Metallic Nut Research Articles

Study on Joint Model Simplification for Finite Element Analysis of Bamboo/Wood-Oriented Strand Board Furniture.

Board furniture's performance and scientific design are making it popular. Research on simplifying furniture joints reduces design cycles and costs and improves structural safety. In this article, using a cantilever beam to calculate deflection theoretically simplifies the L-shaped component model and yields a joint elastic modulus formula. Finite element analysis (FEA) confirms the effectiveness of this simplified model by comparing its results with experimental data. In simplified components, the joint elastic modulus increases with length (l2) and stabilizes at l2/b ≥ 6 (b is the board's thickness). The variation pattern of the joint elastic modulus equals that of the stiffness, proving its usefulness in assessing component deformation resistance. Furthermore, the component strength and stiffness are also affected by the screw spacing and connector type. In particular, the connectors type affects bamboo-oriented strand board (BOSB) component performance more than wood-oriented strand board (WOSB). Compared to WOSB, BOSB components have superior strength and stiffness and are more stable. The recommended screw spacing for L-shaped components is 48 mm. BOSB components fixed with two-in-one and metal nuts utilizing threads embedded in the board have better strength and stiffness, while for WOSB components, nylon nuts, and wooden dowel pins are more appropriate for securing.

Motion of a metal nut sliding around a vertical loop

An experiment is described where a metal nut was allowed to slide from the top to the bottom of a vertical wire loop. An interesting feature is that the normal reaction force on the nut decreases to zero and reverses direction before the nut reaches the bottom of the loop.

Specific Object Picking Robotic Arm Using Haar Cascades

This project shows a robotic arm that can pick up objects. It was made with accuracy and speed in mind for use in factories. The robotic arm is very good at picking up metal nuts. It uses cutting edge technologies, like Haar cascade to find objects and inverse kinematics to figure out angles very accurately, to make its moves more exact and dexterous. A powerful computer vision method called Haar cascade is used to find metal nuts in the robotic arm's working environment. To do this, positive and negative pictures are used to train a Haar cascade classifier, which makes a model that can recognize the unique traits of metal nuts. The object recognition process makes sure that the nuts are located correctly, which lets the robotic arm deal with them in a controlled and precise way. The robotic arm uses inverse kinematics along with Haar cascading to figure out the exact joint angles needed for smooth, controlled movement. Inverse kinematics is very important for figuring out the joint setups that are needed to place the robotic arm's end-effector exactly on top of the metal nuts that have been found. Haar cascading for finding objects and inverse kinematics for accurate angle estimates work together to make sure that the robotic arm can pick up metal nuts in a variety of space arrangements. This combined system is a high-tech way to automatethe picking of specific items in manufacturing and assembly lines. It shows how industrial automation can be used to improve accuracy, efficiency, and flexibility.

Machine Design Automation Model for Metal Production Defect Recognition with Deep Graph Convolutional Neural Network

Error detection has a vital function in the production stages. Computer-aided error detection applications bring significant technological innovation to the production process to control the quality of products. As a result, the control of product quality has reached an essential point because of computer-aided image processing technologies. Artificial intelligence methods, such as Convolutional Neural Network (CNN), can detect and classify product errors. However, detecting acceptable and small defects on base parts cannot be done with a high rate of accuracy. At this point, it is possible to detect such minor errors with the help of the graph convolutional network, which has emerged as a new method. In this study, the defect elements on the surfaces of metal nut parts are determined through the graph convolutional network, and quality control is ensured. First, the surface images of the metal nut parts are captured. For this, a python-based Raspberry pi card and a modified camera system were installed. Adapters with three different zoom options are used on the camera system, depending on the part to be captured. The images obtained in the second step are sent to the other computer, which is used for image processing via the local server. In the third stage, image transformations are obtained by graphically separating the obtained images in white and black color tones on the second computer, and histogram maps of these images are drawn. Value ranges of these maps are determined and classified according to the value ranges obtained from the images of the defective parts. As a result, nine different models were analyzed. According to the analysis results, the graph convolutional neural network method gives 2.9554% better results than conventional methods.

Penile strangulation by a metallic nut in an 8-year-old male: A rare case report of urological emergency.

Introduction and importancePenile strangulation due to metallic objects in pediatric age groups is a rare urological emergency that warrant emergency management. Removal of metallic ring from strangulated penis poses a great challenge to urologist as it may require industrial gadgets. Multidisciplinary management involving psychiatrist is required. To the best of our knowledge, this is the first reported novel case of penile strangulation by a metallic nut in children in Tanzania. Furthermore, this case report shows that Industrial Manual Scissor metal (IMSMC) cutter offers a safe way of removing metallic nut from strangulated penis with few complications.Case presentationWe report a case report of penile strangulation in an 8 year-old boy by a metallic nut which stayed for 11 h prior to arriving at a tertiary hospital in Northern Tanzania. The reason for insertion of nut by a child was not clear.Clinical discussionOn arrival to the hospital the child was clinically stable but in pain. Local examination revealed a metallic nut at proximal penis with grossly edematous penis. A diagnosis of penile strangulation by metallic nut was reached and the child was planned for emergency surgery to remove the metallic nut. The metallic nut was successful removed by IMSMC. This technique has been used in adult with success with few complications and therefore opted in our setting. The child was also diagnosed with oppositional defiant disorder.ConclusionIndustrial Manual Scissor Metal cutter is a safe way of managing penile strangulation by a metallic nut in children.

Dimensional and roughness analysis of ABS polymer-based 3D printed nuts and bolts

Joining two parts is the most difficult part of any machinery or parts. Due to high mechanical strength and better output previously metallic nut and bolt has been used. Due to the heavy weight of nut and bolt sometimes fabricated/ manufactured final product is more heavily as per required weight. In this experimental research work, an effort has been made to fabricate a thermoplastic polymer-based nut and bolt using the 3D printer for commercially manufacturing. After the fabrication of nut and bolts dimensional analysis has been using vernier calliper and surface roughness optimization has been performed using surface roughness tester. In this research work, an effort has been made to fabricate an ABS based nuts and bolts assembly by 3D printing technology. Based on surface roughness and dimensional analysis it has been optimized that ABS based nuts and bolts are easily made by 3D printing technology. The main benefit of the research work, for repacing metallic nuts and bolts due to lightweight.

Automated In Situ Placing of Metal Components Into 3-D Printed FFF Objects

Screws are often used to connect 3-D printed parts to other objects. When screwing directly into printed plastic, the reliability is limited, and the connection can wear out over time. For more reliable connections, standard metal nuts are often inserted into slots designed into the object. This article presents an approach where nuts and other ferromagnetic components are integrated directly into the part while printing it. Our prototype machine is a modified Prusa-I3 fused filament fabrication printer with an electromagnetic pick and place tool. We introduce augmented slicing software, where the user can insert generic component models from a library and place them at arbitrary positions in the object. Cavities for the components and additional G-code commands for robotic placing are automatically generated and sent to the printer. A printed component tray is attached to the printbed, allowing different part configurations for each print. The pick and place unit is controlled by our OctoPrint plugin OctoPNP.

Semi-supervised anomaly detection for visual quality inspection

In this paper a semi-supervised method for the detection of anomalies in both texture- and object-based product images is presented. The method exploits a pre-trained Convolutional Neural Network (CNN) autoencoder that is blended with a statistical-based transformation of the neural network embedding layer in order to remove anomalies from the input image. The “cleaned” version of the input image is then compared with the input image itself in order to spatially localize the anomalies. The method does not require a specific training of the CNN to be applied to a new class of product, but it requires a very fast domain adaptation based on only “anomaly-free” examples. Experiments conducted on a publicly available dataset made of fifteen texture- and object-based classes show that overall performance is better than the state of the art of about 4%. In the case of texture-based classes the proposed method outperforms the state of the art of about 13%. In the case of object-based classes, the proposed method reaches overall the same performance of the state of the art. In this case, apart from 3 cases, that is “bottle”, “transistor” and “metal nut”, the proposed method performs better than the state of the art in 7 object classes out of 10.

Mutual Consistency-Ensured Bi-Directional GAN for Anomaly Detection

Anomaly detection is a challenging and fundamental issue in computer vision tasks. In recent years, Generative Adversarial Networks (GAN) and Bi-directional GAN based anomaly detection methods have achieved remarkable results. However, the performance of these approaches for anomaly detection depends on the ability to reconstruct a given normal image and to predict its latent variables. Therefore, we design a novel Bi-directional GAN-based anomaly detection model to improve these abilities. Especially, in order to reconstruct the image, we introduce the consistency loss for ensuring mutual mappings in both image and latent space. Moreover, we propose introducing the projection discriminator as an alternative of concatenating discriminator in order to perform efficient conditioning in the Bi-directional GAN model. In experiments, we evaluate the effectiveness of our model in MNIST and MVTec Metal Nut. Our experiment showed that our model allows us to detect various real anomalies such as bent, scratch, color, and flip, and outperforms the conventional ones.

A Facile Fabrication Route of Poly(Ethylene Glycol Phenyl Ether Acrylate) Photopolymers with Efficient Optical Response for Holographic Storage

A series of photopolymers based on ethylene glycol phenyl ethyl arylate (EGPEA) monomers and poly(methyl methacrylate) (PMMA) matrix with varying initiator concentrations and sample thicknesses have been synthesized and their optical performance characterized in this study. The advantages of lowering the initiator concentration, including a rather short initiation time within a few seconds; a sharp rising optical response; and a stable saturated diffraction efficiency are demonstrated. The variation in the diffraction efficiency and response time with the exposure energy under various sample thickness and initiator concentrations is examined; a diffraction efficiency as high as 80% and a relatively short response time of 12–39 s are attainable. The dependence of the normalized optical parameter “sensitivity” on the exposure time is depicted, and the peak value of S ranges vastly from about 0.2 to 1.2 × 104 cm/J within a period of 15 s or so, with a maximum value of nearly 1.2 × 104. Favorable evidence of low initiator concentration can further be found when the dependence of the saturated diffraction efficiency with the exposure energy is examined. The data from this study using a low initiator concentration cover a range of exposure energy from 100 to 800 mJ/cm2 and a saturated diffraction efficiency from about 15% to 80%. The successful image reconstruction of 6-membered-ring metal nuts on a hologram based on this EGPEA/PMMA photopolymer system using a reflective holographic recording setup is demonstrated to verify its applicability to holographic storage.

Hydrothermal aging of friction riveted thermoplastic composite joints for aircraft applications

In this paper, the sensitivity of carbon fiber reinforced polyether-ether-ketone friction riveted joints to hydrothermal aging was assessed, addressing the degradation mechanisms and post-aged quasi-static mechanical behavior of the joints. The joints were exposed to 71 °C and 95% relative humidity for 28 days. Despite the oxidation of the metallic nut and washer as well as cavitation and degradation of the composite, a 23% increase of joint mechanical performance was observed after 28 days of exposure. It is believed that the temperature and water uptake drove matrix post-crystallization at the surface of the fibers, which led to local strengthening of the composite in the rivet surrounding and, consequently, improved the joint residual strength.

Surface Texture Detection With a New Sub-mm Resolution Flexible Tactile Capacitive Sensor Array for Multimodal Artificial Finger

This work presents a flexible polyimide-based capacitive tactile sensing array with sub-millimeter spatial resolution. The sensor is conceived to be embedded in a multimodal artificial finger to detect and classify the texture morphology of an object’s surface. The proposed tactile sensor comprises a $16\times 16$ array of capacitive sensing units. Each unit is composed of a parallel square electrode pairs ( $340~ {\mu }\text{m}\,\,\times 340~ {\mu }\text{m}$ ) separated by a compressible air cavity and embedded into a flexible polyimide substrate. Standard MEMS microfabrication techniques were used to develop the sensor. The polyimide device was covered with a thin compressible PDMS layer to tune the normal pressure sensitivity and dynamic range (225–430 ${\mu }\text{m}$ thin PDMS layer resulting in 0.23–0.14 fF/kPa). The detection of the surface morphologies of a regular grating stamp for different orientation and a small metallic nut placed on the sensor is demonstrated, showing a 420 ${\mu }\text{m}$ spatial resolution. The proposed sensor represents a novel capacitive tactile sensing device with a sub-mm resolution of human fingertip sensitivity.

Glass Crystal Models: A First Approach to a Hidden Treasure of Teaching and Scientific Heritage

Glass crystal models arrived in Portugal around the late 19th century, when high schools, universities, and polytechnics were gradually provided with teaching collections to support science education. Therefore, they are an important material evidence of teaching methodologies of mineral and geology science in the 20th century. The Passos Manuel high school in Lisbon, owns a significant collection of scientific heritage, currently on a long-term loan at the National Museum of Natural History and Science and the University of Lisbon, which includes a set of 98 glass crystal models. Besides glass, these models are composed by adhesives, paper, cardboard, textile threads, paper/textile adhesive tapes, and metal nuts and screws. Also, they show several levels of intervention and different conservation states. In this paper, the first results of a multi-analytic approach to chemically characterize these objects’ material composition will be presented. Characterization was done based on portable equipment (pXRF), or by collecting small samples further analyzed using optical microscopy and FTIR-ATR techniques. This study allowed for a first distinction between original materials from the old repairs; to develop a more accurate assessment of the conservation condition; and finally, as one of the main aims of this work, to determine preventive conservation measures in order to better preserve these cultural objects.

Stepwise approach in the management of penile strangulation and penile preservation: 15-year experience in a tertiary care hospital

ABSTRACTObjective: To present our stepwise approach to the management of penile strangulation and penile preservation with 15 years’ experience in a tertiary care hospital, as penile strangulation is a rare urological emergency that requires immediate attention.Patients and methods: A prospective observational study was performed from March 2003 to December 2018 of patients presenting with penile strangulation to our hospital.Results: Nine patients with penile strangulation presented to us between March 2003 and December 2018. The most common motive for the application of a foreign body was sexual gratification (four patients). Three of the nine patients had a mental disorder. Objects used for strangulation included: metallic nut (three), metallic ring (two), plastic bottle (two), wooden hole (one), hammer head (one), and horse hair to control bleeding during circumcision (one). Most of the foreign bodies were located in the proximal penile region. The mean operative time was 38 min and three of the nine patients had complications.Conclusions: Penile strangulation is one of the rare urological emergencies experienced by a urologist. Removal of the foreign body can be difficult and there is no universal method of removal, as each case differs. So, following our stepwise approach can aid in removal of foreign body quickly and preserve the penis from fatal outcomes. Urologist should be aware of all the available armamentarium used for the removal of such foreign bodies.Abbreviation: SPC: suprapubic cystostomy

Stainless-Steel Column for Robust, High-Temperature Microchip Gas Chromatography.

This paper reports the first results of a robust, high-performance, stainless-steel microchip gas-chromatography (GC) column that is capable of analyzing complex real-world mixtures as well as operating at very high temperatures. Using a serpentine design, a 10 m column with an approximately semicircular cross-section with a 52 μm hydraulic diameter ( Dh) was produced in a 17 × 6.3 × 0.1 cm rectangular steel chip. The channels were produced using a multilayer-chemical-etch and diffusion-bonding process, and metal nuts were brazed onto the inlet and outlet ports allowing for column interfacing with ferrules and fused silica capillary tubing. After deactivating the metal surface, channels were statically coated with a ≈0.1 μm layer of 5% phenyl-1% vinyl-methylpolysiloxane (SE-54) stationary phase and cross-linked with dicumyl peroxide. By using n-tridecane ( n-C13) as a test analyte with a retention factor ( k) of 5, a total of 44 500 plates (≈4500 plates per meter) was obtained isothermally at 120 °C. The column was thermally stable to at least 350 °C, and rapid temperature programming (35 °C/min) was demonstrated for the boiling-point range from n-C5 to n-C44 (ASTM D2887 simulated-distillation standard). The column was also tested for separation of two complex mixtures: gasoline headspace and kerosene. These initial experiments demonstrate that the planar stainless-steel column with proper interfacing can be a viable alternative platform for portable, robust microchip GC that is capable of high-temperature operation for low-volatility-compound analysis.

Use of Savitzky-Golay Filter for Performances Improvement of SHM Systems Based on Neural Networks and Distributed PZT Sensors.

A considerable amount of research has focused on monitoring structural damage using Structural Health Monitoring (SHM) technologies, which has had recent advances. However, it is important to note the challenges and unresolved problems that disqualify currently developed monitoring systems. One of the frontline SHM technologies, the Electromechanical Impedance (EMI) technique, has shown its potential to overcome remaining problems and challenges. Unfortunately, the recently developed neural network algorithms have not shown significant improvements in the accuracy of rate and the required processing time. In order to fill this gap in advanced neural networks used with EMI techniques, this paper proposes an enhanced and reliable strategy for improving the structural damage detection via: (1) Savitzky–Golay (SG) filter, using both first and second derivatives; (2) Probabilistic Neural Network (PNN); and, (3) Simplified Fuzzy ARTMAP Network (SFAN). Those three methods were employed to analyze the EMI data experimentally obtained from an aluminum plate containing three attached PZT (Lead Zirconate Titanate) patches. In this present study, the damage scenarios were simulated by attaching a small metallic nut at three different positions in the aluminum plate. We found that the proposed method achieves a hit rate of more than 83%, which is significantly higher than current state-of-the-art approaches. Furthermore, this approach results in an improvement of 93% when considering the best case scenario.

Single Transsacral Screw and Nut Stabilization of Bilateral Sacroiliac Luxation in 20 Cats.

This article aims to describe the use of a single transsacral screw and nut in a cohort of cats with bilateral sacroiliac (SI) luxation and document its radiographic and clinical outcome. Medical records and radiographic studies of cats with bilateral SI luxation managed with a transsacral screw and nut stabilization were reviewed. Short-term follow-up included clinical examination and radiographs. Long-term follow-up was via owner questionnaire. Twenty consecutive cats with bilateral SI luxation were included. Six cats (35%) had additional musculoskeletal injuries that required stabilization. Luxations were stabilized with a single 2.7 cortical self-tapping transsacral screw and nylon nut (a metallic nut was used in one case). Postoperative radiographs confirmed SI reduction in all cats and a mean pelvic canal width ratio of 1.21 (a ratio of ≥1.1 was considered optimal). All cats available at follow-up examination were able to walk without signs of discomfort. Evaluation of follow-up radiographs showed maintenance of SI reduction and slight reduction of mean pelvic canal width ratio (1.18). Fourteen owner questionnaires were returned (median follow-up time of 40 months): nine cats were deemed to have normal activity and five cats were reported to have slight to mild reduced ability to jump or run. The use of transsacral screw and nut stabilization of bilateral SI luxation in cats is a successful, repeatable and safe technique.

Porcelain Faucet Handle Failure Analysis

A porcelain faucet handle failed after years of use in a residential rental property. Determining the cause of failure was hampered by the fact that the failed handle was no longer available. The analysis included mechanical testing of exemplar faucet handles to measure the reasonable forces that could be applied by hand and the forces necessary to cause failure. Interface geometry between the porcelain handle and the interior metal nut was a factor. Finite Element Analysis facilitated the study. Results showed that if the faucet handle had sustained damage during a gasket repair, then the failure could be accounted for.

Valuation Alteration: Stimuli Increase in Value When Preschoolers Deliver Them to Peers

We tested the effects of the repeated delivery of metal nuts to peers on the establishment of them as preferred stimuli for 4 preschool children. Prior to the conditioning procedure, metal nuts were relatively nonpreferred stimuli for the participants, as indicated by responses to mastered and acquisition tasks. We used pre- and postconditioning tests of reinforcer effectiveness, which included an ABAB reversal design for a mastered task and an AB design replicated across 4 acquisition tasks, delayed across participants. During the conditioning procedure, the participants were instructed to deliver a metal nut to a peer at the sound of a beep while they were denied access to the nuts themselves. Conditioning sessions continued until the participants demonstrated a low rate of delivery. Postconditioning tests demonstrated that repeatedly delivering the metal nuts to peers resulted in the metal nuts functioning as preferred stimuli for all participants.

Penile Strangulation by Self‐Placement of Metallic Nut: Corporal Cavernosa Tissue Showed Resilience to Thermal Burns Sustained at Removal

We report a case of a 37-year-old male who presented with a 12-hour history of a strangulating 2cm wide by 0.8 cm thick metallic nut on the penile shaft at the peno-scrotal junction. Unlike instances where these metallic objects are placed to enhance sexual stimulation this nut was rather placed to prevent intercourse. A Bosch electric circular grinder was successfully used for removal but a thermal burn to the penile tissues was sustained in the process as the hardness of the nut required a high energy to cut and its thickness did not allow for effective cooling during the process of removal. This resulted in a circumferential denudation of penile skin, a urethro-cutaneous fistula at the peno-scrotal junction and a mid-bulbar urethral stricture. The penile wound was subsequently covered with a split skin graft with a delayed closure of the urethrocutaneous fistula and a buccal mucosa patch urethroplasty for the mid bulbar stricture. Despite the degree of thermal burns sustained the patient has maintained good erectile function with grade four rigidity. The tunica albuginea and the underlying corpora cavernosa have shown a significant degree of resilience to thermal burns compared to the corpora spongiosum where the thermal burns led to a urethrocutaneous fistula.