Gating System Research Articles

Design a Gating System for an Aluminum Cast Three-Way Pipe in Sand Casting

The study of aluminum casting work with market demand in the metal casting industry, designing a gating system in aluminum casting using a three-way pipe-shaped sand mold workpiece as a basic shape template in metal casting, namely a flat-face core box with a core. The gating system has a metal inlet with design variables including the pouring height, pouring basin cross-sectional area, rest basin cross-sectional area, running system cross-sectional area and inlet cross-sectional area. From the studying and designing, actual casting experiments were conducted and simulation behavior was analyzed using Cast-Designer software to make decisions and find appropriate design approaches from analyzing simulation results including liquid metal filling time, molten metal flow behavior, metal solidification time and shrinkage porosity formation of the workpiece. The results of the casting experiment and behavior simulation were able to cast the pipe workpiece which is a flat-face core box mold. The analysis results from the software can be used for actual pouring, where the fully cast mold successfully produced a complete workpiece. This can be a guideline for future improvements to reduce the shrinkage of actual cast workpieces.

Short Lysine-Containing Tripeptide as Analgesic Substance: The Possible Mechanism of Ligand–Receptor Binding to the Slow Sodium Channel

A possible molecular mechanism of the ligand–receptor binding of Ac-Lys-Lys-Lys-NH2 (Ac-KKK-NH2) to the NaV1.8 channel that is responsible for nociceptive signal coding in the peripheral nervous system is investigated by a number of experimental and theoretical techniques. Upon Ac-KKK-NH2 application at 100 nM, a significant decrease in the effective charge carried by the NaV1.8 channel activation gating system Zeff is demonstrated in the patch-clamp experiments. A strong Ac-KKK-NH2 analgesic effect at both the spinal and supraspinal levels is detected in vivo in the formalin test. The distances between the positively charged amino groups in the Ac-KKK-NH2 molecule upon binding to the NaV1.8 channel are 11–12 Å, as revealed by the conformational analysis. The blind docking with the NaV1.8 channel has made it possible to locate the Ac-KKK-NH2 binding site on the extracellular side of the voltage-sensing domain VSDI. The Ac-KKK-NH2 amino groups are shown to form ionic bonds with Asp151 and Glu157 and a hydrogen bond with Thr161, which affects the coordinated movement of the voltage sensor up and down, thus modulating the Zeff value. According to the results presented, Ac-KKK-NH2 is a promising candidate for the role of an analgesic medicinal substance that can be applied for pain relief in humans.

Dosimetric calibration of anatomy-specific ultra-high dose rate electron irradiation platform for preclinical FLASH radiobiology experiments.

FLASH radiation therapy (RT) offers a promising avenue for the broadening of the therapeutic index. However, to leverage the full potential of FLASH in the clinical setting, an improved understanding of the biological principles involved is critical. This requires the availability of specialized equipment optimized for the delivery of conventional (CONV) and ultra-high dose rate (UHDR) irradiation for preclinical studies. One method to conduct such preclinical radiobiological research involves adapting a clinical linear accelerator configured to deliver both CONV and UHDR irradiation. We characterized the dosimetric properties of a clinical linear accelerator configured to deliver ultra-high dose rate irradiation to two anatomic sites in mice and for cell-culture FLASH radiobiology experiments. Delivered doses of UHDR electron beams were controlled by a microcontroller and relay interfaced with the respiratory gating system. We also produced beam collimators with indexed stereotactic mouse positioning devices to provide anatomically specific preclinical treatments. Treatment delivery was monitored directly with an ionization chamber, and charge measurements were correlated with radiochromic film measurements at the entry surface of the mice. The setup for conventional dose rate irradiation utilized the same collimation system but at increased source-to-surface distance. Monte Carlo simulations and film dosimetry were used to characterize beam properties and dose distributions. The mean electron beam energies before the flattening filter were 18.8 MeV (UHDR) and 17.7 MeV (CONV), with corresponding values at the mouse surface of 17.2 and 16.2 MeV. The charges measured with an external ion chamber were linearly correlated with the mouse entrance dose. The use of relay gating for pulse control initially led to a delivery failure rate of 20% (±1 pulse); adjustments to account for the linac latency improved this rate to<1/20. Beam field sizes for two anatomically specific mouse collimators (4 × 4 cm2 for whole-abdomen and 1.5 × 1.5 cm2 for unilateral lung irradiation) were accurate within<5% and had low radiation leakage (<4%). Normalizing the dose at the center of the mouse (∼0.75cm depth) produced UHDR and CONV doses to the irradiated volumes with>95% agreement. We successfully configured a clinical linear accelerator for increased output and developed a robust preclinical platform for anatomically specific irradiation, with highly accurate and precise temporal and spatial dose delivery, for both CONV and UHDR irradiation applications.

Influence of Shape of Gating System on Pouring Time and Filling of a Sprue with the Use of MAGMA5 Optimization

Influence of Shape of Gating System on Pouring Time and Filling of a Sprue with the Use of MAGMA5 Optimization

High-speed bioimpedance-based gating system for radiotherapy: Prototype and proof of principle.

To investigate a novel bioimpedance-based respiratory gating system (BRGS) designed for external beam radiotherapy and to evaluate its technical characteristics in comparison with existing similar systems. The BRGS was tested on three healthy volunteers in free breathing and breath-hold patterns under laboratory conditions. Its parameters, including the time delay (TD) between the actual impedance change and the gating signal, temperature drift, root mean square (RMS) noise, and signal-to-noise ratio (SNR), were measured and analyzed. The gate-on TD and the gate-off TD were found to be 9.0±2.0ms [mean±standard deviation (M±SD)] and 7.2±1.3ms, respectively. The temperature drift of the BRGS output signal was 0.02 Ω after 30 min of operation. RMS noise averaged 0.14±0.05 Ω (M±SD) for all subjects and varied from 0.08 to 0.20 Ω with repeated measurements. A significant difference in SNR (p<0.001) was observed between subjects, ranging from 4 to 15. The evaluated bioimpedance-based gating system showed a high performance in real-time respiratory monitoring and may potentially be used as an external surrogate guidance for respiratory-gated external beam radiotherapy. Direct comparison with commercially available systems, 4D correlation studies, and expansion of the patient sample are goals for future preclinical studies.

Automated optimization of gating system through numerical simulation

Casting is a process for the production of complex shapes. Defects are unavoidable in any casting process. An efficient method of eliminating such defects can improve the process capability of the casting system. Computer simulation can save time, resources, and money in foundry trials, but it necessitates more human effort in terms of preparing the inputs and appropriately interpreting the results. In this work, a new method for evaluating and optimizing gating system design utilizing a simulation tool is proposed. It is possible to automatically modify the gating design with the help of CAD and casting simulation software from a given initial design and boundary conditions, and to check whether the design is effective to eliminate defects. Further this takes less human effort, making it more useful for industrial applications. The suggested methodology is demonstrated by autonomously optimizing the gating system for two industrial components and validated by producing actual castings made in sand molds.

EFFECTS OF DIFFERENT COOLANT MEDIA ON THE COOLING PERFORMANCE OF INJECTION MOLD PRODUCT

The injection molding process involves heating a thermoplastic polymer above its melting point and injecting it into a mold. The polymer then cools and solidifies to form the final part. The process consists of four stages: clamping, injection, cooling, and ejection. Among these stages, cooling plays a crucial role as it requires an efficient cooling system to transfer heat from the mold at a consistent rate, ensuring high-quality final products. This project specifically focuses on investigating the impact of different cooling media used in the cooling system for the mold. The aim is to compare the effectiveness of various cooling media on the cooling performance of the injection-molded product. Different types of coolants, including water, oil, or other solution mixtures, have been considered for their ability to reduce or regulate the temperature of the system. CAD modeling was prepared for the case study, along with a pre-designed conformal cooling channel and gating system. After conducting the simulation analysis, water emerged as the most effective coolant, demonstrating superior results compared to other coolant options. The results also highlight the feasibility of using alternative coolants that offer comparable cooling performance.

Simulation Study of Sand Casting by Using Runner &amp; Gates Modification in Gating System

Abstract: Sand casting remains a prevalent method for manufacturing complex metal components due to its costeffectiveness and versatility. However, optimizing the gating system, particularly through runner riser modification, is crucial for enhancing casting quality and minimizing defects. This study employs computer simulation techniques to investigate the effects of various modifications in the gating system on the solidification behavior and quality of castings. Through numerical simulations using advanced software tools, different configurations of the gating system are analyzed and compared, focusing on parameters such as flow rate, velocity distribution, and solidification patterns. The results reveal insights into the effectiveness of runner riser modification strategies in reducing defects like shrinkage and porosity, thereby improving the overall casting quality. Additionally, the study explores the trade-offs between different modification approaches in terms of cost, complexity, and performance. These findings contribute to the optimization of sand-casting processes, offering practical guidance for engineers and manufacturers aiming to enhance product quality and efficiency.

Optimization of Multi-Gate System in Casting Process Based on Experimental Study

Abstract: This paper proposes a gating system design for casting process using an experimental study. The principle behind multi-gate system optimization is to eliminate defects such as compression gas inclusions, cold shorts and mixing etc. Industrial and research experience shows that the flow of molten metal in the gating system before entering the extraction cavity significantly influences the quality of the casting. In general, slow filling causes defects like cold shirt and mixing while fast filling causes inclusion of sand and causes defects like holes. A gating system consists of runners, sprue gates and filters. The position, number, size, and shape of these elements play an important role. A systematic methodology for gating design optimization considering filling rate maximization has been developed based on limiting constraints. These include pouring time, gating ratio, modulus of ingate, mold erosion, Reynolds number at ingate section and filling rate of molten metal. Molten metal kinematics viscosity similar to that of liquid water can be used to determine the fillings and flowrate of the molten metal in the mold cavity. Aluminum generally has the same kinematics as water. Thus the water flow can be studied by adding the necessary design improvements to the multi-gate system, from which it will be easier to detect defects and will be easier to detect defects and will greatly improve the overall casting quality

Based ATP-gating mechanism for detection of alkaline phosphatase in single-glass micropipettes functionalized by three-dimensional DNA network.

The construction of gating system in artificial channels is a cutting-edge research direction in understanding biological process and application sensing. Here, by mimicking the gating system, we report a device that easily synthesized single-glass micropipettes functionalized by three-dimensional (3D) DNA network, which triggers the gating mechanism for the detection of biomolecules. Based on this strategy, the gating mechanism shows that single-glass micropipette assembled 3D DNA network is in the "OFF" state, and after collapsing in the presence of ATP, they are in the "ON" state, at which point they exhibit asymmetric response times. In the "ON" process of the gating mechanism, the ascorbic acid phosphate (AAP) can be encapsulated by a 3D DNA network and released in the presence of adenosine triphosphate (ATP), which initiates a catalyzed cascade reaction under the influence of alkaline phosphatase (ALP). Ultimately, the detection of ALP can be responded to form the fluorescence signal generated by terephthalic acid that has captured hydroxyl radicals, which has a detection range of 0-250mU/mL and a limit of detection of 50mU/mL. This work provides a brand-new way and application direction for research of gating mechanism.

Analysis of the Effect of Feeder Volume on Shrinkage Porosity Defects in Piston Products through the Gravity Die Casting Process

To achieve defect-free casting (soundness casting) with a minimal amount of shrinkage porosity, refinement during the casting process is necessary. In the gravity die casting process, there are parameters that lead to product defects, especially in the casting design, focusing on the gating system and feeder system as pathways for the flow of molten metal to supply the molten metal into the mold cavity. This research was conducted to examine the effect of adding feeder dimensions on shrinkage porosity, specifically on Al-Si piston products with a Silicon content of 12-13%. Feeder dimensions were varied in nine variations by adding height and width to the feeder gate, initially measuring 90mm in height and 32mm in width, along with the addition of insulation to the feeder to retain the heat of the casting process. Cooling used water and argon, with water placed at the center core and pin core and argon placed on the outer mold, with a solidification time of 150 seconds and pouring time of 3 seconds considered constant. This study used a Computer Aided Engineering (CAE) approach, namely MagmaSoft or the application of software to model the gravity casting system process. The results showed the lowest percentage of shrinkage at feeder dimensions of 114mm in height and 45mm in width with a mold temperature of 220°C was 0.76% of the product

Numerical Simulation of Sand Casting of Stainless Steel Pump Impeller

This paper investigates the casting defects of a stainless steel pump impeller manufactured through the sand casting process. The material characterization of austenitic steel AISI 316L was initially carried out, which examined the chemical composition of the casting and its microstructure. The next step was to determine the cause of the casting defects using numerical simulations. The numerical simulations were performed using ProCAST software (Version 18.0). Initial results of the filling and solidification simulations were conducted using the parameters employed in the actual casting process, revealing casting defects in corresponding locations. The casting process was subsequently modified to achieve improved results. This involved reconstructing the gating system, redesigning the riser, and incorporating a cylindrical chiller. The results show that the modified casting process significantly reduces the occurrence of defects in the final product. The study provides useful insights into the analysis and modification of the casting process for stainless steel pump impellers produced through sand casting. The results can help improve the quality of such products and reduce production costs associated with casting defects.

Comprehensive beam delivery latency evaluation for gated proton therapy system using customized multi-channel signal acquisition platform.

Beam delivery latency in respiratory-gated particle therapy systems is a crucial issue to dose delivery accuracy. The aim of this study is to develop a multi-channel signal acquisition platform for investigating gating latencies occurring within RPM respiratory gating system (Varian, USA) and ProBeam proton treatment system (Varian, USA) individually. The multi-channel signal acquisition platform consisted of several electronic components, including a string position sensor for target motion detection, a photodiode for proton beam sensing, an interfacing board for accessing the trigger signal between the respiratory gating system and the proton treatment system, a signal acquisition device for sampling and synchronizing signals from the aforementioned components, and a laptop for controlling the signal acquisition device and data storage. RPM system latencies were determined by comparing the expected gating phases extracted from the motion signal with the trigger signal's state turning points. ProBeam system latencies were assessed by comparing the state turning points of the trigger signal with the beam signal. The total beam delivery latencies were calculated as the sum of delays in the respiratory gating system and the cyclotron proton treatment system. During latency measurements, simulated sinusoidal motion were applied at different amplitudes and periods for complete beam delivery latency evaluation under different breathing patterns. Each breathing pattern was repeated 30 times for statistical analysis. The measured gating ON/OFF latencies in the RPM system were found to be 104.20±13.64ms and 113.60±14.98ms, respectively. The measured gating ON/OFF delays in the ProBeam system were 108.29±0.85ms and 1.20±0.04ms, respectively. The total beam ON/OFF latencies were determined to be 212.50±13.64ms and 114.80±14.98ms. With the developed multi-channel signal acquisition platform, it was able to investigate the gating lags happened in both the respiratory gating system and the proton treatment system. The resolution of the platform is enough to distinguish the delays at the millisecond time level. Both the respiratory gating system and the proton treatment system made contributions to gating latency. Both systems contributed nearly equally to the total beam ON latency, with approximately 100ms. In contrast, the respiratory gating system was the dominant contributor to the total beam OFF latency.

Effect of Gating System Design on the Quality of Aluminum Alloy Castings

In this paper, a naturally pressurized gating system has been designed to reduce the turbulence of the melt during casting. The influence of gate dimensions, foam filters, a trident gate and a vortex element were evaluated. Their effect on melt velocity, flow characteristics, number of oxides, casting properties and mechanical properties were observed. ProCAST Simulation software v.2023 and a water flow test were also evaluated to assist in the experimental evaluation of the castings. Melts showed a relationship between melt velocity and porosity of castings. Quantitative evaluation of the surface porosity showed a trend of decreasing porosity with decreasing melt velocity. The greatest reduction in the melt velocity was achieved by a M4 design, which was associated with the highest reduction in the oxides. The pores analyzed proved the presence of oxide layers on their inner surface and a possible theory of pore formation when the initiator of porosity is entrained double oxide layers. The best metal yield was achieved with M1, but the difference between M2 and M4 was negligible (2–5% yield difference), so it can be stated that the beneficial effect of the M4 design in providing the best quality castings is not negated by the increase in metal yield.

Elimination of Shrinkage in Ductile Iron Castings Using Computer Simulation of Casting and Solidification

The production of high-quality castings without foundry defects at minimal production costs is a constant priority for foundries. Innovation and optimization of production processes are key to achieving this goal. Computer simulation of foundry processes offers a modern alternative to expensive and time-consuming experiments in real foundries and provides a reliable representation and analysis of casting and solidification processes. A detailed analysis of the casting and solidification simulation results allows the prediction of various risks that can cause defects in cast castings, thereby reducing their quality and, last but not least, the cost of their production. This paper deals with the analysis of a computer simulation of the casting of a brake disc in a Slovak foundry. This brake disc has had shrinkages and micro shrinkages that reduce the internal quality of the casting. These defects occurred in the ribs in the upper part of the casting under the feeders. A computer simulation of the casting and solidification of this casting was made according to the real conditions. It turned out that the designed gating system with a system of feeders was not sufficient to eliminate the emerging defects. A new layout for the feeders was proposed, which ultimately eliminated the occurrence of defects based on the results of the computer simulation. The input parameters were set to be as close as possible to the actual needs of the foundry. Moreover, 3D models of the assemblies were designed in SolidWorks Premium 2015 x64 Edition CAD software, and the filling and solidification simulations were performed using the NovaFlow &amp; Solid CV 4.6r42 simulation program.

Deep panoramic depth prediction and completion for indoor scenes

We introduce a novel end-to-end deep-learning solution for rapidly estimating a dense spherical depth map of an indoor environment. Our input is a single equirectangular image registered with a sparse depth map, as provided by a variety of common capture setups. Depth is inferred by an efficient and lightweight single-branch network, which employs a dynamic gating system to process together dense visual data and sparse geometric data. We exploit the characteristics of typical man-made environments to efficiently compress multi-resolution features and find short- and long-range relations among scene parts. Furthermore, we introduce a new augmentation strategy to make the model robust to different types of sparsity, including those generated by various structured light sensors and LiDAR setups. The experimental results demonstrate that our method provides interactive performance and outperforms state-of-the-art solutions in computational efficiency, adaptivity to variable depth sparsity patterns, and prediction accuracy for challenging indoor data, even when trained solely on synthetic data without any fine tuning.

Classifying Optical (Out)bursts in Cataclysmic Variables: The Distinct Observational Characteristics of Dwarf Novae, Micronovae, Stellar Flares, and Magnetic Gating

Cataclysmic variables can experience short optical brightenings, which are commonly attributed to phenomena such as dwarf novae outbursts, micronovae, donor flares, or magnetic gating bursts. Since these events exhibit similar observational characteristics, their identification has often been ambiguous. In particular, magnetic gating bursts and micronovae have been suggested as alternative interpretations of the same phenomena. Here we show that the timescales and energies separate the optical brightenings into separate clusters consistent with their different classifications. This suggests that micronovae and magnetic gating bursts are in fact separate phenomena. Based on our findings, we develop diagnostic diagrams that can distinguish between these bursts/flares based on their properties. We demonstrate the effectiveness of this approach on observations of a newly identified intermediate polar, CTCV J0333-4451, which we classify as a magnetic gating system. CTCV J0333-4451 is the third highest spin-to-orbital period ratio intermediate polar with magnetic gating, suggesting that these bursts are common among these rare systems.

Application of sand mold casting modelling for casting pump volute

This work details the development of a gating system for sand mold casting utilizing advanced computer technologies in the casting industry. The study employs advanced methods to manufacture a component referred to as the pump volute. Made from the EN-GJN-HV600(XCr23) alloy, this component displays superior technological characteristics, notably for the production of sand mold gravity castings. SolidWorks software is utilized to generate 3D models of the component and the fill system based on predetermined dimensions. Subsequently, the component is imported into Pro-CAST software to conduct a simulation. Various time parameters were inputted during the study. Post-simulation, defects were scrutinized, and the casting system underwent modification to eliminate them. The process was iterated on the software and its efficacy was verified to be faultless.

Chest Wall to Heart Distance Reproducibility in Postoperative Deep Inspiration Breath-Hold Radiotherapy for Left-Sided Breast Cancer Using an Anzai Laser Sensor With Visual Feedback.

Background Left-sided breast cancer radiotherapy may increase the risk of cardiovascular death due to possible heart irradiation. Thereproducibility of the chest wall to heart distance in deep inspiration breath-hold (DIBH) was studied using a laser sensor with visual feedback. Methodology A total of 10 consecutive postoperative left-sided breast cancer cases receiving DIBH radiotherapy between December 2022 and September 2023 were retrospectively investigated. The prescribed dose was 50 Gy in 25 fractions. An Anzai respiratory gating system, AZ-733VI (Anzai, Tokyo, Japan), was employed that has a laser displacement sensor and a visual feedback device. An Elekta linac with a cone-beam CT unit, Axesse (Elekta AB, Stockholm, Sweden), was used in this study. The interfractional changes in the chest wall to heart distance among 25 fractions were analyzed for each of the 10 patients in each coordinate axis. In addition, the median with the 95% confidence interval (CI) and interquartile range (IQR) for all 250 fractions were calculated in each axis to assess the reproducibility of our DIBH technique. Results The medians of the interfractional changes in the chest wall to heart distance in each of the 10 patients ranged from -2 mm to 3 mm, -1 mm to 3 mm, and -2 mm to 1 mm in the lateral (X), superior-inferior (Y), and anterior-posterior (Z) directions, respectively. For all 10 cases, the medians were 1 mm (95% CI = 0.72 to 1.28 mm) in X, 1 mm (95% CI = 0.76 to 1.24 mm) in Y, and 0 mm (95% CI = -0.20 to 0.20 mm) in Z directions, whereas the IQRs were 4 mm in X, 2 mm in Y and 2 mm in Z directions. The measured IQRs were two to three times smaller than those shown in a previous report without visual feedback, suggesting a clinical advantage of the visual feedback in DIBH for left-sided breast cancer radiotherapy. The DIBH solution shown in this study required approximately 10 minutes from room-in to room-out, thereby not reducing the daily number of patients. Conclusions Our DIBH approach with visual feedback achieved better distance reproducibility between the chest wall and heart by a factor of two to three in terms of IQR compared to the previously reported data without visual feedback. Patient throughput was also favorable. To our knowledge, this is the first report demonstrating the chest wall to heart distance reproducibility in DIBH with visual feedback.

OPTIMIZING SHRINKAGE DEFECTS IN GREY CAST IRON BUTTERFLY VALVE CASTING: A SIMULATION AND EXPERIMENT-BASED APPROACH

The study focused on addressing casting defects in green sand casting that have negatively impacted the quality of the butterfly valve body. By employing various methods such as observation, interviews, numerical experimentation, and simulation, the researchers aimed to develop and evaluate a sand-casting technique for the butterfly valve body. Solidworks software was used to model the component and its gating system, while ProCAST software enabled mold filling and solidification analyses. The goal was to minimize shrinkage porosities in the cast butterfly valve body by optimizing process parameters through numerical experiments and the Taguchi technique. Analysis of variance (ANOVA) using Minitab 18 software analyzed the results. Through this research, the sand mold-related defect was reduced from 10% to 3%, and the special shrinkage defect was reduced from 26% to 2% by using a simulation of casting.