Cut Wire Research Articles

The Influence of Shot Peening Media on Surface Properties and Fatigue Behaviour of Aluminium Alloy 6082 T6

Shot peening is generally used to improve the fatigue performance of mechanical components. However, identifying the geometrical and mechanical characteristics of the shots that improve fatigue strength is still a challenging task, as there are many variables involved in the shot peening process. The present work addresses the effect of different shot media on the fatigue behaviour of an aluminium alloy 6082 T6. Four different shot types were used: silica microspheres, alumina shots, aluminium cut wire and zinc cut wire. Axial fatigue tests were carried out to obtain the Wöhler curves corresponding to each shot peening treatment. The surface properties of the shot-peened specimens, such as grain size, hardness, residual stress and roughness were measured to determine their effect on the fatigue results. The fatigue results revealed that silica and zinc shots increased significantly the fatigue life of the alloy, whereas alumina and aluminium shots reduced its fatigue strength. Almen intensities have shown to correlate well with grain refinement and strain hardening. However, better fatigue results were obtained with the shots that generated higher surface compressive residual stresses. It is believed that small and smooth shots are preferable to sharp and irregular ones, regardless of the Almen intensity or surface hardness attained with the latter.

Asymmetric transmission for linearly polarized terahertz waves without polarization conversion

In this study, a novel metamaterial (MM) architecture is presented, which comprises cut wires and split-ring resonators (SRRs) and demonstrates asymmetric transmission characteristics. Unlike previously reported multi-layer chiral structures, spatial asymmetry is introduced by aligning the cut wires and SRRs with the propagation direction of electromagnetic waves. This innovative alignment effectively disrupts time-reversal symmetry, enabling asymmetric transmission. A thorough analysis of the electromagnetic field distribution and surface current patterns offers insights into the fundamental mechanisms underlying this asymmetric transmission. Notably, the ability of this MM design to maintain the polarization state of transmitted waves positions it as a promising candidate for terahertz systems applications.

Design of electrical cabinet wire cutting machine based on STM32

Abstract The wire in the electric cabinet is one of the keys to ensuring the normal operation of the electric cabinet. In order to improve the production efficiency of wire cutting, this project designed a wire-cutting machine for an electrical cabinet, which could recognize the CSV table file of the electrical cabinet wiring list on a U disk and cut wires of different lengths and quantities according to the order in the file. The main control chip of the device uses STM32 single chip microcomputer (STM32F103C8T6) and CH376S module to realize the function of reading CSV file on U disk through serial communication. In terms of control, the device adopts a proportional-integral-differential (PID) control algorithm to achieve accurate control of the JGB37-520 gear motor and TD-8120MG steering gear and then realizes wire feeding, wire stripping, cutting, and other functions. The experimental results show that the average relative error of length is about 0.5%, and the error is within a reasonable range.

Terahertz sensor based on plasmon-induced transparency in a carbon nanotube metamaterial

In this paper, the plasmon-induced transparency (PIT) effect based on a carbon nanotube (CNT) resonator structure is achieved. An array of two split ring resonators (SRRs) and a cut wire (CW) resonator are utilized to form the proposed metamaterial. A PIT transparency window is achieved under a TM polarization terahertz light. Results show that the PIT effect is originated from the near-field coupled of the bright mode and dark mode. A coupled harmonic oscillator model is used to describe the near-field coupling between the bright mode and subradiant mode, and the results agree well with the FDTD simulation. The effect of geometrical sizes, like structure period, the radius and the splitting degree of the split ring resonator, the length of the cut wire resonator, and the coupling distance on the PIT window is analyzed in detail. Besides, the sensing and slow light performance of the proposed CNT metamaterial are studied, a maximum sensitivity of 0.74 THz RIU, and a time delay of 0.54 ps are obtained. Therefore, the proposed CNT-based device can be applied to the PIT effect, near-infrared modulators, slow light devices, sensors, and other fields.

Fluidized bed finishing of additively manufactured objects: The influence of operating parameters

This study investigates the potential of Fluidized Bed Finishing (FBF) of square flat AlSi10Mg specimens manufactured via Laser-Powder Bed Fusion (L-PBF) additive manufacturing technology. Two FBF operational modes were experimentally investigated: I) with stationary specimens; II) with specimens under controlled rotational motion. Four different abrasive materials have been tested, quartz sand, corundum, irregular steel and cut wire steel particles, characterized by different hardness, density and shape. The effect of the abrasive material, processing time and specimen tilt angle was investigated. Results showed moderate smoothing under stationary specimen configuration, while good finishing for rotation-assisted tests, maximum reduction of the surface roughness of 12% and 67%, respectively. Steel particles were the most effective bed material, with particle density overtaking hardness as key particle property. The optimal tilt angle was the one that maximized sliding and shear. Altogether, surface finishing is driven by surface shear forces dominated by inertial stresses in particulate phase.

Dielectric‐Based Electromagnetically Induced Transparency Metamaterial in the Microwave Band

AbstractAn electromagnetically induced transparency metamaterial (EITM) based on dielectric resonators is presented in this paper, which consists of a cut wire (CW) and ten dielectric columns. Destructive interference between the CW, which is a branch of the microstrip line, and the dielectric resonators causes the EIT phenomenon. The simulation results show that the dielectric‐based EITM designed can obtain a transmission peak of 0.938 at 2.17 GHz, and the two‐oscillator model is utilized to verify the effectiveness of the structure. In addition, samples of the dielectric‐based EITM are also fabricated and the effectiveness of the metamaterial is experimentally verified. The proposed metamaterial has several advantages, including high efficiency, low loss, a simple structure, and ease of manufacture, which has good prospects for application in the fields of electromagnetic switches, sensors, and nonlinear metamaterials.

Actively tunable plasmon-induced transparency in terahertz based on Dirac semimetal metamaterials.

We numerically investigate a tunable plasmon-induced transparency based on bulk Dirac semimetal (BDS) metamaterial in the terahertz band. In the unit cell, the prominent transparent peak appears to be due to the interference between the cut wires (CWs) and split-ring resonators (SRRs). An active modulation via near-field coupling is obtained by varying the Fermi level of the BDS. Introducing photoactive silicon, it will be found that once the intensity of the pump light is adjusted, a tunable transparent peak will appear. Furthermore, by shifting the coupling distance between CWs and SRRs, the depth of the transparent peak will change accordingly. Finally, we place the structure in environments with different refractive indices, which will exhibit excellent sensitivity and facilitate the application of biochemical sensors. This simple and easy-to-fabricate metamaterial structure will have excellent potential applications in modulation, filters, and detection.

Coupling-Assisted Quasi-Bound States in the Continuum in Heterogeneous Metasurfaces

In this paper, we present a Bound states in the continuum (BIC) metamaterial in heterogeneous structures based on the coupled mode theory. We find the more general physical parameters to represent BIC, which are the resonant frequencies and corresponding phases of metamaterial structures. Therefore, BIC metamaterial comes from the equal value of the resonant frequencies and phases of metamaterial structures which are not only for homogeneous structures. Meanwhile, if one of the metamaterial structure's resonant frequency and phase vary by varying geometry, we can obtain the quasi-BIC instead of the broken symmetry of homogeneous structures. In this paper, we provide the BIC and quasi-BIC with one example of two heterogeneous structures which are cut wire (CW) and Split-Ring Resonator (SRR) and it widely extends the metamaterial BIC beyond common sense. Furthermore, we demonstrate the simulation results and experimental results to proof our idea.

Electromagnetically Induced Transparency Analog of Asymmetric Perovskite Metamaterial in the THz Spectral Region

The analogy of electromagnetically induced transparency (EIT) in perovskite metamaterials is characterized by the numerical simulations in finite-difference time-domain (FDTD). The perovskite metamaterials consist of two cut wire resonators (CWRs) and a disk resonator (DR) on a polyimide substrate. The analysis revealed the characteristic dynamics of the electromagnetic field, the near-field couplings of CWRs and DR, and the EIT-like spectral features of perovskite metamaterials as functions of the asymmetry parameter and polarization direction. The strong coupling and destructive interference of bright and bright–dark transitions in perovskite metamaterials displayed EIT-like transparency at 653.5 GHz with a high Q-factor of approximately 1470, a sensitivity of 531 GHz/RIU and a figure of merit of around 780. In addition, perovskite metamaterials exhibited slow light with a group delay of about 106 ps and a group index of approximately 3100. These results may provide an important perspective for understanding the coupling mechanism and applications of perovskite materials in slow-light devices, THz sensors, and tunable switching in THz spectral region.

Analog of electromagnetically induced transparency based on asymmetric nickel-ferrite metamaterials in THz regime

The electromagnetically induced transparency-like characteristics of asymmetric nickel-ferrite metamaterials through near-field coupling are investigated in the terahertz regime. The nickel-ferrite metamaterial consists of a cut wire resonator on the front side and a disk resonator at the back of the quartz substrate. The analog of electromagnetically induced transparency is characterized by employing a finite difference frequency domain technique. By designing the nickel-ferrite metamaterial to overcome Snoek’s limitation of ferrite materials in the THz spectral region, electromagnetically induced transparency-like spectral features with a high quality factor and slow-light effect are achieved. These results may provide an important way to understand the coupling mechanism and ferrite material application in slow-light devices, THz sensors, and tunable switching in THz frequency bands.

In Vitro Effect Of Fluoride Prophylactic Agents On Titanium Molybdenum Alloy And Stainless Steel Orthodontic Wires – Scanning Electron Microscope Study

Background: TMA (Titanium-molybdenum) and SS (Stainless steel) wires are most commonly availed for orthodontic treatment. Meanwhile, patients are encouraged to employ mouthwashes containing fluoride to maintain their oral hygiene. Objective: To assess the effect of different fluoride prophylactic agents on TMA and SS wires for specific time periods namely 10 minutes, 1 hour, 24 hours. Material and Methods: The sample comprised TMA and SS wires immersed in agents such as Artificial saliva (pH = 6.8), Acidulated phosphate fluoride gel 1.23% and Stannous fluoride 0.4% to evaluate surface changes incorporated. 180 cut wires were used in this study; out of which half were SS and the other half were TMA wires. These wires were immersed for 10 minutes, 1 hour and 24 hours in each agent. Scanning electron microscope was also utilized to analyze the surface alterations. Results: The roughness of these wires increased after immersing in prophylactic agents. An increase in the surface roughness was found with SS wires in stannous fluoridesolution and APF gel on immersion at 10 minutes, 1 hour, and 24 hours’ time intervals with p-value being significant at 24 hour time in stannous fluoride. Conclusion: Orthodontists must avoid the contact of orthodontic wires containing titanium protective coating with prophylactic agents. Bangladesh Journal of Medical Science Vol.22 (Special Issue) 2023 p.47-51

Thermally controllable electromagnetically induced transparency in a coupled terahertz metamaterial

We investigate the thermally controllable electromagnetically induced transparency (EIT) effect in a planar terahertz (THz) metamaterial configuration comprising metallic semi-circular split ring resonators (MSCSRR) integrated with indium antimonide (InSb). In transmission configuration, a transparency window is observed by placing a horizontal cut wire (HCW) in close proximity to the MSCSRR. It develops by frequency detuning and strong near-field coupling between both the bright resonators. The transparency window is found to be controllable with temperature along with the structural parameters of the unit cell. The blue shift of 0.028 THz is observed when the temperature increases from 260 K to 320 K. Moreover, the group delay of the designed EIT structure can also dynamically tune by varying temperature of InSb. The shift from 3.19 ps to 1.98 ps is observed when the temperature increases from 260 K to 320 K. We used a coupled harmonic oscillator model to thoroughly understand the coupling between resonators and interpret the transparency effect. Our findings can be closely predicted from the model. The present study can be significant for the development of active and controllable terahertz photonic components such as slow light systems, buffers, etc.

Dual-band electromagnetically induced transparency terahertz metamaterial based on U-like resonator and metallic cut wire for sensing application

In this paper, a new scheme for dual-band terahertz electromagnetically induced transparency (EIT) is reported using a simple metamaterial structure, whose surface structure is composed of periodically arranged U-like resonator and metallic cut wire. Two EIT peaks located at 0.65 THz and 1.26 THz with an average transmission intensity of greater than 93% are realized, the formation mechanism of two transparent peaks is mainly attributed to the coupling of bright-bright mode, which is verified by their near-field distributions. Structure parameter changes of metamaterial provide a great ability to regulate and control the performance of two transparent peaks. Interestingly, by replacing the lower baseline of U-like resonator with vanadium dioxide (VO2), the designed metamaterial can dynamically tune the number of EIT peaks. It is revealed that dual-band transparency could be actively converted to single-band transparency by merely varying the properties of VO2 from metallic state to insulating state without changing the structure complexity, and the maximum amplitude modulation depth could reach 93.1%. Further application of designed metamaterial related to sensing is discussed. The designed metamaterial with these excellent features could pave the way for the applications of terahertz technology-related fields.

Terahertz Electromagnetically Induced Transparency with Electric-Field-Coupled Inductor-Capacitor Resonators on LCP Substrate

Electromagnetically induced transparency (EIT) metamaterials (MTMs) based on the bright-dark mode theory have gained great interest in slow light, sensing, and energy storage in recent years. Typically, various split ring resonators with magnetic response have been proposed as dark resonators in EIT MTMs. Here, we have employed a cut-wire (CW) and two electric-field-coupled inductor-capacitor (ELC) resonators with a pure electrical response on a liquid crystal polymer (LCP) substrate with a low loss tangent to fulfill the EIT effect in the terahertz (THz) region. The former works as the bright mode, and the latter functions as the dark mode. The EIT phenomenon results from the destructive interference between these two modes, which can be verified by numerical simulation and near field distribution. In addition, a Lorentz oscillator model was studied to quantitatively analyze the relationship between the coupling strength and the coupling distance. As a demonstration, an EIT MTM device with 5000 units was fabricated and characterized, which showed a transmission window with a peak value of 0.75 at 0.414 THz. This work may inspire new multifunctional EIT MTMs, especially the flexible applications at THz frequencies.

Conversion and Active Control between Electromagnetic Induced Transparency and Absorber in Terahertz Metasurface

In this study, we use a phase-changing material vanadium dioxide (VO2) to design a multilayer metasurface structure to achieve the transition from an electromagnetically induced transparency(EIT) device to an absorber. The structure consists of a gold layer, a polyimide spacer layer, a VO2 layer, and a sapphire substrate. The top layer consists of one cut wire and two split-ring resonators with the same parameters. When the VO2 layer is in its insulating phase at room temperature, the peak of the EIT device will appear near 1.138 THz. When the VO2 layer is in the metallic state, two absorption peaks above 99.5% appear separately at 1.19 and 1.378 THz, respectively. To the best of our knowledge, this is the first time that a coupled mode equation is used to perform theoretical calculations for EIT devices and perfect absorbers simultaneously, and this is also the first time that coupled mode equations are used for the theoretical calculations of two absorption peaks in an absorber. The proposed metasurface combines the advantages of terahertz absorption, EIT and active device control, which will provide more ideas for the design of future terahertz devices and is also significant for the design and development of radomes for future stealth aircraft.

Fuse welding and tin integration automatic machining device

In order to solve the problems of low efficiency and difficulty in adding tin to the end cap in the production process of the fuse, the unstable amount of tin resulted in over-welding and fake-welding. This paper designed and manufactured a set of automatic equipment for welding and adding tin to the fuse. The feeding device can accurately feed the end cap; a set of disc cutter structures with a feeding machine is used to cut the tin wire, and the cut tin wire accurately falls into the end cap of the fuse. The heating device is designed to melt the tin wire into liquid in the end cap. The cooling device makes the liquid tin condense into a solid in the end cap to realize the function of automatically adding tin to the end cap of the fuse. Through the actual production verification, it is proved that the equipment structure is reasonable and can meet the actual production requirements.

Broadband Plasmon‐Induced Transparency to a Electromagnetically Induced Absorption Conversion Metastructure Based on Germanium

AbstractA Germanium (Ge) metastructure with switching features from broadband plasmon‐induced transparency (PIT) and electromagnetically induced absorption (EIA) is presented, which forms a broadband PIT through the near‐field coupling between the localized plasmon resonance and the Mie resonance employing four gold cut wires as bright plasmon resonators and four C‐shaped dielectric rings as dark plasmon resonators. A wide transparent window above 0.9 is achieved covering from 0.622 to 0.823 THz with a relative bandwidth of 27.8%. In addition, through phase modulation, a magnetic dipole is generated by the constructive interference of the near‐field coupling of the three resonators to realize the PIT to EIA conversion. In addition, a grid‐like metastructure is introduced to realize the PIT to EIA conversion by phase modulation. To enhance the EIA bandwidth, another layer of C‐shaped reflection plate resonator is introduced to increase the dark mode loss, and a layer of frequency selective surface composed of cross‐shaped resonators is also used. Thus under the dual effect, a wide absorption window above 0.75 is achieved covering from 0.647 to 0.756 THz with a relative bandwidth of 15.5%.

Extensible Continuum Manipulator Toward In-situ Explosive Ordnance Disposal

Abstract Homemade bombs made by terrorists threaten seriously the social public security. Now, it is still a challenge to guarantee safety without destroying bombs. Compared with the destructive explosive disposal approach employing rigid robots, we proposed an in-situ explosive disposal method, which takes advantage of an extensible continuum manipulator to pass through obstacles and cut wires by end-effector. The spring-based continuum manipulator has six-degrees-of-freedom and is 400 mm in length but only 15 mm in diameter. Also, we have created only a 15 g end-effector that can cut 1-mm-diameter copper wire and embed a miniature camera. According to the experiment, a single continuum manipulator has around 2 mm repeatability accuracy and can carry a 50 g weight. Without special training, the operator can control the integrated explosive ordnance disposal (EOD) robot to complete a simulation mission in approximately five minutes. This paper broadens the application of the continuum manipulator and gives a unique solution for EOD robots.

Effectiveness of asparaginase on reducing acrylamide formation in bakery products according to their dough type and properties

Effect of asparaginase was tested in different biscuit and cracker doughs, and wafer batter by changing processing conditions such as enzyme dosage, dough resting time and temperature, mixing speed and time, and mixing procedure of the recipe components. Acrylamide reductions achieved were 96, 80, 54% in rotary cut biscuits, crackers and wire cut cookies, respectively due to high water activity of their dough. Asparaginase did not affect surface color or spread ratio. There was a positive correlation between asparagine content and acrylamide formation except for rotary molded biscuit doughs. No significant decrease was found in rotary molded biscuits because of low water (water activity of 0.70) and high fat content. This indicated that water activity of dough is an important factor for the effectiveness of asparaginase treatment. The results suggested that water activity value exceeding 0.75 is needed in the dough to effectively reduce asparagine, so acrylamide in bakery products.

A Novel Method for Carbendazim High-Sensitivity Detection Based on the Combination of Metamaterial Sensor and Machine Learning.

Benzimidazole fungicide residue in food products poses a risk to consumer health. Due to its localized electric-field enhancement and high-quality factor value, the metamaterial sensor is appropriate for applications regarding food safety detection. However, the previous detection method based on the metamaterial sensor only considered the resonance dip shift. It neglected other information contained in the spectrum. In this study, we proposed a method for highly sensitive detection of benzimidazole fungicide using a combination of a metamaterial sensor and mean shift machine learning method. The unit cell of the metamaterial sensor contained a cut wire and two split-ring resonances. Mean shift, an unsupervised machine learning method, was employed to analyze the THz spectrum. The experiment results show that our proposed method could detect carbendazim concentrations as low as 0.5 mg/L. The detection sensitivity was enhanced 200 times compared to that achieved using the metamaterial sensor only. Our present work demonstrates a potential application of combining a metamaterial sensor and mean shift in benzimidazole fungicide residue detection.