Accuracy Of Plus Research Articles

CREEP TEST FOR OVERHEAD CONDUCTORS USING DEADWEIGHT ACTUATED LEVER

Having a device that does not need an electric, pneumatic, or hydraulic actuator neither a digital control to work for a specific task is the goal for any application. This research shows that it is feasible to develop a device with the above characteristics to apply creep tests for overhead conductors. There are two primary creep test methods for Aluminum Conductors in Overhead Lines (ACSR (aluminum conductor, Steel reinforced)) to obtain the tensile creep characteristics. They are the European standard IEC 61395, "Creep test Procedures for stranded conductors" and "Method for Determining the Long Time Tensile Creep of Aluminum Conductor in Overhead Line," prepared by the Electrical Committee of The Aluminum Association. Since both methods don't specify a convenient type of mechanism or specimen position to carry out the creep test and accomplish the tensile load accuracy requirement, this research aims to design a self-tensile lever controllable to an accuracy of plus and minus 1% according to IEC 61395. This work's analysis focuses on the lever geometry parameters type I actuated by deadweights to meet the tensile load accuracy for specimen lengths of 2.5m and 12.5m. Calculations of accuracy development of lever geometry for both selected conductor lengths apply by analytical and numerical methods and, finally, laboratory tests.

Phenotypic characteristics of native edible snails Achatina fulica and Archachatina marginata in equatorial region of Cameroon

Between February and May 2019, in the equatorial forest urbanized area of Cameroon (Mfoundi), a study was conducted and aimed to contribute on a better understanding of the biodiversity of edible snails for their genetic improvement and conservation. A total of 693 adult snails of two species: Archachatina marginata and Achatina fulica were collected in the various localities (Odza, Mbankolo, Biyem-assi, Nyom, Nkolbisson and Simbok). Information about biometric morpho characters was collected using a survey sheet, an electronic scale of 7000g capacity with accuracy of plus or minus 1g, a sliding foot with an accuracy of plus or minus 0.01 millimeter. A digital camera will be used for the subsequent morphological assessment of the animals. Results revealed significant influence of locality on all the morphobiometric characteristics. The shell color of A. marginata was black with yellowish stripes and the red tip was the most frequent (62.85%); while for the species A. fulica it was brown with white stripes and white tip (76.09%). The most common color of the foot in A. marginata was brown with white traces (41.70%) and in A. fulica, it was black (82.50%). The number of shell turns in A. marginata was higher in the localities of Mbankolo (5.36±0.12) and Odza (5.38±0.05) while in A. fulica it was higher in the locality of Simbok (7.41±0.49). Concerning body measurements (in mm), the total body length of A. marginata was higher in Nkolbisson (88.10±1.30) and that of A. fulica was greater in Simbok (112.25±12.16). The live weight (g) of A. marginata was higher in Mbankolo (70±0.00) on the other hand, that of A. fulica was higher in Simbok (80±0.02) and Nyom (80±0.12). The diversity observed suggests that edible snails constitutes rich natural genetic resources enough variability to envisage genetic improvement and develop preservation schemes for these snails mostly collected from wild

Novel linear piezoelectric motor for precision position stage

Conventional servomotor and stepping motor face challenges in nanometer positioning stages due to the complex structure, motion transformation mechanism, and slow dynamic response, especially directly driven by linear motor. A new butterfly-shaped linear piezoelectric motor for linear motion is presented. A two-degree precision position stage driven by the proposed linear ultrasonic motor possesses a simple and compact configuration, which makes the system obtain shorter driving chain. Firstly, the working principle of the linear ultrasonic motor is analyzed. The oscillation orbits of two driving feet on the stator are produced successively by using the anti-symmetric and symmetric vibration modes of the piezoelectric composite structure, and the slider pressed on the driving feet can be propelled twice in only one vibration cycle. Then with the derivation of the dynamic equation of the piezoelectric actuator and transient response model, start-upstart-up and settling state characteristics of the proposed linear actuator is investigated theoretically and experimentally, and is applicable to evaluate step resolution of the precision platform driven by the actuator. Moreover the structure of the two-degree position stage system is described and a special precision displacement measurement system is built. Finally, the characteristics of the two-degree position stage are studied. In the closed-loop condition the positioning accuracy of plus or minus <0.5 μm is experimentally obtained for the stage propelled by the piezoelectric motor. A precision position stage based the proposed butterfly-shaped linear piezoelectric is theoretically and experimentally investigated.

Study of Equivalent Strength and Effects of the Type of Multi-story Steel Braced Frames

In recent years, the terrible earthquake events that are not expected in the design process have occurred in the world. So, it is necessary to estimate the seismic performance accurately. This paper focuses on the energy absorbing efficiency of steel braced frames. Steel brace members in frames show the complicated and unstable behavior because many kinds of buckling and fractures are combined. And evaluation method of restoring force characteristics and capacity have been studied in enormous past researches, however, there are some problems to adopt for seismic design procedure. Also the response characteristics of steel braced frames are affected by the interaction between frames and braces. This paper suggests the analytical method to evaluate the energy absorbing efficiency of steel braced frames as equivalent strength. The equivalent strength is formulated with yield shear coefficient of the frame and slenderness ratio of the brace. Also, to verify the applicability of multi-story steel braced frames response analysis of two types of 5-story steel braced frames (X bracing, inverted-V bracing) is conducted. As compared with energy absorbing efficiency of the response analysis result, it is confirmed that the equivalent strength can be accuracy of plus or minus 20 percent or so.

An early-warning system for your bike

In the summer months, I really enjoy riding a bike along some of the flatter roads and trails around my small Vermont town. But sharing some of those roads with cars can be a dicey proposition. There’s one dirt road in particular, where no matter how often I scan my mirror or sneak a look over my shoulder, it seems that sooner or later I get surprised by a car zipping by. I’ve often imagined fitting an ultrasonic sensor to the bike to warn me of incoming traffic, but most of those have a range of less than 10 meters, which is worse than even my mediocre human senses. A lidar—similar to a radar system, but with laser pulses instead of radio waves—would have the longer range I need, but lidars have traditionally been too expensive for my biking needs. • This changed last year when startup PulsedLight, of Bend, Ore., announced Lidar-lite, a crowdfunded lidar detector less than half the size of a deck of cards, with a range of up to 40 meters and an accuracy of plus or minus 2.5 centimeters, all for US $89.

The Primer Extension Assay

In the primer extension assay, the transcription start site for a gene is determined experimentally by identifying the 5' end of the encoded messenger RNA (mRNA). The protocol begins with a primer, usually a synthetic oligonucleotide of about 20 residues, that is complementary to an mRNA sequence ∼50-150 nucleotides downstream of the anticipated 5' end. The primer is 5'-end-labeled using [γ-(32)P]ATP and T4 polynucleotide kinase and is annealed to the specific mRNA molecules within an RNA sample. Reverse transcriptase (RT), deoxyribonucleoside triphosphates, and appropriate buffer components are added to the primer-mRNA hybrids to catalyze elongation of the primer to the 5' end of the mRNA. The resulting radiolabeled complementary DNA (cDNA) products are analyzed by denaturing polyacrylamide gel electrophoresis, followed by autoradiography. The sizes of the bands detected on the gel, as compared to an adjacent sequencing ladder or molecular weight standards, provide a measure of the distance from the 5' end of the synthetic oligonucleotide to the beginning of the mRNA transcripts. In theory, the 3' end of the cDNA will coincide with the 5' end of the mRNA. Thus, the size of the radiolabeled cDNAs should represent the distance from the labeled 5' end of the primer to the 5' end of the mRNA (i.e., the 3' end of the cDNA). If the labeled cDNA products are within the resolution range of the gel, the transcription start site can be determined with an accuracy of plus or minus one nucleotide.

Using nonlinear dynamics to predict Old Faithful

The current algorithm for predicting eruptions of Old Faithful is observation-based and has an accuracy of plus or minus ten minutes. In this paper, we analyze eruption data from a nonlinear dynamics perspective and develop a mathematical prediction model based on the discrete logistics map. We compare our predictions of the data with those from the observation-based algorithm. We conclude that although our algorithm is not as practical for use in the park setting, it is competitive with the current one.

Development of a relocatable frame technique for gamma knife radiosurgery

Object. One of the limiting factors in gamma knife radiosurgery is the restriction to one treatment imposed by the fixed stereotactic frame. The ability, in selected cases, to remove the frame and replace it on a subsequent occasion in the same location would facilitate fractionated treatments and provide flexibility in the timing of treatment delivery. It is the purpose of this work to investigate techniques for frame fixation and for essential verification of frame position once it has been reapplied. Methods. A technique is proposed that requires four surgical self-tapping screws to be inserted into the skull. Aluminum pins are inserted through the frame pillars and are tightened against the head of the screws, providing a firm fixation of the frame. Pin lengths are recorded on gauges to ensure reproducibility of the position. In phantom tests, test objects were localized (using the angiographic localizer) before and after each of five frame removal/reapplications to test the reproducibility of frame position. The mean error in the observed target coordinates was 0.3 mm and the maximum error observed was 0.7 mm, indicating that the frame can be reapplied with some confidence. Repetition of bubble skull measurements has been investigated as a means of verifying that the frame was repositioned correctly; however, reproducibility of patient measurements was found to be poor even when no frame movement had occurred. In contrast, the use of a radiotherapy simulator to obtain repeated lateral and anteroposterior projections of the head was shown to be capable of detecting frame movements of as little as 1 mm. Conclusions. Using this technique of frame application facilitates the reapplication of the frame with an accuracy of plus or minus 0.7 mm. Bubble measurements are inadequate for the detection of frame movement. Simple techniques in which a radiotherapy simulator is used can verify correct frame placement and indicate frame movements of less than 1 mm.

Development of a Construction Robot for Marking on Ceiling Boards. 2nd Report. Drawing a Long Straight Line on the Ceiling.

The authors have proposed a marking robot which draws specific marks at designated positions on a ceiling board at construction siteS. After that, a new function was added to the robot. It is necessary to be work which draws a reference straight-line to a ceiling board in building construction sites. This report proposes about the method which makes this task do for a mobile robot. The system is composed of the standard laser, the prototype of Straight-line Drawing Unit (SLD Unit) which has a function of tracking the laser beam and a function of drawing, and the mobile robot. The robot loads the SLD Unit and moves toward the standard laser. In order to catch the standard laser beam, the robot changes its trajectory. The robot controls its two drive wheels in a way that allows each wheel to move independently, so it can trace a straight line. Based on the experiments, the robot could the task of drawing the amplitude of the straight line with an accuracy of plus or minus 1 mm when drawing a 10 m line. This paper mainly describes the SLD Unit and the wheel control, and presents the experimental results of marking by the robot.

Conversion of a head-mounted microphone signal intocalibrated SPL units

A method is reviewed for conversion of a microphone signal into calibrated Sound Pressure Level (SPL) units. The method follows American National Standards Institute (ANSI) standard for S1.4 SPL meters and requires an accurate SPL meter and an accurate calibration sound source for conversion. Accuracy and validation data from test signals and human phonation are provided. The results indicate that under typical speech conditions, an absolute accuracy of plus or minus 1.6 dB (type 1 SPL meter) can be obtained with a miniature head-mounted microphone.

Automated Torque Sensing Equipment for Cosmetics and Pharmaceuticals

The limited accuracy of existing closure torque testers and the subjectivity of the measurements imparted by human operators has led to the development of an automated closure testing machine, the Auto-Torque.As packaging requirements become more stringent in order to provide Improved consumer safety and product integrity, improved quality control techniques become necessary. Torque testing of closures has relied for years on a manually operated spring scale with a claimed accuracy of plus or minus four percent (4%) full scale. The closure testing process becomes more inaccurate when you add to this error the inconsistencies due to reading errors, data entry/analysis errors, and operator technique (1). Automation of the closure torque testing process narrows the range of errors down to those of the machine itself which are easily quantified by a calibration procedure.Currently available spring scale closure testers have no provision for measuring downward force needed to engage child-resistant (CR) closures, requiring the user to develop their own apparatus (2). Currently, the Auto-Torque is being used for university research and by major pharmaceutical companies in both the package development and quality assurance test area to support the productivity of multiple lines.This paper describes the Auto-Torque's ability to provide the quality assurance needed In the closure torque testing process. Technical problems encountered and their solutions are viewed from a general systems automation perspective.

Abundance analyses of metal-poor stars. IV - Improved red spectra of six dwarfs and three giants

A consistent set of iron abundance analyses with respect to the sun is extended to a group of primarily cool metal-poor field stars: three giants, HD 21581, BD -1 deg 1792, and HD 210295, and six dwarfs, BD -17 deg 219, HD 13783, HD 23439 A and B, HD 25329, and BD -0 deg 4234. The use of the long-focus camera with the high-dispersion echelle grating on the 4-m echelle spectrograph of Kitt Peak National Observatory has made it possible to extend reliable abundance determinations to those elements represented only by very weak or very few lines. This and the internal accuracy of plus or minus 0.10 dex in the abundances deduced here for the dwarfs have aided a separate discussion of the relative distribution of the abundances of elements in metal-poor stars.

Evaluation of severinghaus' equation and its modification for 2, 3-dpg.

Severinghaus' equation can safely be used for the indirect estimation of oxygen half saturation pressure (P50) on the basis of blood gas parameters in normal subjects. However, 139 blood samples from 65 patients with severe injuries, the estimated P50 values differed significantly from directly measured values. The difference is highly correlated to the molar ratio of 2, 3-diphosphoglycerate to hemoglobin tetramer (2, 3-DPG ratio, [DPG]). Using this correlation, a modified Severinghaus' equation, including 2, 3-DPG molar ratio, was derived: i.e.,deltalog Po2 equals +0.48 (7.4-pH)+0.024 (T-37), +0.0013BE+0.135[DPG]-0.116 where deltalog Po2 is the shift from the standard oxygen dissociation curve, pH is plasma pH, and T and BE refer to temperature and base excess of blood, respectively. The modified equation enables one to indirectly estimate Po2 and oxygen saturation with an accuracy of plus or minus 2.5 mmHg and plus or minus 5 percent, respectively, based on blood gas parameters and 2, 3-DPG molar ratio in most clinical cases. The limitations of the equation was discussed.

MK classification for visual binary components

view Abstract Citations (82) References (4) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS MK classification for visual binary components. Edwards, T. W. Abstract MK classifications are presented for both components of 208 visual binaries, most of which appear in the Third Catalogue of Orbits of Visual Binary Stars (Finsen and Worley 1970) and which have only composite MK spectral types and visual-magnitude differences. Comparison between the results obtained and the several individually observed or previously inferred component types suggest that an accuracy of plus or minus 2 to 3 spectral subtypes may be expected for both unevolved pairs and evolved pairs; an accuracy of plus or minus 0.5 to 1.0 luminosity classes is expected for evolved pairs. Publication: The Astronomical Journal Pub Date: April 1976 DOI: 10.1086/111879 Bibcode: 1976AJ.....81..245E Keywords: Astronomical Catalogs; Binary Stars; Stellar Spectra; Classifications; Stellar Luminosity; Stellar Spectrophotometry; Tables (Data); Astronomy full text sources ADS | data products SIMBAD (252)

Minor planets and related objects. XX - Polarimetric evidence for the albedos and compositions of 94 asteroids

Polarimetric observations are presented and analyzed for a total of 94 asteroids. The data include numerical parameters describing the polarization-plane curve, the maximum depth of the negative branch, geometric albedo, and diameter. With few exceptions, the polarizations are found to be repeatable from hour to hour, night to night, and apparition to apparition at the same solar phase angle within an observational accuracy of plus or minus 0.05%. It is shown that over a range of more than a factor of 50 in diameter or a factor of 100,000 in mass, all the asteroids seem to have microscopically very rough or particulate surface textures. In terms of their polarimetric properties, the asteroids are classified as follows: 48 in the broad S class, with compositions corresponding to stony-iron meteorites or ordinary chondrites; 34 in the C class, probably corresponding to carbonaceous chondrites; three to five M asteroids with surfaces rich in free metal; two with low-opacity surfaces (class E) attributable to pure enstatite; and five of other types.

Gamma-ray spectra arising from thermal-neutron capture in elements found in soils, concretes, and structural materials

Abstract : Gamma-ray spectra arising from the capture of thermal neutrons are presented for iron, aluminum, copper, zinc, titanium, nickel, silicon, calcium, potassium, sodium, barium, chlorine, sulfur, and stainless steel. The spectral intensities in photons per 100 captures are presented as both individual lines and as sums of these lines over 0.5-MeV intervals which are intended for use in shielding calculations. The latter results have an estimated accuracy of plus or minus 15%, and include the contributions from both discrete and continuum gamma rays. Comparisons of these spectra are made with previously determined spectra, as well as with values reported in the Reactor Handbook, and considerable revision in the latter is concluded to be necessary. The present results do not go below 1 MeV, but when the relatively small contributions from energies less than 1 MeV are added to them, binding energy checks within plus or minus 5% are obtained. (Author)

A High-Performance Position Control

The position control described has been designed to achieve an accuracy of plus or minus 1 part in 4000. The control is part of the positioning mechanism for the read-write heads in a random-access magnetic-drum memory; it can position the heads to any 1 of 200 track locations, on command, in less than 100 milliseconds.

A stand camera for line-of-sight recording

The paper describes a method that has been extensively used to superpose a spot marking the position of the line-of-sight on photographs of stimulus scenes. The spot, reflected from the cornea, determines the line-of-sight with an accuracy of plus or minus 1°. Some of the useful measurements that can be made of fixation patterns are described. Two basic themes have guided the experimental applications: the relation between attention and the line of sight, and the association between peripheral and central vision. Comparisons among age groups have also demonstrated the erratic and piecemeal nature of children’s visual input. Comparisons among scenes have shown that certain areas of a picture, judged highly informative, receive most of the visual fixations. More than 20 other laboratories have also used the camera in a wide range of research on perception, cognition, and psycholinguistics.

Rocket-Noise Monitoring System

This report describes the performance of a system designed to meet the specific requirements of monitoring rocket noise in communities located miles from the test site. The pole-mounted remote stations were designed to transmit their signal via normal telephone voice channel. This was done to provide maximum economy, availability of transmission lines at many locations, and reliability through redundancy of other voice channels available from the telephone company. The microphone signal is transmitted via frequency modulated carrier over the telephone channel from the remote station to the base station. Performance of the system, including the microphone, is within the required frequency range of 0.7–350 cps, 50-dB signal-to-noise ratio, and accuracy of plus or minus 1 dB.

Cross Sections for (α,n) Reactions for Medium-Weight Nuclei

Thick target ( alpha ,n) neutron yields were measured from threshold to about 11-Mev alpha -particle energy for twenty targets ranging in A from 27 to 120. The targets of nickel, copper, and zinc were isotopically enriched. The absolute neutron yields, which were measured at approximately 100-kev energy intervals, have an accuracy of plus or minus 4%. The neutron detector was the 4 pi , flat-energy response graphite sphere detector developed by Macklin. Cross sections for the ( alpha ,n) reactions were obtained to an accuracy of plus or minus 15% by differentiation of the smooth thick-target yield curves. For those nuclei in which the ( alpha ,n) cross section is thought to account for a significant percentage of the total reaction cross section, the observed cross sections are considerably larger than those predicted by Shapiro for his larger radial parameter of 1.5 A/sup 1/2/ F. Both the shape and absolute values of the observed cross sections agree fairly well with the optical-model analysis of reaction cross sections for alpha particles by Igo. (auth)