Pin Gap Research Articles

Towing Pin Performance Optimization Strategy in SV. Triton 501

AHTS (Anchor Handling Tug Supply) is a ship specifically designed to support the operation of offshore building systems. Supply vessel or AHTS equipped with a towing pin, shark jaw. Towing winch, anchor handling winch, and tugger winch support work activities in the offshore industry (platform or riq). This research aims to analyze the factors that affect towing pin performance, what impacts can occur if the towing pin is not optimal, and the towing pin optimization strategy. The research method used is qualitative. This study uses the SWOT method (Strength, Weakness, Opportunity, and Threat). The results showed that the factors that caused the towing pin performance were not optimal due to several factors, including not optimal selenoid valve, dirty filters, mud in the towing pin gap, leaks or blocked hydraulic pipes, dirt in hydraulic oil, availability of spare parts, and human resources error. Advice that can be given is to anticipate internal and external factors that affect the performance of the towing pin in order to reduce or avoid the impacts that occur, learn how to handle components related to the towing pin directly and carry out regular and scheduled system maintenance plans for hydraulic components, the towing pin is prone to damage.

A broadband coplanar waveguide to WR4 contactless transition using interdigital‐pin electromagnetic bandgap structure

A broadband coplanar-to-rectangular waveguide transition using contactless electromagnetic bandgap (EBG) structure in the form of interdigital-pin bed of nails has been introduced in this paper. The electromagnetic (EM) wave propagates from the CPW, and then radiates from the probe into the WR4. The rectangular patch is adopted as the probe to accomplish a broadband performance without an impedance transformer. At the same time, CPW to rectangular waveguide (RW) directly transition without EBG unit also has been designed and the simulated results show the transmission performance has low tolerance to air gap. The interdigital-pin EBG structure is added to the machining splitter of the RW which is no need for strict electrical contact and is not harmful for transition performance. The greatest advantage of the interdigital-pin lattice has a significant pin gap increase and is easy to fabricate for millimeter-wave (mm-Wave) and terahertz (THz) applications. The back-to-back prototype is designed, fabricated and measured. The measured |S11| is better than −10 dB over 170–260 GHz, covering a bandwidth of 41.8%.

Separation of Multi-Material Polymer Combinations Produced by Joining Using Pin-like Structures

In industrial applications, multi-material joints are becoming increasingly important to achieve a sustainable and resource-saving production. Not only high mechanical properties during the component use have to be given, but also possibilities to separate the joint after end of life are crucial. The recycling and re-use of the materials plays an increasing role in the process chain. Conventional multi-material joints can be separated by cutting out the joining zone, solvents, or thermal degradation. However, these methods result in a loss of material, damage to the base material, or high energy consumption. Therefore, novel joining methods are desirable, such as the joining using pin-like structures. The potential of this novel method for joining adhesion incompatible materials has been demonstrated in previous studies. This paper studies the separability of these connections. Therefore, joints between polyamide 66 (PA66) and polypropylene (PP) as well as PA66 and polymethylmethacrylate (PMMA) are investigated by means of thermal separation and shredding with subsequent sorting using the density difference of the materials. The separated components were investigated by analytical methods (including dissolution tests, viscosity number analysis, and Fourier-transform infrared spectroscopy) with respect to varietal purity and possible degradation effects. It could be shown that shredding allows a complete separation of the multi-material joint into its individual components without material residues or material loss. For thermal separation, material residues of PP or PMMA could be detected in the pin gaps of the PA66. For both separation methods, an influence on the base materials due to degradation effects could be excluded. It can be stated that joining using pin-like structures in vibration welding technology offers a sustainable production of multi-material joints with high recyclability.

Pin-Gap Correction of Coaxial Calibration Standards for TRL or LRL Calibration

In this paper, a novel method is proposed by which to correct the pin gaps of coaxial calibration standards for Thru-Reflect-Line (TRL) or Line-Reflect-Line (LRL) calibration. This method is a post-process in which the pin-gap correction is applied to the measured S-parameters of the device under test (DUT) after TRL or LRL calibration. It is based on the perturbation equations derived from the sensitivity-coefficient approach. These equations enable us to obtain the correction quantity of the DUT-S-parameter due to the pin gaps. We verify the proposed method by simulation for a 2.4 mm coaxial line, and the result shows that the pin-gap correction works successfully. Because the method is based on the perturbation equations, the smaller the pin gap, the better the correction results. Nevertheless, we can achieve sufficient correction results within the range of the pin-gap to at least 10 times the nominal value. In addition, the proposed pin-gap correction can play the role of impedance renormalization, even though the two LRL calibration lines have different characteristic impedance. Finally, we demonstrate the correction method for a 2.4 mm coaxial LRL calibration kit through measurement.

A Wideband High-power Low-loss Power Divider Using Half-height Pin Gap Waveguide Technology

In this paper, for the first time, a wideband low -loss high-power equally splitting power divider based on the new half-height pin form is introduced with bandwidth from 10 to 13.5 GHz centered at 11.75 GHz. Also, for the first time, a wideband transition from coaxial line to half-height pin gap waveguide with no need of any matching sections with excellent results at the band of (10:20 GHz) was achieved. The proposed transition shows excellent return loss which is lower than 30 dB (measured) at the transition bandwidth center frequency which is (15 GHz) with 0.2 dB (measured) insertion loss and return loss lower than 20 dB (measured) with 0.55 dB insertion loss at the rest of the bandwidth. The proposed transition and power divider designs were validated using circuit and 3D full-wave simulations and confirmed using experimental measurements with all agreements. The power divider has simple manufacturing due to the new pin form; hence, it is suitable for low-cost mass production of high-power mm-wave power dividers.

An unequal power divider based on ridge gap waveguide with an inserted conductor plate

AbstractA novel unequal power divider based on ridge gap waveguide is proposed and investigated in this paper. The half‐height pin gap waveguide structure is applied to acquire the required stopband. The whole divider can be divided into three parts. The first part is the core of the divider which is a gap waveguide transmission line with a thin inserted conductor plate (ICP). The ICP is printed on a thin substrate for the mechanical feasibility and stability. The position of the ICP can be changed to adjust the power division ratio (PDR). The ICP separates the divider into two different layers. Then, the second and third parts are transitions from top layer and bottom layer to normal gap waveguide transmission lines. Two power dividers with different PDRs of 1:2 and 1:4 working at 28 GHz are designed and manufactured to verify this topology.

Gap Waveguide With Interdigital-Pin Bed of Nails for High-Frequency Applications

A new kind of contactless electromagnetic bandgap (EBG) structure in the form of interdigital-pin bed of nails is introduced for the first time in this paper. It consists of two metal plates with interdigital-pin bed of nails face to face with each other, where each pin is surrounded by four pins on the other plate. The working mechanism of the interdigital-pin contactless EBG structure is suppressing the modes supported by the parallel plate waveguide (PPW) by loading interdigital pins inside the PPW. The advantage of the interdigital-pin lattice is there is a significant pin gap increase. This lattice makes the minimum pin gap that could be processed by the machining center, after assembling, reduced from the diameter of the milling clutter to its radius. It provides a way to process EBG structures at higher frequency band with the same milling cutter. The cases the pins allocated between the two plates in a random manner are also studied. Compared to its traditional counterpart, the stopband is stable with a small variation. A W-band groove gap waveguide (GGW) prototype with interdigital-pins and a Ka-band GGW with randomly allocated pins are designed, manufactured, and tested. The measured results agree well with the simulation.

Specificity of characteristic marks on cartridge cases from 3070 consecutive firings of a Chinese Norinco QSZ-92 9 mm Pistol

The specificity of marks was evaluated by differences between marks left by the same firearm (within variability) and differences between marks left by different firearms (between variability). The within variability and between variability of firing pin impressions and breech face marks on cartridge cases from over 3070 consecutive firings of a Chinese Norinco QSZ-92 9 mm pistol were investigated based on the automated ballistic identification system Evofinder®. The first 20 cartridge cases and one random specimen out of every set of 10 consecutive cartridge cases of the remaining 3050 cases were entered into the Evofinder® system. Thus, 325 cartridges fired from the same pistol were used to estimate the within variability. Then, 88 cartridges fired from 88 different pistols of the same model (one cartridge each) were used to estimate the between variability. This study established a database containing 413 cartridges. We used the 325 cartridges fired from the same pistol as a correlation baseline in the database. Both firing pin and breech scores and gaps between these scores were used to analyze the variability. In the score evaluation process, a likelihood ratio system was used to evaluate the likelihood ratio performance. The Evofinder® system correctly discriminated the matches, and the likelihood ratios provided strong support for the true state of the hypothesis. In addition, we found that the score gap was usually greater than the other score differences by more than 1000% in firing pin list and 100% in the breech list. Further analysis of the score and gap can help examiners use the Evofinder® system more efficiently.

Reconfigurable Microfluidic Channel with Pin-discretized Sidewalls

Microfluidic components need to have various shapes to realize different key microfluidic functions such as mixing, separation, particle trapping, or reactions. A microfluidic channel that deforms even after fabrication while retaining the channel shape enables high spatiotemporal reconfigurability. This reconfigurability is required in such key microfluidic functions that are difficult to achieve in existing "reconfigurable" or "integrated" microfluidic systems. We describe a method for the fabrication of a microfluidic channel with a deformable sidewall consisting of a laterally aligned array of the ends of rectangular pins. Actuating the pins in their longitudinal directions changes the pins' end positions, and thus, the shape of discretized channel sidewalls.Pin gaps can cause unwanted leakage or adhesion to adjacent pins caused by meniscus forces. To close the pin gaps, we have introduced hydrocarbon-fluoropolymer suspension-based gap filler accompanied by an elastomeric barrier. This reconfigurable microfluidic device can generate strong temporal in-channel displacement flow, or can stop the flow in any region of the channel. This feature will facilitate, on demand, the handling of cells, viscous liquids, gas bubbles, and non-fluids, even if their existence or behavior is unknown at the time of fabrication.

Reconfigurable Microfluidic Channel with Pin-discretized Sidewalls.

Microfluidic components need to have various shapes to realize different key microfluidic functions such as mixing, separation, particle trapping, or reactions. A microfluidic channel that deforms even after fabrication while retaining the channel shape enables high spatiotemporal reconfigurability. This reconfigurability is required in such key microfluidic functions that are difficult to achieve in existing "reconfigurable" or "integrated" microfluidic systems. We describe a method for the fabrication of a microfluidic channel with a deformable sidewall consisting of a laterally aligned array of the ends of rectangular pins. Actuating the pins in their longitudinal directions changes the pins' end positions, and thus, the shape of discretized channel sidewalls.Pin gaps can cause unwanted leakage or adhesion to adjacent pins caused by meniscus forces. To close the pin gaps, we have introduced hydrocarbon-fluoropolymer suspension-based gap filler accompanied by an elastomeric barrier. This reconfigurable microfluidic device can generate strong temporal in-channel displacement flow, or can stop the flow in any region of the channel. This feature will facilitate, on demand, the handling of cells, viscous liquids, gas bubbles, and non-fluids, even if their existence or behavior is unknown at the time of fabrication.

Subchannel analysis with turbulent mixing rate of supercritical pressure fluid

The subchannel analysis with turbulent mixing rate law of supercritical pressure fluid (SPF) is carried out for supercritical-pressurized light water cooled and moderated reactor (Super LWR). It is different from the turbulent mixing rate law of pressurized water reactor (PWR), which is widely adopted in Super LWR subchannel analysis study, the density difference between adjacent subchannels is taken into account for turbulent mixing rate law of SPF. MCSTs are evaluated on three kinds of fuel assemblies with different pin power distribution patterns, gap spacings and mass flow rates. Compared with that calculated by employing turbulent mixing rate law of PWR, the increase in MCST is smaller even when peaking factor is large and gap spacing is uneven. The sensitivities of MCST on non-uniformity of the subchannel area and power peaking are reduced.

A new dynamic tactile display for reconfigurable braille: implementation and tests.

Different tactile interfaces have been proposed to represent either text (braille) or, in a few cases, tactile large-area screens as replacements for visual displays. None of the implementations so far can be customized to match users' preferences, perceptual differences and skills. Optimal choices in these respects are still debated; we approach a solution by designing a flexible device allowing the user to choose key parameters of tactile transduction. We present here a new dynamic tactile display, a 8 × 8 matrix of plastic pins based on well-established and reliable piezoelectric technology to offer high resolution (pin gap 0.7mm) as well as tunable strength of the pins displacement, and refresh rate up to 50s−1. It can reproduce arbitrary patterns, allowing it to serve the dual purpose of providing, depending on contingent user needs, tactile rendering of non-character information, and reconfigurable braille rendering. Given the relevance of the latter functionality for the expected average user, we considered testing braille encoding by volunteers a benchmark of primary importance. Tests were performed to assess the acceptance and usability with minimal training, and to check whether the offered flexibility was indeed perceived by the subject as an added value compared to conventional braille devices. Different mappings between braille dots and actual tactile pins were implemented to match user needs. Performances of eight experienced braille readers were defined as the fraction of correct identifications of rendered content. Different information contents were tested (median performance on random strings, words, sentences identification was about 75%, 85%, 98%, respectively, with a significant increase, p < 0.01), obtaining statistically significant improvements in performance during the tests (p < 0.05). Experimental results, together with qualitative ratings provided by the subjects, show a good acceptance and the effectiveness of the proposed solution.

Ac breakdown in near-atmospheric pressure noble gases: I. Experiment

Ac-driven breakdown processes have been explored much less than the pulsed or dc breakdown, even though they have possible applications in industry. This paper focuses on the frequency range between 60 kHz and 1 MHz, at a pin–pin electrode geometry and gap lengths of 4 or 7 mm. The breakdown process was examined in argon and xenon at 0.3 and 0.7 bar. We used electrical and optical measurements to characterize the breakdown process, to observe the influence of frequency change and the effect of ignition enhancers—UV irradiation and radioactive material.

Breeding Capability and Void Reactivity Analysis of Heavy-Water-Cooled Thorium Reactor

The fuel breeding and void reactivity coefficient of thorium reactors have been investigated using heavy water as coolant for several parametric surveys on moderator-to-fuel ratio (MFR) and burnup. The equilibrium fuel cycle burnup calculation has been performed, which is coupled with the cell calculation for this evaluation. The η of 233U shows its superiority over other fissile nuclides in the surveyed MFR ranges and always stays higher than 2.1, which indicates that the reactor has a breeding condition for a wide range of MFR. A breeding condition with a burnup comparable to that of a standard PWR or higher can be achieved by adopting a larger pin gap (1–6 mm), and a pin gap of about 2mm can be used to achieve a breeding ratio (BR) of 1.1. A feasible design region of the reactors, which fulfills the breeding condition and negative void reactivity coefficient, has been found. A heavy-water-cooled PWR-type Th-233U fuel reactor can be designed as a breeder reactor with negative void coefficient.

The chemical constitution of the fuel-clad gap in oxide fuel pins for nuclear reactors

An assessment of the chemical equilibria which can occur in the fuel-clad gap of irradiated pins for water-cooled thermal reactors and liquid-sodium-cooled fast breeder reactors is presented. An understanding of such reactions is essential to the elucidation of mechanisms of cladding failure due to fission product elements. Particular attention is given to the variation of the chemical constitution of phases containing the fission product elements caesium, iodine and tellurium. The perturbation by irradiation of the thermal equilibrium concentrations of the gaseous species of these fission product elements has also been assessed in this paper.

Statistical evaluation of pin gaps in fuel clusters for fugen (II)

Fuel pin gaps of Fugen fuel assemblies deviate statistically from their nominal value due to manufacturing and assembling tolerances which influence the thermal and hydraulic characteristics of the reactor core. For assurance of the minimum fuel pin gap, an analytical method of evaluating the reliability of spacer gauge tests applied to selected fuel pin gaps arrayed within a Fugen fuel assembly is discussed where a computer program STGAP is utilized. Correlations among the thickness of a spacer gauge, the reliability of the test and the rate of rejecting fuel assemblies whose pin gaps all satisfy the minimum design criterion are discussed in connection with the optimum gauge thickness for a given realiability level of the test. Sample calculation shows that fuel subassemblies installed in a Fugen reactor core have the overall reliability level of 99.9954% at the beginning of fuel life.

Probabilistic distributions of pin gaps within a wire-spaced fuel subassembly and sensitivities of the related uncertainties to pin gap

Probabilistic fuel pin gap distributions within a wire-spaced fuel subassembly and sensitivities of the related uncertainties to fuel pin gaps are discussed. The analyses consist mainly of expressing a local fuel pin gap in terms of sensitivity functions of the related uncertainties and calculating the corresponding probabilistic distribution through taking all the possible combinations of the distribution of uncertainties. The results of illustrative calculations show that with the reliability level of 0.9987, the maximum deviation of the pin gap at the cladding hot spot of a center fuel subassembly is 8.05% from its nominal value and the corresponding probabilistic pin gap distribution is shifted to the narrower side due to the external confinement of a pin bundle with a wrapper tube.

Statistical evaluation of pin gaps in fuel clusters for fugen

The computer program STGAP has been developed to estimate pin gaps in a fuel assembly for FUGEN. The program optionally computes the probable distribution of the pin gap between any adjacent pair of fuel pins, either at a desired location in an assembly or longitudinally averaged over the total effective length of a pin, based on the measured manufacturing and assembling tolerances in geometrical dimensions and mechanical properties of all the independent elements composing a fuel assembly. It also correlates the computed fuel gap distribution with the minimum critical heat flux ratio in the corresponding local subchannel. Sample calculations were performed for the probable distributions of the pin gaps between pairs of adjacent fuel pins in the outermost layer of a FUGEN fuel assembly using the program and satisfactory agreement was obtained with the corresponding measured distributions.