Journal articles: 'Polymer shield'

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Nurherdiana, Silvana Dwi. "Polymer Technology Outlook Study: Face Shields for Responding SARS-CoV2 Pandemic." International Journal of Eco-Innovation in Science and Engineering 2, no. 01 (July 7, 2021): 20–24. http://dx.doi.org/10.33005/ijeise.v2i01.38.

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The coronavirus disease 2019 (SARS-CoV2) has attracted most interest in current years due to the worst impact for the global public health. In this situation, the whole world requires wearing face shield and mask as the personal protective equipment, especially for medical personnel. Polymer technology have been introduced as a helping tool against SARS-CoV2 by producing healthcare product such as face shield as the first line of resistance due to it was cost effectiveness, sterile nature, versatility and easy to modify. This article clarifies the discussion about face shields in the polymer technology as the point of view and aims at providing a deeper understanding about polymer, polymeric material, synthesis methodology and its application for responding SARS-CoV2 pandemic in a form of face shields. The study of the synthesis route and methodology, chemical and physical properties of the polymer for face shields have also been described.

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Benhamou, S. M., M. Hamouni, and F. Ould-Kaddour. "Crossover Frequency and Transmission-Line Matrix Formalism of Electromagnetic Shielding Properties of Laminated Conductive Sheets." Advanced Electromagnetics 7, no. 2 (March 1, 2018): 28–35. http://dx.doi.org/10.7716/aem.v7i2.566.

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This paper proposes an approach to calculate the crossover frequency of each layer in the multilayered shield and subsequently that of structure constructed by n layers. This important frequency provides a useful approximation for field penetration in a conductor. It is used in a wide variety of calculations. It is in this context that a simplification of the transmission-line matrix formalism for laminated conductive sheets is done using this frequency. Two ranges of frequency are considered: lower and higher than the crossover frequency. Simples formulas and easy to use of the reflection loss, the internal reflection, the absorption loss and the electromagnetic shielding effectiveness of laminated shield are obtained. Analysis is carried out for the study of two shields: i) single shield of carbon nanotube polymer composites (CNTs), ii) multilayered shield constructed with Nickel–carbon nanotube polymer composites–Aluminum (Ni–CNTs–Al).

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Maity, Subhankar, and Arobindo Chatterjee. "Conductive polymer-based electro-conductive textile composites for electromagnetic interference shielding: A review." Journal of Industrial Textiles 47, no. 8 (September 19, 2016): 2228–52. http://dx.doi.org/10.1177/1528083716670310.

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This article reviews the preparation, development and characteristics of conductive polymer-based electro-conductive textile composites for electromagnetic interference shielding. Modification of ordinary textile materials in the form of electro-conductive composites makes them suitable for this purpose. Various metallic and non-metallic electro-conductive textiles have been explored here as the material for electromagnetic shielding. Different approaches of preparing textile electromagnetic shield have been described here. Recent advancements of application of conductive polymers in the field of textile electromagnetic shielding are described. Conductive polymer-coated textile materials showed superior electrical property as electromagnetic shield. Different methods of applications of conductive polymers onto textile surface are described here with their relative merits and demerits. Different conductive polymer-coated woven and nonwoven fabrics prepared by various researchers for electromagnetic shielding are taken into account. The effects of different process parameters of polymer processing on electromagnetic shielding are described.

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Kim, Seon-Chil. "Performance Evaluation According to Polymer Encapsulation Characteristics of Eco-Friendly Plastic Gamma-Ray Shield." Coatings 12, no. 11 (October 26, 2022): 1621. http://dx.doi.org/10.3390/coatings12111621.

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To eliminate the exposure of medical staff to radiopharmaceuticals during nuclear medicine tests, a new process technology was proposed for manufacturing gamma-ray shields used in nuclear medicine. In the case of manufacturing the existing gamma-ray shield, a method of increasing the content of the shielding material in the mixed material is used to improve the shielding performance. However, it is impossible to improve the shielding performance by simply increasing the content of the shielding material. Therefore, this study aims to present the optimal conditions for improving the miscibility between composite materials. Following the additional mixing of barium sulfate and bismuth oxide with tungsten, a syringe shield was developed via a plastic injection mold process. When tungsten was solely used or in combination with other shielding materials, polymer encapsulation occurred, and miscibility between composite materials was observed. Based on these results, the optimal conditions in terms of eco-friendly materials, economic feasibility, and improvement in shielding performance were determined. The findings of this study reveal that when tungsten and the polymers are combined, the polymer encapsulation is optimal, the particles are uniformly dispersed, and the shielding performance is significantly improved. With a 99mTc source, a 6.9% improvement in the shielding performance is achieved compared with the use of lead.

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Elzaki, Amin, and Ahmed Al-Ghamdi. "An Innovative Approach to Electromagnetic Radiation Shielding by Graphene: An Experimental Study." International Journal of Research and Review 9, no. 7 (July 19, 2022): 187–96. http://dx.doi.org/10.52403/ijrr.20220720.

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The need to use electromagnetic radiation in clinical practices indicates the defense from the electromagnetic radiation itself which have a destructive impact on the human tissue and brain. Therefore, the wearable aprons as electromagnetic shields are the protective gears required to enhance their blend and structure to attain effective shielding. The aprons that are made of textile materials are widely considering protecting from electromagnetic radiation. In this context, conventional textile-materials are not appropriate, but their adaptations, which are in the form of composites, are utilized. The contemporary literature contributed by the recent past research works has several methods of making textile electromagnetic radiation shield. Recent innovations of conductive polymer application in electromagnetic radiation shielding were considered. The treating of textile materials by conductive polymer displayed higher electrical property in the form of electromagnetic radiation shield. Protective mechanisms such as aprons of electromagnetic radiation shielding are essential for enhancing their blend and structure to attain effective radiation shielding. The carbon nanotube is deliberated as a productive polymer result for the electromagnetic radiation shielding. The review experiment aimed to discuss the possibility of using a graphene coat on the polymer composite of carbon nanotube and to improve the practical solution for shielding the protective aprons. The confines of a polymer composite of carbon nanotube attenuation stages are deliberated in this article. Keywords: Carbon Nanotube, Electromagnetic Radiation, Graphene.

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Kim, Seon-Chil. "Tungsten-Based Hybrid Composite Shield for Medical Radioisotope Defense." Materials 15, no. 4 (February 11, 2022): 1338. http://dx.doi.org/10.3390/ma15041338.

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The shielding performance of shielding clothing is typically improved by increasing the shielding material content, but this lowers the tensile strength of the material. The weight and wearability of the shielding suit are also adversely affected. Important considerations when developing shielding fabric are thickness and flexibility to allow the wearer sufficient mobility. Insufficient thickness lowers the shielding performance, whereas excessive thickness decreases the flexibility of the garment. This study aimed to develop a composite shield that reproduces the shielding performance and meets the flexibility of the process technology. The new shield was manufactured by combining two layers: the shielding fabric fabricated from tungsten wire and a shielding sheet produced by mixing a polymer (PDMS) with tungsten powder. These two shields were bonded to develop a double hybrid composite. Compared with the existing shielding sheet (produced from lead equivalent of 0.55 mmPb), the shielding performance of the hybrid composite shield improved by approximately 17% on average and the tensile strength was 53% higher. The hybrid composite shield has a thickness of 1.35 ± 0.02 mm and delivers the same shielding performance as the lead equivalent. The new hybrid composite shield offers higher wearer mobility while shielding against radiation exposure in medical institutions.

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Lim, Bryan, and Pei Jun Hong. "Sprayed-On Polymer as Concrete Spall Shield." Solid State Phenomena 136 (February 2008): 145–52. http://dx.doi.org/10.4028/www.scientific.net/ssp.136.145.

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Concrete when subjected to a blast loading from a close-in detonation will experience spalling due to formation of tension waves on the opposite face of the concrete panel. The spalled concrete may be ejected at high velocity causing undesirable effects to occupants. Tests using 1/2kg TNT blocks were conducted on 100mm thick concrete panels to study the effects of spalling and whether the spalled materials can be arrested using a sprayed-on polymeric coating. From the tests, it was observed that without the sprayed-on polymeric coating, extensive spalling occurred. However, with just a 3-4mm thick layer of sprayed-on polymer, the spalled materials were arrested and contained. Numerical models of the reinforced concrete slab were created using Autodyn 2D and the results of the simulation were compared to observations from the tests. There was good correlation between the test results and the simulation results as the size of the crater, both front and back, on the concrete slab were rather similar.

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Hintermayr, Verena A., Carola Lampe, Maximilian Löw, Janina Roemer, Willem Vanderlinden, Moritz Gramlich, Anton X. Böhm, et al. "Polymer Nanoreactors Shield Perovskite Nanocrystals from Degradation." Nano Letters 19, no. 8 (July 19, 2019): 4928–33. http://dx.doi.org/10.1021/acs.nanolett.9b00982.

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Biswas, Sourav, Tanyaradzwa S. Muzata, Beate Krause, Piotr Rzeczkowski, Petra Pötschke, and Suryasarathi Bose. "Does the Type of Polymer and Carbon Nanotube Structure Control the Electromagnetic Shielding in Melt-Mixed Polymer Nanocomposites?" Journal of Composites Science 4, no. 1 (January 15, 2020): 9. http://dx.doi.org/10.3390/jcs4010009.

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A suitable polymer matrix and well dispersed conducting fillers forming an electrically conducting network are the prime requisites for modern age electromagnetic shield designing. An effective polymer-based shield material is designed that can attenuate 99.9% of incident electromagnetic (EM) radiation at a minimum thickness of <0.5 mm. This is accomplished by the choice of a suitable partially crystalline polymer matrix while comparing non-polar polypropylene (PP) with polar polyvinylidene fluoride (PVDF) and a best suited filler nanomaterial by comparing different types of carbon nanotubes such as; branched, single-walled and multi-walled carbon nanotubes, which were added in only 2 wt %. Different types of interactions (polar-polar and CH-π and donor-acceptor) make b-MWCNT more dispersible in the PVDF matrix, which together with high crystallinity resulted in the best electrical conductivity and electromagnetic shielding ability of this composite. This investigation additionally conceals the issues related to the thickness of the shield material just by stacking individual thin nanocomposite layers containing different carbon nanotube (CNT) types with 0.3 mm thickness in a simple manner and finally achieves 99.999% shielding efficiency at just 0.9 mm thickness when using a suitable order of the different PVDF based nanocomposites.

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Kreß, Sebastian, Roland Schaller-Ammann, Jürgen Feiel, Joachim Priedl, Cornelia Kasper, and Dominik Egger. "3D Printing of Cell Culture Devices: Assessment and Prevention of the Cytotoxicity of Photopolymers for Stereolithography." Materials 13, no. 13 (July 6, 2020): 3011. http://dx.doi.org/10.3390/ma13133011.

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3D printing is increasingly important for the rapid prototyping of advanced and tailor-made cell culture devices. In this context, stereolithography represents a method for the rapid generation of prototypes from photocurable polymers. However, the biocompatibility of commercially available photopolymers is largely unknown. Therefore, we evaluated the cytotoxicity of six polymers, two of them certified as biocompatible according to ISO 10993-5:2009, and we evaluated, if coating with Parylene, an inert polymer widely used in medical applications, might shield cells from the cytotoxic effects of a toxic polymer. In addition, we evaluated the processability, reliability, and consistency of the details printed. Human mesenchymal stem cells (MSCs) were used for cytotoxicity testing as they are widely used and promising for numerous applications in regenerative medicine. MSCs were incubated together with printed photopolymers, and the cytotoxicity was assessed. All photopolymers significantly reduced the viability of MSCs while the officially biocompatible resins displayed minor toxic effects. Further, coating with Parylene completely protected MSCs from toxic effects. In conclusion, none of the tested polymers can be fully recommended for rapid prototyping of cell culture devices. However, coating with Parylene can shield cells from toxic effects and thus might represent a viable option until more compatible materials are available.

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Rajan, Robin, and Kazuaki Matsumura. "A zwitterionic polymer as a novel inhibitor of protein aggregation." Journal of Materials Chemistry B 3, no. 28 (2015): 5683–89. http://dx.doi.org/10.1039/c5tb01021g.

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A zwitterionic polymer was synthesized via RAFT polymerization. This polymer prevented heat induced protein aggregation, by preventing hydrophobic interactions between protein chains in solution, thus acting as a molecular shield.

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Mohammed SHAREEF, Amjed. "INVESTIGATION OF SHIELDING PARAMETERS TO FABRICATED SHIELDS FROM POLYMER WITH NANO-BARIUM OXIDE MATERIALS." MINAR International Journal of Applied Sciences and Technology 4, no. 4 (December 1, 2022): 7–14. http://dx.doi.org/10.47832/2717-8234.13.2.

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Researchers have long been involved in improving new and effective radiation-protection materials. In this study, we will verify the measurement of the attenuation coefficient of gamma rays, which is considered one of the most important points of protection from ionizing radiation, by fabricating a radiation-protective shield made by combining pol unsaturated polyester as a base material for the shield and reinforced by varying concentrations of the nano- barium oxide (BaO) in different proportions (15,25,35 and 45) %. Making use of an ultrasonic stirrer, and the radiation shielding properties of gamma rays are presented for the energies shown in this article. The results reveal that nanostructured samples are preferable at the linear and mass attenuation coefficients (LAC and MAC), the value of the shield's electronic density(Ne), and the value of radiation protection effectiveness (PRE) increased with the increase of reference material, which are considered good materials in radiation protection, but decreased with the increase in gamma ray energy. Keywords: BAO, LAC, MAC, NE, PRE

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Almurayshid, Mansour, Yousif Alssalim, Farouk Aksouh, Rashed Almsalam, Meshari ALQahtani, M. I. Sayyed, and Fahad Almasoud. "Development of New Lead-Free Composite Materials as Potential Radiation Shields." Materials 14, no. 17 (August 30, 2021): 4957. http://dx.doi.org/10.3390/ma14174957.

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Utilizing a polymer-based radiation shield offers lightweight, low cost, non-toxic compared to lead and solution for eliminating generated secondary neutrons. Incorporating silicon (i.e., one of the most abundant elements) in new applications, such as shielding, would have an impact on the economy and industry. In this study, seven potential shielding materials, composed of silicon, silicon carbide, and boron carbide embedded ethylene vinyl acetate (EVA) copolymers, are proposed. The shielding performance of these composite materials, including the attenuation coefficients (µ), the mass attenuation coefficients (µm), the half value layer (HVL), the mean free path (MFP), and the radiation protection efficiency (RPE) were examined using photon beams. Measured µm were verified against the calculated values. The averaged agreement was within ±7.4% between the experimental measurements and the theoretical calculation results. The HVL and MFP measured values for the polymer composites were lower than that for the pure EVA polymer, indicating the fillers in the polymers enhanced the shielding performance. The EVA + SiC (30%) and EVA + Si (15%) + B4C (15%) composites required the lowest thickness to stop 50% of the incident photons. The evaluation of experimental results of the RPE revealed that the polymer composites containing SiC (30%), Si (15%) + B4C (15%), or SiC (15%) + B4C (15%) succeeded in blocking 90–91% of X-rays at nearly 80 keV. However, a thicker shield of the proposed composite materials or combined layers with other high-Z materials could be used for higher energies.

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Xu, Hu, Dan Liu, Wei-Qiang Sun, Rong-Jun Wu, Wu Liao, Xiao-Ling Li, Guang Hu, and Hua-Si Hu. "Study on the Design, Preparation, and Performance Evaluation of Heat-Resistant Interlayer-Polyimide-Resin-Based Neutron-Shielding Materials." Materials 15, no. 9 (April 19, 2022): 2978. http://dx.doi.org/10.3390/ma15092978.

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Polymers have an excellent effect in terms of moderating fast neutrons with rich hydrogen and carbon, which plays an indispensable role in shielding devices. As the shielding of neutrons is typically accompanied by the generation of γ-rays, shielding materials are developed from monomers to multi-component composites, multi-layer structures, and even complex structures. In this paper, based on the typical multilayer structure, the integrated design of the shield component structure and the preparation and performance evaluation of the materials is carried out based on the design sample of the heat-resistant lightweight polymer-based interlayer. Through calculation, the component structure of the polymer-based materials and the three-layer thickness of the shield are obtained. The mass fraction of boron carbide accounts for 11% of the polymer-based material. Since the polymer-based material is the weak link of heat resistance of the multilayer shield, in terms of material selection and modification, the B4C/TiO2/polyimide molded plate was prepared by the hot-pressing method, and characterization analysis was conducted for its structure and properties. The results show that the ball milling method can mix the materials well and realize the uniform dispersion of B4C and TiO2 in the polyimide matrices. Boron carbide particles are evenly distributed in the material. Except for Ti, the other elemental content of the selected areas for mapping is in good agreement with the theoretical values of the elemental content of the system. The prepared B4C/TiO2/polyimide molded plate presents excellent thermal properties, and its glass transition temperature and initial thermal decomposition temperature are as high as 363.6 °C and 572.8 °C, respectively. In addition, the molded plate has good toughness performs well in compression resistance, shock resistance, and thermal aging resistance, which allows it to be used for a long time under 300 °C. Finally, the prepared materials are tested experimentally on an americium beryllium neutron source. The experimental results match the simulation results well.

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Guo, Zhaoyuan, Yun Bai, Zhuangzhuang Zhang, Heng Mei, Jing Li, Yuji Pu, Nan Zhao, et al. "Thermosensitive polymer hydrogel as a physical shield on colonic mucosa for colitis treatment." Journal of Materials Chemistry B 9, no. 18 (2021): 3874–84. http://dx.doi.org/10.1039/d1tb00499a.

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Oh, Jun Yong, Gyeongseok Yang, Eunshil Choi, and Ja-Hyoung Ryu. "Mesoporous silica nanoparticle-supported nanocarriers with enhanced drug loading, encapsulation stability, and targeting efficiency." Biomaterials Science 10, no. 6 (2022): 1448–55. http://dx.doi.org/10.1039/d2bm00010e.

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Wu, Cai-Ying, and Walter A. Aue. "Protected porous polymers." Canadian Journal of Chemistry 67, no. 3 (March 1, 1989): 389–401. http://dx.doi.org/10.1139/v89-062.

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This study was designed to answer the question whether the chromatographic performance of porous polymers — serving here as a model system for pressure-sensitive separation media of relatively large mass transfer resistance — could be improved (a) by imposing on them a chromatographically favorable, extrinsic macrostructure and (b) by protecting that macrostructure against physical deformation. Packed-column gas chromatography was used as the test system.Protected porous polymers (PPP's) were synthesized from pure divinylbenzene (DVB) inside conventional diatomaceous supports, using various amounts and types of porogens. The non-extractable polymer loads ranged from 10 to 40% and conformed to (i.e. formed layers on) the diatomaceous macrostructures. The best plate numbers were in excess of 4000/m on a 100/120 mesh Chromosorb W base. The mass transfer resistance of these materials was very low and permitted high flow rates. The PPP's could be used up to 280 °C and did not appear to suffer deformation; in fact, the polymer appeared to shield the diatom supports from abrasion. The data indicate that the porous polymer deposits had relatively high specific surface areas, and produced a relatively large value for the free energy of sorption per methylene group, as compared with conventional porous polymer beads. Otherwise, protected and unprotected types of porous polymers had similar chromatographic characteristics. Keywords: porous polymer, poly(divinylbenzene), gas chromatography, protected polymer, diatoms.

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Osman, Nurul Huda, Nurul Najiha Mazu, Josephine Ying Chyi Liew, Muhammad Mahyiddin Ramli, Andrei Victor Sandu, Marcin Nabiałek, Mohammad Abdull Halim Mohd Abdull Majid, and Hazeem Ikhwan Mazlan. "Sodium-Based Chitosan Polymer Embedded with Copper Selenide (CuSe) Flexible Film for High Electromagnetic Interference (EMI) Shielding Efficiency." Magnetochemistry 7, no. 7 (July 12, 2021): 102. http://dx.doi.org/10.3390/magnetochemistry7070102.

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Efficient shielding materials are extremely important to minimize the effect of electromagnetic interference. Currently, various composite materials are being investigated with different shielding efficiencies reported. In this paper, a flexible and free-standing sodium-based chitosan (CH/Na) polymer with copper selenide (CuSe) filler was prepared for electromagnetic shielding. The CH/Na/CuSe polymer matrix was prepared via the direct casting technique at different wt% of CuSe, varying from 2 to 20 wt%. The polymer matrix was then characterised by using Fourier transform infrared (FTIR) spectroscopy to confirm the interaction between the CH/Na and CuSe. The XRD results revealed that the CH/Na/CuSe polymer was successfully formed. Improvement in the electrical conductivity was confirmed by an impedance spectroscopy measurement. The highest electrical conduction recorded was at 3.69 × 10−5 S/cm for CH/Na/CuSe polymer matrix with 20 wt% CuSe. An increase in total electromagnetic interference (EMI) shielding efficiency (SET) of up to 20 dB (99% EM power shield) was achieved, and it can be increased up to 34 dB (99.9% EM power shield) with the thickness of the polymer increased.

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Yang, Deng, and Yildiz Bayazitoglu. "Polymer Composites as Radiation Shield Against Galactic Cosmic Rays." Journal of Thermophysics and Heat Transfer 34, no. 2 (April 2020): 457–64. http://dx.doi.org/10.2514/1.t5862.

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Almurayshid, Mansour, Sultan Alsagabi, Yousif Alssalim, Zayed Alotaibi, and Rashed Almsalam. "Feasibility of polymer-based composite materials as radiation shield." Radiation Physics and Chemistry 183 (June 2021): 109425. http://dx.doi.org/10.1016/j.radphyschem.2021.109425.

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Bahramian, Ahmad Reza, and Mehrdad Kokabi. "Ablation mechanism of polymer layered silicate nanocomposite heat shield." Journal of Hazardous Materials 166, no. 1 (July 2009): 445–54. http://dx.doi.org/10.1016/j.jhazmat.2008.11.061.

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Wen, Yuting, Hongzhen Bai, Jingling Zhu, Xia Song, Guping Tang, and Jun Li. "A supramolecular platform for controlling and optimizing molecular architectures of siRNA targeted delivery vehicles." Science Advances 6, no. 31 (July 2020): eabc2148. http://dx.doi.org/10.1126/sciadv.abc2148.

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It requires multistep synthesis and conjugation processes to incorporate multifunctionalities into a polyplex gene vehicle to overcome numerous hurdles during gene delivery. Here, we describe a supramolecular platform to precisely control, screen, and optimize molecular architectures of siRNA targeted delivery vehicles, which is based on rationally designed host-guest complexation between a β-cyclodextrin–based cationic host polymer and a library of guest polymers with various PEG shape and size, and various density of ligands. The host polymer is responsible to load/unload siRNA, while the guest polymer is responsible to shield the vehicles from nonspecific cellular uptake, to prolong their circulation time, and to target tumor cells. A series of precisely controlled molecular architectures through a simple assembly process allow for a rapid optimization of siRNA delivery vehicles in vitro and in vivo for therapeutic siRNA-Bcl2 delivery and tumor therapy, indicating the platform is a powerful screening tool for targeted gene delivery vehicles.

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Alshahri, Saad, Mohammed Alsuhybani, Eid Alosime, Mansour Almurayshid, Alhanouf Alrwais, and Salha Alotaibi. "LDPE/Bismuth Oxide Nanocomposite: Preparation, Characterization and Application in X-ray Shielding." Polymers 13, no. 18 (September 13, 2021): 3081. http://dx.doi.org/10.3390/polym13183081.

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Recently developed polymer-based composites could prove useful in many applications such as in radiation shielding. In this work, the potential of a bismuth oxide (Bi2O3) nanofiller based on an LDPE polymer was developed as lead-free X-ray radiation shielding offering the benefits of lightness, low-cost and non-toxic compared to pure lead. Three different LDPE-based composites were prepared with varying weight percentages of Bi2O3: 5%, 10% and 15%. The characterizations were extended to include structural properties, physical features, mechanical and thermal properties, and radiation shielding efficiency for the prepared nanocomposites. The results revealed that the incorporation of the Bi2O3 nanofiller into an LDPE improved the density of the composites. There was also a slight increase in the tensile strength and tensile modulus. In addition, there was a clear improvement in the efficiency of the shield when fillers were added to the LDPE polymer. The LDPE + Bi2O3 (15%) composite needed the lowest thickness to attenuate 50% of the incident X-rays. The LDPE + Bi2O3 (15%) polymer can also block around 80% of X-rays at 47.9 keV. In real practice, a thicker shield of the proposed composite materials, or a higher percentage of the filler could be employed to safely ensure the radiation is blocked.

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Pikis, Stylianos, Georgios Mantziaris, Vasileios Mamalis, Konstantinos Barkas, Antonios Tsanis, Stavroula Lyra, Kuriakos Karkoulias, Tigran Petrosyan, and Eftychios Archontakis. "Diffusion weighted image documented cerebral ischemia in the postprocedural period following pipeline embolization device with shield technology treatment of unruptured intracranial aneurysms: a prospective, single center study." Journal of NeuroInterventional Surgery 12, no. 4 (September 26, 2019): 407–11. http://dx.doi.org/10.1136/neurintsurg-2019-015363.

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ObjectiveAcute ischemic stroke and silent cerebral infarctions following pipeline embolization device (PED) treatment of intracranial aneurysms have been estimated to occur in 3–6% and in 50.9–90% of patients respectively. The PED with Shield technology (PED-Shield) incorporates a surface phosphorylcholine polymer to reduce the thrombogenicity of the implant. We sought to determine the incidence of diffusion weighted image (DWI) documented cerebral ischemia after PED-Shield treatment of unruptured intracranial aneurysms.MethodsThis prospective study involved a single center series of consecutive patients treated for an unruptured intracranial aneurysm with the PED-Shield. All participants underwent clinical evaluation on admission, after the procedure, at discharge, and 30 days following treatment. Brain MRI was obtained within 72 hours of the procedure. Ischemic lesions identified on DWI sequences where examined as to their number, size, and location in relation to the procedure.ResultsOver 12 months, 33 patients harboring 38 intracranial aneurysms were treated with the PED-Shield in 36 procedures. Neither mortality nor clinically evident ischemic events were noted in the 30 day postprocedural period. DWI documented, silent cerebral ischemia occurred in six patients (18.18%) after six procedures (16.66%). No statistically significant risk factors for postprocedural silent cerebral ischemia were identified.ConclusionWe demonstrated a reduced rate of silent cerebral infarcts following PED-Shield treatment of intracranial aneurysms than previously reported with other endovascular treatment modalities and with the previous device generations. Further research is necessary to evaluate our results and to identify methods to reduce the incidence of postprocedural cerebral ischemic events.

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Cui, Ying, and Zhongsheng Tan. "Experimental Study of High Performance Synchronous Grouting Materials Prepared with Clay." Materials 14, no. 6 (March 11, 2021): 1362. http://dx.doi.org/10.3390/ma14061362.

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Shield construction discharges a large amount of soil and muck. The utilization of discharged soil of shield always has high energy consumption and a low utilization rate. Meanwhile, synchronous grouting is a key process for shield tunneling. The current studies show that the synchronous grouting materials applied now generally have the problem of mismatching among filling property, fluidity, and consolidation strength. In order to study the feasibility of using the excavated soil produced by shield construction in clay stratum as synchronous grouting material, high performance synchronous grouting material was studied by taking red clay as an example, modified by epoxy resin. The fluidity, stability, and strength were measured to evaluate performance of the grout. Material test results show that the addition of waterborne epoxy resin decreases density, improves the stability, the rate of stone, and the toughness of the grouting concretion. Finally, X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) were measured to analyze the cementitious mechanism of the grout, test results demonstrated that cement hydration and curing reaction of epoxy resin happened in the grout, the formed polymer film filled the voids in the mixture and effectively bound cement hydration gel and clay particles together.

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Qiu, Yuan, Elena Rojas, Richard A. Murray, Joseba Irigoyen, Danijela Gregurec, Pablo Castro-Hartmann, Jana Fledderman, Irina Estrela-Lopis, Edwin Donath, and Sergio E. Moya. "Cell uptake, intracellular distribution, fate and reactive oxygen species generation of polymer brush engineered CeO2−xNPs." Nanoscale 7, no. 15 (2015): 6588–98. http://dx.doi.org/10.1039/c5nr00884k.

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Lam, Yan Tung, Rania Hussien Al-Ashwal, Mohd Helmi bin Sani, and Sadeq M. Al-Hazmy. "Reduced Glutathione Antioxidant Stability in Polymer Solutions Toward Wound Bioactive Dressing Application." Key Engineering Materials 931 (September 9, 2022): 77–82. http://dx.doi.org/10.4028/p-ga2z38.

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Reduced glutathione (GSH) is incorporated in polymeric wound dressings to prevent oxidative stress-induced cellular damage and the development of chronic wounds. The present study investigates the influence of polyvinyl alcohol (PVA), polyethylene oxide (PEO), and PVA/PEO blend polymeric solutions on the stability of GSH during the preparations or storage. The stability was studied in three concentrations which were 3%, 5% and 8%, after sometimes between 0 to 7 days. The level of GSH achieved the highest electron donor activity at day 7 in 8% PVA/PEO (95.42%) and 8% PVA (94.27%) solutions, whereas GSH activity decreased when incorporated with PEO solutions. Such a decrease in the GSH activity due to PEO being less water-resistant and hydrolytic degradation susceptibility could expose the GSH to an aqueous environment and lead to the loss of GSH activity. In conclusion, a higher concentration of polymer and less-water resistant polymers can shield the GSH from an aqueous environment and maintain its stability in the polymer solutions used in wound dressing applications.

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Martínez-Galdámez, Mario, Saleh M. Lamin, Konstantinos G. Lagios, Thomas Liebig, Elisa F. Ciceri, Rene Chapot, Luc Stockx, et al. "Treatment of intracranial aneurysms using the pipeline flex embolization device with shield technology: angiographic and safety outcomes at 1-year follow-up." Journal of NeuroInterventional Surgery 11, no. 4 (September 27, 2018): 396–99. http://dx.doi.org/10.1136/neurintsurg-2018-014204.

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PurposeThe Pipeline Embolization Device (PED) is a routine first-line treatment option for intracranial aneurysms (IAs). The Pipeline Flex Embolization Device with Shield Technology (Pipeline Shield) is an updated version of the PED which has been modified to include a surface phosphorylcholine biocompatible polymer. Its early technical success and safety have been reported previously. Here, we assessed the long-term safety and efficacy of the Pipeline Shield for the treatment of IAs.Materials and methodsThe Pipeline Flex Embolization Device with Shield Technology (PFLEX) study was a prospective, single-arm, multicenter study for the treatment of unruptured IAs using the Pipeline Shield. The primary endpoint was a major stroke in the territory supplied by the treated artery or neurologic death at 1-year post-procedure. Angiographic outcomes were also assessed by an independent radiology laboratory at 6 months and 1 year.ResultsFifty patients (mean age, 53 years; 82% female) with 50 unruptured IAs were treated. Mean aneurysm diameter was 8.82±6.15 mm. Of the target aneurysms, 38/50 (76%) were small (<10 mm), 11/50 (22%) were large (≥10 and<25 mm), and 1/50 (2%) was giant (≥25 mm). Forty-seven (94%) were located in the internal carotid artery and three (6%) in the vertebral artery. At 1-year post-procedure, no major strokes or neurologic deaths were reported, and complete occlusion was achieved in 27/33 (81.8%). There were no instances of aneurysm recurrence or retreatment.ConclusionsOur 1-year follow-up concerning angiographic and safety outcomes corroborate previous evidence that the Pipeline Shield is a safe and effective treatment for IAs.Trial registration numberNCT02390037

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Alarifi, Ibrahim. "Advanced selection in polymer-composite materials for radiation shielding and their properties - A comprehensive review." Journal of Nuclear and Radiation Sciences 1, no. 1 (2022): 1. http://dx.doi.org/10.5455/jnrs.2022.01.001.

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In this review article, the research considers at the current innovation regarding the selection of polymer composites materials that are reinforced with micro and nano particles, specifically for the purpose of using them as radiation shields. The effectiveness of a substance as a radiation shield is often evaluated based on how well it can prevent the penetration of incident radiation via various interaction processes. However beneficial radiation may be to human health and the environment, it also poses a considerable risk. There hasn't been a lot of investigation into the shielding capabilities of FRP composites with lead nanoparticle extracts. In this research, seven different possible shielding materials are offered. These materials are embedded ethylene vinyl acetate (EVA) copolymers containing silicon, silicon carbide, and boron carbide. It is possible to conclude that the incorporation of lead nanoparticles into fiber composite materials is suggested for a variety of applications. The investigated composite material had qualities like improved high strength, density, and exceptional hardness. One example of this would be requests in the aviation industry, which require light weights but are exposed to high radiation levels.

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Wang, Gui He, and Yu You Yang. "Study on Soil Improvement Technology of EPBS Tunnel." Advanced Materials Research 378-379 (October 2011): 484–88. http://dx.doi.org/10.4028/www.scientific.net/amr.378-379.484.

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The tunnel construction often encounters the problem of adaptability of sand-gravel formation and earth pressure balance shield (EPBS) construction, which has brought new technical problems and challenges to those who are participating in the construction project. In order to ensure the normal operation of shield construction, the soil must have ideal plasticity and liquidity, and low permeability to intercept groundwater. Therefore, we must adopt the soil improvement techniques ,namely, to inject the modified materials (mud, foam, polymer, etc.) into excavation face and earth pressure tank(if necessary, to the screw conveyor) to ensure the stability of excavation face, achieve EPBS driving, and help to reduce mechanical load, reduce land subsidence, and increase driving speed at the same time. The ground improvement technique is an important part of the EPBS method. The quality of the application of soil improvement technology is very important to maintain the stability of excavation face and the screw dump device’s dumping smoothly. It also has a significant impact on the shield machine’s functioning safely,economically and efficiently.

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Kim, Soochan, Xin Yang, Misuk Cho, and Youngkwan Lee. "Nanostructured conductive polymer shield for highly reversible dendrite-free zinc metal anode." Chemical Engineering Journal 427 (January 2022): 131954. http://dx.doi.org/10.1016/j.cej.2021.131954.

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Arief, Injamamul, Yudhajit Bhattacharjee, Om Prakash, Megha Sahu, Satyam Suwas, and Suryasarathi Bose. "Tunable CoNi microstructures in flexible multilayered polymer films can shield electromagnetic radiation." Composites Part B: Engineering 177 (November 2019): 107283. http://dx.doi.org/10.1016/j.compositesb.2019.107283.

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Mostafavi Yazdi, Seyed Jamaleddin, Andrej Lisitski, Seongchan Pack, Huseyin R. Hiziroglu, and Javad Baqersad. "Analysis of Shielding Effectiveness against Electromagnetic Interference (EMI) for Metal-Coated Polymeric Materials." Polymers 15, no. 8 (April 16, 2023): 1911. http://dx.doi.org/10.3390/polym15081911.

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Lightweight materials, such as polymers and composites, are increasingly used in the automotive and aerospace industries. Recently, there has been an increase in the use of these materials, especially in electric vehicles. However, these materials cannot shield sensitive electronics from electromagnetic interference (EMI). The current work investigates the EMI performance of these lightweight materials using an experimental setup based on the ASTM D4935-99 standard and EMI simulation using the ANSYS HFSS. This work studies how metal coating from zinc and aluminum bronze can improve the shielding performance of polymer-based materials, such as polyphenylene sulfide (PPS), polyetheretherketone (PEEK), and polyphthalamide (PPA). Based on the findings of this study, a thin coating (50 μm) of Zn on the surface of PPS and a thin coating of 5 μm and 10 μm of Al-Bronze, respectively, on the surface of PEEK and PPA have indicated an increase in the shielding effectiveness (SE) when subjected to EMI. The shielding effectiveness significantly increased from 7 dB for the uncoated polymer to approximately 40 dB at low frequencies and up to approximately 60 dB at high frequencies for coated polymers. Finally, various approaches are recommended for improving the SE of polymeric materials under the influence of EMI.

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Jabbar, Rashid Hashim, Israa Hadi Hilal, Sameera Ahmed Ebrahiem, Mudar Ahmed Abdulsattar, Mahdi M. Mutter, and Sarah Rashid Hashim. "Fabrication of polymer nanocomposite (PbO and W2O3) for gamma-ray attenuations." Journal of Physics: Conference Series 2322, no. 1 (August 1, 2022): 012064. http://dx.doi.org/10.1088/1742-6596/2322/1/012064.

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Abstract (PbO and W2O3) nanocomposite has been prepared by adding a fixed ratio of PbO nanoparticles about (0.05) wt.% with different concentrations of W2O3 (0.05, 0.1, 0.15, 0.2, 0.25) wt.% with epoxy 405.thickness of samples is 0.3 cm to use as a protective shield of gamma-ray, structural properties of the samples have been studied by X-ray diffraction (XRD), Atom Force Microscope (AFM), and Nuclear Magnetic Resonance (NMR). Gamma-ray is reduced with the increasing of the (PbO and W2O3) concentrations caused by the increasing linear attenuation coefficient.

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Kim, Tae-Hwan, In-Mo Lee, Hee-Young Chung, Jeong-Jun Park, and Young-Moo Ryu. "Application Ranges of EPB Shield TBM in Weathered Granite Soil: A Laboratory Scale Study." Applied Sciences 11, no. 7 (March 26, 2021): 2995. http://dx.doi.org/10.3390/app11072995.

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Soil conditioning is a key factor in increasing tunnel face stability and extraction efficiency of excavated soil when excavating tunnels using an earth pressure balance (EPB) shield tunnel boring machine (TBM). Weathered granite soil, which is abundant in the Korean Peninsula (also in Japan, Hong Kong, and Singapore), has different characteristics than sand and clay; it also has particle-crushing characteristics. Conditioning agents were mixed with weathered granite soils of different individual particle-size gradations, and three characteristics (workability, permeability, and compressibility) were evaluated to find an optimal conditioning method. The lower and upper bounds of the water content that are needed for a well-functioning EPB shield TBM were also proposed. Through a trial-and-error experimental analysis, it was confirmed that soil conditioning using foam only was possible when the water content was controlled within the allowable range, that is, between the upper and lower bounds; when water content exceeded the upper bound, soil conditioning with solidification agents was needed along with foam. By taking advantage of the particle-crushing characteristics of the weathered granite soil, it was feasible to adopt the EPB shield TBM even when the soil was extremely coarse and cohesionless by conditioning with polymer slurries along with foam. Finally, the application ranges of EPB shield TBM in weathered granite soil were proposed; the newly proposed ranges are wider and expanded to coarser zones compared with those proposed so far.

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Gençaslan, Mustafa. "Investigation of the global phase behavior of polymer mixtures in the shield region." Journal of Chemical Physics 136, no. 22 (June 14, 2012): 224901. http://dx.doi.org/10.1063/1.4726405.

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Shahzad, Faisal, Seung Hwan Lee, Soon Man Hong, and Chong Min Koo. "Segregated reduced graphene oxide polymer composite as a high performance electromagnetic interference shield." Research on Chemical Intermediates 44, no. 8 (January 18, 2018): 4707–19. http://dx.doi.org/10.1007/s11164-018-3274-7.

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Dreaden, Erik C., Lacey A. Perdue, Priscilla Do, Andy Chyong, Khalid Salaita, Gregory Lesinski, and Christopher C. Porter. "Photo-regulated control of cytokine signaling via bioinspired, polymer-induced latency." Journal of Immunology 204, no. 1_Supplement (May 1, 2020): 246.10. http://dx.doi.org/10.4049/jimmunol.204.supp.246.10.

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Abstract Cytokine signaling is challenging to study or therapeutically modulate as the effects of these protein are often pleotropic and context-dependent. One mechanism by which cytokines with diverse effects can, however, transmit cell type-specific information is via expression in an inactive, or latent, form in which the protein is sterically shielded by a binding partner that is later displaced or degraded (e.g. TGF-β1 association with GARP or LAP). Inspired by this precision, we hypothesized that photo-reversible chemical modification could impart orthogonal specificity to cytokines not expressed in a latent state, such as IL-2, IL-15, or IL-12. Here, we describe a strategy whereby cytokines are modified with photo-labile polymers that mimic the induction of latency while appended, then de-shield to recover protein activity in response to monochromatic light exposure, thus controlling the magnitude, duration, and location of cytokine signals. Using this strategy, we show that latent IL-2 and IL-15 activity can be photo-modulated as much as 103-fold and that polymer-induced IL-2 latency, alone, can bias affinity away from immunosuppressive CD25 binding. We further show that protein de-repression can be achieved with spatial resolution approaching that of a single immune cell and demonstrate the feasibility of transcutaneous IL-2 photoactivation using engineered tissue phantoms. We find that such modifications also prolong the circulation of IL-12 in vivo, thus obviating the need for frequent, high dosing in therapeutic settings. Future extensions of this approach could enable multicolor, optical reprogramming of cytokine signaling networks and lead to immunotherapies that are more tissue-specific and patient-personalized.

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Kim, Jaeyeon, Suyeong Lee, Changho Kim, Yeongcheol Park, Mi-Hyun Kim, and Jae Hun Seol. "Electromagnetic Interference Shield of Highly Thermal-Conducting, Light-Weight, and Flexible Electrospun Nylon 66 Nanofiber-Silver Multi-Layer Film." Polymers 12, no. 8 (August 11, 2020): 1805. http://dx.doi.org/10.3390/polym12081805.

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A light-weight, flexible electromagnetic interference (EMI) shield was prepared by creating a layer-structured metal-polymer composite film consisting of electrospun nylon 66 nanofibers with silver films. The EMI shielding effectiveness (SE), specific SE, and absolute SE of the composite were as high as 60.6 dB, 67.9 dB cm3/g, and 6792 dB cm2/g in the X- and Ku-bands, respectively. Numerical and analytical calculations suggest that the energy of EM waves is predominantly absorbed by inter-layer multiple reflections. Because the absorbed EM energy is dissipated as heat, the thermal conductivity of absorption-dominant EMI shields is highly significant. Measured thermal conductivity of the composite was found to be 4.17 Wm−1K−1 at room temperature, which is higher than that of bulk nylon 66 by a factor of 16.7. The morphology and crystallinity of the composite were examined using scanning electron microscopy and differential scanning calorimetry, respectively. The enhancement of thermal conductivity was attributed to an increase in crystallinity of the nanofibers, which occurred during the electrospinning and subsequent hot pressing, and to the high thermal conductivity of the deposited silver films. The contribution of each fabrication process to the increase in thermal conductivity was investigated by measuring the thermal conductivity values after each fabrication process.

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BOREL, Stéphan, Edouard DESCHASEAUX, Jean CHARBONNIER, Philippe MEDINA, Stéphanie ANCEAU, Jessy CLEDIERE, Romain WACQUEZ, et al. "Backside Shield against Physical Attacks for Secure ICs." Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2017, DPC (January 1, 2017): 1–15. http://dx.doi.org/10.4071/2017dpc-wp1_presentation2.

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Although the implementation of multiple countermeasures, both hardware and software, are making integrated circuits more and more secure, the backside of a chip is still considered as a vulnerability regarding physical attacks. A novel protection structure will be presented here, which consists in combining several elements to make it impossible for a hacker to use the backside of a chip as an access to the active parts of the IC without triggering an alert. The integration flow is using standard processes coming from the world of packaging and it is applied on commonly available industrial tools. Cybersecurity by hardware can thus be implemented at low additional cost. In order to weaken the chip in case of milling, deep cavities are etched into the substrate. They are lined with a 3D metallic shield that block the IR wavelengths commonly used for fault injection. This part of the structure is fabricated using standard TSV last process steps. These cavities are then corked with a polymer so that RDL-like metallic serpentines connected to TSVs can meander all over the protected area. This constitutes the active part of the shield, since the integrity of the serpentines can be controlled by measuring their electrical resistance. Finally the structure is covered with a thick protection layer with specific properties: it is FIB-resistant and fully opaque to IR. In order to evaluate the efficiency of the countermeasures, a test vehicle has been designed and fabricated with metal pads on one side and with the protection structure on the other side. The backside process was done using a glass carrier in order to handle the wafers after thinning below 200μm. After debonding, the wafers were tested and singulated before being hacked. A realistic scenario of physical attacks will be presented together with the physical, optical and electrical characterizations after the different attacks including (P)FIB ablation, micro-milling, chemical etching and laser illumination. We will conclude on the interest of such a structure for IoT or other applications that require protecting confidential data.

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Ding, Zhongli, Robin B. Fong, Cynthia J. Long, Patrick S. Stayton, and Allan S. Hoffman. "Size-dependent control of the binding of biotinylated proteins to streptavidin using a polymer shield." Nature 411, no. 6833 (May 2001): 59–62. http://dx.doi.org/10.1038/35075028.

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Szymczak, Tadeusz, and Zbigniew Kowalewski. "Strength tests of polymer-glass composite to evaluate its operational suitability for ballistic shield plates." Eksploatacja i Niezawodnosc - Maintenance and Reliability 22, no. 4 (September 20, 2020): 592–600. http://dx.doi.org/10.17531/ein.2020.4.2.

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Ma, Xue, Fuming Wang, Chengchao Guo, Jichun Zhang, Xuanxuan Chu, and Man Yang. "Dynamic centrifuge test of shield tunnels with non-water reacting two-component polymer buffer layer." Tunnelling and Underground Space Technology 139 (September 2023): 105116. http://dx.doi.org/10.1016/j.tust.2023.105116.

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Arend, Johannes, Alexander Wetzel, and Bernhard Middendorf. "Fluorescence Microscopic Investigations of the Retarding Effect of Superplasticizers in Cementitious Systems of UHPC." Materials 13, no. 5 (February 27, 2020): 1057. http://dx.doi.org/10.3390/ma13051057.

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The adsorption of superplasticizer molecules to particle surfaces in cementitious systems is a very important aspect for the desired liquefaction of pastes and concretes. This way, the comb shaped polymers shield attractive forces between the particles and induce a well-dispersed, homogeneous suspension. These admixtures allow the usage of fine fillers even in combination with low amounts of mixing water, and thus, are the basis for modern high performance concretes. However, the adsorption does not cause beneficial effects only: The polymer covered particle surfaces, especially clinker, are hindered to interact with water, thus hydration is retarded. This is the reason for lower early strength and is very disadvantageous for certain applications. Today it is known that the molecular structure of the polymers, for instance the chain length and charge density, affects the retardation strongly. The complexity and diversity of cementitious systems is the main reason why research in this field is quite empiric and time as well as cost intensive. To investigate the adsorption of superplasticizers in various systems in-situ, a fluorescence microscopic approach was applied: By staining the polymers with fluorescent dye they become localizable and the adsorption quantifiable. This work shows the influence of molecular structure to adsorption characteristic of different polymers and the correlation to the retarding effect of superplasticizers, especially concerning the presence of silica fume, which is indispensable for ultra-high performance concrete (UHPC).

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Yang, Yi, Xinggao Li, and Xingchun Li. "Shear Strength and Compression Coefficient for Conditioned Sand Subjected to Earth Chamber Stress Levels." Advances in Materials Science and Engineering 2018 (October 11, 2018): 1–11. http://dx.doi.org/10.1155/2018/1759151.

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Ground conditioning agents are often needed when performing earth pressure balance shield tunneling in sand soils due to its high internal friction, low plastic ductility, and low compressibility. In this work, vane shear and compression tests for standard sand were performed using a homemade test device, and three types of conditioning agents composed of foam, bentonite slurry, and polymer were used in the tests. The effects of the agents on shear strength and compressibility of the conditioned soils were investigated under a typical earth chamber stress level as high as 2 bar. The measured results show that foam does better in reducing shear strength and improving the compressibility of the conditioned soils than bentonite slurry and polymer. Significant increases in the compressibility of foam-conditioned soils can be achieved using foam, and the shear strength of the conditioned sand can be decreased by more than 30% with an initial injection ratio of 40% foam. The bentonite- and polymer-conditioned sands have similar compressibility. The HPMC (hydroxypropyl methylcellulose) polymer does better in decreasing the shear strength of the conditioned soils than other liquid soil conditioners. The influences of the device shear rate on the shear strength of the conditioned soils are also presented.

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Martínez-Galdámez, Mario, Jorge Escartín, Boris Pabón, Carlos Diaz, Roberto Martín-Reyes, Antonio Hermosín, Eduardo Crespo, et al. "Optical coherence tomography: Translation from 3D-printed vascular models of the anterior cerebral circulation to the first human images of implanted surface modified flow diverters." Interventional Neuroradiology 25, no. 2 (November 5, 2018): 150–56. http://dx.doi.org/10.1177/1591019918808466.

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Background The new generation of flow diverters includes a surface modification with a synthetic biocompatible polymer, which makes the device more biocompatible and less thrombogenic. Optical coherence tomography (OCT) can be used to visualize perforators, stent wall apposition, and intra-stent thrombus. Unfortunately real world application of this technology has been limited because of the limited navigability of these devices in the intracranial vessels. In this report, we share our experience of using 3D-printed neurovascular anatomy models to simulate and test the navigability of a commercially available OCT system and to show the application of this device in a patient treated with the new generation of surface modified flow diverters. Material and methods Navigability of OCT catheters was tested in vitro using four different 3D-printed silicone replicas of the intracranial anterior circulation, after the implantation of surface modified devices. Intermediate catheters were used in different tortuous anatomies and positions. After this assessment, we describe the OCT image analysis of a Pipeline Shield for treating an unruptured posterior communicating artery (PCOM) aneurysm. Results Use of intermediate catheters in the 3D-printed replicas was associated with better navigation of the OCT catheters in favorable anatomies but did not help as much in unfavorable anatomies. OCT image analysis of a PCOM aneurysm treated with Pipeline Embolization Device Shield demonstrated areas of unsatisfactory apposition with no thrombus formation. Conclusions OCT improves the understanding of the flow diversion technology. The development of less thrombogenic devices, like the Pipeline Flex with Shield Technology, reinforces the need for intraluminal imaging for neurovascular application.

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Mkhaiber, Ahmed, Auday Al-Bayati, and Itab Fadhil. "INVESTIGATION OF FAST NEURON ATTENUATION COEFFICIENTS FOR SOME IRAQI BUILDING MATERIALS." Malaysian Journal of Science 41, no. 2 (June 15, 2022): 81–89. http://dx.doi.org/10.22452/mjs.vol41no2.7.

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This research aims to improve the radiation shielding properties of polymer-based materials by mixing PVC with locally available building materials. Specifically, two key parameters of fast neutron attenuation (removal cross-section and half-value layer) were studied for composite materials comprising PVC reinforced with common building materials (cement, sand, gypsum and marble) in different proportions (10%, 30% and 50% by weight). To assess their effectiveness as protection against fast neutrons, the macroscopic neutron cross-section was calculated for each composite. Results show that neutron cross-section values are significantly affected by the reinforcement ratios, and that the composite material PVC + 50% gypsum is an effective shield against fast neutrons.

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Vereecke, Bart, Els Van Besien, Deniz Sabuncuoglu Tezcan, Nick Spooren, Nicolaas Tack, and Andy Lambrechts. "Fabrication of a CMOS-based Imaging Chip with Monolithically Integrated RGB and NIR Filters." Proceedings 2, no. 13 (January 8, 2019): 751. http://dx.doi.org/10.3390/proceedings2130751.

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Recent developments in multispectral cameras have demonstrated how compact and low-cost spectral sensors can be made by monolithically integrating filters on top of commercially available image sensors. In this paper, the fabrication of a RGB + NIR variation to such a single-chip imaging system is described, including the integration of a metallic shield to minimize crosstalk, and two interference filters: a NIR blocking filter, and a NIR bandpass filter. This is then combined with standard polymer based RGB colour filters. Fabrication of this chip is done in imec’s 200 mm cleanroom using standard CMOS technology, except for the addition of RGB colour filters and microlenses, which is outsourced.

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Chukwuneke, J. L., O. B. Fakiyesi, V. C. Obinani, and J. C. Okeke. "Production and Thermal-Structural Analysis of Welding Face Shield from Plantain Fibers Reinforced Polymer Matrix Composites." International Journal of Darshan Institute on Engineering Research & Emerging Technology 11, no. 1 (July 15, 2022): 24–33. http://dx.doi.org/10.32692/ijdi-eret/11.1.2022.2205.

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ITAKURA, Miho, Shuto MOCHIZUKI, Natsumi KOBARA, Garuda FUJII, and Masayuki NAKAMURA. "315 Optimal Design and its Application to Heat Shield Curtain using Multi-Layered Polymer Film Structure." Proceedings of Conference of Hokuriku-Shinetsu Branch 2016.53 (2016): _315–1_—_315–5_. http://dx.doi.org/10.1299/jsmehs.2016.53._315-1_.

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Journal articles on the topic 'Polymer shield'

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