On the effect of wear on small mesh wire sieves

1923 ◽  
Vol 13 (4) ◽  
pp. 467-482 ◽  
Author(s):  
Bernard A. Keen ◽  
William B. Haines

A series of measurements of wire diameter, length of side, and area of holes, has been made on new and used sieves, all of which were originally of the “100 mesh” size, i.e. the square holes were supposed to be ·01″ in length of side and the wire to be ·01″ in diameter. The measurements have been expressed as frequency curves.In the case of unused sieves woven to the I.M.M. specification, the sieve on the whole compared well with the specification, but in used sieves the variations were much greater. The divergence from specification in the new and old sieves is shown by Tables I and II respectively.In one sieve (No. 2) the holes elongated more in one direction than the other. In fact in one direction the alteration which has taken place is a contraction rather than a stretch. This effect was probably connected with the manner in which the sieve was attached to its metal framework, and also to difference in tempering of the wires and the tension in weaving.A number of the frequency curves showed double peaks, and the actual observations showed that there was a systematic distribution of values corresponding to these two peaks. It is probable that some of the guides in one of the combs through which the warp wires are led during the weaving were displaced sideways, thus giving alternate strands of wire and narrow holes. This was particularly the case in the single weave.

1992 ◽  
Vol 49 (10) ◽  
pp. 2104-2117 ◽  
Author(s):  
Petri Suuronen ◽  
Russell B. Millar

A twin codend trawl was fished in the northern Baltic to study the size selectivity of square mesh and diamond mesh codends of 36-mm nominal mesh size. For each codend, 15 hauls were completed with a small mesh (20 mm) codend deployed on the other side of the trawl. The relative size of the catches in the two sides of the trawl varied considerably from haul to haul (the separator section was not operating properly) and selection curves were estimated from each individual haul using a method that incorporated the differences in catching efficiency of the two sides. The length of 50% retention decreased with increased catch for both the diamond and square mesh codends, although in neither case was this relationship statistically significant. Selection curves fitted to the combined haul data were asymmetric. The square mesh codend retained significantly less small herring than the diamond mesh codend, and for larger herring the two codends had similar selectivity. In both codends, most escapes occurred at the front of the catch bulge, from the upper side of the codend. At high catch rates, mesh blockage was observed for several metres ahead of the catch bulge during the later part of the tow.


1991 ◽  
Vol 39 (1) ◽  
pp. 61-69 ◽  
Author(s):  
Catarina Ramis Nogueira ◽  
Sérgio dos Reis Oliveira Jr

This work is based on the analysis of 99 zooplankton samples collected during the Oceanographic Expedition "ESPÍRITO SANTO I", held along the east coast of Brazil, between Cabo Frio and Abrolhos Archipelago, an area characterized by the occurrence of coastal upwelling, from July to September 1984. Zooplankton was collected with vertical plankton net hauls of 250 µm mesh size in the upper 200 meters layer. A total of twenty one species of Siphonophora was observed, two of which were identified as being physonect and the other as calycophorans. Specific diversity close to the shore and at the neighborhood of the Vitória-Trindade Bank System, showed smaller values, in comparison with those in the oceanic regions. Factorial analysis was used in order to access the changes observed in the population of the eleven most abundant species. The first two principal axes represented the influence of the nearshore - offshore gradient and the role of trophic interaction, accounted for 60% of the total variance of the data.


1990 ◽  
Vol 36 (11) ◽  
pp. 1906-1910 ◽  
Author(s):  
J Osada ◽  
T Gea ◽  
C Sanz ◽  
I Millan ◽  
J Botella

Abstract A group of substances of molecular masses between 300 and 1500 Da have been found to be toxic metabolites in patients with uremia. We determined the concentration in serum of these molecules in the following groups of patients: two hemodialyzed groups (one with cuprophane and the other with polyacrylonitrile dialyzers), one group treated with continuous ambulatory peritoneal dialysis, one group of nondialyzed azotemic patients, and one control group of healthy persons. Ultrafiltrates of the subjects' sera were fractionated on Sephadex G-15 followed by ion-exchange chromatography. Eluates were monitored by absorbance at 254 and 206 nm. Partially characterized peaks P1 and P2, obtained by gel filtration, correlated with the concentration of creatinine in serum; their concentrations were significantly (P less than 0.01) larger in hemodialyzed groups than in peritoneal dialyzed or in nondialyzed azotemic patients. After ion-exchange chromatography, two peaks (P'5 and P'6) correlated with serum creatinine and also were larger in hemodialyzed patients than in the other groups. Apparently, adequate discrimination is obtained by gel-filtration analysis and further analysis by ion-exchange chromatography does not provide additional information in most of the affected patients.


2017 ◽  
Vol 164 (14) ◽  
pp. E560-E564 ◽  
Author(s):  
S. Seghir Mechaour ◽  
A. Derardja ◽  
K. Oulmi ◽  
M. J. Deen

2011 ◽  
Vol 1 (7) ◽  
pp. 33
Author(s):  
P.J. Wemelsfelder

In coastal engineering we often have to face the problem of high stormfloods. Especially if the land near the coast is flat and low, if it is densely populated or if high economic values have to be protected. In all these oases, where life and economic values are at stake, a design flood has to be established as a basis for the construction of the works of protection. Obviously the height of the design flood will be dependent on two factors. On one hand it depends on the characteristics of the sea, on its probable and possible heights. On the other hand it depends on the values of human and economic nature, threatened by the sea. So the design flood may be regarded as a balance between the threatening force of the sea and the values at stake. In this paper we will investigate the nature of this balance. This will lead us to a close examination of the frequency curves of stormfloods, to a discussion of the question: What is a reasonable risk and to a discussion of the question: What is the space of time we have to take into account.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Guidobeth Sáez ◽  
Pablo Díaz ◽  
Eduardo Cisternas ◽  
Eugenio E. Vogel ◽  
Juan Escrig

AbstractA long piece of magnetic material shaped as a central cylindrical wire (diameter $$d=50$$ d = 50 nm) with two wider coaxial cylindrical portions (diameter $$D=90$$ D = 90 nm and thickness $$t=100$$ t = 100 nm) defines a bimodulated nanowire. Micromagnetism is invoked to study the equilibrium energy of the system under the variations of the positions of the modulations along the wire. The system can be thought of as composed of five independent elements (3 segments and 2 modulations) leading to $$2^5=32$$ 2 5 = 32 possible different magnetic configurations, which will be later simplified to 4. We investigate the stability of the configurations depending on the positions of the modulations. The relative chirality of the modulations has negligible contributions to the energy and they have no effect on the stability of the stored configuration. However, the modulations are extremely important in pinning the domain walls that lead to consider each segment as independent from the rest. A phase diagram reporting the stability of the inscribed magnetic configurations is produced. The stability of the system was then tested under the action of external magnetic fields and it was found that more than 50 mT are necessary to alter the inscribed information. The main purpose of this paper is to find whether a prototype like this can be complemented to be used as a magnetic key or to store information in the form of firmware. Present results indicate that both possibilities are feasible.


Author(s):  
Paul Motzki ◽  
Tom Gorges ◽  
Thomas Würtz ◽  
Stefan Seelecke

The thermal shape memory effect describes the ability of a deformed material to return to its original shape when heated. This effect is found in shape memory alloys (SMAs) such as nickel-titanium (NiTi). SMA actuator wire is known for its high energy density and allows for the construction of compact systems. An additional advantage is the so-called “self-sensing” effect, which can be used for sensor tasks within an actuator-sensor-system. In most applications, a current is used to heat the SMA wires through joule heating. Usually a current between zero and four ampere is recommended by the SMA wire manufacturers depending on the wire diameter. Therefore, supply voltage is adjusted to the SMA wire’s electrical resistance to reach the recommended current. The focus of this work is to use supply voltages of magnitudes higher than the recommended supply voltages on SMA actuator wires. This actuation method has the advantage of being able to use industry standard voltage supplies for SMA actuators. Additionally, depending on the application, faster actuation and higher strokes can be achieved. The high voltage results in a high current in the SMA wire. To prevent the wire from being destroyed by the high current, short pulses in the micro- and millisecond range are used. As part of the presented work, a test setup has been constructed to examine the effects of the crucial parameters such as supply voltage amplitude, pulse duration, wire diameter and wire pre-tension. The monitored parameters in this setup are the wire displacement, wire current and force generated by the SMA wire. All sensors in this setup and their timing is validated through several experiments. Additionally, a highspeed optical camera system is used to record qualitative videos of the SMA wire’s behavior under there extreme conditions. This optical feedback is necessary to fully understand and interpret the measured force and displacement signals.


2010 ◽  
Vol 2010 (1) ◽  
pp. 000474-000478 ◽  
Author(s):  
David J Rasmussen ◽  
Rodney Thompson

Whether the need is due to poorly bondable materials, non-flat bonding surfaces, odd packaging situations, or just the need for high reliability; the integrity of a wire bond interconnect can usually be greatly improved through the proper use of Auxiliary Wires. Auxiliary Wires are defined as Security Wires, Security Bumps, or Stand-Off Stitch (aka Stitch on Bump). The old stand-by Security Wire has been an asset for several decades, however, this is being replaced by Security Bumps which require a smaller second bond termination area. Further, Stand-Off Stitch (SOS) has many more applications and also has many side benefits that could be incorporated into a circuit design for better wire strength properties, fewer interconnects (die to die bonding), and lower loops. Stand-Off Stitch bonding involves the placement of a ball bump at one end of the wire interconnect, then placing a wire with another ball at the other end of the interconnect and stitching off the wire on the previous placed ball bump. This results in a near homogeneous stitch bond interconnect to the bump with an inherent improvement in stitch bond pull strength. Another use for SOS is Reverse Bonding (Stitch bond on bump on die bond pad) often resulting in a lower loop profile than standard forward wire loop and the loop is stronger because the wire hasn't been work annealed above the ball (in the Heat Affected Zone). A major impediment to the implementation of SOS is the retraining of visual inspectors and the approval of quality departments.


Endoscopy ◽  
2017 ◽  
Vol 49 (10) ◽  
pp. 983-988 ◽  
Author(s):  
Yousuke Nakai ◽  
Hiroyuki Isayama ◽  
Saburo Matsubara ◽  
Hirofumi Kogure ◽  
Suguru Mizuno ◽  
...  

Abstract Background and study aim Endoscopic ultrasound-guided rendezvous (EUS-RV) is increasingly reported as a treatment option after failed endoscopic retrograde cholangiopancreatography. We developed a novel “hitch-and-ride” catheter for biliary cannulation to reduce the risk of guidewire loss during EUS-RV. Patients and methods We retrospectively evaluated safety and technical success of EUS-RV between June 2011 and May 2016. Biliary cannulation during EUS-RV using three methods – over-the-wire, along-the-wire, and hitch-and-ride – were compared. Results A total of 30 EUS-RVs were attempted and the technical success rate was 93.3 %, with two failures (one bile duct puncture and one guidewire insertion). After 28 cases of successful guidewire passage, cannulation was attempted by the over-the-wire (n = 13), along-the-wire (n = 4) or hitch-and-ride (n = 11) method. Only the hitch-and-ride method achieved biliary cannulation without guidewire loss or conversion to the other methods. Time to cannulation was shorter with the hitch-and-ride method (4 minutes) than with over-the-wire and along-the-wire methods (9 and 13 minutes, respectively). The adverse event rate of EUS-RV was 23.3 %. Conclusion A novel hitch-and-ride catheter was feasible for biliary cannulation after EUS-RV.


2019 ◽  
Vol 627 ◽  
pp. L3 ◽  
Author(s):  
Daniel Maschmann ◽  
Anne-Laure Melchior

We present a study of 58 double-peaked emission line galaxies for which one of the components is suppressed in [OIII]λ5008 or is significantly weaker than the other one. Accordingly, the two components are classified differently in the BPT diagram. We show that the strong [OIII] component coincides with the stellar velocity and the suppressed component is off-centred in 66% of the galaxies, while in 12% of them it is the opposite. The analysis of their morphology reveals that about half of the sample is composed of S0, and the rest is composed of mergers and late-type galaxies in equal measure. We discuss the hypothesis that these characteristics exclude rotating discs and suggest different stages of merging. It is possible that the number of mergers is underestimated if the double nuclei are not resolved. Tidal features are detected in the outskirts of some S0 galaxies. This high fraction of S0 is surprising, as in addition most of the galaxies are isolated and the others are in small groups. All these galaxies that host an AGN component are massive, lie on the star forming sequence, and exhibit an enhanced star formation at their centre. While we cannot exclude outflows, these galaxies exhibit spectra that do not correspond to usual outflow observations characterised by high gas velocities, and the standard deviations of the two peaks are comparable. In parallel, these characteristics are compatible with ultimate stages of galaxy merging, where the two nuclei are either too close to be detected, or dynamical disturbances might be present in post-mergers like massive S0 galaxies.


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