Plastic Shell Research Articles

Knock-on deuteron imaging for diagnosing the morphology of an ICF implosion at OMEGA

Knock-on deuteron imaging is a new diagnostic technique that is being implemented at the OMEGA laser facility to diagnose the morphology of an inertial confinement fusion (ICF) implosion. It utilizes the fact that some of the neutrons from deuterium–tritium (DT)-fusion reactions generated in the central hot-spot of an ICF implosion elastically scatter deuterons as they traverse the surrounding shell layer. The energy of these “knock-on” deuterons depends on the scattering angle, where the most energetic deuterons are forward-scattered and probe the shape of the central hot-spot, while lower-energy deuterons are made by side-scattering or slowing down in the fuel and carry information about the distribution of the dense DT-fuel layer surrounding the hot-spot. The first proof-of-concept tests have been conducted successfully. In these tests, three penumbral imagers with different views on an implosion recorded deuterons scattered from the dense shell of DT-gas-filled deuterated plastic shell implosions with prescribed offsets. Data from these experiments are presented here, along with novel analysis techniques that iteratively reconstruct the deuteron source from the data. Reconstructed hot-spot and shell radii agree with 1D hydro simulations and indicate a P1 asymmetry in the direction of the offset. A comparison of coaxial deuteron and x-ray images suggests the presence of a mix between the hot-spot and shell on the order of 15 μm. This new diagnostic capability will allow us to study asymmetries in unprecedented detail at OMEGA.

SHORT REPORT OF FIRST EXPERIENCES IN STABILIZATION OF FINE ROAD SOILS WITH SHREDDED FACE MASKS IN ARGENTINA

In the world full of crises, also the rising demand for PPE suits and masks would lead to another wave of biomedical waste disposition crises. The disposal of thrown away wastes causes a serious issue as the waste are most of the time are non- biodegradable and these are also not fit for incineration. Soil stabilization improves the engineering properties of the weak soil, by proper compaction and additional materials such as lime, concrete, but these materials are becoming expensive day by day, hence plastic by the composition of egg shell powder could enhance the properties and can be a sustainable replacement for lime, concrete, etc. as stabilizer. Through much experimental investigation it has been showed that plastic and egg shell powder can be used as an effective stabilizer with encountering waste disposal problem as well, along with the economical solution for stabilizing weak soil. This PPE stripes/shredding are known for its high strength, low cost, significantly less dangerous for the environment. The combined effect of PPE stripes/shredding along with egg shell powder can enhance engineering properties of soil.

Numerical simulation and optimization of heat dissipation structure for high power insulated gate bipolar transistor (IGBT)

With the increasing integration level of IGBT components, heat dissipation capacity determines whether its working state is stable. The third-generation semiconductor chips are expected to be made of SiC or GaN materials, with lower power loss and higher thermostability. Currently, the widely used backplane heat dissipation schemes cannot meet the heat dissipation requirements of high-power IGBT modules. In this study, an aluminium alloy shell with an AlN column is proposed to replace the traditional plastic shell to further improve the heat dissipation of IGBT devices. 180°C is set as the expected maximum temperature of the module, and finite element modelling and analysis of the heat dissipation structure of the IGBT device is carried out. Four types of design schemes are compared and the heat dissipation structure is optimized. AlN heat-transfer blocks and Ag sintering are introduced to realise the novel design. The results show that traditional single-side heat dissipation can not meet the requirements. The improved double-side dissipation scheme meets the requirement when the heat sink fin height is more than 15mm. And the optimized heat sink shall have 14 fins of 20mm in height. The results of this study can provide a reference for the thermal management and design of high-power third-generation semiconductor devices.

Vacuum-Formed 3D Printed Electronics: Fabrication of Thin, Rigid and Free-Form Interactive Surfaces

Vacuum-forming is a common manufacturing technique for constructing thin plastic shell products by pressing heated plastic sheets onto a mold using atmospheric pressure. Vacuum-forming is ubiquitous in packaging and casing products in the industry, spanning fast moving consumer goods to connected devices. Integrating advanced functionality, which may include sensing, computation and communication, within thin structures is desirable for various next-generation interactive devices. Hybrid additive manufacturing techniques like thermoforming are becoming popular for prototyping freeform surfaces owing to their design flexibility, speed and cost-effectiveness. This paper presents a new hybrid method for constructing thin, rigid and free-form interconnected surfaces via fused deposition modelling (FDM) 3D printing and vacuum-forming that builds on recent advances in thermoforming circuits. 3D printing the sheet material allows for the embedding of conductive traces within thin layers of the substrate, which can be vacuum-formed but remain conductive and insulated. This is an unexplored fabrication technique within the context of designing and manufacturing connected things. In addition to explaining the method, this paper characterizes the behavior of vacuum-formed 3D printed sheets, analyses the electrical performance of printed traces after vacuum-forming, and showcases a range of sample artefacts constructed using the technique. In addition, the paper describes a new design interface for designing conformal interconnects that allows designers to draw conductive patterns in 3D and export pre-distorted sheet models ready to be printed.

Emission phases of implosion sources for x-ray absorption fine structure spectroscopy

At the Laboratory for Laser Energetics' Omega Laser Facility, thin plastic shells were directly driven with ∼20 kJ resulting in a time-integrated x-ray yield of ∼1012 ph/eV/sr at 7 keV. Using temporally, spatially, and spectrally discriminating diagnostics, three x-ray emission phases were identified: corona emission produced by the laser ablation of the shell, core stagnation, and afterglow emission due to the expanding hot material after stagnation. The newly measured corona and afterglow emission phases account for ∼25% of the total x-ray signal and produce x-ray emission at a different time or larger radius than previously considered. The resulting implications of this additional emission for x-ray absorption fine structure spectroscopy are discussed. Finally, improvements to the laser drive intensity and uniformity produced a factor-of-2 increase in total x-ray emission while decreasing the size of the stagnated core.

Building blend from recycling acrylonitrile–butadiene–styrene and high impact-resistance polystyrene through dextro-glucose

As the constantly upgrading of electronic product, and the number of plastic shells of waste electronic products is also increasing sharply. Acrylonitrile-butadiene-styrene (ABS) and high impact-resistance polystyrene (HIPS) account for a large part, but ABS and HIPS not only have similar densities, but also have similar chemical properties, which make it difficult to separate ABS and HIPS. Therefore, the preparation of composite materials by blending waste ABS and waste HIPS is an important method to realize the high-value reuse of waste ABS and waste HIPS. In this work, d-glucose (d-Glucose) was used as a compatibilizing agent for the first time to modify recycling acrylonitrile-butadiene-styrene (rABS) and recycling high impact-resistance polystyrene (rHIPS) by melt blending. The d-Glucose has multiple hydroxyl groups, and it can react with the aging groups of butadiene in rABS/rHIPS to form ester groups, repairs broken molecular chains and improves compatibility between two phases to enhance the mechanical properties. The results show that the impact strength, tensile strength, flexural strength and storage modulus of the resulted rABS/rHIPS blend have been enhanced. When added the number of d-Glucose accounts for 5 wt% of the total components, the notched impact strength reaches 9.67 kJ/m2, which is 128% higher than that before modification. Compared with other researchers, not only the impact strength is greatly improved, but also the tensile strength and flexural strength are improved. The mechanisms for the enhancement is studied and discussed.

Personalized 3D-printed anthropomorphic whole-body phantom irradiated by protons, photons, and neutrons

The objective of this study was to confirm the feasibility of three-dimensionally-printed (3D-printed), personalized whole-body anthropomorphic phantoms for radiation dose measurements in a variety of charged and uncharged particle radiation fields. We 3D-printed a personalized whole-body phantom of an adult female with a height of 154.8 cm, mass of 90.7 kg, and body mass index of 37.8 kg/m2. The phantom comprised of a hollow plastic shell filled with water and included a watertight access conduit for positioning dosimeters. It is compatible with a wide variety of radiation dosimeters, including ionization chambers that are suitable for uncharged and charged particles. Its mass was 6.8 kg empty and 98 kg when filled with water. Watertightness and mechanical robustness were confirmed after multiple experiments and transportations between institutions. The phantom was irradiated to the cranium with therapeutic beams of 170-MeV protons, 6-MV photons, and fast neutrons. Radiation absorbed dose was measured from the cranium to the pelvis along the longitudinal central axis of the phantom. The dose measurements were made using established dosimetry protocols and well-characterized instruments. For the therapeutic environments considered in this study, stray radiation from intracranial treatment beams was the lowest for proton therapy, intermediate for photon therapy, and highest for neutron therapy. An illustrative example set of measurements at the location of the thyroid for a square field of 5.3 cm per side resulted in 0.09, 0.59, and 1.93 cGy/Gy from proton, photon, and neutron beams, respectively. In this study, we found that 3D-printed personalized phantoms are feasible, inherently reproducible, and well-suited for therapeutic radiation measurements. The measurement methodologies we developed enabled the direct comparison of radiation exposures from neutron, proton, and photon beam irradiations.

Pollution characteristics and source identification of PBDEs in public transport microenvironments

Public transport microenvironments easily accumulate pollutants due to high airtightness and poor circulation. To investigate and analyze the pollution levels and sources of polybrominated diphenyl ethers (PBDEs), air and dust samples were collected from hybrid buses, electric buses and subways in Hangzhou, China. The components of six priority control PBDE congeners (BDE-28, -47, -99, -100, -153, and -209) were analyzed. The average concentrations of Σ6PBDEs in the air and dust samples were 625.38 pg/m3 and 1200.58 ng/g from hybrid buses; 747.46 pg/m3 and 1160.07 ng/g from electric buses; and 407.57 pg/m3 and 925.93 ng/g from subways, respectively. Decabromodiphenyl ether (BDE-209) was the main proportion of Σ6PBDEs in the air and dust samples. Several types of materials were collected from the interior as samples to investigate pollutant sources. Using principal component analysis (PCA), it was found that seat cover, polyvinyl chloride (PVC) plastic, rubber, and wire shells were the primary sources. Compared with the reference dose of several PBDE congeners proposed by the U.S. Environmental Protection Agency (US EPA), the exposure level of the population in public transport microenvironments to PBDEs was estimated to be low; however, the potential danger cannot be ignored.

Position/Force Visual-Sensing-Based Robotic Sheet-Like Peg-in-Hole Assembly

This article deals with a sheet-like peg-in-hole robotic assembly task which is usually done in manual operation. Thin-walled deformable objects will introduce some special uncertainties in robotic peg-in-hole assembly, which may make this kind of robotic assembly difficult. To deal with this issue, three four-phase selective compliance articulated robot arm (SCARA)-based peg-in-hole assembly strategies which imitate manual assembly with a hybrid switching force/position control scheme are proposed. Both position/force visual sensing methods are proposed based on a single-lens imaging system in an eye-to-hand configuration, respectively. Based on the developed visual sensing techniques, an iterative learning control (ILC) scheme is designed to approximate the synchronous position control between a SCARA robot and a two-degree of freedom (DoF) hybrid compliant gripper. The experiments are implemented on our built-up SCARA-based robotic peg-in-hole (peg: electrode ear, hole: plastic shell) assembly platform. The results indicate that the visual force sensing nonlinearity is about 3% at the full range, and the proposed robotic assembly strategies are suited to this kind of peg-in-hole assembly from industrial scenarios.

A Multi-Frequency 3D Printed Hand Phantom for Electromagnetic Measurements.

It has been shown that the presence of a hand holding a wireless handset (cell phone) can influence antenna efficiency and the measurement of specific absorption rate (SAR) and electromagnetic compatibility. Head phantoms, used in handset compliance testing to estimate SAR in the head, have achieved low cost and multi-frequency use. Head phantoms typically consist of a thin plastic shell, open on the top, holding a tissue simulating fluid. The specific simulant fluid used is determined by the radio frequency of the test. IEC 62209-1 has recipes, using safe nontoxic materials, for all the required frequency bands. Thus, head phantoms can be reused at different frequencies simply by changing the tissue simulating fluid. However, standards have not adopted the use of hand phantoms because SAR limits in limbs are less restrictive than the head, the tissue depth in a hand is insufficient to make accurate measurements with current electric field probes, and the cost of a solid hand phantom is limited to a single frequency band. Our goal was to determine whether 3D printing techniques would allow the construction of a hand phantom with the same utility as existing head phantoms. We developed this phantom based on computer simulations to determine how much human anatomy needed to be included in the phantom to obtain results consistent with actual use. Electric field scans of a handset alone, and held by the hand phantom, were performed. Comparison of handset scans using the phantom and human subjects was planned, but not performed due to Covid-19 restrictions and subsequent changes in priorities. We feel a fluid-filled 3D printed hand phantom is viable and practical. The 3D print files are available on GitHub.

Utilization of Waste Materials in Structural Members: A Review

More development approaches more litter, more litter makes natural worries of harmful danger. The use of litter materials for future new products would be a cost-effective and realistic solution to this problem, reducing the tremendous pressure on the country's landfills. Reusing litter as development materials save regular assets, saves energy, diminishes strong waste, brings down air and water contamination, and brings down ozone-depleting substance outflows. The development area can start to recognize and benefit from the advantages of using trash and repurposed materials. Acceptable litter, reused and reusable materials, and strategies have all been explored in numerous studies. Due to the scarcity and rising expense of raw materials, the use of shattered tiles, bones, glass, plastic, seeds, and coconut shell in structural components is becoming more popular. Compression, water absorption, hardness, shape, size, and soundness of structural elements made of litter material will be tested in this study. A comparison of all test findings of structural elements formed of litter materials with conventional structural members will be done to break down present practices in the building industry in regard to litter use and reused materials. This study provides an early knowledge of the practice's current strengths and flaws in order to assist the construction industry in formulating appropriate policies governing the use of trash and reused materials as development materials.

Discussion on Surface Resistance Test Requirements of Plastic Shell Parts of Explosion-proof Electrical Appliances for Coal Mine

Discussion on Surface Resistance Test Requirements of Plastic Shell Parts of Explosion-proof Electrical Appliances for Coal Mine

유럽과 중남미 카니발 복식 연구

My research investigates global carnival costumes to see how they appear similar or different across countries, paying particular attention to Europe and Latin America, dominant regions in the world of carnival. I explore costumes from 24 European and Latin American carnivals which are designated by the UNESCO and/or nominated by the USA Today along with corresponding literature review. The results obtained may be summarized as follows. There is a strong correlation between the purpose of a carnival and the styles of costumes worn at it. Carnivals of religious relevance in Europe prefer conservative traditional costumes in their rituals. While carnivals for pleasure in Latin America feature innovative or sensual costumes. Femininity has been strengthened in Latin America, while gender status varies across carnivals and carnival costumes. Latin American carnival costumes, which have become popular and commercialized, feature materials and forms which are substantially diversified. They combine cloth with plastic beads, feathers, sequins, colorful ribbons, glass mirrors, horns and shells to create a dazzling spectacle. Even grass, leaves, raffia, flowers, beads, fur, animal hides, feathers, and cotton are used in carnival costumes, while materials are replaced with synthetic substitutes for reasons of cost and mass production. As the number of local carnivals increases in Korea, research into carnival costumes should be expanded to develop industry, promote social cohesion, and advance education.

Stabilization of Soil by the Composition of Eggshell Powder and Shredded PPE Kit

In the world full of crises, also the rising demand for PPE suits and masks would lead to another wave of biomedical waste disposition crises. The disposal of thrown away wastes causes a serious issue as the waste are most of the time are non- biodegradable and these are also not fit for incineration. Soil stabilization improves the engineering properties of the weak soil, by proper compaction and additional materials such as lime, concrete, but these materials are becoming expensive day by day, hence plastic by the composition of egg shell powder could enhance the properties and can be a sustainable replacement for lime, concrete, etc. as stabilizer. Through much experimental investigation it has been showed that plastic and egg shell powder can be used as an effective stabilizer with encountering waste disposal problem as well, along with the economical solution for stabilizing weak soil. This PPE stripes/shredding are known for its high strength, low cost, significantly less dangerous for the environment. The combined effect of PPE stripes/shredding along with egg shell powder can enhance engineering properties of soil.

A simulation of the thermal environment of a plastic body of a new type of launch vehicle at the atmospheric phase of the trajectory

PurposeLeading developers and providers in the modern space launch market note a splash in the development of ultralight launch vehicle (LV), driven by the growing demand for small satellites for large constellations in low Earth orbits. One of the promising ways to solve the problem of the quick launch of such satellites is to use a new type of ultralight launch vehicle with a plastic body. The project of such a launch vehicle was proposed by Oles Honchar Dnipro National University (Ukraine). Along with that, there is a need for appropriate research studies on the thermal resistance of the plastic shell, as the physical, mechanical and thermophysical characteristics of polymers significantly differ from traditional aerospace materials. The purpose of this study is to validate the design and ballistic parameters of such a launch vehicle in terms of providing an acceptable thermal environment at the atmospheric phase of the trajectory.Design/methodology/approachThe workability of a new type of propulsion system is being investigated experimentally in bench conditions. To study the process of aerodynamic heating of a plastic shell, numerical modeling based on the integration of the flight dynamics and heat transfer equations is used.FindingsBrief information about the design of a new type of ultra-light autophage launch vehicle with a plastic body is presented. A mathematical model for the movement of the launch vehicle at the atmospheric phase of the trajectory, and for the heating of the polyethylene body of the launch vehicle, taking into account the dynamic change in the atmospheric parameters is proposed. The influence of the motion trajectory on the thermal environment of the rocket body is investigated, rational motion trajectories and corresponding permissible g-loads are determined.Originality/valueThe fundamental possibility of using plastic (polyethylene) as a structural material and fuel for bodies of a new type of ultralight launch vehicles has been substantiated. It is shown that to ensure acceptable thermal conditions of a plastic body, it is necessary to use thermal insulation. It is proposed to use a polymeric Teflon coating as such thermal insulation. The results are important for the development of technologies for launching small satellites into orbit, as the use of plastic as the main structural material of the rocket body will significantly reduce the launch cost.

Towards a Microwave Imaging System for Continuous Monitoring of Liver Tumor Ablation: Design and In Silico Validation of an Experimental Setup.

Liver cancer is one of the most common liver malignancies worldwide. Thermal ablation has been recognized as a promising method for its treatment, with a significant impact on clinical practice. However, the treatment’s effectiveness is heavily dependent on the experience of the clinician and would improve if paired with an image-guidance device for treatment monitoring. Conventional imaging modalities, such as computed tomography, ultrasound, and magnetic resonance imaging, show some disadvantages, motivating interest in alternative technologies. In this framework, microwave imaging was recently proposed as a potential candidate, being capable of implementing real-time monitoring by means of low-cost and portable devices. In this work, the in silico assessment of a microwave imaging device specifically designed for liver ablation monitoring is presented. To this end, an imaging experiment involving eight Vivaldi antennas in an array configuration and a practically realizable liver phantom mimicking the evolving treatment was simulated. In particular, since the actual phantom will be realized by 3D printing technology, the effect of the plastic shells containing tissues mimicking materials was investigated and discussed. The outcomes of this study confirm that the presence of printing materials does not impair the significance of the experiments and that the designed device is capable of providing 3D images of the ablated region conveying information on its extent and evolution. Moreover, the observed results suggest possible improvements to the system, paving the way for the next stage in which the device will be implemented and experimentally assessed in the same conditions as those simulated in this study.

Fatigue Life of a Structurally Like Sample of a Fuselage Panel with an Aluminum–Glass-Reinforced Plastic Shell

Fatigue Life of a Structurally Like Sample of a Fuselage Panel with an Aluminum–Glass-Reinforced Plastic Shell

Free vibration analysis of laminated composite hybrid and GFRP shells based on higher order zigzag theory with experimental validation

Free vibration response behavior of laminated composite hybrid and Glass Fiber Reinforced Plastic (GFRP) shells is analyzed using a modified higher order zigzag theory (HOZT). The laminated shell model is developed by considering the thickness co-ordinate to radius of curvature ratio (z/R) as well as zero shear conditions at free surfaces of the shell. The C0 finite element formulations with nine-noded quadrilateral isoparametric shell element having seven degrees of freedom per node are adopted to compute the natural frequency of the shells. The hybrid laminate is modeled by placing carbon fibers in the outermost layers and glass fibers in the rest to improve the flexural behavior of the shell. Experimental studies are performed to find out the mechanical properties of hybrid and GFRP laminates such as Young modulus, shear modulus and poison's ratio. The experimental procedure of free vibration is carried out by Bruel & Kjaer (B&K) modal analysis instruments along with RT Pro modal analysis software and the results are compared with the theoretical findings. Moreover the present theoretical results have been examined by comparing with 2D solutions as well as 3D elasticity solutions available in the published literature to verify the accuracy of the present HOZT. An extensive parametric study on laminated composite hybrid and GFRP shells with various laminations is undertaken to investigate the effect of reinforcement scheme on the free vibration behavior of such laminated shells.

A comprehensive study on the combustion kinetic modeling of typical electronic plastic waste—television set (TV) plastic shell

ABSTRACT Electronic waste is the fastest growing waste stream and one of the most significant constituents is electronic plastics. In this study, the combustion kinetic of typical electronic plastic waste—television set (TV) plastic shell—was investigated using two basic kinetic methods. The reaction mechanism and kinetic compensation effect were probed as well. The thermogravimetric analysis (TGA) revealed that its degradation process can be divided into four stages, namely, reaction initiation stage (20–300 °C), major reaction stage (300–450 °C), minor reaction stage (450–600 °C), and reaction cessation stage (600–1,000 °C). The activation energy (E) were calculated and indicated that, the kinetic parameters from six model-free methods gradually decreased with α increasing from 0.1 to 0.35, and then slightly increased. The Flynn--Wall--Ozawa (FWO) method was more reliable and E values decreased from 155.0 to 147.51 kJ/mol with α range of 0.1–0.35, then gradually increased to 165.21 kJ/mol. Within the Coats--Redfern method, the first-order (F1) model had higher coefficient of determination (R2) and comparable E values with that from FWO method. The result of kinetic compensation effect confirmed that the compensation effect existed between E and A during the plastic waste combustion. A linear relationship lnA = 0.183E-3.11 (R2 = 0.991) was obtained. The pre-exponential factors (A) were also determined as 7.67 × 1010 min−1 based on the F1 reaction model and FWO method. Implications: Municipal solid waste (MSW) is a complex mixture of different components and the plastic takes up a significant portion in total MSW. Understanding the combustion process of typical electronic plastic waste and further probing its combustion kinetic are significant. Through this study, it will be significant for the reactor designing and optimizing in practice.

Effectiveness of FRP strengthening on buckling characteristics of metallic cylindrical shells

Buckling performance of thin metallic shells can be enhanced by external wrapping of FRP composite layers. But the effectiveness and the extent of such FRP strengthening is influenced by the buckling characteristics of the metallic shell. This paper presents a detailed numerical study to bring out the changes in buckling behaviour and buckling modes of metallic cylindrical shells of different r/t ratios, exhibiting all varieties of buckling viz. elastic, axisymmetric plastic, and asymmetric plastic, due to changes in the hoop and longitudinal stiffness of the FRP wrap. The most general buckling behaviour of the FRP strengthened shells exhibiting elastic, pre-strain localization, post strain localization, axisymmetric buckle growth, and the asymmetric buckle growth stages are being brought out. Subsequently, the influence of parameters viz. r/t ratio, modulus and yield strength of the metallic shell, and the type and magnitude of the FRP strengthening on this general buckling behaviour are analysed. The results demonstrate that 1) the elastic buckling shells display a stepwise increase in load capacity with an increase in hoop modulus of the FRP wrap; 2) for the plastic buckling shells undergoing asymmetric buckling modes, a minimal increase in longitudinal stiffness of FRP wrap, just sufficient to reach the shells’ yield capacity, would lead to an optimal design; and 3) for the plastic buckling shells failing due to axi-symmetric bulging at their ends, the increase in longitudinal stiffness of FRP, increases both the yield capacity and the pre-strain localization stiffness, leading to a large increase in buckling capacity.