Intricate Shapes Research Articles

Influence of electrode type and dielectric during EDM machining of Ti-6Al-4V

Aluminum is a popular material in various industries, especially in the aerospace, automotive, and medical industries due to its lightweight, high strength, and good thermal and electrical conductivities. Aluminium tooling in electrical discharge machining (EDM) is a cost-effective and efficient option for machining titanium parts with high precision and accuracy. Aluminium electrodes are mainly used to achieve close tolerances and precise surface finish. The use of aluminium tooling allows for the creation of complex and intricate shapes while reducing the risk of thermal damage to the workpiece. In this work, experiments are conducted with various levels of peak current (Ip), duty cycle (τ) and pulse on time (Ton) while the open circuit voltage (V) is kept constant. All the machining trials are carried out with both aluminium and copper tool electrodes with lemon peel biodiesel as dielectric. The performance measures considered during the work are material removal rate (MRR), tool wear rate (TWR), average surface roughness (Ra). The microstructural analysis is carried out on samples that exhibited high MRR. The test results revealed that the aluminium tool electrode is outperforming the copper electrode, while considering Ra and machining accuracy irrespective of TWR.

Brain Tumor Detection Using RNN

This research work aims to utilize the developed and evaluated Magnetic Resonance Imaging(MRI) technique for the classification of brain tumor and seizures employing Recurrent Neural Network (RNN). The medical science in the image processing is an emergent area that has suggested many progressive methods in detecting as well as analyzing a specific disease. Brain tumors treatment is recently getting progressively more challenging owing to the intricate shape,structureandthetextureoftumor.So,viaprogressingintheimageprocessing,differentmethodologies have been suggested for identifying the tumors inside brain. The progression in such area made a need for searching more upon the methods and approaches evolved for the extraction of tumor. Therefore, an extraction system the tumor from thebrainissuggestedutilizingMRIimages.Suchmethodincludesvariousproceduresofimageprocessing,likefiltering,theremovalofnoise,segmentation,andmorphologicalprocesses. Brain tumor extraction can be successfully achieved via conducting such processes upon. The cross-correlation is calculated between the changeable vector of a target and the zone of tumor for determining in what way the values of people of the zone of tumor are narrowly, associated utilizing the image processing and the RNN method accomplishing 99.71%accuracy. Key Word: Brain RNN, Image processing, Image segmentation, Feature extraction, Image classification

Microstructure and Mechanical Properties Analysis of Mild Steel with Different Groove Shape Welded Using GMAW

This paper will discuss the effect of welding variables on the transverse tensile strength and hardness of mild steel welding made by GMAW. The welding variables included are base metal thickness, welding voltage, wire feed speed (WFS), and base metal groove shape. The results show that higher welding transverse tensile strength has obtained higher FZ hardness, while they both increased with decreased welding heat input. E.g., the highest tensile strength (238 MPa) has shown 2162 HV at 768 J/mm heat input, while the lowest tensile strength (120 MPa) of welding made at 2376 J/mm has shown 2108 HV. The FZ of welding made at V groove-shaped base metal has higher hardness and transverse tensile strength, as shown 2159.5 HV and 215 MPa in order when compared to 177 MPa and 2147 HV for X groove-shaped. The hardness at V groove-shaped FZ had an average of 2159.5 HV, while the hardness at X groove-shaped had an average of 2147 HV at 10 mm base metal thickness. The increased hardness of V groove-shaped FZ could be related to the increased stresses at V groove-shaped due to interpass heat input. The intricate physical shape of FZ and HAZ for X groove configuration possibly contributes to the lower transverse tensile strength of welding. A favorably increased hardness and transverse tensile strength are associated with softer and finer ferritic and perlitic grains in FZ and less dendritic perlite structure in HAZ. The Widmanstatten ferrite has contributed to decreased tensile strength.

Additive manufacturing of TiC-based cermets: A detailed comparison with spark plasma sintered samples

The present work is a comparative study on the TiC-430 L ferritic stainless steel (FSS) cermets manufactured via two powder metallurgical processes, namely, conventional spark plasma sintering (SPS) and metal additive manufacturing (AM) process (laser powder-bed fusion process (LPBF)/selective laser melting (SLM)). The rescanning strategy has been used to preheat and melt the powder bed with different laser parameters during the SLM process to suppress the presence of residual thermal stress leading to the fabrication of cermets without cracks. The as-fabricated SPS samples (95 %) show a relatively lower density than the SLM-built parts (~98 %). A study of their mechanical properties such as hardness, compressive strength, and fracture toughness was conducted and discussed in detail. Further, the corrosion behavior of the fabricated cermets parts was evaluated in 3.5 wt% NaCl. The SLM-prepared specimens reveal finer microstructures and better mechanical properties (compressive strength and fracture toughness) due to the presence of fine microstructure. Furthermore, the corrosion current density of TiC-430 L fss-based cermets fabricated by SLM is approximately 270 times lower than that of cermets parts fabricated by SPS, indicating excellent corrosion resistance. On the other hand, the hardness shows an opposite trend, where the SPS samples show the maximum hardness as compared to the SLM counterparts due to the presence of hard and coarse TiC particles along with some metallic carbides formed during the SPS process. The results reveal that AM processes not only can fabricate cermets with intricate shapes but can also fabricate them with improved mechanical and corrosion properties.

Highly Processable Ionogels with Mechanical Robustness

AbstractCurrently, the increasing needs of conductive ionogels with intricate shapes and high processability by individual requirements of next‐generation flexible electronics constitute significant challenges. Here, the design of highly processable ionogels is reported with mechanical robustness by self‐assembly of a common triblock copolymer into a precursor in functional mixed ionic liquids (ILs) containing conductivity‐enhancing and polymerizable strength‐enhancing components. The subsequent in situ polymerization of the precursor forms physical‐co‐chemical cross‐linked networks, in which the entanglement between physical and chemical cross‐linked networks and microphase separation give rise to mechanical robustness of as‐fabricated ionogel. The viscosity of the self‐assembled precursor can be rationally tuned, which makes the fabrication process compatible with diverse technologies including inkjet printing, spray coating, and 3D printing. By virtue of highly processable capability of the designed ionogels, an auxetic‐structured ionogel can be easily generated using 3D printing, which exhibits greatly improved sensitivity and thus is able to monitor tiny deformations. This study that relies on designing functional mixed ILs as the dispersion phase rather than focusing on synthesizing new‐type polymers establishes a new route for versatile and programmable fabrication of high‐performance ionogels for broader applications.

Improving bonding strength between Ni/Cu/Ag coatings and MgTiO3 ceramic resonator by alumina thin-film grown by atomic layer deposition

A layer of nano-sized alumina thin-film was grown on MgTiO3 based ceramic resonator using atomic layer deposition (ALD) to improve the bonding between resonator and electroless plated and/or electroplated metal coatings. The hydroxylation of resonator surface ensures the strong bonding between alumina film and ceramic substrate, indicating by the bonding score to 10 from 0. However, it will not result in the degradation of the insertion loss of metalized resonators. The signal insertion loss of metalized ceramic resonator with alumina thin-film intermediate layer is significantly lower than that of resonators treated by traditional HF solution corrosion and/or laser scanning to achieve strong bonding between resonator and metalized coatings. It could be promising to metalize ceramic resonators with highly complex intricate geometric shape.

The Influence of Angled Electrodes on Various Characteristics in EDM Process - Review Article

Electric discharge machining (EDM) is considered one of the most energy-efficient production methods for the highly accurate processing of any electrically conductive materials, regardless of mechanical characteristics. EDM is a non-contact method used in a diverse range of industries, including aerospace, industrial, instruments, molds and dies, and medical tools, particularly for hard materials with simple or intricate geometries and shapes. This review investigated EDM research in process, material, operational parameter selection, the influence on outputs, numerous process varieties, and innovative strategies to improve performance. The present study presented an overview of the EDM process with different angled electrode geometry, optimization, and modeling of method parameters, and the effect of parameters such as material removal rate (MRR), pulse shape, and surface roughness. This review (1) organized the published literature in a specific way, with an emphasis on both theoretical and experimental findings investigations to enhance the process performance, such as the rate of material removal and quality of surface, among others, and tool wear; (2) investigated assessment methods and procedures used to evaluate process circumstances; and (3) examined the EDM improvements and predicted future trends study. The article's conclusion section extracts specific points and gaps in each part. As a result, the article is straightforward to comprehend and incredibly beneficial to the scientific community.

Using data mining techniques deep analysis and theoretical investigation of COVID-19 pandemic

This study uses K-Means Clustering to analyze Corona-Virus Diseases (Covid-19). Data mining in medicine has generated novel approaches to examine diseases. Coronavirus is difficult to treat because of its intricate structure, shape, and texture. Due to data mining improvements, the K-Means approach has been developed for evaluating covid-19. Observe the outbreak's evolution, including its peak, and containment measures. A basic K-Means model is used to simulate Coronavirus's prevalence in Iraq. Pandemic-prevention efforts may slow its spread. If inhibition grows to 50%, Iraq will have 500,000 patients by year's end. If precautions were halved, the number would top 1 million. If we abandon all measures, the sickness will worsen. In that case, 55% of the population may be affected by the end of the month. This number will drop after September.

Enlarged rete pegs with excessive accumulation of melanosomes leading to darker aging spots revealed by histomorphological measurements of internal structures of the epidermis.

Various histological studies of facial pigmented spot sites such as solar lentigo have been reported, but few studies have used quantitative indices by histomorphometric analysis of the internal structure of pigmented spot sites using non-invasive methods. In the present study, to quantitatively elucidate morphological changes in the epidermis in male, darker-pigmented spots and female, light-pigmented spots, indices that characterize the internal structure of the epidermis in pigmented spot sites were measured using in vivo confocal laser scanning microscopy (CLSM). The darkness of pigmented spots on the cheeks of 69 women and 43 men was analysed using image analysis software. The L* value was calculated from RGB values obtained from facial images. The internal structures of pigmented spots on the cheeks of 13 subjects were observed by CLSM. Various parameters were measured using CLSM images from the surface of the stratum corneum to the bottom of the dermal papillae, including the thickness of the epidermis, melanosome content, and shape of the dermal papillae. Mean ΔL* values between pigmented spots and non-pigmented areas of male subjects were significantly increased in the 40s and 50s compared with those of female subjects. Conspicuous pigmented spots increased in the 40s in male subjects and the 50s in female subjects. In CLSM observations, significant increases in the thickness of the epidermis and melanosome content were confirmed in pigmented spots compared with surrounding non-pigmented areas. In particular, melanosome content in the male subject group with dark-coloured pigmented spots increased significantly to about eight times that of non-pigmented areas, and more than double that of the male subject group with light-coloured pigmented spots. From the measurements of quantitative parameters, morphological changes in the epidermis were clearly related to the surface colour tone of pigmented spots. Darker pigmented spot sites tended to show longer rete pegs in the epidermis. Accumulation of melanosomes in epidermal basal cells could be considered to increase with the degree of elongation of rete pegs at pigmented spot sites and, thus, induce darker pigmented spots.

Cell Encapsulation and 3D Bioprinting for Therapeutic Cell Transplantation.

The promise of cell therapy has been augmented by introducing biomaterials, where intricate scaffold shapes are fabricated to accommodate the cells within. In this review, we first discuss cell encapsulation and the promising potential of biomaterials to overcome challenges associated with cell therapy, particularly cellular function and longevity. More specifically, cell therapies in the context of autoimmune disorders, neurodegenerative diseases, and cancer are reviewed from the perspectives of preclinical findings as well as available clinical data. Next, techniques to fabricate cell-biomaterials constructs, focusing on emerging 3D bioprinting technologies, will be reviewed. 3D bioprinting is an advancing field that enables fabricating complex, interconnected, and consistent cell-based constructs capable of scaling up highly reproducible cell-biomaterials platforms with high precision. It is expected that 3D bioprinting devices will expand and become more precise, scalable, and appropriate for clinical manufacturing. Rather than one printer fits all, seeing more application-specific printer types, such as a bioprinter for bone tissue fabrication, which would be different from a bioprinter for skin tissue fabrication, is anticipated in the future.

Perspectives, analyses, and progress in additive manufacturing of food

Additive manufacturing techniques involve various steps and processes to create intricate shapes using edible or non-edible materials. This unique technology relies upon layer-by-layer operation to create an object that is pre-designed and coded with the help of specific software. The major challenges of three-dimensional printing that heavily depend on the material properties and machine capabilities are the ability to get a designed shape with high precision and accuracy, printing speed, and scalability. A critical review discussing the technology implementation from the perspectives of the food industry trends is of great interest, especially to industry professionals and academia. Adapting the technology in the food sector requires a critical view to overcoming technical barriers, which account for the food industry needs and current global challenges. In this regard, the relevant process parameters, the perspectives on food processing and engineering, and the nutritional aspects and culinary practices are considered. This review article discusses the current progress of additive manufacturing of food, the perspectives related to the food industry, and rheology as a tool where nonlinear behaviors are also included to unlock the analysis requirements for specific food groups for broader applications. The rheological methods for the characterization of food inks used in additive manufacturing technologies are critically reviewed, and key parameters are proposed.

Estimation of the Urban Temperature Reduction Effect in Low-rise Residential Areas using CFD Simulation based on the Shape of the Green Space

Purpose: Rapid urbanization has exacerbated the influence of the urban heat island effect in existing cities, particularly, in low-rise and densely-populated areas. Accordingly, small urban green spaces have been employed to lower the temperatures in urban areas and improve the quality of life. However, the current research on the quantitative analysis of the size and shape of urban green spaces, which maximize the temperature-reducing effect, is insufficient. Therefore, a quantitative analysis was performed in this study to determine the impact of the shape of an urban green space on the cooling effect of vegetation and range of impacts based on three elements: the area, perimeter, and shape index of the urban green space. Method: A computational fluid dynamics (CFD) simulation was performed and used to analyze the impact of the shape of the urban green space on the temperature-reducing effect and range of impacts by examining eighteen urban green spaces in three target areas. To this end, programs such as STAR-CCM+ and GIS were employed. Results: The analysis results show a meaningful relationship between the green space area and range of the cooling effect of the vegetation, and indicate the importance of the perimeter of the vegetation in reducing the temperature of the central and surrounding areas of the urban green space. Moreover, although the shape index is not a decisive factor, slender and intricate shapes were found to have a higher cooling effect for a short distance. Therefore, this study contributes to the establishment of a guideline for the development of a pleasant environment in existing cities.

Recruiting Unicellular Algae for the Mass Production of Nanostructured Perovskites.

Functional capacities of lead halide perovskites are strongly dependent on their morphology, crystallographic texture, and internal ultrastructure on the nano- and the meso-scale. In the last decade, significant efforts are directed towards the development of novel synthesis routes that would overcome the morphological constraints provided by the physical and crystallographic properties of these materials. In contrast, various living organisms, such as unicellular algae, have the ability to mold biogenic crystals into a vast variety of intricate nano-architectured shapes while keeping their single crystalline nature. Here, using the cell wall of the dinoflagellate L. granifera as a model, sustainably harvested biogenic calcite is successfully transformed into nano-structured perovskites. Three variants of lead halide perovskites CH3 NH3 PbX3 are generated with X = Cl- , Br- and I- ; exhibiting emission peak-wavelength ranging from blue, to green, to near-infrared, respectively. The approach can be used for the mass production of nano-architectured perovskites with desired morphological, textural and, consequently, physical properties exploiting the numerous templates provided by calcite forming unicellular organisms.

A Systematic Review of Factors Affecting the Process Parameters and Various Measurement Techniques in Forging Processes

Forging is a primary manufacturing process used in several manufacturing industries. Aircraft and automobile industries are manufacturing products with high‐dimensional accuracy and quality that are highly precise or near the required shape. Customers require products that are free of cracks and fulfill their functional requirements. This leads to the advancement of the forging process due to its ability to form complicated and intricate shapes. Herein, a detailed review of the aspects of forging is given in which the optimization of factors like preform design, forging conditions, workpiece dimensions, die design, lubricant properties, and thermal treatment parameters are discussed, enhancing the tool life and forging quality of the product. The selection of die‐forging tool material and methods for enhancing the surface quality of forged products are also reviewed. The article also presents methods for measurement of forging quality, tool life, machine effectiveness, forging image acquisition, and forging parameters, which can significantly reduce the risk of error at every step of the forging process. This review serves as a reference for researchers to increase production rate, enhance the effectiveness of measurement system, and improve the quality of forged products with technological advancement.

Parametric and heat affected zone study on CO2 laser cutting of acrylic

Laser cutting is a non-contact machining employed for producing small, intricate shapes. The acrylic materials are widely used in many applications. The parametric and heat affected zone study of acrylic materials by using CO2 laser machining is attempted in this research to evaluate the process variables, laser scanning speed, current, and nozzle-work material gap.•Research result indicate that the higher the current and the higher the cutting speed, result in higher the material removal rate•Other parameter such as current and nozzle, work material gap are also significant impact on the cutting process of the acrylic material.•In addition, heat affect zone increase with laser scanning speed.

Deep Hierarchical Pyramid Network With High- Frequency -Aware Differential Architecture for Super-Resolution Mapping

Super-resolution mapping (SRM) is a way to solve the mixed pixel problem in urban land use/land cover caused by the limited spatial-resolving ability of satellite sensors, through resolution enhancement of the classification map. Recently, deep learning based super-resolution mapping (DLSM) networks have been boomed, which can automatically learn a mapping pattern from low-resolution (LR) image to high-resolution (HR) land cover distribution to alleviate mixed pixel problem. However, the urban compositions like buildings, trees and roads, exhibit a multi-scale distribution with different size or orientation, which makes the traditional single-scale DLSM failed for an appropriate recognition. Besides, the urban compositions also show significant spatial heterogeneity with irregular distribution and intricate morphological shape, which are difficult to learn by simple convolutional layer. Therefore, it is necessary to explore the cue of these distribution characteristic to constrain the learning behavior of the network for better detail restoration. In this paper, a super-resolution mapping method based on deep hierarchical pyramid network with high-frequency-aware differential architecture (HiSMNet) is proposed, which establishes a hierarchical pyramid architecture to achieve explicit multi-scale supervision of the feature map, and prompt the network to learn a multi-scale representation. Besides, a differential architecture is designed to enforce the network to intensify the learning of the high-frequency details. The validation experiments demonstrate that HiSMNet achieves superior performances in detail delineation, and outperformed the state-of-the-art DLSM models by up to 10% in terms of overall accuracy.

Advanced Casting Techniques for Complex-Shaped Components: Design, Simulation and Process Control

The advancement of manufacturing technology has resulted in an increasing need for detailed, lightweight, and high-performance components with complicated geometries across many sectors. The emergence of advanced casting processes has been crucial in addressing these needs, as they provide the potential to manufacture components with complex geometries, enhanced mechanical characteristics, and minimised material wastage. The present study delves into the intricate domain of advanced casting processes, with a specific emphasis on the areas of design, simulation, and process control. The design of components with intricate shapes poses difficulties that conventional casting techniques encounter difficulties in surmounting. Simulation methods are crucial for accurately predicting the solidification and flow characteristics in casting processes, as this is essential for the production of components without any defects. Sophisticated simulation technologies, like as computational fluid dynamics (CFD) and finite element analysis (FEA), are utilised in advanced casting processes to model and analyse the intricate thermal and fluid dynamics phenomena that transpire during the casting process. This research provides an in-depth analysis of the role of simulations in enhancing the comprehension of solidification patterns, the identification of probable faults, and the optimisation of gating and riser designs to improve the overall quality of castings.

Design, fabrication, mechanical, and in vitro evaluation of 3D printed ZrO2 reinforced polylactide scaffolds through fused deposition modeling

FDM approach to build defect-free and intricate shapes of 3D printed ZrO2 based PLA composites.

"ИГРА ПРИРОДЫ": РАКОВИНА КАК ПЛАСТИЧЕСКИЙ МОТИВ В ДРЕВНЕГРЕЧЕСКОМ ИСКУССТВЕ

In this article, I trace the various ways Ancient Greek artisans used seashell-motifs, and how they interpreted these natural forms in artistic contexts. The reason for the popularity of seashells lies in their visual and haptic variety, their wealth of association, and the device of something secret hidden under the hard outer shell. I examine three possible variants of the motif’s treatment in relief and volume: the shell-container as part of a vessel, the shell as an independent container, the shell as a sculpted motif on a vessel. Of particular interest are the vases where the integration of shell and vessel is especially marked, such as plastic aryballoi, lekythoi and other types (often with the inclusion of mythological subjects, such as the birth of Aphrodite). Terracotta and metal pyxides are also considered. Alongside these, I examine the rare “marble shells”, stone vessels carved in the intricate shape of “pelican’s foot” shells.

Review of quality issues and mitigation strategies for metal powder bed fusion

PurposeSelective laser melting and electron beam melting processes are well-known for the additive manufacturing of metal parts. Metal powder bed fusion (MPBF) is a common term for them. The MPBF process can empower the manufacturing of intricate shapes by reducing the use of special tools, shortening the supply chain and allowing small batches. However, the MPBF process suffers from many quality issues. In literature, several works are recorded for qualification of the MPBF part. The purpose of this study is to recollect those works done for quality control and report their helpful findings for further research and development.Design/methodology/approachA systematic literature review was conducted to highlight the major quality issues in the MPBF process and its root causes. Further, the works reported in the literature for mitigation of these issues are classified and discussed in five categories: experimental investigation, finite element method-based numerical models, physics-based analytical models, in-situ control using artificial intelligence (AI) and machine learning (ML) methods and statistical approaches. A comparison is also prepared among these strategies based on their suitability and limitations. Additionally, improvements in MPBF printers are pointed out to enhance the part quality.FindingsAnalytical models require less computational time to simulate the MPBF process and need a smaller number of experiments to confirm the results. They can be used as an efficient process parameter planning tool to print metal parts for noncritical applications. The AI-ML based quality control is also suitable for MPBF processes as it can control many processing parameters that may affect the quality of the MPBF part. Moreover, capabilities of MPBF printers like thinner layer thickness, smaller beam diameter, multiple lasers and high build temperature range can help in quality control.Research limitations/implicationsThis study converts the piecemeal data on MPBF part qualification methods into interesting information and presents it in tabular form under each strategy. This tabular information provides the basis for further quality improvement efforts in the MPBF process.Originality/valueThis study references researchers and practitioners on recent quality control efforts and their significant findings for a better quality of MPBF part.