT) sailed into the spring sky over the deserts of New Mexico. The spindly steel and aluminum gondola that houses the optics, detectors, and other components of the telescope floated for 25 hours after its launch from Fort Sumner, New Mexico. For 21 of those hours, the balloon was nearly 40 kilometers above Earth's surface--almost four times higher than the altitude routinely flown by commercial jet aircraft. In the upper reaches of Earth's atmosphere, HEFT searched the universe for x-ray sources from highly energetic objects such as binary stars, galaxy clusters, and supermassive black holes. Before landing in Arizona, the telescope observed and imaged a dozen scientific targets by capturing photons emitted from these objects in the high-energy (hard) x-ray range (above 10 kiloelectronvolts). Among these targets were the Crab synchrotron nebula, the black hole Cygnus X-1 (one of the brightest x-ray sources in the sky), and the blazar 3C454.3. The scientific data gathered from these targets are among the first focused hard x-ray images returned from high altitudes.

  16. Floating wind turbine system

    NASA Technical Reports Server (NTRS)

    Viterna, Larry A. (Inventor)

    2009-01-01

    A floating wind turbine system with a tower structure that includes at least one stability arm extending therefrom and that is anchored to the sea floor with a rotatable position retention device that facilitates deep water installations. Variable buoyancy for the wind turbine system is provided by buoyancy chambers that are integral to the tower itself as well as the stability arm. Pumps are included for adjusting the buoyancy as an aid in system transport, installation, repair and removal. The wind turbine rotor is located downwind of the tower structure to allow the wind turbine to follow the wind direction without an active yaw drive system. The support tower and stability arm structure is designed to balance tension in the tether with buoyancy, gravity and wind forces in such a way that the top of the support tower leans downwind, providing a large clearance between the support tower and the rotor blade tips. This large clearance facilitates the use of articulated rotor hubs to reduced damaging structural dynamic loads. Major components of the turbine can be assembled at the shore and transported to an offshore installation site.

  17. The Research of Road Traffic Based on Floating Car Data

    NASA Astrophysics Data System (ADS)

    Zhang, Junyou; Jian, Meng; Tang, Rui

    Based on the analysis of floating car traffic information acquisition and processing system structure and construction frame, combining the Zibo floating car features and road conditions, using historical data provided by Zibo city bus companies, adopting the ArcGIS Engine of ESRI company as a map components, putting forward the nearest point estimate map matching algorithms, combining data fusion technology based on Kalman filter and road running speed calibration algorithm, predicting road traffic running status in certain period and express it in the GIS map, this paper completed the design, the practice has proved the suggested method is feasible.

  18. Orthogonal test and experimental study on fire floating pump

    NASA Astrophysics Data System (ADS)

    Liu, J. R.; Zheng, J. F.; Fu, D. P.; Wang, P.

    2013-12-01

    In order to develop high efficiency fire floating pump, 250YYB-250 fire floating pump was taken as an example. The orthogonal experiment of L9 (34), which contains factors with three levels of blade numbers of impeller, outlet angle, impeller fold-angle, was performed to design nine types of impellers. Numerical simulation of whole flow field based on Fluent was adopted to perform an orthogonal test, the order of geometric parameters affects the performance of fire floating pump with complex impeller. The best design scheme for pump model was acquired. Meanwhile, the optimized design scheme was determined, and corresponding test was carried out. It demonstrated that the efficiency of the final optimal design model pump at rated flow point is of 85%. The efficiency is higher than the national standards, which verified the feasibility of the method of orthogonal design in pump design.

  19. 14 CFR 25.529 - Hull and main float landing conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... is directed inward perpendicularly to the plane of symmetry at a point midway between the keel and... symmetry midway between the keel and chine lines of the float, at the same longitudinal station as...

  20. 14 CFR 25.529 - Hull and main float landing conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... is directed inward perpendicularly to the plane of symmetry at a point midway between the keel and... symmetry midway between the keel and chine lines of the float, at the same longitudinal station as...

  1. 14 CFR 23.529 - Hull and main float landing conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... as the upward component but is directed inward perpendicularly to the plane of symmetry at a point..., perpendicularly to the plane of symmetry midway between the keel and chine lines of the float, at the...

  2. 14 CFR 23.529 - Hull and main float landing conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... as the upward component but is directed inward perpendicularly to the plane of symmetry at a point..., perpendicularly to the plane of symmetry midway between the keel and chine lines of the float, at the...

  3. Tank Tests of Models of Floats for Single-float Seaplanes First Series.

    NASA Technical Reports Server (NTRS)

    Parkinson, J B

    1936-01-01

    Large models of the Mark V and Mark VI floats used for single float seaplanes (National Advisory Committee for Aeronautics (NACA) models 41-A and 41-B, respectively) were tested in the NACA tank to provide general test data for typical single floats and a basis for possible improvements of their form. The resistance of model 41-B was greater than that of model 41-A, either when free to trim or at the best trim angle for each. The resistance of model 35-B (a pointed step hull tested free to trim) was less than either of the models at the hump speed, greater at intermediate planing speeds, and less at the speeds and loads near get-away, although the spray was generally worse owing to the absence of transverse flare. The results of the fixed-trim tests of model 41-A were cross plotted to obtain data at the angle for zero trimming moment and at the best trim angle. The trims assumed by models 41-A and 41-B, when tested free to trim, were found to be excessive at the hump speed. The corresponding trim of model 35-B was found to be approximately 3 degrees lower because of the lower angle of afterbody keel used in this model, and the maximum hump resistance was 15 percent lower.

  4. 40 CFR 65.45 - External floating roof converted into an internal floating roof.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 16 2014-07-01 2014-07-01 false External floating roof converted into an internal floating roof. 65.45 Section 65.45 Protection of Environment ENVIRONMENTAL PROTECTION... External floating roof converted into an internal floating roof. The owner or operator who elects...

  5. 40 CFR 65.45 - External floating roof converted into an internal floating roof.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 16 2012-07-01 2012-07-01 false External floating roof converted into an internal floating roof. 65.45 Section 65.45 Protection of Environment ENVIRONMENTAL PROTECTION... External floating roof converted into an internal floating roof. The owner or operator who elects...

  6. 40 CFR 65.45 - External floating roof converted into an internal floating roof.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false External floating roof converted into an internal floating roof. 65.45 Section 65.45 Protection of Environment ENVIRONMENTAL PROTECTION... External floating roof converted into an internal floating roof. The owner or operator who elects...

  7. 40 CFR 65.45 - External floating roof converted into an internal floating roof.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 16 2013-07-01 2013-07-01 false External floating roof converted into an internal floating roof. 65.45 Section 65.45 Protection of Environment ENVIRONMENTAL PROTECTION... External floating roof converted into an internal floating roof. The owner or operator who elects...

  8. 40 CFR 65.45 - External floating roof converted into an internal floating roof.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 15 2011-07-01 2011-07-01 false External floating roof converted into an internal floating roof. 65.45 Section 65.45 Protection of Environment ENVIRONMENTAL PROTECTION... External floating roof converted into an internal floating roof. The owner or operator who elects...

  9. Flinking: Neither Floating nor Sinking.

    ERIC Educational Resources Information Center

    Wilson, Roger B.

    1993-01-01

    Describes an activity that challenges students to make an object that, when released under water, does not float up or sink down. The main concept this activity investigates is the density of ordinary objects in comparison to the density of water. (PR)

  10. Designing seaplane hulls and floats

    NASA Technical Reports Server (NTRS)

    Benoit,

    1926-01-01

    Experimental data, such as the results of tank tests of models, render it possible to predict, at least in principle, as to how a hull or float of a given shape will comport itself. We will see further along, however, how uncertain these methods are and how they leave room for empiricism, which will reign for a long time yet in seaplane research bureaus.

  11. Spectral analysis of Floating Car Data

    NASA Astrophysics Data System (ADS)

    Gössel, F.; Michler, E.; Wrase, B.

    2003-05-01

    Floating Car Data (FCD) are one important data source in traffic telematic systems. The original variable in these systems is the vehicle velocity. The paper analyses the measured value "vehicle velocity" by methods of information technology. Consequences for processing, transmission and storage of FCD under condition of limited resources are discussed. Starting point of the investigation is the analysis of spectral characteristics of velocity-time-profiles. The spectra are determined by the Discrete Fourier Transform (DFT) from measurement data and simulation data of a microscopic traffic model. One essential property of velocity-time-profiles is their low-pass characteristic. The resulting cut-off-frequency is comparatively small and depends on the traffic scenario. Conclusions concerning the necessary sample rate in FCD systems and the processing of raw data are discussed. Finally the transinformation of velocity-time-profiles is analysed. This results in similar values for an optimal sample rate of FCD systems under condition of limited transmission capacity.

  12. Can flexibility help you float?

    NASA Astrophysics Data System (ADS)

    Burton, L. J.; Bush, J. W. M.

    2012-10-01

    We consider the role of flexibility in the weight-bearing characteristics of bodies floating at an interface. Specifically, we develop a theoretical model for a two-dimensional thin floating plate that yields the maximum stable plate load and optimal stiffness for weight support. Plates small relative to the capillary length are primarily supported by surface tension, and their weight-bearing potential does not benefit from flexibility. Above a critical size comparable to the capillary length, flexibility assists interfacial flotation. For plates on the order of and larger than the capillary length, deflection from an initially flat shape increases the force resulting from hydrostatic pressure, allowing the plate to support a greater load. In this large plate limit, the shape that bears the most weight is a semicircle, which displaces the most fluid above the plate for a fixed plate length. Exact results for maximum weight-bearing plate shapes are compared to analytic approximations made in the limits of large and small plate sizes. The value of flexibility for floating to a number of biological organisms is discussed in light of our study.

  13. Instability of floating extensional flows

    NASA Astrophysics Data System (ADS)

    Sayag, Roiy; Worster, Grae

    2015-11-01

    We study the propagation of a viscous fluid over a thin layer of a denser and inviscid fluid. The viscous fluid is released axisymmetrially at constant flux, and is driven by gravity. Near the origin, where the viscous layer is thick, the flow is dominated by vertical shear. In the outer region where the viscous layer is thinner, it floats over the inviscid layer and the dominant stress is extensional. The floating region of such flows remains axisymmetric when the viscous fluid is Newtonian. In contrast, when the viscous fluid is non Newtonian, the floating region can be distributed in an array of extensional tongues. We use experimental and theoretical analysis to study the symmetry breaking of the extensional region. Experiments using polymeric fluids show that the characteristic wavelength of the tongues increases with flux. Theoretically, we model the symmetry breaking as flow instability of a power-law fluid that becomes Newtonian at low strain rates. Our model predicts unstable modes at the strongly non-Newtonian limit, and stable, axisymmetric mode in the Newtonian limit.

  14. Float zone experiments in space

    NASA Technical Reports Server (NTRS)

    Verhoeven, J. D.; Noack, M. A.; Gill, W. N.; Hau, C. C.

    1984-01-01

    The molten zone/freezing crystal interface system and all the mechanisms were examined. If Marangoni convection produces oscillatory flows in the float zone of semiconductor materials, such as silicon, then it is unlikely that superior quality crystals can be grown in space using this process. The major goals were: (1) to determine the conditions for the onset of Marangoni flows in molten tin, a model system for low Prandtl number molten semiconductor materials; (2) to determine whether the flows can be suppressed by a thin oxide layer; and (3) based on experimental and mathematical analysis, to predict whether oscillatory flows will occur in the float zone silicon geometry in space, and if so, could it be suppressed by thin oxide or nitride films. Techniques were developed to analyze molten tin surfaces in a UHV system in a disk float zone geometry to minimize buoyancy flows. The critical Marangoni number for onset of oscillatory flows was determined to be greater than 4300 on atomically clean molten tin surfaces.

  15. Dragging a floating horizontal cylinder

    NASA Astrophysics Data System (ADS)

    Lee, Duck-Gyu; Kim, Ho-Young

    2010-11-01

    A cylinder immersed in a fluid stream experiences a drag, and it is well known that the drag coefficient is a function of the Reynolds number only. Here we study the force exerted on a long horizontal cylinder that is dragged perpendicular to its axis while floating on an air-water interface with a high Reynolds number. In addition to the flow-induced drag, the floating body is subjected to capillary forces along the contact line where the three phases of liquid/solid/gas meet. We first theoretically predict the meniscus profile around the horizontally moving cylinder assuming the potential flow, and show that the profile is in good agreement with that obtained experimentally. Then we compare our theoretical predictions and experimental measurement results for the drag coefficient of a floating horizontal cylinder that is given by a function of the Weber number and the Bond number. This study can help us to understand the horizontal motion of partially submerged objects at air-liquid interface, such as semi-aquatic insects and marine plants.

  16. 14 CFR 29.753 - Main float design.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main float design. 29.753 Section 29.753 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 29.753 Main float design. (a) Bag floats. Each bag float...

  17. 14 CFR 27.753 - Main float design.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Main float design. 27.753 Section 27.753... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 27.753 Main float design. (a) Bag floats. Each bag float must be designed to withstand— (1) The maximum pressure...

  18. 14 CFR 29.753 - Main float design.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Main float design. 29.753 Section 29.753... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 29.753 Main float design. (a) Bag floats. Each bag float must be designed to withstand— (1) The maximum pressure...

  19. 14 CFR 27.753 - Main float design.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main float design. 27.753 Section 27.753... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 27.753 Main float design. (a) Bag floats. Each bag float must be designed to withstand— (1) The maximum pressure...

  20. Modeling International Space Station (ISS) Floating Potentials

    NASA Technical Reports Server (NTRS)

    Ferguson, Dale C.; Gardner, Barbara

    2002-01-01

    The floating potential of the International Space Station (ISS) as a function of the electron current collection of its high voltage solar array panels is derived analytically. Based on Floating Potential Probe (FPP) measurements of the ISS potential and ambient plasma characteristics, it is shown that the ISS floating potential is a strong function of the electron temperature of the surrounding plasma. While the ISS floating potential has so far not attained the pre-flight predicted highly negative values, it is shown that for future mission builds, ISS must continue to provide two-fault tolerant arc-hazard protection for astronauts on EVA.

  1. Wave drag on floating bodies

    PubMed Central

    Le Merrer, Marie; Clanet, Christophe; Quéré, David; Raphaël, Élie; Chevy, Frédéric

    2011-01-01

    We measure the deceleration of liquid nitrogen drops floating at the surface of a liquid bath. On water, the friction force is found to be about 10 to 100 times larger than on a solid substrate, which is shown to arise from wave resistance. We investigate the influence of the bath viscosity and show that the dissipation decreases as the viscosity is increased, owing to wave damping. The measured resistance is well predicted by a model imposing a vertical force (i.e., the drop weight) on a finite area, as long as the wake can be considered stationary. PMID:21876186

  2. Floating patella associated with lymphoedema

    PubMed Central

    Vun, Shen Hwa; Bayam, Levent; Drampalos, Efstathios; Jesry, Mohammed; Fadel, George

    2015-01-01

    Ipsilateral injury of more than one component of the knee extensor apparatus is rare. It is mostly associated with previous trauma, surgery, immunosuppression therapy and systemic disease. We present the first documented case of a spontaneous bifocal disruption of the knee extensor apparatus (i.e. floating patella) associated with lymphoedema. This case highlights the importance of considering lymphoedema as another risk factor for rupture of the knee extensor apparatus. It also highlights the importance of assessing all components of the knee extensor apparatus in patients presenting with acute knee injuries. PMID:25802253

  3. Floating platform well production apparatus

    SciTech Connect

    Nobileau, P.C.

    1980-10-21

    A plurality of wells are clustered around a central riser which is maintained under tension from a floating platform. A plurality of spiders on the riser carry funnels in vertical alignment with the wells. The funnels are sufficiently large to permit the passage of wellhead connectors and master block valves, and the production risers include centralizers which brace the production riser from the funnels through a limited vertical range. Tensioning of the production riser is with a lower force and through a limited range which precludes disengagement of the centralizers from the funnel. Some centralizers are located to facilitate entry and attachment to the wellhead.

  4. Development of hollow/porous floating beads of metoprolol for pulsatile drug delivery.

    PubMed

    Taranalli, Sangmesh S; Dandagi, Panchaxari M; Mastiholimath, Vinayak S

    2015-06-01

    The purpose of this work was to develop hollow calcium pectinate beads for floating pulsatile release of metoprolol tartrate intended for chronopharmacotherapy. Floating pulsatile concept was applied to increase the gastric residence of the dosage form having lag phase followed by a burst release. To overcome limitations of various approaches for imparting buoyancy, hollow/porous beads were prepared by simple process of acid-base reaction during ionotropic cross-linking using low methoxy pectin, xanthan gum, sodium carboxy methyl cellulose, guar gum, locust bean, gellan gum and calcium chloride as a cross-linking agent. Based on the preliminary studies optimized polymers were selected for formulation design with different polymers ratio concentrations. The obtained floating beads were studied for entrapment efficiency, buoyancy study, swelling index, surface morphology, in vitro release, stability studies and in vivo floating study. The floating beads obtained were porous, float up to 12-24 h. The radiological studies (X-rays) pointed out the capability of the system to release drug in lower parts of GIT after a programmed lag time for hypertension. The floating beads provided expected two-phase release pattern with initial lag time during floating in acidic medium followed by rapid pulse release in phosphate buffer. From the accelerated stability studies, it was observed that the formulations are quite stable. All formulations followed first-order release kinetics by diffusion mechanism. This approach suggested the use of hollow calcium pectinate microparticles as promising floating pulsatile drug delivery system for site- and time-specific release of drugs acting as per chronotherapy of diseases. PMID:24744159

  5. Does size and buoyancy affect the long-distance transport of floating debris?

    NASA Astrophysics Data System (ADS)

    Ryan, Peter G.

    2015-08-01

    Floating persistent debris, primarily made from plastic, disperses long distances from source areas and accumulates in oceanic gyres. However, biofouling can increase the density of debris items to the point where they sink. Buoyancy is related to item volume, whereas fouling is related to surface area, so small items (which have high surface area to volume ratios) should start to sink sooner than large items. Empirical observations off South Africa support this prediction: moving offshore from coastal source areas there is an increase in the size of floating debris, an increase in the proportion of highly buoyant items (e.g. sealed bottles, floats and foamed plastics), and a decrease in the proportion of thin items such as plastic bags and flexible packaging which have high surface area to volume ratios. Size-specific sedimentation rates may be one reason for the apparent paucity of small plastic items floating in the world’s oceans.

  6. Floating liquid bridge charge dynamics

    NASA Astrophysics Data System (ADS)

    Teschke, Omar; Soares, David Mendez; Gomes, Whyllerson Evaristo; Valente Filho, Juracyr Ferraz

    2016-01-01

    The interaction of liquid with electric fields is investigated in a configuration where up to 13 kV are applied between electrodes resulting in a 106 V/m electric field in the capillaries and where there is the formation of a free-standing fluid bridge in the interelectrode gap. The Mott-Gurney equation was fitted to the measured ionization current vs applied voltage curve which indicates that the ionization rate at the high-voltage anode electrode dimethylsulfoxide (DMSO) interface and space charging in the interelectrode gap determine the floating liquid bridge current for a given cathode-to-anode voltage. Space charge effects were measured in the cathode becker and also at the liquid bridge since the ionized charges at the anode migrate to the bridge outer surface and decrease the interfacial tension from 43 mJ/m2 to 29 mJ/m2. Two distinct structural regions then form the bridge, a charged plastic (bulk modulus ˜100 MPa) conducting outer layer with a surface conductivity of ˜10-9 Ω-1, which shapes and supports the floating fluid structure, and an inner liquid cylinder, where DMSO molecules flow.

  7. 32 CFR 935.165 - Floating objects.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Floating objects. 935.165 Section 935.165 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE TERRITORIAL AND INSULAR REGULATIONS WAKE ISLAND CODE Public Safety § 935.165 Floating objects. No person may anchor, moor, or...

  8. Whatever Floats Your Boat: A Design Challenge

    ERIC Educational Resources Information Center

    Kornoelje, Joanne; Roman, Harry T.

    2012-01-01

    This article presents a simple design challenge, based on the PBS program "Design Squad's" "Watercraft" activity that will prove engaging to most technology and engineering students. In this floating boat challenge, students are to build a boat that can float and support 25 pennies for at least 10 seconds--without leaking, sinking, or tipping…

  9. Vertical pump with free floating check valve

    DOEpatents

    Lindsay, Malcolm

    1980-01-01

    A vertical pump with a bottom discharge having a free floating check valve isposed in the outlet plenum thereof. The free floating check valve comprises a spherical member with a hemispherical cage-like member attached thereto which is capable of allowing forward or reverse flow under appropriate conditions while preventing reverse flow under inappropriate conditions.

  10. Future float zone development in industry

    NASA Technical Reports Server (NTRS)

    Sandfort, R. M.

    1980-01-01

    The present industrial requirements for float zone silicon are summarized. Developments desired by the industry in the future are reported. The five most significant problems faced today by the float zone crystal growth method in industry are discussed. They are economic, large diameter, resistivity uniformity, control of carbon, and swirl defects.

  11. 32 CFR 935.165 - Floating objects.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Floating objects. 935.165 Section 935.165 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE TERRITORIAL AND INSULAR REGULATIONS WAKE ISLAND CODE Public Safety § 935.165 Floating objects. No person may anchor, moor, or...

  12. 32 CFR 935.165 - Floating objects.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Floating objects. 935.165 Section 935.165 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE TERRITORIAL AND INSULAR REGULATIONS WAKE ISLAND CODE Public Safety § 935.165 Floating objects. No person may anchor, moor, or...

  13. 32 CFR 935.165 - Floating objects.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Floating objects. 935.165 Section 935.165 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE TERRITORIAL AND INSULAR REGULATIONS WAKE ISLAND CODE Public Safety § 935.165 Floating objects. No person may anchor, moor, or...

  14. 32 CFR 935.165 - Floating objects.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Floating objects. 935.165 Section 935.165 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE TERRITORIAL AND INSULAR REGULATIONS WAKE ISLAND CODE Public Safety § 935.165 Floating objects. No person may anchor, moor, or...

  15. Floating plant dominance as a stable state

    PubMed Central

    Scheffer, Marten; Szabó, Sándor; Gragnani, Alessandra; van Nes, Egbert H.; Rinaldi, Sergio; Kautsky, Nils; Norberg, Jon; Roijackers, Rudi M. M.; Franken, Rob J. M.

    2003-01-01

    Invasion by mats of free-floating plants is among the most important threats to the functioning and biodiversity of freshwater ecosystems ranging from temperate ponds and ditches to tropical lakes. Dark, anoxic conditions under thick floating-plant cover leave little opportunity for animal or plant life, and they can have large negative impacts on fisheries and navigation in tropical lakes. Here, we demonstrate that floating-plant dominance can be a self-stabilizing ecosystem state, which may explain its notorious persistence in many situations. Our results, based on experiments, field data, and models, represent evidence for alternative domains of attraction in ecosystems. An implication of our findings is that nutrient enrichment reduces the resilience of freshwater systems against a shift to floating-plant dominance. On the other hand, our results also suggest that a single drastic harvest of floating plants can induce a permanent shift to an alternative state dominated by rooted, submerged growth forms. PMID:12634429

  16. Real time simulator with Ti floating point digital signal processor

    SciTech Connect

    Razazian, K.; Bobis, J.P.; Dieckman, S.L.; Raptis, A.C.

    1994-08-01

    This paper describes the design and operation of a Real Time Simulator using Texas Instruments TMS320C30 digital signal processor. This system operates with two banks of memory which provide the input data to digital signal processor chip. This feature enables the TMS320C30 to be utilized in variety of applications for which external connections to acquire input data is not needed. In addition, some practical applications of this Real Time Simulator are discussed.

  17. Semi-submersible floating structure

    SciTech Connect

    Finsterwalder, K.

    1981-06-23

    A semi-submersible floating structure includes a horizontal platform with a symmetrical arrangement of buoyant bodies extending vertically downwardly from the platform. The buoyant bodies consist of a tubular column secured by a bending-resistant connection to the platform with a closed container secured to and extending downwardly from the lower end of the tubular column. The horizontal cross-sectional area of the closed container is for most of its vertical height greater than the transverse cross -sectional area of the tubular column. At least the lower portion of the closed container has a curvilinear surface. An annular wall extends around and is spaced radially outwardly from each of the closed containers and the wall, in combination with the enclosed container, forms an annular chamber therebetween open at the bottom and closed at the top. The platform and the buoyant bodies are formed of reinforced concrete or prestressed concrete.

  18. Design and optimization of floating drug delivery system of acyclovir.

    PubMed

    Kharia, A A; Hiremath, S N; Singhai, A K; Omray, L K; Jain, S K

    2010-09-01

    The purpose of the present work was to design and optimize floating drug delivery systems of acyclovir using psyllium husk and hydroxypropylmethylcellulose K4M as the polymers and sodium bicarbonate as a gas generating agent. The tablets were prepared by wet granulation method. A 3(2) full factorial design was used for optimization of drug release profile. The amount of psyllium husk (X1) and hydroxypropylmethylcellulose K4M (X2) were selected as independent variables. The times required for 50% (t(50%)) and 70% (t(70%)) drug dissolution were selected as dependent variables. All the designed nine batches of formulations were evaluated for hardness, friability, weight variation, drug content uniformity, swelling index, in vitro buoyancy, and in vitro drug release profile. All formulations had floating lag time below 3 min and constantly floated on dissolution medium for more than 24 h. Validity of the developed polynomial equation was verified by designing two check point formulations (C1 and C2). The closeness of predicted and observed values for t(50%) and t(70%) indicates validity of derived equations for the dependent variables. These studies indicated that the proper balance between psyllium husk and hydroxypropylmethylcellulose K4M can produce a drug dissolution profile similar to the predicted dissolution profile. The optimized formulations followed Higuchi's kinetics while the drug release mechanism was found to be anomalous type, controlled by diffusion through the swollen matrix. PMID:21694992

  19. Three-dimensional floating images as overt security features

    NASA Astrophysics Data System (ADS)

    Dunn, Douglas S.; Potts, Travis L.; Lorimor, Lynn E.; Jonza, James M.; Smithson, Robert M.; Maki, Stephen P.

    2006-02-01

    3M has developed a proprietary laser process for creating three-dimensional images that appear to float above and/or below the plane of a substrate containing an array of microlenses. During the imaging process the laser records a microscopic image of the desired three-dimensional pattern in the material located at the focal point of each microlens in the array. The images exhibit motion parallax comparable to that seen from holograms and are easily visible in a wide range of ambient lighting conditions. The images are therefore similar, but not identical, to integral images, first proposed in 1908 by Lippmann. The fidelity of these floating images requires maintaining exact registration between the microlens array and the corresponding microimage array. In addition, the use of an ablative laser process for the production of the microimages enables the production of microimage features smaller than the diffraction limit (up to approximately 50,000 dpi). The images are therefore very difficult to simulate, counterfeit, or modify and are highly desirable as an overt security feature. 3M has scaled up the floating image process to produce images in Confirm TM Retroreflective Security Laminate to authenticate passports and driver's licenses and in retroreflective license plate sheeting as the Ensure TM Virtual Security Thread to authenticate vehicle registration. This allows addition of features to a secure document that are easily verifiable, using only the human eye, by a large and widely disperse population to create an identity document that is easily identified as genuine.

  20. Characteristics of a Single Float Seaplane During Take-off

    NASA Technical Reports Server (NTRS)

    Crowley, J W , Jr; Ronan, K M

    1925-01-01

    At the request of the Bureau of Aeronautics, Navy Department, the National Advisory Committee for Aeronautics at Langley Field is investigating the get-away characteristics of an N-9H, a DT-2, and an F-5l, as representing, respectively, a single float, a double float, and a boat type of seaplane. This report covers the investigation conducted on the N-9H. The results show that a single float seaplane trims aft in taking off. Until a planing condition is reached the angle of attack is about 15 degrees and is only slightly affected by controls. When planing it seeks a lower angle, but is controllable through a widening range, until at the take-off it is possible to obtain angles of 8 degrees to 15 degrees with corresponding speeds of 53 to 41 M. P. H. or about 40 per cent of the speed range. The point of greatest resistance occurs at about the highest angle of a pontoon planing angle of 9 1/2 degrees and at a water speed of 24 M. P. H.

  1. Floating electron states in covalent semiconductors.

    PubMed

    Matsushita, Yu-ichiro; Furuya, Shinnosuke; Oshiyama, Atsushi

    2012-06-15

    We report first-principles electronic-structure calculations that clarify the floating nature of electron states in covalent semiconductors. It is found that wave functions of several conduction- and valence-band states, including the conduction-band minima, do not distribute near atomic sites, as was taken for granted, but float in interstitial channels in most semiconductors. The directions and shapes of the interstitial channels depend on the crystal symmetry so that mysterious variation of the energy gaps in SiC polymorphs is naturally explained by considering the floating nature. PMID:23004300

  2. Floating-gated memory based on carbon nanotube field-effect transistors with Si floating dots

    NASA Astrophysics Data System (ADS)

    Seike, Kohei; Fujii, Yusuke; Ohno, Yasuhide; Maehashi, Kenzo; Inoue, Koichi; Matsumoto, Kazuhiko

    2014-01-01

    We have fabricated a carbon nanotube field-effect transistor (CNTFET)-based nonvolatile memory device with Si floating dots. The electrical characteristics of this memory device were compared with those of devices with a HfO2 charge storage layer or Au floating dots. For a sweep width of 6 V, the memory window of the devices with the Si floating dots increased twofold as compared with that of the devices with the HfO2 layer. Moreover, the retention characteristics revealed that, for the device with the Au floating dots, the off-state had almost the same current as the on-state at the 400th s. However, the devices with the Si floating dots had longer-retention characteristics. The results indicate that CNTFET-based devices with Si floating dots are promising candidates for low-power consumption nonvolatile memory devices.

  3. 33 CFR 144.01-1 - Life floats.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Life floats. 144.01-1 Section 144... CONTINENTAL SHELF ACTIVITIES LIFESAVING APPLIANCES Manned Platforms § 144.01-1 Life floats. Each manned platform shall be provided with at least two approved life floats. The life floats shall have...

  4. 33 CFR 144.01-1 - Life floats.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Life floats. 144.01-1 Section 144... CONTINENTAL SHELF ACTIVITIES LIFESAVING APPLIANCES Manned Platforms § 144.01-1 Life floats. Each manned platform shall be provided with at least two approved life floats. The life floats shall have...

  5. 33 CFR 144.01-1 - Life floats.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Life floats. 144.01-1 Section 144... CONTINENTAL SHELF ACTIVITIES LIFESAVING APPLIANCES Manned Platforms § 144.01-1 Life floats. Each manned platform shall be provided with at least two approved life floats. The life floats shall have...

  6. 33 CFR 144.01-1 - Life floats.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Life floats. 144.01-1 Section 144... CONTINENTAL SHELF ACTIVITIES LIFESAVING APPLIANCES Manned Platforms § 144.01-1 Life floats. Each manned platform shall be provided with at least two approved life floats. The life floats shall have...

  7. 14 CFR 27.751 - Main float buoyancy.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main float buoyancy. 27.751 Section 27.751 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 27.751 Main float buoyancy. (a) For main floats, the...

  8. 14 CFR 29.751 - Main float buoyancy.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main float buoyancy. 29.751 Section 29.751 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 29.751 Main float buoyancy. (a) For main floats,...

  9. 14 CFR 25.751 - Main float buoyancy.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main float buoyancy. 25.751 Section 25.751 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Floats and Hulls § 25.751 Main float buoyancy. Each main float must have— (a)...

  10. 14 CFR 29.757 - Hull and auxiliary float strength.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Hull and auxiliary float strength. 29.757... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 29.757 Hull and auxiliary float strength. The hull, and auxiliary floats if used, must withstand...

  11. 14 CFR 29.757 - Hull and auxiliary float strength.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hull and auxiliary float strength. 29.757... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 29.757 Hull and auxiliary float strength. The hull, and auxiliary floats if used, must withstand...

  12. 14 CFR 29.757 - Hull and auxiliary float strength.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Hull and auxiliary float strength. 29.757... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 29.757 Hull and auxiliary float strength. The hull, and auxiliary floats if used, must withstand...

  13. 14 CFR 29.757 - Hull and auxiliary float strength.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Hull and auxiliary float strength. 29.757... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 29.757 Hull and auxiliary float strength. The hull, and auxiliary floats if used, must withstand...

  14. 14 CFR 29.757 - Hull and auxiliary float strength.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Hull and auxiliary float strength. 29.757... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Floats and Hulls § 29.757 Hull and auxiliary float strength. The hull, and auxiliary floats if used, must withstand...

  15. 14 CFR 23.753 - Main float design.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Main float design. 23.753 Section 23.753... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Floats and Hulls § 23.753 Main float design. Each seaplane main float must meet the requirements of § 23.521....

  16. 14 CFR 23.753 - Main float design.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main float design. 23.753 Section 23.753... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Floats and Hulls § 23.753 Main float design. Each seaplane main float must meet the requirements of § 23.521....

  17. Surface tension supported floating of heavy objects: Why elongated bodies float better?

    PubMed

    Bormashenko, Edward

    2016-02-01

    Floating of bodies heavier than the supporting liquid is discussed. Floating of cylindrical, ellipsoidal bodies and rectangular plates possessing lateral dimensions smaller than the capillary length is treated. It is demonstrated that more elongated bodies of a fixed volume are better supported by capillary forces, due to the increase in the perimeter of the triple line. Thus, floating of metallic needles obtains reasonable explanation. PMID:26513731

  18. Exploring Floating Concrete and Beam Design.

    ERIC Educational Resources Information Center

    Snell, Billie G.; Snell, Luke M.

    2002-01-01

    Presents two construction activities that address both state and federal science standards and encourage students to consider career options in mathematics and science. Includes floating concrete and paper bridge activities. (YDS)

  19. Lagrangian floats as sea floor imaging platforms

    NASA Astrophysics Data System (ADS)

    Roman, Chris; Inglis, Gabrielle; McGilvray, Bryan

    2011-10-01

    There is a persistent need for high resolution photographic images of the sea floor and associated biota for marine habitat classification and fisheries stock assessment. This paper presents a novel low cost Lagrangian imaging platform that offers high quality images with reduced operational demands in comparison to existing methodologies such as diver surveys, drop cameras, ship towed systems and dedicated remote or autonomous underwater vehicles. The platform consists of a recently developed bottom following Lagrangian float fit with down looking stereo cameras and strobe lighting. The float can use active ballasting to perform constant altitude photographic drift surveys in coastal waters over varying bathymetry. Images from the float can be used to create large photomosaics, stereographic bathymetry estimates and image-derived current measurements. Test data are presented to demonstrate the operation of the Lagrangian float and summarize the data products.

  20. Archimedes' floating bodies on a spherical Earth

    NASA Astrophysics Data System (ADS)

    Rorres, Chris

    2016-01-01

    Archimedes was the first to systematically find the centers of gravity of various solid bodies and to apply this concept in determining stable configurations of floating bodies. In this paper, we discuss an error in a proof developed by Archimedes that involves determining whether a uniform, spherical cap will float stably with its base horizontal in a liquid on a spherical Earth. We present a simpler, corrected proof and discuss aspects of his proof regarding a spherical cap that is not uniform.

  1. Floating phenomenon and mode of color appearance

    NASA Astrophysics Data System (ADS)

    Aoki, Hironobu; Shinoda, Hiroyuki; Ikeda, Mitsuo

    2002-06-01

    We found an interesting phenomenon concerning the motion perception and the mode of color appearance. We suppose you are holding a stiff sheet of picture and move it laterally to and fro in front of the eye. Though the picture and all items in it move physically altogether with your hand, your perception is not always so. But when the picture that is a figure appears light-source color mode and a background of object color, a figure appears to slip on a background. We call this a 'floating phenomenon.' We predicted the occurrence of floating phenomenon depends on whether the color is perceived to belong to an object or not. To examine the relation between the floating phenomenon and the mode of color appearance, we measured the luminance threshold of floating phenomenon and the transition luminance between two color modes by constant stimulus method to use a mondrian. Our results show the floating never occurred when the target appeared as object color mode. The floating phenomenon may be caused by the separation of the light-source color from an object or week-belonging.

  2. Cadmium uptake by floating macrophytes.

    PubMed

    Maine, M A; Duarte, M V; Suñé, N L

    2001-08-01

    Cd uptake capacity of a group of floating macrophytes (Salvinia herzogii, Pistia stratiotes, Hydromistia stolonifera and Eichhornia crassipes) was determined in outdoors experiments during the lowest temperature period of the year. Although all studied species were highly efficient in the Cd uptake, Pistia stratiotes was selected for further research because of its superior performance and its higher average relative growth rate. Cadmium% removal by Pistia stratiotes was greater in the first 24 h of the experiments (63, 65, 72 and 74% of the added Cd for 1, 2, 4 and 6 mg Cd 1(-1), respectively). After 31 days of growth, Pistia statiotes efficiently removed Cd at the studied concentrations. The macrophyte was able to keep its capacity for Cd removal even though some toxicity symptoms appeared at 4 and 6 mg Cd 1(-1). The greater the initial concentration, the greater Cd bioaccumulation rates. The increase of Cd concentration in plant tissues occurred especially in roots and was linearly related to the quantity of Cd added. Cd sorption by roots is faster than translocation to the plant aerial part and it occurs mainly during the first 24h. PMID:11456161

  3. Floating intake reduces pump damage

    SciTech Connect

    Kronig, A.

    1993-12-31

    The solution to a costly sand erosion problem at the Grande Dixence hydroelectric project in Switzerland turned out to be as simple as a floating pump. The 726-MW Grande Dixence project drains a 350-square-kilometer reach of the Zermatt and Herens valleys in the southwestern Swiss Alps. About half of the drainage area is covered by active glaciers. Because the glaciers in Zermatt Valley are so low in altitude, their water is collected in Z`mutt Reservoir at the base of the Matterhorn, then pumped up 500 meters for transport to the main Grande Disence Reservoir near Sion. The glacier water is heavily laden with sand. In spite of a gravel pass and a desilter, the 700,000-acubic-meter Z`mutt Reservoir receives large quantities of sand. The sand tends to remain in solution because of the low water temperatures (1 to 2 degrees Centigrade). In the original intake system, the sand would be sucked into the pump intakes, causing extensive erosion to the pump wheels and an expensive yearly program of repair. (Pump damage averaged 200,000 Swiss Francs ($284,000 U.S.) per year between 1980 and 1985.)

  4. PREDICTIVE PHARMACOKINETICS OF TRAMADOL HYDROCHLORIDE FLOATING TABLETS.

    PubMed

    Wang, Jianming; Zhang, Yanzhen; Guo, Zhiling; Tao, Qingwen; Wang, Yongjun; Zhou, Wei; Ma, Xiao; Li, Zhihong

    2016-01-01

    The purpose of this study was to propose the effectiveness of convolution approach to predict pharmacokinetics of tramadol hydrochloride floating tablets, prepared by using various ratios of carbopol, HPMC K100M, and Hibiscus rosa Sinensis as excipient. The in vitro dissolution test was conducted using paddle method in 900 mL of HCl buffer with pH 1.2 to simulate the gastric condition. The stirring speed of paddles was set at 70 rpm. Temperature of dissolution medium was adjusted at 37 ± 5 °C. At predetermined time points, 5 mL of dissolution samples were taken with a replacement of same volume using fresh medium. The obtained samples were analyzed at 271 nm using UV visible spectrophotometer. The values of predicted pharmacokinetic parameters like Cmax (maximum blood drug level), Tmax (time required to attain maximum blood drug level), and AUC (area under blood drug concentration curve) ranged between 80.8 ± 3.2-119.6 ± 4.7 ng/mL, 11.4 ± 0.2-12.2 ± 0.2 h, and 1430.5 ± 209.5-1970.6 ± 287.4 ng.h/mL, respectively. This certainly is a desired feature required at the formulation development step, where the formulator requires the development of a formulation using desired in vivo features on the basis of only accessible in vitro data. It can be concluded from the results that convolution method is a practical method for the prediction of drug concentration in blood and for quality control. PMID:27476294

  5. Floating seal system for rotary devices

    DOEpatents

    Banasiuk, H.A.

    1983-08-23

    This invention relates to a floating seal system for rotary devices to reduce gas leakage around the rotary device in a duct and across the face of the rotary device to an adjacent duct. The peripheral seal bodies are made of resilient material having a generally U-shaped cross section wherein one of the legs is secured to a support member and the other of the legs forms a contacting seal against the rotary device. The legs of the peripheral seal form an extended angle of intersection of about 10[degree] to about 30[degree] in the unloaded condition to provide even sealing forces around the periphery of the rotary device. The peripheral seal extends around the periphery of the support member except where intersected by radial seals which reduce gas leakage across the face of the rotary device and between adjacent duct portions. The radial seal assembly is fabricated from channel bars, the smaller channel bar being secured to the divider of the support member and a larger inverted rigid floating channel bar having its legs freely movable over the legs of the smaller channel bar forming therewith a tubular channel. A resilient flexible tube is positioned within the tubular channel for substantially its full length to reduce gas leakage across the tubular channel. A spacer extends beyond the face of the floating channel near each end of the floating channel a distance to provide desired clearance between the floating channel and the face of the rotary device. 5 figs.

  6. Floating seal system for rotary devices

    DOEpatents

    Banasiuk, Hubert A.

    1983-01-01

    This invention relates to a floating seal system for rotary devices to reduce gas leakage around the rotary device in a duct and across the face of the rotary device to an adjacent duct. The peripheral seal bodies are made of resilient material having a generally U-shaped cross section wherein one of the legs is secured to a support member and the other of the legs forms a contacting seal against the rotary device. The legs of the peripheral seal form an extended angle of intersection of about 10.degree. to about 30.degree. in the unloaded condition to provide even sealing forces around the periphery of the rotary device. The peripheral seal extends around the periphery of the support member except where intersected by radial seals which reduce gas leakage across the face of the rotary device and between adjacent duct portions. The radial seal assembly is fabricated from channel bars, the smaller channel bar being secured to the divider of the support member and a larger inverted rigid floating channel bar having its legs freely movable over the legs of the smaller channel bar forming therewith a tubular channel. A resilient flexible tube is positioned within the tubular channel for substantially its full length to reduce gas leakage across the tubular channel. A spacer extends beyond the face of the floating channel near each end of the floating channel a distance to provide desired clearance between the floating channel and the face of the rotary device.

  7. Battery charging in float vs. cycling environments

    SciTech Connect

    COREY,GARTH P.

    2000-04-20

    In lead-acid battery systems, cycling systems are often managed using float management strategies. There are many differences in battery management strategies for a float environment and battery management strategies for a cycling environment. To complicate matters further, in many cycling environments, such as off-grid domestic power systems, there is usually not an available charging source capable of efficiently equalizing a lead-acid battery let alone bring it to a full state of charge. Typically, rules for battery management which have worked quite well in a floating environment have been routinely applied to cycling batteries without full appreciation of what the cycling battery really needs to reach a full state of charge and to maintain a high state of health. For example, charge target voltages for batteries that are regularly deep cycled in off-grid power sources are the same as voltages applied to stand-by systems following a discharge event. In other charging operations equalization charge requirements are frequently ignored or incorrectly applied in cycled systems which frequently leads to premature capacity loss. The cause of this serious problem: the application of float battery management strategies to cycling battery systems. This paper describes the outcomes to be expected when managing cycling batteries with float strategies and discusses the techniques and benefits for the use of cycling battery management strategies.

  8. A novel floating controlled release drug delivery system prepared by hot-melt extrusion.

    PubMed

    Vo, Anh Q; Feng, Xin; Morott, Joseph T; Pimparade, Manjeet B; Tiwari, Roshan V; Zhang, Feng; Repka, Michael A

    2016-01-01

    Floating dosage forms are an important formulation strategy for drugs with a narrow absorption window and low intestinal solubility, and for localized gastric treatment. Novel floating pellets were prepared using the hot-melt extrusion (HME) technology. Uniformly foamed strands were created by liquid injection pumping and screw configuration modification. The ammonio methacrylate copolymer (Eudragit® RSPO) foaming structure was formed by a liquid-vapor phase transition inside the strand upon die exiting resulting from the sudden decrease in external pressure, vaporizing the liquid ethanol and vacating the extruded material. This generated uniform vacuous regions in the extrudate. The pellets' internal structure was investigated using scanning electron microscopy (SEM). The formulation constituents' and processing parameters' effects on the drug release profiles, floating force, and the pellets' micromeritic properties were evaluated by design of experiments: all formulations showed zero lag time and excellent floating strength, indicating immediate-floating pellet formation. The pellets' drug release profiles were controlled by multiple independent variables at different time points (⩽ 24 h). Drug loading significantly affected drug release within the first hour, the hydroxypropyl methylcellulose (HPMC) content thereafter. Understanding the variables' effects on the formulations allows for the tailoring of this delivery system to obtain various drug release profiles. PMID:26643801

  9. Floating mechanism of a small liquid marble

    PubMed Central

    Ooi, Chin Hong; Plackowski, Chris; Nguyen, Anh V.; Vadivelu, Raja K.; John, James A. St.; Dao, Dzung Viet; Nguyen, Nam-Trung

    2016-01-01

    Flotation of small solid objects and liquid droplets on water is critical to natural and industrial activities. This paper reports the floating mechanism of liquid marbles, or liquid droplets coated with hydrophobic microparticles. We used X-ray computed tomography (XCT) to acquire cross-sectional images of the floating liquid marble and interface between the different phases. We then analysed the shape of the liquid marble and the angles at the three-phase contact line (TPCL). We found that the small floating liquid marbles follow the mechanism governing the flotation of solid objects in terms of surface tension forces. However, the contact angles formed and deformation of the liquid marble resemble that of a sessile liquid droplet on a thin, elastic solid. For small liquid marbles, the contact angle varies with volume due to the deformability of the interface. PMID:26902930

  10. Floating zone melting of cadmium telluride

    NASA Technical Reports Server (NTRS)

    Chang, Wen-Ming; Regel, L. L.; Wilcox, W. R.

    1992-01-01

    To produce superior crystals of cadmium telluride, floating zone melting in space has been proposed. Techniques required for floating zone melting of cadmium telluride are being developed. We have successfully float-zoned cadmium telluride on earth using square rods. A resistance heater was constructed for forming the molten zone. Evaporation of the molten zone was controlled by adding excess cadmium to the growth ampoule combined with heating of the entire ampoule. An effective method to hold the feed rod was developed. Slow rotation of the growth ampoule was proven experimentally to be necessary to achieve a complete symmetric molten zone. Most of the resultant cylindrical rods were single crystals with twins. Still needed is a suitable automatic method to control the zone length. We tried a fiber optical technique to control the zone length, but experiments showed that application of this technique to automate zone length control is unlikely to be successful.

  11. Floating mechanism of a small liquid marble

    NASA Astrophysics Data System (ADS)

    Ooi, Chin Hong; Plackowski, Chris; Nguyen, Anh V.; Vadivelu, Raja K.; John, James A. St.; Dao, Dzung Viet; Nguyen, Nam-Trung

    2016-02-01

    Flotation of small solid objects and liquid droplets on water is critical to natural and industrial activities. This paper reports the floating mechanism of liquid marbles, or liquid droplets coated with hydrophobic microparticles. We used X-ray computed tomography (XCT) to acquire cross-sectional images of the floating liquid marble and interface between the different phases. We then analysed the shape of the liquid marble and the angles at the three-phase contact line (TPCL). We found that the small floating liquid marbles follow the mechanism governing the flotation of solid objects in terms of surface tension forces. However, the contact angles formed and deformation of the liquid marble resemble that of a sessile liquid droplet on a thin, elastic solid. For small liquid marbles, the contact angle varies with volume due to the deformability of the interface.

  12. Vibration characteristics of floating slab track

    NASA Astrophysics Data System (ADS)

    Kuo, Chen-Ming; Huang, Cheng-Hao; Chen, Yi-Yi

    2008-11-01

    Coupled equilibrium equations of suspended wheels and floating slab track system were solved with the fourth-order Runge-Kutta method to obtain the deflections, vibration velocities, and wheel-rail contact forces. The program was validated through several aspects. Cases with various vehicle speed, slab mass, and stiffness of slab bearing were analyzed to reveal the effects of slab bearing on track responses. The correlation between wheel-rail resonance and train speed was also discussed. It was found that rail deflections increase significantly as train speed increases. Although large slab mass may lower tuning frequency, it could also result in higher wheel-rail contact force and rail deflections. The floating slab track is effective in isolating loading above 10 Hz, which might present in some railway sections with irregularities. Adopting floating slab track for vibration control for environment along the railway may cause concerns about ride quality and track damages.

  13. Floating mechanism of a small liquid marble.

    PubMed

    Ooi, Chin Hong; Plackowski, Chris; Nguyen, Anh V; Vadivelu, Raja K; John, James A St; Dao, Dzung Viet; Nguyen, Nam-Trung

    2016-01-01

    Flotation of small solid objects and liquid droplets on water is critical to natural and industrial activities. This paper reports the floating mechanism of liquid marbles, or liquid droplets coated with hydrophobic microparticles. We used X-ray computed tomography (XCT) to acquire cross-sectional images of the floating liquid marble and interface between the different phases. We then analysed the shape of the liquid marble and the angles at the three-phase contact line (TPCL). We found that the small floating liquid marbles follow the mechanism governing the flotation of solid objects in terms of surface tension forces. However, the contact angles formed and deformation of the liquid marble resemble that of a sessile liquid droplet on a thin, elastic solid. For small liquid marbles, the contact angle varies with volume due to the deformability of the interface. PMID:26902930

  14. Development of hybrid fluid jet/float polishing process

    NASA Astrophysics Data System (ADS)

    Beaucamp, Anthony T. H.; Namba, Yoshiharu; Freeman, Richard R.

    2013-09-01

    On one hand, the "float polishing" process consists of a tin lap having many concentric grooves, cut from a flat by single point diamond turning. This lap is rotated above a hydrostatic bearing spindle of high rigidity, damping and rotational accuracy. The optical surface thus floats above a thin layer of abrasive particles. But whilst surface texture can be smoothed to ~0.1nm rms (as measured by atomic force microscopy), this process can only be used on flat surfaces. On the other hand, the CNC "fluid jet polishing" process consists of pumping a mixture of water and abrasive particles to a converging nozzle, thus generating a polishing spot that can be moved along a tool path with tight track spacing. But whilst tool path feed can be moderated to ultra-precisely correct form error on freeform optical surfaces, surface finish improvement is generally limited to ~1.5nm rms (with fine abrasives). This paper reports on the development of a novel finishing method, that combines the advantages of "fluid jet polishing" (i.e. freeform corrective capability) with "float polishing" (i.e. super-smooth surface finish of 0.1nm rms or less). To come up with this new "hybrid" method, computational fluid dynamic modeling of both processes in COMSOL is being used to characterize abrasion conditions and adapt the process parameters of experimental fluid jet polishing equipment, including: (1) geometrical shape of nozzle, (2) position relative to the surface, (3) control of inlet pressure. This new process is aimed at finishing of next generation X-Ray / Gamma Ray focusing optics.

  15. On the Assimilation of Argo Float Trajectories into the Mediterranean Forecasting System

    NASA Astrophysics Data System (ADS)

    Nilsson, Jenny A. U.; Dobricic, Srdjan; Taillandier, Vincent; Poulain, Pierre-Marie; Pinardi, Nadia

    2010-05-01

    availability of Argo-float data was noted during the period, with the maximum amount and spread of floats in 2005. The impact of the fall-off in float abundance was studied in terms of analyses, and implications on the operational activities will be pointed out.

  16. Hiding and feeding in floating seaweed: Floating seaweed clumps as possible refuges or feeding grounds for fishes

    NASA Astrophysics Data System (ADS)

    Vandendriessche, Sofie; Messiaen, Marlies; O'Flynn, Sarah; Vincx, Magda; Degraer, Steven

    2007-02-01

    Floating seaweed is considered to be an important habitat for juvenile fishes due to the provision of food, shelter, a visual orientation point and passive transport. The importance of the presence of the highly dynamical seaweed clumps from the North Sea to juvenile neustonic fishes was investigated by analysing both neuston samples (without seaweed) and seaweed samples concerning fish community structure, and length-frequency distributions and feeding habits of five associated fish species. While the neustonic fish community was mainly seasonally structured, the seaweed-associated fish community was more complex: the response of the associated fish species to environmental variables was species specific and probably influenced by species interactions, resulting in a large multivariate distance between the samples dominated by Chelon labrosus and the samples dominated by Cyclopterus lumpus, Trachurus trachurus and Ciliata mustela. The results of the stomach analysis confirmed that C. lumpus is a weedpatch specialist that has a close spatial affinity with the seaweed and feeds intensively on the seaweed-associated invertebrate fauna. Similarly, C. mustela juveniles also fed on the seaweed fauna, but in a more opportunistic way. The shape of the size-frequency distribution suggested enhanced growth when associated with floating seaweed. Chelon labrosus and T. trachurus juveniles were generally large in seaweed samples, but large individuals were also encountered in the neuston. The proportion of associated invertebrate fauna in their diet was of minor importance, compared to the proportions in C. lumpus. Individuals of Syngnathus rostellatus mainly fed on planktonic invertebrates but had a discontinuous size-frequency distribution, suggesting that some of the syngnathids were carried with the seaweed upon detachment and stayed associated. Floating seaweeds can therefore be regarded as ephemeral habitats shared between several fish species (mainly juveniles) that use

  17. 46 CFR 131.870 - Life floats and buoyant apparatus.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Life floats and buoyant apparatus. 131.870 Section 131... OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.870 Life floats and buoyant apparatus. (a) The name of the vessel must be plainly marked or painted on each life float or buoyant...

  18. 46 CFR 131.870 - Life floats and buoyant apparatus.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Life floats and buoyant apparatus. 131.870 Section 131... OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.870 Life floats and buoyant apparatus. (a) The name of the vessel must be plainly marked or painted on each life float or buoyant...

  19. 46 CFR 131.870 - Life floats and buoyant apparatus.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Life floats and buoyant apparatus. 131.870 Section 131... OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.870 Life floats and buoyant apparatus. (a) The name of the vessel must be plainly marked or painted on each life float or buoyant...

  20. 14 CFR 25.535 - Auxiliary float loads.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... follows: EC28SE91.043 where— ρ=mass density of water (slugs/ft.2); V=volume of float (ft.2); C x... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Water Loads § 25.535 Auxiliary float loads. (a..., the prescribed water loads may be distributed over the float bottom to avoid excessive local...

  1. 14 CFR 25.535 - Auxiliary float loads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... follows: EC28SE91.043 where— ρ=mass density of water (slugs/ft.2); V=volume of float (ft.2); C x... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Water Loads § 25.535 Auxiliary float loads. (a..., the prescribed water loads may be distributed over the float bottom to avoid excessive local...

  2. 14 CFR 25.535 - Auxiliary float loads.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... follows: EC28SE91.043 where— ρ=mass density of water (slugs/ft.2); V=volume of float (ft.2); C x... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Water Loads § 25.535 Auxiliary float loads. (a..., the prescribed water loads may be distributed over the float bottom to avoid excessive local...

  3. 14 CFR 25.535 - Auxiliary float loads.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... follows: EC28SE91.043 where— ρ=mass density of water (slugs/ft.2); V=volume of float (ft.2); C x... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Water Loads § 25.535 Auxiliary float loads. (a..., the prescribed water loads may be distributed over the float bottom to avoid excessive local...

  4. 14 CFR 25.535 - Auxiliary float loads.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... follows: EC28SE91.043 where— ρ=mass density of water (slugs/ft.2); V=volume of float (ft.2); C x... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Water Loads § 25.535 Auxiliary float loads. (a..., the prescribed water loads may be distributed over the float bottom to avoid excessive local...

  5. 46 CFR 131.870 - Life floats and buoyant apparatus.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.870 Life floats and buoyant apparatus. (a) The name of the vessel must be plainly marked or painted on each life float or buoyant apparatus... 46 Shipping 4 2010-10-01 2010-10-01 false Life floats and buoyant apparatus. 131.870 Section...

  6. 46 CFR 131.870 - Life floats and buoyant apparatus.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.870 Life floats and buoyant apparatus. (a) The name of the vessel must be plainly marked or painted on each life float or buoyant apparatus... 46 Shipping 4 2011-10-01 2011-10-01 false Life floats and buoyant apparatus. 131.870 Section...

  7. 33 CFR 144.01-15 - Alternates for life floats.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Alternates for life floats. 144... for life floats. (a) Approved lifeboats, approved life rafts or approved inflatable life rafts may be used in lieu of approved life floats for either all or part of the capacity required. When...

  8. 33 CFR 144.01-15 - Alternates for life floats.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Alternates for life floats. 144... for life floats. (a) Approved lifeboats, approved life rafts or approved inflatable life rafts may be used in lieu of approved life floats for either all or part of the capacity required. When...

  9. 33 CFR 144.01-15 - Alternates for life floats.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Alternates for life floats. 144... for life floats. (a) Approved lifeboats, approved life rafts or approved inflatable life rafts may be used in lieu of approved life floats for either all or part of the capacity required. When...

  10. 33 CFR 144.01-15 - Alternates for life floats.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Alternates for life floats. 144... for life floats. (a) Approved lifeboats, approved life rafts or approved inflatable life rafts may be used in lieu of approved life floats for either all or part of the capacity required. When...

  11. 14 CFR 25.753 - Main float design.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Main float design. 25.753 Section 25.753 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Floats and Hulls § 25.753 Main float...

  12. 14 CFR 25.753 - Main float design.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main float design. 25.753 Section 25.753 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Floats and Hulls § 25.753 Main float...

  13. Dealing with Human Death: The Floating Perspective.

    ERIC Educational Resources Information Center

    Kenyon, Gary M.

    1991-01-01

    Explores approach to dealing with human death. Describes floating perspective, based on insights from Choron and Jaspers, as suggesting it is possible to deal with human death by refraining from taking ultimate position on the problem. Position encourages openness to death. Examines role of anxiety and describes possible meaningful outcomes of…

  14. Floating--A Key to Survival.

    ERIC Educational Resources Information Center

    Anderson, Norman

    1980-01-01

    Described are several activities to be used to help students grasp the concept of floating. The activities include the use of a spring scale to measure the weight of the objects in air, in water, and in salt water, and a discussion of why there are differences in these weights. (DS)

  15. Subtropical Productivity from Profiling Floats and Gliders

    NASA Astrophysics Data System (ADS)

    Nicholson, D. P.; Johnson, K. S.; Karl, D. M.

    2015-12-01

    Since 2007 profiling floats equipped with dissolved oxygen and nitrate sensors have been released from the Hawaii Ocean Time-series (HOT) and Bermuda Atlantic Time-series Study (BATS) sites and can be calibrated using time-series observations. More recent deployments have also included bio-optical and pH sensors. Gliders with oxygen sensors and bio-optics have been intermittently deployed near HOT Station ALOHA since 2008 and at BATS since 2014. While gliders maintain a restricted survey region near the time-series stations, profiling floats drifted widely across the subtropical gyres. Multiple floats and gliders enables a cotemporaneous comparison of biogeochemical processes across gyres. These platforms enable observations on spatial scales from submesoscale to basin scale and on temporal scales from diel to interannual. Here, I focus on the spatiotemporal variability of nitrate and oxygen mass balances in the North Pacific and North Atlantic subtropical gyres using a data-assimilating and float-tracking 1D upper ocean model.

  16. Genetics Home Reference: Floating-Harbor syndrome

    MedlinePlus

    ... Arpin S, Afenjar A, Dubern B, Toutain A, Cabrol S, Héron D. Floating-Harbor Syndrome: report on a case ... G, Whiteford ML, Quaio CR, Gomy I, Bertola DR, Albrecht B, Platzer K, McGillivray G, Zou R, ...

  17. Design of crossed-mirror array to form floating 3D LED signs

    NASA Astrophysics Data System (ADS)

    Yamamoto, Hirotsugu; Bando, Hiroki; Kujime, Ryousuke; Suyama, Shiro

    2012-03-01

    3D representation of digital signage improves its significance and rapid notification of important points. Our goal is to realize floating 3D LED signs. The problem is there is no sufficient device to form floating 3D images from LEDs. LED lamp size is around 1 cm including wiring and substrates. Such large pitch increases display size and sometimes spoils image quality. The purpose of this paper is to develop optical device to meet the three requirements and to demonstrate floating 3D arrays of LEDs. We analytically investigate image formation by a crossed mirror structure with aerial aperture, called CMA (crossed-mirror array). CMA contains dihedral corner reflectors at each aperture. After double reflection, light rays emitted from an LED will converge into the corresponding image point. We have fabricated CMA for 3D array of LEDs. One CMA unit contains 20 x 20 apertures that are located diagonally. Floating image of LEDs was formed in wide range of incident angle. The image size of focused beam agreed to the apparent aperture size. When LEDs were located three-dimensionally (LEDs in three depths), the focused distances were the same as the distance between the real LED and the CMA.

  18. Real object-based 360-degree integral-floating display using multiple depth camera

    NASA Astrophysics Data System (ADS)

    Erdenebat, Munkh-Uchral; Dashdavaa, Erkhembaatar; Kwon, Ki-Chul; Wu, Hui-Ying; Yoo, Kwan-Hee; Kim, Young-Seok; Kim, Nam

    2015-03-01

    A novel 360-degree integral-floating display based on the real object is proposed. The general procedure of the display system is similar with conventional 360-degree integral-floating displays. Unlike previously presented 360-degree displays, the proposed system displays the 3D image generated from the real object in 360-degree viewing zone. In order to display real object in 360-degree viewing zone, multiple depth camera have been utilized to acquire the depth information around the object. Then, the 3D point cloud representations of the real object are reconstructed according to the acquired depth information. By using a special point cloud registration method, the multiple virtual 3D point cloud representations captured by each depth camera are combined as single synthetic 3D point cloud model, and the elemental image arrays are generated for the newly synthesized 3D point cloud model from the given anamorphic optic system's angular step. The theory has been verified experimentally, and it shows that the proposed 360-degree integral-floating display can be an excellent way to display real object in the 360-degree viewing zone.

  19. Unsteady aerodynamic analysis for offshore floating wind turbines under different wind conditions.

    PubMed

    Xu, B F; Wang, T G; Yuan, Y; Cao, J F

    2015-02-28

    A free-vortex wake (FVW) model is developed in this paper to analyse the unsteady aerodynamic performance of offshore floating wind turbines. A time-marching algorithm of third-order accuracy is applied in the FVW model. Owing to the complex floating platform motions, the blade inflow conditions and the positions of initial points of vortex filaments, which are different from the fixed wind turbine, are modified in the implemented model. A three-dimensional rotational effect model and a dynamic stall model are coupled into the FVW model to improve the aerodynamic performance prediction in the unsteady conditions. The effects of floating platform motions in the simulation model are validated by comparison between calculation and experiment for a small-scale rigid test wind turbine coupled with a floating tension leg platform (TLP). The dynamic inflow effect carried by the FVW method itself is confirmed and the results agree well with the experimental data of a pitching transient on another test turbine. Also, the flapping moment at the blade root in yaw on the same test turbine is calculated and compares well with the experimental data. Then, the aerodynamic performance is simulated in a yawed condition of steady wind and in an unyawed condition of turbulent wind, respectively, for a large-scale wind turbine coupled with the floating TLP motions, demonstrating obvious differences in rotor performance and blade loading from the fixed wind turbine. The non-dimensional magnitudes of loading changes due to the floating platform motions decrease from the blade root to the blade tip. PMID:25583859

  20. Unsteady aerodynamic analysis for offshore floating wind turbines under different wind conditions

    PubMed Central

    Xu, B. F.; Wang, T. G.; Yuan, Y.; Cao, J. F.

    2015-01-01

    A free-vortex wake (FVW) model is developed in this paper to analyse the unsteady aerodynamic performance of offshore floating wind turbines. A time-marching algorithm of third-order accuracy is applied in the FVW model. Owing to the complex floating platform motions, the blade inflow conditions and the positions of initial points of vortex filaments, which are different from the fixed wind turbine, are modified in the implemented model. A three-dimensional rotational effect model and a dynamic stall model are coupled into the FVW model to improve the aerodynamic performance prediction in the unsteady conditions. The effects of floating platform motions in the simulation model are validated by comparison between calculation and experiment for a small-scale rigid test wind turbine coupled with a floating tension leg platform (TLP). The dynamic inflow effect carried by the FVW method itself is confirmed and the results agree well with the experimental data of a pitching transient on another test turbine. Also, the flapping moment at the blade root in yaw on the same test turbine is calculated and compares well with the experimental data. Then, the aerodynamic performance is simulated in a yawed condition of steady wind and in an unyawed condition of turbulent wind, respectively, for a large-scale wind turbine coupled with the floating TLP motions, demonstrating obvious differences in rotor performance and blade loading from the fixed wind turbine. The non-dimensional magnitudes of loading changes due to the floating platform motions decrease from the blade root to the blade tip. PMID:25583859

  1. Using Tensor Completion Method to Achieving Better Coverage of Traffic State Estimation from Sparse Floating Car Data

    PubMed Central

    Ran, Bin; Song, Li; Cheng, Yang; Tan, Huachun

    2016-01-01

    Traffic state estimation from the floating car system is a challenging problem. The low penetration rate and random distribution make available floating car samples usually cover part space and time points of the road networks. To obtain a wide range of traffic state from the floating car system, many methods have been proposed to estimate the traffic state for the uncovered links. However, these methods cannot provide traffic state of the entire road networks. In this paper, the traffic state estimation is transformed to solve a missing data imputation problem, and the tensor completion framework is proposed to estimate missing traffic state. A tensor is constructed to model traffic state in which observed entries are directly derived from floating car system and unobserved traffic states are modeled as missing entries of constructed tensor. The constructed traffic state tensor can represent spatial and temporal correlations of traffic data and encode the multi-way properties of traffic state. The advantage of the proposed approach is that it can fully mine and utilize the multi-dimensional inherent correlations of traffic state. We tested the proposed approach on a well calibrated simulation network. Experimental results demonstrated that the proposed approach yield reliable traffic state estimation from very sparse floating car data, particularly when dealing with the floating car penetration rate is below 1%. PMID:27448326

  2. Using Tensor Completion Method to Achieving Better Coverage of Traffic State Estimation from Sparse Floating Car Data.

    PubMed

    Ran, Bin; Song, Li; Zhang, Jian; Cheng, Yang; Tan, Huachun

    2016-01-01

    Traffic state estimation from the floating car system is a challenging problem. The low penetration rate and random distribution make available floating car samples usually cover part space and time points of the road networks. To obtain a wide range of traffic state from the floating car system, many methods have been proposed to estimate the traffic state for the uncovered links. However, these methods cannot provide traffic state of the entire road networks. In this paper, the traffic state estimation is transformed to solve a missing data imputation problem, and the tensor completion framework is proposed to estimate missing traffic state. A tensor is constructed to model traffic state in which observed entries are directly derived from floating car system and unobserved traffic states are modeled as missing entries of constructed tensor. The constructed traffic state tensor can represent spatial and temporal correlations of traffic data and encode the multi-way properties of traffic state. The advantage of the proposed approach is that it can fully mine and utilize the multi-dimensional inherent correlations of traffic state. We tested the proposed approach on a well calibrated simulation network. Experimental results demonstrated that the proposed approach yield reliable traffic state estimation from very sparse floating car data, particularly when dealing with the floating car penetration rate is below 1%. PMID:27448326

  3. OCD metrology by floating n/k

    NASA Astrophysics Data System (ADS)

    Yu, Shinn-Sheng; Huang, Jacky; Ke, Chih-Ming; Gau, Tsai-Sheng; Lin, Burn J.; Yen, Anthony; Lane, Lawrence; Vuong, Vi; Chen, Yan

    2007-03-01

    In this paper, one of the major contributions to the OCD metrology error, resulting from within-wafer variation of the refractive index/extinction coefficient (n/k) of the substrate, is identified and quantified. To meet the required metrology accuracy for the 65-nm node and beyond, it is suggested that n/k should be floating when performing the regression for OCD modeling. A feasible way of performing such regression is proposed and verified. As shown in the presented example, the measured CDU (3σ) with n/k fixed and n/k floating is 1.94 nm and 1.42 nm, respectively. That is, the metrology error of CDU committed by assuming n/k fixed is more than 35% of the total CDU.

  4. Electrodynamic convection in silicon floating zones

    NASA Astrophysics Data System (ADS)

    Mühlbauer, A.; Erdmann, W.; Keller, W.

    1983-12-01

    Using a simplified Navier-Stokes equation it has been possible to compute the electrodynamic convection generated by a radio frequency coil field for the modern needle-eye float-zone growth of silicon. The calculated electrodynamic force in such a zone shows maximum values up to 11.7 N/cm 3 and generates flow velocities between 25 and 100 cm/s. As only superficial convection can be brought about by electrodynamic forces, the axial and radial dopant incorporation will not be influenced strongly. A comparison of electrodynamic forces with the other forces possibly causing flow in silicon floating zones shows that the electrodynamic forces exceed all other forces by several orders of magnitude.

  5. TVFMCATS. Time Variant Floating Mean Counting Algorithm

    SciTech Connect

    Huffman, R.K.

    1999-05-01

    This software was written to test a time variant floating mean counting algorithm. The algorithm was developed by Westinghouse Savannah River Company and a provisional patent has been filed on the algorithm. The test software was developed to work with the Val Tech model IVB prototype version II count rate meter hardware. The test software was used to verify the algorithm developed by WSRC could be correctly implemented with the vendor`s hardware.

  6. Floating vs flying: A propulsion energy comparison

    NASA Technical Reports Server (NTRS)

    Marbury, F.

    1975-01-01

    Floating craft are compared to those that fly. Drag/weight for floaters is shown to be proportional to v squared/L, while for flyers it is independent of size and speed. The transportation market will therefore assign airships to lower speeds than airplanes, and will favor large airship sizes. Drag of an airship is shown to be only 11 percent of submarine drag at equal displacement and speed, raising the possibility that airships can compete with some types of ships.

  7. Sonar location system for freely floating buoys

    NASA Astrophysics Data System (ADS)

    Bird, I. G.

    1983-05-01

    A rf interrogated sonar location system for freely floating buoys is described. The location of an array of up to three buoys may be determined on an almost continuous basis within a radius of 500 m from a shipboard monitoring station. Location accuracy of typically ±0.5 m at 200-m range, low cost, and ease of operation are the major features of the system.

  8. Time Variant Floating Mean Counting Algorithm

    Energy Science and Technology Software Center (ESTSC)

    1999-06-03

    This software was written to test a time variant floating mean counting algorithm. The algorithm was developed by Westinghouse Savannah River Company and a provisional patent has been filed on the algorithm. The test software was developed to work with the Val Tech model IVB prototype version II count rate meter hardware. The test software was used to verify the algorithm developed by WSRC could be correctly implemented with the vendor''s hardware.

  9. FPP [Floating Potential Probe] Results, Final Report

    NASA Technical Reports Server (NTRS)

    Ferguson, Dale C.

    2007-01-01

    The Floating Potential Probe (FPP) operated on the International Space Station (ISS) from December 2000 to April 2001. During that time, it took many measurements of the ISS floating potential and the electron density and temperature. Those measurements were used as inputs to the Environments WorkBench (EWB) model of ISS potentials (originally developed by SAIC, but now sometimes called the Boeing model) that is used even today to predict charging levels for ISS. FPP is now completely defunct, having been removed and ejected from ISS. With the advent of the new Floating Potential Monitoring Unit (FPMU) on ISS, and the beginning of ISS operations with two large solar array panels instead of just one, a review of FPP measurements can offer comparisons with the new FPMU data and perhaps improve the accuracy of future ISS charging predictions. In particular, FPP measurements during times of low electron temperature and high electron density (the times of worst ISS charging) will be brought forward for comparison with the newly obtained FPMU data.

  10. Floating debris in the Mediterranean Sea.

    PubMed

    Suaria, Giuseppe; Aliani, Stefano

    2014-09-15

    Results from the first large-scale survey of floating natural (NMD) and anthropogenic (AMD) debris (>2 cm) in the central and western part of the Mediterranean Sea are reported. Floating debris was found throughout the entire study area with densities ranging from 0 to 194.6 items/km(2) and mean abundances of 24.9 AMD items/km(2) and 6.9 NMD items/km(2) across all surveyed locations. On the whole, 78% of all sighted objects were of anthropogenic origin, 95.6% of which were petrochemical derivatives (i.e. plastic and styrofoam). Maximum AMD densities (>52 items/km(2)) were found in the Adriatic Sea and in the Algerian basin, while the lowest densities (<6.3 items/km(2)) were observed in the Central Tyrrhenian and in the Sicilian Sea. All the other areas had mean densities ranging from 10.9 to 30.7 items/km(2). According to our calculations, more than 62 million macro-litter items are currently floating on the surface of the whole Mediterranean basin. PMID:25127501

  11. Capillary effects on floating cylindrical particles

    NASA Astrophysics Data System (ADS)

    Dixit, Harish N.; Homsy, G. M.

    2012-12-01

    In this study, we develop a systematic perturbation procedure in the small parameter, B1/2, where B is the Bond number, to study capillary effects on small cylindrical particles at interfaces. Such a framework allows us to address many problems involving particles on flat and curved interfaces. In particular, we address four specific problems: (i) capillary attraction between cylinders on flat interface, in which we recover the classical approximate result of Nicolson ["The interaction between floating particles," Proc. Cambridge Philos. Soc. 45, 288-295 (1949), 10.1017/S0305004100024841], thus putting it on a rational basis; (ii) capillary attraction and aggregation for an infinite array of cylinders arranged on a periodic lattice, where we show that the resulting Gibbs elasticity obtained for an array can be significantly larger than the two cylinder case; (iii) capillary force on a cylinder floating on an arbitrary curved interface, where we show that in the absence of gravity, the cylinder experiences a lateral force which is proportional to the gradient of curvature; and (iv) capillary attraction between two cylinders floating on an arbitrary curved interface. The present perturbation procedure does not require any restrictions on the nature of curvature of the background interface and can be extended to other geometries.

  12. Multiview autosterescopic display with floating real image

    NASA Astrophysics Data System (ADS)

    Kakeya, Hideki; Kobe, Naoto; Kasano, Hidehiro

    2004-05-01

    This paper proposes multiview version of autostereoscopic display FLOATS (Fresnel Lens based Optical Apparatus for Touchable-distance Stereoscopy), which combines generation of floating real image and parallax presentation to show realistic 3-D image within the viewer's reach. Earlier versions of FLOATS have required a head tracker, physical motion control of filters or mirrors, and transformation of image in accordance with the viewer's motion to keep on presenting different images to each eye. To do away with these requirements, we propose two methods which realize multiview presentation to the viewer. One method is to use multiple LCD panels and multiple fixed mirrors instead of mobile mirrors. The other method is to use mutiple projectors, fly-eye lenses, and fresnel lenses. Though the former system doesn't cost much, it is not practical to present more than 10 views. In the latter system it is practical to present more than 30 views, which can realize presentation of both horizontal and vertical parallax. With this technology the viewers can perceive undistorted 3-D space from any angle, which makes it possible for multiple viewers to observe 3-D image at consistent position from different angles at the same time.

  13. Drill vessels float in aerated water

    SciTech Connect

    Hammett, D.S.

    1985-01-01

    Model tests, calculations, and case studies prove that a floating vessel will not sink due to gas reducing the water density in or adjacent to a subsea blowout. Several floating drill vessels have been lost as a result of subsea blowouts. Reports have circulated that the rig sank into something similar to a hole in the ocean caused by gas bubbles suspended in the water reducing its specific gravity. These erroneous reports, believed as truth by many people, have resulted in the modification of operations resulting in decreased safety. Several subsea well control operations have caused accidents and losses because the riser was not disconnected. This action was taken in fear of sinking in aerated water. The losses occurred because the vessel winched itself off the drill site to get away from the subsea well before disconnecting. Due to the high riser/BOP angle, the riser could not be disconnected and well control was later lost and the gas/oil flowed directly to the rig floor where massive fire/explosion damage occurred. If there had been a better understanding of water density, the rig personnel could have closed all hatches, shut-down all engines, disconnected the riser and released mooring lines at one end of the rig, and safely removed the rig out of the aerated water. This paper presents some of the technical data and references available which prove that a floating vessel will not sink due to loss of water density.

  14. Borofloat and Starphire Float Glasses: A Comparison

    SciTech Connect

    Wereszczak, Andrew A.; Anderson Jr., Charles E.

    2014-10-28

    Borofloat® borosilicate float glass and Starphire® soda-lime silicate float glass are used in transparent protective systems. They are known to respond differently in some ballistic and triaxial loading conditions, and efforts are underway to understand the causes of those differences. Toward that, a suite of test and material characterizations were completed in the present study on both glasses so to identify what differences exist among them. Compositional, physical properties, elastic properties, flaw size distributions and concentrations, tensile/flexure strength, fracture toughness, spherical indentation and hardness, transmission electron microscopy, striae, high pressure responses via diamond anvil cell testing, laser shock differences, and internal porosity were examined. Differences between these two float glasses were identified for many of these properties and characteristics, and the role of three (striae, high pressures where permanent densification can initiate, and sub-micron-sized porosity) lack understanding and deserve further attention. Lastly, the contributing roles of any of those properties or characteristics to triaxial or ballistic loading responses are not definitive; however, they provide potential correlations that may lead to improved understanding and management of loading responses in glasses used in transparent protective systems.

  15. Borofloat and Starphire Float Glasses: A Comparison

    DOE PAGESBeta

    Wereszczak, Andrew A.; Anderson Jr., Charles E.

    2014-10-28

    Borofloat® borosilicate float glass and Starphire® soda-lime silicate float glass are used in transparent protective systems. They are known to respond differently in some ballistic and triaxial loading conditions, and efforts are underway to understand the causes of those differences. Toward that, a suite of test and material characterizations were completed in the present study on both glasses so to identify what differences exist among them. Compositional, physical properties, elastic properties, flaw size distributions and concentrations, tensile/flexure strength, fracture toughness, spherical indentation and hardness, transmission electron microscopy, striae, high pressure responses via diamond anvil cell testing, laser shock differences, andmore » internal porosity were examined. Differences between these two float glasses were identified for many of these properties and characteristics, and the role of three (striae, high pressures where permanent densification can initiate, and sub-micron-sized porosity) lack understanding and deserve further attention. Lastly, the contributing roles of any of those properties or characteristics to triaxial or ballistic loading responses are not definitive; however, they provide potential correlations that may lead to improved understanding and management of loading responses in glasses used in transparent protective systems.« less

  16. Physical implication of transition voltage in organic nano-floating-gate nonvolatile memories

    NASA Astrophysics Data System (ADS)

    Wang, Shun; Gao, Xu; Zhong, Ya-Nan; Zhang, Zhong-Da; Xu, Jian-Long; Wang, Sui-Dong

    2016-07-01

    High-performance pentacene-based organic field-effect transistor nonvolatile memories, using polystyrene as a tunneling dielectric and Au nanoparticles as a nano-floating-gate, show parallelogram-like transfer characteristics with a featured transition point. The transition voltage at the transition point corresponds to a threshold electric field in the tunneling dielectric, over which stored electrons in the nano-floating-gate will start to leak out. The transition voltage can be modulated depending on the bias configuration and device structure. For p-type active layers, optimized transition voltage should be on the negative side of but close to the reading voltage, which can simultaneously achieve a high ON/OFF ratio and good memory retention.

  17. Floating Oil-Spill Containment Device

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.

    2012-01-01

    Previous oil containment booms have an open top that allows natural gas to escape, and have significant oil leakage due to wave action. Also, a subsea pyramid oil trap exists, but cannot move relative to moving oil plumes from deepsea oil leaks. The solution is to have large, moveable oil traps. One version floats on the sea surface and has a flexible tarp cover and a lower weighted skirt to completely entrap the floating oil and natural gas. The device must have at least three sides with boats pulling at each apex, and sonar or other system to track the slowly moving oil plume, so that the boats can properly locate the booms. The oil trap device must also have a means for removal of the oil and the natural gas. A second design version has a flexible pyramid cover that is attached by lines to ballast on the ocean floor. This is similar to fixed, metal pyramid oil capture devices in the Santa Barbara Channel off the coast of California. The ballast lines for the improved design, however, would have winches that can move the pyramid to always be located above the oil and gas plume. A third design is a combination of the first two. It uses a submerged pyramid to trap oil, but has no anchor and uses boats to locate the trap. It has ballast weights located along the bottom of the tarp and/or at the corners of the trap. The improved floating oil-spill containment device has a large floating boom and weighted skirt surrounding the oil and gas entrapment area. The device is triangular (or more than three sides) and has a flexible tarp cover with a raised gas vent area. Boats pull on the apex of the triangles to maintain tension and to allow the device to move to optimum locations to trap oil and gas. The gas is retrieved from a higher buoyant part of the tarp, and oil is retrieved from the floating oil layer contained in the device. These devices can be operated in relatively severe weather, since waves will break over the devices without causing oil leaking. Also, natural

  18. Integrated use of spatial and semantic relationships for extracting road networks from floating car data

    NASA Astrophysics Data System (ADS)

    Li, Jun; Qin, Qiming; Xie, Chao; Zhao, Yue

    2012-10-01

    The update frequency of digital road maps influences the quality of road-dependent services. However, digital road maps surveyed by probe vehicles or extracted from remotely sensed images still have a long updating circle and their cost remain high. With GPS technology and wireless communication technology maturing and their cost decreasing, floating car technology has been used in traffic monitoring and management, and the dynamic positioning data from floating cars become a new data source for updating road maps. In this paper, we aim to update digital road maps using the floating car data from China's National Commercial Vehicle Monitoring Platform, and present an incremental road network extraction method suitable for the platform's GPS data whose sampling frequency is low and which cover a large area. Based on both spatial and semantic relationships between a trajectory point and its associated road segment, the method classifies each trajectory point, and then merges every trajectory point into the candidate road network through the adding or modifying process according to its type. The road network is gradually updated until all trajectories have been processed. Finally, this method is applied in the updating process of major roads in North China and the experimental results reveal that it can accurately derive geometric information of roads under various scenes. This paper provides a highly-efficient, low-cost approach to update digital road maps.

  19. An Analysis of the Full-Floating Journal Bearing

    NASA Technical Reports Server (NTRS)

    Shaw, M C; Nussdorfer, T J , Jr

    1947-01-01

    An analysis of the operating characteristics of a full-floating journal bearing, a bearing in which a floating sleeve is located between the journal and bearing surfaces, is presented together with charts from which the performance of such bearings may be predicted. Examples are presented to illustrate the use of these charts and a limited number of experiments conducted upon a glass full-floating bearing are reported to verify some results of the analysis.

  20. Characteristics of a micromachined floating-gate high-electron-mobility transistor at 4.2 K

    NASA Astrophysics Data System (ADS)

    Teh, W. H.; Crook, R.; Smith, C. G.; Beere, H. E.; Ritchie, D. A.

    2005-06-01

    We use micromachined, free-standing Ni cantilevers to develop a mechanical field-effect transistor based on III-V material systems. The device consists of an electrostatically actuated microcantilever, acting as the floating gate, fabricated over a defined two-dimensional electron gas (2DEG) in a modulation-doped GaAs /AlGaAs heterostructure. The gating effects on the conductance of the 2DEG channel of the biased floating gate at different operating points are studied at 4.2K. Preliminary resonance measurements based on the 2DEG as a deflection sensor are presented.

  1. Evaluation and floating enhancement of levodopa sustained release floating minitablets coated with insoluble acrylic polymer.

    PubMed

    Goole, J; Amighi, K; Vanderbist, F

    2008-08-01

    This article describes the in vitro evaluation and the enhancement of the floating properties of coated sustained release (SR) minitablets (MTs). The evaluated system consisted of a 3-mm drug-containing gas-generating core prepared by melt granulation and subsequent compression, which was then coated with a flexible polymeric membrane. Eudragit RL30D and acetyl triethylcitrate were used as a film former and a plasticizer, respectively. The coating level was fixed at 20% (wt/wt). The optimally coated floating MTs floated within 10 min and remained buoyant for more than 13 h, regardless of the pH of the test medium. By evaluating the dissolution profiles of levodopa at different pH, it was found that the release of levodopa was sustained for more than 12 h regardless of the pH, even if the coating did not cancel the effect of the pH-dependent solubility of the active drug. Finally, the robustness of the coated floating MTs was assessed by testing the drug release variability in function of the stirring conditions during dissolution tests. PMID:18618310

  2. Development and in vivo floating behavior of verapamil HCl intragastric floating tablets.

    PubMed

    Patel, Anand; Modasiya, Moin; Shah, Dushyant; Patel, Vishnu

    2009-01-01

    A novel gastro retentive controlled release drug delivery system of verapamil HCl was formulated in an effort to increase the gastric retention time of the dosage form and to control drug release. Hydroxypropylmethylcellulose (HPMC), carbopol, and xanthan gum were incorporated for gel-forming properties. Buoyancy was achieved by adding an effervescent mixture of sodium bicarbonate and anhydrous citric acid. In vitro drug release studies were performed, and drug release kinetics was evaluated using the linear regression method. The optimized intragastric floating tablet composed of 3:2 of HPMC K4M to xanthan gum exhibited 95.39% drug release in 24 h in vitro, while the buoyancy lag time was 36.2 s, and the intragastric floating tablet remained buoyant for >24 h. Zero-order and non-Fickian release transport was confirmed as the drug release mechanism from the optimized formulation (F7). X-ray studies showed that total buoyancy time was able to delay the gastric emptying of verapamil HCl intragastric floating tablet in mongrel dogs for more than 4 h. Optimized intragastric floating tablet showed no significant change in physical appearance, drug content, total buoyancy time, or in vitro dissolution pattern after storage at 40 degrees C/75% relative humidity for 3 months. PMID:19296224

  3. Floating air riding seal for a turbine

    DOEpatents

    Ebert, Todd A

    2016-08-16

    A floating air riding seal for a gas turbine engine with a rotor and a stator, an annular piston chamber with an axial moveable annular piston assembly within the annular piston chamber formed in the stator, an annular cavity formed on the annular piston assembly that faces a seal surface on the rotor, where the axial moveable annular piston includes an inlet scoop on a side opposite to the annular cavity that scoops up the swirling cooling air and directs the cooling air to the annular cavity to form an air cushion with the seal surface of the rotor.

  4. Floating production unit to work off Brazil

    SciTech Connect

    Not Available

    1992-10-19

    This paper reports that Petroleo Brasileiro SA expects by early November to deploy its Petrobras XXIV floating production unit (FPU) in about 900 ft of water in Albacora field off Brazil. The FPU was scheduled to depart Galveston, Tex., this month, following completion of modifications and upgrades under a turnkey contract with Chiles Offshore International Inc. Chiles began modifying Petrobras XXIV about 1 year ago as part of a deal closed in October 1991 in which Chiles Offshore Corp. sold the vessel, then known as Intrepid, to Brasoil, the international subsidiary of Petrobras.

  5. Floating hydrometer with energy dissipating baffle

    SciTech Connect

    Kownurko, W.A.

    1987-11-24

    This patent describes a floating hydrometer employable for purposes of obtaining measurements of the presence of suspended solids in a fluid substance contained in a receptacle comprising: a. a probe portion operative as an instrument-bearing housing; b. an elongated tubular element having a hollow interior and at least one open end so as to enable the flow into the hollow interior of the elongated tubular element through the open end; and c. energy dissipating baffle means having a first mode of action and a second mode of action and including a member having a hollow interior.

  6. Analysis of a Near-Free-Floating Vibration Isolation Platform

    NASA Astrophysics Data System (ADS)

    Regehr, M.

    2015-02-01

    Pointing control for deep-space lasercom is expected to be challenging because, for the apertures and wavelengths contemplated (of order 20 cm and 1 micrometer, respectively), the width of the beam transmitting data to Earth will be of order a few microradians. To address this challenge, JPL and others have been developing a vibration isolation system in which the lasercom telescope is nearly free-floating next to the spacecraft, being physically connected to the spacecraft only by a set of flexible wires and fibers referred to as an umbilical. The telescope's position relative to the spacecraft is sensed by noncontact sensors and the telescope is controlled by noncontact (voice coil) actuators. The telescope pointing error, relative to Earth, is also sensed by a pointing detector in the telescope, which images an Earth-based laser beacon. The telescope moves in six degrees of freedom, of which two (pitch and yaw) are the pointing of the telescope, and are of principal importance. This article describes a controller for controlling the telescope, and a simplified method of analyzing the closed-loop behavior of the system. Several mechanisms for cross-coupling between the degrees of freedom are present, including off-diagonal elements in the umbilical spring constant matrix, and the telescope having significant products of inertia; as a result, the dynamics of the closed-loop system are described by a full 6 by 6 transfer matrix. Approximations that take into account only one or two cross-coupling mechanisms at a time, however, and which result in block-diagonal models for the system, provide excellent agreement with the full model. These approximations provide insight useful for designing the controller, and numerical models indicate that a controller designed using these approximations provides performance that meets pointing requirements.

  7. Modal testing variability of spherical marine floats.

    SciTech Connect

    Robertson, A. N.; Hemez, F. M.; Salazar, I. F.; Duffey, T. A.

    2004-01-01

    This study investigates the variability in modal data obtained from testing a set of hollow, almost spherical marine floats. Four sources of variability are investigated: unit-to -unit variability, operator-to-operator variability, test repetition, and accelerometer placement. Because moving the accelerometers implies a test setup reconfiguration, it is expected that variability due to accelerometer placement should encompass variability due to test repetition. Similarly, the unit-to-unit variability should encompass both accelerometer placement variability and test-to -test variability. Impulse and frequency response functions are estimated from the measured excitation and response of the marine floats. A series of techniques are then used to assess the variation of the modal properties between each test, including: a measure of the spread of the frequency response functions in each test group; the variation of the temporal moments, spectral moments, and principal components; and the variability of resonant frequencies and modal damping ratios extracted from the data. The effects of mass and geometry on variability are also investigated. A strong correlation between the frequency and mass is found for the fundamental mode only. The main conclusion is that the majority of analysis techniques find the unit-to-unit variability to be the largest by a significant margin. The second largest is the variability caused by accelerometer placement. Next are the operator-to-operator variability and test-to -test variability.

  8. Water-Pressure Distribution on Seaplane Float

    NASA Technical Reports Server (NTRS)

    Thompson, F L

    1929-01-01

    The investigation presented in this report was conducted for the purpose of determining the distribution and magnitude of water pressures likely to be experienced on seaplane hulls in service. It consisted of the development and construction of apparatus for recording water pressures lasting one one-hundredth second or longer and of flight tests to determine the water pressures on a UO-1 seaplane float under various conditions of taxiing, taking off, and landing. The apparatus developed was found to operate with satisfactory accuracy and is suitable for flight tests on other seaplanes. The tests on the UO-1 showed that maximum pressures of about 6.5 pounds per square inch occur at the step for the full width of the float bottom. Proceeding forward from the step the maximum pressures decrease in magnitude uniformly toward the bow, and the region of highest pressures narrows toward the keel. Immediately abaft the step the maximum pressures are very small, but increase in magnitude toward the stern and there once reached a value of about 5 pounds per square inch. (author)

  9. Evaporation mitigation by floating modular devices

    NASA Astrophysics Data System (ADS)

    Hassan, M. M.; Peirson, W. L.

    2016-05-01

    Prolonged periods of drought and consequent evaporation from open water bodies in arid parts of Australia continue to be a threat to water availability for agricultural production. Over many parts of Australia, the annual average evaporation exceeds the annual precipitation by more than 5 times. Given its significance, it is surprising that no evaporation mitigation technique has gained widespread adoption to date. High capital and maintenance costs of manufactured products are a significant barrier to implementation. The use of directly recycled clean plastic containers as floating modular devices to mitigate evaporation has been investigated for the first time. A six-month trial at an arid zone site in Australia of this potential cost effective solution has been undertaken. The experiment was performed using clean conventional drinking water bottles as floating modules on the open water surface of 240-L tanks with three varying degrees of covering (nil, 34% and 68%). A systematic reduction in evaporation is demonstrated during the whole study period that is approximately linearly proportional to the covered surface. These results provide a potential foundation for robust evaporation mitigation with the prospect of implementing a cost-optimal design.

  10. Thermal Performance of the LDX Floating Coil

    NASA Astrophysics Data System (ADS)

    Zhukovsky, A.; Garnier, D. T.; Radovinsky, A. L.

    2006-04-01

    The Levitated Dipole Experiment (LDX) is an innovative facility to study plasma confinement in a dipole magnetic field, created by a superconducting solenoid (floating coil), which is magnetically levitated in the center of a 5 m diameter by 3 m tall vacuum chamber. The floating coil (F-coil) consists of a Nb3Sn magnet installed inside a strong vessel filled with high-pressure helium gas at room temperature. It is surrounded by a fiberglass-lead composite radiation shield and by a toroidal vacuum shell. The cryostat design provides the ability to operate the magnet for several hours of wanning while suspended in the middle of the vacuum chamber without electric and cryogenic connections to the coil. For this reason the magnet is charged/discharged inductively in a lower part of the vacuum chamber. The retractable cryogenic transfer lines serve to cool down the magnet to 4.5 K before it is lifted to the operating position. The F-coil can be re-cooled multiple times while maintaining its field and current. This paper describes the thermal performance of the F-coil.

  11. Drilling and production from a floating spar

    SciTech Connect

    Brooks, I.H.; Carroll, J.P.

    1994-12-31

    A deepwater drilling and production platform has been designed based on a floating spar. The spar is a catenary-moored cylindrical vessel having a deep draft which minimizes heave motions. The concept is an economic competitor with other deep water designs such as compliant towers and tension leg platforms. The spar`s oil storage capacity makes it particularly applicable for remote areas where pipeline infrastructure is unavailable and production is primarily from oil reservoirs. Without the need for a swivel, offloading of oil can be accomplished either directly from the spar, by use of a floating hose and support vessel, or by transfer to an offloading buoy. The concept is compatible with early production or phased development scenarios, permits surface completions of producing and injection wells, and allows for direct well intervention. The ability to reposition the spar by manipulations of the mooring lines favors a system of individual wellheads on the seafloor. Wells can be drilled, completed, and produced without pulling the drilling riser. When production from the field reaches its economic limit, the entire system can be towed to a new location and reused.

  12. Floating treatment wetlands for domestic wastewater treatment.

    PubMed

    Faulwetter, J L; Burr, M D; Cunningham, A B; Stewart, F M; Camper, A K; Stein, O R

    2011-01-01

    Floating islands are a form of treatment wetland characterized by a mat of synthetic matrix at the water surface into which macrophytes can be planted and through which water passes. We evaluated two matrix materials for treating domestic wastewater, recycled plastic and recycled carpet fibers, for chemical oxygen demand (COD) and nitrogen removal. These materials were compared to pea gravel or open water (control). Experiments were conducted in laboratory scale columns fed with synthetic wastewater containing COD, organic and inorganic nitrogen, and mineral salts. Columns were unplanted, naturally inoculated, and operated in batch mode with continuous recirculation and aeration. COD was efficiently removed in all systems examined (>90% removal). Ammonia was efficiently removed by nitrification. Removal of total dissolved N was ∼50% by day 28, by which time most remaining nitrogen was present as NO(3)-N. Complete removal of NO(3)-N by denitrification was accomplished by dosing columns with molasses. Microbial communities of interest were visualized with denaturing gradient gel electrophoresis (DGGE) by targeting specific functional genes. Shifts in the denitrifying community were observed post-molasses addition, when nitrate levels decreased. The conditioning time for reliable nitrification was determined to be approximately three months. These results suggest that floating treatment wetlands are a viable alternative for domestic wastewater treatment. PMID:22105133

  13. Evaporation mitigation using floating modular devices

    NASA Astrophysics Data System (ADS)

    Hassan, M. Mahmudul; Peirson, William Leslie; Neyland, Bryce M.; Fiddis, Nicholas McQuistan

    2015-11-01

    Reducing evaporation losses from open water storages is of paramount importance in the improvement of water security in arid countries, including Australia. Widespread adoption of evaporation mitigation techniques has been prevented by their high capital and maintenance or operating costs. The use of clean, floating recycled materials to mitigate evaporation technique has been investigated systematically at sites within both the coastal and semi-arid zones of Australia. Evaporation reduction systematically increases with the proportion of covered surface. Evaporation is reduced by 43% at coastal site and 37% at arid zone site at the maximum packing densities achievable for a single layer of floating devices. The study highlights the importance of both long-term investigations and the climatic influences in the robust quantification of evaporation mitigation. The effects of solar radiation, temperature, wind speed and relative humidity on the evaporation rate at both study sites have been determined in terms of both the classical Penman model and FAO Penman Monteith model with corresponding pan coefficients quantified. FAO Penman Monteith model better estimates evaporation from the open reference tank.

  14. A laboratory study of floating lenticular anticyclones

    NASA Astrophysics Data System (ADS)

    Le Gal, Patrice; de La Rosa, Hector; Cros, Anne; Cruz-Gomez, Raúl; Le Bars, Michael

    2014-11-01

    Oceanic vortices play an important role in the redistribution of heat, salt and momentum in the oceans. Among these vortices, floating lenses or rings are often met in the meanders of warm currents. For instance the North Brazil Current rings are among the most intense and large anticyclonic vortices on Earth. In order to better describe these vortices, we propose here a laboratory study of these floating anticyclonic lenses. A blob of fresh water is slowly injected near the surface of a rotating layer of homogeneous salted water. Because of the opposite effects of rotation that tends to generate columnar structures and density stratification that spreads light water on the surface, the vortices take a finite size three dimensionnal typical shape. Visualization and PIV measurements of the shape, aspect ratios and vorticity profiles are compared to analytical predictions that use first a simple solid body rotation model and then a more realistic isolated Gaussian vorticity field inside the anticyclones. This work was carried out within the framework of a bilateral cooperation between CNRS (France) and CONACYT (Mexico).

  15. 14 CFR 23.535 - Auxiliary float loads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Auxiliary float loads. 23.535 Section 23.535 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Water Loads § 23.535 Auxiliary float loads. (a)...

  16. 22. Float located adjacent to entry stair in filtration bed. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. Float located adjacent to entry stair in filtration bed. The float actuates a valve that maintains water level over the bed. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  17. 40 CFR 65.44 - External floating roof (EFR).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 16 2012-07-01 2012-07-01 false External floating roof (EFR). 65.44 Section 65.44 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE Storage Vessels § 65.44 External floating roof (EFR). (a) EFR design requirements. The owner or operator...

  18. 40 CFR 63.1043 - Standards-Separator floating roof.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Standards-Separator floating roof. 63...) National Emission Standards for Oil-Water Separators and Organic-Water Separators § 63.1043 Standards—Separator floating roof. (a) This section applies to owners and operators subject to this subpart...

  19. 14 CFR 136.11 - Helicopter floats for over water.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Helicopter floats for over water. 136.11... floats for over water. (a) A helicopter used in commercial air tours over water beyond the shoreline must... controls, and (2) The flotation system armed when the helicopter is over water and is flying at a...

  20. 14 CFR 136.11 - Helicopter floats for over water.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Helicopter floats for over water. 136.11... floats for over water. (a) A helicopter used in commercial air tours over water beyond the shoreline must... controls, and (2) The flotation system armed when the helicopter is over water and is flying at a...

  1. 14 CFR 136.11 - Helicopter floats for over water.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Helicopter floats for over water. 136.11... floats for over water. (a) A helicopter used in commercial air tours over water beyond the shoreline must... controls, and (2) The flotation system armed when the helicopter is over water and is flying at a...

  2. 14 CFR 136.11 - Helicopter floats for over water.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Helicopter floats for over water. 136.11... floats for over water. (a) A helicopter used in commercial air tours over water beyond the shoreline must... controls, and (2) The flotation system armed when the helicopter is over water and is flying at a...

  3. 14 CFR 136.11 - Helicopter floats for over water.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Helicopter floats for over water. 136.11... floats for over water. (a) A helicopter used in commercial air tours over water beyond the shoreline must... controls, and (2) The flotation system armed when the helicopter is over water and is flying at a...

  4. 33 CFR 144.01-1 - Life floats.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Life floats. 144.01-1 Section 144.01-1 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OUTER CONTINENTAL SHELF ACTIVITIES LIFESAVING APPLIANCES Manned Platforms § 144.01-1 Life floats. Each...

  5. 14 CFR 27.521 - Float landing conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ....473(b) or assumed to be equal to that determined for wheel landing gear): (a) Up-load conditions in... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Float landing conditions. 27.521 Section 27... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Water Loads § 27.521 Float...

  6. 14 CFR 29.521 - Float landing conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... factor is determined under § 29.473(b) or assumed to be equal to that determined for wheel landing gear... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Float landing conditions. 29.521 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Water Loads § 29.521 Float...

  7. 14 CFR 27.521 - Float landing conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Float landing conditions. 27.521 Section 27.521 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Water Loads § 27.521 Float landing conditions. If certification for...

  8. 14 CFR 29.521 - Float landing conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Float landing conditions. 29.521 Section 29.521 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Water Loads § 29.521 Float landing conditions. If certification for...

  9. 14 CFR 29.521 - Float landing conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... factor is determined under § 29.473(b) or assumed to be equal to that determined for wheel landing gear... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Float landing conditions. 29.521 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Water Loads § 29.521 Float...

  10. 14 CFR 27.521 - Float landing conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ....473(b) or assumed to be equal to that determined for wheel landing gear): (a) Up-load conditions in... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Float landing conditions. 27.521 Section 27... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Water Loads § 27.521 Float...